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Artículos de revistas sobre el tema "Centrifugation"

Autor: Grafiati

Publicado: 4 de junio de 2021

Última modificación: 9 de junio de 2025

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1

Daramola, James Ola. "Effect of Centrifugation on Motility, Sperm Capacitation and Acrosome Reaction in Soy Bean and Avocado Seed Milk Extenders of Cryopreserved Goat Spermatozoa." Agricultura Tropica et Subtropica 50, no. 1 (March 1, 2017): 13–18. http://dx.doi.org/10.1515/ats-2017-0002.

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Abstract Removal of seminal plasma by centrifugation (0 centrifugation, 1 centrifugation, 2 centrifugations, 3 centrifugations) and preservation in two different tris-extenders viz., avocado seed milk (ASM) and soy bean milk (SBM) based extenders were studied for their ability to support motility, in vitro capacitation and acrosome reaction of spermatozoa obtained from West African Dwarf (WAD) goat bucks during cryopreservation. Semen samples collected with the aid of artificial vagina were centrifuged for one, two and three times. The centrifuged samples were diluted with the two tris-extenders each containing 20 mL of avocado seed milk and soybean milk and cryopreserved for 30 days. The results showed higher (P < 0.05) sperm motility (P < 0.05) with increased centrifugation times. Spermatozoa that were centrifuged had higher (P < 0.05) percentage of acrosome reaction and capacitation with increased centrifugation times compared to the control. Optimal improvement in these parameters was obtained with increased centrifugation times. The findings revealed that removal of seminal plasma by centrifugation improved sperm quality of WAD goat bucks during cryopreservation and optimum improvement was achieved consistently with 3 centrifugations.

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2

Gallagher, Sean R. "Centrifugation." Current Protocols Essential Laboratory Techniques 00, no. 1 (January 2008): 5.1.1–5.1.16. http://dx.doi.org/10.1002/9780470089941.et0501s00.

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3

Jo, Chris H., Young Hak Roh, Ji Eun Kim, Sue Shin, and Kang Sup Yoon. "Optimizing Platelet-Rich Plasma Gel Formation by Varying Time and Gravitational Forces During Centrifugation." Journal of Oral Implantology 39, no. 5 (October 1, 2013): 525–32. http://dx.doi.org/10.1563/aaid-joi-d-10-00155.

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Despite the increasing clinical use of topical platelet-rich plasma (PRP) to enhance tissue healing and regeneration, there is no properly standardized method of autologous PRP gel preparation. This study examined the effect of the centrifugation time and gravitational force (g) on the platelet recovery ratio of PRP and determined the most effective centrifugation conditions for preparing PRP. Two-step centrifugations for preparing PRP were used in 39 subjects who had consented prior to the study's start. The separating centrifugation (Step 1, used to separate whole blood into its two main components: red blood cells and plasma) was tested from 500g to 1900g at 200g increments for 5 minutes (min), and from 100g to 1300g at 200g increments for 10 minutes. After separating centrifugation, upper plasma layer was transferred to another plain tube for the condensation centrifugation and remaining lower cell layer was discarded. The condensation centrifugation (Step 2, used to condense the platelets in the separated plasma) was tested at 1000g for 15 min, 1500g for 15 min, 2000g for 5 min and 3000g for 5 min, additionally at 1000g for 10 min and 1500g for 10 min. Platelet gelation was induced by adding 10% calcium gluconate to final PRP with volume ratio of 1:10. The optimal separating centrifugation conditions were followed by 900g for 5 minutes and the condensation conditions were followed by 1500g for 15 minutes, of which recovery ratios were 92.0 ± 3.1% and 84.3 ± 10.0%, respectively.

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4

Yuliandari, Aisyara, Prima Octafia Damhuri, Tiur Sherly Margaretta, Sarah Ester Priskilla, and Hartini H. "EVALUATION OF PLATELET RICH PLASMA (PRP) PREPARATION PROCEDURE." JURNAL ANALIS LABORATORIUM MEDIK 8, no. 2 (December 19, 2023): 94–100. http://dx.doi.org/10.51544/jalm.v8i2.4509.

