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排序方式: 共有393条查询结果,搜索用时 46 毫秒
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Elias Broman Caroline Raymond Christian Sommer Jonas S. Gunnarsson Simon Creer Francisco J. A. Nascimento 《Molecular ecology》2019,28(16):3813-3829
Coastal benthic biodiversity is under increased pressure from climate change, eutrophication, hypoxia, and changes in salinity due to increase in river runoff. The Baltic Sea is a large brackish system characterized by steep environmental gradients that experiences all of the mentioned stressors. As such it provides an ideal model system for studying the impact of on‐going and future climate change on biodiversity and function of benthic ecosystems. Meiofauna (animals < 1 mm) are abundant in sediment and are still largely unexplored even though they are known to regulate organic matter degradation and nutrient cycling. In this study, benthic meiofaunal community structure was analysed along a salinity gradient in the Baltic Sea proper using high‐throughput sequencing. Our results demonstrate that areas with higher salinity have a higher biodiversity, and salinity is probably the main driver influencing meiofauna diversity and community composition. Furthermore, in the more diverse and saline environments a larger amount of nematode genera classified as predators prevailed, and meiofauna‐macrofauna associations were more prominent. These findings show that in the Baltic Sea, a decrease in salinity resulting from accelerated climate change will probably lead to decreased benthic biodiversity, and cause profound changes in benthic communities, with potential consequences for ecosystem stability, functions and services. 相似文献
84.
Schuler-Faccini L Soares RC de Sousa AC Maximino C Luna E Schwartz IV Waldman C Castilla EE 《Birth defects research. Part A, Clinical and molecular teratology》2007,79(9):671-672
Thalidomide is the best known human teratogen. Although withdrawn from the market in 1961, thalidomide was remarketed after 1965 in several countries, for the treatment of erythema nodosum leprosum. Thalidomide has a potent immunomodulatory property and has now a number of approved and off-label uses in dermatologic, oncologic, infectious and gastrointestinal conditions. In the U.S., FDA approved the use of thalidomide in 1998, but no cases of thalidomide embriophaty were registered after that. Since 1996 no new cases were reported in Latin America. However, the Teratogen Information Service (TIS) Porto Alegre, recorded three new cases of thalidomide embriophaty born in Brazil since 2005. Considering that these three cases were not registered through a systematic surveillance system, but that came to our attention through a series of coincidental random events, it can be assumed that the actual occurrence of affected babies by thalidomide continues being as frequent as denounced ten years ago. 相似文献
85.
2'-o-dimethylaminoethoxyuridine and 5-dimethylaminopropargyl deoxyuridine for at base pair recognition in triple helices 总被引:1,自引:0,他引:1
Brennan L Peng G Srinivasan N Fox KR Brown T 《Nucleosides, nucleotides & nucleic acids》2007,26(10-12):1283-1286
The nucleoside analogues 2'-O-dimethylaminoethoxy uridine and 5-dimethylaminopropargyl deoxyuridine have been synthesised and incorporated into oligonucleotides. Their triplex-stabilising properties have been determined in fluorescence melting experiments. 相似文献
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Ecophysiological adjustment of two Sphagnum species in response to anthropogenic nitrogen deposition
Here, it was investigated whether Sphagnum species have adjusted their nitrogen (N) uptake in response to the anthropogenic N deposition that has drastically altered N-limited ecosystems, including peatlands, worldwide. A lawn species, Sphagnum balticum, and a hummock species, Sphagnum fuscum, were collected from three peatlands along a gradient of N deposition (2, 8 and 12 kg N ha(-1) yr(-1)). The mosses were subjected to solutions containing a mixture of four N forms. In each solution one of these N forms was labeled with (15)N (namely (15)NH(+)(4), (15)NO(-)(3) and the amino acids [(15)N]alanine (Ala) and [(15)N]glutamic acid (Glu)). It was found that for both species most of the N taken up was from , followed by Ala, Glu, and very small amounts from NO(-)(3). At the highest N deposition site N uptake was reduced, but this did not prevent N accumulation as free amino acids in the Sphagnum tissues. The reduced N uptake may have been genetically selected for under the relatively short period with elevated N exposure from anthropogenic sources, or may have been the result of plasticity in the Sphagnum physiological response. The negligible Sphagnum NO(-)(3) uptake may make any NO(-)(3) deposited readily available to co-occurring vascular plants. 相似文献
88.
Kinetic and thermodynamic characterization of single-mismatch discrimination using single-molecule imaging 下载免费PDF全文
Anders Gunnarsson Peter Jnsson Vladimir P. Zhdanov Fredrik Hk 《Nucleic acids research》2009,37(14):e99
A single-molecule detection setup based on total internal reflection fluorescence (TIRF) microscopy has been used to investigate association and dissociation kinetics of unlabeled 30mer DNA strands. Single-molecule sensitivity was accomplished by letting unlabeled DNA target strands mediate the binding of DNA-modified and fluorescently labeled liposomes to a DNA-modified surface. The liposomes, acting as signal enhancer elements, enabled the number of binding events as well as the residence time for high affinity binders (Kd < 1 nM, koff < 0.01 s−1) to be collected under equilibrium conditions at low pM concentrations. The mismatch discrimination obtained from the residence time data was shown to be concentration and temperature independent in intervals of 1–100 pM and 23–46°C, respectively. This suggests the method as a robust means for detection of point mutations at low target concentrations in, for example, single nucleotide polymorphism (SNP) analysis. 相似文献
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Manuela Basso Giuseppina Samengo Giovanni Nardo Tania Massignan Giuseppina D'Alessandro Silvia Tartari Lavinia Cantoni Marianna Marino Cristina Cheroni Silvia De Biasi Maria Teresa Giordana Michael J. Strong Alvaro G. Estevez Mario Salmona Caterina Bendotti Valentina Bonetto 《PloS one》2009,4(12)