Mesenchymal stem cell-derived exosomes regulate microglia phenotypes:a promising treatment for acute central nervous system injury

There is growing evidence that long-term central nervous system(CNS)inflammation exacerbates secondary deterioration of brain structures and functions and is one of the major determinants of disease outcome and progression.In acute CNS injury,brain microglia are among the first cells to respond and play a critical role in neural repair and regeneration.However,microglial activation can also impede CNS repair and amplify tissue damage,and phenotypic transformation may be responsible for this dual role.Mesenchymal stem cell(MSC)-derived exosomes(Exos)are promising therapeutic agents for the treatment of acute CNS injuries due to their immunomodulatory and regenerative properties.MSC-Exos are nanoscale membrane vesicles that are actively released by cells and are used clinically as circulating biomarkers for disease diagnosis and prognosis.MSC-Exos can be neuroprotective in several acute CNS models,including for stroke and traumatic brain injury,showing great clinical potential.This review summarized the classification of acute CNS injury disorders and discussed the prominent role of microglial activation in acute CNS inflammation and the specific role of MSC-Exos in regulating pro-inflammatory microglia in neuroinflammatory repair following acute CNS injury.Finally,this review explored the potential mechanisms and factors associated with MSCExos in modulating the phenotypic balance of microglia,focusing on the interplay between CNS inflammation,the brain,and injury aspects,with an emphasis on potential strategies and therapeutic interventions for improving functional recovery from early CNS inflammation caused by acute CNS injury.

Resequencing of sweetpotato germplasm resources reveals key loci associated with multiple agronomic traits

Sweetpotato is an important crop that exhibits hexaploidy and high heterozygosity,which limits gene mining for important agronomic traits.Here,314 sweetpotato germplasm resources were deeply resequenced,and 4599509 SNPs and 846654 InDels were generated,among which 196124 SNPs were nonsynonymous and 9690 InDels were frameshifted.Based on the Indels,genome-wide marker primers were designed,and 3219 of 40366 primer pairs were selected to construct the core InDel marker set.The molecular ID of 104 sweetpotato samples verified the availability of these primers.The sweetpotato population structures were then assessed through multiple approaches using SNPs,and diverse approaches demonstrated that population stratification was not obvious for most Chinese germplasm resources.As many as 20 important agronomic traits were evaluated,and a genome-wide association study was conducted on these traits.A total of 19 high-confidence loci were detected in both models.These loci included several candidate genes,such as IbMYB1,IbZEP1,and IbYABBY1,which might be involved in anthocyanin metabolism,carotenoid metabolism,and leaf morphogenesis,respectively.Among them,IbZEP1 and IbYABBY1 were first reported in sweetpotato.The variants in the promoter and the expression levels of IbZEP1 were significantly correlated with f lesh color(orange or not orange)in sweetpotato.The expression levels of IbYABBY1 were also correlated with leaf shape.These results will assist in genetic and breeding studies in sweetpotato.

Establishment and effectiveness evaluation of a scoring system for exertional heat stroke by retrospective analysis

Background: Heat stroke(HS) is a serious, life-threatening disease. However, there is no scoring system for HS so far. This research is to establish a scoring system that can quantitatively assess the severity of exertional heat stroke(EHS).Methods: Data were collected from a total of 170 exertional heat stroke(EHS) patients between 2005 and 2016 from 52 hospitals in China. Univariate statistical methods and comparison of the area under the receiver operating characteristic(ROC) curve(AUC) were used to screen exertional heat stroke score(EHSS) parameters, including but not limited body temperature(T), Glasgow Coma Scale(GCS) and others. By comparing the sizes of the AUCs of the APACHE II, SOFA and EHSS assessments, the effectiveness of EHSS in evaluating the prognosis of EHS patients was verified.Results: Through screening with a series of methods, as described above, the present study determined 12 parameters – body temperature(T), GCS, p H, lactate(Lac), platelet count(PLT), prothrombin time(PT), fibrinogen(Fib), troponin I(Tn I), aspartate aminotransferase(AST), total bilirubin(TBIL), creatinine(Cr) and acute gastrointestinal injury(AGI) classification – as EHSS parameters. It is a 0–47 point system designed to reflect increasing severity of heat stroke. Low(EHSS<20) and high scores(EHSS>35) showed 100% survival and 100% mortality, respectively. We found that AUCEHSS>AUCSOFA>AUCAPACHE II.Conclusions: A total of 12 parameters – T, GCS, p H, Lac, PLT, PT, Fib, Tn I, AST, TBIL, Cr and gastrointestinal AGI classification – are the EHSS parameters with the best effectiveness in evaluating the prognosis of EHS patients. As EHSS score increases, the mortality rate of EHS patients gradually increases.

