The present invention provides compositions comprising thermostable DNA polymerases derived from hyperthermophilic eubacteria. In particular, the present invention comprises thermostable DNA polymerases from the hyperthermophilic eubacterial species Thermoactinomyces vulgaris. The present invention also provides methods for utilizing naturally-occurring and non-naturally-occurring forms of T. vulgaris DNA polymerase in sequencing, reverse transcription, and amplification reactions.

Thermophilic bacteria are organisms which are capable of growth at elevated temperatures. Unlike the mesophiles, which grow best at temperatures in the range of 25–40° C., or psychrophiles, which grow best at temperatures in the range of 15–20° C., thermophiles grow best at temperatures greater than 50° C. Indeed, some thermophiles grow best at 65–75° C., and some of the hyperthermophiles grow at temperatures up to 130° C. (e.g., J. G. Black, Microbiology Principles and Applications, 2d edition, Prentice Hall, New Jersey, 1993, p. 145–146).
The thermophilic bacteria encompass a wide variety of genera and species. There are thermophilic representatives included within the phototrophic bacteria (i.e., the purple bacteria, green bacteria, and cyanobacteria), eubacteria (i.e., Bacillus, Clostridium, Thiobacillus, Desulfotomaculum, Thermus, lactic acid bacteria, actinomycetes, spirochetes, and numerous other genera), and the archaebacteria (i.e., Pyrococcus, Thermococcus, Thermoplasma, Thermotoga, Sulfolobus, and the methanogens). There are aerobic, as well as anaerobic thermophilic organisms. Thus, the environments in which thermophiles may be isolated vary greatly, although all of these organisms are isolated from areas associated with high temperatures. Natural geothermal habitats have a worldwide distribution and are primarily associated with tectonically active zones where major movements of the earth's crust occur. Thermophilic bacteria have been isolated from all of the various geothermal habitats, including boiling springs with neutral pH ranges, sulfur-rich acidic springs, and deep-sea vents. In general, the organisms are optimally adapted to the temperatures at which they are living in these geothermal habitats (T. D. Brock, "Introduction: An overview of the thermophiles," in T. D. Brock (ed.), Thermophiles: General, Molecular and Applied Microbiology, John Wiley & Sons, New York, 1986, pp. 1–16). Basic, as well as applied research on thermophiles has provided some insight into the physiology of these organisms, as well as use of these organisms in industry and biotechnology.
I. Uses For Thermophilic Enzymes
Advances in molecular biology and industrial processes have led to increased interest in thermophilic organisms. Of particular interest has been the development of thermophilic enzymes for use in industries such as the detergent, flavor-enhancing, and starch industries. Indeed, the cost savings associated with longer storage stability and higher activity at higher temperatures of thermophilic enzymes, as compared to mesophilic enzymes, provide good reason to select and develop thermophilic enzymes for industrial and biotechnology applications. Thus, there has been much research conducted to characterize enzymes from thermophilic organisms. However, some thermophilic enzymes have less activity than their mesophilic counterparts under similar conditions at the elevated temperatures used in industry (typically temperatures in the range of 50–100° C.) (T. K. Ng and William R. Kenealy, "Industrial Applications of Thermostable Enzymes," in T. D. Brock (ed.), Thermophiles: General, Molecular, and Applied Microbiology, 1986, John Wiley & Sons, New York, pp. 197–215). Thus, the choice of a thermostable enzyme over a mesophilic one may not be as beneficial as originally assumed. However, much research remains to be done to characterize and compare thermophilic enzymes of importance (e.g., polymerases, ligases, kinases, topoisomerases, restriction endonucleases, etc.) in areas such as molecular biology.
II. Thermophilic DNA Polymerases
Extensive research has been conducted on isolation of DNA polymerases from mesophilic organisms such as E. coli. (e.g., Bessman et al., J. Biol. Chem. 223:171, 1957; Buttin and Kornberg, J. Biol. Chem. 241:5419, 1966; and Joyce and Steitz, Trends Biochem. Sci., 12:288–292, 1987). Other mesophilic polymerases have also been studied, such as those of Bacillus licheniformis (Stenesh and McGowan, Biochim. Biophys. Acta 475:32–44, 1977; Stenesh and Roe, Biochim. Biophys. Acta 272:156–166, 1972); Bacillus subtilis (Low et al., J. Biol. Chem., 251:1311, 1976; and Ott et al., J. Bacteriol., 165:951, 1986); Salmonella typhimurium (Harwood et al., J. Biol. Chem., 245:5614, 1970; Hamilton and Grossman, Biochem., 13:1885, 1974); Streptococcus pneumoniae (Lopez et al., J. Biol. Chem., 264:4255, 1989); and Micrococcus luteus (Engler and Bessman, Cold Spring Harbor Symp., 43:929, 1979), to name but a few.
Somewhat less investigation has been performed on the isolation and purification of DNA polymerases from thermophilic organisms. However, native (i.e., non-recombinant) and/or recombinant thermostable DNA polymerases have been purified from various organisms, as shown in Table 1 below.
TABLE 1Polymerase Isolation From Thermophilic OrganismsOrganismCitationThermus aquaticusKaledin et al., Biochem., 45:494–501(1980); Biokhimiya 45:644–651 (1980).Chien et al., J. Bacteriol., 127:1550 (1976).University of Cincinnati Master's thesis byA. Chien, "Purification andCharacterization of DNA Polymerase fromThermus aquaticus," (1976).University of Cincinnati Master's thesisby D. B. Edgar, "DNA Polymerase From anExtreme Thermophile: Thermus aquaticus,"(1974).U.S. Pat. No. 4,889,818*U.S. Pat. No. 5,352,600*U.S. Pat. No. 5,079,352*European Patent Pub. No. 258,017*PCT Pub. No. WO 94/26766*PCT Pub. No. WO 92/06188*PCT Pub. No. WO 89/06691*Thermatoga maritimaPCT Pub. No. WO 92/03556*Thermatoga neapolitanaU.S. Pat. No. 5,912,155*U.S. Pat. No. 5,939,301*U.S. Pat. No. 6,001,645*Thermatoga strainSimpson et al., Biochem. Cell Biol.,FjSS3-B.168:1292–1296 (1990).Thermosipho africanusPCT Pub. No. 92/06200*U.S. Pat. No. 5,968,799*Thermus thermophilusMyers and Gelfand, Biochem., 30:7661(1991).PCT Pub. No. WO 91/09950*PCT Pub. No. WO 91/09944*Bechtereva et al., Nucleic Acids Res.,17:10507 (1989).Glukhov et al., Mol. Cell. Probes4:435–443 (1990).Carballeira et al., BioTech.,9:276–281 (1990).Ruttiman et al., Eur. J. Biochem.,149:41–46 (1985).Oshima et al., J. Biochem.,75:179–183 (1974).Sakaguchi and Yajima, Fed. Proc.,33:1492 (1974) (abstract).Thermus flavusKaledin et al., Biochem.,46:1247–1254 (1981); Biokhimiya 46:1576–1584 (1981).PCT Pub. No. WO 94/26766*Thermus ruberKaledin et al., Biochem.,47:1515–1521 (1982);Biokhimiya 47:1785–1791 (1982).Thermoplasma acidophilumHamal et al., Eur. J. Biochem.,190:517–521 (1990).Forterre et al., Can. J. Microbiol.,35:228–233 (1989).Sulfolobus acidocaladariusSalhi et al., J. Mol. Biol.,209:635–641 (1989).Salhi et al., Biochem. Biophys. Res. Comm.,167:1341–1347 (1990).Rella et al., Ital. J. Biochem.,39:83–99 (1990).Forterre et al., Can. J. Microbiol.,35:228–233 (1989).Rossi et al., System. Appl. Microbiol.,7:337–341 (1986).Klimczak et al., Nucleic Acids Res.,13:5269–5282 (1985).Elie et al., Biochim. Biophys. Acta951:261–267 (1988).Bacillus caldotenaxJ. Biochem.,113:401–410 (1993).Bacillus stearothermophilusSelimann et al., J. Bacteriol.,174:4350–4355 (1992).Stenesh and McGowan, Biochim.Biophys. Acta 475:32–44 (1977).Stenesh and Roe, Biochim.Biophys. Acta 272:156–166 (1972).Kaboev et al., J. Bacteriol.,145:21–26 (1981).MethanobacteriumKlimczak et al., Biochem.,thermoautotropicum25:4850–4855 (1986).Thermococcus litoralisKong et al., J. Biol. Chem. 268:1965 (1993)U.S. Pat. No. 5,210,036*U.S. Pat. No. 5,322,785*Anaerocellum thermophilusAnkenbauer et al., WO 98/14588*Pyrococcus sp. KOD1U.S. Pat. No. 6,008,025*Pyrococcus furiosusLundberg et al., Gene 108:1 (1991)PCT Pub. WO 92/09689U.S. Pat. No. 5,948,663U.S. Pat. No. 5,866,395*Herein incorporated by reference.
In addition to native forms, modified forms of thermostable DNA polymerases having reduced or absent 5′ to 3′ exonuclease activity have been expressed and purified from T. aquaticus, T. maritima. Thermus species sps17, Thermus species Z05, T. thermophilus, Bacillus stearothermophilus (U.S. Pat. Nos. 5,747,298, 5,834,253, 5,874,282, and 5,830,714) and T. africanus (WO 92/06200).
III. Uses For Thermophilic DNA Polymerases
One application for thermostable DNA polymerases is the polymerase chain reaction (PCR). The PCR process is described in U.S. Pat. Nos. 4,683,195 and 4,683,202, the disclosures of which are incorporated herein by reference. Primers, template, nucleoside triphosphates, appropriate buffer and reaction conditions, and polymerase are used in the PCR process, which involves multiple cycles of denaturation of target DNA, hybridization of primers to the target DNA and synthesis of complementary strands. The extension product of each primer becomes a template in the subsequent cycle for production of the desired nucleic acid sequence. Use of a thermostable DNA polymerase enzyme in PCR allows repetitive heating/cooling cycles without the requirement of fresh DNA polymerase enzyme at each cooling step because heat will not destroy the polymerase activity. This represents a major advantage over the use of mesophilic DNA polymerase enzymes such as Klenow in PCR, as fresh mesophilic polymerase must be added to each individual reaction tube at every cycle. The use of Taq in PCR is described in U.S. Pat. No. 4,965,188, EP Publ. No. 258,017, and PCT Publ. No. 89/06691, herein incorporated by reference.
In addition to PCR, thermostable DNA polymerases are widely used in other molecular biology techniques including recombinant DNA methods. For example, various forms of Taq have been used in a combination method which utilizes reverse transcription and PCR (e.g., U.S. Pat. No. 5,322,770, herein incorporated by reference). DNA sequencing methods utilizing Taq DNA polymerase have also been described (e.g., U.S. Pat. No. 5,075,216, herein incorporated by reference).
However, some thermostable DNA polymerases have certain characteristics (e.g., 5′ to 3′ exonuclease activity) which are undesirable in PCR and other applications. In some cases, when thermostable DNA polymerases that have 5′ to 3′ exonuclease activity (e.g., Taq, Tma, Tsps17, TZ05, Tth and Taf) are used in the PCR process and other methods, a variety of undesirable results have been observed, including a limitation of the amount of PCR product produced, an impaired ability to generate long PCR products or to amplify regions containing significant secondary structure, the production of shadow bands or the attenuation in signal strength of desired termination bands during DNA sequencing, the degradation of the 5′ end of oligonucleotide primers in the context of double-stranded primer-template complex, nick-translation synthesis during oligonucleotide-directed mutagenesis and the degradation of the RNA component of RNA:DNA hybrids. When utilized in a PCR process with double-stranded primer-template complex, the 5′ to 3′ exonuclease activity of a DNA polymerase may result in degradation of oligonucleotide primers from their 5′ end. This activity is undesirable not only in PCR, but also in second-strand cDNA synthesis and sequencing processes.
When choosing to produce and use an enzyme for sequencing, various factors are considered. For example, large quantities of the enzyme should be easy to prepare; the enzyme should be stable upon storage for considerable time periods; the enzyme should accept all deoxy and dideoxy nucleotides and analogues as substrates with equal affinities and high fidelity; the polymerase activity should be highly processive over nucleotide extensions to 1 kb and beyond, even through regions of secondary structure within the template; the activity should remain high, even in suboptimal conditions; and the enzyme should be inexpensive (A. T. Bankier, "Dideoxy sequencing reactions using Klenow fragment DNA polymerase 1," in H. and A. Griffin (eds.), Methods in Molecular Biology: DNA Sequencing Protocols, Humana Press, Totowa, N.J., 1993, pp. 83–90). Furthermore, the enzyme should be able to function at elevated temperatures (e.g., greater than about 70° C.), so that non-specific priming reactions are minimized. However, there are no native enzymes which fully meet all of these criteria. Thus, mutant forms of enzymes have been produced in order to address some of these needs.
For example, mutant forms of thermostable DNA polymerases that exhibit reduced or absent 5′ to 3′ exonuclease activity have been generated. The Stoffel fragment of Taq DNA polymerase lacks 5′ to 3′ exonuclease activity due to genetic manipulations that resulted in the production of a truncated protein lacking the N-terminal 289 amino acids (e.g., Lawyer et al., J. Biol. Chem., 264:6427–6437, 1989; and Lawyer et al., PCR Meth. Appi., 2:275–287, 1993). Analogous mutant polymerases have been generated from various polymerases, including Tma, Tsps17, TZ05, Tth and Taf. While the generation of thermostable polymerases lacking 5′ to 3′ exonuclease activity provides improved enzymes for certain applications, some of these mutant polymerases still have undesirable characteristics, including the presence of 3′ to 5′ exonuclease activity.
The 3′ to 5′ exonuclease activity is commonly referred to as proof-reading activity, it removes bases that are mismatched at the 3′ end of a primer in a primer-template duplex. While the presence of 3′ to 5′ exonuclease activity may be advantageous, as it leads to an increase in the fidelity of replication of nucleic acid strands, it also has some undesirable characteristics. The 3′ to 5′ exonuclease activity found in thermostable DNA polymerases such as Tma (including mutant forms of Tma that lack 5′ to 3′ exonuclease activity) also degrades single-stranded DNA such as primers used in PCR, single-stranded templates and single-stranded PCR products. The integrity of the 3′ end of an oligonucleotide primer used in a primer extension process (e.g., PCR, Sanger sequencing methods, etc.) is critical, as it is from this terminus that extension of the nascent strand begins. Degradation of the 3′ end of a primer results in loss of specificity in the priming reaction (i.e., the shorter the primer, the more likely that non-specific priming will occur).
Degradation of an oligonucleotide primer by a 3′ to 5′ exonuclease can be prevented by use of nucleotides modified at their 3′ terminus. For example, use of dideoxynucleotides or deoxynucleotides having a phosphorothiolate linkage between nucleotides at the 3′ terminus of an oligonucleotide can prevent degradation by 3′ to 5′ exonucleases. However, the need to use modified nucleotides to prevent degradation of oligonucleotides by a 3′ to 5′ exonuclease increases the time and cost required to prepare oligonucleotide primers.
A few examples of thermostable polymerases lacking both 5′ to 3′ exonuclease and 3′ to 5′ exonuclease are known. As discussed above, the Stoffel fragment of Taq DNA polymerase lacks the 5′ to 3′ exonuclease activity due to genetic manipulation and no 3′ to 5′ activity is present, as Taq polymerase is naturally lacking in 3′ to 5′ exonuclease activity. Likewise, Tth polymerase naturally lacks 3′ to 5′ exonuclease activity and deletion nucleotide sequence encoding N-terminal amino acids can be used to remove 5′ to 3′ exonuclease activity.
Despite development of recombinant enzymes such as Stoffel fragment, there remains a need for other thermostable polymerases having improved characteristics for various applications. For example, some thermostable polymerases possess reverse transcriptase activity and they find use in reverse transcription methods since elevated temperatures help the enzyme to proceed through regions of the RNA which at lower temperatures would possess secondary structure. However, reverse transcription by thermostable DNA polymerases is often dependent on manganese. Unfortunately, the presence of manganese ions can cause higher rates of infidelity and damage to polynucleotides. Accordingly, what is needed in the art are improved thermostable DNA polymerases with enhanced properties, such as reverse transcriptase activity in the presence of magnesium.


