Insights into influence mechanism of polymeric excipients on dissolution of drug formulations: A molecular interaction-based theoretical model analysis and prediction

This study provides an analysis of the dissolution mechanism of poorly water-soluble drugs, indomethacin (IND) and naproxen (NAP), from polyvinyl acetate (PVAc) and polyvinylpyrrolidone/vinyl acetate 64 (PVPVA 64) formulations under the combination of the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) and a chemical-potential-gradient model. Moreover, the dissolution kinetics of both drugs from these polymeric formulations were modeled in conformity with the in vitro experimental data obtained by means of a rotating disk system (USP II). The combination of the thermodynamic model PC-SAFT and a chemical-potential-gradient model was demonstrated to be an efficient approach to explain the drug dissolution mechanism from the drug/PVAc and PVPVA 64 formulations. These results have implications in reducing experimental time and resources for the sustained dissolution kinetics profile determination without compromising accuracy, in particular for the system of the drug/PVAc formulation when obtaining continuous drug dissolution in this work.     

Structure-activity relationship in Sb-V-oxide catalysts for the direct synthesis of acrylonitrile from propane

The structure/composition and catalytic behavior in propane ammoxidation to acrylonitrile of Sb-V-oxides prepared by a novel precipitation—deposition method is reported and the nature of the active components in these catalysts is discussed. Results suggest that the active phase for the selective synthesis of acrylonitrile from propane is a trirutile-like V-antimonate with Sb⁵⁺-oxide supported on it. Vanadium plays a catalytic role in the selective activation of propane and reoxidation of antimony, but when present in large amounts on the surface catalyzes the unselective NH₃ → N₂ conversion with a lowering in acrylonitrile selectivity. -Sb₂O₄ is instead a side phase, with a marginal or negligible role in the catalytic behavior.     

Health assessment of artisanal gold miners in Tanzania

In 2003 UNIDO (United Nations Industrial Development Organization) conducted an environmental and health assessment in a small-scale mining area in Tanzania. BGS (British Geological Survey) performed the environmental assessment. The Institute of Forensic Medicine - University of Munich performed the health assessment. The results of the medical, neurological and neuro-psychological examination of 180 participants from the affected area of Rwamagasa and 31 controls were analyzed. Urine, blood and hair samples were analyzed to detect the level of mercury body burden. Mercury concentrations in the bio-monitors urine, blood and hair were statistically significantly higher in the exposed population from Rwamagasa compared to the control group from Katoro. Only amalgam burners showed mercury levels above the toxicological threshold limits. A speciation of mercury in hair indicated that mainly elemental mercury vapor contributed to the high body burden of the artisanal miners. 104 amalgam-burners, the most exposed population group, were examined. 25 of these workers were found to be intoxicated. Small-scale mining is a serious health hazard for amalgam burners. Reduction of the exposure is essential to prevent further damage.     

A column generation and partitioning approach for multi-commodity flow problems

Multi-commodity network flow problems, prevalent in transportation, production and communication systems, can be characterized by a set of commodities and an underlying network. The objective is to flow the commodities through the network at minimum cost without exceeding arc capacities. In this paper, we present a partitioning solution procedure for large-scale multi-commodity flow problems with many commodities, such as those encountered in the telecommunications industry. Using a cycle-based multi-commodity formulation and column generation techniques, we solve a series of reduced-size linear programs in which a large number of constraints are relaxed. Each solution to a reduced-size problem is an improved basic dual feasible solution to the original problem and, after a finite number of steps, an optimal multi-commodity flow solution is determined. Computational experience is gained in solving randomly generated test problems and message routing problems in the communications industry. The tests show that the procedure solves large-scale multi-commodity flow problems significantly faster than existing linear programming or column generation solution procedures.     

3-nitroadipate, a metabolic intermediate for mineralization of 2, 4-dinitrophenol by a new strain of a Rhodococcus species

We experienced a case of small cell carcinoma of the stomach in which chemotherapy had been markedly effective. A 54-year-old man was admitted to our hospital complaining of hematemesis. Gastric endoscopy showed a type 2 tumor at the lesser curvature of the cardia of the remnant stomach. Total gastrectomy, splenectomy and D2 lymph node dissection were performed. Histopathologically, the tumor was diagnosed as a small cell carcinoma with findings of t 2 n 1 in stage II, and conclusive curability was A. A month after the operation, CT-scan revealed multiple liver and lung metastases, so the patient was treated by combined chemotherapy with cisplatin and etoposide called PVP for three courses every four weeks for small cell lung cancer, which resulted in remarkable reduction of metastases (96% in the liver and 81% in the lung). This result suggests that PVP chemotherapy is effective in the treatment of small cell carcinoma of the stomach as well as the lung.     

为大众谋求个性化——维也纳的住宅建设

我们能把住宅看成是准确无误地实现我们愿望的一些机器吗？虽然维也纳目前的住宅建设都在通过类型学和主题设计方面试图满足各种各样需求。但同时，所谓的“实验性的”理念或投资于未尝试过事物的愿望看起来正在收缩。有人会说，越来越多的服务型住宅都在以极其低廉的成本在建造，但这不是对住宅主题进行概念研究的一个理想基础。     

Analytical Solutions for Stress Intensity Factor,T-Stress and Weight Function for the Edge-Cracked Half-Space

An analytical solution for the linear-elastic problem of an edge-cracked semi-infinite body was given already in 1957. For the numerical evaluation of this solution an iteration procedure had to be applied. This might be the reason why the related analysis was not commonly used. By means of powerful mathematical tools developed in the last years it is now possible to evaluate highly-precise stress intensity factors, T-stress terms, weight functions etc. This will be shown in this paper in detail.     

Distortion Behaviour and Mechanical Properties of AlCu4Mg1 Sheet Components after High‐Pressure Gas Quenching in Comparison to Liquid Quenching

The quenching process after solution annealing of age hardenable aluminium alloys is necessary for an improvement of the mechanical properties, but also tends to result in distortion, especially in thin or complex shaped parts, and requires a costly reworking. High‐pressure gas quenching can reduce distortion compared to liquid quenching, because of the better temperature uniformity during quenching. A determination of the distortion behaviour of different serial parts of the aluminium wrought alloy 2024cl (AlCu4Mg1,clad) points out, that high‐pressure gas quenching offers predominantly excellent values regarding the dimensional accuracy after quenching compared to liquid quenchants. In comparison to the conventional heat treatment, similar values in strength, hardness and electrical conductivity have been determined after gas quenching and aging of different aluminium alloys (2024, 6013, and 7075), Furthermore, the residual stresses have been investigated and could be clearly reduced after gas quenching.     

Grooming and coalitions in Japanese macaques (Macaca fuscata): Partner choice and the time frame reciprocation.

Evidence of a reciprocal exchange of grooming and agonistic support in primates is mixed. In this study, the authors analyzed a large database of grooming and coalitions in captive female Japanese macaques (Macaca fuscata) to investigate their within-group distribution and temporal relations. Macaques groomed preferentially those individuals that groomed them most and supported preferentially those individuals that supported them most. They also supported preferentially those individuals that groomed them most and groomed preferentially those individuals that supported them most. These results were not explained by covariation of grooming and support with third variables such as kinship, rank, or time spent in proximity. However, receiving grooming did not increase the short-term probability of supporting a partner, and being supported did not increase the short-term probability of grooming a partner. The proximate mechanisms underlying the exchange of services were discussed in relation to the time frame of the behavioral choices made by the monkeys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)