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1.
There are evidence indicating that endoscopic retrograde cholangiopancreatography with sphincterotomy (ERCP+S) reduces the rate of complications in patients with severe acute biliary pancreatitis (ABP). The aim of this study was to analyze our experience in the treatment of severe ABP with ERCP+S and compare the evolution of the patients treated early (3 days or less following admission) with those treated late (after the 3rd day). A retrospective review of the clinical histories of the 16 patients with severe ABP treated with ERCP+S over the last two years is presented, analyzing their clinical features on admission and evolution. Biliary stones or biliary sludge was observed in 11 cases (69%). Nine patients had undergone early, and 7 late, ERCP+S. The patients of the latter group presented a greater number of complications during evolution than the former group (43% vs 0%; p = 0.025). The mortality of the patients of the late ERCP+S was also greater although without statistical significance (28.6% vs 0%; p = 0.15). No complication secondary to ERCP+S was detected. These findings confirm the fact that ERCP+S performed early in severe ABP significantly reduces the number of complications and is associated with a lower mortality.  相似文献   
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3.
The removal of nickel ions from dilute solutions using a process that combines an ion-exchange bed with electrodialysis has been studied. The main aspects include: the concentration of nickel ions in the diluate, the voltage over the cell and the current density distribution along the ion-exchange bed. The current density distribution provides insight into the state of the bed as it is simultaneously loaded with Ni2+ and regenerated with an electric potential difference applied perpendicular to it. A simple model is used to describe the state of the bed and the quantity of nickel removed from it as a function of time. Under specific conditions the precipitation of metal hydroxides is observed in the compartment containing the ion-exchange bed. The results show that hydroxide precipitation is related to the nickel concentration in solution and the electric potential gradient across the bed.  相似文献   
4.
Experiments on white rats proved that the silicotic pulmonary changes slowed with the tails periodically immersed into iodine solution. Those pulmonary changes were due to inhalation of quartzite dust and especially due to intratracheal administration of standardized quartz dust DQ12. Influenced by inhalation of dust containing quartz, the rats demonstrated characteristic alterations in cytologic features of bronchial and alveolar lavage water. The "iodine baths" also declined those alterations, that may prove higher resistance of pulmonary macrophages to cytotoxic effects of quartz. This hypothesis finds a support in experiments with culture of rat peritoneal macrophages. If incubated in a medium with low iodine concentrations and subsequently washed off, the macrophages demonstrate lower incidence of cytotoxic effects due to the next incubation with particles of DQ12. The macrophage's higher resistance against cytotoxic agents is believed to result directly in antisilicotic effect of iodine, so "iodine baths" could be recommended for pathogenetic therapy and medical prophylaxis of silicosis.  相似文献   
5.
The Gaussian scale-space paradigm and the multiscale local jet   总被引:3,自引:3,他引:0  
A representation of local image structure is proposed which takes into account both the image's spatial structure at a given location, as well as its deep structure, that is, its local behaviour as a function of scale or resolution (scale-space). This is of interest for several low-level image tasks. The proposed basis of scale-space, for example, enables a precise local study of interactions of neighbouring image intensities in the course of the blurring process. It also provides an extrapolation scheme for local image data, obtained at a given spatial location and resolution, to a finite scale-space neighbourhood. This is especially useful for the determination of sampling rates and for interpolation algorithms in a multilocal context. Another, particularly straightforward application is image enhancement or deblurring, which is an instance of data extrapolation in the high-resolution direction.A potentially interesting feature of the proposed local image parametrisation is that it captures a trade-off between spatial and scale extrapolations from a given interior point that do not exceed a given tolerance. This (rade-off suggests the possibility of a fairly coarse scale sampling at the expense of a dense spatial sampling large relative spatial overlap of scale-space kernels).The central concept developed in this paper is an equivalence class called the multiscale local jet, which is a hierarchical, local characterisation of the image in a full scale-space neighbourhood. For this local jet, a basis of fundamental polynomials is constructed that captures the scale-space paradigm at the local level up to any given order.  相似文献   
6.
