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Relative Ability of Orally Administered Lactobacillus murinus To Predominate and Persist in the Porcine Gastrointestinal Tract 总被引:1,自引:0,他引:1 下载免费PDF全文
Gillian E. Gardiner Pat G. Casey Garrett Casey P. Brendan Lynch Peadar G. Lawlor Colin Hill Gerald F. Fitzgerald Catherine Stanton R. Paul Ross 《Applied microbiology》2004,70(4):1895-1906
Five porcine-derived Lactobacillus or Pediococcus isolates administered to pigs (n = 4), either singly or as a combination at ~1010 CFU per day varied with respect to intestinal survival and persistence. Two Lactobacillus murinus strains survived best and were excreted at ~107 to 108 CFU/g of feces. In contrast, Pediococcus pentosaceus DPC6006 had the lowest fecal count at ~105 CFU/g and was excreted at a significantly lower level than both L. murinus strains. Fecal L. murinus DPC6003 counts were also significantly higher than both Lactobacillus salivarius DPC6005 and Lactobacillus pentosus DPC6004 (~106 CFU/g). The L. murinus strains persisted for at least 9 days postadministration in both the feces and the cecum. Animals fed a combination of all five strains excreted ~107 CFU of the administered strains/g, with L. murinus predominating, as determined by randomly amplified polymorphic DNA PCR. Postadministration, variation was observed between animals fed the strain combination, but in general, L. murinus DPC6002 and DPC6003 and L. pentosus DPC6004 predominated in the feces and the cecum while P. pentosaceus DPC6006 was detected only in the cecum. Fifteen days after the start of culture administration, mean fecal Enterobacteriaceae counts were significantly lower in some of the treatment groups. In addition, when mean preadministration counts were compared with those obtained after 21 days of culture administration, Enterobacteriaceae counts were reduced by ~87 to 98% in pigs fed L. salivarius DPC6005, P. pentosaceus DPC6006, L. pentosus DPC6004, and the culture mix. In conclusion, the porcine intestinal isolates have potential as probiotic feed additives for pigs, with differences in strain performance highlighting the advantages of using culture combinations. 相似文献
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The interaction of alpha- and beta-oligoarginine amides and acids and of alpha-polyarginine with anionic lipid vesicles was studied. The beta-oligoarginines used were beta3-homologues of the alpha-oligoarginines. Lipid bilayers were composed of POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and POPG (1-palmitoyl-2-oleoyl-sn-glycero-3-[phospho-rac-(1-glycerol)]) containing 5 mol % pyrene-PG (1-hexadecanoyl-2-(1-pyrenedecanoyl)-sn-glycero-3-[phospho-rac-1-glycerol]). Kinetic analysis of the binding process onto large unilamellar POPC/POPG (3:7, molar ratio) vesicles (100 nm diameter) shows biphasic time courses for all tested peptides. The first binding step is fast and takes place within approximately 10 s with no disruption of the membrane as indicated by corresponding calcein release measurements. The second binding phase is slow and occurs within the next 30-300 s with substantial membrane disruption. In this context, beta-hexa- and octaarginine amides possess higher second half-times than the beta-hexa- and octaarginine acids of the same chain length. Furthermore beta-octaarginine amide induces a calcein release approximately twice as large as that of the beta-octaarginine acid. Thermodynamic analysis of the binding process, using the complex formation model that assumes that each peptide binds independently to n POPG lipids, reveals apparent binding constants (K(app1)) of approximately 5 x 10(6)-10(8) M(-1) and n-values from 3.7 for beta-hexaarginine acid up to 24.8 for alpha-polyarginine. Although the K(app1)-values are similar, the number of binding sites clearly depends on the chemical nature of the oligoarginine: beta-oligoarginine amides and alpha-oligoarginine acids interact with more lipids than beta-oligoarginine acids of the same length. Calculation of the electrostatic contribution to the total free energy of binding reveals that for all oligoarginines only 25-30% has electrostatic origin. The remaining approximately 70-75% is nonelectrostatic, corresponding to hydrogen bonding and/or hydrophobic interactions. From the obtained data, a mechanism is suggested by which oligoarginines interact with anionic vesicles: (1) initial electrostatic interaction that is fast, nonspecific, and relatively weak; (2) nonelectrostatic interaction that is rate-limiting, stronger, and induces bilayer rigidification as well as release of aqueous contents from the vesicles. 相似文献
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P.J. Gardiner Julia L. Copas C. Schneider H.O.J. Collier 《Prostaglandins & other lipid mediators》1980,19(3):349-370
2-Decarboxy 2-hydroxymethyl prostaglandin E1 (TR4161) relaxed isolated guinea-pig trachea with about double and relaxed human isolated bronchial muscle with about one half the potency of PGE1. In conscious restrained cats an aerosol of TR4161 was about 100–1000 times less active than PGE1 in inducing tracheobronchial irritation. When given intravenously or by aerosol to the anaesthetised spontaneously breathing guinea-pig, TR4161 was approximately equipotent with PGE1 in inhibiting histamine-induced bronchoconstriction and in reducing basal inherent tone. The onset and duration of the bronchodilator effects of TR4161 administered intravenously, however, were significantly longer than those of PGE1. In conscious guinea-pigs, TR4161 by aerosol was approximately three times more potent than PGE1 in preventing histamine-induced convulsions, whereas only TR4161 was active in this test system when the test drugs were administered orally. These observations indicate that TR4161 might be therapeutically useful as a non-irritant prostaglandin bronchodilator in conditions of airway obstruction. 相似文献
16.
