BACKGROUND:Hypothermia is associated with poor outcome in trauma patients;however,hemorrhagic shock(HS)model with anesthetized swine was different from that of clinical reality.To identify the effects of environmental...BACKGROUND:Hypothermia is associated with poor outcome in trauma patients;however,hemorrhagic shock(HS)model with anesthetized swine was different from that of clinical reality.To identify the effects of environmental hypothermia on HS,we investigated hemodynamics and oxygen dynamics in an unanesthetized swine model of HS under simulating hypothermia environment.METHODS:Totally 16 Bama pigs were randomly divided into ambient temperature group(group A)and low temperature group(group B),8 pigs in each group.Venous blood(30 mL/kg)was continuously withdrawn for more than 15 minutes in conscious swine to establish a hemorrhagic shock model.Pulmonary arterial temperature(Tp),heart rate(HR),mean arterial pressure(MAP),pulmonary arterial pressure(PAP),pulmonary arterial wedge pressure(PAWP),central venous pressure(CVP),cardiac output(CO),hemoglobin(Hb),saturation of mixed venous blood(SvO_2)and blood gas analysis were recorded at the baseline and different hemorrhagic shock time(HST).The whole body oxygen delivery indices,DO_2l and VO_2l,and the O_2 extraction ratio(O_2ER)were calculated.RESULTS:Core body temperature in group A decreased slightly after the hemorrhagic shock model was established,and environmental hypothermia decreased in core body temperature.The mortality rate was significantly higher in group B(50%)than in group A(0%).DO_2l and VO_2l decreased significantly after hemorrhage.No difference was found in hemodynamics,DO_2l and VO_2l between group A and group B,but the difference in pH,lactic acid and O_2ER was significant between the two groups.CONCLUSION:Environmental hypothermia aggravated the disorder of oxygen metabolism after hemorrhagic shock,which was associated with poor prognosis.展开更多
To study monitoring hemodynamics and oxygen dynamics of adult respiratory distress syndrome (ARDS) secondary to high altitude pulmonary edema (HAPE),we performed clinic and laboratory studies in 8 patients who prelimi...To study monitoring hemodynamics and oxygen dynamics of adult respiratory distress syndrome (ARDS) secondary to high altitude pulmonary edema (HAPE),we performed clinic and laboratory studies in 8 patients who preliminarily developed high altitude cerebral edema (HACE) and then ARDS occurred at an altitude of 4 500 m. After an initial emergency treatment on high mountains,all the patients were rapidly transported to a hospital at a lower altitude of 2 808 m. The right cardiac catheterizations were carried out within 5 h after hospitalized. The monitoring hemodynamics and oxygen dynamics were studied via a thermodilution Swan-Gaze catheter. The results showed that before treatments at the beginning of monitoring,there presented a significant pulmonary artery hypertension with a decreased cardiac function,and a lower oxygen metabolism in all the 8 patients. However,after some effective treatments,including mechanical ventilation and using dexamethasone,furosemide,etc,four days later the result of a repeated monitoring showed that their pulmonary artery pressure had been decreased with an improved cardiac function with all the oxygen metabolic indexes increased significantly. Our studies suggested that performing monitoring hemodynamics in patients with ARDS secondary to HAPE will define the clinical therapeutic measures which will benefit the outcome.展开更多
Increasing evidence demonstrates that mammals have different reactions to hypoxia with varied oxygen dynamic patterns.It takes~24 h for tri-gas incubator to achieve steady cell hypoxia,which fails to recapitulate ultr...Increasing evidence demonstrates that mammals have different reactions to hypoxia with varied oxygen dynamic patterns.It takes~24 h for tri-gas incubator to achieve steady cell hypoxia,which fails to recapitulate ultrafast oxygen dynamics of intestinal ischemia/reperfusion(IR)injury.Inspired from the structure of native intestinal villi,we engineered an intestinal organoid chip embedded with engineered artificial microvessels based on coaxial microfluidic technology by using pH-responsive ZIF-8/sodium alginate scaffold.The chip was featured on:(i)eight times the oxygen exchange efficiency compared with the conventional device,tri-gas incubator,(ii)implantation of intestinal organoid reproducing all types of intestinal epithelial cells,and(iii)bio-responsiveness to hypoxia and reoxygenation(HR)by presenting metabolism disorder,inflammatory reaction,and cell apoptosis.Strikingly,it was found for the first time that Olfactomedin 4(Olfm4)was the most significantly downregulated gene under a rapid HR condition by sequencing the RNA from the organoids.Mechanistically,OLFM4 played protective functions on HR-induced cell inflammation and tissue damage by inhibiting the NF-kappa B signaling activation,thus it could be used as a therapeutic target.Altogether,this study overcomes the issue of mismatched oxygen dynamics between in vitro and in vivo,and sets an example of next-generation multisysteminteractive organoid chip for finding precise therapeutic targets of IR injury.展开更多
