bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and characterization of sequential curing with off-stoichiometric amine-diglycidyl ether of bisphenol a /novolac epoxy blended systems
Authors:   , Suttitham Pakawat
Published: March 2023

B-stage epoxy adhesives are used in many applications such as electronic devices and prepreg composites. The most common available form is in the film form, rolls, sheets, or custom preforms. In this work, B-staged epoxy adhesives were prepared by using sequential curing with off-stoichiometric amine technique. Diethylenetriamine (DETA) was used as the curing agent for the first curing step. While dicyandiamide (DICY) was used as the latent curing agent for the second curing step and 3-(3,4-dichlorophenyl)-1,1dimethylurea (DIURON) as accelerator for reducing the curing temperature of DICY. Novolac epoxy was blended in diglycidyl ether of bisphenol A (DGEBA) with various ratio of 0 – 50 phr to enhance the glass transition temperature (Tg) and thermal stability. Non-isothermal differential scanning calorimetry (Non-iso DSC) showed simultaneous presence of two curing agents with two different curing reaction without interference. In addition, thermal stability and Tg were improved with increasing in Novolac epoxy content. However, blending ratio more than 30 phr of Novolac epoxy was practically difficult to proceed due to high viscosity, which is not suitable for film casting process at room temperature. Therefore, the weight ratio 70/30 of DGEBA/Novolac blended was then selected for further investigation owing to its acceptable Tg of 144 °C, thermal degradation at 5 % weight loss (Td5) of 355°C and suitable viscosity for use in film casting process at room temperature. Fourier-transform infrared (FTIR) spectroscopy showed that the inactivity of latent curing agent and accelerator in the B-staged. The storage stability test showed only 8.72 % change in heat of curing reaction and able to adhere with substrate after B-staged for 28 days storage at freezer (-18 °C).
Stability Enhancement of CsPbBr3 Quantum Dots by Coating TiO2 as a Surface Encapsulation
Authors:   , Nuket Parina
Published: March 2023

The cesium lead bromide quantum dots (CsPbBr3 QDs) have exhibited the excellent optical properties which have been widely used in the applications of optoelectronic and photoelectrochemical devices. However, the instability of CsPbBr3 QDs against the environment factors has been a major obstacle hindering the commercialization of corresponding devices. Herein, the new encapsulation process, in-situ method, for CsPbBr3/TiO2 was presented to prevent the agglomeration of the particles and improve the stability of CsPbBr3 QDs without heat treatment at high temperature. The CsPbBr3 QDs were coated with TiO2 by using titanium tetraisopropoxide (TTIP) as a titanium source which was injected during the formation of CsPbBr3 QDs in which the effects of TTIP injection temperature from 25°C to 170°C were studied. The morphological, structural, and optical properties of CsPbBr3/TiO2 prepared by in-situ method were compared with ex-situ method reported in previous study. Besides preventing an aggregation, the in-situ TiO2 coated sample at 25°C exhibited the excellent stability against ambient air, non-polar solvent, water and visible light illumination owing to the protection of TiO2 deposited on the CsPbBr3 QDs surface and the good structure of CsPbBr3 QDs. Finally, the photoelectrochemical results showed that the in-situ coated sample at 100°C had the highest charge transport property among the others.
ANALISIS KEBUTUHAN PROJECT BOOK BERBASIS PJBL-STEAM PADA MATA KULIAH METODE EKSPERIMEN FISIKA
Authors: Rasmi Dian Pertiwi , Hendri Menza , Nasution Okta Senira Mamora
Published: March 2023

Pentingnya ilmu eksperimental baik untuk peneliti maupun mahasiswa menyebabkan mata kuliah metode eksperimen fisika perlu di evaluasi dan dikembangkan salah satunya adalah dengan melakukan analisis permasalahan mendasar dan solusi yang tepat dalam bentuk menemukan kebutuhan bahan ajar yang sesuai untuk dikembangkan. Jenis penelitian yang digunakan adalah penelitian kualitatif dengan subjek penelitian yakni mahasiswa angkatan 2020. Dan teknik pengambilan data yakni dengan melakukan wawancara secara tidak terstruktur dengan butir pertanyaan yakni pertanyaan terbuka. Analisis data dilakukan secara deskriptif sehingga data akan di susun dalam pola tertentu dan membuat kesimpulan dengan cara naratif. Didapatkan bahwa masalah mendasar dari mata kuliah tersebut adalah tidak adanya pedoman pembelajaran sehingga pembelajaran berlangsung dengan tidak sistematis sehingga diperlukan sebuah bahan ajar yang dapat memadukan antara STEAM dan PjBL. Dengan adanya penelitian ini maka akan dilanjutkan dengan penelitian berikutnya mengenai pengembangan Project Book berbasis STEAM-PJBL yang diharapkan dapa menjawab semua persoalan yang terdapat dalam mata kuliah tersebut.
ONDE ESTÁ A ALMA HUMANA?
Authors: Van Vlastuin Willem
Published: March 2023

