1,027 research outputs found

    Damage identification in a concrete beam using curvature difference ratio

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    Previous studies utilising changes in mode shape or curvature to locate damage rely on the fact that the greatest change occurs around the defect. However, in concrete beams this fact is undermined due to the nature of the defect as distributed multi-site cracks. In addition, differences in mode shape and curvature as ways to locate the damage is unstable because of occurrence of modal nodes and inflection points. In this paper, one interesting solution to this problem is being tested by establishing a new non-dimensional expression designated the 'Curvature Difference Ratio (CDR)'. This parameter exploits the ratio of differences in curvature of a specific mode shape for a damaged stage and another reference stage. The expression CDR is reasonably used to locate the damage and estimate the dynamic bending stiffness in a successively loaded 6m concrete beam. Results obtained by the proposed technique are tested and validated with a case study results done by Ren and De Roeck [1] also by Maeck and De Roeck [2]. Another contribution of this work is that relating changes in vibration properties to the design bending moment at beam sections as defined in Eurocode 2 specifications [3]. Linking between a beam section condition and the change in vibration data will help to give a better comprehension on the beam condition than the applied load

    Effect of Blast Loading on Seismically Detailed RC Columns and Buildings

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    Explosions caused by standoff charges near buildings have drastic effects on the internal and external structural elements which can cause loss of life and fatal injuries in case of failure or collapse of the structural element. Providing structural elements with blast resistance is therefore gaining increasing importance. This paper presents numerical investigation of RC columns with different reinforcement detailing subjected to near-field explosions. Detailed finite element models are made using LS-DYNA software package for several columns having seismic and conventional reinforcement detailing which were previously tested under blast loads. The numerical results show agreement with the published experimental results regarding displacements and damage pattern. Seismic detailing of columns enhances the failure shape of the column and decrease the displacement values compared to columns with conventional reinforcement detailing. Further, the effect of several modeling parameters are studied such as mesh sensitivity analysis, inclusion of air medium and erosion values on the displacements and damage pattern. The results show that decreasing the mesh size, increasing erosion value and inclusion of air region provide results that are very close to experimental results. Additionally, application is made on a slab-column multistory building provided with protective walls having different connection details subjected to blast loads. The results of this study are presented and discussed. Use of a top and bottom floor slab connection of protective RC walls are better than using the full connection at the four sides to the adjacent columns and slabs. This leads to minimizing the distortion and failure of column, and therefore it increases the chance of saving the building from collapse and saving human lives. Doi: 10.28991/cej-2021-03091733 Full Text: PD

    Use of evidence to support healthy public policy: a policy effectiveness-feasibility loop

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    Public policy plays a key role in improving population health and in the control of diseases, including non-communicable diseases. However, an evidence-based approach to formulating healthy public policy has been difficult to implement, partly on account of barriers that hinder integrated work between researchers and policy-makers. This paper describes a “policy effectiveness–feasibility loop” (PEFL) that brings together epidemiological modelling, local situation analysis and option appraisal to foster collaboration between researchers and policy-makers. Epidemiological modelling explores the determinants of trends in disease and the potential health benefits of modifying them. Situation analysis investigates the current conceptualization of policy, the level of policy awareness and commitment among key stakeholders, and what actually happens in practice, thereby helping to identify policy gaps. Option appraisal integrates epidemiological modelling and situation analysis to investigate the feasibility, costs and likely health benefits of various policy options. The authors illustrate how PEFL was used in a project to inform public policy for the prevention of cardiovascular diseases and diabetes in four parts of the eastern Mediterranean. They conclude that PEFL may offer a useful framework for researchers and policy-makers to successfully work together to generate evidence-based policy, and they encourage further evaluation of this approach

    Genetic distance and heterogenecity between quasispecies is a critical predictor to IFN response in Egyptian patients with HCV genotype-4

