Irreversible Structural Changes Research Articles

Degradation Analysis of Oxide-Based All-Solid-State Na Batteries by Operando Raman Spectroscopy

Oxide-based all-solid-state Na batteries (ASSBs) show promise as alternative systems of conventional Li-ion batteries for large-scaled renewable energy storage owing to the availability of the required resources and the safety of these devices. ASSBs are usually prepared by a sintering method and have several performance disadvantages, such as capacity degradation with cycling. In this study, we prepared [NaTi2(PO4)3 (NTP) negative electrode|Na3Zr2Si2PO12 (NZSP) electrolyte|Na4Ni3(PO4)2P2O7 (NNPP) positive electrode] ASSBs by using a suitable sintering agent and analyzed the product by a combination of electrochemical and operando Raman spectroscopic methods. Significant irreversible capacity after the first cycle was confirmed by cyclic voltammetry. Microscopic operando Raman spectra were observed at the positive and negative electrodes and the electrolyte layer. Although the chemically stable NZSP layer did not show structural changes with a charge–discharge cycle, the spectra of the electrode active materials NNPP and NTP exhibited irreversible structural changes, which contributed to their large capacity losses. Operando spectroscopic techniques are an effective analytical tool for ASSBs owing to their physically separated sandwich structure and clear cross-section.

Bilayer Coating Composed of Starch and Methyl Cellulose-Nanoscale TiO2 for the Protection of Historic Paper from UV

Among the agents of deterioration considered particularly damaging to cultural heritage objects are light, ultraviolet (UV) and infrared. The high-energy UV is the most damaging of the three, as it can cause irreversible visual, chemical and structural changes in cellulose-based materials. Known for its photocatalytic properties, TiO2 can absorb UV and is thermally and chemically stable. In this study, we propose an innovative bilayer coating composed of starch, methyl cellulose and nano-TiO2 to utilize UV blocking properties of TiO2. The results of the treatments were assessed by determining physical, optical and surface properties, as well as the degradation degree of the samples, prior and post accelerated ageing. The results show that an increase in the weight concentration of TiO2 enhances the colour difference, but the colour of samples coated by lower concentrations of TiO2 after accelerated ageing is closer to the original value than the colour of the uncoated ones. An increase in both the contact angle and the absorption time is also present, but after ageing, both parameters significantly decrease due to the presence of TiO2. To conclude, the presented nanocomposite coating can protect historic paper from UV, but one should bear in mind that a higher weight concentration could lead to a higher water sensitivity after exposure to UV.

In vivo noninvasive mitochondrial redox assessment of the optic nerve head to predict disease.

Eye diseases are diagnosed by visualizing often irreversible structural changes occurring late in disease progression, such as retinal ganglion cell loss in glaucoma. The retina and optic nerve head have high mitochondrial energy need. Early mitochondrial/energetics dysfunction may predict vulnerability to permanent structural changes. In the in vivo murine eye, we used light-based resonance Raman spectroscopy (RRS) to assess noninvasively the redox states of mitochondria and hemoglobin which reflect availability of electron donors (fuel) and acceptors (oxygen). As proof of principle, we demonstrated that the mitochondrial redox state at the optic nerve head correlates with later retinal ganglion loss after acute intraocular pressure (IOP) elevation. This technology can potentially map the metabolic health of eye tissue in vivo complementary to optical coherence tomography, defining structural changes. Early detection (and normalization) of mitochondrial dysfunction before irreversible damage could lead to prevention of permanent neural loss.

Bronchoscopic Management of COPD and Advances in Therapy.

Chronic Obstructive Pulmonary Disease (COPD) is a highly prevalent and morbid disease marked by irreversible structural changes in the lungs. Bronchoscopic therapies have significantly expanded the treatment armamentarium for patients with persistent symptoms by reducing the physiologic detriments of hyperinflation in a less invasive fashion than surgical lung volume reduction. The spectrum of bronchoscopic techniques to reduce hyperinflation includes endobronchial valves, coils, thermal ablation, and biologic sealants. Other therapies focus on reducing parasympathetic tone and mucus hypersecretion and include targeted lung denervation, bronchial rheoplasty, and cryospray techniques. In this article, we will review the variety of techniques for bronchoscopic lung volume reduction, both established and investigational, along with their respective benefits and complications and will briefly review other investigational therapies for COPD.

