4,559 research outputs found

    A Mathematical Model For Evaluating Energy Consumptions In Life Cycle Assessment.

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    This paper takes up the ecobalance topic giving prominence to a calculation procedure of necessary energy consumptions for the production of a product in the different phases of a whole life cycle. Are used to identify all stages of the life cycle are determined and simplified formulas for the calculation of specific energy consumption. Is also examined a case where the components of the final product are up to 8. The model is valid for any type of product and through operations research (ie, placing constraints on the variables) you could get to optimal solutions minimizing the objective function

    Oncogenic transformation of mesenchymal stem cells decreases Nrf2 expression favoring in vivo tumor growth and poorer survival

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    BACKGROUND: The transcription factor Nrf2 is a key regulator of the cellular antioxidant response, and its activation by chemoprotective agents has been proposed as a potential strategy to prevent cancer. However, activating mutations in the Nrf2 pathway have been found to promote tumorigenesis in certain models. Therefore, the role of Nrf2 in cancer remains contentious. METHODS: We employed a well-characterized model of stepwise human mesenchymal stem cell (MSC) transformation and breast cancer cell lines to investigate oxidative stress and the role of Nrf2 during tumorigenesis. The Nrf2 pathway was studied by microarray analyses, qRT-PCR, and western-blotting. To assess the contribution of Nrf2 to transformation, we established tumor xenografts with transformed MSC expressing Nrf2 (n = 6 mice per group). Expression and survival data for Nrf2 in different cancers were obtained from GEO and TCGA databases. All statistical tests were two-sided. RESULTS: We found an accumulation of reactive oxygen species during MSC transformation that correlated with the transcriptional down-regulation of antioxidants and Nrf2-downstream genes. Nrf2 was repressed in transformed MSC and in breast cancer cells via oncogene-induced activation of the RAS/RAF/ERK pathway. Furthermore, restoration of Nrf2 function in transformed cells decreased reactive oxygen species and impaired in vivo tumor growth (P = 0.001) by mechanisms that included sensitization to apoptosis, and a decreased hypoxic/angiogenic response through HIF-1α destabilization and VEGFA repression. Microarray analyses showed down-regulation of Nrf2 in a panel of human tumors and, strikingly, low Nrf2 expression correlated with poorer survival in patients with melanoma (P = 0.0341), kidney (P = 0.0203) and prostate (P = 0.00279) cancers. CONCLUSIONS: Our data indicate that oncogene-induced Nrf2 repression is an adaptive response for certain cancers to acquire a pro-oxidant state that favors cell survival and in vivo tumor growth

    Human colon cancer cell lines show a diverse pattern of nitric oxide synthase gene expression and nitric oxide generation.

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    A panel of human colonic adenocarcinoma cell lines was examined both for expression of mRNAs of the nitric oxide synthase (NOS) gene family and for evidence of enzymic activity based on citrulline and nitrite (NO2-) formation. Reverse transcription-polymerase chain reaction (RT-PCR), revealed that all lines (SW480, SW620, DLD-1 and WiDr) expressed mRNA for the Ca(2+)-dependent endothelial (e)NOS, while SW480 cells also expressed the Ca(2+)-dependent neuronal (n)NOS. The mRNA for the Ca(2+)-independent inducible (i)NOS was expressed both by cytokine-stimulated and by unstimulated SW480, SW620 and DLD-1 cells, but none was seen at any time in the WiDr cells. There was, however, little correlation between mRNA expression and enzymic activity based on citrulline and NO2- formation. Thus none of the cell lines exhibited measurable Ca(2+)-dependent NOS activity, while Ca(2+)-independent NOS activity was seen in all but the WiDr cells. Furthermore, DLD-1 cells generated citrulline with resultant NO2- formation only after stimulation with lipopolysaccharide (LPS) and/or cytokines, while SW480 and SW620 did so constitutively. Thus RT-PCR studies indicate that tumour cells of similar epithelial origin display a diverse pattern of NOS gene family expression, and parallel biochemical studies clearly indicate that such expression does not always result in measurable enzymic activity leading to the generation of NO

    A Framework for Participatory Impact Assessment: involving stakeholders in European policy making, a case study of land use change in Malta

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    A Framework for Participatory Impact Assessment is presented for use within European land use policy impact assessment. The context and rationale for the development of the Framework are outlined, both in the context of European policy making and within a project called "Sustainability Impact Assessment: Tools for Environmental, Social and Economic Effects of Multifunctional Land Use in European Regions". A detailed description of the sequence of methods that make up the Framework is provided, followed by illustrations and details of the practical application and results from a case study in Malta, where the Framework was used to carry out an impact assessment of biodiversity policies. After reporting on the reflections of the research team and valuable feedback provided by Maltese stakeholders, the Framework’s ability to enhance the quality, credibility and legitimacy of European policy impact assessment is discusse

    Acute insulin response following exercise and its association to lipid changes in sedentary African-American women

