Scanning Electron Microscopy Methods Research Articles

Coating of Carbon Black (CB) and Graphene Oxides (GOs) with Magnetite (Fe3O4)

Composites containing iron oxides are obtained by the co-precipitation of iron(II) and iron(III) compounds in the presence of different substrates in an alkaline environment. Newly synthesized graphene oxide (GO), reduced graphene oxide (rCO) and carbon black (CB) are used as substrates. Methods of obtaining GO–amorphous iron compound, rGO–Fe3O4, and CB–Fe3O4 composites are developed. It is determined that rGO–Fe3O4 and CB–Fe3O4 magnetic composites can be obtained at 70–75°C, while in the presence of GO, a non-magnetic composite containing an amorphous iron compound is formed under the same conditions. This composite, when heated in vacuum at 170–175°C, undergoes exfoliation, in result of which a powder composite rGO–amorphous iron compound is formed, the volume of which is 2.7 times greater than that of initial powder. Partial reduction of the formed composite takes place at 550°C and rGO–Fe3O4 is obtained. Formation of the magnetite phase is determined by XRD (X-Ray Diffraction) analysis. The structural-morphological study of the synthesized composites is carried out by the SEM (Scanning Electron Microscopy) method. Their magnetic characteristics are studied using VSM (Vibrating Sample Magnetometry) method.

In-Situ Liquid-Electrochemical X-Ray and Electron Microscopy for Multi-Modal Energy Materials Characterization

In-situ liquid cell electron and x-ray microscopy have enabled dynamic studies of electrochemical reactions in energy materials and revealed relationships between the performance, structure, and chemical composition of these material systems. Such fundamental relationships are critical to improving the performance of batteries, catalysts, and other energy materials. Growing research interest in energy materials systems has accelerated the development of in-situ liquid-electrochemical microscopy techniques into mature and robust characterization workflows using novel and versatile scientific hardware.Multiple characterization techniques or in-situ processing steps are often required to fully understand the mechanisms governing the behavior of energy materials for all relevant length scales and environmental conditions. A multi-modal workflow combining in-situ liquid-electrochemical transmission electron, X-ray synchrotron and scanning electron microscopy methods is presented. The breadth of research applications is discussed, including the study of chemical dynamics and structural changes to micron-scale LixFePO4 battery particles during lithium-ion insertion/extraction, electrocatalytic behavior of β-Co(OH)2 platelet particles, and electrochemical oxidation of copper nanoparticles under reductive electrolytic conditions. New insights into these materials systems provided by these experiments will directly inform the development of predictive models for material performance and guide improvement of material design and synthesis.New scientific hardware and method development has been critical to in-situ nano-scale liquid cell microscopy and spectroscopy of electrochemical systems. Therefore, best-practice hardware and method design and development for these in-situ liquid-electrochemical microscopy experiments are also discussed. The connections between potentiostat, holder, and on-chip leads must be carefully considered with respect to different ground potentials, and the incorporation of real bulk-scale reference electrodes in this hardware has yielded quantitatively higher fidelity data with less degradation from further electrochemical cycling. Heating the sample or illuminating with light during in-situ electrochemical data collection has begun to further expand the range of environmental conditions that can be incorporated into experiments.

A Nafion/BiVO4-COOH-MWCNTs/GCE for the sensitive determination of Cd2+ and Pb2+ by DPASV

BiVO4 was hydrothermally prepared and then ultrasonically mixed with carboxylated multiwalled carbon nanotubes (COOH-MWCNTs) to yield a BiVO4-COOH-MWCNTs composite. The composite were cast-coated on a glassy carbon electrode (GCE) to yield a BiVO4-COOH-MWCNTs/GCE, and then a Nafion solution was cast-coated on the BiVO4-COOH-MWCNTs/GCE to yield a Nafion/BiVO4-COOH-MWCNTs/GCE. The related materials and electrodes were characterized by field emission scanning electron microscopy, X-ray diffractometer and electrochemical methods. Under the optimal experimental conditions, Cd2+ and Pb2+ were analyzed by differential pulse anodic stripping voltammetry on the Nafion/BiVO4-COOH-MWCNTs/GCE, giving a linear detection range (LDR) from 10.0 nM to 2.00 μM and a limit of detection (LOD, S/N = 3) of 0.5 nM for Cd2+, as well as a LDR from 10.0 nM to 1.00 μM and a LOD of 0.9 nM for Pb2+. The Nafion/BiVO4-COOH-MWCNTs/GCE exhibited good selectivity, stability and reproducibility and returned satisfactory results of determining Cd2+ and Pb2+ in seafood samples.

