Novel wide band gap alloyed semiconductors, <Emphasis Type="Italic">x</Emphasis>(LiGaO<Subscript>2</Subscript>)<Subscript>1/2</Subscript>-(1−<Emphasis Type="Italic">x</Emphasis>)ZnO,and fabrication of their thin films

Oxide semiconductor alloys of x(LiGaO₂)_1/2-(1−x)ZnO were fabricated by the solid state reaction between β-LiGaO₂ and ZnO and rf-magnetron sputtering. For the solid state reaction, the wurtzite-type single phases were obtained in the composition range of x⩽0.38. The formation range of the alloys was wider than that of the (Mg_1−x Zn _x )O system, because the β-LiGaO₂ possesses a wurtzite-derived structure and approximately the same lattice constants with ZnO. The electrical resistivity and energy band gap of the 0.38(LiGaO₂)_1/2-0.62ZnO alloyed ceramic were 0.45 Ωcm and 3.7 eV, respectively, at room temperature. For the alloying by sputtering, the films consisting of the wurtzite-type single phase were obtained over the entire composition range of x(LiGaO₂)_1/2-(1−x)ZnO. The energy band gap was controllable in the range from 3.3 to 5.6 eV. For the as-deposited film fabricated using the 0.4(LiGaO₂)_1/2-0.6ZnO alloyed ceramic target, the energy band gap was 3.74 eV, and the electrical resistivity, carrier density and the Hall mobility at room temperature were 3.6 Ωcm, 3.4×10¹⁷ cm⁻³ and 5.6 cm² V⁻¹ s⁻¹, respectively.     

Aspects of voltage responses of induction motor loads

In this paper, the voltage dynamics of induction motor loads up to some ten seconds are discussed in terms of a linearized model. It is generally recognized that the dynamics of a power system load mainly originate from the induction motor dynamics constituting the load. Aspects of the voltage dynamics of induction motors are analyzed with respect to machine constants. The results show that small and medium-sized induction motors have dynamics that can be well approximated at the first order, thus partly accounting for the fact that most feeders indicate first-order dynamics     

Reduced C-terminal Src kinase (Csk) activities in hepatocellular carcinoma

The proto-oncogene product pp60(c-src) is the cellular homologue of the Rous sarcoma transforming gene, and it is a non-receptor-linked and membrane-associated tyrosine kinase. There is a close correlation between elevated pp60(c-src) activity and cell transformation. We have recently reported that pp60(c-src) was activated in hepatocellular carcinoma (HCC) of human and Long-Evans cinnamon (LEC) rats. However, the mechanisms involved in this process remain unknown. C-terminal Src kinase (Csk) is a novel cytoplasmic protein tyrosine kinase that inactivates the members of the Src family protein tyrosine kinase in vitro. We investigated the role of Csk in hepatocarcinogenesis by analyzing the location, amount of Csk, and its kinase activity levels in nontumorous cirrhotic and tumorous sections of HCC of patients and an animal model of LEC rats. Csk tyrosine kinase activity was significantly reduced in tumorous tissues compared with nontumorous sections of patients as well as LEC rats. A single immunoreactive band at 50 kd was detected with Csk antibody in normal liver (NL), chronic hepatitis (CH), and nontumorous cirrhotic (NTC) segments of HCC of patients and LEC rats. In human tumorous tissues, Western blot revealed a 53-kd immunoreactive band, which was slightly larger than the usual 50-kd band of Csk. These results suggest that the reduced activity of tyrosine kinase of Csk may play an important role in the malignant transformation of hepatocytes in human and LEC rat, and the appearance of 53-kd Csk-related protein may be closely involved in the progression of cirrhosis to HCC in humans, and that 50-kd Csk may act as an antioncogene through the negative regulation of pp60(c-src) in the development of human HCC.     

Fine needle aspiration cytology of lipid-secreting carcinoma of the breast. A case report

A renotropic factor was partially purified by sequential gel filtration and anion exchanger chromatography from plasma of human kidney transplantation donors and a renal cancer patient after uninephrectomy. This activity increased the rate of [3H]thymidine incorporation into DNA in rat cortical tubules, but not in rat liver cells, within the range of 100-200 ng/ml protein. The renotropic activity was detected between 7 and 12 days after uninephrectomy, and at least in 1 case decreased thereafter. This activity was undetected in gel-filtrated plasma of patients after a nonurological surgical procedure. The potency of this renotropic activity and its elution by gel filtration are similar to those displayed by a renal growth factor activity isolated from uninephrectomized rat plasma, as recently reported.     

