Enhancing the stability of Ni Fe-layered double hydroxide nanosheet array for alkaline seawater oxidation by Ce doping

Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.

Growth-associated protein 43 and neural cell adhesion molecule expression following bone marrow-derived mesenchymal stem cell transplantation in a rat model of ischemic brain injury

BACKGROUND： Transplantation of bone marrow-derived mesenchymal stem cells （BMSCs） improves motor functional recovery, but the mechanisms remain unclear. OBJECTIVE： To investigate expression of growth-associated protein 43 （GAP-43） and neural cell adhesion molecule following BMSC transplantation to the lateral ventricle in rats with acute focal cerebral ischemic brain damage. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment using immunohistochemistry was performed at the laboratories of Department of Neurology, Renmin Hospital of Wuhan University and Doctoral Scientific Research Work Station of C-BONS PHARMA, Hubei Province, China, from January 2007 to December 2008. MATERIALS： Monoclonal mouse anti-rat 5-bromo-2-deoxyuridine and neural cell adhesion molecule antibodies were purchased from Sigma, USA; monoclonal mouse anti-rat GAP-43 antibody was purchased from Wuhan Boster, China. METHODS： Rat models of right middle cerebral artery occlusion were established using the thread method. At 1 day after middle cerebral artery occlusion, 20μL culture solution, containing 5×10^5 BMSCs, was transplanted to the left lateral ventricle using micro-injection. MAIN OUTCOME MEASURES： Scores of neurological impairment were measured to assess neural function. Expression of GAP-43 and neural cell adhesion molecule at the lesion areas was examined by immunohistochemistry. RESULTS： GAP-43 and neural cell adhesion molecule expression was low in brain tissues of the sham-operated group, but expression increased at the ischemic boundary （P 〈 0.05）. Transplantation of BMSCs further enhanced expression of GAP-43 and neural cell adhesion molecule （P 〈 0.05） and remarkably improved neurological impairment of ischemic rats （P 〈 0.05）. CONCLUSION： BMSC transplantation promoted neurological recovery in rats by upregulating expression of GAP-43 and neural cell adhesion molecule.

Blockchain for Transparent Data Management Toward 6G

The wealth of user data acts as a fuel for network intelligence toward the sixth generation wireless networks(6G).Due to data heterogeneity and dynamics,decentralized data management(DM)is desirable for achieving transparent data operations across network domains,and blockchain can be a promising solution.However,the increasing data volume and stringent data privacy-preservation requirements in 6G bring significantly technical challenge to balance transparency,efficiency,and privacy requirements in decentralized blockchain-based DM.In this paper,we investigate blockchain solutions to address the challenge.First,we explore the consensus protocols and scalability mechanisms in blockchains and discuss the roles of DM stakeholders in blockchain architectures.Second,we investigate the authentication and authorization requirements for DM stakeholders.Third,we categorize DM privacy requirements and study blockchain-based mechanisms for collaborative data processing.Subsequently,we present research issues and potential solutions for blockchain-based DM toward 6G from these three perspectives.Finally,we conclude this paper and discuss future research directions.

Integrated prodrug micelles with two-photon bioimaging and pH-triggered drug delivery for cancer theranostics

Nanodrug carriers with fluorescence radiation are widely used in cancer diagnosis and therapy due to their real-time imaging,less side effect,better drug utilization as well as the good bioimaging ability.However,traditional nanocarriers still suffer from unexpectable drug leakage,unsatisfactory tumor-targeted drug delivery and shallow imaging depth,which limit their further application in cancer theranostics.In this study,an integrated nanoplatform is constructed by polymeric prodrug micelles with two-photon and aggregation-induced emission bioimaging,charge reversal and drug delivery triggered by acidic pH.The prodrug micelles can be self-assembled by the TPPEI(DA/DOX)-PEG prodrug polymer,which consists of the two-photon fluorophore(TP),dimethylmaleic anhydride(DA)grafted polyethyleneimine(PEI)and polyethylene glycol(PEG).The PEG segment,DOX and DA are bridged to polymer by acid cleavable bonds,which provides the micelles a‘stealth’property and a satisfactory stability during blood circulation,while the outside PEG segment is abandoned along with the DA protection in the tumor acidic microenvironment,thus leading to charge reversal-mediated accelerated endocytosis and tumor-targeted drug delivery.The great antitumor efficacy and reduced side effect of these pH-sensitive prodrug micelles are confirmed by antitumor assays in vitro and in vivo.Meanwhile,these micelles exhibited great deep-tissue two-photon bioimaging ability up to 150 lm in depth.The great antitumor efficacy,reduced side effect and deep two-photon tissue imaging make the TP-PEI(DA/DOX)-PEG prodrug micelles would be an efficient strategy for theranostic nanoplatform in cancer treatment.

