Survey of Slaughtered Pigs for Occurrence of Ochratoxin A and Porcine Nephropathy in Serbia

Samples of blood, kidney and liver were randomly selected from slaughtered pigs (n=90) and analyzed for ochratoxin A by HPLC. In addition, in order to obtain information on the occurrence of nephropathy, histological examinations were carried out. Of the 90 liver samples, 26.6% contained OTA in the range of 0.22–14.5 ng/g. The incidence of OTA in serum and kidney were very similar (31%, 33.3%), with a maximum concentration of 220.8 ng/mL, and 52.5 ng/g, respectively. Histopathological examination of kidneys confirmed tubulopathies with edema and cell vacuolization. In addition, hemorrhages and necrosis of proximal kidney tubules’ cells were found

The influence of selenium and deiodinases blockers on juvenile rats body weight

In this work there was investigated the influence of selenium and deodinases blockers on juvenile rats body weight during three months. The experiment was carried out on 64 rats divided into eight groups with eight individual animals per group. Following groups were formed: 1. Se+PTU-IA- (control group), 2. Se+PTU+IA+, 3. Se+PTU+IA-, 4. Se+PTU- IA+, 5. Se-PTU-IA-, 6. Se-PTU+IA+, 7. Se-PTU+IA- and 8. Se-PTU-IA+. The groups labeled (Se+) were selenium adequate and they were fed with food that contained 0.334 mg Se/kg. The groups labeled (Se-) were selenium deficient and obtained food with 0.031 mg Se/kg. As deiodinases blockers there were used propylthiouracil (PTU+) in a dose of 150 mg/L of drinking water and iopanoic acid (IA+) in a dose of 6 mg/100 g TM intraperitoneally. Body weight of experimental rats was measured every seven days. After three weeks of treatment there were taken blood samples of animals from all experimental groups and following parameters were determined: selenium concentration in blood, thyroxine (T4), triiodothyronine (T3) and thyroidstimulating hormone (TSH) in blood plasma. Analysis of the samples showed that the animals from the groups treated with PTU had lower body weight in regard to the control group, as well as lower concentration of T3 and T4 in plasma. Selenium deficient rats had lower average body weight compared to the selenium adequate ones after three weeks, but there were no differences in thyroid hormones concentration. The lowest average body weight was noticed in selenium deficient rats groups treated with PTU. [Projekat Ministartsva nauke Republike Srbije, br. TR31050 i br. TR31003

Analysis of the Dynamic Response as a Basis for the Efficient Protection of Large Structure Health Using Controllable Frequency-Controlled Drives

Continuous earthmoving machines, such as bucket-wheel excavators (BWEs), are the largest mobile terrestrial machines exposed to the working loads of a periodic character. This paper aims to launch a new idea regarding the preservation of the load-carrying structures of these machines by the means of implementing a controllable frequency-controlled drive of the excavating device. Successful implementation of this idea requires a detailed analysis of the dynamic response of the load-carrying structure in order to determine the domains of frequency of revolutions of the bucket-wheel-drive electromotor (FREM) where the dynamic response of the structure is favorable. The main goal of the presented research was the development of a unique three-step method for the identification of the FREM ranges, where the vibroactivity of the load-carrying structure is within the allowed boundaries. A methodologically original study of the dynamic response was conducted on a unique dynamic model of the BWE slewing superstructure that allows for continuous variation of the FREM, i.e., of the frequency of excitation caused by the forces resisting the excavation. Validation of the spatial reduced dynamic model of the slewing superstructure and the corresponding mathematical model, as well as the overall approach to the determination of the dynamic response, were performed by the means of vibrodiagnostics under the real exploitation conditions. Application of the developed method has yielded: (1) the resonant-free FREM domains; (2) the FREM domains, where the structure is not exposed to the excessive dynamic impacts; and (3) the frequency ratio ranges defining the resonant areas. Additionally, the results of the research have pointed out that the resonant-free state represents a necessary but insufficient condition for the proper dynamic behavior of the BWE slewing superstructure

Analysis of the Dynamic Response as a Basis for the Efficient Protection of Large Structure Health Using Controllable Frequency-Controlled Drives

Continuous earthmoving machines, such as bucket-wheel excavators (BWEs), are the largest mobile terrestrial machines exposed to the working loads of a periodic character. This paper aims to launch a new idea regarding the preservation of the load-carrying structures of these machines by the means of implementing a controllable frequency-controlled drive of the excavating device. Successful implementation of this idea requires a detailed analysis of the dynamic response of the load-carrying structure in order to determine the domains of frequency of revolutions of the bucket-wheel-drive electromotor (FREM) where the dynamic response of the structure is favorable. The main goal of the presented research was the development of a unique three-step method for the identification of the FREM ranges, where the vibroactivity of the load-carrying structure is within the allowed boundaries. A methodologically original study of the dynamic response was conducted on a unique dynamic model of the BWE slewing superstructure that allows for continuous variation of the FREM, i.e., of the frequency of excitation caused by the forces resisting the excavation. Validation of the spatial reduced dynamic model of the slewing superstructure and the corresponding mathematical model, as well as the overall approach to the determination of the dynamic response, were performed by the means of vibrodiagnostics under the real exploitation conditions. Application of the developed method has yielded: (1) the resonant-free FREM domains; (2) the FREM domains, where the structure is not exposed to the excessive dynamic impacts; and (3) the frequency ratio ranges defining the resonant areas. Additionally, the results of the research have pointed out that the resonant-free state represents a necessary but insufficient condition for the proper dynamic behavior of the BWE slewing superstructure

