A novel technique for relieving arachidonic acid deficient conditions and maintaining a good fatty acid balance in vivo. Utilizaiton of a DPA-containing material for relieving arachidonic acid deficient conditions and maintaining a good fatty acid balance in vivo; and compositions for relieving arachidonic acid deficient conditions and maintaining a good fatty acid balance in vivo which contain a DPA-containing material in an amount efficacious in relieving arachidonic acid deficient conditions and maintaining a good fatty acid balance in vivo per unit dose.

This application is a 371 of PCT/P00/01355 filed Mar. 6, 2000.
The present invention relates to the use of material containing 4, 7, 10, 13, 16-docosapentaenoic acid (hereinafter, also referred to as xe2x80x9cDPAxe2x80x9d) for relieving arachidonic acid deficient conditions and maintaining a good fatty acid balance in vivo and especially relates to the use of material containing 4, 7, 10, 13, 16-docosapentaenoic acid to prevent the decrease of arachidonic acid levels caused by intake of xcfx893 unsaturated fatty acids.
The two representative families of unsaturated fatty acids are the xcfx893 type and xcfx896 type. Here, (indicates the number of carbon atoms in a fatty acid, counting from the methyl end to the closest double bond. Recently, the ratio of xcfx896 unsaturated fatty acids to xcfx893 type fatty acids has been recognized as important.
Various fatty acids including xcfx896 type fatty acids, such as linoleic acid, dihomo-xcex3-linolenic acid, and arachidonic acid, and xcfx893 type fatty acids, such as xcex1-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid, are each known to take on different biological functions. At the same time, and importantly, these two types of unsaturated fatty acids strongly influence each other in their biological functions. In humans, these unsaturated fatty acids cannot be biologically synthesized in vivo, and both types do not inter-convert. Thus, the ratio of xcfx893 type to xcfx896 unsaturated fatty acids in vivo is expected to reflect the ratio in the source of intake (e.g. food).
Meanwhile, based on a nutrition investigation among the Japanese, the recommended intake ratio of xcfx896 unsaturated fatty acids to xcfx893 unsaturated fatty acids was approximately 4:1, according to the revised 1994 dietary allowance for the Japanese. (Ministry of Health and Welfare, 5th revised edition, Nihonjin no Eiyo no Shoyoryo (Dietary Allowance for the Japanese), 1994, pp. 56-58.)
In addition, the recent eating habits of the Japanese have been influenced by the diet of Western countries, leading to a marked increase in opportunities to have meals centered on meat, and increase in the intake of xcfx896 unsaturated fatty acids in comparison to the xcfx893 type. Consequently, the mortality rate due to arteriosclerosis diseases, such as myocardial infarction and cerebral thrombosis is rapidly increasing. To improve this condition, addition of highly concentrated xcfx893 unsaturated fatty acids, such as 5, 8, 11, 14, 17-eicosapentaenoic acid (hereinafter, also referred to as xe2x80x9cEPAxe2x80x9d) and 4, 7, 10, 13, 16, 19-docosahexaenoic acid (hereinafter, also referred to as xe2x80x9cDHAxe2x80x9d) to nutrient-supplementing food has been developed.
Eicosanoids (prostaglandin, leukotriene, thromboxane, etc.), each exhibiting different physiological functions, are biosynthesized from EPA in the case of xcfx893 unsaturated fatty acids, and from dihomo-xcex3-linolenic acid and arachidonic acid in the case of xcfx896 unsaturated fatty acids. Furthermore, xcfx893 type and xcfx896 unsaturated fatty acids themselves suppress the fatty acid biosynthetic pathway of another type. For example, EPA intake inhibits the xcex946-desaturase controlling the conversion of linoleic acid, the starting fatty acid in the biosynthesis of xcfx896 type fatty acids, to xcex3-linolenic acid, the chain elongation enzyme controlling the conversion of xcex3-linolenic acid to dihomo-xcex3-linolenic acid, and the xcex945-desaturase controlling conversion of dihomo-xcex3-linolenic acid to arachidonic acid. Consequently, the amount of the final product, arachidonic acid (hereinafter, also referred to as xe2x80x9cARAxe2x80x9d), significantly decreases. Intake of ARA-precursor fatty acids (such as, linoleic acid, and xcex3-linolenic acid) is only slightly effective for supplementing this ARA decrease, and direct intake of ARA was said to be necessary.
Furthermore, in recent years, elucidation of the biologically active functions of DHA and its practical use have progressed due to discovery of fish material that contains high concentrations of DHA, such as the orbital fat of tuna, and technological advancement in producing highly purified fatty acids. It has become apparent that the effect of lowering cholesterol levels, anticoagulant effect, and carcinostatic effect are biologically active functions of DHA. In relation to the metabolic system of the brain, it has also become apparent that DHA is effective in improving memory and learning, preventing senile dementia, and treating Alzheimer""s disease. In addition, it has been proven that DHA is an essential fatty acid for the growth of fry. From the above-mentioned reasons, DHA is used in various foods, feedstuffs, and baits. DHA also inhibits the biosynthetic pathway involving xcfx896 unsaturated fatty acids, leading to ARA, and this inhibition is known to be stronger than that by EPA. Thus, decline in ARA levels as a secondary effect due to administration of DHA alone is considered a problem.
Administration of DHA alone is hardly a problem if xcfx893 unsaturated fatty acids are administered only for a limited period to a particular patient as a medicament, or if administration of DHA supplements lowered levels or complete deficiency of xcfx893 unsaturated fatty acids. However, the balance between xcfx896 and xcfx893 type fatty acids must be considered when xcfx893 unsaturated fatty acids are taken to prevent diseases. In the past, direct intake of ARA was necessary to repress the decrease of ARA levels due to intake of xcfx893 unsaturated fatty acids. However, controlling the amount of ARA intake is difficult because ARA is the direct precursor of eicosanoids, such as 2-series prostaglandin and 4-series leukotriene.
ARA deficient conditions are not limited to those caused by xcfx893 unsaturated fatty acid intake. For example, among infants, the aged, patients with adult diseases, and those at risk of adult diseases such as hepatic diseases, the biosynthetic pathway to produce ARA from linoleic acid is weak, and plainly, ARA In vivo tends to be deficient. Under diseased conditions, prostaglandin and its precursor, ARA, are in high demand for central defense and repair mechanisms in vivo. Therefore, ill patients suffer from deficiency of ARA that may contribute to recovery and survival. Regardless of age, inadequate nutrition leads to ARA deficient conditions. Furthermore, ARA is often deficient in individuals whose fat intake is restricted (for example, due to hyperlipidemia, diabetes, obesity, and so on).
Consequently, techniques to improve ARA deficient conditions and to maintain a good fatty acid balance in vivo, and especially techniques that provide safer alternatives to direct intake of ARA in efforts to prevent decrease of ARA levels caused by intake of xcfx893 unsaturated fatty acids were in high demand.
The present invention intends to solve the problems mentioned above and provides a novel technique to improve arachidonic acid deficient conditions and to maintain a good fatty acid balance in vivo, and especially, a novel technique to prevent decrease of arachidonic acid levels caused by intake of xcfx893 unsaturated fatty acids.
Upon intensive research to accomplish the objectives described above, the present inventors found that xcfx896 type docosapentaenoic acid (4, 7, 10, 13, 16-docosapentaenoic acid, hereinafter, also referred to as xe2x80x9cDPAxe2x80x9d) is converted to arachidonic acid (ARA) in vivo under ARA deficient conditions, and especially under ARA deficient conditions caused by intake of xcfx893 unsaturated fatty acids. The inventors also found that the resulting increase in ARA levels can affect the fatty acid balance in vivo leading to maintenance of a good fatty acid balance. The present invention was completed based on these findings.
In one embodiment, the present invention provides a use of a DPA containing material for relieving ARA deficient conditions and maintaining a good fatty acid balance in vivo. In another embodiment, the present invention provides a composition for relieving ARA deficient conditions and maintaining a good fatty acid balance in vivo, the composition containing DPA-containing material in an amount efficacious in relieving ARA deficient conditions and maintaining a good fatty acid balance in vivo, per unit dose.
In another embodiment, the present invention provides a method for relieving ARA deficient conditions and maintaining a good fatty acid balance in vivo in mammals excluding humans, the method comprises administering any one of the compositions mentioned above. A method to relieve ARA deficient conditions and maintain a good fatty acid balance in viva in mammals excluding humans is presented.
Application of the present invention to ARA deficient conditions provides significant increase of ARA levels, and allows maintenance of a good fatty acid balance in vivo, for example in the liver and/or serum.
In another embodiment, the present invention provides a use of a DPA-containing material for preventing decrease of ARA levels caused by intake of xcfx893 unsaturated fatty acids. In a separate embodiment, the present invention provides a composition for preventing decrease of ARA levels caused by intake of xcfx893 unsaturated fatty acids, the composition containing DPA-containing material in an amount efficacious in relieving decrease of arachidonic acid levels, perunit dose.
In any of the use and compositions mentioned above, the DPA-containing material may be any one or more of DPA-containing lipids selected from a group consisting of lower alkyl esters of DPA and glycerol esters containing DPA as component material. This DPA-containing material may be derived from microorganisms. The microorganisms may be selected from a group consisting of genus Thraustochytriurm, genus Schizochytrium, genus Japonochytriur, and genus Ulkenia.
Any of the compositions mentioned above may be food, food additive, medicament, additive for medicament, feed or bait.
In another embodiment, the present invention provides a method for the production of a composition that prevents the decrease of ARA levels caused by intake of xcfx893 unsaturated fatty acids, comprising: determining the average amount of intake of xcfx893 unsaturated fatty acid during a set period by a subject; estimating the decrease of ARA levels in a subject caused by intake of xcfx893 unsaturated fatty acids; and preparing a unit dose of composition that contains DPA-containing material in an amount efficacious in preventing decrease of ARA levels.
In another embodiment the present invention provides a method for producing a composition that prevents the decrease of ARA levels caused by xcfx8903 unsaturated fatty acid intake, comprising; determining the amount of xcfx893 unsaturated fatty acids to be included in a composition per unit dose; estimating the decrease of ARA levels in a subject due to intake of xcfx893 unsaturated fatty acids; and preparing the unit dose composition containing DPA-containing material and xcfx893 unsaturated fatty acid-containing material in amounts efficacious in preventing decrease of ARA levels.
The DPA-containing material and xcfx893 unsaturated fatty acid-containing material may be lipids containing DPA and xcfx893 unsaturated fatty acids. In addition, the total amount of fatty acids in the above-mentioned composition may contain 0.1% or more of DPA; 0.1% or more of DPA and 0.1% or more of 4, 7, 10, 13, 16, 19-docosahexaenoic acid (DHA); and 0.1% or more of DPA, 0.1% or more of DHA, and 20% or less of 5, 8, 11, 14, 17-eicosapentaenoic acid (EPA).
The above-mentioned lipids containing DPA and xcfx893 unsaturated fatty acids may contain as components, one or more compounds selected from a group consisting of lower alkyl esters of DPA, lower alkyl esters of xcfx893 unsaturated fatty acids, as well as glycerol esters containing DPA and/or xcfx893 unsaturated fatty acids.
Especially, the above-mentioned lipids containing DPA and xcfx8903 unsaturated fatty acids may contain as components, either DPA ethyl ester and xcfx893 unsaturated fatty acid ethyl ester, or triglycerides containing DPA and/or xcfx893 unsaturated fatty acids.
In another embodiment, the present invention provides lipids containing ARA, DPA, and DHA, where ARA/DHA (weight ratio) is 0.03xcx9c0.4, DPA/DHA (weight ratio) is 0.07 or greater, and EPA/DHA (weight ratio) is 0.05 or less. Specifically, DPA/DHA (weight ratio) may be 0.07xcx9c5.0.
The above-mentioned lipids may be a mixture of lipids obtained by cultivating one type of microorganism or a mixture of lipids that may be obtained by separately cultivating various microorganisms.
Either of the above-mentioned lipids may contain glycerol esters that include ARA, DPA, and/or DHA as components, specifically it may contain triglycerides that include ARA, DPA, and/or DHA as components.
In another embodiment, this invention provides a nutrient-supplementing food comprising any one of the above-mentioned lipids. This nutrient-supplementing food may be a formula suitable for feeding infants, a formula suitable for feeding premature infants, baby food, food for expectant or nursing mothers, geriatric food, or food for ill patients.
In another embodiment, this invention provides feed for animals comprising any one of the lipids mentioned above.
The possibility that DPA may convert to ARA through retro-conversion has been reported previously (FEBS Letters, 431: 1-6 (1998); Biochim. Biophys. Acta. 137: 420-426 (1967); Biochim. Biophys. Acta. 218: 29-35 (1970); J. Nutrition. 83: 234-238 (1964)). However, these reports only reveal the conversion of DPA to ARA that occurs when DPA is administered to a rat raised on an essential fatty acid-deficient diet such that its ARA levels are excessively decreased in the tissues. Even in administration experiment to normal animals, the report only revealed the conversion of DPA to ARA occurring in the testicles where DPA levels are especially high. The previously reported conversion of DPA to ARA is limited to changes in animals that were raised under special conditions, such as on an essential fatty acid-deficient diet or changes that occurred during a short period within specialized tissues. It was not clarified whether administration of DPA for a long period of time as feed under general nutritional conditions significantly increases the lowered ARA levels in the liver, serum, and such, to maintain a good fatty acid balance. In addition, there had been no indication previously that DPA represses decreased levels of ARA caused by intake of xcfx893 unsaturated fatty acids.
The present invention is described in more detail below.
(Utilization of DPA containing material to relieve ARA deficient conditions and maintain a good fatty acid balance in vivo.)
This invention describes the use of DPA-containing material to increase deficient ARA levels in vivo and to maintain a good fatty acid balance. Compositions having this utility comprise DPA-containing material in an amount effective for relieving ARA deficient conditions and maintaining a good fatty acid balance in vivo, per unit dose.
In this description xe2x80x9cDPA-containing materialxe2x80x9d means material containing DPA in any chemical or physical form appropriate for physiological intake of DPA in vivo. Examples of DPA-containing material besides free DPA are inorganic salts of DPA (for example, non-toxic metal salts including alkali metal salts, such as sodium salt and potassium salt; and alkaline earth metal salts, such as calcium salt and magnesium salt), organic salts (for example, ammonium salt), derivatives other than lipids that contain DPA (for example, an amide of DPA and its alkyl substituted forms), and lipids that contain DPA (also simply referred to as xe2x80x9cDPA-containing lipidsxe2x80x9d). DPA-containing lipid is the preferred DPA-containing material in a sense of its physical stability, bio-absorbability and its main constructive form in vivo.
In this description xe2x80x9clipidxe2x80x9d refers to a material that is soluble in organic solvents, such as in ether, chloroform, and benzene, but insoluble in water, and has an intramolecular chemical bond, represented by, for example, an ester bond, formed between a higher fatty acid. Examples of DPA-containing lipids are lower alkyl esters of DPA and glycerol esters containing DPA as their components.
In this description xe2x80x9clower alkyl esters of DPAxe2x80x9d rid refers to esters formed between DPA and lower alcohols with 1xcx9c6 carbons, preferably 1xcx9c4 carbons, and more preferably 1xcx9c3 carbons. The ethyl ester is especially preferable with regard to bio-acceptability and safety of the alcohol that dissociates upon hydrolysis of the ester bond in vivo. xe2x80x9cGlycerol esters containing DPAxe2x80x9d or xe2x80x9cglycerol esters containing DPA as their componentxe2x80x9d refers to materials where at least one molecule of DPA forms an ester bond per molecule of glycerol. Such examples include monoacylglyceride, diacylglyceride, triacylglyceride, glycerophospholipid, glyceroglycolipid, etc. Considering application to food, triacylglyceride (also simply called xe2x80x9ctriglyceridexe2x80x9d) is preferred from the standpoint of edible forms of fat.
As it is clear to one skilled in the art, DPA-containing lipids are not limited to the examples mentioned above, but also include sphingophospholipids and other phospholipids, sphingoglycolipids and other glycolipids, and any DPA-containing material included in the above definition.
