190 research outputs found

    Microfluidic-assisted ZIF-silk-polydopamine nanoparticles as promising drug carriers for breast cancer therapy

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    Metal–organic frameworks (MOFs) are heralded as potential nanoplatforms for biomedical applications. Zeolitic imidazolate framework-8 (ZIF-8), as one of the most well known MOFs, has been widely applied as a drug delivery carrier for cancer therapy. However, the application of ZIF-8 nanoparticles as a therapeutic agent has been hindered by the challenge of how to control the release behaviour of anti-cancer zinc ions to cancer cells. In this paper, we designed microfluidic-assisted core-shell ZIF-8 nanoparticles modified with silk fibroin (SF) and polydopamine (PDA) for sustained release of zinc ions and curcumin (CUR) and tested these in vitro in various human breast cancer cells. We report that microfluidic rapid mixing is an efficient method to precisely control the proportion of ZIF-8, SF, PDA, and CUR in the nanoparticles by simply adjusting total flow rates (from 1 to 50 mL/min) and flow rate ratios. Owing to sufficient and rapid mixing during microfluidic-assisted nanoprecipitation, our designer CUR@ZIF-SF-PDA nanoparticles had a desired particle size of 170 nm with a narrow size distribution (PDI: 0.08), which is much smaller than nanoparticles produced using traditional magnetic stirrer mixing method (over 1000 nm). Moreover, a properly coated SF layer successfully enhanced the capability of ZIF-8 as a reservoir of zinc ions. Meanwhile, the self-etching reaction between ZIF-8 and PDA naturally induced a pH-responsive release of zinc ions and CUR to a therapeutic level in the MDA-MB-231, SK-BR-3, and MCF-7 breast cancer cell lines, resulting in a high cellular uptake efficiency, cytotoxicity, and cell cycle arrest. More importantly, the high biocompatibility of designed CUR@ZIF-SF-PDA nanoparticles remained low in cytotoxicity on AD-293 non-cancer cells. We demonstrate the potential of prepared CUR@ZIF-SF-PDA nanoparticles as promising carriers for the controlled release of CUR and zinc ions in breast cancer therapy

    A cost effectiveness analysis of salt reduction policies to reduce coronary heart disease in four Eastern Mediterranean countries.

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    BACKGROUND: Coronary Heart Disease (CHD) is rising in middle income countries. Population based strategies to reduce specific CHD risk factors have an important role to play in reducing overall CHD mortality. Reducing dietary salt consumption is a potentially cost-effective way to reduce CHD events. This paper presents an economic evaluation of population based salt reduction policies in Tunisia, Syria, Palestine and Turkey. METHODS AND FINDINGS: Three policies to reduce dietary salt intake were evaluated: a health promotion campaign, labelling of food packaging and mandatory reformulation of salt content in processed food. These were evaluated separately and in combination. Estimates of the effectiveness of salt reduction on blood pressure were based on a literature review. The reduction in mortality was estimated using the IMPACT CHD model specific to that country. Cumulative population health effects were quantified as life years gained (LYG) over a 10 year time frame. The costs of each policy were estimated using evidence from comparable policies and expert opinion including public sector costs and costs to the food industry. Health care costs associated with CHDs were estimated using standardized unit costs. The total cost of implementing each policy was compared against the current baseline (no policy). All costs were calculated using 2010 PPP exchange rates. In all four countries most policies were cost saving compared with the baseline. The combination of all three policies (reducing salt consumption by 30%) resulted in estimated cost savings of 235,000,000and6455LYGinTunisia;235,000,000 and 6455 LYG in Tunisia; 39,000,000 and 31674 LYG in Syria; 6,000,000and2682LYGinPalestineand6,000,000 and 2682 LYG in Palestine and 1,3000,000,000 and 378439 LYG in Turkey. CONCLUSION: Decreasing dietary salt intake will reduce coronary heart disease deaths in the four countries. A comprehensive strategy of health education and food industry actions to label and reduce salt content would save both money and lives

    Neural correlates of verbal joint action:ERPs reveal common perception and action systems in a shared-Stroop task

