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Kochetov AV Titov SE Kolodiazhnaia IaS Komarova M Koval' VS Makarova NN Ilinskiĭ IuIu Trifonova EA Shumnyĭ VK 《Genetika》2004,40(2):282-285
The antisense suppressor was constructed for proline dehydrogenase gene (PDH; a fragment of PDH from Arabidopsis in antisense orientation and under the control of 35S promoter of cauliflower mosaic virus, CMV). In Nicotiana tabacum SR1 tobacco transformants bearing antisense suppressor for PDH, the proline content and the cytoplasm osmotic pressure were increased. The proline content in these transformants varied, whereas cytoplasm osmotic pressure was stable, which seems to reflect complicated relationships between these characteristics of the plant cell. 相似文献
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We have studied the influence of hydrogenation on the relative stability of the low-lying isomers of the anionic B7− cluster, computationally. It is known that the pure-boron B7− cluster has a doubly (σ- and π-) aromatic C6v (3A1) quasi-planar wheel-type triplet global minimum (structure 1), a low-lying σ-aromatic and π-antiaromatic quasi-planar singlet C2v (1A1) isomer 2 (0.7 kcal mol−1 above the global minimum), and a planar doubly (σ- and π-) antiaromatic C2v (1A1) isomer 3 (7.8 kcal mol−1 above the global minimum). However, upon hydrogenation, an inversion in the stability of the species occurs. The planar B7H2− (C2v, 1A1) isomer 4, originated from the addition of two hydrogen atoms to the doubly antiaromatic B7− isomer 3, becomes the global minimum structure. The second most stable B7H2− isomer 5, originated from the quasi-planar triplet wheel isomer 1 of B7−, was found to be 27 kcal mol−1 higher in energy. The inversion in stability occurs due to the loss of the doubly aromatic character in the wheel-type global minimum isomer (C6v, 3A1) of B7− upon H2−addition. In contrast, the planar isomer of B7− (C2v, 1A1) gains aromatic character upon addition of two hydrogen atoms, which makes it more stable.
Figure The B7H2-global minimum structure and its σ-aromatic and π-antiaromatic MOs
Dedicated to Professor Dr. Paul von Ragué Schleyer on the occasion of his 75th birthday. 相似文献
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Investigating the interactions between universal and culturally specific influences on color categorization across individuals and cultures has proven to be a challenge for human color categorization and naming research. The present article simulates the evolution of color lexicons to evaluate the role of two realistic constraints found in the human phenomenon: (i) heterogeneous observer populations and (ii) heterogeneous color stimuli. Such constraints, idealized and implemented as agent categorization and communication games, produce interesting and unexpected consequences for stable categorization solutions evolved and shared by agent populations. We find that the presence of a small fraction of color deficient agents in a population, or the presence of a “region of increased salience” in the color stimulus space, break rotational symmetry in population categorization solutions, and confine color category boundaries to a subset of available locations. Further, these heterogeneities, each in a different, predictable, way, might lead to a change of category number and size. In addition, the concurrent presence of both types of heterogeneity gives rise to novel constrained solutions which optimize the success rate of categorization and communication games. Implications of these agent-based results for psychological theories of color categorization and the evolution of color naming systems in human societies are discussed. 相似文献
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E. V. Suslov T. M. Khomenko I. V. Il’ina D. V. Korchagina N. I. Komarova K. P. Volcho N. F. Salakhutdinov 《Paleontological Journal》2006,40(4):S532-S537
It is shown that natural chiral catalysts, which could be formed e.g., from optically active amino acids on basic natural
minerals, could lead, at early stages of evolution, to the formation of rather complex optically active products from starting
achiral compounds. Using biomimetic combinations of vanadium ion complexes and chiral ligands synthesized from widely occurring
natural compounds, we created novel catalytic systems, permitting the transfer of optical activity in the course of catalytic
chemical transformations of achiral compounds. We found that in the presence of natural clay, optically active terpenoids
from the pinane series undergo multistage transformations, forming unexpected new products with preservation of optical purity. 相似文献
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L L Klimenko L V Kozlov L P Kudriashova O V Protasova I A Maksimova M N Komarova A A Konradov A A Turna E L Soiustova G N Matveev 《Biofizika》1999,44(1):128-131
The activity of serum complement proteins and the level of steady brain potential in patients with systemic lupus erythematosus and rheumatoid arthritis were determined. The statistical analysis indicated that there is a correlation between the parameters of the complement system and neurophysiological characteristics. The differences between rheumatoid arthritis and systemic lupus erythematosus are observed in the mean values of activity of complement proteins and the steady potential, their dispersions, and the structure of correlations between immunological and neurophysiological parameters. 相似文献