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941.
Takashi Fujita Hitoshi Hatamoto Mari Miyamoto Taisuke Iwasaki Shin-ichi Takafuji 《Biotechnology letters》1998,20(11):1057-1061
Cell suspensions derived from Acer nikoense callus, not containing (S)-rhododendrol, converted 4-(p-hydroxyphenyl)-2- butanone into (R)-, (S)-rhododendrol and their glycosides. (R)- and (S)-rhododendrol formed was only detected in the culture medium and their glycosides only in the cells. The former compound disappeared within a short time and the latter one also tended to decrease during prolonged culture. Quantitative analysis of rhododendrol glycosides in the callus showed that most of them were (S)-rhododendrol 2-O--D-glucopyranoside and its content was much lower than that of the original plants. © Rapid Science Ltd. 1998 相似文献
942.
A mutation in theCENTRORADIALIS (CEN) gene ofAntirrhinum and in theTERMINAL FLOWER 1 (TFL1) gene ofArabidopsis causes their indeterminate inflorescence to determinate. We clonedCEN/TFL1 homologs fromNicotiana tabacum, the wild-type of which has a determinate inflorescence. TheCEN gene was expressed in the inflorescnece meristem and kept its inflorescence meristem identity, whereas the tobacco homolog
(NCH) was expressed at a low level throughout the plant’s development. AlthoughCEN andNCH are highly homologous genes, they may have been recruited to different developmental functions during their evolution. TwoNCH genes are derived from amphidiploidN. tabacum, but both of them hybridized with its diploid parents,N. sylvestris andN. tomentosiformis. Southern blotting, and the genomic organization ofTFL1 inArabidopsis revealed that anotherCEN homolog exists in the genome ofArabidopsis. These results suggest that there are two copies of theCEN homolog per diploid plant.
The extended abstract of a paper presented at the 13th International Symposium in Conjugation with Award of the International
Prize for Biology “Frontier of Plant Biology”
These two authors contributed to this work equally. 相似文献
943.
Takashi Araki Yasushi Kobayashi Hidetaka Kaya Masaki Iwabuchi 《Journal of plant research》1998,111(2):277-281
Transition from vegetative to reproductive development (flowering) is one of the most important decisions during the post-embryonic
development of flowering plants. More than twenty loci are known to regulate this process inArabidopsis. Some of these flowering-time genes may act at the shoot apical meristem to regulate its competence to respond to floral
inductive signals and floral evocation. Genetic and phenotypic analyses of mutants suggest that the late-flowering geneFT may be a good candidate for such genes. To test this, we have cloned theFT gene using aFT-deficiency line associated with a T-DNA insertion. Cloned genes and loss-of-function mutants in hand, it is now possible
to analyse the role ofFT and other genes in flowering at the biochemical and cellular levels as well as at the genetic level. The deduced FT protein
has homology with TFL1 and CEN proteins believed to be involved in regulation of inflorescence meristem identity. Phylogenetic
analysis suggests that theFT group and theTFL1/CEN group of genes diverged before the diversification of major angiosperm clades. This raises the interesting question of the
evolutionary relationship between the regulation of vegetative/reproductive switching in the shoot apical meristem and the
regulation of inflorescence architecture in angiosperms.
The extended abstract of a paper presented at the 13th International Symposium in Conjugation with Award of the International
Prize for Biology “Fronitier of Plant Biology” 相似文献
944.
Yasunori Machida Marina Nakashima Kayoko Morikiyo Hiroharu Banno Masaki Ishikawa Takashi Soyano Ryuichi Nishihama 《Journal of plant research》1998,111(2):243-246
The tobaccoNPK1 gene encodes a homolog of mitogenactivated protein kinase kinase kinases. We have recently identified tobacco kinesin-like
proteins (NACK1/2) as activators for NPK1. Immunochemical analyses of NPK1 and NACK1 proteins suggest that NPK1 is involved
in the regulation of some process in the M phase of the plant cell cycle.
The extended abstract of a paper presented at the 13th International Symposium in Conjugation with Award of the International
Prize for Biology “Frontier of Plant Biology” 相似文献
945.
Yosuke Andoh Takashi Kuramoto Norihide Yokoi Toshiro Maihara Kazuhiro Kitada Tadao Serikawa 《Mammalian genome》1998,9(4):287-293
To correlate rat genetic linkage maps with cytogenetic maps, we localized 25 new cosmid-derived simple sequence length polymorphism
(SSLP) markers and 14 existing genetic markers on cytogenetic bands of chromosomes, using fluorescence in situ hybridization
(FISH). Next, a total of 58 anchor loci, consisting of the 39 new and 19 previously reported ones, were integrated into the
genetic linkage maps. Since most of the new anchor loci were developed to be localized near the terminals of the genetic or
cytogenetic maps for each chromosome, the orientation and coverage of the whole genetic linkage maps were determined or confirmed
with respect to the cytogenetic maps. Thus, we provide here a new base for rat genetic maps.
Received: 9 September 1997 / Accepted: 11 November 1997 相似文献
946.
Toshikazu Ushijima Tomoko Nomoto Takashi Sugimura David E. Housman Minako Nagao 《Mammalian genome》1998,9(12):1008-1012
Mapping of genetic suppressors, modifiers, and quantitative trait loci (QTLs) requires genetic markers that can be efficiently
and inexpensively genotyped for a large number of individuals. To isolate rat genetic markers suitable for this purpose, representational
difference analysis (RDA) was performed with amplicons prepared by PCR with the B1 repetitive sequence used as the primer
(B1-amplicons). In total, 48 polymorphic DNA fragments were isolated by five series of RDA, subtracting the B1-amplicons prepared
from an ACI/N (ACI) rat from those prepared from BUF/Nac (BUF), and vice versa. All the polymorphic fragments detected ``presence-or-absence'
polymorphisms with B1-amplicons prepared from ACI, BUF, and their F2 progeny, and each fragment was linkage mapped. Dot-blotting amplicons onto filters at a high density and hybridization of
the filters with these B1-RDA markers made it possible to genotype a large number of rats simultaneously for multiple loci.
