Electron Microscopy Data Research Articles

Antioxidant Activity as an Indicator of the Efficiency of Plant Extract-Mediated Synthesis of Zinc Oxide Nanoparticles.

The green synthesis of zinc oxide nanoparticles (ZnO NPs) using a diverse range of plant species has been extensively reported. Despite the success achieved by biogenic synthesis, there are problems with the control and prediction of the properties of ZnO NPs, due to phytochemical diversity between plant species. In this sense, the main objective of our work was to investigate the effect of the antioxidant activity (AA) of plant extracts on the physicochemical characteristics of ZnO NPs (production yield, chemical composition, polydispersity index (PDI), surface charge (ζ-potential) and average particle size). In order to accomplish this objective, four plant extract with different antioxidant activities were used: Galega officinalis, Buddleja globosa, Eucalyptus globulus, and Aristotelia chilensis. Phytochemical screening, quantitative analysis of phenolic compounds and antioxidant activity determination of the different extracts were carried out. Chemical species such as catechin, malvidin, quercetin, caffeic acid, and ellagic acid were the dominant components, found in the extracts studied. The A. chilensis extract showed the highest value of total phenolic compounds (TPC) and AA, followed by E. globulus, B. globosa and G. officinalis. Zetasizer, Fourier-transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) data show that plant extracts with lower AA leads to a decrease in the yield of ZnO NPs and an increase in the amount of residual organic extract that remains on the particles. The latter caused an increase in the average particle size, PDI and ζ-potential as a consequence of agglomeration and particle coarsening. Our result suggest that it is possible to use the AA as an indicator of the potential reducing capacity of plant extracts. In this way it is possible to guarantee the reproducibility of the synthesis process as well as ensure the formation of ZnO NPs with desired characteristics.

High-quality sandstone reservoir evaluation and prediction in a half-graben rift sag under the influence of igneous intrusions, Songliao Basin, Northeast China

Tight sandstone reservoirs of continental lake basins are one of the most important types of unconventional hydrocarbon resources. The first member of the Yingcheng Formation (k1y1) in Baojia Sag, Songliao basin, is an important tight sandstone reservoir and also a region rich in hydrocarbon. However, volcanic rock intrusions increase the stratum thickness and change the characteristics of the reservoirs, thus making the distribution of high-quality reservoirs more difficult to predict. Therefore, according to the identification of sequence boundaries, the five 4th-order sequences of k1y1 in Baojia sag are divided, into SQ1–SQ5, which are mainly dominated by lacustrine and fan-delta depositional systems. The stratigraphic characteristics in the study area were affected by two stages of volcanic activity. In the first stage, a large area of tuff was developed in SQ5. In the second stage, sheets of intrusive rocks were formed in SQ1–SQ4. Through the identification of cast thin sections and Scanning Electron Microscopy (SEM) data, the types of reservoir micro-pores mainly develop primary pores, microfractures, intergranular, and intragranular dissolved pores. Given the complex strata under the interference of volcanic rocks, it is considered that sandstone with a 10–40% argillaceous content is a high-quality reservoir. The results showed that under the background of episodic tectonic activities, humid paleoclimate, and sufficient paleoprovenance, large-area fan-deltas of SQ2 and SQ4 are developed in both steep slope and gentle slope zones. Compared with SQ1 and SQ3, small-scale fan-deltas are formed under the background of a stable structure and arid paleoclimate. The reservoir quality gradually improved from SQ1 to SQ4, this is mainly due to the progressive reduction of reservoir argillaceous content, the gradual reduction of compaction, and the gradual enhancement of dissolution, resulting in the expansion of pore throats to improve pore connectivity. Geostatistical inversion based on argillaceous content was proven to be more effective than wave impedance inversion as it distinguishes lithology and predicts high-quality reservoirs disturbed by volcanic rocks. Comprehensive analyses show that the sandstone of SQ3 and SQ4 with a 10–40% argillaceous content is the highest quality of reservoirs, which interact with lacustrine source rocks and easily form “self-generated and self-stored” and “the lower-generation and upper-storage” patterns of hydrocarbon reservoirs. The prediction method and distribution law of high-quality reservoirs under the influence of volcanoes can provide guidance for hydrocarbon exploration and development.

