Characteristics of the serbian version of the aims2 for people with rheumatoid arthritis

Reumatoidni artritis (RA) je bolest koja u velikoj meri određuje funkcionisanje osobe zbog čega je važno ustanoviti kvalitet života ovih individua. Cilj ovog istraživanja je prevod Upitnika za procenu uticaja artritisa 2 (Arthritis Impact Measurement Scales 2) na srpski jezik, i procena njegovih mernih svojstava kod osoba sa RA u Srbiji. Istraživanje je sprovedeno onlajn krajem 2021. godine, a uzorak su činile 106 ispitanica sa RA koje su anonimno popunile online formu upitnika koji je postavljen na društvene mreže. Rezultati istraživanja pokazali su visoku pouzdanost celokupne skale, dok je objektivnost instrumenta postignuta standardizacijom načina na koji se instrument zadaje, ocenjuje i tumači. Istraživanje je pokazalo i da ne postoji statistički značajna razlika među ispitanicima iz Srbije, Hrvatske i Bosne i Hercegovine ni na jednom od subtestova upitnika, a to je ispitivano zbog eventualnih jezičkih i kulturnih razlika koje postoje. Preporuka za buduća istraživanja je ispitivanje upitnika u test-retest situaciji, uvođenje kom- plementarnog upitnika, kao i da u nekom narednom korišćenju ovog instrumen- ta na srpskom jeziku u njegovom prevodu učestvuju reumatolozi, kao i osobe koje boluju od RA.__Rheumatoid arthritis (RA) is a chronic and heterogeneous disease that largely determines a person’s physical and social functioning, which is why it is very important to establish the quality of life of these individuals. The aim of this research is the translation of the Arthritis impact measurement scales 2 (AIMS 2) into Serbian, and the assessment of its measurement properties in people with RA in Serbia. The research was conducted online at the end of 2021, and the sample consisted of 106 respondents with RA who anonymously filled out an online form of the questionnaire that was posted on social networks. The results of the research showed high reliability of the entire scale, while the objectivity of the instrument was achieved by standardizing the way the instrument is assigned, evaluated and interpreted. The research also showed that there is no statistically significant difference between respondents from Serbia, Croatia and Bosnia and Herzegovina on any of the subtests of the questionnaire, and this was investigated due to possible linguistic and cultural differences that exist. The recommendation for future research is to examine the questionnaire in a test-retest situation, to introduce a complementary questionnaire, as well as to involve rheumatologists and people suffering from RA in translation of the questionnaire into Serbian language in any future use of it

Characteristics of the serbian version of the aims2 for people with rheumatoid arthritis

Reumatoidni artritis (RA) je bolest koja u velikoj meri određuje funkcionisanje osobe zbog čega je važno ustanoviti kvalitet života ovih individua. Cilj ovog istraživanja je prevod Upitnika za procenu uticaja artritisa 2 (Arthritis Impact Measurement Scales 2) na srpski jezik, i procena njegovih mernih svojstava kod osoba sa RA u Srbiji. Istraživanje je sprovedeno onlajn krajem 2021. godine, a uzorak su činile 106 ispitanica sa RA koje su anonimno popunile online formu upitnika koji je postavljen na društvene mreže. Rezultati istraživanja pokazali su visoku pouzdanost celokupne skale, dok je objektivnost instrumenta postignuta standardizacijom načina na koji se instrument zadaje, ocenjuje i tumači. Istraživanje je pokazalo i da ne postoji statistički značajna razlika među ispitanicima iz Srbije, Hrvatske i Bosne i Hercegovine ni na jednom od subtestova upitnika, a to je ispitivano zbog eventualnih jezičkih i kulturnih razlika koje postoje. Preporuka za buduća istraživanja je ispitivanje upitnika u test-retest situaciji, uvođenje kom- plementarnog upitnika, kao i da u nekom narednom korišćenju ovog instrumen- ta na srpskom jeziku u njegovom prevodu učestvuju reumatolozi, kao i osobe koje boluju od RA.__Rheumatoid arthritis (RA) is a chronic and heterogeneous disease that largely determines a person’s physical and social functioning, which is why it is very important to establish the quality of life of these individuals. The aim of this research is the translation of the Arthritis impact measurement scales 2 (AIMS 2) into Serbian, and the assessment of its measurement properties in people with RA in Serbia. The research was conducted online at the end of 2021, and the sample consisted of 106 respondents with RA who anonymously filled out an online form of the questionnaire that was posted on social networks. The results of the research showed high reliability of the entire scale, while the objectivity of the instrument was achieved by standardizing the way the instrument is assigned, evaluated and interpreted. The research also showed that there is no statistically significant difference between respondents from Serbia, Croatia and Bosnia and Herzegovina on any of the subtests of the questionnaire, and this was investigated due to possible linguistic and cultural differences that exist. The recommendation for future research is to examine the questionnaire in a test-retest situation, to introduce a complementary questionnaire, as well as to involve rheumatologists and people suffering from RA in translation of the questionnaire into Serbian language in any future use of it

