38 research outputs found
Optimization of lipid production in Chlorella vulgaris for biodiesel production using flux balance analysis
The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.bej.2018.10.011 © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Microalgae, the worldâs largest group of photosynthetic organisms, convert atmospheric CO2 to polar and neutral lipids using sunlight, which after esterification can be utilized for biodiesel production. In the present study, a fully compartmentalized metabolic network was developed to describe the metabolism of Chlorella vulgaris based on known enzymatic reactions and typical metabolic pathways of green algae. Flux balance analysis was employed to optimize the speciïŹc growth rate and the lipid production rate using measured exchange ïŹuxes of the metabolites. The experimental data for batch and fed batch algal fermentation systems acquired from the literature were used to validate the accuracy of the pseudo- steady state model. The physiological pathways of the microalgae for lipid biosynthesis were identified. The simulation revealed that the microalgae would be able to produce higher levels of lipid content (43.6%) during N-starvation cultivation under 100 ÎŒmol mâ2 sâ1 light intensity, 0.25 vvm aeration with 2% (v/v) CO2, 2 mg Lâ1 PO4-P, and 5 mg Lâ1 NO3-N. Sensitivity analysis showed that CO2, light energy, O2, and nitrate were the most important factors affecting the lipid production at N-deficient conditions. The findings consequential for manipulation of the metabolism of the microalgae with optimal activity.Ferdowsi university of Mashhadâs research center, Iran ["25902"]
Childhood overweight and obesity and associated factors in iranian children and adolescents : a multilevel analysis; the CASPIAN-IV Study
Epidemiology Study And Methods Of Suicide Under The Age Of 18 Years During 2010-2020 In Tehran Province
Background: Type of suicide is determined by various factors such as accessibility to drugs, economic problems and psychological disorders.
Objective: This study aimed to assess the epidemiology of suicide death, autopsy and effective factors in children<18 years.
Methods: This was a cross-sectional study carried out on 350 autopsy bodies less than 18 years of age in Tehran Forensic Medicine Center during 2010-2020 who had struggled with suicide. Data were analyzed using SPSS version 18.
Results: Mean age of children was 16.36±1.76 years. The most common method in children less than 15 years and over 15 years was hanging (n=36) and poisoning with chemical substance (n=139), respectively (p<0.001). The most common method of the suicide was poisoning with chemical substance (n=147, 42%). The most common method of suicide in girls and boys was poisoning with chemical substance (n=81) and hanging (n=75), respectively. The highest number of children struggled with were residents in the outskirt of Tehran (n=113, 32.5%). Suicide rate in people with depressive disorder and tentative injury was 10% (n=35) and 18.6% (n=65). In 13 patients, vitreous humor alcohol was positive (mean alcohol: 60.61±43.03 mg/dl). The most common toxin observed in toxicology was rice tablet or aluminum phosphide (n=90, 25.7%). Regarding drug toxicity in toxicology, 52.6% (n=86) was not positive. Opium was found 7.4% of cases (n=26).
Conclusion: The suicide rate has been on the rise during the past ten years through hanging and poisoning with chemical substance such as aluminum phosphide, opium and tricyclic antidepressants especially in outskirts
Increased Concentrations of Interleukinâ33 in the Serum and Cerebrospinal Fluid of Patients with Multiple Sclerosis
Objectives: Interleukin (IL)â33 is a cytokine with both pro- and anti-inflammatory
effects involved in the pathogenesis of some inflammatory diseases. The purpose of
this investigation was to evaluate the serum and cerebrospinal fluid (CSF) ILâ33
concentrations in patients with multiple sclerosis (MS). Methods: Blood specimens were
obtained from 140 patients with MS (46 males and 94 females) with various disease
patterns and treatment plans and 140 healthy subjects (47 males and 93 females), who acted
as a control group. CSF samples were collected from 20 MS group and 20 sex- and agematched
patients with other neurological diseases of nonautoimmune etiology. The serum
and CSF concentrations of ILâ33 were measured by the enzyme-linked immunosorbent
assay. Results: The serum and CSF ILâ33 levels were significantly higher in the MS group
compared to the control group (p<0.001 and p<0.050, respectively). The serum ILâ33
concentrations were also significantly higher in newly diagnosed (untreated) patients and
patients treated with methylprednisolone or with interferon-ÎČ and methylprednisolone
compared to the healthy patient group (p<0.007, p<0.002, and p<0.010, respectively).
