Effects of Leydig cell elimination on testicular interstitial cell populations: characterization by scRNA-seq and immunocytochemical techniques.

Background: The mammalian testicular interstitial cells are not well-defined. The present study characterized the interstitial cell types and their turnover dynamics in adult rats. Additionally, the heterogeneity of the mesenchymal population and the effects of Leydig cell elimination on interstitial homeostasis were further analyzed by scRNA-seq datasets and immunocytochemical techniques. Methods: Interstitial cells were defined at the transcriptomic level by scRNA-seq and then confirmed and quantified with protein markers. The dividing activity of the major cell types was determined by continuous EdU labeling of the animals for one week. Some of the rats were also treated with a dose of ethylenedimethylsulfonate (EDS) to examine how the loss of Leydig cells (LCs) could affect interstitial homeostasis for three weeks. Results: Seven interstitial cell types were identified, including cell types (percentage of the whole interstitial population) as follows: Leydig (44.6%), macrophage and dendritic (19.1%), lymphoid (6.2%), vascular endothelial (7.9%), smooth muscle (10.7%), and mesenchymal (11.5%) cells. The EdU experiment indicated that most cell types were dividing at relatively low levels (<9%) except for the mesenchymal cells (MCs, 17.1%). Further analysis of the transcriptome of MCs revealed 4 subgroups with distinct functions, including 1) glutathione metabolism and xenobiotic detoxification, 2) ROS response and AP-1 signaling, 3) extracellular matrix synthesis and binding, and 4) immune response and regulation. Stem LCs (SLCs) are primarily associated with subgroup 3, expressing ARG1 and GAP43. EDS treatment not only eliminated LCs but also increased subgroup 3 and decreased subgroups 1 and 2 of the mesenchymal population. Moreover, EDS treatment increased the division of immune cells by more than tenfold in one week. Conclusion: Seven interstitial cell types were identified and quantified for rat testis. Many may play more diversified roles than previously realized. The elimination of LCs led to significant changes in MCs and immune cells, indicating the importance of LCs in maintaining testicular interstitial homeostasis.

In-depth analysis of isochorismate synthase-derived metabolism in plant immunity: identification of meta-substituted benzoates and salicyloyl-malate.

Isochorismate-derived metabolism enables biosynthesis of the plant defence hormone salicylic acid (SA) and its derivatives. In Arabidopsis thaliana, the stress-induced accumulation of SA depends on ISOCHORISMATE SYNTHASE1 (ICS1), and also requires the presumed isochorismate transporter ENHANCED DISEASE SUSCEPTIBILITY5 (EDS5) and the GH3 enzyme avrPphB SUSCEPTIBLE3 (PBS3). By comparative metabolite and structural analyses, we identified several hitherto unreported ICS1- and EDS5-dependent, biotic stress-inducible Arabidopsis metabolites. These involve meta-substituted SA derivatives (5-formyl-SA, 5-carboxy-SA, 5-carboxymethyl-SA), their benzoic acid (BA) analogues (3-formyl-BA, 3-carboxy-BA, 3-carboxymethyl-BA) and, besides the previously detected salicyloyl-aspartate (SA-Asp), the ester conjugate salicyloyl-malate (SA-Mal). SA functions as a biosynthetic precursor for SA-Mal and SA-Asp, but not for the meta-substituted SA- and BA-derivatives, which accumulate to moderate levels at later stages of bacterial infection. Interestingly, Arabidopsis leaves possess oxidising activity to effectively convert meta-formyl- into meta-carboxy-SA/BAs. In contrast to SA, exogenously applied meta-substituted SA/BA-derivatives and SA-Mal exert moderate impact on plant immunity and defence-related gene expression. While the isochorismate-derived metabolites are negatively regulated by the SA receptor NON-EXPRESSOR OF PR GENES1, SA conjugates (SA-Mal, SA-Asp, SA-glucose conjugates) and meta-substituted SA/BA-derivatives are oppositely affected by PBS3. Notably, our data indicate a PBS3-independent path to isochorismate-derived SA at later stages of bacterial infection, which does not considerably impact immune-related characteristics. Moreover, our results argue against a previously proposed role of EDS5 in the biosynthesis of the immune signal N-hydroxypipecolic acid and associated transport processes. We propose a significantly extended biochemical scheme of plant isochorismate metabolism that involves an alternative generation mode for benzoate- and salicylate-derivatives.

