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81.
Janneke A. Cox Robert L. Lukande Sam Kalungi Eric Van Marck Koen Van de Vijver Andrew Kambugu Ann M. Nelson Robert Colebunders Yukari C. Manabe 《PloS one》2015,10(4)
Objective
The detection of urinary lipoarabinomannan (LAM), a mycobacterial cell wall component, is used to diagnose tuberculosis (TB). How LAM enters the urine is not known. To investigate if urinary LAM-positivity is the result of renal TB infection we correlated the outcomes of urinary LAM-antigen testing to renal histology in an autopsy cohort of hospitalized, Ugandan, HIV-infected adults.Methods
We performed a complete autopsy, including renal sampling, in HIV-infected adults that died during hospitalization after written informed consent was obtained from the next of kin. Urine was collected postmortem through post-mortem catheterisation or by bladder puncture and tested for LAM with both a lateral flow assay (LFA) and an ELISA assay. Two pathologists assessed the kidney histology. We correlated the LAM-assay results and the histology findings.Results
Of the 13/36 (36%) patients with a positive urinary LAM ELISA and/or LFA, 8/13 (62%) had renal TB. The remaining 5 LAM-positive patients had disseminated TB without renal involvement. Of the 23 LAM-negative patients, 3 had disseminated TB without renal involvement. The remaining LAM-negative patients had no TB infection and died mostly of fungal and bacterial infections. LAM LFA had a sensitivity of 81% and specificity of 100% to diagnose TB at any location, and the LAM ELISA a sensitivity of 63% and a specificity of 100%. 54% (7/13) LAM LFA-positive patients were not on anti-TB treatment at the time of death.Conclusion
Renal TB infection explained LAM-positivity in the majority of patients. Patients with disseminated TB without renal involvement can also be diagnosed with LAM. This suggests that other mechanisms that lead to urinary LAM-positivity exist in a minority of patients. 相似文献82.
Maryam Yazdani Foshtomi Ulrike Braeckman Sofie Derycke Melanie Sapp Dirk Van Gansbeke Koen Sabbe Anne Willems Magda Vincx Jan Vanaverbeke 《PloS one》2015,10(6)
Objectives
The marine benthic nitrogen cycle is affected by both the presence and activity of macrofauna and the diversity of N-cycling microbes. However, integrated research simultaneously investigating macrofauna, microbes and N-cycling is lacking. We investigated spatio-temporal patterns in microbial community composition and diversity, macrofaunal abundance and their sediment reworking activity, and N-cycling in seven subtidal stations in the Southern North Sea.Spatio-Temporal Patterns of the Microbial Communities
Our results indicated that bacteria (total and β-AOB) showed more spatio-temporal variation than archaea (total and AOA) as sedimentation of organic matter and the subsequent changes in the environment had a stronger impact on their community composition and diversity indices in our study area. However, spatio-temporal patterns of total bacterial and β-AOB communities were different and related to the availability of ammonium for the autotrophic β-AOB. Highest bacterial richness and diversity were observed in June at the timing of the phytoplankton bloom deposition, while richness of β-AOB as well as AOA peaked in September. Total archaeal community showed no temporal variation in diversity indices.Macrofauna, Microbes and the Benthic N-Cycle
Distance based linear models revealed that, independent from the effect of grain size and the quality and quantity of sediment organic matter, nitrification and N-mineralization were affected by respectively the diversity of metabolically active β-AOB and AOA, and the total bacteria, near the sediment-water interface. Separate models demonstrated a significant and independent effect of macrofaunal activities on community composition and richness of total bacteria, and diversity indices of metabolically active AOA. Diversity of β-AOB was significantly affected by macrofaunal abundance. Our results support the link between microbial biodiversity and ecosystem functioning in marine sediments, and provided broad correlative support for the hypothesis that this relationship is modulated by macrofaunal activity. We hypothesized that the latter effect can be explained by their bioturbating and bio-irrigating activities, increasing the spatial complexity of the biogeochemical environment. 相似文献83.
Izabela M.D. Bastos Flávia Nader Motta Sébastien Charneau Jaime M. Santana Lionel Dubost Koen Augustyns Philippe Grellier 《Microbes and infection / Institut Pasteur》2010,12(6):457-466
Proteases play important roles in many biological processes of parasites, including their host interactions. In sleeping sickness, Trypanosoma brucei proteases released into the host bloodstream could hydrolyze host factors, such as hormones, contributing to the development of the disease's symptoms. In this study, we present the identification of the T. brucei prolyl oligopeptidase gene (poptb) and the characterization of its corresponding enzyme, POP Tb. Secondary structure predictions of POP Tb show a structural composition highly similar to other POPs. Recombinant POP Tb produced in E. coli was active and highly sensitive to inhibitors of Trypanosoma cruzi POP Tc80. These inhibitors, which prevent T. cruzi entry into non-phagocytic cells, arrested growth of the T. brucei bloodstream form in a dose-dependent manner. POP Tb hydrolyzes peptide hormones containing Pro or Ala at the P1 position at a slightly alkaline pH, and also cleaves type I collagen in vitro and native collagen present in rat mesentery. Furthermore, POP Tb is released into the bloodstream of T. brucei infected mice where it remains active. These data suggest that POP Tb might contribute to the pathogenesis of sleeping sickness. 相似文献
84.
