检索结果-南通市图书馆

Advances in Applied Mathematics and Mechanics 2011年第6期3卷 689-701页

作者： Malik Mamode Department of Physics Laboratoire PIMENTEquipe MASCUniversity of La Reunion97400 Saint-DenisFrance

The exact analytical expression of the period of a conservative nonlinear oscillator with a non-polynomial potential,is *** an oscillatory system corresponds to the transverse vibration of a particle attached to the center of a stretched elastic *** result is given in terms of elliptic functions and validates the approximate formulae derived from various approximation procedures as the harmonic balance method and the rational harmonic balance method usually implemented for solving such a nonlinear problem.

关键词： Nonlinear oscillator exact period elliptic integral

Hepatitis C virus infection down-regulates the expression of peroxisome proliferator-activated receptor a and carnitine palmitoyl acyl-CoA transferase 1A

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第48期11卷 7591-7596页

作者： Yang Cheng Sébastien Dharancy Mathilde Malapel Pierre Desreumaux equipe mixte INSERM 0114

AIM： To elucidate the role of the peroxisome proliferator-activated receptor α （PPARα） and its target gene camitine palmitoyl acyl-CoA transferase 2A （CPT1A） in the pathogenesis of hepatitis C virus （HCV） infection.METHODS： Liver samples were collected from the patients with chronic HCV infection and controls. HepG2 cells were transfected with vector pEF352neo carrying. Two independent clones （clone N3 and N4） stably expressing HCV core protein were analyzed. Total RNA was extracted from cells and liver tissues. PPARα and CPT1A mRNAs were quantified by real-time polymerase chain reaction （PCR） using SYBR Green Master. Total extracted proteins were separated by polyacrylamide gel electrophoresis, and electroblotted. Membranes were incubated with the anti-PPARα antibody, then with a swine anti-rabbit IgG conjugated to horseradish peroxidase for PPARα. Protein bands were revealed by an enhanced chemiluminescence reaction for PPARα. For immunohistochemical staining of PPARα, sections were incubated with the primary goat polyclonal antibody directed against PPARα at room temperature.RESULTS： Real-time PCR indicated that the PPARα level and expression level of CPT1A gene in hepatitis C patients lowered significantly as compared with the controls （1.8±2.8 vs 13±3.4, P = 0.0002; 1.1±1.5 vs 7.4±1, P = 0.004）. Western blot results showed that the level of PPARα protein in the livers of hepatitis C patients was lower than that in controls （2.3±0.3 vs 3.6±0.2, P = 0.009）. The immunohistochemical staining results in chronic hepatitis C patients indicated a decrease in PPARα staining in hepatocytes compared with those in the control livers. The in vitro studies found that in the N3 and N4 colon stably expressing HCV core protein, the PPARα mRNA levels were significantly lower than that in the controls.CONCLUSION： The impaired intrahepatic PPARα expression is associated with the pathogenic mechanism in hepatic injury during chronic HCV infection. HCV infection reduced the ex

关键词： Hepatitis C virus Infection PPARα CPT1A

Epididymis cholesterol homeostasis and sperm fertilizing ability

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2011年第1期13卷 11-17页

作者： Fabrice Saez Ouvrier and Joel R Drevet UMR GReD CNRS 6247 INSERM U931 Clermont Universite Equipe ＇Epididyme et maturation des gametes＇ Aubiere cedex 63171 France

Cholesterol, being the starting point of steroid hormone synthesis, is a long known modulator of both female and male reproductive physiology especially at the level of the gonads and the impact cholesterol has on gametogenesis. Less is known about the effects cholesterol homeostasis may have on postgonadic reproductive functions. Lately, several data have been reported showing how imbalanced cholesterol levels may particularly affect the post-testicular events of sperm maturation that lead to fully fertile male gametes. This review will focus on that aspect and essentially centers on how cholesterol is important for the physiology of the mammalian epididymis and spermatozoa.

关键词： cholesterol homeostasis epididymosomes fertility post-testicular maturation spermatozoa

Generation of Different Classes of Multipartite Entanglement Using Cavity-QED

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2018年第2期69卷 131-136页

作者： Mustapha Ziane Rachid El Guerbouz Fatima-Zahra Siyouri Morad El Baz equipe Sciences de la Matière et du Rayonnement Département de Physique Faculté des sciences Université Mohammed V Av.Ibn Battouta

Using a system of cavity quantum electrodynamics （QED） we present two schemes for multipartite entan- glement generation. In the first scheme, a three-level atom is interacting with three cavities successively. In the second one, two three-level atoms are interacted with a coherent optical cavity. These protocols allow us to generate the six c/asses of tripartite entanglement （GHZ, W, A-B-C, AB-C, C-AB, and B-AC class states） by controling the interaction time between atoms and cavities. Moreover, they allow us to generate entanglement between the cavity fields degrees of freedom （from the first scheme）, and a mixed entanglement between the cavity field degrees of freedom and the atomic degrees of freedom.