Sleep disorders and Parkinson's disease: is there a right direction?

In the last years, the hypothesis of a close relationship between sleep disorders (SDs) and Parkinson's disease (PD) has significantly strengthened. Whether this association is causal has been also highlighted by recent evidence demonstrating a neurobiological link between SDs and PD. Thus, the question is not whether these two chronic conditions are mutually connected, but rather how and when this relationship is expressed. Supporting this, not all SDs manifest with the same temporal sequence in PD patients. Indeed, SDs can precede or occur concomitantly with the onset of the clinical manifestation of PD. This review discusses the existing literature, putting under a magnifying glass the timing of occurrence of SDs in PD-neurodegeneration. Based on this, here, we propose two possible directions for studying the SDs-PD relationship: the first direction, from SDs to PD, considers SDs as potential biomarker/precursor of future PD-neurodegeneration; the second direction, from PD to SDs, considers SDs as concomitant symptoms in manifest PD, mainly related to primary PD-neuropathology and/or parkinsonian drugs. Furthermore, for each direction, we questioned SDs-PD relationship in terms of risk factors, neuronal circuits/mechanisms, and impact on the clinical phenotype and disease progression. Future research is needed to investigate whether targeting sleep may be the winning strategy to treat PD, in the context of a personalized precision medicine.

A SEM/EDS evaluation of debris removal of used rotary Ni-Ti endodontic files by four different cleaning solutions.

Purpose: The aim of this study was to compare the efficacies levels of four cleaning solutions for removing debris from rotary Nickel-Titanium (Ni-Ti) endodontic instruments. Materials and methods: Twelve instruments that fractured during ex vivo instrumentation were used. Fractured surfaces were investigated by SEM before and after 3, 6 and 9 min of ultrasonic cleaning in 17 % EDTA.3NaOH (Group A), 2.5 % NaOCl (Group B), Dentasept 3H Rapide (Group C) and ZymeX™ (Group D) solutions. EDS analyses of selected files from all four groups of untreated and ultrasonically cleaned samples were performed to assess the elemental composition of the alloy surfaces. Results: SEM analysis revealed that after 9 min of ultrasonic agitation, all four investigated solutions had cleaned fractured surfaces. However, some low-atomic-number regions exhibited random distributions on the fractured surfaces. EDS analyses indicated that only C was retained on surface after 9 min of ultrasonic cleaning. This finding was common in all tested groups. Conclusions: All four investigated solutions substantially removed debris from the surfaces of the Ni-Ti files and were considered appropriate for clinical practice.

A kinetic modelling approach to explore mechanism of Cr(VI) detoxification by a novel strain Pseudochrobactrum saccharolyticum NBRI-CRB 13 using response surface methodology.

A novel Pseudochrobactrum saccharolyticum strain NBRI-CRB 13, isolated from tannery sludge, was studied to grow up to 500 mgL-1 of Cr(VI) and showed Cr(VI) detoxification by reducing > 90% of Cr(VI) at different concentrations 25, 50 and 100 mgL-1. Kinetic studies showed that first-order models were fitted (R2 = 0.998) to the time-dependent Cr(VI) reduction with degradation rate constant (k) (1.03-0.429 h-1). Cr(VI) detoxification was primarily related to the extracellular fraction of microbial cells, which showed a maximum extracellular reductase enzyme activity led to 94.6% reduction of Cr(VI). Moreover, the strain showed maximum extracellular polymeric substances (EPS) production at 100 mgL-1 Cr(VI), which is presumably the reason for Cr(VI) removal as EPS serves as the metal binding site for Cr(VI) ions. Further, an optimization study using Box-Behnken design was conducted considering parameters viz., pH, temperature, and initial concentration of Cr(VI). The maximum percent reduction of Cr(VI) was obtained at pH 6.5, temperature 30 °C with 62.5 mgL-1Cr(VI) concentration. Further, the Cr(VI) reduction and adsorption ability of strain P. saccharolyticum NBRI-CRB13 were confirmed by SEM-EDS, FTIR, and XRD analyses. FTIR analysis confirmed the presence of functional groups (-OH, -COOH, -PO4) on bacterial cell walls, which were more likely to interact with positively charged chromium ions. The study elucidated the reduction of Cr(VI) by the novel bacterium within 24 h using the response surface methodology approach and advocated its application in real-time situations.