Assessment of basic life support skills among medical doctors and technicians in Belgrade emergency medical services

Objective. Our aim was to assess BLS (basic life support) skills among medical doctors (MDs) and medical technicians (MTs) who work at Belgrade Emergency Medical Services (BEMS). Methods. A prospective study was conducted between 28 September and 9 December, 2016. MDs (Group 1) and MTs (Group 2) attended an accredited course in BLS at BEMS. At the end of the course the participants were given a written test consisting of 20 questions (pass rate 65%). Te results were analyzed for each group i.e. profession (Group 1 and Group 2) according to the number of accurate and inaccurate answers to each question. In the end, a number of participants from each group, who answered all 20 questions correctly, were identifed. Te results obtained, by test analysis, demonstrated the participants’ acquired BLS skills. Results. Te study involved 100 participants (50 in each group). All participants from Group 1 correctly answered questions number 1, 2, 3, 10, 13, 17 and 20. In Group 1 only two participants had three incorrect answers in the test. Te largest number of incorrect answers was related to question number 16. Tirty-four participants in this group answered all questions correctly. All participants from Group 2 gave correct answers to questions number 2, 5, 9, 10 and 13. In Group 2, one participant had six incorrect answers and one participant had 5 incorrect answers. Te largest number of incorrect answers was related to questions number 3 and 20. Nineteen participants from Group 2 answered all questions correctly. Te rate of correct answers between Group 1 and Group 2 was 19.66 : 18.91 (0.75 diference). Conclusion. Te research showed a satisfactory level of knowledge in both groups. However, there is a statistically signifcant diference in the knowledge of MDs afer the BLS course. Te results obtained justify the ambitions that all healthcare professionals, regardless of their qualifcations, should be trained in applying BLS, both at work and as eyewitnesses

UPLC-MS/MS determination of histamine levels in canned fish collected from Belgrade retail markets

The aim of this study was to determine the amount of histamine in canned fish samples collected from Belgrade retail stores using ultra-performance liquid chromatography tandem mass-spectrometry. In addition, the established levels were compared with the maximum levels set by US Food and Drug Administration (FDA) and European Union (EU) in order to assess the risk of this toxic biogenic amine to the city population. Histamine was detected in 54.07% of analyzed canned fish, in concentrations ranging from 5 to 420 mg/kg with a mean level of 60.91 mg/kg. In canned tuna, histamine levels ranged from 6 to 420 mg/kg, while in canned mackerel the concentrations ranged from 5 to 121 mg/kg. Also, the mean histamine level in canned tuna was higher than in canned mackerel (mean values were 60.91 mg/kg and 42.94 mg/kg, respectively). Among the tested canned fish, 20% of samples had higher histamine levels than the maximum level prescribed by the FDA (histamine levels >50 mg/kg), indicating definite decomposition of the fish. Histamine levels lower than 10 mg/kg were found in 51.48% of canned fish, which indicated good-quality fish products. Only 6.67% of examined production lots of canned fish had histamine levels above the regulatory limit according to the EU standard

Da li polifenoli mogu da se koriste kao prirodni konzervansi u fermentisanim kobasicama?

