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K Sakai T Kobayashi T Komuro S Nakamura K Mizuta Y Sakanoue E Hashimoto H Yamamura 《Biochemistry international》1987,14(1):63-70
Phosphorylation of clupeine sulfate by purified rat brain calcium-activated, phospholipid-dependent protein kinase (protein kinase C) was studied. In the absence of Ca2+, phosphatidylserine and diolein markedly stimulated its phosphorylation. However Ca2+ did not stimulate but inhibit this phosphorylation about 30% in the presence of phospholipids. Random polymer (Arg, Ser) 3:1 and (Lys, Ser) 3:1 could be phosphorylated by protein kinase C. In the presence of phospholipids Ca2+ is not needed for the phosphorylation of polymer (Arg, Ser) 3:1, while Ca2+ is necessary for polymer (Lys, Ser) 3:1. Non-requirement of Ca2+ on clupeine phosphorylation by protein kinase C is briefly discussed. 相似文献
23.
Accumulation of CK-MM is impaired in innervated and contracting cultured muscle fibers of Duchenne muscular dystrophy patients 总被引:1,自引:0,他引:1
No specific abnormalities have been reproducibly manifested in aneurally cultured muscle of Duchenne muscular dystrophy (DMD) patients. We now report that the accumulation of the muscle-"specific" isozyme of creatine kinase (CK-MM) was significantly and preferentially impaired in long-term innervated contracting muscle fibers cultured from 4 DMD patients (DMD-InnCMFs) compared to: i) their noninnervated sister-cultured muscle fibers, and ii) innervated contracting control cultured human muscle fibers (Control-InnCHMFs). Accumulation of other muscle-"specific" isozymes (MSIs), viz. glycogen phosphorylase, phosphoglycerate mutase, and lactic dehydrogenase, was not significantly impaired. We have not observed preferentially-impaired CK-MM accumulation in any Control-InnCHMFs from 22 patients (children and adults) with a variety of neuromuscular diseases. There was no apparent difference between DMD-InnCMFs and Control InnCHMFs regarding: acceptance of innervation; neuronally-driven, virtually continuous muscle-fiber contractions; characteristic myofiber organization by phase-contrast microscopy, and increased longevity of the innervated fibers. 相似文献
24.
Tanaka Osamu; Nasu Yutaka; Sonoyama Akiko; Maehara Yasuko; Kobayashi Takako; Nawafune Hidemi; Kugimoto Mamoru 《Plant & cell physiology》1987,28(4):697-702
The flowering of Lemna paucicostata 6746 grown on 14-h photoperiodwas enhanced by the addition of high concentrations of ironto the medium, which also increased the endogenous iron concentration.The addition of asparagine, aspartate, glutamate, -alanine,glycine or serine to the medium also increased the endogenousiron level, resulting in the promotion of flowering. In contrast,the addition of cysteine, cystine, glutamine, arginine, threonineor phenylalanine lowered the endogenous iron level, resultingin the inhibition of flowering. Glycine and asparagine added to the medium during an inductive96-h dark period did not promote iron uptake and had no effecton flowering, but when added during the subsequent 120-h lightperiod, they promoted both iron uptake and flowering response.The increase in the endogenous iron level seems to favor floraldevelopment rather than induction of photoperiodic floweringof Lemna paucicostata 6746. (Received September 8, 1986; Accepted March 31, 1987) 相似文献
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27.
Temperature-sensitive (ts) mutants of rat 3Y1 fibroblasts representing four separate complementation groups (3Y1tsD123, 3Y1tsF121, 3Y1tsG125, and 3Y1tsH203) are arrested mainly in the G1 phase when cells of randomly proliferating population at 33.8 degrees C are shifted to 39.8 degrees C (temperature arrest). We examined the time lag of the cellular entry into the S phase after release at 33.8 degrees C, both from the temperature arrest and from the arrest at 33.8 degrees C at a confluent cell density (density arrest). In the temperature-arrested cells, as the duration of temperature arrest increased, the time lag of entry into S phase after shift down to 33.8 degrees C was prolonged, in all four mutants. These observations suggest that the four different functional lesions, each causing arrest in the G1 phase, are also responsible for prolongation of the time lag of entry into the S phase in cells arrested in the G1 phase. The prolongation of the time lag in the temperature-arrested cultures was accelerated at a higher cell density, in medium supplemented with a lower concentration of serum, and at a higher restrictive temperature. In the density-arrested cells, as the duration of pre-exposure to 39.8 degrees C was increased, the time lag of entry into S phase at 33.8 degrees C after release from the arrest was drastically prolonged, in all four mutants. In 3Y1tsF121, 3Y1tsG125, and 3Y1tsH203, when the density-arrested cells were prestimulated by serum at 39.8 degrees C for various periods of time, the time lag of entry into S phase after release from the density arrest at 33.8 degrees C was initially shortened, and then, prolonged progressively as the period of prestimulation increased. These findings, taken together with other data, show that all four ts defects affect cells in states ranging from the deeper resting to mid- or late-G1 phase. It is suggested that events represented by these four mutants are required for entry into the S phase and normally operate in parallel but not in sequence in cells in states ranging from the deeper resting to the mid- or late-G1 phases, though they may affect each other. 相似文献
28.
