88 research outputs found

    Stable<i> trans</i> isomer as the kinetic and theromodynamic product for the oxidative addition of MeI to cycloplatinated(II) complexes comprising isocyanide ligands

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    The present investigation introduces a new series of cycloplatinated(II) complexes, with the general formula Pt(O-bpy)(Me)(CN-R)] (R = benzyl, 2-naphtyl and tert-butyl), which are able to generate the stable trans-Pt(IV) product in the solution after the reaction with iodomethane. In fact, the trans product is both the kinetic and thermodynamic product of the reaction; this observation was supported by DFT calculations. These Pt(II) complexes are supported by 2,2'-bipyridine N-oxide (O-bpy) and one of several isocyanides as the cyclometalated and ancillary ligands, respectively. These new Pt(II) complexes undergo oxidative addition with MeI to give the corresponding trans-Pt(IV) complexes. All the complexes were identified employing the multi-nuclear NMR spectroscopy and single crystal X-ray crystallography. The kinetic investigations were also performed for the oxidative addition reactions in order to measure the reaction rates; the reaction was followed by UV-Vis spectroscopy. The rates obtained follow the trend CN-tBu &gt; CN-Bz &gt; CN-2 Np for the CN-R ligands in the Pt(II) complexes. The order can be related to the degree of electron-donation of the R group (tert-butyl &gt; benzyl &gt; 2-naphtyl).</p

    Stable<i> trans</i> isomer as the kinetic and theromodynamic product for the oxidative addition of MeI to cycloplatinated(II) complexes comprising isocyanide ligands

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    The present investigation introduces a new series of cycloplatinated(II) complexes, with the general formula Pt(O-bpy)(Me)(CN-R)] (R = benzyl, 2-naphtyl and tert-butyl), which are able to generate the stable trans-Pt(IV) product in the solution after the reaction with iodomethane. In fact, the trans product is both the kinetic and thermodynamic product of the reaction; this observation was supported by DFT calculations. These Pt(II) complexes are supported by 2,2'-bipyridine N-oxide (O-bpy) and one of several isocyanides as the cyclometalated and ancillary ligands, respectively. These new Pt(II) complexes undergo oxidative addition with MeI to give the corresponding trans-Pt(IV) complexes. All the complexes were identified employing the multi-nuclear NMR spectroscopy and single crystal X-ray crystallography. The kinetic investigations were also performed for the oxidative addition reactions in order to measure the reaction rates; the reaction was followed by UV-Vis spectroscopy. The rates obtained follow the trend CN-tBu &gt; CN-Bz &gt; CN-2 Np for the CN-R ligands in the Pt(II) complexes. The order can be related to the degree of electron-donation of the R group (tert-butyl &gt; benzyl &gt; 2-naphtyl).</p

    The relationship between entrepreneurship components and communication skills of managers: a structural equation modeling

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    Background: The purpose of this study was to look into how managerial integrity and the elements of academic entrepreneurship relate to one another. Methods: This research was descriptive-correlational in nature. 1832 people made up the statistical population of the survey, including management, staff, and faculty from Islamic Azad Universities in District 6. 315 individuals that were chosen using stratified random sampling made up the estimated sample size. Data collection method was an academic entrepreneurship questionnaire that included 23 questions and a managers’ good character questionnaire that included 26 questions. By using exploratory factor analysis, the dimensions of academic entrepreneurship were discovered, and the internal validity of the questionnaires was confirmed by Cronbach's alpha (higher than 0.7). Results: The elements of academic entrepreneurship (organizational competencies, continuous contact, university aims and policies, entrepreneurial marketing, and culture) and the positive and substantial path coefficient (p = 0.001) were found to be significantly correlated. Conclusion: The change in educational quality and the investigation of the effective parameters for encouraging entrepreneurship in academic settings were the key factors in increasing the willingness for entrepreneurship. If the willingness for entrepreneurship was associated with a good character, it can have positive results and effectiveness that can be used by managers

    Reactivity of a new aryl cycloplatinated(ii) complex containing rollover 2,2′-bipyridine:<i>N</i> -oxide toward a series of diphosphine ligands

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    A new rollover cycloplatinated(ii) complex was prepared. The reactivity of this complex was investigated towards a wide range of diphosphine ligands.</p

