The consensus of the automotive industry and traffic management authorities is that autonomous vehicles must follow the same traffic laws as human drivers.Using formal or digital methods,natural language traffic rules...The consensus of the automotive industry and traffic management authorities is that autonomous vehicles must follow the same traffic laws as human drivers.Using formal or digital methods,natural language traffic rules can be translated into machine language and used by autonomous vehicles.In this paper,a translation flow is designed.Beyond the translation,a deeper examination is required,because the semantics of natural languages are rich and complex,and frequently contain hidden assumptions.The issue of how to ensure that digital rules are accurate and consistent with the original intent of the traffic rules they represent is both significant and unresolved.In response,we propose a method of formal verification that combines equivalence verification with model checking.Reasonable and reassuring digital traffic rules can be obtained by utilizing the proposed traffic rule digitization flow and verification method.In addition,we offer a number of simulation applications that employ digital traffic rules to assess vehicle violations.The experimental findings indicate that our digital rules utilizing metric temporal logic(MTL)can be easily incorporated into simulation platforms and autonomous driving systems(ADS).展开更多
The conversion of CO_(2) into fuels and valuable chemicals is one of the central topics to combat climate change and meet the growing demand for renewable energy.Herein,we show that the formate dehydrogenase from Clos...The conversion of CO_(2) into fuels and valuable chemicals is one of the central topics to combat climate change and meet the growing demand for renewable energy.Herein,we show that the formate dehydrogenase from Clostridium ljungdahlii(ClFDH)adsorbed on electrodes displays clear characteristic voltammetric signals that can be assigned to the reduction and oxidation potential of the[4Fe-4S]^(2+/+)cluster under nonturnover conditions.Upon adding substrates,the signals transform into a specific redox center that engages in catalytic electron transport.ClFDH catalyzes rapid and efficient reversible interconversion between CO_(2) and formate in the presence of substrates.The turnover frequency of electrochemical CO_(2) reduction is determined as 1210 s^(-1) at 25℃ and pH 7.0,which can be further enhanced up to 1786 s^(-1) at 50℃.The Faradaic efficiency at−0.6 V(vs.standard hydrogen electrode)is recorded as 99.3%in a 2-h reaction.Inhibition experiments and theoretical modeling disclose interesting pathways for CO_(2) entry,formate exit,and OCN−competition,suggesting an oxidation-state-dependent binding mechanism of catalysis.Our results provide a different perspective for understanding the catalytic mechanism of FDH and original insights into the design of synthetic catalysts.展开更多
Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catal...Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catalysts for the hydrogen economy, the poor oxygen tolerance and low yield of hydrogenases largely hinder their practical application. In these years, the enigmas surrounding hydrogenases regarding their structures, oxygen tolerance, mechanisms for catalysis, redox intermediates, and proton-coupled electron transfer schemes have been gradually elucidated;the schemes, which can well couple hydrogenases with other highly efficient(in)organic and biological catalysts to build novel reactors and drive valuable reactions, make it possible for hydrogenases to find their niches. To see how scientists put efforts to tackle this issue and design novel reactors in the fields where hydrogenases play crucial roles, in this review,recent advances were summarized, including different strategies for protecting enzyme molecules from oxygen, enzyme-based assembling systems for H_(2) evolution in the photoelectronic catalysis, enzymatic biofuel cells for H_(2) utilization and storage and the efficient electricity-hydrogen-carbohydrate cycle for high-purity hydrogen and biofuel automobiles. Limitations and future perspectives of hydrogenasebased applications in H_(2) production and utilization with great impact are discussed. In addition, this review also provides a new perspective on the use of biohydrogen in healthcare beyond energy.展开更多
