全文获取类型
收费全文 | 186篇 |
免费 | 1篇 |
专业分类
系统科学 | 4篇 |
教育与普及 | 1篇 |
理论与方法论 | 3篇 |
现状及发展 | 27篇 |
研究方法 | 30篇 |
综合类 | 121篇 |
自然研究 | 1篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 17篇 |
2011年 | 31篇 |
2010年 | 6篇 |
2009年 | 3篇 |
2008年 | 22篇 |
2007年 | 12篇 |
2006年 | 13篇 |
2005年 | 14篇 |
2004年 | 14篇 |
2003年 | 17篇 |
2002年 | 11篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
排序方式: 共有187条查询结果,搜索用时 296 毫秒
11.
Chasman DI Schürks M Anttila V de Vries B Schminke U Launer LJ Terwindt GM van den Maagdenberg AM Fendrich K Völzke H Ernst F Griffiths LR Buring JE Kallela M Freilinger T Kubisch C Ridker PM Palotie A Ferrari MD Hoffmann W Zee RY Kurth T 《Nature genetics》2011,43(7):695-698
Migraine is a common, heterogeneous and heritable neurological disorder. Its pathophysiology is incompletely understood, and its genetic influences at the population level are unknown. In a population-based genome-wide analysis including 5,122 migraineurs and 18,108 non-migraineurs, rs2651899 (1p36.32, PRDM16), rs10166942 (2q37.1, TRPM8) and rs11172113 (12q13.3, LRP1) were among the top seven associations (P < 5 × 10(-6)) with migraine. These SNPs were significant in a meta-analysis among three replication cohorts and met genome-wide significance in a meta-analysis combining the discovery and replication cohorts (rs2651899, odds ratio (OR) = 1.11, P = 3.8 × 10(-9); rs10166942, OR = 0.85, P = 5.5 × 10(-12); and rs11172113, OR = 0.90, P = 4.3 × 10(-9)). The associations at rs2651899 and rs10166942 were specific for migraine compared with non-migraine headache. None of the three SNP associations was preferential for migraine with aura or without aura, nor were any associations specific for migraine features. TRPM8 has been the focus of neuropathic pain models, whereas LRP1 modulates neuronal glutamate signaling, plausibly linking both genes to migraine pathophysiology. 相似文献
12.
Dobbins SE Broderick P Melin B Feychting M Johansen C Andersson U Brännström T Schramm J Olver B Lloyd A Ma YP Hosking FJ Lönn S Ahlbom A Henriksson R Schoemaker MJ Hepworth SJ Hoffmann P Mühleisen TW Nöthen MM Moebus S Eisele L Kosteljanetz M Muir K Swerdlow A Simon M Houlston RS 《Nature genetics》2011,43(9):825-827
To identify susceptibility loci for meningioma, we conducted a genome-wide association study of 859 affected individuals (cases) and 704 controls with validation in two independent sample sets totaling 774 cases and 1,764 controls. We identified a new susceptibility locus for meningioma at 10p12.31 (MLLT10, rs11012732, odds ratio = 1.46, P(combined) = 1.88 × 10(-14)). This finding advances our understanding of the genetic basis of meningioma development. 相似文献
13.
Metallurgy: high nickel release from 1- and 2-euro coins 总被引:1,自引:0,他引:1
The amount of nickel is regulated in European products that come into direct and prolonged contact with human skin because this metal may cause contact allergy, particularly hand eczema. Here we show that 1- and 2-euro coins induce positive skin-test reactions in sensitized individuals and release 240-320-fold more nickel than is allowed under the European Union Nickel Directive. A factor contributing to this high release of nickel is corrosion due to the bimetallic structure of these coins, which generates a galvanic potential of 30-40 mV in human sweat. 相似文献
14.
Zooxanthellae, endosymbiotic algae of reef-building corals, substantially contribute to the high gross primary production of coral reefs, but corals exude up to half of the carbon assimilated by their zooxanthellae as mucus. Here we show that released coral mucus efficiently traps organic matter from the water column and rapidly carries energy and nutrients to the reef lagoon sediment, which acts as a biocatalytic mineralizing filter. In the Great Barrier Reef, the dominant genus of hard corals, Acropora, exudes up to 4.8 litres of mucus per square metre of reef area per day. Between 56% and 80% of this mucus dissolves in the reef water, which is filtered through the lagoon sands. Here, coral mucus is degraded at a turnover rate of at least 7% per hour. Detached undissolved mucus traps suspended particles, increasing its initial organic carbon and nitrogen content by three orders of magnitude within 2 h. Tidal currents concentrate these mucus aggregates into the lagoon, where they rapidly settle. Coral mucus provides light energy harvested by the zooxanthellae and trapped particles to the heterotrophic reef community, thereby establishing a recycling loop that supports benthic life, while reducing loss of energy and nutrients from the reef ecosystem. 相似文献
15.
