172 results match your criteria: "Institute of Chemical Sciences and Engineering (ISIC)[Affiliation]"

Assessment of fine-tuned large language models for real-world chemistry and material science applications.

Chem Sci

November 2024

Laboratory of Molecular Simulation (LSMO), Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) Rue de l'Industrie 17 CH-1951 Sion Switzerland

The current generation of large language models (LLMs) has limited chemical knowledge. Recently, it has been shown that these LLMs can learn and predict chemical properties through fine-tuning. Using natural language to train machine learning models opens doors to a wider chemical audience, as field-specific featurization techniques can be omitted.

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Slow-Binding and Covalent HDAC Inhibition: A New Paradigm?

JACS Au

November 2024

Laboratory of Chemistry and Biophysics of Macromolecules (LCBM), Institute of Chemical Sciences and Engineering (ISIC), School of Basic Sciences, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.

The dysregulated post-translational modification of proteins is an established hallmark of human disease. Through Zn-dependent hydrolysis of acyl-lysine modifications, histone deacetylases (HDACs) are key regulators of disease-implicated signaling pathways and tractable drug targets in the clinic. Early targeting of this family of 11 enzymes (HDAC1-11) afforded a first generation of broadly acting inhibitors with medicinal applications in oncology, specifically in cutaneous and peripheral T-cell lymphomas and in multiple myeloma.

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Distribution and diversity of classical deacylases in bacteria.

Nat Commun

November 2024

Department Synthetic and Structural Biochemistry, Institute of Biochemistry, University of Greifswald, Greifswald, Germany.

Classical Zn-dependent deac(et)ylases play fundamental regulatory roles in life and are well characterized in eukaryotes regarding their structures, substrates and physiological roles. In bacteria, however, classical deacylases are less well understood. We construct a Generalized Profile (GP) and identify thousands of uncharacterized classical deacylases in bacteria, which are grouped into five clusters.

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RIP1 inhibition protects retinal ganglion cells in glaucoma models of ocular injury.

Cell Death Differ

October 2024

Department of Immunology Discovery, Genentech, 1 DNA Way, South San Francisco, CA, USA.

Receptor-interacting protein 1 (RIP1, RIPK1) is a critical mediator of multiple signaling pathways that promote inflammatory responses and cell death. The kinase activity of RIP1 contributes to the pathogenesis of a number of inflammatory and neurodegenerative diseases. However, the role of RIP1 in retinopathies remains unclear.

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Dinitrogen Reduction and Functionalization by a Siloxide Supported Thulium-Potassium Complex for the Formation of Ammonia or Hydrazine Derivatives.

Angew Chem Int Ed Engl

October 2024

Group of Coordination Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.

The dinitrogen (N) chemistry of lanthanides remains less developed compared to the d-block metals and lanthanide-promoted N functionalization chemistry in well-defined lanthanide complexes remains elusive. Here we report the synthesis and characterization (SQUID, EPR, DFT, X-Ray) of the siloxide supported heterobimetallic (Tm/K) complexes [{KTm(OSi(OBu))}(μ-η : η-N)] (1) and [K{Tm(OSi(OBu))}(μ-η : η-N)] (2). Complex 2 provides a rare example of a metal complex of the triply reduced N radical.

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A Site-Specific Click Chemistry Approach to Di-Ubiquitylate H1 Variants Reveals Position-Dependent Stimulation of the DNA Repair Protein RNF168.

Angew Chem Int Ed Engl

December 2024

Laboratory of Biophysical Chemistry of Macromolecules (LCBM), Institute of Chemical Sciences and Engineering (ISIC), EPFL (Ecole Polytechnique Fédérale de Lausanne), Station 6, 1015, Lausanne, Switzerland.

Ubiquitylation of histone H2A at lysines 13 and 15 by the E3 ligase RNF168 plays a key role in orchestrating DNA double-strand break (DSB) repair, which is often deregulated in cancer. RNF168 activity is triggered by DSB signaling cascades, reportedly through K63-linked poly-ubiquitylation of linker histone H1. However, direct experimental evidence of this mechanism has been elusive, primarily due to the lack of methods to specifically poly-ubiquitylate H1.

