Bilayer separator enabling dendrite-free zinc anode with ultralong lifespan >5000 h

Aqueous zinc(Zn)batteries with Zn metal anodes are promising clean energy storage devices with intrinsic safety and low cost.However,Zn dendrite growth severely restricts the use of Zn anodes.To effectively suppress Zn dendrite growth,we propose a bilayer separator consisting of commercial butter paper and glassfiber membrane.The dense cellulose-based butter paper(BP)with low zincophilicity and high mechanical properties prevents the pore-filling behavior of deposited Zn and related separator piercing,effectively suppressing the Zn dendrite growth.As a result,the bilayer separators endow the ZnjjZn symmetrical batteries with a superlong cycling life of Zn anodes(over 5000 h)at 0.5 mA cm^(-2) and the full batteries enhanced capacity retention,demonstrating the advancement of the bilayer separator to afford excellent cyclability of aqueous metal batteries.

Effects of Househould Cleaning Methods on Carbendazim Residue in Apples

Carbendazim,belonging to fungicides,was commonly used for controlling crop diseases,resulting in frequent residues in fruits and vegetables.Washing was the initial step of household fruit processing for cleaning and reducing pollutant contents.However,the effect of washing on the removal of carbendazim in apples was not systemically studied.Thus,in this study,an analytical method was firstly established for the determination of carbendazim with great accuracy and precision through quick,simple,cheap,effective and safe(QuEChERS)method and ultra-performance liquid chromatography-fluorescence detection(UPLC-FLD).Then,the influencing factors were systematically researched to unveil their effects on the carbendazim residue in apples.The results indicated that water temperature,washing products and washing method could obviously affect the carbendazim content in apples.In addition,the best cleaning scheme for removal of carbendazim was soaking apples for 5 min in a cleaning solution,which was prepared by dissolving 8 g of commercial fruit washing soup with 500 ml of water at 45℃.Under this condition,the removal rate of carbendazim in the washing step reached 73.91%.This study will be helpful for providing guidance for household cleaning methods for controlling pesticide residues.

电刺激控制释放地塞米松导电生物膜的制备与性能

为了降低神经电极植入机体产生的炎症反应,构建了一种纳米微结构复合电极。先将多壁碳纳米管(MWCNTs)和地塞米松磷酸钠(Dex)超声混匀后滴涂到电极上,再通过电化学聚合法将一层聚吡咯/聚苯乙烯磺酸钠(PPy/PSS)沉积到MWCNTs覆盖的电极表面,获得一种功能化导电生物膜MWCNTs/Dex@PPy/PSS。采用场发射扫描电镜和傅里叶变换红外光谱对导电生物膜的形貌和成分进行表征,并采用循环伏安法和阻抗扫描对修饰电极的电化学性能进行分析。结果表明,与PPy/Dex导电生物膜相比,所制备的MWCNTs/Dex@PPy/PSS生物膜表现出三维结构表面形貌和更高的电荷存储容量、更低的阻抗及更高的药物释放能力。

ID-OCTA:OCT angiography based on inverse SNR and decorrelation features

Optical coherence tomography angiography(OCTA)takes the flowing red blood cells(RBCs)as intrinsic contrast agents,enabling fast and three-dimensional visualization of vasculature per-fusion down to capillary level,without a requirement of exogenous fluorescent injection.Various motion-contrast OCTA algorithms have been proposed to effectively extract dynamic blood flow from static tissues utilizing the different components of OCT signals(including amplitude,phase and complex)with various operations(such as differential,variance and decorrelation).Those algorithms promote the application of OCTA in both clinical diagnosis and scientific research.The purpose of this paper is to provide a systematical review of OCTA based on the inverse SNR and decorrelation features(ID-OCTA),mainly including the OCTA contrast origins,ID-OCTA imaging,quantification and applications.

