This study investigated the formulation mechanism of microspheres via internal surfactant distribution. Eudragit L100 based microspheres loaded with bovine serum albumin were prepared by solid in oil in oil emulsion s...This study investigated the formulation mechanism of microspheres via internal surfactant distribution. Eudragit L100 based microspheres loaded with bovine serum albumin were prepared by solid in oil in oil emulsion solvent evaporation method using acetone and liquid paraffin system containing sucrose stearate as a surfactant. The fabricated microspheres were evaluated for encapsulation efficiency, particle size, production yield, and in vitro release characteristics. The internal structures of microspheres were characterized using synchrotron radiation X-ray microcomputed tomography(SR-μCT). The enhanced contrast made the sucrose stearate distinguished from Eudragit to have its three dimensional(3D) distribution. Results indicated that the content and concentration determined the state of sucrose stearate and had significant influences on the release kinetics of protein. The dispersity of sucrose stearate was the primary factor that controlled the structure of the microspheres and further affected the encapsulation efficiency, effective drug loading, as well as in vitro release behavior. In conclusion, the 3D internal distribution of surfactant in microspheres and its effects on protein release behaviors have been revealed for the first time. The highly resolved 3D architecture provides new evidence for the deep understanding of the microsphere formation mechanism.展开更多
A nondestructive X-ray analysis technique combining transmission tomography, fluorescence tomography and Compton tomography based on synchrotron radiation is described. This novel technique will be an optional experim...A nondestructive X-ray analysis technique combining transmission tomography, fluorescence tomography and Compton tomography based on synchrotron radiation is described. This novel technique will be an optional experimental technique at SSRF's hard X-ray micro-focusing beamline under construction at present. An experimental result of combined X-ray tomography is obtained in NE-5A station of PF. The reconstructed images of test objects are given.展开更多
We successfully obtained 3D skeletal images of Hyla suweonensis, employing a nondestructive method by applying appropriate anesthesia and limiting the radiation dose. H. suweonensis is a tree frog endemic to Korea and...We successfully obtained 3D skeletal images of Hyla suweonensis, employing a nondestructive method by applying appropriate anesthesia and limiting the radiation dose. H. suweonensis is a tree frog endemic to Korea and is on the list of endangered species. Previous studies have employed caliper-based measurements and two-dimensional （2D） X-ray imaging for anatomical analyses of the skeletal system or bone types of H. suweonensis. In this work we reconstructed three-dimensional （3D） skeletal images of H. suweonensis, utilizing a nondestructive micro-computed tomography （micro-CT） with a short scan and low radiation dose （i.e. 4 min and 0.16 Gy）. Importantly, our approach can be applied to the imaging of 3D skeletal systems of other endangered frog species, allowing both versatile and high contrast images of anatomical structures without causing any significant damages to the living animal.展开更多
Three dimensional (3D) microscopic distributions of dolomite and calcite in a limestone sample have been analyzed with a data-constrained modeling (DCM) technique using synchrotron radiation-based multi-energy X-ray c...Three dimensional (3D) microscopic distributions of dolomite and calcite in a limestone sample have been analyzed with a data-constrained modeling (DCM) technique using synchrotron radiation-based multi-energy X-ray computed tomography (CT) data as constraints. In order to optimize the experimental parameters, X-ray CT simulations and DCM analysis of a numerical phantom consisting of calcite (CaCO3) and dolomite (CaMg(CO3)2) have been used to investigate the effects on the predicted results in relation to noise, X-ray energy and sample-to-detector distance (SDD). The simulation results indicate that the optimal X-ray energies are 25 and 35 keVs, and the SDD is 10 mm. The high resolution 3D distributions of mineral phases of a natural limestone have been obtained. The results are useful for quantitative understanding of mineral, porosity, and physical property distributions in relation to oil and gas reservoirs hosted in carbonate rocks, which account for more than half of the world’s conventional hydrocarbon resources. The case studied is also instructive for the applicability of the DCM methods for other types of composite materials with modest atomic number contrasts between the mineral phases.展开更多
