1,598 research outputs found
Prognostic Value of Metastatic No.8p LNs in Patients with Gastric Cancer
Background. To evaluate prognostic value of metastatic No.8p LNs in patients with gastric cancer. Methods. From August 2002 to December 2011, a total of 284 gastric cancer patients who underwent gastrectomy with No.8p LNs dissection were analyzed retrospectively in this study. Patients were divided into two groups according to the status of No.8p LNs. Clinicopathological features were collected to conduct the correlation analysis. Follow-up was carried out up to December 31st, 2014. Overall survival was analyzed. Results. Out of 284 patients, metastatic No.8p LNs were found in 24 (8.5%) patients. Compared with other 260 cases, these patients suffered morphologically larger tumor (P=0.003), node stage (P=0.000), and metastatic stage (P=0.000). The 3-year overall survival rate was 26% in No.8p-positive group and 53% in No.8p-negative group. No significant difference of cumulative survival rates existed between the No.8p-positive group and No.8p-negative stage IV group (26% versus 28%, P=0.923). Patients with other distant metastasis or not in No.8p+ group had similar cumulative survival rates (24% versus 28%, P=0.914). Conclusions. Positive No.8p LNs were a poor but not an independent prognostic factor for patients with GC and should be recognized as distant metastasis
Impact of combinations of time-delay interferometry channels on stochastic gravitational wave background detection
The method of time delay interferometry (TDI) is proposed to cancel the laser
noise in space-borne gravitational-wave detectors. Among all different TDI
combinations, the most commonly used ones are the orthogonal channels A, E and
T, where A and E are signal-sensitive and T is signal-insensitive. Meanwhile,
for the detection of stochastic gravitational-wave background, one needs to
introduce the overlap reduction function to characterize the correlation
between channels. For the calculation of overlap reduction function, it is
often convenient to work in the low-frequency approximation, and assuming the
equal-arm Michelson channels. However, if one wishes to work on the overlap
reduction function of channels, then the low-frequency approximation
fails. We derive the exact form of overlap reduction function for
channels. Based on the overlap reduction function, we calculate the sensitivity
curves of TianQin, TianQin I+II and TianQin + LISA. We conclude that the
detection sensitivity calculated with channels is mostly consistent
with that obtained from the equal-arm Michelson channels.Comment: 18 pages,10 figure
Constraints on the cosmological parameters with three-parameter correlation of Gamma-ray bursts
As one of the most energetic and brightest events, gamma-ray bursts (GRBs)
can be treated as a promising probe of the high-redshift universe. Similar to
type Ia supernovae (SNe Ia), GRBs with same physical origin could be treated as
standard candles. We select GRB samples with the same physical origin, which
are divided into two groups. One group is consisted of 31 GRBs with a plateau
phase feature of a constant luminosity followed by a decay index of about -2 in
the X-ray afterglow light curves, and the other has 50 GRBs with a shallow
decay phase in the optical light curves. For the selected GRB samples, we
confirm that there is a tight correlation between the plateau luminosity ,
the end time of plateau and the isotropic energy release
. We also find that the correlation is
insensitive to the cosmological parameters and no valid limitations on the
cosmological parameters can be obtained using this correlation. We explore a
new three-parameter correlation , , and the spectral peak energy in
the rest frame (), and find that this correlation
can be used as a standard candle to constrain the cosmological parameters. By
employing the optical sample only, we find the constraints of for a flat CDM model. For the
non-flat CDM model, the best-fitting results are , . For the combination of the X-ray and optical
smaples, we find for a flat
CDM model, and , for a non-flat CDM model.Comment: Accepted for publication in The Astrophysical Journal, 13 pages, 9
figures and 2 table
Direct observation of the formation and stabilization of metallic nanoparticles on carbon supports
