基于FDK(Feldkamp,Davis and Kress)重建算法的圆轨道锥束扫描方式,因为算法的简洁性和工程实现的可行性,成为目前主要的三维工业计算机X射线断层摄影术(3D-ICT)成像技术。但受探测器长度的限制,该种技术的扫描视场小,可检构件尺寸受到...基于FDK(Feldkamp,Davis and Kress)重建算法的圆轨道锥束扫描方式,因为算法的简洁性和工程实现的可行性,成为目前主要的三维工业计算机X射线断层摄影术(3D-ICT)成像技术。但受探测器长度的限制,该种技术的扫描视场小,可检构件尺寸受到限制。为解决较大尺寸构件3D-ICT检测问题,讨论了一种扫描锥束偏转的准三代3D-ICT成像方法,推导了它基于FDK原理的滤波反投影(FBP)重建算法。计算机仿真验证了该方法的正确性。分析表明,在扫描锥束偏转两次情况下,其有效扫描视野比圆轨道扫描方式提高1.4倍以上。展开更多
This work presents a new approach for the fabrication of organic/inorganic nanohybrids as anticancer drugs by an intercalation method using S,S-bis（α,α′-dimethyl-α″-acetic acid） （trithiocarbonate） as a modifi...This work presents a new approach for the fabrication of organic/inorganic nanohybrids as anticancer drugs by an intercalation method using S,S-bis（α,α′-dimethyl-α″-acetic acid） （trithiocarbonate） as a modifier and two organoclays, such as reactive octadecylamine/MMT （montmorillonite） and non-reactive dimethyldidodecyl ammonium/MMT. The chemical and physical structures and the surface morphology of these covalently and non-covalently linked nanohybrids were investigated by FT-IR （Fourier translbrm infrared） spectroscopy, ^13C and ^29Si solid state NMR （nuclear magnetic resonance） spectroscopy, XRD （X-ray powder diffraction） and SEM （scanning electron microscopy） analyses, respectively. To evaluate the anticancer activities of the novel BATC/organoclay hybrids against MCF-7 breast cancer cells, a combination of different biochemical and biophysical testing techniques were used. Cell proliferation and cytotoxicity were detected in vitro using a real-time analysis. Cell death was confirmed by using apoptotic and necrotic analyses, the effects of which were detennined by the double staining and Annexin-V-FLUOS testing method. The results demonstrate that intercalated hybrid complexes containing a combination of various anticancer sites, such as free and complexed carboxyl, trithiocarbonate, amine and ammonium cations significantly induced cell death in breast cancer via their interactions with the DNA macromolecules of cancer cells by destroying the self-assemb｜ed structure of growing cells. Fabricated hybrid complexes may represent a new generation of effective and selective anticancer drug systems with a synthetic/natural origin for cancer chemotherapy.展开更多
The development of measurement geometry for medical X-ray computed tomography （CT） scanners was carried out from the first to the fourth-generation. This concept has also been applied for imaging of industrial proce...The development of measurement geometry for medical X-ray computed tomography （CT） scanners was carried out from the first to the fourth-generation. This concept has also been applied for imaging of industrial processes such as pipe flows or for improving design, operation, optimization and troubleshooting. Nowadays, gamma CT permits to visualize failure equipment points in three-dimensional analysis and in sections of chemical and petrochemical industries. The aim of this work is the development of the mechanical system on a third-generation industrial CT scanner to analyze laboratorial process columns which perform highly efficient separation, turning the ^6oCo, ^75Se, ^137Cs and/or ^192Ir sealed gamma-ray source（s） and the NaI（Tl） multidetector array. It also has a translation movement along the column axis to obtain as many slices of the process flow as needed. The mechanical assembly for this third-generation industrial CT scanner is comprised by strength and rigidity structural frame in stainless and carbon steels, rotating table, source shield and collimator with pneumatic exposure system, spur gear system, translator, rotary stage, drives and stepper motors. The use of suitable spur gears has given a good repeatability and high accuracy in the degree of veracity. The data acquisition boards, mechanical control interfaces, software for movement control and image reconstruction were specially development. A multiphase phantom capable to be setting with solid, liquid and gas was testing. The scanner was setting for 90 views and 19 projections for each detector totalizing 11,970 projections. Experiments to determine the linear attenuation coefficients of the phantom were carried out which applied the Lambert-Beer principle. Results showed that it was possible to distinguish between the phases even the polymethylmethacrylate and the water have very similar density and linear attenuation coefficients. It was established that the newly developed third-generation fan-beam arrangement gamma scanner unit has a good spatial resolution acceptable given the size of the used phantom in this study. The tomografic reconstruction algorithm in used 60 ~ 60 pixels images was the Alternative Minimization （AM） technique and was implemented in MATLAB and VB platforms. The mechanical system presented a good performance in terms of strength, rigidity, accuracy and repeatability with great potential to be used for education or program which dedicated to training chemical and petrochemical industry professionals and for industrial process optimization in Brazil.展开更多
Three copper wares of Han Dynasty, decorated with golden and silvery pattems in Chongqing Municipal, Three Gorges Region, were analyzed by SEM （scanning electron microscope） and EDAX （energy dispersive X-ray analy...Three copper wares of Han Dynasty, decorated with golden and silvery pattems in Chongqing Municipal, Three Gorges Region, were analyzed by SEM （scanning electron microscope） and EDAX （energy dispersive X-ray analysis）. The results reveal that mercury was used to melt gold or silver to form amalgam as late as Chinese Han Dynasty. Ancient craftsmen sheared gold foils to attain tiny gold trips that make them easy to melt into liquid mercury. After gilded, artefacts were well polished to show the brilliance of gold. As an important discovery, the silver amalgam was also detected on one copper ware. It is worth noting that silver was mixed with gold in liquid mercury to form silver amalgam which is apt to form amalgam and make silver amalgam layer stick to bronze surface tightly. This successful technology is derived from a prolonged accumulation of Chinese craftsmen on mining and metallurgical handicraft,展开更多
