Transmittance Electron Microscopy Research Articles

Structural Characteristics and Skin Permeabilities of Bicelles Dispersed in Hydrated Deep Eutectic Solvents

The structural properties of bicelles dispersed in hydrated deep eutectic solvents (DESs) was investigated by small-angle X-ray scattering, transmittance electron microscopy, and dynamic light scattering experimentations. Subsequently, we evaluated their skin permeabilities. The results showed that bicelles can be stably dispersed in hydrated DESs and the addition of DESs can improve the skin penetration of bicelles. However, further addition of DES induced the formation of the aggregates, resulting in the decrease of its skin permeability.

Photocatalytic removal of organic dyes by titanium doped alumina nanocomposites: Using multivariate factorial and kinetics models

Hazardous containing different groups of dyes from various industries are extremely dangerous and causing unfavorably susceptible dermatitis, skin diseases, transformation, and malignant growth. To overcome the hazards caused by water pollution, eco-friendly composites (TiO2-Al2O3) of titanium oxide (TiO2) and alumina (Al2O3) were synthesized with different proportional ratios (0.25/1, 0.16/1, 0.125/1, and 0.1/1) by kneading method and characterized through X-ray diffraction, scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible (UV–Vis) spectrophotometry and high resolution transmittance electron microscopy (HR-TEM). Experimental finding showed that the sample TiO2 / Al2O3 with a molar-ratio of 0.1/1 had the higher photodegradation efficacy for malachite green and from the ratio 0.1/1, the higher photodegradation efficiency was achieved for eosin Y. The comparative studies of TiO2-Al2O3 samples were done for basic malachite green and acidic eosin Y and it was estimated that due to adsorbent, Al2O3 surface basicity it showed the highest adsorption for acidic eosin Y and hence had a higher photo degradation removal up to 90% for the eosin Y than for the basic malachite green with 80% photo degradation removal. Reaction mechanism for photodegradation were finest to define by Langmuir isotherms which trailed by pseudo-second order kinetics. The t/qt vs t plots for pseudo-second order kinetic produced high regression coefficients (R2 =0.963), which stated the adsorbate sorption's followed the pseudo second order kinetics. Thermodynamic parameters of dye degradation were calculated by the Van't Hoff equation that indicated the adsorption method was exothermic. The ΔH֯ parameters were found to be -54.44 kJ mol−1. The negative ΔH֯ recommended the exothermic biosorption process. Residuals plots for responses, interaction plots for responses and inter-contour plots were utilized to study the optimum points. Furthermore, accredited to experimental results and a reaction mechanism is planned for the photodegradation of organic dyes with TiO2-Al2O3 photocatalyst. Thus the broad band gap of inert semiconductor TiO2 can be narrower by heterogeneous coupling with Al2O3 through kneading method and showed the excellent photodegradation of organic dyes in the visible region without producing any secondary pollutant.

Cobalt hexacyanoferrate adsorbed on TiO2 nanoparticles and their modified glassy carbon electrodes for electrocatalytic oxidation and amperometric determination of hydrazine.

TiO2 nanoparticles (NPs) were prepared at low temperature by stepwise hydrolysis of TiF4 in aqueous solution at 100°C. TiO2 NPs were obtained at low temperature as small size particles. Subsequently, cobalt hexacyanoferrate (CoHCF) is adsorbed on the surface of the TiO2 NPs through the ion exchange method. This method is simple and forms TiO2/CoHCF nanocomposite. TiO2 interacts with KCo[Fe(CN)6] which leads to the formation of TiO(OH)-Co bond; this is confirmed by a shift in the XPS analysis. The prepared TiO2/CoHCF nanocomposite has been characterized by FT-IR spectrum, X-ray photoelectron spectra (XPS), scanning electron microscope (SEM), high resolution transmittance electron microscope (HRTEM) and energy dispersive X-ray pattern (EDX). The TiO2/CoHCF nanocomposite is modified by the glassy carbon electrode (GCE) as an excellent electrocatalyst for the oxidation of hydrazine and is also used for the amperometric determination of hydrazine.

