New fault location system for power transmission lines usingcomposite fiber-optic overhead ground wire (OPGW)

A fault location (FL) method using composite fiber-optic overhead ground wires (OPGWs) was developed to find out where electrical faults occur on overhead power transmission lines. This method locates the fault section by detecting the current induced in the ground wire, i.e. the OPGW in this system. Since detected fault information is essentially uncertain, the fault information is treated in the proposed FL method as a current distribution pattern throughout the power line, and fuzzy theory is applied to realize the manner of fault location used by electrical power engineers. It was confirmed by computer simulations that the fault section can be accurately located using this method under various conditions. This FL system was applied to several commercial power transmission lines and successfully located the sections where electrical faults occurred     

MgCl2 supported titanium catalyst prepared by mechanical pulverization

Summary MgCl₂ supported titanium catalysts were prepared by mechanical pulverization or MgCl₂ with titanium compounds using two types of machines, rotatory mill and vibratory mill. Both methods gave substantially the same results, although vibratory mill much saved the milling time. The nature of the fixed titanium compounds was not homogeneous, and the titanium compounds fixed at an earlier stage of milling, which could be located at exposed active edge positions of MgCl₂ particles, showed higher activity in ethylene polymerization. On the other hand, those fixed at the later stage showed lower activity and caused reaggregation of the particles. Furthermore, chlorine-free titanate compounds, Ti(OBu)₄ and Ti(OEt)₄, also could be fixed on MgCl₂ which showed high activity in ethylene polymerization.     

Natural history of diabetes mellitus with special reference to age of onset and vascular complications

Age and sex distribution of diabetics, seasonal incidence of diabetes, grade of hyperglycemia, frequency of vascular complications and daily living conditions were studied of 2771 diabetic patients experienced at five clinics. The cases consisted of 1587 male and 1184 female diabetics. The distribution of age of diabetes onset revealed that males predominate among diabetics but females predominate among child diabetics, and that the precentage of child was extremely low. This pattern was emphasized as characteristic of Japanese diabetic population. Distribution of fasting blood sugar at the diagnosis of diabetes was compared among the age groups of diabetes-onset and the results showed that percentage of the value exceeding 300 mg/100 ml was highest in the under 10 year-onset cases and decreased with age. The frequency of diabetic retinopathy and of ischemic ECG changes was analysed from the view point of age of diabetes onset and also the duration of the disease. The frequency of the retinopathy at the diabetes-onset was zero in the under 10 year-onset cases, 4.2% in the 10s-onset cases and increased with age. The longer the duration of the disease the higher the frequency of the retinopathy was. This increase along with the duration was most remarkable in the 10s- and 20s-onset cases and less remarkable in the 30s-onset cases. The retinopathy was significantly more frequent in female diabetics. Daily of the patients were studied by a questionnaire and the analysis of 1022 cases with diabetes of more than three years revealed that cases of patients working uneventfully and/or feeling fit were most frequent among the 30s- or 40s-onset cases and that cases of bed-disability were frequent among the cases whose diabetes was found in their twenties or younger. This study showed that the prognosis of the patients is quite different according to whether their diabetes occurred before of after 30 years of age.     

Effective selection system for experimental evolution of random polypeptides towards DNA-binding protein

An experimental evolution with selection based on binding affinity to DNA was carried out on a library of phage-displayed random polypeptides of about 140 amino acid residues. First, we constructed a system to artificially evolve phage-displayed random polypeptides toward binding to a target DNA containing a restriction enzyme site, in which random polypeptides capable of binding the DNA were recovered as complexes with the target DNA by digestion with the restriction enzyme. The experimental evolution cycle, including the above selection system and random mutagenesis for generating the next mutant library, was repeated until the fourth generation. The ability to bind to the DNA was enhanced per generation. In the fourth generation, convergence of the selected clones to a dominant sequence was observed. These results indicate that the newly constructed selection system is effective for exploring the evolvability of random polypeptides towards DNA-binding proteins.     

Increased expression of nucleoside diphosphate kinases/nm23 in human diploid fibroblasts transformed by SV40 large T antigen or 60Co irradiation

YACHIYODA SZ-5000 is a new model of lithotriptor made in Japan, of which the energy source is microexplosion. Compared with the old type of SZ-1, the water bag is substituted for a hot water bath and ultrasonography as well as fluoroscopy can be used for stone localization. Moreover, this new model is extremely small. The first clinical trial of 32 candidates with urinary tract calculi (34 stones) was performed at our hospital between September 1991 and June 1992. They were 10 women and 22 men between 25 and 71 with a mean of 47.3 years. All patients received no anesthesia. The stone location was: R2 for 16 stones, R3 for 5, U1 for 9, U2 for 1, and U3 for 3. The mean size was 14.1 mm. A mean number of 364, 326 and 324 shock waves were given for the R2, 3, U1, and U2, 3 stones, respectively. The second or third sessions were performed on 7 patients. Obvious symptoms and signs observed during the treatment were; local pain in 9 patients, nausea in 3, hypotension and bradycardia in 6, and hypertension in 3. Posttreatment fever up was found in two patients. In 34 stones, the efficiency evaluated 3 months later was 85.0% as determined by kidney-ureter-bladder X-ray and intravenous pyeography. In conclusion, YACHIYODA SZ-5000 is useful and safe in the management of patients with urinary tract stones.     

