309 results match your criteria: "Paul Scherrer Institute PSI[Affiliation]"

While biomass burning (BB) is the largest source of fine particles in the atmosphere, the influence of relative humidity (RH) and photochemistry on BB secondary organic aerosol (BB-SOA) formation and aging remains poorly constrained. These effects need to be addressed to better capture and comprehend the evolution of BB-SOA in the atmosphere. Cresol (CHO) is used as a BB proxy to investigate these effects.

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Article Synopsis
  • The study examines how different manufacturing methods affect residual stresses in Dievar steel, comparing conventional ingot casting with selective laser melting (SLM) followed by hot rotary swaging.
  • Rotary swaging significantly improved microstructure and hardness, decreasing residual stresses in SLM components from -600 MPa in the core to -300 MPa post-treatment, while enhancing overall material properties.
  • The findings highlight the effectiveness of rotary swaging as a post-processing technique for optimizing mechanical performance and minimizing failure risks in additively manufactured steel.
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Biomass burning (BB) is a major source of aerosols and black carbon, thereby exerting an important impact on climate and air quality. Levoglucosan is the most well-recognized organic marker compound of BB and has been used to quantitatively assess BB's contribution to ambient aerosols. However, little is known about levoglucosan's evaporation under atmospheric conditions, primarily due to the uncertainty of its effective saturation vapor concentration (*) and its unknown activity coefficient (γ), in the complex BB emission matrix.

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Magnetite nanoparticles (MNPs) play an important role in geological and environmental systems because of their redox reactivity and ability to sequester a wide range of metals and metalloids. X-ray absorption spectroscopy conducted at metal and metalloid edges has suggested that the magnetite {111} faces of octahedrally shaped nanoparticles play a dominant role in the redox and sorption processes of these elements. However, studies directly probing the magnetite surfaces, especially in their fully solvated state, are scarce.

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Quantification of cavitating flows with neutron imaging.

Sci Rep

November 2024

School of Science & Technology, City, University of London, Northampton Square, London, EC1V 0HB, UK.

The current experimental investigation demonstrates the capability of neutron imaging to quantify cavitation, in terms of vapour content, within an orifice of an abruptly constricting geometry. The morphology of different cavitation regimes setting in was properly visualised owing to the high spatial resolution of 16 μm achieved, given the extensive field of view of 12.9 × 12.

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The upgrade of the Swiss Light Source, called SLS 2.0, necessitates comprehensive updates to all 18 user front ends. This upgrade is driven by the increased power of the synchrotron beam, reduced floor space, changing source points, new safety regulations and enhanced beam properties, including a brightness increase by up to a factor of 40.

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Many spectacular optical phenomena in animals are produced by reflective assemblies of guanine crystals. The crystals comprise planar H-bonded layers of π-stacked molecules with a high in-plane refractive index. By preferentially expressing the highly reflective π-stacked (100) crystal face and controlling its cross-sectional shape, organisms generate a diverse array of photonic superstructures.

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Macrolitter, especially macroplastics, (> 0.5 cm) negatively impact freshwater ecosystems, where they can be retained along lake shores, riverbanks, floodplains or bed sediments. Long-term and large-scale assessments of macrolitter on riverbanks and lake shores provide an understanding of litter abundance, composition, and origin in freshwater systems.

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The development of unified regenerative fuel cells (URFCs) necessitates an active and stable bifunctional oxygen electrocatalyst. The unique challenge of possessing high activity for both the oxygen reduction (ORR) and oxygen evolution (OER) reactions, while maintaining stability over a wide potential window impedes the design of bifunctional oxygen electrocatalysts. Herein, two design strategies are explored to optimize their performance.

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Ozone response to precursors changes in the Chengdu-Chongqing economic circle, China, from satellite and ground-based observations.

Sci Total Environ

November 2024

College of Environmental Sciences and Engineering, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871, China; Tianfu Yongxing Laboratory, Chengdu 610213, Sichuan, China. Electronic address:

Article Synopsis
  • Ozone pollution in the Chengdu-Chongqing Economic Circle has significantly increased by 2.26 μg/m³ from 2015 to 2023, with meteorological factors only contributing to 18% of this rise.
  • Research shows that the region transitions from a VOC-limited to a NOx-limited environment, primarily in urban areas, affecting how ozone levels respond to changes in emissions.
  • While NO and NOx emissions decreased significantly, VOC emissions have not shown a meaningful reduction, leading to a rise in ozone levels and underscoring the need for coordinated reductions in both pollutant types.
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Small-angle-scattering tensor tomography is a technique for studying anisotropic nanostructures of millimetre-sized samples in a volume-resolved manner. It requires the acquisition of data through repeated tomographic rotations about an axis which is subjected to a series of tilts. The tilt that can be achieved with a typical setup is geometrically constrained, which leads to limits in the set of directions from which the different parts of the reciprocal space map can be probed.

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Copper-exchanged zeolite omega (Cu-omega) is a potent material for the selective conversion of methane-to-methanol (MtM) via the oxygen looping approach. However, its performance exhibits substantial variation depending on the operational conditions. Under an isothermal temperature regime, Cu-omega demonstrates subdued activity below 230 °C, but experiences a remarkable increase in activity at 290 °C.

