Search results for "radical"
showing 10 items of 1401 documents
Garantías legales del concepto de privacidad: Entre el derecho al olvido y el nuevo reglamento europeo de protección de datos
2018
The operation of new technologies and the supply of digital goods involves for users to disclose their personal data. The market data is already a reality with the danger that this entails for the privacy of citizens. The new General Data Protection Regulation has created a new legal framework that aims to radically change the current model, giving users greater powers to control their data. A good example of this is the express statement, and for the first time, of the right to be forgotten, which allows citizens to digitally erase their data when other fundamental rights are endangered.
Improved bioaccessibility and antioxidant capacity of olive leaf ( Olea europaea L.) polyphenols through biosorption on Saccharomyces cerevisiae
2016
Abstract Olive ( Olea europaea L.) leaves (OL) are natural by-products that can be used as an advantageous rich source of bioactive compounds, especially polyphenols. This study investigated the potential use of Saccharomyces cerevisiae as a new carrier of OL antioxidants and a means to protect their bioactivity during simulated gastrointestinal digestion. The biosorption on S. cerevisiae allowed the recovery of 25.17 mg/g and 49.40% of the polyphenols from olive leaf (var. Chemlali ) infusions. Both infusions and suspensions before and after biosorption were analyzed for total soluble polyphenols and total antioxidant capacity (oxygen radical absorbance capacity (ORAC) and trolox equivalen…
Asymptotic potentials and rate constants in the adiabatic capture centrifugal sudden approximation for X + OH(X-2 Pi) -> OX + H(S-2) reactions where …
2012
International audience; New long-range multipolar coefficients for the X + OH(X-2 Pi) interactions, where X = O(P-3), S(P-3) and N(S-4), are given here. They have been evaluated on the basis or monomer properties of the atoms and OH such as the dipole and quadrupole moments, and the static and dynamic polarizabilities. Each matrix element of the 18 x 18 (8 x 8 for N + OH) quasi-degenerate asymptotic potentials has been built up by means of the perturbation theory up to second order including or not the fine-structure of O, S and OH. The adiabatic potentials, obtained after diagonalization of the full matrix, show many crossings and complex behaviors near the asymptotes. Using the entrance c…
FREE RADICAL THEORY OF FRAILTY: MOLECULAR MECHANISMS OF FRAILTY RESULTING FROM OXIDATIVE STRESS
2018
The free radical theory of ageing provided an intellectual framework for many laboratories working on ageing. However, experimental and clinical evidence showing that high doses of antioxidants did not have an effect on ageing or on age-associated diseases, cast doubts on the validity of this theory. Data from our own laboratory showed that oxidative stress does not correlate with age, especially in the geriatric population, but rather with the frailty state. This has led us to postulate the free radical theory of frailty in which frailty is associated with oxidative stress, but age itself is not. Superoxide dismutase deficient mice are more frail than controls. But more importantly, we obs…
Double Thermoresponsive Block Copolymers Featuring a Biotin End Group
2010
A poly(oligo(ethylene glycol) monomethyl ether methacrylate)-block-poly(N-isopropyl methacrylamide) (POEGMA-b-PNIPMAM) block copolymer with a biotin end group on the PNIPMAM block as a biotarget was synthesized as a model system for temperature-controlled polymer immobilization. The synthesis was based on RAFT polymerization followed by postpolymerization modification of an activated ester precursor block and an exchange of the dithioester end group within one step. NMR, differential scanning calorimetry (DSC), dynamic light scattering (DLS), and turbidimetry measurements were performed to investigate the stimulus-responsive properties. The double thermoresponsive POEGMA-b-PNIPMAM with biot…
Darstellung und polymerisation von diestern aus 2,2′-methylendiphenolen und acryl-, methacryl- bzw. Crotonsäure
1984
Several mono- and diesters of four selected 2,2′-methylenediphenols with acrylic, methacrylic, and crotonic acid were synthesized for the first time. Special emphasis was paid to the preparation of diesters with two different acyl groups which could be obtained via the corresponding monoesters. The radical polymerization of these esters with AIBN (mainly in benzene) gave insoluble (crosslinked) products from dimethacrylates and soluble (linear) polymers from mixed diesters with methacrylic and crotonic acid, while the dicrotonates are not reactive.
Controlled synthesis of poly(acetone oxime acrylate) as a new reactive polymer: Stimuli-responsive reactive copolymers
2007
Abstract Acetone oxime acrylate has been synthesized as a new active ester monomer. Free radical polymerization yielded a reactive polymer soluble in various organic solvents, such as chloroform, dioxane, DMSO, acetone, methanol, dichloromethane, DMF, and ethanol. Controlled radical polymerization of acetone oxime acrylate was successfully conducted using the RAFT, NMP and Iniferter method. Partly polymer analogous reaction with N-isopropylamine resulted in the reactive copolymer poly(N-isopropylacrylamide-co-acetone oxime acrylate), which featured a lower critical solution temperature (LCST) of 61 °C in water. Further, the reactivity of the copolymer was exemplary proven by complete reacti…
Multi-Arm Star Polyglycerol-block-poly(tert-butyl acrylate) and the Respective Multi-Arm Poly(acrylic acid) Stars
2006
Well-defined multi-arm star block copolymers, polyglycerol-block-poly(tert-butyl acrylate) (PG-b-PtBA), with average arm-numbers of 17, 27, 36, 66 and 90 arms, respectively, have been prepared by atom transfer radical polymerization (ATRP) of tBA in acetone, using a core-first strategy. After hydrolysis with excess concentrated HCl in refluxing dioxane, full hydrolysis of the tert-butyl ester groups was achieved, resulting in multi-arm star polyelectrolytes, polyglycerol-block-poly(acrylic acid) (PG-b-PAA). The hyperbranched macroinitiators employed were prepared on the basis of hyperbranched polyglycerols via esterification with 2-bromoisobutyryl bromide. Both CuBr/PMDETA and CuBr/Me 6 TRE…
Total synthesis and biological evaluation of the natural product (−)-cyclonerodiol, a new inhibitor of IL-4 signaling
2014
In a screening program of natural compounds from fungi, the known cyclopentanoid sesquiterpene (-)-cyclonerodiol was identified as a specific inhibitor of the IL-4 induced STAT6 signaling pathway (IC50 = 9.7 μM) which is required for the differentiation of naive CD4 T cells to T helper type 2 (Th2) lymphocytes. As many allergic conditions, including allergic asthma and atopic diseases, are driven by an excessive Th2 response, STAT6 is a promising target for the development of new therapeutics. The compound was synthesized in six steps from (-)-linalool using an epoxide radical cyclization as the key step.
Control of the production of oxygen intermediates of human polymorphonuclear leukocytes and monocytes by beta-adrenergic receptors.
1983
The control by beta-adrenergic receptors of the production of oxygen radicals by zymosan-stimulated human polymorphonuclear leukocytes (PMN) and monocytes (M phi) was studied in vitro by means of chemiluminescence. In addition we asked whether PMN and M phi exhibit differential sensitivity to beta-adrenergic stimulation. For beta-adrenergic stimulation we applied fenoterol ranging from 10(-5) to 10(-9) M x 2.7. We found a dose-dependent suppression of the production of oxygen radicals, the ID50 being approximately 10(-6) M both for PMN and M phi. By assessment of lactic dehydrogenase release a cytotoxic effect of the drug could be ruled out. When incubated together with the beta-adrenergic …