BACKGROUND Proton pump inhibitors(PPIs)are widely used,including among cancer patients,to manage gastroesophageal reflux and other gastric acid-related disorders.Recent evidence suggests associations between long-term...BACKGROUND Proton pump inhibitors(PPIs)are widely used,including among cancer patients,to manage gastroesophageal reflux and other gastric acid-related disorders.Recent evidence suggests associations between long-term PPI use and higher risks for various adverse health outcomes,including greater mortality.AIM To investigate the association between PPI use and all-cause mortality among cancer patients by a comprehensive analysis after adjustment for various confounders and a robust methodological approach to minimize bias.METHODS This retrospective cohort study used data from the TriNetX research network,with electronic health records from multiple healthcare organizations.The study employed a new-user,active comparator design,which compared newly treated PPI users with non-users and newly treated histamine2 receptor antagonists(H2RA)users among adult cancer patients.Newly prescribed PPIs(esomeprazole,lansoprazole,omeprazole,pantoprazole,or rabeprazole)users were compared to non-users or newly prescribed H2RAs(cimetidine,famotidine,nizatidine,or ranitidine)users.The primary outcome was all-cause mortality.Each patient in the main group was matched to a patient in the control group using 1:1 propensity score matching to reduce confounding effects.Multivariable Cox regression models were used to estimate hazard ratios(HRs)and 95% confidence interval(CI).RESULTS During the follow-up period(median 5.4±1.8 years for PPI users and 6.5±1.0 years for non-users),PPI users demonstrated a higher all-cause mortality rate than non-users after 1 year,2 years,and at the end of follow up(HRs:2.34-2.72).Compared with H2RA users,PPI users demonstrated a higher rate of all-cause mortality HR:1.51(95%CI:1.41-1.69).Similar results were observed across sensitivity analyses by excluding deaths from the first 9 months and 1-year post-exposure,confirming the robustness of these findings.In a sensitivity analysis,we analyzed all-cause mortality outcomes between former PPI users and individuals who have never used PPIs,providing insights into the long-term effects of past PPI use.In addition,at 1-year follow-up,the analysis revealed a significant difference in mortality rates between former PPI users and non-users(HR:1.84;95%CI:1.82-1.96).CONCLUSION PPI use among cancer patients was associated with a higher risk of all-cause mortality compared to non-users or H2RA users.These findings emphasize the need for cautious use of PPIs in cancer patients and suggest that alternative treatments should be considered when clinically feasible.However,further studies are needed to corroborate our findings,given the significant adverse outcomes in cancer patients.展开更多
Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in viv...Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in vivo models to study the role of Na^(+)/K^(+)-ATPase in these diseases,we modified the Drosophila gene homolog,Atpα,to mimic the human ATP1A1 gene mutations that cause CMT2.Mutations located within the helical linker region of human ATP1A1(I592T,A597T,P600T,and D601F)were simultaneously introduced into endogenous Drosophila Atpαby CRISPR/Cas9-mediated genome editing,generating the Atpα^(TTTF)model.In addition,the same strategy was used to generate the corresponding single point mutations in flies(Atpα^(I571T),Atpα^(A576T),Atpα^(P579T),and Atpα^(D580F)).Moreover,a deletion mutation(Atpα^(mut))that causes premature termination of translation was generated as a positive control.Of these alleles,we found two that could be maintained as homozygotes(Atpα^(I571T)and Atpα^(P579T)).Three alleles(Atpα^(A576T),Atpα^(P579)and Atpα^(D580F))can form heterozygotes with the Atpαmut allele.We found that the Atpαallele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila.Flies heterozygous for Atpα^(TTTF)mutations have motor performance defects,a reduced lifespan,seizures,and an abnormal neuronal morphology.These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump.展开更多
