An Optimized Chinese Filtering Model Using Value Scale Extended Text Vector

With the development of Internet technology,the explosive growth of Internet information presentation has led to difficulty in filtering effective information.Finding a model with high accuracy for text classification has become a critical problem to be solved by text filtering,especially for Chinese texts.This paper selected the manually calibrated Douban movie website comment data for research.First,a text filtering model based on the BP neural network has been built;Second,based on the Term Frequency-Inverse Document Frequency(TF-IDF)vector space model and the doc2vec method,the text word frequency vector and the text semantic vector were obtained respectively,and the text word frequency vector was linearly reduced by the Principal Component Analysis(PCA)method.Third,the text word frequency vector after dimensionality reduction and the text semantic vector were combined,add the text value degree,and the text synthesis vector was constructed.Experiments show that the model combined with text word frequency vector degree after dimensionality reduction,text semantic vector,and text value has reached the highest accuracy of 84.67%.

Distributed robust power control in two-tier vehicle networks under uncertain channel environments

This paper proposes a novel optimization scheme to support stable and reliable vehicle-to-everything connections in two-tier networks,where the uplink channel of the cellular user is reused by underlay vehicle-to-vehicle communications.However,considering complex channel fading and high-speed vehicle movement,the cer-tainty assumption is impractical and fails to maintain power control strategy in reality in the traditional statical vehicular networks.Rather than the perfect channel state information assumption,the first-order Gauss-Markov process which is a probabilistic model affected by vehicle speed and fading is introduced to describe imperfect channel gains.Moreover,interference management is a major challenge in reusing communications,especially in uncertain channel environments.Power control is an effective way to realize interference management,and optimal power allocation can ensure that interference of the user meets the communication requirements.In this study,the sum-rate-oriented power control scheme and minimum-rate-oriented power control scheme were implemented to manage interference and satisfy different design objectives.Since both of these schemes are non-convex and intractable,the Bernstein approximation and successive convex approximation methods were adopted to transform the original problems into convex ones.Furthermore,a novel distributed robust power control al-gorithm was developed to determine the optimal solutions.The performance of the algorithm was evaluated through numerical simulations,and the results indicate that the proposed algorithm is effective in vehicular communication networks with uncertain channel environments.

An Approach of Distributed Joint Optimization for Cluster-based Wireless Sensor Networks

Wireless sensor networks(WSNs) are energyconstrained,so energy saving is one of the most important issues in typical applications.The clustered WSN topology is considered in this paper.To achieve the balance of energy consumption and utility of network resources,we explicitly model and factor the effect of power and rate.A novel joint optimization model is proposed with the protection for cluster head.By the mean of a choice of two appropriate sub-utility functions,the distributed iterative algorithm is obtained.The convergence of the proposed iterative algorithm is proved analytically.We consider general dual decomposition method to realize variable separation and distributed computation,which is practical in large-scale sensor networks.Numerical results show that the proposed joint optimal algorithm converges to the optimal power allocation and rate transmission,and validate the performance in terms of prolonging of network lifetime and improvement of throughput.

Prediction-based protocol for mobile target tracking in wireless sensor networks

Remote tracking for mobile targets is one of the most important applications in wireless sensor networks （WSNs）. A target tracking protoco–exponential distributed predictive tracking （EDPT） is proposed. To reduce energy waste and response time, an improved predictive algorithm–exponential smoothing predictive algorithm （ESPA） is presented. With the aid of an additive proportion and differential （PD） controller, ESPA decreases the system predictive delay effectively. As a recovery mechanism, an optimal searching radius （OSR） algorithm is applied to calculate the optimal radius of the recovery zone. The simulation results validate that the proposed EDPT protocol performes better in terms of track failed ratio, energy waste ratio and enlarged sensing nodes ratio, respectively.