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The success of PRP therapy in repairing tissue damage is influenced by the PRP preparation procedure. Currently, there’s no standardization of PRP preparation procedures, and various techniques are used, such as the use of anticoagulants and different centrifugation speeds. This study aimed to evaluating the PRP preparation procedures based on the centrifugations steps (single and double centrifugation) and the use of anticoagulants variation (sodium citrate, EDTA and ACD-A). This study was an experimental study and used blood samples from respondents. The selected respondents must meet inclusion and exclusion criteria. The treatment groups in this study were the single centrifugation group and the double centrifugation group. Each group will be divided into 3 subgroups with different anticoagulant usage (sodium citrate, EDTA and ACD-A). Statistical analysis results showed a significant difference in the mean platelet count in the sodium citrate , EDTA, ACD-A groups with single and double centrifugation steps. Evaluation of platelet preparation procedures in this study, a higher platelet count was obtained, specifically in the sodium citrate group (494 x 103 cells/µL), EDTA group (829.4 x 103 cells/µL), and ACD-A group (607.1 x 103 cells/µL), compared to single centrifugation in the sodium citrate group (354.8 x 103 cells/µL), EDTA group (408.1 x 103 cells/µL), and ACD-A group (390.6 x 103 cells/µL). The highest platelet count in PRP was achieved with the preparation procedure using EDTA as the anticoagulant with double centrifugation. Further research is necessary to evaluate PRP preparation procedures regarding the concentration of growth factors present in PRP.

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5

Janky, Kristen L., and Neil T. Shepard. "Unilateral Centrifugation." Otology & Neurotology 32, no. 1 (January 2011): 116–21. http://dx.doi.org/10.1097/mao.0b013e3181ff7549.

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6

Knight, Pamela. "Continuous Centrifugation." Nature Biotechnology 6, no. 11 (November 1988): 1344–45. http://dx.doi.org/10.1038/nbt1188-1344.

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7

Kim, Mu-Young, and Hyun-Jung Han. "Optimization of a Two-Step Centrifugation Protocol for Bovine Platelet-Rich Plasma." Acta Veterinaria 72, no. 3 (September 1, 2022): 375–87. http://dx.doi.org/10.2478/acve-2022-0030.

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Abstract Platelet-rich plasma ( PRP), an autologous platelet concentrated in plasma, is a source of diverse growth factors and is extensively utilized to promote tissue healing. Most of the clinical and laboratory investigations in veterinary medicine have focused on horses and dogs. Consequently, the types and detailed conditions of the PRP preparation method are based on those species. However, in bovine medicine, only a few studies have investigated the species-specific characteristics of bovine platelets. The aim of this study was to optimize the conditions of a two-step centrifugation method for bovine PRP. Whole blood samples were obtained from eight healthy lactating Holstein-Friesian cows. Eight running conditions for the first and second centrifugations each were evaluated based on the platelet recovery rate, the concentration of growth factors, and the adenosine diphosphate (ADP)-induced aggregation response, which reflects the premature platelet activation caused by the centrifugation process. The results of this study showed that for the first and second centrifugations, 900×g for 10 minutes and 1250×g for 15 minutes, respectively, were the most suitable conditions for the platelet recovery rate, and the concentration of growth factors was highest under these conditions without significant activation of premature platelet aggregation. Thus, we established an optimal two-step centrifugation protocol for bovine PRP that should provide a better understanding of bovine platelets.

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8

Xu, Shujing, and Ali Nadim. "Oscillatory counter-centrifugation." Physics of Fluids 28, no. 2 (February 2016): 021302. http://dx.doi.org/10.1063/1.4939988.

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9

PITTS, JIM E. "Crystallization by centrifugation." Nature 355, no. 6356 (January 1992): 117. http://dx.doi.org/10.1038/355117a0.

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10

ABAD-ZAPATERO, CELE. "Crystallization by centrifugation." Nature 356, no. 6368 (April 1992): 392. http://dx.doi.org/10.1038/356392b0.

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11

PITTS, JIM E. "Crystallization by centrifugation." Nature 356, no. 6368 (April 1992): 392. http://dx.doi.org/10.1038/356392c0.

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12

Wood, EJ. "Basic centrifugation techniques." Biochemical Education 19, no. 3 (July 1991): 156–57. http://dx.doi.org/10.1016/0307-4412(91)90065-g.

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13

Miró, Jordi, and Marion Papas. "Improvement of cryopreservation protocol in both purebred horses including Spanish horses." Spanish Journal of Agricultural Research 16, no. 4 (January 8, 2019): e0406. http://dx.doi.org/10.5424/sjar/2018164-13677.