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    Recent social-cognitive research suggests that the anticipation of co-actors' actions influences people's mental representations. However, the precise nature of such representations is still unclear. In this study we investigated verbal joint representations in a delayed Stroop paradigm, where each participant responded to one color after a short delay. Participants either performed the task as a single actor (single-action, Experiment 1), or they performed it together (joint-action, Experiment 2). We investigated effects of co-actors' actions on the ERP components associated with perceptual conflict (Go N2) and response selection (P3b). Compared to single-action, joint-action reduced the N2 amplitude congruency effect when participants had to respond (Go trials), indicating that representing a co-actor's utterance helped to dissociate action codes and attenuated perceptual conflict for the responding participant. Yet, on NoGo trials the centro-parietal P3 (P3b) component amplitude increased for joint-action, suggesting that participants mapped the stimuli onto the co-actor's upcoming response as if it were their own response. We conclude that people represent others' utterances similarly to the way they represent their own utterances, and that shared perception-action codes for self and others can sometimes reduce, rather than enhance, perceptual conflict

    Ti alloy with enhanced machinability in UAT turning

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    Metastable β-titanium alloys such as Ti 15V 3Al 3Cr 3Sn are of great technological interest thanks to their high fatigue strength-to-density ratio. However, their high hardness and poor machinability increase machining costs. Additionally, formation of undesirable long chips increases the machining time. To address those issues, a metastable β-titanium alloy (Ti 15V 3Al 3Cr 2Zr 0.9La) with enhanced machinability was developed to produce short chips even at low cutting speeds. A hybrid ultrasonically assisted machining technique, known to reduce cutting forces, was employed in this study. Cutting force components and surface quality of the finished work-pieces were analyzed for a range of cutting speeds in comparison with those for more traditional Ti 15V 3Al 3Cr 3Sn. The novel alloy demonstrated slightly improved machining characteristics at higher cutting speeds and is now ready for industrial applications

    Competition and moral behavior: A meta-analysis of forty-five crowd-sourced experimental designs

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    Does competition affect moral behavior? This fundamental question has been debated among leading scholars for centuries, and more recently, it has been tested in experimental studies yielding a body of rather inconclusive empirical evidence. A potential source of ambivalent empirical results on the same hypothesis is design heterogeneity—variation in true effect sizes across various reasonable experimental research protocols. To provide further evidence on whether competition affects moral behavior and to examine whether the generalizability of a single experimental study is jeopardized by design heterogeneity, we invited independent research teams to contribute experimental designs to a crowd-sourced project. In a large-scale online data collection, 18,123 experimental participants were randomly allocated to 45 randomly selected experimental designs out of 95 submitted designs. We find a small adverse effect of competition on moral behavior in a meta-analysis of the pooled data. The crowd-sourced design of our study allows for a clean identification and estimation of the variation in effect sizes above and beyond what could be expected due to sampling variance. We find substantial design heterogeneity—estimated to be about 1.6 times as large as the average standard error of effect size estimates of the 45 research designs—indicating that the informativeness and generalizability of results based on a single experimental design are limited. Drawing strong conclusions about the underlying hypotheses in the presence of substantive design heterogeneity requires moving toward much larger data collections on various experimental designs testing the same hypothesis

    Evaluation of the psychometric properties of the SF-36 health survey for use among Turkish and Moroccan ethnic minority populations in the Netherlands

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    Purpose: To evaluate the psychometrics of the SF-36 Health Survey among Turkish and Moroccan ethnic minority populations in the Netherlands and to compare the results to those based on the indigenous Dutch population. Methods: Data were derived from the Second Dutch National Survey of General Practice. In total, SF-36 data were available for 409 Turkish, 377 Moroccan, and 9,628 Dutch respondents. Language subgroup analyses were performed for the Turkish (n = 162) and Moroccan-Arabic (n = 52) versions of the SF-36. Psychometric properties were evaluated by descriptive statistics, factor analysis, internal consistency estimates, known-group comparisons, and differential item function (DIF) analysis. Results Low levels of missing SF-36 data were observed across all groups. Confirmatory factor analysis supported the hypothesized SF-36 scale structure for the Dutch and Turkish group, but high correlations between the MH and VT factors were observed in the Moroccan group. All Cronbach’s alpha coefficients were above 0.70, except for the Vitality scale in the Moroccan group and the Vitality and Social Functioning scales in the Moroccan-Arabic language subgroup. Known-groups validity was found across samples using age, sex, education, and comorbidity as grouping variables, but not marital status. Some evidence for DIF was found in both ethnic group samples. Conclusions: The results generally support the use of the SF-36 for general population research among Turkish and Moroccan ethnic minorities in the Netherlands. Additional studies are needed to confirm the psychometrics of the questionnaire when used among these populations in other Western European countries. (aut. ref.

