Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN...Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN/Cu nanocomposite coatings with various N_(2) partial pressures were deposited on 304 stainless steels(SS)using an arc ion plating(AIP)system,named TiN/Cu-x(x=0.5,1.0,1.5 Pa).The results of X-ray diffraction analysis,energy-dispersive X-ray spectroscopy,and scanning electron microscopy showed that the N_(2) partial pressures determined the Cu contents,surface defects,and crystallite sizes of TiN/Cu nanocomposite coatings,which further influenced the comprehensive abilities.And the hardness and wear resistances of TiN/Cu coatings were enhanced with increase of the crystallite sizes.Under the co-actions of surface defects,crystallite sizes,and Cu content,TiN/Cu-1.0 and TiN/Cu-1.5 coatings possessed excellent corrosion resistance.Besides,the biological tests proved that all the TiN/Cu coatings showed no cytotoxicity with strong antibacterial ability.Among them,TiN/Cu-1.5 coating significantly promoted the cell proliferation,which is expected to be a novel antibacterial,corrosion-resistant,and wear-resistant coating on the surfaces of medical implants.展开更多
The effect of COpartial pressure was evaluated during the COchemisorption in penta lithium aluminate(LiAlO), using different COand Opartial pressures in the presence or absence of alkaline carbonates. Results showed...The effect of COpartial pressure was evaluated during the COchemisorption in penta lithium aluminate(LiAlO), using different COand Opartial pressures in the presence or absence of alkaline carbonates. Results showed that using low PO(0.1) did not affect the kinetic and final COchemisorption process. Moreover, small additions of oxygen(PO= 0.05) into the mixture flue gas, seemed to increase the COchemisorption. Additionally, the presence of alkaline carbonates modified the COcapture temperature range. COchemisorption kinetic parameters were determined assuming a double exponential model where direct COchemisorption and COchemisorption controlled by diffusion processes are considered.Finally, ionic diffusion was analyzed by ionic conduction analysis, where all the gravimetric and ionic measurements were in good agreement showing different diffusion processes depending on temperature.Finally, the oxygen and alkaline carbonate additions have positive effects during the COchemisorption process in LiAlO, and a possible reaction mechanism is presented.展开更多
Copper nitride thin films were deposited on glass substrates by reactive direct current (DC) magnetron sputtering at various N2-gas partial pressures and room temperature. Xray diffraction measurements showed that t...Copper nitride thin films were deposited on glass substrates by reactive direct current (DC) magnetron sputtering at various N2-gas partial pressures and room temperature. Xray diffraction measurements showed that the films were composed of Cu3N crystallites and exhibited a preferential orientation of the [111] direction at a low nitrogen gas (N2) partial pressure. The film growth preferred the [111] and the [100] direction at a high N2 partial pressure. Such preferential film growth is interpreted as being due to the variation in the Copper (Cu) nitrification rate with the N2 pressure. The N2 partial pressure affects not only the crystal structure of the film but also the deposition rate and the resistivity of the Cu3N film. In our experiment, the deposition rate of Cu3N films was 18 nm/min to 30 nm/min and increased with the N2 partial pressure. The resistivity of the Cu3N films increased sharply with the increasing N2 partial pressure. At a low N2 partial pressure, the Cu3N films showed a metallic conduction mechanism through the Cu path, and at a high N2 partial pressure, the conductivity of the Cu3N films showed a semiconductor conduction mechanism.展开更多