Improvement in salt-tolerance of Aspergillus oryzae γ-glutamyl transpeptidase via protein chimerization with Aspergillus sydowii homolog

γ-Glutamyl transpeptidase is one of the key enzymes involved in glutamate production during high-salt fermentation of soy sauce and miso by koji mold, Aspergillus oryzae. However, the activity of γ-glutamyl transpeptidase from A. oryzae (AOggtA) is markedly reduced in the presence of NaCl, thus classifying it as a non-salt-tolerant enzyme. In contrast, the homologous protein from the xerophilic mold, A. sydowii (ASggtA) maintains its activity under high-salt conditions. Therefore, in this study, a chimeric enzyme, ASAOggtA, was designed and engineered to improve salt-tolerance in AOggtA by swapping the N-terminal region, based on sequence and structure comparisons between salt-tolerant ASggtA and non-salt-tolerant AOggtA. The parental AOggtA and ASggtA and their chimera, ASAOggtA, were heterologously expressed in A. oryzae and purified. The chimeric enzyme inherited the superior activity and stability from each of the two parent enzymes. ASAOggtA showed > 2-fold greater tolerance than AOggtA in the presence of 18% NaCl. In addition, the chimera showed a broader range of pH stability and greater thermostability than ASggtA. AOggtA and ASAOggtA were sy over the range pH 3.0 to pH 10.5. Thermal stability was found to be in the order AOggtA (57.5 °C, t1/2 = 32.5 min) > ASAOggtA (55 °C, t1/2 = 20.5 min) > ASggtA (50 °C, t1/2 = 12.5 min). The catalytic and structural characteristics indicated that non-salt-tolerant AOggtA would not undergo irreversible structural changes in the presence of NaCl, but rather a temporary conformational change, which might result in reducing the substrate binding and catalytic activity, on the basis of kinetic properties. In addition, the chimeric enzyme showed hydrolytic activity toward L-glutamine that was as high as that of AOggtA. The newly-designed chimeric ASAOggtA might have potential applications in high-salt fermentation, such as miso and shoyu, to increase the content of the umami-flavor amino acid, L-glutamate.

Lithium Trapping and Irreversible Atomic-Scale Structure Evolution during Delithiation of Silicon Oxides as Lithium-Ion Battery Anodes

Optimizing the oxygen content of silicon oxides used as anode materials for high-performance lithium-ion batteries is critical since it has diverse effects on lithium storage properties. However, the atomic-scale understanding of the effect of the oxygen content on structural evolution of the materials, particularly during delithiation is still limited. With this aim, we employ an iterative lithium extraction-relaxation algorithm based on reactive molecular dynamics simulations to investigate the dynamic processes of various silicon oxides. Our study highlights the effect of the oxygen content on various lithium storage properties, including the energetics of the interaction, lithium diffusion behaviors, lithium entrapment, structural reversibility during cycling, and mechanical properties. In particular, the simulations show that although increasing the oxygen content can significantly reduce the percentage of volume expansion during lithiation, which is a major cause of poor cycle retention of silicon- and silicon oxide-based anodes, this leads to an increased amount of the trapped lithium and an irreversible structural change during the reverse process. As contradictory conditions are required to achieve high specific capacity, long cycle life, and high coulombic efficiency, this atomistic study could provide a fundamental understanding beneficial for optimizing the oxygen content toward the development of silicon oxide-based anodes.

