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Ferreira, Thiago Penido Moreira, Mateus Martins Marcatti, Fabrício Melo Bertolini, Otaviano de Oliveira Junior, and Gustavo Araújo Nunes. "Arthroscopic Brostrom technique." Journal of the Foot & Ankle 14, no. 2 (August 30, 2020): 138–43. http://dx.doi.org/10.30795/jfootankle.2020.v14.1147.
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Objective: To present the clinical and functional results of surgical treatment of patients with chronic instability of the ankle using the arthroscopic Brostrom technique. Methods: This is a case series of patients who underwent surgical treatment for chronic instability of the lateral ligament of the ankle using the arthroscopic Brostrom technique. Clinical assessments of ankle stability were performed preoperatively and at the last follow-up using the American Orthopedic Foot and Ankle Score (AOFAS), a visual analog scale (VAS) for pain, and the anterior drawer and talar inversion tilt tests. Surgical complications and patient satisfaction ratings were also analyzed. Results: A total of 16 patients were analyzed, with a mean follow-up of 14 months. There was a statistically significant (p<0.001) improvement in mean AOFAS, which increased from 67.2 to 90.8 points and the mean VAS for pain score reduced from 6.5 to 1.5 points. All ankles were stable and had normal results for the anterior drawer test and the talar inversion tilt test. Three patients (19%) reported that resumption of sporting activities provoked subjective pain in the ankle, which improved progressively during follow-up. Two patients (12.5%) exhibited neurapraxia of the superficial peroneal nerve. A majority of the patients (81%) rated treatment as good or excellent. Conclusion: Treatment of chronic instability of the ankle ligament using the arthroscopic Brostrom technique restored ankle stability and achieved good clinical results. There was a high rate of early complications, but the majority were transitory and underwent complete remission during follow-up. Level of Evidence IV; Therapeutic Studies; Case Series.
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Eun, Sang Soo, Sang-Ho Lee, and H. Erken. "Transforaminal Percutaneous Endoscopic Lumbar Diskectomy for Downmigrated Disk Herniations: Lever-Up, Rotate, and Tilt Technique." Journal of Neurological Surgery Part A: Central European Neurosurgery 79, no. 02 (December 14, 2017): 163–68. http://dx.doi.org/10.1055/s-0037-1608837.
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Background and Study Aims Although transforaminal percutaneous endoscopic lumbar diskectomy (PELD) offers certain advantages in the treatment of disk herniations, it used to be limited to nonmigrated or low-migrated herniations. With improvements in endoscopic spinal surgery, the range of indications for PELD has expanded. Various techniques including transforaminal and interlaminar approaches for migrated disk herniations are described in the literature. This study describes a transforaminal PELD approach to address downmigrated intracanal soft disk herniations effectively using the lever-up, rotate, and tilt technique. Patients and Methods We performed a retrospective review of 18 patients who had been operated on with the described technique between October 2012 and December 2015. We assessed clinical outcomes using the visual analog scale (VAS) for back and leg pain and the Oswestry Disability Index (ODI) preoperatively at their respective clinical visits and postoperatively at the patients' final follow-up examinations. Results The mean preoperative VAS scores for back and leg pain were 3.75 + 1.34 (range: 2–6) and 8.3 + 0.6 (range: 8–10), respectively. The mean preoperative ODI was 67.3 + 15.3 (range: 48–90). The mean VAS scores for back and leg pain improved to 1.38 + 1.58 (range: 0–6) and 1.19 + 0.75 (range: 0–3), respectively, at the last follow-up. The mean ODI also improved to 14.1 + 6.2 (range: 8–30) at the last follow-up. All differences between the preoperative and last follow-up scores were statistically significant (p < 0.05), Two surgeries failed because of a remnant disk fragment. Conclusions The lever-up, rotate, and tilt technique for transforaminal PELD is an effective maneuver to treat downmigrated disk herniations in selected patients by experienced surgeons.
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Mukai, S., and J. Hayano. "Heart rate and blood pressure variabilities during graded head-up tilt." Journal of Applied Physiology 78, no. 1 (January 1, 1995): 212–16. http://dx.doi.org/10.1152/jappl.1995.78.1.212.
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We investigated the responses of the frequency components of heart rate (HR) and blood pressure (BP) variabilities to progressive changes in autonomic activity induced by the graded head-up tilt technique in 12 normal subjects (age 19–27 yr) under the condition of frequency-controlled respiration (0.25 Hz). During low-level tilt (0–30 degrees), the R-R interval was unchanged and the amplitude of the high-frequency (HF; 0.25 Hz) component of HR variability showed only a slight insignificant decrease. The amplitude of the low-frequency (LF; 0.04–0.15 Hz) component of HR variability increased progressively as the angle increased (P < 0.05). During high-level tilt (30–90 degrees), the R-R interval and the HF amplitude of HR variability decreased progressively with tilt angle (P < 0.001 for both). The LF amplitude of HR variability peaked at a tilt angle of 30 degrees. The LF-to-HF ratio of HR variability and the LF amplitude of systolic and diastolic BP variabilities increased progressively as the tilt angle increased from 0 to 60 degrees (P < 0.001), although systolic and diastolic BPs were unchanged. These results suggest that mixed autonomic responses to orthostatic stress, which are thought to be mediated by both cardiopulmonary and arterial baroreflex mechanisms, can be distinguished by changes in the frequency components of HR and BP variabilities.
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Afrin Rimi, Sadia, Iffat Rezwana, Shamima Sultana, and Sultana Ferdousi. "Gender differences in circulatory adjustment to head-up tilt test in health." Medical Science Pulse 14, no. 1 (June 23, 2020): 1–17. http://dx.doi.org/10.5604/01.3001.0014.2323.
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Background: A tilt table test is a useful, non-invasive technique that has been used for the last few decades to detect autonomic failure. The response to tilting may vary physiologically between sexes. Aim of the study: To assess the gender-specific changes in cardiovascular response to a tilt test in healthy subjects. Materials and Methods: This experimental study was conducted on 90 healthy males and females aged 18 - 60 years, from 2019 to 2020. Forty- five male subjects and 45 female subjects were included. Using a motorized tilt table, a tilt table test was performed at 60 degrees for 10 minutes. An automatic sphygmomanometer was used to measure blood pressure (BP), and heart rate (HR) and a pulse oximeter was used for the measurement of peripheral capillary oxygen saturation (SpO2). An independent sample t test, a multiple regression analysis and a chi squared test were conducted for statistical analyses. Results: A significantly greater drop in systolic blood pressure (SBP) was observed in females, compared to males after tilting. In 5.5% of the subjects, orthostatic intolerance occurred, but there were no significant age or gender- specific differences in subjects with orthostatic intolerance. Conclusion: This study concluded that in response to tilting, cardiovascular response was less pronounced in females.
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Laroia, Sandeep T., Justin J. Guan, Archana T. Laroia, Lucas Lenhart, and Antony J. Hayes. "A New Catheter Technique to Correct Severe IVC Filter Tilt during Placement." Journal of Clinical Interventional Radiology ISVIR 4, no. 01 (December 16, 2019): 27–30. http://dx.doi.org/10.1055/s-0039-3401346.
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Abstract Introduction Inferior vena cava (IVC) filter tilt is a common complication that occurs during and after filter placement. Severe tilting leads to reduced filter efficacy, lower retrieval success, and higher complication rates during retrieval. We present a novel catheter technique to correct severely tilted cone-shaped IVC filters without having to retrieve and replace the existing filter. Methods A retrospective review was performed for patients at our institution over three years who had severely tilted filters and underwent correction with the catheter technique. Indications for filter placement were categorized, and patient age, gender, tilt correction outcome, and complication rates were collected and analyzed. After severe tilting was noted on post-IVC filter deployment venogram, a Sos catheter was passed via the same femoral access site used for the filter placement. The catheter tip was reformed inside the cone of the filter and was used to push the filter tip back toward midline. Completion venogram was taken to document the amelioration of the tilt. Results Out of 28 patients who were found to have severely tilted filters on deployment and underwent correction with the catheter technique, 27/28 (96.4%) had successful correction. One (3.6%) had a minor complication where the filter struts became entangled with the catheter tip; however, simple maneuvering of the catheter and use of a stiff wire to straighten the catheter loop freed up the entanglement. No major complications occurred. Conclusion This technique is safe, effective, obviates filter replacement, and can be considered an additional management option for severe IVC filter tilt during placement.
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Musacchia, X. J., J. M. Steffen, and J. Dombrowski. "Rat cardiovascular responses to whole body suspension: head-down and non-head-down tilt." Journal of Applied Physiology 73, no. 4 (October 1, 1992): 1504–9. http://dx.doi.org/10.1152/jappl.1992.73.4.1504.
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The rat whole body suspension technique mimics responses seen during exposure to microgravity and was evaluated as a model for cardiovascular responses with two series of experiments. In one series, changes were monitored in chronically catheterized rats during 7 days of head-down tilt (HDT) or non-head-down tilt (N-HDT) and after several hours of recovery. Elevations of mean arterial (MAP), systolic, and diastolic pressures of approximately 20% (P < 0.05) in HDT rats began as early as day 1 and were maintained for the duration of suspension. Pulse pressures were relatively unaffected, but heart rates were elevated approximately 10%. During postsuspension (2–7 h), most cardiovascular parameters returned to presuspension levels. N-HDT rats exhibited elevations chiefly on days 3 and 7. In the second series, blood pressure was monitored in 1- and 3-day HDT and N-HDT rats to evaluate responses to rapid head-up tilt. MAP, systolic and diastolic pressures, and HR were elevated (P < 0.05) in HDT and N-HDT rats during head-up tilt after 1 day of suspension, while pulse pressures remained unchanged. HDT rats exhibited elevated pretilt MAP and failed to respond to rapid head-up tilt with further increase of MAP on day 3, indicating some degree of deconditioning. The whole body suspended rat may be useful as a model to better understand responses of rats exposed to microgravity.
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Piao, Lin Hua, Yan Jie Li, Bai Hua Li, Ming Ming Ji, and Xue Yan Zhang. "The Research of Micromachined Airflow Tilt Sensor." Advanced Materials Research 108-111 (May 2010): 682–85. http://dx.doi.org/10.4028/www.scientific.net/amr.108-111.682.
