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1.
目的:合成并表征一种属于植物生长激素的席夫碱类化合物.方法:由5-硝基水杨醛和3,5-二羟基苯甲酰肼在甲醇溶液中反应得到N′-(5-硝基-2-羟基苯亚甲基)-3,5-二羟基苯甲酰肼.结果:用单晶X-射线衍射法测得其结构并表征,同时通过抗菌实验证明其在一定浓度下具有明显的抗菌活性.结论:这种席夫碱类化合物在某种程度上具有明显的抗菌活性. 相似文献
2.
The advantages of a four-bedded purpose-built general intensive care unit in a district general hospital are described. In addition to 1,447 inpatients treated between January 1968 and December 1971 the unit was used to conduct outpatient investigations. This has filled an important gap in conventional arrangements, and is practical and economical. The unit has proved to have advantages, not only for seriously ill patients but also has benefited the hospital in other ways. It has been of material assistance in recruiting and training nursing and medical staff and has been welcomed and supported by patients and their relatives. It has also attracted practical support from voluntary organizations whose generosity has enabled much additional equipment to be purchased. 相似文献
3.
N V Tsvetkova M M Mile?kovskaia I M Gruber V M Poliachenko V V Butkus 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1987,(4):19-22
A strain producing the new specific restriction endonuclease BcmI has been found in the Bacillus generum. The enzyme has been purified by chromatography on the blue sepharose, phosphocellulose PII, heparin sepharose. The analogous purification has been obtained when the blue sepharose has been substituted for the orange sepharose, the home produced sorbent. The BcmI enzyme has been shown by the substrate specificity definition to be an isoschizomer of the restriction endonuclease ClaI. 相似文献
4.
Geary TG 《Trends in parasitology》2005,21(11):530-532
Ivermectin has been on the veterinary market for almost a quarter of a century and has been approved for human use for 18 years. Its use has revolutionized the treatment of nematode and arthropod parasites in animals and has provided hope for the control or even eradication of filariases in humans. Although much remains to be learned about how the drug works and how resistance to it will develop, it has earned the title of "wonder drug". 相似文献
5.
一些小麦白粉病抗源抗性基因鉴定分析 总被引:8,自引:2,他引:6
研究鉴定了我国37份小麦白粉病抗源的抗性基因,19份材料不具有任何抗性基因;6份材料具有来自1BL/1RS易位系的抗性基因Pm8;5份材料具有抗性基因Pm5a;3份分别具有对目前欧洲所有生理小种均抗的抗性基因Pm21、Pm16和Pm12;4份材料具有新的抗性基因。 相似文献
6.
口腔解剖生理学是口腔专业重要的基础课程,本学科理论知识内容复杂,实践操作技能要求高,给老师和初学者在教与学的过程中带来很大的压力。本学科自开课以来一直在探讨选择最佳的教学方法,随着计算机图像技术的不断完善,CT三维重建也随之问世,颌面部三维重建模型,逼真形象,便于操作和理解,大大降低了学习难度,显著提高了教学质量,取得相当客观的效果。 相似文献
7.
The unidirectional flagellar motor of Rhodobacter sphaeroides WS8 can rotate either clockwise or counterclockwise: characterization of the flagellum under both conditions by antibody decoration.
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A variant of Rhodobacter sphaeroides WS8 has been isolated which when tethered has a cell body that rotates counterclockwise instead of clockwise. Antibody decoration in vivo has shown that the filament on the variant has handedness opposite to that of the normal form. In both cases the cell body is pushed by the rotating flagellum. 相似文献
8.
Lise Togeby 《Ethnic and racial studies》2013,36(6):1137-1154
Abstract Since the end of the 1960s Denmark, once an ethnically homogeneous country, has become more heterogeneous as a result of immigration by foreign workers and refugees. The question is how has this development influenced the attitudes in Denmark towards immigrants? The saliency of the immigrant issue has certainly grown, but contrary to expectations, the level of ethnocentrism has changed very little. If anything, the Danish population has become less prejudiced and more tolerant during the last thirty years. This conclusion, based on a number of national surveys, is even more conspicuous as the level of unemployment has increased in the same period. 相似文献
9.
