170 research outputs found

    Utjecaj aluminija i titana na mikrostrukturu i kvalitetu željeznih odljevaka s udjelom vermikularnog grafita

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    The contribution is aimed at study of influence of chemical composition of compacted graphite cast iron (CGI) on microstructure and surface quality of castings, particularly on the occurrence of pinholes. It has been found out that aluminium and titanium in CGI effect the formation of this defect in castings. Aluminium content in the range of 0,02 up to 0,1 % is critical. Increased occurrence of pinholes was also determined with Ti contents above 0,1%. On the same set of experimental castings it has been found out that increased contents of those elements on the other hand support the crystallization of compacted graphite. But the utilization of that method for control of CGI microstructure is limited with a possibility of formation of surface defects in castings – pinholes, but also coldshuts and shrinkage cavities.Rad istražuje utjecaj kemijskog sastava odljevaka čelika s udjelom vermikularnog grafita na njihovu mikrostrukturu i površinska svojstva, osobito pri pojavi poroznosti. Utvrđen je utjecaj aluminija i titana na nastanak pora u odljevcima. Kritičan je udio aluminija između 0,02 i 0,1%. Također, pore su učestalije pri udjelu titana iznad 0,1%. Na istim uzorcima eksperimentalnih odljevaka utvrđeno je i kako povišeni udjeli ovih elemenata istodobno potpomažu kristalizaciju vermikulanog grafita. Primjena metode za kontrolu mikrostrukture odljevaka s vermikularnim grafitom (CGI) limitirana je, uz mogućnost pojave površinskih nedostataka odljevaka u vidu pora, hladnih zavara i šupljina nastalih skupljanjem

    A Comparative Analysis of the Interactions of the E6 Proteins from Cutaneous and Genital Papillomaviruses with p53 and E6AP in Correlation to Their Transforming Potential

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    AbstractA common necessity for all papillomaviruses is to induce DNA synthesis in quiescent cells. This is commonly achieved by the E7 gene product, which interferes with the function of members of the retinoblastoma family controlling transition from the G1-phase to the S-phase of the cell cycle. Uncontrolled entry into S-phase activates, however, negative growth control signals which have to be bypassed to achieve production of progeny viruses. In addition to inherent activities of the E7 protein, high risk genital types encode an E6 protein that overcomes p53-mediated G1-arrest and apoptosis in concert with the cellular factor E6AP by targeting p53 for the enhanced ubiquitin-dependent degradation. The key question, which of these functions of genital E6 and E7 proteins is responsible for the carcinogenic phenotype, is still not completely answered. In contrast to high risk genital types no immortalizing or transforming activities have been found for the E7 proteins of the high risk cutaneous HPV8 and 47. On the other hand the ability of the E6 protein to transform established rodent fibroblasts seems to be a property shared by high risk genital and cutaneous types. To examine the existence of a common E6-mediated transforming pathway for both virus groups we compared the properties of the cutaneous E6 proteins with already known functions of E6 proteins of genital viruses. For this we analyzed the E6 proteins of low risk and high risk cutaneous and genital papillomaviruses with respect to cell transformation, to their abilities to bind, degradate, and influence the activity of human p53, and to bind E6AP. The results of our study demonstrate a clear lack of interaction between the transforming E6 proteins of HPV1 and HPV8 and both cellular proteins p53 and E6AP. In contrast, we found E6AP-independent binding of HPV16 E6 and HPV6 E6 to p53, although both proteins were different in their transforming potential. Of all four proteins investigated, only HPV16 E6 was able to bind to p53 and E6AP and to induce degradation of the p53 protein in the reticulocyte system. When we investigated in frame deletion mutants of the E6 protein of HPV16 for their abilities to bind to p53 or E6AP, degradate, and inhibit the transactivation function of p53 and to transform rodent fibroblasts, no correlation between the different activities could be found. Mutants still able to bind p53 and E6AP lacked transforming ability and other mutants that were transformation-competent were deficient in p53 and E6AP binding

    Application of thermodynamic calculations in the research of cast irons structure

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    The contribution summarises the results of application of thermodynamic calculation obtained from oxygen activities measurements in cast irons with various type of graphite microstructure. The results were used to find the relationship between natural logarithm of oxygen activities and reverse value of thermodynamic temperature 1/T.From obtained regression line the calculation of oxygen activities value for significant temperature of molten metal was achieved. Each material has its proper typical oxygen activities range for analysing and controlling graphite quality. Practical implication was successfully tested in a Czech foundry producing centrifugally poured cast iron rolls designed for hot strip mills with spheroidal graphite iron core

