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1.
Reddy PM Jindra PT Satz AL Bruice TC 《Journal of the American Chemical Society》2003,125(26):7843-7848
A series of pyrrole, imidazole-substituted bis-benzimidazole conjugates, Py-Py-Im-gamma-biBenz, Py-Py-gamma-biBenz, Py-Im-gamma-biBenz, and Im-Py-gamma-biBenz (1-4), were prepared in an attempt to target dsDNA sequences possessing both A/T and G/C bps. The dsDNA interactions and sequence specificity of the conjugates have been characterized via spectrofluorometric titrations and thermal melting studies. All conjugates form 1:1 complexes with dsDNA at subnanomolar concentrations. The Im moiety selectively recognizes a G/C bp embedded in the A/T-rich binding site. This represents the first clear example of sequence selective recognition in a 1:1 motif.(1) The equilibrium association constant (K(1)) for complexation of a specific nine-bp dsDNA site, 5'-gcggTATGAAATTcgacg-3', by conjugate 1 is approximately 2.6 x 10(9) M(-1). Displacement of the G/C position or G/C-->A/T substitution within the nine-bp site decreases the K(1) by approximately 8-fold, whereas two continuous G/C bps decrease the K(1) by approximately 50-fold magnitude. The K(1) values for seven-bp dsDNA, 5'-gcggtaTGAAATTcgacg-3' and 5'-gcggtaCAAAATTcgacg-3', binding sites by conjugates Py-Im-gamma-biBenz (3) and Im-Py-gamma-biBenz (4) are approximately 2.3 x 10(9) and approximately 1.2 x 10(9) M(-1), respectively. However, the conjugates with no Im moiety, Py-Py-gamma-biBenz (2) and Py-Py-Py-gamma-biBenz (5 and 6), are specific for seven- to nine-bp A/T-rich sites and single A/T-->G/C bp substitution within the binding site decreases the K(1) values by 1-2 orders of magnitude. 相似文献
2.
Summary Using a general nonlinear elasticity law for small strain, solutions of some elastomechanic problems are stated depending on only one coordinate. If Cartesian coordinates are applied, the equations of the simple tensile test are immediately given, by which the two arbitrary functions of the nonlinear elasticity law can easily be determined. In cylindrical and polar coordinates, the stresses are calculated in thick tubes and thick hollow spheres subjected to a uniform internal pressure. Numerical examples demonstrate a considerable deviation of stress distribution from linear theory, especially at the boundary, so that the decrease of stress maximum known in technical practice can be explained by small deviations from linearity. 相似文献
3.
Dr.-Ing. F. Jindra 《Archive of Applied Mechanics (Ingenieur Archiv)》1955,23(5):373-378
Ohne Zusammenfassung 相似文献
4.
Toshihiko Kuwabara Yutaka Kumano Jindra Ziegelheim Ikuya Kurosaki 《International Journal of Plasticity》2009,25(9):1759-1776
In-plane tension and compression experiments on copper alloy sheets (phosphor bronze) and 6000 series aluminum alloy sheets (AA6016-T4) were conducted using a specially designed testing apparatus. The apparatus is equipped with comb-type dies so that stress–strain curves of a sheet specimen subjected to tension followed by compression, and vice versa, can be measured without buckling of the specimen, as well as those for monotonic tension and compression. A difference was observed in the flow stresses between tension and compression for the as-received copper alloy, but not for the aluminum alloy. Moreover, stress reversal tests, such as tension followed by compression and compression followed by tension, were carried out in order to measure the Bauschinger effect. In the second part of the experiment, bending moment–curvature diagrams were measured for the as-received and pre-stretched specimens. The bending moment–curvature diagrams were compared with those calculated using the stress–strain curves obtained from the tension–compression tests, and were in good agreement with those calculated with the tension–compression asymmetry and the Bauschinger effect correctly reproduced. 相似文献
5.
6.
