76 research outputs found

    Inexpensive current-voltage system with electronically-controlled resistance under xenon arc light for solar cell efficiency measurements

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    Crystalline silicon solar cell efficiency is required in order to accurately determine its performance and evaluate the fabrication process. Extensive automation has led to development of expensive instrumentation. In this study, simple, inexpensive method for measuring solar cell efficiency is reported. A controllable direct current (dc) illumination intensity method based on low power xenon arc lamps was designed and constructed. Low resistance electrical contacts were formed with conventional front surface probes and back surface Au-plated metal plate with vacuum attachment. In order to measure current-voltage (I-V) response, variable resistance approach was chosen. Commercially available, low cost electronic loads power supply is used to precisely vary resistance while measuring cell voltage and current. The resistance is controllably varied from a short circuit to an open circuit position on the I-V curve while measuring cell voltage and current. Plotting current as a function of voltage generates the characteristic solar cell I-V response. Solar cell efficiency measurements were recorded and plotted using LabVIEW program. The light intensity was varied by increasing number of high intensity discharge (HID) 50 W from 1 to four in order to vary respective illumination intensities from 330 to 1200 W/m2 range. The variation in light intensity was aimed at investigation of the electronic loads power supply at low and high currents. This I-V tester has been applied to different types of solar cell to validate its performance. Solar cells measured as part of this study included commercial silicon solar cell and laboratory solar cells with phosphorus oxytrichloride (POCl3) and phosphoric acid (H3PO4) emitter formation. This I-V measurement system for commercial cell exhibited an efficiency of 15.83% and efficiency of 16.2% and 13.3% for solar cells with POCl3 and H3PO emitters

    Chronic endometritis in cases with recurrent embryo implantation failure

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    Background: Chronic endometritis (CE) is a cause of recurrent implantation failure (RIF) in patients undergoing intracytoplasmic sperm injection (ICSI). CE is diagnosed based on the presence of plasma cell infiltration of the endometrial stroma in endometrial biopsies. Hysteroscopy may be suggestive of CE while the immunohistochemistry with specific cell markers for CD138 cells has been suggested as a more accurate test for the diagnosis of CE.Methods: This study included 110 patients with recurrent ICSI failure (two or more), despite using good-quality embryos. Hysteroscopy and endometrial biopsy were performed as an outpatient procedure. Immunostaining was then performed using a mouse monoclonal CD138 antibody. The prevalence rate of CE was calculated, and the correlation between hysteroscopic findings and immunohistochemical results was assessed. Results: In the included patients in this study there was 32 cases (29%) were diagnosed as CE by hysteroscopy, while 27 cases (24.5%) were positive by CD138 immunohistochemistry (IHC), and 18 cases (16.36%) were positive for CD138 IHC with hysteroscopic features of CE. The presence of more than one abnormal hysteroscopic features was considered positive for CE rather than single abnormal feature, the sensitivity, specificity, positive and negative predictive values of hysteroscopy would be 22.2%, 98.8%, 85.7%, and 79.6%, respectively.Conclusions: The negative diagnostic value of hysteroscopy is high, the combination of the two diagnostic modalities (hysteroscopy and CD138 IHC) will aid in the detection of most cases of CE

    CHEMICAL PROFILE OF TWO JASMINUM SAMBAC L. (AIT) CULTIVARS CULTIVATED IN EGYPT–THEIR MEDIATED SILVER NANOPARTICLES SYNTHESIS AND SELECTIVE CYTOTOXICITY

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    Objective: Evaluation of two Jasminum sambac L. (Ait) cultivars; Arabian Nights (JSA) and Grand Duke of Tuscany (JSG) ethanolic leaves extracts as reducing agents for the green synthesis of silver nanoparticles (AgNPs) and evaluation of their cytotoxicity against MCF-7 breast cancer and 5637 bladder cancer cell lines and chemical profiling of the two cultivars. Methods: The synthesis of silver nanoparticles (AgNPs) by the two cultivars and characterization of AgNPs by ultraviolet (UV)–visible spectroscopy, Transmission electron microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR). Additionally, the use of The high-performance liquid chromatography coupled with photodiode array-mass-mass-spectroscopy (HPLC-PDA-MS/MS) for chemical profiling of both cultivars and evaluation of total leaves extracts and corresponding nanoparticles towards MCF-7 and 5637 cell lines compared to aneuploidy immortal keratinocyte (Ha Cat) normal cells by neutral cell assay. Results: The green synthesized AgNPs (of an average size range of 8.83 and 11.24 nm for JSA and JSG, respectively) exhibited cytotoxicity against MCF-7 and 5637 cell lines. The IC50 was determined for each total extract JSA (15.29±2.16 μg/ml) and JSG (20.28±1.20 μg/ml) and corresponding AgNPs 17.32±2.22 μg/ml and 6.32±1.01μg/ml for JSA and JSG, respectively. The IC50 of JSA and JSG against 5637 bladder cancer cell line were 13.76±1.11 μg/ml and 50.69±3.75 μg/ml, while the corresponding AgNPs showed IC50 of 5.54±0.88 μg/ml and 27.89±2.84 μg/ml, respectively. The HPLC-PDA-MS/MS allowed the identification of 59 compounds; 10 simple phenols, 17 flavonoids; quercetin and kaempferol glycosides, 2 lignans, and 30 secoiridoids; oleuropein, molihauside, and sambacoside. Conclusion: This study proved that JSA is an excellent source for the synthesis of AgNPs with optimum characters and enhanced activities toward MCF-7 and 5637 cell lines in correlation to identified compounds

