Recent advances in optical techniques for dynamically probing cellular mechanobiology

Cellular mechanotransduction characterized by the transformation of mechanical stimuli into biochemical signals,represents a pivotal and complex process underpinning a multitude of cellular functionalities.This process is integral to diverse biological phenomena,including embryonic development,cell migration,tissue regeneration,and disease pathology,particularly in the context of cancer metastasis and cardiovascular diseases.Despite the profound biological and clinical significance of mechanotransduction,our understanding of this complex process remains incomplete.The recent development of advanced optical techniques enables in-situ force measurement and subcellular manipulation from the outer cell membrane to the organelles inside a cell.In this review,we delved into the current state-of-the-art techniques utilized to probe cellular mechanobiology,their principles,applications,and limitations.We mainly examined optical methodologies to quantitatively measure the mechanical properties of cells during intracellular transport,cell adhesion,and migration.We provided an introductory overview of various conventional and optical-based techniques for probing cellular mechanics.These techniques have provided into the dynamics of mechanobiology,their potential to unravel mechanistic intricacies and implications for therapeutic intervention.

Enhancement of CH_(3)CO^(*) adsorption by editing d-orbital states of Pd to boost C–C bond cleavage of ethanol eletrooxidation

Improving the complete ethanol electrooxidation on Pd-based catalysts in alkaline media has drawn widely attention due to the high mass energy density.However,the weak adsorption energy of CH_(3)CO^(*) on Pd restricts the C–C bond cleavage.Inspired by the molecular orbital theory,we proposed the d-state-editing strategy to construct more unoccupied d-states of Pd for the enhanced interaction with CH_(3)CO^(*) to break C–C bonds.As expected,the reduced number of e_g electrons and more unoccupied d-states of Pd successfully formed on as-prepared porous Rh Au–Pd Cu nanosheets(PNSs).Theoretical calculations show that the optimized d-states of Rh Au–Pd Cu PNS can effectively improve the adsorption of CH_(3)CO^(*) and drastically reduce the energy barrier of C–C bond cleavage,thus boosting the complete oxidation of ethanol.The charge ratio of C_1 pathway on Rh Au–Pd Cu PNSs is 51.5%,more than 2 times higher than that of Pd NSs.Our finding provides an innovative perspective for the design of highly-efficient noble-based electrocatalysts.

A novel unified model predicting flow stress and grain size evolutions during hot working of non-uniform as-cast 42CrMo billets

The cast preformed forming process(CPFP) is increasingly considered and applied in the metal forming industries due to its short process, low cost, and environmental friendliness, especially in the aerospace field. However, how to establish a unified model of a non-uniform as-cast billet depicting the flow stress and microstructure evolution behaviors during hot working is the key to microstructure prediction and parameter optimization of the CPFP. In this work, hot compression tests are performed using a non-uniform as-cast 42 CrMo billet at 1123–1423 K and 0.01–1sà1. The effect laws of the non-uniform state of the as-cast billet with different initial grain sizes on the flow stress and microstructure are revealed deeply. Based on experimental results, a unified model of flow stress and grain size evolutions is developed by the internal variable modeling method. Verified results show that the model can well describe the responses of the flow stress and microstructure to deformation conditions and initial grain sizes. To further evaluate its reliability, the unified model is applied to FE simulation of the cast preformed ring rolling process.The predictions of the rolling force and grain size indicate that it could well describe the flow stress and microstructure evolutions during the process.

Recent progress in advanced core-shell metal-based catalysts for electrochemical carbon dioxide reduction

Electrochemical carbon dioxide reduction(CO_(2)RR)plays an important role in solving the problem of high concentration of CO_(2)in the atmosphere and realizing carbon cycle.Core-shell structure has many unique features including tandem catalysis,lattice strain effect,defect engineering,which exhibit great potential in electrocatalysis.In this review,we focus on the advanced core-shell metal-based catalysts(CMCs)for electrochemical CO_(2)RR.The recent progress of CMCs in electrocatalytic CO_(2)RR is described as the follow-ing aspects:(1)The mechanism of electrochemical CO_(2)RR and evaluation parameters of electrocatalyst performance,(2)preparation methods of core-shell metal catalysts and core-shell structural advantages and(3)advanced CMCs towards electrochemical CO_(2)RR.Finally,we make a brief conclusion and propose the opportunities and challenges in the field of electrochemical CO_(2)RR.

On a plastic instability criterion for ultra-large radial-axial ring rolling process with four guide rolls

A dynamic mechanical model is proposed to describe the complexing actions of all the rolls on the ring during the ultra-large radial-axial ring rolling(RARR)process with four guide rolls.Based on the model,the calculation models for bending moment and normal stress at any section of the ring are deduced by force method.If the maximum section bending normal stress exceeds the yield stress of the ring materials,the ring will be distorted thus leading to the instability of the RARR process.According to this,a plastic instability criterion for the ultra-large RARR process with four guide rolls is developed,based on which a mathematical model to calculate the critical guide force for avoiding plastic instability of ring is obtained.The influence rule of the position of guide roll on the dangerous ring section of plastic instability is revealed,from which it is found the dangerous ring section mainly appears at the radial and axial deformation regions and the contact positions of the guide rolls and ring.The optimized layout of guide roll around the ring in favor of stability is determined to be about a1=61°and a2=119°.The plastic instability criterion is proven to be reliable from the aspects of the critical guide force,the section bending moment and normal stress and the dangerous ring section of plastic instability.Intelligent simulation case studies for the RARR process of ultra-large aluminum alloy ring indicate that the stable forming of the process can be effectively realized by regulating the guide force based on the plastic instability criterion.This work could provide a valuable guidance for the control of guide rolls and the optimization of the ultra-large RARR process with four guide rolls.

The electronic structure and optical properties of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) from first-principle calculations

The electronic structure and optical properties of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7)(x¼0,1/8,2/8,3/8,4/8)were studied by first-principle calculations within the generalized gradient approximation approaches(GGA).The lattice constants of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) increase with the increase of Ti^(4+)content caused by the substitution of Ti^(4+)with larger ionic radius for Mn^(4+).Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) is a direct band gap semiconductor,and the band gap(Eg)increases with the increase of Ti^(4+)content.From the density of states,the introduction of Ti-3d states can weaken the effects of Mn-3d states on the bottom of conduction band and has little influence on O-2p states on the top of valence band.The introduction of nonmagnetic Ti^(4+)ions can weaken the magnetism of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7).According to the Mulliken population analysis,it is found that the introduction of Ti^(4+)enhances the electronic accepting capacity of oxygen ions and enhances the electronic losing capacity of manganese ions.The bond strength of Ti–O covalent bond is stronger than that of Mn–O covalent bond.Furthermore,the optical properties of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) was calculated.As Ti^(4+)content increases,the absorption edge of Ca_(3)(Mn_(1-x)Ti_(x))_(2)O_(7) has a blue shift,the static refractive index n0 decreases,the static dielectric constant"1(0)decreases,the position of loss peak moves to higher energy.