To improve tensile strength without impairing flexibility and adhesion to concrete, and to form a thick coating in a surface layer part for preventing a basis material from being exposed by damage to the coating, a method of forming double coatings on a prestressing strand includes a primary painting process after a pre-treatment process, in which a resin coating is formed only at the surface layer, a secondary painting process in which respectively individual state resin coating is formed on an outer peripheral face of each of the core wire and surrounding wires under a loosened and separated state, thereby forming a double coating for each surrounding wire, and a finishing process of tightening and retwisting the surrounding wires about the core wire to an original state. The obtained prestressing strand has the double coating portions only at the surface layer and sufficient flexibility and adhesion to concrete.

1. Field of the Invention
The present invention relates to a method of forming synthetic resin powder paint coating on a prestressing strand used as tensioning members for a post-tensioning system or a pre-tensioning system of a prestressed concrete structure in a building structure or a civil engineering structure, i.e., a method of forming corrosion protection coating. In particular, it relates to a method of forming double coatings only on a surface layer part in case there is a fear of damage of corrosion protection coating on a prestressing strand in a special structure, and a prestressing strand obtained by this method.
2. Related Art
Generally, the prestressing strand has a structure in which fine surrounding wires are twisted around a core wire. This is for giving flexibility to the prestressing strand, and for obtaining adhesion strength to a concrete by means of helical groove parts formed by twisting the surrounding wires. Accordingly, also as a method of forming corrosion protection coating on the prestressing strand, there is desired a method which does not hinder the above properties. At present, several methods have become publicly known or well known as the method of forming corrosion protection coating on the prestressing strand.
A 1st prior art method utilizes a prestressing strand whose sectional shape is shown in FIG. 10. A method of forming corrosion protection coating for this prestressing strand is one in which first the prestressing strand is heated, surrounding wires 1b are temporarily untwisted from the circumference of a core wire 1a by a strand opener, the untwisted surrounding wires 1b untwisted are again returned to an original twisted state in a place where untwisted portions of the surrounding wires 1b enter into an electrostatic powder painting machine by 15 inches to 18 inches, a resin 50 during melting and adhering to (during gel time) the core wire 1a and the surrounding wires 1b is moved (caused to flow) to and filled in void portions between the core wire 1a and the surrounding wires 1b by twisting stresses of the surrounding wires 1b, and additionally, in order to prevent pinholes generated in the helical groove parts formed by twisting the surrounding wires 1b, a thick coating 51 (500-600 μm) is formed to make inner and outer parts monolithic, thereby obtaining a composite body (U.S. Pat. No. 5,208,077).
Further, a 2nd prior art method utilizes a prestressing strand whose sectional shape is shown in FIG. 11. The method of forming corrosion protection coating for this prestressing strand is one in which, after a surface preparation, the surrounding wires 1b of the prestressing strand are temporarily untwisted in order from the circumference of the core wire 1a by use of a loosening-and-untwisting device, the surrounding wires 1b are kept apart from the core steel wire 1a in a spacing necessary for a next process by a wire expander, the core wire 1a passes through a core-length adjusting device, and a synthetic resin powder paint is individually sprayed onto the whole outer peripheral face of each of the core wire 1a and the surrounding wires 1b by an electrostatic painting method and adhered by an electrostatic repulsive force, thereby forming a resin coating 52. It is a method of forming corrosion protection coating in which the powder paint adhered by the electrostatic repulsive force is heated and molten, forms the individual resin coating 52 by cooling after elapse of the gel time and a curing and standing time, and thereafter the untwisted surrounding wires 1b are twisted with respect to the core wire 1a to the original state by a tightening device (U.S. Pat. No. 5,362,326).
In the prestressing strand formed in this manner, since the coating is individually formed one by one over the whole outer peripheral face of each of the core wire 1a and the surrounding wires 1b, which is different than 1st prior art method, the properties, such as the flexibility and the adhesion strength to the concrete, demanded as the prestressing strand are not hindered at all and, moreover, a corrosion protection function is sufficient, so that it is evaluated that this corrosion protection method is an ultimate corrosion protection method for the prestressing strand.
Further, the prestressing strand in which the individual corrosion protection coating is formed on the whole outer peripheral face of each of the core wire 1a and the surrounding wires 1b by the corrosion protection method according to the 2nd prior art is excellent also in its tensile strength, and this excellent property conspicuously appears especially in a case where a stress amplitude is large. One example of test results when it is subjected to tensile fatigue tests under the same conditions as a usual prestressing strand before the corrosion protection working was as shown below.
TABLE 1Tensile fatigue test results (specification value 2 × 106 times)UpperLower limitlimitstressTest resultsstress(Pu × 0.45 −StressPressure(Pu × 0.45)25)amplitudeFinalNumber ofbondingKind ofσ maxσ minΔσnumber ofrupturedgripprestressingKgf/mm2Kgf/mm2Kgf/mm2repetitionsstrand(s)deformationstrand(tf)(tf)(tf)NPiece(s)ExistencePrestressing186(12)61(8.5)25(8.5)21.0 × 1042nonestrand before286(12)61(8.5)25(8.5)28.3 × 1041nonecorrosion386(12)61(8.5)25(8.5)36.6 × 1043noneprotectiontreatment(15.2 mm)Method of186(12)61(8.5)25(8.5) 400 × 104no rupturenoneUS-A-5362326286(12)61(8.5)25(8.5) 400 × 104no rupturenone(15.2 mm)386(12)61(8.5)25(8.5) 400 × 104no rupturenone
As apparent from the above test results (Table 1), it is understood that, among the general prestressing strand to which no corrosion protection treatment is applied and the prestressing strand which is described in U.S. Pat. No. 5,362,326 in which the individual corrosion protection coating is formed on the whole outer peripheral face of each of the core wire and the surrounding wires, the one in which the corrosion protection coating is formed is remarkably improved with respect to its tensile strength.
As a main factor of this, the fact is recognized that, by forming the individual coating on the whole outer peripheral face of each of the core wire and the surrounding wires, a portion where a metal-to-metal contact occurs is completely nullified, so that it becomes possible to prevent fretting corrosion, contact corrosion and the like. With such a corrosion protection method, not only is a corrosion protection function remarkably improved but also the tensile strength is remarkably improved. Accordingly, in this prestressing strand, in the case where the individual coating is formed on the whole outer peripheral face of each of the core wire and the surrounding wires, it is desirable that a thickness of the coating of each of the core wire and the surrounding wires is made about 250 μm of a range in which a helical constitution of the twisted surrounding wires is stably held and a twisted state is sufficiently maintained.
In the industry, a regulation of the thickness of this kind of coating is accomplished as follows in outline. Namely, according to many research results, it is reported that, in order to satisfy a corrosion resistance performance and dynamic performances (impact resistance, bending property, and ability to adhere to concrete), the coating thickness of 200±50 μm is adequate if a powder type epoxy resin painting is adopted. Further, also in experimental results of the FHWA (Federal Highway Administration) in the U.S.A., it is reported that a range of 170±50 μM is desirable.
Additionally, an article to be painted with a coating thickness under this regulation is "Steel Bar for Ferroconcrete under JIS G 3112 (Japanese Industrial Standards)" (deformed steel bar), and is one completely different from a round steel bar. And, it is one having protrusions (ribs) on its surface in an axial direction, and having protrusions (nodes) also in a direction other than the axial direction, so that the above regulation of the coating thickness is determined by sufficiently considering the fact that the article to be coated has a structure in which, in the protrusion portions, there are many corner places where the powder paint is difficult to adhere.
Accordingly, in a case of a simple round steel bar shape like the core wire and the surrounding wires in the prestressing strand, since the powder paint evenly adheres to its outer peripheral face, it is needless to say that there is no problem so long as the coating thickness is 200±50 μm.
Additionally, a 3rd prior art method utilizes a prestressing strand whose sectional shape is shown in FIG. 12. This prestressing strand is made for a case where there is a fear that the corrosion protection coating will be damaged by a special structure and thus a maximum coating thickness of 250 μm or more by which the coating can be stably held is demanded, and a double coating corrosion protection working is performed, with respect to the prestressing strand of the 2nd prior art, by additionally forming a thick resin coating 53 on its outer peripheral face (JP-A-11-200267)
In the 1st prior art, since it is the prestressing strand made monolithic in which the resin powder is moved (caused to flow) to and filled in the void portions between the core wire and the surrounding wires by the stresses twisting the surrounding wires during when the resin powder is molten and adhered to (during gel time) the core wire and the surrounding wires and the thick coating is formed also in the surface layer part, the flexibility demanded to the prestressing strand cannot be expected at all. Further, since it is not only impossible to expect an improvement in the tensile strength, but also the helical groove part due to twisting the surrounding wires becomes shallow, there arises a problem that the adhesion strength to the concrete is reduced.
Additionally, this prestressing strand is one in which the resin is filled in the internal spaces. However, it has a structure in which basis surfaces still contact each other in contact portions between the core wire and the surrounding wires and between the mutual surrounding wires, so that no corrosion protection coatings are formed between the core wire and the surrounding wires and between the mutual surrounding wires, and thus it cannot be said that a problem of so-called internal corrosion is solved.
Further, in the 2nd prior art method, the structure has the individual resin coating formed in each of the core wire and the surrounding wires of the prestressing strand. It is possible to expect improvements in the flexibility and the tensile strength demanded of the prestressing strand. However, in its corrosion protection coating formation process, the surrounding wires are twisted with respect to the core wire to the original state after the individual resin coating has been formed on each of the core wire and the surrounding wires, and the thickness of the resin coating individually formed is about 250 μm and thus it cannot be made so thickly, there is a problem that it cannot be used in such a situation or place that there is the fear that the corrosion protection coating will be damaged by the special structure and thus a thick coating is demanded in order to prevent an exposure of the basis surface by the damage of the coating.
Additionally, in the 3rd prior art, the thick coating is formed in the outer peripheral face of the prestressing strand by applying the double coating corrosion protection. However, the flexibility demanded of the prestressing strand is hindered by the thick coating formed in the outer peripheral face, and not only the tensile strength is hindered to no small extent but also the adhesion strength to the concrete is reduced because the helical groove parts in the outer peripheral face become shallow.
Accordingly, in the prior art methods, there are such problems to be solved that the improvement in the tensile strength should be intended so as not to impair the flexibility and the adhesion strength to the concrete demanded of the prestressing strand, and that the thick coating should be formed in the surface layer part (outer peripheral face) in order to prevent the exposure of the basic surface by the damage of the coating.