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Free Charge Carrier Generation by Visible-Light-Absorbing Organic Spacers in Ruddlesden-Popper Layered Perovskites.

J Am Chem Soc

October 2024

Laboratory for Molecular Engineering of Optoelectronic Nanomaterials, Institute of Chemical Sciences and Engineering (ISIC), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.

Incorporating organic semiconductor building blocks as spacer cations into layered hybrid perovskites provides an opportunity to develop new materials with novel optoelectronic properties, including nanoheterojunctions that afford spatial separation of electron and hole transport. However, identifying organics with suitable structure and electronic energy levels to selectively absorb visible light has been a challenge in the field. In this work, we introduce a new lead-halide-based Ruddlesden-Popper perovskite structure based on a visible-light-absorbing naphthalene-iminoimide cation (NDI-DAE).

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Accelerated design of nickel-cobalt based catalysts for CO hydrogenation with human-in-the-loop active machine learning.

Catal Sci Technol

October 2024

Laboratory of Materials for Renewable Energy (LMER), Institute of Chemical Sciences and Engineering (ISIC), Basic Science Faculty (SB), École Polytechnique Fédérale de Lausanne (EPFL) Valais/Wallis, Energypolis Rue de l'Industrie 17 1951 Sion Switzerland

Thermo-catalytic conversion of CO into more valuable compounds, such as methane, is an attractive strategy for energy storage in chemical bonds and creating a carbon-based circular economy. However, designing heterogeneous catalysts remains a challenging, time- and resource-consuming task. Herein, we present an interpretable, human-in-the-loop active machine learning framework to efficiently plan catalytic experiments, execute them in an automated set-up, and estimate the effect of experimental variables on the catalytic activity.

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Doping In Vivo Alkylation in E. coli by Introducing the Direct Sulfurylation Pathway of S. cerevisiae.

Angew Chem Int Ed Engl

September 2024

Institute of Pharmaceutical Sciences, University of Freiburg, Albertstr. 25, 79104, Freiburg, Germany.

Methylation and alkylation are important techniques used for the synthesis and derivatisation of small molecules and natural products. Application of S-adenosylmethionine (SAM)-dependent methyltransferases (MTs) in biotechnological hosts such as Escherichia coli lowers the environmental impact of alkylation compared to chemical synthesis and facilitates regio- and chemoselective alkyl chain transfer. Here, we address the limiting factor for SAM synthesis, methionine supply, to accelerate in vivo methylation activity.

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Multimeric membrane proteins are produced in the endoplasmic reticulum and transported to their target membranes which, for ion channels, is typically the plasma membrane. Despite the availability of many fully assembled channel structures, our understanding of assembly intermediates, multimer assembly mechanisms, and potential functions of non-standard assemblies is limited. We demonstrate that the pentameric ligand-gated serotonin 5-HT3A receptor (5-HT3AR) can assemble to tetrameric forms and report the structures of the tetramers in plasma membranes of cell-derived microvesicles and in membrane memetics using cryo-electron microscopy and tomography.

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Of the different modalities used to treat retinoblastoma, a chemothermotherapeutic regimen combining carboplatin and thermotherapy (also termed focal therapy), and the application of melphalan as a monotherapy, are particularly successful. Some studies indicate that melphalan shows potential when applied in combination with focal therapy, and yet is not applied in this combination. Here we describe a series of synthetically modified melphalan derivatives that display enhanced cytotoxicity relative to melphalan itself, with some displaying further enhancements in cytotoxicity when applied in combination with heat (used as a model for thermotherapy).

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Cysteine cathepsins are a family of proteases that are relevant therapeutic targets for the treatment of different cancers and other diseases. However, no clinically approved drugs for these proteins exist, as their systemic inhibition can induce deleterious side effects. To address this problem, we developed a modular antibody-based platform for targeted drug delivery by conjugating non-natural peptide inhibitors (NNPIs) to antibodies.