Microprocessor-Based Stabilizing Control Equipment for Survival of Isolated Mid-City Power System

This paper describes the recently developed microprocessor-based stabilizing control equipment for survival of isolated mid-city power system having heavy load and large shunt capacitance (Underground cables) of TOKYO ELECTRIC POWER COMPANY (TEPCO). The active power balance and voltage stabilizing control scheme is realized by high-speed control of the 66KV load feeders, shunt reactors, shunt capacitors and 275KV & 154KV underground transmission cables dispersed in the power system.     

Impaired myocardial vasodilation during hyperemic stress with dipyridamole in hypertriglyceridemia

OBJECTIVES: This study sought to investigate the specific role of hypertriglyceridemia in the myocardial hyperemic stress with dipyridamole/rest flow ratio (MDR). BACKGROUND: Reduced MDR has been reported in hypercholesterolemic patients without evidence of ischemia. However, the specific role of hypertriglyceridemia in MDR has not been studied. METHODS: Fifteen nondiabetic normocholesterolemic hypertriglyceridemic patients and 13 age-matched control subjects were studied. Myocardial blood flow (MBF) during dipyridamole administration and baseline MBF in hypertriglyceridemic patients and control subjects were measured using positron emission tomography and nitrogen-13 ammonia, after which the MDR was calculated. RESULTS: Baseline MBF (ml/min per 100 g heart weight) in hypertriglyceridemic patients (mean +/- SD 73.6 +/- 24.1) did not differ significantly from that in control subjects (81.6 +/- 37.2). MBF during dipyridamole loading in hypertriglyceridemic patients (198 +/- 106) was significantly reduced compared with that in control subjects (313 +/- 176, p < 0.05), as was the MDR (2.71 +/- 1.07 vs. 3.73 +/- 1.14, respectively, p < 0.05). Spearman rank-order correlation analysis showed a significant relation between plasma triglyceride concentration and MDR (r = -0.466, asymptotic SE 0.157, p = 0.0125); however, no such significant relation was seen between total plasma cholesterol concentration and MDR (r = -0.369, asymptotic SE 0.130, p = 0.059). CONCLUSIONS: Impaired myocardial vasodilation was suggested in hypertriglyceridemic patients without symptoms and signs of ischemia.     

Influence of cellular incorporation of n-3 eicosapentaenoic acid on intracellular Ca2+ concentration and membrane potential in vascular smooth muscle cells

Recombinant antibody fragments expressed in the cytoplasm of cells have considerable practical potential. However in the reducing environment of the cytoplasm, the intradomain disulphide bonds are not formed and the fragments are unstable and expressed in low yields. Here we attempted to overcome these limitations. We first isolated an antibody single chain Fv fragment that binds and activates an inactive mutant beta-galactosidase. We then subjected the gene encoding the scFv fragment to random mutation in vitro by error-prone polymerase chain reaction, and co-expressed the mutant beta-galactosidase and mutant antibody fragments in lac- bacteria. By plating on limiting lactose, we selected for antibody mutants with improved expression, and after four successive rounds of mutation and selection, isolated an antibody fragment that is expressed in the bacterial cytoplasm with yields of 0.5 g/l in a shaker flask (A600 nm of 5.5) and 3.1 g/l (A600 nm=33) in a fermentor. Analysis of the mutant antibody fragments revealed that the disulphide bonds are reduced in the cytoplasm, and that the fragments could be denatured and renatured efficiently under reducing conditions in vitro. This shows that with a suitable method of screening or selection, it is possible to make folded and functional antibody fragments in excellent yield in the cytoplasm.     

Characterization of mutant myosins of Dictyostelium discoideum equivalent to human familial hypertrophic cardiomyopathy mutants. Molecular force level of mutant myosins may have a prognostic implication

Recent studies have revealed that familial hypertrophic cardiomyopathy (FHC) is caused by missence mutations in myosin heavy chain or other sarcomeric proteins. To investigate the functional impact of FHC mutations in myosin heavy chain, mutants of Dictyostelium discoideum myosin II equivalent to human FHC mutations were generated by site-directed mutagenesis, and their motor function was characterized at the molecular level. These mutants, i.e., R397Q, F506C, G575R, A699R, K703Q, and K703W are respectively equivalent to R403Q, F513C, G584R, G716R, R719Q, and R719W FHC mutants. We measured the force generated by these myosin mutants as well as the sliding velocity and the actin-activated ATPase activity. These measurements showed that the A699R, K703Q, and K703W myosins exhibited unexpectedly weak affinity with actin and the lowest level of force, though their ATPase activity remained rather high. F506C mutant which has been reported to have benign prognosis exhibited the least impairment of the motile and enzymatic activities. The motor functions of R397Q and G575R myosins were classified as intermediate. These results suggest that the force level of mutant myosin molecule may be one of the key factors for pathogenesis which affect the prognosis of human FHC.