Establishment of a system for screening and identification of novel bactericide targets in the plant pathogenic bacterium Xanthomonas oryzae pv. oryzae using Tn-seq and SPR

Xanthomonas spp. cause severe bacterial diseases. However, effective strategies for prevention and management of these diseases are scarce. Thus, it is necessary to improve the efficiency of control of diseases caused by Xanthomonas. In this study, Xanthomonas oryzae pv. oryzae(Xoo), which causes rice bacterial leaf blight, has been studied as a representative. A transposon insertion library of Xoo, comprising approximately 200,000 individual insertion mutants, was generated. Transposon sequencing data indicated that the mariner C9 transposase mapped at 35.7–36.4% of all potential insertion sites, revealing 491 essential genes required for the growth of Xoo in rich media. The results show that, compared to the functions of essential genes of other bacteria, the functions of some essential genes of Xoo are unknown, 25 genes might be dangerous for the Xanthomonas group, and 3 are specific to Xanthomonas. High-priority candidates for developing broad-spectrum, Xanthomonas-specific, and environment-friendly bactericides were identified in this study. In addition, this study revealed the possible targets of dioctyldiethylenetriamine using surface plasmon resonance(SPR) in combination with high performance liquid chromatography–mass spectrometry(HPLC–MS). The study also provided references for the research of some certain bactericides with unknown anti-bacterial mode of action. In conclusion, this study urged a better understanding of Xanthomonas,provided meaningful data for the management of bacterial leaf blight, and disclosed selected targets of a novel bactericide.

耦合蝶形天线的石墨烯室温太赫兹探测器

高灵敏度、可室温下工作的太赫兹(THz)探测器是太赫兹在生物技术、量子传输、通信、成像等领域得以应用的关键。本文报道了一种石墨烯太赫兹探测器设计方法,该探测器通过将蝶形天线与石墨烯pn结构建至一个器件中,利用蝶形金属天线将波长为110 mm(2.7 THz)的太赫兹远场光汇聚至约800 nm的石墨烯THz吸收层,同时将这蝶形天线的两极设计为两个独立栅极,将800 nm的吸收层转变为可分离光电子的pn结区,通过增强局域光场增加太赫兹吸收,并同时增强光电子分离效率,将正交极化方向的消光比提升了1到2个数量级,在室温下实现了较低的噪声等效功率(NEP)~1 nW·Hz^(−1/2)。这一设计为太赫兹探测提供了新的技术路径。

Factors affecting poplar wetwood characteristics

Wet wood is an abnormal phenomenon in growing trees,which adversely affects growth,subsequent wood processing and economic values of wood products.In this study,the influences of factors such as clones,afforestation methods,site conditions and climate conditions on the characteristics of poplar wetwood were studied through field investigations in 27 clones from 48 sample plots in 28 counties.Results showed that the incidences of wetwood were almost 100%in all plots.Ratios of wetwood area among the48 plots differed from 15.1 to 90.2%.Wetwood area ratios,moisture contents and pH differed significantly between the 27 clones.Wetwood area ratios of the clones ranged from18.7 to 62.3%.Ratios of wetwood areas were positively correlated with wet wood moisture content and pH,tree age,and negatively correlated with pH of sap wood.The repeatability of wet wood area ratios was 0.52,moderately controlled by genetics.Wetwood moisture content and pH were highly controlled by genetics,indicated by the repeatability of 0.91 and 0.89,respectively.There were significant differences in wetwood area ratios,moisture content and pH between different site conditions,afforestation methods,and geographical regions.Sloping land had the lowest wetwood area ratios and moisture content among four types of sites.Afforestation by direct seeding and rooted cuttings had the lowest wetwood area ratios and moisture content,respectively.In the three geographical regions,the Yellow River Basin had the lowest wetwood values of all three factors.

Micromechanical interlocking structure at the filler/resin interface for dental composites: a review

Dental resin composites(DRCs)are popular materials for repairing caries or dental defect,requiring excellent properties to cope with the complex oral environment.Filler/resin interface interaction has a significant impact on the physicochemical/biological properties and service life of DRCs.

