Influence of exchange bias on spin torque ferromagnetic resonance for quantification of spin–orbit torque efficiency

Antiferromagnet(AFM)/ferromagnet(FM)heterostructure is a popular system for studying the spin–orbit torque(SOT)of AFMs.However,the interfacial exchange bias field induces that the magnetization in FM layer is noncollinear to the external magnetic field,namely the magnetic moment drag effect,which further influences the characteristic of SOT efficiency.In this work,we study the SOT efficiencies of IrMn/NiFe bilayers with strong interfacial exchange bias by using spin-torque ferromagnetic resonance(ST-FMR)method.A full analysis on the AFM/FM systems with exchange bias is performed,and the angular dependence of magnetization on external magnetic field is determined through the minimum rule of free energy.The ST-FMR results can be well fitted by this model.We obtained the relative accurate SOT efficiencyξ_(DL)=0.058 for the IrMn film.This work provides a useful method to analyze the angular dependence of ST-FMR results and facilitates the accurate measurement of SOT efficiency for the AFM/FM heterostructures with strong exchange bias.

Multifunctional biodegradable nanoplatform based on oxaliplatin prodrug cross-linked mesoporous polydopamine for enhancing cancer synergetic therapy

Due to the limitations of conventional chemotherapy including side effects,poor prognosis,and drug resistance,there is an urgent need for the development of a novel multi-functional combined therapy strategy.Dopamine-modified oxaliplatin prodrug(OXA-DA)was successfully synthesized in this study to ameliorate the organ distribution of oxaliplatin for improving the drug efficacy and reducing toxic side effects,and OXA-DA was applied to develop a porous oxaliplatin cross-linked polydopamine nanoparticle for loading siPD-L1 to construct multifunctional nanoplatform.The multifunctional nanoplatform was modified with poly(2-ethyl-2-oxazoline)(PEOz),which occurred charge reversal in the tumor microenvironment,and exerted the lysosomal escape effect in tumor cells to improve the bioavailability of small interfering RNA targeting programmed cell death-ligand 1(siPD-L1).The pH-responsive charge reversal,photothermal,biodegradation,lysosomal escape ability,PD-L1 protein degradation,toxicity properties and multiple antitumor effects were comprehensively evaluated in vitro and in vivo experiments.The findings indicated that OXA-DA-siPD-L1@PDA-PEOz excellently induced tumor cell necrosis and apoptosis as a result of the synergistic effect of chemo-photothermal therapy,and upregulated CD8+T cells produced interferon-γ(IFN-γ)to further attack the tumor cells.In conclusion,the novel nanoplatform-mediated chemo/photothermal/immunotherapy has promising clinical applications in the treatment of malignant tumors.

Rapidly separating dissolving microneedles with sustained-release colchicine and stabilized uricase for simplified long-term gout management

Despite growing prevalence and incidence,the management of gout remains suboptimal.The intermittent nature of the gout makes the long-term urate-lowering therapy(ULT)particularly important for gout management.However,patients are reluctant to take medication day after day to manage incurable occasional gout flares,and suffer from possible long-term toxicity.Therefore,a safe and easy-tooperate drug delivery system with simple preparation for the long-term management of gout is very necessary.Here,a chitosan-containing sustained-release microneedle system co-loaded with colchicine and uricase liposomes were fabricated to achieve this goal.This microneedle system was confirmed to successfully deliver the drug to the skin and maintain a one-week drug retention.Furthermore,its powerful therapeutic potency to manage gout was investigated in both acute gouty and chronic gouty models.Besides,the drug co-delivery system could help avoid long-term daily oral colchicine,a drug with a narrow therapeutic index.This system also avoids mass injection of uricase by improving its stability,enhancing the clinical application value of uricase.In general,this two-drug system reduces the dosage of uricase and colchicine and improves the patient’s compliance,which has a strong clinical translation.

