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991.
Lykke K. B. Clausen Kasper N. Andersen Thomas L. Hygum Aslak Jørgensen Nadja Møbjerg 《Helgoland Marine Research》2014,68(4):531-537
Tardigrades are microscopic metazoans that withstand environmental extremes by entering dormant states, such as cryptobiosis (latent life). In addition, they may also form cysts. Here, we present the first report of cyst formation in a marine heterotardigrade, i.e., Echiniscoides sigismundi, which constitutes a cryptic species complex present worldwide in tidal zones. The cysts were initially discovered during experimental series constructed to investigate osmotic stress tolerance. The animals, which eventually formed cysts, showed signs of an imminent molt at the beginning of experimentation. We use the term “cyst” for stages, where a total of three or more cuticles have been synthesized. Our observations show that encystment in E. sigismundi involves synthesizing of at least two new cuticle layers. Legs with discharged claws are present in connection with the first outer cuticle, as well as the second cuticular layer. In the most developed cyst, a third cuticle lacking claws seems to surround the animal, which is delineated by a fourth cuticle. Many features are shared with the well-studied cysts of eutardigrades. The cysts of E. sigismundi, however, lack pigmentation and have an extra set of claws, and the animal inside retains buccopharyngeal sclerified parts, until discharging the third cuticle. The finding of cysts in a marine heterotardigrade is novel and confirms that encystment also occurs within this major evolutionary lineage. 相似文献
992.
Alan Andersen Jason Beringer C. Michael Bull Margaret Byrne Helen Cleugh Rebekah Christensen Kris French Bronwyn Harch Ary Hoffmann Andrew J. Lowe Tim Moltmann Adrienne Nicotra Andy Pitman Stuart Phinn Glenda Wardle Mark Westoby 《Austral ecology》2014,39(7):739-748
Australia's ecosystems are the basis of our current and future prosperity, and our national well‐being. A strong and sustainable Australian ecosystem science enterprise is vital for understanding and securing these ecosystems in the face of current and future challenges. This Plan defines the vision and key directions for a national ecosystem science capability that will enable Australia to understand and effectively manage its ecosystems for decades to come. The Plan's underlying theme is that excellent science supports a range of activities, including public engagement, that enable us to understand and maintain healthy ecosystems. Those healthy ecosystems are the cornerstone of our social and economic well‐being. The vision guiding the development of this Plan is that in 20 years' time the status of Australian ecosystems and how they change will be widely reported and understood, and the prosperity and well‐being they provide will be secure. To enable this, Australia's national ecosystem science capability will be coordinated, collaborative and connected. The Plan is based on an extensive set of collaboratively generated proposals from national town hall meetings that also form the basis for its implementation. Some directions within the Plan are for the Australian ecosystem science community itself to implement, others will involve the users of ecosystem science and the groups that fund ecosystem science. We identify six equal priority areas for action to achieve our vision: (i) delivering maximum impact for Australia: enhancing relationships between scientists and end‐users; (ii) supporting long‐term research; (iii) enabling ecosystem surveillance; (iv) making the most of data resources; (v) inspiring a generation: empowering the public with knowledge and opportunities; (vi) facilitating coordination, collaboration and leadership. This shared vision will enable us to consolidate our current successes, overcome remaining barriers and establish the foundations to ensure Australian ecosystem science delivers for the future needs of Australia. 相似文献
993.
Reza Karimi G?ran Tornling Helena Forsslund Mikael Mikko ?sa M Wheelock Sven Nyrén Carl Magnus Sk?ld 《Respiratory research》2014,15(1):23
Background
Smokers have increased cell concentration in the lower respiratory tract indicating a chronic inflammatory state, which in some individuals may lead to development of chronic obstructive pulmonary disease (COPD). Computer tomography (CT) imaging provides means of quantifying pulmonary structure and early signs of disease. We investigated whether lung density on high resolution CT differs between smokers and never-smokers and if this were associated to intensity of inflammation.Methods
Forty smoking volunteers with normal pulmonary function, 40 healthy never-smokers and 40 patients with COPD of GOLD stage I-II, were included. Mean lung attenuation and percentage of pixels in the lung with attenuation between −750 and −900 HU (percentage higher density spectrum (%HDS)) were calculated on inspiratory CT-scans. Markers of systemic inflammation in blood and cell counts in bronchoalveolar lavage (BAL) fluid were recorded.Results
Lung density expressed as %HDS was increased in smokers (44.0 ± 5.8%) compared to both never-smokers (38.3 ± 5.8%) and patients with COPD (39.1 ± 5.8%), (p < 0.001, for both). Females had denser lungs than males, which was dependent on body height. Cell concentration in BAL were correlated to lung density in smokers (r = 0.50, p < 0.001).Conclusions
Lung density on CT is associated with cell concentration in BAL in smokers and may mirror an inflammatory response in the lung. Gender difference in lung density is dependent on height. In COPD with emphysema, loss of lung tissue may counterbalance the expected increase in density due to inflammation. The findings may help to interpret high resolution CT in the context of smoking and gender and highlight the heterogeneity of structural changes in COPD. 相似文献994.