石墨烯玻璃透明薄膜加热特性

石墨烯玻璃透明薄膜不仅具有石墨烯的高导热率和高电导率特性,同时表现出优异的电热转化和宽光谱高透光率特性。本文基于常压化学气相沉积技术获得了玻璃基(高纯石英JGS1)多层石墨烯薄膜,并对其电学特性、透光率以及电加热特性进行了详细的实验研究。结果表明:对于面电阻值为1500Ω∙sq^(−1),透射率为74%的石墨烯玻璃,当施加40 V外加偏压后,石墨烯薄膜可达到185℃的饱和温度,薄膜最高饱和温度达到325℃,加热速率超过18℃∙s^(−1)。与PET(Polyethylene terephthalate)基和硅基转移的石墨烯薄膜相比,直接生长石墨烯玻璃透明薄膜加热能力提高了195%,获得了更高的饱和温度、更短的热响应时间和更快的加热速率,并表现出优异的可重复性和长期稳定性,表明石墨烯玻璃在透明电加热领域中具有更加广阔的应用前景。

Degradable Plastics Are Vulnerable to Cracks

A plastic may degrade in response to a trigger.The kinetics of degradation have long been characterized by the loss of weight and strength over time.These methods of gross characterization,however,are misleading when plastic degrades heterogeneously.Here,we study heterogeneous degradation in an extreme form:the growth of a crack under the combined action of chemistry and mechanics.An applied load opens the crack,exposes the crack front to chemical attack,and causes the crack to outrun gross degradation.We studied the crack growth in polylactic acid(PLA),a polyester in which ester bonds break by hydrolysis.We cut a crack in a PLA film using scissors,tore it using an apparatus,and recorded the crack growth using a camera through a microscope.In our testing range,the crack velocity was insensitive to load but was sensitive to humidity and pH.These findings will aid the development of degradable plastics for healthcare and sustainability.

Theory Study and Application of the BP-ANN Method for Power Grid Short-Term Load Forecasting

Aiming at the low accuracy problem of power system short-term load forecasting by traditional methods, a back-propagation artificial neural network （BP-ANN） based method for short-term load forecasting is presented in this paper. The forecast points are related to prophase adjacent data as well as the periodical long-term historical load data. Then the short-term load forecasting model of Shanxi Power Grid （China） based on BP-ANN method and correlation analysis is established. The simulation model matches well with practical power system load, indicating the BP-ANN method is simple and with higher precision and practicality.

Preparation and Characterization of Natural Bamboo Fiber

In this study,natural bamboo fiber was prepared combining chemical pretreatment with mechanical disc refining,opening,and carding.An orthogonal experiment was designed based on four factors and three levels;thereafter,the manufacturing process was optimized.The length,diameter,tensile strength,and elastic modulus of the bamboo fiber were determined,and the crystallinity and morphology of the fiber were analyzed using X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results showed that the optimum parameters for the chemical pretreatment were a cooking temperature of 130℃,heating time of 2 h,NaOH dosage of 2%,and Na2SO3 dosage of 10%.The cooking yield of bamboo chips was 89.5%,and the carding yield of natural bamboo fiber was 43.0% under the optimum conditions.The length,diameter,tensile strength,and elastic modulus of the obtained fiber were 36.71 mm,0.285 mm,407 MPa,and 27.7 GPa,respectively.XRD analysis and SEM observations showed that the technology used in this study can produce bright and compact natural bamboo fibers with high crystallinity.

Broadband photonic structures for quantum light sources

Quantum light sources serve as one of the key elements in quantum photonic technologies. Such sources made from semiconductor material, e.g., quantum dots (QDs), are particularly appealing because of their great potential of scalability enabled by the modern planar nanofabrication technologies. So far, non-classic light sources based on semiconductor QDs are currently outperforming their counterparts using nonlinear optical process, for instance, parametric down conversion and four-wave mixing. To fully exploring the potential of semiconductor QDs, it is highly desirable to integrate QDs with a variety of photonic nanostructures for better device performance due to the improved light-matter interaction. Among different designs, the photonic nanostructures exhibiting broad operation spectral range is particularly interesting to overcome the QD spectral inhomogeneity and exciton fine structure splitting for the generations of single-photon and entangled photon pair respectively. In this review, we focus on recent progress on high-performance semiconductor quantum light sources that is achieved by integrating single QDs with a variety of broadband photonic nanostructures i.e. waveguide, lens and low-Q cavity.

High-Pressure Synthesis and Thermal Transport Properties of Polycrystalline BAs_x

Polycrystalline BAsx(x=0.80-1.10)compounds with different boron-to-arsenic elemental molar ratios were synthesized by a high-pressure and high-temperature sintering method.Compared with other ambient-pressure synthesis methods,high pressure can significantly promote the reaction speed as well as the reaction yield.As the content of arsenic increases from x=0.91 to 1.10,the thermal conductivity of BAsx gradually increases from 53 to 65 W·m-1·K-1.Furthermore,the temperature dependence of thermal conductivities of these samples reveals an Umklapp scattering due to the increasing phonon population.This work provides a highly efficient method for polycrystalline BAs synthesis.

