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71.
Plant Performance in a Warmer World: General Responses of Plants from Cold, Northern Biomes and the Importance of Winter and Spring Events 总被引:10,自引:0,他引:10
During the past three decades the Earth has warmed with a rate unprecedented during the past 1000 years. There is already
ample evidence that this fast climate warming has affected a broad range of organisms, including plants. Plants from high-latitude
and high-altitude sites (‘cold biomes’) are especially sensitive to climate warming. In this paper we (1) review the response
in the phenology of plants, changes in their range and distribution, soil nutrient availability, and the effects on the structure
and dynamics of plant communities for cold, northern biomes; and (2) we show, by using data from an ongoing snow and temperature
manipulation experiment in northern Sweden, that also winter and spring events have a profound influence on plant performance.
Both long-term phenological data sets, experimental warming studies (performed in summer or year-round), natural gradient
studies and satellite images show that key phenological events are responsive to temperature increases and that recent climate
warming does indeed lead to changes in plant phenology. However, data from a warming and snow manipulation study that we are
conducting in northern Sweden show that plants respond differently to the various climatic scenarios that we had imposed on
these species and that especially winter and spring events have a profound impact. This indicates that it is necessary to
include several scenarios of both summer and winter climate change in experimental climate change studies, and that we need
detailed projections of future climate at a regional scale to be able to assess their impacts on natural ecosystems. There
is also ample evidence that the range shift of herbs and shrubs to more northern regions is for the vast majority of species
mainly caused by changes in the climate. This is in line with the observed ‘up-greening’ of northern tundra sites. These rapid
northern shifts in distribution of plants as a result of climate warming may have substantial consequences for the structure
and dynamics of high-latitude ecosystems. An analysis of warming studies at 9 tundra sites shows that heating during at least
3 years increased net N-mineralization from 0.32±0.31 (SE) g N m−2 yr−1 in the controls to 0.53±0.31 (SE) g N m−2 yr−1 in the heated plots (p<0.05), an increase of about 70%. Thus, warming leads to higher N availability in high-latitude northern tundra sites, but
the variability is substantial. Higher nutrient availability affects in turn the species composition of high-latitude sites,
which has important consequences for the carbon and water balance of these systems. 相似文献
72.
Increased susceptibility to isoproterenol-induced cardiac hypertrophy and impaired weight gain in mice lacking the histidine-rich calcium-binding protein 下载免费PDF全文
Jaehnig EJ Heidt AB Greene SB Cornelissen I Black BL 《Molecular and cellular biology》2006,26(24):9315-9326
The sarcoplasmic reticulum (SR) plays a critical role in excitation-contraction coupling by regulating the cytoplasmic calcium concentration of striated muscle. The histidine-rich calcium-binding protein (HRCBP) is expressed in the junctional SR, the site of calcium release from the SR. HRCBP is expressed exclusively in muscle tissues and binds calcium with low affinity and high capacity. In addition, HRCBP interacts with triadin, a protein associated with the ryanodine receptor and thought to be involved in calcium release. Its calcium binding properties, localization to the SR, and interaction with triadin suggest that HRCBP is involved in calcium handling by the SR. To determine the function of HRCBP in vivo, we inactivated HRC, the gene encoding HRCBP, in mice. HRC knockout mice exhibited impaired weight gain beginning at 11 months of age, which was marked by reduced skeletal muscle and fat mass, and triadin protein expression was upregulated in the heart of HRC knockout mice. In addition, HRC null mice displayed a significantly exaggerated response to the induction of cardiac hypertrophy by isoproterenol compared to their wild-type littermates. The exaggerated response of HRC knockout mice to the induction of cardiac hypertrophy is consistent with a regulatory role for HRCBP in calcium handling in vivo and suggests that mutations in HRC, in combination with other genetic or environmental factors, might contribute to pathological hypertrophy and heart failure. 相似文献
73.
Cornelissen JH Quested HM van Logtestijn RS Pérez-Harguindeguy N Gwynn-Jones D Díaz S Callaghan TV Press MC Aerts R 《Oecologia》2006,147(2):315-326
Plant traits have become popular as predictors of interspecific variation in important ecosystem properties and processes.
