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141.
本文主要就目前市场上推出的螺杆式制冷压缩机新产品作一解剖,综述了许多新技术的应用,以供读者参考。 相似文献
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TD Randall AW Heath L Santos-Argumedo MC Howard IL Weissman FE Lund 《Canadian Metallurgical Quarterly》1998,8(6):733-742
Dendrimers represent a new class of highly branched polymers whose interior cavities and multiple peripheral groups facilitate potential applications in biomedicine and bio-organic chemistry. Major advances in the past year were made in the synthesis and study of new carbohydrate, nucleic acid, and peptide dendrimers, as well as in the use of dendrimers as magnetic resonance imaging contrast agents, as agents for cellular delivery of nucleic acids, and as scaffolds for biomimetic systems. 相似文献
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TP Kogan B Dupré H Bui KL McAbee JM Kassir IL Scott X Hu P Vanderslice PJ Beck RA Dixon 《Canadian Metallurgical Quarterly》1998,41(7):1099-1111
Reports of a high-affinity ligand for E-selectin, sialyl di-Lewis(x) (sLe(x)Le(x), 1), motivated us to incorporate modifications to previously reported biphenyl-based inhibitors that would provide additional interactions with the protein. These compounds were assayed for the ability to inhibit the binding of sialyl Lewis(x) (sLe(x), 2) bearing HL-60 cells to E-, P-, and L-selectin fusion proteins. We report that dimeric or trimeric compounds containing multiple components of simple nonoligosaccharide selectin antagonists inhibit sLe(x)-dependent binding with significantly enhanced potency over the monomeric compound. The enhanced potency is consistent with additional binding interactions within a single selectin lectin domain; however, multivalent interaction with multiple lectin domains as a possible alternative cannot be ruled out. Compound 15e (TBC1269) showed optimal in vitro activity from this class of antagonists and is currently under development for use in the treatment of asthma. 相似文献
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HF Rodgers CM Irvine IL van Wezel TC Lavranos MR Luck Y Sado Y Ninomiya RJ Rodgers 《Canadian Metallurgical Quarterly》1998,59(6):1334-1341
During follicular development the proliferative and differentiated state of the epithelioid granulosa cells changes, and the movement of fluid across the follicular basal lamina enables the formation of an antrum. Type IV collagen is an important component of many basal laminae. Each molecule is composed of three alpha chains; however, six different type IV collagen chains have been identified. It is not known which of these chains are present in the follicular basal lamina and whether the type IV collagen composition of the basal lamina changes during follicular development. Therefore, we immunolocalized each of the six chains in bovine ovaries using antibodies directed to the nonconserved non-collagenous (NC) domains. Additionally, dissected follicles were digested with collagenase to release the NC domains, and the NC1 domains were then detected by standard Western immunoblot methods. The follicular basal lamina of almost all primordial and preantral follicles was positive for all type IV collagen alpha chains. Colocalization of type IV collagen and factor VIII-related antigen allowed for discrimination between the follicular and endothelial basal laminae. Type IV collagen alpha1, alpha2, alpha3, alpha4, and alpha5 chains were present within the follicular basal lamina of only a proportion of antral follicles (17 of 22, 20 of 21, 15 of 18, 14 of 28, and 12 of 23, respectively), and staining was less intense than in the preantral follicles. Staining for the alpha1 and alpha2 chains was diffusely distributed throughout the theca in regions not associated with recognized basal laminae. The specificity of this immunostaining for alpha1 and alpha2 chains of type IV collagen was confirmed by Western immunoblots. As well as being detected in the basal lamina of approximately half of the antral follicles examined, type IV collagen alpha4 also colocalized with 3beta-hydroxysteroid dehydrogenase-immunopositive cells in the theca interna. Type IV collagen alpha6 was detected in the basal lamina of only one of the 16 antral follicles examined. Thus, the follicular basal lamina changes in composition during follicular development, with immunostaining levels being reduced for all type IV collagen chains and immunoreactivity for type IV collagen alpha6 being lost as follicle size increases. Additionally, immunoreactivity for alpha1 and alpha2 appears in the extracellular matrix of the theca as it develops. 相似文献
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