Photoelectrochemical Water Splitting for Hydrogen Production Using III-V Semiconductor Materials

The use of photoelectrochemical (PEC) water splitting to harvest intermittent solar sources in the form of hydrogen is an attractive potential method to address energy and environmental issues. Since 1972, when Honda and Fujishima demonstrated the use of titanium dioxide (TiO2) in PEC water splitting (1), extensive efforts have been devoted to the development of photoelectrode stability and high solar-to-hydrogen efficiency. Metal oxides (e.g. TiO2, Fe2O3, BiVO4, and SrTiO2) have been extensively studied but their large band gap and sluggish charge transfer kinetics typically limited their solar-to-hydrogen conversion efficiency (1-9). III-V semiconductor materials have proven attractive for PEC water splitting due to their high efficiency, optimal band gap, and excellent optical properties but they are readily susceptible to corrosion in strongly acidic or basic aqueous solutions during the PEC process (10-18). This thesis aims to construct a PEC device (e.g. photoanode and photocathode) based on III-V semiconductor materials (such as InGaN, GaP, and GaPSb) for PEC water splitting. The design of a direct PEC water splitting device requires a suitable band gap to cover the entire solar spectrum (visible range), which leads to a high photocurrent and solar-to-hydrogen (STH) efficiency. The band edge alignment must straddle the hydrogen and oxygen redox potentials and stable under illumination in electrolyte conditions (19). However, the current challenge is to develop efficient and stable solar-to-chemical conversion systems based on III-V semiconductor materials for PEC water splitting. This can be addressed by incorporating novel co-catalysts that are physically and electrically attached to the surface of the photoelectrodes. The role of the co-catalyst is to minimize the overpotentials and accelerate the charge kinetics at the semiconductor/electrolyte interface (20). Additionally, the surface modification strategy of applying co-catalysts can extend the stability of the photoelectrode for long-time operation (21-25)

Quantitative ultrasound image analysis of the gastrocnemius muscle for injury evaluation (a pilot study)

The aim of this study is to develop a non-invasive method based on quantitative ultrasound image analysis for the evaluation of muscle injury. The method needs to be sufficiently sensitive to detect possible changes in the muscle in order to monitor muscle injury repair and assist in gauging efficacy of treatment modalities. The gastrocnemius muscle was used to develop the method as this muscle constitutes a typical site for muscle injury. A three dimensional ultrasound sweep was performed on the gastrocnemius muscle of 25 healthy subjects and 5 patients with injured muscle using a 3D linear array transducer. Four slices were extracted from the 3D data set from the middle part of the muscle at different sites. Texture parameters include gray level, variance, skewness, kurtosis, co-occurrence matrix; run length matrix, gradient, autoregressive (AR) model and wavelet transform were extracted from the images. The coefficient of variation (CV) and intra-class correlation coefficient (ICC) were calculated for each texture parameter and used to test repeatability and reproducibility. The effect of varying the gain and the dynamic range setting on the texture features were also investigated. Four texture parameters were then used to obtain a reference set for normal gastrocnemius muscle. The four parameters were tested to ensure that there was no effect from the varying depth or size of ROI. These parameters were then tested against abnormal muscle. The texture parameters AR model and gradient were found to be the most sensitive parameters for differentiating healthy muscle from injured muscle and may be used as a tool to monitor the healing process

Dichalcogenide and Metal Oxide Semiconductor-Based Composite to Support Plasmonic Catalysis

Nanocomposites comprising plasmon active metal nanostructures and semiconductors have been used to control the charge states in the metal to support catalytic activity. In this context dichalcogenides when combined with metal oxides offer the potential to control charge states in plasmonic nanomaterials. Using a model plasmonic mediated oxidation reaction p-amino thiophenol ↔ p-nitrophenol, we show that through the introduction of transition metal dichalcogenide nanomaterial, reaction outcomes can be influenced, achieved through controlling the occurrence of the reaction intermediate dimercaptoazobenzene by opening new electron transfer routes in a semiconductor-plasmonic system. This study demonstrates the ability to control plasmonic reactions by carefully controlling the choice of semiconductors.Saudi Arabian government scholarship programMinistry of Education Kingdom of Saudi ArabiaSaudi Arabian Cultural Missio

