Fast mapping of a chlorophyll b synthesis-deficiency gene in barley(Hordeum vulgare L.) via bulked-segregant analysis with reduced-representation sequencing

Bulked-segregant analysis coupled with next-generation sequencing(BSA-seq) has emerged as an efficient tool for genetic mapping of single genes or major quantitative trait loci controlling(agronomic) traits of interest. However, such a mapping-by-sequencing approach usually relies on deep sequencing and advanced statistical methods. Application of BSA-Seq based on construction of reduced-representation libraries and allele frequency analysis permitted anchoring the barley pale-green(pg) gene on chromosome 3 HL. With further marker-assisted validation, pg was mapped to a 3.9 Mb physical-map interval. In the pg mutant a complete deletion of chlorophyllide a oxygenase(HvCAO) gene was identified.Because the product of this gene converts Chl a to Chl b, the pg mutant is deficient in Chl b.An independent Chl b-less mutant line M4437_2 carried a nonsynonymous substitution(F263 L) in the C domain of HvCAO. The study demonstrates an optimized pooling strategy for fast mapping of agronomically important genes using a segregating population.

A linearly-independent higher-order extended numerical manifold method and its application to multiple crack growth simulation

The numerical manifold method(NMM)can be viewed as an inherent continuous-discontinuous numerical method,which is based on two cover systems including mathematical and physical covers.Higher-order NMM that adopts higher-order polynomials as its local approximations generally shows higher precision than zero-order NMM whose local approximations are constants.Therefore,higherorder NMM will be an excellent choice for crack propagation problem which requires higher stress accuracy.In addition,it is crucial to improve the stress accuracy around the crack tip for determining the direction of crack growth according to the maximum circumferential stress criterion in fracture mechanics.Thus,some other enriched local approximations are introduced to model the stress singularity at the crack tip.Generally,higher-order NMM,especially first-order NMM wherein local approximations are first-order polynomials,has the linear dependence problems as other partition of unit(PUM)based numerical methods does.To overcome this problem,an extended NMM is developed based on a new local approximation derived from the triangular plate element in the finite element method(FEM),which has no linear dependence issue.Meanwhile,the stresses at the nodes of mathematical mesh(the nodal stresses in FEM)are continuous and the degrees of freedom defined on the physical patches are physically meaningful.Next,the extended NMM is employed to solve multiple crack propagation problems.It shows that the fracture mechanics requirement and mechanical equilibrium can be satisfied by the trial-and-error method and the adjustment of the load multiplier in the process of crack propagation.Four numerical examples are illustrated to verify the feasibility of the proposed extended NMM.The numerical examples indicate that the crack growths simulated by the extended NMM are in good accordance with the reference solutions.Thus the effectiveness and correctness of the developed NMM have been validated.

Omnidirectional and compact Tamm phonon-polaritons enhanced mid-infrared absorber

Narrow band mid-infrared(MIR)absorption is highly desired in thermal emitter and sensing applications.We theoretically demonstrate that the perfect absorption at infrared frequencies can be achieved and controlled around the surface phonon resonance frequency of silicon carbide(SiC).The photonic heterostructure is composed of a distributed Bragg reflector(DBR)/germanium(Ge)cavity/SiC on top of a Ge substrate.Full-wave simulation results illustrate that the Tamm phonon-polaritons electric field can locally concentrate between the Ge cavity and the SiC film,contributed to the improved light-phonon interactions with an enhancement of light absorption.The structure has planar geometry and does not require nano-patterning to achieve perfect absorption of both polarizations of the incident light in a wide range of incident angles.Their absorption lines are tunable via engineering of the photon band-structure of the dielectric photonic nanostructures to achieve reversal of the geometrical phase across the interface with the plasmonic absorber.

