Tunneling in a Cosmological Model with Violation of Strong Energy Condition

The tunneling rate, with exact prefactor, is calculated to first order in \hbar for a closed FRW universe filled with perfect fluid violating the strong energy condition. The calculations are performed by applying the dilute-instanton approximation on the corresponding Duru-Kleinert path integral. It is shown that a closed FRW universe filled with a perfect fluid with small violation of strong energy condition is more probable to tunnel than the same universe with large violation of strong energy condition.Comment: 11 pages, LaTe

Role of cathepsins in Alzheimer's disease: A systematic review

Alzheimer's disease (AD) is a multifactorial disease. In addition to the precipitating of two proteins beta-amyloid peptide and neurofebrillary tangles, which are the main mechanisms involved in the pathogenesis of AD, other factors such as inflammatory mechanisms and changes in lysosomal enzymes play an important part in the pathogenesis of this disease. Increased and decreased lysosomal proteases, such as cathepsin, can lead to functional impairment and gradual death of neurons. The aim of this review was to investigate the role of cathepsins in the pathogenesis of AD. To conduct this review, relevant articles published between 2000 and 2016, and indexed in reliable databases including PubMed, Google Scholar, Scopus and Web of Science were retrieved. After reviewing the articles, 30 articles that directly addressed the subject of this review were included in final analysis. Cathepsins exacerbate intracellular conditions in neurons, by processing beta-amyloid precursor protein and converting it into amyloid beta. They also play a protective role against AD and fight it by catalyzing the decomposition of beta-amyloids and converting them into the cut out forms of the carboxyl C-terminus. In addition, the 24 kDa fragment resulting from the effect of cathepsin D on apolipoprotein E (ApoE) is the second binding to the receptor in the ApoE. This fragment may also be the cause of the pathogenicity of Apo E in AD. Identifying and explaining the mechanisms involved in the pathogenesis of AD can play a significant role in the prevention and treatment of this disease. Since cathepsins play a pivotal role in the decomposition of beta-amyloid and reduction of the risk of AD, further studies can be considered an effective approach to study AD

Antimicrobial susceptibility patterns of the gram-negative bacteria isolated from septicemia in Children?s Medical Center, Tehran, Iran

Introduction. The choice of antimicrobial treatment for septicemia is often empirical and based on the knowledge of local antimicrobial activity patterns of the most common bacteria causing such bloodstream infections. The current study aimed to study the prevalence of bacterial pathogens causing septicemia and their antimicrobial resistant profiles in hospital admitted patients. Methods. This cross sectional study done at Children?s Medical Center, Tehran, Iran. We examined 168 bacterial strains isolated from 186 clinically diagnosed septicemia cases refereed at Children?s Medical Center, Tehran, Iran Over a period of twelve months from July 2010 to 2011 July. 11446 blood samples from patients of clinically suggestive septicemia were evaluated. Results. Bacterial strains were isolated from 910 (7.95%) of blood cultures. Gram-negative bacteria identified were Pseudomonas species (20.5%), Pseudomonas aeruginosa (1.86%), Salmonella spp (1.09%), Acinetobacter naumannii (8.13%), Escherichia coli (4.06%), Klebsiella spp (5.16%). Gram-negative pathogens were more than gram positive in bloodstream infections. Antimicrobial susceptibility testing was done according to Clinical and Labo- ratory Standards Institute (CLSI, USA) guidelines against: amikacin ampicillin, amoxicillin, amoxiclav, cefuroxime, cefotaxime, ceftazidime, cefoperazone tetracycline, chloramphenicol, ciprofloxacin, gentamicin. Resistanc to different antibiotics in the most important isolated bacteria were: 32.1 %, 10.8%, 87.8%, 96%, 39.1%, 35.2, 49.4%, 69%, 80.02%, 22%, 59%, 30.1% respectively, for Pseudomonas spp, 32%, 3.7%, 84.2 %, 83.2%, 80.1%, 75.4%, 44.8%, 45.2%, 33.3%, 19%, 34.1, 11.5% respectively for Acinetobacter species. Discussion. Resistant to majority of the antimicrobial agents for several pathogens implicated in bloodstream infections, particularly in Gram-negative bacteria, can make complication in treatment of infection cause by them