Simple preparation of broadband UV filters based on TiO2 coated with aqueous extracts of native trees from the Chaco region of Argentina.

The native forest of northwestern Argentina, as part of the Chaco region, is a rich and unexploited source of phytochemical compounds for medicinal/cosmetic applications. In the present study, fruit, leaf, branch, and bark organs of the native trees Sarcomphalus mistol (Mistol, M) and Schinopsis lorentzii (Quebracho Colorado santiagueño, QC) were harvested, and aqueous plant extracts (PE) were prepared. The spectroscopic (UV-Vis absorbance, diffuse reflectance, ATR-FTIR) and antioxidant (TEAC, Folin-Ciocalteu) properties of PE were characterized and used as TiO2 coating material to obtain a series of TiO2@PE nanocomposites. These materials showed almost null photocatalytic activity compared to aqueous suspensions of bare TiO2, displaying yellowish to brownish coloration and high long-term stability in both freshwater and seawater model solutions. The loss of photocatalytic activity in TiO2@PE was associated with the combination of the internal filter effect and the antioxidant/radical capacity exerted by the phytochemicals of the PE coating, with higher broadband photoprotection for the nanocomposites prepared with QC extracts. Thus, this study shows the potential capacity of the forest resources of the Chaco region of Argentina for the development of new cosmetic and/or sun protection formulations.

Determination of the Anthropometric Measures of the Lips by Age Groups in the Mestiza Population.

Measurements from a certain population may show a similar pattern that allows an alteration to be easily recognized and enable a better surgical approach. In our population, the changes in the anthropometric measurements of the lips are unknown, so our objective is to determine the variations in these measurements by decades of age to achieve a better aesthetic and reconstructive surgical approach. Anthropometric measurements of the lips were taken with a vernier in relation to the previously marked anatomical points. The sample consists of 174 patients who came for care not related to labial pathologies with ages between 20 and 80 years with Mexican nationality. We use the sample calculation formula to estimate an average, with an alpha error of 0.5 and a tolerance of 2 mm of the data for the measurements of the height of the lower face with an average measurement of 56.2 mm and a SD of 8.87 mm of the Marzena's article. Wyganowska-Swiatkowska and colleagues Average measurements were obtained, where a progressive longitudinal increase in measures: al-ch, sbl-cph, sn-Is, li-sto, cph-Is, li-sl, ch-li, li-pg according to aging is confirmed. In contrast, the ch-cph and ch-sbl measures, remain the same despite the aging, showing greater changes in the sagittal plane than in the parasagittal. The study only shows measures of length, so caring out a magnetic resonance imaging study to also measure the volume and perform it with a larger sample to have the optimal standard is further needed.

Photocatalytic Efficiency Tuning by the Surface Roughness of TiO2 Coatings on Glass Prepared by the Doctor Blade Method.

A set of opaque films were prepared with Degussa P25® or Hombikat UV100® TiO2 powders by the doctor blade method on glass slides with different compositions of polyethylene glycol of 20 kDa (PEG20), and they were characterized by spectroscopy, microscopy and photochemical kinetics measurements. After annealing treatment at 450 °C, about 5-7% C atom was incorporated into the films, as a consequence of the degradation of the organic complexing agents, inducing a small reduction of the energy band gap of TiO2 (i.e. 3.02 ≤ Eg (eV) ≤ 3.08). All films were about 15 ± 2 µm thick but their micro-morphological characteristics depended on the content of PEG20, showing different patterns of cracks and aggregates that produce intense light scattering and retransmission phenomena with the result of a three-dimensional excitation of the TiO2 particles in the thick film. Back-face excitation with UVA light (365 ± 42 nm) of the opaque films in contact with an aqueous solution produced both surface-bound and free hydroxyl radicals (HO• ), as detected using a coumarin solution as a radical dosimeter. The photogeneration efficiency of HO• decreased with the surface roughness of the films, which varied between 135 and 439 nm depending on the film's composition.