Recent advances in geoscience have underscored the critical role of abiogenic processes in petroleum formation,especially the formation and polymerization of methane.However,whether a direct carbon-H_(2) reaction can ...Recent advances in geoscience have underscored the critical role of abiogenic processes in petroleum formation,especially the formation and polymerization of methane.However,whether a direct carbon-H_(2) reaction can produce C_(2+)hydrocarbons(e.g.,ethane and propane)beyond methane remains an open question.Here,we demonstrate the direct synthesis of ethane and propane via reactions between amorphous carbon and H_(2) under upper mantle conditions(2-10 GPa and 800-1200℃).A systematic investigation reveals that increasing structural disorder in carbon precursors,from graphite to glassy carbon-Ⅱ and carbon black,enhances the production of C_(2)-C_(3) hydrocarbons.Through integrated X-ray diffraction and reverse Monte Carlo simulations,we establish that the continuous random atomic network structures in amorphous carbon enable one-step synthesis of heavy hydrocarbons with H_(2).These models establish a direct link between atomic-scale carbon structures and the one-step synthesis of C_(2+) hydrocarbons under H_(2)-rich,high-pressure,and high-temperature conditions—potentially revealing an efficient mechanism for the abiotic production of C_(2+) hydrocarbons in the upper mantle.展开更多
Both natural and human-induced disturbances affect the normal functioning and services of mangrove ecosystems.To address the consequences of intense human and climatic disturbances on sedimentation and carbon burial,s...Both natural and human-induced disturbances affect the normal functioning and services of mangrove ecosystems.To address the consequences of intense human and climatic disturbances on sedimentation and carbon burial,sediment cores from the last remaining mangrove Kandelia obovata forest and an adjacent mudflat in the densely populated and typhoon-prone Zhujiang(Pearl)River estuary of China,were analyzed using methods including^(210)Pb dating andδ^(13)C analysis.Results indicate that after damming in the 1950s,during 1960-1980,the natural establishment of K.obovata forests initiated the insitu sedimentation.As these forests matured during 1980-1990,they significantly boosted siltation in the region on mudflat.During 1990-2015,the invasion of Spartina alterniflora and land reclamation for aquaculture caused infiltration of coarse sediments and the impacts of typhoons were recorded within the K.obovata forest,while no clear typhoon record was observed on the mudflat.Since 2015,reforestation efforts with S.apetala that began in 1999 have reversed the effects of earlier deforestation.Over time,mangroves established a rapid autochthonous carbon burial that grew as the forests age,potentially surpassing the influx of allochthonous carbon due to deforestation.The reforestation also immediately improved carbon burial on the mudflat,which stabilized after a decade due to the rapid growth and high biomass of S.apetala.Overall,the K.obovata forest demonstrated a stronger sedimentation and carbon burial capabilities than the mudflat,with a surplus of 35.2 Mg C/hm^(2)in soil organic carbon stock and 1.0 Mg C/(hm^(2)·a)in burial rate.Organic matter dissolved in soil was mainly humus-like components,and mangrove inputs likely increased the degree of humification.This study offered direct evidence regarding the impact of multiple disturbances on local and regional sedimentation and carbon burial,and future management strategies.展开更多
The growth of leaves and biosynthesis of characteristic secondary metabolites are critically important for tea production and quality control.However,little is known about the coordinated regulation of leaf developmen...The growth of leaves and biosynthesis of characteristic secondary metabolites are critically important for tea production and quality control.However,little is known about the coordinated regulation of leaf development and catechin biosynthesis in tea plants.Here,we reported that TCP TFs are involved in both catechin biosynthesis and leaf development.An integrated analysis of catechin profiling and CsTCP expression in different tissues of plants under various environmental conditions at different developmental stages indicated significant correlations between the transcript levels of CIN-type TCPs and catechin production.CIN-type CsTCP3 and CsTCP4 and PCF-type CsTCP14 interacted with the MYB-bHLH-WD40 repeat(MBW)complex by forming a CsTCP3-CsTT8 heterodimer and modulating the transactivation activity of the promoters of anthocyanin synthase(CsANSl)and anthocyanidin reductase(CsANRl).Four types of microRNA/target modules,miR319b/CsTCP3-4,miR164b/CsCUC,miR396/CsGRF-GIF,and miR165b/HD-ZIPIII ones,were also identified and characterized for their functions in the regulation of the development of teaplant shoot tips and leaf shape.The results of these modules were reflected by their different expression patterns in developing buds and leaves that had distinctly different morphologies in three different teaplant varieties.Their roles in the regulation of catechin biosynthesis were also further verified by manipulation of microRNA319b(miR319b),which targets the transcripts of CsTCP3 and CsTCP4.Thus,CsTCPs represent at least one of these important groups of TFs that can integrate tea plant leaf development together with secondary metabolite biosynthesis.Our study provides new insight into shoot tip development and catechin production in tea plants and lays a foundation for further mechanistic understanding of the regulation of tea plant leaf development and secondary metabolism.展开更多
Tick-borne encephalitis virus(TBEV) is a pathogenic virus known to cause central nervous system(CNS) diseases in humans, and has become an increasing public health threat nowadays. The rates of TBEV infection in the e...Tick-borne encephalitis virus(TBEV) is a pathogenic virus known to cause central nervous system(CNS) diseases in humans, and has become an increasing public health threat nowadays. The rates of TBEV infection in the endemic countries are increasing. However, there is no effective antiviral against the disease. This underscores the urgent need for tools to study the emergence and pathogenesis of TBEV and to accelerate the development of vaccines and antivirals. In this study, we reported an infectious c DNA clone of TBEV that was isolated in China(the WH2012 strain). A beta-globin intron was inserted in the coding region of nonstructural protein 1(NS1) gene to improve the stability of viral genome in bacteria. In mammalian cells, the inserted intron was excised and spliced precisely, which did not lead to the generation of inserted mutants. High titers of infectious progeny viruses were generated after the transfection of the infectious clone. The cDNA-derived TBEV replicated efficiently, and caused typical cytopathic effect(CPE) and plaques in BHK-21 cells. In addition, the CPE and growth curve of cDNA-derived virus were similar to that of its parental isolate in cells. Together, we have constructed the first infectious TBEV cDNA clone in China, and the clone can be used to investigate the genetic determinants of TBEV virulence and disease pathogenesis, and to develop countermeasures against the virus.展开更多
