Targeted mutagenesis of amino acid transporter genes for rice quality improvement using the CRISPR/Cas9 system

High grain protein content(GPC) reduces rice eating and cooking quality(ECQ). We generated OsAAP6 and OsAAP10 knockout mutants in three high-yielding japonica varieties and one japonica line using the CRISPR/Cas9 system. Mutation efficiency varied with genetic background in the T_0 generation, and GPC in the T_1 generation decreased significantly,owing mainly to a reduction in glutelin content. Amylose content was down-regulated significantly in some Osaap6 and all Osaap10 mutants. The increased taste value of these mutants was supported by Rapid Visco Analysis(RVA) profiles, which showed higher peak viscosity and breakdown viscosity and lower setback viscosity than the wild type. There were no significant deficiencies in agronomic traits of the mutants. Targeted mutagenesis of OsAAP6 and OsAAP10, especially OsAAP10, using the CRISPR/Cas9 system can rapidly reduce GPC and improve ECQ of rice, providing a new strategy for the breeding cultivars with desired ECQ.

Brassinosteroid and gibberellin coordinate rice seed germination and embryo growth by regulating glutelin mobilization

Seed germination is the beginning of a new lifecycle,and involves many complex physiological and biochemical reactions including seed reserve mobilization in the endosperm and nutrient transport and reuse in the embryo.Although glutelin is a dominant storage protein in rice,its contribution to seed germination and its regulatory mechanisms are mostly unknown.Gibberellin (GA) and brassinosteroid (BR),two major growth-promoting phytohormones,also play positive roles in controlling seed germination.However,how GA and BR interact and coordinate seed germination and facilitate glutelin mobilization remains unclear.In the present study,biochemical and physiological analyses of seed germination indicated that both GA and BR promote seed germination and post-germination growth.Exogenous application of GA restored germination defects caused by BR deficiency or insensitivity.Proteomic and q RT-PCR results showed that the expression of several glutelin proteins and their encoding genes was induced by BR and GA in the embryo.Expression assays suggested that the increased accumulation of glutelin protein in the embryo was due to the accelerated degradation of glutelin by a cysteine proteinase (REP-1) in the endosperm.The breakdown of glutelin in the endosperm showed a strict positive correspondence with the length of the shoot.The GluA2 mutation led to reduced degradation rate of glutelin and defects in seed germination,and the promotion effect of GA on seed germination was weakened in the glua2mutant.In vitro culture assay of rice embryos showed that glutelin mobilization functioned downstream of the GA and BR pathways to promote shoot elongation.These findings suggest a mechanism that mediates crosstalk between BR and GA in co-regulating rice seed germination and embryo growth.

内嵌金属碳氮化物团簇富勒烯的稳定性与生成机理

对新结构富勒烯金属包合物的探索是富勒烯领域中的研究重点。本文从内嵌团簇与富勒烯碳笼尺寸匹配的角度出发,对基于金属碳氮化物团簇的新结构富勒烯金属包合物进行了研究。通过量子化学计算研究了M_(3)NC团簇(M=Y,La,Gd)内嵌在D_(2)(186)-C_(96)和D_(2)(35)-C_(88)分子中所形成包合物的稳定性和电子结构,发现富勒烯碳笼接受内嵌团簇转移的六个电子形成了稳定结构。结合文献已报道过的Sc_(3)NC@Ih(7)-C_(80)分子,阐明了M_(3)NC团簇与富勒烯碳笼之间的尺寸匹配效应,并发现D_(2)(186)-C_(96)、D2(35)-C_(88)和Ih(7)-C_(80)三种富勒烯碳笼均具有五元环均匀分布的结构特点。我们对富勒烯之间的转变路径进行了研究,提出了不含Stone-Wales异构化过程的富勒烯直接生成机理,即可以通过增加碳原子的过程使五元环重排,在保持稳定性结构单元的同时转变为更大碳笼。

