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61.
The hyperfine shifted proton NMR spectrum of isoenzyme c of horseradish peroxidase indicated that one calcium ion is essential to the enzyme in maintaining the protein structure in the heme vicinity. 相似文献
62.
H Usui N Nishimura M Imazu T Imaoka N Konohara M Takeda 《European journal of biochemistry》1979,99(2):413-417
The phosphorylation of Ser-32, in addition to Ser-36 of H2B histone, stimulated the rate of Pi release from Ser-36 by the small form (Mr 31 000) of pig heart phosphoprotein phosphatase both in the absence and presence of 50 mM magnesium acetate. By phosphorylation at Ser-32, the Km value for Ser-36 phosphate in H2B histone was increased from 0.38 microM to 1.16 microM in the absence of magnesium acetate, but not significantly changed (from 37.4 microM to 26.2 microM) in the presence of magnesium acetate. With the large form (Mr 224000) of the phosphoprotein phosphatase, however, the phosphorylation at Ser-32 suppressed the rate of Pi release from Ser-36 both in the absence and presence of magnesium acetate. The Km value of the large form for Ser-36 phosphatase in H2B histone was nevertheless increased by phosphorylation at Ser-32, from 1.2 microM to 5.3 microM in the presence of magnesium acetate, but not changed (from 0.26 microM to 0.23 microM) in the absence of magnesium acetate. 相似文献
63.
Summary A production of macerating enzymes which liquefy and hydrolyze the mandarin orange peel was studied in a solid state cultivation of Aspergillus niger on wheat bran substrate. Solid state cultivation in a 2 drum fermenter capable of interchangeable operation under dynamic or static conditions were carried out maintaining the moisture content of the substrate at 32, 39, 46, 56, 67, and 74%. Biomass grown on the solid substrate was estimated on the basis of a constant value of glucosamine content of A. niger, 50 mg glucosamine/g cell. A linear relationship between oxygen uptake rate and growth rate observed in all the experiments gave an oxygen growth yield, YX/O, of 28.5 g cell/mol O2. The rate of macerating enzyme formation was also in proportion to the growth rate irrespective of the difference of the moisture content of the substrate.The enzyme accumulation on the solid substrate, the growth rate and oxygen uptake rate were maximum when the moisture content of the substrate was maintained at ca. 56% ascending from 32 to 56 and descending from 56 to 74. 相似文献
64.
1. The properties of 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile (SF 6847) were studied chemically and spectroscopically. Two molecular species of SF6847 were identified: the undissociated form (SFH; ?363, 10 mM?1) and the dissociated form (SF?; ?454, 35 mM?1). The pKa value of the molecule was determined to be 6.9.2. On the basis of these properties the interactions of SF6847 with liposomes and valinomycin · K+ were studied. The partition constants of SFH (Knp and SF? (K?p) to liposomes were determined separately; Knp was 56 mM?1 and was independent of the pH of the medium, whereas K?p dependend greatly on the pH, being 1.2 mM?1 at pH 7.0 and 2.9 mM?1 at pH 8.0. Using these values, the partition constant of total SF6847 (Kp) was calculated and found to be essentially the same as that calculated from the kinetics of proton uptake. It was concluded that the amount of SF? bound to liposomes is rate limiting for proton uptake.3. The effects of membrane potential on partition constants were studied. The K?p decreased greatly upon generation of a membrane potential negative inside the liposomes but increased upon generation of a membrane potential positive inside the liposomes.4. The interaction of SF6847 with valinomycin in aqueous solution and in liposomes was demonstrated only in the presence of potassium ion. Potassium ion could not be replaced by sodium ion. Evidence was obtained for the formation of the ternary complex valinomycin · K+ · SF? in liposomes and in hexane. It was concluded that SF? became more soluble in the liposomal membranes on formation of this ternary complex. All these results support our proposed mechanism for the proton uptake cycle (Yamaguchi, A. and Anraku, Y. (1978) Biochim. Biophys. Acta 501, 136–149). 相似文献
65.
The specificity of sweet-potato beta-amylase in the vicinity of the phosphate ester groups was studied by determining the structures of the phosphorylated oligosaccharides (alpha-phosphodextrin and beta-limit-alpha-phosphodextrin) formed by its action on potato starch. The beta-limit-alpha-phosphodextrin was separated by chromatography on Dowex-1 (HCOO?) resin into three fractions that were distinguishable by the d.p. and by the ratio of d-glucose 6-phosphate residues to total organic phosphate. Each fraction contained linear molecules having one phosphate ester group that was not located at the reducing or non-reducing terminals. The smallest phosphodextrin was 62-phosphorylmaltotriose. It was deduced that beta-amylase hydrolysed (1→4)-α-d linkages from the non-reducing end until one or two d-glucosyl residues remained attached to the phosphorylated residue, depending on whether there was originally an odd or even number of glucosyl residues on the non-reducing side of the phosphorylated residue. 相似文献
66.
