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921.
922.
Masako Kimura Kunio Kobayashi Mitsuo Hata Akira Matsuoka 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1980,183(4)
A method for the routine clinical examination of serum gliclazide by high-performance liquid chromatography (HPLC) on a column packed with a macroporous anion-exchange resin, Diaion CDR-10, was developed. The elution was performed with acetonitrile—methyl alcohol—1.2 M ammonium perchlorate (4:3:7, v/v/v) at a flow-rate of 0.4 ml/min. The retention time of gliclazide was 15 min. It seems that the retention mechanism of gliclazide under the HPLC conditions described is not only ion-exchange mode but reversed-phase mode between the anion-exchange resin and the mobile phase. The detection limit of gliclazide was 0.2 μg/ml in plasma. The coefficient of variation for the within-day assay was 5.0% (0.2 μg/ml, n=8). The decay curve of serum gliclazide in diabetic patients was determined. 相似文献
923.
Summary Changes in an autophagic system during differentiation of cells ofDictyostelium discoideum, NC-4 were studied under light and electron microscopes, and it was demonstrated cytochemically that acid phosphatase was almost exclusively localized in food and autophagic vacuoles. Autophagic vacuoles first appeared during formation of loose aggregates, coupled with the defecation of food vacuoles. Autophagic vacuoles seem to originate from flat sacs which segregate parts of the cytoplasm. No acid phosphatase was detected in the vacuoles when first formed, but activity appeared later probably due to fusion with Golgi-like vesicles. When starved cells were not allowed to aggregate due to a low cell density, they formed no autophagic vacuoles but retained many food vacuoles. This indicates that the formation of autophagic vacuoles is not simply due to starvation, but to cell interaction mediated by cell contact. Autophagic vacuoles containing acid phosphatase rapidly increased in number in all cells in the early stage of aggregation. After papillae formed, however, they selectively decreased in the prespore cells, but developed further and grew larger in the prestalk cells. 相似文献
924.
925.
M Maeda K Okada K Wakabayashi K Honda K Ito Y Kinjo 《Journal of inorganic biochemistry》1991,42(1):37-45
The complex formation of thiomalic acid (H3L) with Hg(II) and Pb(II) was investigated under physiological conditions of 37 degrees C and 0.15 mol dm-3 NaCl by potentiometric titrations using glass electrodes. From the analysis of the emf data in the two systems by use of computer program MIQUV it was concluded that the species formed in the two systems are [HgH4L2], [HgH3L]-, [HgH2L2]2-, [HgHL2]3-, [HgHL], [HgL]-, [HgL2]4-, [Hg(OH)L]2-, [Hg(OH)L2]5-, [PbH2L2]2-, [PbH2L]+, [PbHL2]3-, [PbHL], [PbL]-, [Pb(OH)L]2-, and [Pb(OH)2L]3-. The hydrolytic reactions of Hg(II), data on which were used in the analysis of the above system, were also studied by separate potentiometric titrations. Measurements of 13C NMR spectra of [HgL2]4- and [PbL]- and [PbHL2]3- in D2O solutions suggested that the ligand coordinates with both the metal ions through the sulfhydryl group and one of the two carboxylate groups in such a way that the five-membered chelate ring is formed within the complexes. 相似文献
926.
927.
