bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytotoxicity of the Ingredients of Commonly Used Toothpastes and Mouthwashes on Human Gingival Fibroblasts
Authors: Hasani Tabatabaei Masoumeh , Sadeghi Mahounak Farzaneh , Asgari Nafiseh , Moradi Zohreh
Published: June 2020

Objectives: Toothpastes and mouthwashes contain ingredients that may be toxic for oral mucosal tissues. This study aimed to assess the cytotoxicity of the ingredients of commonly used toothpastes and mouthwashes.
Materials and Methods: This experimental study was performed on 16 toothpastes and four mouthwashes widely available in the Iranian market. First, the concentration of six main ingredients of these products, namely sodium fluoride (NaF), sodium lauryl sulfate, cocamidopropyl betaine, zinc lactate, paraben, and sodium benzoate, was determined. The methyl thiazolyl tetrazolium (MTT) assay was used to assess the cytotoxicity of these materials for human gingival fibroblasts (HGFs). The MTT assay was performed at 1, 15, and 30 minutes following exposure to five concentrations of each material in triplicate (according to the concentrations obtained in the isolation step). Data were analyzed using three-way analysis of variance (ANOVA).
Results: The difference in the cytotoxicity of the materials was statistically significant (P<0.001). Cytotoxicity was time- and concentration-dependent; by an increase in the concentration of the materials, their cytotoxicity increased over time. The cytotoxicity of sodium lauryl sulfate and cocamidopropyl betaine was >90%. The cytotoxicity of NaF varied from 25% to 70%, and the cytotoxicity of all concentrations of zinc lactate and sodium benzoate was <50% for HGFs.
Conclusion: To decrease the cytotoxic effects of toothpastes, sodium lauryl sulfate and cocamidopropyl betaine should be replaced with safer detergents, and the concentration of fluoride should be decreased to 400 parts per million (ppm). Alternatively, fluoride may be replaced with other antibacterial and cariostatic agents.
Effect of Three Wavelengths of Diode Laser on the Efficacy of Bleaching of Stained Teeth
Authors: Saeedi Reza , Ranjbar Omrani Ladan , Abbasi Mahdi , Chiniforush Nasim , Kargar Mojgan
Published: June 2020

Objectives: Light irradiation and heat have been used to accelerate the process of tooth bleaching. This study aimed to assess the efficacy of conventional bleaching compared to laser-bleaching using three different wavelengths of diode lasers.
Materials and Methods: In this in-vitro experimental study, 40 extracted human central incisors were immersed in a coloring solution made of tea, coffee, and cola for 21 days. The L*, a*, and b* color parameters were measured before and after the immersion using spectrophotometry. The teeth were then randomly divided into four groups (n=10) as follows: group 1: 810-nm diode laser + Biolase Laser White 20, group 2: 940-nm diode laser + Biolase Laser White 20, group 3: 980-nm diode laser + Biolase Laser White 20, and group 4: conventional bleaching with Opalescence Boost without laser irradiation. One-way analysis of variance (ANOVA) was used to assess the effect of laser type and bleaching technique on color parameters.
Results: The 940-nm (∆E=28.5896) and 810-nm laser groups (∆E=21.2382) showed the highest and the lowest bleaching efficacy, respectively; however, the groups were not significantly different in terms of bleaching efficacy (P>0.05).
Conclusion: Laser-bleaching with 810-, 940- and 980-nm wavelengths of diode laser has an efficacy similar to that of conventional bleaching but in a shorter period. No difference was noted between different laser wavelengths in terms of bleaching efficacy.
Relationship Between Parafunctional Habits and Salivary Biomarkers
Authors: Khayamzadeh Mina , Mirzaii-Dizgah Iraj , Aghababainejad Pegah , Habibzadeh Sareh , Kharazifard Mohammad Javad
Published: June 2020

Objectives: Parafunctional habits, as one of the etiological factors of temporomandibular disorders (TMD), are an individual’s response to increased stress. During stress and depression, biomarkers such as cortisol and salivary alpha-amylase (SAA) are secreted in the saliva. The present study aimed to investigate whether there is a correlation between salivary stress biomarkers and parafunctional habits.
Materials and Methods: Thirty-two cases, from May to September 2015, were selected based on two standard stress questionnaires, namely the depression anxiety stress Scale-21 (DASS-21) and the Beck Anxiety Inventory (BAI). Saliva samples were collected to examine the level of unstimulated salivary cortisol and SAA. The significance of the results was assessed via student’s t-test and Mann-Whitney test (α=0.05).
Results: The mean concentrations of cortisol and SAA in unstimulated saliva were significantly higher in the case group than in the control group (P=0.01 and 0.44, respectively). The mean scores of anxiety, stress, and depression were significantly higher in the case group than in the control group (P<0.05).
Conclusion: It seems that the levels of salivary cortisol and SAA, as well as stress, anxiety, and depression scores, are higher in patients with parafunctional habits.
Mandibular Setback as an Adjunctive Strategy for Reconstruction after Tumor Resection: A Technical Note and Case Report
Authors: Mirmohammadsadeghi Hassan , Aghdashi Farzad , Nahvi Golnaz , Esmaeelinejad Mohammad
Published: June 2020