Biowaste-Derived Heteroatom-Doped Porous Carbon as a Sustainable Electrocatalyst for Hydrogen Evolution Reaction

Heteroatom-doped porous carbon material (H-PCM) was synthesized using Anacardium occidentale (cashew) nut’s skin by a simple pyrolysis route. The resulting H-PCM was thoroughly characterized by various analytical techniques such as field emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray (EDX) spectroscopy, high-resolution transmittance electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy, nitrogen adsorption–desorption isotherms, X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The obtained results strongly demonstrated that the synthesized H-PCM exhibited a porous nature, continuous sponge-like and sheet-like smooth morphology, and a moderate degree of graphitization/crystallinity with oxygen-, nitrogen-, and sulfur-containing functionalities in the carbon matrix. After the structural confirmation, as-prepared H-PCM has used a sustainable electrocatalyst for hydrogen evolution reaction (HER) because the metal-free carbonaceous catalysts are one of the most promising candidates. The H-PCM showed excellent HER activities with a lowest Tafel slope of 75 mV dec−1 and durable stability in 0.5 M H2SO4 aqueous solution. Moreover, this work provides a versatile and effective strategy for designing excellent metal-free electrocatalysts from the cheapest biowaste/biomass for large-scale production of hydrogen gas through electrochemical water splitting.

Water Soluble PMPC-Derived Bright Fluorescent Nitrogen/Phosphorous-Doped Carbon Dots for Fluorescent Ink (Anti-Counterfeiting) and Cellular Multicolor Imaging.

Here, a simple one-step hydrothermal-assisted carbonization process was adopted for the preparation of nitrogen/phosphorous-doped carbon dots from a water-soluble polymer, poly 2-(methacryloyloxy)ethyl phosphorylcholine (PMPC). By the free-radical polymerization method, PMPC was synthesized using 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) and 4,4'-azobis (4-cyanovaleric acid). The water-soluble polymers, PMPC, that have nitrogen/phosphorus moieties are used to prepare carbon dots (P-CDs). The resulting P-CDs were thoroughly characterized by various analytical techniques such as field emission-scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDS), high-resolution transmittance electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible (UV-vis) spectroscopy and fluorescence spectroscopy to determine their structural and optical properties. The synthesized P-CDs displayed bright/durable fluorescence, were stable for long periods, and confirmed the enrichment of functionalities including oxygen, phosphorus, and nitrogen heteroatoms in the carbon matrix. Since the synthesized P-CDs showed bright fluorescence with excellent photostability, excitation-dependent fluorescence emission, and excellent quantum yield (23%), it has been explored as a fluorescent (security) ink for drawing and writing (anti-counterfeiting). Further, cytotoxicity study results advised for biocompatibility and thus were used for cellular multicolor imaging in nematodes. This work not only demonstrated the preparation of CDs from polymers that can be used as advanced fluorescence ink, a bioimaging agent for anti-counterfeiting, and cellular multicolor imaging candidate, but additionally prominently opened a new perspective on the bulk preparation of CDs simply and efficiently for various applications.

Silicon carbide based nanocomposite of polythiophene with high thermally stable DC electrical conduction and ethanol sensing

Here in this work, we are reporting thermally stable DC electrical conductivity of silicon carbide nanocomposite with polythiophene and its sensing behavior towards ethanol. Polythiophene (PTh) and Polythiophene/SiC (PTh/SiC) nanocomposite were synthesized by in-situ process of polymerization via oxidation route using CTAB (cetyltrimethylammonium bromide) as a surfactant and characterized by X-rays diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Transmittance electron microscopy (TEM) analysis. Stability of DC electrical conductivity of PTh and PTh/SiC nanocomposite were examined at different temperature ranges from 50 °C to 130 °C in isothermal and cyclic conditions. PTh/SiC nanocomposite showed high steadiness of DC electrical conductivity than that of PTh in different thermal ageing conditions. Sensing behavior of PTh/SiC nanocomposite towards 1 M ethanol was recognized as steady with time and reversible in cyclic process.

Stabilization of the Alkylammonium Cations in Halide Perovskite Thin Films by Water-Mediated Proton Transfer.

