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81.
A simple and rapid method for the simultaneous determination of five penicillins (ampicillin, penicillin G, penicillin V, oxacillin and cloxacillin) in muscle, liver and kidney tissues using high-performance liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) was developed. Mass spectral acquisition was done in the negative ion mode by applying selected reaction monitoring (SRM). The five penicillins were extracted with water, and the extracted solution was cleaned up on a C18 cartridge. Phenethicillin was added as an internal standard, and the extract was diluted with water for injection into the LC-ESI-MS/MS. The recoveries of the five penicillins were in the range of 77.3-99.8% from muscle, liver and kidney fortified at 10-250 ng/g. The detection limits for ampicillin were 6 ng/g in muscle and kidney and 15 ng/g in liver. For penicillin G and penicillin V, the detection limits were 2 ng/g in muscle and kidney and 5 ng/g in liver. For oxacillin and cloxacillin, the detection limits were 4 ng/g in muscle and kidney and 10 ng/g in liver. Twenty-three muscle, fourteen liver and twenty-two kidney samples from the markets were analyzed by this method. No penicillins were detected in any sample. 相似文献
82.
Oikawa D Nakanishi T Nakamura Y Takahashi Y Yamamoto T Shiba N Tobisa M Takagi T Iwamoto H Tachibana T Furuse M 《Lipids》2003,38(6):609-614
This study investigated the influence of PUFA on the properties of mouse skin. Mice (3 wk old) were given free access to oils
high in linoleic acid, CLA, or DHA for 4 wk. At the end of the experiment, their skins were compared by both biochemical and
histological methods. No significant differences in lipid and collagen contents were detected among treatments, although the
FA composition in the skin was altered depending upon the FA composition of the supplemented oils. Electron microscopy revealed
that the subcutaneous tissue layers in the CLA and DHA groups were significantly thinner than that in the high linoleic acid
group, whereas no differences in the thickness of dermis layers were observed among the three groups. These results suggest
that skin properties in mice are readily modified by dietary FA sources within 4 wk of dietary oil supplementation. 相似文献
83.
Miyuki Hayashi Hirokage Yamada Naozumi Nabeshima Kazuhiro Nagata 《International Journal of Thermophysics》2007,28(1):83-96
The temperature dependences of the velocity of sound in liquid Pb, Sn, Ge, and Si have been measured by means of the pulse
transmission technique over temperature ranges of 610–1078 K, 608–1463 K, 1215–1443 K, and 1723–1888 K, respectively. In both
liquid Pb and Sn, the velocities of sound decrease linearly with increasing temperature, which is the same temperature dependence
as shown in many other liquid metals. On the other hand, the velocities of sound in liquid Ge and Si exhibit anomalous temperature
dependences. In Ge, the velocity of sound has a distinct maximum around 1280 K and decreases linearly at higher temperatures.
In Si, the velocity of sound increases monotonically with increasing temperature in the temperature range investigated. It
is considered that these results predict that the coordination numbers of liquid Ge and Si increase with increasing temperature. 相似文献
84.
Thermoelectric Detection of Multi‐Subband Density of States in Semiconducting and Metallic Single‐Walled Carbon Nanotubes 下载免费PDF全文
85.
This paper proposed two types of speed sensorless converters that can control rotational speed and electric power. One is based on a slip frequency control system. The other is based on a vector control system. The rotational speed of the wind turbine is estimated with the phase voltage and phase current of the induction generator by the adaptive rotor flux observer. The estimated wind turbine rotational speed ωrest is used as the feedback of the speed control loop in the converter control system. Also, the estimated rotor flux ?2dest is used for the vector control. The simulation results confirm that both of them perform satisfactorily under the speed sensorless operation. The method based on the vector control system generates more electrical energy than does the method based on the slip frequency control system. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(4): 62–75, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20323 相似文献
86.