Dissipation Indicates Memory Formation in Driven Disordered Systems

Disordered and amorphous materials often retain memories of perturbations they have experienced since preparation. Studying such memories is a gateway to understanding this challenging class of systems. However, it often requires the ability to measure local structural changes in response to external drives. Here, we show that dissipation is a generic macroscopic indicator of the memory of the largest perturbation. Through experiments in crumpled sheets under cyclic drive, we show that dissipation transiently increases when first surpassing the largest perturbation due to irreversible structural changes with unique statistics. This finding is used to devise novel memory readout protocols based on global observables only. The general applicability of this approach is demonstrated by revealing a similar memory effect in a three-dimensional amorphous solid.

Partially Reversible Anionic Redox for Lithium-Excess Cobalt Oxides with Cation-Disordered Rocksalt Structure

Li-excess electrode materials potentially boost the energy density of Li-ion batteries, but the origin of the instability of anionic redox in cation-disordered rocksalt material is still under debate. In this study, a binary system of Li3NbO4–CoO is targeted as electrode materials for lithium storage applications. In this binary system, stoichiometric LiCo2/3Nb1/3O2 crystallizes into a rocksalt-type structure with partial ordering of Nb ions. Upon increase of the Li3NbO4 fraction, cation ordering is lost, forming a cation-disordered rocksalt structure in Li-excess phases. Although Li-excess Li4/3Co2/9Nb4/9O2 delivers a large reversible capacity as electrode materials, inferior cyclability and large voltage hysteresis for charge/discharge curves are noted. Irreversible structural changes in electrochemical cycles are also evidenced from results of in situ XRD measurements, suggesting that anionic redox is destabilized for Li4/3Co2/9Nb4/9O2. X-ray absorption spectroscopy reveals that partial stabilization of ligand holes as observed in SrCoO3 is achieved for these oxides. Ligand holes are more effectively stabilized for Li7/6Co4/9Nb7/18O2 with less Li-excess and Co-rich composition. Through systematic study of the binary system of Li3NbO4–CoO with different chemical compositions, factors affecting reversibility and irreversibility of anionic redox are further discussed.

Three-Dimensional Study of Polymer Composite Destruction in the Early Stages

The investigation of destruction processes in composite materials is a current problem for their structural application and the improvement of their functional properties. This work aimed to visualize structural changes induced in layered carbon fiber reinforced plastics (CFRP) with the help of synchrotron X-ray microtomography. This article presents the details of destructive processes in the early stages of the deformation of reinforced polymers under uniaxial stretching, investigated at the micro level. Individual structural elements of the composite-filaments, parallel fiber bundles, the nonuniformity of the polymer binder distribution, and continuity defects-were observed under an external load. We have considered the influence of the material architecture and technological defects on fracture evolution in cross-ply and quasi-isotropic fiber-reinforced plastics. The results indicate the sequence of irreversible structural changes before the destruction of the material.

Synthesis of Li1.20Mn0.432+Nb0.39O2 disordered rock-salt under reducing conditions for Li-ion batteries.

A Mn2+-Li-Nb disordered rock-salt oxide cathode is prepared by a solid-state reaction under 5% H2/N2, and its electrochemical property shows a high voltage plateau at 4.8 V, with irreversible structural changes in the 1st cycle due to O redox processes; this is supported by powder X-ray diffraction and ex situ laboratory Mn K-edge XANES data.

Molecular and Aggregate Structural, Thermal, Mechanical and Photophysical Properties of Long-Chain Amide Gelators Containing an α-Diketo Group in the Presence or Absence of a Tertiary Amine Group