Mandibular defects due to surgical resection of pathologies are common challenges for maxillofacial surgeons. In some clinical situations, alteration or combination of different surgical procedures is needed to reduce the size of bony defects and improve the success rate of bone grafts. In the current study, an 18-year-old female with a pathological lesion (ameloblastoma) in the mandible is presented. After tumor resection, bony defect reconstruction with autogenous bone graft was combined with a mandibular setback to facilitate the procedure. In this case, the simultaneous combination of orthognathic mandibular setback movement with tumor resection in a single surgical session helped to reduce the bony defect size. The adoption of this approach led to a decrease in the volume of graft harvesting and improved the success rate of the grafting procedure.
Increased miR-223-3p in Leukocytes Positively Correlated with IL-17A in Plasma of Asthmatic Patients
Authors: Xu Wenjuan , Wang Yimin , Wang Chen , Ma Ying , He Shaojun , Kang Yanmeng , Yang Jiong
Published: June 2020

Asthma is a common airway inflammation with an intricate underlying mechanism. The role played by circulating miRNAs in asthma remains unclear. In the present study, we aimed to investigate the role of miR-223-3p in leukocytes of asthma and identify the relationship between miR-223-3p and inflammatory cytokines in asthma. Using real-time polymerase chain reaction (RT-PCR), we detected miR-223-3p expression in peripheral blood leukocytes from 23 asthmatic patients and 20 healthy controls. The levels of IFN-γ (Th1 cytokine), IL-4 (Th2 cytokine), IL-17A (Th17 cytokine) in plasma were examined using enzyme-linked immunosorbent assay (ELISA). Analysis of variance (ANOVA) and Spearman’s test was used for statistical analysis. The expression of miR-223-3p in peripheral blood leukocytes was upregulated in the asthmatic patients compared with that in the healthy controls. Increased miR-223-3p expression was associated with forced expiratory volume in 1-second percent predicted (FEV1% predicted). A positive correlation was noted between miR-223-3p and IL-17A. The findings of this study showed that miR-223-3p plays a vital role in the pathogenesis of asthma and can serve as a novel biomarker for asthma.
A Randomized, Triple-blind Placebo-controlled Trial to Determine the Effect of Saffron on the Serum Levels of MMP-9 and TIMP-1 in Patients with Multiple Sclerosis
Authors: Ghasemi Sakha Fatemeh , Azimi Saeen Amirreza , Moazzeni Seyed Mohammad , Etesam Farnaz , Vaezi Gholamhassan
Published: June 2020

Matrix metalloproteinases-(MMP)-9 facilitates the migration of T-cells to central nervous system (CNS), while (Tissue inhibitor of metalloproteinases-1) TIMP-1 inhibits the function of MMP-9. This study aimed to determine the appropriate treatment option for multiple sclerosis (MS). Forty-three relapsing-remitting MS (RRMS) patients were randomly divided into two groups of 22 (group A, placebo) and 21 (group B, Saffron pill) individuals. Serum samples were collected from patients’ blood before using the Saffron pills/placebo pills and then after 12 months. The serum level of MMP-9 and its inhibitor, as well as TIMP-1, were measured by ELISA kits. Data were analysed using SPSS version 13. MMP-9 serum levels noticeably decreased in patients with MS following 12 months of treatment with Saffron pills (p=0.006) while the changes were not significant before and after 12 months of treatment with placebo pills. Although the levels of TIMP-1 increased significantly after one year treating with Saffron pills (p=0.0002), a considerable difference was not observed before and after taking the placebo pills. The study finding revealed that 12-months treatment with Saffron could have a significant role in reducing the serum level of MMP-9 and increasing the serum level of TIMP-1 in RRMS patients. Therefore, modulating the serum levels of MMP-9 as an important regulator of T cell trafficking to the CNS might be a promising strategy in the treatment of MS patients.
Examining the Amount of Unnecessary Knee MRI Prescription in the MRI Center of Bushehr University of Medical Sciences in 2018
Authors: Salari Hedayat , Omranikhoo Habib , Amini Azam , Amiri Mosayeb , Bayyenat Saeed , Azmal Mohammad , Esfandiari Atefeh
Published: June 2020

Background: Many prevalent disorders were observed in and around the knee joint. Magnetic resonance imaging (MRI) was a modern and costly diagnostic technology that was progressively applied worldwide. This study was conducted in the Bushehr educational hospitals in 2018 with the purpose of determining the necessity of knee MRI prescriptions.
Methods: This paper was a kind of cross-sectional descriptive-analytical study. The statistical population of the study was all patients who were prescribed knee MRI due to the appearance of knee problems and referred to the MRI Center of Bushehr University of Medical Sciences in 2018. The sampling method was convenient sampling. The sample in this study included 274 patients. The indications and data collection form of Vojdani et al.'s study were used to specify the necessity of the mentioned prescriptions. In this study, SPSS 22 software was applied to analyze data. Also, the Chi-Square test was used to for analyzing the data.
Results: Among the total studied population in this study, MRI prescription was evaluated inappropriately for approximately 24 % of patients. In this study, the appropriateness of the prescriptions had a significant relationship with age, job, education level, physician prescribing, and requesting MRI (P-value < 0.05).
Conclusion: It could be deduced that about a quarter of MRI was not appropriate to clinical prescription. Regarding the high cost of hospital and the necessity of their reduction, induced demand would be prevented by using valid indications. Therefore, reducing unnecessary prescriptions yielded to fewer costs of the health system and patients.
Challenges of Payment Methods in the Iranian Health System and Solutions: A Qualitative Study
Authors: Barouni Mohsen , Ahmadian Leila , Saberi Anari Hossein , Mohsenbeigi Elham
Published: June 2020

