Based on four phases of TM images acquired in 1990, 1995, 2000 and 2005, this paper took Kitakyushu in Japan as a case study to analyze spatial change of land use landscape and corresponding effects on environmental i...Based on four phases of TM images acquired in 1990, 1995, 2000 and 2005, this paper took Kitakyushu in Japan as a case study to analyze spatial change of land use landscape and corresponding effects on environmental issues guided by landscape ecology theory in virtue of combining technology of Remote Sensing with GIS. Firstly, land use types were divided into 6 classes （farmland, mountain, forestland, water body, urban land and unused land） according to national classification standard of land use, comprehensible ability of TM image and purpose of this study. Secondly, following the theory of landscape ecology analysis, 11 typical landscape indices were abstracted to evaluate the environmental effects and spatial feature changes of land use. Research results indicated that land use has grown more and more diversified and unbalanced, human activities have disturbed the landscape more seriously. Finally, transfer matrix of Markov was applied to forecast change process of land use in the future different periods, and then potential land use changes were also simulated from 2010 to 2050. Results showed that conversion tendency for all types of land use in Kitakyushu into urban construction land were enhanced. The study was anticipated to help local authorities better understand and address a complex land use system, and develop improved land use management strategies that could better balance urban expansion and ecological conservation.展开更多
Terpenoids are the largest and most diverse class of plant-specialized metabolites, which function in diverse physiological processes during plant development. In the biosynthesis of plant terpenoids, short-chain pren...Terpenoids are the largest and most diverse class of plant-specialized metabolites, which function in diverse physiological processes during plant development. In the biosynthesis of plant terpenoids, short-chain prenyltransferases （SC-PTs）, together with terpene synthases （TPSs）, play critical roles in determining terpenoid diversity. SC-PTs biosynthesize prenyl pyrophosphates with different chain lengths, and these compounds are the direct precursors of terpenoids. Arabidopsis thaliana possesses a subgroup of SC-PTs whose functions are not clearly known. In this study, we focus on 10 geranylgeranyl pyro- phosphate synthase-like [GGPPSL] proteins, which are commonly thought to produce GGPP [C20]. We found that a subset of members of the Arabidopsis GGPPSL gene family have undergone neo- functionalization： GGPPSL6, 7, 9, and 10 mainly have geranylfarnesyl pyrophosphate synthase activity （C25; renamed AtGFPPS1, 2, 3, and 4）, and GGPPSL8 produces even longer chain prenyl pyrophosphate （〉C30; renamed polyprenyl pyrophosphate synthase 2, AtPPPS2）. By solving the crystal structures of AtGFPPS2, AtPPPS2, and AtGGPPS11, we reveal the product chain-length determination mechanism of SC-PTs and interpret it as a ＂three floors＂ model. Using this model, we identified a novel GFPPS clade distributed in Brassicaceae plants and found that the GFPPS gene typically occurs in tandem with a gene encoding a TPS, forming a GFPPS-TPS gene cluster.展开更多
Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high...Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high efficiency,excellent thermal stability and high colour purity is still a challenge.In this work,unique non-concentration quenching in solid-solution Cs_(3)Gd_(1-x)Ge_(3)O_(9):xEu^(3+)(CGGO:xEu^(3+))(x=0.1-1.0)phosphors is successfully developed to achieve a highly efficient red-emitting Cs_(3)EuGe_(3)0_(9)(CEGO)phosphor.Under the optimal 464 nm blue light excitation,CEGO shows a strong red emission at 611 nm with a high colour purity of 95.07%and a high internal quantum efficiency of 94%.Impressively,this red-emitting CEGO phosphor exhibits a better thermal stability at higher temperatures(175-250℃,>90%)than typical red K2SiF6:Mn^(4+)and Y203:Eu^(3+)phosphors,and has a remarkable volumetric negative thermal expansion(coefficient of thermal expansion,a=—5.06×10^(-5)/℃,25-250℃).By employing this red CEGO phosphor,a fabricated pc-WLED emits warm white light with colour coordinates(0.364,0.383),a high colour rendering index(CRI=89.7),and a low colour coordinate temperature(CCT=4508 K).These results indicate that this highly efficient red-emitting phosphor has great potential as a red component for pc-WLEDs,opening a new perspective for developing new phosphor materials.展开更多
Non-pillar mining,top-coal caving and protected coal seam mining are the most popular mining methods in coal exploitation,and the different mining layouts will change the stress state and failure mechanism of coal in ...Non-pillar mining,top-coal caving and protected coal seam mining are the most popular mining methods in coal exploitation,and the different mining layouts will change the stress state and failure mechanism of coal in front of the working face.In this paper,mining-induced mechanical behaviors under three mining layouts have been simulated in the laboratory to investigate the effects of mining layouts on the deformation and strength of coal.Furthermore,the coal failure mechanism under different mining layouts is analyzed microscopically.The experimental results indicate that the stage characteristics of the coal deformation are obvious.Under the serial action of non-pillar mining,top-coal caving and protected coal seam mining layouts,the values of radial deformation,volume strain and Poisson's ratio increase,while the peak strength and deformation modulus decrease at the same buried depth,and the peak strength under non-pillar mining,top-coal caving and protected coal seam mining is about 3.0,2.5 and 2.0 times of the initial confining pressure,respectively.The results also indicate that the trend of the coal deformation decreases with the increase of the buried depth under the same mining layout,while the strength and deformation modulus increase,and the failure mechanism under three mining layouts is dominated with shear/tensile failure.展开更多
Dear Editor,Monoterpenes, together with sesquiterpenes, play varying roles in plant interactions with the environment depending on the organs in which they are produced; these compounds likely function to attract poll...Dear Editor,Monoterpenes, together with sesquiterpenes, play varying roles in plant interactions with the environment depending on the organs in which they are produced; these compounds likely function to attract pollinators when they are present in flowers and can protect plants against herbivores or microbes when produced in leaves or in roots. It is well known that geranyl diphosphate （GPP）, the common precursor of monoterpenes, is biosynthesized by geranyl diphosphate synthase （GPPS）. To date, two types of GPPS （EC 2.5.1.1） have been reported from plants： homomeric GPPS and heteromeric GPPS. Heteromeric GPPS is composed of one inactive small subunit （SSU; SSUs can be divided into two types： SSU I and SSU II） and one large subunit （LSU） （Burke et al., 1999; Tholl et al., 2004; Wang and Dixon, 2009）. In the Arabidopsis genome, there are 12 GGPPS paralogs and one homomeric GPPS gene （At2g34630） （Bouvier et al., 2000; Lange and Ghassemian, 2003; Beck et al., 2013）. A previous in vitro study characterized a heteromeric G（G）PS composed of GGPPS12 （also known as AtSSU, encoded by At4g38460 and belonging to the type II SSU type） and GGPPS11 （also known as AtLSU, encoded by At4g36810） （Wang and Dixon, 2009）. However, there is controversy as to which type of GPPS is involved in monoterpene biosynthesis in Arabidopsis. This controversy stems from the fact that both homomeric and heteromeric GPPS enzyme complexes catalyze the condensation of dimethylallyl pyrophosphate （DMAPP） and isopentenyl pyrophosphate （IPP） to form GPP when assayed in vitro （Bouvier et al., 2000; Wang and Dixon, 2009）. In the study reported here, we comprehensively analyzed transgenic GGPPS12, GGPPS11, and GPPS Arabidopsis plants and provide solid genetic evidence to support the supposition that heteromeric G（G）PPS, and not homomeric GPPS, is involved in monoterpene biosynthesis, at least in the flowers of Arabidopsis.展开更多
