759 research outputs found

    TGF-beta/Smad signaling through DOCK4 facilitates lung adenocarcinoma metastasis

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    The mechanisms by which TGF-beta promotes lung adenocarcinoma (ADC) metastasis are largely unknown. Here, we report that in lung ADC cells, TGF-beta potently induces expression of DOCK4, but not other DOCK family members, via the Smad pathway and that DOCK4 induction mediates TGF-beta's prometastatic effects by enhancing tumor cell extravasation. TGF-beta-induced DOCK4 stimulates lung ADC cell protrusion, motility, and invasion without affecting epithelial-to-mesenchymal transition. These processes, which are fundamental to tumor cell extravasation, are driven by DOCK4-mediated Rac1 activation, unveiling a novel link between TGF-beta and Rac1. Thus, our findings uncover the atypical Rac1 activator DOCK4 as a key component of the TGF-beta/Smad pathway that promotes lung ADC cell extravasation and metastasis

    Δ\Delta-scaling and Information Entropy in Ultra-Relativistic Nucleus-Nucleus Collisions

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    The Δ\Delta-scaling method has been applied to ultra-relativistic p+p, C+C and Pb+Pb collision data simulated using a high energy Monte Carlo package, LUCIAE 3.0. The Δ\Delta-scaling is found to be valid for some physical variables, such as charged particle multiplicity, strange particle multiplicity and number of binary nucleon-nucleon collisions from these simulated nucleus-nucleus collisions over an extended energy ranging from ElabE_{lab} = 20 to 200 A GeV. In addition we derived information entropy from the multiplicity distribution as a function of beam energy for these collisions.Comment: 4 pages, 4 figures, 1 table; to appear in the July Issue of Chin. Phys. Lett.. Web Page: http://www.iop.org/EJ/journal/CP

    Universality of low-energy scattering in (2+1) dimensions

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    We prove that, in (2+1) dimensions, the S-wave phase shift, δ0(k) \delta_0(k), k being the c.m. momentum, vanishes as either δ0cln(k/m)orδ0O(k2)\delta_0 \to {c\over \ln (k/m)} or \delta_0 \to O(k^2) as k0k\to 0. The constant cc is universal and c=π/2c=\pi/2. This result is established first in the framework of the Schr\"odinger equation for a large class of potentials, second for a massive field theory from proved analyticity and unitarity, and, finally, we look at perturbation theory in ϕ34\phi_3^4 and study its relation to our non-perturbative result. The remarkable fact here is that in n-th order the perturbative amplitude diverges like (lnk)n(\ln k)^n as k0k\to 0, while the full amplitude vanishes as (lnk)1(\ln k)^{-1}. We show how these two facts can be reconciled.Comment: 23 pages, Late

    Relativistic Generalization of the Gamow Factor for Fermion Pair Production or Annihilation

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    In the production or annihilation of a pair of fermions, the initial-state or final-state interactions often lead to significant effects on the reaction cross sections. For Coulomb-type interactions, the Gamow factor has been traditionally used to take into account these effects. However the Gamow factor needs to be modified when the magnitude of the coupling constant or the relative velocity of two particles increases. We obtain the relativistic generalization of the Gamow factor in terms of the overlap of the Feynman amplitude with the relativistic wave function of two fermions with an attractive Coulomb-type interaction. An explicit form of the corrective factor is presented for the spin-singlet S-wave state. While the corrective factor approaches the Gamow factor in the non-relativistic limit, we found that the Gamow factor significantly over-estimates the effects when the coupling constant or the velocity is large.Comment: 16 pages, 4 figures in LaTe

    Time-Dependent Spintronic Transport and Current-Induced Spin Transfer Torque in Magnetic Tunnel Junctions

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    The responses of the electrical current and the current-induced spin transfer torque (CISTT) to an ac bias in addition to a dc bias in a magnetic tunnel junction are investigated by means of the time-dependent nonquilibrium Green function technique. The time-averaged current (time-averaged CISTT) is formulated in the form of a summation of dc current (dc CISTT) multiplied by products of Bessel functions with the energy levels shifted by mω0m\hbar \omega _{0}. The tunneling current can be viewed as to happen between the photonic sidebands of the two ferromagnets. The electrons can pass through the barrier easily under high frequencies but difficultly under low frequencies. The tunnel magnetoresistance almost does not vary with an ac field. It is found that the spin transfer torque, still being proportional to the electrical current under an ac bias, can be changed by varying frequency. Low frequencies could yield a rapid decrease of the spin transfer torque, while a large ac signal leads to both decrease of the electrical current and the spin torque. If only an ac bias is present, the spin transfer torque is sharply enhanced at the particular amplitude and frequency of the ac bias. A nearly linear relation between such an amplitude and frequency is observed.Comment: 13 pages,8 figure

    Polyclonal rabbit anti-murine plasmacytoma cell globulins induce myeloma cells apoptosis and inhibit tumour growth in mice