Three structurally related gelators, each containing octadecyl chains, an α-diketo group at the 9,10 positions, and each with a different N-amide group-isobutyl (DIBA), isopentyl (DIPA) or N-(2-(dimethylamino)ethyl) (DMEA)-have been synthesized. Their neat structures as well as the thermal mechanical, and photophysical properties in their gel states with various liquids have been investigated. The gelator networks of DIBA and DIPA in octane, hexylbenzene and silicone oil consist of bundles of fibers. These gels are partially thixotropic and mechanically, thermally (to above their melting or silicone oil gelation temperatures), and photophysically stable. They are mechanically and thermally stronger than the gels formed with DMEA, the gelator with a tertiary amine group. The lone pair of electrons of the tertiary amine group leads to an intra-molecular or inter-molecular charge-transfer interaction, depending on whether the sample is a solution, sol, or gel. Neat, solid DMEA does not undergo the charge-transfer process because its amino and diketo groups are separated spatially by a large distance in the crystalline state and cannot diffuse into proximity. However, the solution of DIPA upon the addition of triethylamine becomes unstable over time at room temperature in the dark or (more rapidly) when irradiated, which initiates the aforementioned charge-transfer processes. The eventual reaction of the gelators in the presence of a tertiary amine group is ascribed to electron transfer from the lone-pair on nitrogen to an α-diketo group, followed by proton transfer to an oxygen atom on the anion radical of the α-diketo group from a methyl or methylene group attached to the nitrogen atom of the cation radical. Finally, the formation of an α-diketyl radical leads to irreversible electronic and structural changes that are observed over time.

470 MYOCARDIAL FIBROSIS IN ASYMPTOMATIC PATIENTS UNDERGOING SURGERY FOR MITRAL AND AORTIC VALVE REGURGITATION

Abstract Background Chronic heart valve regurgitation induces left ventricular (LV) volume overload, leading to the development of hypertrophy and progressive dilatation of the ventricle to maintain physiological cardiac output. In order to prevent potential irreversible LV structural changes, the identification of the best timing for treatment is pivotal. Objective To assess the presence and extent of fibrosis in myocardial tissue in asymptomatic patients with valvular heart disease (VHD) and preserved LV dimensions and function undergoing cardiac surgery. Methods Thirty-nine patients were enrolled. Sixteen patients were affected by aortic or mitral regurgitation: they were all asymptomatic, undergoing valve surgery according to VHD European Society of Cardiology guidelines. Twentythree patients with end-stage nonischemic dilated cardiomyopathy (DCM) and severe LV dysfunction undergoing cardiac surgery for implantation of a durable left ventricular assist device (LVAD) served as controls. During surgery, VHD patients underwent three myocardial biopsies at the level of the septum, the lateral wall and LV apex, while in LVAD patients the coring of the apex of the LV was used. For both groups, the tissue samples were analyzed on one section corresponding to the apical area. All slides were stained with hematoxylin and eosin and Masson's trichrome staining and further digitalized. The degree of fibrosis was then calculated as a percentage of the total area. Results Of 39 patients, 23 met the inclusion criteria: 12 had mitral or aortic insufficiency with a preserved ejection fraction and 11 had idiopathic dilated cardiomyopathy. Quantitative analysis of apical sections revealed a myocardial fibrosis amount of 10±6% in VHD patients, while in LVAD patients the mean apical myocardial fibrosis rate was 38±9%. In VHD patients, fibrosis was also present in the lateral wall (9±4%) and in the septum (9±6%). Conclusion Our case series study highlights the presence of tissue remodeling with fibrosis in asymptomatic patients with VHD and preserved LV function. According to our results, myocardial fibrosis is present at an early stage of the disease, well before developing detectable LV dysfunction and symptoms. Since the relationship between the progressive magnitude of myocardial fibrosis and potential prognostic implications are not yet defined, further studies on this topic are warranted.

Optimized ACE2 decoys neutralize antibody-resistant SARS-CoV-2 variants through functional receptor mimicry and treat infection in vivo.

As severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) evolves to escape natural antibodies, it also loses sensitivity to therapeutic antibody drugs. By contrast, evolution selects for binding to ACE2, the cell-surface receptor required for SARS-CoV-2 infection. Consistent with this, we find that an ACE2 decoy neutralizes antibody-resistant variants, including Omicron, with no loss in potency. To identify design features necessary for in vivo activity, we compare several enzymatically inactive, Fc effector-silenced ACE2-Fc decoys. Inclusion of the ACE2 collectrin-like domain not only improves affinity for the S protein but also unexpectedly extends serum half-life and is necessary to reduce disease severity and viral titer in Syrian hamsters. Fc effector function is not required. The activity of ACE2 decoy receptors is due, in part, to their ability to trigger an irreversible structural change in the viral S protein. Our studies provide a new understanding of how ACE2 decoys function and support their development as therapeutics to treat ACE2-dependent coronaviruses.

