Behavior of RC Wide Beams under Eccentric Loading

Wide beams are one of the widely used structural elements in RC buildings due to the many special features that characterize them. The main objective of this research is to investigate the behavior of wide shallow beams under the effect of eccentric loading acting along their cross sections. To achieve that, an experimental program that consisted of seven wide beams was conducted. All beams were loaded using two concentrated loads at their middle third where the main parameters considered were: the magnitude of the load eccentricity, the longitudinal spacing between shear reinforcement, and the arrangement of the longitudinal reinforcement. Following that, a finite element analysis was performed where the analytical model used was first verified using the data from the experimental program. The results from both the experimental and analytical programs were in good agreement. Then, the finite element analysis was extended through a parametric study where other variables were studies such as the compressive strength of concrete, the transverse spacing between stirrups and the longitudinal reinforcement ratio. The results showed that the value of the load eccentricity, spacing between shear reinforcement, the arrangement of the main reinforcement along the beam cross section, and the compressive strength of concrete significantly affected the torsional resistance of shallow wide beams. Conclusions and recommendations are presented which can be useful for future researchers. Doi: 10.28991/cej-2021-03091766 Full Text: PD

Effect of ciprofloxacin incorporation in PVA and PVA bioactive glass composite scaffolds

International audienceScaffolds are implants used to deliver cells, drugs, and genes into the body in a local controlled release pattern which offers many advantages over systematic drug delivery. Composite scaffolds of polyvinyl alcohol (PVA) and quaternary bioactive glass (46S6 system) with different ratios of glass contents were prepared by the lyophilisation technique. The broad spectrum antibiotic ciprofloxacin (Cip) was impregnated to the scaffold during the fabrication in a concentration of 5, 10 and 20%. Biodegradation rate and in-vitro mineralization of the prepared scaffolds were performed by soaking the scaffolds in simulated body fluid (SBF). Phase identification, microstructure, porosity, bioactivity, mechanical properties and drug release pattern in PBS were characterized by XRD, SEM coupled with EDS, Hg-porosimeter, inductively coupled plasma-optical emission spectroscopy (ICP-OES), universal testing machine, fourier transform infrared (FTIR) and UV-spectrophotometer, respectively. A porous scaffold has been obtained with porosity up to 85%. By increasing the glass contents in the prepared scaffold the porosity and the degradation rate decrease however, the compressive strength was enhanced. A sustained drug release pattern was observed with a quasi-Fickian diffusion mechanism. The formulated ciprofloxacin loaded porous polyvinyl alcohol scaffold gave an acceptable physicochemical properties and was able to deliver the drug in a prolonged release pattern which offers a distinguish treatment for osteomylitis as well as local antibacterial effect

Durability of modified sulfur concrete in sewerage environment

This study verifies and validates the superiority of sulfur concrete (SC) over the ordinary Portland cement concrete (PCC) and sulfate-resistant concrete (SRC) in sewer harsh environments. A field study was performed in an actual sewage environment, specifically at the sewer’s gas and sludge environments. Performance of the PCC, SRC and two types of SC was assessed after 3, 6, 10, 18 and 24 months of exposure. Specimen’s durability was evaluated through physical appearance, change in weight and mechanical and hydraulic properties. The microstructure and the composition of the specimens were studied by means of scanning electron microscopy and X-ray diffraction. Attempts have been made to explain the mechanism of deterioration, the basic chemical interactions involved in the deterioration processes and the effect of such interactions on the concrete and reinforcing steel. It was found that SC is highly resistant to sewer environment compared to PCC and SRC, and that there was a significant weight loss of 8·0% and 13·6% in PCC and SRC, respectively, whereas a smaller weight loss of 2·2% was noticed in SC. This is consistent with the observed reduction in strength, increase in permeability and noticeable steel bar corrosion for the PCC and SRC relative to the SC

The serum thyroid hormone profile in mechanically ventilated children: Does euthyroid sick syndrome exist?

