Journal articles: 'Hansea (Bonn)'

1

Bender, Hanno. "Kartellamt stärkt Online-Handel." Lebensmittel Zeitung 73, no. 15 (2021): 24. http://dx.doi.org/10.51202/0947-7527-2021-15-024-6.

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Bender, Hanno. "Handel handelt überwiegend fair." Lebensmittel Zeitung 73, no. 2 (2021): 1. http://dx.doi.org/10.51202/0947-7527-2021-2-001-6.

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Kasai, Norio. "Maxillary bone deformation in patients with leprosy: a novel method for quantitative evaluation by CT scan." JAPANESE JOURNAL OF LEPROSY 88, no. 2 (2019): 43–49. http://dx.doi.org/10.5025/hansen.88.43.

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Lenders, Dirk. "Nienhoff soll Konflikte lösen." Lebensmittel Zeitung 73, no. 9 (2021): 20. http://dx.doi.org/10.51202/0947-7527-2021-9-020-4.

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Bonn/Berlin. Nach seinem Ausscheiden als QS-Geschäftsführer übernimmt Hermann-Josef Nienhoff die Leitung der neuen „Koordinationszentrale Handel Landwirtschaft“. Mögliche neue Aufgaben sieht er auch für das QS-System, das in diesem Jahr seinen 20. Geburtstag feiert.

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Wang, Ke-Rang, Dan Han, Guo-Jing Cao, and Xiao-Liu Li. "Link spacer controlled supramolecular chirality of perylene bisimide-carbohydrate conjugate." RSC Advances 5, no. 59 (2015): 47728–31. http://dx.doi.org/10.1039/c5ra06255a.

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Controllable supramolecular chirality based on the self-assembly of the perylene bisimide-carbohydrate conjugates was achieved, exhibiting right-handed chirality with triazole as linker and left-handed chirality with the amide bond as linker.

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Wang, Ruimin, Daniel Hartnick, and Ulli Englert. "Short is strong: experimental electron density in a very short N···I halogen bond." Zeitschrift für Kristallographie - Crystalline Materials 233, no. 9-10 (September 25, 2018): 733–44. http://dx.doi.org/10.1515/zkri-2018-2069.

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Abstract 2,3,5,6-Tetrafluoro-1,4-diiodobenzene and 4-(dimethylamino)pyridine co-crystallize in 1:2 stoichiometry. A diffraction experiment at standard resolution was already conducted in 2010 and revealed one of the shortest N···I contacts ever reported. We collected X-ray intensities at 100 K up to a very high resolution of 1.23 Å−1. These experimental data allowed to refine a structure model based on atom-centered multipoles according to the Hansen-Coppens approach and provided an experimental electron density. A subsequent analysis with the help of Bader’s atoms in molecules theory showed a strong interaction between the pyridine N atom and the σ hole of its closest iodine neighbor on the halogenated benzene. This contact is characterized by a distance of 2.6622(4) Å and associated with a remarkably large electron density of 0.359(5) e⋅Å−3 in the (3, −1) critical point, unprecedented for a secondary interaction. This bona fide shortest halogen bond ever investigated by an experimental charge density study is associated with a significantly negative total energy density in the bond critical point and thus can reliably be classified as strong. Both the electron density and the position of the bond critical point suggest to compare the short N···I contact to coordinative or covalent bonds rather than to σ hole interactions.

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Yeston, Jake. "Left- or right-handed C–H bond activation." Science 359, no. 6377 (February 15, 2018): 756.10–758. http://dx.doi.org/10.1126/science.359.6377.756-j.

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Rasmussen, Stig T., John Lind, Jesper Jakobsen, and Robert Bohn. "Anmeldelser." Fund og Forskning i Det Kongelige Biblioteks Samlinger 53 (March 3, 2014): 429. http://dx.doi.org/10.7146/fof.v53i0.118868.

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Stig T. Rasmussen anmelder: Tusind og én Nat. Udg. af Ellen Wulff & Kim Witthoff. 2013John Lind anmelder: Den Ryssiske Lov 1649. Oversat og kommenteret af Rasmus Æreboe 1721. Udg. af Lars P. Poulsen-Hansen. 2013Jesper Jakobsen anmelder: Raymond Birn: Royal Censorship of Books in Eighteenth–Century France. 2012Robert Bohn: John T. Lauridsen (udg.): Werner Bests korrespondance med Auswärtiges Amt og andre tyske akter vedrørende besættelsen af Danmark 1942-1945. 2012

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A, David Stephen, Asthana S.N, Rajesh. B. Pawar, and Kumuradhas P. "Charge density studies of energetic material: RDX." Frontiers in Advanced Materials Research 2, no. 1 (May 26, 2020): 1–14. http://dx.doi.org/10.34256/famr2011.

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Experimental charge density study has been carried out for Cyclotrimethylene-trinitramine (space group Pbca), an explosive material from a low temperature X-ray diffraction experiment. The electron density was modeled using the Hansen-Coppens multipole model and refined to R=0.032 for 6226 unique observed reflections. The electron density, laplacian and electrostatic potential distributions are reported and discussed, especially, the properties of the bond (3,-1) critical points, which are thought to play a key role in the decomposition of the molecule. From the bond topological analysis of all the bonds, it is observed that the N–N bond is the weakest. The dominating nature of the oxygen atoms was clearly well understood from isosurface electrostatic potential of isolated and symmetrically sitting molecules in the crystal.

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10

Brems, Hans. "The Origins of Keynesian Fiscal Activism." Journal of the History of Economic Thought 16, no. 1 (1994): 27–39. http://dx.doi.org/10.1017/s1053837200001401.

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The first part of the paper, “The Freeze,” restates the simplified Keynesian framework of fiscal activism pioneered by Jargen Pedersen (1937) and Alvin H. Hansen (1941). The framework is a macroeconomic model in which investment, the bond supply, price, the money wage rate, and the rate of interest are all frozen. Using government purchase and the tax rate as its policy instruments the paper solves the model and finds its fiscal multipliers.

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Suganthi, R. V., E. K. Girija, S. Narayana Kalkura, H. K. Varma, and A. Rajaram. "Self-assembled right handed helical ribbons of the bone mineral hydroxyapatite." Journal of Materials Science: Materials in Medicine 20, S1 (June 21, 2008): 131–36. http://dx.doi.org/10.1007/s10856-008-3495-1.

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12

Mackay, Frances. "The Effect of Adhesive Type and Thickness on Bond Strength of Orthodontic Brackets." British Journal of Orthodontics 19, no. 1 (February 1992): 35–39. http://dx.doi.org/10.1179/bjo.19.1.35.

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Fine-mesh hased brackets were handed to plastic cylinders using four different adhesives. Adhesive thickness was controlled using a bonding jig. The bond was then tested to failure using a shear force. Each adhesive had its own minimum thickness, probably related to its viscosity. Increasing the thickness of the adhesives to 0·26 mm, using a stainless steel spacer had minimal effect on their mean shear bond strength.

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Petrou, Ilias, Claire Savioz-Leissing, and Anne Gray. "Traumatic Dislocation of the Pisiform Bone." Journal of Hand and Microsurgery 10, no. 01 (September 7, 2017): 037–40. http://dx.doi.org/10.1055/s-0037-1606206.

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AbstractPisiform dislocation is a rare wrist injury. The limited literature available describes this pathology in the form of case reports. An immediate closed reduction and immobilization is indicated for acute injury while there is a debate in the management of cases with delayed diagnosis or failed closed reduction. In this case, a 32-year-old, right-handed man visited the emergency department with pain at the ulnar side of his left wrist after a fall. The initial management involved immobilization, and the patient was referred to the authors’ specialized clinic 10 days later because of persistence of important ulnar wrist pain. The choice of treatment was pisiform excision without ligament reconstruction with excellent functional results.