The components per unit dose, and the amount of DPA-containing material included per unit dose for effective relief of ARA deficient conditions and maintenance of a good fatty acid balance in vivo, may be adjusted to suitable levels by one skilled in the art according to the type, sex, age, weight, health condition, or the disease of the subject (humans or other mammals). xe2x80x9cEffective for relieving ARA deficient conditions and maintaining a good fatty acid balance in vivoxe2x80x9d means that the intake of DPA-containing material causes significant increase of ARA levels, which is enough to restore decreased levels of ARA to normal levels and to maintain a normal level of ARA in vivo. The presence or absence of increase in ARA levels in vivo may be measured by any of the known biochemical methods and/or analytical chemistry methods known to one skilled in the art. As a non-limiting example, in order to relieve ARA deficient conditions and to maintain a good fatty acid balance in vivo in adult humans, compositions containing DPA-containing material for a single administration per day should contain 0.0001 mgxcx9c100 g, preferably 0.001 mgxcx9c10 g, and more preferably 0.5 mgxcx9c5 g of free DPA per unit dose.
Utilization of DPA-containing material of this invention and administration of compositions comprising DPA-containing material may exclude the utilization and administration carried out according to medical prescription by a medical doctor in cases where the patent law applied to applications made by this description includes such limitations. Therefore, practicing the method for relieving ARA deficient conditions and maintaining a good fatty acid balance in vivo, including the process of administering the above-mentioned compositions may be limited to non-human mammals.
(Utilization of DPA-containing Material to Prevent Decrease of ARA Levels)
DPA containing material maybe utilized, especially to prevent decrease of ARA levels caused by the intake of xcfx893 unsaturated fatty acids. Effective compositions contain DPA-containing material in an amount effective for preventing the decrease of ARA levels caused by the intake of xcfx893 unsaturated fatty acids, per unit dose. Here xe2x80x9ceffective for preventing decrease of ARA levelsxe2x80x9d means sufficient to significantly diminish the magnitude of decrease of ARA levels, or preferably, sufficient to bring ARA to a level that is the same as when xcfx893 unsaturated fatty acids are not consumed.
The method to produce compositions that prevent the decrease of ARA levels due to xcfx893 unsaturated fatty acid intake comprises two forms. One is when the source of xcfx893 unsaturated fatty acid exists separately from this composition, and the other is when the source of xcfx893 unsaturated fatty acid intake is combined within this composition.
In the former case, first, the average intake of xcfx893 unsaturated fatty acids during a set period by a subject consuming xcfx893 unsaturated fatty acids is identified. Based on the identified average intake, the decrease of ARA levels due to the intake of xcfx893 unsaturated fatty acids by the subject is estimated. In the latter case, first the xcfx893 unsaturated fatty acid content per unit dose to be included within the composition is identified. This may be determined depending on the primarily intended use of xcfx893 unsaturated fatty acids (for example DHA and/or EPA). Next, the decrease of ARA levels in a subject caused by intake of a pre-determined amount of xcfx893 unsaturated fatty acid is estimated. In either case, according to the estimated level of decrease, the amount of DPA effective for preventing decrease of ARA levels is determined. The specific procedures necessary for the process mentioned above may be understood easily by those skilled in the art, and may be carried out appropriately according to the individual subject and the DPA-containing material. Thus, a unit dose of composition comprising an effective amount of DPA-containing material and optionally, xcfx893 unsaturated fatty acid-containing material can be prepared.
In the above composition, DPA-containing material and xcfx893 unsaturated fatty acid-containing material are preferably lipids containing DPA and xcfx893 unsaturated fatty acids. Examples of lipids containing DPA and xcfx893 unsaturated fatty acids are a mixture of lower alkyl esters of DPA, lower alkyl esters of xcfx893 unsaturated fatty acids, and glycerol esters containing DPA and/or xcfx893 unsaturated fatty acids as components. Lipids that contain xcfx893 unsaturated fatty acids are preferably DHA and/or EPA. In one example, the composition may be characterized by DPA content of not less than 0.1%, preferably not less than 1.0%, or more preferably not less than 3.5% with respect to the total amount of fatty acid within the composition. In another example, the composition may be characterized by a DPA content of not less than 0.1%, preferably not less than 1.0%, and more preferably not less than 3.5% and a DHA content of not less than 0.1%, preferably not less than 1.0%, and more preferably not less than 5.0% with respect to the total amount of fatty acids within the composition. Yet in another example, the composition may be characterized by a DPA content of not less than 0.1%, preferably not less than 1.0%, and more preferably not less than 3.5% and a DHA content of not less than 0.1%, preferably not less than 1.0%, and more preferably not less than 5.0% and an EPA content of not more than 20%, preferably not more than 5.0%, and more preferably not more than 1.0% with respect to the total amount of fatty acids within the composition.
Direct administration of ARA is a simple method to prevent decrease of ARA levels in vivo however, even if the administration takes into account the biologically required amount, that amount varies among individuals and may therefore, in certain cases, cause excessive intake. ARA is the direct precursor of eicosanoids, in contrast, in this invention, the body supplies ARA as necessary, that is, by responding to the decrease of ARA levels, through retroconversion of the administered DPA, and when the ARA level returns to a normal value, retroconversion stops. Normal levels of ARA varies among the tissues however, retroconversion of DPA is regulated to match the normal value in each of the tissues. When the retroconversion of DPA to ARA stops, a surplus of DPA will remain. However, since DPA is not the direct precursor of eicosanoids, and since DPA does not have the effect of increasing ARA to a level that is more than necessary, this will be stocked in vivo as an effective source of ARA, therefore, the effect on the body is indirect and milder than direct administration of ARA.
(Food/medicaments Comprising DPA-containing Material)
Any one of the above-mentioned compositions of this invention is not limited in particular with regard to its mode of use. Representative modes of use include foods, food additives, medicaments, additives for medicaments, feedstuffs, and baits.
Examples of food compositions, besides general foods, are functional foods, nutrient-supplementing foods, formula suitable for feeding infants or premature infants, baby foods, foods for expectant or nursing mothers, and geriatric foods. Examples of foods containing oils and fat include natural foods, which by nature contain oils and fat such as meat, fish, and nut, food to which oils and fat are added upon cooking such as soup, food for which oils and fat are used as heating medium such as doughnuts, oils and fat food such as butter, processed food to which oils and fat are added during processing such as cookies, or food to which oils and fat are sprayed or applied upon completion of processing such as hard biscuits. Furthermore, the lipids of this invention may also be added to agricultural food, fermented food, livestock food, seafood, or drink, which normally do not contain oils and fat. Food additive is a general term for an intermediate product that may be utilized to prepare any of these foods. The definition of food includes functional foods. Functional foods and medicaments may be provided in processed forms such as, enternal agent for promoting nutrition, powder, granule, troche, internal solution, suspension, emulsion, syrup, capsule, and such. Additives for medicaments include intermediate products that may be used to prepare the medicaments of choice. The composition of this invention may also be utilized as feedstuffs for raising animals such as domestic animals, and feed for breeding fish, shellfish, crustacean, and fry.
(Preparation and Purification of DPA-containing Material)
The DPA-containing material of this invention may be obtained from any of the synthetic and natural resources, for example, material that is chemically synthesized and material obtained from plant or animal sources. Examples of plant or animal sources are fish oil, fish powder, fish lees, fish oil extract and so on. Examples of fish oil are oils of sardine, herring, tuna, bonito, saury, menhaden, and such.
Preferably, DPA-containing material may be a DPA-containing lipid derived from microbial cells obtained by cultivating microorganisms that have the ability to produce DPA. DPA-containing lipids derived from microorganisms may be utilized in a variety of forms including the microbial cells themselves, lipid extract extracted from bacterial cells, purified lipids obtained by further purification of the lipid extract, and altered lipids in which the lipid extract or lipid extract are further modified by chemical reactions (for example, esterification).
Microorganisms belonging to any one of the categories shown below are examples of microorganisms that have the ability to produce DPA:
genus Thraustochytrium
genus Schizochytrium
genus Japonochytrium
genus Ulkenia
genus Vibrio
genus Cyclotella
genus Emiliania
genus Isochrysis
genus Nanochloropsis
genus Chaetoceros
genus Phaeodactylum
genus Amphidinium
genus Gonyaulax
genus Peridirmium
genus Chroomonas
genus Cryptomonas
genus Hemiselmis
genus Chiloomonas
genus Chlorella
genus Histiobranchus
genus Coryphenoides
genus Conidiobolus
genus Entomrorhpthora
A microorganism belonging to any one of genus Thraustochytrium, genus Schizochytrium, genus Japonochytrium, genus Ulkenia, genus Vibrio, genus Cyclotella, or genus Emiliania is a microorganism that may produce DPA in high proportion with respect to the total amount of fatty acids.
Specific examples of microorganisms mentioned above are the following: bacteria isolated from the deep sea, Vibrio marinus ATCC 15381; genus Vibrio bacteria isolated from the intestine of deep sea fish; phlagellate bacteria (such as, Thraustochytrium aureum ATCC 34303; Thraustochytrium sp. ATCC 28211, ATCC 20890 and ATCC 20891: Schizochytrium sp. ATCC 20888 and ATCC 20889 (U.S. Pat. No. 5,340,742); genus Thraustochytrium SR21 (Nippon Nogei KagakuKaishi,vol. 69, extra edition, July 5, 1995; National Institute of Bioscience and Human-Technology Agency of Industrial Science Technology accession No. FER MBP-5034); Japonochytriwn sp. ATCC 28207 (Japanese Laid-open(kokai) Patent Publication No. (JP-A) Hei 1-199588 (1989)); microalgae (for example Cyclotella cryptica; and Emiliania sp. (JP-A) Hei 5-308976 (1993)). These strains can be obtained, for example, without any restriction from American Type Culture Collection.
SAM2180 strain and SAM2179 strain belonging to the genus Ulkenia, which were isolated from seawater by the present inventors, can also be used favorably as microorganisms that have the ability to produce DPA. The SAM 2179 strain was deposited with the National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology (address; 1-3, Higashi 1 chome, Tsukuba-shi, Ibaraki-ken, JAPAN), on Jul. 23, 1996 and assigned an accession No. FERM BP-5601.
Microorganisms capable of producing DPA can be cultivated following standard methods. For example, cultivation can be carried out by inoculating a liquid or solid medium with the microbial strain on a loop, in spores, in mycelium, or as a pre-culture. By cultivation, lipids containing DPA become stored within the microbial cells.
After cultivation, the cultured microbial cells are collected from the culture by conventional solid-liquid separation techniques such as centrifugation and filtration. The cultivated cells are extensively washed with water and the wet cells are collected. By drying these cells, dry bacterial cells are obtained. Drying of the cells may be carried out by freeze-drying, air-drying and such. Such wet or dry cells comprise DPA-containing lipids, and these cells may be used directly for the purpose of this invention. Preferably, DPA-containing lipids are extracted by further extraction of the dried cells under a stream of nitrogen using organic solvents. Ether, hexane, methanol, ethanol, chloroform, dichloromethane, petroleum ether and such may be used as organic solvents. Alternative extraction with methanol and petroleum ether, and extraction using a monophasic solvent consisting of chloroform-methanol-water can also yield good results. Removal of organic solvent from the extract under reduced pressure yields DPA-containing lipid extract, which may be used for the purpose of this invention.
Various highly unsaturated fatty acids are included as components of lipid within the lipid extract obtained as described above. It is possible to separate the lipids according to different types by directly subjecting the lipid extract to the appropriate purification steps (for example, chromatography). More preferably, purification is carried out after conversion of the highly unsaturated fatty acids in the lipid extract to the esters of lower alcohols (for example, DPA ethyl ester, DHA ethyl ester, EPA ethyl ester, and so on). Such esterification will facilitate the separation of DPA ester as a DPA-containing lipid from lipid components that do not contain DPA. This will also facilitate the separation of other fatty acids such as palmitic acid, oleic acid, and such (these are also esterified during the esterification of highly unsaturated fatty acids) that may be produced during cultivation of the microorganisms.
Esterification of highly unsaturated fatty acids can be carried out using known conditions. For example, to obtain the ethyl ester, the extracted lipids mentioned above is preferably treated by reagents such as 5xcx9c10% HCl-anhydrous ethanol solution, 10xcx9c50% BF3-ethanol solution, and such for 1xcx9c24 hours at room temperature.
To collect the highly unsaturated fatty acid ethyl ester from the above-mentioned solution, extraction by organic solvents such as hexane, ether, and ethyl acetate is preferred. Upon drying this extract over drying agents such as sodium sulfate, the organic solvent is removed, preferably under reduced pressure, to yield a mixture containing fatty acid esters as its major component. This mixture also contains a variety of fatty acid ethyl esters besides DPA ethyl ester. This mixture may be used for the purpose of this invention. If necessary, column chromatography, low temperature crystallization, urea addition, liquid-liquid counter current distribution chromatography, and such may be used alone or in combination to isolate the DPA ethyl ester from the mixture. The obtained purified DPA ethyl ester may be used especially favorably for the purpose of this invention.
In order to obtain free DPA from the purified DPA ethyl ester, which is isolated as described above, the ester should be hydrolyzed by alkali then extracted with organic solvents such as ether, ethyl acetate and such. The obtained free DPA and its salt may be used for the purpose of this invention. To prepare free DPA not via its esterified derivative, the lipid extract mentioned above is subjected to alkaline hydrolysis under appropriate conditions (for example, under 5% sodium hydroxide at room temperature for 2xcx9c3 hours). From the hydrolysis reaction solution, free DPA can be obtained by extraction of fatty acids following standard purification methods.
(Novel Lipids Containing DPA)
This invention introduces novel lipids that may be utilized favorably as DPA-containing lipids. These lipids contain ARA, DPA, and DHA (and optionally EPA), and are characterized by the combination of three ratios, ARA/DHA, DPA/DHA, and EPA/DHA (each expressed by their weight ratio). Typically the ARA/DHA ratio is 0.03xcx9c0.4, preferably 0.05xcx9c0.4, and more preferably 0.1xcx9c0.4. Typically the DPA/DHA ratio is not less than 0.07, preferably 0.07xcx9c5.0, more preferably 0.07xcx9c3.0, and evenmore preferably 0.07xcx9c0.5. The EPA/DHA ratio is typically not more than 0. 05, preferably not more than 0.04%, and more preferably not more than 0.03%. In general, when the three ratios are within this range, the amount of DPA may be effective for preventing decrease of ARA levels caused by the intake of xcfx893 unsaturated fatty acids (that is, DHA, and when present, EPA).
The lipids mentioned above are preferably lipids that are obtained by cultivating one type of microorganism (that is, lipids derived from microbial cells obtained by cultivating one or more batches of a certain microorganism), or a mixture of lipids obtained by separately cultivating many different microorganisms (that is, lipid derived from microbial cells obtained by separately cultivating one or multiple batches of two or more different microorganisms). The lipids of this invention may be obtained by combining lipids that are obtainable by cultivating microorganisms that can produce DPA and DHA while hardly producing any EPA such as the genus Thraustochytrium, genus Schizochytrium, genus Japonochytrium, and genus Ulkenia, with lipids obtainable by cultivating microorganisms that can produce ARA but hardly produces any EPA, such as the species alpina, banieri, elongate, exigua, minutissima, verticilata, hygrophila, polycephla, and schmuckeri belonging to the sub genus Mortierella of the genus Mortierella. In this lipid, each of ARA, DPA, and DHA (and optionally EPA) may exist within the glycerol ester and may exist especially in triglycerides.
The novel lipids mentioned above relieve ARA deficient conditions and maintain a good fatty acid balance in vivo, or show the effect of preventing decrease of ARA levels. At the same time, they are useful because they contain a relatively small amount of ARA themselves, the naturally strong physiological effect of ARA towards the body is hardly seen, and their effect on the body is mild. Accordingly, this lipid may be utilized favorably as a component of nutrient-supplementing foods including formula for feeding infants, formula for premature infants, baby foods, foods for expectant and nursing mothers, geriatric foods, and foods for sick patients where enrichment of ARA and DHA is desired, and as feeds for animals.