Dissolved organic matter （DOM） plays an important role in biogeochemical cycles in aquatic ecosystem. To investigate the characteristics of DOM in Huangpu River {the last tributary of the Yangtze River）, surface wa...Dissolved organic matter （DOM） plays an important role in biogeochemical cycles in aquatic ecosystem. To investigate the characteristics of DOM in Huangpu River {the last tributary of the Yangtze River）, surface water samples were collected along the river from December 2011 to June, 2013. The concentrations of dissolved organic carbon （DOC）, the absorbance and fluorescence spectrum of DOM in water samples were measured. Fluorescent DOM in the Huangpu River was decomposed into four components by the parallel factor analysis （PARAFAC）, including one humic-like substance and three protein-like substances. It showed that high spatial variability of DOC concentration was observed in the upstream water compared to the downstream water, and so did the absorbance coefficients of chromophoric dissolved organic matter and the total fluorescence intensities of different PARAFAC components of DOM. Furthermore, there was a large difference between the polarity and bioavailability of DOM in the Huangpu River. Polar compounds dominated tyrosine-like component of fluorescent DOM in all seasons. Tryptophan-like and humic-like substances had more polar fraction in summer and autumn than those in winter, while aromatic protein-like materials had the highest polar fraction in winter. Almost all of fluorescent DOM components were refractory in spring, while less than 20% of fluorescent DOM in average were biodegradable within 4 weeks in other seasons. We concluded that the spatial variation in the abundance of DOM in the Huangpu River is mainly affected by the water discharges from the Hangjiahu Plain and the seasonal difference in polarity and bioavailability of DOM is largely determined by its origins.展开更多
The effect of lignin structural units on enzymatic hydrolysis of lignocellulosic biomass was investigated,especially the inhibitory role of lignin in non-productive adsorption with enzymes.Milled wood lignin(MWL)was i...The effect of lignin structural units on enzymatic hydrolysis of lignocellulosic biomass was investigated,especially the inhibitory role of lignin in non-productive adsorption with enzymes.Milled wood lignin(MWL)was isolated from different hardwoods of poplar,eucalyptus and acacia.The isolated lignin samples were characterized by elemental analysis,gel permeation chromatography,nitrobenzene oxidation and fourier infrared spectroscopy.The mechanism of lignin structural units on enzymatic hydrolysis of cellulose was studied by quartz crystal microbalance(QCM).The results showed that different structural units of lignin had different adsorption capacity for enzymes.The results of nitrobenzene oxidation indicated that the S/G ratio(S:syringyl-like lignin structures;G:guaiacyl-like lignin structures)of lignin of poplar was 0.99,that of eucalyptus was 1.92 and that of acacia was 1.34.According to the results of QCM,the adsorption capacity of the three lignin films was as follows:Poplar MWL(S/G ratio 0.99)<Acacia MWL(S/G ratio 1.34)<Eucalyptus MWL(S/G ratio 1.92).Eucalyptus MWL with higher degree of condensation and S/G ratio showed stronger affinity to enzymes and more non-productive adsorption with enzymes,resulting in less adsorption between enzymes and cellulose,and lower enzymatic hydrolysis efficiency.展开更多
Lignin is a natural polymer,second only to cellulose in natural reserves.Degradation is one of the ways to achieve the high-value transformation of lignin.Deep eutectic solvent(DES)thermal degradation of lignin can be...Lignin is a natural polymer,second only to cellulose in natural reserves.Degradation is one of the ways to achieve the high-value transformation of lignin.Deep eutectic solvent(DES)thermal degradation of lignin can be used as an excellent green degradation method.This paper introduces the degradation mechanism and effect of the lactic acid-choline chloride DES system in dissolving and degrading alkaline lignin,and the final solvent recovery.It can also be found from the scanning electron microscope(SEM)images that the surface of the degraded solid product is transformed from smooth to disordered.Fourier transform infrared(FTIR)spectroscopy and 1H-NMR spectroscopy were used to characterize the changes in lignin functional groups during DES treatment.The results showed that the content of phenolic hydroxyl groups increased after degradation,indicating that theβ-O-4 ether bond was broken.The molecular weight of the degraded lignin was observed by gel permeation chromatography(GPC),and the lignin residue with low molecular weight and narrow polydispersity index was obtained.The lowest average molecular weight(Mw)reached 2512 g/mol.The ratio of oxygen to carbon atoms in lignin increased substantially during degradation as measured by X-ray photoelectron spectroscopy(XPS),probably because DES treatment was accompanied by many oxidation reactions,which led to significant structural changes in lignin and a large number of ether bond breakage reactions during the reaction.The main final degradation products are aromatic monomers,vanillin,butyrovanillone,etc.展开更多
Disturbance observer-based control method has achieved good results in the carfollowing scenario of intelligent and connected vehicle(ICV).However,the gain of conventional extended disturbance observer(EDO)-based cont...Disturbance observer-based control method has achieved good results in the carfollowing scenario of intelligent and connected vehicle(ICV).However,the gain of conventional extended disturbance observer(EDO)-based control method is usually set manually rather than adjusted adaptively according to real time traffic conditions,thus declining the car-following performance.To solve this problem,a car-following strategy of ICV using EDO adjusted by reinforcement learning is proposed.Different from the conventional method,the gain of proposed strategy can be adjusted by reinforcement learning to improve its estimation accuracy.Since the“equivalent disturbance”can be compensated by EDO to a great extent,the disturbance rejection ability of the carfollowing method will be improved significantly.Both Lyapunov approach and numerical simulations are carried out to verify the effectiveness of the proposed method.展开更多
Protein-protein interactions are vital for a wide range of biological processes.The interactions between the hypoxia-inducible factor and von Hippel Lindau(VHL)are attractive drug targets for ischemic heart disease.In...Protein-protein interactions are vital for a wide range of biological processes.The interactions between the hypoxia-inducible factor and von Hippel Lindau(VHL)are attractive drug targets for ischemic heart disease.In order to disrupt this interaction,the strategy to target VHL binding site using a hydroxyproline-like(pro-like)small molecule has been reported.In this study,we focused on the inhibition mechanism between the pro-like inhibitors and the VHL protein,which were investigated via molecular dynamics simulations and binding free energy calculations.It was found that pro-like inhibitors showed a strong binding affinity toward VHL.Binding free energy calculations and free energy decompositions suggested that the modification of various regions of pro-like inhibitors may provide useful information for future drug design.展开更多
