In this paper we present the enhanced X-ray Timing and Polarimetry mission—eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The m...In this paper we present the enhanced X-ray Timing and Polarimetry mission—eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring effects of QED, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics that will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. In particular, its wide field monitoring capabilities will be highly instrumental to detect the electro-magnetic counterparts of gravitational wave sources.The paper provides a detailed description of:(1) the technological and technical aspects, and the expected performance of the instruments of the scientific payload;(2) the elements and functions of the mission, from the spacecraft to the ground segment.展开更多
Pancreatic ductal adenocarcinoma(PDA)is among the deadliest cancers in the United States and in the world.Late diagnosis,early metastasis and lack of effective therapy are among the reasons why only 6%of patients diag...Pancreatic ductal adenocarcinoma(PDA)is among the deadliest cancers in the United States and in the world.Late diagnosis,early metastasis and lack of effective therapy are among the reasons why only 6%of patients diagnosed with PDA survive past 5 years.Despite development of targeted therapy against other cancers,little progression has been made in the treatment of PDA.Therefore,there is an urgent need for the development of new treatments.However,in order to proceed with treatments,the complicated biology of PDA needs to be understood first.Interestingly,majority of the tumor volume is not made of malignant epithelial cells but of stroma.In recent years,it has become evident that there is an important interaction between the stromal compartment and the less prevalent malignant cells,leading to cancer progression.The stroma not only serves as a growth promoting source of signals but it is also a physical barrier to drug delivery.Understanding the tumor-stroma signaling leading to development of desmoplastic reaction and tumor progression can lead to the development of therapies to decrease stromal activity and improve drug delivery.In this review,we focus on how the current understanding of biology of the pancreatic tumor microenvironment can be translated into the development of targeted therapy.展开更多
To address the increasing need for detecting and validating protein biomarkers in clinical specimens,mass spectrometry(MS)-based targeted proteomic techniques,including the selected reaction monitoring(SRM),parallel r...To address the increasing need for detecting and validating protein biomarkers in clinical specimens,mass spectrometry(MS)-based targeted proteomic techniques,including the selected reaction monitoring(SRM),parallel reaction monitoring(PRM),and massively parallel dataindependent acquisition(DIA),have been developed.For optimal performance,they require the fragment ion spectra of targeted peptides as prior knowledge.In this report,we describe a MS pipeline and spectral resource to support targeted proteomics studies for human tissue samples.To build the spectral resource,we integrated common open-source MS computational tools to assemble a freely accessible computational workflow based on Docker.We then applied the workflow to generate DPHL,a comprehensive DIA pan-human library,from 1096 data-dependent acquisition(DDA)MS raw files for 16 types of cancer samples.This extensive spectral resource was then applied to a proteomic study of 17 prostate cancer(PCa)patients.Thereafter,PRM validation was applied to a larger study of 57 PCa patients and the differential expression of three proteins in prostate tumor was validated.As a second application,the DPHL spectral resource was applied to a study consisting of plasma samples from 19 diffuse large B cell lymphoma(DLBCL)patients and 18 healthy control subjects.Differentially expressed proteins between DLBCL patients and healthy control subjects were detected by DIA-MS and confirmed by PRM.These data demonstrate that the DPHL supports DIA and PRM MS pipelines for robust protein biomarker discovery.DPHL is freely accessible at https://www.iprox.org/page/project.html?id=IPX0001400000.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neut...The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.展开更多
