The present invention provides a cell-culturing model and a method for screening compounds which can be applied in treating or preventing hepatic cirrhosis. The cell culturing model comprises a population of hepatocytes and hepatic stellate cells (HSCs) derived from co-culturing, and at least one population of the cells comprises a nucleotide sequence fragment of a reporter gene and a cell specific regulatory sequence. The cell-culturing model of the present invention can be applied in high throughput screening for effective compounds of medication, and also in understanding the functional mechanism of the effective compounds.

1. Field of the Invention
The present invention relates to a cell culturing model and a method for drug screening, more particularly, to a cell culturing model and a method using modified liver cells and hepatic stellate cells in high throughput drug screening for hepatic cirrhosis treatment.
2. Description of Related Art
Hepatic cirrhosis is often resulted from the damage to hepatocytes by alcohol and drugs, or virus infection. Damaged hepatocytes release certain signals to activate hepatic stellate cells (HSCs) in liver tissue into myofibroblasts (MFs). MFs are capable of secreting large varieties of extracellular matrix (ECM), including collagen, fibronectin, laminin and proteoglycan. The accumulation of excess extracellular matrix causes liver fibrosis. In the meantime, accumulated extracellular matrix further obstructs hepatocytes from the supply of oxygen and nutrients, and therefore leads to necrosis. To sum up, hepatic cirrhosis is the result of necrosis of hepatocytes and excessive secretion of extracellular matrix by HSCs, due to the imbalance between the rates of degradation and bio-synthesis of extracellular matrix.
Screening methods for anti-hepatic cirrhosis drugs include in vitro screening by cell culture and in vivo screening by animal models. In vitro screening method by cell culture often uses single type of cells, such as HepG2 cell-line, primary rat hepatocytes, or Chang liver cells derived from human liver. Liver-protecting drugs are treated on the alcohol, carbon tetrachloride (CCl4) or α-galactosamine (Galn) damaged cells, and albumin production, MTT analysis, and the activities of glutathione-S-transferase (GST) or cytochrome P450 are measured, which serve as indication of the recovery of damaged cells. Besides, HSCs or MFs can also be used to observe how the drug inhibits their activities. The expression of α-actin and desmin, collagen production, and the activities of MMP-3 (matrix metalloproteease-3) or -9 usually serve as indicators.
Mice, rats, rabbits and canines are commonly used as animal models for liver protecting drug screening. Acute or chronic hepatic cirrhosis can be induced by the treatment of CCl4or Galn, bile duct ligation or Schistosoma japonicum infection. Recovery of liver damaged animals are observed after administering liver-protecting drugs.
However, using animal experiments to demonstrate the efficacy of newly synthesized drugs conflicts he aspects of economy and humanity. Current in vitro cell model uses single type of cells only, either hepatocytes or HSCs, which is not in accordance with the physiological condition of hepatic cirrhosis. Deviation is likely to occur. A selected drug with therapeutic efficacy should be able to enhance the function of hepatocytes, and also inhibit the activation of HSCs and the production of extracelluar matrix. Therefore, it is necessary to develop an appropriate cell model in accordance with the physiological condition of cirrhotic livers.
Present high throughput screening apparatus for new drugs uses single type of monolayer cells. Monolayer-cells cannot display the real physical condition, not to mention performing screening on several types of cells at the same time. As a result, the actual function and the tissue specificity of the drug cannot be accurately detected, and therefore cause the omission of other important uses which will lead to the misconception of effectiveness. This is also the reason for criticism of the high-speed screening technique for new drugs.
The invention is to develop a cell-culturing model for high throughput screening anti-hepatic cirrhosis drugs. The fluorescence released from reporter genes in genetic modified hepatocytes and HSCs can be detected by a fluorescence reader, which provide a quick and sensitive platform for real-time examination of cell condition and therefore increase the accuracy of drug screening. Experiments on animals may also be replaced in the future to significantly decrease the costs and time for developing a new drug screening.

Cell culture and method for screening for a compound useful in the treatment or prevention of hepatic cirrhosis

Industrial Technology Research Institute


The invention makes available a process for preparing a protein hydrolysate from protein containing animal products, in which process the animal products are hydrolysed using endopeptidases and exopeptidases. The process is characterized in that smoked, protein containing animal products are employed as protein containing animal products. By using smoked, protein containing animal products, a protein hydrolysate can be produced which does not have the bitter flavor which arises during the customary hydrolysis of protein containing animal products. Smoked pork rind is preferably employed for the hydrolysis.

