25 research outputs found
Bilateral Keratoconus in a Patient with Isolated Foveal Hypoplasia
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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
Effects of Microhydrophobic Porous Layer on Water Distribution in Polymer Electrolyte Membrane Fuel Cells
Optimizing Lifespan of Circular Products: A Generic Dynamic Programming Approach for Energy-Using Products
Slowing down replacement cycles to reduce resource depletion and prevent waste generation is a promising path toward a circular economy (CE). However, an obligation to longevity only sometimes makes sense. It could sometimes even backfire if one focuses exclusively on material resource efficiency measures of the production phase and neglects implications on the use phase. The (environmental) lifespan of circular products should, therefore, be optimized, not maximized, considering all life cycle phases. In this paper, a generic method for determining the optimal environmental lifespan (OEL) of energy-using products (EuPs) in a CE is developed, allowing the simultaneous inclusion of various replacement options and lifetime extension processes, like re-manufacturing, in the assessment. A dynamic programming approach is used to minimize the cumulative environmental impact or costs over a specific time horizon, which allows considering an unordered sequence of replacement decisions with various sets of products. The method further accounts for technology improvement as well as efficiency degradation due to usage and a dynamic energy supply over the use phase. To illustrate the application, the OEL of gas heating appliances in Germany is calculated considering newly evolved products and re-manufactured products as replacement options. The case-study results show that with an average heat demand of a dwelling in Germany, the OEL is just 7 years for climate change impacts and 11 years for the aggregated environmental indicator, (Formula presented.). If efficiency degradation during use is considered, the OEL for both environmental impact assessment methods even lowers to 1 year. Products are frequently replaced with re-manufactured products to completely restore efficiency at low investment cost, resulting in higher savings potential. This not only implies that an early replacement before the product breaks down is recommended but also that it is essential to maintain the system and, thus, to prevent potential efficiency degradation. The results for cost optimization, as well as currently observed lifespans, vary considerably from this.ISSN:1996-107
Optimizing Lifespan of Circular Products: A Generic Dynamic Programming Approach for Energy-Using Products
Slowing down replacement cycles to reduce resource depletion and prevent waste generation is a promising path toward a circular economy (CE). However, an obligation to longevity only sometimes makes sense. It could sometimes even backfire if one focuses exclusively on material resource efficiency measures of the production phase and neglects implications on the use phase. The (environmental) lifespan of circular products should, therefore, be optimized, not maximized, considering all life cycle phases. In this paper, a generic method for determining the optimal environmental lifespan (OEL) of energy-using products (EuPs) in a CE is developed, allowing the simultaneous inclusion of various replacement options and lifetime extension processes, like re-manufacturing, in the assessment. A dynamic programming approach is used to minimize the cumulative environmental impact or costs over a specific time horizon, which allows considering an unordered sequence of replacement decisions with various sets of products. The method further accounts for technology improvement as well as efficiency degradation due to usage and a dynamic energy supply over the use phase. To illustrate the application, the OEL of gas heating appliances in Germany is calculated considering newly evolved products and re-manufactured products as replacement options. The case-study results show that with an average heat demand of a dwelling in Germany, the OEL is just 7 years for climate change impacts and 11 years for the aggregated environmental indicator, ReCiPeendpoint(total). If efficiency degradation during use is considered, the OEL for both environmental impact assessment methods even lowers to 1 year. Products are frequently replaced with re-manufactured products to completely restore efficiency at low investment cost, resulting in higher savings potential. This not only implies that an early replacement before the product breaks down is recommended but also that it is essential to maintain the system and, thus, to prevent potential efficiency degradation. The results for cost optimization, as well as currently observed lifespans, vary considerably from this
An innovative solar assisted desiccant-based evaporative cooling system for co-production of water and cooling in hot and humid climates
Although evaporative coolers consume much lower electricity than the vapor compression systems, they are not applicable in humid climates. Combination of desiccant wheels and evaporative coolers, known as desiccant-based evaporative cooling systems, allows evaporative coolers to be used in humid climates, which provide significant energy and environmental advantages with respect to vapor compression systems. However, one of the main disadvantages of evaporative cooling is the high water. Regarding the global water crisis, a cooling system which saves both water and energy will be an attractive alternative to the current cooling systems. To this aim, this paper presents a novel desiccant-based evaporative cooling system for co-production of water and cooling. In this system, the moisture content of exhaust regeneration air is recycled to cover all of the evaporative cooler water consumption, and also part of the domestic water usage. To evaluate the system performance, dynamic hourly simulation of the proposed system as well as a reference vapor compression system was performed for a typical 60m2 building in hot and humid climate of Bandar Abbas, Iran. The simulation results show that the proposed system is able to provide comfort temperature and relative humidity in a hot and humid climate. Moisture harvesting produce about 590L water during a week, which covers all of the evaporative cooler water consumption, and provides an excess amount of 289L for domestic usage. Monthly integrated results indicate that electricity consumption of the proposed system is 60% lower than the reference system, while its natural gas consumption is 30% higher than VCS, which is due to the high regeneration temperature in some hours. In other worlds, this system replace electricity consumption, a high-exergy and expensive energy carrier, with heat consumption. This system leads to 18.7% saving of CO2 emissions over a month. Economic evaluation proves the economic feasibility of proposed system with a payback period of 3 years. In conclusion, proposed system provide a more environmental friendly cooling system for water, energy and carbon saving
Comparison of the effect of Propofol, Etomidate and Thiopental on Seizure duration following electro convulsion therapy:A clinical trial study
Background and Objective: Electro convulsion therapy (ECT) is one of the most common ways for treatment of psychiatric disorders. The aim of this study was to compare the effect of Propofol, Etomidate, and Thiopental on seizure and recovery duration following ECT.