Improving Tamoxifen Performance in Inducing Apoptosis and Hepatoprotection by Loading on a Dual Nanomagnetic Targeting System.

Although tamoxifen (TMX) belongs to selective estrogen receptor modulators (SERMs) and selectively binds to estrogen receptors, it affects other estrogen-producing tissues due to passive diffusion and non-differentiation of normal and cancerous cells and leads to side effects. The problems expressed about tamoxifen (TMX) encouraged us to design a new drug delivery system based on magnetic nanoparticles (MNPs) to simultaneously target two receptors on cancer cells through folic acid (FA) and hyaluronic acid (HA) groups. The mediator of binding of two targeting agents to MNPs is a polymer linker, including dopamine, polyethylene glycol, and terminal amine (DPN). Zeta potential, dynamic light scattering (DLS), and Field emission scanning electron microscopy (FESEM) methods confirmed that MNPs-DPN-HA-FA has a suitable size of ~105 nm and a surface charge of -41 mV, and therefore, it can be a suitable option for carrying TMX and increasing its solubility. The cytotoxic test showed that the highest concentration of MNPs-DPN-HA-FA-TMX decreased cell viability to about 11% after 72 h of exposure compared to the control. While the protective effect of modified MNPs on normal cells was evident, unlike tamoxifen, the survival rate of liver cells, even after 180 min of treatment, was not significantly different from the control group. The protective effect of MNPs was also confirmed by examining the amount of malondialdehyde, and no significant difference was observed in the amount of lipid peroxidation caused by modified MNPs compared to the control. Flow cytometry proved that TMX can induce apoptosis by targeting MNPs. Real-time PCR showed that the modified MNPs activated the intrinsic and extrinsic mitochondrial pathways of apoptosis, so the Bak1/Bclx ratio for MNPs-DPN-HA-FA-TMX and free TMX was 70.82 and 0.38, respectively. Also, the expression of the caspase-3 gene increased 430 times compared to the control. On the other hand, only TNF gene expression, which is responsible for metastasis in some tumors, was decreased by both free TMX and MNPs-DPN-HA-FA-TMX. Finally, molecular docking proved that MNPs-DPN-HA-FA-TMX could provide a very stable interaction with both CD44 and folate receptors, induce apoptosis in cancer cells, and reduce hepatotoxicity. All the results showed that MNPs-DPN-HA-FA-TMX can show good affinity to cancer cells using targeting agents and induce apoptosis in metastatic breast ductal carcinoma T-47D cell lines. Also, the protective effects of MNPs on hepatocytes are quite evident, and they can reduce the side effects of TMX.

Understanding of the correlation of structural and microwave dielectric performance of (1-x)MgTiO3 - xCaTiO3 ceramics for dielectric resonator antenna applications

In this article, the effect of CaTiO3 on the structural and microwave dielectric characteristics of MgTiO3 has been discussed. The (1-x)MgTiO3 - xCaTiO3 (abbreviated as (1-x)MT- xCT) for x = 0.025, 0.05, 0.075, 0.1 ceramics have been developed using a solid-state reaction route. The structural as well as morphological characteristics of specimens have been observed by employing X-ray diffraction and scanning electron microscope methods. The Rietveld refinement technique of X-ray diffraction data have been conducted for the refinement of structural phases. It suggests that two crystallographic phases have been present in all materials. The SEM images display dense well-identified grains of (1-x)MT - xCT (for x = 0.025–0.1) ceramics. The Raman spectroscopy method has been employed to detect the symmetry of ceramics and modes of vibration of the materials. The microwave dielectric characteristics like dielectric permittivity (εr), loss (tanδ), quality factor (Q×f), and temperature coefficient at resonant frequency (τf) of (1-x)MT - xCT (for x = 0.025–0.1) ceramics have been thoroughly investigated. The bond strength, bond valency, bond energy, and tolerance factor of (1-x)MT - xCT (for x = 0.025–0.1) materials have been evaluated and their relation with microwave dielectric characteristics has been discussed. The (1-x)MT - xCT (for x = 0.025–0.1) ceramics show excellent dielectric properties with near to zero τf. In addition, DRAs have been designed with (1-x)MT - xCT (for x = 0.025–0.1) materials as dielectric resonators and various antenna properties have been studied with the help of HFSS software. This work suggests that (1-x)MT - xCT for (x=0.05) material can be a promising candidate for DRA applications working in the C band.

