Exploring the Effect of In-plane Tensile Forces on the Two-way Shear Strength: review, comparative study and future works

Two-way shear failure of slabs is a sudden one, which has catastrophic outcomes. Slabs with large spans may be subjected to in-plane tensile forces due to thermal or earthquake loading. There is a lack of agreement between various design codes regarding the significance of in-plane tensile forces on the two-way shear strength. Two-way shear failure of slabs is a sudden one, which has catastrophic outcomes. Slabs with large dimensions may be subjected to in-plane tensile forces due to restraint or earthquake loading. There is a lack of agreement between various design codes regarding the significance of in-plane tensile forces on the two-way shear strength. The purpose of this study is to explore, propose a simplified two-way shear strength model, which includes the effect of in-plane tensile forces on the strength. A review for the experimental investigations, existing models, design codes for two-way shear of slabs is presented, with emphasis on in-plane tensile forces. The loading method used in the current experimental testing is misleading, where the two-way shear and the in-plane forces are independent. A comparative study was conducted between the existing formula and design codes for this case. The comparison between different codes with the experimental results show that the new proposed Eurocode design code was found to be the most accurate one. However, it did not include the effect of the in-plane tensile forces in a physically sound manner. In addition, more full testing of concrete slabs under combined two-way shear and tensile forces are required to refine this existing two-way shear design code provisions or develop new formulas or mechanical models

Review on carbonation study of reinforcement concrete incorporating with bacteria as self-healing approach

This study carried out a comprehensive review to determine the carbonation process that causes the most deterioration and destruction of concrete. The carbonation mechanism involved using carbon dioxide (CO2 ) to penetrate the concrete pore system into the atmosphere and reduce the alkalinity by decreasing the pH level around the reinforcement and initiation of the corrosion process. The use of bacteria in the concrete was to increase the pH of the concrete by producing urease enzyme. This technique may help to maintain concrete alkalinity in high levels, even when the carbonation process occurs, because the CO2 accelerates to the concrete and then converts directly to calcium carbonate, CaCO3 . Consequently, the self-healing of the cracks and the pores occurred as a result of the carbonation process and bacteria enzyme reaction. As a result of these reactions, the concrete steel is protected, and the concrete properties and durability may improve. However, there are several factors that control carbonation which have been grouped into internal and external factors. Many studies on carbonation have been carried out to explore the effect of bacteria to improve durability and concrete strength. However, an in-depth literature review revealed that the use of bacteria as a self-healing mechanism can still be improved upon. This review aimed to highlight and discuss the possibility of applying bacteria in concrete to improve reinforcement concrete

mRNA trans-splicing dual AAV vectors for (epi)genome editing and gene therapy

Large genes including several CRISPR-Cas modules like gene activators (CRISPRa) require dual adeno-associated viral (AAV) vectors for an efficient in vivo delivery and expression. Current dual AAV vector approaches have important limitations, e.g., low reconstitution efficiency, production of alien proteins, or low flexibility in split site selection. Here, we present a dual AAV vector technology based on reconstitution via mRNA trans-splicing (REVeRT). REVeRT is flexible in split site selection and can efficiently reconstitute different split genes in numerous in vitro models, in human organoids, and in vivo. Furthermore, REVeRT can functionally reconstitute a CRISPRa module targeting genes in various mouse tissues and organs in single or multiplexed approaches upon different routes of administration. Finally, REVeRT enabled the reconstitution of full-length ABCA4 after intravitreal injection in a mouse model of Stargardt disease. Due to its flexibility and efficiency REVeRT harbors great potential for basic research and clinical applications

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

FLEXURAL STRENGTHENING OF REINFORCED CONCRETE GIRDERS USING POST-TENSIONED CONCRETE JACKETS

Thesis Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in CIVIL ENGINEERING (STRUCTURES)Flexural strengthening of reinforced concrete girders is an important side of the construction industry and its importance is on the rise. There are different techniques used to study the response of repaired and strengthened girders, each with different advantages and drawbacks. External pre-stressing was initially developed for retrofitting of bridges, but now it is used for both retrofitting and in building new structures. Due to its simplicity and cost effectiveness, pre-stressed concrete bridges with external pre-stressing are becoming popular. This study discusses the flexural behavior of reinforced concrete girders strengthened using post-tensioning embedded in concrete jackets. The concept benefits from the external jacket to help increase the cross-section inertia as well as to host the posttensioning tendons without the need of external deviators. This study incorporated two phases namely, experimental and analytical phases. The experimental phase of this study was conducted on two stages. The first stage deals with girders loaded on their original section firstly and then strengthened with the posttensioned jacket and loaded to failure, while the second had the girders that were strengthened before being subjected to loads. In addition to the stage of jacket introduction, the difference between the original girder and the jacket’s concrete compressive strength was also studied. The experimental results showed that both the strength and the stiffness of the girders were enhanced significantly, this means that this technique can be used for mitigating the effect of increased deflections as well as loss of strength, the stage at which the jacket is introduced slightly affects the strength and stiffness of the girders. In the analytical phase of the study, a numerical model was built using the finite element method to simulate the response of the tested girders in the experimental phase. The analytical results show a very good match and correlation with the experimental results. A parametric study was developed on the flexural behavior of strengthen girders to investigate the effect of the damage level of girder before strengthening as well as increasing the pre-stressing ratio, also to study the effect of increasing the compressive strength of the original girder. The analytical results showed that, the stiffness and the strength of the strengthened girders increase with the decrease of the damage level for the original girder, and the load carrying capacity increases by increasing the percentage of pre-stressing area to the total cross-sectional area. Also, it was observed that the stiffness of the girders was enhanced significantly by increasing the concrete compressive strength of the original girderSupervised by Dr. Amr Abdelrahman ; Dr. Hussein Okai

