A monolithic column-based mass spectrometry(MS)analysis kit was prepared for whole blood analysis with MS.The kit is disposable and can be used for purification,storage,transportation and direct analysis of whole bloo...A monolithic column-based mass spectrometry(MS)analysis kit was prepared for whole blood analysis with MS.The kit is disposable and can be used for purification,storage,transportation and direct analysis of whole blood.The kit mainly consists of a capillary for quantitative microsampling,a cation exchange monolithic column for purification and storage,and a syringe for loading sample.This kit is very friendly to various users that one can easily siphon the blood in the kit followed by rapid clean-up.We established a quantitative method using the kit with a limit detection as low as 0.33 nmol/L,and achieved more than five orders of magnitude enhancement in sensitivity compared to direct nanoelectrospray ionization MS analysis.The column can avoid analyte exposure to environment,which helps the storage of the sample for laboratory analysis.The relative standard deviation of immediate blood analysis and storage blood analysis within 10 d was less than 10%.This method has been successfully applied to the quantitative analysis of procainamide hydrochloride in 2μL rat blood.These results indicate that this disposable kit does have the potential to achieve highly sensitive quantitative MS analysis in biological samples,which is expected to become a cost-effective and powerful tool for in vitro diagnostics.展开更多
Inclusion of MARs in transgene cassettes enhances their expression and reduces position-effect variations in the transgenic host. Four new MARs (TM2, TM3, AM1 and AM2) were isolated from tobacco and Arabidopsis by PCR...Inclusion of MARs in transgene cassettes enhances their expression and reduces position-effect variations in the transgenic host. Four new MARs (TM2, TM3, AM1 and AM2) were isolated from tobacco and Arabidopsis by PCR method. The nuclei isolated from suspension-cultured cells of rice were used to prepare nuclear matrix. With a characterized MAR (TM1) as a positive control, the Matrix-MAR interactions were tested by an in vitro binding assay to identify the DNA sequences as MARs and their binding strength to nuclear matrix in vitro was compared. The results showed that TM2 and TM3 had stronger binding strength than TM1. To determine the functions of the four new MARs in vivo, binary vectors pBI121 carrying a uidA GUS reporter gene were modified with direct repeat MARs inserted on both sides of the reporter gene cassette and were transferred into tobaccos via Agrobacterium-mediated transformation procedure. Quantitative GUS assays of the transgenic tobaccos showed that when flanking a GUS reporter gene展开更多
In this review, we summarize our recent results on matrix isolation infrared spectroscopic studies and theoretical investigations of noble gas-transition metal oxide complexes. The results show that some transition me...In this review, we summarize our recent results on matrix isolation infrared spectroscopic studies and theoretical investigations of noble gas-transition metal oxide complexes. The results show that some transition metal oxide species trapped in solid noble gas matrices are chemically coordinated by one or multiple noble gas atoms forming noble gas complexes and, hence, cannot be regarded as isolated species. Noble gas coordination alters the vibrational frequencies as well as the geometric and electronic structures of transition metal oxide species trapped in solid noble gas matrixes. The interactions between noble gas atoms and transition metal oxides involve ion-induced dipole interactions as well as chemical bonding interactions. Periodic trends in the bonding in these noble gas-transition metal complexes are discussed.展开更多
Constrained spectral non-negative matrix factorization(NMF)analysis of perturbed oscillatory process control loop variable data is performed for the isolation of multiple plant-wide oscillatory sources.The technique i...Constrained spectral non-negative matrix factorization(NMF)analysis of perturbed oscillatory process control loop variable data is performed for the isolation of multiple plant-wide oscillatory sources.The technique is described and demonstrated by analyzing data from both simulated and real plant data of a chemical process plant. Results show that the proposed approach can map multiple oscillatory sources onto the most appropriate control loops,and has superior performance in terms of reconstruction accuracy and intuitive understanding compared with spectral independent component analysis(ICA).展开更多
