Search

Designing a nanocomposite that accumulates biocompatibility and anti-microbial behavior is an essential requirement for biomedical applications. Hydroxyapatite, graphene oxide, and vivianite in one ternary nanocomposite with three phases and shapes led to an increase in the cell viability to 97.6 ± 4 % toward the osteoblast cells in vitro. The obtained nanocomposites were investigated in structural features using x-ray diffraction (XRD), while the microstructure features were analyzed using a scanning electron microscope (SEM) and transmission electron microscope (TEM). The analysis showed decreasing in the crystal size to 13 nm, while the grains of HAP reached 30 nm. The elongated shape of vivianite reached 200 nm upon SEM micrographs. The monoclinic and hexagonal crystal systems of HAP and vivianite were presented in the ternary nanocomposite. The maximum roughness peak height (Rtm) reached 236.1 nm for the ternary nanocomposite from 203.3 nm, while the maximum height of roughness parameter (Rt) reached 440.7 nm for the di-nanocomposite of HAP/GO from 419.7 nm. The corrosion current density reached 0.004 μA/cm2 . The ferrous (Fe2+ ) and calcium (Ca2+ ) ions released were measured and confirmed. Therefore, the morphology of the nanocomposites affected bacterial activity. It is estimated as an inhibition zone and reached 14.5 ± 0.9 and 13.4 ± 1.1 mm against E. coli and S. aureus after 24 h in vitro. The increase in viability and the antibacterial activity refer to the compatibility of the nanocomposite in different medical applications.

The results of the analysis on some fragments of bronze belts and a bowl discovered from southwestern Armenia, Yegheghnadzor archaeological site, are discussed. The samples are dated to the 7-6 BCE from the Urartian period. The artifacts were corroded and a multilayer structure was formed. To study the stratigraphy of layers and their composition the samples have been analyzed using SEM-EDS (Scanning Electron Microscopy, Energy Dispersive Spectrometry) and OM (Optical Microscopy) techniques. The bronze finds appear with the typical incrustations rich in alloy alteration compounds. Concentrations of copper and tin in the alloys were quantified by SEM-EDS: the pattern and the percentage of the alloy are the same for the belts. Regarding the bowl sample, it is constituted by two foils, perfectly in contact but different in colour, thickness and composition. The results evidenced that only two elements participate in forming alloy composition in the samples: Cu and Sn. The tin content is variable from 7.75 to 13.56%. Other elements such as Ag, As, Fe, Ni, P, Pb, Sb, and Zn are lower more than 1% and can be considered as impurities. This article is protected by copyright. All rights reserved.

Bacterial sample preparation is crucial for its observation by scanning electron microscopy (SEM). However, the current polylysine (PLL) method leads to bacterial morphological changes. To overcome this problem, we employed chitosan (CS) to coat coverslips to prepare bacteria for SEM and compared it with the PLL method. Coverslips coated with 0.025% (w/v) CS showed satisfactory bacterial binding ability. Within 30 min of binding time, the number of bacteria on CS-coated and PLL-coated coverslips exhibited no differences. Four bacteria strains were employed to compare the differences in SEM images between the two methods. Most of the bacteria showed irregular surface or sticky substances after settling on PLL-coated coverslips, while bacteria with clear surface texture were observed on CS-coated coverslips. Transmission electron microscopy (TEM) images showed deformed bacterial envelope on PLL-coated coverslips; meanwhile, similar intact envelope was observed from the bacteria on CS-coated coverslips and the bacteria without any treatment. The TEM results verified the morphological differences of SEM between the two methods. Except for morphology, the length of the rod-shaped bacteria was longer on CS-coated coverslips than that on PLL-coated coverslips, less shrinkage of the sample was observed, and CS could preserve the length of the rod-shaped bacteria better than PLL in its preparation for SEM. It is demonstrated that the low-cost CS could be utilized in bacterial preparation for SEM to acquire preferable images. Bacterial suspension with optical density at 600 nm of about 0.5, deposited on 0.025% CS-coated coverslips for 30 min, and followed by routine fixation, dehydration, and drying are optimal parameters.

Background The major by-products of mango processing are the seeds, which represent approximately 15 to 20% of the fruit. The process protocol for isolation of starch from mango kernel was standardized based on starch yield, starch purity and color values using centrifugation and chemical method. Optimized starches obtained from both the methods were further investigated for estimation of functional properties and were characterized through Fourier transform infrared spectroscopy, scanning electron microscopy, x-ray diffraction, differential scanning calorimetry and pasting properties analysis. Results The slurry making of mango kernels with solid to water ratio of 1:3 at centrifugation frequency of 3 times was found to be the best among all the experimental combinations (solid to water proportion (1:2, 1:3 and 1:4 w/v) and centrifugation frequency (2, 3, and 4 times)) with a starch yield of 48.43 ± 1.08% and purity of 76.46 ± 0.83%. In chemical method of starch isolation (washing was done with 0.1 N NaOH and 0.1 N HCl at three level each), the sample treated with 60% (w/v) of 0.1 N NaOH and 10% (w/v) of 0.1 N HCl resulted in 36.50 ± 0.58% starch yield with a purity of 92.03 ± 0.87%. Among the functional properties, the chemically isolated starch showed significantly higher paste clarity (45.79 ± 2.36%) than starch obtained using centrifugation process (12.50 ± 1.57%). The chemically isolated starch also exhibited better color attributes which were very close to those of laboratory grade starch. Conclusion Detailed characterization studies inferred that both the starches possessed good functional, structural, and thermal properties indicating suitability for food and nonfood applications. This article is protected by copyright. All rights reserved.

Journal of microscopy (2021). doi:10.1111/jmi.13072, Published by Wiley-Blackwell, Oxford [u.a.]

A semiconductor nano-material was prepared, and its degradation efficiency of zearalenone (ZEN) was studied. The photocatalytic material graphitic carbon nitride (g-C3 N4 ) was synthesized by the traditional method of hot cracking. Its structure was characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic degradation experiment showed that under the irradiation of ultraviolet (UV) lamp (254 nm, including 185 nm), g-C3 N4 could induce photocatalytic effect, which provided a new method for the degradation of ZEN in real powder samples. The experimental conditions of photocatalytic degradation of the primary reference material of ZEN and ZEN in real powder samples were explored. And the degradation products of ZEN were analyzed after high-performance liquid chromatography-mass spectrometry (HPLC-MS). Under each optimal experimental conditions, the degradation rate on primary reference material of ZEN and ZEN in real powder samples was 96.0% and 50.0%, respectively. The results in this work provide a theoretical reference and practical basis for the photocatalytic degradation of mycotoxin in real powder samples by g-C3 N4 .