Silver metal-nanocomposites based on 1-vinyl-1,2,4-triazole copolymer with methacrylic acid

Silver nanocomposites in the matrix of a copolymer of 1-vinyl-1,2,4-triazole with methacrylic acid were synthesized by the electrochemical method by combining the process of electrochemical polymerization with cathodic precipitation of metals on metal electrodes. Structure and composition of the obtained nanocomposites and nanocoatings were recorded using UV, IR, atomic absorption and X-ray spectroscopy, thermogravimetric and elemental analyses. Transmission electron microscopy data show that the synthesized nanocomposites consist of particles with a diameter of 1 to 12 nm, predominantly spherical.

High-quality vertically aligned InAs nanowires grown by molecular-beam epitaxy using Ag–In alloy segregation

InAs nanowires show important potential applications in novel nanoelectronic devices, infrared optoelectronic devices and quantum devices, and all these applications require controllable growth of the InAs nanowires. However, the growth direction of metal-assisted InAs nanowires on Si substrates is often random. Here, we develop a new approach to grow vertically aligned InAs nanowires on Si (111) substrates by molecular-beam epitaxy using Ag as catalysts. The vertically aligned one-dimensional InAs nanowires are grown on the parasitic two-dimensional InAs film on the Si substrates by using the Ag nanoparticles segregated from Ag–In alloy catalysts. The diameters of the vertically aligned InAs nanowires obtained by this method are mainly distributed between 20 and 50 nm. Detailed transmission electron microscope data show that the nanowires with thinner diameters tend to have less stacking faults and twin defects and high crystal quality pure wurtzite nanowires can be obtained. Using these vertically aligned InAs nanowires as the channel material of field effect transistors, we have obtained a field-effect mobility of ∼2800 cm2 V−1 s−1 and an I on/I off ratio of ∼104 at room temperature. Our work provides a new method for the controlled growth of high-quality vertically aligned InAs nanowires on Si substrates.

Using sugars as both reducing and cryoprotectants of freeze-dried silver nanoparticles for improving long-term stability

This study has proposed using maltose and lactose as reducing and cryoprotectant agents to improve silver nanoparticles’ long-term stability (AgNPs). For the reducing performance, UV–vis spectroscopy revealed that both sugars could be used as reducing and eventually as capping agents of the as-synthesized AgNPs. For cryoprotective performance, the UV–vis spectroscopy and dynamic light scattering (DLS) showed that both sugars could prevent maltose-reduced (coded as AgNP-M) and lactose-reduced (coded as AgNP-L) AgNPs from irreversible aggregation under freezing and freeze-drying. For long-term stability, UV–vis spectroscopy, DLS, and transmission electron microscopy (TEM) data revealed that aged freeze-dried AgNP-M and AgNP-L were generally more stable than their non-freeze-dried counterparts under accelerated storage conditions. Likewise, the antibacterial and cytotoxic activities of aged freeze-dried AgNP-M and AgNP-L were close to those observed in their as-synthesized counterparts. Otherwise, aged non-freeze-dried AgNP-L demonstrated reduced antibacterial and cytotoxic activities, while such behavior was not present in the aged non-freeze-dried AgNP-M. These findings proved that maltose and lactose could emerge as a green alternative to synthesize AgNPs and simultaneously cryoprotect them during freezing and freeze-drying to achieve long-term stability.

SynapseCLR: Uncovering features of synapses in primary visual cortex through contrastive representation learning

3D electron microscopy (EM) connectomics image volumes are surpassing 1mm3, providing information-dense, multi-scale visualizations of brain circuitry and necessitating scalable analysis techniques. We present SynapseCLR, a self-supervised contrastive learning method for 3D EM data, and use it to extract features of synapses from mouse visual cortex. SynapseCLR feature representations separate synapses by appearance and functionally important structural annotations. We demonstrate SynapseCLR's utility for valuable downstream tasks, including one-shot identification of defective synapse segmentations, dataset-wide similarity-based querying, and accurate imputation of annotations for unlabeled synapses, using manual annotation of only 0.2% of the dataset's synapses. In particular, excitatory versus inhibitory neuronal types can be assigned with >99.8% accuracy to individual synapses and highly truncated neurites, enabling neurite-enhanced connectomics analysis. Finally, we present a data-driven, unsupervised study of synaptic structural variation on the representation manifold, revealing its intrinsic axes of variation and showing that representations contain inhibitory subtype information.

