Enterotoxin formation by Clostridium perfringens during sporulation and vegetative growth

Growth, sporulation and enterotoxin production have been followed for three different strains of Clostridium perfringens on a vegetative (FTG) medium and a sporulation (DS) medium. Enterotoxin production was followed by use of enzyme-linked immunosorbent assay (ELISA). All strains produced enterotoxin under both vegetative growth and sporulation in spite of the fact that one strain is known to be enterotoxin negative. The presumed negative strain produced about the same amount of enterotoxin on both media (1 ng/ml). The two other strains produced about 1000–2000 times more enterotoxin during sporulation than during vegetative growth.     

A strong predictor in carcinoma of the breast

A case of sustained lung fistula after lung surgery is reported here. This case of a sustained pulmonary fistula was diagnosed by sustained air leak through the chest drain and a positive culture of the drainage fluid. The third re-operation was performed successfully by omentopexy via median sternotomy. Careful postoperative observation with chest radiography, bronchial fiberscopy, and determining whether infection is present in the drainage fluid are important for precise diagnosis and therapy for complications following pulmonary lobectomy.     

Thermodynamic Calculations on the Chemical Vapor Deposition of Silicon Nitride and Silicon from Silane and Chlorinated Silanes

After a discussion of the thermochemical values of the Si–H–Cl–N system which occur in the literature, CVD phase diagrams are presented which include contours of constant deposition efficiency. The temperature range considered is from 800 to 2600 K. A number of chlorinated silanes as well as silane can be used as a silicon source, while ammonia is used as the nitrogen source. The effects of pressure variation and dilution by nitrogen and hydrogen are also included. Some initial calculations concerning silicon diimide are made. The CVD phase diagrams are used to describe several mechanisms occurring during the formation of silicon nitride from the gas phase.     

The magneto-electric effect in molten salts—1. Visualization and measurement of the magneto-electric voltage in 1-ethyl-pyridinium bromide; comparison of results in the molten salt at 130 °C and in solutions in water and ethanol

The magneto-electric effect has been studied using 1-ethyl-pyridinium bromide in both the molten state and in solution in water or ethanol. The production of stable, coloured radical cations allows one to observe their movement in the cell. From the results it is possible to establish a relationship between the magneto-electric voltage and the type and behaviour of the electrolyte, to better understand the magneto-electric effect in ionic liquid media and to explain the apparent non-reproducibility of certain results. A Lorentz force causes a deviation in the trajectory of charge carriers. This deviation in current lines produces differences in charge concentration in the cell, particularly between the measurement probes. Thus the physical significance of the observed voltage is different from that of the Hall voltage described for electronic solid conductors.     

电气绝缘油引起未投运变压器绝缘电阻不合格原因分析

以某典型案例为例,在不同温度、不同储存时间下开展了不同烃组成变压器油与固体绝缘材料的相容性试验,分析并查找了原因。     

一种雷达信号综合分选的新方法

雷达信号分选是电子对抗的关键技术。阐述了差直方图法及修正PRI变换法的工作原理及其性能,研究了一种结合SDIF直方图法和修正PRI变换法的综合分选方法,即使面对同时存在常规PRI和抖动PRI信号且有脉冲干扰(或丢失)信号环境,该方法也具有良好的分选效果。通过Matlab仿真,验证了该算法的正确性和实际应用的可行性。     

雷达导引头电磁兼容设计

运用电磁兼容理论知识,着重对雷达导引头二次电源、伺服系统和接收机的电磁兼容设计提出了一些方法和措施,使导引头不仅能满足自兼容和互兼容要求,同时能通过相应的电磁兼容试验。     

INVESTIGATION INTO THE IGNITION PROPERTY OF COAL UNDER PRESSURE

ABSTRACT

The ignition property (ignition temperature and combustion time) of coals and chars were determined at the heating rate of 7.5°/min and under pressure. Different factors have been investigated, which include particle size, total pressure, partial pressure of oxygen, macerals, preparation method and catalyst. The results show that: the ignition temperature decrease with decreasing particle size and increasing total pressure or partial pressure of oxygen; coal char prepared by lower heating rate has higher ignition temperature than that by higher heating rate; vitrinite has higher ignition temperature than fusinite, but after carbonization the situation turns opposite; addition of K⁺; and Na+ to anthracite or coal char can decrease ignition temperature and K⁺; is more effective than Na⁺;.     

Proximity,accessibility and choice: A matter of taste or condition?*

Drawing on a combination of register data and travel survey data, this research explores changes in the accessibility to different amenities for the Swedish population between 1995 and 2005, as well as the reasons behind the changes: redistribution of either amenities or the population. Overall, proximity has increased concerning most of the amenities during the period. However, despite decreasing ‘potential’ distances, actual travel distances are growing longer due to, for example, an increasing selectivity in preferences. An analysis of the accessibility development for service amenities shows that restructuring within the service sector is the main cause of the changes, and to a lesser extent population redistribution. Resumen. Haciendo uso de una combinación de datos de registros y encuestas de viajes, este estudio explora cambios en la accesibilidad de diferentes servicios y lugares de recreo para la población sueca entre 1995 y 2005, así como las razones detrás de dichos cambios: una redistribución de los servicios o de la población. En conjunto, la proximidad ha aumentado con respecto a la mayoría de los servicios durante el periodo estudiado. Sin embargo, a pesar de las reducciones en distancias “potenciales”, las distancias de viaje están aumentando debido a por ejemplo una mayor selectividad en las preferencias. Un análisis del desarrollo de la accesibilidad de servicios y ocio muestra que la reestructuración dentro del sector servicios es la causa principal de los cambios y, en menor medida, la redistribución de la población.