Advanced Microscopy Techniques Research Articles

EXPLORING AMORPHOUS ALLOYS: ADVANCED ELECTRON MICROSCOPY AND CLUSTER ANALYSIS

In this study, we explored the atomic structure and orderliness of amorphous alloys through advanced electron microscopy and analytical techniques. Amorphous alloys, characterized by disordered atomic structures, exhibit promising applications in technology. The research addresses a crucial knowledge gap by investigating cluster distribution, particle arrangement, and orderliness within the amorphous matrix. High-resolution electron microscopy (HREM) images are analyzed using diverse algorithms and software tools. The study establishes a correlation between angles approaching 180 degrees and increased orderliness within clusters, highlighting the reliability of angle distribution analysis. Robust indicators, including Div (SP(B/V)) and Div (Mu(B/V)) metrics, assess and compare amorphous alloy samples. Kullback-Leibler (K-L) divergence indicates the significance of cluster ordering, validated by the S-K test. Radial Distribution Function (RDF) analysis uncovers local short-range order, deepening understanding despite limited orderliness discernment. These findings not only enhance our understanding of metallic glasses or amorphous alloys but also offer opportunities for tailored design and improved applications across various technological domains.

Recent progress about transmission electron microscopy characterizations on lithium-ion batteries

With the rapid development of portable electronics, new energy vehicles, and smart grids, ion batteries are becoming one of the most widely used energy storage devices, while the safety concern of ion batteries has always been an urgent problem to be solved. To develop a safety-guaranteed battery, the characterization of the internal structure is indispensable, where electron microscopy plays a crucial role. Based on this, this paper summarizes the application of transmission electron microscopy (TEM) in battery safety, further concludes and analyzes the aspects of dendrite growth and solid electrolyte interface (SEI) formation that affect the safety of ion batteries, and emphasizes the importance of electron microscopy in battery safety research and the potential of these techniques to promote the future development of this field. These advanced electron microscopy techniques and their prospects are also discussed.

Spectroscopic Analysis of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2)

Abstract: When light shines on an object, it sheds focus on the intrinsic characteristics of that material. Transmission of light or an electromagnetic (em) wave through a matter undergoes various physiochemical processes, like emission, absorption, and splitting of light into its constituent wavelengths. This interaction of em radiation with matter is widely used for the investigation of unknown and new target analytes in a sample, and the technique is known as spectroscopy. In the early 2000s, energy excitation of the virus was demonstrated in influenza. The research first demonstrated the use of Surface-enhanced Raman Scattering (SERS), whose biomedical application became a potential diagnostic tool. The LASERs also attracted attention and were incorporated with the optical and spectroscopy instruments that significantly enhanced the application, reach, and detection limit of air and waterborne elements. Surface plasmon resonance and SERS are the most applied spectroscopic techniques with high accuracy and speed. A combination of these techniques with other advanced microscopy techniques, such as atomic force microscopy, scanning electron microscopy, and tunnelling electron microscopy, may ease and boost biomedical applications. This review is focused on the application of spectroscopy and laser-based techniques in the detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2).

On wear of TiAlN coated tools with and without NbN overlayer in machining titanium alloys

Finding a wear resistant coating for cemented carbide cutting tools in the machining of difficult to cut Ti alloys is a challenge due to their high strength and chemical reactivity. Tool manufacturers recommend physical vapor deposited (PVD) TixAl1-xN (x = 0.4–0.7), and an extra NbN overlayer has shown promising potential. This study explores wear mechanisms of PVD Ti0.45Al0.55N with and without NbN overlayer and its WC-Co substrate in machining Ti alloys. To achieve an accurate understanding of tool-chip-workpiece interaction and related wear mechanisms, several approaches were employed. Tests with controlled variation of cutting speeds were complemented by process freezing experiments using the quick stop method and imitational experiments of diffusion couples. Advanced microscopy techniques were employed for accurate detection of wear products and phenomena across length scale. Findings reveal that any new design of coatings for Ti machining must combine both high mechanical integrity and resistance to diffusional dissolution and oxidation. Observed diffusional loss of Al and N from the coating results in a TiN layer which is mechanically weaker than the original coating, while the NbN overlayer reduces the Al diffusion rate, but NbN is subjected to diffusional dissolution itself. On dissolution, Nb stabilizes β-Ti and thus facilitating loss of Al, but the observed formation of intermetallic Nb3Al at the NbN–Ti interface works as a diffusion barrier. However, brittle Nb3Al can be more easily removed during machining. It was found that the coating retains longest on the edge line and protects the tool edge from failure because substrate cemented carbide wears at a faster rate than the coating with outward diffusion of C from WC grains and Co binder.

