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https://www.readbyqxmd.com/read/28646781/%C3%AE-potential-evidences-silanol-heterogeneity-induced-by-metal-contaminants-at-the-quartz-surface-implications-in-membrane-damage
#1
Cristina Pavan, Francesco Turci, Maura Tomatis, Mara Ghiazza, Dominique Lison, Bice Fubini
Among the physico-chemical features responsible for the so-called "variability of quartz hazard", a key role has been assigned to the silica surface charge, evaluated by means of ζ potential measurement. The ζ potential of silica describes the protonation state of silanols which, in turn, determine interactions with cell membranes. To gain a molecular understanding of the role of silanols in silica pathogenicity, we conducted a systematic investigation of the variation of the ζ potential as a function of pH (ζ plot titration curve) on a large set of respirable quartz particles with different levels of metal contaminants...
June 13, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28646758/thermo-responsive-diblock-and-triblock-cationic-copolymers-at-the-silica-aqueous-interface-a-qcm-d-and-afm-study
#2
Saeed Zajforoushan Moghaddam, Kaizheng Zhu, Bo Nyström, Esben Thormann
The properties of synthesized diblock poly(N-isopropylacrylamide)-poly((3-acrylamidopropyl)trimethylammonium chloride) and triblock methoxy-poly(ethylene glycol)-poly(N-isopropylacrylamide)-poly((3-acrylamidopropyl)trimethylammonium chloride) cationic copolymers at the silica/aqueous interface are investigated using quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). Moreover, dynamic light scattering is employed to assess the copolymers in terms of the hydrodynamic size and interchain aggregation...
June 15, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28646718/reduced-graphene-oxide-functionalized-feooh-for-signal-on-photoelectrochemical-sensing-of-prostate-specific-antigen-with-bioresponsive-controlled-release-system
#3
Qian Zhou, Youxiu Lin, Jian Shu, Kangyao Zhang, Zhenzhong Yu, Dianping Tang
A new and signal-on photoelectrochemical (PEC) sensing platform was successfully designed for the sensitive detection of prostate-specific antigen (PSA), using reduced graphene oxide- functionalized iron oxyhydroxide (FeOOH-rGO) as the photoactive material, accompanying target-responsive controlled release system to achieve the signal amplification. Introduction of rGO as electron mediator greatly facilitated the electron transfer from FeOOH to electrode under visible light, which inhibited the electron-hole recombination to enhance the photo-activity of FeOOH-rGO...
June 16, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28646300/methodology-for-non-target-screening-of-sewage-sludge-using-comprehensive-two-dimensional-gas-chromatography-coupled-to-high-resolution-mass-spectrometry
#4
Cathrin Veenaas, Peter Haglund
To investigate the wide range of pollutants occurring in sewage sludge, an analytical method for comprehensive non-target screening is needed. To the best of our knowledge, no procedures currently exist for the full screening of organic contaminants in sewage sludge, which is the ultimate goal of this project. We developed non-discriminating sample preparation methods for gas chromatography-mass spectrometry (GC-MS) analysis. Pressurized liquid extraction (PLE) was used for extraction, with in-line (silica gel selective PLE, SPLE) or off-line clean-up (gel permeation chromatography, GPC)...
June 23, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28646143/a-comparison-between-sphere-and-rod-nanoparticles-regarding-their-in-vivo-biological-behavior-and-pharmacokinetics
#5
Yating Zhao, Yu Wang, Fu Ran, Yu Cui, Chang Liu, Qinfu Zhao, Yikun Gao, Da Wang, Siling Wang
In recent years, spherical nanoparticles has been studied extensively on biomedical applications including bioimaging and biosensing, diagnostics and theranostics, but the effect of the shape of nanoparticles has received little attention. In the present study, we designed three different shaped fluorescent mesoporous silica nanoparticles (MSNs), long rod nanoparticles (NLR), short rod nanoparticles (NSR), and spherical nanoparticles (NS) to systematically examine their behavior in vivo after oral administration...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28645754/tunable-separations-based-on-a-molecular-size-effect-for-biomolecules-by-poly-ethylene-glycol-gel-based-capillary-electrophoresis
#6
Takuya Kubo, Naoki Nishimura, Hayato Furuta, Kei Kubota, Toyohiro Naito, Koji Otsuka
We report novel capillary gel electrophoresis (CGE) with poly(ethylene glycol) (PEG)-based hydrogels for the effective separations of biomolecules containing sugars and DNAs based on a molecular size effect. The gel capillaries were prepared in a fused silica capillary modified with 3-(trimethoxysilyl)propylmethacrylate using a variety of the PEG-based hydrogels. After the fundamental evaluations in CGE regarding the separation based on the molecular size effect depending on the crosslinking density, the optimized capillary provided the efficient separation of glucose ladder (G1 to G20)...
