Lipase-catalyzed resolution of 1-hydroxymethyl-2-methylferrocene

±-1-Hydroxymethyl-2-methylferrocene was optically resolved by transesterification with lipases using vinyl esters such as vinyl butyrate, vinyl caproate, vinyl octanoate and vinyl decanoate, as acyl donors.     

Expression of the mutant (1735T-DEL) tissue-nonspecific alkaline phosphatase gene from hypophosphatasia patients

Hypophosphatasia (HOPS) is an inherited disorder characterized by defects in skeletal mineralization due to the deficiency of tissue-nonspecific alkaline phosphatase (TNSALP). To date, various mutations in the TNSALP gene have been identified. Especially, a deletion of T at position 1735 (1735T-del) located in exon 12 has been detected in three genetically unrelated Japanese patients, which seems to be one of the hot spots among the causative mutations in Japanese HOPS patients. 1735T-del causes a frame shift downstream from codon 503 (Leu), and consequently the normal termination codon at 508 is eliminated. Since a new inframe termination codon appears at codon 588 in the mutant DNA, the resultant protein is expected to have 80 additional amino acids. Expression of the mutant TNSALP gene using COS-1 cells demonstrated that the protein translated from the mutant 1735T-del had undetectable ALP activity, and its molecule size was larger than normal, as expected. Interestingly, an immunoprecipitation study of patients' sera using antibody against TNSALP revealed an abnormal protein which corresponded in size to the mutated TNSALP expressed by COS-1 cells, suggesting that the abnormal TNSALP is made by HOPS patients. The detection of TNSALP in cells transfected with 1735T-del using an immunofluorescent method exhibited only a faint signal on the cell surface, but an intense intracellular fluorescence after permeabilization.     

A real-time motion estimation and compensation LSI with wide searchrange for MPEG2 video encoding

This paper presents a motion estimation and compensation large scale integration (LSI) for the MPEG2 standard. An embedded RISC processor and special hardware modules enable the LSI to achieve a sufficient ability to perform real-time operation and provide the availability to realize many kinds of block matching algorithms. Using a three-step hierarchical telescopic search algorithm, a single chip accomplishes real-time motion estimation with search ranges of ±32.5×±32.5 pixels for motion vectors. The chip was fabricated using 0.5-μm CMOS technology and has an area of 16.5×16.5 mm² and 2.0 M transistors     

High-Temperature Strength of Melt-Infiltrated SiC-Mo(Al,Si)2 Composites

High-temperature fracture behavior of melt-infiltrated SiC-Mo(AI,Si)₂ composites was studied. The composites exhibited moderate strength up to ∼1600°C under a fast loading rate. The softening of the Mo(Al,Si)₂ phase determined dominantly the temperature over which the strength decreased. The composite with finer microstructure revealed a higher level of strength over the whole temperature range. At 1580°C, however, the composites revealed distinct strength degradation at a reduced loading rate.     

Reaction of amines with conjugated olefins using lithium naphthalenide in non-ethereal solvents

It was found that lithium naphthalenide can be prepared from metallic lithium cuttings and naphthalene in non-ethereal solvents, such as benzene–N,N,N′,N′-tetramethylethylenediamine (TMEDA) or benzene-N,N,N′,N′-tetramethyldiaminopropane (TMDAP), under ultrasonic irradiation. Secondary amines reacted with conjugated olefins, such as isoprene or myrcene, using lithium naphthalenide in such non-ethereal solvents to give allylic amines. The yields of products were higher than in the reaction using lithium naphthalenide in tetrahydrofuran. From diethylamine (I) and isoprene (II), a mixture of N,N-diethyl-3-methyl-2-butenylamine (IV) and N,N-diethyl-2-methyl-2-butenylamine (V) (IV:V = 79:21) was obtained in 77% yield, and from diethylamine (I) and myrcene (III), N,N-diethylgeranylamine (VI) and N,N-diethylnerylamine (VII) (VI:VII = 88:12) were produced in 72% yield. These terpenic amines, VI and VII, are used as starting compounds for the preparation of perfumery materials.     

Production of horse radish peroxidase by plant cell culture

Calluses were induced from the stem and the root tissues of horse radish plantlets. Cell aggregate selections were carried out on them to obtain a cell line with higher peroxidase activity, and the isozyme patterns of the peroxidases from the cultured cells and their utility values as a clinical diagnostic reagent were investigated. The repetition of the cell aggregate selection resulted in increases in peroxidase activities in each generation of selection; about eleven fold in the 13th generation of selection from the stem tissues and about nine fold in the 13th generation from the root tissues. One of the cell lines (N5K6-S), originally derived from the stem tissues, after selectin showed a tenfold increase in peroxidase activity within two weeks of culture in a liquid medium. The value as a clinical diagnostic reagent of peroxidases extracted from the N5K6-S cells was estimated to be equivalent to those already commercially available for the same purpose. There were significant differences in the isoenzyme patterns of the peroxidases from root tissues and those from cultured cells. From these results, the possibility of commercial production of peroxidase utilizing plant tissue and cell culture techniques was discussed.     

High-temperature deformation and fracture behaviour of Cu-SiO2 bicrystals

Bicrystals of CU-SiO₂ dispersion-hardened alloys and of pure copper were tensile tested at various temperatures between 450 and 1050 K at a strain rate of 1.5 x 10^–4 sec^–1. In the case of pure copper bicrystals, elongation to fracture did not depend significantly on temperature and the fracture mode was invariably transgranular up to 850 K. On the other hand, the ductility of CU-SiO₂ bicrystals decreased with increase in temperature and the transition in the fracture mode from transgranular to intergranular occurred at around 450 K. SiO₂ particles on grain boundaries play an important role on intergranular fracture by suppressing grain-boundary sliding and also on the retardation of recrystallization during deformation. Two types of Cu-SiO₂ bicrystals having different crystal orientation relationships show quite different deformation and fracture behaviour. This can be explained in terms of the contribution of lattice dislocations to the grain-boundary sliding.     

Preparation of copolymer of styrene with hemin and its functional property as cyanide ion exchanger

Summary Copolymers of hemin and styrene with different hemin contents were prepared by radical polymerization, using pyridine as the solvent and ,-azobisisobutyronitrile as the initiator. It was found that the obtained copolymers are insoluble in aqueous solvents and have function as cyanide ion exchanger.     

Efficient production of Cre-mediated site-directed recombinants through the utilization of the puromycin resistance gene, pac: a transient gene-integration marker for ES cells

Gene targeting in embryonic stem (ES) cells is a powerful tool for generating mice carrying specifically designed mutations in the germline. Puromycin can completely kill ES cells within 24 to 48 h whereas G418 and hygromycin cannot. We have, therefore, proposed that the puromycin N-acetyltransferase ( pac ) gene, may be utilized as a transient gene-integration marker. Using a circular expression vector of cre and pac genes, Cre-mediated mutant cells were effectively enriched by pulse treatment of puromycin without stable integration of their genes. We have thus demonstrated the first application of pac as a transient gene-integration marker for ES cells.