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There is a widely held belief that the semen of Purebred Spanish Horses (PRE) is of generally poorer quality than that of other breeds, and survives cryopreservation less well. To determine whether this is the case, sperm concentration, viability and morphological abnormalities were examined in a total 610 fresh ejaculates from 64 healthy PRE (N=47) and non-PRE stallions (N=17). Sperm concentration and viability were then re-examined after pre-freezing centrifugation, and once again after freezing-thawing. No differences were observed between the PRE and non-PRE stallions in terms of any sperm quality variable at any observation point. When considering all PRE and non-PRE samples together, differences in sperm viability were observed between fresh and fresh-centrifuged sperm viability (70.1±12.5% compared to 76.3±10.9%; p<0.01). After centrifugation the samples were also more homogeneous in terms of the total number of recovered sperm cells. Centrifugation also improved frozen-thawed sperm viability, reducing differences in sperm quality between individual stallions. For all centrifugations, a sperm:extender ratio of 1:5 was used. This would appear to provide better final results than those reported in the literature for the 1:1 ratio commonly used for PRE stallion sperm cryopreservation. In conclusion, obtained results show that the quality and frozen/thawed results of PRE stallion sperm are not lower than that of non-PRE breeds. In addition, using a 1:5 sperm:extender dilution ratio when selecting sperms by centrifugation prior to freezing, seems to provide better results than those usually reported when using a 1:1 ratio.

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14

Wiig, Helge, Knut Aukland, and Olav Tenstad. "Isolation of interstitial fluid from rat mammary tumors by a centrifugation method." American Journal of Physiology-Heart and Circulatory Physiology 284, no. 1 (January 1, 2003): H416—H424. http://dx.doi.org/10.1152/ajpheart.00327.2002.

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Access to interstitial fluid is of fundamental importance to understand tumor transcapillary fluid balance, including the distribution of probes and therapeutic agents. Tumors were induced by gavage of 9,10-dimethyl-1,2-benzanthracene to rats, and fluid was isolated after anesthesia by exposing tissue to consecutive centrifugations from 27 to 6,800 g. The observed51Cr-EDTA (extracellular tracer) tissue fluid-to-plasma ratio obtained from whole tumor or from superficial tumor tissue by centrifugation at 27–424 g was not significantly different from 1.0 (0.92–0.99), suggesting an extracellular origin only. However, fluid collected from excised central tumor parts had a significantly lower ratio (0.66–0.77) for all imposed G forces, suggesting dilution by fluid deriving from a space unavailable for51Cr-EDTA. The colloid osmotic pressure in tumor fluid was generally higher than in fluid isolated from the subcutis, attributable to less selective capillaries and impaired lymphatic drainage in tumors. HPLC analysis of tumor fluid showed that low-molecular-weight macromolecules not present in arterial plasma were present in tumor fluid obtained by centrifugation and in venous blood draining the tumor, most likely representing proteins derived from tumor cells. We conclude that low-speed centrifugation may be a simple and reliable method to isolate interstitial fluid from tumors.

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15

Peterson, Brandon W., Prashant K. Sharma, Henny C. van der Mei, and Henk J. Busscher. "Bacterial Cell Surface Damage Due to Centrifugal Compaction." Applied and Environmental Microbiology 78, no. 1 (October 28, 2011): 120–25. http://dx.doi.org/10.1128/aem.06780-11.

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ABSTRACTCentrifugal damage has been known to alter bacterial cell surface properties and interior structures, including DNA. Very few studies exist on bacterial damage caused by centrifugation because of the difficulty in relating centrifugation speed and container geometry to the damage caused. Here, we provide a simple, versatile method of analysis for describing the compaction of bacteria during centrifugation based on a proposed centrifugation coefficient,C. Values ofCcan be related to different bacterial cell surface properties. Changing the geometry of the centrifugation container or centrifugation speeds changed the value ofCsignificantly. Initial deposition rates ofStaphylococcus aureusATCC 12600 to a glass surface decayed exponentially from 4,217 to 1,478 cm−2s−1with increasingC, while the proportion of staphylococci with a zeta potential of around −15 mV decreased from 97 to 58%. These surface-sensitive parameters were used independently to derive a critical centrifugation coefficient (0.040), above which centrifugation was considered to impact the outcome of surface-sensitive experiments due to cell surface damage. The critical centrifugation coefficient could successfully predict staphylococcal cell surface damage, i.e., a significant change in initial deposition rate or zeta potential distribution, in 84% of all cases included here, whereas the centrifugation speed could predict damage in only 58% of all cases. Moreover, controlling the centrifugation coefficient within narrow limits over a series of experiments yielded 43% smaller standard deviations in initial staphylococcal deposition rates than with centrifugation at fixed speeds for replicate experiments.

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16

Jobs, Magnus, W. Mathias Howell, and Anthony J. Brookes. "Creating Arrays by Centrifugation." BioTechniques 32, no. 6 (June 2002): 1322–29. http://dx.doi.org/10.2144/02326mt03.

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17

Peters, Richard, and Robert S. Sikorski. "Centrifugation on the Web." Nature Biotechnology 14, no. 7 (July 1996): 899. http://dx.doi.org/10.1038/nbt0796-899a.