文摘基于FDK(Feldkamp,Davis and Kress)重建算法的圆轨道锥束扫描方式,因为算法的简洁性和工程实现的可行性,成为目前主要的三维工业计算机X射线断层摄影术(3D-ICT)成像技术。但受探测器长度的限制,该种技术的扫描视场小,可检构件尺寸受到限制。为解决较大尺寸构件3D-ICT检测问题,讨论了一种扫描锥束偏转的准三代3D-ICT成像方法,推导了它基于FDK原理的滤波反投影(FBP)重建算法。计算机仿真验证了该方法的正确性。分析表明,在扫描锥束偏转两次情况下,其有效扫描视野比圆轨道扫描方式提高1.4倍以上。
文摘This work presents a new approach for the fabrication of organic/inorganic nanohybrids as anticancer drugs by an intercalation method using S,S-bis（α,α′-dimethyl-α″-acetic acid） （trithiocarbonate） as a modifier and two organoclays, such as reactive octadecylamine/MMT （montmorillonite） and non-reactive dimethyldidodecyl ammonium/MMT. The chemical and physical structures and the surface morphology of these covalently and non-covalently linked nanohybrids were investigated by FT-IR （Fourier translbrm infrared） spectroscopy, ^13C and ^29Si solid state NMR （nuclear magnetic resonance） spectroscopy, XRD （X-ray powder diffraction） and SEM （scanning electron microscopy） analyses, respectively. To evaluate the anticancer activities of the novel BATC/organoclay hybrids against MCF-7 breast cancer cells, a combination of different biochemical and biophysical testing techniques were used. Cell proliferation and cytotoxicity were detected in vitro using a real-time analysis. Cell death was confirmed by using apoptotic and necrotic analyses, the effects of which were detennined by the double staining and Annexin-V-FLUOS testing method. The results demonstrate that intercalated hybrid complexes containing a combination of various anticancer sites, such as free and complexed carboxyl, trithiocarbonate, amine and ammonium cations significantly induced cell death in breast cancer via their interactions with the DNA macromolecules of cancer cells by destroying the self-assemb｜ed structure of growing cells. Fabricated hybrid complexes may represent a new generation of effective and selective anticancer drug systems with a synthetic/natural origin for cancer chemotherapy.
文摘The development of measurement geometry for medical X-ray computed tomography （CT） scanners was carried out from the first to the fourth-generation. This concept has also been applied for imaging of industrial processes such as pipe flows or for improving design, operation, optimization and troubleshooting. Nowadays, gamma CT permits to visualize failure equipment points in three-dimensional analysis and in sections of chemical and petrochemical industries. The aim of this work is the development of the mechanical system on a third-generation industrial CT scanner to analyze laboratorial process columns which perform highly efficient separation, turning the ^6oCo, ^75Se, ^137Cs and/or ^192Ir sealed gamma-ray source（s） and the NaI（Tl） multidetector array. It also has a translation movement along the column axis to obtain as many slices of the process flow as needed. The mechanical assembly for this third-generation industrial CT scanner is comprised by strength and rigidity structural frame in stainless and carbon steels, rotating table, source shield and collimator with pneumatic exposure system, spur gear system, translator, rotary stage, drives and stepper motors. The use of suitable spur gears has given a good repeatability and high accuracy in the degree of veracity. The data acquisition boards, mechanical control interfaces, software for movement control and image reconstruction were specially development. A multiphase phantom capable to be setting with solid, liquid and gas was testing. The scanner was setting for 90 views and 19 projections for each detector totalizing 11,970 projections. Experiments to determine the linear attenuation coefficients of the phantom were carried out which applied the Lambert-Beer principle. Results showed that it was possible to distinguish between the phases even the polymethylmethacrylate and the water have very similar density and linear attenuation coefficients. It was established that the newly developed third-generation fan-beam arrangement gamma scanner unit has a good spatial resolution acceptable given the size of the used phantom in this study. The tomografic reconstruction algorithm in used 60 ~ 60 pixels images was the Alternative Minimization （AM） technique and was implemented in MATLAB and VB platforms. The mechanical system presented a good performance in terms of strength, rigidity, accuracy and repeatability with great potential to be used for education or program which dedicated to training chemical and petrochemical industry professionals and for industrial process optimization in Brazil.
文摘Three copper wares of Han Dynasty, decorated with golden and silvery pattems in Chongqing Municipal, Three Gorges Region, were analyzed by SEM （scanning electron microscope） and EDAX （energy dispersive X-ray analysis）. The results reveal that mercury was used to melt gold or silver to form amalgam as late as Chinese Han Dynasty. Ancient craftsmen sheared gold foils to attain tiny gold trips that make them easy to melt into liquid mercury. After gilded, artefacts were well polished to show the brilliance of gold. As an important discovery, the silver amalgam was also detected on one copper ware. It is worth noting that silver was mixed with gold in liquid mercury to form silver amalgam which is apt to form amalgam and make silver amalgam layer stick to bronze surface tightly. This successful technology is derived from a prolonged accumulation of Chinese craftsmen on mining and metallurgical handicraft,
