31 research outputs found

    Kvalitet vode u reci Raškoj na osnovu organizama zoobentosa i zooplanktona kao bioindikatora

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    U cilju ispitivnja kvaliteta vode reke Raške, organizmi zoobentosa i zooplanktona korišćeni su kao bioindikatori. Istraživanje je sprovedeno od aprila 2011. godine do maja 2012. godine, u vremenskim intervalima od dva meseca. Odabrano je ukupno pet lokaliteta na dužinini toka od 2.5 km. Između drugog i trećeg lokaliteta lociran je pastrmski ribnjak, čiji je uticaj na zajednice organizama praćen. Na lokalitetima koji su obuhvaćeni istraživanjima konstatovano je 57 taksona makrozoobentosa (34 vrste, 21 roda, 1 familija i 1 klasa) i 75 taksona zooplanktona (58 vrsta, 15 rodova, 1 red i 1 klasa). Srednje vrednosti indeksa saprobnosti ukazivale su na manje razlike u dobijenim vrednostima korišćenjem zoobentosa i zooplanktona. Na osnovu saprobioloških analiza, kada su kao bioindikatori korišćeni organizmi bentosa, kvalitet vode u reci Raškoj je druge klase kvaliteta, ili na prelazu između prve i druge klase, uglavnom na lokalitetima iznad ribnjaka. Organizmi zooplanktona su pokazali da voda celom dužinom toka pripada prvoj klasi kvaliteta. Najmanje vrednosti indeksa saprobnosti zabeležene su na prvom, referentnom lokalitetu 1.453±0.098 (zooplankton), a najviše na četvrtom lokalitetu 1.88±0.021 (zoobentos). Na lokalitetu ispod ribnjka, gde je zabeležen pad u koncentraciji kiseonika, dominiraju organizmi bentosa koji tolerišu veći stepen organskog zagađenja (Chironomidae, Oligochaeta, Simuliidae). Iako su koncentracije ukupnog fosfora i ortofosfata rasle od trećeg ka petom lokalitetu, njihove koncentracije nisu premašivale dozvoljene vrednosti za salmonidne vode. Međutim, srednje vrednosti koncentracije nejonizovanog amonijaka (NH4+) su iznad referentnih vrednosti na trećem i četvrtom lokalitetu. Razlog nepodudaranja vrednosti indekasa saprobnosti za dve istraživane grupe, može biti usled nestabilnih zooplanktonskih zajednica zbog izraženog efekta drifta, kao i usled činjenice da će zbog procesa sedimentacije dospelih organskih materija, organizmi dna biti izloženiji njihovom uticaju. Zajednice bentosa, kao znatno stabilnije i u vremenu i u prostoru, pogodnije su za procenu kvaliteta tekućih voda

    Sezonska varijabilnost i diverzitet cladocera (crustacea) u lagunama za prirodno prečišćavanje otpadnih voda iz domaćinstava