Selective oxidation of glycerol provides a feasible route towards the sustainable synthesis of high value-added chemicals.Herein,the hydroxyapatite(HAP)supported palladium(Pd)species were fabricated by impregnation an...Selective oxidation of glycerol provides a feasible route towards the sustainable synthesis of high value-added chemicals.Herein,the hydroxyapatite(HAP)supported palladium(Pd)species were fabricated by impregnation and subsequent calcination.The as-obtained heterogeneous Pd catalyst afforded not only excellent selectivity to glyceric acid(GLA)up to 90%with 59%conversion of glycerol but also good recyclability by using molecular oxygen as an oxidant under mild conditions.The characterization of catalysts indicated that both the surface basicity and Pd sites on the catalyst played a crucial role in promoting glycerol oxidation.Notably,it demonstrated that the presence of the vicinal hydroxyl group of glycerol molecule can assist the oxidation reaction via forming a coordination between the vicinal hydroxyl group and Ca^(2+) sites on HAP-derived catalysts.In this catalytic process,the secondary hydroxyl of glycerol kept untouched and the primary hydroxyl of glycerol was converted into carboxyl group,while the Pd species acted as active centers for cooperatively promoting the subsequent oxidation to generate GLA.Additionally,this catalytic system can be extended widely for the oxidative conversion of other vicinal diols into the corresponding a-hydroxycarboxylic acids selectively.Isotope labeling experiment using H_(2)^(18)O confirmed that H_(2)O not only acted as solvent but also was involved in the catalytic cycles.On the basis of the results,a possible reaction mechanism has been proposed.The HAP-supported Pd catalytic system has been shown to serve as an effective approach for the upgrading of bio-derived vicinal diols to high value-added chemicals.展开更多
This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene...This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene with the help of a self designed microflow device and characterized by GPC and in situ ^7Li NMR. It was found that n-BuLl tended to form the hexameric-aggregated structure and even to form the huge aggregated structure based on the former. These aggregations of initiators could directly initiate the anionic polymerization and form the su-pramolecule aggregations. The supramolecule aggregations inevitably blocked the diffusion of the monomers to the ion-pairs and resulted in a stationary-conversion platform. Then the aggregators were dissociated completely into equal binary-aggregated species, and the polymerization continued again rapidly before the termination. Tetrahy-drofuran （THF） acted as the electron donator, which could push the electron cloud to Li cation and make the aggre- gated ring of the active species rather loosened and facilitated the monomer to insert in. Therefore, a little THF can greatly promote the anionic polymerization. However, further addition of THF might block the channel between the ion-pairs and decrease the propagation rate. It was also found that the aggregated structure of the active species during the anionic polymerization only depends on the initiator aggregations which were formed before the polym-erization.展开更多
Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours.These taxa often have complex and poorly understood life cycles,lack observab...Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours.These taxa often have complex and poorly understood life cycles,lack observable,discriminatory morphological characters,and may not be amenable to in vitro culturing.As a result,species identification is frequently difficult.Molecular(DNA sequence)data have emerged as crucial information for the taxonomic identification of plant pathogenic fungi,with the nuclear ribosomal internal transcribed spacer(ITS)region being the most popular marker.However,international nucleotide sequence databases are accumulating numerous sequences of compromised or low-resolution taxonomic annotations and substandard technical quality,making their use in the molecular identification of plant pathogenic fungi problematic.Here we report on a concerted effort to identify high-quality reference sequences for various plant pathogenic fungi and to re-annotate incorrectly or insufficiently annotated public ITS sequences from these fungal lineages.A third objective was to enrich the sequences with geographical and ecological metadata.The results-a total of 31,954 changes-are incorporated in and made available through the UNITE database for molecular identification of fungi(http://unite.ut.ee),including standalone FASTA files of sequence data for local BLAST searches,use in the next-generation sequencing analysis platforms QIIME and mothur,and related applications.The present initiative is just a beginning to cover the wide spectrum of plant pathogenic fungi,and we invite all researchers with pertinent expertise to join the annotation effort.展开更多
In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry(eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be rep...In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry(eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to be launched in the mid 2020 s.展开更多