Tunable quantum dots in monolithic Fabry-Perot microcavities for high-performance single-photon sources

Cavity-enhanced single quantum dots(QDs)are the main approach towards ultra-high-performance solid-state quantum light sources for scalable photonic quantum technologies.Nevertheless,harnessing the Purcell effect requires precise spectral and spatial alignment of the QDs’emission with the cavity mode,which is challenging for most cavities.Here we have successfully integrated miniaturized Fabry-Perot microcavities with a piezoelectric actuator,and demonstrated a bright single-photon source derived from a deterministically coupled QD within this microcavity.Leveraging the cavity-membrane structures,we have achieved large spectral tunability via strain tuning.On resonance,a high Purcell factor of~9 is attained.The source delivers single photons with simultaneous high extraction efficiency of 0.58,high purity of 0.956(2)and high indistinguishability of 0.922(4).Together with its compact footprint,our scheme facilitates the scalable integration of indistinguishable quantum light sources on-chip,therefore removing a major barrier to the development of solid-state quantum information platforms based on QDs.

Single photon emitter deterministically coupled to a topological corner state

Incorporating topological physics into the realm of quantum photonics holds the promise of developing quantum light emitters with inherent topological robustness and immunity to backscattering.Nonetheless,the deterministic interaction of quantum emitters with topologically nontrivial resonances remains largely unexplored.Here we present a single photon emitter that utilizes a single semiconductor quantum dot,deterministically coupled to a second-order topological corner state in a photonic crystal cavity.By investigating the Purcell enhancement of both single photon count and emission rate within this topological cavity,we achieve an experimental Purcell factor of Fp=3.7.Furthermore,we demonstrate the on-demand emission of polarized single photons,with a second-order autocorrelation function g(2)(0)as low as 0.024±0.103.Our approach facilitates the customization of light-matter interactions in topologically nontrivial environments,thereby offering promising applications in the field of quantum photonics.

Ultraclean transfer of graphene by mechanically exfoliating polymer with modified crosslink density

The transfer of graphene from metallic substrates onto application-specific substrates is usually inevitable for the applications of high-quality graphene films derived from chemical vapour deposition(CVD)approaches.Commonly used to support the graphene films during the transfer,the coating of the polymer would produce the surface contaminations and hinder the industrially compatible transfer.In this work,through the thermal imidization of polyamide acid(PAA)to polyimide(PI)and tuning of the concentration of dangling chains,we achieved the ultraclean and crack-free transfer of graphene wafers with high electronic quality.The resulting contamination-free and hydrophilic surface also enabled the observed improved cell viability in a biomedical applications.By avoiding aqueous etching or the usage of strong bases,our proposed transfer method is industrially compatible for batch transfer of graphene films towards the real applications.

Cadaverine and putrescine exposure influence carbon and nitrogen cycling genes in water and sediment of the Yellow River

The response patterns of microbial functional genes involved in biogeochemical cycles to cadaver decay is a central topic of recent environmental sciences.However,the response mechanisms and pathways of the functional genes associated with the carbon(C)and nitrogen(N)cycling to cadaveric substances such as cadaverine and putrescine remain unclear.This study explored the variation of functional genes associated with C fixation,C degradation and N cycling and their influencing factors under cadaverine,putrescine and mixed treatments.Our results showed only putrescine significantly increased the alpha diversity of C fixation genes,while reducing the alpha diversity of N cycling genes in sediment.For the C cycling,the mixed treatment significantly decreased the total abundance of reductive acetyl-CoA pathway genes(i.e.,acsB and acsE)and lig gene linked to lignin degradation in water,while only significantly increasing the hydroxypropionate-hydroxybutylate cycle(i.e.,accA)gene abundance in sediment.For the N cycling,mixed treatment significantly decreased the abundance of the nitrification(i.e.,amoB),denitrification(i.e.,nirS3)genes in water and the assimilation pathway gene(i.e.,gdhA)in sediment.Environmental factors(i.e.,total carbon and total nitrogen)were all negatively associated with the genes of C and N cycling.Therefore,cadaverine and putrescine exposure may inhibit the pathway in C fixation and N cycling,while promoting C degradation.These findings can offer some new insight for the management of amine pollution caused by animal cadavers.

