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201.
Ole J Hamming Ewa Terczyńska‐Dyla Gabrielle Vieyres Ronald Dijkman Sanne E Jørgensen Hashaam Akhtar Piotr Siupka Thomas Pietschmann Volker Thiel Rune Hartmann 《The EMBO journal》2013,32(23):3055-3065
The IFNL4 gene is a recently discovered type III interferon, which in a significant fraction of the human population harbours a frameshift mutation abolishing the IFNλ4 ORF. The expression of IFNλ4 is correlated with both poor spontaneous clearance of hepatitis C virus (HCV) and poor response to treatment with type I interferon. Here, we show that the IFNL4 gene encodes an active type III interferon, named IFNλ4, which signals through the IFNλR1 and IL‐10R2 receptor chains. Recombinant IFNλ4 is antiviral against both HCV and coronaviruses at levels comparable to IFNλ3. However, the secretion of IFNλ4 is impaired compared to that of IFNλ3, and this impairment is not due to a weak signal peptide, which was previously believed. We found that IFNλ4 gets N‐linked glycosylated and that this glycosylation is required for secretion. Nevertheless, this glycosylation is not required for activity. Together, these findings result in the paradox that IFNλ4 is strongly antiviral but a disadvantage during HCV infection. 相似文献
202.
Markus W. Germann Bernd W. Kalisch Johan H. van de Sande 《Journal of biomolecular structure & dynamics》2013,31(6):953-962
Abstract Oligodeoxyribonucleotides containing dA·dU base combinations were shown to form parallel stranded DNA. CD spectra and hyperchromicity profiles provide evidence that the structure is very similar to that of a related parallel stranded dA·oligomer. Thermal denaturation studies show that these parallel dAdU sequences are significantly less stable than their dA·analogues in either antiparallel or parallel stranded orientations. The stabilizing effect of the 5- methyl group is similar for parallel and antiparallel sequences. The minor groove binding drug Hoechst 33258 binds with similar affinity to APS dA·and APS dA·dU sequences. However, binding to the PS dA·hairpin is significantly impaired as a consequence of the different groove dimensions and the presence of thymine methyl groups at the binding site. This results in an 8.6 kJmoF reduced free energy of binding for the PS dA·sequence. Replacement of the bulky methyl group with a hydrogen (ie. T -> U) results in significantly stronger Hoechst 33258 binding to the parallel dA·dU sequences with a penalty of only 4.1 kJmol?1. Our data demonstrate that although Hoechst 33258 detects the altered groove, it is still able to bind a PS duplex containing dA·dU base pairs with high affinity, despite the large structural differences from its regular binding site in APS DNA. 相似文献
203.
204.
In order to analyze whether impairments to health and well‐being under flexible working hours can be predicted from specific characteristics of the work schedules, periodic components in flexible working hours and their interference with the circadian temperature rhythm were analyzed applying univariate and bivariate spectrum analyses to both time series. The resulting indicators of spectral power and phase shift of these components were then related to reported health impairments using regression analysis. The results show that a suppression of both the 24 and the 168 h components in the work schedules (i.e., a lack of periodicity) can be used to predict reported health impairments, and that if there are relatively strong 24 and 168 h components left in the work schedules, their phase difference with the temperature rhythm (as an indicator of the interference between working time and the circadian rhythm) further predicts impairment. The results indicate that the periodicity of working hours and the amount of (circadian) desynchronization induced by flexible work schedules can be used for predicting the impairing effects of flexible work schedules on health and well‐being. The results can thus be used for evaluating and designing flexible shift rosters. 相似文献
205.
It is well known that proprioception is composed of the senses of movement and position. Whereas tests of position sense are quite commonly used, tests of the acuity in perception of movement velocity are scarce. In the present study we examined some novel tests for assessing the sense of limb movement velocity, involving replication and discrimination of single-joint movement velocity. Specifically, we investigated: (1) whether replication of limb movement velocity is more accurate following active criterion movements as compared to passive; (2) whether antagonist muscle contraction during passive limb movement enhances velocity discrimination; (3) how criterion movement velocity influences response accuracy; (4) the relationship between movement velocity and movement extent during velocity replication; and (5) whether subjects really base discrimination of velocities on perceived velocity. Sixteen healthy subjects participated in four tests (I-IV). For each test, horizontal abductions were performed about the right glenohumeral joint from the sagittal plane. The subjects were required to actively replicate the velocity of either an active (Test I) or passive (Test II) criterion movement, or judge whether a passive/semipassive (passive during antagonist muscle contraction) movement was faster or slower than a previous passive/semipassive criterion movement (Test III/IV). The results revealed higher response accuracy for Test I compared to Test II and for slower movements compared to faster, but no difference in response accuracy between Test III and IV. For velocity discrimination, the analysis revealed that the subjects based their judgment on the difference between criterion and comparison velocity rather than time or extent cues. 相似文献
206.