It still remains a concern to break through the bottlenecks of anionic polymerization of polar monomers, such as side reactions, low conver- sion and low temperature （-78 ℃）. In this work, potassium tert-butoxide ...It still remains a concern to break through the bottlenecks of anionic polymerization of polar monomers, such as side reactions, low conver- sion and low temperature （-78 ℃）. In this work, potassium tert-butoxide （t-BuOK） was chosen to initiate the anionic polymerization of 2-ethylhexyl methacrylate （EHMA） in tetrahydrofuran. The conversions were above 99% at 0 or 30 ℃, and above 95% at 60 ℃ without side reaction inhibitors. The high conversions implied t-BuOK could suppress the side reactions. A series of block copolymers of EHMA, n-hexyl methacrylate （HMA） and methyl methacrylate （MMA） were further synthesized at 0 ℃, and the conversions were all above 99%. The GPC and IH NMR results confirmed the successful synthesis of the block copolymers. The molecular size of monomer and the state of t-BuOK （free ion pairs or aggregates） remarkably affected the polymerization rates and the molecular structures of the products. The DMA results indicated that the glass transition temperatures of PEHMA or PHMA block and PMMA block were 20 ℃ and 60 ℃, respectively, which deviated from -2 ℃ and 105 ℃ of homopolymer, respectively, due to the partial com- patibility of the blocks. This work explored a route of the anionic polymerization of polar monomers at room temperature.展开更多
This work confirmed a novel ligand in the anionic polymerization,lithium phenoxide,which helped to improve the controllability of the polymerization.The stability of n-BuLi against THF at 0℃ was effectively improved ...This work confirmed a novel ligand in the anionic polymerization,lithium phenoxide,which helped to improve the controllability of the polymerization.The stability of n-BuLi against THF at 0℃ was effectively improved by adding lithium phenoxide.More than 60%n-BuLi in THF was alive with the presence of lithium phenoxide after stirring at 0℃ for 20 min,compared to 2%under same conditions but without lithium phenoxide.The propagation of polymerization of styrene(St)and methyl methacrylate(MMA)were retarded after adding lithium phenoxide.And by adding more than 10 fold lithium phenoxide,completed conversion was achieved in the polymerization of MMA in THF at 0℃.The lithium phenoxide showed both promoting and inhibiting effects in the polymerization of isoprene(Ip):it promoted the formation of 3,4-structure,while mitigated the formation of 1,2-and 1,4-structures.In general,the polymerization rate of Ip was promoted by lithium phenoxide.展开更多
Acetylcholine(ACh)regulates inflammation viaα7 nicotinic acetylcholine receptor(α7 nAChR).Acetylcholinesterase(AChE),an enzyme hydrolyzing ACh,is expressed in immune cells suggesting non-classical function in inflam...Acetylcholine(ACh)regulates inflammation viaα7 nicotinic acetylcholine receptor(α7 nAChR).Acetylcholinesterase(AChE),an enzyme hydrolyzing ACh,is expressed in immune cells suggesting non-classical function in inflammatory responses.Here,the expression of PRiMA-linked G4 AChE was identified on the surface of macrophages.In lipopolysaccharide-induced inflammatory processes,AChE was upregulated by the binding of NF-κB onto the ACHE promotor.Conversely,the overexpression of G4 AChE inhibited ACh-suppressed cytokine release and cell migration,which was in contrast to that of applied AChE inhibitors.AChEmt,a DNA construct without enzymatic activity,was adopted to identify the protein role of AChE in immune system.Overexpression of G4 AChEmt induced cell migration and inhibited ACh-suppressed cell migration.The co-localization ofα7 nAChR and AChE was found in macrophases,suggesting the potential interaction ofα7 nAChR and AChE.Besides,immunoprecipitation showed a close association ofα7 nAChR and AChE protein in cell membrane.Hence,the novel function of AChE in macrophage by interacting withα7 nAChR was determined.Together with hydrolysis of ACh,AChE plays a direct role in the regulation of inflammatory response.As such,AChE could serve as a novel target to treat age-related diseases by antiinflammatory responses.展开更多
基金support of the Chinese Academy of Sciences through the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA15020100)support by ASI, under the dedicated eXTP agreements and agreement ASI-INAF (Grant No. 2017-14-H.O.)+3 种基金by INAF and INFN under project REDSOXsupport from the Deutsche Zentrum für Luft- und Raumfahrt, the German Aerospce Center (DLR)support of Science Centre (Grant No. 2013/10/M/ST9/00729)support from MINECO (Grant No. ESP2017-82674-R) and FEDER funds
文摘In this paper we present the enhanced X-ray Timing and Polarimetry mission—eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring effects of QED, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics that will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. In particular, its wide field monitoring capabilities will be highly instrumental to detect the electro-magnetic counterparts of gravitational wave sources.The paper provides a detailed description of:(1) the technological and technical aspects, and the expected performance of the instruments of the scientific payload;(2) the elements and functions of the mission, from the spacecraft to the ground segment.