Objective:Our study aimed to assess the effects of Growth and differentiation factor 11(GDF11)on the function of endothelial progenitor cells in middle-age individuals(EPCs-MA)isolated from mouse bone marrow and to ex...Objective:Our study aimed to assess the effects of Growth and differentiation factor 11(GDF11)on the function of endothelial progenitor cells in middle-age individuals(EPCs-MA)isolated from mouse bone marrow and to explore the mechanistic relationship between GDF11 and age-related ALP impairment.Methods:Bone marrow-derived EPCs were isolated,culture and GDF11 treatment.In vivo,the mice model of myocardial ischemia(MI)was induced by permanent ligation of the left anterior descending coronary artery(LAD)and mice were randomly divided into MI group and EPCs transplantation group(EPCs-Y,EPCs-MA,EPCs-MA/GDF11).The positive effect of GDF11 treatment of EPCs-MA on MI was verified by echocardiography and the average ratio of fibrotic area to left ventricular(LV)area.In vitro,the effect of GDF11 on ameliorating EPCs aging by promoting autophagy was confirmed by transwell assay,immunofluorescence staining,characterization of EPCs ultrastructure through transmission electron microscope(TEM),lysosome imaging and Western blot.Result:Our findings demonstrate that GDF11 enhances the migration capacity of EPCs-MA and improves recovery of impaired cardiac function after myocardial infarction(MI)in mice,with EPCs isolated from young mice(EPCs-Y)as controls.Moreover,GDF11 restored functional phenotypes of EPCs-MA to levels akin to EPCs-Y,promoting the expression of CD31,endogenous NO synthase,and the restoration of von Willebrand factor(vWF)and CDH5 expression patterns,as well as the formation of Weibel-Palade bodies-key organelles for storage and secretion in endothelial cells and EPCs.Furthermore,GDF11 significantly enhanced the autophagic clearance capability of EPCs-MA by promoting ALP.Conclusions:Our results suggest that GDF11 ameliorates cardiac function impairment by restoring the activities of EPCs from aging mice through enhanced ALP.These findings suggest that GDF11 may hold therapeutic potential for improving aging-related conditions associated with declined autophagy.展开更多
In this work,an efficient and green strategy for selective extraction and high-value utilization of lignin was proposed.Most of the hemicellulose in the feedstock was first removed by alkaline pretreatment to create a...In this work,an efficient and green strategy for selective extraction and high-value utilization of lignin was proposed.Most of the hemicellulose in the feedstock was first removed by alkaline pretreatment to create a favorable structural environment for subsequent lignin dissolution.Subsequently,an acid-alcohol deep eutectic solvent(DES)system based on FeCl_(3)-ethylene glycol(FeCl 3-EG)was developed to achieve efficient and selective lignin dissolution.The results of characterization by Fourier transform infrared(FT-IR)spectroscopy,X-ray diffraction(XRD),and BrunauerEmmett-Teller(BET)showed that the lignin was removed significantly after the treatment,the cellulose structure was preserved,and the crystallinity and specific surface area were increased to 73.46% and 2.764 m^(2)/g,respectively.The highest delignification rate of 96.53% was achieved when EG:FeCl_(3)=1:0.3.Gas chromatography-mass spectrometry(GC-MS)detected a variety of low molecular phenolic products.In-situ Raman spectroscopy revealed the dynamic process of lignin dissolution from the cell wall.The regenerated lignin was systematically characterized by FTIR,thermogravimetry(TG),elemental analysis,and two-dimensional heteronuclear single quantum coherence-nuclear magnetic resonance(2D HSQC-NMR),and it was found that as the FeCl_(3) content in DES increased,the β-O-4 content decreased,and the thermal stability of lignin increased.The pyrolysis properties were further analyzed by in-situ infrared(IR)spectroscopy,pyrolysis gas chromatography-mass spectrometry(Py GC-MS),and U-tube device,which showed that the regenerated lignin pyrolysis products had a high yield of the liquid phase and good phenol selectivity(40.94%),which demonstrated good selectivity and application prospects.This study provides a theoretical basis and process reference for the green extraction of lignin and its platform compound conversion.展开更多
Silver nanoparticles(AgNPs) are widely used in many consumer products, whereas their environmental behaviors in natural aquatic systems remain unknown, especially in natural brackish media.Therefore, it is urgent to i...Silver nanoparticles(AgNPs) are widely used in many consumer products, whereas their environmental behaviors in natural aquatic systems remain unknown, especially in natural brackish media.Therefore, it is urgent to investigate the environmental fate of AgNPs in natural brackish waters.Here, we investigated the stability of citrate-coated AgNPs in natural brackish water collected from 6 different sites with distinct salinities in the Xinglinwan Reservoir, located in Xiamen City, southeast China.The obtained results showed that AgNP colloids remained stable in low-salinity waters, which was mainly determined by the effects of dissolved organic matter(DOM) promoting the stability of the nanoparticles.However, the environmental fate of AgNPs in high-salinity waters was dominated by the salinity or ionic strength, especially the free ion concentrations of Cl-, SO42-, or S2-, resulting in rapid sedimentation and dissolution.In addition, both DOM and salinity contributed to the environmental behavior of AgNPs in moderate-salinity waters,ultimately resulting in either colloidal stability or sedimentation.Overall, these results may reveal that AgNPs remain relatively stable for a long period in low-salinity natural waters,and that the stability might gradually decrease as AgNPs are transferred from freshwaters through brackish waters and eventually end up in seawater along the bay.Our findings also further indicate that the toxicity and potential risks of AgNPs may present more serious threats to the environment and organisms in natural freshwaters than in natural estuarine systems or seawater.展开更多
