Analyzing and studying educational pyramid and changes in demographical indices of Tehran students during the school years 2000-2010

One of the effective factors in planning is paying attention to the increase and decrease of student population. In this study, using a variety of resources, it has been attempted that the growth changes and population decrease in the student population of Tehran in a 10-year period and considering the measures such as population density in-class students, the educational staff ratio, academic pyramid, the separation of school, number of classes and other aspects will be dealt with. Obviously, the results and findings of this potential research could be used in educational planning and population policy. In the present study, the method of data collection was done using the quantitative techniques of demography and a variety of statistical calculations. The research findings showed that the student population, number of classes and schools and the staff of ministry of education are being significantly decreased and has been associated with a negative growth rate in all levels

Analyzing and studying educational pyramid and changes in demographical indices of Tehran students during the school years 2000-2010

One of the effective factors in planning is paying attention to the increase and decrease of student population. In this study, using a variety of resources, it has been attempted that the growth changes and population decrease in the student population of Tehran in a 10-year period and considering the measures such as population density in-class students, the educational staff ratio, academic pyramid, the separation of school, number of classes and other aspects will be dealt with. Obviously, the results and findings of this potential research could be used in educational planning and population policy. In the present study, the method of data collection was done using the quantitative techniques of demography and a variety of statistical calculations. The research findings showed that the student population, number of classes and schools and the staff of ministry of education are being significantly decreased and has been associated with a negative growth rate in all levels

Comparing the performance and problems of pre-school centers and kindergartens in Varamin city in Iran

The necessity to examine the performance and problems of pre-school course is due to the significant effect of this course in the child's growth. In this descriptive study, we used systematic perspective to survey and the statistical community is all the managers, coaches and parents of pre-school centers of Varamin in academic year of 2012-13 (2772 people). The sample size is 598 people, according to Morgan table collecting information has been done through observation, interviews, questionnaires and in library and validity of tool research was approved by the teachers and the coefficient of 941/0 = α was calculated, which is an indicative of appropriate stability. To analyze the data, descriptive and inferential statistics were used. The results indicated that there is a significant difference in performance and problems in preschool centers under the protection of education and welfare centers in the size of input, process and environment

Comparing the performance and problems of pre-school centers and kindergartens in Varamin city in Iran

The necessity to examine the performance and problems of pre-school course is due to the significant effect of this course in the child's growth. In this descriptive study, we used systematic perspective to survey and the statistical community is all the managers, coaches and parents of pre-school centers of Varamin in academic year of 2012-13 (2772 people). The sample size is 598 people, according to Morgan table collecting information has been done through observation, interviews, questionnaires and in library and validity of tool research was approved by the teachers and the coefficient of 941/0 = α was calculated, which is an indicative of appropriate stability. To analyze the data, descriptive and inferential statistics were used. The results indicated that there is a significant difference in performance and problems in preschool centers under the protection of education and welfare centers in the size of input, process and environment

Developing a new hydrogen liquefaction process through configuration modification and parameter optimization

A new concept for hydrogen liquefaction with a capacity of 300 tons per day is developed through the modification of an existing one. Pressure and temperature levels, mixed-refrigerant composition, and different configurations are explored to achieve a new concept with lower SEC and higher COP. Aspen HYSYS V9 is used to simulate the process. Exergy and energy analyses are employed for evaluating the process to capture the effect of changes. As different parameters of the liquefaction process are interlinked and depend on each other, optimization is done using a trial and error procedure. Modified-Benedict–Webb–Rubin and Peng-Robinson equations of state are utilized to simulate hydrogen and mixed refrigerant streams to increase the accuracy of the results, especially for the ortho-para conversion. Power consumption of the coolers is considered, and exergy destruction for all the components is calculated. It is found that ortho-para converters and separators could affect the total exergy destruction and efficiency of the process; however, their exergy efficiency is nearly 100%. The SEC of the new concept is 5.97 kWhr/kg, which shows an 18.8% improvement compared to the base concept. The COP and ε are improved by 14.4% and 15.5% too. The results show that the liquefaction section is responsible for 85% of the total SEC of the process, and it deserves to focus on this section for future studies