The animation environment Jeliot automates visualization of algorithms over the Internet. The user can visualize algorithms of his own, not merely the selection supplied by a service provider. Jeliot is based on self-animating data types: the user selects the data objects of the source code to be visualized, and Jeliot produces the animation based on operations performed on those types. We present the design of Jeliot and the principles of its implementation. In addition, we discuss the educational applications of Jeliot.  相似文献   
7.
This paper presents an agent-based model of an organization. The model is made of a social network—composed of the different organization workers—and a knowledge network. Workers are assigned tasks, for which they have to use information in the knowledge network. We have modeled the quality of the information by assigning each information item a probability of being wrong. Agents can interact with other agents, who can recommend to them new information items in the knowledge network for the task to be performed. Workers are assigned different information-seeking behavior (passive, active, and learning), governing the way in which they interact with each other. Moreover, indirect interaction is also possible, as a publicly accessible knowledge base contains each agent's preferred information items.

The model was implemented in SDML, and its simulation shows that agents quickly learn to discern the better information items for the given task. However, group formation (agents' collaborating by exchanging information) takes longer to stabilize. Additionally, when the quality of items is changed, agents can quickly select the better new knowledge items, and organization performance improves again to a maximum that is only randomly disturbed.  相似文献   
8.
The road surface is one of the most important factors that have influence on the current traffic noise. Usually, for dense surfaces, impacts of the tyre on the pavement generate vibrations which are the dominant mechanisms in the tyre–road noise. In this study, the effect of muffling these vibrations, by the incorporation of crumb rubber (CR) from wasted tyres into asphalt pavements, has been evaluated acoustically. Close proximity measurements have been carried out to register the sound emission generated in the contact zone between a reference tyre and an experimental asphalt pavement with CR. The analysis of the measurements indicates that the incorporation of CR as well as the air voids content has less influence than the macrotexture of the road surface on the acoustical behaviour of this experimental asphalt pavement.  相似文献   
9.
The removal of nickel ions from a low cross-linked ion-exchange resin using an applied electrical potential gradient was studied. The potential gradient across a bed of ion-exchange particles, in which nickel ions were absorbed, was varied by two methods. One involved a change of cell voltage across beds of constant width, the other a change of bed width at constant cell voltage. In this way, various characteristics concerning the electrodialytic regeneration of a bed of ion-exchange particles in the nickel form were ascertained. The diffusion coefficient, current efficiency and migration rate of nickel in the bed are discussed. It is shown that the current efficiency for the removal of nickel is nearly one hundred percent when the bed is in the nickel form, and that the rate of regeneration is proportional to the cell voltage.  相似文献   
10.
BACKGROUND: Previous studies in rats have demonstrated that anemia induces a significant increment in gastric mucosal blood flow. In the present study, we investigated whether chronic anemia induces similar changes in gastric blood perfusion in humans, and if this effect is also present in cirrhotic patients in whom gastric blood flow is usually increased in basal conditions. METHODS: Gastric mucosal blood perfusion was assessed by means of laser-Doppler flowmetry and reflectance spectrophotometry applied through the endoscope. RESULTS: Anemia significantly increases laser-Doppler signal in cirrhotic (2.3 +/- 0.11 vs 2.9 +/- 0.22 volts, p < 0.05) and noncirrhotic patients (1.71 +/- 0.15 vs 2.24 +/- 0.17, p < 0.05). In anemic patients the index of hemoglobin concentration of the gastric mucosa, assessed by reflectance spectrophotometry, was significantly decreased in cirrhotic patients (107.6 +/- 4.7 vs 95.5 +/- 3.3, p < 0.05) and noncirrhotic patients (93.9 +/- 4.1 vs 76.1 +/- 4.2, p < 0.01), whereas the index of oxygen saturation was increased (36.7 +/- 0.7 vs 40.4 +/- 1.4, p = 0.05; and 36.4 +/- 1.1 vs 43.2 +/- 1.9, p < 0.01, respectively). CONCLUSIONS: In conclusion, chronic anemia is associated with an enhanced gastric blood perfusion reflected by an increased laser-doppler signal and gastric mucosal oxygen index despite a decrease in gastric hemoglobin concentration. In cirrhotic patients, anemia promotes a further increment in its basal gastric hyperemia.  相似文献   
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