A multifractal analysis has been performed on the 3D (three-dimensional) surface microtexture of magnesium-doped zinc oxide (ZnO:Mg) thin films with doping concentration of 0, 2, 4, and 5%. Thin films were deposited onto the glass substrates via the sol-gel spin coating method. The effect of magnesium doping, on the crystal structure, morphology, and band gap for ZnO:Mg thin films has been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and UV-Vis spectroscopy. It has been observed that the surface of ZnO thin films is multifractal in nature. However, multifractality and complexity observed to decrease with increasing content of Mg in ZnO thin films due to formation of islands on the surface in accordance with Volmer-Weber growth mechanism. The investigations revealed that crystallinity, microtexture, morphology, and optical properties of the thin films can be tuned by controlling the Mg content within the ZnO lattice. In particular, their optical band gap energies were 3.27, 3.31, 3.34, and 3.33 eV at 0, 2, 4, and 5%, respectively. The prepared thin films of ZnO:Mg with tuned characteristics would have promising applications in optoelectronic devices.

Photochromic and long-lasting photoluminescent transparent, rigid, ultraviolet (UV) protective and superhydrophobic poly(methyl methacrylate) (PMMA) plastic able to switch colour beneath UV irradiation was developed. Photoluminescent transparent PMMA plastic was prepared by the simple polymerization process of methyl methacrylate immobilized with alkaline earth aluminate (AEA) nanoparticles. These colourless PMMA plastic substrates showed a colour switch to greenish underneath UV light as proved using CIELAB screening. The morphology of AEA was evaluated using transmission electron microscopy. Conversely, transparent PMMA samples were evaluated using energy-dispersive X-ray spectra, scanning electron microscope, X-ray fluorescence spectroscopy and for hardness properties. Additionally, the photoluminescence properties were explored by studying excitation and emission spectra. The produced luminescence colourless PMMA plastic substrates displayed excitation band at 370 nm, and three emission peaks at 433, 494 and 513 nm. Photoluminescent PMMA with lower contents of AEA showed fast and reversible photochromism under UV light, while PMMA samples with higher contents of AEA showed long-lasting luminescence such as a flashlight with the ability to replace electric power. The findings showed that the produced photoluminescence colourless PMMA plastic substrates exhibited enhanced UV shielding and superhydrophobicity.

During the reduction of molybdenum trioxide (MoO3 ) to metallic molybdenum, the first reduction step yielding molybdenum dioxide as an intermediary product is of crucial importance. In this study, we examined the impact of the parameters reduction temperature, water influx, and potassium content on the hydrogen reduction of this first reaction step. Beginning from the same starting material, the chemical vapor transport mechanism was utilized to yield the phase pure MoO2 . Analyses including powder X-ray diffraction, inductively coupled plasma-mass spectrometry, scanning electron microscopy, and high performance optical microscopy were performed on the product phases. Modulations of the specific surface areas of molybdenum dioxide ranging from 2.28 to 0.41 m2 /g were possible. Furthermore, a distinct shift from small plate-like grains to cuboid-like forms was achieved.

International audience; Plasma etching techniques can result in damage and contamination of materials, which, if not removed, can interfere with further processing. Therefore, characterisation of the etched surface is necessary to understand the basic mechanisms involved in the etching process and enable process control and cleaning procedures to be developed. A detailed investigation by means of the combined use of scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM/EDS), X-ray photoelectron spectroscopy (XPS) and optical microscopy (OM) has been carried out on deep titanium trenches etched by plasma. This innovative approach has provided a further insight into the microchemical structure of the surface contamination layer on both the titanium and the nickel hard mask surfaces. The described experiments were conducted on 25 to 100-mu m wide trenches, first etched in bulk titanium by an optimised Cl-2/SF6/O-2-based inductively coupled plasma process, through an electroplated nickel hard mask. The results allow to identify chlorine, fluorine and carbon as the main contaminating agents of the nickel mask and to associate three oxidation states around the etched trenches highlighting certain specific aspects related to the passivation mechanism. These observations reinforce the scientific relevance of the combined use of complementary optical and imaging analytical techniques.

Purpose To evaluate the effect of different polishing pastes with different particle sizes on the surface finish of two different CAD/CAM ceramics. Materials and methods A total of 128 specimens were prepared of two CAD/CAM ceramics: lithium disilicate (12.4×14.5×2mm) and monolithic zirconia (17.5×12.5×2.5mm). They were divided randomly into 8 groups according to surface treatment (n = 8). Group 1 (control) was left as received after crystallization or sintering with no further surface treatment; Group 2 (glazed); Group 3 (positive control), where specimens were polished using standardized surface treatment (medium grit silicon carbide discs, rubber cup and pumice slurry, then rubber cup and toothpaste). For groups 4-8, in addition to silicon carbide and pumice slurry polishing, specimens were further polished using a diamond paste (DP), and polishing pastes of microzirconia (MZ), nanosilica (NS), nanodiamond (ND), and nanozirconia (NZ), respectively. Surface roughness (Ra ) was measured using non-contact profilometer. The mean values were compared using ANOVA and Post-Hoc Tukey's test (α = 0.05). Specimens' surfaces were studied using a scanning electron microscope (SEM). Results Positive control group and MZ exhibited significant Ra of lithium disilicate compared to control (P˂0.001), glazed (P = 0.001), DPs (P = 0.002), NS (P˂0.001), ND (P˂0.001), and NZ (P = 0.002). In the case of zirconia, positive control showed a significantly higher Ra compared to all other groups (p˂0.001). No statistical difference was found between all other polishing techniques (positive control, glazed, DPs, NS, ND, MZ and NZ) (P>0.05). Conclusion Polishing with ND, NZ and NS lab-formulated pastes produced surfaces with comparable smoothness to control and glazed specimens for lithium disilicate and zirconia ceramic materials. This article is protected by copyright. All rights reserved.

