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621.
622.
The effects of intraduodenal glycerol, fatty acid (FA) chain length and FA loads, and bile acid (BA) concentrations on pancreatic and gallbladder function were investigated in 31 healthy volunteers by a perfusion method. FA absorption rates in the duodenum and proximal jejunum were measured simultaneously. Pancreatic and gallbladder responses were augmented by increasing FA chain length and FA loads until the "maximal" secretory capacity of the pancreas and gallbladder emptying was attained. Glycerol had no effect. Raising BA concentrations above the critical micellar concentration accelerated FA absorption rates but decreased the magnitude of pancreatic and gallbladder responses to FA. Higher BA concentrations exerted an opposite effect, slowing FA absorption and increasing pancreatic and gallbladder responses. Indeed, a significant, inverse correlation was found between FA absorption and pancreatic and gallbladder responses to FA, suggesting a relationship between the length of intestine exposed to FA and the amount of cholecystokinin (and/or other neurohormonal factors) released, which stimulates pancreatic secretion and gallbladder contraction.  相似文献   
623.
A standard approach for visualizing multivariate networks is to use one or more multidimensional views (for example, scatterplots) for selecting nodes by various metrics, possibly coordinated with a node-link view of the network. In this paper, we present three novel approaches for achieving a tighter integration of these views through hybrid techniques for multidimensional visualization, graph selection and layout. First, we present the FlowVizMenu, a radial menu containing a scatterplot that can be popped up transiently and manipulated with rapid, fluid gestures to select and modify the axes of its scatterplot. Second, the FlowVizMenu can be used to steer an attribute-driven layout of the network, causing certain nodes of a node-link diagram to move toward their corresponding positions in a scatterplot while others can be positioned manually or by force-directed layout. Third, we describe a novel hybrid approach that combines a scatterplot matrix (SPLOM) and parallel coordinates called the Parallel Scatterplot Matrix (P-SPLOM), which can be used to visualize and select features within the network. We also describe a novel arrangement of scatterplots called the Scatterplot Staircase (SPLOS) that requires less space than a traditional scatterplot matrix. Initial user feedback is reported.  相似文献   
624.
625.
Deep neck infection has ominous implications if not detected and treated in an early stage. The anatomic relationships of head and neck spaces encourage spread of infection. Immediate hospitalization and constant monitoring of the patient after diagnosis are mandatory.  相似文献   
626.
Accurate electrocardiographic diagnosis of myocardial ischemia or infarction is difficult in patients with the Wolff-Parkinson-White syndrome; however, myocardial ischemia may also have profound effects on the electrophysiologic characteristics of the bypass tract in these patients. Comparison of studies performed during and two months following an episode of significant myocardial ischemia demonstrated substantial prolongation of the refractoriness of the bypass tract during the period of ischemia. Bypass refractoriness was prolonged by 196 msec, yet atrioventricular nodal refractoriness was not significantly different from normal. These studies, therefore, suggest that, on occasion, the presence of acute myocardial ischemia may, in fact, obscure the electrocardiographic diagnosis of the Wolff-Parkinson-White syndrome.  相似文献   
627.
    
  相似文献   
628.
    
In a rat model of corneal transplantation, Fischer 344 (RT1(lv1)) rats received orthotopic corneal isografts or Wistar-Furth (RT1(u)) donor allografts. Rejection was observed in 25 of 26 allograft recipients, at a median time of 18 days, with all isografts surviving > 100 days. Flow cytometric analysis of aqueous humour identified cellular infiltration of the aqueous at the time of allograft rejection, in contrast to the acellular aqueous found in isografts at corresponding times following transplantation. A higher proportion of CD8+ than CD4+ cells was found at days 1-3 following rejection, whereas there was a higher proportion of CD4+ cells at days 5-8. No changes in peripheral blood T cell subsets were found at the time of rejection. Immunohistochemical analysis of cells infiltrating recipient iris and grafted cornea undertaken at days 1-2, 4 and 7-10 following onset of rejection, demonstrated inflammatory cells in the graft epithelium, stroma and aggregated on the endothelium. Large numbers of macrophages, T cells (CD4+ > CD8+ at all time points), natural killer (NK) cells and neutrophils were detected in graft tissue at days 1-2 and 4, diminishing after that time. Most infiltrating cells expressed MHC class II antigen, and a smaller number expressed IL-2R. Expression of the co-stimulatory marker B7 was identified in a few cells at day 4 in the region of the graft-host wound. The immune response in graft rejection was characterized at day 4 also by expression of intercellular adhesion molecule-1 (ICAM-1) on endothelial cells of iris and corneal vessels, demonstration of interferon-gamma on mononuclear cells in the peripheral (recipient) cornea, and tumour necrosis factor-alpha on aggregated mononuclear cells on the graft, but not recipient, endothelium. Only sparse cellular infiltrates were found in isograft controls, with inflammation located at the graft-host wound. These findings suggest that inflammatory cells reach a corneal allograft by two routes--from vessels in the peripheral recipient cornea, and from vessels in the recipient iris via the aqueous humour. Different aqueous and intragraft T cell subset proportions were seen early in rejection, although a preponderance of CD4+ cells was found in both aqueous and graft at later times.  相似文献   
629.
    
OBJECTIVES: In accordance with the NIH Revitalization Act of 1993, the National Institutes of Health and the Alcohol, Drug and Mental Health Administration require grant applicants and cooperative agreement participants to include minorities in human subject research. In an environment characterized by diminishing research dollars, this mandate has increased the pressure on investigators to determine factors that impede minority participation and to develop strategies to overcome these impediments. METHODS: An extensive review of the literature was conducted to identify the factors possibly responsible for the low participation levels of African Americans in medical research studies and to highlight areas for further research. The items examined included the historical relationship between African Americans and medical researchers and the attitudes, perceptions and beliefs of potential participants and researchers as they relate to the low representation of African Americans in medical research. RESULTS: The factors identified as possible impediments to African American participation included distrust of the medical/scientific community, poor access to primary medical care, the failure of researchers to recruit African Americans actively, the alienation of minority health professionals, lack of knowledge about clinical trials, language and cultural barriers. CONCLUSIONS: Well-designed, relevant, ethical research in conjunction with an appreciation of the many barriers to participation are paramount to increasing African American presence in clinical research.  相似文献   
630.
The retention of six polycyclic aromatic hydrocarbons (PAHs) was characterized by reversed-phase liquid chromatography. The PAHs were detected by laser-induced fluorescence at four points along an optically transparent capillary column. The profiles were characterized in space and time using an exponentially modified Gaussian equation. The resulting parameters were used to calculate the retention factors, as well as the concomitant changes in molar enthalpy and molar volume, for each PAH on monomeric (2.7 micromol/m2) and polymeric (5.4 micromol/m2) octadecylsilica. The changes in molar enthalpy become more exothermic as ring number increases and as annelation structure becomes less condensed. The changes in molar volume become more negative as ring number increases for the planar PAHs, but are positive for the nonplanar solutes. In addition, the rate constants, as well as the concomitant activation enthalpy and activation volume, are calculated for the first time. The kinetic data demonstrate that many of the PAHs exhibit very fast transitions between the mobile and stationary phases. The transition state is very high in energy, and the activation enthalpies and volumes become greater as ring number increases and as annelation structure becomes less condensed. The changes in thermodynamic and kinetic behavior are much more pronounced for the polymeric phase than for the monomeric phase.  相似文献   
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