Background: The implementation of different reimbursement methods has various positive and negative effects on the health system of different countries. Identifying the challenges of these methods is essential to improve these reimbursement methods and modify them if required. This article aimed to qualitatively assess the challenges of current hospitals' payment systems in the Iranian health system and determine the required solutions for modifying these payment systems.
Methods: This qualitative study was conducted in 2019. Semi-structured interviews were conducted recruiting 20 experts including operational, middle and top managers working in three different levels of health systems. Data collection was continued until it reached a saturation point. MAXQDA 10 was used for data analysis. The data content analysis method was used to analyze the data and the themes and categories were determined.
Results: The challenges of the payment systems were categorized into four main themes regarding policy, cost, regulatory and functional challenges, and 15 sub-themes. The findings related to the proposed strategies were presented in six main themes consisting of legal solutions, structural reform, cost, quality improvement, service provider and client, and monitoring and evaluation; and 12 sub-themes.
Conclusion: This study showed that the health systems in Iran face various structural and procedural challenges in terms of reimbursement mechanisms. Therefore, it is recommended that policymakers pay attention to these challenges before making any changes. Using hybrid payment systems can be one of the proper solutions.
Identifying Influential Factors of the Patient Discharge Process from ShafaTakestan Hospital in Qazvin City
Authors: Rahmani Parisa , Mohebbifar Rafat , Rafiei Sima
Published: June 2020

Background:The process of the patient discharge from the hospital is one of the most important processes that has been taken into consideration by managers in recent years. An efficient health system can only accomplish its duty to provide the health of the community by providing the right services and this system can be evaluated through its services. Therefore, the necessity of performing this research is to improve the quality of hospital services for patients and increasing patient satisfaction. This study has been aimed to identify the factors affecting the process of patient discharge.
Methods: This was a cross-sectional study conducted in a general hospital located in Takestan, Qazvin in 2019. The study population in the qualitative section of the study included those who were aware of the discharge process and had managerial positions in the hospital. The sampling process was continued until achieving data saturation. The required information was gathered through reviewing relevant literature, observing the discharge process, and conducting semi-structured interviews with managerial members and study experts.
Results: In the present study, the most important factors affecting the discharge process were lack of timely physician visit and issuance of the discharge order, delay in the approval of medication used by pharmacy officer, sending discharge files to hospital discharge unit, the patients' needs, diagnostic services (discharging with doctor's opinion), delays in registering nursing records, and undue secretarial performance in reviewing and recording reports in the hospital information system.
Conclusion: The results of the present study, in line with other researches, have shown that the importance of the discharge process on hospital performance is undeniable and this process needs continuous investigation, monitoring, and intervention.
Are Price, Income, and Education Expenditure Important in the Iranian households' Demand of Healthcare Services: 2011 to 2017?
Authors: Ahadinezhad Bahman , Khosravizadeh Omid , Baghian Najmeh , Mohtashamzadeh Bahareh , Shahsavari Saeed
Published: June 2020

Background: In health economics, policymakers need to be aware of the individuals' sensitivity and reaction to change effective factors on the healthcare services demand. This study aimed to estimate the healthcare demand function and extract the price, income, and educational elasticity in Iran.
Methods: A panel of macro data was used to estimate the demand function. The data included provincial average of the nominal values of Iranian household healthcare and education expenditure, provincial average of their nominal income, and Consumer Price Index values of the healthcare services from 31 provinces during 7 years (2011 to 2017). This information was obtained from the annual Household Budget Survey Reports and no sampling was performed in this research. The dependent variable was the actual amount of demand for health care services. Robust pre-estimation tests and a robust standard error panel regression were run to estimate the demand function in Stata 15.
Results: All variables were stationary at the first-order differential (P-value < 0.01). All four variables were co-integrated (P-value < 0.01). The cross-sectional and fixed effects existed for each province (P-value < 0.01). Income and educational expenditure had a positive association with healthcare demand. Price elasticity of demand was -0.897 (P-value < 0.01), income elasticity was 0.491 (P-value < 0.1), and elasticity of education expenditure was 0.486 (P-value < 0.01). Noteworthy, 1 % increase was observed in the household incomes and their educational expenditure increased the demand for health care services by about 0.49 % and 0.48 %, respectively.
Conclusion: Healthcare services have been low elastic to price and education expenditure and have also been the essential commodity in the household budget in Iranian households. Later, the price and income coefficients were consistent with the health investment model, but coefficient of the education expenditure was not matched with predictions of the health investment model.
Technology and its Solutions in the Era of COVID-19 Crisis: A Review of Literature
Authors: Mastaneh Zahra , Mouseli Ali
Published: June 2020

