Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailPhotoaging under recreational sunbeds.
QUATRESOOZ, Pascale ULg; HENRY, Frédérique ULg; PAQUET, Philippe ULg et al

in Skin Research & Technology (2011)

Background: Artificial sources of restricted light wavelength, particularly tanning beds, are progressively gaining importance in photoaging. Objective: To assess the kinetics and the long-term evolution ... [more ▼]

Background: Artificial sources of restricted light wavelength, particularly tanning beds, are progressively gaining importance in photoaging. Objective: To assess the kinetics and the long-term evolution of skin pigmentation and tensile functions in sunbed worshippers over a period of 8 years. Methods: Photoaging was explored in women who were both sunshine and sunbed worshippers. A series of 65 phototype III women aged 31-46 years completed a 100-month survey. Quarterly assessments were performed on the forearms to measure (a) the skin color individual typology angle (ITA degrees ), (b) the extent in mottled subclinical melanoderma (MSM) using the ultraviolet light-enhanced visualization method and (c) the rheological properties of skin. Results: A progressive increase in both skin extensibility and hysteresis was observed, contrasting with a decrease in biologic elasticity. These rheological changes were correlated with the ITA degrees changes, but not with the MSM extent. The kinetics of evolution of each test variable were distinct over time. Discussion: This work is the first attempt at evaluating the kinetics of changes in physical parameters during a long period of frequent exposures to tanning sunbeds and sunshine for lifestyle purposes. The alterations were quite important in the color, MSM and rheological functions of the skin. [less ▲]

Detailed reference viewed: 20 (5 ULg)
Full Text
Peer Reviewed
See detailPhotobiologie cellulaire.
Quatresooz, Pascale ULg; Pierard, Claudine ULg; Pierard, Gérald ULg

in Revue Médicale de Liège (2005), 60 Suppl 1

The various cell lines of the epidermis and dermis can be activated or conversely altered by actinic irradiations. Keratinocytes, melanocytes, Langerhans cells and connective tissue cells are the main ... [more ▼]

The various cell lines of the epidermis and dermis can be activated or conversely altered by actinic irradiations. Keratinocytes, melanocytes, Langerhans cells and connective tissue cells are the main targets. [less ▲]

Detailed reference viewed: 39 (1 ULg)
Full Text
Peer Reviewed
See detailPhotobiologie cutanée.
Hermanns-Le, Trinh ULg; Pierard, Claudine ULg; Pierard, Gérald ULg

in Revue Médicale de Liège (2005), 60 Suppl 1

The integration of the various cell reactions with ultraviolet light is modulated by the phototypes. It is responsible for photo-immunological processes and for photocancerogenesis.

Detailed reference viewed: 13 (5 ULg)
Full Text
Peer Reviewed
See detailPhotobiologie moléculaire.
Nikkels, Arjen ULg; Pierard, Claudine ULg; Pierard, Gérald ULg

in Revue Médicale de Liège (2005), 60 Suppl 1

Photochemical reactions are numerous in the skin. They generate reactive oxygen species and other biochemical alterations as well. According to their nature, the molecular components of the skin which ... [more ▼]

Photochemical reactions are numerous in the skin. They generate reactive oxygen species and other biochemical alterations as well. According to their nature, the molecular components of the skin which have been altered by these mechanisms can be repaired with various degrees of efficacy. [less ▲]

Detailed reference viewed: 48 (3 ULg)
Full Text
Peer Reviewed
See detailPhotocancérogenèse cutanée.
Uhoda, Isabelle; Quatresooz, Pascale ULg; Rorive, Andrée ULg et al

in Revue Médicale de Liège (2005), 60 Suppl 1

Most of the cutaneous carcinomas and melanomas are photo-induced cancers. By contrast, some cutaneous lymphomas are inhibited by light exposure. The annual incidence of photo-induced cancers is steadily ... [more ▼]

Most of the cutaneous carcinomas and melanomas are photo-induced cancers. By contrast, some cutaneous lymphomas are inhibited by light exposure. The annual incidence of photo-induced cancers is steadily on the rise. [less ▲]