A new method for on-substrate fine positioning of microscale/mesoscale discrete components is presented, where component positions are finely adjusted using microlinear sliders and fixtures on the substrate. Each microlinear slider is actuated by vibratory impacts exerted by two pairs of microcantilever impacters. These microcantilever impacters are selectively resonated by shaking the entire substrate with a piezoelectric vibrator, requiring no need for built-in driving mechanisms such as electrostatic comb actuators, as reported previously. This selective resonance of the microcantilever impacters via an external vibration energy field provides with a very simple means of controlling forward and backward motion of the microlinear slider, facilitating assembly and disassembly of a microcomponent on a substrate. An analytical model of the device is derived in order to obtain, through the simulated annealing algorithm, an optimal design, which maximizes translation speed of the linear slider at desired external input frequencies. Prototypes of the externally resonated linear microvibromotor are fabricated using the three-layer polysilicon surface micromachining process provided by the Microelectronics Center of North Carolina, Research Triangle Park, NC, multiuser microelectromechanical processes service. These prototypes are tested for forward and backward motion via external vibration applied by an piezoelectric flexure vibrator, as well as the horizontal positioning and release of 500-μm-square polysilicon chips against a reference fixture element anchored to the substrate 相似文献
87.
Minoru Kumakura Isao Kaetsu Kazuhiro Asami Shuichi Suzuki 《Journal of Materials Science》1989,24(5):1809-1813
Porous polymer composite columns having porous structure were prepared by radiation cast-polymerization of hydrophilic monomers at low temperature and their characteristics were studied. The porosity of the polymer increased with decreasing monomer concentration. The elution time of water in the polymer column increased with increasing monomer concentration and with decreasing irradiation temperature. The elution time was dependent on the degree of hydration of the polymer. The polymer with a degree of hydration of 0.2 to 0.4 gave the minimum elution time. The elution time decreased with the addition of porous inorganic substances. 相似文献
88.
89.
Volatiles were extracted from rice plants of various growth stages with solid-phase microextraction (SPME) and analyzed by
gas chromatography-mass spectrometry (GC-MS) to identify attractants that cause invasion of the rice leaf bug Trigonotylus caelestialium (Kirkaldy) into paddy fields. The composition of volatile blends produced by rice plants changed with rice development. In
addition, volatile blend compositions differed between the panicles and the stems and leaves. The relative geranyl acetone
content was high in all plant structures analyzed. In volatiles from whole plants in the fourth-leaf stage and panicles in
the full-ripe stage, the relative content of green leaf volatiles (GLVs) was higher than that found in other rice plant structures.
In contrast, relative terpene levels emitted from whole plants in the panicle-formation stage and by panicles and stems and
leaves in the flowering stage were higher than those of other rice plant structures. However, the type of terpenes found differed
between the panicles and the stems and leaves. Relative levels of β-caryophyllene in whole plants in the panicle-formation
stage and panicles in the flowering stage were much higher than that in stems and leaves in the flowering stage. Our previous
studies demonstrated that the odor from whole plants in the panicle-formation stage and panicles in the flowering stage is
attractive to rice leaf bugs. Here, the attractiveness of β-caryophyllene to adult bugs was investigated in olfactometer assays.
Adult females were attracted to β-caryophyllene at a concentration of 0.001%, which is approximately equivalent to the concentration
produced by flowering rice panicles. However, β-caryophyllene also was present in the odor of whole plants in the fourth-leaf
stage and in stems and leaves in the flowering stage. Furthermore, the amounts of this compound emitted from these structures
were similar. Therefore, we suggest that the relative abundance of this compound in a volatile blend is important for attractance
of the bugs. 相似文献
90.
Kazuhiro Ohyama Teruo Hamaoka Greg Asher Mark Sumner 《Electrical Engineering in Japan》2009,166(1):67-81
This paper proposes a method for the design of the adaptive rotor flux observer gain to improve stability at low speed and in regenerating mode. The method is based on stability analysis, which utilizes a linearized model considering all systems, including each control loop. Therefore, the proposed method considers the effects of motor constants and control circuit constants. The stability analysis using the transfer function for the rotor speed considers the arrangement of poles and zeros and the steady‐state error. The rotor flux observer gain which improves the stability for each operating condition is ascertained. This paper also proposes a real‐time tuning method for the observer gain. The validity of the proposed method was confirmed by simulation using Matlab Simulink and by experiment. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(1): 67–81, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20715 相似文献