Cellulose is the most abundant natural polymer material in the world.Cellulose is diffi-cult to dissolve because it contains a large number of inter molecular hydrogen bonds.Therefore,the modification of natural cellu...Cellulose is the most abundant natural polymer material in the world.Cellulose is diffi-cult to dissolve because it contains a large number of inter molecular hydrogen bonds.Therefore,the modification of natural cellulose by chemical oxidation can expand its application field.The oxidation process of cellulose is focused on,the oxidation methods and research progress of cellulose are introduced,and further development direction of oxidized cellulose is prospected.展开更多
Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cat...Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cathodes is accompanied by substantial safety and cycle-life obstacles. The major issues of Ni-rich cathodes at high working potentials are originated from the unstable cathode-electrolyte interface, while the underlying mechanism of parasitic reactions towards surface reconstructions of cathode materials is not well understood. In this work, we controlled the Li_(2)CO_(3) impurity content on LiNi_(0.83)Mn_(0.1)Co_(0.07)O_(2) cathodes using air, tank-air, and O_(2) synthesis environments. Home-built high-precision leakage current and on-line electrochemical mass spectroscopy experiments verify that Li_(2)CO_(3) impurity is a significant promoter of parasitic reactions on Ni-rich cathodes. The rate of parasitic reactions is strongly correlated to Li_(2)CO_(3) content and severe performance deterioration of Ni83 cathodes.The post-mortem characterizations via high-resolution transition electron microscope and X-ray photoelectron spectroscopy depth profiles reveal that parasitic reactions promote more Ni reduction and O deficiency and even rock-salt phase transformation at the surface of cathode materials. Our observation suggests that surface reconstructions have a strong affiliation to parasitic reactions that create chemically acidic environment to etch away the lattice oxygen and offer the electrical charge to reduce the valence state of transition metal. Thus, this study advances our understanding on surface reconstructions of Nirich cathodes and prepares us for searching for rational strategies.展开更多
Based on the hot tearing index|△T/△(fs)^(0.5)|recently proposed by Kou and the thermodynamic calculations of Pandat software,Al,Cu,and Mn elements were picked up and their influence on hot tearing susceptibility of ...Based on the hot tearing index|△T/△(fs)^(0.5)|recently proposed by Kou and the thermodynamic calculations of Pandat software,Al,Cu,and Mn elements were picked up and their influence on hot tearing susceptibility of Mg-x Zn(x=6,8,10,wt%)alloys was studied by experiments.The results indicate that Al addition can significantly reduce the hot tearing susceptibility of Mg-Zn alloys.Either 0.5Cu or 0.3Mn addition individually can reduce the HTS of the Mg-6Zn-(1,4)Al alloys,while adding together increases the susceptibility.The addition of 0.5Cu and 0.3Mn both individually and together increases the HTS of Mg-8/10Zn-1Al alloys.Based on the experimental and calculation results,the index can be modified to|△T/△(fs)^(0.5)|(d)^(2)for more accurate prediction on the hot tearing resistance of Mg-Zn based alloys.Grain refinement significantly improves the hot tearing resistance of Mg-Zn based alloys.展开更多
Metal-sulfur batteries are recognized as a promising candidate for next generation electrochemical energy storage systems owing to their high theoretical energy density,low cost and environmental friendliness.However,...Metal-sulfur batteries are recognized as a promising candidate for next generation electrochemical energy storage systems owing to their high theoretical energy density,low cost and environmental friendliness.However,sluggish redox kinetics of sulfur species and the shuttle effect lead to large polarization and severe capacity decay.Numerous approaches from physical barrier,chemical adsorption strategies to electrocatalysts have been tried to solve these issues and pushed the rate and cycle performance of sulfur electrodes to higher levels.Most recently,single-atom catalysts(SACs)with high catalytic efficiency have been introduced into metal-sulfur systems to achieve fast redox kinetics of sulfur conversion.In this review,we systematically summarize the current progress on SACs for sulfur electrodes from aspects of synthesis,characterization and electrochemical performance.Challenges and potential solutions for designing SACs for high-performance sulfur electrodes are discussed.展开更多
A low-cost and easily prepared manganese carbonate(Mn CO_3) has been synthesized for catalytic conversion of 5-hydroxymethylfurfural(5-HMF) to 2,5-diformylfuran(DFF). The properties and morphology of the manganese car...A low-cost and easily prepared manganese carbonate(Mn CO_3) has been synthesized for catalytic conversion of 5-hydroxymethylfurfural(5-HMF) to 2,5-diformylfuran(DFF). The properties and morphology of the manganese carbonate were measured by SEM,XRD,TGA,BET and XPS. In this method,no harsh reaction conditions were required,and it was a simple and green process for the oxidation of 5-HMF into DFF. To achieve an optimum DFF yield,different reaction conditions,including reaction temperature,reaction time,catalyst amount,and solvents were investigated. Results from the experiments indicated that the highest DFF yield of 86.9% was obtained at 120 °C under atmospheric oxygen pressure after 6h. Finally,Mn CO_3 could be used at least five times with considerable stability.展开更多
