Search

Recent advancements in nanostructured materials have found widespread application across many domains, particularly in the biomedical field. Before using nanostructured materials in clinical applications, many important challenges, especially those related to their uses in biomedicine, must be resolved. Biological activity, compatibility, toxicity, and nano-bio interfacial characteristics are some of the major problems in biomedicine. We may therefore investigate the nanostructured materials for biomedical applications with the aid of modern characterization techniques. This overview article illustrates the present state of nanostructured materials in the biomedical field with uses and the importance of characterization methods through the use of cutting-edge characterization techniques. In this article, the techniques for analysing the topology of nanostructures, including Field Emission Scanning Electron Microscopy (FESEM), Dynamic Light Scattering (DLS), Scanning Probe Microscopy (SPM), Near-field Scanning Optical Microscopy (NSOM), and Confocal microscopy, are described. In addition, the internal structural investigation techniques X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), and Magnetic Resonance Force Microscopy (MRFM) are discussed. In addition, composition analysis techniques such as X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray spectroscopy (EDS), Auger Electron Spectroscopy (AES), and Secondary Ion Mass Spectroscopy (SIMS) have been discussed. The essence of the nanomaterials as they relate to physics, chemistry, and biology is thoroughly explained in this overview along with characterization techniques through case studies. Additionally, the constraints and difficulties with specimen and analysis that are related to comprehending nanostructured materials have been identified and addressed in this study.

Due to their excellent physical properties and high strength and stiffness relative to density, aerospace industry research is producing high-performance structural materials, such as composites, which are used in many critical structural parts like airframes, wings, rotor blades, propellers, and other components. However, during flight, these materials may be damaged by impact, thermal stress, moisture, and ultraviolet radiation. One of the most prevalent issues with composite materials is their challenging nature in terms of flaw detection during both manufacturing and use. When they are employed in the crucial areas that were previously indicated, this becomes a very serious issue. When evaluating the structural integrity of composites and looking for any damage, microscopes are a very useful instrument. Effective methods for identifying and analyzing damage include microscopic procedures like optical microscopy, stereomicroscopy, scanning electron microscopy (SEM), scanning ion microscopy (SIM), and atomic force microscopy (AFM). A variety of methods may be employed with microscopes to examine and identify deterioration in composite materials. It is often possible to examine overt deterioration on the surface of composite materials under the microscope utilizing a number of different approaches and procedures. Determining the kind, extent, distribution, and impact of the damage requires these inspections. Often employed techniques consist of: SEM is a method for high-resolution imaging of surface damage. It entails shining an electron beam onto the sample's surface and capturing pictures. SEM is a useful tool for identifying erosion, delamination, and microcracks. It is also possible to measure things like the damage's breadth and depth. Optical microscopes have a large field of view and look at damaged regions. This makes it possible to find tiny fractures or cracks that are invisible to the unaided eye. Furthermore, details on the degree of harm, the roughness of the surface, and the breadth and depth of the fractures may be acquired. To see damaged objects, optical microscopy is utilized. Cracks and damage locations are visible with optical microscopy. Optical microscopes can identify different kinds of damage by looking at the surface of the material. Damage like delamination, fiber breakage, cracks, and deformations are a few examples of these. This study examines the efficacy of microscopic methods and non-destructive testing in assessing the different kinds of damage that can occur at the interfaces between holes in composite materials. Composite test materials were chosen from glass fiber reinforced phenolic matrix composites that were produced in compliance with aerospace standards. The measurements led to the conclusion that using microscopic techniques has benefits like speed and field suitability. However, the continuous development and improvement of new methods in this field will contribute to a better understanding of layered composite materials and the development of safer and more durable structures.

