Regulation of 2-acetyl-1-pyrroline and grain quality in early-season indica fragrant rice by nitrogen and silicon fertilization under different plantation methods

Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and fragrance of fragrant rice.However,the core commercial rice production attributes,namely the head rice yield(HRY)and 2-acetyl-1-pyrroline(2-AP)content of fragrant rice,under various nitrogen and silicon(N-Si)fertilization levels and different plantation methods remain unknown.The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars(Yuxiangyouzhan and Xiangyaxiangzhan).They were grown under six N-Si fertilization treatments(combinations of two levels of Si fertilizer,0 kg Si ha^(−1)(Si0)and 150 kg Si ha^(−1)(Si1),and three levels of N fertilizer,0 kg N ha^(−1)(N0),150 kg N ha^(−1)(N1),and 220 kg N ha^(−1)(N2))and three plantation methods(artificial transplanting(AT),mechanical transplanting(MT),and mechanical direct-seeding(MD)).The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars.Compared with the Si0N0 treatment,the N-Si fertilization treatments resulted in higher HRY and 2-AP contents.The rates of brown rice,milled rice,head rice,and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments.The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice,and affected their antioxidant response parameters.The key parameters for the HRY and 2-AP content were assessed by redundancy analysis.Furthermore,the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity,N use efficiency,and grain quality of fragrant rice.Moreover,high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis.The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content,whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.

RRT Autonomous Detection Algorithm Based on Multiple Pilot Point Bias Strategy and Karto SLAM Algorithm

A Rapid-exploration Random Tree(RRT)autonomous detection algorithm based on the multi-guide-node deflection strategy and Karto Simultaneous Localization and Mapping(SLAM)algorithm was proposed to solve the problems of low efficiency of detecting frontier boundary points and drift distortion in the process of map building in the traditional RRT algorithm in the autonomous detection strategy of mobile robot.Firstly,an RRT global frontier boundary point detection algorithm based on the multi-guide-node deflection strategy was put forward,which introduces the reference value of guide nodes’deflection probability into the random sampling function so that the global search tree can detect frontier boundary points towards the guide nodes according to random probability.After that,a new autonomous detection algorithm for mobile robots was proposed by combining the graph optimization-based Karto SLAM algorithm with the previously improved RRT algorithm.The algorithm simulation platform based on the Gazebo platform was built.The simulation results show that compared with the traditional RRT algorithm,the proposed RRT autonomous detection algorithm can effectively reduce the time of autonomous detection,plan the length of detection trajectory under the condition of high average detection coverage,and complete the task of autonomous detection mapping more efficiently.Finally,with the help of the ROS-based mobile robot experimental platform,the performance of the proposed algorithm was verified in the real environment of different obstacles.The experimental results show that in the actual environment of simple and complex obstacles,the proposed RRT autonomous detection algorithm was superior to the traditional RRT autonomous detection algorithm in the time of detection,length of detection trajectory,and average coverage,thus improving the efficiency and accuracy of autonomous detection.

Solvent extraction and separation of cobalt from leachate of spent lithium-ion battery cathodes with N263 in nitrite media

To effectively separate and recover Co(Ⅱ) from the leachate of spent lithium-ion battery cathodes,we investigated solvent extraction with quaternary ammonium salt N263 in the sodium nitrite system.NO_(2)^(-)combines with Co(Ⅱ) to form an anion [Co(NO_(2))_(3)]^(-),and it is then extracted by N263.The extraction of Co(Ⅱ) is related to the concentration of NO_(2)^(-).The extraction efficiency of Co(Ⅱ) reaches the maximum of99.16%,while the extraction efficiencies of Ni(Ⅱ),Mn(Ⅱ),and Li(Ⅰ) are 9.27%-9.80% under the following conditions:30vol% of N263 and15vol% of iso-propyl alcohol in sulfonated kerosene,the volume ratio of the aqueous-to-organic phase is 2:1,the extraction time is 30 min,and1 M sodium nitrite in 0.1 MHNO_(3).The theoretical stages require for the Co(Ⅱ) extraction are performed in the McCabe–Thiele diagram,and the extraction efficiency of Co(Ⅱ) reaches more than 99.00% after three-stage counter-current extraction with Co(Ⅱ) concentration of 2544mg/L.When the HCl concentration is 1.5 M,the volume ratio of the aqueous-to-organic phase is 1:1,the back-extraction efficiency of Co(Ⅱ)achieves 91.41%.After five extraction and back-extraction cycles,the Co(Ⅱ) extraction efficiency can still reach 93.89%.The Co(Ⅱ) extraction efficiency in the actual leaching solution reaches 100%.