Strigolactones are plant hormones with multiple functions, including regulating various aspects of plant architecture such as shoot branching, facilitating the colonization of plant roots by arbuscular mycorrhizal fun...Strigolactones are plant hormones with multiple functions, including regulating various aspects of plant architecture such as shoot branching, facilitating the colonization of plant roots by arbuscular mycorrhizal fungi, and acting as seed germination stimulants for certain parasitic plants of the family Orobanchaceae. The obligate parasitic species Phelipanche aegyptiaca and Striga hermonthica require strigolactones for germination, while the facultative parasite Triphysaria versicolor does not. It has been hypothesized that P. aegyptiaca and S. hermonthica would have undergone evolutionary loss of strigolactone biosynthesis as a part of their mechanism to enable specific detection of exogenous strigolactones. We analyzed the transcriptomes of P. aegyptiaca, S. hermonthica and T. versicolor and identified genes known to act in strigolactone synthesis (D27, CCD7, CCD8, and MAX1), perception (MAX2 and D14) and transport (PDR12). These genes were then analyzed to assess likelihood of function. Transcripts of all strigolactone-related genes were found in P. aegyptiaca and S. hermonthica, and evidence points to their encoding functional proteins. Gene open reading frames were consistent with homologs from Arabidopsis and other strigolactone-producing plants, and all genes were expressed in parasite tissues. In general, the genes related to strigolactone synthesis and perception appeared to be evolving under codon-based selective constraints in strigolactone-dependent species. Bioassays of S. hermonthica root extracts indicated the presence of strigolactone class stimulants on germination of P. aegyptiaca seeds. Taken together, these results indicate that Phelipanche aegyptiaca and S. hermonthica have retained functional genes involved in strigolactone biosynthesis, suggesting that the parasites use both endogenous and exogenous strigolactones and have mechanisms to differentiate the two.展开更多
Room temperature sodium–sulfur(RT Na-S)battery with high theoretical energy density and low cost has spurred tremendous interest,which is recognized as an ideal candidate for large-scale energy storage applications.H...Room temperature sodium–sulfur(RT Na-S)battery with high theoretical energy density and low cost has spurred tremendous interest,which is recognized as an ideal candidate for large-scale energy storage applications.However,serious sodium polysulfide shutting and sluggish reaction kinetics lead to rapid capacity decay and poor Coulombic efficiency.Recently,catalytic materials capable of adsorbing and catalyzing the conversion of polysulfides are profiled as a promising method to improve electrochemical performance.In this review,the research progress is summarized that the application of catalytic materials in RT Na-S battery.For the role of catalyst on the conversion of sulfur species,specific attention is focused on the influence factors of reaction rate during different redox processes.Various catalytic materials based on lightweight and high conductive carbon materials,including heteroatom-doped carbon,metals and metal compounds,single-atom and heterostructure,promote the reaction kinetic via lowered energy barrier and accelerated charge transfer.Additionally,the adsorption capacity of the catalytic materials is the key to the catalytic effect.Particular attention to the interaction between polysulfides and sulfur host materials is necessary for the exploration of catalytic mechanism.Lastly,the challenges and outlooks toward the desired design of efficient catalytic materials for RT Na-S battery are discussed.展开更多
Immunotherapy has great promise in improving malignant tumor treatment.However,the efficacy of existing strategies is often limited by the immunosuppressive environment.Here,we demonstrate an in situ bionic immunoacti...Immunotherapy has great promise in improving malignant tumor treatment.However,the efficacy of existing strategies is often limited by the immunosuppressive environment.Here,we demonstrate an in situ bionic immunoactivator,PLT-Bec1/DTA-1,with possessed natural advantages of platelets for tumor recruitment and activation,on which DTA-1(CD357 monoclonal antibody)and Bec1 were tethered as combined immune boosters.PLT-Bec1/DTA-1,as a self-triggered release repository,can deliver the pre-tethered Bec1 and DTA-1 deeply through the secretion of platelet microparticles(PMPs),thereby cooperate tacitly and exhibit superiority in immune activation of dendritic cells(DCs)and T cells via autophagy inducibility,coupled with glucocorticoid-induced tumor necrosis factor receptor(GITR)-triggered T_(Reg) suppression,remodeled the immunosuppressive network of tumor microenvironment.PLT-Bec1/DTA-1 promoted antigen presentation