Microscopic and Color Changes in Direct Dental Restorative Composite Resins upon Immersion in Beverages: Characterization by Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS).

This study aimed to evaluate the staining sensitivity and surface changes in recent composite resins (Herculite Ultra XRV (Kerr, Bolzano, Italy), G-ænial A'CHORD (GC Corp, Tokyo, Japan), and Omnichroma (Yamaguchi, Japan)) when exposed to common beverages such as coffee, red wine, and Coca-Cola. A total of 60 disk-shaped specimens were prepared from three different resin composites (n = 20 each). The specimens were exposed to coffee, red wine, and Coca-Cola for 10 days. Color measurements were taken using a spectrophotometer, and surface morphology and elemental composition were analyzed using SEM and EDS. The SEM and EDS analyses revealed significant changes in the surface morphology and elemental composition of the composites after immersion. Coffee and wine caused significant surface degradation, whereas Coca-Cola resulted in the greatest degree of surface and elemental variations. Color changes (ΔE = 4 ± 0.52) were most notable in Coca-Cola for Herculite Ultra XRV (Kerr, Italy), in red wine for G-ænial A'CHORD (GC Corp, Japan) (ΔE = 12.51 ± 0.38), and in coffee for Omnichroma (Yamaguchi, Japan) (ΔE = 10.85 ± 1.03). The tested beverages significantly affected both the surface condition and the chemical composition of the resin at the surface level. These findings highlight the importance of understanding the effects of common dietary beverages on dental composites.

Synthesis of MnFe2O4 Spinel on Rusted Q235 Steel Surface and Its Corrosion Resistance Properties.

Corrosion of steel is an issue that cannot be ignored in contemporary society. Due to large-scale corrosion, it is urgent to develop a surface treatment process that enhances the corrosion resistance of steel, allowing for application in various scenarios as needed. This study aims to investigate a novel surface treatment process to extend the service life of corroded Q235 steel, reduce its sensitivity to corrosion, and enable its use in multiple environments. This study employs the sol-gel method, using manganese nitrate solutions of varying concentrations to treat the surface of Q235 steel after different electrolysis times. The optimal conditions for precursor preparation were found to be a Mn2+ concentration of 0.1 mol/L and an electrolysis time of 2 h. Electrochemical tests using NaCl solutions of different concentrations revealed a significant reduction in the corrosion current for the composite coating based on Q235 steel treated with this method in NaCl solutions with wt.% = 1, 2, 3, 4, 5. Furthermore, the resistance to corrosion was strongest in the NaCl solution with a concentration of 1 wt.% where the corrosion current decreased from 24.8 µA/cm2 to 6.79 µA/cm2. Additionally, the coating was found to be diffusion-controlled in the early stages of the corrosion process and charge transfer-controlled in the later stages. The MnFe2O4 spinel coating demonstrated the greatest enhancement in corrosion resistance in the wt.% = 1 NaCl solution.

Atomic-Scale Characterization of Dilute Dopants in Topological Insulators via STEM-EDS Using Registration and Cell Averaging Techniques.

Magnetic dopants in three-dimensional topological insulators (TIs) offer a promising avenue for realizing the quantum anomalous Hall effect (QAHE) without the necessity for an external magnetic field. Understanding the relationship between site occupancy of magnetic dopant elements and their effect on macroscopic property is crucial for controlling the QAHE. By combining atomic-scale energy-dispersive X-ray spectroscopy (EDS) maps obtained by aberration-corrected scanning transmission electron microscopy (AC-STEM) and novel data processing methodologies, including semi-automatic lattice averaging and frame registration, we have determined the substitutional sites of Mn atoms within the 1.2% Mn-doped Sb2Te3 crystal. More importantly, the methodology developed in this study extends beyond Mn-doped Sb2Te3 to other quantum materials, traditional semiconductors, and even electron irradiation sensitive materials.

Impact of carbon and platinum protective layers on EDS accuracy in FIB cross-sectional analysis of W/Hf/W thin-film multilayers.

