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https://www.readbyqxmd.com/read/28340527/synthesis-and-adsorption-properties-of-4-vinylpyridine-and-styrene-copolymer-in-situ-immobilized-on-silica-surface
#1
E S Yanovska, L O Vretik, O A Nikolaeva, Y Polonska, D Sternik, O Yu Kichkiruk
Copolymer of 4-vinylpyridine with styrene was in situ immobilized on silica gel surface via the heterogeneous radical polymerization. Anchorage of the copolymer on the surface layer was confirmed by IR spectroscopy. The quantity of copolymer on the silica gel surface was evaluated as 25.73 wt.% by TG and DSC-MS analysis. "Islet" location of polymer layer on the silica surface was confirmed by the scanning electron microscopy. A high adsorption activity of silica gel with immobilized copolymer towards microquantitatives of Cu(II), Cd(II), Pb(II), Fe(III), and Ni(II) ions in steady state conditions as well as of Ni(II) ions in dynamic regime was found...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28339019/occupational-exposure-to-mount-etna-s-basaltic-dust-assessment-of-mutagenic-and-cytotoxic-effects
#2
Caterina Ledda, Salvatore Cocuzza, Monica Salerno, Paola Senia, Serena Matera, Venerando Rapisarda, Carla Loreto
Basalt and volcanic ash are natural constituents of the ground surrounding volcanic areas such as Mount Etna. The dust may be daily inhaled by the general population as well as by several types of workers, such as construction workers. In this experiment, we analyzed the potential mutagenic and cytotoxic effects of the materials used in construction industry, excavated from Mt. Etna. Ground basalt (A), volcanic ash (B), mixed basalt and cement (C) and cement (D) were studied with Ames test, for mutagenic assessment and with MMT assay for cytotoxic evaluation...
March 24, 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28338408/clofazimine-encapsulation-in-nanoporous-silica-particles-for-the-oral-treatment-of-antibiotic-resistant-mycobacterium-tuberculosis-infections
#3
Sabrina Valetti, Xin Xia, Joana Costa-Gouveia, Priscille Brodin, Marie-Françoise Bernet-Camard, Margareta Andersson, Adam Feiler
AIM: First extensive reformulation of clofazimine (CLZ) in nanoporous silica particles (NSPs) for tackling antibiotic-resistant tuberculosis (TB) infections. MATERIALS & METHODS: Solid-state characterization of several CLZ-encapsulated NSP formulations was followed by in vitro drug solubility, Caco-2 intestinal cells drug permeability and TB antibacterial activity. RESULTS: NSPs stabilize the amorphous state of CLZ (shelf stability >6 months) and dramatically increase the drug solubility in simulated gastric fluid (up to 20-fold) with different dissolution kinetics depending on the NSPs used...
March 24, 2017: Nanomedicine
https://www.readbyqxmd.com/read/28338342/development-of-matrix-solid-phase-dispersion-coupled-with-high-performance-liquid-chromatography-for-determination-of-jolkinolide-a-and-jolkinolide-b-in-euphorbia-fischeriana-steud
#4
Defu Cai, Weiyu Zhai, Qi Zhang, Jianhua Liu, Yu Sun, Lei Liu, Jicheng Liu
A novel and simple method was established for the extraction and determination of jolkinolide A and B in Euphorbia fischeriana Steud. using matrix solid-phase dispersion (MSPD) extraction and high-performance liquid chromatography (HPLC). The optimised conditions for the MSPD extraction were determined to be that silica gel was served as dispersant, the mass ratio of sample to silica gel was selected to be 1:4, and 5 mL of acetonitrile was used as elution solvent. The method exhibited a good performance in terms of linearity (r(2) ≥ 0...
March 24, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28338148/extraction-of-minor-actinides-lanthanides-and-other-fission-products-by-silica-immobilized-btbp-btphen-ligands
#5
Ashfaq Afsar, Petr Distler, Laurence M Harwood, Jan John, James Westwood
Novel BTBP [bis-(1,2,4-triazin-3-yl)-2,2'-bipyridine]/BTPhen [bis-(1,2,4-triazin-3-yl)-1,10-phenanthroline] functionalized silica gels have been developed to extract minor actinides, lanthanides and other fission products. BTPhen functionalized silica gel is capable of near-quantitative removal of Am(iii) in the presence of Eu(iii) from aqueous HNO3, while BTBP functionalized silica gel is able to remove problematic corrosion and fission products that are found in PUREX raffinates.
