122 research outputs found

    Electric-field control of a single-atom polar bond

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    The polar covalent bond between a single Au atom terminating the apex of an atomic force microscope tip and a C atom of graphene on SiC(0001) is exposed to an external electric field. For one field orientation the Au-C bond is strong enough to sustain the mechanical load of partially detached graphene, whilst for the opposite orientation the bond breaks easily. Calculations based on density functional theory and nonequilibrium Green's function methods support the experimental observations by unveiling bond forces that reflect the polar character of the bond. Field-induced charge transfer between the atomic orbitals modifies the polarity of the different electronegative reaction partners and the Au-C bond strength

    DRUJ instability after distal radius fracture: A comparison between cases with and without ulnar styloid fracture

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    AbstractBackgroundBecause of the importance of the DRUJ in upper extremity function and the prevalence of distal radius fractures, either with or without ulnar styloid fracture, this study was designed to assess the relationship between ulnar styloid fracture and the incidence of DRUJ instability after treatment of distal radius fractures treated with ORIF (volar plate).Methods112 patients suffering from type two and three distal radius fractures (Fernandez classification), were evaluated. Depending on the presence of ulnar styloid avulsion fracture, patients were divided into two groups: 86 cases with isolated radial fracture and 26 cases with a distal radius fracture accompanied by ulnar styloid fracture. All patients underwent distal radius fracture ORIF. CT scanning was done both immediately after surgery and 3 months post-op. DRUJ stability was examined using the modified radioulnar line method and the incidence of DRUJ instability was compared between the two groups.ResultsImmediate instability was seen in 11 patients. Three of these patients had concomitant ulnar styloid fracture and were excluded for further fixation. Three months later, another 9 cases were diagnosed with DRUJ instability, 2 of whom had concomitant ulnar styloid fracture and the other 7 suffered from isolated distal radius fracture. Chi-square test revealed no significant difference (p < 0.05). There were no cases of delayed union or non-union distal radius fracture.ConclusionOur study demonstrated that untreated stable or minimally displaced ulnar styloid fracture accompanied by distal radius fracture, has no adverse effect on DRUJ stability following ORIF of the radius

    The french maritime pine bark extract reduce metabolic syndrome risk and improve body composition in obesity: A new clinical approach

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    Metabolic syndrome is a cluster of conditions which enhance the risk of metabolic and cardiovascular diseases such as diabetes mellitus, dyslipidemia, or hypertension. Obesity plays a pivotal role in the pathogenesis of metabolic syndrome. French maritime Pine bark extract (PBE) in addition to its antioxidant properties, has protective effects on metabolic syndrome component through several mechanisms. At present, there are few data on the net impact of PBE on metabolic syndrome factors in obesity. This trial report the results of 2-month period supplementation of 38 obese women received weight loss diet and PBE (150mg/day) or placebo. The metabolic syndrome parameters and body composition were assessed at the beginning and end of the study. The results showed PBE has significant protective effects on metabolic syndrome factors including central obesity, TG, HDL, BP and FBS (P<0.05), decrease metabolic syndrome risk in obesity and improve body composition. Thus, The PBE is considered as a new approach to obesity and metabolic syndrome prevention. © 2018 Tehran University of Medical Sciences. All rights reserved

    The impact of polio eradication on routine immunization and primary health care: a mixed-methods study.

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    BACKGROUND: After 2 decades of focused efforts to eradicate polio, the impact of eradication activities on health systems continues to be controversial. This study evaluated the impact of polio eradication activities on routine immunization (RI) and primary healthcare (PHC). METHODS: Quantitative analysis assessed the effects of polio eradication campaigns on RI and maternal healthcare coverage. A systematic qualitative analysis in 7 countries in South Asia and sub-Saharan Africa assessed impacts of polio eradication activities on key health system functions, using data from interviews, participant observation, and document review. RESULTS: Our quantitative analysis did not find compelling evidence of widespread and significant effects of polio eradication campaigns, either positive or negative, on measures of RI and maternal healthcare. Our qualitative analysis revealed context-specific positive impacts of polio eradication activities in many of our case studies, particularly disease surveillance and cold chain strengthening. These impacts were dependent on the initiative of policy makers. Negative impacts, including service interruption and public dissatisfaction, were observed primarily in districts with many campaigns per year. CONCLUSIONS: Polio eradication activities can provide support for RI and PHC, but many opportunities to do so remain missed. Increased commitment to scaling up best practices could lead to significant positive impacts

    Degradation studies of hydrophilic, partially degradable and bioactive cements (HDBCs) incorporating chemically modified starch

