10,263 results match your criteria: "Institute of Physical Chemistry[Affiliation]"

The microvascular bed plays a crucial role in establishing nutrient exchange and waste removal, as well as maintaining tissue metabolic activity in the human body. However, achieving microvascularization of engineered 3D tissue constructs is still an unsolved challenge. In this work, we developed biomimetic cell-laden hydrogel microfibers recapitulating oriented microvascular capillary-like networks by using a 3D bioprinting technique combined with microfluidics-assisted coaxial wet-spinning.

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The molecular structure of a ferrocene derivative with adjacent centers of chirality, 1,1'-bis(tert-butylphosphino)ferrocene, has been examined in the gas phase using broadband microwave spectroscopy under the isolated and cold conditions of a supersonic jet. The diastereomers of 1,1'-bis(tert-butylphosphino)ferrocene can adopt homo- and hetero-chiral configurations, owing to the P-chiral substituents on the cyclopentadienyl rings. Moreover, the internal ring rotation of each diastereomer gives rise to four conformers with eclipsed ring arrangements, where the two tert-butylphosphino groups were separated by dihedral angles of approximately 72°, 144°, 216°, and 288° with respect to the two ring centers.

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Due to their ultra-high sensitivity, solution-gated graphene-based field-effect transistors (SG-GFET) have been proposed for applications in bio-sensing. However, challenges regarding the functionalization of GFETs have prevented their applications in clinical diagnostics so far. Here GFET sensors based on van der Waals (vdW) heterostructures of single-layer graphene layered with a molecular ≈1 nm thick carbon nanomembrane (CNM) are presented.

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Prolonged starvation leads to acute stress, inducing a state of cellular dormancy with reduced energy consumption. Our research reveals that nutrient deprivation halts the movement of large ribosomal subunits, trapping them in a gel-like structure within the cytoplasm of surviving cells. This effect is due to water efflux from cells, causing a decrease in cell volume to half the original volume.

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Article Synopsis
  • Antimicrobial resistance (AMR) in Enterobacterales, particularly in Escherichia coli, poses serious health and economic issues for humans and animals, highlighting the "One Health" approach to understanding this problem.
  • The study aimed to find extended-spectrum cephalosporin-resistant Enterobacterales in ruminants across Rwanda's provinces and to characterize the isolates.
  • From 454 rectal swabs collected from cattle, goats, and sheep, 64 resistant isolates were found, predominantly E. coli, with many showing multidrug-resistance and various resistance phenotypes linked to specific genes.
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A paraffin droplet containing camphor and oil red O (dye) floating on the water surface shows spontaneous motion and deformation generated by the surface tension gradient around the droplet. We focused on the intermittent motion with a pronounced deformation into a crescent shape observed at specific concentrations of camphor and oil red O. We quantitatively analyzed the time changes in the droplet deformation and investigated the role of the oil red O by measuring the time-dependent paraffin-water interfacial tension with the pendant drop method.

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Silica materials, natural and synthetic variants, represent a promising material for the application in heterogeneous organocatalysis due to their readily modifiable surface and chemical inertness. To achieve high catalyst loadings, usually, porous carriers with high surface areas are used, such as silica monoliths or spherical particles for packed bed reactors. While these commercial materials were shown to be efficient supports, their synthesis is elaborate, and thus less complex and cheaper alternatives are of interest, especially considering scaling up for potential applications.

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Enhancing prediction stability and performance in LIBS analysis using custom CNN architectures.

Talanta

March 2025

Leibniz Institute of Photonics Technology, Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research (LPI), Albert-Einstein-Strasse 9, 07745, Jena, Germany; Institute of Physical Chemistry (IPC) and Abbe Centre of Photonics (ACP), Friedrich Schiller University Jena, Member of the Leibniz Centre for Photonics (LPI), Helmholtzweg4, 07743, Jena, Germany; Former Institution: Institute of Computer Science, Faculty of Mathematics, Physics & Computer Science, University of Bayreuth Universitaetsstraße 30, 95447, Bayreuth, Germany. Electronic address:

Article Synopsis
  • * Two predictive modeling methods, Partial Least Squares (PLS) and Convolutional Neural Networks (CNNs), are utilized to estimate concentrations of 24 elements in LIBS spectra, with CNNs demonstrating superior predictive accuracy and stability compared to PLS.
  • * The study progresses through three phases, ultimately fine-tuning CNN models to focus on specific elements and yielding notable predictions for Aluminum, Silicon, Iron, and others, while exploring the effects of changing model training parameters.
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Article Synopsis
  • * The article introduces "elimination voltammetry with a linear scan" (EVLS) as a software approach to overcome limitations like low sensitivity and signal overlap, allowing selective elimination of certain current components based on scan rates.
  • * EVLS shows promise for enhancing the understanding of electrochemical processes, particularly in scenarios involving irreversible electrode processes, by selectively preserving key current components while eliminating others for more accurate analysis.
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Importance of Electron Correlation on the Geometry and Electronic Structure of [2Fe-2S] Systems: A Benchmark Study of the [FeS(SCH)], [FeS(SCys)], [FeS(S--tol)], and [FeS(S--xyl)] Complexes.

