球形铁基金属玻璃单分散粒子的制备及评价

利用脉冲小孔法在He气氛下制备出了球形粒径可控的[(Fe_0.5Co_0.5)_0.75B_0.2Si_0.05]₉₆Nb₄金属玻璃单分散微粒子, 这些粒子具有粒径均匀和圆球度高等优良特点. 通过XRD、DSC以及TEM对所获得的粒子进行了检测分析, 结果表明随着粒径尺寸的减小, 微粒子的微观结构从混合相逐渐向全金属玻璃相转变, 制备的粒子均为全玻璃相, 临界尺寸小于645 μm. 通过冷却速率的计算, 得到全玻璃相微粒子的临界冷却速率为800~1100 K/s, 该速度与环境气氛的改变无关, 并且该计算值低于同成分的大块金属玻璃合金TTT曲线的测量值.     

Effect of coprecipitation temperature on the properties and activity of fibroblast growth factor-2 apatite composite layer

Fibroblast growth factor-2 (FGF-2) apatite composite layers were formed on anodically oxidized titanium (Ti) rods at temperatures lower than the previously used 37 °C to reduce the risk of the inactivation of FGF-2 in calcium phosphate solution. A two-step procedure was used to coprecipitate FGF-2 apatite composite layers on Ti rods. Continuous and homogeneous carbonate-containing low-crystalline apatite layers incorporating FGF-2 were formed on the surface of the Ti. The amounts of apatite and FGF-2 coprecipitated on the Ti rod surface decreased with decreasing coprecipitation temperature. When the coprecipitation temperatures were 15 and 20 °C, the amounts of FGF-2 precipitated on the Ti rods were 0.19 ± 0.03 and 0.20 ± 0.03 μg/cm², respectively. A cell proliferation assay for evaluating the mitogenic activity of FGF-2 immobilized in the layer showed that when FGF-2 was coprecipitated at 15 and 20 °C, the number of NIH3T3 cells cultured with FGF-2 extract was significantly larger than that at 4, 10, 25 and 30 °C. To obtain the largest amount of active FGF-2 on a Ti surface, a temperature of 15 or 20 °C should be used for coprecipitating FGF-2.     

Effect of non-genetically modified (non-GM) soy varieties on the measured value of GM soy by a quantitative PCR method

It is very important to examine the effect of non-genetically modified (non-GM) soy varieties, which constitute the matrix of the testing sample used to quantify GM soy (RRS), on the measured value of RRS by quantitative PCR methods. Therefore, we quantified the amount of RRS in powder-mixed samples containing 1 or 5% RRS prepared by using 10 different varieties of non-GM soy as the matrix. The results revealed that the measured values were not in agreement with the powder-mixing levels and that the extent of the difference depended on the variety of non-GM soy used as the matrix. The yields of DNA extracted differed among the soy varieties. On the other hand, analysis of DNA-mixed samples, that were prepared with the DNAs extracted from RRS and non-GM soy varieties, showed that the measured values of RRS were in agreement with the DNA-mixing levels. These results strongly suggest that the proportions of DNA derived from RRS and non-GM soy were not consistent with the powder-mixing ratio in the case of some non-GM soy varieties used as a matrix, resulting in the discrepancy between the measured values and the powder-mixing levels.     

Oil Microsealing: A Robust Micro‐compartmentalization Method for On‐Chip Chemical and Biological Assays

A simple and robust method to compartmentalize aqueous solutions into an array of independent microchambers is presented. The array of microchambers fabricated in poly(dimethylsiloxane) are filled with the sample solution through a microfluidic channel and then sealed with oil to isolate the microchambers from each other. A water reservoir close to the microchambers allows the maintainance and incubation of sub‐nanoliter solutions (e.g., at 37 °C) within the chambers for hours without any problem of evaporation. Once assembled, the device is self‐sustainable and can be used for different application purposes. As a demonstration, the device configuration is shown to be suitable for spatiotemporal control of the inner solution conditions by light stimulation through a photomask. This method was applied for the generation of regular EmGFP (emerald green fluorescent protein) expression arrays, selective photobleaching, photopatterning of calcium concentration, and cell culture in independent microchambers.     

A poliovirus-susceptible transgenic mouse model as a possible replacement for the monkey neurovirulence test of oral poliovirus vaccine

Two poliovirus-susceptible transgenic mouse (Tg PVR) strains, Tg1 and Tg21, were compared with the monkey test for their sensitivity to neurovirulence of live oral poliovirus vaccine (OPV). Intracerebral (i.c.) and intraspinal (i.s.) routes of inoculation were investigated to determine the most suitable combination of mouse strain and route. Evaluation of the mouse tests was performed using several indicators; clinical score and failure time were selected as the most efficient. Tg1 and Tg21 mice inoculated i.s. with type 2, and Tg21 mice inoculated i.s. with type 3 OPV were determined to be the most appropriate systems, whereas they are shown not to be suitable for type 1 OPV. The sensitivity of each of the two mouse models was at least equal to that of the monkey test, suggesting that these mouse systems might be considered as a potential replacement for the monkey test of OPV. However, more data are needed to establish regulatory criteria of acceptability for vaccine lots tested in Tg PVR mice. This is the first study conducted with Tg PVR mice with all three types of poliovirus vaccine preparations.     