Comparing the performance and problems of pre-school centers and kindergartens in Varamin city in Iran

The necessity to examine the performance and problems of pre-school course is due to the significant effect of this course in the child's growth. In this descriptive study, we used systematic perspective to survey and the statistical community is all the managers, coaches and parents of pre-school centers of Varamin in academic year of 2012-13 (2772 people). The sample size is 598 people, according to Morgan table collecting information has been done through observation, interviews, questionnaires and in library and validity of tool research was approved by the teachers and the coefficient of 941/0 = α was calculated, which is an indicative of appropriate stability. To analyze the data, descriptive and inferential statistics were used. The results indicated that there is a significant difference in performance and problems in preschool centers under the protection of education and welfare centers in the size of input, process and environment

The Effect of Superoxide Dismutase-Contained Nanostructured Lipid Carriers on Second-degree Burn Wound Healing in Rat: an In-vivo Study

Introduction Superoxide dismutase enzyme (SOD) with high antioxidant activity and, by controlling oxidative stress and reducing the activity of free radicals like ROS, reduces injury and accelerates healing. NLCs were used as the main formulation due to their small particle size, better permeability, higher shelf-life and etc. The purpose of this study was to investigate the effect of nanostructured lipid carriers (NLC) on SOD activity in burn wound healing. Method: 27 rats were divided to 3 groups: target, positive and negative control. Formulations were examined for particle size, enzyme activity and loading. Each formulations were used for 21 days on rats and at the end of each week they were examined by macroscopic and microscopic Methods. Each group was given a score based on the histology characteristics. Results: Physicochemical properties showed that the particle size was between 35 and 85 nm, and the percentage of enzyme loading was 78% and the enzyme activity was 39.3% in the formulation of NLC+ENZ. Macroscopic examination showed that the best recovery rate was in the target group (NLC+ENZ) and showed better performance on the second and third weeks (pval=0.029 in day 14 and pval=0.000 in day 21). In pathological studies also shown that the angiogenesis and granulation tissue of the target group has a significantly better performance. In Granulation scores first week NLC+ENZ Pval = 0.003 In Granulation scores second week NLC+ENZ Pval = 0.001 In angiogenesis scores first week NLC+ENZ Pval = 0.000 Conclusion: This study showed that the formulation of the prepared nanoparticles had an acceptable enzymatic activity and loading percentages. The formulations of NLC+ENZ in comparison to the other two groups shows significantly improvement of pathologic factors, particularly angiogenesis, granulation tissue, and a faster reduction of inflammatory cells

3D Printing of Dental Prostheses: Current and Emerging Applications

Revolutionary fabrication technologies such as three-dimensional (3D) printing to develop dental structures are expected to replace traditional methods due to their ability to establish constructs with the required mechanical properties and detailed structures. Three-dimensional printing, as an additive manufacturing approach, has the potential to rapidly fabricate complex dental prostheses by employing a bottom-up strategy in a layer-by-layer fashion. This new technology allows dentists to extend their degree of freedom in selecting, creating, and performing the required treatments. Three-dimensional printing has been narrowly employed in the fabrication of various kinds of prostheses and implants. There is still an on-demand production procedure that offers a reasonable method with superior efficiency to engineer multifaceted dental constructs. This review article aims to cover the most recent applications of 3D printing techniques in the manufacturing of dental prosthetics. More specifically, after describing various 3D printing techniques and their advantages/disadvantages, the applications of 3D printing in dental prostheses are elaborated in various examples in the literature. Different 3D printing techniques have the capability to use different materials, including thermoplastic polymers, ceramics, and metals with distinctive suitability for dental applications, which are discussed in this article. The relevant limitations and challenges that currently limit the efficacy of 3D printing in this field are also reviewed. This review article has employed five major scientific databases, including Google Scholar, PubMed, ScienceDirect, Web of Science, and Scopus, with appropriate keywords to find the most relevant literature in the subject of dental prostheses 3D printing