In the first part of this article a more general DEI equation was derived using simple concepts. Not only does the new DEI equation explain all the problems that can be done by the DEI equation proposed by Chapman, bu...In the first part of this article a more general DEI equation was derived using simple concepts. Not only does the new DEI equation explain all the problems that can be done by the DEI equation proposed by Chapman, but also explains the problem that can not be explained with the old DEI equation, such as the noise background caused by the small angle scattering reflected by the analyzer. In the second part, a DEI-PI-CT formula has been proposed and the contour contrast caused by the extinction of refraction beam has been qualitatively explained, and then based on the work of Ando's group two formulae of refraction CT with DEI method has been proposed. Combining one refraction CT formula proposed by Dilmanian with the two refraction CT formulae proposed by us, the whole framework of CT algorithm can be made to reconstruct three components of the gradient of refractive index.展开更多
In line X-ray phase contrast micro-computed tomography （IL-XPCT）, which can be implemented at third generation synchrotron radiation sources or by using a micro-focus X-ray tube, is a powerful technique for non-dest...In line X-ray phase contrast micro-computed tomography （IL-XPCT）, which can be implemented at third generation synchrotron radiation sources or by using a micro-focus X-ray tube, is a powerful technique for non-destructive, high-resolution investigations of a broad variety of materials. At the Shanghai Synchrotron Radiation Facility （SSRF）, the X-ray Imaging and Biomedical Applications Beamline was built and started regular user operation in May 2009. Both qualitative （without phase retrieval） and quantitative （with phase retrieval） three-dimensional IL-XPCT experimental techniques have been established at the beamline IL-XPCT experiments of a test sample （plastic pipes） used to evaluate the technique, and of a biological sample （locust） at the beamline are reported. Two series of images, qualitative and quantitative, including tomographic slices and three-dimensional rendering images were obtained. In qualitative images, there is a strong edge-enhancement which leads to very clear sample contours, while in quantitative images, the edge-enhancement fades but quantitative measurement of sample＇s phase information could be achieved. The experiments demonstrate that the combination of qualitative and quantitative images is useful for biological sample studies.展开更多
基金the financial support from the National Natural Science Foundation of China(No.81430087)the National Science and Technology Major Project(2013ZX09402103)
文摘This study investigated the formulation mechanism of microspheres via internal surfactant distribution. Eudragit L100 based microspheres loaded with bovine serum albumin were prepared by solid in oil in oil emulsion solvent evaporation method using acetone and liquid paraffin system containing sucrose stearate as a surfactant. The fabricated microspheres were evaluated for encapsulation efficiency, particle size, production yield, and in vitro release characteristics. The internal structures of microspheres were characterized using synchrotron radiation X-ray microcomputed tomography(SR-μCT). The enhanced contrast made the sucrose stearate distinguished from Eudragit to have its three dimensional(3D) distribution. Results indicated that the content and concentration determined the state of sucrose stearate and had significant influences on the release kinetics of protein. The dispersity of sucrose stearate was the primary factor that controlled the structure of the microspheres and further affected the encapsulation efficiency, effective drug loading, as well as in vitro release behavior. In conclusion, the 3D internal distribution of surfactant in microspheres and its effects on protein release behaviors have been revealed for the first time. The highly resolved 3D architecture provides new evidence for the deep understanding of the microsphere formation mechanism.
文摘A nondestructive X-ray analysis technique combining transmission tomography, fluorescence tomography and Compton tomography based on synchrotron radiation is described. This novel technique will be an optional experimental technique at SSRF's hard X-ray micro-focusing beamline under construction at present. An experimental result of combined X-ray tomography is obtained in NE-5A station of PF. The reconstructed images of test objects are given.