Daniel Schrer Vladimir Jindra Alain O. Bringhen Ulrich Burger 《Helvetica chimica acta》1991,74(8):1817-1822
The synthesis of N,N-dimethyl-N-[(pyrro-1-yl)methyl]anilinium chloride ( 14 ) and of the corresponding p-toluidinium salt 15 is described. These salts, when dissolved in polar solvents, are shown to be in equilibrium with 1-(chloromethyl)pyrrole ( 17 ) and thereby potentially with the 5-azoniafulvene ion ( 2 ). Consequently, they react under very mild conditions (MeCN, 60°) with enamines to give pyrrolizine derivatives in acceptable yield (40–50°). The process is rationalized in terms of an initial Mannich-type reaction which is immediately followed by acyclization. 相似文献
7.
Emil Cherbuliez Br. Baehler O. Espejo H. Jindra B. Willhalm J. Rabinowitz 《Helvetica chimica acta》1967,50(1):331-346
3-Aminopropanol reacts with aryl(or aralkyl or alkyl)isothiocyanates R? N?C?S to yield the corresponding thio-ureas R? NH? CS? NH? (CH2)3OH which, refluxed with hydrochloric acid, are cyclized by elimination of water. The cyclization products are identical with the hydrothiazines resulting by elimination of sulfate or phosphate from the sulfuric or phosphoric monoesters of these thio-ureas. The resulting hydrothiazines are either 2-(R-imino)-tetrahydro-m-thiazines (I) or 2-(R-amino)-dihydro-Δ2-m-thiazines (II). Their structure has been established by comparison of their spectra with those of model compounds in one of which the C?N double bond is certainly endocyclic (2-methyl-dihydro-Δ2-m-thiazine), the other presenting an exocyclic C?N double bond (3-methyl-2-phenylimino-tetrahydro-m-thiazine). When R is an aryl group, the C?N double bond is exocyclic (structure I with >C?N? Ar), and one may presume that this structure is stabilized by resonance. When R is an aralkyl or an alkyl group, the C?N double bond is endocyclic (structure II). The nmr spectra were taken with three types of solvent: CDCl3 or CCl4; (CD3)2SO; CF3COOH. In CF3COOH solution the benzylic protons of the hydrothiazine with R = pF? C6H4CH2? couple with NH (J=5,5cps) which confirms the endocyclic position of the C?N double bond in this case. 相似文献
8.
Dr.-Ing. F. Jindra 《Archive of Applied Mechanics (Ingenieur Archiv)》1955,23(2):122-129
Ohne ZusammenfassungZum Schluß danke ich Herrn Prof. R. Grammel sowie der Deutschen Forschungsgemeinschaft für die Möglichkeit, diese Untersuchung durchführen zu können. 相似文献
9.
The author grew CdS single crystals by his own method which is described here in addition to other methods. The material was either prepared by the author or commercial luminescence-pure material was used. The amount of impurities in the commercial material was an order higher than in the author's own material. It was found that the physical properties (e.g. hole density) are worse in large single crystals than in crystals with a mosaic structure. For this reason it is thought that some of the properties are caused by stoichiometric deviations and other by defects in the crystal lattice. In this case impurification plays only a secondary role. 相似文献
10.
This paper deals with two (main) problems of specific gold etching from parts of industrial equipment (e.g., supporting inserts
into chambers for physical or chemical vapor deposition). First part of the paper is focused on selective etching of gold
from aluminum substrates. Selectivity of the reaction, i.e. leaving substrates intact, is crucial. For this reason, the environmentally
friendly and safe method of etching gold in a thiourea solution was tested. This method, while well described in literature,
does not preserve various substrates (e.g., aluminum, stainless steel). The main goal of this part of the paper was to understand
the mechanism of the reaction and to improve the reaction selectivity towards the aluminum alloy substrate. Thus, different
acidifying agents were tested. Second part of the paper is focused on recovery (reduction) of gold from thiourea solutions.
Chemical, electrochemical, and biological reduction were tested for gold recovery. 相似文献