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201.
Jesper Wengel Michael Petersen Miriam Frieden Troels Koch 《Letters in Peptide Science》2003,10(3-4):237-253
Preparation of LNA nucleosides requires a number of synthetic steps but very efficient procedures have been developed, as
have protocols for synthesis of LNA oligonucleotides on automated DNA synthesizers. In all cases, LNA oligonucleotides have
exhibited good aqueous solubility as would be expected from their close structural resemblance to the natural nucleic acids.
The universality of LNA mediated high-affinity and specific hybridization has been demonstrated extensively with a large number
of duplex forming LNA-oligonucleotides. Most importantly, most of the members of the LNA molecular family have been shown
to exert their substantial affinity increase (i) in combination with standard DNA, RNA and contemporary analogues and (ii)
whether inserted as single nucleosides in an oligonucleotide or as blocks of contiguous nucleotides, an important point. The
works on TFO's is expanding the usefulness of LNA to double strand recognition and it has been demonstrated that LNA it is
a promising structure for further base modifications in the pursuit of global sequence specific recognition of DNA. 相似文献
202.
Jesper Givskov Sørensen Minna Pekkonen Beatrice Lindgren Volker Loeschcke Anssi Laurila Juha Merilä 《Journal of thermal biology》2009
- 1.
- We tested for geographical variation in heat tolerance and Hsp70 expression levels of Rana temporaria tadpoles along a 1500 km long latitudinal gradient in Sweden. 相似文献
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204.
Koji Nagahama Rakesh N. Veedu Jesper Wengel 《Bioorganic & medicinal chemistry letters》2009,19(10):2707-2709
Synthesis of chimeric 9-mer oligonucleotides containing methylphosphonate-linkages and locked nucleic acid (LNA) monomers, their binding affinity towards complementary DNA and RNA, and their 3′-exonucleolytic stability are described. The obtained methylphosphonate-DNA/LNA chimeric oligonucleotides display similarly high RNA affinity and RNA selectivity as a corresponding 9-mer DNA/LNA chimeric oligonucleotide, but much higher resistance towards 3′-exonucleolytic degradation. 相似文献
205.
Christina Krabbe† Elise Courtois‡ Pia Jensen Jesper R. Jørgensen† Jens Zimmer Alberto Martínez-Serrano‡ Morten Meyer 《Journal of neurochemistry》2009,110(6):1908-1920
Neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. Here we investigated the effect of the anti-apoptotic protein Bcl-xL and oxygen tension on dopaminergic differentiation and survival of a human ventral mesencephalic stem cell line (hVM1). hVM1 cells and a Bcl-xL over-expressing subline (hVMbcl-xL ) were differentiated by sequential treatment with fibroblast growth factor-8, forskolin, sonic hedgehog, and glial cell line-derived neurotrophic factor. After 10 days at 20% oxygen, hVMbcl-xL cultures contained proportionally more tyrosine hydroxylase(TH)-positive cells than hVM1 control cultures. This difference was significantly potentiated from 11 ± 0.8% to 17.2 ± 0.2% of total cells when the oxygen tension was lowered to 3%. Immunocytochemistry and Q-PCR-analysis revealed expression of several dopaminergic markers besides of TH just as dopamine was detected in the culture medium by HPLC analysis. Although Bcl-xL -over-expression reduced cell death in the cultures, it did not alter the relative content of GABAergic, neurons, while the content of astroglial cells was reduced in hVMbcl-xL cell cultures compared with control. We conclude that Bcl-xL and lowered oxygen tension act in concert to enhance dopaminergic differentiation and survival of human neural stem cells. 相似文献
206.
Pedro Cardoso Sérgio S. Henriques Clara Gaspar Luis C. Crespo Rui Carvalho Jesper B. Schmidt Pedro Sousa Tamás Szűts 《Journal of Insect Conservation》2009,13(1):45-55
Intensive fieldwork has been undertaken in Portugal in order to develop a standardized and optimized sampling protocol for
Mediterranean spiders. The present study had the objectives of testing the use of semi-quantitative sampling for obtaining
an exhaustive species richness assessment of spiders and testing the effects of day, time of day, collector and sampling method
on the collected species richness and composition of a Mediterranean scrubland. The collecting summed 224 samples corresponding
to one person-hour of effective fieldwork each. In total, 115 species were captured, of which 110 were recorded inside a delimited
one-hectare plot, corresponding to more than 70% of the about 160 estimated species. Although no estimator reached the asymptote,
the Michaelis-Menten curve behaviour indicates that the estimated richness should be accurate. Most different sampling approaches
(day, time of day, collector and sampling method) were found to influence richness, abundance or composition of the samples
to some extent, although sampling method had the strongest influence whereas “collector” showed no effect at all. The results
support the idea that the only variables that need to be controlled in similar protocols are the sampling methods and the
time of day when each method is executed. We conclude that populations in structurally simple habitats present narrower peaks
of adult abundance, which implies higher percentages of juveniles in samples. Finally, results also indicate that habitats
with a relatively simple structure like scrublands may require as much sampling effort, in order to reach similar proportions
of captured species in relation to the estimated richness, as habitats that are much more complex. 相似文献
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209.
Background
Molecular signatures are sets of genes, proteins, genetic variants or other variables that can be used as markers for a particular phenotype. Reliable signature discovery methods could yield valuable insight into cell biology and mechanisms of human disease. However, it is currently not clear how to control error rates such as the false discovery rate (FDR) in signature discovery. Moreover, signatures for cancer gene expression have been shown to be unstable, that is, difficult to replicate in independent studies, casting doubts on their reliability. 相似文献210.