Cell division cyclin 25C knockdown inhibits hepatocellular carcinoma development by inducing endoplasmic reticulum stress

BACKGROUND Cell division cyclin 25C(CDC25C)is a protein that plays a critical role in the cell cycle,specifically in the transition from the G2 phase to the M phase.Recent research has shown that CDC25C could be a potential therapeutic target for cancers,particularly for hepatocellular carcinoma(HCC).However,the specific regulatory mechanisms underlying the role of CDC25C in HCC tumorigenesis and development remain incompletely understood.AIM To explore the impact of CDC25C on cell proliferation and apoptosis,as well as its regulatory mechanisms in HCC development.METHODS Hepa1-6 and B16 cells were transduced with a lentiviral vector containing shRNA interference sequences(LV-CDC25C shRNA)to knock down CDC25C.Subsequently,a xenograft mouse model was established by subcutaneously injecting transduced Hepa1-6 cells into C57BL/6 mice to assess the effects of CDC25C knockdown on HCC development in vivo.Cell proliferation and migration were evaluated using a Cell Counting Kit-8 cell proliferation assays and wound healing assays,respectively.The expression of endoplasmic reticulum(ER)stress-related molecules(glucose-regulated protein 78,X-box binding protein-1,and C/EBP homologous protein)was measured in both cells and subcutaneous xenografts using quantitative real-time PCR(qRT-PCR)and western blotting.Additionally,apoptosis was investigated using flow cytometry,qRT-PCR,and western blotting.RESULTS CDC25C was stably suppressed in Hepa1-6 and B16 cells through LV-CDC25C shRNA transduction.A xenograft model with CDC25C knockdown was successfully established and that downregulation of CDC25C expression significantly inhibited HCC growth in mice.CDC25C knockdown not only inhibited cell proliferation and migration but also significantly increased the ER stress response,ultimately promoting ER stress-induced apoptosis in HCC cells.CONCLUSION The regulatory mechanism of CDC25C in HCC development may involve the activation of ER stress and the ER stress-induced apoptosis signaling pathway.

Hole density dependent magnetic structure and anisotropy in Fe-pnictide superconductor

The competition between different magnetic structures in hole-doped Fe-pnicitides is explored based on an extended five-orbital Hubbard model including long-range Coulomb interactions.Our results show that the stabilized magnetic structure evolves with increasing hole doping level.Namely,the stripe antiferromagnetic phase dominates at zero doping,while magnetic structures with more antiferromagnetic linking numbers such as the staggered tetramer,staggered trimer,and staggered dimer phases become energetically favorable as the hole density increases.At a certain doping level,energy degeneracy of different magnetic structures appears,indicating strong magnetic frustration and magnetic fluctuations in the system.We suggest that the magnetic competition induced by the hole doping may explain the fast decrease of the Neel temperature TNand the moderately suppressed magnetic moment in the hole doped Fe-pnicitides.Moreover,our results show a sign reversal of the kinetic energy anisotropy as the magnetic ground state evolves,which may be the mechanism behind the puzzling sign reversal of the in-plane resistivity anisotropy in hole-doped Fe-pnicitides.

The T2T genome assembly of soybean cultivar ZH13 and its epigenetic landscapes

Dear Editor,earCultor,Soybean is a crucial source of protein for both humans and livestock and a vital oilseed crop.In 2010,the Department of Energy Joint Genome Institute released the first version of the soybean cultivar genome Williams 82(Schmutz et al.,2010).Since then,numerous soybean genomes have been assembled and annotated,including wild species,cultivars,landraces,and pangenomic assemblies(Shen et al.,2018;Xie et al.,2019;Liu et al.,2020).The Chinese soybean cultivar "Zhonghuang 13"(ZH13),which is widely used in China for its high yield and stress resistance,represents a genetic signature of Asian soybean and is the most complete soybean genome assembled using thirdgeneration sequencing technology(Shen et al.,2019).These genomes have facilitated the study of molecular mechanisms and gene regulation,hastening soybean breeding.Nonetheless,there are still many gaps in these soybean genomes,particularly in the centromere and telomere regions,which have not been assembled and annotated,hindering the development of soybean genomes and functional genomic research.