The pathophysiology of osteoarthritis(OA)is multifactorial,with the primary risk factors being obesity,age,environmental variables,and genetic predisposition.The available evidence suggests that genetic diversity does...The pathophysiology of osteoarthritis(OA)is multifactorial,with the primary risk factors being obesity,age,environmental variables,and genetic predisposition.The available evidence suggests that genetic diversity does not adequately account for all clinical characteristics and heterogeneity of OA.Genetics has emerged as a nascent and crucial area of research in OA.The epigenetic module presents a potential link between genetic and environmental risk factors and the susceptibility and pathogenesis of OA.As a critical epigenetic alteration,DNA methylation has been shown to have an important role in the etiology of OA and is a viable biomarker for predicting disease progression and medication response,as shown in this research.This review aims to update knowledge in the field of DNA methylation associated with OA to better identify the essential features of OA subtypes and pathological conditions,hence accelerating individualized treatment and precision medicine.展开更多
On the basis of data mining,systematic pharmacology,molecular docking,and experiment validation,the oxidative-inflammatory molecular targets of Coicis Semen in the therapy of osteoarthritis(OA)were explored.Methods:Th...On the basis of data mining,systematic pharmacology,molecular docking,and experiment validation,the oxidative-inflammatory molecular targets of Coicis Semen in the therapy of osteoarthritis(OA)were explored.Methods:The association rule analysis was effectively applied to highlight the correlation between Coicis Semen and oxidative inflammation indices.The random walk model was subsequently used to evaluate the clinical efficacy of Coicis Semen.Network pharmacology was used to predict network targets.The binding affinity of the active ingredient in Coicis Semen to the key target of OA was also successfully predicted.Results:Coicis Semen showed a significant reduction in oxidative-inflammatory indicators of OA.A total of 108 promising targets were predicted for the 24 bioactive compounds in Coicis Semen.Eight target genes were considered core target genes.The enrichment analysis predicts that Coicis Semen may activate the interleukin(IL)-17,mitogen-activated protein kinase(MAPK),and nuclear factor kappa B(NF-kappa B)signaling pathways.Molecular docking demonstrated that stigmasterol,2-monoolein,sitosterol,and sitosterol alpha1 had free binding energies to oxidative and inflammatory targets(MAPK1,Estrogen Receptor 1[ESR1],and Peroxisome Proliferator-Activated Receptor Alpha[PPARA]).Both clinical trials and in vitro cell experiments revealed that Coicis Semen could increase ESR1 and PPAR-αlevels while decreasing MAPK1 levels.Conclusions:Coicis Semen has a remarkable anti-OA effect.Precisely,the major components of Coicis Semen,including stigmasterol,sitosterol alpha1,sitosterol,and 2-monoolein,specifically inhibit MAPK1,ESR1,and PPARA to reduce the inflammatory response and oxidative damage in OA.展开更多
BACKGROUND Acupuncture promotes the recovery of gastrointestinal function and provides analgesia after major abdominal surgery.The effects of transcutaneous electrical acupoint stimulation(TEAS)remain unclear.AIM To e...BACKGROUND Acupuncture promotes the recovery of gastrointestinal function and provides analgesia after major abdominal surgery.The effects of transcutaneous electrical acupoint stimulation(TEAS)remain unclear.AIM To explore the potential effects of TEAS on the recovery of gastrointestinal function after gastrectomy and colorectal resection.METHODS Patients scheduled for gastrectomy or colorectal resection were randomized at a 2:3:3:2 ratio to receive:(1)TEAS at maximum tolerable current for 30 min immediately prior to anesthesia induction and for the entire duration of surgery,plus two 30-min daily sessions for 3 consecutive days after surgery(perioperative TEAS group);(2)Preoperative and intraoperative TEAS only;(3)Preoperative and postoperative TEAS only;or(4)Sham stimulation.The primary outcome was the time from the end of surgery to the first bowel sound.RESULTS In total,441 patients were randomized;405 patients(58.4±10.2 years of age;247 males)received the planned surgery.The time to the first bowel sounds did not differ among the four groups(P=0.90;log-rank test).On postoperative day 1,the rest pain scores differed significantly among the four groups(P=0.04;Kruskal–Wallis test).Post hoc comparison using the Bonferroni test showed lower pain scores in the perioperative TEAS group(1.4±1.2)than in the sham sti-mulation group(1.7±1.1;P=0.04).Surgical complications did not differ among the four groups.CONCLUSION TEAS provided analgesic effects in adult patients undergoing major abdominal surgery,and it can be added to clinical practice as a means of accelerating postoperative rehabilitation of these patients.展开更多
