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We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image using our two methods: random phase-free method and scaled ... diffraction. In order to record the entire image information on the encrypted image, the large-sized images require the random phase to widely diffuse the object light over the encrypted image; however, the random phase gives rise to the speckle noise on the decrypted images, and it may be difficult to recognize the decrypted images. In order to reduce the speckle noise, we apply our random phase-free method to the framework. In addition, we employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates. •We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image.•In order to reduce the speckle noise, we apply our random phase-free method to the framework.•We employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates. more

本研究は、2019年の台風Faxaiの発生に対する大気および海洋の寄与の定量化を行った。熱帯低気圧発生スコア（TGS）を用いた統計解析では、後に台風Faxaiに発達した熱帯擾乱（Pre-Faxai）が偏東風波動（EW）に起因することを示した。TGSグリッドバージョン解析によって評価したPre-Faxaiの発生領域平均のEWスコア（Grid-EW）は、気候値の約2倍であり、過去38年間でも2番目に大きな値であった。Pre-Faxaiの位置に対応する高Grid-EW領域は、2019年8月25日頃に北太平洋東部にまでさかのぼることができる。高Grid-EW領域は低気圧性循環を伴い、その循環中心では深い対流が立つことで湿潤域を維持していた。この高Grid-EW領域は、背景風により西へ移動して北太平洋西部に到達した。気象庁版SHIPS （TIFS ）により、Faxaiの発生に重要な環境場は、海洋と鉛直シアであることを示した。海洋条件はPre-Faxaiが北西太平洋上を移動するときから貢献していた。しかし、対流圏上層に発生した寒冷渦により、その地域の鉛直シアが増加して、一時的にPre-Faxaiの発達は抑制された。その後、寒冷渦の弱化に伴って鉛直シアが低下した9月4日に、Pre-Faxaiは熱帯低気圧の強さにまで達した。したがって、TGSとTIFSは台風Faxaiが発生する10日前にその予兆を検出しており、これらの手法を用いた偏東風波動や鉛直シアのモニタリングは防災のためにも重要である。

Abstract Background and purpose To determine the dose constraints for rectal bleeding in brachytherapy (BRT) combined with external beam radiotherapy (EBRT). Materials and methods Post-BRT, pelvic ... computed tomography images were used for subsequent EBRT planning and BRT postplans in 37 patients. The physical doses for each plan were converted to biologically effective doses, and corresponding voxel doses were integrated to plot the summed dose-volume histogram (sum-DVH). Between 5 patients with (bled-pts) and 32 without (spared-pts) grade 2 or 3 rectal bleeding, the differences in the mean minimal dose (rDn) covering the rectal volume of 0.5–10.0 cc and the rectal volume (rVn) receiving the calculated dose of 20–150 Gy were compared. Results The differences in the summed-rDn were determined by BRT exposure, while those of the summed-rVn were determined in the low-dose range and superimposed in the high-dose range by EBRT exposure. Of the 13 patients with rV150 of >1.2 cc, 4 were bled-pts (30.8%). Of the 24 patients with rV150 of ≦ 1.2 cc, 1 was a bled-pts (4.2%) ( p = 0.024; odds ratio, 10.2; CI (95%), 1.0–104.3). Conclusions The mono-scale DVH analysis is a promising method for exploring the threshold for rectal bleeding in combined radiotherapy. more

To measure X-ray spectra with high count rates, we developed a detector consisting of a Lu2(SiO4)O LSO crystal with a decay time of 40ns and a multipixel photon counter (MPPC). The photocurrents ... flowing through the MPPC are converted into voltages and amplified by a high-speed current–voltage amplifier, and event pulses from the amplifier are sent to a multichannel analyzer to measure spectra. We used three MPPCs of 100, 400 and 1600pixels/mm2, and the MPPCs were driven under pre-Geiger mode at a temperature of 20°C. At a tube voltage of 100kV and a tube current of 5.0μA, the maximum count rate was 12.8kilo-counts per second. The event-pulse widths were 200ns, and the energy resolution was 53% at 59.5keV using a 100-pixel MPPC. •Zero-dark-counting X-ray detection was performed under pre-Geiger mode.•200-ns-width event pulses were produced by a high-speed amplifier.•X-ray spectra were measured using three LSO-MPPC detectors.•Energy resolution improved with decreasing MPPC pixel number. more

