A Data-Driven Real-Time Trajectory Planning and Control Methodology for UGVs Using LSTMRDNN

Dear Editor,This letter presents a novel data-driven trajectory planning and control scheme for the unmanned ground vehicles(UGVs).A recent work[1]has demonstrated the effectiveness of approximating the optimal state feedback for a nonlinear unmanned system via deep neural network(DNN).

分子骨架编辑在药物合成中的应用与展望

分子编辑是有机合成领域亘古不变的研究热点,其包括外围编辑与骨架编辑。在过去,分子编辑往往着重于C―H键的外围编辑,而骨架编辑则是近年来新兴起的方法学。这一类反应操作简单,专一性强,可以大幅简化合成路线,在药物合成与开发领域应用广泛。本文基于常见的几类分子编辑反应,通过与传统方法对比的方式介绍两例分子骨架编辑在药物合成中的应用,并通过对该领域前沿发展的介绍,对该方法学的未来应用进行展望。

Policy and Management of Carbon Peaking and Carbon Neutrality:A Literature Review

The vision of reaching a carbon peak and achieving carbon neutrality is guiding the low-carbon transition of China’s socioeconomic system.Currently,a research gap remains in the existing literature in terms of studies that systematically identify opportunities to achieve carbon neutrality.To address this gap,this study comprehensively collates and investigates 1105 published research studies regarding carbon peaking and carbon neutrality.In doing so,the principles of development in this area are quantitively analyzed from a space–time perspective.At the same time,this study traces shifts and alterations in research hotspots.This systematic review summarizes the priorities and standpoints of key industries on carbon peaking and carbon neutrality.Furthermore,with an emphasis on five key management science topics,the scientific concerns and strategic demands for these two carbon emission-reduction goals are clarified.The paper ends with theoretical insights on and practical countermeasures for actions,priority tasks,and policy measures that will enable China to achieve a carbon-neutral future.This study provides a complete picture of the research status on carbon peaking and carbon neutrality,as well as the research directions worth investigating in this field,which are crucial to the formulation of carbon peak and carbon neutrality policies.

Engineering Introns to Express RNA Guides for Cas9- and Cpfl-Mediated Multiplex Genome Editing

The clustered regularly interspaced short palindromic repeat （CRISPR） system has emerged as the revolu- tionary platform for DNA targeting. This system uses a site-specific RNA guide to direct a CRISPR effector （e.g., Cas9 and Cpfl） to a DNA target. Here, we elaborate a general strategy to simultaneously express multiple guide RNAs （gRNA） and CRISPR RNAs （crRNA） from introns of Cas9 and Cpfl. This method utilizes the endogenous tRNA processing system or crRNA processing activity of Cpfl to cleave the spliced intron that contains tRNA-gRNA polycistron or crRNA-crRNA array. We demonstrated that the tRNA-gRNA intron is able to fuse with Cas9 as one gene. Such a hybrid gene could be expressed using one polymerase II promoter, and exhibited high efficiency and robustness in simultaneously targeting multiple sites. We also implemented this strategy in Cpfl-mediated genome editing using intronic tRNA-crRNA and crRNA-crRNA arrays. Interestingly, hybrid genes containing Cpfl and intronic crRNA array exhibited remarkably increased efficiency compared with the conventional Cpfl vectors. Taken together, this study presents a method to express CRISPR reagents from one hybrid gene to increase genome-editing efficiency and capacity. Owing to its simplicity and versatility, this method could be broadly used to develop sophisticated CRISPR tools in eukaryotes.

A FLASH pipeline for arrayed CRISPR library construction and the gene function discovery of rice receptor-like kinases

Clustered regularly interspaced short palindromic repeats(CRISPR)-CRISPR-associated protein 9(Cas9)-mediated gene editing is revolutionizing plant research and crop breeding.Here,we present an effective and streamlined pipeline for arrayed CRISPR library construction and demonstrate it is suitable for small-to large-scale genome editing in plants.This pipeline introduces artificial PCR fragment-length markers for distinguishing guide RNAs(gRNAs)(FLASH),and a group of 12 constructs harboring different FLASH tags are co-transformed into plants each time.The identities of gRNAs in Agrobacterium mixtures and trans-genic plants can therefore be read out by detecting the FLASH tags,a process that requires only conven-tional PCR and gel electrophoresis rather than sequencing.We generated an arrayed CRISPR library target-ing all 1,072 members of the receptor-like kinase(RLK)family in rice.One-shot transformation generated a mutant population that covers gRNAs targeting 955 RLKs,and 74.3%(710/955)of the target genes had three or more independent T0 lines.Our results indicate that the FLASH tags act as bona fide surrogates for the gRNAs and are tightly(92.1%)associated with frameshift mutations in the target genes.In addition,the FLASH pipeline allows for rapid identification of unintended editing events without corresponding T-DNA integrations and generates high-order mutants of closely related RLK genes.Furthermore,we showed that the RLK mutant library enables rapid discovery of defense-related RLK genes.This study introduces an effective pipeline for arrayed CRISPR library construction and provides genome-wide rice RLK mutant resources for functional genomics.

Structure evolution,dielectric,and conductivity behavior of(K_(0.5)Na_(0.5))NbO_(3)-Bi(Zn_(2/3)Nb_(1/3))O_(3) ceramics

(1-x)K_(0.5)Na_(0.5)Nb0_(3-x)Bi(Zn_(2/3)Nb_(1/3))0_(3)((1-x)KNN-xBZN,x=0.010,0.015,0.020,0.025,and 0.030)lead-free ceramics were fabricated via a traditional solid-state method.The crystal structure,microstructure,dielectric,and conductivity behavior of this system were studied.Combined with X-ray diffraction(XRD)patterns,Rietveld refinement,and dielectric spectroscopy,an orthorhombic phase was determined for x=0.010,an orthorhombic-tetragonal mixed phase was identified for x=0.015,and a rhombohedral symmetry appears in 0.020≤x≤0.030.Both 0.98KNN-0.02BZN and 0.975KNN-0.025BZN ceramics exhibit stable permittivity and low dielectric loss tangent(tan)in wide temperature ranges owing to the combination of rhombohedral-tetragonal step-like feature and the diffuse phase transition from tetragonal to cubic.The activation energies of dielectric relaxation and conductivity behavior at high temperatures initially decrease slightly,then drop sharply,and finally decline slowly,which could be attributed to microstructure morphologies and the concentration of oxygen vacancies.