60 research outputs found
Dosimetry of Cobalt 60 Gamma Chamber
Ferrous sulphate-benzoic acid-xylen(tl orange (FBX) dosimetric system is linear in the range fl|0m 0.01 Gy to 10 Gy and can be used in the case of a nuclear accident, for documenting clinical doses in total-body irradiations in radiation therapy as well as for measuring daily radiation dose during external beam therapy because of its tissue-equivallency. FBX system is stable up to 15 days in the range 15 - 60 degree centigrade. It is independent of photon energy up to 3 ke V and is fairly dose rate in dependent in the range from 0.01 to 2.5 Gy/min. Besides its use in radiation therapy, external beam therapy and nuclear accidents, the present study shows that this dosimeter can be effectively used for determining positional variation inside the gamma chamber. This has been detected by placing dosimetric solutions in small bottles kept in two racks of the phantom in a symmetrical fashion. Average variations in two tracks were found to be 2.74 per cent, 0.33 per cent, 4 per cent and 4.83 per cent
Structure of Polyethylene Prepared Between Non Metallic Electrodes
The X-Ray diffraction method has been applied to study the structural changes that polyethylene may undergo when prepared between glass and perspex electrodes at different temperatures. The results indicate that polyethylene does not undergo any considerable structural change under the prevailing conditions
Effect of Hot Water Extraction on pyrolysis of tender coconut fruit biomass: kinetic and thermodynamic parameters
Effect of pre-treatment of tender coconut fruit bio-mass powder with hot water on physico-chemical properties and thermal degradation behavior were investigated. The physico-chemical parameters were evaluated using ASTM standard protocols. The thermal degradation behavior was studied at heating rates of 10, 15 and 20oC/min under inert (N2) atmospheric conditions using TG/DTG techniques. The activation energies at each heating rate were determined using Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), Starink, and Tang models. The pre-treatment with hot water improved the proximate and ultimate analyses parameters and calorific value. The higher heating values (HHV) for untreated and treated tender coconut fruit biomass were 18.57 and 21.26 kJ/kg, respectively. The values of activation energy (Eα) for the un-treated biomass powder were estimated to be 389.25, 397.81 and 398.77 and 397.97kJ/mol for FWO, KAS, Tang, and Starink models, respectively and for the treated biomass these were 125.43, 118.61, 118.99 and 118.94kJ/mol, respectively. On an average the Eα of the treated coconut biomass was nearly three times lower than that for the untreated biomass. The results indicated that pre-treatment with hot water improved the fuel characteristics and thermal degradation behavior of the tender coconut shell biomass. The water extract exhibited high COD and BOD values and might be used as the feed-stock for biogas generation
Midazolam infusion and disease severity affect the level of sedation in children: a parametric time-to-event analysis
Aim In critically ill mechanically ventilated children, midazolam is used first line for sedation, however its exact sedative effects have been difficult to quantify. In this analysis, we use parametric time-to-event (PTTE) analysis to quantify the effects of midazolam in critically ill children.Methods In the PTTE analysis, data was analyzed from a published study in mechanically ventilated children in which blinded midazolam or placebo infusions were administered during a sedation interruption phase until, based on COMFORT-B and NISS scores, patients became undersedated and unblinded midazolam was restarted. Using NONMEM (R) v.7.4.3., restart of unblinded midazolam was analysed as event. Patients in the trial were divided into internal and external validation cohorts prior to analysis.Results Data contained 138 events from 79 individuals (37 blinded midazolam; 42 blinded placebo). In the PTTE model, the baseline hazard was best described by a constant function. Midazolam reduced the hazard for restart of unblinded midazolam due to undersedation by 51%. In the blinded midazolam group, time to midazolam restart was 26 h versus 58 h in patients with low versus high disease severity upon admission (PRISM II 21), respectively. For blinded placebo, these times were 14 h and 33 h, respectively. The model performed well in an external validation with 42 individuals.Conclusion The PTTE analysis effectively quantified the effect of midazolam in prolonging sedation and also the influence of disease severity on sedation in mechanically ventilated critically ill children, and provides a valuable tool to quantify the effect of sedatives. Clinical trial number and registry URL: Netherlands Trial Register, Trial NL1913 (NTR2030), date registered 28 September 2009.Pharmacolog
The Risk Factors of Seasonal Hyperacute Panuveitis
