salicylates and titanium-dioxide

Fingermarks formed in or by blood often require specific development techniques. This review examines techniques and materials that may be used to enhance and record fingermarks deposited in blood or fingermarks generated by blood-contaminated papillary ridges. A large number of techniques are presented here and are discussed from a chemical as well as practical perspective. It is concluded that an optimized sequence of techniques targeting both latent (non-bloody) and bloody fingermarks must be applied to detect and enhance the maximum number of marks, and therefore optimize the information content from exhibits that may bear marks in blood.

Topics: Amine Oxidase (Copper-Containing); Benzenesulfonates; Benzidines; Benzothiazoles; Blood; Blood Stains; Coloring Agents; Dermatoglyphics; Forensic Sciences; Gentian Violet; Humans; Indicators and Reagents; Light; Luminescence; Methanol; Molecular Structure; Salicylates; Solvents; Sulfonic Acids; Titanium

Silicone elastomers have been widely used for rehabilitation of facial defects for more than 50 years. However, color change is the most common problem limiting the service life of facial prostheses. Whether the addition of ultraviolet protectives may enhance color stability of these materials is unclear.. The purpose of this in vitro study was to investigate the effect of ultraviolet protectives on the color stability of maxillofacial silicones after artificial aging.. Six color groups (unpigmented, white, yellow, red, blue, and mixed) of addition-type maxillofacial silicone were prepared. Four ultraviolet protectives benzophenone-3, ethylhexyl methoxycinnamate, titanium dioxide, and ethylhexyl salicylate at 0.5% and 1% concentrations by weight were incorporated into the silicone before polymerization. The specimens were artificially aged in an accelerated weathering chamber for 300 and 600 hours and in a thermocycling device. The color change values (E) of the maxillofacial silicones were evaluated. Data were statistically analyzed by using 4-way ANOVA. The differences were compared by the Tukey honestly significant difference test (α=.05).. Benzophenone-3 and ethylhexyl methoxycinnamate protectives did not reduce the ΔE values, and the 1% titanium dioxide groups exhibited lower ΔE values than the 0.5% titanium dioxide groups. Ethylhexyl salicylate protective generally reduced the ΔE values significantly in all color and aging groups when compared with the control groups (P<.05). In all control and ultraviolet protective groups, the highest ΔE values were seen with the red color in 300 and 600 hours of aging. Generally, no significant difference (P>.05) was seen in the ΔE values, which were clinically acceptable among the thermocycled color groups. After 600 hours of accelerated aging, the ΔE values were found to be higher than the values of 300-hour aging.. Ethylhexyl salicylate protective incorporated into maxillofacial silicones may improve color stability.

Topics: Color; Materials Testing; Maxillofacial Prosthesis; Prosthesis Coloring; Protective Agents; Salicylates; Silicone Elastomers

The combined effects of climate change and chemical contaminants on plant performance are still not well understood. Especially, whether different sexes of dioecious plants respond differently to combined stresses is unknown. In order to study the sex-related responses of European aspen to soil nTiO

Topics: Carbon Dioxide; Flavonoids; Hydroxybenzoates; Nanoparticles; Plant Leaves; Plant Roots; Plant Stems; Populus; Salicylates; Stress, Physiological; Temperature; Titanium

A novel TiO2-nanosheets coated fiber for solid-phase microextraction (SPME) was fabricated by anodization of Ti wire substrates in ethylene glycol with concentrated NH4F. The in situ fabricated TiO2-nanosheets were densely embedded into Ti substrates with about 1μm long, 300nm wide and 80nm thick. The as-fabricated TiO2-nanosheets coating was employed to extract polycyclic aromatic hydrocarbons, phthalates and ultraviolet (UV) filters in combination with high performance liquid chromatography-UV detection (HPLC-UV). It was found that the TiO2-nanosheets coating exhibited high extraction capability and good selectivity for some UV filters frequently used in cosmetic sunscreen formulations. The main parameters affecting extraction performance were investigated and optimized. Under the optimized conditions, the calibration graphs were linear in the range of 0.1-400μgL(-1). The limits of detection of the proposed method were between 0.026μgL(-1) and 0.089μgL(-1) (S/N=3). The single fiber repeatability varied from 4.50% to 8.76% and the fiber-to-fiber reproducibility ranged from 7.75% to 9.64% for the extraction of spiked water with 50μgL(-1) UV filters (n=5). The SPME-HPLC-UV method was successfully established for the selective preconcentration and sensitive detection of target UV filters from real environmental water samples. Recovery of UV filters spiked at 10μgL(-1) and 25μgL(-1) ranged from 88.8% to 107% and the relative standard deviations were less than 9.8%. Furthermore the in situ growth of the TiO2-nanosheets coating was performed in a highly reproducible manner and the TiO2-nanosheets coated fiber has high mechanical strength, good stability and long service life.