March 24, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28337620/date-palm-waste-derived-biochar-composites-with-silica-and-zeolite-synthesis-characterization-and-implication-for-carbon-stability-and-recalcitrant-potential
#6
Munir Ahmad, Mahtab Ahmad, Adel R A Usman, Abdullah S Al-Faraj, Adel Abduljabbar, Yong Sik Ok, Mohammad I Al-Wabel
Engineered organo-mineral composites were synthesized from date palm waste biochar and silica or zeolite via mechanochemical treatments. Date palm tree rachis (leaves) waste biomass was pre-treated with silica or zeolite minerals via ball milling and sonication prior to pyrolysis at 600 °C. The resultant organo-mineral composites and pristine materials were characterized using X-ray diffraction, thermogravimetric-differential thermal (TG-DTA), Fourier transform infrared, scanning electron microscope analyses and surface area and porosity analyzer to investigate the variations in physiochemical and structural characteristics...
March 23, 2017: Environmental Geochemistry and Health
https://www.readbyqxmd.com/read/28337401/a-rapid-approach-for-fabricating-boronic-acid-functionalized-plates-for-on-probe-detection-of-glycoprotein-and-glycopeptide
#7
Yu-Ching Liu, Chao-Jung Chen
We developed a rapid and simple approach without using complex mechanical or chemical protocols to fabricate boronic acid-functionalized plates for glycoprotein or glycopeptide enrichment and mass spectrometry (MS) analysis. By coating the boronic acid-functionalized silica particles on a polydimethylsiloxane (PDMS)-coated matrix-assisted laser desorption/ionization (MALDI) plate, these particles can form a firmly monolayer of particles on PDMS membrane for sample handling without peeling off. The boronic acid particles-coated PDMS plate (BP plate) was successfully applied to the enrichment of horseradish peroxidase (HRP) protein and their digested glycopeptides...
2017: Mass Spectrometry
https://www.readbyqxmd.com/read/28337400/prototype-of-an-interface-for-hyphenating-distillation-with-gas-chromatography-and-mass-spectrometry
#8
Ya-Ru Tang, Hui-Hsien Yang, Pawel L Urban
Chemical analysis of complex matrices-containing hundreds of compounds-is challenging. Two-dimensional separation techniques provide an efficient way to reduce complexity of mixtures analyzed by mass spectrometry (MS). For example, gasoline is a mixture of numerous compounds, which can be fractionated by distillation techniques. However, coupling conventional distillation with other separations as well as MS is not straightforward. We have established an automatic system for online coupling of simple microscale distillation with gas chromatography (GC) and electron ionization MS...
2017: Mass Spectrometry
https://www.readbyqxmd.com/read/28337243/residue-specific-interactions-of-an-intrinsically-disordered-protein-with-silica-nanoparticles-and-their-quantitative-prediction
#9
Mouzhe Xie, Alexandar L Hansen, Jiaqi Yuan, Rafael Brüschweiler
Elucidation of the driving forces that govern interactions between nanoparticles and intrinsically disordered proteins (IDP) is important for the understanding of the effect of nanoparticles in living systems and for the design of new nanoparticle-based assays to monitor health and combat disease. The quantitative interaction profile of the intrinsically disordered transactivation domain of p53 and its mutants with anionic silica nanoparticles is reported at atomic resolution using nuclear magnetic spin relaxation experiments...
October 27, 2016: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
https://www.readbyqxmd.com/read/28336881/the-influence-of-new-hydrophobic-silica-nanoparticles-on-the-surface-properties-of-the-films-obtained-from-bilayer-hybrids
#10
Cristian Petcu, Violeta Purcar, Cătălin-Ilie Spătaru, Elvira Alexandrescu, Raluca Şomoghi, Bogdan Trică, Sabina Georgiana Niţu, Denis Mihaela Panaitescu, Dan Donescu, Maria-Luiza Jecu
Ultra-hydrophobic bilayer coatings on a glass surface were fabricated by sol-gel process using hexadecyltrimethoxysilane (C16TMS) and tetramethoxysilane (TMOS) (1:4 molar ratio) as precursors. After coating, silica nanoparticles (SiO₂ NPs) functionalized with different mono-alkoxy derivatives (methoxytrimethylsilane, TMeMS; ethoxydimethylvinylsilane, DMeVES; ethoxydimethylphenylsilane, DMePhES; and methoxydimethyloctylsilane, DMeC₈MS) were added, assuring the microscale roughness on the glass surface. Influences of the functionalized SiO₂ NPs and surface morphology on the hydrophobicity of the hybrid films were discussed...
