Scanning Electron Microscopy-energy Dispersive Spectroscopy Research Articles

Occupancy Determination from Resonant X-ray Diffraction.

We analyze the effect of integrated resolution, data scaling, structural refinement, and crystal symmetry on the extracted scattering perturbations and their uncertainties for anomalous (resonant) X-ray diffraction on mixed-metal molecular clusters. We probe the metal constituency, substitutional homogeneity, and positional disorder of both biased and unbiased ligand environments. Anomalous X-ray diffraction studies were conducted on (FtbsL)Zn2Ni(py) (1), [K(C222)][(FtbsL)Zn2Ni] (2), and [K(THF)3][(FtbsL)Zn2Ni(NAd)] (3). Analysis of diffraction data collected at energies along the Ni and Zn K-edges on [Zn2Ni] clusters reveals data resolution, and the accuracy of the structural model greatly impacts the resonant scattering factors (f', f″) and their uncertainties. Occupancy studies on all three clusters were conducted in three ways and compared: (i) using the f' values of each metal site refined from diffraction data collected at energies along the Ni and Zn K-edges; (ii) using the f' value of each metal site refined from diffraction data collected with in-house, Cu Kα radiation; and (iii) refining each metal site as a Zn/Ni disordered pair and fixing the relative Zn-to-Ni occupancies as 2:1 across the core with supporting spectroscopic evidence from scanning electron microscope energy-dispersive spectroscopy. First, we observe highly ordered structural compositions, even when statistical mixing was anticipated; and second, we discovered that in-house X-ray diffraction collection was as precise in composition determination as synchrotron sources for this study.

Enhancing Cassava Starch Bioplastics with Vismia guianensis Alcoholic Extract: Characterization with Potential Applications

This work investigates the incorporation of Vismia guianensis alcoholic extract (EAVG) into cassava starch, with the aim of improving its bioplastic properties. Cassava starch was dissolved into distilled water and doped with 0.2%, 0.5%, and 1.0% EAVG under a temperature controlled at the gelatinization point (∼70 °C) and then cast to form bioplastics. The resulting samples were characterized via attenuated total reflectance/Fourier transform infrared spectroscopy (ATR/FTIR), thermogravimetric and differential thermal analysis (TGA-DTA), X-ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), atomic force microscopy (AFM), and mechanical essays, providing insights into chemical composition, thermal stability, crystallinity, surface morphology, and mechanical properties. The results demonstrated that EAVG played an effective role, enhancing the flexibility and stability of the bioplastic with potential use in biomedical applications. Moreover, the results also showed significant improvements in mechanical and thermal properties, suggesting that EAVG is a valuable addition to bioplastics. Therefore, EAVG presents a pathway for advancing bioplastics with enhanced mechanical, thermal, and functional characteristics, with the potential for further advancements in these fields.

Biosorption of Cr (III) from Polluted Water Using Pennisetum clandestinum Hochst (Kikuyo)

Given the abundance of kikuyu biomass resulting from the pruning of green areas, the aim of this study was to evaluate its use as a biosorbent (BK) for Cr (III) removal from polluted waters. The biomass was activated using H2SO4 (1.25%) and NaOH (3.25%). The characterization methods were Fourier-Transform Infrared Spectroscopy (FTIR), scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS), and Brunauer–Emmett–Teller (BET) analysis. Our results confirmed the presence of active groups on BK, such as –OH, -C=C-, -C=O, and -C-O-, with an increase of 1308.58% in specific surface area, as well as the presence of chromium on the biosorbent after adsorption process. The adsorption capacity (q) was tested in a jar test as a function of biomass granulometry, dose (BK), and the pH of the solution; the best response was 47.9 mg/g at a pH of 5.5, a biosorbent dose of 0.5 g/L, and a biosorbent size of 100 μm. The effect of pH was positive; by increasing the pH, the adsorption capacity increased. However, the effect of the biosorbent dose and size was negative, as when increasing the dose and granulometry, the adsorption capacity decreased. In addition, the kinetic process was studied, where the removal data were better fitted for the pseudo-second-order kinetic model, confirming that the adsorption mechanism was chemisorption. The adsorption capacity was 37.6 mg/g for industrial wastewater. The possibility of using kikuyu within the circular economy was demonstrated and suggests its application in continuous systems for real-world environmental conditions.

