High Magnification Research Articles

Strong-lensing Analysis of SPT-CL J2325−4111 and SPT-CL J0049−2440, Two Powerful Cosmic Telescopes (RE > 40″) from the SPT Clusters Sample

Abstract We report the results from a study of two massive (M 500c > 6.0 × 1014 M ⊙) strong-lensing clusters selected from the South Pole Telescope cluster survey for their large Einstein radius (R E > 40″), SPT-CL J2325−4111 and SPT-CL J0049−2440. Ground-based and shallow Hubble Space Telescope (HST) imaging indicated extensive strong-lensing evidence in these fields, with giant arcs spanning 18″ and 31″, respectively, motivating further space-based imaging follow-up. Here, we present multiband HST imaging and ground-based Magellan spectroscopy of the fields, from which we compile detailed strong-lensing models. The lens models of SPT-CL J2325−4111 and SPT-CL J0049−2440 were optimized using nine and eight secure multiply imaged systems with a final image-plane rms of 0 . ″ 63 and 0 . ″ 73, respectively. From the lensing analysis, we measure a projected mass density within 500 kpc of M(<500 kpc) = (7.30 ± 0.07) × 1014 M ⊙ and M ( < 500 kpc ) = 7.1 2 − 0.19 + 0.16 × 1 0 14 M ⊙ for these two clusters, and subhalo mass ratios of 0.12 ± 0.01 and 0.2 1 − 0.05 + 0.07 , respectively. Both clusters produce a large area with high magnification (μ ≥ 3) for a source at z = 9, A | μ | ≥ 3 lens = 4.9 3 − 0.04 + 0.03 arcmin2 and A | μ | ≥ 3 lens = 3.6 4 − 0.10 + 0.14 arcmin2, respectively, placing them in the top tier of strong-lensing clusters. We conclude that these clusters are spectacular sightlines for further observations that will reduce the systematic uncertainties due to cosmic variance. This paper provides the community with two additional well-calibrated cosmic telescopes, as strong as the Frontier Fields and suitable for studies of the highly magnified background Universe.

Ex Vivo Endocytoscopic Evaluation of Pancreatobiliary Cancers: A Step Toward Real-time In Vivo Diagnosis.

Endocytoscopy (EC) enables real-time diagnosis at extremely high magnification. The aim of the present study was to assess the potential of EC for the prediction of biliary malignancy. In total, 23 surgically resected cases with biliary tract cancer (BTCA, n=6), pancreatic head cancer (PCA, n=13), and non-cancerous bile duct lesion (NCBL, n=4) were enrolled in the study. The extrahepatic bile duct mucosa of the resected materials was examined ex vivo using EC. In cases of BTCA and PCA with bile duct invasion, several independent findings were identified as predictors of cancerous areas using multivariate analysis. These include, extravasation [odds ratio (OR)=15.91; 95% confidence interval (CI)=2.05-123.46], absence of fine network (OR=6.16; 95%CI=1.88-20.19), vascular dilatation (OR=4.87; 95%CI=1.56-15.25) in direct view. Additional predictors observed under methylene blue staining include anisonucleosis (OR=27.77; 95%CI=6.85-112.56), absence of large glands (OR=27.77; 95%CI=6.85-112.56), obscured nuclei (OR=7.63; 95%CI=2.23-26.17), and absence of uniform glands and small/irregular glands (OR=6.18; 95%CI=2.25-16.98). There were no differences in EC findings of non-cancerous areas between BTCA/PCA and NCBL. EC score for predicting the cancerous area (ECS-CA) was established by summing the scores (regression coefficients) of the eight EC findings described above. In the receiver operating characteristic curve analysis, the area under the curve for predicting cancerous areas using the ECS-CA was 0.960 (optimal cut-off ECS-CA, 6.1; sensitivity 91.5%; specificity, 93.6%). ECS-CA is valuable for assisting in the real-time diagnosis of biliary malignancy in vivo.

