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101.
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103.
Marcella Yu Darren Brown Chae Reed Shan Chung Jeff Lutman Eric Stefanich Anne Wong Jean-Philippe Stephan Robert Bayer 《MABS-AUSTIN》2012,4(4):475-487
The effector functions of therapeutic antibodies are strongly affected by the specific glycans added to the Fc domain during post-translational processing. Antibodies bearing high levels of N-linked mannose-5 glycan (Man5) have been reported to exhibit enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) compared with antibodies with fucosylated complex or hybrid glycans. To better understand the relationship between antibodies with high levels of Man5 and their biological activity in vivo, we developed an approach to generate substantially homogeneous antibodies bearing the Man5 glycoform. A mannosidase inhibitor, kifunensine, was first incorporated in the cell culture process to generate antibodies with a distribution of high mannose glycoforms. Antibodies were then purified and treated with a mannosidase for trimming to Man5 in vitro. This 2-step approach can consistently generate antibodies with > 99% Man5 glycan. Antibodies bearing varying levels of Man5 were studied to compare ADCC and Fcγ receptor binding, and they showed enhanced ADCC activity and increased binding affinity to the FcγRIIIA. In addition, the clearance rate of antibodies bearing Man8/9 and Man5 glycans was determined in a pharmacokinetics study in mice. When compared with historical data, the antibodies bearing the high mannose glycoform exhibited faster clearance rate compared with antibodies bearing the fucosylated complex glycoform, while the pharmacokinetic properties of antibodies with Man8/9 and Man5 glycoforms appeared similar. In addition, we identified the presence of a mannosidase in mouse serum that converted most Man8/9 to Man6 after 24 h. 相似文献
104.
Bruno Studer Torben Asp Ursula Frei Stephan Hentrup Helena Meally Aurélie Guillard Susanne Barth Hilde Muylle Isabel Roldán-Ruiz Philippe Barre Carole Koning-Boucoiran Gerda Uenk-Stunnenberg Oene Dolstra Leif Skøt Kirsten P. Skøt Lesley B. Turner Mervyn O. Humphreys Roland Kölliker Niels Roulund Klaus K. Nielsen Thomas Lübberstedt 《Molecular breeding : new strategies in plant improvement》2008,21(4):533-548
An expressed sequence tag (EST) library of the key grassland species perennial ryegrass (Lolium perenne L.) has been exploited as a resource for microsatellite marker development. Out of 955 simple sequence repeat (SSR) containing
ESTs, 744 were used for primer design. Primer amplification was tested in eight genotypes of L. perenne and L. multiflorum representing (grand-) parents of four mapping populations and resulted in 464 successfully amplified EST-SSRs. Three hundred
and six primer pairs successfully amplified products in the mapping population VrnA derived from two of the eight genotypes
included in the original screening and revealed SSR polymorphisms for 143 ESTs. Here, we report on 464 EST-derived SSR primer
sequences of perennial ryegrass established in laboratory assays, providing a dedicated tool for marker assisted breeding
and comparative mapping within and among forage and turf grasses.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
105.
106.
107.
Cédric Mabille Damien Pas Markus Aretz Frédéric Boulvain Stephan Schröder Anne-Christine da Silva 《Facies》2008,54(4):597-612
This study focuses on the base of the Eifelian stage and on the abandoned Ohlesberg quarry. The exposed section (92 m thick)
is related to the Lauch and Nohn formations. Petrographic study leads to the definition of 11 microfacies which are integrated
in a palaeogeographical model. It corresponds to a complex ramp setting where carbonate, mixed and siliciclastic deposits
coexist. The microfacies evolution is interpreted in terms of bathymetric and lateral variations, showing a general shallowing-upward
trend and transitions between carbonate-dominated and siliciclastic-dominated sedimentary domains. This interpretation is
supported by trends in magnetic susceptibility data. Even if the proximity to emerged areas appears to be the major influence
on magnetic susceptibility values, the influence of carbonate productivity and wave agitation is also noted. The Ohlesberg
section clearly points to the local and regional complex facies architecture, and advocates to variegated depositional environments
along the Mid-Eifelian High. 相似文献
108.