    Effects of Using Rosemary Residues as a Cereal Substitute in Concentrate on Vitamin E, Antioxidant Activity, Color, Lipid Oxidation, and Fatty Acid Profile of Barbarine Lamb Meat

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    The shortage of some ingredients and, consequently, the continuous increase in the price of feed encourage the search for other alternatives to maintain animal production and enhance its products. In this line, the use of aromatic plant by-products in animal diet has been recently and widely considered, given their richness in bioactive compounds. Therefore, the aim of this study was to investigate the effects of the inclusion of rosemary residues (RR) and protein sources on lamb meat quality. The experiment was carried out on 24 male Barbarine lambs (3 months old) with an average body weight (BW) of 17.8 ± 2.6 kg, which were divided into three homogeneous groups according to BW. The diet comprised 600 g of oat hay and 600 g of concentrate. Three types of concentrate were evaluated: commercial concentrate as the control group (C); rosemary residues (RR) plus soybean meal as the RRS group, and RR plus faba bean as the RRF group. After an experimental period of 65 days, lambs were slaughtered. The inclusion of RR in both concentrates increased the α-tocopherol and total polyphenol content in meat and protected meat against discoloration (high red index and chroma after 9 days of storage) but did not affect meat lipid oxidation, which was similar for all groups. The FA profile was affected by the inclusion of RR, with no effect from the source of protein (faba bean or soybean). The inclusion of RR in the concentrate increased the C18:2 n-6, C18:3n-3, C20:4 n-6, C20:5 n-3, and C22:5 n-3 content (p < 0.05). Consequently, the inclusion of RR also increased the total polyunsaturated FA (p < 0.05) and the ratio of polyunsaturated FA to saturated FA (p < 0.05). The results of this study demonstrate that concentrate based on RR could be useful for lamb meat production by improving the nutritional quality of meat, especially the fatty acid profile. In addition, soybean meal can be replaced by faba bean in lamb concentrate without affecting meat quality.Publishe

    Effect of pulmonary rehabilitation programme including either O2 inhalation or noninvasive ventilation in patients with chronic obstructive pulmonary disease

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    Background: Pulmonary rehabilitation (PR) is crucial in managing chronic obstructive pulmonary disease (COPD) and enhancing functional capacity and health status. Oxygen therapy and noninvasive ventilation (NIV) may be needed to be incorporated into rehabilitation to augment the effectiveness of physical training. Objectives: To compare and assess the impact of the PR programme alone and with augmentation with O2 or NIV on COPD patients. Methods: Seventy-five COPD patients were equally divided into three groups: group 1 patients performed 8 week-PR programme only. Group 2 performed the PR programme while receiving O2. Group 3 completed the PR programme plus NIV. Modified Borg scale, VO2 max, modified Medical Research Council Dyspnea Scale, 6-minute walk test, COPD assessment test score, spirometric measures and arterial blood gases were assessed before and after the programme. Results: The outcome measurements showed meaningful improvement compared with the baseline in the three studied groups. However, VO2 max in group 3 showed higher significant improvement than both groups 1 and 2. Regarding 6-minute walk test, groups 2 and 3 had a higher significant improvement than group 1. COPD assessment test score in group 3 showed higher significant improvement than groups 1 and 2. Arterial blood gases in groups 2 and 3 showed significant increase in partial pressure of arterial oxygen and arterial oxygen saturation, but group 3 only had a significant decrease in PaCO2. Conclusion: O2 supplementation and NIV help severe to very severe COPD patients to perform higher exercise intensity, so they augment the benefits of PR

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

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    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

    Prevalence of trachoma in four marakez of Elmenia and Bani Suef Governorates, Egypt.

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    PURPOSE: In 2015, to determine where interventions are needed to eliminate trachoma as a public health problem from Egypt, we initiated population-based prevalence surveys using the Global Trachoma Mapping Project platform in four suspected-endemic marakez (districts; singular: markaz) of the governorates of Elmenia and Bani Suef. METHODS: In each markaz, 30 households were selected in each of 25 villages. Certified graders examined a total of 3682 children aged 1-9 years in 2993 households, noting the presence or absence of trachomatous inflammation-follicular (TF) and trachomatous inflammation-intense (TI) in each eye. A total of 5582 adults aged ≥15 years living in the same households were examined for trachomatous trichiasis (TT). Household-level access to water and sanitation was recorded. RESULTS: Three of four marakez had age-adjusted TF prevalence estimates in 1-9-year olds of >10%; the other markaz had a TF prevalence estimate of 5-9.9%. Estimates of the age- and gender-adjusted prevalence of unmanaged TT in adults ranged from 0.7% to 2.3%. Household-level access to water and sanitation was high. (We did not, however, measure use of water or sanitation facilities.) Conclusions: Each of the four marakez surveyed has trachoma as a public health problem, with a need for implementation of the SAFE (surgery, antibiotics, facial cleanliness, environmental improvement) strategy. Further mapping is also required to determine the need for interventions in other areas of Egypt

    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

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    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
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