Structural Health Monitoring (SHM) is a process that involves the observation and analysis of a system over time using periodically sampled response measurements to monitor changes to the material and geometric properties of engineering structures such as bridges, buildings, and aerospace composite structures. The goal of SHM is to detect changes in the structural behavior or condition that may indicate damage or degradation before a catastrophic failure occurs. SHM involves the implementation of damage detection strategies for structures of high importance. It is commonly used in civil engineering, aerospace engineering, and mechanical engineering applications to ensure the safety and reliability of structures. It improves the safety of aerospace composite structures by detecting damage at an early stage, preventing damage from occurring, improving reliability, and extending the life of the structure. SHM applications enable aircraft to spend less time on the ground and carry more passengers and cargo, thereby reducing operational costs. It can be utilized in various fields such as monitoring the health condition of aircraft tail and wing areas in the aviation industry, preventing damage and deterioration of car parts and components under operating conditions in the automotive sector, monitoring the health condition of bridges and tunnels in the transportation sector, and monitoring the health condition of wind turbines and other structures in the energy sector. Aerospace composite structures can suffer from several complex nonlinear damage modes, including impact damage, delamination, matrix cracking, fiber breakage, and voids. This study provides general and useful information on how structural health applications of aviation composites can be supported by microscopic techniques. In order to better understand the subject, an example aircraft composite structural component containing impact damage, which was mentioned above, was examined using microscopic techniques. In this investigation conducted using Stereo and Scanning Electron Microscopes (SEM), the identification of potential damage sources and the assessment of damage severity are explained in detail.

Fire protection systems are used to prevent fires and the spread of combustion products from one room to another. The systems include screens, curtains, drapes, etc. The article is devoted to the study of fire resistance and thermoanalytical properties of non-combustible materials used in passive fire protection system. Samples based on silica mat (No. 1); ultrafine basalt fiber (No. 2); quartz aerogel (No. 3), and ceramic mat (No. 4) were studied. Sample No. 1 was covered with carbon impregnated fabric. Samples No. 2, 3, 4 were covered with silica fabric with vermiculite coating. During standard fire test, all samples showed fire resistance limit (FRL) E 60. In terms of thermal insulation capacity, sample No. 2 turned out to be the best with the FRL I 30. Thermoanalytical study showed that the maximum weight loss (12.7 %) was recorded in sample No. 1. The minimum weight loss (0.823 %) was recorded in sample No. 2 in a nitrogen atmosphere. Thus, the material filled with ultrafine basalt fiber showed the best results, and it is recommended to be used as part of fire barriers to create fire-resistant casings, covers and fire-resistant curtains.

Sea buckthorn is a promising ingredient for the food industry because it is a good source of vitamins, polyphenols, phytosterols, etc. In this research, it is the first time that aqueous extracts of lyophilized sea buckthorn (LSB) 0%, 0.5%, 1%, 2%, and 3% w/w were used to enrich set-type yogurts. Therefore, fermentation kinetics, hardness, color, titratable acidity, syneresis, water holding capacity, total phenolic content microstructure, and sensory analysis were investigated. Extracts of lyophilized sea buckthorn shorten the yogurt fermentation time, change the microstructure, reduce syneresis, and increase water-holding capacity compared to plain yogurt. Also, the titratable acidity for all yogurts remained the same but the total phenolic content of yogurts increased as the concentration of extracts from lyophilized sea buckthorn increased. The color parameters of the fortified set-type yogurts were affected by the color of the sea buckthorn extract with increasing a* and b* values according to extract concentrations. Finally, yogurts fortified with 0.5% and 1.0% w/w extracts of LSB have good quality characteristics, increased total phenolic content, and higher scores of being liked compared to the rest of the enriched samples. This study could increase the knowledge of the uses of aqueous extracts of lyophilized sea buckthorn in dairy products.

Automotive brake friction composites based on several combinations of barium sulphate and cement by-pass dust (CBPD) were manufactured and tribo behaviour is examined as per European regulations on a Krauss machine. The friction coefficient increased upon increasing the amount of CBPD from 0 to 30 wt% and then decreased above 30 wt% CBPD and below 20 wt% barium sulphate contents. Conversely, friction fluctuations and wear increased with decreasing barium sulphate and increasing CBPD contents. In particular, 20 wt% barium sulphate and 30 wt% CBPD filled composites showed the highest friction performance of 0.361, moderate friction stability of 0.76, highest recovery performance of 123.27%, and lowest friction variability of 0.60, whereas the composite with 50 wt% CBPD showed the highest fade resistance of 15.36%. The friction and wear analysis revealed that the fade and recovery response decide the overall frictional performance, whereas material integrity and fade response were the significant determinants of wear performance. The composites' worn surfaces were examined to investigate the associated wear mechanism at the braking interface.