Background: Seasonal Hyperacute Panuveitis (SHAPU) is an eye disease of unclear aetiology occurring cyclically during the autumn in odd years in Nepal causing blindness within a week. This study is the first of its type to investigate the risk factors of SHAPU. Methods: A multicentric national level case–control study was performed during the 2017 SHAPU outbreak. Cases were matched to controls in a 1:3 ratio based on age, sex and geographic area. Questionnaire-based personal interview was used and risk factors were categorized as biological and behavioral. For univariate analysis, frequency, median and interquartile range was calculated. Chi-squared test with/without continuity correction and Fisher’s exact test were used. Multivariate conditional logistic regressions were used for all the independent variables for p <0.1 in the univariate analyses. Results: We identified 35 cases and 105 controls; 71.4% were children≤16 years (38-day infant to 50-year-old). All were immunocompetent individuals, males were 57.1% and females 42.9%. Potential risks such as visible moths/butterfly activity, contact with livestock, and attending mass gatherings of people were not reported more frequently in cases vs controls in univariate analyses. Differences in possibly protective factors such as self-reported mosquito net use, light off at night while sleeping, and habit of hands/face washing after physical contact/touch with any insects/butterflies/birds were not statistically significant between both groups. In multivariate model, SHAPU cases were significantly more likely than controls to report physical contact with butterflies/white moths (Adjusted OR:6.89; CI:2.79–17.01,p < .001). Conclusions: Direct physical contact with butterflies/moths was associated with significantly increased odds of SHAPU cases
Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018
Anemia is a globally widespread condition in women and is associated with reduced economic productivity and increased mortality worldwide. Here we map annual 2000–2018 geospatial estimates of anemia prevalence in women of reproductive age (15–49 years) across 82 low- and middle-income countries (LMICs), stratify anemia by severity and aggregate results to policy-relevant administrative and national levels. Additionally, we provide subnational disparity analyses to provide a comprehensive overview of anemia prevalence inequalities within these countries and predict progress toward the World Health Organization’s Global Nutrition Target (WHO GNT) to reduce anemia by half by 2030. Our results demonstrate widespread moderate improvements in overall anemia prevalence but identify only three LMICs with a high probability of achieving the WHO GNT by 2030 at a national scale, and no LMIC is expected to achieve the target in all their subnational administrative units. Our maps show where large within-country disparities occur, as well as areas likely to fall short of the WHO GNT, offering precision public health tools so that adequate resource allocation and subsequent interventions can be targeted to the most vulnerable populations.Peer reviewe
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Mapping development and health effects of cooking with solid fuels in low-income and middle-income countries, 2000–18: a geospatial modelling study
Background
More than 3 billion people do not have access to clean energy and primarily use solid fuels to cook. Use of solid fuels generates household air pollution, which was associated with more than 2 million deaths in 2019. Although local patterns in cooking vary systematically, subnational trends in use of solid fuels have yet to be comprehensively analysed. We estimated the prevalence of solid-fuel use with high spatial resolution to explore subnational inequalities, assess local progress, and assess the effects on health in low-income and middle-income countries (LMICs) without universal access to clean fuels.
Methods
We did a geospatial modelling study to map the prevalence of solid-fuel use for cooking at a 5 km × 5 km resolution in 98 LMICs based on 2·1 million household observations of the primary cooking fuel used from 663 population-based household surveys over the years 2000 to 2018. We use observed temporal patterns to forecast household air pollution in 2030 and to assess the probability of attaining the Sustainable Development Goal (SDG) target indicator for clean cooking. We aligned our estimates of household air pollution to geospatial estimates of ambient air pollution to establish the risk transition occurring in LMICs. Finally, we quantified the effect of residual primary solid-fuel use for cooking on child health by doing a counterfactual risk assessment to estimate the proportion of deaths from lower respiratory tract infections in children younger than 5 years that could be associated with household air pollution.
Findings
Although primary reliance on solid-fuel use for cooking has declined globally, it remains widespread. 593 million people live in districts where the prevalence of solid-fuel use for cooking exceeds 95%. 66% of people in LMICs live in districts that are not on track to meet the SDG target for universal access to clean energy by 2030. Household air pollution continues to be a major contributor to particulate exposure in LMICs, and rising ambient air pollution is undermining potential gains from reductions in the prevalence of solid-fuel use for cooking in many countries. We estimated that, in 2018, 205 000 (95% uncertainty interval 147 000–257 000) children younger than 5 years died from lower respiratory tract infections that could be attributed to household air pollution.
Interpretation
Efforts to accelerate the adoption of clean cooking fuels need to be substantially increased and recalibrated to account for subnational inequalities, because there are substantial opportunities to improve air quality and avert child mortality associated with household air pollution
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