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    Cladocera predstavljaju najznačajniju komponentu zajednice zooplanktona u većini stajaćih slatkovodnih ekosistema. Kao filtratori, hrane se algama, bakterijama, protozoama i organskim česticama, koje obiluju u netretiranim otpadnim vodama iz domaćinstava. Krupne Cladocera se proteklih decenija uveliko primenjuju u biomanipulaciji kao biološko sredstvo za prečišćavanje organski opterećenih otpadnih voda i smanjenje primarne produkcije u vodenim ekosistemima. Istraživanje predstavljeno u ovom radu realizovano je na istraživačkom poligonu “Mali Dunav” Centra za ribarstvo i primenjenu hidrobiologiju, Poljoprivrednog fakulteta Univerziteta u Beogradu. U tri lagune, namenski napravljene na potoku Šugavac za prirodno prečišćavanje kanalizacionih voda poreklom iz uzvodno lociranog naselja, obavljeno je ispitivanje sastava i brojnosti zajednice zooplanktona. Pored bioloških ispitivanja, praćeni su hemijski parametri kvaliteta vode u trajanju od godinu dana, posmatranih kroz 4 perioda od po tri meseca. Istraživanje je sprovedeno sa ciljem ispitivanja dinamike populacije Cladocera u organski visoko zagađenim, plitkim, stajaćim vodenim ekosistemima i mogućnosti opstanka vrste Daphnia obtusa u datim uslovima sredine. Prema parametrima kvaliteta vode, lagune su se značajno razlikovale samo u pogledu prosečnih vrednosti pH i rastvorenog kiseonika. Diverzitet Cladocera tokom jednogodišnjeg perioda istraživanja bio je relativno visok obzirom na smanjen kvalitet vode, sa ukupno 9 identifikovanih vrsta. Kruskal-Wallis test pokazao je da između laguna ne postoji statistički značajna razlika u ukupnoj brojnosti vrsta tokom perioda ispitivanja. Međutim, ukupna brojnost i diverzitet značajno su se razlikovali u svakoj laguni u zavisnosti od perioda posmatranja, što ukazuje na izražena sezonalna variranja u pogledu kvalitativnog i kvantitativnog sastava zajednice. Ova sezonska varijabilnost ogleda se u maloj brojnosti i potpunoj dominaciji sitne vrste Chydorus sphaericus tokom prvog perioda posmatranja (od kraja februara do sredine maja 2012.), praćenoj povećanjem brojnosti i diverziteta vrsta u drugom periodu (od sredine maja do sredine avgusta 2012) i dominaciji krupne vrste Daphnia obtusa u trećem periodu (od sredine avgusta do kraja novembra 2012.), čija je brojnost ponovo opala nakon dostizanja letnjeg maksimuma, uz ponovno pojavljivanje C. sphaericus u četvrtom periodu (od decembra 2012. do kraja februara 2013. godine). Vrsta koja je na svim tačkama na kojima je obavljeno ispitivanje dostigla najveću brojnost bila je Daphnia obtusa. Njeno prisustvo tipično je za vodene ekosisteme u kojima odsustvuju ribe kao predatori (Vadstein, 1993). Kruskal-Wallis test nije pokazao statistički značajne razlike u brojnosti ove vrste između laguna tokom jednogodišnjeg perioda istraživanja, dok su u svim lagunama utvrđene statistički značajne razlike u brojnosti posmatrane u različitim periodima. Rezultati pokazuju da je D. obtusa bila dominantna vrsta zooplanktona u lagunama (dostižući prosečnu maksimalnu brojnost od 1083 - 1444 ind/l tokom perioda ispitivanja), veoma tolerantna na niske vrednosti rastvorenog kiseonika (u proseku 0.32 – 6.90 mg/l) i visoko organsko opterećenje (BOD 26.65 – 33.09 mg/l)

    Kvalitet vode za piće naselja Žiča (Kraljevo)

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    The objective of this work is to present some characteristics of water supply and drinking water quality of Žiča village. The results of analysis of of water qualty provided by the Kraljevo water supply system to most Žiča residents as well as the quality of mountain water used by fewer residents. The physicochemical and microbiological analysis of raw and desinfected water from the town’s water supply system showed its health safety. The physicochemical and microbiological analysis of mountain water indicated its poorer quality. The microbiological testing of mountain water confirm presence of Escherichia coli and mesophilic bacteria as indicators of faecal contamination. It si recommended that the whole Žiča village be connected to the water supply network of the Kraljevo town to help reduce the risk of waterborne epidemics.U radu su prikazane neke karakteristike vodosnabdevanja i kvalitet vode za piće naselja Žiča tokom 2014. i 2015. godine. Analiziran je kvalitet vode iz gradskog vodovoda Kraljevo kojom se snabdeva većina stanovnika i kvalitet planinske vode koju koristi manji broj stanovnika Žiče. Analize fizičko-hemijskih i mikrobioloških pokazatelja kvaliteta sirove i dezinfikovane vode gradskog vodovoda Kraljevo potvrđuju da je voda za piće zdravstveno bezbedna. Rezultati fizičko-hemijskih i mikrobioloških analiza planinske vode ukazuju na njen lošiji kvalitet. Uočena je bakterijska kontaminacija planinske vode bakterijom Escherichia coli i mezofilnim bakterijama koje su indikatori fekalnog zagađenja. Preporuka rada je da se kompletno naselje Žiča priključi na gradsku vodovodnu mrežu Kraljeva čime bi se smanjila mogućnost nastanka hidričnih epidemija

    Photoacoustic characterization of TiO2 thin-films deposited on Silicon substrate using neural networks