Immersion microscope objectives stand out for their large numerical aperture, which improves the optical resolution of imaging systems such as those used in microscopic interferometry. These objectives increase the gradient forces of a beam focused through them, forming an Optical Trap (OT). However, many studies on microscopic interferometry neglect the contributions of different optical materials in the system that are also exposed to laser radiation, perhaps simply assuming transparency. In this work, a Mach–Zehnder interferometer and an OT, which share several components (including the same oil immersion objective), were coupled. Here, the response of the interferometer to a progressive increase in the OT laser power, while the interferometer laser power remains constant, is reported. Changes in laser power affect the oil temperature, altering its refractive index and volume, which in turn causes a phase shifting on the transmitted wavefront. Optical phase analysis is applied in the three-dimensional measurement of the damage produced by the OT on a paint film. This study suggests that the refractive index variations in the immersion oil affect interferograms because they will then exhibit an additive phase term that must be considered in that final measurement. Additionally, the OT geometry changes with the power increase.

The Fourier transform infrared microspectroscopy (FTIRm) system of the Australian Synchrotron has a unique optical configuration with a peculiar beam profile consisting of two parallel lines. The beam is tightly focused using a 36× Schwarzschild objective to a point on the sample and the sample is scanned pixel by pixel to record an image of a single plane using a single pixel mercury cadmium telluride detector. A computational stitching procedure is used to obtain a 2D image of the sample. However, if the imaging condition is not satisfied, then the recorded object’s information is distorted. Unlike commonly observed blurring, the case with a Schwarzschild objective is unique, with a donut like intensity distribution with three distinct lobes. Consequently, commonly used deblurring methods are not efficient for image reconstruction. In this study, we have applied a recently developed computational reconstruction method called the Lucy–Richardson–Rosen algorithm (LRRA) in the online FTIRm system for the first time. The method involves two steps: training step and imaging step. In the training step, the point spread function (PSF) library is recorded by temporal summation of intensity patterns obtained by scanning the pinhole in the x-y directions across the path of the beam using the single pixel detector along the z direction. In the imaging step, the process is repeated for a complicated object along only a single plane. This new technique is named coded aperture scanning holography. Different types of samples, such as two pinholes; a number 3 USAF object; a cross shaped object on a barium fluoride substrate; and a silk sample are used for the demonstration of both image recovery and 3D imaging applications.

Spherical, multicellular aggregates of tumor cells, or three-dimensional (3D) tumor models, can be grown from established cell lines or dissociated cells from tissues in a serum-free medium containing appropriate growth factors. Air–liquid interfaces (ALIs) represent a 3D approach that mimics and supports the differentiation of respiratory tract and skin 3D models in vitro. Many 3D tumor cell models are cultured in conjunction with supporting cell types, such as fibroblasts, endothelial cells, or immune cells. To further mimic the in vivo situation, several extracellular matrix models are utilized to support tumor cell growth. Scaffolds used for 3D tumor cell culture growth include both natural and synthetic hydrogels. Three-dimensional cell culture experiments in vitro provide more accurate data on cell-to-cell interactions, tumor characteristics, drug discovery, metabolic profiling, stem cell research, and diseases. Moreover, 3D models are important for obtaining reliable precision data on therapeutic candidates in human clinical trials before predicting drug cytotoxicity. This review focuses on the recent literature on three different tissue types of 3D tumor models, i.e., tumors from a colorectal site, prostate, and skin. We will discuss the establishment of 3D tumor cell cultures in vitro and the requirement for additional growth support.

