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151.
Stevens JA Ivison RJ Dunlop JS Smail IR Percival WJ Hughes DH Röttgering HJ Van Breugel WJ Reuland M 《Nature》2003,425(6955):264-267
The most massive galaxies in the present-day Universe are found to lie in the centres of rich clusters. They have old, coeval stellar populations suggesting that the bulk of their stars must have formed at early epochs in spectacular starbursts, which should be luminous phenomena when observed at submillimetre wavelengths. The most popular model of galaxy formation predicts that these galaxies form in proto-clusters at high-density peaks in the early Universe. Such peaks are indicated by massive high-redshift radio galaxies. Here we report deep submillimetre mapping of seven high-redshift radio galaxies and their environments. These data confirm not only the presence of spatially extended regions of massive star-formation activity in the radio galaxies themselves, but also in companion objects previously undetected at any wavelength. The prevalence, orientation, and inferred masses of these submillimetre companion galaxies suggest that we are witnessing the synchronous formation of the most luminous elliptical galaxies found today at the centres of rich clusters of galaxies. 相似文献
152.
Cloning and expression of human and rat D1 dopamine receptors 总被引:25,自引:0,他引:25
Q Y Zhou D K Grandy L Thambi J A Kushner H H Van Tol R Cone D Pribnow J Salon J R Bunzow O Civelli 《Nature》1990,347(6288):76-80
The importance of the dopaminergic system in brain function has been emphasized by its association with neurological and psychiatric disorders such as Parkinson's disease and schizophrenia. On the basis of their biochemical and pharmacological characteristics, dopamine receptors are classified into D1 and D2 subtypes. As the most abundant dopamine receptor in the central nervous system, D1 receptors seem to mediate some behavioural responses, modulate activity of D2 dopamine receptors, and regulate neuron growth and differentiation. The D dopamine receptor has been cloned by low-stringency screening. We report here the cloning of human and rat D1 dopamine receptors by applying an approach based on the polymerase chain reaction. The cloned human D1 dopamine receptor has been characterized on the basis of four criteria: the deduced amino-acid sequence, which reveals that it is a G protein-coupled receptor; the tissue distribution of its messenger RNA, which is compatible with that of the D1 dopamine receptor; its pharmacological profile when transfected into COS-7 cells; and its ability to stimulate the accumulation of cyclic AMP in human 293 cells. 相似文献
153.
154.
G. F. Van Went 《Cellular and molecular life sciences : CMLS》1978,34(3):324-325
Summary Using the micronucleus test as a screening method for mutagenic activity, no significant increase in the number of micronuclei was found when LSD, psilocybin or 9-THC were administered in 3 logarithmically increasing doses to mice. Azathioprine (Imuran®), given as a positive control, caused a statistically significant increase in micronucleated cells.Acknowledgment. The expert technical assistance of Mr Joop Branger is greatfully acknowledged. We thank Prof. Dr C. A. Salemink, University of Utrecht, for the supply of the THC, and Dr J. Fokkens, National Institute of Public Health, for preparing the solutions. 相似文献
155.
E. L. Van Alstyne Celia D. Sladek D. C. Smith 《Cellular and molecular life sciences : CMLS》1977,33(7):863-864
Summary The plasma concentration of L-carnitine in scalded rats was determined to be greater (p0.05) than that of control rats at 6 h following the administration of a 20% body surface, full-thickness burn produced by scalding in a 100°C water bath for 15 sec. 相似文献
156.
H. J. Wynne K. H. Van Buuren W. Wakelkamp 《Cellular and molecular life sciences : CMLS》1982,38(6):655-657
Summary Capacity factors in reversed-phase HPLC and distribution constants in octan-l-ol/water of N-acetyl-N-methylamino acid amides have been measured as a function of temperature. The HPLC capacity factors are proposed as estimates of the hydrophobicity of the amino acid side chains.We acknowledge the interest in this work of Dr H. van Rooy, Dr J. Kinkel, Prof. W. Soudijn and Prof. E. Tomlinson. 相似文献
157.
Mutations in GRIN2A and GRIN2B encoding regulatory subunits of NMDA receptors cause variable neurodevelopmental phenotypes 总被引:1,自引:0,他引:1
Endele S Rosenberger G Geider K Popp B Tamer C Stefanova I Milh M Kortüm F Fritsch A Pientka FK Hellenbroich Y Kalscheuer VM Kohlhase J Moog U Rappold G Rauch A Ropers HH von Spiczak S Tönnies H Villeneuve N Villard L Zabel B Zenker M Laube B Reis A Wieczorek D Van Maldergem L Kutsche K 《Nature genetics》2010,42(11):1021-1026
N-methyl-D-aspartate (NMDA) receptors mediate excitatory neurotransmission in the mammalian brain. Two glycine-binding NR1 subunits and two glutamate-binding NR2 subunits each form highly Ca2(+)-permeable cation channels which are blocked by extracellular Mg2(+) in a voltage-dependent manner. Either GRIN2B or GRIN2A, encoding the NMDA receptor subunits NR2B and NR2A, was found to be disrupted by chromosome translocation breakpoints in individuals with mental retardation and/or epilepsy. Sequencing of GRIN2B in 468 individuals with mental retardation revealed four de novo mutations: a frameshift, a missense and two splice-site mutations. In another cohort of 127 individuals with idiopathic epilepsy and/or mental retardation, we discovered a GRIN2A nonsense mutation in a three-generation family. In a girl with early-onset epileptic encephalopathy, we identified the de novo GRIN2A mutation c.1845C>A predicting the amino acid substitution p.N615K. Analysis of NR1-NR2A(N615K) (NR2A subunit with the p.N615K alteration) receptor currents revealed a loss of the Mg2(+) block and a decrease in Ca2(+) permeability. Our findings suggest that disturbances in the neuronal electrophysiological balance during development result in variable neurological phenotypes depending on which NR2 subunit of NMDA receptors is affected. 相似文献
158.
