134 research outputs found

    Association of prenatal perchlorate, thiocyanate, and nitrate exposure with neonatal size and gestational age

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    BACKGROUND: Perchlorate and similar anions compete with iodine for uptake into the thyroid by the sodium iodide symporter (NIS). This may restrict fetal growth via impaired thyroid hormone production. METHODS: We collected urine samples from 107 pregnant women and used linear regression to estimate differences in newborn size and gestational age associated with increases in perchlorate, thiocyanate, nitrate, and perchlorate equivalence concentrations (PEC; measure of total NIS inhibitor exposure). RESULTS: NIS inhibitor concentrations were not associated with newborn weight, length, or gestational age. Each 2.62ng/mug creatinine increase in perchlorate was associated with smaller head circumference (0.32cm; 95% CI: -0.66, 0.01), but each 3.38ng/mug increase in PEC was associated with larger head circumference (0.48cm; -0.01, 0.97). CONCLUSIONS: These anions may have effects on fetal development (e.g. neurocognitive) that are not reflected in gross measures. Future research should focus on other abnormalities in neonates exposed to NIS inhibitors

    Reciprocal space mapping and single-crystal scattering rods

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    Comparative analysis between condom use clusters and risk behaviours among portuguese university students

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    The research on condom use has been focused on high-risk individuals, paying less attention to those who have moderate risk or safe sexual conducts. In order to design accurate interventions, potential differences among the condom use behavior groups must be considered. The goal was to assess possible differences in individuals presenting different types of risk behavior. 140 heterosexual university students answered a self-reported questionnaire about their sexual history, condom use habits, sexual self-esteem, sexual satisfaction, sexual control, attitudes towards condoms, self-efficacy to condom use, and emotions and feelings during sexual intercourse. A cluster analysis was conducted using the results about condom use and risk behaviors. Three groups with different risk levels emerged, presenting differences over sexual self-efficacy, attitudes towards condoms, socio-demographic variables, and sexual history. The results suggest the condom use inconsistency is highly associated with other risk behaviors but the contrary does not necessarily happens. Condom use consistent users also presented risk behaviors as smoking and drinking. The group differences suggest the risks were more affected by the combination of lack of skills with a negative attitude toward condoms than by contextual or personal variables. These differences sustain the need of an intervention adjusted to the individual's risk levels, since they differ on skills and beliefs that may hinder or promote the adoption of health behaviors.Foundation for Science and Technology/Fundacao para a Ciencia e Tecnologia (Portugal)info:eu-repo/semantics/publishedVersio

    Urinary biomarkers of exposure to insecticides, herbicides, and one insect repellent among pregnant women in Puerto Rico

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    Abstract Background There are potential adverse health risks to the mother and fetus from exposure to pesticides. Thus, studies of exposure to pesticides among pregnant women are of interest as they will assist with understanding the potential burden of exposure globally, identifying sources of exposure, and designing epidemiology studies. Methods We measured urinary concentrations of the insect repellent N-N-diethyl-meta-toluamide (DEET) and two of its metabolites [3-diethyl-carbamoyl benzoic acid (DCBA) and N,N-diethyl-3-hydroxymethylbenzamide (DHMB)], four pyrethroid insecticide metabolites [4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA); 3-phenoxybenzoic acid (3-PBA); trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (trans-DCCA); and cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DBCA)], and two chlorophenoxy herbicides [2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)] in 54 pregnant women from Puerto Rico at three separate time points (20 ± 2 weeks, 24 ± 2 weeks, and 28 ± 2 weeks of gestation). We calculated the distributions of the biomarker concentrations and compared them to those of women of reproductive age from the general U.S. population where available, and estimated the within-subject temporal variability of these repeated measurements. We also collected questionnaire data on demographics, consumption of select fruits, vegetables, and legumes in the past 48-hr, and pest-related issues, and associations between these variables and biomarker concentrations were examined. Results We found that 95th percentile urinary concentrations of DEET, 3-PBA, trans-DCCA, and 2,4-D were lower than women of reproductive age on the U.S. mainland, whereas 95th percentile urinary concentrations of 4-F-3-PBA, cis-DBCA, and 2,4,5-T were similar. DCBA, the only urinary biomarker detected in >50% of the samples, showed fair to good reproducibility across pregnancy (intraclass correlation coefficient: 0.60). Women were more likely (p <0.05) to have greater urinary concentrations of pesticide biomarkers if they were less educated (DCBA and trans-DCCA), unemployed (DHMB), or married (2,4-D), had consumed collards or spinach in past 48-hr (2,4-D) or had been using insect repellent since becoming pregnant (DCBA), or were involved with residential applications of pesticides (trans-DCCA). Conclusions We identified concentrations and predictors of several pesticides among pregnant women in Puerto Rico. Further research is needed to understand what aspects of the predictors identified lead to greater exposure, and whether exposure during pregnancy is associated with adverse health.http://deepblue.lib.umich.edu/bitstream/2027.42/109451/1/12940_2014_Article_800.pd

    Direct Measurement of Perchlorate Exposure Biomarkers in a Highly Exposed Population: A Pilot Study

