Transgenic trees as a new source for biofuel have brought a great interest in tree biotechnology. Genetically modifying forest trees for ethanol production have advantages in technical challenges, costs, environmental...Transgenic trees as a new source for biofuel have brought a great interest in tree biotechnology. Genetically modifying forest trees for ethanol production have advantages in technical challenges, costs, environmental concerns, and financial problems over some of crops. Genetic engineering of forest trees can be used to reduce the level of lignin, to produce the fast-growing trees, to develop trees with higher cellulose, and to allow the trees to be grown more widely. Trees can establish themselves in the field with less care of farmers, compared to most of crops. Transgenic crops as a new source for biofuel have been recently reviewed in several reviews. Here, we overview transgenic woody plants as a new source for biofuel including genetically modified woody plants and environment; main focus of woody plants genetic modifications; solar to chemical energy transfer; cellulose biosynthesis; lignin biosynthesis; and cellulosic ethanol as biofuel.展开更多
Malonyl-CoA synthetases may modulate cell responses to abiotic stress by regulating stress-related signaling transduction pathways or activating expression of transcription factors.However,the molecular mechanism of c...Malonyl-CoA synthetases may modulate cell responses to abiotic stress by regulating stress-related signaling transduction pathways or activating expression of transcription factors.However,the molecular mechanism of cold stress tolerance enhanced by malonyl-CoA synthetase is not fully understood.Here,we report that overexpression of the Arabidopsis thaliana malonyl-CoA synthetase gene AAE13.1 resulted in increased cell viability and growth rate and decreased thiobarbituric acid reactive substances under cold stress in rice(Oryza sativa L.),tobacco(Nicotiana tabacum),and slash pine(Pinus elliottii Engelm.).AAE13.1 was associated with cold stress tolerance by increasing the activity of ascorbate peroxidase,catalase,polyphenol oxidase,and peroxidase and the accumulation of acid phosphatase and alkaline phosphatase.Among six rice mitogenactivated protein kinase(MAPK)genes examined,AAE13.1 overexpression increased the expression of OsMAPK genes during cold stress.AAE13.1 activated expression of stressresponse genes OsMAPK1,OsMAPK2,and OsMAPK3,indicating that AAE13.1 enhances cold stress tolerance by regulating expression of MAPK genes in plant cells.These results increase our understanding of cold stress tolerance in species of monocotyledons,dicotyledons,and gymnosperms.展开更多
Although roots are so important for plant growth and crop productivity, the molecular mecha- nism（s） of root formation and growth is not fully under- stood. To increase our understanding of the underlying molecular ...Although roots are so important for plant growth and crop productivity, the molecular mecha- nism（s） of root formation and growth is not fully under- stood. To increase our understanding of the underlying molecular mechanisms, here we review microRNA regu- lation of processes related to root formation： the regulation of transcription factors, nutrient uptake, stress signaling, and growth signaling. We have summarized the interaction, expression, transport, and signaling events that involve microRNAs in ideal and stressed conditions in a number of model plants, highlighting the involvement of microRNAs in root formation. MicroRNAs are now known to be important players in root initiation, development, and growth; understanding the precise mechanisms involved will be valuable for plant molecular breeding to develop high-yielding crops with high stress resistance and low nutrient requirements.展开更多
Due to the shortage supply of propylene and the development of shale gas,there is increased interest in on-purpose propane dehydrogenation(PDH)technology for propylene production.Ga-based catalysts have great potentia...Due to the shortage supply of propylene and the development of shale gas,there is increased interest in on-purpose propane dehydrogenation(PDH)technology for propylene production.Ga-based catalysts have great potential in PDH,due to the high activity,low carbon deposit and deactivation.Ga-hydrides formed during PDH reduce the rate,selectivity and yield of propylene.In this contribution,CO_(2)is introduced into PDH as a soft oxidant to eliminate the unfavorable intermediate species Ga^(δ+)-Hx re-generating Ga^(3+)-O pairs,and also minimize coke deposition thereby improving the catalytic performance.In situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy experiments show that CO_(2)can effectively eliminate Ga^(δ+)-Hx.At different temperatures,co-feeding CO_(2)during PDH over Ga_(2)O_(3)/SiO_(2)catalysts with different loadings significantly improves the stability of the conversion and selectivity,especially the latter,and provide a new dimension for improving the performance of PDH process.展开更多
The development of efficient catalytic electrode toward oxygen reduction reaction(ORR)is still a great challenge for the wide use of zinc–air batteries.Herein,Co_(2)N nanoparticles(NPs)anchored on N-doped carbon from...The development of efficient catalytic electrode toward oxygen reduction reaction(ORR)is still a great challenge for the wide use of zinc–air batteries.Herein,Co_(2)N nanoparticles(NPs)anchored on N-doped carbon from cattail were verified with excellent catalytic performances for ORR.The onset and half-wave potentials over the optimal catalyst reach to 0.96 V and 0.84 V,respectively.Current retention rates of 96.8%after 22-h test and 98.8%after running 1600 s were obtained in 1 M methanol solution.Density functional theory simulation proposes an apparently increased electronic states of Co_(2)N in N-doped carbon layer close to the Fermi level.Higher charge density,favorable adsorption,and charge transfer of intermediates originate from the coexistence of Co_(2)N NPs and N atoms in carbon skeleton.The superior catalytic activity of composites also was confirmed in zinc–air batteries.This novel catalytic property and controllable preparation approach of Co_(2)Ncarbon composites provide a promising avenue to fabricate metal-containing catalytically active carbon from biomass.展开更多
