晶界对低压电解电容器铝箔腐蚀结构的影响

采用扫描电子显微镜和背散射电子取向成像技术分析研究了低压电解电容器用阳极铝箔的腐蚀结构、晶粒尺寸和晶界分布对比电容的影响及相关机理.结果表明,在铝箔的晶界附近,尤其是大角度晶界附近容易出现尺寸较大的腐蚀孔坑或沟道,造成腐蚀结构的不均匀性并降低比电容.该晶界优先腐蚀的现象起因于晶界的高缺陷密度和与之相应的腐蚀电流密度的局部集中.增加晶界密度可以降低杂质原子偏聚程度和电流密度分布的不均匀性,因此在一些特定的电化学腐蚀条件下可以借助减小晶粒尺寸的方式提高比电容.     

圆锯片综合特性检测系统的硬件设计

圆锯片综合特性检测系统是根据国内外学者的圆锯片适张研究成果和频谱分析、坐标映射的理论,综合计算机技术、传感器技术、信号调理技术和数据采集处理技术来开发的,检测系统软件是Visual C 开发,在Win32环境下运行.整个检测系统操作简便、人机界面友好、具有较强数据管理功能,能在工业现场条件下快速、准确、无损地检测圆锯片适张状态.     

The biological properties of Aerococcus antagonists, representatives of human microbiocenoses

The paper deals with the data on biology of Aerococcus, a slightly studied group of microorganisms. Physiological-biochemical properties of Aerococcus are described, data of their distribution in nature are given. Peculiar attention is paid to the estimate of the role of Aerococcus in human microbiocenoses. As a result of the profound and all-round study of this group of microorganisms the authors have developed new bacterial drug "A-bakterin" based on the aerococcus strain. Data presented about the results of clinical tests of "A-bakterin" are presented, a possibility to use Aerococcus lysate in the elaboration of new drugs is discussed.     

Recent advances in amperometric glucose biosensors for in vivo monitoring

The substance-use, positive health practices, diet and eating habits, driving behaviours and preventive health care practices of 113 nurses living in the southeast of England were assessed by means of a postal questionnaire. Females were generally more compliant than males with most of the behaviours assessed. Females reported taking greater risks with driving behaviours by an occasional tendency to "drink and drive". Many males reported both a lack of knowledge of how to self-examine their testicles for signs of cancer and little compliance with this behaviour. This sample reported more smoking and alcohol use than previously reported samples of American nurses and U.K. norms. The nurses in this sample were more likely to avoid foods high in cholesterol, add fibre to their diet and be more vigilant in their driving behaviour than American nurses and British non-nurses.     

Clinical and epidemiological findings during a measles outbreak occurring in a population with a high vaccination coverage

Malignant mesothelioma is caused almost exclusively by occupational exposure to asbestos. During the past few years, however, increasing evidence has mounted that background exposure to asbestos could be sufficient to cause mesothelioma. Treatment of malignant mesothelioma remains a big problem. Some new approaches are on their way, and the most exciting ones are local immunotherapy in very early cases. Some success has been reported with local interferon treatment. As for treatment of metastatic pleural disease, the main purpose is symptomatic relief of dyspnea caused by fluid accumulation. The best way to achieve a lasting palliation is pleurodesis, and the most common way to do this, is by chemical means. The drug of choice in the United States has for many years been tetracycline, but since injectable tetracycline is no longer available, some substitute must be found. The substance that will "win" is not yet clear, but the two leading contestants are talc and doxycycline. Bleomycin also has its supporters, and a dark horse is quinacrine, which although not easily available in the United States, has been used in many European centers for decades.     

Anaplastic large cell lymphoma Hodgkin's-like: a randomized trial of ABVD versus MACOP-B with and without radiation therapy