Method of forming corrosion protection double coatings on prestressing strand and prestressing strand produced by the method


Disclosed are screening assays for identifying compounds which modulate the activity of, or signaling via, B7-4, or PD-1, especially which modulate the binding of B7-4 or PD-1 to a target molecule Further disclosed are a vaccine and also other compositions which contain agents that modulate signaling via PD-1.

In order for T cells to respond to foreign proteins, two signals must be provided by antigen-presenting cells (APCs) to resting T lymphocytes (Jenkins, M. and Schwartz, R. (1987) J. Exp. Med. 165:302–319; Mueller, D. L. et al. (1990) J. Immunol. 144:3701–3709). The first signal, which confers specificity to the immune response, is transduced via the T cell receptor (TCR) following recognition of foreign antigenic peptide presented in the context of the major histocompatibility complex (MHC). The second signal, termed costimulation, induces T cells to proliferate and become functional (Lenschow et al. (1996) Annu. Rev. Immunol. 14:233). Costimulation is neither antigen-specific, nor MHC restricted and is thought to be provided by one or more distinct cell surface molecules expressed by APCs (Jenkins, M. K. et al. (1988) J. Immunol. 140:3324–3330; Linsley, P. S. et al. (1991) J. Exp. Med. 173:721–730; Gimmi, C. D. et al. 1991 Proc. Natl. Acad. Sci. USA 88:6575–6579; Young, J. W. et al. (1992) J. Clin. Invest. 90:229–237; Koulova, L. et al. (1991) J. Exp. Med. 173:759–762; Reiser, H. et al. (1992) Proc. Natl. Acad. Sci. USA 89:271–275; van-Seventer, G. A. et al. (1990) J. Immunol. 144:4579–4586; LaSalle, J. M. et al. (1991) J. Immunol. 147:774–80; Dustin, M. I. et al. (1989) J. Exp. Med. 169:503; Armitage, R. J. et al. (1992) Nature 357:80–82; Liu, Y. et al. (1992) J. Exp. Med. 175:437–445).
The CD80 (B7-1) and CD86 (B7-2) proteins, expressed on APCs, are critical costimulatory molecules (Freeman et al. (1991) J. Exp. Med. 174:625; Freeman et al. (1989) J. Immunol. 143:2714; Azuma et al. (1993) Nature 366:76; Freeman et al. (1993) Science 262:909). B7-2 appears to play a predominant role during primary immune responses, while B7-1, which is upregulated later in the course of an immune response, may be important in prolonging primary T cell responses or costimulating secondary T cell responses (Bluestone (1995) Immunity 2:555).
One receptor to which B7-1 and B7-2 bind, CD28, is constitutively expressed on resting T cells and increases in expression after activation. After signaling through the T cell receptor, ligation of CD28 and transduction of a costimulatory signal induces T cells to proliferate and secrete IL-2 (Linsley, P. S. et al. (1991) J. Exp. Med. 173:721–730; Gimmi, C. D. et al. (1991) Proc. Natl. Acad. Sci. USA 88:6575–6579; June, C. H. et al. (1990) Immunol. Today. 11:211–6; Harding, F. A. et al. (1992) Nature 356:607–609). A second receptor, termed CTLA4 (CD152) is homologous to CD28 but is not expressed on resting T cells and appears following T cell activation (Brunet, J. F. et al. (1987) Nature 328:267–270). CTLA4 appears to be critical in negative regulation of T cell responses (Waterhouse et al. (1995) Science 270:985). Blockade of CTLA4 has been found to remove inhibitory signals, while aggregation of CTLA4 has been found to provide inhibitory signals that downregulate T cell responses (Allison and Krummel (1995) Science 270:932). The B7 molecules have a higher affinity for CTLA4 than for CD28 (Linsley, P. S. et al. (1991) J. Exp. Med. 174:561–569) and B7-1 and B7-2 have been found to bind to distinct regions of the CTLA4 molecule and have different kinetics of binding to CTLA4 (Linsley et al. (1994) Immunity 1:793). A new molecule related to CD28 and CTLA4, ICOS, has been identified and seems to be important in IL-10 production (Hutloff et al. (1999) Nature 397:263; WO 98/38216), as has its ligand, which is a new B7 family member (Aicher A. et al. (2000) J. Immunol. 164:4689–96; Mages H. W. et al. (2000) Eur. J. Immunol. 30:1040-7; Brodie D. et al. (2000) Curr. Biol. 10:333–6; Ling V. et al. (2000) J. Immunol. 164:1653–7; Yoshinaga S. K. et al. (1999) Nature 402:827–32). If T cells are only stimulated through the T cell receptor, without receiving an additional costimulatory signal, they become nonresponsive, anergic, or die, resulting in downmodulation of the immune response.
The importance of the B7:CD28/CTLA4 costimulatory pathway has been demonstrated in vitro and in several in vivo model systems. Blockade of this costimulatory pathway results in the development of antigen specific tolerance in murine and human systems (Harding, F. A. et al. (1992) Nature 356:607–609; Lenschow, D. J. et al. (1992) Science 257:789–792; Turka, L. A. et al. (1992) Proc. Natl. Acad. Sci. USA 89:11102–11105; Gimmi, C. D. et al. (1993) Proc. Natl. Acad. Sci. USA 90:6586–6590; Boussiotis, V. et al. (1993) J. Exp. Med. 178:1753–1763). Conversely, expression of B7 by B7 negative murine tumor cells induces T-cell mediated specific immunity accompanied by tumor rejection and long lasting protection to tumor challenge (Chen, L. et al. (1992) Cell 71:1093–1102; Townsend, S. E. and Allison, J. P. (1993) Science 259:368–370; Baskar, S. et al. (1993) Proc. Natl. Acad. Sci. 90:5687–5690.). Therefore, manipulation of the costimulatory pathways offers great potential to stimulate or suppress immune responses in humans.

Methods for screening for compounds that modulate pd-1 signaling


A lighting device may include a plurality of semiconductor light sources arranged on a substrate which is brought into contact thermally with a heat sink, wherein the substrate is formed from a multiplicity of substrate modules which are held by a carrier and which each carry at least one semiconductor light source and are brought into contact electrically with one another.

A lighting device of this type has a plurality of semiconductor light sources, which can be embodied for example by an LED or a multichip LED module. Said semiconductor light source is usually arranged on a carrier material—called substrate hereinafter—which consists of ceramic. The arrangement including substrate and semiconductor light source is brought into contact thermally with a heat sink, such that the heat that arises during the operation of a semiconductor light source can be dissipated in order to prevent the LEDs from overheating. The use of ceramic as substrate material has the advantage, inter alia, that the electronics of the luminaire are electrically isolated from the heat sink, thereby satisfying the requirements of the respective protection classes. In accordance with these requirements, the LED lighting devices have to be electrically insulated from the heat sink and air clearances and creepage paths between LED luminaire and heat sink have to be taken into account for this purpose. What is problematic here is that as a result of these measures the thermal linking of the semiconductor light source is impaired and the service life thereof is thus reduced.
Semiconductor light sources are often also used for achieving standard-conforming electrical insulation with complex SELV operating devices, which require a very large amount of space in order to comply with the necessary air clearances and creepage paths.
Lamps or luminaires can be subsumed under the term "lighting device". In this regard, by way of example, OSRAM GmbH sells so-called LED retrofit tubes under the designation SubstiTUBE, which can be used as a replacement for conventional fluorescent lamps in luminaires, without necessitating a conversion of the luminaire. In the case of tubes of this type, a multiplicity of semiconductor light sources are arranged on the large-area substrate, which is very long in accordance with the tube shape. Both during production and in the installed state, these ceramic substrates can break in the event of slight bending of the luminaire. Furthermore, the ceramic materials required for producing such substrates are relatively expensive, and so the lamp price is determined not inconsiderably by the proportion of ceramic.
In conventional luminaires, too, such as are described for example in document DE 10 2008 039 364 A1, the semiconductor light sources are arranged on a ceramic substrate which is configured likewise with a large area or in very complex forms, depending on the geometry of the luminaire, with the result that the same problems as with the tubes occur.


A reinforced lacrosse head having improved strength can include the following frame elements: a pair of opposing sidewalls each having a top end and a bottom end, a scoop extending between the sidewalls, a base extending between the bottom ends of the sidewalls, and a throat extending from the base for attachment to a lacrosse handle. The head can include at least one reinforcement member that is located at least partially in a frame element. The frame element can be constructed from two or more parts that are sonic welded or hot plate welded together around at least a portion of the reinforcement member. Methods of sonic welding or hot plate welding components of a reinforced frame element also are provided.