Nanoadjuvant-triggered STING activation evokes systemic immunotherapy for repetitive implant-related infections

Repetitive implant-related infections(IRIs)are devastating complications in orthopedic surgery,threatening implant survival and even the life of the host.Biofilms conceal bacterial-associated antigens(BAAs)and result in a"cold tumor"-like immune silent microenvironment,allowing the persistence of IRIs.To address this challenge,an iron-based covalent organic framed nanoadjuvant doped with curcumin and platinum(CFCP)was designed in the present study to achieve efficient treatment of IRIs by inducing a systemic immune response.Specifically,enhanced sonodynamic therapy(SDT)from CFCP combined with iron ion metabolic interference increased the release of bacterial-associated double-stranded DNA(dsDNA).Immunogenic dsDNA promoted dendritic cell(DC)maturation through activation of the stimulator of interferon gene(STING)and amplified the immune stimulation of neutrophils via interferon-β(IFN-β).At the same time,enhanced BAA presentation aroused humoral immunity in B and T cells,creating long-term resistance to repetitive infections.Encouragingly,CFCP served as neoadjuvant immunotherapy for sustained antibacterial protection on implants and was expected to guide clinical IRI treatment and relapse prevention.

Ultrathin curved PdNiRu nanosheets as bifunctional catalysts for oxygen reduction and ethylene glycol oxidation

Pd-based metallic nanosheets with advanced physicochemical properties have been widely prepared and employed in various electrocatalytic reactions.However,few concerns were focused on their multiple performances in different electrocatalysis.Here,highly curved and ultrathin PdNiRu nanosheets(NSs)are developed by facile wet-chemistry strategy and exhibit excellent electrocatalytic performance toward both oxygen reduction reaction(ORR)and ethylene glycol oxidation reaction(EGOR).Owing to the synergistically structural(e.g.,ultrathin,curved,defects/steps-rich)and compositional(ternary alloy)advantages,PdNiRu NSs exhibited enhanced ORR and EGOR specific/mass activities and better stability/durability than control electrocatalysts.The specific activity(5.52 mA·cm^(−2))and mass activity(1.13 A·mg_(Pd)^(−1))of the PdNiRu NSs in ORR are 4.8 and 3.4 times as the ones of commercial Pt/C,respectively.The mass activity of PdNiRu NSs(3.86 A·mg_(Pd)^(−1))in EGOR is 2.6 times as commercial Pd/C(1.51 A·mg_(Pd)^(−1)).This study is helpful for the development of desired electrocatalysts with multi-functional application in practical fuel cells.

Natural variations of HvSRN1 modulate the spike rachis node number in barley

Grain number,one of the major determinants of yield in Triticeae crops,is largely determined by spikelet number and spike rachis node number(SRN).Here,we identified three quantitative trait loci(QTLs)for SRN using 145 recombinant inbred lines derived from a barley R90/1815D cross.qSRN1,the major-effect QTL,was mapped to chromosome 2H and explained up to 38.77%of SRN variation.Map-based cloning revealed that qSRN1 encodes the RAWUL domain-containing protein HvSRN1.Further analysis revealed that two key SNPs in the HvSRN1 promoter region(-2 kb upstream of the transcription start site)affect the transcript level of HvSRN1 and contribute to variation in SRN.Similar to its orthologous proteins OsLAX2 and ZmBA2,HvSRN1 showed protein–protein interactions with HvLAX1,suggesting that the LAX2–LAX1 model for spike morphology regulation may be conserved in Poaceae crops.CRISPR-Cas9-induced HvSRN1 mutants showed reduced SRN but increased grain size and weight,demonstrating a trade-off effect.Our results shed light on the role of HvSRN1 variation in regulating the balance between grain number and weight in barley.

