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941.
Vujanovic Vladimir; St-Arnaud Marc; Barabe Denis; Thibeault Genevieve 《Annals of botany》2000,86(1):79-86
This study reports the ability of Fusarium to induce orchidseed colouration and germination. The in vitro bioassay germinationtest, using a Fusarium isolate from the protocorm of Cypripediumreginae, was compared with standard chemical procedures of triphenyltetrazolium chloride (TTC) and acid fuchsin (AC) for testingseed viability. With Cypripedium reginae, Cypripedium parviflorumand Platanthera grandiflora, the efficiency of the bioassaywas similar to that of the TTC and AC procedures. However, thebioassay was more appropriate for estimating embryo viabilityafter a prolonged seed pretreatment (more than 2 h) in 10% sodiumhypochlorite, a surface sterilant often used to enhance germinationof terrestrial species. We also obtained in vitro Cypripediumreginae seed germination induction and protocorm formation bythe same Fusarium isolate. This is the first confirmation ofBernard's early reports that orchid fusaria could stimulateseed germination (Bernard N. 1990.Révue Généralede Botanique12 : 108120). However, the importance ofthe non-mycorrhizal Fusarium fungus in promoting germinationseems to be relatively minor compared to that of specificRhizoctoniaorchid mycorrhizas. Our results are discussed in light of thecurrent North American strategy on orchid conservation methodswhich proposes the use of symbiotic germination.Copyright 2000Annals of Botany Company Orchid, Cypripedium, Platanthera, seed, Fusarium, bioassay, staining, viability, germination, protocorm, mycorrhiza 相似文献
942.
Bienvenut WV Déon C Pasquarello C Campbell JM Sanchez JC Vestal ML Hochstrasser DF 《Proteomics》2002,2(7):868-876
Although peptide mass fingerprinting is currently the method of choice to identify proteins, the number of proteins available in databases is increasing constantly, and hence, the advantage of having sequence data on a selected peptide, in order to increase the effectiveness of database searching, is more crucial. Until recently, the ability to identify proteins based on the peptide sequence was essentially limited to the use of electrospray ionization tandem mass spectrometry (MS) methods. The recent development of new instruments with matrix-assisted laser desorption/ionization (MALDI) sources and true tandem mass spectrometry (MS/MS) capabilities creates the capacity to obtain high quality tandem mass spectra of peptides. In this work, using the new high resolution tandem time of flight MALDI-(TOF/TOF) mass spectrometer from Applied Biosystems, examples of successful identification and characterization of bovine heart proteins (SWISS-PROT entries: P02192, Q9XSC6, P13620) separated by two-dimensional electrophoresis and blotted onto polyvinylidene difluoride membrane are described. Tryptic protein digests were analyzed by MALDI-TOF to identify peptide masses afterward used for MS/MS. Subsequent high energy MALDI-TOF/TOF collision-induced dissociation spectra were recorded on selected ions. All data, both MS and MS/MS, were recorded on the same instrument. Tandem mass spectra were submitted to database searching using MS-Tag or were manually de novo sequenced. An interesting modification of a tryptophan residue, a "double oxidation", came to light during these analyses. 相似文献
943.
Zhu Y Carragher B Glaeser RM Fellmann D Bajaj C Bern M Mouche F de Haas F Hall RJ Kriegman DJ Ludtke SJ Mallick SP Penczek PA Roseman AM Sigworth FJ Volkmann N Potter CS 《Journal of structural biology》2004,145(1-2):3-14
Manual selection of single particles in images acquired using cryo-electron microscopy (cryoEM) will become a significant bottleneck when datasets of a hundred thousand or even a million particles are required for structure determination at near atomic resolution. Algorithm development of fully automated particle selection is thus an important research objective in the cryoEM field. A number of research groups are making promising new advances in this area. Evaluation of algorithms using a standard set of cryoEM images is an essential aspect of this algorithm development. With this goal in mind, a particle selection "bakeoff" was included in the program of the Multidisciplinary Workshop on Automatic Particle Selection for cryoEM. Twelve groups participated by submitting the results of testing their own algorithms on a common dataset. The dataset consisted of 82 defocus pairs of high-magnification micrographs, containing keyhole limpet hemocyanin particles, acquired using cryoEM. The results of the bakeoff are presented in this paper along with a summary of the discussion from the workshop. It was agreed that establishing benchmark particles and using bakeoffs to evaluate algorithms are useful in promoting algorithm development for fully automated particle selection, and that the infrastructure set up to support the bakeoff should be maintained and extended to include larger and more varied datasets, and more criteria for future evaluations. 相似文献
944.
945.
N Denis S Blanc M P Leibovitch N Nicolaiew F Dautry M Raymondjean J Kruh A Kitzis 《Experimental cell research》1987,172(1):212-217
The role of c-myc oncogene expression in myogenic differentiation has been established by transfecting rat myoblasts of the L6 cell line with plasmid pMT-myc, in which the c-myc coding sequences were under the control of the metallothionein I promoter. We observed that the constitutive expression of the exogenous c-myc gene inhibits muscular differentiation. A diminution of the endogenous c-myc gene expression occurs within the first 24 h after the transfer of the cells to a differentiating medium. This early decrease of c-myc expression is required for cell differentiation to occur. We have also observed that exogenous myc gene expression has no effect on endogenous myc expression. 相似文献
946.
