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991.
Grant S Mastick W Todd Farmer Amy L Altick Hikmet Feyza Nural James P Dugan Thomas Kidd Frederic Charron 《Cell Adhesion & Migration》2010,4(3):337-341
Longitudinal axons grow long distances along precise pathways to connect major CNS regions. However, during embryonic development, it remains largely undefined how the first longitudinal axons choose specific positions and grow along them. Here, we review recent evidence identifying a critical role for Slit/Robo signals to guide pioneer longitudinal axons in the embryonic brain stem. These studies indicate that Slit/Robo signals from the floor plate have dual functions: to repel longitudinal axons away from the ventral midline, and also to maintain straight longitudinal growth. These dual functions likely cooperate with other guidance cues to establish the major longitudinal tracts in the brain.Key words: Slit, Robo, longitudinal axon, hindbrain, axon guidance 相似文献
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Grant MM 《BMB reports》2010,43(11):720-725
The small ubiquitin-like modifier (SUMO) proteins have been implicated in the pathology of a number of diseases, including neurodegenerative diseases. The conjugation machinery for SUMOylation consists of a number of proteins which are redox sensitive. Here, under oxidative stress (100 μM hydrogen peroxide), antioxidant (100 μM ascorbate) or control conditions 169 proteins were identified by electrospray ionisation fourier transform ion cyclotron resonance mass spectrometry. The majority of these proteins (70%) were found to contain SUMOylation consensus sequences. From the remaining proteins a small number (12%) were found to contain possible SUMO interacting motifs. The proteins identified included DNA and RNA binding proteins, structural proteins and proteasomal proteins. Several of the proteins identified under oxidative stress conditions had previously been identified as SUMOylated proteins, thus validating the method presented. 相似文献
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Microbial biofilms are composed of a hydrated matrix of biopolymers including polypeptides, polysaccharides and nucleic acids and act as a protective barrier and microenvironment for the inhabiting microbes. While studying marine biofilms, we observed that supernatant produced by a marine isolate of Bacillus licheniformis was capable of dispersing bacterial biofilms. We investigated the source of this activity and identified the active compound as an extracellular DNase (NucB). We have shown that this enzyme rapidly breaks up the biofilms of both Gram-positive and Gram-negative bacteria. We demonstrate that bacteria can use secreted nucleases as an elegant strategy to disperse established biofilms and to prevent de novo formation of biofilms of competitors. DNA therefore plays an important dynamic role as a reversible structural adhesin within the biofilm. 相似文献
996.
Tamara D. Clark Denise Njama-Meya Bridget Nzarubara Catherine Maiteki-Sebuguzi Bryan Greenhouse Sarah G. Staedke Moses R. Kamya Grant Dorsey Philip J. Rosenthal 《PloS one》2010,5(7)
Background
Combination therapies are now recommended to treat uncomplicated malaria. We used a longitudinal design to assess the incidence of malaria and compare the efficacies of 3 combination regimens in Kampala, Uganda.Methodology/Principal Findings
Children aged 1–10 years were enrolled from randomly selected households in 2004–05 and 2007, and were followed at least monthly through 2008. Insecticide-treated bednets (ITNs) were provided in 2006. Children were randomized upon their first episode, and then treated for all episodes of uncomplicated malaria with amodiaquine/sulfadoxine-pyrimethamine (AQ/SP), artesunate/amodiaquine (AS/AQ), or artemether/lumefantrine (AL). Risks of parasitological failure were determined for each episode of uncomplicated malaria and clinical parameters were followed. A total of 690 children experienced 1464 episodes of malaria. 96% of these episodes were uncomplicated malaria and treated with study drugs; 94% were due to Plasmodium falciparum. The rank order of treatment efficacy was AL > AS/AQ > AQ/SP. Failure rates increased over time for AQ/SP, but not the artemisinin-based regimens. Over the 4-year course of the study the prevalence of asymptomatic parasitemia decreased from 11.8% to 1.4%, the incidence of malaria decreased from 1.55 to 0.32 per person year, and the prevalence of anemia (hemoglobin <10 gm/dL) decreased from 5.9% to 1.0%. No episodes of severe malaria (based on WHO criteria) and no deaths were seen.Conclusions/Significance
With ready access to combination therapies and distribution of ITNs, responses were excellent for artemisinin-containing regimens, severe malaria was not seen, and the incidence of malaria and prevalence of parasitemia and anemia decreased steadily over time.Trial Registration
isrctn.org ISRCTN37517549 相似文献997.
Mai Xu Lindsey Mehl Tongwu Zhang Rohit Thakur Hayley Sowards Timothy Myers Lea Jessop Alessandra Chesi Matthew E. Johnson Andrew D. Wells Helen T. Michael Patricia Bunda Kristine Jones Herbert Higson Rebecca C. Hennessey Ashley Jermusyk Michael A. Kovacs Maria Teresa Landi Mark M. Iles Alisa M. Goldstein Melanoma Meta-Analysis Consortium Jiyeon Choi Stephen J. Chanock Struan F.A. Grant Raj Chari Glenn Merlino Matthew H. Law Kevin M. Brown 《American journal of human genetics》2021,108(9):1611-1630
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Morphology of the archaellar motor and associated cytoplasmic cone in Thermococcus kodakaraensis
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Ariane Briegel Catherine M Oikonomou Yi‐Wei Chang Andreas Kjær Audrey N Huang Ki Woo Kim Debnath Ghosal Hong H Nguyen Dorothy Kenny Rachel R Ogorzalek Loo Robert P Gunsalus Grant J Jensen 《EMBO reports》2017,18(9):1660-1670
Archaeal swimming motility is driven by archaella: rotary motors attached to long extracellular filaments. The structure of these motors, and particularly how they are anchored in the absence of a peptidoglycan cell wall, is unknown. Here, we use electron cryotomography to visualize the archaellar basal body in vivo in Thermococcus kodakaraensis KOD1. Compared to the homologous bacterial type IV pilus (T4P), we observe structural similarities as well as several unique features. While the position of the cytoplasmic ATPase appears conserved, it is not braced by linkages that extend upward through the cell envelope as in the T4P, but rather by cytoplasmic components that attach it to a large conical frustum up to 500 nm in diameter at its base. In addition to anchoring the lophotrichous bundle of archaella, the conical frustum associates with chemosensory arrays and ribosome‐excluding material and may function as a polar organizing center for the coccoid cells. 相似文献