437 research outputs found

    The promise of enhancer-associated long noncoding RNAs in cardiac regeneration.

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    Heart failure is a worldwide epidemic and represents a major cause of morbidity and mortality. Current clinical therapies for heart disease prolong survival by protecting the viable muscle, but they are unable to replenish lost cardiomyocytes to restore function. Over the last decade, the notion of promoting cardiac regeneration has engendered considerable research interest. New strategies envisage the transfer of stem cells into the damaged myocardium, the mobilization of cardiac precursor cells, the promotion of cardiomyocyte proliferation in situ and direct reprogramming of non-cardiac cells into electromechanically coupled cardiomyocytes. The molecular and cellular mechanisms underpinning these different regenerative avenues are under the control of integrated transcriptional programs, which are ultimately dependent on epigenomic reprogramming and reorganization of the genome nuclear architecture. Today, it is becoming evident that regulatory noncoding RNAs play fundamental roles in all these aspects of gene regulatory network activity. In particular, thousands of long noncoding RNAs are dynamically expressed across the entire genome during lineage-specific commitment, specialization, and differentiation, as well as during the response to environmental cues. Here, we review this emerging landscape, focusing particularly on a unique class of lncRNA emerging from enhancer sequences, the enhancer-associated lncRNAs, in the context of cardiac regeneration. We propose that characterizing and manipulating these enhancer-associated transcripts could provide a novel approach to awaken the dormant regenerative potential of the adult mammalian heart. Ultimately, this could lead to targeted noncoding RNA-based enhancer therapies to improve effectiveness of current regenerative strategies and provide new avenues for repair

    Effect of pressure cycling on Iron: Signatures of an electronic instability and unconventional superconductivity

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    High pressure electrical resistivity and x-ray diffraction experiments have been performed on Fe single crystals. The crystallographic investigation provides direct evidence that in the martensitic bcchcpbcc \rightarrow hcp transition at 14 GPa the {110}bcc\lbrace 110\rbrace_{bcc} become the {002}hcp\lbrace 002\rbrace_{hcp} directions. During a pressure cycle, resistivity shows a broad hysteresis of 6.5 GPa, whereas superconductivity, observed between 13 and 31 GPa, remains unaffected. Upon increasing pressure an electronic instability, probably a quantum critical point, is observed at around 19 GPa and, close to this pressure, the superconducting TcT_{c} and the isothermal resistivity (0<T<3000<T<300\,K) attain maximum values. In the superconducting pressure domain, the exponent n=5/3n = 5/3 of the temperature power law of resistivity and its prefactor, which mimics TcT_{c}, indicate that ferromagnetic fluctuations may provide the glue for the Cooper pairs, yielding unconventional superconductivity

    New Lncs to mesendoderm specification.

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    Mammalian genomes are pervasively transcribed generating thousands of long noncoding RNAs (lncRNAs) with emergent regulatory roles. Many of these lncRNAs exhibit highly specialised expression patterns during development and typically flank and regulate key developmental factors. In this review, we discuss and summarise the latest advances in our understanding of the roles of lncRNAs during mesendoderm (ME) specification, a key step during gastrulation and the formation of the primitive streak (PS)

    Discovery and functional characterization of cardiovascular long noncoding RNAs

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    Recent advances in sequencing and genomic technologies have resulted in the discovery of thousands of previously unannotated long noncoding RNAs (lncRNAs). However, their function in the cardiovascular system remains elusive. Here we review and discuss considerations for cardiovascular lncRNA discovery, annotation and functional characterization. Although we primarily focus on the heart, the proposed pipeline should foster functional and mechanistic exploration of these transcripts in various cardiovascular pathologies. Moreover, these insights could ultimately lead to novel therapeutic approaches targeting lncRNAs for the amelioration of cardiovascular diseases including heart failure

    Exploring high temperature magnetic order in CeTi_1-xSc_xGe

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    Most of magnetic transitions related to Ce ordering are found below T_ord~12K. Among the few cases exceeding that temperature, two types of behaviors can be distinguished. One of them is related to the rare cases of Ce binary compounds formed in BCC structures, with a quartet ground state, whose degeneracy is reduced by undergoing different types of transitions mostly structural. The other group shows evidences of itinerant character with the outstanding example of CeRh_3B_2 showing the highest T_ord=115K. The second highest ordering temperature has been reported for CeScGe with T_ord=47K, but the nature of this magnetic state has not been investigated very deeply. In order to shed more light into this unusual high temperature ordering we studied the structural, magnetic, transport and thermal properties of CeTi_1-xSc_xGe alloys in the stability range of the CeScSi-type structure 0.25<x<1 This system presents a rich variety of magnetic behaviors along this concentration range, with the magnetic ordering growing from ferromagnetic (FM) T_C~7K up to an antiferromagnetic (AFM) transition at T_N=47K. The different regions show the following characteristics: i) on the Ti rich side (0.25<x<0.50) it exhibits a FM ground state (GS) with large saturation magnetization values M_sat up to ~1.15 mu_B. ii) Around x=0.60, the first crystal electric field excited doublet starts to contribute to the GS magnetic properties. Furthermore an AFM component with a connected metamagnetic transition appears. iii) At x=0.65 a clear change in the GS nature is associated to a critical point above which the GS properties can be described like for an itinerant system (with decreasing M_sat) and an effective GS degeneracy N_eff=4. iv) For x>0.65, the magnetic phase boundary splits into two transitions, with an intermediate phase presenting incommensurate spin density waves features.Comment: 8 pages, 10 figure

    On the effect of Ti on Oxidation Behaviour of a Polycrystalline Nickel-based Superalloy

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    Titanium is commonly added to nickel superalloys but has a well-documented detrimental effect on oxidation resistance. The present work constitutes the first atomistic-scale quantitative measurements of grain boundary and bulk compositions in the oxide scale of a current generation polycrystalline nickel superalloy performed through atom probe tomography. Titanium was found to be particularly detrimental to oxide scale growth through grain boundary diffusion
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