Acyl-peptide hydrolase, which catalyzes the hydrolysis of an N-terminally acetylated peptide to release an N-acetylamino acid, was isolated from rat liver and found to be N-terminally blocked. The kinetics of the hydrolysis of acetyl (Ac)-Ala-Ala, Ac-Ala-Ala-Ala, acetylalanine p-nitroanilide, and acetylalanine beta-naphthylamide were investigated. The Km values were between 1 and 9 mM, and the Vmax values were between 100 and 500 nmol/min/micrograms of enzyme. The enzyme activity toward acetylalanine p-nitroanilide and acetylalanine beta-naphthylamide was activated by the presence of Cl- and SCN- at concentrations between 0.1 and 0.5 M. By contrast, the activity toward Ac-Ala-Ala and Ac-Ala-Ala-Ala was inhibited by these anions. Among a series of divalent cations, Zn2+ was demonstrated to be the most potent inhibitor. The enzyme was inactivated by the addition of diisopropyl fluorophosphate, diethyl pyrocarbonate. Woodward's Reagent K, and glycine methyl ester/carbodiimide. Titration by diisopropyl fluorophosphate showed 0.7 mol of active serine/mol of enzyme subunit, which was confirmed by the incorporation of [3H]diisopropyl fluorophosphate into the enzyme. Acetylalanine chloromethyl ketone inactivated the enzyme following pseudo-first order kinetics; and Ac-Ala, a competitive inhibitor, protected the enzyme from this inactivation. Acyl-peptide hydrolase appears to be a serine protease utilizing a charge relay system involving serine, histidine, and, probably, a carboxyl group(s). Two series of acetyl dipeptides, acetylamino acid p-nitroanilides and acetylamino acid beta-naphthylamides, were prepared in order to determine enzyme specificity. The enzyme preferentially removed Ac-Ala, Ac-Met, and Ac-Ser, the most common acetylated N-terminal residues (Persson, B., Flinta, C., von Heijne, G., and J?rnvall, H. (1985) Eur. J. Biochem. 152, 523-527). The enzyme was shown to be useful for deblocking peptides (e.g. alpha-melanocyte-stimulating hormone and acetyl-renin substrate), and the crude enzyme/substrate mixtures were amenable to direct protein sequence analysis. 相似文献
29.
Chemical characterization of recombinant human leukocyte interferon A using fast atom bombardment mass spectrometry 总被引:2,自引:0,他引:2
T Takao M Kobayashi O Nishimura Y Shimonishi 《The Journal of biological chemistry》1987,262(8):3541-3547
Proteolytic digests of biologically active fractions of recombinant human leukocyte interferon A expressed in large quantities in Escherichia coli were analyzed by fast atom bombardment mass spectrometry and high-performance liquid chromatography. The values observed in the mass spectra of digests of the major fraction of recombinant human leukocyte interferon A with trypsin and Staphylococcus aureus protease V8 accounted for 93% of the amino acid sequences of human leukocyte interferon A predicted from the nucleotide sequence of the gene encoding the protein, indicating that the major fraction of recombinant human leukocyte interferon A was expressed with the same amino acid sequence as that translated from the nucleotide sequence of the gene encoding the protein. Mass spectrometry of proteolytic digests of two minor fractions of recombinant human leukocyte interferon A and mass and amino acid analyses of their high-performance liquid chromatography fractions showed that the amino group of the N-terminal amino acid residue of interferon was in part acetylated, and the Cys-1 and Cys-98 residues were oxidized to cysteic acid or linked to glutathione. These findings suggest that amino acid residues in recombinant proteins prepared in large quantities in E. coli are modified post-translationally. 相似文献
30.
Characterization of tumor-associated fucogangliosides from PC 12 pheochromocytoma cells 总被引:3,自引:0,他引:3
T Ariga K Kobayashi Y Kuroda R K Yu M Suzuki H Kitagawa F Inagaki T Miyatake 《The Journal of biological chemistry》1987,262(29):14146-14153
PC 12h pheochromocytoma cells were subcutaneously transplanted into rat. We found the transplanted tumors accumulated some fucogangliosides associated with PC 12 cells. These gangliosides were isolated and purified by DEAE-Sephadex A-25 and Iatrobeads column chromatographies. Their structures were determined by fast atom bombardment mass spectrometry, proton nuclear magnetic resonance spectrometry, permethylation study, and sequential degradation using various exoglycosidases and mild acid hydrolysis. Two tumor-associated fucogangliosides were found to possess the blood group B determinant as follows: G6: IV2Fuc alpha, IV3Gal alpha, II3NeuAc, GgOse4Cer; G11: IV2Fuc alpha, IV3Gal alpha, II3 (NeuAc)2, GgOse4Cer. A ganglioside with the similar structure as ganglioside G6 was isolated from rat hepatoma cells (Holmes, E.H., and Hakomori, S-I. (1982) J. Biol. Chem. 257, 7698-7703). However, ganglioside G11 has not previously been reported in the literature. These fucogangliosides reacted with the monoclonal antibody prepared by immunizing mice with PC 12h cells. Other fucogangliosides were also found to accumulate in the transplanted tumor tissues. They were identified as fucosyl-GM1 and fucosyl-GDlb. These fucogangliosides did not react with the monoclonal antibody against PC 12h cells. 相似文献