Gecko's excellent adhesion ability is thought to derive from van der Waals force generated between the millions of keratinous hairs/setae and the contact surface.Fabricating highly gecko-inspired foot-hair becomes...Gecko's excellent adhesion ability is thought to derive from van der Waals force generated between the millions of keratinous hairs/setae and the contact surface.Fabricating highly gecko-inspired foot-hair becomes one of the key technologies to realize the three-dimensional-obstacle-free motion of robot.Researchers have fabricated various gecko-like foot-hair arrays which have leaning,large end,and hierarchical structures.Those significant works are summarized and suggestions for future work are proposed in this paper.展开更多
The exploitation of coal bed methane or coal gas is one of the most effective solutions of the problem of coal gas hazard.A better understanding of gas flow in mining-induced cracks plays an important role in comprehe...The exploitation of coal bed methane or coal gas is one of the most effective solutions of the problem of coal gas hazard.A better understanding of gas flow in mining-induced cracks plays an important role in comprehensive development and utilization of coal gas as well as prevention of coal gas hazard.This paper presents a case study of gas flow in mining-induced crack network regarding the situation of low permeability of coal seam.A two-dimensional physical model is constructed on the basis of geological background of mining face No.1122(1) in coal seam No.11-2,Zhangji Coal Mine,Huainan Mining Group Corporation.The mining-induced stress and cracks in overburden rocks are obtained by simulating an extraction in physical model.An evolution of mining-induced cracks in the process of advancing of coal mining face is characterized and three typical crack networks are taken from digital photos by means of image analysis.Moreover,the numerical software named COMSOL Multiphysics is employed to simulate the process of gas flow in three representative crack networks.Isograms of gas pressure at various times in mining-induced crack networks are plotted,suggesting a shape and dimension of gas accumulation area.展开更多
This paper aims to conduct a comprehensive review of rural solid waste （RSW） in terms of character- istics, management and legislation. Survey results show that RSW generation rates range from 0.25 to 2.1 kg · ...This paper aims to conduct a comprehensive review of rural solid waste （RSW） in terms of character- istics, management and legislation. Survey results show that RSW generation rates range from 0.25 to 2.1 kg · （capita.d）-1 in different rural villages across regions of China. Total RSW generation has been increasing, which is far higher than official data in 2014. RSW are dominated by food residue and coal ash/cinder/dust （at approximately 70%）. Most of RSW are still discarded randomly without any treatment in China. Scattered RSW generation sources, imperfect legislation system, poor infrastructure on treat- ment and disposal are identified as the biggest challenge for RSW management currently in China. To improve RSW management, increasing financial resources, estab- lishing sorting collection and transportation network, promoting sorting collection and recycling, improving treatment technology are proposed as the possible solution.展开更多
Macrophages play critical roles in renal fibrosis.However,macrophages exhibit ontogenic and functional heterogeneities,and which population of macrophages contributes to renal fibrosis and the underlying mechanisms re...Macrophages play critical roles in renal fibrosis.However,macrophages exhibit ontogenic and functional heterogeneities,and which population of macrophages contributes to renal fibrosis and the underlying mechanisms remain unclear.In this study,we genetically targeted Notch signaling by disrupting the transcription factor recombination signal binding protein-JK(RBP-J),to reveal its role in regulation of macrophages during the unilateral ureteral obstruction(UUO)-induced murine renal fibrosis.Myeloid-specific disruption of RBP-J attenuated renal fibrosis with reduced extracellular matrix deposition and myofibroblast activation,as well as attenuated epithelial-mesenchymal transition,likely owing to the reduced expression of TGF-β.Mean while,RBP-J deletion significantly hampered macrophage infiltration and activation in fibrotic kidney,although their proliferation appeared unaltered.By using macrophage clearance experiment,we found that kidney resident macrophages made negligible contribution,but bone marrow(BM)-derived macrophages played a major role in renal fibrogenesis.Further mechanistic analyses showed that Notch blockade reduced monocyte emigration from BM by down-regulating CCR2 expression.Finally,we found that myeloid-specific Notch activation aggravated renal fibrosis,which was mediated by CCR2^+macrophages infiltration.In summary,our data have unveiled that myeloid-specific targeting of Notch could ameliorate renal fibrosis by regulating BM-derived macrophages recruitment and activation,providing a novel strategy for intervention of this disease.展开更多
This paper reports a new technique to fabricate an ion-exchange polymer-metal composite (IPMC) actuator. This technique is based on a hybrid organic-inorganic composite membrane. In the fabrication course, silica oxid...This paper reports a new technique to fabricate an ion-exchange polymer-metal composite (IPMC) actuator. This technique is based on a hybrid organic-inorganic composite membrane. In the fabrication course, silica oxide particles, prepared from hydrolysis of tetraethyl orthosilicate in situ with sol-gel reaction, co-crystallize with perfluorosulfonate acid (PFSA) ionomer. Attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) analyses demonstrate that a highly water-saving hybrid membrane is formed. Measurements of mechanical properties reveal that elastic modulus and hardness of the hybrid membrane are about 2 times compared to a commercial PFSA membrane. Scanning electron microscopy (SEM) results show that the hybrid membrane has a high porosity. Inside the membrane pores, there exists a great quantity of micro scale channels in the range of 100―300 nm. After fabrication of IPMC actuator, an electric current sensor, a force sensor, and a high speed camera are assembled and used to evaluate IPMC performance. It is shown that, compared to an IPMC actuator made from a commercial membrane, the electromechanical performance of the new actuator increases 6―8 times; when it is actuated in air, its stable non-water working time is prolonged for 6―7 times.展开更多
Self-powerability is a new trend in the development of portable devices.Harvesting biomechanical energy to power personal information electronics is of great significance.In this work,we report a wearable noncontact f...Self-powerability is a new trend in the development of portable devices.Harvesting biomechanical energy to power personal information electronics is of great significance.In this work,we report a wearable noncontact freerotating hybrid nanogenerator(WRG),which is constituted by a triboelectric nanogenerator and an electromagnetic generator.A continuous output over 2 seconds can be achieved during one instantaneous incentive by external force,which is improved by two orders of magnitude compared to other wearable nanogenerators due to its unique mechanical energy storage design.The WRG can be integrated into shoes to generate an output energy of 14.68 mJ in each stepping,which meets the power requirements of most personal information electronics.The wireless sensor,GPS,and smartphone can be powered by the WRG continuously.The WRG is expected to be applied in self-powered information electronics extensively in the future.展开更多
