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排序方式: 共有173条查询结果,搜索用时 15 毫秒
111.
Phytosulfokine-alpha, a sulfated pentapeptide growth factor universally found in both monocotyledons and dicotyledons, strongly promotes proliferation of plant cells in culture. It is similar to animal polypeptide hormones in that it is processed from a larger precursor, preprophytosulfokine, although the putative processing sites do not conform to consensus sequences for endoproteolytic processing sites flanking animal prohormones. Like the animal preprohormones, preprophytosulfokine also has a signal peptide at the N-terminus for targeting to secretory pathways. The preprophytosulfokine gene has been confirmed to be expressed in vivo as well as in vitro. 相似文献
112.
A rapid and efficient system for Agrobacterium infection-mediated transient gene expression in rice has been developed. Using this system, transient expression of preprophytosulfokine, a precursor of phytosulfokine-a, encoded by OsPSK gene was analyzed. The results suggest that the Agrobacterium infection-mediated transient gene expression system is as efficient in rice Oc cells as in tobacco BY-2 cells and might be useful for rapid analysis not only of foreign gene expression, but also of antisense gene suppression. 相似文献
113.
A secreted peptide growth factor, phytosulfokine, acting as a stimulatory factor of carrot somatic embryo formation 总被引:10,自引:0,他引:10
Hanai H Matsuno T Yamamoto M Matsubayashi Y Kobayashi T Kamada H Sakagami Y 《Plant & cell physiology》2000,41(1):27-32
Somatic embryogenesis of the carrot (Daucus carota L.) depends on a set of factors, some of which accumulate in culture medium (conditioned medium, CM). When embryogenic cell clusters were transferred to an embryo-inducing medium, addition of CM derived from somatic embryo culture markedly stimulated somatic embryo formation. The active principles were purified using a simple bioassay system and identified to be phytosulfokines (PSKs), sulfated oligopeptide growth factors originally isolated from a CM derived from asparagus (Asparagus officinalis L.) mesophyll culture. Quantification studies using a competition ELISA system employing an anti-PSK-alpha polyclonal antibody showed that PSK production might be related to growth of cells, rather than development of somatic embryos. Thus the stimulatory effect of PSK on somatic embryo formation might be due to promotion of cell proliferation. 相似文献
114.
Phytosulphokine-{alpha}, a peptidyl plant growth factor, stimulates somatic embryogenesis in carrot 总被引:1,自引:0,他引:1
Kobayashi T; Eun C; Hanai H; Matsubayashi Y; Sakagami Y; Kamada H 《Journal of experimental botany》1999,50(336):1123-1128
Phytosulphokine- (PSK-) is the first chemically characterized peptide
that acts as a plant growth factor. It stimulates the proliferation of
asparagus and rice cells, but no information is yet available on its
effects on plant morphogenesis. The effects of PSK- on somatic
embryogenesis in carrot (Daucus carota L.) were
examined. PSK-, when added to the induction medium for somatic
embryogenesis, increased the number of somatic embryos. The chemical
analogues [2-5]PSK- and tyrosine sulphate ester (Tyr-SO3 H), which
have been used as negative controls in other systems, had no effect.
Moreover the proliferation of cells during somatic embryogenesis was also
enhanced by PSK- these results indicate that PSK-
enhanced cell division and, as a consequence, stimulated carrot somatic
embryogenesis. PSK- also stimulated the proliferation of
embryogenic cells in medium that contained 2,4-dichlorophenoxyacetic acid
(2,4-D), in which somatic embryos did not form, as well as the
proliferation of non-embryogenic cells (cells that had lost the ability to
form somatic embryos) in medium without 2,4-D. These results indicate that
PSK- has a stimulatory effect on cell division generally in carrot
cell cultures.Key words: Daucus carota, plant growth
factor, somatic embryogenesis, sulphated peptide.
相似文献
115.
