Regulatable Orthotropic 3D Hybrid Continuous Carbon Networks for Efficient Bi-Directional Thermal Conduction

Vertically oriented carbon structures constructed from low-dimen-sional carbon materials are ideal frameworks for high-performance thermal inter-face materials(TIMs).However,improving the interfacial heat-transfer efficiency of vertically oriented carbon structures is a challenging task.Herein,an orthotropic three-dimensional(3D)hybrid carbon network(VSCG)is fabricated by depositing vertically aligned carbon nanotubes(VACNTs)on the surface of a horizontally oriented graphene film(HOGF).The interfacial interaction between the VACNTs and HOGF is then optimized through an annealing strategy.After regulating the orientation structure of the VACNTs and filling the VSCG with polydimethylsi-loxane(PDMS),VSCG/PDMS composites with excellent 3D thermal conductive properties are obtained.The highest in-plane and through-plane thermal conduc-tivities of the composites are 113.61 and 24.37 W m^(-1)K^(-1),respectively.The high contact area of HOGF and good compressibility of VACNTs imbue the VSCG/PDMS composite with low thermal resistance.In addition,the interfacial heat-transfer efficiency of VSCG/PDMS composite in the TIM performance was improved by 71.3%compared to that of a state-of-the-art thermal pad.This new structural design can potentially realize high-performance TIMs that meet the need for high thermal conductivity and low contact thermal resistance in interfacial heat-transfer processes.

Co-Harvest Phase-Change Enthalpy and Isomerization Energy for High-Energy Heat Output by Controlling Crystallization of Alkyl-Grafted Azobenzene Molecules

Photoisomerization-induced phase change are important for co-harvesting the latent heat and isomerization energy of azobenzene molecules.Chemically optimizing heat output and energy delivery at alternating temperatures are challenging because of the differences in crystallizability and isomerization.This article reports two series of asymmetrically alkyl-grafted azobenzene(Azo-g),with and without a methyl group,that have an optically triggered phase change.Three exothermic modes were designed to utilize crystallization enthalpy(△H_(c))and photothermal(isomerization)energy(△H_(p))at different temperatures determined by the crystallization.Azo-g has high heat output(275-303 J g^(-1))by synchronously releasing△H_(c)and△H_(p)over a wide temperature range(-79℃to 25℃).We fabricated a new distributed energy utilization and delivery system to realize a temperature increase of 6.6℃at a temperature of-8℃.The findings offer insight into selective utilization of latent heat and isomerization energy by molecular optimization of crystallization and isomerization processes.

Tailoring Iron-Ion Release of Cellulose-Based Aerogel-Coated Iron Foam for Long-Term High-Power Microbial Fuel Cells

The presence of iron(Fe) has been found to favor power generation in microbial fuel cells(MFCs). To achieve long-term power production in MFCs, it is crucial to effectively tailor the release of Fe ions over extended operating periods. In this study, we developed a composite anode(A/IF) by coating iron foam with cellulose-based aerogel. The concentration of Fe ions in the anode solution of A/IF anode reaches 0.280 μg/mL(Fe^(2+) vs. Fe^(3+) = 61%:39%) after 720 h of aseptic primary cell operation. This value was significantly higher than that(0.198 μg/mL, Fe^(2+) vs. Fe^(3+) = 92%:8%) on uncoated iron foam(IF), indicating a continuous release of Fe ions over long-term operation. Notably, the resulting MFCs hybrid cell exhibited a 23% reduction in Fe ion concentration(compared to a 47% reduction for the IF anode) during the sixth testing cycle(600-720 h). It achieved a high-power density of 301 ± 55 mW/m^(2) at 720 h, which was 2.62 times higher than that of the IF anode during the same period. Furthermore, a sedimentary microbial fuel cell(SMFCs) was constructed in a marine environment, and the A/IF anode demonstrated a power density of 103 ± 3 mW/m^(2) at 3240 h, representing a 75% improvement over the IF anode. These findings elucidate the significant enhancement in long-term power production performance of MFCs achieved through effective tailoring of Fe ions release during operation.