Background: An important feature of novel coronavirus disease 2019 (COVID-19) is its rapid human to human transfer.Technologies can play an important role in controlling this disease. Therefore, this study aims to investigate the technologies that have been applied to solve the COVID-19 crisis. Besides, the approaches used by these technologies are surveyed.
Methods: In this narrative review, international databases were searched for papers investigating the role of various technologies in the management of COVID-19 from December 2019 to 20 April 2020. The keywords searchedwere “Technology”, “COVID-19”, “nCOV-19”, Diagnostic Technologies”, “Therapeutic technologies”, “Telemedicine”, “Internet of Things”, “Big data”, “Blockchain”, “Robots”, and “Drones”. Forty-seven articles were found to meet the inclusion criteria after the title, abstract, and full text were reviewed.
Results: Two major categories of technology were found to be applied to combat COVID-19. The first category involves technologies that have the potential to support the diagnostic process and case-finding including non-contact thermometers, artificial intelligence, drones, self-assessment applications, and virus genome sequencing. The second category includes technologies with therapeutic and logistic applications searching for medicines or vaccines, and provide support services such as pharmaceutical tech, robots, telemedicine, Geographic Information System (GIS), Internet of Things, and big data and blockchain.
Conclusion: It can be concluded that technologies with the ability to reduce human contacts through teleservices as well as those that quickly enable decision-making via in-depth analysis received more attention among the health authorities and organizations.
MTHFR C677T and TS 5’-UTR 3R/3R Gene Polymorphism in Methotrexate-Resistant Childhood Acute Lymphoblastic Leukemia
Authors: Ugrasena I Dewa Gede , Notopuro Harianto , Sudarmo Subijanto Marto , Sudiana Ketut , Gatot Djajadiman , Idjradinata Ponpon
Published: June 2020

BACKGROUND: Childhood acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy in Indonesia and often treated by methotrexate (MTX). Though it can be cured in 30-60% of patients, MTX resistance remains the major cause of treatment failure in childhood ALL. Previous sudies showed that its anti-leukemic property was moderated by MTX ability to inhibitmethylene tetra hydrofolate reductase (MTHFR) and thymidylate synthase (TS) in folate metabolism. This study investigates the correlation between MTHFR and TS polymorphism and MTX resistance in ALL children.METHODS: A total of 155 subjects obtained from all subjects prior to chemotherapy. DNA from blood samples were extracted and underwent polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) to evaluate MTHFR C677T and TS 5’-UTR 3R/3R polymorphism.RESULTS: There was significant correlation between MTHFR C677T and TS 5’-UTR 3R/3R gene polymorphism with MTX resistance. Subjectswith MTHFR C677T and TS 5’-UTR 3R/3R gene polymorphism were 4 times (p=0.007) and 6.4 times (p=0.001) more likely to be MTX resistant than those without gene polymorphisms, respectively.CONCLUSION: MTHFR C677T andTS 5’-UTR 3R/3R represent dominant gene polymorphism related to MTX resistance in childhood ALL.KEYWORDS: gene polymorphism, folate metabolism, acute lymphoblastic leukemia
Dedifferentiation of MCF-7 Breast Cancer Continuous Cell Line, Development of Breast Cancer Stem Cells (BCSCs) Enriched Culture and Biomarker Analysis
Authors: Prayogo Ami Ashariati , Wijaya Andi Yasmin , Hendrata Winona May , Looi Steven Sheng , I’tishom Reny , Hakim Lukman , Rantam Fedik Abdul , Sudiana I Ketut , Abdurachman Abdurachman
Published: June 2020

BACKGROUND: Cancer stem cells (CSCs) eradication might serve as a robust approach for cancer eradication. MCF-7 as breast cancer continuous cell line is known to contain breast CSCs (BCSCs) for its capability to maintain its original tumor population. CSCs enriched culture is a fundamental tool for CSCs targeted therapy development. Effective and unsophisticated CSCs dedifferentiation protocol for producing CSCs enriched culture is needed.METHODS: MCF-7 cells were cultured initially in Dulbecco's Modified Eagle Medium (DMEM) low glucose medium then changed to DMEM:F12. Serum starvation was performed during each medium refreshment gradually with fetal bovine serum (FBS) concentration of 10%, 5%, 2.5% until reaching 1% FBS concentration. Stable MCF-7 culture was then adapted to serum free culture system, containing DMEM:F12, epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and B27 supplement as dedifferentiation protocol for 18 days. Cluster of differentiation (CD)44 and CD24 double staining immunocytochemistry was performed to evaluate cell stemness.RESULTS: The population of cells expressing BCSCs markers (CD44+/CD24low) in non-adherent single cells subpopulation was significantly increased after the dedifferentiation procedure (70.39%) compared to control groups (0.71%) (p<0.05). In contrast, the expression of BCSCs marker in adherent single cells subpopulation and for both adherent and non-adherent mammosphere the BCSCs markers showed a stable expression.CONCLUSION: BCSCs enrichment of breast cancer cell cultures from MCF-7 breast cancer cell line can be performed. Breast cancer cell plasticity is observed during the dedifferentiation protocol. Development of dedifferentiation inducing protocols can serve as an important foundation for breast cancer therapy development through BCSCs elimination.KEYWORDS: breast neoplasms, cell line, dedifferentiation, immunohistochemistry, neoplastic stem cells
La construcción del divorcio en Colombia desde las normas jurídicas a partir del siglo XIX
Authors: Ruiz Manotas Paola
Published: June 2020

En este trabajo describiremos cómo se ha regulado el divorcio en Colom­bia, desde la época de la Colonia hasta la promulgación de la Constitución de 1991 y la Ley 25 de 1992, destacando factores políticos y religiosos que influyeron de manera directa en dichas normas y determinando de qué manera esta institución ha contribuido al posicionamiento social de la mujer.
Interés general e interpretación contractual en Cuba
Authors: Vázquez Pérez Arsul José , Galbán Rodríguez Liuba
Published: June 2020

