236 research outputs found

    Structure, Wettability, Corrosion and Biocompatibility of Nitinol Treated by Alkaline Hydrothermal and Hydrophobic Functionalization for Cardiovascular Applications

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    The main objective of this study is to hydrophobize nitinol (Ni-Ti alloy) for cardiovascular applications. For this purpose, medical nitinol samples were subjected to sodium hydroxide hydrothermal treatments at various temperatures, followed by hexadecyltrimethoxysilane (HDTMS) functionalization. Then, the structure, wettability, corrosion, cytocompatibility and cell adhesion of the prepared samples were evaluated. According to the results, porous blade-shaped layers of sodium titanate were formed on the substrate surface as a result of the alkaline treatment. These nano-rough features offered considerable hydrophobicity after HDTMS processing, where a maximum water contact angle of about 140° was obtained for the sample treated at 120 °C, followed by the HDTMS coating. In contrast to the individual application of the alkaline treatments, the subsequent HDTMS processing improved corrosion resistance in the simulated body fluid. Although all the samples presented appropriate cytocompatibility with respect to human umbilical vein endothelial cells, the cells did not show an adhesion tendency to the hydrophobic surfaces. It is concluded that alkaline hydrothermal and HDTMS processed nitinol can be considered for cardiovascular applications demanding hydrophobic surfaces

    Low temperature joining of ceramic composites

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    A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or cermaic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix

    Low temperature joining of ceramic composites

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    A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or ceramic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix

    Incarceration and mortality in the United States

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    The ongoing COVID-19 pandemic has spotlighted the role of America's overcrowded prisons as vectors of ill health, but robust analyses of the degree to which high rates of incarceration impact population-level health outcomes remain scarce. In this paper, we use county-level panel data from 2927 counties across 43 states between 1983 and 2014 and a novel instrumental variable technique to study the causal effect of penal expansion on age-standardised cause-specific and all-cause mortality rates. We find that higher rates of incarceration have substantively large effects on deaths from communicable, maternal, neonatal, and nutritional diseases in the short and medium term, whilst deaths from non-communicable disease and from all causes combined are impacted in the short, medium, and long run. These findings are further corroborated by a between-unit analysis using coarsened exact matching and a simulation-based regression approach to predicting geographically anchored mortality differences

    Gender, health and the 2030 agenda for sustainable development

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    Gender refers to the social relationships between males and females in terms of their roles, behaviours, activities, attributes and opportunities, and which are based on different levels of power. Gender interacts with, but is distinct from, the binary categories of biological sex. In this paper we consider how gender interacts with the 2030 agenda for sustainable development, including sustainable development goal (SDG) 3 and its targets for health and well-being, and the impact on health equity. We propose a conceptual framework for understanding the interactions between gender (SDG 5) and health (SDG 3) and 13 other SDGs, which influence health outcomes. We explore the empirical evidence for these interactions in relation to three domains of gender and health: gender as a social determinant of health; gender as a driver of health behaviours; and the gendered response of health systems. The paper highlights the complex relationship between health and gender, and how these domains interact with the broad 2030 agenda. Across all three domains (social determinants, health behaviours and health system), we find evidence of the links between gender, health and other SDGs. For example, education (SDG 4) has a measurable impact on health outcomes of women and children, while decent work (SDG 8) affects the rates of occupationrelated morbidity and mortality, for both men and women. We propose concerted and collaborative actions across the interlinked SDGs to deliver health equity, health and well-being for all, as well as to enhance gender equality and women’s empowerment. These proposals are summarized in an agenda for action

    The association between income and life expectancy revisited: deindustrialization, incarceration and the widening health gap

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    BACKGROUND: The health gap between the top and the bottom of the income distribution is widening rapidly in the USA, but the lifespan of America’s poor depends substantially on where they live. We ask whether two major developments in American society, deindustrialization and incarceration, can explain variation among states in life expectancy of those in the lowest income quartile. METHODS: life expectancy estimates at age 40 of those in the bottom income quartile were used to fit panel data models examining the relationship with deindustrialization and incarceration between 2001 and 2014 for all US states. RESULTS: A one standard deviation (s.d.) increase in deindustrialization (mean = 11.2, s.d. = 3.5) reduces life expectancy for the poor by 0.255 years [95% confidence interval (CI): 0.090–0.419] and each additional prisoner per 1000 residents (mean = 4.0, s.d. = 1.5) is associated with a loss of 0.468 years (95% CI: 0.213–0.723). Our predictors explain over 20% of the state-level variation in life expectancy among the poor and virtually the entire increase in the life expectancy gap between the top and the bottom income quartiles since the turn of the century. CONCLUSIONS: In the USA between 2001 and 2014, deindustrialization and incarceration subtracted roughly 2.5 years from the lifespan of the poor, pointing to their role as major health determinants. Future research must remain conscious of the upstream determinants and the political economy of public health. If public policy responses to growing health inequalities are to be effective, they must consider strengthening industrial policy and ending hyper-incarceration