E Kolodziejczyk J M Saurel J Bagnol J Attal M R Fernandez-Graf A Saied 《Histochemistry》1988,88(2):165-169
The acoustic microstructure of mouse small intestine has been studied with a transmission acoustic microscope working at 1 GHz and the influence of the histologic processing on the microacoustic pattern has been tested. Unstained thin sections provide pictures rich in details and highly contrasted. Gelatin has been used as hydrosoluble embedding medium and has been compared to paraffin. The former embedding procedure retained the viscoelastic properties of the specimen far more and provided the most detailed pictures. Osmiun tetroxide has been used to demonstrate acoustic staining. 相似文献
10.
E. Kolodziejczyk J. M. Saurel J. Bagnol J. Attal M. R. Fernandez-Graf A. Saied 《Histochemistry and cell biology》1988,88(2):165-169
Summary The acoustic microstructure of mouse small intestine has been studied with a transmission acoustic microscope working at 1 GHz and the influence of the histologic processing on the microacoustic pattern has been tested. Unstained thin sections provide pictures rich in details and highly contrasted. Gelatin has been used as hydrosoluble embedding medium and has been compared to paraffin. The former embedding procedure retained the viscoelastic properties of the specimen far more and provided the most detailed pictures. Osmiun tetroxide has been used to demonstrate acoustic staining. 相似文献
11.
The propagation characteristics of symmetric surface plasmon polariton mode in a glass–metal–glass waveguide are presented. Gallium lanthanum sulfide has been taken as the glass and silver (Ag) has been used as the metal. The analysis has been done both numerically and analytically. A two-dimensional finite-difference time-domain-based simulation model has been developed in order to analyze the propagation characteristics numerically. The obtained results using numerical and analytical methods have been compared and a very good agreement has been found. 相似文献
12.
C A Ramilo G C Zafaralla L Nadasdi L G Hammerland D Yoshikami W R Gray R Kristipati J Ramachandran G Miljanich B M Olivera 《Biochemistry》1992,31(41):9919-9926
Three neurotoxic peptides from the venom of Conus striatus have been purified, biochemically characterized, and chemically synthesized. One of these, an acetylcholine receptor blocker designated alpha-conotoxin SII, has the sequence GCCCNPACGPNYGCGTSCS. In contrast to all other alpha-conotoxins, SII has three disulfide bonds (instead of two), has no net positive charge, and has a free C-terminus. The other two paralytic peptides are Ca channel-targeted omega-conotoxins, SVIA and SVIB. omega-SVIA is the smallest natural omega-conotoxin so far characterized and has the sequence CRSSGSPCGVTSICCGRCYRGKCT-NH2. Although omega-conotoxin SVIA is a potent paralytic toxic in lower vertebrate species, it was much less effective in mammals. The third toxin, omega-conotoxin SVIB, has the sequence CKLKGQSCRKTSYDCCSGSCGRSGKC-NH2. This peptide has a different pharmacological specificity from other omega-conotoxins previously purified from Conus venoms; only omega-conotoxin SVIB has proven to be lethal to mice upon ic injection. Binding competition experiments with rat brain synaptosomal membranes indicate that the high-affinity binding site for omega-conotoxin SVIB is distinct from the high-affinity omega-conotoxin GVIA or MVIIA site. 相似文献
13.
G Colonna G Irace E Bismuto L Servillo C Balestrieri 《Comparative biochemistry and physiology. A, Comparative physiology》1983,76(3):481-485
The heart ventricle myoglobin of bluefin tuna has been purified to an apparent homogeneity. The amino acid analysis has revealed only a limited number of substitutions between the myoglobins of yellowfin and bluefin tuna. The alpha-helix content of tuna myoglobin has been found considerably lower than that of mammalian myoglobin. No correlation has been discovered between the conformational stability and alpha-helix content. Denaturation experiments have shown that the whole structure of tuna myoglobin results from the interaction of two structural units which represent the product of independent folding processes. The structure of tuna myoglobin has been found more open and disorganized than that of sperm whale. This result has been related to the low content of electrostatic interactions and explained in terms of evolutive adaptations. 相似文献
14.