The development of alkylammonium lead trihalide perovskite (ALHP) photovoltaics has grown rapidly over the past decade. However, there are remaining critical challenges, such as proton defects, which can lead to the material instability of ALHPs. Although specific strategies, including the use of halide additives, have significantly reduced the defects, a fundamental understanding of the defect passivation mechanism remains elusive. Herein, an approach and mechanism for minimizing proton defects in ALHP crystals by adding ionized halides to the perovskite precursor solution are reported. This work clarifies that the ionized halides induced proton transfer from H2 O to the alkylammonium cation in the precursor solution, stabilizing the ALHP crystals. The fundamental characteristics of ALHP and its precursors are examined by X-ray diffraction, transmittance electron microscopy, in situ extended X-ray absorption fine structure, Fouriertransform NMR spectroscopy, and Fouriertransform infrared spectroscopy. The findings from this work will guide the development of highly stable ALHP crystals, enabling efficient and stable optoelectronic ALHP devices.

Extraction Optimization and Characterization of Cellulose Nanocrystals from Apricot Pomace.

Apricot pomace (AP) is lignocellulosic agro-industrial waste that could be considered a good source for cellulose-based, value-added compounds. In this study, conditions for cellulose nanocrystals' (CNCs) extraction from apricot pomace (AP) were optimized using Response Surface Methodology (RSM) based on the extraction yield, and the resulting CNC was characterized using Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Transmittance Electron Microscopy (TEM), Thermogravimetric Analysis (TGA), and X-Ray Diffraction (XRD). The maximum CNC yield (34.56%) was obtained at a sulfuric acid concentration of 9.5 M within 60 min. FTIR analysis showed that noncellulosic components were gradually removed from the pomace. A morphological analysis of the nanocrystal was performed using SEM and TEM. CNCs were in the range of 5-100 µm in diameter and appeared as individual fibers. TGA analysis of the CNC sample revealed good thermal stability around 320°C. The crystalline index (%CI) of the CNC obtained from AP was determined to be 67.2%. In conclusion, this study demonstrated that AP could be considered a sustainable source for value-added compounds such as CNCs to contribute to a circular economy.

Preparation of zirconium oxide nanoparticles from rosette concentrate using two distinct and sequential techniques: hydrothermal and fusion digestion

The preparation of zirconium dioxide nanoparticles (ZrO2-NPs) as hard ceramics was accomplished from rosette zircon concentrate through two consecutive alkaline digestion reactions. The rosette zircon concentration in the Abu Khashaba area consists mainly of zircon and monazite minerals. Using different operating conditions, the hydrothermal digestion by autoclave and the conventional alkaline fusion methods was performed upon the non-magnetic concentrate of rosette in order to complete the removal of monazite firstly and to complete the purification of zircon metal secondly. All monazite content and undesirable impurities were removed by the hydrothermal method using optimal digestion conditions such as 4 mol/L NaOH solutions, 1/6 solid to liquid, 2 h dissolving time, and a temperature of 423 K. The residual zircon (84% Zr) was subjected to complete digestion using NaOH with a zircon-to-alkali ratio of 1/1.5 and a fusion temperature of 923 K. ZrO2-NPs were synthesized using the hydrothermal technique at 473 K for 7 h. The calcined ZrO2-NPs were characterized by X-ray diffraction, scan electron microscope, and transmittance electron microscope. Purified silica was also obtained as a by-product from washing solutions of fused zircon.

Centro‐symmetric copper complex as a novel antitumor drug for therapeutic applications: Fabrication, structure, theoretical calculations, cytotoxicity, DNA binding/cleavage, and molecular docking