Utilization of material containing docosapentaenoic acid


In one embodiment, a (hard-drive) read channel has a phase detector used in a timing recovery loop. The phase detector utilizes the sign bit and confidence value from a received log-likelihood ratio (LLR) signal to generate a mean value. The mean value is convolved with a partial response target to generate an estimated timing error signal. When implemented in a hard-drive read channel, the phase detector allows for timing recovery with lower loss-of-lock rates.

FIG. 1 is a block diagram of a prior-art read channel 100 for a hard drive. Read channel 100 receives an analog input signal 121 corresponding to data stored on the hard drive and generates a digital decoded output signal 129 representing the data stored on the hard drive.
In particular, analog-to-digital converter (ADC) 122 digitizes analog input signal 121 to generate digital input signal 123. Digital finite impulse response (DFIR) filter equalizer 124 equalizes digital input signal 123 to generate equalized digital signal 125. Soft detector 126 converts equalized digital signal 125 into soft values, such as multi-bit log likelihood ratio (LLR) values 127, where each LLR value has a hard-decision sign bit and a multi-bit (e.g., 4-bit) confidence value. Soft detector 126 implements a suitable detection technique, such as Viterbi soft-output detection or maximum a posteriori (MAP) detection, to generate LLR values 127. Decoder 128 decodes the LLR values to generate decoded output signal 129. For example, if the data stored on the hard drive is encoded using a low-density parity check (LDPC) code, then decoder 128 performs LDPC decoding to generate decoded output signal 129 from LLR values 127.
Phase detector 130 processes equalized digital signal 125 from equalizer 124 and the sign bits of LLR values 127 from soft detector 126 to generate an estimated timing error signal 131. In one conventional implementation, phase detector 130 generates estimated timing error signal 131 by (i) convolving the sign bits with a finite impulse response (FIR) filter, (ii) generating the difference between the FIR filter output and a one-cycle-delayed version of equalized digital signal 125, and (iii) multiplying that difference by an estimate of the slope of equalized digital signal 125. Loop filter 132 integrates estimated timing error signal 131 to output an averaged error signal 133. Time-base generator (e.g., local oscillator (LO)) 134 generates LO clock signal 135. Interpolator 136 shifts the phase of LO clock signal 135 based on averaged error signal 133 to generate sampling clock signal 137, which determines the timing of the sampling of analog input signal 121 by ADC 122.
In hard-drive read-channel technology, the signal-to-noise ratio (SNR) continues to decrease due to increasing storage density of the disks. Conventional timing-recovery phase detectors that estimate timing information from equalized samples (such as equalized digital signal 125) and hard decisions (such as the sign bits of LLR values 127) might not operate properly in low-SNR environments, resulting in an unacceptably high loss-of-lock rate (LOLR), which reduces system throughput.


An apparatus for testing the tear strength of a tear strip in a paperboard blank. The blank is placed on and clamped to the apparatus, the latter having a force gauge mounted on it. One end of a flexible wire has a clip fastener which is attached to the end of the pull tab in the paperboard blank. The other end of the flexible wire is attached to the force gauge, the gauge measuring the amount of force required to rip the tear strip from the surrounding paperboard blank. In one embodiment of the invention, a motor is mounted on the apparatus and pulls the force gauge, the flexible wire passing around a pulley mounted on the apparatus and leading to the clip fastener. In another embodiment, the flexible wire passes over several pulleys, one of which is secured to a travelling, non-rotating nut. The nut is carried by a threaded rod rotatably journaled in the frame. A motor is coupled to the rod to rotate it, thereby pulling on the clip fastener upon movement of the nut.

This invention relates to an apparatus for testing tear strips in paperboard cartons. Paperboard cartons are often provided with tear strips to facilitate carton opening for dispensing of the contents. During manufacture of the blanks for such cartons, the blanks are scored or otherwise weakened along predetermined parallel lines to form a tear strip or along lines at an angle to each other if only a limited tearing of the carton is desired.
During manufacture of blanks having tear strips, it is at times desired to check the integrity and uniformity of the scoring or weakening, so as to maintain constant depth and width of the scores or other weakening to ensure uniformity of the pull required to initiate and to sustain ripping of the tear strip away from the surrounding portion of the carton blank. During the scoring process, for example, scoring dies or other conventional scoring apparatus can become dulled, or the desired force between scoring dies and an anvil can vary, visually unnoticeable by personnel operating the scoring apparatus.
The prior art is aware of tear strip testing devices, as may be seen by reference to U.S. Pat. Nos. 2,983,139 issued to Galbraith et al., 3,037,379 issued to Wagner et al., and 3,318,143 issued to Helms.


The invention relates to low-temperature-stabilized fatty acid mixtures comprising