María Victoria Albarracín Johan Six Benjamin Z. Houlton Caroline S. Bledsoe 《Oecologia》2013,173(4):1439-1450
Ectomycorrhizal (EM) fungi form relationships with higher plants; plants transfer C to fungi, and fungi transfer nutrients to their host. While evidence indicates that this interaction is largely mutualistic, less is known about how nutrient supply and EM associates may alter C and nutrient exchanges, especially in intact plant-soil-microbe systems in the field. In a dual-labeling experiment with N fertilization, we used C and N stable isotopes to examine in situ transfers in EM pine trees in a Pinus sabiniana woodland in northern California. We added 15NH4SO2 and 13CO2 to track 13C transfer from pine needles to EM roots and 15N transfer from soil to EM roots and pine needles. Transfers of 13C and 15N differed with EM morphotype and with N fertilization. The brown morphotype received the least C per unit of N transferred (5:1); in contrast red and gold morphotypes gained more C and transferred less N (17:1 and 25:1, respectively). N fertilization increased N retention by ectomycorrhizas (EMs) but did not increase N transfer from EMs to pine needles. Therefore N fertilization positively affected both nutrient and C gains by EMs, increasing net C flows and N retention in EMs. Our work on intact and native trees/EM associations thereby extends earlier conclusions based on pot studies with young plants and culturable EM fungi; our results support the concept that EM-host relationships depend on species-level differences as well as responses to soil resources such as N. 相似文献
207.
Jim Rasmussen Gedrime Kusliene Ole Stig Jacobsen Yakov Kuzyakov Jørgen Eriksen 《Plant and Soil》2013,371(1-2):191-198
Aims
Application of carbon (C) and nitrogen (N) isotopes is an essential tool to study C and N flows in plant-soil-microorganisms systems. When targeting single plants in a community the tracers need to be added via e.g., leaf-labeling or stem-feeding approaches. In this study we: (i) investigated if bicarbonate can be used to introduce 14C (or 13C) into white clover and ryegrass, and (ii) compared the patterns of 14C and 15N allocation in white clover and ryegrass to evaluate the homogeneity of tracer distribution after two alternative labeling approaches.Methods
Perennial ryegrass and white clover were pulse labeled with 15N urea via leaf-labeling and 14C either via a 14CO2 atm or with 14C bicarbonate through leaf-labeling. Plants were sampled 4 days after labeling and prepared for bulk isotope analysis and for 14C imaging to identify plant parts with high and low 14C activity. Subsequently, plant parts with high and low 14C activity were separated and analyzed for 15N enrichment.Results
Bicarbonate applied by leaf-labeling efficiently introduced 14C into both white clover and ryegrass, although the 14C activity in particular for white clover was found predominantly in the labeled leaf. Using 14C imaging for identification of areas with high (hotspots) and low 14C activity showed that 14C was incorporated very heterogeneously both when using bicarbonate and CO2 as expected when using pulse labeling. Subsequent analysis of 15N enrichment in plant parts with high and low 14C activity showed that 15N also had a heterogeneous distribution (up to two orders of magnitude).Conclusion
Bicarbonate can efficiently be used to introduce 14C or 13C into plant via the leaf-labeling method. Both 14C and 15N showed heterogeneous distribution in the plant, although the distribution of 15N was more even than that of 14C. 相似文献208.
The nominal family group taxa of the Ephemeroptera are listed along with their authors, dates of publication and bibliographic references. 相似文献
209.
Ping‐Pin Zheng Marcel van der Weiden Peter J. van der Spek Arnaud J.P.E. Vincent Johan M. Kros 《Journal of cellular physiology》2013,228(7):1383-1390
Literature data indicate that glioma stem cells may give rise to both tumor cells and endothelial progenitor cells (EPCs). Malignant glioma patients usually have increased levels of circulating (EPCs) and these cells are known to contribute to the glioma neovasculature. In this study we compared the intratumoral and circulating EPCs of glioma patients for a set of common glioma genotypical aberrations (amplification of EGFR; deletion of PTEN and aneusomy of chromosomes 7 and 10). We found that the EPCs present in the tumor tissues, not the circulating EPCs, share genetic aberrations with the tumor cells. EPCs with EGFR amplification were found in 46% and with PTEN deletion in 36% of the cases. EPCs with polysomy 7 and monosomy 10 were detected in 56% and 38% of the cases while centrosomal abnormalities in EPCs were found in 68% of the cases. The presence of genetic aberrations of glioma cells in intratumoral EPCs may point to transdifferentiation of glioma stem cells into EPCs. However, the tissue specific CD133 splice variant of blood EPCs was detected in the glioma tissues but not in control brains, suggestive of a blood origin of at least part of the intratumoral EPCs. The findings highlight the complexity of the cellular constituents of glioma neovascularization which should be taken into account when developing anti‐angiogenic strategies for gliomas. J. Cell. Physiol. 228: 1383–1390, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
210.