Search results for "PORP"
showing 10 items of 567 documents
Oxidative C-N fusion of pyridinyl-substituted porphyrins.
2018
International audience; The mild (electro) chemical oxidation of pyridin-2-ylthio-meso substituted Ni(II) porphyrins affords C-N fused cationic and dicationic pyridinium-based derivatives. These porphyrins are fully characterized and the molecular structure of one of them was confirmed by X-ray crystallography. A mechanism for the intramolecular oxidative C-N coupling is proposed based on theoretical calculations and cyclic voltammetry analyses.
Highly stable and porous porphyrin-based zirconium and hafnium phosphonates – electron crystallography as an important tool for structure elucidation
2018
The Ni-metallated porphyrin-based tetraphosphonic acid (Ni-tetra(4-phosphonophenyl)porphyrin, Ni-H8TPPP) was used for the synthesis of highly porous metal phosphonates containing the tetravalent cations Zr4+ and Hf4+. The compounds were thoroughly characterized regarding their sorption properties towards N2 and H2O as well as thermal and chemical stability. During the synthesis optimization the reaction time could be substantially decreased under stirring from 24 to 3 h in glass vials. M-CAU-30, [M2(Ni-H2TPPP)(OH/F)2]·H2O (M = Zr, Hf) shows exceptionally high specific surface areas for metal phosphonates of aBET = 1070 and 1030 m2 g-1 for Zr- and Hf-CAU-30, respectively, which are very clos…
Ausu operāciju analīze “Headline” klīnikā, kas veiktas laika posmā no 2011. gada janvāra līdz 2019. gada decembra mēnesim
2020
Attīstoties ambulatorajai aprūpei otorinolaringoloģijā ir svarīgi izvērtēt operāciju kvalitāti, pielietotā materiāla un dzirdes uzlabošanās efektivitāti. Šīs retrospektīvais pētījums sniedz ieskatu par ausu operāciju veidiem, revīzijas operāciju nepieciešamību atkarībā no operāciju tehnikas un izmantotā materiāla. Darba mērķis: Veikt ausu operāciju rezultātu analīzi pacientiem, kam veiktas operācijas “Headline” privātklīnikā laika posmā no 2011. gada janvāra līdz 2019. gada decembra mēnesim. Darba uzdevumi: 1. Izvērtēt pacientu vājdzirdību slieksni pēc gaisa vadīšanas sliekšņa (AC) no dzirdes kauliņu rekonstrukcijas pacientu audiometrijām, kas veiktas pirms un pēc operācijas. Noskaidrot ope…
An in vitro model to study cellular photosensitizer uptake and photodynamic dose-response relationships of tumor cells
1993
Cellular fluorescence intensity (CFI) after incubation with varying concentrations of the photosensitizer Photofrin and the photodynamically induced dose-response relationships of hamster melanoma cells (A-MEL-3) were studied in a recently developed in vitro model. After administration of Photofrin to the extracellular serum-free medium, CFI was evaluated by flow cytometry together with constantly fluorescing latex particles used as a reference. After 5 min, 50% of maximal CFI was found, and after 60 min CFI was maximal. No further increase was obtained during the exposure to Photofrin over the incubation period of 4 h. During this plateau phase, CFI was significantly related to the concent…
Combination of Autofluorescence imaging and salivary protoporphyrin in Oral precancerous and cancerous lesions: non-invasive tools
2014
Background: Normal and cancerous tissues have distinct auto-fluorescence properties because of differences in their biophysical and biochemical agents. Scientific evidences related to diagnostic fluorescence imaging for detection of oral precancerous and cancerous lesions are very limited. Objectives: The aim of this study was to find out potential relationships between serum, salivary and tissue protoporphyrin IX ( PX) levels in subjects with or without oral precancerous and cancerous lesions. Also, to find out diagnostic value of fluorescence imaging (VELscope® system, LED Dental Inc., White Rock, B.C.) and salivary protoporphyrin IX (PX) in oral precancerous and cancerous lesions. Furthe…
Periopathogenic bacteria in dental plaque of Congolese patients with periodontitis : a pilot study
2018
Background Periopathogenic bacteria play an important role in the etiology of periodontal disease. At present, no study screening for periopathogens in the DR Congo was carried out. The aim of this pilot study was to investigate the prevalence of five periopathogens in Congolese patients with periodontitis and to determine the association between these bacteria. Material and Methods Twelve patients (eight women and four men) with a mean age of 45 ± 19 years from those consulted in dental services of two medical centers of Kinshasa from April 2017 to October 2017 were included. Full mouth examination was registered, the probing pocket depth and clinical attachment level were assessed at six …
Periodontitis, blood lipids and lipoproteins
2014
Periodontitis, one of the most common chronic infections in adults, is characterized by the accumulation of dental plaque and infection by gram-negative pathogens bacteria, which further lead to the destruction of periodontal tissues. A relationship between chronic periodontitis and abnormalities in lipid and/or lipoprotein metabolism is not well understood yet. Periodontitis is associated with elevated pro-atherogenic plasma-lipids, including small dense LDL, while oxidized LDL may act as inflammatory stimulant in periodontitis. Periodontal pathogens may directly modify lipoprotein, including protective characteristics of HDL and contribute to development of metabolic syndrome, Type 2 diab…
Vasodilator Effects of Liriodenine and Norushinsunine, Two Aporphine Alkaloids Isolated from <i>Annona cherimolia,</i>in Rat Aorta
1995
The effect of two aporphines, liriodenine and norushinsunine, isolated from Annona cherimolia, were studied in the rat aorta in order to examine their mechanism of action. Both alkaloids (10–7–10–4 mol/l) showed relaxant effects on the contractions elicited by 10–6 mol/l noradrenaline (NA) or 80 mmol/l KC1, but, while liriodenine showed a nonspecific relaxant action on both spasmogens, norushinsunine was more potent on KC1-induced contraction. In Ca2+-free medium, both alkaloids (0.1 mmol/l) inhibited the responses elicited by NA, but not those elicited by caffeine. This inhibitory action occurred when the alkaloids were present during the release of the Ca2+ internal stores or during the r…
New potential bimodal imaging contrast agents based on DOTA-like and porphyrin macrocycles
2011
A bifunctional chelator featuring (DO3A-AM)-Porphyrin units has been prepared. The high-field relaxivity of the Gd complex is similar to those of currently available contrast agents clearly showing that the first coordination sphere remains identical to the parent molecule [Gd(DO3A-AM)(H2O)], with one coordinated water molecule.
8-NH2-Boldine, an Antagonist of α1Aand α1BAdrenoceptors without Affinity for the α1DSubtype: Structural Requirements for Aporphines at α1-Adrenocepto…
2005
Structure-activity analysis of 21 aporphine derivatives was performed by examining their affinities for cloned human alpha (1A), alpha (1B) and alpha (1D) adrenoceptors (AR) using membranes prepared from rat-1 fibroblasts stably expressing each alpha (1)-AR subtype. All the compounds tested competed for [ (125)I]-HEAT binding with steep and monophasic curves. The most interesting compound was 8-NH (2)-boldine, which retains the selective affinity for alpha(1A)-AR (pKi = 6.37 +/- 0.21) vs. alpha(1B)-AR (pKi = 5.53 +/- 0.11) exhibited by 1,2,9,10-tetraoxygenated aporphines, but shows low affinity for alpha(1D)-AR (pKi < 2.5). Binding studies on native adrenoceptors present in rat cerebral cor…