Topics: Acrylic Resins; Adsorption; Chromatography, High Pressure Liquid; Cinnamates; Dimethylpolysiloxanes; Electrochemical Techniques; Nanostructures; para-Aminobenzoates; Phthalic Acids; Reproducibility of Results; Rivers; Salicylates; Solid Phase Microextraction; Surface Properties; Titanium; Water Pollutants, Chemical

The photocatalytic (PC) degradation kinetics of sulfosalicylic acid (SSA) at different pH using TiO2 microspheres were elucidated by modeling. The resultant model had special consideration of adsorption and pH. The adsorption isotherms showed that the LC/MS(2)-identified intermediates were weakly adsorbed on the TiO2 microspheres, thus their adsorption was neglected in the modeling. By contrast, the SSA was significantly adsorbed, thus its adsorption retained as an item in the model. Consequently, a non-first-order model was obtained. Through the modeling, it was elucidated that the reaction rate increased non-linearly with the SSA adsorption equilibrium constant. Meanwhile, it was elucidated that a pH increase favored the hydroxyl radical production to accelerate the SSA degradation, while impeded the SSA adsorption to slower it, hence a neutral pH caused the fastest SSA degradation.

Topics: Adsorption; Benzenesulfonates; Catalysis; Chromatography, Liquid; Environmental Pollution; Hydrogen-Ion Concentration; Kinetics; Mass Spectrometry; Microspheres; Photochemical Processes; Salicylates; Titanium

Given that flavonoids are known for their ultraviolet (UV)B photoprotective properties in plants that contain them, we chose to study quercetin (1) and rutin (2) as agents that could potentially be used in sunscreen products. These two substances proved to behave in similar ways. When incorporated in oil-in-water emulsions, at a concentration of 10% (w/w), 1 and 2 give sun protection factor (SPF) values similar to that of homosalate, a standard substance. These two flavonoids also provided a non-negligible level of photoprotection in the UVA range. When used in association with titanium dioxide, the SPF obtained was around 30.

Topics: Algorithms; Molecular Structure; Quercetin; Rutin; Salicylates; Sunscreening Agents; Titanium; Ultraviolet Rays

The generation of hydroxyl (OH) radicals was investigated during ultrasonic irradiation and in the presence of TiO(2). The effect of TiO(2) on an ultrasonic system's oxidation power was evaluated by examining the oxidation of salicylic acid. The generation of the salicylic acid derivatives, 2,3-dihydroxybenzoic acid (DHBA) and 2,5-DHBA, was measured by high-performance liquid chromatography coupled with electrochemical detection under different experimental conditions. The presence of TiO(2) enhanced the generation of DHBA during ultrasonic irradiation, thus indicating a higher oxidation power in the ultrasonic system. Al(2)O(3) also increased the generation of DHBA during irradiation; however, the effect of TiO(2) was found to be higher than that of Al(2)O(3). The addition of OH radical scavengers such as dimethylsulfoxide (DMSO), methanol and mannitol significantly suppressed the production of DHBA, and DMSO was found to have the highest suppressive effect among all scavengers. The effects of dissolved gases on the generation of OH radicals were further studied, and their power was found to be in the order Xe > Ar > O(2) > N(2). The degassing of the irradiation solution completely suppressed the generation of OH radicals. These results indicate that the presence of TiO(2) accelerates the generation of OH radicals during ultrasonic irradiation, and that the process may be mediated through the induction of cavitation bubbles in irradiating solutions.

Topics: Aluminum Oxide; Catechols; Chromatography, High Pressure Liquid; Electrochemistry; Electron Spin Resonance Spectroscopy; Free Radical Scavengers; Gases; Hydroxybenzoates; Hydroxyl Radical; Salicylates; Spin Trapping; Titanium; Ultrasonics; X-Ray Diffraction

Nanometer size titanium dioxide modified with 3,5-dinitrosalicylic acid (3,5-DA) was prepared using chemical adsorption method. The influences of surface modification on the adsorption of p-nitrophenol (PNP) and the dispersion in solvent such as water, benzene and ethanol were studied. The 3,5-dinitrosalicylic acid is bonded to the surface hydroxyl from TiO2 nanoparticles, results in the formation of a stable, six-ring complex which color is buff. The 3, 5-DA-modified TiO2 nanoparticles have good dispersive capacity in water, benzene and ethanol. Under the optimum conditions such as pH value 3, adsorption time 10 min, the adsorption ratio of PNP by TiO2 is improved from 43% to 99.9% through surface modification. A new method could be used to remove directly 3 approximately 10mg/L PNP, and the residual concentrations is below the integrated wastewater discharge standard (GB 8978-1996).

