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951.
952.
Background
Understanding social interactions requires the ability to accurately interpret conspecifics'' actions, sometimes only on the basis of subtle body language analysis. Here we address an important issue that has not yet received much attention in social neuroscience, that of an interaction between two agents. We attempted to isolate brain responses to two individuals interacting compared to two individuals acting independently.Methodology/Principal Findings
We used minimalistic point-light displays to depict the characters, as they provide the most straightforward way to isolate mechanisms used to extract information from motion per se without any interference with other visual information. Functional magnetic resonance imaging (fMRI) method was used to determine which brain regions were recruited during the observation of two interacting agents, mimicking everyday social scenes. While the mirror and mentalizing networks are rarely concurrently active, we found that both of them might be needed to catch the social intentions carried by whole-body motion.Conclusions/Significance
These findings shed light on how motor cognition contributes to social cognition when social information is embedded in whole-body motion only. Finally, the approach described here provides a valuable and original tool for investigating the brain networks responsible for social understanding, in particular in psychiatric disorders. 相似文献953.
Bernaudat F Frelet-Barrand A Pochon N Dementin S Hivin P Boutigny S Rioux JB Salvi D Seigneurin-Berny D Richaud P Joyard J Pignol D Sabaty M Desnos T Pebay-Peyroula E Darrouzet E Vernet T Rolland N 《PloS one》2011,6(12):e29191
Background
Membrane proteins are the targets of 50% of drugs, although they only represent 1% of total cellular proteins. The first major bottleneck on the route to their functional and structural characterisation is their overexpression; and simply choosing the right system can involve many months of trial and error. This work is intended as a guide to where to start when faced with heterologous expression of a membrane protein.Methodology/Principal Findings
The expression of 20 membrane proteins, both peripheral and integral, in three prokaryotic (E. coli, L. lactis, R. sphaeroides) and three eukaryotic (A. thaliana, N. benthamiana, Sf9 insect cells) hosts was tested. The proteins tested were of various origins (bacteria, plants and mammals), functions (transporters, receptors, enzymes) and topologies (between 0 and 13 transmembrane segments). The Gateway system was used to clone all 20 genes into appropriate vectors for the hosts to be tested. Culture conditions were optimised for each host, and specific strategies were tested, such as the use of Mistic fusions in E. coli. 17 of the 20 proteins were produced at adequate yields for functional and, in some cases, structural studies. We have formulated general recommendations to assist with choosing an appropriate system based on our observations of protein behaviour in the different hosts.Conclusions/Significance
Most of the methods presented here can be quite easily implemented in other laboratories. The results highlight certain factors that should be considered when selecting an expression host. The decision aide provided should help both newcomers and old-hands to select the best system for their favourite membrane protein. 相似文献954.
955.
Nicolas Coudray Gilles Hermann Daniel Caujolle-Bert Argyro Karathanou Françoise Erne-Brand Jean-Luc Buessler Pamela Daum Juergen M. Plitzko Mohamed Chami Urs Mueller Hubert Kihl Jean-Philippe Urban Andreas Engel Hervé-W. Rémigy 《Journal of structural biology》2011,173(2):365-374
We have built and extensively tested a tool-chain to prepare and screen two-dimensional crystals of membrane proteins by transmission electron microscopy (TEM) at room temperature. This automated process is an extension of a new procedure described recently that allows membrane protein 2D crystallization in parallel (Iacovache et al., 2010). The system includes a gantry robot that transfers and prepares the crystalline solutions on grids suitable for TEM analysis and an entirely automated microscope that can analyze 96 grids at once without human interference. The operation of the system at the user level is solely controlled within the MATLAB environment: the commands to perform sample handling (loading/unloading in the microscope), microscope steering (magnification, focus, image acquisition, etc.) as well as automatic crystal detection have been implemented. Different types of thin samples can efficiently be screened provided that the particular detection algorithm is adapted to the specific task. Hence, operating time can be shared between multiple users. This is a major step towards the integration of transmission electron microscopy into a high throughput work-flow. 相似文献
956.
