18 research outputs found

    Molecular and cellular pathophysiology of circulating cardiomyocyte-specific cell free DNA (cfDNA): Biomarkers of heart failure and potential therapeutic targets

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    Pathological cardiac damage during heart failure is associated with cell death and damage associated molecular patterns (DAMPs) release which triggers a viscous cycle of sterile inflammation to mediate maladaptive cardiac tissue remodelling during the progression to heart failure. DAMPs like cytokines, chemokines, and nuclear or mitochondrial genomic fragments are released in the pathological myocardium. Interestingly, circulating or cytosolic DNA fragments can play a role in the disease by interaction with nucleic acid sensors expressed in cardiomyocyte and non-myocyte neighbouring cells. The circulating cell free DNA (cfDNA) fragments have been clinically reported as markers for various diseases including cardiovascular pathophysiology. Such cfDNA within the DAMP pool can mediate intra- and inter-cellular signalling cascade to upregulate transcriptional expression of inflammatory mediators and trigger oxidative stress within cells. The cellular role of such genomic equivalents varying with chronic or acute stress might be correlated with the cell death forms encountered in myocardium during disease progression. Thus, cfDNA can be phenotypically correlated as a critical player towards upregulation of pathological processes like interstitial fibrosis, cardiomyocyte contractile dysfunction and cell death. Herein, we review the association of cfDNA with heart failure and analyse their potential usage as novel and effective therapeutic targets towards augmentation of cardiac function

    Kinetically stabilized C-60-toluene solvate nanostructures with a discrete absorption edge enabling supramolecular topotactic molecular exchange

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    Nanosized fullerene solvates have attracted widespread research attention due to recent interesting discoveries. A particular type of solvate is limited to a fixed number of solvents and designing new solvates within the same family is a fundamental challenge. Here we demonstrate that the hexagonal closed packed (HCP) phase of C-60 solvates, formed with m-xylene, can also be stabilized using toluene. Contrary to the notion on their instability, these can be stabilized from minutes up to months by tuning the occupancy of solvent molecules. Due to high stability, we could record their absorption edge, and measure excitonic life-time, which has not been reported for any C-60 solvate. Despite being solid, absorbance spectrum of the solvates is similar in appearance to that of C-60 in solution. A new absorption band appears at 673 nm. The fluorescence lifetime at 760 nm is similar to 1.2 ns, suggesting an excited state unaffected by solvent-C-60 interaction. Finally, we utilized the unstable set of HCP solvates to exchange with a second solvent by a topotactic exchange mechanism, which rendered near permanent stability to the otherwise few minutes stable solvates. This is also the first example of topotactic exchange in supramolecular crystal, which is widely known in ionic solids. (C) 2014 Elsevier Ltd. All rights reserved

    Photoelectrocatalytic detection of NADH on n-type silicon semiconductors facilitated by carbon nanotube fibers

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    [EN] NADH is a key biomolecule involved in many biocatalytic processes as cofactor and its quantification can be correlated to specific enzymatic activity. Many effort s have been t aken to obt ain clean electrochemical signals related to NADH presence and lower its redox overpotential to avoid interferences. Suppression of background and secondary signals can be achieved by including a switchable electroactive surface, for instance, by using semiconductors able to harvest light energy and drive the excited electrons only when irradiated. Here we present the combination of a n-type Si semiconductor with fibers made of carbon nanotubes as electroactive surface for NADH quantification at low potentials only upon irradiation. The resulting photoelectrode responded linearly to NADH concentrations from 50 μM to 1.6 mM with high sensitivity (54 μA cm −2 mM −1 ). This system may serve as a biosensing platform for detection and quantification of dehydrogenases’ activity.European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 713366 . A.D.L., M.R and J.J.V. thank the ”Comunidad de Madrid ”for its support to the FotoArt-CM project ( S2018/NMT-4367 ) through the Program of R&D activities between research groups in Technologies 2018, co- financed by European Structural Funds. J.J.V. is grateful for generous financial support provided by the European Union Horizon 2020 Program under grant agreement 678565 (ERC-STEM) and by the MINECO ( RyC-2014-15115 HYNANOSC RTI2018-099504-A-C22Peer reviewe

    Investigating the Influence of the Effective Ionic Transport on the Electrochemical Performance of Si/C-Argyrodite Solid‐State Composites

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    Solid-state batteries have the potential to outperform conventional lithium-ion batteries, as they offer higher energy densities, necessary for the increasing demand for portable energy storage. Silicon-graphite composites are considered to be one of the most promising alternatives to the lithium metal anode due to their low lithiation potential and resistance against dendrite formation. Since these composites show insufficient ionic conductivity, a fast-conducting solid electrolyte is needed to facilitate the charge carrier transport. Optimizing the volume fractions of the solid electrolyte is crucial to ensure sufficient charge carrier transport and achieve the optimal performance. In this work, the influence of the charge carrier transport in a silicon on graphite (Si/C)/argyrodite solid electrolyte composite on the electrochemical performance is studied. By systematically varying the ratio of the Si/C to solid electrolyte, it was found that the effective ionic conductivity of the electrode composite improves exponentially with increasing content of the solid electrolyte, which in turn leads to an increase in the specific capacity of the composite across all C-rates. This study highlights the importance of understanding and customizing charge carrier transport properties in solid-state anode composites to achieve optimum electrochemical performance