Carbon dioxide(CO_(2))emissions from aquatic ecosystems are an important component of the karst carbon cycle process and also a key indicator for assessing the effect of karst carbon sinks.This paper reviewed the CO_(...Carbon dioxide(CO_(2))emissions from aquatic ecosystems are an important component of the karst carbon cycle process and also a key indicator for assessing the effect of karst carbon sinks.This paper reviewed the CO_(2)partial pressure(pCO_(2))and its diffusion flux(FCO_(2))in karst surface aquatic ecosystems,mainly rivers,lakes,and reservoirs,and their influencing factors summarized the methods for monitoring CO_(2)emissions in karst aquatic ecosystems and discussed their adaptation conditions in karst areas.The pCO_(2)and FCO_(2)decreased in the order of rivers>reservoirs>lakes,and the values in karst lakes were eventually significantly lower than those in global lakes.The pCO_(2)and FCO_(2)of karst aquatic ecosystems had patterns of variation with diurnal,seasonal,water depth and hydrological cycles,and spatial and temporal hetero-geneity.The sources of CO_(2)in karst waters are influenced by both internal and external sources,and the key spatial and temporal factors affecting the CO_(2)emissions from karst rivers,lakes,and reservoirs were determined in terms of physicochemical indicators,biological factors,and bio-genic elements;additionally,the process of human activity interference on CO_(2)emissions was discussed.Finally,a conceptual model illustrating the impacts of urban devel-opment,agriculture,mining,and dam construction on the CO_(2)emissions at the karst surface aquatic ecosystem is presented.Meanwhile,based on the disadvantages existing in current research,we proposed several important research fields related to CO_(2)emissions from karst surface aquatic ecosystems.展开更多
BACKGROUND: Partial pressure of end-tidal carbon dioxide(PETCO2) has been used to monitor the effectiveness of precordial compression(PC) and regarded as a prognostic value of outcomes in cardiopulmonary resuscitation...BACKGROUND: Partial pressure of end-tidal carbon dioxide(PETCO2) has been used to monitor the effectiveness of precordial compression(PC) and regarded as a prognostic value of outcomes in cardiopulmonary resuscitation(CPR). This study was to investigate changes of PETCO2 during CPR in rats with ventricular fi brillation(VF) versus asphyxial cardiac arrest.METHODS: Sixty-two male Sprague-Dawley(SD) rats were randomly divided into an asphyxial group(n=32) and a VF group(n=30). PETCO2 was measured during CPR from a 6-minute period of VF or asphyxial cardiac arrest.RESULTS: The initial values of PETCO2 immediately after PC in the VF group were signifi cantly lower than those in the asphyxial group(12.8±4.87 mmHg vs. 49.2±8.13 mmHg, P=0.000). In the VF group, the values of PETCO2 after 6 minutes of PC were significantly higher in rats with return of spontaneous circulation(ROSC), compared with those in rats without ROSC(16.5±3.07 mmHg vs. 13.2±2.62 mmHg, P=0.004). In the asphyxial group, the values of PETCO2 after 2 minutes of PC in rats with ROSC were signifi cantly higher than those in rats without ROSC(20.8±3.24 mmHg vs. 13.9±1.50 mmHg, P=0.000). Receiver operator characteristic(ROC) curves of PETCO2 showed signifi cant sensitivity and specifi city for predicting ROSC in VF versus asphyxial cardiac arrest.CONCLUSIONS: The initial values of PETCO2 immediately after CPR may be helpful in differentiating the causes of cardiac arrest. Changes of PETCO2 during CPR can predict outcomes of CPR.展开更多
The 3rd Chinese National Arctic Research Expedition (CHINARE-Arctic III) was carried out from July to September in 2008. The partial pressure of CO2 (pCO2) in the atmosphere and in surface seawater were determined...The 3rd Chinese National Arctic Research Expedition (CHINARE-Arctic III) was carried out from July to September in 2008. The partial pressure of CO2 (pCO2) in the atmosphere and in surface seawater were determined in the Bering Sea during luly 11-27, 2008, and a large number of seawater samples were taken for total alkalinity (TA) and total dissolved inorganic carbon (DIC) analysis. The distributions of CO2 parameters in the Bering Sea and their controlling factors were discussed. The pCO2 values in surface seawater presented a drastic variation from 148 to 563 laatm (1 μatm = 1.013 25× 10-1Pa). The lowest pCOz values were observed near the Bering Sea shelf break while the highest pCO2 existed at the western Bering Strait. The Bering Sea generally acts as a net sink for atmospheric CO2 in summer. The air-sea CO2 fluxes in the Bering Sea shelf, slope, and basin were estimated at -9.4, -16.3, and -5.1 mmol/(m2.d), respectively. The annual uptake of CO2 was about 34 Tg C in the Bering Sea.展开更多
