Chlorophyll-a(Chl-a)concentration is a primary indicator for marine environmental monitoring.The spatio-temporal variations of sea surface Chl-a concentration in the Yellow Sea(YS)and the East China Sea(ECS)in 2001-20...Chlorophyll-a(Chl-a)concentration is a primary indicator for marine environmental monitoring.The spatio-temporal variations of sea surface Chl-a concentration in the Yellow Sea(YS)and the East China Sea(ECS)in 2001-2020 were investigated by reconstructing the MODIS Level 3 products with the data interpolation empirical orthogonal function(DINEOF)method.The reconstructed results by interpolating the combined MODIS daily+8-day datasets were found better than those merely by interpolating daily or 8-day data.Chl-a concentration in the YS and the ECS reached its maximum in spring,with blooms occurring,decreased in summer and autumn,and increased in late autumn and early winter.By performing empirical orthogonal function(EOF)decomposition of the reconstructed data fields and correlation analysis with several potential environmental factors,we found that the sea surface temperature(SST)plays a significant role in the seasonal variation of Chl a,especially during spring and summer.The increase of SST in spring and the upper-layer nutrients mixed up during the last winter might favor the occurrence of spring blooms.The high sea surface temperature(SST)throughout the summer would strengthen the vertical stratification and prevent nutrients supply from deep water,resulting in low surface Chl-a concentrations.The sea surface Chl-a concentration in the YS was found decreased significantly from 2012 to 2020,which was possibly related to the Pacific Decadal Oscillation(PDO).展开更多
AIM: Using bacterial, yeast, or mammalian cell expressing a human drug metabolism enzyme would seem good way to study drug metabolism-related problems. Human cytochrome P-450 2C9 ( CYP2 C9) is a polymorphic enzyme res...AIM: Using bacterial, yeast, or mammalian cell expressing a human drug metabolism enzyme would seem good way to study drug metabolism-related problems. Human cytochrome P-450 2C9 ( CYP2 C9) is a polymorphic enzyme responsible for the metabolism of a large number of clinically important drugs. It ranks among the most important drug metabolizing enzymes in humans. In order to provide a sufficient amount of the enzyme for drug metabolic research, the CYP2 C9 eDNA was cloned and expressed stably in CHL cellsMETHODS: After extraction of total RNA from human livertissue, the human CYP2C9 eDNA was amplified withreverse transcription-polymerase chain reaction (RT-PCR),and cloned into cloning vector pGEM-T. The cDNA fragmentwas identified by DNA sequencing and subcloned into amammalian expression vector pREP9. A transgenic cell linewas established by transfecting the recombinant vector ofpREP9-CYP2C9 into CHL cells. The enzyme activity ofCYP2C9 catalyzing oxidation of tolbutamide to hydroxytolbutamide in S9 fraction of the cell was determined by highperformance liquid chromatography(HPLC).RESULTS: The amino acid sequence predicted from theeDNA segment was identical to that of CYP2 C9 * 1, the wildtype CYP2 C9. However, there were two base differences, i.e. 21T > C, 1146C > T, but the encoding amino acidsequence was the same, L7, P382. The S9 fraction of theestablished cell line metabolizes tolbutamide to hydroxytolbutamide; tolbutamide hydroxylass activity was found to be0.465 ± 0.109 μmol@ min-1 . g1 S9 protein or 8.62 ± 2.02 mol@ min 1 ~mol-1 CYP, but was undetectable in parental CHL cell.CONCLUSION: The cDNA of human CYP2C9 was successfullycloned and a cell line of CHL- CYP2C9, efficiently expressingthe protein of CYP2C9, was established.展开更多
The aim of this research was to study the influence of chlorsulfuron residue and cadmium on the enzymatic activity and photosynthetic apparatus of maize(Zea mays L.) plants. Chlorsulfuron and cadmium at 0.001 and 5.0 ...The aim of this research was to study the influence of chlorsulfuron residue and cadmium on the enzymatic activity and photosynthetic apparatus of maize(Zea mays L.) plants. Chlorsulfuron and cadmium at 0.001 and 5.0 mg kg–1, respectively, were mixed and applied to soil prior to planting. The levels of chlorsulfuron-and cadmium-induced stress to plants were estimated by growth, chlorophyll content, lipid peroxide content, enzyme activities, and major fluorescence parameters of chlorophyll(revealed by the fluorescence imaging system Fluor Cam). Chlorsulfuron negatively affected the chlorophyll content, photochemical efficiency of photosystem II in the dark-adapted state, the maximum efficiency of photosystem II, photochemical quenching coefficient, and steady-state fluorescence decline ratio in the leaves of maize seedlings. However, cadmium did not produce noticeable changes. Plants that were exposed to both chlorsulfuron and cadmium showed an obvious increase in the steady-state fluorescence decline ratio. These results implied that the seedlings possessed more resistance to cadmium than to chlorsulfuron and their resistance to chlorsulfuron toxicity was enhanced by the presence of cadmium. The results also suggested that chlorophyll fluorescence imaging reveals overall alterations within the leaves but may not reflect small-scale effects on tissues, as numeric values of specific parameters are averages of the data collected from the whole leaf.展开更多
