-
Huiming Zhang,
Zhongtao Zhang,
Lixue Xuan,
Shan Zheng,
Lei Guo,
Qimin Zhan,
Xiang Qu,
Baoming Zhang,
Yu Wang,
Xiang Wang,
Yongmei Song
[show abstract]
[hide abstract]
ABSTRACT: Luminal subtype breast cancer is defined as oestrogen receptor (ER)- and/or progesterone receptor (PR)- positive breast cancer. We detected the expression of ER-α, ER-Β1 and ER-Β2 in the tissue samples of invasive luminal subtype breast cancer patients, evaluated the correlations between these ER statuses and prognosis, and tried to clarify whether the status of ER-α isoforms provides clinically useful information further to what is already provided by the traditional ER-α/PR assay.
The expression of ER-α, ER-Β1 and ER-Β2 in the paraffin-embedded sections of 162 invasive luminal subtype breast cancer patients was detected with an immunohistochemical staining method. With mid-long-term follow-up, the features of ER-α, ER-Β1 and ER-Β2 status and the correlations between clinical characteristics and the prognosis were analysed.
ER-Β1-positive status was correlated with PR (rs=0.217, p<0.01). The median follow-up time was 92 months (range, 4-98 months). Univariate analysis suggested that ER-Β1 status was significantly correlated to diseasefree survival (DFS) time (log rank=3.98, p=0.046), especially in patients with positive lymph nodes (log rank=6.20, p=0.013). In patients with smaller tumour size (=20 mm), negative ER-Β2 status was significantly correlated to overall survival time (log rank=3.87, p=0.049).
In invasive luminal subtype breast cancers, ER-Β1 is correlated with good prognosis and could be regarded as one of the factors for evaluating DFS time, especially in lymph node-positive patients. There may be some interactions between ER-Β1 and PR. In clinical practice, besides routine detection of ER-α and PR in invasive luminal subtype breast cancers, immunohistochemical staining of ER-Β1 and ER-Β2 should be considered in order to achieve more useful information. Further studies are needed to confirm our findings.
Clinical and Translational Oncology 03/2012; 14(3):225-31. · 1.33 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Li-doped YBa2Cu3Oy crystals were fabricated by a typical top seed melt textured growth (MTG) method. The measured dc magnetization loops indicate that there is a very pronounced second peak in the field dependence of the critical current density for -axis. The complex ac susceptibility has been measured as a function of temperature at various dc fields, and frequencies, respectively. The irreversibility line shifts to lower temperature with increasing ac and dc fields, and with decreasing frequency. Based on the nonlinear flux diffusion theory and the Bean critical state, we analysed the measured ac susceptibility curves. The temperature, dc field and current density dependence of the effective pinning barrier follows the form of , where μ = 0.13 is consistent with the theoretical predictions indicating that a vortex-glass phase is possible in the sample.
Superconductor Science and Technology 03/2006; 19(4):392. · 2.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Temperature-dependent current-voltage measurements combined with conductive atomic force microscopy and analytical modeling have been used to assess possible mechanisms of reverse-bias leakage current flow in Schottky diodes fabricated from GaN and Al <sub>0.25</sub> Ga <sub>0.75</sub> N / Ga N structures grown by molecular-beam epitaxy. Below 150 K , leakage current is nearly independent of temperature, indicating that conduction is dominated by tunneling transport. At higher temperatures, leakage current in both GaN and Al <sub>0.25</sub> Ga <sub>0.75</sub> N / Ga N diode structures is well described by a Frenkel-Poole emission model. Based on the inferred emission barrier heights and the observation that room-temperature leakage current is dominated by the presence of highly conductive dislocations, it is suggested that the key carrier transport process is emission of electrons from a trap state near the metal-semiconductor interface into a continuum of states associated with each conductive dislocation. In this model for leakage current flow, the emission barrier heights measured for the GaN and Al <sub>0.25</sub> Ga <sub>0.75</sub> N / Ga N diode structures indicate that the conductive dislocation states are aligned in energy between GaN and Al <sub>0.25</sub> Ga <sub>0.75</sub> N .
