1,525 research outputs found
Length and temperature dependent crossover of charge transport across molecular junctions
We study the electronic transport in a molecular junction in which each site
is coupled to a local phonon bath using the non-equilibrium Green's function
method. We observe the length period of the oscillatory conductance in
odd-numbered chains depends strongly on the applied bias, and the oscillatory
behavior is smeared out for the bias voltage near the phonon energy. In
addition, a crossover from tunneling to thermally activated hopping transport
as the length of the molecule increases is found for the phonon-free case. In
the presence of electron-phonon interaction, hopping transport is dominant and
a transition from the thermally suppressed to assisted conduction is observed.Comment: 9 pages, 10 figure
Quantum Impurity in Luttinger Liquid: Universal Conductance with Entanglement Renormalization
We study numerically the universal conductance of Luttinger liquids wire with
a single impurity via the Muti-scale Entanglement Renormalization Ansatz
(MERA). The scale invariant MERA provides an efficient way to extract scaling
operators and scaling dimensions for both the bulk and the boundary conformal
field theories. By utilizing the key relationship between the conductance
tensor and ground-state correlation function, the universal conductance can be
evaluated within the framework of the boundary MERA. We construct the boundary
MERA to compute the correlation functions and scaling dimensions for the
Kane-Fisher fixed points by modeling the single impurity as a junction (weak
link) of two interacting wires. We show that the universal behavior of the
junction can be easily identified within the MERA and argue that the boundary
MERA framework has tremendous potential to classify the fixed points in general
multi-wire junctions.Comment: 14 pages, 18 figure
POSTURAL STABILITY PERFORMANCE BETWEEN SEDENTARY AND ACTIVE SUBJECTS WITH THE BIODEX STABILITY SYSTEM
INTRODUCTION: Postural stability (PS) has been defined as the ability to maintain an upright posture within the base of support (Lee and Lin, 2007) and is considered to be an important indicator of musculoskeletal health and physical performance. This study examined the PS performance between sedentary and active subjects using the Biodex Balance System (BBS) with well intraclass correlation coefficient (Hinman, 2000)
Tunable Atomically Wide Electrostatic Barriers Embedded in a Graphene WSe2 Heterostructure
Inducing and controlling electrostatic barriers in two-dimensional (2D)
quantum materials has shown extraordinary promise to enable control of charge
carriers, and is key for the realization of nanoscale electronic and
optoelectronic devices1-10. Because of their atomically thin nature, the 2D
materials have a congenital advantage to construct the thinnest possible p-n
junctions1,3,7,9,10. To realize the ultimate functional unit for future
nanoscale devices, creating atomically wide electrostatic barriers embedded in
2D materials is desired and remains an extremely challenge. Here we report the
creation and manipulation of atomically wide electrostatic barriers embedded in
graphene WSe2 heterostructures. By using a STM tip, we demonstrate the ability
to generate a one-dimensional (1D) atomically wide boundary between 1T-WSe2
domains and continuously tune positions of the boundary because of
ferroelasticity of the 1T-WSe2. Our experiment indicates that the 1D boundary
introduces atomically wide electrostatic barriers in graphene above it. Then
the 1D electrostatic barrier changes a single graphene WSe2 heterostructure
quantum dot from a relativistic artificial atom to a relativistic artificial
molecule
Two variants on T2DM susceptible gene HHEX are associated with CRC risk in a Chinese population