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Kang, Young Kee, and Joo Yun Lee. "Helix foldamers of γ-peptides based on 2-aminocyclopentylacetic acid." New Journal of Chemistry 39, no. 5 (2015): 3241–49. http://dx.doi.org/10.1039/c4nj01202j.

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Oligo-γ-peptides based on 2-aminocyclopentylacetic acid (γAc₅a) with a cyclopentyl constraint on the C^β–C^γ bond and homochiral (1S,2S) configurations preferentially adopt the right-handed 14-helix foldamers in the gas phase and in solution.

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15

Gessmann, Renate, Hans Brückner, and Kyriacos Petratos. "The first N-terminal unprotected (Gly-Aib)npeptide: H-Gly-Aib-Gly-Aib-OtBu." Acta Crystallographica Section C Structural Chemistry 71, no. 12 (November 28, 2015): 1114–17. http://dx.doi.org/10.1107/s2053229615022597.

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Glycine (Gly) is incorporated in roughly half of all known peptaibiotic (nonribosomally biosynthesized antibiotic peptides of fungal origin) sequences and is the residue with the greatest conformational flexibility. The conformational space of Aib (α-aminoisobutyric acid) is severely restricted by the second methyl group attached to the Cαatom. Most of the crystal structures containing Aib are N-terminal protected. Deprotection of the N- or C-terminus of peptides may alter the hydrogen-bonding scheme and/or the structure and may facilitate crystallization. The structure reported here for glycyl-α-aminoisobutyrylglycyl-α-aminoisobutyric acidtert-butyl ester, C16H30N4O5, describes the first N-terminal-unprotected (Gly-Aib)npeptide. The achiral peptide could form an intramolecular hydrogen bond between the C=O group of Gly1 and the N—H group of Aib4. This hydrogen bond is found in all tetrapeptides and N-terminal-protected tripeptides containing Aib, apart from one exception. In the present work, this hydrogen bond is not observed (N...O = 5.88 Å). Instead, every molecule is hydrogen bonded to six other symmetry-related molecules with a total of eight hydrogen bonds per molecule. The backbone conformation starts in the right-handed helical region (and the left-handed helical region for the inverted molecule) and reverses the screw sense in the last two residues.

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16

Zhao, S., M. Arnold, S. Ma, R. L. Abel, J. P. Cobb, U. Hansen, and O. Boughton. "Standardizing compression testing for measuring the stiffness of human bone." Bone & Joint Research 7, no. 8 (August 2018): 524–38. http://dx.doi.org/10.1302/2046-3758.78.bjr-2018-0025.r1.

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Objectives The ability to determine human bone stiffness is of clinical relevance in many fields, including bone quality assessment and orthopaedic prosthesis design. Stiffness can be measured using compression testing, an experimental technique commonly used to test bone specimens in vitro. This systematic review aims to determine how best to perform compression testing of human bone. Methods A keyword search of all English language articles up until December 2017 of compression testing of bone was undertaken in Medline, Embase, PubMed, and Scopus databases. Studies using bulk tissue, animal tissue, whole bone, or testing techniques other than compression testing were excluded. Results A total of 4712 abstracts were retrieved, with 177 papers included in the analysis; 20 studies directly analyzed the compression testing technique to improve the accuracy of testing. Several influencing factors should be considered when testing bone samples in compression. These include the method of data analysis, specimen storage, specimen preparation, testing configuration, and loading protocol. Conclusion Compression testing is a widely used technique for measuring the stiffness of bone but there is a great deal of inter-study variation in experimental techniques across the literature. Based on best evidence from the literature, suggestions for bone compression testing are made in this review, although further studies are needed to establish standardized bone testing techniques in order to increase the comparability and reliability of bone stiffness studies. Cite this article: S. Zhao, M. Arnold, S. Ma, R. L. Abel, J. P. Cobb, U. Hansen, O. Boughton. Standardizing compression testing for measuring the stiffness of human bone. Bone Joint Res 2018;7:524–538. DOI: 10.1302/2046-3758.78.BJR-2018-0025.R1.

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17

Saliba, Issam, Marc-Elie Nader, Fouad El Fata, and Tony Leroux. "Bone anchored hearing aid in single sided deafness: Outcome in right-handed patients." Auris Nasus Larynx 38, no. 5 (October 2011): 570–76. http://dx.doi.org/10.1016/j.anl.2011.01.008.

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18

Gräfenstein, Jürgen. "The Structure of the “Vibration Hole” around an Isotopic Substitution—Implications for the Calculation of Nuclear Magnetic Resonance (NMR) Isotopic Shifts." Molecules 25, no. 12 (June 24, 2020): 2915. http://dx.doi.org/10.3390/molecules25122915.

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Calculations of nuclear magnetic resonance (NMR) isotopic shifts often rest on the unverified assumption that the “vibration hole”, that is, the change of the vibration motif upon an isotopic substitution, is strongly localized around the substitution site. Using our recently developed difference-dedicated (DD) second-order vibrational perturbation theory (VPT2) method, we test this assumption for a variety of molecules. The vibration hole turns out to be well localized in many cases but not in the interesting case where the H/D substitution site is involved in an intra-molecular hydrogen bond. For a series of salicylaldehyde derivatives recently studied by Hansen and co-workers (Molecules 2019, 24, 4533), the vibrational hole was found to stretch over the whole hydrogen-bond moiety, including the bonds to the neighbouring C atoms, and to be sensitive to substituent effects. We discuss consequences of this finding for the accurate calculation of NMR isotopic shifts and point out directions for the further improvement of our DD-VPT2 method.

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Bacsa, John, Maurice Okello, Pankaj Singh, and Vasu Nair. "Solid-state tautomeric structure and invariom refinement of a novel and potent HIV integrase inhibitor." Acta Crystallographica Section C Crystal Structure Communications 69, no. 3 (February 14, 2013): 285–88. http://dx.doi.org/10.1107/s0108270113003806.

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The conformation and tautomeric structure of (Z)-4-[5-(2,6-difluorobenzyl)-1-(2-fluorobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]-4-hydroxy-2-oxo-N-(2-oxopyrrolidin-1-yl)but-3-enamide, C27H22F3N3O5, in the solid state has been resolved by single-crystal X-ray crystallography. The electron distribution in the molecule was evaluated by refinements with invarioms, aspherical scattering factors by the method of Dittrichet al.[Acta Cryst.(2005), A61, 314–320] that are based on the Hansen–Coppens multipole model [Hansen & Coppens (1978).Acta Cryst.A34, 909–921]. The β-diketo portion of the molecule exists in the enol form. The enol –OH hydrogen forms a strong asymmetric hydrogen bond with the carbonyl O atom on the β-C atom of the chain. Weak intramolecular hydrogen bonds exist between the weakly acidic α-CH hydrogen of the keto–enol group and the pyridinone carbonyl O atom, and also between the hydrazine N—H group and the carbonyl group in the β-position from the hydrazine N—H group. The electrostatic properties of the molecule were derived from the molecular charge density. The molecule is in a lengthened conformation and the rings of the two benzyl groups are nearly orthogonal. Results from a high-field1H and13C NMR correlation spectroscopy study confirm that the same tautomer exists in solution as in the solid state.

