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991.
Sergio Mauro Françoise Van Eycken Najib Challou Patrick Lucas Michèle L'Oiseau 《Physiologia plantarum》2005,124(3):323-335
The response of superoxide dismutases (SOD, EC1.15.1.1) to chilling-induced oxidative stress in differentially sensitive maize genotypes ( Zea mays L) was examined. A native 2D-PAGE system that resolves the maize leaf SOD isoforms has been developed. The chloroplastic SOD activity was resolved into four Cu/Zn SOD isoforms designated SOD1a→d with pI values of 3.9, 4.0, 4.5 and 5.6, respectively. These SODs are located in the stroma and display a higher resistance to hydrogen peroxide inactivation than the cytosol Cu/ZnSODs. They operate as 32 kDa homodimers and have an AT motif at the NH2 -terminal, which characterizes the chloroplastic SODs of most species. A light chilling treatment resulted in a rapid increase in the activity of SOD1a and SOD1b . Because this increase was observed in the presence of the protein synthesis inhibitor cycloheximide, it is suggested that short-term regulation of chloroplastic SODs occurs at a post-translational level. 相似文献
992.
Endocytosis via caveolae 总被引:7,自引:0,他引:7
Caveolae are flask-shaped invaginations present in the plasma membrane of many cell types. They have long been implicated in endocytosis, transcytosis, and cell signaling. Recent work has confirmed that caveolae are directly involved in the internalization of membrane components (glycosphingolipids and glycosylphosphatidylinositol-anchored proteins), extracellular ligands (folic acid, albumin, autocrine motility factor), bacterial toxins (cholera toxin, tetanus toxin), and several nonenveloped viruses (Simian virus 40, Polyoma virus). Unlike clathrin-mediated endocytosis, internalization through caveolae is a triggered event that involves complex signaling. The mechanism of internalization and the subsequent intracellular pathways that the internalized substances take are starting to emerge. 相似文献
993.
994.
995.
Ernest R. Chan Lucas D. Jones Marlin Linger Jeffrey D. Kovach Maria M. Torres-Teran Audric Wertz Curtis J. Donskey Peter A. Zimmerman 《PLoS genetics》2022,18(9)
SARS-CoV-2 whole genome sequencing has played an important role in documenting the emergence of polymorphisms in the viral genome and its continuing evolution during the COVID-19 pandemic. Here we present data from over 360 patients to characterize the complex sequence diversity of individual infections identified during multiple variant surges (e.g., Alpha and Delta). Across our survey, we observed significantly increasing SARS-CoV-2 sequence diversity during the pandemic and frequent occurrence of multiple biallelic sequence polymorphisms in all infections. This sequence polymorphism shows that SARS-CoV-2 infections are heterogeneous mixtures. Convention for reporting microbial pathogens guides investigators to report a majority consensus sequence. In our study, we found that this approach would under-report sequence variation in all samples tested. As we find that this sequence heterogeneity is efficiently transmitted from donors to recipients, our findings illustrate that infection complexity must be monitored and reported more completely to understand SARS-CoV-2 infection and transmission dynamics. Many of the nucleotide changes that would not be reported in a majority consensus sequence have now been observed as lineage defining SNPs in Omicron BA.1 and/or BA.2 variants. This suggests that minority alleles in earlier SARS-CoV-2 infections may play an important role in the continuing evolution of new variants of concern. 相似文献
996.
997.
Bleicher L de Moura PR Watanabe L Colau D Dumoutier L Renauld JC Polikarpov I 《FEBS letters》2008,582(20):2985-2992
Interleukin-22 (IL-22) is a member of the interleukin-10 cytokine family, which is involved in anti-microbial defenses, tissue damage protection and repair, and acute phase responses. Its signaling mechanism involves the sequential binding of IL-22 to interleukin-22 receptor 1 (IL-22R1), and of this dimer to interleukin-10 receptor 2 (IL-10R2) extracellular domain. We report a 1.9A crystal structure of the IL-22/IL-22R1 complex, revealing crucial interacting residues at the IL-22/IL-22R1 interface. Functional importance of key residues was confirmed by site-directed mutagenesis and functional studies. Based on the X-ray structure of the binary complex, we discuss a molecular basis of the IL-22/IL-22R1 recognition by IL-10R2. STRUCTURED SUMMARY: 相似文献
998.
DNA degradation in avian faecal samples and feasibility of non-invasive
genetic studies of threatened capercaillie populations 总被引:1,自引:0,他引:1
We evaluated the feasibility of using faeces as a non-invasively collected DNA source for the genetic study of an endangered bird population (capercaillie; Tetrao urogallus). We used a multitube approach, and for our panel of 11 microsatellites genotyping reliability was estimated at 98% with five repetitions. Experiments showed that free DNases in faecal material were the major cause of DNA degradation. Our results demonstrate that using avian faeces as a source of DNA, reliable microsatellite genotyping can be obtained with a reasonable number of PCR replicates. 相似文献
999.
Sandro Bertolino Nicola Cordero di Montezemolo Damiano G. Preatoni Lucas A. Wauters Adriano Martinoli 《Biological invasions》2014,16(1):53-62
Introduced mammals can cause extinction of native species due to replacement competition, disease, predation or hybridization. We studied the colonization of Piedmont (NW-Italy) by American grey squirrel (Sciurus carolinensis) and its effect on the native red squirrel (Sciurus vulgaris). Presence/absence data (2 × 2 km2), of both species were (re)constructed using questionnaires, literature, existing databases, unpublished information, and direct monitoring with hair-tubes. In 1970 red squirrels were still widespread and greys were restricted to forests near the introduction site. By 1990, grey squirrels had increased their range to 220 km2, which coincided with the disappearance of native squirrels from 33 squares inside this range. The invasive species continued its spread occupying an area of 2,016 km2 in 2010; within this area red squirrels went extinct in 88 squares. Overall, from 1970 to 2010 red squirrel went extinct in 62 % of 2 × 2 km2 (ca. 1,689 km2), and were replaced by grey squirrels. The spread of the alien species was slow in the first 20 years, but doubled in the successive two decades. Nevertheless spread was slower than in Ireland and England. Grey squirrel adapt to climate and habitats in both North and South Europe, causing extinction of the native red squirrel. A EU LIFE co-funded project with the aim to control the grey squirrel in North Italy and recent trade-restrictions and trade-ban are a first step in reducing the risk of grey squirrels invading other countries, but their effectiveness will have to be evaluated. 相似文献
1000.
Edgar C. Turner Hanna M. V. Granroth Henry R. Johnson Colin B. H. Lucas Alex M. Thompson Hannah Froy Richard N. German Ross Holdgate 《Journal of Insect Conservation》2009,13(5):475-486
The Duke of Burgundy butterfly (Hamearis lucina) has declined severely since the 1970s and is a UK Biodiversity Action Plan Priority species. Its populations are mostly
confined to scrubby calcareous grassland, where management for short-turf species can be detrimental to the butterfly. We
briefly review the literature on the Duke of Burgundy and investigate their habitat preferences, survival and dispersal at
a chalk grassland reserve in Bedfordshire, UK. We found that adults generally preferred more sheltered locations but that
their habitat preferences were less restrictive than choice of food-plants. Females chose larger plants with longer leaves
in denser patches on which to lay eggs. Adults showed reasonable dispersal ability with turnover recorded between areas isolated
by scrub. Our results indicate that the species is able to use isolated areas of favourable habitat at a reserve scale and
that conservation could therefore involve cyclic management to provide suitable habitat year-to-year. 相似文献