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991.
Zhao Shi-Yi Sun Yan Lai Zhuo-Sheng Nan Qing-Zhen Li Kang Zhang Zhen-Shu 《Molecular and cellular biochemistry》2009,325(1-2):179-185
Nucleotides and nucleosides represent an important and ubiquitous class of molecules that interact with specific receptors, regulate a variety of activities within the liver, and play a role in the pathogenesis of hepatic fibrosis. Ecto-nucleotide pyrophosphatase/phosphodiesterases (E-NPPs) are ecto-enzymes that are located on the cell surface. NPP1, NPP2, and NPP3 (abbreviated as NPP1–3 hereafter) have been implicated in the hydrolysis of nucleotides; together with other ecto-nucleotidases, they control the events induced by extracellular nucleotides. We have identified and compared the expression of E-NPP family members in two different phenotypes of the mouse hepatic stellate cell line (GRX). In quiescent-like hepatic stellate cells (HSCs), E-NPP activity was significantly higher, NPP2 mRNA expression decreased and NPP3 mRNA increased. The differential NPP activity and expression in two phenotypes of GRX cells suggests that they are involved in the regulation of extracellular nucleotide metabolism in HSCs. However, the role of E-NPPs in the liver remains to be clarified. 相似文献
992.
Hervé Rhinn Céline Largeau Pascal Bigey René Lai Kuen Magali Richard Daniel Scherman Virginie Escriou 《Biochimica et Biophysica Acta (BBA)/General Subjects》2009
Background
We recently reported an efficient formulation of siRNA targeting TNF-α, that was able to restore immunological balance in a mouse arthritis model following intravenous injection.Method
Since this efficient formulation included the pre association of siRNA with a DNA cargo, we decided to extensively characterise siRNA lipoplexes with or without DNA cargo, in order to better understand the DNA cargo enhancing effect.Results
We showed that addition of DNA cargo to siRNA lipoplexes led to specific gene extinction in vitro, using reduced siRNA concentration. This procedure is also applicable to other lipid vectors, like Lipofectamine or DMRIE-C. No structural modification could be observed in siRNA lipoplexes upon addition of DNA cargo using dynamic light scattering or transmission electronic microscopy. Nevertheless, we observed some slight differences, in the amount of lipid required to obtain neutrality of the complex and in stability of the complex towards incubation with heparan sulfate.Conclusions
These results suggest that the addition of DNA cargo to siRNA complexes is an easy procedure that leads to more efficient complexes to transfer siRNA at low concentration and in the presence of serum. 相似文献993.
Huang Huang Renping Qiao Deyao Zhao Tong Zhang Youxian Li Fan Yi Fangfang Lai Junmei Hong Xianfeng Ding Zhenjun Yang Lihe Zhang Quan Du Zicai Liang 《Nucleic acids research》2009,37(22):7560-7569
Silencing specificity is a critical issue in the therapeutic applications of siRNA, particularly in the treatment of single nucleotide polymorphism (SNP) diseases where discrimination against single nucleotide variation is demanded. However, no generally applicable guidelines are available for the design of such allele-specific siRNAs. In this paper, the issue was approached by using a reporter-based assay. With a panel of 20 siRNAs and 240 variously mismatched target reporters, we first demonstrated that the mismatches were discriminated in a position-dependent order, which was however independent of their sequence contexts using position 4th, 12th and 17th as examples. A general model was further built for mismatch discrimination at all positions using 230 additional reporter constructs specifically designed to contain mismatches distributed evenly along the target regions of different siRNAs. This model was successfully employed to design allele-specific siRNAs targeting disease-causing mutations of PIK3CA gene at two SNP sites. Furthermore, conformational distortion of siRNA-target duplex was observed to correlate with the compromise of gene silencing. In summary, these findings could dramatically simplify the design of allele-specific siRNAs and might also provide guide to increase the specificity of therapeutic siRNAs. 相似文献
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997.
