687 research outputs found
Non-thermal radiation of black hole off canonical typicality
We study the Hawking radiation of black holes by considering the canonical
typicality. For the universe consisting of black holes and their outer part, we
directly obtain a non-thermal radiation spectrum of an arbitrary black hole
from its entropy, which only depends on a few external qualities (known as
hairs), such as mass, charge, and angular momentum. Our result shows that the
spectrum of the non-thermal radiation is independent of the detailed quantum
tunneling dynamics across black hole horizon. We prove that the black hole
information paradox is naturally resolved by taking account the correlation
between black hole and its radiation in our approach.Comment: 5 pages, 1 figure, pulished on Europhysics Letters, comments are
welcome
miR-1258: a novel microRNA that controls TMPRSS4 expression is associated with malignant progression of papillary thyroid carcinoma
Background: MicroRNA-1258 (miR-1258) has been shown to play an anti-cancer role in a variety of cancers, but its relationship with papillary thyroid cancer (PTC) has not been reported. The emphasis of this research was to reveal the biological function of miR-1258 in PTC and its potential mechanisms. Material and methods: We measured miR-1258 expression in PTC cells and the transfection efficiency of miR-1258 mimic and miR-1258 inhibitor by quantitative real-time PCR (qRT-PCR) assay. Cell Counting Kit-8 assay (CCK8) and Transwell experiments were conducted to examine the influences of altering miR-1258 expression on the viability, migration, and invasion of PTC cells. Bioinformatics prediction and dual-luciferase experiment were performed to verify the target gene of miR-1258. Finally, we carried out a rescue assay to verify whether the regulation of miR-1258 on the biological behaviour of PTC cells needs to be achieved by regulating TMPRSS4. Results: The outcomes revealed that miR-1258 was lowly expressed in PTC cell lines and miR-1258 showed the lowest expression in KTC-1 and the highest expression in B-CPAP among all tested PTC cell lines. Overexpression of miR-1258 inhibited KTC-1 cell viability and ability to migrate and invade, whereas inhibition of miR-1258 in B-CPAP cells has the opposite effect. Furthermore, we affirmed that miR-1258 can directly target TMPRSS4, and miR-1258 can reduce the biological malignant behaviour of PTC cells via regulation of TMPRSS4. Conclusion: Taken together, our research raised the possibility that miR-1258 was an anti-oncogene, which exerts its anti-cancer function by targeting TMPRSS4. Hence, it may be possible to treat PTC by targeting the miR-1258/TMPRSS4 axis in the future.
Enhanced electrochemical performance of CuCo2S4/carbon nanotubes composite as electrode material for supercapacitors
CuCo2S4 is regarded as a promising electrode material for supercapacitor, but has inferior conductivity and poor cycle stability which restrict its wide-range applications. In this work, hierarchically hybrid composite of CuCo2S4/carbon nanotubes (CNTs) was synthesized using a facile hydrothermal and sulfuration process. The embedded CNTs in the CuCo2S4 matrix provided numerous effective paths for electron transfer and ion diffusion, and thus promoted the faradaic reactions of the CuCo2S4 electrode in the energy storage processes. The CuCo2S4/CNTs-3.2% electrode exhibited a significantly increased specific capacitance of 557.5 F g-1 compared with those of the pristine CuCo2S4 electrode (373.4 F g-1) and CuO/Co3O4/CNTs-3.2% electrode (356.5 F g-1) at a current density of 1 A g-1. An asymmetric supercapacitor (ASC) was assembled using the CuCo2S4/CNTs-3.2% as the positive electrode and the active carbon as the negative electrode, which exhibited an energy density of 23.2 Wh kg-1 at a power density of 402.7 W kg-1. Moreover, the residual specific capacitance of this ASC device retained 85.7 % of its original value after tested for 10000 cycles, indicating its excellent cycle stability
Theaflavin Ameliorates Cerebral Ischemia-Reperfusion Injury in Rats Through Its Anti-Inflammatory Effect and Modulation of STAT-1
Theaflavin, a major constituent of black tea, possesses biological functions such as the antioxidative, antiviral, and anti-inflammatory ones. The purpose of this study was to verify whether theaflavin reduces focal cerebral ischemia injury in a rat model of middle cerebral artery occlusion (MCAO). Male Sprague-Dawley rats were anesthetized and subjected to 2 hours of MCAO followed 24 hours reperfusion. Theaflavin administration (5, 10, and 20 mg/kg, IV) ameliorated infarct and edema volume. Theaflavin inhibited leukocyte infiltration and expression of ICAM-1, COX-2, and iNOS in injured brain. Phosphorylation of STAT-1, a protein which mediates intracellular signaling to the nucleus, was enhanced 2-fold over that of sham group and was inhibited by theaflavin. Our study demonstrated that theaflavin significantly protected neurons from cerebral ischemia-reperfusion injury by limiting leukocyte infiltration and expression of ICAM-1, and suppressing upregulation of inflammatory-related prooxidative enzymes (iNOS and COX-2) in ischemic brain via, at least in part, reducing the phosphorylation of STAT-1