Zika virus(ZIKV)is emerging as a significant pathogen worldwide and may cause severe neurological disorders such as fetal microcephaly and Guillain-Barre syndrome.No drug or listed vaccines are currently available for...Zika virus(ZIKV)is emerging as a significant pathogen worldwide and may cause severe neurological disorders such as fetal microcephaly and Guillain-Barre syndrome.No drug or listed vaccines are currently available for preventing ZIKV infection.As a major target of neutralizing,ZIKV envelop(E)protein usually used for vaccine development.Nevertheless,the immunogenicity of ZIKV envelop(E)protein expressed by baculovirus display system has never been assessed.In this study,we reported a new strategy for surface display of ZIKV E protein by a recombinant baculovirus vector derived from Autographa californica multiple nuclear polyhedrosis virus(AcMNPV)and assessed its immunogenicity in mice.We produced recombinant fusion ZIKV E protein linked with signal peptide(SP)and transmembrane domain(TM)of AcMNPV GP64.The results showed that the recombinant protein was easy to produce by baculovirus display system.BALB/c mice immunized with this recombinant E protein developed ZIKV specific serum antibodies.The anti-E protein sera from the mice were able to effectively neutralize ZIKV in vitro.More importantly,AG6(IFN-a/b and IFN-c receptor deficient)mice immunized with recombinant E protein were protected against lethal ZIKV challenge.Together,thesefindings demonstrated that the recombinant E protein displayed by baculovirus can be conveniently prepared and displayed good immunogenicity in immunized mice.It is a promising practical approach for prompting the development of vaccine and related immunology research.展开更多
Ten nitrated polycyclic aromatic hydrocarbons(nPAHs)and 4 oxygenated polycyclic aromatic hydrocarbons(oPAHs)in fine particulate matter(PM2.5)samples from Mount Tai were analyzed during summer(June to August),2015.Duri...Ten nitrated polycyclic aromatic hydrocarbons(nPAHs)and 4 oxygenated polycyclic aromatic hydrocarbons(oPAHs)in fine particulate matter(PM2.5)samples from Mount Tai were analyzed during summer(June to August),2015.During the observation campaign,themean concentration of total nPAHs and oPAHs was 31.62 pg/m^(3)and 0.15 ng/m^(3),respectively.Two of the monitored compounds,namely 9-nitro-anthracene(9N-ANT)(6.86 pg/m^(3))and 9-fluorenone(9FO)(0.05 ng/m^(3))were the predominant compounds of nPAHs and oPAHs,respectively.The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization(PMF)method and the potential source contribution function(PSCF)methods.The results revealed that biomass/coal burning,gasoline vehicle emission,diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs,which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea.The incremental life cancer risk(ILCR)values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people(infant,children and adult),and the values of ILCR were 7.02×10^(−10),3.49×10^(−9)and 1.41×10^(−8)for infant,children and adults,respectively.All these values were lower than the standard of EPA(Environmental Protection Agency)(<10−6),indicating acceptable health risk of nPAHs and oPAHs.展开更多
The effects of allochthonous dissolved organic matter （DOM） on the growth and photosynthesis of Phaeodactylum tricornutum were investigated. P. tricornutum incubated in f/2 medium was exposed to DOM additives, which...The effects of allochthonous dissolved organic matter （DOM） on the growth and photosynthesis of Phaeodactylum tricornutum were investigated. P. tricornutum incubated in f/2 medium was exposed to DOM additives, which were extracted from the plant and sediment samples of a salt marsh in North Branch of the Yangtze estuary, China. During 12 days incubation, the chlorophyll fluorescence parameters of P. tricornutum were measured by a Phyto-PAM phytoplankton analyzer. Spectral properties of DOM in algae filtrates were also observed. The concentrations of chlorophyll a, active chlorophyll a, and the maximum quantum yield of photosystem II significantly decreased after four days of incubation, suggesting that the growth and photosynthetic efficiency of P. tricornutum were inhibited. After adding sediment-DOM extract, both a 250 /a 365 （the ratio of the absorption coefficients at 250 and 365 nm） and S values （spectral slope coefficients） of algae filtrates declined in the first two days, which demonstrated a loss of low molecular weight DOM. Parallel factor analysis of fluorescence spectra of DOM in algae filtrates revealed that DOM could be classified into two humic-like and two protein-like components. The fluorescence intensity of tyrosine-like component originating from algae increased significantly during incubation. This study supports the hypothesis that allochthonous DOM derived from salt marsh plant and sediment have a strong influence on the adjacent aquatic ecosystems.展开更多
The WRKY gene family is most widely known as being the key plant transcription factor family involved in various stress responses and affecting plant growth and development.In this study,a total of 86 members of the C...The WRKY gene family is most widely known as being the key plant transcription factor family involved in various stress responses and affecting plant growth and development.In this study,a total of 86 members of the CsWRKY genes were identified from the tea plant genome.Most of these genes contain several important Cis-regulatory elements in the promoter regions associated with multiple stress-responses.These genes were further classified into three groups,I,II,and III,each with 21,58,and 7 members,respectively.We showed evidence that tandem duplications,but not the whole genome duplication,are likely to drive the amplification of CsWRKY genes in tea plants.All the 86 CsWRKY genes showed differential expression patterns either in different tissues,or under exposure to diverse abiotic stresses such as drought,cold acclimation,and MeJA treatments.Additionally,the functional roles of two genes,CsWRKY29 and CsWRKY37,were examined under cold stress;and the silencing of these genes resulted in tea plant phenotypes susceptible to cold stress.Moreover,transgenic Arabidopsis lines overexpressing CsWRKY29 and CsWRKY37 genes showed higher survival rates and lower malondialdehyde levels under freezing treatment than the wild type plants.The core findings from this work provide valuable evolutionary pattern of WRKY gene family and underpinning the underlying regulatory roles of CsWRKY29 and CsWRKY37 from tea plants that conferred cold tolerance in transgenic Arabidopsis plants.展开更多
基金mainly supported by the Natural Science Foundation of China (Grant Nos. 52288102, 52090020, and 52372261)the Natural Science Foundation of Hebei Province (Grant No. E202403045)+1 种基金the S&T Program of Hebei (Grant No. 225A1102D)the Ministry of Education Chang Jiang Scholar Professor Program (Grant No. T2022241)
文摘Recent advances in geoscience have underscored the critical role of abiogenic processes in petroleum formation,especially the formation and polymerization of methane.However,whether a direct carbon-H_(2) reaction can produce C_(2+)hydrocarbons(e.g.,ethane and propane)beyond methane remains an open question.Here,we demonstrate the direct synthesis of ethane and propane via reactions between amorphous carbon and H_(2) under upper mantle conditions(2-10 GPa and 800-1200℃).A systematic investigation reveals that increasing structural disorder in carbon precursors,from graphite to glassy carbon-Ⅱ and carbon black,enhances the production of C_(2)-C_(3) hydrocarbons.Through integrated X-ray diffraction and reverse Monte Carlo simulations,we establish that the continuous random atomic network structures in amorphous carbon enable one-step synthesis of heavy hydrocarbons with H_(2).These models establish a direct link between atomic-scale carbon structures and the one-step synthesis of C_(2+) hydrocarbons under H_(2)-rich,high-pressure,and high-temperature conditions—potentially revealing an efficient mechanism for the abiotic production of C_(2+) hydrocarbons in the upper mantle.
