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991.
992.
Kenneth Petren Ted J. Case 《Evolution; international journal of organic evolution》1997,51(1):206-219
The evolution of body size was reconstructed in chuckwallas (genus Sauromalus), large herbivorous lizards of southwest North America, using a phylogeny derived from sequence variation in the mitochondrial cytochrome b gene. The body mass of two endemic island species (S. hispidus and S. varius) is typically fivefold larger than mainland species. We tested the hypothesis that large body size has evolved on these islands in response to local ecological conditions against the alternative hypothesis that large size is simply retained from large iguanine ancestors. The most parsimonious tree topology depicts the insular gigantic Sauromalus as monophyletic, having diverged from a common ancestor on the Baja California peninsula after the radiation of smaller bodied clades. In a robustness analysis of this topology, we found general support for this tree over alternative topologies representing minimum evolution hypotheses that imply large body size is retained from large iguanine ancestors. The most parsimonious reconstruction of body size evolution implies a change from large to small size after the Sauromalus ancestor diverged from Iguana, and one reversal back to large size within Sauromalus. The large size increase in the gigantic clade contrasts with evolutionary stasis of small body size (for an iguanine) in mainland populations. The gigantic species show 3–4% total sequence divergence from S. obesus populations on the nearby Baja California peninsula, and mainland populations of S. obesus obesus show similar levels of divergence from each other. An analysis of character transitions and comparative behavior implicates predation, and its relaxation on isolated islands, as a strong selective force in Sauromalus. Patterns of genetic differentiation in Sauromalus and biogeographic implications are discussed. 相似文献
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996.
Ted J. Kaptchuk Jessica Shaw Catherine E. Kerr Lisa A. Conboy John M. Kelley Thomas J. Csordas Anthony J. Lembo Eric E. Jacobson 《Culture, medicine and psychiatry》2009,33(3):382-411
Patients in the placebo arms of randomized controlled trials (RCT) often experience positive changes from baseline. While
multiple theories concerning such “placebo effects” exist, peculiarly, none has been informed by actual interviews of patients
undergoing placebo treatment. Here, we report on a qualitative study (n = 27) embedded within a RCT (n = 262) in patients
with irritable bowel syndrome. Besides identical placebo acupuncture treatment in the RCT, the qualitative study patients
also received an additional set of interviews at the beginning, midpoint, and end of the trial. Interviews of the 12 qualitative
subjects who underwent and completed placebo treatment were transcribed. We found that patients (1) were persistently concerned
with whether they were receiving placebo or genuine treatment; (2) almost never endorsed “expectation” of improvement but
spoke of “hope” instead and frequently reported despair; (3) almost all reported improvement ranging from dramatic psychosocial
changes to unambiguous, progressive symptom improvement to tentative impressions of benefit; and (4) often worried whether
their improvement was due to normal fluctuations or placebo effects. The placebo treatment was a problematic perturbation
that provided an opportunity to reconstruct the experiences of the fluctuations of their illness and how it disrupted their
everyday life. Immersion in this RCT was a co-mingling of enactment, embodiment and interpretation involving ritual performance
and evocative symbols, shifts in bodily sensations, symptoms, mood, daily life behaviors, and social interactions, all accompanied
by self-scrutiny and re-appraisal. The placebo effect involved a spectrum of factors and any single theory of placebo—e.g.
expectancy, hope, conditioning, anxiety reduction, report bias, symbolic work, narrative and embodiment—provides an inadequate
model to explain its salubrious benefits.
T.K., E.J., L.C., C.K., J.K. and A.L. initiated the RCT and obtained funding. E.J., T.K., C.K. and L.C. designed the qualitative
study. Interviews were performed by E.J., and L.C., T.K., J.S., E.J., L.C., C.K., T.C., A.L. and J.K. performed the initial
analysis and interpretation. J.S. devised the coding framework in consultation with all authors. T.K., E.J. and J.S. wrote
the first draft. All authors commented on subsequent drafts. T.K. is the guarantor and accepts full responsibility for the
conduct of the study and the contents of the paper. 相似文献
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A 26-item questionnaire was distributed to 153 American zoos, aquariums, and animal parks. A response rate of 78% was achieved after a second mailing. The results indicate that most zoos encourage research and have engaged in recent research activities of some type. Behavioral and reproductive research are the most common types of scientific activity, while nonprimate mammals are the most likely research subjects. Research activity is correlated with attendance and with academic affiliations. Nearly half of the institutions surveyed reported that their research efforts were expanding. 相似文献
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999.
Ted W. Johnson Klaus R. Dress Martin Edwards 《Bioorganic & medicinal chemistry letters》2009,19(19):5560-5564
The Golden Triangle is a visualization tool developed from in vitro permeability, in vitro clearance and computational data designed to aid medicinal chemists in achieving metabolically stable, permeable and potent drug candidates. Classifying compounds as permeable and stable and plotting molecular weight (MW) versus octanol:buffer (pH 7.4) distribution coefficients (log D) or estimated octanol:buffer (pH 7.4) distribution coefficients (elog D) reveals useful trends. Analysis of at least two orthogonal trends, such as permeability and clearance, can be extremely effective in balancing and optimizing multiple properties. In addition, molecular weight and log D impact potency-efficiency calculations, allowing potency, clearance and permeability to be optimized simultaneously. 相似文献