Energy Dispersive X-ray Analysis Research Articles

Unlocking treasure from fish bones: bioinspired hydroxyapatite synthesis from Catla catla fish for sustainable waste-to-wealth

Abstract This study presents an innovative and sustainable method for synthesizing hydroxyapatite (HA) from Catla catla fish bones, addressing the need for environmentally friendly materials in biomedical applications. Fish bone waste is transformed into high-performance HA through acid pre-treatment, oven drying, and calcination at 900 °C. Characterization via Fourier-transform infrared spectroscopy and X-ray diffraction confirms the formation of HA with particle sizes ranging from 0.3–0.8 µm, which is ideal for enhancing surface area in biomedical contexts. Scanning electron microscopy and energy-dispersive X-ray spectroscopy reveal a highly porous structure and a Ca/P ratio of 1.68, closely resembling natural bone composition. The bioactivity of HA was evaluated using simulated body fluid over 7 and 28 days, with scanning electron microscopy and energy-dispersive X-ray analyses confirming hydroxycarbonate apatite layer formation, indicated by increased Ca and P content. X-ray diffraction further validates the bioactive nature of HA. In-vitro degradability testing demonstrated controlled degradation over 28 days, alongside pH changes in the SBF solution. Cytotoxicity analysis using human Wharton’s jelly mesenchymal stem cells confirmed the non-toxic nature of HA, showing a cell viability rate of 89.7 ± 3.1 % after 48 h. These findings emphasize the potential of fish bone-derived HA to be used in coating orthopedic and dental implants, creating porous bone scaffolds, and formulating bone cement, establishing it as a highly promising material for diverse biomedical applications.

Highly tunning of dielectric and photocatalytic properties of crystalline ZnO semiconductor: functionality of Ba additives

Abstract In the present work, the concentration of Ba-additive played a significant role in advancing the dielectric properties and photo-removal activity of ZnO semiconductor for methylene blue dye. Ba doped ZnO semiconductor with different doping concentrations (Zn1-xBaxO, x = 0.003, 0.005, 0.007 and 0.009 wt.%) were grown by solid-state reaction route. The X-ray diffraction (XRD) data confirmed the formation of the wurtzite structure of ZnO along with the presence of BaO-based secondary phase (SP). The XRD peak intensity related to the SP was found to increase with the increase of Ba concentration. Microstructural analyses through scanning electron microscope (SEM) images and energy-dispersive X-ray analysis (EDS) showed that with the addition of Ba, a gradual increase in the grain size was observed. Furthermore, SP segregated at the grain boundary and showed an increasing trend with doping. The emergence of secondary phases with Ba concentration was confirmed with the help of supplementary spectroscopic characterizations including Fourier transform infrared spectroscopy (FTIR) and UV-Vis diffuse reflectance. The presence of BaO secondary phase has shown a benefit effect on the dielectric and photodegradation properties of ZnO material. The remarkable resistance reduction suggested that the higher Ba concentrations significantly enhance charge carrier mobility. For wastewater treatment uses, BZO9 photocatalyst exhibited a perfect degradation efficiency of 90.1% for methylene blue (MB) removal after 210 min of visible light illumination.

Surfactant-Assisted Synthesis of Metallic-Ag/Nickel Oxide on Graphitic Carbon Nitride Composite: An Electrochemical Investigation of Synthetic Vanillin.

In this study, we developed a sensor based on surfactant-assisted synthesis of metallic silver-enriched nickel oxide confined on graphitic carbon nitride (Ag/NiO/g-CN)-modified electrode to construct a sensitive and selective voltammetric sensor for detecting vanillin in confectionaries samples. The X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy analyses confirmed the crystal structure and respective functional groups of the synthesized Ag/NiO/g-CN composite. The valence states of silver, nickel, oxygen, carbon, and nitrogen were analyzed using X-ray photoelectron spectroscopy (XPS), while energy-dispersive X-ray analysis (EDX) and morphological investigations revealed the elemental distribution and nano-structured particles, respectively. The electrocatalyst-modified electrode properties and electrochemical sensing performances were evaluated using different voltammetric and spectroscopic techniques. The Ag/NiO/g-CN composite, exhibiting a large active surface area, excellent conductivity, and synergistic interaction, proved to be a suitable electrode material for electrochemical sensor applications. The sensor demonstrated a detection limit of 0.9 nM and a broad linear range of 0.004-366.8 μM. Electrochemical investigations further highlighted the sensor's excellent reproducibility, repeatability, fast response, and functional stability. The constructed sensor also exhibited outstanding selectivity against potential interferents and demonstrated its practical applicability by successfully detecting vanillin in spiked food samples.

