Lymph Node Dissection along the Recurrent Laryngeal Nerve in Video-Assisted Thoracoscopic Surgery (VATSE) for Esophageal Squamous Cell Carcinoma

Esophageal carcinoma is the ninth most common cancer in the world, which is frequently seen in Asia and east Africa. Around 80% of all cases occurred in less-developed regions. Two major histological subtypes of esophageal carcinoma, adenocarcinoma and squamous cell carcinoma, are known to differ greatly in terms of risk factor, epidemiology, male to female ratios, and incidence. Lymph node metastasis is a crucial factor in staging and prognosis is associated with surgical treatment and a major lymphatic chain into the neck. Esophageal adenocarcinoma (EAC) is mainly detected at the lower third of the thoracic esophagus or esophago-gastric-junction (EGJ) and metastasizes mainly to lymph nodes of the lesser sac, celiac regions and lower mediastinal. Esophageal squamous cell carcinoma (ESCC) has a predilection for metastasis to the lymph nodes of the cervical region including recurrent laryngeal nerve (RLN) on both sides. Lymph node dissection is vital yet difficult, left-side lymph node dissection especially requires expertise. There are some reports on lymph node dissection in the prone position by video-assisted thoracoscopic surgery of the esophagus (VATS-E) along the left RLN in Japan and China. We also introduce a stripping method for lymph node dissection in this site

The Ejecta Distributions of the Heavy Elements in the Cygnus Loop

We analyzed the metal distribution of the Cygnus Loop using 14 and 7 pointings observation data obtained by the \textit{Suzaku} and the \textit{XMM-Newton} observatories. The spectral analysis shows that all the spectra are well fitted by the two-$kT_e$ non-equilibrium ionization plasma model as shown by the earlier observations. From the best-fit parameters of the high-$kT_e$ component, we calculated the emission measures about various elements and showed the metal distribution of the ejecta component. We found that the distributions of Si and Fe are centered at the southwest of the geometric center toward the blow-out region. From the best-fit parameters, we also estimated the progenitor mass of the Cygnus Loop from our field of view and the metal rich region with a radius of 25 arcmin from the metal center. The result from the metal circle is similar to that from our entire FOV, which suggests the mixing of the metal. From the results, we estimated the mass of the progenitor star at 12-15\MO.Comment: 15 pages, 5 figures, PASJ, Vol.61, No.

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A Suzaku Study of Ejecta Structure and Origin of Hard X-ray Emission in the Supernova Remnant G156.2+5.7

We report an X-ray study of the evolved Galactic supernova remnant (SNR) G156.2+5.7 based on six pointing observations with Suzaku. The remnant's large extent (100\arcmin in diameter) allows us to investigate its radial structure in the northwestern and eastern directions from the apparent center. The X-ray spectra were well fit with a two-component non-equilibrium ionization model representing the swept-up interstellar medium (ISM) and the metal-rich ejecta. We found prominent central concentrations of Si, S and Fe from the ejecta component; the lighter elements of O, Ne and Mg were distributed more uniformly. The temperature of the ISM component suggests a slow shock (610-960 km s$^{-1}$), hence the remnant's age is estimated to be 7,000-15,000 yr, assuming its distance to be $\sim$1.1 kpc. G156.2+5.7 has also been thought to emit hard, non-thermal X-rays, despite being considerably older than any other such remnant. In response to a recent discovery of a background cluster of galaxies (2XMM J045637.2+522411), we carefully excluded its contribution, and reexamined the origin of the hard X-ray emission. We found that the residual hard X-ray emission is consistent with the expected level of the cosmic X-ray background. Thus, no robust evidence for the non-thermal emission was obtained from G156.2+5.7. These results are consistent with the picture of an evolved SNR.Comment: 10 pages 8 figures, accepted for PAS

Temperature dependence of the impurity-induced resonant state in Zn-doped Bi_2Sr_2CaCu_2O8+δ_{8+\delta} by Scanning Tunneling Spectroscopy

We report on the temperature dependence of the impurity-induced resonant state in Zn-doped Bi_2Sr_2CaCu_2O$_{8+\delta}$ by scanning tunneling spectroscopy at 30 mK < T < 52 K. It is known that a Zn impurity induces a sharp resonant peak in tunnel spectrum at an energy close to the Fermi level. We observed that the resonant peak survives up to 52 K. The peak broadens with increasing temperature, which is explained by the thermal effect. This result provides information to understand the origin of the resonant peak.Comment: 4 pages, 3 figures, to appear in Phys. Rev.