The effect of oligomer (M n =400-500 g/mol) on dye-sensitized solar cells (DSSC) employing polymer electrolytes consisting of poly(epichlorohydrin-co-ethylene oxide) (Epichlomer), LiI, 1-methyl-3-propylimidazolium iodide (MPII) and I 2 is investigated. Five kinds of oligomer, poly(ethylene glycol) (PEG, M n =400 and 1,000 g/mol), poly(ethylene glycol) dimethyl ether (PEGDME), poly(propylene glycol) (PPG) and poly(ethylene glycol) diglycidyl ether (PEGDGE), were introduced to elucidate the role of terminal groups and chain length. The coordinative interactions and structures of polymer electrolytes were characterized by FT-IR spectroscopy and X-ray diffraction (XRD). The improved interfacial contact between the electrolytes and the electrodes by the oligomer addition was confirmed using a field-emission scanning electron microscope (FE-SEM). The electrolytes exhibited ionic conductivities on the order of 10 −4 S/cm, but PEGDGE electrolyte showed much lower value (~10 −8 S/cm). As a result, the energy conversion efficiency of DSSC was significantly affected by the oligomer. For example, the DSSC employing PEGDME with methyl terminal groups exhibited 3.95% at 100 mW/cm 2 , which is 200-fold higher than that employing PEGDGE.

Structure of human blood coagulation factor VIII (FVIII) in relation to its activation process was investigated. FVIII was purified from a commercial FVIII concentrate by immunoaffinity chromatography and its dissociated subunits, heavy and light chains were isolated. The light chain (FVIII-L) was treated with thrombin or factor Xa (FXa) in order to cleave the peptide at Arg 1 6 8 9 or Arg 1 7 2 1 , respectively. Reassociation of FVIII-H with either of FVIII-L derivatives, F V I I I -L 72 (72 kDa) a n d F V I I I -L 6 5 (65 kDa) brought about the formation of heterodimers which have similar cofactor activity. The association constant of FVIII-H with FVIII-L 72 was about two-fold faster than that with FVIII-L 6 5 . Cleavage of major FVIII-H with thrombin generated two peptides with molecular weights of 50 kDa (A 1 ) and 40 kDa (A 2 ). Formation of heterotrimer by reassociation of A 1 , A 2 and FVIII-L 7 2 g e n e r a t e d FVIII cofactor activity, while the dimers formed from A 1 o r , A 2 with FVIII-L 7 2 had no activity, suggesting that both A 1 a n d A 2 are required for FVIII activity. Heterotrimers formed from A 1 and A 2 with either of F V I I I -L 7 2 or FVIII-L 65 in the presence of CaCl 2 ( 1 0 m M ) revealed cofactor activity, and they were dissociated into subunits with the loss of activity when EDTA (10mM) was added, indicating that the formation of heterotrimer, the functional unit of FVIII, from A1, A2 and FVIII-L is calcium dependent and that the cleavage of FVIII-L by FXa does not inactivate FVIII.Keywords: blood coagulation factors, factor VIII, protein processing InroductionCoagulation factor VIII (FVIII) participates in the activation of factor X (FX) by factor IX as a cofactor in the blood coagulation cascade, and its activation is accomplished by limited proteolysis of both heavy and light chains (Lollar et al., 1985;Mertens et al., 1985;Kaufman, 1992).Thrombin and FXa are known to be responsible for the activation of FVIII by cleavage of heavy and light chains. Due to the limited proteolysis by thrombin and FXa at the B domain of FVIII, FVIII heavy chain (FVIII-H) is heterogeneous (Andersson et al., 1986). Three major cleaving sites of FVIII by thrombin during activation are A r g 3 3 6 , Arg 7 4 0 and Arg 1 6 8 9 . FXa also cleaves at the same sites defined by thrombin and additionally, at Arg 336 in the heavy chain and at Arg 1721 in the light chain (Eaton et al., 1986). The additional cleavage at Arg 336 , Arg 1721 has been thought to inactivate FVIII with the dissociation of subunits. However, recent observation suggested that cleavage at Arg 1 7 1 9 or Arg 1 7 2 1 in the light chain may be unrelated to FVIII inactivation (Fay, 1993). Therefore inactivation of FVIII by additional cleavage by thrombin or FXa in the light chain remains controversial, and the precise sites of proteolytic cleavage of FVIII in the process of FVIII activation remains unclear.It is neccessary to define the role of each FVIII subunits in the generation of cofactor activity. In the present study, we attem...