Methods: In this clinical trial study, 90 patients diagnosed with a psychiatric disorder by a psychiatrist, who need to be treated by ECT in 5 Azar hospital, Gorgan, north Iran. The patients were randomly divided into the three groups by simple random allocation method. Interventions included standard monitoring and pre-oxygenation with 100% FiO2 for 3 minutes for all patients in three groups. Anesthesia of the patients in the first, second, and third group was done with Thiopental (1.5 mg/kg), Propofol (0.6 mg/kg), and Etomidate (0.1 mg/kg), respectively. Administration of Succinyl Colin (0.5 mg/kg) as muscle relaxant and Atropine for prevention of bradycardia was uesd in all patients. Duration of seizure and recovery; changes in hemodynamic status including heart rate (HR) and mean arterial pressure (MAP); and amount of charge for ECT were recorded for each subject.
Results: Mean of seizure duration in Thiopental, Propofol, and Etomidate groups were 43.72±11.81, 35.74±10.58 and 45.81±17.26 seconds, respectively (P<0.05). Amount of charge for ECT in 3 sessions of treatment and changes of HR were not different between the 3 groups. Changes of MAP in the Propofol group was significantly less than other two groups (P<0.05). Recovery time following ECT was the least in Etomidate group in comparison with Thiopental and Propofol (P<0.05).
Conclusion: Ethomidate and Thiopental had the same effect on increasing seizure duration. However, due to the significant reduction in recovery time compared with Thiopental, Ethomidate may be considered as the best choice
Mapping Local Synergies: Spatio-Temporal Analysis of Switzerland’s Waste Heat Potentials vs. Heat Demand
As nations transition to renewable energy, making use of waste heat becomes crucial to combat climate change. This study focused on quantifying Switzerland’s waste heat potential from industrial processes and waste-to-energy facilities, using diverse methodologies tailored to facility characteristics and data availability. We assessed potential waste heat utilization by comparing local heat supply and demand, creating comprehensive heat-balance maps considering different temperature levels and seasonal fluctuations. Results revealed a substantial annual waste heat potential of 37 TWh, with almost half (17 TWh) below 45 °C, primarily from wastewater. Heat between 45 °C and 70 °C, ideal, e.g., for greenhouse heating, is mainly available from solid waste incineration plants, while industries contributed to waste heat supply exceeding 150 °C. In contrast to heat demand, seasonal variations in heat supply were small, with a 12% winter decrease. Analyzing heat demand versus supply unveiled local and seasonal disparities. Most municipalities had a net excess heat demand (totaling 89 TWh). Additionally, waste heat could not satisfy 8 TWh of industrial process heat demand exceeding 400 °C, emphasizing reliance on primary energy sources for higher-temperature heat. Targeted strategies are essential for effective waste heat utilization, especially tapping into low-temperature sources. Integrating these sources with low-carbon technologies can pave the way to a sustainable energy future.ISSN:1996-107
Implementing conceptual model using renewable energies in rural area of Iran
In a glance, more than three billion people live in the rural areas of low and middle income countries. In most cases, rural households have many unmet energy needs including cooking, lighting, heating, transportation and telecommunication needs. The main goal of this study is Implementing Conceptual Model Using Renewable Energies in Rural Area of Iran. In this study, the Weibull and Angestrom distribution methods were used to assess the potential of wind and solar energy range in Chaharmahal va Bakhtiari province of Iran (The Case study). After determining the values calculated based on meteorological stations' data, the IDW interpolation method in GIS software was used for the entire geographic range of the province. After reviewing multiple regions and identifying potential classes, a village which has the potential to be enough sun and wind energy was selected (Kahkesh village) and then a field survey based on biomass resources was accomplished. The needs of rural residents and rural renewable energy potential was evaluated by study conceptual frameworks during one year. By dividing the value of frameworks energies the amount of energy saving can be calculated. Finally, it recommended that for utilizing the renewable energies in rural areas, as will be discussed in the present work and particularly using the conceptual frameworks, is performed