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81.
Rodolfo FaríasRodríguez Robert B. Mellor Carlos Arias Juan José PeñaCabriales 《Physiologia plantarum》1998,102(3):353-359
Nine cultivars of common bean were grown in the presence of a natural microflora without exogenous rhizobial inoculation. Nodules were harvested 30 days post planting (early flowering stage) and the presence of trehalose determined. Amounts present varied according to cultivar and were between 0.20 and 1.63 mg g−1 nodule dry weight. Rhizobial strains were isolated from the nodules of three selected cultivars (Canario 101, Flor de Mayo Bajio and Flor de Mayo 38). Trehalose levels in nodules produced after either mixed strain reinfection, or after axenic homologous reinfection or after axenic cross‐reinfection could be manipulated by applying drought stress. Mixed reinfection nodules from stressed plants accumulated between two and six times the trehalose concentration found in non‐stressed control plants. After axenic cross‐reinfection up to 48‐fold increases in nodule trehalose content were recorded during drought stress. Those cultivars exhibiting high nodule trehalose levels and/or a high degree of trehalose stimulation in response to drought stress also exhibited a high leaf relative water content and were also the most drought resistant. During drought stress nodule trehalase levels rose only slightly. 相似文献
82.
Salvador?Peiru Andres?Aguirre Florencia?Eberhardt Mauricio?Braia Rodolfo?Cabrera Hugo?G.?MenzellaEmail author 《Biotechnology for biofuels》2015,8(1):223
Background
Biodiesels produced from transesterification of vegetable oils have a major quality problem due to the presence of precipitates, which need to be removed to avoid clogging of filters and engine failures. These precipitates have been reported to be mostly composed of steryl glucosides (SGs), but so far industrial cost-effective methods to remove these compounds are not available. Here we describe a novel method for the efficient removal of SGs from biodiesel, based on the hydrolytic activity of a thermostable β-glycosidase obtained from Thermococcus litoralis.Results
A steryl glucosidase (SGase) enzyme from T. litoralis was produced and purified from Escherichia coli cultures expressing a synthetic gene, and used to treat soybean-derived biodiesel. Several optimization steps allowed for the selection of optimal reaction conditions to finally provide a simple and efficient process for the removal of SGs from crude biodiesel. The resulting biodiesel displayed filterability properties similar to distilled biodiesel according to the total contamination (TC), the cold soak filtration test (CSFT), filter blocking tendency (FBT), and cold soak filter blocking tendency (CSFBT) tests. The process was successfully scaled up to a 20 ton reactor, confirming its adaptability to industrial settings.Conclusions
The results presented in this work provide a novel path for the removal of steryl glucosides from biodiesel using a cost-effective, environmentally friendly and scalable enzymatic process, contributing to the adoption of this renewable fuel.83.
Increased urine podocyte‐associated messenger RNAs in severe obesity are evidence of podocyte injury 下载免费PDF全文
84.
Carla B. Andreucci José G. Cecatti Rodolfo C. Pacagnella Carla Silveira Mary A. Parpinelli Elton C. Ferreira Carina R. Angelini Juliana P. Santos Dulce M. Zanardi Jamile C. Bussadori Gustavo N. Cecchino Renato T. Souza Maria H. Sousa Maria L. Costa 《PloS one》2015,10(12)
Objective
to assess Female Sexual Function Index (FSFI) scores and delay to resume sexual activity associated with a previous severe maternal morbidity.Method
This was a multidimensional retrospective cohort study. Women who gave birth at a Brazilian tertiary maternity between 2008 and 2012 were included, with data extraction from the hospital information system. Those with potentially life-threatening conditions and maternal near miss episodes (severe maternal morbidity) were considered the exposed group. The control group was a random sample of women who had had uncomplicated pregnancy. Female sexual function was evaluated through FSFI questionnaire, and general and reproductive aspects were addressed through specific questions. Statistical analyses were performed using Mann-Whitney and Pearson´s Chi-square for bivariate analyses. Logistic regression was used to identify variables independently associated with lower FSFI scores.Results
638 women were included (315 at exposed and 323 at not exposed groups). The majority of women were under 30 years-old in the control group and between 30 and 46 years-old in the exposed group (p = 0.003). Women who experienced severe maternal morbidity (SMM) had statistically significant differences regarding cesarean section (82.4% versus 47.1% among deliveries without complications, p<0.001), and some previous pathological conditions. FSFI mean scores were similar among groups ranging from 24.39 to 24.42. It took longer for exposed women to resume sexual activity after index pregnancy (mean 84 days after SMM and 65 days for control group, p = 0.01). Multiple analyses showed no significant association of FSFI below cut-off value with any predictor.Conclusion
FSFI scores were not different in both groups. However, they were lower than expected. SMM delayed resumption of sexual activity after delivery, beyond postpartum period. However, the proportion of women in both groups having sex at 3 months after delivery was similar. Altered sexual response may be evaluated as one of possible long-term consequences after SMM episodes. Further studies on the growing population of women surviving severe maternal conditions might be worth for improvement of care for women. 相似文献85.
