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排序方式: 共有1464条查询结果,搜索用时 31 毫秒
931.
K Kaji S Kaneko E Matsushita K Kobayashi O Matsui Y Nakanuma 《Canadian Metallurgical Quarterly》1998,93(12):2568-2572
Focal nodular hyperplasia (FNH) of the liver is a lesion characterized by a well circumscribed region of hyperplastic liver tissue with stellate fibrosis. The pathogenesis of the lesion is unknown but various authors consider that FNH may be a response to a preexisting vascular abnormality. We experienced a case of progressive multiple FNH, in which the hemodynamic change as shown by imaging modalities, may support this hypothesis. The patient, a 38-yr-old woman, was found by chance to have multiple portal venous shunts and multiple FNH in both lobes of her liver. Because of their benign characteristics, we followed the nodules periodically without any special treatment. After about 4 yr, the nodules increased both in size and number. In addition, digital subtraction angiography showed that the diameter of the artery had become larger. The hemodynamic change revealed by imaging studies in this case supports the hypothesis that one of the pathogens of FNH is a secondary hepatocellular response to arterial hyperperfusion caused by some vascular malformations. 相似文献
932.
We propose a technique for achieving mode-locking at very high repetition rates more than terahertz with high output power using a distributed-Bragg-reflector (DBR) laser, including an intracavity saturable absorber. This method is based on harmonic passive mode-locking at high gain levels and the selectivity of harmonic numbers related to the spectrum-filtering property of the intracavity Bragg reflector. Transform-limited pulses at repetition rates from 500 GHz to 1.54 THz were generated with an output power exceeding 15 mW. We studied stability of harmonic pulses by using conventional self-consistent mode-locking equations. We also discuss the effect of the spectrum-filtering properties of the intracavity Bragg reflector to the characteristics of mode-locked pulses 相似文献
933.
A Nonomura H Minato K Shimizu M Kadoya O Matsui 《Canadian Metallurgical Quarterly》1997,193(7):519-25; discussion 526
Inflammatory pseudotumor (IPT) of the liver is rare. We present a case of hepatic IPT mimicking cholangiocarcinoma in which the tumor was located at the left porta hepatis. The patient was a 64-year-old man in whom abnormal liver function test results had been noted incidentally during an annual health checkup in 1993: the patient declined to go to the hospital for further examination. At the annual health checkup the following year, abnormal liver function test results were noticed again, and this time he did go to a hospital, where a hepatic mass was found. Laboratory test results were unremarkable. Based on the location of the lesion and the findings of a variety of imaging modalities, such as ultrasound and computed tomography examination, the lesion was preoperatively diagnosed as hilar cholangiocarcinoma and was surgically resected. Pathologic examination of the resected lesion, however, revealed that it was not a true tumor but an inflammatory pseudotumor with marked destructive and sclerosing cholangitis mimicking primary sclerosing cholangitis (PSC) and obliterative phlebitis. Since the location and features of the tumor in the present case are very pertinent to the relationship between IPT and PSC, we describe its clinical and histologic features and discuss the findings in relation to PSC in the context of our literature review. 相似文献
934.
Generation of wavelength tunable gain-switched pulses from FP MQW lasers with external injection seeding 总被引:3,自引:0,他引:3
Y. Matsui S. Kutsuzawa S. Arahira Y. Ogawa 《Photonics Technology Letters, IEEE》1997,9(8):1087-1089
High-repetition rate (20 GHz), wavelength tunable (40 nm) optical pulses have been generated by gain switching of 1.55-/spl mu/m Fabry-Perot (FP) multiple-quantum-well (MQW) lasers using continuous-wave (CW) light injection for longitudinal mode selection. After fiber compression, a pulse duration shorter than 5.8 ps was obtained over the entire wavelength tuning range. The pulsewidth, chirping characteristics and side-mode suppression ratio were investigated as functions of the seeding power and wavelength. In addition, we report on the observation of chaos and period doubling for a gain-switched laser without injection seeding, and show that irregular behavior can be suppressed by injection seeding of the laser. 相似文献
935.
I Ohizumi S Tsunoda K Taniguchi H Saito K Esaki K Koizumi H Makimoto Y Wakai J Matsui Y Tsutsumi S Nakagawa N Utoguchi Y Ohsugi T Mayumi 《Canadian Metallurgical Quarterly》1998,77(4):561-566
An industrial erythromycin production strain of Saccharopolyspora erythraea spp. was used to demonstrate that careful genetic engineering can significantly improve productivity. The chromosomally integrated Vitreoscilla hemoglobin gene (vhb) was shown to enhance the final titer of erythromycin by some 70% compared to the original S. erythraea spp. Overall, specific erythromycin yields were about 2.5 g of erythromycin/g of total protein for S. erythraea::vhb but <1 for the S. erythraea spp. The maximum rates of biosynthesis were 57.5 mg of erythromycin/(L/h) and 24.3 mg/(L/h) for the recombinant strain S. erythraea::vhb and S. erythraea spp., respectively. Overall space-time yield was 100% higher for the S. erythraea::vhb fermentation (1.1 g of erythromycin/(L/day)) than for the S. erythraea spp. fermentation (0. 56 g of erythromycin/(L/day)). The genetic stability of the recombinant strain was high, and no selective pressure was needed throughout the cultivations. Expression of functional Vitreoscilla hemoglobin throughout the cultivations was verified by CO difference spectrum assays. 相似文献
936.