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    In this paper, the possibility of determining the thermal, elastic and geometric characteristics of a thin TiO2 film deposited on a silicon substrate, thickness 30 mikrons, in the frequency range of 20 to 20 kHz with neural networks was analyzed. For this purpose, the substrate parameters remained the known and constant in the two-layer model and nano layer thin-film parameters were changed: thickness, expansion and thermal diffusivity. Prediction of these three parameters was analyzed separately with three neural networks and all of these together by fourth neural network. It was shown that neural network, which analyzed all three parameters at the same time, achieved the highest accuracy, so the use of networks that provide predictions for only one parameter is less reliable.Comment: 21 pages, 5 figure

    Demographic and socioeconomic factors associated with cervical cancer screening among women in Serbia

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    ObjectivesEffective reduction of cervical cancer incidence and mortality requires strategic measures encompassing the implementation of a cost-effective screening technology. Serbia has made significant strides, introducing organized cervical cancer screening in 2012. However, various impediments to screening implementation persist. The aim of the study was to estimate the socioeconomic factors associated with cervical cancer screening among women in Serbia.MethodsData from 2019 National Health Survey of the population of Serbia were used in this study. The study is cross sectional survey on a representative sample of the population of Serbia. Present total number of participants analyzed in survey 6,747.ResultsIn Serbia, 67.2% of women have done a Pap test at any time during their lives, of which 46.1% of women have undergone cervical cancer screening in the past 3 years. About a quarter of women have never undergone a Pap test in their life (24.3%). The probability of never having a Pap test have: the youngest age group (15–24 years) is 1.3 times more likely than the oldest age group (OR = 1.31), unmarried women 0.3 times more often than married women (OR = 0.37), respondents with basic education 0.9 times more often than married women (OR = 0.98), the women of lower socioeconomic status 0.5 times more often than respondents of high socioeconomic status (OR = 0.56).ConclusionEnhancement of the existing CCS would be the appropriate public health approach to decrease the incidence and mortality of cervical cancer in the Republic of Serbia

    Socioeconomic inequalities in the use of dental health care among the adult population in Serbia

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    ObjectivesThe aim of this paper is to assess the association of demografic and socioeconomic determinants with utilization of dental services among Serbian adults.Materials and methodsThe study is a part of the population health research of Serbia, conducted in the period from October to December 2019 by the Institute of Statistics of the Republic of Serbia in cooperation with the Institute of Public Health of Serbia “Dr. Milan JovanovićBatut” and the Ministry of Health of the Republic of Serbia. The research was conducted as a descriptive, cross-sectional analytical study on a representative sample of the population of Serbia. For the purposes of this study, data on the adult population aged 20 years and older were used.ResultsMen were approximately 1.8 times more likely than women to not utilize dental healthcare services (OR = 1.81). The likelihood of not utilizing dental healthcare protection rises with increasing age, reaching its peak within the 65–74 age range (OR = 0.441), after which it declines. Individuals who have experienced marital dissolution due to divorce or the death of a spouse exhibit a higher probability of not utilizing health protection (OR = 1.868). As the level of education and wealth diminishes, the probability of abstaining from health protection increases by 5.8 times among respondents with an elementary school education (OR = 5.852) and 1.7 times among the most economically disadvantaged respondents (OR = 1.745). Regarding inactivity, respondents who are not employed have a 2.6-fold higher likelihood of not utilizing oral health care compared to employed respondents (OR = 2.610).ConclusionThe results suggest that individual sociodemographic factors influence utilization of dental services by Serbian adults and confirmed the existence of socioeconomic disparities

    Three lines of evidence of the hepatotoxicity young researchers of a mixture containing phthalates and bisphenol a: in silico and two in vivo models

