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61.
F Nato C Goulut R Bourrillon H Van Halbeek J F Vliegenthart 《European journal of biochemistry》1986,159(2):303-308
Glycoprotein MII2, the major cell surface glycoprotein (molecular mass 110 kDa) of Zajdela hepatoma ascites cells, contains about 25 O-glycosidic oligosaccharide chains per molecule. They were released as oligosaccharide-alditols by alkaline borohydride treatment of MII2, and purified by gel filtration on Bio-Gel P-6 followed by high-voltage paper electrophoresis. Four oligosaccharide-alditol fractions (A-D) were obtained in relative yields of 8:6:3:3. The structure of the components of fractions A-C was determined by 500-MHz 1H-NMR spectroscopy in combination with sugar composition analysis, to be as follows. (A) NeuAc alpha(2----3)Gal beta(1----3)[NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)]GalNAc-ol; (B1) NeuAc alpha(2----3)Gal beta(1----3)[Gal beta(1----4)GlcNAc beta(1----6)]GalNAc-ol; (B2) Gal beta(1----3)[NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)]GalNAc-ol; (C) NeuAc alpha(2----3)Gal beta(1----3)GalNAc-ol. On the basis of sugar composition and characteristics on Bio-Gel P-6 filtration, paper electrophoresis and thin-layer chromatography, the structure of the carbohydrate component of fraction D is proposed to be as follows. (D) NeuAc alpha(2----3)Gal beta(1----3)[NeuAc alpha(2----6)]GalNAc-ol 相似文献
62.
H. Van Halbeek L. Dorland J.F.G. Vliegenthart G. Spik A. Cheron J. Montreuil 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,675(2):293-296
The elucidation of the structures of two carbohydrates units, N-glycosidically linked to an asparagine residue of bovine lactotransferrin, is described. These carbohydrate structures are of the oligomannoside type and contain eight or nine mannose residues, respectively. The potency of 500 MHz 1H-NMR spectroscopy in primary structure determination of two closely related carbohydrate chains present in a mixture is demonstrated. This implies that 500 MHz 1H-NMR spectroscopy can disclose microheterogeneity which is almost untraceable using other approaches. 相似文献
63.
Structural studies on phosphorylated oligosaccharides derived from yeast mannan by 1H(31P) relayed spin-echo difference spectroscopy (RESED) 总被引:1,自引:0,他引:1
P de Waard J F Vliegenthart Y Kozutsumi T Kawasaki I Yamashina 《The Journal of biological chemistry》1989,264(21):12141-12144
Phosphorylated and nonphosphorylated tri- and tetrasaccharides were isolated from yeast mannan and analyzed by 500-MHz 1H NMR spectroscopy. Relayed spin-echo difference spectroscopy (RESED) was used to reveal subspectra of the phosphorylated residues. In this way the attachment position of the phosphate group could be established. The structures of the phosphorylated compounds turned out to be (Formula: see text) and (Formula: see text) RESED spectroscopy has proved to be a suitable method in analyzing low amounts of phosphorylated oligosaccharides. 相似文献
64.
65.
Paul B. van Seeventer Johannes A.L.M. van Dorst John F. Siemerink Johannis P. Kamerling Johannes F.G. Vliegenthart 《Carbohydrate research》1997,300(4):2401-373
A useful method for the preparation of differently functionalized sulfide spacer-arm glycosides is presented. Several protected allyl glycosides were variously elongated via a radical addition reaction with pentanethiol, methyl 3-mercaptopropionate, or 2-mercaptoethanol. The hydroxyl function of protected 3-(2-hydroxyethylthio)propyl glycosides was subsequently transformed into an azide function. 相似文献
66.
Extreme differences in rates of molecular evolution of foraminifera revealed by comparison of ribosomal DNA sequences and the fossil record 总被引:8,自引:3,他引:5
Pawlowski J; Bolivar I; Fahrni JF; de Vargas C; Gouy M; Zaninetti L 《Molecular biology and evolution》1997,14(5):498-505
Foraminifera have one of the best known fossil records among the
unicellular eukaryotes. However, the origin and phylogenetic relationships
of the extant foraminiferal lineages are poorly understood. To test the
current paleontological hypotheses on evolution of foraminifera, we
sequenced about 1,000 base pairs from the 3' end of the small subunit rRNA
gene (SSU rDNA) in 22 species representing all major taxonomic groups.
Phylogenies were derived using neighbor- joining, maximum-parsimony, and
maximum-likelihood methods. All analyses confirm the monophyletic origin of
foraminifera. Evolutionary relationships within foraminifera inferred from
rDNA sequences, however, depend on the method of tree building and on the
choice of analyzed sites. In particular, the position of planktonic
foraminifera shows important variations. We have shown that these changes
result from the extremely high rate of rDNA evolution in this group. By
comparing the number of substitutions with the divergence times inferred
from the fossil record, we have estimated that the rate of rDNA evolution
in planktonic foraminifera is 50 to 100 times faster than in some benthic
foraminifera. The use of the maximum-likelihood method and limitation of
analyzed sites to the most conserved parts of the SSU rRNA molecule render
molecular and paleontological data generally congruent.
相似文献
67.
68.
JF Yuan SJ Zhang O Jafer RA Furlong OE Chausiaux CA Sargent GH Zhang NA Affara 《BMC microbiology》2009,9(1):246
Background
Pseudorabies virus (PRV) is an alphaherpesviruses whose native host is pig. PRV infection mainly causes signs of central nervous system disorder in young pigs, and respiratory system diseases in the adult. 相似文献69.
Background
Most studies examining the commensal human oral microbiome are focused on disease or are limited in methodology. In order to diagnose and treat diseases at an early and reversible stage an in-depth definition of health is indispensible. The aim of this study therefore was to define the healthy oral microbiome using recent advances in sequencing technology (454 pyrosequencing). 相似文献70.