For the 6 years for which detailed data are readily available, estimates of the survival of emergent fry of Atlantic salmon, Salmo salar L., to the first and second autumns at a site on the Shelligan Burn are consistent with the dome-shaped Ricker model with about 11 emergent fry m−2 maximizing recruitment. The data are not satisfactorily fitted by the asymptotic Beverton and Holt model. A possible mechanism, which results from the observed inversely density-dependent growth, is discussed briefly. 相似文献
17.
Fujii R Shimonaka S Uchida N Gardiner AT Cogdell RJ Sugisaki M Hashimoto H 《Photosynthesis research》2008,95(2-3):327-337
Typical purple bacterial photosynthetic units consist of supra-molecular arrays of peripheral (LH2) and core (LH1-RC) antenna
complexes. Recent atomic force microscopy pictures of photosynthetic units in intact membranes have revealed that the architecture
of these units is variable (Scheuring et al. (2005) Biochim Bhiophys Acta 1712:109–127). In this study, we describe methods for the construction of heterologous photosynthetic
units in lipid-bilayers from mixtures of purified LH2 (from Rhodopseudomonas acidophila) and LH1-RC (from Rhodopseudomonas viridis) core complexes. The architecture of these reconstituted photosynthetic units can be varied by controlling ratio of added
LH2 to core complexes. The arrangement of the complexes was visualized by electron-microscopy in combination with Fourier
analysis. The regular trigonal array of the core complexes seen in the native photosynthetic membrane could be regenerated
in the reconstituted membranes by temperature cycling. In the presence of added LH2 complexes, this trigonal symmetry was
replaced with orthorhombic symmetry. The small lattice lengths for the latter suggest that the constituent unit of the orthorhombic
lattice is the LH2. Fluorescence and fluorescence-excitation spectroscopy was applied to the set of the reconstituted membranes
prepared with various proportions of LH2 to core complexes. Remarkably, even though the LH2 complexes contain bacteriochlorophyll
a, and the core complexes contain bacteriochlorophyll b, it was possible to demonstrate energy transfer from LH2 to the core complexes. These experiments provide a first step along
the path toward investigating how changing the architecture of purple bacterial photosynthetic units affects the overall efficiency
of light-harvesting. 相似文献
18.
Purification and characterization of human RNPS1: a general activator of pre-mRNA splicing. 总被引:1,自引:0,他引:1 下载免费PDF全文
A Mayeda J Badolato R Kobayashi M Q Zhang E M Gardiner A R Krainer 《The EMBO journal》1999,18(16):4560-4570
Biochemical purification of a pre-mRNA splicing activity from HeLa cells that stimulates distal alternative 3' splice sites in a concentration-dependent manner resulted in the identification of RNPS1, a novel general activator of pre-mRNA splicing. RNPS1 cDNAs, encoding a putative nucleic-acid-binding protein of unknown function, were previously identified in mouse and human. RNPS1 is conserved in metazoans and has an RNA-recognition motif preceded by an extensive serine-rich domain. Recombinant human RNPS1 expressed in baculovirus functionally synergizes with SR proteins and strongly activates splicing of both constitutively and alternatively spliced pre-mRNAs. We conclude that RNPS1 is not only a potential regulator of alternative splicing but may also play a more fundamental role as a general activator of pre-mRNA splicing. 相似文献
19.
Building protein interaction maps for Down's syndrome. 总被引:4,自引:0,他引:4
Katheleen Gardiner Muriel T Davisson Linda S Crnic 《Briefings in Functional Genomics and Prot》2004,3(2):142-156
Now that the complete sequences for human chromosome 21 and the orthologous mouse genomic regions are known, reasonably complete, conserved, protein-coding gene catalogues are also available. The central issue now facing Down's syndrome researchers is the correlation of increased expression of specific, normal, chromosome 21 genes with the development of specific deficits in learning and memory. Because of the number of candidate genes involved, the number of alternative splice variants of individual genes and the number of pathways in which these genes function, a pathway analysis approach will be critical to success. Here, three examples, both gene specific and pathway related, that would benefit from pathway analysis are discussed: (1) the potential roles of eight chromosome 21 proteins in RNA processing pathways; (2) the chromosome 21 protein intersectin 1 and its domain composition, alternative splicing, protein interactions and functions; and (3) the interactions of ten chromosome 21 proteins with components of the mitogen-activated protein kinase and the calcineurin signalling pathways. A productive approach to developing gene-phenotype correlations in Down's syndrome will make use of known and predicted functions and interactions of chromosome 21 genes to predict pathways that may be perturbed by their increased levels of expression. Investigations may then be targeted in animal models to specific interactions, intermediate steps or end-points of such pathways and the downstream - perhaps amplified - consequences of gene dosage directly assessed. Once pathway perturbations have been identified, the potential for rational design of therapeutics becomes practical. 相似文献
20.