Using lightning observations from the Fengyun-4A Lightning Mapping Imager(FY-4A LMI),best-track data from the Shanghai Typhoon Institute,bright temperature(TBB)data from Himawari-8 satellite,and composite reflectivity...Using lightning observations from the Fengyun-4A Lightning Mapping Imager(FY-4A LMI),best-track data from the Shanghai Typhoon Institute,bright temperature(TBB)data from Himawari-8 satellite,and composite reflectivity(CR)data from the South China radar network,we investigate the spatiotemporal distribution of lightning activity and convective evolution during the landfall of Super Typhoon Mangkhut,the strongest landing typhoon in China in2018.Three stages of active total lightning are observed,and differences of lightning characteristics between the inner core and the outer rainbands are present.The onset of inner-core lightning outbreak is about 4 h ahead of the maximum intensity of the storm,providing indicative information on the change of typhoon intensity.Lightning rates in the outer rainbands increase rapidly 12 h before the landfall,and lightning activity is mainly confined in the outer rainbands after the landfall.A good correlation in hourly variation is shown between lightning rates from the LMI and TBBs from the satellite.The averaged TBB within the inner core reaches its minimum(–80℃)when the innercore lightning outbreak occurs,indicating the occurrence and enhancement of deep convection there.Lightning locations observed by the LMI has a good spatial correspondence with regions of low TBBs and high CRs,revealing the monitoring capability of the LMI to lightning activity and deep convection in landing typhoons.Comparisons between the World Wide Lightning Location Network(WWLLN)and the LMI reveal that the spatial distribution,temporal evolution,and radial pattern of lightning activity in Mangkhut observed by the two systems are consistent.Furthermore,due to the detection capability of total lightning,the LMI has advantages in revealing the higher ratio of intra-cloud lightning within the inner core in typhoon.The continuous and real-time observation ofFY-4ALMI provides an unprecedented platform for monitoring total lightning and deep convection in landing typhoons in China,which will promote the ge展开更多
Metabolic-associated fatty liver disease(MAFLD),which is previously known as non-alcoholic fatty liver disease(NAFLD),represents a major health concern worldwide with limited therapy.Here,we provide evidence that ferr...Metabolic-associated fatty liver disease(MAFLD),which is previously known as non-alcoholic fatty liver disease(NAFLD),represents a major health concern worldwide with limited therapy.Here,we provide evidence that ferroptosis,a novel form of regulated cell death characterized by iron-driven lipid peroxidation,was comprehensively activated in liver tissues from MAFLD patients.The canonical-GPX4(cGPX4),which is the most important negative controller of ferroptosis,is downregulated at protein but not mRNA level.Interestingly,a non-canonical GPX4 transcript-variant is induced(inducible-GPX4,iGPX4)in MAFLD condition.The high fat-fructose/sucrose diet(HFFD)and methionine/choline-deficient diet(MCD)-induced MAFLD pathologies,including hepatocellular ballooning,steatohepatitis andfibrosis,were attenuated and aggravated,respectively,in cGPX4-and iGPX4-knockin mice.cGPX4 and iGPX4 isoforms also displayed opposing effects on oxidative stress and ferroptosis in hepatocytes.Knockdown of iGPX4 by siRNA alleviated lipid stress,ferroptosis and cell injury.Mechanistically,the triggered iGPX4 interacts with cGPX4 to facilitate the transformation of cGPX4 from enzymatic-active monomer to enzymatic-inactive oligomers upon lipid stress,and thus promotes ferroptosis.Co-immunoprecipitation and nano LC–MS/MS analyses confirmed the interaction between iGPX4 and cGPX4.Our results reveal a detrimental role of non-canonical GPX4 isoform in ferroptosis,and indicate selectively targeting iGPX4 may be a promising therapeutic strategy for MAFLD.展开更多
The newly discovered large(350 m^2) Yantan dinosaur tracksite, in the Lower Jurassic Ziliujing Formation of Guizhou Province, China, reveals at least 250 footprints of which ~97 can be resolved into trackways of sauro...The newly discovered large(350 m^2) Yantan dinosaur tracksite, in the Lower Jurassic Ziliujing Formation of Guizhou Province, China, reveals at least 250 footprints of which ~97 can be resolved into trackways of sauropodomorphs. All the trackways are sub parallel likely indicating gregarious behavior. One theropod track(cf. Grallator) was recorded. The sauropodomorph tracks predominantly represent quadrupedal progression(Morphotype A), and footprint morphology is similar to the ichnospecies Liujianpusshunan, characterized by outward pes rotation. Three trackways indicate bipedal progression, and two of these(Morphotype B) indicate inward pes rotation, accompanied by elongate pes digit scratch marks. For the latter phenomenon three possible scenarios are discussed:(1) significant rotation changes accompanying changes in gait,(2) swimming behavior,(3) formation of undertracks.Sedimentological evidence indicates the tracks were made on a linguloid rippled, muddy, immature sandstone substrate characterized by significant differences in substrate consistency across the trackbearing surface. Microbially induced sedimentary structures(MISS) characterized by distinctive wrinkle marks indicate a stressed, probably semi-arid, paleoenvironment that was not conducive to habitation by invertebrate organisms. This is consistent with other evidence that Lower Jurassic sauropodomorph tracks are often associated with semi-arid paleoenvironments.展开更多
Natural fracture data from one of the Carboniferous shale masses in the eastern Qaidam Basin were used to establish a stochastic model of a discrete fracture network and to perform discrete element simulation research...Natural fracture data from one of the Carboniferous shale masses in the eastern Qaidam Basin were used to establish a stochastic model of a discrete fracture network and to perform discrete element simulation research on the size efect and mechanical parameters of shale.Analytical solutions of fctitious joints in transversely isotropic media were derived,which made it possible for the proposed numerical model to simulate the bedding and natural fractures in shale masses.The results indicate that there are two main factors infuencing the representative elementary volume(REV)size of a shale mass.The frst and most decisive factor is the presence of natural fractures in the block itself.The second is the anisotropy ratio:the greater the anisotropy is,the larger the REV.The bedding angle has little infuence on the REV size,whereas it has a certain infuence on the mechanical parameters of the rock mass.When the bedding angle approaches the average orientation of the natural fractures,the mechanical parameters of the shale blocks decrease greatly.The REV representing the mechanical properties of the Carboniferous shale masses in the eastern Qaidam Basin were comprehensively identifed by considering the infuence of bedding and natural fractures.When the numerical model size is larger than the REV,the fractured rock mass discontinuities can be transformed into equivalent continuities,which provides a method for simulating shale with natural fractures and bedding to analyze the stability of a borehole wall in shale.展开更多
Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,ne...Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,next-generation Cr^(3+)-free NIR-emitting phosphors with high efficiency and tunable optical properties are highly desired to enrich the types of NIR luminescent materials for different application fields.Here,we report the Fe^(3+)-activated Sr2−yCay(InSb)1−zSn_(2)zO_(6)phosphors that exhibit unprecedented long-wavelength NIR emission.The overall emission tuning from 885 to 1005 nm with broadened full-width at half maximum from 108 to 146 nm was realized through a crystallographic site engineering strategy.The NIR emission was significantly enhanced after complete Ca^(2+)incorporation owing to the substitution-induced lower symmetry of the Fe^(3+)sites.The Ca_(2)InSbO_(6):Fe^(3+)phosphor peaking at 935 nm showed an ultra-high internal quantum efficiency of 87%.The as-synthesized emission-tunable phosphors demonstrated great potential for NIR spectroscopy detection.This work initiates the development of efficient Fe^(3+)-activated broadband NIR-emitting phosphors and opens up a new avenue for designing NIR-emitting phosphor materials.展开更多