The third Chinese National Arctic Research Expedition (CHINARE) was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 (pCO2) was measured, and sea water samples were ...The third Chinese National Arctic Research Expedition (CHINARE) was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 (pCO2) was measured, and sea water samples were collected for CO2 measurement in the Canada Basin. The distribution of pCO2 in the Canada Basin was determined, the influencing factors were addressed, and the air-sea CO2 flux in the Canada Basin was evaluated. The Canada Basin was divided into three regions: the ice-free zone (south of 77°N), the partially ice-covered zone (77°-80°N), and the heavily ice-covered zone (north of 80°N). In the ice-free zone, pCO2 was high (320 to 368 patm, 1 patm=0.101 325 Pa), primarily due to rapid equilibration with atmospheric CO2 over a short time. In the partially ice-covered zone, the surface pCOs was relatively low (250 to 270 patm) due to ice-edge blooms and icemelt water dilution. In the heavily ice-covered zone, the seawater pCO2 varied between 270 and 300 laatm due to biological COs removal, the transportation of low pCOs water northward, and heavy ice cover. The surface seawater pCO2 during the survey was undersaturated with respect to the atmosphere in the Canada Basin, and it was a net sink for atmospheric CO2. The summertime net CO2 uptake of the ice-free zone, the partially ice-covered zone and the heavily ice-covered zone was (4.14±1.08), (1.79±0.19), and (0.57±0.03) Tg/a (calculated by carbon, 1 Tg=10^12 g), respectively. Overall, the net COs sink of the Canada Basin in the summer of 2008 was (6.5+1.3) Tg/a, which accounted for 4%-10% of the Arctic Ocean COs sink.展开更多
The distributions and relationships of O_2, CO_2, and dimethylsulfide (DMS) in the Changjiang (Yangtze) Estuary and its adjacent waters were investigated in June 2014. In surface water, mean O_2 saturation level, part...The distributions and relationships of O_2, CO_2, and dimethylsulfide (DMS) in the Changjiang (Yangtze) Estuary and its adjacent waters were investigated in June 2014. In surface water, mean O_2 saturation level, partial pressure of CO_2 (pCO_2), and DMS concentrations (and ranges) were 110% (89%–167%), 374μatm (91–640 μatm), and 8.53 nmol L^(-1) (1.10–27.50 nmol L^(-1)), respectively. The sea-to-air fluxes (and ranges) of DMS and CO_2 were 8.24 μmol m^(-2)d^(-1) (0.26–62.77 μmol m^(-2)d^(-1)), and -4.7 mmol m^(-2)d^(-1) (-110.8-31.7 mmol m^(-2)d^(-1)), respectively. Dissolved O_2 was oversaturated, DMS concentrations were relatively high, and this region served as a sink of atmospheric CO_2. The pCO_2 was significantly and negatively correlated with the O_2 saturation level, while the DMS concentration showed different positive relationships with the O_2 saturation level in different water masses. In vertical profiles, a hypoxic zone existed below 20 m at a longitude of 123?E. The stratification of temperature and salinity caused by the Taiwan Warm Current suppressed seawater exchange between upper and lower layers, resulting in the formation of a hypoxic zone. Oxidative de-composition of organic detritus carried by the Changjiang River Diluted Water (CRDW) consumed abundant O_2 and produced additional CO_2. The DMS concentrations decreased because of low phytoplankton biomass in the hypoxic zone. Strong correlations ap-peared between the O_2 saturation level, pCO_2 and DMS concentrations in vertical profiles. Our results strongly suggested that CRDW played an important role in the distributions and relationships of O_2, CO_2, and DMS.展开更多
Fourty-eight patients (ASA physical status Ⅰ - Ⅱ) undergoing selected thoracotomy and pulmonectomy were studied. They were divided into two groups according to different respiratory modes, two-lung ventilation (TLV)...Fourty-eight patients (ASA physical status Ⅰ - Ⅱ) undergoing selected thoracotomy and pulmonectomy were studied. They were divided into two groups according to different respiratory modes, two-lung ventilation (TLV) and onelung ventilation (OLV) or TLV and OLV with a Bain cyclic system for CPAP on the side of operated lung. PETCO2 and PaCO2 were measured after 30 min TLV,30 min and 60 min OLV, and repeated TLV (R-TLV) 30 min after pulmonectomy, to evaluate the difference between PETCO2 and PaCO2 in OLV and to observethe effect of abating hypoxemia and discharge of CO2 in OLV with Bain system.Our results showed that the PaCO2 and PETCO2 in different test groups were normal though the measured values in OLV were slightly higher than that in TLV (P<0. 