A catalyst for purifying exhaust gases includes a heat resistant support, a porous layer coated on the heat resistant support, a noble metal catalyst ingredient loaded on the porous layer, and an NO.sub.x storage component including at least one member selected from the group consisting of alkaline-earth metals, rare-earth elements and alkali metals, and loaded on the porous layer. In the catalyst, the noble metal catalyst ingredient and the NO.sub.x storage component are disposed adjacent to ea...

A method for purifying an exhaust gas by simultaneously removing carbon monoxide, hydrocarbons, and nitrogen oxides contained in the exhaust gas, comprising bringing the oxygen rich exhaust gas into contact with an exhaust gas purifying catalyst comprised of at least one noble metal selected from the group consisting of platinum and palladium, at least one alkaline earth metal selected from the group consisting of barium, magnesium, calcium, and strontium, and at least one alkali metal selected ...

A method for purifying viruses from a cell line culture by chromatography, comprising an anion exchange chromatography step followed by a cation exchange chromatography step and optionally a metal-binding affinity chromatography step. The method is particularly suitable for producing viruses for use in vaccines.

The present invention provides a purification process of K-252a, which comprises: treating microorganism cells containing K-252a represented by formula (I): ##STR1## with an alkaline solution to convert K-252a into K-252b represented by formula (II): ##STR2## or alkali salts thereof, which are then released out of the cells, methylating K-252b or alkali salts thereof to convert them into K-252a again, and isolating and collecting the resulting K-252a.

An exhaust gas purifying catalyst including a carrier having a plurality of cells as exhaust gas passages, an HC adsorbent layer formed on the carrier of each of the cells, and an upper catalyst layer disposed on an upstream side of each of the exhaust gas passages on the HC adsorbent layer and a lower catalyst layer disposed on a downstream side of each of the exhaust gas passages on the HC adsorbent layer. The upper catalyst layer includes more O2-storage material than the lower catalyst layer...

Methods are provided for producing highly purified compositions of nucleic acids by using tangential flow ultrafiltration. A scaleable process for producing pharmaceutical grade plasmid DNA, useful for gene therapy, is provided, which is efficient and avoids the use of toxic organic chemicals.

Crude dihydrocarbylchlorothiophosphate product contaminated with dihydrocarbylpolysulfide and/or dihydrocarbylchlorophosphate is upgraded by treating the crude product with an aqueous hypochlorite solution, and separating an aqueous phase from the organic, then drying to obtain the resultant product.

The invention relates to a method of purifying cholera toxin using a matrix with at least one ion chosen from among matrix with Ni.sup.+2, Co.sup.+2, Cd.sup.2 or Zn.sup.+2 immobilized thereon. It is possible thereby to selectively elute the B subunit for cholera toxin from the matrix.

To provide an exhaust gas purifying system capable of forcibly regenerating DPF by efficiently raising the temperature of exhaust gas even when an exhaust gas temperature is very low at the time of low load and low engine speed such as an idling operation. In an exhaust purifying system (1) having an exhaust throttling valve (31) and a DPF (3) in an exhaust passage and having regeneration control means (P1) for regenerating the DPF (3), the regeneration control means (P1) is provided with an exh...

A catalyst comprises an HC trapping material that is capable of trapping HC in an exhaust gas under low temperatures and releasing HC with a raise in temperature and catalytic material containing a Ce--Pr double oxide capable of oxidizing and purifying HC from the HC trapping material with a high efficiency.