Fluorescent Biomolecules Capped ZnSe Quantum Dots and Their Photocatalytic Activities.

The preparation of semiconductor Quantum Dots (QDs) with controllable size, shape and doping remains a biggest challenge, especially the size below 10 nm. To date, only scarce attempts have been made on the synthesis of ZnSe QDs using biomolecule-assisted hydrothermal approach. Hence the current research work examines the influence of some amino acids namely L-cysteine, methionine and tyrosine as stabilizing agents in the synthesis of ZnSe nanocrystals. The ZnSe QDs exhibited strong absorption and photoluminescence properties in the region from 200-600 nm. Spectroscopic and structural properties of the as-synthesized biomolecule-capped ZnSe QDs were characterized by UV-vis absorption spectrophotometer, FT-IR, fluorescence spectrophotometer, X-ray diffractometer, Scanning Electron Microscope and EDX analysis. The stabilizing agents have played a crucial role in preparing ZnSe QDs and in determining the photoluminescence properties. The luminescence intensity was enhanced significantly when amino-acid-capped ZnSe QDs were illuminated by UV light compared to visible light. The as-synthesised ZnSe QDs were capable of effectively degrading an organic azo dye Azophlexin, under direct sunlight irradiation and exhibited good stability during photocatalytic experiments which can be attributed to the small size of amino acid capped ZnSe. The degradation mechanism is discussed. The absorbance and FT-IR measurements confirmed the biocompatibility and water-solubility of the pure ZnSe and capped ZnSe QDs.

Increased prevalence of cardiovascular defects among 56,709 California twin pairs.

This study compared the prevalence of cardiovascular defects in twin and singleton births and explored the influences of zygosity (monozygotic and dizygotic) and maternal age (<35 and >or=35 years of age) on concordance. Data on twin and singleton infants with (n = 628 twin pairs and n = 14,078 singletons) and without (n = 53,974 twin pairs and n = 4,858,255 singletons) cardiovascular defects were obtained from the California Birth Defects Monitoring Program and the California vital statistics birth and fetal death records during the period 1983-2003. Prevalence ratios (PR) (prevalence of twin/singleton) and approximate 95% confidence intervals were calculated for 16 congenital cardiovascular categories. Poisson regression techniques using log-linear models were employed to assess whether the probability of concordance of defects within each cardiovascular category varied by zygosity or maternal age. An increased prevalence was observed in twins compared to singletons in all 16 cardiovascular categories. Seven of the cardiovascular categories had at least double the prevalence in twins compared to singletons. Like-sex twins, as a proxy of monozygosity, had an increased prevalence of cardiovascular defects compared to unlike sex twins. Probabilities of concordance for flow lesions were higher among monozygotic than dizygotic twins. Our study provides evidence that twinning is associated with more cardiovascular defects than singletons. Increased concordance for flow lesions in monozygotic twins was observed, an observation that is in agreement with findings from familial recurrence studies of cardiovascular defects.

Cohort mortality for prostatic cancer among United States nonwhites.

In recent decades, age-adjusted mortality rates from prostatic cancer have risen precipitously among blacks, remaining unchanged among whites. It is now the most common cancer among United States black males. When nonwhite mortality rates were examined by age and birth cohort, it was found that peak rates occurred at every age in the cohort of 1896 to 1900, and declined thereafter. This presages an arrest and reversal of the time trend in summary mortality rates as more recent nonwhite cohorts reach the ages of maximum risk.

Sonochemical synthesis of bismuth(III) oxide decorated reduced graphene oxide nanocomposite for detection of hormone (epinephrine) in human and rat serum.

Herein, we report an efficient electrochemical sensor strategy for determination of epinephrine based on Bi2O3 nanoparticle decorated reduced graphene oxide nanocomposite (Bi2O3@RGO). The Bi2O3@RGO was prepared by simple ultrasonic method and then it's morphological and crystal structure aspects were well characterized by physiological instruments. The electrode-electrolyte interfacial properties were examined to ensure the catalytic ability of composite sensing towards EP. The composite was deposited on the multi-conventional screen-printed electrode and was found to be desirable performance toward EP oxidation. The amperometric EP sensing exhibited good reproducible and sensitive which able to detect as low as concentration of 2.14 nM. Furthermore, good reproducibility, long-term stability and repeatability were obtained from the electrode in experiment. Moreover, the EP sensing method was successfully applied in human and rat blood serum, the recoveries were validated by HPLC method. It indicates the reliability of the method in practical analysis.

