Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury:state of the art and future perspectives

“Peripheral nerve injury”refers to damage or trauma affecting nerves outside the brain and spinal cord.Peripheral nerve injury results in movements or sensation impairments,and represents a serious public health problem.Although severed peripheral nerves have been effectively joined and various therapies have been offered,recovery of sensory or motor functions remains limited,and efficacious therapies for complete repair of a nerve injury remain elusive.The emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and function.Mesenchymal stem cells,as large living cells responsive to the environment,secrete various factors and exosomes.The latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins,microRNA,and messenger RNA derived from parent mesenchymal stem cells.Exosomes have pivotal roles in cell-to-cell communication and nervous tissue function,offering solutions to changes associated with cell-based therapies.Despite ongoing investigations,mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage.A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical translation.This review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury,exploring the underlying mechanisms.Subsequently,it provides an overview of the current status of mesenchymal stem cell and exosomebased therapies in clinical trials,followed by a comparative analysis of therapies utilizing mesenchymal stem cells and exosomes.Finally,the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes,offering potential solutions and guiding future directions.

数字文化背景下国际战略传播的沟通机制创新研究

信息时代,数字技术对普通公众的赋权加剧了不同文化之间的矛盾和冲突。因此在数字文化背景下,要解决的核心问题是不同文化如何和谐共处,而战略传播是解决这一问题的关键手段。其中沟通是消解意义误读、缓和冲突并形塑公众认知的重要环节。为此,本研究对Web of Science数据库中2007—2023年的国际战略传播文献进行了可视化分析,发现该领域研究呈现出历时性、共时性以及数字化特征,而该特征下的国际战略传播研究发生了认知维度的转向。基于认知转向,本研究以“意义构建—认知争夺—战略认同”为框架构建国际战略传播沟通机制模型,该模型从多元主体协商构建话语联盟、多维话语整合驱动认知争夺、多重受众聚合共建战略认同三个方面呈现国际战略传播的沟通机制。在此基础上,本研究分析了建立战略传播沟通机制的创新因素,以期提升战略传播沟通效能。

Clinical characteristics of 290 foreign-imported cases infected with SARS-CoV-2 in Chengdu, China

Objective:To analyze the epidemiological and clinical characteristics of foreign-imported patients infected with SARS-CoV-2 in Chengdu City.Methods:A total of 290 foreign-imported patients infected with SARS-CoV-2 and discharged from Public Health Clinical Center of Chengdu were included in our study,they were divided into asymptomatic infection group(131 cases)and confirmed cases group(159 cases)in order to compare the epidemiology,clinical characteristics and laboratory tests between two groups.Multi-factor logistic regression analysis was used to investigate the influence factors of becoming a dominant infection after infected with SARS-CoV-2.Results:Among the 290 cases aged from 2 months to 68 years old,83.4%were males,62.1%came from Asia,and 43.8%were complicated with fatty liver disease,the age group of 14-49 years old had the largest number(247 cases).80.5%confirmed case group cases were general type,there was only 1 severe patient.Hospital stays in asymptomatic infection group was shorter than that in confirmed cases group,lymphocyte count,CD4+T count,CD8+T count,CD4+T/CD8+T creatine kinase in two groups half a month after discharge were relatively lower than those on admission,and alanine aminotransferase,aspartate aminotransferase,albumin,lactate dehydrogenase,creatine kinase isoenzyme were relatively higher than those on admission(P<0.05).Logistic regression analysis showed that increased age,decreased lymphocyte count on admission and increased lactate dehydrogenase on admission were associated with dominant infection.Chest CT of 13 general type cases indicated an increase in lesions compared with that at discharge and 3 of them had re-detectable positive RNA test.Conclusion:The majority of foreign-imported cases in Chengdu are mainly from Asia,fewer of them are severe patients.In the early stage of recovery,some SARS-CoV-2 infected patients still have intermittent viral replication.Early isolation and early treatment of imported patients is not only conducive to epidemic prevention and control,but also may change the natural course of the disease.

