Microscopy Images Research Articles

Novel method of image analysis that combines Radon and Fourier image transformations for the purpose of differentiating between malignant and benign colonic biopsies.

Colorectal cancer is the third most common type of cancer. It develops slowly as a polyp that can turn into a cancerous tumor. This study aimed to develop a decision-making algorithm of microscopic images using texture analysis that is orientation free, to be used for automated classification of normal and neoplastic (malignant or premalignant) colonic biopsies. Forty-nine colonic adenocarcinomas, 41 adenomas and a control group of adjacent normal colonic mucosa were included in the texture analysis. Radon transform followed by the Fast Fourier transform were applied to the images. Subsequently, the gray level co-occurrence matrix (GLCM) transform was applied allowing the extraction of four textural variables (homogeneity, contrast, correlation, and entropy). For classification and prediction of the diagnosis, a statistical multivariate regression model and a neural network (NNET) model were used and compared. The statistical model provided a sensitivity of 71.3% and a specificity of 50% (Area under the ROC curve: 0.67) for classifying the neoplastic and the normal images, respectively. The NNET model was superior to the statistical model and produced a sensitivity of 97.9% and specificity of 88% (Area under the ROC curve: 0.92). To our knowledge, this is the first study that used a combination of Radon, FFT, and GLCM transformations in order to overcome the tissue orientation problem in texture analysis of microscopic images of colonic biopsies. The NNET classifier trained by the extracted textural features proved to be superior to the statistical classifier, thus predicting colonic neoplasia with high accuracy. RESEARCH HIGHLIGHTS: We propose a novel decision-making algorithm of orientation invariant image texture analysis, fast and easily implemented for automated differentiation between benign and neoplastic epithelial tumors of the colon. This method can reduce the turnaround time allowing to prioritize the biopsies during their examination and diagnosis by the pathologist.

Investigation the effect of surface treatment on the mechanical properties of coating

AbstractThe study analyzed surface treatment's impact on mechanical properties of Fe-based amorphous coatings. Specimens underwent six-hour treatments at 670 and 770 °C using vacuum heat. Results revealed distinct mechanical features in the coating: Vickers hardness reached 755, scanning electron microscope images displayed glassy phases, showcasing good wear resistance and compressive residual stresses at around −55 MPa. A remarkable 122% increase in compressive residual stress was noted through combined vacuum heat treatment and sandblasting. Volume wear decreased from the initial 18 to 14 mm3 after treatment at 670 °C followed by sandblasting, indicating a 30% enhancement in wear resistance. Yet, using vacuum heat treatment at 770 °C negatively impacted the coating's properties.

Reprogramming Filamentous fd Viruses to Capture Copper Ions.

C-terminal truncated variants (A, VA, NVA, ANVA, FANVA and GFANVA) of our recently identified Cu(II) specific peptide "HGFANVA" were displayed on filamentous fd phages. Wild type fd-tet and engineered virus variants were treated with 100 mM Cu(II) solution at a final phage concentration of 1011 vir/ml and 1012 vir/ml. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) imaging before Cu(II) exposure showed ≈6-8 nm thick filamentous virus layer formation. Cu(II) treatment resulted in aggregated bundle-like assemblies with mineral deposition. HGFANVA phage formed aggregates with an excessive mineral coverage. As the virus concentration was 10-fold decreased, nanowire-like assemblies were observed for shorter peptide variants A, NVA and ANVA. Wild type fd phages did not show any mineral formation. Energy dispersive X-ray spectroscopy (EDX) analyses revealed the presence of C and N peaks on phage organic material. Cu peak was only detected for engineered viruses. Metal ion binding of viruses was next investigated by enzyme-linked immunosorbent assay (ELISA) analyses. Engineered viruses were able to bind Cu(II) forming mineralized intertwined structures although no His (H) unit was displayed. Such genetically reprogrammed virus based biological materials can be further applied for bioremediation studies to achieve a circular economy.

