Abstract: A stable cross-linked alginate gel such as in the form of alginate gel beads encapsulating transplant materials is produced by binding surplus multivalent cations remaining after cross-linking alginate with the cations. A cross-linked alginate gel containing the surplus cations is contacted with a solution of multivalent anions such as sodium sulfate solution to bind the surplus cations. Preferably, a dehydration preventing agent such as protein, bone powder or implant substances is present during cross-linking. A hydrophobic substance such as a perfluoro hydrocarbon or an emulsion may be present during cross-linking to fill spaces between alginate chains. Alginate gel beads produced by the process have long term stability after transplanting.

Abstract: A process for treating a biological or synthetic object subjected to an electrical field in a surrounding liquid medium for a predetermined pulse time (t1), the electrical field being formed by at least two electrodes including actuating at least once during the pulse time (t1) each of the electrodes as an anode and as a cathode, to cause at each electrode a polarity reversal and alternating electrolytic increases and reductions in pH of at least a portion of the liquid medium, subjecting the object during the pulse time (t1) to a number of electrical partial pulses which have a frequency in the range of 1 kHz to 1 MHz and which possess partial pulse durations, with sequentially reversing polarity or field direction such that the partial pulses possess sequentially varying partial pulse durations (t11, t12), pulse forms, and/or pulse amplitudes, and selecting the partial pulse durations (t11, t12), pulse forms, and/or pulse amplitudes such that, due to the electrolytic increases and reductions in pH value, su

Abstract: The memory cell configuration has a large number of memory cells provided in a semiconductor substrate and having bit-line trenches which extend in parallel in the longitudinal direction in the main face of the semiconductor substrate, at the bottoms of which in each case a first conductive region is provided, at the peaks of which in each case a second conductive region of the same conduction type as the first conductive region is provided, and in the walls of which in each case an intermediately located channel region is 0 provided; and having word lines which extend in the transverse direction along the main face of the semiconductor substrate, through specific bit-line trenches, to activate transistors provided there. An additional dopant is introduced into the trench walls of the bit-line trenches which are located between the word lines, in order to increase the corresponding transistor turn-on voltage there to suppress leakage currents.

Abstract: Biologically active substances such as cells or tissue are microencapsulated by methods that provide a high proportion of microcapsules containing a core of the biologically active substance as compared to microcapsules not containing the biologically active substance. Microcapsules are obtained having a maximum diameter of 300 micrometers and a high concentration of biologically active substance. A solution of encapsulating material such as alginate containing dispersed biologically active substance is passed through an inner channel of a two-channel spray nozzle to form droplets containing a core of the biologically active substance. Air flow from an outer channel of the nozzle causes the droplets to break off from the nozzle. Conditions of air flow and flow rate of solution are selected to obtain droplets having a volume of 1.5 to 4 times the volume of the biologically active substance that forms the core.

Abstract: A crosslinking agent for crosslinking ionotropic gels by linking gel molecules by counterion bridges contains the counterions in a state wherein they are bound to a carrier substance. The counterions can be released from the carrier substance under the external influence of a substance, temperature or radiation. For crosslinking of the gel, first a mixture of the gel molecules to be crosslinked and the crosslinking agent is prepared, a molded body is produced from this mixture and then crosslinking of the gel molecules is induced by the release of the counterions from the carrier substance through the external influence of a substance, temperature or radiation.

Abstract: A semiconductor read-only memory (ROM) has trenches and vertical transistors. The trenches are filled with insulator material during the manufacturing process. Holes, which are as wide as the trenches are etched into the insulator at regions where word lines and decoder lines are to be provided over the trenches in a later manufacturing step. In a subsequent masking process for changing the conductivity characteristic of channel regions of transistors, channel regions selected according to programming requirements, are doped. The insulator remaining in the trenches prevents that regions under the insulator material are affected by the masking method.

Abstract: A process for electrofusion of dendritic cells with abnormal cells, particularly tumor cells, that achieves a higher yield of fusion product, as well as a media that can be used in the process. The dendritic cells are combined with tumor cells and washed, if necessary, with a washing medium and then centrifuged. The resulting pellet is suspended in an electrofusion medium and then treated by electrofusion. The electrofusion medium contains sugar (20 mM/L to 150 mM/L), magnesium salt (0.05 mM/L to 1 mM/L) and calcium salt (0.01 mM/L to 1 mM/L), in pyrogen-free, sterile distilled water. The washing medium is a solution containing sugar (270 mM/L to 310 mM/L), magnesium salt (0.05 mM/L to 1 mM/L) and calcium salt (0.01 mM/L to 1 mM/L), in pyrogen-free, sterile distilled water.

Abstract: A semiconductor device includes a plurality of bitlines arranged in an array, the plurality of bitlines being grouped in pairs and at least some of the bitlines include a twist. A twist region is disposed along the plurality of bitlines wherein the twist region occupies layout area designated for the twists. An equalizer element is disposed in the twist region for equalizing a pair of bitlines.

Abstract: A read-only memory cell array has vertical MOS transistors formed on trench walls, and is programmed with a programming mask which covers only the areas at which a transistor is not to be produced. As a result, the word lines can be formed with minimum grid spacing and the risk of short-circuiting between adjacent word lines is eliminated by buried ploy stringers.

