Neutron Diffraction Study on the Magnetic Structure of 153EuMnO3-δ: One Way to Assess the Magnetic Structure of EuMnO3-δ

Owing to the strong neutron absorption of 151Eu,151Eu free 153EuMnO3-δhas been synthesized to collect the neutron diffraction data for analyzing the magnetic structure of EuMnO3-δ.The obtained neutron diffraction data of 153EuMnO3-δindicates that the magnetic diffraction peaks corresponding to cAAFM(canted A-type antiferromagnetic)phase can be observed,but the magnetic diffraction peaks corresponding to expected ICAFM(incommensurate antiferromagnetic)phase may be too weak to be observed.

Distance protection of EHV long transmission lines considering compensation degree of shunt reactor

This study investigated the feasibility of distance protection in extra-high voltage(EHV) networks. In long-distance transmission lines, the distributed parameter characteristic of the EHV network is obvious. When a fault occurs far away from the measurement site, the measured impedance might not be directly proportional to the fault distance, and the protection domain of distance protection will be decreased. The detailed theory inferred and proven in this paper reveals that this phenomenon is widespread in EHV transmission lines. The results indicate that the protection domain error is greatly reduced by the application of the shunt reactor. Overall, simulation results show that the proposed method is effective for impedance relay, considering different characteristics, different lengths of lines, and compensation degrees.

Local buckling of thin plate on tensionless elastic foundations under interactive uniaxial compression and shear

This paper uses a mathematical method to develop an analytical solution to the local buckling behaviour of long rectangular plates resting on tensionless elastic Winkler foundations and under combined uniform longitudinal uniaxial compressive and uniform in-plane shear loads. Fitted formulas are derived for plates with clamped edges and simplified supported edges. Two examples are given to demonstrate the application of the current method： one is a plate on tensionless spring foundations and the other is the contact between the steel sheet and elastic solid foundation. Finite element （FE） analysis is also conducted to validate the analytical results. Good agreement is obtained between the current method and FE analysis.

Gallium-based liquid metal micro/nanoparticles for photothermal cancer therapy

Gallium-based liquid metals have attracted significant interest in the biomedical field due to their unique properties such as low viscosity,good fluidity,high thermal/electrical conductivity,and good biocompatibility.Meanwhile,photothermal therapy has made great development in the field of antitumor with its advantages of low adverse effects,high specificity,and repeatable treatment.The photothermal capability possessed by gallium-based liquid metals makes them show unparalleled advantages in photothermal therapy.Liquid metal-based photothermal therapy has progressed in recent years and can perform a vital role in accurate and noninvasive antitumor therapy.Herein,a review of the major preparation methods of liquid metal micro/nanoparticles,the mechanism of liquid metal photothermal conversion,and discussions on the factors affecting the photothermal properties of liquid metals are presented.The biological applications of liquid metal photothermal therapy in synergy with other therapies are discussed,as well as the current challenges and opportunities for the clinical translation of liquid metals in biomedical applications.

基于MaxEnt模型分析广东省鸟类多样性热点分布及保护空缺

随着环境问题日益突出,生物多样性也面临着挑战。广东省丰富的水土资源孕育了大量的生物物种,然而快速的城市扩张又对生物多样性的保护带来了一定的压力。明确广东省生物多样性保护空缺,以便在未来城市规划布局中更好地实施保护,缓解城市发展与生态保护之间的矛盾。空间分布格局是生物多样性保护规划的基础,本文以全国第二次陆生野生动物资源调查鸟类数据为基础,基于MaxEnt模型进行空间化(空间分辨率为100 m×100 m),通过识别热点地区,并与现有国土规划中三条管控线对比,识别保护空缺。本文主要有以下结果:(1)广东省建模鸟类共有13目45科173种,其空间丰富度格局主要呈三片区分布:(1)南岭片区;(2)粤东片区;(3)江门、阳江、云浮片区;(2)影响鸟类空间格局的环境因子在不同物种间差异明显,总体来看土地利用类型、高程、年均温度差等因素占主导地位;(3)保护鸟类与全部鸟类的热点地区分布相似,但空间上更为聚集,两者的空间重叠率达63.0%,主要分布于南岭片区、粤东片区;(4)留鸟类和迁徙鸟类的热点地区存在明显空间差异,重叠区域仅25.3%,留鸟类分布相对靠北而迁徙鸟类相对趋南;(5)鸟类热点分区统计对比中,与永久基本农田的重叠率明显高于生态保护红线,极少量分布于城镇开发边界内部,全部鸟类、保护鸟类、留鸟类、迁徙鸟类均存在明显的保护空缺。本研究得到了精细尺度下鸟类多样性空间分布格局与保护空缺结果,为城镇开发边界、永久基本农田、生态保护红线三条控制线内的生物多样性分区保护、管控政策实施提供了有效支撑,为广东省的生物多样性保护、生态规划调整提供了有益参考。