Surface oxygen vacancies(OVs) with abundant localized electrons on bismuth-oxygen based photocatalysts are proved to have the ability to capture and activate CO_(2).However,the surface OVs are easily filled with oxyge...Surface oxygen vacancies(OVs) with abundant localized electrons on bismuth-oxygen based photocatalysts are proved to have the ability to capture and activate CO_(2).However,the surface OVs are easily filled with oxygen-containing species and destroyed,losing their effects as active sites and hindering the subsequent CO_(2)photoreduction.For realistic and sustainable CO_(2)photoreduction,constructing sustainable and stable surface OVs as active sites on photocatalysts is essential.This work shows the synthesis of interlayer stretched Bi_(2)O_(2)CO_(3) ultrathin nanosheets with tensile stress,which are beneficial to continuously generating light-induced dynamic OVs.With sufficient active sites,excellent,stable,and selective photoreduction of CO_(2)to CO under simulated solar light is achieved.The light-induced OVs can reduce the energy barrier of rate-determining step,resulting in the 100% product selectivity.The results presented herein demonstrate the effect of dynamic OVs induced by interlayer tensile strain on catalysts for the enhanced selective CO_(2)photoreduction process.展开更多
lronmaking using an oxygen blast furnace is an attractive approach for reducing energy consumption in the iron and steel industry. This paper presents a numerical study of gas-solid flow in an oxygen blast fur- nace b...lronmaking using an oxygen blast furnace is an attractive approach for reducing energy consumption in the iron and steel industry. This paper presents a numerical study of gas-solid flow in an oxygen blast fur- nace by coupling the discrete element method with computational fluid dynamics. The model reliability was verified by previous experimental results. The influences of particle diameter, shaft tuyere size, and specific ratio （X） of shaft-injected gas （51G） flowrate to total gas flowrate on the SIC penetration behavior and pressure field in the furnace were investigated. The results showed that gas penetration capacity in the furnace gradually decreased as the particle diameter decreased from 100 to 40 mm. Decreasing particle diameter and increasing shaft tuyere size both slightly increased the SIG concentration near the furnace wall but decreased it at the furnace center. The value of X has a significant impact on the SIG distribution. According to the pressure fields obtained under different conditions, the key factor affecting SIG penetration depth is the pressure difference between the upper and lower levels of the shaft tuyere. If the pressure difference is small, the SIG can easily penetrate to the furnace center.展开更多
The effect of Co doping on ceria-zirconia mixed oxides was investigated for Co0.1Ce0.6Zr0.3Ox sample prepared by sol-gel method. The Pd-only three-way catalyst （TWC） was obtained by incipient wetness impregnation wi...The effect of Co doping on ceria-zirconia mixed oxides was investigated for Co0.1Ce0.6Zr0.3Ox sample prepared by sol-gel method. The Pd-only three-way catalyst （TWC） was obtained by incipient wetness impregnation with 0.5 wt.% Pd loading. The structural and oxygen handling properties were analyzed by X-ray diffraction （XRD）, H2-temperature programmed reduction （H2-TPR） and the dynamic oxygen storage capacity （DOSC）. The introduction of Co into ceria-zirconia lattice strongly modified the mobility of oxygen and enhanced the DOSC performance. Pd-only TWC based on the Co0.1Ce0.6Zr0.3Ox support exhibited superior activity for water-gas shift and steam reforming and ampli- fied amplitude of stoichiometric window.展开更多
