11 resultados para TRANSVERSELY ISOTROPIC CONSTITUENTS

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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We propose a computationally efficient and biomechanically relevant soft-tissue simulation method for cranio-maxillofacial (CMF) surgery. A template-based facial muscle reconstruction was introduced to minimize the efforts on preparing a patient-specific model. A transversely isotropic mass-tensor model (MTM) was adopted to realize the effect of directional property of facial muscles in reasonable computation time. Additionally, sliding contact around teeth and mucosa was considered for more realistic simulation. Retrospective validation study with postoperative scan of a real patient showed that there were considerable improvements in simulation accuracy by incorporating template-based facial muscle anatomy and sliding contact.

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To evaluate a new isotropic 3D proton-density, turbo-spin-echo sequence with variable flip-angle distribution (PD-SPACE) sequence compared to an isotropic 3D true-fast-imaging with steady-state-precession (True-FISP) sequence and 2D standard MR sequences with regard to the new 3D magnetic resonance observation of cartilage repair tissue (MOCART) score.

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The liver has an important role in metabolic regulation and control of the somatotropic axis to adapt successfully to physiological and environmental changes in dairy cows. The aim of this study was to investigate the adaptation to negative energy balance (NEB) at parturition and to a deliberately induced NEB by feed restriction at 100 days in milk. The hepatic gene expression and the endocrine system of the somatotropic axis and related parameters were compared between the early and late NEB period. Fifty multiparous cows were subjected to 3 periods (1=early lactation up to 12 wk postpartum, 2=feed restriction for 3 wk beginning at around 100 days in milk with a feed-restricted and a control group, and 3=subsequent realimentation period for the feed-restricted group for 8 wk). In period 1, plasma growth hormone reached a maximum in early lactation, whereas insulin-like growth factor-I (IGF-I), leptin, the thyroid hormones, insulin, and the revised quantitative insulin sensitivity check index increased gradually after a nadir in early lactation. Three days after parturition, hepatic mRNA abundance of growth hormone receptor 1A, IGF-I, IGF-I receptor and IGF-binding protein-3 (IGFBP-3) were decreased, whereas mRNA of IGFBP-1 and -2 and insulin receptor were upregulated as compared with wk 3 antepartum. During period 2, feed-restricted cows showed decreased plasma concentrations of IGF-I and leptin compared with those of control cows. The revised quantitative insulin sensitivity check index was lower for feed-restricted cows (period 2) than for control cows. Compared with the NEB in period 1, the changes due to the deliberately induced NEB (period 2) in hormones were less pronounced. At the end of the 3-wk feed restriction, the mRNA abundance of IGF-I, IGFBP-1, -2, -3, and insulin receptor was increased as compared with the control group. The different effects of energy deficiency at the 2 stages in lactation show that the endocrine regulation changes qualitatively and quantitatively during the course of lactation.

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The Cannabis plant and its products consist of an enormous variety of chemicals. Some of the 483 compounds identified are unique to Cannabis, for example, the more than 60 cannabinoids, whereas the terpenes, with about 140 members forming the most abundant class, are widespread in the plant kingdom. The term “cannabinoids” [note: “ ” represents a group of C21 terpenophenolic compounds found until now uniquely in Cannabis sativa L. (1). As a consequence of the development of synthetic cannabinoids (e.g., nabilone [2], HU-211 [dexanabinol; ref. (3), or ajulemic acid [CT-3; ref. 4]) and the discovery of the chemically different endogenous cannabinoid receptor ligands (“endocannabinoids,” e.g., anandamide, 2-arachidonoylglycerol) (5,6), the term ’“phytocannabinoids’” was proposed for these particular Cannabis constituents (7).