February 20, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28336876/recent-advances-in-research-on-the-synthetic-fiber-based-silica-aerogel-nanocomposites
#11
REVIEW
Agnieszka Ślosarczyk
The presented paper contains a brief review on the synthesis and characterization of silica aerogels and its nanocomposites with nanofibers and fibers based on a literature study over the past twenty years and my own research. Particular attention is focused on carbon fiber-based silica aerogel nanocomposites. Silica aerogel is brittle in nature, therefore, it is necessary to improve this drawback, e.g., by polymer modification or fiber additives. Nevertheless, there are very few articles in the literature devoted to the synthesis of silica aerogel/fiber nanocomposites, especially those focusing on carbon fibers and nanofibers...
February 16, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28336852/amorphous-silica-particles-relevant-in-food-industry-influence-cellular-growth-and-associated-signaling-pathways-in-human-gastric-carcinoma-cells
#12
Anja Wittig, Helge Gehrke, Giorgia Del Favero, Eva-Maria Fritz, Marco Al-Rawi, Silvia Diabaté, Carsten Weiss, Haider Sami, Manfred Ogris, Doris Marko
Nanostructured silica particles are commonly used in biomedical and biotechnical fields, as well as, in cosmetics and food industry. Thus, their environmental and health impacts are of great interest and effects after oral uptake are only rarely investigated. In the present study, the toxicological effects of commercially available nano-scaled silica with a nominal primary diameter of 12 nm were investigated on the human gastric carcinoma cell line GXF251L. Besides the analysis of cytotoxic and proliferative effects and the comparison with effects of particles with a nominal primary diameter of 200 nm, emphasis was also given to their influence on the cellular epidermal growth factor receptor (EGFR) and mitogen-activated protein kinases (MAPK) signaling pathways-both of them deeply involved in the regulation of cellular processes like cell cycle progression, differentiation or proliferation...
January 13, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28336842/sers-based-flavonoid-detection-using-ethylenediamine-%C3%AE-cyclodextrin-as-a-capturing-ligand
#13
Jae Min Choi, Eunil Hahm, Kyeonghui Park, Daham Jeong, Won-Yeop Rho, Jaehi Kim, Dae Hong Jeong, Yoon-Sik Lee, Sung Ho Jhang, Hyun Jong Chung, Eunae Cho, Jae-Hyuk Yu, Bong-Hyun Jun, Seunho Jung
Ethylenediamine-modified β-cyclodextrin (Et-β-CD) was immobilized on aggregated silver nanoparticle (NP)-embedded silica NPs (SiO₂@Ag@Et-β-CD NPs) for the effective detection of flavonoids. Silica NPs were used as the template for embedding silver NPs to create hot spots and enhance surface-enhanced Raman scattering (SERS) signals. Et-β-CD was immobilized on Ag NPs to capture flavonoids via host-guest inclusion complex formation, as indicated by enhanced ultraviolet absorption spectra. The resulting SiO₂@Ag@Et-β-CD NPs were used as the SERS substrate for detecting flavonoids, such as hesperetin, naringenin, quercetin, and luteolin...
January 6, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28336835/improving-powder-magnetic-core-properties-via-application-of-thin-insulating-silica-nanosheet-layers-on-iron-powder-particles
#14
Toshitaka Ishizaki, Hideyuki Nakano, Shin Tajima, Naoko Takahashi
A thin, insulating layer with high electrical resistivity is vital to achieving high performance of powder magnetic cores. Using layer-by-layer deposition of silica nanosheets or colloidal silica over insulating layers composed of strontium phosphate and boron oxide, we succeeded in fabricating insulating layers with high electrical resistivity on iron powder particles, which were subsequently used to prepare toroidal cores. The compact density of these cores decreased after coating with colloidal silica due to the substantial increase in the volume, causing the magnetic flux density to deteriorate...
December 23, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28335979/microfluidic-immunosensor-based-on-mesoporous-silica-platform-and-cmk-3-poly-acrylamide-co-methacrylate-of-dihydrolipoic-acid-modified-gold-electrode-for-cancer-biomarker-detection
#15
Matías Regiart, Martin A Fernández-Baldo, Jhonny Villarroel-Rocha, Germán A Messina, Franco A Bertolino, Karim Sapag, Aaron T Timperman, Julio Raba
We report a hybrid glass-poly (dimethylsiloxane) microfluidic immunosensor for epidermal growth factor receptor (EGFR) determination, based on the covalent immobilization of anti-EGFR antibody (anti-EGFR) on amino-functionalized mesoporous silica (AMS) retained in the central channel of a microfluidic device. The synthetized AMS was characterized by N2 adsorption-desorption isotherm, scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and infrared spectroscopy. The cancer biomarker was quantified in human serum samples by a direct sandwich immunoassay measuring through a horseradish peroxidase-conjugated anti-EGFR...