Using One-Part Geopolymer in Stabilizing High-Water-Content Soft Clay: Towards an Eco-Friendly and Cost-Effective Solution

To achieve environmental and economic goals in ground improvement, a one-part geopolymer (OPG), synthesized from binary precursors (fly ash [FA] and granulated blast furnace slag [GGBFS]) and a solid activator (solid sodium silicate [NS]), was used to replace ordinary Portland cement (OPC) for stabilizing high-water-content soft clay. The effects of different initial water content (50%, 80%, 100%, and 120%) and various OPG binder content (10%, 20%, 30%, and 40%) on the strength development of the OPG-stabilized soft clay were investigated through unconfined compressive strength (UCS) and unconsolidated undrained (UU) triaxial tests. Additionally, the microstructure evolution and the distribution of pores in the OPG-stabilized soft clay were examined by the utilization of mercury intrusion porosimetry (MIP) and scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) techniques, respectively. The life cycle assessment (LCA) methodology was then used to analyze the environmental and economic advantages of employing an OPG binder for soil stabilization. It was revealed that the optimal content of OPG binder was contingent upon the water content of soft clay, with variations in requirements for strength development. Specifically, for soft clay not demanding early strength, a maximum binder content of 20% is proposed. Conversely, for soft clay that necessitated rapid strength gain, the OPG binder content escalated with increasing water content of the soft clay, in which soft clays with different water contents had corresponding required amounts of OPG binder. For soil with water content ranging from 50% to 80%, the recommended OPG binder content is 20%. While for soil with 100% and 120% water content, the designed OPG binder content is suggested to be 30% and 40%, respectively. The environmental assessment demonstrated that the utilization of OPG as a binder for the stabilization of soft clay reduces costs and carbon emissions in comparison to OPC. The present study provides substantial theoretical validation for the utilization of OPG as a novel binder to stabilize soft clay with elevated water content, which holds promise as an eco-friendly and cost-effective solution in ground improvement.

Synthesis of rice husk–based–mesoporous silica nanoparticles by facile calcination

Abstract The growing industrial demand for mesoporous silica nanoparticles (MSNs) necessitates the exploration of alternative raw materials due to the limited availability of traditional sources. Rice husk, an environmentally sustainable by-product, offers a cost-effective solution with reduced environmental impact. This study investigates the synthesis of MSNs from rice husk using the sol-gel method, focusing on the effect of calcination temperature on their physical and chemical properties. Characterization confirmed the successful synthesis of MSNs. Fourier transform infrared spectroscopy identified siloxane groups in all samples, indicating silicate materials. Scanning electron microscopy-energy dispersive spectroscopy revealed a spherical-like morphology with silica as the primary component. Transmission electron microscopy measured the average particle sizes of control, 400°C calcined, and 600°C calcined MSNs as 50.5 nm, 49.3 nm, and 53.1 nm, respectively. X-ray diffraction analysis indicated the presence of silica phases in all samples. Surface area analysis showed a significant decrease in surface area (653 m²/g to 113 m²/g) and pore volume (0.9 cm³/g to 0.1 cm³/g) with increasing calcination temperature, while pore size slightly increased from 2.6 nm to 2.7 nm. Calcination temperature influences the removal of CTAB surfactants, enhances silicate bond strength, and increases silicon purity, resulting in reduced surface area and pore volume without altering the basic morphology or crystal structure of the MSNs. The synthesized MSNs, with their large surface area and unique properties, demonstrate potential for diverse applications, including their use as nanocontainers for corrosion inhibitors

Recovery of Scandium from Bauxite Residue Using Sulfation Roasting-Assisted Water Leaching Process

