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991.
992.
Cross talk between the KNOX and ethylene pathways is mediated by intron-binding transcription factors in barley 总被引:1,自引:0,他引:1
Osnato M Stile MR Wang Y Meynard D Curiale S Guiderdoni E Liu Y Horner DS Ouwerkerk PB Pozzi C Müller KJ Salamini F Rossini L 《Plant physiology》2010,154(4):1616-1632
In the barley (Hordeum vulgare) Hooded (Kap) mutant, the duplication of a 305-bp intron sequence leads to the overexpression of the Barley knox3 (Bkn3) gene, resulting in the development of an extra flower in the spikelet. We used a one-hybrid screen to identify four proteins that bind the intron-located regulatory element (Kap intron-binding proteins). Three of these, Barley Ethylene Response Factor1 (BERF1), Barley Ethylene Insensitive Like1 (BEIL1), and Barley Growth Regulating Factor1 (BGRF1), were characterized and their in vitro DNA-binding capacities verified. Given the homology of BERF1 and BEIL1 to ethylene signaling proteins, we investigated if these factors might play a dual role in intron-mediated regulation and ethylene response. In transgenic rice (Oryza sativa), constitutive expression of the corresponding genes produced phenotypic alterations consistent with perturbations in ethylene levels and variations in the expression of a key gene of ethylene biosynthesis. In barley, ethylene treatment results in partial suppression of the Kap phenotype, accompanied by up-regulation of BERF1 and BEIL1 expression, followed by down-regulation of Bkn3 mRNA levels. In rice protoplasts, BEIL1 activates the expression of a reporter gene driven by the 305-bp intron element, while BERF1 can counteract this activation. Thus, BEIL1 and BERF1, likely in association with other Kap intron-binding proteins, should mediate the fine-tuning of Bkn3 expression by ethylene. We propose a hypothesis for the cross talk between the KNOX and ethylene pathways. 相似文献
993.
Feinan Wu Nancy T. Eannetta Yimin Xu Jörg Plieske Martin Ganal Carlo Pozzi Nicolas Bakaher Steven D. Tanksley 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(4):809-827
Using single-copy conserved ortholog set (COSII) and simple sequence repeat (SSR) markers, we have constructed two genetic
maps for diploid Nicotiana species, N. tomentosiformis and N. acuminata, respectively. N. acuminata is phylogenetically closer to N. sylvestris than to N. tomentosiformis, the latter two of which are thought to contribute the S-genome and T-genome, respectively, to the allotetraploid tobacco
(N. tabacum L., 2n = 48). A comparison of the two maps revealed a minimum of seven inversions and one translocation subsequent to the divergence
of these two diploid species. Further, comparing the diploid maps with a dense tobacco map revealed that the tobacco genome
experienced chromosomal rearrangements more frequently than its diploid relatives, supporting the notion of accelerated genome
evolution in allotetraploids. Mapped COSII markers permitted the investigation of Nicotiana–tomato syntenic relationships. A minimum of 3 (and up to 10) inversions and 11 reciprocal translocations differentiate the
tomato genome from that of the last common ancestor of N. tomentosiformis and N. acuminata. Nevertheless, the marker/gene order is well preserved in 25 conserved syntenic segments. Molecular dating based on COSII
sequences suggested that tobacco was formed 1.0MYA or later. In conclusion, these COSII and SSR markers link the cultivated
tobacco map to those of wild diploid Nicotiana species and tomato, thus providing a platform for cross-reference of genetic and genomic information among them as well as
other solanaceous species including potato, eggplant, pepper and the closely allied coffee (Rubiaceae). Therefore they will
facilitate genetic research in the genus Nicotiana. 相似文献
994.
Strategies adopted by parasitoids and kleptoparasites co-evolve with the defensive adaptations of their hosts, and vice-versa.
