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排序方式: 共有1119条查询结果,搜索用时 10 毫秒
991.
To determine the effect of the swing-through crutch-walking gait on shoulder degeneration, 20 shoulders were examined in ten patients who had used the swing-through gait for a mean of 8.7 years. No degenerative changes were found in the 20 examined shoulders either clinically or radiographically. A special X-ray view was determined to assess potential degenerative changes. The patients showed a mean increase in the forearm bone density as a result of their crutch-walking gait. 相似文献
992.
In this paper, the governing equations which consider dynamic fluid-structure interaction, modal coupling in both axial and circumferential directions, and dynamic buckling are derived. The various pressure components acting on the shell wall due to a seismic event are also analyzed. The matrix equation of motion for liquid-filled shells is obtained through a Galerkin/Finite Element discretization procedure. The modal coupling among the various combinations of axial and circumferential modes are identified with a particular reference to the fluid-structure system under seismic excitation. Finally, the equations for the dynamic stability analysis of liquid-filled shells are presented. 相似文献
993.
YK Xu FR Kaufman GN Donnell T Giudici O Alfi WG Ng 《Canadian Metallurgical Quarterly》1995,240(1):21-33
Neuroanatomical studies have demonstrated that the organization of the reptilian rubrocerebellar limb premotor network is similar to that of mammals. This network is composed of prominent recurrent connections among the red nucleus, lateral cerebellar nucleus and lateral reticular nucleus. In this paper the rubrocerebellar system of the turtle was three-dimensionally reconstructed to permit detailed examination of its anatomical organization. Each nucleus and its major efferent pathway was imaged and reconstructed from separate anatomical cases. Section images were used to draw tissue boundaries, mark cell positions and locate axonal trajectories. For each nucleus, drawings of section images containing labeled cells were stacked in the rostrocaudal direction using anatomical landmarks, and a graphic model of the surface was constructed using the method of triangulation. An ellipsoid of equal concentration was computed for each nucleus to ascertain their three-dimensional boundaries and location within the brainstem. To examine the entire rubrocerebellar network, a template of the turtle brainstem and cerebellum was constructed. The component nuclei of the rubrocerebellar network and their axonal projections were then spatially warped onto the template reconstruction on a section by section basis. The final three-dimensional reconstruction of the turtle rubrocerebellar limb premotor network could be rotated in space, allowing proper visualization of the anatomical details of this system. Furthermore, we were able to mathematically section through the reconstruction to obtain brainstem slices with differing orientations and thickness. 相似文献
994.
AIMS/BACKGROUND: Potenlini is an injectable compound whose active component is glycyrrhizin, which is extracted from licorice. Previous studies showed that it could reduce liver injury, improve alanine aminotransferase (ALT) levels and act as an antifibrotic agent. However, the mechanism of its action remains unclear. The aim of this study was to determine the molecular mechanism of its action by investigating the effects of potenlini on nuclear factor-kappaB (NF-kappaB) binding activity in an animal model of liver cirrhosis. METHODS: Rats were randomly allocated into a normal control group, a model control group, and a potenlini group. Rats in the latter two groups were treated with CCl4 and ethanol solution in order to induce chronic liver injury. Rats in the potenlini group were given potenlini treatment at the same time. RESULTS: Serum ALT levels were significantly reduced in rats treated with potenlini compared with levels in rats of the model control group, which had dramatically increased ALT levels. Histologically, liver steatosis and fibrosis were severe in the rats of the model group, but were significantly improved in rats of the potenlini group. NF-kappaB binding activity was markedly increased in the liver specimens taken from the rats of the model control group in comparison with the binding of normal livers, but the binding levels were nearly normal in the livers of the potenlini group. CONCLUSIONS: The results suggest that potenlini can inhibit the NF-kappaB binding activity in CCl4 and ethanol-induced chronic liver injury, and that effect may be a possible mechanism by which potenlini protects the liver from hepatotoxin-induced liver injury and cirrhosis. 相似文献
995.
TT Wang AS Chiang JJ Chu TJ Cheng TM Chen YK Lai 《Canadian Metallurgical Quarterly》1998,30(6):745-759
Maintenance of cell architecture and positioning of organelles are major functions of the cytoskeleton. On the other hand, induction of heat shock proteins (HSPs) and reorganization of the cytoskeleton are the most significant changes in heat-shocked mammalian cells. We examine the alterations in HSP70 and its constitutively expressed cognate, HSC70, as well as the cytoskeleton and organelles in 9L rat brain tumor cells upon heat shock. We employed fluorescence microscopy and scanning electron microscopy to follow these changes. Levels of HSP70s were quantified by Western blotting. Accumulation of HSC70 was more transient and the protein translocated to and subsequently exited from the nucleus more rapidly than HSP70. Changes in actin microfilaments include the nuclear localization of actin fraction and disappearance of cytoplasmic microfilament bundles, while the cortical actin microfilaments were almost unaffected. Furthermore, microtubules retracted slightly from the cell periphery but remained largely unchanged. In contrast, the intermediate filaments collapsed into the perinuclear region. The mitochondria converted from filamentous into granular forms and clustered in a region overlapping with the collapsed intermediate filaments. All of the above alterations are reversible and largely reverted after 8 h of recovery. The effect on Golgi organization was very transient and the apparatus assumed a normal appearance within 4 h after the heat treatment. The ER, on the other hand, was totally unaffected by the heat treatment. These observations help correlate the sequential events following a stress like heat shock and suggest possible physiological functions of these essential constituents of a cell under stress. 相似文献
996.
