The KL system in wheat permits homoeologous crossing over between closely related chromosomes

The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characteristics of homoeologous pairing and recombination induced by phKL.In KL haploids,the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring(CS)haploids.There was a clear preference for A–D pairing and less frequent for A–B and B–D,reflecting the higher levels of affinity between genomes A and D in wheat.The characteristics of pairing were affected by temperature and magnesium ion supplementation.The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues:2Sv-2B,2Sv-2D,and 2RL-2BL.The recombination rates were 1.68%,0.17%,and 0%,respectively.The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present,both in wheat haploids and hexaploids.The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree,permitting homoeologous crossing over but only between closely related chromosomes;there was no crossing over between more differentiated chromosomes.Therefore,the phKL system(QPh.sicau-3A)can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.

A simple rule for finding Dirac cones in bilayered perovskites

A simple rule for finding Dirac cone electronic states in solids is proposed, which is neglecting those lattice atoms inert to particular electronic bands, and pursuing the two-dimensional(2D) graphene-like quasi-atom lattices with s-and pbindings by considering the equivalent atom groups in the unit cell as quasi-atoms.Taking CsPbBr3 and Cs3Bi2Br9 bilayers as examples, we prove the effectiveness and generality of this rule with the density functional theory(DFT) calculations.We demonstrate that both bilayers have Dirac cones around the Fermi level and reveal that their corresponding Fermi velocities can reach as high as^0.2 × 10^6 m/s.This makes these new 2D layered materials very promising in making new ultra-fast ionic electronic devices.

CGG repeat expansion in LOC642361/NUTM2B-AS1 typically presents as oculopharyngodistal myopathy

CGG repeat expansions in LOC642361/NUTM2B-AS1 have recently been identified as a cause of oculopharyngeal myopathy with leukoencephalopathy.However,since only three patients from a single family were reported,it remains unknown whether their clinicopathological features are typical for CGG repeat expansions in LOC642361/NUTM2B-AS1.Here,using repeat-primed-polymerase chain reaction and long-read sequencing,we identify 12 individuals from 3 unrelated families with CGG repeat expansions in LOC642361/NUTM2B-AS1,typically presenting with oculopharyngodistal myopathy.The CGG repeat expansions range from 161 to 669 repeat units.Most of the patients present with ptosis,restricted eye movements,dysphagia,dysarthria,and diffuse limb muscle weakness.Only one patient shows T2-weighted hyperintensity in the cerebellar white matter surrounding the deep cerebellar nuclei on brain magnetic resonance imaging.Muscle biopsies from three patients show a myopathic pattern and rimmed vacuoles.Analyses of muscle biopsies suggest that CGG repeat expansions in LOC642361/NUTM2B-AS1 may deleteriously affect aggrephagic capacity,suggesting that RNA toxicity and mitochondrial dysfunction may contribute to pathogenesis.Our study thus expands the phenotypic spectrum for the CGG repeat expansion of LOC642361/NUTM2B-AS1 and indicates that this genetic variant typically manifests as oculopharyngodistal myopathy with chronic myopathic changes with rimmed vacuoles and filamentous intranuclear inclusions in muscle fibers.

Particle distributions in Lamb wave based acoustofluidics

Acoustic streaming enabled by a Lamb wave resonator(LWR)is efficient for particle trapping and enrichment in microfluidic channels.However,because Lamb waves combine the features of bulk acoustic waves and surface acoustic waves,the resulting acoustic streaming in the LWR occurs in multiple planes,and the particle flow behavior in this acoustofluidic system is largely unknown.Reported here are numerical simulations and laboratory experiments conducted to investigate the boundary conditions for particle motion inside a microvortex induced by an LWR.Upon dynamic capture,the particles’trajectories become orbital paths within an acoustic vortex.The suspended particles encounter two distinct acoustic phenomena,i.e.,the drag force resulting from acoustic streaming and the acoustic radiation force,which exert forces in various directions on the particles.When the acoustic radiation force and the fluid drag force are dominant for large and small particles in a mixed solution,respectively,the large particles reside within the vortex while the small particles remain at its periphery.Conversely,when the acoustic radiation force is dominant for both types of particles,the distribution pattern is reversed.

原位表面掺杂增强PtNiCoRh纳米晶对C_(1)燃料电氧化的催化性能

异质原子掺杂的铂基纳米晶在多相催化领域具有广阔的应用前景,然而基于原位表面掺杂策略来优化表面原子构型仍颇具挑战.本研究通过原位表面掺杂的化学方法制备出多枝状PtNiCoRh四元金属纳米晶.抗坏血酸和铑离子的配位作用实现了铑离子的延迟还原,从而可控地将铑原子锚定在催化剂表面层.电催化研究表明原位表面掺杂的Pt_(67)Ni_(16)Co_(16)Rh_(1)纳米晶针对甲醇、甲醛和甲酸电氧化都具有优异的催化活性、稳定性及抗CO中毒特性.原位电化学红外光谱结果表明抗腐蚀性强的铑原子的表面掺杂能有效调控催化剂表面Pt位点,其中CO中毒中间体以更容易氧化消除的桥位态吸附在Rh–Pt异质位点.本研究提出的原位表面掺杂策略将有助于设计高原子利用率的高效多相催化剂.