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41.
Yacine Hemar Li Jiang Cheng Christine M. Oliver Luz Sanguansri Maryann Augustin 《Food biophysics》2010,5(2):120-127
The suitability of water-in-oil-in-water multiple emulsions to encapsulate resveratrol was assessed. Multiple emulsions were
prepared by emulsifying a primary emulsion (40 wt.%) in water containing 0.5 wt.% sodium caseinate and 0.1 M NaCl. Four primary
emulsions of canola oil (20 wt.%) stabilized by 8 wt.% polyglycerol polyricinoleate were chosen. The dispersed phase of the
primary emulsions contained 0.1 M NaCl and either water, 20 wt.% ethanol in water, 2.5 wt.% whey protein isolate (WPI) in
water, or 2.5 wt.% WPI and 5 wt.% gelatine in water. Resveratrol was incorporated into these primary emulsions at 0.25 wt.%
to give a final 0.02 wt.% resveratrol in the multiple emulsions. Slight increase in particle size with storage at 23 °C for
up to 2 weeks was observed. Further, less than 10% of the total encapsulated resveratrol is released to the external, continuous,
aqueous phase. This work demonstrates the potential of multiple emulsions to encapsulate resveratrol for food applications. 相似文献
42.
Summary We introduce a correction for covariate measurement error in nonparametric regression applied to longitudinal binary data arising from a study on human sleep. The data have been surveyed to investigate the association of some hormonal levels and the probability of being asleep. The hormonal effect is modeled flexibly while we account for the error‐prone measurement of its concentration in the blood and the longitudinal character of the data. We present a fully Bayesian treatment utilizing Markov chain Monte Carlo inference techniques, and also introduce block updating to improve sampling and computational performance in the binary case. Our model is partly inspired by the relevance vector machine with radial basis functions, where usually very few basis functions are automatically selected for fitting the data. In the proposed approach, we implement such data‐driven complexity regulation by adopting the idea of Bayesian model averaging. Besides the general theory and the detailed sampling scheme, we also provide a simulation study for the Gaussian and the binary cases by comparing our method to the naive analysis ignoring measurement error. The results demonstrate a clear gain when using the proposed correction method, particularly for the Gaussian case with medium and large measurement error variances, even if the covariate model is misspecified. 相似文献
43.
m-AAA protease-driven membrane dislocation allows intramembrane cleavage by rhomboid in mitochondria 下载免费PDF全文
Maturation of cytochrome c peroxidase (Ccp1) in mitochondria occurs by the subsequent action of two conserved proteases in the inner membrane: the m-AAA protease, an ATP-dependent protease degrading misfolded proteins and mediating protein processing, and the rhomboid protease Pcp1, an intramembrane cleaving peptidase. Neither the determinants preventing complete proteolysis of certain substrates by the m-AAA protease, nor the obligatory requirement of the m-AAA protease for rhomboid cleavage is currently understood. Here, we describe an intimate and unexpected functional interplay of both proteases. The m-AAA protease mediates the ATP-dependent membrane dislocation of Ccp1 independent of its proteolytic activity. It thereby ensures the correct positioning of Ccp1 within the membrane bilayer allowing intramembrane cleavage by rhomboid. Decreasing the hydrophobicity of the Ccp1 transmembrane segment facilitates its dislocation from the membrane and renders rhomboid cleavage m-AAA protease-independent. These findings reveal for the first time a non-proteolytic function of the m-AAA protease during mitochondrial biogenesis and rationalise the requirement of a preceding step for intramembrane cleavage by rhomboid. 相似文献
44.
Jakob Augustin Donald Blomqvist Tibor Szép Zoltán D. Szabó Richard H. Wagner 《Journal of Ornithology》2007,148(2):189-198
Genetic parentage studies of socially monogamous birds reveal a widespread prevalence of extra-pair paternity. Variation in
extra-pair paternity among individuals may depend on how different individuals benefit from extra-pair fertilisations and
on the opportunity to pursue extra-pair copulations. A long-term study of sand martins (Riparia riparia) in Hungary allowed us to examine patterns of extra-pair fertilisations in a large colony of over 3,000 breeding pairs with
many known age individuals. We used multi-locus DNA fingerprinting to determine whether extra-pair fertilisations occur when
females are paired to (1) presumably low quality mates, or (2) genetically similar or dissimilar mates, and whether extra-pair
fertilisations result in offspring of higher quality. Extra-paternal young were found in 38% of 47 broods and comprised 19%
of 190 offspring. Males that lost paternity did not differ significantly from others in age or body condition. Social mates
of broods containing extra-pair offspring did not differ in genetic similarity from pairs without extra-pair offspring. Furthermore,
there was no significant difference in body condition between extra-pair young and their maternal half-siblings. We were unable
to assign paternity and therefore cannot exclude the possibility that extra-pair males differed from the within-pair males
they cuckolded, in age, body condition or genetic similarity with the female. We found a positive relationship between paternity
losses and breeding density, suggesting that low breeding density may constrain opportunities for seeking extra-pair copulations. 相似文献
45.
