OBJECTIVE To investigate the natural history of fast developing esophageal and cardia precursors.METHODS Repetitive endoscopic screenings were performed among 40-69-year-olds in the high-incidence areas for esophageal...OBJECTIVE To investigate the natural history of fast developing esophageal and cardia precursors.METHODS Repetitive endoscopic screenings were performed among 40-69-year-olds in the high-incidence areas for esophageal cancer in Shexian. RESULTS The initial diagnosis and the lag-time for 7 subsequently identified severe dysplasia （SD） subjects were as follows： in one subject 13 months after a baseline diagnosis of normal epithelium, in another subject 7 months after a baseline diagnosis of base cell hyperplasia （BCH）, in four subjects 3, 4, 4, and 10.5 months after baseline diagnosis of mild dysplasia （mD）, and in one subject 12.5 months after a baseline diagnosis of moderate dysplasia （MD）. The initial diagnosis and the lag-time for 6 subsequently identified carcinomas in situ or intramucosal carcinoma cases were： in one case 48 months after a baseline diagnosis of mD, in 2 cases 4 and 13 months after baseline diagnoses of MD, and in the other 3 cases 3.5, 9, and 17.5 months after baseline diagnoses of SD. The initial diagnosis and lag-time for 3 subsequently identified invasive cancer cases, were： in one case 50 months after a baseline diagnosis of MD, in 2 cases 14 and 19 months after baseline diagnoses of SD. In addition, during a 4-year-follow-up of 18 subjects after endoscopic mucosa resection, 9 of them were found to have developed precursors again at other sites, and also additional findings were obtained for 11 of the 16 dysplasia cases by repetitive biopsy in less than 2 months after the initial endoscopy. CONCLUSION A 5-year screening interval for BCH and mD, and a 3-year interval for MD may be too long for the fast developing precursors. Periodic screenings with shorter intervals should be considered to control the number of interval cases due to fast development, multifocal carcinogenesis, and false negative results inherent in one-time endoscopic biopsy sampling.展开更多
The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X...The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X-ray techniques and SEM （scanning electron microscopy）. The elemental neighborhood associations of a single element, P （phosphorus）, were quantified at a magnification of 3,000 ×. For each of the 170,000 pixels on the images which displayed a strong P concentration, neighborhoods from 0.1μm^2 to 12 μm^2 were examined for associated elemental concentrations. PCA （principal component analysis） revealed two significant neighborhood types associated with P in samples of pH 4, and three neighborhood types at pH 8. These neighborhoods corresponded to Mg-P associations commonly found to be chemically prevalent in river sediments impacted by agricultural operations. Discriminant analysis showed that the greatest accuracy in predicting sample pH could be achieved by using a neighborhood size of 12 ~m2. Potassium at relatively large neighborhood sizes was the element most significant in predicting pH. While many of the chemical associations in close proximity to P could be predicted and explained through mineral solubility, spatial analysis provided some interesting insights into the structure of the samples. Results also indicted differences in the spatial scale associated with different processes.展开更多
The agglomeration characteristics of river sand and wheat stalk ash mixture at various temperatures are investi- gated using a muffle furnace. The surface structural changes, as well as the elemental makeup of the sur...The agglomeration characteristics of river sand and wheat stalk ash mixture at various temperatures are investi- gated using a muffle furnace. The surface structural changes, as well as the elemental makeup of the surface and cross-section of the agglomerates, are analyzed by polarized light microscopy, scanning electron microscopy （SEM）, and energy dispersive X-ray （EDX）. Multi-phase equilibrium calculation is performed with FactSage in identifying the melting behavior of the river sand-wheat stalk ash mixture at high temperatures. No indication of agglomeration is detected below 850~C. At a temperature of 900-1000~C, however, obvious agglomeration is observed and the agglomerates solidify further as temperature increases. The presence of potassium and calcium enrichment causes the formation of a sticky sand surface that induces agglomeration. The main component of the agglomerate surface is KEO-42aO-SiO2, which melts at low temperatures. The formation of molten silicates causes particle cohesion. The main ingredient of the binding phase in the cross-section is K20-SiO2-Na20- Al2Oa--CaO; the agglomeration is not the result of the melting behavior of wheat stalk ash itself but the compre- hensive results of chemical reaction and the melting behavior at high temperatures. The multi-phase equilibrium calculations agree well with the experimental results.展开更多
New generational very-high-energy telescope arrays have been detecting more than 120 TeV γ-ray sources. Multi-wavelength observations on these z-ray sources have proven to be robust in shedding light on their nature....New generational very-high-energy telescope arrays have been detecting more than 120 TeV γ-ray sources. Multi-wavelength observations on these z-ray sources have proven to be robust in shedding light on their nature. The coming radio telescope arrays like ASKAP and FAST may find more faint （extended） radio sources due to their better sensitivities and resolutions, might identify more previously un-identified γ-ray sources and set many new targets for future deep surveys by very-highenergy ground-based telescopes like LHAASO. We in the paper summarize a list of known Galactic γ-ray Supernova Remnants （SNRs） with or without radio emissions so far, which includes some SNRs deserving top priority for future multi-wavelength observations.展开更多
基金This work was partially supported by Grantsfrom the Hebei Provincial Natural ScientificFoundation(No.C2005000797)fromFunds for the Potential y Distinguished Sci-entific Project Construction in Hebei Universi-ties.