Polyphenol-based hydrogels: Pyramid evolution from crosslinked structures to biomedical applications and the reverse design

As a kind of nature-derived bioactive materials, polyphenol-based hydrogels possess many unique and outstanding properties such as adhesion, toughness, and self-healing due to their specific crosslinking structures, which have been widely used in biomedical fields including wound healing, antitumor, treatment of motor system injury, digestive system disease, oculopathy, and bioelectronics. In this review, starting with the classi-fication of common polyphenol-based hydrogels, the pyramid evolution process of polyphenol-based hydrogels from crosslinking structures to derived properties and then to biomedical applications is elaborated, as well as the efficient reverse design considerations of polyphenol-based hydrogel systems are proposed. Finally, the existing problems and development prospects of these hydrogel materials are discussed. It is hoped that the unique perspective of the review can promote further innovation and breakthroughs of polyphenol-based hydrogels in the future.

分子印迹荧光传感构建及应用

构建一个高灵敏、高选择性检测痕量分析物的传感器广受科研工作者关注。分子印迹技术由于具有高选择性识别、高容量吸附、快速结合、热稳定性以及低成本等优点,已广泛应用于传感构建领域。以分子印迹聚合物为识别单元,结合荧光传感技术所构建的分子印迹荧光传感器在环境污染物痕量检测方面成为研究重点。本文主要介绍分子印迹聚合物的制备方法,总结分子印迹荧光传感器的构建机理和分子印迹荧光传感器在金属离子、有机小分子以及生物大分子检测方面的应用。重点探讨分子印迹传感器在不同数量的荧光团下检测一种或多种目标分析物的方法,包括单一荧光团检测单一目标物、比率荧光检测单一目标物以及分子印迹荧光传感的多元检测。基于以上分析和总结,提出分子印迹荧光传感器的当前挑战和发展前景。

Formation of coke in thermal cracking of jet fuel under supercritical conditions

Continuous-flow reactor experiments were carried out to study coke formation from thermal crack-ing of home-made jet fuel RP-3 under supercritical con-ditions.The mechanism and precursor of coke forming were analyzed.The starting cracking temperature of RP-3 fuel was determined to be 471.8uC by differential scan-ning calorimetry(DSC).Temperature-programmed oxidation and scanning electron microscopy(SEM)characterizations of the stressed tubes showed that there are three different coke species including chemisorbed carbon,amorphous carbon and filamentous coke in the solid deposits.More than 90%of coke deposits are carried away by the supercritical fluid,which has strong capabilities of extraction for coke deposits and their pre-cursors.There were 17.1 wt-%of iron and 11.1 wt-%of chromium found on the coke surface detected by energy dispersive spectroscopy(EDS)which suggests carbure-tion on alloy.RP-3 fuel and its cracking liquids were analyzed by GC-MS,which showed that the content of alkyl benzene and alkyl naphthalene increased evidently in cracking liquids.

Capturing the crack process of the Antarctic A74 iceberg with Sentinel-1 based offset tracking and radar interferometry techniques

In this paper,the crack process of the A74 iceberg is carefully monitored in different aspects by using synthetic aperture radar(SAR)images.First,a offset tracking strategy is designed to retrieve the temporal evolution of the glacier velocity field.Secondly,a signal coherence factor(SCF)is proposed to analyze the interferometric signals.The resulting SCF maps can present a more distinct rupture pattern than the SAR magnitude images,which enables the development of rift to be tracked more precisely.Thirdly,a new approach is proposed to explore the temporal change of the ice flow.Since this approach is based on interferometric phase signals,it is more sensitive than the offset tracking technique.Consequently,the abnormal variation signals associated with the rupture process can be discovered from the experimental results in an earlier stage.The results also show that the area with abnormal signals is almost identical to the region of the calved ice,which demonstrates that the scale of the iceberg might be predicted at least two months before the rupture event.Furthermore,such a consistent pattern may indicate a total alteration of ice characteristics,implying that the complete separation between A74 and BIS is inevitable.