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21.
IMP1/imp1: A Gene Involved in the Nucleo-Mitochondrial Control of Galactose Fermentation in SACCHAROMYCES CEREVISIAE 总被引:8,自引:0,他引:8 下载免费PDF全文
In some strains of Saccharomyces cerevisiae, the induction of enzymes of the Leloir pathway, galactose fermentation and growth on galactose depend on mitochondrial function; mitochondrial dependence is elicited through the recessive allele imp1 of the nuclear gene IMP1. The genetic element IMP1 is not allelic to any of the known GAL genes; IMP1 strains can grow on and ferment galactose in respiratory-deficient (RD) condition or in the presence of the mitochondrial inhibitors ethidium bromide and erythromycin; whereas, imp1 strains can grow on and ferment galactose only in respiratory-sufficient (RS) condition. The imp1 elicited mitochondrial dependence apparently involves regulation of the synthesis of the galactose catabolizing enzymes and synthesis of the galactose specific permease. IMP1 is not the only genetic determinant that elicits an interaction of the mitochondrion and the expression of the Gal system; the GAL3 gene, whose role in galactose utilization is demonstrated by the long-term adaptation phenotype of gal3 RS mutants, gives rise to a noninducible phenotype in RD condition or in the presence of mitochondrial inhibitors. 相似文献
22.
Mark R. Condina Johan O. R. Gustafsson Manuela Klingler‐Hoffmann Christopher J. Bagley Shaun R. McColl Peter Hoffmann 《Proteomics》2010,10(13):2516-2530
The quality of MALDI‐TOF mass spectrometric analysis is highly dependent on the matrix and its deposition strategy. Although different matrix‐deposition methods have specific advantages, one major problem in the field of proteomics, particularly with respect to quantitation, is reproducibility between users or laboratories. Compounding this is the varying crystal homogeneity of matrices depending on the deposition strategy used. Here, we describe a novel optimised matrix‐deposition strategy for LC‐MALDI‐TOF/TOF MS using an automated instrument that produces a nebulised matrix “mist” under controlled atmospheric conditions. Comparisons of this with previously reported strategies showed the method to be advantageous for the atypical matrix, 2,5‐DHB, and improved phosphopeptide ionisation when compared with deposition strategies for CHCA. This optimised DHB matrix‐deposition strategy with LC‐MALDI‐TOF/TOF MS, termed EZYprep LC, was subsequently optimised for phosphoproteome analysis and compared to LC‐ESI‐IT‐MS and a previously reported approach for phosphotyrosine identification and characterisation. These methods were used to map phosphorylation on epidermal growth factor‐stimulated epidermal growth factor receptor to gauge the sensitivity of the proposed method. EZYprep DHB LC‐MALDI‐TOF/TOF MS was able to identify more phosphopeptides and characterise more phosphorylation sites than the other two proteomic strategies, thus proving to be a sensitive approach for phosphoproteome analysis. 相似文献
23.
Function of bovine CD46 as a cellular receptor for bovine viral diarrhea virus is determined by complement control protein 1 下载免费PDF全文
Krey T Himmelreich A Heimann M Menge C Thiel HJ Maurer K Rümenapf T 《Journal of virology》2006,80(8):3912-3922
The pestivirus bovine viral diarrhea virus (BVDV) was shown to bind to the bovine CD46 molecule, which subsequently promotes entry of the virus. To assess the receptor usage of BVDV type 1 (BVDV-1) and BVDV-2, 30 BVDV isolates including clinical samples were assayed for their sensitivity to anti-CD46 antibodies. With a single exception the infectivity of all tested strains of BVDV-1 and BVDV-2 was inhibited by anti-CD46 antibodies, which indicates the general usage of CD46 as a BVDV receptor. Molecular analysis of the interaction between CD46 and the BVD virion was performed by mapping the virus binding site on the CD46 molecule. Single complement control protein modules (CCPs) within the bovine CD46 were either deleted or replaced by analogous CCPs of porcine CD46, which does not bind BVDV. While the epitopes recognized by anti-CD46 monoclonal antibodies which block BVDV infection were attributed to CCP1 and CCP2, in functional assays only CCP1 turned out to be essential for BVDV binding and infection. Within CCP1 two short peptides on antiparallel beta strands were identified as crucial for the binding of BVDV. Exchanges of these two peptide sequences were sufficient for a loss of function in bovine CD46 as well as a gain of function in porcine CD46. Determination of the size constraints of CD46 revealed that a minimum length of four CCPs is essential for receptor function. An increase of the distance between the virus binding domain and the plasma membrane by insertion of one to six CCPs of bovine C4 binding protein exhibited only a minor influence on susceptibility to BVDV. 相似文献
24.