Electron Beam Interaction with Carbon Nanotubes in Scanning Electron Microscope: Mechanisms and Applications

AbstractA comprehensive understanding of the interaction between electron beams and carbon nanotubes (CNTs) in scanning electron microscope (SEM) can be challenging due to the complex surface charging behavior and various nanostructures formed by CNTs. Herein, an overview of the challenges and potential solutions are provided for achieving high‐resolution imaging of nanomaterials, such as CNTs, in SEM systems. First, imaging mechanisms of CNTs on conducting, insulating, and hybrid substrates are summarized, with morphology, material type, and charging effect covered. Second, measuring the conductivity, bandgap, and diameter of a CNT by SEM method is introduced. Finally, the utilization of super‐aligned CNT (SACNT) films for observing insulators and vertically aligned CNT arrays (VACNTAs) as electron blackbodies are discussed separately. New techniques for imaging and characterizing nanostructures will ultimately lead to the advancement of CNT‐based technologies.

Laser synthesis of oxide nanoparticles with controlled gas condensation

In this work, the oxide nanopowders of Al2O3, ZrO2, Y2O3, Gd2O3, CeO2, and SiO2 were synthesized by CW CO2 laser vaporization technique with controlled gas condensation in an inert atmosphere. Methods for controlling the size of the resulting nanoparticles by adjusting the gas composition and pressure during the vaporization process have been demonstrated. The potential for producing ultrasmall oxide nanoparticles with dimensions less than 5 nm has been shown. The size distribution of nanoparticles taken from different parts of the evaporation-condensation tract was studied using scanning (SEM) and transmission (TEM) electron microscopy methods. The effect of synthesis conditions (pressure and composition of the inert gas) on characteristics of the nanoparticles is discussed. Using a wide class of simple oxides as the example, it is shown that the powders synthesized by the laser method consist of three types of particles: target spherical particles with a diameter of 3–20 nm (more than 98%), larger spherical particles with a diameter of 50–200 nm, and shapeless large particles with sizes more than 200 nm. The possibility of separating large particles from the main particles using the original labyrinth system for gas pumping is shown. The obtained particles with controlled sizes can be effectively used in various applications, in particular, for the preparation of catalysts and adsorbents.

Application of digital image correlation for in-situ deformation studies using transmission electron microscopy

Digital Image correlation (DIC) is routinely applied using optical and scanning electron microscopy methods to map local strains during deformation. In this letter, we report its use for in-situ TEM imaged deformation evolution for a nanocrystalline metal. Since transmitted electrons give rise to complex contrast conditions, with such contrast associated with the mechanisms of deformation, one can track these changes if particular care is done in image analysis and interpretation. We describe these methodologies to enable this correlation through frame averaging. Using these collective correlation conditions, we found that the average DIC strain matches well with the far field strain values yielding increased confidence in its application. Through the utilization of DIC in the TEM, nanoscale deformation mechanisms can be further elucidated because of the increased spatial resolution offered by TEM.

In vitro and in silico studies of the inclusion complexation of 8-bromobaicalein with β-cyclodextrins

Baicalein, a flavone derived from Scutellaria baicalensis Georgi, exhibits potent anti-inflammatory, antiviral, and anticancer properties. Its derivative, known as 8-bromobaicalein (BB), has been found to have strong cytotoxic properties against MCF-7 human breast cancer cells. However, its limited solubility in water has hindered its potential for wider applications. To address this issue, we investigated the use of cyclodextrins specifically βCD, 2,6-di-O-methyl-β-cyclodextrin (DMβCD), and hydroxypropyl-β-cyclodextrin (HPβCD) to improve the solubility of BB through inclusion complexation. During 250 ns molecular dynamics simulations, it was found that BB can form inclusion complexes with all βCDs. These complexes exhibit two distinct orientations: chromone group insertion (C-form) and phenyl group insertion (P-form). The formation of these complexes is primarily driven by van der Waals interactions. DMβCD has the highest number of atom contacts with BB and the lowest solvent accessibility in the hydrophobic cavity. These results coincide with the highest binding affinity from the MM/GBSA-based free energy calculation method. Experimental phase solubility diagrams revealed a 1:1 stoichiometric ratio (AL type) between BB and βCDs, in which BB/DMβCD showed the highest stability. The formation of inclusion complexes was confirmed by differential scanning calorimetry and scanning electron microscope methods. Additionally, the BB/DMβCD inclusion complex demonstrated significantly higher anticancer activity against MCF-7 human breast cancer cells compared to BB alone. These findings underscore the potential of DMβCD for formulating BB in pharmaceutical and medical applications.