The present invention relates to mixtures of fatty acids and comb polymers of improved low-temperature stability, and to their use for improving the lubricity of middle-distillate fuel oils.
1. Field of the Invention
Mineral oils and mineral-oil distillates which are used as fuel oils generally comprise 0.5% by weight or more of sulfur, which causes the formation of sulfur dioxide on combustion. In order to reduce the resultant environmental pollution, the sulfur content of fuel oils is constantly being reduced further. The EN 590 standard, which relates to diesel fuels, currently prescribes a maximum sulfur content of 350 ppm in Germany. In Scandinavia, fuel oils containing less than 50 ppm and in exception cases less than 10 ppm of sulfur are already in use. These fuel oils are generally produced by subjecting the fractions obtained from crude oil by distillation to reductive refining. During desulfurization, however, other substances are also removed which give the fuel oils a natural lubricity. These substances include, inter alia, polyaromatic and polar compounds.
However, it has now been found that the friction-and wear-reducing properties of fuel oils become worse with increasing degree of desulfurization. These properties are frequently so unsatisfactory that corrosion phenomena must be expected after only a short time on the materials lubricated by the fuel, such as, for example, distributor injection pumps of diesel engines. The maximum value for a 95% distillation point of a maximum of 360xc2x0 C. which has been prescribed in EN 590 since the year 2000 and the further reduction in the 95% distillation point to below 350xc2x0 C. and in some cases below 330xc2x0 C. which has in the meantime been effected in Scandinavia intensify these problems further.
2. Description of the Related Art
The prior art has therefore described approaches which are intended to represent a solution to this problem (so-called lubricity additives).
JP-A-Hei-11-1692 discloses fuel-oil compositions comprising from 0.001 to 0.5% by weight of a C8-C30-fatty acid mixture which comprises at least 75% by weight of unsaturated fatty acids having one and two double bonds, where the ratio between monounsaturated and diunsaturated fatty acids is from 1:3 to 15:1 by weight, and the fuel-oil composition comprises at most 0.2% by weight of sulfur and at most 40% by weight of aromatic compounds. The oils may comprise further additives, such as antioxidants and flow improvers.
JP-A-Hei-10-110 175 discloses additives for improving the lubricity of fuel oils. The additives comprise a fatty acid selected from straight-chain saturated or unsaturated C8-C28-fatty acids, and a pour point depressant or a cold-flow improver. The fuel oils have a maximum sulfur content of 0.05% by weight.
The fatty acids used in accordance with the prior art have the disadvantage that they solidify on storage at low temperatures, i.e. often at room temperature, usually at temperatures of from 0xc2x0 C. to at the latest xe2x88x925xc2x0 C., or deposit crystalline fractions and cause problems in handling. This problem can only be partially solved even by dilution with organic solvents, since fractions also crystallize from these solutions or the solution gels and solidifies. For use as lubricity additives, they therefore have to be diluted to a great extent or stored in heated storage containers and dispensed via heated lines. The additive mixtures proposed in JP-A-Hei-10-110 175 have the problem of the high proportions of pour point depressants or cold-flow improvers which are necessary for the preferred fatty acids, and the resultant high viscosity or poor solubility of these additives, which result in clouding or gelling of the concentrates at low storage temperatures.
The object on which the present invention is based was to find lubricity additives which improve the lubricity of middle distillates at reduced dispensing rates, but remain homogeneous, clear and in particular flowable even at low temperatures.
Surprisingly, it has been found that mixtures of fatty acids with comb polymers remain flowable and clear for an extended time even at significantly reduced temperatures, in some cases down to below xe2x88x9220xc2x0 C., in particular cases down to below xe2x88x9230xc2x0 C. and in special cases down to below xe2x88x9240xc2x0 C., and in addition improve the lubricity of middle distillates more efficiently than pure fatty acids of the prior art.
The invention thus relates to low-temperature-stabilized fatty acid mixtures comprising from 10 to 99.99% by weight of fatty acid mixtures comprising
A1) from 1 to 99% by weight of at least one saturated mono- or dicarboxylic acid having 6 to 50 carbon atoms,
A2) from 1 to 99% by weight of at least one unsaturated mono- or dicarboxylic acid having 6 to 50 carbon atoms, and from 0.01 to 90% by weight of copolymers comprising
B1) from 40 to 60 mol % of bivalent structural units of the formula
where Xxe2x95x90O or Nxe2x80x94R1,
in which a and b=0 or 1 and a+b=1, and
B2) from 60 to 40 mol % of bivalent structural units of the formula
xe2x80x94H2Cxe2x88x92CR2R3xe2x80x94B2
and, if desired,
B3) from 0 to 20 mol % of bivalent structural units derived from polyolefins, where the polyolefins can be derived from monoolefins having 3 to 5 carbon atoms, and in which
R1 is an alkyl or alkenyl radical having from 10 to 40 carbon atoms or an alkoxyalkyl radical having from 1 to 100 alkoxy units and from 1 to 30 carbon atoms in the alkyl radical, and
R3 is a radical of the formula OCOR4 or COOR4, in which R4 is C1-C24-alkyl, and the number of carbon atoms in the polyolefin molecules on which the structural units B3) are based is from 35 to 350, and
R2 is hydrogen or methyl.
The invention also relates to low-temperature-stabilized solutions of the fatty acid mixtures according to the invention in solvents, such as, for example, aliphatic and/or aromatic hydrocarbons or hydrocarbon mixtures, and oxygen-containing hydrocarbons, or mixtures thereof. The fatty acid mixtures according to the invention preferably comprise 1-80%, especially 10-70%, in particular 25-60%, of solvent.
The invention furthermore relates to fuel oils comprising, in addition to a relatively large proportion of middle distillate having a sulfur content of up to 0.05% by weight, a relatively small proportion of a low-temperature-stabilized fatty acid mixture as defined above.
The invention furthermore relates to the use of said fatty acid mixtures comprising constituents A and B for improving the lubrication properties of low-sulfur middle distillates having a sulfur content of up to 0.05% by weight.
Preferred fatty acids (constituent A) are those having 8-40 carbon atoms, in particular 12-22 carbon atoms. The alkyl radicals in the fatty acids essentially consist of carbon and hydrogen. However, they may carry further substituents, such as, for example, hydroxyl, halogen, amino or nitro groups, so long as these do not impair the predominant hydrocarbon character.
Constituent A2) may contain one or more double bonds and be of natural or synthetic origin. In the case of polyunsaturated carboxylic acids, their double bonds may be isolated or conjugated. The proportion of saturated fatty acids A1) in the mixture of A1) and A2) is preferably less than 20% by weight, in particular less than 10% by weight, especially less than 5% by weight. In preferred fatty acid mixtures, which is taken to mean the combination of A1) and A2) here, at least 50% by weight, in particular at least 75% by weight, especially at least 90% by weight, of the constituents contain one or more double bonds. These preferred fatty acid (mixtures) have iodine numbers of at least 40 g of l/100 g, preferably at least 80 g of l/100 g, in particular at least 125 g of l/100 g.
Examples of suitable fatty acids are lauric, tridecanoic, myristic, pentadecanoic, palmitic, margaric, stearic, isostearic, arachic and behenic acid, oleic and erucic acid, palmitoleic, myristoleic, linoleic, linolenic, elaeosteric and arachidonic acid, ricinoleic acid and fatty acid mixtures obtained from natural fats and oils, such as, for example, coconut oil, groundnut oil, fish, linseed oil, palm oil, rape oil, ricinene oil, castor oil, colza oil, soya oil, sunflower oil and tall oil fatty acid.
Likewise suitable are dicarboxylic acids, such as dimeric fatty acids and alkyl- and alkenylsuccinic acids containing C8-C50-alk(en)yl radicals, preferably containing C8-C40-, in particular containing C12-C22-alkyl radicals. The alkyl radicals may be linear or branched (oligomerized alkene, PIB).
The fatty acids may furthermore comprise 1-40% by weight, especially 1-25% by weight, of resin acids, based on the weight of A1) and A2) together.
The structural units in the compounds based on the formula B1) are derivatives of maleic, fumaric or itaconic acid. R1 is preferably an alkyl radical having preferably from 10 to 24, in particular from 12 to 20, carbon atoms.
Preferred alcohols R1xe2x80x94OH are, for example, 1-decanol, 1-dodecanol, 1-tridecanol, isotridecanol, 1-tetradecanol, 1-hexadecanol, 1-octadecanol, eicosanol, docosanol, tetracosanol, mixtures thereof, and naturally occurring mixtures, such as, for example, coconut fatty alcohol, tallow fatty alcohol and behenyl alcohol. The alcohols may be of natural or synthetic origin.
Besides the use of individual alcohols R1xe2x80x94OH for the esterification, the use of alcohol mixtures, for example of dodecanol and tetradecanol or tetradecanol and hexadecanol in a ratio of from 1:10 to 10:1, in particular from 3:1 to 1:3, has proven particularly successful here. Through variation of the alcohol components, the additive can be matched to the fatty acid to be treated. Thus, for example, addition of, for example, 15% by weight of behenyl alcohol to above-mentioned mixtures enables the effectiveness in fatty acids having a relatively high proportion of saturated, in particular saturated C18- and C20-fatty acids to be optimized. The radicals R1 may be linear or branched, where the branch may include a secondary or tertiary carbon atom. Linear radicals R1 are preferred. If R1 is branched, it preferably carries this branch in the 2-position. It is possible to use different radicals R1, i.e. to employ different alcohols in the preparation of the maleic acid, itaconic acid and/or fumaric acid ester mixtures.
In a further preferred embodiment, the radicals R1 in the formula B1) are alkoxyalkyl radicals of the formula
(Oxe2x80x94A)Xxe2x80x94R5
in which A is a C2-C4-alkylene radical, x is an integer from 1 to 100, and R5 is a C1-C30-alkyl radical. The (Oxe2x80x94A) unit is preferably an ethoxy or propoxy unit. If alkoxylated units are used for R1, this preferably takes place in a mixture with radicals R1 which are not alkoxylated. The proportion of alkoxylated radicals R1 preferably does not exceed 20 mol % (based on all radicals R1). R5 may be linear or branched. If R5 is branched, the branch is preferably in the 2-position. R5 is preferably linear.
Primary amines having from 12 to 30 carbon atoms, in particular from 12 to 22 carbon atoms, such as dodecylamine, tetradecylamine, hexadecylamine, octadecylamine and eicosylamine, and mixtures thereof, such as coconut fatty amine and tallow fatty amine, have proven particularly suitable for the imidation (structural units B1b).
The structural units of the formula B2) are derived firstly from xcex1-olefins. These xcex1-olefins preferably have from 10 to 40 carbon atoms, in particular from 12 to 26 carbon atoms. C14-C24-xcex1-olefins are particularly preferred. The carbon chain of the xcex1-olefins may be straight-chain or branched, preferably straight-chain. Examples of suitable olefins are 1-dodecene, 1-tetradecene, 1-tridecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 1-hemicosene, 1-docosene, 1-tetracosene, 1-hexacosene, 1-octacosene, etc., and mixtures thereof. Commercially available olefin fractions, such as, for example, C20-C24- or C30+-olefin, are likewise suitable.
The structural units of the formula B2) are furthermore derived from vinyl, acrylic or methacrylic acid esters containing alkyl radicals carrying from 1 to 3 carbon atoms. Particular preference is given to structural units B2) which are derived from vinyl acetate or vinyl propionate.