Increasing levels of pollution within water bodies can cause eutrophication and an associated rapid growth in and reproduction of phytoplankton. Although most frequently occurring in bodies of water such as lakes and ...Increasing levels of pollution within water bodies can cause eutrophication and an associated rapid growth in and reproduction of phytoplankton. Although most frequently occurring in bodies of water such as lakes and dams, in recent years an increasing number of river systems in China have suffered serious algal blooms. The community structure of phytoplankton may differ, however, dependent on the hydrodynamic conditions and nutrient levels within the water body. The field investigation results obtained from a stagnant river in Suzhou City and Taihu Lake, China, showed that in water with higher concentrations of nitrogen and phosphorus, Chlorophyta became the predominant species and in water with lower concentrations of nitrogen and phosphorus, Cyanobacteria became the predominant species. Growth experiments with competitive species, Microcystis aeruginosa Kutz and Scenedesmus quadricauda （Turp.）, were conducted at three different nutrient levels. The biomass of algae in pure and mixed cultures was measured under conditions of different N/P ratios at oligotrophic, eutrophic and hypertrophic nutrient levels. The results indicated that the most suitable state for the growth and reproduction of M. aeruginosa and S. quadricauda were eutrophic conditions in both pure and mixed cultures. Under competition, however, the lower medium nutrient levels favoured M. aeruginosa, while the higher medium nutrient levels better suited S. quadricauda. Under similar hydrodynamic conditions, the community structure of phytoplankton in the water body was determined by the dominant species in competition for nutrients.展开更多
BACKGROUND Hypoxemia due to respiratory depression and airway obstruction during upper gastrointestinal endoscopy with sedation is a common concern.The Wei nasal jet tube(WNJT)is a new nasopharyngeal airway with the a...BACKGROUND Hypoxemia due to respiratory depression and airway obstruction during upper gastrointestinal endoscopy with sedation is a common concern.The Wei nasal jet tube(WNJT)is a new nasopharyngeal airway with the ability to provide supraglottic jet ventilation and oxygen insufflation via its built-in wall channel.The available evidence indicates that with a low oxygen flow,compared with nasal cannula,the WNJT does not decrease the occurrence of hypoxemia during upper gastrointestinal endoscopy with propofol sedation.To date,there has been no study assessing the performance of WNJT for supplemental oxygen during upper gastrointestinal endoscopy with sedation when a moderate oxygen flow is used.AIM To determine whether the WNJT performs better than the nasal prongs for the prevention of hypoxemia during gastroscopy with propofol mono-sedation when a moderate oxygen flow is provided in patients with a normal body mass index.METHODS This study was performed in 291 patients undergoing elective gastroscopy with propofol mono-sedation.Patients were randomized into one of two groups to receive either the WNJT(WNJT group,n=147)or the nasal cannula(nasal cannula group,n=144)for supplemental oxygen at a 5-L/min flow during gastroscopy.The lowest SpO2 during gastroscopy was recorded.The primary endpoint was the incidence of hypoxemia or severe hypoxemia during gastroscopy.RESULTS The total incidence of hypoxemia and severe hypoxemia during gastroscopy was significantly decreased in the WNJT group compared with the nasal cannula group(P=0.000).The lowest median SpO2 during gastroscopy was significantly higher(98%;interquartile range,97-99)in the WNJT group than in the nasal cannula group(96%;interquartile range,93-98).Epistaxis by device insertion in the WNJT group occurred in 7 patients but stopped naturally without any treatment.The two groups were comparable in terms of the satisfaction of physicians,anesthetists and patients.CONCLUSION With a moderate oxygen flow,the WNJT is more effective for the prevention of hypoxemia during gastroscopy with propofol mono-sedation compared with nasal prongs,but causing slight epistaxis in a few patients.展开更多
