Adjusting the interfacial adhesion via surface modification to prepare high-performance fibers

Ultra-high molecular weight polyethylene(UHMWPE)fiber is a new kind of high-performance fiber.Due to its excellent physical and chemical characteristics,it is widely used in various fields.However,the surface UHMWPE fiber is smooth and demonstrates no-polar groups.The weak interfacial adhesion between fiber and resin seri-ously restricts the applications of UHMWPE fiber.Therefore,the surface modification treatments of UHMWPE fiber are used to improve the interfacial adhesion strength.The modified method by adding nanomaterials elu-cidates the easy fabrication,advanced equipment and proper technology.Thus,the progress of UHMWPE nanocomposite fibers prepared via adding various nanofillers are reviewed.Meanwhile,the effects of other various methods on surface modification are also reviewed.This work advances the various design strategies about nano technologies on improving interfacial adhesion performance via treatment methodologies.

Electrochemical NO reduction to NH3 on Cu single atom catalyst

Electrochemical NO reduction reaction(NORR)to generate NH_(3)emerges as a fascinating approach to achieve both NO pollution mitigation and sustainable NH_(3)synthesis.Herein,we demonstrate that single-atomic Cu anchored on MoS_(2)(Cu_(1)/MoS_(2))comprising Cu_(1)-S_(3)motifs can serve as a highly efficient NORR catalyst.Cu1/MoS_(2)exhibits an NH_(3)yield rate of 337.5μmol·h^(−1)·cm^(−2)with a Faradaic efficiency of 90.6%at−0.6 V vs.reversible hydrogen electrode(RHE).Combined experiments and theoretical calculations reveal that Cu1-S3 motifs enable the effective activation and hydrogenation of NO through a mixed pathway and simultaneously retard proton coverage,contributing to the high activity and selectivity of Cu1/MoS_(2)for the NORR.

通过引入天然氨基酸基团来设计高容量、长寿命钠离子电池用有机分子电极

有机电极具有结构可设计性强、容量大、可容纳大离子等优点.然而,在钠离子电池中,有机电极材料的容量仍然很低,且其在有机电解质中的高溶解度导致其寿命较短.如何通过化合物设计来提高其性能一直是研究人员关注的问题.本研究通过简单方法将氨基酸接枝到有机化合物上,提高了其容量和循环稳定性.首先,氨基酸之间的氢键使其形成更稳定的层状结构;氨基酸基团在有机电极材料和羧甲基纤维素粘合剂之间形成分子间相互作用,降低界面阻力,显著提高循环稳定性,使得钠离子电池循环次数超过2000次.其次,实验和计算结果表明,氨基酸基团提供了Na^(+)转运途径和额外的可逆存储位点,从而提高了比容量(~300 mA h g^(-1)).本策略可以启发未来钠离子电池的有机分子设计.

人工肾的研究进展

人工肾发展源于肾脏替代治疗的研究,期待能造福尿毒症群体。其方向逐渐突破血液净化常规思维,迈向更全面、更多样的血液净化理念。本文介绍了多种便携式血液净化单元原理及多项研究成果,并详细介绍了细胞工程技术、芯片技术、3D打印技术及异种移植方面的人工肾研究最新进展。

Preparation of La0.67Ca0.23Sr0.1MnO3 thin films with interesting electrical and magnetic properties via pulsed-laser deposition

Manganese oxides with a perovskite-type Re_(1-x)D_xMnO_3(Re:heavy rare-earth elements,D:divalent alkali metal)structure have attracted interest because of the complex interaction between their electrons,lattices,and spins[1-5].Generally,manganese oxides with the structure Re_(1-x)D_xMnO_3 have special properties.For example,the half-metallic manganites,such as La_(2/3)Sr_(1/3)MnO_3 and La_(2/3)Ca_(1/3)MnO_3,wherein the conduction electrons are completely spin polarized。

Engineering hiPSC-CM and hiPSC-EC laden 3D nanofibrous splenic hydrogel for improving cardiac function through revascularization and remuscularization in infarcted heart

Cell therapy has been a promising strategy for cardiac repair after myocardial infarction(MI),but a poor ischemic environment and low cell delivery efficiency remain significant challenges.The spleen serves as a hematopoietic stem cell niche and secretes cardioprotective factors after MI,but it is unclear whether it could be used for human pluripotent stem cell(hiPSC)cultivation and provide a proper microenvironment for cell grafts against the ischemic environment.Herein,we developed a splenic extracellular matrix derived thermoresponsive hydrogel(SpGel).Proteomics analysis indicated that SpGel is enriched with proteins known to modulate the Wnt signaling pathway,cell-substrate adhesion,cardiac muscle contraction and oxidation-reduction processes.In vitro studies demonstrated that hiPSCs could be efficiently induced into endothelial cells(iECs)and cardiomyocytes(iCMs)with enhanced function on SpGel.The cytoprotective effect of SpGel on iECs/iCMs against oxidative stress damage was also proven.Furthermore,in vivo studies revealed that iEC/iCM-laden SpGel improved cardiac function and inhibited cardiac fibrosis of infarcted hearts by improving cell survival,revascularization and remuscularization.In conclusion,we successfully established a novel platform for the efficient generation and delivery of autologous cell grafts,which could be a promising clinical therapeutic strategy for cardiac repair and regeneration after MI.