RNA-seq and single-cell genomic research emerge as an important research area in the recent years due to its ability to examine genetic information of any number of single cells in all living organisms.The knowledge g...RNA-seq and single-cell genomic research emerge as an important research area in the recent years due to its ability to examine genetic information of any number of single cells in all living organisms.The knowledge gained from RNA-seq and single-cell genomic research will have a great impact in many aspects of plant biology.In this review,we summary and discuss the biological significance of RNA-seq and single-cell genomic research in plants including the single-cell DNA-sequencing,RNA-seq and single-cell RNA sequencing in woody plants,methods of RNA-seq and single-cell RNA-sequencing,single-cell RNA-sequencing for studying plant development,and single-cell RNA-sequencing for elucidating cell type composition.We will focus on RNA-seq and single-cell RNA sequencing in woody plants,understanding of plant development through single-cell RNAsequencing,and elucidation of cell type composition via single-cell RNA-sequencing.Information presented in this review will be helpful to increase our understanding of plant genomic research in a way with the power of plant single-cell RNA-sequencing analysis.展开更多
Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully unders...Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully understood.Here,Agrobacterium tumefaciens carrying the gene for Arabidopsis thaliana cysteine2/histidine2-type transcription factor 6(ZAT6)was used to engineer rice(Oryza sativa L.),cotton(Gossypium hirsutum L.),and slash pine(Pinus elliottii Engelm.)to generate transgenic cell lines.Transgenic cells were then inoculated with the pathogenic bacterium Pseudomonas syringae.Compared to the control,cell viability of transgenic cells increased 39–47%and growth rate increased 9–15%by 7 days after inoculation in rice,cotton and slash pine.Acid phosphatase activity and alkaline phosphatase activity and transcript levels of Ca 2+-dependent protein kinase genes OsCPK1,OsCPK2,OsCPK6,and OsCPK8 and mitogen-activated protein kinase genes OsMAPK1,OsMAPK2,OsMAPK3,and OsMAPK8 increased signifi cantly in transgenic rice cells by 3 day after inoculation,and extracellular pH had decreased by 10–14%by 96 min after inoculation in transgenic rice,cotton and slash pine cells.These results suggest that ZAT6 enhances P.syringae resistance in plant cells by modulating transcription of CPK and MAPK and oxidase activity.展开更多
Well-established targeted technologies to engi- neer genomes such as zinc-finger nuclease-based editing （ZFN）, transcription activator-like effector nuclease-based editing （TALEN）, and clustered regularly interspa...Well-established targeted technologies to engi- neer genomes such as zinc-finger nuclease-based editing （ZFN）, transcription activator-like effector nuclease-based editing （TALEN）, and clustered regularly interspaced short palindromic repeats and associated protein system-based editing （CRISPR/Cas） are proving to advance basic and applied research in numerous plant species. Compared with systems using ZFNs and TALENs, the most recently developed CRISPR/Cas system is more efficient due to its use of an RNA-guided nuclease to generate double-strand DNA breaks. To accelerate the applications of these technologies, we provide here a detailed overview of these systems, highlight the strengths and weaknesses of each, summarize research advances made with these technologies in model and crop plants, and discuss their applications in plant functional genomics. Such targeted approaches for genetically modifying plants will benefit agricultural production in the future.展开更多
Ischemia-related diseases,particularly coronary artery disease(CAD),account for the majority of deaths worldwide.Myocardial ischemia is a serious condition and the delay in reperfusion of ischemic tissues can be life-...Ischemia-related diseases,particularly coronary artery disease(CAD),account for the majority of deaths worldwide.Myocardial ischemia is a serious condition and the delay in reperfusion of ischemic tissues can be life-threatening.This is particular true in the aged population.Rapid and accurate early detection of myocardial ischemia is highly desirable so that various therapeutic regiments can be given before irreversible myocardial damage occurs.Myocardial perfusion imaging with radiotracers is an integral component in evaluations of patients with known or suspected CAD. 99m Tc-Sestamibi and 99m Tc-Tetrofosmin are commercial radiopharmaceuticals currently available for myocardial perfusion imaging.Despite their widespread clinical applications,both 99m Tc-Sestamibi and 99m Tc-Tetrofosmin do not meet the requirements of an ideal perfusion imaging agent,largely due to their high liver uptake.The intense liver uptake makes it difficultto interpret the heart activity in the inferior and left ventricular wall.Photon scattering from the high liver radioactivity accumulation remains a significant challenge for diagnosis of heart diseases.This review will summarize the most recent research efforts to minimize the liver uptake of cationic 99m Tc radiotracers by using ether and crown ether-containing chelators. Fast liver clearance will shorten the duration of imaging protocols(<30 min post-injection) ,and allow for early acquisition of heart images with high quality. Improvement of heart/liver ratio may permit better detection of the presence and extent of coronary artery disease.Identification of such a new radiotracer that allows for the improved noninvasive assessment of myocardial perfusion would be of considerable benefit in treatment of patients with suspected CAD.展开更多
Genome editing is a valuable tool to target specific DNA sequences for mutagenesis in the genomes of microbes, plants, and animals. Although different genome editing technologies are available, the clustered regularly...Genome editing is a valuable tool to target specific DNA sequences for mutagenesis in the genomes of microbes, plants, and animals. Although different genome editing technologies are available, the clustered regularly interspaced short palindromic repeats/Cas9 （CRISPR/ Cas9） system, which utilizes engineered endonucleases to generate a double-stranded DNA break （DSB） in the target DNA region and subsequently stimulates site-specific mutagenesis through DNA repair machineries, is emerging as a powerful genome editing tool for elucidating mecha- nisms of protection from plant viruses, plant disease resistance, and gene functions in basic and applied research. In this review, we provide an overview of recent advances in the CRISPR system associated genome editing in plants by focusing on application of this technology in model plants, crop plants, fruit plants, woody plants and grasses and discuss how genome editing associated with the CRISPR system can provide insights into genome modifications and functional genomics in plants.展开更多
