6,544 results match your criteria total scattering

Formation and growth mechanism for niobium oxide nanoparticles: atomistic insight from in situ X-ray total scattering.

Nanoscale 2021 May 23;13(17):8087-8097. Epub 2021 Mar 23.

Department of Chemistry and Nano-Science Center, University of Copenhagen, 2100 Copenhagen Ø, Denmark.

Understanding the mechanisms for nanoparticle nucleation and growth is crucial for the development of tailormade nanomaterials. Here, we use X-ray total scattering and Pair Distribution Function analysis to follow the formation and growth of niobium oxide nanoparticles. We study the solvothermal synthesis from niobium chloride in benzyl alcohol, and through investigations of the influence of reaction temperature, a formation pathway can be suggested. Read More

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Structural evolution in thermoelectric zinc antimonide thin films studied by X-ray scattering techniques.

IUCrJ 2021 May 13;8(Pt 3):444-454. Epub 2021 Apr 13.

Center for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Aarhus C, DK-8000, Denmark.

Zinc antimonides have been widely studied owing to their outstanding thermoelectric properties. Unlike in the bulk state, where various structurally unknown phases have been identified through their specific physical properties, a number of intermediate phases in the thin-film state remain largely unexplored. Here, X-ray diffraction and X-ray total scattering are combined with measurement of electrical resistivity to monitor the crystallization process of as-deposited amorphous Zn-Sb films during post-deposition annealing. Read More

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Synchrotron total-scattering data applicable to dual-space structural analysis.

IUCrJ 2021 May 6;8(Pt 3):387-394. Epub 2021 Mar 6.

Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C, 8000, Denmark.

Synchrotron powder X-ray diffraction (PXRD) is a well established technique for investigating the atomic arrangement of crystalline materials. At modern beamlines, X-ray scattering data can be collected in a total-scattering setting, which additionally opens up the opportunity for direct-space structural analysis through the atomic pair distribution function (PDF). Modelling of PXRD and PDF data is typically carried out separately, but employing a concurrent structural model to both direct- and reciprocal-space data has the possibility to enhance total-scattering data analysis. Read More

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Comparison and evaluation of pair distribution functions, using a similarity measure based on cross-correlation functions.

J Appl Crystallogr 2021 Apr 31;54(Pt 2):612-623. Epub 2021 Mar 31.

Institute of Inorganic and Analytical Chemistry, Goethe University, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany.

An approach for the comparison of pair distribution functions (PDFs) has been developed using a similarity measure based on cross-correlation functions. The PDF is very sensitive to changes in the local structure, small deviations in the structure can cause large signal shifts and significant discrepancies between the PDFs. Therefore, a comparison based on pointwise differences ( values and difference curves) may lead to the assumption that the investigated PDFs as well as the corresponding structural models are not in agreement at all, whereas a careful visual inspection of the investigated structural models and corresponding PDFs may reveal a relatively good match. Read More

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Temperature-gradient analyzers for non-resonant inelastic X-ray scattering.

J Synchrotron Radiat 2021 May 19;28(Pt 3):756-768. Epub 2021 Mar 19.

Materials Dynamics Laboratory, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.

The detailed fabrication and performance of the temperature-gradient analyzers that were simulated by Ishikawa & Baron [(2010). J. Synchrotron Rad. Read More

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Spatially co-registered wide-field nonlinear optical imaging of living and complex biosystems in a total internal reflection geometry.

Analyst 2021 May;146(9):3062-3072

Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.

Nonlinear optical microscopy that leverages an objective based total internal reflection (TIR) excitation scheme is an attractive means for rapid, wide-field imaging with enhanced surface sensitivity. Through select combinations of distinct modalities, one can, in principle, access complementary chemical and structural information for various chemical species near interfaces. Here, we report a successful implementation of such a wide-field nonlinear optical microscope system, which combines coherent anti-Stokes Raman scattering (CARS), two-photon fluorescence (TPF), second harmonic generation (SHG), and sum frequency generation (SFG) modalities on the same platform. Read More

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Effect of Fluorescent Labels on DNA Affinity for Gold Nanoparticles.

Nanomaterials (Basel) 2021 Apr 29;11(5). Epub 2021 Apr 29.

Institute of Chemical Biology and Fundamental Medicine, SB RAS, Lavrentiev ave. 8, 630090 Novosibirsk, Russia.

