Generally, skin properties are highly specific for each individual depending on various factors such as genetic predisposition, age, gender, body region, health and lifestyle. In this study, we measured various skin parameters on forehead, temple and cheek of 442 Caucasian women between 23 and 63 years, and evaluated differences between these facial regions and also the relationship between skin parameters and age of the volunteers. We measured transepidermal water loss (TEWL), stratum corneum hydration, skin gloss, melanin level, individual typology angle (ITA), erythema, sebum level and elasticity (R7). We observed significant negative relationship between age and TEWL, elasticity and skin lightness represented by ITA. Sebum, melanin and erythema levels increased up to the age of 50, when menopause usually takes place, and then decreased again. Evaluating the skin parameters on the forehead, temple and cheek area, we observed the biggest differences between the cheek and the forehead. The cheek possessed the worst skin parameters, such as the highest TEWL and erythema values and the lowest hydration.
In
this work, we report successful preparation of hierarchical
V-MCM-36 zeolitic catalyst. Vanadium was introduced onto the zeolite
support by impregnation, using vanadyl acetylacetonate as a metal
precursor and its subsequent solid state ion exchange during calcination.
A conventional three-dimensional V-MCM-22 zeolite was prepared by
the same way. Both zeolitic catalysts were characterized by nitrogen
adsorption isotherms, X-ray fluorescence, temperature-programmed reduction
by hydrogen (H2 -TPR), EPR, FT-IR, diffuse reflectance
UV–vis, and Raman spectroscopy. The effect of pillaring and
the presence of a combination of micro- and mesopores on catalytic
behavior were tested in the oxidative dehydrogenation of propane (C3–ODH) at 540 °C. Obtained results clearly showed
that activity of vanadium in zeolitic support is very similar to activity
of vanadium in mesoporous silica catalysts. It was also found that
hierarchical catalyst is slightly more selective toward propene and
exhibits more stable activity than three-dimensional V-MCM-22 catalyst
due to a lower rate of carbon deposit formation.
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