Journal of Applied Physics 02/2006; · 2.17 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An approach for reducing reverse-bias leakage currents in Schottky contacts formed to nitride semiconductor heterostructures grown by molecular-beam epitaxy is described, demonstrated, and analyzed. By incorporation of a GaN cap layer atop a conventional AlxGa1−xN/GaN heterostructure field-effect transistor epitaxial layer structure, the direction of the electric field at the metal-semiconductor interface of a Schottky contact is reversed, resulting in a suppression of electron flow into conductive screw dislocations that are known to dominate reverse-bias leakage currents in nitride semiconductors grown by molecular-beam epitaxy. Analysis of temperature-dependent current-voltage characteristics indicates that, in structures incorporating a GaN cap layer, reverse-bias leakage currents are reduced by one to three orders of magnitude, with the mechanism for leakage current flow differing from that established previously for the more conventional structure due to the alteration in the electric field at the metal-semiconductor interface. Scanned probe measurements of local, nanoscale current distributions confirm directly that current flow via conductive dislocations is suppressed in structures incorporating the GaN cap layer.
Journal of Applied Physics 01/2006; 99(1):014501-014501-6. · 2.17 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The nature of the large slip areas (asperities) of the fault is
uncertain. Asperities are common in the case of some large or
moderate-sized interplate recurrent earthquake pairs along the plate
boundary in NE Japan (Okada et al., 2003, Yamanaka and Kikuchi, 2003,
Hasegawa et al., 2004, Matsuzawa et al., 2004). These observations
suggest that the asperities are persistent features that would reflect
some physical properties on the fault plane. To study this phenomenon,
we obtained the seismic velocity structure around the fault plane of the
1995 southern Hyogo (Kobe) earthquake (M7.3) in southwestern Japan. We
adopted the double-difference (DD) tomography method (Zhang and Thurber,
2003), which has the advantage of obtaining the high-resolution seismic
velocity structure in and around the focal area. The inversion uses
23,228 P-wave and 18,902 S-wave arrival times from 915 earthquakes
recorded by a dense temporary seismic network (Hirata et al., 1996) for
aftershocks and seismic networks routinely operated by Kyoto University,
University of Tokyo and Kochi University. We inverted the velocity
model with a grid interval of 3 km in and around the focal area.
Obtained results are summarized as follows: (1) Low velocity zones of a
few kilometers wide are distributed along the fault or along the
aftershock alignment. This suggests that the fault plane of the present
earthquake is located in a low velocity zone. (2) The velocities of
this low velocity zone vary along the strike of the fault plane. We
compared the seismic velocity distribution along the fault plane with
the slip distribution obtained by seismic and geodetic inversions
(Yoshida et al., 1996). Large slip areas (asperities) correspond to
relatively high velocity areas on the fault plane. We also have obtained
the seismic velocity model in and around the focal area of other two
large shallow inland earthquakes (2000 M7.3 western Tottori and 2003
M6.4 northern Miyagi earthquakes) that occurred recently in Japan, using
DD tomography. The correspondence between asperities and high velocity
zones was also observed for these two events.
AGU Fall Meeting Abstracts. 11/2004; -1:01.
-
[show abstract]
[hide abstract]
ABSTRACT: A physical vapor transport (PVT) system has been designed and fabricated for growing SiC single crystals. Novel multisegmented graphite insulation has been used for improved heat containment in the hotzone. Numerical modeling was applied to obtain the temperature field inside the hotzone, which also helped in predicting various growth parameters. Single crystals of 6H SiC were grown by the modified Lely method using the PVT system developed in the laboratory. The grown crystals were subjected to preliminary characterization.
Review of Scientific Instruments 09/2004; 75(9):2843-2847. · 1.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In SiC vapor growth, micropipes and dislocations that originate at the seed/boule interface can continuously propagate into the newly grown crystal and adversely affect the quality of the crystals. The defect density can be reduced by the method of growing a large diameter crystal from a small seed through lateral growth under controlled thermal environment. In this paper, SiC growth processes with varying thermal conditions have been simulated; the shapes of the as-grown crystals are predicted and the thermo-elastic stress fields in the crystals are calculated to describe the dislocation density distributions. The simulation results show that if thermal conditions are properly controlled, it is possible to reduce the micropipe density through lateral growth without increasing basal plane dislocation density. The effects of operational parameters such as the axial and radial temperature gradients and seed mounting technique on the size and quality of the crystals are also investigated. The ceramic polycrystalline material that grows on the crystal periphery is illustrated to jeopardize the quality of the crystals. In addition, the influences of some geometrical parameters on thermal environments in the growth chamber are also analyzed. The current finding can also help in the design of AlN/GaN growth system.