Volatile organic chloramines are reported as the disinfection byproducts during chlorination or chloramination.However,ClO2,as an important alternative disinfectant for chlorine,was not considered to produce halogenat...Volatile organic chloramines are reported as the disinfection byproducts during chlorination or chloramination.However,ClO2,as an important alternative disinfectant for chlorine,was not considered to produce halogenated amines.In the present work,volatile organic chloramines including(CH3)2 NCl and CH3 NCl2 were found to be generated during the reaction of ClO2 and the dye pollutants.(CH3)2 NCl was the dominant volatile DBP to result from ClO2 treated all four dye pollutants including Methyl Orange,Methyl Red,Methylene Blue and Malachite Green,with molar yields ranging from 2.6%to 38.5%at a ClO2 to precursor(ClO2/P)molar ratio of 10.HOCl was identified and proved to be the reactive species for the formation of(CH3)2 NCl,which implied(CH3)2 NCl was transformed by a combined oxidation of ClO2 and hypochlorous acid.(CH3)2 NCl concentrations in the ppb range were observed when real water samples were treated by ClO2 in the presence of the dye pollutants.The results suggest that these azo dyes are one of the significant precursors for the formation of HOCl during ClO2 treatment and that organic chloramines should be considered in ClO2 disinfection chemistry and water treatment.展开更多
In this work,poly(vinylidene fluoride)(PVDF)membranes with hydrophilicity as well as preeminent mechanical strength and dye removal efficiency were fabricated by blending with three dimensional hydroxyapatite nanopart...In this work,poly(vinylidene fluoride)(PVDF)membranes with hydrophilicity as well as preeminent mechanical strength and dye removal efficiency were fabricated by blending with three dimensional hydroxyapatite nanoparticles(HAPNPs).Surface chemical composition and morphology of the prepared membranes were systematically investigated by ATR-FTIR,XPS,XRD,FESEM,and EDS mapping analyses.The results verified that a large number of HAPNPs were successfully embedded on the modified membrane crosssections.Moreover,HAPNPs content in the casting solution is an important factor that could have profound influence on the structures and performances of PVDF/HAPNPs blend membranes.The optimal membrane M2 with 2 wt%HAPNPs exhibited excellent hydrophilicity,outstanding mechanical strength of 19.60 MPa,and high water flux of(2466±31)L·m^2·h^-1.The maximum static adsorption capacity of the optimal membrane was about 10.83 mg/g,which is 3.75 times that of the pristine PVDF membrane(2.89 mg/g).PVDF/HAPNPs membranes were not only utilized for static adsorption,but also applied to dynamic dye removal.The possible adsorption mechanism between Congo red(CR)and HAPNPs embedded on the blend membranes was firstly discussed in this work.HAPNPs interacted with CR via Lewis reaction,hydrogen bond interaction,as well as electrostatic attraction to achieve the adsorption effect.Herein,the PVDF/HAPNPs blend membranes with extraordinary hydrophilicity,mechanical strength,and dye removal efficiency possess tremendous potential for practical applications of wastewater treatment.展开更多
The protection of classical or significant reference stratigraphic sections of the nation’s valuable geoheritage has become a priority by the Chinese government and national stratigraphic commission.The process for t...The protection of classical or significant reference stratigraphic sections of the nation’s valuable geoheritage has become a priority by the Chinese government and national stratigraphic commission.The process for the protection and documentation of stratigraphic sections includes:(1)marked tablets showing the standardized bed,member and formation divisions and,where applicable,standardized meter intervals for future investigations;(2)a monument or other on-site interpretive information;and(3)field guides for different audiences summarizing its importance with maps and detailed descriptions.In particular,the ten Global Stratotype Sections and Points(GSSPs)established in southern China are well preserved and managed;and some are now within tourist-friendly educational national geoparks.We suggest that other national stratigraphic commissions might incorporate some of the experiences from China’s current efforts to preserve and standardize important reference sections for Earth history research.展开更多
Purpose This study compared the acute effects of a session of isometric strength training(ISO)with heavy resistance training(HRT)training on 20-m sprint,countermovement jump(CMJ)and isometric mid-thigh pull(IMTP)perfo...Purpose This study compared the acute effects of a session of isometric strength training(ISO)with heavy resistance training(HRT)training on 20-m sprint,countermovement jump(CMJ)and isometric mid-thigh pull(IMTP)performance.Methods Ten resistance-trained athletes(age:26.7±6.2 years,body mass:71.5±16.2 kg,height:1.68±0.10 m)performed baseline measures for 20-m sprint,CMJ and IMTP prior to either an ISO or HRT session.During both training sessions,participants performed back squats,Romanian deadlift and split squat.Post-test performances were measured 5 min and 24 h after each training session.Participants returned a week later to perform the other training session.Results A significant time×condition effect was found for 20-m sprint time(P=0.007)and IMTP peak force(P=0.003).Main time effect was observed for 20-m sprint(P<0.001),CMJ height(P<0.001)and IMTP peak force(P<0.001).HRT resulted in a greater increase in sprint time at 5 min(0.17±0.12 vs.0.06±0.05 s,P=0.013,g=1.15)and 24 h(0.01±0.09 vs.0.00±0.05 s,P=0.004,g=1.32)post-training as compared to ISO.Similarly,HRT resulted in a significantly larger reduction in IMTP peak force than ISO at both 5 min(-363.3±248.8 vs.-98.9±230.3 N,P=0.024,g=1.06)and 24 h(-289.2±256.2 vs.37.9±177.8 N,P=0.004,g=1.42)post-training.Total impulses generated during each exercise were greater during ISO than HRT(P<0.001–0.006).Rating of perceived recovery post 24 h was higher in ISO than HRT(P=0.002).Conclusion The above results indicated that acute HRT led to a greater reduction in sprinting strength performance and lower perceived recovery post-24 h than ISO.展开更多
Hydrogenative coupling of CO_(2)to ethanol presents a sustainable pathway for carbon neutralization,yet the fundamental active sites and reaction pathway/mechanism remain unclear.Here,we investigate CO_(2)hydrogenativ...Hydrogenative coupling of CO_(2)to ethanol presents a sustainable pathway for carbon neutralization,yet the fundamental active sites and reaction pathway/mechanism remain unclear.Here,we investigate CO_(2)hydrogenative coupling over Cu/CeO_(2-x)catalysts,achieving an optimal CO_(2)conversion of~5%and ethanol selectivity of~95%under 30 atm,H_(2)/CO_(2)=3,at 240℃,and gas hourly space velocity(GHSV)=120 mL·gcat^(-1)·h^(-1).We revealed that both Cu(I)and oxygen vacancies(Ov)serve as active sites,with turnover frequencies(TOFs)of 0.23 h^(-1)per Ov site and 3.97 h^(-1)per Cu(I)site,respectively.We also concluded that neither Cu(I)nor Ov can function independently;both Cu(I)and Ov are required for CO_(2)activation and ethanol formation.Operando Fourier-transform infrared(FTIR)spectroscopy and density functional theory(DFT)calculations identify CH_(2)OH^(*)and CH_(2)^(*)as key intermediates in the C-C coupling step.These findings establish a mechanistic framework for CO_(2)hydrogenative coupling and provide valuable insights for designing more efficient catalysts for ethanol synthesis from CO_(2)conversion.展开更多
