Showing papers by "Zhen Li published in 1999"

Interaction between poly(ethylene oxide) and sodium dodecyl sulfonate as studied by surface tension, conductivity, viscosity, electron spin resonance and nuclear magnetic resonance

Abstract: The aggregation of sodium dodecyl sulfonate (AS) in aqueous solution containing various amounts of poly(ethylene oxide) (PEO) has been investigated by different experimental techniques. The experimental techniques include surface tension, conductivity, viscosity, electron spin resonance (ESR) and nuclear magnetic resonance (NMR). The critical aggregate concentration of AS on polymer strands as well as the concentration where the polymer becomes saturated with surfactant has been determined. Both ESR and NMR results indicate that the AS–PEO complex forms a more “open” structure and that PEO may penetrate into the interior of the micelles.

[Risk factors for initiation of drug use among young males in Longchuan, Yunnan].

Abstract: OBJECTIVE To identify the risk factors for drug use among young males in Longchuan, Yunnan. METHODS A non-concurrent cohort study was carried out based on a cross-sectional survey. Demographic, behavioral, and drug-using related information were collected using an anonymous questionnaire. The non-concurrent cohort included the period January 1, 1991 to August 1, 1994. Risk factors were assessed by univariate and multivariate analysis. RESULTS The annual incidence of drug use increased between 1991 and 1993. Multivariate analysis identified the following risk factors for drug use: being born to Jingpo ethnic group (OR = 1.8, 95% C.I. 1.2-2.5), being divorced/ widowed/separated (OR = 8.9, 95% C.I. 1.8-43.3), smoking cigarettes (OR = 2.4,95% C.I. 1,6-3.8), having had pre-/extra-marital sex (OR = 1.5, 95% C.I. 1.1-2.2), having been encouraged by friends to try drugs (OR = 8.8, 95% C.I. 6.1-12.9) and having a family member who used drugs in 1991 (OR = 1.5, 95% C.I. 1.0-2.3). More than six years of education was a protective factor for drug use (OR = 0.6, 95% C.I. 0.4-0.98). The population attributable fractions were 70.8% for being encouraged by friends or others to try drugs, 50% for smoking cigarettes and 24% for being Jingpo ethnic group. CONCLUSION Results suggested that community based programs to change attitudes towards smoking cigarettes and drug use could dramatically reduce the incidence of new drug users in Longchuan County. We, therefore, recommend a community-based intervention program targeting adolescent.

Changes in the pulmonary function of factory workers exposure to terephthalic acid

Abstract: The pulmonary function was examined in 140 workers exposed to terephthalic acid(TPA) and 70 controls in the same residence area as non-exposure workers. The exposed workers exhibited significant decrease in MVV, PEFR, V75, PEFR/H and V75/H(P < 0.05) in comparison with the controls. The decrease was found to be associated with increased TPA concentration by multiple regression analysis. The results of life table method analysis suggested that there was an exposure level-response relationship between accumulative TAP dust exposure and lower FEV1. According to the results reported here, an exposure limit for TPA dust was proposed to be 4.30 mg/m3.

[Prevalence study of congenital heart disease in children aged 0-2 in Zhejiang Province].

Abstract: OBJECTIVE To find out the prevalence rate of Congenital Heart Disease (CHD) among infants and toddlers. METHODS Heart auscultation and echocardiography examination on children aged 0-2 were examined in 13 cities (or counties) in Zhejing province. RESULTS Findings showed that the prevalence rate in children aged 0-2 was 3.72/1000. The prevalence rates of CHD were quite different among age groups with the highest (5.54/1000) in age group 0, followed by 3.36/1000 in age group 1 and lowest (2.66/1000) in age group 2. No significant difference of prevalence rates was found between different sex. Ventricular septal defects (59.4%) was noticed as the most common lesion. CONCLUSION The evidence indicated that CHD is one of the most important problems of public health in China. Preventing its occurrence by conducting CHD surveillance and its etiologic research will have great significance for enhancing the qualities of life of children.

Study on seroprevalence of Helicobacter pylori infection among upper digestive tract cancer patients and their kindreds

Abstract: OBJECTIVE In order to analyse the association between Hp infection and the risk of upper-digestive tract cancer. METHODS In Huaian and Pizhou cities, Jiangsu province, Hp IgG quantitative-enzyme-immunoassay methods was used to identify IgG to H.pylori in the serum of 312 cases of upper-digestive tract cancer patients and their kindreds. RESULTS (1) The level of IgG to H. pylori and the IgG positive rate (50.0%) in gastric cancer patients were both higher than that of cardia and esophageal cancer patients (P > 0.05, chi 2 test) but no significant differences were observed between cardia and esophageal cancer patients, 3 types of cancer patients and their kindreds; (2) the overall positive rates of both patients and kindreds in gastric cancer families (27.1%) were significantly higher than that of cardia or esophageal cancer families (P < 0.05) but no significant differences were observed between cardia and esophageal groups. CONCLUSION H.pylori infection was not thought to be correlated with the development of gastric cancer, although higher clustering of Hp infection in families afflicted with gastric cancer was noticed.

Investigation on the contamination of Listeria monocytogenes in seven kinds of foods

Abstract: An examination on 3746 samples of 7 kinds of foods from 12 provinces of China for the detection of Listeria monocytogenes (LM) was carried out in 1996-1997. The detected rates of LM in commercial cold drinks, raw meat, sterilized milk products, cooked meat products, raw milk and aquatic products were 1.39%, 1.53%, 0.52%, 0.47%, 0.72% and 0.19% respectively. The result showed that LM present in the contaminated foods in a potential hazardous factor of foodborne disease.