Background
Paulinella chromatophora is a freshwater filose amoeba with photosynthetic endosymbionts (chromatophores) of cyanobacterial origin that are closely related to free-living Prochlorococcus and Synechococcus species (PS-clade). Members of the PS-clade of cyanobacteria contain a proteobacterial form 1A RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) that was acquired by horizontal gene transfer (HGT) of a carboxysomal operon. In rDNA-phylogenies, the Paulinella chromatophore diverged basal to the PS-clade, raising the question whether the HGT occurred before or after the split of the chromatophore ancestor. 相似文献46.
Karen CM Moraes Lívia F Diniz Maria Terezinha Bahia 《Memórias do Instituto Oswaldo Cruz》2015,110(2):181-191
Chagas disease, caused by the intracellular protozoan Trypanosoma
cruzi, is a serious health problem in Latin America. During this
parasitic infection, the heart is one of the major organs affected. The pathogenesis
of tissue remodelling, particularly regarding cardiomyocyte behaviour after parasite
infection and the molecular mechanisms that occur immediately following parasite
entry into host cells are not yet completely understood. When cells are infected with
T. cruzi, they develop an inflammatory response, in which
cyclooxygenase-2 (COX-2) catalyses rate-limiting steps in the arachidonic acid
pathway. However, how the parasite interaction modulates COX-2 activity is poorly
understood. In this study, the H9c2 cell line was used as our model and we
investigated cellular and biochemical aspects during the initial 48 h of parasitic
infection. Oscillatory activity of COX-2 was observed, which correlated with the
control of the pro-inflammatory environment in infected cells. Interestingly,
subcellular trafficking was also verified, correlated with the control of Cox-2 mRNA
or the activated COX-2 protein in cells, which is directly connected with the
assemble of stress granules structures. Our collective findings suggest that in the
very early stage of the T. cruzi-host cell interaction, the parasite
is able to modulate the cellular metabolism in order to survives. 相似文献
47.
Cíntia Júnia Monteiro Suianne Letícia Antunes Mota Lívia de Figueiredo Diniz Maria Terezinha Bahia Karen CM Moraes 《Memórias do Instituto Oswaldo Cruz》2015,110(8):996-1002
Chagas disease, which is caused by the intracellular protozoanTrypanosoma
cruzi, is a serious health problem in Latin America. The heart is one of
the major organs affected by this parasitic infection. The pathogenesis of tissue
remodelling, particularly regarding cardiomyocyte behaviour after parasite infection,
and the molecular mechanisms that occur immediately following parasite entry into
host cells are not yet completely understood. Previous studies have reported that the
establishment of parasitism is connected to the activation of the
phosphatidylinositol-3 kinase (PI3K), which controls important steps in cellular
metabolism by regulating the production of the second messenger
phosphatidylinositol-3,4,5-trisphosphate. Particularly, the tumour suppressor PTEN is
a negative regulator of PI3K signalling. However, mechanistic details of the
modulatory activity of PTEN on Chagas disease have not been elucidated. To address
this question, H9c2 cells were infected with T. cruzi Berenice 62
strain and the expression of a specific set of microRNAs (miRNAs) were investigated.
Our cellular model demonstrated that miRNA-190b is correlated to the decrease of
cellular viability rates by negatively modulating PTEN protein expression in
T. cruzi-infected cells. 相似文献
48.