BACKGROUND Hypoxemia is a common complication in obese patients during gastroscopy with sedation.The Wei nasal jet tube(WNJT)is a new special nasopharyngeal airway with the ability to provide supraglottic jet ventilat...BACKGROUND Hypoxemia is a common complication in obese patients during gastroscopy with sedation.The Wei nasal jet tube(WNJT)is a new special nasopharyngeal airway with the ability to provide supraglottic jet ventilation and oxygen insufflation via its built-in wall channels.The aim of this study was to compare the efficacy and safety of the WNJT vs a nasal cannula for supplemental oxygen during gastroscopy with propofol mono-sedation in obese patients.AIM To compare the efficacy and safety of the WNJT vs a nasal cannula for supplemental oxygen during gastroscopy with propofol mono-sedation in obese patients.METHODS A total of 103 obese patients with a body mass index of 30 kg/m2 or more undergoing elective gastroscopy under propofol mono-sedation were randomly assigned to receive supplemental oxygen at 5 L/min through either a WNJT(WNJT group,n=51)or a nasal cannula(nasal cannula group,n=52).The lowest pulse oxygen saturation(SpO2)and mild and severe hypoxemia during gastroscopy were recorded.The primary outcome was the incidence of hypoxemia.RESULTS The lowest SpO2 during gastroscopy with propofol mono-sedation was significantly increased in the WNJT group compared with the nasal cannula group.The incidence of mild hypoxemia and total incidence of hypoxemia were significantly lower in the WNJT group than in the nasal cannula group.Other than a higher incidence of epistaxis in the WNJT group,the occurrence of adverse events was similar between the devices.While neither device demonstrated a statistically significant difference in satisfaction among patients,the WNJT did result in improved satisfaction among anesthetists and physicians.CONCLUSION During gastroscopy with propofol mono-sedation in obese patients,the WNJT,when compared with a nasal cannula for supplemental oxygen,can significantly reduce the occurrence of hypoxemia and improve both arterial oxygenation and satisfaction among anesthetists and physicians.The use of the WNJT may,however,lead to epistaxis in a few patients.In view of this clinically acceptable risk-benefit ratio,the WNJT may be recommended as an alternative tool for supplemental oxygen for the prevention of hypoxemia during gastroscopy with propofol mono-sedation in obese patients.展开更多
Catalyst recovery is one of the most important aspects that restrict the application of Ti O_2 photocatalyst. In order to reduce restrictions and improve the photocatalytic efficiency, a hierarchical porous Ti O_2 mon...Catalyst recovery is one of the most important aspects that restrict the application of Ti O_2 photocatalyst. In order to reduce restrictions and improve the photocatalytic efficiency, a hierarchical porous Ti O_2 monolith(PTM) with well-defined macroporous and homogeneous mesoporous structure was prepared by using a sol-gel phase separation method. P123 was used as the mesoporous template and graphene oxide was applied to increase the activity and integrity of the monolithic Ti O_2. According to scanning electron microscopy and the Barrett-Joyner-Halenda measurements, PTM_3 is mainly composed of 10 nm anatase crystallines with3.6 nm mesopores and 2-8 μm macropores. Further characterization suggests carbon and nitrogen have been maintained in the PTM during calcinations so as to induce the visible light activity. The PTM with 0.07 wt%graphene oxide dosage shows high efficiency for methyl orange(MO) decolorization under both full spectrum and visible light irradiation(λ >400 nm). Besides, the monolith remains intact and has good photocatalytic stability after four cyclic experiments.展开更多
文摘The consensus of the automotive industry and traffic management authorities is that autonomous vehicles must follow the same traffic laws as human drivers.Using formal or digital methods,natural language traffic rules can be translated into machine language and used by autonomous vehicles.In this paper,a translation flow is designed.Beyond the translation,a deeper examination is required,because the semantics of natural languages are rich and complex,and frequently contain hidden assumptions.The issue of how to ensure that digital rules are accurate and consistent with the original intent of the traffic rules they represent is both significant and unresolved.In response,we propose a method of formal verification that combines equivalence verification with model checking.Reasonable and reassuring digital traffic rules can be obtained by utilizing the proposed traffic rule digitization flow and verification method.In addition,we offer a number of simulation applications that employ digital traffic rules to assess vehicle violations.The experimental findings indicate that our digital rules utilizing metric temporal logic(MTL)can be easily incorporated into simulation platforms and autonomous driving systems(ADS).