June 16, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28645296/myd88-dependent-pro-interleukin-1%C3%AE-induction-in-dendritic-cells-exposed-to-food-grade-synthetic-amorphous-silica
#7
Hans Christian Winkler, Julian Kornprobst, Peter Wick, Lea Maria von Moos, Ioannis Trantakis, Elisabeth Maria Schraner, Barbara Bathke, Hubertus Hochrein, Mark Suter, Hanspeter Naegeli
BACKGROUND: Dendritic cells (DCs) are specialized first-line sensors of foreign materials invading the organism. These sentinel cells rely on pattern recognition receptors such as Nod-like or Toll-like receptors (TLRs) to launch immune reactions against pathogens, but also to mediate tolerance to self-antigens and, in the intestinal milieu, to nutrients and commensals. Since inappropriate DC activation contributes to inflammatory diseases and immunopathologies, a key question in the evaluation of orally ingested nanomaterials is whether their contact with DCs in the intestinal mucosa disrupts this delicate homeostatic balance between pathogen defense and tolerance...
June 23, 2017: Particle and Fibre Toxicology
https://www.readbyqxmd.com/read/28645048/phytolith-carbon-sequestration-in-global-terrestrial-biomes
#8
Zhaoliang Song, Hongyan Liu, Caroline A E Strömberg, Xiaomin Yang, Xiaodong Zhang
Terrestrial biogeochemical carbon (C) sequestration is coupled with the biogeochemical silicon (Si) cycle through mechanisms such as phytolith C sequestration, but the size and distribution of the phytolith C sink remain unclear. Here, we estimate phytolith C sequestration in global terrestrial biomes. We used biome data including productivity, phytolith and silica contents, and the phytolith stability factor to preliminarily determine the size and distribution of the phytolith C sink in global terrestrial biomes...
June 19, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28644964/determination-of-absolute-material-nonlinearity-with-air-coupled-ultrasonic-receivers
#9
David Torello, Nicholas Selby, Jin-Yeon Kim, Jianmin Qu, Laurence J Jacobs
Quantitative evaluation of the microstructural state of a specimen can be deduced from knowledge of the sample's absolute acoustic nonlinearity parameter, β, making the measurement of β a powerful tool in the NDE toolbox. However, the various methods used in the past to measure β each suffer from significant limitations. Piezoelectric contact transducers are sensitive to nonlinear signals, cheap, and simple to use, but they are hindered by the variability of the interfacial contact between transducer and specimen surface...
June 3, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28644918/heterogeneous-microtesla-sabre-enhancement-of-15n-nmr-signals
#10
Kirill V Kovtunov, Larisa M Kovtunova, Max E Gemeinhardt, Andrey V Bukhtiyarov, Jonathan Gesiorski, Valerii I Bukhtiyarov, Eduard Y Chekmenev, Igor V Koptyug, Boyd Goodson
The hyperpolarization of heteronuclei via Signal Amplification by Reversible Exchange (SABRE) was investigated under conditions of heterogeneous catalysis and microtesla magnetic fields. Immobilization of [IrCl(COD)(IMes)], [IMes = 1,3-bis(2,4,6-trimethylphenyl), imidazole-2-ylidene; COD = cyclooctadiene] catalyst onto silica particles modified with NH2(CH2)3- linkers engenders an effective heterogeneous SABRE (HET-SABRE) catalyst that was used to demonstrate ~102-fold enhancement of 15N NMR signals in pyridine at 9...
