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排序方式: 共有533条查询结果,搜索用时 15 毫秒
31.
We study the solid-fluid equilibria of hard heteronuclear dumbbells using cell theory and isobaric ensemble Monte Carlo simulations. Calculations for six cases of L* (bond length) and σ* (sphere diameter ratio) near the homonuclear limit are discussed with two base-centered monoclinic orientationally-ordered crystal structures which have been considered. The two crystal structures exhibit nearly identical properties at freezing within the accuracy of the calculations for the cases we present. The reduced pressure at coexistence increases with decreasing σ*. 相似文献
32.
Hegel Mark T.; Ayllon Teodoro; Thiel Gay; Oulton Bernadette 《Canadian Metallurgical Quarterly》1992,11(5):324
Compared a cognitive intervention and a behavioral intervention to determine their relative effectiveness in reducing interdialytic weight gain (IWG) among 8 adult male hemodialysis patients. The behavioral model consisted of positive reinforcement, shaping, and self-monitoring. The cognitive model consisted of a counseling intervention designed to modify health beliefs. In 3 studies, both interventions produced immediate reductions in IWG. However, the behavioral intervention was superior to the cognitive intervention in producing maintenance of reduced weight gain. Combining the interventions resulted in no improvement over the behavioral intervention alone. Continuation of self-monitoring procedures produced maintenance of improvements up to 2 mo posttreatment. With the exception of the barriers dimension, health beliefs did not change along with adherence behavior changes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
33.
B Carme F Gay M Ndounga MP Hayette-Gorremans JC Bouquety 《Canadian Metallurgical Quarterly》1995,46(4):270-274
OBJECTIVE: To compare body mass index (BMI), lipid, lipoprotein and apolipoprotein concentrations according to the Hind III and Pvu II restriction polymorphisms of the LPL gene in obese subjects. DESIGN: Cross sectional study of anthropometric and lipid variables in relation to genetic factors. SETTING: Nutrition Outpatient Clinic of Bichat Hospital in Paris, France. SUBJECTS: 236 unrelated patients (162 women and 74 men) were selected on the basis of 120% of ideal body weight. MAIN OUTCOME MEASURES: Anthropometry (body mass index, waist to hip ratio), blood lipids and lipoproteins, determination of LPL Hind III and Pvu II genotypes. RESULTS: Digestion with Hind III generated two alleles, H1 (absence of cutting site) and H2 (presence of cutting site), with frequencies of 0.30 and 0.70 respectively. Digestion with Pvu II generated two alleles P1 and P2 with frequencies of 0.49 and 0.51 respectively. The Hind III polymorphism was significantly associated with body mass index (BMI) (P < 0.05). The H2H2 genotype was associated with hypertriglyceridemia: 68% of the hypertriglyceridemic subjects have the H2H2 genotype vs 43% of the normotriglyceridemic group (P < 0.05). Plasma triglyceride levels varied significantly among the Hind III genotypes, H2H2 genotype having the highest total and VLDL-triglyceride levels; the Hind III polymorphism also showed a significant association with HDL2-cholesterol. These associations were only seen in women and were not explained by the variations in BMI and age. No significant associations were found between lipid traits and Pvu II genotype. CONCLUSION: These results suggest that genetic variation in the LPL gene in obese subjects is associated with hypertriglyceridemia and possibly with a predisposition to obesity. 相似文献
34.
H Ohnishi LC Samuelson DI Yule SA Ernst JA Williams 《Canadian Metallurgical Quarterly》1997,100(12):3044-3052
Rab3D, a member of the ras-related GTP-binding protein Rab family, is localized to secretory granules of various exocrine tissues such as acinar cells of the pancreas, chief cells of the stomach, and parotid and lacrimal secretory cells. To elucidate the function of Rab3D in exocytosis, we have generated transgenic mice that over-express Rab3D specifically in pancreatic acinar cells. Hemagglutinin-tagged Rab3D was localized to zymogen granules by immunohistochemistry, and was shown to be present on zymogen granule membranes by Western blotting; both results are similar to previous studies of endogenous Rab3D. Secretion measurements in isolated acinar preparations showed that overexpression of Rab3D enhanced amylase release. Amylase secretion from intact acini of transgenic mice 5 min after 10 pM cholecystokinin octapeptide (CCK) stimulation was enhanced by 160% of control. In streptolysin-O-permeabilized acini of transgenic mice, amylase secretion induced by 100 microM GTP-gamma-S was enhanced by 150%, and 10 microM Ca2+-stimulated amylase secretion was augmented by 206% of that of the control. To further elucidate Rab3D involvement in stimulus-secretion coupling, we examined the effect of CCK on the rate of GTP binding to Rab3D. Stimulation of permeabilized acini with 10 pM CCK increased the incorporation of radiolabeled GTP into HA-tagged Rab3D. These results indicate that overexpression of Rab3D enhances secretagogue-stimulated amylase secretion through both calcium and GTP pathways. We conclude that Rab3D protein on zymogen granules plays a stimulatory role in regulated amylase secretion from pancreatic acini. 相似文献
35.