Fast Dynamic Synthesis of MIL-68(In) Thin Films in High Optical Quality for Optical Cavity Sensing.

Fabrication of metal-organic framework (MOF) thin films rigidly anchored on suitable substrates is a crucial prerequisite for the integration of these porous hybrid materials into electronic and optical devices. Thus, far, the structural variety for MOF thin films available through layer-by-layer deposition was limited, as the preparation of those surface-anchored metal-organic frameworks (SURMOFs) has several requirements: mild conditions, low temperatures, day-long reaction times, and nonaggressive solvents. We herein present a fast method for the preparation of the MIL SURMOF on Au-surfaces under rather harsh conditions: Using a dynamic layer-by-layer synthesis for MIL-68(In), thin films of adjustable thickness between 50 and 2000 nm could be deposited within only 60 min. The MIL-68(In) thin film growth was monitored in situ using a quartz crystal microbalance. In-plane X-ray diffraction revealed oriented MIL-68(In) growth with the pore-channels of this interesting MOF aligned parallel to the support. Scanning electron microscopy data demonstrated an extraordinarily low roughness of the MIL-68(In) thin films. Mechanical properties and lateral homogeneity of the layer were probed through nanoindentation. These thin films showed extremely high optical quality. By applying a poly(methyl methacrylate) layer and further depositing an Au-mirror to the top, a MOF optical cavity was fabricated that can be used as a Fabry-Perot interferometer. The MIL-68(In)-based cavity showed a series of sharp resonances in the ultraviolet-visible regime. Changes in the refractive index of MIL-68(In) caused by exposure to volatile compounds led to pronounced position shifts of the resonances. Thus, these cavities are well suited to be used as optical read-out sensors.

TRPC1 channel clustering during store-operated Ca2+ entry in keratinocytes.

Skin is the largest organ in the human body with ∼95% of its surface made up of keratinocytes. These cells maintain a healthy skin barrier through regulated differentiation driven by Ca2+-transcriptional coupling. Many important skin conditions arise from disruption of this process although not all stages are fully understood. We know that elevated extracellular Ca2+ at the skin surface is detected by keratinocyte Gαq-coupled receptors that signal to empty endoplasmic reticulum Ca2+ stores. Orai channel store-operated Ca2+ entry (SOCE) and Ca2+ influx via "canonical" transient receptor potential (TRPC)-composed channels then activates transcription factors that drive differentiation. While STIM-mediated activation of Orai channels following store depletion is well defined, how TRPC channels are activated is less clear. Multiple modes of TRPC channel activation have been proposed, including 1) independent TRPC activation by STIM, 2) formation of Orai-TRPC-STIM complexes, and 3) the insertion of constitutively-active TRPC channels into the membrane during SOCE. To help distinguish between these models, we used high-resolution microscopy of intact keratinocyte (HaCaT) cells and immunogold transmission electron microscopy (TEM) of HaCaT plasma membrane sheets. Our data shows no evidence of significant insertion of Orai1 or TRPC subunits into the membrane during SOCE. Analysis of transmission electron microscopy data shows that during store-depletion and SOCE, Orai1 and TRPC subunits form separate membrane-localized clusters that migrate towards each other. This clustering of TRPC channel subunits in keratinocytes may support the formation of TRPC-STIM interactions at ER-plasma membrane junctions that are distinct from Orai-STIM junctions.

Investigation on the Photodegradation Stability of Acrylic Acid-Grafted Poly(butylene carbonate-co-terephthalate)/Organically Modified Layered Zinc Phenylphosphonate Composites.

