An increasing body of evidence shows that the lipid droplet,a neutral lipid storage organelle,plays a role in lipid metabolism and energy homeostasis through its interaction with mitochondria.However,the cellular func...An increasing body of evidence shows that the lipid droplet,a neutral lipid storage organelle,plays a role in lipid metabolism and energy homeostasis through its interaction with mitochondria.However,the cellular functions and molecular mechanisms of the interaction remain ambiguous.Here we present data from transmission electron microscopy,fluorescence imaging,and reconstitution assays,demonstrating that lipid droplets physically contact mitochondria in vivo and in vitro.Using a bimolecular fluorescence complementation assay in Saccharomyces cerevisiae,we generated an interactomic map of protein-protein contacts of lipid droplets with mitochondria and peroxisomes.The lipid droplet proteins Erg6 and Pet10 were found to be involved in 75%of the interactions detected.Interestingly,interactions between 3 pairs of lipid metabolic enzymes were detected.Collectively,these data demonstrate that lipid droplets make physical contacts with mitochondria and peroxisomes,and reveal specific molecular interactions that suggest active participation of lipid droplets in lipid metabolism in yeast.展开更多
The overestimation of the contaminant concentration is a main issue in simulating the reactive transport using the common advection-dispersion-reaction equation （ADRE）. To solve this problem, a new modeling method i...The overestimation of the contaminant concentration is a main issue in simulating the reactive transport using the common advection-dispersion-reaction equation （ADRE）. To solve this problem, a new modeling method is developed. The parameters of the model are identified based on experimental data. The results of the model are compared with previous results in the literature, and the sensitivity of the model is analyzed by examining the model＇s response to changes of the model parameters. Main conclusions are as follows： （1） The numerical modeling approach is feasible with an improved simulating accuracy. The predicted values are in agreement with the experimental measurements. The relative errors of the peak concentration between the simulated and experimental values are less than 2.5%. The errors are greatly reduced as compared with the results （about 67.8% as the maximum） based on a traditional ADRE in the literature. （2） There are three parameters （m, β0 and D ） which can be calibrated on the basis of experimental data in the model. The reactive product concentrations are mainly influenced by the parameters involved in the reactive ratio such as m and β0 The hydrodynamic dispersion coefficient D has almost no influence on the reactive product transport. （3） Our model does not provide better fitting curves for the ＂early arrival＂ and the ＂long tail＂. The ＂early arrival＂ and the ＂long tail＂ are associated with low values of the product AB. Under these conditions, the reaction rate is close to 0, and the model of the ADRE reduces to the advection-dispersion equation （ADE）. Further mechanism study is needed in the future.展开更多
Designing catalysts with capable dual-active sites to drive catalytic hydrogen generation is necessary for the future hydrogen economy.Herein,the interfacial active sites consisting of Co and Co-C on Co-Co_(2)C@carbon...Designing catalysts with capable dual-active sites to drive catalytic hydrogen generation is necessary for the future hydrogen economy.Herein,the interfacial active sites consisting of Co and Co-C on Co-Co_(2)C@carbon heterostructure are designed through annealing and highpressure carbonization.The operating temperature during the high-pressure carbonization under a CO-reducing environment is responsible for the construction and regulation of Co-Co_(2)C@C heterostructure.The optimal catalyst has a high turnover frequency(TOF) of33.1 min^(-1) and low activation energy(E_a) of27.3 kJ-mol^(-1) during the hydrolysis of NH_(3)BH_(3).The catalytic stability of Co-Co_(2)C@C has no dramatic deterioration even after 5 cyclic usages.The interfacial active sites and the carbon on the catalyst surface enhance hydrogen generation kinetics and catalytic stability.The construction of interfacial active sites in Co-Co_(2)C@C prompts the dissociation of reactants(NH_(3)BH_(3) and H_(2)O molecules),leading to an enhanced catalytic hydrogen generation from NH_(3)BH_(3) hydrolysis(Co activates NH_(3)BH_(3) and Co-C activates H_(2)O).The construction of hetero-structural catalysts provides theoretical direction for the rational design of advanced transition metal carbide materials in the field of energy catalysis and conversion.展开更多