RAS mutation is associated with hyperdiploidy and parental characteristics in pediatric acute lymphoblastic leukemia.

We explored the relationship of RAS gene mutations with epidemiologic and cytogenetic factors in a case series of children with leukemia. Diagnostic bone marrow samples from 191 incident leukemia cases from the Northern California Childhood Leukemia Study were typed for NRAS and KRAS codon 12 and 13 mutations. A total of 38 cases (20%) harbored RAS mutations. Among the 142 B-cell acute lymphoblastic leukemia (ALL) cases, RAS mutations were more common among Hispanic children (P=0.11) or children born to mothers <30 years (P=0.007). Those with hyperdiploidy at diagnosis (>50 chromosomes) had the highest rates of RAS mutation (P=0.02). A multivariable model confirmed the significant associations between RAS mutation and both maternal age and hyperdiploidy. Interestingly, smoking of the father in the 3 months prior to pregnancy was reported less frequently among hyperdiploid leukemia patients than among those without hyperdiploidy (P=0.02). The data suggest that RAS and high hyperdiploidy may be cooperative genetic events to produce the leukemia subtype; and furthermore, that maternal age and paternal preconception smoking or other factors associated with these parameters are critical in the etiology of subtypes of childhood leukemia.

Spatial distribution of disease: three case studies.

Maps transformed so as to have constant density of residential population were used to analyze the spatial distribution of disease in three specific areas. Each area had received recent attention because of suspected environmental pollution. The area adjacent to the Rocky Flats Facility (CO) was examined to identify any association between possible plutonium releases and increases in lung cancer or leukemia incidence. The industrial area of northern Contra Costa County (CA) was studied to explore a relationship between petrochemical industrial emissions and histologic-specific lung cancers. Finally, a suspected increase in the risk of congenital cardiac defects possibly related to pollution of the Santa Clara County (CA) water supply was investigated. No evidence of elevated risk of disease was found to be associated with either the Rocky Flats Facility or the polluted water of Santa Clara County. An increase in lung cancer, found by other investigators in earlier years, was shown to persist in association with industrial emissions in Contra Costa County.

Brief communication: Possible increased risk of lung cancer among beauticians.

Death certificates of residents of Alameda County, California (1958-1962) with any mention of cancer were examined to determine the risk of cancer among beauticians. Twenty-four female beauticians were found among 3,460 adult females who died with cancer; four female beauticians were found in a sample of 1,000 females who died from causes other than cancer. The case and control certificates were matched for age and race. The resulting odds ratio (i.e., approximate relative risk of a cancer death) was slightly elevated (1.73) but was not statistically significant. Although a possible increase in the risk of cancer was found for several organ sites, the increase in risk for lung cancer was most striking. Analysis of pairs of death certificates, in which female controls dying of causes other than cancer were matched to female lung cancer cases for age, race, and date of death, yielded an odds ratio of 6.0. This finding suggested that the risk of lung cancer may be substantially increased among female beauticians.

Cancer incidence by marital status: U.S. Third National Cancer Survey.

Site-specific cancer incidence rates were computed by sex, age, and marital status for whites and blacks separately for ages 35-64 years with the use of population-based incidence data from the Third National Cancer Survey (1969-71) and with demographic data from the 1970 U.S. Census. Although rates were presented for all cancer sites combined and for 44 specific sites or rubrics, discussion focused on the 17 most common cancers. Within age, race, and sex groups, patterns of cancer incidence by marital status were compared by means of standardized incidence ratios, and the consistency of marital status patterns across age groups was assessed statistically. Among the most notable findings were: excess cancer rates across most sites and age groups in single black males, consistently high rates for cancer of the lung and bronchus in divorced white males and in single black females, low rates for the hormone-dependent reproductive tumors (prostate gland, breast, uterine corpus, and ovary) in separated white males and females, and high rates for cervical cancer among separated white women. Marital status patterns, where found, frequently differed between whites and blacks and between males and females.

Major histologic types of cancers of the gum and mouth, esophagus, larynx, and lung by sex and by income level.