FeOx-CeO2 mixed oxides with increasing Fe/（Ce＋Fe） atomic ratio （1-20 mol%） were prepared by sol-gel method and characterized by X-ray powder diffraction （XRD）, Brunauer-Emrnett-Teller （BET） and Hydrogen tempe...FeOx-CeO2 mixed oxides with increasing Fe/（Ce＋Fe） atomic ratio （1-20 mol%） were prepared by sol-gel method and characterized by X-ray powder diffraction （XRD）, Brunauer-Emrnett-Teller （BET） and Hydrogen temperature-programmed reduction （H2-TPR） techniques. The dynamic oxygen storage capacity （DOSC） was investigated by mass spectrometry with CO/O2 transient pulses. The powder XRD data following Rietveld refinement revealed that the solubility limit of iron oxides in the CeO2 was 5 mol% based on Fe/（Ce＋Fe）. The lattice parameters experienced a decrease followed by an increase due to the influence of the maximum solubility limit of iron oxides in the CeO2. TPR analysis revealed that Fe introduction into ceria strongly modified the textual and structural properties, which influenced the oxygen handling properties. DOSC results revealed that Ce-based materials containing Fe oxides with multiple valences contribute to the majority of DOSC. The kinetic analysis indicated that the calculated apparent kinetic parameters obey the compensation effect. The three-way catalytic performance for Pd-only catalysts based on the Fe doping support exhibited the redundant iron species separated out of the CeO2 and interacted with the ceria and Pd species on the surface, which seriously influenced the catalytic properties, especially after hydrothermal aging treatment.展开更多
Background： Sepsis is one of the main canses of mortality in critically ill patients following progression to septic shock. To investigate the pathophysiologic changes of sepsis, we developed a novel porcine model of...Background： Sepsis is one of the main canses of mortality in critically ill patients following progression to septic shock. To investigate the pathophysiologic changes of sepsis, we developed a novel porcine model of septic shock induced by acute respiratory distress syndrome （ARDS） due to methicillin-resistant Staphylococcus aureus （MRSA） pneumonia. Methods： Twenty-six male Landraces （Lvyuanweiye, Beijing, China） weighing 30 - 2 kg were divided into lbur groups： sham gronp （SH： n = 5）; cotton smoke inhalation group （SM; n = 6）; MRSA pneumonia group （MR; n = 6）; and septic shock group with cotton smoke inhalation ＋ MRSA pneumonia （SS; n = 9）. Extensive hemodynamics, oxygen dynamics, and lung function were monitored for 24 11 following the injury or until death. Tissues were collected, and histopathology evaluations were carried out. Results： Blood cultures from 6 of 9 animals in the SS group were positive for MRSA. Two hours following the injury, decreased mean arterial blood pressure （60 70 mmHg） and cardiac index （〈2 L-rain -＇m --） were observed in the animals in the SS group, while systemic vascular resistance index was increased. The hemodynamic characteristics of septic shock were only observed in the SS group but not significant in the other groups, The PO_JFiO2 in the SM and SS groups decreased to 300 and 100, respectively. In the SS group, extravascular lung water index increased to 20 ml/kg, whereas thoracopulmonary compliance decreased to 10 ml/H2O after injury. Deterioration of pulmonary function in the SS group was more serious than the SM and MR groups. Severe lung injury in the SS group was confinaaed by the histopathology evaluations. The lung injury confirmed by high-resolution thin-section computed tomography and histopathology in the SS group was more serious than those of other groups. Conclusions： In the present study, we developed a novel porcine model of septic shock induced by ARDS due to severe MRSA pneumonia with characteristic hyperdynamic and hypodynamic phases in 24 h, which mimicked the hemodynamic changing of septic shock in human.展开更多
Objective: Reactive oxygen species(ROS) are involved in a variety of biological phenomena and serve both deleterious and beneficial roles. ROS quantification and assessment of reaction networks are desirable but diffi...Objective: Reactive oxygen species(ROS) are involved in a variety of biological phenomena and serve both deleterious and beneficial roles. ROS quantification and assessment of reaction networks are desirable but difficult because of their short half-life and high reactivity. Here, we describe a pro-oxidative model in a single human lung carcinoma SPC-A-1 cell that was created by application of extracellular H2O2 stimuli. Methods: Modified microfluidics and imaging techniques were used to determine O2·- levels and construct an O2^·- reaction network. To elucidate the consequences of increased O2^·- input, the mitochondria were given a central role in the oxidative stress mode, by manipulating mitochondria-interrelated cytosolic Ca2+ levels, mitochondrial Ca^2+ uptake, auto-amplification of intracellular ROS and the intrinsic apoptotic pathway. Results and conclusions: Results from a modified microchip demonstrated that 1 mmol/L H·-2 O2 induced a rapid increase in cellular O2 levels(>27 vs.>406 amol in 20 min), leading to increased cellular oxidizing power(evaluated by ROS levels) and decreased reducing power(evaluated by glutathione(GSH) levels). In addition, we examined the dynamics of cytosolic Ca^2+ and mitochondrial Ca^2+ by confocal laser scanning microscopy and confirmed that Ca^2+ stores in the endoplasmic reticulum were the primary source of H2O2-induced cytosolic Ca^2+ bursts. It is clear that mitochondria have pivotal roles in determining how exogenous oxidative stress affects cell fate. The stress response involves the transfer of Ca^2+ signals between organelles,ROS auto-amplification, mitochondrial dysfunction, and a caspase-dependent apoptotic pathway.展开更多