X-ray photons are detected using a cerium-doped yttrium aluminum perovskite YAP(Ce) single-crystal scintillator with a decay time of 30 ns and a small-sized photomultiplier tube (SPMT). The negative ... output pulse from the SPMT is amplified by a high-speed inverse amplifier, and the event pulses are sent to a multichannel analyzer to measure X-ray spectra. The energy resolution of the spectrometer was 15% at 59.5 keV. We carried out photon-counting computed tomography using gadolinium media with a maximum rate of 650 kilo counts per second and confirmed the energy-dispersive effect with changes in the description voltage of event pulses using a high-speed comparator. more

To confirm the advantage of chemoradiotherapy using intra-arterial docetaxel with intravenous cisplatin and 5-fluorouracil. A total of 26 oropharyngeal cancer patients (1, 2, 2, and 21 patients had ... Stage I, II, III, and IVa-IVc, respectively) were treated with two sessions of this chemoradiotherapy regimen. External beam radiotherapy was delivered using large portals that included the primary site and the regional lymph nodes initially (range, 40-41.4 Gy) and the metastatic lymph nodes later (60 or 72 Gy). All tumor-supplying branches of the carotid arteries were cannulated, and 40 mg/m(2) docetaxel was individually infused on Day 1. The other systemic chemotherapy agents included 60 mg/m(2) cisplatin on Day 2 and 500 mg/m(2) 5-fluorouracil on Days 2-6. The primary response of the tumor was complete in 21 (81%), partial in 4 (15%), and progressive in 1 patient. Grade 4 mucositis, leukopenia, and dermatitis was observed in 3, 2, and 1 patients, respectively. During a median follow-up of 10 months, the disease recurred at the primary site and at a distant organ in 2 (8%) and 3 (12%) patients, respectively. Three patients died because of cancer progression. Two patients (8%) with a partial response were compromised by lethal bleeding from the tumor bed or chemotherapeutic toxicity. The 3-year locoregional control rate and the 3-year overall survival rate was 73% and 77%, respectively. This method resulted in an excellent primary tumor response rate (96%) and moderate acute toxicity. Additional follow-up is required to ascertain the usefulness of this modality. more

本研究は、2009年から2017年にかけて北西太平洋で発生した熱帯低気圧（TC）において、トロピカルストームの強度に発達する前に減衰した熱帯低気圧（TD）の特性と環境場の条件を調査した。特に、大規模な流れパターンと関連させて、トロピカルストームの強度まで発達した熱帯低気圧（TS）と比較した。流れパターンは以下の5つに分類した。シアライン（SL）、東西風合流域（CR）、モンスーンジャイア（GY）、偏東風波動（EW）、および既存のTCからのロスビー波応答で発生したパターン（PTC）である。ベストトラックデータと早期ドボラックデータを用いて、476例のTC事例のうち、263例のTDが検出された。CRまたはPTC（EW）のパターンで発生したTCは、他のパターンと比較してトロピカルストームの強度に達する（達しない）割合が多い。夏と秋のCR、GY、およびEW（PTC）のTDの平均位置は、同じパターンのTSよりも西（東および北）に偏っていた。TDの周囲の環境場パラメータはTSよりも発達に不向きな傾向があり、CR、EW、PTC（SL、GY、PTC）で大気（海洋）の環境場パラメータに有意な差がある。流れパターンで分類したトロピカルストームの強度に達するための環境場条件は以下のようにまとめられる。SLとGYはより高いtropical cyclone heat potential、CRはより弱い鉛直シア、EWはより湿潤な場、そしてPTCはより高い海面温度と先行のTCが強いことである。