The South China Sea(SCS), which is the largest marginal sea in the western tropical Pacific, plays an important role in regional climate change. However, the research on the phytoplankton community structure(PCS) resp...The South China Sea(SCS), which is the largest marginal sea in the western tropical Pacific, plays an important role in regional climate change. However, the research on the phytoplankton community structure(PCS) response to the upwelling remains inadequate. In January 2014, the upwelling simulation experiment was performed in the western SCS. Results indicate that the nutrient-rich bottom water not only increased the total Chlorophyll a(Chl a) concentrations, but would potentially altered the PCS. Due to new nutrients added, microphytoplankton had more sensitivity response to nutrient uptake than other phytoplankton groups. The variation of nutrients induced by formation, weakening and disappearance of upwelling resulted in phytoplankton species succession from cyanophyta to bacillariophyta. It may be the leading factor of the changes in PCS and size-fractionated Chl a. The initial concentration of DIP less than 0.1 μmol L-1 could not sustain the phytoplankton growth. This indicates that phosphorus may be the limiting factor in the western SCS.展开更多
Carbon biomass,carbon-to-chlorophyll a ratio(C꞉Chl a),and the growth rate of phytoplankton cells were studied during four seasonal cruises in 2017 and 2018 in Jiaozhou Bay,China.Water samples were collected from 12 st...Carbon biomass,carbon-to-chlorophyll a ratio(C꞉Chl a),and the growth rate of phytoplankton cells were studied during four seasonal cruises in 2017 and 2018 in Jiaozhou Bay,China.Water samples were collected from 12 stations,and phytoplankton carbon biomass(phyto-C)was estimated from microscope-measured cell volumes.The phyto-C ranged from 5.05 to 78.52μg C/L in the bay,and it constituted a mean of 38.16% of the total particulate organic carbon in the bay.High phyto-C values appeared mostly in the northern or northeastern bay.Diatom carbon was predominant during all four cruises.Dinoflagellate carbon contributed much less(<30%)to the total phyto-C,and high values appeared often in the outer bay.The C꞉Chl a of phytoplankton cells varied from 11.50 to 61.45(mean 31.66),and high values appeared in the outer bay during all four seasons.The phyto-C was also used to calculate the intrinsic growth rates of phytoplankton cells in the bay,and phytoplankton growth rates ranged from 0.56 to 1.96/d;the rate was highest in summer(mean 1.79/d),followed by that in fall(mean 1.24/d)and spring(mean 1.17/d),and the rate was lowest in winter(mean 0.77/d).Temperature and silicate concentration were found to be the determining factors of phytoplankton growth rates in the bay.To our knowledge,this study is the first report on phytoplankton carbon biomass and C꞉Chl a based on water samples in Jiaozhou Bay,and it will provide useful information for studies on carbon-based food web calculations and carbon-based ecosystem models in the bay.展开更多
Many previous studies of the impact of oceanic environmental factors on chlorophyll(CHL)in a specific region focused on sea surface temperature(SST),mixed-layer depth(MLD),or wind stress(WS)alone.In this study,relatio...Many previous studies of the impact of oceanic environmental factors on chlorophyll(CHL)in a specific region focused on sea surface temperature(SST),mixed-layer depth(MLD),or wind stress(WS)alone.In this study,relationship between CHL and all those environmental factors(SST,MLD,and WS)in the open ocean was quantified for five regions within the subtropical gyres and the variation trend of 13-year(2003–2015)was analyzed using satellite observations and Argo measurements.The correlation analysis results show that MLD was correlated positively with CHL,SST was correlated negatively with CHL,and the correlation between CHL and WS was either positive or negative.Based on the significance of the correlations,models representing the relationships were established using the multiple linear regression and analyzed,showing that the environmental factors were the major determinants of CHL change.The regression coefficients show that both SST and MLD have remarkable effect on CHL.Our derived models could be used to diagnose the past changes,understand present variability,and predict the future state of CHL changes based on environmental factors,and help us understand the dynamics of CHL variation in the open ocean.展开更多
