96 research outputs found

    Energy Efficient Buildings in Smart Cities: Biomimicry Approach

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    Smart cities are those using technologies to make life easier for their citizens and enhancing the quality of life and urban service in order to reduce consumption, especially of energy. Biomimicry is one of the tools of the 21st century toachieve an emotional smart city that has its own spirit and identity. Biomimicryhas three main levels: organism, behaviour and ecosystem level, in terms of form generation, material selection,construction process, and function establishing.A subcategory of biomimicry is building skin which forms the entire exterior envelope of the building. It is the boundary through which buildings interact with the environment and the whole city. The aim of this paper isto discussbiomimicry as a tool to reduce energy consumption in cities through buildingskins. It also discusses concepts of smart cities. It provides an overviewof biomimicry as a tool of achieving a perfect biomimetic skin of buildings in smart cities. In addition it analysescase studies of energy conservationusing concepts of biomimicry. Finally it would conclude guidelines for biomimicry design of building skinsas a tool for reducing energy consumption in smart citie

    Optimizing the Process of Arc-Spraying To Improve Wear Resistance of Crank Shaft

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    This research studies the factors effecting on coating produced by electrical arcspraying. The studied variables are applied voltage, wire feed rate and spraying distance.In this investigation used wires made from martinsitic stainless steel to coat the bearing of spherical graphite cast iron. range. The mechanical properties of coating such as hardness are used.Limited optimal environments by electric arc spraying to improve wear rate resistance of crank shaft.In the first stage all samples and metallizing wires were prepared and chemically analyzed. The coating operation was carried in the second stage. Each group of samples was coated in different way with variable spraying factor being considered. In the third stage all samples were tested using pin on ring wear testing machine. The investigation performed in this work showed that the process variable have a considerable effect on coating quality ,and spraying distance range emerges as the most significant process variables. The final results showed that the best voltage in this application is between 28-30V, wire feed rate is 100 mm/s, and best spraying distance is about 12-15cm to get a good coating with maximum wear resistance

    Preparation, Characterization and Structural Studies of Some Phenyl Isothiocynate Metal Complexes

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    Phenyl isothiocynate complexes of Cu (I), Cu(II), Mn(II), Fe(II), Fe (III), Cr(III) and Ce(III) have been prepared and analyzed spectroscopicaly by Elemental analyses and atomic absorption technique; the magnetic susceptibility and the conductivity have also been measured and molar ratio of Ligand: Matale with mole ratio method and Job Method. From these measurement it is concluded that Cu(I), Fe(III) and Mn(II) form tetrahedral complexes, while Cu (II) Forms square planner complexes, and Cr (III) and Ce(III) forms octahedral complexes

    Extending the shelf-life of fresh-cut green bean pods by ethanol, ascorbic acid, and essential oils

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    Green beans are a perishable crop, which deteriorate rapidly after harvest, particularly when minimally processed into ready-to-eat fresh-cut green beans. This study investigated the effectiveness of ethanol, ascorbic acid (AsA), tea tree essential oil (TTO), and peppermint essential oil (PMO) on the quality and storability of fresh-cut green bean pods samples stored at 5 °C for 15 days. Our results indicated that samples treated with ethanol, AsA, TTO, and PMO preserved appearance, firmness (except ethanol), chlorophyll content, and moisture compared with the samples without any treatment (control). Additionally, higher vitamin C, total soluble solids (TSS), total sugars, and total phenolic compounds (TPC) were observed in samples treated with ethanol, AsA, TTO, and PMO compared with the control. The most effective treatments for controlling microbial growth were ethanol followed by either TTO or PMO. All the treatments had positive effects on shelf life, maintained quality, and reducing microbial growth during 15 days of cold storage. A particular treatment can be selected based on the economic feasibility and critical control point in the value chain

    Increasing the storability of fresh-cut Green beans by using chitosan as a carrier for tea tree and peppermint essential oils and ascorbic acid

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    The quality of fresh-cut green beans deteriorates rapidly in storage, which contributes to increased food waste and lower perceived customer value. However, chitosan (Cs) and certain plant essential oils show promise in reducing postharvest quality loss during storage. Here, the effect of Cs and the combinations of Cs + tea tree oil (TTO), Cs +x peppermint oil (PMO), and Cs + ascorbic acid (AsA) on the quality of fresh-cut green bean pods (FC-GB) is studied over a 15-d storage period at 5 °C. All four FC-GB treatments reduced weight loss and maintained firmness during storage when compared to uncoated FC-GB. Furthermore, all treatments showed higher total chlorophyll content, AsA, total phenolic compounds, and total sugars compared to the control. The best treatment for reducing microbial growth was a combination of Cs + AsA. Additionally, the combination of Cs with TTO, PMO, or AsA showed a significant reduction in the browning index and increased the antioxidant capacity of FC-GB up to 15 d postharvest

    Melatonin downregulates the increased hepatic alpha-fetoprotein expression and restores pancreatic beta cells in a streptozotocin-induced diabetic rat model: a clinical, biochemical, immunohistochemical, and descriptive histopathological study

