56 research outputs found

    Odabir bioloških pokazatelja pri profesionalnoj izloženosti toluenu i ksilenu

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    Results of a comparative study of occupational exposure to toluene and xylene are presented. The study was carried out in a group of 24 workers from a paint factory and aimed to determine the most appropriate exposure indicators for use in biological monitoring. Measurements included toluene and xylene in blood and their metabolites in urine. Toluene in blood proved to be the best indicator of toluene exposure, and both xylene in blood and its only major metabolite methylhippuric acid in urine to be reliable indicators of xylene exposure, The validity of hippuric acid and o-cresol as toluene exposure indicators has not been confirmed.Proveđeno je komparativno istraživanje profesionalne izloženosti toluenu i ksilenu radi odabira najpogodnijih bioloških pokazatelja u biološkom monitoringu. Određeni su toluen i ksilen u krvi i njihovi metaboliti u urinu 24-ju radnika profesionalno izloženih toluenu i ksilenu. Toluen u krvi pokazao se najboljim pokazateljem izloženosti toluenu, dok su i ksilen u krvi i njegov glavni metabolit metilhipurna kiselina pouzdani pokazatelji izloženosti ksilenu. Vrijednosti hipurne kiseline odnosno o-krezola nisu jednoznačni pokazatelji izloženosti toluenu što je poznato iz ranijih istraživanja a potvrđeno je i našim mjerenjima

    Dermanyssus gallinae in layer farms in Kosovo: a high risk for salmonella prevalence

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    Background The poultry red mite (PRM), Dermanyssus gallinae (D.g.) is a serious ectoparasitic pest of poultry and potential pathogen vector. The prevalence of D. g. and the prevalence of Salmonella spp. within mites on infested laying poultry farms were investigated in Kosovo. Findings In total, 14 populated layer farms located in the Southern Kosovo were assessed for D. g. presence. Another two farms in this region were investigated 6 months after depopulation. Investigated flocks were all maintained in cages, a common housing system in Kosovo. A total of eight farms were found to be infested with D. g. (50%) at varying levels, including the two depopulated farms. The detection of Salmonella spp. from D. g. was carried out using PCR. Out of the eight layer farms infested with D. g., Salmonella spp. was present in mites on three farms (37.5%). Conclusions This study confirms the high prevalence of D. g. in layer flocks in Kosovo and demonstrates the link between this mite and the presence of Salmonella spp. on infested farms

    Morphology and density of post-CME current sheets

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    Eruption of a coronal mass ejection (CME) drags and "opens" the coronal magnetic field, presumably leading to the formation of a large-scale current sheet and the field relaxation by magnetic reconnection. We analyze physical characteristics of ray-like coronal features formed in the aftermath of CMEs, to check if the interpretation of this phenomenon in terms of reconnecting current sheet is consistent with the observations. The study is focused on measurements of the ray width, density excess, and coronal velocity field as a function of the radial distance. The morphology of rays indicates that they occur as a consequence of Petschek-like reconnection in the large scale current sheet formed in the wake of CME. The hypothesis is supported by the flow pattern, often showing outflows along the ray, and sometimes also inflows into the ray. The inferred inflow velocities range from 3 to 30 km s1^{-1}, consistent with the narrow opening-angle of rays, adding up to a few degrees. The density of rays is an order of magnitude larger than in the ambient corona. The density-excess measurements are compared with the results of the analytical model in which the Petschek-like reconnection geometry is applied to the vertical current sheet, taking into account the decrease of the external coronal density and magnetic field with height. The model results are consistent with the observations, revealing that the main cause of the density excess in rays is a transport of the dense plasma from lower to larger heights by the reconnection outflow

    Smoking is Associated with Hypermethylation of the APC 1A Promoter in Colorectal Cancer: the ColoCare Study

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    Smoking tobacco is a known risk factor for the development of colorectal cancer, and for mortality associated with the disease. While smoking has been reported to be associated with changes in DNA methylation in blood and in lung tumour tissues, there has been scant investigation of how epigenetic factors may be implicated in the increased risk of developing colorectal cancer. To identify epigenetic changes associated with smoking behaviours, we performed epigenome-wide analysis of DNA methylation in colorectal tumours from 36 never smokers, 47 former smokers and 13 active smokers, and adjacent mucosa from 49 never smokers, 64 former smokers and 18 active smokers. Our analyses identified 15 CpG sites within the APC 1A promoter that were significantly hypermethylated and 14 CpG loci within the NFATC1 gene body that were significantly hypomethylated (pLIS<1x10-5) in tumours of active smokers. The APC 1A promoter was hypermethylated in 7 of 36 tumours from never smokers (19%), 12 of 47 tumours from former smokers (26%), and 8 of 13 tumours from active smokers (62%). Promoter hypermethylation was positively associated with duration of smoking (Spearman rank correlation, =0.26, p=0.03) and was confined to tumours, with hypermethylation never observed in adjacent mucosa. Further analysis of adjacent mucosa revealed significant hypomethylation of four loci associated with the TNXB gene in tissue from active smokers. Our findings provide exploratory evidence for hypermethylation of the key tumour suppressor gene APC being implicated in smoking-associated colorectal carcinogenesis. Further work is required to establish the validity of our observations in independent cohorts

