Urinary and Plasma Fluoride Levels in Pregnant Women from Mexico City

Background There is need to assess the developmental neurotoxicity of fluoride. Our knowledge of prenatal fluoride exposure is challenged as few population-based studies have been conducted and these generally date back several decades, provide incomplete data on sociodemographic variables, and have methodological limitations. Objective To measure urinary and plasma fluoride levels across three time points in pregnant mothers who were enrolled in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) birth cohort study. Methods Fluoride levels were characterized in archived urine and plasma from 872 pregnant mothers sampled from the ELEMENT cohort. Various statistical methods were used to analyze the fluoride data with particular consideration for changes across three stages of pregnancy and against sociodemographic variables. Results All samples had detectable levels of fluoride. The mean urinary and plasma fluoride levels were 0.91 and 0.0221 mg/L respectively, and these were not statistically different across three stages of pregnancy. Fluoride levels correlated across the stages of pregnancy studied, with stronger correlations between neighboring stages. Urinary fluoride changed as pregnancy progressed with levels increasing until ~23 weeks and then decreasing until the end of pregnancy. For plasma fluoride, there was a decreasing trend but this was not of statistical significance. Creatinine-adjusted urinary fluoride levels did not associate consistently with any of the sociodemographic variables studied. Conclusions This study provides the most extensive characterization to date of fluoride exposure throughout pregnancy. These results provide the foundation to explore exposure-related health outcomes in the ELEMENT cohort and other studies

Prevalence and contributing factors of intestinal parasitic infections among school children with malnutrition in Hetauda, Nepal: A cross‐sectional study

Background and aimsWith existing undernutrition in the developing world, the prevalence of obesity is increasing rapidly. Some studies reported an association of intestinal parasitic infection (IPIs) with undernutrition while few recent studies reported an inverse association of IPIs with overweight and obesity. This study evaluated the comparative risk and associated factors of IPIs among under (body mass index [BMI] < 18.5), normal (BMI: 18.5-24.9) and overweight (BMI > 24.9) school-aged adolescents.MethodsA total of 105 fecal samples were collected, with 35 samples from each group. The collected samples were tested for the presence of intestinal parasites via concentration method, and the parasites were identified morphologically.ResultsOverall prevalence of IPIs was 5.71% with 3 protozoa viz Giardia lamblia (2.86%), Entamoeba histolytica (1.90%) and Endolimax nana (0.95%). Univariate and multivariable regression analysis indicated none of the nutritional, socioeconomic status, demographic, lifestyle and behavioral characteristics were significantly associated with the prevalence of overall IPIs. Yet, significant numbers of male reported undernutrition and elevated risk of IPIs in this study population.ConclusionDespite low prevalence of IPIs in this study, risk of IPIs is attributable to individual differences in behavior like "not using soap for hand washing". Relatively elevated malnutrition with risky hygiene behaviors, male adolescents appeared as risky cluster of school age population

Epidemiology, Risk Factors and Seasonal Variation of Scrub Typhus Fever in Central Nepal

Scrub typhus is a mite-borne acute febrile illness caused by Orientia. tsutsugamushi, a zoonotic bacterial infection common in the region known as the tsutsugamushi triangle. This study aims to determine the seroprevalence, seasonal variation, and risk factors of scrub typhus among the acute febrile illness patients attending different hospitals of central Nepal. Blood samples were collected from hospitalized patients of acute febrile illness suspected of scrub typhus infection attending different hospitals of central Nepal from April 2017 to March 2018. The IgM antibody to Orientia tsutsugamushi was detected by using the Scrub Typhus Detect™ Kit. Among the total cases (1585), 358 (22.58%) were positive for IgM Antibodies. Multivariate analysis identified several risks factors to be significantly associated with the scrub typhus infection, including gender (female) (odds ratio [OR] = 1.976, p ≤ 0.001, confidence interval [CI] = 1.417⁻2.756), rural residential location (odds ratio [OR] = 0.431, p = 0.001, confidence interval [CI] = 0.260⁻0.715), house near grassland (odds ratio [OR] = 3.288, p ≤ 0.001, confidence interval [CI] = 1.935⁻5.587), and working in the field (odds ratio [OR] = 9.764, p = 0.004, confidence interval [CI] = 2.059⁻46.315). The study findings indicate scrub typhus infection to be a significant health problem in Nepal. The proper diagnosis of infection cases, timely institution of therapy, public awareness, and vector control are important measures to be taken for the prevention and management of scrub typhus