Atomically thin Pt nanolayers were synthesized on the surface of Mo2TiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemica...Atomically thin Pt nanolayers were synthesized on the surface of Mo2TiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical industry.As compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(TOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and propylene.The unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is negligible.It is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst stability.The metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.展开更多
The progression toward automated driving and the latest advancement in vehicular networking have led to novel and natural human-vehicle-road systems,in which affective human-vehicle interaction is a crucial factor aff...The progression toward automated driving and the latest advancement in vehicular networking have led to novel and natural human-vehicle-road systems,in which affective human-vehicle interaction is a crucial factor affecting the acceptance,safety,comfort,and traffic efficiency of connected and automated vehicles(CAVs).This development has inspired increasing inter-est in how to develop affective interaction framework for intelligent cockpit in CAVs.To enable affective human-vehicle interactions in CAVs,knowledge from multiple research areas is needed,including automotive engineering,transportation engineering,human-machine interaction,computer science,communication,as well as industrial engineering.However,there is currently no systematic survey considering the close relationship between human-vehicle-road and human emotion in the human-vehicle-road coupling process in the CAV context.To facilitate progress in this area,this paper provides a comprehensive literature survey on emotion-related studies from multi-aspects for better design of affective interaction in intelligent cockpit for CAVs.This paper discusses the multimodal expression of human emotions,investigates the human emotion experiment in driving,and particularly emphasizes previous knowledge on human emotion detection,regulation,as well as their applications in CAVs.The promising research perspectives are outlined for researchers and engineers from different research areas to develop CAVs with better acceptance,safety,comfort,and enjoyment for users.展开更多
A reduction in building occupancy can lead to stagnant water in plumbing,and the potential consequences for water quality have gained increasing attention.To investigate this,a study was conducted during the COVID-19 ...A reduction in building occupancy can lead to stagnant water in plumbing,and the potential consequences for water quality have gained increasing attention.To investigate this,a study was conducted during the COVID-19 pandemic,focusing on water quality in four institutional buildings.Two of these buildings were old(>58 years)and large(>19,000 m2),while the other two were new(>13 years)and small(<11,000 m2).The study revealed significant decreases in water usage in the small buildings,whereas usage remained unchanged in the large buildings.Initial analysis found that residual chlorine was rarely detectable in cold/drinking water samples.Furthermore,the pH,dissolved oxygen,total organic carbon,and total cell count levels in the first draw of cold water samples were similar across all buildings.However,the ranges of heavy metal concentrations in large buildings were greater than observed in small buildings.Copper(Cu),lead(Pb),and manganese(Mn)sporadically exceeded drinking water limits at cold water fixtures,with maximum concentrations of 2.7 mg Cu L^(-1),45.4 mg Pb L^(-1),1.9 mg Mn L^(-1).Flushing the plumbing for 5 min resulted in detectable residual at fixtures in three buildings,but even after 125 min of flushing in largest and oldest building,no residual chlorine was detected at the fixture closest to the building's point of entry.During the pandemic,the building owner conducted fixture flushing,where one to a few fixtures were operated per visit in buildings with hundreds of fixtures and multiple floors.However,further research is needed to understand the fundamental processes that control faucet water quality from the service line to the faucet.In the absence of this knowledge,building owners should create and use as-built drawings to develop flushing plans and conduct periodic water testing.展开更多
Heterogeneous catalysts constitute a crucial component of many industrial processes,and to gain an understanding of the atomicscale features of such catalysts,ab initio density functional theory is widely employed.Rec...Heterogeneous catalysts constitute a crucial component of many industrial processes,and to gain an understanding of the atomicscale features of such catalysts,ab initio density functional theory is widely employed.Recently,growing computational power has permitted the extension of such studies to complex reaction networks involving either high adsorbate coverages or multidentate adsorbates,which bind to the surface through multiple atoms.Describing all possible adsorbate configurations for such systems,however,is often not possible based on chemical intuition alone.To systematically treat such complexities,we present a generalized Python-based graph theory approach to convert atomic scale models into undirected graph representations.These representations,when combined with workflows such as evolutionary algorithms,can systematically generate high coverage adsorbate models and classify unique minimum energy multidentate adsorbate configurations for surfaces of low symmetry,including multi-elemental alloy surfaces,steps,and kinks.展开更多
基金supported by the East Carolina Christmas Tree Program
文摘Transgenic trees as a new source for biofuel have brought a great interest in tree biotechnology. Genetically modifying forest trees for ethanol production have advantages in technical challenges, costs, environmental concerns, and financial problems over some of crops. Genetic engineering of forest trees can be used to reduce the level of lignin, to produce the fast-growing trees, to develop trees with higher cellulose, and to allow the trees to be grown more widely. Trees can establish themselves in the field with less care of farmers, compared to most of crops. Transgenic crops as a new source for biofuel have been recently reviewed in several reviews. Here, we overview transgenic woody plants as a new source for biofuel including genetically modified woody plants and environment; main focus of woody plants genetic modifications; solar to chemical energy transfer; cellulose biosynthesis; lignin biosynthesis; and cellulosic ethanol as biofuel.