This study presents the fabrication and structural analysis of the newly synthesized Cu(AHC)2 complex to explore its biological functionalities such as cytotoxicity, DNA binding, and DNA cleavage. For the Cu(AHC)2 complex synthesis, the bioactive 3‐acetyl‐4‐hydroxy coumarin (AHC) has been used as a ligand. The complex has been investigated using analytical and spectroscopic techniques. The resultant data have demonstrated that the AHC is coordinated to the metal ion in a monoanionic form with bidentate through O, O donor atoms forming a square planner coordinated compound. X‐ray diffraction and transmittance electron microscope analysis have shown that Cu(AHC)2 complex has hybrid morphology of irregular nano‐sphere (5 nm) and irregular sheets arranged in the format of a cluster with crystallinity form. The Cu(AHC)2 complex has been screened for in vitro cytotoxicity against HepG‐2 cell line. If it compared with different standard drugs, copper complex, it can be said, has excellent cytotoxicity (IC50 = 6.8 μg ml−1). Furthermore, the binding properties of Cu(AHC)2 complex with herring sperm DNA has been detected via UV–Vis spectroscopy and viscosity measurements. The electronic absorption spectroscopic data have revealed that the prepared Cu(AHC)2 complex strongly binds to herring sperm DNA through intercalative mode with Kb of 0.19 × 106 M−1. Confirming previously obtained spectroscopy data, the interaction of Cu(AHC)2 complex with DNA has also been explored via molecular docking analysis. DNA cleavage study has been, moreover, carried out by agarose gel electrophoresis. The data have shown that the complex has a good ability to destroy DNA. In supporting experimental data, theoretical calculations and optimized Cu(AHC)2 complex structure have been obtained from density functional theory calculations. The calculated results are consistent with the experimental findings. In conclusion, the data discussed above may offer helpful information that helps in the design of a novel copper complex that can function as a potent pharmaceutical agent.

Characterization and Biological Studies of Synthesized Titanium Dioxide Nanoparticles from Leaf Extract of Juniperus phoenicea (L.) Growing in Taif Region, Saudi Arabia

Green synthesis of metal nanoparticles in nanosized form has acquired great interest in the area of nanomedicine as an environmentally friendly and cost-effective alternative compared to other chemical and physical methods. This study deals with the eco-friendly green synthesis of titanium dioxide nanoparticles (TiO2 NPs) utilizing Juniperus phoenicea leaf extract and their characterization. The biosynthesis of TiO2 NPs was completed in 3 h and confirmed by UV-Vis spectroscopy, a strong band at 205.4 nm distinctly revealed the formation of NPs. Transmissions electron microscopy (TEM) analysis showed the synthesized TiO2 NPs are spherical in shape, with a diameter in a range of 10–30 nm. The XRD major peak at 27.1° congruent with the (110) lattice plane of tetragonal rutile TiO2 phase. Dynamic light scattering (DLS) analysis revealed synthesized TiO2 NPs average particle size (hydrodynamic diameter) of (74.8 ± 0.649) nm. Fourier transmission infrared (FTIR) revealed the bioactive components present in the leaf extract, which act as reducing and capping agents. The antimicrobial efficacy of synthesized TiO2NPs against, Staphylococcus aureus, and Bacillus subtilis (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), Yeast strain (Saccharomyces cerevisiae) and fungi (Aspergillus niger, and Penicillium digitatum) assayed by a disc diffusion method. TiO2NPs inhibited all tested strains by mean inhibition zone (MIZ), which ranged from the lowest 15.7 ± 0.45 mm against K. pneumoniae to the highest 30.3 ± 0.25 against Aspergillus niger. The lowest minimum inhibitory concentration (MIC) and bactericidal (MBC) values were 20 μL/mL and 40 μL/mL of TiO2NPs were observed against Asp. niger. Moreover, it showed significant inhibitory activity against human ovarian adenocarcinoma cells with IC50 = 50.13 ± 1.65 µg/mL. The findings concluded that biosynthesized TiO2 NPs using Juniperus phoenicea leaf extract can be used in medicine as curative agents according to their in vitro antibacterial, antifungal, and cytotoxic activities.

Application of natural zeolite clinoptilolite for the removal of ammonia in wastewater

This work intends the characterization of the natural zeolite clinoptilolite and its capability in removing the ammonia in wastewater. The natural zeolite clinoptilolite was characterized using transmittance electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF) and zeta potential prior to the adsorption process. The results showed that the natural zeolite clinoptilolite possessed the lamellar and needle-like structure thus giving the highest surface area for effective adsorption. The main constituent of the element consisted of natural zeolite clinoptilolite is known to have a high affinity towards ammonia. Additionally, the zeta potential analysis has shown that natural zeolite clinoptilolite is negatively charged in all media pH with the highest negative potential of −30 mV recorded at pH 7 thus, contributing to the highly effective electrostatic interaction with the contaminants’ cations. Consequently, the excellent performance in removing ammonia of up to 82.97 % has revealed that the natural zeolite clinoptilolite has a great potential to be developed as a synergized adsorptive ceramic membrane that is combining the adsorption and the filtration of water simultaneously.

