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The projectile fragment separator provides a wide variety of short-lived RI-ions with less restrictions on their chemical property or lifetime limit. The beam energy and quality is, however, not adequate for low-energy beam experiments, in particular for trapping experiments. Recently, one has proposed to obtain a low-energy beam from an energetic RI-beam leaving a projectile fragment separator by using a large gas-catcher and an rf ion-guide system. In off-line and in on-line test experiments, the principle of the rf ion-guide was proven. An overall efficiency of 0.2% for 70 MeV/u 8 Li from the RIKEN projectile fragment separator (RIPS) was obtained so far.

This paper describes a case of disseminated cryptococcosis presenting with jejunal perforation. A 46-year-old man, who had an episode of liver cirrhosis and orally took 30mg/day of prednisolone for nephrotic syndrome, was admitted to the hospital because of postprandial severe upper abdominal pain. He was diagnosed as having an intestinal perforation and an emergency operation was carried out. A whole-circumference ulcer with irregular margin was found at the jujunum about 90cm from the ligament of Treitz. The lesion was resected, nevertheless he died of multiple organ failure on the 35th postoperative day. Histological examination of the specimen indicated transmural epitheloid granuloma with diffuse infiltration of cryptococcus. Autopsy revealed cryptococcal infection in multiple organs. It was finally diagnosed as disseminated cryptococcosis. Judging from the shape of circular ulcer and cell-mediated immunosuppressive condition, it was suggested that infectious mechanism would depend upon lymphatic and hematogenous spreading pattern similar to tuberculosis.

食道裂孔を介し右後縦隔内へ進展した縦隔内膵仮性嚢胞の1例を経験した. 症例は42歳の男性. 20年来の飲酒歴, 24歳時に急性膵炎の手術既往あり. 以来, 慢性再燃性膵炎の治療歴を有する. 平成6年3月腹痛を主訴に前医を受診し, 膵炎の急性増悪として入院加療中であった. 6月になり, 胸部X線にて縦隔腫瘍と胸水が認められ, 胸部computed tomographyにて後縦隔に嚢胞性病変を, magneticresonance imagingにて横隔膜直上から上縦隔におよぶ巨大な嚢胞を認めたことから当院紹介され転院となった. 膵炎の保存的治療により縦隔嚢胞は消裾したが, 腹部CTでは膵被膜と胃後壁の間に嚢胞の遺残を認め, またendoscopic retrograde pancreatographyにて主膵管と交通する膵仮性嚢胞および膵・縦隔瘻孔を確認したことから膵体尾部切除術を施行した. 術後順調に経過し, 退院後1年4カ月の現在, 再発の徴候はみられない.

Although the projectile fragment separator (RIPS) at the RIKEN accelerator facility (RARF) provides wide variety of energetic radioactive beams, it is not adequate for low energy beam experiments such as precision spectroscopy of trapped ions. Aiming for an efficient deceleration and cooling of energetic radioactive ions, the development of an rf ion guide system which comprises a large He gas cell and an rf funnel structure in the cell is under progress. A proof of the principle (pop) machine has been successfully tested on-line for collection of 70-MeV/u 8Li ions. A compact gas cell of 70 cm in length and 10 cm in diameter with a He gas pressure of 30 Torr was placed after a variable wedge shaped energy degrader. The ions were stopped in the gas and were transported by a superposition of dc and rf electric field toward a small exit hole. The overall efficiency was 10−4 which can be separated into a gas stopping efficiency of 0.43% and an ion-guide efficiency of 2.4%. The former is limited by the volume ...