Evolutionary Decision-Making and Planning for Autonomous Driving Based on Safe and Rational Exploration and Exploitation

Decision-making and motion planning are extremely important in autonomous driving to ensure safe driving in a real-world environment.This study proposes an online evolutionary decision-making and motion planning framework for autonomous driving based on a hybrid data-and model-driven method.First,a data-driven decision-making module based on deep reinforcement learning(DRL)is developed to pursue a rational driving performance as much as possible.Then,model predictive control(MPC)is employed to execute both longitudinal and lateral motion planning tasks.Multiple constraints are defined according to the vehicle’s physical limit to meet the driving task requirements.Finally,two principles of safety and rationality for the self-evolution of autonomous driving are proposed.A motion envelope is established and embedded into a rational exploration and exploitation scheme,which filters out unreasonable experiences by masking unsafe actions so as to collect high-quality training data for the DRL agent.Experiments with a high-fidelity vehicle model and MATLAB/Simulink co-simulation environment are conducted,and the results show that the proposed online-evolution framework is able to generate safer,more rational,and more efficient driving action in a real-world environment.

Will the Globe Encounter the Warmest Winter after the Hottest Summer in 2023?

In the boreal summer and autumn of 2023,the globe experienced an extremely hot period across both oceans and continents.The consecutive record-breaking mean surface temperature has caused many to speculate upon how the global temperature will evolve in the coming 2023/24 boreal winter.In this report,as shown in the multi-model ensemble mean(MME)prediction released by the Institute of Atmospheric Physics at the Chinese Academy of Sciences,a medium-to-strong eastern Pacific El Niño event will reach its mature phase in the following 2−3 months,which tends to excite an anomalous anticyclone over the western North Pacific and the Pacific-North American teleconnection,thus serving to modulate the winter climate in East Asia and North America.Despite some uncertainty due to unpredictable internal atmospheric variability,the global mean surface temperature(GMST)in the 2023/24 winter will likely be the warmest in recorded history as a consequence of both the El Niño event and the long-term global warming trend.Specifically,the middle and low latitudes of Eurasia are expected to experience an anomalously warm winter,and the surface air temperature anomaly in China will likely exceed 2.4 standard deviations above climatology and subsequently be recorded as the warmest winter since 1991.Moreover,the necessary early warnings are still reliable in the timely updated mediumterm numerical weather forecasts and sub-seasonal-to-seasonal prediction.

Dynamic changes in physicochemical property,biogenic amines content and microbial diversity during the fermentation of Sanchuan ham

Sanchuan ham is appreciated in Yunnan Province,China,for its characteristic flavor and taste,while the microbial community structure and biogenic amines content remain unclear during fermentation processes.In this study,we explored the physicochemical property,biogenic amines concentration and microbial diversity of external and internal Sanchuan ham by high-throughput sequencing during the processing of Sanchuan ham.Results showed that the nitrite remained at a stable level of 0.15 mg/kg which was significantly lower than the national health standard safety level of 20 mg/kg.In addition,compared with fresh hams,the content of total free amino acids in ripe Sanchuan ham has grown 14 folds;sour and bitter were the main tastes of Sanchuan ham.Notably,the concentration of cadaverine was the highest of all biogenic amines during the entire fermentation period.At the bacterial phyla level,Firmicutes and Actinobacteria were the two main phyla,while at the genus level,Staphylococcus was a significant strain throughout the whole fermentation.Moreover,the dry stage has a great impact on the succession change of microbial community structure.Simultaneously,the change trends and composition of bacteria in the interior have slight discrepancies with those of the exterior of Sanchuan ham.

Effects of spot size on the operation mode of Ga As photoconductive semiconductor switch employing extrinsic photoconductivity

To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated experimentally.It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation modes.On this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms.Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes.