É corajoso de sua parte levantar a questão da evolução em relação à fé cristã, sabendo de antemão que este é um assunto delicado. É por isso que é tentador silenciar sobre esse tema e nos preocupar com toda sorte de sutilezas. No entanto, você não está preocupado com mais uma interpretação de Calvino, mas está levantando um tema que pertence ao cerne da teologia. Segundo Martinho Lutero, o primeiro artigo de fé era o mais importante porque na doutrina da criação recaem todas as decisões teológicas.
Religião e ciência são relacionadas ou contraditórias?
Authors: Arief Murditanto Rachmat
Published: March 2023

Muitos de nós pensamos que ciência e religião estão relacionadas. Há também aqueles que pensam que não estão relacionados entre si. Então qual é o certo?
Review Jurnal: Does Time Spent Using Social Media Impact Mental Health?: An Eight Year Longitudinal Study
Authors:   Sekolah Tinggi Multimedia (MMTC), Yogyakarta, Indonesia, Putro M. Rizqi Pranoto
Published: March 2023

The rise of the use of social media has become part of the development of adolescent life. Many people say that the massive use of social media affects the mental health of adolescents. Even so, there is no research that conclusively states that various adolescent mental health problems are caused entirely by social media use. This is mainly because the research conducted is still cross-sectional in nature and ignores long-term changes so that many factors can influence simultaneously. This paper reviews a scientific article entitled: Does Time Spent Using Social Media Impact Mental Health?: An Eight-Year Longitudinal Study (Coyne, Rogers, Zurcher, Stockdale, & Booth, 2020). This study tries to investigate over a long period of time, whether the use of social media affects mental health in adolescents? Or is there something else that is the real cause? And how should the use of social media not harm teenagers?
Sustainability and product life cycle in circular economy
Authors: Aleksić Aleksandra , Jovanović-Vujatović Milica , Veselinović Nemanja
Published: March 2023

Circular economy and business according to its principles are gaining in importance in increasingly competitive business conditions. The main goal of the company is to make a profit through respect for the environmental and social dimensions. Through sustainable development and the application of the zero-waste principle, the emphasis is shifted to production that saves resources and uses renewable energy. The aim of this paper is to emphasize the connection between sustainable development and circular economy, as well as the possibility of extending the life of products and raw materials through the concept of the circular economy. The importance of this topic stems from the need to align economic goals with the goals of preserving resources and the environment. The main purpose is to show the connection between sustainable development and the circular economy, as well as to point out how compliance with standards and recommendations can help in the transition from a linear to a circular way of doing business.
Events and sustainability: Why and how to organize green events?
Authors: Seočanac Marijana
Published: March 2023

This paper aims to identify the importance of organizing green events from the perspective of different stakeholders, as well as possible solutions that event organizers can use to make their events greener. The large number of people who gather, the short duration, and the significant impact they have on the environment in which they are held, have led to the fact that events are often considered the "antithesis of sustainability". This paper seeks to review the literature to determine the relationship between events and sustainability, and then, on the example of the Belgrade Beer Fest, to identify ways that, even events that are not primarily organized for this reason, can contribute to improving the sustainability of the destination.
The role of radiotherapy in the treatment of Ewing sarcoma of bone
Authors: Filipović Predrag , Popović-Vuković Marija , Nikitović Marina
Published: March 2023

Ewing sarcoma (ES) is the second most common primary bone malignancy after osteosarcoma. The disease most often occurs in adolescence, with peak incidence around the age of fourteen. The most common primary location of the tumor is the bones of the pelvis, followed by the ribs, spine and long bones of the extremities such as the tibia and the fibula. ES shows a tendency towards hematogenous dissemination, primarily in the lungs and bones, much less often lymphogenously. One third of patients have distant metastases present at initial diagnosis, which is why ES is considered a systemic disease. The treatment of Ewing sarcoma is based on a multimodal approach that includes the use of chemotherapy, surgery and/or radiotherapy. The identification of prognostic parameters enabled the individual treatment of patients based on the assessed risk group. With the application of modern therapeutic protocols, five-year survival for patients with localized disease lies between 60% and 68%, while for patients with metastatic disease, five-year survival is still unsatisfactory and is around 17%. ES belongs to the group of radiosensitive tumors, and radiotherapy plays a very important role in the local control of the disease, in combination with surgical treatment or independently, and can be applied as radical, preoperative or postoperative radiation therapy. Also, radiation therapy has a role in the palliative approach to the treatment of lung metastases and other metastatic sites. Considering that the modern multimodal treatment of Ewing sarcoma leads to long-term survival, it is necessary to take into account the expected side effects of the therapy that can reduce the quality of life of treated patients. Modern radiotherapy techniques such as three-dimensional conformal radiation therapy (3D CRT), intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) enable precise delivery of the prescribed dose of radiation to target volumes with better sparing of surrounding normal tissues and organs, which leads to a lower incidence of late sequelae of radiation therapy and enables the preservation of the quality of life of treated patients.
The impact of the covid-19 pandemic and social isolation on behavior and mental health of medical and nonmedical staff: Experience from a gynecology and obstetrics clinic
Authors: Aničić Radomir , Rakić Aleksandar , Sretenović Dragutin , Kocić Jovana , Štulić Jelena , Ristić Aleksandar , Dimitrijević Dejan , Nejković Lazar
Published: March 2023