Nuclear actin dynamics and functions at a glance.

Actin is well known for its cytoskeletal functions, where it helps to control and maintain cell shape and architecture, as well as regulating cell migration and intracellular cargo transport, among others. However, actin is also prevalent in the nucleus, where genome-regulating roles have been described, including it being part of chromatin-remodeling complexes. More recently, with the help of advances in microscopy techniques and specialized imaging probes, direct visualization of nuclear actin filament dynamics has helped elucidate new roles for nuclear actin, such as in cell cycle regulation, DNA replication and repair, chromatin organization and transcriptional condensate formation. In this Cell Science at a Glance article, we summarize the known signaling events driving the dynamic assembly of actin into filaments of various structures within the nuclear compartment for essential genome functions. Additionally, we highlight the physiological role of nuclear F-actin in meiosis and early embryonic development.

Microstructure-properties relation of hydrostatically extruded absorbable zinc alloys: Effect of Mg and Cu addition on corrosion properties and biocompatibility

Pure Zn is well-known for its appropriate corrosion rate, making it suitable for use as future absorbable implants. Yet, it suffers from insufficient strength, thus, both plastic deformation and alloying are required. Hydrostatic extrusion has proven to be an efficient technique, providing high mechanical properties for zinc alloys. However, its effect on degradation rate and biocompatibility of Zn alloys remains unknown. Thus, within the present study, an attempt to evaluate those properties has been made on hydrostatically extruded pure Zn, Zn–Mg and Zn–Mg–Cu alloys. The materials were characterized by advanced microscopy techniques and uniaxial tensile tests. Corrosion properties were assessed based on electrochemical and static immersion tests. Finally, the cytotoxic effect of zinc extracts on endothelial cells were examined by standard MTT assays combined with confocal imaging.The results showed that hydrostatic extrusion results in significant refinement of α-Zn grains and the intermetallic phase Mg2Zn11 for the investigated alloys. The alloys exhibited ultimate tensile strength exceeding 300 MPa and elongation higher than 20%. Corrosion tests demonstrated that all the materials showed a similar level of degradation rate. Moreover, the uniform distribution of the intermetallic phase contributed to homogeneous corrosion of Zn alloys. Biological studies indicated that the least cytotoxic response in endothelial cells was obtained for the Zn–Mg alloy. Such an effect was caused by the limited amount of released Zn ions in the favor of Mg ions.The refinement of α-Zn grains and intermetallic phases caused by hydrostatic extrusion were key factors determining the performance of Zn-based materials.

Aluminum enhances the oxidative damage of ZnO NMs in the human neuroblastoma SH-SY5Y cell line

Bare and doped zinc oxide nanomaterials (ZnO NMs) are of great interest as multifunctional platforms for biomedical applications. In this study, we systematically investigate the physicochemical properties of Aluminum doped ZnO (AZO) and its bio-interactions with neuroblastoma (SH-SY5Y) and red blood (RBCs) cells. We provide a comprehensive chemical and structural characterization of the NMs. We also evaluated the biocompatibility of AZO NMs using traditional toxicity assays and advanced microscopy techniques. The toxicity of AZO NMs towards SH-SY5Y cells, decreases as a function of Al doping but is higher than the toxicity of ZnO NMs. Our results show that N-acetyl cysteine protects SH-SY5Y cells against reactive oxygen species toxicity induced by AZO NMs. ZnO and AZO NMs do not exert hemolysis in human RBCs at the doses that cause toxicity (IC50) in neuroblastoma cells. The Atomic force microscopy qualitative analysis of the interaction of SH-SY5Y cells with AZO NMs shows evidence that the affinity of the materials with the cells results in morphology changes and diminished interactions between neighboring cells. The holotomographic microscopy analysis demonstrates NMs' internalization in SH-SY5Y cells, changes in their chemical composition, and the role of lipid droplets in the clearance of toxicants.Graphical

A Study of Porous Activated Carbon Anodes for High-Performance Lithium-Ion Batteries