Carbon dioxide reduction, as a sustainable and versatile strategy for the access of chemical fuels, has attracted increasing attention and enormous efforts have been devoted to it in recent years. However, employing c...Carbon dioxide reduction, as a sustainable and versatile strategy for the access of chemical fuels, has attracted increasing attention and enormous efforts have been devoted to it in recent years. However, employing carbon dioxide as double synthons via bimolecular reduction remains challenging. Here, by leveraging the bimolecular reduction of carbon dioxide to carbonyl and methyl respectively, we describe a Pd-catalyzed trifunctionalization of alkynes with aryl iodide for the first time and showcase its advantages on the formation of various β-diketones and their application in the constructing of heterocyclic compounds with important biological activity, including pyrimidine, oxazole, pyrazole.展开更多
Organic solar cells(OSCs)have attracted attention due to their lightweight nature,flexibility,and facile preparation using solution-based methods.Their efficiency has been further elevated by the rapid advancement of ...Organic solar cells(OSCs)have attracted attention due to their lightweight nature,flexibility,and facile preparation using solution-based methods.Their efficiency has been further elevated by the rapid advancement of nonfullerene materials,achieving individual cell efficiencies that surpass 19%.Hence,the stability of nonfullerene solar cell production must be scrutinized.The stability of the cathode interface layer significantly impacts the overall stability of OSC devices.PFN-Br,a commonly employed cathode interface material,is susceptible to degradation due to its sensitivity to environmental humidity,consequently compromising the device stability.In this study,we introduce fluorescent dye molecules,rhodamine 101,as cathode interface layers in OSCs to establish device stability and assess their universality.A comparative investigation of rhodamine 101 and PFN-Br devices demonstrates the former’s distinct advantages in terms of thermal stability,photostability,and storage stability even without encapsulation,particularly in an inert environment.By employing the Kelvin probe,we compare the work function of different cathode interface films and reveal that the work function of the rhodamine 101 interface material remains relatively unaffected by environmental factors.As a consequence,the device performance stability is significantly enhanced.The application of such fluorescent dye molecules extends the scope of cathode interface layers,amplifies device stability,and propels industrialization.展开更多
The structures of 20 bimolecular triplexes have been built and simulated by molecular mechanics. The sequence of pyrimidine strand is 5′ dTTCTTTC L\-1TTTL\-5 CTTTTCTT 3′, where the five nucleotides underlined compos...The structures of 20 bimolecular triplexes have been built and simulated by molecular mechanics. The sequence of pyrimidine strand is 5′ dTTCTTTC L\-1TTTL\-5 CTTTTCTT 3′, where the five nucleotides underlined compose loop sequences. L\-1 and L\-5 represent varied residues. The sequences of purine strands are 5′ dGAAAAGAA 3′ and the reversed orientation 5′ dAAGAAAG 3′. The influence of different loop sequences and composition on the relative stability of twenty triplexes have been energetically analyzed. The results indicate that 5′ loop triplexes are more stable than 3′ loop ones and the stacking interaction of purines with their adjacent bases are stronger than that of pyrimidines. The stability of triplexes is mainly determined by the first and last nucleotides in the loop.展开更多
The accessory proteins(3a, 3b, 6, 7a, 7b, 8a, 8b, 9b and ORF14), predicted unknown proteins(PUPs) encoded by the genes, are considered to be unique to the severe acute respiratory syndrome coronavirus(SARS-Co V) genom...The accessory proteins(3a, 3b, 6, 7a, 7b, 8a, 8b, 9b and ORF14), predicted unknown proteins(PUPs) encoded by the genes, are considered to be unique to the severe acute respiratory syndrome coronavirus(SARS-Co V) genome. These proteins play important roles in various biological processes mediated by interactions with their partners. However, very little is known about the interactions among these accessory proteins. Here, a EYFP(enhanced yellow fluorescent protein) bimolecular fluorescence complementation(BiFC) assay was used to detect the interactions among accessory proteins. 33 out of 81 interactions were identified by BiFC, much more than that identified by the yeast two-hybrid(Y2H)system. This is the first report describing direct visualization of interactions among accessory proteins of SARS-CoV. These findings attest to the general applicability of the BiFC system for the verification of protein-protein interactions.展开更多
