81 research outputs found

    Diseño de un algoritmo de minería metaheurístico para separar puntos de dos colores en un entorno bidimensional

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    The separation of color points is one of the important issues in computational geometry, which is used in various parts of science; it can be used in facility locating, image processing and clustering. Among these, one of the most widely used computational geometry in the real-world is the problem of covering and separating points with rectangles. In this paper, we intend to consider the problemof separating the two-color points sets, using three rectangles. In fact, our goal is to separate desired blue points from undesired red points by three rectangles, in such a way that these three rectangles contain the most desire points. For this purpose, we provide a metaheuristic algorithm based on the simulated annealing method that could separates blue points from input points, , in time order O (n) with the help of three rectangles. The algorithm is executed with C# and also it has been compared and evaluated with the optimum algorithm results. The results show that our recommended algorithm responses is so close to optimal responses, and also in some cases we obtains the exact optimal response

    AN IMPACT-BASED PIEZOELECTRIC ENERGY HARVESTER UTILIZING SPHERICAL MASS COLLISION PHENOMENON

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    The base-excitation piezoelectric energy harvesters have been vastly investigated under periodic base excitation as a conventional method. However, the waveforms of environment’s vibrations are mostly non-harmonic low-frequency periodic signals that reduce the efficiency of the harmonic-based resonance harvester. This study presents an alternative piezoelectric energy generation, the impact-based piezoelectric energy harvester concept rather than the typical harmonic-based one. The harvester benefits from impact excitation, leading to higher frequencies around the harvester’s natural frequencies. The impact concept is utilized for energy harvesting based on contact between a piezoelectric patch and a miniatured spherical mass. An experimental study was carried out to evaluate the effects of impact velocity and boundary condition on the dynamic behavior and power generation of the piezoelectric energy harvester. Moreover, a finite element model implemented a feasible framework to investigate the output power of the energy harvester under various impact forces. The results demonstrated μJ-scale energy generation by a single impact, indicating great energy generation possibilities for ultra-low-frequencies. The results also indicated that the boundary condition plays a critical role in energy harvesting, affecting the probability of voltage cancelation phenomenon occurrence. It was shown that the optimal boundary condition decreases the negative effects of voltage cancelation to improve the performance of the impact-based energy harvester

    Energy Harvester based on Piezoelectric Impact Compartment

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    Antioxidant and toxicity studies of biosynthesized cerium oxide nanoparticles in rats

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    Funding Information: We would like to thank the Vice Chancellery for Research and Technology, MUMS for financial support (grant no 930954) and facilities.Peer reviewedPublisher PD

    بررسي ميزان آلودگي جيوه در خاك شهرك هاي صنعتي اراك

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    Background and Aims: Mercury is generally considered one of the most toxic heavy metals that rapid industrial development and industry uses of mercury cause accumulation of mercury in soil. The purpose of this study was to investigate the concentration and degree of mercury pollution in topsoil of three major industrial estates of Arak city.Materials and Methods: In this study three estates was investigated. Soil samples were collected from thedepth of 0 to 20 cm . 22 samples were taken and analyzed. Mercury concentrations in soil samples were determined by Advanced Mercury Analyzer (Model; Leco, AMA 254).Results: The mercury concentrations in soil samples range from 68.43 to 137.03 μg/ kg for soils, with a mean value of 102.07 μg/ kg. Means comparison showed significant difference among industrial town 2 with other industrial towns .Also there was no significant correlation between soil pH and Hg concentration.Conclusion: The result of this research showed that: Compared to earth crust, surface soils in industrial towns had higher mercury concentrations, but compared to other soils around the world, it did not show high levels of mercury and it seems that most of the sources of mercury pollution are natural. Despite the concentration of total Hg in soils are not acute, however the planning for emission control of this metal and other pollutants, with application of green plants purification technology should be considered seriously.زمينه و هدف: جيوه يکي از سمی ترين فلزات سنگين م يباشد که توسعه سريع صنعتي و استفاد ههاي صنعتي از اين فلز سبب تجمع آندر خاک می شود. اين تحقيق با هدف تعيين مقادير و درجه آلودگي جيوه در خاک سطحي سه شهرک صنعتي عمده واقع در شهر اراکصورت گرفت.مواد و رو شها: در اين مطالعه سه شهرك مورد بررسي قرار گرفت. نمونه ها از عمق ۰ تا ۲۰ سانت يمتري خاک شهر کهاي مورد مطالعهجمع آوري شدند. تعداد ۲۲ نمونه مركب مورد آزمايش قرار گرفت. یافته ها: در این مطالعه غلظت جیوه کل در خاک در محدوده68/43 تا 137/03 مبکروگرم بر کیلوگرم با میانگین102/07 میکروگرم بر کیلوگیرم تعسسن شد. مقایسه میانگین ها اختلاف معنی داری بین شهرک 2 با سابر شهرک ها نشان داد. نتيجه گيري: يافت ههاي پژوهش نشان داد که مقادير جيوه کل در خاک در مقايسه با مقادير پوسته زمين بالاتر بود اما در مقايسه با محدودهآن در خا کهاي جهان مقادير كمي بالاتر است. هر چند غلظت اين آلاينده در منطقه مورد مطالعه حاد نمي باشد ولي برنامه ريزي جهتكنترل انتشار اين فلز و آلايند ههاي ديگر بايد مورد توجه جدي قرار گيرد. همچنين كاربرد فن آوري سبز گياه پالايي به عنوان روش جديدجهت رفع آلودگي خاک مورد استفاده قرار گيرد

