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https://www.readbyqxmd.com/read/28930461/effect-of-a-swelling-agent-on-the-performance-of-ni-porous-silica-catalyst-for-ch4-co2-reforming
#1
Mohamad Hassan Amin, Putla Sudarsanam, Matthew R Field, Jim Patel, Suresh K Bhargava
Hierarchical porous materials are of great interest in various industrial applications because of their potential to overcome the mass transport limitations typically encountered for single-mode porous materials. This report describes the synthesis of a hierarchical tri-modal porous silica-based material using a 7.5 molar ratio of a relatively inexpensive non-ionic surfactant template, tri-block copolymer P123, EO20PO70EO20. The pore size distribution curve shows the presence of three types of pores with average diameters of ~8, 25 and 89 nm...
September 20, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28930338/biomedical-nanomotors-efficient-glucose-mediated-insulin-release
#2
Paula Díez, Berta Esteban-Fernández de Ávila, Doris E Ramírez-Herrera, Reynaldo Villalonga, Joseph Wang
We report herein the design of an autonomous glucose-responsive smart nanomachine for insulin (In) delivery based on ultrasound (US)-propelled nanomotors combined with an enzyme-based sensing-effector unit. Gold nanowire (AuNW) motors have been coupled with a mesoporous silica (MS) segment, which was gated with pH-responsive phenylboronic acid (PBA)-glucose oxidase (GOx) supramolecular nanovalves responsible for the insulin release. Glucose-induced protonation of the PBA groups triggers the opening of the pH-driven gate and uncapping of the insulin-loaded nanovalves...
September 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28930141/isolation-and-cytotoxic-investigation-of-flacourtin-from-oncoba-spinosa
#3
Olaoye S Balogun, Olukayode S Ajayi, Olayinka S Lawal
Background:Oncoba spinosa, an endangered medicinal plant whose secondary metabolites have not been extensively profiled, and which is hitherto yet to be examined for cytotoxicity, is being investigated in this study. Methods: Leaves of Oncoba spinosa (800 g) were extracted with 95% aqueous methanol. The crude extract was partitioned with n-hexane and the resultant defatted extract was extensively chromatographed on silica gel to yield compound 1 which was subjected to spectroscopic analysis. A brine shrimps lethality test was used to establish the cytotoxicity potentials of the isolated compound and the plant extracts...
December 6, 2016: Medicines (Basel, Switzerland)
https://www.readbyqxmd.com/read/28929736/substrate-versatile-approach-to-robust-antireflective-and-superhydrophobic-coatings-with-excellent-self-cleaning-property-in-varied-environments
#4
Tingting Ren, Junhui He
Robust antireflective and superhydrophobic coatings are highly desired in wide applications, such as optical devices, solar cell panels, architectural and automotive glasses, lab-on chip systems, and windows for electronic devices. Meanwhile, simple, low-cost, and substrate-versatile fabrication is also essential toward real applications of such coatings. Herein, we developed a substrate-versatile strategy to fabricate robust antireflective and superhydrophobic coatings with excellent self-cleaning property in varied environments, including air and oil and after oil contamination...
September 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28929654/-chemical-studieson-hydrophilic-constituents-of-toad-skin
#5
Shao-Kun Xin, Nan Si, Hong-Jie Wang, Jian Yang, Bo Gao, Xiao-Lu Wei, Hai-Yu Zhao, Bao-Lin Bian
Fifteen compounds were isolated from the toad skin by a combination of various chromatographic methods including macroporous resin, silica gel, ODS and semi-preparative HPLC. Their structures were identified as 4,5-dimethyl-1,3,4,5-tetrahydropyrrolo[4,3,2-de]quinolin-6-ol(1), serotonin(2), N-methyl serotonin(3), O-methyl bufotenine(4), 1,2,3,4-tetrahydro-6-hydroxy-β-carboline(5), O-methylserotonin(6), glycinebetaine(7), caffeine(8), bufotenine(9), shepherdine(10), tryptophan(11), (5-hydroxy-1H-indol-3-yl)acetic acid(12), 5-hydroxy tryptophol(13), 2-methyl-6-hydroxy-1,2,3,4-tetrahydro-β-carboline(14), bufothionine(15)...
