Recent advances in endoscopic technology allow detailed observation of the gastric mucosa.Today,endoscopy is used in the diagnosis of gastritis to determine the presence/absence of Helicobacter pylori(H.pylori)infecti...Recent advances in endoscopic technology allow detailed observation of the gastric mucosa.Today,endoscopy is used in the diagnosis of gastritis to determine the presence/absence of Helicobacter pylori(H.pylori)infection and evaluate gastric cancer risk.In 2013,the Japan Gastroenterological Endoscopy Society advocated the Kyoto classification,a new grading system for endoscopic gastritis.The Kyoto classification organized endoscopic findings related to H.pylori infection.The Kyoto classification score is the sum of scores for five endoscopic findings(atrophy,intestinal metaplasia,enlarged folds,nodularity,and diffuse redness with or without regular arrangement of collecting venules)and ranges from 0 to 8.Atrophy,intestinal metaplasia,enlarged folds,and nodularity contribute to gastric cancer risk.Diffuse redness and regular arrangement of collecting venules are related to H.pylori infection status.In subjects without a history of H.pylori eradication,the infection rates in those with Kyoto scores of 0,1,and≥2 were 1.5%,45%,and 82%,respectively.A Kyoto classification score of 0 indicates no H.pylori infection.A Kyoto classification score of 2 or more indicates H.pylori infection.Kyoto classification scores of patients with and without gastric cancer were 4.8 and 3.8,respectively.A Kyoto classification score of 4 or more might indicate gastric cancer risk.展开更多
We present the results of systematic molecular dynamics simulations of pure aluminium melt with a well-accepted embedded atom potential. The structure and dynamics were calculated over a wide temperature range, and th...We present the results of systematic molecular dynamics simulations of pure aluminium melt with a well-accepted embedded atom potential. The structure and dynamics were calculated over a wide temperature range, and the calculated results（including the pair correlation function, self-diffusion coefficient, and viscosity） agree well with the available experimental observations. The calculated data were used to examine the Stokes–Einstein relation（SER）. The results indicate that the SER begins to break down at a temperature Tx（-1090 K） which is well above the equilibrium melting point（912.5 K）.This high-temperature breakdown is confirmed by the evolution of dynamics heterogeneity, which is characterised by the non-Gaussian parameter α2（t）. The maximum value of α 2（t）, α（2,max）, increases at an accelerating rate as the temperature falls below Tx. The development of α（2,max） was found to be related to the liquid structure change evidenced by local fivefold symmetry. Accordingly, we suggest that this high-temperature breakdown of SER has a structural origin. The results of this study are expected to make researchers reconsider the applicability of SER and promote greater understanding of the relationship between dynamics and structure.展开更多
文摘Recent advances in endoscopic technology allow detailed observation of the gastric mucosa.Today,endoscopy is used in the diagnosis of gastritis to determine the presence/absence of Helicobacter pylori(H.pylori)infection and evaluate gastric cancer risk.In 2013,the Japan Gastroenterological Endoscopy Society advocated the Kyoto classification,a new grading system for endoscopic gastritis.The Kyoto classification organized endoscopic findings related to H.pylori infection.The Kyoto classification score is the sum of scores for five endoscopic findings(atrophy,intestinal metaplasia,enlarged folds,nodularity,and diffuse redness with or without regular arrangement of collecting venules)and ranges from 0 to 8.Atrophy,intestinal metaplasia,enlarged folds,and nodularity contribute to gastric cancer risk.Diffuse redness and regular arrangement of collecting venules are related to H.pylori infection status.In subjects without a history of H.pylori eradication,the infection rates in those with Kyoto scores of 0,1,and≥2 were 1.5%,45%,and 82%,respectively.A Kyoto classification score of 0 indicates no H.pylori infection.A Kyoto classification score of 2 or more indicates H.pylori infection.Kyoto classification scores of patients with and without gastric cancer were 4.8 and 3.8,respectively.A Kyoto classification score of 4 or more might indicate gastric cancer risk.
基金supported by the National Basic Research Program of China(Grant No.2011CB012900)the National Natural Science Foundation of China(Grant No.51171115)+3 种基金the Natural Science Foundation of Shanghai City,China(Grant No.10ZR1415700)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20100073120008)the Program for New Century Excellent Talents in Universities of Chinapartially supported by Alexander von Humboldt Foundation
文摘We present the results of systematic molecular dynamics simulations of pure aluminium melt with a well-accepted embedded atom potential. The structure and dynamics were calculated over a wide temperature range, and the calculated results（including the pair correlation function, self-diffusion coefficient, and viscosity） agree well with the available experimental observations. The calculated data were used to examine the Stokes–Einstein relation（SER）. The results indicate that the SER begins to break down at a temperature Tx（-1090 K） which is well above the equilibrium melting point（912.5 K）.This high-temperature breakdown is confirmed by the evolution of dynamics heterogeneity, which is characterised by the non-Gaussian parameter α2（t）. The maximum value of α 2（t）, α（2,max）, increases at an accelerating rate as the temperature falls below Tx. The development of α（2,max） was found to be related to the liquid structure change evidenced by local fivefold symmetry. Accordingly, we suggest that this high-temperature breakdown of SER has a structural origin. The results of this study are expected to make researchers reconsider the applicability of SER and promote greater understanding of the relationship between dynamics and structure.