Efficacy of sutureless intrascleral intraocular lens fixation with the modified Yamane technique

Objective: To evaluate the efficacy of sutureless intrascleral intraocular lens (IOL) fixation with the modified Yamane technique. Methods: It was a retrospective case series study. Patients undergoing sutureless intrascleral IOL fixation with the modified Yamane technique were included at Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University from January 2022 to September 2023. Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), recorded as the logarithm of the minimum angle of resolution (logMAR), were measured before surgery and at 1 day, 3 days, 1 week, 1 month, and 3 months postoperatively. Refractive error and intraocular pressure were also checked. Anterior segment examination with a slit lamp microscope, fundus examination, anterior segment and posterior segment optical coherence tomography were performed. Intraoperative and postoperative ocular complications were documented. Results: A total of 53 patients (53 eyes) were included in this study, comprising 40 males and 13 females, with a median age of 60 (49, 68) years. Among them, the proportion of a history of trauma was 22.6% (12/53). There was 1 eye with intraoperative vitreous hemorrhage (1.9%). All eyes had no obvious hypotony, no obvious inflammation in the anterior chamber, and no pupillary abnormalities at 1 week after surgery. The mean follow-up time was (8.0±3.3) months (range, 3 to 16 months). There was no iris capture, re-dislocation, or haptic exposure of the IOL during the follow-up. The corneal endothelial cell density was (2 236±704) cells/mm2 preoperatively and (1 964±628) cells/mm2 at 1 month, with significant difference (P<0.001). The UCVA (logMAR) was 1.53±0.75 preoperatively, 0.18±0.17 at 1 month, 0.15±0.14 at 3 months, and 0.14±0.13 at the final visit (P<0.001). The UCVA (logMAR) at 1 month was significantly different from that at 3 months and the final visit (both P<0.05). At 1 month, 50.9% (27/53) of the eyes had an UCVA (logMAR)≤0.1, and the rate was 56.6% (30/53) at 3 months. The BCVA (logMAR) was 0.25±0.21, 0.03±0.06, 0.02±0.06, and 0.02±0.06 before surgery, at postoperative1 month, 3 months, and the final visit, respectively (P<0.001). The BCVA (logMAR) at 1 month was not significantly different from that at 3 months and the final visit (both P>0.05). The rate of the eyes with a BCVA (logMAR)≤0 was 81.1% (43/53) at 1 month and 83.0% (44/53) at 3 months. The IOL tilt was (5.18±2.60)° at postoperative 1 month and (5.08±2.48)° at postoperative 3 months, without statistically significant difference (P>0.05). The IOL decentration was (0.35±0.24) mm at postoperative 1 month and (0.32±0.24) mm at postoperative 3 months, without statistically significant difference (P>0.05). Conclusion: Sutureless intrascleral IOL fixation with the modified Yamane technique is simpler and more minimally invasive to achieve a stable and centered IOL implantation with fewer complications and good visual prognosis.

Design of Polymeric Nanoparticles for Theranostic Delivery of Capsaicin as Anti-Cancer Drug and Fluorescent Nitrogen-Doped Graphene Quantum Dots.

In recent years, multifunctional nanocarriers that provide simultaneous drug delivery and imaging have attracted enormous attention, especially in cancer treatment. In this research, we designed a biocompatible fluorescent multifunctional nanocarrier for the co-delivery of capsaicin (CPS) and nitrogen-doped graphene quantum dots (N-GQDs) using the pH sensitive amphiphilic block copolymer (poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone), PEtOx-b-PCL). The effects of the critical formulation parameters (the amount of copolymer, the concentration of poly(vinyl alcohol) (PVA) as a stabilizing agent in the inner aqueous phase, and volume of the inner phase) were evaluated to achieve optimal nanoparticle properties using Central Composite Design (CCD). The optimized nanoparticles demonstrated a desirable size distribution (167.8±1.4nm) with a negative surface charge (-19.9±0.4) and a suitable loading capacity for capsaicin (70.80±0.05%). The CPS & N-GQD NPs were found to have remarkable toxicity on human breast adenocarcinoma cell line (MCF-7). The solid fluorescent signal was acquired from cells containing multifunctional nanoparticles, according to the confocal microscope imaging results, confirming the significant cellular uptake. This research illustrates the enormous potential for cellular imaging and enhanced cancer therapy offered by multifunctional nanocarriers that combine drug substances with the novel fluorescent agents. This article is protected by copyright. All rights reserved.

Restoring the quality of electron microscope images through environmental monitoring

Restoring the quality of electron microscope images through environmental monitoring

Topical gel formulations as potential dermal delivery carriers for green-synthesized zinc oxide nanoparticles.