Thermo-luminescence （TL） is a kind of luminescence decay measured with varying temperature. In the process of TL the decay parameter itself involves the temperature effect of traps. Thus the trap depth is inseparabl...Thermo-luminescence （TL） is a kind of luminescence decay measured with varying temperature. In the process of TL the decay parameter itself involves the temperature effect of traps. Thus the trap depth is inseparable from the decay parameter. There are two separate peaks in the TL curve of ZnS：Cu,Co if the measurement starts from liquid nitrogen temperature. In the experiment we started from zero Celsius temperature to isolate the deeper traps. We have proposed and realized three methods for simultaneous determination of trap depth and decay parameter based on the quasi-equilibrium model and experimental data. If we treat the case of kinetic order a = 1 as a = 2, the error might be as large as 100%.展开更多
A simple model based on the statistics of individual atoms [Europhys. Lett. 94 40002 （2011）] or molecules [Chin. Phys. Lett. 29 080504 （2012）] was used to predict chemical reaction rates without empirical paramete...A simple model based on the statistics of individual atoms [Europhys. Lett. 94 40002 （2011）] or molecules [Chin. Phys. Lett. 29 080504 （2012）] was used to predict chemical reaction rates without empirical parameters, and its physical basis was further investigated both theoretically and via MD simulations. The model was successfully applied to some reactions of extensive experimental data, showing that the model is significantly better than the conventional transition state theory. It is worth noting that the prediction of the model on ab initio level is much easier than the transition state theory or unimolecular RRKM theory.展开更多
Boron hydrides release an abundant amount of hydrogen in the presence of a suitable catalyst.Accelerating bimolecular activation kinetics is the key to designing cost-effective catalysts for borohydride hydrolysis.In ...Boron hydrides release an abundant amount of hydrogen in the presence of a suitable catalyst.Accelerating bimolecular activation kinetics is the key to designing cost-effective catalysts for borohydride hydrolysis.In this study,the bimolecular activation of a polar O-Co-P site demonstrated superior hydrogen-generation kinetics(turnover frequency,TOF=37 min−1,298 K)and low activation energy(41.0 kJ mol^(−1))close to that of noble-metal-based catalysts.Through a combination of experiments and theoretical calculations,it was revealed that the activated dangling oxygen atom in the Co–O precursor effectively replaced via surface-phosphorization because of strong electronic interactions between the dangling oxygen and P atoms.This substitution modulated the local coordination environment and electronegativity around the surface Co sites and formed a new polar O-Co-P active site for optimizing the activation kinetics of ammonia borane and water.This strategy based on bimolecular activation may create new avenues in the field of catalysis.展开更多
Effects of a benzotriazole(BTA)-based small molecule,BTA2,as the third component on the charge carrier generation and recombination behavior of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-di...Effects of a benzotriazole(BTA)-based small molecule,BTA2,as the third component on the charge carrier generation and recombination behavior of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]](PTB7):[6,6]-phenyl-C71-butyric acid methyl ester(PC71BM)organic solar cells(OSCs)were investigated by optical simulation of a transfer matrix model(TMM),photo-induced charge extraction by linearly increasing voltage(photo-CELIV)technique,atomic force microscope(AFM),and the Onsager–Braun model analysis.BTA2 is an A_(2)-A_(1)-D-A_(1)-A_(2)-type non-fullerene small molecule with thiazolidine-2,4-dione,BTA,and indacenodithiophene as the terminal acceptor(A_(2)),bridge acceptor(A_(1)),and central donor(D),respectively.The short-circuit current density of the OSCs with BTA2 can be enhanced significantly owing to a complementary absorption spectrum.The optical simulation of TMM shows that the ternary OSCs exhibit higher internal absorption than the traditional binary OSCs without BTA2,resulting in more photogenerated excitons in the ternary OSCs.The photo-CELIV investigation indicates that the ternary OSCs suffer higher charge trap-limited bimolecular recombination than the binary OSCs.AFM images show that BTA2 aggravates the phase separation between the donor and the acceptor,which is disadvantageous to charge carrier transport.The Onsager-Braun model analysis confirms that despite the charge collection efficiency of the ternary OSCs being lower than that of the binary OSCs,the optimized photon absorption and exciton generation processes of the ternary OSCs achieve an increase in photogenerated current and thus improve power conversion efficiency.展开更多
