Microscopy and Microanalysis最新文献

The benefits of an intermittent compression therapy are known; however, in some circumstances, it results in soft-tissue injuries. This study aims to create a model for testing the safety, efficacy, and molecular mechanisms of a compression therapy, without creating an injury. Existing ischemia/reperfusion protocols were modified to apply repeated compression without forming a pressure ulcer. The skin of immobilized C57BL/6 male mice was pinched between two magnets (3 h, 2-3 days of recovery between treatments). Hair growth was stunted but started to regrow within 18 days. The application of pressure caused an increase in epidermal thickness (****p = 0.002), CD31+ total number (**p = 0.0021), and increased radial diffusion distance (*p = 0.0285). Pressure caused a reduction in adipocyte volume weight mean volume (****p < 0.0001) and CD34 volume fraction (*p = 0.0460). Stem cell populations (cytokeratin 15; p = 0.4992, CD34; p = 0.6873 and integrin α-6; p = 0.7752) were unaffected. Importantly, pressure did not increase markers of DNA damage (p53; p = 0.7524 and caspase 3; p = 0.0839), indicating that this compression model had limited negative effects on the tissue. The altered protocol successfully created a model to permit the analysis of uninjured skin after pressure is applied.

To understand the potential hazards of palladium particles dispersed in the environment, comprehensive toxicological studies are required. Quercetin (Que) is a natural flavonoid compound with antioxidant properties. This study was conducted to investigate the potential protective effects of Que (30 mg/kg bw) usage against oxidative stress, apoptosis, inflammation, and endoplasmic reticulum (ER) stress damage in palladium chloride (PdCl2) (8 mg/kg bw)-induced hepatorenal toxicity in rats. As a result of 28 days of PdCl2 application, antioxidant capacity (SOD, CAT, GPx, and GST) in hepatorenal tissues decreased, and the MDA level, which is a marker of lipid peroxidation, increased. In addition, changes were determined in markers such as ALT, AST, LDH, urea, and creatinine in serum. Similarly, PON-1 and AChE activities decreased and NO, 8-OHdG, IL-1β, and IL-6 levels and TNF-α expression increased. Due to PdCl2 exposure, cytoprotective transcription factor Nrf2 expression decreased and caspase-3 expression increased. Along with the increase in ER stress (HSP70, HSP90, GRP78, and CHOP) induced by PdCl2, a decrease in aquaporin 1 and nephrin expressions was observed in renal tissues due to histopathological changes in hepatorenal tissues. Que treatment together with PdCl2 reduced PdCl2-induced hepatorenal toxicity and provided improvement in the investigated parameters.

The folding and structure of biomacromolecules depend on the three-dimensional distributions of their constituents, and this ultimately controls their functionalities and interactions with other biomacromolecules. Atom probe tomography (APT) with its unparalleled compositional sensitivity at nanoscale spatial resolution, could provide complementary information to cryo-electron microscopy, yet routine APT analysis of biomacromolecules in their native state remains challenging. Here, we used a solution containing ferritin as a model biomacromolecule, and following plunge freezing in liquid nitrogen (LN2), performed cryogenic specimen preparation via lift-out, and APT analysis. We measure elements from the ferritin core and shell, yet the proteins themselves appear to have been destroyed. We hence demonstrate the feasibility of preparing and analyzing bulk hydrated biological samples using APT; however, plunge freezing in LN2 is too slow to vitrify the solution into its vitreous state. This caused irrecoverable damage to the protein shell surrounding the ferritin particles due to the ice crystal formation. We report on preliminary data from high-pressure frozen deionized water, demonstrating a proof-of-principle experiments that intact biomacromolecules could be analyzed through a similar workflow in the future. We report on many trials (and errors) on the use of different materials for substrates and different substrate geometries, and provide a perspective on the challenges we faced to facilitate future studies across the community.