This study aimed to incorporate green-synthesized zinc oxide nanoparticles (ZnO NPs), functionalized with polyethylene glycol (PEG) and linked to doxorubicin (DOX), into various topical gel formulations (hydrogel, oleogel, and bigel) to enhance their dermal delivery. The ZnO NPs were produced using the aqueous extract of the root hair of Phoenix dactylifera. The optimized green-synthesized ZnO NPs, PEGylated and conjugated to DOX, demonstrated a particle size below 100nm, low polydispersity index, and zeta potential between - 11 and - 19 mV. The UV-Vis spectroscopy analysis confirmed characteristic absorption peaks at 351 and 545nm for ZnO and DOX, respectively. The transmission electron microscope (TEM) images revealed well-dispersed spherical nanoparticles without aggregation. Additionally, ZnO NPs-loaded gels exhibited uniformity, cohesion, no phase separation, pseudoplastic flow, and viscoelastic properties. The in vitro release studies showed that DOX-PEG-ZnO NPs hydrogel released 99.5% of DOX after 5h of starting the release. Moreover, the penetration of DOX-PEG-ZnO NPs through excised rat skin was visualized by TEM. In conclusion, the hydrogel formulation containing green-synthesized DOX-PEG-ZnO NPs holds great promise for dermal administration in skin cancer treatment. Furthermore, the release rate and skin penetration of DOX from gels were varied based on the type of gel matrix and corroborated with their corresponding rheological properties.

High χ P2PFBEMA-b-P2VP Block Copolymers Forming 6-8 nm Domains for Semiconductor Lithography.

We leveraged the potential of high χ-low N block copolymer (BCP), namely, poly[2-(perfluorobutyl) ethyl methacrylate]-block-poly(2-vinylpyridine) (P2PFBEMA-b-P2VP), and demonstrated its utility in next-generation nanomanufacturing. By combining molecular dynamics simulations with experiments, the χ value was calculated to be as high as 0.4 (at 150 °C), surpassing similar structures. Highly ordered features suitable for application were observed, ranging in periods from 19.0 nm down to 12.1 nm, with feature sizes as small as 6 nm. Transmission electron microscopy images of the BCP solutions indicated that preformed micelles in the solution facilitated the self-assembly process of the thin film. In addition, the vertical or parallel orientation of the cylindrical structure was determined by manipulating the solvent, substrate, and annealing conditions. Finally, guided by a wide topographical template, nearly defect-free directed self-assembly (DSA) lines with a resolution of 8 nm were achieved, highlighting its potential practical application in DSA lithography technology.

Stereo reconstruction from microscopic images for computer-assisted ophthalmic surgery.

This work presents a novel platform for stereo reconstruction in anterior segment ophthalmic surgery to enable enhanced scene understanding, especially depth perception, for advanced computer-assisted eye surgery by effectively addressing the lack of texture and corneal distortions artifacts in the surgical scene. The proposed platform for stereo reconstruction uses a two-step approach: generating a sparse 3D point cloud from microscopic images, deriving a dense 3D representation by fitting surfaces onto the point cloud, and considering geometrical priors of the eye anatomy. We incorporate a pre-processing step to rectify distortion artifacts induced by the cornea's high refractive power, achieved by aligning a 3D phenotypical cornea geometry model to the images and computing a distortion map using ray tracing. The accuracy of 3D reconstruction is evaluated on stereo microscopic images of ex vivo porcine eyes, rigid phantom eyes, and synthetic photo-realistic images. The results demonstrate the potential of the proposed platform to enhance scene understanding via an accurate 3D representation of the eye and enable the estimation of instrument to layer distances in porcine eyes with a mean average error of 190 , comparable to the scale of surgeons' hand tremor. This work marks a significant advancement in stereo reconstruction for ophthalmic surgery by addressing corneal distortions, a previously often overlooked aspect in such surgical scenarios. This could improve surgical outcomes by allowing for intra-operative computer assistance, e.g., in the form of virtual distance sensors.

Simulated Swine Digestion and Gut Microbiota Fermentation of Hydrolyzed Copra Meal.

