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11.
Sergei Kan 《American anthropologist》2003,105(3):648-649
Against Culture: Development, Politics, and Religion in Indian Alaska. Kirk Dombrowski. Lincoln: University of Nebraska Press, 2001. 247 pp. 相似文献
12.
David O. Hall Sergei A. Markov Yoshitomo Watanabe K. Krishna Rao 《Photosynthesis research》1995,46(1-2):159-167
Natural photosynthesis may be adapted to advantage in the development of clean energy technologies. Efficient biocatalysts that can be used in solar energy conversion technologies are the cyanobacteria. Photobioreactors incorporating cyanobacteria have been used to demonstrate (a) the production of hydrogen gas, (b) the assimilation of CO2 with the production of algal biomass, (c) the excretion of ammonium, and (d) the removal of nitrate and phosphate from contaminated waters.Abbreviations Chl
chlorophyll
- DW
dry weight
- MSX
L-methionine-D-L-sulphoximine
- PAR
photosynthetically active radiation
- PU
polyurethane
- PV
polyvinyl
- PVC
polyvinylchloride 相似文献
13.
V. V. Zverev N. P. Kuzmin L. A. Zuyeva E. I. Burova A. A. Alexandrov I. A. Khmel 《Plasmid》1984,12(3):203-205
Restriction maps have been constructed for the colicinogenic plasmids (ColA, ColD, and ColK. Their regions of homology with the ColE1 plasmid and its deletion derivative pAO3 carrying the region responsible for autonomous replication of ColE1 plasmid were determined by means of blotting hybridization and heteroduplex analysis. The plasmids ColA, ColD, and ColK were shown to contain DNA fragments homologous to the region of ColE1 involved in the regulation of replication. 相似文献
14.
John Leo Abernethy Gary F. Kuzmin Charles M. Lovett Jr. William A. Wilson 《Bioorganic chemistry》1980,9(4):440-449
Hydrazides of five N-acylamino acids have been used alone as substrates for papain catalysis to yield N1,N2-diacylhydrazines. With the exception of N-(benzyloxycarbonyl)(Z)-
-alanine hydrazide, they were very effective as both acylating agents of the enzyme and nucleophiles in attacking the enzyme-substrate intermediate. Although Z-
-alanine hydrazide was a minimal acylating agent, it was a satisfactory nucleophile. The most favorable reaction involved Z-
-alanine hydrazide in producing N1,N2-bis(Z-
-alanyl)hydrazine. When Z-
-alanine hydrazide was the substrate, this same chiral diacylhydrazine was formed along with meso N1-(Z-
-alanyl)-N2-(Z-
-alanyl)hydrazine. For the acylation step, the enzyme displayed powerful, essentially stereospecific, bias toward the
enantiomer. Once the thioester intermediate was formed, little preference was detected for attack by the enantiomers as nucleophiles. The most direct procedure for synthesis of substrates was conversion of Z-amino acids to their esters by means of dry HCl in an absolute alcohol. Treatment with hydrazine produced the hydrazides in excellent yield. 相似文献
15.
Boris Yu. Zaslavsky Anna A. Borovskaya Alevtina K. Lavrinenko Alexei Yu. Lisichkin Yurii A. Davidovich Sergei V. Rogozhin 《Chemistry and physics of lipids》1980,26(1):49-55
The lytic action of several homologous series of surfactants including N-acyl derivatives of the Na-salt of amino acids on the egg lecithin multilamellar liposomes was examined. The affinity for the lipid membrane and the solubilising capacity of the agents were estimated. The contribution of a CH2 group and that of the polar head group of surfactants to the free energy of the agent's binding to the membrane were evaluated. The results obtained indicate that the contribution of a CH2 group to the free binding energy depends on the nature of the surfactants' head group. This dependence is attributed to either various localisation of the agent's molecules in the lipid bilayer or to different properties of the agent's hydrocarbon tails. The contributions of the head groups of the surfactants are assumed to reflect the affinity of these head groups for the lecithin polar head group at the membrane interface. The results obtained indicate some degree of specificity involved in the interactions of the head groups. 相似文献
16.
