Securing Forwarding Layers from Eavesdropping Attacks Using Proactive Approaches

As an emerging network paradigm,the software-defined network(SDN)finds extensive application in areas such as smart grids,the Internet of Things(IoT),and edge computing.The forwarding layer in software-defined networks is susceptible to eavesdropping attacks.Route hopping is amoving target defense(MTD)technology that is frequently employed to resist eavesdropping attacks.In the traditional route hopping technology,both request and reply packets use the same hopping path.If an eavesdropping attacker monitors the nodes along this path,the risk of 100%data leakage becomes substantial.In this paper,we present an effective route hopping approach,called two-day different path(TDP),that turns communication paths into untraceable moving targets.This technology minimizes the probability of data leakage by transmitting request data and reply data through different paths.Firstly,a brief introduction to the network model and attack model involved in this paper is given.Secondly,the algorithm and processingmethod of the TDP are proposed.Thirdly,the paper proposes three differentmetrics tomeasure the effectiveness of the proposed approach.Finally,theoretical analysis and simulation results show that the TDP can effectively reduce the percentage of data exposure,decrease eavesdropping attack success probability,and improve the unpredictability of the path.

Inhibition of proliferation,migration,and invasiveness of bladder cancer cells through SAPCD2 knockdown

Introduction:Bladder cancer(BC)has a high incidence and mortality rate worldwide.Suppressor anaphasepromoting complex domain containing 2(SAPCDC2)is over-expressed in a variety of tumors.Objectives:This study investigated the effects of SAPCD2 knockdown on BC cells.Methods:T24 and UMUC3 cell models and the xenografted BC tumor model with SAPCD2 knockdown were established to observe the malignant phenotype of BC cells by cell counting kit-8 assay,colony formation test,wound healing,and Transwell assay,mRNA and proteins expressions were measured with quantitative real-time polymerase chain reaction,western blotting,and tissue immunohistochemistry.Lithium chloride agonist on the Wnt/β-catenin pathway was used to clarify the molecular mechanism of SAPCD2 knockdown.Results:SAPCD2 expression was significantly higher in BC cell lines than in SVHUC-1 cells.SAPCD2 knockdown inhibited viability and cloning,hindered the G0/G1 phase of the cell cycle in UMUC3 and T24 cells,and decreased the migration and invasiveness of BC cells.SAPCD2 knockdown inhibited expression levels of cyclin D1,cyclin B1,N-cadherin,vimentin,Snail,β-catenin,c-Myc,and cyclin-dependent kinase 4,while the P21 and E-cadherin were raised by SAPCD2 knockdown.Furthermore,lithium chloride reversed the effects of SAPCD2 knockdown on the expression levels of the above proteins in UMUC3 and T24 cells.In vivo,SAPCD2 knockdown inhibited the volume,weight,and expression of Ki-67 andβ-catenin in tumors and increased the E-cadherin expression.Conclusion:SAPCD2 knockdown inhibits the malignant phenotype of BC via a pathway involvingβ-catenin.

Glycerol solutions of highly concentrated biomineral counter-ions towards water-responsive mineralization: Demonstration on bacterial cellulose and its application in hard tissue repair

Mineralization has found widespread use in the fabrication of composite biomaterials for hard tissue regeneration.The current mineralization processes are mainly carried out in neutral aqueous solutions of biomineral counter-ions(a pair of cation and anion that form the corresponding minerals at certain conditions),which are stable only at very low concentrations.This typically results in inefficient mineralization and weak control over biomineral formation.Here,we find that,in the organic solvent glycerol,a variety of biomineral counter-ions(e.g.,Ca/PO_(4),Ca/CO_(3),Ca/SO_(4),Mg/PO_(4),or Fe/OH)corresponding to distinct biominerals at significantly high concentrations(up to hundreds-fold greater than those of simulated body fluid(SBF))are able to form translucent and stable solutions(mineralizing solution of highly concentrated counter-ions(MSCIs)),and mineralization can be triggered upon them with external solvents(e.g.,water or ethanol).Furthermore,with pristine bacterial cellulose(BC)membrane as a model,we demonstrate an effective and controllable mineralization performance of MSCIs on organic substrates.This approach not only forms the homogeneous biominerals on the BC fibers and in the interspaces,but also provides regulations over mineralization rate,mineral content,phase,and dopants.The resulting mineralized BC membranes(MBCs)exhibit high cytocompatibility and favor the proliferation of rat bone marrow mesenchymal stem cells(rBMSC).Following this,we prepare a mineralized bone suture(MBS)from MBC for non-weight bearing bone fixation,which then is tested on a rabbit median sternotomy model.It shows firm fixation of the rabbit sternum without causing discernible toxicity or inflammatory response.This study,by extending the mineralization to the organic solution system of highly concentrated counter-ions,develops a promising strategy to design and build targeted mineral-based composites.

我国乡土草选育的现状、关键科学问题及发展方向

乡土草是重要的草类植物种质资源,具有抗逆性强、适应性广、类型多样等特性。可经过人工栽培和驯化选育为草类植物新品种,也可利用其优异基因资源,创制和改良现有的牧草品种。乡土草是我国畜牧业发展和生态修复的重要物质基础,但目前我国乡土草品种匮乏、种子产量低,已成为制约草种业发展的“卡脖子”问题。本文从三个方面综述了我国乡土草育种现状:(1)我国乡土草资源丰富,但亟待加强收集、保存与利用;(2)我国具有自主知识产权的乡土草品种匮乏;(3)乡土草驯化选育以常规育种为主,分子育种发展滞后。基于研究现状和发展前沿笔者认为未来应重点关注:(1)乡土草抗逆(抗寒、抗旱、抗盐碱)、高产(草产量、种子产量、落粒、裂荚、开花期等)、优质(粗蛋白含量、香豆素含量、消化率等)性状的精准鉴定;(2)乡土草抗逆、落粒、休眠、萌发、结实率等重要农艺性状形成的分子机理和调控网络;(3)乡土草新品种与土壤、家畜和微生物的互作机制等关键科学问题。围绕以上科学问题开展乡土草抗逆、高产和优质等性状形成的生物学基础研究并建立现代高效育种和繁育技术体系有助于加速选育具有我国自主知识产权的乡土草新品种,促进其推广应用,攻克草种业“卡脖子”问题,保障国家的食物安全和生态安全。

基因枪介导的老芒麦遗传转化体系的建立

川草2号老芒麦(Elymus sibiricus)是青藏高原地区治理荒漠化和建设高产人工草地的主要栽培草种。用川草2号老芒麦5种外植体诱导愈伤组织,经分化测试,仅幼穗愈伤组织能分化再生。以当代培养25天和35天的结构致密坚硬的幼穗愈伤组织为受体,分别进行农杆菌侵染和基因枪转化,结果只有基因枪能转化成功。在基因枪转化过程中,采用高渗培养和滤纸干燥2种方式预处理愈伤组织,结果表明滤纸干燥处理比高渗处理转化效率高。当代诱导25天的幼穗愈伤组织,滤纸干燥处理2小时转化效率最高,达40%。该研究成功获得了基因枪转化的以川草2号老芒麦幼穗愈伤为受体的阳性愈伤组织。