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31.
32.
Anthony G. Lee Kate A. Dalton Richard C. Duggleby J. Malcolm East Anthony P. Starling 《Bioscience reports》1995,15(5):289-298
Effects of lipid structure on the function of the Ca2+-ATPase of skeletal muscle of sarcoplasmic reticulum are reviewed. Binding of phospholipids to the ATPase shows little specificity. Phosphatidylcholines with short (C14) or long (C24) fatty acyl chains have marked effects on the activity of the ATPase, including a change in the stoichiometry of Ca binding. Low ATPase activity in gel phase lipid follows from low rate of phosphorylation. Phosphatidylinositol 4-phosphate increases ATPase activity by increasing the rate of dephosphorylation of the phosphorylated ATPase. Stimulation is not seen with other anionic phospholipids; phosphatidic acid decreases ATPase activity in a Mg2+-dependent manner.Abbreviations di(C141)PC
dimyristoleoylphosphatidycholine
- di(C160)PC
dipalmitoylphosphatidylcholine
- di(C181)PC
dioleoylphosphatidylcholine
- di(Br2C180)PC
dibromostearoylphosphatidylcholine
- di(C241)PC
dinervonylphosphatidylcholine
- di(C181)PA
dioleoylphosphatidic acid
- di(C181)PE
dioleoylphosphatidylethanolamine
- Ptdlns
phosphatidylinositol
- PtdIns-4P
phos-phatidylinositol 4-phosphate 相似文献
33.
Israel Zilbermann Maya Winnik Dalia Sagiv Amira Rotman Haim Cohen Dan Meyerstein 《Inorganica chimica acta》1995,240(1-2):503-514
The effects of N-alkylation on the redox potential of the couples NiLi2+/NiLi+, L = tetraaza-14-membered-macrocyclic ligands, and on the properties of the monovalent nickel complexes in aqueous solutions are reported for 14 complexes. The spectra and lifetimes of the NiLi+ complexes are reported. The self-exchange rates for the couples NiLi2+/NiLi+ were determined. Two of the ligands were synthesized for the first time for this study. Cyclic voltammetry and pulse radiolysis were used. The results point out that: (i) N-alkylation always shifts the redox potential to a less cathodic one; this effect stems to a large degree from the decrease in the solvation energy of the complex caused by the N-alkylation of the ligand. (ii). The lifetime of the monovalent complexes is not linearly related to the redox potential of the NiLi2+/NiLi+ couples. (iii) The NiLi+ complexes exist in several isomeric forms; the rate of the isomerization depends on the structure of the ligand. (iv) Different isomers of NiLi+ may be formed when the complex NiLi2+ is reduced by different reagents; therefore, the pulse-radiolytically formed NiLi+ complexes might have different properties than those formed electrochemically. 相似文献
34.
Human medulloblastoma gangliosides 总被引:2,自引:0,他引:2
To establish a model system for the study of ganglioside metabolismof the human brain tumor, medulloblastoma, we have chemicallycharacterized the gangliosides of the Daoy cell line. Thesecells contain a high concentration of gangliosides (143 ±13 nmol LBSA/108 cells). The major species have been structurallyconfirmed to be GM2 (65.9%), GM3 (13.0%), and GDla (10.3%).Isolation of individual gangliosides homogeneous in both carbohydrateand ceramide moieties by reversed-phase HPLC and analysis bynegative-ion fast atom bombardment collisionally activated dissociationtandem mass spectrometry have allowed us to unequivocally characterizeceramide structures. In the case of GM2, 10 major ceramide subspecieswere identified: d18:1-hC16:0, d18:1-C16:0, d18:0-C16:0, d18:1-C18:0,d18:1-C20:0, d18:1-C22:0, d18:2-C24:1, d18: 1-C23:1, d18:1-C24:1,and d18:1-C24:0. Taken together with previous studies, thesefindings in human medullo-blastoma cells support the view thathigh expression and marked heterogeneity of ceramide structureare general characteristics of tumor gangliosides, moleculeswhich are shed by the tumor cells and which are biologicallyactive in vivo. medulloblastoma gangliosides ceramide structure HPLC mass spectrometry 相似文献
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36.
H. G. de Vries J. M. Collée W. P. Meeuwsen H. Scheffer L. P. Ten Kate 《Human genetics》1995,95(5):575-576
Number and sex of offspring were determined in a group of 7,841 randomly selected blood donors who were screened for the F508 mutation. We did not find any evidence for differences in number or sex ratio of offspring between F508 carriers and non-carriers. 相似文献
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To determine if neural crest cells are pluripotent and establish whether differentiation occurs in the absence of noncrest cells, a cell culture method was devised in which differentiation could be examined in clones derived from single, isolated neural crest cells. Single neural crest cells, which were isolated before the onset of in vivo migration, gave rise to three types of clones: pigmented, unpigmented, and mixed. Pigmented clones consisted of melanocytes only, whereas some unpigmented cells in mixed and unpigmented clones contained catecholamines, identifying them as adrenergic cells. Extracellular matrix derived from quail somite or chick skin fibroblast cultures stimulated adrenergic differentiation and axon formation. These results demonstrate for the first time the existence of pluripotent quail neural crest cells that give rise to at least two progeny, melanocytes and neuronal cells. They also suggest that continuous direct interactions with noncrest cells are not required for the differentiation of these two cell types. However, components of the extracellular matrix derived from noncrest cells may play an important role in expression of the adrenergic phenotype. 相似文献
39.
J E De Vries F H Kornips J Wiegant P M Moerkerk N Senden B Schutte J P Geraedts F T Bosman J Ten Kate 《The journal of histochemistry and cytochemistry》1992,40(7):1053-1058
We describe the combination of hot banding with fluorescence in situ hybridization as a rapid and efficient method to identify integration sites of transfected DNA sequences in chromosomes. As a test system we used SW480 EJ2, a clonal cell line obtained after transfection of SW480 with pSV2neoEJ, a plasmid containing a point-mutated, c-Ha-RAS oncogene. Nick-translated probes were compared with random primed-labeled probes to evaluate their relative efficiency in fluorescence in situ hybridization. The fluorescence signals were quantified in interphase nuclei by confocal scanning laser microscopy. Nick-translated probes were found to yield better results. Hot banding followed by fluorescence in situ hybridization localized the integration site of pSV2neoEJ in SW480 EJ2 at the site of a translocation on a marker chromosome Xp+. The combination of fluorescence in situ hybridization and hot banding can be used to (a) rapidly and efficiently analyze integration sites in large numbers of transfectants, (b) assess the clonality of transfected cell lines, and (c) localize the site of integration of transfected genes in the recipient genome. 相似文献
40.