Fluorophore (FD) labeling is widely used for detection and quantification of various compounds bound to nanocarriers. The systems, composed of gold nanoparticles (GNPs) and oligonucleotides (ONs) labeled with FDs, have wide applications. Our work was aimed at a systemic study of how FD structure (in composition of ON-FDs) influenced the efficiency of their non-covalent associates' formation with GNPs (ON-FD/GNPs). Read More

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Preservation of the Antioxidant Capacity of Resveratrol via Encapsulation in Niosomes.

Foods 2021 Apr 30;10(5). Epub 2021 Apr 30.

Facultad de Ciencias Químicas, Departamento de Química Orgánica, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba X5000HUA, Argentina.

Resveratrol (RSV) is a natural polyphenol which produces several benefits to human health, being the isomer the most bioactive. However, its systemic absorption is limited due to its low water solubility, that reduces the oral bioavailability, and its chemical instability (owing to the - RSV isomer conversion upon light irradiation). Thus, encapsulation of this bioactive compound is required to protect it from destructive environmental conditions. Read More

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Evolution of the Local Structure in the Sol-Gel Synthesis of FeC Nanostructures.

Inorg Chem 2021 May 4. Epub 2021 May 4.

School of Chemistry, University of Birmingham, Birmingham B152TT, U.K.

The sol-gel synthesis of iron carbide (FeC) nanoparticles proceeds through multiple intermediate crystalline phases, including iron oxide (FeO) and iron nitride (FeN). The control of particle size is challenging, and most methods produce polydisperse FeC nanoparticles of 20-100 nm in diameter. Given the wide range of applications of FeC nanoparticles, it is essential that we understand the evolution of the system during the synthesis. Read More

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Investigation of the Scaling Formula Accuracy for Poly-energetic Kernel Calculation in 6 MV Photon Beam.

J Biomed Phys Eng 2021 Apr 1;11(2):135-142. Epub 2021 Apr 1.

PhD Candidate, Department of Medical Physics, Isfahan University of Medical Sciences, Isfahan, Iran.

Background: Dose distribution can be obtained from total energy released per unit mass (TERMA) and inhomogeneous energy deposition kernel (EDK) convolution. Since inhomogeneous EDK data is location-dependent, it is calculated by employing the density scaling method rather than Monte Carlo based user code EDKnrc.

Objective: The present study aimed at investigating EDK scaling formula accuracy in the presence of lung and bone inhomogeneities. Read More

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Ultraviolet Luminescence of ZnO Whiskers, Nanowalls, Multipods, and Ceramics as Potential Materials for Fast Scintillators.

Materials (Basel) 2021 Apr 16;14(8). Epub 2021 Apr 16.

Federal Scientific Research Centre "Crystallography and Photonics" of Russian Academy of Sciences, Shubnikov Institute of Crystallography, 119333 Moscow, Russia.

The presented work is dedicated to the study and comparison of scintillating properties of zinc oxide samples prepared in different morphologies: whiskers, nanowalls, multipods, and ceramics. It was shown that total transmittance, photo- and radioluminescence spectra, and radioluminescence kinetics can vary significantly depending on sample structure and preparation conditions. The highest total transmittance was registered for ZnO ceramics (>50% at 0. Read More

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Review of the Newly Developed, Mobile Optical Sensors for Real-Time Measurement of the Atmospheric Particulate Matter Concentration.

Micromachines (Basel) 2021 Apr 9;12(4). Epub 2021 Apr 9.

Department of Electrical and Information Engineering, Polytechnic University of Bari, 70125 Bari, Italy.

Due to the adverse effects on human health and the environment, air quality monitoring, specifically particulate matter (PM), has received increased attention over the last decades. Most of the research and policy actions have been focused on decreasing PM pollution and the development of air monitoring technologies, resulting in a decline of total ambient PM concentrations. For these reasons, there is a continually increasing interest in mobile, low-cost, and real-time PM detection instruments in both indoor and outdoor environments. Read More

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Long-Term Stability of Different Kinds of Gas Nanobubbles in Deionized and Salt Water.

Materials (Basel) 2021 Apr 6;14(7). Epub 2021 Apr 6.

College of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.

