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91.
Identifying the structure in cuttlefish visual signals 总被引:1,自引:0,他引:1
Crook AC Baddeley R Osorio D 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2002,357(1427):1617-1624
The common cuttlefish (Sepia officinalis) communicates and camouflages itself by changing its skin colour and texture. Hanlon and Messenger (1988 Phil. Trans. R. Soc. Lond. B 320, 437-487) classified these visual displays, recognizing 13 distinct body patterns. Although this conclusion is based on extensive observations, a quantitative method for analysing complex patterning has obvious advantages. We formally define a body pattern in terms of the probabilities that various skin features are expressed, and use Bayesian statistical methods to estimate the number of distinct body patterns and their visual characteristics. For the dataset of cuttlefish coloration patterns recorded in our laboratory, this statistical method identifies 12-14 different patterns, a number consistent with the 13 found by Hanlon and Messenger. If used for signalling these would give a channel capacity of 3.4 bits per pattern. Bayesian generative models might be useful for objectively describing the structure in other complex biological signalling systems. 相似文献
92.
A questionnaire about working with dreams was given to 95 clients in ongoing psychotherapy. Results indicated that clients who discussed dreams in therapy (68%) had more positive attitudes toward dreams, higher dream recall, and more therapist encouragement for talking about dreams than clients who did not. Clients reported that therapists used more exploratory than insight or action dream-related activities. The outcome of the dream session was positively related to the therapists' encouragement of dream work and dream-related activities used. Clients who had not discussed dreams in therapy indicated that they had not because there was not enough time in sessions to work on dreams or it had never occurred to them to talk about their dreams in therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
93.
Gillian M. Morrison Donald J. Davidson Fiona M. Kilanowski Duncan W. Borthwick Ken Crook Alison I. Maxwell John R.W. Govan Julia R. Dorin 《Mammalian genome》1998,9(6):453-457
Defensin are 3–4 kDa antimicrobial peptides of which three distinct families have been identified; α-defensin, β-defensins,
and insect defensins. Recent investigations have shown that β-defensins are present in the human airways and may be relevant
to the pathogenesis of cystic fibrosis (CF) lung disease. We report here the further characterization of a recently identified
mouse β-defensin gene, Defb1, sometimes referred to as mBD-1, which is homologous to the human airway beta defensin hBD-1. We report that Defb1 is expressed in a variety of tissues including the airways and, similar to hBD-1, is not upregulated by lipopolysaccharide (LPS). Defb1 was found to consist of two small exons separated by a 16-kb intron and cytogenetic, and physical mapping linked it to the
alpha defensin gene cluster on mouse Chromosome (Chr) 8. Functional studies demonstrate that, like hBD-1, Defb1 demonstrates
a salt-sensitive antimicrobial activity against Pseudomonas aeruginosa. Of relevance to CF lung disease is the fact that neither the hBD-1 nor the mBD-1 peptides are active against Burkholderia cepacia.
Received: 3 December 1997 / Accepted: 17 February 1998 相似文献
94.
A parsimony analysis was performed on restriction sites at the Hba-ps4
pseudogene locus within one of four inversions associated with mouse t
haplotypes. The results suggest that all t haplotypes form a monophyletic
group and that the in (17)4 inversion originated before the radiation of
the Mus musculus species complex but after the divergence of the lineages
leading to M. spretus, M. abbotti, and M. hortulanus. A time frame based on
the evolutionary rate of mouse pseudogenes places the origin of this t
haplotype inversion at 1.5 Mya, or approximately 1.5 Myr after the origin
of the more proximal t complex inversion, in (17)2. The accumulated
evidence indicates that complete t haplotypes have been assembled in a
stepwise manner, with each of these inversions occurring on separate
chromosomal lineages and at different evolutionary times. In addition, the
evolutionary relationships of pseudogene sequences resulting from genetic
exchange between wild-type and t haplotype alleles were examined. Analysis
of sequences from the 5' and 3' sides of a putative site of recombination
resulted in cladograms with different topologies. The implications for
hypotheses concerning the evolutionary forces acting on t haplotypes and
their rapid propagation throughout worldwide populations of mice are
discussed.
相似文献
95.
In certain lines of hepatoma tissue culture (HTC) cells, glutamine synthetase (EC 6.3.1.2) specific activity is increased 2.5- to 3-fold by the addition of glucocorticoids to the growth media. Actinomycin D blocks both the induction and deinduction of glutamine synthetase by glucocorticoids, suggesting a requirement of RNA synthesis for both processes. Using an antiserum raised against purified rat liver glutamine synthetase, we have precipitated radiolabeled glutamine synthetase from HTC cells. Electrophoresis of the immunoprecipitates on sodium didecyl sulfate-acrylamide gels isolates the subunit of glutamine synthetase and permits the radioactivity in the glutamine synthetase band to be quantitated. Using this technique, we have investigated the effect of dexamethasone, a synthetic glucocorticoid, on the rates of synthesis and degradation of glutamine synthetase. Dexamethasone (10(-7) M) increases the rate of synthesis of glutamine synthetase 2- to 3-fold but has no effect on the rate of glutamine synthetase degradation. The rates of total cell protein synthesis and degradation are not significantly affected by dexamethasone. The presence of actinomycin D at the time of removal of dexamethasone from induced cells prevents the fall in the induced rate of synthesis of glutamine synthetase normally seen when the inhibitor is removed from the culture medium. The regulation of glutamine synthetase by dexamethasone has been compared to the regulation of another dexamethasone-inducible enzyme in HTC cells, tyrosine aminotransferase, and been found to be similar in all parameters studied. 相似文献
96.
97.
98.
Artemis: sequence visualization and annotation 总被引:31,自引:0,他引:31
Rutherford K Parkhill J Crook J Horsnell T Rice P Rajandream MA Barrell B 《Bioinformatics (Oxford, England)》2000,16(10):944-945
SUMMARY: Artemis is a DNA sequence visualization and annotation tool that allows the results of any analysis or sets of analyses to be viewed in the context of the sequence and its six-frame translation. Artemis is especially useful in analysing the compact genomes of bacteria, archaea and lower eukaryotes, and will cope with sequences of any size from small genes to whole genomes. It is implemented in Java, and can be run on any suitable platform. Sequences and annotation can be read and written directly in EMBL, GenBank and GFF format. AVAILABITLTY: Artemis is available under the GNU General Public License from http://www.sanger.ac.uk/Software/Artemis 相似文献
99.
Karyotype of human ES cells during extended culture 总被引:12,自引:0,他引:12
100.
The anterior cingulate cortex (ACC) plays an important role in higher brain functions including learning, memory, and persistent pain. Long-term potentiation of excitatory synaptic transmission has been observed in the ACC after digit amputation, which might contribute to plastic changes associated with the phantom pain. Here we report a long-lasting membrane potential depolarization in ACC neurons of adult rats after digit amputation in vivo. Shortly after digit amputation of the hind paw, the membrane potential of intracellularly recorded ACC neurons quickly depolarized from ~-70 mV to ~-15 mV and then slowly repolarized. The duration of this amputation-induced depolarization was about 40 min. Intracellular staining revealed that these neurons were pyramidal neurons in the ACC. The depolarization is activity-dependent, since peripheral application of lidocaine significantly reduced it. Furthermore, the depolarization was significantly reduced by a NMDA receptor antagonist MK-801. Our results provide direct in vivo electrophysiological evidence that ACC pyramidal cells undergo rapid and prolonged depolarization after digit amputation, and the amputation-induced depolarization in ACC neurons might be associated with the synaptic mechanisms for phantom pain. 相似文献