Journal of Crystal Growth 01/2003; 258:318-330. · 1.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigate the effect of Ca doping on the electronic transport properties and superconductivity of Pr1−xCaxBa1.8Sr0.2Cu3Oy and Pr1−xCaxSr2Cu2.7Mo0.3Oy systems. It is found that when PrBa2Cu3Oy (Pr123) is in a highly localized state, the Ca doping mainly decreases the 4f-2p hybridized states and thus releases the holes into the CuO2 planes. Whereas when Pr123 is in a less localized state, the Ca doping not only introduces holes into the CuO2 planes, but also induces dramatic charge transfer. Our results suggest that only when the hole concentration in both the CuO chain and the CuO2 planes reaches a proper value, can the superconductivity be restored in the Pr123 system.
Superconductor Science and Technology 10/2002; 15(11):1519. · 2.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: For a few carbazole-related compounds in alcoholic solution, photoinduced solute−solvent proton-transfer dynamics are studied by means of femto- and picosecond fluorescence transient measurements. The investigated compounds show two emission bands, the F1 band (band maximum between 25 500 and 23 000 cm-1) that had previously been attributed to the normal solute−solvent complex and the F2 band (band maximum between 17 200 and 14 400 cm-1) that had previously been ascribed to the solute−solvent complex in its tautomeric form. Our data show that the F1 band fluorescence decay contains two fast decay components (the first of these has a time constant between 0.6 and 0.9 ps, the second has a characteristic time between 6.0 and 11 ps) and a slower decay component with a time constant between 50 and 150 ps, depending on the compound and the solvent. The F2 band shows a fast biexponential rise, which occurs at the same rate as the fast initial decay of the F1 band emission, followed by a slow decay of about 150−250 ps, depending on the compound and the solvent. The fast decay and rise components of the F1 and F2 band emissions, respectively, are discussed as being characteristic of the intermolecular double proton transfer within two distinct “cyclic” solute−solvent complexes. The slower decay component (50−150 ps) in the F1 band emission is attributed to the decay of the “blocked” solute−solvent complex that does not exhibit intermolecular proton transfer. In deuterated small-molecule alcohols, deuteron transfer is found for one cyclic solute−solvent species only. Its transfer rate appears to be temperature-dependent. The results are suggestive of a thermally averaged deuteron tunneling process in the cyclic solute−solvent complex.
The Journal of Physical Chemistry A 07/2000; 104:7167-7175. · 2.95 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Low-temperature thermal expansion and its correlation with oxygen nonstoichiometry have been studied for Bi1.7Pb0.3Sr2Ca2Cu3O10+y samples. An anomalously big jump of the thermal expansion in the c direction of Bi1.7Pb0.3Sr2Ca2Cu3O10+y has been observed at a temperature slightly above the superconductivity transition temperature. The corresponding temperature and the magnitude of the jump are found to be correlated with the oxygen nonstoichiometry, carrier concentration and superconductivity. The results reveal that the anomalously big jump of the thermal expansion is an electron-assisted lattice softening transition. Its correlation with the superconductivity suggests that phonon-electron interaction still plays a certain role in the superconductivity in high-Tc cuprates.
Superconductor Science and Technology 12/1999; 12(12):1163. · 2.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Intramolecular excited state double proton-transfer dynamics has been studied for [2,2‘-bipyridyl]-3,3‘-diol (BP(OH)2) in sol−gel glass. By means of the femtosecond fluorescence up-conversion technique, the spectral dependence of the fluorescence transients obtained for BP(OH)2 in a few sol−gel glasses has been followed. From the temporal behavior of the reconstructed spectra, two concurrent double proton-transfer pathways are concluded to occur in the sol−gel hosts: the first is a concerted double proton-transfer process (within 100 fs after the excitation pulse) and the second is a two-step process involving the reaction from the excited dienol-to-monoketo tautomer (<100 fs), followed by the monoketo-to-diketo step (with a time constant of a few ps). The proton-transfer dynamics has been studied in the sol−gels TMSPM and TMOS, both as a function of the temperature and as a function of the wavelength of the excitation pump pulses. In the sol−gel TMSPM, the proton-transfer dynamics in photoexcited BP(OH)2 is faster than the dynamics of the solute in TMOS and also faster than that in liquid solution (as known from our previous work). In the sol−gel TMOS, which contains residual amounts of methanol and water, the proton-transfer dynamics is found to be influenced by the solvation of the BP(OH)2 solute to the nearby layers of methanol and water. In the two-step process, the ratio of the yields of the monoketo and diketo tautomers is significantly reduced when excitation is to lower excited-state energies. It is discussed that this effect is typical of an energy barrier in the dienol-to-monoketo reaction pathway, the barrier height being more pronounced in the TMSPM glass than in the case of the TMOS glass (300 cm-1). At higher excitation energies, the results for the ratio of the yields of the monoketo and diketo tautomers are suggestive of additional dark processes due to coupling to the rigid sol−gel network.