J Chem Theory Comput

December 2024

Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, P.O. Box 999, MS J7-10, Richland, Washington 99352, United States.

Iron-sulfur clusters are crucial for biological electron transport and catalysis. Obtaining accurate geometries, energetics, manifolds of their excited electronic states, and reduction energies is important to understand their role in these processes. Using a [2Fe-2S] model complex with Fe and Fe oxidation states, which leads to different charges, i.

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Si-based anodes can increase specific energy and energy density of Li ion batteries. However, the volume-induced material stress and capacity loss necessitates only a partial Si utilization within composite anodes, typically with state-of-the-art graphite, so called Si/Gr composites. In this work, various Si nanowires (SiNWs), a promising Si architecture for these composites, are investigated and modified via pre-lithiation.

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We present the spontaneous isomerization of donor-acceptor Stenhouse adducts anchored onto a gold surface, visualized using scanning tunneling spectroscopy. Our investigation reveals a palette of molecular arrangements, including those with ferroelectric-like ordering, evolving over time into a fine pattern consisting of both open and closed forms of the photoswitch.

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Although metal halide perovskites are positioned as the most powerful light-harvesting materials for sustainable energy conversion, there is a need for a thorough understanding of molecular design principles that would guide better engineering of organic hole-transporting materials, which are vital for boosting the performance and stability of perovskite solar cells. To address this formidable challenge, here, we developed a new design strategy based on the curved N-doped polycyclic aromatic hydrocarbon merged with T-shaped phenazines being decorated with (phenyl)-di--methoxyphenylamine (OMeTAD)─N-PAH23/24 and -3,6-ditertbutyl carbazole (TBCz)─N-PAH25/26. As N-PAH23/24 exhibited satisfying thermal stability, the comparative studies performed with various experimental and simulation methods revealed a pronounced correlation between the depth of the central cyclazine core and the form of the T-shape units.

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Orthogonal Functionalization of Oxo-Graphene Nanoribbons.

Chemistry

January 2025

Institute of Chemistry and Biochemistry, Freie Universität Berlin, Altensteinstraße 23a, 14195, Berlin, Germany.

Article Synopsis
  • Oxo-graphene nanoribbons (oxo-GNRs) are created by cutting single-walled carbon nanotubes through an oxidative process.
  • An orthogonal functionalization method is introduced that allows for modifications on both the edges and the flat surface of oxo-GNRs due to their unique structure.
  • This functionalization technique, which was tracked using X-ray photoelectron spectroscopy, can also be adapted for other oxo-functionalized carbon materials like graphene quantum dots and reduced graphene oxide.
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The Identity algorithm implemented in the MS Search (NIST) software is widely used for library searches of gas chromatography/mass spectrometry data against electron ionization mass spectral databases. It has been available to researchers since 1993, with the release of MS Search 1.5a.

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Herein, we present a paper that attempts to bridge the gap between CO oxidation catalytic tests performed in a model stream and a more realistic exhaust gas stream by incorporating characterization methods that allow for active probing of the catalyst surface. The results have shown that it is not just the abundance of a given type of species on the surface that impacts the activity of a system but also the ease of extraction of ions from their surface (time-of-flight secondary ion mass spectrometry) and the response of the support to change in the feed composition (dynamic in situ X-ray diffraction (XRD) with variable atmosphere). The study utilizes the method of doping a catalyst (RuO/CZ) with a small amount of alkali-metal (K or Na) carbonates in order to slightly modify its surface to gain insight into parameters that may cause discrepancies between model stream activity and complex stream activity.

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We show that strong molecular rotation drastically modifies the autodetachment of C_{2}^{-} ions in the lowest quartet electronic state a^{4}Σ_{u}^{+}. In the strong-rotation regime, levels of this state only decay by a process termed "rotationally assisted" autodetachment, whose theoretical description is worked out based on the nonlocal resonance model. For autodetachment linked with the exchange of six rotational quanta, the results reproduce a prominent, hitherto unexplained electron emission signal with a mean decay time near 3 ms, observed on stored C_{2}^{-} ions from a hot ion source.