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Micromachine airflow tilt sensor which can be sensitive to tilt angle is described. Adopt micro-machined technique two deep groove are corroded on the silicon plate, and two cantilever beams of metal film heated hot wire is set up at each deep groove. Semicircle airtight space forms sense elements. Through Wheatstone bridge, we get the tilt output voltage. Single-chip computer and temperature sensor constitute compensation circuit to achieve temperature compensation and linear compensation. The test showed the sensor’s performance is as follow: measuring range is ±30,resolution<0.1°, working temperature is better than 50ms ,nonlinear<0.1%.The sensor is not only in small size but also in simply crafting. It is good in sensitive organ’s output consistency, and suitable for mass production.
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Menezes, Cristiano Magalhães, Leonardo Fernandes Aguiar, André de Oliveira Arruda, Rodrigo Vieira Cardoso, Germano Senna Oliveira do Valle, Rodrigo Souza Lima, Mário Leite Bringel, Felipe Miranda Mendonça Fernandes, and Joint Halley Guimbard Pérez. "IMPACT OF THE MIS-TLIF TECHNIQUE ON THE SPINOPELVIC PARAMETERS OF PATIENTS WITH LUMBAR ARTHRODESIS." Coluna/Columna 18, no. 1 (March 2019): 47–50. http://dx.doi.org/10.1590/s1808-185120191801188450.
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ABSTRACT Objective: To evaluate the influence of the MIS-TLIF technique on the spinopelvic parameters of patients submitted to lumbar arthrodesis up to three levels for the treatment of vertebral degenerative conditions without deformity. Methods: Retrospective radiographic evaluation of 52 patients submitted to the surgical treatment of lumbar arthrodesis using the MIS-TLIF technique in up to three levels. The spinopelvic parameters – pelvic incidence (PI), pelvic tilt(PT), lumbar lordosis (LL), segmental lordosis (Lseg), and the difference between lumbar lordosis and pelvic incidence (LL-PI mismatch) were analyzed in orthostatic lateral radiographs in the pre- and postoperative periods, with a minimum follow-up of 1 year. The patients were divided into three groups: PI <45°, PI between 45° and 55° and PI >55°. Results: Sixty-nine operated levels were evaluated in 15 patients with PI <45°, 19 with PI between 45° and 55° and 18 with PI >55°. The mean value of the pelvic incidence was 52.3° (± 11.5), lumbar lordosis 46.1° (pre)/45.6° (post); segmental lordosis 20.3° (pre)/20.6° (post); pelvic tilt 18.5° (pre)/18.2° (post); “mismatch” (PI-LL) 7° (pre)/ 6.6° (post), with no statistical difference among all parameters (p>0.05). Conclusions: The MIS-TLIF technique had no influence on postoperative spinopelvic parameters of patients undergoing lumbar arthrodesis surgery. Level of evidence: III. Retrospective comparative study.
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Soto, Gabriel E., Stephen J. Young, Maryann E. Martone, Thomas J. Deerinck, Stephan Lamont, Bridget O. Carragher, and Mark H. Ellisman. "Tomographic methods for detailed examination of large structures in the nervous system." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 96–97. http://dx.doi.org/10.1017/s0424820100146321.
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One of the limitations of electron microscopy has been the requirement for very thin samples to allow penetration of the electron beam. It is often the case that structures of interest are not contained within a single thin section. In these cases, serial sectioning techniques are required to reconstruct the object in its entirety. The use of higher voltage electron microscopes has allowed researchers to examine specimens up to fifty times thicker than those suitable for a conventional TEM. However, images from thick sections are often difficult to interpret as the electron micrograph is essentially a projection of the overlapping material within the section. The method of computerized axial tilt electron microscopic tomography offers the potential to visualize and analyze information contained in a thick section by deriving a three dimensional volume from a series of projections acquired by collecting images of the specimen at successive tilt increments about the Y axis. Unfortunately there are practical limitations to the resolution that can be obtained using this technique with very thick sections. Resolution of the tomogram increases with finer tilt sampling and an increased range of tilts but decreases with section thickness.
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Hayano, J., J. A. Taylor, A. Yamada, S. Mukai, R. Hori, T. Asakawa, K. Yokoyama, Y. Watanabe, K. Takata, and T. Fujinami. "Continuous assessment of hemodynamic control by complex demodulation of cardiovascular variability." American Journal of Physiology-Heart and Circulatory Physiology 264, no. 4 (April 1, 1993): H1229—H1238. http://dx.doi.org/10.1152/ajpheart.1993.264.4.h1229.
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Usefulness of complex demodulation (CDM) in assessing the frequency components of cardiovascular variability was assessed and, subsequently, this technique was utilized to determine the time-dependent responses of the low-frequency (LF) and high-frequency (HF) amplitudes of heart rate and blood pressure variabilities during postural tilt. CDM provides the time-dependent changes in amplitude of a particular frequency component on a continuous basis. Analysis of simulated data showed that CDM has sufficient frequency resolution to separately measure LF and HF amplitudes with a time resolution < 15 s and that CDM is robust to alterations in the frequency of the components. Analysis of actual data during postural tilt test in 23 young healthy subjects demonstrated that the HF amplitude of heart rate, an index of cardiac parasympathetic tone, rapidly decayed with head-up tilt (P < 0.01) and increased quickly showing an overshoot with tilt back to the supine position (P < 0.01). The LF amplitude of blood pressure, an index of vasomotor sympathetic activity, showed marked rhythmic fluctuation at an interval of 48-100 s during head-up tilt (P < 0.01), synchronizing with similar fluctuation in the LF amplitude of heart rate (P < 0.01). These results suggest that CDM can be used to provide a continuous assessment of cardiovascular variability components and that the dynamic responses of autonomic circulatory control to upright posture result in a phasic modulation of LF amplitude.
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Kalisiak, Michał, and Wojciech Wiatr. "Errors in Broadband Permittivity Determination Due to Liquid Surface Distortions in Semi-Open Test Cell." Remote Sensing 13, no. 5 (March 5, 2021): 983. http://dx.doi.org/10.3390/rs13050983.
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We study how surface distortions of liquid samples due to a meniscus and a tilt of a semi-open coaxial test cell affect errors in a broadband permittivity determination. The study is based on the scattering parameters, obtained using the electromagnetic simulations of samples with flat and distorted surfaces in a broad frequency range up to 18 GHz. The parameters are processed with the classic Nicolson–Ross–Weir (NRW) method and our new meniscus removal technique. We analyze the errors for several samples of different properties, such as distilled water and propan-2-ol. The results show that the meniscus removal technique is more robust and provides smaller errors in the permittivity determination compared to the classic NRW method. The effect of the cell tilt, to our best knowledge, has not been considered in the literature yet.
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Halder, Tarak Chandra, Divyanshu Kumar, and Biplab Chatterjee. "Paediatric Radial Neck Fracture Fixation by Metaizeau Technique - Surgical Technique and Outcome." Journal of Evidence Based Medicine and Healthcare 8, no. 17 (April 26, 2021): 1100–1104. http://dx.doi.org/10.18410/jebmh/2021/213.
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BACKGROUND Radial neck fractures in children are serious injuries with frequent sequelae when the tilt exceeds 60 degrees. Conservative treatment is often inadequate in such cases and open reduction may produce iatrogenic complications. Displaced radial neck fractures in the paediatric population can be treated with retrograde intramedullary nailing of the radius (the Metaizeau technique). This method allows early post-operative movement and thus has high functional outcome. The purpose of this case series was to evaluate the functional outcome of Metaizeau technique. METHODS This is a prospective study in which follow-up of 9 cases with radial neck fracture treated with Metaizeau technique was done. Clinical and radiological evaluation was done at 2 weeks, 4 weeks, 6 weeks and 6 months. Active range of motion of flexion and extension at elbow and forearm rotation was noted at 6 weeks along with pain score and Mayo Elbow Performance Score (MEPS). Radiological assessment was also done at 6 weeks regarding union. RESULTS 8 out of 9 cases had radiological union at 6 weeks. 1 case was lost to follow-up. Excellent result was obtained in all 8 cases. Range of flexion-extension, supinationpronation were identical in all 8 cases. 1 case developed pressure bursitis at entry site. CONCLUSIONS Metaizeau technique for radial neck fracture fixation is simple, safe, soft tissue sparing, minimally invasive technique giving excellent functional and cosmetic results with minimal complication. KEYWORDS Metaizeau Technique, Retrograde Intramedullary Nailing, Radial Neck Fracture, MEPS
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Wu, Kaicheng, Wangyi Fang, Yuan Zong, Jian Yu, Canqing Xu, Chunhui Jiang, and Ye Tan. "Modified Four-Point Scleral Suture Fixation Technique for Repositioning a Dislocated Intraocular Lens in the Absence of Capsule Support." Journal of Ophthalmology 2020 (November 18, 2020): 1–9. http://dx.doi.org/10.1155/2020/8824896.
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Purpose. To study the efficacy of a modified four-point fixation technique for the repositioning of a dislocated intraocular lens (IOL) with four eyelets in the absence of capsule support. Methods. Four patients with dislocated four-eyelet hydrophilic acrylic IOLs (Akreos AO60) were enrolled. The modified technique combined four-point fixation with intrascleral sutures and suture burying. The technique minimized the limbus incision to 1 mm with no externalization of the IOL or its haptics. Follow-ups included routine ophthalmic examinations, corneal endothelial cell counts, and measurement of IOL tilt and decentration (measured using Pentacam® HR images). Results. The IOLs were successfully repositioned in all cases. After a mean follow-up period of 19.75 ± 7.85 months (range: 8 to 24 months), the patients’ best-corrected vision acuity (BCVA (LogMAR), before: 0.63 ± 0.36, after: 0.58 ± 0.43, P = 0.604 ) and intraocular pressure (pre 13.35 ± 0.85 mmHg, post 14.80 ± 2.03 mmHg, P = 0.150 ) remained unchanged. Corneal endothelium density decreased about 6.84 ± 2.97%. In all cases, the IOL was well positioned during the follow-up. At the final visit, the average IOL tilt was 1.36 ± 0.35° horizontally and 1.31 ± 0.14° vertically. The average IOL decentration was 0.23 ± 0.12 mm horizontally and 0.18 ± 0.13 mm vertically. Conclusions. With this modified technique, dislocated IOLs with four-eyelets could be treated safely with favorable outcomes.
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Suomalainen, Juha, Teemu Hakala, Raquel Alves de Oliveira, Lauri Markelin, Niko Viljanen, Roope Näsi, and Eija Honkavaara. "A Novel Tilt Correction Technique for Irradiance Sensors and Spectrometers On-Board Unmanned Aerial Vehicles." Remote Sensing 10, no. 12 (December 19, 2018): 2068. http://dx.doi.org/10.3390/rs10122068.
