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41.
In order to extend the expressive power of deductive databases, a formula that can have existential quantifiers in prenex normal form in a restricted way is defined as an extended rule. With the extended rule, we can easily define a virtual view that requires a division operation of relational algebra to evaluate. The paper addresses a recursive query evaluation where at least one formula in a recursive rule set is of an extended rule. We investigate transformable recursions as well as four cases of non-transformable recursions of transitive-closure-like and linear type. The work reveals that occurrence of an existentially quantified variable in the extended recursive body predicate might dramatically limit the level of recursive search. In particular, the number of iterations to answer extended queries can be determined, independently of database contents 相似文献
42.
OBJECTIVE: The purpose of our study was to evaluate the effectiveness of MR imaging for showing the intrinsic anatomy of a peripheral nerve. Cadaver wrist specimens that included the median nerve were imaged with MR imaging at 3 T, then sectioned, stained, and inspected grossly and microscopically. The size, shape, and signal intensity of the sheath and axonal structures in the median nerve were identified in MR images by comparison with anatomic sections. CONCLUSION: This study suggests that MR imaging with sufficiently high-resolution techniques shows the internal structure of peripheral nerves. These results suggest that MR imaging may be a means to distinguish neuritis, tumor, degeneration, or fatty proliferation in a peripheral nerve and to evaluate the nerve before microsurgical anastomosis. 相似文献
43.
Wen-Jen Ho Wen-Thong Chang 《Electronics letters》1998,34(5):433-434
A multi-layer multigrid algorithm for curve fitting in the wavelet domain is presented. This algorithm is achieved by applying a wavelet transform to each grid of the conventional multigrid structure. Using a wavelet transform, the convergent rate in each grid is improved and the total system can converge more quickly 相似文献
44.
Yo-Chuol Ho Ki-Hong Kim Floyd B.A. Wann C. Yuan Taur Lagnado I. O K.K. 《Solid-State Circuits, IEEE Journal of》1998,33(12):2066-2073
Four- and 13-GHz tuned amplifiers have been implemented in a partially scaled 0.1-1 μm CMOS technology on bulk, silicon-on-insulator (SOI), and silicon-on-sapphire (SOS) substrates. The 4-GHz bulk, SOI, and SOS amplifiers exhibit forward gains of 14, 11, and 12.5 dB and Fmin's of 4.5 (bulk) and 3.5 db (SOS). The 13-GHz SOS and SOI amplifiers exhibit gains of 15 and 5.3 dB and Funn's of 4.9 and 7.8 dB. The 4-GHz bulk amplifier has the highest resonant frequency among reported bulk CMOS amplifiers, while the 13-GHz SOS and SOI amplifiers are the first in a CMOS technology to have tuned frequencies greater than 10 GHz. These and other measurement results suggest that it may be possible to implement 20-GHz tuned amplifiers in a fully scaled 0.1-1 μm CMOS process 相似文献
45.
Eight-channel bidirectional WDM add/drop multiplexer 总被引:2,自引:0,他引:2
Keang-Po Ho Shien-Kuei Liaw 《Electronics letters》1998,34(10):947-948
The authors propose and demonstrate an eight-channel reconfigurable bidirectional wavelength division multiplexed (WDM) add-drop multiplexer in which all channels can be added/dropped independently in either direction. The performance of the bidirectional WDM add/drop multiplexer is experimentally studied for a data rate of 10 Gbit/s per channel, providing an overall capacity of 80 Gbit/s. It is found that the performance of the add/drop multiplexer is not degraded by a backward propagating signal 相似文献
46.
47.
AIM: To examine the association of Epstein-Barr virus (EBV) with carcinoma of the ear. METHODS: Five non-keratinising squamous cell carcinomas and two undifferentiated carcinomas of the ear were examined. In situ hybridisation was used to localised EBV-encoded RNAs (EBER). Immunohistochemical methods to detect LMP-1 and EBNA2 were performed in the EBER positive cases. RESULTS: Two cases were EBER positive, including one non-keratinising and one undifferentiated carcinoma. Both showed identical morphology to those arising from the nasopharynx, with abundant lymphoid stroma. They were both negative for LMP-1 and EBNA2. CONCLUSIONS: EBV associated carcinoma with the morphology of lymphoepithelioma can also arise from the middle ear. 相似文献
48.
