Enhanced Torsion Mechanism of Small-Scale Reinforced Concrete Beams with Spiral Transverse Reinforcement

The nonlinear torsional behaviour of small-scale reinforced concrete (RC) beams with continuous staggered spiral as transverse reinforcement stirrups is experimentally investigated. Twelve miniatures RC beams were tested under torsion load considering the closed shape of stirrups and compared with continuous staggered spiral ones. All miniatures beams were scaled down to be one-eighth the prototype beam size. The main parameters considered in this research are stirrup spacing and its configurations. Small scale RC beams were taken into account in the existing study because of their construction simplicity and financial feasibility. Mortar without coarse aggregate was applied instead of concrete to reduce the size effect of applying small scale models. Ongoing research trials have been carried out to obtain an efficacious approach to boost torsion failure mechanisms because brittle torsion failure of RC structural elements should be avoided. This study emphasized boosted torsion capacity, dissipated energy, and helical crack propagation. During testing, the primary cracking torsion moment, ultimate torsion moment, peak twist angle, and failure mechanism of the beams were inspected. The use of spiral stirrups showed great enhancement of the torsional behaviour of samples. It was observed that using spiral stirrups rather than closed stirrups could result in a substantial increase in torsion capacity and dissipated energy of 87.7% and 89.8%, respectively. As a result, the predicted capacities of the RC beams prototype were estimated in detail, taking account the scale down factor implemented by the authors. Values obtained based on international specifications and guidelines were used to compare the experimental results. Doi: 10.28991/CEJ-2022-08-11-019 Full Text: PD

STR-941: NUMERICAL INVESTIGATION OF REINFORCED CONCRETE BARRIERS SUBJECTED TO BLAST LOADING

People’s lives are threatened by explosions; the tragic terrorist attacks have forced the governments to consider the importance of dealing with these attacks. With the rising threat of terrorism, protecting critical civil infrastructure such as embassies, governmental buildings, and airports against bomb attacks has become a critical issue. In the current research, reinforced concrete barriers subjected to blast loading are numerically investigated using Applied Element Method “AEM”. The blast loads adopts the ASCE guidance for design of blast-resistant buildings in petrochemical facilities. Fully nonlinear dynamic analysis was considered where the barriers thickness and reinforcement, end connections were parametrically investigated. It was found that the thickness and reinforcement of the barriers affect the barriers’ response, where the most significant parameter was the wall thickness

An Investigation of the Fundamental Period of Vibration for Moment Resisting Concrete Frames

The determination of fundamental period of vibration for structures is essential to earthquake design. The current codes provide empirical formulas to estimate the approximated fundamental period and these formulas are dependent on building material, height of structure or number of stories. Such a formulation is excessively conservative and unable to account for other parameters such as: length to width ratios, vertical element size and floors area. This study investigated the fundamental periods of mid-rise reinforced concrete moment resisting frames. A total of 13 moment resisting frames were analyzed by ETABS 15.2.2, for gross and cracked eigenvalue analysis and Extreme Loading for Structures Software® or ELS, for non-linear dynamic analysis. The estimated periods of vibration were compared with empirical equations, including current code equations. As expected, the results show that building periods estimated based on simple equations provided by earthquake design codes in Europe (EC8) and America (UBC97 and ASCE 7-10) are significantly smaller than the periods computed using nonlinear dynamic analysis. Based on the results obtained from the analyzed models, equations for calculating period of vibration are proposed. These proposed equations will allow design engineers to quickly and accurately estimate the fundamental period of moment resisting frames with taking different length to width ratios, vertical element size, floors area and building height into account. The interaction between reduction factor and the reduced period of vibration is studied, and it is found that values of maximum period of vibration can be used as an alternative method to calculate the inelastic base shear value without taking reduction factors in consideration

Added value of diffusion-weighted magnetic resonance imaging in characterization and staging of rectal cancer

Background: Approximately 15% of all cancers are found in the rectum. Rectal cancer is one of the most common malignant tumors in patients. According to the National Cancer Institute, it's the third most frequent cancer in males and the second most prevalent cancer in women. About 96 percent of all colon cancers are adenocarcinomas, with lymphoma, gastrointestinal stromal tumors, and carcinoid among the more uncommon malignancies.Aim of the study: to discuss the accuracy of MRI at staging cancer rectum using high-resolution MRI sequences and to give a brief review about more emerging important aspects of rectal cancer staging, such as the circumferential resection margin, extramural vascular invasion, and the staging of low rectal cancers.Patients and Methods: Our study was done in the Radiodiagnosis Department, Zagazig University Hospital, with 24 patients with primary rectal cancer referred from the Surgery Department for preoperative local staging of cancer rectum; the results of MRI were compared to pathologic findings.Results: Patients included in the study were 16 females and eight males; their ages ranged from 45 to 75 years with a mean age of 60 years. Adenocarcinoma comprised about 83.3 % of all of our cases. T3 and N1 tumors were found to be the most common stages in our cases.Conclusion: Preoperative MRI utilizing high-resolution sequences is an accurate modality for preoperative grading of rectal carcinoma, delineation of affection of mesorectal fascia, circumferential resection margin, and extramural vascular invasion