Age-Related EMG Responses Of The Biceps Brachii Muscle Of Young Adults

Although the effect of an Electromyographic (EMG) signal on the Biceps Brachii (BB) muscle is at the forefront of human movement analysis,there is limited information regarding the importance of the differences in the age-related EMG responses during contraction.The present study aimed to compare the BB muscle activity of three different groups of young adults divided based on age and to find a relationship between surface EMG and endurance time during isometric contraction.The EMG signal was recorded in 30 healthy right-arm-dominant young male subjects during a handgrip force task.The subjects were rationally divided into one of the three age groups (ten in each group):adolescents (‘A’;aged 17.3 ± 1.4 years), vicenarians (‘V’; 24.6 ± 2.1 years),and tricenarians (‘T’; 33.2 ± 1.1 years).The muscle activation during contraction was determined as the root mean square (RMS) EMG signal normalised to the peak RMS EMG signal during a 10-s isometric contraction.The statistical analysis included linear regression to examine the relationship between the EMG amplitude and the endurance time based on five levels of contraction [60%,70%,80%,90% and 100% of the maximal voluntary contraction (MVC)],repeated measures ANOVA to assess differences among the different age groups and the coefficient of variation (CoV) to investigate the steadiness of the EMG activation. The result shows that the early age groups exhibit higher and steadier muscle activity (V: 3.65 ± 0.42 mV,11.46% and A: 3.12 ± 0.29 mV,9.29%) compared with the elderly subjects (T: 2.78 ± 0.33 mV, 11.98%).The most important finding is that the linear slope coefficient for the EMG (amplitude) as a function of time for the muscle of the ‘V’ group (r2=0.591,P0.05) and ‘A’ groups (r2=0.203, P > 0.05).The results obtained in this study can be used to improve the current understanding of the mechanics and muscle functions of the BB muscle of individuals from different age groups during isometric contraction

Photoelectrochemical water oxidation of GaP 1−x Sb x with a direct band gap of 1.65 eV for full spectrum solar energy harvesting

International audienceHydrogen produced using artificial photosynthesis, i.e. solar splitting of water, is a promising energy alternative to fossil fuels. Efficient solar water splitting demands a suitable band gap to absorb near full spectrum solar energy and a photoelectrode that is stable in strongly alkaline or acidic electrolytes. In this work, we demonstrate for the first time, a perfectly relaxed GaP0.67Sb0.33 monocrystalline alloy grown on a silicon substrate with a direct band gap of 1.65 eV by molecular beam epitaxy (MBE) without any evidence of chemical disorder. Under one Sun illumination, the GaP0.67Sb0.33 photoanode with a 20 nm TiO2 protective layer and 8 nm Ni co-catalyst layer shows a photocurrent density of 4.82 mA cm−2 at 1.23 V and an onset potential of 0.35 V versus the reversible hydrogen electrode (RHE) in 1.0 M KOH (pH = 14) aqueous solution. The photoanode yields an incident-photon-to-current efficiency (IPCE) of 67.1% over the visible range between wavelengths 400 nm to 650 nm. Moreover, the GaP0.67Sb0.33 photoanode was stable over 5 h without degradation of the photocurrent under strong alkaline conditions under continuous illumination at 1 V versus RHE. Importantly, the direct integration of the 1.65 eV GaP0.67 Sb0.33 on 1.1 eV silicon may pave the way for an ideal tandem photoelectrochemical system with a theoretical solar to hydrogen efficiency of 27%

Fuzzy Logic-Based Improved Ventilation System For The Pharmaceutical Industry

Indoor air quality in pharmaceutical industry plays a vital role in the production and storing of medicine. Stable indoor environment including favorable temperature,humidity,air flow and number of microorganisms requires consistent monitoring.This paper aimed to develop a fuzzy logic-based intelligent ventilation system to control the indoor air quality in pharmaceutical sites.Specifically,in the proposed fuzzy inference system,the ventilation system can control the air flow and quality in accordance with the indoor temperature,humidity,air flow and microorganisms in the air.The MATLAB® fuzzy logic toolbox was used to simulate the performance of the fuzzy inference system.The results show that the efficiency of the system can be improved by manipulating the input-output parameters according to the user’s demands.Compared with conventional heating, ventilation and air-conditioning (HVAC) systems,the proposed ventilation system has the additional feature of the existence of microorganisms,which is a crucial criterion of indoor air quality in pharmaceutical laboratories

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Comparison of total endoscopic thyroidectomy with conventional open thyroidectomy for treatment of papillary thyroid cancer

BackgroundRecent advance of endoscopic techniques has allowed surgeons to perform thyroidectomy via an incision placement at hidden places which lead to better cosmetic acceptability compared with conventional open thyroidectomy.AimsThis study was conducted to summarize the current evidence that compare open thyroidectomy with endoscopic ‎thyroidectomy in treatment of papillary thyroid cancer‎.‎Methods An electronic literature review, including PubMed, Google Scholar, and EBSCO that examining randomized trials of endoscopic thyroidectomy (ET), conventional open thyroidectomy (COT), and management of papillary thyroid carcinoma was carried out.Results The review included 8 randomized studies that compare total endoscopic thyroidectomy versus conventional open thyroidectomy in treatment of papillary thyroid cancer. The findings showed endoscopic thyroidectomy had statically significant cosmetic appearance, less amount of blood loss and occurrence of transient hypocalcaemia than conventional open thyroidectomy in form of cosmetic outcome, amount lower blood loss.ConclusionThe current review showed that, ET has a better cosmetic outcome and lower blood loss compared with COT. While COT was associated with significantly low operation time, hospital stay, drainage time, amount of drainage fluid and transient recurrent laryngeal nerve (RLN) palsy

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