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排序方式: 共有219条查询结果,搜索用时 140 毫秒
11.
Peng Zhang Trine Nygaard Jørgensen Claus J. Loland Amy Hauck Newman 《Bioorganic & medicinal chemistry letters》2013,23(1):323-326
A novel fluorescent ligand was synthesized as a high-affinity, high specificity probe for visualizing the serotonin transporter (SERT). The rhodamine fluorophore was extended from an aniline substitution on the 5-position of the dihydroisobenzofuran ring of citalopram (2, 1-(3-(dimethylamino)propyl)-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile), using an ethylamino linker. The resulting rhodamine-labeled ligand 8 inhibited [3H]5-HT uptake in COS-7 cells (Ki = 225 nM) with similar potency to the tropane-based JHC 1-064 (1), but with higher specificity towards the SERT relative to the transporters for dopamine and norepinephrine. Visualization of the SERT with compound 8 was demonstrated by confocal microscopy in HEK293 cells stably expressing EGFP–SERT. 相似文献
12.
Camilla Ru Rasmussen Anne Nygaard Weisbach Kristian Thorup-Kristensen Jacob Weiner 《Journal of Plant Ecology》2019,12(1):78
Aims
There is much evidence that plant competition below ground is size symmetric, i.e. that competing plants share contested resources in proportion to their sizes. Several researchers have hypothesized that a patchy distribution of soil nutrients could result in size-asymmetric root competition. We tested this hypothesis. 相似文献
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G. Nygaard 《International Review of Hydrobiology》1989,74(3):293-319
Photosynthetically active radiation (PAR) was registered daily in 0.25 m and 11.25 m in 3 years. Upwards irradiance of green light was 1 % of downward irradiance. Incubator 14C experiments showed that the phytoplankton enhanced its carbon uptake substantially with increasing concentrations of the carrier CO2 in the ampoules. Severe carbon limitation of photosynthesis occurred in spring and summer 1961, where the real carbon fixation was only about 34 % of that calculated by the usual procedure. Utilization of light and DIC by the phytoplankton and its compensation depth was determined. Photoinhibition occurred down to 10–11 m, and net primary production was nearly always positive in any depth down to the lake bottom. 相似文献
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Travis BR Christensen TD Smerup M Olsen MS Hasenkam JM Nygaard H 《Journal of biomechanical engineering》2004,126(1):26-35
This work introduces a method for the in vivo measurement and analysis of turbulence within the leakage of a mechanical heart valve. Several analysis techniques were applied to ultrasound measurements acquired within the atrium of a pig, and error associated with these techniques was analyzed. The technique chosen applies cyclic averaging to mean and maximum velocity measurements within small, normalized phase windows to calculate Reynolds normal stresses in the direction of the ultrasound beam. Maximum shear stresses are estimated from these normal stresses using an analytical technique. The stresses observed were smaller than those reported from previous in vitro simulations. 相似文献
18.
Nielsen SL Nygaard H Mandrup L Fontaine AA Hasenkam JM He S Yoganathan AP 《Journal of biomechanical engineering》2002,124(5):596-608
Clinically observed incomplete mitral leaflet coaptation was reproduced in vitro by altering the balance of the chordal tethering and chordal coapting force components. Mitral leaflet coaptation geometry was distorted by changes of the spatial relations between the papillary muscles and the mitral valve as well as hemodynamics. Mitral leaflet malalignment was accentuated by a redistribution of the chordal tethering and coapting force components. For the overall assessment of systolic mitral leaflet configuration in functional mitral regurgitation it is important to consider the interaction between chordal restraint and an altered mitral leaflet coaptation geometry. 相似文献
19.
Haslekås C Viken MK Grini PE Nygaard V Nordgard SH Meza TJ Aalen RB 《Plant physiology》2003,133(3):1148-1157
Peroxiredoxins (Prx) are thiol-dependent antioxidants containing one (1-cysteine [-Cys]) or two (2-Cys) conserved Cys residues that protect lipids, enzymes, and DNA against reactive oxygen species. In plants, the 1-Cys Prxs are highly expressed during late seed development, and the expression pattern is dormancy related in mature seeds. We have expressed the Arabidopsis 1-Cys Prx AtPER1 in Escherichia coli and show that this protein has antioxidant activity in vitro and protects E. coli in vivo against the toxic oxidant cumene hydroperoxide. Although some 1-Cys Prxs are targeted to the nucleus, a green fluorescent protein-AtPER1 fusion protein was also localized to the cytoplasm in an onion epidermis subcellular localization assay. It has been proposed that seed Prxs are involved in maintenance of dormancy and/or protect the embryo and aleurone layer surviving desiccation against damage caused by reactive oxygen species. These hypotheses were tested using transgenic Arabidopsis lines overexpressing the barley (Hordeum vulgare) 1-Cys PER1 protein and lines with reduced levels of AtPER1 due to antisensing or RNA interference. We found no correlation between Prx levels and the duration of the after-ripening period required before germination. Thus, Prxs are unlikely to contribute to maintenance of dormancy. RNA interference lines almost devoid of AtPER1 protein developed and germinated normally under standard growth room conditions. However, seeds from lines overexpressing PER1 were less inclined to germinate than wild-type seeds in the presence of NaCl, mannitol, and methyl viologen, suggesting that Prx can sense harsh environmental surroundings and play a part in the inhibition of germination under unfavorable conditions. 相似文献
20.
Johansen P Manning KB Tarbell JM Fontaine AA Deutsch S Nygaard H 《Journal of biomechanical engineering》2003,125(5):663-670
Evaluation of cavitation in vivo is often based on recordings of high-pass filtered random high-frequency pressure fluctuations. We hypothesized that cavitation signal components are more appropriately assessed by a new method for extraction of random signal components of the pressure signals. We investigated three different valve types and found a high correlation between the two methods (r2: 0.8806-0.9887). The new method showed that the cavitation signal could be extracted without a priori knowledge needed for setting the high-pass filter cut off frequency, nor did it introduce bandwidth limitation of the cavitation signal. 相似文献