Electrochemical investigation of formic acid electro-oxidation and its crossover through a Nafion® membrane

This work studies formic acid as an anode fuel for polymer electrolyte fuel cells and investigates the electro-oxidation of formic acid on Pt/C. Fuel crossovers through the Nafion^® 115 membrane at different temperatures and concentrations are reported. A linear dependence of the crossover current on the temperature and concentration is obtained. It is found that the crossover can be reduced by five times and a higher performance can be rendered by formic acid when compared to methanol under the same conditions. Electrochemical impedance measurements are conducted to interpret the reaction mechanism of formic acid oxidation. The effect of the electrode potential on the impedance pattern is revealed and an impedance model incorporating the reaction kinetics information is developed to simulate the experimental impedance response.     

Lack of increase in time to blood culture positivity in a patient with persistent methicillin-resistant Staphylococcus aureus bacteremia predicts failure of antimicrobial therapy

Time to positivity is an available parameter in automated blood culture systems. We report a patient with persistent methicillin-resistant Staphylococcus aureus bacteremia who received various regimens for treatment of methicillin-resistant S. aureus, and demonstrate that monitoring of the time to positive blood culture might be helpful in the early recognition of treatment failure.     

In search of optimal productivity and hospital size: a case study

This study examines the relationship between optimal employee productivity and hospital size based on a sample from the state of Texas during 1982-91. Full-time equivalents (FTEs) per adjusted occupied bed is employed to represent productivity. The number of beds, total employees, and eight standard categories are used to measure hospital size. The impact of the diagnosis-related group implementation on productivity is also tested. Major findings suggest that productivity is found to be the highest for hospitals with 272 beds or 945 employees or in the category IV or V. The implementation of the DRG has not increased employee productivity.     

吸烟、饮酒与胆道癌关系的全人群病例对照研究

 目的　探讨吸烟、饮酒与胆道癌的关系。方法　采用全人群病例对照研究 ,研究对象为 1997年6月 1日～ 2 0 0 1年 5月 31日期间确诊的、年龄在 35～ 74岁的上海市区 6 2 7例胆道癌新发病例以及按性别、年龄 (5岁一组 )频数配对的 95 9例人群对照。采用非条件logistic回归模型分析吸烟、饮酒与胆道癌的关系。结果　男性中 ,吸烟对肝外胆管癌和壶腹癌各组的调整OR均大于 1,现仍吸烟者的调整OR分别为 1.5 1(95 %CI:0 .86～ 2 .6 6 ) ,1.5 8(95 %CI:0 .6 9～ 3.5 8) ;OR随吸烟年限增加和开始吸烟年龄提早有所升高 ,但均未达显著水平。饮酒对胆道癌各组OR均无统计学意义。结论　吸烟也许与肝外胆管癌、壶腹癌有联系 ,未发现吸烟与胆囊癌的显著性关联 ;未发现饮酒与胆道癌的显著性关联。     

Risk Factors for Male Breast Cancer (United States)

Objectives: The etiology of male breast cancer is obscure, although an excess risk has been associated with Klinefelter syndrome, testicular disorders, benign breast disease including gynecomastia, use of exogenous estrogens, radiation, and a family history of male or female breast cancer. We conducted a case-control study to investigate risk factors further for breast cancer in men.Methods: Based on data from the 1986 National (United States) Mortality Followback Survey (NMFS) of almost 20,000 deceased adults (age 25 years or over), we compared information obtained from next-of-kin interviews of 178 men who died of breast cancer with that of 512 male controls who died of other causes. Information was obtained on selected demographic and other factors, including diet, exercise, occupation, height and weight, and use of tobacco and alcohol.Results: Increased risks were found for men who were described by their next-of-kin as very overweight (odds ratio [OR] = 2.3, 95 percent confidence interval [CI] = 1.1-5.0). The risks associated with the three upper quartiles of body mass index (BMI) (wt/ht²) were 1.3, 1.6, and 2.3, respectively, with a significant dose-response relationship (P < 0.01). An excess risk was also associated with limited exercise (OR = 1.3, CI = 0.8-2.0). Consumption of red meat was associated with an increased risk, and consumption of fruits and vegetables with a decreased risk, although the trends were not significant. No association was found for tobacco or alcohol use, but an excess risk was associated with higher levels of socioeconomic status (SES) (OR = 1.8, CI = 1.1-3.0).Conclusions: Our study suggests that obesity increases the risk of male breast cancer, possibly through hormonal mechanisms, while dietary factors, physical activity, and SES indicators also deserve further investigation. Cancer Causes andd Control 1998, 269-275     

