AIM： To compare the efficacy of the proton-pump inhibitor, rabeprazole, with that of the H2-receptor antagonist, ranitidine, as on-demand therapy for relieving symptoms associated with non-erosive reflux disease （N...AIM： To compare the efficacy of the proton-pump inhibitor, rabeprazole, with that of the H2-receptor antagonist, ranitidine, as on-demand therapy for relieving symptoms associated with non-erosive reflux disease （NEED）.METHODS： This is a single center, prospective, randomized, open-label trial of on-demand therapy with rabeprazole （group A） vs ranitidine （group B） for 4 wk. Eighty-three patients who presented to the American University of Beirut Medical Center with persistent gas- troesophageal reflux disease （GERD） symptoms and a normal upper gastrointestinal endoscopy were eligible for the study. Patients in group A （n = 44） were al-lowed a maximum rabeprazole dose of 20 mg twice daily, while those in group B （n = 39） were allowed a maximum ranitidine dose of 300 mg twice daily. Ef- ficacy was assessed by patient evaluation of global symptom relief, scores of the SF-36 quality of life （QoL） questionnaires, total number of pills used, and number of medication-free days.RESULTS： Among the 83 patients who were enrolled in the study, 76 patients （40 in the rabeprazole group and 36 in the ranitidine group） completed the 4-wk trial. Baseline characteristics were comparable between both groups. After 4 wk, there was no significant difference in the subjective global symptom relief between the rabeprazole and the ranitidine groups （71.4% vs 65.4%, respectively; P = 0.9）. There were no statistically significant differences between mean cumulative scores of the SF-36 QoL questionnaire for the two study groups （rabeprazole 22.40±27.53 vs ranitidine 17.28 ± 37.06; P = 0.582）. There was no significant difference in the mean number of pills used （rabeprazole 35.70±29.75 vs ranitidine 32.86±26.98; P = 0.66）. There was also no statistically significant difference in the mean number of medication-free days between both groups.CONCLUSION： Rabeprazole has a comparable efficacy compared to ranitidine when given on-demand for the treatment of NERD. Both medications were associated with improved quality of life.展开更多
A phenomenological low-filed mobility model is developed to describe the dependence ot the carrier molgmty on me gate to source bias applied for AIGaN/GaN high electron mobility transistor. The results show excellent ...A phenomenological low-filed mobility model is developed to describe the dependence ot the carrier molgmty on me gate to source bias applied for AIGaN/GaN high electron mobility transistor. The results show excellent agreement with experimental data, when compared thereby proving the validity of the model. In the proposed work the temporal evolution of the mobility degradation shows a sharp decline in emission rates below 456 s-1. We also note a sharp decline for large defects densities.展开更多
This study experimentally investigated the critical heat flux(CHF) of departure from nucleate boiling(DNB) of water flowing under near-critical pressures in a 2 m-long vertical upward rifled tube with the size of Φ35...This study experimentally investigated the critical heat flux(CHF) of departure from nucleate boiling(DNB) of water flowing under near-critical pressures in a 2 m-long vertical upward rifled tube with the size of Φ35 × 5.67 mm. Operating conditions included pressures of 18–21 MPa, mass fluxes of 475–1000 kg·m^(-2)·s^(-1), inlet subcooling temperatures of 3–5°C, and wall heat fluxes of 40–960 kW·m^(-2). Tube wall temperature distribution and heat transfer performance in different test conditions were obtained. The effects of the operating parameters on CHF were analyzed. Four heat transfer coefficient correlations were evaluated against our experimental data for further investigation of the two-phase heat transfer characteristics. A heat transfer correlation based on Martinelli number utilized in two-phase region and two empirical correlations used to predict the CHF in rifled tube at near-critical pressures were proposed. Meanwhile, experimental CHF data in rifled tube were compared with six widely used correlations and a CHF look-up table. The CHF enhancement effect in rifled tube is obvious as compared with the CHF data in smooth tube. Results show that DNB occurs at low vapor quality and subcooled region in the rifled tube at near-critical pressures. The increase in pressure leads to the early occurrence of DNB and the decrease in CHF, whereas the increase in mass flux delays the occurrence of DNB and results in the increase in CHF. DNB presents a tendency to move toward the inlet of the rifled tube. At individual operating conditions, DNB and dryout coexist at different sections of the rifled tube.展开更多