    Prioritizing the Effective Components on Motivation of Employee Staff in Rafsanjan University of Medical Sciences using TOPSIS Technique

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    Background: Motivation is an intrusive force that leads individuals physiologically and psychologically to pursue their goals to meet their needs and expectations. Considering the importance of motivation in the health sector, this study aimed to prioritize the effective factors on staff motivation in Rafsanjan University of Medical Sciences. Methods: This is a descriptive-analytic study that was conducted in a cross-sectional fashion in 2016 on 222 staff members of Rafsanjan University of Medical Sciences who were selected by stratified random sampling method. A researcher-made questionnaire comprised of 40 questions in 11 dimensions including salary, policy, occupational safety, environmental conditions, supervision and support, appreciation, job development, the nature of work, job responsibility, occupation, and communication was used to collect data. The TOPSIS and SPSS 21 software were used to analysze data. Results: There was a significant relation between education level and motivation, but there were no significant relations between age, employment status, and career path and motivation. Also, the results of ranking the options indicated that the communication option with (0.74%) had the highest priority and the appreciation option with (0.29%) had the least priority in motivational factors. Conclusion: Since communication in this study was the most important among the motivational factors of the employee staff, it is suggested that managers develop a sense of trust and friendship between management and employees through facilitating and expanding vertical communication in order to increase motivation among employee staff. Keywords: Motivation, Employee Staff, Medical University, Prioritize, TOPSIS techniqu

    High-Voltage Pulse Generators for Electroporation Applications: A Systematic Review

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    In recent years, the use of electroporation process has attracted much attention, due to its application in various industrial and medical fields. Electroporation is a microbiology technique which creates tiny holes in the cell membrane by the applied electric field. The electroporation process needs high-voltage pulses to provide the required electric field. To generate high-voltage pulses, a pulse generator device must be used. High-voltage pulse generators can be mainly divided into two major groups: Classical pulse generators and power electronics-based pulse generators. As their name suggests, the first group is associated with the primary and elementary pulse generators like Marx generators, and the second group is associated with the pulse generators that have been updated with the advancement of power electronics like Modular Multilevel Converters. These two major groups are also divided into several subgroups which are reviewed in detail in this paper. This study reviews the literature presented in the field of pulse power and pulse generators proper for the electroporation process and addresses their strengths and weaknesses. Several tables are provided to highlight and discuss the characteristics of each subgroup. Finally, a comparative study among different groups of pulse generators is performed which is followed by a classification performance analysis

    An Overview on the Treatment and Management of the Desalination Brine Solution

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    Due to the increasing limitations of water resources, application of desalination plants is expanding. One of the constraints associated with desalination plant operation is the production of concentrated solution, which is known as brine and can lead to critical challenges in the environment due to its high level of salinity. In this regard, many different disposal options used recently to control and prevent the environmental issues may be caused by the brine. Evaporation ponds, surface water discharge, and deep well injection are considered as the most well-known options to properly dispose concentrated brine. However, the application of these methods is highly restricted by capital cost and their limited uses. The treatment methods vary in terms of their ability in organics removal and can be divided into three different conventional groups as biological, physicochemical, and oxidation. In recent years, more attention has been paid to membrane-based technologies due to their economic performance in recovering precious resources and providing potable water with high recovery rates. This book chapter provides some critical reviews on recent technologies including treatment operations and disposal options to manage concentrated solutions from desalination plants. Finally, electrodialysis, forward osmosis, and membrane distillation as emerging membrane processes are examined in this chapter

    Global, regional, and national burden of Alzheimer's disease and other dementias, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016.