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20

Wiegandt, Claus-C., Sabine Baumgart, Nina Hangebruch, Linus Holtermann, Christian Krajewski, Matthias Mensing, Cordula Neiberger, et al. "Determinanten des Online-Einkaufs – eine empirische Studie in sechs nordrhein-westfälischen Stadtregionen." Raumforschung und Raumordnung 76, no. 3 (June 30, 2018): 247–65. http://dx.doi.org/10.1007/s13147-018-0532-5.

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Zusammenfassung Einzelhandel findet heute nicht nur in den Stadt- und Stadtteilzentren bzw. in den Einkaufszentren am Rande der Städte statt, sondern zunehmend auch im Internet. Der Beitrag untersucht, welche Determinanten ausschlaggebend sind, im stationären Einzelhandel bzw. im Online-Handel einzukaufen. Die Ergebnisse basieren auf einer Befragung von rund 2.900 Personen in den sechs nordrhein-westfälischen Stadtregionen Aachen, Bochum, Bonn, Dortmund, Münster und Köln. In Abhängigkeit der Entfernung zur jeweiligen Innenstadt wurde in insgesamt 26 Untersuchungsgebieten befragt. In allen sechs Stadtregionen zeigt sich, dass nicht die räumlichen, sondern ausgewählte demographische und sozioökonomische Faktoren das Einkaufsverhalten bestimmen. Das Geschlecht, das Alter und die Lebensstile spielen beim Online-Einkauf eine wesentliche Rolle, das Einkommen ist keine beeinflussende Größe.

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Hu, Yi, Dongmei Guo, Ying Deng, and Shouyang Wang. "Estimation of Nonlinear Dynamic Panel Data Models with Individual Effects." Mathematical Problems in Engineering 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/672610.

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This paper suggests a generalized method of moments (GMM) based estimation for dynamic panel data models with individual specific fixed effects and threshold effects simultaneously. We extend Hansen’s (Hansen, 1999) original setup to models including endogenous regressors, specifically, lagged dependent variables. To address the problem of endogeneity of these nonlinear dynamic panel data models, we prove that the orthogonality conditions proposed by Arellano and Bond (1991) are valid. The threshold and slope parameters are estimated by GMM, and asymptotic distribution of the slope parameters is derived. Finite sample performance of the estimation is investigated through Monte Carlo simulations. It shows that the threshold and slope parameter can be estimated accurately and also the finite sample distribution of slope parameters is well approximated by the asymptotic distribution.

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Barker, Clive. "Hansel Ndumbe Eyoh ed. Beyond the Theatre German Foundation for International Development (Hans-Boeckler-Strasse 5, D-5300 Bonn 3), 1991. 206 p." New Theatre Quarterly 9, no. 35 (August 1993): 303. http://dx.doi.org/10.1017/s0266464x00008150.

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23

Game, Aaron, and Jason Wu. "A Covariate Residual-Based Cointegration Test Applied to the CDS-Bond Basis." Journal of Time Series Econometrics 5, no. 2 (April 26, 2013): 163–92. http://dx.doi.org/10.1515/jtse-2012-0020.

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AbstractThis paper proposes a residual-based cointegration test with improved power. Based on the idea of Hansen (1995) and Elliot and Jansson (2003) in the unit root testing case, stationary covariates are used to improve the power of the residual-based augmented Dickey–Fuller (ADF) test. The asymptotic null distribution contains difficulty to estimate nuisance parameters for which there is no obvious method of estimation; therefore, we propose a bootstrap methodology to obtain test critical values. Local-to-unity asymptotics and Monte Carlo simulations are used to evaluate the power of the test in large and small samples, respectively. These exercises show that the addition of covariates increases power relative to the ADF and Johansen tests, and that the power depends on the long-run correlation between the covariates and the cointegration candidates. The new test is used to test for cointegration between Credit Default Swap (CDS) and corporate bond spreads for a panel of US firms during the 2007–2009 financial crisis. The new test finds stronger evidence for cointegration between the two spreads for more firms, relative to ADF and Johansen tests.

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TROPET, Y., J. M. BRIENTINI, P. GARBUIO, P. E. RIDOUX, and P. VICHARD. "Reconstruction of a Complex Defect of the Dorsum of the Hand." Journal of Hand Surgery 20, no. 5 (October 1995): 591–95. http://dx.doi.org/10.1016/s0266-7681(05)80116-0.

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A 37-year-old right-handed male truck driver was admitted with a severe injury of the dorsum of his right hand following a traffic accident. He had a large combined defect involving skin, tendons and bone. A complex reconstruction was performed using a large iliac crest allograft, a tendon graft and a free serratus anterior flap in one stage, 8 hours after the injury. A skin graft was performed later. 2 years later the functional and aesthetic result are good.

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Nurcahyanti, Tri Meida, Tatik Widiharih, and Budi Warsito. "PEMODELAN B-SPLINE UNTUK MENGESTIMASI KURVA YIELD OBLIGASI PEMERINTAH KODE FIXED RATE." Jurnal Gaussian 8, no. 2 (May 30, 2019): 244–52. http://dx.doi.org/10.14710/j.gauss.v8i2.26669.

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Bond is a medium-long term loan agreement that can be handed over, it contains a promise from the issuer to pay rewards in the form of interest on a particular period and paying off the principal debt on the time that has been appointed to the bond buyer. A method to find out the relationship between yield and time to maturity for a type of bond at any given time is illustrated through the yield curve. One of the methods for estimating yield curve is B-spline. The data that used to estimate the yield curve with B-spline model are sourced from Indonesia Stock Exchange, namely Government Bond Trading Report with code FR (Fixed Rate). The data periods used are 9, 16, and 23 November 2018. The best model for estimating the yield curve at any period of the data is linear B-spline model with 6 knots but the knot position is different for every data period. Based on the calculation of MAPE, the ability of the model to predict is very good. Investment with maximum profit based on the estimation of yield curve using B-spline linear model with 6 knot is FR0071.Keywords: bond, yield, yield curve, Government Bond, B-spline

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Palombit, Ryne A. "Pair Bonds in Monogamous Apes: a Comparison of the Siamang Hylobates Syndactylus and the White-Handed Gibbon Hylobates Lar." Behaviour 133, no. 5-6 (1996): 321–56. http://dx.doi.org/10.1163/156853996x00486.

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AbstractDescriptions of the social systems of gibbons (Hylobates, Hylobatidae) have typically emphasized generically uniform attributes such as 'monogamy' and 'territoriality'. This has prevented testing of the hypothesis that pair bonds differ in the siamang (Hylobates syndactylus) and the white-handed gibbon (Hylobates lar) (Chivers, 1972). I replace a description of sociality based on mating system and group size/composition with quantitative measurement of social interactions and spatial relations between wild adult males and females in three heterosexual pairs of siamang and two pairs of white-handed gibbons studied for 2.5 years at the Ketambe Research Station (Sumatra, Indonesia). Siamang pair bonds show greater heterosexual cohesion than those of white-handed gibbon as reflected in higher rates of affinitive interactions such as close proximity, relaxed physical contact, embraces, and communal use of sleep trees. Although males are more responsible than females for the maintenance of close proximity in both species, sex differences in intra-pair allogrooming suggest divergent mechanisms maintaining pair bonds in the two species. In white-handed gibbons, the female rarely initiates grooming and grooms her mate significantly less than he grooms her, partly because she solicits grooming from him at higher rates while simultaneously ignoring more of his 'presents' for grooming. In siamang, the contributions of the sexes to grooming are more equivalent and reciprocal. Taken together, these results suggest that investment of the sexes in maintaining the pair bond is more asymmetrical in white-handed gibbons (i.e. males contribute relatively more than females) and more mutual in siamang. Although mate guarding may have been the selective force behind the origin of pair bonds in both species, greater intra-group feeding competition in the gibbon and substantial paternal care in the siamang may account for the evolution of more reciprocal and stronger pair bonds in the latter. Future research on more groups is necessary to clarify the proposed species differences in light of existing intraspecific variation in social behavior.