Este artículo aborda los problemas que afectan la definición de la noción de interés general y su interrelación con la libertad individual y otros valores. Los autores apuestan por el rescate de la noción de bien común para dotar de una fisono­mía coherente la idea de interés general que más se aviene con el criterio de justicia equitativa. Finalmente, valora las implicaciones del reconocimiento en Cuba del in­terés general como criterio axiológico aplicable a la interpretación de los contratos y traza algunas pautas para su mejor aplicación al proceso de inteligencia contractual.
Methodology for Assessing the Influence of Cultural Infrastructure on Regional Development in Poland and Ukraine
Authors: Revko Alona , Butko Mykola , Popelo Olha
Published: June 2020

The aim of the article is to characterize the level of the region’s diversification according to the cultural component of social infrastructure based on grouped statistical indicators. This paper uses Perkal’s synthetic ratio method to characterize the level of cultural infrastructure development in Ukrainian and Polish regions. The analysis, conducted between 2010 and 2017, concerned cultural organizations such as libraries, theaters, concert organizations, museums, cinemas, art and sports schools, and was based on regional data of Polish and Ukrainian public statistics. It was found that the primary barriers to access to cultural infrastructure are inadequate funding, disability, geographic remoteness, disparities in education, and material living conditions. The determinants of modernizing cultural infrastructure in the region are defined.
Trends in Tobacco Consumption – a Comparative Analysis of WHO European Region Countries
Authors: Suchecki Adam Mateusz
Published: June 2020

Tobacco consumption, as well as the consumption of any other psychoactive substances, lead to addictions, which is a serious problem that modern societies have to face. To reduce the negative consequences of nicotine consumption and to provide sustainable development, many governments, in both developed as well as developing countries, adopt policies to reduce tobacco production and consumption. For example, they implement various health programs to combat addiction, and they also provide appropriate financial and fiscal resolutions. Any actions taken at different decision-making levels are often bounded with economic and financial policies of a particular state, including fiscal policy. State interventionism concerning tobacco is most visible in developed countries such as the US, Canada, and European Union countries. Developing countries and Asian countries have also started to introduce regulations concerning tobacco consumption on a large scale in response to the negative effects of nicotinism. The main aim of the paper is to show consumption trends as well as the fiscal and price policies of tobacco products. The theoretical part is supplemented by data from reports and analyses presented by the World Health Organization (WHO).
ВОЛЬТАМПЕРОМЕТРИЧЕСКОЕ ОПРЕДЕЛЕНИЕ ПЕРОКСИДА ВОДОРОДА C ПОМОЩЬЮ СЕНСОРОВ НА ОСНОВЕ НАНОЧАСТИЦ СЕРЕБРА В ОБЪЕКТАХ ТЕХНОГЕННОГО И ГЕОЛОГИЧЕСКОГО ПРОИСХОЖДЕНИЯ
Authors: Перевезенцева Дарья Олеговна , Горчаков Эдуард Владимирович
Published: June 2020

Актуальность работы связана с необходимостью определения низких содержаний пероксида водорода в объектах техногенного и геологического происхождения. Цель: разработать сенсор с повышенной чувствительностью на основе наночастиц серебра для контроля окружающей среды и определить концентрацию пероксида водорода в водных объектах. Объекты: артезианская и дождевая вода, собранная в черте города и пригорода. Методы: просвечивающая электронная микроскопия, вольтамперометрия. Результаты. Форма и размер наночастиц серебра зависят от природы восстановителя. При использовании двух восстановителей боргидрида и цитрата натрия получают частицы сферической формы наименьшего размера – от 0,5 до 17,5 нм. При использовании цитрата натрия получают наночастицы серебра большего диаметра – от 10 до 55 нм, различной формы: сферические, призматические и треугольные. Наночастицы серебра, полученные с использованием боргидрида натрия, агломерированы в цепочки размером до 65 нм. Особенностью электровосстановления нанофаз серебра, полученных в присутствии цитрата натрия, на поверхности графитового электрода в 0,1 М NaOH является восстановление ионов серебра из комплексных соединений [Ag(OH)2]–. Предложен механизм электрохимических процессов перехода нанофаз серебра, полученных с использованием различных восстановителей. Этот механизм не зависит от природы восстановителя. Установлено, что катодный максимум при Ек=0,08 В соответствует процессу восстановления пероксида водорода. Зависимость катодного максимума от концентрации пероксида водорода, полученного с использованием сенсора на основе наночастиц серебра в присутствии цитрата натрия, была линейной в диапазоне от 0,1 до 1 нМ, предел обнаружения составил 0,087 нМ. Определена концентрация пероксида водорода в дождевой и артезианской воде. Предложен простой чувствительный сенсор на основе наночастиц серебра, полученный с использованием восстановителя цитрата натрия. Этот сенсор имеет широкий диапазон концентраций для определения пероксида водорода.
ОСОБЕННОСТИ ОПТИМИЗАЦИОННОЙ ЗАДАЧИ НА ПОДБОР МАТЕРИАЛОВ ДЛЯ МИНИМИЗАЦИИ ПОТЕРИ ТЕПЛА ЧЕРЕЗ ПЛОСКУЮ СТЕНКУ
Authors: Сабденов Каныш Оракбаевич , Ерзада Майра
Published: June 2020

