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Characterization of dextran particle size: How frit-inlet asymmetrical flow field-flow fractionation (FI-AF4) coupled online with dynamic light scattering (DLS) leads to enhanced size distribution.

J Chromatogr A 2021 Jul 24;1653:462404. Epub 2021 Jul 24.

Normandie University, UNIROUEN, National Institute of Applied Sciences of Rouen, CNRS, PBS, UMR6270, Rouen 76000, France. Electronic address:

Accurate determinations of particle size and particle size distribution (PSD) are essential to achieve the clinical translation of medical nanoparticles (NPs). Herein, dextran-based NPs produced via a water-in-oil emulsification/crosslinking process and developed as nanomedicines were studied. NPs were first characterized using traditional batch-mode techniques as dynamic light scattering (DLS) and laser diffraction. Read More

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Self-assembled micelles of the (lipo) glycopeptides, teicoplanin, as taxane nanocarriers.

Nanotechnology 2021 Jul 30. Epub 2021 Jul 30.

Centro de Excelencia en Productos y Procesos Cordoba, Pabellon Ceprocor. Santa Maria de Punilla, Cordoba, 5004, ARGENTINA.

The use of nanoparticles is one of the strategies currently studied to minimize the toxicity and lack of tissue specificity of many cancer drugs used in chemotherapy. In this research the physicochemical and biological behavior of a novel self-assembled nanostructure of the antibiotic Teicoplanin (Teico) was characterized as a nanocarrier system for solubilizing highly hydrophobic drugs like Paclitaxel (Ptx) in aqueous media. The Teico micelles were loaded with Ptx in DMSO or PEG-400. Read More

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Statistical Mueller matrix driven discrimination of suspended particles.

Opt Lett 2021 Aug;46(15):3645-3648

An effective method to calculate the statistical Mueller matrix (SMM) of suspended particles based on polarized light scattering is presented that takes advantage of the Stokes vectors measurement of individual particles. The calculation method of the SMM is derived based on statistics. Experimental results of Microcystis samples confirm that the SMM can characterize cells of different states. Read More

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essential oil: an active principle of nanoemulsion against root canal biofilm.

Future Microbiol 2021 Aug 28;16:907-918. Epub 2021 Jul 28.

School of Dental Medicine, University of Belgrade, dr Subotića 8, Belgrade, 11000, Serbia.

The objective was to formulate and characterize the nanoemulsion based on oil, intended for use in infected teeth root canal therapy. The investigation of the antioxidant and antibiofilm potential toward was aimed as well. Characterization of oil (by GC/MS analysis) and nanoemulsion (by dynamic light scattering instrument), and determination of antibacterial (by microdilution assay), antibiofilm (by crystal violet assay) and antioxidant properties (by 2,2-diphenyl-1-picryl-hydrazyl-hydrate and thiobarbituric acid assay methods) were provided. Read More

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Importance of methylammonium iodide partial pressure and evaporation onset for the growth of co-evaporated methylammonium lead iodide absorbers.

Sci Rep 2021 Jul 27;11(1):15299. Epub 2021 Jul 27.

Thin Film Photovoltaics, Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06120, Halle, Saale, Germany.

Vacuum-based co-evaporation promises to bring perovskite solar cells to larger scales, but details of the film formation from the physical vapor phase are still underexplored. In this work, we investigate the growth of methylammonium lead iodide (MAPbI[Formula: see text]) absorbers prepared by co-evaporation of methylammonium iodide (MAI) and lead iodide (PbI[Formula: see text]) using an in situ X-ray diffraction setup. This setup allows us to characterize crystallization and phase evolution of the growing thin film. Read More

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Ecotoxicological Effects of Bimetallic PdNi/MWCNT and PdCu/MWCNT Nanoparticles onto DNA Damage and Oxidative Stress in Earthworms.

Biol Trace Elem Res 2021 Jul 27. Epub 2021 Jul 27.

Department of Medical Services and Techniques, Tuzluca Vocational School, University of Igdır, Igdır, Turkey.