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In unstable atmospheric conditions, using on-board irradiance sensors is one of the only robust methods to convert unmanned aerial vehicle (UAV)-based optical remote sensing data to reflectance factors. Normally, such sensors experience significant errors due to tilting of the UAV, if not installed on a stabilizing gimbal. Unfortunately, such gimbals of sufficient accuracy are heavy, cumbersome, and cannot be installed on all UAV platforms. In this paper, we present the FGI Aerial Image Reference System (FGI AIRS) developed at the Finnish Geospatial Research Institute (FGI) and a novel method for optical and mathematical tilt correction of the irradiance measurements. The FGI AIRS is a sensor unit for UAVs that provides the irradiance spectrum, Real Time Kinematic (RTK)/Post Processed Kinematic (PPK) GNSS position, and orientation for the attached cameras. The FGI AIRS processes the reference data in real time for each acquired image and can send it to an on-board or on-cloud processing unit. The novel correction method is based on three RGB photodiodes that are tilted 10° in opposite directions. These photodiodes sample the irradiance readings at different sensor tilts, from which reading of a virtual horizontal irradiance sensor is calculated. The FGI AIRS was tested, and the method was shown to allow on-board measurement of irradiance at an accuracy better than ±0.8% at UAV tilts up to 10° and ±1.2% at tilts up to 15°. In addition, the accuracy of FGI AIRS to produce reflectance-factor-calibrated aerial images was compared against the traditional methods. In the unstable weather conditions of the experiment, both the FGI AIRS and the on-ground spectrometer were able to produce radiometrically accurate and visually pleasing orthomosaics, while the reflectance reference panels and the on-board irradiance sensor without stabilization or tilt correction both failed to do so. The authors recommend the implementation of the proposed tilt correction method in all future UAV irradiance sensors if they are not to be installed on a gimbal.
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Piao, Lin Hua, Yan Jie Li, Bai Hua Li, Ming Ming Ji, and Xue Yan Zhang. "The Research of Two-Dimension Micromachined Level Posture Sensor." Advanced Materials Research 108-111 (May 2010): 676–81. http://dx.doi.org/10.4028/www.scientific.net/amr.108-111.676.
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Two-dimension level posture sensor which can be sensitive to two vertical-directional tilt angle at one time is described. Adopt micro-machined technique two deep groove are corroded on the silicon plate, and two cantilever beams of metal heated hot wire is set up at each deep groove. Semicircle airtight space forms sense elements. Through two Wheatstone bridge, we get the tilt output voltage of x axis and y axis. To overcome environmental factors, a series of signal processing methods are proposed ,such as: zero temperature compensation, sensitive temperature compensation and linear compensation. The test about the sensor showed the sensor’s performance is as follow: resolution<0.05°,nonlinear<0.1%,the working temperature is enlarged.
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Grubb, Blair P., Allan M. Rubin, Douglas Wolfe, Peter Temesy-Armos, Harry Hahn, and Laura Elliott. "Head-Upright Tilt-Table Testing: A Useful Tool in the Evaluation and Management of Recurrent Vertigo of Unknown Origin Associated with Near-Syncope or Syncope." Otolaryngology–Head and Neck Surgery 107, no. 4 (October 1992): 570–76. http://dx.doi.org/10.1177/019459989210700410.
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Recurrent idiopathic vertigo associated with near-syncope and syncope is a common perplexing problem, some cases of which are considered autonomically mediated (vasovagal). Upright-tilt-table testing has emerged as a potential method to test for vasovagal episodes. This study evaluated the use of this technique in the evaluation and management of patients with recurrent idiopathic vertigo associated with near-syncope or syncope. Twenty-one patients with recurrent unexplained vertigo and syncope/near-syncope and 11 control subjects were evaluated by use of an upright-tilt-table test for 30 minutes, with or without a graded isoproterenol infusion (1 to 4 μg/min given intravenously), in an attempt to provoke hypotension, bradycardia, or both, which reproduced the patient's symptoms. The patients included 10 men and 11 women (mean age, 51 ± 16 years). Eleven controls with no history of vertigo were also studied. Transcranial Doppler sonography was used to assess cerebral arteriolar blood flow during tilt. All tilt-positive patients were placed on therapy with either β-blockers, disopyramide, or transdermal scopolamine, the effectiveness of which was determined with another tilt-table study. Symptoms occurred in seven patients (33%) during the baseline tilt and in eight patients (38%) during isoproterenol infusion (total positives, 71%). Transcranial Doppler sonography demonstrated a 225% ± 192% increase in pulsatility index and a 70% ± 29% increase in resistance index (indicative of cerebral arteriolar vasoconstriction) at the time of vertigo. No control subject experienced syncope during this test. Each tilt-positive patient eventually became tilt-negative with therapy, and over a mean follow-up period of 26 months, no further episodes have occurred. We conclude that head-upright tilt-table testing may be a valuable tool in the evaluation of recurrent idiopathic vertigo associated with near-syncope or syncope and in the evaluation of pharmacotherapy.
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Sherman, M. B., J. Jakana, S. Sunt, p. Matsudaira, W. Chiu, and M. F. Schmid. "New Strategy for Crystallographic Reconstruction of Biological Bundle-Like Structures." Microscopy and Microanalysis 3, S2 (August 1997): 1035–36. http://dx.doi.org/10.1017/s143192760001206x.
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The acrosomal bundle is an intracellular quasi-crystalline organelle in the head of the sperm of Limulus polyphemus . It is a long (up to 60 μm) straight bundle ∼1000 Å in diameter1 consisting of two major proteins in a 1:1 stoichiometric ratio: actin (42 kDa) and scruin (102 kDa) with a minor calmodulin-like protein (14 kDa) presumably bound to scruin molecule. Previous helical reconstructions of single filaments in the bundle showed actin-scruin interactions. We recorded tilt series from single bundles in a 400 kV cryomicroscope and have developed a novel crystallographic technique to reconstruct a unit cell from the bundle as a whole to reveal interfilament interactions.Acrosomal bundles were purified as described elsewhere and embedded in vitreous ice over holes on a holey carbon film. Tilt series images were collected in a JEOL 4000EX electron cryo-microscope at 400 kV using 10,000x microscope magnification. Total dose was ∼16-18 electrons/Å per series covering a tilt range of ± 60° with 5° angular increment.
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Yercan, Hüseyin Serhat, Gürler Kale, Serkan Erkan, Taçkın Özalp, and Güvenir Okcu. "Medial Patellofemoral Ligament Reconstruction in Skeletally Immature Patients." Orthopaedic Journal of Sports Medicine 2, no. 11_suppl3 (November 1, 2014): 2325967114S0015. http://dx.doi.org/10.1177/2325967114s00158.
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Objectives: To evaluate the clinical outcome after medial patellofemoral ligament (MPFL) reconstruction for patellofemoral instability in skeletally immature patients. Methods: Study participants were 8 patients ( median age, 10 years; range, 5-14 and one male , others female) who had suffered from persistent patellofemoral instability. Our technique preserves femoral and patellar insertion anatomy of MPFL using a free semitendinosus autograft, together with tenodesis to the adductor magnus tendon thus sparing the open physis of distal femur and the patellar attachment of MPFL. The clinical results were evaluated preoperatively and the final follow-up period using the Kujala patellofemoral score. Patellar shift, tilt and height were measured preoperatively and on the latest follow-up on plain radiographs. Results: At average 42 months follow-up ( range, 16 to 56), %80 of patients were satisfied with the treatment. Redislocation or instability symptoms occurred in two patients. No apprehension signs or redislocations were seen in the remanining six patients. A significant improvement (p‹0.05) in Kujala score (from 36 to 77) was found. Patellar shift & tilt decreased to anatomic values in six patients but patella alta persisted. Conclusion: The result of this study show that MPFL reconstruction with our technique seems to be an effective treatment for recurrent and habitual patellofemoral dislocation in skeletally immature patients; leading to significant increases in stability and functionality.
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Ibrahim, Hesham A., and Heba Nabil Sabry. "The Balanced Two-String Technique for Sulcus Intraocular Lens Implantation in the Absence of Capsular Support." Journal of Ophthalmology 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/153963.
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Purpose. To describe and explore an alternative approach for sulcus intraocular lens (IOL) implantation in the absence of capsular support.Methods. The commonly available one-piece poly(methyl methacrylate) (PMMA) lens is stabilized in the sulcus by two intraocular horizontal strings of 10/0 polypropylene suture passed through the lens dialing holes in opposite directions to achieve a mechanical balance. The horizontal strings of 10/0 polypropylene work as a rail track for the IOL optics, allowing some side to side lens adjustment even following wound closure. The stability of the IOL was tested in vitro. Six aphakic patients underwent in-sulcus IOL secondary implantation using the balanced two-string technique. Patients were followed up for a minimum of six months. Best spectacle corrected vision was assessed. Lens centration and lens tilt were measured by anterior segment optical coherence tomography (AS-OCT).Results. All patients had successful lens insertion. Best spectacle corrected visual acuity (BSCVA) improved in all patients. Lens decentration ranged between 0.21 mm and 0.9 mm (average 0.53 mm). Lens tilt ranged between 1.2° and 2.8° (average 2.17°).Conclusion. The mechanically balanced two-string technique is an alternative option for sulcus IOL implantation in absence of capsular support, allowing lens centration adjustment with no additional risks.
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Dalla Vecchia, Laura, Franca Barbic, Andrea Galli, Massimo Pisacreta, Rosella Gornati, Tiziano Porretta, Alberto Porta, and Raffaello Furlan. "Favorable effects of carotid endarterectomy on baroreflex sensitivity and cardiovascular neural modulation: a 4-month follow-up." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 304, no. 12 (June 15, 2013): R1114—R1120. http://dx.doi.org/10.1152/ajpregu.00078.2013.
