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71.
Nick Fenby Hong Pu Roger Pennell Uta Praekelt Rob Day Rod Scott 《Sexual plant reproduction》2010,23(4):255-264
Simple de novo screens in Arabidopsis thaliana have previously identified mutants that affect endosperm development but viable-embryo mutants have not been identified.
Our strategy to identify autonomous embryo development was to uncouple embryo and endosperm fertilisation. This involved a
male-sterile mutant population being crossed with a distinct pollen parent—the pollen was needed to initiate endosperm development
and because it was distinct, the maternal progeny could be selected from the hybrid population. This process was refined over
three stages, resulting in a viable approach to screen for autonomous embryo mutants. From 8,000 screened plants, a mutation
was isolated in which the integument cells extended from the ovule and proliferated into a second complete twinned ovule.
Some embryos from the mutant were normal but others developed fused cotyledons. In addition, a proportion of the progeny lacked
paternal genes. 相似文献
72.
The diploid species Brassica rapa(genome AA)and B.oleracea(genome CC)were compared by fuU-seale proteome analyses of seedling.A total of 28.2% of the proteins was common to both species,indicating the existence of a basal or ubiquitous proteome.How-ever,a number of discriminating proteins(32.0%)and specific proteins(39.8%)of the Brassica A and C genomes,respectively,were identified,which could represent potentially species-specific functions.Based on these A or C genome-specific proteins,a number of PCR-based markers to distinguish B.rapa and B.oleracea species were also developed. 相似文献
73.
Willem Kuyken Sarah Byford Richard Byng Tim Dalgleish Glyn Lewis Rod Taylor Edward R Watkins Rachel Hayes Paul Lanham David Kessler Nicola Morant Alison Evans 《Trials》2010,11(1):1-10
Background
The total effect of a medication is the sum of its drug effect, placebo effect (meaning response), and their possible interaction. Current interpretation of clinical trials' results assumes no interaction. Demonstrating such an interaction has been difficult due to lack of an appropriate study design.Methods
180 adults were randomized to caffeine (300 mg) or placebo groups. Each group received the assigned intervention described by the investigators as caffeine or placebo, in a randomized crossover design. 4-hour-area-under-the-curve of energy, sleepiness, nausea (on 100 mm visual analog scales), and systolic blood pressure levels as well as caffeine pharmacokinetics (in 22 volunteers nested in the caffeine group) were determined. Caffeine drug, placebo, placebo-plus-interaction, and total effects were estimated by comparing outcomes after, receiving caffeine described as placebo to receiving placebo described as placebo, receiving placebo described as caffeine or placebo, receiving caffeine described as caffeine or placebo, and receiving caffeine described as caffeine to receiving placebo described as placebo, respectively.Results
The placebo effect on area-under-the-curve of energy (mean difference) and sleepiness (geometric mean ratio) was larger than placebo-plus-interaction effect (16.6 [95% CI, 4.1 to 29.0] vs. 8.4 [-4.2 to 21.0] mm*hr and 0.58 [0.39 to 0.86] vs. 0.69 [0.49 to 0.97], respectively), similar in size to drug effect (20.8 [3.8 to 37.8] mm*hr and 0.49 [0.30 to 0.91], respectively), and its combination with the later was larger than total caffeine effect (29.5 [11.9 to 47.1] mm*hr and 0.37 [0.22 to 0.64]). Placebo-plus-interaction effect increased caffeine terminal half-life by 0.40 [0.12 to 0.68] hr (P = 0.007).Conclusions
Drug and placebo effects of a medication may be less than additive, which influences the interpretation of clinical trials. The placebo effect may increase active drug terminal half-life, a novel mechanism of placebo action.Trial Registration
ClinicalTrials.gov identification number - NCT00426010. 相似文献74.
75.
76.
Mongrain R Faik I Leask RL Rodés-Cabau J Larose E Bertrand OF 《Journal of biomechanical engineering》2007,129(5):733-742
In the context of drug eluting stent, we present two-dimensional numerical models of mass transport of the drug in the wall and in the lumen to study the effect of the drug diffusion coefficients in the three principal media (blood, vascular wall, and polymer coating treated as a three-compartment problem) and the impact of different strut apposition configurations (fully embedded, half embedded, and not embedded). The different conditions were analyzed in terms of their consequence on the drug concentration distribution in the arterial wall. We apply the concept of the therapeutic window to the targeted vascular wall region and derive simple metrics to assess the efficiency of the various stent configurations. Although most of the drug is dispersed in the lumen, variations in the blood flow rate within the physiological range of coronary blood flow and the diffusivity of the drug molecule in the blood were shown to have a negligible effect on the amount of drug in the wall. Our results reveal that the amount of drug cumulated in the wall depends essentially on the relative values of the diffusion coefficients in the polymer coating and in the wall. Concerning the strut apposition, it is shown that the fully embedded strut configuration would provide a better concentration distribution. 相似文献
77.
Scott RJ 《The New phytologist》2007,173(2):227-230
78.
Rohrich RJ 《Plastic and reconstructive surgery》2007,119(6):1941-1942
79.
Rohrich RJ 《Plastic and reconstructive surgery》2007,120(5):1425-1427
80.