关键词： entanglement coherent states cavity QE-D GHZ states W states

On stability behaviors of 5D M-theory black objects

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第5期76卷 94-101页

作者： Adil Belhaj Abderrahim Bouhouch Departement de Physique Equipe des Sciences de la matiere et du rayonnementESMaR Faculte des SciencesUniversite Mohammed V de RabatRabatMorocco

Using N=2 supergravity formalism,we investigate certain behaviors of five-dimensional black objects from the compactification of M-theory on a Calabi-Yau *** manifold has been constructed as the intersection of two homogeneous polynomials of degrees(ω+2,1)and(2,1)in a product of two weighted projective spaces given by WP^(4)(ω,1,1,1,1)×P^(1).First,we determine the allowed electric charge regions of the BPS and non BPS black holes obtained by wrapping M2-branes on appropriate two cycles in such a proposed Calabi-Yau *** that,we calculate the entropy of these solutions which takes a maximal value corresponding to ω=1 defining the ordinary projective space P^(4).For generic values of ω,we show that the non BPS states are ***,we conduct a similar study of five-dimensional black *** the allowed magnetic charge regions of the BPS and non BPS black stringy solutions derived from M5-branes on dual divisors,we calculate the tension taking a minimal value for P^(4).By determining the recombination factor,we show that the non-BPS black string states are stable in the allowed regions in the magnetic charge space.

关键词： M-theory Calabi-Yau manifolds black holes black strings stability behaviors

Molecular analysis of γ1, γ3, and α class switch recombination junctions in APOBEC3-deficient mice using high-throughput sequencing

在线全文

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2020年第4期17卷 418-420页

作者： Hussein Issaoui Mélissa Ferrad Nour Ghazzaui Sandrine Lecardeur Jeanne Cook-Moreau François Boyer Yves Denizot UMR CNRS 7276 INSERM U1262Equipe Labellisée LIGUE 2018University of LimogesCBRSrue Pr.Descottes87025 LimogesFrance

Activation-induced deaminase(AID)is required for immunoglobulin(Ig)class switch recombination(CSR),in which the constant(C)μgene of IgM is substituted with C_(γ),C_(ε),or C_(α),thereby generating IgG,IgE,and IgA antibodies,respectively,with new effector functions but the same antigenic specificity.1 AID targets specific DNA switch(S)regions preceding C regions except for Cδ.2 Sμis usually the donor region,while Sγ,ε,αare the acceptor *** deaminates C into U on single-stranded DNA by targeting the WRCY(W=A/T,R=A/G,and Y=C/T)hot motif and,to a lesser extent,the SYC(S=G/C,Y=C/T)cold motif.3,4 AID is a member of the apolipoprotein B editing complex(APOBEC)*** APOBEC genes,a family of evolutionarily conserved cytidine deaminases,APOBEC3 is implicated in diverse cell functions including innate immunity against retroviruses.4 The DNA-editing APOBEC3 enzymes have recently attracted attention due to their involvement in cancer and potential applications in gene editing.5–7 While a single copy of each APOBEC3 gene is present in rodents,seven copies of each APOBEC3 gene are found in humans.

关键词： immunity involvement thereby

Class switch recombination junctions are not affected by the absence of the immunoglobulin heavy chain E_(μ) enhancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2019年第7期16卷 671-673页

作者： Hussein Issaoui Nour Ghazzaui Mélissa Ferrad François Boyer Yves Denizot UMR CNRS 7276 INSERM U1262Equipe Labellisée LIGUE 2018University of LimogesCBRSrue Pr.Descottes87025 LimogesFrance

After encountering antigen,B-cells undergo class switch recombination(CSR)that substitutes the constant(C)μgene with Cγ,Cε,or Cα,thereby generating IgG,IgE,and IgA antibodies with new effector functions but the same antigenic specificity.1 The DNA-editing enzyme activation-induced deaminase(AID)is required for CSR by targeting specific DNA switch(S)regions preceding the C region,except Cδ.2 Sμis the donor region,while Sγ,ε,αare the acceptor *** is controlled in cis by the immunoglobulin heavy chain(IgH)3’regulatory region(3’RR).3 The 3’RR is essential to poise AID on the S acceptor *** CSR IgH,intrachromosomal interactions(schematized in Fig.1a)are found between the 3’RR and the intronic Eμenhancer.1,4 Looping allows transcriptional binding activators to enhancers to facilitate ***,CSR is only modestly influenced by Eμdeletion.5–7 During CSR,two different DNA repair pathways take place:the classical nonhomologous end joining(c-NHEJ)and the alternative end joining(A-EJ)pathways.