During the last few years, morphological, immunohistochemical, and genetic findings have placed anaplastic large cell lymphoma (ALCL) as a distinct clinicopathologic entity, and several reports have focused on the existence of different subtypes of the tumor. Particular attention has been paid to the ALCL-Hodgkin's-like (HL) subtype, which seems to be on the border between Hodgkin's disease (HD) and high-grade non-Hodgkin's lymphoma (HG-NHL). From September 1994 to July 1997, during the course of an Italian multicentric trial, 40 ALCL-HLs were randomized to receive as front-line chemotherapy MACOP-B (methotrexate with leucovorin, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin-a third-generation HG-NHL regimen) or ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine-a scheme specific for HD). All patients with bulky disease in the mediastinum at diagnosis underwent local radiotherapy after the chemotherapeutic program. Complete response (CR) was achieved in 17 of the 19 (90%) patients who were treated with MACOP-B, and in 19 of the 21 (91%) patients who were administered ABVD. The probability of relapse-free survival, projected at 32 months, was 94% for the MACOP-B subset and 91% for the ABVD subset. The majority of patients with mediastinal bulky disease obtained CR (evaluated with 67Ga single photon emission computed tomography [SPECT]) after their radiotherapy. The present study suggests that ALCL-HL, in line with its borderline status, responds in an equivalent way to third-generation chemotherapy for HG-NHL and to conventional HD treatment in terms of both CR and relapse-free survival rates. However, as to the latter, a longer follow-up period may be needed before stating the absolute equivalence of the two regimens used.     

UV resonance Raman-selective amide vibrational enhancement: quantitative methodology for determining protein secondary structure

We have directly determined the amide band resonance Raman spectra of the "average" pure alpha-helix, beta-sheet, and unordered secondary structures by exciting within the amide pi-->pi* transitions at 206.5 nm. The Raman spectra are dominated by the amide bands of the peptide backbone. We have empirically determined the average pure alpha-helix, beta-sheet, and unordered resonance Raman spectra from the amide resonance Raman spectra of 13 proteins with well-known X-ray crystal structures. We demonstrate that we can simultaneously utilize the amide I, II, and III bands and the Calpha-H amide bending vibrations of these average secondary structure spectra to directly determine protein secondary structure. The UV Raman method appears to be complementary, and in some cases superior, to the existing methods, such as CD, VCD, and absorption spectroscopy. In addition, the spectra are immune to the light-scattering artifacts that plague CD, VCD, and IR absorption measurements. Thus, it will be possible to examine proteins in micelles and other scattering media.     

Exploring the genetic and environmental etiology of high general cognitive ability in fourteen- to thirty-six-month-old twins

Two definitions of normality ("isolated" or "correlated") are considered. The boundaries of "isolated" normality were determined by a statistical procedure, whereas the "correlated" approach was related to a clinical or predictive definition. In the latter case, the biological variations were considered abnormal if they implied a hazard with some significant future ailment as a risk factor. In this pragmatic approach, the upper limit of normal/abnormal variations is the point beyond which medical strategy is related to the most expected benefit when applied to a definite population or to an individual patient. The capacity of a diagnostic test to discriminate between patients with a defined risk and those without risk depends strictly on the value of the parameter chosen. In medical care for the prevention of vascular complications in diabetic patients or with foetal risks in pregnant women, the limits of the so-called normal range of glycaemia and other parameters should be determined according to the objective of the preventive and/or therapeutic measures to be prescribed.     

Cancer pain management in developing countries: a mosaic of complex issues resulting in inadequate analgesia

OBJECTIVE: To determine the prevalence of suicidal ideation and the symptomatic profile as well as to identify the sociodemographic characteristics highlighting female adolescents with the highest scores on suicidal ideation in adolescents living in Mexico City: students and suicidal patients. MATERIAL AND METHODS: A cross-sectional and ex-post-facto study was carried out in order to analyze information from two samples: 1,712 junior and junior high school women students (representative student sample in Mexico City), and 30 adolescents inpatient hospitalized for her suicide attempts (clinical sample). RESULTS: Prevalence of presence as well as persistence of suicidal ideation were higher in the clinical sample, nevertheless 11.8% of the school sample had everyone of the symptoms in a range of 1 to 7 days. The most persistent of the ideation symptoms was: "My family would be better if I were dead"; and in the clinical sample it was "I thought about killing myself". Finally, the sociodemographic characteristics that best matched the student girls having the highest scores in suicidal ideation were: to be on junior high school, to get low grades, to acknowledge school performance as bad and to have interrupted her studies. The characteristics that highlight the girls with a first attempt were analyzed in the clinic sample in comparison with those ones with two or more attempts. It was significant that girls in the second group were living only with one parent and they thought in the last attempt that their dead would be possible or certain. CONCLUSIONS: The prevalence of suicidal ideation was important in the school sample. If it is considered that this psychological construct has a strong association with suicidal attempt, and multiple suicide conduct, then is a priority to detect adolescents in risk and to make preventive efforts, considering the sociodemographic characteristics that configurate in risk for suicidal ideation.