Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant...Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant sodium alkyl glucosyl hydroxypropyl sulfonate(APGSHS) and zwitterionic surfactant octadecyl betaine(BS-18) is proposed. The performance of APGSHS/BS-18 mixed surfactant system was evaluated in terms of interfacial tension, emulsification capability, emulsion size and distribution, wettability alteration, temperature-resistance and salt-resistance. The emulsification speed was used to evaluate the emulsification ability of surfactant systems, and the results show that mixed surfactant systems can completely emulsify the crude oil into emulsions droplets even under low energy conditions. Meanwhile,the system exhibits good temperature and salt resistance. Finally, the best oil recovery of 25.45% is achieved for low permeability core by the mixed surfactant system with a total concentration of 0.3 wt%while the molar ratio of APGSHS:BS-18 is 4:6. The current study indicates that the anionic/zwitterionic mixed surfactant system can improve the oil flooding efficiency and is potential candidate for application in low permeability reservoirs.展开更多
Graphitic carbon nitride(g-C_(3)N_(4)) is a fascinating photocatalyst for solar energy utilization in photo-catalysis.Nevertheless,it often suffers from moderate photo-catalytic activity due to its low specific surfac...Graphitic carbon nitride(g-C_(3)N_(4)) is a fascinating photocatalyst for solar energy utilization in photo-catalysis.Nevertheless,it often suffers from moderate photo-catalytic activity due to its low specific surface area and fast recombination rate of photogenerated electrons upon photo-excitation.Herein,we overcome the bottlenecks by constructing a porous g-C_(3)N_(4) nanosheet(PCNS)through a simple thermal oxidation etching method.Benefited from its porous layer structure,the obtained PCNS exhibits large specific surface area,efficient separation of photogenerated charge carriers,as well as high exposure of active sites.As a result,it is robust and universal in visible light-driven dehydrogenation of alcohols in water under oxidant-free condition.Almost quantitative yields(>99%)of various valuable carbonyl compounds were obtained over PCNS,while bulk g-C_(3)N_(4) was far less efficient.Moreover,the photo-catalyst was highly stable and could be facilely recovered from the aqueous system for efficient reuse.The easy preparation and excellent performance made PCNS a promising and competitive photocatalyst for the solar applications.展开更多
Objective： The aim of this study was to explore the characteristics of and preventive management strategies for suicidal inpatients in a general hospital.Methods： A total of 54 suicide victims were drawn from a p...Objective： The aim of this study was to explore the characteristics of and preventive management strategies for suicidal inpatients in a general hospital.Methods： A total of 54 suicide victims were drawn from a patient safety adverse event network reporting system during hospitalization in a general hospital from November 2008 to January 2017.Results： Subjects who committed suicide in the general hospital were women and those who suffered from malignant neoplasms during general hospital treatment. Furthermore, most of the patients who committed suicide used more violent suicide methods. The most common and lethal means was jumping from heights at the windowsill.Conclusions： It is concluded that management straties for suicide prevention can be provided from the aspects of patients, medical staff and the hospital environment. It is not only urgent but also feasible to reduce the suicide rate of inpatients and further improve hospital safety management.展开更多
Nasopharyngeal carcinoma(NPC)is a malignant epithelial tumor ubiquitously associated with the Epstein-Barr virus(EBV),which is highly prevalent in South China,Southeast Asia,and North Africa.Despite being a highly rad...Nasopharyngeal carcinoma(NPC)is a malignant epithelial tumor ubiquitously associated with the Epstein-Barr virus(EBV),which is highly prevalent in South China,Southeast Asia,and North Africa.Despite being a highly radio-sensitive and treatable cancer,a majority of NPC patients are diagnosed in their advanced stage,and locoregional and distant relapses following definitive treatment contribute largely to cancer-specific mortality among these patients.Given that EBV-driven NPC is the predominant variant seen in endemic regions,various EBV detection methods have been developed and are utilized in screening,prognostication,and post-treatment surveillance of NPC patients.While the Immunoglobulin A(IgA)serology assay is the most extensively studied EBV detection method,the detection of plasma EBV DNA released during replication or cellular apoptosis has shown superior outcomes in endemic population screening,prognostication,and detection of distant relapse.Furthermore,there is emerging evidence on the use of circulating tumor cells,microRNAs,DNA hypermethylation,and combination assays in various clinical scenarios.Herein,this paper provides a comprehensive overview of the relevant studies using various EBV detection techniques in the management of NPC.Specifically,the recent advances,clinical evidence,and challenges associated with the clinical application of EBV liquid biopsies in population screening,prognostication,and surveillance of NPC are presented.展开更多