关键词： joining thereby generating

Formation of a 40 A DC Current Arc During the Opening of Silver Contacts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2014年第5期16卷 471-478页

作者： M'hammed ABBAOUI André LEFORT Erwann CARVOU Damien SALLAIS James Brian Alexander MITCHELL Noureddine BEN JEMAA Clermont Université Université d'AuvergneEA 3120LAEPTBP 10448F-63000 Clermont-FerrandFrance equipe Contacts Electriques IPR(UMR CNRS 6251)Universite de Rennes 135042 Rennes CedexFrance

The erosion of silver contacts due to break arcs with length proportional to time and of variable duration has been measured by weighing the contacts following 5000 openings at a constant current equal to 40 *** experimental results show that,for arc durations shorter than 60 μs,the transfer of metal from the anode to the cathode occurs,but after passing this stage,when the two electrodes are separated by greater distances,each will display *** is the result of the diffusion of material outside the space between the two *** order to interpret these results,we have applied a classical model of the physical phenomena occurring at the root of the *** of the experimental results shows that for an arc duration of less than15 μs,no distinct cathode root is seen to exist,but beyond this,several spots appear gradually on the cathode for arc duration up to 50 μs,after which they merge into a single *** comparison between experiment results and theoretical interpretation is reasonable up to 60 μs.

关键词： arc root cathode spot anode spot erosion contacts current density

First-principles calculations to investigate structural,electronic,magnetic,optical and thermodynamic properties of RE_(2)Rh_(3)Ge(RE=Pr,Sm)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第7期42卷 1385-1393,I0007页

作者： A.Ezaier R.Masrour M.Hamedoun J.Kharbach A.Rezzouk A.Hourmatallah N.Benzakour K.Bouslykhane Laboratory of Solid Physics Faculty of Sciences Dhar El MehrazSidi Mohamed Ben Abdellah UniversityBP 1796FezMorocco equipe de Physique du Solide LaboratoiresLIPIEcole Normale SupérieureBensoudaFèsMorocco

In this paper,we analyzed the physical characteristics of the ternary alloys RE_(2)Rh_(3)Ge(RE=Pr and Sm)using the first principles calculation based on functional density theory integrated in the Wien2k *** calculated formation energies of Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge are−5.3827 and−5.2782 eV/atom,respectively,showing that these alloys may exist *** results of the band structure and density of states indicate that all of the compounds tested are magnetic metals,and their magnetism is mostly related to the contribution of Pr and Sm *** total magnetic moments of Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge are 4.07245 and 11.16161μB/f.u,*** parameters such as heat capacity at constant pressure,entropy,Debye temperature,lattice volume,compressibility coefficients,and Grüneisen parameter alloys were calculated using the Gibbs algorithm and studied in depth over a large temperature range of 0-900 *** Debye temperature increases with increasing pressure and decreases with decreasing ***,the Debye temperatures calculated at p=0 GPa and T=300 K are equal to be 342 and 322 K for Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge,*** optical characteristics such as the real and imaginary portions of the dielectric function,the absorption coefficient,the energy-loss function,and the refractive index were investigated and discussed in more depth.

关键词： Magnetic metals Functional density theory Density of states Magnetic moment Optical and thermodynamic properties Rare earths

Potential generated by a massive inhomogeneous straight segment

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2011年第3期11卷 345-352页

作者： Nour-Eddine Najid El Haj Elourabi Mohamed Zegoumou equipe Mécanique Statistique et Astronomie-Laboratoire de Physique Théorique et Appliquée Université Hassan Ⅱ Ain Chock-Faculté des Sciences Ain Chock BP 5366 Maarif Casablanca Morocco

The discoveries of binary asteroids have opened an important new field of research concerning the calculation of potential generated by irregular *** of them have an elongated shape.A simple model to describe the motion of a test particle in that kind of potential requires consideration of a finite homogeneous straight *** construct this model by adding an inhomogeneous distribution of mass. To be consistent with the geometrical shape of the asteroid,we explore a parabolic profile of the *** establish the closed analytical form of the potential generated by this inhomogeneous massive *** study of the dynamical behavior is fulfilled by the use of Lagrangian formulation,which allows us to calculate some two and three dimensional orbits.

关键词： asteroids—potential—inhomogeneous distribution