This study aimed to evaluate the influence of sterilization methods on conventional and bulk-fill resin composites' (BFRCs) surface properties in an attempt to preview bias in laboratory bacterial adhesion tests. Two regular viscosity conventional resin composites [Filtek Z350 XT™ (Z350) and IPS Empress Direct™ (ED)] and two regular viscosity BFRCs [Filtek Bulk Fill™ (FILT) and Tetric N-Ceram Bulk Fill IVA™ (TBF)] were used. The materials were characterized by Scanning Electron Microscopy (SEM), surface roughness (SR), and wettability (W) after sterilization with hydrogen peroxide gas plasma (HPGP) and steam sterilization (SS). Nonsterilized samples served as a control group (n = 5). Statistical analysis was performed using two-way analysis of variance (ANOVA) and Tukey post hoc test (p 0.05). For SR, there were no statistically significant differences among the groups (p .05). SS method decreased the contact angle for FILT and Z350 (p .01). The SS promoted more exposition of filler particles, while the HPGP method did not alter the tested materials' morphology. Therefore, sterilization methods affected the resin composites tested selectively. HPGP seems to be the most recommended method to sterilize the tested resin composites before laboratory bacterial adhesion tests.

The mineralising effect of CuO on microstructure and phase composition of SO3 -doped clinker was studied by a combination of phase analysis, light and scanning electron microscopy and QXRD. Results show proportionally higher C4 AF content in clinker interstitial matter due to CuO doping. CuO also lowers the SO3 incorporation in main clinker phases C3 S and C2 S. Observation in back-scattered electrons revealed that Cu crystallises mainly as a Cu-rich phase in the clinker interstitial matter and inclusions in crystals of C2 S with distorted structure. CuO partially inhibits the incorporation of Fe2 O3 in C2 S.

Micromorphology of 15 grass caryopsis was investigated through scanning electron microscopy for its implications in the identification of grasses. Both macro and micromorphological characters especially caryopsis shape and surface morphology were found significant in the taxonomic diagnosis. Shape morphology of caryopsis varied among the species and lanceolate, fusiform, narrow ellipsoidal, ovate, elliptical, plano-convex, fusiform, linear ovate, broadly elliptical, broadly pllipsoidal, plano-convex, oblique ovate, and subglobose shapes were recorded. Digitaria nodosa (3.31 × 0.7 mm) and Echinochloa crus-galli (3.26 × 1.44 mm) had the largest caryopsis size, while Acrachne racemosa (0.76 × 0.54 mm) and Eragrostis minor (0.62 × 0.38 mm) had the smallest caryopsis size. Macro and micromorphological characters were useful for the diagnosis of genus and species. Utilizing both qualitative and quantitative character taxonomic key at generic and species level were made.

In this case study, distress mechanism(s) of a concrete structure in the saturated and unsaturated zones of the foundation were investigated. This research was performed using a stereomicroscope, polarised light microscopy (PLM), and a limited study using a scanning electron microscope (SEM) with backscattered electron (BSE). Results of this study showed that concrete cores extracted from both the saturated and unsaturated zones of the foundation exhibited severe to moderate concrete distress, but the cause of the distress/cracking in the concrete was not related to Alkali-Carbonate Reaction (ACR) as was initially suspected. While the damage to the concrete extracted from the structure above the saturated zone of the foundation was caused by a combination of Alkali-Silica Reaction (ASR) and freeze-thaw deterioration, concrete distress in the saturated zone of the foundation was caused primarily by ASR of shale particles in the natural sand fine aggregate. The sand also contained traces of chert particles with ASR. Limited ASR was seen in the crushed gravel coarse aggregate siliceous limestone, dolomitic limestone, and chert particles. Results of this case study showed that siliceous shale particles in the fine aggregate caused detrimental ASR damage to the concrete, and thus caution needs to be exercised when aggregate containing shale is used in concrete.

OBJECTIVES Decontamination of biofilm-colonized rough implant surfaces remains challenging. We investigated the effect of airflow with glycine powder (AFG) on decontamination of mature oral multispecies biofilm from a sandblasted and acid etched (SLA) titanium surface. MATERIALS AND METHODS Subgingival dental plaque was cultured on SLA disks anaerobically for 21 days. AFG with various settings and distances was applied directly on the disks with or without previous rinse of 0.9% NaCl. The specimens were then analyzed through scanning electron microscope and remaining bacteria on the implant surface were quantified and statistically compared. RESULTS Mature oral biofilm with cocci and rods as major morphotypes, as well as spiral- and filamentous-shaped organisms, was formed on the untreated disks. Saline rinsing removed the thick biofilm layer but left numerous of coccoid bacteria in rough surface pits. AFG effectively removed most of the bacteria from the pits. Both 25% and 50% power settings were equally effective at 3-mm distance. With 50% power, AFG successfully removed bacteria at both 3- and 6-mm distance. When AFG was applied on native biofilm without prior rinsing with saline, it effectively removed the biofilm including bacteria in the pits. CONCLUSION Application of AFG appears effective in removing bacteria from rough implant surfaces.

Azobenzene has attracted substantial attention as a photoswitchable molecule since its applications range from energy and data storage to biomedical applications. This work reports a new type of thin-film based on azobenzene derivative anchored to cerium oxide nanoparticles CeO2 NPs for photoswitching applications. The trans-cis isomerization and reverse isomerization occur by UV-light exposure and thermal relaxation process, respectively. The photoisomerization and reverse isomerization kinetics for CeO2 NPs-MR thin films are studied, investigated, and analyzed using UV-Vis absorbance spectra, FTIR spectroscopy, XRD, and scanning electron microscopy (SEM), in addition to differential scanning calorimetry (DSC) measurement to study the energy storage capacity. The results found that anchoring azobenzene to CeO2 NPs is successful in multisource storage of solar energy applications.