    Normative data and discriminative properties of short form 36 (SF-36) in Turkish urban population

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    BACKGROUND: SF-36 has been both translated into different languages and adapted to different cultures to obtain comparable data on health status internationally. However there have been only a limited number of studies focused on the discriminative ability of SF-36 regarding social and disease status in developing countries. The aim of this study was to obtain population norms of the short form 36 (SF-36) health survey and the association of SF-36 domains with demographic and socioeconomic variables in an urban population in Turkey. METHODS: A cross-sectional study. Face to face interviews were carried out with a sample of households. The sample was systematically selected from two urban Health Districts in Izmir, Turkey. The study group consisted of 1,279 people selected from a study population of 46,290 people aged 18 and over. RESULTS: Internal consistencies of the scales were high, with the exception of mental health and vitality. Physical health scales were associated with both age and gender. On the other hand, mental health scales were less strongly associated with age and gender. Women reported poorer health compared to men in general. Social risk factors (employment status, lower education and economic strain) were associated with worse health profiles. The SF-36 was found to be capable of discriminating disease status. CONCLUSION: Our findings, cautiously generalisable to urban population, suggest that the SF-36 can be a valuable tool for studies on health outcomes in Turkish population. SF-36 may also be a promising measure for research on health inequalities in Turkey and other developing countries

    An Urban Neo-Poverty Population-Based Quality of Life and Related Social Characteristics Investigation from Northeast China

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    OBJECTIVE: To investigate quality of life (QOL) and related characteristics among an urban neo-poverty population in northeast China, and to compare this population with a traditional poverty cohort. DESIGN: The research was a cross-sectional survey executed from June 2005 to October 2007, with a sample of 2940 individuals ages 36 to 55 in three different industrial cities of northeast China. Data were collected on QOL status and sociodemographic characteristics. QOL was assessed using the 36-item Short Form Health Survey (Chinese version). Multiple regression analysis was employed to analyze association between sociodemographic variables and QOL. RESULTS: The scores for QOL in the neo-poverty group were higher than those in the traditional poverty group, but lower than those in the general population. When the neo-poverty population was divided into two subgroups by age, 36-45 years and 46-55 years, the differences in QOL scores were not significant. However, there were significant differences in several dimensions between two subgroups according to unemployment time (<5 years and >5 years). Additionally, stepwise regression analysis indicated that disease burden, including disease and medical expenditures, was a common risk factor for declining QOL in the neo-poverty group. CONCLUSIONS: Despite some limitations, this study provides initial evidence that the QOL of the urban neo-poverty population lies between that of the general population and traditional poverty. QOL of the neo-poverty group approached QOL of the traditional poverty group with increased unemployment years. In addition to decreased income, disease burden is the most important factor influencing QOL status in urban neo-poverty

    Organ preservation surgery for laryngeal cancer

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    The principles of management of the laryngeal cancer have evolved over the recent past with emphasis on organ preservation. These developments have paralleled technological advancements as well as refinement in the surgical technique. The surgeons are able to maintain physiological functions of larynx namely speech, respiration and swallowing without compromising the loco-regional control of cancer in comparison to the more radical treatment modalities. A large number of organ preservation surgeries are available to the surgeon; however, careful assessment of the stage of the cancer and selection of the patient is paramount to a successful outcome. A comprehensive review of various organ preservation techniques in vogue for the management of laryngeal cancer is presented

    Scratching the surface: Elastic rotations beneath nanoscratch and nanoindentation tests

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    In this paper, we investigate the residual deformation field in the vicinity of nanoscratch tests using two orientations of a Berkovich tip on an (001) Cu single crystal. We compare the deformation with that from indentation, in an attempt to understand the mechanisms of deformation in tangential sliding. The lattice rotation fields are mapped experimentally using high-resolution electron backscatter diffraction (HR-EBSD) on cross-sections prepared using focused ion beam (FIB). A physically-based crystal plasticity finite element model (CPFEM) is used to simulate the lattice rotation fields, and provide insight into the 3D rotation field surrounding a nano-scratch experiment, as it transitions from an initial static indentation to a steady-state scratch. The CPFEM simulations capture the experimental rotation fields with good fidelity, and show how the rotations about the scratch direction are reversed as the indenter moves away from the initial indentation
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