We derive a microscopic expression for the mechanical pressure P in a system of spherical active Brownian particles at density ρ. Our exact result relates P, defined as the force per unit area on a bounding wall, to bulk correlation functions evaluated far away from the wall. It shows that (i) P(ρ) is a state function, independent of the particle-wall interaction; (ii) interactions contribute t...

Colonic motor activity was initiated by infusions of bile salts into the caecum or rectum of the anaesthetized rabbit. Primary bile acids were examined proximally and distally in the colon and elicited marked motor responses. Sinc dihydroxy bile acids are known to be potent inhibitors of electrolyte and water absorption in the colon, the secondary bile acid deoxycholic acid, the dihydroxyl comp...

Bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) is an intracellular second messenger that regulates adaptation processes, including biofilm formation, motility, and virulence in Gram-negative bacteria. In this study, we have characterized the core components of a c-di-GMP signaling pathway in the model Gram-positive bacterium Bacillus subtilis. Specifically, we have directly identified and characteri...

Emerging concepts for on-chip biotechnologies aim to replace microfluidic flow by active, molecular-motor driven transport of cytoskeletal filaments, including applications in bio-simulation, biocomputation, diagnostics, and drug screening. Many of these applications require reliable detection, with minimal data acquisition, of filaments at many, local checkpoints in a device consisting of a po...

this research was carried out to investigate the effects of various levels of dietary organic selenium supplementation (0, 0.1,  0.2 and  0.3 mg/kg) on reproductive traits of rooster. semen was collected using abdominal massage and samples were mixed together. sperm characteristics including percentage of motile, viable and abnormal sperms were assessed. this experiment was carried out based on...

background: anti-sperm antibody (asa) can decrease sperm motility and, therefore, it is a cause of male infertility. the aim of this study was to evaluate the effects of varicocelectomy on anti-sperm antibody in patients with varicocele. methods: this observational study was conducted on 90 patients with varicocele at sina and imam khomeini hospitals during 2006 to 2009. all varicocelectomy can...

objective(s) achillea genius is widely used in traditional medicine for gastrointestinal disorders. the aim of this study was to investigate the effects of aqueous-ethanol extract of achillea wilhelmsii on rat’s gastric motility in basal and vagal stimulated conditions. materials and methods twenty four wistar rats were randomly divided into two groups: control and test. the extract was prepare...

background: pentoxifylline (px) prevents camp breakdown by inhibiting the activity of the camp-phosphatase and presumably, stimulates sperm motion. incubation with px causes hyperactivation of sperm, an important step in achieving fertilization, and leads to changes in membranes associated with sperm capacitation. objective: the purpose of this study was to examine the effects of pentoxifylline...

oxidative stress has been identified as a crucial factor leading to male infertility largely due to peroxidativedamage to the sperm cell membrane. cadmium (cd) is a widespread environmental pollutant and oneof the well-known reproductive toxicants. because of its long biological half-life (10–30 years), cdaccumulates in the biological systems. the present study was designed to assess the concen...

The membrane protein FlhB is a highly conserved component of the flagellar secretion system, and it plays an active role in the regulation of protein export. In this study conserved properties of FlhB that are important for its function were investigated. Replacing the flhB gene (or part of the gene) in Salmonella typhimurium with the flhB gene of the distantly related bacterium Aquifex aeolicu...