基金support from the National Key Research and Development Program of China (No.2020YFA0907300)the National Natural Science Foundation of China (No.22077069)+1 种基金the Natural Science Foundation of Tianjin (19JCZDJC33400)the Fundamental Research Funds for the Central Universities,Nankai University (63201111).
文摘The conversion of CO_(2) into fuels and valuable chemicals is one of the central topics to combat climate change and meet the growing demand for renewable energy.Herein,we show that the formate dehydrogenase from Clostridium ljungdahlii(ClFDH)adsorbed on electrodes displays clear characteristic voltammetric signals that can be assigned to the reduction and oxidation potential of the[4Fe-4S]^(2+/+)cluster under nonturnover conditions.Upon adding substrates,the signals transform into a specific redox center that engages in catalytic electron transport.ClFDH catalyzes rapid and efficient reversible interconversion between CO_(2) and formate in the presence of substrates.The turnover frequency of electrochemical CO_(2) reduction is determined as 1210 s^(-1) at 25℃ and pH 7.0,which can be further enhanced up to 1786 s^(-1) at 50℃.The Faradaic efficiency at−0.6 V(vs.standard hydrogen electrode)is recorded as 99.3%in a 2-h reaction.Inhibition experiments and theoretical modeling disclose interesting pathways for CO_(2) entry,formate exit,and OCN−competition,suggesting an oxidation-state-dependent binding mechanism of catalysis.Our results provide a different perspective for understanding the catalytic mechanism of FDH and original insights into the design of synthetic catalysts.
基金supported by the National Key Research and Development Program of China (Nos. 2020YFA0907300, 2020YFA0907800)the National Natural Science Foundation of China (No. 22077069)+1 种基金the Natural Science Foundation of Tianjin (Nos. 19JCZDJC33400 and 21JCYBJC00310)the Fundamental Research Funds for the Central Universities, Nankai University (No. 63201111)。
文摘Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catalysts for the hydrogen economy, the poor oxygen tolerance and low yield of hydrogenases largely hinder their practical application. In these years, the enigmas surrounding hydrogenases regarding their structures, oxygen tolerance, mechanisms for catalysis, redox intermediates, and proton-coupled electron transfer schemes have been gradually elucidated;the schemes, which can well couple hydrogenases with other highly efficient(in)organic and biological catalysts to build novel reactors and drive valuable reactions, make it possible for hydrogenases to find their niches. To see how scientists put efforts to tackle this issue and design novel reactors in the fields where hydrogenases play crucial roles, in this review,recent advances were summarized, including different strategies for protecting enzyme molecules from oxygen, enzyme-based assembling systems for H_(2) evolution in the photoelectronic catalysis, enzymatic biofuel cells for H_(2) utilization and storage and the efficient electricity-hydrogen-carbohydrate cycle for high-purity hydrogen and biofuel automobiles. Limitations and future perspectives of hydrogenasebased applications in H_(2) production and utilization with great impact are discussed. In addition, this review also provides a new perspective on the use of biohydrogen in healthcare beyond energy.
基金supported by the Anhui Famous Traditional Chinese Medicine Liu Jian Studio Construction Project(Traditional Chinese Medicine Development Secret[2018]No.11)the Ministry of Science and Technology National Key Research and Development Program Chinese Medicine Modernization Research Key Project(No.2018YFC1705204)+1 种基金Anhui Province Traditional Chinese Medicine Leading Talent Project(Traditional Chinese Medicine Development Secret[2018]No.23)the Anhui Key Research and Development Program Foreign Science and Technology Cooperation Project(No.201904b11020011).
