荧光漂白恢复(fluorescence recovery after photobleaching,FRAP)是一种广泛使用的显微镜技术,用于可视化荧光标记分子的动力学.首先梳理了FRAP试验数据采集过程中的关键参数,并针对分子运动速率较快的样本开发了特异性的试验方法,从...荧光漂白恢复(fluorescence recovery after photobleaching,FRAP)是一种广泛使用的显微镜技术,用于可视化荧光标记分子的动力学.首先梳理了FRAP试验数据采集过程中的关键参数,并针对分子运动速率较快的样本开发了特异性的试验方法,从而得到更准确的试验结果.科学试验依赖于对大量样本的统计分析,基于NISElements软件建立了高通量FRAP试验方法,显著提升了数据采集效率并降低了人力成本.在数据分析方面构建了新型的图像高通量处理方法,实现了漂白区域自动校准和荧光强度精准分析,突破了传统手动分析瓶颈,大幅降低了人力与时间成本,为科研工作的高效推进与深度拓展提供了有力支撑.展开更多
AIM To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS W...AIM To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS We produced two consecutive tissue specimens from areas with and without cancer lesions in the surgically resected stomach of a patient with gastric cancer. One of the two tissue specimens was stained with hematoxylin and eosin and used as a reference for laser irradiation positioning by the spectroscopic method. The other specimen was left unstained and used for Raman spectroscopy analysis. RESULTS A significant Raman scattering spectrum could be obtained at all measurement points. Raman scattering spectrum intensities of 725 cm^(-1) and 782 cm^(-1), are associated with the nucleotides adenine and cytosine, respectively. The Raman scattering spectrum intensity ratios of 782 cm^(-1)/620 cm^(-1), 782 cm^(-1)/756 cm^(-1), 782 cm^(-1)/1250 cm^(-1), and 782 cm^(-1)/1263 cm^(-1) in the gastric adenocarcinoma tissue were significantly higher than those in the normal stomach tissue.CONCLUSION The results of this preliminary experiment suggest the feasibility of our spectroscopic method as a diagnostic tool for gastric cancer using unstained pathological specimens.展开更多
P-type (100) oriented silicon wafers were etched with vapors of concentrated Hydrofluoric acid in a reaction chamber under continuous vapor-flow at standard temperature and pressure. The surface morphology of the etch...P-type (100) oriented silicon wafers were etched with vapors of concentrated Hydrofluoric acid in a reaction chamber under continuous vapor-flow at standard temperature and pressure. The surface morphology of the etched samples was examined by scanning electron microscope and pore size analyzer. The radius of the pores and quantum dots were found to be 6 nm and 4 nm respectively. Etched samples emitted red luminescence when exposed to ultra violet (UV) light. The red luminescence emitted by the etched surface has been assigned to energy states induced by quantum confinement of holes.展开更多
Silicon wafers (p-type) were etched under continuous flow of HF vapors in a reaction chamber at standard temperature and pressure. Etched surface of the silicon wafer was found emitting red luminescence when exposed t...Silicon wafers (p-type) were etched under continuous flow of HF vapors in a reaction chamber at standard temperature and pressure. Etched surface of the silicon wafer was found emitting red luminescence when exposed to ultra violet (UV) light. XRD and Atomic Force Microscopy of the etched samples were carried out to study the surface of the etched silicon. It is noticed that etching has removed the stress induced atomic layers of silicon at grain boundaries and layer of porous silicon has been formed at the surface of silicon wafer which has higher inter planer distance than the silicon itself. The size of dots observed on the surface of etched silicon is of the order of few nm. The red emission from the surface of etched silicon appears to be due to the energy states induced by quantum confinement.展开更多
Aims The volume of soil beyond a plant’s roots from which that plant is able to acquire a particular nutrient depends upon the mobility of that nutrient in the soil.For this reason it has been hypothesized that the s...Aims The volume of soil beyond a plant’s roots from which that plant is able to acquire a particular nutrient depends upon the mobility of that nutrient in the soil.For this reason it has been hypothesized that the strength of competitive interactions between plants vary with soil nutrient mobility.We aimed to provide an experimental test of this hypothesis.Methods We devised two experimental systems to investigate specifically the effect of nutrient transport rates upon intraspecific competition.In the first,the exchange of rhizosphere water and dissolved nutrients between two connected pots,each containing one plant,was manipulated by alternately raising and lowering the pots.In the second experiment,the roots systems of two competing plants were separated by partitions of differing porosity,thereby varying the plants’access to water and nutrients in the other plant's rhizosphere.In this second experiment,we also applied varying amounts of nutrients to test whether higher nutrient input would reduce competition when competition for light is avoided,and applied different water levels to affect nutrient concentrations without changing nutrient supply.Important findings In both experiments,lower mobility reduced competitive effects on plant biomass and on relative growth rate(RGR),as hypothesized.In the second experiment,however,competition was more intense under high nutrient input,suggesting that low nutrient supply rates reduced the strength of the superior competitor.Competitive effects on RGR were only evident under the low water level,suggesting that under lower nutrient concentrations,competitive effects might be less pronounced.Taken together,our results provide the first direct experimental evidence that a reduction in nutrient mobility can reduce the intensity of competition between plants.展开更多
文摘荧光漂白恢复(fluorescence recovery after photobleaching,FRAP)是一种广泛使用的显微镜技术,用于可视化荧光标记分子的动力学.首先梳理了FRAP试验数据采集过程中的关键参数,并针对分子运动速率较快的样本开发了特异性的试验方法,从而得到更准确的试验结果.科学试验依赖于对大量样本的统计分析,基于NISElements软件建立了高通量FRAP试验方法,显著提升了数据采集效率并降低了人力成本.在数据分析方面构建了新型的图像高通量处理方法,实现了漂白区域自动校准和荧光强度精准分析,突破了传统手动分析瓶颈,大幅降低了人力与时间成本,为科研工作的高效推进与深度拓展提供了有力支撑.
