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  • Author: Dragan Djordjevic x
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Dragan Djordjevic, Dragan Stojiljkovic and Miodrag Smelcerovic

Abstract

In order to investigate the mechanism of adsorption of reactive dyes from the textile industry on ash from heating plant produced by brown coal combustion, some characteristic sorption constants are determined using Langergren adsorption equations for pseudo-fi rst and pseudo-second order. Combined kinetic models of pseudo-first order and pseudo-second order can provide a simple but satisfactory explanation of the adsorption process for a reactive dye. According to the characteristic diagrams and results of adsorption kinetic parameters of reactive dyes on ashes, for the applied amounts of the adsorbents and different initial dye concentrations, it can be concluded that the rate of sorption is fully functionally described by second order adsorption model. According to the results, the rate constant of pseudo-second order decreases with increasing initial dye concentration and increases with increasing amount of adsorbent – ash.

Open access

Ivana Mitrovic Djordjevic and Dragan Vasiljevic

Abstract

The goal of this paper is to determine the level of patient satisfaction with health care among adults in the Republic of Serbia and to analyze the correlation between the satisfaction and socio-demographic characteristics of the interviewees. The paper is based on the data provided by the National health survey of the Republic of Serbia. For the purposes of this paper, we used data on age and household of the people aged 19 and more. By eliminating the interviewees who were neither satisfied nor dissatisfied with the health care services, we obtained the sample containing 18.206 interviewees. Demographic characteristics and well-being index represented independent variables in the research. Dependent variable of the patient satisfaction was transformed into a binary variable by categorizing satisfied and very satisfied interviewees into one group and by placing dissatisfied and very dissatisfied interviewees into group of dissatisfied patients. The connection between satisfaction and predictors was examined using Chi-Square test and logistic regression. The percentage of the satisfied patients with health care was 72.9%. The satisfaction level was directly connected to age, gender, marital status, employment, region the interviewee comes from and well-being index. Patients who were more satisfied included older people, women, as well as married people, the unemployed and those living in the cities. The analysis of the financial situation shows that the poorest interviewees were the most satisfied with health care.

Open access

Dijana Mosić and Dragan S. Djordjević

Abstract

We investigate some necessary and sufficient conditions for the reverse order law for the weighted Moore-Penrose inverse in rings with involution.

Open access

Gordana Djordjevic, Snezana Radovanovic, Nela Djonovic, Svetlana Radevic, Dragan Vasiljevic and Natasa Mihailovic

Abstract

The aim of the work is to assess vulnerability degree of reproductive health in adolescent population in Serbia by analyzing their sexual behavior. The paper is based on data from a National health survey of the population in Serbia in 2013 (without Kosovo and Metohija region), conducted by the Ministry of Health of the Republic of Serbia. For the purposes of this study, the data used are referred to households and population of age 15 and over, so that the final number for analysis is a sample of 1722 respondents aged 15 -24. The study included demographic characteristics of respondents (age, gender, settlement type, region) and the characteristics of reproductive health: sexual behavior, use of contraceptive protection, knowledge and attitudes towards HIV, protection of reproductive health. χ2 test was applied for testing diff erences in frequency of categorical variables. All results with a probability that equals to or is less than 5% (p≤0.05) are considered statistically significant. Among the respondents, there were more than half (53.5%) of sexually active adolescents. The highest percentage of them- 16.6% responded that they had first sexual intercourse at the age of 17. 53.4% of adolescents had sexual intercourse with one partner, 26.4% of respondents had sexual intercourse with two or more partners. The most commonly used contraceptive method was interrupted intercourse (coitus interruptus) with 34.7% of respondents.

Open access

Milena N. Miljkovic, Dragan M. Djordjevic, Vojkan M. Miljkovic, Miodrag Stamenkovic and Jovan Stepanovic

Abstract

The influence of using formic, oxalic, citric, tartaric, hydrochloric, nitric, sulphuric and phosphoric acid for dyebath pH adjustment was investigated upon the dyeing of polyester fabric with CI Disperse Yellow 60. The positions of colour in CIELab coordinates of the samples dyed with the addition of tested acids were assessed and compared to those dyed with the addition of acetic acid. It was found that the differences in dyeabilities obtained with the addition of citric, oxalic, hydrochloric, nitric and sulphuric acid are entirely acceptable according to both M&S 83A and CMC (2:1) standards in comparison to the dyeability obtained with the addition of acetic acid.

Open access

Ivana Simic Vukomanovic, Sanja Kocic, Svetlana Radevic, Snezana Radovanovic, Dragan Vasiljevic, Vladimir Djordjevic and Slavica Djukic Dejanovic

Abstract

Abuse in younger populations has been an issue of growing concern globally since youth already face various life situations that can heighten the occurrence of depression and anxiety disorders. The aim of this study was to determine the prevalence of physical and psychological abuse and its correlation with depressive and anxiety symptoms among students.

This research was conducted as an epidemiological study of a sample of 1,940 university students using a standardized questionnaire by the World Health Organization. The survey, in addition to questions related to the abuse of youth, also included the Beck Depression Inventory and Beck Anxiety Inventory.

Based on the results of this study, psychological abuse had a prevalence of 17.1%, while the prevalence of physical abuse was approximately 1.8%. Depressive symptoms were significantly related to physical (p<0.001) and psychological abuse (p<0.005), and anxiety symptoms were also significantly related to both physical (p=0.003) and psychological abuse (p<0.005).

The results of this study indicated the importance of the early detection of abuse and depressive and anxiety symptoms among university students, which is essential for mental health promotion and the prevention of mental disorders.