This research paper explores the intricate realm of porous activated carbon anodes for high-performance lithium-ion batteries, responding to the escalating demand for advanced energy storage systems. The study begins by delving into various synthesis methods, including physical and chemical activation, and hybrid approaches, aiming to optimize porosity and surface chemistry. Detailed investigations into structural characteristics encompass surface area, pore distribution, morphology, and surface chemistry. Advanced microscopy techniques and characterization tools provide insights into the complex interplay between structural features and electrochemical performance. Moving beyond the laboratory, the paper explores potential applications of porous activated carbon anodes. In electric vehicles, these anodes demonstrate promise in enhancing energy and power density, critical factors for the widespread adoption of electric transportation. For portable electronic devices, the lightweight nature and improved safety profile make them an attractive choice. Additionally, the study assesses the feasibility of integrating porous activated carbon anodes in grid-scale energy storage, contributing to the stability and reliability of renewable energy integration. Environmental considerations are addressed, evaluating the sustainability and recyclability of porous activated carbon anodes. The paper concludes by summarizing key findings, emphasizing the significance of porous activated carbon in advancing lithium-ion battery technology, and proposing future research directions to overcome current challenges. The extensive array of references underscores the interdisciplinary nature of the research, incorporating a diverse range of sources to provide a comprehensive overview of the field.

Noninvasive diagnostic biomarkers, genomic profiling, and advanced microscopic imaging in the early detection and characterization of Naegleria fowleri infections leading to primary amebic meningoencephalitis (PAM).

This review delves into the strategies for early detection and characterization of Naegleria fowleri infections leading to primary amoebic meningoencephalitis (PAM). The study provides an in-depth analysis of current diagnostic approaches, including cerebrospinal fluid analysis, brain tissue examination, immunostaining techniques, and culture methods, elucidating their strengths and limitations. It explores the geographical distribution of N. fowleri, with a focus on regions near the equator, and environmental factors contributing to its prevalence. The review emphasizes the crucial role of early detection in PAM management, discussing the benefits of timely identification in treatment, personalized care, and prevention strategies. Genomic profiling techniques, such as conventional PCR, nested PCR, multiplex PCR, and real-time PCR, are thoroughly examined as essential tools for accurate and prompt diagnosis. Additionally, the study explores advanced microscopic imaging techniques to characterize N. fowleri's morphology and behavior at different infection stages, enhancing our understanding of its life cycle and pathogenic mechanisms. In conclusion, this review underscores the potential of these strategies to improve our ability to detect, understand, and combat N. fowleri infections, ultimately leading to better patient outcomes and enhanced public health protection.

Investigation on different materials after pulsed high field conditioning and low-energy H- irradiation

During operation, the radio-frequency quadrupole (RFQ) of the LINAC4 at CERN is exposed to high electric fields, which can lead to vacuum breakdown. It is also subject to beam loss, which can cause surface modification, including blistering, which can result in reduced electric field holding and an increased breakdown rate. First, experiments to study the high-voltage conditioning process and electrical breakdown statistics have been conducted using pulsed high-voltage DC systems in order to identify materials with high electric field handling capability and robustness to low-energy irradiation. In this paper, we discuss the results obtained for the different materials tested. To complement these, an investigation of their metallurgical properties using advanced microscopic techniques was done to observe and characterize the different materials and to compare results before and after irradiation and breakdown testing.

Directly Identifying Multiple Cr3+ Emitting Centers for Broad Near‐Infrared Emission in an Efficient and Near‐Zero Thermal Quenching Garnet‐Type Phosphor

AbstractCr3+ doped garnet‐type (A3B2C3O12) near‐infrared (NIR) phosphors is a desirable research hotspot due to their prospective night vision, bioimaging, and plant growth utilizations. Meanwhile, the origin of multisite broad emission is yet a controversial topic. To resolve the trouble, verifying accurately the multiple Cr3+ occupancy sites is a key. Furthermore, it is an urgent need for improving the external quantum efficiency and luminescent thermostability. Herein, in Y3Sc2Al3O12 (YSAO), advanced electron microscopy technique is employed to directly confirm that the obtained broadband NIR emission originates from Cr3+ in [ScO6] octahedral and [YO8] dodecahedral sites. The optimal YSAO:5%Cr3+ sample exhibits high quantum efficiency (IQE/EQE = 74/31%) and near‐zero thermal quenching (97%@423 K and 92%@473 K). The theoretical calculations and experimental proofs reveal that YSAO possesses high structural rigidity and wide bandgap, which is responsible for the extremely thermostable luminescence. The high‐power YSAO:5%Cr3+‐converted NIR LED device shows promising multifunctional applications. This work not only provides an efficient NIR broadband phosphor with near‐zero thermal quenching, but also provides an effective determination method for the multiple emitting centers of phosphor materials.