Hedychrum rutilans and Hedychrum nobile are brood parasites of, respectively, Philanthus triangulum and Cerceris arenaria, two digger wasps that share most aspects of their nesting biology (solitary females dig aggregated nests in the ground and
mass-provision the brood with paralyzed insects). We tested the hypothesis that similarity in the hosts’ nesting habits corresponds
to similar defensive strategies against these cuckoo wasps. Peak provisioning activity by P. triangulum occurred in late afternoon (and early morning in 1 year) while peak H. rutilans activity was in early afternoon. In contrast, peak provisioning by C. arenaria and peak H. nobile activity occurred in early afternoon. Thus, P. triangulum (as previously found in other populations) appears to have timed its provisioning to avoid its brood parasite whereas C. arenaria did not, rejecting our hypothesis. The daily activity of both chrysidid wasps was positively correlated to air temperature.
Host nest density positively affected only H. rutilans activity, in agreement with previous reports for other populations of this species, whereas the daily pattern of activity
of the host was the key correlate with the activity of H. nobile. Mortality due to cuckoo wasps was low for both digger wasps, although it was somewhat higher at sites with many nests of
P. triangulum. We suggest that perhaps the degree to which digger wasps time their activity to avoid cuckoo wasps is related to the degree
of specialization in host choice by their brood parasite. H. rutilans is more highly dependent on P. triangulum, which may have had a greater effect on the timing of provision by its host. 相似文献
995.
Ralf Frederik Claas Michael ter Braak Bianca Hegen Verena Hardel Carlo Angioni Helmut Schmidt Karl H. Jakobs Paul P. Van Veldhoven Dagmar Meyer zu Heringdorf 《Cellular signalling》2010,22(3):476-483
Sphingosine-1-phosphate (S1P) regulates cell growth and survival, migration and adhesion in many cell types. S1P is generated by sphingosine kinases (SphKs), and dephosphorylated by phosphatases or cleaved by S1P lyase. Extracellular S1P activates specific G protein-coupled receptors while intracellular S1P can mobilize Ca2+ from thapsigargin-sensitive stores. Here, we have studied Ca2+ signalling in mouse embryonic fibroblasts (MEFs) deficient in S1P lyase. In these cells, S1P and sphingosine concentrations were elevated about 6-fold and 2-fold, respectively, as measured by liquid chromatography/tandem mass spectrometry. Measurements with fura-2-loaded cells in suspension revealed that resting [Ca2+]i was elevated and agonist-induced [Ca2+]i increases were augmented in S1P lyase-deficient MEFs both in the presence and absence of extracellular Ca2+. Importantly, [Ca2+]i increases and Ca2+ mobilization induced by the SERCA inhibitor, thapsigargin, were augmented, indicating enhanced Ca2+ storage in S1P lyase-deficient MEFs. Measurements with single cells expressing the calmodulin-based Ca2+ sensor, cameleon, revealed that at least two cell types could be distinguished in both MEF cell populations, one with a rapid and transient [Ca2+]i increase and the other with a slower and prolonged [Ca2+]i elevation upon stimulation with thapsigargin. The area under the time course of thapsigargin-induced [Ca2+]i increases, reflecting overall Ca2+ release, was significantly increased by more than 50% in both rapidly and slowly responding S1P lyase-deficient cells. It is concluded that elevated concentrations of S1P and/or sphingosine lead to enhanced Ca2+ storage and elevated basal [Ca2+]i. S1P metabolism thus plays a role not only in acute Ca2+ mobilization but also in long-term regulation of Ca2+ homeostasis. 相似文献
996.
Bergamini Carlo M. Dondi Alessia Lanzara Vincenzo Squerzanti Monica Cervellati Carlo Montin Katy Mischiati Carlo Tasco Gianluca Collighan Russel Griffin Martin Casadio Rita 《Amino acids》2010,39(1):297-304
Amino Acids - The transamidating activity of tissue transglutaminase is regulated by the ligands calcium and GTP, via conformational changes which facilitate or interfere with interaction with the... 相似文献
997.
