Abstract: Large comb-type branched polynucleotides useful as amplifier molecules in nucleic acid hybridization assays are provided, the polynucleotides comprising: a polynucleotide backbone having at least about 15 multifunctional nucleotides, each of which defines a sidechain site and a first single-stranded oligonucleotide unit that is capable of binding specifically to a first single-stranded polynucleotide sequence of interest; and pendant polynucleotide sidechains extending from said multifunctional nucleotides each comprising iterations of a second single-stranded oligonucleotide unit that is capable of binding specifically to a second single-stranded polynucleotide sequence of interest, the total number of iterations in all sidechains being at least 20. Methods of making these polynucleotides are also provided.

Abstract: The present invention relates to a method for the production of N-vinyl-2-pyrrolidone with high selectivity. The method is characterized in subjecting 2-pyrrolidone and acetylene to vinylation by using hydroxy end-capped ether oligomers having a molecular weight less than 1000 or linear diols having at least 4 carbon atoms as co-catalysts under the catalyzation of alkali metal salts. At a vinylation temperature of 100.degree.-200 .degree. C., a reaction pressure of 7.5-30 atm and a reaction time period of 3-20 hours, N-vinyl-2-pyrrolidones are obtained with yields above 90%.

Abstract: Novel oligonucleotide probes are provided having the structure ##STR1## wherein: R.sup.2 is lower alkyl; R.sup.3 is C.sub.1 -C.sub.12 alkylene containing 0 to 6 linkages selected from the group consisting of --O--, --S-- and --NR.sup.12 -- wherein R.sup.12 is hydrogen or lower alkyl; R.sup.5 is hydrogen or lower alkyl; R.sup.6 is selected from the group consisting of hydrogen, methyl, bromo and iodo; R.sup.7 is C.sub.1 -C.sub.12 alkylene containing 0 to 6 linkages selected from the group consisting of --O--, --S-- and --NR.sup.12 --, and bound to R.sup.8 through an --O--, --S-- or --NR.sup.12 -- moiety; and R.sup.8 is a protecting group that can be removed and replaced, without affecting the remainder of the compound, by reduction with a reducing agent. Methods for using the probes are provided as well.

Abstract: Novel N-4 modified pyrimidine analogs are provided having the structure (I) or (II) ##STR1## wherein: R.sup.1 is selected from the group consisting of hydrogen, acid-sensitive, base-stable blocking groups and acyl capping groups; R.sup.2 is lower alkyl; R.sup.3 is C.sub.1 -C.sub.12 alkylene containing 0 to 6 linkages selected from the group consisting of --0--, --S-- and --NH--; R.sup.4 is ##STR2## in which R.sup.9 is hydrogen or an optionally substituted aliphatic group; R.sup.10 and R.sup.11 are hydrocarbyl or together form a mono- or polyheterocyclic ring; R.sup.5 is hydrogen or lower alkyl; R.sup.6 is selected from the group consisting of hydrogen, methyl, bromo and iodo; R.sup.7 is C.sub.1 -C.sub.12 alkylene containing 0 to 6 linkages selected from the group consisting of --O--, --S-- and --NR.sup.12 -- wherein R.sup.12 is hydrogen or lower alkyl; and R.sup.8 is a protecting group that can be removed and replaced by reduction.

Abstract: The present invention relates to a method for the production of N-vinyl-2-pyrrolidone by gas-phase reaction at atmospheric pressure. The method is characterized in that a gas-phase reaction is conducted by using N-.beta.-Hydroxyethyl-2-Pyrrolidones serving as raw materials, at a temperature of 300.degree.-450.degree. C., a space velocity of 500-4500 hr.sup.-1 in the presence of a mixed oxide of group IV elements, or an oxide of group IV elements, which has been modified by group I or group II elements.

