Development of Multi-extreme ESR Measurement System in Kobe

Development of multi-extreme electron spin resonance (ESR) measurement system is in progress in Kobe. We have installed the pulsed magnetic field up to 55 T and our high field ESR system can cover the frequency region from 30 GHz to 7 THz. Our aim is to extend our high field ESR system to the multi-extreme ESR measurement system by combining low temperature, high pressure and nano techniques, and the combination with the high pressure is focused in the paper. High pressure can be achieved up to 1.4 GPa by using the transmission type piston cylinder pressure cell. We have succeeded in combining the high field and the high pressure. As an example, the pressure dependence of the spin gap in SrCu₂(BO₃)₂, S=1/2 Shustally-Sutherland dimer system, observed by our multi-extreme ESR measurement is presented. This measurement is the direct and precise measurement of the spin gap, and the spin gap decreased from 723 GHz (34.7 K) to 581 GHz (27.9 K) at 1.2 GPa.     

Complete Assignment of 1H and 13C NMR Spectra of Benz[a]Anthracene-7,12-dione and its Nitro Derivative

Benz[a]anthracene-7, 12-dione (1) was nitrated directly by nitric acid and a nitro-derivative (2) was obtained. Molecular orbital calculation predicted that the nitration reaction occurs in the C1 or C4 position of (1). To determine the position of the nitro group of (2), NMR chemical shifts were used. The absence of the chemical shift at δ9.7 in (2) clearly indicated that the nitro substituent issituated at the C1 position. The methodologies of FG-HOHAHA, FG-NOESY, FG-CH-COSY, and FG-HMBC were also used for detailed NMR spectral determination for their polycyclic aromatic ketons.     

Ultrastructure of immotile spermatozoa obtained from infertile male patients

We sometimes experienced infertile patients whose sperms had no motility but were not stained by Eosin Y. In this paper we report five cases of so-called "immotile spermatozoa". The ultrastructure of sperm tails was examined by transmission electrone microscope (TEM). These cases were selected from the out-patient population who attended infertility clinic of our department. The semen analyses showed that all the cases had sperm motility below 1% and more than 90% of the spermatozoa were proven alive. Family history revealed that one case had an infertile sibling. None of them had situs inversus, bronchiectasis and chronic sinusitis which are classic trias of Kartagener's syndrome. They had no symptoms of upper respiratory tract infection which was caused by the abnormality in the flagella of the respiratory tract. The TEM pictures of sperm tails showed partial deletion of inner dynein arms in two cases, lack of central microtubular doublets (so-called 9 + 0) in two cases and disarrangement of microtubular doublets in one case. For the treatment of these cases there is no effective means but AID. However, the rapid progress of IVF-ET techniques and a report that the spermatozoa from Kartagener's syndrome had showed penetration into eggs encouraged us to think the micromanipulation of spermatozoa with IVF-ET as a hopeful option of the treatment in the near future.     

Handwritten digit recognition: investigation of normalization and feature extraction techniques

The performance evaluation of various techniques is important to select the correct options in developing character recognition systems. In our previous works, we have proposed aspect ratio adaptive normalization (ARAN) and have evaluated the performance of state-of-the-art feature extraction and classification techniques. For this time, we will propose some improved normalization functions and direction feature extraction strategies and will compare their performance with existing techniques. We compare ten normalization functions (seven based on dimensions and three based on moments) and eight feature vectors on three distinct data sources. The normalization functions and feature vectors are combined to produce eighty classification accuracies to each dataset. The comparison of normalization functions shows that moment-based functions outperform the dimension-based ones and the aspect ratio mapping is influential. The comparison of feature vectors shows that the improved feature extraction strategies outperform their baseline counterparts. The gradient feature from gray-scale image mostly yields the best performance and the improved NCFE (normalization-cooperated feature extraction) features also perform well. The combined effects of normalization, feature extraction, and classification have yielded very high accuracies on well-known datasets.     

Unsteady behavior and control of vortices in centrifugal compressor

Two examples of the use of vortex control to reduce noise and enhance the stable operating range of a centrifugal compressor are presented in this paper.In the case of high-flow operation of a centrifugal compressor with a vaned diffuser,a discrete frequency noise induced by interaction between the impeller-discharge flow and the diffuser vane,which appears most notably in the power spectra of the radiated noise,can be reduced using a tapered diffuser vane（TDV） without affecting the performance of the compressor.Twin longitudinal vortices produced by leakage flow passing through the tapered portion of the diffuser vane induce secondary flow in the direction of the blade surface and prevent flow separation from the leading edge of the diffuser.The use of a TDV can effectively reduce both the discrete frequency noise generated by the interaction between the impeller-discharge flow and the diffuser surface and the broadband turbulent noise component.In the case of low-flow operation,a leading-edge vortex（LEV） that forms on the shroud side of the suction surface near the leading edge of the diffuser increases significantly in size and blocks flow in the diffuser passage.The formation of an LEV may adversely affect the performance of the compressor and may cause the diffuser to stall.Using a one-side tapered diffuser vane to suppress the evolution of an LEV,the stable operating range of the compressor can be increased by more than 12 percent,and the pressure-rise characteristics of the compressor can be improved.The results of a supplementary examination of the structure and unsteady behavior of LEVs,conducted by means of detailed numerical simulations,are also presented.     

