2 research outputs found
Effect of Substrates on the Photoelectrochemical Reduction of Water over Cathodically Electrodeposited pโType Cu<sub>2</sub>O Thin Films
In this study, we demonstrate development
of p-Cu<sub>2</sub>O thin films through cathodic electrodeposition
technique at constant current of 0.1 mA/cm<sup>2</sup> on Cu, Al,
and indium tin oxide (ITO) substrates from basic CuSO<sub>4</sub> solution
containing Triton X-100 as the surfactant at 30โ35 ยฐC.
The optical and morphological characterizations of the semiconductors
have been carried out using UVโvis spectroscopy, X-ray diffraction
(XRD), scanning electron microscopy (SEM), and Raman spectroscopy.
The band gap energy of โผ2.1 eV is recorded, whereas SEM reveals
that the surface morphology is covered with Cu<sub>2</sub>O semiconductors.
XRD analyses confirm that with change in substrate, the size of Cu<sub>2</sub>O โcubicโ crystallites decreases from ITO to
Al to Cu substrates. Photoelectrochemical characterizations under
dark and illuminated conditions have been carried out through linear
sweep voltammetry, chronoamperometry and electrochemical impedance
spectroscopic analysis. The photoelectrochemical reduction of water
(H<sub>2</sub>O โ H<sub>2</sub>) in pH 4.9 aqueous solutions
over the different substrates vary in the order of Cu > Al >
ITO. The highest current of 4.6 mA/cm<sup>2</sup> has been recorded
over the Cu substrate even at a low illumination of 35 mW/cm<sup>2</sup>, which is significantly higher than the values (2.4 mA/cm<sup>2</sup> on Au coated FTO or 4.07 mA/cm<sup>2</sup> on Cu foil substrate
at an illumination of 100 mW/cm<sup>2</sup>) reported in literature
Global, regional, and national burden of stroke and its risk factors, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019
BackgroundRegularly updated data on stroke and its pathological types, including data on their incidence, prevalence, mortality, disability, risk factors, and epidemiological trends, are important for evidence-based stroke care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) aims to provide a standardised and comprehensive measurement of these metrics at global, regional, and national levels.MethodsWe applied GBD 2019 analytical tools to calculate stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and the population attributable fraction (PAF) of DALYs (with corresponding 95% uncertainty intervals [UIs]) associated with 19 risk factors, for 204 countries and territories from 1990 to 2019. These estimates were provided for ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and all strokes combined, and stratified by sex, age group, and World Bank country income level.FindingsIn 2019, there were 12ยท2 million (95% UI 11ยท0-13ยท6) incident cases of stroke, 101 million (93ยท2-111) prevalent cases of stroke, 143 million (133-153) DALYs due to stroke, and 6ยท55 million (6ยท00-7ยท02) deaths from stroke. Globally, stroke remained the second-leading cause of death (11ยท6% [10ยท8-12ยท2] of total deaths) and the third-leading cause of death and disability combined (5ยท7% [5ยท1-6ยท2] of total DALYs) in 2019. From 1990 to 2019, the absolute number of incident strokes increased by 70ยท0% (67ยท0-73ยท0), prevalent strokes increased by 85ยท0% (83ยท0-88ยท0), deaths from stroke increased by 43ยท0% (31ยท0-55ยท0), and DALYs due to stroke increased by 32ยท0% (22ยท0-42ยท0). During the same period, age-standardised rates of stroke incidence decreased by 17ยท0% (15ยท0-18ยท0), mortality decreased by 36ยท0% (31ยท0-42ยท0), prevalence decreased by 6ยท0% (5ยท0-7ยท0), and DALYs decreased by 36ยท0% (31ยท0-42ยท0). However, among people younger than 70 years, prevalence rates increased by 22ยท0% (21ยท0-24ยท0) and incidence rates increased by 15ยท0% (12ยท0-18ยท0). In 2019, the age-standardised stroke-related mortality rate was 3ยท6 (3ยท5-3ยท8) times higher in the World Bank low-income group than in the World Bank high-income group, and the age-standardised stroke-related DALY rate was 3ยท7 (3ยท5-3ยท9) times higher in the low-income group than the high-income group. Ischaemic stroke constituted 62ยท4% of all incident strokes in 2019 (7ยท63 million [6ยท57-8ยท96]), while intracerebral haemorrhage constituted 27ยท9% (3ยท41 million [2ยท97-3ยท91]) and subarachnoid haemorrhage constituted 9ยท7% (1ยท18 million [1ยท01-1ยท39]). In 2019, the five leading risk factors for stroke were high systolic blood pressure (contributing to 79ยท6 million [67ยท7-90ยท8] DALYs or 55ยท5% [48ยท2-62ยท0] of total stroke DALYs), high body-mass index (34ยท9 million [22ยท3-48ยท6] DALYs or 24ยท3% [15ยท7-33ยท2]), high fasting plasma glucose (28ยท9 million [19ยท8-41ยท5] DALYs or 20ยท2% [13ยท8-29ยท1]), ambient particulate matter pollution (28ยท7 million [23ยท4-33ยท4] DALYs or 20ยท1% [16ยท6-23ยท0]), and smoking (25ยท3 million [22ยท6-28ยท2] DALYs or 17ยท6% [16ยท4-19ยท0]).InterpretationThe annual number of strokes and deaths due to stroke increased substantially from 1990 to 2019, despite substantial reductions in age-standardised rates, particularly among people older than 70 years. The highest age-standardised stroke-related mortality and DALY rates were in the World Bank low-income group. The fastest-growing risk factor for stroke between 1990 and 2019 was high body-mass index. Without urgent implementation of effective primary prevention strategies, the stroke burden will probably continue to grow across the world, particularly in low-income countries.FundingBill & Melinda Gates Foundation