裙板格栅方向对高速列车设备舱通风性能影响研究

为研究不同方向格栅对高速列车车下设备舱通风性能的影响,以一段某型高速列车实车所用设备舱为试验对象开展了风洞试验,同时基于Realizable k-ε湍流模型构建了风洞试验的数值计算模型.通过风洞试验结果验证了数值模型的准确性,并获得了一套适用于设备舱裙板格栅区域的网格划分参数.基于经风洞试验验证的数值模型和网格划分参数,建立了头车包含设备舱的三车编组数值计算模型.以不同方向格栅(竖向和横向)为研究对象,分析了300 km/h速度等级下设备舱格栅通风口的通风量及设备舱内部的速度分布情况.结果表明:装配两种格栅时,设备舱的总进风质量流率基本一致,其中,装配竖向格栅时,其两侧的进风质量流率基本一致,但装配横向格栅时,其两侧的进风质量流率有所差异,相较于前者,其y-侧的质量流率减少了6.59%,y+侧的增加了6.79%.装配竖向格栅时,气流均匀地从整个格栅区域进入,其进入方向与列车运行方向相同,且速度较小;装配横向格栅时,气流集中从格栅右侧区域进入,其进入方向与列车运行方向相反,且速度较大.通过综合对比质量流率及设备舱空间气流速度,发现装配横向格栅时的通风性能较优.

Malignant glaucoma treated by low-dose laser cycloplasty: a 1-year multicenter prospective noncomparative study

AIM:To report a one-year clinical outcomes of low-dose laser cycloplasty(LCP)among malignant glaucoma patients.METHODS:In this prospective,multicenter,noncomparative clinical study,participants with malignant glaucoma were recruited and underwent LCP at eight ophthalmic centers in China.Patients were followed up at 1wk,1,3,6,and 12mo.Intraocular pressure(IOP),number of glaucoma medications,anterior chamber depth(ACD),and complications were recorded.Anatomical success was defined as the reformation of the anterior chamber based on slit-lamp biomicroscopy.Recurrence was defined by the presence of a shallow orflat anterior chamber after initial recovery from treatment.RESULTS:A total of 34 eyes received LCP.Mean IOP and medications decreased from 36.1±11.5 mm Hg with 3.3±1.5 glaucoma medications pre-treatment to 20.9±9.8 mm Hg(P<0.001)with 2.9±1.6 medications(P=0.046)at 1d,and 17.4±6.7 mm Hg(P<0.001)with 1.3±1.7 medications(P<0.001)at 12mo.The ACD increased from 1.1±0.8 mm at baseline to 1.7±1.0 mm and to 2.0±0.5 mm at 1d and 12mo,respectively.A total of 32(94.1%)eyes achieved initial anatomical success.During follow-up,2(5.9%)eyes failed and 8(23.5%)eyes relapsed,yielding a 12-month anatomical success rate of 64.3%.Complications including anterior synechia(8.82%),choroidal/ciliary detachment(5.88%)and hypopyon(2.94%)were observed within 1wk.CONCLUSION:LCP is simple,safe,and effective in reforming the anterior chamber in malignant glaucoma.

现代儿童观的话语建构:基于多元话语分析视角的探究

现代儿童观作为一种话语性的实在,经历着现代“知识型”的建构,使儿童主体性遭遇了宏大叙事的界说。本文基于多元话语分析理论,通过爬梳现代儿童观背后的话语规则,继而揭开不同“言说者”话语型塑之下的“儿童图像”,透视“话语”建构“儿童”的过程与机制。研究发现,现代儿童观经历着规范话语与情感话语的双重建构,在国家、学校、家庭及市场的言说下,儿童被建构为共产主义的“接班人”、秩序社会的“继承者”、情感无价的“小皇帝”及商品世界的“消费者”,置身被多重期望缠绕的童年。有鉴于此,观照儿童所生活的现实情境成为重新认识儿童的必要路径,包容标准意象之外、发现社会生活之中、理解两种文化之间的儿童,不仅可以避免陷入不可知论的指摘,还有助于审思话语逻辑的权力,形成对儿童的开放性理解。