    Economic decline, incarceration, and mortality from drug use disorders in the USA between 1983 and 2014: an observational analysis

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    Background: Drug use disorders are an increasing cause of disability and early death in the USA, with substantial geographical variation. We aimed to investigate the associations between economic decline, incarceration rates, and age-standardised mortality from drug use disorders at the county level in the USA. // Methods: In this observational analysis, we examined age-standardised mortality data from the US National Vital Statistics System and the Institute for Health Metrics and Evaluation, household income data from the US Census Bureau, and county-level jail and prison incarceration data from the Vera Institute of Justice for 2640 US counties between 1983 and 2014. We also extracted data on county-level control variables from the US Census Bureau, the National Center for Health Statistics, and the US Centers for Disease Control and Prevention. We used a two-way fixed-effects panel regression to examine the association between reduced household income, incarceration, and mortality from drug use disorders within counties over time. To assess between-county variation, we used coarsened exact matching and a simulation-based modelling approach. // Findings: After adjusting for key confounders, each 1 SD decrease in median household income was associated with an increase of 12·8% (95% CI 11·0–14·6; p<0·0001) in drug-related deaths within counties. Each 1 SD increase in jail and prison incarceration rates was associated with an increase of 1·5% (95% CI 1·0–2·0; p<0·0001) and 2·6% (2·1–3·1; p<0·0001) in drug-related mortality, respectively. The association between drug-related mortality and income and incarceration persisted after controlling for local opioid prescription rates. Our model accounts for a large proportion of within-county variation in mortality from drug use disorders (R2=0·975). Between counties, high rates of incarceration were associated with a more than 50% increase in drug-related deaths. // Interpretation: Reduced household income and high incarceration rates are associated with poor health. The rapid expansion of the prison and jail population in the USA over the past four decades might have contributed to the increasing number of deaths from drug use disorders

    Prognostic Impact of PHIP Copy Number in Melanoma: Linkage to Ulceration

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    Ulceration is an important prognostic factor in melanoma whose biologic basis is poorly understood. Here we assessed the prognostic impact of pleckstrin homology domain-interacting protein (PHIP) copy number and its relationship to ulceration. PHIP copy number was determined using fluorescence in situ hybridization (FISH) in a tissue microarray cohort of 238 melanomas. Elevated PHIP copy number was associated with significantly reduced distant metastasis-free survival (DMFS; P=0.01) and disease-specific survival (DSS; P=0.009) by Kaplan–Meier analyses. PHIP FISH scores were independently predictive of DMFS (P=0.03) and DSS (P=0.03). Increased PHIP copy number was an independent predictor of ulceration status (P=0.04). The combined impact of increased PHIP copy number and tumor vascularity on ulceration status was highly significant (P<0.0001). Stable suppression of PHIP in human melanoma cells resulted in significantly reduced glycolytic activity in vitro, with lower expression of lactate dehydrogenase 5, hypoxia-inducible factor 1 alpha subunit, and vascular endothelial growth factor, and was accompanied by reduced microvessel density in vivo. These results provide further support for PHIP as a molecular prognostic marker of melanoma, and reveal a significant linkage between PHIP levels and ulceration. Moreover, they suggest that ulceration may be driven by increased glycolysis and angiogenesis

    Hookah smoking is strongly associated with diabetes mellitus, metabolic syndrome and obesity: a population-based study

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    Objectives The adverse effects of cigarette smoking have been widely studied before, whilst the effects of hookah smoking has received less attention, although it is a common habit in the Middle East. Here we have investigated the effects of cigarette and hookah smoking on biochemical characteristics in a representative population sample derived from the Mashhad stroke and heart atherosclerotic disorder (MASHAD) cohort study, from Northeastern Iran. Study design A total of 9840 subjects from the MASHAD population study were allocated to five groups; non-smokers (6742), ex-smokers (976), cigarette smokers (864), hookah smokers (1067), concomitant cigarette and hookah smokers (41). Methods Baseline characteristics were recorded in a questionnaire. Biochemical characteristics were measured by routine methods. Data were analyzed using SPSS software and p < 0.05 was considered significant. Results After adjustment for age and sex; the presence of CVD, obesity, metabolic syndrome, DM and dyslipidemia were significantly (p < 0.001) related to smoking status. After multivariate analysis, HDL (p < 0.001), WBC (p < 0.001), MCV (p < 0.05), PLT (p < 0.01) and RDW (p < 0.001), and the presence of CVD (p < 0.01), obesity (p < 0.001), metabolic syndrome (p < 0.05) and DM (p < 0.01) remained significant between cigarette smokers and non-smokers. Between hookah smokers and non-smokers; uric acid (p < 0.001), PLT (p < 0.05) and RDW (p < 0.05), and the presence of obesity (p < 0.01), metabolic syndrome (p < 0.001), diabetes (p < 0.01) and dyslipidemia (p < 0.01) remained significant after logistic regression. Conclusion There was a positive association between hookah smoking and metabolic syndrome, diabetes, obesity and dyslipidemia which was not established in cigarette smoking
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