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991.
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993.
Xiaochan He Hongxing Xu Guanchun Gao Xiaojun Zhou Xusong Zheng Yujian Sun Yajun Yang Junce Tian Zhongxian Lu 《PloS one》2014,9(8)
In order to clarify the impacts of southern rice black-streaked dwarf virus (SRBSDV) infection on rice plants, rice planthoppers and natural enemies, differences in nutrients and volatile secondary metabolites between infected and healthy rice plants were examined. Furthermore, the impacts of virus-mediated changes in plants on the population growth of non-vector brown planthopper (BPH), Nilaparvata lugens, and the selectivity and parasitic capability of planthopper egg parasitoid Anagrus nilaparvatae were studied. The results showed that rice plants had no significant changes in amino acid and soluble sugar contents after SRBSDV infection, and SRBSDV-infected plants had no significant effect on population growth of non-vector BPH. A. nilaparvatae preferred BPH eggs both in infected and healthy rice plants, and tended to parasitize eggs on infected plants, but it had no significant preference for infected plants or healthy plants. GC-MS analysis showed that tridecylic aldehyde occurred only in rice plants infected with SRBSDV, whereas octanal, undecane, methyl salicylate and hexadecane occurred only in healthy rice plants. However, in tests of behavioral responses to these five volatile substances using a Y-tube olfactometer, A. nilaparvatae did not show obvious selectivity between single volatile substances at different concentrations and liquid paraffin in the control group. The parasitic capability of A. nilaparvatae did not differ between SRBSDV-infected plants and healthy plant seedlings. The results suggested that SRBSDV-infected plants have no significant impacts on the non-vector planthopper and its egg parasitoid, A. nilaparvatae. 相似文献
994.
Plant antioxidation system is composed of a series of complex mechanisms, in which many antioxidants including some special
proteins are involved. Dehydrins are a family of late embryogenesis abundant (LEA) proteins which usually accumulate in plants
during late embryogenesis or in response to environmental stresses. They were suggested to be associated with specific protective
functions in plant cells, such as preventing coagulation of macromolecules and maintaining integrity of crucial cell structures.
In recent years, many studies implied that dehydrins also play an antioxidative role to alleviate oxidative damage in stressed
plants. They were proposed to scavenge radicals directly and sequester metals which are sources for radical generation to
avoid the production of reactive oxygen species (ROS). In this paper, we will discuss the novel putative role of dehydrins
in plant antioxidation mechanisms and how dehydrins perform their antioxidative activity. 相似文献
995.
996.
997.
The P2X7 receptor exhibits significant allelic polymorphism in humans, with both loss and gain of function variants potentially impacting
on a variety of infectious and inflammatory disorders. At least five loss-of-function polymorphisms (G150R, R307Q, T357S,
E496A, and I568N) and two gain-of-function polymorphisms (H155Y and Q460R) have been identified and characterized to date.
In this study, we used RT-PCR cloning to isolate and characterize P2X7 cDNA clones from human PBMCs and THP-1 cells. A previously unreported variant with substitutions of V80M and A166G was identified.
When expressed in HEK293 cells, this variant exhibited heightened sensitivity to the P2X7 agonist (BzATP) relative to the most frequent allele, as shown by pore formation measured by fluorescent dye uptake into
cells. Mutational analyses showed that A166G alteration was critical for the gain-of-function change, while V80M was not.
Full-length variants with multiple previously identified nonsynonymous SNPs (H155Y, H270R, A348T, and E496A) were also identified.
Distinct functional phenotypes of the P2X7 variants or mutants constructed with multiple polymorphisms were observed. Gain-of-function variations (A166G or H155Y) could
not rescue the loss-of-function E496A polymorphism. Synergistic effects of the gain-of-function variations were also observed.
We also identified the A348T alteration as a weak gain-of-function variant. Thus, these results identify the new gain-of-function
variant A166G and demonstrate that multiple-gene polymorphisms contribute to functional phenotypes of the human P2X7 receptor. Furthermore, the results demonstrate that the C-terminal of the cysteine-rich domain 1 of P2X7 is critical for regulation of P2X7-mediated pore formation. 相似文献
998.