Introduction/Aim: Occupational exposure makes health workers m vulnerable and at high-risk for COVID-19 infection and major psychological disturbance. Fear from the unknown, anxiety for close family and friends, rapid exhaustion of protective equipment, direct contact with infected patients, in combination with media-provoked panic, create a considerable psychological burden in healthcare workers. The aim of this study was to assess mental health of medical and non-medical staff of a university gynecology and obstetrics clinic during COVID-19 epidemic in Serbia. Methods: The study was conducted from 1st to 31st of May 2020 through 160 online questionnaires distributed among the staff of Obstetrics and Gynecology Clinic Narodni front. This online survey consisted of two sections: one included questions related to demographic characteristics, medical history, behavior and habits during the COVID-19 pandemic, while the other comprised questions included in Depression, Anxiety and Stress Scale 21 (DASS-21). Results: Among 118 employees who had participated in the study, depression, anxiety, and stress were present in 35.6%, 40.7%, and 27.1% participants. Participants with lower education had higher total DASS, depression, anxiety, and stress scores compared to participants with higher education. Non-medical staff had significantly higher total DASS and anxiety scores than medical staff. Participants with lower education and married subjects were more likely to have anxiety and depression symptoms. Conclusion: Apart from medical staff, non-medical personnel and their mental status should not be neglected, and we believe that future studies related to the psychological impact of public health emergencies, should include this group.
Evaluating the clinical application of PAMD score in the assessment of TRUS-biopsy positive outcomes in patients with PSA 4-10 ng/ml treated in Serbia
Authors: Radovanović Milan , Zubelić Aleksa , Šantrić Veljko , Milojević Bogomir , Bumbaširević Uroš , Stanković Branko
Published: March 2023

Introduction: Transrectal ultrasound-guided prostate biopsy (TRUS-biopsy) is the "gold standard" in the diagnosis of prostate cancer (PC). There is much divided opinion on the need for biopsy in patients with prostate-specific antigen (PSA) between 4 and 10 ng/ml. The positive biopsy outcome (PC) in these patients ranges from 20 to 39%. Low sensitivity and specificity of PSA in predicting positive biopsy outcome results in a large number of unnecessary biopsies and treatments. In order to better select candidates for biopsy, several risk stratification models for PC have been proposed in recent years, among them the PAMD score. Aim: The aim of this study was to examine the value of the PAMD score in the assessment of positive biopsy outcomes in our population of patients, as well as to examine individual risk factors for PC in patients with PSA values between 4 and 10 ng/ml treated in Serbia. Material and methods: The study involved 50 patients at the Clinic of Urology, University Clinical Centre of Serbia, whose PSA value were measured in the range from 4 to 10 ng/ml. In all the patients we measured PSA and %fPSA, and performed DRE, as well as magnetic resonance imaging (MRI) to evaluate prostate volume (PV) and PI-RADS score. All patients underwent TRUS-guided systemic prostate biopsy. In accordance with the data from literature, PAMD score was determined for all the patients. Results: A PAMD score > 3 showed a high specificity in the prediction of PC, as well as an association with a higher frequency of highgrade PC. A positive finding on DRE, %fPSA< 16, age above 69 years and PI-RADS > 3 showed a statistically significant association with the existence of PC. A high individual predictive value in assessing the presence of PC was confirmed for DRE, %fPSA, PV, and PI-RADS score. Conclusion: The PAMD scoring system may be of importance for better selection of candidates for TRUS-biopsy, in the population of patients with PSA values 4-10 ng/ml.
Assessment of timely detection of abdominal aortic aneurysm in Serbian population based on the data from Serbvasc registry of operated patients
Authors: Pešić Slobodan , Tanasković Slobodan , Stepanović Nemanja , Joković Vuk , Tomić Aleksandar , Babić Srđan , Roganović Andrija , Popović Miroslava , Končar Igor
Published: March 2023

Introduction Screening of males over 65 years of age for abdominal aortic aneurysm (AAA) has been proved effective in some countries. The incidence of AAA in Serbian population has not been evaluated yet. The aim of the study was to assess the ratio between elective and urgently operated patients with AAA and to estimate hospital incidence of treated AAA based on the population of 100 000 inhabitants. Methods Data were obtained from Vascular surgery registry - Serbvasc which has been created by 17 institutions. Data containing demographic characteristics were obtained from the publication of the Statistical office of the Republic of Serbia. For statistical analysis, the methods of descriptive statistics were used and the values were expressed per 100 000 inhabitants. Results During the year 2021, 422 operations were performed in 7 hospitals due to asymptomatic, symptomatic and ruptured AAA in 323 (76,54%), 37(8,76%) and 62 (14,69%) patients, respectively. Hospital incidence of electively operated AAA is 8,06 cases per 100 000 inhabitants, whereas the incidence of operated ruptured AAA is 1,55 cases per 100 000 inhabitants. Overall hospital incidence of all operatively treated AAA is 10,53 cases per 100 000 inhabitants. Out of the total number of operated patients with AAA, 134 (31,75%) were younger than 65 years, while 22 (35%) out of 62 patients treated for rAAA, where younger than 65 years. Conclusion The incidence of operatively treated elective AAA is lower than the values reported in literature, while the rate of ruptured AAA is more than twice as high as the rate reported by recent papers. One third of treated patients were younger than 65 years. The most efficient strategy for reducing the number of urgently treated AAA is the implementation of screening for AAA in groups with higher risk.
Selected quality factors in the function of creating guests' satisfaction
Authors: Vujić Tamara , Vujić Milan , Zrnić Miloš , Gajić Tamara , Vukolić Dragan
Published: March 2023