Resource Allocation Based on User Pairing and Subcarrier Matching for Downlink Non-Orthogonal Multiple Access Networks

The traditional orthogonal multiple access(OMA)is unable to satisfy the needs of large number of smart devices.To increase the transmission rate in the limited spectrum resource,implementation of both non-orthogonal multiple access(NOMA)and successive interference cancelation(SIC)is essential.In this paper,an optimal resource allocation algorithm in NOMA is proposed to maximize the total system rate in a multi-sector multi-subcarrier relay-assisted communication network.Since the original problem is a non-convex problem with mixed integer programming which is non-deterministic polynomial-time(NP)-hard,a three-step solution is proposed to solve the primal problem.Firstly,we determine the optimal power allocation of the outer users by using the approach of monotonic discrimination,and then the optimal user pairing is determined.Secondly,the successive convex approximation(SCA)method is introduced to transform the non-convex problem involving central users into convex one,and the Lagrangian dual method is used to determine the optimal solution.Finally,the standard Hungarian algorithm is utilized to determine the optimal subcarrier matching.The simulation results show that resource allocation algorithm is able to meet the user performance requirements with NOMA,and the total system rate is improved compared to the existing algorithms.

血清生长分化因子-15在慢性心力衰竭中的预后价值研究

目的对血清生长分化因子-15(GDF-15)在慢性心力衰竭患者临床预后中的价值进行分析。方法以我院2016年7月-2017年7月诊治的100例慢性心力衰竭患者为研究对象,并作为观察组,同时选取同期门诊100例正常患者为对照组,检测两组患者的GDF-15、氨基末端脑钠钛前体(NT-pro BNP)等,对观察组患者进行常规抗心衰治疗,比较分析血清GDF-15在慢性心力衰竭患者临床诊断中的预后价值。结果观察组患者GDF-15水平高于对照组血清GDF-15水平(P<0.05);血清GDF-15水平与NT-pro BNP水平、纽约心功能分级具有正相关(r=0.623,0.320,P<0.05);纽约心功能分级升高,血清GDF-15水平显著升高,不同分级患者GDF-15水平差异具有统计意义(P<0.05);采用ROC特征曲线分析,当GDF-15浓度为1,105.52 ng/L时,对CHF的敏感性为85.4%,特异性则为78.6%。结论血清GDF-15对慢性心力衰竭患者的预测诊断具有重要意义,可将其作为新生物标志物,对慢性心力衰竭情况进行评价。

Structure influence of alkyl chains of thienothiophene-porphyrins on the performance of organic solar cells

Two new A-D-A porphyrin derivatives,denoted as XLP-I and XLP-II,were prepared through extending theπ-conjugation of thienothiophene-porphyrin center with phenylethynyl bridges and electron-deficient ethylrhodanine terminal units,and varying the structures of alkyl chain(linear vs branched)on peripheral thienothiophene substitutions of porphyrin rings.Both molecules show strong absorption in UV–visible–near-infrared region,good thermal stability,suitable energy levels,and ordered molecular packing in solid state.In organic solar cells,PC71BM was used as electron acceptor,and porphyrin small molecules were used as electron donors.The device based on XLP-I exhibits a power conversion efficiency(PCE)of 8.30%,an open circuit voltage(Voc)of 0.894 eV,and a fill factor(FF)of 62.1%.In contrast,the device based on XLP-II presents an inferior performance with a PCE of 3.14%,a Voc of 0.847 eV,and a FF of 49.3%.The better performance of XLP-I based device is mainly attributed to its optimized film morphology,excellent absorption,and well-balanced charge transport properties.

Field distribution of the Z_(2)topological edge state revealed by cathodoluminescence nanoscopy

Photonic topological insulators with robust boundary states can enable great applications for optical communication and quantum emission,such as unidirectional waveguide and single-mode laser.However,because of the diffraction limit of light,the physical insight of topological resonance remains unexplored in detail,like the dark line that exists with the crys-talline symmetry-protected topological edge state.Here,we experimentally observe the dark line of the Z_(2)photonic topo-logical insulator in the visible range by photoluminescence and specify its location by cathodoluminescence characteriza-tion,and elucidate its mechanism with the p-d orbital electromagnetic field distribution which calculated by numerical sim-ulation.Our investigation provides a deeper understanding of Z_(2)topological edge states and may have great signific-ance to the design of future on-chip topological devices.