In somatic cell nuclear transfer (SCNT) technologies,the donor cell’s nuclei need to be epigenetically reprogrammed for embryonic development. The incomplete reprogramming of donor cell nuclei has been implicated as ...In somatic cell nuclear transfer (SCNT) technologies,the donor cell’s nuclei need to be epigenetically reprogrammed for embryonic development. The incomplete reprogramming of donor cell nuclei has been implicated as a primary reason for the low efficiency of SCNT. DNA methylation is a major epige-netic modification of the genome that regulates crucial aspects of genome function,including estab-lishment of genomic imprinting. In order to make sure whether the DNA methylation reprogramming is efficient in SCNT animals,we analyzed the DNA methylation status of two imprinting genes,H19 and Xist,in lungs of deceased SCNT bovines that died within 48 h of birth using bisulfite sequencing analysis. Our findings demonstrated that cloned bovines showed significantly lower DNA methylation of H19 than controls (P<0.05),and three tested CpGs sites (1,2,3) exhibited unmethylation in one cloned bovine (9C3); however,Xist showed similar DNA methylation levels between clones and con-trols,and both showed hypermethylation (96.11% and 86.67%).展开更多
Achievement of high photoluminescence quantum efficiency and thermal stability is challenging for near-infrared(NIR)-emitting phosphors.Here,we designed a“kill two birds with one stone”strategy to simultaneously imp...Achievement of high photoluminescence quantum efficiency and thermal stability is challenging for near-infrared(NIR)-emitting phosphors.Here,we designed a“kill two birds with one stone”strategy to simultaneously improve quantum efficiency and thermal stability of the NIR-emitting Ca_(3)Y_(2-2x)(ZnZr)_(x)Ge_(3)O_(12):Cr garnet system by chemical unit cosubstitution,and revealed universal structure-property relationship and the luminescence optimization mechanism.The cosubstitution of[Zn^(2+)-Zr^(4+)]for[Y^(3+)-Y^(3+)]played a critical role as reductant to promote the valence transformation from Cr^(4+)to Cr^(3+),resulting from the reconstruction of octahedral sites for Cr^(3+).The introduction of[Zn^(2+)-Zr^(4+)]unit also contributed to a rigid crystal structure.These two aspects together realized the high internal quantum efficiency of 96%and excellent thermal stability of 89%@423 K.Moreover,information encryption with“burning after reading”was achieved based on different chemical resistance of the phosphors to acid.The developed NIR-emitting phosphor-converted light-emitting diode demonstrated promising applications in bio-tissue imaging and night vision.This work provides a new perspective for developing high-performance NIR-emitting phosphor materials.展开更多
Color is an important trait for horticultural crops.Carotenoids are one of the main pigments for coloration and have important implications for photosynthesis in plants and benefits for human health.Here,we identified...Color is an important trait for horticultural crops.Carotenoids are one of the main pigments for coloration and have important implications for photosynthesis in plants and benefits for human health.Here,we identified an APETALA2(AP2)/ETHYLENE RESPONSE FACTOR(ERF)transcription factor named MdAP2-34 in apple(Malus domestica Borkh.).MdAP2-34 expression exhibited a close correlation with carotenoid content in‘Benin Shogun’and‘Yanfu 3’fruit flesh.MdAP2-34 promotes carotenoid accumulation in MdAP2-34-OVX transgenic apple calli and fruits by participating in the carotenoid biosynthesis pathway.The major carotenoid contents of phytoene andβ-carotene were much higher in overexpressing MdAP2-34 transgenic calli and fruit skin,yet the predominant compound of lutein showed no obvious difference,indicating that MdAP2-34 regulates phytoene andβ-carotene accumulation but not lutein.MdPSY2-1(phytoene synthase 2)is a major gene in the carotenoid biosynthesis pathway in apple fruit,and the MdPSY2-1 gene is directly bound and transcriptionally activated by MdAP2-34.In addition,overexpressing MdPSY2-1 in apple calli mainly increases phytoene and total carotenoid contents.Our findings will advance and extend our understanding of the complex molecular mechanisms of carotenoid biosynthesis in apple,and this research is valuable for accelerating the apple breeding process.展开更多
microRNAs (miRNAs)are endogenous small non-coding RNAs that bind to mRNAs and target them for cleavage and/or translational repression,leading to gene silencing.We previously developed short tandem target mimic (STTM)...microRNAs (miRNAs)are endogenous small non-coding RNAs that bind to mRNAs and target them for cleavage and/or translational repression,leading to gene silencing.We previously developed short tandem target mimic (STTM)technology to deactivate endogenous miRNAs in Arabidopsis.Here,we created hundreds of STTMs that target both conserved and species-specific miRNAs in Arabidopsis,tomato,rice,and maize,providing a resource for the functional interrogation of miRNAs.We not only revealed the functions of several miRNAs in plant development,but also demonstrated that tissue-specific inactivation of a few miRNAs in rice leads to an increase in grain size without adversely affecting overall plant growth and development.RNA-seq and small RNAseq analyses of STTM156/157 and STTM165/166 transgenic plants revealed the roles of these miRNAs in plant hormone biosynthesis and activation,secondary metabolism,and ion-channel activity-associated electrophysiology,demonstrating that STTM technology is an effective approach for studying miRNA functions.To facilitate the study and application of STTM transgenic plants and to provide a useful platform for storing and sharing of information about miRNA-regulated gene networks,we have established an online Genome Browser (https://blossom.ffr.mtu.edu/designindex2.php) to display the transcriptomic and miRNAomic changes in STTMinduced miRNA knockdown plants.展开更多
基金Sasakawa Scientific Foundation of Japan, No.20-238 National Basic Research Program of China （973 Program）, No.2006CB403200+1 种基金 National Natural Science Foundation of China, No.40261002 No.40561006
文摘Based on four phases of TM images acquired in 1990, 1995, 2000 and 2005, this paper took Kitakyushu in Japan as a case study to analyze spatial change of land use landscape and corresponding effects on environmental issues guided by landscape ecology theory in virtue of combining technology of Remote Sensing with GIS. Firstly, land use types were divided into 6 classes （farmland, mountain, forestland, water body, urban land and unused land） according to national classification standard of land use, comprehensible ability of TM image and purpose of this study. Secondly, following the theory of landscape ecology analysis, 11 typical landscape indices were abstracted to evaluate the environmental effects and spatial feature changes of land use. Research results indicated that land use has grown more and more diversified and unbalanced, human activities have disturbed the landscape more seriously. Finally, transfer matrix of Markov was applied to forecast change process of land use in the future different periods, and then potential land use changes were also simulated from 2010 to 2050. Results showed that conversion tendency for all types of land use in Kitakyushu into urban construction land were enhanced. The study was anticipated to help local authorities better understand and address a complex land use system, and develop improved land use management strategies that could better balance urban expansion and ecological conservation.
