排序方式: 共有157条查询结果,搜索用时 31 毫秒
141.
Three-way junction DNA (TWJ-DNA, also known as 3WJ-DNA) is an alternative secondary DNA structure comprised of three duplex-DNAs that converge towards a single point, termed the branch point. This point is characterized by unique geometrical properties that make its specific targeting by synthetic small-molecules possible. Such a targeting has already been demonstrated in the solid state but not thoroughly biophysically investigated in solution. Herein, a set of simple biophysical assays has been developed to identify TWJ-specific small-molecule ligands; these assays, inspired by the considerable body of work that has been reported to characterize the interactions between small-molecules and other higher-order DNA (notably quadruplex-DNA), have been calibrated with a known non-specific DNA binder (the porphyrin TMPyP4) and validated via the study of a small series of triazacyclononane (TACN) derivatives (metal-free or not) and the identification of a fairly-affinic and exquisitely TWJ-selective candidate (a TACN-quinoline construct named TACN-Q). 相似文献
142.
Liu C Bai Y Chen Y Wang Y Sottejeau Y Liu L Li X Lingrel JB Malhotra D Cooper CJ Shapiro JI Xie ZJ Tian J 《The Journal of biological chemistry》2012,287(20):16390-16398
Decreases in cardiac Na/K-ATPase have been documented in patients with heart failure. Reduction of Na/K-ATPase α1 also contributes to the deficiency in cardiac contractility in animal models. Our previous studies demonstrate that reduction of cellular Na/K-ATPase causes cell growth inhibition and cell death in renal proximal tubule cells. To test whether reduction of Na/K-ATPase in combination with increased cardiotonic steroids causes cardiac myocyte death and cardiac dysfunction, we examined heart function in Na/K-ATPase α1 heterozygote knock-out mice (α1(+/-)) in comparison to wild type (WT) littermates after infusion of marinobufagenin (MBG). Adult cardiac myocytes were also isolated from both WT and α1(+/-) mice for in vitro experiments. The results demonstrated that MBG infusion increased myocyte apoptosis and induced significant left ventricle dilation in α1(+/-) mice but not in their WT littermates. Mechanistically, it was found that in WT myocytes MBG activated the Src/Akt/mTOR signaling pathway, which further increased phosphorylation of ribosome S6 kinase (S6K) and BAD (Bcl-2-associated death promoter) and protected cells from apoptosis. In α1(+/-) myocytes, the basal level of phospho-BAD is higher compared with WT myocytes, but MBG failed to induce further activation of the mTOR pathway. Reduction of Na/K-ATPase also caused the activation of caspase 9 but not caspase 8 in these cells. Using cultures of neonatal cardiac myocytes, we demonstrated that inhibition of the mTOR pathway by rapamycin also enabled MBG to activate caspase 9 and induce myocyte apoptosis. 相似文献
143.
144.
The article reports the finding of some late Paleocene (Thanetian) species of Phaeodarian Radiolaria in phosphorite concretions occurring in the Holmehus Formation of Denmark. These species are associated with a rich assemblage of diatoms and sparse spherical radiolarians. Phaeodarians are very well-preserved in celestobarite (BaSrSO4) and consist of representatives of the families Challengeridae (Challengerebium triangulovum nov. sp. and Challengerebium sp.) and particularly Medusettidae (Medusetta danica nov. sp. and M. densicostata nov. sp.), which are the most frequent. A new genus of medusettid phaeodarians (Pseudochallengeranium nov. gen.) is also described. 相似文献
145.
Murariu M Doumbia A Bonnaud L Dechief AL Paint Y Ferreira M Campagne C Devaux E Dubois P 《Biomacromolecules》2011,12(5):1762-1771
Metallic oxides have been successfully investigated for the recycling of polylactide (PLA) via catalyzed unzipping depolymerization allowing for the selective recovery of lactide monomer. In this contribution, a metallic oxide nanofiller, that is, ZnO, has been dispersed into PLA without detrimental polyester degradation yielding PLA/ZnO nanocomposites directly suitable for producing films and fibers. The nanocomposites were produced by melt-blending two different grades of PLA with untreated ZnO and surface-treated ZnO nanoparticles. The surface treatment by silanization proved to be necessary for avoiding the decrease in molecular weight and thermal and mechanical properties of the filled polyester matrix. Silane-treated ZnO nanoparticles yielded nanocomposites characterized by good mechanical performances (tensile strength in the interval from 55 to 65 MPa), improved thermal stability, and fine nanofiller dispersion, as evidenced by microscopy investigations. PLA/ZnO nanocomposites were further extruded in films and fibers, respectively, characterized by anti-UV and antibacterial properties. 相似文献
146.