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    BACKGROUND: The number of individuals living with dementia is increasing, negatively affecting families, communities, and health-care systems around the world. A successful response to these challenges requires an accurate understanding of the dementia disease burden. We aimed to present the first detailed analysis of the global prevalence, mortality, and overall burden of dementia as captured by the Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study 2016, and highlight the most important messages for clinicians and neurologists. METHODS: GBD 2016 obtained data on dementia from vital registration systems, published scientific literature and surveys, and data from health-service encounters on deaths, excess mortality, prevalence, and incidence from 195 countries and territories from 1990 to 2016, through systematic review and additional data-seeking efforts. To correct for differences in cause of death coding across time and locations, we modelled mortality due to dementia using prevalence data and estimates of excess mortality derived from countries that were most likely to code deaths to dementia relative to prevalence. Data were analysed by standardised methods to estimate deaths, prevalence, years of life lost (YLLs), years of life lived with disability (YLDs), and disability-adjusted life-years (DALYs; computed as the sum of YLLs and YLDs), and the fractions of these metrics that were attributable to four risk factors that met GBD criteria for assessment (high body-mass index [BMI], high fasting plasma glucose, smoking, and a diet high in sugar-sweetened beverages). FINDINGS: In 2016, the global number of individuals who lived with dementia was 43·8 million (95% uncertainty interval [UI] 37·8-51·0), increased from 20.2 million (17·4-23·5) in 1990. This increase of 117% (95% UI 114-121) contrasted with a minor increase in age-standardised prevalence of 1·7% (1·0-2·4), from 701 cases (95% UI 602-815) per 100 000 population in 1990 to 712 cases (614-828) per 100 000 population in 2016. More women than men had dementia in 2016 (27·0 million, 95% UI 23·3-31·4, vs 16.8 million, 14.4-19.6), and dementia was the fifth leading cause of death globally, accounting for 2·4 million (95% UI 2·1-2·8) deaths. Overall, 28·8 million (95% UI 24·5-34·0) DALYs were attributed to dementia; 6·4 million (95% UI 3·4-10·5) of these could be attributed to the modifiable GBD risk factors of high BMI, high fasting plasma glucose, smoking, and a high intake of sugar-sweetened beverages. INTERPRETATION: The global number of people living with dementia more than doubled from 1990 to 2016, mainly due to increases in population ageing and growth. Although differences in coding for causes of death and the heterogeneity in case-ascertainment methods constitute major challenges to the estimation of the burden of dementia, future analyses should improve on the methods for the correction of these biases. Until breakthroughs are made in prevention or curative treatment, dementia will constitute an increasing challenge to health-care systems worldwide

    Prevalence and attributable health burden of chronic respiratory diseases, 1990–2017: A systematic analysis for the global burden of disease study 2017

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    © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license Background: Previous attempts to characterise the burden of chronic respiratory diseases have focused only on specific disease conditions, such as chronic obstructive pulmonary disease (COPD) or asthma. In this study, we aimed to characterise the burden of chronic respiratory diseases globally, providing a comprehensive and up-to-date analysis on geographical and time trends from 1990 to 2017. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, we estimated the prevalence, morbidity, and mortality attributable to chronic respiratory diseases through an analysis of deaths, disability-adjusted life-years (DALYs), and years of life lost (YLL) by GBD super-region, from 1990 to 2017, stratified by age and sex. Specific diseases analysed included asthma, COPD, interstitial lung disease and pulmonary sarcoidosis, pneumoconiosis, and other chronic respiratory diseases. We also assessed the contribution of risk factors (smoking, second-hand smoke, ambient particulate matter and ozone pollution, household air pollution from solid fuels, and occupational risks) to chronic respiratory disease-attributable DALYs. Findings: In 2017, 544·9 million people (95% uncertainty interval [UI] 506·9–584·8) worldwide had a chronic respiratory disease, representing an increase of 39·8% compared with 1990. Chronic respiratory disease prevalence showed wide variability across GBD super-regions, with the highest prevalence among both males and females in high-income regions, and the lowest prevalence in sub-Saharan Africa and south Asia. The age-sex-specific prevalence of each chronic respiratory disease in 2017 was also highly variable geographically. Chronic respiratory diseases were the third leading cause of death in 2017 (7·0% [95% UI 6·8–7·2] of all deaths), behind cardiovascular diseases and neoplasms. Deaths due to chronic respiratory diseases numbered 3 914 196 (95% UI 3 790 578–4 044 819) in 2017, an increase of 18·0% since 1990, while total DALYs increased by 13·3%. However, when accounting for ageing and population growth, declines were observed in age-standardised prevalence (14·3% decrease), age-standardised death rates (42·6%), and age-standardised DALY rates (38·2%). In males and females, most chronic respiratory disease-attributable deaths and DALYs were due to COPD. In regional analyses, mortality rates from chronic respiratory diseases were greatest in south Asia and lowest in sub-Saharan Africa, also across both sexes. Notably, although absolute prevalence was lower in south Asia than in most other super-regions, YLLs due to chronic respiratory diseases across the subcontinent were the highest in the world. Death rates due to interstitial lung disease and pulmonary sarcoidosis were greater than those due to pneumoconiosis in all super-regions. Smoking was the leading risk factor for chronic respiratory disease-related disability across all regions for men. Among women, household air pollution from solid fuels was the predominant risk factor for chronic respiratory diseases in south Asia and sub-Saharan Africa, while ambient particulate matter represented the leading risk factor in southeast Asia, east Asia, and Oceania, and in the Middle East and north Africa super-region. Interpretation: Our study shows that chronic respiratory diseases remain a leading cause of death and disability worldwide, with growth in absolute numbers but sharp declines in several age-standardised estimators since 1990. Premature mortality from chronic respiratory diseases seems to be highest in regions with less-resourced health systems on a per-capita basis. Funding: Bill & Melinda Gates Foundation

