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71.
72.
Wissner A Brawner Floyd MB Rabindran SK Nilakantan R Greenberger LM Shen R Wang YF Tsou HR 《Bioorganic & medicinal chemistry letters》2002,12(20):2893-2897
The syntheses and biological evaluations of 4-anilinoquinoline-3-carbonitrile analogues of the three clinical lead 4-anilinoquinazolines Iressa, Tarceva, and CI-1033 are described. The EGFR and HER-2 kinase inhibitory activities and the cell growth inhibition of the two series are compared with each other and with the clinical lead EKB-569. Similar activities are observed between these two series. 相似文献
73.
Olendzenski L Liu L Zhaxybayeva O Murphey R Shin DG Gogarten JP 《Journal of molecular evolution》2000,51(6):587-599
Members of the Deinococcaceae (e.g., Thermus, Meiothermus, Deinococcus) contain A/V-ATPases typically found in Archaea or Eukaryotes which were probably acquired by horizontal gene transfer. Two methods were used to quantify the extent to which archaeal or eukaryotic genes have been acquired by this lineage. Screening of a Meiothermus ruber library with probes made against Thermoplasma acidophilum DNA yielded a number of clones which hybridized more strongly than background. One of these contained the prolyl tRNA synthetase (RS) gene. Phylogenetic analysis shows the M. ruber and D. radiodurans prolyl RS to be more closely related to archaeal and eukaryal forms of this gene than to the typical bacterial type. Using a bioinformatics approach, putative open reading frames (ORFs) from the prerelease version of the D. radiodurans genome were screened for genes more closely related to archaeal or eukaryotic genes. Putative ORFs were searched against representative genomes from each of the three domains using automated BLAST. ORFs showing the highest matches against archaeal and eukaryotic genes were collected and ranked. Among the top-ranked hits were the A/V-ATPase catalytic and noncatalytic subunits and the prolyl RS genes. Using phylogenetic methods, ORFs were analyzed and trees assessed for evidence of horizontal gene transfer. Of the 45 genes examined, 20 showed topologies in which D. radiodurans homologues clearly group with eukaryotic or archaeal homologues, and 17 additional trees were found to show probable evidence of horizontal gene transfer. Compared to the total number of ORFs in the genome, those that can be identified as having been acquired from Archaea or Eukaryotes are relatively few (approximately 1%), suggesting that interdomain transfer is rare. 相似文献
74.
Centrioles are self-reproducing organelles that form the core structure of centrosomes or microtubule-organizing centers (MTOCs). However, whether duplication and MTOC organization reflect innate activities of centrioles or activities acquired conditionally is unclear. In this paper, we show that newly formed full-length centrioles had no inherent capacity to duplicate or to organize pericentriolar material (PCM) but acquired both after mitosis through a Plk1-dependent modification that occurred in early mitosis. Modified centrioles initiated PCM recruitment in G1 and segregated equally in mitosis through association with spindle poles. Conversely, unmodified centrioles segregated randomly unless passively tethered to modified centrioles. Strikingly, duplication occurred only in centrioles that were both modified and disengaged, whereas unmodified centrioles, engaged or not, were "infertile," indicating that engagement specifically blocks modified centrioles from reduplication. These two requirements, centriole modification and disengagement, fully exclude unlimited duplication in one cell cycle. We thus uncovered a Plk1-dependent mechanism whereby duplication and segregation are coupled to maintain centriole homeostasis. 相似文献
75.
The TED (Technology, Entertainment, Design) Talks website hosts video recordings of various experts, celebrities, academics, and others who discuss their topics of expertise. Funded by advertising and members but provided free online, TED Talks have been viewed over a billion times and are a science communication phenomenon. Although the organization has been derided for its populist slant and emphasis on entertainment value, no previous research has assessed audience reactions in order to determine the degree to which presenter characteristics and platform affect the reception of a video. This article addresses this issue via a content analysis of comments left on both the TED website and the YouTube platform (on which TED Talks videos are also posted). It was found that commenters were more likely to discuss the characteristics of a presenter on YouTube, whereas commenters tended to engage with the talk content on the TED website. In addition, people tended to be more emotional when the speaker was a woman (by leaving comments that were either positive or negative). The results can inform future efforts to popularize science amongst the public, as well as to provide insights for those looking to disseminate information via Internet videos. 相似文献
76.
