10,217 results match your criteria: "Institute of Physical Chemistry[Affiliation]"

The double-perovskite material CsTiBr shows excellent photovoltaic potential, making it a promising alternative to lead-based materials. However, its high susceptibility to degradation in air has raised concerns about its practical application. This study introduces an interesting synthesis approach that significantly enhances the stability of CsTiBr powder.

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Despite a large amount of theoretical and experimental work performed so far, the search of phase change materials (PCMs) is done with use of numerical modeling. However, it is not fully clear how and why the phase change translates into the optical contrast. In this work, we argue that a key prerequisite for a material to have a pronounced difference in optical properties between crystalline and glassy phases of PCM is the similar contrast between the observed crystalline and (may be experimentally inaccessible) parent crystalline polymorph of the glassy phase.

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Beneficial Soil Fungus Kills Predatory Nematodes with Dehydropeptides Translocating into the Animal Gut.

J Am Chem Soc

December 2024

Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Beutenbergstraße 11a, 07745 Jena, Germany.

is a mold fungus that has gained attention for its positive correlation with soil health, plant growth, and applications as a crop biocontrol agent to suppress the threats of nematode pests. To date, the mechanisms underlying the protective traits of against these plant parasites have remained elusive. Here we report that abundantly produced peptidic biosurfactants, malpinin A-D, exhibit robust inhibitory activity against nematodes.

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Article Synopsis
  • The study examines how Couette flow impacts knotted linear polymer chains through molecular dynamics simulations, focusing on their behavior under shear stress.
  • Knotted polymers initially in a coil state tend to have their knots tighten when subjected to high shear rates, while displaying tumbling motion that causes fluctuations in knot sizes.
  • Sheared knotted globular structures transform into a complex arrangement resembling a pearl necklace, where new knot types can emerge as the polymer reorganizes.
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Local Hydrogen Concentration and Distribution in Pd Nanoparticles: An In Situ STEM-EELS Approach.

Small

December 2024

Institute for Applied Materials - Materials Science and Engineering (IAM-WK), Karlsruhe Institute of Technology, Engelbert-Arnold-Straße 4, 76131, Karlsruhe, Germany.

Local detection of hydrogen concentration in metals is of central importance for many areas of hydrogen technology, such as hydrogen storage, detection, catalysis, and hydrogen embrittlement. A novel approach to measure the hydrogen concentration in a model system consisting of cubic palladium nanoparticles (Pd NPs), with a lateral resolution down to 4 nm is demonstrated. By measuring the shift of the Pd bulk plasmon peak with scanning transmission electron microscopy (STEM) combined with energy electron loss spectroscopy (EELS) during in situ hydrogen gas loading and unloading, local detection of the hydrogen concentration is achieved in TEM.

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Controlled encapsulation of colloidal semiconductor quantum dots in a microdroplet.

Phys Chem Chem Phys

December 2024

Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100 Toruń, Poland.

Precise deposition of materials on surfaces is one of the crucial steps in a broad range of applications and functional device fabrication at both the micro- and nanoscale. Semiconductor quantum dots (QDs), with their unique optical and physical properties, have frequently been a focus of attempts for micro- or nano-positioning. Here, we present a method for reproducible, repetitive, and precise deposition of QD-containing microdroplets using hydrophobic micropipettes without any need to apply an actuation voltage.

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Herein, we report a method for the preparation of the first odd homometallic and heterovalent nine-centered Tc wheel, [Tc(μ-O)Cl(OOCCl)]. The synthesized compound represents the pioneering instance of such clusters among d elements and is the fourth instance observed across all metals. The ring was synthesized by a solvothermal method in a solution of technetium acid in trichloroacetic anhydride.

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Understanding protein adsorption on the surface of nanoparticles (NPs) is crucial for determining their behavior in biological environments. Early research in this field faced challenges in producing high-quality NPs. Advancements in NP fabrication now allow for precise modifications of specific parameters, such as zeta potential.

