Non-dipping blood pressure in normotensive patients with Obstructive Sleep Apnea

To investigate circadian blood pressure profiles in normotensive patients with moderate te severe obstructive sleep apnea (OSA), in relatien te their apnea indices and left ventricular parameters, we studied twenty one male patients with clinic bleed pressures of 140/90 mmHg. They were matched for age and body mass index (BMI) and all were heavy snorers. They underwent overnight polysomnography, 24 h non-invasive arterial blood pressure monitoring (ABPM) and echocardiography. Patients with a nocturnal reductien in average daytime systolic and diastolic blood pressure of‘ less than 10% were considered non-dippers. Nine patients were non-clippers and 12 were clippers. In the non-dipper group asleep systolic and blood pressure were significantly higher than in the dipper group, (P< 0.0001 and P< 0.01  respectively), There were at significant differences between the apne of hypopnea (AHI) and the oxygen desaturatien (ODI) indices of the dipper and the non-dipper groups. However, left ventricular parameters were significantly higher in the non-dipper than in the dipper group: left ventricular mass index (LVMI, p< 0.001, posterier wall thickness (PWT, p< 0.00 1 ), interventricular septal thickness (IVST, P < 0.00 1 ) and relative wall thickness (RWT, P< 0.01). In this preliminary study an absent or reduced blood pressure fall during sleep in normotensive patients with moderate to severe 0SA cannot be explained by the severity of the apnea alone. Left  ventricular hypertrephy, though may be a sequel te the non-dipper situation may also be the cause of it.

Synthesis and photoluminescence properties of nanostructured mullite/α- Al2O3Al_2O_3

Phase transformation of α-Al2O3 to mullite was observed by correlated X-ray diffraction and low-temperature (7 K) time- and energy-resolved photoluminescence methods. The aluminosilicate solids with different Si:Al ratios were prepared after thermal treatment (1400 °C) of ultraporous alumina (UPA) monoliths impregnated with vapour of silica precursors at room temperature. The initial dispersion of Si is homogeneous on a size-scale of 5 nm raw UPA fibres, which grow in size during the thermal treatment stage up to ∼50–100 nm. Three phases were resolved in the considered SiO2/Al2O3 system: silica, α-Al2O3 and their interaction product 2:1 mullite (2Al2O3:SiO2). The 2:1 mullite mass increases and α-Al2O3 mass decreases with an increase of the initial silica content. At the SiO2 content in the initial system above 20 mol.%, the phase transformation to 2:1 mullite is complete and no α-Al2O3 was observed. No mullite phases with either lower or higher Si content were observed. The fundamental absorption onset energy 7.55 eV of 2:1 mullite was measured

Amorphous-anatase phase transition in single immobilised TiO2TiO_{2} nanoparticles

Kinetics of the amorphous–anatase phase transition in single immobilized 5-nm TiO2 nanoparticles has been studied at temperatures between 400 and 1000 °C at the DORIS-III synchrotron source of Hasylab. The measurements indicate the anatase phase appearance at temperatures above 500 °C. No formation of rutile phase was observed. The transformation kinetics for each fixed temperature is rapid and completes within 5 min. The crystalline mass progressively increases with temperature and the full transformation into anatase polymorph is achieved above 800 °C. The results suggest higher surface energy of the anatase phase compared to amorphous one, which delays the crystallization process

Synthesis and photoluminescence properties of nanostructured mullite/α-Al2O3

Phase transformation of α-Al2O3 to mullite was observed by correlated X-ray diffraction and low-temperature (7 K) time- and energy-resolved photoluminescence methods. The aluminosilicate solids with different Si:Al ratios were prepared after thermal treatment (1400 °C) of ultraporous alumina (UPA) monoliths impregnated with vapour of silica precursors at room temperature. The initial dispersion of Si is homogeneous on a size-scale of 5 nm raw UPA fibres, which grow in size during the thermal treatment stage up to ∼50–100 nm. Three phases were resolved in the considered SiO2/Al2O3 system: silica, α-Al2O3 and their interaction product 2:1 mullite (2Al2O3:SiO2). The 2:1 mullite mass increases and α-Al2O3 mass decreases with an increase of the initial silica content. At the SiO2 content in the initial system above 20 mol.%, the phase transformation to 2:1 mullite is complete and no α-Al2O3 was observed. No mullite phases with either lower or higher Si content were observed. The fundamental absorption onset energy 7.55 eV of 2:1 mullite was measured