弥漫性慢性鼻窦炎术后嗅觉预后模型的构建与分析

目的:探讨弥漫性慢性鼻窦炎伴鼻息肉(chronic rhinosinusitis with nasal polyps,CRSwNP)患者的临床特征与初次鼻内镜术后嗅觉预后的关系,建立并验证弥漫性CRSwNP患者初次鼻内镜术后嗅觉改善不佳的列线图预测模型。方法:收集并分析于南京医科大学第一附属医院耳鼻咽喉科行初次鼻内镜手术治疗的67例弥漫性CRSwNP嗅觉障碍患者的临床资料,根据术后嗅觉改善情况分为嗅觉改善组(50例)和嗅觉未改善组(17例),通过单因素和多因素Logistic回归分析影响嗅觉改善的因素,据此建立弥漫性CRSwNP患者初次鼻内镜术后嗅觉预后的列线图模型并评估其预测效果。结果:多因素分析结果提示病程长短(β=0.527,OR=1.693,95%CI:1.139~2.517)、Lund-Mackay鼻窦CT评分(β=0.704,OR=2.021,95%CI:1.208~3.382)、外周血嗜酸性粒细胞比值(β=0.311,OR=1.365,95%CI:1.026~1.815)、筛窦与上颌窦CT评分的比值(β=0.954,OR=2.597,95%CI:1.263~5.340)是弥漫性CRSwNP初次鼻内镜术后嗅觉改善不佳的独立预测因素,据此构建的列线图模型预测弥漫性CRSwNP初次鼻内镜术后嗅觉改善的受试者工作特征(reciever operating characteristic,ROC)曲线的曲线下面积(area under curve,AUC)为0.770(95%CI:0.658~0.881,P<0.01),C指数为0.856(0.817~0.894),校准曲线的绝对误差平均为0.034。结论:根据病程、Lund-Mackay鼻窦CT评分、外周血嗜酸性粒细胞比值、筛窦与上颌窦CT评分的比值构建的列线图模型可以预测弥漫性CRSwNP患者初次鼻内镜术后的嗅觉改善情况,对临床工作有一定的指导作用。

作为交往的连接:共生理论视阈下的海底电缆

学界对人机关系的讨论早已有之,但观点存在分歧,忽视了人机关系的演变在国际传播中的作用;同时国际传播的相关研究极少关注海底电缆之类的基础设施对国际传播中交往关系的赋能。为讨论海底电缆基于人机共生关系在国际传播的交往关系中的作用和影响,本文引入共生理论,将海底电缆视作与国际传播主体共生的单元,从交往的前提、交往的连接、交往的效应三个方面讨论海底电缆作为基础设施,在国际传播的交往中扮演何种角色,以及海底电缆在国际交往中如何连接关系。本文认为海底电缆作为基础设施,其在国际传播空间中以共生单元、共生界面以及与国际传播主体互惠并存的角色存在,并在交往的前提、交往的连接、交往的效应这三个交往阶段发挥作用。

智媒时代国际传播精准化的路径创新

随着智能技术的普遍应用,曾经内嵌于社会逻辑中的技术力量逐渐主导社会进程,全面渗透进日常生活中。人工智能时代传播格局发生重构,算法、机器人写作、智能影像、AR/VR等在信息传播的不同环节都发挥着关键作用。人工智能技术推动国际传播进一步向精准传播迈进。技术赋权大幅拓展国际传播主体,在重构国际新闻生产环节的同时,也催生了场景化、沉浸式的交互式传播,国际传播从以内容为核心的传播逻辑转向以用户为核心的传播逻辑,在大数据分析的基础上,以情感为纽带,在更深层次上触达全球受众。