Cross-scale backscattered-electron imaging and its application in revealing the microstructure-property relations

Scanning electron microscopy (SEM) has been widely utilized in the field of materials science due to its significant advantages, such as large depth of field, wide field of view, and excellent stereoscopic imaging. However, at high magnification, the limited imaging range in SEM cannot cover all the possible inhomogeneous microstructures. In this research, we propose a novel approach for generating high-resolution SEM images across multiple scales, enabling a single image to capture physical dimensions at the centimeter level while preserving submicron-level details. We adopted the SEM imaging on the AlCoCrFeNi2.1 eutectic high entropy alloy as an example. SEM videos and image stitching are combined to fulfill this goal, and the video-extracted low-definition images are clarified by a well-trained denoising model. Furthermore, we segment the macroscopic image of the eutectic high entropy alloy, and the area of various microstructures is distinguished. By combining the segmentation results and hardness experiments, we found that the hardness is positively correlated with the content of the body-centered cubic phase and negatively correlated with the lamella width. The whole procedure is also applied to a thermoelectric gradient material (PbSe-SrSe). Our work provides a feasible solution to generate macroscopic images based on SEM for further analysis of the correlations between the microstructures and spatial distribution, and can be widely applied to other types of microscopes.

Barley leaf cell-wall responses to the penetration by adapted and nonadapted powdery mildew fungi revealed with the thermal-source based Fourier transform infrared microspectroscopy and focal plane array

Infrared microspectroscopy allows for detailed characterization of functional groups at subcellular levels in plants. In this study, barley leaves were inoculated with Blumeria graminis f. sp. hordei (Bgh, adapted) and B. graminis f. sp. tritici (Bgt, nonadapted). Globar-based transmission Fourier transform infrared (gFTIR) microspectroscopy equipped with an upgraded high-resolution focal plane array (FPA) detector which enabled the rapid acquisition of high magnification imaging with a 3.3-μm × 3.3-μm capacity, was employed to quantitatively analyse the cell wall (CW) modification over individual leaf cells in response to attempted penetration at 24 hours post-inoculation. Univariate and multivariate analyses of gFTIR spectra revealed distinct changes in several CW functional groups upon attempted penetration by Bgt, with significant increases in the integrated areas of cellulose, hemicellulose, methyl-esterified pectins and lipid regions compared to cells without penetration. Notably, neither guaiacyl (G) nor syringyl (S) lignin increased significantly in CWs near Bgt penetration sites relative to nonpenetrating controls, though the G/S ratio was higher than in Bgh-penetrated sites. These findings suggest early and rapid CW modifications occur during the nonhost resistance to Bgt. This study also confirms previous results obtained using synchrotron-based FTIR (sFTIR), demonstrating that both gFTIR and sFTIR are valuable for studying plant CW apposition, with gFTIR being more accessible and rapid for imaging over large areas with compatible quality and resolution to sFTIR.

What is the nature of GW230529? An exploration of the gravitational lensing hypothesis

Abstract On the 29th of May 2023, the LIGO–Virgo–KAGRA Collaboration observed a compact binary coalescence event consistent with a neutron star – black hole merger, though the heavier object of mass 2.5 − 4.5 M⊙ would fall into the purported lower mass gap. An alternative explanation for apparent observations of events in this mass range has been suggested as strongly gravitationally lensed binary neutron stars. In this scenario, magnification would lead to the source appearing closer and heavier than it really is. Here, we investigate the chances and possible consequences for the GW230529 event to be gravitationally lensed. We find this would require high magnifications and we obtain low rates for observing such an event, with a relative fraction of lensed versus unlensed observed events of 2 × 10−3 at most. When comparing the lensed and unlensed hypotheses accounting for the latest rates and population model, we find a 1/58 chance of lensing, disfavoring this option. Moreover, when the magnification is assumed to be strong enough to bring the mass of the heavier binary component below the standard upper limits on neutron star masses, we find high probability for the lighter object to have a sub-solar mass, making the binary even more exotic than a mass-gap neutron star–black hole system. Even when the secondary is not sub-solar, its tidal deformability would likely be measurable, which is not the case for GW230529. Finally, we do not find evidence for extra lensing signatures such as the arrival of additional lensed images, type-II image dephasing, or microlensing. Therefore, we conclude it is unlikely for GW230529 to be a strongly gravitationally lensed binary neutron star signal.

Mapping mitochondrial morphology and function: COX-SBFSEM reveals patterns in mitochondrial disease

Mitochondria play a crucial role in maintaining cellular health. It is interesting that the shape of mitochondria can vary depending on the type of cell, mitochondrial function, and other cellular conditions. However, there are limited studies that link functional assessment with mitochondrial morphology evaluation at high magnification, even fewer that do so in situ and none in human muscle biopsies. Therefore, we have developed a method which combines functional assessment of mitochondria through Cytochrome c Oxidase (COX) histochemistry, with a 3D electron microscopy (EM) technique, serial block-face scanning electron microscopy (SBFSEM). Here we apply COX-SBFSEM to muscle samples from patients with single, large-scale mtDNA deletions, a cause of mitochondrial disease. These deletions cause oxidative phosphorylation deficiency, which can be observed through changes in COX activity. One of the main advantages of combining 3D-EM with the COX reaction is the ability to look at how per-mitochondrion oxidative phosphorylation status is spatially distributed within muscle fibres. Here we show a robust spatial pattern in COX-positive and intermediate-fibres and that the spatial pattern is less clear in COX-deficient fibres.

