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Amine oxidases (AOs) oxidize polyamines (PAs) to aldehydes, simultaneously producing the removed amine moiety and hydrogen peroxide (H2O2). AOs, which include copper-containing amine oxidases (CuAOs) and flavin-containing amine oxidases (PAOs), are stress-inducible enzymes involved in both PA homeostasis and H2O2 production. Here, we suggest that H2O2 derived from PAO-mediated PA catabolism has a role in inducing root xylem differentiation during plant stress responses, whereas its involvement in this event during plant development under physiological conditions is not suitably supported by the currently available data. Moreover, we show that spermidine (Spd) supply leads to a higher induction of cell death in wild-type (WT) tobacco (Nicotiana tabacum) plants as compared to tobacco plants over-expressing maize (Zea mays) PAO (S-ZmPAO) in the cell wall, in apparent contradiction with the already reported results obtained by the analysis of the corresponding WT and S-ZmPAO Spd-untreated plants. Considering this last observation, we propose that PAs diversely affect plant development and stress responses depending on the expression levels of AOs, which in turn may lead to different plant responses by altering the PAs/H2O2 balance. 相似文献
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A case of a female infant with karyotype 46,XX,r(21)/45,XX,-21 is reported. From comparison of the phenotypic anomalies with the other similar cases the large variability of the 21q- syndrome is evident. 相似文献
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Thomas J. Matthews Joseph P. Wayman Robert J. Whittaker Pedro Cardoso Julian P. Hume Ferran Sayol Konstantinos Proios Thomas E. Martin Benjamin Baiser Paulo A. V. Borges Yasuhiro Kubota Luiz dos Anjos Joseph A. Tobias Filipa C. Soares Xingfeng Si Ping Ding Chase D. Mendenhall Yong Chee Keita Sin Frank E. Rheindt Kostas A. Triantis François Guilhaumon David M. Watson Lluís Brotons Corrado Battisti Osanna Chu François Rigal 《Ecology letters》2023,26(6):965-982
Research on island species–area relationships (ISAR) has expanded to incorporate functional (IFDAR) and phylogenetic (IPDAR) diversity. However, relative to the ISAR, we know little about IFDARs and IPDARs, and lack synthetic global analyses of variation in form of these three categories of island diversity–area relationship (IDAR). Here, we undertake the first comparative evaluation of IDARs at the global scale using 51 avian archipelagic data sets representing true and habitat islands. Using null models, we explore how richness-corrected functional and phylogenetic diversity scale with island area. We also provide the largest global assessment of the impacts of species introductions and extinctions on the IDAR. Results show that increasing richness with area is the primary driver of the (non-richness corrected) IPDAR and IFDAR for many data sets. However, for several archipelagos, richness-corrected functional and phylogenetic diversity changes linearly with island area, suggesting that the dominant community assembly processes shift along the island area gradient. We also find that archipelagos with the steepest ISARs exhibit the biggest differences in slope between IDARs, indicating increased functional and phylogenetic redundancy on larger islands in these archipelagos. In several cases introduced species seem to have ‘re-calibrated’ the IDARs such that they resemble the historic period prior to recent extinctions. 相似文献
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Separated thyroid follicles in suspension culture invert in 5% serum. In some, the inversion is not complete in that a small normal follicle persists completely in the interior of an inverted follicle. In inverted follicles the lumens are distended and electron lucent. The bounding epithelial cells are stretched, have relatively few microvilli on the surface toward the medium but they have bundles of oriented microfilaments usually located near the lumen. The cells are connected together by tight junctions. When inverted follicles are punctured, the lumen shrinks, the cells retract and become cuboidal and microvilli reappear. Microfilaments persist at the luminal surface but no longer in oriented bundles. No appreciable extracellular matrix is present at the basal cell surface in contact with the lumen, but matrix is occasionally observed between cells. Since bundles of microfilaments like stress fibers are observed in the cells in suspension culture, the presence of stress fibers in cells in monolayer culture is probably not dependent on attachment but might be a reflection of the spreading of the attached cells. 相似文献
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Mariantonia Logozzi Rossella Di Raimo Francesca Properzi Stefano Barca Daniela F. Angelini Davide Mizzoni Mario Falchi Luca Battistini Stefano Fais 《Journal of enzyme inhibition and medicinal chemistry》2021,36(1):175
Recent findings have shown that nanovesicles preparations from either primary immune cells culture supernatants or plasma contain immunoglobulins, suggesting that a natural way of antibody production may be through exosome release. To verify this hypothesis, we used the OKT3 hybridoma clone, which produces a murine IgG2a monoclonal antibody used to reduce rejection in patients undergoing organ transplantation. We showed exosome-associated immunoglobulins in hybridoma supernatants, by Western blot, nanoscale flow cytometry and immunocapture-based ELISA. The OKT3-exo was also being able to trigger cytokines production in both CD4 and CD8 T cells. These results show that nanovesicles contain immunoglobulin and could be used for immunotherapy. These data could lead to a new approach to improve the effectiveness of therapeutic antibodies by exploiting their natural property to be expressed on nanovesicle membrane, that probably render them more stable and as a consequence more capable to interact with their specific ligand in the best way. 相似文献