A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths （OF,） to the different positions of the spherical [60]fullerene （C60） through...A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths （OF,） to the different positions of the spherical [60]fullerene （C60） through a rigid linkage. The conjugates were characterized by IH-NMR, 13C-NMR, FTIR, EA and MALDI-TOF mass spectrometry. The optical and electronic properties of the conjugates were studied by UV-Vis absorption spectroscopy, fluorescence spectrometry, and cyclic voltammetry. The results from UV-Vis absorption spectroscopy and cyclic voltammetry indicated that the energy profiles of C60 and OFn remained unchanged when different lengths of OFn were attached to C60. The electron affinities of the OFn-C60 conjugates were close to that of C60, while slight electronic interaction was found between the two individual chromophores （C60 and OFn） in their ground states. The fluorescence spectra exhibited a complete fluorescence quenching in the toluene solution, suggesting an effective energy transfer from OFn to C60. It presents a systematic study on the self- assembly, structure-property relationship, and potential technical applications of the conjugates.展开更多
Monosialotetrahexosylganglioside（GM1）is a type of glycosphingolipid containing sialic acid that is closely related to cell-cell recognition,adhesion and signal conduction.GM1is mainly composed of ceramide and oligos...Monosialotetrahexosylganglioside（GM1）is a type of glycosphingolipid containing sialic acid that is closely related to cell-cell recognition,adhesion and signal conduction.GM1is mainly composed of ceramide and oligosaccharide chains,and it is the only ganglioside that can permeate the bloodbrain barrier.展开更多
The objectives of this study are to evaluate the dosimetric impact of hip prosthesis using ELEKTA linac X-rays and compare the dose perturbations of metallic and nonmetallic hip prostheses. The local dose distribution...The objectives of this study are to evaluate the dosimetric impact of hip prosthesis using ELEKTA linac X-rays and compare the dose perturbations of metallic and nonmetallic hip prostheses. The local dose distributions of typical hip prostheses were calculated for 4, 8, and 15 MV beams by Geant4. Three prosthesis materials were selected in calculation to reveal the relation between material type and local dose perturbations of prostheses. Furthermore,the effect of nominal energy on prosthesis perturbation was also discussed and analyzed. Taking the calculated dose to the hip joint as reference, considerable differences were observed between prostheses and hip joints. In the prosthesis shadow region, the relative dose decreasing was up to 36, 21, and 16 % for the Co–Cr–Mo alloy, titanium alloy, and ceramic prostheses, respectively. In backscattering region, the relative dose increasing was about1–7 %. Overall, the results show that the dose perturbation effect of prostheses was mainly determined by material type, nominal energy, and density. Among these typical hip prostheses, ceramic prosthesis introduces the lowest dose perturbations.展开更多
基金financially supported by the International Science&Technology Cooperation Program of China(No.2010DFB70470)the Natural Science Foundation of Shanghai(No.10ZR1407600)
文摘A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths （OF,） to the different positions of the spherical [60]fullerene （C60） through a rigid linkage. The conjugates were characterized by IH-NMR, 13C-NMR, FTIR, EA and MALDI-TOF mass spectrometry. The optical and electronic properties of the conjugates were studied by UV-Vis absorption spectroscopy, fluorescence spectrometry, and cyclic voltammetry. The results from UV-Vis absorption spectroscopy and cyclic voltammetry indicated that the energy profiles of C60 and OFn remained unchanged when different lengths of OFn were attached to C60. The electron affinities of the OFn-C60 conjugates were close to that of C60, while slight electronic interaction was found between the two individual chromophores （C60 and OFn） in their ground states. The fluorescence spectra exhibited a complete fluorescence quenching in the toluene solution, suggesting an effective energy transfer from OFn to C60. It presents a systematic study on the self- assembly, structure-property relationship, and potential technical applications of the conjugates.
基金supported by the National Natural Science Foundation of China(General Program),No.81373095
文摘Monosialotetrahexosylganglioside（GM1）is a type of glycosphingolipid containing sialic acid that is closely related to cell-cell recognition,adhesion and signal conduction.GM1is mainly composed of ceramide and oligosaccharide chains,and it is the only ganglioside that can permeate the bloodbrain barrier.
基金supported by Heilongjiang Province Natural Science Foundation (No. A200805)the Education Department of Heilongjiang Province (No. 12521425)the postdoctoral research start-up funds of Heilongjiang Province (No. LBHQ11013)
文摘The objectives of this study are to evaluate the dosimetric impact of hip prosthesis using ELEKTA linac X-rays and compare the dose perturbations of metallic and nonmetallic hip prostheses. The local dose distributions of typical hip prostheses were calculated for 4, 8, and 15 MV beams by Geant4. Three prosthesis materials were selected in calculation to reveal the relation between material type and local dose perturbations of prostheses. Furthermore,the effect of nominal energy on prosthesis perturbation was also discussed and analyzed. Taking the calculated dose to the hip joint as reference, considerable differences were observed between prostheses and hip joints. In the prosthesis shadow region, the relative dose decreasing was up to 36, 21, and 16 % for the Co–Cr–Mo alloy, titanium alloy, and ceramic prostheses, respectively. In backscattering region, the relative dose increasing was about1–7 %. Overall, the results show that the dose perturbation effect of prostheses was mainly determined by material type, nominal energy, and density. Among these typical hip prostheses, ceramic prosthesis introduces the lowest dose perturbations.