Here we introduce foliar pH as a possible new plant trait, and tested whether (1) green leaf pH or leaf litter pH correlates
with biochemical and structural foliar traits that are linked to biogeochemical cycling; (2) there is consistent variation
in green leaf pH or leaf litter pH among plant types as defined by nutrient uptake mode and higher taxonomy; (3) green leaf
pH can predict a significant proportion of variation in leaf digestibility among plant species and types; (4) leaf litter
pH can predict a significant proportion of variation in leaf litter decomposability among plant species and types. We found
some evidence in support of all four hypotheses for a wide range of species in a subarctic flora, although cryptogams (fern
allies and a moss) tended to weaken the patterns by showing relatively poor leaf digestibility or litter decomposability at
a given pH. Among seed plant species, green leaf pH itself explained only up to a third of the interspecific variation in
leaf digestibility and leaf litter up to a quarter of the interspecific variation in leaf litter decomposability. However,
foliar pH substantially improved the power of foliar lignin and/or cellulose concentrations as predictors of these processes
when added to regression models as a second variable. When species were aggregated into plant types as defined by higher taxonomy
and nutrient uptake mode, green-specific leaf area was a more powerful predictor of digestibility or decomposability than
any of the biochemical traits including pH. The usefulness of foliar pH as a new predictive trait, whether or not in combination
with other traits, remains to be tested across more plant species, types and biomes, and also in relation to other plant or
ecosystem traits and processes. 相似文献
74.
Mutations in the NB-ARC domain of I-2 that impair ATP hydrolysis cause autoactivation 总被引:12,自引:0,他引:12 下载免费PDF全文
Tameling WI Vossen JH Albrecht M Lengauer T Berden JA Haring MA Cornelissen BJ Takken FL 《Plant physiology》2006,140(4):1233-1245
Resistance (R) proteins in plants confer specificity to the innate immune system. Most R proteins have a centrally located NB-ARC (nucleotide-binding adaptor shared by APAF-1, R proteins, and CED-4) domain. For two tomato (Lycopersicon esculentum) R proteins, I-2 and Mi-1, we have previously shown that this domain acts as an ATPase module that can hydrolyze ATP in vitro. To investigate the role of nucleotide binding and hydrolysis for the function of I-2 in planta, specific mutations were introduced in conserved motifs of the NB-ARC domain. Two mutations resulted in autoactivating proteins that induce a pathogen-independent hypersensitive response upon expression in planta. These mutant forms of I-2 were found to be impaired in ATP hydrolysis, but not in ATP binding, suggesting that the ATP- rather than the ADP-bound state of I-2 is the active form that triggers defense signaling. In addition, upon ADP binding, the protein displayed an increased affinity for ADP suggestive of a change of conformation. Based on these data, we propose that the NB-ARC domain of I-2, and likely of related R proteins, functions as a molecular switch whose state (on/off) depends on the nucleotide bound (ATP/ADP). 相似文献
75.
Cornelissen C Lüscher-Firzlaff J Baron JM Lüscher B 《European journal of cell biology》2012,91(6-7):552-566
Cytokines are key to control cellular communication. Interleukin-31 (IL-31) was recently discovered as a new member of the IL-6 family of cytokines. IL-31 signals through a heterodimeric receptor composed of OSMR and IL-31RA, a complex that stimulates the JAK-STAT, the RAS/ERK and the PI3K/AKT signal transduction pathways. The available data suggests that IL-31 is important for both innate and adaptive immunity in tissues that are in close contact with the environment, i.e. the skin, the airways and the lung, and the lining of the intestine. Enhanced expression of IL-31 is associated with a number of diseases, including pruritic diseases such as atopic dermatitis, but also in allergy and inflammatory bowel disease. In these tissues IL-31 coordinates the interaction of different immune cells, including T-cells, mast cells, and eosinophils, with epithelial cells. In this review we have summarized the available data on IL-31 and its receptor, their expression pattern and how they are regulated. We describe the current state of knowledge of the involvement of IL-31 in diseases, both in humans and in mouse models. From these studies it is becoming clear that IL-31 plays an important role in the proper functioning of the skin and of airway and intestinal epithelia. The findings available suggest that IL-31 might be an interesting target for directed drug therapy. 相似文献
76.