A series of Pt-Pd bimetallic catalysts supported on CeO_(2)-ZrO_(2)-La_(2)O_(3) mixed oxides were synthesized through the conventional impregnation method.Three-way catalytic performance evaluations along with detaile...A series of Pt-Pd bimetallic catalysts supported on CeO_(2)-ZrO_(2)-La_(2)O_(3) mixed oxides were synthesized through the conventional impregnation method.Three-way catalytic performance evaluations along with detailed physio-chemical characterizations were carried out to establish possible structure-activity correlations.Results show that on the one hand,different Pt/Pd ratios can strongly affect the TWC behaviors of Pt-Pd/CZL catalysts by modulating the synergistic effect between Pt and Pd.On the other hand,higher Pt/Pd ratio also favors better dispersion of precious metals.Such improved precious metals(PM)dispersion can promote the metal-support interaction and increase the surface oxygen vacancies concentration,thereby raising the dynamic oxygen storage/release capacity,improving the redox ability as well as enha ncing the thermal stability of the Pt-Pd/CZL catalyst.Moreover,the stro ng metal-support interaction can augment surface oxygen vacancy concentration,thereby benefiting low temperature CO and NO reaction via augmented NOxadsorption and nitrate conversion.展开更多
OBJECTIVE:The study aim was to use existing relevant indexes to establish an index series for the quantitative measurement of Qi deficiency pattern(QDP) in Traditional Chinese Medicine(TCM).METHODS:Seventeen indexes o...OBJECTIVE:The study aim was to use existing relevant indexes to establish an index series for the quantitative measurement of Qi deficiency pattern(QDP) in Traditional Chinese Medicine(TCM).METHODS:Seventeen indexes of arterial oxygen saturation(SaO_2),TCM pulse diagnosis,heart rate,and blood pressure were integrated into an index series,and 94 selected subjects were divided into a healthy control group,a mild QDP group,and a typical QDP group.All three groups were then synchronously given a breath-holding(BH) test and index detections using TCM apparatus for auxiliary diagnosis and treatment and a photoplethysmograph.The detections were carried out repeatedly until there was no monotonic change in the value of the minimal SaO_(2d)uring a BH measurement(SaO_(2 min)) or in the duration of BH during a BH measurement(TBH).RESULTS:BH measurement and index detection data from 380 eligible cases were analyzed and a significant intergroup difference was found for 12 indexes.CONCLUSION:An index series for quantitative QDP measurement could comprise the 12 effective indexes:RSaO_(2d)(rate of decline of SaO_(2d)uring a BH measurement),RSaO_(2r)(recovery rate of SaO_2 after a BH measurement),SaO_(2 min),BFV(blood flow velocity),TSaO_(2d)(the time at which SaO_2 started declining during a BH measurement),TBH,TSa_(O2 min)(the time of occurrence of the minimal SaO_(2d)uring a BH measurement),TSa O_(2 max)(the time of occurrence of the maximal SaO_2 after a BH measurement),PTP(pulse-touching pressure),SBP(systolic blood pressure),PWV(pulse wave velocity),and DBP(diastolic blood pressure).Of the indexes,RSaO_(2d)could play akey role in quantitative QDP measurement;RSaO_(2r) and Sa O_2 mincould be used to differentiate the QDP symptom of shortness of breath and as early-warning indexes for chronic obstructive pulmonary disease.BFV,TSaO_(2d),and TBHcould be used to quantitatively assess the QDP symptoms of spontaneous perspiration and shortness of breath.展开更多
基金supported by a grant from 11th Five-Year Plan Medical Science Scientific Research Fund of the Chinese People's Liberation Army(08G002)