Highly Thermally Conductive Polymer/Graphene Composites with Rapid Room‑Temperature Self‑Healing Capacity

Composites that can rapidly self-healing their structure and function at room temperature have broad application prospects.However,in view of the complexity of composite structure and composition,its self-heal is facing challenges.In this article,supramolecular effect is proposed to repair the multistage structure,mechanical and thermal properties of composite materials.A stiff and tough supramolecular frameworks of 2-[[(butylamino)carbonyl]oxy]ethyl ester(PBA)–polydimethylsiloxane(PDMS)were established using a chain extender with double amide bonds in a side chain to extend prepolymers through copolymerization.Then,by introducing the copolymer into a folded graphene film(FGf),a highly thermally conductive composite of PBA–PDMS/FGf with self-healing capacity was fabricated.The ratio of crosslinking and hydrogen bonding was optimized to ensure that PBA–PDMS could completely self-heal at room temperature in 10 min.Additionally,PBA–PDMS/FGf exhibits a high tensile strength of 2.23±0.15 MPa at break and high thermal conductivity of 13±0.2 W m^(−1)K^(−1);of which the self-healing efficiencies were 100%and 98.65%at room temperature for tensile strength and thermal conductivity,respectively.The excellent self-healing performance comes from the efficient supramolecular interaction between polymer molecules,as well as polymer molecule and graphene.This kind of thermal conductive self-healing composite has important application prospects in the heat dissipation field of next generation electronic devices in the future.

A biomimetic antitumor nanovaccine based on biocompatible calcium pyrophosphate and tumor cell membrane antigens

Currently,the cancer immunotherapy has made great progress while antitumor vaccine attracts substantial attention.Still,the selection of adjuvants as well as antigens are always the most crucial issues for better vaccination.In this study,we proposed a biomimetic antitumor nanovaccine based on biocompatible nanocarriers and tumor cell membrane antigens.Briefly,endogenous calcium pyrophosphate nanogranules with possible immune potentiating effect are designed and engineered,both as delivery vehicles and adjuvants.Then,these nanocarriers are coated with lipids and B16-OVA tumor cell membranes,so the biomembrane proteins can serve as tumor-specific antigens.It was found that calcium pyrophosphate nanogranules themselves were compatible and possessed adjuvant effect,while membrane proteins including tumor associated antigen were transferred onto the nanocarriers.It was demonstrated that such a biomimetic nanovaccine could be well endocytosed by dendritic cells,promote their maturation and antigen-presentation,facilitate lymph retention,and trigger obvious immune response.It was confirmed that the biomimetic vaccine could induce strong T-cell response,exhibit excellent tumor therapy and prophylactic effects,and simultaneously possess nice biocompatibility.In general,the present investigation might provide insights for the further design and application of antitumor vaccines.

高校老年大学发展:态势、困境与对策

我国高校开办的老年大学呈现良好的发展态势,国家日益重视,办学规模不断扩大,社会效益日益凸显。然而,也存在着重视不足,规模不大;开放程度低,发展不均衡;教学内容缺乏针对性,教学方法缺乏灵活性;师资数量匮乏,结构不合理;经费拮据,教学条件有限;法规政策失善,保障机制不健全等问题。今后应采取的措施包括:面向社会成员,服务所在社区;突出针对性,促进老年学员全面发展;实行优势互补,进一步达成资源共享;能者为师,建构合理师资队伍;加大政府经费投入,建立多元化资金筹措机制;健全政策保障机制,规范高校义务;设置老年学专业,加强理论研究。

Carbon-based materials with combined functions of thermal management and electromagnetic protection: Preparation, mechanisms, properties, and applications

The proliferation of high-power,highly informationized,and highly integrated electronic devices and weapons equipment has given rise to increasingly conspicuous issues about electromagnetic(EM)pollution and thermal accumulation.These issues,in turn,impose constraints on the performance of such equipment and jeopardize personnel safety.Carbon materials,owing to their diverse and modifiable structures,offer adjustable thermal and electric conductivity,rendering them highly promising for applications in fields such as thermal management and EM protection which have garnered extensive research and review.The pursuit of integrated device and equipment development has elevated the demand for multifunctional materials,prompting significant research into carbon-based composite materials that include both thermal management and EM protection functionalities.Notably,there are no relevant reviews on this topic at present.Consequently,this work consolidates research findings from recent years on carbon matrix composites exhibiting dual attributes of thermal management and EM protection.These attributes include thermally conductive electromagnetic interference(EMI)shielding materials,thermally insulating EMI shielding materials,thermally conductive EM wave(EMW)absorbing materials,and thermally insulating EMW absorbing materials.The paper elucidates the fundamental principles underpinning thermal conduction,thermal insulation,EMW absorbing,and EMI shielding.Additionally,it engages in discussions surrounding areas of contention,design strategies,and the functional properties of various material designs.Ultimately,the paper concludes by presenting the challenges encountered and potential research strategies about composites endowed with both thermal management and EM protection functionalities,while also envisaging the development of novel multifunctional EM protection materials.