文摘Terpenoids are the largest and most diverse class of plant-specialized metabolites, which function in diverse physiological processes during plant development. In the biosynthesis of plant terpenoids, short-chain prenyltransferases （SC-PTs）, together with terpene synthases （TPSs）, play critical roles in determining terpenoid diversity. SC-PTs biosynthesize prenyl pyrophosphates with different chain lengths, and these compounds are the direct precursors of terpenoids. Arabidopsis thaliana possesses a subgroup of SC-PTs whose functions are not clearly known. In this study, we focus on 10 geranylgeranyl pyro- phosphate synthase-like [GGPPSL] proteins, which are commonly thought to produce GGPP [C20]. We found that a subset of members of the Arabidopsis GGPPSL gene family have undergone neo- functionalization： GGPPSL6, 7, 9, and 10 mainly have geranylfarnesyl pyrophosphate synthase activity （C25; renamed AtGFPPS1, 2, 3, and 4）, and GGPPSL8 produces even longer chain prenyl pyrophosphate （〉C30; renamed polyprenyl pyrophosphate synthase 2, AtPPPS2）. By solving the crystal structures of AtGFPPS2, AtPPPS2, and AtGGPPS11, we reveal the product chain-length determination mechanism of SC-PTs and interpret it as a ＂three floors＂ model. Using this model, we identified a novel GFPPS clade distributed in Brassicaceae plants and found that the GFPPS gene typically occurs in tandem with a gene encoding a TPS, forming a GFPPS-TPS gene cluster.
基金supported by the National Natural Science Foundation of China(NSFC Nos.51932009,51929201,51672265,51672266,51750110511,51672257,52072349 and 51672259)Science and Technology Cooperation Project between Chinese and Australian Governments(2017YFE0132300)+1 种基金the Key Research Programme of Frontier Sciences,CAS(Grant No.YZDY-SSW-JSC018)Jiangmen Innovative Research Team Programme(2017)and Major Programme of Basic Research and Applied Research of Guangdong Province(2017KZDXM083).
文摘Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high efficiency,excellent thermal stability and high colour purity is still a challenge.In this work,unique non-concentration quenching in solid-solution Cs_(3)Gd_(1-x)Ge_(3)O_(9):xEu^(3+)(CGGO:xEu^(3+))(x=0.1-1.0)phosphors is successfully developed to achieve a highly efficient red-emitting Cs_(3)EuGe_(3)0_(9)(CEGO)phosphor.Under the optimal 464 nm blue light excitation,CEGO shows a strong red emission at 611 nm with a high colour purity of 95.07%and a high internal quantum efficiency of 94%.Impressively,this red-emitting CEGO phosphor exhibits a better thermal stability at higher temperatures(175-250℃,>90%)than typical red K2SiF6:Mn^(4+)and Y203:Eu^(3+)phosphors,and has a remarkable volumetric negative thermal expansion(coefficient of thermal expansion,a=—5.06×10^(-5)/℃,25-250℃).By employing this red CEGO phosphor,a fabricated pc-WLED emits warm white light with colour coordinates(0.364,0.383),a high colour rendering index(CRI=89.7),and a low colour coordinate temperature(CCT=4508 K).These results indicate that this highly efficient red-emitting phosphor has great potential as a red component for pc-WLEDs,opening a new perspective for developing new phosphor materials.
基金funded by the State Key Basic Research Program of China(No.2011CB201201)the National Key TechnologyR&D Program(No.2008BAB36B07)the National Natural Science Foundation of China(Nos.51134018 and 50674092)
文摘Non-pillar mining,top-coal caving and protected coal seam mining are the most popular mining methods in coal exploitation,and the different mining layouts will change the stress state and failure mechanism of coal in front of the working face.In this paper,mining-induced mechanical behaviors under three mining layouts have been simulated in the laboratory to investigate the effects of mining layouts on the deformation and strength of coal.Furthermore,the coal failure mechanism under different mining layouts is analyzed microscopically.The experimental results indicate that the stage characteristics of the coal deformation are obvious.Under the serial action of non-pillar mining,top-coal caving and protected coal seam mining layouts,the values of radial deformation,volume strain and Poisson's ratio increase,while the peak strength and deformation modulus decrease at the same buried depth,and the peak strength under non-pillar mining,top-coal caving and protected coal seam mining is about 3.0,2.5 and 2.0 times of the initial confining pressure,respectively.The results also indicate that the trend of the coal deformation decreases with the increase of the buried depth under the same mining layout,while the strength and deformation modulus increase,and the failure mechanism under three mining layouts is dominated with shear/tensile failure.
文摘Dear Editor,Monoterpenes, together with sesquiterpenes, play varying roles in plant interactions with the environment depending on the organs in which they are produced; these compounds likely function to attract pollinators when they are present in flowers and can protect plants against herbivores or microbes when produced in leaves or in roots. It is well known that geranyl diphosphate （GPP）, the common precursor of monoterpenes, is biosynthesized by geranyl diphosphate synthase （GPPS）. To date, two types of GPPS （EC 2.5.1.1） have been reported from plants： homomeric GPPS and heteromeric GPPS. Heteromeric GPPS is composed of one inactive small subunit （SSU; SSUs can be divided into two types： SSU I and SSU II） and one large subunit （LSU） （Burke et al., 1999; Tholl et al., 2004; Wang and Dixon, 2009）. In the Arabidopsis genome, there are 12 GGPPS paralogs and one homomeric GPPS gene （At2g34630） （Bouvier et al., 2000; Lange and Ghassemian, 2003; Beck et al., 2013）. A previous in vitro study characterized a heteromeric G（G）PS composed of GGPPS12 （also known as AtSSU, encoded by At4g38460 and belonging to the type II SSU type） and GGPPS11 （also known as AtLSU, encoded by At4g36810） （Wang and Dixon, 2009）. However, there is controversy as to which type of GPPS is involved in monoterpene biosynthesis in Arabidopsis. This controversy stems from the fact that both homomeric and heteromeric GPPS enzyme complexes catalyze the condensation of dimethylallyl pyrophosphate （DMAPP） and isopentenyl pyrophosphate （IPP） to form GPP when assayed in vitro （Bouvier et al., 2000; Wang and Dixon, 2009）. In the study reported here, we comprehensively analyzed transgenic GGPPS12, GGPPS11, and GPPS Arabidopsis plants and provide solid genetic evidence to support the supposition that heteromeric G（G）PPS, and not homomeric GPPS, is involved in monoterpene biosynthesis, at least in the flowers of Arabidopsis.