This study was aimed at the investigation into the influence of polyphenols on fermented sausages produced with and without nitrite addition, during storage which lasted for 280 days. Three types of sausages were produced and formed the three experimental groups: C-the control-sausages of usual composition containing nitrites; N+P-sausages with nitrites and polyphenols; and P-nitrite-free sausages with added polyphenols. The proximate chemical composition of all groups was in the range with that of dry fermented sausages. P sausages contained 0.3 mg nitrites per kg, while C and N+P contained 54.8 mg/kg and 52.2 mg/kg, respectively. Polyphenol-enriched sausages had significantly lower peroxide and TBARS values than C sausages. In all sausages lactic acid bacteria counts reached 8.9-9.9 log cfu/g, but decreased during storage to 4.3-4.8 log cfu/g at the end of the storage period. Micrococcaceae counts remained stable: 3.5-3.9 log cfu/g. In P and N+P sausages a significantly lower number of Pseudomonadaceae was observed than in the control. The lightness of C and P sausages was similar (L=50.2 and L=49.5, respectively), while N+P sausages were darker (L=42.5). C and N+P sausages had similar redness (a∗=14.5 and a∗=13.2, respectively) and yellowness (b∗=5.9 and b∗=6.4, respectively), but the values which correspond to redness and yellowness were lower in P sausages (a∗=8.0 and b∗=4.6). Sensory characteristics of all products were found to be very similar. The flavour of polyphenol-enriched sausages was considered to be better. The most dominant polyphenol in sausages was kaempferol-3-O-glucoside followed by quercetin, luteolin-7-O-glucoside, catechin and syringic acid. Nitrite-free polyphenol-enriched sausages reached the same shelf life as conventional sausages containing nitrites did, which is a promising result implying that polyphenols might be used as natural preservatives and nitrite substitutes. Simultaneous use of nitrite and polyphenols is questionable due to their interactions which should be further studied.Cilj ovog rada bio je ispitivanje uticaja polifenola na fermentisane kobasice proizvedene sa ili bez dodatka nitrita za vreme skladištenja od 280 dana. Proizvedena su tri tipa kobasica, od kojih su formirane tri eksperimentalne grupe: C - kontrolna grupa – kobasice uobičajenog sastava koje sadrže nitrite, N+P - kobasice sa nitritima i polifenolima i P - kobasice bez nitrita koje sadrže polifenole. Hemijski sastav svih grupa kobasica bio je u opsegu uobičajenom za fermentisane suve kobasice. P kobasice sadržale su 0,3 mg/kg nitrita, dok su C i N+P sadržale 54,8 mg/kg, odnosno 52,2 mg/kg. Kobasice obogaćene polifenolima imale su značajno manji peroksidni i TBARS broj nego C kobasice. Broj mlečno-kiselinskih bakterija dostigao je 8,9-9,9 log cfu/g, ali je u toku skladištenja opao na 4,3-4,8 log cfu/g posle 280dana u svim grupama kobasica. Broj Micrococcaceae bio je konstantan (3,5-3,9 log cfu/g). Kod P i N+P kobasica utvrđen je značajno niži broj Pseudomonadaceae. C i P kobasice bile su približno jednako svetle (L=50,2,odnosnoL=49,5) dok su N+P kobasice bile tamnije (L=42,5). C i N+P kobasice imale su sličan intenzitet crvne (a*=14,5 odnosno a*=13,2) i žute boje (b*=5,9 odnosno b*=6,4) ali su ove vrednosti bile niže kod P kobasica (a*=8,0 i b*=4,6). Senzorske karakteristike svih proizvoda bile su približno jednako ocenjene. Nešto bolja aroma utvrđena je od kobasica kojima su dodati polifenoli. Najdominantniji polifenol u kobasicama bio je kempferol-3-O-glukozid, a pored njega, bili su utvrđeni kvercetin, luteolin-7-O-glukozid, katehin i siringinska kiselina. Kobasice bez nitrita obogaćene polifenolima postigle su istu održivost kao i uobičajene kobasice koje sadrže nitrite, što predstavlja ohrabrujuće rezultate za mogućnost upotrebe polifenola kao prirodnog konzervansa i zamene za nitrite. Simultana upotreba nitrita i polifenola nije pouzdana zbog interakcija između polifenola i nitrita, što bi trebalo da bude detaljnije istraženo u budućnosti

Comparison of two analytical methods (ELISA and LC-MS/MS) for determination of aflatoxin B-1 in corn and aflatoxin M-1 in milk

The aim of this paper is to assess the closeness of agreement between results of ELISA and LC-MS/MS methods for determination of aflatoxin B-1 in corn and aflatoxin M-1 in milk. Samples of corn (n=100) and milk (n=250) were simultaneously analyzed using ELISA and LC-MS/MS methods, after the severe drought that affected Serbia in summer 2012 resulting in occurrence of aflatoxin B1 in corn and aflatoxin M-1 in milk. Regression analysis showed higher level of agreement between aflatoxin B-1 samples (R2=0.994), compared to aflatoxin M-1 samples (r(2)=0.920). However, both techniques were satisfactory in meeting the requirements for official control purposes

Sex expression in Serbian dendroflora: A case study of Fraxinus ornus var. angustifolia

Out of a total number of tree species in Serbian flora, 28% are hermaphrodites, 43% are monoecious and 29% are dioecious. The dendroflora appears to have a larger proportion of unisexual than hermaphrodite species. The monoecious system is the dominant unisexual system within the tree species in Serbia. The possible sex differentiation by RAPD markers and Correspondence Analysis was examined in a population of Fraxinus ornus var. angustifolia. On the basis of 6 selected RAPD bands which contribute to the differentiation in frequency between male and hermaphrodite individuals, Correspondence Analysis visualized the following tendency: 20 trees of each variety were separated into two groups that mainly correspond to sexual types. Our results showed that RAPD markers assisted by Correspondence Analysis could be used in identifying male and hermaphrodite individuals in F. ornus varieties.Projekat ministarstva br. P17301

Temporary Leaning of the Gas Oil Storage Tank Structure During Bottom Sanation

The design concept of temporary leaning of the gas oil storage tank bearing structure used during substitution of the worn out section of the bottom plates in the zone of the central column support is presented in the paper. On the basis of comparative analysis of the results obtained using finite element structural calculations of the designed state and the state of the central column leaning on the temporary supports, it was determined that by the implementation of the temporary support, the stress-strain state of the bearing structure, which corresponds to the designed stress-strain state of the construction, is obtained. Besides, the strength proof of the structure of temporary support including its welded joint to the central column is also presented in the paper