文摘Malonyl-CoA synthetases may modulate cell responses to abiotic stress by regulating stress-related signaling transduction pathways or activating expression of transcription factors.However,the molecular mechanism of cold stress tolerance enhanced by malonyl-CoA synthetase is not fully understood.Here,we report that overexpression of the Arabidopsis thaliana malonyl-CoA synthetase gene AAE13.1 resulted in increased cell viability and growth rate and decreased thiobarbituric acid reactive substances under cold stress in rice(Oryza sativa L.),tobacco(Nicotiana tabacum),and slash pine(Pinus elliottii Engelm.).AAE13.1 was associated with cold stress tolerance by increasing the activity of ascorbate peroxidase,catalase,polyphenol oxidase,and peroxidase and the accumulation of acid phosphatase and alkaline phosphatase.Among six rice mitogenactivated protein kinase(MAPK)genes examined,AAE13.1 overexpression increased the expression of OsMAPK genes during cold stress.AAE13.1 activated expression of stressresponse genes OsMAPK1,OsMAPK2,and OsMAPK3,indicating that AAE13.1 enhances cold stress tolerance by regulating expression of MAPK genes in plant cells.These results increase our understanding of cold stress tolerance in species of monocotyledons,dicotyledons,and gymnosperms.
文摘Although roots are so important for plant growth and crop productivity, the molecular mecha- nism（s） of root formation and growth is not fully under- stood. To increase our understanding of the underlying molecular mechanisms, here we review microRNA regu- lation of processes related to root formation： the regulation of transcription factors, nutrient uptake, stress signaling, and growth signaling. We have summarized the interaction, expression, transport, and signaling events that involve microRNAs in ideal and stressed conditions in a number of model plants, highlighting the involvement of microRNAs in root formation. MicroRNAs are now known to be important players in root initiation, development, and growth; understanding the precise mechanisms involved will be valuable for plant molecular breeding to develop high-yielding crops with high stress resistance and low nutrient requirements.
文摘Due to the shortage supply of propylene and the development of shale gas,there is increased interest in on-purpose propane dehydrogenation(PDH)technology for propylene production.Ga-based catalysts have great potential in PDH,due to the high activity,low carbon deposit and deactivation.Ga-hydrides formed during PDH reduce the rate,selectivity and yield of propylene.In this contribution,CO_(2)is introduced into PDH as a soft oxidant to eliminate the unfavorable intermediate species Ga^(δ+)-Hx re-generating Ga^(3+)-O pairs,and also minimize coke deposition thereby improving the catalytic performance.In situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy experiments show that CO_(2)can effectively eliminate Ga^(δ+)-Hx.At different temperatures,co-feeding CO_(2)during PDH over Ga_(2)O_(3)/SiO_(2)catalysts with different loadings significantly improves the stability of the conversion and selectivity,especially the latter,and provide a new dimension for improving the performance of PDH process.
基金Financial supports from the National Natural Science Foundation of China(no.31901272,no.22075254)the Jiangsu Province Key Laboratory of Biomass Energy and Materials(no.JSBEM-S-201906)。
文摘The development of efficient catalytic electrode toward oxygen reduction reaction(ORR)is still a great challenge for the wide use of zinc–air batteries.Herein,Co_(2)N nanoparticles(NPs)anchored on N-doped carbon from cattail were verified with excellent catalytic performances for ORR.The onset and half-wave potentials over the optimal catalyst reach to 0.96 V and 0.84 V,respectively.Current retention rates of 96.8%after 22-h test and 98.8%after running 1600 s were obtained in 1 M methanol solution.Density functional theory simulation proposes an apparently increased electronic states of Co_(2)N in N-doped carbon layer close to the Fermi level.Higher charge density,favorable adsorption,and charge transfer of intermediates originate from the coexistence of Co_(2)N NPs and N atoms in carbon skeleton.The superior catalytic activity of composites also was confirmed in zinc–air batteries.This novel catalytic property and controllable preparation approach of Co_(2)Ncarbon composites provide a promising avenue to fabricate metal-containing catalytically active carbon from biomass.