Abstract: A trench capacitor cell, in accordance with the present invention, includes a trench having an outer electrode formed in a substrate adjacent to the trench. A storage node is formed in the trench and capacitively coupled to the outer electrode. A center node is capacitively coupled to the storage node, and the storage node surrounds the center node within the trench. The center node includes a portion extending from the trench for connecting to a potential to provide charge retention in the storage node during operation.

Abstract: Proposed is a mitogen-free substance comprising cross-linked copolymers including 10 to 90 mole % of guluronic acid, the balance being made up of mannuronic acid. The substance has a molecular weight of from 10,000 to 500,000 Daltons. Also proposed are methods for preparing such substances and their use.

Abstract: Disclosed is a process and device for fusing cells in which the cells are doped with magnetic particles and exposed to a nonhomogeneous magnetic field which permeates the fusion space in such a way that the doped cells collect close together, and then, in order to create the disruptions in the membrane structures of the adjacent cells, the cells are exposed either to the pulse of an electric field of at least the level of the breakdown voltage or to chemicals which cause the disruptions in the membrane structure such as polyethylene glycol, or to inactivated viruses which cause the disruptions in the membrane structure such as Sendai viruses.

Abstract: Disclosed is a process and device for facilitating the differentiation of particles in a medium. The particles, which belong to at least two different groups of particles, are enclosed in a chamber bounded by electrodes which produce a rotating electrical field. A means for producing two rotating electrical fields having opposite directions of rotation and variable rotational frequency is provided to be attached to the electrodes. The particles exposed to the rotating electrical field forces with opposite directions of rotation can be differentiated on the basis of their rotational behavior.

Abstract: Disclosed is a process and device for fusing cells in which the cells are doped with magnetic particles and exposed to a nonhomogeneous magnetic field which permeates the fusion space in such a way that the doped cells collect close together, and then, in order to create the disruptions in the membrane structures of the adjacent cells, the cells are exposed either to the pulse of an electric field of at least the level of the breakdown voltage or to chemicals which cause the disruptions in the membrane structure such as polyethylene glycol, or to inactivated viruses which cause the disruptions in the membrane structure such as Sendai viruses.

Abstract: Plant protoplasts are suspended in a solution of sodium alginate which is thereafter thickened by the addition of a soluble calcium or lanthanum salt to produce a matrix with large pores permeable to water and gas in which the protoplasts are held. The resulting material, in tape or spheroid form, when stored in a nutrient solution, will prolong the senescence of the protoplasts and increase their sensitivity to polluting materials. When such ribbons or particles are exposed to a polluting environment for a particular period of time, the effect of pollution can be detected by measuring the evolution of ethane or measuring the blocking of the enzyme ribulose-diphosphate-carboxylase, in the latter case using carbon dioxide marked with .sup.14 C. A control experiment in which an identical indicator treated in an equivalent environment without pollutants reveals, by comparison, the effect of the pollution.

Abstract: Disclosed is a process and device for facilitating the differentiation of particles in a medium. The particles are exposed to a rotating electrical field of variable rotational frequency. By providing a means for adjusting the frequency of the rotating fields, the particles can be caused to rotate in different directions thereby facilitating differentiation of particles belonging to different groups of particles. An apparatus for implementing this process includes at least three electrodes which are arranged so as to form a space therebetween. A device for producing a rotating field of variable rotational frequency is connected to the electrodes.

Abstract: Disclosed is a process and device for determining which cells of a suspension containing cells of the same species and genus are secreting cellular substances. Such determinations are made by exposing the cells to rotating electrical field forces of variable rotational speed and differentiating the cells secreting the cellular substances from the other cells by means of their rotational behavior which differs from that of the other cells.

Abstract: The present invention relates to a method involving enzymatic catalyzed chemical reactions with substrates dissolved in an aqueous solution by means of enzymes. Membrane vesicles, loaded with the enzymes, are placed into the aqueous solution. The substrates move into the membrane vesicles where they are decomposed by means of the enzymes trapped in the vesicles. The substances produced by decomposition move out of the vesicles into the aqueous solution. Finally the decomposed substances are separated from the aqueous solution.

Abstract: A method and adsorption medium for isolating and purifying enzymes from a crude enzyme solution of animal organs or tissues. An adsorption medium for bringing about the binding of a predetermined enzyme is introduced into the crude enzyme solution and is left therein until the binding takes place, whereupon the adsorption medium is removed from the crude enzyme solution and the enzyme is separated from the adsorption medium by extraction or elution with a suitable solution. The adsorption medium is in the form of membranes of human or animal erythrocytes which have been hemolyzed by osmosis. Those enzymes which have the same or nearly the same affinity as regards binding on the membranes as does the predetermined enzyme which is to be bound are separated from the membranes prior to introducing the membranes into the crude enzyme solution. The amount of the enzymes first removed that is bound being less than the amount of erythrocytes used to form the membranes.

Abstract: A mass, and method of preparing such mass, and using the same for adsorbing metal ions from a physiological solution by means of living cells suspended in the solution. The cells suspended in the solution at a density of up to 20% by weight are exposed to an electric field of such intensity and over such a period of time that the membrane of the cells will be so changed that substances present in the interior of the cells and having a diameter within the range of from 2 to 50 A, such as potassium and proteins, pass from the interior of the cells into the physiological solution. The electric force or intensity is limited in such a way that the changes in the membrane of the cells can be healed by regeneration of the cells. The mass is introduced into the aqueous solution, such as sea water, lake water or waste water, and left therein until the mass as adsorbed therefrom the metal at a desired concentration, whereupon the mass is separated from the aqueous solution.