Genome-wide physical protein±protein interaction(PPI)mapping remains a major challenge for current technologies.Here,we reported a high-efficiency BiFC-seq method,yeastenhanced green fluorescent protein-based bim...Genome-wide physical protein±protein interaction(PPI)mapping remains a major challenge for current technologies.Here,we reported a high-efficiency BiFC-seq method,yeastenhanced green fluorescent protein-based bimolecular fluorescence complementation(y EGFPBiFC)coupled with next-generation DNA sequencing,for interactome mapping.We first applied y EGFP-BiFC method to systematically investigate an intraviral network of the Ebola virus.Two-thirds(9/14)of known interactions of EBOV were recaptured,and five novel interactions were discovered.Next,we used the BiFC-seq method to map the interactome of the tumor protein p53.We identified 97 interactors of p53,more than three-quarters of which were novel.Furthermore,in a more complex background,we screened potential interactors by pooling two BiFC libraries together and revealed a network of 229 interactions among 205 proteins.These results show that BiFC-seq is a highly sensitive,rapid,and economical method for genome-wide interactome mapping.展开更多
A polymer blend comprising poly(3-hexylthiophene)(P3HT)donor and poly[2,7-(9,9′-octyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl-5′,6′-bis(hexyloxy)-2′,1′,3′-benzothiadiazole)](PFDTBT-OC6)acceptor is used as the ac...A polymer blend comprising poly(3-hexylthiophene)(P3HT)donor and poly[2,7-(9,9′-octyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl-5′,6′-bis(hexyloxy)-2′,1′,3′-benzothiadiazole)](PFDTBT-OC6)acceptor is used as the active layer to fabricate all-polymer solar cells.The blend morphology variance processed with pure and mixed solvents,and the related photovoltaic performance,are investigated in detail.It is found that,due to its low surface energy,a thin P3HT enrichment layer on the top surface of the active layer greatly increases bimolecular recombination and results in S-kinks of the illuminated current density-voltage curves.With the incorporation of p-xylene(a marginal solvent of P3HT)in the blend solution,the P3HT enrichment atop the active layer surface is effectively decreased because the high boiling-point p-xylene suppresses the diffusion of P3HT chains toward the top surface during the film-drying process.The bimolecular recombination was thus improved and the S-kinks of the photovoltaic curves were completely removed.The overall power conversion efficiencies of the devices are strongly boosted(from 0.88%to 1.41%)when chlorobenzene:p-xylene mixed solvent is used to replace pure chlorobenzene.展开更多
Mulliken, NPA, MK and CHelpG population analyses have been accomplished at the level of MP2/6-31G（d,p） for the title system. The variations of four kinds of charges on NH3 with intermolecular distance infer that ele...Mulliken, NPA, MK and CHelpG population analyses have been accomplished at the level of MP2/6-31G（d,p） for the title system. The variations of four kinds of charges on NH3 with intermolecular distance infer that electron transfers from NH3 to H2O. MK and CHelpG population analyses indicate more electron transfer than Mulliken and NPA ones. The atomic charges resulted from MK and CHelpG schemes infer that electron transfers from N in NH3 to H in H2O, which confirms that this bimolecular complex possesses linear structure as H3N…HOH.展开更多
[Objective] The aim was to investigate the dimer formation between the movement proteins（MP）in barely yellow dwarf virus by using the technology of bimolecular fluorescence complementation technology and to further ...[Objective] The aim was to investigate the dimer formation between the movement proteins（MP）in barely yellow dwarf virus by using the technology of bimolecular fluorescence complementation technology and to further study the relationship between MP homodimerization and viral movement.[Method] The DNA sequence of bimolecular fluorescent complementary vector containing cloning multiple cloning sites,35S promoter and terminator was cloned into the expression vector pCAMBIA1300,which replicates at a higher copy number in E.coli.Then,the BYDV-MP gene fragment was amplified in the presence of the whole BYDV-PAV cDNA sequence as template and the primers designed according to the BYDV-MP gene sequence from GenBank,cloned into the modified bimolecular fluorescent complementary vectors pCAMBIA1300-NE and pCAMBIA1300-CE.The resulting vectors were transformed into Agrobacterium by electroporation method and infiltrated into the tobacco leaf.Protein interactions were observed under fluorescence microscope.[Result] Yellow fluorescence could be viewed in the leaves co-infiltrated with Agrobacterium carrying pCAMBIA1300NE-MP and pCAMBIA1300CE-MP at 2-5 d post-infiltration,while yellow fluorescence could not be observed in negative control groups.[Conclusion] BYDV-MP formed homodimers in plant cells.The results can provide theoretical basis for further in-depth research about the movement process and mechanism of BYDV.展开更多
基金supported by grants from the National Basic Research Program of China(Grant Nos.2009CB919000 and 2010CB833703)the National Natural Science Foundation of China(Grant Nos.30871229 and 30971431)the 21C Frontier Functional Proteomics Project(FPR08A1-060)funded by the Ministry of Education,Science and Technology,Republic of Korea.