文摘RNA-seq and single-cell genomic research emerge as an important research area in the recent years due to its ability to examine genetic information of any number of single cells in all living organisms.The knowledge gained from RNA-seq and single-cell genomic research will have a great impact in many aspects of plant biology.In this review,we summary and discuss the biological significance of RNA-seq and single-cell genomic research in plants including the single-cell DNA-sequencing,RNA-seq and single-cell RNA sequencing in woody plants,methods of RNA-seq and single-cell RNA-sequencing,single-cell RNA-sequencing for studying plant development,and single-cell RNA-sequencing for elucidating cell type composition.We will focus on RNA-seq and single-cell RNA sequencing in woody plants,understanding of plant development through single-cell RNAsequencing,and elucidation of cell type composition via single-cell RNA-sequencing.Information presented in this review will be helpful to increase our understanding of plant genomic research in a way with the power of plant single-cell RNA-sequencing analysis.
文摘Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully understood.Here,Agrobacterium tumefaciens carrying the gene for Arabidopsis thaliana cysteine2/histidine2-type transcription factor 6(ZAT6)was used to engineer rice(Oryza sativa L.),cotton(Gossypium hirsutum L.),and slash pine(Pinus elliottii Engelm.)to generate transgenic cell lines.Transgenic cells were then inoculated with the pathogenic bacterium Pseudomonas syringae.Compared to the control,cell viability of transgenic cells increased 39–47%and growth rate increased 9–15%by 7 days after inoculation in rice,cotton and slash pine.Acid phosphatase activity and alkaline phosphatase activity and transcript levels of Ca 2+-dependent protein kinase genes OsCPK1,OsCPK2,OsCPK6,and OsCPK8 and mitogen-activated protein kinase genes OsMAPK1,OsMAPK2,OsMAPK3,and OsMAPK8 increased signifi cantly in transgenic rice cells by 3 day after inoculation,and extracellular pH had decreased by 10–14%by 96 min after inoculation in transgenic rice,cotton and slash pine cells.These results suggest that ZAT6 enhances P.syringae resistance in plant cells by modulating transcription of CPK and MAPK and oxidase activity.
文摘Well-established targeted technologies to engi- neer genomes such as zinc-finger nuclease-based editing （ZFN）, transcription activator-like effector nuclease-based editing （TALEN）, and clustered regularly interspaced short palindromic repeats and associated protein system-based editing （CRISPR/Cas） are proving to advance basic and applied research in numerous plant species. Compared with systems using ZFNs and TALENs, the most recently developed CRISPR/Cas system is more efficient due to its use of an RNA-guided nuclease to generate double-strand DNA breaks. To accelerate the applications of these technologies, we provide here a detailed overview of these systems, highlight the strengths and weaknesses of each, summarize research advances made with these technologies in model and crop plants, and discuss their applications in plant functional genomics. Such targeted approaches for genetically modifying plants will benefit agricultural production in the future.
基金Supported in part by Purdue University and research grants:R01 CA115883 A2(S.L.)from National Cancer Institute,R21 EB003419-02(S.L.)+1 种基金from National Institute of Biomedical Imaging and Bioengineering and R21 HL083961-01from National Heart,Lung,and Blood Institute
文摘Ischemia-related diseases,particularly coronary artery disease(CAD),account for the majority of deaths worldwide.Myocardial ischemia is a serious condition and the delay in reperfusion of ischemic tissues can be life-threatening.This is particular true in the aged population.Rapid and accurate early detection of myocardial ischemia is highly desirable so that various therapeutic regiments can be given before irreversible myocardial damage occurs.Myocardial perfusion imaging with radiotracers is an integral component in evaluations of patients with known or suspected CAD. 99m Tc-Sestamibi and 99m Tc-Tetrofosmin are commercial radiopharmaceuticals currently available for myocardial perfusion imaging.Despite their widespread clinical applications,both 99m Tc-Sestamibi and 99m Tc-Tetrofosmin do not meet the requirements of an ideal perfusion imaging agent,largely due to their high liver uptake.The intense liver uptake makes it difficultto interpret the heart activity in the inferior and left ventricular wall.Photon scattering from the high liver radioactivity accumulation remains a significant challenge for diagnosis of heart diseases.This review will summarize the most recent research efforts to minimize the liver uptake of cationic 99m Tc radiotracers by using ether and crown ether-containing chelators. Fast liver clearance will shorten the duration of imaging protocols(<30 min post-injection) ,and allow for early acquisition of heart images with high quality. Improvement of heart/liver ratio may permit better detection of the presence and extent of coronary artery disease.Identification of such a new radiotracer that allows for the improved noninvasive assessment of myocardial perfusion would be of considerable benefit in treatment of patients with suspected CAD.
文摘Genome editing is a valuable tool to target specific DNA sequences for mutagenesis in the genomes of microbes, plants, and animals. Although different genome editing technologies are available, the clustered regularly interspaced short palindromic repeats/Cas9 （CRISPR/ Cas9） system, which utilizes engineered endonucleases to generate a double-stranded DNA break （DSB） in the target DNA region and subsequently stimulates site-specific mutagenesis through DNA repair machineries, is emerging as a powerful genome editing tool for elucidating mecha- nisms of protection from plant viruses, plant disease resistance, and gene functions in basic and applied research. In this review, we provide an overview of recent advances in the CRISPR system associated genome editing in plants by focusing on application of this technology in model plants, crop plants, fruit plants, woody plants and grasses and discuss how genome editing associated with the CRISPR system can provide insights into genome modifications and functional genomics in plants.