    Prevalence and attributable health burden of chronic respiratory diseases, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017

    Get PDF
    Background Previous attempts to characterise the burden of chronic respiratory diseases have focused only on specific disease conditions, such as chronic obstructive pulmonary disease (COPD) or asthma. In this study, we aimed to characterise the burden of chronic respiratory diseases globally, providing a comprehensive and up-to-date analysis on geographical and time trends from 1990 to 2017. Methods Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, we estimated the prevalence, morbidity, and mortality attributable to chronic respiratory diseases through an analysis of deaths, disability-adjusted life-years (DALYs), and years of life lost (YLL) by GBD super-region, from 1990 to 2017, stratified by age and sex. Specific diseases analysed included asthma, COPD, interstitial lung disease and pulmonary sarcoidosis, pneumoconiosis, and other chronic respiratory diseases. We also assessed the contribution of risk factors (smoking, second-hand smoke, ambient particulate matter and ozone pollution, household air pollution from solid fuels, and occupational risks) to chronic respiratory disease-attributable DALYs. Findings In 2017, 544.9 million people (95% uncertainty interval [UI] 506.9- 584.8) worldwide had a chronic respiratory disease, representing an increase of 39.8% compared with 1990. Chronic respiratory disease prevalence showed wide variability across GBD super-regions, with the highest prevalence among both males and females in high-income regions, and the lowest prevalence in sub-Saharan Africa and south Asia. The age-sex- specific prevalence of each chronic respiratory disease in 2017 was also highly variable geographically. Chronic respiratory diseases were the third leading cause of death in 2017 (7.0% [95% UI 6.8-7 .2] of all deaths), behind cardiovascular diseases and neoplasms. Deaths due to chronic respiratory diseases numbered 3 914 196 (95% UI 3 790 578-4 044 819) in 2017, an increase of 18.0% since 1990, while total DALYs increased by 13.3%. However, when accounting for ageing and population growth, declines were observed in age-standardised prevalence (14.3% decrease), agestandardised death rates (42.6%), and age-standardised DALY rates (38.2%). In males and females, most chronic respiratory disease-attributable deaths and DALYs were due to COPD. In regional analyses, mortality rates from chronic respiratory diseases were greatest in south Asia and lowest in sub-Saharan Africa, also across both sexes. Notably, although absolute prevalence was lower in south Asia than in most other super-regions, YLLs due to chronic respiratory diseases across the subcontinent were the highest in the world. Death rates due to interstitial lung disease and pulmonary sarcoidosis were greater than those due to pneumoconiosis in all super-regions. Smoking was the leading risk factor for chronic respiratory disease-related disability across all regions for men. Among women, household air pollution from solid fuels was the predominant risk factor for chronic respiratory diseases in south Asia and sub-Saharan Africa, while ambient particulate matter represented the leading risk factor in southeast Asia, east Asia, and Oceania, and in the Middle East and north Africa super-region. Interpretation Our study shows that chronic respiratory diseases remain a leading cause of death and disability worldwide, with growth in absolute numbers but sharp declines in several age-standardised estimators since 1990. Premature mortality from chronic respiratory diseases seems to be highest in regions with less-resourced health systems on a per-capita basis
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