October 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28929504/simultaneous-determination-of-serum-propafenone-and-its-metabolites-using-high-performance-liquid-chromatography
#6
Yuki Shirayama, Kosuke Doki, Yukio Sekiguchi, Kazutaka Aonuma, Yukinao Kohda, Masato Homma
Propafenone, a class Ic antiarrhythmic agent, is metabolized to 5-hydroxypropafeone (5-OHP) and N-depropylpropafenone (NDPP). Simultaneous determination of serum propafenone and its metabolites was performed using high-performance liquid chromatography (HPLC) equipped with a conventional octadecylsilyl silica column and ultraviolet detector. The wavelength was set at 250 nm. Propafenone and its metabolites in the serum were extracted using diethyl ether. The mobile phase solution, comprising 1-pentanesulfonic acid sodium salt (0...
September 19, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28929137/bioinspired-bright-noniridescent-photonic-melanin-supraballs
#7
Ming Xiao, Ziying Hu, Zhao Wang, Yiwen Li, Alejandro Diaz Tormo, Nicolas Le Thomas, Boxiang Wang, Nathan C Gianneschi, Matthew D Shawkey, Ali Dhinojwala
Structural colors enable the creation of a spectrum of nonfading colors without pigments, potentially replacing toxic metal oxides and conjugated organic pigments. However, significant challenges remain to achieve the contrast needed for a complete gamut of colors and a scalable process for industrial application. We demonstrate a feasible solution for producing structural colors inspired by bird feathers. We have designed core-shell nanoparticles using high-refractive index (RI) (~1.74) melanin cores and low-RI (~1...
September 2017: Science Advances
https://www.readbyqxmd.com/read/28928359/hydrodeoxygenation-of-water-insoluble-bio-oil-to-alkanes-using-a-highly-dispersed-pd-mo-catalyst
#8
Haohong Duan, Juncai Dong, Xianrui Gu, Yung-Kang Peng, Wenxing Chen, Titipong Issariyakul, William K Myers, Meng-Jung Li, Ni Yi, Alexander F R Kilpatrick, Yu Wang, Xusheng Zheng, Shufang Ji, Qian Wang, Junting Feng, Dongliang Chen, Yadong Li, Jean-Charles Buffet, Haichao Liu, Shik Chi Edman Tsang, Dermot O'Hare
Bio-oil, produced by the destructive distillation of cheap and renewable lignocellulosic biomass, contains high energy density oligomers in the water-insoluble fraction that can be utilized for diesel and valuable fine chemicals productions. Here, we show an efficient hydrodeoxygenation catalyst that combines highly dispersed palladium and ultrafine molybdenum phosphate nanoparticles on silica. Using phenol as a model substrate this catalyst is 100% effective and 97.5% selective for hydrodeoxygenation to cyclohexane under mild conditions in a batch reaction; this catalyst also demonstrates regeneration ability in long-term continuous flow tests...
September 19, 2017: Nature Communications
https://www.readbyqxmd.com/read/28927930/biodegradable-and-adjustable-sol-gel-glass-based-hybrid-scaffolds-from-multi-armed-oligomeric-building-blocks
#9
Christian Kascholke, Stephan Hendrikx, Tobias Flath, Dzmitry Kuzmenka, Hans-Martin Dörfler, Dirk Schumann, Mathias Gressenbuch, F Peter Schulze, Michaela Schulz-Siegmund, Michael C Hacker
Biodegradability is a crucial characteristic to improve the clinical potential of sol-gel-derived glass materials. To this end, a set of degradable organic/inorganic class II hybrids from a tetraethoxysilane(TEOS)-derived silica sol and oligovalent cross-linker oligomers containing oligo(D,L-lactide) domains was developed and characterized. A series of 18 oligomers (Mn: 1100-3200 Da) with different degrees of ethoxylation and varying length of oligoester units was established and chemical composition was determined...
September 16, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28927600/a-ph-responsive-emulsion-stabilized-by-alginate-grafted-anisotropic-silica-and-its-application-in-the-controlled-release-of-%C3%AE-cyhalothrin
#10
Kai Chen, Gaobo Yu, Furui He, Qingfeng Zhou, Dunchao Xiao, Jiacheng Li, Yuhong Feng
Alginate (Alg) was grafted on the surface of anisotropic silica (SiO2-x) via the Ugi reaction (Alg-SiO2-1, Alg-SiO2-2, and Alg-SiO2-4). Compared with pristine SiO2-x, modified SiO2-x is more sensitive to pH. Three stable liquid paraffin-in-water emulsions were prepared with Alg-SiO2-1, Alg-SiO2-2, and Alg-SiO2-4. Alg-SiO2-2 exhibited satisfactory emulsification ability. The emulsions became more stable as emulsion pH varied from 2.0 to 6.2 because of polymer chain interactions that led to the formation of a three-dimensional network...
