Search Results - (Author, Cooperation:S. Pu)

2012-09-04

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Cell Membrane/chemistry/metabolism ; Chitin Synthase/metabolism ; Detergents ; Endoplasmic Reticulum/metabolism ; Golgi Apparatus/metabolism ; Mass Spectrometry ; Membrane Proteins/analysis/chemistry/*metabolism ; Protein Binding ; Protein Interaction Mapping ; *Protein Interaction Maps ; Proteome/analysis/chemistry/metabolism ; Saccharomyces cerevisiae/chemistry/cytology/*metabolism ; Saccharomyces cerevisiae Proteins/analysis/chemistry/*metabolism

2018-01-03

The Federation of American Societies for Experimental Biology (FASEB)

0892-6638

1530-6860

Biology

1077-3118

AIP Digital Archive

Physics

Ga0.51In0.49P layers have been grown by organometallic vapor phase epitaxy on GaAs substrates with [110]-oriented grooves on the surface that have an important effect on the formation of Cu-Pt ordered structures during growth. In this work, the groove shape is demonstrated to be critically important. For the optimum groove shape, single domains of the (1¯11) and (11¯1) variants of the Cu-Pt ordered structure are formed on the two sides of the groove. Shallow grooves produce large domains on each side of the groove containing small domains of the other variant. For deep grooves, only a single variant is formed on each side of the groove, but the domains are small. For substrates with deep grooves on a GaAs substrate misoriented by 9°, every groove contains large regions of highly ordered and completely disordered material separated by a few micrometers. This allows a direct determination of the effect of ordering on the band gap of the material using cathodoluminescence spectroscopy, allowing the first direct demonstration that ordering reduces the energy band gap of a III/V alloy.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Ciliary neurotrophic factor (CNTF), a cytokine of the interleukin-6 superfamily, has been shown to induce hypophagia and weight loss. Neuropeptide Y (NPY) and orexin are potent orexigenic signals in the hypothalamus. Anorexia, normally seen in response to infection, injury and inflammation, may result from diminished hypothalamic orexigenic signalling caused by persistently elevated cytokines, including CNTF. To test this hypothesis, we first examined the effects of chronic intracerebroventricular (i.c.v.) infusion of CNTF for 6–7 days on food intake and body weight as well as hypothalamic NPY and orexin gene expression in male rats. Subsequently, the effectiveness of NPY replacement to counteract the effects of CNTF by coinfusion of NPY and CNTF was evaluated. Chronic i.c.v. infusion of CNTF (2.5 µg/day) reduced body weight (14.3% vs control) at the end of 7 days. Food intake remained suppressed for 5 days postinfusion and subsequently gradually returned to the control range by day 7. Serum leptin concentrations in these rats were in the same range seen in control rats. Chronic i.c.v. infusion of higher doses of CNTF (5.0 µg/day) produced sustained anorexia and body weight loss (29% vs controls) through the entire duration of the experiment. This severe anorexia was accompanied by markedly suppressed serum leptin concentrations. Furthermore, CNTF infusion alone significantly reduced hypothalamic NPY gene expression (P 〈 0.05) without affecting orexin gene expression. As expected, in fusion of NPY alone (18 µg/day) augmented food intake (191.6% over the initial control, P 〈 0.05) and produced a 25.1% weight gain in conjunction with a 10-fold increase in serum leptin concentrations at the end of the 7-day period. Interestingly, coinfusion of this regimen of NPY with the highly effective anorectic and body reducing effects of CNTF (5.0 µg/day) not only prevented the CNTF-induced anorexia and weight loss, but also normalized serum leptin concentrations and hypothalamic NPY gene expression. These results demonstrate that chronic central infusion to produce a persistent elevation of the cytokine at pathophysiological levels (a situation that may normally manifest during infection, injury and inflammation) produced severe anorexia and weight loss in conjunction with reduction in both serum leptin concentrations and hypothalamic NPY gene expression. Reinstatement of hypothalamic NPY signalling by coinfusion of NPY counteracted these CNTF-induced responses.

Electronic Resource

0029-5981

Engineering ; Engineering General

Wiley InterScience Backfile Collection 1832-2000

Mathematics

Technology

For the 12-node quadrilateral isoparametric elements, it is shown that the inverse square root singularity of the strain field at the crack tip can be obtained by the simple technique of collapsing the quadrilateral elements into triangular elements around the crack tip and placing the two side nodes of each side of the triangles at 1/9 and 4/9 of the length of the side from the tip. This is analogous to placing the mid-side nodes at quarter points in the vicinity of the crack tip for the quadratic isoparametric elements. The advantages of this method are that the displacement compatibility is satisfied throughout the region and that there is no need of special crack tip elements. The stress intensity factors can be accurately obtained by using general purpose programs having isoparametric elements such as NASTRAN.

9 Ill.

Electronic Resource

0029-5981

Engineering ; Engineering General

Wiley InterScience Backfile Collection 1832-2000

Mathematics

Technology

Quadratic and cubic quadrilateral isoparametric elements are investigated for use as transition elements for use a crack tip elements. Computations for a single element are explicitly carried out using a symbolic algebraic manipulation program and in addition to the desired square root singularity, additional singularities are revealed. Cubic transitional elements were used for a double-edge crack problem and only marginal improvement is found for a well-laid out grid.

3 Ill.

Electronic Resource