Leafcutter ants are dominant herbivores in the Neotropics and rely on a fungus (Leucoagaricus gongylophorus) to transform freshly gathered leaves into a source of nourishment rather than consuming the vegetation directly. Here we report two virus-like particles that were isolated from L. gongylophorus and observed using transmission electron microscopy. RNA sequencing identified two +ssRNA mycovirus strains, Leucoagaricus gongylophorus tymo-like virus 1 (LgTlV1) and Leucoagaricus gongylophorus magoulivirus 1 (LgMV1). Genome annotation of LgTlV1 (7401 nt) showed conserved domains for methyltransferase, endopeptidase, viral RNA helicase, and RNA-dependent RNA polymerase (RdRp). The smaller genome of LgMV1 (2636 nt) contains one open reading frame encoding an RdRp. While we hypothesize these mycoviruses function as symbionts in leafcutter farming systems, further study will be needed to test whether they are mutualists, commensals, or parasites.

BACKGROUND: The increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains resistant to non-beta-lactam antimicrobials poses a significant challenge in treating severe MRSA bloodstream infections. This study explores resistance development and mechanisms in MRSA isolates, especially after the first dalbavancin-resistant MRSA strain in our hospital in 2016.
METHODS: This study investigated 55 MRSA bloodstream isolates (02/2015-02/2021) from the University Hospital of the Medical University of Vienna, Austria. The MICs of dalbavancin, linezolid, and daptomycin were assessed. Two isolates (16-33 and 19-362) resistant to dalbavancin were analyzed via whole-genome sequencing, with morphology evaluated using transmission electron microscopy (TEM).
RESULTS: S.aureus BSI strain 19-362 had two novel missense mutations (p.I515M and p.A606D) in the pbp2 gene. Isolate 16-33 had a 534 bp deletion in the DHH domain of GdpP and a SNV in pbp2 (p.G146R). Both strains had mutations in the rpoB gene, but at different positions. TEM revealed significantly thicker cell walls in 16-33 (p < 0.05) compared to 19-362 and dalbavancin-susceptible strains. None of the MRSA isolates showed resistance to linezolid or daptomycin.
CONCLUSIONS: In light of increasing vancomycin resistance reports, continuous surveillance is essential to comprehend the molecular mechanisms of resistance in alternative MRSA treatment options. In this work, two novel missense mutations (p.I515M and p.A606D) in the pbp2 gene were newly identified as possible causes of dalbavancin resistance.

UNASSIGNED: Non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac (DCF), form a significant group of environmental contaminants. When the toxic effects of DCF on plants are analyzed, authors often focus on photosynthesis, while mitochondrial respiration is usually overlooked. Therefore, an in vivo investigation of plant mitochondria functioning under DCF treatment is needed. In the present work, we decided to use the green alga Chlamydomonas reinhardtii as a model organism.
UNASSIGNED: Synchronous cultures of Chlamydomonas reinhardtii strain CC-1690 were treated with DCF at a concentration of 135.5 mg × L-1, corresponding to the toxicological value EC50/24. To assess the effects of short-term exposure to DCF on mitochondrial activity, oxygen consumption rate, mitochondrial membrane potential (MMP) and mitochondrial reactive oxygen species (mtROS) production were analyzed. To inhibit cytochrome c oxidase or alternative oxidase activity, potassium cyanide (KCN) or salicylhydroxamic acid (SHAM) were used, respectively. Moreover, the cell\'s structure organization was analyzed using confocal microscopy and transmission electron microscopy.
UNASSIGNED: The results indicate that short-term exposure to DCF leads to an increase in oxygen consumption rate, accompanied by low MMP and reduced mtROS production by the cells in the treated populations as compared to control ones. These observations suggest an uncoupling of oxidative phosphorylation due to the disruption of mitochondrial membranes, which is consistent with the malformations in mitochondrial structures observed in electron micrographs, such as elongation, irregular forms, and degraded cristae, potentially indicating mitochondrial swelling or hyper-fission. The assumption about non-specific DCF action is further supported by comparing mitochondrial parameters in DCF-treated cells to the same parameters in cells treated with selective respiratory inhibitors: no similarities were found between the experimental variants.
UNASSIGNED: The results obtained in this work suggest that DCF strongly affects cells that experience mild metabolic or developmental disorders, not revealed under control conditions, while more vital cells are affected only slightly, as it was already indicated in literature. In the cells suffering from DCF treatment, the drug influence on mitochondria functioning in a non-specific way, destroying the structure of mitochondrial membranes. This primary effect probably led to the mitochondrial inner membrane permeability transition and the uncoupling of oxidative phosphorylation. It can be assumed that mitochondrial dysfunction is an important factor in DCF phytotoxicity. Because studies of the effects of NSAIDs on the functioning of plant mitochondria are relatively scarce, the present work is an important contribution to the elucidation of the mechanism of NSAID toxicity toward non-target plant organisms.

