Incident analyses of frost heaving failure of municipal underground gas pipelines in cold regions of northern China

In the cold regions of northern China, incidents of municipal underground gas pipeline rupture and leakage occur quite fi-equently, aaost often in winter. To prevent harm to citizen safety and property, analysis of the causes of such cracking and leakage is therefore valuable. Two incident analyses are discussed here and the reasons why most of these types of cases occur dttring winter are clarified. Fhe effects of vehicle loadings above buried pipelines are calculated and compared with the effects and calculations of frost heaving forces. We demonstrate thtit when the soil layer above a pipeline freezes rapidly, the soil generates repeated frost heaving, which exerts heaving forces on the pipeline that can result in fatigue crack propagation and ultimate pipeline failure. Therefore, the incident induced 9y frost heaving is one of the primary reasons of gas pipeline failure. Based on these analyses, we present some recommendations pertaining to the proper design, construction, and management of gas pipelines.

植入式光电极器件发展

光遗传技术为神经科学研究提供了一种可精准、快速控制单个神经元活动的手段。为了对神经元实现光遗传调控,将光安全、高效地导入脑内,需要专门的光电极(Optrode)给予支持。光电极是光遗传工具应用的重要组成部分,其功能是把光导入脑内调控神经元活动,同时记录神经元电信号在光调控下变化情况的一种植入式神经接口器件。随着光遗传技术在神经环路、认知与记忆等神经科学研究中应用的深入,以及其在癫痫、感官功能损伤等疾病治疗方面的探索,与光遗传技术相配合的光电极从材料选择、器件结构、给光方式和集成工艺等方面都呈现出百花齐放的发展态势,本文将按照现有植入式光电极的结构特点,将光电极器件分成基于波导型和基于微发光二极管型两大类,论述不同类别光电极器件优缺点及演进方向,对未来植入式光电极的理想结构形态及亟待解决的问题进行了讨论和展望。

Topic Controlled Steganography via Graph-to-Text Generation

Generation-based linguistic steganography is a popular research area of information hiding.The text generative steganographic method based on conditional probability coding is the direction that researchers have recently paid attention to.However,in the course of our experiment,we found that the secret information hiding in the text tends to destroy the statistical distribution characteristics of the original text,which indicates that this method has the problem of the obvious reduction of text quality when the embedding rate increases,and that the topic of generated texts is uncontrollable,so there is still room for improvement in concealment.In this paper,we propose a topic-controlled steganography method which is guided by graph-to-text generation.The proposed model can automatically generate steganographic texts carrying secret messages from knowledge graphs,and the topic of the generated texts is controllable.We also provide a graph path coding method with corresponding detailed algorithms for graph-to-text generation.Different from traditional linguistic steganography methods,we encode the secret information during graph path coding rather than using conditional probability.We test our method in different aspects and compare it with other text generative steganographic methods.The experimental results show that the model proposed in this paper can effectively improve the quality of the generated text and significantly improve the concealment of steganographic text.

Tailoring combinatorial lipid nanoparticles for intracellular delivery of nucleic acids, proteins,and drugs

Lipid nanoparticle(LNP)-based drug delivery systems have become the most clinically advanced non-viral delivery technology.LNPs can encapsulate and deliver a wide variety of bioactive agents,including the small molecule drugs,proteins and peptides,and nucleic acids.However,as the physicochemical properties of small-and macromolecular cargos can vary drastically,every LNP carrier system needs to be carefully tailored in order to deliver the cargo molecules in a safe and efficient manner.Our group applied the combinatorial library synthesis approach and in vitro and in vivo screening strategy for the development of LNP delivery systems for drug delivery.In this Review,we highlight our recent progress in the design,synthesis,characterization,evaluation,and optimization of combinatorial LNPs with novel structures and properties for the delivery of small-and macromolecular therapeutics both in vitro and in vivo.These delivery systems have enormous potentials for cancer therapy,antimicrobial applications,gene silencing,genome editing,and more.We also discuss the key challenges to the mechanistic study and clinical translation of new LNP-enabled therapeutics.

Study the lipidoid nanoparticle mediated genome editing protein delivery using 3D intestinal tissue model

Lipid nanoparticles are promising carriers for oral drug delivery.For bioactive cargos with intracellular targets,e.g.gene-editing proteins,it is essential for the cargo and carrier to remain complexed after crossing the epithelial layer of intestine in order for the delivery system to transport the cargos inside targeted cells.However,limited studies have been conducted to verify the integrity of cargo/carrier nanocomplexes and their capability in facilitating cargo delivery intracellularly after the nanocomplex crossing the epithelial barrier.Herein,we used a traditional 2D transwell system and a recently developed 3D tissue engineered intestine model and demonstrated the synthetic lipid nanoparticle(carrier)and protein(cargo)nanocomplexes are able to cross the epithelial layer and deliver the protein cargo inside the underneath cells.We found that the EC16-63 LNP efficiently encapsulated the GFP-Cre recombinase,penetrated the intestinal monolayer cells in both the 2D cell culture and 3D tissue models through temporarily interrupting the tight junctions between epithelial layer.After transporting across the intestinal epithelia,the EC16-63 and GFP-Cre recombinase nanocomplexes can enter the underneath cells to induce gene recombination.These results suggest that the in vitro 3D intestinal tissue model is useful for identifying effective lipid nanoparticles for potential oral drug delivery.

