676 results match your criteria: "Institute of Condensed Matter and Nanosciences[Affiliation]"

Mixed Anionic and Cationic Redox Chemistry in a Tetrathiomolybdate Amorphous Coordination Framework.

Angew Chem Int Ed Engl

September 2020

Institute of Condensed Matter and Nanosciences, Molecular Chemistry, Materials and Catalysis, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium.

We report the electrochemistry of a hitherto unexplored Na MoS phase as a conversion electrode material for Na- and Li-ion batteries. The material adopts an amorphous coordination polymer structure with mixed Mo and S valences. XPS and XRD analysis reveal a complex interplay between Mo and S redox chemistry, while excluding the formation of free sulfur, lithium sulfide, or other crystalline phases.

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Solvent induced supramolecular polymorphism in Cu(II) coordination complex built from 1,2,4-triazolo[1,5-a]pyrimidine: Crystal structures and anti-oxidant activity.

J Inorg Biochem

July 2020

Institute of Condensed Matter and Nanosciences, Molecular Chemistry, Materials and Catalysis (IMCN/MOST), Université catholique de Louvain, Place L. Pasteur 1, 1348 Louvain-la-Neuve, Belgium. Electronic address:

Two Cu(II) coordination complexes, C1 and C2 of the formula [Cu(4)(HO)], have been prepared by reaction between CuCl·2HO and 7-ethoxycarbonylmethyl-5-methyl-1,2,4[1,5-a]pyrimidine (L) in a 1:2 M:L molar ratio. The L molecule decomposes during the reaction process into 7-carboxy-5-methyl-[1,2,4]-triazolo[1,5-a]pyrimidine (4) through an intermediate, ethyl 2,2-dihydroxy-2-(5-methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-yl)acetate (5), which has been isolated and its crystal structure determined by X-ray diffraction. The X-ray analysis of the single crystals of [Cu(4)(HO)] obtained from the slow evaporation of EtOH and MeOH, separately, revealed the formation of "solvent induced" polymorphs C1 and C2, respectively.

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Extensive experimental and theoretical investigations are reported on the nature of resonance-assisted hydrogen bonding phenomenon (RAHB) and its influence on photophysical properties of the newly designed dyes differing in donor-acceptor properties, namely ethyl N-salicylideneglycinate (1), ethyl N-(5-methoxysalicylidene)glycinate (2), ethyl N-(5-bromosalicylidene)glycinate (3) and ethyl N-(5-nitrosalicylidene)glycinate (4). All compounds are thermochromic in the solid state and they contain a typical intramolecular O-H⋅⋅⋅N hydrogen bond formed between the hydroxyl hydrogen atom and the imine nitrogen atom, yielding the enol form in the solid state. It is unveiled, that the magnitude of RAHB effect fine tunes the strength of the O-H⋅⋅⋅N bonding and accordingly the relative populations of the enol, cis-keto and trans-keto forms leading to variation of the photophysical properties of 1-4.

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Protein-based polyelectrolyte multilayers.

Adv Colloid Interface Sci

June 2020

Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Louis Pasteur, 1 bte L4.01.10, B-1348 Louvain-la-Neuve, Belgium.

The immobilization of proteins to impart specific functions to surfaces is topical for chemical engineering, healthcare and diagnosis. Layer-by-Layer (LbL) self-assembly is one of the most used method to immobilize macromolecules on surfaces. It consists in the alternate adsorption of oppositely charged species, resulting in the formation of a multilayer.

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Exploring the solid-state phases and thermodynamics of calcium l-lactate.

Food Chem

April 2020

Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Place Louis Pasteur 1/L4.01.03, 1348 Louvain-la-Neuve, Belgium. Electronic address:

Calcium l-lactate, an organic salt derived from l-lactic acid, is used in many fields such as food, pharmaceutical or cosmetic industry. To this date, its solid-state thermodynamics are still poorly understood: a pentahydrate crystalline and anhydrate amorphous forms were already characterized, and potential other hydrates mentioned in literature. For the development of a robust crystallization process or down-line handling of this compound, it is important to know and understand the relationship between the different solid forms to prevent uncontrolled crystallization or solid-solid transformation during storage.

