213 research outputs found
Effect of vitamin C and quercetin treatment on the liver histopathologic profile in congenital lead exposed male rat pups
Introduction: Lead is one of the most important environmental pollutants due to its vast use in various industries. Lead accumulation in different organs, especially the brain, liver and kidneys can cause serious health problems. Lead exposure is more dangerous during fetal period and childhood. Materials and Methods: Timed pregnant female rats divided into 6 groups. Group 1served as control group and received tap water, group 2 received 500 mg/liter lead acetate in the drinking water from 5th day of gestation up to 25th day post-partum, group 3 received the same dose of lead acetate along with daily IP injection of 40mg/kg quercetin, Group 4 received the same dose of lead acetate along with 2g/liter vitamin C, groups 5 and 6 received vitamin C and quercetin respectively like groups 2 and 3 but without lead acetate. On the 25th day postpartum, 6 male pups in each group were deeply anesthetized by chloroform; livers were removed and processed for Hematoxyline- Eosin staining. The microscopic slides were photographed and liver tissue morphological characteristics were evaluated. Results: Lead exposure caused extensive histopathologic changes in liver tissue including hepatocyte degradation, cell nucleus bifurcation and inflammation around hepatic veins. Quercetin and vitamin C treatment could prevent these pathologic changes to a considerable extent. Conclusion: Vitamin C in drinking water and quercetin via IP injection could protect the liver tissue against lead hepatotoxic effects. © 2015, Iranian Society of Physiology and Pharmacology. All rights reserved
The largest subunit of human RNA polymerase III is closely related to the largest subunit of yeast and trypanosome RNA polymerase III
In both yeast and mammalian systems, considerable progress has been made toward the characterization of the transcription factors required for transcription by RNA polymerase III. However, whereas in yeast all of the RNA polymerase III subunits have been cloned, relatively little is known about the enzyme itself in higher eukaryotes. For example, no higher eukaryotic sequence corresponding to the largest RNA polymerase III subunit is available. Here we describe the isolation of cDNAs that encode the largest subunit of human RNA polymerase III, as suggested by the observations that (1) antibodies directed against the cloned protein immunoprecipitate an active enzyme whose sensitivity to different concentrations of alpha-amanitin is that expected for human RNA polymerase III; and (2) depletion of transcription extracts with the same antibodies results in inhibition of transcription from an RNA polymerase III, but not from an RNA polymerase II, promoter. Sequence comparisons reveal that regions conserved in the RNA polymerase I, II, and III largest subunits characterized so far are also conserved in the human RNA polymerase III sequence, and thus probably perform similar functions for the human RNA polymerase III enzyme
Cosmological expansion and contraction from Pauli exclusion principle in -branes
We show that the Pauli exclusion principle in a system of -branes can
give rise to the expansion and contraction of the universe which is located on
an -brane. We start with a system of -branes with high symmetry, which
join mutually and form pairs of -anti--branes. The resulting symmetry
breaking creates gauge fields that live on the -branes and play the role of
graviton tensor modes, which induce an attractive force between the and
anti- branes. Consequently, the gauge fields that live on the -branes,
and the scalar fields which are attached symmetrically to all parts of these
branes, decay to fermions that attach anti-symmetrically to the upper and lower
parts of the branes, and hence the Pauli exclusion principle emerges. By
closing -branes mutually, the curvatures produced by parallel spins will be
different from the curvatures produced by anti-parallel spins, and this leads
to an inequality between the number of degrees of freedom on the boundary
surface and the number of degrees of freedom in the bulk region. This behavior
is inherited in the -brane on which the universe is located, and hence this
leads to the emergence of the universe expansion and contraction. In this
sense, the Pauli exclusion principle rules the cosmic dynamics.Comment: 27 pages. arXiv admin note: text overlap with arXiv:1607.0149
Polylactide-co-glycolide nanoparticles for controlled delivery of anticancer agents
The effectiveness of anticancer agents may be hindered by low solubility in water, poor permeability, and high efflux from cells. Nanomaterials have been used to enable drug delivery with lower toxicity to healthy cells and enhanced drug delivery to tumor cells. Different nanoparticles have been developed using different polymers with or without surface modification to target tumor cells both passively and/or actively. Polylactide-co-glycolide (PLGA), a biodegradable polyester approved for human use, has been used extensively. Here we report on recent developments concerning PLGA nanoparticles prepared for cancer treatment. We review the methods used for the preparation and characterization of PLGA nanoparticles and their applications in the delivery of a number of active agents. Increasing experience in the field of preparation, characterization, and in vivo application of PLGA nanoparticles has provided the necessary momentum for promising future use of these agents in cancer treatment, with higher efficacy and fewer side effects
Effects of salinity on survival, growth, reproductive and life span characteristics of <i>Artemia</i> populations from Urmia Lake and neighboring lagoons
This study deals with effects of different salinities on the survival, growth, reproductive and lifespan characteristics of three Artemia populations from Urmia Lake and small lagoons at the vicinity of the lake under laboratory conditions. Experimental salinities ranged from 75 to 175 g L-1. Salinity was proved to have significant impact on the majority of the characters studied in this survey. Growth and survival in bisexual A. urmiana and parthenogenetic Artemia from Lake Urmia were significantly higher with respect to the parthenogenetic Artemia from lagoons at most of the salinities tested. Reproductive characteristics such as total number of broods, total offspring number of offspring in each brood and number of offspring at each day of reproductive period reduced with increasing salinity. Moreover higher salinity prolonged the pre-reproductive period but shortened the total reproductive period. Higher salinities also affected the percentage of encystment and post-reproductive period, showing significantly higher values in parthenogenetic populations in comparison to bisexual A. urmiana
Application of Industry 4.0 in the Procurement Processes of Supply Chains: A Systematic Literature Review
The fourth industrial revolution has significantly changed the traditional way of managing supply chains. The applications of Industry 4.0 (I4.0) technologies such as the Internet of Things (IoT) and Artificial Intelligence (AI) in different processes of supply chains have assisted companies to improve their performance. Procurement can be considered a critical process in supply chain management since it can provide novel opportunities for supply chains to improve their efficiency and effectiveness. However, I4.0 applications can be costly and may not be reasonably affordable. Therefore, the benefits of implementing these technologies should be clarified for procurement managers before investing in the digitalization of the procurement process. Despite the importance of this issue, few papers have attempted to address the effects of I4.0 technologies and smart systems in procurement. To fill this gap, a Systematic Literature Review (SLR) on the applications of I4.0 technologies in procurement has been used in this study. By reviewing 70 papers through appropriate keywords, a conceptual framework is developed to classify different value propositions provided by the different applications of I4.0 technologies in procurement processes. Results reveal nine value propositions that can provide a better understanding for the procurement department to analyze the benefits of implementing the related I4.0 technologies in different activities. Finally, findings and future study opportunities are concluded
Development of a KDP crystal growth system based on TRM and characterization of the grown crystals
A solution growth system has been built based on temperature reduction
method [1]. A few KDP crystals were grown by the system up to 160×40×38 mm
dimensions. Spectrophotometer transmission spectra from (100) planes of the grown
crystals show about 86 % transmission in the visible region. XRD analysis, laser damage
threshold, and microhardness of the crystals were determined. The etching behavior of
surface features of grown KDP single crystals was studied in different etchants
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