Effects of Antioxidant Supplements on the Survival and Differentiation of Stem Cells

Although physiological levels of reactive oxygen species (ROS) are required to maintain the self-renewal capacity of stem cells, elevated ROS levels can induce chromosomal aberrations, mitochondrial DNA damage, and defective stem cell differentiation. Over the past decade, several studies have shown that antioxidants can not only mitigate oxidative stress and improve stem cell survival but also affect the potency and differentiation of these cells. Further beneficial effects of antioxidants include increasing genomic stability, improving the adhesion of stem cells to culture media, and enabling researchers to manipulate stem cell proliferation by using different doses of antioxidants. These findings can have several clinical implications, such as improving neurogenesis in patients with stroke and neurodegenerative diseases, as well as improving the regeneration of infarcted myocardial tissue and the banking of spermatogonial stem cells. This article reviews the cellular and molecular effects of antioxidant supplementation to cultured or transplanted stem cells and draws up recommendations for further research in this area

Cosm-nutraceutical nanovesicles for acne treatment : physicochemical characterization and exploratory clinical experimentation

The full exploration of the ‘nutraceuticals’ therapeutic potential in cosmetics has been hindered by their poor stratum corneum permeation. Therefore, the aim of the present study was to formulate a nutraceutical; quercetin, in novel vitamin C based nanovesicles (aspasomes), and to explore their beneficial effects in the treatment of acne. Aspasomes were characterized for their particle size, zeta potential, entrapment efficiency (EE%), 3-months storage stability, skin deposition/permeation, antioxidant potential, and morphology. Aspasomes antibacterial efficacy on 'Propionibacterium acnes' using the zone of inhibition assay was also tested, whilst their safety on skin fibroblastic cells was assessed in vitro using 3T3 CCL92 cell lines. An exploratory clinical trial was conducted in acne patients, and the percentage reduction of inflammatory, non-inflammatory and total acne lesions was taken as the evaluation criterion. Results revealed that quercetin-loaded aspasomes displayed a desirable nanometer size (125–184 nm), negative charge with good storage stability, and high skin deposition reaching 40%. Aspasomes managed to preserve the antioxidant activity of quercetin, and exhibited a significantly higher antibacterial effect (15 ± 1.53 mm) against 'Propionibacterium acnes' than quercetin alone (8.25 ± 2.08 mm), and were safe on skin fibroblastic cells. Upon clinical examination in 20 acne patients (14 females, 6 males), quercetin aspasomes exhibited reduction percentages of 77.9%, 11.8% and 55.3% for inflammatory lesions, comedones and total lesions respectively. This opens vast applications of the presented formulation in the treatment of other oxidative skin diseases, and delineates the nutraceuticals and nanoformulations prepared from natural materials as promising dermatological treatment modes