Pancreatic diabetes in Japan

Islets of Langerhans surrounded by a semipermeable membrane to prevent an immune response by the host immunosystem is a potential way of treating type I diabetes mellitus. In this study, poly(vinyl alcohol) (PVA) tubular membranes with added polyethylene glycol to create pores in the skin layer were prepared to improve their diffusion property. In a static incubation study, islets cultured in the PVA tubular membranes still demonstrated their function of secreting insulin after 30 days. When the tubular PVA bioartificial pancreas was perifused in a small chamber with RPMI-1640 medium containing glucose at concentrations of 5.6-16.6 mmol/L, insulin release began to increase without delay. Therefore, such a membrane is an alternative potential material for a bioartificial pancreas. In addition, a mathematical mass transfer model of insulin release was developed and compared with the perifusion data. It was shown that satisfactory kinetics could be achieved with a PVA membrane. However, the model showed that the insulin output of islets cultured in the PVA tubular membrane must be increased to improve the performance significantly. These findings suggest that a bioartificial pancreas using a PVA membrane is a promising material, but the technique for seeding islets in the chamber requires further modification.     

Endocytosis in rat intrahepatic bile duct epithelial cells of horseradish peroxidase injected into the common bile duct or the portal vein

This article reviews the role of the peroxisome in cellular signalling, with particular emphasis on the unique contributions of this organelle to the complex regulatory inter-relationships of cellular processes within the mammalian organism. Among the topics covered are the close alignments between the signalling systems governing peroxisome proliferation and those of the steroid hormone/thyroid hormone/vitamin D nuclear-receptor superfamily; the regulation of the permeability of the peroxisomal membrane; the involvements of lysophosphatidic acid as an intra- and inter-cellular messenger; the special role of the phosphatidylcholine cycle and its derivative messengers in relation to peroxisomal metabolism; peroxisomal contributions to the regulation of oxygen free radical levels in tissues and the significance of these radicals as second messengers; the evidence of peroxisomal influences on inter-cellular signalling from metabolic turnover studies; modifications of the regulatory significance of fatty acids by the peroxisome; the commonalities in metabolic relationships between the peroxisome and other cellular organelles; and regulatory shuttles associated with peroxisomal function. It is concluded that the peroxisome displays several significant interconnections with the cellular-signalling apparatus, that it is capable of imprinting a characteristic influence on the regulatory network in the cell, and that the contributions of this organelle deserve greater consideration in future investigations of cell-signalling phenomena.     

Magnetic property of the low temperature phase of α-(BEDT-TTF)2KHg(SCN)4

The low temperature phase of the organic conductor, α-(BEDT-TTF)₂KHg(SCN)₄, has been investigated by EPR measurements. The spin susceptibility determined by the EPR intensity is 3 × 10⁻⁴ emu/mol at room temperature, in agreement with the static susceptibility measurement. It decreases slightly with decreasing temperature down to 10 K, below which a rapid drop of the intensity is observed for all directions of the applied field. This temperature is close to the one which the resistivity anomaly was observed at. At temperatures below 20 K, the EPR signal was found to split into two or three lines depending on the external field direction. We discuss the possible origin of the splitting.     

Trypsin-catalyzed peptide synthesis and various p-guanidinophenyl esters as acyl donors

Trypsin-catalyzed peptide synthesis has been studied by using p-guanidinophenyl esters of N alpha-(tert-butyloxycarbonyl)amino acid and peptide as acyl donor components. The reaction conditions were optimized for organic solvents, pH, and concentration of acceptor. The method was especially useful for the preparation of various peptides containing D-amino acids. The enzymatic hydrolysis of the resulting products was negligible.     

Vapor deposition polymerization of 1,9-bis(trimethylsilyloxy)[2.2]paracyclophane

Summary Vapor deposition polymerization of 1,9-bis(trimethylsilyloxy)[2.2]paracyclophane (Me ₃ SiO-PC) was carried out to obtain poly(7-trimethylsilyloxy-p-xylylene) (Me ₃ SiO-PPX) as a colorless tough film. The Me ₃ SiO-PPX film was successfully converted to poly(7-hydroxy-p-xylylene) (HO-PPX) film by the hydrolysis reaction in THF in the presence of hydrochloric acid.