The bivalent structural units mentioned under B3) are derived from polyolefins which are derived from monoolefins having 3, 4 or 5 carbon atoms. Particularly preferred monoolefins as parent structures of the polyolefins are propylene and isobutylene, from which polypropylene and polyisobutylene are formed as polyolefins. The polyolefins preferably have an alkylvinylidene content of at least 50 mol %, in particular of at least 70 mol %, especially at least 75%. The polyolefins which are not susceptible to free-radical polymerization generally remain in the product as non-copolymerized constituents, which also has a positive effect on the solubility and effectiveness of the polymers. The term alkylvinylidene content is taken to mean the content in the polyolefins of structural units based on compounds of the formula
in which R6 or R7 is methyl or ethyl, and the other group is an oligomer of the C3-C5-olefin. The number of carbon atoms in the polyolefin is from 35 to 350. In the preferred embodiment of the invention, the number of carbon atoms is from 45 to 250. In a further preferred embodiment of the invention, the proportion of structural units B3) is from 1 to 20 mol %, in particular from 2 to 15 mol %.
The polyolefins on which the structural units B3) are based can be obtained by ionic polymerization and are available as commercial products (for example (copyright)Ultravis, (copyright)Napvis, (copyright)Hyvis, (copyright)Glissopal) (polyisobutenes from BP and BASF having various alkylvinylidene contents and molecular weights.
The mean molecular weight of the copolymers B) according to the invention is generally from 1500 to 200,000 g/mol, in particular from 2000 to 100,000 g/mol (GPC against polystyrene standard in THF).
The copolymers B) according to the invention are preferably prepared at temperatures of from 50 to 220xc2x0 C., in particular from 100 to 190xc2x0 C., especially from 130 to 170xc2x0 C. The preferred preparation process is solvent-free bulk polymerization, but it is also possible to carry out the polymerization in the presence of aromatic, aliphatic or isoaliphatic aprotic solvents, such as hexane, cyclohexane, toluene, xylene or of solvent mixtures, such as kerosine or solvent naphtha. In the case of solution polymerization, the temperature can be set particularly simply through the boiling point of the solvent or by working under subatmospheric or superatmospheric pressure.
The reaction of the monomers is initiated by free-radical-forming initiators (free-radical chain starters). This class of substances includes, for example, oxygen, hydroperoxides, peroxides and azo compounds, such as cumene hydroperoxide, t-butyl hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide, bis(2-ethylhexyl) peroxide carbonate, t-butyl perpivalate, t-butyl permaleate, t-butyl perbenzoate, dicumyl peroxide, t-butyl cumyl peroxide, di(t-butyl) peroxide, 2,2xe2x80x2-azobis(2-methyl-propanonitrile) or 2,2xe2x80x2-azobis(2-methylbutyronitrile). The initiators are employed individually or as a mixture of two or more substances in amounts of from 0.01 to 20% by weight, preferably from 0.05 to 10% by weight, based on the monomer mixture.
The copolymers can be prepared by copolymerization of olefin and/or unsaturated ester (component B2) and, if desired, polyolefin (component B3) with either maleic acid, fumaric acid, itaconic acid, itaconic anhydride or maleic anhydride or maleic ester, fumaric ester or itaconic ester or maleimide or itaconimide (component B1). If a copolymerization is carried out with acids or anhydrides, the resultant copolymer is esterified or imidated after the preparation. This esterification or imidation is carried out, for example, by reaction with from 1.5 to 2.5 mol of alcohol or from 0.8 to 1.2 mol of amine per mol of annydride at from 50 to 300xc2x0 C., in particular 120-250xc2x0 C. The reaction water can be distilled off by means of a stream of inert gas or removed by azeotropic distillation. Copolymers B) having acid numbers of less than 50 mg of KOH/g, in particular less than 30 mg of KOH/g, especially less than 20 mg of KOH/g, are preferred.
The comonomers B1 and B2 are preferably employed in equimolar amounts. The proportion of comonomers B3 is preferably from 0.5 to 10 mol %, in particular from 1 to 5 mol %.
The mixing ratio between A and B can vary within broad limits. Thus, even small amounts of B of from 100 ppm to 50,000 ppm, preferably from 1000 ppm to 10,000 ppm, in fatty acid solutions act as low-temperature additive for A. They are capable of suppressing the inherent crystallization of the fatty acid, which results in a reduction in the cloud point, and, where appropriate, prevents the sedimentation of crystals formed and thus facilitates easy handling at reduced temperatures. For specific problem solutions, however, from 5% to 50%, in particular cases up to 90%, of constituent B, based on the amount of constituent A, may also be present. In particular, the inherent pour point of the additive is lowered and the lubricity of the additive-containing oil is improved. Accordingly, the preferred mixing ratio of A:B is form 1:10 to 1:0.0001, in particular from 1:4 to 1:0.0005, especially from 1:1 to 1:0.001.
The fatty acid mixtures according to the invention are added to oils in amounts of from 0.001 to 0.5% by weight, preferably from 0.001 to 0.1% by weight. They can be employed as such or also dissolved in solvents, such as, for example, aliphatic and/or aromatic hydrocarbons or hydrocarbon mixtures, such as, for example, toluene, xylene, ethylbenzene, decane, pentadecane, gasoline fractions, kerosine or commercial solvent mixtures, such as solvent naphtha, (copyright)Shellsol AB, (copyright)Solvesso 150, (copyright)Solvesso 200, (copyright)Exxsol, (copyright)Isopar and (copyright)Shellsol D grades. Suitable solvents are also oxygen-containing hydrocarbons. The fatty acid mixtures according to the invention preferably comprise 1-80%, especially 10-70%, in particular 25-60%, of solvent. The fatty acid mixtures, which can also be employed without problems at low temperatures of, for example, 0xc2x0 C., in some cases also below xe2x88x9220xc2x0 C. and in special cases at xe2x88x9240xc2x0 C. or lower, improve the lubricity of the additive-containing oils and their low-temperature and corrosion-protection properties.
For the preparation of additive packages for special problem solutions, the fatty acid mixtures according to the invention may also be employed together with one or more oil-soluble co-additives which, even on their own, improve the low-temperature flow properties and/or lubricity of crude oils, lubricating oils or fuel oils. Examples of co-additives of this type are vinyl acetate-containing copolymers or terpolymers of ethylene, paraffin dispersants and alkylphenol-aldehyde resins.
Thus, mixtures of the fatty acid mixtures according to the invention with copolymers which comprise from 10 to 40% by weight of vinyl acetate and from 60 to 90% by weight of ethylene have proven highly successful. According to a further embodiment of the invention, the fatty acid mixtures according to the invention are employed as a mixture with ethylene-vinyl acetate-vinyl neononanoate terpolymers or ethylene-vinyl acetate-vinyl neodecanoate terpolymers for improving the flow properties of mineral oils or mineral oil distillates. Besides ethylene, the terpolymers of vinyl neononanoate or of vinyl neodecanoate comprise from 10 to 35% by weight of vinyl acetate and from 1 to 25% by weight of the respective neo compound. Besides ethylene and from 10 to 35% by weight of vinyl esters, further preferred copolymers also comprise from 0.5 to 20% by weight of olefin, such as diisobutylene, 4-methylpentene or norbornene. The mixing ratio of the fatty acid mixtures according to the invention with the ethylene-vinyl acetate copolymers described above or the terpolymers of ethylene, vinyl acetate and the vinyl esters of neononanoic or of neodecanoic acid is (in parts by weight) from 20:1 to 1:20, preferably from 10:1 to 1:10.
Furthermore, the fatty acid mixtures according to the invention can be employed as a mixture with paraffin dispersants. Paraffin dispersants reduce the size of the paraffin crystals and have the effect that the paraffin particles do not settle out, but instead remain dispersed in colloidal form with significantly reduced sedimentation volition. Furthermore, they increase the lubricity of the fatty acid mixtures according to the invention. Paraffin dispersants which have proven successful are oil-soluble polar compounds containing ionic or polar groups, for example amine salts and/or amides, which are obtained by reaction of aliphatic or aromatic amines, preferably long-chain aliphatic amines, with aliphatic or aromatic mono-, di-, tri- or tetracarboxylic acids or anhydrides thereof (cf. U.S. Pat. No. 4, 211,534). Similarly, products of the reaction of nitrogen-containing polycarboxylic acids with long-chain amines are suitable (cf. EP 0597278). Other paraffin dispersants are copolymers of maleic anhydride and xcex1,xcex2-unsaturated compounds, which can likewise be reacted with primary monoalkylamines and/or aliphatic alcohols (cf. EP 0 154 177), the products of the reaction of alkenylspirobislactones with amines (cf. EP 0 413 279 B1) and, in accordance with EP 0 606 055 A2, products of the reaction of terpolymers based on xcex1,xcex2-unsaturated dicarboxylic anhydrides, xcex1,xcex2-unsaturated compounds and polyoxyalkylene ethers of lower unsaturated alcohols. Alkylphenol-aldehyde resins are also suitable as paraffin dispersants.
The fatty acid mixtures according to the invention can thus be employed together with alkylphenol resins. In a preferred embodiment of the invention, these are alkylphenol-formaldehyde resins, for example of the formula
in which R50 is C4-C50-alkyl or -alkenyl, R51 is ethoxy and/or propoxy, n is a number from 5 to 100, and p is a number from 0 to 50.
The mixing ratio of the fatty acid mixtures according to the invention with the above-described paraffin dispersants and alkylphenol resins is (in parts by weight) from 20:1 to 1:20, preferably from 10:1 to 1:10.
The fatty acid mixtures according to the invention are suitable for improving the lubrication properties of animal, vegetable, mineral or synthetic fuel oils with only low dispensing rates. Their improved low-temperature properties make warming and/or dilution during storage and use unnecessary. In addition, they simultaneously improve the low-temperature and corrosion-protection properties of the additive-containing oils. Furthermore, the emulsification properties of the additive-containing oils are impaired less than is the case with the lubrication additives from the prior art. The fatty acid mixtures according to the invention are particularly suitable for use in middle distillates. The term middle distillates is taken to mean, in particular, mineral oils which are obtained by distillation of crude oil and boil in the range from 120 to 450xc2x0 C., for example kerosine, jet fuel, diesel and heating oil. The oils may also comprise or consist of alcohols, such as methanol and/or ethanol. The fatty acid mixtures according to the invention are preferably used in middle distillates which contain 0.05% by weight or less of sulfur, particularly preferably less than 350 ppm of sulfur, in particular less than 200 ppm of sulfur and in special cases less than 50 ppm of sulfur. In general, these are middle distillates which have been subjected to reductive refining and which therefore only contain small proportions of polyaromatic and polar compounds which give them a natural lubricity. The fatty acid mixtures according to the invention are furthermore preferably used in middle distillates which have 95% distillation points below 370xc2x0 C., in particular 350xc2x0 C. and in special cases below 330xc2x0 C. They can also be employed as components in lubricating oils.
The mixtures can be used alone or also together with other fatty acid mixtures, for example with other pour point depressants or dewaxing auxiliaries, with corrosion inhibitors, antioxidants, sludge inhibitors, dehazers, conductivity improvers, lubricity additives and additives for lowering the cloud point. They are furthermore successfully employed together with additive packages which comprise, inter alia, known ash-free dispersion additives, detergents, antifoams and corrosion inhibitors.
The improved low-temperature stability and the effectiveness of the fatty acid mixtures according to the invention as lubricity additives is explained in greater detail by the following examples.