基金Supported by the Japan Society for the Promotion of Science(JSPS)through two JSPS KAKENHI Grants-in-Aid for Scientific Research(C)No.JP26460688 and JP17K09022
文摘AIM To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS We produced two consecutive tissue specimens from areas with and without cancer lesions in the surgically resected stomach of a patient with gastric cancer. One of the two tissue specimens was stained with hematoxylin and eosin and used as a reference for laser irradiation positioning by the spectroscopic method. The other specimen was left unstained and used for Raman spectroscopy analysis. RESULTS A significant Raman scattering spectrum could be obtained at all measurement points. Raman scattering spectrum intensities of 725 cm^(-1) and 782 cm^(-1), are associated with the nucleotides adenine and cytosine, respectively. The Raman scattering spectrum intensity ratios of 782 cm^(-1)/620 cm^(-1), 782 cm^(-1)/756 cm^(-1), 782 cm^(-1)/1250 cm^(-1), and 782 cm^(-1)/1263 cm^(-1) in the gastric adenocarcinoma tissue were significantly higher than those in the normal stomach tissue.CONCLUSION The results of this preliminary experiment suggest the feasibility of our spectroscopic method as a diagnostic tool for gastric cancer using unstained pathological specimens.
文摘P-type (100) oriented silicon wafers were etched with vapors of concentrated Hydrofluoric acid in a reaction chamber under continuous vapor-flow at standard temperature and pressure. The surface morphology of the etched samples was examined by scanning electron microscope and pore size analyzer. The radius of the pores and quantum dots were found to be 6 nm and 4 nm respectively. Etched samples emitted red luminescence when exposed to ultra violet (UV) light. The red luminescence emitted by the etched surface has been assigned to energy states induced by quantum confinement of holes.
文摘Silicon wafers (p-type) were etched under continuous flow of HF vapors in a reaction chamber at standard temperature and pressure. Etched surface of the silicon wafer was found emitting red luminescence when exposed to ultra violet (UV) light. XRD and Atomic Force Microscopy of the etched samples were carried out to study the surface of the etched silicon. It is noticed that etching has removed the stress induced atomic layers of silicon at grain boundaries and layer of porous silicon has been formed at the surface of silicon wafer which has higher inter planer distance than the silicon itself. The size of dots observed on the surface of etched silicon is of the order of few nm. The red emission from the surface of etched silicon appears to be due to the energy states induced by quantum confinement.
基金Swiss National Science Foundation(31003A-112452).
文摘Aims The volume of soil beyond a plant’s roots from which that plant is able to acquire a particular nutrient depends upon the mobility of that nutrient in the soil.For this reason it has been hypothesized that the strength of competitive interactions between plants vary with soil nutrient mobility.We aimed to provide an experimental test of this hypothesis.Methods We devised two experimental systems to investigate specifically the effect of nutrient transport rates upon intraspecific competition.In the first,the exchange of rhizosphere water and dissolved nutrients between two connected pots,each containing one plant,was manipulated by alternately raising and lowering the pots.In the second experiment,the roots systems of two competing plants were separated by partitions of differing porosity,thereby varying the plants’access to water and nutrients in the other plant's rhizosphere.In this second experiment,we also applied varying amounts of nutrients to test whether higher nutrient input would reduce competition when competition for light is avoided,and applied different water levels to affect nutrient concentrations without changing nutrient supply.Important findings In both experiments,lower mobility reduced competitive effects on plant biomass and on relative growth rate(RGR),as hypothesized.In the second experiment,however,competition was more intense under high nutrient input,suggesting that low nutrient supply rates reduced the strength of the superior competitor.Competitive effects on RGR were only evident under the low water level,suggesting that under lower nutrient concentrations,competitive effects might be less pronounced.Taken together,our results provide the first direct experimental evidence that a reduction in nutrient mobility can reduce the intensity of competition between plants.