April 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28335970/quinine-bonded-to-superficially-porous-particles-for-high-efficiency-and-ultrafast-liquid-and-supercritical-fluid-chromatography
#16
Darshan C Patel, Zachary S Breitbach, JeongJae Yu, Kate A Nguyen, Daniel W Armstrong
Two new anion-exchange columns were prepared by bonding tert-butyl carbamoylated quinine to 2.7 μm superficially porous particle (SPP) silica to create chiral stationary phases for high-efficiency and ultrafast chromatography. Performance and retention parameters of these new columns are compared with an analogous 5 μm fully porous particle (FPP) based Chiralpak QNAX column and a 3-4 fold increase in efficiency was observed. Ultrafast separations ranging from 12 s down to sub-second are shown using 2.7 μm SPPs bonded via hydrosilation to the selector...
April 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28335969/design-synthesis-and-application-of-a-new-class-of-stimuli-responsive-separation-materials
#17
Roshanak Sepehrifar, Reinhard I Boysen, Basil Danylec, Yuanzhong Yang, Kei Saito, Milton T W Hearn
A new class of efficient stationary phase has been investigated for use in the liquid chromatographic separation of low molecular weight analytes and high molecular weight biomolecules, based on the application of immobilised stimuli-responsive polymers (SRPs). To this end, two polymeric units, namely poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) and poly(acrylic acid) (PAA) were tethered to a triazine core. The derived poly(2-dimethyl-aminoethyl methacrylate)-block-poly(acrylic acid) (PDMAEMA-b-PAA), as a diblock co-polymer, was then immobilised onto the surface of porous silica particles...
April 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28335968/dipentaerythritol-penta-hexa-acrylate-based-highly-cross-linked-hybrid-monolithic-column-preparation-and-its-applications-for-ultrahigh-efficiency-separation-of-proteins
#18
Junqian Ma, Qian Dai, Xueyun Li, Xianghui Zhu, Teng Ma, Xiaoqiang Qiao, Shigang Shen, Xiuhua Liu
In this study, multi-acrylate based dipentaerythritol penta-/hexa-acrylate (DPEPA) was exploited for fabrication of highly cross-linked hybrid monolithic column by copolymerization with polyhedral oligomeric silsesquioxane methacryl substituted (POSS-MA) via a "one-pot" method. The new DPEPA-POSS hybrid monolithic column was respectively characterized by Fourier transform infrared spectrometry, thermogravimetric analysis, scanning electron microscopy and nitrogen adsorption/desorption measurement. When it was used for the separation of amides, thioureas and positional isomers of phenols, ultrahigh column efficiency separation (up to 511,000 N m(-1)) was achieved with excellent selectivity...
April 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28335967/an-innovative-monolithic-zwitterionic-stationary-phase-for-the-separation-of-phenolic-acids-in-coffee-bean-extracts-by-capillary-electrochromatography
#19
Adele Murauer, Rania Bakry, Herwig Schottenberger, Christian Huck, Markus Ganzera
A methacrylate based monolith, containing the innovative zwitterionic monomer (3-allyl-1-imidazol)propane sulfonate, was prepared in 100 μm I.D. silica capillaries by UV initiated photo-polymerization. Composition of the porogen, i.e. a mixture of 1-propanol, 1,4 butanediol and water, was of great importance to obtain a homogeneous monolith with satisfactory permeability and good electrochromatographic performance. Morphology of the stationary phase was studied in Scanning Electron Microscopy and IR experiments, which revealed a good attachment to the capillary wall, flowthrough-pores in the range of 0...
April 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28335360/super-hydrophobic-icephobic-coatings-based-on-silica-nanoparticles-modified-by-self-assembled-monolayers
#20
Junpeng Liu, Zaid A Janjua, Martin Roe, Fang Xu, Barbara Turnbull, Kwing-So Choi, Xianghui Hou
A super-hydrophobic surface has been obtained from nanocomposite materials based on silica nanoparticles and self-assembled monolayers of 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS) using spin coating and chemical vapor deposition methods. Scanning electron microscope images reveal the porous structure of the silica nanoparticles, which can trap small-scale air pockets. An average water contact angle of 163° and bouncing off of incoming water droplets suggest that a super-hydrophobic surface has been obtained based on the silica nanoparticles and POTS coating...
December 2, 2016: Nanomaterials
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