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    Multiple myelomas (MMs) are etiologically heterogeneous and there are limited treatment options; indeed, current monoclonal antibody therapies have had limited success, so more effective antibodies are urgently needed. Polyclonal antibodies are a possible alternative because they target multiple antigens simultaneously. In this study, we produced polyclonal rabbit anti-murine plasmacytoma cell immunoglobulin (PAb) by immunizing rabbits with the murine plasmacytoma cell line MPC-11. The isolated PAb bound to plasma surface antigens in several MM cell lines, inhibited their proliferation as revealed by MTT assay, and induce apoptosis as indicated by flow cytometry, microscopic observation of apoptotic changes in morphology, and DNA fragmentation on agarose gels. The cytotoxicity of PAb on MPC-11 cell lines was both dose-dependent and time-dependent; PAb exerted a 50% inhibitory effect on MPC-11 cell viability at a concentration of 200 µg/ml in 48 h. Flow cytometry demonstrated that PAb treatment significantly increased the number of apoptotic cells (48.1%) compared with control IgG (8.3%). Apoptosis triggered by PAb was confirmed by activation of caspase-3, -8, and -9. Serial intravenous or intraperitoneal injections of PAb inhibited tumour growth and prolonged survival in mice bearing murine plasmacytoma, while TUNEL assay demonstrated that PAb induced statistically significant apoptosis (P < 0.05) compared to control treatments. We conclude that PAb is an effective agent for in vitro and in vivo induction of apoptosis in multiple myeloma and that exploratory clinical trials may be warranted

    Impact of Migration and Acculturation on Prevalence of Type 2 Diabetes and Related Eye Complications in Indians Living in a Newly Urbanised Society

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    Background: Health of migrants is a major public health challenge faced by governments and policy makers. Asian Indians are among the fastest growing migration groups across Asia and the world, but the impact of migration and acculturation on diabetes and diabetes-related eye complications among Indians living in urban Asia remains unclear. Methodologies/Principal Findings: We evaluated the influence of migration and acculturation (i.e., migration status and length of residence) on the prevalence of type-2 diabetes mellitus (T2DM) and diabetes-related eye complications (diabetic retinopathy (DR) and cataract), among first-generation (defined as participant born in India with both parents born in India, n = 781) and second-generation (participants born in Singapore with both parents born in India, n = 1,112) Indian immigrants from a population-based study of Adult Indians in Singapore. Diabetes was defined as HbA1c≥6.5%, use of diabetic medication or a physician diagnosis of diabetes. Retinal and lens photographs were graded for the presence of DR and cataract. Compared to first generation immigrants, second generation immigrants had a higher age- and gender-standardized prevalence of T2DM (34.4% versus 29.0%, p<0.001), and, in those with T2DM, higher age- and gender-standardized prevalence of DR (31.7% versus 24.8%, p<0.001), nuclear cataract (13.6% versus 11.6%, p<0.001), and posterior sub-capsular cataract (6.4% versus 4.6%, p<0.001). Among first generation migrants, longer length of residence was associated with significantly younger age of diagnosis of diabetes and greater likelihood of having T2DM and diabetes-related eye complications. Conclusion: Second generation immigrant Indians and longer length of residence are associated with higher prevalence of diabetes and diabetes-related complications (i.e., DR and cataract) among migrant Indians living in Singapore. These data highlight potential worldwide impacts of migration patterns on the risk and burden of diabetes

    铟硼磷酸盐结构中的交叠生长规律研究

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    Several indium borophosphates have been reported recently, including KIn[BP2O8(OH)](I) and NaIn[BP2O8(OH)](H). The latter two compounds were synthesized under mild hydrothermal conditions, and have the same molar ratio (M-I:In:B:P:O:H) in molecular formula but with different structure types. Compound I crystallizes in the triclinic system with space group P (1) over bar (No.2), a=0.52638(4) nm, b=0.84791(5) nm, c=0.81469(9) nm, alpha=91.1741(7)degrees, beta=93.061(7)degrees, gamma=79.823(5)degrees, V=0.3573 nm(3), Z=2; while compound II possesses a monoclinic structure with space group P2(1)/n (No.14) with a=0.5177(1) nm, b=1.6815(3) nm, c=0.7684(2) nm, beta=94.10(3)degrees, V=0.6672(2) nm(3), Z=4. Eight- membered-ring and six-membered-ring are formed by alternating borate, phosphate tetrahedra and In-coordination octahedron sharing corners via common oxygen atoms in compound I and H respectively. The polyhedra in the structure are oriented along certain direction to form alternating layered fragments. These two structure types can be considered as intergrowth structures, which consist of the same layered fragments growing in different orientations. Other structure intergrowth possibilities are also expected in similar systems

    Two loop electroweak corrections to BˉXsγ\bar B\rightarrow X_s\gamma and Bs0μ+μB_s^0\rightarrow \mu^+\mu^- in the B-LSSM

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    The rare decays BˉXsγ\bar B\rightarrow X_s\gamma and Bs0μ+μB_s^0\rightarrow \mu^+\mu^- are important to research new physics beyond standard model. In this work, we investigate two loop electroweak corrections to BˉXsγ\bar B\rightarrow X_s\gamma and Bs0μ+μB_s^0\rightarrow \mu^+\mu^- in the minimal supersymmetric extension of the SM with local BLB-L gauge symmetry (B-LSSM), under a minimal flavor violating assumption for the soft breaking terms. In this framework, new particles and new definition of squarks can affect the theoretical predictions of these two processes, with respect to the MSSM. Considering the constraints from updated experimental data, the numerical results show that the B-LSSM can fit the experimental data for the branching ratios of BˉXsγ\bar B\rightarrow X_s\gamma and Bs0μ+μB_s^0\rightarrow \mu^+\mu^-. The results of the rare decays also further constrain the parameter space of the B-LSSM.Comment: 33 pages, 9 figures, Published in EPJ
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