Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided p...Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided process of porous bone modeling was developed which described the design and fabrication of tissue scaffolds by considering intricate architecture,porosity and pore size.To simulate intricate bone structure,different constructive units were presented.In modeling process,bone contour was gotten from computed tomography(CT)images and was divided into two levels.Each level was represented by relatively reconstructive process.Pore size distribution was controlled by using mesh generation.The whole hexahedral mesh was reduced by unit structure,when a 3D mesh with various hexahedral elements was provided.The simulation results show that constructive structure of porous scaffold can meet the needs of clinic implants in accurate and controlled way.展开更多
Isothermal and isochronal annealing was conducted to study the thermal stability of the nanocrystalline in the surface layer of Mg alloy AZ91D induced by high-energy shot peening(HESP) .Field emission scanning electro...Isothermal and isochronal annealing was conducted to study the thermal stability of the nanocrystalline in the surface layer of Mg alloy AZ91D induced by high-energy shot peening(HESP) .Field emission scanning electron microscope(FESEM) and X-ray diffractometer were used to characterize the microstructure.Results showed that nanocrystalline produced by HESP on the surface layer of the magnesium alloy AZ91D was 60-70 nm on average.The nanocrystalline could remain stable at about 100℃,and grew up slowly between 100℃ and 200℃.When the annealing temperature reached 300℃,the growth rate of the nanocrystalline increased significantly.The kinetic coefficient n of the nanocrystalline growth was calculated to be 2-3 and the grain growth activation energy Q=39.7 kJ/mol,far less than the self-diffusion activation energy of magnesium atoms in the coarse polycrystalline material.展开更多
Various mucin-producing neoplasms originate in different abdominal and pelvic organs.Mucinous neoplasms differ from non-mucinous neoplasms because of the differences in clinical outcome and imaging appearance.Mucinous...Various mucin-producing neoplasms originate in different abdominal and pelvic organs.Mucinous neoplasms differ from non-mucinous neoplasms because of the differences in clinical outcome and imaging appearance.Mucinous carcinoma,in which at least 50%of the tumor is composed of large pools of extracellular mucin and columns of malignant cells,is associated with a worse prognosis.Signet ring cell carcinoma is characterized by large intracytoplasmic mucin vacuoles that expand in the malignant cells with the nucleus displaced to the periphery.Its prognosis is also generally poor.In contrast,intraductal papillary mucinous neoplasm of the bile duct and pancreas,which is characterized by proliferation of ductal epithelium and variable mucin production,has a better prognosis than other malignancies in the pancreaticobiliary tree.Imaging modalities play a critical role in differentiating mucinous from non-mucinous neoplasms.Due to high water content,mucin has a similar appearance to water on ultrasound(US) ,computed tomography(CT) ,and magnetic resonance imaging,except when thick and proteinaceous,and then it tends to be hypoechoic with fine internal echoes or have complex echogenicity on US,hyperdense on CT,and hyperintense on T1and hypointense on T2-weighted images,compared to water.Therefore,knowledge of characteristic mucin imaging features is helpful to diagnose various mucinproducing neoplastic conditions and to facilitate appropriate treatment.展开更多
The influence of 40 kHz ultrasound radiation on the passivation behavior of zinc in 7 M KOH is presented. The results of potentiodynamic and potentiostatic measurements combined with the current oscillation caused by ...The influence of 40 kHz ultrasound radiation on the passivation behavior of zinc in 7 M KOH is presented. The results of potentiodynamic and potentiostatic measurements combined with the current oscillation caused by the irradiation were examined to explain the mechanism and the sequence of formation of the oxide films during passivation. In this study, sonication was also used to investigate both effects of the passivation duration and passivation potential on the structure of the oxide layers; the adherence of the layers was found to depend strongly on both parameters. Scanning electron microscopy-energy dispersive X-ray （SEM-EDX） analysis of the zinc surface provided complementary information on the oxide layer composition and structure.展开更多
