Hideki Takami
A5103260763- Stellar, planetary, and galactic studies
- Pancreatic and Hepatic Oncology Research
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Pancreatitis Pathology and Treatment
- Gastric Cancer Management and Outcomes
- Neuroendocrine Tumor Research Advances
- Cancer-related gene regulation
- Cancer Genomics and Diagnostics
- Astrophysical Phenomena and Observations
- Inflammatory Biomarkers in Disease Prognosis
- Renal cell carcinoma treatment
- Gallbladder and Bile Duct Disorders
- Epigenetics and DNA Methylation
- Molecular Spectroscopy and Structure
- RNA modifications and cancer
- Esophageal Cancer Research and Treatment
- Platelet Disorders and Treatments
- Esophageal and GI Pathology
- Advanced optical system design
- Cholangiocarcinoma and Gallbladder Cancer Studies
- Gastrointestinal Tumor Research and Treatment
- Cancer Cells and Metastasis
Nagoya University
2016-2025
National Astronomical Observatory of Japan
2012-2024
Seirei Hamamatsu General Hospital
2024
Nagoya University Hospital
2017-2024
National Institute of Information and Communications Technology
2024
National Institutes of Natural Sciences
2008-2020
The Graduate University for Advanced Studies, SOKENDAI
2006-2020
Hirosaki University
1998-2019
University of Occupational and Environmental Health Japan
2017-2018
Institute of Astronomy and Astrophysics, Academia Sinica
2017
We present high-resolution, H-band, imaging observations, collected with Subaru/HiCIAO, of the scattered light from transitional disk around SAO 206462 (HD 135344B). Although previous sub-mm imagery suggested existence dust-depleted cavity at r~46AU, our observations reveal presence components as close 0.2" (~28AU) star. Moreover, we have discovered two small-scale spiral structures lying within 0.5" (~70AU). models for using density wave theory, and derive a aspect ratio h~0.1, which is...
Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range ages (<50 Myr) and atmospheric properties, with temperatures 800--1800 K very red colors (J - H > 0.5 mag), implying thick cloud covers. Furthermore, substantial model uncertainties exist these young due to the unknown initial conditions formation, which can lead an order magnitude uncertainty in modeled planet mass. Here, we report direct imaging discovery Jovian...
We report high-resolution 1.6 $\micron$ polarized intensity ($PI$) images of the circumstellar disk around Herbig Ae star AB Aur at a radial distance 22 AU ($0."15$) up to 554 (3.$"$85), which have been obtained by high-contrast instrument HiCIAO with dual-beam polarimetry. revealed complicated and asymmetrical structures in inner part ($\lesssim$140 AU) disk, while confirming previously reported outer ($r$ $\gtrsim$200 spiral structure. imaged double ring structure $\sim$40 $\sim$100...
We present the first near-IR scattered light detection of transitional disk associated with Herbig Ae star MWC 758 using data obtained as part Strategic Exploration Exoplanets and Disks Subaru, 1.1 micron HST/NICMOS data. While sub-millimeter studies suggested there is a dust-depleted cavity r=0.35, we find close 0.1 (20-28 AU) from star, no visible at H, K', or Ks. two small-scaled spiral structures which asymmetrically shadow outer disk. model one spirals density wave theory, derive aspect...
Objective: Given the frequent adverse events with multidrug chemotherapy, not only survival benefit but also feasibility of using neoadjuvant chemotherapy to treat pancreatic cancer need be clarified. Summary Background Data: Although development regimens has improved outcomes patients unresectable cancer, benefits these treatments in neo-adjuvant setting remain controversial. Methods: Patients borderline-resectable were enrolled and randomly assigned receive either FOLFIRINOX or gemcitabine...