Bimetallic nanoparticles are synthesized using two different metal elements and used recently in many fields. However, limited studies related to the ecotoxic effects of nanoparticles available in the literature. The purpose of this study is to synthesize and characterize bimetallic PdCu/MWCNT and PdNi/MWCNT NPs and investigate their ecotoxic effects on earthworms. Read More

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Direct probing of phonon mode specific electron-phonon scatterings in two-dimensional semiconductor transition metal dichalcogenides.

Nat Commun 2021 Jul 26;12(1):4520. Epub 2021 Jul 26.

Korea Research Institute of Standards and Science, Daejeon, Republic of Korea.

Electron-phonon scatterings in solid-state systems are pivotal processes in determining many key physical quantities such as charge carrier mobilities and thermal conductivities. Here, we report direct probing of phonon mode specific electron-phonon scatterings in layered semiconducting transition metal dichalcogenides WSe, MoSe, WS, and MoS through inelastic electron tunneling spectroscopy measurements, quantum transport simulations, and density functional calculation. We experimentally and theoretically characterize momentum-conserving single- and two-phonon electron-phonon scatterings involving up to as many as eight individual phonon modes in mono- and bilayer films, among which transverse, longitudinal acoustic and optical, and flexural optical phonons play significant roles in quantum charge flows. Read More

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Interparticle interactions and rheological signatures of TiCT MXene dispersions.

J Colloid Interface Sci 2021 Jul 18;605:120-128. Epub 2021 Jul 18.

Artie McFerrin, Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA. Electronic address:

Hypothesis: We hypothesize that dispersed TiCT MXene particle interactions are reflected in the bulk viscoelastic properties of the dispersions and can be analyzed using classical colloidal theory for anisotropic particles. The relevant kinetic theory for Brownian anisotropic particles is given by the Doi and Edwards (D-E) Model, and the Maxwell Model is used to fit the relaxation times as a function of frequency. Such behavior is relevant to a variety of MXene processing techniques, particularly printing and coating. Read More

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Molecular insights on CALX-CBD12 inter-domain dynamics from MD simulations, RDCs and SAXS.

Biophys J 2021 Jul 23. Epub 2021 Jul 23.

Institute of Chemistry, Department of Biochemistry, University of São Paulo, São Paulo, Brazil. Electronic address:

Na/Ca exchangers (NCX) are secondary active transporters that couple the translocation of Na with the transport of Ca in the opposite direction. The exchanger is an essential Ca extrusion mechanism in excitable cells. It consists of a transmembrane domain and a large intracellular loop that contains two Ca-binding domains, CBD1 and CBD2. Read More

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Importance of Substrate-Particle Repulsion for Protein-Templated Assembly of Metal Nanoparticles.

Langmuir 2021 Aug 26;37(30):9111-9119. Epub 2021 Jul 26.

Department of Chemistry, University of Washington, Seattle, Washington 98195, United States.

We study the protein-directed assembly of colloidal gold nanoparticles on designed protein nanofiber templates. Using sequential assembly on glass substrates, we attach positively charged gold nanoparticles to protein nanofibers engineered to have a high density of negatively charged surface residues. Using a combination of electron and optical microscopy, we measure the density of particle attachment and characterize binding specificity. Read More

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A multi-step nucleation process determines the kinetics of prion-like domain phase separation.

Nat Commun 2021 07 23;12(1):4513. Epub 2021 Jul 23.

Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.

Compartmentalization by liquid-liquid phase separation (LLPS) has emerged as a ubiquitous mechanism underlying the organization of biomolecules in space and time. Here, we combine rapid-mixing time-resolved small-angle X-ray scattering (SAXS) approaches to characterize the assembly kinetics of a prototypical prion-like domain with equilibrium techniques that characterize its phase boundaries and the size distribution of clusters prior to phase separation. We find two kinetic regimes on the micro- to millisecond timescale that are distinguished by the size distribution of clusters. Read More

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Study of Segregation in Non-Dilute Solutions of Linear Diblock Copolymers and Symmetric Miktoarm (or Janus Star) Polymers Using Monte Carlo Simulations with the Bond Fluctuation Model.

Authors:
Juan J J Freire

Polymers (Basel) 2021 Jul 20;13(14). Epub 2021 Jul 20.

Departamento de Ciencias y Técnicas Fisicoquímicas, Facultad de Ciencias, Avenida de Esparta s/n, 28232 Las Rozas-Madrid, Spain.