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DALY, K. E., J. W. M. CHOW, and R. H. VICKERS. "Excision of the Hamate for an Unusual Hand Tumour." Journal of Hand Surgery 18, no. 5 (October 1993): 606–8. http://dx.doi.org/10.1016/0266-7681(93)90014-7.

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A right-handed man with an enlarging bony swelling of his dominant hand developed symptoms of median and ulnar nerve compression. He underwent simple excision of the hamate and histology showed the lesion to be a benign chondroblastoma. At 2-year follow-up he was found to be doing a heavy manual job with no functional problems and there were no signs of recurrence of the tumour. To our knowledge this is the first reported case of a benign hand tumour treated by simple excision of the hamate.

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Kim, Jaeyoung, and Jonathan Day. "Establishing a New Bony Landmark for Safe Screw Insertion in Medial Displacement Calcaneal Osteotomy: A Simulation-Based Approach." Foot & Ankle Orthopaedics 5, no. 4 (October 1, 2020): 2473011420S0029. http://dx.doi.org/10.1177/2473011420s00290.

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Category: Hindfoot; Other Introduction/Purpose: Medial displacement calcaneal osteotomy (MDCO) is a commonly performed procedure in flatfoot reconstruction. Fixation is often achieved with screws due to its ability to compress across the osteotomy site. Screws are placed via a free-handed technique without direct fluoroscopic visualization, due to difficulty attaining a simultaneous axial calcaneal view. In addition, the posterior calcaneal tuber translates medially after displacement, resulting in altered anatomical geometry. It is therefore important to establish a reliable external bony landmark when performing free-handed interfragmentary fixation in order to avoid potential screw-related complications and to provide better surgical technique and fixation. The purposes of this study are to validate a new external bony landmark and to establish the appropriate trajectory and screw length for free-hand screw fixation in MDCO. Methods: A total of 84 postoperative computed tomography (CT) scans of MDCO in 70 patients were analyzed. The images were reconstructed using a 3-dimensional simulation program (Vworks 4.0, Cybermed). Virtual screw insertion was simulated by aiming towards two bony landmarks: the base of the 5th metatarsal in the axial plane, and the sinus tarsi in the sagittal plane (Figure 1). A grading system was also utilized to classify scenarios in which the screw breached the distal cortical wall: Grade 1 was defined as contact between the virtual screw and the cortex, Grade 2 as the screw approaching the outer margin of the cortex, and Grade 3 as the screw penetrating the outer cortex. The trajectory angle between the screw and the osteotomy, as well as the screw size, were also measured. Results: The average age of patients was 24.5 (range, 19 to 53), and 100% were males. The average displacement of the posterior calcaneal fragment was 7.3+-1.5 mm (range, 3.9 to 13.8). Among the 84 virtual screws, only five (6.0%) breached the medial cortical wall of the osteotomized calcaneus. All medial breaches were Grade 1. None of the virtual screws breached the lateral cortical wall. Mean trajectory angle between the virtual screw and the osteotomy site was 74.9+-6.7˚ (range, 60.0 to 89.8˚). In the perioperative data, estimated maximum screw length by simulation was 55.6+-4.4 mm (range, 50 to 65). Conclusion: Our results suggest that the optimal trajectory of free-handed screw placement can be determined through simulation of calcaneal interfragmentary screw insertion using postoperative CT imaging. Using this simulation technology, we determined a trajectory towards the sinus tarsi on the sagittal plane and the base of the 5th metatarsal on the axial plane to be a reliable external bony landmark for placement of screws in MDCO. These promising results have potential implications in achieving better fixation as well as improving union rates and operative outcomes.

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Hansen, L., S. De Raedt, P. B. Jørgensen, B. Mygind-Klavsen, B. Kaptein, and M. Stilling. "Marker free model-based radiostereometric analysis for evaluation of hip joint kinematics." Bone & Joint Research 7, no. 6 (June 2018): 379–87. http://dx.doi.org/10.1302/2046-3758.76.bjr-2017-0268.r1.

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ObjectivesTo validate the precision of digitally reconstructed radiograph (DRR) radiostereometric analysis (RSA) and the model-based method (MBM) RSA with respect to benchmark marker-based (MM) RSA for evaluation of kinematics in the native hip joint.MethodsSeven human cadaveric hemipelves were CT scanned and bone models were segmented. Tantalum beads were placed in the pelvis and proximal femoral bone. RSA recordings of the hips were performed during flexion, adduction and internal rotation. Stereoradiographic recordings were all analyzed with DRR, MBM and MM. Migration results for the MBM and DRR with respect to MM were compared. Precision was assessed as systematic bias (mean difference) and random variation (Pitman’s test for equal variance).ResultsA total of 288 dynamic RSA images were analyzed. Systematic bias for DRR and MBM with respect to MM in translations (p < 0.018 mm) and rotations (p < 0.009°) were approximately 0. Pitman’s test showed lower random variation in all degrees of freedom for DRR compared with MBM (p < 0.001).ConclusionSystematic error was approximately 0 for both DRR or MBM. However, precision of DRR was statistically significantly better than MBM. Since DRR does not require marker insertion it can be used for investigation of preoperative hip kinematics in comparison with the postoperative results after joint preserving hip surgery. Cite this article: L. Hansen, S. De Raedt, P. B. Jørgensen, B. Mygind-Klavsen, B. Kaptein, M. Stilling. Marker free model-based radiostereometric analysis for evaluation of hip joint kinematics: A validation study. Bone Joint Res 2018;7:379–387. DOI: 10.1302/2046-3758.76.BJR-2017-0268.R1.

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Kalaiarasi, Chinnasamy, Mysore S. Pavan, and Poomani Kumaradhas. "Topological characterization of electron density, electrostatic potential and intermolecular interactions of 2-nitroimidazole: an experimental and theoretical study." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 72, no. 5 (September 29, 2016): 775–86. http://dx.doi.org/10.1107/s2052520616010581.

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An experimental charge density distribution of 2-nitroimidazole was determined from high-resolution X-ray diffraction and the Hansen–Coppens multipole model. The 2-nitroimidazole compound was crystallized and a high-angle X-ray diffraction intensity data set has been collected at low temperature (110 K). The structure was solved and further, an aspherical multipole model refinement was performed up to octapole level; the results were used to determine the structure, bond topological and electrostatic properties of the molecule. In the crystal, the molecule exhibits a planar structure and forms weak and strong intermolecular hydrogen-bonding interactions with the neighbouring molecules. The Hirshfeld surface of the molecule was plotted, which explores different types of intermolecular interactions and their strength. The topological analysis of electron density at the bond critical points (b.c.p.) of the molecule was performed, from that the electron density ρbcp(r) and the Laplacian of electron density ∇2ρbcp(r) at the b.c.p.s of the molecule have been determined; these parameters show the charge concentration/depletion of the nitroimidazole bonds in the crystal. The electrostatic parameters like atomic charges and the dipole moment of the molecule were calculated. The electrostatic potential surface of the molecule has been plotted, and it displays a large electronegative region around the nitro group. All the experimental results were compared with the corresponding theoretical calculations performed usingCRYSTAL09.

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Dane, Senol, Sedat Akar, Ibrahim Hacibeyoglu, and Erhan Varoglu. "Differences Between Right-and Left-Femoral Bone Mineral Densities in Right-and Left-Handed Men and Women." International Journal of Neuroscience 111, no. 3-4 (January 2001): 187–92. http://dx.doi.org/10.3109/00207450108994230.