Detailed reference viewed: 71 (2 ULg)
Full Text
Peer Reviewed
See detailPhotocatalytic degradation of phenol and benzoic acid using zinc oxide powders prepared by the sol-gel process
Benhebal, Hadj; Chaib, Messaoud; Salmon, Thierry ULg et al

in Alexandria Engineering Journal (2013), 52(3), 517-523

Photocatalytic degradation of phenol and benzoic acid in aqueous solution was studied using zinc oxide (ZnO) powder synthesized by sol–gel process. Synthesized catalyst was characterized by X-ray ... [more ▼]

Photocatalytic degradation of phenol and benzoic acid in aqueous solution was studied using zinc oxide (ZnO) powder synthesized by sol–gel process. Synthesized catalyst was characterized by X-ray diffraction and transmission electron microscopy. The Brunauer–Emmett–Teller surface area, pHpzc, and the band gap of the catalyst samples were also measured. The influence of various key parameters such as amount of photocatalyst, initial solution pH, and the initial concentration of phenol and benzoic acid was investigated. [less ▲]

Detailed reference viewed: 42 (5 ULg)
Full Text
Peer Reviewed
See detailPhotocatalytic degradation of water pollutants with visible light-sensitized TiO2 xerogels
Tasseroul, Ludivine ULg; Pirard, Sophie ULg; Lambert, Stéphanie ULg et al

in Récents Progrès en Génie des Procédés (2014), 106

To extend its photocatalytic activity to visible light, TiO2 has been doped in situ through the cogelation sol-gel proces with two dyes : free metal tetra(4-carboxyphenyl)porphyrin and nickel tetra(4 ... [more ▼]

To extend its photocatalytic activity to visible light, TiO2 has been doped in situ through the cogelation sol-gel proces with two dyes : free metal tetra(4-carboxyphenyl)porphyrin and nickel tetra(4-carboxyphenyl)porphyrin. DR and FT-IR spectroscopies have been performed to determine the interaction between porphyrins and TiO2. Cristallinity and specific surface area have been measured by XRD and N2 adsorption. The photoactivity of the doped TiO2 xerogels has been evaluated for p-nitrophenol (a model water pollutant) degradation under visible light and a kinetic study has been performed. The samples allow the degradation of 40% of p-nitrophenol in 6 h which makes them very promising for water decontamination under natural light. A kinetic study of p-nitrophenol degradation with the Ni-doped catalyst has shown that the best kinetic model involves one type of active site corresponding to the hole h+ of electron-hole pairs created at the TiO2 surface by light. The rate determining step consists of the surface reaction between adsorbed p-nitrophenol and adsorbed OH• radicals. [less ▲]

Detailed reference viewed: 25 (6 ULg)
Peer Reviewed
See detailPhotocatalytic TiO2 Macroscopic Fibers Obtained Through Integrative Chemistry
Kinadjian, Natacha ULg; Le Bechec, Mickael; Pigot, Thierry et al

Poster (2012, November 25)

The photocatalytic properties of titanium dioxide depend not only on its electronic properties, but also on the material size and shape, which can increase interactions between the reactants and catalyst ... [more ▼]

The photocatalytic properties of titanium dioxide depend not only on its electronic properties, but also on the material size and shape, which can increase interactions between the reactants and catalyst. Most studies to date show that reducing the particle size down to the nanoscale increases photocatalytic efficiency, as a result of a higher surface to volume ratio and because a larger proportion of the material is actually irradiated by light. We demonstrate that a multiscale shape design, which integrates surface roughness, particle shape, and 1D material processing and orientation, can favor photocatalytic properties in the solidgas regime, especially mineralization (conversion into CO2), when the hierarchical 1D orientation of the material is combined with unidirectional gas flow. Several materials with hierarchical structure were prepared and characterized. They have been tested for the photocatalytic mineralization of gaseous acetone and compared with commercial catalysts. Our study reveals that a suitable combination of multiscale design and optimization of the material orientation and gas flow favors high mineralization. [less ▲]

Detailed reference viewed: 5 (3 ULg)
Peer Reviewed
See detailPhotocatalytic TiO2 Macroscopic Fibers Obtained Through Integrative Chemistry
Kinadjian, Natacha ULg; Le Bechec, Mickael; Pigot, Thierry et al

Poster (2013, March)