Achieving high-quality cross sections is essential for accurate analysis of multilayer coatings. One method of performing such cross sections is focused ion beam, where sample protection from ion damage in the form of protective layers applied by FEBID and FIBID methods is used. Due to the lack of comparative summaries of different layers applied by these methods, especially in the context of cross-sectional analysis and elemental analysis of the cross-section, it was decided to address the effect of the protective layer on the reliability of EDS analysis. This study compares the effectiveness of platinum and carbon protective layers in creating cross sections for W/Hf/W samples. The effect of protective layers on elemental mapping and elemental analysis accuracy was evaluated. This study highlights the importance of protective layer selection in providing reliable EDS analysis of cross sections.

Characterization of Melt-Spun Recycled PA 6 Polymer by Adding ZnO Nanoparticles during the Extrusion Process.

With recent technological advances and the growing interest in environmentally friendly fiber production processes, the textile industry is increasingly turning to the spinning of filaments from recycled raw materials in the melt spinning process as the simplest method of chemical spinning of fibers. Such processes are more efficient because the desired active particles are melt-spun together with the polymer. The study investigates the melt spinning of recycled polyamide 6 (PA 6) fibers modified with zinc oxide nanoparticles (ZnO NPs) in concentrations ranging from 0.1 to 2.0 wt% of the polymer. The extrusion process was optimized under laboratory conditions. An analysis of the effectiveness of the nanoparticle distribution and chemical composition was performed using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). The results of the thermal analysis show an increase in the glass transition temperature of the extruded material from 50.97 °C (raw polymer) to 51.40 °C to 57.98 °C (polymer modified with ZnO NPs) and an increase in the crystallization point from 148.19 °C to a temperature between 175.61 °C and 178.16 °C, while the molar enthalpy (ΔHm) shows a decreasing trend from 65.66 Jg-1 (raw polymer) to 48.23 Jg-1 (PA 6 2.0% ZnO). The FTIR spectra indicate PA 6 polymer, with a characteristic peak at the wavelength 1466 cm-1, but pure ZnO and PA 6 blended with ZnO show a characteristic peak at 2322 cm-1. The distribution of nanoparticles on the fiber surface is more or less randomly distributed and the different size of NPs is visible. These results are confirmed by the EDS results, which show that different concentrations of Zn are present. The mechanical stability of the extruded polymer modified with NPs is not affected by the addition of ZnO NPs, although the overall results of strength (2.56-3.22 cN/tex) and modulus of elasticity of the polymer (28.83-49.90 cN/tex) are lower as there is no drawing process at this stage of the experiment, which certainly helps to increase the final strength of the fibers. The results indicate the potential of modification with ZnO NPs for further advances in sustainable fiber production.

Automatic summarization model based on clustering algorithm.

Extractive document summary is usually seen as a sequence labeling task, which the summary is formulated by sentences from the original document. However, the selected sentences usually are high redundancy in semantic space, so that the composed summary are high semantic redundancy. To alleviate this problem, we propose a model to reduce the semantic redundancy of summary by introducing the cluster algorithm to select difference sentences in semantic space and we improve the base BERT to score sentences. We evaluate our model and perform significance testing using ROUGE on the CNN/DailyMail datasets compare with six baselines, which include two traditional methods and four state-of-art deep learning model. The results validate the effectiveness of our approach, which leverages K-means algorithm to produce more accurate and less repeat sentences in semantic summaries.

Prevalence of nano-sized coal mine dust in North and Central Appalachian coal mines - Insights from SEM-EDS imaging.

The increasing prevalence of coal mine dust-related lung diseases in coal miners calls for urgent and meticulous scrutiny of airborne respirable coal mine dust (RCMD), specifically focusing on particles at the nano-level. This necessity is driven by expanding research, including the insights revealed in this paper, that establish the presence and significantly increased toxicity of nano-sized coal dust particles in contrast to their larger counterparts. This study presents an incontrovertible visual proof of these tiny particulates in samples collected from underground mines, utilizing advanced techniques such as scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The intricate elemental composition of nano-sized coal dust identified through EDS analysis reveals the presence of elements such as silica and iron, which are known to contribute to lung pathologies when inhaled over prolonged periods. The outcomes of the statistical analyses reveal significant relationships between particle size and elemental composition, highlighting that smaller particles tend to have higher carbon content, while larger particles exhibit increased concentrations of elements like silica and aluminum. These analyses underscore the complex interactions within nano-sized coal dust, providing critical insights into their behavior, transport, and health impacts. The nano-sized coal dust could invade the alveoli, carrying these toxic elements from where they are impossible to exhale. The revelation of nano-sized coal dust's existence and the associated health hazards necessitate their incorporation into the regulatory framework governing the coal mining industry. This study lays the groundwork for heightened protective measures for miners, urging the invention of state-of-the-art sampling instruments, comprehensive physicochemical profiling of RCMD nanoparticles, and the pursuit of groundbreaking remedies to neutralize their toxic impact. These findings advocate for a paradigm shift in how the coal mining industry views and handles particulate matter, proposing a re-evaluation of occupational health standards and a call to action for protecting coal miners worldwide.

