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31.
Marina Cinco Elena Banfi Carmelo Stornello F. Campo H. Korver 《FEMS microbiology letters》1989,47(8-9):499-504
Abstract A strain of Leptospira interrogans was isolated from a patient suffering from leptospirosis and was typed by the Gross Agglutination Absorption test using monoclonal antibodies prepared against different serovars of the Australis serogroup. This newly isolated strain belonged to serovar bratislava . It is the first reported isolation from man, in Italy, of Leptospira bratislava , thus supporting the emerging role of this serovar in human leptospirosis. 相似文献
32.
Steven A. Narod Dilys M. Parry Jillian Parboosingh Gilbert M. Lenoir Martin Ruttledge Georges Fischer Roswell Eldridge Robert L. Martuza Marina Frontali Jonathan Haines James F. Gusella Guy A. Rouleau 《American journal of human genetics》1992,51(3):486-496
Neurofibromatosis type 2 (NF2) is an autosomal dominant syndrome characterized by the development of vestibular schwannomas and other tumors of the nervous system, including cranial and spinal meningiomas, schwannomas, and ependymomas. The presence of bilateral vestibular schwannomas is sufficient for the diagnosis. Skin manifestations are less common than in neurofibromatosis type 1 (NF1; von Recklinghausen disease). The apparent clinical distinction between NF1 and NF2 has been confirmed at the level of the gene locus by linkage studies; the gene for NF1 maps to chromosome 17, whereas the gene for NF2 has been assigned (in a single family) to chromosome 22. To increase the precision of the genetic mapping of NF2 and to determine whether additional susceptibility loci exist, we have performed linkage analysis on 12 families with NF2 by using four polymorphic markers from chromosome 22 and a marker at the NF1 locus on chromosome 17. Our results confirm the assignment of the gene for NF2 to chromosome 22 and do not support the hypothesis of genetic heterogeneity. We believe that chromosome 22 markers can now be used for presymptomatic diagnosis in selected families. The NF2 gene is tightly linked to the D22S32 locus (maximum lod score 4.12; recombination fraction 0). A CA-repeat polymorphism at the CRYB2 locus was the most informative marker in our families (lod score 5.99), but because the observed recombination fraction between NF2 and CRYB2 was 10 cM, predictions using this marker will need to be interpreted with caution. 相似文献
33.
Pranav K. Sinha E. K ttgen Marina St ffler-Meilicke Elisabetta Gianazza Pier Giorgio Righetti 《Journal of biochemical and biophysical methods》1990,20(4):345-352
Up to the present time it has been impossible to perform two-dimensional (2-D) separations in very acidic immobilized pH gradients (IPG), due to the lack of suitable buffering acrylamido derivatives to be incorporated into the polyacrylamide matrix. The advent of the pK 3.1 buffer (2-acrylamido glycolic acid; Righetti et al., J. Biochem. Biophys. Methods 16, 1988, 185–192) allowed the formulation of such acidic gradients. We report here separations in IPG pH 2.8–5.0 intervals of polypeptide chains from total lysates of rat intestinal and liver cells and 30S and 50S ribosomal proteins from Halobacterium marismortui. Conditions are given for highly reproducible first and second dimensions gels and for a proper silver staining of 2-D maps with practically no background deposition. 相似文献
34.
Claudia Gaspar Iscia Lopes-Cendes Anita L. DeStefano Patrícia Maciel Isabel Silveira Paula Coutinho Patrick MacLeod Jorge Sequeiros Lindsay A. Farrer G. A. Rouleau 《Human genetics》1996,98(5):620-624
Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar degeneration originally described in families of Portuguese-Azorean
ancestry. The hypothesis that its present world distribution could result from the spread of an original founder mutation
has been raised. To test this possibility we have conducted a linkage disequilibrium study of markers segregating with the
MJD1 locus in a total of 64 unrelated families of different geographical origins. Significant association was detected between
the MJD1 locus and marker alleles at loci D14S280, D14S1050 and D14S81. All affected individuals, except one Chinese family, had allele
3 (237 bp) at D14S280. This finding is consistent with a founder effect in our MJD population. However, distinct haplotypes
were observed in patients originating from the two Azorean islands showing the highest disease prevalence; therefore, the
possible existence of more than one founder mutation can not be excluded with the markers currently available.
Received: 27 February 1996 / Revised: 4 June 1996 相似文献
35.