基金Supported by NIH R01 CA169702-01A1(to Zheng L)NIH K23 CA148964-01(to Zheng L)+6 种基金Johns Hopkins School of Medicine Clinical Scientist Award(to Zheng L)Viragh Foundation and the Skip Viragh Pancreatic Cancer Center at Johns Hopkins(to Zheng L)The National Pancreas Foundation(to Zheng L)Lefkofsky Family Foundation(to Zheng L)the NCI SPORE in Gastrointestinal Cancers P50 CA062924(to Zheng L)Lustgarten Foundation(to Zheng L)the Sol Goldman Pancreatic Cancer Center grants(to Zheng L)
文摘Pancreatic ductal adenocarcinoma(PDA)is among the deadliest cancers in the United States and in the world.Late diagnosis,early metastasis and lack of effective therapy are among the reasons why only 6%of patients diagnosed with PDA survive past 5 years.Despite development of targeted therapy against other cancers,little progression has been made in the treatment of PDA.Therefore,there is an urgent need for the development of new treatments.However,in order to proceed with treatments,the complicated biology of PDA needs to be understood first.Interestingly,majority of the tumor volume is not made of malignant epithelial cells but of stroma.In recent years,it has become evident that there is an important interaction between the stromal compartment and the less prevalent malignant cells,leading to cancer progression.The stroma not only serves as a growth promoting source of signals but it is also a physical barrier to drug delivery.Understanding the tumor-stroma signaling leading to development of desmoplastic reaction and tumor progression can lead to the development of therapies to decrease stromal activity and improve drug delivery.In this review,we focus on how the current understanding of biology of the pancreatic tumor microenvironment can be translated into the development of targeted therapy.
基金supported by the National Natural Science Foundation of China(Grant No.81972492)National Science Fund for Young Scholars(Grant No.21904107)+7 种基金Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars(Grant No.LR19C050001)Hangzhou Agriculture and Society Advancement Program(Grant No.20190101A04)Westlake Startup Grantresearch funds from the National Cancer Centre Singapore and Singapore General Hospital,Singaporethe National Key R&D Program of China(Grant No.2016YFC0901704)Zhejiang Innovation Discipline Project of Laboratory Animal Genetic Engineering(Grant No.201510)the Netherlands Cancer Society(Grant No.NKI 2014-6651)The Netherlands Organization for Scientific Research(NWO)-Middelgroot(Grant No.91116017)
文摘To address the increasing need for detecting and validating protein biomarkers in clinical specimens,mass spectrometry(MS)-based targeted proteomic techniques,including the selected reaction monitoring(SRM),parallel reaction monitoring(PRM),and massively parallel dataindependent acquisition(DIA),have been developed.For optimal performance,they require the fragment ion spectra of targeted peptides as prior knowledge.In this report,we describe a MS pipeline and spectral resource to support targeted proteomics studies for human tissue samples.To build the spectral resource,we integrated common open-source MS computational tools to assemble a freely accessible computational workflow based on Docker.We then applied the workflow to generate DPHL,a comprehensive DIA pan-human library,from 1096 data-dependent acquisition(DDA)MS raw files for 16 types of cancer samples.This extensive spectral resource was then applied to a proteomic study of 17 prostate cancer(PCa)patients.Thereafter,PRM validation was applied to a larger study of 57 PCa patients and the differential expression of three proteins in prostate tumor was validated.As a second application,the DPHL spectral resource was applied to a study consisting of plasma samples from 19 diffuse large B cell lymphoma(DLBCL)patients and 18 healthy control subjects.Differentially expressed proteins between DLBCL patients and healthy control subjects were detected by DIA-MS and confirmed by PRM.These data demonstrate that the DPHL supports DIA and PRM MS pipelines for robust protein biomarker discovery.DPHL is freely accessible at https://www.iprox.org/page/project.html?id=IPX0001400000.