Time-varying quantitative characterization of reservoir microscopic pore structure based on digital core

The reservoir physical parameters (such as porosity, permeability, phase permeability, etc.) will change in the process of water injection development with the continuous flushing effect of high magnification water drive, which may have adverse effects on development if they cannot be accurately characterized. In this paper, we try to quantitative characterize the time -varying features of pore structure from the microscopic perspective. We used high-resolution 3D micro-CT (MCT) images to supplement the analysis of the physical properties of the rocks, and we used 3D pore network modeling technology to generate a 3D model of the rock samples. Then the relevant static micro-pore parameters are derived to study the changes of rock properties in different periods of development. Pore parameters were obtained to study the changes in porosity, permeability and pore size distribution of the rocks under different expulsion multiples, and to visualize the time-varying pattern of the microstructure of the rock samples under different stages of water injection. Under low-multiple water-driven conditions (10 PV), the physical properties of the rock samples did not change significantly, with an average facies change of only 1.98%. When reaching high multiples of water drive (more than 500PV), the change rate reaches more than 15%. And with the increase of water drive multiples, the distribution of pore radius and throat radius of rock samples showed an obvious right-shift trend, and the pores and throats increased, which was consistent with the results of CT scanning photographs. Equation fitting of the simulation results reveals that the core micro-parameters show an overall logarithmic relationship with the change of water drive. In this paper, a new application of Micro CT is provided to quantify the microstructure of water-injected reservoirs. By adopting this method, the effect of water-drive multiplicity on reservoir structure can be illustrated from a microscopic perspective. Meanwhile, compared with previous studies, this paper further investigates the effect of time-variation based on the qualitative analysis of the effect of time-variation of water-driven in reservoirs, and regresses time-variation curves and formulas through the changes in multiple water-driven states, which fills in the gap of the current lack of quantitative research and provides new understanding and optimization of the development of oilfields. The study will provide a new perspective for understanding and optimizing oilfield development.

Apicoectomy: A review of clinical concepts and techniques

Apicoectomy is the surgical approach for preserving a tooth with a large periapical lesion which may not be treated with traditional therapy. The goal of apicoectomy is to seal off the root canal system, promoting healing by establishing a barrier between the irritants inside the canal and the periapical tissue. Apicoectomy is a predictable, less expensive alternative to tooth extraction and replacement when done after proper case selection. Locating areas in the root apex that have not been sealed and then appropriately sealing the root apex are crucial steps in apicoectomy. The effectiveness of surgical endodontic therapy has increased as a result of the application of microsurgical tools and techniques. Using a surgical microscope during an apicoectomy is recommended because it provides superior focused illumination of microstructures and enables clear view of the operative field with high magnification. Moreover, lasers and guided microsurgery in apicoectomy provide enhanced periapical healing with a favorable long-term prognosis. The current review describes basic concepts and advanced techniques used for apicoectomy.

Mitochondrial Morphofunctional Profiling in Primary Human Skin Fibroblasts Using TMRM and Mitotracker Green Co-staining.

Mitochondrial morphology and membrane potential (Δψ) are important readouts of mitochondrial function. Integrated analysis of these parameters in living cells can be performed using fluorescent lipophilic cations, which enter cells and accumulate in the mitochondrial matrix in a Δψ-dependent manner. Here, we describe the use of tetramethylrhodamine methyl ester (TMRM) and Mitotracker Green FM (MG) for mitochondrial morphology and semiquantitative Δψ analysis in living primary human skin fibroblasts (PHSFs). Practically, we present an integrated protocol to quantify mitochondrial morphology parameters and signal intensity using epifluorescence microscopy of PHSFs co-stained with TMRM and MG. This approach performs best using large flat cells like PHSFs, which display a high mitochondria-specific fluorescence signal and are imaged at a relatively high (x40) magnification.

Self-template impregnated silver nanoparticles in coordination polymer gel: photocatalytic CO2 reduction, CO2 fixation, and antibacterial activity.

