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71.
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   
72.
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   
73.
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   
74.
75.
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   
76.
邹钟琳 《昆虫学报》1953,(1):219-223
本文所记两种天牛,在幼虫时期,生活于土内,啮食植物根部,成虫于5,6月间之雨后,出土面交尾产卵。  相似文献   
77.
The formation of native insulin either from scrambled insulin or from the separated A chain and B chain S-sulphonates by protein disulphide-isomerase was demonstrated with yields of 20-30% as measured by h.p.l.c. analysis, receptor binding and stimulation of lipogenesis. The h.p.l.c. profile of the reaction products shows that, among all the possible isomers containing both chains, the native hormone is by far the predominating product and consequently the most stable under certain conditions.  相似文献   
78.
It has been shown that the active dicyano derivative of creatine kinase (ATP:creatine N-phosphotransferase) obtained by cyanolysis of the 5,5'-dithiobis(2-nitrobenzoic acid)-modified and inactivated enzyme contains, as does the native enzyme, two reactive SH groups. Modification of these two SH groups leads to complete inactivation of the dicyano enzyme. Reaction with 4-iodoacetamido-1-naphthol introduces fluorescent labels at these reactive SH groups of the native and the dicyano enzymes. Following tryptic digestion, the respective fluorescent-labelled peptides have been separated by HPLC and the amino acid composition analysis of these peptides has shown that they are consistent with the sequence of the peptide segment containing the active-site SH of Cys-282 of creatine kinase for both the native and the dicyano enzymes, showing that the active SH groups are free in the dicyano enzyme. Upon mild denaturation in 3 M urea, it can be shown that two of the SH groups partially buried in the native enzyme have been cyanylated in the dicyano enzyme. The two reactive SH groups are therefore essential for the activity of creatine kinase and the two cyanylated SH groups are internal groups which probably contributes partially to the stabilization of an active conformation of the enzyme molecule.  相似文献   
79.
Treatment of human promyelocytic leukemia cells U937 with phorbol 12-myristate 13-acetate (TPA) induces them to differentiate into monocytic cells [Harris, P., & Ralph, P. (1985) J. Leukocyte Biol. 37, 407-422]. Here we investigated the effects of TPA on interleukin 1 gene expression and the possible role of protein kinase C (PKC) in this process. Addition of TPA to serum-starved U937 cells induced the expression of the interleukin 1 beta (IL-1 beta) gene. This effect was apparent as early as 2 h and peaked at 24 h in the presence of 5 X 10(-8) M TPA. Higher concentrations of TPA, which partially or totally depleted protein kinase C levels in the cells (10(-9)-2 X 10(-5) M), had an inhibitory effect on IL-1 beta mRNA expression. Cell-permeable 1,2-dioctanoyl-sn-glycerol (diC8), a diacylglycerol that activates PKC in intact cells and cell-free systems, did not mimic the effect of TPA on the IL-1 beta mRNA induction. To determine the protein kinase C isozymes present in the control and TPA- (5 X 10(-8) M) treated U937 cells, we prepared antipeptide antibodies that specifically recognize the alpha, beta, and gamma isoforms of protein kinase C in rat brain cytosol and U937 cell extracts. In "control" U937 cells, 30% of PKC alpha was particulate, and PKC beta was cytosolic, while there was no detectable PKC gamma.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
80.
A series of 5-ureidobenzofuranones was discovered as potent and selective inhibitors of mTOR with good cellular activity. Molecular modeling studies revealed several hydrogen bond interactions of the ureido group with the enzyme at the ATP-binding site. Furthermore, modeling showed that the ureido group is best situated at C-5 of the benzofuranone. Syntheses of 4-ureido and 5-ureidobenzofuranones are presented.  相似文献   
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