Irregular LIPSS produced on metals by single linearly polarized femtosecond laser

Currently,supra-wavelength periodic surface structures(SWPSS)are only achievable on silica dielectrics and silicon by femtosecond(fs)laser ablation,while triangular and rhombic laser induced periodic surface structures(LIPSS)are achievable by circularly polarized or linear cross-polarized femtosecond laser.This is the first work to demonstrate the possibility of generating SWPSS on Sn and triangular and rhombic LIPSS on W,Mo,Ta,and Nb using a single linearly polarized femtosecond laser.We discovered,for the first time,SWPSS patches with each possessing its own orientation,which are completely independent of the light polarization direction,thus,breaking the traditional rules.Increasing the laser power enlarges SWPSS periods from 4–6μm to 15–25μm.We report a maximal period of 25μm,which is the largest period ever reported for SWPSS,~10 and~4 times the maximal periods(2.4μm/6.5μm)of SWPSS ever achieved by fs and ns laser ablation,respectively.The formation of triangular and rhombic LIPSS does not depend on the laser(power)or processing(scan interval and scan methodology)parameters but strongly depends on the material composition and is unachievable on other metals,such as Sn,Al,Ti,Zn,and Zr.This paper proposes and discusses possible mechanisms for molten droplet generation/spread/solidification,Marangoni convection flow for SWPSS formation,and linear-to-circular polarization transition for triangular and rhombic LIPSS formation.Reflectance and iridescence of as-prepared SWPSS and LIPSS are characterized.It was found that besides insufficient ablation on W,the iridescence density of Ta-,Mo-,Nb-LIPSS follows the sequence of melting temperatures:Ta>Mo>Nb,which indicates that the melting temperature of metals may affect the regularity of LIPSS.This work may inspire significant interest in further enriching the diversity of LIPSS and SWPSS.

Recent advances in interlayer and separator engineering for lithium-sulfur batteries

Lithium-sulfur(Li-S)batteries have great potential in next-generation energy storage due to its high theoretical specific capacity and energy density.However,there are several challenges to the practical application of Li-S batteries including the growth of lithium dendrites and the shuttle effect of polysulfide.Introducing interlayeres(freestanding or coated on the separator)is an effective approach to reduce these obstacles and improve the electrochemical performance of Li-S batteries.In this review,we briefly summarize the interlayer materials and structures modified on both cathodic and anodic sides including(ⅰ)carbon-based materials,(ⅱ)polymers,(ⅲ)inorganic metal compounds,(iv)metal-organic frameworks,as well as(v)the novel separators in recent years.We also systematically address the fabrication processes,assembling methods,and functions of interlayers for enhancing the performance of Li-S batteries.Furthermore,the prospects and outlooks of the future development of advanced interlayers and separators are also presented.

Effects of Structural Parameters on the Poisson’s Ratio and Compressive Modulus of 2D Pentamode Structures Fabricated by Selective Laser Melting

Metamaterials have been receiving an increasing amount of interest in recent years. As a type of metamaterial, pentamode materials (PMs) approximate the elastic properties of liquids. In this study, a finite-element analysis was conducted to predict the mechanical properties of PM structures by altering the thin wall thicknesses and layer numbers to obtain an outstanding load-bearing capacity. It was found that as the thin wall thickness increased from 0.15 to 0.45 mm, the compressive modulus of the PM structures increased and the Poisson’s ratio decreased. As the layer number increased, the Poisson’s ratio of the PM structures increased rapidly and reaches a stable value ranging from 0.50 to 0.55. Simulation results of the stress distribution in the PM structures confirmed that stress concentrations exist at the junctions of the thin walls and weights. For validation, Ti–6Al–4V specimens were fabricated by selective laser melting (SLM), and the mechanical properties of these specimens (i.e., Poisson’s ratio and elastic modulus) were experimentally studied. Good consistency was achieved between the numerical and experimental results. This work is beneficial for the design and development of PM structures with simultaneous load-bearing capacity and pentamodal properties.

Triplex-structure based DNA circuits with ultra-low leakage and high signal-to-noise ratio

DNA circuits are powerful tools in various applications such as logical computation,molecular diagnosis and synthetic biology.Leakage is a major problem in constructing complex DNA circuits.It directly affects the output signal and harms the circuit’s performance significantly.In the traditional DNA circuits,the gate complex is a duplex structure.There are insufficient energy barriers to prevent spontaneous detachment of strands,resulting in a leak prone.Herein,we have developed triplex-structure based DNA circuit with ultra-low leakage and high signal-to-noise ratio(SNR).The triplex structure improves the stability in the absence of input.At the same time,the driving force of the strand displacement cascades reduces the influence of the triplex structure on the desired reaction.The SNR of the DNA circuit was increased to 695,while the desired reaction rate remained 90%of the conventional translator circuit.The triplex-structure mediated leakage prevention strategy was further tested at different temperatures and in DNA translator and seesaw circuits.We also constructed modular basic logic gates with a high efficiency and low leakage.On this basis,we further constructed triplex-structure based tertiary DNA logic circuits,and the SNR reached 295,which,to the best of our knowledge,was among the highest of the field.We believe that our scheme provides a novel,valid,and general tool for reducing leakages,and we anticipate that it will be widely adopted in DNA nanotechnology.