Performance enhancement of paper-based SERS chips by shell-isolated nanoparticle-enhanced Raman spectroscopy

Paper-based flexible surface-enhanced Raman scattering(SERS) chips have been demonstrated to have great potential for future practical applications in point-of-care testing(POCT) due to the potentials of massive fabrication, low cost, efficient sample collection and short signal acquisition time. In this work,common filter paper and Ag@Si O2 core-shell nanoparticles(NP) have been utilized to fabricate SERS chips based on shell-isolated nanoparticle-enhanced Raman spectroscopy(SHINERS). The SERS performance of the chips for POCT applications was systematically investigated. We used crystal violet as the model molecule to study the influence of the size of the Ag core and the thickness of the Si O2 coating layer on the SERS activity and then the morphology optimized Ag@Si O2 core-shell NPs was employed to detect thiram. By utilizing the smartphone as a miniaturized Raman spectral analyzer, high SERS sensitivity of thiram with a detection limit of 10^-9 M was obtained. The study on the stability of the SERS chips shows that a Si O2 shell of 3 nm can effectively protect the as-prepared SERS chips against oxidation in ambient atmosphere without seriously weakening the SERS sensitivity. Our results indicated that the SERS chips by SHINERS had great potential of practical application, such as pesticide residues detection in POCT.

Serum macrophage migration inhibitory factor as a potential biomarker to evaluate therapeutic response in patients with allergic asthma:an exploratory study

Background:Previous studies have shown that macrophage migration inhibitory factor(MIF)is involved in the pathogenesis of asthma.This study aimed to investigate whether serum MIF reflects a therapeutic response in allergic asthma.Methods:We enrolled 30 asthmatic patients with mild-to-moderate exacerbations and 20 healthy controls,analyzing the parameter levels of serum MIF,serum total immunoglobulin E(tIgE),peripheral blood eosinophil percentage(EOS%),and fractional exhaled nitric oxide(FeNO).Lung function indices were used to identify disease severity and therapeutic response.Results:Our study showed that all measured parameters in patients were at higher levels than those of controls.After one week of treatment,most parameter levels decreased significantly except for serum tIgE.Furthermore,we found that serum MIF positively correlated with EOS%as well as FeNO,but negatively correlated with lung function indices.Receiver operator characteristic(ROC)curve analysis indicated that among the parameters,serum MIF exhibited a higher capacity to evaluate therapeutic response.The area under the curve(AUC)of MIF was 0.931,with a sensitivity of 0.967 and a specificity of 0.800.Conclusions:Our results suggested that serum MIF may serve as a potential biomarker for evaluating therapeutic response in allergic asthma with mild-to-moderate exacerbations.

Liquid Metal-Based Epidermal Flexible Sensor for Wireless Breath Monitoring and Diagnosis Enabled by Highly Sensitive SnS2 Nanosheets

