Publications by authors named "Guerin K"

Article Synopsis
  • - Li(NiCoAl)O is a long-time lithium-ion battery cathode known for its high energy capacity and density but moderate power, making it a reliable choice for energy storage.
  • - Atomic layer fluorination (ALF) with XeF is used to enhance the battery's cyclability by creating a protective fluorinated layer with minimal fluorine content (only 1.4 wt%).
  • - Various characterization techniques show that adding fluorine improves the electrochemical performance of Li(NiCoAl)O, enhancing its cyclability, polarization, and rate capability, with further insights into these benefits obtained from infrared spectroscopy and gas chromatography.
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Article Synopsis
  • This research focuses on creating innovative cathode materials for lithium-ion batteries (LIBs) by substituting traditional elements like nickel and manganese with more sustainable alternatives, copper and iron.
  • The study aims to improve the cycling stability of the cathodes by replacing oxygen with fluorine, utilizing a new composite blend of CuF and FeF produced through a unique fluorination method involving layered double hydroxides (LDHs).
  • Extensive characterization techniques were employed to analyze the materials post-fluorination, revealing interesting structural changes and stable crystallographic phases that could enhance the performance of these batteries.
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Sub-fluorinated carbon nanofibers (F-CNFs) can be described as a non-fluorinated core surrounded by a fluorocarbon lattice. The core ensures the electron flux in the cathode during the electrochemical discharge in the primary lithium battery, which allows a high-power density to be reached. The ball-milling in an inert gas (Ar) of these F-CNFs adds a second level of conductive sp carbons, i.

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Thanks to their high initial electrochemical properties and broad compositional flexibility, lithium-rich disordered rocksalt cathode-active materials including high-performance manganese-only materials appear as a potential replacement to the cobalt-based current market leader "NMC" material. The main issue with these materials is their lack of stability. However, recent works have identified bulk fluorination as a potential solution to stabilize these compounds.

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Adeno-associated viral vectors (AAV) are frequently used by neuroscientists to deliver tools, such as biosensors and optogenetic and chemogenetic actuators, . Despite its widespread use, AAV vector characterization and quality control can vary between labs and viral vector cores leading to variable results and irreproducibility. This protocol describes some of the characterization and quality control assays necessary to confirm an AAV vector's titer, genomic identity, serotype and purity.

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The benefit of enriching solid-electrolyte interface with fluorine atoms through the use of fluorinated additives into the electrolyte composition has recently gained popularity for anode materials used in secondary lithium-ion batteries. Another strategy is to provide these fluorine atoms via surface fluorination of the electrode material, particularly for multiwalled carbon nanotube (MWCNT)/SnO-based composites where fluorination must act selectively on SnO. Our study presents two methods of surface fluorination applied on MWCNT/SnO, one using F(g) and the other XeF(s).

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Background: Medication management, a complex yet essential part of patient care, requires that clinicians and patients understand indication, dosage, frequency, and adverse effects in order to maximize benefits and minimize errors, as well as to transition patients from hospital to home. Clinical pharmacists improve care transitions and safety by interacting with patients, prescribers, and nurses on medication management and self-care. However, little is known on the use of clinical pharmacists on interdisciplinary teams at the unit level within orthopedics.

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Superstructures or self-assembled nanoparticles open the development of new materials with improved and/or novel properties. Here, we present nickel fluoride (NiF) self-assemblies by successive preparatory methods. Originally, the self-assemblies were obtained by exploiting the water-in-oil microemulsion technique as a result of auto-organization of hydrated NiF (NiF·4HO) nanoparticles.

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Recombinant adeno-associated virus (rAAV) vectors are increasingly popular gene delivery tools in biological systems. They are safe and lead to high-level, long-term transgene expression. rAAV are available in multiple serotypes, natural or engineered, which enable targeting to a wide array of tissues and cell types.

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Cell-type-specific expression of molecular tools and sensors is critical to construct circuit diagrams and to investigate the activity and function of neurons within the nervous system. Strategies for targeted manipulation include combinations of classical genetic tools such as Cre/loxP and Flp/FRT, use of cis-regulatory elements, targeted knock-in transgenic mice, and gene delivery by AAV and other viral vectors. The combination of these complex technologies with the goal of precise neuronal targeting is a challenge in the lab.

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The promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here we report the use of a processor with programmable superconducting qubits to create quantum states on 53 qubits, corresponding to a computational state-space of dimension 2 (about 10).

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Secondary transporters exist as monomers, dimers or higher state oligomers. The significance of the oligomeric state is only partially understood. Here, the significance of the trimeric state of the L-carnitine/γ-butyrobetaine antiporter CaiT of Escherichia coli was investigated.

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The available structural information on LeuT and structurally related transporters suggests that external loop 4 (eL4) and the outer end of transmembrane domain (TM) 10' participate in the reversible occlusion of the outer pathway to the solute binding sites. Here, the functional significance of eL4 and the outer region of TM10' are explored using the sodium/proline symporter PutP as a model. Glu-311 at the tip of eL4, and various amino acids around the outer end of TM10' are identified as particularly crucial for function.