Diversity of Complex Organic Matter in Carbonaceous Chondrites, IDPs, and UCAMMs

Complex organic matter is present in many extraterrestrial materials such as chondrite meteorites, micrometeorites, and interplanetary dust. The observed complexity of this organic matter is due to the combination of diversity of primitive organic materials that accreted onto asteroids and the subsequent effect of hydrothermal and/or metamorphic alteration that took place after accretion. These processes resulted in a variety of carbonaceous grain morphologies, elemental abundances, and organic functional group compositions. Some carbonaceous dust grains and micrometeorites have cometary origins and provide insights into the unique processing histories on those outer Solar System bodies. Isotopic analyses can help distinguish carbonaceous grains that retain their pre-accretion heritage, while advanced microscopy techniques reveal the interplay of complex organic matter with surrounding mineral.

Simple and facile synthesis of single-crystal CeO2 abrasives and its highly efficient removal mechanism on SiO2 film

CeO2 nanoparticles are one of the key abrasives for chemical mechanical polishing (CMP) in advanced integrated circuits. However, synthesizing highly chemically reactive CeO2 often involves ion doping, high-temperature calcination or reduction, which increase cleaning challenges and risk scratching wafers. We developed a simple and facile method for synthesizing single-crystal CeO2. It exhibits superior polishing performance compared to commercial CeO2, with the material removal rate (MRR) increasing to 4141.45 from 3649.99 Å/min and the surface roughness (Sa) decreasing to 0.533 from 0.647 nm. The CeO2 abrasives were characterized by X-ray Diffraction (XRD), advanced microscopy techniques (SEM, TEM), X-ray Photoelectron Spectroscopy (XPS), and Hydrogen Temperature-Programmed Reduction (H2-TPR). It revealed that the synthesized CeO2 has a particle size of approximately 60 nm and its surface was covered with a uniform amorphous layer of ∼ 1 nm. XPS and H2-TPR revealed its high Ce3+ concentration and enhanced oxygen exchange capability. The polishing mechanism was investigated by XPS and High-Resolution TEM (HR-TEM). Under pressure, the CeO2 established Ce-O-Si bonds with the SiO2 surface. Ce3+ provided electrons to the antibonding orbitals of Si-O bonds, effectively breaking stable Si-O bonds and removed SiO2 film in the form of lump SiO2 through mechanical action.

Investigation of the Changes in the Hair Cuticle Due to Chemical Degradation

Various cosmetic alterations done to the hair for aesthetic purposes have a profound damaging impact on its morphology. This study delves into the complex dynamics of hair structure by analysing the changes in the cuticle induced by chemical degradation. Advanced microscopic techniques like Microtopography and Scanning Electron Microscopy (SEM) were employed to investigate the grade of damage on treated hair as compared with virgin hair. On treatment with bleach, it could be observed that the cuticle structure in virgin hair exhibited deteriorating effects like partial degradation whereas the impact on treated hair samples strands that had previously undergone modifications exhibited much more intensifying consequences like complete deterioration exposing holes and gaps. The findings from the current exploration shed light on the nuanced relationships within the hair structure, providing valuable insights into the consequences of chemical degradation. Thus, laying a foundation for suggestive recommendations that include the impact of environment, lifestyle and genetics in the fields of trichology and cosmetology.

Visualisation of microalgal lipid bodies through electron microscopy.

In this study, transmission electron microscopy (TEM) and cryo-scanning electron microscopy (cryo-SEM) were evaluated for their ability to detect lipid bodies in microalgae. To do so, Phaeodactylum tricornutum and Nannochloropsis oculata cells were harvested in both the mid-exponential and early stationary growth phase. Two different cryo-SEM cutting methods were compared: cryo-planing and freeze-fracturing. The results showed that, despite the longer preparation time, TEM visualisation preceded by cryo-immobilisation allows a clear detection of lipid bodies and is preferable to cryo-SEM. Using freeze-fracturing, lipid bodies were rarely detected. This was only feasible if crystalline layers in the internal structure, most likely related to sterol esters or di-saturated triacylglycerols, were revealed. Furthermore, lipid bodies could not be detected using cryo-planing. Cryo-SEM is also not the preferred technique to recognise other organelles besides lipid bodies, yet it did reveal chloroplasts in both species and filament-containing organelles in cryo-planed Nannochloropsis oculata samples.