In this paper,a new approach to design terahertz(THz)E-plane crossover coupler is reported.By cascading two symmetrical septum polarizers,a simple structure with wide operating bandwidth and high isolation performance...In this paper,a new approach to design terahertz(THz)E-plane crossover coupler is reported.By cascading two symmetrical septum polarizers,a simple structure with wide operating bandwidth and high isolation performance is achieved.The working principle is explained by operating waveguide modes.To simplify the optimization process,the scattering matrix(S-matrix)of the crossover is calculated.Two prototypes loaded and unloaded electromagnetic band gap(EBG)are fabricated and measured.The electrical contact problem at assembly plane is eliminated by the prototype loaded EBG.A measured bandwidth of 17.3%from 92.5 to 110 GHz for reflection and isolation coefficients<-15 dB and transmission coefficient>-2 dB is achieved.展开更多
Criegee intermediates(CIs),also known as carbonyl oxide,are reactive intermediates that play an important role in the atmospheric chemistry.Investigation on the structures and reactivity of CIs is of fundamental impor...Criegee intermediates(CIs),also known as carbonyl oxide,are reactive intermediates that play an important role in the atmospheric chemistry.Investigation on the structures and reactivity of CIs is of fundamental importance in understanding the underlying mechanism of their atmospheric reactions.In sharp contrast to the intensively studied parent molecule(CH_(2)OO)and the alkyl-substituted derivatives,the knowledge about the fluorinated analogue CF_(3)C(H)OO is scarce.By carefully heating the triplet carbene CF_(3)CH in an O2-doped Ar-matrix to 35 K,the elusive carbonyl oxide CF_(3)C(H)OO in syn-and anti-conformations has been generated and characterized with infrared(IR)and ultraviolet-visible(UV-vis)spectroscopy.The spectroscopic identification is supported by^(18)O-labeling experiments and quantum chemical calculations at the B3 LYP/6-311++G(3df,3pd)and MP2/6-311++G(2d,2p)levels.Upon the long-wavelength irradiation(λ>680 nm),both conformers of CF_(3)C(H)OO decompose to give trifluoroacetaldehyde CF_(3)C(H)O and simultaneously rearrange to the isomeric dioxirane,cyclic-CF_(3)CH(OO),which undergoes isomerization to the lowest-energy carboxylic acid CF_(3)C(O)OH upon UV-light excitation at 365 nm.The O_(2)-oxidation of CF_(3)CH via the intermediacy of CF_(3)C(H)OO and cyclic-CF_(3)CH(OO)might provide new insight into the mechanism for the degradation of hydro-chlorofluorocarbon CF_(3)CHCl_(2)(HCFC-123)in the atmosphere.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22104112)the startup foundation of Wuhan University(No.600460076).
文摘A monolithic column-based mass spectrometry(MS)analysis kit was prepared for whole blood analysis with MS.The kit is disposable and can be used for purification,storage,transportation and direct analysis of whole blood.The kit mainly consists of a capillary for quantitative microsampling,a cation exchange monolithic column for purification and storage,and a syringe for loading sample.This kit is very friendly to various users that one can easily siphon the blood in the kit followed by rapid clean-up.We established a quantitative method using the kit with a limit detection as low as 0.33 nmol/L,and achieved more than five orders of magnitude enhancement in sensitivity compared to direct nanoelectrospray ionization MS analysis.The column can avoid analyte exposure to environment,which helps the storage of the sample for laboratory analysis.The relative standard deviation of immediate blood analysis and storage blood analysis within 10 d was less than 10%.This method has been successfully applied to the quantitative analysis of procainamide hydrochloride in 2μL rat blood.These results indicate that this disposable kit does have the potential to achieve highly sensitive quantitative MS analysis in biological samples,which is expected to become a cost-effective and powerful tool for in vitro diagnostics.
基金This work was supported by the National Special Program for Research and Industrialization of Transgenic Plants (Grant No. J99-A-038) the National Natural Science Foundation of China (Grant No. 39970075).