Endohelminth diversity in the invasive Clarias gariepinus (Burchell, 1822) from two freshwater lakes: Naivasha and Ol'Bolossat, Kenya.

Fish parasitology contributes to our understanding of the potential risks posed by diverse groups of parasitic organisms on fish stocks in either wild and culture systems. This study was conducted in May 2023 and aimed at assessing the diversity of endohelminths in the invasive North African catfish Clarias gariepinus (Burchell, 1822) obtained from two freshwater lakes, Naivasha and Ol'Bolossat, in Kenya. Parasitological examination of 66 and 35 fish samples collected from the two lakes respectively was achieved using light and scanning electron microscopy methods. Results revealed endohelminth diversity broadly classified as four digeneans, two nematodes, and one cestode. Seven taxa of endohelminths were found in C. gariepinus samples, but only four of these taxa could be identified up to the species level. Six of the taxa (Diplostomum sp., Tylodelphys mashonense, Plagiorchioidea sp., Paracamallanus cyathopharynx, Contracaecum sp., and Tetracampos ciliotheca) were common in samples from the two lakes. Glossidium pedatum only occurred in samples from Lake Ol'Bolossat. Parasite prevalence ranged from 8.6 (T. mashonense) to 100% (Diplostomum sp., T. ciliotheca, and Contracaecum sp.) and mean intensity from 1.4 (T. mashonense) to 16.9 (Diplostomum sp.). The diversity and richness indices were comparatively higher in fish samples from Lake Ol'Bolossat and attributed to the occurrence of G. pedatum in the Ol'Bolossat. However, parasitic infestation of fish samples from the two lakes depicted close similarity, both in diversity and prevalence. These findings form an important baseline data for further follow-up studies, and they suggest the need for further molecular analyses to fully describe three of the taxa only identified up to the genus level.

Scratching of metallized polymer films by Vickers indenter as a method for controlled production of SERS-active metasurfaces

The opportunities of a system of parallel microscratches drowed on a PET film metallized with silver and copper using a Vickers indenter as an active Surface-enhanced Raman spectroscopy (SERS) or Photoluminescence-enhanced surface have been investigated. It is shown that the enhancement of the SERS signal for rhodomine is proportional to the total length of microscratches in the laser spot and increases after their application due to the relaxation of the polymer backing. The results of the microscratch geometry analysis by an atomic force microscopy and scanning electron microscopy methods indicate the probability of the location of “hot points” along the “dumps” of metal along the shores of scratches, as well as on nanoroughnesses along their inner walls.© 2017 Elsevier Inc. All rights reserved.

RESISTANCE OF FERRITE-PERLITE STEEL TUBING BRANCH PIPE METAL TO DESTRUCTION IN HYDROGEN SULFIDE MEDIUM

This paper discusses the problems of resistance of the metal of the tubing branch pipe (tubing) to the process of its destruction in a medium containing hydrogen sulfide and when exposed to external forces. A 73х73 tubing nozzle made of 38G2SFA steel was selected as the material for research. The tubing fragment was destroyed during production well operation. To establish the reasons for the failure of the tubing nozzle, a visual inspection was carried out, tests were performed to assess the hardness and mechanical properties, the microstructure and microtexture of the metal were analyzed using scanning electron microscopy (SEM) methods. To analyze the nature of the distribution of introduced defects, the mutual orientation of structural components and crystallographic texture, studies were carried out by the method electron backscatter diffraction (EBSD). Studies of the suspended branch pipe, which does not have chemical protection, showed that the cause of its destruction was hydrogen sulfide stress corrosion cracking (SSCC) as a result of hydrogen embrittlement and the action of external tensile forces exceeding the yield strength of the metal. It was established that as a result of the interaction of hydrogen sulfide of the distilled product with the metal of the branch pipe, hydrogen embrittlement of the material of the branch pipe occurred. The process of hydrogen embrittlement of the fragment was proved by detecting hydrogen blisters in the metal microstructure and establishing the process of coalescence of neighboring inclusions. In addition, the results of the test to measure the hardness of the metal along the wall thickness further supported the hypothesis of hydrogen embrittlement of the tubing. EBSD analysis showed that the threaded part of the branch pipe is characterized by a small size of structural elements and an increased density of introduced defects (geometrically necessary dislocations), which are a promising site for the deposition of molecular hydrogen. It is concluded that reaching the limit concentration of molecular hydrogen reduces the binding energy of metal atoms and this process initiates the formation of pores. It has been established that the development of cracks along large-angle grain boundaries is facilitated, and small-angle and coincidence site lattice (Σ3, Σ5, Σ11 and Σ13b) grain boundaries are active barriers to crack propagation. It has been shown that by optimizing the elemental composition of steel, controlling the microstructure, crystallographic texture, as well as the type and state of grain boundaries, new pipeline steels can be produced that are more resistant to SSCC.