文摘BACKGROUND:Hypothermia is associated with poor outcome in trauma patients;however,hemorrhagic shock(HS)model with anesthetized swine was different from that of clinical reality.To identify the effects of environmental hypothermia on HS,we investigated hemodynamics and oxygen dynamics in an unanesthetized swine model of HS under simulating hypothermia environment.METHODS:Totally 16 Bama pigs were randomly divided into ambient temperature group(group A)and low temperature group(group B),8 pigs in each group.Venous blood(30 mL/kg)was continuously withdrawn for more than 15 minutes in conscious swine to establish a hemorrhagic shock model.Pulmonary arterial temperature(Tp),heart rate(HR),mean arterial pressure(MAP),pulmonary arterial pressure(PAP),pulmonary arterial wedge pressure(PAWP),central venous pressure(CVP),cardiac output(CO),hemoglobin(Hb),saturation of mixed venous blood(SvO_2)and blood gas analysis were recorded at the baseline and different hemorrhagic shock time(HST).The whole body oxygen delivery indices,DO_2l and VO_2l,and the O_2 extraction ratio(O_2ER)were calculated.RESULTS:Core body temperature in group A decreased slightly after the hemorrhagic shock model was established,and environmental hypothermia decreased in core body temperature.The mortality rate was significantly higher in group B(50%)than in group A(0%).DO_2l and VO_2l decreased significantly after hemorrhage.No difference was found in hemodynamics,DO_2l and VO_2l between group A and group B,but the difference in pH,lactic acid and O_2ER was significant between the two groups.CONCLUSION:Environmental hypothermia aggravated the disorder of oxygen metabolism after hemorrhagic shock,which was associated with poor prognosis.
基金"973"National Key Basic Research and Development Program(No.2012CB518202)Project of Qinghai Development of Science and Technology(No.2011-N-150)
文摘To study monitoring hemodynamics and oxygen dynamics of adult respiratory distress syndrome (ARDS) secondary to high altitude pulmonary edema (HAPE),we performed clinic and laboratory studies in 8 patients who preliminarily developed high altitude cerebral edema (HACE) and then ARDS occurred at an altitude of 4 500 m. After an initial emergency treatment on high mountains,all the patients were rapidly transported to a hospital at a lower altitude of 2 808 m. The right cardiac catheterizations were carried out within 5 h after hospitalized. The monitoring hemodynamics and oxygen dynamics were studied via a thermodilution Swan-Gaze catheter. The results showed that before treatments at the beginning of monitoring,there presented a significant pulmonary artery hypertension with a decreased cardiac function,and a lower oxygen metabolism in all the 8 patients. However,after some effective treatments,including mechanical ventilation and using dexamethasone,furosemide,etc,four days later the result of a repeated monitoring showed that their pulmonary artery pressure had been decreased with an improved cardiac function with all the oxygen metabolic indexes increased significantly. Our studies suggested that performing monitoring hemodynamics in patients with ARDS secondary to HAPE will define the clinical therapeutic measures which will benefit the outcome.
基金the National Natural Science Foundation of China(82270595,82272237,82072223,32171402)the China Postdoctoral Science Foundation(BX20220393,2022M723891)+2 种基金the General Program of Medical Research from the Jiangsu Commission of Health(M2020052)the Jiangsu Key Research and Development Plan(BE2021727)Jiangsu Provincial Medical Innovation Center(CXZX202217).
文摘Increasing evidence demonstrates that mammals have different reactions to hypoxia with varied oxygen dynamic patterns.It takes~24 h for tri-gas incubator to achieve steady cell hypoxia,which fails to recapitulate ultrafast oxygen dynamics of intestinal ischemia/reperfusion(IR)injury.Inspired from the structure of native intestinal villi,we engineered an intestinal organoid chip embedded with engineered artificial microvessels based on coaxial microfluidic technology by using pH-responsive ZIF-8/sodium alginate scaffold.The chip was featured on:(i)eight times the oxygen exchange efficiency compared with the conventional device,tri-gas incubator,(ii)implantation of intestinal organoid reproducing all types of intestinal epithelial cells,and(iii)bio-responsiveness to hypoxia and reoxygenation(HR)by presenting metabolism disorder,inflammatory reaction,and cell apoptosis.Strikingly,it was found for the first time that Olfactomedin 4(Olfm4)was the most significantly downregulated gene under a rapid HR condition by sequencing the RNA from the organoids.Mechanistically,OLFM4 played protective functions on HR-induced cell inflammation and tissue damage by inhibiting the NF-kappa B signaling activation,thus it could be used as a therapeutic target.Altogether,this study overcomes the issue of mismatched oxygen dynamics between in vitro and in vivo,and sets an example of next-generation multisysteminteractive organoid chip for finding precise therapeutic targets of IR injury.