We report the preparation of D2 molecules in v=2 level in molecular beam condition. A single longitudinal mode laser system was used for excitation of D2 from （v=0, j=0） to （v=2, j=0） with the scheme of stimulated...We report the preparation of D2 molecules in v=2 level in molecular beam condition. A single longitudinal mode laser system was used for excitation of D2 from （v=0, j=0） to （v=2, j=0） with the scheme of stimulated Raman pumping. An excitation efficiency of 25.2% has been achieved, which was determined by the scheme of resonance-enhanced multiphoton ion- ization. Dependence of relative excitation efficiency on laser energy has been measured. We found that the increasing rate of excitation efficiency became slower as pulse energy of Stokes laser increase, while the excitation efficiency still increases approximately linearly with pump pulse energies up to 60 mJ. The spectral line shapes of Raman transition was also measured at different laser energies and considerable dynamical Stark effect was observed. A single peak was found on the three dimension surface of relative excitation efficiency, indicating the process occurred in the present study is a process of stimulated Raman pumping instead of stimulated adiabatic Raman passage.展开更多
AIM: To compare the therapeutic effects of proton pump inhibitors vs H2 receptor antagonists for upper gastrointestinal bleeding in patients after successful endoscopy.METHODS: We searched the Cochrane library, MEDLIN...AIM: To compare the therapeutic effects of proton pump inhibitors vs H2 receptor antagonists for upper gastrointestinal bleeding in patients after successful endoscopy.METHODS: We searched the Cochrane library, MEDLINE, EMBASE and Pub Med for randomized controlled trials until July 2014 for this study. The risk of bias was evaluated by the Cochrane Collaboration's tool and all of the studies had acceptable quality. The main outcomes included mortality, re-bleeding, received surgery rate, blood transfusion units and hospital stay time. These outcomes were estimated using odds ratios(OR) and mean difference with 95% confidence interval(CI). Rev Man 5.3.3 software and Stata 12.0 software were used for data analyses. RESULTS: Ten randomized controlled trials involving 1283 patients were included in this review; 678 subjects were in the proton pump inhibitors(PPI) group and the remaining 605 subjects were in the H2 receptor antagonists(H2RA) group. The meta-analysis results revealed that after successful endoscopic therapy, compared with H2 RA, PPI therapy had statistically significantly decreased the recurrent bleeding rate(OR = 0.36; 95%CI: 0.25-0.51) and receiving surgery rate(OR = 0.29; 95%CI: 0.09-0.96). There were no statistically significant differences in mortality(OR = 0.46; 95%CI: 0.17-1.23). However, significant heterogeneity was present in both the numbers of patients requiring blood transfusion after treatment [weighted mean difference(WMD),-0.70 unit; 95%CI:-1.64- 0.25] and the time that patients remained hospitalized [WMD,-0.77 d; 95%CI:-1.87- 0.34]. The Begg's test(P = 0.283) and Egger's test(P = 0.339) demonstrated that there was no publication bias in our meta-analysis.CONCLUSION: In patients with upper gastrointestinal bleeding after successful endoscopic therapy, compared with H2 RA, PPI may be a more effective therapy.展开更多
This study investigates tribological performance of MoS2 coating on slipper pair in axial piston pump.Firstly,the MoS2 coating on the surface of slipper pair was prepared by atmospheric plasma spraying treatment techn...This study investigates tribological performance of MoS2 coating on slipper pair in axial piston pump.Firstly,the MoS2 coating on the surface of slipper pair was prepared by atmospheric plasma spraying treatment technology.Secondly,the tribological characteristics of slipper pair under various working conditions were evaluated on ring-on-block tester in oil lubrication.The original and worn surfaces of the specimens were analyzed with scanning electron microscope and energy dispersive spectrometer,and then the wear morphologies of the MoS2 coatings were imaged by X-ray photoelectron spectroscopy.The experimental results showed that the friction coefficients of Cu-based materials with MoS2 coating decreased by about 0.05 at 800 N.Especially,when the external load was set to 800 N,the wear rate of the ZY331608 decreased by about 16.4%after the substrates were treated by the MoS2 coating,which exhibited excellent anti-friction and wear resistance.The formation of the MoS2 lubricating film could be classified into four stages,including the initial friction stage,anchoring stage of MoS2 on friction surface,covering stage of the sliding surface by MoS2 and the formation stage of MoS2 film.The dominating wear mechanisms of Cu-based materials with MoS2 coating were adhesive wear and abrasive wear accompanied with oxidative wear.展开更多