Application of lactobacillus casei and lactobacillus plantarum to develop dried functional apple and banana.

The goal of this research was to create dried fruits loaded with probiotic microorganisms (Lactobacillus casei and Lactobacillus plantarum). In separate bottles for each probiotic microbe, apple and banana pieces have been submerged into the impermeability solution with gentle shaking. The vacuum pressure was applied. By the conclusion of the incubation time, L. casei and L. plantarum colonies were enumerated (CFU/g). The scanning electron microscope method was applied to confirm the penetration of impregnation solutions into the intercellular spaces of fruit tissue. On day 28, the population of L. plantarum was 5 log CFU/g for apples and 5.5 log CFU/g for bananas. After storage, the number of L. casei in apples was 5 log CFU/g and 5.5 log CFU/g, respectively. L. casei was found on the surface of apple and banana tissue. After one-week, whole phenolic content of probiotic-enriched bananas and apples augmented. After storage, the antioxidant activity of all samples decreased greatly. The sensory qualities of the samples were excellent throughout storage in terms of color, quality, scent, sensitivity, chewiness, and general adequacy. As a result, dried apples and bananas infused with L. plantarum and L. casei might be a novel probiotic meal. RESEARCH HIGHLIGHTS: Dried apples and bananas infused with L. plantarum and L. casei are novel probiotic meal. After one-week, whole phenolic content of probiotic-enriched bananas and apples augmented. The sensory qualities of the samples were excellent throughout storage in terms of color, quality, scent, sensitivity, chewiness, and general adequacy.

Experimental and mechanistic investigation on the plastic anisotropic deformation behavior of α-phase titanium alloy Ti-2Al-2.5Zr

Ti-2Al-2.5Zr is widely used in piping and structural support applications, however, the rolling forming process results in anisotropic deformation during service. This behavior has implications for the manufacturing processes and structural safety assessments in engineering applications. In this study, the plastic anisotropic deformation behavior of a rolled Ti-2Al-2.5Zr plate was investigated using uniaxial tensile tests along the transverse, normal, and 45° directions. Acoustic emission, electron backscatter diffraction, and scanning electron microscopy methods were used to investigate dislocation slip and twinning mechanisms. The results indicated that different microscopic deformation mechanisms caused the significant macroscopic anisotropy of Ti-2Al-2.5Zr. The primary mechanisms involved were prismatic <a> slip, pyramidal <c+a> slip, and {10-12} extension twinning. The stress direction determined the influence of each of these mechanisms during the yielding and plastic deformation phases. Application of the visco-plastic self-consistent model established the relationship between the macroscopic mechanical responses and microscopic deformation mechanisms. It was revealed that Ti-2Al-2.5Zr achieved its optimum strength when the initial texture aligned most of the grain c-axis at angles ranging from 30° to 50° relative to the deformation direction. This finding provides a direction for the texture design of Ti-2Al-2.5Zr in engineering materials.

Separation of Damage Mechanisms in Full Forward Rod Extruded Case-Hardening Steel 16MnCrS5 Using 3D Image Segmentation.

In general, formed components are lightweight as well as highly economic and resource efficient. However, forming-induced ductile damage, which particularly affects the formation and growth of pores, has not been considered in the design of components so far. Therefore, an evaluation of forming-induced ductile damage would enable an improved design and take better advantage of the lightweight nature as it affects the static and dynamic mechanical material properties. To quantify the amount, morphology and distribution of the pores, advanced scanning electron microscopy (SEM) methods such as scanning transmission electron microscopy (STEM) and electron channeling contrast imaging (ECCI) were used. Image segmentation using a deep learning algorithm was applied to reproducibly separate the pores from inclusions such as manganese sulfide inclusions. This was achieved via layer-by-layer ablation of the case-hardened steel 16MnCrS5 (DIN 1.7139, AISI/SAE 5115) with a focused ion beam (FIB). The resulting images were reconstructed in a 3D model to gain a mechanism-based understanding beyond the previous 2D investigations.

