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排序方式: 共有1771条查询结果,搜索用时 660 毫秒
991.
Kim SH Yamamoto T Fourmy D Fujii T 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(22):3239-3247
We present a novel method, implemented in the form of a microfluidic device, for arraying and analyzing large populations of single cells. The device contains a large array of electroactive microwells where manipulation and analysis of large population of cells are carried out. On the device, single cells can be actively trapped in the microwells by dielectrophoresis (DEP) and then lysed by electroporation (EP) for subsequent analysis of the confined cell lysates. The DEP force in the selected dimensions of the microwells could achieve efficient trapping in nearly all the microwells (95%) in less than three minutes. Moreover, the positions of the cells in the microwells are maintained even when unstable flow of liquid is applied. This makes it possible to exchange the DEP buffer to a solution that will be subsequently used for stimulating or analyzing the trapped cells. After closing the microwells, EP is conducted to lyse the trapped cells by applying short electric pulses. Tight enclosure is critical to prevent dilution, diffusion and cross contamination of the cell lysates. We demonstrated the feasibility of our approach with an enzymatic assay measuring the intracellular-galactosidase activity. The use of this method should greatly help analysis of large populations of cells at the single-cell level. Furthermore, the method offers rapidity in the trapping and analysis of multiple cell types in physiological conditions that will be important to ensure the relevance of single cell analyses. 相似文献
992.
K. Kurihara H. Kokawa S. Sato Y. S. Sato H. T. Fujii M. Kawai 《Journal of Materials Science》2011,46(12):4270-4275
Grain boundary engineering (GBE) primarily aims to prevent the initiation and propagation of intergranular degradation along
grain boundaries by frequent introduction of coincidence site lattice (CSL) boundaries into the grain boundary networks in
materials. It has been reported that GBE is effective to prevent intergranular corrosion due to sensitization in unstabilized
304 and 316 austenitic stainless steels, but the effect of GBE on intergranular corrosion in stabilized austenitic stainless
steels has not been clarified. In this study, a twin-induced GBE utilizing optimized thermomechanical processing with small
pre-strain and subsequent annealing was applied to introduce very high frequencies of CSL boundaries into a titanium-stabilized
321 austenitic stainless steel. The resulting steel showed much higher resistance to intergranular corrosion after sensitization
subsequent to carbon re-dissolution heat treatment during the ferric sulfate–sulfuric acid test than the as-received one.
The high CSL frequency resulted in a very low percolation probability of random boundary networks in the over-threshold region
and remarkable suppression of intergranular corrosion during GBE. 相似文献
993.
Qing Yang Miyoko TanakaShuhua Liang Kazuki OginoHiromichi Fujii Akihiro IshidaHirokazu Tatsuoka 《Thin solid films》2011,519(24):8538-8541
ZrO2/SiOx core/shell nanofibers with diameter ~ 50 nm were synthesized by the thermal oxidation of ZrSi2 substrates with gallium. The crystalline ZrO2 cores were grown with amorphous SiOx shells. It is proposed that the growth of crystalline ZrO2 core was guided by the prior supersaturation of Zr species in the molten gallium film, whereas the amorphous SiOx shell could be attributed to the deposition of SiO vapor on the surface of ZrO2 core. In addition, the ZrO2/SiOx core/shell nanofibers show a wide visible photoluminescence (PL) emission at 480 nm, which should originate from the SiOx shells. 相似文献
994.
Yokoya A Shikazono N Fujii K Noguchi M Urushibara A 《Radiation protection dosimetry》2011,143(2-4):219-225
To detect multiple single-strand breaks (SSBs) produced in plasmid DNA molecules by direct energy deposition from radiation tracks, we have developed a novel technique using DNA denaturation by which irradiated DNA is analysed as single-strand DNA (SS-DNA). The multiple SSBs that arise in both strands of DNA, but do not induce a double-strand break, are quantified as loss of SS-DNA using agarose gel electrophoresis. We have applied this method to X-ray and (4)He(2+) ion-irradiated samples of fully hydrated pUC18 plasmid DNA. The fractions of both SS-DNA and closed circular DNA (CC-DNA) exponentially decrease with the increasing dose of X rays and (4)He(2+) ions. The efficiency of the loss of SS-DNA was half that of CC-DNA for both types of irradiation, indicating that one of two strands in DNA is not broken when one SSB is produced in CC-DNA by irradiation. Contrary to our initial expectation, these results indicate that SSBs are not multiply induced even by high linear energy transfer radiation distributed in both strands. 相似文献
995.