    Transparent and flexible high-power supercapacitors based on carbon nanotube fibre aerogels

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    In this work, we report on the fabrication of continuous transparent and flexible supercapacitors by depositing a CNT network onto a polymer electrolyte membrane directly from an aerogel of ultra-long CNTs produced floating in the gas phase. The supercapacitors combine record power density of 1370kWkg11370 kW kg^{-1} at high transmittance (ca.70ca. 70%), high electrochemical stability during extended cycling (>94>94% capacitance retention over 20000cycles20 000 cycles) as well as against repeated 180deg180{\deg} flexural deformation. They represent a significant enhancement of 1-3 orders of magnitude compared to the prior-art transparent supercapacitors based on graphene, CNTs, and rGO. These features mainly arise from the exceptionally long length of the CNTs, which makes the material behave as a bulk conductor instead of an aspect ratio-limited percolating network, even for electrodes with >90>90% transparency. The electrical and capacitive figures-of-merit for the transparent conductor are FoMe=2.7FoMe = 2.7, and FoMc=0.46FS1cm2FoMc = 0.46 F S^{-1} cm^{-2} respectivel

    Self-immobilized Pd nanowires as an excellent platform for a continuous flow reactor: efficiency, stability and regeneration

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    Despite extensive use of Pd nanocrystals as catalysts, the realization of a Pd-based continuous flow reactor remains a challenge. Difficulties arise due to ill-defined anchoring of the nanocrystals on a substrate and reactivity of the substrate under different reaction conditions. We demonstrate the first metal (Pd) nanowire-based catalytic flow reactor that can be used across different filtration platforms, wherein, reactants flow through a porous network of nanowires (10–1000 nm pore sizes) and the product can be collected as filtrate. Controlling the growth parameters and obtaining high aspect ratio of the nanowires (diameter = ∼13 nm and length > 8000 nm) is necessary for successful fabrication of this flow reactor. The reactor performance is similar to a conventional reactor, but without requiring energy-expensive mechanical stirring. Synchrotron-based EXAFS studies were used to examine the catalyst microstructure and Operando FT-IR spectroscopic studies were used to devise a regenerative strategy. We show that after prolonged use, the catalyst performance can be regenerated up to 99% by a simple wash-off process without disturbing the catalyst bed. Thus, collection, regeneration and redispersion processes of the catalyst in conventional industrial reactors can be avoided. Another important advantage is avoiding specific catalyst-anchoring substrates, which are not only expensive, but also non-universal in nature

    Toward Achieving High Areal Capacity in Silicon-Based Solid-State Battery Anodes: What Influences the Rate-Performance?

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    Achieving high areal capacity and rate performance in solid-state battery electrodes is challenging due to sluggish charge carrier transport through thick all-solid composite electrodes, as the transport strongly relies on the microstructure and porosity of the compressed composite. Introducing a high-capacity material like silicon for such a purpose would require fast ionic and electronic transport throughout the electrode. In this work, by designing a composite electrode containing Si nanoparticles, a superionic solid electrolyte (SE), and a carbon additive, the possibility of achieving areal capacities over 10 mAh·cm–2 and 4 mAh·cm–2 at current densities of 1.6 mA·cm–2 and 8 mA·cm–2, respectively, at room temperature is demonstrated. Using DC polarization measurements, impedance spectroscopy, microscopic analyses, and microstructure modeling, we establish that the route to achieve high-performance anode composites is microstructure modulation through attaining high silicon/solid electrolyte interface contacts, particle size compatibility of the composite components, and their well-distributed compact packing in the compressed electrode

    Quality Changes of Common Edible Frying Oils during Frying of Traditional Foods

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    This study aimed to examine the impact of the frying process on the physical and chemical properties of widely consumed edible oils. Soybean, palm, and mustard oils, as well as raw dulpuri and singara products, were procured from the nearby marketplace. The oils underwent five consecutive frying cycles at temperatures exceeding 160°C and were subjected to five hours of heating. Analyses including determination of free fatty acid (FFA), peroxide value (PV), saponification value (SV), iodine value (IV), and optical density (OD) at a wavelength of 425 nm were performed. Following multiple rounds of frying and heating, the levels of FFA, PV, and oxidative stability index exhibited an increase, whereas the IV demonstrated a decrease across all three types of oils. The OD of soybean and palm oils exhibited an upward trend, whereas that of mustard oil initially displayed a decline, followed by a gradual ascent. In comparison to soybean and mustard oils, palm oil exhibited the most noteworthy escalation in FFA, PV, SV, and OD parameters. The levels of FFA, PV, SV, and oxidative stability in palm oil exhibited an increase from 0.23 to 2.6 mg KOH/g sample, 5.0 to 10.2 m.eq/kg, 195 to 206 mg KOH/g sample, and 0.37 to 0.85, respectively. Conversely, IV decreased from 51 to 43 g I2/100 g. Sensory evaluation revealed that the palatability of food items fried in palm oil and soybean oil was comparable, with the products fried in mustard oil being ranked lower in terms of acceptability
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