Multi-Technique Assessment of Chelators-Loaded PVA-Borax Gel-like Systems Performance in Cleaning of Stone Contaminated with Copper Corrosion Products.

Currently, one of the most important challenges for the conservation of stone artworks is the removal of metal corrosion products on their surfaces. Traditional cleaning methods, which typically involve the application of aqueous solutions containing chelating agents capable of complexing these metal ions, have shown some weaknesses. These weaknesses become apparent when such methods are applied to statues and other vertical surfaces or when aiming to limit the cleaning process to a specific area with controlled application times. Furthermore, the porosity of the stone surface plays a role concerning the cleaning efficiency. To address these issues, chelating agents can be incorporated into gel-like materials. This study is a proof of concept to evaluate the cleaning efficacy of various gel formulations composed of polyvinyl alcohol (PVA), borax (B), and agarose (AG), loaded with two chelators: ethylenediaminetetraacetic acid (EDTA) and potassium sodium tartrate (PST or Rochelle salt). Three types of carbonate stones (travertine, Lecce stone, and Carrara marble) characterized by different porosities were artificially stained with copper sulphates and treated with the different PVA-B-AG formulations. The effectiveness of the treatment was directly monitored on the stones using a multi-technique approach that included scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and non-invasive portable nuclear magnetic resonance (NMR). Additionally, the rheological properties of the gels were investigated, and the Fourier transform infrared attenuated total reflection spectroscopy (FTIR ATR) was used to analyse the chemical structure of the gel before and after treatment, aiming to understand the changes induced by the cleaning process.

Structure Engineering of Ni/SiO2 Vegetable Oil Hydrogenation Catalyst via CeO2.

Inspired by our finding that metallic Ni particles could be uniformly distributed on a reduced CeO2 surface and stabilized on Ce3+ sites, we suppose a possible improvement in the activity and selectivity of the MgNi/SiO2 vegetable oil hydrogenation catalyst by increasing the surface metal Ni availability via modification by ceria. The proposed approach involved the addition of a CeO2 modifier to the SiO2 carrier and as a catalyst component. Evaluation of the structure, reducibility, and surface and electronic states of the CeO2-doped MgNi/SiO2 catalyst was performed by means of the Powder X-ray diffraction (PXRD), Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) combined with High-resolution transmission electron microscopy (HRTEM), Temperature-programmed reduction with hydrogen (H2-TPR), and H2-chemisortion techniques. So far, no studies related to this approach of designing Ni/SiO2 catalysts for the partial hydrogenation of vegetable oil have been reported. The added ceria impact was elucidated by comparing fatty acid compositions obtained by the catalysts at an iodine value of 80. In summary, tuning the hydrogenation performance of Ni-based catalysts can be achieved by structural reconstruction using 1 wt.% CeO2. The introduction mode changed the selectivity towards C18:1-cis and C18:0 fatty acids by applying ceria as a carrier modifier, while hydrogenation activity was improved upon ceria operation as the catalyst dopant.

Bioinformatics and functional analysis of EDS1 genes in Brassica napus in response to Plasmodiophora brassicae infection.