The effect of copper (Cu) doping on the luminescent properties of the spray deposited Mg0.2 Zn0.8 S thin films were investigated for the first time. The Mg0.2 Zn0.8 S film is an excellent luminescent material with strong blue emissions. In the current investigation, we doped Mg0.2 Zn0.8 S with Cu by taking (Cu + Mg) as 20 at% by keeping other element ratios constant. Among the different samples in the series, Cu0.05 Mg0.15 Zn0.8 S has shown promising results with dark blue emission. Also, these films showed good structural formation with lower or no other impurities, which is evident from the X-ray diffraction (XRD). Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) confirmed the improved material quality of Cu0.05 Mg0.15 Zn0.8 S as compared to the pristine. Raman and X-ray photoelectron spectroscopy (XPS) studies have been carried out for the samples. Various defects induced in the films were investigated by recording the photoluminescence (PL) spectra and Cu:(Mg0.2 Zn0.8 S) films exhibited the capability to produce dilute blue luminescence by absorbing ultraviolet (UV) light. The Cu0.05 Mg0.15 Zn0.8 S film showed promising material property, which is suitable for light-emitting diode (LED) applications.

OBJECTIVE To analyze the wear rate of computer-aided design and computer-aided manufacturing (CAD/CAM) composites, polyetheretherketones and glass ceramics. MATERIAL AND METHODS Our study groups were prepared from two different resin-based composites (Brillant Crios, Cerasmart), a glass ceramic (IPS Emax CAD) and reinforced polyetheretherketone (BioHPP) material (n = 10). Premolar teeth were used as antagonists. The specimens, which were subjected to two body wear tests (240,000 cycles, 1.2 Hz, 50N) in the chewing simulator, were scanned with a 3D laser scanner both before and after the wear test. Volume loss and wear depth were determined by means of the obtained images software program. The wear pattern was examined by scanning electron microscopy. Kruskal Wallis test served for analyzing. RESULTS The least volume loss and wear depth were seen in the polyetheretherketone material (0.06 ± 0.04 mm3 , 0.02 ± 0.01 mm), while the maximum volume loss was seen in the groups containing resin-based composite. (p = 0.05). The volume loss value in glass ceramics is between CAD/CAM composites and polyetheretherketone. CONCLUSION The behavior of polyetheretherketone against enamel was different from glass ceramics and composite materials in terms of the amount of wear. CLINICAL SIGNIFICANCE Polyetheretheketone can be considered as an alternative to other chairside materials in terms of wear resistance.

Due to increase in energy catastrophe and accompanying environmental issues, the search for renewable and alternative energy resources is a fiercely disputed problem in the scientific world. Biodiesel has proven to be the finest sustainable alternative to gasoline. Because of their environment-friendly character and cost-effectiveness, nonedible oil-bearing seeds could be the possible resource for biodiesel production. Therefore, the present study uses scanning electron microscopy (SEM) to investigate and identify micromorphological features of six novel, nonedible oil-bearing seeds of Verbenaceae as potential biodiesel feed stocks. Selected seeds of Verbenaceae range in size from 1 to 5 mm in width and 1.8 to 6.4 mm in length, according to light microscopic studies. The oil content of seeds ranges from14 to 19%. Seed texture, color, shape, size, periclinal and anticlinal wall patterns, and cell outline are all more variable in SEM-mediated seed ultrastructure analyses. The findings of this work imply that SEM could be a useful method for revealing hidden micromorphological features in a variety of nonedible oil-producing seeds, which could aid to future investigation, proper identification, seed categorization, and authenticity. These seeds were hard to be identified by the native people due to their resemblance in seed color and shape, so there is a need to give a detailed description of seed characters for proper identification of these plants. This work will determine the new features of the seeds, which will be helpful in near future.

This study evaluated the effect of different protocols for Ca(OH)2 removal on the bond strength (BS) of epoxy resin-based sealer in long oval root canals. Forty-eight mandibular incisors with long oval root canals were selected by CBCT. Biomechanical preparation was performed, the samples were filled with Ca(OH)2 paste and distributed in four groups (n = 12): G-without Ca(OH)2 paste (C); G2-syringe/needle (SN); G3-SN + XP-Endo® Finisher (XPF); G4-SN + passive ultrasonic irrigation (PUI). After 7 days, Ca(OH)2 was removed and teeth were filled using AHPlus and guttapercha. In four samples from each group, the sealer was manipulated with 0.1% rhodamine to assess sealer penetration by fluorescent laser confocal microscopy (FLCM). Samples were sectioned in slices for BS, scanning electron microscopy, and FLCM analysis. The BS data were analyzed by ANOVA and Tukey tests (α = 0.05). The lowest BS values were found for the SN group (12.89 ± 4.36) compared to C (35.55 ± 10.05), while PUI group presented intermediate values (28.57 ± 9.35) and the XPF group (31.34 ± 9.8) showed values that were sometimes similar to C group and sometimes similar to PUI group (p > .05). The analysis of the adhesive interface showed evident gaps, with the presence of residues between the dentin and the filling material for the SN group, and for C, XPF and PUI groups juxtaposed adhesive interface. FLCM images showed sealer penetration in the dentinal tubules along the entire perimeter for C, XPF, and PUI groups. Ca(OH)2 removal with XPF and PUI from long oval root canals resulted in higher bond strength values compared to SN, besides better sealer penetration on dentinal tubules and juxtaposed adhesive interface.

A highly efficient fluoride adsorbent Al2 O3 /CeO2 was synthesized in this work and used it to fluoride removal in the fixed-bed adsorption through changing the different experimental conditions (influent F- concentration, flow velocity, and bed heights). The adsorption capacity was 9.72 mg/g. In addition, the Adams-Bohart and Thomas models were used to fit and evaluate the column breakthrough curve of fluoride removal process by Al2 O3 /CeO2 , and the correlation coefficients (R2 ) of the Thomas model were close to 1 under all experimental conditions. The structure of Al2 O3 /CeO2 and the adsorption mechanism were confirmed by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), N2 adsorption and desorption isotherm, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Moreover, the adsorption of fluoride (F- ) was mainly through metal binding (MF) and hydroxyl binding (AlOH⋯F) on the surface of the Al2 O3 /CeO2 . Furthermore, the regeneration and coexisting anions studies of Al2 O3 /CeO2 were carried out, and the efficiency of adsorption was still above 70% after five cycles. PRACTITIONER POINTS: Removal of fluoride was studied by fixed-bed experiment, and the adsorption capacity of composite Al2 O3 /CeO2 was 9.72 mg/g. The metal complex played important role in fluoride removal and reusability makes a long-term application for fluoride adsorption. Fluoride wastewater is pumped to the fixed-bed column, and fluoride ions are absorbed by Al2 O3 /CeO2 through fluoride metal complex and aluminum hydrofluoride.