Wendy M. Aartsen Koen W. R. van Cleef Lucie P. Pellissier Robert M. Hoek Rogier M. Vos Bas Blits Erich M. E. Ehlert Kamaljit S. Balaggan Robin R. Ali Joost Verhaagen Jan Wijnholds 《PloS one》2010,5(8)
Background
Müller cell gliosis occurs in various retinal pathologies regardless of the underlying cellular defect. Because activated Müller glial cells span the entire retina and align areas of injury, they are ideal targets for therapeutic strategies, including gene therapy.Methodology/Principal Findings
We used adeno-associated viral AAV2/6 vectors to transduce mouse retinas. The transduction pattern of AAV2/6 was investigated by studying expression of the green fluorescent protein (GFP) transgene using scanning-laser ophthalmoscopy and immuno-histochemistry. AAV2/6 vectors transduced mouse Müller glial cells aligning the retinal blood vessels. However, the transduction capacity was hindered by the inner limiting membrane (ILM) and besides Müller glial cells, several other inner retinal cell types were transduced. To obtain Müller glial cell-specific transgene expression, the cytomegalovirus (CMV) promoter was replaced by the glial fibrillary acidic protein (GFAP) promoter. Specificity and activation of the GFAP promoter was tested in a mouse model for retinal gliosis. Mice deficient for Crumbs homologue 1 (CRB1) develop gliosis after light exposure. Light exposure of Crb1−/− retinas transduced with AAV2/6-GFAP-GFP induced GFP expression restricted to activated Müller glial cells aligning retinal blood vessels.Conclusions/Significance
Our experiments indicate that AAV2 vectors carrying the GFAP promoter are a promising tool for specific expression of transgenes in activated glial cells. 相似文献85.
Koen Gillis Johan Gielis Hilde Peeters Emmy Dhooghe Jan Oprins 《Plant Cell, Tissue and Organ Culture》2007,91(2):115-123
A reliable protocol for mass propagation via somatic embryogenesis in mature bamboos has been established using pseudospikelets
of Bambusa balcooa. Fourty percent of the explants gave rise to multiple regenerants within 4 months. This conversion rate is sufficiently high
to use the process in commercial mass production. Further, shoot apical meristems can also be used as primary explants without
lost of efficiency.
Regenerated plants were uniform and identical to the mother plant and to plants obtained by axillary branching with respect
to growth characteristics and morphology. Furthermore, epigenetic changes could not be detected by Methylation Sensitive AFLP
(MSAP). During the complete process no changes in ploidy level could be observed.
The process allows for a cost reduction for this tropical bamboo for forestry of up to 57% compared to micropropagation via
axillary branching. For the first time, a reliable process based on somatic embryogenesis has been developed that is well
suited for commercial micropropagation of elite mature bamboos. 相似文献
86.
Rat cytomegalovirus gene expression in cardiac allograft recipients is tissue specific and does not parallel the profiles detected in vitro 下载免费PDF全文
87.
88.
89.
因为与世隔绝,岛屿生态和文化都十分脆弱,在现代化的浪潮中经受着比其它地方更加强烈的冲击,其命运的抉择也引起特别关注。 相似文献
90.
Experimental design criteria in phylogenetics: where to add taxa 总被引:1,自引:0,他引:1
Accurate phylogenetic inference is a topic of intensive research and debate and has been studied in response to many different factors: for example, differences in the method of reconstruction, the shape of the underlying tree, the substitution model, and varying quantities and types of data. Investigating whether the conditions used might lead to inaccurate inference has been attempted through elaborate data exploration but less attention has been given to creating a unified methodology to enable experimental designs in phylogenetic analysis to be improved and so avoid suboptimal conditions. Experimental design has been part of the field of statistics since the seminal work of Fisher in the early 20th century and a large body of literature exists on how to design optimum experiments. Here we investigate the use of the Fisher information matrix to decide between candidate positions for adding a taxon to a fixed topology, and introduce a parameter transformation that permits comparison of these different designs. This extension to Goldman (1998. Proc. R. Soc. Lond. B. 265: 1779-1786) thus allows investigation of "where to add taxa" in a phylogeny. We compare three different measures of the total information for selecting the position to add a taxon to a tree. Our methods are illustrated by investigating the behavior of the three criteria when adding a branch to model trees, and by applying the different criteria to two biological examples: a simplified taxon-sampling problem in the balsaminoid Ericales and the phylogeny of seed plants. 相似文献