The applications of insulation materials in buildings and vehicles are more important than ever. Therefore, the application of thermal insulation materials having high-performance heat-blocking properties such as nano-structured insulations like aerogels and graphite polystyrene is essential. In this paper a comprehensive thermal characterization will be presented, executed on two types of fibrous aerogels (slentex, pyrogel) as well as on graphite-expanded polystyrene, to compare their thermal insulation capability. Moreover, their possible sandwich-structured application as hybrid insulation systems was tested, too. The surface analysis of the samples is going to be presented through microscopic and wetting experiments. Thermal conductivity as well as specific heat capacity measurement results of both individual and sandwich structures will be shown. Slentex aerogel has the lowest thermal conductivity and performed best of all. The results of the hybrid structures are promising. The moisture uptake of the pyrogel aerogel is the highest. Based on the measured values theoretical models will be applied for validation, moreover, a face-to-face analysis will also be presented. Furthermore, calculations regarding thermal properties will also be highlighted. Results of both infrared absorption tests and differentiated scanning calorimetry would help the decision makers and it proves the high infrared absorption of graphite polystyrene.

Optical imaging of objects at the nanometric scale is limited by light diffraction, and for this reason several sub-diffractive optical microscopy techniques have been developed in the last decades. In this article we present an optical laser microscope specifically designed for detection of nano-materials exploiting the Mie scattering between the evanescent wave generated by a laser beam travelling in a transparent substrate through total internal reflection and the nano-objects deposited on the substrate itself. The setup, including the laser source, can be fully integrated inside an optical microscope requiring only a geometric alignment with the substrate thus reducing the complexity and the cost. We also report two possible applications: quantitative detection of Au nanoparticles in the 20-100 nm size range and semi-quantitative detection of virions immobilized on the substrate through bioreceptor / antigen binding, including, but not limited to, SARS-CoV-2. A minimum virus amount of ≈105 in the reaction volume is observed. The results presented here open the route towards unprecedent applications in molecular biology or molecular diagnostics.

The purpose of the article is to determine the sequence of mineral formation of copper-nickel ores of Kun-Manie deposit, which is located in Zeya district of Amur region. Three ore chutes take part in the structure of the deposit. Ore-bearing formations are sheet and sheetlike bodies of ultra-basic composition of the Kun-Manien complex, lying among rocks of crystal foundation of the Early Archean. Among the rocks, hornblende differences of gabbro-pyroxenites and pyroxenites predominate. In addition to nickel, the ores contain a wide range of associated components. The ores oxidation zone within the deposit and the entire ore field is not developed. The relevance of the work is due to the fact that detailed studies of ore minerals have not previously been carried out. The study presented in the work was conducted by polarizing ore microscope on polished ore samples characterizing different zones of the ore body. The result of the study was the establishment of mineral paragenesis and the sequence of mineral formation. It has been determined that the main ore minerals are pyrrhotine, pentlandite, also found - pyrite, chalcopyrite, less often - ilmenite, magnetite, sphalerite, platinum group elements. Ore mineralization formed in two stages. The magmatic stage is an early and main mineral formation phases including pyrite-magnetite, polymetallic and pentlandite associations. The hydrothermal stage is a late phase involving a pyrite association.

Polychromy in Ancient Greek Sculpture was the subject of the exhibition Chroma: Ancient Greek Sculpture in Color, held at The Metropolitan Museum of Art (The Met), New York, in 2022–2023. On this occasion, a multidisciplinary project involving The Met’s Departments of Greek and Roman Art, Objects Conservation, Imaging, Scientific Research, and colleagues from the Liebieghaus Polychromy Research Project in Frankfurt, Germany, was carried out to study an Attic funerary monument. The color decoration of the sphinx was reconstructed by combining non-invasive and minimally invasive techniques that provided information about surviving and lost pigments, original design, and painting technique. Results of multiband imaging, digital microscopy, and X-ray fluorescence spectroscopy guided the removal of minute samples from selected areas for examination by Raman spectroscopy and scanning electron microscopy, coupled with energy-dispersive X-ray spectroscopy, to shed light on the pigments and paint stratigraphy. The color palette included two varieties of blue, Egyptian blue and azurite, a carbon-based black pigment, two reds, cinnabar and red ocher, and yellow ocher, all painted directly over the marble without a preparation layer. The scientific findings informed the physical reconstruction of the sphinx made by archaeologists from the Liebieghaus Polychromy Research Project, featured in the exhibition.