The hydrolysis of meat with industrial enzyme preparations, such as proteinases, for the purpose of producing a protein hydrolysate or a flavor-imparting meat extract is disclosed in the state of the art, for example, in WO 94/01003, EP-A 505 733 and DE-A 28 41 043. The use of alkaline or neutral endopeptidases, such as Alcalase (NOVO) or Pescalase (GIST), of bacterial origin for the purpose of producing oligopeptide-rich hydrolysates from plant proteins, and also whey proteins and egg proteins, is also described, for example, in EP-A 511 970. The use of an endopeptidase and exopeptidase enzyme preparation (Flavorzyme) (NOVO), which is obtained from fungi, is described in WO 94/25580. In this case, protein hydrolysates having a relatively high degree of hydrolysis are produced from plant proteins and also from fish proteins and meat proteins, including gelatin.
The enzymic hydrolysis of protein from meat adhering to bones is well known in the state of the art and is nowadays carried out in meat-processing concerns with the aim of ensuring that residual material is fully utilized. This is known, for example, from H. Uhlig, Enzyme arbeiten fur uns (Enzymes work for us), 1991, Hanser Verlag, pp. 325 ff., J. Adler-Nissen, Enzymic Hydrolysis of Food Proteins, 1986, Elsevier Appl. Sc. Pub., pp. 90 ff. or Behnke et al., Nahrung, 28: 397-407, 1984. Residual materials from fish processing can also be used, with it being possible to use the fish's own enzyme system, as described in EP-A 535 135.
A fundamental problem in the enzymic hydrolysis of animal protein is the formation of a bitter flavor due to peptide fragments. In order to solve this problem, the state of the art proposes, for example in EP-A 223 560, employing proteolytic enzyme combinations consisting of endopeptidase and exopeptidase mixtures and aminopeptidases for degrading the resulting bitter tasting peptides. Furthermore, WO 94/01003, proposes adherence to a given degree of hydrolysis and the use of raw meat instead of the boiled commodity. DE-A 30 03 679 proposes masking the bitter-tasting substances with additives such as carbohydrates. Possibilities of avoiding or masking the bitter flavor are discussed in Food Technology, 48: 96-98 (1994).
The enzymic hydrolysis of collagen-rich material, for example gelatin, is likewise disclosed. The products which are obtained in this case are not so bitter as those obtained during the enzymic hydrolysis of meat. However, in this case, it is often only a partial hydrolysis of the protein, with a low degree of degradation, which is sought. The possible enzymic hydrolysis of rind and bones for the purpose of obtaining gelatin would be such an application. However, this application has up until now not been able to compete with the traditional disruption with acid and alkali because it is difficult to control the degree of hydrolysis precisely. The impression that enzymic gelatin hydrolysates have a flavor which is less bitter is due, inter alia, to the proportion of free amino acids which are possessed by collagen-rich material which do not taste particularly bitter. In particular, this material contains sweetly tasting amino acids such as glycine and less bitter tasting arginine.
Experiments for preparing hydrolysates from collagen-rich material are described, inter alia, by Lin and Chen, Proc. of AAAP 2: 1112-1114 (1985) and in JP-A 52 110874 and JP-A 52 099265. Collagen-rich hydrolysates can be obtained commercially (Marggrander, Fleischwirtschaft 75: 1286-1287 (1995)).
A hydrolysate prepared from collagen is also described in DE-A 25 37 618. In this case, a non-bitter product having a molecular weight of greater than 2000 daltons is obtained by hydrolysis in the alkaline range. DE-A 36 20 150 describes a collagen hydrolysate in the molecular weight range of 15,000 daltons as a replacement for common salt. U.S. Pat. Nos. 4,130,555 and 3,743,514 propose collagen hydrolysates prepared from gelatin and rind for protein enrichment in sausages.
However, if an attempt is made to hydrolyse protein-containing animal products, in particular raw or boiled pork rind, with this latter also being a collagen-rich material, for example using endopeptidases in this way, it is observed that, from a particular hydrolysis time onwards, markedly bitter tasting hydrolysates are to be expected, both in the case of the raw commodity and in the case of the boiled commodity, as the degree of hydrolysis increases. The bitterness can only be forced below the perception threshold when the degree of liquefaction is quite low, i.e., when the hydrolysis time is short, and when assisted by common salt, which serves to mask the bitter taste. The same problem arises when air-dried rind is hydrolysed. It is also found that hydrolysates prepared from fresh ham taste astringent, bitter and acid irrespective of whether the ham is raw or boiled.
Consequently, an object of the invention is to make available a process for preparing a protein hydrolysate which, even without masking and despite a high degree of liquefaction and a long hydrolysis time, does not taste bitter and which consequently constitutes an advantageous flavorant.