The application efficiency of biodegradable polymers used in a natural environment requires improved resistance to ultraviolet (UV) photodegradation. In this report, 1,6-hexanediamine modified layered zinc phenylphosphonate (m-PPZn), utilized as a UV protection additive for acrylic acid-grafted poly(butylene carbonate-co-terephthalate) (g-PBCT), was successfully fabricated and compared to the solution mixing process. Experimental data of both wide-angle X-ray diffraction and transmission electron microscopy reveal that the g-PBCT polymer matrix was intercalated into the interlayer spacing of m-PPZn, which was approximately delaminated in the composite materials. The evolution of photodegradation behavior for g-PBCT/m-PPZn composites was identified using Fourier transform infrared spectroscopy and gel permeation chromatography after being artificially irradiated by a light source. The change of carboxyl group produced via photodegradation was used to show the enhanced UV protection ability of m-PPZn in the composite materials. All results indicate that the carbonyl index of the g-PBCT/m-PPZn composite materials after photodegradation for 4 weeks was extensively lower than that of the pure g-PBCT polymer matrix. These findings were also supported by the decrease in the molecular weight of g-PBCT after photodegradation for 4 weeks, from 20.76% to 8.21%, with the loading of 5 wt% m-PPZn content. Both observations were probably owing to the better UV reflection ability of m-PPZn. This investigation shows, through typical methodology, a significant advantage of fabricating the photodegradation stabilizer to enhance the UV photodegradation behavior of the biodegradable polymer using an m-PPZn compared to other UV stabilizer particles or additives.

Self-Assembly Polymersomes Based on Sulfite Lignins with Biological Activity

A relatively simple way of obtaining polymer vesicles via self-assembly in an aqueous acetone medium is proposed on the basis of biologically active polymer sulfite lignin (lignosulfonate). The size and morphology of polymersomes are controlled according to molecular weight (46.300–60.000 Da), the concentration of lignosulfonate (CLS 0.10–1.28 g/dm3), and the content of acetone (φAc 0.6–4.0 vol %) in the suspension. The resulting polymersomes are characterized by sizes of 200–350 nm, a polydispersity index of 0.25–0.18, and a ζ potential of −26.3 to −51.0 ± 2.2 mV. Air-dried powders of polymersomes isolated from the corresponding suspensions are polydisperse, with sizes ranging from 40 to 300 nm. The morphology of polymersomes is confirmed by electron microscopy data (SEM, TEM, and AFM). In light of the biological activity of lignosulfonate, polymersomes derived from it can potentially be used in such biomedical applications as targeted drug and gene delivery, enzymatic catalysis, and optical imaging in vivo.

AtomVision: A Machine Vision Library for Atomistic Images.

Computer vision techniques have immense potential for materials design applications. In this work, we introduce an integrated and general-purpose AtomVision library that can be used to generate and curate microscopy image (such as scanning tunneling microscopy and scanning transmission electron microscopy) data sets and apply a variety of machine learning techniques. To demonstrate the applicability of this library, we (1) establish an atomistic image data set of about 10 000 materials with large structural and chemical diversity, (2) develop and compare convolutional and atomistic line graph neural network models to classify the Bravais lattices, (3) demonstrate the application of fully convolutional neural networks using U-Net architecture to pixelwise classify atom versus background, (4) use a generative adversarial network for super resolution, (5) curate an image data set on the basis of natural language processing using an open-access arXiv data set, and (6) integrate the computational framework with experimental microscopy images for Rh, Fe3O4, and SnS systems. The AtomVision library is available at https://github.com/usnistgov/atomvision.

Limosilactobacillus fermentum 3872 That Produces Class III Bacteriocin Forms Co-Aggregates with the Antibiotic-Resistant Staphylococcus aureus Strains and Induces Their Lethal Damage

LF3872 was isolated from the milk of a healthy lactating and breastfeeding woman. Earlier, the genome of LF3872 was sequenced, and a gene encoding unique bacteriocin was discovered. We have shown here that the LF3872 strain produces a novel thermolabile class III bacteriolysin (BLF3872), exhibiting antimicrobial activity against antibiotic-resistant Staphylococcus aureus strains. Sequence analysis revealed the two-domain structural (lysozyme-like domain and peptidase M23 domain) organization of BLF3872. At least 25% residues of this protein are expected to be intrinsically disordered. Furthermore, BLF3872 is predicted to have a very high liquid-liquid phase separation. According to the electron microscopy data, the bacterial cells of LF3872 strain form co-aggregates with the S. aureus 8325-4 bacterial cells. LF3872 produced bacteriolysin BLF3872 that lyses the cells of the S. aureus 8325-4 mastitis-inducing strain. The sensitivity of the antibiotic-resistant S. aureus collection strains and freshly isolated antibiotic-resistant strains was tested using samples from women with lactation mastitis; the human nasopharynx and oral cavity; the oropharynx of pigs; and the cows with a diagnosis of clinical mastitis sensitive to the lytic action of the LF3872 strain producing BLF3872. The co-cultivation of LF3872 strain with various antibiotic-resistant S. aureus strains for 24 h reduced the level of living cells of these pathogens by six log. The LF3872 strain was found to be able to co-aggregate with all studied S. aureus strains. The cell-free culture supernatant of LF3872 (CSLF3872) induced S. aureus cell damage and ATP leakage. The effectiveness of the bacteriolytic action of LF3872 strain did not depend on the origin of the S. aureus strains. The results reported here are important for the creation of new effective drugs against antibiotic-resistant strains of S. aureus circulating in humans and animals.