Jorge D. Carrillo-Brice?o Erin Maxwell Orangel A. Aguilera Rodolfo Sánchez Marcelo R. Sánchez-Villagra 《PloS one》2015,10(10)
The Urumaco stratigraphic sequence, western Venezuela, preserves a variety of paleoenvironments that include terrestrial, riverine, lacustrine and marine facies. A wide range of fossil vertebrates associated with these facies supports the hypothesis of an estuary in that geographic area connected with a hydrographic system that flowed from western Amazonia up to the Proto-Caribbean Sea during the Miocene. Here the elasmobranch assemblages of the middle Miocene to middle Pliocene section of the Urumaco sequence (Socorro, Urumaco and Codore formations) are described. Based on new findings, we document at least 21 taxa of the Lamniformes, Carcharhiniformes, Myliobatiformes and Rajiformes, and describe a new carcharhiniform species (†Carcharhinus caquetius sp. nov.). Moreover, the Urumaco Formation has a high number of well-preserved fossil Pristis rostra, for which we provide a detailed taxonomic revision, and referral in the context of the global Miocene record of Pristis as well as extant species. Using the habitat preference of the living representatives, we hypothesize that the fossil chondrichthyan assemblages from the Urumaco sequence are evidence for marine shallow waters and estuarine habitats. 相似文献
86.
Anna Santoro Javier Conde Morena Scotece Vanessa Abella Ana Lois Veronica Lopez Jesus Pino Rodolfo Gomez Juan J. Gomez-Reino Oreste Gualillo 《PloS one》2015,10(8)
Objectives
Osteoarthritis (OA) is a chronic joint disease, characterized by a progressive loss of articular cartilage. During OA, proinflammatory cytokines, such as interleukin IL-1, induce the expression of matrix metalloproteinases (MMPs) in chondrocytes, contributing thus to the extracellular matrix (ECM) degradation. Members of Serpine family, including plasminogen activator inhibitors have been reported to participate in ECM regulation. The aim of this study was to assess the expression of serpin peptidase inhibitor clade E member 2 (SERPINE2), under basal conditions and in response to increasing doses of IL-1α, in human cultured chondrocytes. We also examined the effects of SERPINE2 on IL-1α-induced MMP-13 expression. For completeness, the signaling pathway involved in this process was also explored.Methods
SERPINE2 mRNA and protein expression were evaluated by RT-qPCR and western blot analysis in human T/C-28a2 cell line and human primary chondrocytes. These cells were treated with human recombinant SERPINE2, alone or in combination with IL-1α. ERK 1/2, NFκB and AP-1 activation were assessed by western blot analysis.Results
Human cultured chondrocytes express SERPINE2 in basal condition. This expression increased in response to IL-1α stimulation. In addition, recombinant SERPINE2 induced a clear inhibition of MMP-13 expression in IL-1α-stimulated chondrocytes. This inhibitory effect is likely regulated through a pathway involving ERK 1/2, NF-κB and AP-1.Conclusions
Taken together, these data demonstrate that SERPINE2 might prevent cartilage catabolism by inhibiting the expression of MMP-13, one of the most relevant collagenases, involved in cartilage breakdown in OA. 相似文献87.
Pedro M. Meirelles Gilberto M. Amado-Filho Guilherme H. Pereira-Filho Hudson T. Pinheiro Rodrigo L. de Moura Jean-Christophe Joyeux Eric F. Mazzei Alex C. Bastos Robert A. Edwards Elizabeth Dinsdale Rodolfo Paranhos Eidy O. Santos Tetsuya Iida Kazuyoshi Gotoh Shota Nakamura Tomoo Sawabe Carlos E. Rezende Luiz M. R. Gadelha Jr Ronaldo B. Francini-Filho Cristiane Thompson Fabiano L. Thompson 《PloS one》2015,10(6)
Seamounts are considered important sources of biodiversity and minerals. However, their biodiversity and health status are not well understood; therefore, potential conservation problems are unknown. The mesophotic reefs of the Vitória-Trindade Seamount Chain (VTC) were investigated via benthic community and fish surveys, metagenomic and water chemistry analyses, and water microbial abundance estimations. The VTC is a mosaic of reef systems and includes fleshy algae dominated rhodolith beds, crustose coralline algae (CCA) reefs, and turf algae dominated rocky reefs of varying health levels. Macro-carnivores and larger fish presented higher biomass at the CCA reefs (4.4 kg per frame) than in the rhodolith beds and rocky reefs (0.0 to 0.1 kg per frame). A larger number of metagenomic sequences identified as primary producers (e.g., Chlorophyta and Streptophyta) were found at the CCA reefs. However, the rocky reefs contained more diseased corals (>90%) than the CCA reefs (~40%) and rhodolith beds (~10%). Metagenomic analyses indicated a heterotrophic and fast-growing microbiome in rocky reef corals that may possibly lead to unhealthy conditions possibly enhanced by environmental features (e.g. light stress and high loads of labile dissolved organic carbon). VTC mounts represent important hotspots of biodiversity that deserve further conservation actions. 相似文献
88.