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Carotid surgery variably modifies carotid afferent innervation, thus affecting arterial baroreceptor sensitivity. Low arterial baroreflex sensitivity is a well-known independent risk factor for cardiovascular diseases. The aim of this study was to assess the 4-mo effects of carotid endarterectomy (CEA) on arterial baroreceptor sensitivity and cardiovascular autonomic profile in patients with unilateral carotid stenosis. We enrolled 20 patients (72 ± 8 yr) with unilateral >70% carotid stenosis. ECG, beat-by-beat blood pressure, and respiration were continuously recorded before and 126 ± 9 days after CEA, at rest and during a 75° head-up tilt. Both pharmacological (modified Oxford technique, BRS) and spontaneous (index α, spectral analysis) arterial baroreflex sensitivity were assessed. Cardiovascular autonomic profile was evaluated by plasma catecholamines and spectral indexes of cardiac sympathovagal modulation [low-frequency R-R interval (LFRR), low frequency-to high frequency ratio (LF/HF), high-frequency R-R interval (HFRR)] and sympathetic vasomotor control [low-frequency systolic arterial pressure (LFSAP)] obtained from heart rate and SAP variability. After CEA, both the index α and BRS were higher ( P < 0.02) at rest. SAP variance decreased both at rest and during tilt ( P < 0.02). Before surgery, tilt did not modify the autonomic profile compared with baseline. After CEA, tilt increased LF/HF and LFSAP and reduced HFRR compared with rest ( P < 0.02). Four months after CEA was performed, arterial baroreflex sensitivity was enhanced. Accordingly, the patients' autonomic profile had shifted toward reduced cardiac and vascular sympathetic activation and enhanced cardiac vagal activity. The capability to increase cardiovascular sympathetic activation in response to orthostasis was restored. Baroreceptor sensitivity improvement might play an additional role in the more favorable outcome observed in patients after carotid surgery.
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Kamiya, Atsunori, Toru Kawada, Shuji Shimizu, Satoshi Iwase, Masaru Sugimachi, and Tadaaki Mano. "Slow head-up tilt causes lower activation of muscle sympathetic nerve activity: loading speed dependence of orthostatic sympathetic activation in humans." American Journal of Physiology-Heart and Circulatory Physiology 297, no. 1 (July 2009): H53—H58. http://dx.doi.org/10.1152/ajpheart.00260.2009.
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Many earlier human studies have reported that increasing the tilt angle of head-up tilt (HUT) results in greater muscle sympathetic nerve activity (MSNA) response, indicating the amplitude dependence of sympathetic activation in response to orthostatic stress. However, little is known about whether and how the inclining speed of HUT influences the MSNA response to HUT, independent of the magnitude of HUT. Twelve healthy subjects participated in passive 30° HUT tests at inclining speeds of 1° (control), 0.1° (slow), and 0.0167° (very slow) per second. We recorded MSNA (tibial nerve) by microneurography and assessed nonstationary time-dependent changes of R-R interval variability using a complex demodulation technique. MSNA averaged over every 10° tilt angle increased during inclination from 0° to 30°, with smaller increases in the slow and very slow tests than in the control test. Although a 3-min MSNA overshoot after reaching 30° HUT was observed in the control test, no overshoot was detected in the slow and very slow tests. In contrast with MSNA, increases in heart rate during the inclination and after reaching 30° were similar in these tests, probably because when compared with the control test, greater increases in plasma epinephrine counteracted smaller autonomic responses in the very slow test. These results indicate that slower HUT results in lower activation of MSNA, suggesting that HUT-induced sympathetic activation depends partially on the speed of inclination during HUT in humans.
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Dolabella, Simone, Ruggero Frison, Gilbert A. Chahine, Carsten Richter, Tobias U. Schulli, Zuhal Tasdemir, B. Erdem Alaca, Yusuf Leblebici, Alex Dommann, and Antonia Neels. "Real- and Q-space travelling: multi-dimensional distribution maps of crystal-lattice strain (∊044) and tilt of suspended monolithic silicon nanowire structures." Journal of Applied Crystallography 53, no. 1 (February 1, 2020): 58–68. http://dx.doi.org/10.1107/s1600576719015504.
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Silicon nanowire-based sensors find many applications in micro- and nano-electromechanical systems, thanks to their unique characteristics of flexibility and strength that emerge at the nanoscale. This work is the first study of this class of micro- and nano-fabricated silicon-based structures adopting the scanning X-ray diffraction microscopy technique for mapping the in-plane crystalline strain (∊044) and tilt of a device which includes pillars with suspended nanowires on a substrate. It is shown how the micro- and nanostructures of this new type of nanowire system are influenced by critical steps of the fabrication process, such as electron-beam lithography and deep reactive ion etching. X-ray analysis performed on the 044 reflection shows a very low level of lattice strain (<0.00025 Δd/d) but a significant degree of lattice tilt (up to 0.214°). This work imparts new insights into the crystal structure of micro- and nanomaterial-based sensors, and their relationship with critical steps of the fabrication process.
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BELLARD, Elisabeth, Jacques-Olivier FORTRAT, Daniel SCHANG, Jean-Marc DUPUIS, Jacques VICTOR, and Georges LEFTHÉRIOTIS. "Changes in the transthoracic impedance signal predict the outcome of a 70° head-up tilt test." Clinical Science 104, no. 2 (January 14, 2003): 119–26. http://dx.doi.org/10.1042/cs1040119.
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We determined whether early changes in central haemodynamics, as determined by transthoracic impedance, induced by a 70° head-up tilt (HUT) test could predict syncope. Heart rate, arterial blood pressure and central haemodynamics [pre-ejection period and rapid left ventricular ejection time (T1), slow ejection time (T2) and dZ/dtmax (where Z is thoracic impedance), assessed by the transthoracic impedance technique], were recorded during supine rest and during a 45min 70° HUT test in 68 patients (40±2 years) with a history of unexplained recurrent syncope. We found that 38 patients (42±3 years) had a symptomatic outcome to 70° HUT (fainters) and 30 (39±2 years) had a negative outcome (non-fainters). When measured between 5 and 10min of 70° HUT, T2 had increased significantly only in the fainters, and a change in T2 of >40ms from baseline predicted a positive outcome with a sensitivity of 68% and a specificity of 70%. During supine rest prior to 70° HUT, the fainters exhibited a shorter T2 than non-fainters (183±10 compared with 233±14ms; P<0.01), and a T2 of <199ms predicted a positive outcome to 70° HUT with a sensitivity of 68% and a specificity of 63%. Incorporation of the changes that occurred from rest to 70° HUT in other haemodynamic variables (heart rate >11 beats/min, systolic pressure <2 mmHg, diastolic pressure <7 mmHg and pulse pressure <-3 mmHg) increased the specificity to 97% and the positive predictive value to 93%. Thus transthoracic impedance could detect differences in central haemodynamics between fainters and non-fainters during supine rest and during the initial period of 70° HUT with a consistent sensitivity and specificity when combined with peripheral haemodynamic variables.
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Burdekin, M., and H. J. Pahk. "The Application of a Microcomputer to the on-line Calibration of the Flatness of Engineering Surfaces." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 203, no. 2 (May 1989): 127–37. http://dx.doi.org/10.1243/pime_proc_1989_203_058_02.
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In this paper, a microcomputer aided system for the calibration of the flatness of engineering surfaces is proposed. Rectangular grid-type measurement procedures with closing error technique are offered for angular assessment on the surfaces using electronic precision level. A new technique called ‘enclose tilt technique’ (ETT) is developed for the analysis of flatness in terms of minimum zone, and defines the flatness in terms of British and ISO standards. These measurement analysis processes are performed on-line with a microcomputer using an analogue/digital interface, amplifier with low-pass filter, triggering technique, etc., and appropriate high-level and low-level programming language. A practical flatness calibration of a granite table has been performed for application, and the results are shown with up to 0.1 μm uncertainty. The effect of the weight of the precision level, and the rigidity test of the granite table have also been assessed.
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Hu, Zhi-Xiang, HaiShuang Lin, Lingying Ye, Zhong Lin, Tianyu Chen, Ke Lin, and Rong-Han Wu. "Sutureless Intrascleral Haptic-Hook Lens Implantation Using 25-Gauge Trocars." Journal of Ophthalmology 2018 (December 26, 2018): 1–5. http://dx.doi.org/10.1155/2018/9250425.
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Purpose. To report a new technique for sutureless intrascleral fixation of three-piece foldable intraocular lenses (IOLs) using 25-gauge trocars. Methods. We performed this technique on patients with insufficient posterior capsule support. Seventeen eyes from 15 patients with aphakia, dislocated IOL, or subluxated crystalline lens undergoing posterior chamber sutureless implantation of an IOL were studied. The haptics of the IOL were externalized using two 25-gauge forceps. The haptics were bended back (hook-like) into the vitreous cavity through a scleral incision made by using a 25-gauge trocar. And, IOL tilt was determined by using a slit lamp and UBM, and complications were recorded. Results. The IOLs were fixed with exact centration and axial stability. No wound leakage was reported even without the use of sutures. The mean best-corrected visual acuity (BCVA) was 0.82 logarithm of the minimum angle of resolution (logMAR) units preoperatively, and the mean BCVA was 0.44 logMAR units at the 6-month follow-up visit. No postoperative retinal detachment, endophthalmitis, IOL tilt or dislocation, or vitreous hemorrhage was noted. Conclusion. Sutureless intrascleral haptic-hook posterior chamber IOL implantation using 25-gauge trocars provides good IOL fixation with reliable wound closure without the use of sutures. This trial is registered with ChiCTR1800017436.
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Lacolley, P. J., B. M. Pannier, M. A. Slama, J. L. Cuche, A. P. G. Hoeks, S. Laurent, G. M. London, and M. E. Safar. "Carotid arterial haemodynamics after mild degrees of lower-body negative pressure in man." Clinical Science 83, no. 5 (November 1, 1992): 535–40. http://dx.doi.org/10.1042/cs0830535.
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1. Pulsatile changes in the diameter of the common carotid artery were studied transcutaneously using an echo-tracking technique in 15 normal subjects: eight subjects before and during application of graded lower-body negative pressure from −5 to −15 mmHg, and seven subjects before and during weight-bearing head-up tilt at 30 and 60 degrees. 2. In concomitant studies of changes in forearm vascular resistance, it was seen that mild lower-body negative pressure produced deactivation of cardiopulmonary receptors without changes in systemic blood pressure or heart rate. 3. After lower-body negative pressure, a significant decrease in carotid arterial diastolic diameter [from 0.662 ± 0.028 to 0.624 ± 0.033 cm (lower-body negative pressure −10 mmHg) and 0.640 ± 0.030 cm lower-body negative pressure −15 mmHg), P<0.001 and <0.05] was observed. 4. After head-up tilt, carotid arterial diameter was also significantly decreased at 30 and 60 degrees, whereas a significant increase in heart rate occurred only at 60 degrees and mean blood pressure did not change. 5. The study provides evidence that the geometry of the arterial wall is substantially modified by noninvasive manoeuvres such as head-up tilting and lower-body negative pressure. The latter is assumed to selectively deactivate human cardiopulmonary receptors, but the present data suggest that local changes may also influence carotid baroreceptors.
