Ultrasonic monitoring of foamed polymeric tissue scaffold fabrication.

Polymeric tissue scaffolds are central to many regenerative medicine therapies offering a new approach to medicine. As the number of these regenerative therapies increases there is a pressing need for an improved understanding of the methods of scaffold fabrication. Of the many approaches to processing scaffolds, supercritical fluid fabrication methods have a distinct advantage over other techniques as they do not require the use of organic solvents, elevated processing temperatures or leaching processes.

High-accuracy data acquisition architectures for ultrasonic imaging.

This paper proposes a novel architecture for a data acquisition system intended to support the next generation of ultrasonic imaging instruments operating at or above 100 MHz. Existing systems have relatively poor signal-to-noise ratios and are limited in terms of their maximum data sampling rate, both of which are improved by a combination of embedded averaging and embedded interleaved sampling. "On-the-fly" pipelined operation minimizes control overheads for signal averaging.

Characterization of nanoscaled heterogeneities in mechanically alloyed and compacted CuFe.

Cu80Fe20 and Cu50Fe50 were mechanically alloyed from the pure elements by ball milling for 36 h. The alloy powder was compacted into tablets at room temperature by applying a pressure of 5 GPa. Characterization of the Cu80Fe20) and Cu50Fe50 alloys was carried out by high-resolution transmission electron microscopy (HREM), atom probe field ion microscopy and three-dimensional atom probe (3DAP).

[The stimulation of reparative regeneration with demineralized bone matrix in puncture osteoplasty operations for bone cysts in children].

The authors present the data on positive influence of demineralized osteomatrix (DOM) on the osteogenesis in the experimental conditions. On the basis of data received the method of puncture osteoplastic operation with DOM application was developed. Puncture method was applied in 38 children.

[The effect of hypothermia and oxygenation on the cardiorespiratory system in man exposed to experimental weightlessness].

It has been established that hypothermia in experimental weightlessness, as compared to normal conditions, was characterized by a considerably smaller deficit of erythrocytes in the energy balance and reduced gas exchange level, despite unidirectional changes in hemodynamic parameters. Unlike in hypothermia, an increase in oxygen concentration in the inhaled gas mixture had no noticeable effect on the parameters of the cardiorespiratory system studied.

[Metabolic changes in simulated weightlessness].

8 healthy subjects participated in 2 series of experiments on the comparative studies of two techniques of respiratory therapy employing multicomponent anesthesia during controlled lung ventilation in normal conditions and in experimental weightlessness. It has been established that experimental weightlessness, as compared to normal conditions of controlled lung ventilation, was more favourable for the maintenance of effective energy exchange in erythrocytes and tissue O2 consumption. Both techniques of respiratory therapy during controlled lung ventilation are recommended in these conditions.

[Energy metabolism in the erythrocytes of humans exposed to anti-orthostatic hypokinesia].

Energy metabolism in red blood cells of men exposed to antiorthostatic hypokinesia (-8 degrees) was investigated. It was found that during this exposure erythrocytes synthesized organic phosphates such as diphosphoglyceric acid (2,3-DPG), ATP and ADP that were similar in terms of their effect on hemoglobin affinity for oxygen. On hypokinesia day 6, when the oxygen concentration in the erythrocyte environment increased, the content of the above phosphates also grew.

[Clinico-physiological aspects of the tissue oxygen supply of the human body during head-down tilt hypokinesia].

In three antiorthostatic hypokinesia studies of varying duration gas exchange, central and regional hemodynamics were investigated. The hypokinetic effect on oxygen changes in the human body was evaluated by comparing the above results with biochemical data. It is concluded that bed rested subjects developed hypoxic changes of mixed circulatory-respiratory type.

[Status of metabolism and peripheral circulation in man during antiorthostatic hypokinesia].

Metabolism and peripheral circulation were investigated in head-down tilt tests of varying duration. The greatest changes were seen on test day 30 when the subjects showed venous hyperoxia, lower oxygen arterio-venous difference and a significant (p less than 0.05) decrease of oxygen tension in arterial blood and oxygen utilization in tissues (p less than 0.