The influence of thermal tempering on the fracture resistance, surface microstructure, elemental surface composition, and phase analysis of four heat-pressed lithia-based glass ceramic crowns

BackgroundThis in-vitro study aimed to evaluate the impact of thermal tempering and ceramic type on the fracture resistance, surface microstructure, elemental surface composition and phase analysis of four heat-pressed glass ceramics.MethodsA total of 84 glass-ceramic crowns were pressed and randomly allocated into four equal groups (n = 21) according to the ceramic type: Group (E): IPS e.max Press, Group (L): GC initial LiSi Press, Group (C): Celtra Press and Group (A): VITA Ambria. The crowns of each group were equally allocated into three subgroups (n = 7) regarding the subsequent thermal tempering temperature. Subgroup (T0): No tempering. Subgroup (T1): Tempering at 9% below pressing temperature. Subgroup (T2): Tempering at 5% below pressing temperature. Samples were tested for fracture resistance using a universal testing machine. A scanning electron microscope, X-ray diffraction, and Energy Dispersive x-ray analysis were utilized to disclose the microstructural features.ResultsWhen there is no tempering, IPS e.max press showed a significant elevated fracture resistance (P-value = 0.002). There was an insignificant difference between other ceramics. While with tempering (T2) as well as (T1), Lisi press (L) showed a significant elevated fracture resistance. There was an insignificant difference between other ceramics (P-value = 0.004).ConclusionsIncorporation of zirconia oxide into the lithium disilicate glass matrix did not show improvement in the fracture resistance. Thermal tempering procedure had significant effect on fracture resistance. Thermal tempering technique had no influence the elemental surface composition and phase analysis yet T2 samples showed changes in crystal size and orientation.

Synthesis of novel magnesium ferrite Schiff base chitosan nanocomposite for efficient removal of pb(II) ions from aqueous media

In this study, a novel MgFe2O4-Schiff base-chitosan nanocomposite was synthesized using a straightforward crosslinking method. The synthesis involved integrating MgFe2O4 nanoparticles with modified chitosan through a Schiff base formed by the reaction between terephthalaldehyde and aminopyrazine. A comprehensive characterization was performed, including X-ray diffraction analysis, which verified the crystalline structure and the successful incorporation of MgFe2O nanoparticles into the chitosan-Schiff base matrix. Scanning electron microscopy revealed a distinct surface morphology, characterized by a rough, non-uniform alignment resulting from the strong interactions between the nanoparticles and the Schiff base-chitosan matrix. Additionally, energy-dispersive X-ray analysis verified the elemental composition of the nanocomposite, revealing distinct peaks corresponding to carbon, nitrogen, oxygen, magnesium, and iron. The nanocomposite exhibited outstanding performance as a nanoadsorbent for the efficient removal of Pb(II) ions from aqueous media through electrostatic attraction and complexation mechanisms, achieving a maximum adsorption capacity of 290.7 mg g-1. The adsorption process was determined to be spontaneous, endothermic, and chemically driven, aligning well with the Langmuir isotherm model and pseudo-second-order kinetics. The optimal conditions for maximum Pb(II) ions removal were determined to be a pH of 5.5, a contact time of 100 min, and a temperature of 328 K. Furthermore, the nanocomposite demonstrated excellent recyclability, retaining over 94.8% of its initial removal efficiency after five consecutive adsorption-desorption cycles. This study highlights the nanocomposite’s potential as an eco-friendly, cost-effective, and highly efficient material for practical applications in water treatment, addressing the urgent need for sustainable solutions to heavy metal contamination.