CO2 fixation and light-assisted conversion of CO2 in the presence of water into fuels and feedstocks are clean and sustainable techniques to alleviate the energy crisis and global climate change. In this regard, herein, a waterborne multifunctional metal-organic coordination polymer gel (Ag@GMP) was prepared from silver nitrate and guanosine 5'-monophosphate. Electron microscopy exhibits that Ag@GMP has a flower-like structure, which is composed of vertically grown sheets, and corresponding high magnification images display the presence of silver nanoparticles on the vertically grown sheets. Ag@GMP demonstrates remarkable photocatalytic performance, achieving a CO2 conversion rate of 18.6 μmol g-1 with approximately 85% selectivity towards CO at ambient temperature without using sacrificial agents. In situ diffuse reflectance infrared Fourier transform spectroscopy was employed to elucidate the proposed mechanism for photocatalytic CO2 reduction. Additionally, Ag@GMP exhibits significant catalytic activity in the fixation of CO2 with epoxides, leading to the formation of valuable chemicals under atmospheric pressure. Ag@GMP demonstrated efficient antibacterial activity against both Gram-negative and Gram-positive bacteria. The highest zone of inhibition was observed against S. aureus MTCC 3160 (15.83 ± 1.1 mm), and for E. coli, P. aeruginosa PAO1, and B. subtilis, it was found to be 12.66 ± 0.9, 14.33 ± 0.8 and 12.8 ± 0.8 mm, respectively.

Explanations for the two-component spectral energy distributions of gravitationally lensed stars at high redshifts

Observations of gravitationally lensed, high-mass stars at redshifts $ occasionally reveal spectral energy distributions that contain two components with different effective temperatures. Given that two separate stars are involved, it suggests that both stars have simultaneously reached very high magnification, as expected for two stars in a binary system close to the caustic curve of the foreground galaxy-cluster lens. The inferred effective temperatures and luminosities of these stars are, however, difficult to reconcile with known binaries, or even with isolated stars of the same age. Here, we explore three alternative explanations for these cases: circumstellar dust around the cooler of the two stars; age differences of a few Myr among stars in the same star cluster, and a scenario in which the stars originate in two separate star clusters of different age along the lensing caustic. While all of these scenarios are deemed plausible in principle, dust solutions would require more circumstellar extinction than seen in local observations of the relevant super/hypergiant stars. Hence, we argue that age differences between the two stars are the most likely scenario, given the current data.

Workflow automation of SEM acquisitions and feature tracking.

Acquiring multiple high magnification, high resolution images with scanning electron microscopes (SEMs) for quantitative analysis is a time consuming and repetitive task for microscopists. We propose a workflow to automate SEM image acquisition and demonstrate its use in the context of nanoparticle (NP) analysis. Acquiring multiple images of this type of specimen is necessary to obtain a complete and proper characterization of the NP population and obtain statistically representative results. Indeed, a single high magnification image only scans a small area of sample, containing only few NPs. The proposed workflow is successfully applied to obtain size distributions from image montages at three different magnifications (20,000x, 60,000x and 200,000x) on the same area of the sample using a Python based script. The automated workflow consists of sequential repositioning of the electron beam, stitching of adjacent images, feature segmentation, and NP size computation. Results show that NPs are best characterized at higher magnifications, since lower magnifications are limited by their pixel size. Increased accuracy of feature characterization at high magnification highlights the importance of automation: many high-magnification acquisitions are required to cover a similar area of the sample at low magnification. Therefore, we also present feature tracking with smart beam positioning as an alternative to blind acquisition of very large image arrays. Feature tracking is achieved by integrating microscope tasks with image processing tasks, and only areas of interest will be imaged at high resolution, reducing total acquisition duration.

Microstructure degradation and creep failure study of the dissimilar metal welded joint of heat-resistant steel and Inconel 617 alloy tested at 650 °C and applied stress range of 100–150 MPa