The present invention relates generally to a lacrosse head for attachment to a lacrosse stick, and more particularly to a lacrosse head having increased strength without substantially increasing the weight of the lacrosse head.
Lacrosse heads are used in the game of lacrosse for catching, holding and shooting a lacrosse ball. Most current lacrosse heads are manufactured using plastic injection molding processes, and are secured to a lacrosse handle. A typical lacrosse head includes a throat that is connected to a lacrosse handle, a base adjacent the throat and including a ball stop, a pair of opposing sidewalls that generally diverge from the base, and a scoop that joins the ends of the opposing sidewalls opposite the base. Lacrosse heads also typically include netting attached to the rear side of the base, the sidewalls and the scoop. This netting ordinarily is used to retain a lacrosse ball in the lacrosse head.
The sidewalls of current lacrosse heads typically have an open sidewall construction that includes many openings formed in the sidewalls. This open-frame construction decreases the amount of material used to form the sidewalls and thus the head, thereby decreasing the overall manufacturing and material costs for the head.
One proposed solution to this structural weaknesses provides stiffening ribs integrally formed in the head and extending from the socket or the base on toward the scoop. The stiffening ribs typically are located above and below the sidewall openings to provide structural support. The stiffening ribs usually are thicker than the main portion of the sidewalls to increase the structural integrity of the sidewalls. In such a construction, the lacrosse head is constructed from plastic with the stiffening ribs integrally molded as part of the head during a single molding process. Unfortunately, however, the stiffening ribs may not be sufficiently strong to prevent deformation or breakage of the lacrosse head. Such ribs also can add too much material, and thus weight, to the lacrosse head, thereby yielding an undesirably heavy lacrosse head.

This patent is subject to a terminal disclaimer.

Reinforced lacrosse head and related method of manufacture


A primer for promoting adhesion between an elastomeric adhesive and a nonporous substrate containing a silane-modified saturated polyester polymer and an adhesion promoter in an anhydrous solvent. The invention is also directed to a silane-modified saturated polyester polymer, and an adhesion promoter made by the reaction of a multifunctional isocyanate and an organosilane.

In the manufacture of motor vehicles, glass components, such as windshields, side windows and backlights, are joined to the metal vehicle body by means of an elastomeric adhesive material which may also function as a sealant. The adhesive materials which are used for this purpose are required to meet a number of criteria including appearance, ease of application, shear strength, and adhesion in crash tests. Therefore, good adhesion is required between the adhesives and the various nonporous metal, glass and polymeric substrates to which it is bonded.
In order to obtain acceptable levels of adhesion between the adhesives and the nonporous surfaces, various primers have been used to precoat the nonporous surfaces to enable the adhesive to bond better to them. In original equipment manufacture and glass replacement processes, primers are generally applied to both the metal and glass surfaces prior to application of the adhesive. The metal surfaces may be aluminum or steel, and may be bare, treated, or coated with various types of paints or enamels. Various polymeric materials may also be used in place of the glass components, or as structural members in place of the metal components. A current technique for joining glass to metal in vehicles uses an elastomeric urethane or silylated urethane adhesive. Other elastomeric adhesives which can be used include silyl-terminated polyethers and silicones. All of these adhesives may also be used to bond polymeric substrates to glass or metal, or to each other.
A number of primer compositions have been proposed for promoting adhesion between urethane adhesives or sealants and nonporous materials in technologies relating to motor vehicle manufacture as well as other areas.
For example, U.S. Pat. No. 3,707,521, and its divisional, U.S. Pat. No. 3,779,794, discuss a polyurethane adhesive primer composition comprising a branched polyurethane polymer in combination with a latent catalyst for the moisture curing of free isocyanate groups present.
U.S. Pat. No. 4,882,003 is directed to sealant primer compositions useful for promoting adhesion to enamel paint coated substrates, in which the primer comprises an acrylic polymer base composition, pigment, and a solvent effective to interpenetrate the enamel substrate coating.
U.S. Pat. No. 4,857,366 describes the use of a primer solution of p-toluenesulfonic acid and an organofunctional silane in solvent prior to applying an uncured urethane sealant to painted or glass surfaces.
U.S. Pat. No. 4,625,012, incorporated herein by reference for its discussion of isocyanatosilane adducts, describes a method of making a polyurethane polymer by reacting an isocyanatosilane adduct having at least two isocyanato groups with another isocyanate and a polyol.
U.S. Pat. No. 5,238,993 is directed to a primer comprising a solution of a polyester resin derived from a carboxylic acid and a glycol, an isocyanate and a silane-containing moiety dissolved in a particular mixture of solvents.
Because of the different properties of the various coated and uncoated metal, glass and polymeric substrates, different primers have been used on different types of substrates to obtain optimal adhesion with the adhesives. That is, each nonporous surface being bonded may require its own specific type of primer. Furthermore, primers used with urethane adhesives may not be acceptable for use with silylated urethane, silyl-terminated polyether or silicone adhesives. Therefore, a wide variety of primers have been needed to promote the bonding of different adhesives to different glass, metal and polymeric substrates.
For original equipment manufacturers, it may be reasonable to select a specific primer for a particular combination of adhesive and substrate, and to use different primers on the metal, glass and polymeric surfaces. However, for glass replacement operations working with a variety of metal, glass and polymeric substrates, as well as various adhesive materials, it can be very difficult to maintain and use a wide variety of different primers.
Thus, there is a need for a universal primer which can be used to promote adhesion between the various elastomeric adhesives and the different nonporous substrates to which they must adhere. There is a particular need for such a primer which can be used with the newer silylated urethanes and silyl-terminated polyethers as well as with the conventional urethane adhesives.

Primer for improving the bonding of adhesives to nonporous substrates


A truck bed canopy is arranged to include a plurality of parallel slide rails arranged for sliding reception within side wall rail members mounted to upper top walls of vehicular truck bed side walls. A lock pin is directed through the slide rail and associated companion side wall rail member to selectively secure the components together permitting ease of assembly and disassembly of the associated truck bed canopy relative to the truck bed.

1. Field of the Invention
The field of invention relates to canopy mounting structure, and more particularly pertains to a new and improved truck bed canopy mount wherein the same is arranged for the ease of mounting and dismounting of a truck bed canopy relative to an associated truck bed.
2. Description of the Prior Art
The use of accessory structure to mount truck bed accessories thereto are utilized in the prior art and exemplified in U.S. Pat. Nos. 4,650,382 and 4,936,724 wherein a truck bed employs various projections thereon to secure various cargo within an associated truck bed.
U.S. Pat. No. 4,958,875 to Zamzow sets forth structure to be received within truck bed side wall pockets to permit securement of a framework within the pockets to permit the subsequent protecting of rail structure relative to an associated truck bed.
The instant invention attempt to overcome deficiencies of the prior art by providing for a truck bed canopy mount structure addressing both the problems of ease of use as well as effectiveness in construction permitting the ease of mounting and dismounting of a truck bed canopy relative to an associated truck bed and in this respect, the present invention substantially fulfills this need.


A modified bismaleimide resin of Formula (I) or (II) is provided.