An apparatus is disclosed for providing more uniform lighter spark wheel actuation. Uniform actuation is facilitated in the apparatus according to the invention by reducing the formation of deep grooves and high ridges in the flint. In one embodiment of the invention, a spark wheel coil formed from wire having at least one substantially flat side is utilized to reduce ridge formation. The spark wheel coil includes pitting in a transversal direction made on the outer surface of the coil. The pitting forms projections which protrude from the core of the coil and which, when contacting a pyrophoric flint while the coil spring is rotated about its axis, produce a tangential cutting across the pyrophoric flint to emit an ignition spark.

1. Technical Field
The present invention relates to a lighter which consumes hydrocarbon fuel such as butane and includes a spark producing means Specifically, the present invention relates to an improved spark producing means for a lighter which is more uniformly operatable.
2. Discussion of the Related Art
A conventional cigarette lighter includes a body containing a fuel reservoir filled with a liquified and pressurized hydrocarbon fuel, a valve actuator lever, a spark wheel, a flint in frictional contact with the spark wheel, and a fuel flow control valve in fluid communication with the fuel reservoir. After the spark wheel is rotated against the flint by digital manipulation to produce sparks, the valve actuator lever is depressed allowing gaseous hydrocarbon fuel to flow out of the reservoir through the flow control valve. The sparks then ignite the released fuel to produce a flame. Such lighters are known in the art and are commercially available.
Specific means for producing ignition sparks when contacting a pyrophoric flint in these lighters are also known in the art. For example, U.S. Pat. No. 4,509,916 to Le Boudec discloses a device for producing an ignition spark when contacting a flint. The device includes a flint cutting member made from helically-coiled wire with a circular cross section which includes saw-teeth projections for contacting and cutting the flint to create sparks. The flint, like the coiled wire, also includes a circular cross section. The device may be configured and adapted for use as a spark wheel in known lighters.
However, these related art spark producing means are disadvantageous in that irregular friction is produced between the flint and the user-rotatable spark wheel. This irregular friction leads to non-uniform rotational force requirements for rotating the spark wheel, and thus may increase the difficulty in producing ignition sparks.
More particularly, when a flint with a circular cross section is utilized in conjunction with a art spark wheel coil fashioned from wire with a circular cross section, the surface of the flint contacting the coil becomes deeply grooved over time so as to match the curved coil surface. The same difficulty can also arise with spark wheel assemblies having a flint cutting member made from a solid cylinder rather than coiled wire. Such solid cylinders are typically cut with a spiral groove on the outer surface to improve the spark creating characteristics of the part. This spiral groove in the cutting member can also result in a deeply grooved flint, such as encountered with the coiled wire cutting members. In addition, the rotation of such cutting members against the flint during use urges the flint to rotate about its central axis.
These two factors, i.e., the deep grooving of the flint surface (and resulting high ridges) and the urged rotation of the flint during use, are disadvantageous in combination as they bring about non-uniform user actuation of the spark wheel. More specifically, the flint, with a highly ridged/deeply grooved striking surface as shown in FIG. 7A, provides a significant non-uniform resistance to rotation of the spark wheel assembly as the cutting member is required to periodically breakdown the high ridges as it is rotated. The nonuniformity of the force required to rotate the spark wheel assembly can be increased further when the flint itself rotates on its axis as a result of the screw thread like action of the cutting member on the flint. Such rotation of the flint is difficult for the user to overcome due to the high ridges on the flint surface which require a relatively high force to break through.
Highly non-uniform resistance is especially disadvantageous in many of the newer child resistant lighters. For example, U.S. Pat. No. 5,483,978 to Doiron discloses a child resistant lighter with a guard which partially covers the spark wheel, thereby increasing the difficulty of rotating the same. This spark wheel cover, when combined with the non-uniform force requirements of the prior art spark producing means can result in non-uniform and unpredictable increases in the difficulty of lighter actuation by intended users.

