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1.
1. The synthesis and release of nitric oxide may play a role in the pathogenesis of peripheral vasodilatation and hyperdynamic circulation observed in liver cirrhosis. In this work, we analysed the synthesis of nitric oxide by the lympho-mononuclear cells of peripheral blood from patients with chronic alcoholic and non-alcoholic liver disease and we identified the isoform of nitric oxide synthase involved in the increased nitric oxide synthesis. 2. Patients were classified following clinical and histological criteria in non-alcoholic cirrhotic, alcoholic cirrhotic and non-cirrhotic chronic liver disease. We studied clinical and analytical characteristics, haemodynamic parameters and endotoxin levels in these patients. 3. Cirrhotic patients showed an increase of cardiac output and a decrease of peripheral vascular resistance. These patients had higher levels of plasma endotoxin than those observed in the control group. N omega-Nitro-L-arginine methyl ester (L-NAME)-inhibitable nitrite production from mononuclear lymphocyte cells was higher in patients than in the control group, the highest levels being in non-alcoholic cirrhotic patients, and the lowest levels in patients with non-cirrhotic alcoholic liver disease. 4. Immunocytochemistry studies revealed a positive immunoreactivity for the inducible isoform of nitric oxide synthase in lympho-mononuclear cells that was more evident in non-alcoholic than in alcoholic cirrhotic patients. By Northern blot, inducible nitric oxide synthase mRNA expression was observed only in lymphomononuclear cells from non-alcoholic cirrhotic patients. 5. Our patients show a correlation between nitric oxide synthesis, endotoxin levels and haemodynamic parameters. 6. These findings indicate that lympho-mononuclear cell stimulation may play a role in elevated nitric oxide production in hepatic cirrhosis. Thus, this increased nitric oxide synthesis could be implicated in the pathogenesis of the haemodynamic disturbances frequently found in cirrhotic patients. This increase seems to be induced, at least in part, by activation of an inducible isoform of nitric oxide synthase.  相似文献   
2.
Machine learning algorithms for event detection   总被引:1,自引:0,他引:1  
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3.
In this paper we examine in detail the algorithm of Simon [H.A. Simon, Causal ordering and identifiability, in: W.C. Hood, T.C. Koopmans (Eds.), Studies in Econometric Method. Cowles Commission for Research in Economics, Monograph No. 14, John Wiley & Sons, Inc., New York, 1953, pp. 49-74, Chapter III], called the causal ordering algorithm (COA), used for constructing the “causal ordering” of a system given a complete specification of the system in terms of a set of “structural” equations that govern the variables in the system. This algorithm constructs a graphical characterization of the model in a form that we call a partial causal graph. Simon argued in [H.A. Simon, Causal ordering and identifiability, in: W.C. Hood, T.C. Koopmans (Eds.), Studies in Econometric Method. Cowles Commission for Research in Economics, Monograph No. 14, John Wiley & Sons, Inc., New York, 1953, pp. 49-74, Chapter III] and subsequent papers that a graph so generated explicates causal structure among variables in the model. We formalize this claim further by proving that any causal model based on a one-to-one correspondence between equations and variables must be consistent with the COA.  相似文献   
4.
Denver 《数码世界》2003,2(10):41-41
在国内,我们常常遇到这样的问题,随着企业规模的扩大,人员的增加,整体效率也随之降低,企业往往可以通过规章制度等方法提高员工个人的工作效率,但是如何提升群体的工作效率却一直困扰国内的企业及政府部门,造成这种情况的原因一方面是管理问题,而另外一方面是技术问题,由于中国特殊的国情,在企业管理方面远远比不上西方发达国家,于是随着今年互联网  相似文献   
5.
Polyquaternium-1 (PQ-1) and myristamidopropyl dimethylamine (MAPD) are biocides used commercially in a contact lens disinfecting solutions. Electron microscopy was used to provide further evidence on the mechanism(s) of action of these agents against a wide range of ocular pathogens including bacteria, fungi and protozoa. Both PQ-1 and MAPD caused multiple forms of damage to the organisms tested, evidenced by structural alterations, blebbing, leakage and cell destruction. The extent of damage and the selectivity against specific type of microorganisms was consistent with the antimicrobial activity of these agents. Although electron microscopy is a powerful tool, it has its limitations when used to examine the mode of action of biocides. Indeed, there was no evidence of gross structural alteration to Acanthamoeba castellani or Aspergillus fumigatus following treatment.  相似文献   
6.
An elaborate network of transmitter receptors, synapse associated proteins (SAPs), and cytoskeletal elements, generally known as the postsynaptic density, is involved with efficient synaptic signaling. The localization of the synapse associated protein SAP102 was studied in the rat retina by using immunocytochemical methods. Immunofluorescence for SAP102 was most prominent in the inner plexiform layer (IPL). It had a punctate appearance, suggesting a synaptic clustering of SAP102 in the IPL. Electron microscopy by use of pre-embedding immunocytochemistry showed that SAP102 is concentrated in the IPL in processes which are postsynaptic at bipolar cell ribbon synapses (dyads). As a rule, only one of the two postsynaptic members of the dyad was labeled for SAP102. Double-labeling experiments were performed in order to find out whether SAP102 is involved with the clustering the N-methyl-D-aspartate (NMDA) receptor 2A subunit (NR2A). Only a fraction (approximately 23%) of the SAP102 clusters expressed NR2A, suggesting SAP102 is also associated with other subunits or receptors. Distinct SAP102 labeling was also present in horizontal cell processes in the outer plexiform layer (OPL), which are inserted as lateral elements into photoreceptor ribbon synapses (triads). The optic nerve fibre layer was also diffusely immunoreactive for SAP102. The postsynaptic aggregation of SAP102 at bipolar cell dyads and at photoreceptor triads suggests SAP102 is associated with the clustering of transmitter receptors. However, the labeling of the optic nerve fibre layer indicates additional functions of SAP102 in the retina.  相似文献   
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Power generation using gas turbine (GT) power plants operating on the Brayton cycle suffers from low efficiencies, resulting in poor fuel to power conversion. A solid oxide fuel cell (SOFC) is proposed for integration into a 10-MW GT power plant, operating at 30% efficiency, in order to improve system efficiencies and economics. The SOFC system is indirectly coupled to the GT, in order to minimize the disruption to the GT operation. A thermo-economic model is developed to simulate the hybrid power plant and to optimize its performance using the method of Lagrange Multipliers. It predicts an optimized power output of 18.9 MW at 48.5% efficiency, and a breakeven per-unit energy cost of USD 4.54 ¢ kW h−1 for the hybrid system based on futuristic mass generation SOFC costs.  相似文献   
10.
Mathematical techniques are presented which allow for analytical solutions of the catalyst layer transport and electrochemical problem in PEM fuel cells. These techniques transform the volumetric reaction terms to boundary flux terms, thereby eliminating the need for computational solving of the catalyst layer problem. The result is a semi-analytical fuel cell model—a computational model that entails analytical rather than computational catalyst layer solutions. This helps to alleviate the meshing difficulties inherent in the catalyst layers caused by large geometric aspect ratios, and hence reduce the computational requirements for fuel cell models.  相似文献   
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