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1.
Gastrointestinal symptoms are often encountered in patients with diabetes mellitus. Symptoms may arise in any region of the alimentary tract; common symptoms are heartburn, nausea, vomiting, diarrhea, constipation, fecal incontinence, and abdominal pain. This article reviews practical approaches to the identification of the pathophysiologic mechanisms involved in diabetic enteropathies and their complications and briefly outlines strategies to treat these symptoms. Particular emphasis is placed on applied physiologic tests and the choice of pharmacotherapy (e.g., cisapride, erythromycin, or octeotide). The current role of pancreatic transplantations also is briefly reviewed.  相似文献   
2.
Molecular analysis of cellulose biosynthesis in Arabidopsis   总被引:1,自引:0,他引:1  
Cellulose, an abundant, crystalline polysaccharide, is central to plant morphogenesis and to many industries. Chemical and ultrastructural analyses together with map-based cloning indicate that the RSW1 locus of Arabidopsis encodes the catalytic subunit of cellulose synthase. The cloned gene complements the rsw1 mutant whose temperature-sensitive allele is changed in one amino acid. The mutant allele causes a specific reduction in cellulose synthesis, accumulation of noncrystalline beta-1,4-glucan, disassembly of cellulose synthase, and widespread morphological abnormalities. Microfibril crystallization may require proper assembly of the RSW1 gene product into synthase complexes whereas glucan biosynthesis per se does not.  相似文献   
3.
This paper proposes two novel dual adaptive neural control schemes for the dynamic control of nonholonomic mobile robots. The two schemes are developed in discrete time, and the robot's nonlinear dynamic functions are assumed to be unknown. Gaussian radial basis function and sigmoidal multilayer perceptron neural networks are used for function approximation. In each scheme, the unknown network parameters are estimated stochastically in real time, and no preliminary offline neural network training is used. In contrast to other adaptive techniques hitherto proposed in the literature on mobile robots, the dual control laws presented in this paper do not rely on the heuristic certainty equivalence property but account for the uncertainty in the estimates. This results in a major improvement in tracking performance, despite the plant uncertainty and unmodeled dynamics. Monte Carlo simulation and statistical hypothesis testing are used to illustrate the effectiveness of the two proposed stochastic controllers as applied to the trajectory-tracking problem of a differentially driven wheeled mobile robot.  相似文献   
4.
Microsystem Technologies - The maximum scan angle amplitude of resonating micro-mirrors, intended for micro-projection display applications is limited by air damping. Three-dimensional transient...  相似文献   
5.
Carbon fiber-reinforced polymer (CFRP) materials are widely applied in various areas as key structure components. The structural health monitoring of the CFRP components is crucial to prevent catastrophic failure. However, the nonplane surfaces of CFRP components hinder the attaching of monitoring sensors with hard substrates. Therefore, the substrate conditions for sensor preparation are mainly considered in this study. To adapt the proposed sensors to the curved substrate, including nondevelopable surfaces, electrospinning method is used to prepare conformal piezoresistive fiber films, in which polymethyl methacrylate is served as the matrix and carbon nanotubes are utilized as the conductive filler. The piezoresistive fibers covered on CFRP substrates have a gauge factor up to 207.95 and can response to the strain less than 0.05%. Moreover, the sensor also has high durability and the ability to follow the dynamic excitation signals with as high as 50 Hz.  相似文献   
6.
A novel fluorescent probe, 3-(acetylamino)-6-aminoacridine (AA-Ac), has been synthesized and its applicability to the analysis of picomole levels of N-linked glycans investigated. AA-Ac was found to be an excellent derivatization reagent for N-linked glycans, giving at least twice the intensity of fluorescence as its predecessor 2-aminoacridone. AA-Ac-labeled glycans were analyzed by both normal and reversed-phase HPLC. They were also amenable to enzymatic sequencing and analysis by MALDI-TOF mass spectrometry, free zone capillary electrophoresis, and capillary electrophoresis/electrospray ionization mass spectrometry.  相似文献   
7.
The distribution of renin in two cases of segmental renal hypoplasia was investigated by immunofluorescence and the peroxidase anti-peroxidase (PAP) method using an anti-human renin antiserum. Renin-containing cells were found only in hypoplasic segments in the vicinity of altered glomeruli and small arteries. Well-preserved renal cortex and areas of chronic atrophic pyelonephritis failed to show any demonstrable site of renin production. Whatever is the mechanism of the disease, the characterization of large numbers of renin-containing cells in the affected kidney support a role for the renin-angiotensin system stimulation in this form of hypertension.  相似文献   
8.
Although survey results seem to indicate an abundant interest among Canadian psychology graduate students in pursuing training in criminal justice psychology, the recruitment and retention of psychologists in the Correctional Service of Canada (CSC) has been of some concern. The present study is a 2008 survey of sites within CSC that provide opportunities for clinical psychology training with offender clientele. Survey findings demonstrated that a broad range of clinical psychology training opportunities were available across 16 sites. The most frequently cited barrier to providing training was lack of time by prospective trainers, and sites reported retaining relatively few of their trainees for subsequent psychologist positions. Information was also obtained regarding vacant psychologist positions across CSC regions. In light of survey findings, substantive discussion is devoted toward the issues of psychologist recruitment and retention in Canadian federal corrections, including a discussion of both potential and existing training initiatives. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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