On-surface Ullmann-type reaction,or the dehalogenated coupling,is arguably the most pivotal reaction in on-surface synthesis for the fabrications of carbon nanostructures.Hitherto,the vast majority of works rely on ac...On-surface Ullmann-type reaction,or the dehalogenated coupling,is arguably the most pivotal reaction in on-surface synthesis for the fabrications of carbon nanostructures.Hitherto,the vast majority of works rely on activating the C-Br bond of aryl bromide which has a moderate bond dissociation energy.The C-Cl bond of aryl chloride has a higher dissociation energy and requires much higher thermal energy to break the bond.In this study,we have explored the on-surface photo-induced dechlorination and achieved the activation of three distinct aryl chlorines on the Au(111)surface with mild temperatures.This work enriches our understanding of on-surface photo-induced reactions and highlights the potential of photochemistry in realizing unconventional reactions.展开更多
Real-time quantitative polymerase chain reaction(qPCR)has gained popularity as a technique to detect and quantify a specific group of target microorganisms from various environmental samples including soil,water,sedim...Real-time quantitative polymerase chain reaction(qPCR)has gained popularity as a technique to detect and quantify a specific group of target microorganisms from various environmental samples including soil,water,sediments,and sludge.Although qPCR is a very useful technique for nucleic acid quantification,accurately quantifying the target microbial group strongly depends on the quality of the primer and probe used.Many aspects of conducting qPCR assays have become increasingly routine and automated;however,one of the most important aspects,designing and selecting primer and probe sets,is often a somewhat arcane process.In many cases,failed or non-specific amplification can be attributed to improperly designed primer-probe sets.This paper is intended to provide guidelines and general principles for designing group-specific primers and probes for qPCR assays.We demonstrate the effectiveness of these guidelines by reviewing the use of qPCR to study anaerobic processes and biologic nutrient removal processes.qPCR assays using group-specific primers and probes designed with this method,have been used to successfully quantify 16S ribosomal Ribonucleic Acid(16S rRNA)gene copy numbers from target methanogenic and ammoniaoxidizing bacteria in various laboratory-and full-scale biologic processes.Researchers with a good command of primer and probe design can use qPCR as a valuable tool to study biodiversity and to develop more efficient control strategies for biologic processes.展开更多
We report a turn-on fluorescent probe for H2S through a cascade reaction using a new trap group 4- （bromomethyl）benzoate, based on excited-state intramolecular proton transfer （ESIPT） sensing mechanism. The probe ...We report a turn-on fluorescent probe for H2S through a cascade reaction using a new trap group 4- （bromomethyl）benzoate, based on excited-state intramolecular proton transfer （ESIPT） sensing mechanism. The probe showed good selectivity and high sensitivity towards H2S and it was capable of detecting and imaging H2S in living HeLa cells, indicating its potential biological applications.展开更多
Pathogenic bacteria pose a global threat to public health and attract considerable attention in terms of food safety.Rapid and highly sensitive strategies for detecting pathogenic bacteria must be urgently developed t...Pathogenic bacteria pose a global threat to public health and attract considerable attention in terms of food safety.Rapid and highly sensitive strategies for detecting pathogenic bacteria must be urgently developed to ensure food safety and public health.Microchips offer significant advantages for pathogenic bacterial detection in terms of speed and sensitivity compared with those of traditional techniques.Microfluidic devices,in particular,have attracted significant attention for the detection of pathogenic bacteria owing to their ease of operation,high throughput,cost-effectiveness,and high sensitivity.This review summarizes representative articles on the analysis of pathogenic bacteria using microchip-based systems.A detailed and comprehensive overview of microchip-based techniques for the detection of pathogenic bacteria is presented herein,and their advantages and disadvantages are discussed to compare their applications.The accomplishments and shortcomings of these microchips have been highlighted,and the direction of development and prospects of the analysis of pathogenic bacteria have been examined.The content of this review is anticipated to provide constructive suggestions for further development of highly effective and advanced microchip-based strategies for detecting pathogenic bacteria.展开更多