Combined lung resection for advanced thoracic esophageal carcinoma

We performed lung resection together with esophagectomy in 2 patients with advanced thoracic esophageal cancer. Both patients survived more than 2 years with no evidence of disease. The first case was a 60-year-old man who had a cancer lesion in middle of the intra-thoracic esophagus (Im) and the right lower lobe of the lung was involved. In March 1989, right lower lobectomy of the lung was performed with esophagectomy. Pathologic examination showed well differentiated squamous cell carcinoma invading the lung parenchyma and intrapulmonary lymph node. Postoperatively, 44 Gy of radiation and Peplomycin cancer chemotherapy was performed. The patient survived 51 months after surgery and died of chronic myelogenous leukemia. The second case was a 60-year-old man who underwent thoracic esophagectomy with resection of the involved pericardium and right lung in February 1992. Pathologic examination showed N3 lymph node metastasis. Postoperatively, the patient received 48 Gy of radiation and was free from cancer after 30 months. In conclusion, better surgical results are expected in cases of advanced thoracic esophageal cancer with lung involvement which can be completely resected en bloc with the primary tumor even in a3 cases than in those with aortic or tracheobronchial involvement.     

Coloration mechanisms of Ag deposition‐based multicolor electrochromic device investigated by morphology of Ag deposit and its optical properties

Electrochromism, phenomenon of reversible color change induced by electrochemical redox reactions, is one of the prime candidates for full‐color electronic paper. Recently, we reported Ag‐deposition based multicolor electrochromic device showing color change between three primary colors of cyan, magenta, and yellow. These observed spectra include both absorbing and reflectance components. Therefore, it is necessary to separate these components in order to analyze coloration mechanism of the device. In this paper, coloration mechanisms of Ag deposition‐based multicolor electrochromic device were investigated in terms of measurement of the actual absorption and actual reflection of the device. Morphologies of the deposited Ag nanoparticles were also investigated by FE‐SEM, and then relationship between optical properties and deposited Ag morphologies was examined. As the results, color appearances of magenta and yellow state of the device were mainly dominated by absorption component of localized surface plasmon resonance of the deposited Ag nanoparticles. On the other hand, cyan state of the device was based on absorption as well as reflection component induced by thin film structure of the Ag deposit.     

Accumulation of radiocesium in wild mushrooms collected from a Japanese forest and cesium uptake by microorganisms isolated from the mushroom-growing soils

Mushrooms and soils samples collected from a sub-alpine forest of Mt. Fuji in Japan were measured for 137Cs and stable Cs. The ranges of 137Cs specific activities and stable Cs concentrations in the mushrooms were 291-7950 Bq kg(-1) dry weight and 4.69-58.1 mg kg(-1) dry weight, respectively. Both 137Cs specific activities and stable Cs concentrations in the mushrooms were higher than those in common agricultural plants. The 137Cs specific activities and stable Cs concentrations in the soils were 3.18-149 Bq kg(-1) dry weight and 0.618-2.18 mg kg(-1) dry weight, respectively. The appearance frequencies of filamentous actinomycetes and planktonic bacteria from the soils decreased according to increasing Cs contents in the medium. No relationship was observed between the appearance frequencies of those and the stable Cs concentrations in the soils. The filamentous actinomycetes from any soil sample could not grow in the presence of 25 mM Cs, although the planktonic bacteria from the soil samples could grow with up to 50 mM Cs in YM agar. In addition, the planktonic bacteria from approximately 70% of the soil samples could grow even in the presence of 100 mM Cs. Filamentous actinomycetes were more sensitive to Cs than planktonic bacteria. In in vitro experiments, Cs uptake by these strains of filamentous actinomycetes and planktonic bacteria was high in the presence of 5 mM CsCl and the strains accumulated Cs, the same as in mushrooms. Our results indicate that filamentous actinomycetes in the soils have higher sensitivity to Cs than planktonic bacteria, and several strains of filamentous actinomycetes have a high Cs accumulation in the presence of 5 mM Cs.     

Mycological examination of domestic unpolished rice and mycotoxin production by isolated Penicillium islandicum

Fungi growing on domestic rice were examined from April to June, 2003. One hundred samples of rice, which had been harvested in the autumn of 2002, were collected from the local market, and 15 samples of stored rice, which had been harvested in 2001 and stored in warehouses under government control, were used as samples. From each sample, 50 grains (100 grains in total) were plated on potato-dextrose agar (PDA) and malt yeast 40% sucrose agar (M40YA) containing chloramphenicol after being washed with sterile distilled water to remove any microorganisms on the surface, and incubated at 25 degrees C for a week. For most of the rice samples harvested in the preceding year, the proportion of grains infected with fungi was less than 20% of the total grains tested. In about half the samples of rice stored for one and half years, more than 80% of the grains were infected with fungi that grew on M40YA. The major genera of fungi isolated from the rice harvested in the preceding year were Penicillium and Alternaria, and those from the rice stored for one and a half years were Aspergillus, Penicillium and Eurotium. P. islandicum, A. versicolor, A. ochraceus and others were isolated as possible mycotoxin-producers in the mycoflora of domestic rice. P. islandicum was isolated from 3 samples, and 82% of the grains were infected with this fungus in one sample. All three isolates from these samples appeared to produce luteoskyrin on Czapek yeast extract agar, based on TLC and HPLC analysis.     

All-optical modulation with anomalous photovoltaic film on a Ti:LiNbO(3) waveguide modulator

An anomalous photovoltaic film formed by simultaneous oblique sputter deposition of CdTe and CdS from different directions was integrated onto LiNbO(3) and combined with a Mach-Zehnder-type interferometric waveguide modulator. Irradiation by 830-nm laser light with low intensity near 1 mW of the photovoltaic film induced anomalous photovoltages of ~5 V, which is as high as the half-wave voltage. This photovoltage was used to control the signal light in the waveguide. Modulation by external light was demonstrated with a response time of 0.1 s. Because of the presence of CdS with a photoconductive effect, the response time was much faster than that of conventional anomalous photovoltaic films formed by oblique deposition of CdTe.