基金Supported by the National Natural Science Foundation of China(No.U21A6001)the Guangdong Natural Science Foundation Youth Enhancement Program(No.2024A1515030206)the China Meteorological Administration Climate Change Special Program(No.QBZ202301)。
文摘Both natural and human-induced disturbances affect the normal functioning and services of mangrove ecosystems.To address the consequences of intense human and climatic disturbances on sedimentation and carbon burial,sediment cores from the last remaining mangrove Kandelia obovata forest and an adjacent mudflat in the densely populated and typhoon-prone Zhujiang(Pearl)River estuary of China,were analyzed using methods including^(210)Pb dating andδ^(13)C analysis.Results indicate that after damming in the 1950s,during 1960-1980,the natural establishment of K.obovata forests initiated the insitu sedimentation.As these forests matured during 1980-1990,they significantly boosted siltation in the region on mudflat.During 1990-2015,the invasion of Spartina alterniflora and land reclamation for aquaculture caused infiltration of coarse sediments and the impacts of typhoons were recorded within the K.obovata forest,while no clear typhoon record was observed on the mudflat.Since 2015,reforestation efforts with S.apetala that began in 1999 have reversed the effects of earlier deforestation.Over time,mangroves established a rapid autochthonous carbon burial that grew as the forests age,potentially surpassing the influx of allochthonous carbon due to deforestation.The reforestation also immediately improved carbon burial on the mudflat,which stabilized after a decade due to the rapid growth and high biomass of S.apetala.Overall,the K.obovata forest demonstrated a stronger sedimentation and carbon burial capabilities than the mudflat,with a surplus of 35.2 Mg C/hm^(2)in soil organic carbon stock and 1.0 Mg C/(hm^(2)·a)in burial rate.Organic matter dissolved in soil was mainly humus-like components,and mangrove inputs likely increased the degree of humification.This study offered direct evidence regarding the impact of multiple disturbances on local and regional sedimentation and carbon burial,and future management strategies.
基金the Nati onal Key Resea rch and Development Program of China(2018YFD1000601)the Key Research and Development(R&D)Program of Anhui Province(18030701155)funding from An hui Agr icult ural Univer sity,and funding from the State Key Lab oratory of Tea Plant Biology and Utilization.
文摘The growth of leaves and biosynthesis of characteristic secondary metabolites are critically important for tea production and quality control.However,little is known about the coordinated regulation of leaf development and catechin biosynthesis in tea plants.Here,we reported that TCP TFs are involved in both catechin biosynthesis and leaf development.An integrated analysis of catechin profiling and CsTCP expression in different tissues of plants under various environmental conditions at different developmental stages indicated significant correlations between the transcript levels of CIN-type TCPs and catechin production.CIN-type CsTCP3 and CsTCP4 and PCF-type CsTCP14 interacted with the MYB-bHLH-WD40 repeat(MBW)complex by forming a CsTCP3-CsTT8 heterodimer and modulating the transactivation activity of the promoters of anthocyanin synthase(CsANSl)and anthocyanidin reductase(CsANRl).Four types of microRNA/target modules,miR319b/CsTCP3-4,miR164b/CsCUC,miR396/CsGRF-GIF,and miR165b/HD-ZIPIII ones,were also identified and characterized for their functions in the regulation of the development of teaplant shoot tips and leaf shape.The results of these modules were reflected by their different expression patterns in developing buds and leaves that had distinctly different morphologies in three different teaplant varieties.Their roles in the regulation of catechin biosynthesis were also further verified by manipulation of microRNA319b(miR319b),which targets the transcripts of CsTCP3 and CsTCP4.Thus,CsTCPs represent at least one of these important groups of TFs that can integrate tea plant leaf development together with secondary metabolite biosynthesis.Our study provides new insight into shoot tip development and catechin production in tea plants and lays a foundation for further mechanistic understanding of the regulation of tea plant leaf development and secondary metabolism.
基金This study was supported by grants from the National Key R&D Program of China(2018YFA0507201)。
文摘Tick-borne encephalitis virus(TBEV) is a pathogenic virus known to cause central nervous system(CNS) diseases in humans, and has become an increasing public health threat nowadays. The rates of TBEV infection in the endemic countries are increasing. However, there is no effective antiviral against the disease. This underscores the urgent need for tools to study the emergence and pathogenesis of TBEV and to accelerate the development of vaccines and antivirals. In this study, we reported an infectious c DNA clone of TBEV that was isolated in China(the WH2012 strain). A beta-globin intron was inserted in the coding region of nonstructural protein 1(NS1) gene to improve the stability of viral genome in bacteria. In mammalian cells, the inserted intron was excised and spliced precisely, which did not lead to the generation of inserted mutants. High titers of infectious progeny viruses were generated after the transfection of the infectious clone. The cDNA-derived TBEV replicated efficiently, and caused typical cytopathic effect(CPE) and plaques in BHK-21 cells. In addition, the CPE and growth curve of cDNA-derived virus were similar to that of its parental isolate in cells. Together, we have constructed the first infectious TBEV cDNA clone in China, and the clone can be used to investigate the genetic determinants of TBEV virulence and disease pathogenesis, and to develop countermeasures against the virus.