Актуальность. Хранение тепла и его эффективное использование связано с подбором материалов для тепловой изоляции стенок. Такие материалы представлены широким спектром теплофизических свойств и стоимости на рынке. Тогда возникает задача оптимизации, ее решение должно обеспечивать наименьшие потери тепла через стенку при ограниченном выборе материалов с заданными коэффициентами теплопроводности. Вместе с тем при решении оптимизационной задачи могут возникнуть сложности в оценке правильности полученных результатов. Поэтому этот вопрос нуждается в детальном обсуждении. Цель: математическое моделирование стационарных режимов переноса тепла, формулировка минимаксной задачи о потере тепла через стенку, построение области решения минимаксной задачи, анализ полученных результатов и формулировка выводов. Объект: стенка, теплоизоляционные материалы, потоки тепла, условия минимальности, оптимальные решения. Методы: решение минимаксной задачи с применением аналитических методов. Результаты. Сформулирована простая минимаксная задача: дана двухслойная плоская стенка с произвольными коэффициентами теплопроводности и фиксированными толщинами. На правой и левой границах стенки задана постоянная и различная температура. Также задан максимальный тепловой поток через стенку и область возможных значений коэффициентов теплопроводности (т. е. возможные материалы) для каждого слоя стенки. Требуется из этой области найти коэффициенты теплопроводности, обеспечивающие тепловой поток ниже заданного максимального значения. На этом примере показано, что решение поставленной минимаксной задачи может приводить к неверному результату: можно получить или не весь спектр допустимых решений, или задача может не иметь решения. Это означает необходимость строгого отношения к формулировке и методу решения оптимизационных задач для процессов переноса тепла.
ПЕРСПЕКТИВЫ ДЕЦЕНТРАЛИЗОВАННЫХ СИСТЕМ ЭЛЕКТРОСНАБЖЕНИЯ ПОСТОЯННОГО ТОКА С РАСПРЕДЕЛЁННОЙ СОЛНЕЧНОЙ ГЕНЕРАЦИЕЙ
Authors: Лукутин Борис Владимирович , Муравьев Дмитрий Игоревич
Published: June 2020

Актуальность исследования обусловлена необходимостью расширения вариантов автономных систем электроснабжения, в частности, фотоэлектрических, в рамках постановления правительства, связанного с ратификацией Россией Парижского соглашения по климату от 23.09.19. Системы электроснабжения постоянного тока с участием возобновляемых энергоисточников для децентрализованных потребителей могут стать предпочтительной альтернативой переменному токуприусловиисоответствия большинству обязательств Парижского соглашения по климату, а также требованиямповышения энергетической безопасности. Цель: повышение качества электрической энергии в распределительных сетях 0,4 кВ, декарбонизация окружающей среды от углеводородных энергоносителей, повышение энергетической безопасности автономной системы электроснабжения путём увеличения вкладав энергетический баланс возобновляемого энергоресурса, а также снижение стоимости вырабатываемойэлектрической энергии путём перехода с переменного на постоянный ток. Методы. Ввиду сложности натурного исследования электроэнергетических систем с генерацией различной физической природы в качестве инструментов исследования были определенны: математическоемоделирование споследующей компьютерной реализацией в программныхкомплексах высокого уровня.Наиболее полно условиям моделирования отвечает MatLab, в частности, его приложение блочного моделированияSimulink и библиотека блоков SimPowerSystems. Результаты. Разработан программный инструмент, позволяющий осуществлять имитационное моделирование режимов работы фото-дизельных систем электроснабжения, включая генерацию с учётом текущего электропотребления и инсоляции с целью определения рациональных технико-экономических параметров гибридных генерирующих систем; выявлены критерии целесообразности и эффективности построения фото-дизельных электрических систем на постоянном токе для электроснабжения удаленных потребителей.
Speaking self-efficacy beliefs of Turkish university students
Authors: Demirel Mehmet Volkan , Türkel Ali , Aydın İbrahim Seçkin
Published: June 2020

Expressing thoughts and feelings effectively is a vital skill for individualsâ€™ professional career. University students should thus attach due importance to their communication skills as they receive their professional training. Self-efficacy beliefs can be regarded as an influential element in speaking skills, and may affect different aspects of speaking performance. In this respect, the aim of this study was to examine the speaking self-efficacy beliefs of final-year university students based on different variables. The reason why this study focused on final-year students was to determine the level at which they perceived themselves in terms of speaking in the pre-service period. Accordingly, the "Speaking Self-Efficacy Scale" was administered to 843 final-year students (454 female, and 389 male) studying at a Turkish university, and the data gathered were analysed through statistical methods. The results showed that the students' speaking self-efficacy levels were considerably high based on their scores on the scale. There was no significant difference between the students' self-efficacy beliefs based on gender, but they were observed to differ in their speaking self-efficacy beliefs based on their faculties. The analysis regarding the variable of experience in prepared speeches also revealed a significant difference in the students' speaking self-efficacy beliefs. Moreover, the university students' speaking self-efficacy beliefs were found to differ based on their annual amount of reading. It can be argued that improving the current level is possible through participation in more prepared speech activities and gaining a reading habit.

