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881.
Jian Xiao Jia-Yao Hu Hao-Dong Sun Xiang Zhao Wan-Tong Zhong Dong-Zhu Duan Le Wang Xiao-Ling Wang 《Bioorganic & medicinal chemistry letters》2018,28(3):515-518
Four new diphenyl ether derivatives, sinopestalotiollides A–D (1–4), one new natural α-pyrone product (11), as well as twelve known compounds (5–1?7), were obtained from the ethyl acetate extract of the endophytic fungus Pestalotiopsis palmarum isolated from the leaves of medicinal plant Sinomenium acutum (Thunb.) Rehd et Wils. The structures were elucidated by HR-ESI-MS and NMR spectrometry data. Bioassay experiments revealed that compounds 1–4 and 11 exhibited strong to weak cytotoxicities against three human tumor cell lines Hela, HCT116 and A549. 相似文献
882.
Yongli Duan Shan Xu Hehua Xiong Linxiao Wang Bingbing Zhao Ping Wang Caolin Wang Yiqing Peng Shifan Cai Rong Luo Pengwu Zheng Qidong Tang 《Bioorganic & medicinal chemistry letters》2018,28(3):254-259
A series of 2-substituted-4-phenoxypyridine derivatives were designed, synthesized, and evaluated for their antiproliferative activity against 4 cancer cell lines (A549, HT-29, H460, and U87MG) in vitro. Most compounds showed moderate to excellent potency. Nine tyrosine kinases (c-Met, Flt-3, ALK, VEGFR-2, VEGFR-3, PDGFR-α, PDGFR-β, c-Kit, and EGFR) were used to evaluate the inhibitory activities with the most promising analogue 39, which showed the Flt-3/c-Met IC50 values of 2.18/2.61?nM. Structure-activity relationship studies indicated that n-Pr served as R1 group showed a higher preference, and stronger mono-EWGs on the phenyl ring (such as R2?=?4-F) was benefited to the potency. 相似文献
883.
Photosynthetica - The effects of calcium chloride solution (10 mmol L–1) on mesophyll cell ultrastructure, gas exchange, chlorophyll and carotenoid content, and PSII in tobacco leaf were... 相似文献
884.
Shen-Zhen Ren Zhong-Chang Wang Xiao-Hua Zhu Dan Zhu Zhang Li Fa-Qian Shen Yong-Tao Duan Han Cao Jing Zhao Hai-Liang Zhu 《Bioorganic & medicinal chemistry》2018,26(14):4264-4275
The overexpress of COX-2 was clearly associated with carcinogenesis and COX-2 as a possible target has long been exploited for cancer therapy. In this work, we described the design and synthesis of a series of diarylpyrazole derivatives integrating with chrysin. Among them, compound e9 exhibited the most potent inhibitory activity against COX-2 and antiproliferative activity against Hela cells with IC50 value of 1.12?μM. Further investigation revealed that e9 could induce apoptosis of Hela cells by mitochondrial depolarization and block the G1 phase of cell cycle in a dose-dependent manner. Besides, molecular docking simulation results was further confirmed that e9 could bind well with COX-2. In summary, compound e9 may be promising candidates for cancer therapy. 相似文献
885.
886.
Long‐distance dispersal or postglacial contraction? Insights into disjunction between Himalaya–Hengduan Mountains and Taiwan in a cold‐adapted herbaceous genus,Triplostegia 下载免费PDF全文
Yan‐Ting Niu Jian‐Fei Ye Jin‐Long Zhang Ji‐Zhong Wan Tuo Yang Xiao‐Xin Wei Li‐Min Lu Jian‐Hua Li Zhi‐Duan Chen 《Ecology and evolution》2018,8(2):1131-1146
Current disjunct patterns can result from long‐distance dispersal or postglacial contraction. We herein investigate the evolutionary history of Triplostegia to elucidate the disjunction between the Himalaya–Hengduan Mountain region (HHM) and Taiwan (TW). Genetic structure of Triplostegia was investigated for 48 populations using sequences from five chloroplast loci and the ribosomal nuclear internal transcribed spacer. Divergence time estimation, ancestral area reconstruction, and species distribution modeling (SDM) were employed to examine the biogeographic history of Triplostegia. Substantial genetic differentiation among populations from southwestern China (SW), Central China (CC), and TW was detected. Triplostegia was inferred to have originated in SW, and diversification began during the late Miocene; CC was colonized in the mid‐Pliocene, and TW was finally colonized in the early Pleistocene. SDM suggested an expansion of climatically suitable areas during the Last Glacial Maximum and range contraction during the Last interglacial in Triplostegia. Disjunction between HHM and TW in Triplostegia is most likely the consequence of topographic isolation and postglacial contraction. The potential climatic suitability areas for Triplostegia by 2070s (2061–2080) are predicted to slightly shrink and move northward. With continued global warming and human‐induced deforestation, extinction risk may increase for the cold‐adapted species, and appropriate strategies should be employed for ecosystem conservation. 相似文献
887.