05) , and then they were recovered after R-TLV (P>0. 05). There was nosignificant difference between group 1. and 2. in OLV (P>0. 05). There was aclose correlation between PETCO2 and PaCO2 (P<0. 05). The differences of the calculated P(a-ET)CO2 and radio of PETCO2/PaCO2 in different ventilation modes were not significant. Hypoxemia in OLV was corrected by Bain system, but the discharge of CO2 was not affected. The results showed that measurement of PET CO2 as a non-invasive procedure can be commonly used to monitor OLV.展开更多
Background: We investigated the differences between partial pressure of arterial carbon dioxide and end-tidal carbon dioxide (P(a-ET)CO2) with respect to the Broca-Katsura index (BKI), which is an obesity index, in ob...Background: We investigated the differences between partial pressure of arterial carbon dioxide and end-tidal carbon dioxide (P(a-ET)CO2) with respect to the Broca-Katsura index (BKI), which is an obesity index, in obese patients during general anesthesia. Materials and Methods: From January 2003 to December 2013, we studied 601 patients aged 16 years old or over undergoing general anesthesia. Patients had American Society of Anesthesiology physical status I and II and we reviewed their anesthetic charts. The P(a-ET)CO2 with respect to the BKI divided patients into two groups: 16 to 2 values between the two groups. Results: In patients aged 16 to 2 was 2.2 ± 3.1 mmHg at BKI 2 was 3.2 ± 4.1 mmHg at BKI 2 tends to increase in obese patients during general anesthesia with increasing BKI in patients aged 16 to < 65 years old.展开更多
基金financially supported by National Key Research and Development Program of China (Nos. 2018YFC1106601 and 2016YFC1100601)Liaoning Revitalization Talents Program (No. XLYC1807069)+1 种基金National Natural Science Foundation of China (Nos. 51631009 and 31870954)Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences (No. 174321KYSB20180006)
文摘Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN/Cu nanocomposite coatings with various N_(2) partial pressures were deposited on 304 stainless steels(SS)using an arc ion plating(AIP)system,named TiN/Cu-x(x=0.5,1.0,1.5 Pa).The results of X-ray diffraction analysis,energy-dispersive X-ray spectroscopy,and scanning electron microscopy showed that the N_(2) partial pressures determined the Cu contents,surface defects,and crystallite sizes of TiN/Cu nanocomposite coatings,which further influenced the comprehensive abilities.And the hardness and wear resistances of TiN/Cu coatings were enhanced with increase of the crystallite sizes.Under the co-actions of surface defects,crystallite sizes,and Cu content,TiN/Cu-1.0 and TiN/Cu-1.5 coatings possessed excellent corrosion resistance.Besides,the biological tests proved that all the TiN/Cu coatings showed no cytotoxicity with strong antibacterial ability.Among them,TiN/Cu-1.5 coating significantly promoted the cell proliferation,which is expected to be a novel antibacterial,corrosion-resistant,and wear-resistant coating on the surfaces of medical implants.
基金financially supported by the projects PAPIITUNAM(IN-101916)SENER-CONACYT(251801)+1 种基金CONACYTDGAPA-UNAM for financial support
文摘The effect of COpartial pressure was evaluated during the COchemisorption in penta lithium aluminate(LiAlO), using different COand Opartial pressures in the presence or absence of alkaline carbonates. Results showed that using low PO(0.1) did not affect the kinetic and final COchemisorption process. Moreover, small additions of oxygen(PO= 0.05) into the mixture flue gas, seemed to increase the COchemisorption. Additionally, the presence of alkaline carbonates modified the COcapture temperature range. COchemisorption kinetic parameters were determined assuming a double exponential model where direct COchemisorption and COchemisorption controlled by diffusion processes are considered.Finally, ionic diffusion was analyzed by ionic conduction analysis, where all the gravimetric and ionic measurements were in good agreement showing different diffusion processes depending on temperature.Finally, the oxygen and alkaline carbonate additions have positive effects during the COchemisorption process in LiAlO, and a possible reaction mechanism is presented.
