全文获取类型
收费全文 | 282篇 |
免费 | 16篇 |
出版年
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 6篇 |
2016年 | 13篇 |
2015年 | 19篇 |
2014年 | 19篇 |
2013年 | 14篇 |
2012年 | 35篇 |
2011年 | 22篇 |
2010年 | 11篇 |
2009年 | 5篇 |
2008年 | 13篇 |
2007年 | 5篇 |
2006年 | 12篇 |
2005年 | 3篇 |
2004年 | 10篇 |
2003年 | 23篇 |
2002年 | 10篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有298条查询结果,搜索用时 46 毫秒
61.
Reduced expression of chemerin in visceral adipose tissue associates with hepatic steatosis in patients with obesity
下载免费PDF全文
![点击此处可从《Obesity (Silver Spring, Md.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
62.
Ronald E. Bontrop Marcel G. J. Tilanus Marlies M. A. Mikulski Dienne G. Elferink Annemarie Termijtelen Rene R. P. de Vries Jon J. van Rood Marius J. Giphart 《Immunogenetics》1988,27(1):40-45
HLA-DR molecules were isolated from HLA-DR3, –5, and –w6 positive homozygous B-cell lines by immunoprecipitation with monoclonal antibodies and analyzed by gel electrophoretic techniques. DNA isolated from the same cell lines was digested with the restriction enzyme Taq I and hybridized with a DR beta full-length cDNA probe. We demonstrated that certain DR
I alleles are found in combination with different DR
III alleles as defined by Southern blotting, protein chemistry, a functional assay using purified protein derivative-specific T-cell lines, and, in one case, also alloreactive T-cell reagents. Our results indicate that within the family of HLA-DRw52-associated haplotypes DR beta chain genes may have been transferred from one haplotype to another. The implications of these findings are discussed. 相似文献
63.
Summary The opisthonephric kidney of the rainbow trout was investigated by light- and electron microscopy and a fluorescent-histochemical technique for biogenic amines was used. Preglomerular sphincters at the origin of afferent arterioles are present in this euryhaline teleost. The branching point of the afferent arteriole is characterized by (i) the formation of a right angle with the parent vessel, (ii) circularly arranged smooth muscle cells of the tunica media, (iii) additional circularly arranged smooth muscle cells intercalated between endothelium and tunica media, and (iv) a collar-like arrangement of several large endothelial cells with elaborate marginal folds and abundant myoendothelial junctions. A dense adrenergic innervation displaying specific fluorescence was found along the terminal arterioles and afferent arterioles, and conspicuously at the preglomerular sphincters. These results are suggestive of a neural participation in kidney function. They are discussed on the basis of recent evidence from pharmacological and physiological experiments for neural involvement in glomerular intermittency. 相似文献
64.
Pollination Biology of Piperaceae Species in Southeastern Brazil 总被引:3,自引:2,他引:1
Phenology, floral biology and breeding system are describedfor 14 Piperaceae species at two sites covered by semi-deciduousforest in southeastern Brazil. Flowering occurred continuouslythroughout the year, with a peak during the windy months. Allspecies had minute odorous and nectarless flowers visited byinsects; five of them showed a substantial degree of self-compatibility,and one was andromonoecious. Seven species were wind pollinated,and three were exclusively pollinated by insects. Flower visitorswere mainly hoverflies and bees. Copyright 2000 Annals of BotanyCompany Piper spp., Ottonia spp., Pothomorphe umbellata, pepper family, phenology, floral biology, breeding system, ambophily, semi-deciduous forest 相似文献
65.
This paper discusses archaeobotanical remains from the settlement mound of Kursakata, Nigeria, comprising both charred and uncharred seeds and fruits as well as charcoal. In addition, impressions of plant tempering material in potsherds were analysed. The late Stone Age and Iron Age sequence at Kursakata is date from 1000 cal. B.C. to cal. A.D. 100. DomesticatedPennisetum (pearl millet), wild Paniceae and wild rice are the most common taxa. Kernels from tree fruits were regularly found including large numbers ofVitex simplicifolia—a tree which is absent from the area today. A distinct change in plant spectra can be observed between the late Stone Age and the Iron Age. Although domesticated pearl millet was already known at the beginning of the settlement sequence of Kursakata, it only gained greater economic importance during the Iron Age. Besides farming, pastoralism and fishing, gathering of wild plants always played a major role in the subsistence strategy of the inhabitants of Kursakata. The charcoal results show that firewood was mainly collected from woodlands on the clay plains, which must have been more diverse than today. The end of the late Stone Age in the Chad Basin was presumably accompanied by the onset of drier environmental conditions from ca. 800 cal. B.C. onwards. 相似文献
66.
67.
68.
69.
Vandael DH Marcantoni A Mahapatra S Caro A Ruth P Zuccotti A Knipper M Carbone E 《Molecular neurobiology》2010,42(3):185-198
L-type Ca2+ channels (LTCCs, Cav1) open readily during membrane depolarization and allow Ca2+ to enter the cell. In this way, LTCCs regulate cell excitability and trigger a variety of Ca2+-dependent physiological processes such as: excitation–contraction coupling in muscle cells, gene expression, synaptic plasticity,
neuronal differentiation, hormone secretion, and pacemaker activity in heart, neurons, and endocrine cells. Among the two
major isoforms of LTCCs expressed in excitable tissues (Cav1.2 and Cav1.3), Cav1.3 appears suitable for supporting a pacemaker current in spontaneously firing cells. It has steep voltage dependence and
low threshold of activation and inactivates slowly. Using Cav1.3−/− KO mice and membrane current recording techniques such as the dynamic and the action potential clamp, it has been possible
to resolve the time course of Cav1.3 pacemaker currents that regulate the spontaneous firing of dopaminergic neurons and adrenal chromaffin cells. In several
cell types, Cav1.3 is selectively coupled to BK channels within membrane nanodomains and controls both the firing frequency and the action
potential repolarization phase. Here we review the most critical aspects of Cav1.3 channel gating and its coupling to large conductance BK channels recently discovered in spontaneously firing neurons and
neuroendocrine cells with the aim of furnishing a converging view of the role that these two channel types play in the regulation
of cell excitability. 相似文献
70.
Ashley Farlow Eshwar Meduri Marlies Dolezal Liushuai Hua Christian Schl?tterer 《PLoS genetics》2010,6(1)
Intron number varies considerably among genomes, but despite their fundamental importance, the mutational mechanisms and evolutionary processes underlying the expansion of intron number remain unknown. Here we show that Drosophila, in contrast to most eukaryotic lineages, is still undergoing a dramatic rate of intron gain. These novel introns carry significantly weaker splice sites that may impede their identification by the spliceosome. Novel introns are more likely to encode a premature termination codon (PTC), indicating that nonsense-mediated decay (NMD) functions as a backup for weak splicing of new introns. Our data suggest that new introns originate when genomic insertions with weak splice sites are hidden from selection by NMD. This mechanism reduces the sequence requirement imposed on novel introns and implies that the capacity of the spliceosome to recognize weak splice sites was a prerequisite for intron gain during eukaryotic evolution. 相似文献