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Ye, Mao, Hangzhou Zhang, and Qingwei Liang. "Clinical Outcomes After Medial Patellofemoral Ligament Reconstruction Using Transosseous Sutures Versus Suture Anchors: A Prospective Nonrandomized Controlled Trial." Orthopaedic Journal of Sports Medicine 8, no. 5 (May 1, 2020): 232596712091711. http://dx.doi.org/10.1177/2325967120917112.
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Background: Patellar instability remains a challenging problem for orthopaedic surgeons. Recurrent patellar instability is traditionally treated with medial patellofemoral ligament (MPFL) reconstruction using a suture anchor or bone tunnel technique. Although the use of transosseous sutures was recently described for MPFL reconstruction, relevant clinical data have not been reported. Purpose/Hypothesis: The purpose of this study was to compare a new transosseous suture fixation technique with the suture anchor technique for MPFL reconstruction. The hypothesis was that reconstruction with transosseous sutures would show similar clinical results to reconstruction with suture anchors. Study Design: Cohort study; Level of evidence, 2. Methods: There were 65 patients with recurrent lateral patellar dislocations from January 2014 to December 2016 who were included in this prospective nonrandomized controlled trial. In total, 31 patients underwent MPFL reconstruction with suture anchors at the patella site (suture anchor group), while the other 34 patients underwent MPFL reconstruction with transosseous sutures (transosseous suture group). The main outcome variable (patellar redislocation) was recorded at follow-up (range, 25-60 months). The International Knee Documentation Committee (IKDC) score, Kujala score, range of motion, congruence angle, patellar tilt, redislocation rate, and complications were collected preoperatively and/or postoperatively. Results: No recurrent dislocations or other complications were observed in any of the patients. No significant differences were found at follow-up between the suture anchor and transosseous suture groups for subjective IKDC score, Kujala score, congruence angle, patellar tilt, redislocation rate, or range of motion. Conclusion: This short-term study showed that after MPFL reconstruction (suture anchors or transosseous sutures), patellar stability could be restored. With the numbers available, no significant differences in outcome scores were observed between patients in the transosseous suture and suture anchor groups.
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Pan, Qintuo, Zhengwei Yang, Xiaomeng Chen, Wenlong Wei, Zhisheng Ke, Ding Chen, Fang Huang, Junyong Cai, and Zhenquan Zhao. "Suturing technique for scleral fixation of toric intraocular lens in the traumatic aphakic eye with corneal astigmatism." European Journal of Ophthalmology 29, no. 1 (April 18, 2018): 100–105. http://dx.doi.org/10.1177/1120672118769522.
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Purpose: To describe the clinical outcomes of traumatic aphakic eyes with corneal astigmatism after using a novel technique for toric intraocular lens suture fixation. Methods: In total, 12 eyes of 12 patients who underwent a new scleral suture fixation technique of one-piece toric intraocular lens (SN6AT series, Alcon Inc., TX, USA) were included in our retrospective study. Preoperative patient status, postoperative visual acuity and refractive outcomes, postoperative intraocular lens rotation, tilt, decentration, and complications were analyzed. Results: The mean follow-up was 11.6 ± 1.0 months. The mean preoperative best-corrected visual acuity was 0.55 ± 0.32 in the logarithm of minimum angle of resolution equivalent; the postoperative best-corrected visual acuity was 0.45 ± 0.34. The mean preoperative total corneal astigmatism was 2.51 ± 1.67 D. The mean postoperative residual astigmatism was 0.77 ± 0.54 D. The mean intraocular lens rotation was 3.33° ± 1.37° (range, 1°–6°). The mean intraocular lens tilt in horizontal direction was 3.64° ± 1.02° (range, 2.6°–6.3°) and in vertical direction it was 3.19° ± 1.07 ° (range, 1.6°–5.2°). The mean intraocular lens decentration in horizontal direction was 0.14 ± 0.03 mm (range, 0.089–0.192 mm) and in vertical direction it was 0.15 ± 0.02 mm (range, 0.113–0.181 mm). One patient had mild vitreous hemorrhage and two other patients had high postoperative residual sphere and astigmatism, respectively. But no other serious complications were observed. Conclusion: Scleral suture fixation of foldable toric intraocular lens to correct corneal astigmatism can be a safe and effective alternative technique to manage traumatic aphakic eyes that lack adequate capsular support.
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Nicastro, D., A. S. Frangakis, S. Nickell, and W. Baumeister. "Three-Dimensional Structure of Neurospora Mitochondria: New Insights Provided by Electron Tomography of the Frozen-Hydrated Organelles." Microscopy and Microanalysis 5, S2 (August 1999): 452–53. http://dx.doi.org/10.1017/s1431927600015580.
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Electron tomography is the most widely applicable method for obtaining three-dimensional information by electron microscopy. It is, in fact, the only method suitable for investigating pleomorphic structures, such as many supramolecular assemblies, organelles and cells. With the recent development of automated low-dose data-acquisition schemes, it is now possible to study molecules and cells embedded in vitreous ice. This opens up new horizons for investigating the functional organization of cellular components with minimal perturbation of the cellular context.In the present study we used automated electron tomography in conjunction with cryomicroscopy to reveal the internal organization and ultrastructure of mitochondria. The whole isolated cell organelles from Neurospora crassa were quick-frozen and examined in vitrified ice. Single-axis tilt series were recorded with a Philips CM 120 Biotwin under low-dose conditions; the estimated total exposure was 10,000 e−nm−2. The tilt increment was 1° and the tilt series ranged from −65° to +65°. In order to enhance the contrast of the rather thick samples zero-loss energy filtering was employed. The images were recorded with a Ik × Ik CCD camera. The experimental setup has been described by Koster et al2 Three-dimensional reconstructions were performed by weighted backprojection. Prior to the three-dimensional visualization of 3-D data sets a denoising technique based on nonlinear anisotropic diffusion was applied (Figs. 2, 3).
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Fujiyoshi, Y., K. Mitsuoka, T. Hirai, K. Murata, A. Miyazawa, and Y. Kimura. "Characteristic feature on structure analyzed by high-resolution electron crystallography." Proceedings, annual meeting, Electron Microscopy Society of America 53 (August 13, 1995): 834–35. http://dx.doi.org/10.1017/s0424820100140543.
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The structure of bacteriorhodopsin (bR), which was already analyzed by Henderson et al., is studied by our new electron cryo-microscope equipped with Field Emission Gun (FEG) and Slow Scan CCD camera (SSCCD), because our system together with ice embedding technique enable us to solve the structure of bR at various pH conditions between pH 4.0 and 10.0. Ionization of amino acid is naturally closely related to the translocation of proton and then the function of the proton pump of bR. Therefore, observation of translocation of proton in bR is very important, if possible. Both ice embedding and high resolution techniques are essential to achieve this intention. Therefore, we intended to develop an electron cryo-microscope fit to these techniques and recently we had succeeded it.We collected whole sets of diffraction patterns for bR up to 70 degree tilt at pH 5.5 by using SSCCD, and merged these data of 300 diffraction patterns.
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Shim, Dong-Woo, Yeokgu Hwang, Yoo Jung Park, and Jin Woo Lee. "Early Outcomes of Arthroscopic Modified Brostrom Operation for Chronic Ankle Instability." Foot & Ankle Orthopaedics 2, no. 3 (September 1, 2017): 2473011417S0003. http://dx.doi.org/10.1177/2473011417s000372.
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Category: Ankle, Arthroscopy Introduction/Purpose: The gold standard for the surgical treatment of chronic lateral ankle instability is the modified Brostrom procedure. Surgery aims to re-establish ankle stability and function, without compromising ankle motion. Recently introduced all inside arthroscopic modified Brostrom procedure coincide with the goal on that aspect. The purpose of this study was to investigate the early outcomes of all inside arthroscopic modified Brostrom operation for chronic ankle instability. Methods: From January 2015 to August 2016, 30 patients were included. The visual analog scale (VAS) score, American Orthopaedic Foot & Ankle Society (AOFAS) ankle–hindfoot score, Foot and Ankle Outcome Score (FAOS), and Karlsson score were used to evaluate clinical outcomes. Anterior talar translation and talar tilt were used to evaluate radiologic outcomes. All patients had lateral ankle instability. All patients had giving way, persistent pain, and an inability to resume their preinjury activity level for more than 6 months. Clinical outcome evaluations were performed preoperatively, at 3 months and 6 months postoperatively, and at a final follow-up using the VAS score, the AOFAS ankle-hindfoot score, FAOS, and Karlsson score. Radiologic outcome evaluations were performed preoperatively and at 1 year postoperatively at final follow-up using anterior talar translation, and talar tilt angle. Results: Thirty patients (19 males and 11 females) were followed up for a mean of 11.0 (range 4 – 23) months. The VAS, AOFAS, 1 FAOS subscale (Quality-of-life) and the Karlsson scores were improved significantly at the each follow-up period of 3 month, 6 month and 1 year postoperatively. Other 4 subscales of FAOS showed no significant outcomes (Table 1). The mean anterior talar translation and talar tilt showed significant improvements from 5.8 mm (SD = 0.4) and 7.9° (SD = 1.0) to 5.3 mm (SD = 0.3) and 5.7° (SD = 0.6) at the final follow-up each (p = 0.034, p=0.034). Conclusion: The arthroscopic modified Brostrom technique could be a viable alternative to the gold-standard open modified Brostrom procedure for anatomic repair of chronic lateral ankle instability. It can yield outstanding functional and clinical outcomes without adverse effects in terms of pain.
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Hoffmann, Jeffrey D., Jeremy Stewart, Nicholas Kusnezov, John Dunn, and Miguel Pirela-Cruz. "Radial Plate Fixation: A Novel Technique for Distal Radius Fractures." HAND 12, no. 5 (October 22, 2016): 471–75. http://dx.doi.org/10.1177/1558944716669136.
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Background: Distal radius fractures represent a common fracture pattern frequently treated with volar locked plating for fixation. However, other methods may provide equivalent outcomes and minimize risks associated with the volar approach and hardware placement. One such method is the radial plate. Methods: After confirmation of institutional board review, we retrospectively reviewed data from 7 patients with our primary functional outcomes measured by Mayo wrist and Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores. The most recent radiographic and motion parameters were recorded. Results: Mean age at time of injury was 49 years (range, 19-68 years) with clinical follow-up of 81.6 months (range, 43.5-95.5 months). Five patients had good to excellent outcomes with a mean QuickDASH score of 0.92 for those patients. The mean QuickDASH score for all patients was 18.5. Mean radial height, inclination, and volar tilt were within 5% of the contralateral side. Standard deviation values for radiographic measures and clinical range of motion indicate significant variability in our data set. Conclusions: Although the results are mixed, our small cohort indicates radial plate fixation could provide a viable alternative to volar plate fixation of distal radius fractures. Further prospective investigation is warranted to better describe long-term outcomes using this technique.
