Search results for "Gel"

Biochemical analysis of class II antigens. Identification of a two- and a three-polypeptide chain complex of I-A locus equivalent molecules in the ra…

1983

The polypeptide chain composition of class II antigens from LEW rat spleen cells was studied utilizing cross-reactive mouse alloantiserum A. TH anti-A.TL (specificity anti-Iak) and the monoclonal antibodies MRC-OX6 and MRC-OX3 for immunoprecipitation. Two-dimensional gel mapping of A. TH anti-A. TL immunoprecipitates revealed that, as in the mouse, two groups of class II antigens exist corresponding to I-A and I-E locus equivalent structures. In the absence of reducing agents three monomeric chains α, 36 kDa (p36); γ, 33 kDa (p33); and β, 23 kDa (p23), were detected for I-A equivalent antigens, whereas I-E equivalent molecules separated into five monomeric chains: α, 37 kDa (p37); γ, 33 kDa…

Preferential solvation of poly(methyl methacrylate) and a bisphenol A diglycidyl ether by size-exclusion chromatography

2004

The preferential adsorption coefficient, lambda, of poly(methyl methacrylate), PMMA, in solutions formed by an epoxy resin in tetrahydrofuran (THF), was studied by size-exclusion chromatography (SEC). Only PMMA of lowest molar mass was preferentially solvated by epoxy but at low concentrations of epoxy in the mixture. At higher epoxy content PMMA was preferentially solvated by THF. A simultaneous and competitive solvation between the specific interactions PMMA-epoxy and the self association of epoxy at high concentrations would be the responsible of this inversion point. The more compacted coil of PMMA of higher molecular weights in solution could explain the lack of interaction of these po…

Influence of Physicochemical Interactions between Amylose and Aroma Compounds on the Retention of Aroma in Food-like Matrices

2002

In food matrices, where starch is often used as a gelling or texturing agent, the occurrence of amylose-aroma complexes and their effect on the release of aroma compounds are difficult to determine. Indeed, thick or gelled systems are known to reduce the diffusion rate of flavor molecules, resulting in an increase of retention. Moreover, interactions between aroma compounds and matrix components might increase the retention of aroma compounds. The complexing behavior of three aroma compounds with amylose was studied by DSC and X-ray diffraction to determine the relative importance of these two factors. Their interaction properties were different: two of them formed complexes, and the third …

High-performance and ion-exchange chromatography and chromatofocusing of the human uterine progesterone receptor: its application to the identificati…

1984

Two independent lines of evidence were used to identify the human uterine progesterone receptor. First, three differently tritiated progestogens (Org 2058, R 5020, progesterone) were used for reversible labelling of the receptor. Secondly, the highly potent affinity label 21-[3H]dehydro Org 2058 was used to label covalently the steroid-specific binding site of the receptor. The labelled cytosols were chromatographed on a Mono Q high-performance anion-exchange column in the absence or presence of a high molar excess of the respective unlabelled competitor steroids. In the case of 21-[3H]dehydro Org 2058, Org 2058 was used as the unlabelled competitor. After elution with a NaCl gradient, the …

The chemical effects of molecular sol–gel entrapment

2007

Chemical conversions within the cages of doped sol-gel porous oxides take place with unique advantages over reactions in solution as the glassy matrix has tremendous effects on the reactivity of the entrapped molecules. The chemical properties of sol-gel materials can be tailored in an immense range of values and chemists are increasingly achieving control on reactions taking place within these matrices, including crucially important photovoltaics. Highlighting recent major advancements, we show in this tutorial review how this is actually taking place.

From Molecules to Systems: Sol-Gel Microencapsulation in Silica-Based Materials

2010

From Spherical Mesopores to Worm-Shaped Mesopores : Morphology Transition in Titania–Polystyrene-b-poly(ethylene oxide) Composite Films with Increasi…

2013

A morphology transition from spherical mesopores to worm-shaped mesopores within titania block copolymer composite thin films has been observed by varying the sol–gel reaction time from 40 min to 48 h in the four-component templating system of polystyrene-$\mathit{b}$-poly(ethylene oxide) (PS-$\mathit{b}$-PEO), 1,4-dioxane, concentrated HCl, and titanium tetraisopropoxide (TTIP) with a PS-$\mathit{b}$-PEO mass concentration of 0.25 wt.-%. The impact of the sol–gel reaction time on the local structure, long-range lateral structure, and vertical structure of the as-prepared, calcined, and UV-degraded thin films as well as the structural changes in solution have been systematically investigate…

Synthesis of Uvarovite Garnet

1989

A garnet with interesting optical properties is synthesized by means of the ceramic method and the formation of gels. Colloidal silica or tetraethoxysilane (TEOS) is used as a starting reagent in the latter method of synthesis, together with nitrate and chloride salts of the remaining components. Use is made of ultraviolet-visible and infrared spectroscopy techniques and X-ray diffraction in studying the evolution of the system. Formation of the garnet phase at lower temperatures is observed when using the gel methods, as well as the absence of chromates during the process in the samples which contained chlorides.

Nanogel-antimiR-31 conjugates affect colon cancer cells behaviour

2017

Soft and flexible nanogels, produced by electron beam (e-beam) irradiation of poly(N-vinyl pyrrolidone) and acrylic acid, were evaluated as delivery devices of the inhibitor of miR-31, a small RNA molecule with an important role in colorectal cancer (CRC) progression. The nanogel carriers developed possess both carboxyl and primary amino groups; the former were activated to react with the primary amino group present in the purposely-functionalised AntimiR-31. Very high conjugation reaction yields were attained, as well as a remarkable colloidal and storage stability of the conjugates. The ability of these nanoconstructs to be internalized by cells and the specific interaction of conjugated …

Studies on supramolecular gel formation using DOSY NMR

2015

Herein, we present the results obtained from our studies on supramolecular self-assembly and molecular mobility of low-molecular-weight gelators (LMWGs) in organic solvents using pulsed field gradient (PFG) diffusion ordered spectroscopy (DOSY) NMR. A series of concentration-dependent DOSY NMR experiments were performed on selected LMWGs to determine the critical gelation concentration (CGC) as well as to understand the behaviour of the gelator molecules in the gel state. In addition, variable-temperature DOSY NMR experiments were performed to determine the gel-to-sol transition. The PFG NMR experiments performed as a function of gradient strength were further analyzed using monoexponential…