and T cell proliferation,and alleviated the low activity state of bone marrow-derived dendritic cells(BMDCs)in tumor suppressive environment.PLT-Bec1/DTA-1 inhibited tumor recurrence(5-and 13-fold lower of control group in tumor volume)and CD8^(+)T/T_(Reg) ratio(6.3-and 8.8-fold vs.control group)in mouse tumor model after intravenous or subcutaneous administration.Also,PLT-Bec1/DTA-1 prevented tumor colonization in lung through in situ immune activation,and was slightly superior to the combined of Bec1 and PD-L1.Our findings highlight the promise of delivering immunostimulatory payloads via bionic carriers,eliciting automatic in situ activation of effector immune cells in tumor microenvironment for tumor eradication.All these results provide promising prospects into the application of immunoactivator in improving cancer synergistic immunotherapy to overcome the bottlenecks in clinic.展开更多
Mechanochemistry has been recognized as an efficient and sustainable methodology to provide a unique driven force and reaction environments under ambient and neat conditions for the construction of functionalized mate...Mechanochemistry has been recognized as an efficient and sustainable methodology to provide a unique driven force and reaction environments under ambient and neat conditions for the construction of functionalized materials possessing promising properties.Among them,highly porous conjugated scaffolds with attractive electronic conductivities and high surface areas are one of the representative categories exhibiting diverse taskspecific applications,especially in electrochemical energy storage.In recent years,the mechanochemistry-driven procedures have been deployed to construct conjugated scaffolds with engineered structures and properties leveraging the tunability in chemical structures of building blocks and polymerization capability of diverse catalysts.Therefore,a thorough review of related works is required to gain an in-depth understanding of the mechanochemical synthesis procedure and property-performance relationship of the as-produced conjugated scaffolds.Herein,the mechanochemistry-driven construction of conjugated porous networks(CPNs),the carbon-based materials(e.g.,graphite and graphyne),and carbon supported single atom catalysts(CS-SACs)are discussed and summarized.The electrochemical performance of the afforded conductive scaffolds as electrode materials in supercapacitors and alkali-ion batteries is elucidated.Finally,the challenges and potential opportunities related to the construction of conjugated scaffolds driven by mechanochemistry are also discussed and concluded.展开更多
There is currently a huge worldwide demand for donor kidneys for organ transplantation.Consequently,numerous marginal donor kidneys,such as kidneys with microthrombi,are used to save patients'lives.While some stud...There is currently a huge worldwide demand for donor kidneys for organ transplantation.Consequently,numerous marginal donor kidneys,such as kidneys with microthrombi,are used to save patients'lives.While some studies have shown an association between the presence of microthrombi in donor kidneys and an increased risk for delayed graft function(DGF)(McCall et al.,2003;Gao et al.,2019),other studies have demonstrated that microthrombi negatively impact the rate of DGF(Batra et al.,2016;Hansen et al.,2018),but not graft survival rate(McCall et al.,2003;Batra et al.,2016;Gao et al.,2019).In contrast,Hansen et al.(2018)concluded that fibrin thrombi were not only associated with reduced graft function six months posttransplantation but also with increased graft loss within the first year of transplantation.On the other hand,Batra et al.(2016)found no significant differences in the DGF rate or one-year graft function between recipients in diffuse and focal microthrombi groups.To date,however,the overall influence of donor kidney microthrombi and the degree of influence on prognosis remain controversial,necessitating further research.展开更多
Organic moieties-derived salts with permanent porosity and polarized channels have shown unique features and attractive performance in the field of adsorption,separation,and conduction.However,state-of-the-art organic...Organic moieties-derived salts with permanent porosity and polarized channels have shown unique features and attractive performance in the field of adsorption,separation,and conduction.However,state-of-the-art organic salts generally rely on ionic interaction and hydrogen bonding formation to maintain the porous channels.The synthesis of organic moiety-derived saltswith permanent accessible pores even after removal of the trapped guest molecules,and without the constraint of hydrogen bonding formation still remains a great challenge.Herein,we present an expeditious construction pathway to generate hierarchically nanoporous barium salts without hydrogen bonding formation.The strong ionic interaction of the bariumcation and sulfonate anions led to rapid reaction equilibrium(∼2 min),affording diverse barium-derived ionic polymer(Ba-IP)with permanent porosity and highly polarized channels.The produced Ba-IP materials with abundant cations and anions displayed high CO_(2)/N2 and CO_(2)/CH_(4)separation performance,with the selectivities reaching up to 89.5 and 280,respectively,at 273 K,surpassingmost of the organic polymers functionalized by ionic moieties.展开更多
