LIN28A/B在肿瘤发生发展中的作用研究进展

LIN28A及其同源蛋白LIN28B是高度保守的RNA结合蛋白,在胚胎早期发育、体细胞重编程、葡萄糖代谢以及肿瘤发生发展中具有重要作用。LIN28A/B在乳腺癌等恶性肿瘤中高表达,在肿瘤的起始、维持和转移中均发挥重要作用,并与预后不良相关。研究表明,LIN28A/B主要通过抑制let-7s等microRNA和直接靶向mRNA的方式发挥调控作用。本文主要综述了LIN28A/B在肝癌、乳腺癌、结直肠癌等恶性肿瘤中的功能及其分子调控机制,以期为进一步研究LIN28A/B的作用机制及其在临床治疗中的可能应用提供理论参考。

Improving the spaceborne GNSS-R altimetric precision based on the novel multilayer feedforward neural network weighted joint prediction model

Global navigation satellite system-reflection(GNSS-R)sea surface altimetry based on satellite constellation platforms has become a new research direction and inevitable trend,which can meet the altimetric precision at the global scale required for underwater navigation.At present,there are still research gaps for GNSS-R altimetry under this mode,and its altimetric capability cannot be specifically assessed.Therefore,GNSS-R satellite constellations that meet the global altimetry needs to be designed.Meanwhile,the matching precision prediction model needs to be established to quantitatively predict the GNSS-R constellation altimetric capability.Firstly,the GNSS-R constellations altimetric precision under different configuration parameters is calculated,and the mechanism of the influence of orbital altitude,orbital inclination,number of satellites and simulation period on the precision is analyzed,and a new multilayer feedforward neural network weighted joint prediction model is established.Secondly,the fit of the prediction model is verified and the performance capability of the model is tested by calculating the R2 value of the model as 0.9972 and the root mean square error(RMSE)as 0.0022,which indicates that the prediction capability of the model is excellent.Finally,using the novel multilayer feedforward neural network weighted joint prediction model,and considering the research results and realistic costs,it is proposed that when the constellation is set to an orbital altitude of 500 km,orbital inclination of 75and the number of satellites is 6,the altimetry precision can reach 0.0732 m within one year simulation period,which can meet the requirements of underwater navigation precision,and thus can provide a reference basis for subsequent research on spaceborne GNSS-R sea surface altimetry.

A Secure Device Management Scheme with Audio-Based Location Distinction in IoT

Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction techniques.In the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management system.Moreover,an audio-based location distinction method is designed to detect the position change of the devices.Specifically,the audio frequency response(AFR)of several frequency points is utilized as a device signature.The device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different directions.Based on the features above,amovement detection algorithmfor device identification and location distinction is designed.Moreover,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and Severs.Extensive experiments are conducted to evaluate the performance of the proposed method.The experimental results show that the proposedmethod has a good performance in accuracy and energy consumption.

人工智能在肛肠疾病诊治中的研究进展

过去20 a,人工智能的发展突飞猛进,其越来越多地应用于医学领域,包括医学影像辅助诊疗、健康管理、疾病风险预测等。本文基于深度学习的人工智能辅助检测和诊断系统在肛肠疾病方面的应用现状,总结当前国内外人工智能技术在肛肠疾病诊治方面相关的新方法。主要综述人工智能技术在肛瘘,肛周脓肿,痔疮等肛肠疾病诊治中的研究进展。

Multiple SiGe/Si layers epitaxy and SiGe selective etching for vertically stacked DRAM

Fifteen periods of Si/Si_(0.7)Ge_(0.3)multilayers(MLs)with various Si Ge thicknesses are grown on a 200 mm Si substrate using reduced pressure chemical vapor deposition(RPCVD).Several methods were utilized to characterize and analyze the ML structures.The high resolution transmission electron microscopy(HRTEM)results show that the ML structure with 20 nm Si_(0.7)Ge_(0.3)features the best crystal quality and no defects are observed.Stacked Si_(0.7)Ge_(0.3)ML structures etched by three different methods were carried out and compared,and the results show that they have different selectivities and morphologies.In this work,the fabrication process influences on Si/Si Ge MLs are studied and there are no significant effects on the Si layers,which are the channels in lateral gate all around field effect transistor(L-GAAFET)devices.For vertically-stacked dynamic random access memory(VS-DRAM),it is necessary to consider the dislocation caused by strain accumulation and stress release after the number of stacked layers exceeds the critical thickness.These results pave the way for the manufacture of high-performance multivertical-stacked Si nanowires,nanosheet L-GAAFETs,and DRAM devices.

