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81.
为了研究家蚕Bombyx mori造血器官机能障碍后其血淋巴中蛋白质成分的变化,利用重离子射线局部照射家蚕幼虫的造血器官,检测了照射后家蚕血淋巴中的蛋白质成分及注射大肠杆菌后在体内诱导出现的应急蛋白量的变化。结果表明,照射蚕血淋巴中的蛋白质含量与对照蚕之间没有明显的差异。但在成分分析时发现,5龄起蚕血淋巴中70 kD附近的3条蛋白质谱带比对照蚕的浓度要高,随着个体的发育两者的浓度都上升;5龄后期则相反,对照蚕的浓度比照射蚕高;脂肪体中贮藏蛋白质的含量具有相似的变化趋势。用家蚕贮藏蛋白质SP-1及SP-2的抗血清进行免疫印迹反应的结果显示:70 kD附近的3条蛋白质谱带的最上面的一条为贮藏蛋白质SP-1,下面的二条为贮藏蛋白质SP-2;同时照射蚕血淋巴中分子量约为24 kD的蛋白质成分也发生变化,5龄前期的浓度比对照蚕低,5龄第3天几乎检测不到;全体照射与造血器官局部照射蚕之间的结果相似。照射蚕注射大肠杆菌后在体内诱导出现的应急蛋白量明显比对照蚕要少。由此认为家蚕幼虫造血器官与血淋巴中的蛋白质成分有关,造血器官的机能障碍、血球的数量减少可影响脂肪体中蛋白质的合成,从而使存在于血淋巴中的蛋白质成分发生变化。 相似文献
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PurposeThis study performed the accurate measurements of beam profiles with a new rigid board, which was consistent with the supplied reference beam profiles (RBPs) for clinical Halcyon model.MethodsPercentage depth doses (PDDs), lateral and diagonal dose profiles were measured and compared with RBPs. A water tank was set on the rigid board bridged Halcyon bore without sagging and source-to-surface distance was 90.0 cm. Field sizes were from 2.0 to 28.0 cm squares and depths of lateral and diagonal dose profiles were 1.3, 5.0, 10.0, and 20.0 cm. For the PDD, the depth of maximum dose (dmax), PDD value at depth of 10.0 cm (PDD10), and absolute dose difference (DD) between RBP and measured beam profiles (MBP) were evaluated. For lateral and diagonal dose profiles, DDs for the whole and divided areas (central, shoulder, and extended areas) defined by third derivative, and distance-to-agreement (DTA) in the penumbra area were evaluated.ResultsFor PDDs, the differences of dmax and PDD10 and DD beyond the dmax were within 1.0 mm, 0.3%, and 1.0%, respectively. For lateral and diagonal dose profiles, the DDs reached approximately 5.0% in the whole area because of penumbra area, while the DDs in the central, shoulder, and extended areas were within 1.0%, 2.0%, and 1.0%, respectively. The DTAs in the penumbra area were within 0.8 mm.ConclusionsThe supplied RBPs can be used clinically owing to the good agreement with the accurate MBPs with rigid board. 相似文献
85.
Improvements in delivery of radiation dose to target tissues in radiotherapy have increased the need for better image quality and led to a higher frequency of imaging patients. Imaging for treatment planning extends to function and motion assessment and devices are incorporated into medical linear accelerators (linacs) so that regions of tissue can be imaged at time of treatment delivery to ensure dose distributions are delivered as accurately as possible. A survey of imaging in 97 radiotherapy centres in nine countries on six continents has been undertaken with an on-line questionnaire administered through the International Commission on Radiological Protection mentorship programme to provide a snapshot of imaging practices. Responses show that all centres use CT for planning treatments and many utilise additional information from magnetic resonance imaging and positron emission tomography scans. Most centres have kV cone beam CT attached to at least some linacs and use this for the majority of treatment fractions. The imaging options available declined with the human development index (HDI) of the country, and the frequency of imaging during treatment depended more on country than treatment site with countries having lower HDIs imaging less frequently. The country with the lowest HDI had few kV imaging facilities and relied on MV planar imaging intermittently during treatment. Imaging protocols supplied by vendors are used in most centres and under half adapt exposure conditions to individual patients. Recording of patient doses, a knowledge of which is important in optimisation of imaging protocols, was limited primarily to European countries. 相似文献
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Stephen R. Decker Robert W. Sykes Geoffrey B. Turner Jason S. Lupoi Crissa Doepkke Melvin P. Tucker Logan A. Schuster Kimberly Mazza Michael E. Himmel Mark F. Davis Erica Gjersing 《Journal of visualized experiments : JoVE》2015,(103)
The conversion of lignocellulosic biomass to fuels, chemicals, and other commodities has been explored as one possible pathway toward reductions in the use of non-renewable energy sources. In order to identify which plants, out of a diverse pool, have the desired chemical traits for downstream applications, attributes, such as cellulose and lignin content, or monomeric sugar release following an enzymatic saccharification, must be compared. The experimental and data analysis protocols of the standard methods of analysis can be time-consuming, thereby limiting the number of samples that can be measured. High-throughput (HTP) methods alleviate the shortcomings of the standard methods, and permit the rapid screening of available samples to isolate those possessing the desired traits. This study illustrates the HTP sugar release and pyrolysis-molecular beam mass spectrometry pipelines employed at the National Renewable Energy Lab. These pipelines have enabled the efficient assessment of thousands of plants while decreasing experimental time and costs through reductions in labor and consumables. 相似文献
87.