Numerical investigation of the influence of geometry on the thermal properties of a heat pipe

The unique property of a very high heat transfer rate in heat pipes, which originates from the phase change of a high latent heat working fluid, has led to their use in a wide range of engineering applications such as electronics cooling, heat exchangers, spacecraft and satellites etc. The zero-power demand, low weight, compactness and reliability further the benefits of their use. A small amount of working fluid inside a sealed pipe is used to transport heat with a slight temperature difference between the evaporation and condensation segments. The recirculation of fluid is realized through a wick structure and driven by capillary forces. In order to investigate the influence of the shape of the heat pipe on the rate of heat transfer, a numerical test was performed on two types of flat geometry heat pipes – square and hexagonal shaped, as well as circular and ellipsoidal shaped. The parameters of interest were pressure and temperature distribution, velocity in condensation direction and thermal conductivity distribution. Results indicate that the difference in geometry causes differences in all observed parameters, and thus significantly affects the thermal properties of the heat pipe

Electrostatic and Topological Features as Predictors of Antifungal Potential of Oxazolo Derivatives as Promising Compounds in Treatment of Infections Caused by Candida albicans

The results presented in this study include the prediction of the antifungal activity of 24 oxazolo derivatives based on their topological and electrostatic molecular descriptors, derived from the 2D molecular structures. The artificial neural network (ANN) method was applied as a regression tool. The input data for ANN modeling were selected by stepwise selection (SS) procedure. The ANN modeling resulted in three networks with the outstanding statistical characteristics. High predictivity of the established networks was confirmed by comparisons of the predicted and experimental data and by the residuals analysis. The obtained results indicate the usefulness of the formed ANNs in precise prediction of minimum inhibitory concentrations of the analyzed compounds towards Candida albicans. The Sum of Ranking Differences (SRD) method was used in this study to reveal possible grouping of the compounds in the space of the variables used in ANN modeling. The obtained results can be considered to be a contribution to development of new antifungal drugs structurally based on oxazole core, particularly nowadays when there is a lack of highly efficient antimycotics

Perspectives of the integration of an absorption refrigeration cycle in energy production system

Global warming and ozone depletion issues have had an impact on novel approaches of integrating some of the energy production systems. In present, fossil fuels such as oil, coal and natural gas still are the primary sources of energy used to provide the majority of the cooling requirements in vapor compression systems. In addition, this high energy-consumption systems work with substances that contribute to ozone layer depletion and are typically based on fluorinated gases (F gases), that as well, can have a global warming impact thousands of times greater than CO2. Much research has been done on reuse and waste heat utilization within different systems to achieve a reduction in high carbon fuel consumption. The method that aims at improving the value of the exergy of the available renewable energy sources is the absorption refrigeration cycle (ARC). With ARC, the concept of “cooling with the heat“ can be achieved, with a variety of benefits such as integration of the energy production systems, implementation of sustainable based technology in the industry of cooling, the possibility of establishing a district cooling system, etc. The cooling demands can be met through utilization of solar radiation, energy from biomass, waste heat from industrial processes, geothermal energy. In the terms of the importance of low-temperature heat sources and the reuse of heat energy, currently present researches have focus on identifying engineering and cost-effective approaches to enhance the efficiency of an integrated system. That kind of system affects the output parameters of energy production and energy consumption, so the possibilities to compare the different systems from the exergy and economic standpoint, based on the different parameters are vast. The criteria of comparison and investigation the effects of integrated systems in majority of cases would be based on: better performance at very low temperatures, carbon dioxide emissions and cost savings. Despite the existence of different obstacles, the integration of different energy production systems will have a considerable impact when it comes to overcoming the challenges in the energy sector

Development and mould technology for biocomposite structures (Application for thermoinsulated bio plates)