The advanced ultra-supercritical (A-USC) power plant system is anticipated to become India's next-generation base-load power station. To adopt AUSC technology, dissimilar welded joints (DWJs) between heat-resistant steels and the nickel-based alloys, using the nickel-based fillers, will need to be implemented. However, failure of dissimilar welded joints from P92 steel base metal or the heat affected zone (HAZ) has been commonly observed under high-temperature creep conditions. In the present study, the creep rupture behaviours and rupture mechanisms of DWJ between the Ni-based alloy Inconel 617 and heat-resistant P92 steel with Inconel 617 (ERNiCrCoMo-1) filler metal were investigated. Creep tests were conducted at 650 °C in the stress range of 100–150 MPa. To examine the creep rupture behaviour of the DWJ samples, optical microscopy (OM), scanning electron microscopy (SEM) and microhardness tests were performed. Cross-sectional images of the fractured creep specimens tested under various operating conditions revealed failures originating from distinct locations, including the P92 base metal and the inter-critical heat affected zone (HAZ). The specimen tested at 650 °C/150 MPa exhibited failure originating from the P92 base metal, whereas the specimen tested at 650 °C under the stress range of 100–130 MPa showed failure from the inter-critical heat affected zone (ICHAZ). The failure from P92 BM was primarily governed by plastic deformation, with the growth and coalescence of dimples ultimately resulting in trans-granular fracture. The specimens tested at 650 °C/100–130 MPa, which failed from the ICHAZ, exhibited a typical Type IV inter-granular failure. This failure mode is primarily attributed to matrix softening in HAZ, weakening of the boundaries, coarsening of the precipitates, and the evolution of intermetallic Laves phases. The specimen that failed in the stress range of 100–130 MPa exhibited a high density of microvoids in the ICHAZ, along with a few microvoids in the FGHAZ. The weld metal showed negligible degradation in microstructure, while the hardness study revealed a significant increase in hardness with an increase in rupture time, i.e., a decrease in applied stress and it was attributed to evolution of the new carbide phases in weld metal. Coarsening of the carbide precipitates was observed in each zone of the HAZ of P92 steel as well as in the base metal. The EDS study of the fracture tip and the FGHAZ/ICHAZ of the specimen that failed under stresses of 100 MPa and 120 MPa confirmed the evolution of intermetallic Laves phases. High magnification SEM images confirmed that triple boundaries are preferential locations for microvoid nucleation. The failed specimen showed the presence of microvoids near the carbide precipitates, with a large density of both coarse and fine precipitates confirmed all around and inside the microvoids. The ICHAZ and FGHAZ confirmed the formation of fine prior austenite grain boundaries (PAGBs) during the welding thermal cycle, which exhibited a lower density of carbide precipitates and this played a major role in Type IV failure.

(Digital Presentation) Experimental Analysis of Pit Initiation at MnS Inclusion in Low-Alloy Steel Using in-Situ Raman Spectroscopy

Low-alloy steel is an indispensable material for industry and infrastructure and is widely used in many fields because it can save cost and elemental resources. However, one of the disadvantages of low-alloy steel is its limited corrosion resistance compared to that of high alloys. Specifically, a major weakness is its high susceptibility to pitting in an environment containing Cl- ions. MnS inclusions are well known as preferential pitting sites because of its poor stability against chemical dissolution and ease of deformation by rolling. A lot of studies have investigated the mechanisms of pit initiation at MnS so far. Some detail analyses revealed that S species such as S2O3 2-, HS- and elemental S were generated due to dissolution of MnS, and they were harmful to pit initiation and active dissolution. However, these studies did not focus on ‘when’ those S species were generated. In addition, most of these previous studies focused on pitting in high alloys such as stainless steel and Ni-based alloy, so the mechanism of pit initiation in low-alloy steel is not yet fully understood.This study aims to clarify the chronology between MnS dissolution, S species generation and pit initiation in low-alloy steel. The microscopic potentiodynamic polarization test was carried out in 20 mM NaCl added boric-borate buffer solution at pH 8.0. To analysis S species dissolved from MnS inclusions during the electrochemical test, in-situ observation using an optical microscope with high magnification and Raman spectroscopy were employed.The polarization curve started at cathodic region, and then the corrosion potential was observed. In the anodic region, active dissolution and passive regions appeared in the curve as the potential increased. Finally, surges in the current density, attributed to pit initiation, was observed. In-situ observation ascertained that pit initiated at MnS inclusion whose longer diameter was 20 µm. Interval analysis of Raman spectroscopy during the test detected elemental S about 0.1 V below the pitting potential.Analysis of the test solution after the polarization test also detected elemental S, although other S species such as S2O3 2- and HS- were not detected.To confirm the morphology of the pit, cross-sectional observation was carried out using FIB/SEM. The pit was found to grow hemispherically, and corrosion product composed by Fe, Mn, O, and S was formed on the inner wall of the pit.This study clarified that, MnS started to dissolve 0.1 V below the pitting potential. Then, elemental S was formed and concentrated in the vicinity of MnS inclusion. After elemental S concentrated enough to accelerate pit initiation, the active dissolution at the interface between MnS inclusion and steel matrix occurs rapidly to form pit. A part of elemental S deposited on the inner surface of the pit and form oxysulfide of Fe and Mn as corrosion product.