文摘An increasing body of evidence shows that the lipid droplet,a neutral lipid storage organelle,plays a role in lipid metabolism and energy homeostasis through its interaction with mitochondria.However,the cellular functions and molecular mechanisms of the interaction remain ambiguous.Here we present data from transmission electron microscopy,fluorescence imaging,and reconstitution assays,demonstrating that lipid droplets physically contact mitochondria in vivo and in vitro.Using a bimolecular fluorescence complementation assay in Saccharomyces cerevisiae,we generated an interactomic map of protein-protein contacts of lipid droplets with mitochondria and peroxisomes.The lipid droplet proteins Erg6 and Pet10 were found to be involved in 75%of the interactions detected.Interestingly,interactions between 3 pairs of lipid metabolic enzymes were detected.Collectively,these data demonstrate that lipid droplets make physical contacts with mitochondria and peroxisomes,and reveal specific molecular interactions that suggest active participation of lipid droplets in lipid metabolism in yeast.
基金supported by the National Natural Science Foundation of China(Grant Nos.41372245,41272251)
文摘The overestimation of the contaminant concentration is a main issue in simulating the reactive transport using the common advection-dispersion-reaction equation （ADRE）. To solve this problem, a new modeling method is developed. The parameters of the model are identified based on experimental data. The results of the model are compared with previous results in the literature, and the sensitivity of the model is analyzed by examining the model＇s response to changes of the model parameters. Main conclusions are as follows： （1） The numerical modeling approach is feasible with an improved simulating accuracy. The predicted values are in agreement with the experimental measurements. The relative errors of the peak concentration between the simulated and experimental values are less than 2.5%. The errors are greatly reduced as compared with the results （about 67.8% as the maximum） based on a traditional ADRE in the literature. （2） There are three parameters （m, β0 and D ） which can be calibrated on the basis of experimental data in the model. The reactive product concentrations are mainly influenced by the parameters involved in the reactive ratio such as m and β0 The hydrodynamic dispersion coefficient D has almost no influence on the reactive product transport. （3） Our model does not provide better fitting curves for the ＂early arrival＂ and the ＂long tail＂. The ＂early arrival＂ and the ＂long tail＂ are associated with low values of the product AB. Under these conditions, the reaction rate is close to 0, and the model of the ADRE reduces to the advection-dispersion equation （ADE）. Further mechanism study is needed in the future.
基金financially supported by the National Natural Science Foundation of China (Nos.52071135, 51871090 and U1804135)the Fundamental Research Funds for the Universities of Henan Province (Nos.NSFRF220201 and NSFRF200402)。
文摘Designing catalysts with capable dual-active sites to drive catalytic hydrogen generation is necessary for the future hydrogen economy.Herein,the interfacial active sites consisting of Co and Co-C on Co-Co_(2)C@carbon heterostructure are designed through annealing and highpressure carbonization.The operating temperature during the high-pressure carbonization under a CO-reducing environment is responsible for the construction and regulation of Co-Co_(2)C@C heterostructure.The optimal catalyst has a high turnover frequency(TOF) of33.1 min^(-1) and low activation energy(E_a) of27.3 kJ-mol^(-1) during the hydrolysis of NH_(3)BH_(3).The catalytic stability of Co-Co_(2)C@C has no dramatic deterioration even after 5 cyclic usages.The interfacial active sites and the carbon on the catalyst surface enhance hydrogen generation kinetics and catalytic stability.The construction of interfacial active sites in Co-Co_(2)C@C prompts the dissociation of reactants(NH_(3)BH_(3) and H_(2)O molecules),leading to an enhanced catalytic hydrogen generation from NH_(3)BH_(3) hydrolysis(Co activates NH_(3)BH_(3) and Co-C activates H_(2)O).The construction of hetero-structural catalysts provides theoretical direction for the rational design of advanced transition metal carbide materials in the field of energy catalysis and conversion.