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Khan, Kamruzzaman, M. Ali Akbar, and Norhashidah Hj Mohd Ali. "The Modified Simple Equation Method for Exact and Solitary Wave Solutions of Nonlinear Evolution Equation: The GZK-BBM Equation and Right-Handed Noncommutative Burgers Equations." ISRN Mathematical Physics 2013 (February 25, 2013): 1–5. http://dx.doi.org/10.1155/2013/146704.

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The modified simple equation method is significant for finding the exact traveling wave solutions of nonlinear evolution equations (NLEEs) in mathematical physics. In this paper, we bring in the modified simple equation (MSE) method for solving NLEEs via the Generalized Zakharov-Kuznetsov-Benjamin-Bona-Mahony (GZK-BBM) equation and the right-handed noncommutative Burgers' (nc-Burgers) equations and achieve the exact solutions involving parameters. When the parameters are taken as special values, the solitary wave solutions are originated from the traveling wave solutions. It is established that the MSE method offers a further influential mathematical tool for constructing the exact solutions of NLEEs in mathematical physics.

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Britton, Luke, Jamie H. Docherty, Andrew P. Dominey, and Stephen P. Thomas. "Iron-Catalysed C(sp2)-H Borylation Enabled by Carboxylate Activation." Molecules 25, no. 4 (February 18, 2020): 905. http://dx.doi.org/10.3390/molecules25040905.

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Arene C(sp2)-H bond borylation reactions provide rapid and efficient routes to synthetically versatile boronic esters. While iridium catalysts are well established for this reaction, the discovery and development of methods using Earth-abundant alternatives is limited to just a few examples. Applying an in situ catalyst activation method using air-stable and easily handed reagents, the iron-catalysed C(sp2)-H borylation reactions of furans and thiophenes under blue light irradiation have been developed. Key reaction intermediates have been prepared and characterised, and suggest two mechanistic pathways are in action involving both C-H metallation and the formation of an iron boryl species.

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Nassour, Ayoub, Maciej Kubicki, Jonathan Wright, Teresa Borowiak, Grzegorz Dutkiewicz, Claude Lecomte, and Christian Jelsch. "Charge-density analysis using multipolar atom and spherical charge models: 2-methyl-1,3-cyclopentanedione, a compound displaying a resonance-assisted hydrogen bond." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 70, no. 2 (March 4, 2014): 197–211. http://dx.doi.org/10.1107/s2052520613031375.

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The experimental charge-density distribution in 2-methyl-1,3-cyclopentanedione in the crystal state was analyzed by synchrotron X-ray diffraction data collection at 0.33 Å resolution. The molecule in the crystal is in the enol form. The experimental electron density was refined using the Hansen–Coppens multipolar model and an alternative modeling, based on spherical atoms and additional charges on the covalent bonds and electron lone-pair sites. The crystallographic refinements, charge-density distributions, molecular electrostatic potentials, dipole moments and intermolecular interaction energies obtained from the different charge-density models were compared. The experimental results are also compared with the theoretical charge densities using theoretical structure factors obtained from periodic quantum calculations at the B3LYP/6-31G** level. A strong intermolecular O—H...O hydrogen bond connects molecules along the [001] direction. The deformation density maps show the resonance within the O=C—C=C—OH fragment and merged lone pair lobes on the hydroxyl O atom. This resonance is further confirmed by the analysis of charges and topology of the electron density.

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Druzhbin, Dmitry, Tatiana Drebushchak, and Elena Boldyreva. "Charge density analysis of paracetamol, acetotoluidine and methacetin." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C541. http://dx.doi.org/10.1107/s2053273314094583.

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Paracetamol (p-hydroxyacetanilide, Pbca), acetotoluidine (p-methylacetanilide, P21/c) and methacetin (p-methoxyacetanilide, Pbca) contain acetamide group included in molecular fragments, which play an important role in many drugs and proteins. As all of them are derivatives of acetanilide used in medicine, and due to the presence of the amide bond, their charge density analysis is important for better understanding amide infinite peptide chains. Thus, comparing the data obtained for paracetamol with acetotoluidine and with methacetin charge density data can provide deeper insight into NH···O bonding. Another point of interest is the possibility of methyl group rotation that remains to be ambiguous in these acetanilide molecule based compounds. In the present study we have attempted to elucidate these problems using precise X-ray diffraction at 100K with subsequent charge density topological analysis. All charge density refinements were based on the Hansen and Coppens multipolar atom model. The topologies of the inter- and intramolecular interactions are carefully analyzed for compounds. The atomic charges, bond orders, and the electrostatic energy in molecules are discussed. The topological characteristics in the critical point of the NH···O bond of paracetamol, acetotoluidine and methacetin are shown in the table below. In contrast to similarity in NH···O bonds for all studied compounds, intermolecular interactions between the double bonded oxygen atom and the hydrogen of dimer's methyl group are different. In acetotoluidine and methacetin the (3, –1) critical points with the same topological characteristics were detected between these atoms. In comparison to them, paracetamol with disordered methyl group [1, 2] has no such point. That can be related to the absence of the methyl group disorder in acetotoluidine and methacetin.

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Van Doorne, Luc, Pedram Gholami, Jan D’haese, Geert Hommez, Gert Meijer, and Hugo De Bruyn. "Three-Dimensional Radiographic Outcome of Free-Handed Flaplessly Placed Mini Dental Implants in Edentulous Maxillae after 2-Years Function." Journal of Clinical Medicine 9, no. 7 (July 5, 2020): 2120. http://dx.doi.org/10.3390/jcm9072120.

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Background: Free-handed, flaplessly placed mini dental implants (MDIs) are a valuable, more affordable and minimally invasive treatment to support overdentures in fully edentulous jaws, especially for medically compromised patients. However, critical 3D radiographic evaluation is lacking. This multicenter prospective case series assessed clinical outcome and carried out 3D- cone-beam computerized tomography (CBCT) analysis of free-handed flaplessly placed one-piece maxillary MDIs by an experienced maxillofacial surgeon. Methods: Thirty-one patients suffering from an ill-fitting maxillary denture relating to compromised bone volume (as confirmed on CBCT), with a dentate mandible, were selected. They received 5–6 MDIs free-hand flaplessly placed and mentally guided with preoperative CBCT. Final connection and attachment activation took place six months later. After two years each implant was individually assessed with CBCT for perforations on eight sites. Implant survival, prosthetic failure, clinical stability and sinus/nasal complaints were registered after three years. Results: 32/185 (17.3%) MDIs failed during the provisional loading with non-activated attachments; 17 replacements in 10 patients were performed. Of the 170 actively loaded 170 MDIs, 82.3% survived and 27/31 prostheses (87%) were fully functional. In total 98/170 MDIs showed no perforation. Based on 1360 CBCT observations, 231 perforations (16.9%) were registered. Of most perforations 37 (25%) were observed at the apical tip and 37 were positioned (21%) into the sinus/nasal cavity, although without clinical complaints. Conclusions: Given the compromised population, the minimally invasive procedure and the low treatment cost involved, a failure rate of 17% is substantial, however clinically acceptable given the critical bone condition. However, even in experienced surgical hands, freehanded and flapless placement yield a high risk for implant perforation, although this did not necessarily lead to complications.

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Naebi, Ahmad, Zuren Feng, Farhoud Hosseinpour, and Gahder Abdollahi. "Dimension Reduction Using New Bond Graph Algorithm and Deep Learning Pooling on EEG Signals for BCI." Applied Sciences 11, no. 18 (September 20, 2021): 8761. http://dx.doi.org/10.3390/app11188761.

