Transmission Electron Microscope (TEM) Technology was used to investigate the effect of 25,100 and 200 mg/kg copper on ultra-structure of root tip and leaf blade of wheat. Result showed that serious damage was found w...Transmission Electron Microscope (TEM) Technology was used to investigate the effect of 25,100 and 200 mg/kg copper on ultra-structure of root tip and leaf blade of wheat. Result showed that serious damage was found with Copper of 25,100 and 200 mg/kg. Plasmolysis,concentrated cytoplasm,chloroplast inflation,lamellar structure disturbance,capsule disappearance and disintegration,mitochondria structures ambiguity and vacuolization were all symptoms under Cu stress. There were positive correlation between concentration of coper stress and the degree of injury,and the degree of injury of copper were different in different organelles. Mitochondria were the most sensitive organelles,and there was patient difference in the same organelles of different parts.展开更多
Sipping test device is used to identify the tightness of the irradiated fuel assembly during refuelling campaign. The gas is selected as the medium and the xenon-133 as the indicating nuclide. The device consists of t...Sipping test device is used to identify the tightness of the irradiated fuel assembly during refuelling campaign. The gas is selected as the medium and the xenon-133 as the indicating nuclide. The device consists of the gas system, the γ-activity detection and measurement system, the power supply and signal system, the mechanical components and parts.The device has satisfactory functions, e.g. easy operation, indication in instrumentation, chart record and acoustic alarm, which can meet the operation demand of the nuclear reactor.展开更多
Among many reports investigating microbial diversity from environmental samples with denaturing gradient gel electrophoresis (DGGE), limited attention has been given to the effects of universal primers and DNA extract...Among many reports investigating microbial diversity from environmental samples with denaturing gradient gel electrophoresis (DGGE), limited attention has been given to the effects of universal primers and DNA extraction on the outcome of DGGE analysis. In this study, these effects were tested with 16S rRNA gene-based DGGE on a bacterial community from farming water samples. The results indicate that the number of discernable bands in the DGGE fingerprint differed with the primer pairs used; the bands produced by 63f/518r, 341f/926r and 933f/1387r primer pairs were obviously fewer than those by 968f/1401r. Also, we found that each DNA extraction method resulted in different community profiles, reflected by the number and intensity of bands in the DGGE fingerprint. Furthermore, the main bands (theoretically representing dominant bacteria) differed with the extraction methods applied. It is therefore believed that the effects of universal primers and DNA extraction should be given more attention and carefully chosen before performing an investigation into a new environment with DGGE.展开更多
The microstructure formation and grains refinement of two Mg-based alloys,i.e.AZ31 and AZ91D,were reported using an electromagnetic vibration(EMV) technique.These two alloys were solidified at various vibration freque...The microstructure formation and grains refinement of two Mg-based alloys,i.e.AZ31 and AZ91D,were reported using an electromagnetic vibration(EMV) technique.These two alloys were solidified at various vibration frequencies and the microstructures were observed.The average size of grains was quantitatively measured as a function of vibration frequencies. Moreover,the grain size distribution was outlined versus number fraction.A novel model was proposed to account for the microstructure formation and grain refinement when considering the significant difference of the electrical resistivity properties of the solid and the liquid during EMV processing in the semisolid state.The remarkable difference originates uncoupled movement between the mobile solid and the sluggish liquid,which can activate melt flow.The microstructure evolution can be well explained when the fluid flow intensity versus vibration frequency is taken into account.Moreover,the influence of the static magnetic field on texture formation is also considered,which plays an important role at higher vibration frequencies.展开更多