The TiN, TiA1N and TiA1SiN coatings were deposited on H13 hot-worked mold steel by cathodic arc ion plating （CAIP）. The morphologies, phase compositions, and nanoindcntation parameters, such as creep hardness, elast...The TiN, TiA1N and TiA1SiN coatings were deposited on H13 hot-worked mold steel by cathodic arc ion plating （CAIP）. The morphologies, phase compositions, and nanoindcntation parameters, such as creep hardness, elastic modulus and plastic de- formation energy of the coatings were analyzed with field emission scanning electron microscopy （FESEM）, X-ray diffraction （XRD） and nanoindentation testing, respectively, and the test results were compared with equation describing the indentation model. The results show that the TiN, TiA1N and TiAISiN coating surfaces were dense and composed of TiN, TiN ＋ TiA1N, TiN ＋ Si3N4 ＋ TiAIN phases, respectively. There was no spalling or cracking on the indentation surface. The creep hardness of the TiN, TiA1N and TiAISiN coatings was 7.33, 13.5, and 15.2 GPa, respectively; the corresponding hardness measured by nanoindentation was 7.09, 15.6, and 21.7 GPa, respectively; and the corresponding elastic modulus was 201.93, 172.79, and 162.77 GPa, respectively. The contact depth and elastic modulus calculated by the indentation model were close to those of the test results, but the remaining indentation parameters showed discrepancies. The sequence of plastic deformation energy was TiN 〉 TiA1N〉TiAISiN.展开更多
The growth and ordering of {5,10,15,20-tetrakis（4-bromophenyl）porphyrinato}nickel（II） （NiTBrPP） molecules on the Au（111） surface have been investigated using scanning tunnelling microscopy, X-ray absorption, c...The growth and ordering of {5,10,15,20-tetrakis（4-bromophenyl）porphyrinato}nickel（II） （NiTBrPP） molecules on the Au（111） surface have been investigated using scanning tunnelling microscopy, X-ray absorption, core-level photoemission, and microbeam low-energy electron diffraction. When deposited onto the substrate at room temperature, the NiTBrPP forms a well-ordered close-packed molecular layer in which the molecules have a flat orientation with the porphyrin macrocycle plane lying parallel to the substrate. Annealing of the NiTBrPP layer on the Au（111） surface at 525 K leads to dissociation of bromine from the porphyrin followed by the formation of covalent bonds between the phenyl substituents of the porphyrin. This results in the formation of continuous covalently bonded porphyrin networks, which are stable up to 800 K and can be recovered after exposure to ambient conditions. By controlling the experimental conditions, a robust, extended porphyrin network can be prepared on the Au（111） surface that has many potential applications such as protective coatings, in sensing or as a host structure for molecules and clusters.展开更多
Inorganic nanomaterials have attracted substantial research interest due to their unique intrinsic physicochemical properties. We highlighted recent advances in the applications of inorganic nanoparticles regarding th...Inorganic nanomaterials have attracted substantial research interest due to their unique intrinsic physicochemical properties. We highlighted recent advances in the applications of inorganic nanoparticles regarding their imaging efficacy, focusing on tumor-imaging nanomaterials such as metal-based and carbon-based nanomaterials and quantum dots. Inorganic nanoparticles gain excellent in vivo tumor-imaging functions based on their specific characteristics of strong near-infrared optical absorption and/or X-ray attenuation capability. The specific response signals from these novel nanornaterials can be captured using a series of imaging techniques, i.e., optical coherence tomography （OCT）, X-ray computed tomography （CT） imaging, two-photon luminescence （TPL）, photoacoustic tomography （PAT）, magnetic resonance imaging （MRI）, surface-enhanced Raman scattering （SERS） and positron emission tomography （PET）. In this review, we summarized the rapid development of inorganic nanomaterial applications using these analysis techniques and discussed the related safety issues of these materials.展开更多
基金Project(2011DFB70230)supported by State International Cooperation Program of ChinaProject(N110403003)supported by Basic Research Foundation of Education Ministry of China
文摘Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided process of porous bone modeling was developed which described the design and fabrication of tissue scaffolds by considering intricate architecture,porosity and pore size.To simulate intricate bone structure,different constructive units were presented.In modeling process,bone contour was gotten from computed tomography(CT)images and was divided into two levels.Each level was represented by relatively reconstructive process.Pore size distribution was controlled by using mesh generation.The whole hexahedral mesh was reduced by unit structure,when a 3D mesh with various hexahedral elements was provided.The simulation results show that constructive structure of porous scaffold can meet the needs of clinic implants in accurate and controlled way.
文摘Isothermal and isochronal annealing was conducted to study the thermal stability of the nanocrystalline in the surface layer of Mg alloy AZ91D induced by high-energy shot peening(HESP) .Field emission scanning electron microscope(FESEM) and X-ray diffractometer were used to characterize the microstructure.Results showed that nanocrystalline produced by HESP on the surface layer of the magnesium alloy AZ91D was 60-70 nm on average.The nanocrystalline could remain stable at about 100℃,and grew up slowly between 100℃ and 200℃.When the annealing temperature reached 300℃,the growth rate of the nanocrystalline increased significantly.The kinetic coefficient n of the nanocrystalline growth was calculated to be 2-3 and the grain growth activation energy Q=39.7 kJ/mol,far less than the self-diffusion activation energy of magnesium atoms in the coarse polycrystalline material.
