Fabrication of transparent hydroxyapatite and application to bone marrow derived cell/hydroxyapatite interaction observation in-vivo

Transparent hydroxyapatite (HA), 99.6% relative density, was prepared by hot isostatic pressing. Optical transmittance of 1 mm thick HA was greater than 60% at 700 nm. Twenty transparent HA plates (10×7×1 mm) were implanted into the medullary cavities of two dogs' femora. At 1 and 2 weeks after implantation the bone marrow derived cells that adhered to the HA surfaces were histochemically examined by light microscopy and scanning electron microscopy. Four types of enzymatic reactions were employed to identify cell types. Alkaline phosphatase was used as a marker for osteoblasts, acid phosphatase and tartrate-resistant acid phosphatase as a marker for osteoclasts and non-specific esterase as a marker for macrophages. Cells adhered to the HA surfaces were a mixed population of osteoblasts, osteoclasts and macrophages. By 2 weeks, the number of osteoblasts increased and formed a bone-like matrix. A small number of osteoclasts formed resorption lacunae on the HA after 2 weeks. By utilizing the transparency of the HA, whole-view of bone matrix formation by osteoblasts and simultaneous resorption of HA by osteoclasts was observed simply and dynamically by light microscopy.     

A study of the buying price of photovoltaic electricity under a carbon tax regime

Assuming that photovoltaic (PV) systems are adopted in residential houses under a carbon tax regime, the economic performance of PV systems is investigated from the standpoint of an electric utility. The economic performance is estimated by using the buying price of PV electricity and the PV economic index, which is defined as the ratio of the buying price to the generation cost of the electric utility. Because these values depend on electric power development and operation, the best mix and the operation of power plants are obtained by linear programming subject to restrictions on power generation. Then, the buying price of PV electricity is calculated from the total cost of the electric utility. The buying price means the upper limit at which the electric utility never suffers a loss. The buying price is also compared with the power generation cost. The parameters are the prevalence attainment ratio of PV systems (0 to 100%), the upper limit of newly developed nuclear power plants (0 to 4 GW/10 y), and the generated energy ratio of coal‐fired thermal plants (0 to 15%). Chubu Electric Power Company, Inc. is used as the electric utility. The calculation results show that the buying price of PV electricity increases linearly with increasing carbon tax rate, and its values are 9 and 11.5 yen/kWh when the carbon tax rate is 0 and 25 thousand yen/t‐C, respectively, which does not depend on the prevalence attainment ratio of PV systems and the upper limit of newly developed nuclear power plants. It is not the carbon tax rate but the newly developed nuclear power plant that influences the PV economic index. The values of the PV economic index are 1.35 to 1.45 and 1.50 to 1.60 when the newly developed nuclear power plant capacity is 0 and 4 GW/10 y, respectively. These results show that the economic performance of PV systems is increased by developing nuclear power plants at a certain rate and introducing a carbon tax. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(2): 38–49, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10067     

Alignment control of columnar liquid crystals with wavelength tunable CO2 laser irradiation

Infrared-induced alignment change with wavelength tunable CO₂ laser irradiation for columnar liquid crystal domains was investigated for a liquid crystalline triphenylene derivative. A uniformly aligned alignment change of domains was observed when a chopped linearly polarized infrared laser light corresponding to the wavelength of the aromatic C-O-C stretching vibration band (9.65 μm) was irradiated. The results strongly imply that the infrared irradiation is a possible technique for device fabrication by use of columnar mesophase as a liquid crystalline semiconductor.     

Biomedical Application of Low Molecular Weight Heparin/Protamine Nano/Micro Particles as Cell- and Growth Factor-Carriers and Coating Matrix

Low molecular weight heparin (LMWH)/protamine (P) nano/micro particles (N/MPs) (LMWH/P N/MPs) were applied as carriers for heparin-binding growth factors (GFs) and for adhesive cells including adipose-derived stromal cells (ADSCs) and bone marrow-derived mesenchymal stem cells (BMSCs). A mixture of LMWH and P yields a dispersion of N/MPs (100 nm–3 μm in diameter). LMWH/P N/MPs can be immobilized onto cell surfaces or extracellular matrix, control the release, activate GFs and protect various GFs. Furthermore, LMWH/P N/MPs can also bind to adhesive cell surfaces, inducing cells and LMWH/P N/MPs-aggregate formation. Those aggregates substantially promoted cellular viability, and induced vascularization and fibrous tissue formation in vivo. The LMWH/P N/MPs, in combination with ADSCs or BMSCs, are effective cell-carriers and are potential promising novel therapeutic agents for inducing vascularization and fibrous tissue formation in ischemic disease by transplantation of the ADSCs and LMWH/P N/MPs-aggregates. LMWH/P N/MPs can also bind to tissue culture plates and adsorb exogenous GFs or GFs from those cells. The LMWH/P N/MPs-coated matrix in the presence of GFs may provide novel biomaterials that can control cellular activity such as growth and differentiation. Furthermore, three-dimensional (3D) cultures of cells including ADSCs and BMSCs using plasma-medium gel with LMWH/P N/MPs exhibited efficient cell proliferation. Thus, LMWH/P N/MPs are an adequate carrier both for GFs and for stromal cells such as ADSCs and BMSCs, and are a functional coating matrix for their cultures.     