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    BackgroundDiabetes mellitus (DM) is a chronic metabolic disorder. Hepatopathy is one of the serious effects of DM Melatonin (MT) is a potent endogenous antioxidant that can control insulin output. However, little information is available about the potential association between melatonin and hepatic alpha-fetoprotein expression in diabetes.ObjectiveThis study was conducted to assess the influence of MT on diabetes-related hepatic injuries and to determine how β-cells of the pancreas in diabetic rats respond to MT administration.Materials and methodsForty rats were assigned to four groups at random (ten animals per group). Group I served as a normal control group. Group II was induced with DM, and a single dose of freshly prepared streptozotocin (45 mg/kg body weight) was intraperitoneally injected. In Group III, rats received 10 mg/kg/day of intraperitoneal melatonin (IP MT) intraperitoneally over a period of 4 weeks. In Group IV (DM + MT), following the induction of diabetes, rats received MT (the same as in Group III). Fasting blood sugar, glycosylated hemoglobin (HbA1c), and serum insulin levels were assessed at the end of the experimental period. Serum liver function tests were performed. The pancreas and liver were examined histopathologically and immunohistochemically for insulin and alpha-fetoprotein (AFP) antibodies, respectively.ResultsMT was found to significantly modulate the raised blood glucose, HbA1c, and insulin levels induced by diabetes, as well as the decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Furthermore, MT attenuated diabetic degenerative changes in the pancreas and the hepatic histological structure, increased the β-cell percentage area, and decreased AFP expression in the liver tissue. It attenuated diabetes-induced hepatic injury by restoring pancreatic β-cells; its antioxidant effect also reduced hepatocyte injury.ConclusionCollectively, the present study confirmed the potential benefits of MT in downregulating the increased hepatic alpha-fetoprotein expression and in restoring pancreatic β-cells in a streptozotocin-induced diabetic rat model, suggesting its promising role in the treatment of diabetes

    Antibody Response to SARS-CoV-2: A Cohort Study in Qatar's Primary Care Settings.

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    Globally, countries are rolling out Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) quarantine policies and vaccination programs. Research studies are needed in helping understand the likelihood of acquired immunity to reinfection and identify priority groups for vaccination to inform them. This study aimed to assess period prevalence and longitudinal changes in antibody levels after SARS-CoV-2 infection in Qatari primary care settings. A cohort study design with 2 data collection phases was undertaken-Phase 1 (conducted in July 2020) and Phase 2 (conducted in October 2020). A stratified random sampling technique by age, gender and nationality was utilized to identify the study sample. The total sample size required for the study was estimated to be 2102. Participants were invited to an appointment where they were administered a questionnaire and provided samples for polymerase chain reaction and Immunoglobulin G immunoassay tests. A total of 943 individuals participated in both Phase 1 and Phase 2. In this cohort, seroprevalence of SARS-CoV-2 was found to be 12% (N = 113) in Phase 1 and 17.2% (N = 162) in Phase 2. Of the 113 participants who were seropositive in Phase 1, 38.1% (CI 29.5-47.2%, N = 43) had a reduction, 54.9% (CI 45.7-63.8%, N = 62) had no change, and 7.1% (CI 3.4-12.9%, N = 8) had an increase in IgG titer in Phase 2. All (N = 18) participants aged 10 to 17 years retained their antibodies. The proportion of men who retained their antibodies was slightly higher compared to women-92.5% (N = 74) and 87.9% (N = 29) respectively. Similarly, symptomatic individuals (97.8%; N = 45) had a higher antibody retention compared with asymptomatic individuals (86.4%; N = 57). This study provides preliminary information on the longitudinal changes in antibody levels after SARS-CoV-2 infection. These findings will help inform quarantine policies and vaccination programs.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by PHCC (PHCCDCR202005047).The funders had no role in the design, analysis, interpretation, or writing

    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

    Melatonin ameliorates serobiochemical alterations and restores the cardio-nephro diabetic vascular and cellular alterations in streptozotocin-induced diabetic rats

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    Melatonin possesses a wide range of pharmacological activities, including antidiabetic properties. Diabetes mellitus (DM) induces several physiopathological changes in body organs, which could be observed lately after systemic failure. In the current study, we aimed to investigate the serobiochemical changes and the histopathological picture in the diabetic heart and the kidney early before chronic complications and highlight the association between hyperglycemia, glomerular alterations, and cardiovascular changes. In addition, the role of melatonin in the treatment of cardio-nephro diabetic vascular and cellular adverse changes in streptozotocin-induced diabetic rats was also studied. A total of 40 mature Wistar albino rats were distributed into five groups; (1) control untreated rats, (2) diabetic mellitus untreated (DM) rats, in which DM was induced by the injection of streptozotocin (STZ), (3) control melatonin-treated (MLT), (4) melatonin-treated diabetic (DM + MLT) rats, in which melatonin was injected (10 mg/kg/day, i.p.) for 4 weeks, and (5) insulin-treated diabetic (DM + INS) rats. The serum biochemical analysis of diabetic STZ rats showed a significant (P < 0.05) increase in the concentrations of blood glucose, total oxidative capacity (TOC), CK-MB, endothelin-1, myoglobin, H-FABP, ALT, AST, urea, and creatinine as compared to control rats. In contrast, there was a significant (P < 0.05) decrease in serum concentration of insulin, total antioxidative capacity (TAC), total nitric oxide (TNO), and total protein level in DM rats vs. the control rats. Significant improvement in the serobiochemical parameters was noticed in both (DM + MLT) and (DM + INS) groups as compared with (DM) rats. The histological examination of the DM group revealed a disorder of myofibers, cardiomyocyte nuclei, and an increase in connective tissue deposits in between cardiac tissues. Severe congestion and dilation of blood capillaries between cardiac muscle fibers were also observed. The nephropathic changes in DM rats revealed various deteriorations in glomeruli and renal tubular cells of the same group. In addition, vascular alterations in the arcuate artery at the corticomedullary junction and interstitial congestion take place. Melatonin administration repaired all these histopathological alterations to near-control levels. The study concluded that melatonin could be an effective therapeutic molecule for restoring serobiochemical and tissue histopathological alterations during diabetes mellitus
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