BACKGROUND: Enhancing the antibacterial properties of polymethyl methacrylate (PMMA) dental resins is crucial in preventing secondary infections following dental procedures. Despite the necessity for such improvement, a universally applicable method for augmenting the antibacterial properties of PMMA without compromising its mechanical properties and cytotoxicity remains elusive. Consequently, this study aims to address the aforementioned challenges by developing and implementing a composite material known as zinc oxide/graphene oxide (ZnO/GO) nanocomposites, to modify the PMMA.
METHODS: ZnO/GO nanocomposites were successfully synthesized by a one-step procedure and fully characterized by TEM, EDS, FTIR and XRD. Then the physical and mechanical properties of PMMA modified by ZnO/GO nanocomposites were evaluated through water absorption and solubility test, contact angle test, three-point bending tests, and compression test. Furthermore, the biological properties of the modified PMMA were evaluated by direct microscopic colony count method, crystal violet staining and CCK-8.
RESULTS: The results revealed that ZnO/GO nanocomposites were successfully constructed. When the concentration of nanocomposites in PMMA was 0.2 wt. %, the flexural strength of the resin was increased by 23.4%, the compressive strength was increased by 31.1%, and the number of bacterial colonies was reduced by 60.33%. Meanwhile, It was found that the aging of the resin did not affect its antibacterial properties, and CCK-8 revealed that the modified PMMA had no cytotoxicity.
CONCLUSIONS: ZnO/GO nanocomposites effectively improved the antibacterial properties of PMMA. Moreover, the mechanical properties of the resin were improved by adding ZnO/GO nanocomposites at a lower range of concentrations.

Background: Telocytes are interstitial stromal cells identified in various human organs, including the kidney. Their presence and role in human diabetic kidney disease remain unknown. Methods: To identify and localize telocytes in glomerular and tubule-interstitial compartments, both normal and diabetic human renal tissues were examined using immunohistochemistry, immunofluorescence, and transmission electron microscopy. Results: Renal telocytes are elongated interstitial cells with long, thin telopodes, showing alternating thin and thick segments. They expressed CD34, Nestin, α-SMA, and Vimentin markers. Occasionally, c-Kit expression was observed in some rounded and spindle cells, while no positivity was detected for PDGFR-β and NG2. Telocytes were identified around Bowman\'s capsule, tubules, and peritubular capillaries in both normal and diabetic conditions. In diabetic renal samples, there was a significant increase in α-SMA expressing telocytes, leading to periglomerular fibrosis. These telocytes also exhibited a synthetic phenotype with proteoglycan deposition in the extracellular matrix and, in some cases, showed pre-adipocytic differentiation. Conclusions: Telocytes were identified in normal and diabetic human kidneys. These cells form an elastic mechanical scaffold in the interstitium and are present in all renal cortical compartments. In diabetic samples, their increased α-SMA expression and synthetic phenotype suggest their potential role in the pathogenesis of diabetic nephropathy.

BACKGROUND: Clinical evidence suggests an association between phosphate concentrations in aqueous humor and the risk of intraocular lens (IOL) calcification. To test this hypothesis the influence of different phosphate concentrations on IOL calcification was evaluated in an in vitro electrophoresis model.
METHODS: 20 IOLs of two hydrophilic IOL models (CT Spheris 204, Zeiss; Lentis L-313, Oculentis) and one hydrophobic control IOL model (Clareon CNA0T0, Alcon) were exposed to physiologic and elevated phosphate concentrations, similar to diabetic aqueous humor. IOL calcification was analyzed by alizarin red staining, von Kossa staining, scanning electron microscopy, energy dispersive x-ray spectroscopy and transmission electron microscopy with electron diffraction.
RESULTS: Higher phosphate concentrations were associated with IOL calcification. Analyses of IOL surfaces and cross-sections documented calcification in no CT Spheris and 4 Lentis IOLs following exposure to 10 mM Na2HPO4, compared with 7 and 11 positive analyses following exposure to 14 mM Na2HPO4, respectively. Furthermore, a clear association between IOL calcification and the duration of electrophoresis was demonstrated, confirming increased phosphate concentrations and duration of exposure as risk factors of IOL calcification.
CONCLUSIONS: Findings suggest that higher phosphate concentrations in aqueous humor, as seen in diabetic patients, contribute to an increased IOL calcification risk, potentially explaining clinical observations showing an increased risk of IOL calcification in patients with diabetes.

