1,282 research outputs found

    Cadmium contamination of agricultural soils and crops resulting from sphalerite weathering.

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    The biogeochemistry and bioavailability of cadmium, released during sphalerite weathering in soils, were investigated under contrasting agricultural scenarios to assess health risks associated with sphalerite dust transport to productive soils from mining. Laboratory experiments (365 d) on temperate and sub-tropical soils amended with sphalerite (<63 Όm, 0.92 wt.% Cd) showed continuous, slow dissolution (0.6-1.2% y(-1)). Wheat grown in spiked temperate soil accumulated ≈38% (29 Όmol kg(-1)) of the liberated Cd, exceeding food safety limits. In contrast, rice grown in flooded sub-tropical soil accumulated far less Cd (0.60 Όmol kg(-1)) due to neutral soil pH and Cd bioavailability was possibly also controlled by secondary sulfide formation. The results demonstrate long-term release of Cd to soil porewaters during sphalerite weathering. Under oxic conditions, Cd may be sufficiently bioavailable to contaminate crops destined for human consumption; however flooded rice production limits the impact of sphalerite contamination

    TGF-beta receptor 2 downregulation in tumour-associated stroma worsens prognosis and high-grade tumours show more tumour-associated macrophages and lower TGF-beta1 expression in colon carcinoma: a retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Histological phenotype and clinical behaviour of malignant tumours are not only dependent on alterations in the epithelial cell compartment, but are affected by their interaction with inflammatory cells and tumour-associated stroma. Studies in animal models have shown influence of tumour-associated macrophages (TAM) on histological grade of differentiation in colon carcinoma. Disruption of transforming growth factor beta (TGF-beta) signalling in tumour cells is related to more aggressive clinical behaviour. Expression data of components of this pathway in tumour-associated stroma is limited.</p> <p>Methods</p> <p>Tissue micro arrays of 310 colon carcinomas from curatively resected patients in UICC stage II and III were established. In a first step we quantified amount of CD68 positive TAMs and expression of components of TGF-beta signalling (TGF-beta1, TGF-beta receptors type 1 and 2, Smad 3 and 4) in tumour and associated stroma. Further we analyzed correlation to histological and clinical parameters (histological grade of differentiation (low-grade (i.e. grade 1 and 2) vs. high-grade (i.e. grade 3 and 4)), lymph node metastasis, distant metastasis, 5 year cancer related survival) using Chi-square or Fisher's exact test, when appropriate, to compare frequencies, Kaplan-Meier method to calculate 5-year rates of distant metastases and cancer-related survival and log rank test to compare the rates of distant metastases and survival. To identify independent prognostic factors Cox regression analysis including lymph node status and grading was performed.</p> <p>Results</p> <p>High-grade tumours and those with lymph node metastases showed higher rates of TAMs and lower expression of TGF-beta1. Loss of nuclear Smad4 expression in tumor was associated with presence of lymph node metastasis, but no influence on prognosis could be demonstrated. Decrease of both TGF-beta receptors in tumour-associated stroma was associated with increased lymph node metastasis and shorter survival. Stromal TGF-beta receptor 2 expression was an independent prognostic factor for cancer related survival.</p> <p>Conclusion</p> <p>Histological phenotype and clinical behaviour of colon cancer is not only influenced by mutational incidents in tumour cells but also affected by interaction of tumour tissue with inflammatory cells like macrophages and associated stroma and TGF-beta signalling is one important part of this crosstalk. Further studies are needed to elucidate the exact mechanisms.</p

    Ethnic discrimination prevalence and associations with health outcomes: data from a nationally representative cross-sectional survey of secondary school students in New Zealand