文摘AIM： To compare the efficacy of the proton-pump inhibitor, rabeprazole, with that of the H2-receptor antagonist, ranitidine, as on-demand therapy for relieving symptoms associated with non-erosive reflux disease （NEED）.METHODS： This is a single center, prospective, randomized, open-label trial of on-demand therapy with rabeprazole （group A） vs ranitidine （group B） for 4 wk. Eighty-three patients who presented to the American University of Beirut Medical Center with persistent gas- troesophageal reflux disease （GERD） symptoms and a normal upper gastrointestinal endoscopy were eligible for the study. Patients in group A （n = 44） were al-lowed a maximum rabeprazole dose of 20 mg twice daily, while those in group B （n = 39） were allowed a maximum ranitidine dose of 300 mg twice daily. Ef- ficacy was assessed by patient evaluation of global symptom relief, scores of the SF-36 quality of life （QoL） questionnaires, total number of pills used, and number of medication-free days.RESULTS： Among the 83 patients who were enrolled in the study, 76 patients （40 in the rabeprazole group and 36 in the ranitidine group） completed the 4-wk trial. Baseline characteristics were comparable between both groups. After 4 wk, there was no significant difference in the subjective global symptom relief between the rabeprazole and the ranitidine groups （71.4% vs 65.4%, respectively; P = 0.9）. There were no statistically significant differences between mean cumulative scores of the SF-36 QoL questionnaire for the two study groups （rabeprazole 22.40±27.53 vs ranitidine 17.28 ± 37.06; P = 0.582）. There was no significant difference in the mean number of pills used （rabeprazole 35.70±29.75 vs ranitidine 32.86±26.98; P = 0.66）. There was also no statistically significant difference in the mean number of medication-free days between both groups.CONCLUSION： Rabeprazole has a comparable efficacy compared to ranitidine when given on-demand for the treatment of NERD. Both medications were associated with improved quality of life.
文摘A phenomenological low-filed mobility model is developed to describe the dependence ot the carrier molgmty on me gate to source bias applied for AIGaN/GaN high electron mobility transistor. The results show excellent agreement with experimental data, when compared thereby proving the validity of the model. In the proposed work the temporal evolution of the mobility degradation shows a sharp decline in emission rates below 456 s-1. We also note a sharp decline for large defects densities.
基金financially supported by the National Key Research & Development Program of China (Grant No. 2016YFB0600201)
文摘This study experimentally investigated the critical heat flux(CHF) of departure from nucleate boiling(DNB) of water flowing under near-critical pressures in a 2 m-long vertical upward rifled tube with the size of Φ35 × 5.67 mm. Operating conditions included pressures of 18–21 MPa, mass fluxes of 475–1000 kg·m^(-2)·s^(-1), inlet subcooling temperatures of 3–5°C, and wall heat fluxes of 40–960 kW·m^(-2). Tube wall temperature distribution and heat transfer performance in different test conditions were obtained. The effects of the operating parameters on CHF were analyzed. Four heat transfer coefficient correlations were evaluated against our experimental data for further investigation of the two-phase heat transfer characteristics. A heat transfer correlation based on Martinelli number utilized in two-phase region and two empirical correlations used to predict the CHF in rifled tube at near-critical pressures were proposed. Meanwhile, experimental CHF data in rifled tube were compared with six widely used correlations and a CHF look-up table. The CHF enhancement effect in rifled tube is obvious as compared with the CHF data in smooth tube. Results show that DNB occurs at low vapor quality and subcooled region in the rifled tube at near-critical pressures. The increase in pressure leads to the early occurrence of DNB and the decrease in CHF, whereas the increase in mass flux delays the occurrence of DNB and results in the increase in CHF. DNB presents a tendency to move toward the inlet of the rifled tube. At individual operating conditions, DNB and dryout coexist at different sections of the rifled tube.
