The absorption spectra of Pd(niox)2, Pd(dmg)2 and Pd(dpg)2 have been studied at high pressures. The absorption bands based on the 4dz2-5pz transition shifted rapidly to longer wavelengths with increasing pressure. The mean rates of the red shift with pressure were ca. -1170cm-1/GPa for Pd(niox)2, ca. -1300cm-1/GPa for Pd(dmg)2 and ca. -1990cm-1/GPa for Pd(dpg)2. A new pressure-induced absorption band at around 410nm was observed for Pd(niox)2 above 10GPa. The electronic states of the palladium complexes are discussed. The colors of the complexes in the diamond-anvil pressure cell were observed visually at various pressures. The colors of the complexes turn from yellow to orange and then to successive colors in the visible spectrum with increasing pressure. These materials can be utilized as a pressure indicator over the wide pressure range.
The composition of melt formed by equilibrium partial melting of peridotite at high pressures using a new experimental method is described. A thin layer of diamond powder or a small loosely sintered diamond chip is andwiched between finely ground peridotite and heated to partially melt the host peridotite at high pressures. Melt formed by partial melting of peridotite segregates and migrates into the pore space between diamond grains. The melt equilibrates with the host peridotite only after the pore sp ace iscompletely filled with melt. Microprobe analysis of segregated quenched melt trapped between diamond grains can be made without problems involving quenching or overgrowth of coexisting crystals. Melt which fills the pore space of the diamond grains is equilibrated with residual solids within 24 hours at 1400°C in the synthetic system Mg2SiO4-NaAlSiO4-SiO2 at 10, 15 and 20kbar. This method can be applied to determine both compatible and incompatible elements in melt formed by partial melting of peridotite or any other rocks at high pressures. Using this method the compositions of melts formed by partial melting of a spinel lherzolite were determined at pressures between 10 and 20kbar.
Direct transfer of membrane proteins of B16 melanoma cell to lecithin liposome has been tried in two different cell culturing methods; namely, monolayer and suspension culture systems. For this purpose an appropriate amount of an artificial boundary lipid, 1, 2-dimyristoylamido-1, 2-deoxyphosphatidylcholine (DDPC), was added to 1, 2-dimyristoylphosphatidylcholine (DMPC) liposome. An increase in the amount of DDPC to DMPC led to an increase in both the total amount and the kind of proteins transferred from the cell to the liposome. In addition, the amount and kind of proteins were differred also by altering the method of cell culture. These results indicate that the location and the mobility of the proteins in cytoplasm membrane are largely affected by the situation of the cells whether the cell adheres on a substrate or suspends in a medium.
Embryonic diapause of the silkworm, Bombyx mori, is induced by a neuropeptide, diapause hormone (DH), which is secreted from suboesophageal ganglion (SG). cDNA clones for diapause hormone were isolated from a cDNA library constructed from poly A+ RNA of SG. Sequencing from 5'-end to 272 by revealed that the cDNA encodes the DH sequence which is identical to the previously isolated natural peptide except for one amino acid. The 19th amino acid of the DH deduced from the cDNA was Trp instead of Cys in the sequence of the peptide isolated previously (Bom DH-I [19-Cys]). This sequence was found in the DH preparation recently isolated from SGs of day 2 to 3 pupae of B. mori. A synthetic peptide amide with Trp at 19 exhibited biological activity comparable to the peptide amide with Cys at 19. Thus, the amidated 24 amino acid peptide with Trp at 19 is concluded to be a new diapause hormone molecule and named BomDH-I [19-Trp].