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排序方式: 共有457条查询结果,搜索用时 406 毫秒
1.
2.
The temporal correlates of evoked potentials from the visual and motor cortices in affective states]
K I Dudaeva L M Puchinskaia V N Krasnov 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1991,41(4):671-679
Peak latencies (PLs) of seven isopolar components of the evoked potentials (EPs) of the occipital and central areas in patients with different extent of depressions with the predominance of alarm or anguish affects were compared with healthy ones. In alarm affect the differences in PLs of EP components dominant in the occipital areas while in anguish affect they prevail in the central cortical zones. 相似文献
3.
Nielsen J; Peixoto AA; Piccin A; Costa R; Kyriacou CP; Chalmers D 《Molecular biology and evolution》1994,11(6):839-853
The region of the clock gene period (per) that encodes a repetitive tract
of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran
species both within and outside the Drosophilidae. All the non-
Drosophilidae sequences in this region are short and present a remarkably
stable picture compared to the Drosophilidae, in which the region is much
larger and extremely variable, both in size and composition. The
accelerated evolution in the repetitive region of the Drosophilidae appears
to be mainly due to an expansion of two ancestral repeats, one encoding a
Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and
asparagine or threonine. In some drosophilids the expansion involves a
duplication of the pentapeptide sequence, but in Drosophila pseudoobscura
both the dipeptide and the pentapeptide repeats are present in larger
numbers. In the nondrosophilids, however, the pentapeptide sequence is
represented by one copy and the dipeptide by two copies. These observations
fulfill some of the predictions of recent theoretical models that have
simulated the evolution of repetitive sequences.
相似文献
4.
Evolutionary origin of human and primate malarias: evidence from the circumsporozoite protein gene 总被引:8,自引:1,他引:7
We have analyzed the conserved regions of the gene coding for the
circumsporozoite protein (CSP) in 12 species of Plasmodium, the malaria
parasite. The closest evolutionary relative of P. falciparum, the agent of
malignant human malaria, is P. reichenowi, a chimpanzee parasite. This is
consistent with the hypothesis that P. falciparum is an ancient human
parasite, associated with humans since the divergence of the hominids from
their closest hominoid relatives. Three other human Plasmodium species are
each genetically indistinguishable from species parasitic to nonhuman
primates; that is, for the DNA sequences included in our analysis, the
differences between species are not greater than the differences between
strains of the human species. The human P. malariae is indistinguishable
from P. brasilianum, and P. vivax is indistinguishable from P. simium; P.
brasilianum and P. simium are parasitic to New World monkeys. The human P.
vivax-like is indistinguishable from P. simiovale, a parasite of Old World
macaques. We conjecture that P. malariae, P. vivax, and P. vivax-like are
evolutionarily recent human parasites, the first two at least acquired only
within the last several thousand years, and perhaps within the last few
hundred years, after the expansion of human populations in South America
following the European colonizations. We estimate the rate of evolution of
the conserved regions of the CSP gene as 2.46 x 10(-9) per site per year.
The divergence between the P. falciparum and P. reichenowi lineages is
accordingly dated 8.9 Myr ago. The divergence between the three lineages
leading to the human parasites is very ancient, about 100 Myr old between
P. malariae and P. vivax (and P. vivax-like) and about 165 Myr old between
P. falciparum and the other two.
相似文献
5.
Photosynthetic enhancement studies performed at 619 nm (excitation of Systems I and II) and at 446 nm (mainly excitation of System I) revealed an 18% photosynthetic enhancement simultaneously with a 31% reduction in glycolate excretion. This observation supports the hypothesis that some glycolate may be consumed in an oxidation process associated with System I when System II is poorly excited and the supply of electrons from the water splitting process of photosynthesis is low. 相似文献
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8.
Abramov I. S. Korneva Yu. S. Shisterova O. A. Ikonnikova A. Yu. Emelyanova M. A. Lisitsa T. S. Krasnov G. S. Nasedkina T. V. 《Molecular Biology》2021,55(3):354-362
Molecular Biology - Molecular profiling of tumors may provide promising options for personalized treatment. We have examined the spectrum of germline and somatic mutations in 23 breast cancers (BC)... 相似文献
9.
Kandarakov O. F. Demin A. M. Popenko V. I. Leonova O. G. Kopantseva E. E. Krasnov V. P. Belyavsky A. V. 《Molecular Biology》2020,54(1):99-110
Molecular Biology - The factors that affect the labeling of NIH 3T3 murine fibroblasts with Fe3O4-based magnetic nanoparticles (MNPs) were studied using MNPs produced by the gas condensation and... 相似文献
10.
Ghukasyan L. G. Krasnov G. S. Muravenko O. V. Ikonnikova A. Y. Yurasov R. A. Baidun L. V. Ibragimova S. Z. Nasedkina T. V. 《Molecular Biology》2020,54(3):341-348
Molecular Biology - Certain subtypes of acute myeloid leukemia occur as a result of the cooperation of several events these are, the formation of fusion genes as a result of chromosomal... 相似文献