This study aimed to compare the effects of hydrolyzed copra meal (HCM) inclusion at 1% on its in vitro digestibility and the microbiota and cecum fermentation using the gut microbiota of weaned swine, targeting microbial community and short-chain fatty acids (SCF). For this reason, three treatments were considered: control (no copra meal), 1% non-hydrolyzed copra meal (CM), and 1% HCM. Non-defatted copra meal was hydrolyzed and analyzed (reducing sugars and total carbohydrates) in our laboratory. For digestion, microbiota identification, and fermentation assays, fresh fecal samples from two weaned pigs (1 month old) were used. Three replicates of each treatment were employed. HCM was more digestible, with approximately 0.68 g of hydrolysate recovered after simulated digestion compared to 0.82 g of hydrolysate recovered from CM. This was shown by Scanning Electron Microscope (SEM) images. Also, the three swine shared the majority of microbial species identified at the phylum and family levels. There were no differences (p > 0.05) between treatments in the microbial community and SCFA during fermentation. However, higher Chao-1 and Shannon indexes were observed in CM and HCM treatments. HCM was also found to be capable of preserving Actinobacterota and Proteobacteria at the phylum level, while at the family level, both treatments may help Lactobacillaceae, Peptostreptococcaceae, Lachnospiraceae, and Ruminococcaceae survive in the long term. Also, there was a potential trend of increasing acetic acid and butyric acid in the CM and HCM treatments. While HCM shows promise in potentially modulating the gut microbiota of weaned swine, additional research is required to investigate the effects of higher doses of HCM on swine performance parameters.

Statistical analysis of aging micro-characteristics for asphalt binder AFM images based on neural network classification

To further evaluate the effect of aging behavior on microstructure for asphalt binder, the atomic force microscope (AFM) images of asphalt binder were studied by neural network classification technology, and its aging micro-characteristics were analyzed statistically. Firstly, AFM equipment was used to test 90# virgin asphalt binder and styrene–butadiene–styrene (SBS) modified asphalt binder commonly used in engineering, and the typical micromorphology AFM images of asphalt binders were obtained. Subsequently, the asphalt binder AFM images were preliminatively analyzed, and the micro-characteristics of AFM images before and after aging were compared, including the “bee structure” characteristics, distribution law and surface structure roughness. Finally, the asphalt binder AFM images were further analyzed by neural network classification, and the change of “bee structure” was statistically calculated and analyzed, and its aging micro-characteristics were quantitatively evaluated. The results show that it is feasible for neural network classification to be applied to the statistical analysis of asphalt binder AFM images, and it can further describe and evaluate the aging micro-characteristics of asphalt binder. Aging behavior reduces the proportion of intermediate category areas in asphalt binder AFM images and increases the “bee structure” areas. The cumulative percentage curve of asphalt binder AFM images is smoother (each category is more uniform), indicating that the asphalt binder performance tended to be stable after aging. The results further enrich the description of asphalt binder AFM images, and provide a new way to explore the micro-morphology of asphalt binder.

One-pot approach biosynthesis of nisin-conjugated zinc oxide nanoparticles using Bacillus subtilis ZBP4 with improved antibacterial activity

AbstractBiosynthesis of nisin-conjugated zinc oxide nanoparticles (N-ZnONPs) using the supernatant of Bacillus subtilis ZBP4 was demonstrated using a single-step reaction. Various amounts of nisin (5, 10, 15 mg/mL) and 8 mM ZnSO4.7H2O were reacted in the cell-free supernatant of Bacillus subtilis ZBP4 at 33 °C for 48 h. Surface plasmon resonance peaks created by N-ZnONPs were measured at 341–342 nm with a UV-VIS spectrophotometer, and the band-gap energy was calculated as 3.38 eV, indicating the nano-conjugates acted as semiconductors. Transmission electron microscopy (TEM) images showed that the N-ZnONPs were pseudo-spherical with an average diameter of 23 nm. Fourier transform infrared (FTIR) spectra analysis confirmed the presence of nisin as well as other organic substances in the structure. N-ZnONPs had potent antimicrobial activity on Escherichia coli O157:H7 and Staphylococcus aureus; the minimum inhibition concentrations were 0.05 and 1 mg/mL, respectively. In addition, conjugation with nisin increased the long-term stability of nanoparticles when compared to unconjugated ZnONPs.

