排序方式: 共有111条查询结果,搜索用时 31 毫秒
51.
J. G. Byeon A. Ya. Kaplan S. F. Timashev G. V. Vstovskii B. W. Park 《Human physiology》2007,33(1):122-124
Quantitative analysis of changes in the autocorrelation structure of EEG short segments (in the range of several seconds) was performed in healthy adolescents (n = 39) and adolescents with schizophrenia spectrum disorders (n = 39). The variability of the EEG autocorrelation structure was shown to be higher in patients with the greatest trend in the frontal leads. It is suggested that psychopathology of the schizophrenia spectrum is accompanied by a break in the mutual determination of cortical neural networks with predominant localization of this process in the frontal areas of the brain cortex. 相似文献
52.
Mitochondrial DNA (mtDNA) from the bullhead torrent catfish, Liobagrus obesus, was isolated by long-polymerase chain reaction (Long-PCR) with universal primers and was fully sequenced by primer working using flanking sequences. The complete mtDNA from L. obesus was 16,531 bp in length and contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a control region, demonstrating a structure very similar to that of other bony fish. An analysis of the protein-coding genes revealed a statistically substantiated bias in (T+C): (A+G) content, supporting earlier findings regarding this peculiarity. As indicated by a chi-square test, the observed scores for pyrimidine and purine content were different from those expected assuming a 50:50 ratio: chi(2)=41.63, d.f.=5, p<0.000001 for three categories, including the 1st, 2nd, and 3rd codon positions. Further, there was a difference in nucleotide content between ND6 and the other 12 protein-coding genes in L. obesus. The values of p-distances, as summarized for different scales of evolutionary history at the Cyt b gene, revealed a clear pattern of increased nucleotide diversity at four levels: (1) intraspecies, (2) intragenus, (3) intrafamily, and (4) intraorder. Scores of average p-distances of the four categories in catfish were (1) 1.59+/-0.54%, (2) 5.28+/-1.72% (3) 16.37+/-1.26%, and (4) 19.81+/-0.14%, respectively. These data support the hypothesis that speciation in the order Siluriformes, in most cases, follows a geographic mode through the accumulation of a numerous small genetic changes over a long time period. A phylogenetic tree for the bullhead torrent catfish and several other fish species belonging to the order Siluriformes was developed on the basis of respective Cyt b sequences (1138 bp); the analysis revealed a monophyletic origin for the five examined families. A species-specific clustering of sequences from single species was obtained, supporting additionally basic phylogenetic information for the catfish and the barcoding suitability of Cyt b sequence data. Lastly, one of the well-supported properties of our phylogenetic tree (99% repetition level in our analysis) was the monophyletic placement of all catfish (order Siluriformes) among other ray-finned fish of the class Actinopterigii. Also discussed herein are the aspects of phylogeny based on the 16S rRNA gene. 相似文献
53.
54.
Jun Xi Chengcheng Piao Junseop Byeon Jungjin Yoon Zhaoxin Wu Mansoo Choi 《Liver Transplantation》2019,9(31)
As a promising alternative, inorganic perovskite nanocrystals allow reinforced stability of photovoltaic device. Unfortunately, directly assembling these nanocrystals into film is uncontrollable. Instead, in situ assembling technology under low temperature in open air is attractive but limited due to the tendency of nonperovskite transition. The adverse shell ligands and unstable core lattices are known as the fundamental problems. In order to address this issue, here proposed is a rational core–shell design: 1) with respect to ligands, a new one, 4‐fluorophenethylammonium iodide, is used to enhance bonding force and charge coupling between ligands and nanocrystals; 2) with respect to lattices, a novel compound H2PbI4 is employed to assist divalent ion (Mn2+) doping into perovskite lattices. By low temperature in situ processing CsPbI3 quasi‐nanocrystal film, the highest power conversion efficiency of 13.4% for p‐i‐n solar cells is achieved, which retains 92% after 500 h in ambient air. The current study underlines the significance of rational hierarchical design of inorganic perovskite nanocrystals, especially for low temperature in situ processable electronic devices. 相似文献
55.
Purpose
This study investigated the relationship between 2-year-old children’s exposure to TV and language delay.Methods
The subjects of this study were 1,778 toddlers (906 males and 872 females) who participated in the Panel Study on Korean Children conducted in 2010. The linguistic ability of the toddlers was measured with the K-ASQ (Korean-Ages and Stages Questionnaire). The relationship between the amount of young children’s exposure to TV and language delay was analyzed with Poisson regression.Results
The average daily TV watching time of 2-year-old Korean toddlers in this study was 1.21 hours. After all confounding variables were adjusted, toddlers with over 2 hours and less than 3 hours of TV watching time had 2.7 times more risk (RR = 2.74, 95% CI: 1.13–6.65) of language delay than those with less than 1 hour of TV watching time. Those with more than 3 hours of TV watching time had approximately 3 times (RR = 3.03, 95% CI: 1.12–8.21) more risk (p<0.05). In addition, the risk of language delay increased proportionately with the increase in toddlers’ TV watching time (p = 0.004).Conclusion
Two-year-old Korean toddlers’ average daily TV watching time of more than 2 hours was related with language delay. 相似文献56.
57.
58.
Baolei Jia Sangmin Lee Bang P. Pham Yoon Seung Cho Jae-Kyung Yang Hee-Seop Byeon Jong Cheol Kim Gang-Won Cheong 《Molecules and cells》2010,29(4):363-371
NADH oxidases (NOXs) catalyze the two-electron reduction of oxygen to H2O2 or four-electron reduction of oxygen to H2O. In this report, we show that an NADH oxidase from Thermococcus profundus (NOXtp) displays two forms: a native dimeric protein under physiological conditions and an oxidized hexameric form under
oxidative stress. Native NOXtp displays high NADH oxidase activity, and oxidized NOXtp can accelerate the aggregation of partially
unfolded proteins. The aggregates formed by NOXtp have characteristics similar to β-amyloid and Lewy bodies in neurodegenerative
diseases, including an increase of β-sheet content. Oxidized NOXtp can also bind nucleic acids and cause their degradation
by oxidizing NADH to produce H2O2. Furthermore, Escherichia coli cells expressing NOXtp are less viable than cells not expressing NOXtp after treatment with H2O2. As NOXtp shares similar features with eukaryotic cell death isozymes and life may have originated from hyperthermophiles,
we suggest that NOXtp may be an ancestor of cell death proteins. 相似文献
59.
60.
M. S. Byeon J. Y. Park S. W. Yoon H. W. Kang 《Zeitschrift fur angewandte Ichthyologie》2011,27(1):67-72
The histological structure and development of spines on the skin surface of Takifugu obscurus were studied during larval development conducted artificially with an average 30‰ salinity and 18.0–20.3°C water temperature. The epidermis comprises an outermost layer, middle layer, and the stratum germinativum, and contains three types of gland cells: small spherical or flask‐shaped mucous cells, larger sacciform mucous cells, and large granular cells. The dermis and subcutis follow. The spines first appear over the ventral region at 10 days after hatching and consist of two parts: a central long tapering portion which projects into the epidermis and eventually outside of the body, and a short supporting basal portion that is embedded within the stratum compactum layer of the dermis. The central, long tapering portion has two very short processes on top until 25 days after hatching, but these two separate spines fuse into one 30 days after hatching. In contrast, the short supporting spines rooted at the base consist of three to six small spines (usually four to five spines) and are present even in the adult stage. Therefore, calcareous spines consisting of one central long spine and three to six smaller supporting spines form tetra‐ and septaradiate spines (mainly penta‐ and hexaradiate). The spines first appear over the ventral region. 相似文献