Quantitative Screening of Secretory Protein Genes in <i>Candidatus</i>Liberibacter Asiaticus

Huanglongbing (HLB) is the most destructive disease of citrus worldwide. The disease is caused by Candidatus Liberibacter spp., which is vectored by the psyllids Diaphorina citri Kuwayama and Trioza erytreae. Secretory proteins are important in bacterial pathogenesis and structure components. Some of them are expressed at a high level. To obtain the highly-expressed secretory protein genes (SPGs) for antiserum preparation, six candidate SPGs were chosen from Candidatus Liberibacter asiaticus by bioinformatic analysis and were further tested by qPCR and RT-qPCR methods, respectively. The result showed that two SPGs, 408 and pap (both are Flp pilus assembly protein genes), have relative high amounts of DNA and RNA transcripts of early HLB-infected green orange leaves. The 408 and pap genes were further constructed into the plant expression vector pCAMBIA1300 (GV1300: GFP) and expressed in tobacco leaf epidermal cells for subcellular localization analysis. The transient expression results indicated that the 408 protein is located in the nuclei and cytoplasm of tobacco leaf cells. However, the pap protein is located in the cytoplasm of tobacco leaf cells, which may help the pathogen invade into plant cells. This research is an important foundation for the preparation of the antiserum against Candidatus Liberibacter asiaticus and the early detection of HLB disease.

Bioinformatics Analysis of the Interaction between Coat Protein and Nuclear Shuttle Protein in <i>Babuvirus</i>

Protein and protein interactions play important roles in many biological processes and are responsible for carrying out the function of biological regulatory network in living organisms. Previous study indicated that Banana bunchy top virus (BBTV) coat protein (CP) interacted with BBTV nuclear shuttle protein (NSP). However, the protein and protein interaction and the binding affinity of CP and NSP in Babuvirus are remaining unclear. In this study, the CPs and NSPs proteins of BBTV, Abaca bunchy top virus (ABTV) and Cardamom bushy dwarf virus (CBDV) were used for bioinformatic analysis. The binding free energy and the dissociation constant of the possible interaction proteins were tested in PPA-Pred2, and the results confirmed CP interaction with NSP in Babuvirus. The study will help us to understand the interaction between viral protein and viral protein, and the pathogenesis mechanism of Babuvirus in host plants.

Antiserum Preparation and Specific Detection of Banana RING-E3 Ubiquitin-Protein Ligase

According to the data of banana transcriptome sequencing, an E3 ubiquitin-protein ligase gene was cloned by RT-PCR method using the cDNA sample of banana leaves. The complete ORF of E3 ubiquitin-protein ligase is 681 bp long and its encoded protein showed 100% sequence identity to homologue RING-H2 finger protein (XP_009407047.1) of Musa_acuminata. Bioinformatic analysis indicated that E3 ubiquitin-protein ligase contains the Ring finger domain in C terminus and eight cross-brace motifs are found in the domain. The target gene was digested by EcoR V and EcoR I, and was inserted into prokaryotic expression vector pET-32a of the same digestions to obtain the plasmid pET32a-E3 ubiquitin-protein ligase. The recombinant plasmid was introduced into Escherichia coli strain BL21 (DE3), and induced at 25°C with 0.4 mmol/L IPTG for 6 hours. The soluble fusion protein was expressed and high purity fusion protein was obtained by Ni2+-NTA agarose affinity chromatography purification. The fusion protein was injected into mice 3 times to prepare the antiserum. Western blot analysis showed a specific protein band was detected in total protein sample of banana leaves, but not for the samples of wild-type Nicotiana benthamiana (N.B.) and wild-type Arabidopsis thaliana (A.T.), implying the antiserum was specific to banana E3 ubiquitin-protein ligase.

Hydrothermal synthesis of polyimide-linked covalent organic frameworks towards ultrafast and stable cathodic sodium storage

Redox-active organic materials are capturing growing attention as cathode materials for sustainable alkaline metal ion batteries.However,the storage of Na+in most organic materials-based cathodes is plagued by low capacity and unsatisfying rate performance due to their low active site densities and limited exposed active sites.Herein,two polyimide-linked covalent organic frameworks(COFs),namely HATN-PD-COF and HATN-TAB-COF,were fabricated from hydrothermal synthesis with redoxactive triphenylene-2,3,6,7,10,11-hexacarboxylic acid and aromatic amines as starting materials.Powder X-ray diffraction and electron microscopy analysis indicate the high crystalline nature of these COFs with AA stacking configuration and orderly mesoporous tunnel.N_(2) sorption measurement discloses the permanent porosity of these two COFs with a Brunauer-EmmettTeller surface area of 1,065-1,200 m^(2)g^(-1)and a large pore size of 2.0-3.1 nm.Galvanostatic intermittent titration technique and density functional theory calculations reveal the facile Na+ion diffusion along the mesoporous tunnel of these COFs with a small energy barrier of 0.13-0.40 e V.In particular,the as-prepared COFs based-cathodes show ultrafast and stable Na+storage associated with their conjugated electronic structure,highly ordered mesoporous tunnel,robust structure,and redox-active C=N/C=O-rich framework as exemplified by the high reversible capacity of 210 m A h g^(-1)at 200 m A g^(-1),record-high rate performance(195 m A h g^(-1)at a high current density of 10,000 m A g^(-1))among organic electrodes and the capacity retention of nearly 91%at 10,000 m A g^(-1)after 7,000 cycles for HATN-PD-COF.