A Review of the Current Task Offloading Algorithms,Strategies and Approach in Edge Computing Systems

Task offloading is an important concept for edge computing and the Internet of Things(IoT)because computationintensive tasksmust beoffloaded tomore resource-powerful remote devices.Taskoffloading has several advantages,including increased battery life,lower latency,and better application performance.A task offloading method determines whether sections of the full application should be run locally or offloaded for execution remotely.The offloading choice problem is influenced by several factors,including application properties,network conditions,hardware features,and mobility,influencing the offloading system’s operational environment.This study provides a thorough examination of current task offloading and resource allocation in edge computing,covering offloading strategies,algorithms,and factors that influence offloading.Full offloading and partial offloading strategies are the two types of offloading strategies.The algorithms for task offloading and resource allocation are then categorized into two parts:machine learning algorithms and non-machine learning algorithms.We examine and elaborate on algorithms like Supervised Learning,Unsupervised Learning,and Reinforcement Learning(RL)under machine learning.Under the non-machine learning algorithm,we elaborate on algorithms like non(convex)optimization,Lyapunov optimization,Game theory,Heuristic Algorithm,Dynamic Voltage Scaling,Gibbs Sampling,and Generalized Benders Decomposition(GBD).Finally,we highlight and discuss some research challenges and issues in edge computing.

Au^(δ-)-O_(v)-Ti^(3+):Active site of MO_(x)-Au/TiO_(2) catalysts for the aerobic oxidation of 5-hydroxymethylfurfural

Despite wide applications of noble metal-based catalysts in 5-hydroxymethylfurfural(HMF)oxidation,promoting the catalytic performance at low loading amounts still remains a significant challenge.Herein,a series of metal oxide modified MO_(x)-Au/TiO_(2)(M=Fe,Co,Ni)catalysts with low Au loading amount of 0.5 wt%were synthesized.Addition of transition metal oxides promotes electron transfer and generation of the Au^(δ-)-O_(v)-Ti^(3+)interface.A combination study reveals that the dual-active site(Au^(δ-)-O_(v)-Ti^(3+))governs the catalytic performance of the ratedetermining step,namely hydroxyl group oxidation.Au^(δ-) site facilitates chemisorption and activation of O_(2) molecules.At the same time,O_(v)-Ti^(3+) site acts as the role of“killing two birds with one stone”:enhancing adsorption of both reactants,accelerating the activation and dissociation of H_(2)O,and facilitating activation of the adsorbed O_(2).Besides,superoxide radicals instead of base is the active oxygen species during the rate-determining step.On this basis,a FDCA yield of 71.2% was achieved under base-free conditions,complying with the“green chemistry”principle.This work provides a new strategy for the transition metal oxides modification of Au-based catalysts,which would be constructive for the rational design of other heterogeneous catalysts.

Preparation and Study of Borosilicate Foam Glass with High Thermal Insulation and Mechanical Strength