Enhanced Disease Susceptibility 1 (EDS1) is a key regulator of plant-pathogen-associated molecular pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) responses. In the Brassica napus genome, we identified six novel EDS1 genes, among which four were responsive to clubroot infection, a major rapeseed disease resistant to chemical control. Developing resistant cultivars is a potent and economically viable strategy to control clubroot infection. Bioinformatics analysis revealed conserved domains and structural uniformity in Bna-EDS1 homologs. Bna-EDS1 promoters harbored elements associated with diverse phytohormones and stress responses, highlighting their crucial roles in plant defense. A functional analysis was performed with Bna-EDS1 overexpression and RNAi transgenic lines. Bna-EDS1 overexpression boosted resistance to clubroot and upregulated defense-associated genes (PR1, PR2, ICS1, and CBP60), while Bna-EDS1 RNAi increased plant susceptibility, indicating suppression of the defense signaling pathway downstream of NBS-LRRs. RNA-Seq analysis identified key transcripts associated with clubroot resistance, including phenylpropanoid biosynthesis. Activation of SA regulator NPR1, defense signaling markers PR1 and PR2, and upregulation of MYC-TFs suggested that EDS1-mediated clubroot resistance potentially involves the SA pathway. Our findings underscore the pivotal role of Bna-EDS1-dependent mechanisms in resistance of B. napus to clubroot disease, and provide valuable insights for fortifying resistance against Plasmodiophora brassicae infection in rapeseed.

A novel approach for recovery of iron from copper slag using calcium salts.

Copper slag is not only a waste but it has many valuable and recoverable metals present in it such as iron. Therefore, this study focuses on the utilization of waste materials i.e., copper slag and tire char for iron recovery. Four calcium salts, i.e., CaCO3, Ca(OH)2, CaCl2, and CaSO4, with different dosages, reduction temperature, reduction time, and atmospheric conditions were investigated in order to find best reaction mechanism for iron recovery. Among these salts, the optimum conditions were determined: using CaCO3 under 0.384 of CaO/SiO2 molar ratio in a 60-min reduction period at 1473.15K temperature, that gives 91.14% iron recovery. Both FESEM-EDS data and chemical titration showed more than 70% of the highest iron grade in the recovered product. The analysis results indicate that main impurity in the whole procedure was carbon from coal char that reduces the iron grade. This research not only provides a novel way to recover iron from copper slag, but also provides a future direction to handle copper slag and tire char waste materials.

Natural and anthropogenic impact on the microclimate and particulate matter in the UNESCO show cave.

Particulate matter concentrations (PM10, PM2.5, PM1) and microclimatic parameters (air temperature, CO2) were monitored in the Skocjan Caves (Slovenia). The effects of tourist visits on the PM concentrations and the cave's microclimate are immediate and direct, but these values normalise relatively quickly. The results showed seasonal, diurnal, and spatial differences in all parameters studied. Due to the higher number of visitors, their influence on the cave's microclimate and PM10 and PM2.5 concentrations is greater in summer than in winter. The measured PM1 levels depend on the ventilation in the cave, as air transport plays an important role in their introduction into the cave. PM consists of minerals of natural origin resulting from the re-suspension of cave sediments due to strong air currents generated by the opening of the doors to tourists and their walks. The second most common influence is the anthropogenic phases originating from maintenance work in the cave, electronic devices, cave lighting and emissions from outside the cave (aerosols from the polluted Reka River, industry, traffic, gypsum waste disposal). In order to upgrade the sustainable use of the UNESCO-listed Skocjan Caves for tourism, we propose regular monitoring of PM and a detailed characterization of individual PMs and their sources, in addition to monitoring of the cave's microclimate and biology.

Quantitative Analysis of Morphology and Surface Properties of Poly(lactic acid)/Poly(ε-caprolactone)/Hydrophilic Nano-Silica Blends.

A quantitative analysis of the morphology, as well as an analysis of the distribution of components and surface/interfacial properties in poly(lactic acid)(PLA) InegoTM 3251D, poly(ε-caprolactone) (PCL) Capa 6800 and nano-silica (SiO2) Aerosil®200 blends, was conducted in this research. The study aimed to improve the understanding of how PLA, PCL, and nano-SiO2 interact, resulting in the specific morphology and surface properties of the blends. Samples were produced by varying the concentration of all three components. They were analyzed using SEM, EDS mapping, water contact angle measurements, surface free energy calculation, adhesion parameter measurements, and FTIR-ATR spectroscopy. The results showed that the addition of SiO2 nanoparticles led to an increase in the contact angle of water, making the surface more hydrophobic. SEM images of the blends showed that increasing the PCL content reduced the size of spherical PCL elements in the blends. FTIR-ATR analysis showed that SiO2 nanoparticles influenced the structure ordering of PLA in the blend with equal portions of PLA and PCL. In the samples with a higher PCL content, the spherical elements present in the samples with a higher PLA/PCL ratio have been reduced, indicating better interactions at the interface between PLA, PCL, and SiO2. SEM-EDS mapping of the PLA/PCL 100/0 blend surfaces revealed the presence of SiO2 clusters and the silicon (Si) concentration reaching up to ten times higher than the nominal concentration of SiO2. However, with the addition of 3% SiO2 to the blend containing PCL, the structure became more granular. Specifically, Si protrusions in the sample PLA/PCL 90/10 with 3% SiO2 displayed 29.25% of Si, and the sample PLA/PCL 70/30 with 3% SiO2 displayed an average of 10.61% of Si at the protrusion locations. The results confirmed the affinity of SiO2 to be encapsulated by PCL. A better understanding of the interactions between the materials in the presented blends and the quantitative analysis of their morphology could improve the understanding of their properties and allow the optimization of their application for different purposes.

