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排序方式: 共有432条查询结果,搜索用时 15 毫秒
91.
目的:采用交流示波极谱滴定法测定了盐酸环丙沙星及其制剂的含量。方法:在pH5.0-5.5的醋酸-醋酸钠缓冲液溶液中,环丙沙星与四苯硼钠定量反应形成1:1沉淀。过量的四苯硼钠用醋酸亚铊标准溶液回滴至示波极谱图上四苯硼钠切口消失。结果:该法平均回收率为99.18%,RSD为0.49%。结论:本法简便,快速,结果准确,可靠。 相似文献
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95.
合欢皮中三萜皂甙元的研究 总被引:3,自引:0,他引:3
合欢皮中三萜皂甙元的研究陈四平张如意(北京医科大学植化教研室,北京100083)中药合欢皮(Albizziaecortex)为合欢(AlbizziaejulibrisinDurazz)树皮。具解郁安神,活血消肿功能。用于心神不安,忧郁失眠,肺痈疮肿... 相似文献
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The role of amino-terminal residues of the heavy chain of factor IXa in the binding of its cofactor, factor VIIIa 总被引:1,自引:0,他引:1
The purpose of this study is to determine which residues of the factor IXa heavy chain are important for interaction with the cofactor of factor IXa, factor VIIIa. Because the monoclonal antibody (MoAb) FXC008 inhibits interaction between factors IXa and VIIIa, and because it also reacts with residues 181-310 of the factor IXa heavy chain, we used the computer-modelled structure of the factor IXa heavy chain to select charged surface residues likely to interact with FXC008 and/or factor VIIIa. We made mutations in the region of residues 181-310 of the heavy chain of factor IX, and replaced these amino acids individually with those located at the same position in factor X. The mutated factor IX retained complete clotting activity and thus interacted normally with factor VIIIa. Five mutant proteins (factor IXK214F, factor IXK228R, factor IXE240Q, factor IXK247V, and factor IXN260K) reacted with heavy chain-specific MoAbs FXC008 and A-5. Neither factor IXD276K nor factor IXR248H bound to FXC008. Factor IXR252V had reduced affinity to FXC008. Our results suggest the following: (1) factor IXa residues 214, 228, 240, 247, 248, 252, 260, and 276 are not involved in specific interaction with factor VIIIa; and (2) the FXC008 and factor VIIIa binding sites may not share critical residues. 相似文献
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Hypermethylation of the 5' region of the calcitonin gene is a property of human lymphoid and acute myeloid malignancies 总被引:11,自引:0,他引:11
Baylin SB; Fearon ER; Vogelstein B; de Bustros A; Sharkis SJ; Burke PJ; Staal SP; Nelkin BD 《Blood》1987,70(2):412-417
An abnormal increase in numbers of CCGG sites methylated in the 5' region of the human calcitonin (CT) gene occurred in tumor cell DNA samples from 90% (17 of 19) of patients with non-Hodgkin's T and B cell lymphoid neoplasms and in 95% (21 of 22) of tumor cell DNA samples from patients with acute nonlymphocytic leukemia (ANLL). The changes were not seen in patients with chronic myelogenous leukemia (0 of 9). The abnormal methylation patterns appear to be a property only of transformed or malignant cells since they were not found in DNA from nonneoplastic adult tissues including sperm, early myeloid progenitor cells, benign lymphoid hyperplasia, peripheral lymphocytes stimulated to divide, or early myeloid progenitor cells (obtained by immunoaffinity using anti-My-10 antibody), but they did appear after Epstein-Barr virus transformation of lymphocytes. Moreover, during the course of therapy in patients with ANLL, the hypermethylation pattern reflects the presence of the leukemic clone even in normal-appearing granulocytes derived from this clone. The increased methylation of the CT gene may then provide an important molecular marker for biologic events in human cell transformation or tumor progression and may prove clinically useful in monitoring patients with lymphoid and acute myelogenous neoplasms. 相似文献
100.
The reliability and construct validity of the RAQoL: a rheumatoid arthritis-specific quality of life instrument 总被引:6,自引:4,他引:6
de Jong Z; van der Heijde D; McKenna SP; Whalley D 《Rheumatology (Oxford, England)》1997,36(8):878-883
The present study was designed to test the psychometric properties of the
RAQoL, a rheumatoid arthritis (RA)-specific quality of life (QoL)
instrument. All stages of the development were conducted simultaneously in
The Netherlands and the UK. The content of the draft measure was derived
from qualitative interviews with RA patients in both countries. The final
version of the RAQoL has 30 items with a 'yes'/'no' response format and
takes approximately 6 min to complete. Both language versions have high
internal consistency and test-retest reliability (> 0.9), and good
sensitivity to discriminate between groups with various disease activity
and severity. Given the excellent psychometric properties of the new
instrument, it will prove to be a valuable tool for assessing quality of
life in clinical trials and for monitoring patients in routine clinical
practice.
相似文献