Rapid and reliable detection of 11 food-borne pathogens using thin-film biosensor chips 总被引:1,自引:0,他引:1
Sulan Bai Jinyi Zhao Yaochuan Zhang Wensheng Huang Shi Xu Haodong Chen Liu-Min Fan Ying Chen Xing Wang Deng 《Applied microbiology and biotechnology》2010,86(3):983-990
Traditional methods for identifying food-borne pathogens are time-consuming and laborious, so it is necessary to develop innovative
methods for the rapid identification of food-borne pathogens. Here, we report the development of silicon-based optical thin-film
biosensor chips for sensitive detection of 11 food-borne pathogens. Briefly, aldehyde-labeled probes were arrayed and covalently
attached to a hydrazine-derivatized chip surface, and then, biotinylated polymerase chain reaction (PCR) amplicons were hybridized
with the probes. After washing and brief incubation with an antibiotin immunoglobulin G–horseradish peroxidase conjugate and
a precipitable horseradish peroxidase substrate, biotinylated chains bound to the probes were visualized as a color change
on the chip surface (gold to blue/purple). Highly sensitive and accurate examination of PCR fragment targets can be completed
within 30 min. This assay is extremely robust, sensitive, specific, and economical and can be adapted to different throughputs.
Thus, a rapid, sensitive, and reliable technique for detecting 11 food-borne pathogens was successfully developed. 相似文献
999.
Donghai Peng Xiaohui Xu Weixing Ye Ziniu Yu Ming Sun 《Applied microbiology and biotechnology》2010,85(4):1033-1040
The interaction between Bacillus thuringiensis insecticidal crystal protein Cry1A and cadherin receptors in lepidopteran insects induces toxin oligomerization, which is
essential for membrane insertion and mediates Cry1A toxicity. It has been reported that Manduca sexta cadherin fragment CR12-MPED and Anopheles gambiae cadherin fragment CR11-MPED enhance the insecticidal activity of Cry1Ab and Cry4Ba to certain lepidopteran and dipteran larvae
species, respectively. This study reports that a Helicoverpa armigera cadherin fragment (HaCad1) containing its toxin binding region, expressed in Escherichia coli, enhanced Cry1Ac activity against H. armigera larvae. A binding assay showed that HaCad1 was able to bind to Cry1Ac in vitro and that this event did not block toxin binding
to the brush border membrane microvilli prepared from H. armigera. When the residues 1423GVLSLNFQ1430 were deleted from the fragment, the subsequent mutation peptide lost its ability to bind Cry1Ac and the toxicity enhancement
was also significantly reduced. Oligomerization tests showed that HaCad1 facilitates the formation of a 250-kDa oligomer of
Cry1Ac-activated toxin in the midgut fluid environment. Oligomer formation was dependent upon the toxin binding to HaCad1,
which was also necessary for the HaCad1-mediated enhancement effect. Our discovery reveals a novel strategy to enhance insecticidal
activity or to overcome the resistance of insects to B. thuringiensis toxin-based biopesticides and transgenic crops. 相似文献
1000.
Xiao Wu Hui Chen Jianguo Sun Ying Peng Yan Liang Guangji Wang Jizhou Wu Peng Zhang 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(23):2067-2071
We have developed and validated a sensitive liquid chromatography–electrospray ionization-mass spectrometric (LC–ESI-MS) method for the quantification of verticinone, a major active constituent from Fritillaria hupehensis Hsiao et KC Hsia., in rat plasma. Verticinone and the internal standard (IS), hupehenine, were extracted from plasma samples by a simple liquid–liquid extraction with ethyl acetate after being alkalified by 1 M ammonia hydroxide. Chromatographic separation was achieved on a C18 column using a gradient elution program with methanol and water as the mobile phase. The detection was performed by selected ion monitoring (SIM) mode via positive electrospray ionization (ESI) interface. The lower limit of quantification (LLOQ) was 0.1 ng/mL. The calibration curves were linear (r2 > 0.998) over the concentration range of 0.1–200 ng/mL. Within- and between-run precision was less than 6.5% and accuracy was within ±10.7%. The validated method was applied to the pharmacokinetic study of verticinone in rats after a single oral administration of 1 mg/kg. 相似文献