Molecular evolution of intergenic DNA in higher primates: pattern of DNA changes, molecular clock, and evolution of repetitive sequences 总被引:7,自引:1,他引:6
A 3.1-kb intergenic DNA fragment located between the psi beta-globin and
delta-globin genes in the beta-globin gene cluster was cloned from gorilla,
orangutan, rhesus monkey, and spider monkey, and the nucleotide sequence of
each fragment was determined. The phylogeny of these four sequences,
together with two previously published allelic sequences from humans and
one from chimpanzee, was constructed, and the accumulation of mutations in
the region was analyzed. The sites of base substitutions are not evenly
distributed within the region: two Alu repeats have accumulated 0.21 + 0.02
substitutions/site with 0.15 + 0.008 substitutions/site in the remainder of
the fragment. The occurrence of substitutions at neighboring sites is more
frequent than would be expected if they were independent. The observed
excesses disappear when ancestral -CG- dinucleotide sites are excluded. The
phylogenetic relationships of the sequences indicate that the human
sequence shares a most recent coancestor with the chimpanzee sequence. The
data also show that great apes have accumulated fewer mutations in this
part of the genome than has the rhesus monkey. The relative rates of
accumulation of 12 kinds of nucleotide substitution in the region during
primate evolution are asymmetric in the DNA strands. From these rates of
accumulation, the origin of a simple stretch of sequence near the 3' end of
the 3.1-kb fragment was deduced to be a sequence comprising 50% T and 50% C
on one strand. The two oppositely oriented Alu sequences in the 3.1-kb
region were inserted at their present positions before the divergence of
the New-World monkeys from other lineages. Our analysis shows that the
nucleotide sequences of the two Alu repeats in spider monkey are
unexpectedly similar both to each other and to the deduced ancestral
sequence of Alu repeats. The data suggest that there has been some type of
recombinational event between the spider monkey Alu repeats but that it was
not a simple gene conversion.
相似文献
928.
N Maeda T Kawasaki K Osawa Y Yamamoto H Sumida T Masuda M Kumegawa 《Acta anatomica》1987,128(4):326-333
Muscle fibers of the masseter muscle of mice which had been fed a fine-grained diet for various periods were studied histochemically and morphometrically. The diameters of both extrafusal and intrafusal muscle fibers decreased with time in mice fed a fine-grained diet, compared with those of control mice. In animals maintained on the special diet for 160 days after weaning at the 20th postnatal day, the effects of the diet on the diameter of muscle spindles were severe, and the diameter of each type of red and white fibers was significantly smaller than those of control animals. But a significant difference was not recognized in the diameter of intermediate fibers between control and treated mice. Unexpectedly, white fibers having a smaller diameter than red fibers were observed in diet-fed mice after the 180th postnatal day, although white fibers having such small diameter were not detectable in control animals. Succinic dehydrogenase activities were decreased in both extrafusal and intrafusal fibers of experimental animals. Moreover, muscle spindles with no annulospiral endings were increased in number in mice fed the diet for 130 and 160 days after weaning, although those spindles also increased in control animals. The diameters of outer capsules and primary endings were also significantly decreased in the animals kept on the diet for a long time. These effects of the fine-grained diet on the mouse masseter muscle became severer with time. 相似文献
929.
930.
Continuous internalization of tumor necrosis factor receptors in a human myosarcoma cell line 总被引:13,自引:0,他引:13
N Watanabe H Kuriyama H Sone H Neda N Yamauchi M Maeda Y Niitsu 《The Journal of biological chemistry》1988,263(21):10262-10266
The cell dynamics of the receptor for tumor necrosis factor (TNF) were examined in TNF-sensitive KYM cells derived from human myosarcoma. With receptor synthesis inhibited by cycloheximide, the half-life of the surface TNF receptor was 2 h in the absence of TNF and 30 min in its presence, suggesting that the TNF receptor is non-recycling and that its internalization is accelerated by TNF. During cell incubation with TNF receptor degradation suppressed by chloroquine, the number of surface TNF receptors remained approximately constant, but the total number of surface and internal TNF receptors increased gradually, at 3 h reaching 1.5 times the initial number, thus suggesting continuous synthesis, externalization, internalization, and degradation of the TNF receptor in the absence of cycloheximide. On cell incubation with 125I-TNF, the intracellular quantity of the pulse-labeled TNF-receptor complex promptly increased, reaching a maximum at 20 min, and then gradually declined, thus confirming that the TNF receptor is internalized as a TNF-receptor complex in the presence of TNF. During incubations with protein synthesis suppressed by cycloheximide following surface TNF receptor digestion by trypsin, TNF receptors reappeared on the cell surface, increasing in number to a peak at 60 min and gradually decreasing, and cells previously exposed to cycloheximide with or without TNF showed no recurrence of surface TNF receptors, suggesting that the TNF receptor is non-recycling. The results of the study thus suggest that the TNF receptor is continuously internalized and degraded intracellularly by lysosomes without being recycled regardless of the presence or absence of TNF and, further, that its internalization is accelerated when it is part of the TNF-receptor complex. 相似文献