基金supported by the National Natural Science Foundation of China (52200123, 22225606, 22261142663)。
文摘Surface oxygen vacancies(OVs) with abundant localized electrons on bismuth-oxygen based photocatalysts are proved to have the ability to capture and activate CO_(2).However,the surface OVs are easily filled with oxygen-containing species and destroyed,losing their effects as active sites and hindering the subsequent CO_(2)photoreduction.For realistic and sustainable CO_(2)photoreduction,constructing sustainable and stable surface OVs as active sites on photocatalysts is essential.This work shows the synthesis of interlayer stretched Bi_(2)O_(2)CO_(3) ultrathin nanosheets with tensile stress,which are beneficial to continuously generating light-induced dynamic OVs.With sufficient active sites,excellent,stable,and selective photoreduction of CO_(2)to CO under simulated solar light is achieved.The light-induced OVs can reduce the energy barrier of rate-determining step,resulting in the 100% product selectivity.The results presented herein demonstrate the effect of dynamic OVs induced by interlayer tensile strain on catalysts for the enhanced selective CO_(2)photoreduction process.
基金We gratefully acknowledge the support of the National Basic Research Program of China （973 Program） （No. 2012CB720401 ） and the Key Project of National Natural Science Foundation of China （No. 51134008）.
文摘lronmaking using an oxygen blast furnace is an attractive approach for reducing energy consumption in the iron and steel industry. This paper presents a numerical study of gas-solid flow in an oxygen blast fur- nace by coupling the discrete element method with computational fluid dynamics. The model reliability was verified by previous experimental results. The influences of particle diameter, shaft tuyere size, and specific ratio （X） of shaft-injected gas （51G） flowrate to total gas flowrate on the SIC penetration behavior and pressure field in the furnace were investigated. The results showed that gas penetration capacity in the furnace gradually decreased as the particle diameter decreased from 100 to 40 mm. Decreasing particle diameter and increasing shaft tuyere size both slightly increased the SIG concentration near the furnace wall but decreased it at the furnace center. The value of X has a significant impact on the SIG distribution. According to the pressure fields obtained under different conditions, the key factor affecting SIG penetration depth is the pressure difference between the upper and lower levels of the shaft tuyere. If the pressure difference is small, the SIG can easily penetrate to the furnace center.
基金Project supported by National High-Tech Research and Development Program of China (2011AA03A405)the Key Program of Tianjin Natural Science Foundation (09JCZDJC26600)
文摘The effect of Co doping on ceria-zirconia mixed oxides was investigated for Co0.1Ce0.6Zr0.3Ox sample prepared by sol-gel method. The Pd-only three-way catalyst （TWC） was obtained by incipient wetness impregnation with 0.5 wt.% Pd loading. The structural and oxygen handling properties were analyzed by X-ray diffraction （XRD）, H2-temperature programmed reduction （H2-TPR） and the dynamic oxygen storage capacity （DOSC）. The introduction of Co into ceria-zirconia lattice strongly modified the mobility of oxygen and enhanced the DOSC performance. Pd-only TWC based on the Co0.1Ce0.6Zr0.3Ox support exhibited superior activity for water-gas shift and steam reforming and ampli- fied amplitude of stoichiometric window.
基金support the National HighTech Research and Development Program of China (No.2011AA03A405)
文摘FeOx-CeO2 mixed oxides with increasing Fe/（Ce＋Fe） atomic ratio （1-20 mol%） were prepared by sol-gel method and characterized by X-ray powder diffraction （XRD）, Brunauer-Emrnett-Teller （BET） and Hydrogen temperature-programmed reduction （H2-TPR） techniques. The dynamic oxygen storage capacity （DOSC） was investigated by mass spectrometry with CO/O2 transient pulses. The powder XRD data following Rietveld refinement revealed that the solubility limit of iron oxides in the CeO2 was 5 mol% based on Fe/（Ce＋Fe）. The lattice parameters experienced a decrease followed by an increase due to the influence of the maximum solubility limit of iron oxides in the CeO2. TPR analysis revealed that Fe introduction into ceria strongly modified the textual and structural properties, which influenced the oxygen handling properties. DOSC results revealed that Ce-based materials containing Fe oxides with multiple valences contribute to the majority of DOSC. The kinetic analysis indicated that the calculated apparent kinetic parameters obey the compensation effect. The three-way catalytic performance for Pd-only catalysts based on the Fe doping support exhibited the redundant iron species separated out of the CeO2 and interacted with the ceria and Pd species on the surface, which seriously influenced the catalytic properties, especially after hydrothermal aging treatment.