Angiotensin II interferes with leukemia inhibitory factor-induced STAT3 activation in cardiac myocytes 总被引:1,自引:0,他引:1
E Tone K Kunisada Y Fujio H Matsui S Negoro H Oh T Kishimoto K Yamauchi-Takihara 《Canadian Metallurgical Quarterly》1998,253(1):147-150
BACKGROUND: The 24-hour observation critical pathway for trauma is a clinical tool developed to expedite health care delivery to minimally injured patients. The use of patient care, BS, guidelines and physician-approved standing orders was implemented in a Level I trauma center. METHODS: A retrospective chart review was performed of 122 patients admitted via the emergency department between December 1, 1993, and May 31, 1994. All patients were evaluated in the emergency department by emergency medicine and trauma physicians and deemed appropriate for 24-hour observation. The information collected included patient demographics, hospital charges, injuries, length of stay, diagnostic tests, consultations, and variances from the critical pathway. RESULTS: During the 6-month study period, there were 600 trauma admissions. Of those admissions, 122 patients (20%) were evaluated in the emergency department and deemed appropriate for enrollment in the 24-hour observation pathway. The charts of these patients were reviewed. Fourteen admissions were determined inappropriate for the critical pathway because of the severity of injuries or discharge against medical advice. One hundred eight charts were evaluated further. Eighty-nine patients (80%) completed the critical pathway with a length of stay of 24 hours. CONCLUSION: The 24-hour observation critical pathway was designed and used appropriately as exemplified by an overall 80% completion rate. The critical pathway offers a mechanism to streamline care of the minimally injured trauma patient. It also serves as a quality-improvement tool for increasing efficiency, decreasing utilization of resources, and decreasing length of stay. 相似文献
937.
Akihiro Hoshino Masayuki Morimoto Nobuyuki Matsui 《Electrical Engineering in Japan》2005,153(2):52-60
This paper presents a method to estimate the output voltage of a high‐speed, surface permanent magnet generator with large air gap length at design stage. The output voltage is estimated by the induced electromotive force and the synchronous inductance obtained from the analytical results of the flux linkage using FEM. Also, a method to classify the synchronous inductance per causative factor is proposed. The air gap leakage inductance is not negligible in a large‐air‐gap machine like this generator. The validity of the proposed method has been proved by the measured values of a generator designed by this method, and the measured values also show that the output voltage of the generator is within the permissible range. The method proposed in this paper will be an effective tool to design a high‐speed, surface permanent magnet generator with large air gap length. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(2): 52–60, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20228 相似文献
938.
Kainate is a potent agonist of an excitatory amino acid receptor subtype in the central nervous system, and causes neuronal death in several regions of the brain. Neurons are preferentially killed in the hippocampus, especially in the CA1 region, by systemic administration of kainate. It is speculated that functional alterations occur in the neurons preceding death. We examined the effect of FK506 on kainate-induced neuronal death and functional alterations in the rat hippocampal CA1 region. FK506 had no effect on electrographic and behavioral seizure activities induced by kainate; however, it prevented neuronal death measured seven days after administration. Although neither death nor morphological alterations of neurons were observed in the CA1 region 24 h after administration, the neurons exhibited decreased excitatory postsynaptic potentials and enhanced long-term potentiation. This functional alteration was not detected in the rats administered FK506 prior to kainate. Taken together, these observations indicate that functional alteration precedes neuronal death in rats systemically administered kainate and that FK506 prevents both. It is suggested that FK506 exerts its neuroprotective effect not by attenuating electrographic and behavioral seizure activities, but by protecting neurons from kainate-induced functional disorders. 相似文献
939.
Yeast SRO7 was identified as a multicopy suppressor of a defect in Rho3p, a small GTPase that maintains cell polarity. Sro7p and Sro77p, a homologue of Sro7p, possess domains homologous to the protein that are encoded by the Drosophila tumor suppressor gene lethal (2) giant larvae [l(2)gl]. sro7Delta sro77Delta mutants showed a partial defect of organization of the polarized actin cytoskeleton and a cold-sensitive growth phenotype. A human counterpart of l(2)gl could suppress the sro7Delta sro77Delta defect. Similar to the l(2)gl protein, Sro7p formed a complex with Myo1p, a type II myosin. These results indicate that Sro7p and Sro77p are the yeast counterparts of the l(2)gl protein. Our genetic analysis revealed that deletion of SRO7 and SRO77 showed reciprocal suppression with deletion of MYO1 (i.e., the sro7Delta sro77Delta defect was suppressed by myo1Delta and vice versa). In addition, SRO7 showed genetic interactions with MYO2, encoding an essential type V myosin: Overexpression of SRO7 suppressed a defect in MYO2 and, conversely, overexpression of MYO2 suppressed the cold-sensitive phenotype of sro7Delta sro77Delta mutants. These results indicate that Sro7 function is closely related to both Myo1p and Myo2p. We propose a model in which Sro7 function is involved in the targeting of the myosin proteins to their intrinsic pathways. 相似文献
940.
Hideo Matsui Akira Okada Taketoshi Kuroda Yasuhiro Seguchi Tetsuro Kawahara Masakuni Yoshihara 《Journal of Materials Science》2007,42(11):3964-3968
Hafnium-organic moiety hybrid copolymers were prepared by reacting hafnium n-butoxide with organic diols. ESR spectral examinations of copolymers and ab-initio calculations of copolymer models suggest that an electron transfer from organic group to hafnium atom takes place. 相似文献