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The Open Databases Integration for Materials Design (OPTIMADE) application programming interface (API) empowers users with holistic access to a growing federation of databases, enhancing the accessibility and discoverability of materials and chemical data. Since the first release of the OPTIMADE specification (v1.0), the API has undergone significant development, leading to the v1.

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Article Synopsis
  • Latin American cities face serious air pollution challenges, with PM2.5 particulates posing significant risks to human health and ecosystems.
  • A year-long monitoring campaign in six major cities revealed notable differences in PM2.5 levels and sources, highlighting the contribution of traffic emissions, biomass burning, and secondary organic aerosols.
  • The study suggests enhanced methodologies for source attribution, emphasizing the need for a comprehensive approach to tackle air quality issues effectively.
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Background: Several research groups have explored the potential of scandium radionuclides for theragnostic applications due to their longer half-lives and equal or similar coordination chemistry between their diagnostic and therapeutic counterparts, as well as lutetium-177 and terbium-161, respectively. Unlike the gallium-68/lutetium-177 pair, which may show different in-vivo uptake patterns, the use of scandium radioisotopes promises consistent behaviour between diagnostic and therapeutic radiopeptides. An advantage of scandium's longer half-life over gallium-68 is the ability to study radiopeptide uptake over extended periods and its suitability for centralized production and distribution.

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Biopolymer-based functional materials are essential for reducing the carbon footprint and providing high-quality lightweight materials suitable for packaging and thermal insulation. Here, cellulose nanocrystals (CNCs) were efficiently upcycled from post-consumer cotton clothing by TEMPO-mediated oxidation and HCl hydrolysis with a yield of 62% and combined with wood cellulose nanofibrils (CNFs) to produce anisotropic foams by unidirectional freeze-casting followed by freeze drying (FD) or supercritical-drying (SCD). Unidirectional freeze-casting resulted in foams with aligned macropores irrespective of the drying method, but the particle packing in the foam wall was significantly affected by how the ice was removed.

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Alkynyl radicals and cations are crucial reactive intermediates in chemistry, but often evade direct detection. Herein, we report the direct observation of the phenylethynyl radical (CHCC˙) and its cation (CHCC), which are two of the most reactive intermediates in organic chemistry. The radical is generated pyrolysis of (bromoethynyl)benzene at temperatures above 1500 K and is characterized by photoion mass-selected threshold photoelectron spectroscopy (ms-TPES).

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Cubosomes functionalized with antibodies as a potential strategy for the treatment of HER2-positive breast cancer.

J Colloid Interface Sci

November 2024

Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland; Department of Materials, ETH Zurich, 8093 Zurich, Switzerland. Electronic address:

Breast cancers that overexpress human epidermal growth factor receptor 2 (HER2) have poor prognosis. Moreover, available chemotherapies cause numerous side effects due to poor selectivity. To advance more effective and safer therapies for HER2-positive breast cancer, we explored the fusion of drug delivery technology and immunotherapy.

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Toxicity of particulate matter (PM) depends on its sources, size and composition. We identified PM sources and determined their contribution to oxidative potential (OP) as a health proxy for PM exposure in an Alpine valley influenced by cement industry. PM filter sample chemical analysis and equivalent black carbon (eBC) were measured at an urban background site from November 2020 to November 2021.

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In helimagnetic metals, ac current-driven spin motions can generate emergent electric fields acting on conduction electrons, leading to emergent electromagnetic induction (EEMI). Recent experiments reveal the EEMI signal generally shows a strongly current-nonlinear response. In this study, we investigate the EEMI of TbSb, a short-period helimagnet.

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This work investigates the use of passive luminescence detectors to determine different types of averaged linear energy transfer (LET-) for the energies relevant to proton therapy. The experimental results are compared to reference values obtained from Monte Carlo simulations.Optically stimulated luminescence detectors (OSLDs), fluorescent nuclear track detectors (FNTDs), and two different groups of thermoluminescence detectors (TLDs) were irradiated at four different radiation qualities.

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Van-der-Waals magnetic materials can be exfoliated to realize ultrathin sheets or interfaces with highly controllable optical or spintronics responses. In majority, these are collinear ferro-, ferri-, or antiferromagnets, with a particular scarcity of lattice-incommensurate helimagnets of defined left- or right-handed rotation sense, or helicity. Here, we report polarized neutron scattering experiments on DyTe, whose layered structure has highly metallic tellurium layers separated by double-slabs of dysprosium square nets.

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Article Synopsis
  • * This commentary covers 24 different topics chosen by board members, focusing on innovations in radiochemistry and the initial human application of new radiopharmaceuticals.
  • * It showcases significant trends in the field, highlighting advancements and hot topics within radiochemistry and radiopharmacy research.
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On-surface synthesis has become a prominent method for growing low-dimensional carbon-based nanomaterials on metal surfaces. However, the necessity of decoupling organic nanostructures from metal substrates to exploit their properties requires either transfer methods or new strategies to perform reactions directly on inert surfaces. The use of on-surface light-induced reactions directly on semiconductor/insulating surfaces represents an alternative approach to address these challenges.

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Oral malignancies continue to have severe morbidity with less than 50% long-term survival despite the advancement in the available therapies. There is a persisting demand for new approaches to establish more efficient strategies for their treatment. In this regard, the human topoisomerase II (topoII) enzyme is a validated chemotherapeutics target, as topoII regulates vital cellular processes such as DNA replication, transcription, recombination, and chromosome segregation in cells.

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