Two-photon AIE probe conjugated theranostic nanoparticles for tumor bioimaging and pH-sensitive drug delivery

Nanoparticles armed with chemotherapy drug and fluorescence probe have become an effective anticancer strategy for their advantages in cancer diagnosis and treatment.However,fluorophore for diagnostic medicine with deep penetration depth and high resolution are still very rare,while rational designs are also required to improve the tumor retention and target-site drug delivery.Herein,a two-photon fluorophore with aggregation-induced emission and large two-photon absorption cross-section has been designed for two-photon bioimaging,and a novel theranostic nanoplatform is also constructed based on doxorubicin and the two-photon fluorophore conjugated copolymer,P(TPMA-co-AEMA)-PEI(DA)-Blink-PEG (PAEEBlink-DA).The micelles maintain a “stealth” property during blood circulation and is activated in the acidic tumor microenvironment,which triggers the charge-conversion and results in enhanced micellar internalization.Meanwhile,PAEMA chains can convert from hydrophobicity to hydrophilicity with accelerated drug release and particle size expansion.The enlarged particle size would potentially extend the retention time of these micelles.Moreover,a great AIE active two-photon bioimaging with tissue penetration depth up to 150 μm is observed and the in vivo biodistribution of nanoparticles can be traced.The in vivo antitumor results further indicate the obvious reduction of adverse effect and enhanced treatment effect of these micelles,proving that these PAEEBlink-DA micelles would be a potential candidate for tumor theranostic applications.

A fully absorbable biomimetic polymeric micelle loaded with cisplatin as drug carrier for cancer therapy

cis-dichlorodiammineplatinum(II)(CDDP)-loaded polymeric micelles for cancer therapy have been developed to reduce the serious side effects of cisplatin CDDP.Herein,polymeric micelles incorporated with cisplatin are prepared based on the complexation between CDDP and hydrophilic poly(L-glutamic acid)-b-poly(2-methacryloyloxyethyl phosphorylcholine)(PLG-b-PMPC)diblock copolymers.These CDDP-loaded micelles possess an average size of 91nm with narrow distribution,providing remarkable stability in media containing proteins.The release of CDDP from the micelles is faster at pH 5.0 and pH 6.0 than that at pH 7.4 and in a sustained manner without initial burst release.In addition,there is almost no difference in cellular uptake between these CDDP-loaded micelles and free CDDP.Moreover,in vitro cytotoxicity test shows they possess high efficacy to kill 4T1 cells as compared with free drug.Thus,PLG-b-PMPC copolymer might be a promising carrier for CDDP incorporating in cancer therapy.

A biomimetic and pH-sensitive polymeric micelle as carrier for paclitaxel delivery

As nano-scale drug delivery systems,smart micelles that are sensitive to specific biological environment and allowed for target site-triggered drug release by reversible stabilization of micelle structure are attractive.In this work,a biocompatible and pH-sensitive copolymer is synthesized through bridging poly(2-methacryloyloxyethyl phosphorylcholine)(PMPC)block and poly(D,L-lactide)(PLA)block by a benzoyl imine linkage(Blink).Biomimetic micelles with excellent biocompatibility based on such PLA-Blink-PMPC copolymer are prepared as carriers for paclitaxel(PTX)delivery.Due to the rapid breakage of the benzoyl imine linkage under acidic condition,the micelle structure is disrupted with accelerated PTX release.Such pH-sensitive triggered drug release behavior in synchronization with acidic conditions at tumor site is helpful for improving the utilization of drug and facilitating antitumor efficacy.These micelles can be used as promising drug delivery systems due to their biocompatible and smart properties.