AIM: To compare the antisecretory activity and plasma drug concentrations of a single oral dose of 10 mg lafutidine, a novel H2 receptor antagonist, with those of the proton pump inhibitor lansoprazole (LPZ) 30 mg. ME...AIM: To compare the antisecretory activity and plasma drug concentrations of a single oral dose of 10 mg lafutidine, a novel H2 receptor antagonist, with those of the proton pump inhibitor lansoprazole (LPZ) 30 mg. METHODS: Ten volunteers without H pylori infection participated in this crossover study comparing lafutidine 10 mg with LPZ 30 mg. Intragastric pH was monitored for 6 h in all participants, and blood samples were collected from four randomly selected individuals after single-dose administration of each drug. RESULTS: The median intragastric pH was significantly higher in individuals who received lafutidine 10 mg than in those who received LPZ 30 mg 2, 3, 4, 5, and 6 h after administration. Maximal plasma drug concentration was reached more promptly with lafutidine 10 mg than with LPZ 30 mg. CONCLUSION: In H pylori-negative individuals, gastric acid secretion is more markedly inhibited by lafutidinethan by LPZ.展开更多
（Bi2O3）0.73（Y2O3）0.27 fine powders prepared by wet chemical precipitation method were cold isostatically pressed to form solid electrolyte tubes, and sintered at 900 ℃ for 10 h in the air. Their pumping oxygen ch...（Bi2O3）0.73（Y2O3）0.27 fine powders prepared by wet chemical precipitation method were cold isostatically pressed to form solid electrolyte tubes, and sintered at 900 ℃ for 10 h in the air. Their pumping oxygen characteristics in non-dehydrated Ar gas were investigated, where a ZrO2 （Y2O3 stabilized） oxygen sensor was used to measure the oxygen partial pressure Po2. The results showed that the Po2 value reached magnitudes of 1×10^-2-1×10^-10 Pa at the applied pumping oxygen voltage of 0.5 V, 1×10^-37-1×10^-27 Pa at 1.0 V and 1×10^-53-1×10^47 Pa at 2.0 V within the temperature range from 550 to 650 ℃. Moreover, no cracks were found in the tested solid electrolyte tubes. Thus, the Bi2O3-Y2O3 system might be used in solid electrolyte oxygen pump for purifying gases.展开更多
AIM: To systematically evaluate the efficacy of H2-receptor antagonists (H2RAs) and proton pump inhibitors in healing erosive esophagitis (EE).METHODS: A meta-analysis was performed. A literature search was conducted ...AIM: To systematically evaluate the efficacy of H2-receptor antagonists (H2RAs) and proton pump inhibitors in healing erosive esophagitis (EE).METHODS: A meta-analysis was performed. A literature search was conducted in PubMed, Medline, Embase, and Cochrane databases to include randomized controlled head-to-head comparative trials evaluating the efficacy of H2RAs or proton pump inhibitors in healing EE. Relative risk (RR) and 95% confidence interval (CI) were calculated under a random-effects model.RESULTS: RRs of cumulative healing rates for each comparison at 8 wk were: high dose vs standard dose H2RAs,1.17 (95%CI, 1.02-1.33); standard dose proton pump inhibitors vsstandard dose H2RAs, 1.59 (95%CI, 1.44-1.75);standard dose other proton pump inhibitors vs standard dose omeprazole, 1.06 (95%CI, 0.98-1.06). Proton pump inhibitors produced consistently greater healing rates than H2RAs of all doses across all grades of esophagitis, including patients refractory to H2RAs. Healing rates achieved with standard dose omeprazole were similar to those with other proton pump inhibitors in all grades of esophagitis.CONCLUSION: H2RAS are less effective for treating patients with erosive esophagitis, especially in those with severe forms of esophagitis. Standard dose proton pump inhibitors are significantly more effective than H2RAs in healing esophagitis of all grades. Proton pump inhibitors given at the recommended dose are equally effective for healing esophagitis.展开更多
