喹乙醇在罗非鱼肌肉组织的残留初探

应用空白罗非鱼 ,做鱼体喹乙醇残留试验。试验分为三组。一组为不食用添加喹乙醇饲料的鱼 ,另外两组为食用添加不同量喹乙醇的饲料的鱼 ,添加量分别为 5 0 0mg/kg、2 5 0 0mg/kg。喂养 15天后 ,应用液相色谱分析方法测定鱼肌肉组织的残留。第一组未检出喹乙醇。第二组和第三组在体内均有残留。并且与饲料的含量呈正比。连续测定 5天后改喂第一组鱼食用的饲料 ,在 2 4h内喹乙醇残留减少 ,在 4 8h就未测出喹乙醇的量     

MFL signals and artificial neural networks applied to detection and classification of pipe weld defects

This work evaluates the use of artificial neural networks (ANNs) for pattern recognition of magnetic flux leakage (MFL) signals in weld joints of pipelines obtained by intelligent pig. Initially the ANNs were used to distinguish the pattern signals with non-defect (ND) and signals with defects (D) along of the weld bead. In the next step the ANNs were applied to classify signal patterns with three types of defects in the weld joint: external corrosion (EC), internal corrosion (IC) and lack of penetration (LP). The defects were intentionally inserted in the weld bead of a pipeline of API 5L-X65 steel with an outer diameter of 304.8 mm. In this way, the MFL signal itself, digitized with 1025 points, was used as the ANN input. Initially the signals were used as inputs for the neural network without any type of pre-processing, later four types of pre-processing were applied to the signals: Fourier analysis, Moving-average filter, Wavelet analysis and Savitzky–Golay filter. Signal processing techniques were employed to improve the performance of the neural networks in distinguishing between the defect classes.

The results showed that it is possible to classify signals of classes D and ND using ANN with very efficient results (94.2%), as well as for corrosion (CO) and LP signals (92.5%). Also it is possible to classify the defect pattern signals: EC, IC and LP using neural networks with an average rate of success of 71.7% for the validation set.     

测量生物组织等效杨氏模量的毫米压痕仪

生物组织的弹性是诊断其是否发生病变的重要依据,杨氏模量是反映组织弹性的重要参数。以Labview为软件平台结合数据采集和运动控制等硬件设备,研制了一套测量弹性模量的毫米压痕弹性仪。以市购冷鲜牛肉、猪肉、猪肝和猪肾为试样,测量了球形压头向试样施加的负载力和对应的试样压痕深度,在对测量数据进行校准的基础上,利用基于赫兹接触力学模型的压头半径R、作用力F、压痕深度δ与试样等效杨氏模量E~*间的解析关系,得到各试样的等效杨氏模量。实验结果表明,测得的组织试样等效杨氏模量数值与文献基本相符,所设计的毫米级压痕法测试装置可用于生物组织等效杨氏模量的检测。     

Application of polymeric nanofibers in medical designs,part III: Musculoskeletal and urological tissues

Nanotechnology has potential applications in different sciences, especially in the biological sciences and medicine. The nanomaterials are applicable materials with different morphologies such as nanoparticles, nanotubes, nanowires, nanorods, and nanofibers. The development of nanofibers has greatly enhanced the scope for fabricating designs that can be potentially used in medical sciences. In part III the author summarizes the currently available applications of nanofibers in musculoskeletal and urologic tissues. The graphical abstract shows computed tomography analysis and macroscopic images of calvarial defects in rat, with the regeneration result, after four weeks, of bone healing upon implantation of scaffolds in the defect. (A and D) Control group; (B and E) poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/nanohydroxyapatite (PHBV/nHAp) scaffold; and (C and F) PHBV/nHAp scaffold with unrestricted somatic stem cells precultured in vitro.     

大口径管道清管通球、试压技术

在西气东输、西南成品油等长输管道施工的基础上,探讨了山区大口径长输管道的清管和试压技术,涉及设备的选型、管道的分段及水压试验时最大高差的确定等。     

Growth changes and tissues anatomical characteristics of giant reed （Arundo donax L.） in soil contaminated with arsenic, cadmium and lead

A greenhouse experiment was conducted to elucidate the growth changes and tissues anatomical characteristics of giant reed (Arundo donax L.), a perennial rhizomatous grass, which was cultivated for 70 d in soils contaminated with As, Cd and Pb. The results show that giant reed rapidly grows with big biomass of shoots in contaminated soil, possessing strong metal-tolerance with limited metal translocation from roots to shoots. When As, Cd and Pb concentrations in the soil are less than 254, 76.1 and 1 552 mg/kg, respectively, plant height and dried biomass are slightly reduced, the accumulation of As, Cd and Pb in shoots of giant reed is low while metal concentration in roots is high, and the anatomical characteristics of stem tissues are thick and homogeneous according to SEM images. However, plant height and dried biomass are significantly reduced and metal concentration in plant shoots and roots are significantly increased (P<0.05), the stems images become heterogeneous and the secretion in vascular bundles increases significantly when As, Cd and Pb concentrations in the soil exceed 334, 101 and 2 052 mg/kg, respectively. The giant reed is a promising, naturally occurring plant with strong metal-tolerance, which can be cultivated in soils contaminated with multiple metals for ecoremediation purposes.     

基于模型约简和GPU加速的软组织实时仿真

为了得到虚拟外科手术中人体软组织的实时变形仿真,采用了基于模态分析的模型约简方法,同时结合了GPU加速技术,实现了人体软组织的实时仿真计算,为虚拟手术提供了良好的人机交互.模型约简以有限元理论为基础,将软组织模型的动力学方程投射到约筒子空间,减少系统自由度.在实时仿真过程中,首先需在子空间中对低维动力学模型进行数值计算,然后利用GPU通用计算技术来加速重建原始空间中的形变向量.以心脏大变形实时仿真为例,验证方法的性能,实验结果表明心脏的变形仿真可以在很高的刷新率下运行.提出的模型约简和GPU加速方法,为人体软组织的变形实现了实时仿真,为虚拟手术提供了理论基础和技术支撑.     

Fertilizer value of pig slurries processed by the Promest procedure

In the Netherlands, pig slurries are processed to improve their fertilizer value as well as handling and application. The relative efficiency index (REI) of N, P and K and the stability of organic carbon (C) in test products of processed pig slurries (PPS) were determined in pot and incubation experiments. The dry and easily manageable PPS were produced according to the Promest procedure. The mineral fraction of total N varied from 60 to 88%. It consisted mainly of nitrate. About 25% of the organic N was rapidly mineralized. The REI of N varied from 66 to 92%. After application REI of P from pelletized PPS varied from 41 to 62% in the first half year. The REI of P in ground but non-pelletized PPS varied from 81 to 100%. The REI of K was estimated to be 100%. PPS contained less easily decomposable organic C than untreated pig slurry due to the anaerobic digestion step in the processing procedure. About 34% of the organic C disappeared as methane and carbon dioxide during processing. It was concluded that processing improved the fertilizer value of PPS compared with that of untreated pig slurry.     

凹球面换能器在多层生物组织中的温度场仿真

高强度聚焦超声(HIFU)治疗肿瘤是目前临床治疗的一种有效方法,治疗过程中组织内的温度测量相当重要。分析了凹球面自聚焦换能器的声场特点,采用差分法求解Pennes方程,得到凹球面换能器的声场在多层生物组织中形成的温度场,通过实验仿真,得出不同初始声压、吸收系数和热传导率等参数在多层组织内的声场和温度场的分布情况,结果表明初始声压和热传导率对焦域内温升的影响较大,该研究便于理论与临床应用相结合。