Reduced resistence device for producing ignition sparks


An organizer case comprising a tray having a bottom wall and a plurality of compartment walls formed unitarily with and upstanding from said bottom wall, at least two of said walls extending in parallel relation and spaced apart a separation distance, said two of said walls having confronting sidewall faces each having a plurality of first joint formers spaced therealong, a first set of insert dividers each dimensioned to extend non-orthogonally between said sidewall faces, a second set of insert dividers each dimensioned to extend orthogonally between said sidewall faces, the dividers of each said set each having opposed side edge flange portions having second joint formers for friction fit engagement with said first joint formers, said side edge flange portions of each of the dividers of said first set being spaced apart a distance at least about 20% greater than said separation distance.

The present invention relates to organizer cases and, more particularly, to cases for organizing small fishing tackle and related items.
Plano Molding Company has long produced a line of small injection molded plastic organizer cases for fishing tackle such as lures, hooks, sinkers and the like. These cases range in size from 8.25 in. (L)×4.25 in. (W)×1.38 in. (H) to 14 in. (L)×9.13 in. (W)×2 in. (H) and have been produced with divider inserts so that the user may tailor individual compartment size to the particular array of items to be stored in the case. To this end, the cases are produced with a number of walls formed unitarily with the case. The walls are provided with a series of joint formers (dovetail grooves or recesses) that are spaced therealong. The inserts have side edge portions with cooperating joint formers (dovetail tenons).
The foregoing Plano cases and competitive cases are designed to permit the user to configure a large number of variously sized (or like sized) compartments of rectangular configuration.
One limitation of cases heretofore offered has been the fact that the insert dividers can be used only to make rectangularly shaped individual compartments. Another limitation has been that very small items such as hooks, monofilament line and the like can migrate between compartments by sliding under or over the insert dividers.
The object of the present invention is to overcome the foregoing limitations inherent in the prior art.


A new wheel lighting device which operates in either an “ON” mode or a “RECHARGE” mode. In the “ON” mode rechargeable batteries mounted on a vehicles wheel supply power to LED's which illuminate a vehicles wheel, and the device is independent of the vehicles electrical system. In the “RECHARGE” mode the device is electrically connected, by means of a retractable connector and insulated conductive ring, to the vehicles fully charged battery, (when the vehicle engine is no longer in motion), and uses that battery to recharge the rechargeable batteries on the wheel. While this is happening the LED's are reverse biased to the current and are off, and a now forward biased diode allows the recharging. A voltage regulator is used to convert the voltage of the vehicles battery to a suitable voltage of the rechargeable batteries. Once the rechargeable batteries are disconnected from the vehicles electrical system, as when the vehicle is started, the device returns to the “ON” mode.

The present invention relates to providing decorative lighting to vehicle wheels. Specifically, the present invention sets forth a new, useful, and practical application of wheel lighting using rechargeable batteries which are automatically recharged using the vehicles existing power supply, and lights which automatically turn on when the vehicle starts, and off when the vehicle is shut off.
Automobile makers offer, more or less, mass-produced generic vehicles because in this way they are able to make, and sell them cheaper. Of course, everyone is different and wants to be unique, so manufacturers profit off this by offering accessories to customize the vehicles to a particular customers preference. One field of these accessories is lighting, and while it is relatively easy to attach a stationary light to the vehicles stationary battery and body, it is quite difficult to attach lights on the rotating and exposed wheels of the vehicle. While several attempts have been made, they all falter in practicality and consumer desirability.
One such example is the solution provided in U.S. Pat. No. 6,601,979 to Byrd who describes attaching insulated conductive bands to the inside of a wheel and allowing current to flow from the vehicles battery to the bands by contact with electrical brushes. This cumulator is the acting means of electrical motors and works well in that application, but on wheels it falls short for several reasons. Number one is the surface speed contact between the brushes and the bands. In an electrical motor the bands and brushes are placed as close to the centre of the spinning axis as possible to reduce the surface speed, and are also covered to prevent foreign elements from destroying the contacts. Byrd's system has none of these qualities and because the wheels are exposed to constant dirt, high temperatures, and high surface speeds, system failure is certain. Also, the inventor does not take into account the usual need for tire changes and how inconvenient and difficult it becomes with a solid brush holder that must be precisely positioned to operate. There is also the certainty of failure from short circuits caused by water mixed with salts that conduct electricity across the brushes and bands.
Other solutions described by U.S. Pat. No. 6,612,726 to Goodt and U.S. Pat. No. 6,644,839 to Lee describes lights affixed to the body of the vehicle, which shine thru the openings in the rotating wheels. Neither solution is practical, though, as dirt, brake dust, and grime soon covers the lights rendering them unfunctional. Also, because of the proximity to the heat from the brakes that the lights are exposed to, they can actually melt or catch on fire.
U.S. Pat. No. 4,725,928 to Strepak, U.S. Pat. No. 4,728,431 to Park, and U.S. Pat. No. 6,116,763 to King all describe another typical solution to the problem in which they convert the rotational energy of the moving vehicle wheel to the electrical energy, which powers the lights by means of a generator. These systems are all bulky and complicated mechanisms, which rely on the motion of the vehicle for light. Since the vehicle stops frequently, and the lights shut off, there is a detrimental effect to the overall desired effect.
U.S. Pat. No. 4,763,230 to Cummins, U.S. Pat. No. 5,016,144 to DiMaggio, U.S. Pat. No. 6,059,431 to Ellis. Jr., U.S. Pat. No. 6,220,733 to Gordon, U.S. Pat. No. 6,565,243 to Cheung, U.S. Pat. No. 6,742,913 to Deutsch, U.S. Pat. No. 5,683,164 to Chien, and U.S. Pat. No. 6,572,251 to Huang all describes battery powered lighting systems for wheels. A major downfall of these devices is the dying of the batteries, and while it is easy to imagine them with rechargeable batteries, the batteries would still have to be manually replaced. Many also require manual switching "on" of the devices, while others require motion sensors for activation and do not function on a stationary vehicle.
U.S. Pat. No. 5,357,238 to Terada describes a solar cell that is attached to the outside of the wheel to catch sunlight in order to recharge the batteries. Unfortunately, because solar cells produce very little energy unless they have a great surface area, this is impractical. Solar cells only work well when facing the sun or other light source. Being attached to the wheel, they are parallel to the suns rays and ineffective. Solar cells are also quite expensive and fragile which would be of great concern to a consumer considering that they are attached to the wheels, which are made durable because of the harsh conditions that they encounter.
U.S. Pat. No. 6,116,762 to Kutlucinar sums up all the problems of the battery-operated systems. Most notable is that it describes a kit, which comes with a portable re-charger to recharge one set of batteries while the user uses another set until they are dead. One must assume that the user would have to change the batteries every couple of days. Also, this system only works while the vehicle is in motion.
The present inventor understands that the common consumer desires devices that are automatic. They do not wish to switch on the wheel lights before they travel. They do not wish to switch the lights off at the end of their trips. They do not wish to perform maintenance every couple of days. In regards to a wheel lighting device, they want to get in their car and start the engine and have the lights turn on. They want to shut their cars off and have the lights switch off as well. While, because rechargeable batteries cannot be recharged infinitely, and the present invention relies on rechargeable batteries, it also needs maintenance like other devices, those devices produce a small amount of light on the magnitude of hours before servicing, while the present invention produces a large amount of light on the magnitude of years before servicing.
Another feature of the present invention is its ease of installation and universal application to all existing and future vehicles.

Automatic on, off, and recharging vehicle wheel lighting device


Each driver circuit included in a word driver includes a transfer transistor and a driver transistor. A voltage of a predetermined voltage lower than a threshold voltage of the transfer transistor plus a power supply voltage is applied to the gate of the transfer transistor in an active period.