The photocatalytic properties of titanium dioxide depend not only on its electronic properties, but also on the material size and shape, which can increase interactions between the reactants and catalyst ... [more ▼]

The photocatalytic properties of titanium dioxide depend not only on its electronic properties, but also on the material size and shape, which can increase interactions between the reactants and catalyst. Most studies to date show that reducing the particle size down to the nanoscale increases photocatalytic efficiency, as a result of a higher surface to volume ratio and because a larger proportion of the material is actually irradiated by light. We demonstrate that a multiscale shape design, which integrates surface roughness, particle shape, and 1D material processing and orientation, can favor photocatalytic properties in the solidgas regime, especially mineralization (conversion into CO2), when the hierarchical 1D orientation of the material is combined with unidirectional gas flow. Several materials with hierarchical structure were prepared and characterized. They have been tested for the photocatalytic mineralization of gaseous acetone and compared with commercial catalysts. Our study reveals that a suitable combination of multiscale design and optimization of the material orientation and gas flow favors high mineralization. [less ▲]

Detailed reference viewed: 6 (2 ULg)
Full Text
Peer Reviewed
See detailPhotocatalytic TiO2 Macroscopic Fibers Obtained Through Integrative Chemistry
Kinadjian, Natacha ULg; Le Bechec, Mickael; Pigot, Thierry et al

in European Journal of Inorganic Chemistry [=EurJIC] (2012)

The photocatalytic properties of titanium dioxide depend not only on its electronic properties, but also on the material size and shape, which can increase interactions between the reactants and catalyst ... [more ▼]

The photocatalytic properties of titanium dioxide depend not only on its electronic properties, but also on the material size and shape, which can increase interactions between the reactants and catalyst. Most studies to date show that reducing the particle size down to the nanoscale increases photocatalytic efficiency, as a result of a higher surface to volume ratio and because a larger proportion of the material is actually irradiated by light. We demonstrate that a multiscale shape design, which integrates surface roughness, particle shape, and 1D material processing and orientation, can favor photocatalytic properties in the solidgas regime, especially mineralization (conversion into CO2), when the hierarchical 1D orientation of the material is combined with unidirectional gas flow. Several materials with hierarchical structure were prepared and characterized. They have been tested for the photocatalytic mineralization of gaseous acetone and compared with commercial catalysts. Our study reveals that a suitable combination of multiscale design and optimization of the material orientation and gas flow favors high mineralization. [less ▲]

Detailed reference viewed: 7 (2 ULg)
Full Text
Peer Reviewed
See detailPhotochemical properties and activity of water-soluble polymer/C60 nanohybrids for photodynamic therapy
Hurtgen, Marie ULg; Debuigne, Antoine ULg; Hoebeke, Maryse ULg et al

in Macromolecular Bioscience (2013), 13(1), 106-115

Water-soluble star-like poly(vinyl alcohol)/C60 and poly{[poly(ethylene glycol) acrylate]-co- (vinyl acetate)}/C60 nanohybrids are prepared by grafting macroradicals onto C60 and are assessed as ... [more ▼]

Water-soluble star-like poly(vinyl alcohol)/C60 and poly{[poly(ethylene glycol) acrylate]-co- (vinyl acetate)}/C60 nanohybrids are prepared by grafting macroradicals onto C60 and are assessed as photosensitizers for photodynamic therapy. The photophysical and biological properties of both nanohybrids highlight key characteristics influencing their overall efficiency. The macromolecular structure (linear/graft) and nature (presence/absence of hydroxyl groups) of the polymeric arms respectively impact the photodynamic activity and the stealthiness of the nanohybrids. The advantages of both nanohybrids are encountered in a third one, poly[(Nvinylpyrrolidone)- co-(vinyl acetate)]/C60, which has linear grafts without hydroxyl groups, and shows a better photodynamic activity. [less ▲]

Detailed reference viewed: 25 (5 ULg)
Peer Reviewed
See detailPhotochemical reactions of Rose Bengal as a probe of bile salts aggregation process
Seret, Alain ULg; Van de Vorst, Albert

Poster (1992, July)