Enhancement of antifouling and mechanical properties of polysulfone membrane using zwitterionic biphenyl polyimide as additive

Biphenyl polyimides, which are known by its excellent heat resistance and mechanical properties, were synthesized by adjusting the molar ratio of monomers, followed by end-functionalized with zwitterionic group via reaction with 1,3-propanesultone. The zwitterionic sulfobetaine biphenyl polyimide (z-biph-PI) copolymers with different hydrophobic chain lengths were employed as the additive for the preparation of polysulfone (PSf) membrane. X-ray photoelectron spectrometry (XPS) measurement on membrane surfaces revealed that the sulfobetaine groups of z-biph-PI migrated toward water in the membrane formation process, during which a large amount of porous, narrow and densely packed pores were created as illustrated in scanning electron microscopy (SEM) images. Therefore, the incorporation of z-biph-PI simultaneously enhanced the pure water flux and protein rejection ratio of membranes, overcoming the trade-off effects between permeability and selectivity. The adsorption of bovine serum albumin decreased from ∼47.7 μg/cm2 for the pristine membrane to a minimum of ∼12.4 μg/cm2 for the blend membrane. More importantly, the tensile strength and elongation at break were also simultaneously improved due to the unique mechanical property of biph-PI and the strong π-π interaction between biphe-PI and PSf. Meanwhile, the blend membrane exhibited excellent filtration and thermal stability. All these characteristics of the blend membrane made it promising in ultrafiltration application.

Precision engineering of nano-assemblies in superfluid helium by the use of van der Waals forces

The ability to precisely engineer nanostructures underpins a wide range of applications in areas such as electronics, optics, and biomedical sciences. Here we present a novel approach for the growth of nanoparticle assemblies that leverages the unique properties of superfluid helium. Unlike viscous solvents at or near room temperature, superfluid helium provides an unperturbed and cold environment in which weak van der Waals interactions between molecular templates and metal atoms become significant and can define the spatial arrangement of nanoparticles. To demonstrate this concept, diol and porphyrin-based molecules are employed as templates to grow gold nanoparticle assemblies in superfluid helium droplets. After soft-landing on a solid surface to remove the helium, transmission electron microscopy (TEM) imaging shows the growth of gold nanoparticles at specific binding sites within the molecular templates where the interaction between gold atoms and the molecular template is at its strongest.

Noninvasive platelet membrane‐coated Fe3O4 nanoparticles identify vulnerable atherosclerotic plaques

AbstractVulnerable atherosclerotic plaques serve as the primary pathological basis for fatal cardiovascular and cerebrovascular diseases. The precise identification and treatment of these vulnerable plaques hold paramount clinical importance in mitigating the incidence of myocardial infarction and stroke. Nevertheless, the identification of vulnerable plaques within the diffuse atherosclerotic plaques dispersed throughout the systemic circulation continues to pose a substantial challenge in clinical practice. Double emulsion solvent evaporation method, specifically the water‐in‐oil‐in‐water (W/O/W) technique, was employed to fabricate Fe3O4‐based poly (lactic‐co‐glycolic acid) (PLGA) nanoparticles (Fe3O4@PLGA). Platelet membranes (PM) were extracted through hypotonic lysis, followed by ultrasound‐assisted encapsulation onto the surface of Fe3O4@PLGA, resulting in the formation of PM‐coated Fe3O4 nanoparticles (PM/Fe3O4@PLGA). Characterization of PM/Fe3O4@PLGA involved the use of dynamic light scattering, transmission electron microscopy, western blotting, and magnetic resonance imaging (MRI). A model of atherosclerotic vulnerable plaques was constructed by carotid artery coarctation and a high‐fat diet fed to ApoE−/− (Apolipoprotein E knockout) mice. Immunofluorescence and MRI techniques were employed to verify the functionality of PM/Fe3O4@PLGA. In this study, we initially synthesized Fe3O4@PLGA as the core material. Subsequently, a platelet membrane was employed as a coating for the Fe3O4@PLGA, aiming to enable the detection of vulnerable atherosclerotic plaques through MRI. In vitro, PM/Fe3O4@PLGA not only exhibited excellent biosafety but also showed targeted collagen characteristics and MR imaging performance. In vivo, the adhesion of PM/Fe3O4@PLGA to atherosclerotic lesions was confirmed in a mouse model of vulnerable atherosclerotic plaques. Simultaneously, PM/Fe3O4@PLGA as a novel contrast agent for MRI has shown effective identification of vulnerable atherosclerotic plaques. In terms of safety profile in vivo, PM/Fe3O4@PLGA has not demonstrated significant organ toxicity or inflammatory response in the bloodstream. In this study, we successfully developed a platelet‐membrane‐coated nanoparticle system for the targeted delivery of Fe3O4@PLGA to vulnerable atherosclerotic plaques. This innovative system allows for the visualization of vulnerable plaques using MRI, thereby demonstrating its potential for enhancing the clinical diagnosis of vulnerable atherosclerotic plaques.