Acute myocardial infarction(AMI)remains a dominant origin of morbidity,mortality and disability worldwide.Increases in reactive oxygen species(ROS)are key contributor to excessive cardiac injury after AMI.Here we deve...Acute myocardial infarction(AMI)remains a dominant origin of morbidity,mortality and disability worldwide.Increases in reactive oxygen species(ROS)are key contributor to excessive cardiac injury after AMI.Here we developed an immobilized enzyme with Superoxide Dismutase(SOD)activity cross-link with Zr-based metal-organic framework(ZrMOF)(SOD-ZrMOF)for mitigate ROS-caused injury.In vitro and in vivo evidence indicates that SOD-ZrMOF exhibits excellent biocompatibility.By efficiently scavenging ROS and suppressing oxidative stress,SOD-ZrMOF can protect the function of mitochondria,reduce cell death and alleviate inflammation.More excitingly,long-term study using an animal model of AMI demonstrated that SOD-ZrMOF can reduce the infarct area,protect cardiac function,promote angiogenesis and inhibit pathological myocardial remodeling.Therefore,SOD-ZrMOF holds great potential as an efficacious and safe nanomaterial treatment for AMI.展开更多
Fluorinated porous organic networks(F-PONs)have demonstrated unique properties and applications,but approaches capable of affording F-PONs with high fluorine content and robust nanoporous architecture under metal-free...Fluorinated porous organic networks(F-PONs)have demonstrated unique properties and applications,but approaches capable of affording F-PONs with high fluorine content and robust nanoporous architecture under metal-free and easy handling conditions are still rarely reported.Herein,using polydivinylbenzene(PDVB)as an easily available precursor,a novel and straightforward approach was developed to afford F-PONs via a dehydrative Friedel-Crafts reaction using perfluorinated benzylic alcohols as the cross-linking agent promoted by Bronsted acid(trifluoromethanesulfonic acid).The afforded material(F-PDVB)featured high fluorine content(22 at.%),large surface area(771 m^(2)·g^(-1)),and good chemical/thermal stability,rendering them as promising candidates for the adsorption of CO_(2),hydrocarbons,fluorocarbons,and chlorofluorocarbons,with weight capacities up to 520 wt.%being achieved.This simple methodology can be extended to fabricate fluorinated hyper-crosslinked polymers(F-HCPs)from rigid aromatic monomers.The progress made in this work will open new opportunities to further expand the involvement of fluorinated materials in large scale applications.展开更多
High-entropy alloy nanoparticles(HEA-NPs)are highly underutilized in heterogeneous catalysis due to the absence of a reliable,sustainable,and facile synthetic method.Herein,we report a facile synthesis of HEA nanocata...High-entropy alloy nanoparticles(HEA-NPs)are highly underutilized in heterogeneous catalysis due to the absence of a reliable,sustainable,and facile synthetic method.Herein,we report a facile synthesis of HEA nanocatalysts realized via an ultrasounddriven wet chemistry method promoted by alcoholic ionic liquids(AILs).Owing to the intrinsic reducing ability of the hydroxyl group,AILs were synthesized and utilized as environmentally friendly alternatives to conventional reducing agents and volatile organic solvents in the synthetic process.Under high-intensity ultrasound irradiation,Au^(3+),Pd^(2+),Pt^(2+),Rh^(3+),and Ru^(3+)ions were coreduced and transformed into single-phase HEA(AuPdPtRhRu)nanocrystals without calcination.Characterization results reveal that the as-synthesized nanocrystals are composed of elements of Au,Pd,Pt,Rh,and Ru as expected.Compared to the monometallic counterparts such as Pd-NPs,the carbon-supported HEA nanocatalysts show superior catalytic performance for selective hydrogenation of phenol to cyclohexanone in terms of yield and selectivity.Our synthetic strategy provides an improved and facile methodology for the sustainable synthesis of multicomponent alloys for catalysis and other applications.展开更多
1.Introduction Man-made perturbations over emissions of greenhouse gas(GHG)bring tremendous negative impacts on the survival environment[1].CO_(2)accounts for~75%of global GHG impacts with others mainly composed of N_...1.Introduction Man-made perturbations over emissions of greenhouse gas(GHG)bring tremendous negative impacts on the survival environment[1].CO_(2)accounts for~75%of global GHG impacts with others mainly composed of N_(2)O,CH_(4),and small fluorinated gas molecules[2].Deployment of“negative emission”technologies via direct air capture(DAC)of CO_(2)by engineered chemical reactions represents one of the most promising and distinct pathways to limit and alleviate the global warming trend[3].展开更多
文摘Cellulose is the most abundant natural polymer material in the world.Cellulose is diffi-cult to dissolve because it contains a large number of inter molecular hydrogen bonds.Therefore,the modification of natural cellulose by chemical oxidation can expand its application field.The oxidation process of cellulose is focused on,the oxidation methods and research progress of cellulose are introduced,and further development direction of oxidized cellulose is prospected.