We present the direct imaging discovery of an extrasolar planet, or possible low-mass brown dwarf, at a projected separation 55 +/- 2 AU (1.058 0.007 arcsec) from B9-type star Kappa And. The planet was detected with Subaru/HiCIAO during SEEDS survey, and confirmed as bound companion via common proper motion measurements. Observed near-infrared magnitudes J = 16.3 0.3, H 15.2 0.2, Ks 14.6 0.4, L' 13.12 0.09 indicate temperature ~1700 K. galactic kinematics host are consistent membership in...
We present high resolution H-band polarized intensity (PI; FWHM = 0."1: 14 AU) and L'-band imaging data (FWHM 0."11: 15 of the circumstellar disk around weak-lined T Tauri star PDS 70 in Centaurus at a radial distance 28 AU (0."2) up to 210 (1."5). In both images, giant inner gap is clearly resolved for first time, radius ~70 AU. Our show that geometric center shifts by ~6 toward minor axis. confirm brown dwarf companion candidate north background based on its proper motion. As result SED...
Evidence indicates that impaired immunocompetence and nutritional status adversely affect short-term long-term outcomes of patients with cancer. We aimed to evaluate the clinical significance preoperative according Onodera's prognostic nutrition index (PNI) among who underwent curative gastrectomy for gastric cancer (GC). This study included 260 stage II/III GC R0 resection. The predictive values postoperative outcome (morbidity prognosis) were evaluated. PNI was calculated as follows: 10 ×...
We present a new Subaru/HiCIAO high-contrast H-band polarized intensity (PI) image of nearby transitional disk associated with TW Hydrae. The scattered light from the was detected 0.2" to 1.5" (11 - 81 AU) and PI shows clear axisymmetric depression in at ~ 0.4" (~ 20 central star, similar 80 AU gap previously reported HST images. Azimuthal profile also beyond is almost axisymmetric. discuss two possible scenarios explaining origin depression: 1) structure may exist star because shallow slope...
Transitional circumstellar disks around young stellar objects have a distinctive infrared deficit 10 μm in their spectral energy distributions, recently measured by the Spitzer Infrared Spectrograph (IRS), suggesting dust depletion inner regions. These been confirmed to giant central cavities imaging of submillimeter continuum emission using Submillimeter Array (SMA). However, polarized near-infrared scattered light images for most systematic IRS/SMA cross sample, obtained HiCIAO on Subaru...
We present results from the first three years of observations moving group targets in SEEDS high-contrast imaging survey exoplanets and disks using Subaru telescope. achieve typical contrasts ~10^5 at 1" ~10^6 beyond 2" around 63 proposed members nearby kinematic groups. review each associations to which our belong, concluding that five, \beta Pictoris (~20 Myr), AB Doradus (~100 Columba (~30 Tucana-Horogium TW Hydrae (~10 are sufficiently well-defined constrain ages individual targets....
We conduct a statistical analysis of combined sample direct imaging data, totalling nearly 250 stars. The stars cover wide range ages and spectral types, include five detections ($\kappa$ And b, two $\sim$60 M$_{\rm J}$ brown dwarf companions in the Pleiades, PZ Tel B, CD$-$35 2722B). For some analyses we add currently unpublished set SEEDS observations, including GJ 504b 758B. uniform, Bayesian all stellar using both membership kinematic moving group activity/rotation age indicators. then...
We present H- and Ks-band imaging data resolving the gap in transitional disk around LkCa 15, revealing surrounding nebulosity. detect sharp elliptical contours delimiting nebulosity on inside as well outside, consistent with shape, size, ellipticity, orientation of starlight reflected from far-side wall, whereas near-side wall is shielded view by disk's optically thick bulk. note that forward scattering surface could provide an alternate interpretation In either case, this discovery...
The current status of commissioning and recent results in performance Subaru laser guide star adaptive optics system is presented. After the first light using natural stars with limited configuration October 2006, we concentrated to complete a final for serve AO188 an open use observation. On sky test full configurations started August 2008, opened public one month later. We continuously achieved around 0.6 0.7 Strehl ratio at K band bright 9th 10th magnitude R band. found unexpectedly large...