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Ehsani, Mohammad R., and Hamid Saadatmanesh. "Fiber Composites: An Economical Alternative for Retrofitting Earthquake-Damaged Precast-Concrete Walls." Earthquake Spectra 13, no. 2 (May 1997): 225–41. http://dx.doi.org/10.1193/1.1585943.
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A new approach for seismic retrofitting of lightly-reinforced precast-concrete walls is presented. The technique involves epoxy bonding the reinforcing material (composite fabric) to the exterior surface of the wall. The flexible light-weight fabrics are extremely strong in tension and can significantly increase the flexural and shear capacity of the member. The thin composite fabrics cause little increase in the weight and thickness of the wall, causing little change to the inertial loads and eliminating the need for strengthening of the footings. Following the January 17, 1994 Northridge earthquake, this technique was applied to a tilt-up concrete building in southern California. The method proved to be the most cost-effective alternative to repair this damaged building in a very short time. More than 20,000 ft.2 of wall surface area were strengthened, making this project the largest reported application of this technique. This paper discusses some of the design considerations and the strengthening of the damaged building.
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Bhushan, Bharat, and Victor Multanen. "Designing liquid repellent, icephobic and self-cleaning surfaces with high mechanical and chemical durability." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 377, no. 2138 (December 24, 2018): 20180270. http://dx.doi.org/10.1098/rsta.2018.0270.
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Liquid repellent, icephobic and self-cleaning surfaces are of interest in industrial applications, including solar panels, self-cleaning windows, wind turbines, and automotive and aerospace components. In this study, a coating using a simple and scalable fabrication technique was used to produce superliquiphobic surfaces with a low tilt angle. The coating comprises hydrophobic SiO 2 nanoparticles with a binder of methylphenyl silicone resin to achieve superhydrophobicity. After ultraviolet–ozone treatment of the coating, an additional coating of fluorosilane was deposited to achieve superliquiphobicity with low tilt angle. Data for these coatings are presented showing the ability to repel water and oil, anti-icing properties down to −60°C, self-cleaning, and the ability to maintain superliquiphobicity in hot environments up to about 95°C, after soaking in deionized water for more than 200 h at room temperature and for about 50 h at 50°C and 70°C, and in chemical environments with low pH values. The coatings were found to be mechanically durable. Detailed characterization for anti-icing provides an insight into the mechanisms of icephobicity. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology’.
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Goto, Akira, Tsuyoshi Murase, Kunihiro Oka, and Hideki Yoshikawa. "USE OF THE VOLAR FIXED ANGLE PLATE FOR COMMINUTED DISTAL RADIUS FRACTURES AND AUGMENTATION WITH A HYDROXYAPATITE BONE GRAFT SUBSTITUTE." Hand Surgery 16, no. 01 (January 2011): 29–37. http://dx.doi.org/10.1142/s0218810411005023.
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Treatment of distal radius fractures with a volar fixed angle plate achieves sufficient stabilisation and permits early physical exercise. However, secondary displacement after surgery sometimes occurs in elderly patients with a metaphyseal comminution and/or cases in which the subchondral support pegs were not placed immediately below the subchondral zone.We treated elderly patients suffering from distal radius fractures with metaphyseal comminution, using both volar fixed angle plate with or without augmentation with a hydroxyapatite bone graft substitute to investigate the benefit of augmentation for maintaining a fracture reduction. We evaluated the differences among radiographic parameters including palmar tilt, radial inclination, and ulnar variance on immediate postoperative and final follow-up radiographs to analyse the maintenance of the initial reduction.There were no significant differences between the two groups in terms of palmar tilt (P = 0.80) and radial inclination (P = 0.17); however, ulnar variance increased significantly in the group treated with a volar fixed angle plate without augmentation (P < 0.05).It might be useful to use a combination technique of a locking plate system and the hydroxyapatite bone graft substitute as augmentation to treat distal radius comminuted fractures in elderly patients.
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Kastrup, J., T. Nørgaard, H. H. Parving, and N. A. Lassen. "Decreased distensibility of resistance vessels of the skin in type 1 (insulin-dependent) diabetic patients with microangiopathy." Clinical Science 72, no. 1 (January 1, 1987): 123–30. http://dx.doi.org/10.1042/cs0720123.
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1. The distensibility of the resistance vessels of the skin at the dorsum of the foot was determined in 11 long-term type 1 (insulin-dependent) diabetic patients with nephropathy and retinopathy, nine short-term type 1 diabetic patients without clinical microangiopathy and in nine healthy non-diabetic subjects. 2. Blood flow was measured by the local 133Xexenon washout technique in a vascular bed locally paralysed by the injection of histamine. Blood flow was measured before, during and after a 40 mmHg increase of the vascular transmural pressure, induced by head-up tilt. 3. The mean increase in blood flow during headup tilt was only 24% in diabetic subjects with and 48% in diabetic patients without clinical microangiopathy, compared with 79% in normal non-diabetic subjects (P < 0.0005 and P < 0.05, respectively). 4. An inverse correlation between microvascular distensibility and degree of hyalinosis of the terminal arterioles in biopsies from the skin was demonstrated (r = − 0.57, P < 0.001). 5. Our results suggest that terminal arteriolar hyalinosis reduces the microvascular distensibility and probably increases the minimal vascular resistance, thereby impeding hyperaemic responses.
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Sheen, Maw Tyan. "Design and Simulation of Laser Module Packaging of TO-Based Butterfly-Type Structures." Applied Mechanics and Materials 284-287 (January 2013): 456–60. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.456.
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A novel design of butterfly-type laser module packaging using transistor outline (TO) structures is proposed. The cost down and fabrication time savings for fabrication of the module packagings are obtained, and the yield rate and the coupling efficiency of butterfly-type laser module are enhanced. The post-weld-shift (PWS) correction uses laser hammer technique in coaxial-type laser modules is studied experimentally and numerically. Experimental results show that the PWS of a coaxial laser module welded by a three-beam laser system can be corrected by applying laser hammer on the opposed tilt direction of welded components to realign the fiber back closer to its optimum position. In addition, the coupling efficiency increased up to 20 % was obtained by laser hammer.Further, the numerical calculations of the finite-element method analysis was in good agreement with the experimental results of the tilt angles of PWS ranged from 0.4 x 10-2 to 3.4 x 10-2 degree. The results of this study showed that the PWS state of being properly adjusted in coaxial laser module packages and led to fabricating reliable optoelectronic packaging with high yield.
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Abe, Yoshihiro, Masahiro Suzuki, and Hiromasa Wakita. "Dual Plating Technique for Volar Rim Fracture of the Distal Radius Using DePuy-Synthes 2.0 m and 2.4 mm Locking Plates." Journal of Hand Surgery (Asian-Pacific Volume) 22, no. 04 (November 9, 2017): 423–28. http://dx.doi.org/10.1142/s0218810417500447.
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Background: To assess the surgical results of distal radius fractures with the involvement of a volar rim fragment using the DePuy-Synthes 2.0 mm and 2.4 mm locking plates.Methods: Subjects were six women and one man of average age 57 years (range, 31–83 y) and a mean follow-up period of 9 months (range, 5–19 mo) with AO B3 (volar shearing) distal radius fractures. Time of the procedure, physical examination of wrist range of motion, grip strength compared with the contralateral healthy wrist, and radiographic evaluation (volar tilt, radial inclination, and ulnar variance) were evaluated. The Visual Analog Scale (VAS: 0 points represents no pain, 100 points represents the worst pain possible) and the Quick Disability of the Arm, Shoulder, and Hand questionnaire (QuickDASH, 0 = no disability, 100 = extreme disability) were completed by patients at the final follow-up.Results: The average time of the procedure was 74 min. There were no perioperative complications. Average radiographic measures were: volar tilt, 8°; radial inclination, 23°, and ulnar variance, 0 mm. Wrist range of motion averaged 63° in wrist extension (range, 55–80°) and 55° in wrist flexion (range, 45–65°). Grip strength averaged 81% of the contralateral side at final evaluation (range, 67–100%). The mean QuickDASH score was 3.0 points (range, 0–9.1 points) and the mean VAS for pain was 9.3 at final follow-up.Conclusions: Open reduction internal fixation with the DePuy-Synthes 2.0 mm and 2.4 mm locking plates is an effective means of fixing a distal radius fracture that includes a volar rim fragment without interfering with flexor tendon gliding.
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McNamara, Colin, Eric Slotkin, Amar Mutnal, Wael Barsoum, Juan Suarez, and Preetesh Patel. "Dislocation Rates following Anterior Approach THA: The Role of Functional Pelvic Tilt." Journal of Hip Surgery 01, no. 04 (December 2017): 194–99. http://dx.doi.org/10.1055/s-0038-1635101.
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AbstractVarious target zones for acetabular cup placement have been suggested to minimize dislocation following total hip arthroplasty (THA), though dislocations occur despite proper positioning. The authors have reported accuracy of fluoroscopic guidance in cup positioning during direct anterior approach (DAA) THA when using a standardized fluoroscopic technique functional pelvic tilt. They believe that cup placement with regard to functional pelvic tilt, rather than static reference frames, will offer improved stability. A cohort of 1,597 fluoroscopy-assisted DAA primary unilateral THA patients was prospectively followed for a minimum of 1 year and component position measured radiographically. Target cup position was based off the standing anteroposterior pelvis while using conventional safe zone parameters. Dislocation rate was assessed. Average follow-up was 13.1 months (range 1–6 years). The mean abduction angle was 37.7° and the mean anteversion angle was 16.2°. Overall, 1,517 (95.0%) fell within the targeted abduction range, 1,528 (95.7%) fell within the targeted anteversion range, and 1,456 (91.2%) simultaneously met both criteria. There were nine dislocations, eight within the combined safe zone, for a dislocation rate of 0.56%. Fluoroscopy can improve accuracy and precision of cup placement in DAA THA. Conventional safe zone parameters applied using functional pelvic tilt resulted in a low dislocation rate, with most dislocations occurring within the safe zone. Using a dynamic functional safe zone may further reduce dislocation rates after DAA THA, though other factors that contribute to instability must be accounted for in future studies. This study had a III level of evidence.
