Comparative study of hydrothermal treatment and thermal annealing effects on the properties of electrodeposited micro-columnar ZnO thin films

We report a comparison of the role played by different sample treatments, namely, a low-temperature hydrothermal treatment by hot H2O vapor in an autoclave versus thermal annealing in air on the properties of ZnO films grown by electrochemical deposition (ECD). Scanning electron microscopy studies reveal a homogeneous micro-columnar morphology and changes in the film surface for the two different treatments. It is found that post-growth hydrothermal treatments of ECD ZnO films at 150 °C under an aqueous environment enhance their structural and optical properties (photoluminescence, transmission, Raman spectra, etc.) similar to thermal annealing in air at higher temperatures (> 200 °C). The modifications of the structural and optical properties of ZnO samples after thermal annealing in air in the temperature range of 150–600 °C are discussed. The removal of chlorine from the films by the hydrothermal treatment was evidenced which could be the main reason for the improvement of the film quality. The observation of the enhanced photoluminescence peak at 380 nm demonstrates the superior properties of the hydrothermally treated ZnO films as compared to the films annealed in air ambient at the same or higher temperature. This post-growth hydrothermal treatment would be useful for the realization of high performance optoelectronic devices on flexible supports which might not withstand at high temperature annealing treatments

Tailoring the selectivity of ultralow-power heterojunction gas sensors by noble metal nanoparticle functionalization

Heterojunctions are used in solar cells and optoelectronics applications owing to their excellent electrical and structural properties. Recently, these energy-efficient systems have also been employed as sensors to distinguish between individual gases within mixtures. Through a simple and versatile functionalization approach using noble metal nanoparticles, the sensing properties of heterojunctions can be controlled at the nanoscopic scale. This work reports the nanoparticle surface functionalization of TiO2/CuO/Cu2O mixed oxide heterostructures, where the gas sensing selectivity of the material is tuned to achieve versatile sensors with ultra-low power consumption. Functionalization with Ag or AgPt-nanoclusters (5–15 nm diameter), changed the selectivity from ethanol to butanol vapour, whereas Pd-nanocluster functionalization shifts the selectivity from the alcohols to hydrogen. The fabricated sensors show excellent low power consumption below 1 nW. To gain insight into the selectivity mechanism, density functional theory (DFT) calculations have been carried out to simulate the adsorption of H2, C2H5OH and n-C4H9OH at the noble metal nanoparticle decorated ternary heterostructure interface. These calculations also show a decrease in the work function by ~2.6 eV with respect to the pristine ternary heterojunctions. This work lays the foundation for the production of a highly versatile array of sensors of ultra-low power consumption with applications for the detection of individual gases in a mixture

Optical Absorption and EPR Studies on Enargite

The behaviour of transition metal ions in enargite has been studied by electron paramagnetic resonance and absorption spectroscopy in the UV–VIS and near-IR regions. The ground state of Cu(II) ions in enargite is confirmed as 2B1g since g11>g⊥ (2.54>2.11). Three characteristic bands observed in the optical absorption spectra at 8275, 13105 and 18420 cm−1 are assigned to the transitions, 2B1g→2A1g, 2B1g→2B2 and 2B1g→2Eg, respectively, of Cu(II) ion in the tetragonal field. The presence of Fe(II) bands is an evidence for iron impurities in the mineral

A phase III randomized trial of weight loss to reduce cancer-related fatigue among overweight and obese breast cancer patients: MEDEA Study design

BACKGROUND: Elevated body mass index (BMI) represents a risk factor for cancer-related fatigue (CRF). Weight loss interventions are feasible and safe in cancer survivors, leading to improved cardio-metabolic and quality of life (QOL) outcomes and modulating inflammatory biomarkers. Randomized data are lacking showing that a lifestyle intervention aimed at weight loss, combining improved diet, exercise, and motivational counseling, reduces CRF. Motivating to Exercise and Diet, and Educating to healthy behaviors After breast cancer (MEDEA) is a multi-center, randomized controlled trial evaluating the impact of weight loss on CRF in overweight or obese survivors of breast cancer. Herein, we described the MEDEA methodology. METHODS: Patients (N = 220) with stage I-III breast cancer and BMI ≥ 25 kg/m2, within 12 months of primary treatment, and able to walk ≥ 400 m are eligible to enroll. Participants are randomized 1:1 to health education alone vs. a personalized telephone-based weight loss intervention plus health education. Both arms receive a health education program focusing on healthy living. Patients in the intervention arm are paired with an individual lifestyle coach, who delivers the intervention through 24 semi-structured telephone calls over 1 year. Intervention goals include weight loss ≥ 10% of baseline, caloric restriction of 500-1000 Kcal/day, and increased physical activity (PA) to 150 (initial phase) and 225-300 min/week (maintenance phase). The intervention is based on the social cognitive theory and is adapted from the Breast Cancer Weight Loss trial (BWEL, A011401). The primary endpoint is the difference in self-reported CRF (EORTC QLQ-C30) between arms. Secondary endpoints include the following: QOL (EORTC QLQ-C30, -BR45, -FA12), anxiety, and depression (HADS); weight and BMI, dietary habits and quality, PA, and sleep; health care costs (hospital-admissions, all-drug consumption, sick leaves) and cost-effectiveness (cost per quality-adjusted life-year); and patient motivation and satisfaction. The primary analysis of MEDEA will compare self-reported CRF at 12 months post-randomization between arms, with 80.0% power (two-sided α = 0.05) to detect a standardized effect size of 0.40. DISCUSSION: MEDEA will test the impact of a weight loss intervention on CRF among overweight or obese BC survivors, potentially providing additional management strategies and contributing to establish weight loss support as a new standard of clinical care. TRIAL REGISTRATION: ClinicalTrials.gov NCT04304924. © 2022. The Author(s).Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]