Influence of drop on the ultrastructure lipid composition of liver hepatocytes of pregnant rats

The influence of a toxic agent on the structure of the liver is inevitable. Of interest are the effects of pesticides on intrauterine formation and their teratogenic and embryotoxic properties. The influence of teratogens may manifest itself at different levels of organization of a living organism, and some aspects of cell metabolism change. Using advanced electron microscopy techniques combined with modern knowledge of membranology and toxicology, we conducted a detailed study of morphological changes in the subcellular architecture of the liver after repeated dropplet exposure. Ultrastructural studies were carried out on pregnant rats and their embryos on the 3rd, 13th, 19th days of pregnancy and embryonic development. Poisoning of animals with the pesticide dropp causes clear degenerative processes in the cellular and subcellular structures of the liver.

Innovative Microfluidic chip for Raman spectroscopy and advanced electron microscopy techniques

Innovative Microfluidic chip for Raman spectroscopy and advanced electron microscopy techniques

Unveiling the anti-corrosion properties of Zn-eggshell particle composite coatings on mild steel in seawater-simulated solution using starch as a modifier.

This study investigates the development and efficacy of Zn-eggshell particle (ESAp) coatings on mild steel, utilizing starch extract as a modifier to enhance anti-corrosion properties. Coatings with varying ESAp content (0, 2, 4, 6, and 8%) and a fixed addition of 2% starch were successfully applied via electrodeposition. The findings reveal that increasing the ESAp content results in thicker coatings, with the Zn-8% ESAp + 2% starch coating exhibiting the greatest thickness. SEM analysis confirmed the high quality of the coatings, showing no external surface defects. The Zn-8% ESAp + 2% starch-coated sample demonstrated a 46.45% increase in hardness (100.3 HB) and achieved superior corrosion protection efficiencies of 82.92% and 94.69% for Zn-8% ESAp and Zn-8% ESAp + 2% starch coatings, respectively. Electrochemical tests indicated that the coated samples shifted towards higher positive potential values, suggesting enhanced corrosion resistance. The results underscore the potential of using starch extract and waste eggshells to develop robust anti-corrosion coatings, with Zn-8% ESAp + 2% starch identified as the optimal formulation for superior protection and mechanical properties. Further research is recommended to explore the matrix-particle interactions and adhesion properties using advanced microscopic and electrochemical techniques.

Super-Resolution Stimulated Raman Scattering Microscopy with Graphical User Interface-Supported A-PoD.

Raman microscopy is a vibrational imaging technology that can detect molecular chemical bond vibrational signals. Since this signal is originated from almost every vibrational mode of molecules with different vibrational energy levels, it provides spatiotemporal distribution of various molecules in living organisms without the need for any labeling. The limitations of low signal strength in Raman microscopy have been effectively addressed by incorporating a stimulated emission process, leading to the development of stimulated Raman scattering (SRS) microscopy. Furthermore, the issue of low spatial resolution has been resolved through the application of computational techniques, specifically image deconvolution. In this article, we present a comprehensive guide to super-resolution SRS microscopy using an Adam-based pointillism deconvolution (A-PoD) algorithm, complemented by a user-friendly graphical user interface (GUI). We delve into the crucial parameters and conditions necessary for achieving super-resolved images through SRS imaging. Additionally, we provide a step-by-step walkthrough of the preprocessing steps and the use of GUI-supported A-PoD. This complete package offers a user-friendly platform for super-resolution SRS microscopy, enhancing the versatility and applicability of this advanced microscopy technique to reveal nanoscopic multimolecular nature. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Super-resolution stimulated Raman scattering microscopy with graphical user interface-supported A-PoD Support Protocol: Deuterium labeling on cells with heavy water for metabolic imaging.

A Combined Microscopy Study of the Microstructural Evolution of Ferritic Stainless Steel upon Deep Drawing: The Role of Alloy Composition

Ferritic stainless steel (FSS) is widely used to manufacture deep-drawn products for corrosion resistance applications, being the alloy drawability strongly affected by its microstructural anisotropy. This study combines a variety of microscopy techniques enabling in-depth analyses of the microstructural evolution of two different FSSs correlated to their deep drawing performance. One of the steels has a good correspondence with the standard EN-1.4016 (AISI 430). The other is a modified version of the previous one with higher contents of the ferrite-stabilising elements Si and Cr, and lower contents of the austenite-stabilising elements C, N, and Mn. Electron Backscatter Diffraction results confirm that the microstructural properties and drawability of FSS in the deep drawing process are improved in the modified steel version. Scanning transmission electron microscopy under low-angle annular dark field conditions evidences that the deformation mechanism of FSS during deep drawing follows a microstructural distortion model based on the grain size gradient and shows a variation of the deformation texture depending on the alloy composition. This work demonstrates the potential of advanced microscopy techniques for optimising the processing and design of ferritic stainless steels, with slight variations in the alloy composition, for deep drawing applications.