Brillouin Klein space and half-turn space in three-dimensional acoustic crystals

The Bloch band theory and Brillouin zone(BZ)that characterize wave-like behaviors in periodic mediums are two cornerstones of contemporary physics,ranging from condensed matter to topological physics.Recent theoretical breakthrough revealed that,under the projective symmetry algebra enforced by artificial gauge fields,the usual two-dimensional(2D)BZ(orientable Brillouin two-torus)can be fundamentally modified to a non-orientable Brillouin Klein bottle with radically distinct manifold topology.However,the physical consequence of artificial gauge fields on the more general three-dimensional(3D)BZ(orientable Brillouin three-torus)was so far missing.Here,we theoretically discovered and experimentally observed that the fundamental domain and topology of the usual 3D BZ can be reduced to a non-orientable Brillouin Klein space or an orientable Brillouin half-turn space in a 3D acoustic crystal with artificial gauge fields.We experimentally identify peculiar 3D momentum-space non-symmorphic screw rotation and glide reflection symmetries in the measured band structures.Moreover,we experimentally demonstrate a novel stacked weak Klein bottle insulator featuring a nonzero Z2 topological invariant and self-collimated topological surface states at two opposite surfaces related by a nonlocal twist,radically distinct from all previous 3D topological insulators.Our discovery not only fundamentally modifies the fundamental domain and topology of 3D BZ,but also opens the door towards a wealth of previously overlooked momentum-space multidimensional manifold topologies and novel gaugesymmetry-enriched topological physics and robust acoustic wave manipulations beyond the existing paradigms.

EMPSI:Efficient multiparty private set intersection(with cardinality)

Multiparty private set intersection(PSI)allows several parties,each holding a set of elements,to jointly compute the intersection without leaking any additional information.With the development of cloud computing,PSI has a wide range of applications in privacy protection.However,it is complex to build an efficient and reliable scheme to protect user privacy.To address this issue,we propose EMPSI,an efficient PSI(with cardinality)protocol in a multiparty setting.EMPSI avoids using heavy cryptographic primitives(mainly rely on symmetric-key encryption)to achieve better performance.In addition,both PSI and PSI with the cardinality of EMPSI are secure against semi-honest adversaries and allow any number of colluding clients(at least one honest client).We also do experiments to compare EMPSI with some state-of-the-art works.The experimental results show that proposed EMPSI(-CA)has better performance and is scalable in the number of clients and the set size.

Demonstration of topological wireless power transfer

Recent advances in non-radiative wireless power transfer(WPT)technique essentially relying on magnetic resonance and near-field coupling have successfully enabled a wide range of applications.However,WPT systems based on double resonators are severely limited to short-or mid-range distance,due to the deteriorating efficiency and power with long transfer distance.WPT systems based on multi-relay resonators can overcome this problem,which,however,suffer from sensitivity to perturbations and fabrication imperfections.Here,we experimentally demonstrate a concept of topological wireless power transfer(TWPT),where energy is transferred efficiently via the near-field coupling between two topological edge states localized at the ends of a one-dimensional radiowave topological insulator.Such a TWPT system can be modelled as a parity-time-symmetric Su-Schrieffer-Heeger(SSH)chain with complex boundary potentials.Besides,the coil configurations are judiciously designed,which significantly suppress the unwanted cross-couplings between nonadjacent coils that could break the chiral symmetry of the SSH chain.By tuning the inter-and intra-cell coupling strengths,we theoretically and experimentally demonstrate high energy transfer efficiency near the exceptional point of the topological edge states,even in the presence of disorder.The combination of topological metamaterials,non-Hermitian physics,and WPT techniques could promise a variety of robust,efficient WPT applications over long distances in electronics,transportation,and industry.

Rapid improvement of rice eating and cooking quality through gene editing toward glutelin as target

Rice eating and cooking quality(ECQ)is a major concern of breeders and consumers,determining market competitiveness worldwide.Rice grain protein content(GPC)is negatively related to ECQ,making it possible to improve ECQ by manipulating GPC.However,GPC is genetically complex and sensitive to environmental conditions;therefore,little progress has been made in traditional breeding for ECQ.Here,we report that CRISPR/Cas9-mediated knockout of genes encoding the grain storage protein glutelin rapidly produced lines with downregulated GPC and improved ECQ.Our finding provides a new strategy for improving rice ECQ.

Photonic amorphous topological insulator

The current understanding of topological insulators and their classical wave analogs,such as photonic topological insulators,is mainly based on topological band theory.However,standard band theory does not apply to amorphous phases of matter,which are formed by non-crystalline lattices with no long-range positional order but only shortrange order,exhibiting unique phenomena such as the glass-to-liquid transition.Here,we experimentally investigate amorphous variants of a Chern number-based photonic topological insulator.By tuning the disorder strength in the lattice,we demonstrate that photonic topological edge states can persist into the amorphous regime prior to the glass-to-liquid transition.After the transition to a liquid-like lattice configuration,the signatures of topological edge states disappear.This interplay between topology and short-range order in amorphous lattices paves the way for new classes of non-crystalline topological photonic bandgap materials.