Spatiotemporal tracking of small extracellular vesicle nanotopology in response to physicochemical stresses revealed by HS-AFM.

Small extracellular vesicles (sEVs) play a crucial role in local and distant cell communication. The intrinsic properties of sEVs make them compatible biomaterials for drug delivery, vaccines, and theranostic nanoparticles. Although sEV proteomics have been robustly studied, a direct instantaneous assessment of sEV structure dynamics remains difficult. Here, we use the high-speed atomic force microscopy (HS-AFM) to evaluate nanotopological changes of sEVs with respect to different physicochemical stresses including thermal stress, pH, and osmotic stress. The sEV structure is severely altered at high-temperature, high-pH, or hypertonic conditions. Surprisingly, the spherical shape of the sEVs is maintained in acidic or hypotonic environments. Real-time observation by HS-AFM imaging reveals an irreversible structural change in the sEVs during transition of pH or osmolarity. HS-AFM imaging provides both qualitative and quantitative data at high spatiotemporal resolution (nanoscopic and millisecond levels). In summary, our study demonstrates the feasibility of HS-AFM for structural characterization and assessment of nanoparticles.

Voltage Oscillations during Anodic Polarization of Zinc in Water Solutions of NaOH

The present brief research deals with the appearance of voltage oscillations during galvanostatic anodization of Zn in the NaOH electrolyte. Hence, this research aims to describe the observed voltage oscillations, giving the most probable explication for their occurrence. Following previous results, the anodization was performed at 30 or 50 mA•cm-2 in diluted 0.002 M NaOH aqueous solution for 100 or 240 s at room temperature. The respective voltage alterations were recorded and submitted for further analysis. The obtained curves and the probable reasons for the observed voltage oscillations were analyzed in detail. The main research result has become a concept for the correlation between the oscillations and the alteration of the growing layer resistivity. This suggests that the resistivity alters due to local heating effects inside the film. These effects probably cause irreversible structural changes in the bulk of the growing film, obviously related to the occurrence of oxygen vacations. In this sense, this study initiates an entirely new field of investigation regarding the phenomena related to the Zn anodization in alkaline media at high current densities.

LANDING GEAR FAILURES CONNECTED WITH HIGH-PRESSURE HOSES AND ANALYSIS OF TRENDS IN AIRCRAFT TECHNICAL PROBLEMS

Reliability and maintenance analysis in aviation industry focused on a main objective of the accident and incident investigations what are help to better understand the causes of accidents. In the article suggested the underlying concept by scorecard of situations what lead to aviation accidents. In the present research, the aviation accident connected with a landing gear and a problem of failure to follow maintenance instructions during a maintenance on aircraft landing gear hydraulic drive was under an investigation, on an example of root cause analysis of the failure of hydraulic flexible highpressure hoses. The approach presented in this research of experimental measurements, based on fluid pressure measuring, high-pressure hoses vibration measuring and frequency’s analysis. By spectrum analyses was found that high-pressure hoses are most susceptible to deformation at frequencies to the response of the fluid within, as well as at hoses material resonance frequencies. The compact version of hoses is more deformational on the resonance points than a standard version of hose. In final according to analyses, was established that disrespect of the frequency conditions was leaded to causes irreversible degradation changes of the hose inner structure and occurrence of material defects inside layers contact what lead in final step to hose failure.