Multi-parameter ultrasound based on the logistic regression model in the differential diagnosis of hepatocellular adenoma and focal nodular hyperplasia

BACKGROUND Focal nodular hyperplasia(FNH)has very low potential risk,and a tendency to spontaneously resolve.Hepatocellular adenoma(HCA)has a certain malignant tendency,and its prognosis is significantly different from FNH.Accurate identification of HCA and FNH is critical for clinical treatment.AIM To analyze the value of multi-parameter ultrasound index based on logistic regression for the differential diagnosis of HCA and FNH.METHODS Thirty-one patients with HCA were included in the HCA group.Fifty patients with FNH were included in the FNH group.The clinical data were collected and recorded in the two groups.Conventional ultrasound,shear wave elastography,and contrast-enhanced ultrasound were performed,and the lesion location,lesion echo,Young’s modulus(YM)value,YM ratio,and changes of time intense curve(TIC)were recorded.Multivariate logistic regression analysis was used to screen the indicators that can be used for the differential diagnosis of HCA and FNH.A ROC curve was established for the potential indicators to analyze the accuracy of the differential diagnosis of HCA and FNH.The value of the combined indicators for distinguishing HCA and FNH were explored.RESULTS Multivariate logistic regression analysis showed that lesion echo(P=0.000),YM value(P=0.000)and TIC decreasing slope(P=0.000)were the potential indicators identifying HCA and FNH.In the ROC curve analysis,the accuracy of the YM value distinguishing HCA and FNH was the highest(AUC=0.891),which was significantly higher than the AUC of the lesion echo and the TIC decreasing slope(P<0.05).The accuracy of the combined diagnosis was the highest(AUC=0.938),which was significantly higher than the AUC of the indicators diagnosing HCA individually(P<0.05).This sensitivity was 91.23%,and the specificity was 83.33%.CONCLUSION The combination of lesion echo,YM value and TIC decreasing slope can accurately differentiate between HCA and FNH.

添加氟对LiCl-KCl熔盐中钒离子电化学行为的影响

利用X射线光电子能谱(XPS)和拉曼光谱分析含VCl_(3)和KF的LiCl−KCl共晶盐中钒离子的配位化合物形态。研究表明,氟离子会取代氯离子,与V(Ⅲ)结合形成VF_(6)^(3-)。测试F−和Vn+的摩尔浓度比(α)分别为0:1、1:1、2:1、5:1、20:1和50:1条件下钒离子的电化学行为。结果表明,相比未加氟的情况,出现新的还原步骤:VF_(6)^(3-)→V^(2+),钒离子的还原机制变得更加复杂。在LiCl−KCl熔盐中进行6 h电解,金属钒于−2.90 V在钨电极上沉积。SEM−EDS分析结果表明,加入氟离子形成配位化合物VF_(6)^(3-)后,电解产物的粒径减小。

A New Method of Multi-Focus Image Fusion Using Laplacian Operator and Region Optimization

Considering the continuous advancement in the field of imaging sensor, a host of other new issues have emerged. A major problem is how to find focus areas more accurately for multi-focus image fusion. The multi-focus image fusion extracts the focused information from the source images to construct a global in-focus image which includes more information than any of the source images. In this paper, a novel multi-focus image fusion based on Laplacian operator and region optimization is proposed. The evaluation of image saliency based on Laplacian operator can easily distinguish the focus region and out of focus region. And the decision map obtained by Laplacian operator processing has less the residual information than other methods. For getting precise decision map, focus area and edge optimization based on regional connectivity and edge detection have been taken. Finally, the original images are fused through the decision map. Experimental results indicate that the proposed algorithm outperforms the other series of algorithms in terms of both subjective and objective evaluations.

WRF Numerical Simulation Analysis of Meteorological Elements in the Main Urban Area of Chongqing from 2013 to 2015

Using the WRF mesoscale numerical model,based on the FNL global reanalysis data of NCEP,numerical simulations with a resolution of 27,9 and 3 km were carried out on the meteorological elements in four national air quality control stations(Jinyun Mountain,Shapingba,Jiefangbei and Nanping)in the main urban area of Chongqing City in July from 2013 to 2015.The results show that at the concerned points,there was an obvious southeast dominant wind at 850 hPa.The meteorological conditions in July in the main urban area of Chongqing were favorable for the diffusion of pollutants.That is,the height of the mixed layer was higher,and the precipitation was higher;the temperature and wind speed at 850 hPa were higher.Compared with 2013 and 2014,the meteorological conditions in July 2015 were not more favorable for the diffusion of pollutants.