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    <p>Abstract</p> <p>Background</p> <p>Reported ethnic discrimination is higher among indigenous and minority adult populations. There is a paucity of nationally representative prevalence studies of ethnic discrimination among adolescents. Experiencing ethnic discrimination has been associated with a range of adverse health outcomes. NZ has a diverse ethnic population. There are health inequalities among young people from Māori and Pacific ethnic groups.</p> <p>Methods</p> <p>9107 randomly selected secondary school students participated in a nationally representative cross-sectional health and wellbeing survey conducted in 2007. The prevalence of ethnic discrimination by health professionals, by police, and ethnicity-related bullying were analysed. Logistic regression was used to examine the associations between ethnic discrimination and six health/wellbeing outcomes: self-rated health status, depressive symptoms in the last 12 months, cigarette smoking, binge alcohol use, feeling safe in ones neighbourhood, and self-rated school achievement.</p> <p>Results</p> <p>There were significant ethnic differences in the prevalences of ethnic discrimination. Students who experienced ethnic discrimination were less likely to report excellent/very good/good self-rated general health (OR 0.51; 95% CI 0.39, 0.65), feel safe in their neighbourhood (OR 0.48; 95% CI 0.40, 0.58), and more likely to report an episode of binge drinking in the previous 4 weeks (OR 1.77; 95% CI 1.45, 2.17). For all these outcomes the odds ratios for the group who were 'unsure' if they had experienced ethnic discrimination were similar to those of the 'yes' group.</p> <p>Ethnicity stratified associations between ethnic discrimination and the depression, cigarette smoking, and self-rated school achievement are reported. Within each ethnic group participants reporting ethnic discrimination were more likely to have adverse outcomes for these three variables. For all three outcomes the direction and size of the association between experience of ethnic discrimination and the outcome were similar across all ethnic groups.</p> <p>Conclusions</p> <p>Ethnic discrimination is more commonly reported by Indigenous and minority group students. Both experiencing and being 'unsure' about experiencing ethnic discrimination are associated with a range of adverse health/wellbeing outcomes. Our findings highlight the progress yet to be made to ensure that rights to be free from ethnic discrimination are met for young people living in New Zealand.</p

    Enhanced physical health screening for people with severe mental illness in Hong Kong: results from a one-year prospective case series study

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    Background People with severe mental illness have significantly poorer physical health compared to the general population; previous health screening studies conducted outside Asian countries have demonstrated the potential in addressing this issue. This case series aimed to explore the effects and utility of integrating an enhanced physical health screening programme for community dwelling patients with severe mental illness into routine clinical practice in Hong Kong. Method This study utilises a consecutive prospective case series design. The serious mental illness Health Improvement Profile (HIP) was used as a screening tool at baseline and repeated at 12 months follow-up. Results A total of 148 community-based patients with severe mental illness completed the study. At one year follow-up analysis showed a significant improvement in self-reported levels of exercise and a reduction in the numbers of patients prescribed medications for diabetes However, mean waist circumference increased at follow-up. In addition to the statistically significant results some general trends were observed, including: a lack of deterioration in most areas of cardiovascular risk; a reduction in medicines prescribed for physical health problems; and general improvements in health behaviours over the 12 month period. Conclusions The findings demonstrate that using the HIP is feasible and acceptable in Hong Kong. The results of the enhanced physical health-screening programme are promising, but require further testing using a randomised controlled trial design in order to more confidently attribute the improvements in well-being and health behaviours to the HIP. Trial registration Clinical trial registration number: ISRCTN1258247

    Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

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    The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse

    Enhanced physical health screening for people with severe mental illness in Hong Kong: results from a one-year prospective case series study

    Get PDF
    Background People with severe mental illness have significantly poorer physical health compared to the general population; previous health screening studies conducted outside Asian countries have demonstrated the potential in addressing this issue. This case series aimed to explore the effects and utility of integrating an enhanced physical health screening programme for community dwelling patients with severe mental illness into routine clinical practice in Hong Kong. Method This study utilises a consecutive prospective case series design. The serious mental illness Health Improvement Profile (HIP) was used as a screening tool at baseline and repeated at 12 months follow-up. Results A total of 148 community-based patients with severe mental illness completed the study. At one year follow-up analysis showed a significant improvement in self-reported levels of exercise and a reduction in the numbers of patients prescribed medications for diabetes However, mean waist circumference increased at follow-up. In addition to the statistically significant results some general trends were observed, including: a lack of deterioration in most areas of cardiovascular risk; a reduction in medicines prescribed for physical health problems; and general improvements in health behaviours over the 12 month period. Conclusions The findings demonstrate that using the HIP is feasible and acceptable in Hong Kong. The results of the enhanced physical health-screening programme are promising, but require further testing using a randomised controlled trial design in order to more confidently attribute the improvements in well-being and health behaviours to the HIP. Trial registration Clinical trial registration number: ISRCTN1258247

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≄20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal
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