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    The degradation rate in Hydrophilic, Degradable and Bioactive Cements (HDBCs) containing starch/cellulose acetate blends (SCA) is still low. In order to increase degradation, higher amounts of starch are required to exceed the percolation threshold. In this work, gelatinization, acetylation and methacrylation of corn starch were performed and assessed as candidates to replace SCA in HDBCs. Formulations containing methacrylated starch were prepared with different molar ratios of 2-hydroxyethyl methacrylate and methyl methacrylate in the liquid component and the amount of residual monomer released into water was evaluated. The concentration of reducing sugars, percentage of weight loss and morphologic analyses after degradation all confirmed increased degradation of HDBC with alpha-amylase, with the appearance of pores and voids from enzymatic action. Methacrylated starch therefore is a better alternative to be used as the solid component of HDBC then SCA, since it leads to the formation of cements with a lower release of toxic monomers and more prone to hydrolytic degradation while keeping the other advantages of HDBCs.The authors acknowledge to Foundation for Science and Technology (FCT), who supported this study through funds from project Concept2Cement (POCTI/CTM/60735/2004)

    Carbohydrate hydrogels with stabilized phage particles for bacterial biosensing: bacterium diffusion studies

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    Bacteriophage particles have been reported as potentially useful in the development of diagnosis tools for pathogenic bacteria as they specifically recognize and lyse bacterial isolates thus confirming the presence of viable cells. One of the most representative microorganisms associated with health care services is the bacterium Pseudomonas aeruginosa, which alone is responsible for nearly 15 % of all nosocomial infections. In this context, structural and functional stabilization of phage particles within biopolymeric hydrogels, aiming at producing cheap (chromogenic) bacterial biosensing devices, has been the goal of a previous research effort. For this, a detailed knowledge of the bacterial diffusion profile into the hydrogel core, where the phage particles lie, is of utmost importance. In the present research effort, the bacterial diffusion process into the biopolymeric hydrogel core was mathematically described and the theoretical simulations duly compared with experimental results, allowing determination of the effective diffusion coefficients of P. aeruginosa in the agar and calcium alginate hydrogels tested.Financial support to Victor M. Balcao, via an Invited Research Scientist fellowship (FAPESP Ref. No. 2011/51077-8) by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Sao Paulo, Brazil), is hereby gratefully acknowledged

    Community-Centered Responses to Ebola in Urban Liberia: The View from Below

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    The West African Ebola epidemic has demonstrated that the existing range of medical and epidemiological responses to emerging disease outbreaks is insufficient, especially in post-conflict contexts with exceedingly poor healthcare infrastructures. This study provides baseline information on community-based epidemic control priorities and identifies innovative local strategies for containing EVD in Liberia.In this study the authors analyzed data from the 2014 Ebola outbreak in Monrovia and Montserrado County, Liberia. The data were collected for the purposes of program design and evaluation by the World Health Organization (WHO) and the Government of Liberia (GOL), in order to identify: (1) local knowledge about EVD, (2) local responses to the outbreak, and (3) community based innovations to contain the virus. At the time of data collection, the international Ebola response had little insight into how much local Liberian communities knew about Ebola, and how communities managed the epidemic when they could not get access to care due to widespread hospital and clinic closures. Methods included 15 focus group discussions with community leaders from areas with active Ebola cases. Participants were asked about best practices and what they were currently doing to manage EVD in their respective communities, with the goal of developing conceptual models of local responses informed by local narratives. Findings reveal that communities responded to the outbreak in numerous ways that both supported and discouraged formal efforts to contain the spread of the disease. This research will inform global health policy for both this, and future, epidemic and pandemic responses

    Original article title: "Comparison of therapeutic efficacy of topical corticosteroid and oral zinc sulfate-topical corticosteroid combination in the treatment of vitiligo patients: a clinical trial"

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    <p>Abstract</p> <p>Background</p> <p>Vitiligo is the most prevalent pigmentary disorder which occurs worldwide, with an incidence rate between 0.1-4 percent. It is anticipated that the discovery of biological pathways of vitiligo pathogenesis will provide novel therapeutic and prophylactic targets for future approaches to the treatment and prevention of vitiligo. The purposes of this study were evaluating the efficacy of supplemental zinc on the treatment of vitiligo.</p> <p>Methods</p> <p>This randomized clinical trial was conducted for a period of one year. Thirty five patients among 86 participants were eligible to entrance to the study. The patients in two equal randomized groups took topical corticosteroid and combination of oral zinc sulfate-topical corticosteroid.</p> <p>Results</p> <p>The mean of responses in the corticosteroid group and the zinc sulfate-corticosteroid combination group were 21.43% and 24.7%, respectively.</p> <p>Conclusion</p> <p>Although, the response to corticosteroid plus zinc sulfate was more than corticosteroid, there was no statistically significant difference between them. It appeared that more robust long-term randomized controlled trials on more patients, maybe with higher doses of zinc sulfate, are needed to fully establish the efficacy of oral zinc in management of vitiligo.</p> <p>Trial Registration</p> <p>chiCTRTRC10000930</p
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