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We present an overview of the onetep program for linear-scaling density functional theory (DFT) calculations with large basis set (plane-wave) accuracy on parallel computers. The DFT energy is computed from the density matrix, which is constructed from spatially localized orbitals we call Non-orthogonal Generalized Wannier Functions (NGWFs), expressed in terms of periodic sinc (psinc) functions. During the calculation, both the density matrix and the NGWFs are optimized with localization constraints.

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Balancing Ligand Flexibility versus Rigidity for the Stepwise Self-Assembly of M L via M L Metal-Organic Cages.

Chemistry

September 2020

Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Louis Pasteur 1, Louvain-la-Neuve, 1348, Belgium.

Non-covalent interactions are important for directing protein folding across multiple intermediates and can even provide access to multiple stable structures with different properties and functions. Herein, we describe an approach for mimicking this behavior in the self-assembly of metal-organic cages. Two ligands, the bend angles of which are controlled by non-covalent interactions and one ligand lacking the above-mentioned interactions, were synthesized and used for self-assembly with Pd .

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Enzyme-assisted mineralization of calcium phosphate: exploring confinement for the design of highly crystalline nano-objects.

Nanoscale

May 2020

Laboratoire de Biomécanique & Bioingénierie, CNRS, Université de Technologie de Compiègne, BP 20529, F-60205 Compiègne Cedex, France and Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface, LRS, F-75005 Paris, France.

In hard tissues of vertebrates, calcium phosphate (CaP) biomineralization is a fascinating process that combines specific physicochemical and biochemical reactions, resulting in the formation of extracellular matrices with elegant nanoarchitectures. Although several "biomimetic" strategies have been developed for the design of mineralized nanostructured biointerfaces, the control of the crystallization process remains complex. Herein, we report an innovative approach to overcome this challenge by generating, in situ, CaP precursors in a confined medium.

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The Thermoelectric Properties of -Type Bismuth Telluride: Bismuth Selenide Alloys BiTe Se .

Research (Wash D C)

March 2020

Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Cook Hall 2036, Evanston, IL 60208, USA.

Alloying bismuth telluride with antimony telluride and bismuth selenide for - and -type materials, respectively, improves the thermoelectric quality factor for use in room temperature modules. As the electronic and thermal transports can vary substantially, the alloy composition is a key engineering parameter. The -type BiTe Se alloy lags its -type counterpart in thermoelectric performance and does not lend itself as readily to simple transport modeling which complicates engineering.

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The surface charge of nanocarriers inevitably affects drug delivery efficiency; however, the cancer cell specificity, anti-inflammatory effects, and charge-reversal points remain to be further addressed in biomedical applications. The aim of this study was to comprehensively assess the cancer cell specificity of DOX-loaded mesoporous silica-chitosan oligosaccharide-carboxymethyl chitosan nanoparticles (DOX@MSNs-COS-CMC) in MCF-7 and HeLa cells, inhibit the production of inflammatory cytokines, and improve the drug accumulation in the tumor site. Intracellular results reveal that the retention time prolonged to 48 h in both HeLa and MCF-7 cells at pH 7.

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Cocrystallization-Induced Spontaneous Deracemization: A General Thermodynamic Approach to Deracemization.

Angew Chem Int Ed Engl

July 2020

Department of Molecular Chemistry, Materials and Catalysis, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Place Louis Pasteur, 1 bte L4.01.06, BE-1348, Louvain-La-Neuve, Belgium.

Processes leading to enantiomerically pure compounds are of utmost importance, in particular for the pharmaceutical industry. Starting from a racemic mixture, crystallization-induced diastereomeric transformation allows in theory for 100 % transformation of the desired enantiomer. However, this method has the inherent limiting requirement for the organic compound to form a salt.

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Design of Ultra-Thin PEO/PDMAEMA Polymer Coatings for Tunable Protein Adsorption.