Effect of La on the Corrosion Behavior and Mechanism of 3Ni Weathering Steel in a Simulated Marine Atmospheric Environment

The corrosion behavior and mechanism of 3Ni weathering steel in a simulated oceanic atmospheric environment are investigated in order to comprehend the impacts of La,as determined through electrochemical analysis and rust layer characterization.The results of this study demonstrate that the addition of La enhances the corrosion resistance of 3Ni weathering steel in the marine atmospheric environment,thereby reducing the corrosion rate and improving the protection of the rust layer.The influence of La on corrosion resistance can be attributed to two primary factors.Firstly,La functions as a grain refiner,minimizing the potential difference of the micro-regions on the substrate surface,thereby significantly reducing the corrosion of bare steel in the marine environment.Secondly,La inhibits the process of Fe_(3)O_(4) oxidation back toγ-FeOOH during corrosion at the local site,thus decreasing the formation ofγ-FeOOH and enhancing the charge transfer resistance.This research work may serve as a reference for expanding the application of rare earth elements in the field of weathering steel.

Modeling Long- and Short-Term Service Recommendations with a Deep Multi-Interest Network for Edge Computing

Edge computing platforms enable application developers and content providers to provide context-aware services(such as service recommendations)using real-time wireless access network information.How to recommend the most suitable candidate from these numerous available services is an urgent task.Click-through rate(CTR)prediction is a core task of traditional service recommendation.However,many existing service recommender systems do not exploit user mobility for prediction,particularly in an edge computing environment.In this paper,we propose a model named long and short-term user preferences modeling with a multi-interest network based on user behavior.It uses a logarithmic network to capture multiple interests in different fields,enriching the representations of user short-term preferences.In terms of long-term preferences,users'comprehensive preferences are extracted in different periods and are fused using a nonlocal network.Extensive experiments on three datasets demonstrate that our model relying on user mobility can substantially improve the accuracy of service recommendation in edge computing compared with the state-of-the-art models.

金属有机框架纳米酶在临床检测中的应用

酶作为天然的生物催化剂,在生物化学反应中发挥着重要的作用。由于天然酶受限其固有的缺点(稳定性低、成本高、储存困难等),具有催化活性的人工模拟酶应运而生。近年来,随着纳米材料迅速发展,仿酶催化纳米材料(纳米酶)逐渐受到研究者们的关注。纳米酶是一类具有类似天然酶活性的纳米材料,其制备过程简单、成本较低,有一定环境耐受性。然而大多数纳米酶类酶活性较低,稳定性相对较差,在生物分析应用中存在诸多困难。其中,金属有机框架(MOF)纳米酶具有高比表面积及孔隙率、活性位点均匀、较强的催化活性及稳定性等性质,且合成简单可控、成本低;此外,较天然酶而言,MOF纳米酶也以其独特的生物化学优势,在临床检测中发挥着巨大应用价值。本文主要基于MOF纳米酶的不同酶活性分类(过氧化物酶、氧化酶、过氧化氢酶、超氧化物歧化酶、水解酶),对其在核酸、蛋白质及小分子三大生物标志物在临床检测中的应用进行概述,并进一步展望了其在临床检测中面临的机遇与挑战,以推动MOF纳米酶的临床应用转化。

Investigation on the dynamic behavior of cloud cavitation around a flexible hydrofoil

The objective of this paper is to investigate the dynamic behavior of cloud cavitating flow around a flexible hydrofoil with experimental and numerical methods.The tightly coupled fluid-structure interaction(FSI)modeling is applied and validated with the experimental data.The Q-criterion andω-criterion are applied to illustrate the interaction between the vortex structures and cavities.The flexibility is seen to result in nose-up twist deformation,causing a reduction of the shedding frequency from an increase in the attached cavity length.Due to the flexibility,the fluctuation of load coefficients of the flexible hydrofoil is larger than that of the rigid hydrofoil.Moreover,the re-entrant jet propagation speed of the flexible hydrofoil is greater than that of the rigid hydrofoil.The shed cloud cavity is observed to be uniform along the flexible hydrofoil span under the combined influence of the strong vibration and the gap flow.