Влияние режимов лазерной наплавки на геометрические размеры стального трека

Introduction. Laser surfacing is one of the leading trends in the field of additive technologies, which consists in layer-by-layer build of material using a laser as an energy source. To obtain a high-quality product, it is necessary to select the optimal building parameters correctly. The problem is that such optimization is necessary for all equipment, since minor differences in its characteristics can make significant changes in the parameters of layer-by-layer build. In order to determine the optimal build mode, it is enough to analyze the effect of various equipment parameters on the characteristics of single tracks. Therefore, the purpose of this work is to determine the most important parameters of laser radiation that affect the surfacing process and the optimal mode for building a single track of chromium-nickel steel. The work investigated single tracks obtained by laser surfacing of powder from austenitic chromium-nickel steel AISI 316L. The optimization factors included such characteristics as laser power, beam speed, flow rate of supplied powder and laser spot size. The wavelength of laser radiation was 1.07 μm. Research methods. To determine the quality and geometric dimensions of single tracks, the macrostructure of cross sections of specimens was studied using metallography and scanning electron microscopy methods. Results and discussion. It is established that the optimal mode for growing single tracks of steel AISI 316L is characterized by a laser radiation power of 1,250 W and a scanning speed of 25 mm/s. In this case, the optimal powder consumption rate is 12 g/min, and the laser spot size is 4.1 mm. The work shows that the powder consumption and laser spot size have the greatest influence on the coefficient of effective use of powder material. By changing it, the surfacing performance can be increased by 10–15 %.

Developing a new ethylene glycol/H2O pretreatment system to achieve efficient enzymatic hydrolysis of sugarcane bagasse cellulose and recover highly active lignin: Countercurrent extraction

Improving pretreatment efficiency is a critical premise in achieving efficient biomass conversion, and obtaining high-performance natural polymers is the guarantee of high-value conversion of biomass. In this study, a new pilot-scale continuous countercurrent pretreatment reaction unit about ethylene glycol-alkali solution was designed for pretreating sugarcane bagasse in order to achieve efficient separation of the three major components of lignocellulose when expanding the scale of pretreatment, reduce lignin deposition on the fiber surface, and obtain highly active lignin and excellent enzymatic hydrolysis efficiency of cellulose. X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), brunauer-emmett-teller (BET) and scanning electron microscope (SEM) methods are used to analyze the structural properties of sugarcane bagasse before and after pretreatment, and high-performance liquid chromatography (HPLC) is used to analyze the monosaccharide components in the enzymatic solution. In addition, the structural properties of the recovered lignin are analyzed by gel permeation chromatography (GPC), 31P NMR and 2D-HSQC-NMR methods. The results indicate that the system can gain a high cellulose recovery of 92.99% along with a lignin removal of 95.33%, and recovered lignin has low lignin carbohydrate complexes, low condensation, and rich in phenolic hydroxyl groups for 1.95 mmol/g. Meanwhile, the countercurrent pretreatment system can effectively reduce the deposition of lignin on the cellulose surface, which is evidently superior to the non-countercurrent pretreatment and facilitates the efficiency of enzymatic saccharification of substrate, achieving a high glucose yield of 99% as well as a total sugar yield of 91.11%. The method efficiently separates biomass in a green manner, and solid residues are easily hydrolyzed, showing potential for industrial-scale production.

Comparison of mechanical stability and morphology study between tree fibres and shrub fibres reinforced epoxy bio-composites

The material properties of bio-composites reinforced with natural fibers from shrubs (Tinospora cordifolia and Ipomoea staphylina) and trees (Morinda citrifolia and Tamarindus indica) are investigated in this study. Evaluation of these bio-composites’ mechanical characteristics and microscopic structure was the main goal, with a comparison of the efficacy of shrub and tree fibers for use in future automobile structural parts, airplane interiors, and consumer goods in mind. Because of their unequal distribution within the polymer matrix, the characteristics of natural fibers and composite fibers made of epoxy resin were found to be insufficient. Utilizing an unprocessed natural fiber ratio of 50 % fiber-to-resin, the composites were fabricated by hand layup technique. The findings showed that the epoxy composite enhanced with Tamarindus indica fibers (TIF) demonstrated outstanding mechanical properties, achieving a tensile strength of 8.15 MPa and compression strength of up to 5.89 kN. The compositions of the composites were analyzed using scanning electron microscopy (SEM) methods.