基金supported by the National Natural Science Foundation of China (Key Project) (60535020 and 50805076)National High-Tech Research & Development Program of China (2007AA04Z201)+1 种基金Natural Science Foundation of Jiangsu Province (BK2007202)Foundation of State Key Laboratory of Solid Lubrication
文摘Gecko's excellent adhesion ability is thought to derive from van der Waals force generated between the millions of keratinous hairs/setae and the contact surface.Fabricating highly gecko-inspired foot-hair becomes one of the key technologies to realize the three-dimensional-obstacle-free motion of robot.Researchers have fabricated various gecko-like foot-hair arrays which have leaning,large end,and hierarchical structures.Those significant works are summarized and suggestions for future work are proposed in this paper.
基金supported by the State Key Basic Research Program of China(No.2011CB201201)the National Natural Science Foundation of China(Nos.11172318 and 51134018)the Program of International S&T Cooperation of China(No.2010DFA64560)
文摘The exploitation of coal bed methane or coal gas is one of the most effective solutions of the problem of coal gas hazard.A better understanding of gas flow in mining-induced cracks plays an important role in comprehensive development and utilization of coal gas as well as prevention of coal gas hazard.This paper presents a case study of gas flow in mining-induced crack network regarding the situation of low permeability of coal seam.A two-dimensional physical model is constructed on the basis of geological background of mining face No.1122(1) in coal seam No.11-2,Zhangji Coal Mine,Huainan Mining Group Corporation.The mining-induced stress and cracks in overburden rocks are obtained by simulating an extraction in physical model.An evolution of mining-induced cracks in the process of advancing of coal mining face is characterized and three typical crack networks are taken from digital photos by means of image analysis.Moreover,the numerical software named COMSOL Multiphysics is employed to simulate the process of gas flow in three representative crack networks.Isograms of gas pressure at various times in mining-induced crack networks are plotted,suggesting a shape and dimension of gas accumulation area.
文摘This paper aims to conduct a comprehensive review of rural solid waste （RSW） in terms of character- istics, management and legislation. Survey results show that RSW generation rates range from 0.25 to 2.1 kg · （capita.d）-1 in different rural villages across regions of China. Total RSW generation has been increasing, which is far higher than official data in 2014. RSW are dominated by food residue and coal ash/cinder/dust （at approximately 70%）. Most of RSW are still discarded randomly without any treatment in China. Scattered RSW generation sources, imperfect legislation system, poor infrastructure on treat- ment and disposal are identified as the biggest challenge for RSW management currently in China. To improve RSW management, increasing financial resources, estab- lishing sorting collection and transportation network, promoting sorting collection and recycling, improving treatment technology are proposed as the possible solution.
基金the National Natural Science Foundation of China(Grant Nos.81530018,31371474,81370811,31570878 and 81300315).
文摘Macrophages play critical roles in renal fibrosis.However,macrophages exhibit ontogenic and functional heterogeneities,and which population of macrophages contributes to renal fibrosis and the underlying mechanisms remain unclear.In this study,we genetically targeted Notch signaling by disrupting the transcription factor recombination signal binding protein-JK(RBP-J),to reveal its role in regulation of macrophages during the unilateral ureteral obstruction(UUO)-induced murine renal fibrosis.Myeloid-specific disruption of RBP-J attenuated renal fibrosis with reduced extracellular matrix deposition and myofibroblast activation,as well as attenuated epithelial-mesenchymal transition,likely owing to the reduced expression of TGF-β.Mean while,RBP-J deletion significantly hampered macrophage infiltration and activation in fibrotic kidney,although their proliferation appeared unaltered.By using macrophage clearance experiment,we found that kidney resident macrophages made negligible contribution,but bone marrow(BM)-derived macrophages played a major role in renal fibrogenesis.Further mechanistic analyses showed that Notch blockade reduced monocyte emigration from BM by down-regulating CCR2 expression.Finally,we found that myeloid-specific Notch activation aggravated renal fibrosis,which was mediated by CCR2^+macrophages infiltration.In summary,our data have unveiled that myeloid-specific targeting of Notch could ameliorate renal fibrosis by regulating BM-derived macrophages recruitment and activation,providing a novel strategy for intervention of this disease.
基金Supported by the National Natural Key Science Foundation of China (Grant No. 60535020)National Natural Science Foundation of China (Grant Nos. 50705043 and 50805076)Natural Science Foundation of Jiangsu Province (Grant No. 2007202)
文摘This paper reports a new technique to fabricate an ion-exchange polymer-metal composite (IPMC) actuator. This technique is based on a hybrid organic-inorganic composite membrane. In the fabrication course, silica oxide particles, prepared from hydrolysis of tetraethyl orthosilicate in situ with sol-gel reaction, co-crystallize with perfluorosulfonate acid (PFSA) ionomer. Attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) analyses demonstrate that a highly water-saving hybrid membrane is formed. Measurements of mechanical properties reveal that elastic modulus and hardness of the hybrid membrane are about 2 times compared to a commercial PFSA membrane. Scanning electron microscopy (SEM) results show that the hybrid membrane has a high porosity. Inside the membrane pores, there exists a great quantity of micro scale channels in the range of 100―300 nm. After fabrication of IPMC actuator, an electric current sensor, a force sensor, and a high speed camera are assembled and used to evaluate IPMC performance. It is shown that, compared to an IPMC actuator made from a commercial membrane, the electromechanical performance of the new actuator increases 6―8 times; when it is actuated in air, its stable non-water working time is prolonged for 6―7 times.
基金China Postdoctoral Science Foundation,Grant/Award Number:2019M660410National Key R&D Project from Minister of Science and Technology,China,Grant/Award Numbers:2016YFA0202703,2016YFC1102202+4 种基金National Natural Science Foundation of China,Grant/Award Numbers:11421202,21801019,61875015,81971770National Postdoctoral Program for Innovative Talent,Grant/Award Number:BX20190026Natural Science Foundation of Beijing Municipality,Grant/Award Number:7204275The 111 Project,Grant/Award Number:B13003National Youth Talent Support Program。
文摘Self-powerability is a new trend in the development of portable devices.Harvesting biomechanical energy to power personal information electronics is of great significance.In this work,we report a wearable noncontact freerotating hybrid nanogenerator(WRG),which is constituted by a triboelectric nanogenerator and an electromagnetic generator.A continuous output over 2 seconds can be achieved during one instantaneous incentive by external force,which is improved by two orders of magnitude compared to other wearable nanogenerators due to its unique mechanical energy storage design.The WRG can be integrated into shoes to generate an output energy of 14.68 mJ in each stepping,which meets the power requirements of most personal information electronics.The wireless sensor,GPS,and smartphone can be powered by the WRG continuously.The WRG is expected to be applied in self-powered information electronics extensively in the future.