A doubl

Background: The aim of this study was to evaluate the effects of adding two different doses (2.5 mg or 5 mg) of verapamil to lidocaine ketamine (0.5 mg/kg) during Intravenous Regional Anesthesia (IVRA) compared with lidocaine with ketamine alone. Methods: Seventy-five patients, aged 18–50 years, ASA physical status I and II undergoing elective hand or forearm surgery under Bier’s Block lasting one to one and half hours were included in this randomized controlled double-blind study. Patients were divided into three groups, 25 each to receive either group (I, control group) received 40 ml of 0.5% Lidocaine plus ketamine (0.5 mg/kg), group (II) received as group I plus verapamil 2.5 mg or group (III) received as group I plus verapamil 5 mg for IVRA. Postoperative assessment of block characteristics, sedation, pain, first time for rescue analgesia, hemodynamic changes and side effects were evaluated over a period of 12 h. Results: Block characteristics were significant in groups II and III compared with group I. There were significant hemodynamic changes, sedation score, pain score and delayed first request for analgesics postoperatively in groups (II) and (III) compared to group (I) postoperatively. There was no significant difference in group (III) compared to group (II) postoperatively. The incidence of postoperative side effects were more in group (III). Conclusion: Adding verapamil 2.5 mg to Lidocaine plus ketamine (0.5 mg/kg) for IVRA was effective and safe adjuvant for acute pain after surgery

The impact of diversity on job performance: evidence from private universities in Egypt

Employees from diverse backgrounds have been claimed to perform better; nevertheless, this link has been studied sparingly in the Egyptian setting. This paper addresses this gap by experimentally analyzing the link between employee performance and gender, educational background, and ethnic background. To investigate this link, a usable model was created, and data was collected from 269 academic staff members at private Egyptian institutions. PLS analysis was used, and the result revealed that educational and ethnic backgrounds have a positive effect on employees’ job performance whereas, the impact of gender background on employee’s job performance was found to be insignificant. Furthermore, the research findings disclose that the education and ethnic background of the employees mediates the relationship between employees’ job performance and gender diversity. Future research is yet to validate these results

Analysis of the role of servant leadership on employee’s job satisfaction mediated by leader-member exchange style among employees in the private higher education sector in Kuwait

A growing body of literature explores the underlying mechanisms and processes that enable servant leadership to impact organizational performance, engagement, and outcomes positively. This research assesses the mediation role of leader-member exchange between servant leadership and job satisfaction among employees in Kuwait's universities. The study utilized a closed-ended survey that was distributed to 240 workers, with 205 valid responses received from employees working in two private higher education sectors in Kuwait. using Partial Least Squares-Structural Equation Modeling (PLS-SEM) was used for data analysis. The outcomes of the study demonstrated strong backing for the beneficial influence of servant leadership on leader-member exchange and job satisfaction. Furthermore, a positive correlation was established between leader-member exchange and job satisfaction among employees employed in Kuwait's private higher education sector. Moreover, the results partially validated the mediating effect of leader-member exchange in the relationship between servant leadership and employee job satisfaction. These results underscore the significance of integrating servant leadership principles into leadership approaches within this sector to improve employee satisfaction and overall organizational achievement

Comparison of the effects of transversus thoracic muscle plane block and pecto-intercostal fascial block on postoperative opioid consumption in patients undergoing open cardiac surgery: a prospective randomized study

Abstract Background There is an association exists between cardiac surgery, performed through median sternotomy, and a considerable postoperative pain. Objectives The aim of the current study is to compare the effects of transversus thoracic muscle plane block (TTMPB) and pecto-intercostal fascial plane block (PIFB) upon postoperative opioid consumption among the patients who underwent open cardiac surgery. Methods The present prospective, randomized, comparative study was conducted among 80 patients who underwent elective on-pump cardiac surgery with sternotomy. The subjects were randomly assigned to two groups with each group containing 40 individuals. For the TTMPB group, bilateral ultrasound-guided TTMPB was adopted in which 20 ml of 0.25% bupivacaine was used on each side. In case of PIFB group, bilateral ultrasound-guided PIFB was adopted with the application of 20 ml of 0.25% bupivacaine on each side. The researchers recorded the first time for rescue analgesia, the overall dosage of rescue analgesia administered in the first 24 h after the operation and the postoperative complications. Results The PIFB group took significantly longer time to raise the first request for rescue analgesia (7.8 ± 1.7 h) than the TTMPB group (6.7 ± 1.4 h). Likewise, the PIFB group subjects had a remarkably lower ‘overall morphine usage’ in the first 24 h after the operation (4.8 ± 1.0 mg) than TTMPB group (7.8 ± 2.0 mg). Conclusion Bilateral ultrasound-guided PIFB provided a longer time for the first analgesic demand than bilateral ultrasound-guided TTMPB in patients undergoing open cardiac surgery. In addition to this, the PIFB reported less postoperative morphine usage than the TTMPB and increases satisfaction in these patients. Trial registration This study was registered at Clinical Trials.gov on 28/11/2022 (registration number: NCT05627869)