2,751 research outputs found
A generic theory for Majorana zero modes in 2D superconductors
It is well known that non-Abelian Majorana zero modes (MZM) harbor at vortex
cores in a topological superconductor, which can be
realized in a 2D spin-orbit coupled system with a single Fermi surface and by
proximity coupling to an -wave superconductor. Here we show that existence
of non-Abelian MZMs is unrelated to the bulk topology of a 2D superconductor,
and propose that such exotic modes can be resulted in much broader range of
superconductors, being topological or trivial. For a generic 2D system with
multiple Fermi surfaces and gapped out by superconducting pairings, we show
that at least a single MZM survives if there are only odd number of Fermi
surfaces of which the corresponding superconducting orders have vortices, and
such MZM is protected by an emergent Chern-Simons invariant, irrespective of
the bulk topology of the superconductor. This result may enrich new
experimental schemes for realizing non-Aelian MZMs. In particular, we propose a
minimal scheme to realize the MZMs in a 2D superconducting Dirac semimetal with
trivial bulk topology, which can be well achieved based on the recent cold atom
experiments.Comment: 5 pages, 3 figures, plus Supplementary Materia
Undetectable quantum transfer through a continuum
We demonstrate that a quantum particle, initially prepared in a quantum well,
can propagate through a reservoir with a continuous spectrum and reappear in a
distant well without being registered in the reservoir. It is shown that such a
passage through the reservoir takes place even if the latter is {\em
continuously} monitored. We discuss a possible experimental realization of such
a teleportation phenomenon in mesoscopic systems.Comment: 8 pages, 6 figures, revised version, Phys. Lett. A, in pres
Supplementation with probiotics modifies gut flora and attenuates liver fat accumulation in rat nonalcoholic fatty liver disease model
This study aimed to evaluate the relationship between gut probiotic flora and nonalcoholic fatty liver disease in a diet-induced rat model, and to compare the effects of two different probiotic strains on nonalcoholic fatty liver disease. Forty male Sprague-Dawley rats were randomized into 4 groups for 12 weeks: control (standard rat chow), model (fat-rich diet), Lactobacillus (fat-rich diet plus Lactobacillus acidophilus), and Bifidobacterium (fat-rich diet plus Bifidobacterium longum) groups. Probiotics were provided to rats in drinking water (1010/ml). Gut bifidobacteria and lactobacilli were obviously lower at weeks 8 and 10, respectively, in the model group compared with the control group. Supplementation with Bifidobacterium significantly attenuated hepatic fat accumulation (0.10 ± 0.03 g/g liver tissue) compared with the model group (0.16 ± 0.03 g/g liver tissue). However, there was no improvement in intestinal permeability in either the Lactobacillus or the Bifidobacterium group compared with the model group. In all 40 rats, the hepatic total lipid content was negatively correlated with gut Lactobacillus (r = −0.623, p = 0.004) and Bifidobacterium (r = −0.591, p = 0.008). Oral supplementation with probiotics attenuates hepatic fat accumulation. Further, Bifidobacterium longum is superior in terms of attenuating liver fat accumulation than is Lactobacillus acidophilus
Quantum Transport from the Perspective of Quantum Open Systems
By viewing the non-equilibrium transport setup as a quantum open system, we
propose a reduced-density-matrix based quantum transport formalism. At the
level of self-consistent Born approximation, it can precisely account for the
correlation between tunneling and the system internal many-body interaction,
leading to certain novel behavior such as the non-equilibrium Kondo effect. It
also opens a new way to construct time-dependent density functional theory for
transport through large-scale complex systems.Comment: 4 pages, 2 figures; the TDDFT scheme is explained in more detail in
this new versio
Effects of temperature and wavelength choice on in-situ dissolution test of Cimetidine tablets