Novel Ni/SBA-15 Catalyst Pellets for Tar Catalytic Cracking in a Dried Sewage Sludge Pyrolysis Pilot Plant

Novel Ni/SBA-15 catalysts were synthesised and their activity in the dry reforming of methane process was assessed. These materials were prepared into extrudates shaped like pellets and tested in a pyrolysis pilot plant fitted with a catalytic reactor for sewage sludge pyrolysis tar removal. The Ni/SBA-15 catalyst pellets remained highly active and stable throughout the test’s duration, converting 100% tar in the hot gas to smaller non-condensable gases, thereby increasing the pyrolysis gas fraction and eliminating the problematic tar in the vapour stream. Catalyst characterisation with Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray (EDX) analysis, Transmission Electron Microscopy (TEM), and Thermogravimetric Analysis (TGA) confirmed that both the Ni/SBA-15-powered catalyst and the pellets were resistant to sintering and carbon deposition and remained highly active even with relatively high-level sulphur in the feed stream. The Ni/SBA-15 catalyst extrudates were prepared by mixing the powdered catalyst with varied amounts of colloidal silica binder and fixed amounts of methyl cellulose and water. The highest mechanical strength of the extrudates was determined to be of those obtained with 36% of the inorganic binder. The physical properties and catalytic activity of Ni/SBA-15 pellets with 36% colloidal silica were compared with the original powdered Ni/SBA-15 catalyst to assess the binder inhibitory effect, if any. The results confirmed that colloidal silica binder did not inhibit the desired catalyst properties and performance in the reaction. Instead, enhanced catalytic performance was observed.

Enhancing corrosion resistance of mild steel in acid pickling bath: An investigation of new quinazoline derivatives by synthesis, electrochemical analysis EFM, surface analysis, AFM, DFT and molecular dynamics simulation

The current study examines the ability of two novel heterocyclic Quinazoline derivatives, 2-(4-bromophenyl)-3-phenyl-2,3-dihydroquinazolin-4(1H)-one (DHQ-4-Br) and 2-(4-hydroxy-3-methoxyphenyl)-3-phenyl-2,3-dihydroquinazolin-4(1H)-one (DHQ-3-OMe-4-OH) to adsorb and protect mild steel against corrosion in a molar solution of hydrochloric acid (HCL). The two materials were identified using nuclear magnetic resonance (NMR) spectroscopy and the experimental investigation employed potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), and impedance spectroscopy (EIS). The findings demonstrated that DHQ-4-Br and DHQ-3-OMe-4-OH exhibit increasing inhibitory effectiveness as the concentration of the inhibitors increases. Polarization test results suggest that the two inhibitors exhibited mixed-type behavior. The inhibitory efficiency of DHQ-4-Br and DHQ-3-OMe-4-OH was 94.65 % and 83.94 % respectively. In addition, the Langmuir adsorption model was employed better to understand the adsorption process of the two compounds. The existence of a barrier layer surrounding the SM was demonstrated using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), and atomic force microscopy (AFM). The results of the density functional theory (DFT) show that the inhibitors that can take electrons have the strongest interactions with the iron surface.

A Comparative Study of Nanoconjugates of a Synthetic and a Natural Drug Against T2DM-Induced Cognitive Dysfunction.

Type II Diabetes Mellitus (T2DM) is one of the risk factors for the development of dementia leading to cognitive dysfunctions. The present study evaluates the efficacy of a synthetic drug (Vildagliptin, VLD) and a natural glycosidic compound (Hesperidin, HSP) against T2DM-induced cognitive dysfunction in rats. The drugs were conjugated with metal nanoparticles like gold (Au) and selenium (Se) to enhance their efficacy. The synthesis of the monometallic and bimetallic nanoparticles of VLD and HSP was established via the turkevich method and characterised by different spectroscopical techniques like UV (Ultraviolet)-visible, FTIR (Fourier Transform Infrared Spectroscopy), zeta potential, particle size, HR-TEM (High Resolution Transmission Electron Microscopy), SAED (Selected Area Electron Diffraction) and SEM-EDX (Scanning Electron Microscopy with Energy Dispersive X-ray Analysis). Both Streptozotocin (STZ) of 65mg/kg (Group I-X) and Alloxan (ALX) of 150mg/kg (Group I-X) were injected into 120 Wistar rats to induce cognitive dysfunction. After the induction, the BGL levels were evaluated and rats with BGL > 250mg/dl were used in the study. Then the test drug and nanoformulations were administered for 21days. Neurobehavioral assessment, antioxidant studies, and estimation of AChE (acetylcholinesterase) and nitrite levels were done. The VLD and HSP with its nanoconjugates significantly attenuated the effect of STZ and ALX by improving the memory and learning function in Y-maze, radial arm maze (RAM), and elevated plus maze (EPM), increased antioxidant levels of SOD (superoxide dismutase), CAT (catalase), and GSH (glutathione); decreased lipid peroxidation and reduced the AChE and nitrite levels in the rat brain. The bimetallic nanoconjugates of both VLD and HSP were more effective than the monometallic forms of VLD and HSP. However, VLD and its nanoconjugates exhibited better neuroprotective activity than HSP and its nanoconjugates in STZ and ALX animal models. VLD and its nanoformulations were more effective against long-term memory than HSP and its nanoconjugates. Both VLD and HSP may be a potential lead for cognitive and neurodegenerative diseases.