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A new and original gas sensor-system dedicated to the selective monitoring of nitrogen dioxide in air and in the presence of ozone, has been successfully achieved. Because of its high sensitivity and its partial selectivity towards oxidizing pollutants (nitrogen dioxide and ozone), copper phthalocyanine-based chemoresistors are relevant. The selectivity towards nitrogen dioxide results from the implementation of a high efficient and selective ozone filter upstream the sensing device.

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In order to enhance the durability of chemical filters for ozone molecules, devoted to microsystem for the selective detection of NO2 in the environment, the adsorption of indigo molecules onto the surface of carbonaceous nanomaterials (multi-walled carbon nanotubes, a mixture of nanodisks/nanocones, nanofibres) was investigated. The surface of the multi-walled carbon nanotubes was coated by π-stacking with adsorbed indigo molecules. An excess of indigo has resulted in a biphasic sample where nanotubes covered with indigo coexist with free indigo particles.

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Background: Screening patients for methicillin-resistant Staphylococcus aureus (MRSA) colonization and contact precautions for colonized patients has been recommended when other control measures have been ineffective.

Methods: We compared MRSA transmission rates following implementation of a bundle of control measures that included institutional culture change, surveillance for MRSA infection and transmission, and active screening for colonization in 2 similar Veterans Health Administration hospitals. One hospital employed contact precautions as defined by the Centers for Disease Control and Prevention, and the other hospital modified contact precautions, requiring only the use of gloves.

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Covalent functionalization through pure molecular gaseous fluorination has been applied on carbon nanofibres. Nuclear magnetic resonance and thermal gravimetric analysis investigations have been performed on fluorinated carbon nanofibres in order to determine the chemical and thermal stability of the C-F bonding. The high covalency obtained allows no significant modification of the physicochemical nanostructure of fluorinated carbon nanofibres after sonification.

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Solid state NMR measurements using 13C, 1H and 19F nuclei (MAS, CP-MAS) underline the surface chemistry of nanodiamonds from different synthesis (detonation, high pressure high temperature and shock compression). The comparison of the spin-lattice relaxation times T1 and physicochemical characterization (spin densities of dangling bonds, specific surface area and Raman and infrared spectroscopies) for the various samples, as synthesized, chemically purified and fluorinated allows the nature and the location of the various groups, mainly C-OH, C-H and C-F to be investigated. C-OH groups are located only on the surface whereas C-H and dangling bonds seem to be distributed in the whole volume.

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Background: Ischemic proliferative retinopathy, characterized by pathological retinal neovascularization, is a major cause of blindness in working-age adults and children. Defining the molecular pathways distinguishing pathological neovascularization from normal vessels is critical to controlling these blinding diseases with targeted therapy. Because mutations in Wnt signaling cause defective retinal vasculature in humans with some characteristics of the pathological vessels in retinopathy, we investigated the potential role of Wnt signaling in pathological retinal vascular growth in proliferative retinopathy.

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Mutations in over 80 identified genes can induce apoptosis in photoreceptors, resulting in blindness with a prevalence of 1 in 3,000 individuals. This broad genetic heterogeneity of disease impacting a wide range of photoreceptor functions renders the design of gene-specific therapies for photoreceptor degeneration impractical and necessitates the development of mutation-independent treatments to slow photoreceptor cell death. One promising strategy for photoreceptor neuroprotection is neurotrophin secretion from Müller cells, the primary retinal glia.

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Purpose: Macular telangiectasia (MacTel) is a vision-threatening retinal disease with unknown pathogenesis and no approved treatment. Very low-density lipoprotein receptor mutant mice (Vldlr(-/-)) exhibit critical features of MacTel such as retinal neovascularization and photoreceptor degeneration. In this study, the authors evaluate the therapeutic potential of resveratrol, a plant polyphenol, in Vldlr(-/-) mice as a model for MacTel.

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The gas filtering abilities of different nanocarbon materials such as nanocones/nanodiscs, and nanofibres, either as-prepared or modified by physical (annealing, grinding) or chemical (fluorination) treatment are reported. The aptitude to filter nitrogen dioxide and ozone, two of the most significant gaseous pollutants of the atmosphere, have been correlated to both the BET specific surface area studied by N2 adsorption at 77 K, and the presence of chemical functional groups at the surface. Valuable information regarding the mechanisms of gas-nanocarbon interaction has been obtained, in terms of chemisorption and physisorption.

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Conservation of normal cognitive functions relies on the proper performance of the nervous system at the cellular and molecular level. The mammalian nicotinamide-adenine dinucleotide-dependent deacetylase SIRT1 impacts different processes potentially involved in the maintenance of brain integrity, such as chromatin remodeling, DNA repair, cell survival, and neurogenesis. Here we show that SIRT1 is expressed in neurons of the hippocampus, a key structure in learning and memory.

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Rationale: Omega3 long-chain polyunsaturated fatty acids (omega3-PUFAs) are powerful modulators of angiogenesis. However, little is known about the mechanisms governing omega3-PUFA-dependent attenuation of angiogenesis.

Objective: This study aims to identify a major mechanism by which omega3-PUFAs attenuate retinal neovascularization.

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Background: Central line-associated bloodstream infections (CLABSIs) cause substantial morbidity and incur excess costs. The use of a central line insertion bundle has been shown to reduce the incidence of CLABSI. Postinsertion care has been included in some studies of CLABSI, but this has not been studied independently of other interventions.

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