Radical-scavenging Activity of Estrogen and Estrogen-like Compounds Using the Induction Period Method

The radical-scavenging activity of estrogens (estrone, 2-hydroxyestradiol), estrogen-like compounds (diethylstilbestrol, DES; bisphenol A, BPA) and the monophenolic compound 2,6-di-t-butyl-4-methoxyphenol (BMP) was investigated using the method of measuring the induction period for polymerization of methyl methacrylate (MMA) initiated by thermal decomposition of 2,2′-azobisisobutyronitrile (AIBN) and benzoyl peroxide (BPO) at 70°C using differential scanning calorimetry (DSC). The stoichiometric factor (n, number of free radicals trapped by one mole of antioxidant moiety) for the AIBN system declined in the order BMP (2.0), 2-hydroxyestradiol (2.0)> DES (1.3) > BPA (1.2) > estrone (0.9), whereas that for the BPO system declined in the order BMP (2.0) >DES (1.9), BPA (1.9) > estrone (1.3) > 2-hydroxyestradiol (0.7). The inhibition rate constant (k_inh × 10⁻³ M⁻¹s⁻¹) for the AIBN system declined in the order estrone (2.2) > BPA (2.0) > DES (1.9) > 2-hydroxyestradiol (1.2) > BMP (1.1), whereas that for the BPO system declined in the order 2-hydroxyestradiol (3.2) > estrone (1.4) > DES (1.2) > BPA (1.0) > BMP (0.9). The radical-scavenging activity for bioactive compounds such as estrogens should be evaluated using these two methods (the n and k_inh) to elucidate the mechanism of a particular reaction. The great difference of the n and k_inh for estrogens between the AIBN and BPO system suggested that their oxidation process is complex.     

Thermoelectric properties of porous SiC/C composites

We developed a porous SiC/C composite by oxidizing a SiC/C composite made from a mixed powder of wood charcoal and SiO₂ (32–45 μm) by pulse current sintering at 1600 and 1800 °C under a N₂ atmosphere. The microstructures of the porous SiC/C composites with oxidation and the SiC/C composites without oxidation were analyzed by Raman spectroscopy and scanning electron microscopy (SEM). Raman spectra revealed the disappearance of excess carbon and the presence of β-SiC. The porous microstructure was monitored by SEM observation as a function of the heat treatment temperature. The thermoelectric properties of porous SiC/C composites with oxidation and SiC/C composites without oxidation were investigated by measuring the Seebeck coefficient, the electrical conductivity and thermal conductivity. The Seebeck coefficient of all samples revealed n-type conduction, and the absolute value of the Seebeck coefficient for the porous SiC/C samples with oxidation was much larger than that for the SiC/C samples without oxidation. For the electrical conductivity the reverse is true. Only the thermal conductivity of the SiC/C sample heated to 1800 °C without oxidation was high initially and stayed rather high. In general, the thermoelectric properties improved at higher measurement temperatures indicating their suitability for high-temperature thermoelectric conversion. A maximum figure of merit of 2.01×10⁻⁵ K⁻¹ was obtained at 700 °C in porous SiC/C samples sintered at 1800 °C with oxidation.     

The effectiveness of interferon therapy on occurrence of hepatocellular carcinoma in chronic hepatitis C

To clarify the effect of interferon (IFN) therapy for chronic hepatitis C (CHC) on the occurrence of hepatocellular carcinoma (HCC), 149 patients who were observed over a period of five years (mean: 7.6 years) were studied. The C-1 group, 33 patients with complete response to IFN; the C-2 group, 55 patients with no response to IFN; and the C-3 group, 61 patients who did not receive IFN. The occurrence rate of HCC was 0.9%/year/person. In the C-1, C-2 and C-3 groups, the rates were 0%, 0.3%, and 1.6%, respectively. The rate in C-1 + C-2 groups was significantly lower than that of the C-3 group (P<0.05). These data suggest IFN may suppress the occurrence of HCC in CHC.