ABSTRACT This study presents a method for recovering scandium from Indonesian bauxite residue (red mud) through a sulfation roasting-assisted water leaching process. Ammonium sulfate, (NH4)2SO4, was chosen as the sulfate source for its lower melting point, less corrosivity, decreased toxicity, and the potential for ammonia recovery. A modified mixing system was introduced to improve the distribution of (NH4)2SO4 on red mud particles by combining them in water. A series of experiments were conducted to optimize the sulfation roasting process by examining the effects of the (NH4)2SO4/red mud ratio, temperature, and roasting time. Subsequently, water leaching was optimized while considering the effect of leaching time and liquid-to-solid (L/S) ratio. The leaching of scandium from the roasted red mud showed rapid kinetics, even when using only water. Under the roasting conditions of 1/1 (g/g) (NH4)2SO4/red mud ratio, 700°C, 60 min roasting time, and the leaching conditions of 65°C, 60 min, and 10 mL/g (L/S), over 90% of scandium was recovered, along with 64.4% Al leaching and below 8% Fe leaching. These results were further corroborated through comprehensive analyses such as x-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). This study offers insights into an alternative, more environmentally friendly method for Sc recovery from red mud, promoting the sustainable use of hazardous waste like red mud.

Genome-Wide Identification and Characterization of the Homeodomain Leucine Zipper Protein (HD-Zip) Gene Family in Sea Buckthorn (Hippophae rhamnoides) Under Lead Stress

This study investigates the role of sea buckthorn HD-Zip genes in response to lead stress, identifying 28 genes distributed across 10 chromosomes, which are classified into four subfamilies. Each subfamily exhibits a similar gene structure and conserved protein motifs. The HD-Zip gene family is notably enriched in stress-responsive elements. Transcriptomic analysis revealed differential expression among the 28 members of the HD-Zip gene family in sea buckthorn, varying with different Pb ion concentrations. Upregulated genes were predominantly observed at stress concentrations of 1 g/kg and 5 g/kg, while downregulated genes were more prevalent at the 0.5 g/kg stress concentration. Covariance analysis indicated that large-scale gene duplication was the primary mechanism driving the expansion of the sea buckthorn HD-Zip gene family. Additionally, analysis of three-dimensional protein structures demonstrated high conservation within the HD-Zip gene, suggesting that certain sea buckthorn HD-Zip proteins may play significant regulatory roles in physiological functions. Scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS) analysis revealed that the majority of lead ions accumulated in the roots of the seedlings, with the lead concentration affecting the number, density, and function of leaf slits. These findings enhance our understanding of the complex regulatory mechanisms governing HD-Zip genes and will contribute to the genetic improvement of sea buckthorn for breeding under lead stress conditions.

Effect of growth dynamics on the structural, photophysical and pseudocapacitance properties of famatinite copper antimony sulphide colloidal nanostructures (including nanosheets).

Facile phase selective synthesis of copper antimony sulphide (CAS) nanostructures is important because of their tunable photoconductive and electrochemical properties. In this study, off-stoichiometric famatinite phase CAS (fCAS) quasi-spherical and quasi-hexagonal colloidal nanostructures (including nanosheets) of sizes, 2.4-18.0 nm were grown under variable conditions of temperature (60-200 °C), time and oleylamine capping ligand concentration using copper(II) acetylacetonate and antimony(III) diethyldithiocarbamate precursors. Data from powder X-ray diffraction, Raman spectroscopy and high-resolution scanning/transmission electron microscopy confirm the tetragonal structure of the famatinite phase. X-ray photoelectron spectroscopy, transmission electron microscopy and scanning electron microscopy-energy dispersive X-ray spectroscopy data suggest a correlation of particle size, morphology and composition of the off-stoichiometric fCAS nanostructures with growth temperature and time, and oleylamine concentration. The off-stoichiometric Cu3-aSb1+bS4±c (a, b, c - mole fractions) nanostructures being severely copper-deficient and antimony-rich, exhibit shallow-lying acceptor copper vacancy states, deep-lying donor states of antimony interstitials, sulphur vacancies and antimony-copper antisites and shallow-lying acceptor surface trapping states. These electronic states are likely implicated in tunable UV-visible absorption and bandgaps between 2.3 and 2.8 eV, and broad visible-NIR photoluminescence with fast recombination of radiative lifetimes between 0.2 and 6.2 ns, confirmed from absorption, steady-state and time-resolved photoluminescence spectroscopies. Additionally, cyclic voltammetry and electrochemical impedance spectroscopy confirm that electrodes of the fCAS nanostructures display slightly variable pseudocapacitance of charge-storage primarily via possible sodium ion intercalation with a high specific capacitance of ∼84 F g-1 obtained at a scan rate of 5 mV s-1. Overall, these results show the influence of composition, in particular point defects, phase quality and morphology on the optical and pseudocapacitance properties of fCAS nanostructures, suitable as solar absorbers or electrodes for energy storage devices.

