122 research outputs found
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
Customized chemotherapy based on epidermal growth factor receptormutation status for elderly patients with advanced non-small-cell lung cancer: a phase II trial
BACKGROUND: Elderly patients are more vulnerable to toxicity from chemotherapy. Activating epidermal growth factor receptor (EGFR) mutations in non-small-cell lung cancer (NSCLC) are associated with enhanced response to EGFR tyrosine-kinase inhibitors. We studied patients with advanced NSCLC for whom treatment was customized based on EGFR mutation status. METHODS: We screened 57 chemotherapy-naïve patients with histologically or cytologically confirmed NSCLC, stage IIIB or IV, aged 70 years or older, and with an Eastern Cooperative Oncology Group performance status 0 or 1, for EGFR exon 19 codon 746–750 deletion and exon 21 L858R mutation. Twenty-two patients with EGFR mutations received gefitinib; 32 patients without mutations received vinorelbine or gemcitabine. The primary endpoint was the response rate. RESULTS: The response rate was 45.5% (95% confidence interval [CI]: 24.4%, 67.8%) in patients with EGFR mutations and 18.8% (95% CI: 7.2%, 36.4%) in patients without EGFR mutations. The median overall survival was 27.9 months (95%CI: 24.4 months, undeterminable months) in patients with EGFR mutations and 14.9 months (95%CI: 11.0 months, 22.4 months) in patients without EGFR mutations. In the gefitinib group, grade 3/4 hepatic dysfunction and dermatitis occurred in 23% and 5% of patients, respectively. In patients treated with vinorelbine or gemcitabine, the most common grade 3 or 4 adverse events were neutropenia (47%; four had febrile neutropenia), anemia (13%), and anorexia (9%). No treatment-related deaths occurred. CONCLUSIONS: Treatment customization based on EGFR mutation status deserves consideration, particularly for elderly patients who often cannot receive second-line chemotherapy due to poor organ function or comorbidities. TRIAL REGISTRATION: This trial is registered at University hospital Medical Information Network-clinical trial registration (http://www.umin.ac.jp/ctr/index/htm) with the registration identification number C000000436
AKARI infrared imaging of reflection nebulae IC4954 and IC4955
We present the observations of the reflection nebulae IC4954 and IC4955
region with the Infrared Camera (IRC) and the Far-Infrared Surveyor (FIS) on
board the infrared astronomical satellite AKARI during its performance
verification phase. We obtained 7 band images from 7 to 160um with higher
spatial resolution and higher sensitivities than previous observations. The
mid-infrared color of the S9W (9um) and L18W (18um) bands shows a systematic
variation around the exciting sources. The spatial variation in the
mid-infrared color suggests that the star-formation in IC4954/4955 is
progressing from south-west to north-east. The FIS data also clearly resolve
two nebulae for the first time in the far-infrared. The FIS 4-band data from
65um to 160um allow us to correctly estimate the total infrared luminosity from
the region, which is about one sixth of the energy emitted from the existing
stellar sources. Five candidates for young stellar objects have been detected
as point sources for the first time in the 11um image. They are located in the
red S9W to L18W color regions, suggesting that current star-formation has been
triggered by previous star-formation activities. A wide area map of the size of
about 1 x 1 (deg^2) around the IC4954/4955 region was created from the AKARI
mid-infrared all-sky survey data. Together with the HI 21cm data, it suggests a
large hollow structure of a degree scale, on whose edge the IC4954/4955 region
has been created, indicating star formation over three generations in largely
different spatial scales.Comment: 23 pages, 7 figures, accepted for publication in PASJ AKARI special
issu
Vasorelaxant activity of indole alkaloids from Tabernaemontana dichotoma.
The aim of this study was to search for bioactive natural products from medicinal plants targeting vasorelaxant activity and we found the methanol extract from bark of Tabernaemontana dichotoma showed vasorelaxant activity on rat aorta. We isolated eight indole alkaloids including 10-methoxyalstonerine (1), a new macroline type indole alkaloid, from bark of T. dichotoma. These were respectively identified as 10-methoxyaffinisine (2), lochnerine (3), cathafoline (4), (−)-alstonerine (5), 19,20-dehydro-10-methoxytalcarpine (6), alstonisine (7), and alstonal (8) based on spectroscopic analysis. Among them, sarpagine type (2 and 3), akuammiline type (4), and macroline oxindole type (7 and 8) showed potent vasorelaxant activity. Mechanism of action on vasorelaxant activity of 10-methoxyaffinisine (2), cathafoline (4), and alstonisine (7) was clarified. Effects of 10-methoxyaffinisine (2), cathafoline (4), and alstonisine (7) were partially mediated the NO release from endothelial cells. Furthermore, 10-methoxyaffinisine (2) and alstonisine (7) attribute to the inhibitory effect of VDC and ROC, and cathafoline (4) have inhibitory effect on Ca2+ influx via ROC. In addition, 10-methoxyaffinisine (2) as a major compound from bark of T. dichotoma showed hypotensive effect on normotensive rats in vivo
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