Metalphthalocyanine frameworks grown on TiO_(2)nanotubes for synergistically and efficiently electrocatalyzing urea production from CO_(2)and nitrate

Electrocatalytic synthesis of urea from CO_(2)and NO_(3)^(-)under ambient conditions provides an appealing alternative to the traditional energy-intensive urea synthetic protocol.Highly active and selective electrocatalysts for efficient urea production are therefore urgently desired owing to the unsatisfactory performance of the thus far reported catalysts.Herein,a phthalocyaninebased(Pc-based)covalent organic framework(COF),namely Co Pc-COF,fabricated from the nucleophilic substitution reaction of hexadecafluorophthalocyaninato cobalt with octahydroxylphthalocyanine cobalt,in situ grew on the surface of multilayered Ti O_(2)nanotubes(NTs),generating the Co Pc-COF@Ti O_(2)NTs composite.Powder X-ray diffraction analysis in combination with electron microscopy measurements discloses the uniform coating of crystalline Co Pc-COF on the multilayered Ti O_(2)NTs in Co Pc-COF@Ti O_(2)NTs.Remarkably,electrochemical tests reveal the superior electrocatalytic activity of Co Pc-COF@Ti O_(2)NTs towards urea production from CO_(2)and NO3-with a record-high yield of 1,205μg h^(-1)cm^(-2)and an outstanding Faraday efficiency of 49%at-0.6 V versus reversible hydrogen electrode due to the significant synergistic catalysis effect.In situ attenuated total reflection infrared spectroscopic investigation and theoretical calculations unveil the efficient C–N coupling reaction between*CO intermediate derived from CO_(2)on Co Pc moieties and*NH2intermediate formed from NO_(3)^(-)on Ti O_(2)NTs during the urea formation process over Co Pc-COF@Ti O_(2)NTs.This work should be helpful towards designing and fabricating high-performance electrocatalysts for sustainable synthesis of urea through efficient synergistic effect of multiactive centers.

Single-cell and spatial multi-omics in the plant sciences:Technical advances,applications,and perspectives

Plants contain a large number of cell types and exhibit complex regulatory mechanisms.Studies at the single-cell level have gradually become more common in plant science.Single-cell transcriptomics,spatial transcriptomics,and spatial metabolomics techniques have been combined to analyze plant development.These techniques have been used to study the transcriptomes and metabolomes of plant tissues at the single-cell level,enabling the systematic investigation of gene expression and metabolism in specific tissues and cell types during defined developmental stages.In this review,we present an overview of significant breakthroughs in spatial multi-omics in plants,and we discuss how these approaches may soon play essential roles in plant research.

A novel coumarin derivative DBH2 inhibits proliferation and induces apoptosis of chronic myeloid leukemia cells

With the development of tyrosine kinase inhibitor(TKI)resistance,finding the novel effective chemotherapeutic agent is of seminal importance for chronic myelogenous leukemia(CML)treatment.This study aims to find the effective anti-leukemic candidates and investigate the possible underlying mechanism.We synthesized the novel coumarin derivatives and evaluated their anti-leukemic activity.Cell viability assay revealed that compound DBH2 exhibited the potent inhibitory activity on the proliferation of CML K562 cells and TKI resistant K562 cells.Morphological observation and flow cytometry confirmed that DBH2 could selectively induce cell apoptosis and cell cycle arrest at G2/M phase of the K562 cells,which was further confirmed on the bone marrow cells from CML transgenic model mice and CD34+bone marrow leukemic cells from CML patients.Treatments of DBH2 in combination with imatinib could prolong the survival rate of SCL-tTA-BCR/ABL transgenic model mice significantly.Quantitative RT-PCR revealed that DBH2 inhibited the expression of STAT3 and STAT5 in K562 cells,and caspase-3 knockout alleviated the DBH2 induced apoptosis.Furthermore,DBH2 could induce the expression of PARP1 and ROCK1 in K562 cells,which may play the important role in caspase-dependent apoptosis.Our results concluded that coumarin derivative DBH2 serves as a promising candidate for the CML treatment,especially in the combination with imatinib for the TKI resistant CML,and STAT/caspase-3 pathway was involved in the molecular mechanism of anti-leukemic activity of DBH2.

