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41.
K Nakahara 《Canadian Metallurgical Quarterly》1989,9(5):429-433
Impact of surgery on the result of mediastinal tumors is variable: In benign tumors such as teratoma, congenital cyst, intrathoracic struma and neurogenic tumor, a complete resection causes a good result. Simultaneous thoracotomy and laminectomy should be performed in the Dumbbell type of neurogenic tumor. Since complete resection of the invasive thymoma promises a good prognosis, excision of all the tumor and invading tissues followed by radiation therapy is recommended in the treatment of thymoma. In pure seminoma resection and radiation therapy is the treatment of choice, while in non-seminomatous germ cell tumor, aggressive chemo- and radiation therapy should be performed, until tumor markers such as AFP and HCG become negative. The operation is to be followed afterwards. A mass screening test for neuroblastoma in infant facilitates an early detection of this disease and promises a good result by chemotherapy, radiation therapy, and surgery. There is still a possibility that the result of treatment of the malignant mediastinal tumors would be improved by exact diagnosis and intensive treatment. 相似文献
42.
K Araki I Nakahara W Taki N Sakai K Irie F Isaka H Ohwaki H Kikuchi 《Canadian Metallurgical Quarterly》1997,25(8):733-738
Cortical venous drainage has been described as one of the major risk factors for dural arteriovenous fistula, which may induce venous hypertension leading to venous ischemia or intracerebral hemorrhage. However, it is rather rare to observe cortical venous drainage manifesting in this way in the cavernous sinus region. We report a case of a 55-year-old gentleman with a right cavernous dural arteriovenous fistula, presenting with conjunctival chemosis, exophthalmus and ocular hypertension on the affected side. Magnetic resonance imaging showed a small intracerebral hemorrhage in the right frontal lobe. Cerebral angiography revealed a dural arteriovenous fistula in the right cavernous sinus draining into the right olfactory vein via the uncal vein, as well as into the superior and inferior ophthalmic veins. This unusual cortical venous reflux was thought to be consistent with the intracerebral hemorrhage found on the magnetic resonance imaging. The patient underwent transvenous embolization for the dural arteriovenous fistula using an inferior petrosal catheterization into the uncal vein was difficult, and the cortical venous reflux through the vein seemed to be slight. However, extravasation of the contrast material occurred in the right frontal lobe after obliteration of the ophthalmic veins during the procedure. The cause of the extravasation was suspected to be the same olfactory vein that had been involved in the previous intracerebral hemorrhage. The obliteration of the dural fistula was continued rapidly, and the fistula disappeared after the embolization. Neurologically, the patient had no noticeable troubles, except for a mild headache. The pretreatment symptoms were alleviated within several days, and the patient was discharged in a week. We emphasize the following points from this rare case in order to facilitate a safer procedure during transvenous embolization for cavernous dural arteriovenous fistula. It is important to obliterate the cortical venous drainage as early as possible, even if the reflux is small or the catheterization is difficult. Repeated, careful sinography is useful for the evaluation of the drainage pattern at certain stages during the transvenous embolization procedure. 相似文献
43.
K Nakahara H Saito T Saito M Ito N Ohta N Sakai N Tezuka M Hiroi H Watanabe 《Canadian Metallurgical Quarterly》1997,67(2):302-308
Vagal primary afferent neurons have their cell bodies located in the nodose (inferior) and jugular (superior) vagal ganglia and send terminals into the nucleus tractus solitarii (NTS) which lies in the dorsomedial medulla. The presence of glutamate (Glu)-containing neurons in the rat nodose ganglion was investigated using immunohistochemistry. Glu-immunoreactivity on nodose sections was found in neuronal perikarya and nerve fibers, but not in non-neuronal elements such as Schwann cells and satellite cells. Both immunoreactive and non-immunoreactive ganglion cells were observed. The immunoreactive ganglion cells amounted to about 60% of the nodose population. No specific intraganglionic localization was observed for the non-immunoreactive cells. Immunoreactive perikarya were slightly smaller than the non-immunoreactive ones, but no relationship was found between size and staining intensities of immunoreactive neurons. The present data indicate that immunodetectable Glu is present in a large population of vagal afferent neurons. They therefore add to a growing body of evidence suggesting that Glu may be the main neurotransmitter released by vagal afferent terminals within the nucleus tractus solitarii. 相似文献
44.
This historical review of the progress of innovation in diamond research is discussed comparing it with the history of other
materials. The innovation steps in current diamond technology are shaped by the fact that diamond is a functional material.
This series of innovations was mainly brought about by the discovery of CVD methods of synthesizing diamond from the gas phase.
Many kinds of expected applications have been proposed. Success in demonstrating diamond electronic devices has been achieved,
and atomic scale observations on diamond growth are reported. Thus, even atomic scale control in synthesizing diamond looks
quite realistic in the near future. Although such new data enhance the applications of diamond, most industrial applications
of diamond still rely on its hardness. Innovation with diamond will be accelerated when a product using diamond as a functional
material is used widely.
