3,901 research outputs found
A Clinical Study of the Pulse Wave Characteristics at the Three Pulse Diagnosis Positions of Chon, Gwan and Cheok
In this work, we analyze the baseline, signal strength, aortic augmentation index (AIx), radial AIx, time to reflection and P_T2 at Chon, Gwan, and Cheok, which are the three pulse diagnosis positions in Oriental medicine. For the pulse measurement, we used the SphygmoCor apparatus, which has been widely used for the evaluation of the arterial stiffness at the aorta. By two-way repeated measures analysis of variance, we tested two independent measurements for repeatability and investigated their mean differences among Chon, Gwan and Cheok. To characterize further the parameters that were shown to be different between each palpation position, we carried out Duncan's test for the multiple comparisons. The baseline and signal strength were statistically different (P < .05) among Chon, Gwan and Cheok, respectively, which supports the major hypothesis of Oriental medicine that all of the three palpation positions contain different clinical information. On the other hand, aortic AIx and time to reflection were found to be statistically different between Chon and the others, and radial AIx and P_T2 did not show any difference between pulse positions. In the clinical sense, however, the aortic AIx at each palpation position was found to fall within the 90% confidence interval of normal arterial compliance. The results of the multiple comparisons indicate that the parameters of arterial stiffness were independent of the palpation positions. This work is the first attempt to characterize quantitatively the pulse signals at Chon, Gwan and Cheok with some relevant parameters extracted from the SphygmoCor apparatus
30 inch Roll-Based Production of High-Quality Graphene Films for Flexible Transparent Electrodes
We report that 30-inch scale multiple roll-to-roll transfer and wet chemical
doping considerably enhance the electrical properties of the graphene films
grown on roll-type Cu substrates by chemical vapor deposition. The resulting
graphene films shows a sheet resistance as low as ~30 Ohm/sq at ~90 %
transparency which is superior to commercial transparent electrodes such as
indium tin oxides (ITO). The monolayer of graphene shows sheet resistances as
low as ~125 Ohm/sq with 97.4% optical transmittance and half-integer quantum
Hall effect, indicating the high-quality of these graphene films. As a
practical application, we also fabricated a touch screen panel device based on
the graphene transparent electrodes, showing extraordinary mechanical and
electrical performances
Driven Diffusion in the Two-Dimensional Lattice Coulomb Gas; A Model for Flux Flow in Superconducting Networks
We carry out driven diffusion Monte Carlo simulations of the two dimensional
classical lattice Coulomb gas in an applied uniform electric field, as a model
for vortex motion due to an applied d.c. current, in a periodic superconducting
network. A finite-size version of dynamic scaling is used to extract the
dynamic critical exponent z, and infer the non-linear response at the
transition temperature. We consider the f=0 and f=1/2 cases, corresponding to
no applied magnetic field, and to one half flux quantum per unit cell of the
network respectively.Comment: 25 pages, 7 figures (available from [email protected]),
RevTex3.0, URST12
Role of spinon and spinon singlet pair excitations on phase transitions in superconductors
We examine the roles of massless Dirac spinon and spin singlet pair
excitations on the phase transition in superconductors. Although the
massless spinon excitations in the presence of the spin singlet pair
excitations do not alter the nature of the phase transition at , that
is, the XY universality class, they are seen to induce an additional attractive
interaction potential between vortices, further stabilizing vortex-antivortex
pairs at low temperature for lightly doped high samples.Comment: 5 pages, 1 figur
GALEX Ultraviolet Photometry of Globular Clusters in M31
We present ultraviolet photometry for globular clusters (GCs) in M31 from 15
square deg of imaging using the Galaxy Evolution Explorer (GALEX). We detect
200 and 94 GCs with certainty in the near-ultraviolet (NUV; 1750 - 2750
Angstroms) and far-ultraviolet (FUV; 1350 - 1750 Angstroms) bandpasses,
respectively. Our rate of detection is about 50% in the NUV and 23% in the FUV,
to an approximate limiting V magnitude of 19. Out of six clusters with
[Fe/H]>-1 seen in the NUV, none is detected in the FUV bandpass. Furthermore,
we find no candidate metal-rich clusters with significant FUV flux, because of
the contribution of blue horizontal-branch (HB) stars, such as NGC 6388 and NGC
6441, which are metal-rich Galactic GCs with hot HB stars. We show that our
GALEX photometry follows the general color trends established in previous UV
studies of GCs in M31 and the Galaxy. Comparing our data with Galactic GCs in
the UV and with population synthesis models, we suggest that the age range of
M31 and Galactic halo GCs are similar.Comment: This paper will be published as part of the Galaxy Evolution Explorer
(GALEX) Astrophysical Journal Letters Special Issue. Links to the full set of
papers will be available at http://www.galex.caltech.edu/PUBLICATIONS/ after
November 22, 200
STK295900, a Dual Inhibitor of Topoisomerase 1 and 2, Induces G<inf>2</inf> Arrest in the Absence of DNA Damage