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18

SUZUKI, Yoshihisa, Tsutomu SAWADA, Atsushi MORI, and Katsuhiro TAMURA. "Colloidal Crystallization by Centrifugation." KOBUNSHI RONBUNSHU 64, no. 3 (2007): 161–65. http://dx.doi.org/10.1295/koron.64.161.

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19

Lakhtina, E. V. "Centrifugation of dilute ferrofluids." Physics Procedia 9 (2010): 221–23. http://dx.doi.org/10.1016/j.phpro.2010.11.049.

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20

Wood, EJ. "An Introduction to Centrifugation." Biochemical Education 19, no. 3 (July 1991): 157. http://dx.doi.org/10.1016/0307-4412(91)90066-h.

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21

Quinn, Paul. "An introduction to centrifugation." Trends in Cell Biology 1, no. 2-3 (August 1991): 76. http://dx.doi.org/10.1016/0962-8924(91)90097-s.

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22

S.E.H. "An introduction to centrifugation." Trends in Biochemical Sciences 16 (January 1991): 392. http://dx.doi.org/10.1016/0968-0004(91)90160-w.

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23

Ning, Li, Roberto Camassa, Robert E. Ecke, and Francesco Venneri. "Solutal Separation under Centrifugation." Separation Science and Technology 33, no. 4 (January 1998): 551–67. http://dx.doi.org/10.1080/01496399808544996.

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24

Schneider, Cornelia M., and Helmut Cölfen. "Analytical band centrifugation revisited." European Biophysics Journal 47, no. 7 (June 21, 2018): 799–807. http://dx.doi.org/10.1007/s00249-018-1315-1.

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25

Chan, Steven H., San Kiang, and Matthew A. Brown. "One-dimensional centrifugation model." AIChE Journal 49, no. 4 (April 2003): 925–38. http://dx.doi.org/10.1002/aic.690490411.

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26

Prell, M., R. E. Ellerbrock, J. Stewart, M. S. Bojko, and I. F. Canisso. "Comparison of centrifugation and non-centrifugation methods to cryopreserve stallion epidydimal semen." Journal of Equine Veterinary Science 43 (August 2016): S67. http://dx.doi.org/10.1016/j.jevs.2016.06.034.

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27

Molina, Miras Alejandro, Rosales Lorenzo López, García Maria del Carmen Cerón, Mirón Asterio Sánchez, Camacho Francisco Carcía, Gómez Antonio Contreras, and Grima Emilio Molina. "A new approach to finding optimal centrifugation conditions for shear-sensitive microalgae." Algal Research 44 (December 1, 2019): 101677. https://doi.org/10.1016/j.algal.2019.101677.

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A study has been conducted to assess clarification efficiency and cell damage during centrifugation, and to optimize this operation for the dinoflagellate microalga <em>Amphidinium carterae</em>. Although cells were easily recovered from the cell suspension, cell damage was observed in some experiments once the cells had sedimented. Cell damage depends on both the residence time of the cells in the pellet and on the g-force applied. 2D Computer fluid dynamics simulations were carried out to simulate and predict microalgal cell settling times, and a dimensionless number was used to obtain an operating window (combinations of g-force and centrifugation time) for optimal centrifugation of the microalga. The approach used in this study can be extrapolated to other cells and other centrifuges.

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28

Novia, Diana, and Binarwan Halim. "#302 : Shorter Centrifugation Time Leads to Better Sperm Quality in Swim-Up Processing Technique." Fertility & Reproduction 05, no. 04 (December 2023): 700. http://dx.doi.org/10.1142/s2661318223744120.

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Background and Aims: Centrifugation is one of the many factors that cause sperm DNA damage in IVF semen preparation. This can occur due to the formation of reactive oxygen species (ROS) that are uncontrollable, so that the quality of sperm DNA can be damaged. This study aims to compare sperm quality results with swim-up technique under centrifugation times of 5 and 10 minutes. Method: This study involved 50 patients at the Halim Fertility Center clinic from June 2020 to October 2020. The samples obtained were processed using the swim-up method. Samples were divided into 3 groups, namely control, 5 and 10 minutes of centrifugation. Sperm quality recorded was concentration, total motility, progressive motility and DNA fragmentation index (DFI). Results: The sperm concentration after 5- and 10-min centrifugation before swim-up (27.78-39.79 and 35.36–51.09, respectively; p [Formula: see text] 0.05) was significantly higher compared to control (24.85–32.33). The total motility before and after 5- and 10-min centrifugation were 43.78–51.08, 97.66–98.20, and 97.86–98.20, respectively. The progressive motility after 5- and 10-min centrifugation (0–41 and 0–54, respectively) was significantly higher than control (0–24; p < 0.05). The DFI was significantly better after 5 min centrifugation (3.82–6.98) compared to control and after 10 min centrifugation (13.48–19.04 and 1–25, respectively; p < 0.05). Conclusion: Shorter centrifugation times indicate lower progressive motility than long centrifugation times, but considering the lower DFI level, shorter centrifugation times must be used in sperm preparation for IVF to produce better sperm quality.