Incidence rates by income level were computed for squamous cell carcinomas of the gum and mouth, larynx, and esophagus and for squamous cell carcinoma, small cell carcinoma, and adenocarcinoma of the lung in white males and females aged 35--64 years, with the use of data for the nine geographic areas of the Third National Cancer Survey and the 1970 U.S. census. Within sex, age, and geographic area groups, patterns of cancer incidence by income level were analyzed by use of a nonparametric statistical method. Higher rates for males than for females were found for every histologic type studied, and the ratio of male-to-female rates increased with age (especially for squamous cell carcinomas of the larynx and lung). A strong inverse relation to income level was found for all of the histologic types studied in males and for squamous cell carcinomas of the gum and mouth and esophagus and small cell carcinoma of the lung in females. These findings are discussed with reference to patterns of smoking and alcohol use by sex and social class.

Short-term treatment of actinomycosis: two cases and a review.

Recommendations for prolonged penicillin treatment of actinomycosis date from the early antibiotic era, when patients often presented with neglected, advanced disease and received interrupted therapy at suboptimal dosages. This report describes cases of esophageal and of cervicofacial actinomycosis treated successfully with short-term antibiotic therapy and reviews the literature. Many patients are cured with <6 months of antibiotic therapy. If short-term antibiotic treatment is attempted, the clinical and radiological response should be closely monitored. Cervicofacial actinomycosis is especially responsive to brief courses of antibiotic treatment.

The burden, trends, and demographics of mortality from subarachnoid hemorrhage.

OBJECTIVE: The objective of this study was to describe the recent epidemiology of mortality from subarachnoid hemorrhage in the United States. BACKGROUND: Subarachnoid hemorrhage is distinct from other forms of stroke in its risk factors, demographics, and treatment. However, it is often clustered with other stroke subtypes, obscuring its unique epidemiology. METHODS: We analyzed subarachnoid hemorrhage mortality data from the National Center for Health Statistics of the United States for the years 1979 to 1994 and compared it with other stroke subtypes. RESULTS: Age-adjusted mortality rates of subarachnoid hemorrhage were 62% greater in females than in males and 57% greater in blacks than in whites. The median age of death from subarachnoid hemorrhage was 59 years compared with 73 years for intracerebral hemorrhage and 81 years for ischemic stroke. Mortality rates of subarachnoid hemorrhage have decreased by approximately 1% per year since 1979, and the mean age of death has steadily increased from 57 years in 1979 to 60 years in 1994. Subarachnoid hemorrhage accounted for 4.4% of stroke mortality but 27.3% of all stroke-related years of potential life lost before age 65, a measure of premature mortality. The proportion of years of potential life lost due to subarachnoid hemorrhage was comparable with ischemic stroke (38.5%) and intracranial hemorrhage (34.2%). CONCLUSIONS: Subarachnoid hemorrhage is an uncommon cause of stroke mortality but occurs at a young age, producing a relatively large burden of premature mortality, comparable with ischemic stroke.

Ecologic regression analysis and the study of the influence of air quality on mortality.

This presentation focuses entirely on the use and evaluation of regression analysis applied to ecologic data as a method to study the effects of ambient air pollution on mortality rates. Using extensive national data on mortality, air quality and socio-economic status regression analyses are used to study the influence of air quality on mortality. The analytic methods and data are selected in such a way that direct comparisons can be made with other ecologic regression studies of mortality and air quality. Analyses are performed by use of two types of geographic areas, age-specific mortality of both males and females and three pollutants (total suspended particulates, sulfur dioxide and nitrogen dioxide). The overall results indicate no persuasive evidence exists of a link between air quality and general mortality levels. Additionally, a lack of consistency between the present results and previous published work is noted. Overall, it is concluded that linear regression analysis applied to nationally collected ecologic data cannot be used to usefully infer a causal relationship between air quality and mortality which is in direct contradiction to other major published studies.

A study of multiple causes of death in California: 1955 and 1980.

Multiple cause of death patterns in California for 1980 were compared to a similar study of deaths conducted in 1955. Primary underlying causes of death changed, mainly reflecting the emergence of respiratory cancer as a major cause of death in 1980. The number of causes reported per death increased from 1955 to 1980, in all age and sex groups. Diseases of the arteries and pneumonia, which are among the most common underlying causes of death, appeared more often on death certificates in both 1955 and 1980 as contributing causes than as underlying the death. Diabetes was studied in detail in the 1955 report, and comparisons were made in 1980 to show increases in the proportions of deaths with this disease and corresponding increases in its prevalence among the living population from the National Health Survey. Multiple cause of death data can provide further information on the prevalence of a fatal disease in a population and its relative role in contributing to mortality, and can also provide new information on diseases that contribute to deaths, which was not previously available in population-based studies of single cause of death.