While the idea of imaging biological molecules by electron microscopy in the liquid phase might seem to be quite attractive, fundamental problems inherent in this approach preclude success at high resolution. One attractive goal, for example, is to image macromolecular machines in action, but radiation-inactivation of enzymatic function severely limits the electron exposures that can be used. Furthermore, although nanometer resolution or better has been claimed in some papers for macromolecular complexes said to be freely suspended in the liquid phase, Brownian motion must limit the achievable resolution to dimensions that are much larger than the macromolecules themselves. While Brownian motion can be avoided by adsorption of particles to a substrate or a thin window, there still is a risk that air drying occurs. We have analyzed publicly-available EM images of GroEL that were putatively obtained in the liquid phase, and show that these particles clearly had been dried. While the original authors argued that the contrast reversal seen in their images must have been due to liquid water scattering 120 keV electrons much more strongly than either vitreous ice or proteins, we show that the particles were likely negatively stained, presumably by remaining buffer salts.

The Egyptian tortoise (Testudo kleinmanni) exhibits remarkable adaptations; yet, significant gaps remain in the understanding of taste bud distribution and the molecular characteristics of its tongue cells. The unique adaptations were investigated using immunofluorescence with six specific antibodies, light microscopy, and scanning electron microscopy. Vimentin and nestin identified superficial taste buds in the lingual body, notably larger than those in the lingual root. The lingual root's fungiform papillae contained deep taste buds. Vimentin showed broad expression across all taste bud cells, while nestin specifically marked basal cells. Co-expression of platelet-derived growth factor receptor alpha (PDGFRα) and cluster of differentiation 34 indicated telocyte-like cells within the papillae. Circular and rectangular hyaline cartilage was also observed, and PDGFRα and SRY-box transcription factor 9 (SOX9) co-expression was demonstrated in chondrocytes, with SOX9 showing higher expression. Cluster of differentiation 19 also identified B-cell lymphocytes in the lingual root. This comprehensive study provides the first application of immunofluorescence to the Egyptian tortoise tongue. It represents new insights into the structure and molecular composition of taste buds of its tongue, highlights its role in physiological adaptation, and contributes to a better understanding of the biology species.

Extensive efforts have been applied to develop workflows for sample preparation of specimens for atom probe tomography at cryogenic temperatures. This is primarily due to the difficulty involved in preparing site-specific lift-out samples at cryogenic temperatures without the assistance of the gas injection system (GIS) as using it under cryogenic conditions leads to nonuniform and difficult to control deposition. Building on the efforts of previously developed GIS-free workflows utilizing redeposition techniques, this work provides an alternative approach using SEMGlu™, which is an electron beam curing adhesive that remains usable at cryogenic temperatures, to both lift out cryogenically frozen samples and mount these samples to Si microarray posts for subsequent redeposition welding. This approach is applicable for a full cryogenic workflow but is particularly useful for nonfully cryogenic workflows such as beam-sensitive samples, samples that mill easily, and samples with challenging geometries. We demonstrate atom probe analysis of silicon samples in both laser pulsing and voltage mode prepared using this workflow, with comparable analytical performance to a presharpened microtip coupon. An application-based example, which directly benefits from this approach, correlative liquid cell transmission electron microscopy and cryogenic atom probe tomography sample preparation, is also shown.

Layered oxide cathodes have attracted wide research interest due to their controllable synthesis, tuneability, and high energy density in sodium-ion batteries (SIBs). However, in layered oxide cathodes, capacity retention is unsatisfactory due to structural changes, and the severity of capacity fading increases at higher voltages. Chemical heterogeneity and concentration gradient lead to the co-existence of multiple phases with lattice mismatch and strain development. To achieve the practical usage of high-density and low-cost layered oxide cathodes for SIBs, it is very important to develop an atomic-scale understanding of the compositional changes in the multi-component cathode. Atom probe tomography (APT) is a very promising technique to analyze chemical composition and heterogeneity in three dimensions (3D) with high spatial resolution and brings insights into possible property- or lifetime-limiting factors. However, APT is underpinned by an intense electric field that can drive preferential alkali metal outward migration and cause in situ de-intercalation of alkali metals that makes APT analysis challenging. As a first report, we show that silver (Ag) coating on SIB cathode APT specimens, deposited inside the focused-ion beam (FIB) at cryogenic temperature, allows for analysis of the compositional heterogeneity in air-sensitive sodium-ion-layered oxide cathode material.