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    BACKGROUND: HCV is one of the major health problems in Egypt, where it is highly prevalent. Genotype 4 is the most common genotype of HCV and its response to treatment is still a controversy. METHODS: HCV genotype 4 quasispecies diversity within the 5' untranslated region (5'UTR) was studied in a series of 22 native Egyptian patients with chronic hepatitis C virus with no previous treatment who satisfied all NIH criteria for combined treatment of pegylated IFN and ribavirine and was correlated with the outcome of treatment. The study also included 7 control patients with no antiviral treatment. HCV sequencing was done using the TRUGENE HCV 5-NC genotyping kit. RESULTS: At the 48(th )week of treatment, 15 patients (68%) showed virological response. Whereas HCV-RNA was still detected in 7 patients (32%) in this period; of those, 6 experienced a partial virological response followed by viral breakthrough during treatment. Only one patient did not show any virological or chemical response. The four females included in this study were all responders. There was a significant correlation between the response rate and lower fibrosis (p = 0.026) as well as the total number of mutation spots (including all the insertions, deletions, transitions and transversions) (p = 0.007, p = 0.035). CONCLUSION: Patients who responded to interferon treatment had statistically significant less number in both transitions (p = 0.007) and the genetic distances between the quasispecies (p = 0.035). So, viral genetic complexity and variability may play a role in the response to IFN treatment. The consensus alignment of all three groups revealed no characteristic pattern among the three groups. However, the G to A transitions at 160 was observed among non responders who need further study to confirm this observation

    Imaging with Hexagonal Segmented Mirror

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    Different hexagons configuration aperture models of the optical telescope mirror is carefully considered in this study. The point spread function and the modulation transfer function of a reference star using different hexagons configuration are computed and the quantitative assessment for the results are described. It has been shown that the height of the point spread function decreases rapidly when the area of the circular aperture of the optical telescope is 18 times the area of the individual hexagon to be arrange to fill this aperture. No significant change has been noticed as the area of the this aperture exceeds 121 times the area of the individual hexagon

    QualitĂ© bactĂ©riologique et physique des eaux de l’Oued Hassar (Casablanca, Maroc): CaractĂ©risation et analyse en Composantes principales

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    The objective of this study is to evaluate the bacteriological quality of water of Oued Hassar in relation to the wastewater of Mediouna’s location and also to apply a statistical analysis using the Principal Component Analysis (PCA) to correlate data of spatio-temporal variability of bacterial indicators with those of physical parameters (temperature, pH, electrical conductivity and turbidity). The average values obtained ​​indicate that the water of this river contains a lot of amount of bacteria that indicates a faecal contamination. These values, for total coliforms, faecal coliforms and faecal Streptococci were hight and more than seven log10. Then the bacteriological quality of water of oued Hassar is classified in poor to very poor category. The Principal Component Analysis revealed that the indicator bacteria of faecal contamination presents negative correlations with the pH and the electrical conductivity, and positive correlations that are highly significant with turbidity.La prĂ©sente Ă©tude consiste Ă  Ă©valuer la qualitĂ© bactĂ©riologique des eaux d’Oued Hassar en relation avec les effluents de la localitĂ© de Mediouna et d’appliquer une mĂ©thode statistique d’Analyse en Composantes Principales (ACP) pour corrĂ©ler les donnĂ©es de la variabilitĂ© spatio-temporelle des indicateurs bactĂ©riologiques Ă  ceux des paramĂštres physiques (tempĂ©rature, pH, conductivitĂ© Ă©lectrique et turbiditĂ©). Les valeurs moyennes obtenues rĂ©vĂšlent que les eaux de ce cours d’eau prĂ©sentent une charge trĂšs importante en bactĂ©ries indicatrices de la contamination d’origine fĂ©cale. Les teneurs en coliformes totaux, coliformes fĂ©caux et streptocoques fĂ©caux atteignent des valeurs importantes supĂ©rieures Ă  sept log10. De ce fait, la qualitĂ© bactĂ©riologique des eaux d’Oued Hassar est classĂ©e dans la catĂ©gorie mauvaise Ă  trĂšs mauvaise. L’ACP a rĂ©vĂ©lĂ© que les bactĂ©ries indicatrices de la contamination fĂ©cale prĂ©sentent des corrĂ©lations nĂ©gatives avec le pH et la conductivitĂ© Ă©lectrique et des corrĂ©lations positives et fortement significatives avec la turbiditĂ©

    Antibacterial, antioxidant and anti-proliferative properties and zinc content of five south Portugal herbs

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    Context: Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal. Objective: To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc. Material and methods: Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48 h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24 h) was tested using HEP G2 cells and fibroblasts. Results: Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90mg AAE/g dw and 783.48mg TE/g dw, respectively). CM had the highest zinc concentration (37.21 mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91 mg/100 g dw). LS was rich in rosmarinic acid (301.71 mg/100 g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830 mu g/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content. Conclusion: The most promising plants for further studies are CM, LS and GP.FCT, Fundacao para a Ciencia e a Tecnologia of Portugal [SFRH/BSA/139/2014

    Circulating tumor cells (CTC) are associated with defects in adaptive immunity in patients with inflammatory breast cancer