Moreover, the serum ILâ33 concentrations in patients with relapsing-remitting (RRMS),
primary progressive (PPMS), and secondary progressive (SPMS) forms of the disease were
significantly higher than in the healthy control group (p<0.006, p<0.001, and p<0.020,
respectively). Conclusions: Our results showed increased concentrations of ILâ33 in
patients with MS including both untreated and treated MS patients and patients with
the RRMS, SPMS, and PPMS forms. This suggests that ILâ33 may be involved in the
pathogenesis of all MS forms and treatment with methylprednisolone or both interferon-ÎČ
plus methylprednisolone has no influence on ILâ33 concentrations
Mortality due to H1N1 Influenza in Cases Registered at the Autopsy Halls of Kahrizak, Tehran
H1N1 swine flu is an acute disease that infects the upper respiratory tract and can cause inflammation of the upper respiratory tract, trachea, and possibly the lower respiratory tract. The known course for H1N1 swine flu is varied from one to four days, on average for most people about two days, but in some cases, it can be up to seven day
Childhood Overweight and Obesity and Associated Factors in Iranian Children and Adolescents: A Multilevel Analysis; the CASPIAN-IV Study
Objective: The purpose of this paper is to explore multidimensional factors related to childhood obesity and overweight based on the data gathered on different aspects of the general health status were assessed among a large number of Iranian children and adolescents in the fourth phase of the âChildhood and Adolescence Surveillance and Prevention of Adult Non-communicable diseaseâ survey. It also aims to determine the degree to which each ecological context contributes to childhood overweight/obesity.Method: A total of 14,880 students and their parents were recruited. They filled out a questionnaire on their relationship with peers, body image, and psychosocial environment of school, dietary habits, life-style habits, physical activity pattern and socioeconomic status (SES). Their height, weight, was measured and body mass index (BMI) was calculated. Obesity and overweight was defined based on the WHO growth chart. Multilevel modeling using three-level random intercept logistic regression models were used to assess predictors of overweight and obesity. In our hierarchical models, children (first level) were conceptualized as being nested within provinces (second level) and provinces within quad regions (third level).Result: From among the 13,486 recruited students, 9.7% were overweight and 11.9% were obese. In multivariate model (adjusted model), being boy (OR:1.58), living in urban area (OR:1.58), having positive family history of obesity (OR = 2.04), breakfast skipping (OR: 1.46), socioeconomic status (OR moderateSES/lowSES = 1.44 and OR highSES/lowSES = 1.89), and birth weight (BW) (OR normalBW/lowBW = 1.33 and OR highBW/lowBW = 1.8) were associated with childhood obesity. Increasing age was the only factor in the obesity model that had a significant preventive effect on the odds of becoming obese (OR = 0.96, P < 0.001). In multivariate model, living in urban area, increasing age, high and moderate SES, high BW and family history of obesity were the significant predictors of overweight.Conclusion: Our findings show that high BW, sociodemographic characteristics, breakfast skipping, and family history of obesity are associated with childhood obesity and overweight. Therefore, developing strategies that consider the effects of diverse sociodemographic and environmental factors on childhood overweight and obesity would be the most effective way to prevent and manage this multifactorial health concern
Economic Inequality in Healthy and Junk Foods Consumption and its determinants in Children and Adolescents: the CASPIAN- IV Study
Background: Nutritional habits and its determinants, especially in children and adolescents have recently turned into the one of the major concerns of health researches. We examine the diet contribution inequality in according to socio-demographic factors, age, gender, physical activity and body image to alleviate this gap in Iranian children and adolescents. Materials and Methods: Study sample was comprised of 14,880 students aged 6-18 years who selected from urban and rural districts of 30 provinces of Iran via stratified multi-stage sampling method. A short food frequency questionnaire was used for estimating the food group consumption. The Blinder-Oaxaca method was applied to investigate the inequality in the prevalence of healthy and junk foods consumption between the first and fifth socio-economic status (SES) quintiles. Results: The frequency of healthy and junk