基金Supported by the National Key Research and Development Program of China(2017YFC1501502)Open Fund of Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites of National Satellite Meteorological CenterNational Natural Science Foundation of China(41405004 and 41875001)。
文摘Using lightning observations from the Fengyun-4A Lightning Mapping Imager(FY-4A LMI),best-track data from the Shanghai Typhoon Institute,bright temperature(TBB)data from Himawari-8 satellite,and composite reflectivity(CR)data from the South China radar network,we investigate the spatiotemporal distribution of lightning activity and convective evolution during the landfall of Super Typhoon Mangkhut,the strongest landing typhoon in China in2018.Three stages of active total lightning are observed,and differences of lightning characteristics between the inner core and the outer rainbands are present.The onset of inner-core lightning outbreak is about 4 h ahead of the maximum intensity of the storm,providing indicative information on the change of typhoon intensity.Lightning rates in the outer rainbands increase rapidly 12 h before the landfall,and lightning activity is mainly confined in the outer rainbands after the landfall.A good correlation in hourly variation is shown between lightning rates from the LMI and TBBs from the satellite.The averaged TBB within the inner core reaches its minimum(–80℃)when the innercore lightning outbreak occurs,indicating the occurrence and enhancement of deep convection there.Lightning locations observed by the LMI has a good spatial correspondence with regions of low TBBs and high CRs,revealing the monitoring capability of the LMI to lightning activity and deep convection in landing typhoons.Comparisons between the World Wide Lightning Location Network(WWLLN)and the LMI reveal that the spatial distribution,temporal evolution,and radial pattern of lightning activity in Mangkhut observed by the two systems are consistent.Furthermore,due to the detection capability of total lightning,the LMI has advantages in revealing the higher ratio of intra-cloud lightning within the inner core in typhoon.The continuous and real-time observation ofFY-4ALMI provides an unprecedented platform for monitoring total lightning and deep convection in landing typhoons in China,which will promote the ge
基金supported by the grants from National Natural Science Foundation of China (82073915, 91849135, 81673485, 81773719, 81973312 and 81971306)National Key Research and Development Project (2018YFA0108301, China)+2 种基金Shanghai Science and Technology Commission Experimental Animal Grants (21XD1424900, 19140904700, 19140904900 and 21S11901200, China)Shanghai Shuguang Program (19SG32, China)Shanghai “Rising Stars of Medical Talent” Youth Development ProgramYouth Medical Talents-Clinical Pharmacist Program [SHWRS(2020)_087, China]
文摘Metabolic-associated fatty liver disease(MAFLD),which is previously known as non-alcoholic fatty liver disease(NAFLD),represents a major health concern worldwide with limited therapy.Here,we provide evidence that ferroptosis,a novel form of regulated cell death characterized by iron-driven lipid peroxidation,was comprehensively activated in liver tissues from MAFLD patients.The canonical-GPX4(cGPX4),which is the most important negative controller of ferroptosis,is downregulated at protein but not mRNA level.Interestingly,a non-canonical GPX4 transcript-variant is induced(inducible-GPX4,iGPX4)in MAFLD condition.The high fat-fructose/sucrose diet(HFFD)and methionine/choline-deficient diet(MCD)-induced MAFLD pathologies,including hepatocellular ballooning,steatohepatitis andfibrosis,were attenuated and aggravated,respectively,in cGPX4-and iGPX4-knockin mice.cGPX4 and iGPX4 isoforms also displayed opposing effects on oxidative stress and ferroptosis in hepatocytes.Knockdown of iGPX4 by siRNA alleviated lipid stress,ferroptosis and cell injury.Mechanistically,the triggered iGPX4 interacts with cGPX4 to facilitate the transformation of cGPX4 from enzymatic-active monomer to enzymatic-inactive oligomers upon lipid stress,and thus promotes ferroptosis.Co-immunoprecipitation and nano LC–MS/MS analyses confirmed the interaction between iGPX4 and cGPX4.Our results reveal a detrimental role of non-canonical GPX4 isoform in ferroptosis,and indicate selectively targeting iGPX4 may be a promising therapeutic strategy for MAFLD.
基金funded by the NationalNatural Science Foundation of China (Grant No. 41772008) StateKey Laboratory of Palaeobiology and Stratigraphy+1 种基金Nanjing Instituteof Geology and PalaeontologyChinese Academy of Sciences (GrantNo. 173127)
文摘The newly discovered large(350 m^2) Yantan dinosaur tracksite, in the Lower Jurassic Ziliujing Formation of Guizhou Province, China, reveals at least 250 footprints of which ~97 can be resolved into trackways of sauropodomorphs. All the trackways are sub parallel likely indicating gregarious behavior. One theropod track(cf. Grallator) was recorded. The sauropodomorph tracks predominantly represent quadrupedal progression(Morphotype A), and footprint morphology is similar to the ichnospecies Liujianpusshunan, characterized by outward pes rotation. Three trackways indicate bipedal progression, and two of these(Morphotype B) indicate inward pes rotation, accompanied by elongate pes digit scratch marks. For the latter phenomenon three possible scenarios are discussed:(1) significant rotation changes accompanying changes in gait,(2) swimming behavior,(3) formation of undertracks.Sedimentological evidence indicates the tracks were made on a linguloid rippled, muddy, immature sandstone substrate characterized by significant differences in substrate consistency across the trackbearing surface. Microbially induced sedimentary structures(MISS) characterized by distinctive wrinkle marks indicate a stressed, probably semi-arid, paleoenvironment that was not conducive to habitation by invertebrate organisms. This is consistent with other evidence that Lower Jurassic sauropodomorph tracks are often associated with semi-arid paleoenvironments.
基金support of the National Natural Science Foundation of China(51604275)the Key Laboratory of Urban Under Ground Engineering of Ministry of Education(TUE2018-01)+1 种基金Yue Qi Young Scholar Project of China University of Mining&Technology,Beijingthe Fundamental Research Funds for the Central Universities(2016QL02).
文摘Natural fracture data from one of the Carboniferous shale masses in the eastern Qaidam Basin were used to establish a stochastic model of a discrete fracture network and to perform discrete element simulation research on the size efect and mechanical parameters of shale.Analytical solutions of fctitious joints in transversely isotropic media were derived,which made it possible for the proposed numerical model to simulate the bedding and natural fractures in shale masses.The results indicate that there are two main factors infuencing the representative elementary volume(REV)size of a shale mass.The frst and most decisive factor is the presence of natural fractures in the block itself.The second is the anisotropy ratio:the greater the anisotropy is,the larger the REV.The bedding angle has little infuence on the REV size,whereas it has a certain infuence on the mechanical parameters of the rock mass.When the bedding angle approaches the average orientation of the natural fractures,the mechanical parameters of the shale blocks decrease greatly.The REV representing the mechanical properties of the Carboniferous shale masses in the eastern Qaidam Basin were comprehensively identifed by considering the infuence of bedding and natural fractures.When the numerical model size is larger than the REV,the fractured rock mass discontinuities can be transformed into equivalent continuities,which provides a method for simulating shale with natural fractures and bedding to analyze the stability of a borehole wall in shale.
基金financially supported by the National Natural Science Foundation of China(NSFC Nos.51720105015,51932009,51929201,52072349)the Projects for Science and Technology Development Plan of Jilin Province(20210402046GH)the Natural Science Foundation of Zhejiang Province(LR22E020004).