1. Field of the Invention
The invention relates to a modified resin, and more particularly to a modified bismaleimide resin, a preparation method thereof and a composition comprising the same.
2. Description of the Related Art
According to the implementation of the Restriction of Hazardous Substance (RoHS) Directive, using environmentally friendly materials has become a basic requirement. Although the Restrictions of the Hazardous Substance (RoHS) Directives of various nations are different, the substantial contents are similar. For example, most nations prohibit the use of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE). Thus, developments of green halogen-free copper clad laminate (CCL) materials and lead-free manufacturing processes are required. However, lead-free solder alloy has a higher melting point than that of conventional tin-lead solder, impacting circuit substrate materials and other auxiliary elements. While tin-lead solder has been replaced by a lead-free solder alloy, without other supporting measures, the reliability of the substrate has deteriorated. Thus, the development of substrate materials capable of bearing multiple high temperature manufacturing processes is required. During high temperature manufacturing processes, z-axis expansion and decomposition of substrate materials may occur. A high soldering temperature leads to an increased z-axis expansion of substrate materials, deteriorating through hole reliability. Also, substrate materials are easily decomposed during high-temperature soldering operations, deteriorating material properties, for example, increased moisture content, reduced glass transition temperature and deteriorated dielectricity. Thus, development of substrate materials with high thermal resistibility is currently desirable. The thermal resistibility is exhibited by glass transition temperature (Tg). Generally, higher glass transition temperature exhibits higher thermal resistibility of materials. Thus, development of halogen-free copper clad laminate (CCL) materials with high glass transition temperature is important to meet the requirement of halogen-free substrate materials and lead-free manufacturing processes.
Electronic end products with light weight, a thin profile, small volume, high computation speed and wireless ability are desirable. However, with reduced volume and increased computation speed, a great quantity of heat is produced. The reliability and lifetime of such products is reduced due to the overheating of integrated circuit elements as the heat gradually accumulates. Thus, achieving effective heat dissipation to maintain a stable system has become increasingly important. The main cause of damage or loss of function of electronic devices is high temperature rather than vibration, humidity or dust. Thus, the development of substrate materials with high thermal conductivity is desirable in the thermal management industry.
In a conventional halogen-free environmentally safe material composition, a phosphorus-containing flame retardant is substituted for the original halogen-containing flame retardant. However, while a phosphorus-containing flame retardant is utilized, inorganic powder must also be added to pass the UL-94V0 test. The inorganic powder may comprise hydroxides, for example silicon dioxide or aluminum hydroxide. However, while silicon dioxide is added, the hardness of the formed halogen-free substrate is increased. This is un-favorable because it makes it difficult to drill through the material during the later production phase. When aluminum hydroxide is added, the substrate liberates moisture at low temperature during heating processes. This makes it hard to pass the pressure cooker test (PCT). Currently, the glass transition temperature (Tg) of halogen-free epoxy resin copper clad laminate (CCL) materials merely achieves about 180° C. (less than 200° C. of materials highly thermal resistibility) measured by TMA.
Currently, BT resin developed in 1982 by Japan's Mitsubishi Gas Chemical Company and Bayer Chemical Company technical guidance is an environmentally safe material that is halogen-free and phosphorus-free with a maximum utilized quantity. BT resin polymerized by bismaleimide (B) and triazine (T) and possesses a high glass transition temperature (Tg) of 255-330° C., low dielectric constant and low dissipation factor. However, the brittleness and water absorption thereof is high. Although rigid BT resin has high thermal resistibility, the tensile strength thereof is low, resulting in poor processability. Also, the water absorption of the polar imide group of BT resin is high. Adding epoxy resins may overcome such drawbacks. However, the thermal resistibility thereof is consequently reduced (the glass transition temperature (Tg) thereof is reduced to 170-210° C.). Currently, the glass transition temperature (Tg) of the commercial BT resin substrate material achieves 210° C. above, for example those developed by Mitsubishi Gas Chemical (Tg of 210° C.) and Sumitomo Bakelite (Tg of 220° C.). Additionally, a BN resin-based substrate material with halogen-free, phosphorus-free and high glass transition temperature (Tg) is developed by Mitsui Chemical, with a glass transition temperature (Tg) of 300° C. (measured by DMA). However, adding aluminum oxide is also required to achieve UL-94 V0 test, for example US 2006/0084787A1 "Novel cyanate ester compound, flame-retardant resin composition, and cured product thereof" and US 2008/02621397A1 "Flame retardant crosslink agent and epoxy resin compositions free of halogen and phosphorous".
A thermally cured bismaleimide (BMI) with high glass transition temperature (Tg) is popular. Although rigid BMI has highly thermal resistibility, the tensile strength thereof is low, resulting in poor processability. Some BMI modification methods have been addressed during the last 20 years. Although adding diamine can improve the mechanical properties and adhesion of BMI, the cost and processability thereof cannot meet the market requirements.

Modified bismaleimide resins, preparation method thereof and compositions comprising the same

Abstract: In Formula (I) or (II), Q is —CH2—, —C(CH3)2—, —O—, —S—, —SO2— or null, R is —(CH2)2—, —(CH2)6—, —(CH2)8—, —(CH2)12—, —CH2—C(CH3)2—CH2—CH(CH3)—CH2—CH2—,

Abstract: 10<n<500, and x+y=n. The invention also provides a method for preparing a modified bismaleimide resin and a composition including the modified bismaleimide resin.

Industrial Technology Research Institute


An image stabilization apparatus includes an image stabilization unit that compensates image blurring by moving a compensation member, a first shake detection unit that detects an angular velocity of the shake, a second shake detection unit that detects shake by a different method, an orientation detection unit that detects an inclination status of an optical apparatus, a calculation unit that calculates a compensation value from signals of the first and second shake detection units, and an output unit that compensates the output of the first shake detection unit using the compensation value, with the calculation unit performing weighting on the compensation value of a drive axis of an image stabilization mechanism, based on a correlation between the first signal and the second signal.

Field of the Invention
The present invention relates to image stabilization technology for compensating image blurring (for preventing image degradation) due to shake of an apparatus such as camera shake.
Description of the Related Art
Cameras provided with an image stabilization apparatus (consisting of an image stabilization unit, a driver, a shake detection unit, etc.) that prevents image blurring due to camera shake or the like are currently available, and factors inducing the photographer to make a photographic error have mostly been eliminated.
Here, an image stabilization apparatus that prevents image blurring will be briefly described. Camera shake due to the photographer is usually vibration having a frequency of 1 Hz to 10 Hz.
In order to enable photographs without image blurring to be taken even when camera shake occurs, vibration of the camera due to camera shake has to be detected and a lens for image blurring compensation (hereinafter, compensation lens) has to be displaced according to the detected value.
However, with photography at close range (photography at high magnification), image degradation due to so-called parallel shake that occurs in a direction parallel to or perpendicular to the optical axis of the camera and is undetectable with only a gyroscope also cannot be disregarded. Parallel shake needs to be actively detected and compensated under conditions where, for example, images are captured within 20 cm or so of the subject such as with macro photography, or the focal length of the photographic optical system is extremely long (e.g., 400 mm) despite the subject being positioned at a distance of one meter or so.
With technology disclosed in Japanese Patent Laid-Open No. 7-225405, there is a problem in that the output of the accelerometer tends to be affected by disturbance noise and changes in the environment such as temperature change, and these destabilizing factors are further magnified by performing second order integration, making it difficult to compensate parallel shake with high accuracy.
In Japanese Patent Laid-Open No. 2010-25962, destabilizing factors of the accelerometer such as the above can be mitigated by only deriving the rotation center for frequency bands that tend not to be affected by disturbance. In Japanese Patent Laid-Open No. 2010-25961, technology is disclosed for calculating compensation values up until the time when the image capture operation on the image stabilization target is started, and performing parallel shake compensation during image capture using the compensation values.
However, with a method of performing parallel shake compensation using the rotation radius of angular shake, the rotation radius needs to be correctly derived, and the following issue arises.
That is, although the detection accuracy of the various sensors is important in the case of using an accelerometer and a gyroscope to compute the rotation radius, computation of the rotation radius is not correctly derived in the case where sensor noise exerts a significant influence, and a suitable parallel shake compensation effect is not obtained. Particularly in the case where the proportion of noise amount in the accelerometer output is large, there is concern that the rotation radius will be misestimated, resulting in a large amount of parallel shake compensation, and deterioration in image stabilization performance due to overcompensation.
Because the amount of noise is generally constant regardless of the magnitude of acceleration, in the case where there is significant parallel shake, that is, in the case of a high acceleration output value, the noise exerts little influence on the rotation radius estimation, and the amount of parallel shake compensation can be correctly derived.
However, in the case where there is very little parallel shake, that is, in the case where an acceleration output value is small, the noise exerts a significant influence on the rotation radius estimation, making it difficult to correctly derive the parallel shake compensation amount. In other words, differences in the amount of camera shake due to the shooting posture or the like will give rise to differences in the detection accuracy of parallel shake, that is, differences in the image stabilization effect.
Also, when using a gyroscope and an accelerometer to compute the rotation radius, the following problems arise when attempting to derive the rotation radius and perform parallel shake compensation in the case where the correlation between the angular velocity signal and the acceleration signal is low. That is, because parallel shake is misdetected since the correlation between the output of the gyroscope and the output of the accelerometer is low, image stabilization performance may be adversely affected.
Furthermore, the correlation relationship may differ greatly depending on the orientation of the camera. For example, since roll angular velocity cannot be detected in the case where a pitch and yaw dual-axis gyroscope is provided, when the roll rotation exerts a significant influence, not only is it impossible to perform suitable parallel shake compensation but controllability deteriorates due to overcompensation.
Also, the drive axis that tends to be affected by roll compensation changes depending on the inclination status (shooting orientation) of the camera (e.g., parallel shake due to the influence of the roll angular velocity tends to occur on the yaw axis in the case of a normal status and on the pitch axis in the case of a vertical status).

Image stabilization apparatus, control method thereof, optical apparatus and image capturing apparatus


Provided herein are novel anti-CD28×anti-B7H3 (also referred to as “αCD28×αB7H3”) heterodimeric bispecific antibodies and methods of using such antibodies for the treatment of cancers. Subject αCD28×αB7H3 antibodies are capable of agonistically binding to CD28 costimulatory molecules on T cells and targeting to B7H3 on tumor cells. Thus, such antibodies selectively enhance anti-tumor activity at tumor sites while minimizing peripheral toxicity. The subject antibodies provided herein are particularly useful for enhancing anti-tumor activity when used in combination with other anti-cancer therapies.

The natural immune response against tumor dispatches immune effector cells such as natural killer (NK) cells and T cells to attack and destroy tumor cells. Tumor infiltrating lymphocytes (TILs) often express multiple immune checkpoint receptors (e.g., PD-1, CTLA-4) and costimulatory receptors (e.g., ICOS, 4-1BB, OX40, GITR, and CD28). TILs lose their cytotoxic ability over time due to upregulation of inhibitory immune checkpoints. While checkpoint blockade has demonstrated increased clinical response rates relative to other treatment options, many patients still fail to achieve a response to checkpoint blockade. Engagement of costimulatory receptors on TILs could provide a positive signal capable of overcoming negative signals of immune checkpoints. Preclinical and clinical studies of agonistic costimulatory receptor antibodies have indeed demonstrated that agonism of costimulatory receptors can result in impressive anti-tumor responses, activating T cells to attack tumor cells.
It is also important for cancer therapy to enhance anti-tumor activity by specifically destroying tumor cells while minimizing peripheral toxicity. In this context, it is crucial that only T cells in the presence of the target tumor cells are provided a costimulatory signal. However, agonism of costimulatory receptors with monospecific full-length antibodies is likely nondiscriminatory with regards to TILs vs. peripheral T cells vs. autoantigen-reactive T cells that contribute to autoimmune toxicities. For instance, urelumab, a monospecific, nondiscriminatory, pan-4-1BB agonist antibody, exhibited significant liver toxicity in early phase clinical trials (Segal et al., 2016). Thus, there remains a need for novel immune response enhancing compositions for the treatment of cancers.