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Zhang, Hangzhou, Mao Ye, and Qingwei Liang. "Clinical Outcomes After Medial Patellofemoral Ligament Reconstruction With Suture Fixation of the Gracilis Tendon via Transosseous Tunnels." Orthopaedic Journal of Sports Medicine 8, no. 2 (February 1, 2020): 232596711990037. http://dx.doi.org/10.1177/2325967119900373.
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Background: Several fixation methods have been introduced in medial patellofemoral ligament (MPFL) reconstruction. However, the optimal management of patients with recurrent patellar dislocation remains controversial. Purpose: To present a case series with a minimum 2-year follow-up of 29 patients with recurrent patellar dislocation who underwent a new transosseous suture fixation technique for MPFL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: From January 2014 through February 2016, a total of 29 patients with recurrent patellar dislocation for which the MPFL was reconstructed with transosseous suture patellar fixation were studied. All patients were available for follow-up (mean, 37.52 months; range, 26-48 months). The patellar attachment was fixed by transosseous patellar sutures. The International Knee Documentation Committee (IKDC) subjective knee score, Kujala score, Tegner score, range of motion, congruence angle, patellar tilt angle, and complications were assessed both pre- and postoperatively. Results: No recurrent dislocation was observed in any of the 29 patients for a minimum of 2 years. All outcome scores improved significantly from preoperatively to postoperatively: the average IKDC subjective knee evaluation score from 53 to 87, Kujala from 54 to 90, Lysholm from 50 to 89, and Tegner from 3 to 5 ( P < .001 for all). The congruence angle significantly decreased from 22° preoperatively to –3° postoperatively, and the patellar tilt angle (Merchant) decreased from 23° preoperatively to 5° postoperatively ( P < .001 for both). In total, 25 patients (25/29; 86.21%) were completely pain-free when performing activities of daily living at the last follow-up, and 27 patients (93.1%) rated themselves as very satisfied or satisfied with the results. Conclusion: In patients with chronic recurrent patellar dislocation, transosseous patellar suture fixation for MPFL reconstruction can significantly improve patellar stability and achieve good results at short-term follow-up.
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Schlösser, Tom P. C., Enrique Garrido, Athanasios I. Tsirikos, and Michael J. McMaster. "Health-related quality of life and sagittal balance at two to 25 years after posterior transfixation for high-grade dysplastic spondylolisthesis." Bone & Joint Open 2, no. 3 (March 1, 2021): 163–73. http://dx.doi.org/10.1302/2633-1462.23.bjo-2020-0194.r1.
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Aims High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique. Methods SRS-22r and full-spine lateral radiographs were collected for the 28 young patients (age 13.4 years (SD 2.6) who underwent surgery for high-grade dysplastic spondylolisthesis in our centre (Scottish National Spinal Deformity Service) between 1995 and 2018. The mean follow-up was nine years (2 to 25), and one patient was lost to follow-up. The standard surgical technique was an all-posterior, partial reduction, and S1 to L5 transfixation screw technique without direct decompression. Parameters for segmental (slip percentage, Dubousset’s lumbosacral angle) and regional alignment (pelvic tilt, sacral slope, L5 incidence, lumbar lordosis, and thoracic kyphosis) and global balance (T1 spino-pelvic inclination) were measured. SRS-22r scores were compared between patients with a balanced and unbalanced pelvis at final follow-up. Results SRS-22r domain and total scores improved significantly from preoperative to final follow-up, except for the mental health domain that remained the same. Slip percentage improved from 75% (SD 15) to 48% (SD 19) and lumbosacral angle from 70° (SD 11) to 101° (SD 11). Preoperatively, 35% had global imbalance, and at follow-up all were balanced. Preoperatively, 63% had an unbalanced pelvis, and at final follow-up this was 32%. SRS-22r scores were not different in patients with a balanced or unbalanced pelvis. However, postoperative pelvic imbalance as measured by L5 incidence was associated with lower SRS-22r self-image and total scores (p = 0.029). Conclusion In young patients with HGDS, partial reduction and transfixation improves local lumbosacral alignment, restores pelvic, and global balance and provides satisfactory long-term clinical outcomes. Higher SRS-22r self-image and total scores were observed in the patients that had a balanced pelvis (L5I < 60°) at two to 25 years follow-up. Cite this article: Bone Jt Open 2021;2(3):163–173.
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Takahashi, Mitsuhiko, Ichiro Tonogai, and Koichi Sairyo. "TREATMENT OF EXTRA-ARTICULAR DISTAL RADIAL MALUNION WITH PERCUTANEOUS OSTEOTOMY AND AN INTRAMEDULLARY IMPLANT." Hand Surgery 19, no. 02 (January 2014): 217–22. http://dx.doi.org/10.1142/s0218810414720137.
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Purpose: Distal radius malunion is often seen after distal radius fracture. We performed a less invasive but secure corrective surgery using an intramedullary implant combined with percutaneous osteotomy. The purpose of this study was to evaluate the results of this surgical technique. Patients and methods: Three patients with malunion of a distal radius fracture were included. We assessed the wrist joint disability scores pre-operatively and at the final follow-up an average of 21 months after surgery. We also performed radiological assessments of volar tilt, radial inclination, and ulnar variance. Results: All three patients achieved excellent clinical results with an average joint disability score of 93.3 at the final follow-up. The radiological parameters improved without any post-operative correction loss. Discussion: Intramedullary implant combined with percutaneous osteotomy provides sufficient stability after correction of distal radius malunion and avoids the complications associated with the use of a volar plate.
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DELLA SANTA, D., and A. CHAMAY. "Radiological Evolution of the Rheumatoid Wrist after Radio-Lunate Arthrodesis." Journal of Hand Surgery 20, no. 2 (April 1995): 146–54. http://dx.doi.org/10.1016/s0266-7681(05)80041-5.
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Radio-lunate arthrodesis of the rheumatoid wrist is an established technique which has been in use for more than 12 years. The evolution of 26 operated wrists and 20 non-operated wrists has been studied with a mean follow-up of 5 years. The results show that although radio-lunate arthrodesis can prevent dislocation of an unstable wrist, it cannot prevent deterioration. Collapse, ulnar translation, tilt of the lunate, and the inter-carpal instability continued with time, whether the wrists were operated on or not. The speed of deterioration was dependent on the type of rheumatoid arthritis and is faster in the disintegration type than in the osteoarthritis or the ankylosis type. The technique is applicable to the osteoarthritis type of rheumatoid arthritis, in the middle stage (2 to 4a according to the Larsen-Alnot classification). At that stage, the ankylosis type and the disintegration type, and the osteoarthritis type at an advanced stage, are better treated by total arthrodesis or total prosthetic arthroplasty.
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Panni, Alfredo Schiavone, Mahbub Alam, Simone Cerciello, Michele Vasso, and Nicola Maffulli. "Medial Patellofemoral Ligament Reconstruction With a Divergent Patellar Transverse 2-Tunnel Technique." American Journal of Sports Medicine 39, no. 12 (August 25, 2011): 2647–55. http://dx.doi.org/10.1177/0363546511420079.
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Background: The medial patellofemoral ligament (MPFL) is the primary passive restraint to lateral patellar dislocation and there is increasing awareness of its role in recurrent lateral patellar instability. Purpose: This study was conducted to prospectively analyze the functional results of a modified MPFL reconstruction technique in recurrent patellar dislocation. Study Design: Case series; Level of evidence, 4. Methods: Forty-eight patients (51 knees) with at least 3 episodes of lateral patellar dislocation who had been treated with a 6-month rehabilitation protocol were included in this study. All patients practiced sports regularly. Reconstruction was with a semitendinosus tendon using a divergent 2-tunnel technique. Outcome was evaluated with the Kujala, Larsen, modified Lysholm, and Fulkerson outcome scores. Patient satisfaction with range of motion, pain, and sporting activities was also assessed. Results: Three patients were lost at the final follow-up, giving a follow-up rate of 94%. The mean follow-up was 33 months. There was no patella dislocation postoperatively. The mean Kujala score improved significantly ( P < .01) from 56.7 ± 17.7 (2 × standard deviation) preoperatively to 86.8 ± 14.4 postoperatively. The mean Larsen score improved significantly ( P < .01) from 12.4 ± 3.2 to 17.1 ± 2.7. The mean Fulkerson score improved significantly ( P < .01) from 59.2 ± 21.8 to 90.1 ± 14. The mean modified Lysholm score improved significantly ( P < .01) from 57.6 ± 19.6 to 88.1 ± 16.2. Sixty-four percent of patients returned to the same type of sport at the same level, 16% reduced the level or type of sport for reasons unrelated to the surgery, while 20% reduced the level of sport or changed it for reasons related to surgery. Eighty-seven percent were either satisfied or very satisfied with the pain relief achieved. The patellar tilt decreased significantly from a preoperative mean of 11.1° to 8.9° at the last follow-up ( P = .02). The mean preoperative Insall-Salvati ratio of 1.1 decreased to 1.06, although the change was not significant ( P = .1). Conclusion: The results of modified MPFL reconstructions are encouraging, with minimal risks of redislocation and an overall patient satisfaction rate of over 80%. These early and medium-term results are comparable with those of other MPFL reconstruction techniques reported in the literature.
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McCormack, Daniel, Sayyied J. Kirmani, Sheweidin Aziz, Radwane Faroug, and Jitendra Mangwani. "The Role of Deep Deltoid Ligament in Ankle Fracture Stability: A Biomechanical Cadaveric Study." Foot & Ankle Orthopaedics 5, no. 4 (October 1, 2020): 2473011420S0035. http://dx.doi.org/10.1177/2473011420s00350.
