Gamma Radiation Absorption Characteristics of Concrete with Components of Different Type Materials

Nuclear facilities as nuclear power stations, nuclear research reactors, particle accelerators and linear accelerator in medical institution using concrete in building construction. The different type materials of the aggregate as component of concrete were analyzed to provide radiation protection. The energy deposited the transmission factor and the mass attenuation coefficients in ordinary and barite concretes have been calculated with the photon transport Monte Carlo software. The numerical simulations results show that using barite as an aggregate in the concrete is one of the solutions for gamma ray shielding. Thereat, it is shown non-destructive method for determining the gamma radiation absorption characteristics of concrete.11th Annual Conference of the Materials-Research-Society-of-Serbia (YUCOMAT 2009), Aug 31-Sep 04, 2009, Herceg Novi, Montenegr

Determination of Recycled Aggregate Concrete Degradation By Resonance Frequency Analysis

The evaluation of the dynamic modulus of elasticity of twelve different concrete mix proportions as a function of the density and degradations due to freeze/thaw cycles is presented in this paper. Pore system and saturation are the main factors for concrete freeze-thaw resistance. The frequency analysis of ultrasonic waves in concrete after every 25 cycles was done. Dynamic modulus of elasticity was determination by resonance frequency analysis. This parameter is 35-50% smaller for concrete with recycled bricks as aggregate than ordinary concrete. For all concrete mixes dynamic and static (measured by destructive testing) modules of elasticity were compared

Determination of Recycled Aggregate Concrete Degradation By Resonance Frequency Analysis

The evaluation of the dynamic modulus of elasticity of twelve different concrete mix proportions as a function of the density and degradations due to freeze/thaw cycles is presented in this paper. Pore system and saturation are the main factors for concrete freeze-thaw resistance. The frequency analysis of ultrasonic waves in concrete after every 25 cycles was done. Dynamic modulus of elasticity was determination by resonance frequency analysis. This parameter is 35-50% smaller for concrete with recycled bricks as aggregate than ordinary concrete. For all concrete mixes dynamic and static (measured by destructive testing) modules of elasticity were compared

Intravenous drug use – an independent predictor for HCV genotypes 3 and 4 infection among HIV/HCV co-infected patients

Introduction : About one quarter of human immunodeficiency virus (HIV) infected persons in Serbia have also been found to be hepatitis C virus (HCV) co-infected. In the general population, HCV genotype 1 has been shown to be the most prevalent one. Here, we present the first study on the distribution of HCV genotypes among HIV/HCV co-infected patients in Serbia, in relation to epidemiological and clinical features. Material and methods : The study included HIV/HCV co-infected and a group of HCV mono-infected patients in the period 1998–2012, with collection of epidemiological, clinical, and behavioral data using a standardized questionnaire. The HCV genotyping to the level of pure genotype was performed by reverse hybridization. Results: Intravenous drug use (IDU) was found to be significantly more prevalent among the co-infected patients (p < 0.01). HCV genotype 1 was detected in 87% of patients with mono-infection, compared to 46.3% of patients with co-infection (p < 0.01); genotypes 3 and 4 were significantly more common among co-infected patients (6% and 5%, vs. 27% and 25%, respectively). Multivariate logistic regression confirmed IDU, infection with non-1 HCV genotype and HCV viral load over 5 log to be predictors of HIV co-infection. Conclusions : The HCV genotypes 3 and 4 were found to be significantly more prevalent among HIV/HCV co-infected patients in Serbia, compared to HCV mono-infected patients, but also more prevalent compared to the European HIV/HCV co-infected cohort. History of IDU represents an independent predictor of HCV genotypes 3 and 4 infection, with important implications for treatment

Molecular characterization and phylogenetic analysis of full-genome HBV subgenotype D3 sequences from Serbia

Hepatitis B virus (HBV) is classified into 8 genotypes with distinct geographical distribution. Genotype D (HBV/D) has the widest distribution area and is comprised of 7 subgenotypes. Subgenotypes D1, D2 and D3 appear worldwide, while D4-D7 have a more restricted distribution. Within the Mediterranean area, HBV/D and subgenotype D3 are the most prevalent. The purpose of this study was to characterize the full genome of Serbian HBV/D3 isolates by comparison and phylogenetic analysis with HBV/D3 sequences (66 samples) found in GeneBank/DDBJ databases from different parts of the world. Isolates were obtained from three patients diagnosed with chronic hepatitis B (HBsAg +). All three isolates have two very rare nucleotide substitutions, A929T and T150A, which indicate the same ancestor. Phylogenetic analysis of HBV/D3 genome sequences throughout the world follows an ethno-geographical origin of isolates with rare exceptions, which could be explained by human travelling and migration. The geographically close but ethnically different Serbian and Italian isolates clustered in the same subnode, and on a common branch with strains from Northern Canada. To test the apparently close HBV phylogenetic relationship between completely separated patients from Serbia and Northern Canada we analyzed in depth a 440 bp region of the HBsAg from Canadian (n = 73) and Serbian (n = 70) isolates. The constructed parsimony tree revealed that strains from Serbia and Northern Canada fell along the same branch which indicates independent evolution within regions of each country, Considering that HBsAg sequence has limited variability for phylogenetic analyses, our hypothesis needs further confirmation with more HBV complete genome sequences. (C) 2011 Elsevier B.V. All rights reserved

Translation and validation of the Serbian primary biliary cholangitis-40 questionnaire.

To translate into Serbian and validate the Primary Biliary Cholangitis-40 (PBC-40) and PBC-27 questionnaires.Ninety-four consecutive outpatients with the diagnosis of PBC from three departments across two tertiary care institutions in Belgrade were enrolled from February to October 2016. Standard methodology for cultural adaption of healthcare related quality of life questionnaires was used, and included: a forward translation, backward translation and a pilot test of the Serbian PBC-40 on five patients who gave suggestions and comments. For evaluation of the questionnaires, acceptance was shown by the proportion of missing items and the internal consistency was assessed using Cronbach's α coefficient. The PBC-40 was self-administered under the supervision of an experienced hepatologist. The PBC-27 is a shorter version of the PBC-40.A total of 92 (97.9%) of the patients were females. The mean age was 59.26 ± 1.05 years and the average length of disease was 60.45 ± 48.314 months. The average PBC-40 score was 85.62 ± 30.46. The total time needed to complete the questionnaire ranged from 7 to 16 minutes. The proportion of missing items was 5.45% (205/3760). Cronbach's α for the entire scale was 0.93. Reliability for all of the domains of the PBC-40 was above 0.70, except for the domain "Symptoms" (α = 0.52). Overall reliability of the PBC-27 was α = 0.90. Domains "Dryness", "Symptoms" and "Fatigue" demonstrated reliability below α = 0.70.The Serbian PBC-40 is a valid and reasonably adequate for use in Serbian PBC patients. The PBC-40 is preferred over the PBC-27

Serological status of childbearing-aged women for Toxoplasma gondii and cytomegalovirus in northern Kosovo and Metohija

Abstract INTRODUCTION: Toxoplasma gondii and cytomegalovirus (CMV) are pathogens associated with congenital anomalies. METHODS: Serum was collected from 79 reproductive-age women and tested for IgM and IgG antibodies to T. gondii and CMV. RESULTS: Seropositivity for T. gondii was detected in 24.1% of women and CMV in 96.2%. High seropositivity for CMV was found for all ages. The highest seropositivity for T. gondii was observed among older participants. CONCLUSIONS: T. gondii remains an important pathogen owing to low seropositivity