AbstractThe effects of temperature and wavelength choice on in-situ dissolution test instrument of Cimetidine were studied. Absorbance (A)<1.0 is required when using a fiber-optic dissolution test system. The detection wavelength of λmax (218nm) was replaced by 244nm to carry out this test. The absorbance of Cimetidine solution at different temperature showed an obvious change. Calibration of Cimetidine solution should be tested at the same temperature (37°C) with the test solution. A suitable wavelength with smaller tangent slope could be chosen for in-situ dissolution test of Cimetidine tablets
Egg cell-specific promoter-controlled CRISPR/Cas9 efficiently generates homozygous mutants for multiple target genes in Arabidopsis in a single generation
[(4-Methylbenzyl)bis(pyridin-2-ylmethyl)amine-κ3 N,N′,N′′]bis(thiocyanato-κS)copper(II) dichloromethane hemisolvate
The title compound, [Cu(NCS)2(C20H21N3)]·0.5CH2Cl2, crystallized with two independent complex molecules (A and B) in the asymmetric unit, accompanied by one dichloromethane solvent molecule. Each CuII atom has a square-pyramidal geometry, being coordinated by five N atoms, three from the (4-methylbenzyl)bis(pyridin-2-ylmethyl)amine ligand and two from the thiocyanate ligands. In the crystal, the B molecules are linked via C—H⋯S interactions, forming chains propagating along [100]
Adenovirus-mediated delivery of CALR and MAGE-A3 inhibits invasion and angiogenesis of glioblastoma cell line U87
<p>Abstract</p> <p>Background</p> <p>The management of patients with glioblastoma multiforme is difficult. Poor results have led to a search for novel therapeutic approaches. Gene therapy that could be both anti-invasive and antiangiogenic would be ideal. In this study, we constructed the recombinant adenoviral vector Ad-CALR/MAGE-A3 and evaluated its antitumor effects on glioblastoma in vitro and in vivo.</p> <p>Methods</p> <p>In this study, CALR and MAGE-A3 genes were delivered to the glioblastoma cell line U87, using adenovirus (Ad-CALR/MAGE-A3). U87 glioblastoma cells were transfected with Ad-green fluorescent protein to identify the multiplicity of infection. The expressions of CALR and MAGE-A3 were detected by PCR and Western blot. Cell proliferation was measured by MTT assay. Cell apoptosis was assessed by Annexin-V FITC/PI double staining flow cytometry. The invasive potential of U87 cells was determined by Matrigel invasion assay. Tube formation assay was used to detect the effects on angiogenesis of human umbilical vein endothelial cells. Protein expressions of PI3K/AKT, Erk1/2 and MMP-2/-9 in transfected cells were detected by Western blot. In vivo, the effects of Ad-CALR/MAGE-A3 on tumor growth and angiogenesis of U87 glioblastoma xenografts in nude mice were investigated.</p> <p>Results</p> <p>The expressions of CALR and MAGE-A3 in U87 cells resulted in the suppression of cell proliferation and invasion properties, and induced cell apoptosis. The Erk MAPK, PI3K/AKT pathways and expressions of MMP-2/-9 were inhibited in Ad-CALR/MAGE-A3-transfected cells. Outcomes of the tube formation assay confirmed the antiangiogenic effect of CALR. Moreover, in the in vivo model of glioblastoma, intratumoral injection of Ad-CALR/MAGE-A3 suppressed tumor growth and angiogenesis.</p> <p>Conclusion</p> <p>Although Ad-CALR/MAGE-A3 and Ad-CALR demonstrated antiangiogenic effects on U87 cells, the repression of invasion was significant only in Ad-CALR/MAGE-A3-treated cells. To our knowledge, this is the first description of a role for combined CALR and MAGE-A3 in the anti-invasion and antiangiogenesis of U87.</p
Quantum master equation approach to quantum transport through mesoscopic systems
For quantum transport through mesoscopic system, a quantum master equation
approach is developed in terms of compact expressions for the transport current
and the reduced density matrix of the system. The present work is an extension
of Gurvitz's approach for quantum transport and quantum measurement, namely, to
finite temperature and arbitrary bias voltage. Our derivation starts from a
second-order cummulant expansion of the tunneling Hamiltonian, then follows
conditional average over the electrode reservoir states. As a consequence, in
the usual weak tunneling regime, the established formalism is applicable for a
wide range of transport problems. The validity of the formalism and its
convenience in application are well illustrated by a number of examples.Comment: 8 pages, 1 figure; with considerable extension of the previous
version submitted in September 2004; to appear in Phys. Rev.
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