Erythrocyte membrane encapsulated gambogic acid nanoparticles as a therapeutic for hepatocellular carcinoma

Gambogic acid(GA)is a potential clinical anticancer drug that can exert antitumor effects via various molecular mechanisms.Notwithstanding,GA’s low water solubility,poor stability,short half-life,and unavoidable toxic side effects have significantly hampered its clinical application.Erythrocyte membranecoated nanoparticles(RBCM-NPs)improve drug’s physicochemical properties,biocompatibility,and pharmacokinetic behaviors,allowing for long-term drug circulation and passive targeting.In this study,a novel biomimetic drug delivery system(DDS)against hepatocellular carcinoma was prepared by covering RBCM on GPP-NPs(GA-loaded m PEG-PLA NPs)to develop the RBC@GPP-NPs.In comparison to RBCM-free nanoparticles and free GA,RBC@GPP-NPs improved the drug’s water solubility,stability,safety,and antitumor activity in vivo.We expect that this bionic nanoparticle composite can expand the clinical applicability of GA and provide a feasible solution for the research and development of GA’s nano-formulation.

Femtosecond laser induced simultaneous functional nanomaterial synthesis,in situ deposition and hierarchical LIPSS nanostructuring for tunable antireflectance and iridescence applications

Femtosecond laser induced periodic surface structures(LIPSSs)are excellent biomimetic iridescent antireflective interfaces.In this work,we demonstrate the feasibility to develop tunable iridescent antireflective surfaces via simultaneous synthesis of functional metal-oxide nanomaterials,in situ deposition and hierarchical LIPSSs nanostructuring by means of femtosecond laser ablation(fs-LA)of tungsten(W)and molybdenum(Mo)in air.Adjusting the scanning interval from 1μm to 20μm allows the modulation of particle deposition rates on LIPSSs.Diminishing the scan interval enables a higher particle deposition rate,which facilitates the development of better UV-to-MIR ultrabroadband antireflective surfaces with a less pronounced iridescence.Through comparing the reflectance of hierarchical LIPSSs with different densities of loosely/tightly deposited particles,it is found that the deposited WO_(x)and MoO_(x)particle aggregates have high UV-to-MIR ultrabroadband absorbance,especially extraordinary in the MIR range.Loosely deposited particles which self-assembly into macroporous structures outperform tightly deposited particles for ultrabroadband antireflective applications.The presence of loosely deposited MoO_(x)and WO_(x)particle absorbers can cause up to 80%and 60%enhancement of antireflectance performances as compared to the tightly particle deposited LIPSSs samples.One stone of"fs-LA technique"with three birds of(particle generation,in situ deposition and LIPSS hierarchical nanostructuring)presented in this work opens up new opportunities to tune the reflectance and iridescence of metallic surfaces.

Key chemical composition of walnut(Juglans regia.L)Oils generated with different processing methods and their cholesterol-lowering effects in HepG2 cells

We systematically evaluated fatty acids and triacylglycerol composition,as well as tocopherol,phytosterol,and phenolics,in walnut oil and compared the cholesterol-lowering effects of oil processed with different methods(cold pressing,roast-pressing,hexane extraction,subcritical butane extraction,and supercritical CO_(2) extraction).The different methods did not affect the lipid composition of walnut oil.The tocopherol(41.11 mg/100 g)and total phenolic content(TPC,4.26 mg/100 g)of roast-pressed walnut oil and the phytosterol contents of subcritical butane-extracted walnut oil(106.51 mg/100 g)were higher than those of other tested oils.Walnut oil significantly decreased cholesterol synthesis by downregulating the expression of HMGCR,SREBP-2,and CYP51 genes,and increased cholesterol efflux by upregulating the expression of ABCG1,thus significantly reducing total cholesterol and triacylglycerol.Phytosterols and TPC in walnut oil were responsible for lowering cholesterol;the optimal concentration of phytosterols was 10μg/mL,and that of TPC was 12.5×10^(-3)μg/mL.Through process optimization,a new processing method for walnut oil based on biological evaluation was preliminarily established.

The bioactive of four dietary sources phospholipids on heavy metal-induced skeletal muscle injury in zebrafish:A comparison of phospholipid profiles

Phospholipids have been recognized as significant functional lipids related to nutrition,while they were complex and multiple,and their sources were various.Bioactive functions of phospholipids in skeletal muscle were given serious attention;however,studies on dietary phospholipid profiles with functions on skeletal muscle were rarely reported.Here,we analyzed phospholipid profiles of four kinds of dietary phospholipids(including yolk phospholipid,soybean phospholipid,perilla seed phospholipid and krill oil phospholipid)and compared their composition differences using UPLC-Q-TOF-MS.Lipidomics emphasized significant differences in compositions.Krill oil phospholipid rich inω-3 long-chain polyunsaturated fatty acids(ω-3 LCPUFAs)showed the most excellent effect in skeletal muscle protection.Compared with triglyceride-type lipid(fish oil),phospholipids had higher bioavailability.Besides,as for a higher degree of unsaturation of phospholipid,they did not always perform better effects,which might be related to being more susceptible to suffering from oxidative stress.Overall,four representative phospholipids were analyzed and compared for their bioactive function in skeletal muscle,providing a reference for better understanding relationships between structures and functional applications of phospholipids.