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441.
Because the classification of propafenone and moricizine is not clear, we measured in 20 specifically equipped isolated rabbit hearts QRS duration, QT interval, action potential duration at 90% of repolarization (APD90), effective refractory period (ERP), conduction time (CT), and rise velocity (Rv) of the monophasic action potentials (AP) during exposure to moricizine and propafenone in comparison with procainamide. Propafenone and procainamide prolonged APD90 and JT. All drugs increased ERP. Propafenone demonstrated marked tonic sodium channel block. Onset of use-dependent kinetics (tau on), defined as change in Rv as fraction per beat at 300 ms cycle length (CL), were 0.047 +/- 0.004/beat for procainamide, 0.050 +/- 0.004/beat for propafenone, and 0.022 +/- 0.003/beat for miricizine. Recovery kinetics, defined as recovery of Rv after cessation of pacing, had a time constant of 5.3 +/- 0.7 s for procainamide, 6.3 +/- 0.8 s for propafenone, and 25.0 +/- 1.3 s for moricizine. Based on these data, moricizine must be classified as a Ic agent, whereas propafenone demonstrates pronounced tonic sodium channel block, in addition to its phasic block, which is similar to class Ia kinetics. 相似文献
442.
DY Graham J Abou-Sleiman HM el-Zimaity A Badr DP Graham HM Malaty 《Canadian Metallurgical Quarterly》1996,1(3):172-174
A 44-year-old male presented with a solitary cerebellopontine angle (CPA) metastasis from lung cancer. His initial symptoms were vertigo and hearing loss beginning 5 months after the diagnosis of the primary cancer. Two months later, right facial paresis developed. His neurological deterioration was rapid. Magnetic resonance (MR) imaging with enhancement disclosed the CPA tumor. The tumor was partially removed through the retroauricular retromastoid approach. Histological examination of the specimen revealed adenocarcinoma. The characteristic rapidly progressive symptoms and MR imaging with enhancement are the most sensitive and essential examinations for this lesion. 相似文献
443.
Fiber optic ultrasonic sensor using Raman-Nath light diffraction 总被引:1,自引:0,他引:1
Yunqiu Wu Shankar P.M. Lewin P.A. Koller D.P. 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1994,41(2):166-171
A novel fiber optic ultrasonic sensor using the principle of Raman-Nath light diffraction has been developed. The sensor does not perturb the acoustic field and exhibits a wideband frequency response. In addition to the remote sensing of the field, it is suitable for measurements of both continuous and pulsed ultrasonic waves. The experimental results obtained with the sensor were compared to those measured using a calibrated PVDF needle hydrophone, showing excellent agreement. The sensor's frequency response in the range from 3 to 15 MHz, typical of that used in medical ultrasound imaging, was determined using the time delay spectrometry (TDS) technique. It appears that the fiber optic sensor provides a useful alternative to the widely used PVDF ultrasonic probes in specific applications where any perturbation between acoustic field and sensor is undesirable. Also, since the active element diameter of the sensor can be made comparable to the core diameter of an optical fiber, the fiber optic sensor minimizes the spatial averaging effects and offers significant improvement in comparison with the present state-of-the-art hydrophones which have a minimum diameter on the order of 300 μm 相似文献
444.
BS Margolin PW Garrett-Engele JN Stevens DY Fritz C Garrett-Engele RL Metzenberg EU Selker 《Canadian Metallurgical Quarterly》1998,149(4):1787-1797
In an analysis of 22 of the roughly 100 dispersed 5S rRNA genes in Neurospora crassa, a methylated 5S rRNA pseudogene, Psi63, was identified. We characterized the Psi63 region to better understand the control and function of DNA methylation. The 120-bp 5S rRNA-like region of Psi63 is interrupted by a 1.9-kb insertion that has characteristics of sequences that have been modified by repeat-induced point mutation (RIP). We found sequences related to this insertion in wild-type strains of N. crassa and other Neurospora species. Most showed evidence of RIP; but one, isolated from the N. crassa host of Psi63, showed no evidence of RIP. A deletion from near the center of this sequence apparently rendered it incapable of participating in RIP with the related full-length copies. The Psi63 insertion and the related sequences have features of transposons and are related to the Fot1 class of fungal transposable elements. Apparently Psi63 was generated by insertion of a previously unrecognized Neurospora transposable element into a 5S rRNA gene, followed by RIP. We name the resulting inactivated Neurospora transposon PuntRIP1 and the related sequence showing no evidence of RIP, but harboring a deletion that presumably rendered it defective for transposition, dPunt. 相似文献
445.