The bond fluctuation model was employed to characterize the approach to the mesophase separation transition of pure linear AB copolymers and symmetric miktoarms, also called Janus, star polymers, AB , where f = 6 or 12 is the total number of arms, in a common good solvent. We consider a concentration sufficiently high to mimic the melting behavior and also a lower concentration. The segregation between A and B units is represented by a repulsive interaction parameter, . Read More

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Mechanism of human γD-crystallin protein aggregation in UV-C light.

Mol Vis 2021 1;27:415-428. Epub 2021 Jul 1.

Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, India.

Purpose: To characterize intermediate aggregate species on the aggregation pathway of γD-crystallin protein in ultraviolet (UV)-C light.

Methods: The kinetics of γD-crystallin protein aggregation was studied with reversed-phase high-performance liquid chromatography (RP-HPLC) sedimentation assay, ThT binding assay, and light scattering. We used analytical ultracentrifugation to recognize intermediate aggregate species and characterized them with Fourier transform infrared spectroscopy (FTIR). Read More

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Broadly cross-reactive human antibodies that inhibit genogroup I and II noroviruses.

Nat Commun 2021 07 14;12(1):4320. Epub 2021 Jul 14.

Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.

The rational development of norovirus vaccine candidates requires a deep understanding of the antigenic diversity and mechanisms of neutralization of the virus. Here, we isolate and characterize a panel of broadly cross-reactive naturally occurring human monoclonal IgMs, IgAs and IgGs reactive with human norovirus (HuNoV) genogroup I or II (GI or GII). We note three binding patterns and identify monoclonal antibodies (mAbs) that neutralize at least one GI or GII HuNoV strain when using a histo-blood group antigen (HBGA) blocking assay. Read More

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Versatile Route toward Hydrophobically Polymer-Grafted Gold Nanoparticles from Aqueous Dispersions.

J Phys Chem B 2021 07 14;125(29):8225-8237. Epub 2021 Jul 14.

Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.

Stabilization of gold nanoparticles in organic solvents is a key challenge in making them available for a wider range of material applications. Polymers are often used as stabilizing ligands because they also allow for the introduction of new properties and functionalities. Many of the established synthesis protocols for gold nanoparticles are water-based. Read More

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Reproducibility of protein x-ray diffuse scattering and potential utility for modeling atomic displacement parameters.

Struct Dyn 2021 Jul 8;8(4):044701. Epub 2021 Jul 8.

Department of Biochemistry and the Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588, USA.

Protein structure and dynamics can be probed using x-ray crystallography. Whereas the Bragg peaks are only sensitive to the average unit-cell electron density, the signal between the Bragg peaks-diffuse scattering-is sensitive to spatial correlations in electron-density variations. Although diffuse scattering contains valuable information about protein dynamics, the diffuse signal is more difficult to isolate from the background compared to the Bragg signal, and the reproducibility of diffuse signal is not yet well understood. Read More

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Detection and characterization of folded-chain clusters in the structured melt of isotactic polypropyl-ene.

IUCrJ 2021 Jul 15;8(Pt 4):595-607. Epub 2021 May 15.

Institute of Solid State Physics, CAS Key Laboratory of Photovoltaic and Energy Conservation Materials, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, People's Republic of China.

Despite ceaseless efforts in past decades, the memory effect of semi-crystalline polymers has not been elucidated completely yet. An important reason why is that residual lamellar crystals in the structured melt are difficult to characterize. Recently, we developed a new small-angle X-ray scattering (SAXS) theory [Li (2019). Read More

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Effect of the Anchoring Layer and Transport Type on the Adsorption Kinetics of Lambda Carrageenan.

J Phys Chem B 2021 07 13;125(28):7797-7808. Epub 2021 Jul 13.

Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, 12163 Berlin, Germany.

The kinetics of lambda carrageenan (λ-car) adsorption/desorption on/from anchoring layers under diffusion- and convection-controlled transport conditions were investigated. The eighth generation of poly(amidoamine) dendrimers and branched polyethyleneimine possessing different shapes and polydispersity indexes were used for anchoring layer formation. Dynamic light scattering, electrophoresis, streaming potential measurements, optical waveguide lightmode spectroscopy, and quartz crystal microbalance were applied to characterize the formation of mono- and bilayers. Read More

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Magnetic properties of the Ising-like rare earth pyrosilicate: D-ErSiO.