An Injectable silk-based hydrogel as a novel biomineralization seedbed for critical-sized bone defect regeneration

The healing process of critical-sized bone defects urges for a suitable biomineralization environment. However, the unsatisfying repair outcome usually results from a disturbed intricate milieu and the lack of in situ mineralization resources. In this work, we have developed a composite hydrogel that mimics the natural bone healing processes and serves as a seedbed for bone regeneration. The oxidized silk fibroin and fibrin are incorporated as rigid geogrids, and amorphous calcium phosphate (ACP) and platelet-rich plasma serve as the fertilizers and loam, respectively. Encouragingly, the seedbed hydrogel demonstrates excellent mechanical and biomineralization properties as a stable scaffold and promotes vascularized bone regeneration in vivo. Additionally, the seedbed serves a succinate-like function via the PI3K-Akt signaling pathway and subsequently orchestrates the mitochondrial calcium uptake, further converting the exogenous ACP into endogenous ACP. Additionally, the seedbed hydrogel realizes the succession of calcium resources and promotes the evolution of the biotemplate from fibrin to collagen. Therefore, our work has established a novel silk-based hydrogel that functions as an in-situ biomineralization seedbed, providing a new insight for critical-sized bone defect regeneration.

Revolutionising oral organoids with artificial intelligence

The convergence of organoid technology and artificial intelligence(AI)is poised to revolutionise oral healthcare.Organoids-three-dimensional structures derived from human tissues-offer invaluable insights into the complex biology of diseases,allowing researchers to effectively study disease mechanisms and test therapeutic interventions in environments that closely mimic in vivo conditions.In this review,we first present the historical development of organoids and delve into the current types of oral organoids,focusing on their use in disease models,regeneration and microbiome intervention.We then compare single-source and multi-lineage oral organoids and assess the latest progress in bioprinted,vascularised and neural-integrated organoids.In the next part of the review,we highlight significant advancements in AI,emphasising how AI algorithms may potentially promote organoid development for early disease detection and diagnosis,personalised treatment,disease prediction and drug screening.However,our main finding is the identification of remaining challenges,such as data integration and the critical need for rigorous validation of AI algorithms to ensure their clinical reliability.Our main viewpoint is that current AI-enabled oral organoids are still limited in applications but,as we look to the future,we offer insights into the potential transformation of AI-integrated oral organoids in oral disease diagnosis,oral microbial interactions and drug discoveries.By synthesising these components,this review aims to provide a comprehensive perspective on the current state and future implications of AI-enabled oral organoids,emphasising their role in advancing oral healthcare and improving patient outcomes.

Ultra-low threshold continuous-wave quantum dot mini-BIC lasers

Highly compact lasers with ultra-low threshold and single-mode continuous wave(CW)operation have been a long sought-after component for photonic integrated circuits(PICs).Photonic bound states in the continuum(BICs),due to their excellent ability of trapping light and enhancing light-matter interaction,have been investigated in lasing configurations combining various BIC cavities and optical gain materials.However,the realization of BIC laser with a highly compact size and an ultra-low CW threshold has remained elusive.We demonstrate room temperature CW BIC lasers in the 1310 nm O-band wavelength range,by fabricating a miniaturized BIC cavity in an InAs/GaAs epitaxial quantum dot(QD)gain membrane.By enabling effective trapping of both light and carriers in all three dimensions,ultra-low threshold of 12μW(0.052 kW cm^(-2))is achieved at room temperature.Single-mode lasing is also realized in cavities as small as only 5×5 unit cells(~2.5×2.5μm^(2) cavity size)with a mode volume of 1.16(λ/n)^(3).The maximum operation temperature reaches 70℃ with a characteristic temperature of T_(0)~93.9 K.With its advantages in terms of a small footprint,ultra-low power consumption,and adaptability for integration,the mini-BIC lasers offer a perspective light source for future PICs aimed at high-capacity optical communications,sensing and quantum information.

