Variations of histamine concentration in sleep and arousal hemodialysates (seasonal, thalamic and reticular influences)

In hemodialysates of cerebral venous blood from rabbits kept asleep by electrical stimulation of the somnogenic intralaminar thalamus, a seasonal correlation was found between the histamine (H) concentration and the external daily temperature, with a minimum in winter and a maximum in summer. By contrast, in dialysates of rabbits aroused by electrical stimulation of the midtrain reticular formation, the H concentration reached in winter the same high level as in summer. During the winter, stimulation of the waking midbrain reticular system increased the H-level of the cerebral blood dialysate, whereas that of the somnogenic intralaminar thalamus did not enhance, sometimes even lowered, the H-concentration. This suggests that the mechanism of H release in blood might be associated with the midbrain activating reticular system and moderated by the intralaminar thalamus.     

X-ray topographic study of dislocations in KH2(1−x)D2xPO4 single crystals

Dislocations in heavily deuterated DKDP single crystals were examined by the Lang technique, and their characteristics were compared with those of the KDP isomorph species. The influence of dislocations on the operation of DKDP targets in large-screen display devices is discussed. The origin of dislocations which takes place during the growth habit formation is briefly discussed.     

Separator materials for use in alkaline water electrolysers

Separator materials suitable for use in industrial alkaline water electrolysers are surveyed, including both inorganic and organic materials. The properties which make asbestos diaphragms unsuitable for use above 100°C are also reviewed.In summary, potassium titanate and polyantimonic acid separator materials perform well in high-temperature alkali. Oxide-coated metallic diaphragms merit further attention. Polysulfone and polyphenylene sulfide polymers are promising, but will need definite improvement in their wettability. Asbestos stabilization by silicate electrolyte additions may be viable.     

Numerical analysis of simultaneous diffusion of several impurities in silicon and silicon dioxide

An iterative method to simulate the diffusion phenomena in semiconductor technology is presented. With the computer programs described here, it is possible to obtain accurate values of the impurity concentrations in semiconductor devices directly from technological parameters, such as diffusion temperatures and various elementary times in the process.     

Un environnement de conception de systèmes distribués basé sur UML

This paper introduces a new environment for developing distributed systems. It is based on theTurtle uml profile. Analysis and design phases, described in previous papers, have been extended with an additional deployment phase. In this new step,Turtle components are deployed over hardware execution nodes, and nodes are connected together throughout links,Turtle deployment diagrams are given a formal semantics inRt-lotos, therefore following the approach used forTurtle analysis and design diagrams. Moreover, the paper presents a Java code generator which outputs appropriate Java code forTurtle deployment diagrams. This code is automatically deployable on networks because it implements node communication using network protocols such asUdp orRmi. ttool, the turtle toolkit has been extended to support these new diagrams and code generators. The attack of protected data exchanged throughout securedHttp sessions serves as example.     

Cell culture imaging using microimpedance tomography

We present a novel, inexpensive, and fast microimpedance tomography system for two-dimensional imaging of cell and tissue cultures. The system is based on four-electrode measurements using 16 planar microelectrodes (5 microm x 4 mm) integrated into a culture chamber. An Agilent 4294A impedance analyzer combined with a front-end amplifier is used for the impedance measurements. Two-dimensional images are obtained using a reconstruction algorithm. This system is capable of accurately resolving the shape and position of a human hair, yielding vertical cross sections of the object. Human epithelial stem cells (YF 29) are also grown directly on the device surface. Tissue growth can be followed over several days. A rapid resistivity decrease caused by permeabilized cell membranes is also monitored, suggesting that this technique can be used in electroporation studies.