The present paper critically appraises two recent overviews of the literature on rectal cancer and quality of life (QL). These reviews focus on the Anglo-American literature, largely neglect research from other countries, and provide little stimulus regarding future research directions. As an alternative perspective we propose the concept of problem-solving oriented QL research. The major theme is that the QL concept must be integrated into the clinical arena. To begin with, QL researchers must make themselves understandable. We outline several ways in which this can be achieved: (a) placing QL in a broader concept together with outcomes that are more familiar to clinicians; (b) depicting individual patients in the form of QL profiles; (c) clarifying the psychosocial/clinical correlates of particular QL scores of interest; and (d) conducting studies with a definitive practical goal in mind and integrating practitioners and patients into the study group. We illustrate the feasibility of such a research program by performance data from our Marburg-Biedenkopf field trial. Pursuing an ambitious research strategy that integrates experimental and applied research, the QL movement will have the chance to show that it is not merely l'art pour l'art, but indeed is beneficial to society. 相似文献
446.
447.
M Beran E Estey SM O'Brien FJ Giles CA Koller S Kornblau M Keating HM Kantarjian 《Canadian Metallurgical Quarterly》1998,31(5-6):521-531
The activity of topotecan was evaluated in patients with myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML). Sixty patients with a diagnosis of MDS (n = 30) or CMML (n = 30) were treated. Their median age was 66 years, with 50 patients (83%) being over 60 years of age at time of study entry. Chromosomal abnormalities were present in 50% of patients and thrombocytopenia of less than 50 x 10(9)/L in 50%. Topotecan was administered as 2 mg/m2 by continuous infusion over 24 hours daily for five days (10 mg/m2 per course) every 4 to 6 weeks for two courses, then at maximum tolerated dose level (1-2 mg/m2 by continuous infusion over 24 hours daily for five days) once every 4-8 weeks for a maximum of 12 courses. Evaluation of outcome and of differences among subgroups was performed according to standard methods; the criteria for response were those used for acute leukemia. Nineteen patients (31%) achieved a complete response (CR). A CR was achieved in 11 of 30 patients with MDS (37%) and in eight of 30 with CMML (27%). A CR was achieved in 10 of 23 patients with previously untreated MDS (43%). Eight of 11 patients who presented with cytogenetic abnormalities (five of which involved chromosome 5 and/or 7 abnormalities) and achieved CR, were evaluated cytogenetically in CR: all were cytogenetically normal in CR. Characteristics associated with a higher CR rate were lack of previous chemotherapy, absence of ras oncogene mutations, and presence of less than 10% monocytes in either peripheral blood or bone marrow. In contrast, CR rates were similar by different agent groups, by different karyotype abnormalities, and by other pre-therapy peripheral blood counts. Non-myelosuppressive side effects were mucositis in 67% of patients (severe [grade 3-4] 23%), diarrhea in 38% (severe 17%), and nausea and vomiting in 28% (severe 5%). Febrile episodes during neutropenia occurred in 85% of patients and documented infections in 47 %. Mortality in the first four weeks was 20%. With a median follow-up duration of 31 months, the 12 month survival rate was 38%, median survival time 10.5 months, and median remission duration 7.5 months. In summary, topotecan has significant single-agent activity in MDS and CMML. Complete responses associated with topotecan therapy often involve the disappearance of abnormal, poor-prognosis karyotypes, which is particularly encouraging. Future strategies to optimize topotecan's role include combination regimens with topoisomerase II reactive agents, cytarabine, or hypomethylating agents (azacytidine and decitabine). 相似文献
448.
Synchronization of chaotic laser mode dynamics 总被引:1,自引:0,他引:1
449.
TH Lee K Shimazaki SL Yu MS Nam SJ Kim KK Lee DY Yu 《Canadian Metallurgical Quarterly》1997,28(5):367-369
Lactoferrin, which exhibits antibacterial activity to protect infants from infectious disease, is a major component of colostrum and milk. Lactoferrin was purified from the colostrum of Korean Native goat, and the cDNA from the mammary gland mRNA of the animal was cloned and sequenced. The nucleotide sequence of the lactoferrin gene of Korean Native goat was found to differ in 15 sites from that of the goat lactoferrin gene reported earlier. This difference in nucleotide sequence resulted in six amino acid substitutions: five in the N-lobe and one in the C-lobe. The antibacterial activity of Korean Native goat lactoferrin was found to be greater than that of Sannen goat lactoferrin. 相似文献
450.
K. Dorfmeister F. Koller St. Winkler 《e & i Elektrotechnik und Informationstechnik》1997,114(10):552-557
The matrix turbine features an arrangement of identical units of turbines and asynchronous generators. When installed in the stop log slot of a fill and discharge channel of a ship lock, power is generated both during fill and discharge operations. The locks of seven power plants at the Danube allow retrofit with marginal civil construction effort. 相似文献