John Leo Abernethy Charles M. Lovett Gary F. Kuzmin John D. Kuhlberg William A. Wilson 《Bioorganic chemistry》1981,10(2):189-199
Restriction of hydrazides of N-blocked amino acids mainly to electrophilic action, in acylating crude papain, has been achieved by means of a large amount of aniline, with formation of insoluble anilides of N-acylamino acids. Similarly, nucleophilic behavior, on the part of a hydrazide, has been promoted by introducing a large proportion of an N-acylamino acid to produce an insoluble N1,N2-diacylhydrazine. Achiral, chiral and racemic hydrazides and their corresponding N-acylamino acids were utilized in the study. Among the more informative combinations of reactants were Z-dl-alanine hydrazide with aniline and then with Z-glycine. A stereospecific response in the former situation produced Z-l-alanine anilide. In the latter case, a stereoselective interaction produced Z-Gly-NHNH-lAla-Z more rapidly than Z-Gly-NHNH-d-Ala-Z. The final incubation period yielded an optically pure D product. Differences in stereochemical control have been delineated in terms of different spatial aspects for interactions at the S and S′ subsites of sulfhydryl proteolytic enzymes. A racemic reactant encountered firm stereospecificity as an electrophile at the S subsite but only modest stereoselectivity as a nucleophile at the S′ subsite. The ready availability of crude papain allows an effective procedure for the synthesis of substantial quantities of diacylhydrazines. 相似文献
17.
The partition behaviour of a number of ionic and nonionic surface-active substances in the dextran-polyethylene glycol system was examined. The strictly linear dependence of the logarithm of the partition coefficient on the alkyl chain length for a homologous series of nonionic surfactants provides a measure of the difference in the relative hydrophobicity between the two phases of the system, in terms of the free energy of transfer of a CH2 group from the bottom phase to the top phase of the system. This difference is found to be altered in the presence of NaCl or KCl depending on the salt concentration. It is concluded that the influence of the salt composition of the system on the distributed solutes' behaviour may be due to the effect of the ions on the hydrophobicity difference between the phases.The partition of ionic amphiphiles is found to be dependent on the relative hydrophobicity of the compounds as well as on their charge. It is shown that at salt concentrations up to about 0.1 M NaCl the charged solute partition is determined by its charge as well as its relative hydrophobicity, in the presence of 0.1–0.2 M NaCl the substance distribution is highly dependent on its charge and slightly on its lipophility. At the salt concentrations above 0.2 M the solute partition is determined just by its hydrophobic character and seems to be totally independent of its charge. It is concluded that the partition technique can be used for analytical purposes. The method seems to be unique in providing quantitative information on the amphiphilic surface properties of the solutes being partitioned. 相似文献
18.
Isolation of calcium pump system and purification of calcium ion-dependent ATPase from heart muscle.
D O Levitsky M K Aliev A V Kuzmin T S Levchenko V N Smirnov E I Chazov 《Biochimica et biophysica acta》1976,443(3):468-484
The procedure for the isolation of the highly active fraction of sarcoplasmic reticulum from pigeon and dog hearts is described. The method is based on the partial loading of heart microsomes with calcium and oxalate ions and the precipitation of loaded vesicles in sucrose and potassium chloride concentration gradients. Preparations obtained possess high activity of Ca2+-dependent ATPase and are also able to accumulate up to 10 mumol Ca2+ per mg protein. Purification of sarcoplasmic reticulum membranes is accompanied by a decrease in concentration of cytochrome a+a3 and an increase in the content of [32P]phosphoenzyme. The basic components in "calcium-oxalate preparation" from hearts are proteins with molecular weights of about 100000 (Ca2+-dependent ATPase) and 55000 Calcium-oxalate preparation from pigeon hearts was used for subsequent purification of Ca2+-dependent ATPase. Specific activity of purified enzyme from pigeon hearts is 12-16 mumol Pi/min per mg protein. Enzyme activity of purified Ca2+-dependent ATPase is inhibited by EGTA and is not sensitive to azide, 2,4-dinitrophenol and ouabain. The data obtained demonstrate the similarity of calcium pump systems and Ca2+-dependent ATPases isolated from heart and skeletal muscles. 相似文献
19.
Sergei Golovatch 《ZooKeys》2014,(426):11-16
The little that remains of Motschoulsky’s myriapodological legacy in the collection of Moscow’s Zoological Museum proves to be of very limited value. Only one species of Diplopoda described by Motschoulsky, the Caucasian Hirudisoma roseum (Victor, 1839), is still in use, yet requiring a neotype designation, whereas the remaining few myriapod names he proposed are either nomina dubia or nomina nuda. The former include Scolopendra pentagramma Motschoulsky, 1866 (Chilopoda, Scolopendromorpha, Scolopendridae) and Strongylosoma carinulatum Motschoulsky, 1866 (Diplopoda, Polydesmida, Paradoxosomatidae), both from Japan, as well as Julus costulatus Motschoulsky, 1851 (Diplopoda, Callipodida, Schizopetalidae?), from Montenegro, because their type material is either inadequate or missing. 相似文献
20.
Limnology - Green microalgae are of the utmost importance to aquatic ecosystems globally, as they are primary producers and major food sources for many organisms. Microalgae of the genus... 相似文献