Catheter-tip sensors used to measure arterial and tissue PCO2 produced a baseline drift less than 2 torr during 1 to 5 h of monitoring. Clot formation during PaCO2 monitoring was avoided by ...continuous infusion of a small amount of heparin solution around the sensor. PaCO2 sometimes fluctuated periodically during spontaneous breathing but not during mechanical ventilation. Subcutaneous tissue PCO2, monitored by placing the sensor under the skin on the chest, showed an almost parallel movement to PaCO2 with a time delay of a few minutes. This PCO2 sensor was durable and accurate for up to 5 h continuous clinical monitoring.
Because a parallel mechanism has a high-frequency response, multiple degrees of freedom (DOF), and high stiffness, it can be applied to an end effector for electrical discharge machining (EDM) with a ...scanning motion. A prototype has 3 DOF: two tilting angles around the
x- and
y-axes, and the movement in the
z-direction. It consists of, a base plate, a stage, a constraint link, and three inchworm devices that act as links. The inchworm devices are connected with the stage and the base plate. The
z-position and inclination of the stage are changed by adjusting the length of the inchworm devices. The electrode feeding is controlled by the combination of the steplike movement with the inchworm devices and continuous extension of piezos. The frequency response of the stage by the continuous extension of the piezos is up to 200 Hz. The positioning accuracy of the end effector is less than 30 μm in height and 0.04° in inclination. Some examples of EDM by the scanning motion are demonstrated.
The purpose of this paper is to introduce a hydrogel which shows improved mechanical properties. Reinforced hydrogels were prepared from graft copolymers having hydrophobic segments. The graft-type ...copolymers were prepared by the copolymerization of 2-hydroxyethyl methacrylate or vinyl acetate with polystyrene which has a polymerizable double bond at a chain end. When vinyl acetate was employed, poly (vinyl acetate) portions were converted to poly (vinyl alcohol) by hydrolysis. As the result, these copolymers have comb-like branched structures. In these copolymers in bulk, polystyrene chains aggregate to form separate domains (200-300Å). When the copolymers are soaked in water to form a hydrogel, the hydrophobic domains seem to serve as cross-linking points or as reinforcing fillers in the hydrogel. The hydrogels show good thrombo-resistant property in vitro experiments.
Although these studies are preliminary, they do not show that the chemical structure of the block copolymer is not the only determinant of its blood properties; one must be equally concerned with the ...effect of its domain-matrix size and purity. These features, which are affected by factors such as block size, mold surface, and general fabrication procedures, as well as chemical structure, must be controlled if one is to have reproducible results in the function of an implant.
A measurement of the proton spin structure function
g
1
p(
x,
Q
2) in deep-inelastic scattering is presented. The data were taken with the 27.6 GeV longitudinally polarised positron beam at HERA ...incident on a longitudinally polarised pure hydrogen gas target internal to the storage ring. The kinematic range is 0.021<
x<0.85 and 0.8 GeV
2<
Q
2<20 GeV
2. The integral
∫
0.021
0.85
g
1
p
(x)
dx
evaluated at
Q
0
2 of 2.5 GeV
2 is 0.122±0.003(stat.)±0.010(syst.).
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