Samuelson Kristin W.; Neylan Thomas C.; Metzler Thomas J.; Lenoci Maryanne; Rothlind Johannes; Henn-Haase Clare; Choucroun Gerard; Weiner Michael W.; Marmar Charles R. 《Canadian Metallurgical Quarterly》2006,20(6):716
Studies have shown differences in neuropsychological functioning between groups with posttraumatic stress disorder (PTSD) and control participants. Because individuals with PTSD often have a history of comorbid alcohol abuse, the extent to which an alcohol confound is responsible for these differences remains a concern. The current study compares neuropsychological testing scores in 4 groups of veterans with and without PTSD (PTSD+ and PTSD-, respectively) and with and without a history of alcohol abuse (ETOH+ and ETOH-, respectively): n for PTSD+/ETOH- = 30, n for PTSD+/ETOH- = 37, n for PTSD-/ETOH+ = 30, and n for PTSD-/ETOH- = 31. Results showed that PTSD, when alcohol, educational level, vocabulary, and depression are controlled for, was associated with decreased verbal memory, attention, and processing speed performance. Alcohol abuse history was associated with decreased visual memory performance. By controlling for alcohol and depression, the authors can more conclusively demonstrate that verbal memory and attention differences are associated with PTSD. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
36.
Mineralogical analysis is often used to assess the liberation properties of particles. A direct method of estimating liberation is to actually break particles and then directly obtain liberation information from applying mineralogical analysis to each size-class of the product.Another technique is to artificially apply random breakage to the feed particle sections to estimate the resultant distribution of product particle sections. This technique provides a useful alternative estimation method.Because this technique is applied to particle sections, the actual liberation properties for particles can only be estimated by applying stereological correction. A recent stereological technique has been developed that allows the discrepancy between the linear intercept composition distribution and the particle section composition distribution to be used as guide for estimating the particle composition distribution.The paper will show results validating this new technique using numerical simulation. 相似文献
37.
Alfredo Gay Neto Paulo M. Pimenta Peter Wriggers 《International journal for numerical methods in engineering》2014,97(9):683-706
This work presents a new approach to model the contact between a circular cross section beam and a flat surface. In a finite element environment, when working with beam elements in contact with surfaces, it is common to consider node or line to surface approaches for describing contact. An offset can be included in normal gap function due to beam cross section dimensions. Such a procedure can give good results in frictionless scenarios, but the friction effects are not usually properly treated. When friction plays a role (e.g., rolling problems or alternating rolling/sliding) more elaboration is necessary. It is proposed here a method that considers an offset not only in normal gap. The basic idea is to modify the classical definition of tangential gap function in order to include the effect of rigid body rotation that occurs in a rolling scenario and, furthermore, consider the moment of friction force. This paper presents the new gap function definition and also its consistent linearization for a direct implementation in a Newton‐Raphson method to solve nonlinear structural problems modeled using beam elements. The methodology can be generalized to any interaction involving elements with rotational degrees of freedom. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
38.
Tuning the Functional Properties of Polysaccharide–Protein Bio‐Based Edible Films by Chemical,Enzymatic, and Physical Cross‐Linking
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Nasreddine Benbettaïeb Jean‐Pierre Gay Thomas Karbowiak Frédéric Debeaufort 《Comprehensive Reviews in Food Science and Food Safety》2016,15(4):739-752
Among natural biopolymers, polysaccharides and proteins are very promising for biodegradable and edible wraps with different characteristics, so that their formulations can be tailor‐made to suit the needs of a specific commodity. Films prepared from polysaccharides have good gas barrier properties but exhibit lower resistance to moisture compared to protein films (edible) or polylactide films (biodegradable). Protein‐based films show better mechanical and oxygen barrier properties compared to polysaccharide films. For that reason, film performances may be enhanced by producing blend systems, where hydrocolloids (mixtures of proteins and/or polysaccharides) form a continuous and more cohesive network. However, the lower water barrier properties of hydrocolloid films and their lower mechanical strength in comparison with synthetic polymers limit their applications in food packaging. Therefore, the enhancement of biopolymer film properties has been studied to attain appropriate applications. This review provides an extensive synthesis of the improvement of the properties of edible polysaccharide–protein films by way of various chemical, enzymatic, and physical methods. These methods primarily aim at improving the mechanical resistance. They also permit to ameliorate the water and gas barrier properties and related functional properties. 相似文献
39.
40.
This second article deals with using the Comsis software for a particular application. Simulation is used to determine the maximum channel density in presence of crosstalk. In a first part, the modelling of the system is described. The simulation parameters of different optical elements are given. The results show that in the case of channels modulated at 500 Mbitls using fsk modulation format, and a direct detection operation at 1,5 μm, a minimum spacing of 6 GHz can be obtained with a 2 dB penalty. Thus if only the bandwidth of the erbium doped fibre amplifier is taken into account, the maximum number of channels which can be used is 250. However if the fsr (free spectral range) of optical filter is taken into account, the maximun number of channels is limited to 30. 相似文献