Biocorrosion and Cytotoxicity Studies on Biodegradable Mg-Based Multicomponent Alloys.

Magnesium-based multicomponent alloys with different compositions, namely Mg60Al20Zn5Cu10Mn5 (Mg60 alloy), Mg70Al15Zn5Cu5Mn5 (Mg70 alloy), and Mg80Al5Cu5Mn5Zn5 (Mg 80) alloys, were prepared using the disintegrated melt deposition technique. The DMD technique is a distinctive method that merges the benefits from gravity die casting and spray forming. This approach facilitates high solidification rates, process yields, and reduced metal wastage, resulting in materials with a fine microstructure and minimal porosity. Their potential as biodegradable materials was assessed through corrosion in different simulated body fluids (SBFs), microstructure, and cytotoxicity tests. It was observed that the Mg60 alloy exhibited low corrosion rates (~× 10-5 mm/year) in all SBF solutions, with a minor amount of corrosive products, and cracks were observed. This can be attributed to the formation of the Mg32(AlZn)49 phase and to its stability due to Mg(OH)2 film, leading to excellent corrosion resistance when compared to the Mg70 and M80 alloys. Conversely, the Mg80 alloy exhibited high corrosion rates, along with more surface degradation and cracks, due to active intermetallic phases, such as Al6Mn, Al2CuMg, and Al2Cu phases. The order of corrosion resistance for the Mg alloy was found to be ASS > HBSS > ABP > PBS. Further, in vitro cytotoxicity studies were carried out using MDA-MB-231 tumor cells. By comparing all three alloys, in terms of proliferation and vitality, the Mg80 alloy emerged as a promising material for implants, with potential antitumor activity.

Assessment of microplastics in coastal ecosystem of Bangladesh.

Microplastics (MPs) pose one of the major environmental threats to marine organisms and ecosystems on a global scale. The present study investigated MPs in surface water, beach sediments, and fish in two coastal areas of Bangladesh namely Cox's Bazar and Kuakata. The MPs were identified and characterized using three different techniques, including the binocular microscope, the ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy), and SEM-EDS (Scanning Electron Microscopy- Energy Dispersive Spectroscopy). The number of MPs in seawater was 10.1 ± 3.10 and 8.52 ± 3.92 items/100 L and in beach sediment, 13.2 ± 3.68 and 9.48 ± 3.63 items/100 g in Cox's Bazar and Kuakata, respectively. In fish samples, the abundance of MPs was 7.82 ± 1.28 and 6.82 ± 1.87 items/individual species of Cox's Bazar and Kuakata, respectively, where the highest quantities of MP were found in Euthynnus affinisand Sillago sihama and the lowest in Terapon jarbua and Pampus chinensisin Cox's Bazar and Kuakata, respectively. The number of MPs in GITs (Gastrointestinal tracts) was 1.63 ± 0.991 and 1.25 ± 0.546 items/g GIT and in BW (Body Weight) were 0.042 ± 0.014 and 0.037 ± 0.014 items/g BW in Cox's Bazar and Kuakata, respectively. There revealed a positive correlation between MP abundance and GIT weight and body weight in fish species. MPs were predominantly fiber-shaped, white/transparent, and small size. The most common MP polymers were polyethylene and polypropylene. SEM images of MPs demonstrate surface roughness, cracks, mechanical weathering and oxidative weathering, demonstrating their ongoing environmental exposure. The EDS spectrum unearthed that the MPs contained several elements (C, N, O, Na, Al, Fe, and Si). Findings from this study might be useful in coastal plastic particle management and to mitigate the potential risks associated with them.