流程再造:数智技术对中华文化战略传播的变革

顺应战略传播的数字文化和意义共创的发展与转向,战略流程作为战略传播最重要的组成部分也经历了长期的发展、变革与再造,在中华文化战略传播中这一过程尤为显著。在流程再造的过程中,数智技术嵌入的影响是多个层面、多种面向的。为了最大限度地发挥战略流程的作用、推动中华文化战略传播更好地发展,当下需要解决的问题是厘清中华文化的战略传播流程发生了何种变革、数智技术在流程再造中如何发挥作用以及当下的中华文化战略传播流程呈现出何种特征。基于这些问题,本研究梳理了战略传播流程的变革过程,并发现数智技术对中华文化战略传播流程再造的影响在于公众卷入、信息卷入与关系卷入。中华文化战略传播流程再造的过程从而呈现出从宏观到微观、从线性到非线性、从阶段性到历时性、从信息沟通到认知争夺以及从信息说服到意义共创的特征转向。

跨文化情感共同体构建的国家战略与地方实践

智媒时代情感在新闻生产中越来越占据重要地位,将“共情”运用于国际传播的内容维度,有助于打破不同国家间的文化和认知壁垒。首先是凝聚共识,意识形态贯穿于跨国信息流动全过程,凝聚共识与共情传播相辅相成,在议题选择上要具备全球性价值取向,关注前瞻性主流性议题,同时重视本土议题的全球性延展;其次是深化共意,借助多模态媒介技术为受众提供更紧密、多层次的共情体验,此外深度追踪挖掘海内外用户的情感数据,以消解国际新闻生产中的文化折扣与认知隔阂;最后是从内容生产转向内容池的打造,当下国际新闻生产主体大为拓展,促进了基于情感的新闻共享、互动乃至二次创作,使“共情”在更广泛的关系语境中流动,实现全球范围的共情与认同。

Real-Time Co-optimization of Gear Shifting and Engine Torque for Predictive Cruise Control of Heavy-Duty Trucks

Fuel consumption is one of the main concerns for heavy-duty trucks.Predictive cruise control(PCC)provides an intriguing opportunity to reduce fuel consumption by using the upcoming road information.In this study,a real-time implementable PCC,which simultaneously optimizes engine torque and gear shifting,is proposed for heavy-duty trucks.To minimize fuel consumption,the problem of the PCC is formulated as a nonlinear model predictive control(MPC),in which the upcoming road elevation information is used.Finding the solution of the nonlinear MPC is time consuming;thus,a real-time implementable solver is developed based on Pontryagin’s maximum principle and indirect shooting method.Dynamic programming(DP)algorithm,as a global optimization algorithm,is used as a performance benchmark for the proposed solver.Simulation,hardware-in-the-loop and real-truck experiments are conducted to verify the performance of the proposed controller.The results demonstrate that the MPC-based solution performs nearly as well as the DP-based solution,with less than 1%deviation for testing roads.Moreover,the proposed co-optimization controller is implementable in a real-truck,and the proposed MPC-based PCC algorithm achieves a fuel-saving rate of 7.9%without compromising the truck’s travel time.

非完全信息下无人机集群对抗研究综述

无人机集群以其具备的应用优势及发展前景,成为当前人工智能领域研究者关注的热点之一。而非完全信息下的无人机集群对抗技术,因其集群结构变化的高动态性以及环境信息复杂多变且不能完全感知的特点,成为对集群协同性与智能性要求最高的研究方向之一。其研究成果可以促进智能化无人系统的快速发展和广泛应用。该文全面回顾了非完全信息环境下无人机集群对抗研究的最新进展,按照包以德循环理论的思路将无人机集群对抗过程划分为态势评估、意图推断、任务规划与机动决策4个相互衔接的关键组成部分,并进一步将其细分为8个子研究目标。通过分析比较近年来的相关研究,着重阐述了无人机集群对抗领域各项任务的研究重点和难点以及已取得的成果,并讨论了无人机集群对抗技术所面临的挑战,包括大规模异构集群的协同控制、非完全信息的处理、复杂决策过程的建模以及实际应用任务的应对等。