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INTRODUCTION: Cartilage defects are common pathologies and surgical cartilage repair shows promising results. In its postoperative evaluation, the magnetic resonance observation of cartilage repair tissue (MOCART) score, using different variables to describe the constitution of the cartilage repair tissue and the surrounding structures, is widely used. High-field magnetic resonance imaging (MRI) and 3-dimensional (3D) isotropic sequences may combine ideal preconditions to enhance the diagnostic performance of cartilage imaging.Aim of this study was to introduce an improved 3D MOCART score using the possibilities of an isotropic 3D true fast imaging with steady-state precession (True-FISP) sequence in the postoperative evaluation of patients after matrix-associated autologous chondrocyte transplantation (MACT) as well as to compare the results to the conventional 2D MOCART score using standard MR sequences. MATERIAL AND METHODS: The study had approval by the local ethics commission. One hundred consecutive MR scans in 60 patients at standard follow-up intervals of 1, 3, 6, 12, 24, and 60 months after MACT of the knee joint were prospectively included. The mean follow-up interval of this cross-sectional evaluation was 21.4 +/- 20.6 months; the mean age of the patients was 35.8 +/- 9.4 years. MRI was performed at a 3.0 Tesla unit. All variables of the standard 2D MOCART score where part of the new 3D MOCART score. Furthermore, additional variables and options were included with the aims to use the capabilities of isotropic MRI, to include the results of recent studies, and to adapt to the needs of patients and physician in a clinical routine examination. A proton-density turbo spin-echo sequence, a T2-weighted dual fast spin-echo (dual-FSE) sequence, and a T1-weighted turbo inversion recovery magnitude (TIRM) sequence were used to assess the standard 2D MOCART score; an isotropic 3D-TrueFISP sequence was prepared to evaluate the new 3D MOCART score. All 9 variables of the 2D MOCART score were compared with the corresponding variables obtained by the 3D MOCART score using the Pearson correlation coefficient; additionally the subjective quality and possible artifacts of the MR sequences were analyzed. RESULTS: The correlation between the standard 2D MOCART score and the new 3D MOCART showed for the 8 variables "defect fill," "cartilage interface," "surface," "adhesions," "structure," "signal intensity," "subchondral lamina," and "effusion"-a highly significant (P < 0.001) correlation with a Pearson coefficient between 0.566 and 0.932. The variable "bone marrow edema" correlated significantly (P < 0.05; Pearson coefficient: 0.257). The subjective quality of the 3 standard MR sequences was comparable to the isotropic 3D-TrueFISP sequence. Artifacts were more frequently visible within the 3D-TrueFISP sequence. CONCLUSION: In the clinical routine follow-up after cartilage repair, the 3D MOCART score, assessed by only 1 high-resolution isotropic MR sequence, provides comparable information than the standard 2D MOCART score. Hence, the new 3D MOCART score has the potential to combine the information of the standard 2D MOCART score with the possible advantages of isotropic 3D MRI at high-field. A clear limitation of the 3D-TrueFISP sequence was the high number of artifacts. Future studies have to prove the clinical benefits of a 3D MOCART score.

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The identification of targets whose interaction is likely to result in the successful treatment of a disease is of growing interest for natural product scientists. In the current study we performed an exemplary application of a virtual parallel screening approach to identify potential targets for 16 secondary metabolites isolated and identified from the aerial parts of the medicinal plant RUTA GRAVEOLENS L. Low energy conformers of the isolated constituents were simultaneously screened against a set of 2208 pharmacophore models generated in-house for the IN SILICO prediction of putative biological targets, i. e., target fishing. Based on the predicted ligand-target interactions, we focused on three biological targets, namely acetylcholinesterase (AChE), the human rhinovirus (HRV) coat protein and the cannabinoid receptor type-2 (CB (2)). For a critical evaluation of the applied parallel screening approach, virtual hits and non-hits were assayed on the respective targets. For AChE the highest scoring virtual hit, arborinine, showed the best inhibitory IN VITRO activity on AChE (IC (50) 34.7 muM). Determination of the anti-HRV-2 effect revealed 6,7,8-trimethoxycoumarin and arborinine to be the most active antiviral constituents with IC (50) values of 11.98 muM and 3.19 muM, respectively. Of these, arborinine was predicted virtually. Of all the molecules subjected to parallel screening, one virtual CB (2) ligand was obtained, i. e., rutamarin. Interestingly, in experimental studies only this compound showed a selective activity to the CB (2) receptor ( Ki of 7.4 muM) by using a radioligand displacement assay. The applied parallel screening paradigm with constituents of R. GRAVEOLENS on three different proteins has shown promise as an IN SILICO tool for rational target fishing and pharmacological profiling of extracts and single chemical entities in natural product research.

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The provision of quality colostrum with a high concentration of immunoglobulins is critical for newborn calf health. Because first colostrum may be low in overall concentration to effectively reduce the risk of newborn infections, we tested equivalent milking fractions of colostrum for possible IgG differences. The objective of this study was to determine if the fractional composition of colostrum changes during the course of milking with a focus on immunoglobulins. Twenty-four Holstein and Simmental cows were milked (first colostrum) within 4h after calving. The colostrum of 1 gland per animal was assembled into 4 percentage fractions over the course of milking: 0 to 25%, 25 to 50%, 50 to 75%, and 75 to 100%. The IgG concentration among the various fractions did not change in any significant pattern. Concentration of protein, casein, lactose and somatic cell count remained the same or exhibited only minor changes during the course of fractional milking colostrum. We determined that no benefit exists in feeding any particular fraction of colostrum to the newborn.

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We prove that any isotropic positive definite function on the sphere can be written as the spherical self-convolution of an isotropic real-valued function. It is known that isotropic positive definite functions on d-dimensional Euclidean space admit a continuous derivative of order [(d − 1)/2]. We show that the same holds true for isotropic positive definite functions on spheres and prove that this result is optimal for all odd dimensions.

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The aim of this paper is to present a new class of smoothness testing strategies in the context of hp-adaptive refinements based on continuous Sobolev embeddings. In addition to deriving a modified form of the 1d smoothness indicators introduced in [26], they will be extended and applied to a higher dimensional framework. A few numerical experiments in the context of the hp-adaptive FEM for a linear elliptic PDE will be performed.