Zachary N. Wing Brian Wang John W. Halloran 《Journal of the American Ceramic Society》2006,89(12):3696-3700
Relative permittivities ranging from 12 to 100 were obtained from porous titania. Relative permittivities from 8 to 30 were obtained from porous calcium magnesium titanates. Porosity was introduced as microporosity by partial sintering, as 15 μm diameter spherical pores with porogens, and by fabrication of a microcellular structure with cylindrical pores. The relative permittivity as a function of porosity was compared with effective media models. Permittivity could be fitted to the Bruggeman 1/3 power law over a porosity range from 5% to 78%. 相似文献
997.
To determine the benefits of social support for weight loss and maintenance, this study recruited participants (N?=?166) either alone or with 3 friends or family members and then randomly assigned then to a standard behavioral treatment (SBT) or SBT with social support strategies. Participants recruited with friends had greater weight losses at the end of the 4-month treatment and at Month 10 follow-up. Both recruitment strategy and the social support manipulation affected treatment completion and weight-loss maintenance. In those recruited alone and given SBT, 76% completed treatment and 24% maintained their weight loss in full from Months 4 to 10. Among those recruited with friends and given SBT plus social support, 95% completed treatment and 66% maintained their weight loss in full. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
999.
BACKGROUND: ANCA have been found in patients with systemic lupus erythematosus (SLE); however, the prevalence of ANCA and their target antigens is still not certain. This study is to investigate the prevalence of ANCA and their target antigens in Chinese patients with lupus nephritis. METHODS: Ninety-five serum samples were collected from 95 renal-biopsy-proven lupus nephritis patients. Indirect immunofluorescence using ethanol-fixed leukocytes as substrate and ELISA using six highly purified known ANCA antigens as solid-phase ligands were performed. The specific ANCA antigens included proteinase 3, myeloperoxidase, bactericidal/permeability-increasing protein, human leukocyte elastase, cathepsin G, and lactoferrin. The prevalence of ANCA in patients with (n=65) and without (n=30) active renal pathological lesions was also compared to reveal whether ANCA correlates with disease activity. RESULTS: (i) None of the sera recognized proteinase 3, myeloperoxidase, and human leukocyte elastase, and only one serum recognized bactericidal/permeability-increasing protein. The striking finding was that 59/95 (62.1%) sera recognized cathepsin G and the titres of some sera reached 1/3200. Eight of 95 sera (8.4%) recognized lactoferrin. (ii) The percentage of anti-cathepsin G antibody positive samples in patients with active renal lesions was significantly higher than in patients without active lesions (73.4 vs 36.7%, P<0.0001), whereas, anti-lactoferrin antibodies had no correlation with active renal lesions. (iii) By indirect immunofluorescence, only 22% of the 95 sera were ANCA positive. CONCLUSIONS: Our results suggest that the majority of lupus nephritis patients have ANCA and that the major target antigens is cathepsin G. Anti-cathepsin G antibodies seem to be correlated with renal disease activity. 相似文献
1000.
Conformational free energy calculations using an empirical potential (ECEPP/2) and the hydration shell model were carried out on the N-acetyl-N'-methylamides of Pro-Xaa dipeptides (Xaa = Ala, Leu, Val, Gly, Cys, Met, Phe, Tyr, Asn, Asp, and Ser) with trans and cis peptide bonds preceding proline residue in the unhydrated and hydrated states. As compared with the results obtained by using the earlier version of ECEPP, the values of beta-bend probabilities are doubled. The average calculated population of cis-dipeptide is about 4%, which is close to the abundance obtained from the analysis of X-ray crystal structures of proteins. The beta-bends are the most dominant structures of cis-dipeptides. Type I, usually having intramolecular hydrogen bonds, contributes greatly to the beta-bend conformations of trans- and cis-dipeptides. However, type I beta-bends of cis-dipeptides do not have any hydrogen bonds. By including the hydration, the beta-bend probabilities for trans- and cis-dipeptides decreased, indicating that the interactions of water molecules with a backbone or side-chain may force the dipeptides to be more distorted or extended. In particular, type II is found to be a dominant beta-bend conformation of trans- and cis-Pro-Gly dipeptides in both the unhydrated and hydrated states. In general, the calculated propensities for Pro-Xaa dipeptides to adopt beta-bend conformations are reasonably consistent with available experimental data. From comparing conformations of Pro and Xaa residues in the dipeptides and single residues, we found that inter-residue interactions and hydration are of importance in determining the conformational properties of the Pro-Xaa dipeptide. 相似文献