New functional material: spark plasma sintered Si/SiO2 nanoparticles - fabrication and properties.

A bulk nanostructured material based on oxidized silicon nanopowder was fabricated using a spark plasma sintering technique. Structural investigations revealed that this material has the composition of ∼14 nm core Si granules inside an SiO2 shell. Photoluminescence measurements have shown that the emission spectra lie in the energy range of 0.6-1.1 eV, which is not typical of the emissions of the Si/SiO2 nanostructures reported in numerous papers. This result can be explained by the formation of energy states in the bandgap and the participation of these states in both electronic transport and photoluminescence emission. Annealing of the sample leads to a decrease in defect density, which in turn leads to quenching of the 0.6-1.1 eV photoluminescence. In this case ∼1.13 eV inter-band transitions in the Si core start to play a dominant role in radiative recombination. Thus, the possibility of controlling the photoluminescence emission over a broad wavelength range was demonstrated.

[The use of transcutaneous electric neurostimulation for postoperative analgesia in parturients undergoing cesarean section]. / Ispol'zovanie chreskozhnoi élektroneirostimuliatsii dlia posleoperatsionnoi analgezii u rodil'nits, perenesshikh kesarovo sechenie.

The study has been performed in 210 women with cesarean section: in 160 patients analgesia was performed with transcutaneous electrical neurostimulation and in 50 patients narcotic analgesics were used. It has been established that both techniques ensure adequate analgetic effect. At the same time transcutaneous electrical neurostimulation, ensuring good to excellent analgesia in 77.5% of women, has no negative effect on hemodynamics and respiratory function and accelerates rehabilitation processes.

[Central hemodynamics in women during labor with combined use of prostaglandin E2 and prolonged epidural analgesia]. / Tsentral'naia gemodinamika u rozhenits pri sochetannom primenenii prostaglandina E2 i dlitel'noi épidural'noi anal'gezii.

Changes in central hemodynamics have been studied in 60 women with weak labour efforts treated with prostenon and subject to prolonged epidural analgesia (PEA). It has been established that PEA has a pronounced antihypertensive effect, decreases the heart rate (HR), cardiac index (CI), reserve coefficient (RC) and integral tonic coefficient (ITC) and increases significantly stroke index (SI). Prostenon, having a modulating effect on the cardiovascular system, induces an increase in mean blood pressure (MBP) in hypotensive patients and a decrease in MBP in hypertensive patients, lowers SI and ITC and elevates HR, CI and RC. In combined application, prostenon compensates for a number of hemodynamic shifts caused by PEA. The method of labour stimulation described seems advisable in women with late toxemia of pregnancy, provided labour stimulation is started with prostenon administration.