UNASSIGNED: The Harderian gland in domestic birds is a major paraocular excretory gland that has an important role in tear production as well as in the immune protection of the conjunctiva surface.
UNASSIGNED: The aim of this research was to investigate the arterial and venous supply of the gland in hens and provide valuable and useful information for future research.
UNASSIGNED: The research was conducted on 26 adult hens, provenience of Lohmann Brown. For the identification and determination of blood vessels, we used the vascular corrosion cast technique in conjunction with the transmission electron microscope (TEM).
UNASSIGNED: The casts showed that the gland receives the arterial supply via branches of a. ophthalmotemporalis and a. nasalis communis and these arteries are accompanied by the corresponding veins. Ultrastructural analyses showed the presence of fenestrated capillaries, which indicates the possibility for permeability of larger molecules.
UNASSIGNED: The present research gives important and detailed information about the arterial and venous supply of the Harderian gland in hens that may serve as guidelines for future vascular and morphological investigations.

Synthetic membrane nanopores made of DNA are promising systems to sense and control molecular transport in biosensing, sequencing, and synthetic cells. Lumen-tunable nanopore like the natural ion channels and systematically increasing the lumen size have become long-standing desires in developing nanopores. Here, we design a triangular DNA nanopore with a large tunable lumen. It allows in-situ transition from expanded state to contracted state without changing its stable triangular shape, and vice versa, in which specific DNA bindings as stimuli mechanically pinch and release the three corners of the triangular frame. Transmission electron microscopy images and molecular dynamics simulations illustrate the stable architectures and the high shape retention. Single-channel current recordings and fluorescence influx studies demonstrate the low-noise repeatable readouts and the controllable cross-membrane macromolecular transport. We envision that the proposed DNA nanopores could offer powerful tools in molecular sensing, drug delivery, and the creation of synthetic cells.

Synaptic proteins need to be replaced regularly, to maintain function and to prevent damage. It is unclear whether this process, known as protein turnover, relates to synaptic morphology. To test this, we relied on nanoscale secondary ion mass spectrometry, to detect newly synthesized synaptic components in the brains of young adult (6 mo old) and aged mice (24 mo old), and on transmission electron microscopy, to reveal synapse morphology. Several parameters correlated to turnover, including pre- and postsynaptic size, the number of synaptic vesicles and the presence of a postsynaptic nascent zone. In aged mice, the turnover of all brain compartments was reduced by ∼20%. The turnover rates of the pre- and postsynapses correlated well in aged mice, suggesting that they are subject to common regulatory mechanisms. This correlation was poorer in young adult mice, in line with their higher synaptic dynamics. We conclude that synapse turnover is reflected by synaptic morphology.

UNASSIGNED: High altitude retinopathy (HAR) is a retinal functional disorder caused by inadequate adaptation after exposure to high altitude. However, the cellular and molecular mechanisms underlying retinal dysfunction remain elusive. Retinal ganglion cell (RGC) injury is the most important pathological basis for most retinal and optic nerve diseases. Studies focusing on RGC injury after high-altitude exposure (HAE) are scanty. Therefore, the present study sought to explore both functional and morphological alterations of RGCs after HAE.
UNASSIGNED: A mouse model of acute hypobaric hypoxia was established by mimicking the conditions of a high altitude of 5000 m. After HAE for 2, 4, 6, 10, 24, and 72 hours, the functional and morphological alterations of RGCs were assessed using retinal hematoxylin and eosin (H&E) sections, retinal whole mounts, transmission electron microscopy (TEM), and the photopic negative response (PhNR) of the electroretinogram.
UNASSIGNED: Compared with the control group, the thickness of the ganglion cell layer and retinal nerve fiber layer increased significantly, RGC loss remained significant, and the amplitudes of a-wave, b-wave, and PhNR were significantly reduced after HAE. In addition, RGCs and their axons exhibited an abnormal ultrastructure after HAE, including nuclear membrane abnormalities, uneven distribution of chromatin in the nucleus, decreased cytoplasmic electron density, widening and vacuolization of the gap between axons, loosening and disorder of myelin sheath structure, widening of the gap between myelin sheath and axon membrane, decreased axoplasmic density, unclear microtubule and nerve fiber structure, and abnormal mitochondrial structure (mostly swollen, with widened membrane gaps and reduced cristae and vacuolization).
UNASSIGNED: The study findings confirm that the morphology and function of RGCs are damaged after HAE. These findings lay the foundation for further study of the specific molecular mechanisms of HAR and promote the effective prevention.