Boosting synergism of chemo- and immunotherapies via switching paclitaxel-induced apoptosis to mevalonate metabolism-triggered ferroptosis by bisphosphonate coordination lipid nanogranules

Conventional chemotherapy based on cytotoxic drugs is facing tough challenges recently following the advances of monoclonal antibodies and molecularly targeted drugs.It is critical to inspire new potential to remodel the value of this classical therapeutic strategy.Here,we fabricate bisphosphonate coordination lipid nanogranules(BC-LNPs)and load paclitaxel(PTX)to boost the chemo-and immuno-therapeutic synergism of cytotoxic drugs.Alendronate in BC-LNPs@PTX,a bisphosphonate to block mevalonate metabolism,works as both the structure and drug constituent in nanogranules,where alendronate coordinated with calcium ions to form the particle core.The synergy of alendronate enhances the efficacy of paclitaxel,suppresses tumor metastasis,and alters the cytotoxic mechanism.Differing from the paclitaxel-induced apoptosis,the involvement of alendronate inhibits the mevalonate metabolism,changes the mitochondrial morphology,disturbs the redox homeostasis,and causes theaccumulation of mitochondrial ROS and lethal lipid peroxides(LPO).These factors finally trigger the ferroptosis of tumor cells,an immunogenic cell death mode,which remodels the suppressive tumor immune microenvironment and synergizes with immunotherapy.Therefore,by switching paclitaxel-induced apoptosis to mevalonate metabolism-triggered ferroptosis,BC-LNPs@PTX provides new insight into the development of cytotoxic drugs and highlights the potential of metabolism regulation in cancer therapy.

Preparation technologies for polymer composites with high-directional thermal conductivity:A review

With the rapid development of science and technology,electronic devices are moving towards miniaturization and integration,which brings high heat dissipation requirements.During the heat dissipation process of a heating element,heat may spread to adjacent components,causing a decrease in the performance of the element.To avoid this situation,the ability to directionally transfer heat energy is urgently needed.Therefore,thermal interface materials(TIMs)with directional high thermal conductivity are more critical in thermal management system of electronic devices.For decades,many efforts have been devoted to the design and fabrication of TIMs with high-directional thermal conductivity.Benefiting from the advantage in feasibility,low-cost and scalability,compositing with thermal conductive fillers has been proved to be promising strategy for fabricating the high-directional thermal conductive TIMs.This review summarizes the present preparation technologies of polymer composites with high-directional thermal conductivity based on structural engineering of thermal conductive fillers,focusing on the manufacturing process,mechanisms,achievements,advantages and disadvantages of different technologies.Finally,we summarize the existing problems and potential challenges in the field of directional high thermal conductivity composites.

Hyperelastic Graphene Aerogels Reinforced by In‑suit Welding Polyimide Nano Fiber with Leaf Skeleton Structure and Adjustable Thermal Conductivity for Morphology and Temperature Sensing

Graphene-aerogel-based flexible sensors have heat tolerances and electric-resistance sensitivities superior to those of polymer-based sensors.However,graphene sheets are prone to slips under repeated compression due to inadequate chemical con-nections.In addition,the heat-transfer performance of existing compression strain sensors under stress is unclear and lacks research,making it difficult to perform real-temperature detections.To address these issues,a hyperelastic polyimide fiber/graphene aerogel(PINF/GA)with a three-dimensional interconnected structure was fabricated by simple one-pot compound-ing and in-situ welding methods.The welding of fiber lap joints promotes in-suit formation of three-dimensional crosslinked networks of polyimide fibers,which can effectively avoid slidings between fibers to form reinforced ribs,preventing graphene from damage during compression.In particular,the inner core of the fiber maintains its macromolecular chain structure and toughness during welding.Thus,PINF/GA has good structural stabilities under a large strain compression(99%).Moreover,the thermal and electrical conductivities of PINF/GA could not only change with various stresses and strains but also keep the change steady at specific stresses and strains,with its thermal-conductivity change ratio reaching up to 9.8.Hyperelastic PINF/GA,with dynamically stable thermal and electrical conductivity,as well as high heat tolerance,shows broad applica-tion prospects as sensors in detecting the shapes and temperatures of unknown objects in extreme environments.

