Electrochemical CO_(2)reduction to formate is a promising approach to store renewable electricity and utilize CO_(2).Tin oxide catalysts are efficient catalysts for this process,while the mechanisms underneath,especia...Electrochemical CO_(2)reduction to formate is a promising approach to store renewable electricity and utilize CO_(2).Tin oxide catalysts are efficient catalysts for this process,while the mechanisms underneath,especially the existence and role of oxidized tin species under CO2 electroreduction conditions remain unclear.In this work,we provide strong evidence on the presence of oxidized tin species on both SnO_(2)and Sn during CO_(2)reduction via in situ surface‐enhanced Raman spectroscopy,while in different nature.Reactivity measurements show similar activity and selectivity to formate production on SnO_(2)and Sn catalysts.Combined analysis of Raman spectra and reactivity results suggests that Sn(IV)and Sn(II)oxide species are unlikely the catalytic species in CO_(2)electroreduction to formate.展开更多
Two-dimensional layered double hydroxides(LDHs)have been identified as promising electrocatalysts for the oxygen evolution reaction(OER);however,the simple and effective synthesis of high-quality LDHs remains extremel...Two-dimensional layered double hydroxides(LDHs)have been identified as promising electrocatalysts for the oxygen evolution reaction(OER);however,the simple and effective synthesis of high-quality LDHs remains extremely challenging and the active sites have not been clarified.Herein,we report a facile solution-reaction method for preparing an ultrathin(thickness<2 nm)nonprecious CoFe-based LDH.Co_(1)Fe_(0.2) LDH delivers a current density of 10 mA cm^(-2) and a high turnover frequency of 0.082 s^(-1) per total 3d metal atoms at a low overpotential of 256 mV.Its mass activity is 277.9 A g^(-1) at an overpotential of 300 mV for the OER.Kinetic studies reveal the Co site as the main active center for the OER.The doped Fe lowers the reaction barrier by accelerating the charge-transfer process.Theoretical calculations reveal that the surface Co sites adjacent to Fe atoms are the active centers for the OER and the subsurface Fe dopants excessively weaken the OH^(*)adsorption,thus increasing the energy barrier of the rate-determining step.This study can guide the rational design of high-performance CoFe-based LDHs for water splitting.展开更多
AIM： To discuss the changes of intestinal mucosal immune function in rats with experimental severe acute pancreatitis （SAP） and the regulatory effect of L-arginine. METHODS： Male adult Wistar rats were randomly di...AIM： To discuss the changes of intestinal mucosal immune function in rats with experimental severe acute pancreatitis （SAP） and the regulatory effect of L-arginine. METHODS： Male adult Wistar rats were randomly divided into pancreatitis group, sham-operation group, and L-arginine treatment group. Animals were killed at 24, 48, and 72 h after SAP models were developed and specimens were harvested. Endotoxin concentration in portal vein was determined by limulus endotoxin analysis kit. CD3＋, CD4＋, CD8＋ T lymphoo/tes in intestinal mucosal lamina propria were examined by immunohistochemistry. Secretory immunoglobulin A （SIgA） in cecum feces was examined by radioimmunoassay. RESULTS： Compared to the control group, plasma endotoxin concentration in the portal vein increased, percentage of CD3＋ and CD4＋ T lymphocyte subsets in the end of intestinal mucosal lamina propria reduced significantly, CD4＋/CD8＋ ratio decreased, and SIgA concentrations in cecum feces reduced at 24, 48, and 72 h after SAP developed. Compared to SAP group, the L-arginine treatment group had a lower level of plasma endotoxin concentration in the portal vein, a higher CD3＋ and CD4＋ T lymphocyte percentage in the end of intestinal mucosal lamina propria, an increased ratio of CD4＋/CD8＋ and a higher SIgA concentration in cecum feces. CONCLUSION： Intestinal immune suppression occurs in the early stage of SAP rats, which may be the main reason for bacterial and endotoxin translocation. L-arginine can improve the intestinal immunity and reduce bacterial and endotoxin translocation in SAP rats.展开更多
AIM： TO explore if C-reactive protein （CRP） levels might serve as a prognostic factor with respect to the clinical course of Crohn＇s disease and might be useful for classification. METHODS： In this retrospective ...AIM： TO explore if C-reactive protein （CRP） levels might serve as a prognostic factor with respect to the clinical course of Crohn＇s disease and might be useful for classification. METHODS： In this retrospective cohort study we enrolled 94 patients from the inflammatory bowel disease （IBD） database of the University Medical Centre Utrecht. CRP levels during relapse were correlated with the number of relapses per year. Severity of relapses was based on endoscopic reports and prednisone use. Furthermore, patients were categorized in a low or high CRP group based on their CRP response during relapse and demographic and clinical features were compared. RESULTS： Overall, a positive correlation between CRP levels, number of relapses, and severity of relapse was found （respectively rs = 0.31, P 〈 0.01 and rs = 0.50, P 〈 0.001）. Employing a cut-off level of 15 mg/L, the index CRP level was found to discriminate patients with respect to the number of relapses per year, as well as for severity of relapses （respectively 0.25 ± 0.16 vs 0.36 ± 0.24, P 〈 0.05 and 4.4 ± 1.2 vs 3.2 ± 1.1 on a 10-point visual analogue scale, P 〈 0.001 for the high CRP and low CRP groups respectively）. In addition, the high CRP group showed more cumulative days of prednisone use per year （107 ± 95 vs 58 ± 48, P 〈 0.05）, as well as a better response to infiiximab （93 % vs 33 %, P = 0.06）. CONCLUSION： A higher CRP level during relapse seems to be associated with a more severe clinical course of disease.展开更多