1. Field of the Invention
The present invention relates to semiconductor memory devices, and more particularly, to an improvement of a word driver for driving a word line.
2. Description of the Background Art
FIG. 17 is a block diagram showing a configuration of a conventional dynamic random access memory (hereinafter referred to as a DRAM). This DRAM is formed on a semiconductor chip CH.
A memory cell array 1 includes a plurality of word lines, a plurality bit lines crossing the plurality of word lines, and a plurality of memory cells connected to crossings of these word lines and bit lines. In FIG. 17, a word line WL, a set of bit line pairs BL, /BL and a memory cell MC connected to a crossing thereof. Each memory cell MC includes a capacitor for storing data and an N channel transistor. The N channel transistor is connected between the capacitor and a bit line, having its gate connected to a word line.
An RAS buffer 2 receives an external row address strobe signal /RAS to generate an internal row address strobe signal iRAS and a timing signal RAL. A CAS buffer 3 receives an external column address strobe signal /CAS to generate an internal column address strobe signal iCAS. A WE buffer 4 receives an external write enable signal /WE to generate an internal write enable signal iWE.
A row address buffer 5 receives an external address signal ADD to generate a row address signal RA in response to the timing signal RAL. A row decoder 6 selects any one of the plurality of word lines in the memory cell array 1 in response to the row address signal RA. A word driver 7 drives the word line WL selected by the row decoder 6 to a predetermined voltage. Data is read from a plurality of memory cells connected to selected word lines WL to respective corresponding bit line pairs. Data read to each bit line pair is amplified by a sense amplifier 12.
A column address buffer 10 receives the external address signal ADD to generate a column address signal CA in response to the internal column address strobe signal iCAS. A column decoder 11 selects any one of the plurality of bit line pairs in response to the column address signal CA. Accordingly, a selected bit line pair BL, /BL is connected to an input/output line pair IO, /IO.
In a write operation, an externally applied input data Din is provided to the input/output line pair IO, /IO through an input circuit 13. In a read operation, data on the input/output line pair IO, /IO is provided outside the chip through an output circuit 14 as output data Dout.
An RXT generating circuit 8 generates a timing signal RXT in response to the internal row address strobe signal iRAS and a portion of the row address signal RA, RAn, /RAn. An RX generating circuit 9 generates a driving signal RX having a higher voltage than a power supply voltage in response to the timing signal RXT. A control circuit 15 generates various control signals for controlling each portion in response to the internal column address strobe signal iCAS, the internal write enable signal iWE and the column address signal CA.
FIG. 18 is a diagram showing a detailed configuration of the row decoder 6 and the word driver 7.
The row decoder 6 includes a plurality of decoder circuits 60 corresponding to the plurality of word lines WL. The word driver 7 includes a plurality of driver circuits 70 corresponding to the plurality of word lines WL.
Each of the decoder circuits 60 includes an NAND gate G1. A 1-bit signal RAk of the row address signal RA or an inverted signal thereof /RAk is applied to each input terminal of the NAND gate G1, where k is an integer of 1 to n.
Each of the driver circuits 70 includes an inverter G2 and N channel transistors TR1, TR2, TR3. The transistors TR1 and TR2 are referred to as a transfer transistor and a driver transistor, respectively.
A node N1 is connected to the input terminal of the inverter G2 and the gate of the transistor TR3. The input terminal of inverter G2 is connected to a node N2. The transfer transistor TR1 is connected between the node N2 and a node N3. A power supply voltage Vcc is applied to the gate of the transfer transistor TR1.
The node N3 is connected to the gate of the driver transistor TR2. The driver transistor TR2 is connected between a node NX for receiving the driving signal RX and the word line WL. The transistor TR3 is connected between the corresponding word line WL and a ground terminal for receiving a ground potential Vss. The node N1 is connected to an output terminal of the corresponding decoder circuit 60.
Operations of a driver circuit shown in FIG. 18 will now be described with reference to a timing chart in FIG. 19. A period when the external row address strobe signal /RAS is at a logic high or "H" level is referred to as a stand-by period, while a period when the external row address strove signal /RAS is at a logic low or "L" level is referred to as an active period.
When the external row address strobe signal /RAS falls to "L", the internal row address strobe signal iRAS rises to "H" as well as the timing signal RAL rises to "H", thereby causing the external address signal ADD to be applied as the row address signal RA. As a result, the row decoder 6 decodes the row address signal RA to cause an output signal (a selecting signal) of a plurality of decoder circuits 60 to fall to "L".
Accordingly, the potential of the node N1 falls to the ground potential, causing the potential of the node N2 to rise to the power supply voltage Vcc. As a result, the potential of the node N3 becomes Vcc-Vth, where Vth is the threshold voltage of the transfer transistor TR1.
The driving signal RX rises to a high voltage Vcc+.alpha. in response to rise of the timing signal RXT. As a result, the potential of the node N3 is boosted to 2Vcc+.alpha.-Vth by a self-boosting operation of the driver transistor TR2 to cause the potential of the word line WL to rise to Vcc+.alpha.. Normally, .alpha. is set to a higher voltage than the threshold voltage of a transistor of the memory cell MC.
A power supply voltage Vcc is an internal power supply voltage down-converted by an external power supply voltage or an internal voltage down converting circuit.
A semiconductor memory device operating at a low power supply voltage is being developed in recent years with devices miniaturized. As will be described hereinafter, a low power supply voltage poses a problem of a slow rising rate of a voltage of the word line.
Assume that the power supply voltage Vcc is 5 V and that the threshold voltage Vth of the transfer transistor TR1 is 1.0 V. .alpha. is also assumed to be 1.0 V. In this case, the potential of the node N3 first rises from 0 V to 4 V. When the driving signal RX is pulled up from 0 V to 6 V, the potential of the node N3 rises from 4 V to 10 V.
Next, assume that the power supply voltage Vcc is 1.5 V and the threshold voltage Vth of the transfer transistor TR1 is 0.7 V. .alpha. is also assumed to be 1.0 V. In this case, the potential of the node N3 first rises from 0 V to 0.8 V. When the driving signal RX is pulled up from 0 V to 2.5 V, the potential of the node N3 rises from 0.8 V to 3.3 V.
As described above, when the power supply voltage Vcc is 5 V, the gate voltage of the driver transistor TR2 first attains 4 V, while when the power supply voltage Vcc is 1.5 V, the gate voltage of the driver transistor TR2 first attains 0.8 V. In other words, the lower power supply voltage brings about a smaller ratio of the voltage of the node N3 to the power supply voltage, because a ratio of the threshold voltage to the power supply voltage becomes larger.
Therefore, the conductance gm of the driver transistor TR2 becomes smaller, causing a self-boosting operation of the driver transistor TR2 to be slower. As a result, there is a problem of a longer rising time Td of the voltage of the word line WL.

Semiconductor memory device having a word driver


A pier mat of erosion control blocks for abating erosion around piers of a wharf. A mat of blocks is arranged so as to have a linear end edge and a vacant space formed in an opposite end edge thereof, where the vacant space is for surrounding at least a part of a pier. A linear end edge of another similar pier mat is installed so as to abut the end edge of the first mat having the vacant space, thereby fully surrounding the pier. A method of installing a pier mat of erosion control blocks is also disclosed.

Articulated Concrete Mats (ACM) of erosion control blocks have been utilized since the early 1960's in the United States to prevent the erosion of soil. The mats are fabricated using a number of erosion control blocks cabled or otherwise fastened together. These mats were/still are referred to as pre-assembled mats with cables that allow for lifting and placement of the mats using a spreader bar hoisted by a crane or other heavy equipment, such as a hydraulic excavator. The size of mats range generally up to 8 feet in width and up to 40 feet in length, i.e., the maximum size for semi-tractor/trailers in order to haul the mats to the construction job sites. It is also common to have different widths and lengths of mats to accommodate on-site installation of projects requiring different mat sizes, for example 8′×16′ mats, 8′×24′ mats, or 8′×40′ mats, and 6′×30′ mats.
FIG. 1 is an example of a common pre-assembled mat 10 that has been available for over 60 years. The mat 10 includes a number of blocks 12 cabled together, and lifted with a steel spreader bar 14 for loading onto trucks to be delivered to job sites. The spreader bar 14 is generally rectangular and lifted at its four corners by cables, one shown as numeral 16. Two or more guide cables 22 and 24 can be employed for workmen to guide the suspended mat 10 onto the desired location, such as stacked on top of another mat previously loaded on a trailer bed. The mat 10 of blocks 12 is suspended from the opposite ends of the spreader bar 14 with cables 18. In the illustration, there is one chain 18 for each column of blocks in the mat 10. The mat 10 shown in FIG. 1 is 4′×31′. Several previous ACM configurations for mat systems are illustrated in U.S. Patents, and include U.S. Pat. Nos. 8,678,705; 4,227,829; 4,370,075 and 5,484,230. One can see that all previous ACM teaches one skilled in the art to lift corresponding mats with equal widths on both ends of mats. These types of ACM are all the same with respect to the width of the mats on both longitudinal ends of all mats when being lifted, for example, 8-foot widths. The cables that hold the blocks of a mat 10 together extend from the ends of the mat 10 and form loops 20. The loops 20 function as "lifting hooks" for a spreader bar 14 using chains 18 to lift the mats 10. Other individual lateral cables are threaded through the blocks 12 to hold the blocks together.
The blocks 12 of the mat 10 of FIG. 1 are each cabled together with synthetic ropes or cables to hold the individual blocks together as a mat or unit, as well as to be lifted by the spreader bar 14 to move the mat 10 from either the shore or a truck bed to an underwater location. The spreader bar 14 is connected to the looped synthetic cables 20 that extend beyond the opposite ends of the mat 10, and the mat 10 is then lifted. The mat 10 that is suspended at the ends by the spreader bar 14 becomes arc-shaped, with the middle of the mat 10 bowed down in the middle, also as shown in FIG. 1. When lowered into position onto the ground at the water-covered surface, the looped cables 20 at each end of the mat 10, and the individual cable pigtails at each side of the mat 10 can be connected by divers to the corresponding cables of adjacent mats. Any number of mats can be installed in the underwater location so as to cover a level or contoured area. As can be appreciated, when the underwater location is populated with one or more vertical protrusions, such as piers, then a mat 10 of blocks shown in FIG. 1 is not easily employed. One reason is that the spreader bar 14 is linear at each end and would thus engage the pier and prevent the mat from being laid on at least three sides of the pier.
As noted above, the erosion of banks and other similar sloped locations can be prevented by either installing individual interlocking erosion control blocks on such banks, or by installing large mats of cabled erosion control blocks using a crane. The erosion control blocks can be individually installed by workmen, which is labor intensive, or the blocks can be cabled together (as described above) into a mat and installed using a crane or the like. Either technique is adequate to cover the ground area with erosion control blocks and prevent erosion of the earth material during heavy rains, flooding or turbulent water caused by ships and the associated propulsion systems. Large mats of erosion control blocks have been installed in waterways and at ocean shores and the like. In these situations, the erosion control blocks are arranged in a mat and cabled together and then lifted by a crane and lowered into the water and onto the underlying ground to protect the same from erosion. Often the erosion control blocks are interlocking, and thus divers are required to guide the edges of a new mat into an interlocking relationship with the interlocking edges of the previously laid mat. If an occasional vertical obstacle is encountered in the installation of the underwater mats, then the mats are attempted to be laid around the obstacle, and the uncovered area around the obstacle is grouted to protect such area from erosion. The grouting of the uncovered area requires additional material and labor efforts and is thus costly and time consuming.
There is a need for a specialized pre-assembled ACM with a U-shaped void formed into one edge thereof. Such a mat can be installed around three sides of a concrete pier, such as used to construct bridges, barge terminals, and wharf expansions. Barge terminals and wharf expansions commonly install pre-assembled ACMs under water on steep slopes to protect the slopes from erosion caused by large barge vessels that come into dock at port harbor authorities, chemical plants, and wharf terminals. Many large barge vessels have side jet thrusters that create substantial underwater turbulence, thus causing severe erosion of the underwater slopes and embankments that are intended to protect the terminals and wharfs.
Terminals and wharf expansions have concrete piers placed all along and in the slopes at underwater locations, many of which are 25-40 feet deep. These piers function as the bracing members to support the terminal platforms above ground where barges and other vessels dock. The ACM are placed on the slopes and must also be placed around these piers for erosion control protection. It is quite common to construct the concrete piers first, then to place the ACM around the piers for the erosion protection.
While the foregoing techniques function well for installing mats of erosion control blocks on flat or contoured areas, a problem exists when the mats of erosion control blocks are to be installed around the many piers supporting wharfs and bridge piers, and other similar situations. A further need exists for installing mats of erosion control blocks around vertical protrusions from the ground, such as trees and poles, and on ground areas not covered with water. A need exists for a new type of mat of erosion control blocks that can be installed on the ground, or underwater around the wharf piers, without the needless use of grouting large and uncovered areas immediately adjacent to the piers or tree. A further need exists for both a mat and a spreader bar that can efficiently install the mat around at least a portion of a pier.