基金supported by the National Natural Science Foundation of China(21971073,22001075,22231002)the Natural Science Foundation of Guangdong Province(2019A1515011468)+2 种基金the Discipline Construction Project of Guangdong Medical University(4SG23231G,4SG23249G)the Ordinary University Characteristic Innovation Project of Guangdong Province(2022KTSCX047)the Key-Area Research and Development Program of Guangdong Province(2020B010188001)。
文摘Carbon dioxide reduction, as a sustainable and versatile strategy for the access of chemical fuels, has attracted increasing attention and enormous efforts have been devoted to it in recent years. However, employing carbon dioxide as double synthons via bimolecular reduction remains challenging. Here, by leveraging the bimolecular reduction of carbon dioxide to carbonyl and methyl respectively, we describe a Pd-catalyzed trifunctionalization of alkynes with aryl iodide for the first time and showcase its advantages on the formation of various β-diketones and their application in the constructing of heterocyclic compounds with important biological activity, including pyrimidine, oxazole, pyrazole.
基金financially supported by the Central Guidance on Local Science and Technology Develop-ment Fund Project of Hebei Province(Grant No.226Z4306G)the Natural Science Foundation of Hebei Province(Grant No.F2023201005)+4 种基金the National Key Research and Development Program of China(Grant No.2017YFA0206600)the National Natural Science Foundation of China(Grant Nos.21922505,21773045)the CAS Instrument Develop-ment Project(Grant No.YJKYYQ20190010)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB36000000)CAS-NST Joint Research Projects(Grant No.163GJHZ2023017MI).
文摘Organic solar cells(OSCs)have attracted attention due to their lightweight nature,flexibility,and facile preparation using solution-based methods.Their efficiency has been further elevated by the rapid advancement of nonfullerene materials,achieving individual cell efficiencies that surpass 19%.Hence,the stability of nonfullerene solar cell production must be scrutinized.The stability of the cathode interface layer significantly impacts the overall stability of OSC devices.PFN-Br,a commonly employed cathode interface material,is susceptible to degradation due to its sensitivity to environmental humidity,consequently compromising the device stability.In this study,we introduce fluorescent dye molecules,rhodamine 101,as cathode interface layers in OSCs to establish device stability and assess their universality.A comparative investigation of rhodamine 101 and PFN-Br devices demonstrates the former’s distinct advantages in terms of thermal stability,photostability,and storage stability even without encapsulation,particularly in an inert environment.By employing the Kelvin probe,we compare the work function of different cathode interface films and reveal that the work function of the rhodamine 101 interface material remains relatively unaffected by environmental factors.As a consequence,the device performance stability is significantly enhanced.The application of such fluorescent dye molecules extends the scope of cathode interface layers,amplifies device stability,and propels industrialization.
文摘The structures of 20 bimolecular triplexes have been built and simulated by molecular mechanics. The sequence of pyrimidine strand is 5′ dTTCTTTC L\-1TTTL\-5 CTTTTCTT 3′, where the five nucleotides underlined compose loop sequences. L\-1 and L\-5 represent varied residues. The sequences of purine strands are 5′ dGAAAAGAA 3′ and the reversed orientation 5′ dAAGAAAG 3′. The influence of different loop sequences and composition on the relative stability of twenty triplexes have been energetically analyzed. The results indicate that 5′ loop triplexes are more stable than 3′ loop ones and the stacking interaction of purines with their adjacent bases are stronger than that of pyrimidines. The stability of triplexes is mainly determined by the first and last nucleotides in the loop.
基金supported by National Natural Science Foundation of China (No. 81072673)
文摘The accessory proteins(3a, 3b, 6, 7a, 7b, 8a, 8b, 9b and ORF14), predicted unknown proteins(PUPs) encoded by the genes, are considered to be unique to the severe acute respiratory syndrome coronavirus(SARS-Co V) genome. These proteins play important roles in various biological processes mediated by interactions with their partners. However, very little is known about the interactions among these accessory proteins. Here, a EYFP(enhanced yellow fluorescent protein) bimolecular fluorescence complementation(BiFC) assay was used to detect the interactions among accessory proteins. 33 out of 81 interactions were identified by BiFC, much more than that identified by the yeast two-hybrid(Y2H)system. This is the first report describing direct visualization of interactions among accessory proteins of SARS-CoV. These findings attest to the general applicability of the BiFC system for the verification of protein-protein interactions.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10374001, 10434030 and 60576016）, the State Key Development Program for Basic Research of China （Grant No 2003CB314707）, the Excellent Doctor＇s Science and Technology Innovation Foundation of Beijing Jiaotong University （Grant No 48011）, Russian Foundation of Basic Research （Grant Nos 04-02- 16942 and 02-02-39007）.
