Porous materials prepared by heating derivatives from halloysite

Halloysite clay was subjected to serious treatment by trimethylsilylation and hydrochloric acid. The resulting derivatives were heated below 1473 Kin nitrogen or air to prepare thermally stable porous materials including larger pores than those in zeolite. The trimethylsilylated halloysite resulted in a thermally stable porous material, in an amorphous state, including extremely uniform pores of 1.7 nm. Another derivative also resulted in a thermally cable porous material but consisted of very heterogeneous pores. The thermal degradation behaviour of both derivatives is discussed in detail.     

The effect of endotoxin on the neutrophil chemiluminescence in the rabbit

To examine the effects of endotoxin on the neutrophil function, neutrophil-dependent microbicidal activities were evaluated by the chemiluminescence (CL) method in rabbits injected with endotoxin. Six rabbits in the first group were administered saline intravenously as control. Ten rabbits each in the second and third group received endotoxin 0.7 microgram.kg-1 and 70 micrograms.kg-1 respectively. Luminol-dependent CL in whole blood (whole blood CL) and in isolated neutrophils (neutrophil CL) were examined before administration and 30, 60, 180 and 360 min after administration. Peak values of whole blood CL in the second group were significantly depressed at 30 and 60 min, and elevated at 360 min. Those in the third group were depressed more than in the second group at all times after endotoxin administration. Peak values of neutrophil CL in the second group at 180 and 360 min were significantly elevated, but those in the third group at 30, 60, 180 min were markedly depressed. Experiments combining neutrophils and pooled plasma revealed that these CL responses were associated with the neutrophils themselves. It is speculated that the neutrophil suppression observed in the third group was caused by the overactivation of neutrophils induced by the activated complements and some other stimulating factors, and/or may be due to the abundant appearance of immature granulocytes with lesser activities.     

Plant service continuance approach through periodical examination

The plant aging issue includes the following: (1) fatigue damage, (2) neutron irradiated embrittlement, and (3) thermal embrittlement. When the service of nuclear power plant is intended to lost beyond the pre-scheduled service years, it is necessary to develop methods by which the degree of material aging degradation is properly predicted. The development of an aging prediction system and the establishment of a requalification method of damage component are like the two wheels of a vehicle. When this aging prediction system is effectively applied to the actual plant through ISI, structural integrity assessment will include the aging effects. In the following, the outlines of the advanced periodical examination including the material aging detection is discussed in view of the plant service continuation through examination.     

Influences of particle size of metal on catalytic graphitization of non-graphitizing carbons

It is known that addition of certain metals or inorganic compounds into carbon accelerates the graphitization process at elevated temperature through formation of graphitic carbon. Recently, however, it became apparent that some other kinds of catalytic graphitization effects result from varying the particle size of metal catalysts. Studies on this subject are summarized.     

Enzyme-linked immunosorbent assay of carbamoylphosphate synthetase I: plasma enzyme in rat experimental hepatitis and its clearance

Carbamoylphosphate synthetase I (CPS I), a urea cycle enzyme, is located almost exclusively in the mitochondria of hepatocytes. The enzyme is unique in that it constitutes about 2-6% of total liver protein and is composed of a large subunit of 160 kD. We developed a sensitive enzyme-linked immunosorbent assay (ELISA) for measurement of the enzyme in plasma using an antibody against the rat enzyme. In galactosamine-induced rat acute hepatitis, plasma concentration of CPS I that was 1-2 micrograms/ml blood before the treatment, increased up to 125 micrograms/ml blood in 24 h after the treatment and decreased to a near control level in 72 h. Plasma concentration of ornithine carbamoyl-transferase (OCT), another urea cycle enzyme, reached a maximum in 24 h and then decreased a little more rapidly than that of CPS I. On the other hand, alanine aminotransferase activity reached a maximum in 36 h and decreased to a normal level in 96 h. In immunoblot analysis, the native CPS I polypeptide of 160 kD and its fragments of 140 and 125 kD were detected 24-48 h after the treatment. When purified rat CPS I and bovine OCT were injected intravenously into rats, the enzymes disappeared from blood roughly exponentially with apparent half-lives of about 67 and 18 min, respectively. Development of an ELISA for human CPS I and determination of the serum enzyme in various liver diseases remain to be performed.     