Structure of internalin,a major invasion protein of Listeria monocytogenes,in complex with its human receptor E-cadherin 总被引:13,自引:0,他引:13
Schubert WD Urbanke C Ziehm T Beier V Machner MP Domann E Wehland J Chakraborty T Heinz DW 《Cell》2002,111(6):825-836
Listeria monocytogenes, a food-borne bacterial pathogen, enters mammalian cells by inducing its own phagocytosis. The listerial protein internalin (InlA) mediates bacterial adhesion and invasion of epithelial cells in the human intestine through specific interaction with its host cell receptor E-cadherin. We present the crystal structures of the functional domain of InlA alone and in a complex with the extracellular, N-terminal domain of human E-cadherin (hEC1). The leucine rich repeat (LRR) domain of InlA surrounds and specifically recognizes hEC1. Individual interactions were probed by mutagenesis and analytical ultracentrifugation. These include Pro16 of hEC1, a major determinant for human susceptibility to L. monocytogenes infection that is essential for intermolecular recognition. Our studies reveal the structural basis for host tro-pism of this bacterium and the molecular deception L. monocytogenes employs to exploit the E-cadherin system. 相似文献
25.
Myotonia congenita (Thomsen's disease) excluded from the region of the myotonic dystrophy locus on chromosome 19 总被引:1,自引:0,他引:1
Manuela Koch Helen Harley M. Sarfarazi K. Bender T. Wienker Barbara Zoll P. S. Harper 《Human genetics》1989,82(2):163-166
Summary Linkage analysis has been carried out in six German families with autosomal dominantly inherited myotonia congenita (Thomsen's disease) using five chromosome 19 markers known to be linked to the gene for myotonic dystrophy (DM). Two of the markers, APOC1 and APOC2, are tightly linked to DM. Close linkage between these markers and myotonia congenita (MC) has been excluded to a distance of 9cM (z=-2.158). These data support the clinical suggestion that MC and DM are non-allelic disorders. 相似文献
26.
27.
Tonino G. Adessi Jos L. Borioni Natalia B. Pigni Jaume Bastida Valeria Cavallaro Ana P. Murray Marcelo Puiatti Juan C. Oberti Segundo Leiva Viviana E. Nicotra Manuela E. Garcia 《化学与生物多样性》2019,16(5)
Plants of the Amaryllidaceae family are well‐known (not only) for their ornamental value but also for the alkaloids that they produce. In this report, the first phytochemical study of Clinanthus genus was carried out. The chemical composition of alkaloid fractions from Clinanthus microstephium was analyzed by GC/MS and NMR. Seven known compounds belonging to three structural types of Amaryllidaceae alkaloids were identified. An epimeric mixture of a haemanthamine‐type compound (6‐hydroxymaritidine) was tested as an inhibitor against acetyl‐ and butyrylcholinesterase enzymes (AChE and BChE, respectively), two enzymes relevant in the treatment of Alzheimer's disease, with good results. Structure–activity relationships through molecular docking studies with this alkaloid and other structurally related compounds were discussed. 相似文献
28.
Flocculation is an eco-friendly process of cell separation, which has been traditionally exploited by the brewing industry.
Cell surface charge (CSC), cell surface hydrophobicity (CSH) and the presence of active flocculins, during the growth of two
(NCYC 1195 and NCYC 1214) ale brewing flocculent strains, belonging to the NewFlo phenotype, were examined. Ale strains, in
exponential phase of growth, were not flocculent and did not present active flocculent lectins on the cell surface; in contrast,
the same strains, in stationary phase of growth, were highly flocculent (>98%) and presented a hydrophobicity of approximately
three to seven times higher than in exponential phase. No relationship between growth phase, flocculation and CSC was observed.
For comparative purposes, a constitutively flocculent strain (S646-1B) and its isogenic non-flocculent strain (S646-8D) were
also used. The treatment of ale brewing and S646-1B strains with pronase E originated a loss of flocculation and a strong
reduction of CSH; S646-1B pronase E-treated cells displayed a similar CSH as the non-treated S646-8D cells. The treatment
of the S646-8D strain with protease did not reduce CSH. In conclusion, the increase of CSH observed at the onset of flocculation
of ale strains is a consequence of the presence of flocculins on the yeast cell surface and not the cause of yeast flocculation.
CSH and CSC play a minor role in the auto-aggregation of the ale strains since the degree of flocculation is defined, primarily,
by the presence of active flocculins on the yeast cell wall. 相似文献
29.
30.
María?F.?MonteroEmail author Manuela?Aristizábal Guillermo?García Reina 《Journal of applied phycology》2011,23(6):1053-1057
Biodiesel from algae is considered an alternative for a third generation of biofuels. However, most microalgae are not lipogenic
during fast growth periods, but high-lipid content occurs at resting stages. Microalgae biomass production for biodiesel needs
continuous high volumetric and aerial yields and large amount of neutral lipid in the biomass. These requirements are similar
to demanding a marathon runner to be obese. We show that by using cell sorting capabilities of flow cytometers, in combination
with the lipid-soluble fluorescent dye Nile Red, we can isolate and select cells with a high and stable lipid content. In
our study, we were able to select the equivalent of a stable “fat marathon runner” through three sorting events obtained from
wild populations of Tetraselmis suecica. 相似文献