165 research outputs found

    Approximate solution of the Duffin-Kemmer-Petiau equation for a vector Yukawa potential with arbitrary total angular momenta

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    The usual approximation scheme is used to study the solution of the Duffin-Kemmer-Petiau (DKP) equation for a vector Yukawa potential in the framework of the parametric Nikiforov-Uvarov (NU) method. The approximate energy eigenvalue equation and the corresponding wave function spinor components are calculated for arbitrary total angular momentum in closed form. Further, the approximate energy equation and wave function spinor components are also given for case. A set of parameter values is used to obtain the numerical values for the energy states with various values of quantum levelsComment: 17 pages; Communications in Theoretical Physics (2012). arXiv admin note: substantial text overlap with arXiv:1205.0938, and with arXiv:quant-ph/0410159 by other author

    A semi-relativistic treatment of spinless particles subject to the nuclear Woods-Saxon potential

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    By applying an appropriate Pekeris approximation to deal with the centrifugal term, we present an approximate systematic solution of the two-body spinless Salpeter (SS) equation with the Woods-Saxon interaction potential for arbitrary -state. The analytical semi-relativistic bound-state energy eigenvalues and the corresponding wave functions are calculated. Two special cases from our solution are studied: the approximated Schr\"odinger-Woods-Saxon problem for arbitrary l -state and the exact s-wave (l=0).Comment: 14 pages; 4 figures, to appear in Chinese Physics C (2012

    Approximate k-state solutions to the Dirac-Yukawa problem based on the spin and pseudospin symmetry

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    Using an approximation scheme to deal with the centrifugal (pseudo-centrifugal) term, we solve the Dirac equation with the screened Coulomb (Yukawa) potential for any arbitrary spin-orbit quantum number {\kappa}. Based on the spin and pseudospin symmetry, analytic bound state energy spectrum formulas and their corresponding upper- and lower-spinor components of two Dirac particles are obtained using a shortcut of the Nikiforov-Uvarov method. We find a wide range of permissible values for the spin symmetry constant C_{s} from the valence energy spectrum of particle and also for pseudospin symmetry constant C_{ps} from the hole energy spectrum of antiparticle. Further, we show that the present potential interaction becomes less (more) attractive for a long (short) range screening parameter {\alpha}. To remove the degeneracies in energy levels we consider the spin and pseudospin solution of Dirac equation for Yukawa potential plus a centrifugal-like term. A few special cases such as the exact spin (pseudospin) symmetry Dirac-Yukawa, the Yukawa plus centrifugal-like potentials, the limit when {\alpha} becomes zero (Coulomb potential field) and the non-relativistic limit of our solution are studied. The nonrelativistic solutions are compared with those obtained by other methods.Comment: 21 pages, 6 figure

    Ginkgo biloba for the treatment of vitilgo vulgaris: an open label pilot clinical trial

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    <p>Abstract</p> <p>Background</p> <p>Vitiligo is a common hypopigmentation disorder with significant psychological impact if occurring before adulthood. A pilot clinical trial to determine the feasibility of an RCT was conducted and is reported here.</p> <p>Methods</p> <p>12 participants 12 to 35 years old were recruited to a prospective open-label pilot trial and treated with 60 mg of standardized <it>G. biloba </it>two times per day for 12 weeks. The criteria for feasibility included successful recruitment, 75% or greater retention, effectiveness and lack of serious adverse reactions. Effectiveness was assessed using the Vitiligo Area Scoring Index (VASI) and the Vitiligo European Task Force (VETF), which are validated outcome measures evaluating the area and intensity of depigmentation of vitiligo lesions. Other outcomes included photographs and adverse reactions. Safety was assessed by serum coagulation factors (platelets, PTT, INR) at baseline and week 12.</p> <p>Results</p> <p>After 2 months of recruitment, the eligible upper age limit was raised from 18 to 35 years of age in order to facilitate recruitment of the required sample size. Eleven participants completed the trial with 85% or greater adherence to the protocol. The total VASI score improved by 0.5 (P = 0.021) from 5.0 to 4.5, range of scale 0 (no depigmentation) to 100 (completely depigmented). The progression of vitiligo stopped in all participants; the total VASI indicated an average repigmentation of vitiligo lesions of 15%. VETF total vitiligo lesion area decreased 0.4% (P = 0.102) from 5.9 to 5.6 from baseline to week 12. VETF staging score improved by 0.7 (P = 0.101) from 6.6 to 5.8, and the VETF spreading score improved by 3.9 (P < 0.001)) from 2.7 to -1.2. There were no statistically significant changes in platelet count, PTT, or INR.</p> <p>Conclusions</p> <p>The criteria for feasibility were met after increasing the maximum age limit of the successful recruitment criterion; participant retention, safety and effectiveness criteria were also met. Ingestion of 60 mg of <it>Ginkgo biloba </it>BID was associated with a significant improvement in total VASI vitiligo measures and VETF spread, and a trend towards improvement on VETF measures of vitiligo lesion area and staging. Larger, randomized double-blind clinical studies are warranted and appear feasible.</p> <p>Trial Registration</p> <p>Clinical trials.gov registration number <a href="http://www.clinicaltrials.gov/ct2/show/NCT00907062">NCT00907062</a></p