The quality of service is an ongoing problem of research in the world in all service sectors and dictates potential expectations among guests and their satisfaction. Pursuant to the problem and theoretical setting of similar research, the authors identified the quality factors of hotel service in Divčibare, to determine their impact on guest satisfaction. Methods used in research are descriptive and regressive analysis. The authors used a modified questionnaire from the author of Akbab (2006), for the international community. The survey was conducted during 2022, with a total sample of 442 respondents. The study showed that the material component of the hotel service has a positive impact on the loyalty of visitors to the hotel building, in relation to the intangible component. In addition, by observing the behaviour of guests, it is possible to respond to their demands and needs which are a major factor in creating loyalty.
Do we talk to a wall or pass on knowledge to students: The advantages and disadvantages of online learning
Authors: Bojić Kristina , Brdar Ivana , Nešić Marija
Published: March 2023

In the era of digitalization, boosted by Covid-19 pandemic, there is a constant need to measure the success of digital education, compare and reappraise its positive and negative outcomes, which are mainly dependent on the technical conditions available, as well as on the extent to which the previous knowledge of teachers has been adapted to practical and technical challenges. The aim of this paper is to present an analysis of the advantages and disadvantages of digitized education as perceived by students in a qualitative survey, conducted in 2021/22. The starting point were two hypotheses related to positive aspects and two hypotheses related to negative aspects of online learning. An in-depth interview was conducted among 20 high school and 20 university students. By analyzing the results obtained, and juxtaposing them with the data taken from a quantitative survey administered prior to the qualitative one, in 2020/21, it is possible to compare the changes that took place and gain a better insight into the entire process, which has undergone certain improvements, but which also leaves room for further enhancement, particularly in terms of students' and teachers' motivation to actively engage and interact. This would help students overcome their distrust of online education.
Corruption and economic growth in the Republic of Serbia
Authors: Čudan Aleksandar , Kekić Dalibor , Dimitrijević Dragomir
Published: March 2023

Corruption is a phenomenon that causes strong economic, political, social and moral deviations in modern society, and for these reasons it represents a very relevant topic of research. Economic science is a powerful tool for analysing corruption, and the economic approach is of fundamental importance for understanding where the incentive for corruption is the greatest and where its influence is the most pronounced. Opposing all forms of economic destruction would facilitate the functioning of the economic system, simultaneously generating fiscal revenues, and a true commitment to the fight against corruption, strengthening the rule of law, improving the efficiency of institutional reforms and the judicial system would encourage long-term economic growth. The transition is also one of the significant factors that initiates the expansion of corruption in numerous young transitional states, including the Republic of Serbia. Therefore, the essential goal of this paper is to collect and offer a wider range of information and knowledge about the genesis of the problem. Proceeding from the previously defined problem, the hypothesis on which this work is based is as follows: so far, theoretical and practical research on the impact of corruption on economic growth confirms that the relationship between corrupt practices in our country and basic macroeconomic and microeconomic indicators is inversely proportional.
Determination of the service price for plowing Based on the cost of mechanization
Authors: Koprivica Ranko , Marić Marko , Zečević Stefan , Veljković Biljana , Gavrilović Marija , Terzić Dragan
Published: March 2023

In the paper, using the example of "Zlatibor Ecoagrarian", in the machinery ring "Agrotechnical Center", the analysis of the operating costs of mechanization and the calculated service price of plowing (without VAT) are shown, all with the aim of optimal use of existing agricultural machinery and renting. The total cost and price of plowing per working hour (€/h) were calculated based on the fixed ownership and variable operating costs of the Lamborghini Spire 80 Trend tractor (58 kW) and the Kuhn Master 103-3T double-row plow. The annual cost for the tractor was €19,004 and for the plough €1,993. Based on an annual use of the tractor of 400 hours and the plough of 120 hours, the price of the tractor-machine unit for plowing was calculated to be 64.12 €/h. This price for plowing is composed of the cost of the tractor 47.51 €/h or 74.09% and the plough 16.61 €/h or 25.91%. In the calculation structure of the total cost of the tractor, variable costs account for 61.08%, fixed costs account for 23.88%, workers' wages account for 6.54%, and profit margin accounts for 8.50%. The fixed cost of the plough accounts for 85.07% of the total cost and the variable 14.93%, excluding the cost of fuel, lubricants, wages and profit margin, as they are already included in the variable cost of the tractor. The paper presents one of the ways to calculate the operating costs of a tractor-machine unit in basic tillage. On this basis, farmers can rationally decide whether it is more profitable for them to buy a new tractor and plough or to use other farmers' plowing services and machinery rings.
Prediction of tomato yield and water productivity under deficit irrigation scenarios using AquaCrop model in Afaka, Kaduna, Nigeria
Authors: Obiajulu Onwuegbunam , Abubakar Oyebode , Igbadun Henry , Ismail Habibu
Published: March 2023