Influence of Phosphorus on Initial and Long-Term Atmospheric Corrosion Behavior of Steel Materials

Phosphorus is contained as an impurity in the manufacturing process of steel materials, and it is known to be difficult to remove it completely, and it is also thought to influence the corrosion resistance of steel materials. However, the effect of phosphorus on corrosion resistance has not been clarified, because the steel materials used in previous research reports also contain copper and chromium. The aim of the present study was to systematically examine the influence of phosphorus on the corrosion behavior from early to long-term.Fe-P binary alloys containing 0.5, 1.0 and 1.5 mass% P were used as the samples. The sample grinded with SiC and diamond paste were prepared for electrochemical measurements. Anodic polarization measurements were performed in 25℃ of boric acid-borate buffer solution (pH 8.0) containing 10 mM NaCl in a non-deaerated environment. Platinum was used as the counter electrode and an Ag/AgCl electrode (3.33 M KCl) as the reference electrode. Before the polarization measurements, the immersion potential was measured for 10 min. and then cathodically treated at -1.0 V for 10 min. The sweep rate was 20 mV/min. In addition, the surface was observed by SEM and EDS after polarization at 0.2 V for 80 s to investigate the starting point of localized corrosion of the Fe-1.5 mass% P.EDS analysis was performed on all sample surfaces before electrochemical measurement. The distribution of phosphorus concentration was not observed on Fe-0.5 mass% P, whereas horizontal banded macro-segregation of phosphorus was observed on Fe-1.0 mass% P and Fe-1.5 mass% P. Furthermore, as a result of EDS analysis with a higher magnification, intergranular segregation of phosphorus was observed only on Fe-1.5 mass% P.In the anodic polarization curves of all samples, a peak was observed in the potential range of about -0.66 to -0.39 V, which could be attributed to the active dissolution of the sample. No increase of the current density was observed in the lower potential range than about 0.05 V, suggesting that the sample surface was passivated in this potential range. On the other hand, the current value increased significantly in the potential range higher than 0.05 V, due to the occurrence of localized corrosion. The current density of Fe-1.5 mass% P increased at lower potentials than for the other samples.Polarization measurement of Fe-1.5 mass% P was conducted at a constant potential to investigate the starting point of localized corrosion. A rapid increase in anode current was observed after approximately 10 seconds. SEM observations and EDS analysis were conducted on the sample surface after the test. A number of localized corrosion of about 5 µm in size was observed on the sample surface after the test. EDS analysis showed that higher concentrations of Si and Mn were detected in the corroded areas. In addition, localized corrosion with an elongated shape was also observed on the Fe-1.5 mass% P surface. Since no alloying elements (Mn and Si) derived from inclusions were detected in the corroded areas, this localized corrosion is considered to be due to intergranular segregation of P.The exposure test of all samples was conducted at Miyakojima Island, Japan for 5 years. The corrosion loss of Fe-1.5 mass% P was the smallest compared to the other samples, suggesting that the higher the P content, the lower the corrosion loss. EPMA analysis was conducted for the cross-section of the rust layer of samples after long-term exposure. P was partly concentrated in the rust layer of Fe-0.5 mass% P, but Cl penetrated into the rust layer and reached the steel substrate. On the other hand, P was fully enriched in the rust layer of Fe-1.5 mass% P and Cl was present only on the surface of the rust layer. The protective function of the rust layer due to phosphorus enrichment may have contributed to the long-term improvement of corrosion resistance.

The Effect of Micro-Sized Tin/Hard Carbon Anode Composition on Sodium-Ion Battery Performance

