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The available surgical and non-surgical therapy options for treatment of gallstone disease are presented. Conventional cholecystectomy is regarded as standard therapy of symptomatic cholecystolithiasis. Other modes of therapy may be indicated under certain circumstances, depending on the results of imaging procedures. In this context conventional X-ray examination, oral and intravenous cholecystography, sonography, computed tomography, endoscopic retrograde cholangiography/cholecystography, and magnetic resonance imaging are discussed and their influence on therapeutic decisions is explained. 相似文献
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Multiple unit delivery dosage forms of biodegradable gelatin microspheres containing the anticancer drug methotrexate (GMM) of various mean particle sizes (1–5, 5–10, and 15–20 μm) were prepared by the polymer dispersion technique and were crosslinked with glutaraldehyde. The GMM were coated with biodegradable natural polymers, namely alginate (AGMM) and chitosan (CGMM), which differ in their pH sensitivity, to obtain two different types of pH dependent delivery systems for oral delivery of methotrexate (MTX). The in vitro release profiles of MTX from AGMM and CGMM were determined in simulated gastric medium, intestinal medium, and in media simulating gastrointestinal tract conditions. The effect of the concentration of coating polymer and particle size on the release rate of MTX from both AGMM and CGMM were also studied. Both AGMM and CGMM provided controlled release of MTX following a zero-order release pattern in gastric and intestinal fluids for prolonged periods of time. The release rate of MTX decreased with an increase in concentration of the coating polymer as well as an increase in particle size of the microspheres. Both AGMM and CGMM showed good potential as pH dependent multiple unit delivery systems for the controlled release of MTX in oral administration. © 1995 John Wiley & Sons, Inc. 相似文献
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Praveen C. Ramamurthy Ashwini N. Mallya Alex Joseph William R. Harrell Richard V. Gregory 《Polymer Engineering and Science》2012,52(8):1821-1830
High molecular weight polyaniline (PANI) was synthesized by a combined procedure incorporating various synthesis methods. Temperature and open circuit potential of the reaction mixture were collected to monitor the reaction progress. The polymer is characterized by various techniques including gel permeation chromatography, dynamic light scattering, infrared spectroscopy, solid‐state nuclear magnetic resonance, and differential scanning calorimetry for elucidating the molecular architecture obtained by this method. As‐synthesized PANI was found to possess high molecular weight, reduced branching, reduced cross‐linking, and to predominantly consist of linear polymer chains. This polymer was also found to be more stable in solution form. J–V characteristics of as‐synthesized PANI films indicate a high current density which is due to increased free pathways and less traps for the charge transport to occur in PANI films. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers 相似文献
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S. Venkateswaran R. M. Mallya M. R. Seshadri 《International Journal of Cast Metals Research》2013,26(2):72-82
AbstractThe effect of trace elements, used for modification, on the cooling curves obtained during solidification, microstructure and mechanical properties of eutectic aluminium-silicon alloy was investigated. The results of this study indicate the following: 1 The addition of sodium or sodium plus strontium or antimony modifies the eutectic silicon while the addition of sulphur does not alter the microstructure. 2 Those elements which modify the eutectic-silicon, lower the eutectic solidification temperature, while those elements which do not bring about modification, do not alter the eutectic solidification temperature. 3 The addition of those elements which modify the eutectic aluminium-silicon alloy, viz., sodium or sodium plus strontium or antimony improves the UTS and percentage elongation. The addition of titanium to eutectic aluminium-silicon alloy containing these trace elements improves the UTS and percentage elongation to a further extent. Among the various trace elements added to eutectic aluminium-silicon alloy, the addition of sodium plus titanium improves the UTS and percentage elongation to the maximum extent. 相似文献
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Commitments among agents 总被引:1,自引:0,他引:1
Commitments are a powerful representation for modeling multiagent interactions. Previous approaches have considered the semantics of commitments and how to check compliance with them. However, these approaches do not capture some of the subtleties that arise in real-life applications such as e-commerce, in which contracts and institutions have implicit temporal references. In this column, we describe a rich representation for the temporal content of commitments that lets us capture realistic contracts and avoid ambiguities. Consequently, this approach lets us reason about whether, and at what point, a commitment is satisfied or breached, and whether it is or ever becomes unenforceable. 相似文献
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Rigid-ion model calculations of phonon dispersion relations, densities of states and partial densities of states of the highT
c
superconductor La2CuO4 and its isostructural compound La2NiO4 have been carried out both in the tetragonal and orthorhombic phases of La2CuO4 and the tetragonal phase of La2NiO4. The calculations are in fair agreement with reported experiments. The computed phonon dispersion in the tetragonal phase
of La2CuO4 reproduces the soft mode behaviour for the lowest Σ4 TO branch which is found to harden in the orthorhombic phase, consistent with experimental data. 相似文献
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Tommasi Tatiana Mallya Arun Plummer Bryan Lazebnik Svetlana Berg Alexander C. Berg Tamara L. 《International Journal of Computer Vision》2019,127(1):38-60
International Journal of Computer Vision - This paper presents an approach for answering fill-in-the-blank multiple choice questions from the Visual Madlibs dataset. Instead of generic and commonly... 相似文献
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K. P. Jayadevan N. V. Kumar R. M. Mallya K. T. Jacob 《Journal of Materials Science》2000,35(10):2429-2434
Oxidation of silver using microwave-induced oxygen plasma and oxygen-ozone gas mixture was studied as a function of temperature and partial pressure. The oxide Ag2O was formed at temperatures well above its normal decomposition temperature in oxygen plasma at a pressure of 5 Pa. The higher oxide AgO1–x was formed in O2+O3 gas mixtures at lower temperatures. The oxygen chemical potentials for the oxidation of Ag to Ag2O, Ag2O to AgO1–x and AgO to Ag2O3 were evaluated from thermodynamic data and compared with the experimental results to obtain information on the chemical potential of oxygen in microwave plasma and gases containing ozone. The oxygen potential of the gas phase in microwave plasma operating at a pressure of 5 Pa was found to be in excess of 36 kJ/mol at 750 K. This is equivalent to a pressure of diatomic oxygen gas greater than 3 × 107 Pa. In the O2+O3 mixture at ambient pressure containing 5 mole percent O3, the oxygen potential is 112 kJ/mol at 465 K. The equivalent pressure of diatomic oxygen is 4 × 1017 Pa. Thus, metastable species such as O3 or charged species such as O– present in plasma can be used as a powerful reagent for the syntheses of metastable oxides. Similar techniques can be used for other metastable inorganic solids such as nitrides for functional applications. 相似文献