Improving water productivity through deficit irrigation has become a major goal for sustainable agriculture amidst global decline in water availability. The study evaluated the yield, crop water use and water productivities of field-grown drip-irrigated tomato in response to regulated deficit irrigation, and subsequent simulation under different deficit and irrigation method scenarios, using AquaCrop model, in Afaka, Nigeria. The field experiment, laid in randomized complete block design, comprised three deficit irrigation levels (80, 60 and 40% of reference evapotranspiration, ETo) imposed at the vegetative, flowering and maturity growth stages, with 100% ETo at the three crop growth stages as the control. The highest fresh fruit yield (19.0 t/ha) was obtained irrigating with 100% ETo value at all growth stages but the highest water productivity of fresh fruit (4.94 kg/m3 ) was obtained irrigating with 60% ETo at maturity stage, then full irrigation at vegetative and flowering stages. On fruit dry yield basis, the highest simulated crop water productivity (0.46 kg/m3 ) for the deficit scenarios was obtained irrigating with 80% ETo at all the three growth stages, having the highest fruit dry yield (1.67 t/ha) and the lowest seasonal water applied (447 mm). Under the scenarios of irrigation methods (drip, basin and furrow), the fruit dry yield was similar in each treatment, but water productivity was highest (0.53 kg/m3 ) under drip irrigation system. Irrigating with 80% ETo at all the entire crop growth cycle of UC 82B tomato is recommended for the highest crop water productivity.
The clinical features of pneumonia in patients with chronic obstructive pulmonary disease
Authors: Milovanović Vesna , Adžić-Vukičević Tatjana , Milić Marija , Filimonović Jelena , Dimitrijević Dragana , Jelić Marina , Stošić Maja
Published: March 2023

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, causing 3.23 million deaths in 2019. The incidence of pneumonia in patients with COPD is almost twice as high as in the general population. Globally, pneumonia is a cause of increased mortality and morbidity rates. A higher incidence of pneumonia and its association with increased mortality and more frequent hospitalizations, which increases the costs of treatment, has been observed in people diagnosed with COPD in comparison to the general population. The aim of this study was to examine the basic clinical features of pneumonia in patients with COPD, as well as to assess the differences in the clinical characteristics of COPD patients in relation to the presence of pneumonia. The study was designed as a case-control study. The study included patients hospitalized and treated at the pneumophysiology department of the Health Center in Kosovska Mitrovica, in the period from January 2017 to December 2019. Data for research purposes were obtained from the patients' medical records. The study included 110 patients with COPD, of which 30 (27.3%) had pneumonia and 80 (72.7%) were not diagnosed with pneumonia. Out of the total number of patients, 65 (59.1%) were males. Patients with pneumonia had statistically significantly lower mean values of leukocytes and neutrophils at admission, and significantly lower hematocrit values at discharge in comparison to patients without pneumonia. COPD patients who had pneumonia were significantly more often treated with antibiotic combination therapy (cephalosporins and fluoroquinolones) and macrolides. Statistically significantly, the most common auscultation findings in patients with COPD and pneumonia included low-pitched and polyphonic wheezes, and complications in the form of effusions and abscesses were also significantly more often registered. In addition to prolonged hospitalization, patients with COPD and pneumonia received significantly lower doses of oxygen compared to COPD patients without pneumonia. Our study shows that pneumonia is highly prevalent and requires long-term hospitalization and treatment, which leads to increased costs, however, it can be cured with adequate treatment, primarily using a combination of several antibiotics.
Long-term survival of patients with acute myocardial infarction
Authors: Đurković Sanja , Đurić Petar , Šipetić-Grujičić Sandra , Maksimović Jadranka , Vujčić Isidora
Published: March 2023

Over the past decade, percutaneous coronary intervention and medication have decreased mortality in patients with acute myocardial infarction (AMI). Despite this progress, AMI is still the main cause of mortality both globally, and in Serbia. Social-demographic characteristics and co-morbidities of patients are linked to increased risk from death and repeat AMI. This paper analyses the long-term survival of patients with AMI depending on their risk factors, clinical characteristics and lifestyle. This study looked at the survival of 135 patients who had suffered AMI and were first hospitalized at the Emergency Centre of the University Clinical Centre of Serbia in Belgrade, in its coronary unit, in the period 2002-2006. Their survival was tracked until 1 September 2011, and continued to 1 January 2020 by phone, to ascertain whether the patients were still living or had passed away. The data on patient characteristics were collected using a questionnaire. The results were analysed using the ch2 test, Kaplan-Meier curve and multivariate Cox regression model. During the average follow-up period of 164 months, 60 patients (48.0%) had passed away. Patients who survived were statistically significantly younger, their frequency of diabetes mellitus (DM) was statistically significantly lower and they were statistically significantly less likely to have lived alone. According to the results of the multivariate Cox regression model, the independent predictors of long-term all-cause mortality after an AMI were: living alone, DM in personal medical history and older age. Adequate measures of primary, secondary and tertiary prevention, as well as social support, may have an effect on the length of patient survival following an AMI.
Personality characteristics of adolescents with internet addiction disorder
Authors: Milić Jelena , Dimović Anđelija
Published: March 2023

