Abstract: A high manganese duplex stainless steel with excellent hot workability, comprising (in weight %): less than 0.1% of C; 0.05-2.2% of Si; 2.1-7.8% of Mn; 20-29% of Cr; 3.0-9.5% of Ni; 0.08-0.5% of N; less than 5.0% of Mo and 1.2-8% of W, alone or composite; the balance Fe and inevitable impurities; and a method for manufacturing the duplex stainless steel, comprising the steps of: solution heating the duplex stainless steel composition at a temperature of 1,050 to 1,250° C., hot working at a starting temperature of 1,130 to 1,280° C. and then ending at a temperature greater than 1,000° C., and then cooling within the temperature range from 1,000 to 700° C. at a cooling rate of more than 3° C./min. The duplex stainless steel exhibits a reduction in area of more than 50% at 1,050° C., and possesses a yield strength of more than 400 MPa, and a corrosion rate of less than 0.36 mm/year, after solution heating.

Abstract: A method for detecting or measuring homocysteine in a sample includes the steps of (a) reacting a D-amino acid present in a sample with a D-amino acid converting enzyme to convert the D-amino acid into a substance that does not serve as a substrate of D-amino acid oxidase or D-amino acid acetyltransferase; (b) reducing homocysteine in the sample with a thiol compound; (c) reacting the reduced homocysteine with a methyltransferase and a methyl donor to newly produce D-amino acid; and (d) reacting the produced D-amino acid with the D-amino acid oxidase or the D-amino acid acetyltransferase in the presence of an SH reagent to produce hydrogen peroxide, and color-developing the produced hydrogen peroxide by using an oxidative color-developing agent.