In the present era, environmental glitches associated with extensive emission of greenhouse gases (GHG) and energy crises caused by exhausting fossil fuel reservoirs has diverted researcher's interest toward alternative and renewable energy sources. Biodiesel is a renewable, biodegradable, and sustainable alternative to petro-diesel. Biodiesel synthesized from non-edible seed oils is preferred due its cost effectiveness and eco-friendly nature. Hence, our present study focused on investigation and identification of micromorphological characters of six novel, non-edible seed oil feedstock for biodiesel production via scanning electron microscopy (SEM). Results of light microscopy of seeds revealed distinct variation in seed size (15.8-1.8 mm in length and 9.4-1.1 in width), shape (round to Cuneiform), and color (from black to yellowish green). Non-edible seed oil content fall in range of 28-38% (wt/wt). Free fatty acid (FFA) content varied from 0.56 to 2.06 mg KOH/g. Multivariate analysis was performed to investigate correlation between three significant variables of seed oil yielding feedstock such as potential for biodiesel synthesis, oil content, and FFA content via principal component analysis. Ultra morphological investigation of seeds surfaces via SEM exhibited distinctive variation in surface sculpturing, cell arrangement, cell shape, periclinal wall shape, margins, protuberances, and anticlinal wall shape. Seed surface sculpturing varied from reticulate, semitectate, wrinkled, rugose, papillate, perforate, and striate. Periclinal wall arrangements confirmed variation from glabrous, raised, depressed, elevated, smooth, pentagonal, entire, and ripple margins. Whereas, anticlinal walls pattern demonstrated variation from angular, smooth, wavy, deep, dentate, entire, irregular, puzzled, elongated, curved, and depressed. Finally, it was concluded from obtained results that SEM could be a possible useful tool in disclosing veiled micromorphological characters of non-edible oil yielding seeds, which provides useful information to researchers for their correct, authentic identification, and classification in modern synthetic system.

AIM To fabricate and characterize nano-hydroxyapatite (nHA) grafted and non-grafted glass fibre-based endodontic posts. METHODOLOGY Experimental glass fibre posts were fabricated using silanized nHA grafted (ex-HA) and non-grafted glass fibre (ex-P) reinforced resins. The structural analysis and morphological patterns were analysed with Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. EverStick® glass fibre posts (eS) were used as a control group. The degree of conversion, flexural strength, and flexural modulus was investigated and the fractured structure was evaluated with a scanning electron microscope. Root canals were prepared in human extracted teeth restored with experimental and control posts. The push-out bond strength was evaluated with radicular dentine at days 7, 30, and 90, and the presence of voids at the interface were measured at day 1, 7, 30, and 90 with micro-computed tomography. The Shapiro-Wilk test and one-way ANOVA post-hoc Tukey's test were performed. The level of significance was set at 0.05. RESULTS The SEM and FTIR confirmed the presence of a silane-coupling agent on the glass fibres. The ex-HA post had a significantly lower degree of conversion compared to the ex-P post (p = .0008), but a significantly higher conversion than the eS post (p = .0014). The maximum flexural strength value was obtained with the ex-HA post with an insignificant difference (p = .366) compared to ex-P post and a significant difference (p = .029) compared to the eS post. The flexural modulus of ex-HA, ex-P, and eS posts were significantly different (p = .037). Similarly, the ex-HA post had a significantly higher push-out bond strength at days 7 and 30 (p = .037) compared to the ex-P and eS posts. The volume of voids had a nonlinear behaviour amongst the groups with no significant difference between the posts. CONCLUSION The fabrication of the experimental posts was successful and the ex-HA post had greater flexural strength and push-out bond strength compared to the ex-P post. The degree of conversion of the ex-HA post was lower than the ex-P and eS posts. The volume of voids of ex-HA and ex-P posts was lower than that of eS posts.

The purpose was to investigate the surface characteristics of various resin-based materials by immersing in probiotic beverages. A total of 420 disc-shaped samples (5 mm × 2 mm) were prepared from resin-based composites. Samples were divided into four groups and immersed for 10 min/day for 1 month in either a probiotic sachet, kefir, kombucha, or artificial saliva (control). Surface roughness was measured at baseline and 1 month. One sample of each of the tested materials was examined under nanoindentation to evaluate the reduced elasticity modulus and nanohardness scores. Scanning electron microscopy (SEM) was used to compare surface differences. Data were analyzed statistically using one-way ANOVA test and the significance was set at p < .05. The lowest roughness scores were observed in Z250, Estelite Bulk Fill, and HRi ENA in most of the test groups. Among conventional composites, Z250 group had the highest nanohardness and elasticity modulus scores. Among bulk-fill composites, Estelite Bulk Fill Flow had the lowest surface roughness after immersion in probiotic beverages and the highest nanohardness values. Reveal HD, as a bulk-fill group showed higher surface roughness and considerably lower nanohardness and elasticity modulus scores. Maximum height levels of samples were recorded. SEM images revealed voids and microcracks on the surfaces of test materials. Dentists may prefer Z250 as microhybrid and Estelite Bulk Fill Flow as bulk-fill composites for the restorations of patients who consume gut-friendly drinks regularly. When there are various types of materials, nanoindentation is a useful method for evaluating surface alterations and sensible comparisons.

The precise arrangement of single entity is a crucial objective of nanoscience and holds great promise in various fields such as biology and material science. In this work, we develop a "DNA framework-mediated geometric renormalization" (DFMGR) strategy to reassemble gold nanoparticles into specific geometric shapes on a 2-dimensional (2D) fluidic membrane interface. Cholesterol-modified AuNPs are randomly anchored on the supported lipid bilayer (SLB) via the cholesterol-lipid interaction. We demonstrate that AuNPs are laterally mobile on SLB and could be further rearranged into a specific geometric shape by DNA framework containing algebraically topological DNA arms. Using scanning electron microscope (SEM) imaging approach, simple geometric shapes, such as points assembled by monomers, line segments assembled by dimers, triangles assembled by trimers are visually presented. Interestingly, we found that the statistic angle (58.77°) and side length (12.21 nm) of triangles obtained from SEM images were both agreed well with the theoretical angle of 60° and side length of 12.58 nm. And the relative error of the angle calculated was as low as 0.33 %. These results indicated that the DFMGR strategy showed precise regulation ability for the AuNPs renormalization. We believe that DNA framework-mediated geometric renormalization strategy would be a powerful means for regulating ligand-receptor interactions in biosystems and for nanoparticle assembling in material science.