Dressing Mechanism and Evaluations of Grinding Performance with Porous cBN Grinding Wheels

Cubic boron nitride(cBN)grinding wheels play a pivotal role in precision machining,serving as indispensable tools for achieving exceptional surface quality.Ensuring the sharpness of cBN grains and optimizing the grinding wheel’s chip storage capacity are critical factors.This paper presents a study on the metal-bonded segments and single cBN grain samples using the vacuum sintering method.It investigates the impact of blasting parameters-specifically silicon carbide(SiC)abrasive size,blasting distance,and blasting time-on the erosive wear characteristics of both the metal bond and abrasive.The findings indicate that the abrasive size and blasting distance significantly affect the erosive wear performance of the metal bond.Following a comprehensive analysis of the material removal rate of the metal bond and the erosive wear condition of cBN grains,optimal parameters for the working layer are determined:a blasting distance of 60 mm,a blasting time of 15 s,and SiC particle size of 100#.Furthermore,an advanced simulation model investigates the dressing process of abrasive blasting,revealing that the metal bond effectively inhibits crack propagation within cBN abrasive grains,thereby enhancing fracture toughness and impact resistance.Additionally,a comparative analysis is conducted between the grinding performance of porous cBN grinding wheels and vitrified cBN grinding wheels.The results demonstrate that using porous cBN grinding wheels significantly reduces grinding force,temperature,and chip adhesion,thereby enhancing the surface quality of the workpiece.

Self‐assembled monolayers for perovskite solar cells

In metal‐halide perovskite solar cells(PSCs),various carrier recombination losses occur at the interface between metal oxides(MOs)and perovskite(PVK)due to the imperfect lattice structure of the crystal surface.Additionally,the nonoptimal energy levels of MOs and PVK,as well as ion diffusion and chemical corrosion between the two materials,severely hinder carrier transport at the interface.Therefore,there is an urgent need to introduce multifunctional materials between MOs and PVK to mitigate interface defects,carrier transport limitations,chemical corrosion,and other related issues.In recent years,self‐assembled monolayers(SAMs)have emerged as essential organic interfacial materials for effectively bridging MOs and PVK,playing a pivotal role in enhancing cells’performance.Based on this,we provide a detailed overview of the origin and development of SAMs in PSCs and summarize the importance and potential of SAMs from various aspects,including their chemical structure,interface passivation,energy level tuning,and interface corrosion.We finally discuss the prospects of SAMs in terms of molecular structure,deposition methods,and their application in narrow‐band gap PSCs.With these insights,it is anticipated that SAMs will assist in realizing larger,highly efficient,stable,and cost‐effective PSCs,thereby enhancing the competitiveness of PSCs in the solar photovoltaics market.

Engineering porous architectures in multicomponent PdCuBP mesoporous nanospheres for electrocatalytic ethanol oxidation

Porous features of mesoporous metal nanocrystals are critically important for their applications in catalysis,sorption,and biomedicine and bioimaging.However,precisely engineering porous architectures of mesoporous metals is still highly challenging.Herein,we report a facile soft-templating strategy to precisely engineer porous architectures of multicomponent PdCuBP mesoporous nanospheres(MSs)by using the surfactants with different amphiphilic features.Three kinds of MSs with distinct porous architectures,including three-dimensional(3D)opened/interconnected dendritic mesopores(dMSs),one-dimensional(1D)cylindered mesopores(cMSs),and zero-dimensional(0D)spherical mesopores(sMSs),are prepared.This surfactant-templating method is generally extended to regulate elemental compositions of multicomponent MSs.The resultant Pd-based MSs have been evaluated as the electrocatalysts for ethanol oxidation reaction(EOR).Our results show that quaternary PdCuBP dMSs display remarkably high catalytic activity and better stability for electrocatalytic EOR,compared to those of multicomponent MSs with other porous architectures and less elemental compositions.Mechanism studies reveal that PdCuBP dMSs combine multiple structural and compositional advantages,which kinetically accelerate the electron/mass transfers and also improve the tolerances to poisoning intermediates.We believe that the porous architecture engineering in mesoporous metal electrocatalysts will present a new way to design highly efficient electrocatalysts with desired porous systems and explore their relations towards(electro)catalysis.