Photothermal Coating on Zinc Alloy for Controlled Biodegradation and Improved Osseointegration.

Zinc (Zn) and its alloys are promising biomaterials for orthopedic applications due to their degradability and mechanical properties. Zn2+plays a crucial role in bone formation, but excessive early release may cause cytotoxicity and inhibit osseointegration. To solve this, we developed a near-infrared (NIR) light-controlled polycaprolactone/copper-sulfur (PCL/CuS) coating that slows degradation and enhances osseointegration of Zn alloys. The zinc-lithium (Zn-Li) substrate is encapsulated with PCL, reducing Zn2+ release and maintaing biocompatibility. Controlled Zn2+ release and mild photothermal therapy via CuS nanoparticles promoted osteogenesis. In vitro studies demonstrated enhanced cell proliferation and osteogenic differentiation. In vivo Micro-Computed Tomography (Micro-CT), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), and immunohistochemical analyses confirmed improved osseointegration. Mechanistic studies using RNA sequencing and Western blotting revealed that the coating promotes osteogenesis by activating the Wnt/β-catenin and inhibiting NF-κB pathways. This NIR light-controlled PCL/CuS coating successfully regulates Zn alloy degradation, enhances osseointegration via controlled Zn2+ release and mild photothermal therapy effct, presenting a promising avenue for orthopedic biomaterials.

Molecular spectroscopic and elemental analyses for the identification of multi-layered automotive coatings with Fourier Transform Infrared Spectroscopy (FTIR), Raman Microscopy and Scanning Electron Microscopy-Energy Dispersive Spectroscopy

Common automotive coatings include acrylic, amino, alkyd, polyester, nitro, and polyurethane coatings. In addition to these coatings, pigments, such as Prussian Blue, phthalocyanine blue, toluidine red, and scarlet powder are commonly added. Additives including sulphate, chrome yellow, CaCO3(calcium carbonate), TiO2(titanium dioxide), talc, dolomite and kaolin, are also commonly included in the coatings. The combination of these components makes it complex to identify them as a whole. However, the analysis of automotive coatings is not only important for coating producers in the industrial field, but also for forensic scientists investigating hit-and-run accidents. In this study, the authors aimed to establish a method that combines FTIR, Raman spectroscopy and SEM-EDS to investigate complex and multi-layered paint samples. As a result, comprehensive and detailed molecular spectroscopic and elemental information was successfully obtained for identification using this method. FTIR proved advantageous in analyzing resins, while Raman was more effective in characterizing additives and pigments. The selection criteria for infrared spectroscopy are based on the change in dipole moment in molecular vibration, while those for Raman spectroscopy are based on the change in molecular polarization. Raman spectroscopy and infrared spectroscopy have complementary application fields and can be used together to provide more comprehensive molecular vibration information. SEM-EDS can also accurately present elemental components. With this method, tiny differences in spectra can be clearly distinguished through mutual verification; corresponding components in paints can be confidently identified.