The contraction of isolated rat and rabbit uteri induced by oxytocin and PGF2α was markedly inhibited by chlorpheniramine (Chl) and astemizolum (Ast) , both of which also decreased the resting tension of uteri, and t...The contraction of isolated rat and rabbit uteri induced by oxytocin and PGF2α was markedly inhibited by chlorpheniramine (Chl) and astemizolum (Ast) , both of which also decreased the resting tension of uteri, and their spontaneous contraction. The inhibitory effects of both drugs were dose-dependent. At high concentrations , Chl 7. 4 × 10-4 mol/L and Ast 10-4 mol/L could counteract the contraction of the uteri induced by Oxy and PGF2α, and their spontaneous contraction as well. They decreased the resting tension to the lower level. The mechanism of their non-special relaxed action on uteri could not be completely explained only by their H1-receptor blocking action. Whether they act by blocking calcium channel or by inhibiting calmodulin (CaM) remains to be further explored.展开更多
Aims: Twelve crude extracts were prepared from different parts of Pluchea sagittalis, Cecropia palmata and Brachiaria brizantha, and their effect on the light reaction of photosynthesis. Study Design: Use of fluoresce...Aims: Twelve crude extracts were prepared from different parts of Pluchea sagittalis, Cecropia palmata and Brachiaria brizantha, and their effect on the light reaction of photosynthesis. Study Design: Use of fluorescence of ChL a (Chlorophyll a) to detect inhibitors of photosynthesis in plant extracts. Place and Duration of Study: Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Departamento de Ciências Exatas e da Terra, Universidade Federal de Sao Paulo (UNIFESP), between July 2015 and January 2016. Methodology: The samples had their effect on the light reaction of photosynthesis studied by Chlorophyll a (Chl a) fluorescence transient by the use of chloroplasts isolated from spinach leaves. As negative controls we used the same amounts of DMSO that have been employed to solubilize the samples, and as positive control we have used 10 μM of the commercial herbicide DCMU (Diuron). Results: The extracts inhibited the photosynthesis, and their inhibition sites were located in the range of electron flow from OEC complex and between P<sub>680</sub> to Q<sub>A</sub> of PS II, and inhibited the photosystem II (PS II) by inducing the appearance of the transient bands K and J. Conclusion: Our results suggest an indicative that the photochemical apparatus probably is failing at the donor and acceptor sides of PSII, causing damage to electron transport during the photosynthesis phenomenon.展开更多
基金Supported by the Fundamental Research Funds for the Central Universities(Nos.202341017,202313024)。
文摘Chlorophyll-a(Chl-a)concentration is a primary indicator for marine environmental monitoring.The spatio-temporal variations of sea surface Chl-a concentration in the Yellow Sea(YS)and the East China Sea(ECS)in 2001-2020 were investigated by reconstructing the MODIS Level 3 products with the data interpolation empirical orthogonal function(DINEOF)method.The reconstructed results by interpolating the combined MODIS daily+8-day datasets were found better than those merely by interpolating daily or 8-day data.Chl-a concentration in the YS and the ECS reached its maximum in spring,with blooms occurring,decreased in summer and autumn,and increased in late autumn and early winter.By performing empirical orthogonal function(EOF)decomposition of the reconstructed data fields and correlation analysis with several potential environmental factors,we found that the sea surface temperature(SST)plays a significant role in the seasonal variation of Chl a,especially during spring and summer.The increase of SST in spring and the upper-layer nutrients mixed up during the last winter might favor the occurrence of spring blooms.The high sea surface temperature(SST)throughout the summer would strengthen the vertical stratification and prevent nutrients supply from deep water,resulting in low surface Chl-a concentrations.The sea surface Chl-a concentration in the YS was found decreased significantly from 2012 to 2020,which was possibly related to the Pacific Decadal Oscillation(PDO).
