Near-Ultraviolet and Visible Spectroscopy of HAYABUSA Spacecraft Re-entry

HAYABUSA is the first spacecraft ever to land on and lift off from any celestial body other than the moon. The mission, which returned asteroid samples to the Earth while overcoming various technical hurdles, ended on June 13, 2010, with the planned atmospheric re-entry. In order to safely deliver the sample return capsule, the HAYABUSA spacecraft ended its 7-year journey in a brilliant "artificial fireball" over the Australian desert. Spectroscopic observation was carried out in the near-ultraviolet and visible wavelengths between 3000 and 7500 \AA at 3 - 20 \AA resolution. Approximately 100 atomic lines such as Fe I, Mg I, Na I, Al I, Cr I, Mn I, Ni I, Ti I, Li I, Zn I, O I, and N I were identified from the spacecraft. Exotic atoms such as Cu I, Mo I, Xe I and Hg I were also detected. A strong Li I line (6708 \AA) at a height of ~55 km originated from the onboard Li-Ion batteries. The FeO molecule bands at a height of ~63 km were probably formed in the wake of the spacecraft. The effective excitation temperature as determined from the atomic lines varied from 4500 K to 6000 K. The observed number density of Fe I was about 10 times more abundant than Mg I after the spacecraft explosion. N2+(1-) bands from a shock layer and CN violet bands from the sample return capsule's ablating heat shield were dominant molecular bands in the near-ultraviolet region of 3000 - 4000 \AA. OH(A-X) band was likely to exist around 3092 \AA. A strong shock layer from the HAYABUSA spacecraft was rapidly formed at heights between 93 km and 83 km, which was confirmed by detection of N2+(1-) bands with a vibration temperature of ~13000 K. Gray-body temperature of the capsule at a height of ~42 km was estimated to be ~2437 K which is matched to a theoretical prediction. The final message of the HAYABUSA spacecraft and its sample return capsule are discussed through our spectroscopy.Comment: Accepted for publication in PASJ, 22 pages, 7 figures, 6 table

Preliminary results of phase I trial of oral uracil/tegafur (UFT), leucovorin plus irinotecan and radiation therapy for patients with locally recurrent rectal cancer

BACKGROUND: Surgical attempts for locally recurrent rectal cancer often fail due to local re-recurrence and distant metastasis. Preoperative chemoradiation may enhance better local control and survival. The aim of this study was to assess the safety of oral uracil and tegafur (UFT) plus leucovorin (LV), and irinotecan combined with radiation and determine the maximum-tolerated dose (MTD) and dose limiting toxicity (DLT) of the triple drug regimen. PATIENTS AND METHODS: Patients with locally recurrent rectal cancer received escalating doses of irinotecan on days 1, 8, 15, and 22 (starting at 30 mg/m(2), with 10 mg increments between consecutive cohorts) and fixed doses of UFT (300 mg/m(2)) plus LV (75 mg/day) on days 3 to 7, 10 to 14, 17 to 21, and 24 to 28. Radiation was given 5 days per week totaling 40 to 50 Gy (2Gy/day). RESULTS: Six patients were treated at the starting dose, and 2 received the full scheduled chemoradiotherapy. The other 4 patients had grade 3 diarrhea and diarrhea was the DLT. One patient had partial response and he had subsequently radical surgical resection. Median progression free survival for local recurrence was 320 days. CONCLUSION: Irinotecan plus UFT/LV with concomitant radiotherapy in patients with locally recurrent rectal cancer was not feasible due to diarrhea in this setting. Modification of the treatment is needed

ウリノキの雄薬数と花弁数

[雑録] Miscellaneous note

用語の混乱: 集合果 aggregate fruit と多花果 multiple fruit

[雑録] Miscellaneous note

Evaluation of two-dimensional electronic portal imaging device using integrated images during volumetric modulated arc therapy for prostate cancer

Background: The aim of the study was to evaluate analysis criteria for the identification of the presence of rectal gas during volumetric modulated arc therapy (VMAT) for prostate cancer patients by using electronic portal imaging device (EPID)-based in vivo dosimetry (IVD). Materials and methods: All measurements were performed by determining the cumulative EPID images in an integrated acquisition mode and analyzed using PerFRACTION commercial software. Systematic setup errors were simulated by moving the anthropomorphic phantom in each translational and rotational direction. The inhomogeneity regions were also simulated by the I’mRT phantom attached to the Quasar phantom. The presence of small and large air cavities (12 and 48 cm3) was controlled by moving the Quasar phantom in several timings during VMAT. Sixteen prostate cancer patients received EPID-based IVD during VMAT. Results: In the phantom study, no systematic setup error was detected in the range that can happen in clinical ( < 5-mm and < 3 degree). The pass rate of 2% dose difference (DD2%) in small and large air cavities was 98.74% and 79.05%, respectively, in the appearance of the air cavity after irradiation three quarter times. In the clinical study, some fractions caused a sharp decline in the DD2% pass rate. The proportion for DD2% < 90% was 13.4% of all fractions. Rectal gas was confirmed in 11.0% of fractions by acquiring kilo-voltage X-ray images after the treatment. Conclusions: Our results suggest that analysis criteria of 2% dose difference in EPID-based IVD was a suitable method for identification of rectal gas during VMAT for prostate cancer patients