An examination of three spatial disease clustering methodologies.

Patterns of disease in space are often analysed to determine whether a relationship exists between a disease outcome and environmental exposures. This report examines the performance of three cluster analytical methods when applied to a single data set. These methods, designed to assess the purely spatial variation of events, have been examined to assess their ability to detect clustering in an area where disease rates have previously been shown to be significantly elevated. The ability of these methods to detect spatial clustering was also examined using simulation techniques. All three methods were found to be poor at detecting spatially localized disease rates which were approximately three time the expected rate, as measured by the relative risk.

Lowered weight gain during pregnancy and risk of neural tube defects among offspring.

BACKGROUND: Maternal nutritional factors have been implicated in the complex aetiology of neural tube defects (NTD). We investigated whether the amount of weight a woman gained during pregnancy was associated with her risk of delivering an infant with an NTD. METHODS: We conducted a population-based case-control study within the cohort of 708 129 live births and fetal deaths occurring in selected California counties in 1989-1991. Face-to-face interviews were conducted with mothers of 538 (88% of eligible) NTD cases (including those electively terminated, stillborn, or liveborn) and with mothers of 539 (88%) non-malformed liveborn controls within an average of 5 months from the term delivery date. Respondent-reported weight gain during pregnancy (kg) was analysed. Risks of infants having NTD were estimated among women who gained <10 kg compared to those who gained > or =10 kg during > or =38 week gestations. RESULTS: Compared to women who gained > or =10 kg, an increased risk for NTD offspring was observed among women who gained <10 kg (odds ratio [OR] = 3.2, 95% CI : 2.3-4.6). The OR was 5.0 (95% CI : 2.6-9.7) among those women who gained <5 kg during pregnancy. The increased risk was not attributable to maternal non-use of a multivitamin containing folic acid, diabetes, NTD-pregnancy history, age, race/ethnicity, education, gravidity, alcohol use, cigarette use, prepregnant obesity, low socioeconomic status, dieting, nausea, nor to lower dietary intakes of folate, zinc, energy, protein, fat, carbohydrates, and methionine. An increased risk was observed even after simultaneous adjustment for most of these factors (OR = 2.2, 95% CI : 1.2-3.8). The risk associated with gaining <10 kg was greater for anencephaly, but still elevated for spina bifida. CONCLUSIONS: We did not have information on weight gain during early pregnancy. Because weight gain during the relevant embryological period for NTD (first month post-conception) is relatively small and often variable, it seems less likely that elevated NTD risks indicate a causal association between lowered weight gain throughout pregnancy and abnormal development of the neural tube. It seems more likely that lowered weight gain is a consequence of carrying an NTD-affected fetus. However, what this consequence is and why risk was substantially larger for anencephaly is unknown.

Description and reporting of statistical methods.

A review of the last three volumes of AJIC (1990, 1991, and 1992, numbers 1 through 3) revealed a modest use of statistics in infection control research. Discussion of the statistics most commonly used results in the following recommendations: (1) Researchers who use the t test should report the t test statistic, exact significance probabilities, and a discussion of assumptions and requirements underlying the analysis. (2) A 95% confidence interval for estimated quantities is preferred to p values. (3) The potential impact of nonresponse bias should be included in reports of survey data. (4) An adequate description of statistical methods should be included in all reports of survey data. (5) An adequate description of statistical methods should be included in all research articles.

Effects of caffeine-free diet on benign breast disease: a randomized trial.

There is considerable interest in the potential effect on benign disease of a diet free of methylxanthines (caffeine, theophylline, and theobromine) found in coffee, tea, colas, and chocolate. We randomly assigned 158 women who presented with a breast concern either to a group encouraged to abstain from methylxanthine-containing foods and beverages or to a group who received no dietary recommendations (controls). At the initial visit each patient's sociomedical history and data on methylxanthine consumption were obtained by interview, and clinically palpable breast findings were graded on a scale of 0 to 4 (no nodularity to confluent hard "dysplasia") for each quadrant of both breasts. On the follow-up visit approximately 4 months later similar information was obtained. Mammograms were taken at both visits for a subset of women in each group. We found a statistically significant reduction in clinically palpable breast findings in the abstaining group as compared with controls, but the absolute change was minor and may be of little clinical significance. Comparison of before-after mammograms offered little support for the methylxanthine hypothesis. There was no relation between clinically palpable breast finding scores at initial examination and caffeine consumption levels reported at that time.