Hemocompatible nanoparticles with reactive oxygen species (ROS) scavenging properties for titanium implant surface coatings may eliminate implant failure related to inflammation and bacterial invasion. Cerium (Ce) is a rare earth element, that belongs to the lanthanide group. It exists in two oxidation states, Ce+3 and Ce+4, which contribute to antioxidant, catalytic, antibacterial, and ROS-scavenging properties. The purpose of the present study was to synthesize ceria nanoparticles and to evaluate their hemocompatibility and ROS scavenging properties. The synthesis of Ce-NPs was performed via the sol-gel method, and five different ratios of cerium precursors to gelatin were evaluated. Their characterization was achieved through FTIR, XRD, SEM, and TEM. Hemocompatibility and ROS analysis were evaluated at different concentrations with human erythrocytes. The morphology and size distribution were certified by TEM and the cubic CeO2 fluorite structure was identified by selected area electron diffraction and high-resolution TEM. The particle size of the lowest Ce concentration presented a mean diameter of 10 nm. At concentrations of 2 NPs unique candidates as nanofillers or nanocoatings with antibacterial properties.

Scientists are concerned about the health risks associated with consuming a diet high in saturated fats. In this regard, oleogels have been used as a shortening substitute by researchers. This present study evaluated the role of stearyl alcohol (SA)-, and Span-60 (SP)-tailored sunflower wax/sunflower oil oleogels upon butter replacement in whole wheat batter and cake. The evaluation of the cake batter under PLM microscopy revealed that a complete replacement of butter with SA-containing oleogels, i.e., Sa-C, showed homogenously distributed smaller gas cells. A uniform distribution of gas cells assists in stabilization and contributes to the porosity of the cake. The DSC and FTIR studies confirmed the prominent melting of amylose-lipid complexes in batter Sa-C. The baked cake Sa-C showed the existence of large pores in the cake matrix, which may have assisted in softening the cake. Further, low starch–lipid interactions were also observed in the FTIR spectra of Sa-C cake crumbs. The SR studies of cake crumbs revealed a higher stress-relaxing ability in Sa-C from the control. Although there were no observed variations in the cake hardness values, Sa-C showed a reduction in the chewiness from the control. This current study suggests the possibility of using emulsifier-tailored oleogels as a potential substitute for butter in the baking formulation.

Titanium-based alloys are constantly improved to obtain properties suitable for their use. Improving titanium alloys is very important for performing alloys without side effects. In this paper effects of structure, microhardness, and indentation test of eight titanium alloys were investigated after aging. The heat treatment consisted of a high-temperature quenching accomplished in three steps (650 °C for 25 min, 850 °C for 20 min, and 950 °C for 20 min). The cooling process was accomplished using N2 gas, introduced in the chamber at a 9-bar pressure for 37 min. Then, followed by heating to a constant temperature tempering (550 °C) at 1.5 bar pressure and kept for 2 h and 10 min at 2 bar pressure. Optical microscopy images were obtained of Ti-Mo-Zr-Ta alloys with grain-specific aspects of titanium alloys; acicular and coarse structures are specific to β alloys. Microhardness results showed significantly influenced by the heat treatment, increased by approximately 5% for Ti15Mo7Zr15Ta1Si and Ti20Mo7Zr15Ta0.5Si, while for Ti15Mo7Zr15Ta0.5Si and Ti20Mo7Zr15Ta an approximately 9% decrease has been noted. The modulus of elasticity results obtained by the indentation method for the experimental alloys were between 36.25–66.24 GPa. The heat treatments applied to the alloys had a pronounced effect, improving both the structure of the alloys and the results of the indentation test.