Biocomposite materials are a combination of two or more different biomaterials at the macroscopic level, with competitive mechanical and insulation properties, relatively stable when exposed to high temperatures and tailorable. In this paper, materials are with a vegetative part of fungi (mycelium-mesh structure of hyphae) which are increasingly used to create biocomposites with unique processing technology. The vegetative part of a fungus called mycelium, can serve as a natural binder for products made of biocomposite and acts like a self-assembling adhesive by digesting and adhering to the surface of specific organic matter. This paper presents the development of mould technology to set the biocomposite structure and test its mechanical characteristics. The primary purpose of the mould is to bring the loose natural material into a solid preparation following the standards ASTM D7250 and ASTM D1037, which include testing the technologically prepared and hardened sample for tensile and pressure. Development and moulding of biocomposite are the technological processes of drying after sowing mycelium so a variant of the mould with a perforated upper part was used to harden the samples thoroughly

Radiological and structural analysis of aluminosilicate materials incorporated with samarium (III)-oxide

This study focused on analyzing samples of aluminosilicate materials in which different percentages of samarium (III)-oxide were incorporated. Basic samples and thermally treated samples at 600 °C were analyzed. Introducing samarium (III)-oxide into the polymer matrix of aluminosilicates has been demonstrated to alter the fundamental structure of aluminosilicate materials. Interestingly, at elevated temperatures, these materials exhibit even more distinctive properties. The gamma ray spectrometric analysis results were used to conduct radiological analysis. Different methods monitor physico-chemical changes within the aluminosilicate materials. By introducing Sm3+ into the aluminosilicate matrix, the basic structure of the aluminosilicate is disturbed. The DRIFT method was used to analyze the structural properties. The analysis of the microstructural properties of the selected samples was carried out using a scanning electron microscope (SEM) and enabled the examination of the fine details of the structure of the materials thermally treated at 600 °C which resulted in the appearance of significant pores and cracks in the material.Twenty-First Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 29 – December 1, 2023, Belgrade, Serbi

Public Procurement Employees' Perception on Legal Changes, Perceived Red Tape and Job Stress: Evidence from Serbia

Public servants play an important role as guardians, guarantors, and promoters of the regime values who are in frequent contact with the citizens. Having that in mind, it is of high importance to understand their behaviour and attitudes on legal changes, perceived red tape and job stress. The aim of this paper is, therefore, twofold: firstly, to explore the influence of red tape and perceived red tape on public procurement officers’ (PPOs) and managers’ (PPMs) perception of the new Public Procurement Law in terms of its benefits to public procurement process and to their jobs and job stress, and secondly, to explore the differences between PPOs and PPMs regarding the examined statements. To answer the first question, we proposed a conceptual model which was tested using structural equation modelling (SEM), while to answer the second question we used the Mann-Whitney test. Both analyses were done using the data collected from 115 PPOs and PPMs in Serbia. The results show that PPOs and PPMs share similar attitudes regarding the existence of red tape, perceived job stress, and the influence they expect the new legislation will have on their jobs. Their expectations of the new legislation as well as their perception of job stress are found to be partially influenced by red tape. As PPOs are not that convinced that the new law will improve their job, it may be concluded that the changes the new law will bring are not substantial enough

Izazovi i prilike vodonika kao održivog vazduhoplovnog goriva budućnosti

Jedan od ključnih elemenata za proces dekarbonizacije mogla bi biti upotreba vodonika u energetskim sektorima. Potencijal zamene fosilnih goriva održivo proizvedenim vodonikom odav-no je prepoznat. Zbog porasta troškova energije poslednjih godina, uticaja konvencionalnih goriva na životnu sredinu i postignutog/predviđenog tehnološkog napretka u skladištenju i transportu, vo-donik postaje sve više izvodljivo rešenje u smislu primarnog izvora energije. Evropske zemlje su postavile ambiciozne planove za koriš-ćenje vodonika kao obnovljivog izvora energije. Mnogi istraživački projekti finansirani su iz grantova EU, dok je Evropska komisija po-stavila u martu 2022. godine plan za što veću nezavisnost od uvo-za fosilnih goriva, koji između ostalog za cilj ima proizvodnju 10 miliona tona vodonika, dok je 10 miliona tona planirano za uvoz do 2030. godine.Korišćenje vodonika kao izvora goriva u sektoru vazduhoplov-stva se takođe dosta razmatra poslednjih godina. Prednosti vodonika kao avionskog goriva su očigledne. Vodonik je održiv, ne proizvodi emisije štetnih gasova, ima veliku gustinu energije itd. Međutim, još uvek postoje velike tehničke poteškoće koje bi trebalo prevazići, što predstavlja izazov pri postavljanju vodonika kao održivog goriva za vazduhoplovstvo. U radu su predstavljeni i diskutovani najznačajniji izazovi, neka moguća rešenja i mogućnosti koje proizilaze iz upotre-be vodonika za vazduhoplovne propulzore.Rad je izložen na 36. Mađunarodnom kongresu o procesnoj industriji, 1.-2. jun 2023. godine, Šabac i u celosti je štampan/objavljen u Zborniku radova kao i u časopisu Procesna tehnika God. 35 Br. 1 (2023

