Development of a Novel Cathodic Plasma/Electrolytic Deposition Technique Part 1: Production of Titanium Dioxide Coatings

A new atmospheric pressure plasma electrolytic deposition process has been developed for the production of crystalline titanium dioxide films on metal substrates. The process occurs in a liquid precursor composed of titanium tetraisopropoxide and absolute ethanol. A plasma discharge is created and confined around the cathode in a superheated vapour sheath surrounded by the liquid phase, inducing the production of a nano-crystalline TiO2 coating at the surface of the cathode. The analysis of the structure and composition of these TiO2 coatings have been carried out by Scanning Electron Microscopy, Transmission Electron Microscopy, Raman and X-Ray Photoelectron Spectroscopies and X-Ray Diffraction. The plasma discharge has been analyzed by emission spectroscopy in order to study its composition and evaluate the electron temperature. The produced crystalline titanium dioxide coatings are very adherent to the substrate and present a dendritic-like structure. We have moreover demonstrated that it is possible to adjust easily its composition by a post-processing calcination. Such characteristics make these films very interesting for photocatalysis, solar cells and gas sensing applications, and promise therefore some useful industrial benefits

Raman Microprobe Analysis of Stucco Samples from the Buildings of Maya Classic Copan

Micro-Raman spectroscopy has been applied to painted stucco samples from three buildings at the Maya site of Copan, Honduras. The buildings, Clavel (AD 450-550), Ani (AD550-650) and Temple 22 (AD730,) date from three phases of the Classic Period (AD400-820) acropolis construction. The red pigment has been identified as hematite and the stucco as a mixture of calcite particles dispersed throughout a calcite based lime wash stucco. The physical structure of the stucco changed through time indicating a refining of production techniques over this period. By combining Micro-Raman spectroscopy with other micro-ATR infrared spectroscopy and environmental scanning electron microscopy a detailed investigation of the materials and production techniques used to decorate these buildings has been made. Differences in the mineralogy of the red pigment used on each building indicate a different geological pigment source for each period

Depression, anxiety, stress and substance use in medical students in a 5-year curriculum

Background. The mental health of medical students is a global concern, and medical training has been described by some as being detrimental to the health of medical students, affecting both their student experience and professional life.Objectives. To determine the prevalence of depression, anxiety, stress and substance use among preclinical students in a 5-year outcomes-based medical curriculum. The study also investigated the association of selected demographic factors with these outcomes.Methods. All University of the Free State medical students in semesters 3 (n=164) and 5 (n=131) during 2015 were included in this cross-sectional study. Depression, anxiety and stress levels were measured by means of the Depression Anxiety Stress Scales (DASS-21). Demographic questions were included in an anonymous self-administered questionnaire. Lifetime and past month substance use were determined.Results. A prevalence of 26.5% for moderate to extremely severe depression, 26.5% for moderate to extremely severe anxiety, and 29.5% for moderate to extremely severe stress was recorded. Female students had significantly higher stress levels, but not increased anxiety. Relationship status and accommodation were not associated with these outcomes. Lifetime use of methylphenidate, lifetime use of alcohol, and past month use of alcohol were associated with depression.Conclusion. The study revealed high levels of depression, anxiety and stress in 2nd- and 3rd-year medical students compared with the general population, but the levels were comparable to those of medical students elsewhere in the world. Past month substance use of alcohol and cannabis was lower than in international studies, but nicotine use was higher

Towards understanding global patterns of antimicrobial use and resistance in neonatal sepsis: Insights from the NeoAMR network

Objective To gain an understanding of the variation in available resources and clinical practices between neonatal units (NNUs) in the low-income and middle-income country (LMIC) setting to inform the design of an observational study on the burden of unit-level antimicrobial resistance (AMR). Design A web-based survey using a REDCap database was circulated to NNUs participating in the Neonatal AMR research network. The survey included questions about NNU funding structure, size, admission rates, access to supportive therapies, empirical antimicrobial guidelines and period prevalence of neonatal blood culture isolates and their resistance patterns. Setting 39 NNUs from 12 countries. Patients Any neonate admitted to one of the participating NNUs. Interventions This was an observational cohort study. Results The number of live births per unit ranged from 513 to 27 700 over the 12-month study period, with the number of neonatal cots ranging from 12 to 110. The proportion of preterm admissions <32 weeks ranged from 0% to 19%, and the majority of units (26/39, 66%) use Essential Medicines List 'Access' antimicrobials as their first-line treatment in neonatal sepsis. Cephalosporin resistance rates in Gram-negative isolates ranged from 26% to 84%, and carbapenem resistance rates ranged from 0% to 81%. Glycopeptide resistance rates among Gram-positive isolates ranged from 0% to 45%. Conclusion AMR is already a significant issue in NNUs worldwide. The apparent burden of AMR in a given NNU in the LMIC setting can be influenced by a range of factors which will vary substantially between NNUs. These variations must be considered when designing interventions to improve neonatal mortality globally. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