June 23, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28644614/role-of-the-protein-corona-derived-from-human-plasma-in-cellular-interactions-between-nanoporous-human-serum-albumin-particles-and-endothelial-cells
#11
Mikhail Valeryevich Zyuzin, Yan Yan, Raimo Hartmann, Katelyn T Gause, Moritz Nazarenus, Jiwei Cui, Frank Caruso, Wolfgang J Parak
The presence of a protein corona on various synthetic nanomaterials has been shown to strongly influence how they interact with cells. However, it is unclear if the protein corona also exists on protein particles, and if so, its role in particle-cell interactions. In this study, pure human serum albumin (HSA) particles were fabricated via mesoporous silica particle templating. Our data reveal that various serum proteins adsorbed on the particles. The presence of a corona from human plasma was shown to decrease particle binding to cell membrane, increase the residence time of particles in early endosomes, and reduce the amount of internalized particles within the first hours of cell exposure to particles...
June 23, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28644423/probing-the-interaction-of-dielectric-nanoparticles-with-supported-lipid-membrane-coatings-on-nanoplasmonic-arrays
#12
Abdul Rahim Ferhan, Gamaliel Junren Ma, Joshua A Jackman, Tun Naw Sut, Jae Hyeon Park, Nam-Joon Cho
The integration of supported lipid membranes with surface-based nanoplasmonic arrays provides a powerful sensing approach to investigate biointerfacial phenomena at membrane interfaces. While a growing number of lipid vesicles, protein, and nucleic acid systems have been explored with nanoplasmonic sensors, there has been only very limited investigation of the interactions between solution-phase nanomaterials and supported lipid membranes. Herein, we established a surface-based localized surface plasmon resonance (LSPR) sensing platform for probing the interaction of dielectric nanoparticles with supported lipid bilayer (SLB)-coated, plasmonic nanodisk arrays...
June 23, 2017: Sensors
https://www.readbyqxmd.com/read/28644380/adenosine-triphosphate-encapsulated-liposomes-with-plasmonic-nanoparticles-for-surface-enhanced-raman-scattering-based-immunoassays
#13
Xuan-Hung Pham, Eunil Hahm, Tae Han Kim, Hyung-Mo Kim, Sang Hun Lee, Yoon-Sik Lee, Dae Hong Jeong, Bong-Hyun Jun
In this study, we prepared adenosine triphosphate (ATP) encapsulated liposomes, and assessed their applicability for the surface enhanced Raman scattering (SERS)-based assays with gold-silver alloy (Au@Ag)-assembled silica nanoparticles (NPs; SiO₂@Au@Ag). The liposomes were prepared by the thin film hydration method from a mixture of l-α-phosphatidylcholine, cholesterol, and PE-PEG2000 in chloroform; evaporating the solvent, followed by hydration of the resulting thin film with ATP in phosphate-buffered saline (PBS)...
June 23, 2017: Sensors
https://www.readbyqxmd.com/read/28644027/speckle-visibility-spectroscopy-of-depolarized-dynamic-light-scattering
#14
David Bossert, Jens Christoph Natterodt, Dominic Andreas Urban, Christoph Weder, Alke Petri-Fink, Sandor Balog
We show that the statistical analysis of the photon counts in depolarized dynamic light scattering experiments allows for the accurate characterization of the rotational Brownian dynamics of particles. Unlike photon correlation spectroscopy, the technique is accurate even at low temporal resolution and enables discontinuous data acquisition, which offers several advantages. To demonstrate the usefulness of the method, we present a case study in which we analyze aqueous suspensions of tunicate cellulose nanocrystals and silica particles, and discuss aspects that are specific to particle sizing...
June 23, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28643834/understanding-the-remarkable-luminescence-enhancement-via-sio2-coating-on-tio2-eu-3-nanofibers
#15
Meiqi Chang, Yanhua Song, Ye Sheng, Jie Chen, Haifeng Zou
TiO2:Eu(3+) nanofibers diameters can be tuned by changing the mixed solvent ratio are synthesized via the electrospinning technique. Concentration quenching phenomena and the relationship of the PL intensity ratio I((5)D0-(7)F2)/I((5)D0-(7)F1) with the Eu doping concentration are discussed. Notably, the luminescence intensity is enhanced by about 7.8 fold by coating SiO2 gel layer on the TiO2:Eu(3+) nanofibers, which is successfully performed via a sol-gel process followed by calcination. Furthermore, these fibers are characterized systematically via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL) spectroscopy...