Articulated block mat for use with harbor piers and method of installing a pier mat


A watercraft lift assembly is provided. The watercraft lift assembly may include a frame, a pair of opposing cantilever arm assemblies and a lifting system. The frame may include a plurality of vertical posts and overhead elements forming a generally simple cubic lattice frame defining a watercraft operational envelope. Each cantilever arm assembly may include a pair of cooperating cantilever arms. Each cantilever arm may be generally L-shaped having a horizontal arm portion and a vertical arm portion slidably secured to an adjacent vertical post. Each horizontal arm portion may include a housing for slidably receiving an extension element. On each cantilever arm assembly, a cantilever bunk may be pivotably connected to the ends of the cooperating extension elements so as to operably engage the bottom surface of various watercrafts when the pair of cantilever arm assemblies moves from a low position to a raised position under the power of the lifting system.

The present invention relates to watercraft lift assemblies and, more particularly, to a low water watercraft lift assembly.
Current vertical watercraft lifts utilize a beam and platform configuration. This is comprised of two horizontal beams spanning the width of the lift and additional beams spanning the length of the lift to create the platform. The watercraft resting beams (bunks) are attached above the horizontally spanning beams. This reduces the effective usability of the lift, by requiring increased water depth for operation, and as a result the current lifts cannot be utilized at the minimum manufacturer-rated water depth of many watercrafts. This is becoming an increasingly witnessed limitation as watercraft are increasing in hull volume (deeper V-Hulls) and utilizing more frequently hardware such as bottom rudders and inboard and inboards with V-Drives. During low water operations, watercrafts are either immobile or undergo large wear on the hulls as the watercraft is dragged across the bunks due to the watercrafts not being completely buoyed.
Current watercraft lifts that the platform configuration to support the bunks, limit the depth of operation by the thickness of the platform, plus any hardware used to attach the bunks.
As can be seen, there is a need for a watercraft lift assembly adapted without a platform so that it may be used in the minimum rated water depth for the lifted watercraft.


A surface light source device and a transmission display device are provided. A surface light source device includes a light source portion, a light controlling sheet located on the output light side of the light source portion, and a light diffusing sheet located on the output light side of the light controlling sheet and including micro-convex structures. The light diffusing sheet includes a transparent base film, and a light diffusing layer coated on a surface of the transparent base film. Micro-beads incorporated in the light diffusion sheet exhibit a lens effect and provide a light condensing effect and a light diffusing effect. As such, the output light properties of the surface light source device can be adjusted to be smoother, thereby providing higher front luminance and avoiding occurrence of moiré.

1. Field of the Invention
The present invention relates to a surface light source device for illuminating a liquid crystal display device or the like, and also relates to a transmission display device including the same.
2. Background Art
Various types of surface light source devices have been proposed and put to practical use, as surface light sources for illuminating transmission liquid crystal displays or the like from the back side. The surface light source devices are, primarily, classified into a type of converting a usual light source to a surface light source, and into an edge light type and a direct type.
For example, the direct type light source is configured to introduce light into a display device through the back side, by utilizing parallel cold-cathode tubes. In this case, the parallel cold-cathode tubes are spaced a suitable distance from a transmission display portion of an LCD panel or the like. Additionally, between those elements, a plurality of optical element sheets, each having a light diffusing effect and/or light converging effect, are combined.
As the optical element sheets used in the surface light source devices, there are optical sheets, in each of which a plurality of optical structures, such as lenses or prisms, are formed for the purpose of controlling the viewing angle (or output angle of light), or light diffusing sheets each configured for diffusing light.
When using such optical element sheets, however, due to the plurality of optical structures arranged regularly, moiré is likely to occur in each pitch of pixels (or picture elements) included in an LCD panel or the like.
Patent Document 1 discloses one example utilizing prism sheets and light diffusing sheets, in combination, for the surface light source device. As used herein, the prism sheet, while being not clearly defined in the Patent Document 1, is often used as an optical sheet for use in the surface light source device, and refers to products called luminance enhancing films or the like, each configured by arranging multiple unit optical structures (or unit prism structures), each having a cross section shaped as a generally isosceles right-angled triangle.
However, in the surface light source device utilizing the prism sheets as described above, while higher front luminance can be provided, the viewing angle properties tend to be drastically changed, as such the brightness and/or darkness is likely to be changed abruptly due to shifts of visual points.
In addition, the Patent Document 1 teaches only the combination of the optical sheets and light diffusing sheets, and does not refer to any way of combining the optical sheets and diffusing sheets of particular properties.
Patent Document 1: TOKUKAI No. 2006-120584, KOHO

Surface light source device and transmission display device


A method of inhibiting, ameliorating or reversing the effects of TGF-xcex2 in biological systems by exposing the bioligical systems with an agent which substantially represents active site peptide of the TGF-xcex2 molecules.

Transforming growth factor xcex2 (TGF-xcex2) is a family of 25-kDa structurally homologous dimeric proteins containing one interchain disulfide bond and four intrachain disulfide bonds. The TGF-xcex2 family is composed of three-known members (TGF-xcex21, TGF-xcex22, and TGF-xcex23) in mammalian species. TGF-xcex2 is a bifunctional growth regulator: it is a growth inhibitor for epithelial cells, endothelial cells, T-cells, and other cell types and a mitogen for mesenchymal cells. TGF-xcex2 also has other biological activities, including stimulation of collagen, fibronectin, and plasminogen activator inhibitor 1 (PAI-1) synthesis, stimulation of angiogenesis, and induction of differentiation in several cell lineages.
TGF-xcex2 has been implicated in the pathogenesis of various diseases such as intimal hyperplasia following angioplasty, tissue fibrosis, and glomerulonephritis. Neutralizing antibodies to TGF-xcex2 have been used experimentally to reduce scarring of wounds, to prevent lung injury in adult respiratory distress syndrome (ARDS), and to block restenosis following angioplasty in animal models. These promising results warrant the development of TGF-xcex2 antagonists (inhibitor) that might be useful in inhibiting, ameliorating or reversing the effects of TGF-xcex2 and treating diseases.
A method of inhibiting, ameliorating or reversing the effects of TGF-xcex2 in biological systems, comprising the step of exposing said biological systems with a binding agent, said binding agent is a peptide which substantially resembles a segment of the TGF-xcex2 molecules.
The binding agent is a peptide which substantially resembles an active site of the TGF-xcex2 molecules, hereinafter referred to as active site peptide.
The binding agent may be in the form of a peptide or other chemical agents which substantially resembles an active site of the TGF-xcex2 molecule, the binding agents occupy the TGF-xcex2 cellular receptors making the TGF-xcex2 cellular receptors unavailable for the binding of TGF-xcex2 molecules.
The biological systems may be either in-vitro or in-vivo.
Most preferably, the binding agent of TGF-xcex2 substantially corresponds to a peptide having an amino acid sequence substantially extending from residue 41 to residue 65 of TGF-xcex2 amino acid sequence. Most preferably, said binding agents correspond to an amino acid sequence motif preferably represented by WSXD (SEQ ID NO:10) and/or RSXD (SEQ ID NO:11), wherein X represents any amino acid.
Yet another object of the present invention is to provide an active site of TGF-xcex2 molecules. And to provide an amino acid sequence which substantially represents an active site of TGF-xcex2 molecules.
Yet another object of the present invention is to provide an agonist of TGF-xcex2 molecules, comprising a carrier molecule have a plurality of said binding agent. Furthermore, a method of producing an agonist of TGF-xcex2 molecules, comprising the step of conjugating a plurality of said binding agents to a carrier molecule.

Inhibitor of transforming growth factor xcex2 and A method of inhibiting the biological effects of transforming growth factor


The present invention provides a luminescent film containing at least a phosphorescent compound and a fluorescent compound, wherein the convolution integral value J of the emission spectrum of the phosphorescent compound and the absorption spectrum of the fluorescent compound satisfies equation (1), the light emission from the fluorescent compound accounts for at least 90% of the emission spectrum of the luminescent film, and the absolute photoluminescence quantum efficiency (PLQE) of the luminescent film is represented by equation (2). Equation (1): J≥1.5×1014, Equation (2): PLQE (a film composed of a phosphorescent compound and a host compound)×0.9≤PLQE (a film containing a phosphorescent compound and a fluorescent compound) [The lowest triplet excited state of the host compound is higher than the lowest triplet excited state of the phosphorescent compound, and does not suppress the luminescent property of the phosphorescent compound.]