A computer-readable recording medium that stores therein a web application testing program causing a computer to execute receiving a request including an input value to be given to web application software installed in a web server; executing the web application software by giving the input value to the web application software; obtaining test information to be used in a test of an output item that is obtained by executing the web application software; generating a response to the request, the response in which the test information is embedded in association with the output item; and transmitting the response to a computer that executes the test of the output item.

1. Field of the Invention
The present invention relates to a technology of an automatic test of web application software conducted in developing a web application system.
2. Description of the Related Art
Conventionally, a test on web application software has been carried out by such a method that a tester visually checks output items while operating a web browser, or writes a testing program and checks output response to an input request in the program.
In the method by such visual check, the tester writes down processes to execute, input values, and expected values in a test specification, and manually enters the input values one by one according to the test specification to execute the processes. The tester determines on whether the test is successful or unsuccessful by visually comparing an output result displayed on a screen with an expected value written in the test specification. Usually, the test specification includes no description of a place on the screen where the output result is displayed. The tester, therefore, specifies the place of result display by his or her own judgment.
Meanwhile, a method combining the techniques disclosed in Jakarta Cactus, [online] searched on Oct. 10, 2006, Internet <URL: http://jakarta.apache.org/cactus>) and Httpunit, [online] searched Oct. 10, 2006, Internet <URL: http://httpunit.sourceforge.net/>) has been widely known as a method using a testing program. According to this method, a tester makes a hyper text transfer protocol (HTTP) request following rules specified at each tool, and sends the request to a web server provided with web application software. The web server sends an HTTP response, which is a result of processing by the web application software, back to the tester that then determines on whether the test is successful or unsuccessful by analyzing the HTTP response in the testing program.
This method using the testing program has an advantage that the same tests can be automatically conducted once the testing program has been written. In carrying out a regression test, where a test once conducted is conducted again, a method in which a the test is automatically carried out at re-execution in such a way that an HTTP response received at the first test is recorded in a log format and an HTTP response obtained at the retest is checked with the recorded log.
Although the above method by the visual check makes writing of a test specification relatively easy, the method invites a risk of overlooking a difference between an output result and an expected value when they do not match because of dependency on manual operation. For example, the tester may have a difficulty in quickly finding the location of the output result on the screen and spend much time to identify the location, and may even fail to recognize the actual output place of the result.
Besides, when the method by the visual check is employed for a regression test requiring repetition of the same tests, greater manpower is required for each execution of the test. This leads to less efficiency and longer period of the test.
In the above method using a testing program, identifying the position of appearance of an output item, which is a test subject, on an HTTP response is even more difficult than the case of the method by the visual check.
If position information on an output item is written precisely in a testing program to facilitate visual check, a small design change results in a necessity of rewriting the testing program, thereby increasing costs in modification of a specification.
When a bug is found in a testing program itself, what matters is the reliability of the test. At present, however, no means for proving a test to be bug-free has been suggested.
In addition, the above method of automatic re-execution of a test through log recording, which is employed for a regression test, etc., cannot be achieved completely automatically, unless an HTTP response at the first test and that at the retest match exactly, except the header.
For example, when web application software includes an output item changing its contents at every test, such as "reception date", a change in the item contents causes inconsistency between a response at a retest and a response log from the first test. As a result, a test result is considered to be unsuccessful.

Method and apparatus for testing web application, and computer product


Solvents for salt-gradient anion-exchange separation of nucleic acids, especially double-stranded DNA and especially by liquid chromatography, are improved by replacing NaCl as the eluting salt with any of a wide range of alkyl ammonium salts and can be used to elute nucleic acids in strict order of increasing length, with reduced sensitivity to elution temperature and salt concentration. Anion-exchange chromatography with these solvents is well suited for identification of DNA fragments on the basis of size, with greater accuracy, precision, and resolvable size range than often is possible with gel electrophoresis.