New Nanobioceramics Based on Hydroxyapatite for Biomedical Applications: Stability and Properties

In this work, we report for the first time the development and complex characterization of new bioceramics based on hydroxyapatite (HAp, Ca10(PO4)6(OH)2). On the other hand, the lyophilization process was used for the first time in this research. The samples were obtained by a modified coprecipitation method and were dried by lyophilization (lyophilized hydroxyapatite (HApLF) and lyophilized zinc-doped hydroxyapatite (5ZnHApLF)). Valuable information about the HApLF and 5ZnHApLF stability was obtained through nondestructive ultrasound measurements. The X-ray diffraction (XRD) studies revealed the phase and the effects of the incorporation of Zn ions into the HAp structure. The chemical composition of the samples was evaluated by energy dispersive X-ray analysis (EDS) and X-ray photoelectron spectroscopy (XPS). Information about the functional groups present in the HApLF and 5ZnHApLF was obtained using Fourier Transform Infrared Spectroscopy (FTIR) studies. The morphology of HApLF and 5ZnHApLF pellets was observed by scanning electron microscopy (SEM). The surface topography of HApLF and 5ZnHApLF pellets was studied with the aid of atomic force microscopy (AFM). Details regarding the roughness of the samples were also obtained using AFM topographies and SEM images. A complementary study was also carried out on a larger analysis surface using a Scanning Acoustic Microscope (SAM). The SAM was used for the first time to analyze the surface of HAp and 5ZnHAp pellets. The biological properties of the HApLF and 5ZnHApLF pellets was investigated with the aid of MG63 and human gingival fibroblasts (HGF-1) cell lines. The results of the cell viability assay highlighted that both the HApLF and 5ZnHApLF pellets exhibited good biological activity. Moreover, SEM and AFM studies were conducted in order to emphasize the development of MG63 and HGF-1 cells on the pellet’s surface. Both SEM and AFM images depicted that the pellets’ surface favored the cell attachment and development of MG63 and HGF-1 cells. Furthermore, the antimicrobial properties of the HApLF and 5ZnHApLF were evaluated against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, and Candida albicans ATCC 10231. The results of the antimicrobial assays highlighted that the 5ZnHApLF exhibited a strong antimicrobial activity against the tested microbial strains. The results of the biological assays suggested that the samples show great potential for being used in the development of novel materials for biomedical applications.

Green synthesis of highly luminous lemon juice-based carbon dots for antimicrobial assessment and fingerprint detection

Abstract Carbon dots are regarded as a brand new class of nanostructures in the carbonaceous family that have piqued the curiosity of researchers in a wide range of bio applications. This work focuses on the synthesis and characterization of carbon dots, as well as their latent fingerprint detection and antibacterial/antifungal capabilities. Highly luminous carbon dots were prepared by optimizing simple hydrothermal carbonization settings at 180 °C for 12 h using lemon juice as a raw precursor. The resulting product was examined using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffractometery, and ultraviolet–visible spectrophotometer. The as-prepared carbon dots were found to be extremely bright when excited under ultraviolet light (λ = 365 nm). The presence of carbon and oxygen functionalities on the surface of the carbon dots was revealed by infrared spectrocopy. The diffraction pattern confirmed the amorphous structure of the carbon dots, with an average size of 7 nm determined using the Scherrer equation. The surface morphology analysis revealed that the carbon dots exhibited an aggregated form with irregular spherical shapes. The chemical structure examination validated the elemental makeup of the prepared lemon juice-based carbon dots. The detection of latent fingerprints on carbon dots under ultraviolet light yielded positive results. In addition, the obtained carbon dots displayed antifungal and antibacterial activity against tested pathogenic fungal and bacterial strains.

