17 research outputs found

    High-resolution transmission electron microscopy investigation of diffusion in metallic glass multilayer films

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    Lack of plasticity is one of the main disadvantages of metallic glasses. One of the solutions to this problem can be composite materials. Diffusion bonding is promising for composite fabrication. In the present work the diffusion process in glassy multilayer films was investigated. A combination of advanced transmission electron microscopy (TEM)methods and precision sputtering techniques allows visualization and study of diffusion in amorphous metallic layers with high resolution. Multilayered films were obtained by radio frequency sputter deposition of Zr-Cu and Zr-Pd. The multilayers were annealed under a high vacuum (10 −5 Pa)for 1 and 5 h at 400 °C, that is, well below the crystallization temperatures but very close to the glass-transition temperatures of both types of the glassy layer. The structural evolution in the deposited films was investigated by high-resolution transmission electron microscopy. It was observed that, despite the big differences in the atomic mass and size, Pd and Cu have similar diffusion coefficients. Surprisingly, 1 h of annealing results in formation of metastable copper nanocrystals in the Zr-Cu layers which, however, disappear after 5 h of annealing. This effect may be connected with nanovoid formation under a complex stress state evolving upon annealing, and is related to the exceptionally slow relaxation of the glassy layers sealed with a Ta overlayer.The authors acknowledge the financial support through the European Research Council under the ERC Advanced Grants INTELHYB (grant ERC-2013-ADG-340025) and ExtendGlass (grant ERC-2015-AdG-695487), the German Science Foundation (DFG) under the grant SO 1518/1-1, and the Ministry of Education and Science of the Russian Federation in the framework of the ‘Increase Competitiveness’ program of NUST ‘MISiS’ (№ К2-2014-013 and К2-2017-089)

    Online Mental Health Resources in Rural Australia: Clinician Perceptions of Acceptability

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    Background: Online mental health resources have been proposed as an innovative means of overcoming barriers to accessing rural mental health services. However, clinicians tend to express lower satisfaction with online mental health resources than do clients. Objective: To understand rural clinicians’ attitudes towards the acceptability of online mental health resources as a treatment option in the rural context. Methods: In-depth interviews were conducted with 21 rural clinicians (general practitioners, psychologists, psychiatrists, and clinical social workers). Interviews were supplemented with rural-specific vignettes, which described clinical scenarios in which referral to online mental health resources might be considered. Symbolic interactionism was used as the theoretical framework for the study, and interview transcripts were thematically analyzed using a constant comparative method.Results: Clinicians were optimistic about the use of online mental health resources into the future, showing a preference for integration alongside existing services, and use as an adjunct rather than an alternative to traditional approaches. Key themes identified included perceptions of resources, clinician factors, client factors, and the rural and remote context. Clinicians favored resources that were user-friendly and could be integrated into their clinical practice. Barriers to use included a lack of time to explore resources, difficulty accessing training in the rural environment, and concerns about the lack of feedback from clients. Social pressure exerted within professional clinical networks contributed to a cautious approach to referring clients to online resources. Conclusions: Successful implementation of online mental health resources in the rural context requires attention to clinician perceptions of acceptability. Promotion of online mental health resources to rural clinicians should include information about resource effectiveness, enable integration with existing services, and provide opportunities for renegotiating the socially defined role of the clinician in the eHealth era

    Uncomplicated Clinical Malaria Features, the Efficacy of Artesunate-Amodiaquine and Their Relation with Multiplicity of Infection in the Democratic Republic of Congo

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    In the Democratic Republic of Congo, artesunate-amodiaquine (ASAQ) is the first-line medication recommended for uncomplicated malaria treatment. We conducted a study in Kinshasa to describe the clinical features of the disease and assess the efficacy of ASAQ and its impact on the multiplicity of infection in children with uncomplicated malaria.Children aged 12 to 59 months with uncomplicated P. falciparum malaria were treated with ASAQ and followed up passively for 42 days. To distinguish new infections from recrudescent parasites, samples were genotyped using a stepwise strategy with three molecular markers (GLURP, MSP2 and MSP1). We then assessed PCR-corrected and -uncorrected day-42 cure rates and multiplicity of infection (MOI).In total, 2,796 patients were screened and 865 enrolled in the study. Clinical features were characterized by history of fever (100%), coryza (59.9%) and weakness (59.4%). The crude and PCR-corrected efficacies of ASAQ were 55.3% (95%CI: 51.8-58.8) and 92.8% (95%CI: 91.0-94.6) respectively, as 83.6% (95%CI: 79.1-87.2) of the recurrences were new infections. Compared to monoclonal infections, polyclonal infections were more frequent at enrollment (88.1%) and in recurrences (80.1%; p = 0.005; OR: 1.8, 95%CI: 1.20-2.8). The median MOI at enrollment (MOI = 3.7; IQR: 0.7-6.7) decreased to 3 (IQR: 1-5) in the recurrent samples (p<0.001). Patients infected with a single haplotype on day 0 had no recrudescence; the risk of recrudescence increased by 28% with each additional haplotype (HR: 1.3, 95%CI: 1.24-1.44).The PCR-corrected efficacy of ASAQ at day 42 was 92.8%, but crude efficacy was relatively poor due to high reinfection rates. Treatment outcomes were positively correlated with MOI. Continued monitoring of the efficacy of ACTs-ASAQ, in this case-is paramount.ClinicalTrials.gov NCT01374581

    Apparent Power Law Scaling of Variable Range Hopping Conduction in Carbonized Polymer Nanofibers

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    We induce dramatic changes in the structure of conducting polymer nanofibers by carbonization at 800°C and compare charge transport properties between carbonized and pristine nanofibers. Despite the profound structural differences, both types of systems display power law dependence of current with voltage and temperature, and all measurements can be scaled into a single universal curve. We analyze our experimental data in the framework of variable range hopping and argue that this mechanism can explain transport properties of pristine polymer nanofibers as well

    Evaluation and Management of Vaginitis

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    OBJECTIVE: To evaluate recent advances in our understanding of the clinical relevance, diagnosis, and treatment of vaginal infections, and to determine an efficient and effective method of evaluating this clinical problem in the outpatient setting. DATA SOURCES: Relevant papers on vaginitis limited to the English language obtained through a MEDLINE search for the years 1985 to 1997 were reviewed. DATA SYNTHESIS: Techniques that enable the identification of the various strains of candida have helped lead to a better understanding of the mechanisms of recurrent candida infection. From this information a rationale for the treatment of recurrent disease can be developed. Bacterial vaginosis has been associated with complications, including upper genital tract infection, preterm delivery, and wound infection. Women undergoing pelvic surgery, procedures in pregnancy, or pregnant women at risk of preterm delivery should be evaluated for bacterial vaginosis to decrease the rate of complications associated with this condition. New, more standardized criteria for the diagnosis of bacterial vaginosis may improve diagnostic consistency among clinicians and comparability of study results. Use of topical therapies in the treatment of bacterial vaginosis are effective and associated with fewer side effects than systemic medication. Trichomonas vaginalis, although decreasing in incidence, has been associated with upper genital tract infection. Therapy of T. vaginalis infection has been complicated by an increasing incidence of resistance to metronidazole. CONCLUSIONS: Vaginitis is a common medical problem in women that is associated with significant morbidity and previously unrecognized complications. Research in recent years has improved diagnostic tools as well as treatment modalities for all forms of vaginitis
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