Detailed reference viewed: 31 (0 ULg)
Full Text
Peer Reviewed
See detailPhotochemistry of 2,6-diisopropylphenol (propofol)
Heyne, B.; Tfibel, F.; Hoebeke, Maryse ULg et al

in Photochemical & Photobiological Sciences (2006), 5(11), 1059-1067

The photochemistry of the anaesthetic agent propofol (PPF) was investigated in three different solvents of quite different polarity (cyclohexane, methanol and phosphate buffer pH 7) by means of nanosecond ... [more ▼]

The photochemistry of the anaesthetic agent propofol (PPF) was investigated in three different solvents of quite different polarity (cyclohexane, methanol and phosphate buffer pH 7) by means of nanosecond laser flash photolysis and absorption spectroscopy. GC-MS spectrometry measurements of PPF in cyclohexane have revealed the formation of two major products upon low intensity UV continuous irradiation of PPF in aerated solution: the diphenol derivative of PPF and 2,6-diisopropyl-p-benzoquinone (PPFQ). Only the diphenol compound was obtained in anaerobic solution. PPF phenoxyl radical (PPF ) generation has been assigned as the original step leading to the formation of both the diphenol compound and PPFQ in cyclohexane as revealed by laser flash photolysis at 266 nm and by electron paramagnetic resonance spectroscopy as well. Investigation of PPF by nanosecond flash photolysis at 266 nm in the other solvents revealed the occurrence of different photochemical processes depending on the nature and the polarity of the solvent. A reaction scheme is proposed in order to discuss the mechanism of reaction of PPF in all media. [less ▲]

Detailed reference viewed: 23 (5 ULg)
Peer Reviewed
See detailThe photochemistry of the semi-oxidized form of Eosin Y and Rose Bengal in aqueous sodium dodecyl sulphate solutions
Seret, Alain ULg; Van de Vorst, Albert

in Journal of Photochemistry and Photobiology A : Chemistry (1988), 43(2), 193-206

In aerobic aqueous solutions, the semi-oxidized form of the halofluorescein dyes disappears via a bimolecular reaction with itself and via the formation of an adduct with OH− ions. In aerobic aqueous ... [more ▼]

In aerobic aqueous solutions, the semi-oxidized form of the halofluorescein dyes disappears via a bimolecular reaction with itself and via the formation of an adduct with OH− ions. In aerobic aqueous solutions of sodium dodecylsulphate, semi-oxidized rose bengal is solubilized in the micelles, and its exit rate from the micellar aggregates is lower than 60 s−1. The properties of semi-oxidized eosin Y in sodium dodecylsulphate solutions are interpreted in terms of a model based on an adsorption equilibrium between water-bound and micelle-bound dye radicals. This equilibrium depends on the surfactant concentration between the critical micelle concentration and 80 mmol dm−3. Over this range, the reactivity of the semi-oxidized form with itself and towards hydrophilic quenchers decreases when the surfactant concentration is increased. The reaction of the semi-oxidized form with itself is involved in the bleaching of these dyes and the photoproduct is clearly able to react with the semi-oxidized radical of the xanthene dyes. [less ▲]

Detailed reference viewed: 19 (0 ULg)
Full Text
Peer Reviewed
See detailPhotoclick chemistry: Applications to 18F radiotracers preparation
Thonon, David ULg; Goukens, Eve ULg; Kaisin, Geoffroy ULg et al

in Journal of Labelled Compounds and Radiopharmaceuticals (2011)

Detailed reference viewed: 61 (21 ULg)
Peer Reviewed
See detailPhotodegradation of bacteria on TiO2 thin films produced by sol-gel method
Tasseroul, Ludivine ULg; Braconnier, Benoît; Nonet, Stéphane et al

Conference (2008)

Detailed reference viewed: 12 (3 ULg)
See detailPhotodegradation of bacteria with TiO2 produced by sol-gel method
Tasseroul, Ludivine ULg; Pàez Martinez, Carlos ULg; Braconnier, Benoît et al

Poster (2007)

Detailed reference viewed: 8 (3 ULg)
Full Text
Peer Reviewed
See detailPhotodegradation of phenol and benzoic acid by sol-gel-synthesized alkali metal-doped ZnO
Benhebal, H.; Chaib, M.; Léonard, Angélique ULg et al

in Materials Science in Semiconductor Processing (2012), 15(3), 264269

Detailed reference viewed: 41 (7 ULg)