10/1998;
-
[show abstract]
[hide abstract]
ABSTRACT: Numerical simulations are performed for Bridgman crystal growth of several semiconductor materials, such as InAs, InSb, GaSe, CdTe, PbTe, and GaP. For materials with low Prandtl and low Grashof numbers, melt convection is weak and the traditional Bridgman technique is a suitable growth process. For the materials with high Prandtl numbers in their melt status and the growth system with high Grashof number, the temperature field and the growth interface are significantly influenced by melt flow, resulting in the complicated flow pattern and curved interface shape. A new Bridgman crystal growth system is proposed to suppress convection and improve solidification interface shape by cooling of the top melt. The results obtained from the proposed design demonstrate that melt convection may be controlled by adjusting the design parameters. Further, parametric studies are performed to determine the influence of the control parameters on melt flow and solidification interface.
International Journal of Heat and Mass Transfer.
-
[show abstract]
[hide abstract]
ABSTRACT: Clinical evidence has shown a correlation between Parkinson's disease (PD) and Type 2 Diabetes (T2D), as abnormal glucose tolerance has been reported in > 50% of PD patients. The development of insulin resistance and the degeneration of nigrostriatal dopamine (DA) neurons are both mediated by oxidative mechanisms, and oxidative stress is likely a mechanistic link between these pathologies. Although glucose uptake in neuronal tissues is primarily non-insulin dependent, proteins involved in insulin signaling, such as insulin receptor substrate 2 (IRS2) and glucose transporter 4 (GLUT4), are present in the basal ganglia. The purpose of this study was to determine whether nigrostriatal DA depletion affects measures of insulin resistance in the striatum. Six weeks after 6-hydroxydopamine (6-OHDA) infusion into the medial forebrain bundle, rats were classified as having either partial (20–65%) or severe (90–99%) striatal DA depletion. Increased IRS2 serine phosphorylation, a marker of insulin resistance, was observed in the DA-depleted striatum. Additionally, severe depletion resulted in decreased total IRS2, indicating possible degradation of the protein. Decreased phosphorylation of AKT and expression of the kinase glycogen synthase kinase-3 alpha (GSK3-α) was also measured in the striatum of severely DA-depleted animals. Finally, expression of heat shock protein 25 (Hsp25), which is protective against oxidative damage and can decrease stress kinase activity, was decreased in the striatum of lesioned rats. Together, these results support the hypothesis that nigrostriatal DA depletion impairs insulin signaling in the basal ganglia.
Brain Research.
-
[show abstract]
[hide abstract]
ABSTRACT: The use of a cage of metallic wires as a bead is proposed to measure the higher order modes (HOMs) in an X-band accelerating structure. These long thin wires can isolate the longitudinal electric field component from other field components and produce sufficient frequency shift in bead-pull measurements. In the setup described in this paper, the bead is made by sputtering silver film onto a thin nylon line through a specially designed fixture. The cage has a size of approximately 0.5 mm in diameter, 2 mm in length and more than six metallic wires of less than 0.1 mm in width. The fabrication and calibration of the cage are described. The longitudinal electric fields of the lowest passband dipole mode TM1 1 0 in a 30 cm long X-band structure are measured by bead-pull measurements. Results are compared with the calculated ones obtained from URMELT-code.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
-
[show abstract]
[hide abstract]
ABSTRACT: Substituent alloys of Mg1−xMxB2 with M=Ti, Zr, Mo, Mn, Fe, Ca, Al, Ag, Cu, Y, and Ho and 0⩽x⩽10% have been synthesized by the solid-state reaction. The solid solubility for most of these dopants at Mg site is found to be very low except for M=Al. In most of these alloys, the Vegard relationship holds as the doping level is low. The lattice constants for the fictitious compounds such as AgB2, CuB2, FeB2 have been extrapolated. The superconductivity transition temperature, Tc, shows a systematic changes with the doping level in some of these substituent alloys. Relevant mechanisms of superconductivity suppression have been discussed.
Physica C: Superconductivity.
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper, a hot wire calibrator, which can travel at a constant and low speed ranging from 0 to 350mm/s, with an accuracy of ± 1mm/s, has been designed and constructed. The calibrator has also been used to counter check the accuracy of the hot wire calibration method. Preliminary measurements of the low speed tunnel with the calibrated hot wire, indicate that the tunnel is suitable for low speed experiment.