Real-time wireless respiratory monitoring and biomarker analysis provide an attractive vision for noninvasive telemedicine such as the timely prevention of respiratory arrest or for early diagnoses of chronic diseases.Lightweight,wearable respiratory sensors are in high demand as they meet the requirement of portability in digital healthcare management.Meanwhile,high-performance sensing material plays a crucial role for the precise sensing of specific markers in exhaled air,which represents a complex and rather humid environment.Here,we present a liquid metal-based flexible electrode coupled with SnS_(2)nanomaterials as a wearable gas-sensing device,with added Bluetooth capabilities for remote respiratory monitoring and diagnoses.The flexible epidermal device exhibits superior skin compatibility and high responsiveness(1092%/ppm),ultralow detection limits(1.32 ppb),and a good selectivity of NO gas at ppb-level concentrations.Taking advantage of the fast recovery kinetics of SnS_(2)responding to H_(2)O molecules,it is possible to accurately distinguish between different respiratory patterns based on the amount of water vapor in the exhaled air.Furthermore,based on the different redox types of H_(2)O and NO molecules,the electric signal is reversed once the exhaled NO concentration exceeds a certain threshold that may indicate the onset of conditions like asthma,thus providing an early warning system for potential lung diseases.Finally,by integrating the wearable device into a wireless cloud-based multichannel interface,we provide a proof-of-concept that our device could be used for the simultaneous remote monitoring of several patients with respiratory diseases,a crucial field in future digital healthcare management.

Modification of alternative splicing in bovine somatic cell nuclear transfer embryos using engineered CRISPR-Cas13d

Animal cloning can be achieved by somatic cell nuclear transfer(SCNT),but the resulting live birth rate is relatively low.We previously improved the efficiency of bovine SCNT by exogenous melatonin treatment or by overexpression of lysine-specific demethylase 4D(KDM4D)and 4E(KDM4E).In this study,we revealed abundant alternative splicing(AS)transitions during fertilization and embryonic genome activation,and demonstrated abnormal AS in bovine SCNT embryos compared with in vitro fertilized embryos.We used the CRISPR-Cas13d RNA-targeting system to target cis-elements of ABI2 and ZNF106 pre-m RNA to modify AS,thus reducing the ratio of abnormal-isoform SCNT embryos by nearly 50%and achieving a high survival rate(11%–19%).These results indicate that this system may provide an efficient method for bovine cloning,while also paving the way for further improvements in the efficiency of SCNT.

Magnetic Nanomotor-Based Maneuverable SERS Probe

Surface-enhanced Raman spectroscopy(SERS)is a powerful sensing technique capable of capturing ultrasensitive fingerprint signal of analytes with extremely low concentration.However,conventional SERS probes are passive nanoparticles which are usually massively applied for biochemical sensing,lacking controllability and adaptability for precise and targeted sensing at a small scale.Herein,we report a“rod-like”magnetic nanomotor-based SERS probe(MNM-SP)that integrates a mobile and controllable platform of micro-/nanomotors with a SERS sensing technique.The“rod-like”structure is prepared by coating a thin layer of silica onto the self-assembled magnetic nanoparticles.Afterwards,SERS hotspots of silver nanoparticles(AgNPs)are decorated as detecting nanoprobes.The MNM-SPs can be navigated on-demand to avoid obstacles and target sensing sites by the guidance of an external gradient magnetic field.Through applying a rotating magnetic field,the MNM-SPs can actively rotate to efficiently stir and mix surrounding fluid and thus contact with analytes quickly for SERS sensing.Innovatively,we demonstrate the self-cleaning capability of the MNM-SPs which can be used to overcome the contamination problem of traditional single-use SERS probes.Furthermore,the MNM-SPs could precisely approach the targeted single cell and then enter into the cell by endocytosis.It is worth mentioning that by the effective mixing of intracellular biocomponents,much more informative Raman signals with improved signal-to-noise ratio can be captured after active rotation.Therefore,the demonstrated magnetically activated MNM-SPs that are endowed with SERS sensing capability pave way to the future development of smart sensing probes with maneuverability for biochemical analysis at the micro-/nanoscale.