    Glucoherb versus metformin on glycemic markers and glycosylated hemoglobin in prediabetes patients; a clinical trial study

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    Introduction: There is a high risk of diabetes mellitus in pre-diabetic patients. Objectives: The aim of the study was to compare the effect of the extracts of these herbs in the formulation of Glucoherb supplementation versus metformin in pre-diabetes patients on glycemic markers and glycosylated hemoglobin. Patients and Methods: Pre-diabetic patients who had indication of drug treatment according to the criteria of the American Diabetes Association, were selected and randomly divided into two groups of Glucoherb and metformin. Body mass index (BMI), fasting blood sugar (FBS), 2 hours postprandial blood glucose (BS2PP) and glycosylated hemoglobin (HbA1c) were measured before and after the intervention. Results: The mean BMI, FBS, BS2PP and HbA1c levels were significantly decreased after intervention in both Glucoherb and metformin groups (P < 0.05) without any significant difference between them (P < 0.05). Conclusion: Glucoherb showed similar efficacy to metformin in reducing blood glucose, BMI and HbA1c in pre-diabetic patients

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

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    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

    Effect of Intermediate-Dose vs Standard-Dose Prophylactic Anticoagulation on Thrombotic Events, Extracorporeal Membrane Oxygenation Treatment, or Mortality among Patients with COVID-19 Admitted to the Intensive Care Unit: The INSPIRATION Randomized Clinical Trial

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    Importance: Thrombotic events are commonly reported in critically ill patients with COVID-19. Limited data exist to guide the intensity of antithrombotic prophylaxis. Objective: To evaluate the effects of intermediate-dose vs standard-dose prophylactic anticoagulation among patients with COVID-19 admitted to the intensive care unit (ICU). Design, Setting, and Participants: Multicenter randomized trial with a 2 � 2 factorial design performed in 10 academic centers in Iran comparing intermediate-dose vs standard-dose prophylactic anticoagulation (first hypothesis) and statin therapy vs matching placebo (second hypothesis; not reported in this article) among adult patients admitted to the ICU with COVID-19. Patients were recruited between July 29, 2020, and November 19, 2020. The final follow-up date for the 30-day primary outcome was December 19, 2020. Interventions: Intermediate-dose (enoxaparin, 1 mg/kg daily) (n = 276) vs standard prophylactic anticoagulation (enoxaparin, 40 mg daily) (n = 286), with modification according to body weight and creatinine clearance. The assigned treatments were planned to be continued until completion of 30-day follow-up. Main Outcomes and Measures: The primary efficacy outcome was a composite of venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days, assessed in randomized patients who met the eligibility criteria and received at least 1 dose of the assigned treatment. Prespecified safety outcomes included major bleeding according to the Bleeding Academic Research Consortium (type 3 or 5 definition), powered for noninferiority (a noninferiority margin of 1.8 based on odds ratio), and severe thrombocytopenia (platelet count &lt;20 �103/µL). All outcomes were blindly adjudicated. Results: Among 600 randomized patients, 562 (93.7) were included in the primary analysis (median interquartile range age, 62 50-71 years; 237 42.2% women). The primary efficacy outcome occurred in 126 patients (45.7%) in the intermediate-dose group and 126 patients (44.1%) in the standard-dose prophylaxis group (absolute risk difference, 1.5% 95% CI,-6.6% to 9.8%; odds ratio, 1.06 95% CI, 0.76-1.48; P =.70). Major bleeding occurred in 7 patients (2.5%) in the intermediate-dose group and 4 patients (1.4%) in the standard-dose prophylaxis group (risk difference, 1.1% 1-sided 97.5% CI,-� to 3.4%; odds ratio, 1.83 1-sided 97.5% CI, 0.00-5.93), not meeting the noninferiority criteria (P for noninferiority &gt;.99). Severe thrombocytopenia occurred only in patients assigned to the intermediate-dose group (6 vs 0 patients; risk difference, 2.2% 95% CI, 0.4%-3.8%; P =.01). Conclusions and Relevance: Among patients admitted to the ICU with COVID-19, intermediate-dose prophylactic anticoagulation, compared with standard-dose prophylactic anticoagulation, did not result in a significant difference in the primary outcome of a composite of adjudicated venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days. These results do not support the routine empirical use of intermediate-dose prophylactic anticoagulation in unselected patients admitted to the ICU with COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04486508. © 2021 American Medical Association. All rights reserved