Fatty acid mixtures of improved low-temperature stability which comprise comb polymers, and their use in fuel oils

Abstract: A) from 10 to 99.99% by weight of fatty acid mixtures comprising: A1) from 1 to 99% by weight of at least one saturated mono- or dicarboxylic acid having 6 to 50 carbon atoms, A2) from 1 to 99% by weight of at least one unsaturated mono- or dicarboxylic acid having 6 to 50 carbon atoms, and

Abstract: B) from 0.01 to 90% by weight of copolymers comprising: B1) from 40 to 60 mol % of bivalent structural units of the formula

Abstract: xe2x80x83where Xxe2x95x90O or Nxe2x80x94R1, in which a and b=0 or 1 and a+b=1, and B2) from 60 to 40 mol % of bivalent structural units of the formula

Abstract: and, if desired, B3) from 0 to 20 mol % of bivalent structural units derived from polyolefins, where the polyolefins can be derived from monoolefins having 3 to 5 carbon atoms, and in which a) R1 is an alkyl or alkenyl radical having from 10 to 40 carbon atoms or an alkoxyalkyl radical having from 1 to 100 alkoxy units and from 1 to 30 carbon atoms in the alkyl radical, and b) R3 is a radical of the formula OCOR4 or COOR4, in which R4 is C1-C24-alkyl, and c) the number of carbon atoms in the polyolefin molecules on which the structural units B3) are based is from 35 to 350, and d) R2 is hydrogen or methyl, and to the use of these mixtures for improving the lubrication properties of low-sulfur middle distillates.


A method of operating a telecommunications device wherein the telecommunications device is used to detect an outgoing call from a calling party to a called number. The calling number is used to determine whether or not the calling party is a universal service user. If it is determined that the called number is among a class of numbers exempt from charges, the call is connected. A determination on the sufficiency of funds in a pre-paid account is made. If it is determined that there are insufficient funds in a pre-paid account to cover charges associated with the outgoing call, a message is generated and sent to the calling party or a third party requesting authorization to charge an additional fee for connecting the calling party with the called party. User input is received from the calling party, indicating the calling party""s authorization of such charge. The connection between the calling party and the called party is made. In an alternative embodiment, costs for providing data communications between an initiating party and a universal service user are calculated, in response to a request by the initiating party, in accordance with the network elements required for a requested quality of service.

