The ovarian hyperstimulation syndrome in extracorporeal oocyte fertilization and the transfer of cleavage-stage embryos

Major clinical characteristics of ovarian hyperstimulation syndrome are described and criteria of predicting the course of this disease and measures to prevent it presented. Statistical data on the presence of this syndrome in various forms during various schemes of superovulation stimulation are offered. Optimal schemes for the treatment of the condition are suggested.     

Increasing the linear density uniformity of yarn spun from an aggressive solution

Conclusions It has been found experimentally that to increase the uniformity of linear density of yarn spun from an aggressive spinning solution of 40–50 Pa·sec viscosity, it is necessary to use metering pumps of high output and to maintain a positive pressure difference of up to 1 MPa between the spinning solution pressure at intake and that at discharge from the pump.A new candle filter construction has been proposed for maintaining a positive difference between the spinning solution pressure at intake and at discharge.Translated from Khimicheskie Volokna, No. 1, pp. 40–41, January–February, 1986.     

Using biochemically purified water at coke plants

The use of biochemically purified water in place of industrial-grade water for the exhaust-gas scrubbers in the drying department of the coal-enrichment shop and for irrigation of the cyclone washers in the coke shops at OAO ZSMK is considered. It is found that biochemically purified water may be used for 100% of the water needs in coke production. Using biochemically purified water in the dust-trapping equipment, the coaland coke-dust content of the atmospheric emissions may be reduced by 24.5%. Additional purification of wastewater by adsorption on coke and coal dust is possible.     

Ceramics and Thick Films Based on Bi2 – x(Pb, Sb)xSr2Ca2Cu3Oy Compounds as High-Tc Superconductors and Electrode Materials

Complex cuprates of the compositions Bi_1.6Pb_0.4Sr_1.8Ca₂Cu₃O _y and Bi_1.7Pb_0.2Sb_0.1Sr₂Ca₂Cu₃O _y are synthesized. The electrical properties of the superconductors prepared are investigated. Thin films based on the bismuth cuprates studied are produced. It is demonstrated that the thin films prepared can be used as electrodes being in contact with a solid electrolyte for designing oxygen partial pressure gauges.     

Synthesis and comparative studies of xerogels,aerogels, and powders based on the ZrO<Subscript>2</Subscript>–Y<Subscript>2</Subscript>O<Subscript>3</Subscript>–СeO<Subscript>2</Subscript> system

The technology of liquid-phase synthesis of mesoporous xerogels and aerogels based on ZrO₂–Y₂O₃–CeO₂ is developed. Xerogels are obtained by the coprecipitation of hydroxides, while aerogels are obtained in accordance with the sol–gel technology: the average pore size is 1.5–17.2 nm and the specific surface area is 120–878 m²/g. Aerogels are characterized by a high degree of porosity: the pore volume attains 1–4 cm³/g. Based on precursor xerogels, nanopowders of a tetragonal solid solution of the (ZrО₂)_0.92(Y₂О₃)_0.03(CeО₂)_0.05 composition with a particle size of 5–9 nm and S _spec = 74 m²/g were fabricated. Due to the high values of their specific surface area, the synthesized xerogels and aerogels are promising as sorbents, catalysts, or catalyst supports.     

High-temperature luminescence in an n-GaSb/n-InGaAsSb/p-AlGaAsSb light-emitting heterostructure with a high potential barrier

The electroluminescent properties of an n-GaSb/n-InGaAsSb/p-AlGaAsSb heterostructure with a high potential barrier in the conduction band (large conduction-band offset) at the n-GaSb/n-InGaAsSb type-II heterointerface (ΔE _c = 0.79 eV) are studied. Two bands with peaks at 0.28 and 0.64 eV at 300 K, associated with radiative recombination in n-InGaAsSb and n-GaSb, respectively, are observed in the electroluminescence (EL) spectrum. In the entire temperature range under study, T = 290–480 K, additional electron-hole pairs are formed in the n-InGaAsSb active region by impact ionization with hot electrons heated as a result of the conduction-band offset. These pairs contribute to radiative recombination, which leads to a nonlinear increase in the EL intensity and output optical power with increasing pump current. A superlinear increase in the emission power of the long-wavelength band is observed upon heating in the temperature range T = 290–345 K, and a linear increase is observed at T > 345 K. This work for the first time reports an increase in the emission power of a light-emitting diode structure with increasing temperature. It is shown that this rise is caused by a decrease in the threshold energy of the impact ionization due to narrowing of the band gap of the active region.     

MIS-sensors with different metal and insulator layers

Several modifications of MIS-sensors manufactured using the thin-film laser evaporation technology with different insulator layers and metal electrodes are presented. Metrological characteristics of these MIS-sensors are established. Two types of the sensors possessing abnormally high and low sensitivities to H₂, H₂S, NO₂ and NH₃ are identified; the stated types are of practical interest in applications as sensitive elements of gas analyzers. Finally, the presence of catalytic properties in metal electrodes is demonstrated to be not necessary for sensitivity of the devices. This fact seems important for developing the microscopic theory of sensitivity of MIS-sensors.     

Immature Vascular Smooth Muscle Cells in Healthy Murine Arteries and Atherosclerotic Plaques: Localization and Activity

The local development of atherosclerotic lesions may, at least partly, be associated with the specific cellular composition of atherosclerosis-prone regions. Previously, it was demonstrated that a small population of immature vascular smooth muscle cells (VSMCs) expressing both CD146 and neuron-glial antigen 2 is postnatally sustained in atherosclerosis-prone sites. We supposed that these cells may be involved in atherogenesis and can continuously respond to angiotensin II, which is an atherogenic factor. Using immunohistochemistry, flow cytometry, wound migration assay xCELLigence system, and calcium imaging, we studied the functional activities of immature VSMCs in vitro and in vivo. According to our data, these cells do not express nestin, CD105, and the leptin receptor. They are localized in atherosclerosis-prone regions, and their number increases with age, from 5.7% to 23%. Immature VSMCs do not migrate to low shear stress areas and atherosclerotic lesions. They also do not have any unique response to angiotensin II. Thus, despite the localization of immature VSMCs and the presence of the link between their number and age, our study did not support the hypothesis that immature VSMCs are directly involved in the formation of atherosclerotic lesions. Additional lineage tracing studies can clarify the fate of these cells during atherogenesis.