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Andrew Teasdale Michael Jahn Simon Bailey Andrew Feilden Graham Taylor Marta L. Corcoran Robert Malick Dennis Jenke Cheryl L. M. Stults Lee M. Nagao 《AAPS PharmSciTech》2015,16(3):664-674
The effective management of leachables in pharmaceutical products is a critical aspect of their development. This can be facilitated if extractables information on the materials used in a packaging or delivery system is available to assist companies in selecting materials that will be compatible with the drug product formulation and suitable for the intended use. The Extractables and Leachables Safety Information Exchange (ELSIE) materials working group developed and executed a comprehensive extraction study protocol that included a number of extraction solvents, extraction techniques, and a variety of analytical techniques. This was performed on two test materials, polyethylene (PE) and polyvinyl chloride (PVC), that were selected due to their common use in pharmaceutical packaging. The purpose of the study was to investigate if the protocol could be simplified such that (i) a reduced number or even a single extraction technique could be used and (ii) a reduced number of solvents could be used to obtain information that is useful for material selection regardless of product type. Results indicate that, at least for the PVC, such reductions are feasible. Additionally, the studies indicate that levels of extractable elemental impurities in the two test materials were low and further confirm the importance of using orthogonal analytical detection techniques to gain adequate understanding of extraction profiles.KEY WORDS: extractables, extraction technique, polyethylene, polyvinyl chloride 相似文献
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Amino acid sequence of rubber elongation factor protein associated with rubber particles in Hevea latex 总被引:6,自引:0,他引:6
M S Dennis W J Henzel J Bell W Kohr D R Light 《The Journal of biological chemistry》1989,264(31):18618-18626
The amino acid sequence of rubber elongation factor, a recently discovered protein tightly bound to rubber particles isolated from the commercial rubber tree Hevea brasiliensis, is presented. The role of this protein in rubber elongation and its interaction with prenyltransferase and rubber particles have been discussed in the preceding paper in this series (Dennis, M. S., and Light, D. R. (1989) J. Biol. Chem. 264, 18608-18617). Trypsin, Staphylococcus protease, chymotrypsin, acetic acid, and hydroxylamine cleavage were used to generate peptide fragments that were isolated by reverse phase high pressure liquid chromatography and analyzed by amino acid composition and automated Edman degradation. Each digest contained one blocked peptide identified as the amino terminus. The blocked amino-terminal peptide from the tryptic digest was analyzed by amino acid composition, fast atom bombardment mass spectrometry (molecular ion 1659.9), subdigested with Staphylococcus protease for partial sequence analysis, and finally deblocked with bovine liver acyl-peptide hydrolase removing an acetylalanine to allow analysis by Edman degradation. Rubber elongation factor is 137 amino acids long, has a molecular mass of 14,600 daltons, and lacks four amino acids: cysteine, methionine, histidine, and tryptophan. The NH2 terminus is highly charged and contains only acidic residues (5 of the first 12 amino acids). The first four amino acids are highly represented in other known NH2-terminally acetylated proteins. Comparison of the sequence of rubber elongation factor with other known sequences does not reveal significant sequence similarities that would suggest an evolutionary relationship. 相似文献
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Richard P. Shefferson Tiiu Kull Michael J. Hutchings Marc‐André Selosse Hans Jacquemyn Kimberly M. Kellett Eric S. Menges Richard B. Primack Juha Tuomi Kirsi Alahuhta Sonja Hurskainen Helen M. Alexander Derek S. Anderson Rein Brys Emilia Brzosko Slavomir Dostálik Katharine Gregg Zdeněk Ipser Anne Jäkäläniemi Jana Jersáková W. Dean Kettle Melissa K. McCormick Ana Mendoza Michael T. Miller Asbjørn Moen Dag‐Inge Øien Ülle Püttsepp Mélanie Roy Nancy Sather Nina Sletvold Zuzana Štípková Kadri Tali Robert J. Warren II Dennis F. Whigham 《Ecology letters》2018,21(5):724-733
Vegetative dormancy, that is the temporary absence of aboveground growth for ≥ 1 year, is paradoxical, because plants cannot photosynthesise or flower during dormant periods. We test ecological and evolutionary hypotheses for its widespread persistence. We show that dormancy has evolved numerous times. Most species displaying dormancy exhibit life‐history costs of sprouting, and of dormancy. Short‐lived and mycoheterotrophic species have higher proportions of dormant plants than long‐lived species and species with other nutritional modes. Foliage loss is associated with higher future dormancy levels, suggesting that carbon limitation promotes dormancy. Maximum dormancy duration is shorter under higher precipitation and at higher latitudes, the latter suggesting an important role for competition or herbivory. Study length affects estimates of some demographic parameters. Our results identify life historical and environmental drivers of dormancy. We also highlight the evolutionary importance of the little understood costs of sprouting and growth, latitudinal stress gradients and mixed nutritional modes. 相似文献