文摘Background： Sepsis is one of the main canses of mortality in critically ill patients following progression to septic shock. To investigate the pathophysiologic changes of sepsis, we developed a novel porcine model of septic shock induced by acute respiratory distress syndrome （ARDS） due to methicillin-resistant Staphylococcus aureus （MRSA） pneumonia. Methods： Twenty-six male Landraces （Lvyuanweiye, Beijing, China） weighing 30 - 2 kg were divided into lbur groups： sham gronp （SH： n = 5）; cotton smoke inhalation group （SM; n = 6）; MRSA pneumonia group （MR; n = 6）; and septic shock group with cotton smoke inhalation ＋ MRSA pneumonia （SS; n = 9）. Extensive hemodynamics, oxygen dynamics, and lung function were monitored for 24 11 following the injury or until death. Tissues were collected, and histopathology evaluations were carried out. Results： Blood cultures from 6 of 9 animals in the SS group were positive for MRSA. Two hours following the injury, decreased mean arterial blood pressure （60 70 mmHg） and cardiac index （〈2 L-rain -＇m --） were observed in the animals in the SS group, while systemic vascular resistance index was increased. The hemodynamic characteristics of septic shock were only observed in the SS group but not significant in the other groups, The PO_JFiO2 in the SM and SS groups decreased to 300 and 100, respectively. In the SS group, extravascular lung water index increased to 20 ml/kg, whereas thoracopulmonary compliance decreased to 10 ml/H2O after injury. Deterioration of pulmonary function in the SS group was more serious than the SM and MR groups. Severe lung injury in the SS group was confinaaed by the histopathology evaluations. The lung injury confirmed by high-resolution thin-section computed tomography and histopathology in the SS group was more serious than those of other groups. Conclusions： In the present study, we developed a novel porcine model of septic shock induced by ARDS due to severe MRSA pneumonia with characteristic hyperdynamic and hypodynamic phases in 24 h, which mimicked the hemodynamic changing of septic shock in human.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(No.LY18H300002)the Medical Health Science and Technology Project of Zhejiang Provincial Health Commission(No.2019RC061/2019312897)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(Nos.Y4110212 and LY19H090001)partly by the National Natural Science Foundation of China(Nos.81372301 and 81301113)
文摘Objective: Reactive oxygen species(ROS) are involved in a variety of biological phenomena and serve both deleterious and beneficial roles. ROS quantification and assessment of reaction networks are desirable but difficult because of their short half-life and high reactivity. Here, we describe a pro-oxidative model in a single human lung carcinoma SPC-A-1 cell that was created by application of extracellular H2O2 stimuli. Methods: Modified microfluidics and imaging techniques were used to determine O2·- levels and construct an O2^·- reaction network. To elucidate the consequences of increased O2^·- input, the mitochondria were given a central role in the oxidative stress mode, by manipulating mitochondria-interrelated cytosolic Ca2+ levels, mitochondrial Ca^2+ uptake, auto-amplification of intracellular ROS and the intrinsic apoptotic pathway. Results and conclusions: Results from a modified microchip demonstrated that 1 mmol/L H·-2 O2 induced a rapid increase in cellular O2 levels(>27 vs.>406 amol in 20 min), leading to increased cellular oxidizing power(evaluated by ROS levels) and decreased reducing power(evaluated by glutathione(GSH) levels). In addition, we examined the dynamics of cytosolic Ca^2+ and mitochondrial Ca^2+ by confocal laser scanning microscopy and confirmed that Ca^2+ stores in the endoplasmic reticulum were the primary source of H2O2-induced cytosolic Ca^2+ bursts. It is clear that mitochondria have pivotal roles in determining how exogenous oxidative stress affects cell fate. The stress response involves the transfer of Ca^2+ signals between organelles,ROS auto-amplification, mitochondrial dysfunction, and a caspase-dependent apoptotic pathway.