Hsu-Feng Lu Jai-Sing Yang Kuang-Chi Lai Shu-Chun Hsu Shu-Ching Hsueh Yuan-Liang Chen Jo-Hua Chiang Chi-Cheng Lu Chyi Lo Mei-Due Yang Jing-Gung Chung 《Neurochemical research》2009,34(8):1491-1497
Curcumin is reported to be a potent inhibitor of the initiation and promotion of many cancer cells. We investigated to examine
whether or not curcumin induce DNA damage in mouse–rat hybrid retina ganglion cell line N18 cells. The Comet assay showed
that incubation of N18 cells with 10, 25 and 30 μM of curcumin led to a longer DNA migration smear (Comet tail). The DNA gel
electrophoresis showed that 20 μM of curcumin for 24 and 48 h treatment induced DNA damage and fragments in N18 cells. The
real time PCR analysis showed that 20 μM of curcumin for 48 h treatment decreased ATM, ATR, BRCA1, 14-3-3σ, DNA-PK and MGMT
mRNA, and ATM and MGMT mRNA expression were inhibited in a time-dependent manner. Our results indicate that curcumin caused
DNA damage and inhibited DNA repair genes which may be the factors for curcumin-inhibited cell growth.
H.-F. Lu and J.-S. Yang are contributed equally to this study. 相似文献
998.
Lai Hong Fu Yansong Miao Sze Wan Lo Tai Chi Seto Samuel S.M. Sun Zeng-Fu Xu Sabine Clemens Lorne A. Clarke Allison R. Kermode Liwen Jiang 《Plant science》2009,177(6):668-675
Lysosomal storage diseases (LSDs), that collectively represent over 50 disorders, are amenable to enzyme replacement therapies. However, the current methods used to commercially produce recombinant lysosomal enzymes for this purpose, most commonly Chinese Hamster Ovary cells and human fibroblasts, are prohibitively costly. Plant bioreactors hold great promise for economic production of functional human α-l-iduronidase (hIDUA; glycosaminoglycan α-l-iduronohydrolase; EC 3.2.1.76), the enzyme deficient in the human LSD, Mucopolysaccharidosis I. We have developed and tested an expression system using transgenic tobacco BY-2 cells to produce high amounts of active hIDUA. A plant signal peptide was essential for proper expression and secretion of the 78 kDa glycosylated hIDUA into the cultured media of transgenic BY-2 cells. The yield and activity of the secreted hIDUA from long-term cultures of transgenic BY-2 cell lines were as high as 10 μg/mL media and 53,000 pmol/min/mg proteins, respectively. Thus, this transgenic BY-2 cell line presents an attractive platform for economic production and easy downstream purification of hIDUA for enzyme replacement therapy. Furthermore, this system can be used for the production and purification of other human lysosomal enzymes or pharmaceuticals. 相似文献
999.
Sunil S. Adav Duu-Jong Lee Juin-Yih Lai 《Applied microbiology and biotechnology》2009,84(6):1181-1189
Efficient nitrification and denitrification of wastewater containing 1,700 mgl−1 of ammonium-nitrogen was achieved using aerobic granular sludge cultivated at medium-to-high organic loading rates. The cultivated
granules were tested in a sequencing batch reactor (SBR) fed with 6.4 or 10.2 kg NH4+-N m−3 day−1, a loading significantly higher than that reported in literature. With alternating 2 h oxic and 2 h anoxic operation (OA)
modes, removal rate was 45.5 mg NH4+-N g−1 volatile suspended solids−1 h−1 at 6.4 kg NH4+-N m−3 day−1 loading and 41.3 ± 2.0 at 10.2 kg NH4+-N m−3 day−1 loading. Following the 60 days SBR test, granules were intact. The fluorescence in situ hybridization and confocal laser
scanning microscopy results indicate that the SBR-OA granules have a distribution with nitrifers outside and heterotrophs
outside that can effectively expose functional strains to surrounding substrates at high concentrations with minimal mass
transfer limit. This microbial alignment combined with the smooth granule surface achieved nitrification–denitrification of
wastewaters containing high-strength ammonium using aerobic granules. Conversely, the SBR continuous aeration mode yielded
a distribution with nitrifers outside and heterotrophs inside with an unsatisfactory denitrification rate and floating granules
as gas likely accumulated deep in the granules. 相似文献
1000.
Yuan Lu Hongxin Zhao Chong Zhang Qiheng Lai Xi Wu Xin-Hui Xing 《Biotechnology letters》2009,31(10):1525-1530
An expression system for NAD+-dependent formate dehydrogenase gene (fdh1), from Candida boidinii, was constructed and cloned into Enterobacter aerogenes IAM1183. With the fdh1 expression, the total H2 yield was attributed to a decrease in activity of the lactate pathway and an increase of the formate pathway flux due to
the NADH regeneration. Analysis of the redox state balance and ethanol-to-acetate ratio in the fdhl-expressed strain showed that increased reducing power arose from the reconstruction of NADH regeneration pathway from formate
thereby contributing to the improved H2 production. 相似文献