In Situ Multi-Modal Approach for Electrode-Electrolyte Interfacial Chemistryand Electrode and Electrolyte Aging Behavior Studies

Increasing demands for cost-effective electric vehicles and electrochemical energy storage systems require advanced secondary batteries with higher energy density, longer lifetime, and enhanced safety. Increase of the battery operating voltage is one realistic strategy to extend the energy density, but it is accompanied by irreversible structural changes to the electrodes and parasitic reactions within an electrode-electrolyte interphase resulting in capacity fading and subsequent battery failure. Therefore, a fundamental understanding of underlying electrochemical mechanisms in the electrodes during battery cycling is critical for the development of next-generation secondary batteries.Based on our previous studies utilizing in situ surface-enhanced Raman spectroscopy to monitor the evolution of the Si-electrolyte interphase1 and in situ ATR-FTIR to investigate the voltage dependent electrolyte solution structure changes at the interface, transition metal redox chemistry, and cathode/electrolyte interfacial layer evolution,2 recently we updated the in situATR-FTIR with a newly designed ‘full-cell’ that enables us to analyze the interfacial reactions and interactions on the surfaces of both electrodes that directly influence battery performance, lifetime, and safety. Specifically, we focus on transition metal complex formation and its effect on solid-electrolyte interphase (SEI) formation and evolution on the anode due to transition metal dissolution and crosstalk of Mn-rich cathodes at high voltages (≥4.4 V).In addition, using our multi-modal characterization—a combination of in situ gas chromatography with flame ionization detection (GC-FID) and in situ ATR-FTIR—(electro)chemical degradation of the electrolyte is correlated with gas evolution in the battery. For example, GC-FID measures increasing amounts of ethylene gas until the end the first charging cycle of a LiNiO2//Graphite cell with Gen2 electrolyte (LiPF6 in ethylene carbonate (EC):ethyl methyl carbonate (EMC), 3:7 wt.%). Concurrently, in situ ATR-FTIR shows decreasing concentration of EC solvent, as calculated from the FTIR intensity of EC vibrational absorption. Ethylene is a known by-product of ethylene carbonate electrochemical reduction and is produced during SEI formation.3 Quantifying multiphase reactions occurring during battery operation is critical to understanding and mitigating battery degradation pathways, and developing next-generation battery materials systems.

Electrochemical Analyses of Redox-Active Minerals: Insights and Persisting Challenges

Redox-active minerals often have complex electrochemical properties that are difficult to quantify and explain. Quantification is difficult because many redox-active minerals are poorly conductive, prone to dissolution, and capable of undergoing reversible and irreversible structural changes during redox cycling. Explaining a mineral's electrochemical properties is frequently challenging because minerals can undergo complex ion transport processes in their structures and undergo charge redistribution processes that occur within the crystal lattice on long time scales. In this talk, I will present the insights I have gained from studying environmentally relevant iron- and manganese-bearing minerals over the past 15 years. The presentation will include how electrochemical analyses can be used to quantify the thermodynamic properties of minerals and how these properties relate to their redox reactivities with environmentally relevant phases. The talk will also cover persisting challenges that exist in this field.

(Digital Presentation) Lifetime Prediction of SiC Power Module By Using Time-Series Analysis of Acoustic Emission during Power Cycling Test

Acoustic emission (AE) based condition monitoring is a popular method to inspect a material health condition in many areas[1]. It monitors irreversible structure changes of material through radiation of acoustic waves. Typically, the structure change generates a typical spectrum of acoustic waves starting at 1 kHz, and falling off at several MHz, which can be detected and analyzed via an AE system. Meanwhile, AE signals convey massive information such as rise time, AE energy, AE peak frequency, which are expressive of the failure process. AE based condition monitoring technology exhibits excellent capability of detecting, positioning, and characterizing damage and has been wildly used in monitoring of inner structure changes in bridges, pressure containers, and pipeline systems. In the last decade, the AE technology has been applied to condition monitoring of power modules and shows a promising application scenario in the power electronics field, which help us acquire accurate failure information and making precise perdition of a failure in the power module[2].In this work, we firstly combined the AE monitoring and a deep learning model - Gated Recurrent Unit (GRU) to monitor and predict the failure of power module as shown in Figure 1[3]. The proposed method integrally analyzes and summarizes the patterns from the time-series data obtained during power cycle tests of power modules and predicts the failures. Specifically, the time-series data consisting of junction temperature, electric power, thermal resistance, and several AE parameters were obtained from AE sensor data and power cycling test. The proposed method (a) automatically extracts common or different time-series patterns among devices and estimates device states, and (b) effectively predicts failures by switching prediction models according to changes in device states.By time-series analysis of AE sensor data, it was confirmed that the AE parameters obtained from the AE sensor data capture the progression and signs of failures. In addition, by verifying the effectiveness of the time-series pattern detection, it was confirmed that the proposed method can accurately extract the timeseries patterns during normal conditions, the time-series patterns that show signs of failure, and the time-series patterns after failure. Furthermore, by verifying the prediction accuracy and learning efficiency, it was showed that the proposed method is capable of faster learning while retaining the same or better performance compared to existing methods. Reference [1] A. Nair and C. Cai, "Acoustic emission monitoring of bridges: Review and case studies," Eng Struct, vol. 32, no. 6, pp. 1704-1714, 2010.[2] S. Müller, C. Drechsler, U. Heinkel, and C. Herold, "Acoustic emission for state-of-health determination in power modules," in 2016 13th International Multi-Conference on Systems, Signals & Devices (SSD), 2016: IEEE, pp. 468-471.[3] R. Dey and F. M. Salem, "Gate-variants of gated recurrent unit (GRU) neural networks," in 2017 IEEE 60th international midwest symposium on circuits and systems (MWSCAS), 2017: IEEE, pp. 1597-1600.