Self-design of arbitrary polarization-control waveplates via deep neural networks

The manipulation of polarization states beyond the optical limit presents advantages in various applications.Considerable progress has been made in the design of meta-waveplates for on-demand polarization transformation,realized by numerical simulations and parameter sweep methodologies.However,due to the limited freedom in these classical strategies,particular challenges arise from the emerging requirement for multiplex optical devices and multidimensional manipulation of light,which urge for a large number of different nanostructures with great polarization control capability.Here,we demonstrate a set of self-designed arbitrary wave plates with a high polarization conversion efficiency.We combine Bayesian optimization and deep neural networks to design perfect halfand quarter-waveplates based on metallic nanostructures,which experimentally demonstrate excellent polarization control functionalities with the conversion ratios of 85%and 90%.More broadly,we develop a comprehensive wave plate database consisting of various metallic nanostructures with high polarization conversion efficiency,accompanying a flexible tuning of phase shifts(0-2π)and group delays(0-10 fs),and construct an achromatic metalens based on this database.Owing to the versatility and excellent performance,our self-designed wave plates can promote the performance of multiplexed broadband metasurfaces and find potential applications in compact optical devices and polarization division multiplexing optical communications.

Classification and Prediction of Skyrmion Material Based on Machine Learning

The discovery and study of skyrmion materials play an important role in basic frontier physics research and future information technology.The database of 196 materials,including 64 skyrmions,was established and predicted based on machine learning.A variety of intrinsic features are classified to optimize the model,and more than a dozen methods had been used to estimate the existence of skyrmion in magnetic materials,such as support vector machines,k-nearest neighbor,and ensembles of trees.It is found that magnetic materials can be more accurately divided into skyrmion and non-skyrmion classes by using the classification of electronic layer.Note that the rare earths are the key elements affecting the production of skyrmion.The accuracy and reliability of random undersampling bagged trees were 87.5%and 0.89,respectively,which have the potential to build a reliable machine learning model from small data.The existence of skyrmions in LaBaMnO is predicted by the trained model and verified by micromagnetic theory and experiments.

Global Dynamic Molecular Profiling of Stomatal Lineage Cell Development by Single-Cell RNA Sequencing

The regulation of stomatal lineage cell development has been extensively investigated.However,a comprehensive characterization of this biological process based on single-cell transcriptome analysis has not yet been reported.In this study,we performed RNA sequencing on 12844 individual cells from the cotyledons of 5-day-old Arabidopsis seedlings.We identified 11 cell clusters corresponding mostly to cells at specific stomatal developmental stages using a series of marker genes.Comparative analysis of genes with the highest variable expression among these cell clusters revealed transcriptional networks that regulate development from meristemoid mother cells to guard mother cells.Examination of the developmental dynamics of marker genes via pseudo-time analysis revealed potential interactions between these genes.Collectively,our study opens the door for understanding how the identified novel marker genes participate in the regulation of stomatal lineage cell development.

Low-noise 1.3 μm InAs/GaAs quantum dot laser monolithically grown on silicon

We report low-noise, high-performance single transverse mode 1.3 μm InAs/GaAs quantum dot lasers monolithically grown on silicon(Si) using molecular beam epitaxy. The fabricated narrow-ridge-waveguide Fabry–Perot(FP) lasers have achieved a room-temperature continuous-wave(CW) threshold current of 12.5 mA and high CW temperature tolerance up to 90°C. An ultra-low relative intensity noise of less than-150 dB∕Hz is measured in the 4–16 GHz range. Using this low-noise Si-based laser, we then demonstrate 25.6 Gb/s data transmission over13.5 km SMF-28. These low-cost FP laser devices are promising candidates to provide cost-effective solutions for use in uncooled Si photonics transmitters in inter/hyper data centers and metropolitan data links.