Endogenous stress and exogenous toxicants(chemicals and UV light) alter genetic information either directly or indirectly through the production of reactive oxygen species(ROS), thereby driving genomic instability in ...Endogenous stress and exogenous toxicants(chemicals and UV light) alter genetic information either directly or indirectly through the production of reactive oxygen species(ROS), thereby driving genomic instability in cells and promoting tumorigenesis. All living cells try to faithfully preserve and transmit their genomic information from one generation to the next using DNA repair mechanisms to repair oxidative DNA damage to prevent cancer or premature aging. Oxidative DNA damage comprises a mixture of DNA lesions including base damage, DNA single strand breaks(SSBs), and DNA double strand breaks(DSBs). This review summarizes some of the studies on DNA damage response at a defined genome locus that are performed by students from the Tsinghua University School of Medicine and the School of Medicine of Central South University(Xiangya Hospital) at the University of Pittsburgh School of Medicine. A summary of their work highlights the continuous contribution of the students to a particular research program and exemplifies the achievements of this China-U.S. collaborative training program.展开更多
Intramolecular acid-base cooperative catalysis is a powerful strategy to promote the nucleophilic additions in synthetic chemistry,since both substrates and nucleophiles can be activated simultaneously,yielding a lowe...Intramolecular acid-base cooperative catalysis is a powerful strategy to promote the nucleophilic additions in synthetic chemistry,since both substrates and nucleophiles can be activated simultaneously,yielding a lower energy reaction pathway.However,the systems often suffer from catalyst quenching due to the mutual neutralization of acid/base sites.Herein,we doped the boron(B)atoms in the tri-s-triazine ring of graphite-like carbon nitride(g-C_(3)N_(4))framework,to develop the acid-base cooperative catalyst for nucleophilic addition.Characterization results demonstrated a foam-like hierarchical porous structure,as well as the coexistence of Lewis acid and base sites in the as-synthesized samples.As a result,the B-doped g-C_(3)N_(4) acted as the efficient acidbase cooperative catalysts,significantly promoting the Knoevenagel condensation whose key step involves in nucleophilic addition.A wide range of α,β-unsaturated carbonyl compounds with remarkably high yields(>90%)was achieved even within 1 h in water,whereas the acid-free or base-free counterpart was far less efficient.In addition,the bifunctional catalysts exhibited excellent reusability with simple treatment.The novel B-doped g-C_(3)N_(4) catalytic system offers several advantages,such as operational simplicity,mild reaction conditions,high efficiency,and facile reuse of catalyst.All these advantages make it a benign protocol from the sustainability point of view,and inspired us to design the other bifunctional cooperative catalysts for a wide range of sustainable industrial applications.展开更多
基金financially supported by National Natural Science Foundation of China(No.22302229)Beijing Municipal Excellent Talent Training Funds Youth Advanced Individual Project(No.2018000020124G163)。
文摘Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant sodium alkyl glucosyl hydroxypropyl sulfonate(APGSHS) and zwitterionic surfactant octadecyl betaine(BS-18) is proposed. The performance of APGSHS/BS-18 mixed surfactant system was evaluated in terms of interfacial tension, emulsification capability, emulsion size and distribution, wettability alteration, temperature-resistance and salt-resistance. The emulsification speed was used to evaluate the emulsification ability of surfactant systems, and the results show that mixed surfactant systems can completely emulsify the crude oil into emulsions droplets even under low energy conditions. Meanwhile,the system exhibits good temperature and salt resistance. Finally, the best oil recovery of 25.45% is achieved for low permeability core by the mixed surfactant system with a total concentration of 0.3 wt%while the molar ratio of APGSHS:BS-18 is 4:6. The current study indicates that the anionic/zwitterionic mixed surfactant system can improve the oil flooding efficiency and is potential candidate for application in low permeability reservoirs.
基金support by the Shenzhen-Hong Kong-Macao Science and Technology Project(Category C)sponsored by the Science Technology and Innovation Committee of Shenzhen Municipality(SGDX20201103093003017)Shenzhen Key Basic Research Project(JCYJ20200109114827177)Hong Kong RGC General Research Fund(CityU 11216421).
基金financial support provided by the National Natural Science Foundation of China(21676078)the Natural Science Foundation of Hunan Province for Distinguished Young Scholar(2016JJ1013)+1 种基金Scientific Research Fund of Hunan Provincial Education Department(19A323)Science and Technology Planning Project of Hunan Province(2018TP1017)。
文摘Graphitic carbon nitride(g-C_(3)N_(4)) is a fascinating photocatalyst for solar energy utilization in photo-catalysis.Nevertheless,it often suffers from moderate photo-catalytic activity due to its low specific surface area and fast recombination rate of photogenerated electrons upon photo-excitation.Herein,we overcome the bottlenecks by constructing a porous g-C_(3)N_(4) nanosheet(PCNS)through a simple thermal oxidation etching method.Benefited from its porous layer structure,the obtained PCNS exhibits large specific surface area,efficient separation of photogenerated charge carriers,as well as high exposure of active sites.As a result,it is robust and universal in visible light-driven dehydrogenation of alcohols in water under oxidant-free condition.Almost quantitative yields(>99%)of various valuable carbonyl compounds were obtained over PCNS,while bulk g-C_(3)N_(4) was far less efficient.Moreover,the photo-catalyst was highly stable and could be facilely recovered from the aqueous system for efficient reuse.The easy preparation and excellent performance made PCNS a promising and competitive photocatalyst for the solar applications.
