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991.
Drabik T.J. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1994,82(11):1595-1622
It is appealing to contemplate how VLSI or wafer-scale integrated systems incorporating free-space optical interconnection might outperform purely electrically interconnected systems. This paper first provides a uniform treatment of a general class of optical interconnects based on a Fourier-plane imaging system with an array of sources in the object plane and an array of receptors in the image plane. Sources correspond to data outputs of processing “cells,” and receptors to their data inputs. A general abstract optical imaging model, capable of representing a large class of real systems, is analyzed to yield constructive upper bounds on system volume that are comparable to those arising from “3-D VLSI” computational models. These bounds, coupled with technologically derived constraints, form the heart of a design methodology for optoelectronic systems that uses electronic and optical elements each to their greatest advantage, and exploits the available spatial volume and power in the most efficient way. Many of these concepts are embodied in a demonstration project that seeks to implement a bit-serial, multiprocessing system with a radix-2 butterfly topology, and incorporates various new technology developments 相似文献
992.
993.
Phospholipid transfer protein (PLTP) was purified from lipoprotein-free human plasma, obtained upon treatment of plasma with dextran sulfate and Ca2+, by employing a series of column chromatography. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified PLTP showed a single main band, corresponding to the molecular mass of 78 kDa. However, isoelectric focusing of the purified preparation gave multiple bands with pI ranging from 4.3 to 5.1, indicative of microheterogeneity. Purified PLTP was shown to possess not only phospholipid transfer activity, but also high density lipoprotein (HDL) conversion activity (Tu, A.-Y., Nishida, H. I., and Nishida, T. (1990), FASEB J. 4, A2148; Jauhiainen, M., Metso, J., Pahlman, R., Blomqvist, S., van Tol, A., and Ehnholm, C. (1993) J. Biol. Chem. 268, 4032-4036). Isolated HDL3 was enlarged to the size of HDL2b upon incubation with purified PLTP for 6 h at 37 degrees C at the PLTP/HDL3 molar ratio of approximately 1:45. Both the HDL conversion and the phosphatidylcholine transfer activities of purified PLTP were effectively inhibited by rabbit anti-PLTP immunoglobulin G. The primary importance of PLTP in the HDL enlargement that occurs in human plasma upon incubation at 37 degrees C was shown by the strong inhibitory effect of the anti-PLTP immunoglobulin G. The process of PLTP-mediated HDL enlargement was accompanied by the release of apoproteins, primarily apoA-I. HDL3 enlargement mediated by PLTP was effectively inhibited by the addition of free fatty acids. 相似文献
994.
RY Poon K Yamashita JP Adamczewski T Hunt J Shuttleworth 《Canadian Metallurgical Quarterly》1993,12(8):3123-3132
Activation of the cyclin-dependent protein kinases p34cdc2 and p33cdk2 requires binding with a cyclin partner and phosphorylation on the first threonine residue in the sequence THEVVTLWYRAPE. We present evidence that this threonine residue, number 160 in p33cdk2, can be specifically phosphorylated by a cdc2-related protein kinase from Xenopus oocytes called p40MO15. Binding to cyclin A and phosphorylation of this threonine are both required to activate fully the histone H1 kinase activity of p33cdk2. In cell extracts, a portion of p40MO15 is found in a high molecular weight complex that is considerably more active than a lower molecular weight form. Wild-type MO15 protein expressed in bacteria does not possess kinase activity, but acquires p33cdk2-T160 kinase activity after incubation with cell extract and ATP. We conclude that p40MO15 corresponds to CAK (cdc2/cdk2 activating kinase) and speculate that, like p33cdk2 and p34cdc2, p40MO15 requires activation by phosphorylation and association with a companion subunit. 相似文献
995.
Arterial wall thickening may be quantitatively assessed by measuring the intima-media thickness (IMT) with high resolution ultrasound. Previous studies have shown a good inter/intraobserver variability of IMT measurements in the common carotid. In this study we evaluated the inter/intraobserver variability of IMT measurements in 10 randomly selected asymptomatic subjects (age 55.4 +/- 6). Two carotids and two femorals were studied in each subject. IMT for each patient was the average of five IMT measurements at the artery bifurcation. Three observers repeated the scanning and the measurements twice with no knowledge of the previous readings. The between observer coefficient of variation (CV) was 8.45%; the intraobserver CV (mean of carotids and femorals) varied from 4.4 to 5.1% for the three observers who measured IMT three times. The mean absolute difference between the first and the third measurement was 0.0738 mm. In conclusion IMT measurement variability is mostly due to differences between observers. The intraobserver variability is very small. IMT measurements at the carotid and femoral bifurcations have a low variability and are a good expression of atherosclerosis as they consider early lesions at the bifurcation level which may not be observed in the common carotid. 相似文献
996.
997.
Two cases with osteolytic bone metastases from cervical cancer and esophageal cancer treated by local therapy were reported. The first case is a 53-year-old female with bone metastases of left ischium developed 1 year after hysterectomy. She was treated by intratumor injection of sizofiran (SPG) 20 mg/w and radiation therapy. After 4 weeks, ischias pain decreased and bone lesion showed remarkable calcification (PR) 8th months later. The second case is a 58-year-old male with bone metastases of the left tibia and fibula developed 1 year after surgery. He was treated by intratumor injection of SPG 20 mg/w x 4 and OK-432 1.0 KE/w x 8 after radiation therapy. After 4 weeks, pain and swelling of left leg decreased and bone lesions showed remarkable calcification (PR) three months later. We suggest that intratumor injection of SPG and OK-432 with radiation therapy was effective for osteolytic bone metastases. 相似文献
998.
Three IgM class anti-H monoclonal antibodies (1E3, 1E5 and 3H1) were obtained from a BALB/c mouse immunized with human O type saliva. These antibodies were found to agglutinate red cells from O group and A and B subgroups but not from Bombay and para-Bombay individuals whose H antigen was barely detected by anti-H reagents. The agglutination reactions of these antibodies were inhibited by H antigens from human tissues. It was also demonstrated that both 1E3 and 3H1 reacted with H disaccharide (Fuc alpha 1-->2Gal beta), H type 1 (Fuc alpha 1-->2Gal beta 1-->3GlcNAc beta), H type 2 (Fuc alpha 1-->2Gal beta 1-->4GlcNAc beta), H type 3 (Fuc alpha 1-->2Gal beta 1-->3GalNAc alpha) and H type 4 (Fuc alpha 1-->2Gal beta 1-->3GalNAc beta) but not with Lea (Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta), Leb (Fuc alpha 1-->2Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta), X (Gal beta 1-->4[Fuc alpha-->3]GlcNAc beta) or Y (Fuc alpha 1-->2Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta). On the other hand, 1E5 was found to react with H type 1, H type 2, Leb and Y. Because of the unique reactivities against various fucosyl linkages these monoclonal antibodies could be useful not only as anti-H reagents but also as reagents for the structural analysis of fucosylated glycoconjugates. 相似文献
999.
1000.