摘要:
Disclosed are one-piece, funnel shaped balloon holders, comprising a conical cup and a hollow cylindrical stem. A longitudinal slit extends the entire length of the balloon holder, from the upper edge of the cup to the lower end of the stem, to permit insertion of the neck of a balloon into the holder. A short slot at the bottom of the stem anchors the balloon tail. In a first embodiment (FIGS. 1-3), a balloon stick is inserted into the hollow stem. In a second embodiment (FIGS. 4-8) the stem is inserted into one end of a hollow balloon stick. The stem in this embodiment is of such shape as to provide space between the stem and the balloon stick for a portion of the balloon neck so that the entire balloon neck is concealed.
摘要:
1-Alkyl- or 1-cycloalkylpiperazines are prepared by reacting piperazine with an alkanol or cycloalkanol in the presence of hydrogen and a hydrogenation/dehydrogenation catalyst by a process in which the reaction is carried out at from 130.degree. to 190.degree. C. under from 5 to 100 bar in the presence of from 5 to 40% by weight, based on the reaction mixture, of water, and the molar ratio of piperazine to alkanol or cycloalkanol is kept at from 1:1.5 to 1:8.
摘要:
Hydroxyl-containing polymers are prepared by catalytic hydrogenation of acyloxy-containing polymers by a process in which a strong base is added to the acyloxy-containing polymers before or during the hydrogenation.
摘要:
The invention relates to an electrode assembly 20, in particular for applying at least one electric field to adherent cells, comprising at least two electrodes 21, each having at least one surface 32 which is arranged opposite the corresponding surface 32 of the other electrode 21, wherein an electrically insulating material 26 is arranged at least partially between the surfaces 32 of the electrodes 21. The solution according to the invention allows the electric field to be concentrated in the region of the cells to be treated such that a voltage pulse, or the current produced thereby, flows through the cells without the majority flowing away over the cells unused in the electrolyte. The invention further relates to a method for applying at least one electric field to adherent cells, in which the electric field is generated by applying a voltage to at least two electrodes, the electric field is concentrated on the side of the electrodes which faces the cells and/or is limited to the space between the cells and the side of the electrodes which faces the cells.
摘要:
A device (1) for transferring a preferably band-shaped weft material (6) from a feed unit to an insertion element (4) of a weaving machine comprises a clamping device (5) for clamping a free end (E) of the weft material (6). The clamping device (6) is conveyable essentially in the direction (BR) of motion of the insertion element (4) between at least two different operating positions. The device (1) includes a drive (8) for conveying the clamping device (5). In a method for transferring a preferably band-shaped weft material (6) from a bobbin or a feed unit to an insertion element (4) of a weaving machine, a free end (E) of the weft material (6) is clamped in a clamping device (5), the free end (E) is transferred to the insertion element (4), and then the clamping device (5) is opened and the weft material is inserted. The clamping device (5) is conveyed by means of a drive (8) essentially in the direction of motion of the insertion element (4) between at least two different operating positions.
摘要:
A method for introducing biologically active molecules into animal or human cells using an electric current includes suspending the cells and dissolving the biologically active molecules in a buffer solution including HEPES and at least 10 mmol×1−1 magnesium ions (Mg2+), the buffer solution having a buffer capacity of at least 20 mmol×1−1×pH−1 at a change in the pH from pH 7 to pH 8 and at a temperature of 25° C., and an ionic strength of at least 200 mmol×1−1. An electric voltage is applied to the suspension.
摘要:
Disclosed is a method for treating biological material via electrical current, in which the biological material is added to a small volume of a buffer solution having relative high ionic strength. A strong electrical field is generated in the buffer solution by a high voltage pulse having a preset duration. The biological material is added to at most 50 μl of a buffer solution with an ionic strength of at least 100 mmol/l. By at least one voltage pulse having a preset duration of at least 10 μs, an electrical field with a field strength of at least 1 kV/cm is generated in the buffer solution. The voltage pulse is hereby interrupted at least once for a duration of at least 100 μs and is then again continued.
摘要:
A controlled weft thread presenting and clamping arrangement minimizes weft thread waste and ensures proper tensioning of the weft thread during its presentation to the insertion gripper, in a gripper loom for weaving with plural different weft threads. The arrangement includes a control shaft (13) that has a drive key (14) protruding therefrom in a reference plane (7), and that is rotatably supported on a support bracket (10, 11, 12), which may be mounted on the loom. Weft thread presenting levers (15) each carrying a respective clamp (16) are movably arranged on the shaft (13), which passes through a hole in each of the presenting levers (15). A translational drive (22) acts on a presenting lever support (17) to translationally move all of the presenting levers (15) in unison together axially along the shaft (13) until a selected lever (15) is positioned in the reference plane (7), with the lever's drive groove 15B engaged on the drive key (14) of the shaft (13). A rotational drive (23) rotates the shaft (13), and therewith the selected thread presenting lever (15) via the drive key (14). A guide member (19) has a lengthwise groove (20) to allow all of the presenting levers (15) to move linearly therealong in unison, and a crosswise groove (21) in the reference plane (7) to allow only the selected presenting lever (15) to rotate in the reference plane. A thread back tensioning device (9) is arranged in the thread path to apply tension to the thread being presented to the gripper.
摘要:
In the event of an interruption of the weaving process and in the case of weaving-technical operations, such as tabby weaving and unraveling, a trailing of warp thread bobbins and thus a trailing of warp threads which are withdrawn from the bobbins and form a warp thread family, cannot be avoided without significant expenditures. The trailing results in a so-called trailing length in the thread family which, unless it is correspondingly taken up and correspondingly released during the new start of the weaving process, results in an overstretching of the warp thread family during a starting operation of the bobbins. This disadvantage is avoided by deflecting the thread family within a feeding stand, in the event of a weaving stop, in a controlled manner from a reference plane into at least one defined position. At the new start of the weaving process, the deflection is eliminated in a controlled manner.