基金This work was supported by the Chinese Academy of Sciences,the National Key R&D Program of China,the CAS Center for Excellence in Particle Physics,the Joint Large Scale Scientific Facility Funds of the NSFC and CAS,Wuyi University,and the Tsung-Dao Lee Instiute of Shanghai Jiao Tong University in China,the In stiut National de Physique Nucleaire et de Physique de Particules(IN2P3)in France,the Istituto Nazionale di Fisica Nucleare(INFN)in Italy,the Fond de la Recherche Scintifique(F.R.S-FNRS)and FWO under the"Excellence of Science-EOS"in Belgium,the Conselho Nacional de Desenvolvimento Cientificoce Tecnologico in Brazil,the Agencia Nacional de Investigacion y Desrrollo in Chile,the Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republic,the Deutsche Forschungsgemeinschaft(DFG),the Helmholtz Association,and the Cluster of Exellence PRISMA+in Germany,the Joint Institute of Nuclear Research(JINR),Lomonosov Moscow State University,and Russian Foundation for Basic Research(RFBR)in Russia,the MOST and MOE in Taiwan,the Chu-lalongkorm University and Suranaree University of Technology in Thailand,and the University of aliformia at Irvine in USA.
文摘The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.
基金support from the National Natural Science Foundation of China(21773061,21978095)Innovation Program of Shanghai Municipal Education Commission(15ZZ031)the Fundamental Research Funds for the Central Universities。
文摘Selective oxidation of glycerol provides a feasible route towards the sustainable synthesis of high value-added chemicals.Herein,the hydroxyapatite(HAP)supported palladium(Pd)species were fabricated by impregnation and subsequent calcination.The as-obtained heterogeneous Pd catalyst afforded not only excellent selectivity to glyceric acid(GLA)up to 90%with 59%conversion of glycerol but also good recyclability by using molecular oxygen as an oxidant under mild conditions.The characterization of catalysts indicated that both the surface basicity and Pd sites on the catalyst played a crucial role in promoting glycerol oxidation.Notably,it demonstrated that the presence of the vicinal hydroxyl group of glycerol molecule can assist the oxidation reaction via forming a coordination between the vicinal hydroxyl group and Ca^(2+) sites on HAP-derived catalysts.In this catalytic process,the secondary hydroxyl of glycerol kept untouched and the primary hydroxyl of glycerol was converted into carboxyl group,while the Pd species acted as active centers for cooperatively promoting the subsequent oxidation to generate GLA.Additionally,this catalytic system can be extended widely for the oxidative conversion of other vicinal diols into the corresponding a-hydroxycarboxylic acids selectively.Isotope labeling experiment using H_(2)^(18)O confirmed that H_(2)O not only acted as solvent but also was involved in the catalytic cycles.On the basis of the results,a possible reaction mechanism has been proposed.The HAP-supported Pd catalytic system has been shown to serve as an effective approach for the upgrading of bio-derived vicinal diols to high value-added chemicals.
基金Financial supports for this work from the Nature Science Foundation of China for the Major Program （No. 50933002）, the National High Technology Re-search and Development Program of China （863 Pro-gram, No. 2012AA040306） and Shanghai Leading Academic Discipline Project （No. B502） are gratefully acknowledged.