June 23, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28643415/cultivation-of-human-dermal-fibroblasts-and-epidermal-keratinocytes-on-keratin-coated-silica-bead-substrates
#16
Bee Yi Tan, Luong T H Nguyen, Hyo-Sop Kim, Jae-Ho Kim, Kee Woei Ng
Human hair keratin is promising as a bioactive material platform for various biomedical applications. To explore its versatility further, human hair keratin was coated onto monolayers of silica beads to produce film-like substrates. This combination was hypothesized to provide a synergistic effect in improving the biochemical properties of the resultant composite. Atomic Force Microscopy analysis showed uniform coatings of keratin on the silica beads with a slight increase in the resulting surface roughness...
June 23, 2017: Journal of Biomedical Materials Research. Part A
https://www.readbyqxmd.com/read/28642348/confined-in-fiber-solidification-and-structural-control-of-silicon-and-silicon-germanium-microparticles
#17
Alexander Gumennik, Etgar C Levy, Benjamin Grena, Chong Hou, Michael Rein, Ayman F Abouraddy, John D Joannopoulos, Yoel Fink
Crystallization of microdroplets of molten alloys could, in principle, present a number of possible morphological outcomes, depending on the symmetry of the propagating solidification front and its velocity, such as axial or spherically symmetric species segregation. However, because of thermal or constitutional supercooling, resulting droplets often only display dendritic morphologies. Here we report on the crystallization of alloyed droplets of controlled micrometer dimensions comprising silicon and germanium, leading to a number of surprising outcomes...
June 22, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28641428/liquid-liquid-phase-transition-in-an-ionic-model-of-silica
#18
Renjie Chen, Erik Lascaris, Jeremy C Palmer
Recent equation of state calculations [E. Lascaris, Phys. Rev. Lett. 116, 125701 (2016)] for an ionic model of silica suggest that it undergoes a density-driven, liquid-liquid phase transition (LLPT) similar to the controversial transition hypothesized to exist in deeply supercooled water. Here, we perform extensive free energy calculations to scrutinize the model's low-temperature phase behavior and confirm the existence of a first-order phase transition between two liquids with identical compositions but different densities...
June 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28641198/combined-computational-experimental-approach-to-predict-blood-brain-barrier-bbb-permeation-based-on-green-salting-out-thin-layer-chromatography-supported-by-simple-molecular-descriptors
#19
Krzesimir Ciura, Mariusz Belka, Piotr Kawczak, Tomasz Bączek, Michał J Markuszewski, Joanna Nowakowska
The objective of this paper is to build QSRR/QSAR model for predicting the blood-brain barrier (BBB) permeability. The obtained models are based on salting-out thin layer chromatography (SOTLC) constants and calculated molecular descriptors. Among chromatographic methods SOTLC was chosen, since the mobile phases are free of organic solvent. As consequences, there are less toxic, and have lower environmental impact compared to classical reserved phases liquid chromatography (RPLC). During the study three stationary phase silica gel, cellulose plates and neutral aluminum oxide were examined...
June 3, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28640597/positive-charge-functionalized-mesoporous-silica-nanoparticles-as-nanocarriers-for-controlled-2-4-dichlorophenoxy-acetic-acid-sodium-salt-release
#20
Lidong Cao, Zhaolu Zhou, Shujun Niu, Chong Cao, Xiuhuan Li, Yongpan Shan, Qiliang Huang
Due to its relatively high water solubility and mobility, 2,4-dichlorophenoxy acetic acid (2,4-D) has a high leaching potential threatening the surface water and groundwater. Controlled release formulations of 2,4-D could alleviate the adverse effects on the environment. In the present study, positive-charge functionalized mesoporous silica nanoparticles (MSNs) were facilely synthesized by incorporating trimethylammonium (TA) groups onto MSNs via a post-grafting method. 2,4-D sodium salt, the anionic form of 2,4-D, was effectively loaded into these positively charged MSN-TA nanoparticles...
June 22, 2017: Journal of Agricultural and Food Chemistry
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