9 research outputs found
Potential Antimalarial Activity from Alcoholic Extracts of Wild Salvia palaestina Leaves
Malaria threatens the lives of more than one third of the world’s population; it is a major cause of human
deaths. As a result of the emergence of resistant strains of Plasmodium falciparum to common antimalarial drugs,
the search for new antimalarial drugs is urgently needed. Hemozoin synthesis is an indispensable process for the
parasite survival and is the target of action for several known antimalarial drugs. Sage, Salvia palaestina, is an
aromatic Mediterranean plant. Its leaves have been used over centuries in Palestinian traditional medicine and are
now being investigated for potential antimalarial activity. This study reveals the antimalarial activity of crude and
HPLC separated fractions tested using two methods; the inhibition of ferriprotoporphyrin IX (FP) biomineralization:
semi-quantitative micro-assay used by Deharo and a previously self-developed quantitative in vitro
method. Reversed phase preparative liquid chromatography coupled to Photo Diode Array (PDA) detector was used
to isolate and enrich eight fractions. Three fractions showed promising antimalarial activity. The crude alcoholic
extract of sage leaves seems to have the potential of an antimalarial drug; it prevents β-hematin formation with an
efficiency of about 72% when compared to the standard Chloroquine which gave 93% at comparable concentrations
of chloroquine and extract.The authors are grateful to the European Commission FP7 Programme for their financial support through DEBPAL2 project. We are grateful to Prof. Pierre Lutgen for his helpful discussions and insightful
comments
ФОТОЛИТОГРАФИЯ НА ПЛЕНОЧНЫХ СТРУКТУРАХ КСЕРОГЕЛЬ/ПОРИСТЫЙ АНОДНЫЙ ОКСИД АЛЮМИНИЯ, СФОРМИРОВАННЫХ В РАЗЛИЧНЫХ ЭЛЕКТРОЛИТАХ
The results of study the morphology of the microstructured porous anodic alumina films formed using electrochemical anodization, sol-gel synthesis, photolithography and chemical etching are given. The metal mask was not used in photolithography, because of fabrication the continuous xerogel film. The perspective of application of these structures in planar optoelectronics and photocatalyses are discussed.Приведены результаты исследования морфологии микроструктурированных пленок пористого анодного оксида алюминия, сформированных с применением электрохимического анодирования, золь-гель синтеза, фотолитографии и химического травления. Для выполнения фотолитографии защитная металлическая маска не использовалась за счет формирования сплошной пленки ксерогеля. Обсуждаются перспективы применения таких структур в планарной оптоэлектронике и фотокатализе
PHOTOLITHOGRAPHY OF FILM STRUCTURES XEROGEL/POROUS ANODIC ALUMINA PREPARED IN VARIOUS ELECTROLYTES
The results of study the morphology of the microstructured porous anodic alumina films formed using electrochemical anodization, sol-gel synthesis, photolithography and chemical etching are given. The metal mask was not used in photolithography, because of fabrication the continuous xerogel film. The perspective of application of these structures in planar optoelectronics and photocatalyses are discussed
Photocatalytic destruction of tetracycline hydrochloride on surface of titania dioxide films modified by gold nanoparticles
Films of titania (TiO2) and titania modified with gold nanoparticles (TiO2:Au) were synthesized by a sol–gel method on substrates of glass, aluminum, and aluminum with a layer of nanotextured aluminum or porous anodic alumina. The photocatalytic activity of the samples was investigated in an aqueous solution of the antibiotic tetracycline hydrochloride (TC). TC decomposition was observed in the presence of all samples as a reduction of the solution optical density in the range below 500 nm. Titania was in the crystalline anatase phase with incorporated spherical gold nanoparticles primarily of sizes 1–10 nm after heat treatment at 400°C. Modification of TiO2 films with gold nanoparticles on glass or aluminum substrates did not increase the photocatalytic activity of the samples. It was found that complexes of TC with Al3+ in solution formed only in the presence of gold nanoparticles in the film either in the dark or with UV irradiation
LUMINESCENCE OF ALUMINUM OXIDE FILMS AND PERSPECTIVES OF THEIR APPLICATION IN NANOPHOTONICS PLANAR MICROSTRUCTURES
Various methods of fabrication the luminescent film structures based on porous anodic alumina are analyzed. Manufacturing of luminescent structures by anodizing aluminum in oxalic acid allows observation of visible to the naked eye photoluminescence in the blue range, which remains under ambient conditions for a year or longer. Alumina xerogel prepared in a form of powder demonstrates luminescence in the blue range, which disappears totally after annealing at 800 ºC. Photoluminescence of porous anodic alumina which contains terbium ions in the xerogel of alumina or deposited from solutions of salts formed in the anodic alumina pores has been investigated. The perspectives of formation of planar microstructures using a porous anodic alumina supporting electromagnetic whispering gallery modes are discussed
Photo- and under X-ray luminescence from xerogels embedded in mesoporous anodic alumina
Porous anodic alumina (PAA) films with pore and cell sizes ranging from 170 to 190 and 240
to 270 nm, respectively, have been generated on aluminum and monocrystalline silicon substrates
followed by spin-on sol-gel derived coating with the subsequent thermal treatment producing
microporous xerogel. The distribution of the xerogels corresponding to the chemical contents of
willemite, garnet, titania, alumina, doped with terbium and strontium in PAA was investigated. Most
xerogels, after annealing at 1000 °C, are mainly distributed near the pore bases, leaving much of the
pore volume unfilled
ЛЮМИНЕСЦЕНЦИЯ ПЛЕНОК ОКСИДА АЛЮМИНИЯ И ПЕРСПЕКТИВЫ ИХ ИСПОЛЬЗОВАНИЯ В ПЛАНАРНЫХ МИКРОСТРУКТУРАХ НАНОФОТОНИКИ
Various methods of fabrication the luminescent film structures based on porous anodic alumina are analyzed. Manufacturing of luminescent structures by anodizing aluminum in oxalic acid allows observation of visible to the naked eye photoluminescence in the blue range, which remains under ambient conditions for a year or longer. Alumina xerogel prepared in a form of powder demonstrates luminescence in the blue range, which disappears totally after annealing at 800 ºC. Photoluminescence of porous anodic alumina which contains terbium ions in the xerogel of alumina or deposited from solutions of salts formed in the anodic alumina pores has been investigated. The perspectives of formation of planar microstructures using a porous anodic alumina supporting electromagnetic whispering gallery modes are discussed.Анализируются различные методы формирования люминесцентных пленочных структур на основе анодного оксида алюминия. Изготовление люминесцентных структур анодированием алюминия в щавелевой кислоте позволяет получить видимую невооруженным глазом фотолюминесценцию в синем диапазоне, которая сохраняется при хранении образцов в комнатных условиях в течение года и более. Ксерогель оксида алюминия, приготовленный в виде порошка, также демонстрирует люминесценцию в синем диапазоне, которая исчезает полностью после отжига порошка при температуре 800 ºС. Исследована фотолюминесценция пористого анодного оксида алюминия, содержащего тербий, осажденный из растворов солей или в составе ксерогеля оксида алюминия, сформированного в порах анодного оксида алюминия. Обсуждаются перспективы формирования планарных микроструктур с использованием пористого анодного оксида алюминия, поддерживающих электромагнитные моды шепчущей галереи