Traditional Chinese medicine for age-related macular degeneration: A clinical evidence map between 2000 and 2022

Background:We systematically searched and summarized clinical studies on traditional Chinese medicine(TCM)for age-relatedmacular degeneration(AMD)with the method of evidence map.We aimed to provide evidence and research direction for the prevention or treatment of AMD with TCM in the future.Materials and methods:We searched PubMed,Web of Science,EMBASE,and Chinese databases including CNKI(Chinese National Knowledge Infrastructure),WanFang and VIP,ClinicalTrials.gov,and ChineseClinical Trial Registry Center studies on the prevention or treatment of TCMfor AMD from January 2000 to November 2022.We showed distribution features of these studies in the form of text description,graphs,and tables.Results:The final 258 articles included 245 clinical studies,9 systematic reviews ormeta-analyses,and 4 guidelines,expert consensus,or clinical pathway.After analyzing the articles with a focus on the stage of AMD,study type,sample size,intervention measures,outcome indicators,and the quality of evidence,we found that the studies were increasing,most of which were wet AMD,the main study type was randomized controlled trials,and the sample size was mostly fewer than 100 cases.Different interventions of TCM,such as Chinese medicine,Chinese patentmedicine,or acupuncture,showed the potential benefits of improving vision,reducing fundus lesions,and alleviating some uncomfortable symptoms.However,the sample size of these studies was small.The outcome indicators were not unified,and the stage of AMD was unclear.The quality of articles was lower,and there were few studies on early AMD.The advantages of TCM for the prevention or treatment of AMD remained unclear.Conclusions:Early intervention will be the focus and direction of AMD in the prevention or treatment of TCM,and more standardized clinical studies of TCM for early AMD need to be designed and carried out in the future.

A Simple Synthesis of Tetraamino-[60]Fullerene Epoxides as Potential Antitumor Drug Candidates

Amphiphilic aminated fullerenes have a broad margin of safety and significant antitumor effects.Herein,we develop a simple and versatile synthesis strategy for tetraamino-[60]fullerene epoxide(C_(60)(NR^(1)R^(2))_(4)O)using C_(60)Cl_(6)as a precursor,which notably reduces the reaction time to less than 1 h while retaining a high yield of over 80%with both cyclic and linear secondary amine substrates even at the gram level.The molecular structure of C_(60)(NR^(1)R^(2))_(4)O is first validated by single-crystal diffraction,and a two-step reaction mechanism comprising nucleophilic substitution of Cl and the oxidative elimination of Cl_(2)is proposed based on experimental verification and density functional theory simulation.A set of water-soluble aminated C_(60)(NR^(1)R^(2))_(4)O was prepared in large quantities,and in vitro antitumor evaluation unveiled the critical role that terminal primary amino moieties of C_(60)(NR^(1)R^(2))_(4)O play in their antineoplastic effects.This work provides an effective synthesis method for aminated C_(60)(NR^(1)R^(2))_(4)O,facilitating the development of fullerene-derived tumor-targeted drugs.

Incorporating redox-sensitive nanogels into bioabsorbable nanofibrous membrane to acquire ROS-balance capacity for skin regeneration

Facing the high incidence of skin diseases,it is urgent to develop functional materials with high bioactivity for wound healing,where reactive oxygen species(ROS)play an important role in the wound healing process mainly via adjustment of immune response and neovasculation.In this study,we developed a kind of bioabsorbable materials with ROS-mediation capacity for skin disease therapy.Firstly,redox-sensitive poly(N-isopropylacrylamide-acrylic acid)(PNA)nanogels were synthesized by radical emulsion polymerization method using a disulfide molecule as crosslinker.The resulting nanogels were then incorporated into the nanofibrous membrane of poly(L-lactic acid)(PLLA)via airbrushing approach to offer bioabsorbable membrane with redox-sensitive ROS-balance capacity.In vitro biological evaluation indicated that the PNA-contained bioabsorbable membrane improved cell adhesion and proliferation compared to the native PLLA membrane.In vivo study using mouse wound skin model demonstrated that PNA-doped nanofibrous membranes could promote the wound healing process,where the disulfide bonds in them were able to adjust the ROS level in the wound skin for mediation of redox potential to achieve higher wound healing efficacy.

陈运泰:中国科技期刊的发展离不开科学家的参与和奉献

陈运泰,地球物理学家,1940年出生于厦门,1962年毕业于北京大学地球物理系, 1966年(研究生)毕业于中国科学院地球物理研究所.中国科学院大学荣誉讲席教授,中国科学院院士,发展中国家科学院院士,研究成果获多项国际、国家奖励.在中国科技期刊国际影响力提升计划、登峰行动计划、卓越行动计划等项目中担任评委或监察委员,1988~2012年担任《中国科学》《科学通报》(以下简称"两刊")联合编委会编委,长期关注中国科技期刊特别是"两刊"的发展.