Process for preparing a protein hydrolysate from protein containing animal products


A versatile book is disclosed for hanging pneumatically actuated devices (e.g., airguns or spray guns). In the preferred embodiment, the versatile hook comprises: a hook body having a base with an annular section that defines a through-space corresponding to the shape of the pneumatic device's cylindrical extension tube or barrel; a hook-shaped extension attached to the body; and, positioning-and-mounting means for selectively positioning the hook, around and along the barrel, and thereafter mounting the body in a temporarily fixed position onto the barrel, with the hook-shaped extension facing towards or away from the discharge nozzle. Upon loosening a bolt, the preferred hook can be reoriented.

Airguns are devices for applying a controlled stream of high-pressure air to an industrial fixture or another surface, typically for purposes of removing debris or other cleaning. As such, airguns are part of a system comprising an air compressor or other source of pressurized air, a length of flexible hose connecting the compressor to the airgun, and the airgun itself. The airgun typically includes a handle, a trigger for controlling the air flow, an extension tube (a.k.a. barrel) for directing the flow, and a nozzle for shaping the discharged flow.
Spray guns, water guns, and oil guns work on similar principles, since all include a fluid flow control device that works off a pressurized source. Such "guns" usually include a mechanism for controllably siphoning and metering a stream of liquid into controlled air flow, for purposes of, e.g., painting or cleaning.
Airguns are most frequently used in industrial settings. For hanging or other storage near machine tools or other workstations, airguns have included a hanger or hook built in as part of the airgun body, i.e., the hook is integral to the body casting. However, because the hook is part of the airgun body, it is immobile, and its position cannot be changed or adjusted by end users. Airguns are manufactured in a wide variety of sizes, shapes, and lengths. When attached to the flexible hose, the center of gravity of the unit may be quite different than the airgun by itself. Thus, airguns can become quite awkward to hang or store in a manner which lends itself to easy operator access and safety, i.e., the easier an airgun is to hang the more likely a user will store it safely. Moreover, existing built-in hooks (e.g., eyelets) tend to be small, and oftentimes cannot accommodate anything larger than a diameter of ⅜″.
In addition to a lack of operational flexibility, built-in hooks often break off during use. This is because built-in hooks are typically made out of the same material as the body casting, namely, die cast aluminum or zinc. Metal is fine for airgun bodies, but is brittle and easily broken in the context of less substantial features such as hooks or hangers. Moreover, because broken aluminum is difficult and impractical to reattach to itself, the broken hooks are virtually impossible to reattach via an adhesive or the like. Also, because they are part of the cast airgun body, they cannot be replaced outright.
Accordingly, a primary object of the present invention is to provide a hook or hanger for airguns that has much greater operational flexibility, that resists breaking, and that can be easily replaced.

Versatile hook for hanging and storing airguns


The present invention controls the concentrations of oxygen and carbonate gases in a hydroponic solution in a growing pool, by independently connecting online to a growing pool a hydroponic-solution feeder in the structure such that a plurality of semipermeable-membrane tubes to circulate liquid fertilizer (or water) is placed and arranged in a tank to circulate water (or liquid fertilizer), and a controller of dissolved gas concentration in the structure such that a hydroponic-solution conduit and a gas conduit are formed separately by arranging in the tank a separating membrane to pass only gas and prevent the permeation of liquid, and circulating oxygen and/or carbonate gas in the gas conduit of the controller of dissolved gas concentration, along with the circulation of the hydroponic solution in the growing pool through the hydroponic-solution conduit while appropriately controlling the concentration of liquid fertilizer in the hydroponic solution by means of the hydroponic-solution feeder, whereby the dissolved gas in the hydroponic solution is substituted with oxygen and/or carbonate gas.