Nanomaterial Labels in Lateral Flow Immunoassays for Point-of-Care-Testing

Lateral flow immunoassays(LFIAs) have been developed rapidly in recent years and used in a wide range of application at point-of-care-testing(POCT),where small biomolecules can be conveniently examined on a test strip.Compared with other biochemical detection methods such as ELISA(enzyme linked immunosorbent assay) or mass spectrometry method,LFIAs have the advantages of low cost,easy operation and short time-consuming.However,it suffers from low sensitivity since conventional LFIA can only realize qualitative detection based on colorimetric signals.With the increasing demand for more accurate and sensitive determination,novel nanomaterials have been used as labels in LFIAs due to their unique advantages in physical and chemical properties.Colloidal gold,fluorescent nano particles,SERSactive nanomaterials,magnetic nanoparticles and carbon nanomaterials are utilized in LFIAs to produce different kinds of signals for quantitative or semi-quantitative detection.This review paper first gives a description of the LFIA principles,and then focuses on the state-of-the-art nanomaterial labelling technology in LFIAs.At last,the conclusion and outlook are given to inspire exploration of more advanced nanomaterials for the development of future LFIAs.

Liquid Metal-Based Epidermal Flexible Sensor for Wireless Breath Monitoring and Diagnosis Enabled by Highly Sensitive SnS_(2) Nanosheets

Real-time wireless respiratory monitoring and biomarker analysis provide an attractive vision for noninvasive telemedicine such as the timely prevention of respiratory arrest or for early diagnoses of chronic diseases.Lightweight,wearable respiratory sensors are in high demand as they meet the requirement of portability in digital healthcare management.Meanwhile,high-performance sensing material plays a crucial role for the precise sensing of specific markers in exhaled air,which represents a complex and rather humid environment.Here,we present a liquid metal-based flexible electrode coupled with SnS_(2) nanomaterials as a wearable gas-sensing device,with added Bluetooth capabilities for remote respiratory monitoring and diagnoses.The flexible epidermal device exhibits superior skin compatibility and high responsiveness(1092%/ppm),ultralow detection limits(1.32 ppb),and a good selectivity of NO gas at ppb-level concentrations.Taking advantage of the fast recovery kinetics of SnS_(2) responding to H_(2) O molecules,it is possible to accurately distinguish between different respiratory patterns based on the amount of water vapor in the exhaled air.Furthermore,based on the different redox types of H_(2) O and NO molecules,the electric signal is reversed once the exhaled NO concentration exceeds a certain threshold that may indicate the onset of conditions like asthma,thus providing an early warning system for potential lung diseases.Finally,by integrating the wearable device into a wireless cloud-based multichannel interface,we provide a proof-of-concept that our device could be used for the simultaneous remote monitoring of several patients with respiratory diseases,a crucial field in future digital healthcare management.

Canine ACL reconstruction with an injectable hydroxyapatite/collagen paste for accelerated healing of tendon-bone interface

Healing of an anterior cruciate ligament(ACL)autologous graft in a bone tunnel occurs through the formation of fibrovascular scar tissue,which is structurally and compositionally inferior to normal fibrocartilaginous insertion and thus may increase the reconstruction failure and the rate of failure recurrence.In this study,an injectable hydroxyapatite/type I collagen(HAp/Col I)paste was developed to construct a suitable local microenvironment to accelerate the healing of bone-tendon interface.Physicochemical characterization demonstrated that the HAp/Col I paste was injectable,uniform and stable.The in vitro cell culture illustrated that the paste could promote MC3T3-E1 cells proliferation and osteogenic expression.The results of a canine ACL reconstruction study showed that the reconstructive ACL had similar texture and color as the native ACL.The average width of the tunnel,total bone volume,bone volume/tissue volume and trabecular number acquired from micro-CT analysis suggested that the healing of tendon-bone interface in experimental group was better than that in control group.The biomechanical test showed the maximal loads in experimental group achieved approximately half of native ACL’s maximal load at 24 weeks.According to histological examination,Sharpey fibers could be observed as early as 12 weeks postoperatively while a typical four-layer transitional structure of insertion site was regenerated at 48 weeks in the experimental group.The injectable HAp/Col I paste provided a biomimetic scaffold and microenvironment for early cell attachment and proliferation,further osteogenic expression and extracellular matrix deposition,and in vivo structural and functional regeneration of the tendon-bone interface.

