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101.
While low air quality may have negative effect on product quality in manufacturing, it has become a social concern as there are many reports on the result of worker exposure to low air quality. Manufacturing experienced a boom increase after World War I and II due to higher demands for products that gave birth to an unhealthy environment for workers. For example, Epidemiological investigations have linked unhealthy environment (air pollution) to adverse health effects such as respiratory diseases, and increased mortality and morbidity. These manufacturing systems represented less than 14% of the private employment and accounted for 42% of the nonfatal workplace illnesses. It is evident that manufacturing systems still have significant impact on the health of workers. Therefore, this study proposes a fuzzy Bayesian air quality monitoring model that is able to mimic human-like intelligent behavior in the environmental analysis. An illustrative example is demonstrated to present the application of the model.  相似文献   
102.
A new approach for modelling concrete spalling process is here proposed, taking into account a fully nonlinear-displacement/strain theory able to catch complex interactions between pressure, thermal and mechanical fields. The micro-structural modelling of concrete under fire conditions is derived from a mechanical and thermodynamic consistent theory and it is strictly related to a self-consistent, carefully extracted set of experimental data, in order to make a correct validation and calibration of the numerical F.E. procedures and codes. Even if appearing as a first but successful example, it is shown that a procedure accounting for coupled material and geometric nonlinearities is able to attain valuable and realistic numerical results concerning spalling process in concrete.  相似文献   
103.
In the rapid thermal processing of a semi-conductor wafer, the temperature of the latter has to follow a preset time evolution profile while keeping spatial uniformity. A model-based open loop control strategy is presented in all its steps. A global and sufficiently accurate thermal model, based on the component interaction network, is used for the prediction of the required instantaneous heat flux distribution gained by the wafer. The same model is used to calculate the distribution of the net heat flux gainedby the wafer for each radiant emitter. The optimal combination of input powers to the radiant emitters is then determined using real time dynamic programming. It consists in minimizing the maximum difference between the required heat flux distribution and the one corresponding to the tested combination of input powers at each time step. The objective function is corrected according to the preceding time step errors, in a way to avoid cumulative temperature deviation. The solution algorithm is described, step by step, and a test case is treated. The results show good temperature tracking and uniformity.  相似文献   
104.
Zearalenone (ZEA) is a mycotoxin produced by some species of Fusarium, especially by Fusarium graminearum and F. culmorum. ZEA induces hyperoestrogenic responses in mammals and can result in reproductive disorders in farm animals. In the present study, a real-time PCR (qPCR) assay has been successfully developed for the detection and quantification of Fusarium graminearum based on primers targeting the gene PKS13 involved in ZEA biosynthesis. A standard curve was developed by plotting the logarithm of known concentrations of F. graminearum DNA against the cycle threshold (Ct) value. The developed real time PCR system was also used to analyze the occurrence of zearalenone producing F. graminearum strains on maize. In this context, DNA extractions were performed from thirty-two maize samples, and subjected to real time PCR. Maize samples also were analyzed for zearalenone content by HPLC. F. graminearum DNA content (pg DNA/ mg of maize) was then plotted against ZEA content (ppb) in maize samples. The regression curve showed a positive and good correlation (R2=0.760) allowing for the estimation of the potential risk from ZEA contamination. Consequently, this work offers a quick alternative to conventional methods of ZEA quantification and mycological detection and quantification of F. graminearum in maize.  相似文献   
105.
A recent experimental study found that activation of negative body image cognitions produced urges to smoke in young women (E. N. Lopez, D. J. Drobes, J. K. Thompson, & T. H. Brandon, 2008). This study intended to replicate and extend these experimental findings by examining the role of negative affect as a mediator of the relationship between body dissatisfaction and smoking urges. Female college smokers (N = 133) were randomly assigned to a body image challenge (trying on a bathing suit) or a control condition (evaluating a purse). State levels of urge to smoke, mood, and body dissatisfaction were assessed both pre- and postmanipulation. Trying on a bathing suit increased body dissatisfaction and reported urges to smoke, particularly those urges related to reducing negative affect. Additionally, state negative affect mediated the relationship between the body image manipulation and smoking urge. This study provides additional support, through an experimental design, that situational challenges to body image influence smoking motivation and that this effect occurs, at least in part, through increases in negative affect. Theoretical and applied implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
106.
Findings from a longitudinal study are presented on the relationships between the problems and stresses resulting from Hurricane Andrew and posthurricane minor deviant behavior. The sample (N = 4,978) included Hispanic, African-American, and White non-Hispanic middle school students enrolled in Dade County, Florida public schools. Two waves of data were collected prior to the hurricane; a third was obtained approximately 6 months following the storm. Results indicated that females were likely to report higher levels of hurricane-related stress symptoms than males. After controlling for prehurricane levels of minor deviance, family support, and race/ethnicity, hurricane stress symptom level remained a significant predictor of posthurricane minor deviant behavior. The findings lend support to stress theories of social deviance.  相似文献   
107.
