The structure of the shower disk observed at Mt. Norikura

The structure of the EAS shower disk, the arrival time distribution of charged particles at the core of the small or middle size shower, is measured at Mt. Norikura in Japan. Four fast scintillation counters with an area of 0.25 sq m and a fast trigger system are added to the Mt. Norikura EAS array for the study

Fast scintillation counter system and performance

An experimental study of the fast scintillation counter (FS) system to observe a shower disk structure at Mt. Norikura is described, especially the system performance and a pulse wave-form by a single charge particles. The photomultiplier tube (PT) pulse appears at the leading edge of the main pulse. To remove this PT-pulse from the main pulse, the frame of the scintillator vessel was changed. The fast triggering system was made to decrease the dead time which came from the use of the function of the self triggering of the storage oscilloscope (OSC). To provide a new field on the multi-parameter study of the cosmic ray showers, the system response of the FS system also improved as a result of many considerations

Photobiologic and Photoimmunologic Characteristics of XPA Gene-Deficient Mice

Xeroderma pigmentosum group A (XPA) gene-deficient mice cannot repair UV-induced DNA damage and easily develop skin cancers by UV irradiation. Just like human XP patients, homozygous (–/–) mice developed stronger longer-lasting acute inflammation than did wild-type mice after a single irradiation with UVB. Moreover, the model mice showed more severe UV-induced damage of keratinocytes and Langerhans cells than did the control mice. UVB-induced local and systemic immunosuppression was greatly enhanced in the (–/–) mice. Treatment with indomethacin, an inhibitor of prostaglandin (PG) synthesis, inhibited UV-induced inflammation and abrogated immunosuppression. In XPA-deficient mice, the amount of PGE2 and the expression level of COX-2 mRNA greatly increased after UVB irradiation compared with wild-type mice. These results suggest that the excess DNA photoproducts remaining in XPA-deficient cells after UV radiation induce COX-2 expression and subsequently produce a high amount of PGE2, which causes the enhancement of inflammation and immunosuppression. In XPA-deficient mice, the natural killer cell activity significantly decreased after repeated exposures to UVB. Our experimental data indicate that cancer development in XP patients involves not only mutagenesis due to the defect in DNA repair, but also the enhanced UV-immunosuppression and intensified impairment of natural killer function

Smad6/Smurf1 overexpression in cartilage delays chondrocyte hypertrophy and causes dwarfism with osteopenia

Biochemical experiments have shown that Smad6 and Smad ubiquitin regulatory factor 1 (Smurf1) block the signal transduction of bone morphogenetic proteins (BMPs). However, their in vivo functions are largely unknown. Here, we generated transgenic mice overexpressing Smad6 in chondrocytes. Smad6 transgenic mice showed postnatal dwarfism with osteopenia and inhibition of Smad1/5/8 phosphorylation in chondrocytes. Endochondral ossification during development in these mice was associated with almost normal chondrocyte proliferation, significantly delayed chondrocyte hypertrophy, and thin trabecular bone. The reduced population of hypertrophic chondrocytes after birth seemed to be related to impaired bone growth and formation. Organ culture of cartilage rudiments showed that chondrocyte hypertrophy induced by BMP2 was inhibited in cartilage prepared from Smad6 transgenic mice. We then generated transgenic mice overexpressing Smurf1 in chondrocytes. Abnormalities were undetectable in Smurf1 transgenic mice. Mating Smad6 and Smurf1 transgenic mice produced double-transgenic pups with more delayed endochondral ossification than Smad6 transgenic mice. These results provided evidence that Smurf1 supports Smad6 function in vivo

集積回路の低電圧化に伴うアナログ入力バッファの特性検討 : 相補型2入力バッファ回路の提案

Complementary-type analog input buffer is proposed for low-voltage operation in CMOS integratedcircuits. It consists of a conventional source-follower and an inverter-type input buffer. Small-signal analysis andcircuit simulation show that our new complementary-type analog input buffer has a comparable bandwidth andtwice gain compared to source-follower. It is suitable for interface circuits for differential signal and is effective forcommon-mode noise reduction

Can POSSUM, a Scoring System for Perioperative Surgical Risk, Predict Postoperative Clinical Course ?

POSSUM, a Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity, is a scoring system which assesses perioperative surgical risks (Copeland GP et al.: Br J Surg, 1991, Vol 78, 356-360). The POSSUM scoring system consists of two categories of assessment to assess the risk of surgery. A 12-factor (age, cardiac status, pulse rate, systolic blood pressure, respiratory status, Glasgow Coma Score, serum concentration of urea, potassium and sodium, hemoglobin concentration, white cell count and findings on electrocardiography) and 4-grade physiological score (PS) were developed. This was combined with a 6-factor (type of surgical procedure, number of procedures, blood loss, peritoneal soiling, presence of malignancy and mode of surgery) and 4-grade operative severity score (OSS). The present paper attempts to validate it retrospectively. Postoperative hospitalization period and duration of antibiotics administration were both significantly correlated with OSS, but not with PS. These results suggest that the POSSUM scoring system is useful for predicting the postoperative clinical course.</p