Suplementacija magnezijuma i status gvožđa kod studentkinja - studija intervencije

Abstract Background: Literature data indicate the benefit of magnesium (Mg) supplementation. The aim of this study was to examine the effect of short-term Mg supplementation on iron status in healthy female participants. Methods: One hundred healthy female students of the University of Belgrade - Faculty of Pharmacy participated the study during eleven intervention days. Students ingested Mg preparations with the same dose of the active substance. The analysis included the measurement of serum iron, unsaturated iron binding capacity (UIBC), total iron binding capacity (TIBC), total Mg (tMg), ionized Mg (iMg), complete blood count, met-, carboxy- and oxy-haemoglobin (metHgb, COHgb, O2Hgb). Transferrin concentrations and percentage of transferrin saturation (SAT) were calculated manually. The association among the analyzed biochemical parameters was examined using polynomial regression. A principal component analysis (PCA) was used for the evaluation of interdependence between the analyzed parameters. Results: A statistically significant trend for change in O2Hgb (%) by tertiles of iMg concentrations was found (P = 0.029). Serum tMg reached significant positive correlation with the SAT at concentration levels greater than 0.9 mmol/L, after 11 days of intervention (R2=0.116). Ionized Mg in a concentration higher than 0.6 mmol/L is positively correlated with SAT and serum Fe (R2=0.214; 0.199, respectively). PCA revealed variability of 64.7% for two axes after 11 days. Conclusions: Mg supplementation leads to an improvement in the certain iron status parameters even in individuals with optimal levels of these indices. However, caution should be exercised when supplementing Mg, and laboratory monitoring of the interaction is required.Uvod: Literaturni podaci ukazuju na benefit suplementacije magnezijumom (Mg). Cilj ove studije bio je da se ispita uticaj kratkotrajne suplementacije Mg na status gvožđa kod zdravih žena. Metode: Sto zdravih studentkinja Univerzitet u Beogradu - Farmaceutskog fakulteta je učestvovalo u istraživanju tokom jedanaest dana intervencije. Studenti su uzimali preparate Mg sa istom dozom aktivne supstance. U serumu je određivano gvožđe, nezasićen kapacitet vezivanja gvožđa (UIBC), ukupan kapacitet vezivanja gvožđa (TIBC), ukupan Mg (tMg), jonizovni Mg (iMg), kompletna krvna slika, met-, karboksiioksihemoglobin (metHgb, COHgb, O2Hgb). Transferin i saturacija transferina (SAT) su izračunati ručno. Povezanost analiziranih biohemijskih parametara je ispitana pomoću polinomalne regresije. Za procenu međuzavisnosti između analiziranih parametara korišćena je analiza glavnih komponenti (PCA). Rezultati: Utvrđen je statistički značajan trend promene O2Hgb (%) po tertilima koncentracija iMg (P = 0,029). Ukupan Mg je dostigao značajnu pozitivnu korelaciju sa SAT pri koncentracijama većim od 0,9 mmol/L, nakon 11 dana intervencije (R2 = 0,116). Jonizovani Mg u koncentraciji većoj od 0,6 mmol/L pozitivno korelira sa SAT i gvožđem (R2 = 0,214; 0,199, redom). PCA analizom je pokazana varijabilnost od 64,7% za dve ose nakon 11 dana. Zaključak: Suplementacija Mg dovodi do poboljšanja određenih parametara statusa gvožđa čak i kod pojedinaca sa optimalnim nivoima ovih parametara. Međutim treba biti oprezan pri suplementaciji Mg, a dodatno je neophodno i laboratorijsko praćenje ovih interakcija