Stability of a strongly anisotropic thin epitaxial film in a wetting interaction with elastic substrate

The linear dispersion relation for longwave surface perturbations, as derived by Levine et al. Phys. Rev. B 75, 205312 (2007) is extended to include a smooth surface energy anisotropy function with a variable anisotropy strength (from weak to strong, such that sharp corners and slightly curved facets occur on the corresponding Wulff shape). Through detailed parametric studies it is shown that a combination of a wetting interaction and strong anisotropy, and even a wetting interaction alone results in complicated linear stability characteristics of strained and unstrained films. PACS: 68.55.J, Morphology of films; 81.15.Aa, Theory and models of film growth; 81.16.Dn, Self-assembly.Comment: Accepted in EPL (http://epljournal.edpsciences.org

Thin-Film Evolution Equation for a Strained Solid Film on a Deformable Substrate: Numerical Steady States

We consider the nonlinear behavior of the thin-film evolution equation for a strained solid film on a substrate. The evolution equation describes morphological changes to the film by surface diffusion in response to elastic energy, surface energy, and wetting energy. Due to the thin-film approximation, the elastic response of the film is determined analytically, resulting in a self-contained evolution equation which does not require separate numerical solution of the full three-dimensional elasticity problem. Using a pseudospectral predictor-corrector method we numerically determine the family of steady state solutions to this evolution equation which correspond to quantum dot and quantum ridge morphologies

Haemoglobin mass and running time trial performance after recombinant human erythropoietin administration in trained men

<p>Recombinant human erythropoietin (rHuEpo) increases haemoglobin mass (Hbmass) and maximal oxygen uptake (v˙ O2 max).</p> <p>Purpose: This study defined the time course of changes in Hbmass, v˙ O2 max as well as running time trial performance following 4 weeks of rHuEpo administration to determine whether the laboratory observations would translate into actual improvements in running performance in the field.</p> <p>Methods: 19 trained men received rHuEpo injections of 50 IUNkg21 body mass every two days for 4 weeks. Hbmass was determined weekly using the optimized carbon monoxide rebreathing method until 4 weeks after administration. v˙ O2 max and 3,000 m time trial performance were measured pre, post administration and at the end of the study.</p> <p>Results: Relative to baseline, running performance significantly improved by ,6% after administration (10:3061:07 min:sec vs. 11:0861:15 min:sec, p,0.001) and remained significantly enhanced by ,3% 4 weeks after administration (10:4661:13 min:sec, p,0.001), while v˙ O2 max was also significantly increased post administration (60.765.8 mLNmin21Nkg21 vs. 56.066.2 mLNmin21Nkg21, p,0.001) and remained significantly increased 4 weeks after rHuEpo (58.065.6 mLNmin21Nkg21, p = 0.021). Hbmass was significantly increased at the end of administration compared to baseline (15.261.5 gNkg21 vs. 12.761.2 gNkg21, p,0.001). The rate of decrease in Hbmass toward baseline values post rHuEpo was similar to that of the increase during administration (20.53 gNkg21Nwk21, 95% confidence interval (CI) (20.68, 20.38) vs. 0.54 gNkg21Nwk21, CI (0.46, 0.63)) but Hbmass was still significantly elevated 4 weeks after administration compared to baseline (13.761.1 gNkg21, p<0.001).</p> <p>Conclusion: Running performance was improved following 4 weeks of rHuEpo and remained elevated 4 weeks after administration compared to baseline. These field performance effects coincided with rHuEpo-induced elevated v˙ O2 max and Hbmass.</p&gt

Delay in initiating tuberculosis treatment and factors associated among pulmonary tuberculosis patients in East Wollega, Western Ethiopia