Nanoparticle-Decorated Ultrathin La2O3 Nanosheets as an Effcient Electrocatalysis for Oxygen Evolution Reactions

Electrochemical catalysts for oxygen evolution reaction are a critical component for many renewable energy applications. To improve their catalytic kinetics and mass activity are essential for sustainable industrial applications. Here, we report a rare-earth metal-based oxide electrocatalyst comprised of ultrathin amorphous La2O3 nanosheets hybridized with uniform La2O3 nanoparticles(La2O3@NP-NS). Significantly improved OER performance is observed from the nanosheets with a nanometer-scale thickness. The as-synthesized 2.27-nm La2O3@NP-NS exhibits excellent catalytic kinetics with an overpotential of 310 mV at 10 m A cm^-2, a small Tafel slope of 43.1 mV dec^-1, and electrochemical impedance of 38 Ω. More importantly, due to the ultrasmall thickness, its mass activity, and turnover frequency reach as high as 6666.7 A g^-1 and 5.79 s^-1, respectively, at an overpotential of 310 mV. Such a high mass activity is more than three orders of magnitude higher than benchmark OER electrocatalysts, such as IrO2 and RuO2. This work presents a sustainable approach toward the development of highly e cient electrocatalysts with largely reduced mass loading of precious elements.

Swept source intraoperative OCT angiography

To accurately guide surgical instruments during ophthalmic procedures,some necessary intraoperative depth perception is required,which standard surgical microscopes supply limit-edly.Intraoperative optical coherence tomography(iOCT),combining optical coherence to-mography(OCT)technology and surgical microscope,enables noninvasive,real-time and high-resolution cross-sectional imaging.Currently,though iOCT enables structural imaging,little research has been done on intraoperative angiography.In this work,we presented a swept-source intraoperative OCT angiography(SS-iOCTA)system based on a standard surgical microscope,which provides both structural and angiographic images.The feasibility of the proposed SS-iOCTA was confirmed through deep anterior lamellar keratoplasty(DALK)of ex vivo porcine eyes and blood perfusion imaging of in vivo rat cortex.High-resolution intraoperative feedback,including sub-surface structure and angiogram of biological tissue,can be visualized simulta-neously with the SS-iOCTA system,which expand the surgeon's capabilities and could be widely used in clinical surgery.

阿尔茨海默病的血液生物标志物:一项基于中国多中心的横断面和纵向研究

阿尔茨海默病(AD)的生物标志物在血液中含量可能因种族、老年性疾病与各种环境风险因素等不同而存在差异,尚缺乏系统性的研究来评估AD生物标志物在中国老年及AD患者人群中的变化以及是否具有准确预测脑内淀粉样蛋白沉积的能力.本工作为一项多中心纵向队列研究,共纳入来自全国各地6个不同临床中心的817个血液样本.研究测量了多个国际上通用的AD生物标志物,包括β-淀粉样蛋白40与42、磷酸化Tau(pTau)蛋白、总Tau蛋白、神经纤维丝轻链(NFL)和胶质纤维酸性蛋白(GFAP),并使用淀粉样斑块PET示踪剂和核磁结构影像对受试者进行综合评估.研究发现,APOE基因型与血浆pTau或血清GFAP组合的预测模型对脑内淀粉样斑块的沉积状态具有较好的区分能力.此外,研究还发现GFAP基线水平越高的患者其神经退行性变的速度越快.本研究结果基于多中心数据,论证了AD血液生物标志物在中国汉族人群中的实用性和应用前景,提示了血液pTau和GFAP是检测AD早期症状的有效指标,为我国AD的早期诊断和治疗提供了参考.

Simultaneously enhanced interfacial shear strength and tensile strength of heterocyclic aramid fiber by graphene oxide

Heterocyclic aramid fibers,a typical kind of high-performance fibers,have been widely used in aerospace and protection fields because of their excellent mechanical properties.However,the application of heterocyclic aramid fibers as a reinforcement is hindered by the weak interfacial combination with matrix materials,especially epoxy.Traditional strategies enhancing the interfacial shear strength(IFSS)usually decrease the tensile strength.Therefore,simultaneous enhancement of both mechanical properties remains a challenge.Herein,we report a novel heterocyclic aramid fiber with high interfacial shear strength(49.3 MPa)and tensile strength(6.27 GPa),in which 4,4′-diamino-2′-chlorobenzanilide(DABA-Cl)and a small amount of graphene oxide(GO)are introduced through in-situ polymerization.Hydrogen bonds andπ–πinteraction between GO and polymer chains trigger the enhancement in crystallinity,orientation,and lateral interaction of the fibers,thus improving the tensile strength and interfacial shear strength of the fibers.Moreover,the interfacial interaction between fiber and epoxy is enhanced due to the improvement of the surface polarity of the fibers caused by DABA-Cl.Therefore,a method to improve both tensile strength and interfacial shear strength of heterocyclic aramid fibers was found by introducing GO and DABA-Cl,which may provide guidance for the design and preparation of other high-performance fibers.