Bruna I. Menozzi Mirca Zotti Carlo Montanari 《Vegetation History and Archaeobotany》2010,19(5-6):503-512
As part of a regional research project on wetlands, a analysis was carried out on non pollen palynomorphs (NPP) from the upper sediments of a mountain peat bog in the Ligurian Apennines, northwest Italy. The aim of this project was to see if NPPs could yield useful results on local ecology and human activity in connection with the use of resources. More than 60 NPP types were found, among which a new type is described. A good agreement was observed between pollen assemblages and different NPP types, which are still an under-exploited source of information. Coprophilous fungi suggest the presence of livestock at the site after cal. a.d. 770–1160, while various algae and other water-demanding organisms show an increasing eutrophication of the environment in the most recent phase after cal. a.d. 1500. This approach, which is new for this region, confirms the hypothesis that local farming practices, such as management of pasture and woodland, were not recently established here. The site features and both NPP variety and significance show that further improvement of this additional tool could contribute to answering some questions about past cultural landscapes. 相似文献
998.
Oscar F. D’Urso Pietro I. D’Urso Carlo Storelli Santo Marsigliante 《Molecular biology reports》2010,37(3):1435-1438
We developed an array-based subtractive hybridization system for one-step high-throughput subtraction. We printed subtractor
RNA up to 10.000 times obtaining an excellent contact surface using a little amount of RNA. During hybridization cDNA, common
to subtractor and target samples, remains attached to slide immobilized RNA, leaving free in solution target specific cDNA
which after retrieval is cloned. 相似文献
999.
外来入侵害虫刺槐叶瘿蚊的重要天敌——刺槐叶瘿蚊广腹细蜂 总被引:1,自引:0,他引:1
外来入侵害虫刺槐叶瘿蚊Obolodiplosis robiniae (Haldemann) 原产北美洲东部, 2006 年在中国发现, 危害刺槐叶片, 严重影响刺槐的健康生长, 已经列入我国检疫性害虫名单。在河北省秦皇岛市野外调查, 发现了一种广腹细蜂科天敌--叶瘿蚊广腹细蜂Platygaster robiniae Buhl and Duso, 该寄生蜂属中国新记录种。野外观察表明其对刺槐叶瘿蚊最高寄生率达84.8%, 具有良好的生物防治应用前景。本文对该广腹细蜂的外部形态和初步观察的生物学特性进行了描述。 相似文献
1000.
Soccorsa Pensato Mario Renda Felicia Leccia Michele Saviano Luca D. D'Andrea Carlo Pedone Paolo V. Pedone Alessandra Romanelli 《Biopolymers》2010,93(5):434-441
The article describes the use of a PNA duplex (PNA zipper) as a tool to dimerize or bring in close proximity two polypeptides or protein domains. The amino acid sequence to be dimerized is covalently bound to complementary PNA sequences. Annealing of the PNA strands results in dimer formation. To test the ability of the “PNA‐zipper” as a dimerization tool, we designed a GCN4 mimetic, where the leucine‐zipper dimerization domain was replaced by the PNA zipper, whereas the basic DNA‐binding domain was covalently attached to the PNA. The molecule was assembled by chemical ligation of the peptide corresponding to the DNA‐binding domain of GCN4 modified with a succinyl thioester with two complementary PNAs harboring a cysteine residue. Electromobility‐shift experiments show the ability of the PNA zipper‐GCN4 to bind selected DNA duplexes. The PNA zipper‐GCN4 binds both the TRE and CRE DNA sites, but it does not bind TRE and CRE mutants containing even a single base mutation, as the native GCN4. The ability to fold upon complexation with DNA was investigated by CD. A good correlation between the ability of the PNA zipper‐GCN4 to fold into α helices and the ability to bind DNA was found. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 434–441, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com 相似文献