基金Supported by A grant from the Korea Healthcare Technology R and D Project,Ministry for Health,Welfare,and Family Affairs,South Korea,A091047
文摘Various mucin-producing neoplasms originate in different abdominal and pelvic organs.Mucinous neoplasms differ from non-mucinous neoplasms because of the differences in clinical outcome and imaging appearance.Mucinous carcinoma,in which at least 50%of the tumor is composed of large pools of extracellular mucin and columns of malignant cells,is associated with a worse prognosis.Signet ring cell carcinoma is characterized by large intracytoplasmic mucin vacuoles that expand in the malignant cells with the nucleus displaced to the periphery.Its prognosis is also generally poor.In contrast,intraductal papillary mucinous neoplasm of the bile duct and pancreas,which is characterized by proliferation of ductal epithelium and variable mucin production,has a better prognosis than other malignancies in the pancreaticobiliary tree.Imaging modalities play a critical role in differentiating mucinous from non-mucinous neoplasms.Due to high water content,mucin has a similar appearance to water on ultrasound(US) ,computed tomography(CT) ,and magnetic resonance imaging,except when thick and proteinaceous,and then it tends to be hypoechoic with fine internal echoes or have complex echogenicity on US,hyperdense on CT,and hyperintense on T1and hypointense on T2-weighted images,compared to water.Therefore,knowledge of characteristic mucin imaging features is helpful to diagnose various mucinproducing neoplastic conditions and to facilitate appropriate treatment.
文摘The influence of 40 kHz ultrasound radiation on the passivation behavior of zinc in 7 M KOH is presented. The results of potentiodynamic and potentiostatic measurements combined with the current oscillation caused by the irradiation were examined to explain the mechanism and the sequence of formation of the oxide films during passivation. In this study, sonication was also used to investigate both effects of the passivation duration and passivation potential on the structure of the oxide layers; the adherence of the layers was found to depend strongly on both parameters. Scanning electron microscopy-energy dispersive X-ray （SEM-EDX） analysis of the zinc surface provided complementary information on the oxide layer composition and structure.
基金supported by the Jiangsu Province Science and Technology Support Program(Industry)(Grant No.BE2014818)
文摘The TiN, TiA1N and TiA1SiN coatings were deposited on H13 hot-worked mold steel by cathodic arc ion plating （CAIP）. The morphologies, phase compositions, and nanoindcntation parameters, such as creep hardness, elastic modulus and plastic de- formation energy of the coatings were analyzed with field emission scanning electron microscopy （FESEM）, X-ray diffraction （XRD） and nanoindentation testing, respectively, and the test results were compared with equation describing the indentation model. The results show that the TiN, TiA1N and TiAISiN coating surfaces were dense and composed of TiN, TiN ＋ TiA1N, TiN ＋ Si3N4 ＋ TiAIN phases, respectively. There was no spalling or cracking on the indentation surface. The creep hardness of the TiN, TiA1N and TiAISiN coatings was 7.33, 13.5, and 15.2 GPa, respectively; the corresponding hardness measured by nanoindentation was 7.09, 15.6, and 21.7 GPa, respectively; and the corresponding elastic modulus was 201.93, 172.79, and 162.77 GPa, respectively. The contact depth and elastic modulus calculated by the indentation model were close to those of the test results, but the remaining indentation parameters showed discrepancies. The sequence of plastic deformation energy was TiN 〉 TiA1N〉TiAISiN.
文摘The growth and ordering of {5,10,15,20-tetrakis（4-bromophenyl）porphyrinato}nickel（II） （NiTBrPP） molecules on the Au（111） surface have been investigated using scanning tunnelling microscopy, X-ray absorption, core-level photoemission, and microbeam low-energy electron diffraction. When deposited onto the substrate at room temperature, the NiTBrPP forms a well-ordered close-packed molecular layer in which the molecules have a flat orientation with the porphyrin macrocycle plane lying parallel to the substrate. Annealing of the NiTBrPP layer on the Au（111） surface at 525 K leads to dissociation of bromine from the porphyrin followed by the formation of covalent bonds between the phenyl substituents of the porphyrin. This results in the formation of continuous covalently bonded porphyrin networks, which are stable up to 800 K and can be recovered after exposure to ambient conditions. By controlling the experimental conditions, a robust, extended porphyrin network can be prepared on the Au（111） surface that has many potential applications such as protective coatings, in sensing or as a host structure for molecules and clusters.
基金supported by the Ministry of Science and Technology of China (2016YFA0201600)the National Natural Science Foundation of China (21477029)+2 种基金the Chinese Academy of Sciences (XDA09040400)Beijing Key Laboratory of Environmental Toxicology (2015HJDL01)the State Key Laboratory of Integrated Management of Pest Insects and Rodents (ChineseIPM1613)
文摘Inorganic nanomaterials have attracted substantial research interest due to their unique intrinsic physicochemical properties. We highlighted recent advances in the applications of inorganic nanoparticles regarding their imaging efficacy, focusing on tumor-imaging nanomaterials such as metal-based and carbon-based nanomaterials and quantum dots. Inorganic nanoparticles gain excellent in vivo tumor-imaging functions based on their specific characteristics of strong near-infrared optical absorption and/or X-ray attenuation capability. The specific response signals from these novel nanornaterials can be captured using a series of imaging techniques, i.e., optical coherence tomography （OCT）, X-ray computed tomography （CT） imaging, two-photon luminescence （TPL）, photoacoustic tomography （PAT）, magnetic resonance imaging （MRI）, surface-enhanced Raman scattering （SERS） and positron emission tomography （PET）. In this review, we summarized the rapid development of inorganic nanomaterial applications using these analysis techniques and discussed the related safety issues of these materials.