V. G. Onipchenko M. I. Makarov A. A. Akhmetzhanova N. A. Soudzilovskaia F. U. Aibazova M. K. Elkanova A. V. Stogova J. H. C. Cornelissen 《Plant and Soil》2012,357(1-2):103-115
Background and aims
We ask how productivity responses of alpine plant communities to increased nutrient availability can be predicted from abiotic regime and initial functional type composition.Methods
We compared four Caucasian alpine plant communities (lichen heath, Festuca varia grassland, Geranium-Hedysarum meadow, snow bed community) forming a toposequence and contrasting in productivity and dominance structure for biomass responses to experimental fertilization (N, P, NP, Ca) and irrigation for 4–5?years.Results
The dominant plants in more productive communities monopolized added N and P, at the expense of their neighbors. In three out of four communities, N and P fertilizations gave greater aboveground biomass increase than N or P fertilization alone, indicating overall co-limitation of N and P, with N being most limiting. Relative biomass increase in NP treatment was negatively related to biomass in control plots across the four communities. Grasses often responded more vigorously to P, but sedges to N alone. Finally, we present one of the rare examples of a forb showing a strong N or NP response.Conclusion
Our findings will help improve our ability to predict community composition and biomass dynamics in cool ecosystems subject to changing nutrient availability as induced by climate or land-use changes. 相似文献77.
Luttmann R Bracewell DG Cornelissen G Gernaey KV Glassey J Hass VC Kaiser C Preusse C Striedner G Mandenius CF 《Biotechnology journal》2012,7(8):1040-1048
The following report with recommendations is the result of an expert panel meeting on soft sensor applications in bioprocess engineering that was organized by the Measurement, Monitoring, Modelling and Control (M3C) Working Group of the European Federation of Biotechnology - Section of Biochemical Engineering Science (ESBES). The aim of the panel was to provide an update on the present status of the subject and to identify critical needs and issues for the furthering of the successful development of soft sensor methods in bioprocess engineering research and for industrial applications, in particular with focus on biopharmaceutical applications. It concludes with a set of recommendations, which highlight current prospects for the extended use of soft sensors and those areas requiring development. 相似文献
78.
J Rusine S Jurriaans J van de Wijgert M Cornelissen B Kateera K Boer E Karita O Mukabayire M de Jong P Ondoa 《PloS one》2012,7(8):e42557
This study aimed at describing the genetic subtype distribution of HIV-1 strains circulating in Kigali and their epidemiological link with the HIV-1 strains from the five countries surrounding Rwanda. One hundred and thirty eight pol (RT and PR) sequences from 116 chronically- and 22 recently-infected antiretroviral therapy (ART)-naïve patients from Kigali were generated and subjected to HIV drug resistance (HIV-DR), phylogenetic and recombinant analyses in connection with 366 reference pol sequences from Rwanda, Burundi, Kenya, Democratic Republic of Congo, Tanzania and Uganda (Los Alamos database). Among the Rwandan samples, subtype A1 predominated (71.7%), followed by A1/C recombinants (18.1%), subtype C (5.8%), subtype D (2.9%), one A1/D recombinant (0.7%) and one unknown subtype (0.7%). Thirteen unique and three multiple A1/C recombinant forms were identified. No evidence for direct transmission events was found within the Rwandan strains. Molecular characteristics of HIV-1 were similar between chronically and recently-infected individuals and were not significantly associated with demographic or social factors. Our report suggests that the HIV-1 epidemic in Kigali is characterized by the emergence of A1/C recombinants and is not phylogenetically connected with the HIV-1 epidemic in the five neighboring countries. The relatively low level of transmitted HIV-DR mutations (2.9%) reported here indicates the good performance of the ART programme in Rwanda. However, the importance of promoting couples'' counseling, testing and disclosure during HIV prevention strategies is highlighted. 相似文献
79.
Seminal work in the early nineties revealed that the visual receptive field of neurons in cat primary visual cortex can change in location and size when artificial scotomas are applied. Recent work now suggests that these single neuron receptive field dynamics also pertain to the neuronal population receptive field (pRF) that can be measured in humans with functional magnetic resonance imaging (fMRI). To examine this further, we estimated the pRF in twelve healthy participants while masking the central portion of the visual field. We found that the pRF changes in location and size for two differently sized artificial scotomas, and that these pRF dynamics are most likely due to a combination of the neuronal receptive field position and size scatter as well as modulatory feedback signals from extrastriate visual areas. 相似文献
80.
van Dooremalen C Gerritsen L Cornelissen B van der Steen JJ van Langevelde F Blacquière T 《PloS one》2012,7(4):e36285