J Phys Condens Matter 2021 Aug 2;33(40). Epub 2021 Aug 2.

Department of Physics, Colorado State University, 200 W. Lake St., Fort Collins, CO 80523-1875, United States of America.

Ising-like spin-1/2 magnetic materials are of interest for their ready connection to theory, particularly in the context of quantum critical behavior. In this work we report detailed studies of the magnetic properties of a member of the rare earth pyrosilicate family, D-ErSiO, which is known to display a highly anisotropic Ising-like-tensor and effective spin-1/2 magnetic moments. We used powder neutron diffraction, powder inelastic neutron spectroscopy (INS), and single crystal AC susceptibility to characterize its magnetic properties. Read More

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A novel layered double hydroxide-hesperidin nanoparticles exert antidiabetic, antioxidant and anti-inflammatory effects in rats with diabetes.

Mol Biol Rep 2021 Jun 10;48(6):5217-5232. Epub 2021 Jul 10.

Biotechnology and Life Sciences Department, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University, Beni-Suef, Egypt.

Background: Incidence of diabetes has increased significantly worldwide over recent decades. Our objective was to prepare and characterize a novel nano-carrier of hesperidin to achieve a sustained release of hesperidin and to explore the potency of the novel formula as an antidiabetic agent compared to metformin in type 2 diabetic rats.

Methods: Hesperidin was loaded on MgAl-layered double hydroxide (LDH). Read More

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Large-Scale Mapping of Moiré Superlattices by Hyperspectral Raman Imaging.

Adv Mater 2021 Jul 9:e2008333. Epub 2021 Jul 9.

Department of Physics, University of Regensburg, 93053, Regensburg, Germany.

Moiré superlattices can induce correlated-electronic phases in twisted van der Waals materials: strongly correlated quantum phenomena emerge, such as superconductivity and the Mott-insulating state. However, moiré superlattices produced through artificial stacking can be quite inhomogeneous, which hampers the development of a clear correlation between the moiré period and the emerging electrical and optical properties. Here, it is demonstrated in twisted-bilayer transition-metal dichalcogenides that low-frequency Raman scattering can be utilized not only to detect atomic reconstruction, but also to map out the inhomogeneity of the moiré lattice over large areas. Read More

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Current limits of structural biology: The transient interaction between cytochrome and photosystem I.

Curr Res Struct Biol 2020 26;2:171-179. Epub 2020 Aug 26.

Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany.

Trimeric photosystem I from the cyanobacterium (PSI) is an intrinsic membrane protein, which converts solar energy into electrical energy by oxidizing the soluble redox mediator cytochrome (Cyt ) and reducing ferredoxin. Here, we use cryo-electron microscopy and small angle neutron scattering (SANS) to characterize the transient binding of Cyt to PSI. The structure of PSI cross-linked to Cyt was solved at a resolution of 2. Read More

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Methods, development and applications of small-angle X-ray scattering to characterize biological macromolecules in solution.

Curr Res Struct Biol 2020 27;2:164-170. Epub 2020 Aug 27.

EMBL Hamburg Unit, c/o DESY, Notkestr. 85, 22607, Hamburg, Germany.

Applications of small-angle X-ray scattering (SAXS) in structural biology are reviewed. A brief introduction of the SAXS basics is followed by the presentation of the structural features of biological macromolecules in solution that can be assessed by SAXS. The approaches are considered allowing one to obtain low resolution three-dimensional (3D) structural models and to describe assembly states and conformations. Read More

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Effect of nanoparticles on spontaneous Ouzo emulsification.

J Colloid Interface Sci 2021 Jun 22;603:572-581. Epub 2021 Jun 22.

Univ Rennes, CNRS, ISCR-UMR6226, F-35000 Rennes, France. Electronic address:

Particles stabilize fluid interfaces. In particular, oil/water Pickering emulsions undergo limited coalescence, yielding droplets of smaller size as the amount of particles is increased. Herein, we studied the effect of hydrophobic nanoparticles (<10 nm, alkyl-coated) on submicronic droplets (ca 100 nm) formed in an Ouzo system. Read More

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studies for characterization and identification of nanocrystalline copper pyrophosphate confined in mesoporous silica.