Bromelia hemisphaerica Lam., a wild plant native to Mexico, has medicinal attributes and is mainly used for its hemisphericin content in foods. However, the residues of its leaves and fruits are underutilized, representing an area of opportunity for foods or materials. Lignocellulosic material from leaves and fruit bagasse was isolated using an organosolv treatment to separate their components (cellulose, hemicellulose and lignin) and to determine the influence after processing on the physicochemical, thermal and microstructural characteristics. The extracted fiber presented a cellulose content of 44% in the leaf and 33.5% in the fruit. The release of lignin after the organosolv process represented a greater amount of amorphous material in the leaf than in the fruit. By FTIR and X-ray diffraction (DRx), the change in the crystallinity of the cellulose was determined (from 18% higher in the leaf than the fruit before to 14% higher in the fruit after the organosolv process), with values similar to type I cellulose. The thermal properties showed a high order in the structure of the cellulose. Microscopy and digital analysis techniques showed the microstructural changes and the effectiveness of delignification during the process. It is concluded that the leaf fiber of B. hemisphaerica presents characteristics that make it useful as a potential ingredient for food product development and other uses.

(1) Background: Chorda tympani (CT) manipulation during stapes surgery affects its functions. We hypothesized that this alters tongue morphology and sensory functions. (2) Methods: Patients undergoing stapes surgery were tested 1 day preoperatively, 1 and 6 months postoperatively. Narrow band imaging contact endoscopy (NBI) was used to determine the number of fungiform papillae (Npapillae) and the total score of blood vessel morphology (NBItotal). The taste was tested with taste strips. General sensation was tested with a static two-point discrimination. Tests were performed on ipsilateral and contralateral side of the tongue. (3) Results: 52 otosclerosis patients were included in the study. There was a statistically significant decrease of NBItotal (p = 0.005), Npapillae (p = 0.009), sensation of sweet (p = 0.003), salty (p = 0.035), sour (p = 0.036), and bitter taste (p = 0.013) within the test side during the follow-up. A statistically significant impact on presence of dysgeusia for sweet was found 1 month postoperatively (p < 0.005). Postoperative decrease in two-point discrimination score did not reach a statistical significance (p = 0.056). (4) Conclusions: CT manipulation affects fungiform papillae density, vascular patterns and taste sensation. The general sensation of the tongue is not influenced by CT manipulation.

A progressive honey bee population decline has been reported worldwide during the last decades, and it could be attributed to several causes, in particular to the presence of pathogens and parasites that can act individually or in synergy. The health status of nine apiaries located in different areas of the Veneto region (northeast of Italy) was assessed for two consecutive years (2020 and 2021) in spring, during the resumption of honey bee activity, for determining the presence of known (Nosema spp., Varroa mite and viruses) and less known or emerging pathogens (Lotmaria passim and Crithidia mellificae) in honey bees. After honey bees sampling from each of the nine apiaries, Nosema apis, Nosema ceranae, L. passim, C. mellificae, ABPV, CBPV, IAPV, KBV, BQCV, SBV, DWV-A, DWV-B and V. destructor were investigated either by microscopic observation or PCR protocols. The viruses BQCV, SBV, CBPV followed by N. ceranae and L. passim were the most prevalent pathogens, and many of the investigated hives, despite asymptomatic, had different degrees of co-infection. This study aimed to highlight, during the resumption of honey bee activity in spring, the prevalence and spreading in the regional territory of different honey bee pathogens, which could alone or synergistically alter the homeostasis of bees colonies. The information gathered would increase our knowledge about the presence of these microorganisms and parasites in the territory and could contribute to improve beekeepers practice.