The Research of Missing Value Estimation of Gene Sequence Based on Improved KNN
Gene based data mining has been received wider and wider attention as gene carries genetic information of living creature. While mining gene information, one of the tasks is to estimate the missing values reasonably and effectively, so as to reflect the original information of gene sequence. By analyzing the theory of KNN (K nearest neighbor algorithm), an improved KNN for gene sequence was proposed, which resolves the problem of missing values while mining gene data. Results show the feasibility of the algorithm with experiments using data from genbank
Abundance Analysis of Barium Stars
We obtain the chemical abundances of six barium stars and two CH subgiant
stars based on the high signal-to-noise ratio and high resolution Echelle
spectra. The neutron capture process elements Y, Zr, Ba, La, Eu show obvious
overabundance relative to the Sun, for example, their [Ba/Fe] values are from
0.45 to 1.27. Other elements, including Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn,
Ni, show comparable abundances to the Solar ones, and their [Fe/H] cover a
range from 0.40 to 0.21, which means they belong to Galactic disk. The
predicts of the theoretical model of wind accretion for binary systems can
explain the observed abundance patterns of the neutron capture process elements
in these stars, which means that their overabundant heavy-elements could be
caused by accreting the ejecta of AGB stars, the progenitors of the present
white dwarf companions in the binary systems.Comment: 24 pages, 6 figures, accepted for publication in ChJA
Using Rhodamine 123 Accumulation in CD8+ Cells as a Surrogate Indicator to Study the P-Glycoprotein Modulating Effect of Cepharanthine Hydrochloride In Vivo
The purpose of this study was the use of rhodamine 123 (Rho123) accumulation in peripheral blood CD8+cells as a surrogate indicator to evaluate the modulating effect of P-glycoprotein (P-gp) inhibitors in the multidrug resistance (MDR) tumor-bearing mouse model. Rho123 was administered to mice, and the fluorescence level in CD8+ cells was measured. Cepharanthine hydrochloride (CH) and verapamil (VER), two P-gp inhibitors, were administered to mice 1 hour prior to Rho123 administration in vivo or added to peripheral blood 1 hour prior to Rho123 addition ex vivo. The tumor inhibition effect of 5-fluorouracil/adriamycin/cisplatin (FAP) protocol plus CH was also investigated. A concentration- or dose-response relationship was shown between the concentration and dose of CH and Rho123 accumulation or the antitumor activity. In conclusion, the measurement of Rho123 accumulation in CD8+ cells provides a surrogate assay for the screening of candidate P-gp inhibitors in preclinical trials, and CH is effective in modulating P-gp-mediated MDR in vivo
Susceptibility Scanning as Failure Analysis Tool for System-Level Electrostatic Discharge (ESD) Problems
Susceptibility scanning is an increasingly adopted method for root cause analysis of system-level immunity sensitivities. It allows localizing affected nets and integrated circuits (ICs). Further, it can be used to compare the immunity of functionally identical or similar ICs or circuit boards. This paper explains the methodology as applied to electrostatic discharge and provides examples of scan maps and signals probed during immunity scanning. Limitations of present immunity analysis methods are discussed
Scale-free download network for publications
The scale-free power-law behavior of the statistics of the download frequency
of publications has been, for the first time, reported. The data of the
download frequency of publications are taken from a well-constructed web page
in the field of economic physics (http://www.unifr.ch/econophysics/). The
Zipf-law analysis and the Tsallis entropy method were used to fit the download
frequency. It was found that the power-law exponent of rank-ordered frequency
distribution is which is consistent with the
power-law exponent for the cumulated frequency
distributions. Preferential attachment model of Barabasi and Albert network has
been used to explain the download network.Comment: 3 pages, 2 figure
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