The expression ofβ-lactamase,particularly metallo-β-lactamase(MBL)in bacteria has caused significant resistance to clinically importantβ-lactam antibiotics,including life-saving carbapenems.Antimicrobial peptides(A...The expression ofβ-lactamase,particularly metallo-β-lactamase(MBL)in bacteria has caused significant resistance to clinically importantβ-lactam antibiotics,including life-saving carbapenems.Antimicrobial peptides(AMPs)have emerged as promising therapeutic agents to combat antibiotic resistance.However,the cytotoxic AMPs has been one of the major concerns for their applications in clinical practice.Herein,we report a novel cephalosporin-caged AMP,which shows significantly reduced cytotoxicity,hemolytic activity,and antibacterial activity but turns highly active against bacteria upon specific hydrolysis by the antimicrobial resistance-causativeβ-lactamase.Further investigations demonstrate thisβ-lactamaseactivatable AMP selectively inactivates resistant bacterial pathogens over susceptible bacteria.This strategy should be applicable to other AMPs as a potential solution for the treatment of infectious diseases caused byβ-lactamase-expressing pathogenic bacteria.展开更多
The high quality single crystals of Yb5Co4Ge10 have been grown by the indium metal flux method and characterized by means of single crystal X-ray diffraction data. Yb5Co4Ge10 crystallizes in the Sc5Co4Si10 structure t...The high quality single crystals of Yb5Co4Ge10 have been grown by the indium metal flux method and characterized by means of single crystal X-ray diffraction data. Yb5Co4Ge10 crystallizes in the Sc5Co4Si10 structure type, tetragonal space group P4/mbm and lattice constants are a = b = 12.6369(18) ? and c = 4.1378(8) ?. Crystal structure of Yb5Co4Ge10 composed of three-dimensional [Co4Ge12] network having five, six and eight membered rings. The three non-equivalent Yb atoms are sandwiched in three different channels created by the [Co4Ge12] network. Based on the bond length analysis from the crystallographic information, we confirmed that Yb1 and Yb2 atoms are in the trivalent magnetic state and Yb3 is in the divalent non-magnetic state.展开更多
Sustainable thermoelectric materials open an avenue of emission-free as well as fast-responding recycling of energy in terms of heat to electricity.The efficiency(η)of such conversion is primarily guided by the dimen...Sustainable thermoelectric materials open an avenue of emission-free as well as fast-responding recycling of energy in terms of heat to electricity.The efficiency(η)of such conversion is primarily guided by the dimensionless thermoelectric figure of merit(zT),which depends on parameters like Seebeck coefficient(S).展开更多
CONSPECTUS:There is an extensive history of research on both inorganic and hybrid metal halides,with the latter being first reported in the 1960s.Although work on hybrid systems has progressed steadily over the last 6...CONSPECTUS:There is an extensive history of research on both inorganic and hybrid metal halides,with the latter being first reported in the 1960s.Although work on hybrid systems has progressed steadily over the last 60 years,it has enjoyed a major renaissance during the last 5 years.This has arisen as a consequence of the 2009 discovery of the outstanding optoelectronic properties of hybrid lead halides,such as(MA)PbI_(3)(MA=methylammonium),and the recognition that there are many opportunities for equally exciting discoveries with compounds of the transition metals.Some of the early work on hybrid transition-metal halides put more emphasis on crystal structures but less on properties.In the modern era,we aim to grasp both the structure and properties,with a new twist.In this Account,we shall explore the recent developments in hybrid transition-metal halides with a focus on work in four main areas:magnetism,photoluminescence,semiconductivity,and spintronics.Our work on magnetism centers on the Ru-based hybrid halides,where the structural types are diversely composed of vacancy-ordered double perovskite,as well as chain-like one-dimensional structures and layered double perovskite(LDP)when paired with a(1+)metal.We explore their magnetic properties and find that their spin−orbit coupling(SOC)behavior can be tuned through changing the A cation and the halide.In the luminescence section,we focus on our recent works on hybrid tetrahedral Mn(II)bromides and Cu(I)and Ag(I)iodides.We correlated our newly discovered 0D A_(m)MnBr_(4)(A=organic cation,m=1 or 2)compounds with previous reports,and generated a trend where the photoluminescence quantum yield(PLQY)increases with larger Mn−Mn distances.The flexible organic cation becomes the most important tool here to tune the structure−PLQY relations.Cu(I)and Ag(I)iodides coordinated with iodides and organic ligands produce new crystal structures with intense PL.For the semiconducting properties,we explore the Pt-based vacancy-ordered double perovskite and hybrid bismuth and indium-based LDPs to show the structural evolution with different choices for the organic cation,the metal and the halide;these have a strong influence on the optical properties.The LDPs specifically exhibit high structure tunability,with a wide range of(1+)and(3+)metal choices,and are exempt from some of the limitations of 3D double perovskite.In the last section,we introduce the recent progress on hybrid transition-metal-based ferroelectrics and spintronic materials.We successfully demonstrate the utilization of chiral Cu(II)chlorides for circularly polarized light(CPL)detection,showing the high anisotropy of the photoresponsivity.We also highlight the work that the authors have contributed in these areas and suggest several exciting opportunities for future developments.展开更多
基金financial support from the NSFC-BRICS(No.81861148020,H.Xie)the Fundamental Research Funds for the Central Universities(H.Xie)+1 种基金the Research Program of State Key Laboratory of Bioreactor Engineering(H.Xie)DST-BRICS multilateral cooperation project(DST/IMRCD/BRICS/PilotCall2/MBLI/2018(G))。
文摘The expression ofβ-lactamase,particularly metallo-β-lactamase(MBL)in bacteria has caused significant resistance to clinically importantβ-lactam antibiotics,including life-saving carbapenems.Antimicrobial peptides(AMPs)have emerged as promising therapeutic agents to combat antibiotic resistance.However,the cytotoxic AMPs has been one of the major concerns for their applications in clinical practice.Herein,we report a novel cephalosporin-caged AMP,which shows significantly reduced cytotoxicity,hemolytic activity,and antibacterial activity but turns highly active against bacteria upon specific hydrolysis by the antimicrobial resistance-causativeβ-lactamase.Further investigations demonstrate thisβ-lactamaseactivatable AMP selectively inactivates resistant bacterial pathogens over susceptible bacteria.This strategy should be applicable to other AMPs as a potential solution for the treatment of infectious diseases caused byβ-lactamase-expressing pathogenic bacteria.