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Article Synopsis
  • - Critical Casimir forces act on particles in a near-critical fluid, allowing researchers to manipulate particle behavior based on surface properties and small temperature changes.
  • - The study explores how these forces can trap colloidal particles by using specially designed substrates with contrasting surface properties, enabling different levitation effects like sedimentation and point levitation.
  • - By analyzing various parameters, the research indicates that while the conditions for point levitation become limited when moved away from critical points, the trapping force increases, highlighting potential applications in sorting colloids by size and measuring thermodynamic properties.
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A hollow cathode discharge with a copper nickel cathode (Cu50Ni50) was operated in an Ar/H/N gas mixture. Optical emission spectroscopy revealed the formation of NH radicals, which serve as precursors for NH formation. Ion mass spectrometry showed the formation of NH and NH ions indicating NH formation.

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Photosynthetic protists, named microalgae, are key players in global primary production. The green microalga Chlamydomonas reinhardtii is a well-studied model organism. In nature, it dwells in acetate-rich paddy rice soil, which is not mimicked by standard liquid laboratory conditions.

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Expression of concern: An impedimetric immunosensor based on diamond nanowires decorated with nickel nanoparticles.

Analyst

December 2024

Institut de Recherche Interdisciplinaire (IRI), CNRS USR 3078, Université Lille1, Parc de la Haute Borne, 50 avenue de Halley, BP 70478, 59658 Villeneuve d'Ascq, France.

Expression of concern for 'An impedimetric immunosensor based on diamond nanowires decorated with nickel nanoparticles' by Palaniappan Subramanian , , 2014, , 1726-1731, https://doi.org/10.1039/C3AN02045B.

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Vacuum-Assisted Confined Growth of MOF@COF Composite Membranes with Enhanced Hydrogen Permselectivity.

Angew Chem Int Ed Engl

December 2024

State Key Laboratory of Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500, Dongchuan Road, Shanghai, 200241, China.

Article Synopsis
  • Covalent organic frameworks (COFs) have potential for creating high-quality separation membranes but face challenges in gas separation due to larger pore sizes.
  • The study introduces a novel method by embedding the metal-organic framework (MOF) ZIF-8 within TB-COF to enhance gas separation properties.
  • The resulting ZIF-8@TB-COF membrane achieves significantly increased hydrogen selectivity for separating gas mixtures compared to traditional COF membranes, demonstrating the effectiveness of this new synthesis approach.
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Aqueous oxidation of pinanediol (PND) and camphanediol (CND) by hydroxyl radical (OH) was investigated using gas and liquid chromatography coupled with mass spectrometry. The yields of the products formed were measured with authentic and surrogate standards. This approach quantified >97% of the products for both reactions under investigation.

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Hot electrons (HEs) represent out-of-equilibrium carriers that are capable of facilitating reactions which are inaccessible under conventional conditions. Despite the similarity of the HE process to catalysis, optimization strategies such as orbital alignment and adsorption kinetics have not received significant attention in enhancing the HE-driven reaction yield. Here, we investigate catalytic effects in HE-driven reactions using a compositional catalyst modification (CCM) approach.

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Uranium forms a large number of oxides and its electronic state in them is of great fundamental interest. We employ X-ray absorption spectroscopy at the U L edge to differentiate between mixed oxide phases in uranium compounds. By combining experimental XANES spectra with theoretical modeling using the FEFF code, we analyze five uranium oxides: UO, UO, UO, UO, and UO.

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Research on gold nanoparticles (Au NPs) remains a field of intense activity due to their broad range of applications in diverse fields like catalysis, renewable energy, environmental science, and medicine. Herein, the morphological and electronic structures investigation of Au NPs prepared at different pH values is reported. The dependence of the localized surface plasmon resonance wavelength and electronic structure with size was determined by combining transmission electron microscopy, and various spectroscopic methods led by X-ray absorption spectroscopy.

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This research elucidates the intricate nature of electronic coupling in the redox-active (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), commonly utilized in organic radical batteries. This study employs a combination of classical molecular dynamics and various electronic coupling calculation schemes. Within the context of the generalized Mulliken-Hush method, the electronic couplings are investigated via the complete active space self-consistent field approach, in combination with n-electron valence state perturbation theory, to provide an accurate description of both static and dynamic electron correlation as well as using (time-dependent) density functional theory simulations.