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One of the main challenges in studying brain signals is the large size of the data due to the use of many electrodes and the time-consuming sampling. Choosing the right dimensional reduction method can lead to a reduction in the data processing time. Evolutionary algorithms are one of the methods used to reduce the dimensions in the field of EEG brain signals, which have shown better performance than other common methods. In this article, (1) a new Bond Graph algorithm (BGA) is introduced that has demonstrated better performance on eight benchmark functions compared to genetic algorithm and particle swarm optimization. Our algorithm has fast convergence and does not get stuck in local optimums. (2) Reductions of features, electrodes, and the frequency range have been evaluated simultaneously for brain signals (left-handed and right-handed). BGA and other algorithms are used to reduce features. (3) Feature extraction and feature selection (with algorithms) for time domain, frequency domain, wavelet coefficients, and autoregression have been studied as well as electrode reduction and frequency interval reduction. (4) First, the features/properties (algorithms) are reduced, the electrodes are reduced, and the frequency range is reduced, which is followed by the construction of new signals based on the proposed formulas. Then, a Common Spatial Pattern is used to remove noise and feature extraction and is classified by a classifier. (5) A separate study with a deep sampling method has been implemented as feature selection in several layers with functions and different window sizes. This part is also associated with reducing the feature and reducing the frequency range. All items expressed in data set IIa from BCI competition IV (the left hand and right hand) have been evaluated between one and three channels, with better results for similar cases (in close proximity). Our method demonstrated an increased accuracy by 5 to 8% and an increased kappa by 5%.

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Tchoń, Daniel, Anna Makal, Matthias Gutmann, and Krzysztof Woźniak. "Doxycycline hydrate and doxycycline hydrochloride dihydrate – crystal structure and charge density analysis." Zeitschrift für Kristallographie - Crystalline Materials 233, no. 9-10 (September 25, 2018): 649–61. http://dx.doi.org/10.1515/zkri-2018-2058.

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Abstract High-resolution low-temperature X-ray diffraction experiments for doxycycline monohydrate and hydrochloride dihydrate have been performed. Translation-Libration-Screw (TLS) analysis for both crystal forms as well as the data from neutron diffraction experiment for hydrochloride combined with the Hansen-Coppens formalism resulted in precise charge density distribution models for both the zwitterionic monohydrate and a protonated hydrochloride crystal forms. Their detailed topological analysis suggested that the electron structure of doxycycline’s amide moiety undergoes significant changes during protonation due to formation of a very strong resonance-assisted hydrogen bond. A notably increased participation of amide nitrogen atom and hydrogen-accepting oxygen atom in the resonance upon doxycycline protonation was observed. A comparison of TLS- and neutron data-derived hydrogen parameters confirmed the experimental neutron data to be vital for proper description of intra- and inter-molecular interactions in this compound. Finally, calculated lattice and interaction energies quantified repulsive Dox-Dox interactions in the protonated crystal form of the antibiotic, relating with a good solubility of doxycycline hydrochloride relative to its hydrate.

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Wolstenholme, David, Manuel AS Aquino, T. Stanley Cameron, Joseph D. Ferrara, and Katherine N. Robertson. "A topological analysis of the interion interactions of tetraphenylphosphonium squarate." Canadian Journal of Chemistry 84, no. 5 (May 1, 2006): 804–11. http://dx.doi.org/10.1139/v06-058.

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The tetraphenylphosphonium squarate salt crystallizes with a number of diverse interactions, which all have the potential to be classified as hydrogen bonds. The squarate anions are found as dimers linked by O-H···O interactions. The multipole refinement of the tetraphenylphosphonium squarate was performed using the HansenCoppens model followed by topological analysis of its intermolecular interactions. A total of 28 interactions were found among the symmetry related molecules, which include a number of C-H···Cπ, C-H···O, and C-H···H-C interactions, along with the O-H···O interaction. With the criteria for hydrogen bonding proposed by Popelier and Koch, it is possible to determine which of these interactions are hydrogen bonds and which are van der Waals interactions. Both linear and exponentially dependent correlations can be seen for the properties of the bond critical points involving the intermolecular interactions that fulfill these criteria. All this leads to a better understanding of the role that hydrogen bonds play in the formation of small organic compounds.Key words: electron density, multiple refinement, hydrogen bonds.

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Harp, Joel M., Leighton Coates, Brendan Sullivan, and Martin Egli. "Water structure around a left-handed Z-DNA fragment analyzed by cryo neutron crystallography." Nucleic Acids Research 49, no. 8 (April 19, 2021): 4782–92. http://dx.doi.org/10.1093/nar/gkab264.

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Abstract Even in high-quality X-ray crystal structures of oligonucleotides determined at a resolution of 1 Å or higher, the orientations of first-shell water molecules remain unclear. We used cryo neutron crystallography to gain insight into the H-bonding patterns of water molecules around the left-handed Z-DNA duplex [d(CGCGCG)]2. The neutron density visualized at 1.5 Å resolution for the first time allows us to pinpoint the orientations of most of the water molecules directly contacting the DNA and of many second-shell waters. In particular, H-bond acceptor and donor patterns for water participating in prominent hydration motifs inside the minor groove, on the convex surface or bridging nucleobase and phosphate oxygen atoms are finally revealed. Several water molecules display entirely unexpected orientations. For example, a water molecule located at H-bonding distance from O6 keto oxygen atoms of two adjacent guanines directs both its deuterium atoms away from the keto groups. Exocyclic amino groups of guanine (N2) and cytosine (N4) unexpectedly stabilize waters H-bonded to O2 keto oxygens from adjacent cytosines and O6 keto oxygens from adjacent guanines, respectively. Our structure offers the most detailed view to date of DNA solvation in the solid-state undistorted by metal ions or polyamines.

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Tsirelson, Vladimir G., Anastasia V. Shishkina, Adam I. Stash, and Simon Parsons. "The experimental and theoretical QTAIMC study of the atomic and molecular interactions in dinitrogen tetroxide." Acta Crystallographica Section B Structural Science 65, no. 5 (August 28, 2009): 647–58. http://dx.doi.org/10.1107/s0108768109028821.

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The atomic and molecular interactions in a crystal of dinitrogen tetraoxide, α-N2O4, have been studied in terms of the quantum topological theory of molecular structure using high-resolution, low-temperature X-ray diffraction data. The experimental electron density and electrostatic potential have been reconstructed with the Hansen–Coppens multipole model. In addition, the three-dimensional periodic electron density of crystalline α-N2O4 has been calculated at the B3LYP/cc-pVDZ level of theory with and without the geometry optimization. The application of the quantum theory of atoms in molecules and crystals (QTAIMC) recovered the two types of intermolecular bond paths between O atoms in crystalline α-N2O4, one measuring 3.094, the other 3.116 Å. The three-dimensional distribution of the Laplacian of the electron density around the O atoms showed that the lumps in the negative Laplacian fit the holes on the O atoms in the adjacent molecules, both atoms being linked by the intermolecular bond paths. This shows that the Lewis-type molecular complementarity contributes significantly to intermolecular bonding in crystalline N2O4. Partial overlap of atomic-like basins created by zero-flux surfaces in both the electron density and the electrostatic potential show that attractive electrostatic interaction exists between O atoms even though they carry the same net formal charge. The exchange and correlation contributions to the potential energy density were also computed by means of the model functionals, which use the experimental electron density and its derivatives. It was found that the intermolecular interactions in α-N2O4 are accompanied by the correlation energy-density `bridges' lowering the local potential energy along the intermolecular O...O bond paths in the electron density, while the exchange energy density governs the shape of bounded molecules.