The effect of Pseudomonas aeruginosa infection on clinical parameters in steady-state bronchiectasis
PL Ho KN Chan MS Ip WK Lam CS Ho KY Yuen KW Tsang 《Canadian Metallurgical Quarterly》1998,114(6):1594-1598
STUDY OBJECTIVE: To investigate the effect of Pseudomonas aeruginosa infection on clinical parameters in Chinese patients with noncystic fibrosis and steady-state bronchiectasis. DESIGN: Prospective, cross-sectional clinicomicrobiological study with informed consent. SETTING: Consecutive outpatient recruitment from a specialist bronchiectasis respiratory clinic. PATIENTS: Outpatients (n = 100; 62 women; 55.1+/-16.7 years old; FEV1/FVC 1.4+/-0.7/2.1+/-0.9 L), who had stable respiratory symptoms for more than 3 weeks. MEASUREMENTS AND RESULTS: Respiratory pathogens isolated from the sputum were: Pseudomonas aeruginosa (33), Haemophilus influenzae (10), Moraxella catarrhalis (2), other Gram-negative bacilli (5), Streptococcus pneumoniae (6), Staphylococcus aureus (5), mycobacteria (3), and yeast (1). Clinical parameters in patients with positive isolation of P aeruginosa were compared with those without the organism in the sputum culture (non-P aeruginosa). In the P aeruginosa group, the FEV1/FVC ratio and sputum volume were lower (p < 0.005) and higher (p < 0.0001), respectively, than those of the non-P aeruginosa group. The FEV1/FVC ratio (< 60%) and sputum volume (grading > 5) were independently associated with a positive sputum isolation of P aeruginosa with odds ratios of 3.1 (confidence interval [CI] 1.2 to 8.4; p < 0.01) and 4.7 (CI 1.6 to 13.3; p < 0.001), respectively. CONCLUSIONS: P aeruginosa is the predominant respiratory pathogen isolated in the sputum of Chinese patients with steady-state bronchiectasis, and its isolation is associated with high sputum output (> or = 75th quartile) and moderately severe airflow obstruction (FEV1/FVC < 60%). 相似文献
49.
M Ogawa T Yamaguchi A Setiyono T Ho H Matsuda S Furusawa H Fukushi K Hirai 《Canadian Metallurgical Quarterly》1998,143(12):2327-2341
A flow cytometric virus binding assay that directly visualizes the binding of infectious bursal disease virus (IBDV) to its target cells was established. The chicken B lymphoblastoid cell line, LSCC-BK3, which is permissive for IBDV infection, bound high levels of the virus. Another B lymphoblastoid cell line, LSCC-1104-B1, bound low levels of the virus, although it was nonpermissive. No virus binding was detected in nonpermissive T lymphoblastoid cell lines. In the binding assay to heterogeneous cell populations of chicken lymphocytes, IBDV (a highly virulent OKYM strain) bound to 94% cells in the lymphocytes prepared from the bursa of Fabricius, 37% cells in those prepared from the spleen, 3% cells in those prepared from the thymus, and 21% cells in those prepared from the blood. Most of the cells, which bound the virus, were surface immunoglobulin M (SIgM)-positive, but a small number of them were SIgM-negative. Additionally, the binding of IBDV to the LSCC-BK3 cells was affected by treatment of the cells with proteases and N-glycosylation inhibitors. These findings may indicate that the IBDV host range is mainly controlled by the presence of a virus receptor composed of N-glycosylated protein associated with the subtle differentiation stage of B-lymphocytes represented mostly by SIgM-bearing cells. 相似文献
50.
Kell and Kx are two quantitatively minor proteins from the human erythrocyte membrane which carry blood groups antigens and are thought to be a metalloprotease and a membrane transporter, respectively. In the red cell membrane, these proteins form a complex stabilized by disulfide bond(s). Phosphorylation status of these proteins was studied, in the presence or absence of effectors of several kinases, either on intact cells incubated with [32P]-orthophosphate or on ghosts incubated with [gamma-32P]ATP. Purification of Kell-Kx complex, by immunochromatography on an immobilized human monoclonal antibody of Kell blood group specificity allowed to establish that (i) neither protein is phosphorylated on tyrosine; (ii) the Kell protein is a putative substrate for Casein Kinase II (CKII) and Casein Kinase I (CKI) but not for protein kinase C (PKC), whereas Kx protein is phosphorylated by CKII and PKC but not by CKI; (iii) Protein Kinase A neither phosphorylates the Kell nor the Kx proteins. 相似文献