Flight Performance of the AKARI Cryogenic System

We describe the flight performance of the cryogenic system of the infrared astronomical satellite AKARI, which was successfully launched on 2006 February 21 (UT). AKARI carries a 68.5 cm telescope together with two focal plane instruments, Infrared Cameras (IRC) and Far Infrared Surveyor (FIS), all of which are cooled down to cryogenic temperature to achieve superior sensitivity. The AKARI cryogenic system is a unique hybrid system, which consists of cryogen (liquid helium) and mechanical coolers (2-stage Stirling coolers). With the help of the mechanical coolers, 179 L (26.0 kg) of super-fluid liquid helium can keep the instruments cryogenically cooled for more than 500 days. The on-orbit performance of the AKARI cryogenics is consistent with the design and pre-flight test, and the boil-off gas flow rate is as small as 0.32 mg/s. We observed the increase of the major axis of the AKARI orbit, which can be explained by the thrust due to thermal pressure of vented helium gas.Comment: 19 pages, 10 figures, and 6 tables. Accepted for publication in the AKARI special issue of the Publications of the Astronomical Society of Japa

キョダイ チョクチョウ gastrointestinal stromal tumor（GIST） ノ 1セツジョレイ

A 75-year old woman, complaining of prolapse of the uterus, was detected a giant tumor in therectum by abdominal CT scan. Enhanced CT revealed a heterogeneous mass in the pelvic cavitymeasuring 8 cm. MRI demonstrated a mass in the rectovaginal seputum, showing heterogeneoushigh intensity on T1 and T2 weighed image. Abdominoperineal excision of the rectum was performed.Macroscopically, the resected specimen showed a solid tumor with central hemorrhagicnecrosis, 10×5 cm in size. Histological examination showed fascicular proliferated spindle-shapedcells invaded to subserosa. Immunohistochemical studies showed a GIST of the rectum withpositive staining for c-kit and CD34, and negative staining for α-SMA, S-100 protein. No evidenceof recurrence has been found in the 2 years since. We report a case of giant GIST of the rectum.Because the risk of the recurrence depends on operation curability adequate resection margin isneeded for surgical approach for GIST

The Far-Infrared Surveyor (FIS) for AKARI

The Far-Infrared Surveyor (FIS) is one of two focal plane instruments on the AKARI satellite. FIS has four photometric bands at 65, 90, 140, and 160 um, and uses two kinds of array detectors. The FIS arrays and optics are designed to sweep the sky with high spatial resolution and redundancy. The actual scan width is more than eight arcmin, and the pixel pitch is matches the diffraction limit of the telescope. Derived point spread functions (PSFs) from observations of asteroids are similar to the optical model. Significant excesses, however, are clearly seen around tails of the PSFs, whose contributions are about 30% of the total power. All FIS functions are operating well in orbit, and its performance meets the laboratory characterizations, except for the two longer wavelength bands, which are not performing as well as characterized. Furthermore, the FIS has a spectroscopic capability using a Fourier transform spectrometer (FTS). Because the FTS takes advantage of the optics and detectors of the photometer, it can simultaneously make a spectral map. This paper summarizes the in-flight technical and operational performance of the FIS.Comment: 23 pages, 10 figures, and 2 tables. Accepted for publication in the AKARI special issue of the Publications of the Astronomical Society of Japa

ヒト乳癌細胞株（YMB-1）の樹立とその特性

A continuous cell line (YMB-1), derived from a primary breast cancer lesion has been established and maintained in culture for the past 9 months. Cell colonies consist of polygonal epithelial cells containing junctional complexes and tubular formation. The cell population doubling time is 44 hr and the saturation density at confluency is 2.5×10^5 cells/cm2. The chromosome modal number is 73 and 3 marker chromosomes are visible. Both cytosol estrogen and androgen receptors are present. However, the cytosol progesterone receptor was not detected by the dextran coated chacoal method. The s. c. injection of 5×10^6 cells from cell culuture into nude mice induced a tumor. Both the spillage method and cell separation by specific gravity were employed to remove fibroblasts