The effect of fish collagen on the silver nanoparticles sizes and shapes using modified microwave-assisted green synthesis method and their antibacterial activities

This work aimed to produce silver nanoparticles (AgNPs) by efficient green synthesis techniques, namely rapid green synthesis and modified microwave-assisted green synthesis methods. The study used fish scale collagen (FsCol) as a stabilizer to assess its impact on the dimensions and configurations of AgNPs. Four samples were prepared with varying concentrations of FsCol. The synthesized AgNPs were characterized using Ultraviolet–visible (UV–vis) spectroscopy, scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction analysis (XRD), Dynamic Light Scattering (DLS), and Transmission electron microscopy (TEM) techniques. The obtained sizes are as follows: 85 ± 15 nm, 70 ± 10 nm, 50 ± 10 nm, and 28–40 nm. The UV–vis spectroscopy revealed a shift in the absorbance peaks from 400 to 446 nm. The SEM method showed a spherical form in all of the samples. The element silver was detected in the EDX examination, along with the presence of oxygen (O) and carbon (C). The FTIR analysis revealed that the peaks seen at 3307 cm−1 were attributed to the stretching of O–H bonds, while the mountain at 1638 cm−1 belonged to the extension of N–H bonds (amide A). Additionally, the band observed at 1638 cm−1 indicated the presence of CO bonds (amide I).The 2140 cm−1 and 1302 cm−1 peaks may be attributed to the C2H2 group present in the plant components and the N–H bending (Amide III), respectively. The XRD pattern indicates that the synthesis process resulted in the formation of crystalline AgNPs. The particle sizes measured using DLS were 121 nm, 96.36 nm, 82.3 nm, and 48.50 nm. The TEM approach revealed that all samples had a spherical morphology with varying sizes: 80–100 nm, 50–80 nm, 40–60 nm, and 28–42 nm. The synthesized AgNPs were tested for their antibacterial properties against the pathogenic pathogens Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus). The influence of AgNPs on bacteria was amplified as the particle size decreased, resulting in a larger inhibitory zone for the smaller particles.

Novel MAXPOWER biological antibacterial liquid for eradicating oral Helicobacter pylori

BackgroundEradication of oral Helicobacter pylori (H. pylori) not only reduces the infection rate from the transmission route but also improves the success rate of intragastric eradication. MAXPOWER Biological Bacteriostatic Liquid, developed in our previous work, is a composite biological preparation with strong antibacterial ability and unique antibacterial mechanism. The present study evaluated the efficacy of the MAXPOWER biocontrol solution on H. pylori and its success rate in eradicating oral H. pylori in clinical patients.MethodsLive-dead cell staining and hemolysis test were used to evaluate the cellular safety of MAXPOWER biocontrol solution; plate spreading, live-dead bacterial staining, and scanning electron microscopy methods were used to evaluate its antimicrobial effect against H. pylori. Transcriptomics was used to analyze the changes in H. pylori genes before and after treatment. After seven days of gavage treatment, H&E staining and mice feces were collected for 16SrDNA sequencing to evaluate the animals’ safety. Oral H. pylori-positive patients were randomized to be given a placebo and MAXPOWER Bio-Bacteriostatic Liquid gargle for seven days to evaluate the effect on oral H. pylori eradication.ResultsIn vitro tests demonstrated that this product has excellent biocompatibility and hemocompatibility and can effectively eradicate oral H. pylori. In vivo tests further showed that it has good biosafety and virtually no adverse effect on intestinal microflora. Transcriptomics analysis revealed that it kills H. pylori cells mainly by disrupting their cell membranes and metabolism. Additionally, the results of randomized controlled trials on humans disclosed that the oral H. pylori eradication rates achieved by MAXPOWER Biological Antibacterial Liquid were 71.4% and 78.9% according to the intention-to-treat and the per-protocol analysis, respectively.ConclusionMAXPOWER Biological Antibacterial Liquid is both safe and efficacious in the eradication of oral H. pylori.Trial registrationThis study was retrospectively registered in the ClinicalTrials.gov Trial Registry on 21/09/2023 (NCT06045832).