This paper presents an experimental investigation of the turbulent reacting flow in a swirl combustor with staged air injection. The air injected into the combustor is composed of the primary swirling jet and the seco...This paper presents an experimental investigation of the turbulent reacting flow in a swirl combustor with staged air injection. The air injected into the combustor is composed of the primary swirling jet and the secon-dary non-swirling jet. A three dimension-laser particle dynamic analyzer (PDA) was employed to measure the in-stantaneous gas velocity. The probability density functions (PDF) for the instantaneous gas axial and tangential ve-locities at each measuring location, as well as the radial profiles of the root mean square of fluctuating gas axial and tangential velocities and the second-order moment for the fluctuating gas axial and tangential velocities are ob-tained. The measured results delineate the turbulence properties of the swirling reacting flow under the conditions of staged combustion.展开更多
Intravenous immunoglobulin(IVIG) is biological product, which is extensively used in pediatric patients, with high adverse effects on children among different brand preparations. In the present study, we aimed to desc...Intravenous immunoglobulin(IVIG) is biological product, which is extensively used in pediatric patients, with high adverse effects on children among different brand preparations. In the present study, we aimed to describe the adverse events of pediatric patients given IVIG infusions in China. Data were collected from all patients receiving IVIG infusion at the largest children’s hospital in Ningbo of China form January 2015 to December 2017. Descriptive statistics was used. A total of 2100 patients received IVIG infusion. All the patients who experienced adverse reactions were children(0.48%), with the highest frequency of infusion among those age 1 to 3 years old(40%). Among 10 infusions with adverse reactions, the most common indication was Kawasaki disease(40%) followed by severe pneumonia(30%). Rash was the most common adverse event(80%), followed by chest pain & cough(50%) and cyanosis(40%). Adverse events were observed to occur most frequently within 30 min from onset of infusion. Most of the reactions occurred with the large dose and the indications of used for. Since the hospital changed the brand, the incidence of adverse reactions was decreased from 1.39% to 0.13%. In this study, 0.48% of pediatric patients given IVIG infusions experienced adverse events. Anaphylactoid reaction was the most common manifestation. Symptoms occurred within 30 min from onset of infusion, which were affected by the dose, the value of lgE, the indications and the different brands.展开更多
Geopolymer is produced through the polymerization of active aluminosilicate material with an alkaline activator,leading to the formation of a green,inorganic polymer binder.Geopolymer concrete(GPC)has become a promisi...Geopolymer is produced through the polymerization of active aluminosilicate material with an alkaline activator,leading to the formation of a green,inorganic polymer binder.Geopolymer concrete(GPC)has become a promising low-carbon alternative to traditional Portland cement-based concrete(OPC).GPC-bonded reinforcing bars offer a promising alternative for concrete structures,boasting excellent geopolymer binder/reinforcement bonding and superior corrosion and high-temperature resistance compared to Portland cement.However,due to differences in the production process of GPC,there are distinct engineering property variations,including bonding characteristics.This literature review provides an examination of the manufacturing procedures of GPC,encompassing source materials,mix design,curing regimes,and other factors directly influencing concrete properties.Additionally,it delves into the bond mechanism,bond tests,and corresponding results that represent the bond characteristics.The main conclusions are that GPC generally has superior mechanical properties and bond performance compared to ordinary Portland cement concrete(OPC).However,proper standardization is needed for its production and performance tests to limit the contradictory results in the lab and on site.展开更多
文摘Electrochemical CO_(2)reduction to formate is a promising approach to store renewable electricity and utilize CO_(2).Tin oxide catalysts are efficient catalysts for this process,while the mechanisms underneath,especially the existence and role of oxidized tin species under CO2 electroreduction conditions remain unclear.In this work,we provide strong evidence on the presence of oxidized tin species on both SnO_(2)and Sn during CO_(2)reduction via in situ surface‐enhanced Raman spectroscopy,while in different nature.Reactivity measurements show similar activity and selectivity to formate production on SnO_(2)and Sn catalysts.Combined analysis of Raman spectra and reactivity results suggests that Sn(IV)and Sn(II)oxide species are unlikely the catalytic species in CO_(2)electroreduction to formate.