文摘The pathophysiology of osteoarthritis(OA)is multifactorial,with the primary risk factors being obesity,age,environmental variables,and genetic predisposition.The available evidence suggests that genetic diversity does not adequately account for all clinical characteristics and heterogeneity of OA.Genetics has emerged as a nascent and crucial area of research in OA.The epigenetic module presents a potential link between genetic and environmental risk factors and the susceptibility and pathogenesis of OA.As a critical epigenetic alteration,DNA methylation has been shown to have an important role in the etiology of OA and is a viable biomarker for predicting disease progression and medication response,as shown in this research.This review aims to update knowledge in the field of DNA methylation associated with OA to better identify the essential features of OA subtypes and pathological conditions,hence accelerating individualized treatment and precision medicine.
基金supported by the Anhui Famous Traditional Chinese Medicine Liu Jian Studio Construction Project(Traditional Chinese Medicine Development Secret[2018]No.11)the Ministry of Science and Technology National Key Research and Development Program Chinese Medicine Modernization Research Key Project(No.2018YFC1705204)+2 种基金Anhui Province Traditional Chinese Medicine Leading Talent Project(Traditional Chinese Medicine Development Secret[2018]No.23)the Anhui key Research and Development Program Foreign Science and Technology Cooperation Project(No.201904b11020011)the Anhui Provincial Education Department Project(No.2022AH050449).
文摘On the basis of data mining,systematic pharmacology,molecular docking,and experiment validation,the oxidative-inflammatory molecular targets of Coicis Semen in the therapy of osteoarthritis(OA)were explored.Methods:The association rule analysis was effectively applied to highlight the correlation between Coicis Semen and oxidative inflammation indices.The random walk model was subsequently used to evaluate the clinical efficacy of Coicis Semen.Network pharmacology was used to predict network targets.The binding affinity of the active ingredient in Coicis Semen to the key target of OA was also successfully predicted.Results:Coicis Semen showed a significant reduction in oxidative-inflammatory indicators of OA.A total of 108 promising targets were predicted for the 24 bioactive compounds in Coicis Semen.Eight target genes were considered core target genes.The enrichment analysis predicts that Coicis Semen may activate the interleukin(IL)-17,mitogen-activated protein kinase(MAPK),and nuclear factor kappa B(NF-kappa B)signaling pathways.Molecular docking demonstrated that stigmasterol,2-monoolein,sitosterol,and sitosterol alpha1 had free binding energies to oxidative and inflammatory targets(MAPK1,Estrogen Receptor 1[ESR1],and Peroxisome Proliferator-Activated Receptor Alpha[PPARA]).Both clinical trials and in vitro cell experiments revealed that Coicis Semen could increase ESR1 and PPAR-αlevels while decreasing MAPK1 levels.Conclusions:Coicis Semen has a remarkable anti-OA effect.Precisely,the major components of Coicis Semen,including stigmasterol,sitosterol alpha1,sitosterol,and 2-monoolein,specifically inhibit MAPK1,ESR1,and PPARA to reduce the inflammatory response and oxidative damage in OA.
