818 research outputs found
Herbal Remedies for Combating Irradiation: a Green Antiirradiation Approach
Plants play important roles in human life not only as suppliers of oxygen but also as a fundamental resource to sustain the human race on this earthly plane. Plants also play a major role in our nutrition by converting energy from the sun during photosynthesis. In addition, plants have been used extensively in traditional medicine since time immemorial. Information in the biomedical literature has indicated that many natural herbs have been investigated for their efficacy against lethal irradiation. Pharmacological studies by various groups of investigators have shown that natural herbs possess significant radioprotective activity. In view of the immense medicinal importance of natural product based radioprotective agents, this review aims at compiling all currently available information on radioprotective agents from medicinal plants and herbs, especially the evaluation methods and mechanisms of action. In this review we particularly emphasize on ethnomedicinal uses, botany, phytochemistry, mechanisms of action and toxicology. We also describe modern techniques for evaluating herbal samples as radioprotective agents. The usage of herbal remedies for combating lethal irradiation is a green antiirradiation approach for the betterment of human beings without high cost, side effects and toxicity
Removal of Chromium (III) from Aqueous Solution by Coconut Husk and Rice Straw
Coconut husk fibre and rice straw were found to be able to remove significant amount of Cr (III) ions from aqueous solutions. Its removal is a function of pH
and concentration. The optimum pH range for maximum uptake is between 4 and 6 for both substrates. The adsorption capacity was found to be 0.55 and
0.30 millimole Cr (III) / g substrate for coconut husk and rice straw respectively. The adsorption kinetic studies show that the removal process follows a first order rate expression. The breakthrough curves and adsorption efficiency of various columns containing mixed media of coconut husk/rice straw, soil and sand have been obtained. The results demonstrate that these agricultural
residues could be used as barriers in a landfill to maximize immobilization of toxic metal ions such as Cr (III) in leachates
Fundamental thickness limit of itinerant ferromagnetic SrRuO thin films
We report on a fundamental thickness limit of the itinerant ferromagnetic
oxide SrRuO that might arise from the orbital-selective quantum confinement
effects. Experimentally, SrRuO films remain metallic even for a thickness
of 2 unit cells (uc), but the Curie temperature, T, starts to decrease at 4
uc and becomes zero at 2 uc. Using the Stoner model, we attributed the T
decrease to a decrease in the density of states (N). Namely, in the thin
film geometry, the hybridized Ru-d orbitals are terminated by top and
bottom interfaces, resulting in quantum confinement and reduction of N.Comment: 20 pages, 4 figure
The Full Range of Predictions for B Physics From Iso-singlet Down Quark Mixing
We extend the range of predictions of the isosinglet (or vector) down quark
model to the fully allowed physical ranges, and also update this with the
effect of new physics constraints. We constrain the present allowed ranges of
sin(2*beta) and sin(2*alpha), gamma, x_s, and A_{B_s}. In models allowing
mixing to a new isosinglet down quark (as in E_6) flavor changing neutral
currents are induced that allow a Z^0 mediated contribution to B-Bbar mixing
and which bring in new phases. In (rho, eta), (x_s, sin(gamma)), and (x_s,
A_{B_s}) plots for the extra isosinglet down quark model which are herein
extended to the full physical range, we find new allowed regions that will
require experiments on sin(gamma) and/or x_s to verify or to rule out an extra
down quark contribution.Comment: 13 pages in RevTeX, 7 postscript figure
Androgen receptor genotyping in a large Australasian cohort with androgen insensitivity syndrome; identification of four novel mutations
We genotyped the androgen receptor (AR) gene in 31 Australasian patients with androgen insensitivity syndrome (AIS). The entire coding region of AR was examined including analysis of polymorphic CAG and GGN repeats in all patients. AR defects were found in 66.7% (6/9) of patients with complete AIS (CAIS) and 13.6% (3/22) of patients with partial AIS (PAIS). A novel deletion (N858delG) leading to a premature stop codon was found in CAIS patient P1. CAIS patient P2 has a novel deletion (N2676delGAGT) resulting in a stop at codon 787. These mutations would result in inactivation of AR protein. A novel insertion of a cysteine residue in the first zinc finger of the AR DNA-binding domain (N2045_2047dupCTG) was found in CAIS patient P3. PAIS patient P4 has a novel amino acid substitution (Arg760Ser) in the AR ligand binding domain, which may impair ligand binding. Five patients were found to have previously reported AR mutations and no mutations were identified in the remaining patients
SIP-based proactive and adaptive mobility management framework for heterogeneous networks
Abstract In this paper, we present and evaluate the performance of a mobility management system called the Proactive and Adaptive Handover (PAHO) system. PAHO is an application-level approach that uses SIP to manage client-initiated connection handoff across heterogeneous networks based on the IEEE 802.21 framework with designated user/configuration policy. Unlike conventional systems which make sub-optimal decision when managing connection handoff due to limited awareness of the relevant context for the application/service being delivered, PAHO defines proper interface to interact with the application as to determine when and to where the handoff and/or codec switching should take place in the event of network performance degradation. The results showed that using the PAHO approach on an audio/video conferencing session helps reducing the overall handover delay from 10.766 s (on non-PAHO system) down to at least 288 ms, and slowing down the degradation of MOS value throughout the entire experiment in the event of signal degradation as well as network congestion. It is also shown that load balancing among the access points (AP) could be achieved with an improved Information Server (IS). r 2007 Elsevier Ltd. All rights reserved
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