Nanobubbles have many potential applications depending on their types. The long-term stability of different gas nanobubbles is necessary to be studied considering their applications. In the present study, five kinds of nanobubbles (N, O, Ar + 8%H, air and CO) in deionized water and a salt aqueous solution were prepared by the hydrodynamic cavitation method. Read More

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The Importance of Free Fatty Chain Length on the Lipid Organization in the Long Periodicity Phase.

Int J Mol Sci 2021 Apr 1;22(7). Epub 2021 Apr 1.

Division of BioTherapeutics, Leiden Academic Centre for Drug Research, University of Leiden, 2311 EZ Leiden, The Netherlands.

The skin's barrier ability is an essential function for terrestrial survival, which is controlled by intercellular lipids within the stratum corneum (SC) layer. In this barrier, free fatty acids (FFAs) are an important lipid class. As seen in inflammatory skin diseases, when the lipid chain length is reduced, a reduction in the barrier's performance is observed. Read More

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Thermal neutron cross sections of amino acids from average contributions of functional groups.

J Phys Condens Matter 2021 Apr 27. Epub 2021 Apr 27.

Universita di Roma 'Tor Vergata', via della Ricerca Scientifica 1, I-00133 Roma, Roma, 00133, ITALY.

The experimental thermal neutron cross sections of the twenty proteinogenic amino acids have been measured over the incident-neutron energy range spanning from 1 meV to 10 keV and data have been interpreted using the multi-phonon expansion based on first-principles calculations. The scattering cross section, dominated by the incoherent inelastic contribution from the hydrogen atoms, can be rationalised in terms of the average contributions of different functional groups, thus neglecting their correlation. These results can be used for modelling the total neutron cross sections of complex organic systems like proteins, muscles, or human tissues from a limited number of starting input functions. Read More

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Palladium Nanoparticle-Induced Oxidative Stress, Endoplasmic Reticulum Stress, Apoptosis, and Immunomodulation Enhance the Biogenesis and Release of Exosome in Human Leukemia Monocytic Cells (THP-1).

Int J Nanomedicine 2021 15;16:2849-2877. Epub 2021 Apr 15.

Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Seoul, Korea.

Background: Exosomes are endosome-derived nano-sized vesicles that have emerged as important mediators of intercellular communication and play significant roles in various diseases. However, their applications are rigorously restricted by the limited secretion competence of cells. Therefore, strategies to enhance the production and functions of exosomes are warranted. Read More

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Modulation of Nanoparticle Diffusion by Surface Ligand Length and Charge: Analysis with Molecular Dynamics Simulations.

J Phys Chem B 2021 May 21;125(17):4555-4565. Epub 2021 Apr 21.

Departments of Chemistry, Physics, and Biomedical Engineering, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States.

To help better interpret experimental measurement of nanoparticle size, it is important to understand how their diffusion depends on the physical and chemical features of surface ligands. In this study, explicit solvent molecular dynamics simulations are used to probe the effect of ligand charge and flexibility on the diffusion of small gold nanoparticles. The results suggest that despite a high bare charge (+18 ), cationic nanoparticles studied here have reduced diffusion constants compared to a hydrophobic gold nanoparticle by merely a modest amount. Read More

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Microfluidic device coupled with total internal reflection microscopy for in situ observation of precipitation.

Eur Phys J E Soft Matter 2021 Apr 20;44(4):57. Epub 2021 Apr 20.

Department of Chemical and Materials Engineering, University of Alberta, Alberta, T6G 1H9, Canada.

In situ observation of precipitation or phase separation induced by solvent addition is important in studying its dynamics. Combined with optical and fluorescence microscopy, microfluidic devices have been leveraged in studying the phase separation in various materials including biominerals, nanoparticles, and inorganic crystals. However, strong scattering from the subphases in the mixture is problematic for in situ study of phase separation with high temporal and spatial resolution. Read More

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Structures and Role of the Intermediate Phases on the Crystallization of BaTiO from an Aqueous Synthesis Route.

ACS Omega 2021 Apr 30;6(14):9567-9576. Epub 2021 Mar 30.

Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Trondheim 7491, Norway.