Fluorescent nano-sized aggregates of halogen bonded complexes formed using perfluoropropyl iodides: a systematic comparison between two isomeric halogen bond acceptors, aniline and 4-methyl pyridine.

The halogen bonds (XB) formed by the two isomers 4-methyl pyridine (MePy) and aniline (ANL) with heptafluoro-1-propyl iodide (n-C3F7I) and heptafluoro-2-propyl iodide (iso-C3F7I) were investigated using vibrational (FT-IR and Raman) spectroscopy and quantum mechanical calculations. While these two isomers indicated a distinctive impact on the ring related vibrations, molecular electrostatic potential, frontier molecular orbitals, intermolecular electron density delocalisation and consequential charge transfer upon halogen bonding with n-C3F7I and iso-C3F7I, the dramatic intermolecular charge transfer (CT) occurring on the MePy involved XB systems demonstrated an ion-pair like aggregation. Such aggregation, after 72 h and longer after mixing, leads to an emission of fluorescence for both [MePy·C3F7I] systems. The resulting nano-sized aggregates were characterised using UV-Vis absorption and fluorescence spectroscopy along with scanning and transmittance electron microscopy (SEM and TEM), wherein, the XB complex with iso-C3F7I showed a faster and more severe aggregation due to a stronger CT than that with n-C3F7I. The present work is the first case of aggregation induced emission (AIE) due to aggregation of XB complexes formed by small neutral molecules.

Synthesis, characterization and analytical applications of cobalt ferrite nanoparticles

• CoFe 2 O 4 nanoparticless have been prepared. • The isolated nanoparticles have been characterized by IR, XRD, TEM and SAED • The analytical applications of CoFe 2 O 4 have been studied. A simple, rapid, and reliable method for adsorptive separation and pre-concentration of Zn(II) ions in aqueous solution using cobalt ferrite nanoparticles as adsorbent followed by spectrophotometric determination has been developed. Cobalt ferrite nanoparticles (CFNs) have been synthesized by co-precipitation method and characterized by infrared (IR), x-ray powder diffraction (XRD), high resolution transmittance electron microscope (HR-TEM) and selected area electron diffraction (SAED). The results indicated that the average particle size is 8.0 nm. The results of the adsorptive separation and pre-concentration of Zn(II) ions using CoFe 2 O 4 nanoparticles as adsorbent showed an extraction recovery > 98% from 50 mL aqueous sample at pH 8, initial Zn(II) concentration 0.05 mg/L, adsorbent dose 2 g/L and 2 mL of 0.5 M HNO 3 as eluent. The pre-concentration factor obtained was 25 under these optimum conditions. The pre-concentration factor obtained was 25 under ideal experimental circumstances. The suggested method was successfully applied for determination of trace zinc concentrations in several water samples using flame atomic absorption spectrophotometry and satisfactory results were obtained.

Recycling‐Induced Copper Contamination of a 42CrMo4 Quench and Tempering Steel: Alterations in Transformation Behavior and Mechanical Properties

The transformation behavior and the mechanical properties of three laboratory produced steels are presented. To investigate the influence of copper contamination, the reference alloy 42CrMo4 is modified and alloyed with 0.5 and 1.0 wt% copper, respectively. The transformation behavior is investigated through dilatometry that yields continuous cooling transformation diagrams, while the mechanical properties are investigated by hardness measurements as well as Charpy‐V‐notch impact and tensile tests. Accompanying microstructure investigations by means of light optical, scanning electron, and transmissions electron microscopy and thermodynamic simulations (CALPHAD) are performed. It is demonstrated that copper contamination that will be unavoidable when increasing the overall steel recycling fraction may contain the potential for increasing the hardness as well the strength of standard high strength steels, although it is considered to be very detrimental during steel production. Together with reduced environmental footprints and production costs due to the utilization of lower grade scrap with more Cu‐contamination, the development of alternative processing routes for Cu‐contamination‐tolerant high strength steels is pursued.