AIM: To establish a more stable and accurate nude mouse model of pancreatic cancer using cancer cell microencapsulation. METHODS: The assay is based on microencapsulation technology, wherein human tumor cells are enca...AIM: To establish a more stable and accurate nude mouse model of pancreatic cancer using cancer cell microencapsulation. METHODS: The assay is based on microencapsulation technology, wherein human tumor cells are encapsulated in small microcapsules (approximately 420 μm in diameter) constructed of semipermeable membranes. We implemented two kinds of subcutaneous implantation models in nude mice using the injection of single tumor cells and encapsulated pancreatic tumor cells. The size of subcutaneously implanted tumors was observed ona weekly basis using two methods, and growth curves were generated from these data. The growth and metastasis of orthotopically injected single tumor cells and encapsulated pancreatic tumor cells were evaluated at four and eight weeks postimplantation by positron emission tomography-computed tomography scan and necropsy. The pancreatic tumor samples obtained from each method were then sent for pathological examination. We evaluated differences in the rates of tumor incidence and the presence of metastasis and variations in tumor volume and tumor weight in the cancer microcapsules vs single-cell suspensions. RESULTS: Sequential in vitro observations of the microcapsules showed that the cancer cells in microcapsules proliferated well and formed spheroids at days 4 to 6. Further in vitro culture resulted in bursting of the membrane of the microcapsules and cells deviated outward and continued to grow in flasks. The optimum injection time was found to be 5 d after tumor encapsulation. In the subcutaneous implantation model, there were no significant differences in terms of tumor volume between the encapsulated pancreatic tumor cells and cells alone and rate of tumor incidence. There was a significant difference in the rate of successful im- plantation between the cancer cell microencapsulation group and the single tumor-cell suspension group (100% vs 71.43%, respectively, P = 0.0489) in the orthotropic implantation model. The former method displayed an obvious advantage in tumor mass (4th wk: 0.0461 ± 0.0399 vs 0.0313 ± 0.021, t = -0.81, P = 0.4379; 8th wk: 0.1284 ± 0.0284 vs 0.0943 ± 0.0571, t = -2.28, respectively, P = 0.0457) compared with the latter in the orthotopic implantation model. CONCLUSION: Encapsulation of pancreatic tumor cells is a reliable method for establishing a pancreatic tumor animal model.展开更多
The microfabrication technique for THz dipole antenna,"lift-off" was studied in this paper.Its procedure has been examined in detail,and discreetly tweaked.Particularly,Chlorobenzene is suggested to assist t...The microfabrication technique for THz dipole antenna,"lift-off" was studied in this paper.Its procedure has been examined in detail,and discreetly tweaked.Particularly,Chlorobenzene is suggested to assist the formation of undercut indispensible for fulfilling "lift-off".The experimental results of fabricated antennas confirm the effectiveness of this method.展开更多
基金Supported by Scientific and Technological Fund from China University of Mining and Technology (D200402)~~
文摘Transmission Electron Microscope (TEM) Technology was used to investigate the effect of 25,100 and 200 mg/kg copper on ultra-structure of root tip and leaf blade of wheat. Result showed that serious damage was found with Copper of 25,100 and 200 mg/kg. Plasmolysis,concentrated cytoplasm,chloroplast inflation,lamellar structure disturbance,capsule disappearance and disintegration,mitochondria structures ambiguity and vacuolization were all symptoms under Cu stress. There were positive correlation between concentration of coper stress and the degree of injury,and the degree of injury of copper were different in different organelles. Mitochondria were the most sensitive organelles,and there was patient difference in the same organelles of different parts.
文摘Sipping test device is used to identify the tightness of the irradiated fuel assembly during refuelling campaign. The gas is selected as the medium and the xenon-133 as the indicating nuclide. The device consists of the gas system, the γ-activity detection and measurement system, the power supply and signal system, the mechanical components and parts.The device has satisfactory functions, e.g. easy operation, indication in instrumentation, chart record and acoustic alarm, which can meet the operation demand of the nuclear reactor.
基金This work was funded by the Special Scientific Foundation of Guangdong Province (No. A305030301)was partly supported by a grant from KLFEE, Ministry of Agriculture (2003-04).