Carbonate formation is a prevailing challenge in synthesis of BaTiO, especially through wet chemical synthesis routes. In this work, we report the phase evolution during thermal annealing of an aqueous BaTiO precursor solution, with a particular focus on the structures and role of intermediate phases forming prior to BaTiO nucleation. infrared spectroscopy, X-ray total scattering, and transmission electron microscopy were used to reveal the decomposition, pyrolysis, and crystallization reactions occurring during thermal processing. Read More

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Intermediate scattering functions of a rigid body monoclonal antibody protein in solution studied by dissipative particle dynamic simulation.

Struct Dyn 2021 Mar 8;8(2):024102. Epub 2021 Apr 8.

NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA.

In the past decade, there was increased research interest in studying internal motions of flexible proteins in solution using Neutron Spin Echo (NSE) as NSE can simultaneously probe the dynamics at the length and time scales comparable to protein domain motions. However, the collective intermediate scattering function (ISF) measured by NSE has the contributions from translational, rotational, and internal motions, which are rather complicated to be separated. Widely used NSE theories to interpret experimental data usually assume that the translational and rotational motions of a rigid particle are decoupled and independent to each other. Read More

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Study on surface enhanced Raman scattering of Au and Au@AlO spherical dimers based on 3D finite element method.

Sci Rep 2021 Apr 16;11(1):8391. Epub 2021 Apr 16.

College of Information Science and Engineering, Yanshan University, Qinhuangdao, 066004, China.

In this paper, the surface enhanced Raman scattering (SERS) characteristics of Au and Au@AlO nanoparticle dimers were calculated and analyzed by using finite element method (3D-FEM). Firstly, the electric field enhancement factors of Au nanoparticles at the dimer gap were optimized from three aspects: the incident angle of the incident light, the radius of nanoparticle and the distance of the dimer. Then, aluminum oxide is wrapped on the Au dimer. Read More

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Elemental mapping of labelled biological specimens at intermediate energy loss in an energy-filtered TEM acquired using a direct detection device.

J Microsc 2021 Apr 12. Epub 2021 Apr 12.

Department of Pharmacology, University of California, San Diego, La Jolla, California, USA.

The technique of colour EM that was recently developed enabled localisation of specific macromolecules/proteins of interest by the targeted deposition of diaminobenzidine (DAB) conjugated to lanthanide chelates. By acquiring lanthanide elemental maps by energy-filtered transmission electron microscopy (EFTEM) and overlaying them in pseudo-colour over the conventional greyscale TEM image, a colour EM image is generated. This provides a powerful tool for visualising subcellular component/s, by the ability to clearly distinguish them from the general staining of the endogenous cellular material. Read More

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Wintertime chemical characteristics of aerosol and their role in light extinction during clear and polluted days in rural Indo Gangetic plain.

Environ Pollut 2021 Mar 30;282:117034. Epub 2021 Mar 30.

Ullens Education Foundation, Lalitpur, Nepal; International Centre for Integrated Mountain Development (ICIMOD), Khumaltar, Lalitpur, Nepal.

This paper reports the chemical and light extinction characteristics of fine aerosol (PM) during the winter period (2017-18) at Lumbini, Nepal, a rural site on the Indo Gangetic Plains. A modified IMPROVE algorithm was employed to reconstruct light extinction by chemical constituents of aerosol. The fine aerosol levels impacted visibility adversely during daytime, but during nighttime visibility was controlled by fog droplets rather than by aerosols. Read More

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Chemometric pre-processing can negatively affect the performance of near-infrared spectroscopy models for fruit quality prediction.

Talanta 2021 Jul 11;229:122303. Epub 2021 Mar 11.

Farm Technology Group, Wageningen University & Research, Wageningen, the Netherlands.

Chemometrics pre-processing of spectral data is widely performed to enhance the predictive performance of near-infrared (NIR) models related to fresh fruit quality. Pre-processing approaches in the domain of NIR data analysis are used to remove the scattering effects, thus, enhancing the absorption components related to the chemical properties. However, in the case of fresh fruit, both the scattering and absorption properties are of key interest as they jointly explain the physicochemical state of a fruit. Read More

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A staggered 3-layer DOI PET detector using BaSOreflector for enhanced crystal identification and inter-crystal scattering event discrimination capability.

Biomed Phys Eng Express 2021 Apr 28;7(3). Epub 2021 Apr 28.

Institute for Quantum Medical Science, National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1, Anagawa, Inage-ku, Chiba, Japan.