文摘Thermo-luminescence （TL） is a kind of luminescence decay measured with varying temperature. In the process of TL the decay parameter itself involves the temperature effect of traps. Thus the trap depth is inseparable from the decay parameter. There are two separate peaks in the TL curve of ZnS：Cu,Co if the measurement starts from liquid nitrogen temperature. In the experiment we started from zero Celsius temperature to isolate the deeper traps. We have proposed and realized three methods for simultaneous determination of trap depth and decay parameter based on the quasi-equilibrium model and experimental data. If we treat the case of kinetic order a = 1 as a = 2, the error might be as large as 100%.
基金Project supported by the National Natural Science Foundation of China(Grant No.11274073)the Leading Academic Discipline Project of Shanghai,China(Grant No.B107)
文摘A simple model based on the statistics of individual atoms [Europhys. Lett. 94 40002 （2011）] or molecules [Chin. Phys. Lett. 29 080504 （2012）] was used to predict chemical reaction rates without empirical parameters, and its physical basis was further investigated both theoretically and via MD simulations. The model was successfully applied to some reactions of extensive experimental data, showing that the model is significantly better than the conventional transition state theory. It is worth noting that the prediction of the model on ab initio level is much easier than the transition state theory or unimolecular RRKM theory.
基金H.Z.and K.Z.contributed equally to this work.Financial supports from the National Natural Science Foundation of China (nos.22075254,52071135,51871090,U1804135,21805071,51671080,and 21401168)Plan for Scientific Inno-vation Talent of Henan Province (no.194200510019)Key Project of Educa-tional Commission of Henan Province (no.19A150025)are acknowledged.
文摘Boron hydrides release an abundant amount of hydrogen in the presence of a suitable catalyst.Accelerating bimolecular activation kinetics is the key to designing cost-effective catalysts for borohydride hydrolysis.In this study,the bimolecular activation of a polar O-Co-P site demonstrated superior hydrogen-generation kinetics(turnover frequency,TOF=37 min−1,298 K)and low activation energy(41.0 kJ mol^(−1))close to that of noble-metal-based catalysts.Through a combination of experiments and theoretical calculations,it was revealed that the activated dangling oxygen atom in the Co–O precursor effectively replaced via surface-phosphorization because of strong electronic interactions between the dangling oxygen and P atoms.This substitution modulated the local coordination environment and electronegativity around the surface Co sites and formed a new polar O-Co-P active site for optimizing the activation kinetics of ammonia borane and water.This strategy based on bimolecular activation may create new avenues in the field of catalysis.
基金This work was supported by the National Natural Science Foundation of China(Grant No.21811540393)Program for Changbaishan Scholars of Jilin Provincethe“Talents Cultivation Program”of Jilin University.
文摘Effects of a benzotriazole(BTA)-based small molecule,BTA2,as the third component on the charge carrier generation and recombination behavior of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]](PTB7):[6,6]-phenyl-C71-butyric acid methyl ester(PC71BM)organic solar cells(OSCs)were investigated by optical simulation of a transfer matrix model(TMM),photo-induced charge extraction by linearly increasing voltage(photo-CELIV)technique,atomic force microscope(AFM),and the Onsager–Braun model analysis.BTA2 is an A_(2)-A_(1)-D-A_(1)-A_(2)-type non-fullerene small molecule with thiazolidine-2,4-dione,BTA,and indacenodithiophene as the terminal acceptor(A_(2)),bridge acceptor(A_(1)),and central donor(D),respectively.The short-circuit current density of the OSCs with BTA2 can be enhanced significantly owing to a complementary absorption spectrum.The optical simulation of TMM shows that the ternary OSCs exhibit higher internal absorption than the traditional binary OSCs without BTA2,resulting in more photogenerated excitons in the ternary OSCs.The photo-CELIV investigation indicates that the ternary OSCs suffer higher charge trap-limited bimolecular recombination than the binary OSCs.AFM images show that BTA2 aggravates the phase separation between the donor and the acceptor,which is disadvantageous to charge carrier transport.The Onsager-Braun model analysis confirms that despite the charge collection efficiency of the ternary OSCs being lower than that of the binary OSCs,the optimized photon absorption and exciton generation processes of the ternary OSCs achieve an increase in photogenerated current and thus improve power conversion efficiency.