财务与会计领域的文本分析研究:回顾与展望

随着大数据技术的日益成熟,以文本为对象的研究正引起学术界的重视,但目前尚处于起步阶段,有必要对文本分析技术和文献进行系统梳理。文章从文本信息来源、文本分析技术、文本特征提取、文本分析应用、国内文本分析研究现状五个维度对财务与会计领域现有文本分析技术和文献进行了详细介绍,并指出未来研究方向,有助于国内学者了解财务与会计领域文本分析研究的特征与进展,引起更多学者对财务与会计领域文本分析研究的重视。

In vitro study of enhanced photodynamic cancer cell killing effect by nanometer-thick gold nanosheets

Photodynamic therapy(PDT)by near-infrared(NIR)irradiation is a promising technique for treating various cancers.Here,we reported the development of free-standing wafer-scale Au nanosheets(NSs)that exhibited an impressive PDT effect.The Au NSs were synthesized by ionic layer epitaxy at the air-water interface with a uniform thickness in the range from 2 to 8.5 nm.These Au NSs were found very effective in generating singlet oxygen under NIR irradiation.In vitro cellular study showed that the Au NSs had very low cytotoxicity and high PDT efficiency due to their uniform 2D morphology.Au NSs could kill cancer cells after 5 min NIR irradiation with little heat generation.This performance is comparable to using 10 times mass loading of Au nanoparticles(NPs).This work suggests that two-dimensional(2D)Au NSs could be a new type of biocompatible nanomaterial for PDT of cancer with an extraordinary photon conversion and cancer cell killing efficiency.

Targeted mutagenesis in Arabidopsis thaliana using CRISPR-Casi2b/C2ci^°°

Casi2b/C2ci is a newly identified class 2 CRISPR endonuclease that was recently engineered for targeted genome editing in mammals and rice.To explore the potential applications of the CRISPR-Casi2b system in the dicot Arabidopsis thaliana,we selected BvCasi2b and BhCasi2b v4 for analysis.We successfully used both endonucleases to induce mutations,perform multiplex genome editing,and create large deletions at multiple loci.No significant mutations were detected at potential off-target sites.Analysis of the insertion/deletion frequencies and patterns of mutants generated via targeted gene mutagenesis highlighted the potential utility of CRISPRCasi2b systems for genome editing in Arabidopsis.

Functions of Phytic Acid in Fabricating Metal-Free Carbocatalyst for Oxidative Coupling of Benzylamines

of main observation and conclusion Sustainable phytic acid and cellulose are selected as precursors to fabricate P-doped carbon material(C-P-500),which possesses the high surface area and exhibits excellent catalytic activity and stability in the oxidative coupling of benzylamines(conversion>95%,yield>95%).During the carbonization of cellulose in the muffle furnace,phytic acid can efficiently prevent the cellulose-derived carbon from combustion and create micro/meso porous structure because of its special function of fire retardation.Control experiments and characterizations demonstrate that P-containing groups anchoring on C-P-500 improve the catalytic performance of carbocatalyst in the oxidation of benzylamines to imines.The excellent catalytic activity of C-P-500 should be contributed collectively by carbonyl and P=0(0H)2 groups.Due to the sustainable property of precursors and simple methodology for fabricating P-doped carbocatalyst,along with the moderate reaction conditions,it is a green catalytic system for the oxidative coupling of benzylamines to imines.

The Dynamic Impact of Structural Oil Price Shocks on the Macroeconomy

In this paper,we apply the structural vector autoregression(SVAR)model to decompose the international oil price shock into oil supply shocks,aggregate demand shocks and oil-specific demand shocks,and then use the DCC-GARCH model to analyse the dynamic correlations between these three kinds of oil price shocks and the macroeconomic variables of several oil importing and exporting countries.To quantify the intensity of the effect of oil shocks on these variables,we propose a measure,conditional expectation(Co E),to capture the percent change of the economic variable under oil price shocks relative to the median state.The time-varying copula model is employed to estimate the proposed measure through time.The empirical results show that,for instance,the impacts of oil price shocks on macroeconomic variables are different in different periods,showing the time-varying characteristics.Additionally,the impacts of oil price shocks on macroeconomic variables show great differences and some similarities among different countries.Finally,we give some policy suggestions for these countries,in particular for China’s special results.