Investigation of the chemical and radiation stability of titanium dioxide with surface arsenate groups during Sr adsorption.

The chemical and radiation stability of titanium dioxide with surface arsenate groups during Sr adsorption has been studied. The oxalate technique has been used to obtain a solution containing Sr from the objects of the aquatic environment of the Chornobyl Exclusion Zone. The dependence of the strontium adsorption on the acidity of the solution and the initial activity of the solution (Bq per mL) has been shown.

Equilibrium studies of yttrium adsorption from aqueous solutions by titanium dioxide.

This research evaluates the adsorption of yttrium from aqueous solutions by titanium dioxide with surface arsenate groups (4As-TiO) and titanium dioxide with surface arsenate groups doped by neodymium (Nd/4As-TiO). The impacts of various adsorption parameters such as contact time, pH and initial metal concentrations were investigated in batch adsorption experiments. Experimental data for yttrium ions adsorption onto Nd/4As-TiO fits well with the Elovich kinetic model (R = 0.

Structure and the catalysis mechanism of oxidative chlorination in nanostructural layers of a surface of alumina.

On the basis of X-ray diffraction and mass spectrometric analysis of carrier γ-Al2O3 and catalysts CuCl2/CuCl on its surface, the chemical structure of the active centers of two types oxidative chlorination catalysts applied and permeated type of industrial brands "Harshow" and "MEDС-B" was investigated. On the basis of quantum-mechanical theory of the crystal, field complexes were detected by the presence of CuCl2 cation stoichiometry and structure of the proposed model crystal quasichemical industrial catalyst permeated type MEDС-B for oxidative chlorination of ethylene. On the basis of quantum-mechanical calculations, we propose a new mechanism of catalysis crystal quasichemical oxidative chlorination of ethylene reaction for the catalysts of this type (MEDС-B) and confirmed the possibility of such a mechanism after the analysis of mass spectrometric studies of the active phase (H2 [CuCl4]) catalyst oxidative chlorination of ethylene.

Use of heated humidification during nasal CPAP titration in obstructive sleep apnoea syndrome.

Nasal symptoms associated with the use of nasal continuous positive airway pressure (nCPAP) in obstructive sleep apnoea (OSA) can adversely impact on patients' tolerance, acceptance and adherence to nCPAP therapy. Regular use of heated humidification is effective in alleviating these symptoms and improve patient comfort. In a randomised, parallel, double-blinded, controlled study, the present authors examined the use of heated humidification during a single night laboratory nCPAP titration in untreated OSA patients and its effect on nasal symptoms, nasal airway resistance (NAR), effective pressure and treatment tolerability and acceptance.

A randomized controlled trial of continuous positive airway pressure in mild obstructive sleep apnea.

A common clinical dilemma faced by sleep physicians is in deciding the level of severity at which patients with obstructive sleep apnea (OSA) should be treated. There is particular uncertainty about the need for, and the effectiveness of, treatment in mild cases. To help define the role of nasal continuous positive airway pressure (CPAP) treatment in mild OSA we undertook a randomized controlled cross-over trial of CPAP in patients with an apnea- hypopnea index (AHI) of 5 - 30 (mean, 12.

Portable computerized polysomnography in attended and unattended settings.

Study Objective: We compared the validity of a new portable polysomnographic recorder against a laboratory-based polysomnographic system from the same manufacturer.

Design And Patients: Simultaneous, full polysomnographic recordings from the portable device (PSGP) and the laboratory-based system (PSGL) were obtained using separate sets of sensors on 20 patients referred for investigation of sleep apnea.

Setting: After initial optimization of signals, the portable device was left unattended in 10 of the patients (to simulate home studies), while in the other 10 the signals were reviewed on a laptop computer screen and adjustments to electrode or sensor placement made as needed during the studies.

Sleep apnoea related hypoxia is associated with cognitive disturbances in patients with tetraplegia.

Sleep disordered breathing is common in patients with tetraplegia. Nocturnal arterial hypoxemia and sleep fragmentation due to sleep apnoea may be associated with cognitive dysfunction. We therefore studied the influence of sleep disordered breathing on neuropsychological function in 37 representative tetraplegic patients (mean age 34 +/- 9.

Sleep apnoea in patients with quadriplegia.

Background: This study was undertaken to establish the prevalence of, and the factors contributing towards, sleep disordered breathing in patients with quadriplegia.

Methods: Forty representative quadriplegic patients (time since injury > 6 months, injury level C8 and above, Frankel category A, B, or C; mean (SE) age 35.0 (1.