469 research outputs found
Clinicopathologic significance of sialyl Le xexpression in advanced gastric carcinoma
Sialyl Lewis xantigen (SLX) is a carbohydrate antigen that serves as a ligand for selectin, an adhesion molecule expressed on vascular endothelial cells. The expression of SLX in 245 patients with advanced gastric carcinoma was examined immunohistochemically, and its clinicopathologic significance was analysed. We classified the patients with advanced gastric carcinoma into 91 with differentiated type and 154 with undifferentiated type. SLX expressed in 135 of 245 patients (55%), comprising 68 (75%) patients with differentiated carcinoma and 67 (44%) with undifferentiated carcinoma. The positive rate for SLX expression was significantly higher among patients with differentiated carcinoma than among those in undifferentiated carcinoma (Pâ<â0.0001). With differentiated carcinoma, the incidence of lymph node metastasis, advanced tumour stage (stage III and IV) and liver recurrence was significantly higher in SLX-positive patients than in SLX-negative ones (Pâ <â.0001, Pâ=â0.0065 and Pâ=â0.028, respectively). Moreover, the prognoses were better in patients with SLX-negative tumours than in those with SLX-positive tumours (P = 0.019). With undifferentiated carcinoma, there were no significant correlations between SLX expression and any clinicopathological features or prognoses. The clinicopathologic significance of SLX expression in gastric carcinoma patients depends on histologic type. SLX expression may be of great relevance in predicting liver metastases in patients with differentiated carcinoma. © 2000 Cancer Research Campaign http://www.bjcancer.co
Measurement of Transmission of Electron Heating Wave through the Fundamental Resonance region at the Plug of GAMMA 10
XMM-Newton observations of the Galactic Supernova Remnant CTB 109 (G109.1-1.0)
We present the analysis of the X-ray Multi-Mirror Mission (XMM-Newton)
European Photon Imaging Camera (EPIC) data of the Galactic supernova remnant
(SNR) CTB 109 (G109.1-1.0). CTB 109 is associated with the anomalous X-ray
pulsar (AXP) 1E 2259+586 and has an unusual semi-circular morphology in both
the X-ray and the radio, and an extended X-ray bright interior region known as
the `Lobe'. The deep EPIC mosaic image of the remnant shows no emission towards
the west where a giant molecular cloud complex is located. No morphological
connection between the Lobe and the AXP is found. We find remarkably little
spectral variation across the remnant given the large intensity variations. All
spectra of the shell and the Lobe are well fitted by a single-temperature
non-equilibrium ionization model for a collisional plasma with solar abundances
(kT = 0.5 - 0.7 keV, tau = n_e t = 1 - 4 x 10^11 s cm^-3, N_H = 5 - 7 x 10^21
cm^-2). There is no indication of nonthermal emission in the Lobe or the shell.
We conclude that the Lobe originated from an interaction of the SNR shock wave
with an interstellar cloud. Applying the Sedov solution for the undisturbed
eastern part of the SNR, and assuming full equilibration between the electrons
and ions behind the shock front, the SNR shock velocity is derived as v_s = 720
+/- 60 km s^-1, the remnant age as t = (8.8 +/- 0.9) x 10^3 d_3 yr, the initial
energy as E_0 = (7.4 +/- 2.9) x 10^50 d_3^2.5 ergs, and the pre-shock density
of the nuclei in the ambient medium as n_0 = (0.16 +/- 0.02) d_3^-0.5 cm^-3, at
an assumed distance of D = 3.0 d_3 kpc. Assuming CTB 109 and 1E 2259+586 are
associated, these values constrain the age and the environment of the
progenitor of the SNR and the pulsar.Comment: Accepted for publication in ApJ. 9 figures. Figs. 1 + 2 are in color
(fig1.jpg, fig2.jpg
Excitation Characteristics of Nonlinear Electromagnetic and Electrostatic Waves Due to High Power Plug ECRH
Constraints on Thermal Emission Models of Anomalous X-ray Pulsars
Thermal emission from the surface of an ultramagnetic neutron star is
believed to contribute significantly to the soft X-ray flux of the Anomalous
X-ray Pulsars. We compare the detailed predictions of models of the surface
emission from a magnetar to the observed properties of AXPs. In particular, we
focus on the combination of their luminosities and energy-dependent pulsed
fractions. We use the results of recent calculations for strongly magnetized
atmospheres to obtain the angle- and energy-dependence of the surface emission.
We include in our calculations the effects of general relativistic photon
transport and interstellar extinction. We find that the combination of the
large pulsed fractions and the high luminosities of AXPs cannot be accounted
for by surface emission from a magnetar with two antipodal hot regions or a
temperature distribution characteristic of a magnetic dipole. This result is
robust for reasonable neutron star radii, for the range of magnetic field
strengths inferred from the observed spin down rates, and for surface
temperatures consistent with the spectral properties of AXPs. Models with a
single hot emitting region can reproduce the observations, provided that the
distance to one of the sources is ~30% less than the current best estimate, and
allowing for systematic uncertainties in the spectral fit of a second source.
Finally, the thermal emission models with antipodal emission geometry predict a
characteristic strong increase of the pulsed fraction with photon energy, which
is apparently inconsistent with the current data. The energy-dependence of the
pulsed fraction in the models with one hot region shows a wider range of
behavior and can be consistent with the existing data. Upcoming high-resolution
observations with Chandra and XMM-Newton will provide a conclusive test.Comment: 25 preprint pages, 7 color figures, ApJ, in pres
Large-scale mapping observations of the CI(3P1-3P0) and CO(J=3-2) lines toward the Orion A molecular cloud
Large scale mapping observations of the 3P1-3P0 fine structure transition of
atomic carbon (CI, 492 GHz) and the J=3-2 transition of CO (346 GHz) toward the
Orion A molecular cloud have been carried out with the Mt. Fuji
submillimeter-wave telescope. The observations cover 9 square degrees, and
include the Orion nebula M42 and the L1641 dark cloud complex. The CI emission
extends over almost the entire region of the Orion A cloud and is surprisingly
similar to that of 13CO(J=1-0).The CO(J=3-2) emission shows a more featureless
and extended distribution than CI.The CI/CO(J=3-2) integrated intensity ratio
shows a spatial gradient running from the north (0.10) to the south (1.2) of
the Orion A cloud, which we interpret as a consequence of the temperature
gradient. On the other hand, the CI/13CO(J=1-0) intensity ratio shows no
systematic gradient. We have found a good correlation between the CI and
13CO(J=1-0) intensities over the Orion A cloud. This result is discussed on the
basis of photodissociation region models.Comment: Text file is 13 pages long, and 3 figure files (pdf format). NRO
Report No. 508 (1999). University of Tokyo, Resceu 41/9
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