فهرست مطالب ali erfani

There are some Innovative methods to control the damage caused by seismic loads, and one of them is to concentrate the damages on the designated region or members. The reduced beam section connection, also known as the dogbone connection, is a promising option for improving the ductility of steel beam to column moment connections, especially in high-risk regions. By symmetrically trimming the width of the beam flanges over a discreet length in the vicinity of the beam ends, a ductile fuse can be created to accommodate the inelasticity that is required for seismic energy dissipation while is not only protecting the beam to column connection but also prevent causing the catastrophic and progressive collapse of the structure. This paperchr(chr('39')39chr('39'))s emphasis is the performance of the steel portal frame with RBS connections based on detail provided by AISC specification. The concentration of plastic deformations in the RBS region under cyclic load causes intensified stresses that accumulate damage. The prediction of ductile damage and fracture is one of the most important challenges in many engineering applications. Damages in a structure are caused by material degradation due to initiation, growth, and coalescence of microcracks/voids in a real-life material element from monotonic, cyclic/fatigue, or dynamic/explosive impact loading. The damage evolution law describes the rate of degradation of the material stiffness once the corresponding initiation criterion has been reached. In this study, the ductile damage model presented for steel is used. Damage Initiation parameters and damage evolution rules were obtained based on standard tensile test from literature and software procedure analysis. A coupon model has been established based on the standard tensile test to evaluate the ductile damage model. Also, to validate the steel portal frame with the RBS connection model two-step has been considered. In the first step, the global response of the steel moment frame was validated based on Wakabayashichr(chr('39')39chr('39'))s test. Also validation of the RBS connection model was checked based on Pachoumis experiments in the next step. Then, according to AISC 360 steel and AISC 341 steel, a steel moment frame design with RBS connection was designed. By selecting and extracting a single-span portal frame, the effect of considering damage was investigated by finite element analysis. Initial geometrical imperfections were determined using the AISC 360 Recommendation for out-of-plumbness, out-of-straightness, and localized geometrical defects. The cyclic displacement amplitude followed the loading protocol in the ATC-24. The study results show in the elastic region the behavior of the frame remains unchanged before the frame reaches the high amplitude cycle. But gradually, with increasing cycles, the size of the hysteresis loop and ultimate resistance became smaller. Thereby, if the aim is to focus on the load levels that lead to large localized plastic deformations, it is critical to consider the damage parameters to improve the reliability of the results. Measurement of the area below the graph in the last loading cycle shows that the dissipated energy in the two cases without vertical load and with a vertical load on the columns is decreased by 2.6% and 4.1%, respectively. The continued deterioration of the RBS region due to damage spreads leads to complete frame failure, which is not properly predicted when damage parameters are ignored.

As Methotrexate (MTX) may induce liver side effects or damage, evaluating the liver of the consumers of this drug by a noninvasive method, such as FibroScan, may be effective.
The present study aimed at evaluating the progression of liver fibrosis and steatosis using the transient elastography (FibroScan) technique in patients, who are treated with MTX.
One hundred and one patients, who were treated with MTX because of different rheumatologic diagnosis and/or dermatologic disease, were included in the study. Liver stiffness was measured using FibroScan. Hepatic fibrosis was identified by converting the FibroScan results measured in kPa to the Metavir scale. Also, F0-F4 and steatosis were graded.
The assessment of steatosis using FibroScan showed mild, moderate, and severe stenosis in 15.8%, 13.9%, and 26.7%, respectively. With regards to grading of hepatic fibrosis, 67.0% were graded as F0 to F1, 7.0% as F2, 7.0% as F2 to F3, 2.0% as F3, 11.0% as F3 to F4, and 6.0% as F4. A significant association was found between body mass index, waist circumferences, and fibrosis. The association between the severity of hepatic fibrosis and indices of alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), and serum albumin was significant. No relationship was revealed between the severity of hepatic fibrosis and MTX dosage as well as duration of MTX use.
The authors found significant associations between hepatic steatosis and anthropometric parameters, level of albumin, drug dosage higher than 10 mg, and cumulative dosage of MTX. The severity of hepatic fibrosis and steatosis induced by MTX was mainly affected by the patients’ obesity.

Background and Pre-eclampsia is one of the most common syndromes associated with pregnancy. Severe hypertension, eclampsia and other pathological disorders are the predictable outcomes of this syndrome among high risk pregnant women. Pre-eclampsia accompanied by bleeding and infection is considered as a leading cause of death in pregnant women worldwide. Early diagnosis of this syndrome can help physicians in choosing more effective treatment options. In a prospective research we aimed to determine the sensitivity, specificity and the relationship between different factors in utrine artries among high risk pregnant women. G50 Ultrasound was used on 100 pregnant women fitting our inclusion criteria. Data was analyzed in SPSS V…... The mean age of patients was 23.2±4.1 years old and their mean BMI was 23.2±5.4. There were four patients (4.7%) with history of pre-eclampsia and one (1.1%) with diabetes. Pre-eclampsia occurred in 10 patients which was severe in two and mild in eight cases. The sensitivity and specificity of PI and RI values were found to be higher in first trimester and second trimester, respectively. This study found Doppler Ultrasound as an effective standard diagnostic method in diagnosis of pre-eclampsia in high risk pregnancies. These findings need to be assessed in different samples before we can generalize it to other population.

Background and Today Assisted Reproductive Techniques (ART) are widely applied in Islamic countries according to religious rules. This study aimed at investigating the attitudes of infertile women towards oocyte donation who referred to an infertility clinic in Sari. Oocyte Donation Questionnaire was used to collect the data from infertile women attending Imam Khomeyni IVF Centre in 2012-2013. There was a significant difference between the level of education and positive attitude in accepting oocyte donation. Among the participants 78.4% were willing to receive oocytes from anonymous donors and 22.3% said that they would tell the truth to the baby born via egg donation. There were 73.3% who found this technique contrary to Islamic beliefs. More attention is needed on social and economic issues affecting the attitudes of people towards oocyte donation. Significant correlation between the level of education and positive attitude towards oocyte donation calls for holding more educational classes and conferences and informing the public through mass media. These, could also increase the religious knowledge of people towards the benefits of this technique.

Cigarette smoke contains a considerable number of dangerous chemicals which are toxic to all parts of human body، especially to oral cavity. Human saliva is the first line of defense that encounters these toxic agents. Therefore، saliva could be thought as a non-invasive research tool to monitor alternations in biochemistry of body fluids due to toxic chemicals. The aim of this research was to investigate the effect of cigarette smoke on activity of enzymatic antioxidants of saliva including peroxidase and superoxide dismutase. In practical section، a group of 20-25 years old smoker men entered the study and their salivary antioxidants were compared with a similar group of non-smokers. Un-stimulated saliva was collected in sterile tubes and kept frozen at -70°C after being centrifuged. The activity of peroxidase and superoxide dismutase was the measured using their specific substrates under assay conditions. The results showed that، within experimental errors، the activity of peroxidase was decreased significantly in the smoker group (P≤0. 001) as compared to non-smokers. Super oxide dismutase was also less active in the saliva of smokers. It is suggested that toxic chemicals in cigarette smoke could have acted as inhibitors of mentioned enzymes in saliva of smokers. A significant decrease in saliva flow rate and pH was also observed among smokers with respect to non-smokers. Calling the important contributing role of antioxidant enzymes in the defense system of saliva opens a novel new insight into smoking habit.