Tetradic double-network physical crosslinking hydrogels with synergistic high stretchable, self-healing, adhesive, and strain-sensitive properties

Herein,we demonstrate a tetradic double-network physical cross-linking hydrogel comprising of gelatin,polyacrylic acid,tannic acid,and aluminum chloride as wearable hydrogel sensors.Based on the coordination bonds,hydrogen bonds,and chain entanglements of the two networks,the acquired hydrogel possesses excellent tensile properties,self-healing performance,and adhesiveness to many substrates.Mechanical properties can be tuned with fracture strain ranging from 900 to 2200%and tensile strength ranging from 24 to 216 kPa,respectively.Besides,the hydrogel also exhibits good strain-sensitivity when monitoring the motions of humans,such as bending of fingers,bending of elbows.Hence,we can believe that the GATA hydrogel has numerous applications in soft robots,intelligent wearable devices,and human health supervision.

Integrated combination delivery of IDO inhibitor and paclitaxel for cancer treatment

In order to realize the combination of chemotherapy and immunotherapy,a reduction-responsive paclitaxel(PTX)prodrug PEG-SS-PTX was synthesized and used as a carrier to encapsulate IDO inhibitor CY-1-4 for preparing PEG-SS-PTX/CY-1-4 NPs.PEG-SS-PTX/CY-1-4 NPs were evaluated by cytotoxicity,immunogenic cell death(ICD)induction ability and anti-tumor efficacy.Dynamic light scattering(DLS)results showed that the size of PEG-SS-PTX/CY-1-4 NPs was about 149 nm.In vitro experiments indicated that its cytotoxicity was in a concentration-dependent manner,and it induced the ICD of B16-F10 cells.In vivo studies in melanoma mouse model indicated that PEG-SS-PTX/CY-1-4 NPs significantly inhibited the tumor growth and reduced the expression of IDO in tumor tissues.Moreover,it increased the rate of CD8+T cells in the spleen.In summary,PEG-SS-PTX/CY-1-4 NPs achieved good anti-tumor effects and reduced the dose of chemotherapy drugs,which was a safe and effective combined delivery system.

Proteomic analysis on cellular response induced by nanoparticles reveals the nano-trafficking pathway through epithelium

The application of nanomedicines in oral drug delivery effectively promotes the drug absorption and transportation through enterocytes.Nevertheless,the absence of mechanism studies on efficacy and safety limits their final translation in humans.Although the vesicular trafficking has been verified as the general character for transport of nanomedicines,the deeper mechanism in molecular mechanism is still unclear.Moreover,the cellular transport of nanomedicines is a dynamic process involved by different organelles and components.However,most of existing studies just pay attention to the static location of nanomedicines,but neglect the dynamic biological effects on cells caused by them.Here,we prepared gold nanoparticles(Au NPs)as the model and cultured epithelial cell monolayer to explore the nano-bio interactions at the molecular level.The traditional pharmacological inhibition strategy and subcellular imaging technology elucidated the macropinocytosis/endosome/MVB/lysosome pathway during the transportation of Au NPs.Proteomics strategy based on mass spectrometry(MS)was utilized to identify and quantify proteins involved in the cellular transport of nanomedicines.Multiple proteins related to subcellular structure,signal transduction,energy transformation and metabolism regulation were demonstrated to be regulated by nanoparticle transport.These alterations of protein expression clarified the effects of intracellular proteins and verified the conventional findings.More importantly,it revealed a feedback mechanism of cells to the nano-trafficking.We believed that these new regulatory mechanisms provided new insights into the efficient transport of nanomedicines through epithelial barriers.

Three-dimensional boron nitride network/polyvinyl alcohol composite hydrogel with solid-liquid interpenetrating heat conduction network for thermal management

Polyvinyl alcohol hydrogels have been used in wearable devices due to their good flexibility and biocompatibility.However,due to the low thermal conductivity(κ)of pure hydrogel,its further application in high power devices is limited.To solve this problem,melamine sponge(MS)was used as the skeleton to wrap boron nitride nanosheets(BNNS)through repeated layering assembly,successfully preparing a three-dimensional(3D)boron nitride network(BNNS@MS),and PVA hydrogels were formed in the pores of the network.Due to the existence of the continuous phonon conduction network,the BNNS@MS/PVA exhibited an improvedκ.When the content of BNNS is about 6 wt.%,κof the hydrogel was increased to 1.12 W m^(-1)K^(-1),about two times higher than that of pure hydrogel.The solid heat conduction network and liquid convection network cooperate to achieve good thermal management ability.Combined with its high specific heat capacity,the composites have an important application prospect in the field of wearable flexible electronic thermal management.