The discussion about whether the internet addiction disorder should be considered a primary addiction disorder or a secondary disorder due to other psychiatric illnesses is a very current topic. Although the term "addiction" has historically been associated with the pathological use of psychoactive substances, research over the past few decades indicates that various behaviors are also part of the spectrum of addiction. Accordingly, addictions to psychoactive substances and behavioral addictions overlap in several segments, but there are also certain differences between them. Taking into account these statements, the subject of this research was the analysis of the personality structure of Internet addicted adolescents, aimed at identifying if there are specific differences in certain personality dimensions between adolescents addicted to the Internet (reference group) and adolescents who abuse psychoactive substances, as well as in adolescents from the non-clinical population. The methodology was applied to a sample consisting of 125 respondents of both genders, aged 13 to 24, of whom 27 were from the clinical group of Internet addicts, 24 from the clinical group of psychoactive substance addicts, and 74 from the non-clinical population. A questionnaire was used for assessing Internet addiction (Internet Addiction Test) and a questionnaire for assessing the personality of adolescents (Belgrade Personality Inventory of Adolescents). The results indicate that we cannot talk about a specific profile that distinguishes respondents who are addicted to the Internet. However, despite the limitations, significant differences in certain dimensions indicate certain deviations between groups of adolescents with Internet addiction, addiction to psychoactive substances and the non-clinical population. Low research curiosity, poorly developed perseverance and goal orientation play a significant role in the aetiopathogenesis of Internet addicts. We conclude that the obtained results can have a significant role in solving the current dilemma whether Internet addiction disorder should be considered a primary addiction disorder or a secondary disorder due to other psychiatric diseases.
Quality of healthcare at the Institute for Orthopedic Surgery Banjica
Authors: Baščarević Zoran , Nikolić Vesna , Janković Đorđe
Published: March 2023

The World Health Organization defines the quality of healthcare as a "degree to which healthcare services increase the likelihood of desired health outcomes for individuals and populations". Healthcare quality indicators are statistical and quantitative measures of healthcare processes and outcomes used to monitor, evaluate and improve the quality of patient treatment and care. They are determined according to the healthcare organisation level, types of health institutions and branches of medicine. This article presents a trend analysis of the selected healthcare quality indicators at the Institute of Orthopaedic Surgery Banjica (IOS Banjica) for the period from 2008 to 2021 in the light of the impact of the implemented quality improvement measures. A comparative review of healthcare quality indicators was also made for 2019 for IOS Banjica and similar tertiary institutions: Clinic for Orthopaedic Surgery and Traumatology of Clinical Centre of Vojvodina, Clinic for Orthopaedic Surgery and Traumatology of the Clinical Centre of Serbia, Orthopaedic Surgery and Trauma Centre of the Clinical Centre of Kragujevac and Orthopaedic and Trauma Clinic of the Clinical Centre in Niš to gain an insight of the situation in different institutions prior to COVID-19 and analyse the most common indicators. The following quality indicators have been analysed: average length of hospital treatment, average number of preoperative hospital days, rate of first outpatient appointments, rate of decubitus, and percentage of nurse's discharge letters. When interpreting the results, it should be taken into account that IOS Banjica operated as a COVID hospital in three periods in 2020 and 2021, which had a significant impact on its operation at this time. Analysis of work quality indicators for the period from 2008 to 2021 showed an improvement in the quality of work of IOS Banjica. In comparison with other similar institutions, IOS Banjica monitored more work quality indicators in the previous period. Despite the numerous problems the healthcare system has faced in recent years, IOS Banjica has managed to maintain a quality improvement trend and to make a great contribution, both through its teaching and scientific work, as well as its surgical work, seeking to provide the maximum level of expertise, quality and dedication to its patients through continuous training of staff and use of state-of-the-art technology and implants.
Prohibition of discrimination and hate speech in the educational context in Serbia
Authors: Kovačević Milica
Published: March 2023

The right to education, as one of the rights inherent to all human beings, necessarily implies an educational process that takes place in an institution that does not tolerate discrimination or hate speech. During the previous decades, both at the European and global level, relevant standards have been established in order to obtain an educational system that adequately opposes the phenomenon of discrimination, while nurturing a climate and culture conducive to the full development of students' personal potential. Having in mind the importance of preventing discrimination and hate speech in educational context, the authors have conducted a study aimed at the comparative analysis of the international and Serbian anti-discriminatory regulatory framework in the educational settings. Normative-dogmatic and comparative methods have been applied, with the focus on the systematic interpretation of the meaning and content of the studied norms. The key results of the research indicate that the domestic national framework corresponds with the relevant international standards. However, national regulations, contrary to internationally accepted paradigms, do not pay adequate attention to the intercultural elements of the educational process, because they are focused on prohibitions and post festum interventions on discrimination and hate speech.
Developing empathy in adolescents with the aid of film art
Authors: Simonyi Gabriella
Published: March 2023