基金supported by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Officesupported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office, under Contract No. DE-SC0012704+1 种基金supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract DE-AC02-06CH11357supported by the Vehicle Technologies Office of the U.S. Department of Energy。
文摘Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cathodes is accompanied by substantial safety and cycle-life obstacles. The major issues of Ni-rich cathodes at high working potentials are originated from the unstable cathode-electrolyte interface, while the underlying mechanism of parasitic reactions towards surface reconstructions of cathode materials is not well understood. In this work, we controlled the Li_(2)CO_(3) impurity content on LiNi_(0.83)Mn_(0.1)Co_(0.07)O_(2) cathodes using air, tank-air, and O_(2) synthesis environments. Home-built high-precision leakage current and on-line electrochemical mass spectroscopy experiments verify that Li_(2)CO_(3) impurity is a significant promoter of parasitic reactions on Ni-rich cathodes. The rate of parasitic reactions is strongly correlated to Li_(2)CO_(3) content and severe performance deterioration of Ni83 cathodes.The post-mortem characterizations via high-resolution transition electron microscope and X-ray photoelectron spectroscopy depth profiles reveal that parasitic reactions promote more Ni reduction and O deficiency and even rock-salt phase transformation at the surface of cathode materials. Our observation suggests that surface reconstructions have a strong affiliation to parasitic reactions that create chemically acidic environment to etch away the lattice oxygen and offer the electrical charge to reduce the valence state of transition metal. Thus, this study advances our understanding on surface reconstructions of Nirich cathodes and prepares us for searching for rational strategies.
基金supported by the National Key Research and Development Program of China(2016YFB0701204)Shang-hai Rising-Star Program(15QB1402700)Special Fund of Jiangsu Province for the Transformation of Scientific and Technological Achievements(BA2016039).
文摘Based on the hot tearing index|△T/△(fs)^(0.5)|recently proposed by Kou and the thermodynamic calculations of Pandat software,Al,Cu,and Mn elements were picked up and their influence on hot tearing susceptibility of Mg-x Zn(x=6,8,10,wt%)alloys was studied by experiments.The results indicate that Al addition can significantly reduce the hot tearing susceptibility of Mg-Zn alloys.Either 0.5Cu or 0.3Mn addition individually can reduce the HTS of the Mg-6Zn-(1,4)Al alloys,while adding together increases the susceptibility.The addition of 0.5Cu and 0.3Mn both individually and together increases the HTS of Mg-8/10Zn-1Al alloys.Based on the experimental and calculation results,the index can be modified to|△T/△(fs)^(0.5)|(d)^(2)for more accurate prediction on the hot tearing resistance of Mg-Zn based alloys.Grain refinement significantly improves the hot tearing resistance of Mg-Zn based alloys.
基金supported by the National Natural Science Foundation of China(No.51972313,51525206 and 51927803)the Ministry of Science and Technology of China(2016YFA0200100 and 2016YFB0100100)+7 种基金the Strategic Priority Research Program of Chinese Academy of Science(No.XDA22010602)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y201942)the Key Research Program of Chinese Academy of Sciences(No.KGZD-EW-T06)the Special Projects of the Central Government in Guidance of Local Science and Technology Development(No.2020JH6/10500024)the Program for Guangdong Introducing Innovative and Entrepreneurial Teamsthe Development and Reform Commission of Shenzhen Municipality for the development of the “Low-Dimensional Materials and Devices”discipline and the EconomicThe Bureau of Industry and Information Technology of Shenzhen for the“2017 Graphene Manufacturing Innovation Center Project”(No.201901171523)China Petrochemical Cooperation(No.218025)。
文摘Metal-sulfur batteries are recognized as a promising candidate for next generation electrochemical energy storage systems owing to their high theoretical energy density,low cost and environmental friendliness.However,sluggish redox kinetics of sulfur species and the shuttle effect lead to large polarization and severe capacity decay.Numerous approaches from physical barrier,chemical adsorption strategies to electrocatalysts have been tried to solve these issues and pushed the rate and cycle performance of sulfur electrodes to higher levels.Most recently,single-atom catalysts(SACs)with high catalytic efficiency have been introduced into metal-sulfur systems to achieve fast redox kinetics of sulfur conversion.In this review,we systematically summarize the current progress on SACs for sulfur electrodes from aspects of synthesis,characterization and electrochemical performance.Challenges and potential solutions for designing SACs for high-performance sulfur electrodes are discussed.