foods consumption showed considerable differences between the SES quintiles. The highest differences were found in the frequency of fresh fruit (25.38%), vegetable (12.92%), and milk (10.74%) consumption, respectively. The daily consumption of vegetables, and fresh and dried fruits increased linearly by increasing the SES quintiles. The highest absolute difference was seen in the frequency of fresh fruit consumption between the bottom and top of the socioeconomic groups (SII value=-32%). The estimated SII was statistically significant for the consumption of all healthy and junk foods except for fast foods and milk consumption. The estimated C index for consumption of healthy and junk foods was positive and negative, respectively. Conclusion: This study provides the considerable information on the consumption of healthy and junk foods and its determinants among Iranian children and adolescents for better programming, developing health policies, and future complementary analyses
Establishing research impact assessment in Iran: The first report from a non-high-income country
Background This study presents the first report on research impact assessment (RIA) in non-high-income countries, undertaken as a pilot initiative in 2021. Within it, we aimed to explore the feasibility of employing the âpaybackâ model for evaluating the impact of health research and enhancing the accountability of universities. We focussed on three key impact domains: âproduction of decision support documents and knowledge-based products,â âimplementation of research results,â and âhealth and economic impact.â
Methods We adopted a case study approach to assess the impact of 5334 health research projects conducted by researchers from 18 universities from 2018 to 2020. Researchers were required to submit evidence related to at least one of the specified impact domains; six scientific committees verified and scored claimed impacts at the national level.
Results Only 25% of the assessed projects achieved impact in at least one domain, with the production of decision support documents and knowledge products being the most reported impact. Notably, economic impact was verified in only three projects, indicating room for improvement in this area. Technology research exhibited the highest acceptance rate of claimed impact, suggesting a positive correlation between technology-focused projects and impactful outcomes.
Conclusions This study demonstrates the feasibility of employing a case study approach and the âpaybackâ model to evaluate the impact of health research, even within the constraints of a moderately equipped research infrastructure. These findings underscore the potential of integrating RIA into the governance of health research in Iran and other non-high-income countries, as well as the importance of using RIA to assess the accountability of health research systems, guide the allocation of research funding, and advocate for the advancement of health research. The study sets a precedent for future assessments in similar contexts and contributes to the ongoing global dialogue on the societal impact of health research
Global burden of 369 diseases and injuries in 204 countries and territories, 1990â2019: a systematic analysis for the Global Burden of Disease Study 2019
Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990â2010 time period, with the greatest annualised rate of decline occurring in the 0â9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10â24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10â24 years were also in the top ten in the 25â49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50â74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019
Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019.
Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10â14 and 50â54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66â2·79) in 2000 to 2·31 (2·17â2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5â137·8) in 2000 to a peak of 139·6 million (133·0â146·9) in 2016. Global livebirths then declined to 135·3 million (127·2â144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4â27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8â67·6) in 2000 to 73·5 years (72·8â74·3) in 2019. The total number of deaths increased from 50·7 million (49·5â51·9) in 2000 to 56·5 million (53·7â59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1â10·3) in 2000 to 5·0 million (4·3â6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0â6·3) in 2000 to 7·7 billion (7·5â8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1â60·8) in 2000 to 63·5 years (60·8â66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019