Shikazono N Yokoya A Urushibara A Noguchi M Fujii K 《Radiation protection dosimetry》2011,143(2-4):181-185
Although it is widely accepted that the spatial distribution of strand breaks is highly relevant to the biological consequences of radiation, the extent to which strand breaks are clustered is not usually demonstrated directly from the experimental data. To evaluate the spatial distribution of radiation-induced strand breaks, the authors have developed a model for the generation of strand breaks after irradiation. The model assumes that (1) a radiation track has a certain probability of 'hitting' a plasmid, (2) the radiation generates strand break(s) by chance within a relatively small region that could produce double-strand breaks and (3) the number of strand breaks generated within the region follows a Poisson distribution. To find out whether the model is valid, the authors compared the calculated values with the experimental data obtained by a plasmid DNA assay. Taking into account the inherent bias of the plasmid assay, the model described well the experimental results of hydrated plasmids exposed to radiation. 相似文献
996.
E.M. Mellado K. HornungR. Srama J. KisselS.P. Armes S. Fujii 《International Journal of Impact Engineering》2011,38(6):486-494
Sulphur-containing latex micro-particles coated with an ultrathin conductive layer of polypyrrole have been accelerated in a van de Graff accelerator (up to 30 km/s) and impacted onto various target surfaces. These surfaces vary in their density (Ag and Au) as well as in their morphology by including highly porous nanostructured surfaces (“metal blacks”) in the study. After impact, the polymer chains of the latex particles are chemically degraded to much smaller molecular fragments. These fragments include both carbon- and sulphur-based species, which are detected as positive and negative ions by time-of-flight mass spectrometry. The mass spectra show that greater degradation occurs at higher velocities until finally only very simple molecular or atomic ions are formed. An effort is made to rationalise this strong velocity dependence based on energetic arguments. Furthermore, black surfaces lead to higher fragmentation than compact surfaces, which could be a consequence of much smaller impact spots. These results suggest organic molecule formation during expansion from the high pressure shock state. 相似文献
997.
Haji Aripin Seitaro Mitsudo I. Nyoman Sudiana Shinji Tani Katsuhide Sako Yutaka Fujii Teruo Saito Toshitaka Idehara Sliven Sabchevski 《Journal of Infrared, Millimeter and Terahertz Waves》2011,32(6):867-876
In this paper, we present and discuss experimental results from a microwave sintering of a silica-glass ceramic, produced
from a silica xerogel extracted from a sago waste ash. As a radiation source for the microwave heating a sub-millimeter wave
gyrotron (Gyrotron FU CW I) with an output frequency of 300 GHz has been used. The powders of silica xerogel have been dry
pressed and then sintered at temperatures ranging from 300°C to 1500°C. The influence of the sintering temperature on the
technological properties such as porosity and bulk density was studied in detail. Furthermore, X-ray diffraction (XRD) and
Fourier Transform Infrared (FTIR) spectroscopy have been used in order to study the structure of the produced silica glass-ceramics.
It has been found that the silica xerogel crystallizes at a temperature of 800°C, which is about 200°C lower than the one
observed in the conventional process. The silica xerogel samples sintered by their irradiation with a sub-millimeter wave
at 900°C for 18 minutes are fully crystallized into a silica glass-ceramic with a density of about 2.2 g/cm3 and cristobalite as a major crystalline phase. The results obtained in this study allow one to conclude that the microwave
sintering with sub-millimeter waves is an appropriate technological process for production of silica glass-ceramics from a
silica xerogel and is characterized with such advantages as shorter times of the thermal cycle, lower sintering temperatures
and higher quality of the final product. 相似文献
998.