Bragg Coherent Diffraction Imaging Studies of Pt Nanograins Under Electrochemical Control Using Pipette Cells

Deeply penetrating X-rays are well suited to investigate the electrochemical systems and interfaces under in-situ / operando environments. In particular, a recently developed X-ray Bragg Coherent Diffractive Imaging (BCDI) is a powerful tool for 3D imaging of internal structures of nano-size particles, [1,2] and the internal compositions of alloy nanoparticles. [3-5] Further, the well-annealed alloy nanoparticles can be electrochemical treated to increase the surface strain and to enhance the certain electrocatalytic activities such as oxygen reduction reaction (ORR). [6] After introduction of the technique and examples, we will focus on how strain in a single Pt nano-grain evolves in response to applied potential. The strain responses then will be discussed within the context of surface oxidation and oxygen-evolution reaction (OER).For Pt nanograins of a film grown on a substrate, the strain response is tightly related to the place-exchange surface oxidation and electrochemical double layer to the applied potential range relevant to OER. During polarization, marked changes in surface strain arise from the Coulombic attraction between the electrode surface and electrolyte ions, while the strain in the bulk of the crystal remained unchanged. The concurrent surface redox reactions have a strong influence on the magnitude and nature of the strain dynamics under polarization.In careful BCDI analyses, we found that only the top 10 nm of Pt at the grain/electrolyte interface responded sensitively to applied potential, while a much more muted response was observed for the remainder of the bulk Pt grain. The potential-dependent strain responses were not present at grain boundaries locked to the neighbor grains and at the bottom interface in contact to the substrate, neither of which were exposed to electrolyte. Our measurements further suggested that even highly stable electrodes such as Pt are subject to irreversible structural changes during polarization, highlighting the importance of in-situ/operando techniques to draw faithful structure-activity relationships in electrochemistry. These observations were possible due to the high strain sensitivity of BCDI combined with the near-zero X-ray scattering background of the submicron scale nanopipette electrochemical cell.[1] Y. Liu et al., Nano Letters 17, 1595 (2017).[2] W. Cha, Y. Liu, H. You, G. B. Stephenson, and A. Ulvestad, Advanced Functional Materials 27, 1700331 (2017).[3] T. Kawaguchi et al., Physical Review Letters 123, 246001 (2019).[4] T. Kawaguchi, W. Cha, V. Latyshev, S. Vorobiov, V. Komanicky, and H. You, Journal of the Korean Physical Society 75, 528 (2019).[5] S. Choi et al., Nano Letters 20, 8541 (2020).[6] T. Kawaguchi, V. Komanicky, V. Latyshev, W. Cha, E. R. Maxey, R. Harder, T. Ichitsubo, and H. You, Nano Letters 21, 5945 (2021).