Anske Van den Abbeele Sarah De Clercq Ariane De Ganck Veerle De Corte Berlinda Van Loo Sameh Hamdy Soror Vasundara Srinivasan Jan Steyaert Joël Vandekerckhove Jan Gettemans 《Cellular and molecular life sciences : CMLS》2010,67(9):1519-1535
RNA interference has tremendously advanced our understanding of gene function but recent reports have exposed undesirable
side-effects. Recombinant Camelid single-domain antibodies (VHHs) provide an attractive means for studying protein function without affecting gene expression.
We raised VHHs against gelsolin (GsnVHHs), a multifunctional actin-binding protein that controls cellular actin organization
and migration. GsnVHH-induced delocalization of gelsolin to mitochondria or the nucleus in mammalian cells reveals distinct
subpopulations including free gelsolin and actin-bound gelsolin complexes. GsnVHH 13 specifically recognizes Ca2+-activated gelsolin (K
d ~10 nM) while GsnVHH 11 binds gelsolin irrespective of Ca2+ (K
d ~5 nM) but completely blocks its interaction with G-actin. Both GsnVHHs trace gelsolin in membrane ruffles of EGF-stimulated
MCF-7 cells and delay cell migration without affecting F-actin severing/capping or actin nucleation activities by gelsolin.
We conclude that VHHs represent a potent way of blocking structural proteins and that actin nucleation by gelsolin is more
complex than previously anticipated. 相似文献
159.
Pieter Rondou Guy Haegeman Kathleen Van Craenenbroeck 《Cellular and molecular life sciences : CMLS》2010,67(12):1971-1986
Dopamine is an important neurotransmitter that regulates several key functions in the brain, such as motor output, motivation
and reward, learning and memory, and endocrine regulation. Dopamine does not mediate fast synaptic transmission, but rather
modulates it by triggering slow-acting effects through the activation of dopamine receptors, which belong to the G-protein-coupled
receptor superfamily. Besides activating different effectors through G-protein coupling, dopamine receptors also signal through
interaction with a variety of proteins, collectively termed dopamine receptor-interacting proteins. We focus on the dopamine
D4 receptor, which contains an important polymorphism in its third intracellular loop. This polymorphism has been the subject
of numerous studies investigating links with several brain disorders, such as attention-deficit hyperactivity disorder and
schizophrenia. We provide an overview of the structure, signalling properties and regulation of dopamine D4 receptors, and
briefly discuss their physiological and pathophysiological role in the brain. 相似文献
160.
Disrupted function and axonal distribution of mutant tyrosyl-tRNA synthetase in dominant intermediate Charcot-Marie-Tooth neuropathy 总被引:6,自引:0,他引:6
Jordanova A Irobi J Thomas FP Van Dijck P Meerschaert K Dewil M Dierick I Jacobs A De Vriendt E Guergueltcheva V Rao CV Tournev I Gondim FA D'Hooghe M Van Gerwen V Callaerts P Van Den Bosch L Timmermans JP Robberecht W Gettemans J Thevelein JM De Jonghe P Kremensky I Timmerman V 《Nature genetics》2006,38(2):197-202
Charcot-Marie-Tooth (CMT) neuropathies are common disorders of the peripheral nervous system caused by demyelination or axonal degeneration, or a combination of both features. We previously assigned the locus for autosomal dominant intermediate CMT neuropathy type C (DI-CMTC) to chromosome 1p34-p35. Here we identify two heterozygous missense mutations (G41R and E196K) and one de novo deletion (153-156delVKQV) in tyrosyl-tRNA synthetase (YARS) in three unrelated families affected with DI-CMTC. Biochemical experiments and genetic complementation in yeast show partial loss of aminoacylation activity of the mutant proteins, and mutations in YARS, or in its yeast ortholog TYS1, reduce yeast growth. YARS localizes to axonal termini in differentiating primary motor neuron and neuroblastoma cultures. This specific distribution is significantly reduced in cells expressing mutant YARS proteins. YARS is the second aminoacyl-tRNA synthetase found to be involved in CMT, thereby linking protein-synthesizing complexes with neurodegeneration. 相似文献