Chih-Hua Tsou 《Journal of plant research》1995,108(1):77-86
Anther and ovule development of the theaceous Ternstroemioideae is reported for the first time on the basis of eight specles
of three generaAdinandra, Cleyera andEurya. Anthers of these three genera are similar and can be characterized by the following traits: tapetum of glandular type, anther
dehiscing latrorse-introrse, both connective and anther epidermis heavily tanniniferous, and connective and even anther wall
layers having abundant druses. Their ovules are also very similar in being bitegmic and tenuinucellate, and in having a micropyle
formed by the inner integument only, three cell-layered integuments, a raphe bundle terminating at chalaza, usually amphitropous
or less often campylotropous ovule, embryo sac formation of Polygonum type, ephemeral antipodal cells, and tanniniferous ovule
epidermis. Such ovules are readily distinguishable from those of Camellioideae and all other families. It is suggested that
the three genera studied are closely related, and that the degree of embryological specialization is highest inAdinandra and lowest inEurya. On the basis of the significant embryological discrepacies, the Ternstroemioideae seem to have diverged rather distantly
from the other core-subfamily Camellioideae of the Theaceae. 相似文献
77.
Priming with live respiratory syncytial virus (RSV) prevents the enhanced pulmonary inflammatory response seen after RSV challenge in BALB/c mice immunized with formalin-inactivated RSV. 总被引:3,自引:0,他引:3 下载免费PDF全文
To investigate enhanced disease associated with a formalin-inactivated (FI) respiratory syncytial virus (RSV) vaccine, we studied the pulmonary inflammatory response to RSV in BALB/c mice immunized with live RSV, FI-RSV, or combinations of the two. After RSV challenge, the number of granular cells, the ratio of CD4+/CD8+ lymphocytes, and the level of Th2-like cytokine mRNAs in the bronchoalveolar lavage specimens in mice immunized first with live RSV and then with FI-RSV were lower than that in FI-RSV-immunized mice and close to that in live RSV-immunized mice. These data suggest that prior live RSV infection prevents most of the enhanced inflammatory response seen in FI-RSV-immunized mice and might explain lack of enhanced disease in older FI-RSV-immunized children. A live RSV vaccine might similarly decrease the risk of enhanced disease with non-live RSV vaccines. 相似文献
78.
The existing methods to solve the problems of pulsatile flow in the cardiovascular system are based on either linear axisymmetric
equations or non-linear one-dimensional equations. The solutions thus obtained give only a mediocre comparison with measurements.
In this paper, a non-linear axisymmetric theory is proposed. The starting point of the present theory is a third degree polynomial
representation of the velocity profile. Integral methods are then applied to obtain the governing equations.
To ascertain the accuracy of the theory proposed above, the calculations for a simple case involving pulsatile flow in a long
rigid tube were performed. The results are: (a) the average velocities compare very well with exact solutions and (b) the
velocity profiles for a given frequency agree very well with exact solutions for flow in small tubes, but tend to differ as
tube size is increased. 相似文献
79.
80.
In the succinate-cytochrome c reductase, the reduction of cytochrome b has been found to be triphasic: an initial rapid partial reduction was followed first by a rapid oxidation and then finally by a slow reduction. The initial reduction of cytochrome b was faster than that of cytochrome c1 and the final slow reduction of cytochrome b began when cytochrome c1 reduction was approaching completion. In presence of the inhibitors antimycin A or HQNO the reduction of cytochrome b became monophasic. Hysteresis or a kinetic cooperative effect of a factor controlling cytochrome b oxidation has been suggested as a possible explanation for the triphasic reduction of cytochrome b. 相似文献