The present invention relates to a hydroponic growing system.
Bubbling systems have been employed in conventional hydroponic growing systems so as to feed oxygen into the hydroponic solution in the growing pools thereof, which is extremely inefficient and is disadvantageous with respect to the maintenance and control of, e.g., the concentration of liquid fertilizer, in the hydroponic solution.
There are additional disadvantages such that it is impossible to suppress or promote the growth in horticulture on an as needed basis, and that water and liquid fertilizer in large quantities are required in order to prevent the decomposition of hydroponic solution and the development of rotten roots.


The object of the present invention is to provide a time division multiple access radio data communication method wherein a radio time slot can be utilized effectively. In order to carry out data communication between data terminal equipment 1a connected to base station equipment 1 and a plurality of predetermined data terminal equipment 10a, 11a, 12a connected to those out station equipment 10, 11, 12 which face base station equipment 1, common radio time slot TS0 is allocated fixedly, and the plurality of predetermined data terminal equipment 10a, 11a, 12a send out request to send signals a0, a1, a2 at timings which do not overlap with each other. Then, out station equipment 10, 11, 12 which receive request to send signals a0, a1, a2 sent out from data terminal equipment 10a, 11a, 12a send back, when they are ready to send out data signals to base station equipment 1 using common radio time slot TS0 allocated thereto, clear to send signals b0, b1, b2 to data terminal equipment 10a, 11a, 12a which have sent out request to send signals a0, a1, a2, whereafter data terminal equipment 10a, 11a, 12a which receive clear to send signals b0, b1, b2 sent back from out station equipment 10, 11, 12 send out data signals to out station equipment 10, 11, 12.

