Defect Engineering of Disordered Carbon Anodes with Ultra-High Heteroatom Doping Through a Supermolecule-Mediated Strategy for Potassium-Ion Hybrid Capacitors

Amorphous carbons are promising anodes for high-rate potassium-ion batteries.Most low-temperature annealed amorphous carbons display unsatisfactory capacities.Heteroatom-induced defect engineering of amorphous carbons could enhance their reversible capacities.Nevertheless,most lignocellulose biomasses lack heteroatoms,making it a challenge to design highly heteroatom-doped carbons(>10 at%).Herein,we report a new preparation strategy for amorphous carbon anodes.Nitrogen/sulfur co-doped lignin-derived porous carbons(NSLPC)with ultra-high nitrogen doping levels(21.6 at%of N and 0.8 at%of S)from renewable lignin biomacromolecule precursors were prepared through a supramolecule-mediated pyrolysis strategy.This supermolecule/lignin composite decomposes forming a covalently bonded graphitic carbon/amorphous carbon intermediate product,which induces the formation of high heteroatom doping in the obtained NSLPC.This unique pyrolysis chemistry and high heteroatom doping of NSLPC enable abundant defective active sites for the adsorption of K+and improved kinetics.The NSLPC anode delivered a high reversible capacity of 419 mAh g^(-1)and superior cycling stability(capacity retention of 96.6%at 1 A g^(-1)for 1000 cycles).Potassiumion hybrid capacitors assembled by NSLPC anode exhibited excellent cycling stability(91%capacity retention for 2000 cycles)and a high energy density of 71 Wh kg^(-1)at a power density of 92 W kg^(-1).

Tuning the Corrosion Resistance,Antibacterial Activity,and Cytocompatibility by Constructing Grooves on the Surface of Ti6Al4V3Cu Alloy

Ti6Al4V3Cu alloy is a promising biomaterial for combating implant-related infection.However,the antibacterial property of Ti6Al4V3Cu is expected to be enhanced due to the low content of Cu element in titanium.To address this issue,the antibacterial property of Ti6Al4V3Cu was tailored by the grooves with different groove widths(30μm,60μm,and 90μm)that were constructed on the surface of the Ti6Al4V3Cu by selective laser melting.The effect of grooves on corrosion resistance,antibacterial property,and cytocompatibility was investigated.The electrochemical tests showed that the corrosion resistance decreased with increasing groove width.The antibacterial tests indicated that the groove with a width of 30μm and 90μm groups showed better antibacterial activity against S.aureus(>90%)compared with the groove with a width of 60μm.The in vitro study suggested that all samples with different grooves were found to exhibit good cytocompatibility with osteoblast cells.It is considered that creating grooves on Ti6Al4V3Cu by selective laser melting is a promising strategy to enhance the antibacterial activity without sacrificing cytocompatibility.

In vitro insights into the role of copper ions released from selective laser melted CoCrW-xCu alloys in the potential attenuation of inflammation and osteoclastogenesis

In this study,the CoCrW-x Cu alloys(x=2,3 and 4 wt%)were fabricated using selective laser melting(abbreviated as Co-2 Cu,Co-3 Cu and Co-4Cu)with the purpose of reducing the inflammation responses and the activity of osteoclast.The metal ions releasing test showed that when the Cu content was less than 4 wt%,the releasing amount of Co and Cr ions was very small;however,when 4 wt%Cu was added in the CoCrW based alloy,the quantity of Co ions was significantly elevated with respect to the other groups due to the segregation of precipitates in the matrix;the Cu2+ion quantity of the Co-2Cu,Co-3Cu and Co-4Cu alloys were 0.05,0.09 and 0.27 g/(L cm2)after 7 d immersion,respectively;the RT-q PCR and ELISA data indicated that the expression levels of the pro-inflammatory cytokines(TNF-αand IL-6)were down-regulated in the Co-3Cu and Co-4Cu groups,whereas the expression level of the anti-inflammatory cytokine(IL-10)was up-regulated in all CoCrW-x Cu alloys;meanwhile,the Cu-containing CoCrW alloys significantly down-regulated the expression of the NF-B signal pathway in a Cu content-dependent manner,and the downstream transcription factors of NF-B signal pathway including NFATc1,TRAP and Cath-K were also down-regulated via potentially manipulating the NF-B signal pathway.After comprehensive consideration,it is considered that the Co-3Cu alloy is a potential material for self-alleviating inflammatory responses.