Artificial intelligence reinforced upconversion nanoparticle-based lateral flow assay via transfer learning

The combination of upconverting nanoparticles(UCNPs)and immunochromatography has become a widely used and promising new detection technique for point-of-care testing(POCT).However,their low luminescence efficiency,non-specific adsorption,and image noise have always limited their progress toward practical applications.Recently,artificial intelligence(AI)has demonstrated powerful representational learning and generalization capabilities in computer vision.We report for the first time a combination of AI and upconversion nanoparticle-based lateral flow assays(UCNP-LFAs)for the quantitative detection of commercial internet of things(IoT)devices.This universal UCNPs quantitative detection strategy combines high accuracy,sensitivity,and applicability in the field detection environment.By using transfer learning to train AI models in a small self-built database,we not only significantly improved the accuracy and robustness of quantitative detection,but also efficiently solved the actual problems of data scarcity and low computing power of POCT equipment.Then,the trained AI model was deployed in IoT devices,whereby the detection process does not require detailed data preprocessing to achieve real-time inference of quantitative results.We validated the quantitative detection of two detectors using eight transfer learning models on a small dataset.The AI quickly provided ultra-high accuracy prediction results(some models could reach 100%accuracy)even when strong noise was added.Simultaneously,the high flexibility of this strategy promises to be a general quantitative detection method for optical biosensors.We believe that this strategy and device have a scientific significance in revolutionizing the existing POCT technology landscape and providing excellent commercial value in the in vitro diagnostics(IVD)industry.

Medical micro-and nanomotors in the body

Attributed to the miniaturized body size and active mobility,micro-and nanomotors(MNMs)have demonstrated tremendous potential for medical applications.However,from bench to bedside,massive efforts are needed to address critical issues,such as cost-effective fabrication,on-demand integration of multiple functions,biocompatibility,biodegradability,controlled propulsion and in vivo navigation.Herein,we summarize the advances of biomedical MNMs reported in the past two decades,with particular emphasis on the design,fabrication,propulsion,navigation,and the abilities of biological barriers penetration,biosensing,diagnosis,minimally invasive surgery and targeted cargo delivery.Future perspectives and challenges are discussed as well.This review can lay the foundation for the future direction of medical MNMs,pushing one step forward on the road to achieving practical theranostics using MNMs.

Integration of flexible,recyclable,and transient gelatin hydrogels toward multifunctional electronics

Facing the challenges posed by exponentially increasing e-waste,the development of recyclable and tran-sient electronics has paved the way to an environmentally-friendly progression strategy,where electron-ics can disintegrate and/or degrade into eco-friendly end products in a controlled way.Natural polymers possess cost and energy efficiency,easy modification,and fast degradation,all of which are ideal prop-erties for transient electronics.Gelatin is especially attractive due to its unique thermoreversible gelation processes,yet its huge potential as a multifunctional electronic material has not been well-researched due to its limited mechanical strength and low conductivity.Herein,we explored versatile applications of gelatin-based hydrogels through the assistance of multifunctional additives like carbon nanotubes to enhance their electromechanical performances.The optimized gelatin hydrogel displays not only a high conductivity of 0.93 S/m,electromagnetic shielding effectiveness of 39.6 dB,and tensile stress tolerance of 263 kPa,but also shows a negative permittivity phenomenon,which may find versatile applications in novel electronics.As a proof of concept,hydrogels were assembled as wearable sensors to sensitively de-tect static and dynamic pressures and strains generated by solids,liquids,and airflow,as well as diverse body movements.Furthermore,the recyclability,biocompatibility,and degradability of gelatin-based hy-drogels were well studied and analyzed.This work outlines a facile method to design multifunctional transient materials for wearable,sustainable,and eco-friendly electronics.