Flexible and elastic thermal regulator for multimode intelligent temperature control

As nonlinear thermal devices,thermal regulators can intelligently respond to temperature and control heat flow through changes in heat transfer capacities,which allows them to reduce energy consumption without external intervention.However,current thermal regulators generally based on high-quality crystallinestructure transitions are intrinsically rigid,which may cause structural damage and functional failure under mechanical strain;moreover,they are difficult to integrate into emerging soft electronic platforms.In this study,we develop a flexible,elastic thermal regulator based on the reversible thermally induced deformation of a liquid crystal elastomer/liquid metal(LCE/LM)composite foam.By adjusting the crosslinking densities,the LCE foam exhibits a high actuation strain of 121%with flexibility below the nematic–isotropic phase transition temperature(TNI)and hyperelasticity above TNI.The incorporation of LMresults in a high thermal resistance switching ratio of 3.8 over a wide working temperature window of 60◦C with good cycling stability.This feature originates from the synergistic effect of fragmentation and recombination of the internal LM network and lengthening and shortening of the bond line thickness.Furthermore,we fabricate a“grid window”utilizing photic-thermal integrated thermal control,achieving a superior heat supply of 13.7℃ at a light intensity of 180mW/cm^(2)and a thermal protection of 43.4℃at 1200 mW/cm^(2).The proposed method meets the mechanical softness requirements of thermal regulatormaterials with multimode intelligent temperature control.

通过优化分子结构实现相变偶氮苯的可控热释放用于低温能量利用

相变偶氮苯衍生物可以基于异构化储存和释放热量.热量输出量和速率受偶氮苯结晶和异构化的影响,同时也受分子结构和相互作用的制约.因此,优化分子结构是控制不同温度下热量释放的一种有效方式.在此,我们制备了三个不对称的烷氧基取代的偶氮苯分子(sAzo),其分子量相似但取代基不同,以研究结晶和异构化之间的权衡.我们研究了s-Azo的温控结晶性和光诱导的异构化动力学.结果表明,由于较强的范德华力,正烷氧基取代使s-Azo具有较高的结晶焓(ΔHCE),但立体阻碍降低了异构化程度.短烷基支化降低了分子相互作用,有利于异构化,使异构化焓(ΔHIE)增加,但降低了ΔHCE.正烷氧基取代的sAzo在-60.49至34.76℃的宽温度范围内表现出光诱导的高能热释放,焓值高达343.3 J g^(-1),功率密度为413 W kg^(-1).同步放热使分布式能量利用的环形装置在低温环境(-5℃)下实现了6.3℃的温升.结果表明,相变偶氮苯衍生物可以通过优化分子结构和相互作用应用于理想的储能系统.

The adsorption of cellular proteins affects the uptake and cellular distribution of gold nanoparticles

Nanotechnology has been widely used in the field of medicine, and it can significantly improve the bioavailability and the target efficiency of medicines. However, after administration, nanomedicines can adsorb biomolecules that can influence their effects. It was reported that the adsorption of plasma proteins can change the surface properties of nanoparticles. When nanoparticles pass through cells, they may carry some cellular proteins out of cells. Currently, it is unclear whether the adsorbed proteins affect the uptake of nanoparticles in the next cell layer. To simplify this complex biological process, BSA-capped gold nanoparticles were prepared and incubated with Caco-2 cell lysate to simulate conditions of transcytosis through epithelial cells. The surface morphology of nanoparticles was examined by TEM. SRB was used to evaluate the cytotoxicity of the nanoparticles. The uptake and cellular distribution of the nanoparticles were detected by ICP-MS and CLSM. The results suggested that the adsorption of cell proteins could enhance the adhesion and uptake of gold nanoparticles. The gold nanoparticles were mainly located in lysosomes, and there were some Lysate-capped AuNPs in the mitochondria whereas no BSA-capped AuNPs appeared there.