Diversity of plants in cocoa agroforests in the humid forest zone of Southern Cameroon 总被引:2,自引:1,他引:2
Denis J. Sonwa Bernard A. Nkongmeneck Stephan F. Weise Maturin Tchatat Akin A. Adesina Marc J. J. Janssens 《Biodiversity and Conservation》2007,16(8):2385-2400
In the humid forest zone of Southern Cameroon, farmers generally associate cocoa with native and exotic trees in complex agroforestry
systems. Despite the socio-economic and ecological importance of these systems, few studies have investigated their plant
composition. We investigated tree composition of cocoa agroforests along a gradient of market access, population density and
resource use intensity in the humid forest zone of southern Cameroon, comprising (i) the sub-region of Yaoundé, (ii) the sub-region
of Mbalmayo, and (iii) the sub-region of Ebolowa. Market access, population density and resource use intensity all decreased
from the first to the third sub-region. We quantified the diversity of tree species associated with cocoa within individual
agroforests, among agroforests in the same region, and among the three sub-regions, and classified the tree species according
to their main uses. A total of 9.1 ha belonging to 60 cocoa agroforests were inventoried in 12 villages. We encountered a
total of 206 tree species with an average of 21 tree species per agroforest. In the more urbanized area around Yaoundé, agroforests
were less diverse than in the other sub-regions. In all of the agroforests, food producing tree species tended to be more
frequent than other species. Two thirds of the food trees were native forest species and one third was introduced. From Ebolowa
to Yaoundé, the density of food producing trees doubled and the density of exotic food-producing species increased relative
to native species. Some local species producing high-value non-timber forest products were found in the agroforests, but their
density was far lower than that of exotic tree species. The agroforests also provide medicine, charcoal and other products
for household consumption and sale. We conclude that unless there are specific efforts to promote local forest tree species
in cocoa agroforests, these will progressively lose importance with increasing market access, population pressure and land
use intensity. 相似文献
109.
van der Toorn M Slebos DJ de Bruin HG Leuvenink HG Bakker SJ Gans RO Koëter GH van Oosterhout AJ Kauffman HF 《American journal of physiology. Lung cellular and molecular physiology》2007,292(5):L1211-L1218
Increased lung cell apoptosis and necrosis occur in patients with chronic obstructive pulmonary disease (COPD). Mitochondria are crucially involved in the regulation of these cell death processes. Cigarette smoke is the main risk factor for development of COPD. We hypothesized that cigarette smoke disturbs mitochondrial function, thereby decreasing the capacity of mitochondria for ATP synthesis, leading to cellular necrosis. This hypothesis was tested in both human bronchial epithelial cells and isolated mitochondria. Cigarette smoke extract exposure resulted in a dose-dependent inhibition of complex I and II activities. This inhibition was accompanied by decreases in mitochondrial membrane potential, mitochondrial oxygen consumption, and production of ATP. Cigarette smoke extract abolished the staurosporin-induced caspase-3 and -7 activities and induced a switch from epithelial cell apoptosis into necrosis. Cigarette smoke induced mitochondrial dysfunction, with compounds of cigarette smoke acting as blocking agents of the mitochondrial respiratory chain; loss of ATP generation leading to cellular necrosis instead of apoptosis is a new pathophysiological concept of COPD development. 相似文献
110.
Wim A. Ozinga Stephan M. Hennekens Joop H.J. Schamine Nina A.C. Smits Rene M. Bekker Christine Rmermann Leo Klime Jan P. Bakker Jan M. van Groenendael 《植被学杂志》2007,18(4):489-497
Questions: 1. Which plant traits and habitat characteristics best explain local above‐ground persistence of vascular plant species and 2. Is there a trade‐off between local above‐ground persistence and the ability for seed dispersal and below‐ground persistence in the soil seed bank? Locations: 845 long‐term permanent plots in terrestrial habitats across the Netherlands. Methods: We analysed the local above‐ground persistence of vascular plants in permanent plots (monitored once a year for ca. 16 year) with respect to functional traits and habitat preferences using survival statistics (Kaplan‐Meier analysis and Cox’ regression). These methods account for censored data and are rarely used in vegetation ecology. Results: Local above‐ground persistence is determined by both functional traits (especially the ability to form long‐lived clonal connections) and habitat preferences (especially nutrient requirements). Above‐ground persistence is negatively related to the ability for dispersal by wind and to the ability to accumulate a long‐term persistent soil seed bank (‘dispersal through time’) and is positively related to the ability for dispersal by water. Conclusions: Most species have a half‐life expectation over 15 years, which may contribute to time lags after changes in habitat quality or ‐configuration (‘extinction debt’). There is evidence for a trade‐off relationship between local above‐ground persistence and below‐ground seed persistence, while the relationship with dispersal in space is vector specific. The rate of species turnover increases with productivity. 相似文献