基金the Key Programme of the Education Department of Hubei Province,China(2003A001,D200529002)
文摘Copper nitride thin films were deposited on glass substrates by reactive direct current (DC) magnetron sputtering at various N2-gas partial pressures and room temperature. Xray diffraction measurements showed that the films were composed of Cu3N crystallites and exhibited a preferential orientation of the [111] direction at a low nitrogen gas (N2) partial pressure. The film growth preferred the [111] and the [100] direction at a high N2 partial pressure. Such preferential film growth is interpreted as being due to the variation in the Copper (Cu) nitrification rate with the N2 pressure. The N2 partial pressure affects not only the crystal structure of the film but also the deposition rate and the resistivity of the Cu3N film. In our experiment, the deposition rate of Cu3N films was 18 nm/min to 30 nm/min and increased with the N2 partial pressure. The resistivity of the Cu3N films increased sharply with the increasing N2 partial pressure. At a low N2 partial pressure, the Cu3N films showed a metallic conduction mechanism through the Cu path, and at a high N2 partial pressure, the conductivity of the Cu3N films showed a semiconductor conduction mechanism.
基金supported by the National Natural Science Foundation of China(42163003)the Project of Talent Base in Guizhou Province(No.RCJD2018-21).
文摘Carbon dioxide(CO_(2))emissions from aquatic ecosystems are an important component of the karst carbon cycle process and also a key indicator for assessing the effect of karst carbon sinks.This paper reviewed the CO_(2)partial pressure(pCO_(2))and its diffusion flux(FCO_(2))in karst surface aquatic ecosystems,mainly rivers,lakes,and reservoirs,and their influencing factors summarized the methods for monitoring CO_(2)emissions in karst aquatic ecosystems and discussed their adaptation conditions in karst areas.The pCO_(2)and FCO_(2)decreased in the order of rivers>reservoirs>lakes,and the values in karst lakes were eventually significantly lower than those in global lakes.The pCO_(2)and FCO_(2)of karst aquatic ecosystems had patterns of variation with diurnal,seasonal,water depth and hydrological cycles,and spatial and temporal hetero-geneity.The sources of CO_(2)in karst waters are influenced by both internal and external sources,and the key spatial and temporal factors affecting the CO_(2)emissions from karst rivers,lakes,and reservoirs were determined in terms of physicochemical indicators,biological factors,and bio-genic elements;additionally,the process of human activity interference on CO_(2)emissions was discussed.Finally,a conceptual model illustrating the impacts of urban devel-opment,agriculture,mining,and dam construction on the CO_(2)emissions at the karst surface aquatic ecosystem is presented.Meanwhile,based on the disadvantages existing in current research,we proposed several important research fields related to CO_(2)emissions from karst surface aquatic ecosystems.
基金supported in part by grants from the National Natural Science Foundation of China(30700303)the National Clinical Key Subject Construction Project
文摘BACKGROUND: Partial pressure of end-tidal carbon dioxide(PETCO2) has been used to monitor the effectiveness of precordial compression(PC) and regarded as a prognostic value of outcomes in cardiopulmonary resuscitation(CPR). This study was to investigate changes of PETCO2 during CPR in rats with ventricular fi brillation(VF) versus asphyxial cardiac arrest.METHODS: Sixty-two male Sprague-Dawley(SD) rats were randomly divided into an asphyxial group(n=32) and a VF group(n=30). PETCO2 was measured during CPR from a 6-minute period of VF or asphyxial cardiac arrest.RESULTS: The initial values of PETCO2 immediately after PC in the VF group were signifi cantly lower than those in the asphyxial group(12.8±4.87 mmHg vs. 49.2±8.13 mmHg, P=0.000). In the VF group, the values of PETCO2 after 6 minutes of PC were significantly higher in rats with return of spontaneous circulation(ROSC), compared with those in rats without ROSC(16.5±3.07 mmHg vs. 13.2±2.62 mmHg, P=0.004). In the asphyxial group, the values of PETCO2 after 2 minutes of PC in rats with ROSC were signifi cantly higher than those in rats without ROSC(20.8±3.24 mmHg vs. 13.9±1.50 mmHg, P=0.000). Receiver operator characteristic(ROC) curves of PETCO2 showed signifi cant sensitivity and specifi city for predicting ROSC in VF versus asphyxial cardiac arrest.CONCLUSIONS: The initial values of PETCO2 immediately after CPR may be helpful in differentiating the causes of cardiac arrest. Changes of PETCO2 during CPR can predict outcomes of CPR.
