The relationship between mechanical properties and oxidation of ALON-based composite ceramics at high temperature was investigated. The flexural strength of ALON-based composite ceramics at 600-800 ...deg C decreased by 10-30% compared to the strength measured at room temperature. The flexural strength at 1000 deg C was about one half of the room temperature strength; however, the strength at > 1000 deg C increased again. Investigation based on x-ray diffractometry (XRD) and thermogravimetry-differential thermal analysis (TG-DTA) clarified that in the ALON-based composite ceramics, formation of gamma '-ALON and B sub 2 O sub 3 by oxidation of gamma -ALON, BN phases in the ceramics occurred by heating up to 800 deg C in air, then at 1000 deg C alpha -Al sub 2 O sub 3 formed by gamma '-ALON and finally 9Al sub 2 O sub 3 2B sub 2 O sub 3 formed on the surface of the ceramics containing BN contents > 10 vol.%. Decreasing of flexural strength at elevated temperature was caused by oxidation of gamma -ALON and BN phases.
Previously we demonstrated prolongation of islet allograft survival in rat by administration of FK506 to the recipients. The purpose of the present study was to determine whether specific immune ...unresponsiveness had been induced and to determine the effects of low temperature culture of donor islets as well as the transplant site on the induction of immune unresponsiveness. At 90 days after transplantation, normoglycemic recipients bearing functional intrahepatic grafts were made diabetic again with streptozotocin (STZ) and donor specific or third party islets were transplanted either into the liver or beneath the kidney capsule. When fresh islets were used as donors in initial transplantation in conjunction with FK506, intrahepatic re-transplants of fresh islets from the donor-specific strain in the absence of FK506 maintained normoglycemia for more than 60 days, while third party transplants (n = 3) were rejected within 1 wk. In contrast to intrahepatic regrafts, all the renal subcapsular regrafts from the donor-specific strain (n = 3) were rejected with mean survival time of 12.7 +/- 6.4 days. When cultured (24 degrees C, 7 days) islets were used for initial transplantation in conjunction with FK506, re-transplants of fresh or cultured islets from the donor specific strain beneath the kidney capsule maintained normoglycemic in 3 out of 6 or all (n = 4) of the recipients, respectively. Cultured third party regrafts beneath the kidney capsule (n = 2) were rejected at 9 days.
Critical parameters of low-k films were defined to keep capacitance benefit and TDDB reliability in the scaling BEOL module, according to various analyses. In order to meet the criteria of high ...carbon content, low porosity with small pores, and high adhesion strength with less adhesion layer, precursor and process were designed for the SiOCH with k~2.5. The benefits in integration and reliability from the newly developed robust low-k film were verified through the trench-first integration of 80 nm-pitch BEOL modules.
Prevention of perioperative hypothermia is one of the most essential factor for neonatal anesthesia. Recently the forced-air warming system has been considered the most effective method in preventing ...perioperative hypothermia in adults, in children, and in infants during maxillofacial operations. However, its use for abdominal or thoracic surgery in neonates has not been examined. In the present study, we studied the effects of the forced-air warmer with a ring-shape cover, and compared this method with the conventional method retrospectively.
Sixteen neonates, 13 for abdominal and 3 for thoracic surgery were anesthetized with oxygen-air (nitrous oxide) sevoflurane (isoflurane or enflurane) in combination with/without fentanyl. They were divided into two groups; one for forced-air warming (F-group), and another for conventional methods (C-group). The patients' mean age, height and weight, the duration of anesthesia, infusion rate (ml.kg-1.hr-1), and urine output did not differ each other. Patients in F-group were placed in the center of the ring-shape cover and received heated air from their surroundings. We did not use any other warming equipment or means except for an artificial nose and a warming mattress. "Medium" heated air (38 degrees C) or unheated, room temperature air were used when necessary. The operating room temperature was kept around 25 degrees C. Patients in the C-group were placed on a warming mattress and under an infrared radiant heater with the room temperature of 30 degrees C. Their extremities were covered with aluminum-foil. Rectal, deep forehead, and deep sole temperatures were monitored throughout anesthesia.
In F-group, temperatures were well maintained, while C-group failed to maintain. In F-group, the mean value of base excess at the beginning of the operation was -1.8 mM, but it was restored to normal level without administration of sodium bicarbonate. No complications were found. Thus, compared to conventional methods, the forced-air warming system with a ring-shaped cover is an efficient method for body temperature management in neonatal anesthesia.
Although urinary trypsin inhibitor (ulinastatin, UTI) is excreted into urine, its physiological function has not been clarified well. Administration of UTI during surgical procedure was reported to ...protect renal function from surgical stress. This result suggests participation of UTI excretion in renal tubular function. In this study, the amount of urinary excretion of UTI and that of N-acetyl-beta-D-glucosaminidase (NAG) after cardiopulmonary bypass (CPB) were measured. The urinary UTI excretion increased after surgery and reached the maximum on the third postoperative day. NAG also increased gradually and was three times greater than control on the seventh postoperative day. There was a good correlation between NAG and UTI on the first postoperative day. It is suggested that UTI might correlate with the renal tubular function after CPB.