Abstract: A nucleic acid test article can be used to detect a targeted nucleic acid found in a specimen. The test article includes a substrate having two opposing surfaces and a water-insoluble nucleic acid probe attached in a distinct zone of one of the surfaces. The probe is prepared from a water-insoluble particle to which is covalently attached an oligonucleotide which is complementary to the targeted nucleic acid. Substantially none of the probe is embedded within the surface of the substrate. Particularly useful test articles have a multiplicity of water-insoluble probes located in distinct zones on one of the substrate surfaces. These probes are useful for the detection of a multiplicity of targeted nucleic acids, particularly after amplification by polymerase chain reaction.

Abstract: This invention deals with the problem of an error voltage in a MOSFET analog switch sample and hold circuit caused by the turn off charge in the MOSFET analog switch. The invention provides a compensating circuit which can be adjusted to exactly compensate for the turn off charge which causes the error so that the error can be reduced to zero or nearly zero. The compensating circuit can be used in both open loop and closed loop sample and hold circuits. The compensating circuit can be used in combination with a Miller feedback circuit for eliminating the error voltage.

Abstract: A removal device for an electrostatic precipitator which includes an ion generator, precipitator, collector and removal device for removing particles in the precipitator. A plurality of scrapers capable of linear displacement between two adjacent electrostatic plates of opposite polarities remove particles adhered thereto and scraped particles are collected in the collector for subsequent handling.

Abstract: An electrostatic precipitator including an ionization unit for ionization to charge the oily dust particles in the air flowing therein at the front, a dust precipitating unit for catching the charged oil dust particles in the air flowing from the ionization unit thereinto at the front and out therefrom at the back by means of an electrostatic field produced from a plurality of large and small electric plates reversed in conductivity, a plurality of scrapers respectively mounted in between respective two adjacent large and small electric plates for scraping away the oily dust particles precipitated on the large and small electric plates, and a collecting unit located underneath the dust precipitating unit for collecting the oily dust particles scraped away by the scrapers.

Abstract: An impact absorber for an automobile bumper comprises a housing and a pair of cylinders arranged in the housing. A third cylinder having two openings at its ends is parallelly disposed between the pair of cylinders such that two gaps are defined by the walls of the pair of cylinders, the third cylinder and the housing. Apertures are formed through the walls of the pair of cylinders facing each other adjacent one end of each of the pair of cylinders for expelling damping liquid from the pair of cylinders into the gaps upon movement of the pistons in the pair of cylinders for damping the impact force. The pressure of damping liquid in the gaps forces two pistons within the third cylinder to move toward each other thereby compressing a coil spring mounted between the two pistons for further damping the impact force. The compressed air between the two pistons within the third cylinder escapes from an aperture formed through the walls of the third cylinder and the housing.

Abstract: Oligonucleotides derivatized to incorporate horseradish peroxidase (HRP) are useful in diagnostic methods and provide significant advantage over radioactively labeled oligonucleotide probes. The HRP-derivatized oligonucleotides can be easily and efficiently prepared by reacting a sulfhydryl containing oligonucleotide with a conjugate of a mal-sac-HNSA ester and HRP under mild and easily controlled reaction conditions.

Abstract: Oligonucleotide functionalizing reagents are disclosed which are useful in introducing sulfhydryl, amino and additional hydroxyl groups into oligonucleotides. The reagents are substantially linear in structure, at one end provided with a phosphoramidite moiety, at an opposing end provided with a sulfhydryl, amino or hydroxyl moiety, the two ends linked through a hydrophilic spacer chain. Methods of using and synthesizing the novel reagents are disclosed as well.

Abstract: Apparatus for immunoassay of multiple samples of biological fluids (e.g., AIDS antibodies), the apparatus being capable of mounting for rocking during incubation. A frame receives plural test vessels so that the vessels are interconnected for circulation through all the vessels of buffers, de-ionized water and air and for discharge of waste. Each vessel is transparent and contains nitrocellulose test paper impregnated with antigens to the antibodies. Valved ports in each vessel accept sequential insertion of the biological fluids, an enzyme conjugate and color developer. Color changes in the individual test papers are observed through the transparent vessels and identify presence of antibodies in the samples.