The spatial resolution of small animal positron emission tomography (PET) scanners can be improved by the use of crystals with fine pitch and rejection of inter-crystal scattering (ICS) events, which leads to a better quantification of radiopharmaceuticals. On the other hand, depth-of-interaction (DOI) information is essential to preserve the spatial resolution at the PET field-of-view (FOV) periphery while keeping the sensitivity. In this study we proposed a novel staggered 3-layer DOI detector using BaSOreflector material for an enhanced crystal identification performance as well as ICS event rejection capability over those of ESR reflector based DOI detectors. Read More

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Illustrated formalisms for total scattering data: a guide for new practitioners.

J Appl Crystallogr 2021 Feb 1;54(Pt 1):317-332. Epub 2021 Feb 1.

Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.

The total scattering method is the simultaneous study of both the real- and reciprocal-space representations of diffraction data. While conventional Bragg-scattering analysis (employing methods such as Rietveld refinement) provides insight into the average structure of the material, pair distribution function (PDF) analysis allows for a more focused study of the local atomic arrangement of a material. Generically speaking, a PDF is generated by Fourier transforming the total measured reciprocal-space diffraction data (Bragg and diffuse) into a real-space representation. Read More

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February 2021

[Ga]Ga-iPSMA-Lys-Bombesin: Biokinetics, dosimetry and first patient PET/CT imaging.

Nucl Med Biol 2021 Mar 27;96-97:54-60. Epub 2021 Mar 27.

Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico State, Mexico. Electronic address:

Background: The prostate-specific membrane antigen (PSMA) and the gastrin-releasing peptide receptor (GRPR) are overexpressed in prostate cancer (PCa). In preclinical studies, the iPSMA-Lys-Bombesin (iPSMA-BN) heterodimeric ligand has shown a suitable affinity for PSMA and GRPR. This research aimed to assess the biokinetics and radiation dosimetry of [Ga]Ga-iPSMA-BN in four healthy volunteers based on biodistribution data obtained from whole-body PET/CT studies, as well as to visualize the [Ga]Ga-iPSMA-BN tumor uptake in a patient with PCa. Read More

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Magnetic Ordering in the Ising Antiferromagnetic Pyrochlore NdScNbO.

J Phys Condens Matter 2021 Apr 7. Epub 2021 Apr 7.

University of Winnipeg, 599 Portage Ave, Winnipeg, Manitoba, R3B 2E9, CANADA.

The question of structural disorder and its effects on magnetism is relevant to a number of spin liquid candidate materials. Although commonly thought of as a route to spin glass behaviour, here we describe a system in which the structural disorder results in long-range antiferromagnetic order due to local symmetry breaking. NdScNbOis shown to have a dispersionless gapped excitation observed in other neodymium pyrochlores below T=0. Read More

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Selective removal of over-paintings from "Street Art" using an environmentally friendly nanostructured fluid loaded in highly retentive hydrogels.

J Colloid Interface Sci 2021 Aug 26;595:187-201. Epub 2021 Mar 26.

CSGI, Center for Colloids and Surface Science, University of Florence, via della Lastruccia, 3, 50019, Sesto Fiorentino, FI, Italy. Electronic address:

Hypothesis: The removal of over-paintings or graffiti is a priority for conservators and restorers. This operation is complex, especially when over-paintings lay on painted surfaces that must be preserved, as in the case of vandalism on street art, where the layers are usually chemically similar. Traditional methodologies often do not provide satisfactory results and pose health and eco-compatibility concerns. Read More

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Microcalcification-Based Tumor Malignancy Evaluation in Fresh Breast Biopsies with Hyperspectral Stimulated Raman Scattering.

Anal Chem 2021 04 7;93(15):6223-6231. Epub 2021 Apr 7.

State Key Laboratory of Surface Physics and Department of Physics, Human Phenome Institute, Multiscale Research Institute of Complex Systems, Academy for Engineering and Technology, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Fudan University, Shanghai 200433, China.

Precise evaluation of breast tumor malignancy based on tissue calcifications has important practical value in the disease diagnosis, as well as the understanding of tumor development. Traditional X-ray mammography provides the overall morphologies of the calcifications but lacks intrinsic chemical information. In contrast, spontaneous Raman spectroscopy offers detailed chemical analysis but lacks the spatial profiles. Read More

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