1. Field of the Invention
This invention relates to novel solvents for the anion-exchange separation of nucleic acid fragments. These solvents result in the marked improvement of chromatographic methods for the analysis of nucleic acids in molecular biology, analytical biochemistry, clinical chemistry, industrial and environmental microbiology, and molecular genetics.
2. Description of Related Art
A single strand of DNA consists of a chain of deoxyribose-phosphate monomers covalently linked via phosphodiester bonds and also contains a single aromatic heterocyclic "base" covalently attached to each deoxyribose ring. In aqueous solvents of pH greater than about 2, the very hydrophilic sugar-phosphate polymer backbone contributes one negative charge for each phosphodiester plus one or two negative charges for every terminal phosphomonoester. Therefore, DNA is a polyanion; the net negative charge is almost perfectly proportional to chain length. However, the bases are very hydrophobic, so that a single strand has mixed hydrophilic-hydrophobic character. Single-stranded DNA adopts a random-coil conformation which fluctuates constantly and rapidly and has a time-averaged spherical shape. Within the sphere, random hydrophobic aromatic stacking interactions and base pairing hydrogen bonds tend to draw together different parts of the chain, and electrostatic repulsion of the phosphate groups tends to drive apart different parts of the structure. The balance between these opposing tendencies and therefore the average spherical diameter depend on temperature and solvent composition, especially ionic strength.
Most naturally occurring DNA is double-stranded, consisting of two single strands of similar or identical length which interact noncovalently to form a double helix in which the four commonly occurring bases, adenine (A), thymine (T), guanine (G), and cytosine (C), exist in complementary sequences on the two interacting strands, such that each A on one strand is hydrogen-bonded to T on the other strand (and vice versa) and each G on one strand is hydrogen-bonded to a C on the other strand (and vice versa). This base-paired structure sequesters the hydrophobic groups inside the double helix along its axis and away from the solvent; the two helical sugar-phosphate chains spiral down the outside of the double-stranded structure, presenting a hydrophilic, poly-anionic face to the solvent. Two helical groves of different width, "major" and "minor," separate the two sugar-phosphate chains. The grooves are large enough to bind water molecules and solvent cations. The double-helical structure also stiffens double-stranded DNA so that segments less than several hundred base pairs are effectively rigid and linear rather than flexibly coiled into a sphere. On the length scale of many hundreds to thousands of base pairs, double-stranded DNA also is coiled but much more loosely than single-stranded DNA. Recently it has become clear that certain sequences in double-stranded DNA induce curvature in the double helix so that it no longer is linear on the length scale of tens to hundreds of base pairs (reviewed by Hagerman, 1990, Annual Reviews of Biochemistry 59:755-781).
Double-stranded DNA can be reversibly "melted" to yield two chains of single stranded DNA by heating to temperatures in the approximate range of 50.degree.-100.degree. C. G-C base pairs tend to melt at higher temperatures than A-T base pairs because their base pairing interactions are stronger. Solvent composition also affects double-helix stability; adding an organic cosolvent or lowering the salt concentration in an aqueous solvent lowers the T.sub.m (the temperature where half of the DNA has dissociated into single strands) of any DNA, regardless of base composition.
RNA structure resembles but is more complex than DNA structure. The single strand is almost identical to the DNA single strand, differing only in the replacement of deoxyribose by ribose and of thymine by uracil (which still can base pair to adenine). However, double-stranded RNA is rare, although single strands often contain relatively short self-paired double-stranded regions because adjoining base sequences are complementary. RNA has the same polyanionic properties as DNA, but the abundance of single-stranded regions renders it more hydrophobic, and the mixture of single-stranded and double-stranded regions destroys the shape regularity (spherical or linear) seen in single- stranded and double-stranded DNA.
The most common methods for separating different DNA molecules, whether for preparative or for analytical purposes, exploit the strictly length-dependent polyanionic properties and the considerable shape regularity and flexibility of both single-stranded and double-stranded structures. Although most electrophoretic and chromatographic DNA separations depend directly or indirectly on polymer net charge, the near proportionality between charge and polymer length results in size-dependent differences in displacement of different DNA species along the separation axis (commonly expressed as distance in gel electrophoresis, time in capillary electrophoresis, and time or volume in chromatography). Larger molecules migrate more slowly and therefore travel less distance in any given electrophoretic separation, because the gel acts as a sieve to exert viscous drag on charged solute molecules; this drag varies directly with solute size. Most chromatographic separations of DNA entail gradient elution, wherein an eluting solute in the solvent is systematically and usually continuously increased with time of elution and volume of continuously flowing solvent; larger molecules are bound more tightly to the chromatographic resin than smaller molecules are, and therefore require higher concentrations of the chromatographic eluting solute to be displaced from the resin. Under ideal separation conditions electrophoretic migration rate and distance or chromatographic elution time and volume depend monotonically on DNA molecular size and can be used to identify specific DNA fragments according to size. In fully optimized separations, electrophoretic displacement or chromatographic elution time is a linear function of the logarithm of molecular size.
The identification value of a size-dependent nucleic acid separation depends on four performance characteristics: size range, size resolution, precision of movement, and size accuracy. Few separations give linear log size calibration curves over a range of more than one order of magnitude of molecular size. As many analyte systems include DNA species ranging over several orders of size magnitude, several different electrophoretic gels (e.g., employing different gel densities) or chromatographic elutions must be run to characterize the system fully. Size resolution concerns how small a difference in DNA length results in distinguishable electrophoretic bands or chromatographic peaks; high-resolution systems usually access the narrowest size ranges. Faster separations usually sacrifice size resolution. Precision of movement is the most important performance criterion for DNA identification. How reproducibly a particular fragment migrates a given distance or elutes at a given time absolutely determines confidence that a fragment has a particular size and is not a completely different species. Precision limitations of both electrophoretic and chromatographic separations are reduced by frequent running of external molecular size standards in adjacent gel lanes or in a consecutive chromatographic separation and optimally by running internal molecular size standards together with the test sample, taking care that the standards do not interfere with the analyte bands or peaks. Molecular size accuracy refers to how exactly analyte species fall on a smooth calibration curve of migration distance or elution time versus molecular size (or its logarithm). Species which fall off the consensus calibration curve for the majority of size standards or analyte molecules may be assigned incorrect molecular size values, although they still can be correctly and precisely identified in test samples as long as the separation anomaly has been characterized previously with known samples. The major risk of size inaccuracy is mischaracterization of new analytes during research and discovery activities.
The total value of a separation method depends on performance in other ways besides the quality of the size information. Other important analytical properties include analyte quantitation (precision, accuracy, dynamic range, and detection limit), ease of recovery of separated species (for post-separation study such as DNA sequencing), reliability (freedom from interferences, equipment or reagent malfunction, and operator error), speed (time per sample), throughput (samples per hour, day or work week), and cost (in equipment, reagents, and labor, including labor quantity and quality).
In recent years, gel electrophoresis has become the standard method for size dependent nucleic acid separations. Two gel matrices are commonly used: agarose, which is easier to use but which gives lower size resolution, and polyacrylamide, which is harder and more hazardous to use and which gives the best size resolution, up to the maximum possible performance (in sufficiently long gels) of resolving single nucleotide differences, especially for single-stranded DNA. Any given gel density provides no more than about one order of magnitude of practical DNA size range. Size precision is rarely measured or expected; gel or electric field inhomogeneity often results in inconsistent migration among lanes or within a single lane in a slab gel. Species generally are identified by approximate movement relative to other species; and absolute analyte identification is based on nucleic acid probing, most commonly by dot blotting or Southern analysis, which gives a positive signal only if the separated species contains base sequence complementary to a polynucleotide or oligonucleotide of known sequence. Identification by blotting generally is slow, labor-intensive, and relatively unreliable, and often is hazardous because the analytical signal commonly is created by radioactive tags on probes.
Gel electrophoresis is unreliable with respect to double-stranded DNA size accuracy, because the molecular curvature described above can retard electrophoretic migration sufficiently to imply that a molecule is twice as long as it really is (Koo and Crothers, 1988, Proc. Natl Acad. Sci. USA 85:1763-1767; Hagerman, 1985, Biochemistry 24:7033-7037; and Shore et al, 1981, Proc. Natl. Acad. Sci. USA 78:4833-4837). Gel electrophoresis has other performance limitations. Bands are most commonly visualized by staining with ethidium, which shows strong fluorescence enhancement when it binds to double-stranded (but not single-stranded) DNA. Such staining is hazardous because ethidium is a cancer-suspect agent; it is very insensitive to single-stranded DNA; it is unreliable for quantitating electrophoretically separated species, because the reversible dye binding reaction is very sensitive to experimental conditions, and fluorescence requires careful calibration. Gel electrophoresis is labor-intensive and vulnerable to operator variability or error. It is relatively slow (at least several hours per run, including staining or other post-electrophoretic detection) but has acceptable throughput because several tens of samples can be run simultaneously. Recovery of separated species from the gel is slow and labor intensive.
Capillary electrophoresis has recently evolved to provide fast, high-resolution, size-dependent DNA separations which are very sensitive to low amounts (in mass units) of DNA. However, size precision is poor; quantitation of individual species is difficult and insensitive (with respect to DNA concentration, which is more important to molecular biologists and clinical chemists than DNA mass; DNA usually is abundantly obtainable, but often at relatively low concentrations); recovery of separated species in useful quantities is difficult because the mass of DNA processed in each separation is very small.
Liquid chromatography, and high-pressure liquid chromatography (HPLC) in particular, is still maturing as a DNA separation method (reviewed by Thompson, 1986, BioChromatography 1:16-20, 22-32, and 68-80; 1987, BioChromatography 2:4-18). The separation chemistry is independent of separation pressure; the latter variable varies inversely with the particle size of the chromatographic matrix and the time required for a separation. Separations that take many hours and hundreds of ml of solvent when run at atmospheric pressure on large- particle adsorbents can be completed in 3-30 minutes consuming 3-30 ml of solvent, at pressures of 5-10 atmospheres on 2-10 .mu.m--diameter particles. Quantitative sensitivity is inversely proportional to separation volume, and HPLC is a highly automated procedure which makes little demands on labor quality or quantity. Liquid chromatography normally detects DNA via its high ultraviolet (UV) absorbance at a wavelength of maximum absorbance (.lambda..sub.max) near 260 nm. HPLC is so automated that a single computer-controlled instrument can run the separation, measure eluted absorbance as a function of elution time, analyze the resulting elution profile to quantitate the absorbance in each peak (corresponding to a different DNA species), identify each peak in terms of elution time and even (by comparison to a calibration curve stored in the computer) molecular size, and collect each peak in a separate container for further analysis. The extreme sensitivity of HPLC UV absorbance detectors gives confident quantitation of peaks no higher than 10.sup.-4 absorbance units, containing approximately 10.sup.-10 g of nucleic acid in less than 0.1 ml of chromatographic solvent. Spectrophotometrically monitored HPLC has a lower DNA detection limit for double-stranded DNA than ethidium-stained gel electrophoresis. The broad dynamic range of HPLC UV absorbance detectors, measuring absorbances up to about 1 absorbance unit, allows HPLC to quantitate DNA ranging over 4 orders of magnitude in concentration, with none of the calibration difficulty of fluorescence measurements.
Two major liquid chromatographic separation chemistries are used for DNA: anion exchange and ion-paired reverse-phase. In anion exchange, the solid chromatographic matrix contains on its surface abundant fixed positive charges which bind the DNA polyanion with a strength related directly to DNA length. As the concentration of an eluting salt is increased, usually continuously with elution time and the volume of solvent passed through a cylindrical column of the densely packed matrix, DNA fragments are eluted in approximate order of increasing size, because dissolved salt weakens the binding of polyanion to matrix. In ion-paired reverse-phase separations, the solid chromatographic matrix contains on its surface abundant fixed hydrophobic groups, and the solvent contains a hydrophobic tetraalkylammonium or trialkylammonium chloride, bromide, or acetate salt. The alkylammonium cations bind weakly to the DNA polyanion to render it approximately electrically neutral and hydrophobic, and the hydrophobic DNA-alkylammonium complex binds to the hydrophobic matrix. As the concentration of a low-polarity organic cosolvent in the aqueous solvent is increased, usually continuously, over elution time, the hydrophobic interactions between DNA and matrix is weakened. Longer DNA molecules bind more tightly to the matrix than small ones, so that elution order again approximately parallels molecular size; larger DNA molecules require higher organic cosolvent concentrations to be eluted.
Despite the previously described advantages of HPLC as a reliable, economical, sensitive, quantitative method of analyzing DNA, neither separation chemistry is optimal with respect to size resolution, range, precision, or accuracy. Ion-paired reverse-phase separations tend to be slow (requiring several hours), often result in relatively low recoveries of eluted fragments, and give occasional inversions in retention time as a function of molecular size, jeopardizing their value for size-accurate identification (Erikson et al, 1986, J. Chromatography 359:265-274). The aqueous solvents used for these separations contain relatively low (10.sup.-3 -10.sup.-1 M) concentrations of trialkylammonium (e.g., triethylammonium) or tetraalkylammonium (e.g., tetrabutylammonium) salts and vary the concentration of an eluting organic cosolvent such as acetonitrile over the range of 5-50%.
Prior to the present invention, anion-exchange HPLC separation of double-stranded DNA on a variety of different ion-exchange solids has suffered from occasional to frequent inversions in retention time as a function of molecular size, preventing its use for size-accurate fragment identification (Kato et al, 1983, J. Chromatog. 265:342-346; Merion et al., 1988, BioTechniques 6:246-251; Kato et al., 1989, J. Chromatog. 478:264-268; Maa et al, 1990, J. Chromatog. 508:61-73; Muller, 1986, Eur. J. Biochem. 155:203-212; Hecker et al. 1985, J. Chromatog. 326:251-261; and Westman et al., 1987, Anal. Biochem. 166: 158-171). In almost every case, it has been remarked that the DNA fragments most likely to have retention times longer than predicted on the basis of molecular size also have abnormally high AT content. However, no remedy was proposed or demonstrated for this effect and only one theory, curvature of A-T rich DNA, has been suggested to explain it (Hecker et al, supra). In almost every case, the eluting salt was NaCl, generally varied in the concentration range of 0.3-1.2M. The other alkali metal chloride salts have been tried without evidence of improved performance over NaCl, and some eluting salt anions such as acetate, trichloroacetate, chlorate, and sulfate, gave greatly reduced fragment resolution or no separation at all (Westman et al. and Hecker et al., supra).
It generally has been observed that the salt gradient must be rendered increasingly shallow to resolve fragments of increasing size, up to the point that for one anion- exchange solid, very little size resolution occurred above 500 base pairs (Westman et al., supra). It has been suggested that this phenomenon occurs because DNA elution is controlled by salt activity rather than concentration (Muller, supra). Salts, including NaCl, show a drop in activity coefficient as salt concentration is increased in the 0.1M range. This drop renders salt activity less than proportional to salt concentration, increasing the salt concentration rise needed to obtain a given activity rise and therefore reducing the salt concentration sensitivity of retention time. However, in the 0.5-1.0M salt concentration range, activity coefficient becomes increasingly salt concentration-independent, rendering the salt activity more strongly salt concentration-dependent and therefore increasing the salt concentration-sensitivity of retention time.
In only one case (Muller, supra). has the effect of temperature on anion-exchange HPLC retention time been observed. Increasing temperature increased the strength of DNA binding to the anion-exchange solid, but no effort was made to quantitate the phenomenon or relate it to technical requirements for retention-time precision. Retention-time precision has not been a concern in the prior art.
The preceding review has focused on the HPLC of double-stranded DNA, expected to be simpler than that of single-stranded DNA and RNA, because partly- or completely single-stranded nucleic acid exposes bases to the solvent and the chromatographic matrix and therefore should show strongly sequence- and composition-dependent retention times. However, these complicating interactions can be reduced by including organic cosolvents in the eluting solvent, by choosing a chromatographic matrix which interacts minimally with the bases, or by operating at such a high pH, generally above 10, that some of the bases become anionic. When the bases bear negative charges, base-stacking and hydrogen bonding interactions among them are weakened, and the nucleic acid resembles a purely random coil, the radius and net charge of which are directly related to polymer length. Organic cosolvents promote this behavioral simplification in two ways, by weakening base-stacking and hydrogen bonding and by weakening base-matrix interactions.
Given the observation that high A-T content tends to cause double-stranded DNA to bind to anion-exchange solids more tightly than expected simply on the basis of molecular size, the following question arises: could some simple change in eluting conditions, such as temperature or solvent composition, ablate whatever structural difference between A-T-rich and G-C-rich DNA is responsible for the phenomenon?
Melchior and von Hippel, 1973, Proc. Natl. Acad. Sci. USA 70 :292-302, showed that tetraalkylammonium halide salts (especially tetramethylammonium chloride and tetraethyl-ammonium chloride) and at least one trialkylammonium salt (triethylammonium chloride) greatly reduced and could even eliminate the differences in melting behavior between G-C-rich and A-T-rich DNA. However, tetramethylammonium ion and tetraethylammonium ion had dramatically opposite effects on double-stranded DNA stability; the former increased T.sub.m whereas the latter decreased T.sub.m. These effects were most evident at very high (greater than 2M) salt concentrations, one to two orders of magnitude higher than the concentration ranges in which these salts are used in ion-paired reverse-phase HPLC of nucleic acids. Shapiro et al., 1969, Biochemistry 9:3219-3232, showed that polylysine preferentially binds to and precipitates A-T-rich DNA and that adding tetraalkylammonium salts at very high concentration destroys and even reverses this preference.
The second phenomenon implies that the tetraalkylammonium ions also bind preferentially to A-T-rich DNA; this inference explains the results of Melchior and von Hippel as well. Shapiro et al., 1969, Biochemistry 9:3233-3241, showed directly that several tetraalkylammonium ions bind more tightly to A-T-rich than to G-C-rich DNA and suggested that this phenomenon, not seen for the alkali metal cations, arose from the tightness of steric fit of the tetraalkylammonium ions in the double helix major groove. Orosz and Wetmur, 1977, Biopolymers 16: 1183-1199, explored the steric interpretation by probing the effects on double- stranded DNA stability of a variety of tetraalkylammonium ions containing different combinations of methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. Increasing alkyl group size tended to render the cation more helix-destabilizing and, for alkyl groups larger than ethyl, tended to reduce the ability to stabilize A-T-rich regions preferentially.
The question raised by these indications of preferential binding of tetraalkylammonium and trialkylammonium salts to A-T-rich regions of double-stranded DNA is whether such a preference could reduce the tendency of A-T-rich double-stranded DNA to bind especially tightly to anion-exchange solids. If alkylammonium cations could operate in this fashion in concentration range, presumably near 1M where they might elute DNA from anion-exchange matrices, then they might render anion-exchange HPLC an accurate method of estimating DNA fragment size from chromatographic retention time. Furthermore, the observation that double-stranded DNA affinity for at least one anion-exchange solid increases with increasing temperatures (Muller, supra) suggests that interactions of the eluting cation with DNA and of the eluting anion with anion-exchange solid may control the temperature dependence. If the DNA-anion-exchange-solid interaction alone controlled the temperature dependence, affinity would fall as the temperature is increased. Therefore, alkylammonium eluting salts might change the temperature sensitivity of chromatographic retention time. The lower this temperature sensitivity, the easier it would be to attain high retention-time precision, improving the ability of HPLC to identify DNA fragments solely on the basis of retention time.
Although the choice of eluting salt cation has the best chance of influencing the size accuracy of anion-exchange HPLC of double-stranded DNA, the choice of salt anion has strong effects, positive or negative, on the quality of the separation. As noted above, some anions reduce peak resolution on at least some anion-exchange solids. Anions have profound effects on double-stranded DNA stability (Robinson and Grant, 1966, J. Biol. Chem. 241:4030-4042); salt anions which tend to melt DNA might increase retention-time sensitivity to DNA A-T content or sequence. Salt anion interaction with the anion-exchange solid will affect retention-time temperature dependence, because it contributes to the total enthalpy change of the anion-exchange process. In this regard, anions which bind weakly to the anion- exchange solid are preferred because they are likely to contribute the smallest enthalpy changes. Finally, the chloride anion, almost universally used in the eluting buffers for DNA anion-exchange chromatography, is well known to promote the corrosion of stainless steel, commonly used in HPLC pumps, fittings, columns, and tubing. Almost any other buffer anion would be preferred in the interest of improving HPLC hardware durability and minimizing contamination of columns and analytes with Fe(III).
The combination of cation and anion in the eluting salt can affect HPLC pump durability and maintenance in still another way. Small solvent leaks deposit elution solvent on moving parts. After the water evaporates, the buffer salts crystallize to form abrasive solids which scratch the pistons and seals. The especially high eluting salt concentrations of anion-exchange chromatography of DNA are particularly damaging to HPLC pumps and valves. However, eluting salts differ in crystalline hardness and shape and therefore in abrasive potential; NaCl is particularly abrasive whereas salts of alkylammonium cations and of carboxylate anions should form softer crystals. Some salts, like those between dialkylamines or trialkylamines and short-chain aliphatic carboxylic acids (for example, formic and acetic acids) have the additional advantage of being volatile, because the component acids and bases are volatile (tetraalkylammonium salts do not share this property). Volatile salts are less likely to abrade moving parts and also are easier to remove from recovered samples of chromatographed DNA if they interfere with post-HPLC processing.
Clearly, optimizing solvent composition for the anion- exchange HPLC of DNA involves multiple criteria, some of which may be mutually incompatible. It is equally clear that the conventional eluting salt, NaCl, is suboptimal for multiple reasons: (1) retention-time sensitivity to DNA A-T content, which reduces size accuracy, (2) a very high retention-time temperature sensitivity which reduces size precision, (3) an escalating retention-time sensitivity to salt concentration as DNA fragment size increases, resulting in a reduced practical size range, and (4) a propensity to damage HPLC hardware chemically and physically. The present invention provides improved HPLC solvents which address all of these concerns.