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    Exposure to perchlorate is ubiquitous in the United States and has been found to be widespread in food and drinking water. People living in the lower Colorado River region may have perchlorate exposure because of perchlorate in ground water and locally-grown produce. Relatively high doses of perchlorate can inhibit iodine uptake and impair thyroid function, and thus could impair neurological development in utero. We examined human exposures to perchlorate in the Imperial Valley among individuals consuming locally grown produce and compared perchlorate exposure doses to state and federal reference doses. We collected 24-hour urine specimen from a convenience sample of 31 individuals and measured urinary excretion rates of perchlorate, thiocyanate, nitrate, and iodide. In addition, drinking water and local produce were also sampled for perchlorate. All but two of the water samples tested negative for perchlorate. Perchlorate levels in 79 produce samples ranged from non-detect to 1816 ppb. Estimated perchlorate doses ranged from 0.02 to 0.51 µg/kg of body weight/day. Perchlorate dose increased with the number of servings of dairy products consumed and with estimated perchlorate levels in produce consumed. The geometric mean perchlorate dose was 70% higher than for the NHANES reference population. Our sample of 31 Imperial Valley residents had higher perchlorate dose levels compared with national reference ranges. Although none of our exposure estimates exceeded the U. S. EPA reference dose, three participants exceeded the acceptable daily dose as defined by bench mark dose methods used by the California Office of Environmental Health Hazard Assessment

    Oxidation mechanism of formic acid on the bismuth adatom-modified Pt(111) surface

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    In order to improve catalytic processes, elucidation of reaction mechanisms is essential. Here, supported by a combination of experimental and computational results, the oxidation mechanism of formic acid on Pt(111) electrodes modified by the incorporation of bismuth adatoms is revealed. In the proposed model, formic acid is first physisorbed on bismuth and then deprotonated and chemisorbed in formate form, also on bismuth, from which configuration the C-H bond is cleaved, on a neighbor Pt site, yielding CO2. It was found computationally that the activation energy for the C-H bond cleavage step is negligible, which was also verified experimentally.This work has been financially supported by the MINECO (Spain) (project CTQ2013-44083-P) and Generalitat Valenciana (project PROMETEOII/2014/013).Perales RondĂłn, JV.; Ferre Vilaplana, A.; Feliu, J.; Herrero, E. (2014). Oxidation mechanism of formic acid on the bismuth adatom-modified Pt(111) surface. Journal of the American Chemical Society. 136(38):13110-13113. https://doi.org/10.1021/ja505943hS13110131131363

    Factors Associated with HIV/AIDS Diagnostic Disclosure to HIV Infected Children Receiving HAART: A Multi-Center Study in Addis Ababa, Ethiopia

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    BACKGROUND: Diagnostic disclosure of HIV/AIDS to a child is becoming an increasingly common issue in clinical practice. Nevertheless, some parents and health care professionals are reluctant to inform children about their HIV infection status. The objective of this study was to identify the proportion of children who have knowledge of their serostatus and factors associated with disclosure in HIV-infected children receiving HAART in Addis Ababa, Ethiopia. METHODS: A cross-sectional study was conducted in five hospitals in Addis Ababa from February 18, 2008-April 28, 2008. The study populations were parents/caretakers and children living with HIV/AIDS who were receiving Highly Active Antiretroviral Therapy (HAART) in selected hospitals in Addis Ababa. Univariate and multivariate logistic regression analysis were carried out using SPSS 12.0.1 statistical software. RESULTS: A total of 390 children/caretaker pairs were included in the study. Two hundred forty three children (62.3%) were between 6-9 years of age. HIV/AIDS status was known by 68 (17.4%) children, 93 (29%) caretakers reported knowing the child's serostatus two years prior to our survey, 180 (46.2%) respondents said that the child should be told about his/her HIV/AIDS status when he/she is older than 14 years of age. Children less than 9 years of age and those living with educated caregivers are less likely to know their results than their counterparts. Children referred from hospital's in-patient ward before attending the HIV clinic and private clinic were more likely to know their results than those from community clinic. CONCLUSION: The proportion of disclosure of HIV/AIDS diagnosis to HIV-infected children is low. Strengthening referral linkage and health education tailored to educated caregivers are recommended to increase the rate of disclosure

    Adherence to highly active antiretroviral therapy and its correlates among HIV infected pediatric patients in Ethiopia

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    BACKGROUND: The introduction of combination antiretroviral therapy (ART) has resulted in striking reductions in HIV-related mortality. Despite increased availability of ART, children remain a neglected population. This may be due to concerns that failure to adhere appears to be related to continued viral replication, treatment failure and the emergence of drug-resistant strains of HIV. This study determines the rates and factors associated with adherence to Antiretroviral (ARV) Drug therapy in HIV-infected children who were receiving Highly Active Antiretroviral Therapy (HAART) in Addis Ababa, Ethiopia in 2008. METHODS: A cross-sectional study was conducted in five hospitals in Addis Ababa from February 18 - April 28, 2008. The study population entailed parents/caretaker and index children who were following ART in the health facilities. A structured questionnaire was used for data collection. RESULTS: A total of 390 children respondents were included in the study with a response rate of 91%. The majority, equaling 205 (52.6%) of the children, were greater than 9 years of age. Fifty five percent of the children were girls. A total of 339 children (86.9%) as reported by caregivers were adherent to antiretroviral drugs for the past 7 days before the interview. Numerous variables were found to be significantly associated with adherence: children whose parents did not pay a fee for treatment [OR = 0.39 (95%CI: 0.16, 0.92)], children who had ever received any nutritional support from the clinic [OR = 0.34 (95%CI: 0.14, 0.79)] were less likely to adhere. Whereas children who took co-trimoxazole medication/syrup besides ARVs [OR = 3.65 (95%CI: 1.24, 10.74)], children who did not know their sero-status [OR = 2.53 (95%CI: 1.24, 5.19)] and children who were not aware of their caregiver's health problem [OR = 2.45 (95%CI: 1.25, 4.81)] were more likely to adhere than their counterparts. CONCLUSION: Adherence to HAART in children in Addis Ababa was higher than other similar set-ups. However, there are still significant numbers of children who are non-adherent to HAART

    Clinical relevance of contextual factors as triggers of placebo and nocebo effects in musculoskeletal pain

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