Keywords: Self â€“ Efficacy beliefs, Speaking, Speaking skills.
Teacher candidates’ satisfaction with massive open online courses in Turkey
Authors: Vezne Rabia
Published: June 2020

Adult education, especially teacher education, is one of the most important issues in Turkey in order to increase the quality of education and to keep up with the countries which aim to become one of the most competitive and knowledge-based economy in the world. Therefore, most of the universities started to improve their distance learning provisions by using massive open online courses (MOOCs). The purpose of this study is to understand teacher candidates’ opinions on MOOCs and their satisfaction with MOOCs. A mixed method including qualitative and quantitative approaches was used in this study. Results show that the MOOCs have a positive effect on teacher candidates’ personal development and learning life; therefore, they are satisfied with the MOOCs. Only the satisfaction level in learner–instructor interaction is lower in asynchronous courses. As adult learners, they wanted to be more active in MOOCs. These findings improve the understanding of MOOC’s learning satisfaction and contribute to design and develop better MOOCs according to learners’ needs and demands.
Keywords: adult education, teacher education, distance education
The effect of self- questioning strategy in developing independent thinking in teaching physics
Authors: Al-Swelmyeen Monther Bsharh , Sakarneh Mohammad Abed , Al zabenc Ghadeer Pernec
Published: June 2020

This study aimed at determining the effectiveness of self- questioning strategy in developing independent thinking in teaching physics. The researcher used the Independent Thinking Test on a purposive sample consisted of (46) students from the first secondary scientific class in Amman schools in Jordan. A quasi-experimental approach was adopted. To analyze the data a statistical Package for the Social Sciences (SPSS) was used. The study showed a statistically significant difference between the means of the two groups (experiment and control group) in the independent thinking level and it was in favor of the experimental group. The study recommended preparing and developing teaching programs according to the self-questioning strategy and conducting similar studies on new samples at different age levels and new variables.

Keywords: Self-Questioning, independent Thinking, Physics.
Investigation of relationship between subjective well-being levels and academic achievements of university students according to various variables
Authors: Gokalp Murat
Published: June 2020

In this study, it is aimed to determine and evaluate the relationship between the subjective well-being levels of the university students and their academic achievement according to various variables. The study group consisted of 600 students from various faculties of Samsun 19 Mayıs University. Subjective Well-being Scale developed by Tuzgöl-Dost (2004) and academic achievement scores prepared by the researcher were used as data collection tools. The subjective well-being scale, which consists of 46 items, aims to measure the subjective well-being of individuals. Students' academic achievement scores were obtained with personal information form. In the study, simple regression analysis was performed to examine the predictive power of subjective well-being on academic achievement. According to the results of the regression analysis, subjective well-being significantly predicted positively (β = .330, t = 54.704, p <.01) and 5% of the variance in subjective wellbeing scores. According to these results, as the subjective well-being of the participants increased, their academic achievement levels increased. The level of subjective well-being of the students differed according to the number of faculty and the number of siblings they studied. These findings were discussed in the light of the literature and suggestions for practitioners and researchers were presented. Keywords: Faculty, level of well-being, subjective well-being, university students
A comparative analysis of the 4th and 5th grade social studies curriculum according to revised bloom taxonomy
Authors: Koc E. Seda , Ontas Turgay
Published: June 2020

This study, in which the distribution of the attainments of Turkey, Singapore, Hong Kong and Canada (Ontario) Social Studies Curricula was aimed to be analyzed according to the revised Bloom's taxonomy, was designed with qualitative research. Document analysis technique, that is one of the qualitative research data collection techniques, was used in the research. The data source of the research consisted of the social studies curricula of the mentioned countries and the frequency and percentage calculation was used to show the taxonomic distributions of attainments. According to the findings obtained in the study, it was determined that the majority of the attainments in all of the social studies curricula examined in the study were commonly at the conceptual knowledge dimension and understand cognitive process. It was also found out that the social studies curriculum of Canada and Singapore were the curricula with the highest level of objectives for the higher levels.
Keywords: Social Studies, Curriculum, Attainment, Revised Bloom Taxonomy
EVALUATION OF ARABIC LANGUAGE TEXTBOOKS AT UIN SYARIF HIDAYATULLAH JAKARTA
Authors: Royani Ahmad , Nawawi Mukhson , Maswani Maswani
Published: June 2020

This research was conducted with the aim of describing the level of compatibility of Arabic language textbooks at UIN Syarif Hidayatullah Jakarta with the general purpose of learning Arabic. This research is a descriptive  and non-interactive study. The research method used is the content analysis, because in this study the contents of the textbooks in Arabic was analyzed The results of the study show that in general the books evaluated have been good and decent enough to be used as book dars, except that there needs to be an adjustment in terms of material content. In terms of the completeness, breadth and depth of the material, it appears that the book al-arabiyyah bi annamadziz, al-arabiyyah li tullabil jamiah, and the Arabic language of the Quran, make Arabic material complete, detailed, and profound which is gradually adjusted to the level of marhalah. In terms of material accuracy, these books contain grammatical and accurate terms In terms of the latest material, the book a al-arabiyyah bi annamadziz is considered not up-to-date.
DEVELOPMENT OF THE BOOK "MUTAMMIMAH AJURUMIYAH" BASED ON STRUCTURAL THEORY TO IMPROVE GRAMMATICAL COMPETENCE / تطوير كتاب "متممة الآجرومية" على أساس نظرية بنيوية لترقية الكفاءة النحوية
Authors: Mustofa Nurul Hana
Published: June 2020