Precision and accuracy of anion-exchange separation of nucleic acids


Systems and methods for reducing latency on a remotely-booted information handling system are disclosed. A method may include remotely booting an information handling system having a local storage resource. The method may also include establishing, at the start of a session, an encryption key for the local storage resource for use during the session. Additionally, the method may include using the encryption key to encrypt data written to the local storage resource during the session. The method may further include permanently disabling access to the encrypted data written to the local storage resource at the end of the session.

As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Increasingly, information handling systems are deployed in architectures by which information handling systems boot their respective operating systems remotely from storage resources via a network. Often, these architectures are employed for numerous reasons, including without limitation: (1) increased concern with the security of data-at-rest in information handling systems, particularly in portable computing devices (e.g., notebooks, laptops, and handhelds); and (2) simplified operating system management. However, an information handling system that is remotely-booted and only allows access to storage resources via a network connection may have a disadvantage when attempting to access frequently-accessed temporary data (e.g., virtual memory page files, buffers, etc.), as data access over a network typically has a higher latency than data access via a local storage resource.

System and method for reducing latency on remotely-booted information handling systems


A normally white (NW) twisted nematic liquid crystal display (LCD) outputs improved viewing characteristics which are defined by high contrast ratios and/or reduced inversion. The display includes a pair of negative tilted retarders (#2 and #6) located on one side of the liquid crystal layer (#10), each of the tilted retarders including a tilt or incline angle which varies throughout the thickness of the layer. Additionally, one or two negative uniaxial or biaxial retarders (#4 and #7) are provided on the same side of the liquid crystal layer as the tilted retarders. As a result of the particular orientations, alignments, and retardation values described in the different embodiments, the display exhibits improved contrast and reduced inversion.