Digital Twin-Empowered Network Planning for Multi-Tier Computing

In this paper,we design a resource management scheme to support stateful applications,which will be prevalent in sixth generation(6G)networks.Different from stateless applications,stateful applications require context data while executing computing tasks from user terminals(UTs).Using a multi-tier computing paradigm with servers deployed at the core network,gateways,and base stations to support stateful applications,we aim to optimize long-term resource reservation by jointly minimizing the usage of computing,storage,and communication resources and the cost of reconfiguring resource reservation.The coupling among different resources and the impact of UT mobility create challenges in resource management.To address the challenges,we develop digital twin(DT)empowered network planning with two elements,i.e.,multi-resource reservation and resource reservation reconfiguration.First,DTs are designed for collecting UT status data,based on which UTs are grouped according to their mobility patterns.Second,an algorithm is proposed to customize resource reservation for different groups to satisfy their different resource demands.Last,a Meta-learning-based approach is developed to reconfigure resource reservation for balancing the network resource usage and the reconfiguration cost.Simulation results demonstrate that the proposed DTempowered network planning outperforms benchmark frameworks by using less resources and incurring lower reconfiguration costs.

Stability research on polydopamine and immobilized albumin on 316L stainless steel

In this study,the polydopamine(PDA)film was coated on polished 316Lss and then thermally treated at 150C(labeled as PDA-Th150),and the stability of coatings was also investigated.Straining test indicated that PDA-Th150 coating performed better in affording sufficient adherence to 316 L SS substrate.Moreover,both PDA and PDA-Th150 coating suffered slight swelling during immersion in deionized water(pH紏6.5).X-ray photoelectron spectroscopy results showed that during immersion,latent nucleophilic reaction via amines inside PDA coating occurred.This led to an enhanced cross-linking and thus gradually promoted the coating stability.Moreover,larger amount of bovine serum albumin(BSA)was immobilized onto PDA-Th150 coating and performed well in anti-platelet adhesion.A high retention of immobilized BSA was observed even after immersion for 30 days.These tests suggested that PDA was stable enough and performed well in surface functionalization,which might enrich the research and application of PDA.

Polyphenol based hybrid nano-aggregates modified collagen fibers of biological valve leaflets to achieve enhanced mechanical,anticoagulation and anti-calcification properties

Glutaraldehyde(Glut)-crosslinked porcine pericardium and bovine pericardium are mainly consisted of collagen and widely used for the preparation of heterogenous bioprosthetic heart valves(BHV),which play an important role in the replacement therapy of severe valvular heart disease,while their durability is limited by degeneration due to calcification,thrombus,endothelialization difficulty and prosthetic valve endocarditis.Herein,we develop a novel BHV,namely,TPly-BP,based on natural tannic acid and polylysine to improve the durability of Glut crosslinked bovine pericardium(Glut-BP).Impressively,tannic acid and polylysine could form nanoaggregates via multiple hydrogen bonds and covalent bonds,and the introduction of nanoaggregates not only improved the mechanical properties and collagen stability but also endowed TPIy-BP with good biocompatibility and hemocompatibility.Compared to Glut-BP,TPIy-BP showed significantly reduced cytotoxicity,improved endothelial cell adhesion,a low hemolysis ratio and obviously reduced platelet adhesion.Importantly,TPly-BP exhibited great antibacterial and in vivo anti-calcification ability,which was expected to improve the in vivo durability of BHVs.These results suggested that TPly-BP would be a potential candidate for BHV.

Polyphenol based hybrid nano-aggregates modified collagen fibers of biological valve leaflets to achieve enhanced mechanical,anticoagulation and anti-calcification properties

Glutaraldehyde(Glut)-crosslinked porcine pericardium and bovine pericardium are mainly consisted of collagen and widely used for the preparation of heterogenous bioprosthetic heart valves(BHV),which play an important role in the replacement therapy of severe valvular heart disease,while their durability is limited by degeneration due to calcification,thrombus,endothelialization difficulty and prosthetic valve endocarditis.Herein,we develop a novel BHV,namely,TPly-BP,based on natural tannic acid and polylysine to improve the durability of Glut crosslinked bovine pericardium(Glut-BP).Impressively,tannic acid and polylysine could form nanoaggregates via multiple hydrogen bonds and covalent bonds,and the introduction of nanoaggregates not only improved the mechanical properties and collagen stability but also endowed TPly-BP with good biocompatibility and hemocompatibility.Compared to Glut-BP,TPly-BP showed significantly reduced cytotoxicity,improved endothelial cell adhesion,a low hemolysis ratio and obviously reduced platelet adhesion.Importantly,TPly-BP exhibited great antibacterial and in vivo anti-calcification ability,which was expected to improve the in vivo durability of BHVs.These results suggested that TPly-BP would be a potential candidate for BHV.