Dentin hypersensitivity (DH) is characterized by pain caused by an external stimulus on exposed dentin. Different therapeutic approaches have been proposed to mitigate this problem; however, none of them provide permanent pain relief. In this study, we synthesized and characterized experimental bioactive glasses containing 3.07 mol% SrO or 3.36 mol% K2 O (both equivalent to 5 wt% in the glass), and evaluated their effect on dentin permeability to verify their potential to treat DH. The experimental materials were characterized by field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, micro-Raman spectroscopy, and X-ray diffraction to confirm the respective structures and chemical compositions. The reduction in the hydraulic conductance of dentin was evaluated at the three stages: minimum permeability; maximum permeability (24% ethylenediaminetetraacetic acid [EDTA] treatment); and final dentin permeability after treatment with the bioactive glasses. They all promoted a reduction in dentin permeability, with a significant difference for each sample and posttreatment group. Also, a significant reduction in dentin permeability was observed even after a simulated toothbrushing test, demonstrating effective action of these materials against DH. Besides, incorporating 3.07 mol% SrO was a positive factor. Therefore, strontium's desensitizing and re-mineralizing properties can be further exploited in bioactive glasses to promote a synergistic effect to treat DH.

In this study, well-defined core-shell ethylenediamine-functional magnetic ferroferric oxide polymers were prepared and were fully characterized by transmission electron microscopy, scanning electron microscopy, FTIR spectroscopy, and vibrating sample magnetometry. Then, it was used as a magnetic solid-phase extraction adsorbent for simultaneous determination of 11 trace quinolone residues in freshwater fish samples coupled to liquid chromatography-tandem mass spectrometry. The obtained results revealed that the adsorbent showed good extraction efficiency and the adsorption mechanisms referred to hydrogen bond and π-π stacking interaction. Moreover, the magnetic solid-phase extraction conditions were also carefully optimized. The limits of quantitation of 11 quinolones were in the range of 0.15-0.36 μg/kg, while spiking recoveries were in the range of 80.2-99.5% for the 11 quinolones in freshwater fish samples at four spiked levels including limits of quantitation, 1.0, 40.0, and 80.0 μg/kg with the relative standard deviations ranging from 0.8 to 9.1%. The proposed method was applied to analyze 45 freshwater fish samples, and enrofloxacin was detected in 91.1% samples with concentrations ranging from 0.659 to 333 μg/kg. It could be concluded that the proposed method is fast, simple, sensitive, and accurate for the routine monitor of freshwater fish.

OBJECTIVES To examine anti-adhesion and anti-biofilm effects of a diamond-like carbon coating deposited via a novel technique on the inner surface of a thin silicon tube. METHODS Diamond-like carbon coatings were deposited into the lumen of a silicon tube with inner diameters of 2 mm. The surface of the diamond-like carbon was evaluated using physicochemical methods. We used three clinical isolates including green fluorescent protein-expressing Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus. We employed a continuous flow system for evaluation of both bacterial adhesion and biofilm formation. Bacterial adhesion assays consisted of counting the number of colony-forming units and visualization of adhered bacterial cells by scanning electron microscope to evaluate the diamond-like carbon-coated/uncoated samples. The biofilm structure was analyzed by confocal laser scanning microscopy on days 3, 5, 7 and 14 for green fluorescent protein-expressing Pseudomonas aeruginosa. RESULTS The smooth and carbon-rich structure of the intraluminal diamond-like carbon film remained unchanged after the experiments. The numbers of colony-forming units suggested lower adherence of green fluorescent protein-expressing Pseudomonas aeruginosa and Escherichia coli in the diamond-like carbon-coated samples compared with the uncoated samples. The scanning electron microscope images showed adhered green fluorescent protein-expressing Pseudomonas aeruginosa cells without formation of microcolonies on the diamond-like carbon-coated samples. Finally, biofilm formation on the diamond-like carbon-coated samples was lower until at least day 14 compared with the uncoated samples. CONCLUSIONS Intraluminal diamond-like carbon coating on a silicone tube has anti-adhesion and anti-biofilm effects. This technology can be applied to urinary catheters made from various materials.

An electron backscatter diffraction device is an important accessory for a scanning electron microscope and can provide crystal structure orientation and phase content data through analysis of electron backscatter diffraction patterns. The acquisition of these data depends on pattern indexing, including interplanar angle calculation and crystal plane indexation. The coordinates of the source point are key points for interplanar angle calculation, and they vary with the movement of the incident beam. In this study, we first combined the grey gradient calculation with screen moving method to achieve accurate positioning of source point and obtained coordinates of source point with sub-pixel precision. The errors of three coordinates were 0.07%, 0.06% and 0.04%, respectively. By using this coordinate of source point to conduct interplanar angle calculation the maximum error was 0.53°, which was a good proof of the accuracy of source point positioning. Then we established the relationship between source point coordinates variation and incident beam movement. Coordinates can be given out based on the displacement of beam directly. And to illustrate the accuracy, interplanar angle calculation was performed and the maximum error was 0.81°. This means that the relationship between variation of source point coordinates and beam movement is highly accurate.

Marine facilities and ships are easily plagued by biofouling. Synergistic surfaces combining surface reactive ion etching and peptide modification were designed and prepared to tackle surface biofouling. Six microstructural surfaces were first designed and machined based on the contact point theory; the synergistic surfaces were then prepared by peptide modification. Laser confocal scanning microscope (LCSM), scanning electron microscopy (SEM), contact angle measurement, and X-ray photoelectron spectroscopy (XPS) were utilized to analyze the surface morphology and surface chemical properties; the results demonstrated that six synergistic surfaces were prepared successfully with 0.8-mu m depth, surface contact angle increased from 75 degrees to 116.99 degrees, and the surface chemical compositions were also changed significantly due to peptide modification. Antibiofilm assays showed that surface modification and surface topology could slightly reduce the formation of biofilm. While the synergistic surfaces possess strong anti-algal performance, and anti-Chlorella pyrenoidosa (C. pyrenoidosa) and anti-Phaeodactylum tricornutum (P. tricornutum) rates reached 78.56% and 87.80%, respectively after 7-day immersion in artificial seawater. Compared with the single surface treatment method, the antifouling performance of the synergetic surfaces were stronger. This strategy demonstrated a realistic paradigm for the further improving surface antifouling performance in a green method.