Foam glass is a kind of green building material that is widely used because of its excellent thermal insulation and mechanical properties.In this study,the borosilicate foam glass was fabricated by powder sintering method using recycled soda lime waste glass,quartz,and borax as the primary raw materials.CaCO_(3)was used as a foaming agent and Na_(2)CO_(3)as a flux agent.Results showed that as the quartz content decreases from 30 to 17.5 wt.%and borax content increases from 5 to 17.5 wt.%,the pore size,porosity,and thermal insulation of borosilicate foam glass increase significantly,while the compressive strength decreases slightly.When the content of quartz and borax are both 17.5 wt.%,borosilicate foam glass with outstanding performance can be prepared,whose pore distribution is uniform,mean pore size is 1.93 mm,total porosity is 83.44%,thermal conductivity is 0.0711W/(m⋅K),and compressive strength is 2.37 MPa.Finally,the influences of foaming agent content,flux agent content,foaming temperature,and holding time on the pore structure and various properties of borosilicate foam glass were investigated by orthogonal test.According to the results,the foaming temperature has a significant effect,and appropriate foaming agent content,flux agent content,and holding time help to form a uniform pore structure,thereby improving the thermal insulation and mechanical strength of the borosilicate foam glass.

Online Markov Blanket Learning with Group Structure

Learning the Markov blanket(MB)of a given variable has received increasing attention in recent years because the MB of a variable predicts its local causal relationship with other variables.Online MB Learning can learn MB for a given variable on the fly.However,in some application scenarios,such as image analysis and spam filtering,features may arrive by groups.Existing online MB learning algorithms evaluate features individually,ignoring group structure.Motivated by this,we formulate the group MB learning with streaming features problem,and propose an Online MB learning with Group Structure algorithm,OMBGS,to identify the MB of a class variable within any feature group and under current feature space on the fly.Extensive experiments on benchmark Bayesian network datasets demonstrate that the proposed algorithm outperforms the state-of-the-art standard and online MB learning algorithms.

Hot deformation behavior of FGH96 superalloys

The hot deformation behavior of FGH96 superalloys at 1070-1170℃ and 5×10^-4-2×10^-1 s^-1 were investigated by means of the isothermal compression tests at a Gleeble-1500 thermal mechanical simulator. The results show that dynamic recovery acts as the main softening mechanism below 2×10^-3 s^-1, whereas dynamic recrystallization acts as the main softening mechanism above 2× 10^-3 s^-1 during deformation; the temperature increase caused by the deformation and the corresponding softening stress is negligible; the thermal-mechanical constitutive model to describe the hot deformation behavior is given, and the value of the apparent deformation activation energy （Qdef） is determined to be 354.93 kJ/mol.

Enabling stable sodium metal cycling by sodiophilic interphase in a polymer electrolyte system

Enabling highly reversible sodium(Na) metal anodes in a polymer electrolyte(PE) system is critical for realizing next-generation batteries with lower cost,higher energy,and improved safety.However,the uneven Na deposition and high Na/PE interphase resistance lead to poor reversibility and short cycle life of Na metal anodes.To tackle these problems,here a variety of metal nanoparticles(M-np,M=Al,Sn,In or Au) are deposited onto copper(Cu) foils to synthesize binder-free M-np@Cu substrates for Na plating/stripping.Notably,the Au-np@Cu substrate provides abundant preferential nucleation/growth sites,decreasing Na nucleation barrier and thus promoting uniform Na deposition.Accordingly,stable Na metal anodes are achieved with high reversible capacities,long cycle life,and high usage of Na.With the Au-np@Cu/Na anode and PE,the full cell using a commercial bulk sulfur cathode exhibits a reversible capacity of>400 mAh g^(-1) with near-100% Coulombic efficiency over 200 cycles.

Temporal and spatial changes in Bt toxin expression in Bt-transgenic poplar and insect resistance in field tests