Enhanced Li storage of pure crystalline-C_(60) and TiNb_(2)O_(7)-nanostructure composite for Li-ion battery anodes

We propose a method for producing composite materials(hTNO@C_(60))comprising crystalline C_(60)particles and hollow-structu red TiNb_(2)O_(7)(hTNO)nanofibers via facile liquid-liquid interface precipitation followed by low-temperature annealing.This allows the systematic design of crystalline C_(60)as an active material for Li-ion battery anodes.The hTNO@C_(60)composite demonstrates outstanding cyclic stability,retaining a capacity of 465 mA h g^(-1)after 1,000 cycles at 1 A g^(-1)It maintains a capacity of 98 mA h g^(-1)even after16,000 ultralong cycles at 8 A g^(-1)The enhancement in electrochemical properties is attributed to the successful growth and uniform doping of crystalline C_(60),resulting in improved electrical conductivity.The excellent electrochemical stability and properties of these composites make them promising anode materials.

Two positive effects with one arrow:Modulating crystal and interfacial decoration towards high-potential cathode material

As the primary suppliers of cyclable sodium ions,O3-type layer-structured manganese-based oxides are recognized as highly competitive cathode candidates for sodium-ion batteries.To advance the development of high-energy sodium-ion batteries,it is crucial to explore cathode materials operating at high voltages while maintaining a stable cycling behavior.The orbital and electronic structure of the octahedral center metal element plays a crucial role in maintaining the octahedra structural integrity and improving Na^(+)ion diffusion by introducing heterogeneous chemical bonding.Inspired by the abundant configuration of extra nuclear electrons and large ion radius,we employed trace amounts of tungsten in this study.The obtained cathode material can promote the reversibility of oxygen redox reactions in the high-voltage region and inhibit the loss of lattice oxygen.Additionally,the formation of a Na_(2)WO_(4) coating on the material surface can improve the interfacial stability and interface ions diffusion.It demonstrates an initial Coulombic efficiency(ICE)of 94.6%along with 168.5 mA h g^(-1 )discharge capacity within the voltage range of 1.9-4.35 V.These findings contribute to the advancement of high-energy sodium-ion batteries by providing insights into the benefits of tungsten doping and Na_(2)WO_(4) coating on cathode materials.

Comparison of fish communities using environmental DNA metabarcoding and capture methods in a plateau Erhai Lake,China

Environmental DNA(eDNA)has been used as an important tool for fish diversity analysis,which can greatly solve the problems in traditional survey methodology.However,little work has been done on the actual monitoring accuracy of eDNA.In this study,we analyzed the current status of fish resources in Erhai Lake in Yunnan,SW China,by dividing the lake into three sectors according to habitat differences,and compared the results of eDNA and traditional capture methods to investigate the shortcomings of the current analysis of eDNA results.A total of 27 fish species were detected by eDNA and traditional capture methods,including 20 and 19 fish species,respectively,and additional differences in fish composition between the two methods.The alpha diversity showed higher fish abundance and lower fish diversity by eDNA method compared to the traditional capture method,demonstrating that eDNA was not superior for use in fish diversity analysis.Fish community similarity analysis showed that community differences were generally significant for eDNA(P<0.05).RDA analysis indicated that environmental factors did not significantly affect fish communities monitored by the eDNA method.However,water temperature,aquatic plants,and water depth had significant(P<0.05)effects on fish communities in the traditional capture method,suggesting that eDNA results are insensitive to the effects of environmental factors.Our results illustrate the effectiveness of eDNA in fish identification and the issues in quantification compared to traditional capture methods.Therefore,combining eDNA with traditional methods is a more effective method for analyzing eDNA metabarcoding,following which the protocols of both quantitative methods can be designed to explore the regularity of eDNA quantification.