文摘Inclusion of MARs in transgene cassettes enhances their expression and reduces position-effect variations in the transgenic host. Four new MARs (TM2, TM3, AM1 and AM2) were isolated from tobacco and Arabidopsis by PCR method. The nuclei isolated from suspension-cultured cells of rice were used to prepare nuclear matrix. With a characterized MAR (TM1) as a positive control, the Matrix-MAR interactions were tested by an in vitro binding assay to identify the DNA sequences as MARs and their binding strength to nuclear matrix in vitro was compared. The results showed that TM2 and TM3 had stronger binding strength than TM1. To determine the functions of the four new MARs in vivo, binary vectors pBI121 carrying a uidA GUS reporter gene were modified with direct repeat MARs inserted on both sides of the reporter gene cassette and were transferred into tobaccos via Agrobacterium-mediated transformation procedure. Quantitative GUS assays of the transgenic tobaccos showed that when flanking a GUS reporter gene
基金supported by the National Basic Research Program of China (Grant No. 2007CB815203)the National Natural Science Foundation of China (Grant Nos. 20773030 and 20803066)
文摘In this review, we summarize our recent results on matrix isolation infrared spectroscopic studies and theoretical investigations of noble gas-transition metal oxide complexes. The results show that some transition metal oxide species trapped in solid noble gas matrices are chemically coordinated by one or multiple noble gas atoms forming noble gas complexes and, hence, cannot be regarded as isolated species. Noble gas coordination alters the vibrational frequencies as well as the geometric and electronic structures of transition metal oxide species trapped in solid noble gas matrixes. The interactions between noble gas atoms and transition metal oxides involve ion-induced dipole interactions as well as chemical bonding interactions. Periodic trends in the bonding in these noble gas-transition metal complexes are discussed.
基金Supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry.
文摘Constrained spectral non-negative matrix factorization(NMF)analysis of perturbed oscillatory process control loop variable data is performed for the isolation of multiple plant-wide oscillatory sources.The technique is described and demonstrated by analyzing data from both simulated and real plant data of a chemical process plant. Results show that the proposed approach can map multiple oscillatory sources onto the most appropriate control loops,and has superior performance in terms of reconstruction accuracy and intuitive understanding compared with spectral independent component analysis(ICA).
基金the National Natural Science Foundation of China under Grant No.61474112 and Grant No.62001039.
文摘In this paper,a new approach to design terahertz(THz)E-plane crossover coupler is reported.By cascading two symmetrical septum polarizers,a simple structure with wide operating bandwidth and high isolation performance is achieved.The working principle is explained by operating waveguide modes.To simplify the optimization process,the scattering matrix(S-matrix)of the crossover is calculated.Two prototypes loaded and unloaded electromagnetic band gap(EBG)are fabricated and measured.The electrical contact problem at assembly plane is eliminated by the prototype loaded EBG.A measured bandwidth of 17.3%from 92.5 to 110 GHz for reflection and isolation coefficients<-15 dB and transmission coefficient>-2 dB is achieved.
基金supported by the National Natural Science Foundation of China(Nos.22003010 and 22025301)
文摘Criegee intermediates(CIs),also known as carbonyl oxide,are reactive intermediates that play an important role in the atmospheric chemistry.Investigation on the structures and reactivity of CIs is of fundamental importance in understanding the underlying mechanism of their atmospheric reactions.In sharp contrast to the intensively studied parent molecule(CH_(2)OO)and the alkyl-substituted derivatives,the knowledge about the fluorinated analogue CF_(3)C(H)OO is scarce.By carefully heating the triplet carbene CF_(3)CH in an O2-doped Ar-matrix to 35 K,the elusive carbonyl oxide CF_(3)C(H)OO in syn-and anti-conformations has been generated and characterized with infrared(IR)and ultraviolet-visible(UV-vis)spectroscopy.The spectroscopic identification is supported by^(18)O-labeling experiments and quantum chemical calculations at the B3 LYP/6-311++G(3df,3pd)and MP2/6-311++G(2d,2p)levels.Upon the long-wavelength irradiation(λ>680 nm),both conformers of CF_(3)C(H)OO decompose to give trifluoroacetaldehyde CF_(3)C(H)O and simultaneously rearrange to the isomeric dioxirane,cyclic-CF_(3)CH(OO),which undergoes isomerization to the lowest-energy carboxylic acid CF_(3)C(O)OH upon UV-light excitation at 365 nm.The O_(2)-oxidation of CF_(3)CH via the intermediacy of CF_(3)C(H)OO and cyclic-CF_(3)CH(OO)might provide new insight into the mechanism for the degradation of hydro-chlorofluorocarbon CF_(3)CHCl_(2)(HCFC-123)in the atmosphere.