Jonathan D. Poplawsky Naba R. Paudel Chen Li Chad M. Parish Donovan Leonard Yanfa Yan Stephen J. Pennycook 《Liver Transplantation》2014,4(15)
To achieve high‐efficiency polycrystalline CdTe‐based thin‐film solar cells, the CdTe absorbers must go through a post‐deposition CdCl2 heat treatment followed by a Cu diffusion step. To better understand the roles of each treatment with regard to improving grains, grain boundaries, and interfaces, CdTe solar cells with and without Cu diffusion and CdCl2 heat treatments are investigated using cross‐sectional electron beam induced current, electron backscatter diffraction, and scanning transmission electron microscope techniques. The evolution of the cross‐sectional carrier collection profile due to these treatments that cause an increase in short‐circuit current and higher open‐circuit voltage are identified. Additionally, an increased carrier collection in grain boundaries after either/both of these treatments is revealed. The increased current at the grain boundaries is shown to be due to the presence of a space charge region with an intrinsic carrier collection profile width of ≈350 nm. Scanning transmission electron microscope electron‐energy loss spectroscopy shows a decreased Te and increased Cl concentration in grain boundaries after treatment, which causes the inversion. Each treatment improves the overall carrier collection efficiency of the cell separately, and, therefore, the benefits realized by each treatment are shown to be independent of each other. 相似文献
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Roger A. Sauer 《Computer methods in biomechanics and biomedical engineering》2013,16(6):627-640
A 3D multiscale model is presented which describes the adhesion and deformation of a gecko seta. The multiscale approach combines three models at different length scales: at the top level, on the order of several micrometers, a nonlinear finite element beam model is chosen to capture the branched microstructure of the gecko seta. At the intermediate level, on the order of several nanometers, a second finite element model is used to capture the detailed behaviour of the seta tips, the so-called spatulae. At the lowest level, on the order of a few angstroms, a molecular interaction potential is used to describe the van der Waals adhesion forces between spatulae and substrate. Coarse-graining techiques are used to bridge the scale between the model levels. To illustrate and validate the proposed gecko seta model, numerical pull-off simulations are shown and compared to experimental data from the literature. 相似文献
90.
Akiko Hayashi Naoki Yokoo Toshihiro Nakamura Tomoaki Watanabe Hiromichi Nagasawa Toshihiro Kogure 《Journal of structural biology》2011,176(1):91-96
To understand the formation mechanism of crossed lamellar structures in molluskan shells, the crystallographic structural features in the shell of a bivalve, Meretrix lamarckii, were investigated using scanning electron microscopy, electron backscattered diffraction, and transmission electron microscopy with a focused ion beam sample preparation technique. Approximately 0.5 μm-thick lamellae (the second-order units) are piled up obliquely toward the growth direction to form the first-order unit and the obliquity is inverted between adjacent units along the shell thickness direction. The first-order units originate around the center of the shell, initially growing parallel to the shell and subsequently curving toward the inner or outer surfaces. The lamellae consist of aragonite granular and columnar layers, which group together to adopt the same crystal orientation forming crystallographic units (crystallites). Multiple {1 1 0} twins are common both in the granular and columnar layers. The crystallite c-axis is parallel to the columns and is inclined at angles 0–50° from the lamellar normal (dispersing among individual lamellae), toward the shell growth direction. Probably, the directions of the a- and b-axes are random in the lamellae, showing no specific orientation. 相似文献