Informational data in liquid crystal displays (LCDs) is presented in the form of a matrix array of rows and columns of numerals or characters (e.g. pixels) which are generated by a number of segmented pixel electrodes arranged in a matrix pattern. The segments are connected by individual leads to driving electronics which apply a voltage to the appropriate combination of segments and adjacent liquid crystal (LC) material in order to display the desired data and/or information by controlling the light transmitted through the liquid crystal (LC) material.
Contrast ratio (CR) is one of the most important attributes considered in determining the quality of both normally white (NW) and normally black (NB) LCDs. The contrast ratio (CR) in a normally white display is determined in low ambient conditions by dividing the "off-state" light transmission (high intensity white light) by the "on-state" or darkened transmitted intensity. For example, if the "off-state" transmission is 200 fL at a particular viewing angle and the "on-state" transmission is 5 fL at the same viewing angle, then the display's contrast ratio at that particular viewing angle is 40 (or 40:1) for the particular driving voltages utilized.
Accordingly, in normally white LCDs, a significant factor adversely limiting contrast ratio is the amount of light which leaks through the display in the darkened or "on-state." In a similar manner, in normally black displays, a significant factor limiting the contrast ratio achievable is the amount of light which leaks through the display in the darkened or "off-state." The higher and more uniform the contrast ratio of a particular display over a wide range of viewing angles, the better the LCD in most applications.
Normally black (NB) twisted nematic displays typically have better contrast ratio contour curves or characteristics than do their counterpart NW displays (i.e. the NB image can often be seen better at large or wide viewing angles). However, NB displays are optically different than NW displays and are much more difficult to manufacture due to their high dependence on the cell gap or thickness "d" of the liquid crystal layer as well as on the temperature of the liquid crystal (LC) material itself. Accordingly, a long-felt need in the art has been the ability to construct a normally white (NW) display with high contrast ratios over a large range of viewing angles, rather than having to resort to the more difficult and expensive to manufacture NB displays in order to achieve these characteristics.
What is often needed in NW LCDs is an optical compensating or retarding element(s), i.e. retardation film(s), which introduces a phase delay that restores the original polarization state of the light, thus allowing the light to be substantially blocked by the output polarizer (analyzer) in the "on-state." Optical compensating elements or retarders are known in the art and are disclosed, for example, in U.S. Pat. Nos. 5,184,236; 5,189,538; 5,406,396; 4,889,412; 5,344,916; 5,196,953; 5,138,474; and 5,071,997.
The disclosures of Ser. No. 08/559,275; and U.S. Pat. Nos. 5,570,214 and 5,576,861 (all incorporated herein by reference) in their respective "Background" sections illustrate and discuss contrast ratio, and driving voltage versus intensity (fL), graphs of prior art NW displays which are less than desirable. Prior art NW LCD viewing characteristics are problematic in that, for example, their contrast ratios are limited horizontally and/or vertically (and are often non-symmetric), and their gray level performance lacks consistency.
Gray level performance, and the corresponding amount of inversion, are also important in determining the quality of an LCD. Conventional active matrix liquid crystal displays (AMLCDs) typically utilize anywhere from about 8 to 64 different driving voltages. These different driving voltages are generally referred to as "gray level" voltages. The intensity of light transmitted through the pixel(s) or display depends upon the driving voltage utilized. Accordingly, conventional gray level voltages are used to generate dissimilar shades of color so as to create different colors and images when, for example, the shades are mixed with one another.
Preferably, the higher the driving voltage in a normally white display, the lower the intensity (fL) of light transmitted therethrough. The opposite is true in NB displays. Thus, by utilizing multiple gray level driving voltages, one can manipulate either a NW or NB LCD to emit desired intensities and shades of light/color. A gray level voltage V.sub.ON is generally known as any driving voltage greater than V.sub.th (threshold voltage) up to about 3.0 to 6.5 volts, although gray level voltages may be as low as 2.0 in certain applications.
Gray level intensity in an LCD is dependent upon the display's driving voltage. It is desirable in NW displays to have an intensity versus driving voltage curve for as many viewing angles as possible wherein the intensity of light emitted from the display or pixel continually and monotonically decreases as the driving voltage increases. In other words, it is desirable to have gray level performance in a NW pixel such that the transmission intensity (fL) at 6.0 volts is less than that at 5.0 volts, which is in turn less than that at 4.0 volts, which is less than that at 3.0 volts, which is in turn less than that at 2.0 volts, etc. Such desired gray level curves across a wide range of view allows the intensity of light reaching viewers at different viewing angles to be easily and consistently controlled. It is also desirable that all such curves have substantially the same slope.
U.S. Pat. Nos. 5,576,861 and 5,570,214 discuss, in their respective "Background" sections, prior art NW LCDs with inversion problems (e.g. inversion humps). As discussed therein, inversion humps are generally undesirable. A theoretically perfect driving voltage versus intensity (fL) curve for an NW display would have a decreased intensity (fL) for each increase in gray level driving voltage at all viewing angles. In contrast to this, inversion humps represent increase(s) in intensity of radiation transmitted or emitted from the LCD or light valve (LV) for a corresponding increase in gray level driving voltage. Accordingly, it would satisfy a long-felt need in the art if a normally white TN liquid crystal display could be provided with no or little inversion and improved contrast ratios over a wide range of viewing angles.
U.S. Pat. No. 5,583,679 discloses an LCD including an optical compensating sheet that includes a discotic structure and negative birefringence, with the discotic structure unit having an inclined plane. Unfortunately, the contrast ratios and inversion characteristics resulting from displays of the '679 patent have been found by the instant inventors to be less than desirable. Certain embodiments of the instant invention described herein exhibit surprisingly improved results with respect to contrast ratio and/or inversion as compared to the '679 patent.
Commonly owned U.S. Pat. No. 5,570,214 discloses a normally white twisted nematic LCD including retardation films on opposite sides of the LC cell. While LCDs manufactured in accordance with the teachings of the '214 patent achieved excellent viewing characteristics, it has been found by the instant inventors that such viewing characteristics can be improved upon.
Likewise, commonly owned U.S. Pat. No. 5,594,568 discloses a normally white LCD including a pair of retardation films on one side of the LC cell. Again, while displays manufactured in accordance with the teachings of the '568 patent achieve excellent results, it has been found by the instant inventors that there is room for improvement with respect to contrast ratio and inversion.
In the prior art, some have been able to separately and independently reduce inversion or improve contrast in given viewing zones, but typically if contrast is improved upon, then inversion characteristics suffer. To date, those in the art have been unable to improve both contrast and inversion in the same viewing area of a display as taught below in accordance with the instant claimed invention.
It is apparent from the above that there exists a need in the art for a normally white TN liquid crystal display wherein the viewing zone of the display has high contrast ratios and/or little or no inversion over a wide range of viewing angles. Furthermore, there exists a need in the art for improved contrast and reduced inversion in the same viewing zone (e.g. in the upper vertical viewing zone principally utilized by pilots of aircraft in avionic applications).
The term "rear" when used herein but only as it is used to describe substrates, polarizers, electrodes, buffing films or zones, and orientation films means that the described element is on the backlight side of the liquid crystal material, or in other words, on the side of the LC material opposite the viewer.
The term "front" when used herein but only as it is used to describe substrates, polarizers, electrodes, buffing films or zones and orientation films means that the described element is located on the viewer side of the liquid crystal material.
Unless otherwise specified, the actual LCDs and light valves made and/or tested herein included a liquid crystal material with a birefringent value (.DELTA.n) of 0.0854 at room temperature, Model No. ZLI-4718 obtained from Merck.
Unless otherwise specified, the term "retardation value" as used herein for uniaxial retarders means "d.multidot..DELTA.n" of the retardation film or plate, where "d" is the film or plate thickness and ".DELTA.n" is the film birefringence (i.e. difference in indices of refraction).
The term "interior" when used herein to describe a surface or side of an element (or an element itself), means that closest to the liquid crystal material.
The term "light valve" as used herein means a liquid crystal display including a rear linear polarizer, a rear transparent substrate, a rear continuous pixel electrode, a rear orientation film, an LC layer, a front orientation film, a front continuous pixel electrode, a front substrate, and a front linear polarizer (i.e. without the presence of color filters and active matrix driving circuitry such as TFTs). Such a light valve may also include retardation film(s) disposed on either side of the LC layer as described with respect to each example and/or embodiment herein. In other words, a "light valve" (LV) may be referred to as one giant pixel without segmented electrodes.
For all circular contrast ratio graphs herein, "EZContrast" equipment available from Eldim of Caen, France (ID #204F) was used to develop these graphs. This equipment includes a system for measuring Luminance and Contrast versus viewing angle (incident (polar) and azimuth angle), utilizing 14 bits A/D conversion to give luminance measurements from 1/10 to 8,000 cd/m.sup.2, with an accuracy of 3% and a fidelity of 1%. A temperature regulated CCD sensor with a photopic response (and specially designed lenses) are part of this commercially available Eldim system and corresponding software. The measurement device of this Eldim system includes a specially designed large viewing angle lens system having a numerical aperture of 0.86. The Eldim software is Windows.TM. 3.1 based, running on any 486 and above PC, supporting DDE interface with other programs.
Unless otherwise specified, all examples herein were carried out at approximate 25.degree. C.
All measured real data herein, in the Examples, included the non-uniform characteristics of the backlight over a range of angles. Backlights are more intense at normal than at wide angles.

NW twisted nematic LCD with negative tilted retarders on one side of liquid crystal cell