Selective detection of multiple analytes in a compact design with dual-modality and theranostic features presents great challenges. Herein, we wish to report a coumarin-thiazolidine masked D-penicillamine based dual-m...Selective detection of multiple analytes in a compact design with dual-modality and theranostic features presents great challenges. Herein, we wish to report a coumarin-thiazolidine masked D-penicillamine based dual-modality fluorescent probe COU-DPA-1 for selective detection, differentiation, and detoxification of multiple heavy metal ions(Ag^(+), Hg^(2+), Cu^(2+)). The probe shows divergent fluorescence(FL)/circular dichroism(CD) responses via divergent bond-cleavage cascade reactions(metal ion promoted C-S cleavage and hydrolysis at two distinctive cleavage sites): FL “turn-off” and CD “turn-on” for Ag+(no hydrolysis), FL “turn-on” and CD “turn-off” for Hg^(+)(imine hydrolysis), and FL “self-threshold ratiometric” and CD “turn-off” for excess Cu^(2+)(lactone and imine hydrolysis), providing the first example of a fluorescence/CD dual-modality probe for multiple species with complimentary responses. Moreover, the bond-cleavage cascade reactions also lead to the formation of D-penicillamine heavy metal ion complexes for potential detoxification treatments.展开更多
No molecular ion peak from the Electron Impact lonization of eight co-hydroxyalkyltriphenyl phosphonium bromides(Ph3P+(CH2)nOHBr-,n=2-6,8-10)can be found,except a part of some relative powerful fragment ions can be ob...No molecular ion peak from the Electron Impact lonization of eight co-hydroxyalkyltriphenyl phosphonium bromides(Ph3P+(CH2)nOHBr-,n=2-6,8-10)can be found,except a part of some relative powerful fragment ions can be observed only.Each compound forms a very characteristic ion(O=PPbj-1)+ at m/z 277 through hydroxyl rearrangement reaction.The intensity of this ion is closely related with the size of the carbon chain of hydroxyalkyl and with temperature of ion source and temperature of sample probe.The above rearrangement reaction and the reaction to form ion at m/z 262 take place simultaneously,thus leading to strong competition.At n=2,ion at m/z 277 is the most powerful and becomes continuously the base peak.At n=3 and n=4,the intensity of ion at m/z 262 reaches the maximum,and is always the base peak,and the relative abundance of m/z 277 is only around 2%.At n=5,6,8,9,10,m/z 277 becomes base peak when the temperature of probe is below 300℃.But,when the temperature increases from 300℃to 350℃,m/z 262 suddenly becomes the base peak,which is not in direct proportional relation with the size of carbon chain.It is proved by MIKES and accurate mass that ion at m/z 277 produces a fragment ion(O=PPh2-2)+ at m/z 199 with the loss of the neutral benzene molecule.展开更多
基金supported by National Natural Science Foundation of China(Nos.22072086,22302120)。
文摘On-surface Ullmann-type reaction,or the dehalogenated coupling,is arguably the most pivotal reaction in on-surface synthesis for the fabrications of carbon nanostructures.Hitherto,the vast majority of works rely on activating the C-Br bond of aryl bromide which has a moderate bond dissociation energy.The C-Cl bond of aryl chloride has a higher dissociation energy and requires much higher thermal energy to break the bond.In this study,we have explored the on-surface photo-induced dechlorination and achieved the activation of three distinct aryl chlorines on the Au(111)surface with mild temperatures.This work enriches our understanding of on-surface photo-induced reactions and highlights the potential of photochemistry in realizing unconventional reactions.
基金This work was also supported by the Korea Research Foundation Grant funded by the Korean Government(MOEHRD)by New&Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant(No.20101T100100366).
文摘Real-time quantitative polymerase chain reaction(qPCR)has gained popularity as a technique to detect and quantify a specific group of target microorganisms from various environmental samples including soil,water,sediments,and sludge.Although qPCR is a very useful technique for nucleic acid quantification,accurately quantifying the target microbial group strongly depends on the quality of the primer and probe used.Many aspects of conducting qPCR assays have become increasingly routine and automated;however,one of the most important aspects,designing and selecting primer and probe sets,is often a somewhat arcane process.In many cases,failed or non-specific amplification can be attributed to improperly designed primer-probe sets.This paper is intended to provide guidelines and general principles for designing group-specific primers and probes for qPCR assays.We demonstrate the effectiveness of these guidelines by reviewing the use of qPCR to study anaerobic processes and biologic nutrient removal processes.qPCR assays using group-specific primers and probes designed with this method,have been used to successfully quantify 16S ribosomal Ribonucleic Acid(16S rRNA)gene copy numbers from target methanogenic and ammoniaoxidizing bacteria in various laboratory-and full-scale biologic processes.Researchers with a good command of primer and probe design can use qPCR as a valuable tool to study biodiversity and to develop more efficient control strategies for biologic processes.
基金financially supported by the 973 Program (No.2013CB933800)National Natural Science Foundation of China (Nos.21525206,21402216,21272243)the Fundamental Research Funds for the Central Universities and Beijing Municipal Commission of Education
文摘We report a turn-on fluorescent probe for H2S through a cascade reaction using a new trap group 4- （bromomethyl）benzoate, based on excited-state intramolecular proton transfer （ESIPT） sensing mechanism. The probe showed good selectivity and high sensitivity towards H2S and it was capable of detecting and imaging H2S in living HeLa cells, indicating its potential biological applications.
