Due to the unique fluorescence characteristics,superstructures from self-assembly of semiconductor nanoparticles have become essential components of material and chemical science,and thus it has broad application pote...Due to the unique fluorescence characteristics,superstructures from self-assembly of semiconductor nanoparticles have become essential components of material and chemical science,and thus it has broad application potential in displays,single-photon source,sensing,biological tagging and emerging quantum technologies.Superstructure refers to an artificial functional architecture whose length scale is between the quantum scale and the macroscale.When solely treating this complicated stage fitted from less complicated pieces together(basic nanoparticles)and pile speculation on speculation,we must understand the fundamental questions,that is,what the hierarchy or specialization of function is at the stage.The uniqueness of this stage is not the collection of basic nanoparticles,but the behavior that emerges on fluorescence-basically a new type of behavior.Under the angle of view,this study reviews the advances in the fluorescence of individual semiconductor nanoparticles,inter-nanoparticles coupling and thus emergent fluorescence behaviors of assemblies.We also try to present the methodology for seeking emergent behaviors on fluorescence.展开更多
Mycobacterium tuberculosis, a Gram-positive bacterium of great clinical relevance, is a lethal pathogen owing to its complex physiological characteristics and development of drug resistance. Several molecular genetic ...Mycobacterium tuberculosis, a Gram-positive bacterium of great clinical relevance, is a lethal pathogen owing to its complex physiological characteristics and development of drug resistance. Several molecular genetic tools have been developed in the past few decades to study this microorganism. These tools have been instrumental in understanding how M. tuberculosis became a successful pathogen. Advanced molecular genetic tools have played a significant role in exploring the complex pathways involved in M. tuberculosis pathogenesis. Here, we review various molecular genetic tools used in the study of M. tuberculosis. Further, we discuss the applications of clustered regularly interspaced short palindromic repeat interference（CRISPRi）, a novel technology recently applied in M. tuberculosis research to study target gene functions. Finally, prospective outcomes of the applications of molecular techniques in the field of M. tuberculosis genetic research are also discussed.展开更多
Buruli ulcer(BU),caused by Mycobacterium ulcerans,is currently treated with rifampin estreptomycin or rifampineclarithromycin daily for 8 weeks recommended by World Health Organization(WHO).These options are lengthy w...Buruli ulcer(BU),caused by Mycobacterium ulcerans,is currently treated with rifampin estreptomycin or rifampineclarithromycin daily for 8 weeks recommended by World Health Organization(WHO).These options are lengthy with severe side effects.A new anti-tuberculosis drug,TB47,targeting QcrB in cytochrome bc1:aa3 complex is being developed in China.TB47-containing regimens were evaluated in a well-established murine model using an autoluminescent M.ulcerans strain.Highlevel TB47-resistant spontaneous M.ulcerans mutants were selected and their qcrB genes were sequenced.The in vivo activities of TB47 against both low-level and high-level TB47-resistant mutants were tested in BU murine model.Here,we show that TB47-containing oral 3-drug regimens can completely cure BU in 2 weeks for daily use or in 3 weeks given twice per week(6 doses in total).All high-level TB47-resistant mutants could only be selected using the low-level mutants which were still sensitive to TB47 in mice.This is the first report of double mutations in QcrB in mycobacteria.In summary,TB47-containing regimens have promise to cure BU highly effectively and prevent the emergence of drug resistance.Novel QcrB mutations found here may guide the potential clinical molecular diagnosis of resistance and the discovery of new drugs against the high-level resistant mutants.展开更多
Tin-lead(Sn-Pb)alloyed perovskites with tunable bandgaps hold great potential for constructing highly efficient single-junction and tandem photovoltaic devices.However,the efficiency and stability of Sn-Pb perovskite ...Tin-lead(Sn-Pb)alloyed perovskites with tunable bandgaps hold great potential for constructing highly efficient single-junction and tandem photovoltaic devices.However,the efficiency and stability of Sn-Pb perovskite solar cells(PSCs)are greatly hampered by severe nonradiative recombination due to the easy oxidation of Sn(II).In this work,we report the construction of mixed dimensional two-dimensional(2D)Dion–Jacobson(DJ)and three-dimensional(3D)perovskites to improve the efficiency and stability of Sn-Pb alloyed PSCs.Introducing a small amount of 1,4-butanediammonium diiodide as spacer cations of DJ perovskites into precursor,the prepared mixed dimensional Sn-Pb alloyed perovskites exhibit reduced trap-state density due to the passivation of 2D DJ perovskites.As a result,nonradiative charge recombination is greatly suppressed.The prepared Sn-Pb alloyed PSCs based on 2D-DJ/3D heterojunction deliver a power conversion efficiency of 19.02%with an impressive fill factor of 80%.As well,improved device stability is realized due to the presence of DJ perovskites which serves as a protection barrier against oxidation and water invasion.展开更多