Polymers (Basel)

March 2020

Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Louis Pasteur 1, bte L4.01.10, B-1348 Louvain-la-Neuve, Belgium.

Protein adsorption on solid surfaces provides either beneficial or adverse outcomes, depending on the application. Therefore, the desire to predict, control, and regulate protein adsorption on different surfaces is a major concern in the field of biomaterials. The most widely used surface modification approach to prevent or limit protein adsorption is based on the use of poly (ethylene oxide) (PEO).

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The development of a functional model for microcirculation is an unresolved challenge, with major impact for the creation and regeneration of organs in the tissue engineering. The absence of prevascularized engineered tissues limits enormously their efficacy and integration. Therefore, in this study, the formation of tubular-like structures with human umbilical vein endothelial cells (HUVECs) is investigated thanks to three-dimensional polycarbonate (PC) microchannel (μCh) scaffolds, surface biofunctionalized with hyaluronic acid/chitosan (HA/CHI) layer-by-layer (LbL) films grafted with adhesive (RGD) and angiogenic (SVV and QK) peptides, alone and in combination.

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Strain Modulated Superlattices in Graphene.

Nano Lett

May 2020

Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.

Numerous theoretically proposed devices and novel phenomena have sought to take advantage of the intense pseudogauge fields that can arise in strained graphene. Many of these proposals, however, require fields to oscillate with a spatial frequency smaller than the magnetic length, while to date only the generation and effects of fields varying at a much larger length scale have been reported. Here, we describe the creation of short wavelength, periodic pseudogauge-fields using rippled graphene under extreme (>10%) strain and study of its effects on Dirac electrons.

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Photodynamic Therapy-Based Dendritic Cell Vaccination Suited to Treat Peritoneal Mesothelioma.

Cancers (Basel)

February 2020

Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), UCLouvain, 1200 Brussels, Belgium.

The potential of dendritic cell (DC)-based immunotherapy to treat cancer is, nowadays, well documented. Still, the clinical success of immune checkpoint inhibitors has dampened the interest in anticancer DC vaccination. For highly life-threatening tumors that are regarded as nonimmunogenic, such as mesothelioma, however, T helper 1 immunity-biased DC-based immunotherapy could still represent an attractive strategy.

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Deubiquitinating enzymes (DUBs) are a growing target class across multiple disease states, with several inhibitors now reported. b-AP15 and VLX1570 are two structurally related USP14/UCH-37 inhibitors. Through a proteomic approach, we demonstrate that these compounds target a diverse range of proteins, resulting in the formation of higher molecular weight (MW) complexes.

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Kolbe Anodic Decarboxylation as a Green Way To Access 2-Pyrrolidinones.

Org Lett

March 2020

Institute of Condensed Matter and Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST) unit, Université Catholique de Louvain (UCL), Place Louis Pasteur 1, 1348 Louvain-la-Neuve, Belgium.

Nootropic compounds are a group of pharmacologically active pyrrolidones. These molecules, which enhance cognition properties and possess a large prescription field, are particularly interesting synthetic targets for the pharmaceutical industry. In this Article, we disclose an effective and environmentally friendly pyrrolidinone synthesis using electrosynthesis.

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The encapsulation of copper inside a cyclodextrin capped with an N-heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)CuH and a cavity-controlled chemoselective copper-catalyzed hydrosilylation of α,β-unsaturated ketones. Remarkably, (α-ICyD)CuCl promoted the 1,2-addition exclusively, while (β-ICyD)CuCl produced the fully reduced product. The chemoselectivity is controlled by the size of the cavity and weak interactions between the substrate and internal C-H bonds of the cyclodextrin.

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The Limited Predictive Power of the Pauling Rules.

Angew Chem Int Ed Engl

May 2020

Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, 1348, Louvain-la-Neuve, Belgium.

The Pauling rules have been used for decades to rationalise the crystal structures of ionic compounds. Despite their importance, there has been no statistical assessment of the performances of these five empirical rules so far. Here, we rigorously and automatically test all five Pauling rules for a large data set of around 5000 known oxides.