Synthesis and characterization of nano bioactive glass for improving enamel remineralization ability of casein phosphopeptide–amorphous calcium phosphate (CPP-ACP)

ObjectiveNanomaterials with superior properties such as high surface area over volume ratio are widely used in dentistry and medicine. This in vitro study was performed to synthesize and characterize nano bioactive glass (nBG) and to evaluate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) containing nBG (CPP-ACP@nBG) on enamel remineralization by its application to pH-cycled, synthetically demineralized enamel surfaces.Materials and methodsnBG particles were prepared by sol-gel method. X-ray diffraction pattern (XRD), Fourier-transform infrared spectroscopy (FTIR) and transmittance electron microscopy (TEM) were used for nBG characterization. Synthetic CPP-ACP paste was prepared and nBG particles were added to it. To evaluate the degree of remineralization, 32 healthy human premolars were selected. The samples were randomly divided into 4 groups as: Group 1: Commercial CPP-ACFP (MI paste plus), Group 2: Synthetic casein phosphopeptide-amorphous calcium phosphate containing fluoride (CPP-ACP@F), Group 3: Synthetic CPP/ACP containing nBG (CPP-ACP@nBG), and Group 4: Control (received no treatment). The pastes were then applied on the tooth surfaces for 28 days. The Vickers microhardness of enamel surfaces was evaluated, and enamel surface morphology was assessed using scanning electron microscopy (SEM).ResultsX-Ray diffraction pattern (XRD) of the synthesized nBG show its crystalline nature with the Larnite crystalline mode. Transmittance electron microscope (TEM) microimage of the synthesized nBG shows its formation as less that 100 nm spherical nanoparticle with partial agglomeration. Fourier transform infrared spectroscopy (FTIR) confirm the success formation of nBG with high purity. The results of this study showed that microhardness of the experimental groups was significantly higher than the control group (p ≥ 0.05). SEM images showed a layer of hydroxyapatite in the CPP-ACP@nBG, synthetic and commercial CPP-ACP@F remineralized groups.ConclusionThe results of this study demonstrated that CPP-ACP@F and CPP-ACP@nBG remineralize the surface of the demineralized enamel. Microhardness of the remineralized enamel in the CPP-ACP@nBG group was higher than synthetic and commercial CPP-ACP@F groups.

Studies of the Photoprotection of Radiata Pine Wood Using Photocatalytic Nanoparticles

In this work, TiO2 and ZnO nanoparticles of different sizes and crystallographic configuration were used to protect wood surfaces against UV radiation. The sizes and levels of photoactivity of the nanoparticles were measured in vitro by transmittance electron microscopy and electron paramagnetic resonance spectroscopy, and then they were impregnated into radiata pine samples. The production of aromatic radicals, absorbance of UV and visible light, and chemical and color changes of treated and untreated wood surfaces were assessed after UV irradiation. Results show that nanoparticles that were less photoactive were better at reducing the production of organic radicals and the chemical and color changes on wood surfaces subjected to UV. Similarly, smaller nanoparticles (40 nm) were better at reducing photochemical reactions than larger (100 nm) nanoparticles. In terms of the crystallographic configuration of nanoparticles, differences in the production of phenoxy radicals were verified only for short-term exposure. Previous research revealed that certain levels of photoactivity in TiO2 nanoparticles may contribute to decreases in the photodegradation of wood surfaces possibly by an electron sink mechanism. Our observations indicate that this is unlikely to occur in the presence of highly photoactive nanoparticles.