基金supported by the National Natural Science Foundation of China (Nos.41071301, 40601095)the Fundamental Research Funds for the Central Universities (No.0400219216)
文摘Dissolved organic matter （DOM） plays an important role in biogeochemical cycles in aquatic ecosystem. To investigate the characteristics of DOM in Huangpu River {the last tributary of the Yangtze River）, surface water samples were collected along the river from December 2011 to June, 2013. The concentrations of dissolved organic carbon （DOC）, the absorbance and fluorescence spectrum of DOM in water samples were measured. Fluorescent DOM in the Huangpu River was decomposed into four components by the parallel factor analysis （PARAFAC）, including one humic-like substance and three protein-like substances. It showed that high spatial variability of DOC concentration was observed in the upstream water compared to the downstream water, and so did the absorbance coefficients of chromophoric dissolved organic matter and the total fluorescence intensities of different PARAFAC components of DOM. Furthermore, there was a large difference between the polarity and bioavailability of DOM in the Huangpu River. Polar compounds dominated tyrosine-like component of fluorescent DOM in all seasons. Tryptophan-like and humic-like substances had more polar fraction in summer and autumn than those in winter, while aromatic protein-like materials had the highest polar fraction in winter. Almost all of fluorescent DOM components were refractory in spring, while less than 20% of fluorescent DOM in average were biodegradable within 4 weeks in other seasons. We concluded that the spatial variation in the abundance of DOM in the Huangpu River is mainly affected by the water discharges from the Hangjiahu Plain and the seasonal difference in polarity and bioavailability of DOM is largely determined by its origins.
基金National Natural Science Foundation of China(31730106,21704045).
文摘The effect of lignin structural units on enzymatic hydrolysis of lignocellulosic biomass was investigated,especially the inhibitory role of lignin in non-productive adsorption with enzymes.Milled wood lignin(MWL)was isolated from different hardwoods of poplar,eucalyptus and acacia.The isolated lignin samples were characterized by elemental analysis,gel permeation chromatography,nitrobenzene oxidation and fourier infrared spectroscopy.The mechanism of lignin structural units on enzymatic hydrolysis of cellulose was studied by quartz crystal microbalance(QCM).The results showed that different structural units of lignin had different adsorption capacity for enzymes.The results of nitrobenzene oxidation indicated that the S/G ratio(S:syringyl-like lignin structures;G:guaiacyl-like lignin structures)of lignin of poplar was 0.99,that of eucalyptus was 1.92 and that of acacia was 1.34.According to the results of QCM,the adsorption capacity of the three lignin films was as follows:Poplar MWL(S/G ratio 0.99)<Acacia MWL(S/G ratio 1.34)<Eucalyptus MWL(S/G ratio 1.92).Eucalyptus MWL with higher degree of condensation and S/G ratio showed stronger affinity to enzymes and more non-productive adsorption with enzymes,resulting in less adsorption between enzymes and cellulose,and lower enzymatic hydrolysis efficiency.
基金This work was financially supported by the National Natural Science Foundation of China(31730106).
文摘Lignin is a natural polymer,second only to cellulose in natural reserves.Degradation is one of the ways to achieve the high-value transformation of lignin.Deep eutectic solvent(DES)thermal degradation of lignin can be used as an excellent green degradation method.This paper introduces the degradation mechanism and effect of the lactic acid-choline chloride DES system in dissolving and degrading alkaline lignin,and the final solvent recovery.It can also be found from the scanning electron microscope(SEM)images that the surface of the degraded solid product is transformed from smooth to disordered.Fourier transform infrared(FTIR)spectroscopy and 1H-NMR spectroscopy were used to characterize the changes in lignin functional groups during DES treatment.The results showed that the content of phenolic hydroxyl groups increased after degradation,indicating that theβ-O-4 ether bond was broken.The molecular weight of the degraded lignin was observed by gel permeation chromatography(GPC),and the lignin residue with low molecular weight and narrow polydispersity index was obtained.The lowest average molecular weight(Mw)reached 2512 g/mol.The ratio of oxygen to carbon atoms in lignin increased substantially during degradation as measured by X-ray photoelectron spectroscopy(XPS),probably because DES treatment was accompanied by many oxidation reactions,which led to significant structural changes in lignin and a large number of ether bond breakage reactions during the reaction.The main final degradation products are aromatic monomers,vanillin,butyrovanillone,etc.
基金State Key Laboratory of Automotive Safety and Energy,Grant/Award Number:KFY2208National Natural Science Foundation of China,Grant/Award Numbers:U2013601,U20A20225+1 种基金Key Research and Development Plan of Anhui Province,Grant/Award Number:202004a05020058the Natural Science Foundation of Hefei,China(Grant No.2021032)。
文摘Disturbance observer-based control method has achieved good results in the carfollowing scenario of intelligent and connected vehicle(ICV).However,the gain of conventional extended disturbance observer(EDO)-based control method is usually set manually rather than adjusted adaptively according to real time traffic conditions,thus declining the car-following performance.To solve this problem,a car-following strategy of ICV using EDO adjusted by reinforcement learning is proposed.Different from the conventional method,the gain of proposed strategy can be adjusted by reinforcement learning to improve its estimation accuracy.Since the“equivalent disturbance”can be compensated by EDO to a great extent,the disturbance rejection ability of the carfollowing method will be improved significantly.Both Lyapunov approach and numerical simulations are carried out to verify the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(No.21973064)the Post-Doctor Research Project,West China Hospital,Sichuan University(No.2021HXBH017)。
文摘Protein-protein interactions are vital for a wide range of biological processes.The interactions between the hypoxia-inducible factor and von Hippel Lindau(VHL)are attractive drug targets for ischemic heart disease.In order to disrupt this interaction,the strategy to target VHL binding site using a hydroxyproline-like(pro-like)small molecule has been reported.In this study,we focused on the inhibition mechanism between the pro-like inhibitors and the VHL protein,which were investigated via molecular dynamics simulations and binding free energy calculations.It was found that pro-like inhibitors showed a strong binding affinity toward VHL.Binding free energy calculations and free energy decompositions suggested that the modification of various regions of pro-like inhibitors may provide useful information for future drug design.