文摘Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,next-generation Cr^(3+)-free NIR-emitting phosphors with high efficiency and tunable optical properties are highly desired to enrich the types of NIR luminescent materials for different application fields.Here,we report the Fe^(3+)-activated Sr2−yCay(InSb)1−zSn_(2)zO_(6)phosphors that exhibit unprecedented long-wavelength NIR emission.The overall emission tuning from 885 to 1005 nm with broadened full-width at half maximum from 108 to 146 nm was realized through a crystallographic site engineering strategy.The NIR emission was significantly enhanced after complete Ca^(2+)incorporation owing to the substitution-induced lower symmetry of the Fe^(3+)sites.The Ca_(2)InSbO_(6):Fe^(3+)phosphor peaking at 935 nm showed an ultra-high internal quantum efficiency of 87%.The as-synthesized emission-tunable phosphors demonstrated great potential for NIR spectroscopy detection.This work initiates the development of efficient Fe^(3+)-activated broadband NIR-emitting phosphors and opens up a new avenue for designing NIR-emitting phosphor materials.
基金the National High Technology Research and Development Program of China (Grant No.2001AA213091) Natural Science Foundation of Hebei Prov-ince (Grant No.C2006001032)
文摘In somatic cell nuclear transfer (SCNT) technologies,the donor cell’s nuclei need to be epigenetically reprogrammed for embryonic development. The incomplete reprogramming of donor cell nuclei has been implicated as a primary reason for the low efficiency of SCNT. DNA methylation is a major epige-netic modification of the genome that regulates crucial aspects of genome function,including estab-lishment of genomic imprinting. In order to make sure whether the DNA methylation reprogramming is efficient in SCNT animals,we analyzed the DNA methylation status of two imprinting genes,H19 and Xist,in lungs of deceased SCNT bovines that died within 48 h of birth using bisulfite sequencing analysis. Our findings demonstrated that cloned bovines showed significantly lower DNA methylation of H19 than controls (P<0.05),and three tested CpGs sites (1,2,3) exhibited unmethylation in one cloned bovine (9C3); however,Xist showed similar DNA methylation levels between clones and con-trols,and both showed hypermethylation (96.11% and 86.67%).
基金This work was financially supported by the National Science and Technology Major Project(2022YFB3503800)the National Natural Science Foundation of China(NSFC Nos.51932009,51929201,52072349,52172166,12374386,12374388,12304461,U2005212)+1 种基金the Natural Science Foundation of Zhejiang Province(LR22E020004)the Project funded by China Postdoctoral Science Foundation(2022TQ0365,2023M733436).
文摘Achievement of high photoluminescence quantum efficiency and thermal stability is challenging for near-infrared(NIR)-emitting phosphors.Here,we designed a“kill two birds with one stone”strategy to simultaneously improve quantum efficiency and thermal stability of the NIR-emitting Ca_(3)Y_(2-2x)(ZnZr)_(x)Ge_(3)O_(12):Cr garnet system by chemical unit cosubstitution,and revealed universal structure-property relationship and the luminescence optimization mechanism.The cosubstitution of[Zn^(2+)-Zr^(4+)]for[Y^(3+)-Y^(3+)]played a critical role as reductant to promote the valence transformation from Cr^(4+)to Cr^(3+),resulting from the reconstruction of octahedral sites for Cr^(3+).The introduction of[Zn^(2+)-Zr^(4+)]unit also contributed to a rigid crystal structure.These two aspects together realized the high internal quantum efficiency of 96%and excellent thermal stability of 89%@423 K.Moreover,information encryption with“burning after reading”was achieved based on different chemical resistance of the phosphors to acid.The developed NIR-emitting phosphor-converted light-emitting diode demonstrated promising applications in bio-tissue imaging and night vision.This work provides a new perspective for developing high-performance NIR-emitting phosphor materials.
基金This work was supported by the National Natural Science Foundation of China(31972362,32001993)the Project of the Shandong Natural Science Foundation(ZR2020QC143)the Breeding Plan of the Shandong Provincial Qingchuang Research Team(2019).
文摘Color is an important trait for horticultural crops.Carotenoids are one of the main pigments for coloration and have important implications for photosynthesis in plants and benefits for human health.Here,we identified an APETALA2(AP2)/ETHYLENE RESPONSE FACTOR(ERF)transcription factor named MdAP2-34 in apple(Malus domestica Borkh.).MdAP2-34 expression exhibited a close correlation with carotenoid content in‘Benin Shogun’and‘Yanfu 3’fruit flesh.MdAP2-34 promotes carotenoid accumulation in MdAP2-34-OVX transgenic apple calli and fruits by participating in the carotenoid biosynthesis pathway.The major carotenoid contents of phytoene andβ-carotene were much higher in overexpressing MdAP2-34 transgenic calli and fruit skin,yet the predominant compound of lutein showed no obvious difference,indicating that MdAP2-34 regulates phytoene andβ-carotene accumulation but not lutein.MdPSY2-1(phytoene synthase 2)is a major gene in the carotenoid biosynthesis pathway in apple fruit,and the MdPSY2-1 gene is directly bound and transcriptionally activated by MdAP2-34.In addition,overexpressing MdPSY2-1 in apple calli mainly increases phytoene and total carotenoid contents.Our findings will advance and extend our understanding of the complex molecular mechanisms of carotenoid biosynthesis in apple,and this research is valuable for accelerating the apple breeding process.
基金the National Science Foundation,USA (IOS-1048216 and IOS-1340001)the National Natural Science Foundation of China (31571679,31501292,31871554)+1 种基金the Major Science and Technology Project of Henan Province (141100110600)the Support Plan of Science and Technology Innovation Team in Universities of Henan Province (171RTSTHN015),and the Key Scientific Research Project in Universities of Henan Province (16A210009).G.T.is also supported by the Guangdong Innovation Research Team Fund (2014ZT058078)and the 111 Project (D16014)to Henan University.S.T.was supported by a post-doctoral fellowship from Henan Agricultural University.F.M.was a visiting scholar supported by the China Scholarship Council (CSC).T.P.,Z.Z.,L.S.,and L.T.were visiting PhD students supported by scholarships from Henan Agricultural University.
文摘microRNAs (miRNAs)are endogenous small non-coding RNAs that bind to mRNAs and target them for cleavage and/or translational repression,leading to gene silencing.We previously developed short tandem target mimic (STTM)technology to deactivate endogenous miRNAs in Arabidopsis.Here,we created hundreds of STTMs that target both conserved and species-specific miRNAs in Arabidopsis,tomato,rice,and maize,providing a resource for the functional interrogation of miRNAs.We not only revealed the functions of several miRNAs in plant development,but also demonstrated that tissue-specific inactivation of a few miRNAs in rice leads to an increase in grain size without adversely affecting overall plant growth and development.RNA-seq and small RNAseq analyses of STTM156/157 and STTM165/166 transgenic plants revealed the roles of these miRNAs in plant hormone biosynthesis and activation,secondary metabolism,and ion-channel activity-associated electrophysiology,demonstrating that STTM technology is an effective approach for studying miRNA functions.To facilitate the study and application of STTM transgenic plants and to provide a useful platform for storing and sharing of information about miRNA-regulated gene networks,we have established an online Genome Browser (https://blossom.ffr.mtu.edu/designindex2.php) to display the transcriptomic and miRNAomic changes in STTMinduced miRNA knockdown plants.