Microplastics are found in various environments with the increasing use of plastics worldwide. Several methods have been developed for the sampling, extraction, purification, identification, and quantification of microplastics in complex environmental matrices. This study intends to summarize recent research trends on the subject. Large microplastic particles can be sorted manually and identified through chemical analysis; however, sample preparation for small microplastic analysis is usually more difficult. Microplastics are identified by evaluating the physical and chemical properties of plastic particles separated through extraction and washing steps from a mixture of inorganic and organic particles. This identification has a high risk of producing false-positive and false-negative results in the analysis of small microplastics. Currently, a combination of physical (e.g., microscopy), chemical (e.g., spectroscopy), and thermal analyses is widely used. We aim to summarize the best strategies for microplastic analysis by comparing the strengths and limitations of each identification method.

Light isolation and temperature regulation are often required for microscopic imaging. Commercial enclosures are available to satisfy these requirements, but they are often not flexible to the variety of custom systems found in research laboratories. We present the design for an affordable enclosure which utilizes aluminum t-slot profiles to support opaque expanded PVC panels. Temperature is regulated by exchanging the enclosure air with an external heater. In addition, we demonstrate baffles integrated into the enclosure improve temperature uniformity. Example designs for both upright and inverted microscopes are given, providing a starting point for creating a system-specific custom enclosure.

The Amazon rainforest is considered a megadiverse biome, where several species of its rich flora are still unknown. The anatomy of their leaves usually identifies species. In this paper, we present a complete characterization of the leaf surface of Amazon Carapa guianensis Aubl. (Andiroba), using microscopy and fractal theory to be considered a possible tool for investigating different leaves spatial patterns, especially in species with similar leaf architecture. The SEM results revealed the cellular structures and other non-cellular structures that make up the leaf architecture, both for the abaxial and adaxial sides. The cells responsible for the plant photosynthesis process were observed in the internal structure of the leaf. The wettability analysis showed that the abaxial side is more hydrophobic, while the adaxial side is more hydrophilic. AFM images exposed the relevant details of the microstructure of the leaf abaxial side, such as stomata, pores, furrows, contour, particles, and rough profiles generated by topographic irregularities. The statistical parameters revealed that the scale size influences the topographic roughness, surface asymmetry, and shape of the height distribution, also observed by advanced parameters obtained according to the standard of the international organization for standardization (ISO). The fractal and advanced fractal parameters confirmed changes in spatial patterns as a function of scale size. The largest area exhibited greater spatial complexity, low dominant spatial frequencies, more excellent surface percolation, intermediate topographic homogeneity, and high uniformity of spatial patterns.

Drying kinetics and shrinkage of valerian plant root (Valeriana officinalis) was investigated during the convective hot air dryer with forced convection mode. Whole root without cutting, root cut into quarters, and root cut into 2 mm thin slices were used in drying experiments. Initial moisture content of roots was 51.2±0.3% and roots were considered to be dry when they lost 68% of the fresh weight and reached the moisture content of 10%. Drying air temperature was set to be 40 and 50°C, air velocity at 1 m/s. The relative humidity of drying air was not controlled and it depended on surroundings. The experimental results were fitted to the five thin layer drying models and according to the non-linear regression analysis Page model was most suitable to describe the drying kinetics. The characteristic drying curves were created for each experimental set and they showed that the samples' preparation strongly influenced the drying process and drying time. Experiments to determine shrinkage of different cell structures of valerian root were carried out for raw material, as well as for dried samples, by using optical and electron microscopy observations and measurements. It was observed that shrinkage processes are significantly dependent of the type of cell tissue and drying air temperature.

Despite extensive research, the exact pathomechanisms associated with epileptic seizure formation and propagation have not been elucidated completely. Two-photon imaging (2PI) is a fluorescence-based microscopy technique that, over the years, has been used to evaluate pathomechanisms associated with epileptic seizures and epilepsy. Here, we review previous applications of 2PI in epilepsy. A systematic search was performed in multiple literature databases. We identified 38 publications that applied 2PI in epilepsy research. These studies described models of epileptic seizure propagation; anatomical changes and functional alterations of microglia, astrocytes, and neurites; and neurometabolic effects that accompany seizures. Moreover, various neurovascular alterations that accompany seizure onset and ictal events, such as blood vessel responses, have been visualized using 2PI. Lastly, imaging and quantitative analysis of oxidative stress and the aggregation of lipofuscin in the neurovasculature have been accomplished with 2PI. Cumulatively, these papers and their reported findings demonstrate that 2PI is an especially well-suited imaging technique in the domain of epilepsy research, and these studies have significantly improved our understanding of the disorder. The application of 2PI provides ample possibilities for future research, most interestingly on human brains, while also stretching beyond the field of epilepsy.