文摘Two-dimensional layered double hydroxides(LDHs)have been identified as promising electrocatalysts for the oxygen evolution reaction(OER);however,the simple and effective synthesis of high-quality LDHs remains extremely challenging and the active sites have not been clarified.Herein,we report a facile solution-reaction method for preparing an ultrathin(thickness<2 nm)nonprecious CoFe-based LDH.Co_(1)Fe_(0.2) LDH delivers a current density of 10 mA cm^(-2) and a high turnover frequency of 0.082 s^(-1) per total 3d metal atoms at a low overpotential of 256 mV.Its mass activity is 277.9 A g^(-1) at an overpotential of 300 mV for the OER.Kinetic studies reveal the Co site as the main active center for the OER.The doped Fe lowers the reaction barrier by accelerating the charge-transfer process.Theoretical calculations reveal that the surface Co sites adjacent to Fe atoms are the active centers for the OER and the subsurface Fe dopants excessively weaken the OH^(*)adsorption,thus increasing the energy barrier of the rate-determining step.This study can guide the rational design of high-performance CoFe-based LDHs for water splitting.
文摘AIM： To discuss the changes of intestinal mucosal immune function in rats with experimental severe acute pancreatitis （SAP） and the regulatory effect of L-arginine. METHODS： Male adult Wistar rats were randomly divided into pancreatitis group, sham-operation group, and L-arginine treatment group. Animals were killed at 24, 48, and 72 h after SAP models were developed and specimens were harvested. Endotoxin concentration in portal vein was determined by limulus endotoxin analysis kit. CD3＋, CD4＋, CD8＋ T lymphoo/tes in intestinal mucosal lamina propria were examined by immunohistochemistry. Secretory immunoglobulin A （SIgA） in cecum feces was examined by radioimmunoassay. RESULTS： Compared to the control group, plasma endotoxin concentration in the portal vein increased, percentage of CD3＋ and CD4＋ T lymphocyte subsets in the end of intestinal mucosal lamina propria reduced significantly, CD4＋/CD8＋ ratio decreased, and SIgA concentrations in cecum feces reduced at 24, 48, and 72 h after SAP developed. Compared to SAP group, the L-arginine treatment group had a lower level of plasma endotoxin concentration in the portal vein, a higher CD3＋ and CD4＋ T lymphocyte percentage in the end of intestinal mucosal lamina propria, an increased ratio of CD4＋/CD8＋ and a higher SIgA concentration in cecum feces. CONCLUSION： Intestinal immune suppression occurs in the early stage of SAP rats, which may be the main reason for bacterial and endotoxin translocation. L-arginine can improve the intestinal immunity and reduce bacterial and endotoxin translocation in SAP rats.
