668 research outputs found
Study of Balance Equations for Hot-Electron Transport in an Arbitrary Energy Band (III)
By choosing an electron gas resting instead of drifting in the laboratory
coordinate system as the initial state, the first order perturbation
calculation of the previous paper (Phys. Stat. Sol. (b) 198, 785(1996)) is
revised and extended to include the high order field corrections in the
expression for the frictional forces and the energy transfer rates. The final
expressions are formally the same as those in first order in the electric
field, but the distribution functions of electrons appearing in them are
defined by different expressions. The problems relative to the distribution
function are discussed in detail and a new closed expression for the
distribution function is obtained. The nonlinear impurity-limited resistance of
a strong degenerate electron gas is computed numerically. The result calculated
by using the new expression for the distribution function is quite different
from that using the displaced Fermi function when the electric field is
sufficiently high.Comment: 15 pages with 3 PS figures, RevTeX, to be published in Physica Status
Solidi (b
Research Progress in the Mechanism of Effect of PRP in Bone Deficiency Healing
Platelet-rich plasma (PRP) therapy is a recently developed technique that uses a concentrated portion of autologous blood to try to improve and accelerate the healing of various tissues. There is a considerable interest in using these PRP products for the treatment used in bone deficiency healing. Because PRP products are safe and easy to prepare and administer, there has been increased attention toward using PRP in numerous clinical settings. The benefits of PRP therapy appear to be promising, and many investigators are exploring the ways in which this therapy can be used in the clinical setting. At present, the molecular mechanisms of bone defect repair studies have focused on three aspects of the inflammatory cytokines, growth factors and angiogenic factors. The role of PRP works mainly through these three aspects of bone repair. The purpose of this paper is to review the current evidence on the mechanism of the effect of PRP in bone deficiency healing
Mapping the distribution of Anthrax in Mainland China, 2005-2013
Anthrax in China was characterized by significant seasonality and spatial clustering. The spatial distribution of human anthrax was largely driven by livestock husbandry, human density, land cover, elevation, topsoil features and climate. Enhanced surveillance and intervention for livestock and human anthrax in the high-risk regions, particularly on the Qinghai-Tibetan Plateau, is the key to the prevention of human infections
A multiphase-field model for simulating the hydrogen-induced multi-spot corrosion on the surface of polycrystalline metals: Application to uranium metal
Hydrogen-induced multi-spot corrosion on the surface of polycrystalline rare
metals is a complex process, which involves the interactions between phases
(metal, hydride and oxide), grain orientations, grain boundaries, and corrosion
spots. To accurately simulate this process and comprehend the underlying
physics, a theoretical method is required that includes the following
mechanisms: i) hydrogen diffusion, ii) phase transformation, iii) elastic
interactions between phases, especially, the interactions between the oxide
film and the hydride, iv) elastic interactions between grains, and v)
interactions between hydrogen solutes and grain boundaries. In this study, we
report a multiphase-field model that incorporates all these requirements, and
conduct a comprehensive study of hydrogen-induced spot corrosion on the uranium
metal surface, including the investigation of the oxide film, multi-spot
corrosion, grain orientation, and grain boundary in the monocrystal, bicrystal,
and polycrystal systems. The results indicate that the oxide film can inhibit
the growth of hydrides and plays a crucial role in determining the correct
morphology of the hydride at the triple junction of phases. The elastic
interaction between multiple corrosion spots causes the merging of corrosion
spots and promotes the growth of hydrides. The introduction of grain
orientations and grain boundaries results in a variety of intriguing
intracrystalline and intergranular hydride morphologies. The model presented
here is generally applicable to the hydrogen-induced multi-spot corrosion on
any rare metal surface.Comment: 22 pages (text), 16 figures (text), 2 table (text), 8 pages (SI), 12
figures (SI
The Role of COL5A2 in Patients With Muscle-Invasive Bladder Cancer: A Bioinformatics Analysis of Public Datasets Involving 787 Subjects and 29 Cell Lines
Bladder cancer (BC) is one of the most common malignancies. Two previous studies identified collagen type V alpha 2 (COL5A2) as a potential biomarker in BC, both are simple reanalysis of a single transcriptomic dataset without subgroup analysis for muscle-invasive BC (MIBC). We focused in MIBC patients and explored the role of COL5A2 from an integration perspective, using refined methodology covering individual participant data meta-analysis and bioinformatics analysis. Eight transcriptomic datasets of 787 MIBC patients (including one dataset containing genomic mutation information) and two drug sensitivity datasets of 29 cell lines in which more than 250 compounds were analyzed. We found subjects with increased COL5A2 gene expression exhibited poorer prognosis, and the power analysis confirmed adequate sample size. FGFR3 was the only gene differential mutated between the COL5A2 high and low expression groups. Differential expression and co-expression network analysis suggested potential association between COL5A2 expression and essential pathways involved in cancer invasion and dissemination, including cell adhesion, extracellular matrix organization, and epithelial-mesenchymal transition. Coordinately, analysis of drug screening datasets and gene-drug interaction also revealed COL5A2 expression linked to cell morphogenesis, angiogenesis, blood vessel development, and urogenital development. The utility and feasibility of COL5A2 for clinically applicable prognosis prediction and risk classification and the exact underlying molecular mechanism should be further investigated in subsequent studies
Relationship between Serum Levels of OPG and TGF- β
The objective of this study was to investigate the relationship between serum levels of OPG, TGF-β1, and TGF-β2 and BMD decrease rate (BDR) in native Chinese women. This cross-sectional study was performed on 465 healthy native Chinese women aged 35–80 years. Serum levels of OPG, TGF-β1, and TGF-β2 were determined. BDR was measured by DXA at the posteroanterior spine, hip, and distal forearm. At all skeletal sites tested, there was a negative correlation between BDR and serum levels of both OPG (r=−0.122 to –0.230, all P = 0.007–0.000) and TGF-β2 (r=−0.100 to –0.173, all P = 0.029–0.000) and a positive correlation between BDR and serum TGF-β1 (r=0.245−0.365, all P=0.000). After adjustment for age and BMI, there were no statistically significant correlations between serum levels of OPG or TGF-β2 and BDR. However, statistically significant correlations between serum TGF-β1 and BDR at the lumbar spine and ultradistal forearm remained. Multiple linear regression stepwise analysis showed that serum OPG could explain 1.4–3.7% of BDR variation. Serum TGF-β1 was a positive determinant of BDR and could explain 5.3–13.3% of BDR variation
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