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29

Fallatah, Majed Hashem, Aaied Falah Al Otaibi, Randa Rajallah Aljohani, Waad Jamal Ghabban, and Alaa Ali Alshehri. "Evaluation of Centrifugation Technique and the Effect of Centrifugation Condition on the Laboratory Samples." JOURNAL OF HEALTHCARE SCIENCES 04, no. 12 (2024): 1003–9. https://doi.org/10.52533/johs.2024.41248.

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Centrifugation is a critical laboratory technique used to separate components within a mixture based on density differences. The efficiency and reliability of this process depend on the precise control of variables such as speed, time, temperature, and rotor design. Improper centrifugation settings can compromise sample integrity, leading to analytical inaccuracies. High-speed centrifugation, while effective for rapid separation, often imposes mechanical stress on samples, resulting in hemolysis or cellular damage. Time duration is equally significant, as insufficient centrifugation can cause incomplete separation, while prolonged exposure may induce thermal stress and biochemical degradation. Temperature control plays a pivotal role, particularly for temperature-sensitive biomolecules like enzymes, nucleic acids, and proteins. Unregulated temperatures during high-speed centrifugation can denature proteins and degrade nucleic acids, affecting their utility in downstream applications such as diagnostics and molecular biology. Automated centrifuges equipped with programmable cooling systems have proven effective in mitigating these risks. Centrifugation protocols require customization based on sample type. Blood, urine, and cellular samples exhibit distinct sensitivities to centrifugal force and duration, necessitating tailored approaches. Specialized techniques, such as density-gradient centrifugation, enhance separation precision for applications like exosome isolation. Recent innovations in centrifuge technology, including programmable speed ramps and advanced rotor designs, have significantly improved the reproducibility and reliability of centrifugation processes. Standardization of centrifugation protocols is essential to ensure consistency in laboratory results. Advances in centrifuge design and optimization strategies have enabled better preservation of sample integrity across diverse applications. These developments highlight the need for continuous refinement of protocols to accommodate emerging diagnostic and research requirements, ensuring high-quality outcomes in both clinical and experimental settings.

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30

Aukland, Knut, Olav Tenstad, and Helge Wiig. "Distribution spaces for hyaluronan and albumin in rat tail tendons." American Journal of Physiology-Heart and Circulatory Physiology 281, no. 4 (October 1, 2001): H1589—H1597. http://dx.doi.org/10.1152/ajpheart.2001.281.4.h1589.

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A low concentration of hyaluronan (HA) in lymph compared with tissue suggests a large bound fraction. To investigate the distribution and mobility of HA and serum albumin (Alb), we eluted the rat tail tendon with a series of l5 successive centrifugations, each preceded by the addition of 0.15 M NaCl (15% of initial wet wt). The eluate concentration fell exponentially versus the accumulated eluate, allowing estimation of the maximal elutable amount (EHA and EAlb). Alb elution was practically complete from a space of ≈28% of wet wt at all centrifugation rates. Twenty percent of HA was elutable at 500 rpm, apparently from the same space as Alb, increasing to 40% at >4,000 rpm. This pattern was not significantly influenced by using 2 M NaCl or by the addition of plasma or metabolic inhibitors. Without prehydration and centrifugation at high revolutions per minute, both Alb and HA concentrations fell rapidly toward zero, presumably in part reflecting mobilization of HA- and Alb-free fluid from the collagen intrafibrillar space (3). We conclude that with prehydration the fibrils swell, increasing the intramolecular spaces to become “penetrable” to HA and allowing removal of HA-containing fluid when the fibrils are compressed by the next centrifugation at high revolutions per minute, increasing EHA from 23 to 45%. Chemical binding presumably explains the unelutable 55% of tendon HA. Intrafibrillar HA may act to stabilize the fibrillar volume.

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31

Kim, Y. G., S. Bech-Nielsen, J. C. Gordon, R. D. Slemons, and E. Spangler. "Comparison of two methods for isolation of Mycobacterium paratuberculosis from bovine fecal samples." American Journal of Veterinary Research 50, no. 7 (July 1, 1989): 1110–13. https://doi.org/10.2460/ajvr.1989.50.07.1110.