文摘This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene with the help of a self designed microflow device and characterized by GPC and in situ ^7Li NMR. It was found that n-BuLl tended to form the hexameric-aggregated structure and even to form the huge aggregated structure based on the former. These aggregations of initiators could directly initiate the anionic polymerization and form the su-pramolecule aggregations. The supramolecule aggregations inevitably blocked the diffusion of the monomers to the ion-pairs and resulted in a stationary-conversion platform. Then the aggregators were dissociated completely into equal binary-aggregated species, and the polymerization continued again rapidly before the termination. Tetrahy-drofuran （THF） acted as the electron donator, which could push the electron cloud to Li cation and make the aggre- gated ring of the active species rather loosened and facilitated the monomer to insert in. Therefore, a little THF can greatly promote the anionic polymerization. However, further addition of THF might block the channel between the ion-pairs and decrease the propagation rate. It was also found that the aggregated structure of the active species during the anionic polymerization only depends on the initiator aggregations which were formed before the polym-erization.
基金financial support from European Funds through COMPETENational Funds through the Portuguese Foundation for Science and Technology(FCT)within projects PTDC/AGR-FOR/3807/2012-FCOMP-01-0124-FEDER-027979 and PEst-C/MAR/LA0017/2013+4 种基金supported by National Science Foundation Grant DBI 1046115supported by FFG,BMWFJ,BMVIT,ZIT,Zukunftsstiftung Tirol,and Land Steiermark within the Austrian COMET program FFG Grant 824186Financial support to JP was partially provided by the Polish Ministry of Science and Higher Education(MNiSW),grant no.NN303_548839financial support from FAPEMIG and CNPqfunded by the Government of Canada through Genome Canada and the Ontario Genomics Institute through the Biomonitoring 2.0 project(OGI-050).
文摘Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours.These taxa often have complex and poorly understood life cycles,lack observable,discriminatory morphological characters,and may not be amenable to in vitro culturing.As a result,species identification is frequently difficult.Molecular(DNA sequence)data have emerged as crucial information for the taxonomic identification of plant pathogenic fungi,with the nuclear ribosomal internal transcribed spacer(ITS)region being the most popular marker.However,international nucleotide sequence databases are accumulating numerous sequences of compromised or low-resolution taxonomic annotations and substandard technical quality,making their use in the molecular identification of plant pathogenic fungi problematic.Here we report on a concerted effort to identify high-quality reference sequences for various plant pathogenic fungi and to re-annotate incorrectly or insufficiently annotated public ITS sequences from these fungal lineages.A third objective was to enrich the sequences with geographical and ecological metadata.The results-a total of 31,954 changes-are incorporated in and made available through the UNITE database for molecular identification of fungi(http://unite.ut.ee),including standalone FASTA files of sequence data for local BLAST searches,use in the next-generation sequencing analysis platforms QIIME and mothur,and related applications.The present initiative is just a beginning to cover the wide spectrum of plant pathogenic fungi,and we invite all researchers with pertinent expertise to join the annotation effort.
基金support from ERC Starting (Grant No. 639217 CSINEUTRONSTAR)support from a Netherlands Organization for Scientific Research (NWO) Vidi Fellowship+2 种基金suported by the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Global Fellowship (Grant No. 703916)supported in part by the DFG through Grant SFB 1245 and the ERC (Grant No. 307986 STRONGINT)support of the Chinese Academy of Sciences through the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA15020100)
文摘In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry(eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to be launched in the mid 2020 s.
基金The authors are grateful for the financial support from the National Natural Science Foundation of China （Nos. 50933002, 51373052, 51573043）.