Physical, Chemical, and Mechanical Characterization of Coated Date Palm Leaf Fiber from the Middle Region of Iraq for Potential in Civil Engineering Application

Date palm leaf fibers are suitable for engineering applications due to their availability, inexpensiveness, and ecofriendliness. However, there is a risk of biodegradation in the long term. This paper explores date palm leaf fiiber (DPL) properties and the protection of the fibers from biodegradation to enhance their lifespan. To this end, two coating materials (bitumen and polyurethane) were used separately. Physical and mechanical tests were conducted to determine the most effective material to coat the DPL fibers. To comprehensively assess the performance of the coated fibers, their morphology was examined via microstructure analysis using scanning electron microscopy (SEM) and energy dispersive X-ray analyses (EDX) tests. This analysis encompasses their material properties, chemical composition, water absorption, and degradation, providing a thorough understanding of the protective coatings’ impact on the DPL fibers. The tensile strength test results revealed that the maximum tensile strength of the bitumen coated date palm fiber (DPLB) is 7.4 MPa. The tensile strength is two times greater than the polyurethane coated date palm leaf fiber (DPLP) and untreated date palm leaf fiber (UDPL). The results of the degradation test revealed that the weight loss percentage is equal to 45.5 and 25 in the case of the UDPL and DPLP fibers, and no loss in weight in the case of the DPLB fiber. Out of all the test results, bitumen is considered the best due to its ability to resist the attack of chlorides and sulfate ionspresent in groundwater on top of being cheap, simple, and efficient.

Influence of elevated temperature exposure on the residual compressive strength and radiation shielding efficiency of ordinary concrete incorporating granodiorite and ceramic powders

This research investigates the potential of utilizing types of construction waste as partial cement replacements within concrete formulations. Notably, granodiorite and ceramic powders were introduced at varying substitution ratios. The impact of these waste materials on the compressive strength and radiation shielding effectiveness of traditional concrete was evaluated under both ambient and elevated temperature conditions. Additionally, several microstructural tests like X-ray diffraction (XRD), Thermogravimetric analysis (TGA), and Energy dispersive X-ray (EDX) were conducted to assess the influence of using the optimal replacement ratios of the investigated waste powders on the studied properties of concrete. Results revealed a substantial improvement in the investigated properties of the concrete. Remarkably, a 7% substitution with waste granodiorite powder (WGDP) yielded the optimal mix for compressive strength, exhibiting increases of 24.7%, 26.1%, 22%, and 28% at room temperature, 400 °C, 600 °C, and 800 °C, respectively. Likewise, a 7% replacement with waste ceramic powder (WCP) exhibited quantifiable improvements in compressive strength, with approximately 23.1%, 23.5%, 25.6%, and 32.6% at room temperature, 400 °C, 600 °C, and 800 °C, respectively. For microstructure analysis, XRD analysis confirmed enhanced pozzolanic activity with reduced portlandite and increased calcium silicate hydrate (CSH) formation for the optimal WGDP and WCP mixes compared to the control mix. TGA analysis revealed higher CSH decomposition in modified mixes, indicating greater pozzolanic reaction. Furthermore, density and EDX analyses showed denser microstructures in waste powders-incorporated mixes due to finer particle packing and secondary hydration effect. The radiation shielding investigation show that the optimum WCP mix (C7) enhances the attenuation capability of concrete. The optimum WGP mix (GD7) also contributes positively to attenuation, though to a lesser extent than C7. Ordinary concrete (CO) exhibits the lowest LAC, indicating its baseline performance in linear attenuation. Thus, the studied CM-concrete samples provide the best protection against fast neutrons which pave the way for the utilization of industrial waste, especially ceramic and granodiorite waste, in enhancing the properties of concrete towards radiation shielding against gamma rays and neutrons.