    Asiatic Acid Inhibits Liver Fibrosis by Blocking TGF-beta/Smad Signaling In Vivo and In Vitro

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    Liver fibrosis is a major cause of liver failure, but treatment remains ineffective. In the present study, we investigated the mechanisms and anti-hepatofibrotic activities of asiatic acid (AA) in a rat model of liver fibrosis induced by carbon tetrachloride (CCl4) and in vitro in TGF-beta1-stimulated rat hepatic stellate cell line (HSC-T6). Treatment with AA significantly attenuated CCl4-induced liver fibrosis and functional impairment in a dosage-dependent manner, including blockade of the activation of HSC as determined by inhibiting de novo alpha smooth muscle actin (a-SMA) and collagen matrix expression, and an increase in ALT and AST (all p<0.01). The hepatoprotective effects of AA on fibrosis were associated with upregulation of hepatic Smad7, an inhibitor of TGF-beta signaling, thereby blocking upregulation of TGF-beta1 and CTGF and the activation of TGF-beta/Smad signaling. The anti-fibrosis activity and mechanisms of AA were further detected in vitro in HSC-T6. Addition of AA significantly induced Smad7 expression by HSC-T6 cells, thereby inhibiting TGF-beta1-induced Smad2/3 activation, myofibroblast transformation, and collagen matrix expression in a dosage-dependent manner. In contrast, knockdown of Smad7 in HSC-T6 cells prevented AA-induced inhibition of HSC-T6 cell activation and fibrosis in response to TGF-beta1, revealing an essential role for Smad7 in AA-induced anti-fibrotic activities during liver fibrosis in vivo and in vitro. In conclusion, AA may be a novel therapeutic agent for liver fibrosis. Induction of Smad7-dependent inhibition of TGF-beta/Smad-mediated fibrogenesis may be a central mechanism by which AA protects liver from injury

    Cross-Frequency Integration for Consonant and Vowel Identification in Bimodal Hearing

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    Purpose: Improved speech recognition in binaurally combined acoustic–electric stimulation (otherwise known as bimodal hearing) could arise when listeners integrate speech cues from the acoustic and electric hearing. The aims of this study were (a) to identify speech cues extracted in electric hearing and residual acoustic hearing in the low-frequency region and (b) to investigate cochlear implant (CI) users' ability to integrate speech cues across frequencies. Method: Normal-hearing (NH) and CI subjects participated in consonant and vowel identification tasks. Each subject was tested in 3 listening conditions: CI alone (vocoder speech for NH), hearing aid (HA) alone (low-pass filtered speech for NH), and both. Integration ability for each subject was evaluated using a model of optimal integration—the PreLabeling integration model (Braida, 1991). Results: Only a few CI listeners demonstrated bimodal benefit for phoneme identification in quiet. Speech cues extracted from the CI and the HA were highly redundant for consonants but were complementary for vowels. CI listeners also exhibited reduced integration ability for both consonant and vowel identification compared with their NH counterparts. Conclusion: These findings suggest that reduced bimodal benefits in CI listeners are due to insufficient complementary speech cues across ears, a decrease in integration ability, or both.National Organization for Hearing ResearchNational Institute on Deafness and Other Communication Disorders (U.S.) (Grant R03 DC009684-01)National Institute on Deafness and Other Communication Disorders (U.S.) (Grant R01 DC007152-02

    Exact solution of Schr\"odinger equation with q-deformed quantum potentials using Nikiforov-Uvarov method

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    In this paper, we present the exact solution of one dimensional Schr\"odinger equation for Wood-Saxon plus Rosen-Morse plus symmetrical double well potential via Nikiforov-Uvarov mathematical method. The eigenvalues and eigenfunctions of this potential are obtained. The energy equations and the corresponding wave function for special cases of this potential are briefly discussed. The PT-symmetry and Hermiticity for this potential are also considered.Comment: 8 pages, no figur

    Spermidine Promotes Human Hair Growth and Is a Novel Modulator of Human Epithelial Stem Cell Functions

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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