Major Imaging Challenges in Microscopy and How to Solve Them

Abstract Imaging artifacts often hinder the accuracy of microscopy images, affecting sample analyses and their interpretations. In this article, we explore five prominent imaging artifacts that commonly plague microscopy: blooming/saturation, pixelation, temporal/time varying noise, phototoxicity/photobleaching, and compression. Effective mitigation of these imaging artifacts hinges on careful consideration of key camera parameters, including quantum efficiency, bit-depth, resolution, and dynamic range, each crucial for optimizing image quality and fidelity. A wide range of camera solutions offered by e-con Systems provides consistent support to the various types of microscopy techniques from fluorescence microscopy to live cell imaging.

A suite of genome-engineered hepatic cells provide novel insights into the spatiotemporal metabolism of APOB and APOB-containing lipoprotein secretion.

APOB-containing very-low-density lipoprotein (VLDL) production, secretion, and clearance by hepatocytes is a central determinant of hepatic and circulating lipid levels. Impairment of any of the aforementioned processes is associated with the development of multiple diseases. Despite the discovery of genes and processes that govern hepatic VLDL metabolism, our understanding of the different mechanistic steps involved is far from complete. An impediment to these studies is the lack of tractable hepatocyte-based systems to interrogate and follow APOB in cells, which the current study addresses. To facilitate the cellular study of VLDL metabolism, we generated human hepatic HepG2 and Huh-7 cell lines in which CRISPR/Cas9-based genome engineering was used to introduce the fluorescent protein mNeonGreen into the APOB gene locus. This results in the production of APOB100-mNeon that localizes predominantly to the endoplasmic reticulum (ER) and Golgi by immunofluorescence and electron microscopy imaging. The production and secretion of APOB100-mNeon can be quantitatively followed in medium over time, and results in production of lipoproteins that are taken up via the LDLR pathway. Importantly, the production and secretion of APOB-mNeon is sensitive to established pharmacological and physiological treatments, and to genetic modifiers known to influence VLDL production in humans. As a showcase, we used HepG2-APOBmNeon cells to interrogate ER-associated degradation (ERAD) of APOB. Using a dedicated sgRNA library targeting all established membrane-associated ER-resident E3 ubiquitin ligases led to identification of SYNV1 as the E3 responsible for degradation of poorly-lipidated APOB in HepG2 cells. In summary, the engineered cells reported here allow the study of hepatic VLDL assembly and secretion, and facilitate spatiotemporal interrogation induced by pharmacologic and genetic perturbations.

Antifungal and antibiofilm effects of probiotic Lactobacillus salivarius, zinc nanoparticles, and zinc nanocomposites against Candida albicans from Nile tilapia (Oreochromis niloticus), water and humans.