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

ULOGA GRADITELJSKOG NASLEDJA U PLANIRANJU I RAZVOJU EVROCENTRIČNIH URBANIH PODRUČJA U 20. VEKU

The present study is concerned with assessing the currently used methods for improving the skills of continued education in the architectural engineering departments as well as the architectural market in Egypt. The main hypothesis of this study is that: the concept of continued-education in architecture is absent in Egypt, the current mechanisms of supporting continued-education are neither active nor effective, and the architectural education is not enough alone to build a professional architectural character.Survey forms have been distributed for practitioners, and interviews have been conducted with stakeholders for the sake of assessing the role of the universities in Egypt in supporting the graduates’ skills development. The study compared the collected data about these universities through three main points: continued-education, graduates’ follow-up and environment & community services.At the end, this study suggests some mechanisms based on the data analysis of the collected information. These mechanisms will help improving the practice of architecture in Egypt. In addition, the study proposed some recommendations regarding practicing architecture in Egypt for architecture’s practitioners, Egyptian Engineering Syndicate, and Egyptian executive entities such as ministry of higher education & prime minister office. These recommendations will be delivered as well as a copy of this research to all stakeholders in order to be taken into considerations.Ova studija se bavi procenom trenutno korišćenih metoda za poboljšanje veština kontinuiranog obrazovanja na odsecima za arhitektonski inženjering, kao i na arhitektonskom tržištu u Egiptu. Glavna hipoteza ove studije je da: koncept kontinuiranog obrazovanja u arhitekturi nije prisutan u Egiptu, trenutni mehanizmi podrške kontinuiranom obrazovanju nisu ni aktivni ni efikasni, a arhitektonsko obrazovanje nije samo dovoljno za izgradnju profesionalnog arhitektonskog karaktera .Obrasci ankete su distribuirani inženjerima iz prakse, a obavljeni su i intervjui sa zainteresovanim stranama radi procene uloge univerziteta u Egiptu u podršci razvoju veština diplomaca. Studija je uporedila prikupljene podatke o ovim univerzitetima kroz tri glavne tačke: kontinuirano obrazovanje, praćenje diplomaca i usluge zaštite životne sredine i zajednice.Na kraju, ova studija predlaže neke mehanizme zasnovane na analizi podataka prikupljenih informacija. Ovi mehanizmi će pomoći u poboljšanju prakse arhitekture u Egiptu. Pored toga, studija je predložila neke preporuke u vezi sa praktikovanjem arhitekture u Egiptu inženjera arhitekture, Egipatskog inženjerskog sindikata i egipatske izvršne vlasti kao što su Ministarstvo visokog obrazovanja i kancelarija premijera. Ove preporuke će biti dostavljene kao i kopija ovog istraživanja svim zainteresovanim stranama kako bi se uzele u obzir.

2D finite element analysis and force calculations for induction motors with broken bars

AbstractIn this paper an ABC transient model of the three phase induction motor is developed that depends on self- and mutual inductance calculations based on accurate finite element analysis (FEA). This model can represent both healthy and broken bars’ conditions. The effects of that type of fault on the stator current, rotor bar currents distribution, the forces exerted on the rotor bars, the motor speed and motor torque are studied. It was observed that broken bar faults will cause fluctuations in the stator peak current and in the motor speed and torque. It was found that the asymmetry in the rotor bar currents will lead to asymmetrical distribution of the radial and tangential forces affecting the bars. The asymmetry in the tangential forces causes the fluctuations in the motor torque, while the asymmetry in the radial forces will increase the mechanical stresses on the rotor shaft

A novel renewable energy powered zero liquid discharge scheme for RO desalination applications

This work proposes a conceptual model for a Zero Liquid Discharge (ZLD) for Reverse Osmosis (RO) desalination. The model describes a Process Flow Diagram (PFD). The proposed process relies on an RO followed by electrolyser, solar evaporator and mixing tank. The water reject from the RO is split into three fractions, one to an electrolyser to produce H2, another to solar evaporator to produce fresh water, third is remixed with water from the evaporator to reduce the salinity of the RO feed. The hydrogen produced in the electrolyser is burned and its energy is stored using cement blocks. The evaporator is operated using solar energy during the sunny period of the day. Then, the energy stored in cement will replace the solar energy during the remaining hours of the day. The proposed model is based on mass and energy balances including the performance characteristics of individual equipment. A new parameter pZLD is defined as the ratio of the brine reject from the overall plant to the fresh brackish water drawn from the wells. The minimum value of pZLD is zero. The theoretical model is tested for desalination of brackish water with 8000 ppm Total Dissolved Solids (TDS). For a small capacity of 2,000 L/d of fresh water produced, the following results were reported for 400 ppm fresh water: water from well = 2,108 L; produced H2 = 7.40 kg/d; cement required = 2,160 kg for 14 h; solar energy = 5.04 kW for 10 h; pZLD = 5.8%. The cost of modifications to conventional desalination unit is 533,028 Egyptian Pound (EGP), (capital) and 323.49 EGP/h (operating)