c-Fos expression in rat brainstem following intake of sucrose or saccharin

To examine whether the activation of brainstem neurons during intake of a sweet tastant is due to orosensory signals or post-ingestive factors,we compared the distribution of c-Fos-like immunoreactivity(c-FLI)in the nucleus of the solitary tract(NST)and parabrachial nucleus(PBN)of brainstem following ingestion of 0.25 M sucrose or 0.005 M saccharin solutions.Immunopositive neurons were localized mainly in the middle zone of the PBN and four rostral-caudal subregions of the NST.Intake of sucrose increased the number of FLI neurons in almost every subnucleus of the PBN(F_((2,13))=7.610,P=0.023),in addition to the caudal NST at the level of the area postrema(F_((2,13))=10.777,P=0.003)and the NST intermediate zone(F_((2,13))=7.193,P=0.014).No significant increase in the number of c-Fos positive neurons was detected in response to saccharin ingestion,although there was a trend towards a modest increase in a few select NST and PBN nuclei.These results suggest that the PBN and NST may be involved in sweet taste perception and modulation of sweet tastant intake,but the significantly enhanced intensity of Fos expression induced by sucrose indicates that PBN/NST neuronal activity is driven by the integrated effects of sweet taste sensation and post-ingestive signals.

LessNet:Lightweight and efficient semantic segmentation for large‐scale point clouds

With a wide range of applications in autonomous driving and robotics,semantic seg-mentation for large‐scale outdoor point clouds is a critical and challenging issue.Due to the large number and irregular arrangement of point clouds,it is difficult to balance the efficiency and effectiveness.In this paper,we propose LessNet,a lightweight and efficient voxel‐based method for LiDAR‐only semantic segmentation,taking advantage of cylin-drical partition and intra‐voxel feature fusion.Specifically,we use a cylindrical partition method to distribute the outdoor point clouds more evenly in voxels.To better encode the voxel features,we adopt an intra‐voxel aggregation method without querying neighbours.The voxel features are further input into a lightweight and effective 3D U‐net to aggregate local features and dilate the receptive field.Extensive experiments prove the satisfied semantic segmentation performance and the improvement of each component in our proposed framework.Our method is capable of processing more than one million point clouds at a time while retaining low latency and few parameters.Moreover,our method achieves comparable performance with state‐of‐the‐art approaches and out-performs all projection‐based methods on the SemanticKITTI benchmark.

Influence of moisture on the interface charge of oil-pressboard composite insulation under DC voltage

The distortion of the electric field in the oil–pressboard composite insulation caused by the accumulation of the interface charge is detrimental to both the insulation design and operation of converter transformers.The influence of moisture content on the surface charge accumulation of oil–pressboard insulation under DC voltage was studied in this study.In accordance with the Kerr electro-optic effect,the electric field strengths in transformer oil and the surface charge density were acquired after applying the positive and negative DC voltages in three oil–pressboard insulation models with different moisture content,respectively.The resistivities of the oil and pressboard in three models,namely Model 1#with 3.8–4.2 ppm moisture in oil and 0.35–0.37%moisture in pressboard,Model 2#with 7.6–7.9 ppm moisture in oil and 0.79–0.82%moisture in pressboard and Model 3#with 14.9–15.4 ppm moisture in oil and 1.39–1.42%moisture in pressboard,was also measured.The results indicate that:(i)as negative charges in oil accumulated on the pressboard surface in a much greater speed than the positive ones,the electric field in transformer oil under negative DC voltage decreases more rapidly with time than that under positive DC voltage;(ii)the increase of the moisture content in both oil and pressboard,under either positive or negative DC voltage,leads to the decrease of both the electric field strength in transformer oil and the charge density with time;and(iii)the increase of moisture content could not only decrease the resistivity of both oil and pressboard,but also the ratio of the resistivity between the pressboard and the oil.On the basis of the Maxwell–Wagner theory,the decrease of the ratio between the pressboard and oil could lead to the decrease of the interfacial charge density,leading to the slow transient process of the electric field in transformer oil under DC voltage.

Rational design of Ruddlesden-Popper perovskite electrocatalyst for oxygen reduction to hydrogen peroxide

Although the oxygen reduction process to hydrogen peroxide(H_(2)O_(2))is a green option for H_(2)O_(2)generation,the low activity and selectivity hindered the industry's process.In recent years,the electrochemical synthesis of H_(2)O_(2)through a 2e-transfer method of oxygen reduction reaction(ORR)has piqued the interest of both academics and industry.Metal oxide catalysts have emerged as a novel family of electrochemical catalysts due to their unusual physical,chemical,and electrical characteristics.In this work,we first developed a Ruddlesden-Popper perovskite oxide(Pr_(2)NiO_(4+δ))as a highly selective and active catalyst for 2e-ORR to produce H_(2)O_(2).Molybdenum was introduced here to adjust the oxidation states of these transition metals with successful substitution into Ni-site to prepare Pr_(2)Ni1-xMoxO_(4+δ),and the molybdenum substitution improves the H_(2)O_(2)selectivity during the ORR process,in 0.1 M KOH,from 60%of Pr_(2)NiO_(4+δ)to 79%of Pr_(2)Ni_(0.8)Mo_(0.2)O_(4+δ)at 0.55 V versus RHE.A limiting H_(2)O_(2)concentration of_0.24 mM for Pr_(2)NiO_(4+δ)and 0.42 mM for Pr_(2)Ni_(0.8)Mo_(0.2)O_(4+δ)was obtained at a constant current of 10 mA/cm2 using a flow-cell reactor using a gas-diffusion electrode.