基金supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (grant numbers: NRF-2015R1C1A1A01052498 and NRF2014R1A1A1006010)
文摘We successfully obtained 3D skeletal images of Hyla suweonensis, employing a nondestructive method by applying appropriate anesthesia and limiting the radiation dose. H. suweonensis is a tree frog endemic to Korea and is on the list of endangered species. Previous studies have employed caliper-based measurements and two-dimensional （2D） X-ray imaging for anatomical analyses of the skeletal system or bone types of H. suweonensis. In this work we reconstructed three-dimensional （3D） skeletal images of H. suweonensis, utilizing a nondestructive micro-computed tomography （micro-CT） with a short scan and low radiation dose （i.e. 4 min and 0.16 Gy）. Importantly, our approach can be applied to the imaging of 3D skeletal systems of other endangered frog species, allowing both versatile and high contrast images of anatomical structures without causing any significant damages to the living animal.
文摘Three dimensional (3D) microscopic distributions of dolomite and calcite in a limestone sample have been analyzed with a data-constrained modeling (DCM) technique using synchrotron radiation-based multi-energy X-ray computed tomography (CT) data as constraints. In order to optimize the experimental parameters, X-ray CT simulations and DCM analysis of a numerical phantom consisting of calcite (CaCO3) and dolomite (CaMg(CO3)2) have been used to investigate the effects on the predicted results in relation to noise, X-ray energy and sample-to-detector distance (SDD). The simulation results indicate that the optimal X-ray energies are 25 and 35 keVs, and the SDD is 10 mm. The high resolution 3D distributions of mineral phases of a natural limestone have been obtained. The results are useful for quantitative understanding of mineral, porosity, and physical property distributions in relation to oil and gas reservoirs hosted in carbonate rocks, which account for more than half of the world’s conventional hydrocarbon resources. The case studied is also instructive for the applicability of the DCM methods for other types of composite materials with modest atomic number contrasts between the mineral phases.
基金Supported by the National Outstanding Youth Fund (10125523 to Z.Wu.)the Key Important Nano-Research Project (90206032)+1 种基金the Key Important Project of the National Natural Science Foundation of China (10490190,10490194) by Knowledge Innovation Fund of IHEP.
文摘In the first part of this article a more general DEI equation was derived using simple concepts. Not only does the new DEI equation explain all the problems that can be done by the DEI equation proposed by Chapman, but also explains the problem that can not be explained with the old DEI equation, such as the noise background caused by the small angle scattering reflected by the analyzer. In the second part, a DEI-PI-CT formula has been proposed and the contour contrast caused by the extinction of refraction beam has been qualitatively explained, and then based on the work of Ando's group two formulae of refraction CT with DEI method has been proposed. Combining one refraction CT formula proposed by Dilmanian with the two refraction CT formulae proposed by us, the whole framework of CT algorithm can be made to reconstruct three components of the gradient of refractive index.
基金Supported by the Major Research Plan of the National Natural Science Foundation of China (No.2010CB834301)the National Natural Science Foundation of China (Nos.10805071 and 10705020)+2 种基金the Chinese Academy of Sciences Key Project of International Co-operation (No.GJHZ09058)the Shanghai Key Project of Basic Research (No.08JC1411900)supported by ICTP TRIL Programme
文摘In line X-ray phase contrast micro-computed tomography （IL-XPCT）, which can be implemented at third generation synchrotron radiation sources or by using a micro-focus X-ray tube, is a powerful technique for non-destructive, high-resolution investigations of a broad variety of materials. At the Shanghai Synchrotron Radiation Facility （SSRF）, the X-ray Imaging and Biomedical Applications Beamline was built and started regular user operation in May 2009. Both qualitative （without phase retrieval） and quantitative （with phase retrieval） three-dimensional IL-XPCT experimental techniques have been established at the beamline IL-XPCT experiments of a test sample （plastic pipes） used to evaluate the technique, and of a biological sample （locust） at the beamline are reported. Two series of images, qualitative and quantitative, including tomographic slices and three-dimensional rendering images were obtained. In qualitative images, there is a strong edge-enhancement which leads to very clear sample contours, while in quantitative images, the edge-enhancement fades but quantitative measurement of sample＇s phase information could be achieved. The experiments demonstrate that the combination of qualitative and quantitative images is useful for biological sample studies.
