3,952 research outputs found
Many-body dynamics of a Bose system with attractive interactions on a ring
We investigate the many-body dynamics of an effectively attractive
one-dimensional Bose system confined in a toroidal trap. The mean-field theory
predicts that a bright-soliton state will be formed when increasing the
interparticle interaction over a critical point. The study of quantum many-body
dynamics in this paper reveals that there is a modulation instability in a
finite Bose system correspondingly. We show that Shannon entropy becomes
irregular near and above the critical point due to quantum correlations. We
also study the dynamical behavior of the instability by exploring the momentum
distribution and the fringe visibility, which can be verified experimentally by
releasing the trapComment: 6 pages,5 figure
Reversible Transition Between Thermodynamically Stable Phases with Low Density of Oxygen Vacancies on SrTiO(110) Surface
The surface reconstruction of SrTiO(110) is studied with scanning
tunneling microscopy and density functional theory (DFT) calculations. The
reversible phase transition between (41) and (51) is controlled
by adjusting the surface metal concentration [Sr] or [Ti]. Resolving the atomic
structures of the surface, DFT calculations verify that the phase stability
changes upon the chemical potential of Sr or Ti. Particularly, the density of
oxygen vacancies is low on the thermodynamically stabilized SrTiO(110)
surface.Comment: Accepted by Physical Review Letter
Analysis on the evolution process of BFW-like model with explosive percolation of multiple giant components
Recently, the modified BFW model on random graph [Phys. Rev. Lett., 106,
115701 (2011)], which shows a strongly discontinuous percolation transition
with multiple giant components, has attracted much attention from physicists,
statisticians and materials scientists. In this paper, by establishing the
theoretical expression of evolution equations on the modified BFW model, the
steady-state and evolution process are analyzed and a close correspondence is
built between the values of parameter \alpha and the number of giant components
in steady-states, which fits very well with the numerical simulations. In fact,
with the value of \alpha decreasing to 0.25, the error between theoretical and
numerical results is smaller than 4% and trends to 0 rapidly. Furthermore, the
sizes of giant components for different evolution strategies can also be
obtained by solving some constraints derived from the evolution equations. The
analysis of the steady-state and evolution process is of great help to explain
why the percolation of modified BFW model is explosive and how explosive it is.Comment: 12 pages, 5 figure
Telmisartan prevents weight gain and obesity through activation of peroxisome proliferator-activated receptor-delta-dependent pathways
Abstract—Telmisartan shows antihypertensive and several pleiotropic effects that interact with metabolic pathways. In the present study we tested the hypothesis that telmisartan prevents adipogenesis in vitro and weight gain in vivo through activation of peroxisome proliferator-activated receptor (PPAR)-–dependent pathways in several tissues. In vitro, telmisartan significantly upregulated PPAR- expression in 3T3-L1 preadipocytes in a time- and dose-dependent manner. Other than enhancing PPAR- expression by 68.217.3 % and PPAR- activity by 102.09.0%, telmisartan also upregulated PPAR- expression, whereas neither candesartan nor losartan affected PPAR- expression. In vivo, long-term administration of telmisartan significantly reduced visceral fat and prevented high-fat diet-induced obesity in wild-type mice and hypertensive rats but not in PPAR- knockout mice. Administration of telmisartan did not influence food intake in mice. Telmisartan influenced several lipolytic and energy uncoupling related proteins (UCPs) and enhanced phosphorylated protein kinase A and hormone sensitive lipase but reduced perilipin expression and finally inhibited adipogenesis in 3T3-L1 preadipocytes. Telmisartan-associated reduction of adipogenesis in preadipocytes was significantly blocked after PPAR- gene knockout. Chronic telmisartan treatment upregulated the expressions of protein kinase A, hormone-sensitive lipase, and uncoupling protein 1 but reduced perilipin expression in adipose tissue and increased uncoupling protein 2 and 3 expression in skeletal muscle in wild-type mice but not in PPAR- knockout mice. We conclude that telmisartan prevents adipogenesis and weight gain through activation of PPAR-–dependent lipolyti
Characteristics of tumor infiltrating lymphocyte and circulating lymphocyte repertoires in pancreatic cancer by the sequencing of T cell receptors
Pancreatic cancer has a poor prognosis and few effective treatments. The failure of treatment is partially due to the high heterogeneity of cancer cells within the tumor. T cells target and kill cancer cells by the specific recognition of cancer-associated antigens. In this study, T cells from primary tumor and blood of sixteen patients with pancreatic cancer were characterized by deep sequencing. T cells from blood of another eight healthy volunteers were also studied as controls. By analyzing the complementary determining region 3 (CDR3) gene sequence, we found no significant differences in the T cell receptor (TCR) repertoires between patients and healthy controls. Types and length of CDR3 were similar among groups. However, two clusters of patients were identified according to the degree of CDR3 overlap within tumor sample group. In addition, clonotypes with low frequencies were found in significantly higher numbers in primary pancreatic tumors compared to blood samples from patients and healthy controls. This study is the first to characterize the TCR repertoires of pancreatic cancers in both primary tumors and matched blood samples. The results imply that specific types of pancreatic cancer share potentially important immunological characteristics
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