Ternary metal-metalloid-nonmetal alloy nanowires:a novel electrocatalyst for highly efficient ethanol oxidation electrocatalysis

We report rational design and syntheses of ternary noble metal-metalloid-nonmetal alloy nanowires(NWs)as a novel electrocatalyst for electrochemical ethanol oxidation reaction(EOR).This novel electrocatalyst is formed in an aqueous solution via anisotropic nucleation and growth of ternary PdBP alloy NWs along assembled cylinder template of Plurolic F127 on a nitrogen-functionalized graphene support(denoted as PdBP NWs@N-G).We find that uniformly alloying B and P intrinsically modulates the electronic states of Pd catalyst and also introduces new functions into the catalyst,while NW structure supported on the N-G exposes more electrocatalytic active sites and accelerates electron/mass transfers.Such add-in synergies of PdBP NWs@N-G kinetically facilitate the removal and/or further oxidation of CO-based poisoning intermediates,thus remarkably enhancing the electrocatalytic EOR performance.They exhibit a high mass activity of 4.15 A mgPd^-1 and superior cycling and chronoamperometric stability for electrocatalytic EOR,much better than previously reported monometallic Pd-based nanocatalysts.More interestingly,this design strategy can be easily extended to develop more sophisticated NWs catalysts with more compositions(for example quaternary PdCuBP NWs@N-G)that further tunes the electronic and bifuntional effects for various desired catalysis and electrocatalysis.

Single-Crystalline Mesoporous Palladium and Palladium-Copper Nanocubes for Highly Efficient Electrochemical CO_(2) Reduction

Mesoporous single crystals have unique potential in catalysis,but remain unexplored owing to the enormous synthetic challenge that they pose.Herein,we report a facile soft-template method to prepare palladium(Pd)and Pd alloy nanocubes with single-crystallinity and abundant mesoporosity.The successful formation of these exotic nanostructures essentially relies on the cointroduction of cetyltrimethylammonium chloride as the surfactant template and extra Cl^(−) ions as the facet-selective capping agent under well controlled experimental conditions.Thanks to their large surface areas and penetrating mesoporous channels,our products exhibit a great performance for electrochemical CO_(2) reduction.The best sample from alloying palladium with copper enables the efficient formate production with high selectivity(90∼100%)over a broad potential range,and great stability even under the working potential as cathodic as −0.5 V versus a reversible hydrogen electrode.These performance metrics are far superior to previous Pd-based materials,and underscore the structural advantages of our products.

Identification and functional characterization of the AGO1 ortholog in maize

Eukaryotic Argonaute proteins play primary roles in mi RNA and si RNA pathways that are essential for numerous developmental and biological processes. However, the functional roles of the four Zm AGO1 genes have not yet been characterized in maize（Zea mays L.）. In the present study, Zm AGO1 a was identified from four putative Zm AGO1 genes for further characterization. Complementation of the Arabidopsis ago1-27 mutant with Zm AGO1 a indicated that constitutive overexpression of Zm AGO1 a could restore the smaller rosette, serrated leaves, later flowering and maturation, lower seed set, and darker green leaves at late stages of the mutant to the wild-type phenotype. The expression profiles of Zm AGO1 a under five different abiotic stresses indicated that Zm AGO1 a shares expression patterns similar to those of Argonaute genes in rice, Arabidopsis, and wheat.Further, variation in Zm AGO1 a alleles among diverse maize germplasm that resulted in several amino acid changes revealed genetic diversity at this locus. The present data suggest that Zm AGO1 a might be an important AGO1 ortholog in maize. The results presented provide further insight into the function of ZmAGO1a.