A 2 × 2 optical waveguide coupler at 850 nm based on the multimode interference （MMI） structure with the polysilsesquioxanes liquid series （PSQ-Ls） polymer material and the imprint technique is presented. The...A 2 × 2 optical waveguide coupler at 850 nm based on the multimode interference （MMI） structure with the polysilsesquioxanes liquid series （PSQ-Ls） polymer material and the imprint technique is presented. The influence of the structural parameters, such as the single mode condition, the waveguide spacing of input/output ports, and the width and length of the multimode waveguide, on the optical splitting performance including the excess loss and the uniformity is simulated by the beam propagation method. By inserting a taper section of isosceles trapezoid between the single mode and multimode waveguides, the optimized structural parameters for low excess loss and high uniformity are obtained with the excess loss of -0.040 dB and the uniformity of-0.007 dB. The effect of the structure deviations induced during the imprint process on the optical splitting performance at different residual layer thicknesses is also investigated. The analysis results provide useful instructions for the waveguide device fabrication.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21925405 and 201874005)the National Key Research and Development Program of China(No.2018YFA0208800)Chinese Academy of Sciences(Nos.XDA23030106 and YJKYYQ20180044).
文摘Due to the unique fluorescence characteristics,superstructures from self-assembly of semiconductor nanoparticles have become essential components of material and chemical science,and thus it has broad application potential in displays,single-photon source,sensing,biological tagging and emerging quantum technologies.Superstructure refers to an artificial functional architecture whose length scale is between the quantum scale and the macroscale.When solely treating this complicated stage fitted from less complicated pieces together(basic nanoparticles)and pile speculation on speculation,we must understand the fundamental questions,that is,what the hierarchy or specialization of function is at the stage.The uniqueness of this stage is not the collection of basic nanoparticles,but the behavior that emerges on fluorescence-basically a new type of behavior.Under the angle of view,this study reviews the advances in the fluorescence of individual semiconductor nanoparticles,inter-nanoparticles coupling and thus emergent fluorescence behaviors of assemblies.We also try to present the methodology for seeking emergent behaviors on fluorescence.
基金supported by the National Mega-project of China for Innovative Drugs(2018ZX09721001-003-003)for Main Infectious Diseases(2017ZX10302301-003-002)+7 种基金the National Natural Science Foundation of China(No.81572037)the grants of Chinese Academy of Sciences(154144KYSB20150045,YJKYYQ20170036,KFZD-SW-207)the Public Research and Capacity Building Project of Guangdong Province(2017A020212004)partially supported by Guangzhou Municipal Industry and Research Collaborative Innovation Program(201508020248,201604020019)the Key Project(SKLRD2016ZJ003)from the State Key Lab of Respiratory Disease,Guangzhou Institute of Respiratory Diseases,First Affiliated Hospital of Guangzhou Medical UniversityT.Z.received support“Science and Technology Innovation Leader of Guangdong Province(2016TX03R095)”CAS-TWAS President's Ph D Fellowship Program(to C.C.and M.M.I.)UCAS Ph D Fellowship Program(to H.M.A.H.and J.M.)for International Students
文摘Mycobacterium tuberculosis, a Gram-positive bacterium of great clinical relevance, is a lethal pathogen owing to its complex physiological characteristics and development of drug resistance. Several molecular genetic tools have been developed in the past few decades to study this microorganism. These tools have been instrumental in understanding how M. tuberculosis became a successful pathogen. Advanced molecular genetic tools have played a significant role in exploring the complex pathways involved in M. tuberculosis pathogenesis. Here, we review various molecular genetic tools used in the study of M. tuberculosis. Further, we discuss the applications of clustered regularly interspaced short palindromic repeat interference（CRISPRi）, a novel technology recently applied in M. tuberculosis research to study target gene functions. Finally, prospective outcomes of the applications of molecular techniques in the field of M. tuberculosis genetic research are also discussed.