As a light emitting type electronic display device, there is an organic electroluminescent (hereinafter also referred to as "organic EL") element.
An organic EL element has a configuration in which
a light emitting layer containing a light emitting compound (hereinafter also referred to as a "light emitting material") is sandwiched between a cathode and an anode, an exciton (exciton) is generated by injecting electrons and holes into the light emitting layer and recombining the layers, and light is emitted by using light emission (fluorescence and phosphorescence) when the exciton is deactivated. Light can be emitted at a low voltage of several V to several tens of V, and further, since the organic EL element is a self-luminescent type, it has a wide viewing angle, high visibility, and is a thin-film type complete solid-state element, and is attracted attention from the viewpoint of space saving, and portability.
As the development of the organic EL element in the future, the organic EL element which further enables the good luminous efficiency, luminance and chromaticity is desired.
From the viewpoint of high luminance, phosphorescent metal complexes containing heavy atoms such as Ir, Ru, and Pt are often used as the light emitting material rather than the fluorescent compound. This is because these metal complexes are capable of spin inversion, which is inherently forbidden from the singlet excited state to the triplet excited state, by the heavy atom effect, and can theoretically achieve an internal quantum yield of up to 100%.
However, although phosphorescent compounds having high luminous efficiency have been found, they have not been found to have satisfactory levels in terms of element lifetime and chromaticity. The reason for this is that the energy level of the lowest triplet excited state of the phosphorescent compound (hereinafter, also simply referred to as "level") is higher than that of the fluorescent compound, so that both the host compound and the phosphorescent compound are liable to be deteriorated, and the energy is liable to be transferred to a quenching substance having a low level generated during electric field driving.
Phosphorescent luminescent compounds have a decay lifetime ti of several as to several tens as, which is 2 to 4 orders of magnitude longer than the fluorescence lifetime of fluorescent materials. Furthermore, as the level of the triplet excited state increases, the emission spectrum from the phosphorescent compound and the absorption spectrum of the quencher tend to overlap, the energy transfer rate increases, and the element lifetime is shortened.
Here, the quenching phenomena from the light emitting material when the quenching material is generated can be explained by STERN-VOLMER equation (Numerical Formula (A)) shown below.
                                          PL                                      (                              with                                                                                Quencher                            )                                                          PL              0                                                  (                              without                                                                                Quencher                            )                                      =                              1                          1              +                                                K                  q                                ×                                  [                  Q                  ]                                ×                                  τ                  0                                                              =                      1                          1              +                                                K                  q                                ×                                  (                                                            K                      d                                        ×                    t                                    )                                ×                                  τ                  0                                                                                Numerical                                                  Formula                                                            (          A          )
In the above equation (A), PL (with Quencher) is the luminescence intensity in the presence of a quenching substance, PL0 (without Quencher) is the luminescence intensity in the absence of a quenching substance, Kq is the energy transfer rate from a luminescent material to a quenching substance, [Q](=Kd×t) is the quenching substance concentration, Kd is the generation rate of a quenching substance by aggregation or decomposition, t is the cumulative excitation time by light or current, and to is the phosphorescence half-life time of phosphorescence of a phosphorescent luminescent compound in the absence of a quenching substance.
That is, according to the formula (A), if the light emitting material has a short emission decay life to, such as a fluorescent compound, the light emitting life of the element (hereinafter, also referred to as "element lifetime") is expected to be long. However, as described above, in an organic EL element using a conventional fluorescent compound, the internal quantum yield does not exceed 25%.
Therefore, the high efficiency of the fluorescent compound was devised by the use of the triplet-triplet annihilation mechanism (hereinafter simply referred to as "TTA"). Although the triplet excited state of a general fluorescent compound is to be thermally deactivated, it is known that triplet excitons collide with each other by increasing the exciton density, and a singlet excited state is generated. The TTA mechanism is represented by the following formula (B), and one singlet exciton is generated from five triplet excitons. However, even if the TTA mechanism is used, the theoretical limit value of the external extraction quantum efficiency (EQE) is 8%, which is not as high as that of the phosphorescent compound.4(T1*+T1*)→S1*+3T1*+4S0 S1*→S0+hv  Formula (B)
S0 in Formula (B) above represents the ground state, S1 represents the singlet excitation level, T1 represents the triplet excitation level, and a symbol * represents the excitation state.
In addition, for example, in Patent Document 1, by using a TADF (thermally activated delayed fluorescence) luminescent compound as an assist dopant of the fluorescent luminescent compound, a technique for producing a highly efficient organic EL element is described. However, the luminescence decay lifetime (f) of the luminescent film to which the fluorescent luminescent compound has been added is still long on the order of μ seconds, and under high luminance and high current density, roll-off and the above-mentioned acceleration coefficient become large, so that the luminescence property is lowered, and consequently, the element lifetime is lowered.
In order to express the above Formula (B) in an organic EL element, it is necessary to increase the density of excitons as described above. Therefore, the light emitting position in the light emitting layer must be biased toward the hole transport layer (HTL: hole transport layer) or the electron transport layer (ETL: electron transport layer). When the materials constituting these layers are mixed (hereinafter also referred to as "the interface is mixed"), energy transfer to the adjacent layers occurs, and a decrease in exciton density leads to a decrease in luminous efficiency.
Mixing at the interface is remarkably manifested by film formation by the coating method. It is known that when a multilayered film is formed by a coating method, the interface with the light emitting layer (EML: emitter layer) is mixed by several nanometers, and it has been confirmed that, by increasing the transfer rate of energy to the adjacent layer, a significant decrease in light emitting efficiency is caused. Therefore, the element using the TTA mechanism by densification of the exciton can be implemented only in a limited layer configuration.
In fluorescence sensitization instead of TTA, for example, Patent Document 2 proposes that a fluorescent light emitting compound and a phosphorescent light emitting compound having a higher level of the lowest triplet excited state than the level of the singlet excited state of the fluorescent compound are combined to sensitize the singlet excited state of the fluorescent compound by Förster type energy transfer from the phosphorescent compound, thereby increasing the efficiency of light emission from the fluorescent compound. However, the exciton of the phosphorescent compound does not completely sensitize the fluorescent light emitting compound, and there is room for improvement because the exciton of the phosphorescent compound does not fully sensitize the fluorescent light emitting compound, and the lifetime of the device is not sufficiently improved.
As mentioned above, the following have been found.                Phosphorescent luminescent compounds should have a luminescence decay lifetime τ as long as several μs to several tens μs.        Since the level of the lowest triplet excited state of the phosphorescent substance is high, the emission spectrum from the phosphorescent compound and the absorption spectrum of the quencher are likely to overlap, and the energy transfer rate is increased.        From the above viewpoint, the material used for the host compound also becomes higher than the level of the lowest triplet excited state of the phosphorescent compound, which causes degradation during driving.
As can be understood from the above Formula (A), the three points are combined, which is a difficult factor to prolong the lifetime of the device by using the phosphorescent compound. Also in the techniques disclosed in Patent Documents 1 and 2, the element lifetime is not sufficient, and there remains a great room for improvement.

Luminescent film, organic electroluminescent device, and method for manufacturing organic electroluminescent device


An sputtering device includes a carrier that includes a main body and support members. The main body defines a receiving space and includes a lateral surface defining at least one groove extending along a longitudinal direction. The receiving space and the at least one groove communicate with each other. The at least one groove is defined by a first surface and a second surface. The first surface defines recessed portions along the longitudinal direction and communicates with the receiving space. The support members are used for hanging workpieces. Each of the support members includes at least one support arm protruding from the lateral surface and is selectively and movably retained by one of the recessed portions.

1. Technical Field
The present disclosure relates to sputtering devices and, more particularly, to a sputtering device having a carrier with adjustable support members.
2. Description of Related Art
Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles, which is commonly used for thin film deposition. During the process of sputtering, workpieces are hung on support arms protruding from a rotary member of a carrier. Generally, the support arms are fixed to the rotary member and the distances between the support arms are fixed. The fixed distances limit the sizes of workpieces that can be hung on the support arms.
Therefore, what is needed is a carrier for use during sputtering to overcome the aforementioned problem.

This patent is subject to a terminal disclaimer.


An actuator comprises: a housing which is provided with an opening; a slider which is installed so as to be movable relative to the housing; a drive means which is installed in the housing and which moves the slider; at least a pair of seal members which is disposed at the opening of the housing so as to face each other and which exhibits dust-proof and drip-proof functions by engaging with each other; and move-through members which are mounted to both sides of the slider in the movement direction thereof and which move through the pair of seal members. The move-through members each comprise: a move-through section which pushes apart the pair of seal members in the direction in which the pair is separated; a cover section which covers an expanded opening formed between the pair of seal members when the pair is pushed apart by the move-through section; and an opening restriction section which, when the pair of seal members is pushed apart from each other by the move-through section, restricts the amount of opening between the pair of seal members and in turn restricts the size of the expanded opening.

Patent Document 1 shows an example of actuator having dust-proof and drip-proof structures according to a conventional art.
The actuator is provided with a housing formed in a substantially U-shaped shape and having an opening, a drive means installed in the housing, a slider which is movable relative to the housing and driven by the drive means, a drive means cover disposed to close the opening of the housing from the upper surface direction and from the both right and left side surface directions, and a dust/drip seal means disposed between the housing and the drive means cover.
The dust/drip seal means has a structure of two-stage stacked seals, with a labyrinth structure by overlaying side covers of the housing with side covers of the drive means cover.
The movement of the slider is performed by moving through the seals by seal move-through members.


A control device determines whether or not the detected value of a unit conducting current output from a current sensor at least plural times is equal to or greater than a predetermined upper limit current at time of the start of the actuation of a gas sensor, and furthermore, determines that each of the units of the gas sensor is set in an abnormal state if a duration for a state in which it is determined that the detected value of the unit conducting current is equal to or greater than the predetermined upper limit current is equal to or longer than a predetermined upper limit time. On the other hand, if the duration for the state in which it is determined that the detected value of the unit conducting current is equal to or greater than the predetermined upper limit current is shorter than the predetermined upper limit time, it is determined that the detected value of the unit conducting current temporarily becomes equal to or greater than the predetermined upper limit current and each of the units is set in a normal state.