Empathy is a very important prosocial behavior, a part of emotional intelligence and it is necessary for the formation of well-functioning relationships, so that we can work together with others. Empathetic children are more successful in their own social environment and make friends more easily. Empathy is not a fixed personality trait, although there are innate differences in people's social sensitivity. Empathy can also be developed, which requires the right environment and siblings and adults and time to develop. The atmosphere of the family and the wider environment, the behavior of the adults, their relationship with each other and with children is the key, which children also see and learn from it (Borba, 2018). In order to develop empathy in adolescents, we went towards the psychology of art, to see the impact, the relationship of film for developing empathy. Therefore, in the first, theoretical chapter of the work, the taxonomy of film reception by viewers is presented from the perspective of psychology of art, film and theoretical works, empirical results of literary aesthetics, psychological interpretation of empathy and mentalization. The goal of our research is to support the theory that empathy and affective influence are greater in viewers who can more intensely identify with the film's protagonists. We had other goals: to analyze the effects of character identification and to study the relationship between identification and empathy. The results of Vische and Tan (2009), support that the emotional experience is significantly determined by the genre of the film. Examining the collected data, we can conclude that there are statistically significant differences between genres in terms of identification with the male protagonist, and the identification with the hero of the film is stronger in individuals who watched the thriller.
Supersymmetry
Authors: Fabiano Nikola
Published: March 2023

Introduction/purpose: Supersymmetry is a symmetry of the Lagrangian that goes beyond Lie groups. It allows the exchange of bosons and fermions. The most important model is the Minimal Supersymmetric Standard Model, or MSSM. Methods: Supercharge algebra, superfields, Grassmann numbers, Berezin integral. Results: Supersymmetric transformations are global, they do not depend on spacetime coordinates. In the case of Supergravity, they are local. Conclusion: Supersymmetric models, and MSSM in particular, could describe more physics and more particles beyond the Standard Model.
Maximum electric field estimation in the vicinity of 5G base stations before their start-up
Authors: Lebl Aleksandar , Budimir Đurađ
Published: March 2023

Introduction/purpose: This paper presents initial development of the procedure for electric field estimation in the vicinity of 5G base stations. Methods: The procedure allows determination of future radiation levels before traffic is established over applied antenna systems on the basis of measured values of electric field levels caused by the signal forming Synchronization Signal Block. It is possible to perform necessary calculations for a very accurate estimation even if some important parameters of the radiation characteristics (such as the frequency span between the frequency carriers on the radio interface) are not a priori known. In this way, communication with mobile system operators before measurement is significantly simplified because operators do not need to know system technical details. Results: The developed formula for electric field estimation is verified comparing the calculated values by its implementation to the practical results obtained by intensive measurements on a great number of 5G base stations in a highly developed country. The formula gives a pessimistic result, i.e. a higher electric field level than it is obtained by all such performed measurements. Conclusion: This estimation allows mobile system operators to predict whether the electromagnetic field around base stations could be dangerous for human health when systems come to full operation while considering national and international recommendations dealing with radiation levels.
Mathematical modeling and simulation of a rectangular pulse transceiver operating in the discrete-time domain
Authors: Berber Stevan
Published: March 2023

Introduction/purpose: The paper presents the theory and design issues of a discrete-time communication system used for discrete-time pulse transmission with and without filtering. Signals are analyzed in both the time domain and the frequency domain. Methods: The system is theoretically analyzed using block schematics expressed in terms of mathematic operators and the system simulation is performed to confirm the theoretical findings. Results: Discrete-time signals are presented in the time domain and the frequency domain as well as confirmed by a simulation designed in Matlab. Conclusion: The results of the paper contribute to the theoretical modeling and design of modern discrete communication systems.
Modeling and simulation of hydraulic buffering valve for power-shift transmission
Authors: Drakulić Momir , Đurić Aleksandar , Ponorac Luka , Benmeddah Abdeselem , Perić Sreten
Published: March 2023

Introduction/purpose: The hydraulic buffering valve has the greatest influence on the dynamic characteristics of power-shift transmission. The hydraulic buffering valve is a transmission element that controls increase in pressure in friction assemblies during the gear shifting process. By choosing the optimal control of pressure increase during shifting, reduction of dynamic loads in gear transmissions and thermal loads in friction assemblies is achieved. Methods: The paper analyzes the principle of one of hydraulic buffering valve solutions as well as the influence of certain parameters on the control of pressure increase. After the analysis of the working principle of the hydraulic buffering valve, a simulation model was developed in the MATLAB/Simulink software package. Results: The results obtained using the simulation model were compared with the experimental results of the selected pressure modulator solution. The selected hydraulic buffering valve was developed as part of the development of a device for power-shift transmission. The simulation results showed a satisfactory match with the experimental results. Conclusion: The developed simulation model enables a relatively easy and quick change of the parameters of the hydraulic buffering valve as well as a possibility of a faster and better understanding of the influence of individual parameters on pressure increase during the gear shifting process.
Gastrointestinal endoscopy’s carbon footprint
Authors: Park Su Bee , Cha Jae Myung
Published: March 2023