    Prevalence and Correlates of Psychiatric Disorders in a National Survey of Iranian Children and Adolescents

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    Objective: Considering the impact of rapid sociocultural, political, and economical changes on societies and families, population-based surveys of mental disorders in different communities are needed to describe the magnitude of mental health problems and their disabling effects at the individual, familial, and societal levels. Method: A population-based cross sectional survey (IRCAP project) of 30 532 children and adolescents between 6 and 18 years was conducted in all provinces of Iran using a multistage cluster sampling method. Data were collected by 250 clinical psychologists trained to use the validated Persian version of the semi-structured diagnostic interview Kiddie-Schedule for Affective Disorders and Schizophrenia-PL (K-SADS-PL). Results: In this national epidemiological survey, 6209 out of 30 532 (22.31%) were diagnosed with at least one psychiatric disorder. The anxiety disorders (14.13%) and behavioral disorders (8.3%) had the highest prevalence, while eating disorders (0.13%) and psychotic symptoms (0.26%) had the lowest. The prevalence of psychiatric disorders was significantly lower in girls (OR = 0.85; 95% CI: 0.80-0.90), in those living in the rural area (OR = 0.80; 95% CI: 0.73-0.87), in those aged 15-18 years (OR = 0.92; 95% CI: 0.86-0.99), as well as that was significantly higher in those who had a parent suffering from mental disorders (OR = 1.96; 95% CI: 1.63-2.36 for mother and OR = 1.33; 95% CI: 1.07-1.66 for father) or physical illness (OR = 1.26; 95% CI: 1.17-1.35 for mother and OR = 1.19; 95% CI: 1.10-1.28 for father). Conclusion: About one fifth of Iranian children and adolescents suffer from at least one psychiatric disorder. Therefore, we should give a greater priority to promoting mental health and public health, provide more accessible services and trainings, and reduce barriers to accessing existing services

    Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

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    Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49·4% (95% uncertainty interval [UI] 46·4–52·0). The TFR decreased from 4·7 livebirths (4·5–4·9) to 2·4 livebirths (2·2–2·5), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83·8 million people per year since 1985. The global population increased by 197·2% (193·3–200·8) since 1950, from 2·6 billion (2·5–2·6) to 7·6 billion (7·4–7·9) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2·0%; this rate then remained nearly constant until 1970 and then decreased to 1·1% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2·5% in 1963 to 0·7% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2·7%. The global average age increased from 26·6 years in 1950 to 32·1 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59·9% to 65·3%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1·0 livebirths (95% UI 0·9–1·2) in Cyprus to a high of 7·1 livebirths (6·8–7·4) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0·08 livebirths (0·07–0·09) in South Korea to 2·4 livebirths (2·2–2·6) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0·3 livebirths (0·3–0·4) in Puerto Rico to a high of 3·1 livebirths (3·0–3·2) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2·0% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress
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