    A Comparison of Measured and Self-Reported Blood Pressure Status among Low-Income Housing Residents in New York City

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    Self-report is widely used to measure hypertension prevalence in population-based studies, but there is little research comparing self-report with measured blood pressure among low-income populations. The objective of this study was to compare self-reported and measured blood pressure status among a sample of low-income housing residents in New York City (n=118). We completed a cross-sectional analysis comparing self-report with measured blood pressure status. We determined the sensitivity, specificity, and positive predictive value (PPV) of each self-report metric. Of the sample, 68.1% was Black, 71.1% had a household income under $25,000/year, and 28.5% did not complete high school. In our study, there was a discrepancy in the prevalence hypertension by self-report (30.5%) versus measurement (39.8%). PPV of self-report was 94.4%. Specificity was 97.2%. Hypertension awareness (sensitivity) was 72.3%. Of individuals not reporting hypertension, 15.9% had measurements in the hypertensive range and 43.9% had measurements in the borderline hypertensive range. Our findings suggest that self-reported and objective measures of hypertension are incongruent among low-income housing residents and may have important implications for population-based research among low-income populations

    Effects of Refrigerant-Lubricant Combinations on the Energy Efficiency of a Convertible Split-System Residential Air-Conditioner

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    Polyol ester (POE) lubricants of different viscosity ISO grades (32-80) and possessing distinctly different compatibilities (miscible vs. immiscible) were tested with R-410A, R-32, and L-41b. For each refrigerant-lubricant pair tested, the cooling coefficient of performance (COP), heating performance factor (HPF), and oil circulation ratio (OCR) were determined while operating at AHRI Standard 210/240 conditions A, B, C, H1 & H2. The results were correlated to the properties of the working fluids. Due to its higher density, yet comparable specific heat, R-32 showed increased cooling capacity compared to R-410A. However, the COPs of these refrigerants were similar because the capacity increase was offset by increased compressor power consumption. L-41b required the least compressor power, but also had the lowest cooling capacity and COP of the three refrigerants. Lubricant choice had minimal impact on cooling capacity. However, immiscible lubricants lowered cooling capacity by about 4% for R-32, condition B. A larger effect was observed in the compressor, where lubricants specifically designed for R-32 lowered discharge temperatures by 6 °C and reduced power consumption by up to 10%. For R-32-lubricant pairs tested under AHRI cooling condition B, the highest and lowest COPs measured were 4.19 (optimized ISO 68 POE) and 3.72 (commercial ISO 32 POE) ? a 12% improvement by replacing the standard R-410A lubricant

    Area Characteristics and Consumer Nutrition Environments in Restaurants: an Examination of Hispanic Caribbean Restaurants in New York City

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    Hispanics in the USA, particularly those of Caribbean descent, experience high levels of diet-related diseases and dietary risk factors. Restaurants are an increasingly important yet understudied source of food and may present opportunities to positively influence urban food environments. We sought to explore food environments further, by examining the association between neighborhood characteristics and restaurant consumer nutrition environments within New York City’s Hispanic Caribbean (HC) restaurant environments. We applied an adapted version of the Nutrition Environment Measurements Survey for Restaurants (NEMS-R) to evaluate a random sample of HC restaurants (n=89). NEMS-HCR scores (continuous and categorized as low, medium, and high based on data distribution) were examined against area sociodemographic characteristics using bivariate and logistic regression analysis. HC restaurants located in Hispanic geographic enclaves had a higher proportion of fried menu items (p6), compared with their medium (aOR: 6.6, 95% CI: 1.8–24.6) and large counterparts (aOR: 5.6, 95% CI: 1.5–21.4). This research is the first to examine the association between restaurant location and consumer nutrition environments, providing information to contribute to future interventions and policies seeking to improve urban food environments in communities disproportionately affected by diet-related conditions, as in the case of HC communities in New York City

    Facilitating Healthier Eating at Restaurants: A Multidisciplinary Scoping Review Comparing Strategies, Barriers, Motivators, and Outcomes by Restaurant Type and Initiator