Lanthanum doped octacalcium phosphate/polylactic acid scaffold fabricated by 3D printing for bone tissue engineering

Lanthanum(La)has tremendous potential in the treatment and prevention of bone diseases especially osteoporosis and metabolic disorders.However,controlling its distribution and keeping the release of La^(3+)ions sustained and steady in the body is still a big challenge.In this study,we prepared La-OCP powders via co-precipitation method,and further prepared La-OCP/PLA porous scaffolds by 3 D printing.La^(3+)was successfully introduced into the OCP crystal structure and substituted Ca^(2+)at the Ca-5 and Ca-8 sites.In particular,some La^(3+)ions were deposited on the crystal surface in the form of nanoparticles.Both octacalcium phosphate(OCP,Ca_(8)H_(2)(PO_(4))_6·5 H_(2)O)crystals and nanoparticles played as the carriers for La^(3+)ions.The La-OCP/PLA scaffolds displayed obvious mineralization effects and sustained release of La^(3+).The scaffolds contained a uniform structure with rough micro surface topography which acted as a suitable pathway for BMSCs cells to adhere,grow and proliferation.At a certain La^(3+)concentration,the extracts from La-OCP/PLA scaffolds increased the expression of osteogenesis-related genes,thus promoting the osteogenic differentiation of BMSCs.Moreover,the extracts regulated the immune responses.The experiment in vivo proved that La-OCP/PLA porous scaffolds were safe and could enhance bone defect regeneration in vivo.These findings suggest that 3 D printed La-OCP/PLA porous scaffolds have promising potentials in bone tissue engineering.

Decomposing and mapping different scales of land subsidence over Shanghai with X-and C-Band SAR data stacks

Land subsidence can be observed with time-series of Interferometric Synthetic Aperture Radar(InSAR)data.However,existing approaches only reveal subsidence signals that are multi-scale mixed,which is not conducive to the systematic analysis of subsidence of different mechanisms.A deformation signal decomposition(DSD)method based on spectral analysis is used to decompose the deformation extracted by time-series InSAR into three classes of deformation signals.They refer to large-scale deformation related to geological settings,medium-scale deformation caused more by group excavation,and small-scale deformation along linear infrastructures.TerraSAR-X datasets for Shanghai spanning April 2013 to September 2020,and Sentinel-1A datasets spanning January 2016 to September 2020 are used in this study.The results were cross-verified between the TerraSAR-X and Sentinel-1A datasets,and validated against levelling measurements.Subsidence signals caused by different mechanisms were automatically decomposed,which facilitates a systematic analysis for targeted diagnosis of land subsidence signals.A detailed analysis was conducted jointly at three scales of surface displacement,geological conditions,major construction activities,and subsidence mechanisms.It indicated that construction activities were the leading cause of land subsidence,and suggests that local authorities that wish to mitigate surface subsidence may benefit from primarily considering this process.

Doping Gd^(3+)Ion in PDA-PHBV Coating on Ti6Al4V Alloy for Enhancing Corrosion Resistance and Proliferation of Human Gingival Fibroblasts and Human Umbilical Vein Endothelial Cells

In this study,we fabricated poly(3-hydroxybutyrate-3-hydroxyvalerate)(PHBV)coatings doped with Gd^(3+)(1,5,and 10×10^(−4) mol/L)on Ti6Al4V alloy for the first time to promote soft tissue sealing around dental implants.The corrosion resistance of Gd^(3+)-modified PHBV-coated Ti6Al4V was studied by electrochemical and immersion tests,respectively,whereas CCK-8 and RT-PCR evaluated the biocompatibility to human gingival fibroblasts(HGFs)and human umbilical vein endothelial cells(HUVECs).It was found that the Gd^(3+)-modified PHBV coating could enhance the corrosion resistance of Ti6Al4V.In vitro cell tests showed that PHBV coatings with and without Gd^(3+) addition could promote adhesion and proliferation of HGFs and HUVECs,showing a Gd^(3+) content-dependent manner.Moreover,it was found that the PDA-PHBV@1Gd showed the best proliferation to HGFs by up-regulating gene expressions of VINCULIN,ITGB1,and ITGA3,whereas the best response to HUVECs with the highest gene expression of eNOS and HIF-1αgenes was found in the PDA-PHBV@5Gd-coated group.

Tuning osteoporotic macrophage responses to favour regeneration by Cu-bearing titanium alloy in Porphyromonas gingivalis lipopolysaccharide-induced microenvironments

Guided bone regeneration in inflammatory microenvironments of osteoporotic patients with large alve-olar bone defects remains a great challenge.Macrophages are necessary for alveolar bone regeneration via their polarization and paracrine actions.Our previous studies showed that Cu-bearing Ti6AI4V alloys are capable of regulating macrophage responses.When considering the complexity of oral microenvir-onments,the influences of Cu-bearing Ti6AI4V alloys on osteoporotic macrophages in infectious microenvironments are worthy of further investigations.In this study,we fabricated Ti6AI4V-Cu alloy by selective laser melting technology and used Porphyromonas gingivalis lipopolysaccharide(P.g-LPS)to imitate oral pathogenic bacterial infections.Then,we evaluated the impacts of T6AI4V-Cu on osteoporotic macrophages in infectious microenvironments.Our results indicated that Ti6AI4V-Cu not only inhibited the P.g-LPS-induced M1 polarization and pro-inflammatory cytokine production of osteoporotic macrophages but also shifted polarization towards the pro-regenerative M2 phenotype and remarkably promoted antinflammatory cytokine release.In addition,T6AI4V-Cu effectively promoted the actity of COMMD1 to potentially repress NF-κB-mediated transcription.It is concluded that the Cubearing Ti6AI4V alloy results in ameliorated osteoporotic macrophage responses to create a favourable microenvironment under infectious conditions,which holds promise to develop a GBR-barrier membrane for alveolar bone regeneration of osteoporosis patients.