基金National Basic Research Program of China(Project 973)from The Ministry of Science and Technology of the People's Republic of China,No.2013CB531900。
文摘BACKGROUND Acupuncture promotes the recovery of gastrointestinal function and provides analgesia after major abdominal surgery.The effects of transcutaneous electrical acupoint stimulation(TEAS)remain unclear.AIM To explore the potential effects of TEAS on the recovery of gastrointestinal function after gastrectomy and colorectal resection.METHODS Patients scheduled for gastrectomy or colorectal resection were randomized at a 2:3:3:2 ratio to receive:(1)TEAS at maximum tolerable current for 30 min immediately prior to anesthesia induction and for the entire duration of surgery,plus two 30-min daily sessions for 3 consecutive days after surgery(perioperative TEAS group);(2)Preoperative and intraoperative TEAS only;(3)Preoperative and postoperative TEAS only;or(4)Sham stimulation.The primary outcome was the time from the end of surgery to the first bowel sound.RESULTS In total,441 patients were randomized;405 patients(58.4±10.2 years of age;247 males)received the planned surgery.The time to the first bowel sounds did not differ among the four groups(P=0.90;log-rank test).On postoperative day 1,the rest pain scores differed significantly among the four groups(P=0.04;Kruskal–Wallis test).Post hoc comparison using the Bonferroni test showed lower pain scores in the perioperative TEAS group(1.4±1.2)than in the sham sti-mulation group(1.7±1.1;P=0.04).Surgical complications did not differ among the four groups.CONCLUSION TEAS provided analgesic effects in adult patients undergoing major abdominal surgery,and it can be added to clinical practice as a means of accelerating postoperative rehabilitation of these patients.
基金supported by the Natural Science Foundation of Jiangsu Province (No.BK2006710) the Hi-Tech Research and Development Program (863) of China (No:2003AA601100)
文摘Increasing levels of pollution within water bodies can cause eutrophication and an associated rapid growth in and reproduction of phytoplankton. Although most frequently occurring in bodies of water such as lakes and dams, in recent years an increasing number of river systems in China have suffered serious algal blooms. The community structure of phytoplankton may differ, however, dependent on the hydrodynamic conditions and nutrient levels within the water body. The field investigation results obtained from a stagnant river in Suzhou City and Taihu Lake, China, showed that in water with higher concentrations of nitrogen and phosphorus, Chlorophyta became the predominant species and in water with lower concentrations of nitrogen and phosphorus, Cyanobacteria became the predominant species. Growth experiments with competitive species, Microcystis aeruginosa Kutz and Scenedesmus quadricauda （Turp.）, were conducted at three different nutrient levels. The biomass of algae in pure and mixed cultures was measured under conditions of different N/P ratios at oligotrophic, eutrophic and hypertrophic nutrient levels. The results indicated that the most suitable state for the growth and reproduction of M. aeruginosa and S. quadricauda were eutrophic conditions in both pure and mixed cultures. Under competition, however, the lower medium nutrient levels favoured M. aeruginosa, while the higher medium nutrient levels better suited S. quadricauda. Under similar hydrodynamic conditions, the community structure of phytoplankton in the water body was determined by the dominant species in competition for nutrients.
基金Supported by“Renfu”Research Fund by Chinese Society of Digestive Endoscopy,No.CSDE012017120006.
文摘BACKGROUND Hypoxemia due to respiratory depression and airway obstruction during upper gastrointestinal endoscopy with sedation is a common concern.The Wei nasal jet tube(WNJT)is a new nasopharyngeal airway with the ability to provide supraglottic jet ventilation and oxygen insufflation via its built-in wall channel.The available evidence indicates that with a low oxygen flow,compared with nasal cannula,the WNJT does not decrease the occurrence of hypoxemia during upper gastrointestinal endoscopy with propofol sedation.To date,there has been no study assessing the performance of WNJT for supplemental oxygen during upper gastrointestinal endoscopy with sedation when a moderate oxygen flow is used.AIM To determine whether the WNJT performs better than the nasal prongs for the prevention of hypoxemia during gastroscopy with propofol mono-sedation when a moderate oxygen flow is provided in patients with a normal body mass index.METHODS This study was performed in 291 patients undergoing elective gastroscopy with propofol mono-sedation.Patients were randomized into one of two groups to receive either the WNJT(WNJT group,n=147)or the nasal cannula(nasal cannula group,n=144)for supplemental oxygen at a 5-L/min flow during gastroscopy.The lowest SpO2 during gastroscopy was recorded.The primary endpoint was the incidence of hypoxemia or severe hypoxemia during gastroscopy.RESULTS The total incidence of hypoxemia and severe hypoxemia during gastroscopy was significantly decreased in the WNJT group compared with the nasal cannula group(P=0.000).The lowest median SpO2 during gastroscopy was significantly higher(98%;interquartile range,97-99)in the WNJT group than in the nasal cannula group(96%;interquartile range,93-98).Epistaxis by device insertion in the WNJT group occurred in 7 patients but stopped naturally without any treatment.The two groups were comparable in terms of the satisfaction of physicians,anesthetists and patients.CONCLUSION With a moderate oxygen flow,the WNJT is more effective for the prevention of hypoxemia during gastroscopy with propofol mono-sedation compared with nasal prongs,but causing slight epistaxis in a few patients.