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SUMMARY Fecal samples from 131 cattle clinically suspect for paratuberculosis were cultured bacteriologically, using the traditional sedimentation processing method and a processing method that included a centrifugation step. Of 16 samples that were contaminated, 6 were culture-positive on at least 1 medium and by 1 processing method. Ten of 131 (7.6%) fecal samples processed by both methods were lost because of contamination. The number of culture-positive samples (using both processing methods) were 65 of 121 (53.7%) on media without miconazole and 60 of 121 (49.6%) on media with miconazole. Seven of the 121 (5.8%) samples were culture-positive, using centrifugation, after 16 weeks’ incubation at 37 C. Thirteen of 60 (21.7%) isolates were obtained only with centrifugation, and 10 of these had low colony counts, suggesting that a centrifugation step may have concentrated microorganisms that would have gone undetected without centrifugation. Six of 60 (10%) isolates positive for M paratuberculosis on the sedimentation method were negative on the centrifugation method. Contamination rates were significantly (P < 0.001) increased when centrifugation was used. The miconazole significantly (P < 0.001) decreased contamination rates when centrifugation was used.

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32

Luschei, Edward C., Douglas D. Buhler, and Jack H. Dekker. "Effect of separating giant foxtail (Setaria faberi) seeds from soil using potassium carbonate and centrifugation on viability and germination." Weed Science 46, no. 5 (October 1998): 545–48. http://dx.doi.org/10.1017/s0043174500091074.

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Changes in weed seedbank composition are often monitored by removing seeds from soil samples. One extraction method accomplishes this by creating a slurry of soil and a concentrated inorganic salt solution. Centrifugation is then used to separate constituents of differing densities. We have found that centrifugation of giant foxtail seeds in 3.2 M potassium carbonate solution as conducted in a centrifugation/flotation extraction method can reduce viability as measured by germination and tetrazolium tests. In one experiment, centrifugation/flotation separation reduced germination of giant foxtail seeds from 94 to 52%. The likely cause of seed damage was the high pH of the potassium carbonate solution in conjunction with the increased hydrostatic pressure due to centrifugation. While centrifugation affected quantitative measures of seed viability, it did not alter qualitative viability estimates using a pressure test.

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33

Miró, Jordi, and Ester Taberner. "Effect of short-term conservation temperature, with or without centrifugation, on the survival and motility of Catalonian donkey spermatozoa." Spanish Journal of Agricultural Research 18, no. 1 (April 22, 2020): e0402. http://dx.doi.org/10.5424/sjar/2020181-15740.

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Aim of study: To analyze the effect of three short-term storage temperatures with or without removing seminal plasma on the survival and motility of donkey sperm and the response to refrigeration and centrifugation of the different spermatozoa subpopulations.Area of study: North-eastern Spain (Catalonia).Material and methods: Semen from seven Catalonian jackasses was diluted with a skimmed milk-based (Kenney) extender and different treatments were obtained: FRESH semen, FRESH semen immediately centrifuged to remove the seminal plasma before resuspension in Kenney extender (FRESH+CENTRIFUGATION), FRESH semen stored at 5/15/20ºC for 2 h (STORAGE 5/15/20ºC), and STORAGE 5/15/20ºC semen then centrifuged (STORAGE 5/15/20ºC+CENTRIFUGATION). Survival was examined using eosin-nigrosin stained smears. Motion was assessed by means of a computer-assisted sperm analyzer (CASA).Main results: The spermatozoa of the STORAGE 5ºC and 20ºC showed an overall motility similar to that seen in FRESH samples. However, the STORAGE 15ºC led to an important motility reduction. No differences were seen between the FRESH and STORAGE 5/15/20ºC with respect to progressive motility. However, STORAGE 5/15/20ºC+CENTRIFUGATION all reduced total motility, and STORAGE 15ºC+CENTRIFUGATION led to reduced survival. The sperm motile subpopulations structure of donkey semen was maintained after STORAGE 5/15/20ºC+CENTRIFUGATION, although STORAGE 15ºC+CENTRIFUGATION led to important changes. STORAGE 5/20ºC+CENTRIFUGATION, in contrast, only induced slight changes. STORAGE 20ºC+CENTRIFUGATION was associated with no change in the percentage of sperm cells belonging to each Subpopulation compared to FRESH sperm.Research highlights 2 h of storage at 20ºC followed by centrifugation is suitable for the short-term storage of donkey semen.

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34

Majid, Nurcholis. "PENGARUH VARIASI WAKTU SENTRIFUGASI NILAI HEMATOKRIT MENGGUNAKAN METODE MIKROHEMATOKRIT DI UNIVERSITAS BINAWAN." Jurnal SainHealth 7, no. 2 (September 28, 2023): 51. http://dx.doi.org/10.51804/jsh.v7i2.14334.51-57.

