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991.
The interaction between an antibody molecule and a protein antigen is an example of "natural" protein modelling. Amino acids of the antigen-binding site consisting of three hypervariable segments (L1, L2, L3) of the light (L) and three (H1, H2, H3) of the heavy (H) chain of an antibody molecule interact with amino acids present in an epitope of a protein. A ten-residue peptide was synthesized with an amino acid sequence analogous to the hypervariable L3 segment of a monoclonal antibody directed against lysozyme. The peptide was immobilized on CH-Sepharose 4B and the affinity adsorbent was used to purify lysozyme added to a detergent extract of insect cells infected with a recombinant baculovirus. This methodology may also be applicable to other antigen-antibody combinations, in immunoaffinity chromatography for selective purification of a protein or in an immunosensor for detection of a protein.  相似文献   
992.
Summary The quantitative oxidation of thiocyanate by ceric sulphate has been studied and the method utilised for the determination of small quantities of cerium by back titrating the excess (unreacted) KSCN against standard mercuric nitrate with diphenylcarbazone as the internal indicator. Accurate results are obtained under the specified experimental conditions and the procedure is more simple and direct than that adopted during earlier studies of the above redox reaction.Grateful thanks of the author are due to Professor S. S. Joshi for facilities during the work and to the National Institute of Sciences of India for award of a Research Fellowship.  相似文献   
993.
994.
Phosphorescence and excitation spectra have been measured of Fe3+-doped LiAl5O8, β-NaAlO2, Na-silicate glass and crystalline alumino-silicates. All excitation spectra fit quite well the Tanabe-Sugano diagram for a high spin d5 configuration. The expected tetrahedral site symmetry of Fe3+ in the host lattices and the value of the crystalline field parameter are strong evidence for phosphorescence of Fe3+ ions in tetrahedral oxygen coordination.  相似文献   
995.
In this work attention has been focused on the effects of papermaking beating, web forming and sizing operations on the physical/chemical surface properties of bleached Eucalyptus globulus kraft fibres. Inverse gas chromatography (IGC) was used to determine the dispersive component of surface tension (γsd) as well as the acidic/basic character (according to the Lewis concept) of the solid surfaces (pulp fibres and pulp handsheets). The results have shown that the main effect of beating is to increase the fibre's Lewis acidic character. Web forming caused a strong decrease in γsd and significant increments in the adhesion works of both acidic and basic probes, lowering the ratio between the two. Nevertheless, the surface of handsheets still exhibited a dominant acidic character. The sizing operation did not change the dispersive component of the surface tension significantly but decreased the difference between the adhesion works of the acidic and basic probes, rendering the handsheet surface less Lewis acidic and more Lewis basic. Thus, although internal sizing is expected to strongly influence liquid spreading at the paper surface and liquid penetration of the fibre's network, it is concluded that beating and web forming lead to important changes in the surface energetic properties of the Eucalyptus globulus kraft fibres.  相似文献   
996.
Optimal analysis conditions can be selected and errors caused by variations in the excitation conditions can be decreased or corrected based on the results of studying the temperature distribution along the plasma torch height and correlations between the analytical signal Y and the correcting signal Z that follows the temperature variation in the plasma torch. The obtained correlations can be used to create automated feedback between the spectrum recording system and the mode control system of the plasmatron.  相似文献   
997.
Many types of corrosion phenomena are controlled by the ionic composition of a small volume of solution at the surface. Localized corrosion and atmospheric corrosion are two examples in which < 1 μl of solution can cause dramatic damage. Ion chromatographic (IC) techniques have been used to analyze these solutions in order to gain a better understanding of the mechanisms which govern them. Two examples are presented. The presence of minor alloying elements at localized corrosion sites in two aluminum alloys has been demonstrated, indicating non-stoichiometric dissolution of the alloy during localized corrosion. In addition, IC analysis allowed the determination of the species responsible for the atmospheric corrosion failure of electrical connectors, including their likely origin.  相似文献   
998.
We have synthesized secondary and tertiary enamines, derivatives of 1,2,3,4,4a,5,6,10b-octahydrophenanthridine, and we have considered the Z,E-isomerism of the enaminoesters.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1374–1377, October, 1993.  相似文献   
999.
2.5-Diphenyl hexane, a model compound of polystyrene was metalated by a complex of secondary butyllithium and N,N,N′,N′-tetramethylethylene diamine in heptane. At various times, the lithiated dimer was quenched with deuterated methanol. The deuterated compound was examined by mass spectrometry and from the deuterium content, the degree of lithiation was determined. The effects of the concentration of styrene units, secondary butyllithium and diamine on the lithiation were studied at 20 C and ?20 C. The overall rate of metalation was first order with respect to the styrene units concentration and half-order with respect to sec. butylithium-TMEDA complex concentration. The kinetic results were explained by the presence at 20 C of the 1 4 complex (1 sec. BuLi 4 TMEDA) and at ?20 C of the 1–2 complex (1 sec. BuLi 2 TMEDA).  相似文献   
1000.
The behaviour of transplutonium and rare-earth elements on anion and cation exchangers in solutions of H3PO4 and H2SO4 in the presence of oxidants (KBrO3, PbO2, (NH4)2S2O8) and in HCl solutions in the presence of reducing agents [Zn(Hg), Eu2+] depending on acid concentration as well as on oxidant content and nature in solution or in resin and other factors has been studied. Effective methods of Bk(IV), Ce(IV), Am(VI), Eu(II) and Md(II) separation from trivalent TPE and REE, as well as continuous methods of isolation of isotopically pure radionuclides250Bk,144Pr by using ion exchangers and inorganic acid solutions have been developed.  相似文献   
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