The present invention relates in general to the field of voice and data communications, and in particular to a novel system for providing sponsored or universal communications services.
Over the years, worldwide consideration has been given to the universal service problemxe2x80x94the desirability of providing telephone service to those who cannot afford to pay and maintain telephone service. Networks are significantly more valuable as more users are able to use the network, and the lack of universal service is a barrier to economic participation by those lacking service. Societal benefits of having even the poorest on the public telecommunications network are so significant that the new U.S. Telecommunications Act of 1996 makes special provisions for universal service as part of the Act, including mechanisms to implement subsidized activities. Many states have life-line services which subsidize telecommunications services for users who meet certain low income tests.
Internationally, there are even larger universal service problems as nations such as the Philippines, China, and the republics of the former Soviet Union try to entice investment in their respective telecommunications infrastructures. In these emerging markets, the number of telecommunications lines per capita is much smaller. Because market-based solutions to the universal service problem in these markets are lacking, capital for network infrastructure is limited.
Therefore, there is a need for an improved apparatus and operating methodology that provides a market-based solution to the universal service problem.
In a preferred embodiment, the invention provides a novel and substantial solution to the problem of providing phone service for those without proven means to pay or enables sponsors wishing to pay on behalf of others, by providing, voice, data, and multi-media services. The invention provides an apparatus and a related method for controlling public network switching activity in a manner which makes it possible to provide universal service, by providing a telephone line to a party without charge, and providing metered billing to persons wishing to contact the party. This method effectively provides universal service for telecommunications voice and/or multimedia applications, without tax or market subsidies.

System and method for providing sponsored of universal telecommunications service and third party payer services


Techniques are described for reducing time to decrypt a next encrypted frame in a content stream by optimizing a license/key acquisition process. When requesting content, a key identifier and/or license identifier may be included within a webpage using a link, script, or similar access point. When a client device sends a request for content, the loading of the webpage within the client device includes the embedded key identifier. Access to the key/license identifier at the client device then may initiate a key/license acquisition process by the client device. The key/license may be obtained from a key management device in parallel with, or prior to, downloading of at least a portion of the content stream.

Movies, music, and other forms of digital content are provided to our computers over the Internet virtually everyday. We receive news, education, and entertainment, as well as many other forms of digital content. However, for a variety of reasons, some of this content is protected. Such protections may take the form of requiring a license that at least identifies various rights to use, play, copy, and/or distribute the associated content. Other protections may include various levels of types of encryption protection that may necessitate a key in order to decrypt the content. However, it may also be the case that the content is either partially protected or not protected at all. Thus, many of today's systems download the content, before they are able to determine whether a key or license is required. Based on this determination, a key and/or license acquisition process may then be performed. These actions, plus downloading the content stream and decompressing the content stream, often means that the consumer waits for some period of time before the requested content may start to play on his or her client device. This delayed time, is sometimes known as a time to first frame for play of the content. This time to first frame may in some instances be such that the consumer becomes frustrated waiting for the content to play. When consumers become frustrated, they may elect not continue to request the content, resulting in possible lose of revenue for content providers, advertisers, or the like. Thus, it is with respect to these considerations and others that the present invention has been made.

Reducing time to first encrypted frame in a content stream


A ceiling fan motor includes a stator assembly and a rotor. The stator assembly includes an iron core. The rotor is rotatably coupled with the stator assembly and includes a housing, a first positioning member and at least one permanent magnet. The housing includes a lateral wall. The lateral wall is enclosed to form an inner space adapted to receive the iron core. The first positioning member is coupled with the lateral wall. The at least one permanent magnet is positioned by the first positioning member. The first positioning member includes a plurality of air-guiding blades.

1. Field of the Invention
The present invention generally relates to a ceiling fan motor and, more particularly, to a ceiling fan motor capable of providing a desired cooling effect for the internal components thereof via the use of an air-guiding blade.
2. Description of the Related Art
FIG. 1 shows a conventional ceiling fan motor 9 including a stator assembly 91 and a rotor 92. The stator assembly 91 includes a shaft 911 and an iron core 912 circumferentially arranged around the shaft 911. The rotor 92 is rotatably coupled with the shaft 911 and includes a housing 921. The housing 921 has a chamber for receiving the iron core 912. A positioning portion 922 is arranged on the inner periphery of the housing 921 for positioning a plurality of permanent magnets 923. Such a ceiling fan motor 9 can be seen in Taiwan Patent Application No. 102148019.
Since the iron core 912 is received in the housing 921, during the operation of the ceiling fan motor 9, it is difficult to effectively dissipate the heat generated due to the hysteresis loss and the eddy loss of the iron core 912 and the windings of the iron core 912. As a result, the stator assembly 91 often remains in a high temperature for a long time. Consequently, the service life of the ceiling fan motor 9 is affected.
Although the housing 921 of the ceiling fan motor 9 may form a plurality of holes or may be spaced from the iron core 912 by a gap in order not to form a closed structure where heat cannot be easily expelled, the heat of the iron core 912 and its windings still remains inside the ceiling fan motor 9 since the ceiling fan motor 9 is usually mounted at a high position (such as the ceiling) where heat often gathers. In addition, the ceiling fan motor 9 often remains in a high temperature due to the long operational time, leading to a higher failure rate of the ceiling fan motor 9.
In light of the disadvantages of the ceiling fan motor 9 such as difficult heat dissipation of the internal components, short service life and higher failure rate, it is necessary to provide a novel ceiling fan motor with an improved heat dissipation efficiency.

Sunonwealth Electric Machine Industry Co., Ltd.


An active vibration control system for reducing vibration of a structure includes a first control loop comprising sensors for sensing forces in a primary vibratory load path and providing signals to a control unit incorporating time domain control logic for providing first actuator demand signals, a second control loop comprising sensors for sensing secondary vibration forces and providing signals to a control unit incorporating frequency domain control logic for providing second actuator demand signals, and a summing device for summing the first and second actuator demand signals and providing resultant signals for operating a plurality of actuators for inputting controlled vibration response forces into the structure to reduce vibration.

1. Field of the Invention
This invention relates to active vibration control systems particularly but not exclusively for use in reducing vibration of a helicopter fuselage.
2. Description of the Prior Art
In active vibration control systems one or more controlled excitations are applied to a vibrating structure to alleviate a vibration response generated by one or more uncontrolled excitation sources. Typically, the sources of the controlled excitations are actuators controlled so as to produce a vibratory force or motion and, in the helicopter case, the source of uncontrolled vibration is a main sustaining rotor. Unlike alternative passive techniques in which a device responds mechanically through feedback of vibration local to the device, active systems are based on the feedback of vibration, usually from sensors dispersed around the structure or airframe, so as to adapt the controlled excitations to account for changes in the uncontrolled vibration forcing which, in the helicopter case, will arise due to changes in operating conditions.
Several techniques based on differing control philosophies have been proposed for implementing active vibration control for alleviating vibration of a helicopter fuselage. One such technique known as Higher Harmonic Control (HHC) is based on the application of vibratory pitch motions to the rotor blades of a main sustaining rotor to reduce the primary vibratory forcing at its source. Another technique has attempted to actively isolate a structure such as a helicopter fuselage from the primary vibration source. Both these techniques suffer performance constraints, the former in terms of power requirements and high speed performance and the latter in terms of a high weight requirement for effective isolation of all the vibratory load paths.
U.S. Pat. No. 4,819,182 describes an active vibration control system which overcomes the problems associated with such prior techniques. Termed "Active Control of Structural Response" (ACSR), the system differs from prior techniques in that it is based on the superposition of the uncontrolled vibration response and the controlled vibration response, which is controlled in such a way that vibration is minimised throughout the structure.
Thus, whilst ACSR uses the basic system components of actuators, controller and sensors of the prior active techniques described above, it operates in a fundamentally different way. ACSR differs from HHC in that the controlled excitations or forces are applied by the actuators at or across points of the structure capable of relative motions in the dominant vibratory modes. The actuators can either be connected between two points of the structure, e.g. between a gearbox and a fuselage, in what is termed a dual point actuation system or alternatively can be connected between the structure at one point and a seismic mass to generate the required forcing. The latter arrangement is termed a single point actuation system. ACSR differs from prior isolation techniques since it makes no attempt to control directly the vibratory load paths across an isolation interface.
ACSR incorporating frequency domain control logic has proved highly successful in helicopters by reducing overall vibration of the fuselage by a value of about 80 percent and localised improvements of over 90 percent. However, transient delays in each control cycle may impose limitations preventing further improvement in such systems. Similarly, ACSR systems incorporating alternative time domain control logic may experience performance limitations due to a lack of adaptability in respect of changing dynamic characteristics.
An objective of this invention therefore is to provide an active vibration control system having the potential for improved performance.


A rubber composition for a hose of the present technology contains: an ethylene-propylene copolymer having an ethylene content of 40 mass % or greater but less than 60 mass %; an ethylene-1-butene copolymer; and carbon black having a nitrogen adsorption specific surface area of 17 to 52 m2/g; a mass ratio of the ethylene-1-butene copolymer to the ethylene-propylene copolymer (ethylene-1-butene copolymer/ethylene-propylene copolymer) being from 10/90 to 90/10.

In recent years, engines have been made smaller to enhance fuel economy of automobiles, and along with this, automobiles having an engine to which a supercharger (turbo) is introduced are becoming more popular. Due to the introduction of the supercharger, the temperature around an engine is increased, and highly heat resistant hoses have been increasingly demanded as radiator hoses, air conditioner hoses, or the like.
Meanwhile, as a rubber composition having heat resistance, for example, Japanese Unexamined Patent Application Publication No. 2016-030761 is proposed.
Japanese Unexamined Patent Application Publication No. 2016-030761 describes
a rubber composition for a heat-resistant conveyor belt including:
an ethylene-1-butene copolymer having a Mooney viscosity at 125° C. of 20 or greater; and
an ethylene-propylene copolymer having a Mooney viscosity at 125° C. of 20 or greater and an ethylene content of 40 to 60 mass %;
a mass ratio of the ethylene-1-butene copolymer to the ethylene-propylene copolymer being from 10/90 to 90/10.
In such circumstances, when the inventors of the present technology prepared a rubber composition using Japanese Unexamined Patent Application Publication No. 2016-030761 as a reference and evaluated this, it was found that such a rubber composition may not satisfy heat resistance that has been required for air conditioner hoses for automobiles, and that the adhesion to reinforcing yarn may be low.


An integrated string consisting of plural mono-filaments, each of which being fused together with adjacent mono-filaments at the contact points and externally having sharp grooves produced by twisting along its length and internally defining confined spiral bores between the component mono-filaments along its length. The external spiral grooves produced by twisting provide frictional resistance against slipping without deteriorating the specific surface tenacity and the tensile strength of the component synthetic mono-filaments. The internal spiral bores between the component mono-filaments improve the flexibility of the string.

