41 research outputs found
Methoxsalen loaded chitosan coated microemulsion for effective treatment of psoriasis
Methoxsalen has been used for the treatment of psoriasis. In order to develop alternative formulations for the topical administration of methoxsalen, chitosan coated microemulsion were evaluated as delivery vehicle. Microemulsions were prepared using water, soyabean oil. Egg phosphatidylcholine, ethanol and coated with chitosan. They were characterized for shape and surface morphology, droplet size and size distribution, zeta potential, pH and viscosity. The ability of the system to deliver into the skin was evaluated using dialysis membrane and human cadaver skin. The in vitro permeation data showed that the novel system cumulative amount released was 18.75 % lesser than the microemulsion. These studies clearly show that methoxsalen loaded chitosan-coated microemulsion provides control release of methoxsalen with retention on the skin. Therefore may be appropriate vehicle for topical delivery of methoxsalen.Keywords: Microemulsions; Soyabean; Methoxsalen; Chitosa
Inter-diffusion of Plasmonic Metals and Phase Change Materials
This work investigates the problematic diffusion of metal atoms into phase
change chalcogenides, which can destroy resonances in photonic devices.
Interfaces between Ge2Sb2Te5 and metal layers were studied using X-ray
reflectivity (XRR) and reflectometry of metal-Ge2Sb2Te5 layered stacks. The
diffusion of metal atoms influences the crystallisation temperature and optical
properties of phase change materials. When Au, Ag, Al, W structures are
directly deposited on Ge2Sb2Te5 inter-diffusion occurs. Indeed, Au forms AuTe2
layers at the interface. Diffusion barrier layers, such as Si3N4 or stable
diffusionless plasmonic materials, such as TiN, can prevent the interfacial
damage. This work shows that the interfacial diffusion must be considered when
designing phase change material tuned photonic devices, and that TiN is the
most suitable plasmonic material to interface directly with Ge2Sb2Te5.Comment: 23 pages, 8 figures, articl
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Laser switching and characterisation of chalcogenides:Systems, measurements, and applicability to photonics [Invited]
Electric field effects in chalcogenides
The objective of this paper is to demonstrate that Ag readily diffuses into Sb2S3 and that electric fields can control the diffusion. Ag diffusion influences the crystallization temperature and electrical properties of Sb2S3. We studied the interface between Ag and Sb2S3 using X-ray reflectivity and show that the Ag cations can be controlled by applying an electric field. We believe this effect has technological applications in data storage devices.</p
Identification of molecular markers in Labeo rohita towards better carbohydrate utilization
The contribution of aquaculture products in providing nutritional and food security to human is increasing expeditiously with the increase in animal protein demand. Feed cost contributes more than 60% of the cost of aquaculture production. Henceforth, formulation of cheap fish feed is one of the greatest challenges in aquaculture industry. Carbohydrates are the cheap source of dietary energy. So their level of utilization in fish is an exciting area in research for decreasing the fish feed cost. Molecular markers such as microsatellite and single nucleotide polymorphism (SNP) are used for genetic mapping, quantitative trait loci identification and genome-wide association studies in several aquaculture species. In this experiment, SNPs and microsatellite markers linked to carbohydrate utilization in Labeo rohita were identified. Liver tissue samples of Labeo rohita and Labeo bata were collected from individuals fed with a customized diet with 40% carbohydrate for a period of 21 days. RNA was extracted and cDNA library was prepared and sequenced on Illumina NextSeq 500 platform. 7.5 GB of data was generated from each species. Assembly of rohu data resulted in 70, 225 contigs, out of which 6284 microsatellite markers were identified. Among which, 3838, 1817, 488, 132 and 9 were di-, tri-, tetra-, penta- and hexa-repeats, respectively. Primer modelling was successful for 4190 sequences. Similarly, 2, 14, 071 SNPs were identified using CLC bio v7.0.4 and utilizing Illumina reads obtained from Labeo bata. This study can be helpful in efficient use of carbohydrate in Labeo species for decreasing feed cost globally