Requirement of Src kinases Lyn, Hck and Fgr for BCR-ABL1-induced B-lymphoblastic leukemia but not chronic myeloid leukemia 总被引:16,自引:0,他引:16
Hu Y Liu Y Pelletier S Buchdunger E Warmuth M Fabbro D Hallek M Van Etten RA Li S 《Nature genetics》2004,36(5):453-461
The Abl kinase inhibitor imatinib mesylate is the preferred treatment for Philadelphia chromosome-positive (Ph(+)) chronic myeloid leukemia (CML) in chronic phase but is much less effective in CML blast crisis or Ph(+) B-cell acute lymphoblastic leukemia (B-ALL). Here, we show that Bcr-Abl activated the Src kinases Lyn, Hck and Fgr in B-lymphoid cells. BCR-ABL1 retrovirus-transduced marrow from mice lacking all three Src kinases efficiently induced CML but not B-ALL in recipients. The kinase inhibitor CGP76030 impaired the proliferation of B-lymphoid cells expressing Bcr-Abl in vitro and prolonged survival of mice with B-ALL but not CML. The combination of CGP76030 and imatinib was superior to imatinib alone in this regard. The biochemical target of CGP76030 in leukemia cells was Src kinases, not Bcr-Abl. These results implicate Src family kinases as therapeutic targets in Ph(+) B-ALL and suggest that simultaneous inhibition of Src and Bcr-Abl kinases may benefit individuals with Ph(+) acute leukemia. 相似文献
16.
Hypotrichosis simplex of the scalp is associated with nonsense mutations in CDSN encoding corneodesmosin 总被引:6,自引:0,他引:6
Levy-Nissenbaum E Betz RC Frydman M Simon M Lahat H Bakhan T Goldman B Bygum A Pierick M Hillmer AM Jonca N Toribio J Kruse R Dewald G Cichon S Kubisch C Guerrin M Serre G Nöthen MM Pras E 《Nature genetics》2003,34(2):151-153
We have identified nonsense mutations in the gene CDSN (encoding corneodesmosin) in three families suffering from hypotrichosis simplex of the scalp (HSS; OMIM 146520). CDSN, a glycoprotein expressed in the epidermis and inner root sheath (IRS) of hair follicles, is a keratinocyte adhesion molecule. Truncated CDSN aggregates were detected in the superficial dermis and at the periphery of hair follicles. Our findings suggest that CDSN is important in normal scalp hair physiology. 相似文献
17.
An important task in vision is to detect objects moving within a stationary scene. During normal viewing this is complicated by the presence of eye movements that continually scan the image across the retina, even during fixation. To detect moving objects, the brain must distinguish local motion within the scene from the global retinal image drift due to fixational eye movements. We have found that this process begins in the retina: a subset of retinal ganglion cells responds to motion in the receptive field centre, but only if the wider surround moves with a different trajectory. This selectivity for differential motion is independent of direction, and can be explained by a model of retinal circuitry that invokes pooling over nonlinear interneurons. The suppression by global image motion is probably mediated by polyaxonal, wide-field amacrine cells with transient responses. We show how a population of ganglion cells selective for differential motion can rapidly flag moving objects, and even segregate multiple moving objects. 相似文献
18.
Markus Schwaninger 《Systemic Practice and Action Research》1990,3(3):249-264
Managers are facing new problems in their quest for organizational fitness. With environments of growing complexity, foresight, adaptability, and learning become critical features for a social system to survive and develop. Established models of organizational control are insufficient to cope with this proliferating complexity. The science of cybernetics provides powerful models to master this key challenge to management. The present article offers a synthesis of Beer's Viable System Model (VSM) and a multilevel concept of organizational fitness, based on recent progress made in the field of planning theory. 相似文献
19.
Astrid Wichmann Markus Kuhn Kay Hoeksema Ulrich Hoppe 《Cellular and molecular life sciences : CMLS》1992,48(1):1-3
Ethical principles and guidelines for scientific experiments on animals 相似文献
20.
Raghoebarsing AA Smolders AJ Schmid MC Rijpstra WI Wolters-Arts M Derksen J Jetten MS Schouten S Sinninghe Damsté JS Lamers LP Roelofs JG Op den Camp HJ Strous M 《Nature》2005,436(7054):1153-1156
Wetlands are the largest natural source of atmospheric methane, the second most important greenhouse gas. Methane flux to the atmosphere depends strongly on the climate; however, by far the largest part of the methane formed in wetland ecosystems is recycled and does not reach the atmosphere. The biogeochemical controls on the efficient oxidation of methane are still poorly understood. Here we show that submerged Sphagnum mosses, the dominant plants in some of these habitats, consume methane through symbiosis with partly endophytic methanotrophic bacteria, leading to highly effective in situ methane recycling. Molecular probes revealed the presence of the bacteria in the hyaline cells of the plant and on stem leaves. Incubation with (13)C-methane showed rapid in situ oxidation by these bacteria to carbon dioxide, which was subsequently fixed by Sphagnum, as shown by incorporation of (13)C-methane into plant sterols. In this way, methane acts as a significant (10-15%) carbon source for Sphagnum. The symbiosis explains both the efficient recycling of methane and the high organic carbon burial in these wetland ecosystems. 相似文献