Here, we propose a chemical heat pump chiller with a SrBr<sub>2</sub> hydration reaction system for utilization of waste heat. The SrBr<sub>2</sub> hydration reaction could recover waste heat i...Here, we propose a chemical heat pump chiller with a SrBr<sub>2</sub> hydration reaction system for utilization of waste heat. The SrBr<sub>2</sub> hydration reaction could recover waste heat in low temperatures ranging from 373 K to 353 K, and the system showed good potential in terms of the high cooling thermal-storage density. Previous studies have given little information on the reaction characteristics of the SrBr<sub>2</sub> hydration reaction. In this paper, we developed a measuring method for the hydration reaction equilibrium and reaction rate based on the volumetric method. We analyzed the hydration reaction rate with an unreacted-core shell model. In the experiments, the SrBr<sub>2</sub> equilibrium temperature observed was equal to the theoretical equilibrium temperature obtained from thermodynamic databases. In addition, the hysteresis gap between the hydration and dehydration values was 2.0 K. Thus, the hysteresis effect was negligible for the chemical heat pump cooling operation. The reaction fraction of the SrBr<sub>2</sub> hydration reached 0.7 within 20 s. By analyzing the hydration reaction rate with the unreacted-core shell model, the activation energy value was calculated to be56.6 kJ/mol. The calculation results showed good agreement with those of the experiment as the reaction fraction reached 0.7.展开更多
The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit ...The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit is about 1 kW, and the work refrigerant is R22/R407C/R410A/CO2. The MATLAB/SIMULINK software was employed to build the simulation model. The thermodynamic simulation model is significant for the optimization of parameters of the unit, such as condensation and evaporation temperature and mass flow of the sanitary hot water and size of hot water storage tank. The COP of the CCP of R410A system is about 3% - 5% higher than the CCP of the R22 system, while CCP of the R407C system is a little lower than the CCP of R22 system. And the CCP of CO2 trans-critical system has advantage in the hot supply mode. The simulation method provided a theoretical reference for developing the production of CCP with substitute refrigerant R407C/R410A/CO2.展开更多
文摘BACKGROUND Proton pump inhibitors(PPIs)are widely used,including among cancer patients,to manage gastroesophageal reflux and other gastric acid-related disorders.Recent evidence suggests associations between long-term PPI use and higher risks for various adverse health outcomes,including greater mortality.AIM To investigate the association between PPI use and all-cause mortality among cancer patients by a comprehensive analysis after adjustment for various confounders and a robust methodological approach to minimize bias.METHODS This retrospective cohort study used data from the TriNetX research network,with electronic health records from multiple healthcare organizations.The study employed a new-user,active comparator design,which compared newly treated PPI users with non-users and newly treated histamine2 receptor antagonists(H2RA)users among adult cancer patients.Newly prescribed PPIs(esomeprazole,lansoprazole,omeprazole,pantoprazole,or rabeprazole)users were compared to non-users or newly prescribed H2RAs(cimetidine,famotidine,nizatidine,or ranitidine)users.The primary outcome was all-cause mortality.Each patient in the main group was matched to a patient in the control group using 1:1 propensity score matching to reduce confounding effects.Multivariable Cox regression models were used to estimate hazard ratios(HRs)and 95% confidence interval(CI).RESULTS During the follow-up period(median 5.4±1.8 years for PPI users and 6.5±1.0 years for non-users),PPI users demonstrated a higher all-cause mortality rate than non-users after 1 year,2 years,and at the end of follow up(HRs:2.34-2.72).Compared with H2RA users,PPI users demonstrated a higher rate of all-cause mortality HR:1.51(95%CI:1.41-1.69).Similar results were observed across sensitivity analyses by excluding deaths from the first 9 months and 1-year post-exposure,confirming the robustness of these findings.In a sensitivity analysis,we analyzed all-cause mortality outcomes between former PPI users and individuals who have never used PPIs,providing insights into the long-term effects of past PPI use.In addition,at 1-year follow-up,the analysis revealed a significant difference in mortality rates between former PPI users and non-users(HR:1.84;95%CI:1.82-1.96).CONCLUSION PPI use among cancer patients was associated with a higher risk of all-cause mortality compared to non-users or H2RA users.These findings emphasize the need for cautious use of PPIs in cancer patients and suggest that alternative treatments should be considered when clinically feasible.However,further studies are needed to corroborate our findings,given the significant adverse outcomes in cancer patients.