基金Supported by“Renfu”Research Fund by Chinese Society of Digestive Endoscopy,No.CSDE022020090001.
文摘BACKGROUND Hypoxemia is a common complication in obese patients during gastroscopy with sedation.The Wei nasal jet tube(WNJT)is a new special nasopharyngeal airway with the ability to provide supraglottic jet ventilation and oxygen insufflation via its built-in wall channels.The aim of this study was to compare the efficacy and safety of the WNJT vs a nasal cannula for supplemental oxygen during gastroscopy with propofol mono-sedation in obese patients.AIM To compare the efficacy and safety of the WNJT vs a nasal cannula for supplemental oxygen during gastroscopy with propofol mono-sedation in obese patients.METHODS A total of 103 obese patients with a body mass index of 30 kg/m2 or more undergoing elective gastroscopy under propofol mono-sedation were randomly assigned to receive supplemental oxygen at 5 L/min through either a WNJT(WNJT group,n=51)or a nasal cannula(nasal cannula group,n=52).The lowest pulse oxygen saturation(SpO2)and mild and severe hypoxemia during gastroscopy were recorded.The primary outcome was the incidence of hypoxemia.RESULTS The lowest SpO2 during gastroscopy with propofol mono-sedation was significantly increased in the WNJT group compared with the nasal cannula group.The incidence of mild hypoxemia and total incidence of hypoxemia were significantly lower in the WNJT group than in the nasal cannula group.Other than a higher incidence of epistaxis in the WNJT group,the occurrence of adverse events was similar between the devices.While neither device demonstrated a statistically significant difference in satisfaction among patients,the WNJT did result in improved satisfaction among anesthetists and physicians.CONCLUSION During gastroscopy with propofol mono-sedation in obese patients,the WNJT,when compared with a nasal cannula for supplemental oxygen,can significantly reduce the occurrence of hypoxemia and improve both arterial oxygenation and satisfaction among anesthetists and physicians.The use of the WNJT may,however,lead to epistaxis in a few patients.In view of this clinically acceptable risk-benefit ratio,the WNJT may be recommended as an alternative tool for supplemental oxygen for the prevention of hypoxemia during gastroscopy with propofol mono-sedation in obese patients.
基金financially supported by the National Natural Science Foundation of China (No. 20907031)
文摘Catalyst recovery is one of the most important aspects that restrict the application of Ti O_2 photocatalyst. In order to reduce restrictions and improve the photocatalytic efficiency, a hierarchical porous Ti O_2 monolith(PTM) with well-defined macroporous and homogeneous mesoporous structure was prepared by using a sol-gel phase separation method. P123 was used as the mesoporous template and graphene oxide was applied to increase the activity and integrity of the monolithic Ti O_2. According to scanning electron microscopy and the Barrett-Joyner-Halenda measurements, PTM_3 is mainly composed of 10 nm anatase crystallines with3.6 nm mesopores and 2-8 μm macropores. Further characterization suggests carbon and nitrogen have been maintained in the PTM during calcinations so as to induce the visible light activity. The PTM with 0.07 wt%graphene oxide dosage shows high efficiency for methyl orange(MO) decolorization under both full spectrum and visible light irradiation(λ >400 nm). Besides, the monolith remains intact and has good photocatalytic stability after four cyclic experiments.
