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101.
Kim MG Shin BS Choi Y Ryu JK Shin SW Choo HW Yoo SD 《Biomedical chromatography : BMC》2012,26(5):660-665
This study describes the development of a rapid and sensitive high‐performance liquid chromatography–electrospray ionization tandem mass spectrometry (LC‐MS/MS) assay for the quantification of [6]‐gingerol in mouse plasma and application to a pharmacokinetic study after dose ranging in mice. The assay involved a protein precipitation step with acetonitrile and an isocratic elution using a mobile phase consisting of acetonitrile and water containing 0.1% formic acid (80:20 v/v). The multiple reaction monitoring was based on the transition of m/z = 277.2 → 177.1 for [6]‐gingerol and 294.2 → 137.1 for nonivamide (internal standard). The assay was validated to demonstrate the specificity, linearity, recovery, accuracy, precision and stability. The calibration curves were linear over the wide concentration range of 10–10,000 ng/mL (r ≥ 0.9988). The lower limit of quantification was 10 ng/mL using a small volume of mouse plasma (20 μL). The method was successfully applied to a pharmacokinetic study in mice after intravenous injection of [6]‐gingerol at 1.5, 3 and 6 mg/kg doses. The pharmacokinetics of [6]‐gingerol were linear over the dose range studied as demonstrated by the linear increase in area under the concentration‐time curve (AUCinf) with no significant change in the systemic clearance (Cls), volume of distribution (Vss) and elimination half‐life (t1/2) as a function of dose. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
102.
103.
为了在光栅制作中对光栅掩模占宽比及槽深加以控制,结合光刻胶在显影过程中的非线性特性,建立了光栅掩模槽形演化的数学模型,由此分析和模拟曝光量、条纹对比度对光栅槽形的影响。结果表明:在显影条件确定时,光栅掩模占宽比随光刻胶曝光量的增大而减小,条纹对比度减小,则不仅使光栅占宽比减小,同时也是使光栅槽深减小的主要原因,这样做的前提是预先通过实验和计算确定出一个曝光量上限Ec。该方法能够反映光栅掩模形状的演化规律,为全息光栅参数预测和工艺控制提供依据。 相似文献
104.
Space-graded silicon solar cells are evaluated by 1 MeV and 2 MeV electron-irradiation. The mean degradation of the maximum power (Pmax) is presented and analyzed. The degradation at both electron energies has been correlated with the displacement damage dose (Dd). A good linearity between the electron Dd and the mean Pmax degradation is obtained. The concept of Dd has also been used to predict the Si solar cell response in a low-earth-orbit (Altitude 799 km, Inclination 99o) radiation environment, considering the shielded effect of a 120 μ m-thick silica coverglass on reducing the radiation. Compared with the on-orbit data from a Si solar array of a Chinese satellite (duration from April 2007 to July 2010), a good match can be found between the on-orbit data and the predicted results using Dd methodology, indicating the method is appropriate for evaluating the radiation damage of the solar cells, and also to provide a new technique for studying radiation effects on the optoelectronic detectors used in many high energy physics applications, where harsh radiation environments produce damage in optoelectronic device materials. 相似文献
105.
A dedicated breast CT system (DBCT) is a new method for breast cancer detection proposed in recent years. In this paper, the glandular dose in the DBCT is simulated using the Monte Carlo method. The phantom shape is half ellipsoid, and a series of phantoms with different sizes, shapes and compositions were constructed. In order to optimize the spectra, monoenergy X-ray beams of 5-80 keV were used in simulation. The dose distribution of a breast phantom was studied: a higher energy beam generated more uniform distribution, and the outer parts got more dose than the inner parts. For polyenergtic spectra, four spectra of Al filters with different thicknesses were simulated, and the polyenergtic glandular dose was calculated as a spectral weighted combination of the monoenergetic dose. 相似文献
106.
Analytical and statistical calculation of gamma dose rate for the accident of losing the shield for Tehran Research Reactor 下载免费PDF全文
In this paper we study the analytical and statistical results of estimating the gamma dose rate at pool access floor in TRR when the core shield accidentally decreases to some non-permitted levels. Due to the risk of experimental techniques, we use the analytical and statistical methods. In normal conditions (no risk),the discrepancies between experiment and two methods are justified and it is found that for such problems we have to normalize these methods to experimental results as follows: the analytical method by factor 0.13 and MCNP by 1.7. 相似文献
107.
Two-dimensional particle-in-cell plasma source ion implantation of a prolate spheroid target 下载免费PDF全文
A two-dimensional particle-in-cell simulation is used to
study the time-dependent evolution of the sheath surrounding a
prolate spheroid target during a high voltage pulse in plasma source
ion implantation. Our study shows that the potential contour lines
pack more closely in the plasma sheath near the vertex of the major
axis, i.e. where a thinner sheath is formed, and a non-uniform total
ion dose distribution is incident along the surface of the prolate
spheroid target due to the focusing of ions by the potential
structure. Ion focusing takes place not only at the vertex of the
major axis, where dense potential contour lines exist, but also at
the vertex of the minor axis, where sparse contour lines exist. This
results in two peaks of the received ion dose, locating at the
vertices of the major and minor axes of the prolate spheroid target,
and an ion dose valley, staying always between the vertices, rather
than at the vertex of the minor axis. 相似文献
108.
A gel dosemeter in which ionising radiation causes a colour change was produced by modifying an existing Fricke gel system. This allows a more convenient preparation procedure and gives a better quality dosimetric system for three-dimensional (3-D) dose measurements. The role of three active components of the Ferrous sulphate Xylenol orange Gelatin (FXG) gel dosemeter is quantified with special consideration of their effect on system sensitivity and stability. The optimal composition was found to be 0.5 mM ferrous sulphate, 0.1 mM xylenol orange and 25 mM sulphuric acid. The dose response is linear in the range 0.1–30 Gy. The FXG sensitivity, derived from the gradient of the dose response curve, was found to be ΔA=0.084 cm−1 Gy−1, where A is the optical absorption coefficient at a wavelength of 585 nm, with reproducibility and 24 h stability of better than 5%. 相似文献
109.
During the 1950s to the end of the 1970s the United States Army developed the basic methodology to produce shelf-stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive “dried cooked” taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The Biogam group at the Atomic Energy Corporation of South Africa is currently producing shelf-stable irradiated meats on a commercial basis. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 45 kGy at a temperature of between −20 and −40°C to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions and can be guaranteed for more than two years as long as the integrity of the packaging is maintained. Safari operators in remote parts of Africa, mountaineers, yachtsmen, canoeists and geological survey teams currently use shelf-stable irradiated meat products produced in South Africa. 相似文献
110.
Study of total ionizing dose radiation effects on enclosed gate transistors in a commercial CMOS technology 下载免费PDF全文
This paper studies the total ionizing dose radiation effects on MOS
(metal-oxide-semiconductor) transistors with normal and enclosed gate
layout in a standard commercial CMOS (compensate MOS) bulk process.
The leakage current, threshold voltage shift, and transconductance of
the devices were monitored before and after $\gamma $-ray
irradiation. The parameters of the devices with different layout
under different bias condition during irradiation at different total
dose are investigated. The results show that the enclosed layout not
only effectively eliminates the leakage but also improves the
performance of threshold voltage and transconductance for NMOS
(n-type channel MOS) transistors. The experimental results also
indicate that analogue bias during irradiation is the worst case for
enclosed gate NMOS. There is no evident different behaviour observed
between normal PMOS (p-type channel MOS) transistors and enclosed
gate PMOS transistors. 相似文献