Maternal weight gain pattern and birth weight.

OBJECTIVES: To determine the relationship between maternal weight gain pattern and birth weight. METHODS: All nonobese, white women delivered at the University of California, San Francisco, between 1980-1990 were eligible for this study. Our study group included 2994 uncomplicated pregnancies with complete data. All recorded prenatal weight gain measurements were used to estimate maternal trimester weight gain, pattern of gain (based on low versus not-low gain at each trimester), and total gain at delivery. Multiple linear regression analysis was used to assess the relationship between these weight gain measurements and fetal birth weight. RESULTS: After adjustment for seven covariates, each kilogram of maternal gain in the first, second, and third trimesters was associated with statistically significant increases in fetal birth weight of 18.0, 32.8, and 17.0 g, respectively. When compared with the pattern of gain that was not low in any trimester, patterns with low gain in the first and second trimesters or in the second and third trimesters were associated with significant decreases in birth weights of 133.0 and 88.5 g, but no important change in birth weight was seen for the group whose gains were low in the first and third trimesters. These findings were not due to differences in total weight gain, which averaged approximately 11 kg in these three pattern groups. CONCLUSION: The results suggest that specific patterns of maternal weight gain, particularly weight gain during the second trimester, are related to fetal birth weight.

Factors associated with the pattern of maternal weight gain during pregnancy.

OBJECTIVE: To examine the pattern of maternal weight gain using maternal characteristics and pregnancy outcome. METHODS: We used maternal weight data measured prospectively from all deliveries between 1980-1990 at the University of California, San Francisco. Piecewise linear regression was used to estimate the rate of maternal weight gain in each trimester. Bivariate techniques were used to examine associations between maternal weight gain per trimester and maternal characteristics and pregnancy outcomes. We also used multiple regression analysis to examine the relationship between maternal characteristics and trimester weight gain. RESULTS: Weight data for at least one trimester were available for 10,418 women. The average rate of weight gain (kg/week) was lowest during the first trimester (0.169 +/- 0.268, n = 7587), peaked during the second trimester (0.563 +/- 0.236, n = 8000), and slowed slightly in the third trimester (0.518 +/- 0.234, n = 10,052). Maternal height, hypertension, cesarean delivery, and fetal size correlated positively with the rate of gain in each trimester, but pre-pregnancy body size, age, parity, smoking status, race-ethnicity, and diabetes were associated differently with gain, depending on which trimester was examined. The most important maternal predictors of weight gain per trimester were age and Asian race-ethnicity in the first trimester; pre-pregnancy body mass, parity, and height in the second; and hypertension, age, and parity in the third. CONCLUSION: Maternal weight gain per trimester is associated with a number of maternal characteristics and pregnancy outcomes, and these relationships vary according to which trimester is being examined.

Preterm birth among African American and white women: a multilevel analysis of socioeconomic characteristics and cigarette smoking.

STUDY OBJECTIVE: Research shows that neighbourhood socioeconomic factors are associated with preterm delivery. This study examined whether cigarette smoking and individual socioeconomic factors modify the effects of neighbourhood factors on preterm delivery. DESIGN: Case-control study. SETTING: Moffit Hospital in San Francisco, California. PARTICIPANTS: 417 African American and 1244 white women, including all preterm and a random selection of term deliveries 1980-1990, excluding non-singleton pregnancies, congenital anomolies, induced deliveries, and women transported for special care. US census data from 1980 and 1990 were used to characterise the women's neighbourhoods, defined as census tracts. RESULTS: Cigarette smoking increased the risk of preterm delivery among both African American (OR=1.77, 95% confidence intervals (CI) (1.12 to 2.79)) and white women (OR=1.25, 95% CI (1.01 to 1.55)). However, cigarette smoking did not attenuate or modify the association of neighbourhood factors with preterm delivery. Among African American women, having public insurance modified the relation between neighbourhood unemployment and preterm delivery; among women without public insurance, the risk of preterm delivery was low in areas with low unemployment and high in areas with high unemployment, while among women with public insurance the risk of preterm delivery was highest at low levels of neighbourhood unemployment. CONCLUSIONS: Cigarette smoking was associated with preterm delivery, especially among African Americans. Adverse neighbourhood conditions had an influence on preterm delivery beyond that of cigarette smoking. The effects of some neighbourhood characteristics were different depending on individual socioeconomic status. Examining socioeconomic and behavioural/biological risk factors together may increase understanding of the complex causes of preterm delivery.