基金Project supported by the Key Program of Science Technology Department of Zhejiang Province(2018C03037)the Natural Science Foundation of Jiangsu Province(BK20201037)+2 种基金Jiangsu Industry-University-Research Cooperation Project(BY2022101)the Scientific Research Fund of Nanjing Institute of Technology(YKJ2019111)Students'Science and Technology Innovation Fund of Nanjing Institute of Technology(TB202312034).
文摘A series of Pt-Pd bimetallic catalysts supported on CeO_(2)-ZrO_(2)-La_(2)O_(3) mixed oxides were synthesized through the conventional impregnation method.Three-way catalytic performance evaluations along with detailed physio-chemical characterizations were carried out to establish possible structure-activity correlations.Results show that on the one hand,different Pt/Pd ratios can strongly affect the TWC behaviors of Pt-Pd/CZL catalysts by modulating the synergistic effect between Pt and Pd.On the other hand,higher Pt/Pd ratio also favors better dispersion of precious metals.Such improved precious metals(PM)dispersion can promote the metal-support interaction and increase the surface oxygen vacancies concentration,thereby raising the dynamic oxygen storage/release capacity,improving the redox ability as well as enha ncing the thermal stability of the Pt-Pd/CZL catalyst.Moreover,the stro ng metal-support interaction can augment surface oxygen vacancy concentration,thereby benefiting low temperature CO and NO reaction via augmented NOxadsorption and nitrate conversion.
基金National Natural Science Foundation-funded project:Construction of the Qi-Blood-Body Fluid Network Based on the Dynamic Detection of Human Biological Information and Research on the Network's Mechanism of Identification,a program funded by the of China(No.81473553)National Natural Science Foundation-funded project:Construction of TCM Qi-Function Biological Network Based on the Body Odor and Voice and Research on the Network's Mechanism(No.81573880)+1 种基金Science and Technology Assistance Project of the Ministry of Science and Technology of China to the Developing Countries:Sino-Mexican Cooperation Study on the Strategies for Hospice Care with the Intervention of Acupuncture and Moxibustion and the Related Clinical Research(No.KYZ201302010)Longitudinal scientific research development fund,Beijing University of Chinese Medicine:Key Technology of Photographic Identification for Meridian-Visceral Recuperation Device(No.2017-zxfzjj-024)
文摘OBJECTIVE:The study aim was to use existing relevant indexes to establish an index series for the quantitative measurement of Qi deficiency pattern(QDP) in Traditional Chinese Medicine(TCM).METHODS:Seventeen indexes of arterial oxygen saturation(SaO_2),TCM pulse diagnosis,heart rate,and blood pressure were integrated into an index series,and 94 selected subjects were divided into a healthy control group,a mild QDP group,and a typical QDP group.All three groups were then synchronously given a breath-holding(BH) test and index detections using TCM apparatus for auxiliary diagnosis and treatment and a photoplethysmograph.The detections were carried out repeatedly until there was no monotonic change in the value of the minimal SaO_(2d)uring a BH measurement(SaO_(2 min)) or in the duration of BH during a BH measurement(TBH).RESULTS:BH measurement and index detection data from 380 eligible cases were analyzed and a significant intergroup difference was found for 12 indexes.CONCLUSION:An index series for quantitative QDP measurement could comprise the 12 effective indexes:RSaO_(2d)(rate of decline of SaO_(2d)uring a BH measurement),RSaO_(2r)(recovery rate of SaO_2 after a BH measurement),SaO_(2 min),BFV(blood flow velocity),TSaO_(2d)(the time at which SaO_2 started declining during a BH measurement),TBH,TSa_(O2 min)(the time of occurrence of the minimal SaO_(2d)uring a BH measurement),TSa O_(2 max)(the time of occurrence of the maximal SaO_2 after a BH measurement),PTP(pulse-touching pressure),SBP(systolic blood pressure),PWV(pulse wave velocity),and DBP(diastolic blood pressure).Of the indexes,RSaO_(2d)could play akey role in quantitative QDP measurement;RSaO_(2r) and Sa O_2 mincould be used to differentiate the QDP symptom of shortness of breath and as early-warning indexes for chronic obstructive pulmonary disease.BFV,TSaO_(2d),and TBHcould be used to quantitatively assess the QDP symptoms of spontaneous perspiration and shortness of breath.
