Recent Developments of Systemic Chemotherapy for Gastric Cancer

Gastric cancer (GC) is a molecularly heterogeneous disease. Its molecular background, epidemiology, and standard of care are quite different between Eastern and Western countries. Many efforts have been made in developing more effective surgeries and adjuvant chemotherapies for resectable GC in each region. Recently, an intensive combination of cytotoxic agents has been established as a new standard of adjuvant treatment. Meanwhile, palliative chemotherapy is a uniform standard treatment for unresectable GC worldwide. Recently, one of the most remarkable advances in therapy for unresectable GC has been the approval of immune checkpoint inhibitors (ICIs). The use of ICIs as frontline treatment is currently being investigated. In addition, novel combinations of ICIs and targeted drugs are being evaluated in clinical trials. Despite these advances, the complex biology of GC has resulted in the failure of targeted therapies, with the exceptions of HER2-targeted trastuzumab and VEGFR2-targeted ramucirumab. GC harbors many redundant oncogenic pathways, and small subsets of tumors are driven by different specific pathways. Therefore, a combination strategy simultaneously inhibiting several pathways and/or stricter patient selection for better response to targeted drugs are needed to improve clinical outcomes in this field

Spectral Evolution of the Unusual Slow Nova V5558 Sgr

We report on the spectral evolution of the enigmatic, very slow nova V5558 Sgr, based on the low-resolution spectra obtained at the Fujii-Bisei Observatory and the Bisei Astronomical Observatory, Japan during a period of 2007 April 6 to 2008 May 3. V5558 Sgr shows a pre-maximum halt and then several flare-like rebrightenings, which is similar to another very slow nova V723 Cas. In our observations, the spectral type of V5558 Sgr evolved from the He/N type toward the Fe II type during the pre-maximum halt, and then toward the He/N type again. This course of spectral transition was observed for the first time in the long history of the nova research. In the rebrightening stage after the initial brightness maximum, we could identify many emission lines accompanied by a stronger absorption component of the P-Cygni profile at the brightness maxima. We found that the velocity of the P-Cygni absorption component measured from the emission peak decreased at the brightness maxima. Furthermore, we compared the spectra of V5558 Sgr with V723 Cas, and other novae which exhibited several rebrightenings during the early phase.Comment: 8 pages, 7figures, accepted for publication in PAS

Temporal and Spatial Analyses of Spectral Indices of Nonthermal Emissions Derived from Hard X-Rays and Microwaves

We studied electron spectral indices of nonthermal emissions seen in hard X-rays (HXRs) and in microwaves. We analyzed 12 flares observed by the Hard X-ray Telescope aboard {\it Yohkoh}, Nobeyama Radio Polarimeters (NoRP), and the Nobeyama Radioheliograph (NoRH), and compared the spectral indices derived from total fluxes of hard X-rays and microwaves. Except for four events, which have very soft HXR spectra suffering from the thermal component, these flares show a gap $\Delta\delta$ between the electron spectral indices derived from hard X-rays $\delta_{X}$ and those from microwaves $\delta_{\mu}$ ($\Delta\delta = \delta_{X} - \delta_{\mu}$) of about 1.6. Furthermore, from the start to the peak times of the HXR bursts, the time profiles of the HXR spectral index $\delta_{X}$ evolve synchronously with those of the microwave spectral index $\delta_{\mu}$, keeping the constant gap. We also examined the spatially resolved distribution of the microwave spectral index by using NoRH data. The microwave spectral index $\delta_{\mu}$ tends to be larger, which means a softer spectrum, at HXR footpoint sources with stronger magnetic field than that at the loop tops. These results suggest that the electron spectra are bent at around several hundreds of keV, and become harder at the higher energy range that contributes the microwave gyrosynchrotron emission.Comment: 24 pages, 6 figures, accepted for publication in Ap

Qualitative Research on Japanese Elementary School Teachers and Assistant Language Teachers\u27 Perceptions About Foreign Language Activities : Transition of English Learning from Elementary School to Junior High School

本研究は，小学校教員とALT（外国語指導助手）の外国語活動に対する意識についての質的研究であり，両者の小中連携に対する認識を探索的に調査し，仮説を生成した。13名の外国語活動指導経験がある小学校教員（元教員を1名含む）と14名のALTにアンケート調査を行い，分析方法としてM-GTA（木下,2003）を使用し，事例数や具体数を研究目的と相関的に決定するためにSCQRM（西條,2007,2008）をメタ理論として用い，概念モデル（仮説）を作成した。分析の結果，小学校教員とALTは，共通して，外国語活動における「指導改善」「指導者の能力向上」「授業外での英語使用環境」が児童の中学校での経験をより良くするための方法として認識しているという仮説が生成された。しかし「授業改善」における文字指導に関しては，若干の温度差が見られた。小学校教員とALTは，共通して，中学校外国語科における「外国語活動への理解」「生徒の経験を踏まえた指導改善」が生徒の外国語活動での経験を活かす方法として認識しているという仮説が生成された。これらの仮説は暫定的なものであり，より多様で妥当性のある仮説を生成するためには，さらなる研究が必要である

Possible Charge-Exchange X-Ray Emission in the Cygnus Loop Detected with Suzaku

X-ray spectroscopic measurements of the Cygnus Loop supernova remnant indicate that metal abundances throughout most of the remnant's rim are depleted to about 0.2 times the solar value. However, recent X-ray studies have revealed in some narrow regions along the outermost rim anomalously "enhanced" abundances (up to about 1 solar). The reason for these anomalous abundances is not understood. Here, we examine X-ray spectra in annular sectors covering nearly the entire rim of the Cygnus Loop using Suzaku (21 pointings) and XMM-Newton (1 pointing). We find that spectra in the "enhanced" abundance regions commonly show a strong emission feature at about 0.7 keV. This feature is likely a complex of He-like O K(gamma + delta + epsilon), although other possibilities cannot be fully excluded. The intensity of this emission relative to He-like O Kalpha appears to be too high to be explained as thermal emission. This fact, as well as the spatial concentration of the anomalous abundances in the outermost rim, leads us to propose an origin from charge-exchange processes between neutrals and H-like O. We show that the presence of charge-exchange emission could lead to the inference of apparently "enhanced" metal abundances using pure thermal emission models. Accounting for charge-exchange emission, the actual abundances could be uniformly low throughout the rim. The overall abundance depletion remains an open question.Comment: Published in Ap

Optical–optical double-resonance dual-comb spectroscopy with pump-intensity modulation

We apply an intensity-modulation technique to dual-comb spectroscopy to improve its detection sensitivity. The scheme is demonstrated via Doppler-free optical–optical double-resonance spectroscopy of Rb by modulating the intensity of a pump laser with frequencies set at rates 3 times lower and 50,000 times higher than the difference in the repetition rates of the two frequency combs. The signal-to-noise ratios are enhanced by 3 and 6 times for slow and fast modulations, respectively, compared to those of conventional dual-comb spectroscopy without any intensity modulation. The technique is widely applicable to pump-probe spectroscopy with dual-comb spectroscopy and provides high detection sensitivity