Clemence Hatt Fran?ois Mankessi Jean-Baptiste Durand Frédéric Boudon Fabienne Montes Marc Lartaud Jean-Luc Verdeil Olivier Monteuuis 《Trees - Structure and Function》2012,26(3):1031-1044
Morphological and histocytological characteristics of Acacia mangium shoot apical meristems (SAMs) were assessed in natural and in vitro conditions in relation to heteroblasty. In the natural
environment, SAMs with a mature-phyllode morphology were much bigger, contained more cells with larger vacuolated area, or
vacuome, and lower nucleoplasmic ratios than those from the juvenile type (Juv). In these latter, nuclei appeared more voluminous,
evenly and lightly stained, with clearly distinguishable nucleolei and less abundant chromocenters. In vitro, where reversions
from mature to juvenile morphological traits do occur unpredictably, heteroblasty was less obvious in the SAM characteristics
examined. In vitro SAMs corresponding to the juvenile and mature types showed similarities with outdoor Juv SAMs, but could
be distinguished from these latter by a much larger vacuome that might be induced by the culture conditions. These findings
encourage pursuing the investigations at the chromatin and nucleolus level in SAM zones where heteroblasty-related differences
have been detected. 相似文献
957.
958.
Rolland RM Parks SE Hunt KE Castellote M Corkeron PJ Nowacek DP Wasser SK Kraus SD 《Proceedings. Biological sciences / The Royal Society》2012,279(1737):2363-2368
Baleen whales (Mysticeti) communicate using low-frequency acoustic signals. These long-wavelength sounds can be detected over hundreds of kilometres, potentially allowing contact over large distances. Low-frequency noise from large ships (20-200 Hz) overlaps acoustic signals used by baleen whales, and increased levels of underwater noise have been documented in areas with high shipping traffic. Reported responses of whales to increased noise include: habitat displacement, behavioural changes and alterations in the intensity, frequency and intervals of calls. However, it has been unclear whether exposure to noise results in physiological responses that may lead to significant consequences for individuals or populations. Here, we show that reduced ship traffic in the Bay of Fundy, Canada, following the events of 11 September 2001, resulted in a 6 dB decrease in underwater noise with a significant reduction below 150 Hz. This noise reduction was associated with decreased baseline levels of stress-related faecal hormone metabolites (glucocorticoids) in North Atlantic right whales (Eubalaena glacialis). This is the first evidence that exposure to low-frequency ship noise may be associated with chronic stress in whales, and has implications for all baleen whales in heavy ship traffic areas, and for recovery of this endangered right whale population. 相似文献
959.
M Roustit S Blaise C Arnaud M Hellmann C Millet D Godin-Ribuot B Dufournet J Boutonnat C Ribuot JL Cracowski 《PloS one》2012,7(7):e40792
Introduction
The treatment of scleroderma-related digital ulcers is challenging. The oral endothelin receptor antagonist (ERA) bosentan has been approved but it may induce liver toxicity. The objective of this study was to test whether ERAs bosentan and sitaxentan could be locally delivered using iontophoresis.Methods
Cathodal and anodal iontophoresis of bosentan and sitaxentan were performed on anaesthetized rat hindquarters without and during endothelin-1 infusion. Skin blood flow was quantified using laser-Doppler imaging and cutaneous tolerability was assessed. Iontophoresis of sitaxentan (20 min, 20 or 100 µA) was subsequently performed on the forearm skin of healthy men (n = 5).Results
In rats neither bosentan nor sitaxentan increased skin blood flux compared to NaCl. When simultaneously infusing endothelin-1, cathodal iontophoresis of sitaxentan increased skin blood flux compared to NaCl (AUC0–20 were 44032.2±12277 and 14957.5±23818.8 %BL.s, respectively; P = 0.01). In humans, sitaxentan did not significantly increase skin blood flux as compared to NaCl. Iontophoresis of ERAs was well tolerated both in animals and humans.Conclusions
This study shows that cathodal iontophoresis of sitaxentan but not bosentan partially reverses endothelin-induced skin vasoconstriction in rats, suggesting that sitaxentan diffuses into the dermis. However, sitaxentan does not influence basal skin microvascular tone in rats or in humans. 相似文献960.
H Janes N Frahm A Decamp M Rolland E Gabriel J Wolfson T Hertz E Kallas P Goepfert DP Friedrich L Corey JI Mullins MJ McElrath P Gilbert 《PloS one》2012,7(8):e43396