基金the National Natural Science Foundation of China(81421063)China Postdoctoral Science Foundation(2016M591556)+2 种基金Natural Science Foundation of Heilongjiang Province of China(H2016008)Postdoctoral Science Foundation of Heilongjiang Province of China(LBH-Z15146)Research Project of the Health and Family Planning Commission of Heilongjiang Province(2016-166).
文摘Objective:Our study aimed to assess the effects of Growth and differentiation factor 11(GDF11)on the function of endothelial progenitor cells in middle-age individuals(EPCs-MA)isolated from mouse bone marrow and to explore the mechanistic relationship between GDF11 and age-related ALP impairment.Methods:Bone marrow-derived EPCs were isolated,culture and GDF11 treatment.In vivo,the mice model of myocardial ischemia(MI)was induced by permanent ligation of the left anterior descending coronary artery(LAD)and mice were randomly divided into MI group and EPCs transplantation group(EPCs-Y,EPCs-MA,EPCs-MA/GDF11).The positive effect of GDF11 treatment of EPCs-MA on MI was verified by echocardiography and the average ratio of fibrotic area to left ventricular(LV)area.In vitro,the effect of GDF11 on ameliorating EPCs aging by promoting autophagy was confirmed by transwell assay,immunofluorescence staining,characterization of EPCs ultrastructure through transmission electron microscope(TEM),lysosome imaging and Western blot.Result:Our findings demonstrate that GDF11 enhances the migration capacity of EPCs-MA and improves recovery of impaired cardiac function after myocardial infarction(MI)in mice,with EPCs isolated from young mice(EPCs-Y)as controls.Moreover,GDF11 restored functional phenotypes of EPCs-MA to levels akin to EPCs-Y,promoting the expression of CD31,endogenous NO synthase,and the restoration of von Willebrand factor(vWF)and CDH5 expression patterns,as well as the formation of Weibel-Palade bodies-key organelles for storage and secretion in endothelial cells and EPCs.Furthermore,GDF11 significantly enhanced the autophagic clearance capability of EPCs-MA by promoting ALP.Conclusions:Our results suggest that GDF11 ameliorates cardiac function impairment by restoring the activities of EPCs from aging mice through enhanced ALP.These findings suggest that GDF11 may hold therapeutic potential for improving aging-related conditions associated with declined autophagy.
基金the National Natural Science Foundation of China(No.32271807)the Guangdong Basic and Applied Basic Research Foundation(2024A1515011941).
文摘In this work,an efficient and green strategy for selective extraction and high-value utilization of lignin was proposed.Most of the hemicellulose in the feedstock was first removed by alkaline pretreatment to create a favorable structural environment for subsequent lignin dissolution.Subsequently,an acid-alcohol deep eutectic solvent(DES)system based on FeCl_(3)-ethylene glycol(FeCl 3-EG)was developed to achieve efficient and selective lignin dissolution.The results of characterization by Fourier transform infrared(FT-IR)spectroscopy,X-ray diffraction(XRD),and BrunauerEmmett-Teller(BET)showed that the lignin was removed significantly after the treatment,the cellulose structure was preserved,and the crystallinity and specific surface area were increased to 73.46% and 2.764 m^(2)/g,respectively.The highest delignification rate of 96.53% was achieved when EG:FeCl_(3)=1:0.3.Gas chromatography-mass spectrometry(GC-MS)detected a variety of low molecular phenolic products.In-situ Raman spectroscopy revealed the dynamic process of lignin dissolution from the cell wall.The regenerated lignin was systematically characterized by FTIR,thermogravimetry(TG),elemental analysis,and two-dimensional heteronuclear single quantum coherence-nuclear magnetic resonance(2D HSQC-NMR),and it was found that as the FeCl_(3) content in DES increased,the β-O-4 content decreased,and the thermal stability of lignin increased.The pyrolysis properties were further analyzed by in-situ infrared(IR)spectroscopy,pyrolysis gas chromatography-mass spectrometry(Py GC-MS),and U-tube device,which showed that the regenerated lignin pyrolysis products had a high yield of the liquid phase and good phenol selectivity(40.94%),which demonstrated good selectivity and application prospects.This study provides a theoretical basis and process reference for the green extraction of lignin and its platform compound conversion.
基金supported by the Key Program of International Cooperation of Fujian Province (No.2019I0032)the sponsor-id="https://doi.org/10.13039/501100001809" xlink:role="http://www.elsevier.com/xml/linking-roles/grant-sponsor" xlink:type="simple">National Natural Science Foundation of China (Nos.21507129 and 61705228)the sponsorid="https://doi.org/10.13039/501100003392" xlink:role="http:// www.elsevier.com/xml/linking-roles/grant-sponsor" xlink: type="simple">Natural Science Foundation of Fujian Province, China (No.2018J05028).
文摘Silver nanoparticles(AgNPs) are widely used in many consumer products, whereas their environmental behaviors in natural aquatic systems remain unknown, especially in natural brackish media.Therefore, it is urgent to investigate the environmental fate of AgNPs in natural brackish waters.Here, we investigated the stability of citrate-coated AgNPs in natural brackish water collected from 6 different sites with distinct salinities in the Xinglinwan Reservoir, located in Xiamen City, southeast China.The obtained results showed that AgNP colloids remained stable in low-salinity waters, which was mainly determined by the effects of dissolved organic matter(DOM) promoting the stability of the nanoparticles.However, the environmental fate of AgNPs in high-salinity waters was dominated by the salinity or ionic strength, especially the free ion concentrations of Cl-, SO42-, or S2-, resulting in rapid sedimentation and dissolution.In addition, both DOM and salinity contributed to the environmental behavior of AgNPs in moderate-salinity waters,ultimately resulting in either colloidal stability or sedimentation.Overall, these results may reveal that AgNPs remain relatively stable for a long period in low-salinity natural waters,and that the stability might gradually decrease as AgNPs are transferred from freshwaters through brackish waters and eventually end up in seawater along the bay.Our findings also further indicate that the toxicity and potential risks of AgNPs may present more serious threats to the environment and organisms in natural freshwaters than in natural estuarine systems or seawater.