Strength-toughness improvement of 13Cr4NiMo martensitic stainless steel with thermal cyclic heat treatment

To improve the strength-toughness of 13Cr4NiMo martensitic stainless steel(13-4MSS),a thermal cyclic heat treatment(TCHT)combined with the advantage of tempering was proposed.The microstructures were characterized by scanning electron microscopy,X-ray diffraction and electron backscattered diffraction,and the mechanical behaviors in terms of tensile properties and impact toughness were analyzed in correlation with microstructural evolution.It was found that grains and the martensitic matrix were refined by TCHT through the cyclic quenching transformation and austenite recrystallization,which was conducive to more nucleation quantity of reversed austenite during tempering.Two-sphericalcap nucleation model was used to explain the effect of refined grains of TCHT on the nucleation of reversed austenite.Grain refinement by TCHT improved the brittle fracture stress to reduce the ductile-brittle transition temperature and thus improved the cryogenic impact toughness of 13-4MSS.Reversed austenite distributed at the martensitic lath boundary enhances the crack arrest performance and increases the britle fracture stress.It is concluded that reasonable TCHT plus tempering process significantly improves the strength-toughness of 13-4MSS,reflecting the comprehensive effect of grain refinement and reversed austenite.

Construction of spontaneously polarized ceramic via synergistic mechanical activation-Biomimetic mineralization for activating air and water

Spontaneously polarized crystals with intrinsic electric dipole moment have attracted immense interest as excellent functional materials for extensive applications.It is of great significance to engineer sustainable spontaneously polarized materials with fascinating characteristics and performance for activating air and water.Herein,a novel strategy based on the synergy of mechanical activation(MA)and biomimetic mineralization(BM)was created to construct spontaneously polarized ceramic.MA induced the structural damage of clay and promoted the dissolution of ions and the release of free proteins,contributing to the formation of silicate precursor in BM process.After high temperature firing,the silicate precursor in clay was converted to form KCa_(3)AlCa_(3)Si_(4)O_(16)(hexagonal crystal system,L^(6)symmetry type,and P63 space group)in the resulting spontaneously polarized ceramic.The non-centrosymmetric structure of KCa_(3)AlCa_(3)Si4O_(16)and the high intrinsic electric dipole moments contributed by K(1)polyhedrons resulted in high spontaneous polarization(0.2322μC/cm^(2))and far-infrared emissivity(0.951)of spontaneously polarized ceramic.In air,spontaneously polarized ceramic can activate H_(2)O and O_(2)molecules to form negative air ions owing to surface electric field.In water,spontaneously polarized ceramic can disaggregate large water clusters to form small water clusters ascribed to surface electric field and far-infrared emission;water pH can be regulated from weak acidity to approximate neutrality via the capture of electrons by H+ions to produce releasable hydrogen gas.This work provides great promise for rational design and synthesis of spontaneously polarized materials for functional applications.

Inverse design and accurate optimization of layered structured seeding mechanism for sugarcane planters

Existing sugarcane planters are difficult to have ideal seeding trajectory and motion attitude at the same time, and the speed is difficult to meet the requirements at the critical stage, resulting in poor stability, which ultimately makes it impossible to ensure that the sugarcane seeding is carried out in accordance with the agronomic requirements to ensure that the cane buds are oriented toward the wall of the seeding trench. Aiming at the second-order non-circular planetary gear system pendulum seeding mechanism of the planter, the paper innovatively adopts the combination of inverse design and multi-objective layered accurate optimization to solve the problems of attitude, speed and trajectory that do not meet the requirements of fixed-attitude seeding that still exists in the process of sugarcane seeding. The second-order non-circular planetary gear system is simplified into a three-rod two-degree-of-freedom mechanism, and the radius of the pitch curve of each non-circular gear is solved inversely by actively preplanning the static trajectory of the cane seed motion and analyzing the law of motion of the rod assembly. Determining the range of cane seed attitude angles in different motion phases as the first layer optimization objective, and fine-tuning the position of static trajectory key type value points to achieve the first layer optimization. Based on the non-circular gear pitch curve obtained from optimization, the interpolation points are marked on each non-circular gear pitch curve of the second-order non-circular planetary gear system, and based on the parameter optimization method of human-computer interaction, the radius values corresponding to the interpolation points of the non-circular gear pitch curve are fine-tuned to optimize the pitch curves, so as to satisfy the speed requirements of the cane species in each stage, and at the same time to make the convexity of non-circular gears in line with the principle of gear mesh, so as to complete the second layer of accurate optimization. The results of simulation verification show that the motion trajectory attitude of the virtual prototype is basically consistent with the theoretical model, which verifies the feasibility of the mechanism design. This study provides a new optimized design method for the cane seeding mechanism of sugarcane planters to achieve directional seeding.

