Temperature-sensitive mutation in PEX1 moderates the phenotypes of peroxisome deficiency disorders

The peroxisome biogenesis disorders (PBDs), including Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD), are autosomal recessive diseases caused by deficiency of peroxisome assembly as well as malfunction of peroxisomes, where >10 genotypes have been reported. ZS patients manifest the most severe clinical and biochemical abnormalities, while those with NALD and IRD show the least severity and the mildest features, respectively. PEX1 is the causative gene for PBDs of complementation group I (CG1), the highest incidence PBD, and encodes the peroxin, Pex1p, a member of the AAA ATPase family. In the present work, we found that peroxisomes were morphologically and biochemically formed at 30 but not 37 degrees C, in the fibroblasts from all CG1 IRD patients examined, whereas almost no peroxisomes were seen in ZS and NALD cells, even at 30 degrees C. A point missense mutation, G843D, was identified in the PEX1 allele of most CG1 IRD patients. The mutant PEX1, termed HsPEX1G843D, gave rise to the same temperature-sensitive phenotype on CG1 CHO cell mutants upon transfection. Collectively, these results demonstrate temperature-sensitive peroxisome assembly to be responsible for the mildness of the clinical features of PEX1 -defective IRD of CG1.     

Effects of molybdenum,phosphorus and microstructure on creep properties

The effects of molybdenum, phosphorus and of microstructure on creep were studied at 550°C utilizing the model alloys Fe—3 Cr—0.05P, Fe—3 Cr—1 Mo—0.05P and Fe—3 Cr—1 Mo. The heat treatments were varied to obtain a ferritic or bainitic structure, the effect of a preheat treatment of 300 h at 550°C was investigated. Both Mo and P increase the creep strength by different mechanisms which lead to four types of creep curves, with 1 to 3 minima. The results are discussed using microstructural information from transmission electron-microscopy.     

Correction by gene expression of biochemical abnormalities in fibroblasts from Zellweger patients

Zellweger syndrome is a prototype of peroxisomal biogenesis disorders and a fatal autosomal recessive disease with no effective therapy. We identified nine genetic complementation groups of these disorders, and mutations in peroxisome assembly factor-1 (PAF-1) and the 70-kD peroxisomal membrane protein (PMP70) genes have been detected by our group F and Roscher's group 1, respectively. We now describe permanent recovery from generalized peroxisomal abnormalities in fibroblasts of a Zellweger patient from group F, such as biochemical defects of peroxisomal beta-oxidation, plasmalogen biosynthesis, and morphologic absence of peroxisomes, by stable transfection of human cDNA encoding PAF-1. In the light of these observations, we designed a gene expression system using fibroblasts from patients with peroxisomal biogenesis disorders. In Zellweger fibroblasts obtained from Roscher's group 1 and transfected with human cDNA encoding PMP70, peroxisomes were not morphologically identifiable, and peroxisomal function did not normalize.     

Ti-Containing Silsesquioxane Gels with Tunable Porosity: Preparation and Catalytic Activity for the Epoxidation of Cyclooctene by Aqueous Hydrogen Peroxide

Novel Ti-containing silsesquioxane gel catalysts were prepared by the hydrosilylative condensation of Ti-containing silsesquioxanes together with cubic silsesquioxanes and spherosilicates. The porosity of gels was controlled by changing the composition and the mixing order of the starting materials. Both porous and nonporous gels were found to act as excellent heterogeneous catalysts towards the selective epoxidation of cyclooctene by the use of aqueous hydrogen peroxide as an oxidant.     

An interpretation of ductile fracture process of uncrosslinked polymers in the rubbery state

The weak network theory previously developed is applied to explain the failure envelope for the ductile fracture of uncrosslinked amorphous polymers in a constant rate of elongation, with the assumption that the reformed chain requires a lapse of time after its reformation to contribute to maintenance of the network structure. The chain that contributes to maintain the structure is called the ‘structure chain’. The criterion is used that the fracture occurs provided the apparent average force per one ‘structure chain’ reaches a certain critical value. The result agrees well with the failure envelope obtained experimentally.     

The sign of Leser-Trelat associated with esophageal carcinoma

A 79-year-old woman was admitted to our hospital with complaints of dysphagia and multiple verrucous papules that had developed over the previous year. The diagnosis of esophageal carcinoma was based on upper gastrointestinal radiography and endoscopic examination with biopsy. The clinical syndrome was consistent with the sign of Leser-Trelat associated with esophageal carcinoma. Although radiation therapy and chemotherapy were undertaken, the patient died 8 months later because of the sign of Leser-Trelat in association with squamous cell esophageal carcinoma.     

Immunoglobulin-secreting cells in healthy peripheral blood mononuclear cells

Immunoglobulin-secreting cells were measured in healthy uncultured peripheral blood mononuclear cells (PBMCs) in vitro. The percentage of IgM-, IgG- and IgA-secreting cells in adult PBMCs was 0.053, 0.099 and 0.065%, respectively. The percentage of IgM-, IgG- and IgA-secreting cells was 0.73, 5.2 and 3.8% of surface IgM-, IgG- and IgA-bearing cells, respectively. The numbers of IgM-, IgG- and IgA-secreting cells increased with age in childhood. However, the numbers of all three classes were slightly decreased in adults compared with children aged 9-15 years. These results may explain the difference in immunity in vivo.     

Effects of boron on the creep properties,phosphorus segregation behaviour,and stress relief cracking susceptibility of 1.5% Cr–0.5% Mo steels

The effects of 25 ppm boron and of 0.05% phosphorus on the creep behaviour at 550 °C and on the fracture temperature in the constant load fracture test were tested for a 1.5% Cr–0.5% Mo steel. B and P decrease the creep strength, the rupture elongation is increased by B. B and P lower stress relief cracking susceptibility, however, it is increased at low stress. In the B doped material the rate of P grain boundary segregation is accelerated and the level of equilibrium segregation is somewhat higher, the equilibrium segregation is somewhat lower in the bainitic than in the martensitic structure.     

无图形损伤的选择性去除微小尘粒的湿法清洗技术

The drastic shrinking of semiconductor linewidths has led to a need for new wafer cleaning strategies in the FEOL. For past technology generations, particle removal has been accomplished typically using the SC 1 (NH4OH/H2O2/H2O) solution in conjunction with megasonic energy in a wet bench, or by DI water with a high pressure jet or megasonic nozzle in a wafer scrubber. However, such techniques have been found to damage patterns, particularly narrow polysilicon gate lines. Furthermore, the etching of oxide associated with SC 1, which facilitates particle removal by an undercutting mechanism, has recently become a concern due to increasingly strict oxide budgets. An alternative technique using an atomized liquid spray nozzle on a single wafer platform is proposed. Small droplets are able to effect particle removal without damage to sensitive patterns, by control of their carrier gas (N2) flow rate. Mechanisms for particle removal will be discussed.Results using this technique show particle removal comparable to megasonics can be achieved. Furthermore, 90 nm and 65 nm polysilicon gate structures were processed with high particle removal efficiency and no damage, as were A1 lines. Effects of the N2 flow rate on particle removal and damage performance will be presented. The physical mechanism of atomized spray enables chemical etching of oxides to be minimized without sacrificing particle removal efficiency. Results using this technique in conjunction with chemistry, to further improve particle removal, will be presented. Results over a large range of particle sizes will be shown. Specific applications will be discussed.