Received: 2 January 1997 / Accepted: 27 March 1997 相似文献
45.
Disposition of 3,4-methylenedioxymethamphetamine (MDMA) in hair roots was studied using rats and the hair root samples were evaluated to prove acute MDMA poisoning. The back hair of male pigmented hairy rats (n = 6) was shaved and 5 d later the animals were intraperitoneally administered with acute poisonous doses (20, 40, 60, 80 and 100 mg/kg) of MDMA. Roots of the hairs were then plucked out with a hair nipper 5 min and, 0.5, 1, 2, 6 and 24 h after injection. The hair root samples were, directly or after being washed with detergent, extracted with methanol-5 N HCl (20:1) under ultrasonication in ice-cold water for 4 h. After filtration and evaporation, the residue was derivatized with pentafluoropropionic anhydride and analyzed by GC/MS. From all samples including the 5 min sample, MDMA was detected at high concentrations (up to 156 ng/mg) accompanied by 3,4-methylenedioxyamphetamine (MDA). Some of the animals died within 2 h after administration, but in the surviving rats the MDMA concentrations in the hair roots increased up to 6 h and then slowly decreased until 24 h. The remaining MDMA after washing apparently increased from 13-31% at 0.5 h to 51-83% at 24 h in the surviving rats. These facts show that most of drugs in the hair roots are not yet immobilized in the early stage and are thereafter gradually incorporated into the hair shaft. Increase of the MDMA concentration stopped soon after death of the animal, probably due to the cessation of hair growth. Although the ratios of MDA/MDMA steadily increased over time, those after death plateaued, probably due to the cessation of metabolism after death. It was clearly shown that MDMA is more quickly incorporated into and more firmly retained in hair than methamphetamine (MA) by comparing their disposition in hair roots. 相似文献
46.
Nakahara K. Kondow M. Kitatani T. Larson M.C. Uomi K. 《Photonics Technology Letters, IEEE》1998,10(4):487-488
A 1.3-μm continuous wave lasing operation is demonstrated, for the first time, in a GaInNAs quantum-well laser at room temperature. This lasing performance is achieved by increasing the nitrogen content (up to 1%) in GaInNAs quantum layer. It is thus confirmed that this type of laser is suitable for use as a light source for optical fiber communications 相似文献
47.
As a two-dimensional parallel digital processing device, we describe a switchable-logic photonic switch array that monolithically integrates metal-semiconductor-metal (MSM) photodetectors, field-effect-transistor (FET) amplifiers, and multiple-quantum-well (MQW) modulators. All-optical positive and negative logic operations are demonstrated with controllable thresholds and a 3-dB bandwidth of 300 MHz. In this device, the logic mode is switched by changing the bias voltage polarity of the MSM photodetector 相似文献
48.
K Uozumi N Ohno K Nakahara T Makino A Utsunomiya S Hanada T Arima 《Canadian Metallurgical Quarterly》1997,77(2):204-210
Differences in the responses of an elderly biracial group of cognitively normal subjects to a 15-item short version of the Boston Naming Test developed for the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) were examined. The subjects consisted of 103 Whites and 136 African Americans who were 70 years of age and older and living in a five-county urban and rural area of North Carolina. They were drawn from the Duke University site of the Established Populations for Epidemiologic Studies of the Elderly (EPESE). All were cognitively normal. With gender, years of education, and age controlled, White subjects performed significantly better than did African American subjects. The items in this test were selected to represent words with a high, medium, and low frequency of occurrence in English. They did not, however, show the expected gradation for either racial group. Medium and low frequency items were of comparable difficulty for the two races. Hierarchical ordering of difficulty would be improved with minor rearrangement of items. 相似文献
49.
Nakahara K. Tsuchiya T. Kitatani T. Shinoda K. Kikawa T. Hamano F. Fujisaki S. Taniguchi T. Nomoto E. Sawada M. Yuasa T. 《Lightwave Technology, Journal of》2004,22(1):159-165
Direct modulation at 12.5 Gb/s of 1.3-/spl mu/m InGaAlAs distributed feedback (DFB) ridge waveguide (RWG) lasers with low-resistance notch-free gratings running up to 115/spl deg/C is experimentally demonstrated. It was achieved by the combination of the high differential gain of an InGaAlAs MQW active layer, high characteristic temperature of RWG structure, and low-resistance notch-free grating. Moreover, successful transmission of 10-Gb/s modulated signals over 30-km standard single-mode fiber was achieved with the laser running at up to 115/spl deg/C. These results confirm the suitability of this type of laser for use as the cost-effective light source in 12.5-Gb/s and 10-Gb/s datacom applications. 相似文献
50.