Open access

Dragana Djordjevic, Jelena Milovanovic, Milena Jurisevic, Bojana Stojanovic, Olga Cvetkovic, Marija Pergal, Elizabeta Ristic, Danilo Vojvodic, Milos Simic, Dragan Manojlovic, Marija Milovanovic and Nebojsa Arsenijevic

Abstract

Copper serves as a limiting factor for multiple steps of tumour progression, including angiogenesis, growth and metastasis. High levels of copper have been found in a wide spectrum of human cancers. Antitumour activities of copper-chelating drugs have been reported in animal models. Organosulfur compounds (diallyl sulfi de, DAS; diallyl disulfi de, DADS; S-ethylcysteine, SEC; N-acetylcysteine, NAC) derived from garlic exhibit marked copper- chelating activity. We analysed a mixture of fi fteen n-propyl polysulfi des (DPPS) for potential antitumour activity against several murine tumour cell lines, including colon carcinoma (CT26), mammary carcinoma (4T1) and melanoma cell lines (B16F10), and compared the eff ects with the antiproliferative eff ect in highly proliferative murine mesenchymal stem cells (mMSCs). Th e eff ects of the mixture of n-propyl polysulfi des (100%) on cell viability were determined using MTT assays. Cell apoptosis was analysed using Annexin V-FITC/PI assays. Th e results of the MTT assays indicate that this standardized mixture of n-propyl polysulfi des has a strong, dose-dependent cytotoxic eff ect against all three of the tested tumour cell lines (CT26, 4T1, B16F10). Th e cytotoxic eff ect of the n-propyl polysulfi de mixture against the CT26 and B16F10 cell lines was much stronger than that of cisplatin and was signifi cantly weaker in mMSCs, which are non-cancerous and highly proliferative cells, than in cancer cells. Flow cytometric analysis of CT26 and 4T1 cells revealed that apoptosis was not the dominant mechanism of cell death induced by the n-propyl polysulfi de mixture. Th e n-propyl polysulfi de mixture exerted highly cytotoxic activity against murine colon carcinoma and melanoma cell lines, but its antiproliferative activity against mMSCs was signifi cantly lower than that of cisplatin.

Open access

Dragan Djordjevic, Janko Pejovic, Maja Surbatovic, Jasna Jevdjic, Sonja Radakovic, Milic Veljovic, Aneta Peric, Tamara Andjelic and Nada Popovic

Summary

Background: Severe sepsis and/or trauma complicated by multiple organ dysfunction syndrome are the leading causes of death in critically ill patients. The aim of this prospective single-centre study was to assess the prognostic value and daily trend of interleukin-6 (IL-6), neutrophil CD64 expression, C-reactive protein (CRP) and lipopolysaccharide-binding protein (LBP) regarding outcome in critically ill patients with severe trauma and/or severe sepsis. Outcome measure was hospital mortality.

Methods: One hundred and two critically ill patients admitted to the intensive care unit of a tertiary university hospital were enrolled in this prospective study. Blood samples were collected on admission (day 1), days 2 and 3.

Results: CD64 index was 1.6-fold higher on day 1 and 1.78-fold higher on day 2 in non-survivors (p<0.05). The area under the curve (AUC) for the CD64 index on day 1 for outcome was 0.727. At a cut-off level of 2.80 sensitivity was 75% and specificity was 65%. Patients with CD64 index level on day 1 higher than 2.80 had 2.4-fold higher probability of dying. Odds ratio is 2.40; 95% CI 0.60–9.67.

Conclusions: CD64 index on day 1 is a fairly good predictor of outcome. AUCs for IL-6, CRP and LBP were < 0.55, suggesting these biomarkers failed to predict outcome.

Open access

Dragana Dragas Milovanovic, Ivan Radosavljevic, Marija Radovanovic, Jasmina R. Milovanovic, Slobodan Obradovic, Slobodan Jankovic, Dragan Milovanovic and Natasa Djordjevic

Abstract

Carbamazepine exhibits significant inter-individual variability in its efficacy and safety, which leads to unpredictable therapy outcomes for the majority of patients. Although its complex biotransformation depends on CYP3A5 activity, evidence of association between carbamazepine treatment outcomes and CYP3A5 functional variations remains inconclusive. The aim of the present study was to investigate the distribution of two of the functionally important CYP3A5 variants *2 and *3 as well as their effects on carbamazepine dose requirements, plasma concentrations and clearance in a Serbian population. The study involved 40 paediatric epileptic patients on steady-state carbamazepine treatment. Genotyping was conducted using the PCR-RFLP method, and carbamazepine plasma concentrations were determined using the HPLC method. CYP3A5*2 and *3 polymorphisms were found at frequencies of 0.0% and 97.5%, respectively, which corresponds well to previously published data for Caucasians. No differences in CYP3A5*3 allele frequencies were detected among epileptic patients in comparison to healthy volunteers within similar ethnic populations (p>0.08), indicating that CYP3A5 polymorphism does not represent a risk factor for epilepsy development. There was an observed tendency towards lower dosage requirements (mean±SD: 15.06±4.45 mg/kg vs. 18.74±5.55 mg/kg; p=0.26), higher plasma concentrations (mean±SD: 0.45±0.13 mg/kg vs. 0.38±0.03 mg/kg; p=0.47) and lower clearance (mean±SD: 0.14±0.05 mg/kg vs. 0.15±0.01 mg/kg; p=0.79) of carbamazepine in homozygous carriers of CYP3A5*3/*3 compared to heterozygous CYP3A5*1A/*3 Serbians. Because these genotype groups did not differ significantly in terms of their carbamazepine pharmacokinetics parameters, the proposed effects of CYP3A5*3 on carbamazepine metabolism could not be confirmed.