1. Field of the Invention
The present invention relates to a control device of a gas sensor such as a contact combustion type hydrogen sensor to be mounted on a fuel cell vehicle.
2. Description of the Related Art
For example, conventionally, a solid polymer electrolyte fuel cell comprises a stack (hereinafter referred to as a fuel cell), which is constituted by stacking a plurality of cells on a cell formed by interposing a solid polymer electrolyte membrane between a fuel electrode and an oxygen electrode from both sides. Hydrogen is supplied as a fuel to the fuel electrode and air is supplied as an oxidizing agent to the oxygen electrode, and a hydrogen ion generated by a catalytic reaction at the fuel electrode passes through the solid polymer electrolyte membrane and moves to the oxygen electrode, and causes an electrochemical reaction to oxygen at the oxygen electrode, thereby generating a power.
Referring to a fuel cell such as the solid polymer electrolyte fuel cell, there has conventionally been known a protecting device comprising a hydrogen detector (a gas sensor) in a discharge system on an oxygen side of the fuel cell and serving to block the supply of a fuel when detecting that hydrogen on a fuel electrode side leaks toward the oxygen electrode side through a solid polymer electrolyte membrane by means of the hydrogen detector such as disclosed in JP-A-6-223850.
As for the hydrogen detector, moreover, there has been known a hydrogen detector of a gas contact combustion type which comprises a pair of a gas detecting unit formed of a catalyst such as platinum and a temperature compensating unit and serves to detect the concentration of a hydrogen gas depending on a difference in an electrical resistance generated together with the temperature compensating unit set in a relatively low temperature state such as an atmospheric temperature when the gas detecting unit is brought into a relatively high temperature state by heat generated through a combustion in the contact of hydrogen with the catalyst such as platinum.
In the gas sensor described above, the abnormal state of the gas sensor, for example, the presence of a short circuit is detected based on the detected value of the conducting current of each unit. For example, in the case in which the detected value of the conducting current is increased to exceed a predetermined decision threshold, it is determined that the short circuit is caused by an unrecoverable breakage generated on each unit or an abnormality generated on a circuit system, and the operation of the gas sensor is thus stopped.
In the fuel cell such as the solid polymer electrolyte fuel cell described above, however, water (humidifying water) is mixed with a reaction gas supplied to the fuel cell (for example, hydrogen or air) by means of a humidifier in order to maintain the ion conductivity of the solid polymer electrolyte membrane, and furthermore, reaction product water is generated by an electrochemical reaction during the operation of the fuel cell. For this reason, an exhaust gas of the fuel cell, particularly, an exhaust gas on an oxygen electrode side has a high wettability.
In the protecting device of the fuel cell according to an example of the conventional art, therefore, a dew condensation is generated on a hydrogen detector provided in the passage for an off-gas having a high wettability which is discharged from the fuel cell due to the off-gas in some cases. In some cases in which the hydrogen detector of a gas contact combustion type is particularly provided in a discharge system on the oxygen electrode side of the fuel cell, the detected value of an conducting current is increased to exceed a predetermined decision threshold due to a short circuit caused by the condensed water when the current conductance is carried out in a state in which the humidifying water or the reaction product water is stuck onto a gas detecting unit, and it is determined that an unrecoverable abnormality is generated on the gas sensor and the operation of the gas sensor is thus stopped even if the dew condensation is temporarily generated.


A hierarchical multi-stage model of asset failure risk for complex heterogeneously distributed physical assets is built. The hierarchical multi-stage model considers heterogeneity of failure patterns for the assets. At least one data stream is analyzed to determine whether the hierarchical multi-stage model needs to be updated due to a change in the failure patterns. If the analysis indicates that the hierarchical multi-stage model needs to be updated, the hierarchical multi-stage model is dynamically updated to obtain an updated hierarchical multi-stage model.

Asset failure analysis and prediction includes a number of different pieces, such as failure frequency, failure association and failure predication. Assets are distributed over space and asset condition information is collected over time. Asset condition assessment is a process which varies over geographical areas. Current failure analysis and prediction processes are static in nature, and address the different pieces separately.

Multi-stage failure analysis and prediction

INTERNATIONAL BUSINESS MACHINES CORPORATION


Net which, in the unfolded state, has the form of a central part provided at the petrify with a number of flaps. Nets of this type are used to fix articles on pallets. The flaps in particular are subject to substantial loads and will frequently be damaged. So as to avoid the need to carry out extensive repair work on the net structure, it is proposed, according to the invention, to construct the net from various component nets. The production of the nets can likewise be facilitated in this way.

A net of this type is generally known in the prior art. Especially for air freight, articles are placed on, for example, aluminium pallets and held in place with the aid of a net. To this end, the pallet is provided with recesses at the edges, in which recesses fastenings, which are fixed to the four corners of the net, can be anchored. Rubbing against adjacent pallets leads to a relatively short life of the flaps, in particular in the vicinity of the point of fixing to the pallet.
Because nets of this type are fairly expensive--these nets are made, inter alia, of polyethene cord and are made by hand--such nets will be repaired in practice.
Nevertheless, at least 100,000 nets per year are consumed by the various airlines.
Because a net consists of a single thread which has been turned into a network with the aid of knot constructions, it will be understood that it is not easily possible to repair part of the net without this having serious consequences for all of the constructions of the net. An example of the construction of a net described above is found in U.S. Pat. No. 4,000,344.
German Offenlegungsschrift 2,907,683 discloses a net which can be fixed to other nets with the aid of chains. A construction of this type is expensive. Moreover, there is a risk of damage to the load by the chains and it is not guaranteed that there is adequate grip on the load at the location of the chains.
U.S. Pat. No. 4,000,344 proposes to form a net having a central panel and a plurality of wing sections being connected thereto. After connecting a central panel and the wing sections a circumferential strand is passed around the assembly of central panel and wing sections. Because of that it is impossible to replace parts of the net without disturbing the structure of the net assembly.

Net composed of a number of component nets


A nestable mid-depth beverage case has a bottom wall with upstanding side and end walls around its periphery and a plurality of container seating areas on its top surface. A continuous peripheral band forms a vertical upper wall section, and a plurality of spaced apart V-shaped columns connected between the bottom wall and the band form a lower wall section inset relative to the upper section to enable nesting of the container. Buttresses extend upwardly from the columns and across the band. The columns have flat, angled vertical surfaces facing toward adjacent seating areas to contact containers over a substantial part of their height and provide support in lateral and longitudinal directions. Each end wall has two columns and associated buttresses, and a handle with a large access opening is formed in each end wall by cutting away adjacent side edges of adjacent columns and buttresses and the bottom edge of the band.

Beverages are commonly packaged in containers ranging in size from about six ounces up to about two liters, although different size containers are sometimes used. To facilitate handling, these containers typically are placed in cases that normally hold from eight to twenty-four containers, depending upon the size of the containers and the style of the case.
Reusable molded plastic cases capable of holding the desired number of containers have been developed in the prior art. These cases have a bottom wall or floor and upstanding side and end walls around the periphery of the floor. Cases designed for smaller containers generally are of low-depth construction, and typically have tapered or outwardly inclined sidewalls so that the cases can nest with one another. Other cases that have been developed primarily for use with larger containers have a higher sidewall, i.e., approximately mid-depth construction, with a sidewall that is about one-half the height of beverage containers placed in the case. The sidewalls in these cases generally are vertical and of substantially uniform height. This type of case is referred to in the industry as a "box-style" case and is commonly used for holding containers of one liter size, although they could be designed to hold containers of other sizes, including from about twenty ounces up to two or three liters, for example. These box-style cases do not nest with each other or with cases or boxes of other designs. They do, however, have shallow interengaging structure at their tops and bottoms that permit the bottom of an upper box to extend about ⅜ of an inch into the top of a lower box, permitting the boxes to be stacked in stable relationship with one another.
The inability of box-style cases to nest requires a substantial amount of space for storage and shipment of the cases when empty, leading to increased cost in their use. Moreover, the planar or flat vertical sidewalls typically found in these cases do not provide secure support to containers placed in the case.
It would be desirable, therefore, to have a mid-depth beverage case designed for holding larger beverage containers, wherein the case is nestable and wherein the sidewalls provide secure support to containers placed in the case.


A medical device is described comprising a biodegradable terephthalate copolymer comprising the recurring monomeric units shown in formula I:

1. Field of the Invention
The present invention relates to biodegradable homopolymer and block copolymer compositions, in particular those containing both phosphonate and terephthalate ester linkages in the polymer backbone, which degrade in vivo into non-toxic residues. The copolymers of the invention are particularly useful as implantable medical devices and drug delivery systems.
2. Description of the Prior Art
Biocompatible polymeric materials have been used extensively in therapeutic drug delivery and medical implant device applications. Sometimes, it is also desirable for such polymers to be, not only biocompatible, but also biodegradable to obviate the need for removing the polymer once its therapeutic value has been exhausted.
Conventional methods of drug delivery, such as frequent periodic dosing, are not ideal in many cases. For example, with highly toxic drugs, frequent conventional dosing can result in high initial drug levels at the time of dosing, often at near-toxic levels, followed by low drug levels between doses that can be below the level of their therapeutic value. However, with controlled drug delivery, drug levels can be more easily maintained at therapeutic, but non-toxic, levels by controlled release in a predictable manner over a longer term.
If a biodegradable medical device is intended for use as a drug delivery or other controlled-release system, using a polymeric carrier is one effective means to deliver the therapeutic agent locally and in a controlled fashion, see Langer et al., xe2x80x9cChemical and Physical Structures of Polymers as Carriers for Controlled Release of Bioactive Agentsxe2x80x9d, J. Macro. Science, Rev. Macro. Chem. Phys., C23:1, 61-126 (1983). As a result, less total drug is required, and toxic side effects can be minimized. Polymers have been used as carriers of therapeutic agents to effect a localized and sustained release. See Leong et al., xe2x80x9cPolymeric Controlled Drug Deliveryxe2x80x9d, Advanced Drug Delivery Reviews, 1:199-233 (1987) and Langer, xe2x80x9cNew Methods of Drug Deliveryxe2x80x9d, Science, 249:1527-33 (1990); and Chien et al., Novel Drug Delivery Systems (1982). Such delivery systems offer the potential of enhanced therapeutic efficacy and reduced overall toxicity.
For a non-biodegradable matrix, the steps leading to release of the therapeutic agent are water diffusion into the matrix, dissolution of the therapeutic agent, and diffusion of the therapeutic agent out through the channels of the matrix. As a consequence, the mean residence time of the therapeutic agent existing in the soluble state is longer for a non-biodegradable matrix than for a biodegradable matrix, for which passage through the channels of the matrix, while it may occur, is no longer required. Since many pharmaceuticals have short half-lives, therapeutic agents can decompose or become inactivated within the non-biodegradable matrix before they are released.
This issue is particularly significant for many bio-macromolecules and smaller polypeptides, since these molecules are generally hydrolytically unstable and have low permeability through a polymer matrix. In fact, in a non-biodegradable matrix, many bio-macromolecules aggregate and precipitate, blocking the channels necessary for diffusion out of the carrier matrix.
These problems are alleviated by using a biodegradable matrix that, in addition to some diffusion release, also allows controlled release of the therapeutic agent by degradation of the polymer matrix. Examples of classes of synthetic polymers that have been studied as possible biodegradable materials include polyesters (Pitt et al., xe2x80x9cBiodegradable Drug Delivery Systems Based on Alipathic Polyesters: Application to Contraceptives and Narcotic Antagonistsxe2x80x9d, Controlled Release of Bioactive Materials, 19-44 (Richard Baker ed., 1980); poly(amino acids) and pseudo-poly(amino acids) (Pulapura et al., xe2x80x9cTrends in the Development of Bioresorbable Polymers for Medical Applications,xe2x80x9d J. of Biomaterials Appl., 6:1, 216-50 (1992); polyurethanes (Bruin et al., xe2x80x9cBiodegradable Lysine Diisocyanate-based Poly-(Glycolide-co-xcex5 Caprolactone)-Urethane Network in Artificial Skinxe2x80x9d, Biomaterials, 11:4, 291-95 (1990); polyorthoesters (Heller et al., xe2x80x9cRelease of Norethindrone from Poly(Ortho Esters)xe2x80x9d, Polymer Engineering Sci., 21:11, 727-31 (1981); and polyanhydrides (Leong et al., xe2x80x9cPolyanhydrides for Controlled Release of Bioactive Agentsxe2x80x9d, Biomaterials, 7:5, 364-71 (1986).
Specific examples of biodegradable materials that are used as medical implant materials are polylactide, polyglycolide, polydioxanone, poly(lactide-co-glycolide), poly(glycolide-co-polydioxanone), polyanhydrides, poly(glycolide-co-trimethylene carbonate), and poly(glycolide-co-caprolactone). Injectable polyphosphazenes have also been described as useful for forming solid biodegradable implants in situ. See, Dunn et al., in U.S. Pat. Nos. 5,340,849; 5,324,519; 5,278,202; and 5,278,201.
Polymers having phosphoester linkages, called poly(phosphates), poly(phosphonates) and poly(phosphites), are known. See Penczek et al., Handbook of Polymer Synthesis, Chapter 17: xe2x80x9cPhosphorus-Containing Polymersxe2x80x9d, 1077-1132 (Hans R. Kricheldorf ed., 1992). The respective structures of each of these three classes of compounds, each having a different side chain connected to the phosphorus atom, is as follows:
The versatility of these polymers comes from the versatility of the phosphorus atom, which is known for a multiplicity of reactions. Its bonding can involve the 3p orbitals or various 3s-3p hybrids; spd hybrids are also possible because of the accessible d orbitals. Thus, the physico-chemical properties of the poly(phosphoesters) can be readily changed by varying either the R or Rxe2x80x2 group. The biodegradability of the polymer is due primarily to the physiologically labile phosphoester bond in the backbone of the polymer. By manipulating the backbone or the side chain, a wide range of biodegradation rates are attainable. Kadiyala et al., Biomedical Applications of Synthetic Biodegradable Polymers, Chapter 3: xe2x80x9cPoly(phosphoesters): Synthesis, Physicochemical Characterization and Biological Responsexe2x80x9d, 33-57, 34-5 (Jeffrey O. Hollinger ed., 1995).
An additional feature of poly(phosphoesters) is the availability of functional side groups. Because phosphorus can be pentavalent, drug molecules or other biologically active substances can be chemically linked to the polymer. For example, drugs with xe2x80x94O -carboxy groups may be coupled to the phosphorus via an ester bond, which is hydrolyzable. The Pxe2x80x94Oxe2x80x94C group in the backbone also lowers the glass transition temperature of the polymer and, importantly, confers solubility in common organic solvents, which is desirable for easy characterization and processing. Kadiyala et al. at page 35.
Specifically, EP 386 757 discloses the use of poly(phosphate) esters as prostheses and therapeutic agent delivery vehicles, recognizing that the polymers are biodegradable because of the hydrolyzable phosphoester bond in the backbone. With phosphorous in the trivalent state, the polymers can be polyphosphates or polyphosphonates having the general formula:
where R and Rxe2x80x2 are organic or organometallic moieties, and n is from about 10 to about 105.
Similarly, EP 057 116 discloses biocompatible polyphosphate esters with difunctional oligomers joined by phosphate bridging structures of general formula I:
where nxe2x89xa72; OL is an oligomer, preferably chosen from the group compring polyethylene terephthalate and polybutylene terephthalate; Y and Z are the two functional groups of the oligomer, such as OH; and R can be a substituted or unsubstituted alkyl, aryl or aralkyl group. These compounds are described as allowing for easy adjustment of the biodegradability.
Kadiyala et al. specifically discloses reacting bis(2-hydroxyethyl) terephthalate with dimethyl phosphite to form the following biodegradable poly-(phosphite):
The corresponding terephthalate poly(phosphate) materials have been described as biodegradable materials in copending U.S. patent application Ser. No. 09/053,648 filed Apr. 2, 1998.
Login et al., in U.S. Pat. Nos. 4,259,222; 4,315,847; and 4,315,969, disclose a poly(phosphate)-polyester polymer having a halogenated terephthalate recurring unit useful in flame retardant materials, but without a phosphorus having a side chain.
A number of other U.S. patents disclose poly-(phosphonate) compounds that are useful for their flame retardant qualities, such as Ko et al., U.S. Pat. No. 5,399,654; Besecke et al., U.S. Pat. Nos. 4,463,159 and 4,472,570; Login et al., U.S. Pat. Nos. 4,259,222, 4,315,847, and 4,315,969; Okamato et al., U.S. Pat. Nos. 4,072,658 and 4,156,663; Schmidt et al., U.S. Pat. Nos. 4,328,174 and 4,374,971; and Hechenbleikner, U.S. Pat. No. 4,082,897, or for their soil release effects, such as Engelhardt et al., U.S. Pat. No. 5,530,093. Certain terephthalate poly(phosphonate) compounds are disclosed as flame retardants by Desitter et al., U.S. Pat. No. 3,927,231; Reader, U.S. Pat. No. 3,932,566; and Starck et al., Canadian Patent No. 597,473. However, there still remains a need for further materials that are particularly well-suited for making biodegradable medical devices and drug delivery systems.
Applicants now have discovered that medical devices can be advantageously be made of a composition comprising biodegradable terephthalate polymers comprising the recurring monomeric units shown in formula I:
wherein
R is a divalent organic moiety;
Rxe2x80x2 is an aliphatic, aromatic or heterocyclic residue;
x is xe2x89xa71; and
n is 3-7,500,
where the biodegradable polymer is sufficiently pure to be biocompatible and is capable of forming biocompatible residues upon biodegradation. Preferably, the device of the invention is adapted for implantation or injection into the body of an animal.
In another embodiment, the invention comprises polymer compositions comprising:
(a) at least one biologically active substance and
(b) a polymer having the recurring monomeric units shown above in formula I.
In a still further embodiment of the invention, a method is provided for the controlled release of a biologically active substance comprising the steps of:
(a) combining the biologically active substance with a biodegradable terephthalate polymer having the recurring monomeric units shown in formula I to form an admixture;
(b) forming the admixture into a shaped, solid article; and
(c) implanting or injecting the solid article in vivo at a preselected site, such that the solid, implanted or injected article is in at least partial contact with a biological fluid.

Biodegradable terephthalate polyester-poly (phosphonate) compositions, articles and methods of using the same

Abstract: wherein

Abstract: R is a divalent organic moiety;

Abstract: x is xe2x89xa71; and

Abstract: n is 3-7, 500,

Abstract: Compositions containing the copolymers and biologically active substances, articles useful for implantation or injection into the body fabricated from the compositions, and methods for controllably releasing biologically active substances using the copolymers, are also described.


Cement compositions, that comprise water, a cement, a strength-retrogression additive, and an acid, wherein the acid comprises ethylenediamine tetra acetic acid, nitrilotriacetic acid, or a combination thereof, are provided. Methods of cementing in a subterranean formation, methods of retarding the set time of a cement composition, and set retarder compositions also are provided.

The present invention relates to cementing operations, and more particularly, to set retarder compositions that comprise ethylenediamine tetra acetic acid and/or nitrilotriacetic acid, cement compositions that comprise the set retarder compositions, and associated methods.
Cement compositions are commonly utilized in subterranean operations, particularly subterranean well completion and remedial operations. For example, cement compositions are used in primary cementing operations whereby pipe strings such as casings and liners are cemented in well bores. In performing primary cementing, cement compositions are pumped into the annular space between the walls of a well bore and the exterior surface of a pipe string disposed therein. The cement composition is permitted to set in the annular space, thereby forming an annular sheath of hardened substantially impermeable cement therein that supports and positions the pipe string in the well bore and bonds the exterior surface of the pipe string to the walls of the well bore. Cement compositions also are used in remedial cementing operations such as plugging highly permeable zones or fractures in well bores, plugging cracks and holes in pipe strings, and the like.
These cementing operations generally occur under a wide variety of well bore conditions, for example, ranging from shallow wells (less than about 1,000 feet) to extremely deep wells (greater than about 35,000 feet). Generally, the cement composition should remain in a pumpable state until the cement composition has been placed into the desired location. To retard the set time of the cement composition, conventional set retarder compositions have been included therein. As used herein, the phrase "conventional set retarder compositions" refers to a wide variety of compositions commonly used in cementing operations for delaying the set time of a cement composition, including lignosulfates, hydroxycarboxy acids, phosphonic acid derivatives, synthetic polymers (e.g., copolymers of 2-acrylamido-2-methylpropane sulfonic acid ("AMPS")), borate salts, and combinations thereof. As used herein, the term "copolymer" refers to a polymer comprising two or more different monomers. Certain of these conventional set retarder compositions (e.g., synthetic polymers) may be costly to produce, which may add an undesired expense to the cementing operation. Further as temperatures encountered downhole increase, higher concentrations of the conventional set retarder compositions may be required to achieve a desirable level of set retardation, which, in turn, may lead to additional undesired expense to the cement operation. Even further, these conventional set retarder compositions may not provide a desired level of set retardation, for example, in wells having bottom hole circulating temperatures ("BHCT") above about 450° F. Therefore, these temperatures limit the temperatures at which a cement composition may be pumped using conventional set retarder compositions and, thus, limit the depths and associated temperatures at which well bores may be drilled and isolated with a cement composition placed in the annulus.

Set retarder compositions, cement compositions, and associated methods