Fabrication of mesoporous zirconia and titania nanomaterials for bone regeneration and drug delivery applications

Mesoporous materials have reached a significant milestone in the last twenty years in the field of drug delivery, and they continue to be an important part of development and innovation in pharmacodynamics and pharmacokinetics. In addition, their applications in the regeneration of hard tissues were greatly explored in recent decades due to their exponential biomineralization capabilities. They are the perfect candidates for active uptake and loading medicinal substances due to their unique chemical-physical properties. In this research, mesoporous zirconia (MZNs) and titania (MTNs) nanopowders were prepared by polymer sacrificial method as amoxicillin delivery systems. They were investigated using several characterization techniques including X-rays diffraction (XRD), Fourier transform infrared (FTIR), Transmittance electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) surface area measurements. These techniques assist in evaluating the appropriate pore size and diameter, with emphasis on the safety of the released drugs. Amoxicillin release form MZNs and MTNs was conducted in Phosphate buffer saline (PBS) up to 28 days. The possibility of using these antibacterial agents against different strains of gram-positive and gram-negative bacteria has been evaluated. Finally viabilities of the human bone osteosarcoma cell line (MG-63) were tested. MZNs and MTNs demonstrate particle diameters in range of (8–25 nm) and they were confirmed as mesoporous particles by TEM and BET techniques. Amoxicillin loaded nanopowders showed good antibacterial and antifungal activities alongside with proliferation behavior after 24 h (124 and 110%) for MZNs & MTNs, respectively, and (189 and 114%) for amoxicillin loaded MZNs & MTNs, respectively. Therefore, the developed nanomaterials are of high potentiality to be implemented as medication delivery systems for bone regeneration.

Influence of the Carbidized Tungsten Surface on the Processes of Interaction with Helium Plasma.

This paper presents the results of experimental studies of the interaction of helium plasma with a near-surface tungsten carbide layer. The experiments were implemented at the plasma-beam installation. The helium plasma loading conditions were close to those expected in the ITER divertor. The technology of the plasma irradiation was applied in a stationary type linear accelerator. The impact of the helium plasma was realized in the course of the experiment with the temperatures of ~905 °C and ~1750 °C, which were calculated by simulating heat loading on a tungsten monoblock of the ITER divertor under the plasma irradiation at the load of 10 MW/m2 and 20 MW/m2, respectively. The structure was investigated with scanning microscopy, transmitting electron microscopy and X-ray analysis. The data were obtained showing that the surface morphology changed due to the erosion. It was found that the carbidization extremely impacted the plasma-tungsten interaction, as the plasma-tungsten interaction with the carbide layer led to the carbon sputtering and partial diffusion towards to the depth of the sample. According to these results, WC-based tungsten carbide is less protected against fracture by helium than W and W2C. An increase in temperature leads to much more extensive surface damage accompanied by the formation of molten and recrystallized flanges.

Comparison of the Estimation Ability of the Tensile Index of Paper Impregnated by UF-Modified Starch Adhesive Using ANFIS and MLR

The purpose of the present study is to offer an optimal model to predict the tensile index of the paper being consumed to make veneer impregnated with different weight ratios of modified starch (from 3.18 to 36.8%) to urea formaldehyde resin (WR) containing different formaldehyde to urea molar ratios (MR, from 1.16:1 to 2.84:1) enriched by different contents of silicon nano-oxide (NC, from 0 to 4%) using multiple linear regression (MLR) and adaptive neuro-fuzzy inference system (ANFIS) and compare the precision of these two models to estimate the response being examined (tensile index). Fourier-transform infrared spectroscopy (FTIR) and transmittance electron microscopy (TEM) were also used to analyze the results. The results of studying the adhesive structure using FTIR analysis showed that as the WR increased to the maximum level and MR increased to the average level (3%), more ether and methylene linkage forms due to cross-linking. TEM analysis also indicated that if an average level of silicon nano-oxide is applied, there will be more cross-linking due to the more uniform distribution and suitable interactions between the adhesive and nanoparticles. The modeling results showed that the ANFIS model estimates have been closer to the actual values compared to the MLR model. It can be concluded that the model offered by ANFIS has a higher potential to predict the tensile index of the paper impregnated with the combined adhesive of UF resin and modified starch. However, the MLR model could not offer a good estimate to predict the response. According to the preferred approach to predict the most effective property of resin coated paper, modelling would be useful to the research community and the results are beneficial in industrial applications without spending more cost and time.