基金supported by grants from the National Key R&D Program of China(Grant No.2017YFA0505700)the National Key Lab of Proteomics of China(Grant Nos.SKLP-K201805,SKLP-K201804,and SKLP-Y201703)。
文摘Genome-wide physical protein±protein interaction(PPI)mapping remains a major challenge for current technologies.Here,we reported a high-efficiency BiFC-seq method,yeastenhanced green fluorescent protein-based bimolecular fluorescence complementation(y EGFPBiFC)coupled with next-generation DNA sequencing,for interactome mapping.We first applied y EGFP-BiFC method to systematically investigate an intraviral network of the Ebola virus.Two-thirds(9/14)of known interactions of EBOV were recaptured,and five novel interactions were discovered.Next,we used the BiFC-seq method to map the interactome of the tumor protein p53.We identified 97 interactors of p53,more than three-quarters of which were novel.Furthermore,in a more complex background,we screened potential interactors by pooling two BiFC libraries together and revealed a network of 229 interactions among 205 proteins.These results show that BiFC-seq is a highly sensitive,rapid,and economical method for genome-wide interactome mapping.
基金supported by the National Basic Research Program of China(2014CB643504)the National Natural Science Foundation of China(51325303,51273193,21334006)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB12030200)
文摘A polymer blend comprising poly(3-hexylthiophene)(P3HT)donor and poly[2,7-(9,9′-octyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl-5′,6′-bis(hexyloxy)-2′,1′,3′-benzothiadiazole)](PFDTBT-OC6)acceptor is used as the active layer to fabricate all-polymer solar cells.The blend morphology variance processed with pure and mixed solvents,and the related photovoltaic performance,are investigated in detail.It is found that,due to its low surface energy,a thin P3HT enrichment layer on the top surface of the active layer greatly increases bimolecular recombination and results in S-kinks of the illuminated current density-voltage curves.With the incorporation of p-xylene(a marginal solvent of P3HT)in the blend solution,the P3HT enrichment atop the active layer surface is effectively decreased because the high boiling-point p-xylene suppresses the diffusion of P3HT chains toward the top surface during the film-drying process.The bimolecular recombination was thus improved and the S-kinks of the photovoltaic curves were completely removed.The overall power conversion efficiencies of the devices are strongly boosted(from 0.88%to 1.41%)when chlorobenzene:p-xylene mixed solvent is used to replace pure chlorobenzene.
基金the National Science Foundation (29773021) and Provisional Educational Foundation of Jiangsu (98KJB150001).
文摘Mulliken, NPA, MK and CHelpG population analyses have been accomplished at the level of MP2/6-31G（d,p） for the title system. The variations of four kinds of charges on NH3 with intermolecular distance infer that electron transfers from NH3 to H2O. MK and CHelpG population analyses indicate more electron transfer than Mulliken and NPA ones. The atomic charges resulted from MK and CHelpG schemes infer that electron transfers from N in NH3 to H in H2O, which confirms that this bimolecular complex possesses linear structure as H3N…HOH.
基金Supported by National Natural Science Foundation of China(30870109)~~
文摘[Objective] The aim was to investigate the dimer formation between the movement proteins（MP）in barely yellow dwarf virus by using the technology of bimolecular fluorescence complementation technology and to further study the relationship between MP homodimerization and viral movement.[Method] The DNA sequence of bimolecular fluorescent complementary vector containing cloning multiple cloning sites,35S promoter and terminator was cloned into the expression vector pCAMBIA1300,which replicates at a higher copy number in E.coli.Then,the BYDV-MP gene fragment was amplified in the presence of the whole BYDV-PAV cDNA sequence as template and the primers designed according to the BYDV-MP gene sequence from GenBank,cloned into the modified bimolecular fluorescent complementary vectors pCAMBIA1300-NE and pCAMBIA1300-CE.The resulting vectors were transformed into Agrobacterium by electroporation method and infiltrated into the tobacco leaf.Protein interactions were observed under fluorescence microscope.[Result] Yellow fluorescence could be viewed in the leaves co-infiltrated with Agrobacterium carrying pCAMBIA1300NE-MP and pCAMBIA1300CE-MP at 2-5 d post-infiltration,while yellow fluorescence could not be observed in negative control groups.[Conclusion] BYDV-MP formed homodimers in plant cells.The results can provide theoretical basis for further in-depth research about the movement process and mechanism of BYDV.