Photocatalytic, antibacterial and antioxidant study of Vitex negundo mediated green synthesized nickel and neodymium doped zinc oxide nanoparticles

This investigation delves into diverse attributes of environmentally friendly nickel-doped zinc oxide and neodymium doped zinc oxide nanoparticles. It focuses on evaluating their effectiveness in photocatalysis, antibacterial activity and antioxidant properties. Utilizing a sustainable synthesis approach incorporating phytochemicals from Vitex negundo, hexagonal structures of both nickel-doped zinc oxide and neodymium-doped zinc oxide nanoparticles were confirmed through X-ray diffraction analysis. Transmission electron microscopy and scanning electron microscopy-energy dispersive X-ray spectroscopy analyses identified spherical nanoparticles with size between 8 and 15 nanometers. Photocatalytic assessments using methyl green dye degradation demonstrated promising results for both nickel-doped zinc oxide and neodymium-doped zinc oxide nanoparticles. Antibacterial tests showcased nanoparticle’s ability to disrupt Bacillus subtilis and Escherichia coli, with neodymium doped zinc oxide nanoparticles exhibiting superior antibacterial activity. Antioxidant potential, evaluated through 2,2-diphenyl-1-picrylhydrazyl free radical assay, highlighted nanoparticles radical-scavenging ability, with neodymium doped zinc oxide nanoparticles showing enhanced activity due to phytochemicals introduced during green synthesis. This research innovates through green synthesis of nickel-doped zinc oxide and neodymium-doped zinc oxide nanoparticles, capitalizing on their distinctive properties for synergistic applications. The study provides valuable insights into potential future applications, offering novel solutions for environmental remediation and biomedical purposes.

A Realistic 3D Grain-Based Modeling Approach for Reproducing the Mechanical and Failure Behavior of Brittle Granites

Exploring cracking behavior from mineral-scale do good help to understand the failure mechanism of rock materials. The present study proposes a realistic three-dimensional grain-based modeling (3D-GBM) method considering the actual distribution, geometry and mesoscopic mechanical properties of different minerals in granite samples. The geometrical characteristic and distribution were captured based on high-precision computed tomography (CT) scanning and polarized microscopy. The mesoscopic mechanical properties were measured using nanoindentation combined with the scanning electron microscope-energy dispersive spectroscopy scanning (SEM-EDS). The results indicate that the established model can realistically reproduce the mechanical and failure behavior of granite subjected to unconfined compression in terms of stress-strain curves, failure mode, crack evolution, and force transmission. Investigating crack propagation at mineral-scale shows that the relative damage degree is greater at weak boundaries (i.e., boundary related to mica) and relatively soft minerals (i.e., mica) than that of strong boundaries (i.e., quartz-quartz and quartz-feldspar) and stiffer minerals (i.e., quartz and feldspar). Grain boundaries and soft mica minerals play an important role in guiding and deflecting the crack propagation path due to the mismatch in elasticity and strength compared with the stiffer and harder minerals (i.e., quartz and feldspar).

In-situ formation mechanism of endogenous fluorescent carbon dots during the roasting process of small yellow croaker (Larimichthys polyactis).

The endogenous fluorescent carbon dots (FCDs) existed in roasted foods, leading to extensive attention due to their physicochemical properties and potential biotoxicity. Therefore, the in-situ formation mechanism and physicochemical properties of endogenous FCDs in roasted small yellow croaker (Larimichthys polyactis) were investigated. The fluorescence spectrum of FCDs underwent a blue-shift with an increase in the roasting temperature. Scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) analysis revealed that FCDs primarily consisted of C and O, exhibiting significant variations across different roasting temperatures (180°C, 200°C, and 220°C). The in-site variable temperature-Fourier transform infrared (VT-FTIR) spectrum demonstrated notable changes as the temperature increased from 26°C to 220°C. This was due to the thermal aggregation of biological macromolecules such as proteins and fats, leading to thermal decomposition and disintegration, resulting in the formation of FCDs (∼5nm). These results provided a theoretical basis for controlling the formation of FCDs in aquatic products during heat processing.