基金supported by the Natural Science Foundation of Tianjin (No. 16JCYBJC19600)the National Natural Science Foundation of China (No. 21621004)the Beiyang Young Scholar of Tianjin University (2012)
文摘A low-cost and easily prepared manganese carbonate(Mn CO_3) has been synthesized for catalytic conversion of 5-hydroxymethylfurfural(5-HMF) to 2,5-diformylfuran(DFF). The properties and morphology of the manganese carbonate were measured by SEM,XRD,TGA,BET and XPS. In this method,no harsh reaction conditions were required,and it was a simple and green process for the oxidation of 5-HMF into DFF. To achieve an optimum DFF yield,different reaction conditions,including reaction temperature,reaction time,catalyst amount,and solvents were investigated. Results from the experiments indicated that the highest DFF yield of 86.9% was obtained at 120 °C under atmospheric oxygen pressure after 6h. Finally,Mn CO_3 could be used at least five times with considerable stability.
文摘Strigolactones are plant hormones with multiple functions, including regulating various aspects of plant architecture such as shoot branching, facilitating the colonization of plant roots by arbuscular mycorrhizal fungi, and acting as seed germination stimulants for certain parasitic plants of the family Orobanchaceae. The obligate parasitic species Phelipanche aegyptiaca and Striga hermonthica require strigolactones for germination, while the facultative parasite Triphysaria versicolor does not. It has been hypothesized that P. aegyptiaca and S. hermonthica would have undergone evolutionary loss of strigolactone biosynthesis as a part of their mechanism to enable specific detection of exogenous strigolactones. We analyzed the transcriptomes of P. aegyptiaca, S. hermonthica and T. versicolor and identified genes known to act in strigolactone synthesis (D27, CCD7, CCD8, and MAX1), perception (MAX2 and D14) and transport (PDR12). These genes were then analyzed to assess likelihood of function. Transcripts of all strigolactone-related genes were found in P. aegyptiaca and S. hermonthica, and evidence points to their encoding functional proteins. Gene open reading frames were consistent with homologs from Arabidopsis and other strigolactone-producing plants, and all genes were expressed in parasite tissues. In general, the genes related to strigolactone synthesis and perception appeared to be evolving under codon-based selective constraints in strigolactone-dependent species. Bioassays of S. hermonthica root extracts indicated the presence of strigolactone class stimulants on germination of P. aegyptiaca seeds. Taken together, these results indicate that Phelipanche aegyptiaca and S. hermonthica have retained functional genes involved in strigolactone biosynthesis, suggesting that the parasites use both endogenous and exogenous strigolactones and have mechanisms to differentiate the two.
基金financial support from National Natural Science Foundation of China(Nos.52020105010,51972313,51927803,52072378,51902316 and 51525206)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010602)+2 种基金LiaoNing Revitalization Talents Program(No.XLYC1908015)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y201942)the Special Projects of the Central Government in Guidance of Local Science and Technology Development(No.2020JH6/10500024)。
文摘Room temperature sodium–sulfur(RT Na-S)battery with high theoretical energy density and low cost has spurred tremendous interest,which is recognized as an ideal candidate for large-scale energy storage applications.However,serious sodium polysulfide shutting and sluggish reaction kinetics lead to rapid capacity decay and poor Coulombic efficiency.Recently,catalytic materials capable of adsorbing and catalyzing the conversion of polysulfides are profiled as a promising method to improve electrochemical performance.In this review,the research progress is summarized that the application of catalytic materials in RT Na-S battery.For the role of catalyst on the conversion of sulfur species,specific attention is focused on the influence factors of reaction rate during different redox processes.Various catalytic materials based on lightweight and high conductive carbon materials,including heteroatom-doped carbon,metals and metal compounds,single-atom and heterostructure,promote the reaction kinetic via lowered energy barrier and accelerated charge transfer.Additionally,the adsorption capacity of the catalytic materials is the key to the catalytic effect.Particular attention to the interaction between polysulfides and sulfur host materials is necessary for the exploration of catalytic mechanism.Lastly,the challenges and outlooks toward the desired design of efficient catalytic materials for RT Na-S battery are discussed.
基金We would like to thank the National Natural Science Foundation of China(No.81973258)the Beijing Natural Science Foundation(Nos.L202044,7202092)for funding this work.