Hillary S. Young Ted K. Raab Douglas J. McCauley Amy A. Briggs Rodolfo Dirzo 《植被学杂志》2010,21(6):1058-1068
Question: Cocos nucifera, the coconut palm, has a pantropical distribution and reaches near monodominance in many atolls, low lying islands and coastal regions. This paper examines the ecological correlation between C. nucifera abundance and changes in forest structure, floristic diversity and forest soil characteristics. Location: Palmyra Atoll NWR (USA), Central Pacific Ocean. Methods: Plant surveys were conducted on 83 transects (each 100 m2). All plants ≥5 cm in height were identified and counted; large plants were also measured and ground cover was surveyed. Major macronutrients, pH, macro‐elements/base cations, micronutrients and pedogenic elements, and thermodynamic stability levels were quantified from soil samples taken at each transect. Results: Even in a low diversity atoll environment, we found that high abundances of C. nucifera corresponded with pronounced differences in forest communities including: lower diversity of established trees and regenerating understorey; higher stem density and stand basal area; lower abundance of major macronutrients; and differences in macro and trace elements and energy content of soil organic matter. Historical natural experiments document that the expansion of C. nucifera was the likely causative agent of these changes. Discussion: Cumulatively, these data show that C. nucifera has important impacts on floristic, structural and soil characteristics of forests where it becomes dominant. Given the high proportion of tropical coastal areas in which C. nucifera is now naturalized and abundant, this likely has important implications for coastal forest diversity and structure. 相似文献
89.
Brucella abortus is the etiological agent of bovine brucellosis, an infectious disease of humans and cattle. Its pathogenesis is mainly based
on its ability to survive and multiply inside macrophages. It has been demonstrated that if B. abortus ferrochelatase cannot incorporate iron into protoporphyrin IX to synthesize heme, the intracellular replication and virulence
in mice is highly attenuated. Therefore, it can be hypothesized that the unavailability of iron could lead to the same attenuation
in B. abortus pathogenicity. Thus, the purpose of this work was to obtain a B. abortus derivative unable to keep an internal iron pool and test its ability to replicate under iron limitation. To achieve this,
we searched for iron-storage proteins in the genome of brucellae and found bacterioferritin (Bfr) as the sole ferritin encoded.
Then, a B. abortus bfr mutant was built up and its capacity to store iron and replicate under iron limitation was investigated. Results indicated
that B. abortus Bfr accounts for 70% of the intracellular iron content. Under iron limitation, the bfr mutant suffered from enhanced iron restriction with respect to wild type according to its growth retardation pattern, enhanced
sensitivity to oxidative stress, accelerated production of siderophores, and altered expression of membrane proteins. Nonetheless,
the bfr mutant was able to adapt and replicate even inside eukaryotic cells, indicating that B. abortus responds to internal iron starvation before sensing external iron availability. This suggests an active role of Bfr in controlling
iron homeostasis through the availability of Bfr-bound iron. 相似文献
90.
Ernesto A. Roman Pablo Rosi Mariano C. González Lebrero Rodolfo Wuilloud F. Luis González Flecha José M. Delfino Javier Santos 《Proteins》2010,78(13):2757-2768
In this work, we studied how an amphipathic peptide of the surface of the globular protein thioredoxin, TRX94‐108, acquires a native‐like structure when it becomes involved in an apolar interaction network. We designed peptide variants where the tendency to form α‐helical conformation is modulated by replacing each of the leucine amino acid residues by an alanine. The induction of structure caused by sodium dodecyl sulfate (SDS) binding was studied by capillary zone electrophoresis, circular dichroism, DOSY‐NMR, and molecular dynamics simulations (MDS). In addition, we analyzed the strength of the interaction between a C18 RP‐HPLC matrix and the peptides. The results presented here reveal that (a) critical elements in the sequence of the wild‐type peptide stabilize a SDS/peptide supramolecular cluster; (b) the hydrophobic nature of the interaction between SDS molecules and the peptide constrains the ensemble of conformations; (c) nonspecific apolar surfaces are sufficient to stabilize peptide secondary structure. Remarkably, MDS shed light on a contact network formed by a limited number of SDS molecules that serves as a structural scaffold preserving the helical conformation of this module. This mechanism might prevail when a peptide with low helical propensity is involved in structure consolidation. We suggest that folding of peptides sharing this feature does not require a preformed tightly‐packed protein core. Thus, the formation of specific tertiary interactions would be the consequence of peptide folding and not its cause. In this scenario, folding might be thought of as a process that includes unspecific rounds of structure stabilization guiding the protein to the native state. Proteins 2010. © 2010 Wiley‐Liss, Inc. 相似文献