Fabrication of Cu: ZnO thin film sensor for ethanol vapor detection

For a long time, metal oxide semiconductor (MOS) based gas sensors have been widely used in domestic, commercial, and industrial sectors to detect harmful gases. The performance of such sensors is significantly enhanced by appropriate doping of suitable materials into MOS such as ZnO and SnO2. This work showcases the design, analysis, and use of a Cu-doped ZnO (Cu: ZnO) film tailored for detecting traces of ethanol vapor at lower temperatures. Herein, various Cu: ZnO films have been fabricated on glass substrates using a spin coater followed by annealing at 600 for 1 hour in a muffle furnace. So-prepared samples have been characterized using X-ray diffraction, Energy Dispersive Analysis X-ray (EDAX), UV-visible spectrophotometer, and Scanning Electron Microscopy (SEM). The XRD analysis showed a polycrystalline nature with preferred orientation along (100) and (002) crystal planes. The morphology study showed their porous and granular surface structure. These films' elemental analysis demonstrated the good incorporation of Cu into the ZnO matrix. The UV-visible results showed a significant decrease in the band gap from 3.28 eV for undoped ZnO to 3.20 eV for Cu: ZnO films. Ultimately, as-prepared Cu: ZnO thin films were used for sensing ethanol vapor at temperatures ranging from 100 to 300 . The result showed a maximum sensitivity of 70.60 at a reduced temperature of 140 at 4% Cu: ZnO thin, which implies that Cu: ZnO is suitable for developing the gas sensors for upcoming future generations.

Microstructure Refinement or Increased Copper Solubility: Factors That Contribute to the Pitting Corrosion Tendency in Aluminum–Copper Alloys

Aluminum–copper alloys are commonly used in the aerospace industry due to their low density and high strength. Pitting corrosion is the major problem of Al-Cu alloys due to the presence of largely separated electrochemical potential difference phases. Microstructure refinement and phase homogenization of the alloys are believed to be the factors that contribute to decreasing the galvanic coupling between phases, hence decreasing the pitting tendency. In this work, we investigate whether microstructure refinement is the only factor that contributes to pitting or whether some other factors are involved in the pitting tendency. The investigation was conducted on two frequently used aerospace aluminum–copper alloys, Al-2024 T3 and Al-2014 T6. The surface refinement was conducted by laser surface melting, and microstructure characterization was conducted by scanning electron microscopy with an energy-dispersive X-ray analysis. Phase identification before and after the laser surface melting was conducted by X-ray diffraction, while pitting tendency was measured by a polarization test in 1 molar sodium chloride solution. These experimental results revealed that the enrichment of copper in the α-matrix phase was the major contributing factor in pitting as compared to the largely believed microstructural phase refinement.

Insight into unusual complex thermodynamical behaviour of citric acid and ethanolamine solution

Inverse freezing fluids (IFF) are the new field of science that thermodynamically acts opposite to conventional fluids. These IFFs are novel artificial materials that work as typical thermal metamaterials. This paper reports the IFF phenomenon with basic chemicals such as citric acid and ethanolamine subjected to different conditions. The amine molecule within the precursor compound is crucial in attaining this phenomenon. Its respective inter and intramolecular ‘hydrogen’ atoms remain the key reason for this effect. Results of rheometry, Raman, proton nuclear magnetic resonance (1HNMR), photoluminescence (PL) spectroscopy, and thermogravimetric analysis (TGA) of this fluid confirmed this phenomena, collectively. Experimental findings confirm the reversible phase transformation which is contrary to the conventional fluids. It will open the interest in finding new thermal metamaterials. This study can be considered the first attempt at synthesizing IFFs through a new preparation method and analysed in detail. Many challenges were faced during synthesis and characterizations, so this study will help to resolve the complexity in this domain. Further, the sample was sintered and found to be multi-layered reduced graphene oxide (rGO) powder. This rGO sample’s structural, chemical nature, and morphology are studied through x-ray diffraction (XRD), Fourier transformed infra-red (FTIR), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope imaging and energy dispersive analysis of x-rays (EDAX). XRD pattern confirmed the presence of the main peak at 26° (2θ) corresponding to the basal reflection (002) of rGO phase. It was further evidenced by its D and G bands of Raman spectra at 1357 and 1574 cm−1, respectively. FTIR analysis also revealed a reduced OH- band whereas EDAX analysis confirms the purity of rGO by the presence of carbon and oxygen peaks only. Multilayer formation of rGO was confirmed by SEM and TEM observations and found that the measured thickness of the sheet was nearly 1 nm.Graphical

Redescription and molecular analysis of Corynosoma pseudohamanni Zdzitowiecki, 1984 (Acanthocephala: Polymorphidae) juveniles from Notothenia coriiceps Richardson in the water area of Argentine Islands, West Antarctica.