Mineralogy and geochemistry of sands from Playa las Golondrinas, Puerto Rico: an approach to establishing a geogenic background

Sands from the dune, berm, and shore environments at Playa las Golondrinas (18° 30′ 51″ N, 67° 3′ 26″) were investigated to explore how beach sands could be applied as a potential environmental (geogenic) background for the local region. Grain size is dominantly unimodal classifying as fine to medium sand. Hydraulic conductivity values range from 1.07 cm/s (berm) to 1.49 cm/s (shoreface). Sample mineralogy as constrained by X-ray diffraction (XRD) reveals a dominance of quartz and feldspar with minor Mg-calcite, pyroxene, and olivine. Light microscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM–EDS) support XRD data and indicate the presence of oxide-bearing lithic fragments in addition to biologic materials (e.g., corals. forams). Reflective spectra are consistent with XRD and microscopy. Bulk element concentrations determined using inductively coupled plasma—mass spectrometry (ICP-MS) are consistent with derivation from the arc-related rocks of Puerto Rico’s interior exhibiting LILE enrichment, Pb-enrichment, and associated Nb–Ta depletion. The majority of the bulk elemental concentrations are below those of average upper continental crust (UCC) values and element co-variation trends (e.g., wt. % Fe2O3 vs. As) are interpreted as geogenic in origin. Berm sands are enriched in Fe, Mn, Ni, Cr, V, and As compared to dune and shore samples and this signature is interpreted as being from a wind-driven winnowing effect. The exact form of As (As3+ or As5+) remains unconstrained and thus it is unknown if As is mobile in this environment. Reflective spectra, supported by grain size, mineralogy, and bulk chemistry, enables future remote sensing investigations by providing detailed constraints on sand in environmentally sensitive areas. This study therefore provides local context for metal pollution studies across the region.

Impact of Calcium Hydroxide Particle Size on the Intracanal Medicament Penetration Efficacy

Calcium hydroxide (Ca (OH)2) is an intracanal medicament used as a disinfectant in cases of tooth inflammation with ad dubia prognosis. The success of root canal treatment depends on the ability of intracanal medicaments to eliminate pathogenic bacteria present in the walls of narrow and complex root canals by releasing calcium and hydroxyl ions at the closest contacts. This study aimed to evaluate the effect of particle size on the ability to penetrate Ca (OH)2 in the coronal, middle, and apical root canals. Fifteen mandibular premolars extracted for orthodontic and periodontal purposes were collected and cut to produce root canals with a length of 12 cm. The root canals were then prepared with a Protaper SX-F3 needle and irrigated using a solution of 2.5% NaOCl, NaCl, and 17% EDTA as lubrication at each needle change. Ca (OH)2 with different particle sizes in paste form was manipulated with distilled water at a concentration of 0.8 g/mL then the paste was applied to the prepared tooth root canals and covered with a temporary filling. The samples were then stored in an incubator at 37 °C for 7 days. Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) was performed on the transverse surfaces of the coronal 1/3, middle 1/3 and apical 1/3 of the tooth. The maximum penetration depth was evaluated by measuring the maximum distance between the dentin canal wall and Ca (OH)2 present in the dentinal tubules. In all three zones, the Ca (OH)₂ nanoparticles had a greater penetration depth than the Ca (OH)₂ nanoparticles (P<0.001). In both groups, the penetration depth increased from the apical to the coronal section. All differences in the penetration test ability of the Ca (OH)₂ nanoparticles and Ca (OH)₂ microparticles at all depths of the surface. Ca (OH)₂ nanoparticles penetrate deeper into the dentinal tubules than Ca (OH)₂ microparticles do.