Scientists studying diseases of invertebrates in the USA, Europe, and Asia began to meet at international congresses in the 1950s and early 1960s, and soon recognized that they needed both a society and a journal where their common interests could be discussed and their findings presented. Edward A. Steinhaus played a major role in bringing together scientists from across the globe with common interests in these diseases. As a consequence, the Journal of Invertebrate Pathology (then Journal of Insect Pathology) was initiated in 1959 and Steinhaus became its first editor. Along with Albert Sparks he organized a meeting at Seattle, Washington in 1967 that led to the founding of the Society for Invertebrate Pathology with Steinhaus as its first President. The Society held its first meeting at Ohio State University in 1968, and has continued to meet annually. The Society has instituted a Founder's Lecture series, graduate student awards, and Divisions of Microbial Control, Microsporidia, Bacteriology, Fungi, Viruses, and Nematodes. Members enjoy several social functions at meetings as well as symposia, submitted papers, and poster sessions. The Society for Invertebrate Pathology is a truly international organization which to date has held meetings in 13 countries and 14 US states, usually attended by members from at least 20 countries. 相似文献
947.
Galland Stéphane Le Borgne Françoise Guyonnet Denis Clouet Pierre Demarquoy Jean 《Molecular and cellular biochemistry》1998,178(1-2):163-168
The biosynthesis of carnitine from lysine and methionine involves five enzymatic reactions. -butyrobetaine hydroxylase (BBH; EC 1.14.11.1) is the last enzyme of this pathway. It catalyzes the reaction of hydroxylation of -butyrobetaine to carnitine. This enzyme had never been purified to homogeneity from rat tissue. This paper describes the purification and characterization of the rat liver BBH. This protein has been purified some 413 fold by ion exchange, affinity and gel-filtration chromatographies and appears as a dimere of 43,000 Daltons subunits by PAGE. The affinity chromatography column used in the purification process utilizes 3-(2,2,2-trimethylhydrazinium)propionate (THP), a BBH inhibitor, as the ligand. Polyclonal antibodies were raised against the liver enzyme. They were able to precipitate BBH activity in either a crude liver extract or a purified fraction of the enzyme. Furthermore, it crossreacts with a 43 kDa protein in the liver. No evidence for extra hepatic enzyme was found. 相似文献
948.
McDonald IR Miguez CB Rogge G Bourque D Wendlandt KD Groleau D Murrell JC 《FEMS microbiology letters》2006,255(2):225-232
Methanotrophs were enriched and isolated from polluted environments in Canada and Germany. Enrichments in low copper media were designed to specifically encourage growth of soluble methane monooxygenase (sMMO) containing organisms. The 10 isolates were characterized physiologically and genetically with one type I and nine type II methanotrophs being identified. Three key genes: 16S rRNA; pmoA and mmoX, encoding for the particulate and soluble methane monooxygenases respectively, were cloned from the isolates and sequenced. Phylogenetic analysis of these sequences identified strains, which were closely related to Methylococcus capsulatus, Methylocystis sp., Methylosinus sporium and Methylosinus trichosporium. Diversity of sMMO-containing methanotrophs detected in this and previous studies was rather narrow, both genetically and physiologically, suggesting possible constraints on genetic diversity of sMMO due to essential conservation of enzyme function. 相似文献
949.
Gavathiotis E Reyna DE Bellairs JA Leshchiner ES Walensky LD 《Nature chemical biology》2012,8(7):639-645
BCL-2 family proteins are key regulators of the apoptotic pathway. Antiapoptotic members sequester the BCL-2 homology 3 (BH3) death domains of proapoptotic members such as BAX to maintain cell survival. The antiapoptotic BH3-binding groove has been successfully targeted to reactivate apoptosis in cancer. We recently identified a geographically distinct BH3-binding groove that mediates direct BAX activation, suggesting a new strategy for inducing apoptosis by flipping BAX's 'on switch'. Here we applied computational screening to identify a BAX activator molecule that directly and selectively activates BAX. We demonstrate by NMR and biochemical analyses that the molecule engages the BAX trigger site and promotes the functional oligomerization of BAX. The molecule does not interact with the BH3-binding pocket of antiapoptotic proteins or proapoptotic BAK and induces cell death in a BAX-dependent fashion. To our knowledge, we report the first gain-of-function molecular modulator of a BCL-2 family protein and demonstrate a new paradigm for pharmacologic induction of apoptosis. 相似文献
950.
Zaruhi P Poghosyan Katerina Giannoulia Panagiotis Katinakis Denis J Murphy Polydefkis Hatzopoulos 《Plant Physiology and Biochemistry》2005,43(1):37-44
Enoyl-ACP reductase is a catalytic component of the fatty acid synthetase (FAS) type II system in plants that is involved in the de novo fatty acid biosynthesis in plastids. A cDNA encoding an enoyl-ACP reductase responsible for the removal of the trans-unsaturated double bonds to form saturated acyl-ACP has been isolated from a library made from ripening fruits of Olea europaea L. The predicted protein contains 393 amino acid residues including a consensus chloroplast specific transit peptide. A strong homology was observed when olive enoyl-ACP reductase aligned with other plant sequences. Southern hybridization analysis revealed that enoyl-ACP reductase is encoded by a single gene in olives. Northern hybridization showed a transient expression of the enoyl-ACP reductase (ENR) gene at early stages of drupe (5-7 weeks after flowering, WAF), embryo and endosperm (13-16 WAF) while in mesocarp (13-19 WAF) the expression remained at high levels. In situ hybridization showed particularly prominent expression in the palisade and vascular tissue of young leaves, the tapetum, developing pollen grains and vascular tissue of anthers and to less extent in the embryo sac and transmitting tissue of the carpel. The distinctive spatial and temporal regulation of the ENR gene is consistent with major roles, not only in thylakoid membrane formation and fatty acid deposition, but also in the provision of precursor molecules for the biosynthesis of oxilipins that are important in plant tissues involved in transportation and reproduction. 相似文献