Candida albicans (C. albicans) can form biofilms; a critical virulence factor that provides effective protection from commercial antifungals and contributes to public health issues. The development of new antifungal therapies, particularly those targeting biofilms, is imperative. Thus, this study was conducted to investigate the antifungal and antibiofilm effects of Lactobacillus salivarius (L. salivarius), zinc nanoparticles (ZnNPs) and nanocomposites (ZnNCs) on C. albicans isolates from Nile tilapia, fish wash water and human fish sellers in Sharkia Governorate, Egypt. A cross-sectional study collected 300 samples from tilapia, fish wash water, and fish sellers (100 each). Probiotic L. salivarius was immobilized with ZnNPs to synthesize ZnNCs. The study assessed the antifungal and antibiofilm activities of ZnNPs, L. salivarius, and ZnNCs compared to amphotericin (AMB). Candida spp. were detected in 38 samples, which included C. albicans (42.1%), C. glabrata (26.3%), C. krusei (21.1%), and C. parapsilosis (10.5%). A total of 62.5% of the isolates were resistant to at least one antifungal agent, with the highest resistance to nystatin (62.5%). However, 75% of the isolates were highly susceptible to AMB. All C. albicans isolates exhibited biofilm-forming capabilities, with 4 (25%) isolates showing strong biofilm formation. At least one virulence-associated gene (RAS1, HWP1, ALS3, or SAP4) was identified among the C. albicans isolates. Probiotics L. salivarius, ZnNPs, and ZnNCs displayed antibiofilm and antifungal effects against C. albicans, with ZnNCs showing significantly higher inhibitory activity. ZnNCs, with a minimum inhibitory concentration (MIC) of 10 µg/mL, completely reduced C. albicans biofilm gene expression. Additionally, scanning electron microscopy images of C. albicans biofilms treated with ZnNCs revealed asymmetric, wrinkled surfaces, cell deformations, and reduced cell numbers. This study identified virulent, resistant C. albicans isolates with strong biofilm-forming abilities in tilapia, water, and humans, that pose significant risks to public health and food safety.

Microencapsulation of phase change materials (PCMs) at low temperature using a novel thin film UV reactor

Phase-change materials (PCMs) have shown great promise for energy management in buildings and gained attention in the field of sustainable and energy-efficient construction. However, to fully utilize PCMs, their proper containment is vital. In this study, a photo-induced polymerization process using a new thin film UV reactor at room temperature for PCM microencapsulation in polymer shells of different acrylate-based monomers was investigated. Four different acrylate-based monomers were investigated: namely, methyl methacrylate (MMA), ethyl acrylate (EAA), butyl acrylate (BAA), and tert-butyl acrylate (TBMA). Commercial Rubitherm’s RT21 PCM (Tpeak,melting ∼ 21 °C and ΔH = 123 kJ/kg) and Irgacure® 819 as a photosensitive initiator were used. When MMA or EAA were used, scanning electron microscopy (SEM) images revealed smooth surfaces of PCM microcapsules (m-PCMs) with a hemispherical shape. While m-PCMs with rough surfaces, buckles, and dimples were found when BAA and TBMA were applied. The results showed that the highest levels of microencapsulation efficiency, yield, and PCM content were observed for MMA and EAA samples. The TBMA sample shows low values of microencapsulation efficiency and yield (about 29.1 and 53.4 %, respectively). Furthermore, results showed that adding cross-linking agents to the recipe has had multiple favourable effects. It has mitigated sub-cooling, increased PCM content, improved microencapsulation efficiency, and boosted the overall yield of PCM. In conclusion, the current work will contribute to the development of a microencapsulation technology of PCMs that overcomes the shortcomings of long time and high temperature needed in the present traditional microencapsulation procedure.

Vacancy Ordering in Ultrathin Copper Oxide Films on Cu(111).

Oxide thin films grown on metal surfaces have wide applications in catalysis and beyond owing to their unique surface structures compared to their bulk counterparts. Despite extensive studies, the atomic structures of copper surface oxides on Cu(111), commonly referred to as "44" and "29", have remained elusive. In this work, we demonstrated an approach for the structural determination of oxide surfaces using element-specific scanning tunneling microscopy (STM) imaging enhanced by functionalized tips. This approach enabled us to resolve the atomic structures of "44" and "29" surface oxides, which were further corroborated by noncontact atomic force microscopy (nc-AFM) measurements and Monte Carlo (MC) simulations. The stoichiometry of the "44" and "29" frameworks was identified as Cu23O16 and Cu16O11, respectively. Contrary to the conventional hypothesis, we observed ordered Cu vacancies within the "44" structure manifesting as peanut-shaped cavities in the hexagonal lattice. Similarly, a combination of Cu and O vacancies within the "29" structure leads to bean-shaped cavities within the pentagonal lattice. Our study has thus resolved the decades-long controversy on the atomic structures of "44" and "29" surface oxides, advancing our understanding of copper oxidation processes and introducing a robust framework for the analysis of complex oxide surfaces.