Recent advances in research from plastic materials to microplastics

Plastics have become ubiquitous in our lives. Due to the ever-increasing population, rapid urbanization, and industrial advancement, the use of plastics has increased manifold. These plastic materials often disintegrate into microplastics (MPs) which are less than 5mm in size. MPs mostly enter aquatic habitats through improper waste management, illegal dumping, and unavoidable and unintentional discharges that take place during construction, manufacturing, farming, domestic consumption, and recreational activities. This review centers on exploring the origin, occurrence, and possible adverse effects of MPs on human well-being. Of the 485 literature reviewed for the study between 2014- 2023, 105 were found to be related to the MPs which were spread over 10 themes. The maximum number of papers were on sources of MPs, followed by MPs in freshwater ecosystems and waste management. The least number of literature was from the themes, transport of MPs and MPs in the soil environment. The literature was published mostly in China, India, Europe, and the Americas. Other countries like Australia, Latin America, Africa, and the Middle East contribute very little. The literature scan reveals that only 9% of all the generated plastic waste material is recycled, 12% is burned, and 79% of plastic litter is dumped in landfills and oceans. The dumped plastic settles and pollutes a variety of environmental matrices. MPs are intentionally manufactured to be added to personal care products that are washed down the drains through sewage or industrial wastewater. These MPs vary in density and colour, subject to the polymer type, and are present in varying sizes and concentrations in aquatic environments. The characterization of MPs originating from different types of polymer materials, in the reviewed literature, was performed based on the data obtained from Scanning Electron Microscopy Energy Dispersive Spectroscopy (SEM-EDS), Attenuated Total Reflection Fourier Transform Infra-Red spectroscopy (ATR-FTIR), Raman spectroscopy, and Atomic Force Microscopy (AFM). MPs have the potential to absorb harmful hydrophobic pollutants from the surroundings resulting in an indirect transfer of contaminants into the food web. Such MPs enter and affect humans, causing problems with the reproductive system, body weight, sex ratio, and live births. MPs pose a serious threat to organisms when ingested since they can obstruct the digestive tract, leading to oxidative and pathological stress, slowing down growth, and interfering with reproduction. Apart from the above, a comprehensive analysis of MP pollution, as well as its effect on human beings and the environment, has been discussed in terms of source identification and abundance. Also, has been discussed is a detailed review of the existing waste material recycled into new materials or reused without alteration or degradation to produce new energy sources. In the end, integrated strategies have been proposed to prevent the input of plastic waste material into the environment, by source control, improved plastic waste management, and techniques for degradation and conversion of MPs.

Failure Behavior of Nano-Metakaolin Concrete Under Splitting Tension Based on Digital Image Correlation Method.

Nano metakaolin (NMK) has attracted considerable interest for its potential to improve the durability of cementitious materials. However, the effect of NMK on the splitting tensile performance of concrete has not been systematically investigated. This study investigates the splitting tensile performance of NMK concrete and analyzes its failure behavior under splitting load. Different NMK dosages (0%, 1%, 3%, 5%, and 7%) were considered, and splitting tensile tests were conducted. The crack propagation process, crack width, and crack growth rate on the surface of NMK concrete during the splitting tensile test are analyzed using the Digital Image Correlation (DIC) method. The mechanisms by which NMK affects the splitting tensile performance of concrete were examined using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS), and Thermogravimetric Analysis (TG). The results indicate that the incorporation of NMK enhances the splitting tensile performance of concrete. Concrete with 5% NMK addition exhibited the highest splitting tensile strength, with an increase of 17.4% compared to ordinary concrete. NMK improved the cracking resistance and overall integrity under splitting tensile load. With 5% NMK addition, the surface crack length, width, and main crack propagation rate of the concrete decreased by 4.5%, 35.3%, and 29.6%, respectively. NMK contributed to a denser internal structure of the concrete, promoted the formation of C-S-H gel, and increased the degree of cement hydration. Moreover, a lower thickness and Ca/Si ratio of interfacial transition zone (ITZ) were observed in NMK concrete. The ITZ thickness and Ca/Si ratio of concrete with 5% NMK were reduced by 64.4% and 85.4%, respectively, compared to ordinary concrete. In summary, the influence mechanism of NMK addition on the splitting tensile strength and failure behavior of concrete is explored in this study, providing experimental data to support the application of NMK concrete in practical engineering.

Safety Study and Compositional Analysis of the Svarnvir-IV Tablet With Special Reference to Its Therapeutic Utility in SARS-CoV-2.