基金The National Natural Science Foundation of China (NSFC) under contract Nos 40976116 and 40531007the Fujian Science Foundation under contract No.2009J06025+3 种基金the SOA Youth Foundation Grant under contract No.2012538the Chinese Projects for Investigations and Assessments of the Arctic and Antarctic under contract Nos CHINARE2012: 01-04, 02-01, 03-04, 04-03, 04-04, and CHINARE2013: 01-04, 02-01, 03-04, 04-03, 04-04the Chinese International Cooperation Projects under contract Nos IC201114, IC201201, IC201308, and HC120601the Scientific Research Foundation of Third Institute of Oceanography, SOA under contract Nos 2012006 and 2014006
文摘The 3rd Chinese National Arctic Research Expedition (CHINARE-Arctic III) was carried out from July to September in 2008. The partial pressure of CO2 (pCO2) in the atmosphere and in surface seawater were determined in the Bering Sea during luly 11-27, 2008, and a large number of seawater samples were taken for total alkalinity (TA) and total dissolved inorganic carbon (DIC) analysis. The distributions of CO2 parameters in the Bering Sea and their controlling factors were discussed. The pCO2 values in surface seawater presented a drastic variation from 148 to 563 laatm (1 μatm = 1.013 25× 10-1Pa). The lowest pCOz values were observed near the Bering Sea shelf break while the highest pCO2 existed at the western Bering Strait. The Bering Sea generally acts as a net sink for atmospheric CO2 in summer. The air-sea CO2 fluxes in the Bering Sea shelf, slope, and basin were estimated at -9.4, -16.3, and -5.1 mmol/(m2.d), respectively. The annual uptake of CO2 was about 34 Tg C in the Bering Sea.
基金The National Natural Science Foundation of China(NSFC) under contract Nos 41476173 and 41406221the Chinese Projects for Investigations and Assessments of the Arctic and Ant Arctic under contract Nos CHINARE2012-04-04 and 2012-04-03+1 种基金the Fujian Science and Technology Innovation Leader Project 2016the Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2014006
文摘The third Chinese National Arctic Research Expedition (CHINARE) was conducted in the summer of 2008. During the survey, the surface seawater partial pressure of CO2 (pCO2) was measured, and sea water samples were collected for CO2 measurement in the Canada Basin. The distribution of pCO2 in the Canada Basin was determined, the influencing factors were addressed, and the air-sea CO2 flux in the Canada Basin was evaluated. The Canada Basin was divided into three regions: the ice-free zone (south of 77°N), the partially ice-covered zone (77°-80°N), and the heavily ice-covered zone (north of 80°N). In the ice-free zone, pCO2 was high (320 to 368 patm, 1 patm=0.101 325 Pa), primarily due to rapid equilibration with atmospheric CO2 over a short time. In the partially ice-covered zone, the surface pCOs was relatively low (250 to 270 patm) due to ice-edge blooms and icemelt water dilution. In the heavily ice-covered zone, the seawater pCO2 varied between 270 and 300 laatm due to biological COs removal, the transportation of low pCOs water northward, and heavy ice cover. The surface seawater pCO2 during the survey was undersaturated with respect to the atmosphere in the Canada Basin, and it was a net sink for atmospheric CO2. The summertime net CO2 uptake of the ice-free zone, the partially ice-covered zone and the heavily ice-covered zone was (4.14±1.08), (1.79±0.19), and (0.57±0.03) Tg/a (calculated by carbon, 1 Tg=10^12 g), respectively. Overall, the net COs sink of the Canada Basin in the summer of 2008 was (6.5+1.3) Tg/a, which accounted for 4%-10% of the Arctic Ocean COs sink.