This study was planned to explore the in-vitro and in-vivo therapeutic significance of Paeonia emodi-mediated zinc oxide nanoparticles (ZnO NPs) against the Staphylococcus aureus and Escherichia coli. The texture parameters were derived from nitrogen adsorption-desorption data using Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods, and the surface area (SBET ) was found to be 214 m2 /g with a pore size of 2.3 nm. The crystallographic parameters were investigated through X-ray diffraction analysis, and the calculated crystallite size is 29.13 nm. The microstructure was examined through transmission and scanning electron microscopies (TEM and SEM, respectively), and the average particle size estimated from a TEM image is 44.40 nm. The chemical composition and attached function groups were identified through energy-dispersive X-ray and Fourier transform infrared spectroscopies. The in-vitro minimum inhibitory concentration (MIC) for both bacterial species results was found less than 2 μg/ml. The tolerance limit of mouse models was evaluated by the inoculation of different concentrations of ZnO suspension where the concentration above 23 ppm was proved lethal. The maximum infection was caused in mouse models by inoculation of 3 × 107 CFUs (Colony forming unit) of the both bacterial species. The concentration higher than 3 × 107 CFUs led to the ultimate death of the mice. The histopathological and hematological studies reveal that the after simultaneous inoculation of both ZnO NPs and bacterial suspensions (tolerated amount), no/negligible infection was found in the mice model.

The effects of alkaline pH on the size and surface characteristics of gutta-percha were studied. Forty ProTaper Universal-F2 gutta-percha cones (GPC) were stored individually for 8-weeks. GPC were distributed into 2 groups (n = 20) based on the storage solutions' pH (pH7, pH12). The GPC volume was measured after 1,2,3,4 and 8-weeks using water displacement method and compared to the baseline volume. The surfaces of representative GPCs were analysed using Raman spectroscopy and assessed later using Scanning Electron Microscopy with Energy-Dispersive X-Ray Spectroscopy (EDS). Samples t test was used to compare the change in volume of GPC and a repeated measures Analysis of Variance (ANOVA) was used to compare the effects of storage durations. After 8-weeks, GPCs aged in high-pH exhibited significant drop in their volume (16%) compared with GPCs aged in water (2.5%). The surface of GPCs stored in water or high-pH both demonstrated structural and chemical alterations in comparison with non-aged GPCs.

High salt content is one of the major problems for stewed products. To help address this issue, the effect of salt reduction on water migration in stewed ducks was investigated through diverse approaches, including water activity (Aw) and water-holding capacity (WHC) assay, as well as low-field nuclear magnetic resonance (LF-NMR) and scanning electron microscopy (SEM) observation. Our results showed that Aw value remained stable, while centrifugal loss decreased, and cooking loss increased significantly (p 0.05). The analysis of NMR indicated that, during the marinating stage, the proportion of immobilized water increased from 86.86%-89.66% (sodium chloride group) and 90.51% (salt-reduced group), respectively. After 2 h, the free water content became 0, and then became stable until the end of marinating. In the stewing stage, at the beginning 20 min, relaxation time of immobilized water decreased to about 35 ms and the ratio of immobilized water significantly reduced (p 0.05) by 5.38% (sodium chloride group) and 5.95% (salt-reduced group), respectively. Free water peak was detected upon stewing of 10 min, and 20 min later, there was no significant difference in the proportion of free water (p 0.05). In general, no significance was observed in water behavior and microstructure of stewed duck meat between the salt reduction group and sodium chloride group. In addition, SEM analysis revealed that marinating could expand the muscle fiber gap to accommodate more immobilized water. However, the fiber was looser at the initial stage of stewing and then became more compact. PRACTICAL APPLICATION: This work demonstrates potentially feasible to produce salt-reduced duck products.

In this work, piezoceramics of the lead-free composition K0.5 Na0.5 NbO3 with an increasing amount of MgNb2 O6 (0, 0.5, 1, 2 wt.%) were prepared through conventional solid-state synthesis and sintered in air atmosphere at 1100 °C. The effect of magnesium niobate addition on structure, microstructure and piezoelectric properties was evaluated. The ceramics maintain the orthorhombic Amm2 phase for all compositions, while an orthorhombic Pbcm secondary phase was found for increasing the concentration of MgNb2 O6 . Our results show that densification of these ceramics can be significantly improved up to 94.9 % of theoretical density by adding a small amount of magnesium-based oxide (1 wt.%). Scanning electron microscopy morphology of the 1 wt.% system reveals a well-packed structure with homogeneous grain size of ∼2.72 μm. Dielectric and piezoelectric properties become optimal for 0.5-1.0 wt.% of MgNb2 O6 that shows, with respect to the unmodified composition, either higher piezoelectric coefficients, lower anisotropy and relatively low piezoelectric losses (d33 =97 pC N-1 ; d31 =-36.99 pC N-1 and g31 =-14.04×10-3 mV N-1 ; Qp (d31 )=76 and Qp (g31 )=69) or enhanced electromechanical coupling factors (kp =29.06 % and k31 =17.25 %).

In this study, a new Ti3 C2 Tx -coated fiber was synthesized and utilized as coatings for solid-phase microextraction of seven polychlorinated biphenyls. The as-produced multilayered Ti3 C2 Tx MXene was characterized by X-ray diffractometer, thermos-gravimetric analysis, scanning electron microscopy, and energy dispersive spectroscopy. It is noteworthy that the Ti3 C2 Tx showed some attractive features including unique 2D layered structures, large surface area, good hydrophilicity and rich active recognition sites, endowing it has a high affinity towards the target polychlorinated biphenyls. Subsequently, the affecting parameters on the extraction efficiency of polychlorinated biphenyls were optimized. Under the optimal conditions, a novel method for the analysis of polychlorinated biphenyls in water samples was proposed. The Ti3 C2 Tx -coated fiber based solid-phase microextraction method showed good linearity (r2 > 0.9928), high enrichment factors (268-442), low limits of detection (0.06-0.15 ng L-1 ), and satisfactory repeatability (RSDs < 7.5%) for the PCBs. The excellent method recoveries were in the range of 90.0-98.4%, 92.0-98.2%, and 92.0-98.0% for river water, lake water, and tap water sample, respectively. These results suggested that the proposed Ti3 C2 Tx -coated fiber based method represents a promising alternative for the analysis of polychlorinated biphenyls. This article is protected by copyright. All rights reserved.