Increasing amounts of evidence has demonstrated that T2DM (Type 2 Diabetes Mellitus) patients have increased susceptibility to CRC (colorectal cancer). As HHEX is a recognized susceptibility gene in T2DM, this work was focused on two SNPs in HHEX, rs1111875 and rs7923837, to study their association with CRC. T2DM patients without CRC (T2DM-only, n=300), T2DM with CRC (T2DM/CRC, n=135), cancer-free controls (Control, n=570), and CRC without T2DM (CRC-only, n=642) cases were enrolled. DNA samples were extracted from the peripheral blood leukocytes of the patients and sequenced by direct sequencing. The χ(2) test was used to compare categorical data. We found that in T2DM patients, rs1111875 but not the rs7923837 in HHEX gene was associated with the occurrence of CRC (p= 0.006). for rs1111875, TC/CC patients had an increased risk of CRC (p=0.019, OR=1.592, 95%CI=1.046-2.423). Moreover, our results also indicated that the two variants of HEEX gene could be risk factors for CRC in general population, independent on T2DM (p< 0.001 for rs1111875, p=0.001 for rs7923837). For rs1111875, increased risk of CRC was observed in TC or TC/CC than CC individuals (p<0.001, OR= 1.780, 95%CI= 1.385-2.287; p<0.001, OR= 1.695, 95%CI= 1.335-2.152). For rs7923837, increased CRC risk was observed in AG, GG, and AG/GG than AA individuals (p< 0.001, OR= 1.520, 95%CI= 1.200-1.924; p=0.036, OR= 1.739, 95%CI= 0.989-3.058; p< 0.001, OR= 1.540, 95%CI= 1.225-1.936). This finding highlights the potentially functional alteration with HHEX rs1111875 and rs7923837 polymorphisms may increase CRC susceptibility. Risk effects and the functional impact of these polymorphisms need further validation
A preliminary study on the immune responses of HPV16-E7 by combined intranasal immunization with lymphotoxin
Objectives: Human papillomavirus (HPV) ranks the first cause of cervical cancer. Cervical cancer has high prevalence ratesin women around the world. The HPV-E7 oncoprotein is expressed in cervical cancer and is a target of developing immunotherapiesagainst HPV-associated tumors. However, the antigenicity of this protein is low. Due to this reason, potentadjuvants are required to enhance its therapeutic efficacy. This preliminary study aims to evaluate whether lymphotoxin(LT) could act as an effective immune adjuvant for HPV infection in mice models.Material and methods: Intranasal immunization was used to explore the effect of HPV-E7 and/or LT immune response.After the third intranasal immunization, the titer for the HPV-E7 antibody was detected in serum and vaginal washing fluid.Also, we assessed the expression of chemokine ligand 13 (CXCL13) and Peripheral Node Addressin (PNAd) in the lymphnodes after intranasal immunization with immunohistochemical analysis.Results: compared to HPV-E7 immunization, intranasal immunization with HPV-E7 plus LT significantly increased HPV-E7-specificserum IgG and vaginal IgA titers. Furthermore, the combined use of HPV-E7 and LT strongly induced E7-specific CTLresponses.Conclusions: LT can be effective for intranasal immunized HPV-E7 to improve E7-specific immune responses to HPV infection.It is new approach to eradicate chronic HPV infection capable of inducing an effective anti-infection method
Age- and Gender-Specific Prevalence of Risk Factors in Patients with First-Ever Ischemic Stroke in China
Background. Evidences are accumulating that age and gender have great impact on the distribution of stroke risk factors. Such data are lacking in Chinese population. Methods. 1027 patients with first-ever ischemic stroke (IS) were recruited and divided into young adult (<50 years), middle-aged (50∼80 years), and very old (>80 years) groups according to stroke onset ages. Vascular risk factors were collected and compared among groups. Results. Female patients were globally older than male patients at stroke onset and having higher prevalence of diabetes mellitus (DM), heart diseases, and atrial fibrillation (AF). However, females were less likely to drink heavily or smoke than males. Young patients had a much higher proportion of smoking and drinking than middle-aged and very old patients and the highest family history of hypertension, while very old patients had the highest prevalence of heart diseases and AF but lowest proportion of positive family history of vascular diseases. Hypertension and DM were equally frequent among three groups. Conclusion. Our study showed that vascular risk factors had a specific age and gender distribution pattern in Chinese IS patients. Secondary prevention strategy should emphasize on the control of different risk factors based on patient's age and gender
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