BACKGROUND: Hemochromatosis, which can lead to serious chronic diseases resulting from iron overload, has an estimated prevalence of 50 to 80 cases per 10000 persons. However, little population-based information is available on the impact of hemochromatosis on morbidity and mortality. OBJECTIVE: To evaluate trends over 14 years in deaths and medical conditions associated with hemochromatosis in the United States. DESIGN: We searched Multiple-Cause Mortality Files compiled by the National Center for Health Statistics for the years 1979 to 1992 for all records listing hemochromatosis. We used these data to calculate age-adjusted and age-specific mortality rates, identify medical conditions associated with a known diagnosis of hemochromatosis at death, and calculate proportionate mortality ratios for these medical conditions. RESULTS: The listing of hemochromatosis on death certificates increased 60% from 1979 to 1992. Decedents with hemochromatosis were 23, 13, and 5 times more likely to have liver neoplasms, liver disease, and cardiomyopathy, respectively, than were decedents without hemochromatosis. Conversely, decedents with liver neoplasms, liver disease, and cardiomyopathy were 26, 14, and 5 times more likely, respectively, to have hemochromatosis than were decedents without these conditions. Hemochromatosis was 82 times more likely in persons with the combination of liver neoplasms and diabetes and 43 times more likely in those with the combination of liver disease and diabetes than in those without these conditions. CONCLUSIONS: Comparison of the reported prevalence of hemochromatosis among decedents with estimates of prevalence in the general U.S. population suggests that either the penetrance or the recognition of hemochromatosis, or both, is low. Nevertheless, substantial mortality resulting from liver disease, liver neoplasms, cardiomyopathy, and a combination of liver disease and diabetes in patients with hemochromatosis argues for the improved diagnosis and treatment of hemochromatosis in persons with these conditions.  相似文献   
108.
A consistent predictor of a woman's risk for breast cancer is a family history of the disease. Most studies of family history and breast cancer have used the number of affected relatives in the family to calculate relative risk, but they have not considered the heterogeneity of the familial risk for breast cancer in a systematic way. With the use of data from a large prospective mortality study of US adults, the authors compared simple classification of family history of breast cancer (yes/no) to the method of using a quantitative family history score method, which takes into account the effects of family structure, age, and birth cohort as predictors of breast cancer mortality. After 9 years of follow-up, 1,428 cases of fatal breast cancer were observed among 453,073 women with complete information on number and age of siblings and family history. With the use of the family history score, about one-third of women with a positive family history of breast cancer were at no higher risk for breast cancer mortality than those without a family history of the disease. As a quantitative measure of relative risk for each family, family history score gave a better fit to the data, and it provided an incremental improvement of predictive accuracy of developing fatal breast cancer. Family history score can also be used as a categorical variable to stratify families. This allows researchers to focus on which risk groups would benefit from conducting further genetic analysis and to test the effects of genetic factors, environmental exposure, and gene-environment interactions on the etiology of the development of breast cancer.  相似文献   
109.
110.
BACKGROUND: Nocturnal gastric acid breakthrough, defined as intragastric pH < 4 for more than 1 h in the overnight period, is observed in up to 70% of normal subjects on proton pump inhibitors taken twice daily. The frequency of this breakthrough in patients with gastro-oesophageal reflux and accompanying oesophageal reflux during this period has not been studied. AIM: To examine the frequency of nocturnal break-through and accompanying oesophageal acid exposure in patients with gastro-oesophageal reflux treated with proton pump inhibitors twice daily. METHODS: Prolonged ambulatory pH records from 76 patients on twice daily proton pump inhibitors between January 1991 and July 1997 were analysed for the presence of nocturnal gastric acid breakthrough and accompanying oesophageal pH < 4. Studies from 31 normal subjects on twice daily proton pump inhibitors constituted the control group. RESULTS: Nocturnal gastric acid breakthrough was seen in 70% of 61 patients with gastro-oesophageal reflux, 80% of 15 patients with Barrett's oesophagus and 67% of normal controls (P=N.S.). Oesophageal acid exposure was seen in 33% of gastro-oesophageal reflux patients, 50% of Barrett's oesophagus patients and 8% of normal controls (P < 0.03). No difference was found between patients taking omeprazole or lansoprazole. CONCLUSION: Nocturnal acid breakthrough is frequently seen on proton pump inhibitors twice daily and is often accompanied by oesophageal reflux. This has important implications for medical therapy in patients with severe gastro-oesophageal reflux and Barrett's oesophagus.  相似文献   
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