The background of the invention will be described on the use of the string for the racket string and the fishing line, which are the principal uses of the string of the present invention.
Sheep gut had been commonly used for the racket string until synthetic materials were developed and twisted strings mainly of nylon filaments replaced the sheep gut racket string. Typical synthetic racket strings consist of a single thick core and two layers of thirty or a single layer of sixteen to eleven thin filaments overlayed around the core filament. The combination of the core filament and the wrapping thin filaments are integrated by twisting, then subjected to resin treatment so that the core filament and the wrapping thin filaments are mutually bonded together.
The specific size of typical racket strings is shown below.
______________________________________ CORRESPON- DIA- DEN- DING STRING USE OF THE STRING METER IER GAUGE ______________________________________ Tennis racket string 1.47mm 17600 No. 80 type A: Tennis racket string 1.28mm 13200 No. 60 type B: Badminton racket string: 0.81mm 5820 No. 24 ______________________________________
The twist number is 2 t.p.i. for the respective strings.
Phenol resin is most commonly used for bonding the component filaments of the string. Phenol resin is applied to the string during the twisting process. The tensile strength of the string bonded by phenol resin is reduced to 70% of the tensile strength of a standard nylon monofilament as the surface of the component filaments of the string is eroded by the erosive action of the phenol resin. The surface of the external component filaments of thus bonded string also is roughened by the erosive action of the phenol resin so that the roughened surface may be damaged and fall off during the stringing of the racket. In order to prevent this damage, it is usual to apply protective coating of nylon resin to the surface of the phenol resin bonded string, however, these treatments reduce the specific strength of the component synthetic material and deteriorate the surface tenacity of the component filaments while reducing the sharpness of the spiral grooves, the frictional resistance of which is essential to the racket string. The intrinsic resistance of sheep gut effectively controls the ball and the resistance of the special grooves of the synthetic string produced by twisting the string corresponds to the intrinsic surface resistance of the sheep gut; therefore, degradation of the sharpness of the special grooves causes the performance of the synthetic string to reduce.
The surface twist grooves, high tensile strength and good flexibility are essential properties for the strings for fishing nets and fishing lines. Therefore, twisted strings are used for these purposes.
The string according to the present invention as hereinbefore described is a multi-filament string integrated by twisting into a substantially single string having a tensile strength exceeding the standard tensile strength of the equivalent nylon mono-filament by 1 to 3 Kgs, the intrinsic surface tenacity of the material, the original sharpness of the spiral twist grooves and high flexibility. These properties of the string of this invention provide a highly strong and durable racket string which effectively controls tennis balls. It will be well understood that the string according to the present invention is sufficiently provided with properties that satisfy the requirments of fishing nets and fishing lines.
Furthermore, although the string according to the present invention is constituted of twisted multi-filaments, the component filaments will not be damaged and broken separately, which is liable to occur in the conventional bonded multi-filament string because the component filaments are integrated in the form of a mono-filament. Thus, the string of the present invention has no possibility that the component filaments are damaged and broken separately.
Still further, when a hollow filament is used instead of a solid filament as the thick core filament, the flexibility of the string is improved still more and if the internal hollow space of the hollow core filament is filled with a dye coloured oil, liquid, fluorescent paint or oil or liquid containing suspended golden or silvery aluminium powder, the string will show beautiful appearance, which is expected to provide a great fish luring effect when the string is used for fishing nets.
Accordingly, an object of the present invention is to provide a twisted synthetic multi-filament string having the intrinsic surface tenacity and tensile strength of the synthetic material, twist grooves which provide frictional resistance against slipping and an improved flexibility provided by defined spiral bores defind between the component filaments. The string of the present invention is widely used for the racket strings, fishing net strings, fishing lines and other purposes.
Another object of the present invention is to provide a method and apparatus for manufacturing the string of the invention.


Heme-containing proteins, such as cytochrome c, are useful in admixture with enzyme-labeled immunoreactants, such as peroxidase-labeled antibodies or fragments thereof. The heme-containing proteins and enzyme-labeled immunoreactants can be supplied in a buffered composition as part of a test kit. The buffered composition comprising the heme-containing protein and peroxidase-labeled immunoreactant excludes 4'-hydroxyacetanilide, which is a phenolic electron transfer agent. The composition can be used in immunoassays for detecting various immunologically reactive species, such as hCG, and chlamydial or gonococcal antigens.

There is a continuous need in medical practice, research and diagnostic procedures for rapid and accurate determinations of biological substances which are believed or known to be present in biological fluids. For example, the presence of drugs, narcotics, hormones, steroids, polypeptides, proteins, polysaccharides, prostaglandins or infectious organisms in blood, saliva, semen, vaginal secretions, urine, tissue cultures and other biological fluids and specimens has to be determined in a rapid and efficient manner for suitable diagnosis and treatment at a cost that is not prohibitive.
To provide such determinations, various methods have been devised for isolating and detecting the presence of a biological or chemical substance which participates in an immunological reaction, such as an antibody or antigenic material, drug or hapten. Such substances are identified herein as "immunoreactants", and biological or chemical substances which specifically bind (or react) with them to form an immunological complex are identified herein as "receptors". Often, one or the other reactants in such a complex, or even a third substance reactive with either of the first two reactants, is labeled with a detectable marker to provide a means for detecting the complex. Radioisotopes, enzymes, chemiluminescent moieties, fluorescent moieties and dyes have been generally used for this purpose.
Immunoassays have been growing in importance in recent years as a means for detecting the presence or amount of infectious agents in animals or humans. Generally, the infectious agent is detected by determining the presence or amount of an immunological complex formed from an antigenic component extracted therefrom, or by determining the presence or amount of antibodies to the infectious agent in a specimen.
In recent years, the use of enzyme labels has received increasing attention because they provide distinct advantages over other labels, particularly radioisotopes and fluorescent markers. Enzyme labels are becoming prominently used in immunoassays for detecting infectious agents in what are known in the art as competitive enzyme immunoassays (EIA), both direct and indirect enzyme linked immunosorbent assays (ELISA), and immunometric or "sandwich" assays.
One such infectious agent which can be detected by immunoassays is Chlamydia trachomatis (herein C. trachomatis) which is one of two microbial species of the genus Chlamydiaceae, order Chlamydiales. There are 15 or more strains of this species which are the causes of a number of human ocular and genital diseases including trachoma, inclusion conjunctivitis, lymphogranuloma venereum, nongonococcal urethritis and proctitis. Infection from C. trachomatis is pervasive in the general population so that it is believed that there are millions of cases each year of nongonococcal urethritis alone.
Gonorrhea is another disease usually transmitted by sexual contact, and is caused by a bacterium of the Neisseria genus, especially N. gonorrhoeae. The disease has plagued mankind for thousands of years, and although antibiotics have helped control its spread, it still persists in epidemic proportions in many parts of the world. The importance of detection and treatment of this organism is well recognized. N. meningitidis and N. lactamica are also species of considerable medical and diagnostic interest.
Because of the widespread nature of these diseases, there is considerable interest in having a rapid, simple and reliable test for detection of chlamydial and gonococcal organisms. Considerable research has been carried out to find useful ways to extract and detect antigens from chlamydial and gonococcal organisms.
Assays for C. trachomatis and N. gonorrhoeae carried out using a solid support are described in U.S. Pat. No. 4,497,899 and U.S. Pat. No. 4,497,900, respectively (both issued Feb. 5, 1985 to Armstrong et al and Abram et al, respectively). The described assays are performed by extracting antigen from the organism and coating it on a bare solid support. The coated antigen is then detected with either one or two antibodies, one of which is suitably labeled with an enzyme. The critical feature of the assays appears to be the use of a solid support for attachment which is untreated or uncoated with any biological material. Attachment of antigen is apparently achieved by incubating the coated support for an extended time sufficient to cause adsorption of antigen thereon. The absorption time is at least 30 minutes at elevated temperature (37.degree. C.). The entire assay described in U.S. Pat. No. 4,497,899 takes at least 3 hours to perform. A similar quicker assay is described in U.S. Pat. No. 4,497,900 for N. gonorrhoeae.
It would be desirable to have a much more rapid test for chlamydial or gonococcal organisms which has high reliability and can be performed at room temperature.
Such an improvement is described and claimed in copending U.S. Ser. No. 255,923 (filed Oct. 7, 1988 by Pronovost) now U.S. Pat. No. 5,075,220 (issued Dec. 24, 1991). It was found that ionically charged supports attract chlamydial or gonococcal antigen and enable one to quickly and sensitively detect such antigens. However, further improvements were needed for some biological specimens, especially those containing copious amounts of whole blood, mucus or components. Thus, the improvement described in copending U.S. Ser. No. 255,920 (filed Oct. 7, 1988 by Mauck) now U.S. Pat. No. 5,032,504 (issued Jul. 16, 1991) was made.
Despite the considerable improvements described in the copending applications noted above, there is a continued need to make the assay faster (that is, less than 20 minutes). It would be desirable to eliminate as many steps as possible from the earlier assay protocols so users would find the assays more convenient and suitable for prompt diagnosis and treatment of chlamydial and gonococcal infections. Moreover, the peroxidase-labeled antibody conjugate used in the known assays has a certain degree of stability (and thus, shelf life), but there is a need for additional stability and longer shelf life.
A highly rapid and accurate assay is described in more detail in copending U.S. Ser. No. 522,444 (filed on even date herewith by Mauck, Boyer, Warren III, Sprague and Snodgrass) and entitled "Use of Enzyme-Labeled Antibody Fragment in Determination of Chlamydial or Gonococcal Antigens". In this assay, increased rapidity of the assay is achieved because fewer steps are employed to detect the antigen. Moreover, an enzyme-labeled antibody F(ab').sub.2 fragment was found to be more stable than an enzyme-labeled whole antibody.
However, in developing that assay, which solved a number of problems with known assays, it was found that premature reaction of the enzyme-label (particularly, peroxidase) conjugated to antibody fragments produced unwanted background which obscured true positive signals in assays. This was particularly found to be a problem with the negative controls which were used to indicate whether the assay protocol was properly carried out. Although it is presently uncertain, it is speculated that the enzyme label on the antibodies may be involved in a reaction with residual substrate (that is, hydrogen peroxide when the enzyme is peroxidase) and phenolic electron transfer agents (such as 4'-hydroxyacetanilide) which are often used to enhance the rate of dye formation in the presence of the enzyme (see for example U.S. Pat. No. 4,828,983, issued May 9, 1989 to McClune). The result is unwanted dye formation.
Stable compositions of enzyme-labeled immunoreactants such as antibodies or antibody fragments are needed to provide rapid assays without undesirable background signal.

Use of heme-containing proteins as stabilizers for enzyme-labeled immunoreactants