1. Field of the Invention
The present invention relates to a time division multiple access radio data communication method, and more particularly to a time division multiple access radio data communication method wherein radio communication channels are allocated fixedly to carry out multiple access data communication.
2. Description of the Related Art
Generally in a radio system in which multiple access communication is carried out, 1:N time division multiple communication is carried out between a single base station equipment and a plurality of out station equipment which face the base station equipment. In this instance, particularly where the system is of the type in which both telephone communication and data communication are involved, in the telephone communication, channel allocation control is carried out by a demand assign method wherein, only when a call is generated in the base station equipment or one of the out station equipment, a radio communication channel is allocated between the base station equipment and the out station equipment. On the other hand, in the data communication, channel allocation control is carried out by a pre-assignment method wherein a radio communication channel by which data communication is to be carried out is allocated fixedly in advance between a data terminal equipment connected to the base station equipment and another data terminal equipment connected to each out station equipment facing the base station equipment.
FIG. 1 is a view illustrating a conventional time division multiple access radio data communication method, and FIG. 1A is a block diagram showing a conventional example of a time division multiple access radio data communication system and FIG. 1B is a diagrammatic view illustrating a state of radio time slots of the conventional time division multiple access radio data communication system.
The conventional time division multiple access radio data communication method shown in FIG. 1A includes base station equipment 1, a plurality of data terminal equipment 1a, 1b and 1c connected to base station equipment 1, a plurality of out station equipment 10, 11 and 12 which face base station equipment 1 with radio, and data terminal equipment 10a, 11a and 12a connected to out station equipment 10, 11 and 12, respectively. In the downward from the base station equipment to the out station equipment, data communication is carried out by the TDM method, and in the upward from the out station equipment to the base station equipment, data communication is carried out by the TDMA method. Here, operation when data terminal equipment 1a and data terminal equipment 10a, data terminal equipment 1b and data terminal equipment 11a, and data terminal equipment 1c and data terminal equipment 12a carry out data communication in respective facing relationships between each other is described.
First, for the individual facing data terminal equipment, radio time slots to be used as radio communication channels are allocated fixedly in advance. That is, radio time slot TS0 is allocated fixedly to data terminal equipment 1a and data terminal equipment 10a, radio time slot TS1 is allocated fixedly to data terminal equipment 1b and data terminal equipment 11a, and radio time slot TS2 is allocated fixedly to data terminal equipment 1c and data terminal equipment 12a. Since radio time slots TS0, TS1 and TS2 are allocated at different positions which do not overlap with each other on a time basis as shown in FIG. 1B, data signals transmitted using those time slots do not interfere with each other at all. If a call is generated in any data terminal equipment in the system, then since different radio time slots are allocated to the different data terminal equipment, data communication can be carried out between the two facing data terminal equipment without fail.
In data transmission in the downward, data signals sent out from data terminal equipment 1a, data terminal equipment 1b and data terminal equipment 1c are inputted to base station equipment 1, by which they are multiplexed. Thereafter, the multiplexed data signals are transmitted to out station equipment 10, out station equipment 11 and out station equipment 12 using the TDM method. That is, the data signal from data terminal equipment 1a is multiplexed for radio time slot TS0, the data signal from data terminal equipment 1b is multiplexed for radio time slot TS1 and the data signal from data terminal equipment 1c is multiplexed for radio time slot TS2, and the thus multiplexed data signals are sent out to the respective individual out station equipment. It is to be noted that quite the same data signal is sent out from the base station equipment to the individual out station equipment. In each of the out station equipment, only a data signal addressed to the out station equipment itself is selectively demultiplexed and taken out, and the data signal is sent out to a data terminal equipment connected to the out station equipment. That is, the data signal multiplexed for radio time slot TS0 is demultiplexed by out station equipment 10 and sent out to data terminal equipment 10a, the data signal multiplexed for radio time slot TS1 is demultiplexed by out station equipment 11 and sent out to data terminal equipment 11a, and the data signal multiplexed for radio time slot TS2 is demultiplexed by out station equipment 12 and sent out to data terminal equipment 12a.
In data transmission in the upward, data signals from the data terminal equipment connected to the out station equipment are multiplexed for the radio time slots individually allocated thereto by the out station equipment, and sent out as burst signals to the base station equipment using the TDMA method. That is, the data signal from data terminal equipment 10a is inputted to out station equipment 10 and multiplexed for radio time slot TS0 and is sent as a burst signal to the base station equipment 1. Similarly, the data signal from data terminal equipment 11a is inputted to out station equipment 11 and multiplexed for radio time slot TS1 whereas the data signal from data terminal equipment 12a is inputted to out station equipment 12 and multiplexed for radio time slot TS2 and respective signals are sent as burst signals to base station equipment 1. In the base station equipment, the data signals from the individual out station equipment are individually demultiplexed and taken out, and the data signals are sent out to the individually corresponding data terminal equipment connected thereto. That is, the data signal multiplexed for radio time slot TS0 is sent out to data terminal equipment 1a, the data signal multiplexed for radio time slot TS1 is sent out to data terminal equipment 1b, and the data signal multiplexed for radio time slot TS2 is sent out to data terminal equipment 1c.
The operation described above is carried out, when data signals are sent out from the data terminal equipment, irrespective of whether or not such control signals as a request to send signal or a clear to send signal accompany them.
It is to be noted that, for convenience of description, in FIG. 1A, the number of out station equipment is 3 and the number of data terminal equipment connected to each out station equipment is 1, and those elements such as circuits and signals lines which are not particularly significant are omitted.
In the conventional time division multiple access radio data communication method described above, radio time slots to be used as radio communication channels are allocated fixedly in advance and used between individually facing data terminal equipment. Therefore, the conventional time division multiple access radio data communication method has a problem in that, where a plurality of data terminal equipment are included in a radio communication system, even when data communication is not actually being carried out with those data terminal equipment, a plurality of radio time slots are occupied, and particularly where the amount of data communication is low or the data transmission amount is small or else data communication is carried out only periodically or intermittently, the efficiencies of utilization of the radio time slots is low.
Further, the conventional time division multiple access radio data communication method has another problem in that, where the base station equipment requires a number of data terminal equipment and interface units therefore equal to the number of data terminal equipment connected to the individual out station equipment, and the structure of the system will become large.