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    The extensive usage of bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and bisphenol A (BPA) creates a lot of opportunities for combined human exposure to these hazardous compounds in everyday life and a variety of negative outcomes, including hepatotoxicity. In silico research and two in vivo models were used to investigate the links between a mixture including DEHP, DBP and BPA and liver injury. Bioinformatic analysis was performed by Comparative Toxicogenomics Database, ShinyGO, ToppCluster, and Cytoscape. In vivo subacute study included five groups of rats (n = 6): (1) Control: corn oil, (2) DEHP: 50 mg/kg b.w./day, (3) DBP: 50 mg/kg b.w./day, (4) BPA: 25 mg/kg b.w./day, (5) MIX: DEHP + DBP + BPA. Zebrafish embryos were exposed to the investigated substances in multiple dosages, both alone and in combination (binary and ternary mixtures). Liver damage was linked to 75 DEHP, DBP, and BPA genes, the majority of which were associated with inflammation/oxidative stress, identified as the most relevant molecular pathways. In rats, significant changes in redox status/bioelements’ level and pathohistology were more pronounced or evident only in MIX group, suggesting probable additivity. In a dose-dependent manner, BPA reduced the liver area (LA) index. LA values were decreased by DEHP (2 μg/mL) and DBP (5 μg/mL), whereas LA index was raised by their higher concentrations. In binary mixtures, DBP had a lethal effect at the two highest concentrations, whereas BPA directed hepatotoxicity of the DEHP/DBP/BPA mixture

    Nickel as a potential disruptor of thyroid function: benchmark modelling of human data

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    IntroductionNickel (Ni) is one of the well-known toxic metals found in the environment. However, its influence on thyroid function is not explored enough. Hence, the aim of this study was to analyse the potential of Ni to disrupt thyroid function by exploring the relationship between blood Ni concentration and serum hormone levels (TSH, T4, T3, fT4 and fT3), as well as the parameters of thyroid homeostasis (SPINA-GT and SPINA-GD) by using correlation analysis and Benchmark (BMD) concept.MethodsNi concentration was measured by ICP-MS method, while CLIA was used for serum hormone determination. SPINA Thyr software was used to calculate SPINA-GT and SPINA-GD parameters. BMD analysis was performed by PROAST software (70.1). The limitations of this study are the small sample size and the uneven distribution of healthy and unhealthy subjects, limited confounding factors, as well as the age of the subjects that could have influenced the obtained results.Results and discussionThe highest median value for blood Ni concentration was observed for the male population and amounted 8,278 µg/L. Accordingly, the statistically significant correlation was observed only in the male population, for Ni-fT4 and Ni-SPINA-GT pairs. The existence of a dose-response relationship was established between Ni and all the measured parameters of thyroid functions in entire population and in both sexes. However, the narrowest BMD intervals were obtained only in men, for Ni - SPINA-GT pair (1.36-60.9 µg/L) and Ni - fT3 pair (0.397-66.8 µg/L), indicating that even 78.68 and 83.25% of men in our study might be in 10% higher risk of Ni-induced SPINA-GT and fT3 alterations, respectively. Due to the relationship established between Ni and the SPINA-GT parameter, it can be concluded that Ni has an influence on the secretory function of the thyroid gland in men. Although the further research is required, these findings suggest possible role of Ni in thyroid function disturbances

    Tobacco Smoke Mediated Induction of Sinonasal Microbial Biofilms

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    Cigarette smokers and those exposed to second hand smoke are more susceptible to life threatening infection than non-smokers. While much is known about the devastating effect tobacco exposure has on the human body, less is known about the effect of tobacco smoke on the commensal and commonly found pathogenic bacteria of the human respiratory tract, or human respiratory tract microbiome. Chronic rhinosinusitis (CRS) is a common medical complaint, affecting 16% of the US population with an estimated aggregated cost of $6 billion annually. Epidemiologic studies demonstrate a correlation between tobacco smoke exposure and rhinosinusitis. Although a common cause of CRS has not been defined, bacterial presence within the nasal and paranasal sinuses is assumed to be contributory. Here we demonstrate that repetitive tobacco smoke exposure induces biofilm formation in a diverse set of bacteria isolated from the sinonasal cavities of patients with CRS. Additionally, bacteria isolated from patients with tobacco smoke exposure demonstrate robust in vitro biofilm formation when challenged with tobacco smoke compared to those isolated from smoke naïve patients. Lastly, bacteria from smoke exposed patients can revert to a non-biofilm phenotype when grown in the absence of tobacco smoke. These observations support the hypothesis that tobacco exposure induces sinonasal biofilm formation, thereby contributing to the conversion of a transient and medically treatable infection to a persistent and therapeutically recalcitrant condition

    Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

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    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years
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