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41.
42.
YM175, a new bisphosphonate, increases serum 1,25-dihydroxyvitamin D in rats via stimulating renal 1-hydroxylase activity 总被引:1,自引:0,他引:1
Y Nagao Y Ishitobi H Kinoshita S Fukushima H Kawashima 《Biochemical and biophysical research communications》1991,180(3):1172-1178
Effect of YM175, a new bisphosphonate, on vitamin D metabolism was studied in rats. When animals were treated with the compound, serum 1,25-dihydroxyvitamin D increased in a dose dependent manner. The effect was also detected in thyroparathyroidectomized animals. The effect appears to be due to the stimulation of renal production of the hormone, since renal 1-hydroxylase was also elevated in these animals. However, when kidneys were incubated with YM175 and then renal 1-hydroxylase activity was examined, the enzyme activity was not different from that of non-treated control kidney. We conclude therefore that YM175 indirectly stimulates renal 25-hydroxyvitamin D-1-hydroxylase by increasing circulating parathyroid hormone via an unknown mechanism independent of parathyroid hormone. This is the first direct demonstration of increase in the renal production of 1,25-dihydroxyvitamin D resulting from bisphosphonate treatment. 相似文献
43.
44.
Kunshan Gao Yusho Aruga Kozi Asada Toshiaki Ishihara Toru Akano Masataka Kiyohara 《Journal of applied phycology》1991,3(4):355-362
Leafy thalli of the red algaPorphyra yezoensis Ueda, initiated from conchospores released from free-living conchocelis, were cultured using aeration with high CO2. It was found that the higher the CO2 concentration, the faster the growth of the thalli. Aeration with elevated CO2 lowered pH in dark, but raised pH remarkably in light with the thalli, because the photosynthetic conversion of HCO 3 ? to OH? and CO2 proceeded much faster than the dissociation of hydrated CO2 releasing H+. Photosynthesis of the alga was found to be enhanced in the seawater of elevated dissolved inorganic carbon (DIC, CO2 + HCO 3 ? + CO 3 ? ). It is concluded that the increased pH in the light resulted in the increase of DIC in the culture media, thus enhancing photosynthesis and growth. The relevance of the results to removal of atmospheric CO2 by marine algae is discussed. 相似文献
45.
Identity of a tumor cytotoxic factor from human fibroblasts and hepatocyte growth factor 总被引:20,自引:0,他引:20
K Higashio N Shima M Goto Y Itagaki M Nagao H Yasuda T Morinaga 《Biochemical and biophysical research communications》1990,170(1):397-404
Human embryonic lung diploid fibroblast, IMR-90 cells secreted a tumor cytotoxic factor. The fibroblast-derived tumor cytotoxic factor (F-TCF) has a cytotoxic activity to Sarcoma 180 and a cytostatic and degenerative activities to KB cells. F-TCF has been purified about 540,000-fold with 23.3% recovery from 75 liters of the conditioned medium containing 5% newborn calf serum. The purified F-TCF is a basic glycoprotein with isoelectric point values of 7.4 to 8.6. It was stable in the pH range from 6.0 to 9.0 and was stable at the heating temperature of 60 degrees C for 10 min, but completely inactivated by reducing it with 2-mercaptoethanol. F-TCF has molecular weight of 76 to 80 kD on SDS-PAGE under non-reducing conditions and is a heterodimer consisting of a large alpha subunit with 52 to 56 kD and a small beta subunit with 30 to 34 kD. F-TCF was identified as one of human hepatocyte growth factors by the physicochemical properties including N terminal and a few internal amino acid sequences. We have confirmed that F-TCF has an ability to dramatically stimulate DNA synthesis in adult rat hepatocytes in the low dose range of 1 to 10 ng/ml. 相似文献
46.
47.