Time division multiple access radio data communication method


A high-power BGA includes a printed circuit board with a through hole, connection pads formed on the bottom of the printed circuit board, matrix solder balls surrounding the through hole and adjacent to the connection pads, a heat spreader on the top surface of the printed circuit board that includes an insulating layer of a high thermal conductivity, a semiconductor chip mounted within the through hole on the bottom surface of the heat spreader that includes a number of contact pads for bonding with the connection pads using gold wires, and a passive film filling the through hole and around the semiconductor chip. By interposing a ceramic insulating layer between the semiconductor chip and the heat spreader, charge generation between the semiconductor chip and the heat spreader is sharply reduced, and defects such as ESD (electrostatic discharge) is reduced during testing and mounting of the package.

1. Field of the Invention
This disclosure relates to semiconductor packages and, more particularly, to a high-power ball grid array (BGA) package having a heat spreader, a method for manufacturing the heat spreader, a BGA printed circuit board (PCB) to which the method is applied, and a method for manufacturing the BGA PCB.
2. Description of the Related Art
As devices become highly integrated, the number of connection pads in a semiconductor device, such as a semiconductor memory device, increases. Thus, the number of lead lines in a package included in a PCB also increases. As the number of lead lines increases, a lead frame using conventional package technology cannot be applied to a highly-integrated semiconductor chip having over 400 lead lines. Accordingly, a BGA package has been introduced in which package output terminals are arranged on a large bottom board of the package.
The BGA package includes a square-shaped main body, a semiconductor chip which is mounted on the top surface of the main body, and matrix solder balls at the bottom surface of the main body that contact the printed circuit board and thus can be arranged and mounted on a pad of the printed circuit board by using a reflow process.
Such a BGA package requires a heat spreader on the surface of the semiconductor chip so as to emit heat to the outside the package when a considerable amount of heat is generated during the operation of the semiconductor chip. However, since a gold wire is formed upwardly to connect the semiconductor chip with the pad of the main body of the package, it is difficult to mount the heat spreader on the BGA package and so such BGA package is not appropriate for a high-power BGA package.
Referring to FIG. 12, illustrated is a conventional, high-power BGA package structured to overcome the heat emitting problem of the conventional BGA package described above. The conventional high-power BGA package includes a package printed circuit board 1200, a through portion 1200a at the center of the package circuit board 1200, pads for bonding (not shown) at the bottom surface of the printed circuit board 1200, a heat spreader 1110 that is connected to the top surface of a metal layer 1120, a supporting main body 1130 that is connected to the bottom surface of the heat spreader 1110, and a semiconductor chip 1101 that is mounted under the supporting main body 1130 within the through portion 1200a, includes a plurality of metal pads 1101a on its bottom surface, and is connected to pads for the bonding (not shown) and gold wires 1101b. This conventional high-power BGA package is capable of easily emitting heat away and cooling the semiconductor chip through the heat spreader 1110 that is stably mounted on the surface of the BGA package, even though the heat is generated in the semiconductor device.
The heat spreader 1110 of the conventional high-power BGA package, however, is composed of conductive copper and surface-processed nickel, a fact that results in a constant voltage between the semiconductor chip 1101 and the heat spreader 1110 during the operation of the semiconductor chip 1101 and can cause damage to the semiconductor chip 1101 in many cases. Consequently, the semiconductor device yield of the conventional BGA package decreases, and the reliability of the semiconductor device may not be ensured when mounting the semiconductor chip on the printed circuit board.
Embodiments of the invention address these and other limitations of conventional devices.

High-power ball grid array package, heat spreader used in the BGA package and method for manufacturing the same


An apparatus is described which includes memory areas for storing an image and trigger fields for the image, and a display which indicates a cursor in one of two configurations. Circuitry is provided for moving the cursor and enabling it to implement a select operation for a particular subroutine. The apparatus employs a method which enables the trigger fields to be invisible, which method comprises: displaying the image without trigger fields; and altering the cursor on the display from one configuration to another upon the cursor being moved into an invisible trigger field to thereby indicate to the user the presence of the trigger field.