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Hematocrit is the total volume of red blood cells in 100 ml of blood expressed as a percentage of blood volume. Hematocrit examination is needed to help diagnose diseases such as anemia and dengue hemorrhagic fever (DHF) to determine the total volume of red blood cells or erythrocytes. The normal value for hematocrit examination is 40-54% for males and 37-47% for females. The purpose of this study was to determine the effect of variations in centrifugation time on hematocrit values using the microhematocrit method. This type of research is quantitative using experimental method with cross sectional design. The method used for hematocrit examination is the microhematocrit method with variations in centrifugation time of 2 minutes, 3 minutes, 4 minutes, and 5 minutes as a control with a speed of 12,000 rpm. The respondents of this study were 35 respondents and the samples of this study were 35 venous blood samples taken from Binawan University students, Medical Laboratory Technology Study Program batch 2021 and 2022. The average result of the 2-minute centrifugation hematocrit value examination is 37.87%, 3-minute centrifugation is 37.57%, 4-minute centrifugation is 37.30%, and 5-minute centrifugation is 37.25%. The Wilcoxon test results show the Sig. (2-tailed) of 2-minute centrifugation compared with 5 minutes is 0.00 (<0.05), 3-minute centrifugation compared with 5 minutes is 0.001 (<0.05), 4-minute centrifugation compared with 5 minutes is 0.560 (>0.05). The results of this study showed that hematocrit values with centrifugation times of 2 minutes and 3 minutes compared to 5 minutes had significant differences in hematocrit values.

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Maharani, Eva Ayu, and Dewi Astuti. "Comparison of Single Centrifugation, Double Centrifugation and Turn down-Turn up Techniques for Platelet-Rich Plasma Quality." Althea Medical Journal 9, no. 3 (September 30, 2022): 180–84. http://dx.doi.org/10.15850/amj.v9n3.2628.

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Background: Platelet-rich plasma (PRP) is a new concept used in medical world, especially for wound healing. The main process that affects the PRP quality is the centrifugation process. This study aimed to assess the PRP separation process and determine the best technique of various centrifugation process.Methods: This experimental study used acid citrate dextrose (ACD) blood taken from 11 healthy respondents and compared three-techniques including the single centrifugation (SC), the double centrifugation (DC), and the double centrifugation turn down - turn up (DC-TDTU) techniques. The quality of PRP was measured based on blood cells count (platelet, leukocyte, erythrocyte count, and Ht value) at each stage of centrifugation. The examination was carried out in 2021 at the Hematology Laboratory, Poltekkes Jakarta 3.Results: The mean values of platelets, leukocytes, and Ht were increased in PRP compared to plasma supernatant both using the DC and DC-TDTU techniques, wherase the SC technique decreased in plasma compared with whole blood. When the procedures using DC and DC-TDTU are carried out properly, platelets would be concentrated in the second centrifugation. However, some erythrocyte and leukocyte contamination occurred by DC-TDTU technique compared to the DC technique.Conclusion: The double centrifugation technique is the best Platelet-rich plasma separation technique compared to the DC-TDTU and SC techniques.

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36

Lebl, Michal. "Centrifugation Based Automated Synthesis Technologies." JALA: Journal of the Association for Laboratory Automation 8, no. 3 (June 2003): 30–35. http://dx.doi.org/10.1016/s1535-5535-04-00267-9.

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Centrifugation is a powerful method for solid-liquid separation. It can be applied in numerous ways to simplify solid phase synthetic procedures. At the same time, centrifugation is the only totally parallel technique which can be scaled up for processing volume or number of simultaneously run reactions, without the limitation of overpressure or vacuum-driven filtration-based systems. We have developed synthesizers based on the power of centrifugation — peptide and small organic molecule synthesizers utilizing cotton as the synthetic substrate and inclusion volume chemistry, synthesizers for automation of “tea bag” synthesis, and synthesizers based on “tilted plate centrifugation”. The last technique was employed in an oligonucleotide production facility with the capacity of more than 10 million compounds per year.

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37

Xu, Xufeng, and Helmut Cölfen. "Ultracentrifugation Techniques for the Ordering of Nanoparticles." Nanomaterials 11, no. 2 (January 27, 2021): 333. http://dx.doi.org/10.3390/nano11020333.

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A centrifugal field can provide an external force for the ordering of nanoparticles. Especially with the knowledge from in-situ characterization by analytical (ultra)centrifugation, nanoparticle ordering can be rationally realized in preparative (ultra)centrifugation. This review summarizes the work back to the 1990s, where intuitive use of centrifugation was achieved for the fabrication of colloidal crystals to the very recent work where analytical (ultra)centrifugation is employed to tailor-make concentration gradients for advanced materials. This review is divided into three main parts. In the introduction part, the history of ordering microbeads in gravity is discussed and with the size of particles reduced to nanometers, a centrifugal field is necessary. In the next part, the research on the ordering of nanoparticles in analytical and preparative centrifugation in recent decades is described. In the last part, the applications of the functional materials, fabricated from centrifugation-induced nanoparticle superstructures are briefly discussed.