基金supported by the Natural Science Foundation of Fujian Province,No.2020J02027the National Natural Science Foundation of China,No.31970461the Foundation of NHC Key Laboratory of Technical Evaluation of Fertility Regulation for Non-human Primate,Fujian Maternity and Child Health Hospital,No.2022-NHP-05(all to WC).
文摘Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in vivo models to study the role of Na^(+)/K^(+)-ATPase in these diseases,we modified the Drosophila gene homolog,Atpα,to mimic the human ATP1A1 gene mutations that cause CMT2.Mutations located within the helical linker region of human ATP1A1(I592T,A597T,P600T,and D601F)were simultaneously introduced into endogenous Drosophila Atpαby CRISPR/Cas9-mediated genome editing,generating the Atpα^(TTTF)model.In addition,the same strategy was used to generate the corresponding single point mutations in flies(Atpα^(I571T),Atpα^(A576T),Atpα^(P579T),and Atpα^(D580F)).Moreover,a deletion mutation(Atpα^(mut))that causes premature termination of translation was generated as a positive control.Of these alleles,we found two that could be maintained as homozygotes(Atpα^(I571T)and Atpα^(P579T)).Three alleles(Atpα^(A576T),Atpα^(P579)and Atpα^(D580F))can form heterozygotes with the Atpαmut allele.We found that the Atpαallele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila.Flies heterozygous for Atpα^(TTTF)mutations have motor performance defects,a reduced lifespan,seizures,and an abnormal neuronal morphology.These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump.
文摘We report the preparation of D2 molecules in v=2 level in molecular beam condition. A single longitudinal mode laser system was used for excitation of D2 from （v=0, j=0） to （v=2, j=0） with the scheme of stimulated Raman pumping. An excitation efficiency of 25.2% has been achieved, which was determined by the scheme of resonance-enhanced multiphoton ion- ization. Dependence of relative excitation efficiency on laser energy has been measured. We found that the increasing rate of excitation efficiency became slower as pulse energy of Stokes laser increase, while the excitation efficiency still increases approximately linearly with pump pulse energies up to 60 mJ. The spectral line shapes of Raman transition was also measured at different laser energies and considerable dynamical Stark effect was observed. A single peak was found on the three dimension surface of relative excitation efficiency, indicating the process occurred in the present study is a process of stimulated Raman pumping instead of stimulated adiabatic Raman passage.