It is known that during run-time presentations of display images in a data processing system (e.g. a personal computer), an image zone ("trigger field") can be selected by a user moving a cursor to the field, under control of a mouse or keyboard keys Such trigger fields may correspond to displayed icons, portions of an image, areas around significant words, etc. Depending upon the user's selection of a trigger field, different program paths can be implemented, subroutines activated, or other processing functions controlled. For example, an icon of of a cat may lead to one story path, while an icon of a dog may lead to a different path. To enable this selectivity, the image must have the trigger field identified in advance so that the placement of a cursor therein enables the selection of the particular story path.
Characteristically, trigger fields are marked on the display so that the user knows where to move the cursor to make the selection. Of necessity, the trigger fields are kept relatively small so that the field demarcations do not occupy significant space on the display. This then requires the user to move the cursor, with some precision, to assure that the cursor overlaps the trigger field Cursor "overshoots" and "undershoots" are common and require time consuming adjustment by the user to assure proper cursor/trigger field alignment
Thus, for optimum user interaction, it is desirable to make trigger fields as large as possible, but then the image becomes cluttered This results in a larger problem when it is desired to have many trigger fields overlapping various portions of an image. For instance, if an image of an airplane is displayed, and it is desired to enable the user to select any of the main aircraft subassemblies, e.g. wings, tail, fuselage etc., and then display a blow-up image of the selected portion, the placement of visible trigger fields can significantly clutter the image and may obscure structural features.
Accordingly, it is an object of this invention to provide a display with trigger fields which facilitate user selection.
It is another object of this invention to provide a display with trigger fields which do not clutter the image.

International Business Machines Corporation


A liquid crystal compound, preferably a molten iodine salt, an electrolyte comprising the same, and a photo-electrochemical cell are disclosed. The electrolyte is little volatile and excellent in charge transporting performance and provides a photo-electrochemical cell which exhibits high photoelectric conversion efficiency and excellent durability.

