Catalitic effect of Co on hydrogen desorption form nanostucturated magnesium hydride

To study the influence of 3d transition metal addition on desorption kinetics of MgH2 ball milling of MgH2-Co blends was performed under Ar. Microstructural and morphological characterization, performed by XRD and SEM, show a huge correlation with thermal stability and hydrogen desorption properties investigated by DSC. A complex desorption behavior is correlated with the dispersion of the metal additive particles on hydride matrix. The activation energy for H-2 desorption from MgH2-Co composite was calculated from both non-isothermal and isothermal methods to be 130 kJ/mol which means that mutually diffusion and nucleation and growth of new phase control the dehydration process.6th Conference of Young Researchers, Dec 24-26, 2007, Belgrade, Serbi

FIVE-FACTOR MODEL PERSONALITY PROFILES: THE DIFFERENCES BETWEEN ALCOHOL AND OPIATE ADDICTION AMONG FEMALES

Background: The prevalence of female alcohol and substance abusers has markedly increased. The main objective of this research was to explore personality profiles among females who had alcohol and opiate dependence. Aim: The aim of the study is to analyse if there is differences in personality profiles of females addicted to alcohol and opiates. We hypothesized that there might be significant differences in personality profiles among subgroups of women who present with alcohol and opiate use disorders. Subjects and methods: Of 157 consecutive women with diagnosis of alcohol/opiate addiction, 62 fulfilled following inclusion criteria: age 19-45 years, abstinence from alcohol and opiates for at least 10 days prior to enrollment. Alcohol-dependent group consisted of 30 females, while opiate-dependent group consisted of 32 females. The control group involved 30 age-matched randomly chosen healthy women. The data were collected using the Revised NEO Personality Inventory (NEO-PI-R). The multiple stepwise discriminant analysis was used to determine relations between personality traits and the probability of belonging to one of the study groups. Results: Significant differences in the NEO-PI-R scores were observed between groups for all main personality traits except for Openness to Experience. Compared with controls, substance-dependent women scored significantly higher on Neuroticism and lower on Conscientiousness. Opiate-dependent females scored the highest on Neuroticism and on Extraversion and lowest on Agreeableness and on Conscientiousness. Alcohol-dependent females scored higher on Conscientiousness and lower on Neuroticism compared to opiate-dependent women. Conclusions: The results of our study confirmed significant characteristics in personality profiles among females with alcohol and opiate dependence, as well as the difference between these two groups of substance abusers and their healthy controls. The distinct personality characteristics among different groups of substance addicted women should be taken into account when creating the most effective program of prevention and therapeutic approaches in this specific cohort

QUALINET white paper on definitions of Immersive Media Experience (IMEx)

With the coming of age of virtual/augmented reality and interactive media, numerous definitions, frameworks, and models of immersion have emerged across different fields ranging from computer graphics to literary works. Immersion is oftentimes used interchangeably with presence as both concepts are closely related. However, there are noticeable interdisciplinary differences regarding definitions, scope, and constituents that are required to be addressed so that a coherent understanding of the concepts can be achieved. Such consensus is vital for paving the directionality of the future of immersive media experiences (IMEx) and all related matters. The aim of this white paper is to provide a survey of definitions of immersion and presence which leads to a definition of immersive media experience (IMEx). The Quality of Experience (QoE) for immersive media is described by establishing a relationship between the concepts of QoE and IMEx followed by application areas of immersive media experience. Influencing factors on immersive media experience are elaborated as well as the assessment of immersive media experience. Finally, standardization activities related to IMEx are highlighted and the white paper is concluded with an outlook related to future developments

Population pharmacokinetic of antiepileptic drugs in different populations

This article reviews a population pharmacokinetics studies conducted during the past few years in Serbia. Studies have included three the most frequently used antiepileptic drugs (valproate, carbamazepine and lamotrigine) and different populations of epileptic patients: children, adults and heterogeneous population composed of both children and adults. The review compares obtained values of population pharmacokinetic models of clearance of these drugs, and factors that are significantly determined, making brief comments on the results of other authors on the same topic. Individualization of drug dosage is the basis of rational therapy, and factors of variability will always be subject of scientific research. © 2013 Versita Warsaw and Springer-Verlag Berlin Heidelberg

Socioeconomic significance and prevention of early childhood caries

© 2014 Faculty of Medicine in Niš. Early childhood caries is considered to be the most common infectious and chronic pediatric disease, which is defined as the presence of tooth decay that implies any primary tooth in a child six years of age or younger and develops through a complex process that involves the transmission of infectious bacteria, dietary habits and oral hygiene. It often occurs as a result of prolonged breastfeeding and frequent consumption of sugar-containing beverages in a baby bottle. Nowadays, it is considered one of the topical public health issues in developing countries, as well as developed countries around the world, due to its high prevalence. The results of many studies indicate that there are leading risk factors common to all regions, such as socioeconomic, cultural and factors related to hygiene and dietary habits. However, the greatest single risk factor is poverty. This disease is often followed by complications, such as chronic pulpitis and apical periodontitis, and can cause severe pain that disturbs children's daily activities, eating, sleeping, and affects growth and development. It requires extensive and expensive dental treatments which sometimes need to be performed under general anesthesia, and the final results are still unsatisfactory. However, significant results can be achieved by the introduction, evaluation and implementation of prevention programs and strategic measures. The role of the state and the community is very important in making decisions on directing their resources to prevention, as the most cost-effective measure, as well as in increasing public awareness of the importance of oral health as part of general health. The role of professionals prior to medical treatment and also parents at family level in providing the knowledge, skills and oral hygiene habits with their children is a necessary measure aimed at preserving the health of the entire population