Synthesis and Functional Characterization of CoxFe3−xO4-BaTiO3 Magnetoelectric Nanocomposites for Biomedical Applications

Nowadays, magnetoelectric nanomaterials are on their way to finding wide applications in biomedicine for various cancer and neurological disease treatment, which is mainly restricted by their relatively high toxicity and complex synthesis. This study for the first time reports novel magnetoelectric nanocomposites of CoxFe3-xO4-BaTiO3 series with tuned magnetic phase structures, which were synthesized via a two-step chemical approach in polyol media. The magnetic CoxFe3-xO4 phases with x = 0.0, 0.5, and 1.0 were obtained by thermal decomposition in triethylene glycol media. The magnetoelectric nanocomposites were synthesized by the decomposition of barium titanate precursors in the presence of a magnetic phase under solvothermal conditions and subsequent annealing at 700 °C. X-ray diffraction revealed the presence of both spinel and perovskite phases after annealing with average crystallite sizes in the range of 9.0-14.5 nm. Transmission electron microscopy data showed two-phase composite nanostructures consisting of ferrites and barium titanate. The presence of interfacial connections between magnetic and ferroelectric phases was confirmed by high-resolution transmission electron microscopy. Magnetization data showed expected ferrimagnetic behavior and σs decrease after the nanocomposite formation. Magnetoelectric coefficient measurements after the annealing showed non-linear change with a maximum of 89 mV/cm*Oe with x = 0.5, 74 mV/cm*Oe with x = 0, and a minimum of 50 mV/cm*Oe with x = 0.0 core composition, that corresponds with the coercive force of the nanocomposites: 240 Oe, 89 Oe and 36 Oe, respectively. The obtained nanocomposites show low toxicity in the whole studied concentration range of 25-400 μg/mL on CT-26 cancer cells. The synthesized nanocomposites show low cytotoxicity and high magnetoelectric effects, therefore they can find wide applications in biomedicine.

Nanoparticle Tracking Analysis: Enhanced Detection of Transparent Materials

AbstractThis study proposes a novel and simple in‐house design of a nanoparticle tracking analysis (NTA) device for the online characterization of nanoparticles in an aqueous solution. The particle size distribution of two sets of model nanoparticles, for example, transparent (SiO2) and opaque (TiO2) materials with respect to water as a dispersion medium could be successfully analyzed. Experiments are conducted using two different laser wavelengths of 632.8 (red) and 510 nm (green) and a range of concentrations. The accuracy of the green laser is larger compared to the red laser for all particle concentrations used. The measured average diameter using the presented in‐house NTA setup is in the acceptable range compared to the electron microscopy data. The average diameter of the transparent (SiO2) and opaque (TiO2) samples is calculated as 36.29 and 27.26 nm using NTA, 36.44 and 27.8 nm analyzing field emission scanning electron microscopy images, and 23.97 and 19.7 nm analyzing transmission electron microscopy images. In the new viewing sample holder, nanoparticles undergo mere Brownian motion with no bulk drift velocity. The effect of solid concentration and wavelength of the laser light on the performance of the NTA sensor is investigated, and the optimal concentration range for model particles is reported.