Sodium-ion batteries (SIBs) are a low-cost alternative to lithium-ion batteries (LIBs) for energy storage. However, their commercial application is currently limited by the unsatisfactory performance of anode materials.Hard carbon was adopted as the ‘first generation’ anode for SIBs due to the success of graphite as an anode material for LIBs. It has great chemical and thermal stability but suffers from low theoretical capacity and poor rate capability. Tin, another promising anode material, has a high theoretical capacity but is plagued by large volume changes during sodiation/desodiation, leading to faster anode degradation.To address these limitations a composite anode has been developed by direct mixing of micron-sized tin (Sn) and hard carbon (C) powders. The impact of these composite anodes on SIB performance is being investigated as a scalable approach to creating higher energy density SIBs. Half-cell batteries have been assembled from as-prepared Sn/C composite anodes with varying weight percentages of the active materials. The performance of these anodes has been compared in sodium perchlorate and sodium hexafluorophosphate electrolytes using standard electrochemical testing techniques such as galvanostatic cycling, cyclic voltammetry and electrochemical impedance spectroscopy. Our findings indicate that batteries with Sn/C anodes have a better percentage capacity retention compared to those with bare tin after forty cycles. The specific capacity observed remains over 550 mAh/g at 0.1C after 20 cycles and continues to demonstrate a good rate performance with capacity up to 430 mAh/g after 50 cycles. For high-rate cycling at 1C, the retained capacity was well over 380 mAh/g after 20 cycles. This performance and capacity retention are expected to result from the benefits of hard carbon conductive network and the formation of a more stable solid electrolyte interphase (SEI) on carbon surfaces.To complement these electrochemical characterization results, investigation of microstructural evolution of the anodes was done. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the morphology and crystal structure of the anodes. SEM images of the as-prepared pristine Sn/C composite anode revealed a uniform distribution of tin and hard carbon in the matrix of carbon black and carboxymethylcellulose (CMC) binder, with no obvious structural change. At a higher magnification, the SEM images show a higher concentration of tin particles around the hard carbon particles, compared to the rest of the matrix. XRD was used to understand the structural features of this composition. The diffraction peaks observed are associated with crystalline tin, and the absence of impurity peaks confirms the metallic nature of the Sn powder used. In addition, no significant peaks were observed for the carbon phases which is consistent with the amorphous nature of the hard carbon. The amorphous structure of the hard carbon aids in mitigation of volume expansion of tin during sodiation/desodiation. By absorbing the repeated induced mechanical stresses, the hard carbon is expected to reduce the overall anode degradation rate thus prolonging the cell performance and capacity retention.This study demonstrates the significant effect of Sn/C anode composition on SIBs and provides insightful information towards the advancement of practical SIBs. The successful development of high-performance anodes and SIBs will not only transform the landscape of energy storage systems but also alleviate the current challenges and market pressure faced by LIBs.

MT1G promotes iron autophagy and inhibits the function of gastric cancer cell lines by intervening in GPX4/SQSTM1

Gastric cancer (GC) is the fifth most common cancer and the third most common cause of cancer death globally, with high invasiveness, high recurrence rate, and poor prognosis. Multiple studies have shown that Metallothionein-1G (MT1G) is closely associated with oxidative stress, ferroptosis, and autophagy. However, the role and potential mechanisms of MT1G in GC have not been fully elucidated. This study aims to explore the biological functions and regulatory mechanisms of MT1G in GC. Perform bioinformatics analysis using the TCGA database to investigate the expression of MT1G in GC. RT-qPCR and Western blot were used to detect the expression of MT1G, ferroptosis related proteins, autophagy related proteins and ARNTL clock autophagy related proteins in Hgc27, MKN45 and AGS cell lines. Exploring the biological functions of MT1G overexpressing GC cell lines through wound healing and transwell experiments. Use specific fluorescence probes to examine mitochondrial membrane potential and Fe2+ fluorescence intensity. Using immunoprecipitation analysis (CO-IP) to elucidate the association between GC cell lines GPX4, SQSTM and ARNTL. Use flow cytometry to detect ROS expression. Observation of autophagy related morphological changes in cells using transmission electron microscopy. Compared with gastric mucosal cell lines, the expression of MT1G is decreased in three gastric cancer cell lines (Hgc27, MKN45 and AGS). Overexpression of MT1G inhibits the proliferation, migration, and invasion functions of GC cells, reduces SOD and GSH content, increases MDA content, cause the mitochondrial membrane potential to weaken and promote the transformation of JC-1 aggregates to JC-1 monomer, increases Fe2+, affects ROS, and reduces GPX4 and SLC7A11 protein expression, promoting ferroptosis. Overexpression of MT1G promotes the transformation of LC3B I to LC3B II, reduces SQSTM1 protein expression, and leads to the appearance of more autophagosomes and autolysosomes at low magnification. At high magnification, mitochondrial autophagy, endoplasmic reticulum autophagy, lipid droplet autophagy, and wrinkled mitochondrial cristae are observed, promoting autophagy. Overexpression of MT1G inhibits GPX4, thereby affecting SQSTM1 as a vector to promote ARNTL autophagy and EGLN2, promoting ARNTL clock autophagy through the GPX4/SQSTM1 axis. Our research findings elucidate that overexpression of MT1G promotes iron autophagy centered around ARNTL in GC cells via the GPX4/SQSTM1 axis, thereby inhibiting GC cell function and providing a new molecular mechanism and therapeutic target for the development of GC.

