Four hitherto unknown polysubstituted isofiavonoids,including three isofiavans:7,4'-dihydroxy-8,2',3'-trimethoxyisofiavan(1),7,2',4'-trihydroxy-8,3'-dimethoxyisofiavan(2),and 7,2',4'-tr...Four hitherto unknown polysubstituted isofiavonoids,including three isofiavans:7,4'-dihydroxy-8,2',3'-trimethoxyisofiavan(1),7,2',4'-trihydroxy-8,3'-dimethoxyisofiavan(2),and 7,2',4'-trihydroxy-5-methoxyisofiavan(3),and one prenylated isofiavone cudraisofiavone M(4)were isolated from the ethanol extracts of Spatholobus suberectus(for 1 and 2),Flemingia macrophylla(for 3),and Cudrania cochinchinensis(for 4),respectively.Their structures were established on the basis of extensive spectroscopic analysis.Compounds 1 and 4 exhibited weak cytotoxic activity against five human cancer cell lines(HL-60,A-549,SMMC-7721,MCF-7,and SW-480).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
The introduction of hydroxy group to the 3- or 5-position of 4,4-difluoro-4-bora-3aAa-diazaindacene （BODIPY） results in unexpected tautomerization to BDPONa with interesting structural and photophysical properties. ...The introduction of hydroxy group to the 3- or 5-position of 4,4-difluoro-4-bora-3aAa-diazaindacene （BODIPY） results in unexpected tautomerization to BDPONa with interesting structural and photophysical properties. The core of BDPONa is an anion with sodium cation as counter-ion. BDPONa displays strong fluorescence in organic solvents.展开更多
Human face can be rebuilt to a three-dimensional (3 D) digital profile based on an optical 3D sensing system named Composite Fourier-Transform Profilometry (CFTP) where a composite structured light will be used. To st...Human face can be rebuilt to a three-dimensional (3 D) digital profile based on an optical 3D sensing system named Composite Fourier-Transform Profilometry (CFTP) where a composite structured light will be used. To study the sampling effect during the digitization process in practical CFTP, the pectinate function and convolution theorem were introduced to discuss the potential phase errors caused by sampling the composite pattern along two orthogonal directions. The selecting criterions of sampling frequencies are derived and the results indicate that to avoid spectral aliasing, the sampling frequency along the phrase variation direction must be at least four times as the baseband and along the orthogonal direction it must be at least three times as the larger frequency of the two carrier frequencies. The practical experiment of a model face reconstruction verified the theories.展开更多
Tip-enhanced Raman spectroscopy （TERS） is high-sensitivity and high spatial-resolution optical analytical technique with nanoscale resolution beyond the diffraction limit. It is also one of the most recent advances ...Tip-enhanced Raman spectroscopy （TERS） is high-sensitivity and high spatial-resolution optical analytical technique with nanoscale resolution beyond the diffraction limit. It is also one of the most recent advances in nanoscale chemical analysis. This review provides an overview of the state-of-art inTERS, in-depth information about the different available types of instruments including their （dis）advantages and capabilities. Finally, an overview about recent development in High-Vacuum TERS is given and some challenges are raised.展开更多
基金supported by the"Large-scale Compound Library"project of National Development and Reform Commission of China.
文摘Four hitherto unknown polysubstituted isofiavonoids,including three isofiavans:7,4'-dihydroxy-8,2',3'-trimethoxyisofiavan(1),7,2',4'-trihydroxy-8,3'-dimethoxyisofiavan(2),and 7,2',4'-trihydroxy-5-methoxyisofiavan(3),and one prenylated isofiavone cudraisofiavone M(4)were isolated from the ethanol extracts of Spatholobus suberectus(for 1 and 2),Flemingia macrophylla(for 3),and Cudrania cochinchinensis(for 4),respectively.Their structures were established on the basis of extensive spectroscopic analysis.Compounds 1 and 4 exhibited weak cytotoxic activity against five human cancer cell lines(HL-60,A-549,SMMC-7721,MCF-7,and SW-480).
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financially supported by the 973 program (Nos.2013CB933800,2013CB834505)National Natural Science Foundation of China (Nos.21222210,21102155,91027041)the Chinese Academy of Sciences (100 Talents Program)
文摘The introduction of hydroxy group to the 3- or 5-position of 4,4-difluoro-4-bora-3aAa-diazaindacene （BODIPY） results in unexpected tautomerization to BDPONa with interesting structural and photophysical properties. The core of BDPONa is an anion with sodium cation as counter-ion. BDPONa displays strong fluorescence in organic solvents.
文摘Human face can be rebuilt to a three-dimensional (3 D) digital profile based on an optical 3D sensing system named Composite Fourier-Transform Profilometry (CFTP) where a composite structured light will be used. To study the sampling effect during the digitization process in practical CFTP, the pectinate function and convolution theorem were introduced to discuss the potential phase errors caused by sampling the composite pattern along two orthogonal directions. The selecting criterions of sampling frequencies are derived and the results indicate that to avoid spectral aliasing, the sampling frequency along the phrase variation direction must be at least four times as the baseband and along the orthogonal direction it must be at least three times as the larger frequency of the two carrier frequencies. The practical experiment of a model face reconstruction verified the theories.
文摘Tip-enhanced Raman spectroscopy （TERS） is high-sensitivity and high spatial-resolution optical analytical technique with nanoscale resolution beyond the diffraction limit. It is also one of the most recent advances in nanoscale chemical analysis. This review provides an overview of the state-of-art inTERS, in-depth information about the different available types of instruments including their （dis）advantages and capabilities. Finally, an overview about recent development in High-Vacuum TERS is given and some challenges are raised.