基金supported by the National Natural Science Foundation of China(Nos.21377164,21507159)the Chinese Universities Scientific Fund(Nos.2018QC200 and 2015QC091)。
文摘Volatile organic chloramines are reported as the disinfection byproducts during chlorination or chloramination.However,ClO2,as an important alternative disinfectant for chlorine,was not considered to produce halogenated amines.In the present work,volatile organic chloramines including(CH3)2 NCl and CH3 NCl2 were found to be generated during the reaction of ClO2 and the dye pollutants.(CH3)2 NCl was the dominant volatile DBP to result from ClO2 treated all four dye pollutants including Methyl Orange,Methyl Red,Methylene Blue and Malachite Green,with molar yields ranging from 2.6%to 38.5%at a ClO2 to precursor(ClO2/P)molar ratio of 10.HOCl was identified and proved to be the reactive species for the formation of(CH3)2 NCl,which implied(CH3)2 NCl was transformed by a combined oxidation of ClO2 and hypochlorous acid.(CH3)2 NCl concentrations in the ppb range were observed when real water samples were treated by ClO2 in the presence of the dye pollutants.The results suggest that these azo dyes are one of the significant precursors for the formation of HOCl during ClO2 treatment and that organic chloramines should be considered in ClO2 disinfection chemistry and water treatment.
基金financially supported by the National Natural Science Foundation of China (Nos. 51303028, 31771893, and 31401609)the Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University (No. SKLPEE-KF201720)
文摘In this work,poly(vinylidene fluoride)(PVDF)membranes with hydrophilicity as well as preeminent mechanical strength and dye removal efficiency were fabricated by blending with three dimensional hydroxyapatite nanoparticles(HAPNPs).Surface chemical composition and morphology of the prepared membranes were systematically investigated by ATR-FTIR,XPS,XRD,FESEM,and EDS mapping analyses.The results verified that a large number of HAPNPs were successfully embedded on the modified membrane crosssections.Moreover,HAPNPs content in the casting solution is an important factor that could have profound influence on the structures and performances of PVDF/HAPNPs blend membranes.The optimal membrane M2 with 2 wt%HAPNPs exhibited excellent hydrophilicity,outstanding mechanical strength of 19.60 MPa,and high water flux of(2466±31)L·m^2·h^-1.The maximum static adsorption capacity of the optimal membrane was about 10.83 mg/g,which is 3.75 times that of the pristine PVDF membrane(2.89 mg/g).PVDF/HAPNPs membranes were not only utilized for static adsorption,but also applied to dynamic dye removal.The possible adsorption mechanism between Congo red(CR)and HAPNPs embedded on the blend membranes was firstly discussed in this work.HAPNPs interacted with CR via Lewis reaction,hydrogen bond interaction,as well as electrostatic attraction to achieve the adsorption effect.Herein,the PVDF/HAPNPs blend membranes with extraordinary hydrophilicity,mechanical strength,and dye removal efficiency possess tremendous potential for practical applications of wastewater treatment.
文摘The protection of classical or significant reference stratigraphic sections of the nation’s valuable geoheritage has become a priority by the Chinese government and national stratigraphic commission.The process for the protection and documentation of stratigraphic sections includes:(1)marked tablets showing the standardized bed,member and formation divisions and,where applicable,standardized meter intervals for future investigations;(2)a monument or other on-site interpretive information;and(3)field guides for different audiences summarizing its importance with maps and detailed descriptions.In particular,the ten Global Stratotype Sections and Points(GSSPs)established in southern China are well preserved and managed;and some are now within tourist-friendly educational national geoparks.We suggest that other national stratigraphic commissions might incorporate some of the experiences from China’s current efforts to preserve and standardize important reference sections for Earth history research.
文摘Purpose This study compared the acute effects of a session of isometric strength training(ISO)with heavy resistance training(HRT)training on 20-m sprint,countermovement jump(CMJ)and isometric mid-thigh pull(IMTP)performance.Methods Ten resistance-trained athletes(age:26.7±6.2 years,body mass:71.5±16.2 kg,height:1.68±0.10 m)performed baseline measures for 20-m sprint,CMJ and IMTP prior to either an ISO or HRT session.During both training sessions,participants performed back squats,Romanian deadlift and split squat.Post-test performances were measured 5 min and 24 h after each training session.Participants returned a week later to perform the other training session.Results A significant time×condition effect was found for 20-m sprint time(P=0.007)and IMTP peak force(P=0.003).Main time effect was observed for 20-m sprint(P<0.001),CMJ height(P<0.001)and IMTP peak force(P<0.001).HRT resulted in a greater increase in sprint time at 5 min(0.17±0.12 vs.0.06±0.05 s,P=0.013,g=1.15)and 24 h(0.01±0.09 vs.0.00±0.05 s,P=0.004,g=1.32)post-training as compared to ISO.Similarly,HRT resulted in a significantly larger reduction in IMTP peak force than ISO at both 5 min(-363.3±248.8 vs.-98.9±230.3 N,P=0.024,g=1.06)and 24 h(-289.2±256.2 vs.37.9±177.8 N,P=0.004,g=1.42)post-training.Total impulses generated during each exercise were greater during ISO than HRT(P<0.001–0.006).Rating of perceived recovery post 24 h was higher in ISO than HRT(P=0.002).Conclusion The above results indicated that acute HRT led to a greater reduction in sprinting strength performance and lower perceived recovery post-24 h than ISO.
基金supported in part by the U.S.National Science Foundation under grant(No.OIA-1946231)the Louisiana Board of Regents for the Louisiana Materials Design Alliance(LAMDA)Y.W.,P.L.H.,F.Y.acknowledge financial support from Y.W.’s Herbert L.Stiles Professorship.
