Search results for "beta"
showing 10 items of 3374 documents
[3+2]‐Cycloadditions of N ‐Cyano Sulfoximines with 1,3‐Dipoles
2020
Involving the cyano group of N‐cyano sulfoximines in [3+2]‐cycloaddition reactions with 1,3‐dipoles provides practical routes for the construction of 5‐membered heterocycles bearing sulfoximinoyl moieties. An ytterbium‐catalyzed cycloaddition utilizing hydrazonoyl chlorides was developed, as well as a reaction involving imidoyl chlorides proceeding without the aid of a catalyst. Following these protocols, a range of sulfoximines with N‐1,2,4‐triazolyl and N‐1,2,4‐oxadiazolyl substituents was prepared. peerReviewed
Antioxidant activities of prickly pear ( Opuntia ficus indica) fruits and its betalains: betanin and indicaxanthin.
2004
Phytochemicals and phytomedicines are now an expanding research fields. A great number of active agents occurring in plants and herbs have been discovered, which is fundamental to find a rationale for the health effects of these herbs, in many cases used for centuries as traditional remedies. The knowledge of the mechanisms and molecular basis of their action is the final objective to understand the mode of action of the discovered principles. Studies on the bioactivity of cactus pear are very recent and results obtained so far, while exciting, now generate new questions. In vivo studies on healthy humans showed a strong protection of the body antioxidant system, and a marked reduction of p…
Uptake of Betanin and Indicaxanthin by Caco-2 cell monolayer.
2009
Transepithelial transport of betalainic phytochemicals in Caco-2 cell monolayers.
2010
Anti-oxidant and anti-inflammatory properties of betalains from Cactus Pear
2004
Anti-oxidant and anti-inflammatory properties of Betalains from Cactus Pear. C. Gentile1, A. Marconi1, M. A. Livrea2, G. Uzan1, P. D’Alessio1. 1 Inserm U602, Paris, France. 2 Dip. Farmacochimico, Tossicologico e Biologico, Università Palermo, Italy. Betalains of phytochemical origin, known as potent radical-scavengers in chemical and biological systems, have been tested in a model of inflammation. New phytochemicals are continuously inspected for potential pharmacological applications. The red betanin and the yellow indicaxanthin have recently been isolated and characterized from Cactus Pear. Reactive Oxygen Species may be toxic or display a regulatory character. During the inflammation rea…
Energy conversion efficiency in betavoltaic cells based on the diamond Schottky diode with a thin drift layer
2020
The HPHT diamond Schottky diode was assembled as a Metal/Intrinsic/p-doped structure betavoltaic cell (BC) with a very thin (1 μm) drift layer and tested under 5–30 keV electron beam irradiation using a scanning electron microscope (SEM). The effect of the β-radiation energy and the backscattering of electrons on the energy conversion was studied. From the results obtained, it is shown that, the efficiency of the investigated BC increases from 1.01 to 3.75% with the decrease of β-particle energy from 30 to 5 keV due to an increase of the electron beam absorption in a thin drift layer. Maximum efficiency is achieved when the electron beam energy is close to the average β-decay energy of 3H. …
Antioxidative effects of cactus pear (Opuntia ficus indica, L. Mill.) fruits from Sicily and bioavailability of betalain components in healthy humans
2009
Aerobic life is characterised by a steady formation of pro-oxidants, which is approximately balanced by antioxidant defense systems. When cell’s capacity to protect itself fails, oxidative stress occurs. Because of bioactive components vegetables are now considered helpful in preventing chronic pathologies in which oxidative damage is an important etiologic factor. Cactus pear (Opuntia ficus-indica) fruit contains substantial amounts of vitamin C, biothiols, and taurine, and redox-active betalain pigments. It has been shown that a short-term supplementation (500 g fruit pulp daily, 2 wk) positively affected the body’s redox balance, decreased lipid oxidation, and improved antioxidant status…
Experimental Inhibition of Fibrillogenesis and Neurotoxicity by amyloid-beta (Aβ) and Other Disease-Related Peptides/Proteins by Plant Extracts and H…
2012
Amyloid-β (Aβ) fibrillogenesis and associated cyto/neurotoxicity are major pathological events and hallmarks in diseases such as Alzheimer’s disease (AD). The understanding of Aβ molecular pathogenesis is currently a pharmacological target for rational drug design and discovery based on reduction of Aβ generation, inhibition of Aβ fibrillogenesis and aggregation, enhancement of Aβ clearance and amelioration of associated cytotoxicity. Molecular mechanisms for other amyloidoses, such as transthyretin amyloidosis, AL-amyloidosis, as well as α-synuclein and prion protein are also pharmacological targets for current drug therapy, design and discovery. We report on natural herbal compounds and e…
A search for beta-lactamase in chlamydiae, mycoplasmas, planctomycetes, and cyanelles: bacteria and bacterial descendants at different phylogenetic p…
2000
Bacteria from different phylogenetic positions such as chlamydiae, mycoplasmas, planctomycetes and also endosymbiotic murein-containing cyanelles were investigated for the production of beta-lactamases. No beta-lactamase activity was found in bacteria lacking murein such as Chlamydia pneumoniae, Mycoplasma pneumoniae, Pirellula marina and Planctomyces maris. In the murein-containing cyanelles of Cyanophora paradoxa no beta-lactamase activity could be detected.
Relationship between HLA I surface expression and different cytopathic effects produced after herpes simplex virus infection in vitro.
1992
In the present study, we investigated the effects of herpes simplex virus (HSV) infection on the expression of HLA class I antigens and beta 2-microglobulin in human fibroblasts. The mRNA abundance for HLA class I was shown to be strongly reduced after infection with HSV strains either producing cell rounding or fusion from within (FFWI), however, HLA class I expression on the surface of cells is strongly reduced only after appearance of FFWI. Using a ts mutant (ts 78R) or CyA in combination with a fusion from without (FFWO) inducing strain of HSV, this loss of HLA class I antigens is assumed to be correlated to the rearrangement of the cell membrane during the fusion process itself as a la…