基金Supported by National Natural Science Funds of China,No.81102784/H2803the key project in scientific research from ministry of education,No.212032Liaoning Innovative Research Team in University,No.LT2013022
文摘AIM: To compare the therapeutic effects of proton pump inhibitors vs H2 receptor antagonists for upper gastrointestinal bleeding in patients after successful endoscopy.METHODS: We searched the Cochrane library, MEDLINE, EMBASE and Pub Med for randomized controlled trials until July 2014 for this study. The risk of bias was evaluated by the Cochrane Collaboration's tool and all of the studies had acceptable quality. The main outcomes included mortality, re-bleeding, received surgery rate, blood transfusion units and hospital stay time. These outcomes were estimated using odds ratios(OR) and mean difference with 95% confidence interval(CI). Rev Man 5.3.3 software and Stata 12.0 software were used for data analyses. RESULTS: Ten randomized controlled trials involving 1283 patients were included in this review; 678 subjects were in the proton pump inhibitors(PPI) group and the remaining 605 subjects were in the H2 receptor antagonists(H2RA) group. The meta-analysis results revealed that after successful endoscopic therapy, compared with H2 RA, PPI therapy had statistically significantly decreased the recurrent bleeding rate(OR = 0.36; 95%CI: 0.25-0.51) and receiving surgery rate(OR = 0.29; 95%CI: 0.09-0.96). There were no statistically significant differences in mortality(OR = 0.46; 95%CI: 0.17-1.23). However, significant heterogeneity was present in both the numbers of patients requiring blood transfusion after treatment [weighted mean difference(WMD),-0.70 unit; 95%CI:-1.64- 0.25] and the time that patients remained hospitalized [WMD,-0.77 d; 95%CI:-1.87- 0.34]. The Begg's test(P = 0.283) and Egger's test(P = 0.339) demonstrated that there was no publication bias in our meta-analysis.CONCLUSION: In patients with upper gastrointestinal bleeding after successful endoscopic therapy, compared with H2 RA, PPI may be a more effective therapy.
基金Project(51805376)supported by the National Natural Science Foundation of ChinaProject(LQ17E050003)supported by the Zhejiang Provincial Natural Science Foundation of China+1 种基金Project(GZKF-201719)supported by the Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems,ChinaProject(G20180019)supported by the Basic Scientific Research Projects Foundation of Wenzhou,China。
文摘This study investigates tribological performance of MoS2 coating on slipper pair in axial piston pump.Firstly,the MoS2 coating on the surface of slipper pair was prepared by atmospheric plasma spraying treatment technology.Secondly,the tribological characteristics of slipper pair under various working conditions were evaluated on ring-on-block tester in oil lubrication.The original and worn surfaces of the specimens were analyzed with scanning electron microscope and energy dispersive spectrometer,and then the wear morphologies of the MoS2 coatings were imaged by X-ray photoelectron spectroscopy.The experimental results showed that the friction coefficients of Cu-based materials with MoS2 coating decreased by about 0.05 at 800 N.Especially,when the external load was set to 800 N,the wear rate of the ZY331608 decreased by about 16.4%after the substrates were treated by the MoS2 coating,which exhibited excellent anti-friction and wear resistance.The formation of the MoS2 lubricating film could be classified into four stages,including the initial friction stage,anchoring stage of MoS2 on friction surface,covering stage of the sliding surface by MoS2 and the formation stage of MoS2 film.The dominating wear mechanisms of Cu-based materials with MoS2 coating were adhesive wear and abrasive wear accompanied with oxidative wear.
文摘AIM: To compare the antisecretory activity and plasma drug concentrations of a single oral dose of 10 mg lafutidine, a novel H2 receptor antagonist, with those of the proton pump inhibitor lansoprazole (LPZ) 30 mg. METHODS: Ten volunteers without H pylori infection participated in this crossover study comparing lafutidine 10 mg with LPZ 30 mg. Intragastric pH was monitored for 6 h in all participants, and blood samples were collected from four randomly selected individuals after single-dose administration of each drug. RESULTS: The median intragastric pH was significantly higher in individuals who received lafutidine 10 mg than in those who received LPZ 30 mg 2, 3, 4, 5, and 6 h after administration. Maximal plasma drug concentration was reached more promptly with lafutidine 10 mg than with LPZ 30 mg. CONCLUSION: In H pylori-negative individuals, gastric acid secretion is more markedly inhibited by lafutidinethan by LPZ.