文摘Hydrogenative coupling of CO_(2)to ethanol presents a sustainable pathway for carbon neutralization,yet the fundamental active sites and reaction pathway/mechanism remain unclear.Here,we investigate CO_(2)hydrogenative coupling over Cu/CeO_(2-x)catalysts,achieving an optimal CO_(2)conversion of~5%and ethanol selectivity of~95%under 30 atm,H_(2)/CO_(2)=3,at 240℃,and gas hourly space velocity(GHSV)=120 mL·gcat^(-1)·h^(-1).We revealed that both Cu(I)and oxygen vacancies(Ov)serve as active sites,with turnover frequencies(TOFs)of 0.23 h^(-1)per Ov site and 3.97 h^(-1)per Cu(I)site,respectively.We also concluded that neither Cu(I)nor Ov can function independently;both Cu(I)and Ov are required for CO_(2)activation and ethanol formation.Operando Fourier-transform infrared(FTIR)spectroscopy and density functional theory(DFT)calculations identify CH_(2)OH^(*)and CH_(2)^(*)as key intermediates in the C-C coupling step.These findings establish a mechanistic framework for CO_(2)hydrogenative coupling and provide valuable insights for designing more efficient catalysts for ethanol synthesis from CO_(2)conversion.
基金support from Iowa State University(Herbert L.Stiles Professorship).Y.X.and T.K.M.appreciate the start-up funding from the College of Engineering and Science at Louisiana Tech University.Z.W.W.and J.T.M.were supported by the National Science Foundation under Cooperative Agreement(NSF/ERC CISTAR,No.EEC-164772)Use of the Advanced Photon Source,a US Department of Energy Office of Basic Energy Sciences,was supported under contract no.DE-AC02-06CH11357.
文摘Atomically thin Pt nanolayers were synthesized on the surface of Mo2TiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical industry.As compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(TOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and propylene.The unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is negligible.It is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst stability.The metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.
基金supported by Natural Science Foundation of China(52302497,52272420)。
文摘The progression toward automated driving and the latest advancement in vehicular networking have led to novel and natural human-vehicle-road systems,in which affective human-vehicle interaction is a crucial factor affecting the acceptance,safety,comfort,and traffic efficiency of connected and automated vehicles(CAVs).This development has inspired increasing inter-est in how to develop affective interaction framework for intelligent cockpit in CAVs.To enable affective human-vehicle interactions in CAVs,knowledge from multiple research areas is needed,including automotive engineering,transportation engineering,human-machine interaction,computer science,communication,as well as industrial engineering.However,there is currently no systematic survey considering the close relationship between human-vehicle-road and human emotion in the human-vehicle-road coupling process in the CAV context.To facilitate progress in this area,this paper provides a comprehensive literature survey on emotion-related studies from multi-aspects for better design of affective interaction in intelligent cockpit for CAVs.This paper discusses the multimodal expression of human emotions,investigates the human emotion experiment in driving,and particularly emphasizes previous knowledge on human emotion detection,regulation,as well as their applications in CAVs.The promising research perspectives are outlined for researchers and engineers from different research areas to develop CAVs with better acceptance,safety,comfort,and enjoyment for users.
文摘A reduction in building occupancy can lead to stagnant water in plumbing,and the potential consequences for water quality have gained increasing attention.To investigate this,a study was conducted during the COVID-19 pandemic,focusing on water quality in four institutional buildings.Two of these buildings were old(>58 years)and large(>19,000 m2),while the other two were new(>13 years)and small(<11,000 m2).The study revealed significant decreases in water usage in the small buildings,whereas usage remained unchanged in the large buildings.Initial analysis found that residual chlorine was rarely detectable in cold/drinking water samples.Furthermore,the pH,dissolved oxygen,total organic carbon,and total cell count levels in the first draw of cold water samples were similar across all buildings.However,the ranges of heavy metal concentrations in large buildings were greater than observed in small buildings.Copper(Cu),lead(Pb),and manganese(Mn)sporadically exceeded drinking water limits at cold water fixtures,with maximum concentrations of 2.7 mg Cu L^(-1),45.4 mg Pb L^(-1),1.9 mg Mn L^(-1).Flushing the plumbing for 5 min resulted in detectable residual at fixtures in three buildings,but even after 125 min of flushing in largest and oldest building,no residual chlorine was detected at the fixture closest to the building's point of entry.During the pandemic,the building owner conducted fixture flushing,where one to a few fixtures were operated per visit in buildings with hundreds of fixtures and multiple floors.However,further research is needed to understand the fundamental processes that control faucet water quality from the service line to the faucet.In the absence of this knowledge,building owners should create and use as-built drawings to develop flushing plans and conduct periodic water testing.
基金J.G.,S.D.,and T.M.acknowledge the United States Department of Energy through the Office of Science,Office of Basic Energy Sciences(BES),Chemical,Biological,and Geosciences Division,Data Science Initiative,Grant DE-SC0020381.
文摘Heterogeneous catalysts constitute a crucial component of many industrial processes,and to gain an understanding of the atomicscale features of such catalysts,ab initio density functional theory is widely employed.Recently,growing computational power has permitted the extension of such studies to complex reaction networks involving either high adsorbate coverages or multidentate adsorbates,which bind to the surface through multiple atoms.Describing all possible adsorbate configurations for such systems,however,is often not possible based on chemical intuition alone.To systematically treat such complexities,we present a generalized Python-based graph theory approach to convert atomic scale models into undirected graph representations.These representations,when combined with workflows such as evolutionary algorithms,can systematically generate high coverage adsorbate models and classify unique minimum energy multidentate adsorbate configurations for surfaces of low symmetry,including multi-elemental alloy surfaces,steps,and kinks.