S Nagao S Matsuki H Kanoh T Ozawa K Yamada Y Nozawa 《The Journal of biological chemistry》1990,265(11):5926-5929
Tetrahymena calmodulin (CaM) differs from mammalian CaM in its ability to activate Tetrahymena guanylate cyclase. Of 12 differences in amino acid sequence, two occur near the carboxyl terminus (Gln-143----Arg and Thr-146----deletion). To investigate the functional significance of the carboxyl-terminal region in activation of the guanylate cyclase, three mutated CaMs were engineered by using cassette mutagenesis of rat CaM cDNA: Gln-143----Arg (CaM.A), Thr-146----deletion (CaM.D), and Gln-143----Arg/Thr-146 deletion (CaM.AD). Recombinant wild type CaM (wCaM), CaM.A, CaM.D, and CaM.AD were indistinguishable in their ability to activate cyclic AMP phosphodiesterase. The two mutated CaMs (CaM.A and CaM.AD) with the Gln-143 replacement activated guanylate cyclase of Tetrahymena plasma membrane in the presence of Ca2+, with the maximal activation being half of that produced by Tetrahymena CaM. In contrast, neither CaM.D nor wCaM could stimulate the cyclase activity. A CaM antagonist, W-7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide), prevented the cyclase activation by either Tetrahymena CaM, CaM.A, or CaM.AD. Thus, we conclude that Arg-143 is in a region of the molecule involved in activation of Tetrahymena guanylate cyclase. The data also suggest that the cyclase activation by Tetrahymena CaM requires complex macromolecular interactions between the entire CaM molecule and the enzyme. 相似文献
48.
Yoshiteru Harada Kunio Tanaka Yasushiro Uchida Akinori Ueno Sachiko Oh-ishi Yamashita Kowa Masataka Ishibashi Hiroshi Miyazaki Makoto Katori 《Prostaglandins & other lipid mediators》1982,23(6)
Injection of γ-carrageenin into t he pleural cavity of rats caused the accumulation of the pleural exudate. When levels of prostaglandins (PGs) and thromboxane (TX) B2 were quantified by gas chromatography-mass spectrometry as their methyl ester (ME)-dimethyllisopropylsilyl (DMiPS) ether or ME-methoxine-DMiPS ether derivatives, 6-keto-PGF1α reached the maximum at 1 hr after carrageenin, then PGE2 and TXB2 showed peaks at 3 hr and waned off before 9 hr. he PGF2α level was kept low, but PGD2, PGE1 and PGF1α were not detected. Aspirin (100 mg/kg, i.p.) significantly decreased the PG and TXB2 levels and suppressed the rate of plasma exudation until 5 hr, but did not at 7 hr, when it was measured by the amount of exuded pontamine sky blue injected intravenously. OKY-025 (300 mg/kg, i.p.), a selective TXA synthetase inhibitor, and tranylcypromine (20 mg/kg, i.p.), a PGI synthetase inhibitor, could not extensively inhibit the accumulation of the exudate. These results suggest that the cyclooxygenase products of arachidonic acid, particularly PGE2, definitely play an important role in the exudation during the first 5 hr. 相似文献
49.
Tadami Nagao Mitsumoto Komatsuda Kunihiko Yamauchi Shigeru Arimori 《Journal of cellular physiology》1981,108(2):155-161
In a liquid culture of human bone marrow, the development of fibroblast colonies takes place on days 6 to 9. Twenty percent fetal calf serum is used as the stimulus for fibroblast colony growth. Human bone marrow cells are plated as 2 × 105 cells in the culture. Normal human bone marrow yields 47 ± 4 fibroblasts colonies per 2 × 105 cells plated. Bone marrow fibroblast cultures using agar or methylcellulose restrict colony formation. Marked colony suppression was observed in acute leukemia, and a discrete colony number was observed in hypoplastic anemia. This fibroblast culture method should be applied to a larger number of patients to determine whether it has a pathognomonic value and clinical significance. 相似文献
50.
Sumio Iwai Kazuo Nakata Teruyoshi Nagao Nobumaro Kawashima Susumu Matsuyama 《Planta》1981,152(5):478-480
Nine plants were produced from anthers of a somatic hybrid which had been obtained by fusion of Nicotiana tabacum L. and N. rustica L. protoplants. As determined by electrofocusing, the Fraction I protein of the original somatic hybrid had largesubunit polypeptides exclusively of the N. tabacum type. Two of the plants regenerated from anthers contained Fraction-I-protein large subunits exclusively of the N. rustica type. Since each plant was regenerated from a single cell, the somatic hybrid must have had cells containing both the N. tabacum and N. rustica chloroplast genome although the latter was not expressed. Possibilities to account for this non-expression of a chloroplast genome in the somatic hybrid are discussed. 相似文献