Topics: Adsorption; Metal Nanoparticles; Nitrophenols; Salicylates; Titanium; Waste Disposal, Fluid

The surface of nanometer size TiO(2) was simply and fast modified by chemical adsorption in saturated solution of 5-sulfosalicylic acid. After surface modification, a stable, yellow surface complex was formed quickly, the wavelength response range of TiO(2) was expanded, it has obvious absorption in the region from 320 to 450 nm; the adsorption efficiency of p-nitrophenol (PNP) by TiO(2) was enhanced from 42% to 84%. The photocatalytic activity was tested on the degradation of PNP. The influences of catalyst and its dosage, pH value, and PNP concentration on the degradation were investigated. On optimal photodegradation conditions, including initial pH 4.0, PNP 5 mg l(-1), catalyst 100 mg, irradiation time 120 min with 160 W high-pressure mercury lamp, the degradation efficiency of PNP was increased from 40% to 88% after surface modification. Surface modification led not only to an increase in the light utilization, but also improved the surface coverage of PNP in comparison with the pure TiO(2). Both of these factors are crucial for the photocatalytic activity of heterogeneous photocatalysis, especially for photodegradation of benzenoid pollutants.

Topics: Adsorption; Benzenesulfonates; Benzoic Acid; Catalysis; Nitrophenols; Particle Size; Photochemistry; Salicylates; Surface Properties; Titanium; Ultraviolet Rays; Water Pollutants, Chemical; Water Purification

In this study, conventional TiO2 powder was heated in hydrogen (H2) gas at a high temperature as pretreatment. The photoactivity of the treated TiO2 samples was evaluated in the photodegradation of sulfosalicylic acid (SSA) in aqueous suspension. The experimental results demonstrated that the photodegradation rates of SSA were significantly enhanced by using the H2-treated TiO2 catalysts and an optimum temperature for the H2 treatment was found to be of 500-600 degrees C. The in situ electron paramagnetic resonance (EPR) signal intensity of oxygen vacancies (OV) and trivalent titanium (Ti3+) associated with the photocatalytic activity was studied. The results proved the presence of OV and Ti3+ in the lattice of the H2-treated TiO2 and indicated that both were contributed to the enhancement of photocatalytic activity. Moreover, the experimental results presented that the EPR signal intensity of OV and Ti3+ in the H2-treated TiO2 samples after 10 months storage was still significant higher than that in the untreated TiO2 catalyst. The experiment also demonstrated that the significant enhancement occurred in the photodegradation of phenol using the H2-treated TiO2.

Topics: Benzenesulfonates; Catalysis; Hot Temperature; Hydrogen; Models, Chemical; Oxidation-Reduction; Phenol; Photolysis; Salicylates; Titanium; Ultraviolet Rays; Waste Disposal, Fluid

The coordination chemistry of model phenolic ligands (pyrocatechol, salicylic acid, and 2,2'-biphenol) that are able to form respectively five-, six-, or seven-membered rings with titanium(IV) alkoxides is investigated. With pyrocatechol, a polynuclear complex containing 10 Ti atoms was characterized with a not very common doubly bridging mu3-(O,O,O',O') coordination mode. With salicylic acid, a monomeric tris(chelate) complex was obtained. With 2,2'-biphenol, a polynuclear complex containing six Ti atoms was obtained showing both mu2-(O,O') and mu2-(O,O,O') coordination modes for the ligands. Intermolecular interactions in the solid state for these three new compounds are also quantitatively discussed using the partial charge model.

Topics: Catechols; Crystallography, X-Ray; Models, Molecular; Molecular Conformation; Organometallic Compounds; Phenols; Salicylates; Titanium

The hydroxyl radical (.OH) is a highly reactive oxygen free radical that has been implicated as a cause of lung injury following exposure to silica and silicates. Despite evidence that silica generates .OH in vitro, there has been no previous demonstration of in vivo production of .OH after exposure to nonfibrous mineral oxide dusts. We tested the hypothesis that instillation of silica into rat lungs is associated with greater .OH production and acute lung inflammation in vivo relative to the instillation of a less toxic nonsilicate particle, titanium dioxide. The production of .OH in the lungs following dust instillation was measured using sodium salicylate as an .OH trap. Seven days after dust exposure, the rats were given intraperitoneal salicylate, the lungs isolated, and salicylate hydroxylation products (2,3- and 2,5-dihydroxybenzoic acid), reflecting .OH, were measured. There was significantly more 2,3-dihydroxybenzoic acid in silica-exposed lungs compared with lungs instilled with titanium dioxide. In addition, the instillation of silica into rat lungs in vivo was associated with a greater acute inflammatory response. We conclude that following in vivo exposure, silica stimulates greater .OH production relative to the less toxic particle, titanium dioxide. These differences in .OH generation correspond to disparities in acute lung inflammation.

Topics: Animals; Bronchoalveolar Lavage Fluid; Dust; Gentisates; Hydroxybenzoates; Hydroxyl Radical; Hydroxylation; Lung; Lung Injury; Organ Size; Pulmonary Fibrosis; Rats; Rats, Sprague-Dawley; Salicylates; Salicylic Acid; Silicon Dioxide; Silicosis; Titanium