Direct formation of ultra-small nanoparticles on carbon supports by rapid high temperature synthesis method offers new opportunities for scalable nanomanufacturing and the synthesis of stable multi-elemental nanoparticles. However, the underlying mechanisms affecting the dispersion and stability of nanoparticles on the supports during high temperature processing remain enigmatic. In this work, we report the observation of metallic nanoparticles formation and stabilization on carbon supports through in situ Joule heating method. We find that the formation of metallic nanoparticles is associated with the simultaneous phase transition of amorphous carbon to a highly defective turbostratic graphite (T-graphite). Molecular dynamic (MD) simulations suggest that the defective T-graphite provide numerous nucleation sites for the nanoparticles to form. Furthermore, the nanoparticles partially intercalate and take root on edge planes, leading to high binding energy on support. This interaction between nanoparticles and T-graphite substrate strengthens the anchoring and provides excellent thermal stability to the nanoparticles. These findings provide mechanistic understanding of rapid high temperature synthesis of metal nanoparticles on carbon supports and the origin of their stability
Measuring the Hubble Constant Using Strongly Lensed Gravitational Wave Signals
The measurement of the Hubble constant plays an important role in the
study of cosmology. In this letter, we propose a new method to constrain the
Hubble constant using the strongly lensed gravitational wave (GW) signals. By
reparameterizing the waveform, we find that the lensed waveform is sensitive to
the . Assuming the scenario that no electromagnetic counterpart of the GW
source can be identified, our method can still give meaningful constraints on
the with the information of the lens redshift. We then apply Fisher
information matrix and Markov Chain Monte Carlo to evaluate the potential of
this method. For the space-based GW detector, TianQin, the can be
constrained within a relative error of 0.3-2\%, using a single strongly
lensed GW event. Precision varies according to different levels of
electromagnetic information.Comment: 8 pages, 4 figure
Toward Dendrite-Free Metallic Lithium Anodes: From Structural Design to Optimal Electrochemical Diffusion Kinetics
Radio Plateaus in Gamma-Ray Burst Afterglows and Their Application in Cosmology
The plateau phase in the radio afterglows has been observed in very few
gamma-ray bursts (GRBs), and 27 radio light curves with plateau phase were
acquired from the published literature in this article. We obtain the related
parameters of the radio plateau, such as temporal indexes during the plateau
phase ( and ), break time (\Tbz) and the corresponding
radio flux (). The two parameter Dainotti relation between the break
time of the plateau and the corresponding break luminosity (\Lbz) in radio
band is \Lbz \propto \Tbz^{-1.20\pm0.24}. Including the isotropic energy
\Eiso and the peak energy \Epi, the three parameter correlations for the
radio plateaus are written as \Lbz \propto \Tbz^{-1.01 \pm 0.24} \Eiso^{0.18
\pm 0.09} and \Lbz \propto \Tbz^{-1.18 \pm 0.27} \Epi^{0.05 \pm 0.28},
respectively. The correlations are less consistent with that of X-ray and
optical plateaus, implying that radio plateaus may have a different physical
mechanism. The typical frequencies crossing the observational band may be a
reasonable hypothesis that causes the breaks of the radio afterglows. We
calibrate GRBs empirical luminosity correlations as standard candle for
constraining cosmological parameters, and find that our samples can constrain
the flat CDM model well, while are not sensitive to non-flat
CDM model. By combining GRBs with other probes, such as SN and CMB,
the constraints on cosmological parameters are \om = 0.297\pm0.006 for the
flat CDM model and \om = 0.283\pm0.008, \oL = 0.711\pm0.006 for
the non-flat CDM model, respectively.Comment: 16 pages, 6 figures and 6 tables, accepted for publication in Ap
Effects of temperature and wavelength choice on in-situ dissolution test of Cimetidine tablets
AbstractThe effects of temperature and wavelength choice on in-situ dissolution test instrument of Cimetidine were studied. Absorbance (A)<1.0 is required when using a fiber-optic dissolution test system. The detection wavelength of λmax (218nm) was replaced by 244nm to carry out this test. The absorbance of Cimetidine solution at different temperature showed an obvious change. Calibration of Cimetidine solution should be tested at the same temperature (37°C) with the test solution. A suitable wavelength with smaller tangent slope could be chosen for in-situ dissolution test of Cimetidine tablets
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