文摘Immunotherapy has great promise in improving malignant tumor treatment.However,the efficacy of existing strategies is often limited by the immunosuppressive environment.Here,we demonstrate an in situ bionic immunoactivator,PLT-Bec1/DTA-1,with possessed natural advantages of platelets for tumor recruitment and activation,on which DTA-1(CD357 monoclonal antibody)and Bec1 were tethered as combined immune boosters.PLT-Bec1/DTA-1,as a self-triggered release repository,can deliver the pre-tethered Bec1 and DTA-1 deeply through the secretion of platelet microparticles(PMPs),thereby cooperate tacitly and exhibit superiority in immune activation of dendritic cells(DCs)and T cells via autophagy inducibility,coupled with glucocorticoid-induced tumor necrosis factor receptor(GITR)-triggered T_(Reg) suppression,remodeled the immunosuppressive network of tumor microenvironment.PLT-Bec1/DTA-1 promoted antigen presentation and T cell proliferation,and alleviated the low activity state of bone marrow-derived dendritic cells(BMDCs)in tumor suppressive environment.PLT-Bec1/DTA-1 inhibited tumor recurrence(5-and 13-fold lower of control group in tumor volume)and CD8^(+)T/T_(Reg) ratio(6.3-and 8.8-fold vs.control group)in mouse tumor model after intravenous or subcutaneous administration.Also,PLT-Bec1/DTA-1 prevented tumor colonization in lung through in situ immune activation,and was slightly superior to the combined of Bec1 and PD-L1.Our findings highlight the promise of delivering immunostimulatory payloads via bionic carriers,eliciting automatic in situ activation of effector immune cells in tumor microenvironment for tumor eradication.All these results provide promising prospects into the application of immunoactivator in improving cancer synergistic immunotherapy to overcome the bottlenecks in clinic.
基金supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,Materials Sciences,and Engineering Division
文摘Mechanochemistry has been recognized as an efficient and sustainable methodology to provide a unique driven force and reaction environments under ambient and neat conditions for the construction of functionalized materials possessing promising properties.Among them,highly porous conjugated scaffolds with attractive electronic conductivities and high surface areas are one of the representative categories exhibiting diverse taskspecific applications,especially in electrochemical energy storage.In recent years,the mechanochemistry-driven procedures have been deployed to construct conjugated scaffolds with engineered structures and properties leveraging the tunability in chemical structures of building blocks and polymerization capability of diverse catalysts.Therefore,a thorough review of related works is required to gain an in-depth understanding of the mechanochemical synthesis procedure and property-performance relationship of the as-produced conjugated scaffolds.Herein,the mechanochemistry-driven construction of conjugated porous networks(CPNs),the carbon-based materials(e.g.,graphite and graphyne),and carbon supported single atom catalysts(CS-SACs)are discussed and summarized.The electrochemical performance of the afforded conductive scaffolds as electrode materials in supercapacitors and alkali-ion batteries is elucidated.Finally,the challenges and potential opportunities related to the construction of conjugated scaffolds driven by mechanochemistry are also discussed and concluded.
基金supported by the Science and Technology Department of Zhejiang Province(No.2019C03029)the National Natural Science Foundation of China(Nos.82070766,81870510,and U21A20350)the Bethune Charitable Foundation(No.GX2019010112),China.
文摘There is currently a huge worldwide demand for donor kidneys for organ transplantation.Consequently,numerous marginal donor kidneys,such as kidneys with microthrombi,are used to save patients'lives.While some studies have shown an association between the presence of microthrombi in donor kidneys and an increased risk for delayed graft function(DGF)(McCall et al.,2003;Gao et al.,2019),other studies have demonstrated that microthrombi negatively impact the rate of DGF(Batra et al.,2016;Hansen et al.,2018),but not graft survival rate(McCall et al.,2003;Batra et al.,2016;Gao et al.,2019).In contrast,Hansen et al.(2018)concluded that fibrin thrombi were not only associated with reduced graft function six months posttransplantation but also with increased graft loss within the first year of transplantation.On the other hand,Batra et al.(2016)found no significant differences in the DGF rate or one-year graft function between recipients in diffuse and focal microthrombi groups.To date,however,the overall influence of donor kidney microthrombi and the degree of influence on prognosis remain controversial,necessitating further research.
基金The research was supported financially by the Division of Chemical Sciences,Geosciences,and Biosciences,Office of Basic Energy Sciences,US Department of Energy.
文摘Organic moieties-derived salts with permanent porosity and polarized channels have shown unique features and attractive performance in the field of adsorption,separation,and conduction.However,state-of-the-art organic salts generally rely on ionic interaction and hydrogen bonding formation to maintain the porous channels.The synthesis of organic moiety-derived saltswith permanent accessible pores even after removal of the trapped guest molecules,and without the constraint of hydrogen bonding formation still remains a great challenge.Herein,we present an expeditious construction pathway to generate hierarchically nanoporous barium salts without hydrogen bonding formation.The strong ionic interaction of the bariumcation and sulfonate anions led to rapid reaction equilibrium(∼2 min),affording diverse barium-derived ionic polymer(Ba-IP)with permanent porosity and highly polarized channels.The produced Ba-IP materials with abundant cations and anions displayed high CO_(2)/N2 and CO_(2)/CH_(4)separation performance,with the selectivities reaching up to 89.5 and 280,respectively,at 273 K,surpassingmost of the organic polymers functionalized by ionic moieties.