Phosphorylation of the regulatory light chain is an important mechanism for the activation of myosin in non-muscle cells. Unlike most myosin light chain kinases (MLCKs), MLCK-A from Dictyostelium is not activated by Ca2+/calmodulin. Autophosphorylation increases activity, but only to a low level, suggesting that there is an additional activation mechanism. Here, we show that MLCK-A is autophosphorylated on Thr289, which is C-terminal to the catalytic domain. Phosphorylation of MLCK-A increases in response to concanavalin A (conA) treatment of cells, which was previously shown to activate MLCK-A. However, a mutant kinase with an alanine at position 289 (T289A) is also phosphorylated in vivo, indicating that there is an additional phosphorylated residue. Based on comparisons with other protein kinases, we tested whether phosphorylation of Thr166 drives activation of MLCK-A. Our data indicate that phosphorylation of Thr289 occurs in vivo, but is not associated with conA-induced activation, whereas phosphorylation of Thr166 by some as yet unidentified kinase is associated with activation. Replacement of Thrl66 with glutamate results in a 12-fold increase in activity as compared with the wild-type enzyme, supporting the idea that phosphorylation of Thr166 increases MLCK-A activity. 相似文献
36.
Abstract The digestive tract and its endocytotic activity in the catenulid Stenostomum grande were studied by electron microscopy. The pharynx was typical of the simplex type. At the mouth, between the integumental epithelium and the pharyngeal epithelium proper, was a transition zone. Among the epithelial cells of this transition were monociliated sensory cells and the necks of bucco-pharyngeal secretory cells of two types. The pharyngeal epithelium proper was densely ciliated, with long ciliary rootlets and mitochondria. It was surrounded by two layers of muscles. The gastrodermis consisted of phagocytes and typical secretory Minotian cells. It was underlain by a delicate basal lamina and muscle fibers. Distinctive of the phagocytes was the presence of differentiated cilia, cup-shaped mitochondria, and vacuoles with dense inclusions. Morphological differences between pharyngeal and gastrodermal cilia suggest functional differences. Experiments using latex beads as tracers and the identification of acid phosphatase in cytoplasmic vacuoles pointed to a high level of endocytotic and digestive activity in the phagocytes. Our data demonstrate that the basic structure of the digestive tract in S. grande conforms well to that of other free-living platyhelminths, but it does have ultrastructural peculiarities. 相似文献
37.
38.
Cells of Pseudomonas stutzeri in suspensions of TiO2 ranging in concentration from 0.5 to 4.0 g l-1 were irradiated with a blacklight blue u.v. source displaying peak emissivity at approximately 370 mm. Irradiation under these conditions is known to result in the generation of lethal free radicals. During irradiation the suspensions were agitated, using a specially modified laboratory shaker, to ensure efficient exposure of the TiO2 . A u.v. radiation dose of 175 kJ m-2 resulted in cell fractional survival ranging from 5.5 times 10-5 , at the lowest TiO2 concentration, to 1.0 times 10-6 , at the highest TiO2 concentration. The advantages of contactors employing TiO2 suspensions are briefly compared to immobilized TiO2 systems. 相似文献
39.
Marina I. Stanilova Valentina P. Ilcheva Nedjalka A. Zagorska 《Plant cell reports》1994,13(8):451-453
Summary The present work deals with the in vitro methods for rapid propagation, and morphogenetic potential of the rare and endangered bulb species Leucojum aestivum L., Amaryllidaceae, and Lilium rhodopaeum Delip., Liliaceae. The morphogenetic potential of different plant organs (bulb, stem, leaves and ovaries) was studied. Leaves of Leucojum aestivum L. and basal parts of the bulb in Lilium rhodopaeum Delip. possess the highest regeneration activity. Murashige and Skoog (MS) medium + 1 mg/l 6-benzylaminopurine (BAP) + 1 mg/l kinetin and Linsmaier and Skoog (LS) medium + 0.5 mg/l 1-naphthaleneacetic acid (NAA) + 0.1 mg/l kinetin were favourable for direct organogenisis from these explants. A stimulating effect of alow gamma-irradiation dose (5 Gy) upon the quantity and growth intensity of the bulbs formed by the explants in in vitro conditions is observed. 相似文献
40.
Mario Herrera-Marschitz C. Fabián Loidl Zhi-Bing You Kurt Andersson Rodolfo Silveira William T. O'Connor Michel Goiny 《Molecular neurobiology》1994,9(1-3):171-182
The neurocircuitries of the basal ganglia are studied with in vivo microdialysis, with special consideration to dopamine transmission and its interaction with other neurotransmitter systems. The aim is to develop experimental models to study the pathophysiology and therapy of neurodegenerative disorders of the basal ganglia, as well as to develop models to study the short- and long-term consequences of perinatal asphyctic lesions. A main goal of these studies is to find and to characterize new treatments for these disorders. 相似文献