November 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28927166/experimental-evaluation-of-respirable-dust-and-crystalline-silica-controls-during-simulated-performance-of-stone-countertop-fabrication-tasks-with-powered-hand-tools
#11
David L Johnson, Margaret L Phillips, Chaolong Qi, Anthony T Van, Danielle A Hawley
Objectives: Workers who fabricate stone countertops using hand tools are at risk of silicosis from overexposure to respirable crystalline silica. This study explored the efficacy of simple engineering controls that can be used for dust suppression during use of hand tools by stone countertop fabricators. Methods: Controlled experiments were conducted to measure whether wet methods and on-tool local exhaust ventilation (LEV) reduced respirable dust (RD) exposures during use of various powered hand tools on quartz-rich engineered stone...
July 1, 2017: Annals of Work Exposures and Health
https://www.readbyqxmd.com/read/28927008/can-more-nanoparticles-induce-larger-viscosities-of-nanoparticle-enhanced-wormlike-micellar-system-newms
#12
Mingwei Zhao, Yue Zhang, Chenwei Zou, Caili Dai, Mingwei Gao, Yuyang Li, Wenjiao Lv, Jianfeng Jiang, Yining Wu
There have been many reports about the thickening ability of nanoparticles on the wormlike micelles in the recent years. Through the addition of nanoparticles, the viscosity of wormlike micelles can be increased. There still exists a doubt: can viscosity be increased further by adding more nanoparticles? To answer this issue, in this work, the effects of silica nanoparticles and temperature on the nanoparticles-enhanced wormlike micellar system (NEWMS) were studied. The typical wormlike micelles (wormlike micelles) are prepared by 50 mM cetyltrimethyl ammonium bromide (CTAB) and 60 mM sodium salicylate (NaSal)...
September 18, 2017: Materials
https://www.readbyqxmd.com/read/28926704/chromatographic-properties-of-minimal-aspect-ratio-monolithic-silica-columns
#13
Takeshi Hara, Shunta Futagami, Wim De Malsche, Sebastiaan Eeltink, Herman Terryn, Gino V Baron, Gert Desmet
We report on a study wherein we synthesized TMOS-based silica monolithic skeletons in capillaries with an i.d. of 5 and 10 μm to produce skeleton structures with very low capillary-to-domain size aspect-ratios. These structures include the absolute minimal aspect-ratio case of a monolithic structure whose cross-section only contains a single node point. With domain-sized based reduced plate heights running as low as hmin = 1.3-1.5 for retained coumarin dyes providing a retention factor of k = 0.6-1.0, the study confirms the classic observation that ultra-low aspect ratio columns generate a markedly lower dispersion than columns with a larger aspect ratio made in the past by Knox, Jorgenson and Kennedy for the packed bed of spheres, but now for silica monoliths...
September 19, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28926062/selectivity-of-solid-phase-extraction-for-dissolved-organic-matter-in-the-hypersaline%C3%A2-da-qaidam-lake-china
#14
Keli Yang, Yaoling Zhang, Yaping Dong, Wu Li
Dissolved organic matter (DOM) was isolated from the hypersaline Da Qaidam Lake using solid-phase extraction (SPE) methods with five different adsorbents: ENVI-Carb (non-porous graphitized carbon), HLB, PPL, and XAD-8 (polymer based), and ENVI-18 (silica based). Structure-selective assessments of SPE-DOM isolated using the different adsorbents were conducted using a combination of complementary analysis techniques, including dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) analysis, as well as elemental analysis, Fourier transformed infrared spectroscopy (FTIR), (1)H nuclear magnetic resonance ((1)H NMR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS)...