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Li, Huimeng. "Application of CT Medical Imaging Technology in the Diagnosis of the Impact of Exercise on the Development of Adolescent Metacarpal Bone." Journal of Medical Imaging and Health Informatics 11, no. 1 (January 1, 2021): 288–94. http://dx.doi.org/10.1166/jmihi.2021.3444.

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Objective: Based on the principles of sports biomechanics, this paper uses CT medical imaging technology to observe the effect of volleyball on the morphology and structure of the metacarpal bone. Methods: Nine young professional volleyball players (volleyball group) and 8 non-volleyball players (control group) were selected from our province. They were male and right-handed. Scan the subject's hand with multi-layer spiral CT, and perform 2D and 3D reconstruction on it. The 2D reconstructed image is filtered, grayed, enlarged, intercepted, enhanced, and segmented to measure the gray value of each metacarpal bone. After manual segmentation of the 3D reconstructed image in the workstation, the CT value, length, volume, and width of each side of the metacarpal head were measured, and the size and index of each metacarpal head were calculated. Statistical analysis of differences in metacarpal parameter values. Results: Compared with the control group, (1) the volleyball group reduced the gray value of the right hand I, V metacarpal and left hand I to V metacarpal bones (P < 0.05), and the right hand II metacarpal bone decreased. (P < 0.001), the gray value of the third and fourth metacarpal bones of the right hand decreased (P < 0.01); Conclusion : The stress caused by volleyball can adaptively change the morphology and structure of the metacarpal bones of young athletes, as follows: Values, CT values decreased; metacarpal length, volume, and metacarpal head size (volume) increased; metacarpal head index decreased; in addition, non-snooker palm bone morphology and structure changed similarly to the spiker.

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Ivanov, Yury, Tatsuya Nimura, and Kiyoaki Tanaka. "Electron density and electrostatic potential of KMnF3: a phase-transition study." Acta Crystallographica Section B Structural Science 60, no. 4 (July 19, 2004): 359–68. http://dx.doi.org/10.1107/s0108768104009437.

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Three accurate X-ray diffraction experiments (Mo Kα, T = 190, 240 and 298 K) were carried out to track the temperature dependence of the electron density in the cubic perovskite potassium manganese trifluoride, KMnF3, from room temperature to just above that of the phase transition to the tetragonal structure (186 K), and to correlate the parameters of the critical points with the phase-transition mechanism. The data obtained were approximated by the Hansen–Coppens multipole model expanded up to hexadecupoles; the anharmonicity of the atomic displacements up to the fourth level was considered. Topological analysis shows only two types of chemical bond at room temperature, Mn—F and K—F. However, at low temperature the K—F bonds blocking the rotation of the MnF6 octahedra are weakened and new Mn—K bonds are formed to keep the crystal structure from disintegrating. The Mn—K bonds become stronger as the temperature approaches 186 K. This rearrangement of chemical bonds can be regarded as a precursor effect, which starts 50–60° above the phase-transition temperature. The effective one-particle potential of the F atom has a single minimum at 298 K and four well separated minima (with a shift of 0.2 Å from the equilibrium position towards the structural holes) at 190 K. Parameters of the critical points of the electron density indicate closed-shell type interactions between K—F and Mn—K pairs, whereas the Mn—F bond can be considered as an intermediate type. The topology of the electrostatic potentials is discussed as well.

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Chen, Yu-Sheng, Adam I. Stash, and A. Alan Pinkerton. "Chemical bonding and intermolecular interactions in energetic materials: 1,3,4-trinitro-7,8-diazapentalene." Acta Crystallographica Section B Structural Science 63, no. 2 (March 16, 2007): 309–18. http://dx.doi.org/10.1107/s010876810700242x.

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The electron density and related properties of the red-colored energetic material 1,3,4-trinitro-7,8-diazapentalene (space group Pca21) have been determined from a low-temperature [90.0 (1) K] X-ray diffraction experiment. Intensity data were measured with a 2 K CCD Bruker diffractometer using Ag Kα radiation. One detector setting, several φ settings, 0.15° ω scans and 96 s exposure time per frame gave R int = 0.0188 for 31 952 (10 283 unique) reflections and (sin θ/λ)max = 1.15 Å−1. The electron density was modeled using the Hansen–Coppens [(1978), Acta Cryst. A34, 909–921] multipole model and refined to R = 0.026 for 9455 unique observed reflections. The electron density, Laplacian and electrostatic potential distributions are reported and discussed. The properties of the bond (3,−1) critical points are analyzed. All results are indicative of multiple bonds in the five-membered rings. In addition, a significant number of weak intermolecular interactions (O...H, O...O, O...N, O...C) have also been characterized by the properties of their critical points. A comparison of experimental results with those obtained from theoretical calculations (periodic, CRYSTAL98; single molecule, GAUSSIAN98) is also reported.

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Fischer, Andreas, Georg Eickerling, and Wolfgang Scherer. "The Effects of Chemical Bonding at Subatomic Resolution: A Case Study on α-Boron." Molecules 26, no. 14 (July 14, 2021): 4270. http://dx.doi.org/10.3390/molecules26144270.

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Similar to classical asphericity shifts, aspherical deformations of the electron density in the atomic core region can result in core asphericity shifts in refinements using a Hansen-Coppens multipolar model (HCM), especially when highly precise experimental datasets with resolutions far beyond sin(θ)/λ ≤ 1.0 Å−1 are employed. These shifts are about two orders of magnitude smaller than their counterparts caused by valence shell deformations, and their underlying deformations are mainly of dipolar character for 1st row atoms. Here, we analyze the resolution dependence of core asphericity shifts in α-boron. Based on theoretical structure factors, an appropriate Extended HCM (EHCM) is developed, which is tested against experimental high-resolution (sin(θ)/λ ≤ 1.6 Å−1) single-crystal diffraction data. Bond length deviations due to core asphericity shifts of α-boron in the order of 4–6·10−4 Å are small but significant at this resolution and can be effectively compensated by an EHCM, although the correlation of the additional model parameters with positional parameters prevented a free refinement of all core model parameters. For high quality, high resolution data, a proper treatment with an EHCM or other equivalent methods is therefore highly recommended.

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Perényi, Ádám, Bálint Posta, Linda Szabó, Zoltán Tóbiás, Balázs Dimák, Roland Nagy, Gyöngyi Jónás, et al. "A VOXEL-MAN Tempo 3D virtuálisvalóság-szimulátor alkalmazása a sziklacsont sebészetében." Orvosi Hetilap 162, no. 16 (April 18, 2021): 623–28. http://dx.doi.org/10.1556/650.2021.32053.