Yamakawa S Matsubayashi Y Sakagami Y Kamada H Satoh S 《Bioscience, biotechnology, and biochemistry》1999,63(12):2240-2243
In order to investigate the function of the peptidyl plant growth factor, phytosulfokine-alpha (PSK-alpha), in plants, we examined the effect of PSK-alpha on the growth and chlorophyll content of Arabidopsis seedlings under high night-time temperature conditions. Although exposure to high night-time temperatures markedly reduced the fresh weight and chlorophyll content of the seedlings, these parameters in the plants supplied with PSK-alpha remained at the same levels as those of non-treated controls. These effects were not apparent when [2-5]PSK, Tyr-SO3H and kinetin were similarly supplied. The results suggest that PSK-alpha not only promotes cell proliferation, but may aid plants in their tolerance of heat stress. 相似文献
116.
A system of predicting the time of parturition in the chimpanzee was developed to assure care of the newborn as soon as possible after delivery. To quantify activity, the number of times that a parturient chimpanzee crossed a sensor marker of a TV monitor was recorded by a videosensor on the market for crime prevention. The amount of activity increased remarkably just prior to parturition. A system using a personal pocket alarm ("beeper"), which rang automatically when the number of crossings by the chimpanzee exceeded a selected level within a certain period of time, was tested. In the present study, the threshold for sounding the alarm was set at 50 crossings within 10 minutes. As a result, the pocket alarm began to ring at about 40 minutes before parturition. This enabled us to be present at parturition and to tend to a newborn abandoned by its mother in one case. The present system could be useful to predict the time of parturition in the chimpanzee. 相似文献
117.
Purification of chloroplast elongation factor Tu and cDNA analysis in tobacco: the existence of two chloroplast elongation factor Tu species 总被引:3,自引:0,他引:3
Yuhko Murayama Tohru Matsubayashi Mamoru Sugita Masahiro Sugiura 《Plant molecular biology》1993,22(5):767-774
We have purified a chloroplast elongation factor Tu (EF-Tu) from tobacco (Nicotiana tabacum) and determined its N-terminal amino acid sequence. Two distinct cDNAs encoding EF-Tu were isolated from a leaf cDNA library of N. sylvestris (the female progenitor of N. tabacum) using an oligonucleotide probe based on the EF-Tu protein sequence. The cDNA sequence and genomic Southern analyses revealed that tobacco chloroplast EF-Tu is encoded by two distinct genes in the nuclear genome of N. sylvestris. We designated the corresponding gene products EF-Tu A and B. The mature polypeptides of EF-Tu A and B are 408 amino acids long and share 95.3% amino acid identity. They show 75–78% amino acid identity with cyanobacterial and chloroplast-encoded EF-Tu species. 相似文献
118.
119.
Shuji Kitagawa Masako Matsubayashi Kazuo Kotani Koji Usui Fujio Kametani 《The Journal of membrane biology》1991,119(3):221-227
Summary Membrane fluidity of bovine platelets was examined with diphenylhexatriene (DPH), its cationic trimethylammonium derivative (TMA-DPH) and anionic propionic acid derivative (DPH-PA). After addition of these probes to platelet suspensions at 37°C, the fluorescence intensity of DPH-PA reached equilibrium within 2 min, whereas those of DPH and TMA-DPH increased gradually. With increase in the fluorescence intensity of TMA-DPH, its fluorescence anisotropy decreased significantly, but the fluorescence anisotropies of DPH-PA and DPH did not change during incubation. The gradual increase of fluorescence intensity of TMA-DPH was due to its penetration into the cytoplasmic side of the platelet membrane, as shown quantitatively by monitoring decrease in its extractability with albumin. Transbilayer movement of TMA-DPH was markedly temperature-dependent, and was scarcely observed at 15°C. The fluorescence intensity of TMA-DPH was much higher in platelet membranes and vesicles of extracted membrane lipids than the initial intensity in intact platelets. Moreover, the fluorescence anisotropy of TMA-DPH was much lower in the former preparations than the initial value in intact platelets. These results suggest that binding sites for TMA-DPH in the cytoplasmic side of the platelet membrane are more fluid than those in the outer leaflet of the plasma membrane. Platelet activation by ionomycin induced specific change in the fluorescence properties of TMA-DPH without causing transbilayer incorporation of the probe. 相似文献
120.