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The tin sulfides and selenides have a range of applications spanning photovoltaics and thermoelectrics to photocatalysts and photodetectors. However, significant challenges remain to widespread use, including electrical and chemical incompatibilities between SnS and device contact materials and the environmental toxicity of selenium. Solid solutions of isostructural sulfide and selenide phases could provide scope for optimizing physical properties against sustainability requirements, but this has not been comprehensively explored.

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Phendione-Transition-Metal Complexes with Bipolar Redox Activity for Lithium Batteries.

ChemSusChem

May 2020

Institute of Condensed Matter and Nanosciences, Molecular Chemistry, Materials and Catalysis Division (IMCN/MOST), Université Catholique de Louvain, Place Louis Pasteur 1, Louvain-la-Neuve, Belgium.

1,10-Phenanthroline-5,6-dione (phendione)-based transition-metal complexes are known for their use in pharmacological and catalysis applications. However, their application in electrochemical energy storage has not been investigated thus far. Herein, the feasibility of employing phendione-transition-metal complexes was investigated for electrochemical charge storage by taking advantage of the reversible redox activity of both carbonyl groups and transition metal center, contributing to augmented charge storage.

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Enhancing Luminescence and Controlling the Mn Valence State of GdGaAlO:Mn Phosphors by the Design of the Garnet Structure.

ACS Appl Mater Interfaces

February 2020

State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun , Jilin 130022 , People's Republic of China.

GdGaAlO:Mn solid solutions with improving luminescence properties were prepared via cation substitution and a controllable Mn valence state. The abnormal autoreduction from Mn to Mn ions was observed during the formation of GdGaAlO:Mn. The doped manganese ions occupy octahedral Ga(1) and Al(1) sites to form the Mn luminescent center with red emission at 630 nm and Mn luminescent centers with deep red light emission at 698 nm, respectively, matching well with the red light absorption of phytochrome (P) and the far-red light absorption of phytochrome (P).

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Non-Isothermal Kinetics of Kr Adsorption by Nanoporous γ-Mg(BH) from in Situ Synchrotron Powder Diffraction.

ACS Appl Mater Interfaces

February 2020

Swiss-Norwegian Beamlines at the European Synchrotron Radiation Facility , 71 avenue des Martyrs , Grenoble 38000 , France.

Crystalline materials with pore dimensions comparable to the kinetic diameters of the guest molecules are attractive for their potential use in adsorption and separation applications. The nanoporous γ-Mg(BH) features one-dimensional channels matching this criterion for Kr uptake, which has been probed using synchrotron powder diffraction at various pressures and temperatures. It results in two coexisting crystalline phases with the limiting composition Mg(BH)·0.

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An antioxidant material composed of halloysite nanotubes (HNTs), protamine sulfate polyelectrolyte (PSP), and superoxide dismutase (SOD) enzyme was prepared by self-assembly of the PSP and SOD biomacromolecules on the nanoparticulate support. The structural, colloidal and biocatalytic features were assessed. Adsorption of PSP on the oppositely charged HNT surface at appropriate loadings gave rise to charge neutralization and overcharging, which resulted in unstable and stable dispersions, respectively.

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Carbonyl-Based π-Conjugated Materials: From Synthesis to Applications in Lithium-Ion Batteries.

Chempluschem

September 2019

Institute of Information and Communication Technologies, Electronics and Applied Mathematics, Electrical Engineering, Université catholique de Louvain, Place du Levant 3, B-1348, Louvain-la-Neuve, Belgium.

The constant growth in the global energy demand together with the increasing awareness of clean and sustainable development has strongly pushed scientists to search for metal-free, low-cost, environmentally friendly functional energy-storage systems (ESSs). Among the reported organic electrode materials, carbonyl-based π-conjugated compounds show excellent rate capabilities and cycling stabilities and are powerful candidates for the next generation of rechargeable lithium-ion batteries (LIBs). Benefiting from the molecular structure versatility and design feasibility, the electrochemical properties of organic and polymeric materials can be easily tuned.

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