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Aspartate is crucial for nucleotide synthesis, ammonia detoxification, and maintaining redox balance via the malate-aspartate-shuttle (MAS). To disentangle these multiple roles of aspartate metabolism, tools are required that measure aspartate concentrations in real time and in live cells. We introduce AspSnFR, a genetically encoded green fluorescent biosensor for intracellular aspartate, engineered through displaying and screening biosensor libraries on mammalian cells.

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Colloidal Atomic Layer Deposition on Nanocrystals Using Ligand-Modified Precursors.

J Am Chem Soc

April 2024

Laboratory of Nanochemistry for Energy (LNCE), Institute of Chemical Sciences and Engineering (ISIC), École Polytechnique Fédérale de Lausanne, Sion CH-1950, Switzerland.

Atomic layer deposition (ALD) is a method to grow thin metal oxide layers on a variety of materials for applications spanning from electronics to catalysis. Extending ALD to colloidally stable nanocrystals promises to combine the benefits of thin metal oxide coatings with the solution processability of the nanocrystals. However, challenges persist in applying this method, which relate to finding precursors that promote the growth of the metal oxide while preserving colloidal stability throughout the process.

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Recent advances in Rh(I)-catalyzed enantioselective C-H functionalization.

Chem Soc Rev

April 2024

Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.

Chiral carbon-carbon (C-C) and carbon-heteroatom (C-X) bonds are pervasive and very essential in natural products, bioactive molecules, and functional materials, and their catalytic construction has emerged as one of the hottest research fields in synthetic organic chemistry. The last decade has witnessed vigorous progress in Rh(I)-catalyzed asymmetric C-H functionalization as a complement to Rh(II) and Rh(III) catalysis. This review aims to provide the most comprehensive and up-to-date summary covering the recent advances in Rh(I)-catalyzed C-H activation for asymmetric functionalization.

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Recordings of the physiological history of cells provide insights into biological processes, yet obtaining such recordings is a challenge. To address this, we introduce a method to record transient cellular events for later analysis. We designed proteins that become labeled in the presence of both a specific cellular activity and a fluorescent substrate.

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In semiconductors, exciton or charge carrier diffusivity is typically described as an inherent material property. Here, we show that the transport of excitons among CsPbBr perovskite nanocrystals (NCs) depends markedly on how recently those NCs were occupied by a previous exciton. Using transient photoluminescence microscopy, we observe a striking dependence of the apparent exciton diffusivity on excitation laser power that does not arise from nonlinear exciton-exciton interactions or thermal heating.

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Advancing Molecular Sieving via Å-Scale Pore Tuning in Bottom-Up Graphene Synthesis.

ACS Nano

February 2024

Laboratory for Advanced Separations (LAS), Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de l'industrie 17, 1950 Sion, Switzerland.

Porous graphene films are attractive as a gas separation membrane given that the selective layer can be just one atom thick, allowing high-flux separation. A favorable aspect of porous graphene is that the pore size, essentially gaps created by lattice defects, can be tuned. While this has been demonstrated for postsynthetic, top-down pore etching in graphene, it does not exist in the more scalable, bottom-up synthesis of porous graphene.

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A Universal Perovskite/C60 Interface Modification via Atomic Layer Deposited Aluminum Oxide for Perovskite Solar Cells and Perovskite-Silicon Tandems.

Adv Mater

May 2024

École Polytechnique Fédérale de Lausanne (EPFL), Institute of Electrical and Microengineering (IEM), Photovoltaics and Thin-Film Electronics Laboratory (PV-Lab), Rue de la Maladière 71b, Neuchâtel, 2002, Switzerland.

The primary performance limitation in inverted perovskite-based solar cells is the interface between the fullerene-based electron transport layers and the perovskite. Atomic layer deposited thin aluminum oxide (AlO) interlayers that reduce nonradiative recombination at the perovskite/C interface are developed, resulting in >60 millivolts improvement in open-circuit voltage and 1% absolute improvement in power conversion efficiency. Surface-sensitive characterizations indicate the presence of a thin, conformally deposited AlO layer, functioning as a passivating contact.

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Decoding Chromatin Ubiquitylation: A Chemical Biology Perspective.