Spiral Field Generation in Smith-Purcell Radiation by Helical Metagratings

Moving electrons interacting with media can give rise to electromagnetic radiations and has been emerged as a promising platform for particle detection,spectroscopies,and free-electron lasers.In this letter,we investigate the Smith-Purcell radiation from helical metagratings,chiral structures similar to deoxyribonucleic acid(DNA),in order to understand the interplay between electrons,photons,and object chirality.Spiral feld patterns can be generated while introducing a gradient azimuthal phase distribution to the induced electric dipole array at the cylindrical interface.Experimental measurements show efcient control over angular momentum of the radiated feld at microwave regime,utilizing a phased electromagnetic dipole array to mimic moving charged particles.Te angular momentum of the radiated wave is determined solely by the handedness of the helical structure,and it thus serves as a potential candidate for the detection of chiral objects.Our fndings not only pave a way for design of orbital angular momentum free-electron lasers but also provide a platform to study the interplay between swif electrons with chiral objects.

Topological metasurface:from passive toward active and beyond

Metasurfaces are subwavelength structured thin films consisting of arrays of units that allow the control of polarization,phase,and amplitude of light over a subwavelength thickness.Recent developments in topological photonics have greatly broadened the horizon in designing metasurfaces for novel functional applications.In this review,we summarize recent progress in the research field of topological metasurfaces,first from the perspectives of passive and active in the classical regime,and then in the quantum regime.More specifically,we begin by examining the passive topological phenomena in two-dimensional photonic systems,including both time-reversal broken systems and time-reversal preserved systems.Subsequently,we discuss the cutting-edge studies of active topological metasurfaces,including nonlinear topological metasurfaces and reconfigurable topological metasurfaces.After overviewing topological metasurfaces in the classical regime,we show how they could provide a new platform for quantum information and quantum many-body physics.Finally,we conclude and describe some challenges and future directions of this fast-evolving field.

Experimental Realization of an Extreme-Parameter Omnidirectional Cloak

An ideal transformation-based omnidirectional cloak always relies on metamaterials with extreme parameters,which were previously thought to be too difcult to realize.For such a reason,in previous experimental proposals of invisibility cloaks,the extreme parameters requirements are usually abandoned,leading to inherent scattering.Here,we report on the frst experimental demonstration of an omnidirectional cloak that satisfes the extreme parameters requirement,which can hide objects in a homogenous background.Instead of using resonant metamaterials that usually involve unavoidable absorptive loss,the extreme parameters are achieved using a nonresonant metamaterial comprising arrays of subwavelength metallic channels manufactured with 3D metal printing technology.A high level transmission of electromagnetic wave propagating through the present omnidirectional cloak,as well as signifcant reduction of scattering feld,is demonstrated both numerically and experimentally.Our work may also inspire experimental realizations of the other full-parameter omnidirectional optical devices such as concentrator,rotators,and optical illusion apparatuses.

急性脑梗死后出血转化合并感染性心内膜炎一例及文献复习

患者男性,47岁,主因“左侧肢体乏力、胡言乱语4h余”就诊于海南医学院第一附属医院(简称我院)。患者4h前休息中突发左侧肢体乏力,表现为左上肢不能持物,左下肢不能行走,伴胡言乱语,伴发热,无抽搐,无头痛、头晕,随后赶至我院急诊,急诊完善头颅CT未见出血,遂收住入院。既往有不详高热病史4d.

Flexoelectric-induced photovoltaic effects and tunable photocurrents in flexible LaFeO_(3) epitaxial heterostructures

By engineering strain gradients in dielectrics,the flexoelectric effect can be created,which yields interesting physical properties via electromechanical coupling.Here,we report flexoelectric-induced photovoltaic effects in centrosymmetric LaFeO_(3) thin-film heterostructures grown on flexible mica sub-strates,in which partial relaxation of lattice-mismatch strain against LaAlO_(3) stretching layers results in giant strain gradients and pronounced electrical polarizations.The flexoelectric polarization modulates band alignment and leads to significant photovoltaic effects with a short-circuit current density of~0.4 mA/cm^(2) and an open circuit voltage of~-0.45 V in Pt/LaFeO_(3)/LaNiO_(3) devices.In addition,by con-cavely/convexly bending the mica substrate,mechanical strain gradients give rise to bi-directionally tunable photocurrents,in which continuously change of short-circuit current density with a magni-tude of~100% and good reproducibility in repetitive bending operations are observed in the Pt/LaFeO_(3)/LaNiO_(3) devices.The present work demonstrates an approach to design self-powered photoelectric de-vices with an electromechanical degree of freedom based on the flexoelectric effect in flexible thin-film heterostructures.

