368 research outputs found

    Proliferating cell nuclear antigen as a molecular biomarker for spermatogenesis in PTU-induced hypothyroidism of rats

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    The thyroid hormone has few serious effects on the testes except during the neonatal stage. There is little knowledge concerning the prolonged effect of thyroid hormone deficiency throughout the rat’s life span and its effect on spermatogenesis. Proliferating cell nuclear antigen (PCNA) is a nuclear matrix protein, which is essential for multiple cell cycle pathways. Here we used PCNA immunohistochemistry as a marker to differentiate between the testes of control and hypothyroid rats. About 20 rats were equally divided into 2 groups; the first group was the control group, while the second group was the experimental group in which rats were fed 0.05% 6-n-propyl thiouracil (PTU) in drinking water for 6 weeks. Immunohistochemistry, using an antibody against PCNA, showed at least 3 differences in the pattern of PCNA immunoreactivity (PCNA-ir). First, PCNA-ir was not detected in Sertoli and Leydig cells in the testes of control rats and detected in some of the hypothyroid rats. Second, in the control group more than 96% of spermatogonia were PCNA-positive cells; however, hypothyroidism caused the reduction to approximately 25% PCNA staining in spermatogonia. The third difference was in the abnormal distribution of spermatogonia seen in the hypothyroid rat testis, not in the control one. These results suggest that prepubertal hypothyroidism affects the proliferation of spermatogenic cells leading to impaired spermatogenesis and that PCNA index is a useful marker for assessing germ cell kinetics and spermatogenesis in prepubertal hypothyroidism

    Entropy generation for MHD natural convection in enclosure with a micropolar fluid saturated porous medium with Al2O3Cu water hybrid nanofluid

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    This contribution gives a numerical investigation of buoyancy-driven flow of natural convection heat transfer and entropy generation of non-Newtonian hybrid nanofluid (Al2O3-Cu) within an enclosure square porous cavity. Hybrid nanofluids represent a novel type of enhanced active fluids. During the current theoretical investigation, an actual available empirical data for both thermal conductivity and dynamic viscosity of hybrid nanofluids are applied directly. Numerical simulation have been implemented for solid nanoparticles, the volumetric concentration of which varies from 0.0% (i.e., pure fluid) to 0.1% of hybrid nanofluids. Heat and sink sources are situated on a part of the left and right sides of the cavity with length B, while the upper and bottom horizontal sides are kept adiabatic. The stated partial differential equations describing the flow are mutated to a dimensionless formulas, then solved numerically via the help of an implicit finite difference approach. The acquired computations are given in terms of streamlines, isotherms, isomicrorotations, isoconcentraions, local Began number, total entropy, local and mean Nusselt numbers. The data illustrates that variations of ratio of the average Nusselt number to the average Nusselt of pure fluid Num+ is a decreasing function of Ha and φ, while e+ is an increasing function of Ha and φ parameters of hybrid nanofluid

    Epidemiologic characteristics of Klebsiella pneumoniae isolates in ventilator-associated pneumonia in intensive care units

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    Klebsiella pneumoniae is a common pathogen that causes ventilator associated pneumonia (VAP) in intensive care units (ICUs). Strain typing is a useful tool in tracking the spread of these infections. Primary objective was to study different strains causing VAP in Anesthesia ICUs. Secondary objective was to determine role of health-care workers (HCWs) and ICU environment in the transmission of these strains. Endotracheal aspirates of 60 VAP patients, surveillance samples from the HCWs (18 )and the ICU environment (193)were collected. Antibiogram typing and enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) were used for comparison of the isolates from VAP patients and surveillance samples. Antibiogram showed 5 antibiotic susceptibility patterns that were designated A1-A5. ERIC-PCR yielded 1 to 5 amplification bands. All the isolates were typable by ERIC-PCR. Eight ERIC patterns were obtained ERIC(I)-ERIC(VIII). ERIC-PCR typing method gave higher discriminatory index (D) (0.7557) than antibiogram (0.6035). There was sharing of certain ERIC patterns among patient and HCWs or environmental sources. In Conclusion: K.pneumoniae is the most dominant pathogen in anesthesia ICUs. Throats and hands of HCWs are possible sources of pathogen transmission to patients. Surfaces with hand contact of the medical staff are often contaminated and may serve as vectors for cross transmission.Keywords: Ventilator-associated pneumonia, ICU environment, health-care workers, Klebsiella pneumoniae, antibiogram typing, ERIC-PC

    The incidence of prostate cancer in Iran: Results of a population-based cancer registry

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    Background: Little is known about the epidemiology of prostate cancer in Iranian men. We carried out an active prostate cancer surveillance program in five provinces of Iran. Methods: Data used in this study were obtained from population-based cancer registries between 1996 and 2000. Results: The age-standardized incidence rate of prostate carcinoma in the five provinces was 5.1 per 100,000 person-years. No significant difference was seen in the age-standardized incidence rate of prostate cancer within the provinces studied. The mean±SD age of patients with prostate cancer was 67±13.5 years. Conclusion: The incidence of prostate cancer in Iran is very low as compared to the Western countries. This can partly be explained by lack of nationwide screening program, younger age structure and quality of cancer registration system in Iran

