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991.
Protoplasma - Spermatogenesis and spermatozoa ultrastructure of the amphibian leech Batracobdella algira Moquin-Tandon, 1846 (Hirudinida: Glossiphoniidae) have been investigated by means of... 相似文献
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Riveiro ME Moglioni A Vazquez R Gomez N Facorro G Piehl L de Celis ER Shayo C Davio C 《Bioorganic & medicinal chemistry》2008,16(5):2665-2675
In the present study, we sought to establish the effect of diverse structural-related hydroxycoumarins on the proliferation, cytotoxicity, and induction of apoptosis in promonocytic leukemic cells (U-937). The dihydroxylated coumarins, 7,8-dihydroxy-coumarin and esculetin, induced DNA fragmentation as well as characteristic morphological changes of programmed cell death in U-937 cells. With the aim to perform a structure-activity relationship study, the correlation between the physicochemical properties of the molecules and their pro-apoptotic activity was carried out. Results showed that the presence of two adjacent phenolic hydroxyl groups was the most important factor in terms of the SAR. The exposure of leukemic cells to 7,8-dihydroxy-coumarin evoked a phenoxyl radical generation that was detected by electron spin resonance spectroscopy. The present study suggests that reactive oxygen species generation plays a critical role in dihydroxycoumarin-induced apoptosis in U-937 cells. These findings further suggest that these compounds may have a potential therapeutic role in the treatment of hematological malignancies. 相似文献
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Protective immunity induced by an intranasal multivalent vaccine comprising 10 Lactococcus lactis strains expressing highly prevalent M‐protein antigens derived from Group A Streptococcus 下载免费PDF全文
Aniela Wozniak Natalia Scioscia Patricia C. García James B. Dale Braulio A. Paillavil Paulette Legarraga Francisco J. Salazar‐Echegarai Susan M. Bueno Alexis M. Kalergis 《Microbiology and immunology》2018,62(6):395-404
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Natalia V. Dolgova Susan Nehzati Sanjukta Choudhury Tracy C. MacDonald Nathan R. Regnier Andrew M. Crawford Olena Ponomarenko Graham N. George Ingrid J. Pickering 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(11):2383-2392
Background
Selenium is an essential element with a rich and varied chemistry in living organisms. It plays a variety of important roles ranging from being essential in enzymes that are critical for redox homeostasis to acting as a deterrent for herbivory in hyperaccumulating plants. Despite its importance there are many open questions, especially related to its chemistry in situ within living organisms.Scope of review
This review discusses X-ray spectroscopy and imaging of selenium in biological samples, with an emphasis on the methods, and in particular the techniques of X-ray absorption spectroscopy (XAS) and X-ray fluorescence imaging (XFI). We discuss the experimental methods and capabilities of XAS and XFI, and review their advantages and their limitations. A perspective on future possibilities and next-generation of experiments is also provided.Major conclusions
XAS and XFI provide powerful probes of selenium chemistry, together with unique in situ capabilities. The opportunities and capabilities of the next generation of advanced X-ray spectroscopy experiments are particularly exciting.General significance
XAS and XFI provide versatile tools that are generally applicable to any element with a convenient X-ray absorption edge, suitable for investigating complex systems essentially without pre-treatment. 相似文献998.
Kantor R Katzenstein DA Efron B Carvalho AP Wynhoven B Cane P Clarke J Sirivichayakul S Soares MA Snoeck J Pillay C Rudich H Rodrigues R Holguin A Ariyoshi K Bouzas MB Cahn P Sugiura W Soriano V Brigido LF Grossman Z Morris L Vandamme AM Tanuri A Phanuphak P Weber JN Pillay D Harrigan PR Camacho R Schapiro JM Shafer RW 《PLoS medicine》2005,2(4):e112
BackgroundThe genetic differences among HIV-1 subtypes may be critical to clinical management and drug resistance surveillance as antiretroviral treatment is expanded to regions of the world where diverse non-subtype-B viruses predominate.ConclusionGlobal surveillance and genotypic assessment of drug resistance should focus primarily on the known subtype B drug-resistance mutations. 相似文献
999.
Luca Goldoni Tiziana Beringhelli Walter Rocchia Natalia Realini Daniele Piomelli 《Analytical biochemistry》2016
Absolute analyte quantification by nuclear magnetic resonance (NMR) spectroscopy is rarely pursued in metabolomics, even though this would allow researchers to compare results obtained using different techniques. Here we report on a new protocol that permits, after pH-controlled serum protein removal, the sensitive quantification (limit of detection [LOD] = 5−25 μM) of hydrophilic nutrients and metabolites in the extracellular medium of cells in cultures. The method does not require the use of databases and uses PULCON (pulse length-based concentration determination) quantitative NMR to obtain results that are significantly more accurate and reproducible than those obtained by CPMG (Carr–Purcell–Meiboom–Gill) sequence or post-processing filtering approaches. Three practical applications of the method highlight its flexibility under different cell culture conditions. We identified and quantified (i) metabolic differences between genetically engineered human cell lines, (ii) alterations in cellular metabolism induced by differentiation of mouse myoblasts into myotubes, and (iii) metabolic changes caused by activation of neurotransmitter receptors in mouse myoblasts. Thus, the new protocol offers an easily implementable, efficient, and versatile tool for the investigation of cellular metabolism and signal transduction. 相似文献
1000.
Oxana V. Serova Alexander N. Orsa Natalia A. Chachina Alexander G. Petrenko 《Journal of receptor and signal transduction research》2019,39(1):67-72
Receptor tyrosine kinase (RTK) Met or c-Met is a target of hepatocyte growth factor (HGF) and it plays an important role under normal and pathological conditions. Activation of Met signaling pathway is associated with several cellular processes, such as proliferation, survival, motility, angiogenesis, invasion, and metastasis. In this article, we describe the ability of Met to activate upon a mild alkali treatment. To identify potential alkali-regulated proteins, CAKI-1 cells were treated with alkaline media and further tested for protein phosphorylation changes. By anti-phosphotyrosine antibody precipitation and lectin chromatography, we identified Met as a major cytoplasmic membrane protein that responded to pH changes by its phosphorylation. The activation of Met by alkali occurred at pH >8.0 and was dose-dependent. Specificity of the Met response to alkali was confirmed by the treatment with Met kinase inhibitor SU11274 and also by Met receptor knockout using CRISPR/CAS9 genome editing system. Both approaches completely blocked the Met phosphorylation response in CAKI-1 cells. Similar pH-dependent Met activation was observed in the HeLa cell line. Our data suggest existence of ligand-independent mechanism of Met receptor activation. 相似文献