基金National Natural Science Foundation of China,No.39770868Natural Science Foundation of Zhejiang Province,No.397490
文摘AIM: Using bacterial, yeast, or mammalian cell expressing a human drug metabolism enzyme would seem good way to study drug metabolism-related problems. Human cytochrome P-450 2C9 ( CYP2 C9) is a polymorphic enzyme responsible for the metabolism of a large number of clinically important drugs. It ranks among the most important drug metabolizing enzymes in humans. In order to provide a sufficient amount of the enzyme for drug metabolic research, the CYP2 C9 eDNA was cloned and expressed stably in CHL cellsMETHODS: After extraction of total RNA from human livertissue, the human CYP2C9 eDNA was amplified withreverse transcription-polymerase chain reaction (RT-PCR),and cloned into cloning vector pGEM-T. The cDNA fragmentwas identified by DNA sequencing and subcloned into amammalian expression vector pREP9. A transgenic cell linewas established by transfecting the recombinant vector ofpREP9-CYP2C9 into CHL cells. The enzyme activity ofCYP2C9 catalyzing oxidation of tolbutamide to hydroxytolbutamide in S9 fraction of the cell was determined by highperformance liquid chromatography(HPLC).RESULTS: The amino acid sequence predicted from theeDNA segment was identical to that of CYP2 C9 * 1, the wildtype CYP2 C9. However, there were two base differences, i.e. 21T > C, 1146C > T, but the encoding amino acidsequence was the same, L7, P382. The S9 fraction of theestablished cell line metabolizes tolbutamide to hydroxytolbutamide; tolbutamide hydroxylass activity was found to be0.465 ± 0.109 μmol@ min-1 . g1 S9 protein or 8.62 ± 2.02 mol@ min 1 ~mol-1 CYP, but was undetectable in parental CHL cell.CONCLUSION: The cDNA of human CYP2C9 was successfullycloned and a cell line of CHL- CYP2C9, efficiently expressingthe protein of CYP2C9, was established.
基金supported by grants from the National Natural Science Foundation of China(30740037)the Special Fund for Agro-scientific Research in the Public Interest,China(201103024)the Foundation for Graduate Innovation,Shanxi University,China(011452901009)
文摘The aim of this research was to study the influence of chlorsulfuron residue and cadmium on the enzymatic activity and photosynthetic apparatus of maize(Zea mays L.) plants. Chlorsulfuron and cadmium at 0.001 and 5.0 mg kg–1, respectively, were mixed and applied to soil prior to planting. The levels of chlorsulfuron-and cadmium-induced stress to plants were estimated by growth, chlorophyll content, lipid peroxide content, enzyme activities, and major fluorescence parameters of chlorophyll(revealed by the fluorescence imaging system Fluor Cam). Chlorsulfuron negatively affected the chlorophyll content, photochemical efficiency of photosystem II in the dark-adapted state, the maximum efficiency of photosystem II, photochemical quenching coefficient, and steady-state fluorescence decline ratio in the leaves of maize seedlings. However, cadmium did not produce noticeable changes. Plants that were exposed to both chlorsulfuron and cadmium showed an obvious increase in the steady-state fluorescence decline ratio. These results implied that the seedlings possessed more resistance to cadmium than to chlorsulfuron and their resistance to chlorsulfuron toxicity was enhanced by the presence of cadmium. The results also suggested that chlorophyll fluorescence imaging reveals overall alterations within the leaves but may not reflect small-scale effects on tissues, as numeric values of specific parameters are averages of the data collected from the whole leaf.
基金upport of the National Programme on Global Change and Air-Sea Interaction (GASI-03-01-02-01)
文摘The South China Sea(SCS), which is the largest marginal sea in the western tropical Pacific, plays an important role in regional climate change. However, the research on the phytoplankton community structure(PCS) response to the upwelling remains inadequate. In January 2014, the upwelling simulation experiment was performed in the western SCS. Results indicate that the nutrient-rich bottom water not only increased the total Chlorophyll a(Chl a) concentrations, but would potentially altered the PCS. Due to new nutrients added, microphytoplankton had more sensitivity response to nutrient uptake than other phytoplankton groups. The variation of nutrients induced by formation, weakening and disappearance of upwelling resulted in phytoplankton species succession from cyanophyta to bacillariophyta. It may be the leading factor of the changes in PCS and size-fractionated Chl a. The initial concentration of DIP less than 0.1 μmol L-1 could not sustain the phytoplankton growth. This indicates that phosphorus may be the limiting factor in the western SCS.