The surface and thickness distribution measurement for transparent film is of interest for electronics and packaging materials. Structured illumination microscopy (SIM) is a prospective technique for measuring film due to its high accuracy and efficiency. However, when the distance between adjacent layers becomes close, the peaks of the modulation depth response (MDR) start to overlap and interfere with the peak extraction, which restricts SIM development in the field of film measurement. In this paper, an iterative peak separation algorithm is creatively applied in the SIM-based technique, providing a precise peak identification even as the MDR peaks overlap and bend into one. Compared with the traditional method, the proposed method has a lower detection threshold for thickness. The experiments and theoretical analysis are elaborated to demonstrate the feasibility of the mentioned method.

Intracellular mechanical work facilitates multiple cell functions, such as material transport, cell motility, etc., and is indicative of the cell’s physiological condition. Still, the characterization of intracellular mechanical work and resultant dynamics remain hard to determine in intact label-free cells. For that, we imaged live T cells via bright-field microscopy and studied fluctuations in the homogeneity of their intracellular medium. Specifically, we characterized medium homogeneity and dynamics by using the information entropy of its related intensity gray levels (termed Gray Level Information Entropy (GLIE)) and spectral analysis of GLIE fluctuations, respectively. First, we provide simple examples of particle motion, to demonstrate the utility of our approach. Using this approach, we could further study and distinguish mitochondrial dysfunction and ATP depletion state in live Jurkat cells. The relation of our results to intracellular dynamics was confirmed by comparison to image correlation spectroscopy (ICS) results in the same cells. Importantly, GLIE fluctuations combined with spectral analysis enabled differentiation of malignant Jurkat cells from benign lymphocytes with 86% accuracy for single cells and 95% for populations of 10 cells each. Our approach can serve for label-free live-cell study and diagnostics of important pathophysiological conditions, such as mitochondrial dysfunction and malignancy.

We investigated the impact of ultrasound at 20 kHz on olive leaves to understand how acoustic cavitation could increase polyphenol extraction. Application of ultrasound to whole leaf from 5 to 60 min enabled us to increase extraction from 6.96 to 48.75 µg eq. oleuropein/mL of extract. These results were correlated with Environmental Scanning Electron Microscopy, allowing for leaf surface observation and optical microscopy of treated leaf cross sections to understand histochemical modifications. Our observations suggest that the effectiveness of ultrasound applied to extraction is highly dependent on plant structure and on how this material will react when subjected to acoustic cavitation. Ultrasound seems to impact the leaves by two mechanisms: cuticle erosion, and fragmentation of olive leaf surface protrusions (hairs), which are both polyphenol-rich structures.

Aim of the present work is to investigate mechanical and metallurgical characteristics of continuous wave CO2 laser welded dissimilar couple of AISI 304 stainless steel and commercially pure copper sheets in autogenous mode. Metallurgical analysis of the fusion zone has been done to understand the mixing and solidification behavior. Macroscopic examination has been carried out to observe the macro-segregation pattern of Cu, Fe and Cr rich phases in different zones, and the thickness of HAZ was found to be around 10 µm. The micro-channels formed from the steel side to weld pool describe that the copper solidifies first and provides the nucleation surface for the residual melt to grow. These tubular micro-channels formed may be due to carbide precipitation. The EDS analysis conforms the well mixing of SS and Cu inside the weld pool. The mechanical properties in terms of tensile stress found up to 201 MPa and the fracture are obtained outside the weld zone. Microhardness measurements over the fusion zone have been done to understand the keyhole growth and quenching, solidification sequence and stress distribution over the full area.