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11.
J. Trémouillaux-Guiller H. Kodja J. C. Chénieux 《Plant Cell, Tissue and Organ Culture》1994,37(1):25-30
Protoplasts enzymatically isolated from cell line of Catharanthus roseus G. Don crown gall, were cultured at high density (105 P ml-1) in modified B5 liquid medium (Gamborg et al. 1976). In the absence of growth regulators C. roseus protoplasts were able to regenerate a cell-wall, divide and, subsequently, yield very numerous clones in the absence of growth regulators. After two weeks, the cultures were greatly diluted in order to obtain clones of single-cell origin. Most of the clones individually transferred onto solid medium can proliferate indefinitely, without growth regulators. Among analyzed clones, 90% were nopaline positive. Their ajmalicine and serpentine content was compared with that of the parental crown gall line, and was found to be low. The CR10 protoplasts were very easy to grow, they were an interesting model for the development of pure tumorous lines. Moreover, we found that the tumorous protoplasts were useful for cell fusion experiments or for the delicate culture of tree protoplasts.Abbreviations B5
Gamborg et al. (1976) medium
- 2,4-d
2,4-dichlorophenoxyacetic acid
- Kin
Kinetin
- NAA
naphthalene acetic acid
- BA
N6 (benzyl) adenine 相似文献
12.
Variation in tooth crown morphology plays a crucial role in species diagnoses, phylogenetic inference, and the reconstruction of the evolutionary history of the primate clade. While a growing number of studies have identified developmental mechanisms linked to tooth size and cusp patterning in mammalian crown morphology, it is unclear (1) to what degree these are applicable across primates and (2) which additional developmental mechanisms should be recognized as playing important roles in odontogenesis. From detailed observations of lower molar enamel–dentine junction morphology from taxa representing the major primate clades, we outline multiple phylogenetic and developmental components responsible for crown patterning, and formulate a tooth crown morphology framework for the holistic interpretation of primate crown morphology. We suggest that adopting this framework is crucial for the characterization of tooth morphology in studies of dental development, discrete trait analysis, and systematics. 相似文献
13.
14.
G. M. S. van Slogteren P. J. J. Hooykaas R. A. Schilperoort 《Plant molecular biology》1984,3(6):333-336
Summary A shooty tumor induced by a shooter mutant of an octopine strain of Agrobacterium tumefaciens was cloned. One clone obtained (TS038) behaved aberrantly in that it grew as a shooty tumor tissue on phytohormone free medium, but did not contain octopine synthase activity. In line TS038 the genes for octopine synthase and for the enzymes involved in agropine and mannopine synthesis were present, but were not transcribed. However, the above genes became active in TS038 tumor shoots after grafting as well as after treatment with the hypomethylating agent 5-azacytidine. After an unusually long incubation period in the growth cabinet shoot cultures appeared to have developed small shoots from the top of the leaves. This unusual form of differentiation was found to be accompanied by the induction of octopine synthase activity. 相似文献
15.
Plant tumor reversal associated with the loss of foreign DNA 总被引:1,自引:0,他引:1
Fun-Mei Yang Alice L. Montoya Eugene W. Nester Milton P. Gordon 《In vitro cellular & developmental biology. Plant》1980,16(1):87-92
Summary Transformation of plant tissues into crown gall tumors has been associated with the transfer of a portion of a tumor-inducing
plasmid (Ti-plasmid) into plant DNA. Various laboratories have regenerated normal-appearing plants from a number of crown
gall tumors. This study investigates the fate of the foreign DNA in a series of tissues derived from various parts of a plant
regenerated from the tumor BT-37 by Braun and his coworkers. It was found that all the foreign DNA sequences were lost from
tissues that had lost all their tumorous traits; whereas the plasmid DNA sequences were still present in tissues that appeared
normal but still exhibited tumorous traits when returned to tissue culture media. From these studies it would appear that
the presence of the Ti-plasmid sequences in the plant DNA is required for the maintenance of the transformed state.
Presented in the Symposium on Gene Transfer, Differentiation and Neoplasia in Plant and Animal Cells at the 30th Annual Meeting
of the Tissue Culture Association, Seattle, Washington, June 10–14, 1979. This symposium was supported in part by Grant CA
26748 from the National Cancer Institute, DHEW, and Grant RD-67 from the American Cancer Society. 相似文献
16.
Summary Three independently isolated tobacco crown gall strains incited byAgrobacterium tumefaciens C58 required phytohormone (auxin and cytokinin) supplements in the basal medium to grow, at 37°C. Six other tobacco crown
gall strains incited, respectively, byA. tumefaciens IIBV7, B6, CGIC, A6NC, 27 and AT4 expressed, at 37°C, the tumor characteristic of ability to grow in vitro on medium lacking
phytohormones. Nopaline was not detectable in C58 tumors cultured at 37°C, but octopine was produced by B6 tumor tissues incibated
at the elevated temperature. C58 tumor strains kept at 37°C for 1 week or more lost the ability to express tumor characteristics
at 27°C such as tissue morphology, growth on basal medium lacking phytohormones and nopaline production. Heat-treated C58
tissues also differed from the original tumor strain in regeneration ability and phytohormone requirements of explants; i.e.
explants from regenerated, heart-treated C58 tumors required both auxin and cytokinin for growth in vitro. 相似文献
17.
18.
《African Journal of Aquatic Science》2013,38(3):347-349
The southern African crab Hymenosoma orbiculare was recently split into five distinct species, of which three are estuarine/coastal and have peripatric distributions that are linked to temperature-defined marine bioregions. This suggests that the species’ ranges may be limited by physiological adaptations to their thermal environment. We explored this hypothesis by rearing the larvae of the warm-temperate lineage of H. orbiculare and the warm-temperate/subtropical H. longicrure at a range of water temperatures, and found clear temperature-dependent differences in the duration of larval development. Our study contributes to the growing body of evidence that stresses the importance of adaptation to regional environmental conditions, rather than physical dispersal barriers on their own, in limiting the mixing of marine species between temperature-defined biogeographic regions. 相似文献
19.
Li-Min Lu Hai-Hua Hu Dan-Xiao Peng Bing Liu Jian-Fei Ye Tuo Yang Hong-Lei Li Miao Sun Stephen A. Smith Pamela S. Soltis Douglas E. Soltis Zhi-Duan Chen 《Journal of Biogeography》2020,47(10):2286-2291
In response to our paper on the evolutionary history of the Chinese flora, Qian suggests that certain features of the divergence time estimation employed might have led to biased conclusions in Lu et al (2018). Here, we consider Qian's specific criticisms, explore the extent of uncertainty in the data and demonstrate that (i) no systematic bias toward dates that are too young or too old is detected in Lu et al.; (ii) constraint of the crown age of angiosperms does not bias the generic ages estimated by Lu et al.; and (iii) ages derived from the Chinese regional phylogeny do not bias the conclusions reported by Lu et al. All these analyses confirm that the conclusions reported previously are robust. We argue that, like many large-scale biodiversity analyses, sources of noise in divergence time estimation are to be expected, but these should not be confused with bias. 相似文献
20.