Nanotechnology 2021 Jul 20;32(41). Epub 2021 Jul 20.

Institute of Nuclear Physics, Polish Academy of Sciences, Kraków, Poland.

Here we employ a novel method for preparing the homogeneous copper pyrophosphate nanocrystals inside silica mesopores. In order to characterize and identify synthesized nanocrystals we performed thestudies of thephase of CuPO. The electronic and crystal structure were optimized within the density functional theory with the strong electron interactions in the3dstates on copper atoms and van der Waals corrections included in calculations. Read More

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Small Angle X-ray Scattering, Molecular Modeling, and Chemometric Studies from a Thrombin-Like (Lmr-47) Enzyme of Venom.

Molecules 2021 Jun 28;26(13). Epub 2021 Jun 28.

Interdisciplinary Medical Research Laboratory, Oswaldo Cruz Institute/FIOCRUZ, Rio de Janeiro 21040-900, Brazil.

Introduction: Snakebite envenomation is considered a neglected tropical disease, and SVTLEs critical elements are involved in serious coagulopathies that occur on envenoming. Although some enzymes of this group have been structurally investigated, it is essential to characterize other proteins to better understand their unique properties such as the 47 kDa (Lmr-47) venom serine protease.

Methods: The structure of Lmr-47 was studied in solution, using SAXS, DLS, CD, and in silico by homology modeling. Read More

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Development, Characterization, and Immunomodulatory Evaluation of Carvacrol-loaded Nanoemulsion.

Molecules 2021 Jun 25;26(13). Epub 2021 Jun 25.

Laboratory of Synthesis and Drug Delivery, State University of Paraiba, João Pessoa, PB 58071-160, Brazil.

Carvacrol (CV) is an essential oil with numerous therapeutic properties, including immunomodulatory activity. However, this effect has not been studied in nanoemulsion systems. The objective of this study was to develop an innovative carvacrol-loaded nanoemulsion (CVNE) for immunomodulatory action. Read More

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Continuous Microfluidic Production of Citrem-Phosphatidylcholine Nano-Self-Assemblies for Thymoquinone Delivery.

Nanomaterials (Basel) 2021 Jun 7;11(6). Epub 2021 Jun 7.

Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.

Lamellar and non-lamellar liquid crystalline nanodispersions, including liposomes, cubosomes, and hexosomes are attractive platforms for drug delivery, bio-imaging, and related pharmaceutical applications. As compared to liposomes, there is a modest number of reports on the continuous production of cubosomes and hexosomes. Using a binary lipid mixture of citrem and soy phosphatidylcholine (SPC), we describe the continuous production of nanocarriers for delivering thymoquinone (TQ, a substance with various therapeutic potentials) by employing a commercial microfluidic hydrodynamic flow-focusing chip. Read More

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Facilitated and Controlled Strontium Ranelate Delivery Using GCS-HA Nanocarriers Embedded into PEGDA Coupled with Decortication Driven Spinal Regeneration.

Int J Nanomedicine 2021 22;16:4209-4224. Epub 2021 Jun 22.

Graduate Institute of Biomedical Materials and Tissue Engineering, International PhD Program in Biomedical Engineering, School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, 11031, Taiwan.

Background And Purpose: Strontium ranelate (SrR) is an oral pharmaceutical agent for osteoporosis. In recent years, numerous unwanted side effects of oral SrR have been revealed. Therefore, its clinical administration and applications are limited. Read More

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Revealing the bonding of solvated Ru complexes with valence-to-core resonant inelastic X-ray scattering.

Chem Sci 2021 Jan 29;12(10):3713-3725. Epub 2021 Jan 29.

SSRL, SLAC National Accelerator Laboratory Menlo Park California 94025 USA

Ru-complexes are widely studied because of their use in biological applications and photoconversion technologies. We reveal novel insights into the chemical bonding of a series of Ru(ii)- and Ru(iii)-complexes by leveraging recent advances in high-energy-resolution tender X-ray spectroscopy and theoretical calculations. We perform Ru 2p4d resonant inelastic X-ray scattering (RIXS) to probe the valence excitations in dilute solvated Ru-complexes. Read More

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January 2021