Search results for "RATES"
showing 10 items of 1636 documents
Extremely high mutation rate of a hammerhead viroid
2009
Supporting information (Materials and methods, figs. S1-S3, suppl. references) available at: http://www.sciencemag.org/cgi/data/323/5919/1308/DC1/1
SIRT1 prevents genotoxic stress-induced p53 activation in acute myeloid leukemia
2014
SIRT1 is an important regulator of cellular stress response and genomic integrity. Its role in tumorigenesis is controversial. Whereas sirtuin 1 (SIRT1) can act as a tumor suppressor in some solid tumors, increased expression has been demonstrated in many cancers, including hematologic malignancies. In chronic myeloid leukemia, SIRT1 promoted leukemia development, and targeting SIRT1 sensitized chronic myeloid leukemia progenitors to tyrosine kinase inhibitor treatment. In this study, we investigated the role of SIRT1 in acute myeloid leukemia (AML). We show that SIRT1 protein, but not RNA levels, is overexpressed in AML samples harboring activating mutations in signaling pathways. In FMS-l…
Expectations, experiences and attitudes of patients and primary care health professionals regarding online psychotherapeutic interventions for depres…
2013
Abstract Background In the year 2020, depression will cause the second highest amount of disability worldwide. One quarter of the population will suffer from depression symptoms at some point in their lives. Mental health services in Western countries are overburdened. Therefore, cost-effective interventions that do not involve mental health services, such as online psychotherapy programs, have been proposed. These programs demonstrate satisfactory outcomes, but the completion rate for patients is low. Health professionals’ attitudes towards this type of psychotherapy are more negative than the attitudes of depressed patients themselves. The aim of this study is to describe the profile of d…
Inhibition and recovery of symbiotic N2 fixation by peas (Pisum sativum L.) in response to short term nitrate exposure
2014
International audience; Cereal-legume intercrops are a promising way to combine high productivity and several ecological benefits in temperate agro-ecosystems. However the proportion of each species in the mixture at harvest is highly variable. N-fertilisation may be a mean for controlling these proportions (Naudin et al., 2010). Symbiotic N2 fixation (SNF) can be inhibited by nitrate exposure. Although the effect of nitrate on SNF has been extensively investigated different scales, few studies have highlighted the impact of different timings of nitrate exposure on the SNF apparatus (N2 fixation rate and nodule biomass) and on its ability to recover after nitrates removal. The aim of this s…
Sources of nitrous oxide and fate of mineral nitrogen in sub-Arctic permafrost peat soils
2021
Nitrous oxide (N2O) emissions from permafrost-affected terrestrial ecosystems have received little attention, largely because they have been thought to be negligible. Recent studies, however, have shown that there are habitats in subarctic tundra emitting N2O at high rates, such as bare peat surfaces on permafrost peatlands. The processes behind N2O production in these high-emitting habitats are, however, poorly understood. In this study, we established an in situ 15N-labelling experiment with the main objectives to partition the microbial sources of N2O emitted from bare peat surfaces (BP) on permafrost peatlands and to study the fate of ammonium and nitrate in these soils and in adjacent …
β-Aminobutyric Acid Primes an NADPH Oxidase–Dependent Reactive Oxygen Species Production During Grapevine-Triggered Immunity
2010
International audience; The molecular mechanisms underlying the process of priming are poorly understood. In the present study, we investigated the early signaling events triggered by β-aminobutyric acid (BABA), a well-known priming-mediated plant resistance inducer. Our results indicate that, in contrast to oligogalacturonides (OG), BABA does not elicit typical defense-related early signaling events nor defense-gene expression in grapevine. However, in OG-elicited cells pretreated with BABA, production of reactive oxygen species (ROS) and expression of the respiratory-burst oxidase homolog RbohD gene were primed. In response to the causal agent of downy mildew Plasmopara viticola, a strong…
Understanding melt generation beneath the slow-spreading Kolbeinsey Ridge using 238U, 230Th, and 231Pa excesses
2011
International audience; To examine the petrogenesis and sources of basalts from the Kolbeinsey Ridge, one of the shallowest locations along the global ridge system, we present new measurements of Nd, Sr, Hf, and Pb isotopes and U-series disequilibria on 32 axial basalts. Young Kolbeinsey basalts (full-spreading rate = 1.8 cm/yr; 67 degrees 05'-70 degrees 26'N) display ((230)Th/(238)U) 1 with ((230)Th/(238)U) from 0.95 to 1.30 and have low U (11.3-65.6 ppb) and Th (33.0 ppb-2.40 ppm) concentrations. Except for characteristic isotopic enrichment near the Jan Mayen region, the otherwise depleted Kolbeinsey basalts (e. g. (87)Sr/(86)Sr = 0.70272-0.70301, epsilon(Nd) = 8.4-10.5, epsilon(Hf) = 15…
Unraveling the interaction between doxorubicin and DNA origami nanostructures for customizable chemotherapeutic drug release
2020
Doxorubicin (DOX) is a commonly employed drug in cancer chemotherapy, and its high DNA-binding affinity can be harnessed in preparing programmable DOX-loaded DNA nanostructures that can be further tailored for targeted delivery and therapeutics. Although DOX has been widely studied, the existing literature of promising DOX-loaded DNA nanocarriers remains limited and incoherent. A number of reports have over-looked the fundamentals of the DOX-DNA interaction, let alone the peculiarities arising from the complexity of the system as a whole. Here, based on an in-depth spectroscopic analysis, we characterize and optimize the DOX loading into different 2D and 3D scaffolded DNA origami nanostruct…
Growth of low-density vertical quantum dot molecules with control in energy emission
2010
This article is distributed under the terms of the Creative Commons Attribution Noncommercial License.-- This article is part of the series 8th International Workshop on Epitaxial Semiconductors on Patterned Substrates and Novel Index Surfaces.
Selective mono-de-O-acetylation of the per-O-acetylated brasilicardin carbohydrate side chain
2021
Abstract Methanol dried over powdered 4 A molecular sieves can be used for a selective mono-de-O-acetylation of the phenolic acetyl group of the per-O-acetyl protected brasilicardin A carbohydrate side chain. This reaction opens a practical procedure for a synthetic access to derivates of the immunosuppressive and cytotoxic natural product brasilicardin A.