基金Supported by the National Natural Science Foundation of China(Nos.31700425,91751202)the External Cooperation Program of Chinese Academy of Sciences(No.133137KYSB20200002)the Taishan Scholars Project to Song SUN。
文摘Carbon biomass,carbon-to-chlorophyll a ratio(C꞉Chl a),and the growth rate of phytoplankton cells were studied during four seasonal cruises in 2017 and 2018 in Jiaozhou Bay,China.Water samples were collected from 12 stations,and phytoplankton carbon biomass(phyto-C)was estimated from microscope-measured cell volumes.The phyto-C ranged from 5.05 to 78.52μg C/L in the bay,and it constituted a mean of 38.16% of the total particulate organic carbon in the bay.High phyto-C values appeared mostly in the northern or northeastern bay.Diatom carbon was predominant during all four cruises.Dinoflagellate carbon contributed much less(<30%)to the total phyto-C,and high values appeared often in the outer bay.The C꞉Chl a of phytoplankton cells varied from 11.50 to 61.45(mean 31.66),and high values appeared in the outer bay during all four seasons.The phyto-C was also used to calculate the intrinsic growth rates of phytoplankton cells in the bay,and phytoplankton growth rates ranged from 0.56 to 1.96/d;the rate was highest in summer(mean 1.79/d),followed by that in fall(mean 1.24/d)and spring(mean 1.17/d),and the rate was lowest in winter(mean 0.77/d).Temperature and silicate concentration were found to be the determining factors of phytoplankton growth rates in the bay.To our knowledge,this study is the first report on phytoplankton carbon biomass and C꞉Chl a based on water samples in Jiaozhou Bay,and it will provide useful information for studies on carbon-based food web calculations and carbon-based ecosystem models in the bay.
基金Supported by the National Key Research and Development Program(Nos.2016YFC1401004,2016YFC1401008)the National Natural Science Foundation for Young Scientists of China(No.41606200)+4 种基金the Qingdao Pilot National Laboratory for Marine Science and Technology(No.2018ASKJ01)the Key R&D Program of Shandong Province,China(No.2019GHY112055)the National Natural Science Foundation of China(Nos.41676168,41376028)the NSFC-Innovation Research Group of Sciences Fund(No.41421005)the NSFC-Shandong Joint Fund for Marine Science Research Centers(No.U1406401)。
文摘Many previous studies of the impact of oceanic environmental factors on chlorophyll(CHL)in a specific region focused on sea surface temperature(SST),mixed-layer depth(MLD),or wind stress(WS)alone.In this study,relationship between CHL and all those environmental factors(SST,MLD,and WS)in the open ocean was quantified for five regions within the subtropical gyres and the variation trend of 13-year(2003–2015)was analyzed using satellite observations and Argo measurements.The correlation analysis results show that MLD was correlated positively with CHL,SST was correlated negatively with CHL,and the correlation between CHL and WS was either positive or negative.Based on the significance of the correlations,models representing the relationships were established using the multiple linear regression and analyzed,showing that the environmental factors were the major determinants of CHL change.The regression coefficients show that both SST and MLD have remarkable effect on CHL.Our derived models could be used to diagnose the past changes,understand present variability,and predict the future state of CHL changes based on environmental factors,and help us understand the dynamics of CHL variation in the open ocean.
文摘The contraction of isolated rat and rabbit uteri induced by oxytocin and PGF2α was markedly inhibited by chlorpheniramine (Chl) and astemizolum (Ast) , both of which also decreased the resting tension of uteri, and their spontaneous contraction. The inhibitory effects of both drugs were dose-dependent. At high concentrations , Chl 7. 4 × 10-4 mol/L and Ast 10-4 mol/L could counteract the contraction of the uteri induced by Oxy and PGF2α, and their spontaneous contraction as well. They decreased the resting tension to the lower level. The mechanism of their non-special relaxed action on uteri could not be completely explained only by their H1-receptor blocking action. Whether they act by blocking calcium channel or by inhibiting calmodulin (CaM) remains to be further explored.
文摘Aims: Twelve crude extracts were prepared from different parts of Pluchea sagittalis, Cecropia palmata and Brachiaria brizantha, and their effect on the light reaction of photosynthesis. Study Design: Use of fluorescence of ChL a (Chlorophyll a) to detect inhibitors of photosynthesis in plant extracts. Place and Duration of Study: Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Departamento de Ciências Exatas e da Terra, Universidade Federal de Sao Paulo (UNIFESP), between July 2015 and January 2016. Methodology: The samples had their effect on the light reaction of photosynthesis studied by Chlorophyll a (Chl a) fluorescence transient by the use of chloroplasts isolated from spinach leaves. As negative controls we used the same amounts of DMSO that have been employed to solubilize the samples, and as positive control we have used 10 μM of the commercial herbicide DCMU (Diuron). Results: The extracts inhibited the photosynthesis, and their inhibition sites were located in the range of electron flow from OEC complex and between P<sub>680</sub> to Q<sub>A</sub> of PS II, and inhibited the photosystem II (PS II) by inducing the appearance of the transient bands K and J. Conclusion: Our results suggest an indicative that the photochemical apparatus probably is failing at the donor and acceptor sides of PSII, causing damage to electron transport during the photosynthesis phenomenon.