Deciphering the nanoscale architecture of mosquito wings is crucial for understanding species-specific flight adaptations and vectorial behaviors. In this study, we present a comprehensive quantitative analysis of the wing surface morphology of Anopheles darlingi and Anopheles aquasalis. By integrating high-resolution microscopy with Minkowski functionals and multifractal formalism, we reveal pronounced interspecific and dorso-ventral asymmetries in mosquito wing surfaces at both micro- and nanoscales. Atomic force microscopic topographies revealed distinct differences in dorsal versus ventral surface roughness, with An. aquasalis displaying higher elevation variance and denser nanomorphological heterogeneity. Minkowski volume and boundary descriptors showed slower decay and broader distribution for An. aquasalis, especially on its dorsal side, indicative of complex topographic relief. Multifractal spectra, derived from the box-counting method across q = -10 to +10, exhibited larger width (Δα ≈ 1.073) and stronger left-symmetry (H ≈ -0.852) in An. aquasalis, compared to narrower and more symmetric spectra in An. darlingi (Δα ≈ 1.009; H ≈ -0.532). Generalized fractal dimensions (D0 ≈ 2.00; D2 range: 1.951-1.982) and singularity spectra asymmetry (Δf up to -1.732) further differentiated species and wing sides. These multiscale descriptors demonstrate that An. aquasalis, particularly its ventral surface, harbors higher degrees of nanomorphological complexity and textural irregularity.

Fenitrothion is a known environmental contaminant used in public health and agriculture. Gallic acid is a phenolic compound found in numerous plants. This study analyzed the hepatotoxic and nephrotoxic effects of Fenitrothion and evaluated the possible protective effect of gallic acid. Fenitrothion (32 mg/kg body weight/day) and gallic acid (50 mg/kg body weight/day) were administered to male rats by gavage for 28 days. In the present study, the renal (blood urea nitrogen, creatinine, and uric acid levels) and liver (albumin, total protein, aspartate aminotransferase, alanine aminotransferase, total cholesterol, triglyceride, lactate dehydrogenase) function markers in the blood, acetylcholinesterase activities, antioxidant enzyme activities and malondialdehyde level as markers of oxidative stress, and ultrastructural/histopathological/immunohistochemically changes were researched in liver and kidney tissues. Additionally, while superoxide dismutase, catalase, glutathione-S-transferase, and glutathione peroxidase activities were decreased in the liver and kidney tissue of rats treated with fenitrothion, malondialdehyde level was significantly increased. Histopathological and immunohistochemical analyses showed many injuries in the renal and hepatic tissue of fenitrothion-treated animals. Also, the supplementation of gallic acid with fenitrothion significantly improved fenitrothion-induced alterations in renal and liver function markers, antioxidant enzyme activities, acetylcholinesterase activities, malondialdehyde levels, and histological features of tissues.

In this study, the oviposition behavior of the predatory water scorpion beetle Nepa cinerea Linnaeus, 1758 (Hemiptera: Nepidae), morphological structure of eggs, and respiratory horns are described using stereo, light, and electron microscopes. The first recorded N. cinerea specimens from Kırıkkale province were examined. N. cinerea females lay their eggs by sticking them vertically to the substrate. Eggs are elliptical, approximately 1.3 mm wide and 1.63 mm long. Fresh eggs are yellow, darkening. There are 5-8 respiratory horns at the anterior pole of the egg shell. There are numerous air pore openings on the respiratory horn surface. There are hexagonal patterns on the chorion surface. The egg is surrounded by the endochorion with vitelline envelope, the exochorion with tubercle, and the intrachorionic air space between them. The nymph hatches from the egg in 8-10 days. In this study, the development of N. cinerea, which plays an important role in the aquatic ecosystem, the structure and number of respiratory horns in its eggs, and the histology and anatomy of the chorion were emphasized. Clearly determining the preadult egg period that will ensure the continuity of the species will make a significant contribution to biodiversity and biocontrol studies.