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991.
Kazuki Matsubara Eiji Yamamoto Nobuya Kobayashi Takuro Ishii Junichi Tanaka Hiroshi Tsunematsu Satoshi Yoshinaga Osamu Matsumura Jun-ichi Yonemaru Ritsuko Mizobuchi Toshio Yamamoto Hiroshi Kato Masahiro Yano 《PloS one》2016,11(3)
Biomass yield of rice (Oryza sativa L.) is an important breeding target, yet it is not easy to improve because the trait is complex and phenotyping is laborious. Using progeny derived from a cross between two high-yielding Japanese cultivars, we evaluated whether quantitative trait locus (QTL)-based selection can improve biomass yield. As a measure of biomass yield, we used plant weight (aboveground parts only), which included grain weight and stem and leaf weight. We measured these and related traits in recombinant inbred lines. Phenotypic values for these traits showed a continuous distribution with transgressive segregation, suggesting that selection can affect plant weight in the progeny. Four significant QTLs were mapped for plant weight, three for grain weight, and five for stem and leaf weight (at α = 0.05); some of them overlapped. Multiple regression analysis showed that about 43% of the phenotypic variance of plant weight was significantly explained (P < 0.0001) by six of the QTLs. From F2 plants derived from the same parental cross as the recombinant inbred lines, we divergently selected lines that carried alleles with positive or negative additive effects at these QTLs, and performed successive selfing. In the resulting F6 lines and parents, plant weight significantly differed among the genotypes (at α = 0.05). These results demonstrate that QTL-based selection is effective in improving rice biomass yield. 相似文献
992.
Naoki Watanabe Hiroshi Neda Yoshiki Ohtusuka Hisao Sone Naofumi Yamauchi Masahiro Maeda Hiroshi Kuriyama Yoshiro Niitsu 《Cancer immunology, immunotherapy : CII》1989,28(3):157-163
Summary Several aspects of the activity and effects of tumor necrosis factor (TNF) were investigated to gain further insight into its cytotoxic mechanism. The relation between number of TNF receptors and TNF susceptibility of both tumor cells and normal cells was studied, utilizing a specific binding assay. Among the tumor cells, a fairly close correlation (r=0.855) was observed between receptor number and sensitivity to TNF. No cytotoxic effect by TNF was observed on any of the normal cells tested, even though TNF receptors were shown to be present, and cell proliferation was apparently stimulated by TNF in some cases. TNF internalization and intracellular distribution were studied by pulse-labelling and Percoll density gradient centrifugation. In L-M (murine tumorigenic fibroblasts, highly sensitive to TNF cytotoxicity) cells and HEL (human embryonic lung cells, non-sensitive to TNF cytotoxicity) cells, receptor-bound 125I-labelled recombinant human TNF was rapidly internalized and delivered to lysosomes within 15–30 min, and this was followed by degradation and release into the culture medium. The presence of either a cytoskeletal disrupting agent or a lysosomotropic agent was observed to inhibit the cytotoxic effect of TNF, thus also indicating that TNF internalization, followed by delivery to lysosomes, is essential in the cytolytic mechanism of TNF.As observed by [3H]uridine incorporation, TNF did not affect RNA synthesis in L-R cells (TNF-resistant cell lines derived from L-M cells) and HEL cells, but markedly stimulated (by 3.5 times) RNA synthesis in L-M cells. 相似文献
993.
Asako Ando Jun Kawai Masahiro Maeda Kimiyoshi Tsuji John Trowsdale Hidetoshi Inoko 《Immunogenetics》1989,30(4):243-249
A genomic clone specifying a new HLA class II antigen β chain,DQB3, was isolated from a human genomic phage library using aDQB1 cDNA probe under low stringency conditions. Southern hybridization and nucleotide sequence analyses identified the β2 domain
exon (exon 3) with several deleterious mutations and the CP-TM-CY exon [connecting peptide, transmembrane, and cytoplasmic
regions, (exon 4)], but the first, second, and fifth exons encoding the 5′ UT-leader, the β1 domain, and the 3′ UT domain
of normal β chains, respectively, were entirely missing. The nucleotide sequences of these two exons were distinct from those
of other class II β chain genes, but slightly more related to theDQB1 andDQB2 genes than to other class II genes. TheDQB3 sequence mapped betweenDQA2 andDQB1, 15 kb upstream fromDQA2, by analysis of overlapping cosmid clones. This mapping was supported by the fact thatTaq I,Msp I, andBam HIDQB3 polymorphisms were perfectly correlated with theDQA2 polymorphism and not with any polymorphisms in theDR orDQ subregion, suggesting the presence of a hot spot for recombination betweenDQB3 andDQB1.
The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have
been assigned the accession number M26577. 相似文献
994.