A universal strategy for fast,scalable,and aqueous synthesis of multicomponent palladium alloy ultrathin nanowires

Noble metal alloy nanowires(NWs)with ultrathin diameters(2–3 nm)and precisely controllable elemental compositions have attracted dramatically growing attention for(electro)catalysis.Despites numerous achievements in past two decades,noble metal alloy NWs are mostly synthesized with the traditional oil-phase methods that suffer from some undesirable drawbacks.Here,we report a general strategy for fast,scalable,and aqueous synthesis of multicomponent Pd-based alloy ultrathin NWs with an average diameter of 2.6 nm,ranging from bimetallic PdM(PdFe,PdCo,PdNi,PdCu,PdZn,PdRu,PdRh,PdAg,PdCd,PdIr,PdPt,PdAu)and binary PdS/PdP NWs,to trimetallic PdM1M2 NWs(PdAuCu,PdCoNi,PdCuZn,PdCuNi,PdAgCu,PdAuCu,PdRuAg,PdAuRu,and PdPtAu),and to tetrametallic PdM1M2M3 NWs(PdAuAgCu,PdCoCuNi,PdAuCuNi,PdPtAuCu,and PdIrPtAu).The key to the success of this aqueous synthesis is the utilization of N2H4 as the extremely strong reducing agent that directs the synchronous reduction and anisotropic nucleation growth of multicomponent Pd alloy NWs along nanoconfined columnar phase assembled with amphiphilic dioctadecyldimethylammonium chloride.As-resultant Pd-based alloy ultrathin NWs exhibit multiple structural and compositional synergies,which remarkably optimize the removal of poisoning ethoxy intermediates and thus improve electrocatalytic performance towards ethanol oxidation reaction(EOR).Among them,tetrametallic PdAuCuNi alloy ultrathin NWs hold a high EOR activity of 5.14 A mg-1 Pd and a low activation energy of 13.1 kJ mol^-1,both of which are much better than its counterpart catalysts alloyed with less elements.This work represents an important advance in precise aqueous synthesis of multicomponent noble metal alloy ultrathin NWs as the high-performance electrocatalysts for various targeted applications.

Precise Synthesis of Hollow Mesoporous Palladium–Sulfur Alloy Nanoparticles for Selective Catalytic Hydrogenation

Hollow mesoporous metals have unique potential for catalysis,but their precise synthesis and further elaboration of their structure–performance relationships are still huge challenges.Herein,wereport a new synthetic strategy,named the Kirkendall effect in synergistic template(KEST),for the desired preparation of hollow mesoporous palladium–sulfur(h-mesoPdS)alloy nanoparticles.

Material removal mechanisms in ultrasonic vibration-assisted high-efficiency deep grindingγ-TiAl alloy

Gamma titanium-aluminum intermetallic compounds(γ-TiAl)have gained considerable attentions in the aerospace industry due to their exceptional thermal resilience and comprehensive attributes,making them a prime example of lightweight and advanced materials.To address the frequent occurrence of burns and severe tool deterioration during the process of high-efficiency deep grinding(HEDG)onγ-TiAl alloys,ultrasonic vibration-assisted high-efficiency deep grinding(UVHEDG)has been emerged.Results indicate that in UVHEDG,the grinding temperature is on average 15.4%lower than HEDG due to the employment of ultrasonic vibrations,enhancing coolant penetration into the grinding area and thus reducing heat generation.Besides,UVHEDG possesses superior performance in terms of grinding forces compared to HEDG.As the material removal volume(MRV)increases,the tangential grinding force(F_(t))and normal grinding force(F_(n))of UVHEDG increase but to a lesser extent than in HEDG,with an average reduction of16.25%and 14.7%,respectively.UVHEDG primarily experiences microfracture of grains,whereas HEDG undergoes large-scale wear later in the process due to increased grinding forces.The surface roughness(R_(a))characteristics of UVHEDG are superior,with the average value of R_(a)decreasing by 46.5%compared to HEDG as MRV increases.The surface morphology in UVHEDG exhibits enhanced smoothness and a shallower layer of plastic deformation.Grinding chips generated by UVHEDG show a more shear-like shape,with the applied influence of ultrasonic vibration on chip morphology,thereby impacting material removal behaviors.These aforementioned findings contribute to enhanced machining efficiency and product quality ofγ-TiAl alloys after employing ultrasonic vibrations into HEDG.