BACKGROUND The incidence of Barrett’s esophagus(BE)in China is lower compared to the Western populations.Hence,studies conducted in the Chinese population has been limited.The current treatment options available for ...BACKGROUND The incidence of Barrett’s esophagus(BE)in China is lower compared to the Western populations.Hence,studies conducted in the Chinese population has been limited.The current treatment options available for BE treatment includes argon plasma coagulation(APC),radiofrequency ablation and cryoablation,all with varying degrees of success.AIM To determine the efficacy and safety of HybridAPC in the treatment of BE.METHODS The study cohort consisted of patients with BE who underwent HybridAPC ablation treatment.These procedures were performed by seven endoscopists from different tertiary hospitals.The duration of the procedure,curative rate,complications and recurrent rate by 1-year follow-up were recorded.RESULTS Eighty individuals were enrolled for treatment from July 2017 to June 2020,comprising of 39 males and 41 females with a median age of 54 years(range,30 to 83 years).The technical success rate of HybridAPC was 100%and the overall curative rate was 98.15%.No severe complications occurred during the operation.BE cases were classified as short-segment BE and long-segment BE.Patients with short-segment BE were all considered cured without complications.Thirty-six patients completed the one-year follow-up without recurrence.Twenty-four percent had mild dysplasia which were all resolved with one post-procedural treatment.The mean duration of the procedure was 10.94±6.52 min.CONCLUSION Treatment of BE with HybridAPC was found to be a simple and quick procedure that is safe and effective during the short-term follow-up,especially in cases of short-segment BE.This technique could be considered as a feasible alternative ablation therapy for BE.展开更多
In this work,we investigated the discharge characteristics and heating mechanisms of argon helicon plasma in different wave coupled modes with and without blue core.Spatially resolved spectroscopy and emission intensi...In this work,we investigated the discharge characteristics and heating mechanisms of argon helicon plasma in different wave coupled modes with and without blue core.Spatially resolved spectroscopy and emission intensity of argon atom and ion lines were measured via local optical emission spectroscopy,and electron density was measured experimentally by an RFcompensated Langmuir probe.The relation between the emission intensity and the electron density was obtained and the wavenumbers of helicon and’Trivelpiece-Gould’(TG)waves were calculated by solving the dispersion relation in wave modes.The results show that at least two distinct wave coupled modes appear in argon helicon plasma at increasing RF power,i.e.blue core(or BC)mode with a significant bright core of blue lights and a normal wave(NW)mode without blue core.The emission intensity of atom line 750.5 nm(lArⅠ750.5nm)is related to the electron density and tends to be saturated in wave coupled modes due to the neutral depletion,while the intensity of ion line 480.6 nm(IArⅡ480.6nm)is a function of the electron density and temperature,and increases dramatically as the RF power is increased.Theoretical analysis shows that TG waves are strongly damped at the plasma edge in NW and/or BC modes,while helicon waves are the dominant mechanism of power deposition or central heating of electrons in both modes.The formation of BC column mainly depends on the enhanced central electron heating by helicon waves rather than TG waves since the excitation of TG waves would be suppressed in this special anti-resonance region.展开更多
In this study, the reaction characteristics of reduction of calcined dolomite with ferrosilicon under argon flow to produce magnesium were studied by conducting experiments Pidgeon pellets were used to study the effec...In this study, the reaction characteristics of reduction of calcined dolomite with ferrosilicon under argon flow to produce magnesium were studied by conducting experiments Pidgeon pellets were used to study the effect of reduced temperature, argon flow, and reduced time on the conversion of calcined dolomite reduction by ferrosilicon. The results show that the conversion significantly increases with the increase in the reduction temperature and reduction time. The conversion first increases and then decreases with the increase in argon flow. The highest conversion was obtained when the argon flow rate was 3 L·min^(-1), and a nearly spherical shape, nanoscale magnesium powder was obtained. Then the characters of the circulating argon entrainment process were numerically studied by ANSYS Fluent 17. A physical model of multilayer pellet arrangement was established, and a numerical calculation model of chemical reaction, radiation, heat conduction, and convection heat transfer was constructed. This confirms that high-temperature argon can effectively strengthen the heat exchange between pellets, improve the heat transfer efficiency, and facilitate the pellets to react quickly. When the conversion is 80%, the production efficiency increased by about 28.6%. In addition, the magnesium production efficiency showed an increase tendency with the increase of the argon inlet flow rate.展开更多