Simplified 6.3 Mbit/s Codec for Video Conferencing

A color TV codec with a 6.3 Mbit/s transmission bit-rate has been simplified by a newly developed coding method. This method is the combination of a 4-to-1 dot interlace system and 4 bit/pel DPCM. A digital filtering technique for reducing coding distortion is also employed. In comparison with an interframe codec having the same transmission bit-rate, the amount of codec circuitry is halved. Subjective tests were performed to investigate the coded picture quality. It was found that this codec can present acceptable pictures for video conferencing, and that the picture quality for rapidly moving subjects is the same as that of the interframe codec operating at the same bit-rate. A video conferencing system via a digital satellite link has been constructed for experiments by employing this codec. The experiments showed that the satellite link has a sufficiently low transmission error rate for the coded pieture transmission. Moreover, it has been proved that transmission delay does not pose any problems for normal conferences.     

Pseudomorphic n-InGaP/InGaAs/GaAs high electron mobilitytransistors for low-noise amplifiers

The authors developed 0.15-μm-gate pseudomorphic n-InGaP/InGaAs/GaAs HEMTs for low-noise amplifiers. Passivated devices exhibited a noise figure of 0.41 dB with an associated gain of 13.0 dB at 12 GHz including package loss, and of 1.2 dB with an associated gain of 5.8 dB at 50 GHz. Reducing the short-channel effects was the key to achieving the best performance ever reported for passivated and packaged low-noise HEMTs on GaAs substrates. A high aspect ratio under the thin n-InGaP layer and good carrier confinement in the pseudomorphic InGaAs channel reduce the undesirable short-channel effects in these devices     

A 43-Gb/s full-rate-clock 4:1 multiplexer in InP-based HEMT technology

This paper describes a full-rate-clock 4:1 multiplexer (MUX) in a 0.13-/spl mu/m InP-based HEMT technology for 40-Gb/s and above optical fiber link systems. To reduce output jitter, the serialized data are retimed at the final stage by a retimer, a D-type flip-flop, which has a symmetric layout with an optimized spacing to the ground that minimizes coupling capacitances. A phase adjuster, composed of an exclusive OR and a delay switch, uses external control signals to change each phase of the serialized data and clock entering the retimer and gives a correct timing for the clock to drive the retimer. A clock distributor with a simple wired splitter divides the clock into two clocks with high gain and low current. The MUX integrates 1355 HEMTs formed using electron beam lithography. A chip mounted in a test module operated at up to 47 Gb/s with a power consumption of 7.9 W for a single supply voltage of -5.2 V.     

Presaccadic omnidirectional burst activity in the basal interstitial nucleus in the monkey cerebellum

The endocrine function and pituitary imaging in Sheehan's syndrome more than 30 years after causative events were evaluated. Magnetic resonance imaging (MRI), a combined anterior pituitary test, plasma vasopressin-to-osmolality adaptation study, and antithyroid and antipituitary cell antibody measurement were performed in 6 women with Sheehan's syndrome. The interval from delivery to the onset of symptoms of hormonal deficiency ranged from 3 to 32 years. Since clinical onset, all had received glucocorticoid and thyroid replacement therapy. Cranial MRI examination showed an "empty sella" in 5 cases. Among these, 2 of 5 (40%) demonstrated panhypopituitarism and the other 3 (60%) maintained gonadotropin response. The pituitary gland was normally discernible but with a low-intensity lesion on T1-weighted images in a patient who maintained PRL and gonadotropin responses. Posterior pituitary function was abnormal in 3 of 6 (50%) despite the absence of polyuria. No antipituitary antibodies were detected in any of the cases. Thyroid peroxidase antibody was negative in all cases, but antithyroglobulin antibody was detected in 2 of 6 (33%). Thyroid-stimulating antibody was not detected, but one case had an anti-TSH antibody. Thirty years after the initial events, most patients with Sheehan's syndrome showed signs of an empty sella on MRI, all having noticeable suppression of anterior and/or posterior pituitary hormones with no related autoimmunity.     

Atractylodin Produces Antinociceptive Effect through a Long-Lasting TRPA1 Channel Activation

Atractylodin (ATR) is a bioactive component found in dried rhizomes of Atractylodes lancea (AL) De Candolle. Although AL has accumulated empirical evidence for the treatment of pain, the molecular mechanism underlying the anti-pain effect of ATR remains unclear. In this study, we found that ATR increases transient receptor potential ankyrin-1 (TRPA1) single-channel activity in hTRPA1 expressing HEK293 cells. A bath application of ATR produced a long-lasting calcium response, and the response was completely diminished in the dorsal root ganglion neurons of TRPA1 knockout mice. Intraplantar injection of ATR evoked moderate and prolonged nociceptive behavior compared to the injection of allyl isothiocyanate (AITC). Systemic application of ATR inhibited AITC-induced nociceptive responses in a dose-dependent manner. Co-application of ATR and QX-314 increased the noxious heat threshold compared with AITC in vivo. Collectively, we concluded that ATR is a unique agonist of TRPA1 channels, which produces long-lasting channel activation. Our results indicated ATR-mediated anti-nociceptive effect through the desensitization of TRPA1-expressing nociceptors.     

Decrease in Fullerene Productivity Due to Air Leakage in Carbon Arc Method

Abstract

Fullerene productivity was investigated in the carbon arc discharge method when air was deliberately introduced into He-filled arc apparatus. Values of fullerene yield and production rate did not vary until the air leakage rate, denned as an increase in the ratio of air partial pressure relative to He pressure, was 0.2%/min. Fullerene productivity drastically decreased when the air leakage rate increased above 0.2%/min. Emission spectroscopic measurement of the arc plasma suggested the possibility that this decrease in productivity was related to an increase in the formation of carbon-air combined molecular species, e.g., CN, in the plasma.