This invention relates to a novel liquid crystal compound which is specially useful as an electrolyte, a mixture or composition containing the compound, an electrolyte comprising a liquid crystal compound including the novel compound, and an electrochemical cell using the electrolyte, particularly a photo-electrochemical cell.
The electrolyte used in an electrochemical cell, such as a lithium ion secondary battery or a solar cell having a dye-sensitized semiconductor layer, is a medium which contains ions meeting the purpose and functions as an ion conductor transporting the ions between electrodes. A solution type electrolyte (i.e., electrolytic solution) has been of general use because of its high ion conductivity but is disadvantageous in that the solvent tends to evaporate or the solution tends to leak while used in a battery, causing reduction of battery life. Further, a metallic container should be used to seal in the electrolytic solution, which increases the weight of the battery and narrows the freedom of design.
In order to overcome the disadvantages of a solution type electrolyte, various types of electrolytes have recently been proposed. Although a gel electrolyte comprising a polymer matrix impregnated with an electrolytic solution, not being so inferior in ion conductivity, offers a level of battery performance equal to that of a solution type electrolyte, it cannot completely avoid evaporation of the solvent. A polymer electrolyte comprising a polymer, such as polyethylene oxide, having a salt dissolved therein is expected to settle the problems associated with a solution type electrolyte but has not attained sufficient ion conductivity. A molten salt, which is liquid at room temperature, such as an imidazolium or pyridinium salt having BF4xe2x88x92, (CF3SO2)2Nxe2x88x92, etc. as a counter anion, has been suggested as an electrolyte of lithium ion batteries. However, mechanical strength and ion conductivity of an electrolyte conflict with each other. When the mechanical strength of the molten salt electrolyte is enhanced by increasing the viscosity of the molten salt itself or by incorporating a polymer, a reduction in ion conductivity results. Further, these state-of-the-art electrolytes show large temperature dependence of ion conductivity, and, in particular, their ion conductivity is insufficient at low temperature.
On the other hand, study of photovoltaic power generation (i.e., solar electricity generation) consisting in conversion of light energy to electrical energy has been directed chiefly to development of monocrystalline silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells, and compound solar cells using cadmium telluride, copper indium selenide, etc., and some of them have been put to practical use. It is required for spread of solar cells to overcome such difficulties as a high production cost, a short supply of raw materials, and a long energy payback time. Although many solar cells using organic materials have been proposed aiming at an increase of working area and a reduction of cost, they have a low conversion efficiency and poor durability.
Under these circumstances, Nature, vol. 353, pp. 737-740 (1991) and U.S. Pat. No. 4,927,721 disclosed a photoelectric conversion device using a dye-sensitized oxide semiconductor (hereinafter, called a dye-sensitized photoelectric conversion device) and a photo-electrochemical cell comprising the device. The disclosed cell comprises a photoelectric conversion device functioning as a work electrode (negative electrode), a charge transporting layer, and a counter electrode (positive electrode). The photoelectric conversion device comprises an electrically conductive substrate and a photosensitive layer containing a semiconductor having a dye adsorbed on the surface thereof. The charge transporting layer comprises a redox system and serves for charge transport between the negative electrode and the positive electrode. The photo-electrochemical cell proposed in the above U.S. Patent is of wet type using, as a charge transporting layer, an aqueous electrolytic solution containing such a salt as potassium iodide. This system is promising in that a relatively high energy conversion efficiency (i.e., photoelectric conversion efficiency) can be reached for its low price. The outstanding problem of conventional dye-sensitized photoelectric conversion devices is that the cell will be short of the electrolytic solution due to evaporation in long-term use only to have a seriously deteriorated photoelectric conversion efficiency or fail to function as a cell.
To solve this problem, WO95/18456 teaches use of an imidazolium salt that is a low-melting compound as an electrolyte so as to prevent a shortage of an electrolytic solution. According to this method, water or an organic solvent that has been used as a solvent for an electrolyte is not necessary at all or used in a reduced amount so that improvement in durability can result. However, the durability is still insufficient and, besides, an increase in concentration of the imidazolium salt is accompanied by a reduction of photoelectric conversion efficiency. Use of a triazolium salt as an electrolyte has also been proposed, which has the same problems as the imidazolium salt.
An object of the present invention is to provide a novel liquid crystal compound and a mixture or composition containing the same which are specially useful as a material of an electrolyte for an electrochemical cell.
Another object of the present invention is to provide an electrolyte having high electrical conductivity and durability which is specially suited for use in a photo-electrochemical cell.
Still another object of the present invention is to provide an electrochemical cell having excellent durability, particularly a photo-electrochemical cell excellent in photoelectric conversion efficiency and durability.
The above objects of the present invention are accomplished by:
(1) A liquid crystal compound represented by formula (I-1) or (I-2):
xe2x80x83wherein Q111 represents a divalent linking group with the proviso that Q111 does not represent a polymethylene group nor a phenylenebis(poly)methylene group without containing a hetero atom; X111xe2x88x92represents an anion; R141, R151, R161, and R171 each represent a hydrogen atom or a substituent; R131 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group; Y111 represents a divalent 4-, 5-, 6- or 7-membered ring or a divalent condensed ring composed of 4-, 5-, 6- or 7-membered rings; Q121 and Q131 each represent a divalent linking group or a single bond; n represents 1, 2 or 3; when n is 2 or 3, the plural Y111""s Q121""s, and Q131""s may be the same or different.
(2) A liquid crystal mixture comprising at least two liquid crystal compounds represented by formula (I-1) or (I-2).
(3) A liquid crystal composition comprising at least one liquid crystal compound represented by formula (I-1) or (I-2) and at least one compound selected from an alkali metal salt and an alkaline earth metal salt.
(4) An electrolyte containing at least one liquid crystal compound represented by formula (IA):
xe2x80x83wherein R111 represents a substituted or unsubstituted alkyl or alkenyl group which is bonded to the nitrogen atom either directly or via a divalent linking group; Z111 represents an atomic group necessary to form a 5- or 6-membered aromatic heterocyclic cation together with the nitrogen atom; R121 represents a substituent serving to exhibit liquid crystal properties which contains at least one divalent cyclic linking group and at least one substituted or unsubstituted alkyl or alkenyl group; and X111xe2x88x92represents an anion, the compound represented by formula (IA) being preferably represented by formula (I-1) or (I-2).
(5) An electrochemical cell having the above-described electrolyte, particularly a photo-electrochemical cell comprising a semiconductor responsive to a radiant ray and a charge transporting layer containing the above-described electrolyte.
According to the present invention, an electrolyte which is substantially nonvolatile and excellent in charge transporting performance can be provided. The electrolyte of the present invention provides a photo-electrochemical cell which exhibits excellent photoelectric conversion characteristics and undergoes little deterioration in performance with time.

Liquid crystal compound, liquid crystal mixture or composition, electrolyte comprising the same, electrochemical cell and photo-electrochemical cell containing the electrolyte