基金supported by grants from the National Key R&D Program of China(2016YFD0500406)the National Natural Science Foundation of China(NSFC)(no.81672036)the Youth Innovation Promotion Association of CAS(2016302)
文摘Zika virus(ZIKV)is emerging as a significant pathogen worldwide and may cause severe neurological disorders such as fetal microcephaly and Guillain-Barre syndrome.No drug or listed vaccines are currently available for preventing ZIKV infection.As a major target of neutralizing,ZIKV envelop(E)protein usually used for vaccine development.Nevertheless,the immunogenicity of ZIKV envelop(E)protein expressed by baculovirus display system has never been assessed.In this study,we reported a new strategy for surface display of ZIKV E protein by a recombinant baculovirus vector derived from Autographa californica multiple nuclear polyhedrosis virus(AcMNPV)and assessed its immunogenicity in mice.We produced recombinant fusion ZIKV E protein linked with signal peptide(SP)and transmembrane domain(TM)of AcMNPV GP64.The results showed that the recombinant protein was easy to produce by baculovirus display system.BALB/c mice immunized with this recombinant E protein developed ZIKV specific serum antibodies.The anti-E protein sera from the mice were able to effectively neutralize ZIKV in vitro.More importantly,AG6(IFN-a/b and IFN-c receptor deficient)mice immunized with recombinant E protein were protected against lethal ZIKV challenge.Together,thesefindings demonstrated that the recombinant E protein displayed by baculovirus can be conveniently prepared and displayed good immunogenicity in immunized mice.It is a promising practical approach for prompting the development of vaccine and related immunology research.
基金supported by the China Postdoctoral Science Foundation(No.2020M670667)the Tianjin Municipal Education Commission Research Project(No.2017KJ244)+1 种基金the Key Research and Development Plan of Tianjin(No.18YFZCSF01400)the National Natural Science Foundation of China(Nos.41701579,21806158).
文摘Ten nitrated polycyclic aromatic hydrocarbons(nPAHs)and 4 oxygenated polycyclic aromatic hydrocarbons(oPAHs)in fine particulate matter(PM2.5)samples from Mount Tai were analyzed during summer(June to August),2015.During the observation campaign,themean concentration of total nPAHs and oPAHs was 31.62 pg/m^(3)and 0.15 ng/m^(3),respectively.Two of the monitored compounds,namely 9-nitro-anthracene(9N-ANT)(6.86 pg/m^(3))and 9-fluorenone(9FO)(0.05 ng/m^(3))were the predominant compounds of nPAHs and oPAHs,respectively.The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization(PMF)method and the potential source contribution function(PSCF)methods.The results revealed that biomass/coal burning,gasoline vehicle emission,diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs,which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea.The incremental life cancer risk(ILCR)values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people(infant,children and adult),and the values of ILCR were 7.02×10^(−10),3.49×10^(−9)and 1.41×10^(−8)for infant,children and adults,respectively.All these values were lower than the standard of EPA(Environmental Protection Agency)(<10−6),indicating acceptable health risk of nPAHs and oPAHs.
基金supported by the National Natural Science Foundation of China (No. 40601095)the Sino-Russia International Cooperation Program (No.2007DFR90050)the State Key Laboratory of Pollution Control and Resources Reuse (No. PCRRY003)
文摘The effects of allochthonous dissolved organic matter （DOM） on the growth and photosynthesis of Phaeodactylum tricornutum were investigated. P. tricornutum incubated in f/2 medium was exposed to DOM additives, which were extracted from the plant and sediment samples of a salt marsh in North Branch of the Yangtze estuary, China. During 12 days incubation, the chlorophyll fluorescence parameters of P. tricornutum were measured by a Phyto-PAM phytoplankton analyzer. Spectral properties of DOM in algae filtrates were also observed. The concentrations of chlorophyll a, active chlorophyll a, and the maximum quantum yield of photosystem II significantly decreased after four days of incubation, suggesting that the growth and photosynthetic efficiency of P. tricornutum were inhibited. After adding sediment-DOM extract, both a 250 /a 365 （the ratio of the absorption coefficients at 250 and 365 nm） and S values （spectral slope coefficients） of algae filtrates declined in the first two days, which demonstrated a loss of low molecular weight DOM. Parallel factor analysis of fluorescence spectra of DOM in algae filtrates revealed that DOM could be classified into two humic-like and two protein-like components. The fluorescence intensity of tyrosine-like component originating from algae increased significantly during incubation. This study supports the hypothesis that allochthonous DOM derived from salt marsh plant and sediment have a strong influence on the adjacent aquatic ecosystems.
基金the National Natural Science Foundation of China(32172626)the Anhui Provincial Natural Science Foundation(2208085MC72,1908085MC75)the Anhui University Collaborative Innovation Project(GXXT-2020-080).
文摘The WRKY gene family is most widely known as being the key plant transcription factor family involved in various stress responses and affecting plant growth and development.In this study,a total of 86 members of the CsWRKY genes were identified from the tea plant genome.Most of these genes contain several important Cis-regulatory elements in the promoter regions associated with multiple stress-responses.These genes were further classified into three groups,I,II,and III,each with 21,58,and 7 members,respectively.We showed evidence that tandem duplications,but not the whole genome duplication,are likely to drive the amplification of CsWRKY genes in tea plants.All the 86 CsWRKY genes showed differential expression patterns either in different tissues,or under exposure to diverse abiotic stresses such as drought,cold acclimation,and MeJA treatments.Additionally,the functional roles of two genes,CsWRKY29 and CsWRKY37,were examined under cold stress;and the silencing of these genes resulted in tea plant phenotypes susceptible to cold stress.Moreover,transgenic Arabidopsis lines overexpressing CsWRKY29 and CsWRKY37 genes showed higher survival rates and lower malondialdehyde levels under freezing treatment than the wild type plants.The core findings from this work provide valuable evolutionary pattern of WRKY gene family and underpinning the underlying regulatory roles of CsWRKY29 and CsWRKY37 from tea plants that conferred cold tolerance in transgenic Arabidopsis plants.