Survey of intestinal parasites in swine farms raised in Western Nepal

Abstract Background Pigs (Sus scrofa domesticus), an important domestic livestock, are generally affected by helminth and protozoan parasites. Rearing pigs in rural regions in Nepal is a common practice for subsistence farming. A cross‐sectional survey was conducted to determine the occurrence of gastrointestinal parasites (GIPs) in pigs raised in Western Nepal. Methods A total of 200 faecal samples from commercial and smallholder farms were examined by wet mounts, flotation, sedimentation and staining techniques. Results The results revealed that overall 86.5% of samples were found shedding oocysts or eggs of one or more GIPs. Three species of protozoa [Eimeria sp. (26%), Entamoeba coli (25.5%) and Coccidia (29%)] and nine species of helminths parasites (Ascaris suum (32.5%), Trichuris suis (30%), strongyle‐type nematode (27.5%), hookworm (26%), Fasciola sp. (17.5%), Physaloptera sp. (17.5%), Strongyloides sp. (17.5%), Metastrongylus sp. (8%) and Oesophagostomum sp. (5.5%)] were identified. Female pigs were found to have higher protozoan infection than males, but such a difference was not noticed with regard to helminth parasites. Strongyles and Oesophagostomum infection were higher in commercial farms compared to smallholder farms, whereas the prevalences of E. coli and other protozoans were higher in smallholder farms. Among the contextual factors evaluated for association, weight and gender of pigs, and annual income and gender of managers/caretakers were significantly (p < 0.05) associated with the prevalence of GIPs in pigs. The overall prevalence of certain helminths such as strongyle‐type nematode and A. suum was significantly (p < 0.05) associated with the weight of pigs after adjusting other contextual factors. Conclusions This study detected relatively high prevalence of intestinal parasites in domestic pig facilities. Molecular epidemiological studies are essential to verify the exact zoonotic potential of parasites carried by pigs in the region. An effective periodic monitoring of GIPs of pigs needs to be carried out to minimize their further dissemination

Association of cord blood levels of lead, arsenic, and zinc and home environment with children neurodevelopment at 36 months living in Chitwan Valley, Nepal.

Inconsistent results continue to be reported from studies linking low-level prenatal lead exposure and child development. Because of limited earlier epidemiological studies with birth cohort follow up design, it still remains inconclusive that either the associations of cord blood level of toxic, and essential elements, and postnatal raising environment on neurodevelopment of children remains constant throughout childhood or change over time.This study aims to investigate the influence of in utero toxic [lead (Pb) and arsenic (As)] and essential elements [zinc (Zn)] levels on neurodevelopment of 36 months children in Chitwan valley, Nepal taking the postnatal environment into account.In this birth cohort study, participants (N=100 mother-infants' pairs) were recruited in Chitwan district, Nepal. We measured Pb, As and Zn concentrations in cord blood. Postnatal raising environment (i.e., Home score or home environment hereafter) was evaluated using Home Observation for Measurement of Environment (HOME) scale. Neurodevelopment of children at 36 months of age (n=70) were assessed using Bayley Scale of Infant Development, Second Edition (BSID II). Multivariate regression was performed (n=70) to see the association of in utero toxic and essential elements level and home environment with neurodevelopment score adjusted for covariates.Cord blood levels of Pb, As and Zn were not associated with any BSID II cluster scores of 36 months children. The children with relatively superior HOME score and concurrent nutritional status (weight at 36 months) showed better cognitive development (i.e., MDI scores) and motor functions than their counterparts, respectively.In this general population in Nepal, prenatal Pb, As and Zn levels are not important determinants of the neurodevelopment of 36- month-old children while a consistent beneficial effect of a stimulating home environment on neurodevelopmental indicators is continued

Dissociative electron attachment to formic acid

Dissociative electron attachment to formic acid (HCOOH) is studied in a crossed beams experiment using mass spectrometric detection of the product ions in the electron energy range 0-15 eV, including the measurement of absolute cross-sections. Unlike the previous reports, we observe the formation of H&#8722; from this molecule, in addition to the fragment negative ions namely O&#8722;/OH&#8722; and HCOO&#8722;, which were observed earlier. The absolute cross-sections indicate that H&#8722; formation is one of the important DEA channels in this molecule

Novel Decay Channels of Carbon Cluster Ions, C40z+ and C41z+ (z = 3, 4)

We have analyzed spontaneous decay reactions of triply and quadruply charged C40z+ and C41z+ cluster ions which are formed from C60 fullerenes by electron-impact ionization. A new but very weak decay reaction for the even-sized carbon cluster ions is observed, namely loss of C3. The odd-sized cluster ions preferentially decay by loss of carbon atoms and, to a lesser degree, trimers. A weak signal due to C2 loss is observed for C413+. We discuss these decay channels in terms of the geometric structure of these metastable, relatively cold cluster ions

On Enhanced Hydrogen Adsorption on Alkali (Cesium) Doped C60 and Effects of the Quantum Nature of the H2 molecule on Physisorption Energies

Hydrogen storage by physisorption in carbon based materials is hindered by low adsorption energies. In the last decade doping of carbon materials with alkali, earth alkali or other metal atoms was proposed as a means to enhance adsorption energies, and some experiments have shown promising results. We investigate the upper bounds of hydrogen storage capacities of C60Cs clusters grown in ultracold helium nanodroplets by analyzing anomalies in the ion abundance that indicate shell closure of hydrogen adsorption shells. On bare , a commensurate phase with 32H2 molecules was identified in previous experiments. Doping C60 with a single cesium atom leads to an increase in relative ion abundance for the first 10H2 molecules, and the closure of the commensurate phase is shifted from 32 to 42H2 molecules. Density functional theory calculations indicate that thirteen energetically enhanced adsorption sites exist, where six of them fill the groove between Cs and C60 and 7 are located at the cesium atom. We emphasize the large effect of the quantum nature of the hydrogen molecule on the adsorption energies, i.e. the adsorption energies are decreased by around 50% for (H2)C60Cs and up to 80% for (H2)C60 by harmonic zero-point corrections, which represent an upper bound to corrections for dissociation energies (De to D0) by the vibrational ground states. Five normal modes of libration and vibration of H2 physisorbed on the substrate contribute primarily to this large decrease in adsorption energies. A similar effect can be found for H2 physisorbed on benzene and is expected to be found for any other weakly H2-binding substrate