基金the National Natural Science Foundation of China(No.21575042)Project funded by China Postdoctoral Science Foundation(No.2019M663577)+2 种基金Applied Basic Research Programs of Yunnan Science and Technology Department(No.2018FH001–102)Talent Introduction Project of Kunming University(No.YJL18011)Innovative Practical Scientific Research Project of Kunming University(No.HXHG1805)。
文摘Pathogenic bacteria pose a global threat to public health and attract considerable attention in terms of food safety.Rapid and highly sensitive strategies for detecting pathogenic bacteria must be urgently developed to ensure food safety and public health.Microchips offer significant advantages for pathogenic bacterial detection in terms of speed and sensitivity compared with those of traditional techniques.Microfluidic devices,in particular,have attracted significant attention for the detection of pathogenic bacteria owing to their ease of operation,high throughput,cost-effectiveness,and high sensitivity.This review summarizes representative articles on the analysis of pathogenic bacteria using microchip-based systems.A detailed and comprehensive overview of microchip-based techniques for the detection of pathogenic bacteria is presented herein,and their advantages and disadvantages are discussed to compare their applications.The accomplishments and shortcomings of these microchips have been highlighted,and the direction of development and prospects of the analysis of pathogenic bacteria have been examined.The content of this review is anticipated to provide constructive suggestions for further development of highly effective and advanced microchip-based strategies for detecting pathogenic bacteria.
基金supported by the National Natural Science Foundation of China (Nos. 21577037 and 21738002)the State Key Laboratory of Bioreactor Engineering, Shanghai Natural Science Fund (No. 20ZR1414700)+2 种基金Shanghai Sailing Program (No. 19YF1412500)Natural Science Basic Research Program of Shaanxi (No. 2019JQ-924)Key Breeding Program by Collaborative Innovation Center of Green Manufacturing Technology for Traditional Chinese Medicine in Shaanxi Province (No. 2019XT-1-03)。
文摘Selective detection of multiple analytes in a compact design with dual-modality and theranostic features presents great challenges. Herein, we wish to report a coumarin-thiazolidine masked D-penicillamine based dual-modality fluorescent probe COU-DPA-1 for selective detection, differentiation, and detoxification of multiple heavy metal ions(Ag^(+), Hg^(2+), Cu^(2+)). The probe shows divergent fluorescence(FL)/circular dichroism(CD) responses via divergent bond-cleavage cascade reactions(metal ion promoted C-S cleavage and hydrolysis at two distinctive cleavage sites): FL “turn-off” and CD “turn-on” for Ag+(no hydrolysis), FL “turn-on” and CD “turn-off” for Hg^(+)(imine hydrolysis), and FL “self-threshold ratiometric” and CD “turn-off” for excess Cu^(2+)(lactone and imine hydrolysis), providing the first example of a fluorescence/CD dual-modality probe for multiple species with complimentary responses. Moreover, the bond-cleavage cascade reactions also lead to the formation of D-penicillamine heavy metal ion complexes for potential detoxification treatments.
基金Project (No. 29775004) supported by the National Natural Science Foundation of China
文摘No molecular ion peak from the Electron Impact lonization of eight co-hydroxyalkyltriphenyl phosphonium bromides(Ph3P+(CH2)nOHBr-,n=2-6,8-10)can be found,except a part of some relative powerful fragment ions can be observed only.Each compound forms a very characteristic ion(O=PPbj-1)+ at m/z 277 through hydroxyl rearrangement reaction.The intensity of this ion is closely related with the size of the carbon chain of hydroxyalkyl and with temperature of ion source and temperature of sample probe.The above rearrangement reaction and the reaction to form ion at m/z 262 take place simultaneously,thus leading to strong competition.At n=2,ion at m/z 277 is the most powerful and becomes continuously the base peak.At n=3 and n=4,the intensity of ion at m/z 262 reaches the maximum,and is always the base peak,and the relative abundance of m/z 277 is only around 2%.At n=5,6,8,9,10,m/z 277 becomes base peak when the temperature of probe is below 300℃.But,when the temperature increases from 300℃to 350℃,m/z 262 suddenly becomes the base peak,which is not in direct proportional relation with the size of carbon chain.It is proved by MIKES and accurate mass that ion at m/z 277 produces a fragment ion(O=PPh2-2)+ at m/z 199 with the loss of the neutral benzene molecule.