基金the National Natural Science Foundation of China (50774018)
文摘（Bi2O3）0.73（Y2O3）0.27 fine powders prepared by wet chemical precipitation method were cold isostatically pressed to form solid electrolyte tubes, and sintered at 900 ℃ for 10 h in the air. Their pumping oxygen characteristics in non-dehydrated Ar gas were investigated, where a ZrO2 （Y2O3 stabilized） oxygen sensor was used to measure the oxygen partial pressure Po2. The results showed that the Po2 value reached magnitudes of 1×10^-2-1×10^-10 Pa at the applied pumping oxygen voltage of 0.5 V, 1×10^-37-1×10^-27 Pa at 1.0 V and 1×10^-53-1×10^47 Pa at 2.0 V within the temperature range from 550 to 650 ℃. Moreover, no cracks were found in the tested solid electrolyte tubes. Thus, the Bi2O3-Y2O3 system might be used in solid electrolyte oxygen pump for purifying gases.
基金Supported by the Gastroenterological Research Fund, University of Hong Kong, Hong Kong, China
文摘AIM: To systematically evaluate the efficacy of H2-receptor antagonists (H2RAs) and proton pump inhibitors in healing erosive esophagitis (EE).METHODS: A meta-analysis was performed. A literature search was conducted in PubMed, Medline, Embase, and Cochrane databases to include randomized controlled head-to-head comparative trials evaluating the efficacy of H2RAs or proton pump inhibitors in healing EE. Relative risk (RR) and 95% confidence interval (CI) were calculated under a random-effects model.RESULTS: RRs of cumulative healing rates for each comparison at 8 wk were: high dose vs standard dose H2RAs,1.17 (95%CI, 1.02-1.33); standard dose proton pump inhibitors vsstandard dose H2RAs, 1.59 (95%CI, 1.44-1.75);standard dose other proton pump inhibitors vs standard dose omeprazole, 1.06 (95%CI, 0.98-1.06). Proton pump inhibitors produced consistently greater healing rates than H2RAs of all doses across all grades of esophagitis, including patients refractory to H2RAs. Healing rates achieved with standard dose omeprazole were similar to those with other proton pump inhibitors in all grades of esophagitis.CONCLUSION: H2RAS are less effective for treating patients with erosive esophagitis, especially in those with severe forms of esophagitis. Standard dose proton pump inhibitors are significantly more effective than H2RAs in healing esophagitis of all grades. Proton pump inhibitors given at the recommended dose are equally effective for healing esophagitis.
文摘Here, we propose a chemical heat pump chiller with a SrBr<sub>2</sub> hydration reaction system for utilization of waste heat. The SrBr<sub>2</sub> hydration reaction could recover waste heat in low temperatures ranging from 373 K to 353 K, and the system showed good potential in terms of the high cooling thermal-storage density. Previous studies have given little information on the reaction characteristics of the SrBr<sub>2</sub> hydration reaction. In this paper, we developed a measuring method for the hydration reaction equilibrium and reaction rate based on the volumetric method. We analyzed the hydration reaction rate with an unreacted-core shell model. In the experiments, the SrBr<sub>2</sub> equilibrium temperature observed was equal to the theoretical equilibrium temperature obtained from thermodynamic databases. In addition, the hysteresis gap between the hydration and dehydration values was 2.0 K. Thus, the hysteresis effect was negligible for the chemical heat pump cooling operation. The reaction fraction of the SrBr<sub>2</sub> hydration reached 0.7 within 20 s. By analyzing the hydration reaction rate with the unreacted-core shell model, the activation energy value was calculated to be56.6 kJ/mol. The calculation results showed good agreement with those of the experiment as the reaction fraction reached 0.7.
文摘The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit is about 1 kW, and the work refrigerant is R22/R407C/R410A/CO2. The MATLAB/SIMULINK software was employed to build the simulation model. The thermodynamic simulation model is significant for the optimization of parameters of the unit, such as condensation and evaporation temperature and mass flow of the sanitary hot water and size of hot water storage tank. The COP of the CCP of R410A system is about 3% - 5% higher than the CCP of the R22 system, while CCP of the R407C system is a little lower than the CCP of R22 system. And the CCP of CO2 trans-critical system has advantage in the hot supply mode. The simulation method provided a theoretical reference for developing the production of CCP with substitute refrigerant R407C/R410A/CO2.