文摘The high quality single crystals of Yb5Co4Ge10 have been grown by the indium metal flux method and characterized by means of single crystal X-ray diffraction data. Yb5Co4Ge10 crystallizes in the Sc5Co4Si10 structure type, tetragonal space group P4/mbm and lattice constants are a = b = 12.6369(18) ? and c = 4.1378(8) ?. Crystal structure of Yb5Co4Ge10 composed of three-dimensional [Co4Ge12] network having five, six and eight membered rings. The three non-equivalent Yb atoms are sandwiched in three different channels created by the [Co4Ge12] network. Based on the bond length analysis from the crystallographic information, we confirmed that Yb1 and Yb2 atoms are in the trivalent magnetic state and Yb3 is in the divalent non-magnetic state.
文摘Sustainable thermoelectric materials open an avenue of emission-free as well as fast-responding recycling of energy in terms of heat to electricity.The efficiency(η)of such conversion is primarily guided by the dimensionless thermoelectric figure of merit(zT),which depends on parameters like Seebeck coefficient(S).
基金The work highlighted in this Account was supported by the Department of Energy,Office of Science,Basic Energy Sciences,under Grant No.SC0012541.L.M.thanks the SUSTech startup grant(Y01216150)P.V.thanks the Science&Engineering Research Board(SERB)of the Govt.of India for the Ramanujan Fellowship(Award No.RJF/2020/000106)the Jawaharlal Nehru Centre for Advanced Scientific Research(JNCASR)Bangalore for the financial support and the research infrastructure.
文摘CONSPECTUS:There is an extensive history of research on both inorganic and hybrid metal halides,with the latter being first reported in the 1960s.Although work on hybrid systems has progressed steadily over the last 60 years,it has enjoyed a major renaissance during the last 5 years.This has arisen as a consequence of the 2009 discovery of the outstanding optoelectronic properties of hybrid lead halides,such as(MA)PbI_(3)(MA=methylammonium),and the recognition that there are many opportunities for equally exciting discoveries with compounds of the transition metals.Some of the early work on hybrid transition-metal halides put more emphasis on crystal structures but less on properties.In the modern era,we aim to grasp both the structure and properties,with a new twist.In this Account,we shall explore the recent developments in hybrid transition-metal halides with a focus on work in four main areas:magnetism,photoluminescence,semiconductivity,and spintronics.Our work on magnetism centers on the Ru-based hybrid halides,where the structural types are diversely composed of vacancy-ordered double perovskite,as well as chain-like one-dimensional structures and layered double perovskite(LDP)when paired with a(1+)metal.We explore their magnetic properties and find that their spin−orbit coupling(SOC)behavior can be tuned through changing the A cation and the halide.In the luminescence section,we focus on our recent works on hybrid tetrahedral Mn(II)bromides and Cu(I)and Ag(I)iodides.We correlated our newly discovered 0D A_(m)MnBr_(4)(A=organic cation,m=1 or 2)compounds with previous reports,and generated a trend where the photoluminescence quantum yield(PLQY)increases with larger Mn−Mn distances.The flexible organic cation becomes the most important tool here to tune the structure−PLQY relations.Cu(I)and Ag(I)iodides coordinated with iodides and organic ligands produce new crystal structures with intense PL.For the semiconducting properties,we explore the Pt-based vacancy-ordered double perovskite and hybrid bismuth and indium-based LDPs to show the structural evolution with different choices for the organic cation,the metal and the halide;these have a strong influence on the optical properties.The LDPs specifically exhibit high structure tunability,with a wide range of(1+)and(3+)metal choices,and are exempt from some of the limitations of 3D double perovskite.In the last section,we introduce the recent progress on hybrid transition-metal-based ferroelectrics and spintronic materials.We successfully demonstrate the utilization of chiral Cu(II)chlorides for circularly polarized light(CPL)detection,showing the high anisotropy of the photoresponsivity.We also highlight the work that the authors have contributed in these areas and suggest several exciting opportunities for future developments.