文摘Among many reports investigating microbial diversity from environmental samples with denaturing gradient gel electrophoresis (DGGE), limited attention has been given to the effects of universal primers and DNA extraction on the outcome of DGGE analysis. In this study, these effects were tested with 16S rRNA gene-based DGGE on a bacterial community from farming water samples. The results indicate that the number of discernable bands in the DGGE fingerprint differed with the primer pairs used; the bands produced by 63f/518r, 341f/926r and 933f/1387r primer pairs were obviously fewer than those by 968f/1401r. Also, we found that each DNA extraction method resulted in different community profiles, reflected by the number and intensity of bands in the DGGE fingerprint. Furthermore, the main bands (theoretically representing dominant bacteria) differed with the extraction methods applied. It is therefore believed that the effects of universal primers and DNA extraction should be given more attention and carefully chosen before performing an investigation into a new environment with DGGE.
文摘The microstructure formation and grains refinement of two Mg-based alloys,i.e.AZ31 and AZ91D,were reported using an electromagnetic vibration(EMV) technique.These two alloys were solidified at various vibration frequencies and the microstructures were observed.The average size of grains was quantitatively measured as a function of vibration frequencies. Moreover,the grain size distribution was outlined versus number fraction.A novel model was proposed to account for the microstructure formation and grain refinement when considering the significant difference of the electrical resistivity properties of the solid and the liquid during EMV processing in the semisolid state.The remarkable difference originates uncoupled movement between the mobile solid and the sluggish liquid,which can activate melt flow.The microstructure evolution can be well explained when the fluid flow intensity versus vibration frequency is taken into account.Moreover,the influence of the static magnetic field on texture formation is also considered,which plays an important role at higher vibration frequencies.
基金Supported by The Science and Technology Commission Foundation of Shanghai, No. 09140902300the Municipal Education Commission Foundation of Shanghai, No. 09YZ84
文摘AIM: To establish a more stable and accurate nude mouse model of pancreatic cancer using cancer cell microencapsulation. METHODS: The assay is based on microencapsulation technology, wherein human tumor cells are encapsulated in small microcapsules (approximately 420 μm in diameter) constructed of semipermeable membranes. We implemented two kinds of subcutaneous implantation models in nude mice using the injection of single tumor cells and encapsulated pancreatic tumor cells. The size of subcutaneously implanted tumors was observed ona weekly basis using two methods, and growth curves were generated from these data. The growth and metastasis of orthotopically injected single tumor cells and encapsulated pancreatic tumor cells were evaluated at four and eight weeks postimplantation by positron emission tomography-computed tomography scan and necropsy. The pancreatic tumor samples obtained from each method were then sent for pathological examination. We evaluated differences in the rates of tumor incidence and the presence of metastasis and variations in tumor volume and tumor weight in the cancer microcapsules vs single-cell suspensions. RESULTS: Sequential in vitro observations of the microcapsules showed that the cancer cells in microcapsules proliferated well and formed spheroids at days 4 to 6. Further in vitro culture resulted in bursting of the membrane of the microcapsules and cells deviated outward and continued to grow in flasks. The optimum injection time was found to be 5 d after tumor encapsulation. In the subcutaneous implantation model, there were no significant differences in terms of tumor volume between the encapsulated pancreatic tumor cells and cells alone and rate of tumor incidence. There was a significant difference in the rate of successful im- plantation between the cancer cell microencapsulation group and the single tumor-cell suspension group (100% vs 71.43%, respectively, P = 0.0489) in the orthotropic implantation model. The former method displayed an obvious advantage in tumor mass (4th wk: 0.0461 ± 0.0399 vs 0.0313 ± 0.021, t = -0.81, P = 0.4379; 8th wk: 0.1284 ± 0.0284 vs 0.0943 ± 0.0571, t = -2.28, respectively, P = 0.0457) compared with the latter in the orthotopic implantation model. CONCLUSION: Encapsulation of pancreatic tumor cells is a reliable method for establishing a pancreatic tumor animal model.
文摘The microfabrication technique for THz dipole antenna,"lift-off" was studied in this paper.Its procedure has been examined in detail,and discreetly tweaked.Particularly,Chlorobenzene is suggested to assist the formation of undercut indispensible for fulfilling "lift-off".The experimental results of fabricated antennas confirm the effectiveness of this method.