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Roger L. H. Dennis Leonardo Dapporto Tim G. Shreeve Eddie John John G. Coutsis Otakar Kudrna Kimmo Saarinen Nils Ryrholm W. R. Williams 《Journal of Insect Conservation》2008,12(3-4):205-236
Depending on their faunal content islands can function as important ‘vehicles’ for conservation. In this study, we examine data on 440 butterfly species over 564 European islands in 10 island groups. To determine the status of the butterfly fauna, we have adopted two approaches, island-focused and species-focused, examined using principal components analysis and regression modelling. In the former, we relate species richness, rarity and endemicity to island geography (area, elevation, isolation and location in latitude and longitude); in the latter, species occurrence on islands is examined in relation to distribution, range, range boundaries, and altitudinal limits on the continent as well as species’ ecology (number of host plants) and morphology (wing expanse). Species on islands are also assessed for their status on the continental mainland, their distributional dynamics (extinctions, distribution changes) and conservation status (Red Data Book, European Habitat Directive, Species of European Conservation Concern and Bern Convention listing. Unexpectedly, we find that a large fraction of the European butterfly species is found on the islands (63.4%; 59% on small islands) comprising some 6.2% of the land area of Europe. Although species occurring on the islands tend, on the whole, to have lower conservation status and are not declining over Europe, 45 species are endemics restricted to the islands. Species richness shows only a weak locational pattern and is related as expected to isolation from the continental source and island area; but, both rarity and endemicity have distinctive geographical bias to southern Europe, on islands now under increasing pressure from climate change and increasingly intensive human exploitation. The vulnerability of species on islands is emphasised in the relationship of island occurrence (% occurrence and presence/absence of species on any island) with continental distributions. A large proportion of the variation (84%) is accounted by continental distribution, the southern range limit and lower altitudinal limit. Most species (69%) occur on very few islands (<5%). In view of ongoing species dynamics on islands, migrations and extinctions of species, island repositories of species depend in large part on conservation of butterflies at continental sources. The unique faunas and rare species on islands also depend on appropriate concern being given to the island faunas. Conservation of European islands is thus a two-way process, sustaining sources and conserving island refuges. Residuals from the regressions (islands with more or fewer species, rare and endemic species; species occurring more or less frequently than expected on islands) provide warning signals of regions and islands deserving immediate attention. 相似文献
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Désirée M van der Heijde Dennis A Revicki Katherine L Gooch Robert L Wong Hartmut Kupper Neesha Harnam Chris Thompson Joachim Sieper 《Arthritis research & therapy》2009,11(4):R124-12
Introduction
We evaluated the three-year impact of adalimumab on patient-reported physical function and health-related quality-of-life (HRQOL) outcomes in patients with active ankylosing spondylitis (AS). 相似文献8.
Stephan Wilmes Oliver Beutel Zhi Li Véronique Francois-Newton Christian P. Richter Dennis Janning Cindy Kroll Patrizia Hanhart Katharina H?tte Changjiang You Gilles Uzé Sandra Pellegrini Jacob Piehler 《The Journal of cell biology》2015,209(4):579-593
Type I interferons (IFNs) activate differential cellular responses through a shared cell surface receptor composed of the two subunits, IFNAR1 and IFNAR2. We propose here a mechanistic model for how IFN receptor plasticity is regulated on the level of receptor dimerization. Quantitative single-molecule imaging of receptor assembly in the plasma membrane of living cells clearly identified IFN-induced dimerization of IFNAR1 and IFNAR2. The negative feedback regulator ubiquitin-specific protease 18 (USP18) potently interferes with the recruitment of IFNAR1 into the ternary complex, probably by impeding complex stabilization related to the associated Janus kinases. Thus, the responsiveness to IFNα2 is potently down-regulated after the first wave of gene induction, while IFNβ, due to its ∼100-fold higher binding affinity, is still able to efficiently recruit IFNAR1. Consistent with functional data, this novel regulatory mechanism at the level of receptor assembly explains how signaling by IFNβ is maintained over longer times compared with IFNα2 as a temporally encoded cause of functional receptor plasticity. 相似文献
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