Aim Traditional Ayurvedic herbo-mineral medicines have proven their potential in managing COVID-19. Cell-based assays of the Svarnvir-IV tablet demonstrated the virucidal activity against SARS-CoV-2 and its therapeutic action, along with safety in cytotoxicity, has been proved. In the present study,in vivo,safety profile and compositional analysis of the Svarnvir-IV tablet were performed. Methods The safety and potency of the Svarnvir tablet were evaluated comprehensively throughin vivodrug screening onDrosophila,along with elemental composition analysis of Svarnvir tablets using atomic absorption spectroscopy (AAS), inductively coupled plasma-mass spectroscopy (ICP-MS), X-ray diffraction (XRD), and scanning electron microscopy energy dispersive spectroscopy (SEM-EDS). Results The Svarnvir tablet was found safe inDrosophilaand their larvae up to the dosage of 1 mg/ml. In comparison to the control, morphologically and physiologically healthy and active flies were observed without any change in circadian locomotor activity rhythms or activity patterns. In addition, the elemental composition of Svarnvir tablets was evaluated using AAS, ICP-MS, and SEM-EDS, and the microstructure was examined by means of XRD and SEM. Conclusions Overall, these findings will contribute to an accessible and safe therapeutic approach for traditional age-old Ayurvedic medication to combat SARS-CoV-2 variants.

Development and characterization of nitazoxanide-loaded poly(ε-caprolactone) membrane for GTR/GBR applications

ObjectiveGuided tissue/guided bone regeneration (GTR/GBR) membranes are widely used for periodontal bone regeneration, but their success depends on a bacteria-free environment. Systemic antibiotic treatment often proves inadequate, moreover, the increasing prevalence of antibiotic resistance in oral infections exacerbates this challenge. This study aimed to fabricate antibacterial membranes using a new class of antibiotics for local drug delivery, to eradicate infections and promote tissue regeneration. MethodsMembranes loaded with nitazoxanide (NTZ) were fabricated via electrospinning using poly(ε-caprolactone) (PCL) with varying concentrations of NTZ (0 %, 2.5 %, and 5 % w/w) relative to the polymer weight. Morphochemical of NTZ-loaded membranes were assessed using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and Fourier Transform Infrared spectroscopy (FTIR). Mechanical properties were evaluated using universal testing machine and NTZ release profile from membranes was determined by spectrophotometer (λmax = 444) for 14 days. Antimicrobial efficacy against periodontal pathogens, cell compatibility and mineralization were evaluated using periodontal ligament stem cells (PDLSCs). ResultsOptimized spinning parameter maintained a uniform fiber diameter and successful loading of NTZ was confirmed by SEM-EDS and FTIR. NTZ incorporation did not significantly affect mechanical properties, whereas the drug release kinetics showed an initial burst, followed by sustained release over 14 days. NTZ-loaded membranes demonstrated antibacterial activity against Aggregatibacter actinomycetemcomitans (Aa) and Fusobacterium nucleatum (Fn). Importantly, the presence of NTZ showed minimal cell toxicity; however, it reduced the mineralization potential compared with that of the pure PCL membrane, which increased over time. SignificanceTaken together, these findings established that NTZ-loaded membranes could be promising barrier membrane to counteract microbial environment and aid periodontal bone regeneration.

Evaluation of Phenolic Foam's Toxicity Used in Floral Arrangements

AbstractThe study investigates the characterization and toxicity of two types of phenolic foams: Floral (FF) and Hydroponic (HF), used in floral arrangements and hydroponic structures. These foams contain a resin with a free phenol content ranging between 5.0% and 8.0%, a substance harmful to plant development and ecosystem contamination. Methods such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy‐energy dispersive spectroscopy (SEM‐EDS), and gas chromatography‐tandem mass spectrometry (GC‐MS/MS) are used for characterization. Acute exposure ecotoxicological tests are conducted with Daphnia magna for the FF sample and lettuce seeds (Lactuca sativa) for both FF and HF samples. Results reveal structural similarities between the foams and phenolic resin, including the presence of residual free phenol at concentrations of 180 ppm in FF and 73 ppm in HF, and possibly different additive treatments between samples. The FF sample had a half maximal effective concentration (EC50, 48 h) = 15.4 ± 2.7 g L−1 for D. magna. Surprisingly, the HF sample proves more toxic to L. sativa than FF, suggesting a potential influence of additives released from the sample's composition beyond the free phenol. This study shows that improper phenolic foam disposal can harm both aquatic and land ecosystems.