39 research outputs found
Water splitting by defects: Insights into multinary transition metal oxides for solar water splitting
With the energy deficiency problem becoming more threatening, the need to find reliable and alternative energy resources is becoming inevitable. Hydrogen gas is considered a good and cleaner alternative due to its green combustion; and it is used in many applications. Accordingly, the use of solar energy in water splitting to produce hydrogen gas is attracting much attention. Finding the optimum semiconducting material that can efficiently absorb sun light and use it in charge carriers’ generation to split water into hydrogen and oxygen is a hot research topic; as many challenges exist in this regard. For instance, wide-bandgap semiconductors have enhanced stability, but absorption limited to the UV region. On the other hand, a lot of the narrow-bandgap semiconductors have poor stability in aqueous electrolytes. In this thesis we explore different effective pathways to overcome the wide band gap problem. In the first part, the fabrication of nanostructured Ti-Nb-Zr MPNTs via simple hard templating anodization method in an electrochemical bath using Formamide-based electrolyte is explained. The formation mechanism and growth model of the MPNTs is discussed using FESEM images. Optical properties are examined using UV-Vis as well as photoelectrochemical properties where the MPNTs have shown 9-fold enhancement in the photocurrent density over the compact counterpart. The MPNTs possess graded refractive index which was confirmed by ellipsometry measurement; and high light scattering owing to their large diameter. In the second part of the thesis, the MPNTs are annealed in three different gases Air, Oxygen and Hydrogen where a 26-fold enhancement was achieved in the H100 compared to Air and O100. XPS, XRD, and Raman scattering suggested the formation of a single mixed oxide under Air and Oxygen atmospheres, while Zr formed a second phase ZrTiO4 under the reducing atmosphere. XPS core spectra confirmed that Hydrogen annealing resulted in formation of valence band tail states and Ti3+ defects. A thorough discussion is presented on the defects present and their contribution to the water splitting process. Finally, CZTS is known to be a narrow-bandgap p-type semiconductor with absorption extending to the visible region. It was synthesized by a solvothermal method, and deposited by electrophoresis on the MPNTs annealed in Hydrogen. Despite of its instability in 1M KOH, a proof of concept was accomplished, as a great photocurrent enhancement was achieved
Brain Signal Analysis while Watching Stereoscopic 3D Movies
An electroencephalogram (EEG) is a test that measures and records the
electrical activity of brain. Special sensors (electrodes ) are attached to the head and
hooked by wires to a computer. EEG measures voltage fluctuations resulting from
ionic current flows within the neurons of the brain. With technology growing every
day, and stereoscopic 3D televisions becoming commercially available, a question
arises: what kind of effect do 3D movies have on the brain activity and brain signals?
The objective of this project is to have an attempt at answering this question as very
little research has been done in this field. An EEG study was conducted on 30 healthy
participants while watching a series of clips in 2D, stereoscopic 3D using active
glasses and stereoscopic 3D using passive glasses. Their brain activity was recorded,
and analyzed by writing a code in MATLAB to compare between the brain signals in
terms of power, coherence and phase. We focused on the activity in theta and beta
frequency bands. This paper shows that the results revealed a decrease in
concentration in stereoscopic 3D compared to 2D, as well as higher learning behavior
in 2D
Brain Signal Analysis while Watching Stereoscopic 3D Movies
An electroencephalogram (EEG) is a test that measures and records the
electrical activity of brain. Special sensors (electrodes ) are attached to the head and
hooked by wires to a computer. EEG measures voltage fluctuations resulting from
ionic current flows within the neurons of the brain. With technology growing every
day, and stereoscopic 3D televisions becoming commercially available, a question
arises: what kind of effect do 3D movies have on the brain activity and brain signals?