文摘OBJECTIVE To investigate the natural history of fast developing esophageal and cardia precursors.METHODS Repetitive endoscopic screenings were performed among 40-69-year-olds in the high-incidence areas for esophageal cancer in Shexian. RESULTS The initial diagnosis and the lag-time for 7 subsequently identified severe dysplasia （SD） subjects were as follows： in one subject 13 months after a baseline diagnosis of normal epithelium, in another subject 7 months after a baseline diagnosis of base cell hyperplasia （BCH）, in four subjects 3, 4, 4, and 10.5 months after baseline diagnosis of mild dysplasia （mD）, and in one subject 12.5 months after a baseline diagnosis of moderate dysplasia （MD）. The initial diagnosis and the lag-time for 6 subsequently identified carcinomas in situ or intramucosal carcinoma cases were： in one case 48 months after a baseline diagnosis of mD, in 2 cases 4 and 13 months after baseline diagnoses of MD, and in the other 3 cases 3.5, 9, and 17.5 months after baseline diagnoses of SD. The initial diagnosis and lag-time for 3 subsequently identified invasive cancer cases, were： in one case 50 months after a baseline diagnosis of MD, in 2 cases 14 and 19 months after baseline diagnoses of SD. In addition, during a 4-year-follow-up of 18 subjects after endoscopic mucosa resection, 9 of them were found to have developed precursors again at other sites, and also additional findings were obtained for 11 of the 16 dysplasia cases by repetitive biopsy in less than 2 months after the initial endoscopy. CONCLUSION A 5-year screening interval for BCH and mD, and a 3-year interval for MD may be too long for the fast developing precursors. Periodic screenings with shorter intervals should be considered to control the number of interval cases due to fast development, multifocal carcinogenesis, and false negative results inherent in one-time endoscopic biopsy sampling.
文摘The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X-ray techniques and SEM （scanning electron microscopy）. The elemental neighborhood associations of a single element, P （phosphorus）, were quantified at a magnification of 3,000 ×. For each of the 170,000 pixels on the images which displayed a strong P concentration, neighborhoods from 0.1μm^2 to 12 μm^2 were examined for associated elemental concentrations. PCA （principal component analysis） revealed two significant neighborhood types associated with P in samples of pH 4, and three neighborhood types at pH 8. These neighborhoods corresponded to Mg-P associations commonly found to be chemically prevalent in river sediments impacted by agricultural operations. Discriminant analysis showed that the greatest accuracy in predicting sample pH could be achieved by using a neighborhood size of 12 ~m2. Potassium at relatively large neighborhood sizes was the element most significant in predicting pH. While many of the chemical associations in close proximity to P could be predicted and explained through mineral solubility, spatial analysis provided some interesting insights into the structure of the samples. Results also indicted differences in the spatial scale associated with different processes.
基金supported by National Natural Science Foundation of China(Project Code:50706055)
文摘The agglomeration characteristics of river sand and wheat stalk ash mixture at various temperatures are investi- gated using a muffle furnace. The surface structural changes, as well as the elemental makeup of the surface and cross-section of the agglomerates, are analyzed by polarized light microscopy, scanning electron microscopy （SEM）, and energy dispersive X-ray （EDX）. Multi-phase equilibrium calculation is performed with FactSage in identifying the melting behavior of the river sand-wheat stalk ash mixture at high temperatures. No indication of agglomeration is detected below 850~C. At a temperature of 900-1000~C, however, obvious agglomeration is observed and the agglomerates solidify further as temperature increases. The presence of potassium and calcium enrichment causes the formation of a sticky sand surface that induces agglomeration. The main component of the agglomerate surface is KEO-42aO-SiO2, which melts at low temperatures. The formation of molten silicates causes particle cohesion. The main ingredient of the binding phase in the cross-section is K20-SiO2-Na20- Al2Oa--CaO; the agglomeration is not the result of the melting behavior of wheat stalk ash itself but the compre- hensive results of chemical reaction and the melting behavior at high temperatures. The multi-phase equilibrium calculations agree well with the experimental results.
基金the National Natural Science Foundation of China (Grant Nos. 011241001 and 11261140641)the Programs of the Chinese Academy of Sciences (Grant Nos. 034031001(Beiren) and KJZD-EW-T01)+1 种基金the Ministry of Science and Technology Under State Key Development Program for Basic Research (Grant Nos. 2012CB821800 and 2013CB837901)grant from the John Templeton Foundation and National Astronomical Observatories (NAO) of the Chinese Academy of Sciences
文摘New generational very-high-energy telescope arrays have been detecting more than 120 TeV γ-ray sources. Multi-wavelength observations on these z-ray sources have proven to be robust in shedding light on their nature. The coming radio telescope arrays like ASKAP and FAST may find more faint （extended） radio sources due to their better sensitivities and resolutions, might identify more previously un-identified γ-ray sources and set many new targets for future deep surveys by very-highenergy ground-based telescopes like LHAASO. We in the paper summarize a list of known Galactic γ-ray Supernova Remnants （SNRs） with or without radio emissions so far, which includes some SNRs deserving top priority for future multi-wavelength observations.