Subaru adaptive optics system (AO188) is an 188-elements curvature sensor that operated in both natural and laser guide star modes. AO188 was installed at Nasmyth platform of the telescope it has been successfully operating mode since October 2008. The performance well verified from on-sky data obtained with infrared camera spectrograph (IRCS). Under normal seeing condition, achieves K-band Strehl ratio between 60% 70% using R = 9.0 magnitude stars works faint down to 16.5 magnitude. We...
Through detailed radiative transfer modeling, we present a disk+cavity model to simultaneously explain both the spectral energy distribution (SED) and Subaru H-band polarized light imaging for pre-transitional protoplanetary disk PDS 70. In particular, are able match not only radial dependence but also absolute scale of surface brightness scattered light. Our has cavity 65 AU in radius, which is heavily depleted sub-micron-sized dust grains, small residual inner that produces weak still...
We report high-resolution (0.07 arcsec) near-infrared polarized intensity images of the circumstellar disk around star 2MASS J16042165-2130284 obtained with HiCIAO mounted on Subaru 8.2 m telescope. present our $H$-band data, which clearly exhibits a resolved, face-on large inner hole for first time at infrared wavelengths. detect centrosymmetric polarization pattern in material as has been observed other disks. Elliptical fitting gives semimajor axis, semiminor and position angle (P.A.) 63...
IRD is the near-infrared high-precision radial velocity instrument for Subaru 8.2-m telescope. It a relatively compact (~1m size) spectrometer with new echelle-grating and Volume-Phase Holographic gratings covering 1-2 micron wavelengths combined an original frequency comb using optical pulse synthesizer. The will employ 4096x4096-pixel HgCdTe array under testing at IfA, University of Hawaii. Both telescope/Adaptive Optics beams are fed to via fibers, while placed Nasmyth platform Expected...
We present Subaru/HiCIAO H-band high-contrast images of the debris disk around HIP 79977, whose pres- ence was recently inferred from an infrared excess. Our resolve for first time, allowing characterization its shape, size, and dust grain properties. use angular differential imaging (ADI) to reveal geometry in unpolarized light out a radius ~2", as well polarized (PDI) measure degree scattering polarization ~1.5". In order strike favorable balance between suppression stellar halo...
The formation scenario of a gapped disk, i.e., transitional and its asymmetry is still under debate. Proposed scenarios such as disk–planet interaction, photoevaporation, grain growth, anticyclonic vortex, eccentricity, their combinations would result in different radial distributions the gas small (sub-μm size) large (millimeter dust grains well asymmetric structures disk. Optical/near-infrared (NIR) imaging observations (sub-)millimeter interferometry can trace grains, respectively;...
The Infrared Doppler (IRD) instrument is a fiber-fed high-resolution NIR spectrometer for the Subaru telescope covering Y,J,H-bands simultaneously with maximum spectral resolution of 70,000. main purpose IRD search Earth-mass planets around nearby M-dwarfs by precise radial velocity measurements, as well spectroscopic characterization exoplanet atmospheres. We report current status instrument, which undergoing commissioning at Telescope, and first light observation successfully done in...
Abstract Background Intraperitoneal chemotherapy using paclitaxel is considered an experimental approach for treating peritoneal carcinomatosis. This study aimed to determine the recommended dose, and evaluate clinical efficacy safety, of combination intravenous gemcitabine, nab-paclitaxel intraperitoneal in patients with pancreatic cancer metastasis. Methods The frequencies dose-limiting toxicities were evaluated, dose was determined phase I. primary endpoint II analysis overall survival...
The objective of this study was to identify the most appropriate endoscopic biliary drainage method in patients with pancreatic head cancer.A prospectively collected database comprising 122 consecutive who underwent pancreatoduodenectomy, including 72 treated by retrograde (ERBD) and 50 nasobiliary (ENBD) procedures, analyzed.All bile cultures intraoperatively were positive ERBD group, rates fluid on postoperative days 1, 3, 5 incidence abdominal abscess formation significantly higher than...