The objective of this project is to have an attempt at answering this question as very
little research has been done in this field. An EEG study was conducted on 30 healthy
participants while watching a series of clips in 2D, stereoscopic 3D using active
glasses and stereoscopic 3D using passive glasses. Their brain activity was recorded,
and analyzed by writing a code in MATLAB to compare between the brain signals in
terms of power, coherence and phase. We focused on the activity in theta and beta
frequency bands. This paper shows that the results revealed a decrease in
concentration in stereoscopic 3D compared to 2D, as well as higher learning behavior
in 2D
Corrigendum: Psychometric properties of the arabic version of the problem areas in diabetes scale in primary care
Psychometric Properties of the Arabic Version of the Problem Areas in Diabetes Scale in Primary Care
BackgroundThe Problem Areas in Diabetes (PAID) scale is a reliable and valid tool that is widely used for diabetes-distress screening, but the Arabic version of the scale lacks validity and reliability analysis in primary healthcare (PHC) patients. Our study aimed to evaluate the psychometric properties of the Arabic version of the PAID (AR-PAID) scale among Egyptian patients with type 2 diabetes mellitus (T2DM) in PHC settings.MethodsWe conducted a cross-sectional study on a convenience sample of 200 patients from six rural PHC settings in the Ismailia governorate. The confirmatory factor analysis (CFA) was performed to test the goodness-of-fit to the predefined models of the PAID. Convergent construct was evaluated through correlations with the Arabic versions of the Patient Health Questionnaire 9 (PHQ-9), Generalized Anxiety Disorder Scale (GAD-7), and 5-item World Health Organization Well-Being Index (WHO-5), additionally glycated hemoglobin (HbA1c) levels. Discriminant validity was evaluated through associations with patients' sociodemographic and clinical characteristics. Reliability was evaluated through internal consistency (Cronbach's α) and test-retest reliability analysis (intraclass correlation coefficient, ICC).ResultsThe CFA demonstrated the best fit for a four-factor model. The AR-PAID was significantly correlated with the following measures: PHQ-9 (rho = 0.71, p < 0.001), GAD-7 (rho = 0.50, p < 0.001), WHO-5 (rho = −0.69, p < 0.001), and HbA1c (rho = 0.36, p < 0.001), supporting sound convergent validity. Discriminant validity was satisfactory demonstrated. Internal consistency was excellent (α = 0.96) and test-retest reliability was stable (ICC = 0.97).ConclusionsThe AR-PAID scale is a valid and reliable instrument for diabetes-distress screening in primary care patients with T2DM that can be used in clinical settings and research. Further research is needed to validate short forms of the AR-PAID scale
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
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
An optimization approach for automated unit test generation tools using multi-objective evolutionary algorithms
High code coverage is measured by the process of software testing typically using automatic test case generation tools. This standard approach is usually used for unit testing to improve software reliability. Most automated test case generation tools focused just on code coverage without considering its cost and redundancy between generated test cases. To obtain optimized high code coverage and to ensure minimum cost and redundancy a Multi-Objectives Evolutionary Algorithm approach (MOEA) is set in motion. An efficient approach is proposed and applied to different algorithms from MOEA Frame from the separate library with three fitness functions for Coverage, Cost, and Redundancy. Four MEOA algorithms have been proven reliable to reach above the 90 percent code coverage: NSGAII, Random, SMSEMOA,v and ε-MOEA. These four algorithms are the key factors behind the MOEA approach
Association of interleukin-23 receptor (IL-23R) gene polymorphisms (rs11209026, rs2201841 and rs10889677) with Egyptian rheumatoid arthritis patients
AbstractAim of the workTo analyse interleukin 23 receptors (IL23R) single-nucleotide polymorphism (SNPs) (rs11209026, rs2201841, and rs10889677) and to detect their association with Egyptian rheumatoid arthritis (RA) patients.Patients and methodsThe study included 120 Egyptian RA patients and 120 healthy controls that were genotyped for the three SNPs by real time/polymerase chain reaction for the first SNP and restriction fragment length polymorphism/PCR (RFLP/PCR) in the last two SNPs. The disease activity score (DAS28) was assessed in the patients.ResultsThe studied patients had a mean age of 42.5±13.4years, a disease duration of 5.2±3.5years and consisted of 22 males and 98 females. Joint deformities were present in 35 and 66 patients had swollen joints. The rheumatoid factor (RF) was positive in 78.3% and the DAS28 was 3.2±1.2. Our data emphasize that the AA genotype of rs11209026 was significantly associated with RA patients compared to the controls (p=0.001). We did not find any significant association between either rs2201841 or rs10889677 and the development of RA (p=1, p=0.56 respectively). The AA allele in the 3 SNPs were remarkable frequent in those with deformities and positive RF.ConclusionOur results suggest that IL23 receptor AA genotype variant of rs11209026 contributes to the aetiology of RA and may be considered a genetic marker and shared the susceptibility gene. We need to address the subgroup of patients who will benefit from the selective suppression of the IL-23 signalling which would represent new perspectives towards a personalized therapy of RA patients by further studies