Waste lignocellulosic biomass-derived graphitic carbon encased bimetallic nickel‑palladium oxide nanofibers for efficient organic dye pollutant removal and antibacterial actions

A one-stone-for-three-bird strategy comprising lignocellulose waste management, photocatalytic toxic organic dye degradation, and anti-bacterial activity has been demonstrated using waste coconut coir derived carbon-supported NiO/PdO (NiO/PdO@C) nanocomposite. The formation of interconnected fibrous morphology with intact formation of face-centered cubic NiO and tetragonal PdO within the graphitic carbon shell in NiO/PdO@C was identified from various structural and morphological analyses. Additionally, the elemental mapping and high magnification transmission electron microscopy analyses observed the homogeneous distribution of bimetallic oxides and their complete coverage by multilayered carbon shell. After systematic structural and morphological analyses, the prepared materials were exploited as photocatalysts for the degradation of rhodamine 6G dye. The importance of NiO and PdO heterostructure formation toward overall photocatalytic activity was analyzed by performing catalytic efficiency of individual NiO@C and PdO@C nanostructures and achieving the dye removal efficiencies of 44 % and 34 %, respectively. By integrating NiO and PdO, the electron-hole charge separation was greatly increased while the electron-hole recombination was decreased, and thereby NiO/PdO@C-equipped catalysis degraded 94 % of rhodamine 6G dye within 20 min. Furthermore, similar to photocatalytic activity, the NiO/PdO@C also exhibited exceptional anti-bacterial activity against Klebsiella pneumonia (K. pneumonia), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus aureus (S. aureus) bacteria.

Restructuring the Basic Design of Several Accelerator-Based Concrete Mixes by Integrating Superplasticizers.

The increasing demand for infrastructure, the need to consolidate aging structures, and the effects of climate change imply the replacement or improvement of traditional concrete. This study investigates three accelerators and their mixtures (Ca(NO3)2·4H2O, Al2(SO4)3·18H2O, and Na2S2O3·5H2O) (series I) and their counterparts with superplasticizers (Dynamon SR41) (series II) as additives in standard concrete to improve its functionality. The standard concrete and new concrete mixes were analyzed using X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), and tests for water absorption, bulk density, and compressive strength. XRD analysis showed that all concrete mixes had similar structures composed of quartz, portlandite, larnite, calcium silicate, ettringite, albite, and muscovite in varying proportions. Their microstructures, as shown by SEM images, revealed the presence of ettringite, portlandite, and C-S-H gel at high magnification (1-5 kx). The addition of the superplasticizer remodeled the surface of the concrete mix, reducing the pore radius and increasing its compaction. These changes helped to reduce its bulk density while increasing the compressive strength. The results showed that all the concrete mixtures are similar to the standard concrete and can replace it for better functionality, but Na2S2O3·5H2O with superplasticizer concrete mixture had the higher compressive strength, supplying additional benefits.

Single Level Fast Multipole Method for frictionless rough contact problems

A perfectly smooth contact surface does not exist in nature and industrial applications. Even a body, that seems perfectly smooth to the naked eye, will show surface roughness at a higher magnification. Due to the roughness of the surface, there are areas of contact and separation, which increases the complexity of the contact calculation. However, this computational complexity increases further due to the multi-scale nature of road surface texture and large contact area in the case of tyre/road interaction. To reduce the computational complexity of this contact problem, the Single Level Fast Multipole Method (SLFMM) is developed within this paper. The contact problem is based on Boussinesq’s contact theory and for the time being, the influence of friction and lateral displacement are neglected. To validate the accuracy and reduction in computational complexity, the SLFMM was applied to rough surfaces of different complexities and compared to a reference method, the so-called Matrix Inversion Method (MIM). Results indicate that the new method computes the pressure distribution and displacement accurately, with a global error of less than 1%. The advantage of the new method compared to the MIM is the multipole expansion, which clusters adjacent contact points to a single center point. As a result, the computational complexity of the contact calculation is reduced. Overall, the Single Level FMM computes the results faster than the reference method. These results demonstrate that the Fast Multipole Method meets the requirements of accuracy and accelerated computation for rough contact problems.