Lithographyless ion implantation technology for agile fab

A new type of ion implanter developed for an agile fab can eliminate the processes concerned. with photoresist lithography from the ion implantation process. This new ion implantation technology can reduce the raw process time, footprint, and the cost of ownership to less than one-half that of conventional ion implantation technology. The authors are making further developments on this ion implanter and evaluating technical issues related to ion implantation. This technique is suitable for manufacturing submicron node IC devices. Based on the results of evaluating the prototype machine, we will produce the next /spl beta/-machine.     

Factors governing the solubility of mesophase into pitch distillate

To explain the dissolution phenomena of mesophase into pitch distillate, the hydrogen donor ability of the distillate and the acceptor ability of the mesophase were examined using ¹H n.m.r. The mixtures which consisted of 9,10-dihydroanthracene(9,10-DHA) and mesophase samples or organic compounds(9,10-DHA/mesophase or organic COMPOUND = 1/5wt/wt) were heated at 618K for 1 h in sealed glass tubing, and then measured by ¹H n.m.r. The acceptor ability (Aa) of the mesophase was evaluated from the integrated intensity ratio between two peaks at 8.4 and 3.9 ppm, attributable to the resulting anthracene and the remaining 9,10-DHA, respectively. The solubility of a combination of mesophase and a distillate decreased with decreasing (Da + Aa) value, in which Da is the hydrogen donor ability of the distillate.     

Arabidopsis β1,2-xylosyltransferase: substrate specificity and participation in the plant-specific N-glycosylation pathway

β1,2-Xylosyltransferase (XYLT) is a plant-specific glycosyltransferase that contributes to the biosynthesis of N-glycoproteins in plants. However, the specificity of XYLT for N-glycans has not yet been completely clarified. To gain insights into the function of XYLT in the plant N-glycosylation pathway, we examined the acceptor substrate specificity of recombinant Arabidopsis XYLT (AtXYLT) using 2-aminopyridine-labeled N-glycans as the substrates and confirmed the N-glycans of Arabidopsis xylt mutant. Recombinant AtXYLT expressed in insect cells required the β1,2-linked N-acetylglucosamine (GlcNAc) residue at the nonreducing terminus of the α1,3-branched mannose (Man) residue (GlcNAcβ1,2-Manα1,3-Man; GNM3B) for activity. However, AtXYLT showed decreased activity with substrates that contained α1,3-fucose at the chitobiose core-GlcNAc or a terminal GlcNAc at the α1,6-branched Man residue of GlcNAcβ1,2-Man (GlcNAcβ1,2-Manα1,6-Man; GNM3A), whose ratios were 10% and 50% of the optimal substrate, GNM3B, respectively. Moreover, AtXYLT did not show any activity in the transfer of the Xyl residue to N-glycans that contained a mammalian-type β1,4-linked galactose (Gal) residue at the nonreducing terminus of GlcNAcβ1,2-Man. These results indicate that a β1,2-linked GlcNAc residue at the nonreducing terminus of an α1,3-branched Man residue is necessary for AtXYLT activity and that mammalian-type β1,4-linked Gal residue(s) on the same branch completely inhibit(s) the activity. Furthermore, N-glycan analysis showed that approximately 30% of the N-glycans carry the Xyl residue in the wild type. These findings suggest that AtXYLT acts on protein-bound N-glycans prior to α1,3-fucosyltransferase and mannosidase II in planta.     

Melt fracture behavior of polypropylene‐type resins with narrow molecular weight distribution. I. Temperature dependence

Polypropylene (PP)‐type resins with narrow molecular weight distribution, such as PP‐type thermoplastic elastomer PER and controlled‐rheology PP (CRPP) made by peroxide degradation of high molecular weight PP, have a problem of easy generation of skin roughness at extrusion. To examine the present state, the occurrence of skin roughness in PER and CRPP at extrusion was investigated with a capillary rheometer in a shear rate range of 12–6100 s^?1 and a temperature range of 180–280°C. A homo‐PP (HPP) and a block‐PP (BPP) with usual molecular weight distributions were used for comparison. HPP and BPP with usual molecular weight distributions show smooth extrudates at low shear rates and abruptly generate severe skin roughness “elastic failure” originating at the die entrance at a higher shear rate. PER and CRPP with narrow molecular weight distributions easily generate “sharkskin” melt fracture originating at the die exit, from a shear rate nearly one decade lower than rates of elastic failure of HPP and BPP. The sharkskin becomes more severe, with increasing shear rate, and attains to the elastic failure. The critical shear rate at which sharkskin occurs increases with increasing extrusion temperature. The critical shear rate is about 20 s^?1 at 180°C and about 120 s^?1 at 280°C, which is in the range encountered by the molten resin at extrusion processing. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2111–2119, 2002