Heterozygous CARD9 mutation favors the development of allergic bronchopulmonary aspergillosis

Background:Previous research demonstrated that a homozygous mutation of g.136372044G>A(S12N)in caspase recruitment domain family member 9(CARD9)is critical for producing Aspergillus fumigatus-induced(Af-induced)T helper 2(T_(H)2)-mediated responses in allergic bronchopulmonary aspergillosis(ABPA).However,it remains unclear whether the CARD9^(S12N)mutation,especially the heterozygous occurrence,predisposes the host to ABPA.Methods:A total of 61 ABPA patients and 264 controls(including 156 healthy controls and 108 asthma patients)were recruited for sequencing the CARD9 locus to clarify whether patients with this heterozygous single-nucleotide polymorphisms are predisposed to the development of ABPA.A series of in vivo and in vitro experiments,such as quantitative real-time polymerase chain reaction,flow cytometry,and RNA isolation and quantification,were used to illuminate the involved mechanism of the disease.Results:The presence of the p.S12N mutation was associated with a significant risk of ABPA in ABPA patients when compared with healthy controls and asthma patients,regardless of Aspergillus sensitivity.Relative to healthy controls without relevant allergies,the mutation of p.S12N was associated with a significant risk of ABPA(OR:2.69 and 4.17 for GA and AA genotypes,P=0.003 and 0.029,respectively).Compared with patients with asthma,ABPA patients had a significantly higher heterozygous mutation(GA genotype),indicating that p.S12N might be a significant ABPA-susceptibility locus(aspergillus sensitized asthma:OR:3.02,P=0.009;aspergillus unsensitized asthma:OR:2.94,P=0.005).The mutant allele was preferentially expressed in ABPA patients with heterozygous CARD9^(S12N),which contributes to its functional alterations to facilitate Af-induced T_(H)2-mediated ABPA development.In terms of mechanism,Card9 wild-type(Card9^(WT))expression levels decreased significantly due to Af-induced decay of its messenger RNA compared to the heterozygous Card9 S12N.In addition,ABPA patients with heterozygous CARD9^(S12N)had increased Af-induced interleukin-5 production.Conclusion:Our study provides the genetic evidence showing that the heterozygous mutation of CARD9^(S12N),followed by allele expression imbalance of CARD9^(S12N),facilitates the development of ABPA.

Deep-learning based on-chip rapid spectral imaging with high spatial resolution

Spectral imaging extends the concept of traditional color cameras to capture images across multiple spectral channels and has broad ap-plication prospects.Conventional spectral cameras based on scanning methods suffer from the drawbacks of low acquisition speed and large volume.On-chip computational spectral imaging based on metasur-face filters provides a promising scheme for portable applications,but endures long computation time due to point-by-point iterative spec-tral reconstruction and mosaic effect in the reconstructed spectral im-ages.In this study,on-chip rapid spectral imaging was demonstrated,which eliminated the mosaic effect in the spectral image by deep-learning-based spectral data cube reconstruction.The experimental results show that 4 orders of magnitude faster than the iterative spec-tral reconstruction were achieved,and the fidelity of the spectral re-construction for the standard color plate was over 99%for a standard color board.In particular,video-rate spectral imaging was demon-strated for moving objects and outdoor driving scenes with good per-formance for recognizing metamerism,where the concolorous sky and white cars can be distinguished via their spectra,showing great po-tential for autonomous driving and other practical applications in the field of intelligent perception.

In-orbit performance of ME onboard Insight-HXMT in the first 5 years

Introduction The medium-energy X-ray telescope(ME)is a collimated X-ray telescope onboard the Insight hard X-ray modulation telescope(Insight-HXMT)satellite.It has 1728 Si-PIN pixels readout using 54 low noise application-specific integrated circuits(ASICs).ME covers the energy range of 5–30 keV and has a total detection area of 952cm2.The typical energy resolution of ME at the beginning of the mission is 3 keV at 17.8 keV(full width at half maximum,FWHM),and the time resolution is 255μs.In this study,we present the in-orbit performance of ME in its first 5 years of operation.Methods The performance of ME was monitored using onboard radioactive sources and astronomical X-ray objects.ME carries six 241Am radioactive sources for onboard calibration,which can continuously illuminate the calibration pixels.The long-term performance evolution of ME can be quantified using the properties of the accumulated spectra of the calibration pixels.In addition,observations of the Crab Nebula and the pulsar were used to check the long-term evolution of the detection efficiency as a function of energy.Conclusion After 5 years of operation,742cm2 of the Si-PIN pixelswere stillworking normally.The peak positions of 241Am emission lines gradually shifted to the high-energy region,implying a slow increase in ME gain of 1.43%.A comparison of the ME spectra of the Crab Nebula and the pulsar shows that the E–C relations and the redistribution matrix file are still acceptable for most data analysis works,and there is no detectable variation in the detection efficiency.