3D-Printed Nanoscale-Thick Silver Thin Films for Electrochemical Sensing

Nanoscale-thick silver thin films (Ag-NTF) on indium tin oxide-coated glasses are fabricated at different deposition potentials (1.0–5.0 V) using an electrochemical three-dimensional (3D) printing process. The printing process is carried out using a nozzle with a diameter of 0.25 mm and a printing speed of 1.0 mm s–1. The X-ray diffraction (XRD) data showed that the mean crystallite size of Ag is 17 nm. The optical and field emission scanning electron microscopy (FESEM) data revealed the uniform NTF nature of the Ag-NTF electrode. Transmission electron microscopy (TEM) data showed that Ag-NTF electrode particles have a spherical shape with an average size of 21 nm. Furthermore, electrochemical surface activity study showed that samples deposited at 3.0 V have the best electrochemical activity, and hence, the same are used to develop hydrogen peroxide sensors. The sensing measurements are done using a 0.1 M phosphate buffer saline (PBS) electrolyte. The sensitivity of the Ag-NTF comes out to be 25 ± 1 μA mM–1 cm–2 with a lower detection limit (LOD) of 1.0 μM. The selectivity of the electrode is tested using various interfering chemicals. The developed sensors showed excellent selectivity toward H2O2. Finally, the applicability of the Ag-NTF electrodes toward real-life samples is shown using bovine albumin serum (BSA) and rainwater. For the first time, this study has demonstrated the use of an electrochemical 3D printing process to fabricate electrodes for H2O2 sensing. The inherent nature of the process has the capability to eliminate the conventional tedious route to make such electrodes and to provide a one-step and efficient solution.

MorphoFeatures for unsupervised exploration of cell types, tissues, and organs in volume electron microscopy.

Electron microscopy (EM) provides a uniquely detailed view of cellular morphology, including organelles and fine subcellular ultrastructure. While the acquisition and (semi-)automatic segmentation of multicellular EM volumes are now becoming routine, large-scale analysis remains severely limited by the lack of generally applicable pipelines for automatic extraction of comprehensive morphological descriptors. Here, we present a novel unsupervised method for learning cellular morphology features directly from 3D EM data: a neural network delivers a representation of cells by shape and ultrastructure. Applied to the full volume of an entire three-segmented worm of the annelid Platynereis dumerilii, it yields a visually consistent grouping of cells supported by specific gene expression profiles. Integration of features across spatial neighbours can retrieve tissues and organs, revealing, for example, a detailed organisation of the animal foregut. We envision that the unbiased nature of the proposed morphological descriptors will enable rapid exploration of very different biological questions in large EM volumes, greatly increasing the impact of these invaluable, but costly resources.

Sensitivity enhancement of gold nanospheres assisted CO2 laser tapered optical fiber for refractive index sensor

Tapered optical fibers (TOFs) have been intensively used as sensors due to their high sensitivity, simple structure, and excellent coupling efficiency. In this paper, we reported the successful rapid tapering of single mode and multimode fibers using CO2 laser beam at working wavelength of 10.6 μm. Clean and symmetric tapers could be produced in just 5 s using this method. Arduino-based microcontroller was included in the tapering set-up to precisely control the fiber pulling speed and distance. Smaller waist diameters that were observed in multimode than in single mode fibers generated more evanescent waves on the cladding of tapered multimode fibers (TMMFs). This implied that TMMFs performed better refractive index (RI) sensitivity, within the range of 1.3325–1.4266, than tapered single mode fibers (TSMFs). Furthermore, localized surface plasmon resonance (LSPR) effect was coupled with evanescent wave through AuNSs immobilization on the TOF surface. The AuNSs having average particle diameter of 12.70 nm was synthesized by citrate reduction route. The formation of AuNSs was confirmed by (ultraviolet–visible) UV–vis and high-resolution transmission electron microscopy (HRTEM) data. Self-assembly monolayer approach was conducted to immobilize AuNSs on the 3-mercaptopropyl trimethoxysilane (MPTMS)-functionalized surface of the TOFs. The AuNSs immobilization on TMMFs could improve the sensitivity up to 122 %. Besides sensitive to RI changes, the sensors were also excellent in terms of repeatability and reversibility performances. Finally, this paper described the amplitude modality-based RI sensing mechanism due to evanescent wave and LSPR effects.