Extensive planting of Bacillus thuringiensis （Bt）-transgenic plants economically benefits society; how-ever, the potential risk they pose is receiving increasing attention. This study used enzyme-linked immunosorbent assay and fluorescence quantitative PCR （RT-PCR） to monitor the temporal and spatial dynamics of the expression of Bt toxic protein in a forest of 6- to 8-year-old trees of transgenic insect-resistant poplar 741 for three consec- utive years. The enrichment, distribution, and degradation of Bt toxic protein and the influence of transgenic poplars on the targeted insect population, Hyphantria cunea, were investigated. The content of CrylAc toxic protein dynamically changed in transgenic poplar. During the annual growth cycle, the content initially increased, then decreased in the long and the short branches of the crown and in the root system, peaking in August. During the study, the protein did not accumulate overtime. The mRNA transcription of gene CrylAc was almost consistent with the level of the protein, but transcription peaked in July. In the transgenic and control forestland, microscale levels of the CrylAc toxic protein were detected from the soil, but increased accumulation was not observed with the planting year of transgenic poplar. Meanwhile, Bt was isolated and detected molecularly from the soil in the experimental forestland. A systematic investigation of the density of H. cunea in the experimental transgenic poplar forest indi- cated that transgenic Pb29 poplar could resist insects to a certain degree. At peak occurrence of the targeted insects, the density of H. cunea in the experimental forest was significantly lower than in the nontransgenic poplar forest.

New language outcome measures for Mandarin speaking children with hearing loss

Objective:The paper discusses recent evidence on the assessment of language outcomes in children with hearing loss acquiring oral language. Methods: Research emphasizes that language tests must be specific enough to capture subtle deficits in vocabulary and grammar learning at different developmental ages. The Diagnostic Receptive and Expressive Assessment of Mandarin (DREAM) was carefully designed to be a comprehensive standardized Mandarin assessment normed in China's Mainland. Results:This paper summarizes the evidence-based item design process and validity and reliability results of DREAM. A pilot study reported here shows that DREAM provided detailed information about hearing impaired children's language abilities and can be used to aid intervention planning to maximize progress. Conclusion: DREAM represents an example of translational science, transferring methods from empirical studies of language acquisition in research environments into applied domains such as assessment and intervention. Research on outcomes in China will advance significantly with the availability of evidence-based comprehensive language tests that measure a sufficient age range of skills, are normed on Mandarin speaking children in China's Mainland, and are designed to capture features central to Mandarin language acquisition.

减数分裂联会复合体异常与不孕不育相关性研究进展

减数分裂是由二倍体的生殖细胞产生单倍体的配子的过程,是有性生殖的核心。联会复合体是同源染色体之间形成的超分子结构,具有稳定同源染色体配对、促进遗传交叉形成等功能。越来越多的研究表明联会复合体异常是造成人类不孕不育的重要原因之一。本文主要综述了联会复合体中央区域异常(如SYCE1/2/3、TEX12、SIX6OS1、SYCP1突变)及侧向元件缺陷(如SYCP2、SYCP3突变)与不孕不育的相关性研究,以期为深入理解减数分裂错误导致生殖健康问题的病理机制提供理论参考。

FedCDR:Privacy-preserving federated cross-domain recommendation

Cross-Domain Recommendation(CDR)aims to solve data sparsity and cold-start problems by utilizing a relatively information-rich source domain to improve the recommendation performance of the data-sparse target domain.However,most existing approaches rely on the assumption of centralized storage of user data,which undoubtedly poses a significant risk of user privacy leakage because user data are highly privacy-sensitive.To this end,we propose a privacy-preserving Federated framework for Cross-Domain Recommendation,called FedCDR.In our method,to avoid leakage of user privacy,a general recommendation model is trained on each user's personal device to obtain embeddings of users and items,and each client uploads weights to the central server.The central server then aggregates the weights and distributes them to each client for updating.Furthermore,because the weights implicitly contain private information about the user,local differential privacy is adopted for the gradients before uploading them to the server for better protection of user privacy.To distill the relationship of user embedding between two domains,an embedding transformation mechanism is used on the server side to learn the cross-domain embedding transformation model.Extensive experiments on real-world datasets demonstrate that ourmethod achieves performance comparable with that of existing data-centralized methods and effectively protects user privacy.

Three new species of Tenthredo L. (Hymenoptera: Tenthredinidae) from China

Three new species of Tenthredo L. of Tenthredinidae are described： Tenthredo spinipulchra Wei sp. nov. from Ningxia, Gansu, Shaanxi, Hebei, Shanxi and Sichuan, T. heterostigmata Wei sp. nov. from Gansu and Shaanxi, T. maculoscapila Wei sp. nov. from Shandong and Gansu in China. The former two new species are members of Tenthredo pulchra group and the last is a member of Tenthredo stigma group. The distinguishing characteristics of above-mentioned groups are briefly discussed.