文摘BACKGROUND The incidence of Barrett’s esophagus(BE)in China is lower compared to the Western populations.Hence,studies conducted in the Chinese population has been limited.The current treatment options available for BE treatment includes argon plasma coagulation(APC),radiofrequency ablation and cryoablation,all with varying degrees of success.AIM To determine the efficacy and safety of HybridAPC in the treatment of BE.METHODS The study cohort consisted of patients with BE who underwent HybridAPC ablation treatment.These procedures were performed by seven endoscopists from different tertiary hospitals.The duration of the procedure,curative rate,complications and recurrent rate by 1-year follow-up were recorded.RESULTS Eighty individuals were enrolled for treatment from July 2017 to June 2020,comprising of 39 males and 41 females with a median age of 54 years(range,30 to 83 years).The technical success rate of HybridAPC was 100%and the overall curative rate was 98.15%.No severe complications occurred during the operation.BE cases were classified as short-segment BE and long-segment BE.Patients with short-segment BE were all considered cured without complications.Thirty-six patients completed the one-year follow-up without recurrence.Twenty-four percent had mild dysplasia which were all resolved with one post-procedural treatment.The mean duration of the procedure was 10.94±6.52 min.CONCLUSION Treatment of BE with HybridAPC was found to be a simple and quick procedure that is safe and effective during the short-term follow-up,especially in cases of short-segment BE.This technique could be considered as a feasible alternative ablation therapy for BE.
基金National Natural Science Foundation of China(No.11975047)。
文摘In this work,we investigated the discharge characteristics and heating mechanisms of argon helicon plasma in different wave coupled modes with and without blue core.Spatially resolved spectroscopy and emission intensity of argon atom and ion lines were measured via local optical emission spectroscopy,and electron density was measured experimentally by an RFcompensated Langmuir probe.The relation between the emission intensity and the electron density was obtained and the wavenumbers of helicon and’Trivelpiece-Gould’(TG)waves were calculated by solving the dispersion relation in wave modes.The results show that at least two distinct wave coupled modes appear in argon helicon plasma at increasing RF power,i.e.blue core(or BC)mode with a significant bright core of blue lights and a normal wave(NW)mode without blue core.The emission intensity of atom line 750.5 nm(lArⅠ750.5nm)is related to the electron density and tends to be saturated in wave coupled modes due to the neutral depletion,while the intensity of ion line 480.6 nm(IArⅡ480.6nm)is a function of the electron density and temperature,and increases dramatically as the RF power is increased.Theoretical analysis shows that TG waves are strongly damped at the plasma edge in NW and/or BC modes,while helicon waves are the dominant mechanism of power deposition or central heating of electrons in both modes.The formation of BC column mainly depends on the enhanced central electron heating by helicon waves rather than TG waves since the excitation of TG waves would be suppressed in this special anti-resonance region.
基金supported by Key Program of the National Natural Science Foundation of China (Grant No.92062223)the National Natural Science Foundation of China (Grant No.51804277)Anhui University Natural Science Research Project (KJ20190048)。
文摘In this study, the reaction characteristics of reduction of calcined dolomite with ferrosilicon under argon flow to produce magnesium were studied by conducting experiments Pidgeon pellets were used to study the effect of reduced temperature, argon flow, and reduced time on the conversion of calcined dolomite reduction by ferrosilicon. The results show that the conversion significantly increases with the increase in the reduction temperature and reduction time. The conversion first increases and then decreases with the increase in argon flow. The highest conversion was obtained when the argon flow rate was 3 L·min^(-1), and a nearly spherical shape, nanoscale magnesium powder was obtained. Then the characters of the circulating argon entrainment process were numerically studied by ANSYS Fluent 17. A physical model of multilayer pellet arrangement was established, and a numerical calculation model of chemical reaction, radiation, heat conduction, and convection heat transfer was constructed. This confirms that high-temperature argon can effectively strengthen the heat exchange between pellets, improve the heat transfer efficiency, and facilitate the pellets to react quickly. When the conversion is 80%, the production efficiency increased by about 28.6%. In addition, the magnesium production efficiency showed an increase tendency with the increase of the argon inlet flow rate.