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38

Noguchi, Michiko, Koji Yoshioka, Hirokazu Hikono, Gentaro Iwagami, Chie Suzuki, and Kazuhiro Kikuchi. "Centrifugation on Percoll density gradient enhances motility, membrane integrity and in vitro fertilizing ability of frozen–thawed boar sperm." Zygote 23, no. 1 (May 9, 2013): 68–75. http://dx.doi.org/10.1017/s0967199413000208.

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SummaryThe effects of Percoll density gradient centrifugation on sperm quality, in vitro fertilizability and developmental capacity of frozen–thawed boar sperm were evaluated. Two-step density gradient centrifugation by Percoll enhanced significantly the motility parameters of sperm compared with a simple centrifugation procedure. Percentages of motile sperm and sperm with intact plasma and acrosome membranes after Percoll separation were significantly greater than those after simple centrifugation. The rates of penetration, cleavage and blastocyst formation after in vitro fertilization were significantly improved by Percoll separation compared with simple centrifugation and were influenced positively by the intactness of sperm head membranes, but not any sperm motility parameters. However, insemination with increased concentrations of sperm prepared by Percoll gradient centrifugation did not improve the success of fertilization and embryo development in vitro. Our results indicate that the integrity of sperm head membranes after Percoll separation is important for successful embryo development in vitro, more so than sperm motility.

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39

Bos, Jelte E., and Bruno J. Correia Grácio. "Perceived radial translation during centrifugation." Journal of Vestibular Research 25, no. 3,4 (October 15, 2015): 119–24. http://dx.doi.org/10.3233/ves-150555.

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40

Hodgson, John. "Centrifugation Takes a New Turn." Nature Biotechnology 9, no. 7 (July 1991): 628–29. http://dx.doi.org/10.1038/nbt0791-628.

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41

Agostini, Tommaso, Giuseppe Spinelli, Raffella Perello, Daniele Bani, and Giulia Boccalini. "Analysis of Lipoasiprated Following Centrifugation." Journal of Craniofacial Surgery 27, no. 6 (September 2016): 1489–93. http://dx.doi.org/10.1097/scs.0000000000002834.

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42

Mostowfi, Farshid, Kentaro Indo, Oliver C. Mullins, and Richard McFarlane. "Asphaltene Nanoaggregates Studied by Centrifugation†." Energy & Fuels 23, no. 3 (March 19, 2009): 1194–200. http://dx.doi.org/10.1021/ef8006273.

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43

Lee, James C. "Review of Rickwood, Preparative Centrifugation." Biophysical Journal 67, no. 6 (December 1994): 2558. http://dx.doi.org/10.1016/s0006-3495(94)80745-3.

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44

Chewter, Les, and Michael Golombok. "Convective Flow during Gas Centrifugation." Industrial & Engineering Chemistry Research 43, no. 20 (September 2004): 6626–28. http://dx.doi.org/10.1021/ie049628z.

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45

Lebl, M. "Centrifugation Based Automated Synthesis Technologies." Journal of the Association for Laboratory Automation 8, no. 3 (June 1, 2003): 30–35. http://dx.doi.org/10.1016/s1535-5535(04)00267-9.

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46

Anand, CV. "Preparative centrifugation: A practical approach." Biochemical Education 22, no. 3 (July 1994): 165. http://dx.doi.org/10.1016/0307-4412(94)90061-2.

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47

Roberts, W. L. "Gas centrifugation of research isotopes." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 282, no. 1 (October 1989): 271–76. http://dx.doi.org/10.1016/0168-9002(89)90151-4.

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48

Quinn, Paul. "Preparative centrifugation: A practical approach." Trends in Cell Biology 3, no. 8 (August 1993): 285. http://dx.doi.org/10.1016/0962-8924(93)90063-7.

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49

Celorie, Jay A., Ted S. Vinson, Sandra L. Woods, and Jonathan D. Istok. "Modeling Solute Transport by Centrifugation." Journal of Environmental Engineering 115, no. 3 (June 1989): 513–26. http://dx.doi.org/10.1061/(asce)0733-9372(1989)115:3(513).

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50

Morrell, JM, and M. Wallgren. "Colloid Centrifugation of Boar Semen." Reproduction in Domestic Animals 46 (August 26, 2011): 18–22. http://dx.doi.org/10.1111/j.1439-0531.2011.01866.x.

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