SBAS-InSAR和PS-InSAR技术在鲁西南某线性工程沿线地面沉降成因分析中的应用

地面沉降问题严重影响着鲁西南经济发展区交通工程建设。文中选择某线性工程两侧5 km范围作为研究区,文章收集RadarSAT-2(2017—2020年)、Sentinel-1A(2019—2020年)存档数据和沿线区域地质、水文地质、矿产开发资料,采用时序InSAR分析的方法,对研究区沿线地面沉降分布特征及规律进行综合分析。研究结果表明:研究区主要地面沉降诱因是煤矿采空区塌陷和地下水超量开采,前者以矿区工作面为中心形成沉降漏斗,沉降速率变化和沉降中心移动与煤矿作业工作面挖掘进度和转移密切相关;后者沉降分布规律与地下水开采使用点相关,形成与地下水开采使用范围相近的沉降带。研究区在2017—2020年内持续发生沉降,最大年均沉降速率为136.5 mm/a,单年累计最大沉降量为220 mm。经同期CPI水准点观测结果校核,InSAR数据处理成果平均误差小于1 cm/a,相关系数到达70%以上。本文采用的分析方法能及时准确反映出线路方案穿行研究区内各处地面沉降变化,为线路方案规划和地质灾害整治提供有效合理参考。

Cipherchain:A Secure and Efficient Ciphertext Blockchain via mPECK

Most existing blockchain schemes are based on the design concept“openness and transparency”to realize data security,which usually require transaction data to be presented in the form of plaintext.However,it inevitably brings the issues with respect to data privacy and operating performance.In this paper,we proposed a novel blockchain scheme called Cipherchain,which can process and maintain transaction data in the form of ciphertext while the characteristics of immutability and auditability are guaranteed.Specifically in our scheme,transactions can be encrypted locally based on a searchable encryption scheme called multi-user public key encryption with conjunctive keyword search(mPECK),and can be accessed by multiple specific participants after appended to the globally consistent distributed ledger.By introducing execution-consensus-update paradigm of transaction flow,Cipherchain cannot only make it possible for transaction data to exist in the form of ciphertext,but also guarantee the overall system performance not greatly affected by cryptographic operations and other local execution work.In addition,Cipherchain is a promising scheme to realize the technology combination of“blockchain+cloud computing”and“permissioned blockchain+public blockchain”.

Carrier-free programmed spherical nucleic acid for effective ischemic stroke therapy via self-delivery antisense oligonucleotide

Antisense oligonucleotide(ASO)for anti-apoptosis is emerging as a highly promising therapeutic agents for ischemic stroke with complex pathological environment.However,its therapeutic efficacy is seriously limited by a number of challenges including inefficient internalization,low blood-brain barrier(BBB)penetration,poor stability,and potential toxicity of the carrier.Herein,a carrier-free programmed spherical nucleic acid nanostructure is developed for effective ischemic stroke therapy via integrating multifunctional modules into one DNA structure.By co-encoding caspase-3-ASO and transferrin receptor(TfR)aptamer into circle template,the spherical nucleic acid nanostructure(TD)was obtained via self-assembly.The experimental results demonstrated that the developed TD displayed efficient BBB penetration capability(6.4 times)and satisfactory caspase-3 silence effect(2.3 times)due to the dense DNA packaging in TD.Taken together,our study demonstrated that the carrier-free programmed spherical nucleic acid nanostructure could significantly improve the therapeutic efficacy of ischemic stroke and was a promising therapeutic tool for various brain damage-related diseases.

BSFbase:The comprehensive genomic resource for a natural recycler,the black soldier fly(Hermetia illucens L.)

Dear Editor,Economic and population growth increasingly consume resources from the environment and present a major challenge regarding the management of waste.The demand for insects as a resource is increasing,as they have the potential to aid in waste recycling and alleviate shortages of natural resources(Ojha et al.,2020).The black soldier fly(BSE,Hermetia illucens L.)is a species native to tropical and subtropical parts of the Americas.