    A Quantitative Model of Energy Release and Heating by Time-dependent, Localized Reconnection in a Flare with a Thermal Loop-top X-ray Source

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    We present a quantitative model of the magnetic energy stored and then released through magnetic reconnection for a flare on 26 Feb 2004. This flare, well observed by RHESSI and TRACE, shows evidence of non-thermal electrons only for a brief, early phase. Throughout the main period of energy release there is a super-hot (T>30 MK) plasma emitting thermal bremsstrahlung atop the flare loops. Our model describes the heating and compression of such a source by localized, transient magnetic reconnection. It is a three-dimensional generalization of the Petschek model whereby Alfven-speed retraction following reconnection drives supersonic inflows parallel to the field lines, which form shocks heating, compressing, and confining a loop-top plasma plug. The confining inflows provide longer life than a freely-expanding or conductively-cooling plasma of similar size and temperature. Superposition of successive transient episodes of localized reconnection across a current sheet produces an apparently persistent, localized source of high-temperature emission. The temperature of the source decreases smoothly on a time scale consistent with observations, far longer than the cooling time of a single plug. Built from a disordered collection of small plugs, the source need not have the coherent jet-like structure predicted by steady-state reconnection models. This new model predicts temperatures and emission measure consistent with the observations of 26 Feb 2004. Furthermore, the total energy released by the flare is found to be roughly consistent with that predicted by the model. Only a small fraction of the energy released appears in the super-hot source at any one time, but roughly a quarter of the flare energy is thermalized by the reconnection shocks over the course of the flare. All energy is presumed to ultimately appear in the lower-temperature T<20 MK, post-flare loops

    Review on Current Sheets in CME Development: Theories and Observations

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    Points-based physical activity: a novel approach to facilitate changes in body composition in inactive women with overweight and obesity

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    Background Physical activity (PA) interventions for the promotion of weight-management may benefit from increased choice and flexibility to overcome commonly-perceived barriers to PA. The aim of this study was to investigate the effects of a novel “points-based” approach to PA on body composition in inactive women, who are overweight or obese. Methods Seventy-six overweight or obese, inactive women were randomly allocated to one of three conditions: ‘Points-based’ PA (PBPA; 30 “PA points”•week− 1), Structured exercise (StructEx; 150 min moderate-intensity exercise•week− 1) or control (CONT; continue habitual inactive lifestyle) for a 24-week intervention. PA points for activities were adapted from MET values, and 30 points was equivalent to 150 min of brisk walking. Measures of body composition (dual-energy x-ray absorptiometry) and anthropometry were obtained at weeks 0, 4, 12 and 24. Self-report activities were recorded weekly, with objective measures of PA (tri-axial accelerometry) and self-report measures of food intake obtained at weeks 0 and 24. Results Fifty-eight women completed the study and provided data for primary outcomes. Of these, n = 41 and n = 19 provided data for food intake and objectively assessed PA. Mixed-design ANOVAs demonstrated that those in PBPA achieved a significant weight-loss at 24 weeks of − 3.3 ± 5.9 kg (− 3.4 ± 7.1%, p = 0.004). Waist circumference was reduced in PBPA at 24 weeks (− 2.8 ± 4.6 cm), compared with CONT (+ 2.1 ± 6.6 cm, p = 0.024). There was a trend for greater reductions in fat mass for those in PBPA vs. CONT (− 2.3 ± 4.6 kg vs. + 0.1 ± 2.0 kg, p = 0.075). Android fat was reduced in PBPA at both 12 weeks (− 6.1 ± 12.6%, p = 0.005) and 24 weeks (− 10.1 ± 18.4%, p = 0.005), while there was a trend for greater reductions in visceral adipose tissue in PBPA (− 5.8 ± 26.0%) vs. CONT at 24 weeks (+ 7.8 ± 18.3%, p = 0.053). Body composition, body weight and waist circumference were unchanged in StructEx. There were trends for increases in light-activity and reductions in sedentary time in PBPA. There was a trend for a reduction in daily energy intake of − 445 ± 564 kcal (p = 0.074), and a significant reduction in daily fat intake (p = 0.042) in PBPA. Conclusion A “points-based” approach to physical activity appears to be an effective strategy for inducing modest reductions in body weight and body fat in inactive women with overweight and obesity

    A review of bioanalytical techniques for evaluation of cannabis (Marijuana, weed, Hashish) in human hair

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    Cannabis products (marijuana, weed, hashish) are among the most widely abused psychoactive drugs in the world, due to their euphorigenic and anxiolytic properties. Recently, hair analysis is of great interest in analytical, clinical, and forensic sciences due to its non-invasiveness, negligible risk of infection and tampering, facile storage, and a wider window of detection. Hair analysis is now widely accepted as evidence in courts around the world. Hair analysis is very feasible to complement saliva, blood tests, and urinalysis. In this review, we have focused on state of the art in hair analysis of cannabis with particular attention to hair sample preparation for cannabis analysis involving pulverization, extraction and screening techniques followed by confirmatory tests (e.g., GC–MS and LC–MS/MS). We have reviewed the literature for the past 10 years’ period with special emphasis on cannabis quantification using mass spectrometry. The pros and cons of all the published methods have also been discussed along with the prospective future of cannabis analysis
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