Search results for "fox"
showing 10 items of 607 documents
CCDC 1958348: Experimental Crystal Structure Determination
2020
Related Article: Raphael C. A. Vaz, Isabela O. Esteves, Willian X. C. Oliveira, João Honorato, Felipe T. Martins, Lippy F. Marques, Guilherme L. dos Santos, Ricardo O. Freire, Larissa T. Jesus, Emerson F. Pedroso, Wallace C. Nunes, Miguel Julve, Cynthia L. M. Pereira|2020|Dalton Trans.|49|16106|doi:10.1039/D0DT02497J
Safety assessment of food-contact paper and board using a battery of short-term toxicity tests: European union BIOSAFEPAPER project.
2005
International audience; An European Union (EU)-funded project QLK1-CT-2001-00930 (BIOSAFEPAPER) involves the development, validation and intercalibration of a short-term battery of toxicological tests for the safety assessment of food-contact paper and board. Dissemination of the results to industry, legislators (e.g. DG Consumer Protection, DG Enterprises, DG Research), standardization bodies such as CEN, and consumers will create an agreed risk evaluation procedure. The project involves pre-normative research in order to establish a set of in-vitro cytotoxicity and genotoxicity tests that will be easily adaptable to food-contact fibre-based materials and have endpoints relevant to consume…
N-sulfinyl amines as a nitrogen source in the asymmetric intramolecular aza-Michael reaction: total synthesis of (-)-pinidinol.
2010
N-Sulfinyl amines have been successfully employed as nitrogen nucleophiles for the asymmetric intramolecular aza-Michael reaction. The synthetic strategy involves a cross-metathesis reaction followed by the Michael-type cyclization, either in a base-catalyzed two-step procedure or in a tandem fashion. The developed methodology allows access to chiral substituted pyrrolidines and piperidines bearing one or two stereocenters and it has been applied to the synthesis of the piperidine alkaloid (-)-pinidinol.
Zur Stereochemie der Oxidation chiraler, tertiärer Phosphine mit Dimethylsulfoxid
1976
Es wird uber den sterischen Verlauf der Oxidation der optisch aktiven, tertiaren Phosphine 3 and 4 mit Dimethylsulfoxid berichtet. Diese Umsetzung verlauft nur in Gegenwart elektrophiler Katalysatoren (Tabelle 1). Je nach Art and Menge des Katalysators zeigt die Stereochemie der Reaktion entweder uberwiegende Inversion oder Retention der Konfiguration am Phosphor an (Tabellen 2, 3); in einigen Fallen wird jedoch fast vollstandige Racemisierung beobachtet (Tabelle3). Auf der Grundlage dieser stereochemischen Resultate werden mogliche Mechanismen fur diese Umsetzung diskutiert. The Sterochemistry of the Oxidation of Chiral Tertiary Phosphines by Means of Dimethyl Sulfoxide The steric course o…
Dioxomolybdenum(VI) complexes of hydrazone phenolate ligands - syntheses and activities in catalytic oxidation reactions
2021
Abstract The new cis-dioxomolybdenum (VI) complexes [MoO2(L2)(H2O)] (2) and [MoO2(L3)(H2O)] (3) containing the tridentate hydrazone-based ligands (H2L2 = N'-(3,5-di-tert-butyl-2-hydroxybenzylidene)-4-methylbenzohydrazide and H2L3 = N'-(2-hydroxybenzylidene)-2-(hydroxyimino)propanehydrazide) have been synthesized and characterized via IR, 1H and 13C NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction analysis. The catalytic activities of complexes 2 and 3, and the analogous known complex [MoO2(L1)(H2O)] (1) (H2L1 = N'-(2-hydroxybenzylidene)-4-methylbenzohydrazide) have been evaluated for various oxidation reactions, viz. oxygen atom transfer from dimethyl sulfoxide to t…
Freezing without surrounding cryomedium preserves the endothelium and its function in human internal mammary arteries
2005
