20 research outputs found

    Comparison Between Conventional Design and Cathode Gas Recirculation Design of a Direct-Syngas Solid Oxide Fuel Cell–Gas Turbine Hybrid Systems Part I: Design Performance

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    In this paper, a conventional SOFC–GT hybrid system and a SOFC–GT hybrid system with cathode gas recirculation system fueled with syngas as the main source of energy were analyzed and their performances were compared. In the conventional SOFC–GT hybrid system, the incoming air to the cathode was heated at air recuperator and air preheater to meet the required cathode inlet temperature. In the SOFC–GT hybrid system with cathode gas recirculation, besides air recuperator and air preheater, the recirculation of the cathode exhaust gas was also used to meet the required cathode inlet temperature. The system performances have been analyzed by means of models developed with the computer program Cycle–Tempo. A complete model of the SOFC–GT hybrid system with these two configurations evaluated in terms of energy and exergy efficiencies and their performance characteristics were compared. Simulation results show that the electrical energy and exergy efficiencies achieved in the cathode gas recirculation plant (64.76% and 66.28%, respectively) are significantly higher than those obtained in the conventional plant (54.53% and 55.8%). Article History: Received Feb 23rd 2017; Received in revised form May 26th 2017; Accepted June 1st 2017; Available onlineHow to Cite This Article: Azami, V, and Yari, M. (2017) Comparison between conventional design and cathode gas recirculation design of a direct-syngas solid oxide fuel cell–gas turbine hybrid systems part I: Design performance. International Journal of Renewable Energy Development, 6(2), 127-136.https://doi.org/10.14710/ijred.6.2.127-13

    The unfinished agenda of communicable diseases among children and adolescents before the COVID-19 pandemic, 1990-2019: a systematic analysis of the Global Burden of Disease Study 2019

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    BACKGROUND: Communicable disease control has long been a focus of global health policy. There have been substantial reductions in the burden and mortality of communicable diseases among children younger than 5 years, but we know less about this burden in older children and adolescents, and it is unclear whether current programmes and policies remain aligned with targets for intervention. This knowledge is especially important for policy and programmes in the context of the COVID-19 pandemic. We aimed to use the Global Burden of Disease (GBD) Study 2019 to systematically characterise the burden of communicable diseases across childhood and adolescence. METHODS: In this systematic analysis of the GBD study from 1990 to 2019, all communicable diseases and their manifestations as modelled within GBD 2019 were included, categorised as 16 subgroups of common diseases or presentations. Data were reported for absolute count, prevalence, and incidence across measures of cause-specific mortality (deaths and years of life lost), disability (years lived with disability [YLDs]), and disease burden (disability-adjusted life-years [DALYs]) for children and adolescents aged 0-24 years. Data were reported across the Socio-demographic Index (SDI) and across time (1990-2019), and for 204 countries and territories. For HIV, we reported the mortality-to-incidence ratio (MIR) as a measure of health system performance. FINDINGS: In 2019, there were 3·0 million deaths and 30·0 million years of healthy life lost to disability (as measured by YLDs), corresponding to 288·4 million DALYs from communicable diseases among children and adolescents globally (57·3% of total communicable disease burden across all ages). Over time, there has been a shift in communicable disease burden from young children to older children and adolescents (largely driven by the considerable reductions in children younger than 5 years and slower progress elsewhere), although children younger than 5 years still accounted for most of the communicable disease burden in 2019. Disease burden and mortality were predominantly in low-SDI settings, with high and high-middle SDI settings also having an appreciable burden of communicable disease morbidity (4·0 million YLDs in 2019 alone). Three cause groups (enteric infections, lower-respiratory-tract infections, and malaria) accounted for 59·8% of the global communicable disease burden in children and adolescents, with tuberculosis and HIV both emerging as important causes during adolescence. HIV was the only cause for which disease burden increased over time, particularly in children and adolescents older than 5 years, and especially in females. Excess MIRs for HIV were observed for males aged 15-19 years in low-SDI settings. INTERPRETATION: Our analysis supports continued policy focus on enteric infections and lower-respiratory-tract infections, with orientation to children younger than 5 years in settings of low socioeconomic development. However, efforts should also be targeted to other conditions, particularly HIV, given its increased burden in older children and adolescents. Older children and adolescents also experience a large burden of communicable disease, further highlighting the need for efforts to extend beyond the first 5 years of life. Our analysis also identified substantial morbidity caused by communicable diseases affecting child and adolescent health across the world. FUNDING: The Australian National Health and Medical Research Council Centre for Research Excellence for Driving Investment in Global Adolescent Health and the Bill & Melinda Gates Foundation

    Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin

    The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

    The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

    The effectiveness of domestic Scientific research on Iran development Indicators

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    In recent decades, research has growth Increasingly in Iran and, consequently, the country has risen dramatically in world rankings, based on the number of scientific documents. Meanwhile, research policy makers of different societies have concentrated, more and more, on "the effectiveness of researches" and today, their main concern is to ensure that researches are truly contributing to achieve development goals. The issue of "use of research to improve society" has also been emphasized by Iran high-ranking managers and consultants in superior governmental documents, implying their agreement on the importance and necessity of it. Experts' view about the necessity for science to play a fundamental role in the process of society improvement, research impact assessment specialists' models in which they directly emphasize on "promotion of development scale" as the research final expected effect, and the proven high correlation between scientific progress and economic development of societies, create a reasonable expectation that as a consequent of "remarkable progress in research", Iran has experienced a tangible improvement in other aspects and this improvement has been reflected in development indicators. This expectation leads to a question which has been the main reason for this study to be implemented. The purpose of this study is to examine the effectiveness of Iran increasingly research growth in recent three decades on the country development. The study uses a Descriptive-Analytical method and valid secondary data have been the base of analyses. At first, the reliable development indicators for which data were available for a number of countries in an appropriate timeframe were selected. Next, the rank of Iran determined in any indicator among 215 countries (based on the number of countries in World Bank Web site). Then, the trend of Iran's research position was compared with the trend of Iran's position in terms of each development indicator. Results showed that despite a seventy step improvement in research quantity during past 31 years, Iran position have declined 6 steps in terms of GDP per capita during 25 years, 43 steps in terms of inflation rate during 35 years, and 7 steps based on Ecological Footprint Index during 19 years. In other words, Iran hasn’t experienced an acceptable improvement in development level which could be seen as the consequence of its remarkable growth in research. As a conclusion, a shift in all Iran research stakeholders' perspective is necessary from "quantity-oriented view" to "impact-oriented view"

    The efficacy of Iran increasing researches in the country development

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    In recent decades, research has grown increasingly in Iran and consequently, the country has risen dramatically in world rankings based on the number of scientific documents. However, there are many evidences that show these researches were ineffective. Therefore, their efficacy should be evaluated which is the main purpose of this study. In this regard, using the descriptive-analytical method and valid secondary data and statistics, the most recent situation or the trend of impact pathway components (from investment to development) were compared with other countries. The required data were extracted from valid databases including UNESCO, World Bank, OECD, Thomson Reuters, SCImago, Islamic Parliament Research Center, National Iranian Productivity Organization, Harvard University, Massachusetts Institute of Technology (MIT), and Enerdata. The necessary calculations and rankings were done using Excel 2007. The results showed that, first, compared with other countries, Iran hasn’t given high priority to research and isn’t in a serious way to address this matter because in 2010 it ranked 66 (among 89 countries) based on share of R&D expenditure in GDP, 54 (among 88 countries) based on R&D expenditure per capita, 57 (among 72 countries) based on R&D expenditure per researcher, 79 (among 89 countries) based on average investment per research, and in 2000 it ranked 19 (among 21 countries) based on share of basic research in total R&D expenditure. Second, apart from the period leading to 2006, despite an impressive growth in research quantity, Iran share of High Technology products in industrial export shows deterioration. Third, during 1980-2014 Iran Economy Complexity Index has always been negative and placed among third weakest countries. Forth, despite a unique growth in science production, Iran couldn’t increase its total factor productivity and has fallen dramatically in world rankings based on energy intensity and GDP per unit of energy used. Therefore, according to the results of current and preceding studies, it is clear that even if there is no external deterrent, these researches cannot still play a tangible role in Iran development

    Differentiation of human endometrial stem cells into endothelial-like cells on gelatin/chitosan/bioglass nanofibrous scaffolds

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    The capacity of gelatin/chitosan/bioactive glass nanopowders (GEL/CS/BGNPs) scaffolds was investigated for increasing human endometrial stem cells (hEnSCs) differentiation into the endothelial cells in the presence of angiogenic factors. GEL/CS nanofibrous scaffold with different contents of BGNPs were fabricated and assessed. Expression of endothelial markers (CD31, vascular endothelial cadherin (VE-cadherin), and KDR) in differentiated cells was evaluated. Results showed the diameter of nanofiber increases with decreasing

    Immunology and Genetic of Leishmania infantum: The Role of Endonuclease G in the Apoptosis

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    Leishmania infantum is the causative agent of infantile visceral leishmaniasis (VL) in the Mediterranean region. Despite developing protective responses, the disease progresses due to many of factors. These include the action of suppressive cytokines, exhaustion of specific T cells, loss of lymphoid tissue, and defective humoral response. Genetic changes that occur inside the genome of alienated or parasite cells, along with immune responses, play an important role in controlling or progressing the disease. Proapoptotic proteins such as Smac/DIABLO, EndoG, AIF (apoptosis-inducing factor), and cytochrome C are effective in apoptosis. EndoG is a mitochondrion-specific nuclease that translocates to the nucleus during apoptosis. Once released from mitochondria, endoG cleaves chromatin DNA into nucleosomal fragments independently of caspases. Therefore, endoG represents a caspase-independent apoptotic pathway initiated from the mitochondria. A comprehensive understanding of the immune and genetic events that occur during VL is very important for designing immunotherapy strategies and developing effective vaccines for disease prevention. In this review which explained the immunological responses and also the important factors that can contribute to parasite apoptosis and are used in subsequent studies as a target for the preparation of drugs or recombinant vaccines against parasites are briefly reviewed
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