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    Sedentary African-American (AA) women are at increased risk of hypertension, dyslipidemias, metabolic syndrome, and impaired insulin response to exercise. The purpose of the study was to determine the effects of a single bout of aerobic exercise on fasting serum insulin and glucose concentrations following 1464 kJ (350 kcal) of exercise and to determine if this response was associated with serum lipid concentrations in overweight AA women. Premenopausal AA women (n = 11, mean ± SD, age = 32.5 ± 4.8 yr., BMI = 29.8 ± 4.8 kg·m-2, % fat = 35.6 ± 6.3, VO2peak = 21.5 ± 3.6 ml·kg-1·min-1, total cholesterol = 4.8 ± 0.6 mmol·L-1, triglycerides = 0.60 ± 0.2 mmol·L-1, HDLC = 3.3 ± 0.5 mg·dL-1) performed 1464 kJ (350 kcal) of treadmill exercise at 60%-70%VO2peak. Fasting plasma insulin and glucose concentrations were collected 24-h prior to, and immediately, 24-h, and 48 h following exercise. Fasting insulin concentration increased immediately following exercise (Baseline=77.1 ± 10.42 vs. Immediately=117.4 ± 15.28 μU·mL-1, 95%CI= 32.71, 47.89; P<0.05). The change in insulin concentration from 24-h pre- to 24-h post-exercise was correlated with BMI (r= 0.51), VO2peak (r= -0.47), and the change in lipoprotein lipase activity (r=0.37) (P<0.05 for all). In conclusion, in sedentary AA women, the insulin response immediately following exercise may be elevated, and is not suppressed below pre-exercise concentrations during the 48-h following exercise. The insulin response 24-h following exercise is modestly associated with markers of lipoprotein metabolism

    Exploring working conditions as determinants of job satisfaction: an empirical test among Catalonia service workers

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    Job satisfaction is particularly important in the service industry since it involves direct contact with customers and thus has a direct influence on company performance. We analyzed the impact of ten working conditions on job satisfaction by means of structural equation modelling in a representative stratified random sample of 1553 service sector employees in Catalonia (Spain). We found significant effects in social aspects (recognition of a job well done and social support), followed by psychological loads (emotional demands and job insecurity) and by task contents (development & meaning and predictability). These variables explained 50% of the variance in job satisfaction

    Enzyme prodrug therapy achieves site-specific, personalized physiological responses to the locally produced nitric oxide

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    Nitric oxide (NO) is a highly potent but short-lived endogenous radical with a wide spectrum of physiological activities. In this work, we developed an enzymatic approach to the site-specific synthesis of NO mediated by biocatalytic surface coatings. Multilayered polyelectrolyte films were optimized as host compartments for the immobilized β-galactosidase (β-Gal) enzyme through a screen of eight polycations and eight polyanions. The lead composition was used to achieve localized production of NO through the addition of β-Gal–NONOate, a prodrug that releases NO following enzymatic bioconversion. The resulting coatings afforded physiologically relevant flux of NO matching that of the healthy human endothelium. The antiproliferative effect due to the synthesized NO in cell culture was site-specific: within a multiwell dish with freely shared media and nutrients, a 10-fold inhibition of cell growth was achieved on top of the biocatalytic coatings compared to the immediately adjacent enzyme-free microwells. The physiological effect of NO produced via the enzyme prodrug therapy was validated ex vivo in isolated arteries through the measurement of vasodilation. Biocatalytic coatings were deposited on wires produced using alloys used in clinical practice and successfully mediated a NONOate concentration-dependent vasodilation in the small arteries of rats. The results of this study present an exciting opportunity to manufacture implantable biomaterials with physiological responses controlled to the desired level for personalized treatment

    Cadaveric Penile Prosthesis Workshop training improves surgical confidence levels of urologists: South Asian Society for Sexual Medicine course survey.

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    Objectives To analyze the impact of South Asia’s first cadaveric hands-on workshop on urologists’ training in inflatable penile prosthesis surgery. Methods A total of 72 urologists/andrologists participated in the 2019 South Asian Society for Sexual Medicine Pre-congress Penile Prosthesis hands-on workshop. The workshop included 4 h of lectures and 2 h of hands-on cadaveric laboratory experience using three-piece inflatable penile prosthesis. The Shapiro–Wilk test was used on self-rated procedural confidence levels, which proved the normality. A non-parametric McNemar test was used to examine the change in the number of correct answers. Results Of those who attended the cadaver laboratory, just 45 who answered the survey both before and after the workshop were included for analysis. Significant objective improvements were noted in procedural knowledge test scores (44.30 ± 0.027 vs 72.44 ± 0.024, P < 0.05) and median surgical confidence levels (4 vs 3 and 2, P < 0.001) of the urologists after the completion of the workshop. Conclusions Cadaveric hands-on workshop training improves urologists’ procedural knowledge and surgical confidence levels in carrying out three-piece inflatable penile prosthesis surgery. The feasibility of such workshops should be considered in increasing the surgical expertise of general urologists in prosthetic urology.pre-print905 K
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