Background: The term "euthyroid sick syndrome" refers to alterations in thyroid function testing during critical illness. Mechanically ventilated children's thyroid hormone levels may be altered, although the reason for this remains a mystery.Objective: This study was aimed to evaluate thyroid hormone profile in mechanically ventilated children and their correlation with mortality.Patients and Methods: Thirty-four mechanically ventilated children were enrolled in a prospective cohort study. On the first and third days of mechanical ventilation, serum TSH, FT3, FT4 and reverse T3 were measured.Results: The mean age of the studied patients was of 31.06 ± 35.94 months. After three days of mechanical ventilation, the serum levels of FT3 and FT4 in the blood were significantly lower than the serum levels on the first day. The serum reverse T3 levels increased significantly on the third day of mechanical ventilation compared to the first day. There was a statistically significant increase in the number of patients with low FT3 and FT4 serum levels on the third day compared to the first day. Twenty-two patients (64.7%) died, and the frequency of low FT3 among dead patients was signiisignificantlycantly higher than among surviving patients.Conclusions: It could be concluded that the mechanically ventilated children had signs of euthyroid sick syndrome, shown by low levels of FT3 and FT4 and a rise in rT3 without a compensatory rise in TSH. Serum FT3 and FT4 decreased, but reverse T3 increased, on the third day of mechanical ventilation compared to the first day. Patients who had low FT3 levels died at a higher rate

Cancer Cells Treated by Clusters of Copper Oxide Doped Calcium Silicate

Purpose: Different compositions of copper oxide (CuO)-doped calcium silicate clusters wereused to treat the cancer cells.Methods: The influence of CuO content on the morphology, drug delivering ability,physicochemical properties and cytotoxicity was investigated.Results: The microcrystalline structure revealed the decrement of the size from (20-36 nm) to(5-7 nm) depending on the copper content percentages. Drug delivering ability of doxycyclinehyclate (Dox) was down regulated from 58% to 28%in the presence of the CuO. The inclusionof CuO and Dox didn’t show any remarkable changes on the physicochemical properties of theCuO-doped calcium silicate nanoparticles.Conclusion: The CuO-doped calcium silicate sample (5 weight %) exhibited great cytotoxicityagainst the tested cell lines compared to the CuO-free sample. CuO-doped materials displayedsignificant anticancer effect; this sheds light on its implication in the treatment of cancer

High-density SNP-based association mapping of seed traits in fenugreek reveals homology with clover

Fenugreek as a self-pollinated plant is ideal for genome-wide association mapping where traits can be marked by their association with natural mutations. However, fenugreek is poorly investigated at the genomic level due to the lack of information regarding its genome. To fill this gap, we genotyped a collection of 112 genotypes with 153,881 SNPs using double digest restriction site-associated DNA sequencing. We used 38,142 polymorphic SNPs to prove the suitability of the population for association mapping. One significant SNP was associated with both seed length and seed width, and another SNP was associated with seed color. Due to the lack of a comprehensive genetic map, it is neither possible to align the newly developed markers to chromosomes nor to predict the underlying genes. Therefore, systematic targeting of those markers to homologous genomes of other legumes can overcome those problems. A BLAST search using the genomic fenugreek sequence flanking the identified SNPs showed high homology with several members of the Trifolieae tribe indicating the potential of translational approaches to improving our understanding of the fenugreek genome. Using such a comprehensively-genotyped fenugreek population is the first step towards identifying genes underlying complex traits and to underpin fenugreek marker-assisted breeding programs

Thermal and entropy behavior of sustainable solar energy in water solar collectors due to non-Newtonian power-law hybrid nanofluids

Introduction: Nanofluids, hybrid nanofluid possesses thermophysical features that boost the fluid performance. This research work is motivated by the utilization of water solar collectors that incorporate non-Newtonian, power-law hybrid nanofluid in a three-dimensional model, considering the two-phase model.Method: The primary objective of this study is to transform the governing equations of the flow model into a set of ordinary differential equations by employing the three-parameters group technique. Based on the innovative discoveries, two models incorporating new associated functions have been successfully developed for two distinct scenarios characterized by the power-law index, n. The impact of physical factors on the velocity profile, temperature distribution, concentration field, and entropy output of the system is clearly illustrated through a variety of graphs.Results: The results indicated that the inclination angle of 20° had the best thermal characteristics compared to other inclinations. The entropy generation reached its maximum value at temperature difference of 13 K due to irreversibility of the system, which indicates that the system is more efficient.Discussion: Furthermore, the increasing percentage in Nusselt number is predicted to be 28.18% when the Prandtl number is taken a range. The Sherwood number enhanced up to 18.61% with a range of Brownian motion. A quantitative comparison is conducted between the present results and the literature in order to validate the superior efficiency of the used method

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