An echocardiographic study of heart in a group of male adult elite athletes

Background: Severe and prolonged physical training is associated with morphological and physiological cardiac changes, often termed as the "athlete's heart". Echocardiographic features peculiar to elite Iranian athletes have not been previously described. The aim was to examine the echocardiographic characteristics of highly trained Iranian athletes involved in three different sports. Methods: We studied cardiac morphology and function as assessed by rest echocardiography in 50 elite adult male athletes referring to a university hospital in Tehran between February 2001 and March 2006 Resting ejection fraction, interventricular septal wall thickness (IVSWT), left ventricular posterior wall thickness (LVPWT), left ventricular internal end diastolic dimension (LVEdD), left ventricular internal systolic dimension (LVIsD), left ventricular (LV) mass, and relative wall thickness (R W7) were measured The control group consisted of 50 age- and weight-matched normal healthy men. Results. Of the athletes, 38 were engaged in predominantly dynamic (running and soccer) and 12 in predominantly static (weightlifting) sports. The overall mean LVEdD (5I.06±5.49mm) and IVSWT (10.24±1.43mm) were higher in the athletes than those in the normal subjects. The mean of IVSWT in the 38 endurance-trained athletes was significantly more than that of the 12 strength-trained athletes (11.1 mm vs. 10.3 mm, P<0.05). LVEdD was also greater in the endurance-trained athletes, but he difference was not statistically signficant (51.2 mm vs. 50.6 mm). Conclusion: Our results of higher LVEdD and IVSWT in Iranian male athletes are in line with previous reports. To generalize the results, we require more studies with larger sample sizes (with female athletes included)

بكارگيري متدولوژي مناسب بودن براي سرويس (FFS (در خطوط لوله با عيوب خوردگي از نوع كاهش موضعي ضخامت

Fitness for Service (FFS) methodology assessment of defective pipes and pressure vessels in oil and gas industries is offered in API- 579 standard. The defective pipes operation are allowed just if they have been evaluated based on FFS method and their operating pressure has been confirmed whether the defects caused by cracks or different corrosion types. Through the current study FFS evaluation procedure was benefited to find the safe operating pressure for a 16 inches defective pipe consisting a local metal loss defect (Max. depth of 8mm) with an internal pressure of 33 MPa. Furthermore, the time needed for the next FFS examination had been presented. The analyzed pipe was about 4 years in service and is located in an injection line of a natural gas reservoir. The required experimental data related to the thickness of this pipe were collected using phased array ultrasonic test on the operating site. The results indicated that the defective pipe could operate well in service for next two years without any demands for repair or replacement

Numerical and experimental investigation on boding strength optimization of glass fibers-reinforced epoxy composites on a structural steel substrate

Incidence of breaks and leakages in fluid transportation pipes is a common issue in Iran. Depending on the type of pipes and environmental conditions, the breaks in the pipes may be caused by different factors, including mechanical damages, internal or external corrosions, failures, or applied stresses. In the repair of damaged pipes, there are several strategies for rebuilding and implementing the pipeline, most of which are replacing the entire exhausted pipe, using weld clamps and using composite patches. In recent years, the use of composite patches has been accepted as a low-cost, permanent, and standard method for different pipe sections with the least interruption in transportation. In the present study, the boding strength of glass fibers-reinforced epoxy composite patches on a structural steel substrate were investigated and optimal conditions of achieving enhanced adhesion strength of composite patches on the steel substrate were determined, using the Tagochi method at various curing temperatures and times. In this regard, the tensile and shear strength of epoxy, cyanoacrylate, and methacrylate-based glues as three kinds of appropriate polymers for bonding the epoxy composite on the steel substrates were tested. The mechanical strength measurements and fractured interfaces evaluations using a scanning electron microscopy (SEM) revealed that the methacrylate-based glue has the better adhesion strength to the steel substrate

A comprehensive systematic review of the effectiveness of Akkermansia muciniphila, a member of the gut microbiome, for the management of obesity and associated metabolic disorders

Aims and background: Obesity is recognised as a significant public health burden worldwide. Recently the cross-talk between gut microbiota and obesity has attracted much attention. To that end, Akkermansia muciniphila has been proposed as a promising microbe to manage obesity. In the present systematic review, we evaluated evidence on the effectiveness and mechanisms of action of Akkermansia muciniphila supplementation in the management of obesity. Methods: Electronic databases of MEDLINE, PubMed, Scopus, Web of Science, and Google Scholar were searched thought March 2020 to identify relevant published articles, and eligible articles were systematically reviewed. Results and conclusions: Fifteen studies were included in the present study. Findings from the present review, which included human and animal (rodent) models support the effectiveness of Akkermansia supplementation as a novel therapeutic approach for the management of obesity and metabolic complications associated with obesity. However, future clinical trials are warranted to verify these outcomes. © 2021 Informa UK Limited, trading as Taylor & Francis Group

Study of tribological properties of bulk nanostructured aluminum and copper samples applicable in automotive bearing application

Using lightweight systems and friction reduction approaches are two main contributors towards modern and efficient powertrains in the automotive industry. New materials and processes are required to achieve the demanding and ever-increasing performance requirement of automotive systems. Nanostructure induced by Severe Plastic Deformation (SPD) methods involves bimodal microstructures and hence, shows exceptional mechanical characteristics which can be exploited for automotive application. Through this study, pure copper, and aluminum alloy samples (series7000) were processed to attain bulk nanostructured samples using a Single Step High Pressure Torsion technique with appropriate dimensions applicable as the rolling elements of automotive bearings. The induced nanostructures resulted micro hardness and frictional characteristics of the bulk samples were assessed using transmission electron (TEM) and atomic force (AFM) microscopies as well as microhardness evaluations. The results revealed that a fully refined nanostructured samples were achieved with 90% increase in the hardness at the outer diameter of the sample. The AFM measurements indicated that the friction coefficient of nanostructured copper and aluminum samples were ~25% and ~45% less than that of both the unprocessed samples, respectively. Characteristics of treated samples suggest that these processes can be potentially used in demanding conditions of rolling element bearings with reduced weight and frictional losses.</p