基金financially supported by the National Key Research and Development Program of China (No.2016YFA06 01301)the National Natural Science Foundation of China (Nos.41176062,41676065)the Fundamental Research Funds for the Central Universities (No.201564015)
文摘The distributions and relationships of O_2, CO_2, and dimethylsulfide (DMS) in the Changjiang (Yangtze) Estuary and its adjacent waters were investigated in June 2014. In surface water, mean O_2 saturation level, partial pressure of CO_2 (pCO_2), and DMS concentrations (and ranges) were 110% (89%–167%), 374μatm (91–640 μatm), and 8.53 nmol L^(-1) (1.10–27.50 nmol L^(-1)), respectively. The sea-to-air fluxes (and ranges) of DMS and CO_2 were 8.24 μmol m^(-2)d^(-1) (0.26–62.77 μmol m^(-2)d^(-1)), and -4.7 mmol m^(-2)d^(-1) (-110.8-31.7 mmol m^(-2)d^(-1)), respectively. Dissolved O_2 was oversaturated, DMS concentrations were relatively high, and this region served as a sink of atmospheric CO_2. The pCO_2 was significantly and negatively correlated with the O_2 saturation level, while the DMS concentration showed different positive relationships with the O_2 saturation level in different water masses. In vertical profiles, a hypoxic zone existed below 20 m at a longitude of 123?E. The stratification of temperature and salinity caused by the Taiwan Warm Current suppressed seawater exchange between upper and lower layers, resulting in the formation of a hypoxic zone. Oxidative de-composition of organic detritus carried by the Changjiang River Diluted Water (CRDW) consumed abundant O_2 and produced additional CO_2. The DMS concentrations decreased because of low phytoplankton biomass in the hypoxic zone. Strong correlations ap-peared between the O_2 saturation level, pCO_2 and DMS concentrations in vertical profiles. Our results strongly suggested that CRDW played an important role in the distributions and relationships of O_2, CO_2, and DMS.
文摘Fourty-eight patients (ASA physical status Ⅰ - Ⅱ) undergoing selected thoracotomy and pulmonectomy were studied. They were divided into two groups according to different respiratory modes, two-lung ventilation (TLV) and onelung ventilation (OLV) or TLV and OLV with a Bain cyclic system for CPAP on the side of operated lung. PETCO2 and PaCO2 were measured after 30 min TLV,30 min and 60 min OLV, and repeated TLV (R-TLV) 30 min after pulmonectomy, to evaluate the difference between PETCO2 and PaCO2 in OLV and to observethe effect of abating hypoxemia and discharge of CO2 in OLV with Bain system.Our results showed that the PaCO2 and PETCO2 in different test groups were normal though the measured values in OLV were slightly higher than that in TLV (P<0. 05) , and then they were recovered after R-TLV (P>0. 05). There was nosignificant difference between group 1. and 2. in OLV (P>0. 05). There was aclose correlation between PETCO2 and PaCO2 (P<0. 05). The differences of the calculated P(a-ET)CO2 and radio of PETCO2/PaCO2 in different ventilation modes were not significant. Hypoxemia in OLV was corrected by Bain system, but the discharge of CO2 was not affected. The results showed that measurement of PET CO2 as a non-invasive procedure can be commonly used to monitor OLV.
文摘Background: We investigated the differences between partial pressure of arterial carbon dioxide and end-tidal carbon dioxide (P(a-ET)CO2) with respect to the Broca-Katsura index (BKI), which is an obesity index, in obese patients during general anesthesia. Materials and Methods: From January 2003 to December 2013, we studied 601 patients aged 16 years old or over undergoing general anesthesia. Patients had American Society of Anesthesiology physical status I and II and we reviewed their anesthetic charts. The P(a-ET)CO2 with respect to the BKI divided patients into two groups: 16 to 2 values between the two groups. Results: In patients aged 16 to 2 was 2.2 ± 3.1 mmHg at BKI 2 was 3.2 ± 4.1 mmHg at BKI 2 tends to increase in obese patients during general anesthesia with increasing BKI in patients aged 16 to < 65 years old.