关于牙裂综合征的病因和早期诊断的研究进展

牙裂综合征是一种常见的疾病,本文综述了包括牙齿结构不良、异常力和医源性因素等潜在牙裂综合征的病因,以及临床症状、视觉增强、X线、光学成像和其他新技术在牙裂综合征早期诊断的研究进展,以期为牙裂综合征的预防和诊治提供一定的指导意义。

ShadowEth： Private Smart Contract on Public Blockchain

Blockchain is becoming popular as a distributed and reliable ledger which allows distrustful parties to transact safely without trusting third parties. Emerging blockchain systems like Ethereum support smart contracts where miners can run arbitrary user-defined programs. However, one of the biggest concerns about the blockchain and the smart contract is privacy, since all the transactions on the chain are exposed to the public. In this paper, we present ShadowEth, a system that leverages hardware enclave to ensure the confidentiality of smart contracts while keeping the integrity and availability based on existing public blockchains like Ethereum. ShadowEth establishes a confidential and secure platform protected by trusted execution environment （TEE） off the public blockchain for the execution and storage of private contracts. It only puts the process of verification on the blockchain. We provide a design of our system including a protocol of the cryptographic communication and verification and show the applicability and feasibility of ShadowEth by various case studies. We implement a prototype using the Intel SGX on the Ethereum network and analyze the security and availability of the system.

Chip-scale metalens microscope for wide-field and depth-of-field imaging

Microscopy is very important in research and industry,yet traditional optical microscopy suffers from the limited field-of-view(FOV)and depth-of-field(DOF)in high-resolution imaging.We demonstrate a simultaneous large FOV and DOF microscope imaging technology based on a chip-scale metalens device that is implemented by a SiNxmetalens array with a co-and cross-polarization multiplexed dual-phase design and dispersive spectrum zoom effect.A 4-mm×4-mm FOV is obtained with a resolution of 1.74μm and DOF of200μm within a wavelength range of 450 to 510 nm,which definitely exceeds the performance of traditional microscopes with the same resolution.Moreover,it is realized in a miniaturized compact prototype,showing an overall advantage for portable and convenient microscope technology.

Effect of prior martensite on bainite transformation and microstructure of high-carbon nano-bainitic steel

Bainite transformation kinetics,microstructure,and mechanical properties were comparably investigated by X-ray diffraction,scanning electron microscopy,electron backscatter diffraction,transmission electron microscopy observation,and tensile and impact tests for two treatments:with and without quenching before isothermal bainite transformation at 300°C.Both the incubation time and growth stage of bainite transformation are accelerated by the introduction of prior martensite,especially the former.In addition,the bainite microstructure around the prior martensite is refined and shows a similar orientation with the martensite due to the strain field caused by the existence of prior martensite.The finer bainite microstructure and prior martensite improve the strength and hardness of the high-carbon nano-bainitic steel.Although the presence of prior martensite and low misorientation relationship between the martensite and the adjacent bainite microstructure are prejudicial to impact toughness,the nanoscale bainite microstructure can inhibit the crack propagation and then improve the impact toughness of the high-carbon nano-bainitic steel.

Devitrification of Al-Ce Amorphous Ribbon Investigated Using In situ High Energy X-ray Diffraction

Metastable phases formed during vitrification or devitrification open an avenue to study the intrinsic structural hierarchy in amorphous materials.The phase transformation sequence of Al89Ce11 amorphous ribbon was investigated using diff erential scanning calorimetry,in situ high energy X-ray diffraction(HEXRD)and ex situ high-resolution scanning transmission electron microscope.The results reveal the devitrification pathway following the reaction:amorphous→ε-Al_(60)Ce_(11)+fcc-Al→η-Al_(41)Ce_(5)+fcc-Al→Al_(11)Ce_(3)+fcc-Al.It has been found that bothε-Al_(60)Ce_(11)andη-Al_(41)Ce_(5)metastable phases have same Ce-centered 1-6-6-6-1 motif,suggesting that the structural motif can be inherited.Formation of metastable phase with large unit cell is related to the short-range orders developed during solidification.Structural heredity provides a new method to tailor the microstructure and properties of Al-based alloys based on genetic mechanism.

Livable City Standards and Development in China

In recent times, China has shifted its position from the pursuit of pure GDP to that of humanistic GDP, environmental GDP, and to the unified harmonious development of population, resources, and environment. One of the objectives set at the 16th National Congress of the Communist Party of China （CPC） for building a well-off society in all aspects is to construct a harmonious society. A livable city is one of the most important aspects of a harmonious society. Being so called is closely associated with the living quality of the people in that city and one of the important yardsticks to measure the achievements of China＇s reform and development. As a development objective, a livable city should have its standards. However, different countries have advanced their standards differently for judging a livable city. There are still not international unified standards. With the passing of the times, the building of a standard system for a livable city is of increasing value both theoretically and practically. In January 2005, the ＂General City Planning for Beijing Municipality （2004-2020）＂ was approved by the State Council Beijing was the first to make ＂livable city＂ one of its objectives. This will have a significant impact on urban and economic development in the Chinese capital and will have a profound impact on other areas in the effort to build livable cities. In view of the actual conditions of the development of cities in China, this paper has advanced such standards as economic development, social harmony, and amenities for judging whether a city is a livable city, and made empirical analysis of the development of livable cities in China.