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Force-Assisted Orbital Crossing in Mechanochemical Oxirane Ring Opening.

J Phys Chem A

November 2024

Institute of Physical Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.

Polymer mechanochemistry induces chemical reactivity by applying a directed force, which can lead to unexpected reaction mechanisms. Strained cyclic molecules are often used in force-sensitive motifs because of the strong force coupling of ring-opening reactions. In this computational study, the force dependence of the ring-opening reactions of oxirane will be investigated.

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Heterogenous Chemistry of IO as a Critical Step in Iodine Cycling.

J Am Chem Soc

December 2024

Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.

Global iodine emissions have been increasing rapidly in recent decades, further influencing the Earth's climate and human health. However, our incomplete understanding of the iodine chemical cycle, especially the fate of higher iodine oxides, introduces substantial uncertainties into atmospheric modeling. IO was previously deemed a "dead end" in iodine chemistry; however, we provide atomic-level evidence that IO can undergo rapid air-water or air-ice interfacial reactions within several picoseconds; these reactions are facilitated by prevalent chemicals on seawater such as amines and halide ions, to produce photolabile reactive iodine species such as HOI and IX (X = I, Br, and Cl).

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Here, we present for the first time an efficient platform for simultaneous H generation and CO conversion into HCOOH, utilizing a Cu-incorporated NH-MIL-125(Ti) material with triethanolamine as the sacrificial agent. When subjected to light, Cu-NH-MIL-125(Ti) exhibits a remarkable enhancement in H generation, with a 30-fold increase under UV-Vis light and an 8-fold increase under visible irradiation compared to the pristine MOF. The study on the CO photoreduction ability of Cu-NH-MIL-125(Ti) indicated successful conversion into formic acid yielding 62.

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Nucleoproteins (N) play an essential role in virus assembly and are less prone to mutation than other viral structural proteins, making them attractive targets for drug discovery. Using an NMR fragment-based drug discovery approach, we identified the 1,3-benzothiazol-2-amine (BZT) group as a scaffold to develop potential antivirals for SARS-CoV-2 nucleocapsid (N) protein. A thorough characterization of BZT derivatives using NMR, X-ray crystallography, antiviral activity assays, and intrinsic fluorescence measurements revealed their binding in the C-terminal domain (CTD) domain of the N protein, to residues Arg 259, Trp 330, and Lys 338, coinciding with the nucleotide binding site.

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p-NiO/n-GaO heterojunction (HJ) diodes exhibit much larger changes in their properties upon 1.1 MeV proton irradiation than Schottky diodes (SDs) prepared on the same material. In p-NiO/GaO HJ diodes, the narrow region adjacent to the HJ boundary is found to contain a high density of relatively deep centers with levels near E-0.

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In the transition to zero waste and sustainable development, it becomes essential to use phase change materials and recycled cement in construction projects to improve energy efficiency and encourage sustainable building practices. The primary goal of this study is to determine how the properties of expanded perlite mortars are affected when Portland cement is partially replaced with recycled cement, produced by thermally treating concrete waste at 550 °C. Recycled cement substituted Portland cement in various percentages (10 %, 30 %, and 50 %).

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Modifying d-p orbital hybridization of Ni/FeO species by high-valence ruthenium doping to enhance oxygen evolution performance.

J Colloid Interface Sci

February 2025

Institute of Physical Chemistry, College of Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130021, China. Electronic address:

The electron distribution of catalysts can be modulated by high-valence metal doping, thus enhancing the intrinsic activity. Herein, we adopt Ru modification to adjust the d-p orbital hybridization of Ni-Fe oxyhydroxides, significantly increasing the oxygen evolution reaction (OER) activity. The amorphous NiFeRuOH catalyst synthesized by sol-gel method exhibits excellent OER activity, far superior to commercial RuO.

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Photodesorption of CO ices: Rotational and translational energy distributions.

J Chem Phys

November 2024

CNRS, De la Molécule aux Nano-Objets: Réactivité, Interactions et Spectroscopies, MONARIS, Sorbonne Université, 75005 Paris, France.

This study investigates the translational and rovibrational energy of vacuum-ultraviolet (VUV) photodesorbed CO molecules from a CO polycrystalline ice (15 K) at ∼8 eV. The electronic excitation was produced by a pulsed VUV laser, and the photodesorption of CO molecules in their ground and first vibrational states was observed using resonance enhanced multiphoton ionization. Time-of-flight and rotationally resolved spectra were measured, and the kinetic and internal energy distribution were obtained.

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