September 19, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28925677/polypeptide-composite-particle-assisted-organization-of-%C3%AF-conjugated-polymers-into-highly-crystalline-coffee-stains
#15
Cornelia Rosu, Ping-Hsun Chu, Christopher J Tassone, Katherine Park, Paul L Balding, Jung Ok Park, Mohan Srinivasarao, Elsa Reichmanis
We demonstrate that homopolypeptides covalently tethered to anisotropically shaped silica particles induce crystalline ordering of representative semiconducting polymers. Films drop-cast from chloroform dispersions of poly(γ-stearyl-l-glutamate) (PSLG) composite particles and poly(3-hexythiophene) (P3HT) led to highly ordered crystalline structures of P3HT. Hydrophobic-hydrophobic interactions between the alkyl side chains of P3HT and PSLG were the main driving force for P3HT chain ordering into the crystalline assemblies...
September 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28925158/-study-on-chemical-constituents-of-seeds-of-croton-tiglium-and-their-cytotoxicities
#16
Hai-Guo Su, Huai Yang, Chun-Wang Meng, Cheng Peng, Li Guo, Ou Dai
Seven compounds were isolated from the seeds of Croton tiglium by preparative TLC, semi-preparative HPLC, and column chromatography over silica gel, MCI, and Sephadex LH-20, etc. Their structures were elucidated by spectroscopic data analysis as bis(2,3-dihydroxypropyl) nonanedioate (1), 12-O-(α-methyl)butyrylphorbol-13-decanoate (2), 12-O-tiglylphorbol-13-decanoate (3), (9S,10R,11E,13R)-9,10,13-trihydroxyoctadec-11-enoic acid (4), methyl (9S,10R,11E,13R)-9,10,13-trihydroxyoctadec-11-enoate (5), 4(1H)-quinolinone (6), and 5-hydroxy-2-pyridinemethanol (7)...
October 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28925108/development-of-a-reliable-and-reproducible-phantom-manufacturing-method-using-silica-microspheres-in-silicone
#17
Charlotte Maughan Jones, Peter R Munro
Optically scattering phantoms composed of silica microspheres embedded in an optically clear silicone matrix were manufactured using a previously developed method. Multiple problems, such as sphere aggregation, adsorption to the cast, and silicone shrinkage, were, however, frequently encountered. Solutions to these problems were developed and an improved method, incorporating these solutions, is presented. The improved method offers excellent reliability and reproducibility for creating phantoms with uniform scattering coefficient...
September 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28923746/diphenyl-diselenide-immobilized-on-magnetic-nanoparticles-a-novel-and-retrievable-heterogeneous-catalyst-in-the-oxidation-of-aldehydes-under-mild-and-green-conditions
#18
Yalda Rangraz, Firouzeh Nemati, Ali Elhampour
In the present study diselenide stabilized on silica coated Fe3O4 magnetic nano particles asa novel, highly efficient and magnetically retrievable heterogeneous catalyst was designed, synthesized and introduced. Full characterization of the newly prepared magnetic nanocatalyst was authenticated using several physico-chemical characterization techniques such as Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction patterns (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM)...
September 8, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28922574/super-resolution-microscopy-unveils-dynamic-heterogeneities-in-nanoparticle-protein-corona
#19
Natalia Feiner-Gracia, Michaela Beck, Sílvia Pujals, Sébastien Tosi, Tamoghna Mandal, Christian Buske, Mika Linden, Lorenzo Albertazzi
The adsorption of serum proteins, leading to the formation of a biomolecular corona, is a key determinant of the biological identity of nanoparticles in vivo. Therefore, gaining knowledge on the formation, composition, and temporal evolution of the corona is of utmost importance for the development of nanoparticle-based therapies. Here, it is shown that the use of super-resolution optical microscopy enables the imaging of the protein corona on mesoporous silica nanoparticles with single protein sensitivity...
September 18, 2017: Small
https://www.readbyqxmd.com/read/28921951/a-spring-in-performance-silica-nanosprings-boost-enzyme-immobilization-in-microfluidic-channels
#20
Donya Valikhani, Juan M Bolivar, Martina Viefhues, David Nevil Mcilroy, Elwin Xander Vrouwe, Bernd Nidetzky
Enzyme microreactors are important tools of miniaturized analytics and have promising applications in continuous biomanufacturing. Fundamental problem of their design is that plain microchannels without extensive static internals, or packings, offer limited exposed surface area for immobilizing the enzyme. To boost the immobilization in a manner broadly applicable to enzymes, we coated borosilicate microchannels with silica nanosprings and attached the enzyme, sucrose phosphorylase, via a silica-binding module genetically fused to it...
September 18, 2017: ACS Applied Materials & Interfaces
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