Veiko Uri Krista LõhmusÜlo Mander Ivika OstonenJürgen Aosaar Martin MaddisonHeljä-Sisko Helmisaari Jürgen Augustin 《Ecological Engineering》2011,37(6):920-930
Short-rotation energy forestry is one of the potential ways for management of abandoned agricultural areas. It helps sequestrate carbon and mitigate human-induced climate changes. Owing to symbiotic dinitrogen (N2) fixation by actinomycetes and the soil fertilizing capacity and fast biomass growth of grey alders, the latter can be suitable species for short-rotation forestry. In our study of a young grey alder stand (Alnus incana (L.) Moench) on abandoned arable land in Estonia we tested the following hypotheses: (1) afforestation of abandoned agricultural land by grey alder significantly affects the soil nitrogen (N) status already during the first rotation period; (2) input of symbiotic fixation covers an essential part of the plant annual N demand of the stand; (3) despite a considerable N input into the ecosystem of a young alder stand, there will occur no significant environmental hazards (N leaching or N2O emissions). The first two hypotheses can be accepted: there was a significant increase in N and C content in the topsoil (from 0.11 to 0.14%, and from 1.4 to 1.7%, respectively), and N fixation (151.5 kg N ha−1 yr−1) covered about 74% of the annual N demand of the stand. The third hypothesis met support as well: N2O emissions (0.5 kg N ha−1 yr−1) were low, while most of the annual gaseous N losses were in the form of N2 (73.8 kg N ha−1 yr−1). Annual average NO3-N leaching was 15 kg N ha−1 yr−1 but the N that leached from topsoil accumulated in deeper soil layers. The soil acidifying effect of alders was clearly evident; during the 14-year period soil acidity increased 1.3 units in the upper 0-10 cm topsoil layer. 相似文献
49.
Kaido SoosaarÜlo Mander Martin MaddisonArno Kanal Ain KullKrista Lõhmus Jaak TruuJürgen Augustin 《Ecological Engineering》2011,37(1):40-53
We studied greenhouse gas (GHG) fluxes in two differently loaded riparian Alnus incana-dominated forests in agricultural landscapes of southern Estonia: a 33-year-old stand in Porijõgi, in which the uphill agricultural activities had been abandoned since the middle of the 1990s, and a 50-year-old stand in Viiratsi, which still receives polluted lateral flow from uphill fields fertilized with pig slurry. In Porijõgi, closed-chamber based sampling lasted from October 2001 to October 2009, whereas in Viiratsi the sampling period was from November 2003 to October 2009. Both temporal and spatial variations in all GHG gas fluxes were remarkable. Local differences in GHG fluxes between micro-sites (“Edge”, “Dry” and “Wet” in Porijõgi, and “Wet”, “Slope” and “Dry” in Viiratsi) were sometimes greater than those between sites. Median values of GHG fluxes from both sites over the whole study period and all microsites did not differ significantly, being 45 and 42 mg CO2-C m−2 h−1, 8 and 0.5 μg CH4-C m−2 h−1, 1.0 and 2.1 mg N2-N m−2 h−1, and 5 and 9 μg N2O-N m−2 h−1, in Porijõgi and Viiratsi, respectively. The N2:N2O ratio in Viiratsi (40-1200) was lower than in Porijõgi (10-7600). The median values-based estimation of the Global Warming Potential of CH4 and N2O was 19 and 185 kg CO2 equivalents (eq) ha−1 yr−1 in Porijõgi and −14 and 336 kg CO2 eq ha−1 yr−1 in Viiratsi, respectively. A significant Spearman rank correlation was found between the mean monthly air temperature and CO2, CH4 and N2 fluxes in Porijõgi, and N2O flux in Viiratsi, and between the monthly precipitation and CH4 fluxes in both study sites. Higher groundwater level significantly increases CH4 emission and decreases CO2 and N2O emission, whereas higher soil temperature significantly increases N2O, CH4 and N2 emission values. In Porijõgi, GHG emissions did not display any discernable trend, whereas in Viiratsi a significant increase in CO2, N2, and N2O emissions has been found. This may be a result of the age of the grey alder stand, but may also be caused by the long-term nutrient load of this riparian alder stand, which indicates a need for the management of similar heavily loaded riparian alder stands. 相似文献
50.
Anna Wolc Jesus Arango Petek Settar Janet E Fulton Neil P O'Sullivan Rudolf Preisinger David Habier Rohan Fernando Dorian J Garrick Jack CM Dekkers 《遗传、选种与进化》2011,43(1):23