24 research outputs found

    Glass formation and meltability of metal-organic frameworks

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    Melt-quenched (MQ) glasses derived from metal-organic frameworks (MOFs) have emerged very recently as tunable organic-inorganic hybrid glasses, showing potential applications in gas separation. Zeolitic imidazolate frameworks (ZIFs) are a subclass of MOFs which have shown high meltability. ZIF-62, a mixed-linker ZIF, has been investigated extensively because of its low melting temperature and high thermal stability. Application of glasses formed from MOFs on an industrial scale requires large-scale production of parent crystals. However, in large-scale production of mixed-linker MOFs, both kinetics and thermodynamics of synthesis play significant roles. The importance of both factors originates from a heterogeneous linker distribution in mixed-linker MOFs where each type of linker can form different crystalline phases during synthesis, altering thermal properties and more importantly, the meltability. The parameters which affect the formation of different crystalline polymorphs in ZIF-62, and the methods required to detect such structural heterogeneity in the final material are investigated, while possible phase transformations are also discussed. Among a huge number of crystalline MOFs (over 70,000), only small number of them have shown the ability to melt. Decomposition of the framework prior to its melting transition is an obstacle hindering the transition to the liquid state while heating. Porosity and metal-ligand interactions have been identified as parameters determining meltability of such frameworks. To overcome these constraints, an ionic liquid (IL) containing its sodium salt was incorporated into the cages of ZIF-8, a highly porous, normally non-meltable ZIF. After mechanical amorphization, the structure of the resultant composite and stability of IL molecules in the collapsed pores were examined, and the effect of structural collapse on ionic conduction, as a macroscopic property, was investigated

    Tunable broadband photoluminescence from bismuth‐doped calcium aluminum germanate glasses prepared in oxidizing atmosphere

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    Tunable photoluminescence (PL) from transparent inorganic glass matrices is of interest for applications demanding a semitransparent photoconverter that does not elastically scatter incoming light. For this purpose, bismuth (Bi)‐doped optical materials exhibit unique spectral characteristics in terms of bandwidth and emission tunability. Here, we demonstrate a facile route for preparing such converters from Bi‐doped calcium‐aluminate and calcium‐aluminogermanate glasses. These glasses offer tunable PL across the near violet and visible‐to‐near‐infrared (NIR) spectral range, with an emission lifetime in the range of 300 μs. The addition of GeO 2 exerts a decrease in optical basicity, which in turn enables the stabilization of NIR‐active low‐valence Bi species for broadband NIR PL

    Analysis of the sharing economy effect on sustainability in the transportation sector using Fuzzy cognitive mapping

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    Along with the significant growth of the sharing economy in recent years, its effect on the economy, society, and the environment at the level of governments, academic communities, and researchers has been widely discussed. One of the main debates is identifying the side or negative effects of the sharing economy as well as its positive effects. Studying the cause-effect relationship of the variables affecting sustainability in the sharing economy context can provide valuable results for firms. For this purpose, fuzzy cognitive maps have been used. Based on the literature review, the sharing economy's essential variables that affect sustainability were identified, and using the Fuzzy Delphi method, these variables were localized. Snapp and Tap30 were selected as two of the largest platforms in the Iranian transportation sector. Fuzzy cognitive maps based on aggregated opinions of experts were inputted to the Mental Modeler online software to drawn the cognitive map of this research. The degree of centrality index, i.e., the summation of input and output degree, was used to identify the most relevant sustainability variables. Consequently, the incentives to make a greater use of the platform, the income of drivers, the monopoly power of platforms, the price of services, the higher service quality of platforms, the use of private vehicles by passengers, and the change of traffic in cities were identified as variables with the greatest effect on stability. Four positive loops and one negative loop were identified among these seven variables in the cause-effect analysis. In the final section, some suggestions are presented based on each loop

    Research Records and Possibilities of the Department of Pharmacology Physiology in Kerman University of Medical Sciences, Iran

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    Background: The publication of information and possibilities of a university department and the experiences of its faculty members make others aware of these issues and can be regarded as one of the methods of publishing and teaching science. It seems that the report of research experiences, capabilities, and achievements in Department of Pharmacology Physiology, Kerman University of Medical Sciences, Iran, make it easier for further researches of other researchers. Methods: Data were obtained via observing, searching in valuable scientific databases and group archives, and asking the department manager, faculty members, and experts in Department of Pharmacology Physiology, as well as gathering the information in research centers of the university. Results: Department of Physiology and Pharmacology was the first group that initiated postgraduate and doctoral degrees’ courses at Kerman University of Medical Sciences. The annual per capita of paper production in this group was close to 7 with 10 faculty members. Three faculty members were among the first 15 of the university in terms of the H-index. The country, provincial, university, and faculty rankings achieved by the department, variety in research projects, and the collaborative studies in the university were the features of this department. The first and second research centers of the university in terms of history and rank were managed by faculty members of this department. Conclusion: Department of Pharmacology Physiology is one of the successful and high history departments in Kerman University of Medical Sciences. Other researchers can use the experience of these faculty members, and department facilities for their advancement. Keywords Physiology; research; Equipment; Department; Pharmacy facult

    Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021

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    Background: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions

    Genetic diversity of six isolated populations of the leopard moth, Zeuzera pyrina (Lep: Zeuzeridae)

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    The leopard moth, Zeuzera pyrina (Lep: Zeuzeridae), is an important pest of a wide range of trees and shrubs including walnut and apple across the world. The natural populations of the leopard moth in different geographical areas of Iran show significant differences in some of their biological characteristics such as time of emergence, generation time and host specificity. So, we hypothesized that these populations may represent different subspecies that move toward a speciation event in their evolutionary route. In this study, we evaluated the genetic diversity of six different geographically isolated populations of the leopard moth using the sequence alignment of cytochrome oxidase c subunit one (COI). A fragment of 642 base pairs was amplified in all six populations and the phylogenetic tree was created based on sequenced fragments. Our results revealed significant differences in the nucleotide sequence of COI gene in these populations. Differences in climatic conditions of these regions seem to be the most powerful force driving this diversity among the studied populations

    FIGURE 3 in A new bee fly species of the genus Phthiria (Diptera, Bombyliidae, Phthiriinae, Phthiriini) from the west of Iran

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    FIGURE 3. Genitalia of Phthiria portokali sp. nov, A) female genitalia; B) spermathecal; C) gonocoxae in dorsal view; D) gonostylus; E) phallic complex in dorsal view; F) epandrium in dorsal view.Published as part of <i>Farhangi, Seyed Vahid, Nozari, Jamasb & Gharali, Babak, 2023, A new bee fly species of the genus Phthiria (Diptera, Bombyliidae, Phthiriinae, Phthiriini) from the west of Iran, pp. 491-497 in Zootaxa 5380 (5)</i> on page 495, DOI: 10.11646/zootaxa.5380.5.6, <a href="http://zenodo.org/record/10254481">http://zenodo.org/record/10254481</a&gt
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