    Characteristics of air and oxy-fuel combustion in micro-channels

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    With the fast development of MEMS (micro electro mechanical systems) devices the demand for miniaturized power source is increasing quickly. A micro-combustor is one of the key components of these devices in which the fuel-air mixture is burnt. In the past few years, intense research efforts have been made on catalytic micro-reactors using hydrocarbons as fuel for a variety of portable power production systems. The applications of these micro-reactors include scaled-down thermal engines, wherein a catalytic micro-burner is used for the direct conversion of chemical energy to thermal energy, catalytic micro-thrusters for space applications, and micro-reactors used for fuel reforming in micro solid oxide fuel cells. The present work is aimed at developing Computational Fluid Dynamics (CFD) approach for the investigation of characteristics of air and oxy-fuel combustion in micro-channels. The simulations are based on the numerical solution of the conservation of mass, momentum, energy and species equations of two dimensional flows. The present work as being related to micro-channels will provide a basis for development of new technologies such as carbon-free combustors for use in gas turbines and boilers in order to reduce carbon dioxide emissions.Paper presented to the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.dc201

    Preparation of Silver Nanoparticles by Chemical Reaction Method at Different Reaction Temperatures and the Study of their Antibacterial Activity

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    It is found silver nanoparticles have strong antibacterial activity due to use in medical applications. It can be tuned antibacterial activity through control the shape and size of the synthesized silver nanoparticles. This article, silver nanoparticles were produced as different sizes at different reaction temperatures by chemical reaction method. Morphology and structure have been characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD) and UV-Visible Spectroscopy. Results indicate that silver nanoparticles have different sizes in range of (30- 97.26 nm). Additionally, antibacterial activity test against the pathogens, namely Escherichia colis hows effective inhibitory activity

    Impact on plant productivity under low-fertility sandy soil in arid environment by revitalization of lentil roots

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    Lentil is one of the essential legume crops, which provides protein for humans and animals. This legume can improve soil fertility through nitrogen fixation, which is imperative in low-fertility soils. The growth and productivity of lentil could be enhanced through improving nutrition and root revitalization. Therefore, the objective of this study was to assess the impact of root activator (RA) and phosphorus (P) application on morphological, physiological, agronomic, and quality traits of lentil under newly reclaimed low-fertility sandy soil in an arid environment. The RA was applied at four levels of 0 (RA0-untreated control), 1.25 (RA1), 2.5 (RA2), and 3.75 (RA3) l ha–1. RA contained 9% potassium humate, 1,600 ppm indole butyric acid, 200 ppm gibberellic acid, and 200 ppm naphthalene acetic acid. The recommended rate of phosphorus (P) fertilization in the newly reclaimed low-fertility sandy soil (75 kg P2O5 ha–1) was applied, and its amount was increased and decreased by 25 kg P2O5 ha–1 vs. non-added control. Thus, P rates were applied at four rates 0 (P0; control), 50 (P1), 75 (P2), and 100 (P3) kg phosphorus pentoxide (P2O5) ha–1. Our results revealed that treated lentil plants with the high levels of both treatments (RA3 and P3) exhibited superiority in root measurements (root length, total number of nodules plant−1, number of active nodules plant−1, dry weights of active nodules, and total root), nitrogenase activity, chlorophyll a and b, carotenoids, yield traits, and seed proteins and carbohydrates. However, the recommended P level (75 kg P2O5 ha–1, P2) under the high level of RA (3.75 l ha–1, RA3) displayed non-significant differences in yield traits (plant height, 1,000-seed weight, seed yield ha–1) and quality traits (protein and carbohydrate) with the high P level (100 kg P2O5 ha–1, P3). Accordingly, its recommended economically and environmentally to use this coapplication of RA3 and P3 in low-fertility soil for better lentil growth, and seed yield and quality

    Drug-related mutational patterns in hepatitis B virus (HBV) reverse transcriptase proteins from Iranian treatment-Naïve chronic HBV patients

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    Background: Immunomodulators and Nucleotide analogues have been used globally for the dealing of chronic hepatitis B virus (HBV) infection. However, the development of drug resistance is a major limitation to their long-term effectiveness. Objectives: The aim of this study was to characterize the hepatitis B virus reverse transcriptase (RT) protein variations among Iranian chronic HBV carriers who did not receive any antiviral treatments. Materials and Methods: Hepatitis B virus partial RT genes from 325 chronic in active carrier patients were amplified and directly sequenced. Nucleotide/amino acid substitutions were identified compared to the sequences obtained from the database. Results: All strains belonging to genotype D.365 amino-acid substitutions were found. Mutations related to lamivudine, adefovir, telbivudine, and entecavir occurred in (YMDD) 4% (n = 13), (SVQ) 17.23% (n = 56), (M204I/V + L180M) 2.45% (n = 8) and (M204I) 2.76% (n = 9) of patients, respectively. Conclusions: RT mutants do occur naturally and could be found in HBV carriers who have never received antiviral therapy. However, mutations related to drug resistance in Iranian treatment-naïve chronic HBV patients were found to be higher than other studies published formerly. Chronic HBV patients should be monitored closely prior the commencement of therapy to achieve the best regimen option. © 2013, KOWSAR Corp

    Characteristics of oxyfuel and air fuel combustion in an industrial water tube boiler

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    Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.dc201

    Entanglement entropies in free fermion gases for arbitrary dimension

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    We study the entanglement entropy of connected bipartitions in free fermion gases of N particles in arbitrary dimension d. We show that the von Neumann and Renyi entanglement entropies grow asymptotically as N^(1-1/d) ln N, with a prefactor that is analytically computed using the Widom conjecture both for periodic and open boundary conditions. The logarithmic correction to the power-law behavior is related to the area-law violation in lattice free fermions. These asymptotic large-N behaviors are checked against exact numerical calculations for N-particle systems.Comment: 6 pages, 9 fig
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