Grammar is important in student's behavior when learning the language. Education must be nice and right. Education in the institutes continues in traditional methods, the method used to read and translate, as well as the educational book does not have the objectives of education, teaching methods and testing. The researcher should therefore design the textbook in grammar mainly to the agro-complementary book. So researcher develope book in light of the structural theory to make students active in learning. This research aims to: (1) the development of the agro-complementary book in the light of structural theory, (2) knowledge of the effectiveness of the developed book. After the researcher researched, the results of the research appeared: (1) the developed book was designed and called the researcher by the rules and applied."" The book was printed to teach grammar in the classroom. (2) The result of both experts, students and a grammar teacher indicates that this developed book is decent and valid for its use in education, as well as the test result between the group and the experience has a difference
QURANIC EXEGESIS AS SOCIAL CRITICISM: The Case of Tafsîr al-Azhâr
Authors: Daud Ilyas
Published: June 2020

This paper examines one of Nusantara commentary books entitled Tafsîr al-Azhâr that is written by Hamka. By analyzing the contents of the commentary and tracing the historical roots of the birth of the work, this study shows that Hamka contextualises his interpretation as a criticism against the Sukarno regime. Among the critiques that he poses in his commentary suggest that Sukarno aligns to Communism and the political policies of his administration resonate to the interest of Communist while at the same time are detrimental to that of Muslims. From the historical perspective, there was, in fact, a conflict between Hamka and Sukarno concerning the issue of Communism. In other words, there is a close relationship between Sukarno’s affinity to Communism and Muslim’s conflict with Communists in Indonesia. In the development of tafsîr studies so far, tracing the interpretation material in the context of social criticism is considerably understatement. This is the reason why this study takes this approach. This study suggests that tafsîr (Quranic exegesis) is not just a task of understanding the divine message, but can also be a social critic.
TAFSÎR ON JIHAD VERSES IN AKU MELAWAN TERORIS: Relevance Measurement in The Perspective of Fakhr Dîn al-Râzî
Authors: Hamdan Ali
Published: June 2020

A discourse on justification of radical act faked as jihad based on Fakhr al-Dîn al-Râzî’s perspective is the cause of this study. The question is “How is al-Râzî’s opinion on verses used to justify radical acts which are faked as jihad?” This study uses the perspective of Fakhr al-Dîn al-Râzî’s Tafsîr bi al-Ra’yi. This is a library research employing qualitative explorative paradigm. All data are in the form of documentation; primary data are from Mafâtîḥ al-Ghayb and book entitled Aku Melawan Teroris as well as other secondary data. The study shows, first: jihad and its meaning are relevant with the period of Quran revelation to date and theologically they will also be relevant in the future; nothing changes from jihad’s concept and substance except the situation and condition. Second, there are five verses in Quran becoming the justification basis of radical acts in the name of jihad i.e. Q.S. al-Tawbah [9]: 5, Q.S. al-Tawbah [9]: 14, QS al-Tawbah [9]: 36, Q.S. Anfâl [8]: 39, and  Q.S. al-Baqarah [2]: 191; yet it is contra productive for al-Râzî. Through this study, al-Râzî’s tafsîr model is expected to be a formula and new opinion to deeply comprehend, contextual wise, the meaning of those verses.
The impact of digital transformation and industry 4.0 on the aspects of value: Evidence from a meta-synthesis
Authors: Cruzara Giovani , Takahashi Adriana Roseli Wunsch , Sandri Emanuel Campigotto , Cherobim Ana Paula Mussi Szabo
Published: June 2020

We use a meta-synthesis approach to review qualitative case studies where the relationship between value and digital transformation/industry 4.0 is explored. Our goal is to provide contributions beyond those achived on the original studies, thus providing novel insights from the study findings. The results demonstrate that value is explored on two dimensions:  Business Models and value chains. However, we identify that studies tend to overlook critical points of industry 4.0 when exploring value. This meta-synthesis demonstrate that studies need to encompass a broader scenario, dealing also with co-creation of value and also considering ecosystem aspects where the organizations are inserted for the comprehension of value capture aspects. We conclude by providing future research directions based on the meta-analysis of the reviewed studies.
Condición actual en la Reserva de la Biósfera Maya, tradición y reelaboración para una visión integrada de patrimonio mixto
Authors: Quintana Samayoa Oscar Antonio , Siller Camacho Juan Antonio
Published: June 2020

In order to study its conditions, since 1987 the authors have monitored the Prehispanic buildings located in the Maya Biosphere Reserve (mbr) in Petén, Guatemala; they have also analyzed neighboring protected areas such as the Calakmul Biosphere Reserve, in Campeche, Mexico, and others. This region of the Central lowlands is now known to possess a double heritage: cultural and natural. For the Maya Biosphere Reserve, in Guatemala, the data indicates that this mixed "ideal" management of heritage has not been successful, since the natural and environmental aspects prevail over the cultural ones. For this reason, the present work tries to give an updated view of the condition of the built heritage in the mbr and seeks to revalue the spirit of mixed management.
Etnografía de los procesos alimentarios y el poder en regiones indígenas de Chiapas
Authors: Alonso Bolaños Marina , Gutiérrez Sánchez Javier , Ledesma Domínguez Fermín , Tadeo Castro Rosalba
Published: June 2020

The objective of this article is to contribute to the ethnographic knowledge of eating habits in Tsotsil, Tseltal, Zoque and Ch’ol regions of Chiapas in the context of cultural diversity and power relationships. It shows that food as a dynamic social fact is a research field in which different scales and levels of social and political power are expressed. Likewise, inequalities between State, market system, national society and Indigenous people are manifested in the eating habits, as well as among particular regional and local contexts. The anthropological category of “control” is proposed in order to explain the relations between social experience of production and consumption of food.