HighT c of liquid-quenched Bi1.6Pb0.4Sr2Ga2Cu3Ox

AlthoughT _c cannot be found for a liquid-quenched Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_x glassy sample, a highT _c is found after annealing for 24 h at 1100 K. The maximum offset temperature of the superconducting transition is 113.3 K at 2.2 × 10^–2mAmm^–2. The maximumT _{c off} is larger than that (the maximumT _{c off} is 103.4 K at 2.0 × 10^–2 mAmm^–2) of sintered specimens before liquid quenching.     

Photovoltaic display module in a mobile GPS

We have developed a mobile global positioning system (GPS) that operates on just photovoltaic (PV) cells. The system receives wireless signals from satellites and shows one's present location accurately on a map without the need for a battery. A PV display module, which combines a transparent LCD with a-Si PV cells and has a power generation function, is added to ordinary PV cells to increase the total amount of power generated. The PV display module enables 40% more power generation than a system without the module.     

Molecular screening of both the promoter and the protein coding regions in the human ob gene in Japanese obese subjects with non-insulin-dependent diabetes mellitus

OBJECTIVE: Although the molecular mechanism of obesity has been poorly understood, recent studies indicate that leptin plays a critical role in regulating both food intake and body weight. Because obesity decreases the sensitivity to insulin, the human ob gene is presumed to be one of the candidate genes for non-insulin-dependent diabetes mellitus (NIDDM) associated with obesity. Although the protein coding region in the ob gene has been screened for mutations, the promoter region and the non-coding first exon have not yet been studied. We investigated the involvement of the human ob gene, especially mutations at the promoter region and the non-coding first exon, in the development of NIDDM associated with obesity. SUBJECTS: The study group comprised 60 Japanese obese subjects with NIDDM (body mass index (BMI) 43.6 > or = BMI > or = 26.4, 29.0+/-0.41 (mean+/-S.E.M.)) and 24 obese individuals with impaired glucose tolerance (IGT) (30 > or = BMI > or = 26.4, 27.1+/-0.22). METHODS: Mutations at both the promoter region and all three exons in the human ob gene were screened by the single-stranded conformational polymorphism analysis. When aberrantly migrated bands were recognized, the PCR-amplified DNA fragment was directly sequenced. RESULTS: In the protein coding region a silent mutation in the second exon was detected. The non-coding first exon and the about 100 bp 5'-flanking region of the gene which contains a proximal CCAAT/enhancer-binding protein site were screened, but no mutations were found. CONCLUSION: These results suggest that no mutations in either the promoter region at the about 100 bp 5'-flanking region of the gene, or in any of the three exons, are involved in the development of NIDDM or IGT associated with obesity.     

Low chirp operation in 1.6 μm quantum dot laser under 2.5 GHzdirect modulation

A long wavelength InAs quantum dot laser on an InP substrate was operated under continuous wave current at room temperature and had a threshold current of 20 mA. Modulation bandwidth was 4 GHz and the low chirp of around 0.01 nm in lasing wavelength was achieved during 2.5 GHz current modulation     

Synthesis and properties of carbocyclic oligothymidylate lacking the 5'-methylene

Oligodeoxynucleotides possessing a shortened internucleotidic linkage have been prepared using carbocyclic nucleosides lacking the 5'-methylene as the monomeric units. Specifically, the oligomers derived from carbocyclic 5'-n or thymidine and 2'-hydroxy-3'-deoxythymidine will be described.     

Mutations of the transforming growth factor-beta type II receptor gene are strongly related to sporadic proximal colon carcinomas with microsatellite instability

BACKGROUND: Mutations of the transforming growth factor-beta type II receptor gene (TGF-beta RII) have been found in several replication error-positive sporadic colorectal carcinomas and hereditary nonpolyposis colorectal carcinoma cell lines. The aim of this study was to clarify the role of TGF-beta RII in sporadic colorectal carcinogenesis. METHODS: The authors screened for mutations at simple repeated sequences in the TGF-beta RII gene by polymerase chain reaction-single strand conformation polymorphism. They also examined genomic instability, using five microsatellite DNA markers in 69 sporadic colorectal carcinomas. When the carcinomas exhibited the TGF-beta RII mutations, the authors screened further for mutations in two DNA mismatch repair genes, hMSH2 and hMLH1. RESULTS: Seven of the 69 cancers (10%) showed one or two A deletions in TGF-beta RII and resultant frameshift mutations in nucleotide positions 709-718 containing a (A) 10 repeated sequence; but none of these appeared in the corresponding normal DNA, indicating a somatic mutation. All of the seven cancers were located in the proximal colon; there were none in the distal colon (P < 0.01). On the other hand, 22 of the 69 carcinomas (32%) showed the replication error-positive phenotype. The frequency of replication errors in proximal colon carcinomas was higher than that in distal colon carcinomas (P < 0.05). All 7 cancers with TGF-beta RII mutations showed replication errors. One of them revealed a nonsense mutation at codon 413, and 1 revealed a loss of heterozygosity in hMSH2. CONCLUSIONS: These data indicate that mutations of TGF-beta RII are strongly related to proximal colon carcinomas with microsatellite instability and that the mechanism of carcinogenesis in some proximal colon carcinomas is similar to that in hereditary nonpolyposis colorectal carcinoma.     

Turbulence generated by a wind tunnel of multi-fan type in uniformly active and quasi-grid modes

In an attempt to simulate atmospheric turbulence at high-Reynolds numbers, an innovative wind tunnel of “multi-fan type” is developed. The airflow is driven by an array of fans (9 columns × 11 rows), each of which is independently controlled by a computer. A driving mode (“uniformly active mode”) is applied, which has been typically used for turbulence modeling using a smaller wind tunnel. Another mode with grid-like distributed fans that are driven steadily (“quasi-grid mode”) is introduced and found to produce turbulence characteristics similar to the conventional grid turbulence. Comparison of turbulence characteristics of the two modes reveals the turbulence structure of the uniformly active mode.     

Pulmonary arterial impedance analysis by the use of the oscillated assist flow

Pulmonary arterial impedance is an important and interesting characteristic that can be used to evaluate the physiological properties of the pulmonary vessel. However, power spectrum analysis of the pulmonary artery pressure and flow pattern have suggested that peak power in the relatively high frequency range (> 10 Hz) is significantly low; thus, we cannot analyze the vessel properties in the high frequency range. In this study, we used the newly developed vibrating flow pump (VFP), which can generate oscillated blood flow with a relatively high frequency (10-50 Hz) for right heart bypass, to evaluate the pulmonary arterial impedance pattern in the high frequency range. Acute animal experiments of the right heart bypass from the right atrium to the pulmonary artery using 6 healthy adult goats were performed. The flow pattern and pressure of the pulmonary artery, electrocardiograms (ECGs), and arterial and right atrial pressures were continuously monitored during the experiments. Spectral analysis of the hemodynamic parameters using the fast Fourier transform (FFT) method was performed to evaluate the spectral properties. The coherence function, transfer function, and phase patterns were calculated to analyze the impedance pattern in the relatively high frequency area. Previously, various investigators had tried to analyze the impedance patterns of the pulmonary artery; however, they could not analyze the impedance patterns over 10 Hz because the spectral patterns of the pulmonary flow do not have high power at high frequencies. These physiological analyses may be useful in designing the optimal pulmonary circulation.