International Communications in Heat and Mass Transfer.
-
J. Breitweg,
M. Derrick,
D. Krakauer,
S. Magill,
D. Mikunas,
B. Musgrave,
J. Repond,
R. Stanek,
R.L. Talaga,
R. Yoshida, [......],
W.H. Smith,
A. Vaiciulis,
M. Wodarczyk,
A. Deshpande,
S. Dhawan,
V.W. Hughes,
S. Bhadra,
W.R. Frisken,
M. Khakzad,
W.B. Schmidke
[show abstract]
[hide abstract]
ABSTRACT: A global event shape analysis of the multihadronic final states observed in neutral current deep inelastic scattering events with a large rapidity gap with respect to the proton direction is presented. The analysis is performed in the range and , where Q2 is the virtuality of the photon and W is the virtual-photon proton centre of mass energy. Particular emphasis is placed on the dependence of the shape variables, measured in the γ∗–pomeron rest frame, on the mass of the hadronic final state, MX. With increasing MX the multihadronic final state becomes more collimated and planar. The experimental results are compared with several models which attempt to describe diffractive events. The broadening effects exhibited by the data require in these models a significant gluon component of the pomeron.
Physics Letters B.
-
J. Breitweg,
M. Derrick,
D. Krakauer,
S. Magill,
D. Mikunas,
B. Musgrave,
J. Repond,
R. Stanek,
R.L. Talaga,
R. Yoshida, [......],
R.J. Loveless,
S. Mattingly,
D.D. Reeder,
W.H. Smith,
A. Vaiciulis,
M. Wodarczyk,
S. Bhadra,
W.R. Frisken,
M. Khakzad,
W.B. Schmidke
[show abstract]
[hide abstract]
ABSTRACT: Inclusive photoproduction of D∗± in ep collisions at HERA has been measured with the ZEUS detector for photon-proton centre of mass energies in the range 115 < W < 280 GeV and photon virtuality 2 < 4 GeV2. The cross section integrated over the kinematic region and −1.5 < ηD∗ < 1.0 is (10.6 ± 1.7 (stat.) ±1.31.6 (syst.)) nb. Differential cross sections as functions of , ηD∗ and W are given. The data are compared with two next-to-leading or perturbative QCD predictions. For a calculation using a massive charm scheme the predicted cross sections are smaller than the measured ones. A recent calculation using a massless charm scheme is in agreement with the data.
Physics Letters B.
-
J Breitweg,
M Derrick,
D Krakauer,
S Magill,
D Mikunas,
B Musgrave,
J Repond,
R Stanek,
R.L Talaga,
R Yoshida, [......],
R.J Loveless,
S Mattingly,
D.D Reeder,
W.H Smith,
A Vaiciulis,
M Wodarczyk,
S Bhadra,
W.R Frisken,
M Khakzad,
W.B Schmidke
[show abstract]
[hide abstract]
ABSTRACT: Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of x and Q2 using the ZEUS detector. The evolution of the scaled momentum, xp, with Q2, in the range 10 to 1280 GeV2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2.
Physics Letters B.
-
[show abstract]
[hide abstract]
ABSTRACT: Aristolochic acid (AA), the active compound found in Aristolochia extracts, has been used as a traditional medicine. However, products containing AA were withdrawn from the market in the early 1980s because AA was found to be a potent carcinogen. Some genotoxicity studies of AA were conducted after the carcinogenicity of AA was reported. The purpose of this study was to check the ability of simplified, screening tests for genotoxicity to indicate the genotoxic activities of AA. Four commonly used in vitro genotoxicity endpoints were examined. In a bacterial mutation screening test, AA was mutagenic to tester strains TA98 and TA100 with and without rat liver S9. In the L5178Y mouse lymphoma cell gene mutation test, mutagenic activity was observed at ⩾25 μg/ml with or without S9. A concentration-dependent increase in structural chromosome aberrations was observed in CHO cells, with significant increases at 50 μg/ml without S9 and at 25 μg/ml with S9. Significant increases in micronucleated binucleated cells were observed in CHO cells treated with AA at ⩾25 μg/ml with or without S9. These results demonstrated that the genotoxicity of AA would have been easily detected if simple screening versions of in vitro genotoxicity assays had been used during early product development. It is suggested that simplified screening tests such as those used in this study would be a rapid and economical way of obtaining the preliminary genotoxicity profiles of new substances or products as an aid to decision-making for further development.
Food and Chemical Toxicology.