基金supported by the National Natural Science Foundation of China(Grant Nos.81870328,U2004203,81800267,82170281)Henan Thousand Talents Program(Grant No.ZYQR201912131)+2 种基金Henan Medical Science and Technology Joint Building Program(Grant No.2018020002)Henan Province Youth Talent Promoting Project(Grant No.2020HYTP051)Excellent Youth Science Foundation of Henan Province(Grant No.202300410362).
文摘Acute myocardial infarction(AMI)remains a dominant origin of morbidity,mortality and disability worldwide.Increases in reactive oxygen species(ROS)are key contributor to excessive cardiac injury after AMI.Here we developed an immobilized enzyme with Superoxide Dismutase(SOD)activity cross-link with Zr-based metal-organic framework(ZrMOF)(SOD-ZrMOF)for mitigate ROS-caused injury.In vitro and in vivo evidence indicates that SOD-ZrMOF exhibits excellent biocompatibility.By efficiently scavenging ROS and suppressing oxidative stress,SOD-ZrMOF can protect the function of mitochondria,reduce cell death and alleviate inflammation.More excitingly,long-term study using an animal model of AMI demonstrated that SOD-ZrMOF can reduce the infarct area,protect cardiac function,promote angiogenesis and inhibit pathological myocardial remodeling.Therefore,SOD-ZrMOF holds great potential as an efficacious and safe nanomaterial treatment for AMI.
基金supported financially by the Division of Chemical Sciences,Geosciences,and Biosciences,Office of Basic Energy Sciences,US Department of Energy.
文摘Fluorinated porous organic networks(F-PONs)have demonstrated unique properties and applications,but approaches capable of affording F-PONs with high fluorine content and robust nanoporous architecture under metal-free and easy handling conditions are still rarely reported.Herein,using polydivinylbenzene(PDVB)as an easily available precursor,a novel and straightforward approach was developed to afford F-PONs via a dehydrative Friedel-Crafts reaction using perfluorinated benzylic alcohols as the cross-linking agent promoted by Bronsted acid(trifluoromethanesulfonic acid).The afforded material(F-PDVB)featured high fluorine content(22 at.%),large surface area(771 m^(2)·g^(-1)),and good chemical/thermal stability,rendering them as promising candidates for the adsorption of CO_(2),hydrocarbons,fluorocarbons,and chlorofluorocarbons,with weight capacities up to 520 wt.%being achieved.This simple methodology can be extended to fabricate fluorinated hyper-crosslinked polymers(F-HCPs)from rigid aromatic monomers.The progress made in this work will open new opportunities to further expand the involvement of fluorinated materials in large scale applications.
基金supported by the Division of Chemical Sciences,Geosciences,and Biosciences,Office of Basic Energy Sciences,US Department of Energy.
文摘High-entropy alloy nanoparticles(HEA-NPs)are highly underutilized in heterogeneous catalysis due to the absence of a reliable,sustainable,and facile synthetic method.Herein,we report a facile synthesis of HEA nanocatalysts realized via an ultrasounddriven wet chemistry method promoted by alcoholic ionic liquids(AILs).Owing to the intrinsic reducing ability of the hydroxyl group,AILs were synthesized and utilized as environmentally friendly alternatives to conventional reducing agents and volatile organic solvents in the synthetic process.Under high-intensity ultrasound irradiation,Au^(3+),Pd^(2+),Pt^(2+),Rh^(3+),and Ru^(3+)ions were coreduced and transformed into single-phase HEA(AuPdPtRhRu)nanocrystals without calcination.Characterization results reveal that the as-synthesized nanocrystals are composed of elements of Au,Pd,Pt,Rh,and Ru as expected.Compared to the monometallic counterparts such as Pd-NPs,the carbon-supported HEA nanocatalysts show superior catalytic performance for selective hydrogenation of phenol to cyclohexanone in terms of yield and selectivity.Our synthetic strategy provides an improved and facile methodology for the sustainable synthesis of multicomponent alloys for catalysis and other applications.
文摘1.Introduction Man-made perturbations over emissions of greenhouse gas(GHG)bring tremendous negative impacts on the survival environment[1].CO_(2)accounts for~75%of global GHG impacts with others mainly composed of N_(2)O,CH_(4),and small fluorinated gas molecules[2].Deployment of“negative emission”technologies via direct air capture(DAC)of CO_(2)by engineered chemical reactions represents one of the most promising and distinct pathways to limit and alleviate the global warming trend[3].