Abstract: Disclosed is a modified hyperthermophilic DNA ligase having improved DNA binding ability and reactivity. The modified hyperthermophilic DNA ligase has an amino acid sequence corresponding to the amino acid sequence of a heat-resistant DNA ligase derived from a thermophilic bacterium, a hyperthermophilic bacterium, a thermophilic archaebacterium, or a hyperthermophilic archaebacterium, except with at least two of charged amino acids in the C-terminal helix region each being substituted by alanine, threonine, or serine residues.

Abstract: Chirality distribution in the molecular structure of protein or the like and magnetic domain structure are analyzed with high resolution less than 10 nm. A transmission electron microscope equipped with a spin-polarized electron source is used for holography observation. The phase of transmission spin-polarized electrons changes due to the existence of chirality structure or magnetization in a sample, which is observed as an interference pattern phase shift in holography measurement.

Abstract: A multi-wire saw according to the present invention cuts a workpiece while supplying a slurry containing an alkali or mixed acid to a cutting interface between the workpiece and a wire, and includes: a storage tank with a heating mechanism for storing and heating the slurry; a thermal insulating pipe for transporting the slurry sent with a pump from the storage tank with a heating mechanism to a position before a position where the wire is incorporated into the workpiece, while keeping the slurry at a predetermined temperature; a thermostat for keeping a temperature in a vicinity of the workpiece fixed to a stage at the predetermined temperature; and a wire heating mechanism for heating the wire to the predetermined temperature. Consequently, the cutting resistance decreases during cutting machining of a silicon ingot, and the variation in the cutting resistance also decreases, whereby a high-quality wafer can be obtained at a high efficiency and a low cost.

Abstract: It is intended to obtain DNA ligase improved in binding ability and reactivity with DNA, particularly thermostable DNA ligase improved in binding ability and reactivity with DNA. The present invention provides a DNA ligase mutant improved in binding ability and reactivity with DNA, which is obtained by partially or completely deleting a C-terminal helix portion of DNA ligase. Particularly, the mutant is derived from a thermostable bacterium.

Abstract: A multi-wire saw according to the present invention cuts a workpiece while supplying a slurry containing an alkali or mixed acid to a cutting interface between the workpiece and a wire, and includes: a storage tank with a heating mechanism for storing and heating the slurry; a thermal insulating pipe for transporting the slurry sent with a pump from the storage tank with a heating mechanism to a position before a position where the wire is incorporated into the workpiece, while keeping the slurry at a predetermined temperature; a thermostat for keeping a temperature in a vicinity of the workpiece fixed to a stage at the predetermined temperature; and a wire heating mechanism for heating the wire to the predetermined temperature. Consequently, the cutting resistance decreases during cutting machining of a silicon ingot, and the variation in the cutting resistance also decreases, whereby a high-quality wafer can be obtained at a high efficiency and a low cost.

Abstract: In a slurry for cutting a silicon ingot according to the present invention, a content of a basic material is at least 3.5% by mass with respect to the total mass of a liquid component of a slurry, organic amine is contained in a mass ratio of 0.5 to 5.0 with respect to water in a liquid component of the slurry, and pH of the slurry is 12 or more. Furthermore, according to a method of cutting a silicon ingot according to the present invention, the above-mentioned slurry for cutting a silicon ingot is used at 65° C. to 95° C. Consequently, the cutting resistance during cutting processing of a silicon ingot is reduced, and a wafer of high quality can be obtained efficiently.