Abstract: The present invention relates to a process for producing tetrahydrofuran polymer or tetrahydrofuran copolymer by using heteropolyacid catalyst, and more particularly, to a process for producing tetrahydrofuran polymer by using hydronium ion water having a pH of 5.5 or less as a reaction initiator in the initiation step.

Abstract: A plasma display apparatus and a method of driving the plasma display apparatus are provided. The plasma display apparatus includes a plasma display panel including a first electrode and a second electrode, a first electrode driver, and a second electrode driver. The first electrode driver supplies a first falling signal of a voltage magnitude, that is more than a voltage magnitude of a scan signal supplied during an address period, to the first electrode before the supply of a rising signal with a gradually rising voltage in at least one subfield of several subfields of a frame. The second electrode driver supplies a second signal having a polarity opposite a polarity of the first falling signal to the second electrode during the supply of the first falling signal.

Abstract: The present invention relates to hepatitis B virus (hereinafter it refers to HBV) polymerase containing a histidine tag, RNase H enzyme derived from HBV polymerase and processes for preparation thereof. More particularly, the present invention relates to recombinant HBV polymerase, its RNase H domain with enzyme activity, expression vectors producing the enzymes in E. coli and processes for preparing the HBV polymerase and the RNase H enzyme which can be easily purified due to their histidine tags. And the present invention relates to uses of the HBV polymerase and the RNase H enzyme for screening antiviral agents.

Abstract: The present invention relates to hepatitis B virus (hereinafter it refers to HBV) polymerase containing a histidine tag, RNase H enzyme derived from HBV polymerase and processes for preparation thereof.More particularly, the present invention relates to recombinant HBV polymerase, its RNase H domain with enzyme activity, expression vectors producing the enzymes in E. coli and processes for preparing the HBV polymerase and the RNase H enzyme which can be easily purified due to their histidine tags.And the present invention relates to uses of the HBV polymerase and the RNase H enzyme for screening antiviral agents.

Abstract: The present invention relates to novel terephthalamide derivatives and in particular to novel terephthalamide derivatives of the following formula 1, its pharmaceutically acceptable salts as antiviral agents having remarkable inhibitory actions against the proliferation of various viruses including HIV and HBV, and preparing method thereof ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are the same as defined in the detailed description of the present invention.