胆囊癌与妊娠关系的全人群病例对照研究

目的探讨胆囊癌与妊娠的关系.方法采用全人群病例对照研究,研究对象为1997年6月1日～2001年5月31日期间确诊、年龄在35～74岁的上海市区女性胆囊癌269例以及按年龄(5岁一组)频数配对的538名人群对照,采用非条件lo-gistic回归模型分析妊娠与胆囊癌的关系.结果胆囊癌合并胆石症者中,与妊娠次数≤2次者比较,妊娠次数(3次,4次,5次及≥6次)的各组调整OR分别为1.33(95%CI:0.59-2.99),1.34(95%CI:0.58-3.11),1.39(95%CI:0.57-3.43)和2.67(95%CI:1.12-6.41),趋势检验P=0.03.结论多次妊娠可能通过胆石症影响胆囊癌的发生,生育因素导致的女性体内雌、孕激素水平的升高可能在胆囊癌病因学中起一定的作用.     

身体质量指数及腰臀围比与胆道癌关系的探讨

目的:探讨身体质量指数(BMI)、腰臀围比(WHR)与胆道癌的关系.方法:采用非条件logistic回归模型分析身体质量指数、腰臀围比与胆道癌的关系.结果:与正常BMI组比较,胆囊癌女性20～29岁、30～39岁肥胖组的OR与趋势检验均达到或接近显著水平.与腰臀围比四分位最低组比较,胆囊癌和肝外胆管癌男女性最高四分位组OR和趋势检验均达到显著水平.结论:青年时期肥胖可能会增加胆囊癌的发病风险;腰臀围比也是胆囊癌和肝外胆管癌独立的危险因素.     

手术对Ⅳ期胆囊癌预后的影响

目的分析不同手术方式对Ⅳ期胆囊癌预后的影响.方法对1997年6月～2001年5月间上海市172例Ⅳ期胆囊癌病例进行临床病理分析,并对获得随访的164例的预后与手术方式的关系进行探讨.数据分析采用Kaplan-Meier法.结果 172例中未手术者44例(25.6%),手术者128例(74.4%),其中包括单纯胆囊切除术45例(35.1%)、胆囊癌根治性切除术17例(13.3%)、胆囊癌扩大根治性切除术5例(3.9%)和剖腹探查术61例(47.7%).在行根治性切除者中,Ⅳa和Ⅳb期的1年生存率分别为69.2%和40.7%,明显好于胆囊未切除或单纯切除者,在Ⅳa和Ⅳb期中各有2例存活期超过5年.结论有选择地进行Ⅳ期胆囊癌病例根治性或扩大根治性手术,有助于改善预后.     

上海市胆道癌病理形态特征的初步观察:附487例分析

目的研究上海市区居民胆道癌病理形态特征和鉴别诊断.方法自1997年6月～2001年5月在上海市区开展基于全人群的胆道癌病例-对照研究,总共收集病理切片1 228例,包括胆道癌487例(其中胆囊癌322例,肝外胆管癌105例和壶腹癌60例),胆道结石和胆囊炎对照病例721例,胆道腺瘤20例,由中、美资深病理医师复查,按世界卫生组织1991年胆囊和肝外胆管肿瘤组织学分型进行分类.结果病理标本以切除标本为主,肿瘤大小为多数小于4 cm,组织学类型中70%以上为腺癌,肿瘤组织学分级以高分化和中分化占绝大多数,TNM分期中0～Ⅱ期的胆囊癌和肝外胆管癌约占1/3,壶腹癌近2/3.病理复查结果显示诊断过头占1.8%,诊断不足占0.6%,漏诊占0.1%;随访结果显示根治术后的5年生存率:胆囊癌40.7%、肝外胆管癌11.1%和壶腹癌26.9%.结论病理复查可以统一诊断标准,提高确诊率,为全人群病例-对照研究和多学科协作积累经验.