Corynosoma pseudohamanni Zdzitowiecki, 1984 (Polymorphidae) was described from the intestinal tract of 5 species of seals including the type and main host, the Weddell seal Leptonycotes weddellii (Lesson) in the South Shetlands, West Antarctica. Notothenia coriiceps was the primary paratenic host of 14 fish hosts reported in the original description. We describe excysted juveniles from the body cavity of the major paratenic host, Notothenia coriiceps Richardson collected off Galindez Island, Argentine Islands, West Antarctica for the first time. The original description was not "based on material collected from the final hosts (seals) and paratenic hosts (fish)" as stated since no description of juveniles was given then. Our excysted juveniles were generally smaller than reported adults and many of the other measurements were comparable to those of the adults in the original description. We added many of the incomplete measurements of adults in the original description especially those of the underdeveloped reproductive structures. We compared our morphometric description with the only other one available for juveniles collected from three paratenic fish hosts from Prince Gustav Channel, Antarctica. We have added informative optical microscopy images and SEM images of internal and external structures, previously missed in the original description. Energy Dispersive X-ray analysis revealed the highest levels of calcium in all hooks and hook roots compared to sulfur and phosphorus. We also provide a molecular characterization of the species for the first time. Newly generated sequences of the mitochondrial cytochrome c oxidase subunit 1 (mtcox1) gene from isolates of C. pseudohamanni cystacanths were compared with sequences of other acanthocephalans available in GenBank. Phylogenetic analyses based on maximum likelihood (ML) and Bayesian inference (BI) methods of the cox1 dataset placed all the species of Corynosoma in a single clade, with strong support. The mt cox1 sequences of C. pseudohamanni formed a strongly supported individual clade with the published sequences of Corynosoma nortmeri and Corynosoma magdaleni from the North Sea, Germany. We have determined the genetic diversity ofC. pseudohamanni and compare it with other Corynosoma species haplotype diversity and distribution.

Dual surrogate imprinting: an innovative strategy for the preparation of virus-selective particles.

This work involves the preparation of dual surrogate-imprinted polymers (D-MIPs) for the capture of SARS-CoV-2. To achieve this goal, an innovative and novel dual imprinting approach using carboxylated-polystyrene (PS-COOH) nanoparticles with a diameter of 100 nm and a SARS-CoV-2 Spike-derived peptide was carried out at the surface of amine-functionalized silica (PS-NH2) microspheres with a diameter of 500 nm. Firstly, PS-COOH nanoparticles with the same size and spherical shape as the SARS-CoV-2 virus were employed to form hemispherical indentations (HI) at the surface of the PS-NH2 microspheres (obtaining dummy particle-imprinted polymers, HI-MIPs). Next, a specific peptide sequence representing the Spike protein at the surface of the target virus was also used as the second template to generate specific peptide binding sites at the HI. Finally, the PS-COOH and the peptide were removed by several washing steps providing D-MIPs, comprising both dummy particle indentations (HI) and peptide binding sites. The D-MIPs and HI-MIPs were in-depth characterized via scanning electron microscopy (SEM), transmission electron microscope (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and energy dispersive X-ray analysis (EDAX). 100% rebinding efficiency was achieved for the SARS-CoV-2 peptide with D-MIPs highlighting its specificity vs. non-peptide-imprinted control polymers (HI-MIPs), which only achieved a binding efficiency of <40.5%. D-MIPs also showed higher affinity than HI-MIPs towards real SARS-CoV-2 virus. Furthermore, lower rebinding percentages for both HI-MIPs (8.5%) and D-MIPs (6.9%) were obtained when incubated with an alternative peptide (i.e., characteristic for Zika virus) indicating a successful peptide imprinting process for the target SARS-CoV-2 peptide.

Integration of p-Type PdPc and n-Type SnZnO into Hybrid Nanofibers Using Simple Chemical Route for Enhancement of Schottky Diode Efficiency

Palladium phthalocyanine (PdPc) and palladium phthalocyanine integrated with tin–zinc oxide (PdPc:SnZnO) were prepared using a simple chemical approach, and their structural and morphological properties were identified using X-ray diffraction, energy dispersive X-ray analysis, scanning electron microscopy, and transmission electron microscopy techniques. The PdPc:SnZnO nanohybrid revealed a polycrystalline structure combining n-type metal oxide SnZnO nanoparticles with p-type organic PdPc molecules. The surface morphology exhibited wrinkled nanofibers decorated with tiny spheres and had a large aspect ratio. The thin film revealed significant optical absorption within the ultraviolet and visible spectra, with narrow band gaps measured at 1.52 eV and 2.60 eV. The electronic characteristics of Al/n-Si/PdPc/Ag and Al/n-Si/PdPc:SnZnO/Ag Schottky diodes were investigated using the current–voltage dependence in both the dark conditions and under illumination. The photodiodes displayed non-ideal behavior with an ideality factor greater than unity. The hybrid diode showed considerably high rectification ratio of 899, quite a low potential barrier, substantial specific photodetectivity, and high enough quantum efficiency, found to be influenced by dopant atoms and the unique topological architecture of the nanohybrid. The capacitance/conductance–voltage dependence measurements revealed the influence of alternative current signals on trapped centers at the interface state, leading to an increase in charge carrier density.