Christian B Matranga Kristian G Andersen Sarah Winnicki Michele Busby Adrianne D Gladden Ryan Tewhey Matthew Stremlau Aaron Berlin Stephen K Gire Eleina England Lina M Moses Tarjei S Mikkelsen Ikponmwonsa Odia Philomena E Ehiane Onikepe Folarin Augustine Goba S Humarr Kahn Donald S Grant Anna Honko Lisa Hensley Christian Happi Robert F Garry Christine M Malboeuf Bruce W Birren Andreas Gnirke Joshua Z Levin Pardis C Sabeti 《Genome biology》2014,15(11)
We have developed a robust RNA sequencing method for generating complete de novo assemblies with intra-host variant calls of Lassa and Ebola virus genomes in clinical and biological samples. Our method uses targeted RNase H-based digestion to remove contaminating poly(rA) carrier and ribosomal RNA. This depletion step improves both the quality of data and quantity of informative reads in unbiased total RNA sequencing libraries. We have also developed a hybrid-selection protocol to further enrich the viral content of sequencing libraries. These protocols have enabled rapid deep sequencing of both Lassa and Ebola virus and are broadly applicable to other viral genomics studies.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-014-0519-7) contains supplementary material, which is available to authorized users. 相似文献995.
Background
Illumina sequencing with its high number of reads and low per base pair cost is an attractive technology for development of molecular resources for non-model organisms. While many software packages have been developed to identify short tandem repeats (STRs) from next-generation sequencing data, these methods do not inform the investigator as to whether or not candidate loci are polymorphic in their target populations.Results
We provide a python program iMSAT that uses the polymorphism data obtained from mapping individual Illumina sequence reads onto a reference genome to identify polymorphic STRs. Using this approach, we identified 9,119 candidate polymorphic STRs for use with the parasitoid wasp Trioxys pallidus and 2,378 candidate polymorphic STRs for use with the aphid Chromaphis juglandicola. For both organisms we selected 20 candidate tri-nucleotide STRs for validation. Using fluorescent-labeled oligonucleotide primers, we genotyped 91 female T. pallidus collected in nine localities and 46 female C. juglandicola collected in 4 localities and found 15 of the examined markers to be polymorphic for T. pallidus and 12 of the examined markers to be polymorphic for C. juglandicola.Conclusions
We present a novel approach that uses standard Illumina barcoding primers and a single Illumina HiSeq run to target polymorphic STR fragments to develop and test STR markers. We validate this approach using the parasitoid wasp T. pallidus and its aphid host C. juglandicola. This approach, which would also be compatible with 454 Sequencing, allowed us to quickly identify markers with known variability. Accordingly, our method constitutes a significant improvement over existing STR identification software packages.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-858) contains supplementary material, which is available to authorized users. 相似文献996.
997.
Plant metabolites comprise a wide range of extremely important chemicals. In many cases, like savory spices, they combine distinctive functional properties—deterrence against herbivory—with an unmistakable flavor. Others have remarkable therapeutic qualities, for instance, the malaria drug artemisinin, or mechanical properties, for example natural rubber. We present a breakthrough in plant metabolite extraction technology. Using a neural network, we teach a computer how to recognize metabolite-rich cells of the herbal plant rosemary (Rosmarinus officinalis) and automatically extract the chemicals using a microrobot while leaving the rest of the plant undisturbed. Our approach obviates the need for chemical and mechanical separation and enables the extraction of plant metabolites that currently lack proper methods for efficient biomass use. Computer code required to train the neural network, identify regions of interest, and control the micromanipulator is available as part of the Supplementary Material.A method for autonomous extraction from individual cells using a micromanipulator is developed and applied to glandular trichomes. 相似文献
998.
999.
Nanna Hellum Nielsen Gunter Backes Jens Stougaard Stig Uggerh?j Andersen Ahmed Jahoor 《PloS one》2014,9(4)
Progress in plant breeding is facilitated by accurate information about genetic structure and diversity. Here, Diversity Array Technology (DArT) was used to characterize a population of 94 bread wheat (Triticum aestivum L.) varieties of mainly European origin. In total, 1,849 of 7,000 tested markers were polymorphic and could be used for population structure analysis. Two major subgroups of wheat varieties, GrI and GrII, were identified using the program STRUCTURE, and confirmed by principal component analysis (PCA). These subgroups were largely separated according to origin; GrI comprised varieties from Southern and Eastern Europe, whereas GrII contained mostly modern varieties from Western and Northern Europe. A large proportion of the markers contributing most to the genetic separation of the subgroups were located on chromosome 2D near the Reduced height 8 (Rht8) locus, and PCR-based genotyping suggested that breeding for the Rht8 allele had a major impact on subgroup separation. Consistently, analysis of linkage disequilibrium (LD) suggested that different selective pressures had acted on chromosome 2D in the two subgroups. Our data provides an overview of the allele composition of bread wheat varieties anchored to DArT markers, which will facilitate targeted combination of alleles following DArT-based QTL studies. In addition, the genetic diversity and distance data combined with specific Rht8 genotypes can now be used by breeders to guide selection of crossing parents. 相似文献
1000.
Fredrik Sj?vall Saori Morota Eleonor ?sander Frostner Magnus J. Hansson Eskil Elmér 《PloS one》2014,9(5)