CYP3A5 polymorphism in serbian paediatric epileptic patients on carbamazepine treatment

© 2015 University of Kragujevac, Faculty of Science. All rights reserved. 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. Geno-typing 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

The influence of CYP2C8∗3 on carbamazepine serum concentration in epileptic pediatric patients

© 2016 Walter de Gruyter GmbH, Berlin/Boston. The aim of the present study was to investigate the distribution of CYP2C8 variants ∗3 and ∗5, as well as their effect on carbamazepine pharmacokinetic properties, in 40 epileptic pediatric patients on carbamazepine treatment. Genotyping was conducted using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and allele-specific (AS)-PCR methods, and steady-state carbamazepine plasma concentrations were determined by high performance liquid chromatography (HPLC). The CYP2C8 ∗3 and ∗5 polymorphisms were found at frequencies of 17.5 and 0.0%, respectively. After dose adjustment, there was a difference in daily dose in CYP2C8∗3 carriers compared to non carriers [mean ± standard deviation (SD): 14.19 ± 5.39 vs. 15.46 ± 4.35 mg/kg; p = 0.5]. Dose-normalized serum concentration of carbamazepine was higher in CYP2C8∗3 (mean ± SD: 0.54 ± 0.18 vs. 0.43 ± 0.11 mg/mL, p = 0.04), and the observed correlation between weight-adjusted carbamazepine dose and carbamazepine concentration after dose adjustment was significant only in CYP2C8∗3 non carriers (r = 0.52, p = 0.002). However, the population pharmacokinetic analysis failed to demonstrate any significant effect of CYP2C8 ∗3 polymorphism on carbamazepine clearance [CL L/h = 0.215 + 0.0696∗SEX+ 0.000183∗DD]. The results indicated that the CYP2C8∗3 polymorphism might not be of clinical importance for epilepsy treatment in pediatric populations

CYP3A5 Polymorphism In Serbian Paediatric Epileptic Patients On Carbamazepine Treatment

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

Population pharmacokinetics of vancomycin in adult patients with long bones’ fractures

Vancomycin is a tricyclic glycopeptide antibiotic, mostly used in the treatment of severe staphylococcal and enterococcal infections, especially in orthopedic surgery. The purpose of this analysis was to develop a population pharmacokinetic (PPK) model of vancomycine in hospitalized patients with bone fractures and identify important factors which influence its clearance (CL). A total of ninety-nine measurements of vancomycin serum concentrations were used in our population modeling. A two-compartment model was applied to describe the pharmacokinetics of vancomycin using subroutines ADVAN3 and TRANS4. The study population included patients of both sexes, with the mean age of 62.12±14.69 years and body weight of 80.32±12.44kg. Vancomycin was administered as intravenous infusion with average daily dose of 1772.73±521.34mg. Out of twenty different factors evaluated in the study (including demo-graphic, clinical and laboratory data), only daily dose of vancomycin (DD) and co-medication with piperacillin/tazobactam (PT) showed significant effect on clearance of vancomycin. The final model was described by the following equation: CL (l/h) = 0.03 + 0.000468 x DD + 0.675 x PT. Bootstrapping was used for validation of the final model. In conclusion, the main causes of variability in the clearance of vancomycin among adult patients with bone fractures are daily dose of vancomycin and co-medication with piperacillin/tazobactam

Pharmacokinetics of vancomycin in patients with different renal function levels

There are many determinants of vancomycin clearance, but these have not been analyzed separately in populations with different levels of renal function, which could be why some important factors have been missed. The aim of our study was to compare the pharmacokinetic parameters and factors that may affect vancomycin pharmacokinetics in groups of patients with normal renal function and in those with chronic kidney failure. The study used a population pharmacokinetic modeling approach, based on plasma vancomycin concentrations and other data from 78 patients with chronic kidney failure and 32 patients with normal renal function. The model was developed using NONMEM software and validated by bootstrapping. The final model for patients with impaired kidney function was described by the following equation: CL (L/h) = 0.284 + 0.000596 x DD + 0.00194 x AST, and that for the patients with normal kidney function by: CL (L/h) = 0.0727 + 0.205 x FIB. If our results are confirmed by new studies on two similar populations, these factors could be considered when dosing vancomycin in patients with chronically damaged kidneys, as well as in patients with normal kidneys who frequently require high doses of vancomycin