基金supported by the National Mega-Project of China for Innovative Drugs(2019ZX09721001-003-003)the Chinese Academy of Sciences grant(154144KYSB20190005,China)+2 种基金the Key-Area Research and Development Program of Guangdong Province(2019B110233003,China)the Special Funds for Economic Development of Marine Economy of Guangdong Province(GDME-2018C003,China)partially by the Grants(SKLRDOP-201919 and SKLRD-Z-202016)from the State Key Laboratory of Respiratory Disease,Guangzhou Institute of Respiratory Diseases,First Affiliated Hospital of Guangzhou Medical University,Guangzhou,China。
文摘Buruli ulcer(BU),caused by Mycobacterium ulcerans,is currently treated with rifampin estreptomycin or rifampineclarithromycin daily for 8 weeks recommended by World Health Organization(WHO).These options are lengthy with severe side effects.A new anti-tuberculosis drug,TB47,targeting QcrB in cytochrome bc1:aa3 complex is being developed in China.TB47-containing regimens were evaluated in a well-established murine model using an autoluminescent M.ulcerans strain.Highlevel TB47-resistant spontaneous M.ulcerans mutants were selected and their qcrB genes were sequenced.The in vivo activities of TB47 against both low-level and high-level TB47-resistant mutants were tested in BU murine model.Here,we show that TB47-containing oral 3-drug regimens can completely cure BU in 2 weeks for daily use or in 3 weeks given twice per week(6 doses in total).All high-level TB47-resistant mutants could only be selected using the low-level mutants which were still sensitive to TB47 in mice.This is the first report of double mutations in QcrB in mycobacteria.In summary,TB47-containing regimens have promise to cure BU highly effectively and prevent the emergence of drug resistance.Novel QcrB mutations found here may guide the potential clinical molecular diagnosis of resistance and the discovery of new drugs against the high-level resistant mutants.
基金supported by the National Natural Science Foundation of China(No.62174069)Natural Science Foundation of Guangdong Province(No.2020A1515010853).
文摘Tin-lead(Sn-Pb)alloyed perovskites with tunable bandgaps hold great potential for constructing highly efficient single-junction and tandem photovoltaic devices.However,the efficiency and stability of Sn-Pb perovskite solar cells(PSCs)are greatly hampered by severe nonradiative recombination due to the easy oxidation of Sn(II).In this work,we report the construction of mixed dimensional two-dimensional(2D)Dion–Jacobson(DJ)and three-dimensional(3D)perovskites to improve the efficiency and stability of Sn-Pb alloyed PSCs.Introducing a small amount of 1,4-butanediammonium diiodide as spacer cations of DJ perovskites into precursor,the prepared mixed dimensional Sn-Pb alloyed perovskites exhibit reduced trap-state density due to the passivation of 2D DJ perovskites.As a result,nonradiative charge recombination is greatly suppressed.The prepared Sn-Pb alloyed PSCs based on 2D-DJ/3D heterojunction deliver a power conversion efficiency of 19.02%with an impressive fill factor of 80%.As well,improved device stability is realized due to the presence of DJ perovskites which serves as a protection barrier against oxidation and water invasion.
基金This work was supported in part by the International Science ＆ Technology Cooperation Program of China （No. 2014DFG32590）, National Natural Science Foundation of China （No.61077015, 61307040）, National R＆D Program （No.2012AA040406）, Natural Science Foundation of Liaoning Province （No. 2014020002）, Opening Project of Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques （No. 2013ADL04）, and Fundamental Research Funds for the Central Universities （DUT 13JB01, DUT 15ZD231, and DUT2015TD47）.
文摘A 2 × 2 optical waveguide coupler at 850 nm based on the multimode interference （MMI） structure with the polysilsesquioxanes liquid series （PSQ-Ls） polymer material and the imprint technique is presented. The influence of the structural parameters, such as the single mode condition, the waveguide spacing of input/output ports, and the width and length of the multimode waveguide, on the optical splitting performance including the excess loss and the uniformity is simulated by the beam propagation method. By inserting a taper section of isosceles trapezoid between the single mode and multimode waveguides, the optimized structural parameters for low excess loss and high uniformity are obtained with the excess loss of -0.040 dB and the uniformity of-0.007 dB. The effect of the structure deviations induced during the imprint process on the optical splitting performance at different residual layer thicknesses is also investigated. The analysis results provide useful instructions for the waveguide device fabrication.