O I Brindak V B Aleshin D Chaba O Dobotsi 《Biulleten' eksperimental'no? biologii i meditsiny》1989,107(1):91-93
Leydig cells reaction of rabbits testis to choriogonin action has been investigated during the prenatal period of ontogenesis. It has been found, that these cells sensitivity to the hormones studied has been detected at the early stages of embryogenesis. The specialization of Leydig cells response to choriogonin, thyrotrophin and prolactin in the process of prenatal period has been shown. 相似文献
15.
Protein families and RNA recognition 总被引:1,自引:0,他引:1
This minireview series examines the structural principles underlying the biological function of RNA-binding proteins. The structural work of the last decade has elucidated the structures of essentially all the major RNA-binding protein families; it has also demonstrated how RNA recognition takes place. The ribosome structures have further integrated this knowledge into principles for the assembly of complex ribonucleoproteins. Structural and biochemical work has revealed unexpectedly that several RNA-binding proteins bind to other proteins in addition to RNA or instead of RNA. This tremendous increase in the structural knowledge has expanded not only our understanding of the RNA recognition principle, but has also provided new insight into the biological function of these proteins and has helped to design better experiments to understand their biological roles. 相似文献
16.
Although the biochemistry of triglyceride synthesis has been studied for decades, an understanding of the molecular processes involved has been lacking. The recent cloning of a gene encoding acyl coenzyme A : diacylglycerol acyltransferase, an enzyme that catalyses the final step in triglyceride synthesis, has opened this area to molecular investigation and has begun to provide new insights into triglyceride metabolism. 相似文献
17.
Breast augmentation using the expander mammary prosthesis 总被引:1,自引:0,他引:1
H Becker 《Plastic and reconstructive surgery》1987,79(2):192-199
The expandable mammary prosthesis that has been successfully used for breast reconstruction has been modified for breast augmentation procedures. A new microreservoir that can be buried subcutaneously for extended periods has been developed. The unique design of this implant allows its size to be adjusted postoperatively as many times as desired, thus eliminating the possibility of a second operation to replace an implant whose size is unsatisfactory. Accurate, aesthetically satisfactory results are possible because the volume adjustments are made after the swelling has decreased and the implant has settled into position. Almost all patients offered this opportunity requested postoperative volume adjustments. The results of 59 patients are reported. The surgery was performed over a 3-year period, with the average follow-up time being 6 months. The incidence of capsular contracture has been less than 10 percent. Leakage was a problem in the original implant design; however, since the introduction of the new valve, there has been no leakage to date. 相似文献
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19.
Staphylococcus aureus (S. aureus) has entered the spotlight as a globally pervasive drug-resistant pathogen. While historically associated exclusively with hospital-acquired infections in immunocompromised hosts, the methicillin-resistant form of S. aureus has been spreading throughout communities since the 1990s. Indeed, it has now become a common household term: MRSA. S. aureus has developed numerous mechanisms of virulence and strategies to evade the human immune system, including a host of surface proteins, secreted enzymes, and toxins. In hospital intensive care units, the proportion of MRSA-related S. aureus infections has increased strikingly from just 2 percent in 1974 to 64 percent in 2004. Its presence in the community has been rising similarly, posing a significant public health burden. The growing incidence of MRSA unfortunately has been met with dwindling efforts to develop new, more effective antibiotics. The continued emergence of resistant strains of bacteria such as MRSA demands an urgent revival of the search for new antibiotics. 相似文献
20.
The effect of flavin mononucleotide (FMN) on the activity of the I- and D-forms of rabbit skeletal muscle glycogen synthase has been studied for the first time. FMN has been shown to inhibit in a noncompetitive fashion the both forms of the enzyme, the D-form being more sensitive to the effect of the inhibitor. It has been shown also that glycogen synthase has three different sites involved in the interaction with inhibitors, namely, and active site, an adenyl nucleotide binding site and a FMN binding site. FMN binding has been shown to occur mostly via the isoalloxasine ring. 相似文献