A theoretical investigation of the presence of the azimuthal backward waves (ABWs) and their amplification in a magnetized plasma waveguide with two annular rotating energy sources

In this paper, the azimuthal backward waves (ABWs) in a magnetized plasma waveguide are studied. The waveguide is made of the loss-free metallic cylindrical wall and a dielectric annular layer and a magnetized plasma column in it. There are two annular rotating electron beams as the energy sources in the waveguide. The inner annular rotating electron beam (IAREB) is in the plasma region and the outer annular rotating electron beam (OAREB) is on the dielectric layer. The generation of ABWs as a possible consequence of the presence of two annular electron beams is proved by using Poynting’s theorem in the mentioned configuration. Also, it is observed that the width of allowed and forbidden frequencies of ABWs in the considered waveguide can be enhanced and shifted to the higher frequency side by changing the fundamental physical parameters. In addition, the effective factors on the frequency spectrum and growth rate of ABWs such as the geometric dimensions, the dielectric constant of the dielectric layer and electron plasma frequency of the annular electron beams are studied

Use of PCR to Detect Mycoplasma hominis and Ureaplasma urealyticum from Semen Samples of Infertile Men who Referred to Royan Institute in 2009

Objective: Infection with genital Mycoplasmas may have harm effects on the reproductivehealth of men, thus leading to male infertility. This study was performed to detectthe prevalence of these bacteria and to study the sperm parameters in infertile men whoreferred to Royan Institute during 2009.Materials and Methods: Semen samples were collected from 220 infertile men and dividedinto three sections. The first section was used for semen analysis, the second sectionfor polymerase chain reaction (PCR) in which U4 and U5 primers were used for theamplification of the urease gene of U. urealyticum, and RNAH1 and RNAH2 primers wereused for amplification of the 16S rRNA gene of M. hominis.Results: From a total of 220 semen samples cultured, 15.5% of M. hominis and 40.5% ofU. urealyticum were isolated. Evaluation of semen parameters showed a lower pH in theU. urealyticum positive group and the group which was positive for both bacteria, ratherthan the group which contained no bacteria (p=0.007 and p=0.000, respectively). Also,the mean sperm motility was lower in the group which was positive for both bacteria whencompared with the U. urealyticum positive group (p=0.009).Conclusion: The results of this study show that a high percent of infertile men are infectedwith these bacteria which may lead to pelvic inflammatory disease (PID) and infertility,thus isolation of these bacteria in infertile couples with no clinical symptoms is necessaryand can be a part of a sexual transmitted disease (STD) control program

Successful prevention of tunneled, central catheter infection by antibiotic lock therapy using cefotaxime

Background: Chronic hemodialysis patients frequently require vascular access through central venous catheters (CVCs). The most significant complication of these catheters is infection. This risk can be lowered by the use of an antibiotic-Heparin lock. This study focuses on hemodialysis patients using Tunneled-cuffed catheters (TCC), to assess the rate of catheter-related infections (CRI) in catheter-restricted filling with Cefotaxime and Heparin in end stage renal disease patients. Methods: A double-blind randomized study was conducted to compare 5000 U/ml Heparin plus10 mg/ml cefotaxime (CE/HS) as catheter-lock solutions, with Heparin (5000 U/ml) alone. A total of 30 patients with end-stage renal disease and different etiologies, were enrolled for chronic hemodialysis with permanent catheters from December 2009 to March 2010. These patients were randomly assigned to two groups of 15 members. Blood samples were collected for culture, sensitivity, and colony count, from the catheter lumen and the peripheral vein. CRI was considered as the end point. Results: The rate of CRI was significantly lower in the cefotaxime group versus control group (p < 0.001). No exit site infection was occurred in both groups. Infection-free survival rates at 180 days were 100% for the CE/HS group, and 56% for the HS group. Conclusions: Antibiotic lock therapy using cefotaxime reduces the risk of CRI in hemodialysis patients