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Összefoglaló. Bevezetés: Az emberi sziklacsont a halántékcsont része, egy bonyolult és változatos anatómiai felépítésű struktúra. A sziklacsonton végzett beavatkozások előtt, a műtéti szövődmények megelőzése érdekében, nélkülözhetetlen a biztos anatómiai tudás és kézügyesség megszerzése, valamint az egyes műtéti lépések és mozdulatok begyakorlása. A VOXEL-MAN Tempo 3D fül-orr-gégészeti szimulátor a virtuális valóság és a robotika alkalmazásával nyújt gyakorlási lehetőséget. Célkitűzés: A Szegedi Tudományegyetem 2019-ben VOXEL-MAN fül-orr-gégészeti szimulátort helyezett üzembe az Orvosi Készségfejlesztési Központban. A cikk fül-orr-gégész szakorvos szerzői a VOXEL-MAN Tempo szimulátor megismerését követően bemutatják a készüléket, és megfogalmazzák a szimulátorral végzett beavatkozásokkal szemben támasztott igényüket. Módszer: A szerzők a megfogalmazott szempontoknak megfelelően értékelik a VOXEL-MAN Tempo szimulátort, és meghatározzák, milyen szerepet szánnak neki a gyakorlati képzésben. Eredmények: A szimulátor virtuálisan, mégis valósághűen mutatja meg a sziklacsont anatómiai viszonyait, a fontos anatómiai struktúrák valós térbeli elhelyezkedését és egymástól, illetve a sebészi eszköztől mért távolságát. A rendszer lehetővé teszi a fülműtétek valósághű elvégzését (kétkezes csontmunka fúróval és szívóval, vérzés szimulálása) taktilis visszacsatolással. Az egy- vagy kétkezes feladatokkal fejleszthetjük a sebészi készségeket. A fülműtétek csontmunkája reprodukálható módon elvégezhető valódi beteg halántékcsontjáról készített rutin, nagy felbontású komputertomográfiás vizsgálat anyagából. Következtetés: Tapasztalataink alapján a szimulátor kiválóan alkalmas az egyes műtéti lépesek begyakorlására. A jövőben fontos szerepet szánunk a virtuális rendszernek a fül-orr-gégészeti graduális és a fülsebészeti posztgraduális képzésben. Orv Hetil. 2021; 162(16): 623–628. Summary. Introduction: The pars petrosa of the human temporal bone is a structure of complex and diverse anatomy. Prior to surgical interventions, in order to prevent surgical complications, it is essential to acquire sound anatomical knowledge and dexterity as well as to practice each surgical step and movement. The VOXEL-MAN Tempo 3D simulator uses virtual reality and robotics to provide an opportunity to practice. Objective: In 2019, the University of Szeged installed a VOXEL-MAN Virtual Reality simulator at the Medical Skills Development Center. After learning about the VOXEL-MAN Tempo simulator, the authors present the device and articulate their need for interventions with the simulator. Method: The VOXEL-MAN Tempo simulator is evaluated according to the formulated criteria and the role assigned to it in the practical training is determined. Results: The simulator shows the anatomical structure of the temporal bone virtually, yet realistically, the real spatial location of the important anatomical structures and their distance from each other and from the surgical instrument. The system allows ear surgery to be performed realistically (two-handed bone work with a drill and suction) with tactile (vibration) and visual (bleeding) feedback. One can improve surgical skills with one- or two-handed tasks. Bone work in ear surgeries can be performed in a reproducible manner from routine, high-resolution computer tomography of the temporal bone of a real patient. Conclusion: With reference to our experience, the simulator is excellent for practicing each surgical step. In the future, we intend to use this virtual system in undergraduate and postgraduate training in otolaryngology. Orv Hetil. 2021; 162(16): 623–628.

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Aouadi, Kaiss, Erwann Jeanneau, and Jean-Pierre Praly. "(1S,2R,2′S,3′aS,5R)-2′-[(1S)-1-Hydroxyethyl]-2-isopropyl-5,5′-dimethyl-3′,3′a-dihydro-2′H-spiro[cyclohexane-1,6′-imidazo[1,5-b]isoxazol]-4′(5′H)-one." Acta Crystallographica Section E Structure Reports Online 63, no. 3 (February 14, 2007): o1324—o1326. http://dx.doi.org/10.1107/s1600536807006812.

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Cycloaddition of a (−)-menthone-derived nitrone to racemic but-3-en-2-ol led to two spirobicyclic heterocycles, with opposite configurations at the C atom attached to the OH group. This paper describes the R epimer of the 1-hydroxyethyl substituent in imidazoisoxazole C17H30N2O3, (I). The S epimer, (II), is presented in the next article [Aouadi, Jeanneau & Praly (2007), Acta Cryst. E67, o1327–o1329]. The absolute configurations of both epimers were assigned from the known configuration of the starting (−)-menthone derived nitrone. In (I), there is an O—H...O hydrogen bond (O—H...O = 1.96 Å and O—H...O = 168°) that links the molecules into left-handed helices along the b axis. In addition, there are C—H...O and C—H...N hydrogen bonds.

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Shimamoto, Shigeru, Mayu Fukutsuji, Toi Osumi, Masaya Goto, Hiroshi Toyoda, and Yuji Hidaka. "Topological Regulation of the Bioactive Conformation of a Disulfide-Rich Peptide, Heat-Stable Enterotoxin." Molecules 25, no. 20 (October 21, 2020): 4798. http://dx.doi.org/10.3390/molecules25204798.

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Heat-stable enterotoxin (STa) produced by enterotoxigenic E. coli causes acute diarrhea and also can be used as a specific probe for colorectal cancer cells. STa contains three intra-molecular disulfide bonds (C1–C4, C2–C5, and C3–C6 connectivity). The chemical synthesis of STa provided not only the native type of STa but also a topological isomer that had the native disulfide pairings. Interestingly, the activity of the topological isomer was approximately 1/10–1/2 that of the native STa. To further investigate the bioactive conformation of this molecule and the regulation of disulfide-coupled folding during its chemical syntheses, we examined the folding mechanism of STa that occurs during its chemical synthesis. The folding intermediate of STa with two disulfide bonds (C1–C4 and C3–C6) and two Cys(Acm) residues, the precursor peptide, was treated with iodine to produce a third disulfide bond under several conditions. The topological isomer was predominantly produced under all conditions tested, along with trace amounts of the native type of STa. In addition, NMR measurements indicated that the topological isomer has a left-handed spiral structure similar to that of the precursor peptide, while the native type of STa had a right-handed spiral structure. These results indicate that the order of the regioselective formation of disulfide bonds is important for the regulation of the final conformation of disulfide-rich peptides in chemical synthesis.

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Pieper, Hans-Gerd. "Humeral Torsion in the Throwing Arm of Handball Players." American Journal of Sports Medicine 26, no. 2 (March 1998): 247–53. http://dx.doi.org/10.1177/03635465980260021501.

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Sport-specific upper extremity strain, mostly unilateral, during growth may lead to adaptations in soft tissue and bone. We investigated 51 male professional handball players between 18 and 39 years of age (average, 27 years), 39 right-handed and 12 left-handed. Thirty-eight players had no shoulder problems, and 13 had chronic shoulder pain. Humeral retrotorsion was determined by radiograph. The differences between the throwing and contralateral arms were compared with those of 37 controls who had no history of unilateral strain either through sports or profession. Standard statistical analysis was performed using the t-test. The retrotorsional angle of the humerus in the handball professionals' throwing arm was an average of 9.4° larger in the dominant side than in the nondominant, with a side-to-side difference up to 29°. In the control group, no statistically significant difference was found. In the group without chronic shoulder pain, the side-to-side difference was an average of 14.4° more in the throwing arm than the other side. Players with chronic shoulder pain did not exhibit this increase, even showing an average decrease of humeral retrotorsion of 5.2° in the throwing arm. The humeral retrotorsion increase can be explained as an adaptation to extensive external rotation in throwing practice during growth. Athletes who do not adapt this way seem to have more strain on their anterior capsules at less external rotation and develop chronic shoulder pain because of anterior instability.

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Koba, Yurie, Atsushi Ueda, Makoto Oba, Mitsunobu Doi, Takuma Kato, Yosuke Demizu, and Masakazu Tanaka. "Left-Handed Helix of Three-Membered Ring Amino Acid Homopeptide Interrupted by an N–H···Ethereal O-Type Hydrogen Bond." Organic Letters 20, no. 24 (November 30, 2018): 7830–34. http://dx.doi.org/10.1021/acs.orglett.8b03331.

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Journal articles on the topic 'Hansea (Bonn)'

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