These B1-RDA markers were polymorphic between two given inbred strains of rat at frequencies between 30% and 70%. This is
the first report on the isolation of B1-RDA markers among inbred strains of rats.
Received: 15 July 1998 / Accepted: 18 August 1998 相似文献
947.
Timothy W. McNellis Mary Beth Mudgett Karen Li Takashi Aoyama Diana Horvath NamHai Chua Brian J. Staskawicz 《The Plant journal : for cell and molecular biology》1998,14(2):247-257
Pathogenic strains of Pseudomonas syringae pv. tomato carrying the avrRpt2 avirulence gene specifically induce a hypersensitive cell death response in Arabidopsis plants that contain the complementary RPS2 disease resistance gene. Transient expression of avrRpt2 in Arabidopsis plants having the RPS2 gene has been shown to induce hypersensitive cell death. In order to analyze the effects of conditional expression of avrRpt2 in Arabidopsis plants, transgenic lines were constructed that contained the avrRpt2 gene under the control of a tightly regulated, glucocorticoid-inducible promoter. Dexamethasone-induced expression of avrRpt2 in transgenic lines having the RPS2 gene resulted in a specific hypersensitive cell death response that resembled a Pseudomonas syringae-induced hypersensitive response and also induced the expression of a pathogenesis-related gene (PR1). Interestingly, high level expression of avrRpt2 in a mutant rps2–101C background resulted in plant stress and ultimately cell death, suggesting a possible role for avrRpt2 in Pseudomonas syringae virulence. Transgenic RPS2 and rps2 plants that contain the glucocorticoid-inducible avrRpt2 gene will provide a powerful new tool for the genetic, physiological, biochemical, and molecular dissection of an avirulence gene-specified cell death response in both resistant and susceptible plants. 相似文献
948.
Control of expression of a gene encoding an extensin by phytochrome and a blue light receptor in spores of
Adiantum capillus-veneris
L. 总被引:1,自引:1,他引:0
Kenko Uchida Takamichi Muramatsu Elisabeth Jamet Masaki Furuya 《The Plant journal : for cell and molecular biology》1998,15(6):813-819
In the present study, using a newly developed fluorescent differential display technique, we have carried out large-scale screening for genes whose expression was regulated by phytochrome and antagonistically by a blue light receptor in the spores of the fern Adiantum capillus-veneris L. Spores after imbibition were briefly irradiated with red, red/blue or blue light and collected 8 h after the irradiation. Total RNA was isolated from each sample and used to make cDNA with an oligo-dT primer. The cDNA was then used as a template for PCR with the oligo-dT primer and 80 arbitrary primers. The resulting PCR products were analyzed by an automated fluorescent DNA sequencer. Among 8000 displayed bands, we identified 15 upregulated and four down-regulated bands by red light, and this red light effect was irreversibly reversed by blue light. We cloned one of the up-regulated cDNA fragments and used it to screen a cDNA library prepared from the spores. The isolated insert is predicted to encode Ser-(Pro) n repeats and showed homology with cell wall-associated extensins. The expression of this cDNA was induced 8 h after a red light treatment and the red light induction was photoreversibly prevented by far-red light and photo-irreversibly by blue light. The mRNA of this gene was detectable 4 h after red light irradiation and gradually increased in germinating spores. 相似文献
949.
IL-12 and Viral Infections 总被引:2,自引:0,他引:2
Takashi Komastu Derek D. C. Ireland Carol Shoshkes Reiss 《Cytokine & growth factor reviews》1998,9(3-4):277-285
Interleukin-12 activates natural killer cells and promotes the differentiation of Th1 CD4+ cells; it is a critical factor in viral immunity. IL-12 is secreted by antigen presenting cells including dendritic cells, macrophages and astrocytes, both in tissues and in secondary lymphoid organs. Experimental studies have shown that administration of the cytokine rapidly activates both innate and specific immune responses; this results in enhanced host cellular responses and generally, promotes clearance of virus and host recovery from infection. The observations of many laboratories, studying viral immunity to both RNA and DNA based pathogens, are summarized. 相似文献
950.
Yasuyuki Ishibashi Takashi Saitoh Syuiti Abe Michihiro C. Yoshida 《Population Ecology》1998,40(1):51-59
Kinship amongClethrionomys rufocanus was investigated during the winter of 1992/93 in a 3-ha enclosure using both molecular and catch-mark-release techniques.
Forty-six adult voles (22 males and 24 females) having high heterozygosities, which were collected from several natural populations,
were released into the enclosure on 29 September 1992. Most fall-born individuals of both sexes stayed in their natal site
during the non-breeding period (December–March), although reproductively active females dispersed during the fall breeding
season (October–November). These philopatric individuals aggregated and formed an maternal family in the winter. Several females
which failed to reproduce were solitary during this season. Some individuals which were derived from several families also
aggregated into a mixed lineage group. Survival rate of fall-born voles from earlier litters was higher than that from later
ones. Maternal families broke up soon after the onset of spring reproduction. Most females established a territory near the
wintering site and made a kincluster, in which close relatives neighbored each other. Maternal families in winter bring about
female kin-clusters in spring, which may influence reproductive output in the breeding season. 相似文献