基金supported by the National Natural Science Foundation of China(No.71673100)
文摘Objective： The aim of this study was to explore the characteristics of and preventive management strategies for suicidal inpatients in a general hospital.Methods： A total of 54 suicide victims were drawn from a patient safety adverse event network reporting system during hospitalization in a general hospital from November 2008 to January 2017.Results： Subjects who committed suicide in the general hospital were women and those who suffered from malignant neoplasms during general hospital treatment. Furthermore, most of the patients who committed suicide used more violent suicide methods. The most common and lethal means was jumping from heights at the windowsill.Conclusions： It is concluded that management straties for suicide prevention can be provided from the aspects of patients, medical staff and the hospital environment. It is not only urgent but also feasible to reduce the suicide rate of inpatients and further improve hospital safety management.
文摘Nasopharyngeal carcinoma(NPC)is a malignant epithelial tumor ubiquitously associated with the Epstein-Barr virus(EBV),which is highly prevalent in South China,Southeast Asia,and North Africa.Despite being a highly radio-sensitive and treatable cancer,a majority of NPC patients are diagnosed in their advanced stage,and locoregional and distant relapses following definitive treatment contribute largely to cancer-specific mortality among these patients.Given that EBV-driven NPC is the predominant variant seen in endemic regions,various EBV detection methods have been developed and are utilized in screening,prognostication,and post-treatment surveillance of NPC patients.While the Immunoglobulin A(IgA)serology assay is the most extensively studied EBV detection method,the detection of plasma EBV DNA released during replication or cellular apoptosis has shown superior outcomes in endemic population screening,prognostication,and detection of distant relapse.Furthermore,there is emerging evidence on the use of circulating tumor cells,microRNAs,DNA hypermethylation,and combination assays in various clinical scenarios.Herein,this paper provides a comprehensive overview of the relevant studies using various EBV detection techniques in the management of NPC.Specifically,the recent advances,clinical evidence,and challenges associated with the clinical application of EBV liquid biopsies in population screening,prognostication,and surveillance of NPC are presented.
基金supported in part by grants from the National Institutes of Health GM118833 to LLproject used the UPMC Hillman Cancer Center Cytometry Facility, supported in part by National Institutes of Health P30CA047904
文摘Endogenous stress and exogenous toxicants(chemicals and UV light) alter genetic information either directly or indirectly through the production of reactive oxygen species(ROS), thereby driving genomic instability in cells and promoting tumorigenesis. All living cells try to faithfully preserve and transmit their genomic information from one generation to the next using DNA repair mechanisms to repair oxidative DNA damage to prevent cancer or premature aging. Oxidative DNA damage comprises a mixture of DNA lesions including base damage, DNA single strand breaks(SSBs), and DNA double strand breaks(DSBs). This review summarizes some of the studies on DNA damage response at a defined genome locus that are performed by students from the Tsinghua University School of Medicine and the School of Medicine of Central South University(Xiangya Hospital) at the University of Pittsburgh School of Medicine. A summary of their work highlights the continuous contribution of the students to a particular research program and exemplifies the achievements of this China-U.S. collaborative training program.
基金The authors are grateful for the financial support provided by the National Natural Science foundation of China(21676078)the Scientific Research fund of Hunan Provincial Education Department(19A323)the Key Laboratory of the Assembly and Application of Organic functional Molecules of Hunan Province.
文摘Intramolecular acid-base cooperative catalysis is a powerful strategy to promote the nucleophilic additions in synthetic chemistry,since both substrates and nucleophiles can be activated simultaneously,yielding a lower energy reaction pathway.However,the systems often suffer from catalyst quenching due to the mutual neutralization of acid/base sites.Herein,we doped the boron(B)atoms in the tri-s-triazine ring of graphite-like carbon nitride(g-C_(3)N_(4))framework,to develop the acid-base cooperative catalyst for nucleophilic addition.Characterization results demonstrated a foam-like hierarchical porous structure,as well as the coexistence of Lewis acid and base sites in the as-synthesized samples.As a result,the B-doped g-C_(3)N_(4) acted as the efficient acidbase cooperative catalysts,significantly promoting the Knoevenagel condensation whose key step involves in nucleophilic addition.A wide range of α,β-unsaturated carbonyl compounds with remarkably high yields(>90%)was achieved even within 1 h in water,whereas the acid-free or base-free counterpart was far less efficient.In addition,the bifunctional catalysts exhibited excellent reusability with simple treatment.The novel B-doped g-C_(3)N_(4) catalytic system offers several advantages,such as operational simplicity,mild reaction conditions,high efficiency,and facile reuse of catalyst.All these advantages make it a benign protocol from the sustainability point of view,and inspired us to design the other bifunctional cooperative catalysts for a wide range of sustainable industrial applications.