Effects of carbonation on mechanical properties of CAC‑GGBFS blended strain hardening cementitious composites

基于铝酸盐水泥(CAC)的应变硬化水泥基复合材料(SHCC)已成功应用于污水管道的修复。除了微生物引起的腐蚀外,污水环境中的高浓度CO_(2)也会导致管道严重碳化。因此,本文旨在研究碳化对基于CAC的SHCC力学性能的影响。制备了两种不同强度等级的基于CAC的SHCC试样和一种基于普通硅酸盐水泥(OPC)的SHCC试样作为参照。加速碳化试验在CO_(2)浓度为5%的碳化室中进行。首先进行SHCC的抗压和抗拉强度测试,然后利用X射线衍射和扫描电子显微镜等进行微观结构分析。结果表明,由于纤维桥接效应,基于CAC的SHCC试样表现出稳健的应变硬化性能及较大的拉伸变形能力。此外,与基于OPC的SHCC相比,CAC的SHCC抗压和抗拉强度显著提高,并且在碳化后得到更高的拉伸应变能力。微观结构分析表明,碳化后的基于CAC的SHCC试样中的亚稳相转变为稳定相和碳酸钙多晶型,使胶凝基体更致密。本文的研究为利用碳化避免CAC水化产物的不稳定转变提供了新的见解。

Preparation and application of microfluidic SERS substrate:Challenges and future perspectives

Surface-enhanced Raman spectroscopy(SERS),as a highly sensitive molecular analysis technique,can realize fast and non-destructive detection of the information of molecular bonds to identify the component of analytes by"fingerprint"identification.The preparation of SERS substrates plays an extremely important role in the development of SERS technology and the application of SERS detection.By integrating SERS enhancement substrates into microfluidic chips,researchers have developed the microfluidic SERS chips which expand the function of microfluidic chips and provide an efficient platform for on-site biochemical analysis equipped with the powerful sensing capability of SERS technique.In this paper,we will first briefly give a review of the current microfluidic SERS-active substrates preparation technology and present the perspective on the application prospects of microfluidic SERS-active substrates.And then the challenges in the preparation of microfluidic SERS-active substrates will be pointed out,as well as realistic issues of using this technology for biochemical application.

Mesoporous silica as micro/nano-carrier： From passive to active cargo delivery, a mini review

Mesoporous silica has been widely explored for biomedical applications due to its unique structure and good biocompatibility. In particular it exhibits superior properties as micro/nano-carriers in the biomedical field. We explore their potentials in controlled drug/gene co-delivery and photodynamic therapy for cancer treatment both in vitro and in vivo. By incorporating mesoporous silica nanoparticles（MSNP） with two-dimensional nanomaterial, graphene oxide nano-sheet, we utilize MSNP in cellular bio-imaging with squaraine dye. Meanwhile, through delicate combination between mesoporous silica micro/nano carriers with catalytic/bio-catalytic reactions, we manage to achieve self-propelled micro/nano-motors based on mesoporous silica that are capable of transporting cargos in an active manner. Especially, enzyme powered mesoporous silica motors can be powered by physiologically available fuels such as glucose and urea,which are advantageous for future biomedical use. Motion control on both velocity and movement direction provides a powerful tool for targeted drug delivery. Therefore, such mesoporous silica based active carriers pave way to the solution of targeted drug delivery for cancer treatment in future nano-medicine field.

Fundamentals and applications of enzyme powered micro/nano-motors

Micro/nanomotors(MNMs)are miniaturized machines that can convert many kinds of energy into mechanical motion.Over the past decades,a variety of driving mechanisms have been developed,which have greatly extended the application scenarios of MNMs.Enzymes exist in natural organisms which can convert chemical energy into mechanical force.It is an innovative attempt to utilize enzymes as biocatalyst providing driving force for MNMs.The fuels for enzymatic reactions are biofriendly as compared to traditional counterparts,which makes enzyme-powered micro/nanomotors(EMNMs)of great value in biomedical field for their nature of biocompatibility.Until now,EMNMs with various shapes can be propelled by catalase,urease and many others.Also,they can be endowed with multiple functionalities to accomplish on-demand tasks.Herein,combined with the development process of EMNMs,we are committed to present a comprehensive understanding of EMNMs,including their types,propelling principles,and potential applications.In this review,we will introduce single enzyme that can be used as motor,enzyme powered molecule motors and other micro/nano-architectures.The fundamental mechanism of energy conversion process of EMNMs and crucial factors that affect their movement behavior will be discussed.The current progress of proof-of-concept applications of EMNMs will also be elaborated in detail.At last,we will summarize and prospect the opportunities and challenges that EMNMs will face in their future development.