Background: Delay in treatment is also likely to be associated with a greater number of secondary cases per index case. Objective: to assess the length of patient and health system delays; and identify factors influencing these delays among pulmonary tuberculosis patients. Methods: We conducted a cross-sectional study in 13 selected government health facilities that provide both diagnostic and treatment services using Directly Observed Treatment Short course (DOTS) program. Data were collected from pulmonary TB patients aged 15 years and above during their intensive phase of DOTS treatment using a semi-structured questionnaire. Results: The median total delay was 90 days; with 28 days patient delay and 42 days health system delay. A large proportion (63%) of the overall total delay was contributed by health system delay. Patients from urban areas were 46% more likely to present to health care providers than patients from rural areas, adjusted hazard ratio (AHR) of 1.46 (95% CI: 1.10 - 1.95). Patients from urban areas were 54% more likely to be diagnosed and start treatment earlier than patients from rural areas, AHR of 1.54 (95% CI: 1.15-2.07). Female patients were more delayed to present to health providers than their male counterparts with AHR of 0.63 (95%CI: 0.47–0.84) but had shorter health system delay than male patients with AHR of 1.51 (95% CI: 1.1-22.04). Conclusion: A greater proportion of the overall total delay was contributed by health system delay. The health system should be more accessible for the unmet need. New approaches to make health services more accessible to those in greatest need (rural and women) should be designed and developed.The Ethiopian Journal of Health Development Vol. 21 (2) 2007: pp. 148-15

Metal and metalloid speciation in plants : overview, instrumentation, approaches and commonly assessed elements

The ability of plants to hyper-accumulate metals and metalloids from the surrounding environment may pose a significant health risk to both humans and animals since plants form a substantial component of diet. This attribute, however, has also been identified as a useful tool in bioremediation and biomonitoring studies; where assimilated metal(loid)s in plants often correlate to environmental exposure. Since the bioavailability and toxicity of these elements depends upon their chemical form, speciation studies are essential in determining mobility and metabolic pathways. This can be done in a number of ways where sampling, pre-treatment and storage are all important factors affecting speciation. Appropriate analytical techniques for speciation studies can either be direct methods such as XAS, or indirect methods which require species separation prior to analysis. Separation techniques can be in the form of sequential extractions or column separation and analyte detection often utilises instrumentation such as ESI-MS, ICP-MS and ICP-OES.University of Pretoria and the University of Johannesburg.http://www.journals.elsevier.com/trends-in-analytical-chemistry2017-03-31hb2016Chemistr

Randomised controlled trials on prevention, diagnosis and treatment of diabetes in African countries : a systematic review

Objectives: The epidemiological transition from infectious to chronic diseases leads to novel challenges in African health systems. The prevalence of diabetes mellitus (DM) is increasing dramatically. Undiagnosed and undertreated DM leads to numerous complications including end-organ damage and death. Our objectives were to collect the best locally generated evidence on DM interventions, identify knowledge gaps and determine underexplored research areas. Design: A systematic review and meta-analysis of randomised controlled trials. Participants and setting: African patients in primary, secondary and tertiary prevention, diagnosis and treatment DM type 1 (DM1), type 2 (DM2) and gestational DM (GDM). Outcome: All-cause mortality, glycaemic control, complications, quality of life, hospital admission, treatment adherence and costs. Data sources: Articles published in MEDLINE Ovid, CENTRAL, CINAHL, African Journals Online and African Index Medicus and the International Clinical Trials Registry Platform in English language without time restrictions. The systematic search was last updated in October 2020. Results: Out of 3736 identified publications, we included 60 eligible studies conducted in 15 countries, 75% were conducted in urban healthcare settings, including 10 112 participants. We included 8 studies on DM1, 6 on GDM, 2 on pre-DM, 37 on mainly DM2 including 7 on DM-related complications. The design of the studied intervention was heterogeneous with a focus on educational strategies. The other studies investigated the efficacy of nutritional strategies including food supplementations, pharmacological strategies and strategies to enhance physical activity. Seven studies included interventions on DM-related complications. Conclusions: Research activities increased in recent years, but available evidence is still not representative for all African countries. There is a big lack of evidence in primary healthcare and rural settings, implementation research, pharmacological interventions, especially in poorer countries. Nevertheless, the identified studies offer a variety of effective interventions that can inform medical care and future research

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112