The protective effect of Liza klunzingeri protein hydrolysate on carbon tetrachloride-induced oxidative stress and toxicity in male rats

Objective(s): Today, consumers are looking for food products providing health benefits in addition to meeting the basic nutritional needs of the body. This study aimed to evaluate the antioxidant and cytotoxic effects of Liza klunzingeri protein hydrolysate both in vivo and in vitro. Materials and Methods: Fish protein hydrolysate (FPH) was prepared using enzymatic hydrolysis with papain. In vitro antioxidant activity was assessed using five different antioxidant assays. The cytotoxic effect on 4T1 cell line was evaluated using the MTT assay. The distribution of the molecular weight of FPH was measured using HPLC. In the in vivo study, CCl4-exposed Wistar rats were orally treated with FPH (150, 300, and 600 mg/kg) or gallic acid (50 mg/kg) for 28 consecutive days. Results: Enzymatic hydrolysis gave hydrolysate rich in low molecular weight peptides (<1000 Da) with strong free radicals (ABTS, DPPH, and OH) scavenging activity and cytotoxicity. Treatment of CCl4-exposed rats with all doses of FPH significantly lowered serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). FPH at doses of 300 and 600 mg/kg significantly decreased lipid peroxidation and improved total antioxidant capacity in serum, liver, and kidney of the CCl4 exposed rats. All doses of L.klunzingeri protein hydrolysate reduced CCl4-induced nitric oxide production of the kidney. Liver histopathological damage caused by CCl4 also ameliorated with all doses of FPH. Conclusion: L. klunzingeri protein hydrolysate can be considered as a functional food to alleviate oxidative stress. Keywords Author Keywords:Antioxidant activity; Cytotoxicity; Liza klunzingeri; Oxidative stress; Protein hydrolysat

Clinical, epidemiological, and mycological features of patients with candidemia: Experience in two tertiary referral centers in Iran

Background and purpose: Candidemia is a major cause of morbidity and mortality among patients receiving immunosuppressive therapy and those hospitalized with serious underlying diseases. Here, we investigated the epidemiological, clinical, and mycological features of candidemia in Tehran, Iran. Materials and methods: A prospective observational study of all patients diagnosed with candidemia was performed at two referral teaching hospitals in Tehran, Iran, from February to December 2018. Demographic characteristics, underlying diseases, risk factors, clinical symptoms, and laboratory analyses of candidemic patients with positive culture were mined. Candida isolates were molecularly identified by sequencing of the internal transcribed spacer region (ITS1-5.8S-ITS2). The antifungal susceptibility testing for fluconazole, itraconazole, voriconazole, posaconazole, amphotericin B, caspofungin, micafungin, and anidulafungin against the isolates was performed using CLSI broth microdilution reference method (M27-A3). Results: A total of 89 episodes were identified, with an incidence of 2.1 episodes/1000 admissions. The common underling disease were malignancy (46%), renal failure/dialysis (44%), and hypertension (40%). The overall crude mortality was 47%. C. albicans (44%) was the most frequent causative agent, followed by C. glabrata (21%), C. parapsilosis complex (15%), C. tropicalis (11%), and C. lusitaniae (3.5%). All the isolates were susceptible to amphotericin B. The activity of all four azoles was low against non-albicans Candida species, especially C. tropicalis. Conclusion: The increase in non-albicans Candida species with reduced susceptibility to antifungal drugs might be alarming in high-risk patients. Therefore, accurate knowledge of predisposing factors and epidemiological patterns in candidemia are effective steps for managing and decreasing the mortality rate in candidemia.This study has been funded and supported by Tehran University of Medical Sciences, Tehran, Iran (Grant no. 99-2-99-48944).S