In the course of worldwide efforts to suppress global warming, the saving of energy becomes more important. Recently, LNG (liquefied natural gas) terminals in our country have received more than 50 million tons of LNG per year. Therefore, the utilization of the cryogenic exergy in connection with the regasification of LNG gains more and more importance. The aim of this paper is the recovery of the energy consumed in liquefaction using the MGT (mirror gas-turbine), which is a new kind of combined cycle of a conventional gas-turbine worked as a topping cycle and TG (inverted Brayton cycle) as a bottoming cycle. The optimum characteristics have been calculated and it is shown that this cycle is superior to the current-use gasification systems in employing seawater heat in terms of thermal efficiency and specific output. In the present cycle, the cold LNG is used to cool the exhaust gas from a turbine of a TG, and then the exergy of the liquefied natural gas is transformed, with a very high efficiency, to electric energy. The main feature of this new concept is the removal of an evaporation system using seawater. 相似文献
999.
Kim YI Hirai S Takahashi H Goto T Ohyane C Tsugane T Konishi C Fujii T Inai S Iijima Y Aoki K Shibata D Takahashi N Kawada T 《Molecular nutrition & food research》2011,55(4):585-593
Scope: Tomato is one of the most common crops worldwide and contains many beneficial compounds that improve abnormalities of lipid metabolism. However, the molecular mechanism underlying the effect of tomato on lipid metabolism is unclear. It has been commonly accepted that peroxisome proliferator‐activated receptor α (PPARα) is one of the most important targets for ameliorating abnormalities of lipid metabolism. Therefore, we focused on the activation of PPARα and attempted to detect active compounds activating PPARα in tomato. Methods and results: To identify such active compounds, we screened fractions of tomato extracts using PPARα luciferase reporter assay. One fraction, rechromatographed‐fraction eluted in 57 min (RF57), significantly increased PPARα reporter activity, in which a single compound is detected by LC/MS analysis. On the basis of LC/MS and NMR analyses, we determined the chemical structure of the active compound in RF57 as 9‐oxo‐10(E),12(E)‐octadecadienoic acid (9‐oxo‐ODA). The RF57 fraction significantly increased the mRNA expression levels of PPARα target genes involved in fatty acid oxidation and O2 consumption in mouse primary hepatocytes. Furthermore, RF57 inhibited cellular triglyceride accumulation in the hepatocytes. Conclusion: These findings suggest that tomatoes containing 9‐oxo‐ODA that acts on PPARα are valuable for ameliorating abnormalities of lipid metabolism. 相似文献
1000.
Suehara K Kawamoto Y Fujii E Kohda J Nakano Y Yano T 《Journal of Bioscience and Bioengineering》2005,100(4):437-442
The biological treatment of wastewater discharged from a biodiesel fuel (BDF) production plant conducting alkali catalysis transesterification was investigated. BDF wastewater has a high pH and high hexane-extracted oil and low nitrogen concentrations, and inhibits the growth of microorganisms. The biological treatment of BDF wastewater is difficult because the composition of such wastewater is not suitable for microbial growth. To apply the microbiological treatment of BDF wastewater using an oil degradable yeast, Rhodotorula mucilaginosa, the pH was adjusted to 6.8 and several nutrients such as a nitrogen source (ammonium sulfate, ammonium chloride or urea), yeast extract, KH2PO4 and MgSO4.7H2O were added to the wastewater. The optimal initial concentration of yeast extract was 1 g/l and the optimal C/N ratio was between 17 and 68 when using urea as a nitrogen source. A growth inhibitor was also present in the BDF wastewater, and this growth inhibitor could be detected by measuring the solid content in an aqueous phase after the hexane extraction of the wastewater. Microorganisms could not grow at solid contents higher than 2.14 g/l in the wastewater. To avoid the growth inhibition, the BDF wastewater was diluted with the same volume of water. Oil degradation in the diluted BDF wastewater was observed and the best result was obtained under the determined optimal conditions. This treatment system is simple because no controllers, except for a temperature, are necessary. These results suggest that the biological treatment system developed for BDF wastewater is useful for small-scale BDF production plants. 相似文献