Shiro Ohki Yoshimasa Nishigaki Katsuhiro Imaki Masayasu Kurono Fumio Hirata Toshio Hanyu Nobuhiko Nakazawa 《Prostaglandins & other lipid mediators》1976,12(2):181-186
Radioimmunoassay technique for measuring 5α,7α-dihydroxy-11-keto-tetranorprosta-1,16-dioic acid, the main urinary metabolite of PGF1α and PGF2α (PGF2α-MUM), was further improved.It was postulated based on some experimental data that the PGF2α-MUM exists in the urine mostly as dioic acid form, not as δ-lactone formThe daily excretion of PGF2α-MUM in men ranged from 14.43 μg to 36.14 μg and in women from 5.21 μg to 14.25 μg. 相似文献
67.
Keishi Abe Yoichi Otsuka Minoru Yasujima Satoru Ciba Masahide Seino Nobuo Irokawa Kaoru Yoshinaga Fumio Hirata Shiro Ohki Nobuhiko Nakazawa Toshio Hanyu 《Prostaglandins & other lipid mediators》1976,12(5):843-848
The excretion rates of main urinary metabolite of PG F2α were measured radioimmunologically in 4 healthy persons and in 13 essential hypertensives. The resting values were 9.3±0.73 in the former and 10.4±2.17 ng/min in the latter. There was no significant differences between them. The excretion of the metabolite decresed prominently after the administration of furosemide. The percent decrease was 57% in healthy persons and 70% in essential hypertension. The percent result supports that furosemide inhibit the catabolism of PG F2α. 相似文献
68.
Shiro Kobayashi 《Population Ecology》1976,17(2):243-254
Summary A mathematical model of the species-area relation is described for a group of limited species. This model is a modification
of that proposed earlier (Kobayashi, 1975), being assumed that the limited species are expected to occur in a habitat under consideration. The model equation
gives a sigmoid species-log area curve implying that few rare species are found in a group of species. The good agreement
between observation and this model is exemplified with the data of plant and arthropod communities. The implication of parameters
involved are examined in connection with those of the preceding model, and the underlying ecology of the model is discussed.
Contribution from the Laboratory of Applied Zoology, Yamagata University, No. 83. 相似文献
69.
Removal of the ganglion or severance of the nerve cords at the thorax in mature larvae of the swallowtail, Papilio xuthus, induced systemic distension of the body by swallowing excess air. Such a distension, however, was never induced by simultaneous extirpation of the brain, suboesophageal ganglion, or frontal ganglion, or by severance of the recurrent nerve. Removal of an abdominal ganglion induced distension of the posterior part of the body accompanied by shrinkage of the anterior part. The latter phenomenon appears to be induced by a different mechanism from that of systemic distension. 相似文献
70.
Qizhi Fang Pamela Y. Mok Anila E. Thomas Daniel J. Haddad Shereen A. Saini Brian T. Clifford Neel K. Kapasi Olivia M. Danforth Minako Usui Weisheng Ye Emmy Luu Rikki Sharma Maya J. Bartel Jeremy A. Pathmanabhan Andrew A. S. Ang Richard E. Sievers Randall J. Lee Matthew L. Springer 《PloS one》2013,8(4)
Pleiotrophin (PTN) is a growth factor with both pro-angiogenic and limited pro-tumorigenic activity. We evaluated the potential for PTN to be used for safe angiogenic gene therapy using the full length gene and a truncated gene variant lacking the domain implicated in tumorigenesis. Mouse myoblasts were transduced to express full length or truncated PTN (PTN or T-PTN), along with a LacZ reporter gene, and injected into mouse limb muscle and myocardium. In cultured myoblasts, PTN was expressed and secreted via the Golgi apparatus, but T-PTN was not properly secreted. Nonetheless, no evidence of uncontrolled growth was observed in cells expressing either form of PTN. PTN gene delivery to myocardium, and non-ischemic skeletal muscle, did not result in a detectable change in vascularity or function. In ischemic hindlimb at 14 days post-implantation, intramuscular injection with PTN-expressing myoblasts led to a significant increase in skin perfusion and muscle arteriole density. We conclude that (1) delivery of the full length PTN gene to muscle can be accomplished without tumorigenesis, (2) the truncated PTN gene may be difficult to use in a gene therapy context due to inefficient secretion, (3) PTN gene delivery leads to functional benefit in the mouse acute ischemic hindlimb model. 相似文献