No Need for Lopinavir Dose Adjustment during Pregnancy: a Population Pharmacokinetic and Exposure-Response Analysis in Pregnant and Nonpregnant HIV-Infected Subjects

ABSTRACT Lopinavir-ritonavir is frequently prescribed to HIV-1-infected women during pregnancy. Decreased lopinavir exposure has been reported during pregnancy, but the clinical significance of this reduction is uncertain. This analysis aimed to evaluate the need for lopinavir dose adjustment during pregnancy. We conducted a population pharmacokinetic analysis of lopinavir and ritonavir concentrations collected from 84 pregnant and 595 nonpregnant treatment-naive and -experienced HIV-1-infected subjects enrolled in six clinical studies. Lopinavir-ritonavir doses in the studies ranged between 400/100 and 600/150 mg twice daily. In addition, linear mixed-effect analysis was used to compare the area under the concentration-time curve from 0 to 12 h (AUC 0–12 ) and concentration prior to dosing ( C predose ) in pregnant women and nonpregnant subjects. The relationship between lopinavir exposure and virologic suppression in pregnant women and nonpregnant subjects was evaluated. Population pharmacokinetic analysis estimated 17% higher lopinavir clearance in pregnant women than in nonpregnant subjects. Lopinavir clearance values postpartum were 26.4% and 37.1% lower than in nonpregnant subjects and pregnant women, respectively. As the tablet formulation was estimated to be 20% more bioavailable than the capsule formulation, no statistically significant differences between lopinavir exposure in pregnant women receiving the tablet formulation and nonpregnant subjects receiving the capsule formulation were identified. In the range of lopinavir AUC 0–12 or C predose values observed in the third trimester, there was no correlation between lopinavir exposure and viral load or proportion of subjects with virologic suppression. Similar efficacy was observed between pregnant women and nonpregnant subjects receiving lopinavir-ritonavir at 400/100 mg twice daily. The pharmacokinetic and pharmacodynamic results support the use of a lopinavir-ritonavir 400/100-mg twice-daily dose during pregnancy

Impact of Prolonged use of Video Gaming on Grip and Pinch Strength in Young Adult

Background Video gaming has become an increasingly popular and globally recognized phenomenon in recent years While playing there are multi repetitive movements of the fingers which may lead to significant hand grip or pinch grip problems Purposes The purpose of this study was to investigate the effect of prolonged use of video games on the grip and pinch strength Materials and Methods Forty male students from King Abdulaziz University participated in this study their age ranged from 18-24 years They were divided into two groups prolonged user and non- user group The hand grip and pinch strength for all participants were measured by a handheld dynamometer and the level of video game addiction was assessed by Game Addiction Test Results There was a significant decrease in hand grip strength of the prolonged user group compared with non-user group while there was a non-significant difference between both groups in the pinch strength The result showed a nonsignificant correlation between hours of playing and Video game addiction Teat VAT with hand grip strength and pinch strength Conclusion There was a significant decrease in hand grip strength of the prolonged users of video games while there was a non-significant decrease in the pinch strength in the prolonged user group compared with non- user grou

An Overview Of Healthcare Administrative, Responsibility With The Optometrist, Nursing And Public Health Settings

A significant amount of resources will be required for large-scale public awareness initiatives about eye and vision health. These efforts will also require a presence from the federal government as well as coordination with a wide range of partners from both the public and commercial sectors. In general, the public awareness campaigns that are the most successful are those that are vast in scope and involve multiple facets. These campaigns typically involve a variety of outreach activities, stakeholders and sponsors, instructional materials, messaging, and media platforms. The responsibility that the healthcare administrator has with regard to the optometry, nursing, and public health sectors was demonstrated throughout this. Nursing in public health is a broad profession with a lack of hard and fast defined boundaries. The public health nurse does not engage in "hands on" nursing; rather, she is concerned with the prevention of illness, damage, or disability, as well as the promotion of health awareness and wellness

An Overview of Rheumatic Heart Disease Role of Physicians, Clinical Laboratory and Pharmacist in Management and Prevention

Rheumatic heart disease (RHD) continues to be a significant public health concern that impacts children and young people in developing nations. This study sought to assess the contributions of physicians, clinical laboratories, and pharmacists in the field of treatment and prevention. Chronic rheumatic heart disease (RHD) sometimes manifests with illness complications or the recurrence of rheumatic fever (RF). Insufficient management of RF/RHD results in significant harm to the heart valves and subsequent impairments. It is crucial to make active efforts in diagnosing and treating RF/RHD at an early stage, as well as implementing effective preventive measures. And everyone of the healthcare worker including physcians, nurses, pharmacist and clinical laboratory teams, have a very important roles in the management and increase the awarness among population, as well as they play a crucial role in management of RHD