文摘It still remains a concern to break through the bottlenecks of anionic polymerization of polar monomers, such as side reactions, low conver- sion and low temperature （-78 ℃）. In this work, potassium tert-butoxide （t-BuOK） was chosen to initiate the anionic polymerization of 2-ethylhexyl methacrylate （EHMA） in tetrahydrofuran. The conversions were above 99% at 0 or 30 ℃, and above 95% at 60 ℃ without side reaction inhibitors. The high conversions implied t-BuOK could suppress the side reactions. A series of block copolymers of EHMA, n-hexyl methacrylate （HMA） and methyl methacrylate （MMA） were further synthesized at 0 ℃, and the conversions were all above 99%. The GPC and IH NMR results confirmed the successful synthesis of the block copolymers. The molecular size of monomer and the state of t-BuOK （free ion pairs or aggregates） remarkably affected the polymerization rates and the molecular structures of the products. The DMA results indicated that the glass transition temperatures of PEHMA or PHMA block and PMMA block were 20 ℃ and 60 ℃, respectively, which deviated from -2 ℃ and 105 ℃ of homopolymer, respectively, due to the partial com- patibility of the blocks. This work explored a route of the anionic polymerization of polar monomers at room temperature.
基金Financial supports for this work from the Natural Science Foundation of China for the Major Program(No.50933002)the National High Technology Research and Development Program of China(863 Program,No.2012AA040306)Shanghai Leading Academic Discipline Project(No.B502)are gratefully acknowledged.
文摘This work confirmed a novel ligand in the anionic polymerization,lithium phenoxide,which helped to improve the controllability of the polymerization.The stability of n-BuLi against THF at 0℃ was effectively improved by adding lithium phenoxide.More than 60%n-BuLi in THF was alive with the presence of lithium phenoxide after stirring at 0℃ for 20 min,compared to 2%under same conditions but without lithium phenoxide.The propagation of polymerization of styrene(St)and methyl methacrylate(MMA)were retarded after adding lithium phenoxide.And by adding more than 10 fold lithium phenoxide,completed conversion was achieved in the polymerization of MMA in THF at 0℃.The lithium phenoxide showed both promoting and inhibiting effects in the polymerization of isoprene(Ip):it promoted the formation of 3,4-structure,while mitigated the formation of 1,2-and 1,4-structures.In general,the polymerization rate of Ip was promoted by lithium phenoxide.
基金supported by Shenzhen Science and Technology Committee Research Grant(JCYJ20170413173747440,ZDSYS 201707281432317,JCYJ20180306174903174,CKFW2016082916015476,China)China Post-doctoral Science Foundation(2019M653087)+3 种基金Zhongshan Municipal Bureau of Science and Technology(ZSST20SC03,China)Guangzhou Science and Technology Committee Research Grant(GZSTI16SC02 and GZSTI17SC02,China)Hong Kong RGC Theme-based Research Scheme(T13-607/12R,China)Hong Kong Innovation Technology Fund(UIM/340,UIM/385,ITS/500/18FP,TCPD/17e9,PD18SC01 and HMRF18SC06,China)
文摘Acetylcholine(ACh)regulates inflammation viaα7 nicotinic acetylcholine receptor(α7 nAChR).Acetylcholinesterase(AChE),an enzyme hydrolyzing ACh,is expressed in immune cells suggesting non-classical function in inflammatory responses.Here,the expression of PRiMA-linked G4 AChE was identified on the surface of macrophages.In lipopolysaccharide-induced inflammatory processes,AChE was upregulated by the binding of NF-κB onto the ACHE promotor.Conversely,the overexpression of G4 AChE inhibited ACh-suppressed cytokine release and cell migration,which was in contrast to that of applied AChE inhibitors.AChEmt,a DNA construct without enzymatic activity,was adopted to identify the protein role of AChE in immune system.Overexpression of G4 AChEmt induced cell migration and inhibited ACh-suppressed cell migration.The co-localization ofα7 nAChR and AChE was found in macrophases,suggesting the potential interaction ofα7 nAChR and AChE.Besides,immunoprecipitation showed a close association ofα7 nAChR and AChE protein in cell membrane.Hence,the novel function of AChE in macrophage by interacting withα7 nAChR was determined.Together with hydrolysis of ACh,AChE plays a direct role in the regulation of inflammatory response.As such,AChE could serve as a novel target to treat age-related diseases by antiinflammatory responses.