Summary Short photoreceptor cells of the lamprey retina exhibited a 30% increase in the width of the myoid process and a 20% increase in that of the axonal process during a 12-h light period, compared to the measurements obtained during a 12-h dark period. An increase in the amount of cytoplasm, dilation of ER cisterns, and swelling of the nucleus appeared to cause the enlargement of the myoid parts. Accumulation of synaptic vesicles occurred concurrently with a thickening of the axonal process. These morphological changes presumably represent a phase of the diurnal cycle and current synaptic activity of the short cell. By contrast, the long photorecpetor cell showed neither measurable changes nor any indication of retinomotor movement. 相似文献
995.
Induced expression of a chimeric gene construct in transgenic lettuce plants using tobacco pathogenesis-related protein gene promoter region 总被引:3,自引:0,他引:3
The expression of a stress- and salicylic acidinducible protein gene from tobacco, PR1a protein gene, was determined after its Introduction to lettuce (Lactuca sativa L.) plants. The 5 flanking 2.4 Kb fragment from PR1a gene was joined to the bacterial -glucuronidase (GUS) gene (PR-GUS) and introduced into lettuce cotyledons by Agrobacterium-mediated gene transfer using a binary vector containing a kanamycin-resistance gene as a selectable marker. As a control with constitutive expression, the chimeric gene consisting of CaMV 35S RNA promoter and GUS gene (35S-GUS) was used. An improved method for shoot formation directly from lettuce cotyledons was used effectively for transformation, shortening the time for regeneration. In 70% or more of kanamycin-resistant regenerated lettuce plants, into which PR-GUS or 35S-GUS was introduced, high GUS activity and integration of the chimeric gene into the lettuce genome were detected. By treatment with salicylic acid, GUS activity increased 3- to 50-fold in PR-GUS transformants, however, no increase was detected in 35S-GUS plants. These results showed that the promoter of the stress-inducible tobacco PR1a protein gene was introduced into lettuce plants, and the introduced chimeric gene was expressed normally under the regulated control of the PRla promoter.Abbreviations BA
N6-benzyladenine
- GUS
-glucuronidase
- NAA
-naphthaleneacetic acid
- Km
kanamycin
- Kms
kanamycin resistant
- Km0
kanamycin sensitive
- NPT- II
neomycin phosphotransferase II
- PR
pathogenesis-related
- SA
salicylic acid
- MS
Murashige and Skoog medium
- NOS
nopaline synthase 相似文献
996.
997.
A new approach to the origin of the genetic code is proposed based on some regularities in the nucleotide distribution pattern of the code. The relative amounts of various amino acids in primitive proteins were possibly different from those in organisms living today. The primordial ratio was supposed to shift to the modern one guided by the action of primitive nucleotides. Each primitive tRNA had a discriminator site and, distinguished from it, an anticodon site. It is also postulated that primordially each amino acid could correspond to a wide variety of codons. During the course of the evolutionary change, a selective mechanism worked among the protobionts so that less frequent nucleotides became associated with more abundant amino acids in the primordial conditions, thus finally leading to the present codon catalogue.Presented at The International Seminar: The Origin of Life held in Moscow, August 2–7, 1974. 相似文献
998.
A moderately halophilic strain of Bacillus, isolated from unrefined solar salt, was capable of growth in the presence of 4 M NaCl. Maximal growth was obtained in a medium containing 1 to 2 M NaCl. The organism produced protease when cultivated aerobically in media containing 0 to 3 M NaCl or 0 to 2 M KCl. The protease activity was optimal at 0.5 M NaCl and 0.75 M KCl. 相似文献
999.
Molecular cloning and nucleotide sequence of the mutT mutator of Escherichia coli that causes A:T to C:G transversion 总被引:12,自引:0,他引:12
Masahiro Akiyama Takashi Horiuchi Mutsuo Sekiguchi 《Molecular & general genetics : MGG》1987,206(1):9-16
Summary The Escherichia coli mutator gene mutT, which causes A:TC:G transversion, was cloned in pBR 322. mutT
+ plasmids carry a 0.9 kb PvuII DNA fragment derived from the E. coli chromosome. Specific labelling of plasmid-encoded proteins by the maxicell method revealed that mutT codes for a polypeptide of about 15,000 daltons. The protein was overproduced when the mutT gene was placed under the control of the lac regulatory region on a multicopy runaway plasmid. The nucleotide sequence of the mutT gene was determined by the dideoxy method.Abbreviations Ap
ampicillin
- IPTG
isopropyl--d-thiogalactopyranoside
- kb
kilobase pair(s)
- kDa
kilodalton(s)
- SDS
sodium dodecyl sulphate
- Tc
tetracycline 相似文献