Abstract Purpose Cryopreserved human blood vessels may become important tools in bypass surgery. Optimal cryopreservation of an arterial graft should, therefore, preserve both histological and physiological characteristics of smooth muscle and endothelium comparable to the unfrozen artery. Methods Rings from human internal mammary arteries (IMA) were investigated in vitro either unfrozen or after immersion into a cryomedium (RPMI 1640 containing 1.8 M Me2SO and 0.1 M sucrose) and cryostorage with and without surrounding medium. Results In unfrozen IMA, neither contractile responses to noradrenaline (NA) nor endothelium-dependent relaxant responses to acetylcholine (ACH) was modified after e…
Inhibitoren der Korrosion (9) Nachweis der Sekundärinhibitoren bei einigen Sulfoxiden, Triphenylarsinoxid und einigen Sulfoniumsalzen
1971
Die Schutzwerte von Dibenzylsulf-oxyd und strukturell verwandten Ver-bindungen sowie von Triphenylarsin-oxyd werden bestimmt. Sulfoxyde und Arsinoxyde werden (a) nach Protonierung in die kathodischen Bereiche gefuhrt und (b) nach Elektronenaufnahme in die ko-ordinationsfahigen Sekundarinhibitoren (Thioather und tert. Arsine) umgewan-delt. Die Sekundarinhibitoren ziehen entweder auf das Metall auf und unter-drucken dann die Auflosung des Eisens oder werden nicht am Metall fixiert (z. B. Diphenylsulfid) und entfalten dann keinen Schutz. Im Falle des Dibenzyl-sulfoxyds konnen ca. 90% des einge-setzten Dibenzylsulfoxyds als Dibenzyl-sulfid vom Eisen abgelost werden; 16% an unverandertem Dibenzy…
Transforming growth factor induced FoxP3+ regulatory T cells suppress Th1 mediated experimental colitis
2006
Background and aims: The imbalance between effector and regulatory T cells plays a central role in the pathogenesis of inflammatory bowel diseases. In addition to the thymus, CD4+CD25+ regulatory T cells can be induced in the periphery from a population of CD25− T cells by treatment with transforming growth factor β (TGF-β). Here, we analysed the in vivo function of TGF-β induced regulatory T (Ti-Treg) cells in experimental colitis. Methods: Ti-Treg cells were generated in cell culture in the presence or absence of TGF-β and tested for their regulatory potential in experimental colitis using the CD4+CD62L+ T cell transfer model. Results: Ti-Treg cells significantly suppressed Th1 mediated c…
CD4 blockade directly inhibits mouse and human CD4+ T cell functions independent of Foxp3+ Tregs
2013
CD4(+) helper T cells orchestrate protective immunity against pathogens, yet can also induce undesired pathologies including allergies, transplant rejection and autoimmunity. Non-depleting CD4-specific antibodies such as clone YTS177.9 were found to promote long-lasting T cell tolerance in animal models. Thus, CD4 blockade could represent a promising therapeutic approach for human autoimmune diseases. However, the mechanisms underlying anti-CD4-induced tolerance are incompletely resolved. Particularly, multiple immune cells express CD4 including Foxp3(+) regulatory T cells (Tregs) and dendritic cells (DCs), both controlling the activation of CD4(+)Foxp3(-) helper T cells. Utilizing mixed le…
Unexpected Modulation of Recall B and T Cell Responses after Immunization with Rotavirus-like Particles in the Presence of LT-R192G
2010
LT-R192G, a mutant of the thermolabile enterotoxin of E. coli, is a potent adjuvant of immunization. Immune responses are generally analyzed at the end of protocols including at least 2 administrations, but rarely after a prime. To investigate this point, we compared B and T cell responses in mice after one and two intrarectal immunizations with 2/6 rotavirus-like particles (2/6-VLP) and LT-R192G. After a boost, we found, an unexpected lower B cell expansion measured by flow cytometry, despite a secondary antibody response. We then analyzed CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) and CD4(+)CD25(+)Foxp3(-) helper T cells after in vitro (re)stimulation of mesenteric lymph node cells …