Chemokine Ligand 13 Expression is Abundant in the Tumor Microenvironment and Indicates Poor Prognosis of Kidney Clear Cell Carcinoma

The chemokine ligand 13-chemokine receptor 5(CXCL13-CXCR5)axis has been characterized as a critical tumor-promoting signaling pathway in the tumor microenvironment(TME)in multiple types of solid tumors.In this study,we analyzed the expression profile of CXCL13 in kidney clear cell carcinoma(KIRC)and its correlation with tumor-infiltrating immune cells(TIICs).A monoclonal antibody against CXCL13 with high affinity and purity was generated in our lab for western blot and immunohistochemistry(IHC).Bioinformatic analysis was performed based on bulk-seq data from the Cancer Genome Atlas(TCGA)-KIRC and single-cell RNA-seq data from scRNASeqDB and PanglaoDB.Results showed that high CXCL13 expression in TME was associated with shorter progression-free survival(PFS),disease-specific survival(DSS),and overall survival(OS).KIRC cell lines,as well as several other cancer cell lines,had negative CXCL13 expression.IHC staining from the Human Protein Atlas(HPA)and our tissue array indicated that CXCL13 might be mainly expressed by TIICs,but not KIRC tumor cells.CXCL13 expression was strongly and positively correlated withγδT cell abundance in TME.Besides,γδT cell infiltration was associated with poor survival of KIRC.Methylation 450k array data showed that CXCL13 promoter hypomethylation was common in TIICs.The methylation level of cg16361705 within the CXCL13 promoter might play an important role in modulating CXCL13 transcription.In conclusion,our study revealed that CXCL13 expression andγδT cell infiltration in TME is associated with unfavorable survival of KIRC.TIICs,most possiblyγδT cells,are the dominant source of CXCL13 in KIRC TME.

Three new species and a key to species of the Siobla grahami group(Hymenoptera:Tenthredinidae)from China

Three new species,namely Siobla dianzangica Niu&Wei sp.nov.,S.melanogaster Niu&Wei sp.nov.,and S.trilineata Niu&Wei sp.nov.,are described and illustrated.A key to species and distribution maps of the Siobla grahami group are given.

An Improved NID Steganography Method for Low Bitrate Speech on VoIP

In the procedure of encoding process on low bitrate speech,fixed codebook division is an efficient and promising embedding method for steganography.An improved neighbor index division(NID)steganography method based on the high bitrate frame of G.723.1 codec(6.3kbit/s)is proposed,which employs the parity and low distortion of neighbor indices for G.723.1 fixed codebooks.Differing from previously NID method which performs quantized index modulation(QIM)beforehand,the proposed method divides codeword indices into separate sub-codebooks according to the secret message bits dynamically in the original G.723.1 codec quantization period.Compared with existing NID method,our proposed method doesn’t need to divide the codebook before the encoding starts.The embedding and codebook dividing happen simultaneously,which utilizes the characteristics of specific secret message bits.The experiment results show that the proposed method has a much lower quality degradation for the decoding speech and still fulfills the low latency requirement for communication.

A Dynamic Steganography Method for Web Images with Average Run- Length-Coding

Web page has many redundancies,especially the dynamic html multimedia object.This paper proposes a novel method to employ the commonly used image elements on web pages.Due to the various types of image format and complexity of image contents and their position information,secret message bits could be coded to embed in these complex redundancies.Together with a specific covering code called average run-length-coding,the embedding efficiency could be reduced to a low level and the resulting capacity outperforms traditional content-based image steganography,which modifies the image data itself and causes a real image quality degradation.Our experiment result demonstrates that the proposed method has limited processing latency and high embedding capacity.What’s more,this method has a low algorithm complexity and less image quality distortion compared with existing steganography methods.