棉粕对盐碱胁迫下棉花生理及生长补偿效应

为探究棉粕对盐碱胁迫下棉花(Gossypiumhirsutum)的抗盐碱机理,通过田间试验,研究添加不同棉粕用量对8g·kg^(–1)盐碱胁迫下棉花生理及生长的补偿效应。结果表明,添加棉粕能够增加盐碱胁迫下棉花不同器官对K^+的吸收,降低对Na^+的吸收,维持盐碱胁迫下细胞内K^+和Na^+的平衡,显著促进棉花生长,提高叶片叶绿素含量和光合作用效率,有效缓解盐碱胁迫对棉花的伤害。其中,以添加6 000 kg·hm^(–2)棉粕处理的效果最显著,且盐胁迫下棉粕的改良效果较好。主成分分析结果表明,盐碱胁迫下棉花生长生理的主要影响因子为叶片K^+/Na^+比值、根长、鲜重、干重和胞间CO_2浓度(C_i)。

Boosting 5-ALA-based photodynamic therapy by a liposomal nanomedicine through intracellular iron ion regulation

5-Aminolevulinic acid(5-ALA)has been approved for clinical photodynamic therapy(PDT)due to its negligible photosensitive toxicity.However,the curative effect of 5-ALA is restricted by intracellular biotransformation inactivation of 5-ALA and potential DNA repair of tumor cells.Inspired by the crucial function of iron ions in 5-ALA transformation and DNA repair,a liposomal nanomedicine(MFLs@5-ALA/DFO)with intracellular iron ion regulation property was developed for boosting the PDT of 5-ALA,which was prepared by co-encapsulating 5-ALA and DFO(deferoxamine,a special iron chelator)into the membrane fusion liposomes(MFLs).MFLs@5-ALA/DFO showed an improved pharmaceutical behavior and rapidly fused with tumor cell membrane for 5-ALA and DFO co-delivery.MFLs@5-ALA/DFO could efficiently reduce iron ion,thus blocking the biotransformation of photosensitive protoporphyrin IX(Pp IX)to heme,realizing significant accumulation of photosensitivity.Meanwhile,the activity of DNA repair enzyme was also inhibited with the reduction of iron ion,resulting in the aggravated DNA damage in tumor cells.Our findings showed MFLs@5-ALA/DFO had potential to be applied for enhanced PDT of 5-ALA.

Construction of Nanocarriers Based on Endogenous Cell Membrane and Their Application in Nanomedicine

Inspired by the adaptation of cells to the surrounding environment,the combination of cell membrane and nanomaterials has gradually become a new type of biomimetic nanocomposite.The construction of endogenous membrane biomimetic nanocarriers(EMBNs)not only retains the structure of membrane surface protein,but also has the properties of nanoparticles(NPs),also provides the ability of natural interaction between nanomaterials and organisms,thus overcoming the severe challenges faced by traditional nanodelivery systems in clinical application.In this paper,the construction methods of EMBNs are reviewed,focusing on a simple method to prepare membrane proteins.Secondly,EMBNs were classified according a variety of cell membranes.Finally,the unique advantages of EMBNs in nanomedicine are introduced,including improving biocompatibility,homologous targeting ability,prolonging blood circulation time and immune escape abilty.In nanomedicine,such as targeted delivery,phototherapy,immunotherapy and tumor imaging,multifaceted biological interfaces through membrane masking provide a new approach for the development of multifunctional NPs.

Y-Shaped Circular Aptamer–DNAzyme Conjugates for Highly Efficient in Vivo Gene Silencing

Oligonucleotide drugs have been used widely as therapeutic agents for gene therapy,while their instability in biological media and inefficiency for intracellular delivery remain major hurdles for practical in vivo applications.Herein,we report a circular Y-shaped aptamer–DNAzyme conjugate(cYAD)for highly efficient in vivo gene silencing via RNA cleavage,which can been employed in various disease treatments,including cancer,inflammation,as well as viral infections.Systematic studies revealed that cyclization of the DNA structure could improve the stability of oligonucleotide drugs in vivo.Besides,the bivalent aptamer motifs provided a specific and enhanced tumor cell targeting ability for accumulation and retention of the oligonucleotide drugs at the tumor site.As a proof of concept,a widely applicable Na+-dependent fluorescent sensor,NaA43 DNAzyme,was used to inhibit MET gene expression in mice tumor model tissues,which exhibited highly efficient gene silencing performance in vivo,which confirmed our findings with cYAD.This strategy provides a novel approach for the construction of oligonucleotide drugs for practical therapeutic applications.