Climate change is a global emergency. Consequently, current global targets to combat the climate crisis include reaching net-zero carbon emissions by 2050 and keeping global temperature increases below 1.5 ˚C. In 2014, the healthcare carbon footprint was 5.5% of the total national footprint. Gastrointestinal endoscopy (GIE) has a large carbon footprint compared to other procedures performed in healthcare facilities. GIE was identified as the third largest generator of medical waste in healthcare facilities for the following reasons: (1) GIE is associated with high case volumes, (2) GIE patients and relatives travel frequently, (3) GIE involves the use of many nonrenewable wastes, (4) single-use devices are used during GIE, and (5) GIE is frequently reprocessed. Immediate actions to reduce the environmental impact of GIE include: (1) adhering to guidelines, (2) implementing audit strategies to determine the appropriateness of GIE, (3) avoiding unnecessary procedures, (4) using medication rationally, (4) digitalization, (5) telemedicine, (6) critical pathways, (7) outpatient procedures, (8) adequate waste management, and (9) minimizing single-use devices. In addition, sustainable infrastructure for endoscopy units, using renewable energy, and 3R (reduce, reuse, and recycle) programs are necessary to reduce the impact of GIE on the climate crisis. Consequently, healthcare providers need to work together to achieve a more sustainable future. Therefore, strategies must be implemented to achieve net-zero carbon emissions in the healthcare field, especially from GIE, by 2050.
Effect of gonadotropin-releasing hormone agonist treatment on near final height in girls with central precocious puberty and early puberty
Authors: Yang Eun Hye , Jo Ha Young , Park Su Jeong , Yoo Hye Won , Choi Soo-Han , Kim Hye-Young , Park Kyung Hee , Kim Young Mi , Kwak Min Jung
Published: March 2023

Purpose: The aim of this study was to examine whether gonadotropin-releasing hormone (GnRH) agonist treatment is effective in preserving final height in patients with central precocious puberty (CPP) or early puberty (EP).Methods: The medical records of 40 patients with CPP and 206 patients with EP who completed GnRH agonist treatment following diagnosis were analyzed retrospectively. Height and height standard deviation (height SDS) scores based on bone age (BA) were measured and calculated at baseline, after treatment completion, and at final follow-up to compare changes within and between groups. Predicted adult height (PAH) was estimated by the height corresponding to height SDS for BA in girls at 18 years 11 months of age based on the growth chart.Results: PAH at baseline did not differ significantly between the CPP group (153.67±4.95) and the EP group (154.77±3.72). In the CPP group, PAH significantly increased at treatment completion (156.01±4.61) and at final follow-up (158.52±6.04) compared to baseline. In the EP group, PAH significantly increased at treatment completion (157.7±3.60) and at final follow-up (159.31±4.26) compared to baseline. The increase in PAH at all timepoints compared to baseline did not significantly differ between the CPP and EP groups.Conclusion: Both CPP and EP groups had significantly greater PAH after treatment, with no difference in the amount of increase between groups. These results show that GnRH agonist treatment can help increase final height even in patients diagnosed with EP after the age of 8 years.
The prevalence of diabetic peripheral neuropathy in youth with diabetes mellitus
Authors: Sophausvaporn Piengjai , Boonhong Jariya , Sahakitrungruang Taninee
Published: March 2023

Purpose: Diabetic neuropathy (DN) is a serious complication in diabetes mellitus. We aimed to determine the prevalence of DN in pediatric-onset diabetes in a tertiary care center and to assess the sensitivity and specificity of monofilament testing and noninvasive screening to diagnose DN compared with the gold standard nerve conduction study (NCS).Methods: Sixty-five Thai children and adolescents (39 females) diagnosed with diabetes before 15 years of age were included. All subjects were screened for DN by foot and neurological examinations, light touch sensation by 10 g Semmes-Weinstein monofilaments, and the Michigan Neuropathy Screening Instrument (MNSI). NCSs were used as the gold standard for diagnosis of DN.Results: Fifty-eight patients had type 1 diabetes ( T1D), 5 patients had type 2 diabetes, and 2 patients had other types of diabetes. The mean age was 17.7±4.6 years (8–33 years). The prevalence of DN in this cohort was 12.3% by NCS. All subjects were asymptomatic. Mean diabetes duration did not differ between the groups (with DN 8.0±3.0 years vs. no DN 8.2±5.0 years). Notably, one patient with T1D developed DN within 3 years after diagnosis. Poor glycemic control was a significant risk factor for DN. Glycosylated hemoglobin was higher in the DN group (10.6%±2.3% vs. 8.5%±1.6%, P=0.008). The occurrence of diabetic nephropathy was associated with DN (prevalence rate ratio, 4.97; 95% confidence interval, 1.5–16.46). Foot and neurological examinations, monofilaments, and the MNSI failed to detect DN in all subjects with abnormal NCS.Conclusion: The prevalence of DN in pediatric-onset diabetes is not uncommon but mainly is subclinical. Poor glycemic control is the main risk factor. Noninvasive screening tests for DN exhibited poor diagnostic sensitivity in the pediatric population.