The anti-tumor activities of coenzyme Q0 through ROS-mediated autophagic cell death in human triple-negative breast cells

Coenzyme Q0 (CoQ0) obtained from Antrodia camphorata has therapeutic benefits in cancer treatment. Our previous findings in vivo and in vitro have shown that CoQ0 affects triple-negative breast cancer cells (TNBCs) by blocking EMT and metastasis. The current study investigated the cancer-preventive activities of CoQ0 on TNBC MDA-MB-468 and 231 cells by activating apoptotic and autophagic cell death. The CoQ0 treatment reduced colony development and proliferation in TNBC cells. In addition, CoQ0 triggered death activation by caspase-3 stimulation, PARP cleavage, and significantly affected Bax/Bcl-2 regulation. Autophagy was triggered by CoQ0, as shown by LC3-II accumulation, p62/SQSTM1 expression, ATG5 expression, ATG4B inhibition, AVO formation, and impeded Beclin-1/Bcl-2 regulation. In addition, transmission electron microscopy data showed that CoQ0 increased autophagosome formation. The antioxidant N-acetylcysteine substantially suppressed CoQ0-mediated ROS generation and attenuated apoptotic- and autophagic-cell death by CoQ0 in TNBC cells. CoQ0 is a potential anticancer agent in treating human triple-negative breast cancers.

Biogenic Synthesis of High-Performance α-MoO3 Nanoparticles from Tryptophan Derivatives for Antimicrobial Agents and Electrode Materials of Supercapacitors

Molybdenum trioxide nanoparticles (MoO3 NPs) are recognized for their applications in novel multifunctional devices. Here, a biogenic, environmentally friendly method using Lepidagathis cristata leaf extract was employed to synthesize MoO3 NPs. The as-obtained MoO3 NPs exhibited a predominant (0 k0) orientation, representing an α-MoO3 structure. The absorption band at 984 cm-1 observed in the Fourier-transform infrared spectrum corresponded to the terminal Mo = O bond, thereby confirming that the prepared MoO3 NPs were in the orthorhombic phase. Scanning and transmission electron microscopy data revealed that the MoO3 NPs were well crystallized and uniformly distributed with grain sizes in the 70-100 nm range. The biogenic MoO3 NPs demonstrated an excellent zone of inhibition against the selected Gram -ve and Gram +ve bacterial strains, thus providing an alternative to standard antibacterial agents. During electrochemical experiments conducted in a 1 M aqueous Na2SO4 solution, cyclic voltammetry (CV) curves of the MoO3 NPs showed a pseudocapacitive nature, with a high discharge specific capacitance of 294 F/g and good cyclability. These results suggest the feasibility of the proposed biogenic, environmentally friendly method for preparing MoO3 NPs for application in multifunctional devices.

Investigating ultrastructural morphology in MIRAGE syndrome (SAMD9)-derived fibroblasts using transmission electron microscopy.

Background: Heterozygous de novo variants in the gene SAMD9 cause the complex multisystem disorder, MIRAGE syndrome. Patients are characterised by myelodysplasia, infections, growth restriction, adrenal insufficiency, gonadal dysfunction and enteropathies. Pathogenic variants in SAMD9 are gain-of-function and enhance its role as a growth repressor, leading to growth restriction of many tissues. Two studies have reported changes in skin fibroblasts derived from MIRAGE patients, more specifically identifying enlarged endosomes. We have also previously shown subtle changes in endosome size in patients’ fibroblasts compared to controls. However, these variations in endosomes were not as marked as those described in the literature. Methods: We have performed an observational study using transmission electron microscopy (EM) in a larger number of cells derived from three patients’ fibroblasts to assess ultrastructure morphology compared to control images. Results: Consistent changes were observed in cell organelles in all patient samples. In particular, increased endosomal activity was detected, characterised by augmented pinocytosis and vesicle budding, increased endosome number, as well as by large lysosomes and endosomes. Endoplasmic reticulum was also prominent. Mitochondria appeared enlarged in selected cells, possibly due to cellular stress. Cell nuclei did not display major differences compared to controls. Conclusions: EM is a powerful tool to investigate morphological features of tissues and cell organelles, although EM data could be affected by sample preparation methodology, therefore potentially explaining the variability between independent studies, and its analysis can be dependent on the experience of the researcher. The increased endosomal activity we have observed in patients’ fibroblasts could indicate that SAMD9 regulates endocytosis of receptors, acting as an endosome fusion facilitator, or in lysosomal activation. However, the precise mechanism(s) by which SAMD9 regulates cell growth is still not fully understood, and further studies are needed to elucidate its pathogenic pathway and develop therapeutic approaches to support patients.