The Effect of Silver Diamine Fluoride Combined with Potassium Iodide and Sodium Fluoride on the Remineralisation of Hydroxyapatite.

To compare remineralisation efficacy between silver diamine fluoride (SDF) combined with potassium iodide (KI) and sodium fluoride (NaF) varnish using hydroxyapatite (HAP) artificial white spot lesions (AWSLs) demineralisation model. A total of 25 HAP disks was randomly divided into five groups (n = 5): baseline, AWSLs, deionized water (DW), SDF-KI or F-varnish. After AWSLs were developed, the specimen was treated with either deionized water, SDF-KI or F-varnish. These specimens were then subjected to pH-cycling for 7 days. The remineralisation potential was assessed by measuring changes in Vickers hardness (VHN). Morphological and compositional analyses were conducted using scanning electron microscopy (SEM), energy dispersive x-ray (EDX), x-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). Ion-selective electrodes (ISE) were utilised to measure calcium and fluoride release. SDF-KI treatment demonstrated statistically significant remineralisation potential in restoring VHN values vs baseline levels (p 0.001). SEM, EDX, and XRD analyses confirmed the mineral deposits to indicate remineralisation. The uptake of calcium was higher in SDF-KI than in F-varnish (p = 0.011). The fluorapatite (FAP) and fluoride-substituted apatite formation were validated by FTIR and XRD analyses. SDF-KI and F-varnish applications are both effective in promoting remineralisation on HAP disks. The application of SDF-KI affected the physicochemical and mechanical properties of demineralised HAP. The SDF-KI showed more formation of fluoride-substituted apatite and is effective in the hardening of demineralised HAP.

Antibacterial and photocatalytic activities of biosynthesized zinc oxide nanoparticle using novel plant P. macrosolen L. leaf extract

In this study, ZnO nanoparticles were produced by an easy and cost effective approach using P. macrosolen L. leaf extract and zinc chloride as Zn ion source. The as-biosynthesized ZnO nanoparticles were analyzed by powder-X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, UV–visible spectroscopy, Focused ion beam-scanning electron microscopy (FIB-SEM) and energy dispersive X-ray (EDX) characterization techniques. The XRD result revealed the formations of ZnO-nanoparticles with hexagonal structure, spherical like shape and average crystalline size of 47 nm. The presence of flavonoids in P. macrosolen L. extracts was confirmed by phytochemical tests, indicating that flavonoids primarily acted as reducing agents during nanoparticle formation. The FTIR spectrum also revealed broad and strong peaks corresponding to –OH groups, confirming the high concentration of phenolic acids present in the extract. The energy band gap of the biosynthesized ZnO Nanoparticles, calculated using the Tauc relation, was found to be 3.0 eV, indicating the presence of a blue shift. FIB-SEM was used to analyze the microstructure and identify any aggregations. The EDX analysis revealed the presence of zinc and oxygen, with weights of 16.33% and 83.67%, respectively. The disk diffusion test was performed on solid agar plates and demonstrated that the substance is effective against E. coli bacteria as an antibacterial agent. The photocatalytic degradation rate constants of the optimized ZnO samples under visible light are approximately 0.06455 min⁻1 for MO and 0.04865 min⁻1 for TB, achieving 94.47% and 92.34% degradation of MO and TB, respectively. These rates are significantly higher compared to unmodified ZnO, which has a degradation rate of 0.0075 min⁻1. The improvement in visible-light photocatalytic performance can be attributed to the formation of ZnO nanoparticles, which arise from the matching of crystal lattices and energy bands in ZnO. ZnO Nanoparticles produce excited electrons under visible light irradiation. These excited electrons in the ZnO nanoparticles are directly transferred to the conduction band (CB), resulting in notable visible light photocatalytic performance.