文摘AIM： TO explore if C-reactive protein （CRP） levels might serve as a prognostic factor with respect to the clinical course of Crohn＇s disease and might be useful for classification. METHODS： In this retrospective cohort study we enrolled 94 patients from the inflammatory bowel disease （IBD） database of the University Medical Centre Utrecht. CRP levels during relapse were correlated with the number of relapses per year. Severity of relapses was based on endoscopic reports and prednisone use. Furthermore, patients were categorized in a low or high CRP group based on their CRP response during relapse and demographic and clinical features were compared. RESULTS： Overall, a positive correlation between CRP levels, number of relapses, and severity of relapse was found （respectively rs = 0.31, P 〈 0.01 and rs = 0.50, P 〈 0.001）. Employing a cut-off level of 15 mg/L, the index CRP level was found to discriminate patients with respect to the number of relapses per year, as well as for severity of relapses （respectively 0.25 ± 0.16 vs 0.36 ± 0.24, P 〈 0.05 and 4.4 ± 1.2 vs 3.2 ± 1.1 on a 10-point visual analogue scale, P 〈 0.001 for the high CRP and low CRP groups respectively）. In addition, the high CRP group showed more cumulative days of prednisone use per year （107 ± 95 vs 58 ± 48, P 〈 0.05）, as well as a better response to infiiximab （93 % vs 33 %, P = 0.06）. CONCLUSION： A higher CRP level during relapse seems to be associated with a more severe clinical course of disease.
基金Supported jointly by the National Natural Science Foundation of China (No.59806006) and the Laboratory Open Fund ofTsinghua University.
文摘This paper presents an experimental investigation of the turbulent reacting flow in a swirl combustor with staged air injection. The air injected into the combustor is composed of the primary swirling jet and the secon-dary non-swirling jet. A three dimension-laser particle dynamic analyzer (PDA) was employed to measure the in-stantaneous gas velocity. The probability density functions (PDF) for the instantaneous gas axial and tangential ve-locities at each measuring location, as well as the radial profiles of the root mean square of fluctuating gas axial and tangential velocities and the second-order moment for the fluctuating gas axial and tangential velocities are ob-tained. The measured results delineate the turbulence properties of the swirling reacting flow under the conditions of staged combustion.
基金Wenzhou Science and Technology Program(Grant No.Y20160012)
文摘Intravenous immunoglobulin(IVIG) is biological product, which is extensively used in pediatric patients, with high adverse effects on children among different brand preparations. In the present study, we aimed to describe the adverse events of pediatric patients given IVIG infusions in China. Data were collected from all patients receiving IVIG infusion at the largest children’s hospital in Ningbo of China form January 2015 to December 2017. Descriptive statistics was used. A total of 2100 patients received IVIG infusion. All the patients who experienced adverse reactions were children(0.48%), with the highest frequency of infusion among those age 1 to 3 years old(40%). Among 10 infusions with adverse reactions, the most common indication was Kawasaki disease(40%) followed by severe pneumonia(30%). Rash was the most common adverse event(80%), followed by chest pain & cough(50%) and cyanosis(40%). Adverse events were observed to occur most frequently within 30 min from onset of infusion. Most of the reactions occurred with the large dose and the indications of used for. Since the hospital changed the brand, the incidence of adverse reactions was decreased from 1.39% to 0.13%. In this study, 0.48% of pediatric patients given IVIG infusions experienced adverse events. Anaphylactoid reaction was the most common manifestation. Symptoms occurred within 30 min from onset of infusion, which were affected by the dose, the value of lgE, the indications and the different brands.
基金supported by the ongoing projects provided by the National Key Research and Development Program(2021YFB2600704)the National Natural Science Foundation of China(52108223,U22A20244)+3 种基金the Outstanding Youth Fund of Shandong Province(ZR2021JQ17)the Natural Science Foundation of Shandong Province(ZR2020QE249)the 111 Project(D16006)the First-Class Discipline Project funded by the Education Department of Shandong Province are gratefully acknowledged.
文摘Geopolymer is produced through the polymerization of active aluminosilicate material with an alkaline activator,leading to the formation of a green,inorganic polymer binder.Geopolymer concrete(GPC)has become a promising low-carbon alternative to traditional Portland cement-based concrete(OPC).GPC-bonded reinforcing bars offer a promising alternative for concrete structures,boasting excellent geopolymer binder/reinforcement bonding and superior corrosion and high-temperature resistance compared to Portland cement.However,due to differences in the production process of GPC,there are distinct engineering property variations,including bonding characteristics.This literature review provides an examination of the manufacturing procedures of GPC,encompassing source materials,mix design,curing regimes,and other factors directly influencing concrete properties.Additionally,it delves into the bond mechanism,bond tests,and corresponding results that represent the bond characteristics.The main conclusions are that GPC generally has superior mechanical properties and bond performance compared to ordinary Portland cement concrete(OPC).However,proper standardization is needed for its production and performance tests to limit the contradictory results in the lab and on site.