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    Restaurants are understudied yet increasingly important food environment institutions for tackling diet-related diseases. This scoping review analyzes research and gray literature (n = 171 records) to assess which healthy eating promotion strategies have been implemented in restaurants and the associated motivations, barriers, and outcomes, compared by restaurant type (corporate/chain vs. independently owned restaurants) and initiator (restaurant-initiated vs. investigator-initiated). We found that the most commonly reported strategy was the increase of generally healthy offerings and the promotion of such offerings. Changes in food availability were more common among corporate restaurants and initiated by restaurants, while environmental facilitators were more commonly initiated by investigators and associated with independently owned restaurants. Aside from those associated with revenue, motivations and barriers for healthy eating promoting strategies varied by restaurant type. While corporate restaurants were also motivated by public health criticism, inde- pendently owned restaurants were motivated by interests to improve community health. Revenue concerns were followed by food sourcing issues in corporate restaurants and lack of interest among independently owned restaurants. Among reporting sources, most outcomes were revenue positive. This study shows the need for practice-based evidence and accounting for restaurant business models to tailor interventions and policies for sustained positive changes in these establishments

    Facilitating Healthy Eating in Latin American Restaurants: Examining Acceptability and Barriers Among Restaurant Owners and Staff

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    Objectives: Examine the acceptability and potential barriers for the implementation of healthy eating promoting (HEP) strategies in independently-owned Latin American restaurants (LAR), including the influence of the COVID-19 pandemic

    Active Mg Estimation Using Thermal Analysis: A Rapid Method to Control Nodularity in Ductile Cast Iron Production

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    Appropriate nodularity in ductile iron castings is strongly associated with the presence of high enough not combined Mg dissolved in the melt to cast. However, the residual Mg which is commonly measured for production control accounts for both dissolved Mg and Mg combined as oxides and sulfides. To account for the uncertainties associated with such a control, it is quite usual to over treat the melt with the risk of porosity appearance. A new methodology based on thermal analysis has been developed in the present work so as to estimate the amount of free Mg dissolved in the melt ready for pouring. A combination of Te mixture and a new “reactive mixture” composed of sulfur plus a commercial inoculant has been prepared for this purpose. This reactive mixture is able to transform the magnesium remaining dissolved in the melt to combined forms of this element. Experiments performed both during start of production (when Mg overtreatment is usual) and during normal mass production indicate that important variations of free Mg occur without relevant changes in residual Mg content as determined by spectrometry. The method developed in the present work has shown to be highly effective to detect those melt batches where active Mg content is not high enough for guaranteeing a correct nodularity of castings. Selection of proper active Mg thresholds and a correct inoculation process are critical to avoid “false”-negative results when using this new method

    Promoting healthy eating in Latin American restaurants: a qualitative survey of views held by owners and staff

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    Background Restaurants, particularly independently-owned ones that serve immigrant communities, are important community institutions in the promotion of dietary health. Yet, these restaurants remain under-researched, preventing meaningful collaborations with the public health sector for healthier community food environments. This research aimed to examine levels of acceptability of healthy eating promotion strategies (HEPS) in independently-owned Latin American restaurants (LARs) and identify resource needs for implementing HEPS in LARs. Methods We completed semi-structured, online discussions with LAR owners and staff (n = 20), predominantly from New York City (NYC), to examine current engagement, acceptability, potential barriers, and resource needs for the implementation of HEPS. Verbatim transcripts were analyzed independently by two coders using Dedoose, applying sentiment weighting to denote levels of acceptability for identified HEPS (1 = low, 2 = medium/neutral, 3 = high). Content analysis was used to examine factors associated with HEPS levels of acceptability and resource needs, including the influence of the Coronavirus pandemic (COVID-19). Results The most acceptable HEPS was menu highlights of healthier items (mean rating = 2.8), followed by promotion of healthier items (mean rating = 2.7), increasing healthy offerings (mean rating = 2.6), nutrition information on the menu (mean rating = 2.3), and reduced portions (mean rating = 1.7). Acceptability was associated with factors related to perceived demand, revenue, and logistical constraints. COVID-19 had a mixed influence on HEPS engagement and acceptability. Identified resource needs to engage in HEPS included nutrition knowledge, additional expertise (e.g., design, social media, culinary skills), and assistance with food suppliers and other restaurant operational logistics. Respondents also identified potential policy incentives. Conclusions LARs can positively influence eating behaviors but doing so requires balancing public health goals and business profitability. LARs also faced various constraints that require different levels of assistance and resources, underscoring the need for innovative engagement approaches, including incentives, to promote these changes
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