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Leukemic microenvironment has been recognized as a factor that strongly supports the mechanisms of resistance. Therefore, targeting the microenvironment is currently one of the major directions in drug development and preclinical studies in leukemia. Despite the variety of available leukemia 3D culture models, the reproducible generation of miniaturized leukemic microenvironments, suitable for high-throughput drug testing, has remained a challenge.

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Prebiotic chemistry and protocells during the faint young sun event.

Biophys Rev

October 2024

Space Science Center (ANGKASA), Institute of Climate Change, National University of Malaysia, 43600 Selangor, Malaysia.

The sun generates light and heat for life on Earth to flourish. However, during the late Hadean-early Archean epoch on Earth, the "faint young sun" (FYS) was less luminous, influencing prebiotic chemistry and, by extension, the origins of life (OoL). However, higher levels of ultraviolet (UV) radiation from the FYS, especially UV-C, due to the lack of an ozone layer, would likely have impacted the assembly, stability, persistence, and functions of prebiotic cellular precursors, i.

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Article Synopsis
  • This study examines how guest molecules, such as proteins and nanoparticles, interact with pH-responsive polyelectrolyte microgels, which are useful for drug delivery as nanocarriers.
  • Researchers used Monte Carlo simulations to simplify the system by modeling guest molecules as charged beads, exploring various factors like charge, size, number, and salt influence on microgel properties.
  • Findings reveal that higher charge on guest molecules increases microgel ionization and can lead to microgel collapse due to attractive interactions, while larger molecules cause swelling, and the presence of salt affects uptake by screening electrostatic interactions.
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Using as example the [Fe(bpca)(μ-bpca)Gd(NO)]×4CHNO×CHOH system, where Hbpca=bis(2-pyridilcarbonyl)amine), we perform the analysis of bonding components inside the d and f coordination units and between molecular entities from crystal. Aside the nominal long-range interactions between molecular components of the crystal, we considered that the bonding inside the coordination units is also not a covalent regime. We performed Density Functional Theory (DFT) calculations, with plane-waves (PW), in band-structure mode, and with atom-centred bases, by molecular procedures.

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Novel techniques to quantitatively assess age-dependent alterations in biophysical properties of HSPCs and bone marrow niche.

Exp Hematol

November 2024

Center for Integrative Medicine and Physics, Institute for Advances Study, Kyoto University, Kyoto, Japan; Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, Heidelberg, Germany. Electronic address:

The present knowledge on hematopoietic stem and progenitor cell (HSPC) biology and aging is based largely on studies in mouse models. Although mouse models are invaluable, they are not without limitations for defining how physical properties of HSPCs and their niche change with age. The bone marrow (BM) niche is a complex, interactive environment with multiple cell types.

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To understand the recently observed enigmatic nonadiabatic energy transfer for hyperthermal H atom scattering from a semiconductor surface, Ge(111)(2 × 8), we present a mixed quantum-classical nonadiabatic molecular dynamics model based on the time-dependent evolution of Kohn-Sham orbitals and a classical path approximation. Our results suggest that facile nonadiabatic electronic transitions from the valence band to the conduction band occur selectively at the rest atom site, where surface states are doubly occupied, but not at the adatom site, where empty surface states are localized. This drastic site specificity can be attributed to the changes of the local band structure upon energetic H collisions at different surface sites, leading to transient near degeneracies and significant couplings between occupied and unoccupied orbitals at the rest atom but not at the adatom.

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Safer and efficient base editing and prime editing via ribonucleoproteins delivered through optimized lipid-nanoparticle formulations.

Nat Biomed Eng

November 2024

Gavin Herbert Eye Institute - Center for Translational Vision Research, Department of Ophthalmology, University of California, Irvine, CA, USA.

Delivering ribonucleoproteins (RNPs) for in vivo genome editing is safer than using viruses encoding for Cas9 and its respective guide RNA. However, transient RNP activity does not typically lead to optimal editing outcomes. Here we show that the efficiency of delivering RNPs can be enhanced by cell-penetrating peptides (covalently fused to the protein or as excipients) and that lipid nanoparticles (LNPs) encapsulating RNPs can be optimized for enhanced RNP stability, delivery efficiency and editing potency.

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