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    BACKGROUND: Circulating tumor cells (CTCs) play a crucial role in tumor dissemination and are prognostic in primary and metastatic breast cancer. Peripheral blood (PB) immune cells contribute to an unfavorable microenvironment for CTC survival. This study aimed to correlate CTCs with the PB T-cell immunophenotypes and functions of patients with inflammatory breast cancer (IBC). METHODS: This study included 65 IBC patients treated at the MD Anderson Cancer Center. PB was obtained from patients prior to starting a new line of chemotherapy for CTCs enumeration by CellSearch(Âź), and T cell phenotype and function by flow cytometry; the results were correlated with CTCs and clinical outcome. RESULTS: At least 1 CTC (≄1) or ≄5 CTCs was detected in 61.5% or 32.3% of patients, respectively. CTC count did not correlate with total lymphocytes; however, patients with ≄1 CTC or ≄5 CTCs had lower percentages (%) of CD3+ and CD4+ T cells compared with patients with no CTCs or <5 CTCs, respectively. Patients with ≄1 CTC had a lower percentage of T-cell receptor (TCR)-activated CD8+ T cells synthesizing TNF-α and IFN-Îł and a higher percentage of T-regulatory lymphocytes compared to patients without CTCs. In multivariate analysis, tumor grade and % CD3+ T-cells were associated with ≄1 CTC, whereas ≄5 CTC was associated with tumor grade, stage, % CD3+ and % CD4+ T cells, and % TCR-activated CD8 T-cells synthesizing IL-17. CONCLUSIONS: IBC patients with CTCs in PB had abnormalities in adaptive immunity that could potentially impact tumor cell dissemination and initiation of the metastatic cascade

    Phytochemicalanalysis,cytotoxic,antioxidant,andantibacterial activities of lichens

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    © 2020 Noura Aoussar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Lichens present a complex symbiotic relationship between a filamentous fungus, photoautotrophic partner (algae or cyanobacteria), and bacterial community. The Objective of the Study. This study aimed at investigating the chemical composition and cytotoxic, antioxidant, and antimicrobial activities of acetone extracts of Moroccan Evernia prunastri (E. prunastri), Ramalina farinacea (R. farinacea), and Pseudevernia furfuracea (P. furfuracea). Materials and Methods. The phytochemical analysis was carried out by HPLC-UV. The cytotoxic effect was assessed on human prostate cancer (22RV1), human colon carcinoma (HT-29), human hepatocellular carcinoma (Hep-G2), and Hamster ovarian cancer (CHO) cells lines by WST1 assay. The antioxidant power was assessed by DPPH and FRAP assays. The antibacterial effect was obtained using the broth microdilution method. Results. The findings of phytochemical analysis showed that the lichens studied possess interesting bioactive molecules such as physodalic acid, evernic acid, and usnic acid, as well as protocetraric acid. According to the American National Cancer Institute guidelines, the WST-1 test showed that all crude extracts did not show significant cytotoxic effects against all concerous cell lines, and IC50 values ranged from 42.30 to 140.24 ”g/mL. Regarding the antioxidant activity, P. furfuracea extract showed the highest free-radical-scavenging ability (IC50 = 498.40 ”g/mL). The most potent antibacterial extract was recorded for P. furfuracea extract with a minimum inhibitory concentration (MIC) ranging from 0.039 to 0.31 mg/mL. Conclusion. In this research work, we report that the studied lichen extracts exhibit an important biological effect, supporting that lichens represent a hopeful source of original natural products for the research of new bioactive molecules having a pharmaceutical interest

    Antimicrobial Potential of Plastic Films Incorporated with Sage Extract on Chicken Meat

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    The function of packaging is crucial in the maintenance of fresh meat product quality. This study aimed to assess the efficiency of six films added with coatings 2379L/220 and 2379L/221 (containing sage extracts) to inhibit Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli, which showed that two of the six films had a significant effect. Additionally, the effects of the films on refrigerated skinless chicken breast meat were evaluated based on microbiological content, colour, weight loss, texture and pH. Four of the six films were examined could extend the storability of refrigerated chicken breast fillets for up to seven days. All six treated films improved the pH, colour stability, weight loss, and texture of the chicken fillets. Therefore, these findings suggested that the coatings containing sage extracts having different viscosities (2379L/220 and 2379L/221) were effective as antimicrobial adhesives in food packaging films and can be commercially applied in prolonging the storage of chicken breast meat without affecting their quality
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