Unconventional Weyl exceptional contours in non-Hermitian photonic continua

Unconventional Weyl points with topological charges higher than 1 can transform into various complex unconventional Weyl exceptional contours under non-Hermitian perturbations.However,theoretical studies of these exceptional contours have been limited to tight-binding models.Here,we propose to realize unconventional Weyl exceptional contours in photonic continua—non-Hermitian anisotropic chiral plasma,based on ab initio calculation by Maxwell’s equations.By perturbing in-plane permittivity,an unconventional Weyl point can transform into a quadratic Weyl exceptional ring,a type I Weyl exceptional chain with one chain point,a type II Weyl exceptional chain with two chain points,or other forms.Realistic metamaterials with effective constitutive parameters are proposed to implement these unconventional Weyl exceptional contours.Our work paves a way toward exploration of exotic physics of unconventional Weyl exceptional contours in non-Hermitian topological photonic continua.

High-performance bifunctional polarization switch chiral metamaterials by inverse design method

Multifunctional polarization controlling plays an important role in modern photonics,but their designs toward broad bandwidths and high efficiencies are still rather challenging.Here,by applying the inverse design method of model-based theoretical paradigm,we design cascaded chiral metamaterials for different polarization controls in oppositely propagating directions and demonstrate their broadband and high-efficiency performance theoretically and experimentally.Started with the derivation of scattering matrix towards specified polarization control,a chiral metamaterial is designed as a meta-quarter-wave plate for the forward propagating linearly polarized wave,which converts the x-or y-polarized wave into a nearly perfect left-or right-handed circularly polarized wave;intriguingly,it also serves as a 45°polarization rotator for the backward propagating linearly polarized waves.This bifunctional metamaterial shows a high transmission as well as a broad bandwidth due to the Fabry–Perot-like interference effect.Using the similar approach,an abnormal broadband meta-quarter-wave plate is achieved to convert the forward x-and y-polarized or the backward y-and x-polarized waves into left-and right-handed circularly polarized waves with high transmission efficiencies.The integration of multiple functions in a single structure endows the cascaded chiral metamaterials with great interests for the high-efficiency polarization-controlled applications.

Direct current remote cloak for arbitrary objects

Hiding an arbitrary object with a cloak at a distance from an object is of great significance in scientific research,but remains unrealized as a practical device.In this paper,we propose the first experimental realization of a remote cloaking device that makes any object located at a certain distance invisible at direct current(DC)frequency.A negative resistor network with active elements is used to achieve the remote function of the DC cloak.Based on this network,the cloak can remotely generate a hidden region without distorting the currents far from the cloaked region.The experimental results show that any object in the hidden region is invisible to a DC detector.Our cloak does not require any knowledge of the hidden object.The experimental demonstration shows the superiority of this remote cloaking device,which may find potential applications in medical or geologic research.

Negative refraction of ultra-squeezed in-plane hyperbolic designer polaritons

The in-plane negative refraction of high-momentum(i.e.,high-k)photonic modes could enable many applications such as imaging,focusing,and waveguiding in a planar platform at deep-subwavelength scales.However,its practical implementation in experiments remains elusive so far.Here we propose a class of hyperbolic metasurfaces,which is characterized by an anisotropic magnetic sheet conductivity and can support the in-plane ultrahigh-k magnetic designer polaritons.Based on such metasurfaces,we report the experimental observation of the all-angle negative refraction of designer polaritons at extremely deep-subwavelength scales.Moreover,we directly visualize the designer polaritons with hyperbolic dispersions.Importantly,for these hyperbolic polaritons,we find that their squeezing factor is ultra-large.To be specific,it can be up to 129 in the experiments,an ultra-high value exceeding those in naturally hyperbolic materials.This work may pave a way toward exploring the extremely high confinement and unusual propagation of magnetic designer polaritons over monolayer or twisted bilayer hyperbolic metasurfaces.