Simultaneous multi-spectral,single-photon fluorescence imaging using a plasmonic colour filter array
Peter W. R. Connolly Jessica Valli Yash D. Shah Yoann Altmann James Grant Claudio Accarino Colin Rickman David R. S. Cumming Gerald S. Buller 《Journal of biophotonics》2021,14(7):e202000505
We present the first realisation of simultaneous multi-spectral fluorescence imaging using a single-photon avalanche diode (SPAD) array, where the spectral unmixing is facilitated by a plasmonic metasurface mosaic colour filter array (CFA). A 64 × 64 pixel format silicon SPAD array is used to record widefield fluorescence and brightfield data from four biological samples. A plasmonic metasurface composed of an arrangement of circular and elliptical nanoholes etched into an aluminium thin film deposited on a glass substrate provides the high transmission efficiency CFA, enabling a bespoke spectral unmixing algorithm to reconstruct high fidelity, full colour images from as few as ∼3 photons per pixel. This approach points the way toward real-time, single-photon sensitive multi-spectral fluorescence imaging. Furthermore, this is possible without additional bulky components such as a filter wheel, prism or diffraction grating, nor the need for multiple sample exposures or multiple detectors. 相似文献
147.
Global change and climate‐driven invasion of the Pacific oyster (Crassostrea gigas) along European coasts: a bioenergetics modelling approach
下载免费PDF全文
![点击此处可从《Journal of Biogeography》网站下载免费的PDF全文](/ch/ext_images/free.gif)
148.
ABSTRACT The 1913 volcanic eruption on the island of Ambrym (Vanuatu) struck both groups composing the island’s population at the time, the Islanders and the British Presbyterians who had come to ‘civilise’ them. Through the lens of Peirce’s semiosis, particularly his notion of the ‘indexical sign’, this article examines the chronological development of the two groups’ divergent, and also at times convergent interpretations of the eruption as a sign. This semiotic analysis is then extended into the island’s socio-historical context, from the Presbyterians’ first attempts at missions to the catastrophic upheaval that decimated the island’s population until the 1940s, to study how the two groups interpreted themselves, each other, Western Christianity and the traditional Ambrymese belief and authority system. 相似文献
149.
Yoann Joyard Vadim Le Joncour Hélène Castel Chérif Bounana Diouf Laurent Bischoff Cyril Papamicaël Vincent Levacher Pierre Vera Pierre Bohn 《Bioorganic & medicinal chemistry letters》2013,23(13):3704-3708
Tumor hypoxia plays a major role in reducing the efficacy of therapeutic modalities like chemotherapy and radiation therapy in combating cancer. In order to target hypoxic tissues, a tripeptide ligand having a 2-nitroimidazole moiety, as a bioreductive species, was synthesized. The latter was radiolabeled with 99mTc for imaging hypoxic regions of tumors and was characterized by means of its rhenium analogue. The biodistribution and scintigraphic image of the corresponding 99mTc-complex showed accumulation in tumor and these results suggest that it could be a marker for imaging tumor hypoxia. 相似文献
150.
Chloe Rees-Spear Luke Muir Sarah A. Griffith Judith Heaney Yoann Aldon Jonne L. Snitselaar Peter Thomas Carl Graham Jeffrey Seow Nayung Lee Annachiara Rosa Chloe Roustan Catherine F. Houlihan Rogier W. Sanders Ravindra K. Gupta Peter Cherepanov Hans J. Stauss Eleni Nastouli Laura E. McCoy 《Cell reports》2021,34(12):108890
- Download : Download high-res image (178KB)
- Download : Download full-size image