J Mol Biol

April 2024

Laboratory of Biophysical Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland. Electronic address:

Since Strahl and Allis proposed the "language of covalent histone modifications", a host of experimental studies have shed light on the different facets of chromatin regulation by epigenetic mechanisms. Initially proposed as a concept for controlling gene transcription, the regulation of deposition and removal of histone post-translational modifications (PTMs), such as acetylation, methylation, and phosphorylation, have been implicated in many chromatin regulation pathways. However, large PTMs such as ubiquitylation challenge research on many levels due to their chemical complexity.

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Revealing chromatin-specific functions of histone deacylases.

Biochem Soc Trans

February 2024

Laboratory of Biophysical Chemistry of Macromolecules (LCBM), Institute of Chemical Sciences and Engineering (ISIC), School of Basic Sciences, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.

Histone deacylases are erasers of Nε-acyl-lysine post-translational modifications and have been targeted for decades for the treatment of cancer, neurodegeneration and other disorders. Due to their relatively promiscuous activity on peptide substrates in vitro, it has been challenging to determine the individual targets and substrate identification mechanisms of each isozyme, and they have been considered redundant regulators. In recent years, biochemical and biophysical studies have incorporated the use of reconstituted nucleosomes, which has revealed a diverse and complex arsenal of recognition mechanisms by which histone deacylases may differentiate themselves in vivo.

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Indium phosphide quantum dots (InP QDs) are a promising example of Restriction of Hazardous Substances directive (RoHS)-compliant light-emitting materials. However, they suffer from low quantum yield and instability upon processing under ambient conditions. Colloidal atomic layer deposition (c-ALD) has been recently proposed as a methodology to grow hybrid materials including QDs and organic/inorganic oxide shells, which possess new functions compared to those of the as-synthesized QDs.

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Elucidating the Mechanism of Fe Incorporation in In Situ Synthesized Co-Fe Oxygen-Evolving Nanocatalysts.

J Am Chem Soc

November 2023

Laboratory of Materials for Renewable Energy (LMER), Institute of Chemical Sciences and Engineering (ISIC), Basic Science Faculty (SB), École Polytechnique Fédérale de Lausanne (EPFL), Valais/Wallis, Energypolis, CH-1951 Sion, Switzerland.

Ni- and Co-based catalysts with added Fe demonstrate promising activity in the oxygen evolution reaction (OER) during alkaline water electrolysis, with the presence of Fe in a certain quantity being crucial for their enhanced performance. The mode of incorporation, local placement, and structure of Fe ions in the host catalyst, as well as their direct/indirect contribution to enhancing the OER activity, remain under active investigation. Herein, the mechanism of Fe incorporation into a Co-based host was investigated using an in situ synthesized Co-Fe catalyst in an alkaline electrolyte containing Co and Fe.

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Polo-like kinase (Plk4) is a serine/threonine-protein kinase that is essential for biogenesis of the centriole organelle and is enriched at centrioles. Herein, we introduce Cen-TCO, a chemical probe based on the Plk4 inhibitor centrinone, to image Plk4 and centrioles in live or fixed cultured human cells. Specifically, we established a bio-orthogonal two-step labeling system that enables the Cen-TCO-mediated imaging of Plk4 by STED super-resolution microscopy.

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A fluoropolymer bifunctional solid membrane interface for improving the discharge duration in aqueous Al-air batteries.

Chem Commun (Camb)

September 2023

Lab. of Materials for Renewable Energy (LMER), Institute of Chemical Sciences and Engineering (ISIC), Basic Science Faculty (SB), École Polytechnique Fédérale de Lausanne (EPFL) Valais/Wallis, Energypolis, Sion CH-1951, Switzerland.

Herein, a fluoropolymer bifunctional solid membrane interface (SMI) for an aqueous Al-air battery is proposed, which inhibits anodic self-corrosion, while concurrently reducing the accumulation of undesirable by-products. A battery using the SMI exhibits a remarkable anticorrosion efficiency of 81.31% and achieves an astonishing battery lifetime improvement rate of 184.

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