A replication region from one of the Lactococcus lactis subsp. cremoris FG2 plasmids was isolated by cloning of a 4.8-kb XbaI fragment into a replication probe vector and transformation into L. lactis LM0230. A 1.8-kb region within this fragment was sequenced and confirmed by PCR subcloning to encode a functional replicon in LM0230. The replicon consists of an open reading frame encoding a putative replication protein (Rep) of 386 amino acids and a non-coding region (ori) which features several structural motifs typical of other known replication origins, including a 22-bp iteron sequence tandemly repeated three and a half times, a 10-bp direct repeat and two sets of inverted repeats. The ori region could drive replication of its plasmid when supplied with the replication region in-trans. The lack of detectable single-stranded DNA during replication and the existence of extensive homology with other known lactococcal theta replicons strongly suggest that this region encodes a theta-replicating mechanism. 相似文献
888.
A kinetic study of an immobilised lipase esterification reaction in dipropyl ether for resolution of ketoprofen indicated a Bi Bi Ping Pong mechanism with dead-end inhibition of the alcohol was occurring for both enantiomers and this is was confirmed experimentally. Parameters in the kinetic equation and reaction activation energies for the two enantiomers were determined by non-linear regression. 相似文献
889.
Kjell Andersson Chun-Mei Zhao Duan Chen Frank Sundler Rolf Håkanson 《Cell and tissue research》1996,286(3):375-384
The oxyntic mucosa of the mammalian stomach is rich in endocrine cells, such as ECL cells, A-like cells, somatostatin cells,
D1/P cells and, in some species, enterochromaffin cells. The various endocrine cell types can be distinguished on the basis
of their characteristic cytoplasmic granules and vesicles. The ECL cells contain numerous large secretory vesicles and relatively
few, small electron-dense granules and small clear microvesicles. We have suggested that in the rat the ECL cells contain
most of the gastric histamine with the secretory vesicles as the major histamine storage site in these cells. α-Fluoromethylhistidine
is an irreversible inhibitor of histidine decarboxylase, the histamine-forming enzyme. We have previously shown that this
enzyme inhibitor depletes histamine from the ECL cells in the rat and reduces the number of secretory vesicles in the cytoplasm.
In the present study, we have examined whether α-fluoromethylhistidine affects the ECL cells in other species and whether
it affects other types of endocrine cells in the oxyntic mucosa of the rat. Mice, rats and hamsters were treated with the
inhibitor (3 mg/kg per h) via minipumps subcutaneously for 24 h. This treatment lowered the oxyntic mucosal histamine concentration
by 65–90% and the number and volume density of the secretory vesicles by 85–95% in the ECL cells of the three species examined.
In contrast, the number and volume density of granules and microvesicles were not greatly affected. No evidence was found
for an effect of α-fluoromethylhistidine on A-like cells, somatostatin cells or D1/P cells of the rat stomach, suggesting that, unlike the ECL cells, they do not contain histamine.
Received: 18 January 1996 / Accepted: 23 May 1996 相似文献
890.
A new procedure for in vitro propagation of orchids belonging to the genus Phalaenopsis was developed. In contrast to commonly employed propagation methods that make use of leaf, root, or shoot tip tissues, we have used elongated stems of 6-benzyladenine-induced young seedlings as starting material for propagation. The elongated stem consisted of several nodes of which top nodes were used for cyclic propagation of new explants and the middle nodes for producing shoots or multiple adventitious buds. The whole procedure of proliferation could be completed within 7 months, and about 2,300 plantlets were produced from a single induced stem in a single year. This method may be used for propagation of seedlings in the case of lack of seeds in orchid breeding or for propagation of vegetative buds developed on flower stalks of rare orchid varieties when available flower stalks are limited. It may also have great potential for the propagation of wild threatened orchid species.Abbreviations PLB(s)
protocorm-like body(ies)
- zeatin
6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine
- 2ip
6-(,-dimethylallylamino)purine
- kinetin
6-furfurylaminopurine
- BA
6-benzyladenine 相似文献