STK295900, a small synthetic molecule belonging to a class of symmetric bibenzimidazoles, exhibits antiproliferative activity against various human cancer cell lines from different origins. Examining the effect of STK295900 in HeLa cells indicates that it induces G2 phase arrest without invoking DNA damage. Further analysis shows that STK295900 inhibits DNA relaxation that is mediated by topoisomerase 1 (Top 1) and topoisomerase 2 (Top 2) in vitro. In addition, STK295900 also exhibits protective effect against DNA damage induced by camptothecin. However, STK295900 does not affect etoposide-induced DNA damage. Moreover, STK295900 preferentially exerts cytotoxic effect on cancer cell lines while camptothecin, etoposide, and Hoechst 33342 affected both cancer and normal cells. Therefore, STK295900 has a potential to be developed as an anticancer chemotherapeutic agent. © 2013 Kim et al
Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity
Broader applications of carbon nanotubes to real-world problems have largely gone unfulfilled
because of difficult material synthesis and laborious processing. We report high-performance
multifunctional carbon nanotube (CNT) fibers that combine the specific strength, stiffness, and
thermal conductivity of carbon fibers with the specific electrical conductivity of metals. These
fibers consist of bulk-grown CNTs and are produced by high-throughput wet spinning, the same
process used to produce high-performance industrial fibers. These scalable CNT fibers are
positioned for high-value applications, such as aerospace electronics and field emission, and can
evolve into engineered materials with broad long-term impact, from consumer electronics to
long-range power transmission
The Look-back Time Evolution of Far-Ultraviolet Flux from the Brightest Cluster Elliptical Galaxies at z < 0.2
We present the GALEX UV photometry of the elliptical galaxies in Abell
clusters at moderate redshifts (z < 0.2) for the study of the look-back time
evolution of the UV upturn phenomenon. The brightest elliptical galaxies (M_r <
-22) in 12 remote clusters are compared with the nearby giant elliptical
galaxies of comparable optical luminosity in the Fornax and Virgo clusters. The
sample galaxies presented here appear to be quiescent without signs of massive
star formation or strong nuclear activity, and show smooth, extended profiles
in their UV images indicating that the far-UV (FUV) light is mostly produced by
hot stars in the underlying old stellar population. Compared to their
counterparts in nearby clusters, the FUV flux of cluster giant elliptical
galaxies at moderate redshifts fades rapidly with ~ 2 Gyrs of look-back time,
and the observed pace in FUV - V color evolution agrees reasonably well with
the prediction from the population synthesis models where the dominant FUV
source is hot horizontal-branch stars and their progeny. A similar amount of
color spread (~ 1 mag) in FUV - V exists among the brightest cluster elliptical
galaxies at z ~ 0.1, as observed among the nearby giant elliptical galaxies of
comparable optical luminosity.Comment: Accepted for publication in the Special GALEX ApJ Supplement,
December 200
Epigenetic inactivation of the NORE1 gene correlates with malignant progression of colorectal tumors
<p>Abstract</p> <p>Background</p> <p>NORE1 (RASSF5) is a newly described member of the RASSF family with Ras effector function. <it>NORE1 </it>expression is frequently inactivated by aberrant promoter hypermethylation in many human cancers, suggesting that NORE1 might be a putative tumor suppressor. However, expression and mutation status of <it>NORE1 </it>and its implication in colorectal tumorigenesis has not been evaluated.</p> <p>Methods</p> <p>Expression, mutation, and methylation status of <it>NORE1A </it>and <it>NORE1B </it>in 10 cancer cell lines and 80 primary tumors were characterized by quantitative PCR, SSCP, and bisulfite DNA sequencing analyses. Effect of NORE1A and NORE1B expression on tumor cell growth was evaluated using cell number counting, flow cytometry, and colony formation assays.</p> <p>Results</p> <p>Expression of <it>NORE1A </it>and <it>NORE1B </it>transcript was easily detectable in all normal colonic epithelial tissues, but substantially decreased in 7 (70%) and 4 (40%) of 10 cancer cell lines and 31 (38.8%) and 25 (31.3%) of 80 primary carcinoma tissues, respectively. Moreover, 46 (57.6%) and 38 (47.5%) of 80 matched tissue sets exhibited tumor-specific reduction of <it>NORE1A </it>and <it>NORE1B</it>, respectively. Abnormal reduction of <it>NORE1 </it>was more commonly observed in advanced stage and high grade tumors compared to early and low grade tumors. While somatic mutations of the gene were not identified, its expression was re-activated in all low expressor cells after treatment with the demethylating agent 5-aza-dC. Bisulfite DNA sequencing analysis of 31 CpG sites within the promoter region demonstrated that abnormal reduction of <it>NORE1A </it>is tightly associated with promoter CpG sites hypermethylation. Moreover, transient expression and siRNA-mediated knockdown assays revealed that both NORE1A and NORE1B decrease cellular growth and colony forming ability of tumor cells and enhance tumor cell response to apoptotic stress.</p> <p><b>Conclusion</b></p> <p>Our data indicate that epigenetic inactivation of <it>NORE1 </it>due to aberrant promoter hypermethylation is a frequent event in colorectal tumorigenesis and might be implicated in the malignant progression of colorectal tumors.</p
A genome-wide association study identifies a breast cancer risk variant in ERBB4 at 2q34: results from the Seoul Breast Cancer Study
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