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Category: Ankle; Basic Sciences/Biologics; Trauma Introduction/Purpose: Supination-external rotation (SER) injuries make up 80% of all ankle fractures. SER stage 2 injuries (AITFL and Weber B) are considered stable. SER stage 3 injury includes disruption of the posterior malleolus (or PITFL). In SER stage 4 there is either medial malleolus fracture or deltoid injury. SER 4 injuries have been considered unstable, requiring surgery. The deltoid ligament is a key component of ankle stability, but clinical tests to assess deltoid injury have low specificity. This biomechanical cadaveric study specifically investigates the role of the components of the deep deltoid ligament in the stabillity of SER ankle fractures. Methods: In the first phase of the study, three specimens were utilised to standardise dissection of the deltoid ligament and creation and fixation of SER ankle fracture. In phase two, four matched pairs (8 specimens) were tested using this standardised protocol (Figure1). Specimens were sequentially tested for stability when axially loaded with a custom rig with up to 750N. Specimens were tested with: ankle intact; lateral injury (AITFL and Weber B); additional posterior injury (PITFL); additional anterior deep deltoid; additional posterior deep deltoid; lateral side ORIF. Clinical photographs and radiographs were recorded at each stage. In addition, dynamic stress radiographs were performed after sectioning the deep deltoid and following fracture fixation to assess talar tilt in eversion. Results: All specimens behaved in an identical manner when subjected to this standardised protocol. When the posterior deep deltoid ligament was intact, the ankle remained stable when loaded and showed no talar tilt on dynamic stress test. Once the posterior deep deltoid ligament was sectioned, there was demonstrable instability in all specimens. Surgical stabilisation of the lateral side using standard technique with a plate prevented talar shift but not talar tilt. In adequately stabilised ankle specimens, there was no loss of fixation on axial loading. Conclusion: This biomechanical cadaveric experiment demonstrates that under the standardised test conditions, all SER fracture ankle specimens with an intact posterior deep deltoid ligament behaved as stable injuries. The posterior portion of the deep deltoid ligament is a crucial structure in conferring stability to SER stage 4 injuries. The clinical implication of this is that when the posterior deep deltoid ligament is intact, SER fractures may be managed without surgical intervention in a plantigrade cast. We also conclude that without immobilisation, the talus may tilt in the mortise risking long-term deltoid incompetence.
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Toyoshima, Chikashi. "Three-dimensional Image Analysis of Tubular Crystals of Membrane Proteins in Ice." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 242–43. http://dx.doi.org/10.1017/s0424820100179968.
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Frozen-hydrated electron microscopy is a powerful method that allows us to preserve biological macromolecules in physiological ionic conditions and obtain the density (Coulomb potential) maps directly. Changes in quarternary structure in different conditions have been demonstrated using this technique for the gap junction (1) and the nicotinic acetylcholine receptor (2). Since the image contrast originates from the difference in density between the specimen and ice, the method has a considerable advantage over conventional methods in resolving structure inside the lipid bilayer, especially when molecules are arranged in a helical array to form tubular crystals. The molecules in a helical array present many different views to the incident electron beam, hence the electron micrograph actually contains a large amount of three-dimensional information. By using helical image analysis, it is possible to obtain a three-dimensional image from a single micrograph in many instances. Furthermore, the data is complete: There is no "missing cone" problem arising from a limited angle of tilt; the resolution in the reconstructed image is isotropic. The mean (radial) density distribution is available from equatorial data; thus the value in the map is an absolute measure of the density.We have been analysing tubular crystals of the nicotinic acetylcholine receptor from electric ray and the calcium ATPase from rabbit sarcoplasmic reticulum. Helical image analysis at 17 Å resolution of the narrow tubes embedded in ice has allowed two leaflets of the lipid bilayer to be resolved clearly (2). The lipid bilayer was not resolved in previous tilt reconstructions using flattened tubes at a similar (in plane) resolution and up to 60 degrees tilt (3).
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Ledgeway, T., and B. J. Rogers. "Measurements of the Relative Tilt of Corresponding Vertical and Horizontal Meridians in the Two Eyes as a Function of Elevation and Eccentricity in the Visual Field." Perception 26, no. 1_suppl (August 1997): 226. http://dx.doi.org/10.1068/v970097.
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Helmholtz first reported that when the horizontal meridians of the two eyes are aligned, the vertical meridians of the two eyes are tilted outwards (with respect to each other) by approximately 2°. We adapted Nakayama's technique (1977 Proceedings of the Society of Photo-Optical Instrument Engineers120 2 – 9) using the minimal apparent motion of alternating dichoptic images to measure the relative tilt of corresponding vertical and horizontal meridians located up to 20 deg away from the fovea. Observers were presented with the alternating dichoptic images of a pair of dots or a pair of extended lines which had a relative tilt (binocular orientation difference) of between −5° and +5°. The images were alternated at a rate of 0.2 Hz. Observers were asked to select the pair of images which produced the smallest amount of apparent orientation change. The vergence angle of the binocularly visible fixation point was varied between 28 cm and infinity. On the assumption that minimal apparent motion is a valid indicator of binocular correspondence, the corresponding vertical meridians of the two eyes remained offset by around 2 deg even when they were located 20 deg eccentrically. The corresponding horizontal meridians remained approximately aligned even when they were elevated by up to 20 deg. Corresponding horizontal meridians were altered when the vergence angle was changed but corresponding vertical meridians were unaffected for most individuals. With the eyes held in an elevated position, both vertical and horizontal meridians were altered by a similar amount when the vergence angle was altered, indicating a change in cyclovergence.
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Wilkerson, M. Keith, Lisa A. Lesniewski, Elke M. Golding, Robert M. Bryan, Aamir Amin, Emily Wilson, and Michael D. Delp. "Simulated microgravity enhances cerebral artery vasoconstriction and vascular resistance through endothelial nitric oxide mechanism." American Journal of Physiology-Heart and Circulatory Physiology 288, no. 4 (April 2005): H1652—H1661. http://dx.doi.org/10.1152/ajpheart.00925.2004.
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Elevations in arterial pressure associated with hypertension, microgravity, and prolonged bed rest alter cerebrovascular autoregulation in humans. Using head-down tail suspension (HDT) in rats to induce cephalic fluid shifts and elevate arterial pressure, this study tested the hypothesis that 2-wk HDT enhances cerebral artery vasoconstriction and that an enhanced vasoconstriction described in vitro will alter regional cerebral blood flow (CBF) and vascular resistance (CVR) during standing and head-up tilt. To test this hypothesis, basal tone and vasoconstrictor responses to increases in transmural pressure, shear stress, and K+ were determined in vitro in middle cerebral arteries (MCAs) from HDT and control rats. All in vitro measurements were done in the presence and absence of the nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (l-NAME; 10−5 M) and with endothelium removal. Endothelial NOS (eNOS) mRNA and protein expression levels were measured by RT-PCR and immunoblot, respectively. Regional CBF and CVR were determined with a radiolabeled tracer technique and quantitative autoradiography. Basal tone and all vasoconstrictor responses were greater in MCAs from HDT rats. l-NAME and endothelium removal abolished these differences between groups, and HDT was associated with lower levels of MCA eNOS protein. CBF in select regions was lower and CVR higher during standing and head-up tilt in HDT rats. These results indicate that chronic cephalic fluid shifts enhanced basal tone and vasoconstriction through alterations in the eNOS signaling mechanism. The functional consequence of these vascular alterations with HDT is regional elevations in CVR and corresponding reductions in cerebral perfusion.
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Kang, Chan, Gi Soo Lee, Jeong-kil Lee, Ki Jun Ahn, Sung Jin Hwang, Young Cheol Park, Hyung Jin Chung, and Jae Hwang Song. "The Augmentation Technique for Anatomical Reduction of Shortened Lateral Ligament Complex in Modified Broström Procedure." Foot & Ankle Orthopaedics 4, no. 4 (October 1, 2019): 2473011419S0024. http://dx.doi.org/10.1177/2473011419s00241.
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Category: Ankle, Sports Introduction/Purpose: The modified Broström procedure(MBP) is clinically standard surgical treatment of lateral ankle instability with or without subfibular ossicle. But if there is a large ossicle or distal malposition of lateral ligament complex(LLC), it can result in a lack of remnant ligamentous tissue and leave gap that may not be approximated. Thus, we have proposed an augmentation technique for anatomical reduction of shortened LLC in MBP and evaluated radiologic and clinical findings. Methods: From December 2013 to February 2018, fifty two of fifty six patients who had shortened LLC treated with the augmentation technique with MBP using absorbable suture material. LLC(anterior talofibular ligament(ATFL) and calcaneofibular ligament(CFL)) was exposed after inferior extensor retinaculum(IER) was incised. Then, we identified shortened LLC. Then, we incised just distal part of connecting soft tissue of ATFL and CFL additionally for reduction to anatomic footprint. After confirmation of reduction, 4 or 5 bone tunnels were made and deep fiber of LLC was repaired tightly with foot in neutral dorsiflexion and 5° eversion by using horizontal mattress and simple stitch. Then, superficial fiber with capsule of LLC was repaired by priorly tied suture without cutting. Finally, IER was reinforced. Results: Mean AOFAS scores improved from 59.2 to 91.4 at final follow-up. Mean Karlsson scores also improved from 61.3 to 89.5 at final follow-up. Mean talar tilt angles were 13.4° preoperatively and 5.8° postoperatively. Mean anterior talar translations were 9.1 mm preoperatively and 5.7 mm postoperatively. There was significant improvement between preoperative & final follow- up in all parameters (all p < .05). During follow up, no clinical symptom like experience of instability or irritation of skin were encountered after surgery, and no patient underwent revision lateral ligament surgery. Conclusion: Augmentation technique of LLC flap in MBP enabled anatomical reduction of shortened LLC to footprint, and provided good clinical and radiographic outcomes. If further comparative and mechanical study is supported, this technique would be a good treatment option.
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AL-SHAHEEN, Ahmad Hashim. "GAIN AND BANDWIDTH ENHANCEMENT OF RECTANGULAR PATCH MICROSTRIP ANTENNA." Periódico Tchê Química 17, no. 34 (March 20, 2020): 512–19. http://dx.doi.org/10.52571/ptq.v17.n34.2020.536_p34_pgs_512_519.pdf.
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Microstrip antennas are very popular for sending and transmitting electromagnetic waves in many communication systems. The microstrip antenna has advantages and disadvantages, like any other antennas. There many benefits like low weight, low profile planar configuration, low costs of fabrication, and easy to connect with microwave circuits. The patch antenna is suited for applications, which are wireless communications systems, cellular phones, pagers, radar systems, and satellite communications systems. The proposed antenna is designed and simulated via HFSS. The antenna substrate, which is between the two conductors’ patch and ground plane, is Duroid of the dielectric constant of δr = 2.2 and tangent loss of tan δ = 0.0009, the dimensions are 20 mm for both length and width; the height is 1.5 mm. The patch of sizes is 16 mm and 15 mm for length and width, respectively. In this article the new technique has been introduced to enhance the gain and bandwidth of the rectangular patch microstrip antenna, a new technique is based on creating a patch as a monopole, the parametric study done by varying the parameter δ is the height of the patch concerning the substrate. The gain and bandwidth are increased when the angle between the patch edge and the substrate is increased. While the benefit increased for tilt angle up to 20° and then decreased smoothly with angle increased, the simulated results show a significant change in the gain and bandwidth comparison with traditional rectangular patch microstrip antenna. The results show an increasing tilt angle increased bandwidth and gain. This antenna can be used in the K band for wireless communication applications.