Pore size distribution of micelle-templated silicas studied by thermoporosimetry using water and n-heptane

Thermoporosimetry, i.e., DSC measurements of melting point depression of water and heptane confined in mesopores, has been used for determination the pore size distribution of several mesoporous silicas synthesized with the use of micelle templates. Porosity of these materials was additionally characterized by low-temperature nitro- gen adsorption and quasi-equilibrated thermodesorption of nonane. The pore size distributions obtained using the water thermoporosimetry were similar to those determined using the other methods, but the pore size values found for the narrow pore materials were underestimated by ca 1 nm. Too large pore sizes obtained for the wide pore silica from heptane thermoporosimetry were attributed to nonlinear dependence of the melting point depression on the reci- procal of the pore size

Studies of phase diagram and glass transitions of a liquid crystal with ferro- and antiferroelectric phasesl

Based on the results of the differential scanning calorimetry, of transmitted light intensity measurements and of texture observations the phase diagram of 4-(6-hepta-fluoro-butano-iloxy-hexy-loxy)bi-phenyl-4'-carbo-xy-late(S)-4-(methylo-hepty-loxy-1-carbonyl)-phenyl (4H6) was obtained. The following phases were identified on cooling: isotropic, smectic A, smectic C*, smectic C*A phases and a highly ordered phase called SmX and its glass. During heating transformation from glass of SmX to SmX phase and then transition to a metastable Cr2 phase, evolving to the more stable Cr1 phase, were observed. On further heating SmC*A, SmC* and Sm phases were identified. When Cr2 was cooled, a glass transition was also observed

Effect of cobalt doping on the dielectric response of B0.95Pb0.05TiO3B_{0.95}Pb_{0.05}TiO_3 ceramics

Dielectric response of Ba 0.95 Pb 0.05 TiO 3 ceramics doped with 0.1 and 1 wt.% of Co 2 O 3 , synthesized by conven- tional high-temperature method, wa s studied in wide temperature and frequency range. The temperature dependences of the real and the imaginary parts of dielectric permittivity of the ceramics were compared with those of BaTiO 3 and Ba 0.95 Pb 0.05 TiO 3. The addition of Co 3+ ions results in a broadening of dielectric anom- alies related to the transition to p araelectric cubic phase, and the structural transition between the tetragonal and the orthorhombic phases. At low temperatures (125 – 200 K) the dielectric absorp- tion of Co-doped Ba 0.95 Pb 0.05 TiO 3 ceramics was found to exhibit relaxor-like properties. The die lectric response has been found to contain the contributions characte ristic of fluctuations of the polar nanoregion boundaries and reorientations of the dipole moments between allowed directions in the nanoregions in the rhombohe- dral and the orthorhombic phases. The behavior speaks in favor of ordering of polar defects in the host lattice of Ba 0.95 Pb 0.05 TiO 3 in a form polar nanoregions

Health behaviours of the students of Taiwan origin studying in Poland

Cultural diversity become to be more and more common phenomenon at Poland. Because of the migration of the society, nurses more often need to care about patients from other cultures, as from Taiwan. People from Taiwan care about health in a different way than Poles. Understanding of different point of view on provided care (which is influenced by the culture) and health behaviors is very useful skill for nurses. The goal of that work is better understanding of health behaviors in group of young people from Taiwan. The study was conducted with the use of a diagnostic questionnaire and such research tools as: a questionnaire concerning health behaviour designed by the authors and the Self-Efficacy Scale (Schwarzer, Jerusalem). The study was made on group of 60 people from Taiwan. 40 of them are students of Silesia Medical Academy at Katowice and rest of them are studying at Taiwan. Study shown that 39% of male Taiwanese, which study at Poland have overweight and 12% of female Taiwanese have underweight. Most frequently consumed products were fruits and vegetables. Males drink approximately 1 liter of alcohol per month and females half less. 11% of females and 21% of males smoke cigarettes. Most of female Taiwanese don't use contraception. Males use protection more often but also admits to casual sex. Most of them prefer to spend free time in both, active and passive way. Half of the respondents had a high level of self-efficacy. Subjects with low self-efficacy show a more frequent risk behaviors as smoking cigarettes and "casual sex". Taiwanese adhere to Polish principles of healthy life-style. Males demonstrates bad life-style behaviors more often than females. Change in alteration of health behaviors because of change of environment was not observed

Antioxidant-loaded mesoporous silica : an evaluation of the physicochemical properties

The dangerous effects of oxidative stress can be alleviated by antioxidants—substances with the ability to prevent damage caused by reactive oxygen species. The adsorption of antioxidants onto nanocarriers is a well-known method that might protect them against rough environ-mental conditions. The aim of this study was to investigate the adsorption and desorption of gallic acid (GA), protocatechuic acid (PCA), chlorogenic acid (CGA), and 4-hydroxybenzoic acid (4-HBA) using commercially available mesoporous silica materials (MSMs), both parent (i.e., SBA-15 and MCM-41) and surface functionalized (i.e., SBA-NH2 and SBA-SH). The MSMs loaded with active compounds were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), thermoporometry (TPM), and powder X-ray diffraction (XRD). High-performance liquid chromatography (HPLC-CAD) was used to evaluate the performance of the adsorption and desorption processes. The antioxidant potential was investigated using the Folin–Ciocalteu (FC) spectrophotometric method. Among the studied MSMs, the highest adsorption of GA was observed for amine-modified SBA-15 mesoporous silica. The adsorption capacity of SBA-NH2 increased in the order of PCA, 4-HBA < GA < CGA. Different desorption effectiveness levels of the adsorbed compounds were observed with the antioxidant capacity preserved for all investigated compounds

Studies of phase diagram of a liquid crystal with 4-[2-(3-fluorophenyl)ethyl]biphenyl core of molecules

Basing on the results of di erential scanning calorimetry and transmitted light intensity methods and texture observations in the temperature range from −50 ◦C to 90 ◦C phase diagram of 1-[3- uoro-4-(1-methylheptyloxycarbonyl)phenyl]-2-[4′ -(2,2,3,3,4,4,4-hepta uorobutoxybutoxy)biphenyl-4-yl]ethane was established. Monotropic system of thermodynamic phases was found. On cooling the isotropic phase transforms at 85 ◦C to ferroelectric SmC∗ phase and further two liquid crystalline phases, antiferroelectric SmC∗ A and SmI, and a metastable crystal Cr2 reveal. During heating exothermic anomaly in the wide temperature range was observed and ascribed to evolution of Cr2 to the stable crystal Cr1. On further heating both SmC∗ A and SmC∗ phases were observed. Thermodynamic parameters were calculated for all phase transitions. During rapid cooling (10 K/min) vitri cation of metastable Cr2 crystal at T_g = −115 ◦C was registered

Data regarding particle size distribution, thermal properties and gaseous phase hydration of co-milled solid dispersions composed of tadalafil and Soluplus

A mechanical activation of the solid particles upon high-energy ball milling may considerably change the physicochemical properties of pharmaceutical compounds, including the morphology, particle size distribution, thermal properties, and surface interactions with water vapour upon gaseous phase hydration. Assessment of these changes is crucial for optimizing the manufacturing process of enabling drug products. In this article, we provide a detailed characterization of binary co-milled solid dispersions composed of tadalafil and Soluplus using a laser diffraction method, differential scanning calorimetry (DSC), gravimetric measurements and solid state (1)H- NMR spectroscopy. The data presented in this article is directly related to our previously published research article. They complement information on the impact that both formulation and process variables may have on the properties of these binary powder formulations