A zincophilic molecular brush for a dendrite-free,corrosionresistant,zinc metal anode with a long life cycle

Zinc-based aqueous rechargeable batteries have attracted extensive attention due to their low cost,safety,and environmental friendliness.However,dendrite growth and hydrogen evolution of Zn anodes limit their large-scale application.A new strategy to produce a polyacrylamide/reduced graphene oxide(PAM@rGO)molecular nanobrush coating and control Zn electrolyte interface engineering is proposed for use in highly reversible Zn plating/stripping.Hydrogen evolution is inhibited,and Zn deposition is consolidated using the rich zincophilic functional groups of the branched polyacrylamide chain and the high conductivity of rGO.Due to the synergistic effects of corrosion resistance and dendrite-free growth,PAM@rGO/Zn provides prolonged and reversible Zn plating/stripping.Density functional theory(DFT)calculations expand on homogenized nucleation.The PAM@rGO/Zn||activated carbon(AC)capacitor exhibits long cyclic stability,fast ion transfer,and minimal interfacial impedance.This study provides experimental and theoretical bases for the structural design of Zn anode.

Dealloyed TiCuMn efficiently catalyze the NO reduction and Zn-NO batteries

Electrocatalytic NO reduction reaction offers a sustainable route to achieving environmental protection and NH3 production targets as well.In this work,a class of dealloyed Ti_(60)Cu_(33)Mn_(7)ribbons with enough nanoparticles for the high-efficient NO reduction reaction to NH_(3)is fabricated,reaching an excellent Faradaic efficiency of 93.2%at–0.5 V vs reversible hydrogen electrode and a high NH3 synthesis rate of 717.4μmol·h^(-1)·mgcat.-1 at–0.6 V vs reversible hydrogen electrode.The formed nanoparticles on the surface of the catalyst could facilitate the exposure of active sites and the transportation of various reactive ions and gases.Meanwhile,the Mn content in the TiCuMn ribbons modulates the chemical and physical properties of its surface,such as modifying the electronic structure of the Cu species,optimizing the adsorption energy of N^(*)atoms,decreasing the strength of the NO adsorption,and eliminating the thermodynamic energy barrier,thus improving the NO reduction reaction catalytic performance.Moreover,a Zn-NO battery was fabricated using the catalyst and Zn plates,generating an NH3 yield of 129.1µmol·h^(-1)·cm^(-2)while offering a peak power density of 1.45 mW·cm^(-2).

Hypermethylated GPR135 gene expression is a favorable independent prognostic factor in nasopharyngeal carcinoma

Purpose To investigate the methylation status and expression level of G protein-coupled receptor 135(GPR135)in nasopharyngeal carcinoma(NPC)and determine its prognostic value.Methods The GPR135 methylation data of NPC and normal nasopharyngeal tissues were obtained from the Gene Expression Omnibus(GEO)GSE52068 dataset.The GPR135 promoter region methylation level in four normal nasopharyngeal epithelial tissues and eight NPC tissues was detected by bisulfite sequencing.GPR135 expression in NPC and normal nasopharyngeal tissue was obtained from the GEO GSE13597 dataset.The GPR135 mRNA expression levels in 13 NPC and 26 healthy control tissues were assessed with quantitative real-time PCR(qRT-PCR).The GPR135 expression level in 124 NPC tissue sections was analyzed by immunohistochemistry.The correlation between GPR135 expression and clinicopathological features was analyzed by a chi-square test.GPR135 expression in patients with NPC was evaluated by immunohistochemistry,and its influence on prognosis was assessed by Kaplan-Meier and Cox regression analyses.Results The bisulfite sequencing demonstrated that the GPR135 promoter region was highly methylated in NPC tissues.The immunohistochemistry results revealed that patients with high GPR135 expression had better overall survival(hazard ratio[HR]=0.177,95%confidence interval[95%CI]:0.072–0.437,P=0.008),disease-free survival(HR=0.4401,95%CI:0.222–0.871,P=0.034),and local recurrence-free survival(HR=0.307,95%CI:0.119–0.790,P=0.046)than those with low GPR135 expression.Conclusion GPR135 is hypermethylated in NPC,where high GPR135 expression indicates a positive prognosis.Therefore,GPR135 might be a prognostic indicator.