Bacterial infection and poor osteogenic capacity can result in the loosing or failure of titanium (Ti)-based implants in the clinic. Therefore, it is urgent to design an effective approach to enhance the osteogenic property and restrict bacterial activity. In this study, a layered double hydroxide (LDH) composed of Ga and Sr ions on Ti substrates by a hydrothermal method, then calcined in 250°C and denoted as LDH250. The scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were confirmed that the LDH films were successfully formed on the Ti substrates. Importantly, the obtained LDH films can induce an alkaline microenvironment around the Ti surface and regulate the behaviors of osteogenic cells and bacteria. In vitro cellular experiments, the LDH250 can enhance the differentiation of both MC3T3-E1 cells and osteoblasts, stimulate alkaline phosphatase activity (ALP), collagen secretion, and mineralization levels. Meanwhile, antimicrobial assay against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) demonstrated that the LDH250 samples had strong antibacterial abilities, which attributed to the release profile of Ga3+ could act as a "Trojan horse" to destroy the bacterial iron metabolism, inducing of local alkaline environment, and producing reactive oxygen species. Hence, this study provides an effective method for reducing antibacterial infection and enhancing the bone integrative capacity of Ti-based implants for orthopedic applications.

The tubule occlusion of two newly developed herbal toothpastes was examined. They were prepared based on the mixture of pomegranate peel and Equisetum arvense extracts with strontium acetate. The antimicrobial activity of pomegranate peel and E. arvense were determined using minimum inhibitory concentration (MIC). Then, 30 mid-coronal dentin discs from the human third molars were etched for 30 s with the lemon juice (pH = 2.4). The specimens divided into the three groups. While the control group had 6 specimens, Groups 1 and 2 were including 12 specimens. Group 1 brushed with toothpaste containing 10% strontium acetate and 5% hydroalcoholic extracts of pomegranate peel, and Group 2 brushed with 5% strontium acetate, 5% hydroalcoholic extracts of E. arvense, and 5% hydroalcoholic extracts of pomegranate peel. Brushing was simulated for 6 months with 2 N loading. Then, 50% of discs in each group were immersed in lemon juice for 1 min. Moreover, specimens in control group were brushed with distilled water. Finally, all 30 discs were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDXS). The occluded dentin tubules were counted and statistically evaluated. It was found that the number of open dentin tubules decreases significantly after brushing with both tested toothpastes compared with control group (p < .001). Moreover, a significant difference was observed between two toothpastes before and after acid immersion process (p < .001). The SEM micrographs confirmed the dentin tubule occlusion of both herbal dentifrices. Besides, EDXS analysis approved the strontium and silica presence on the dentin tubules for the toothpaste which was based on E. arvense.

Hydroxyapatite (HA) co-doped with La3+ and F- ions were synthesized by the precipitation method and sintered at 1,100°C for 1 hr. Samples were characterized by the standard experimental methods including the density, X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) to investigate their microstructure, phase formation, and bonding characteristics in detail. Moreover, the materials produced were identified using the microhardness tests. It was observed that in the most of materials, the hydroxyapatite was found to be the main phase with a minor amount of β-tricalcium phosphate (β-TCP). Furthermore, the presence of fluoride and small amount of β-TCP was verified with all the characteristic FTIR bands of hydroxyapatite for the majority of samples studied. The result in SEM evaluation is that the produced HA powders have less deformed, uniformly distributed, and regularly shaped particles. Here, the material density has changed towards a less dense state with the increasing rate of La doping, but statistically significant difference was not obtained (p, .1942 > .05) with increase of the F doping. A significant difference was obtained the microhardness values between La3+ and F- ions co-doped HA materials and pure HA (p [.0053]

The scale morphology of a native goby, Awaous jayakari (Gobiidae) was studied using scanning electron microscopy and light microscopy. The morphological descriptions were based on the scale's type, shape, and features of the anterior, posterior, and lateral fields. Further characteristics of the focus, circuli, radii, lepidonts, and cteni, were investigated. Morphometric indices were calculated for some scales. Shape variability of scales was high in different regions. However, the majority of scales displayed a polygonal shape (hexagonal and pentagonal). Both ctenoid and cycloid scales were observed in the studied fishes. The ctenoid scale of A. jayakari was peripheral and characterized by the presence of one row of marginally located spines in two completed and uncompleted subtypes. The focus was positioned posteriorly or postero-centrally. The microscopic examinations revealed the presence of lepidonts of different sizes being very tiny, small, or prominent performing flat, blunt, pointed, short, or truncated shapes. The rostral margin of the scales was convex to moderately flattened and represented striate, scalloped, or waved types. Lateral fields were often flattened in all regions, while convex in the lateral fields of the scales of some individuals. The posterior field showed variations in different regions, for example, tapered and flattened ends. The anterior-posterior axis presented a laterally expanded or an elongated extension. The considerable morphological variation in the scales of various body regions makes it difficult to nominate a typical scale to be used in taxonomic studies. However, the key scales can be used for the comparison of different Awaous species.

An open tubular capillary electrochromatography column was prepared by immobilizing β-cyclodextrin on the inner wall of pretreated capillary via noncovalent adsorption of polydopamine. The resulting coating layer on the capillary was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Electroosmotic flow was studied to evaluate the variation of the immobilized columns. The prepared columns showed good chiral separation performance toward five proton pump inhibitors including lansoprazole, pantoprazole, tenatoprazole, rabeprazole, and omeprazole. The influences of β-cyclodextrin concentration, coating time, buffer pH, buffer concentration, and applied voltage on separation were investigated. In the optimum conditions, the enantiomers of five analytes were fully resolved within 15 min with high resolutions of 4.57 to 8.13. The method was extensively validated in terms of accuracy, precision, and linearity and proved to be robust. The relative standard deviation values for migration times and peak areas of the analytes representing intraday and interday were less than 1.9 and 3.6%, respectively. Further, the polydopamine/β-cyclodextrin coated capillary column could be successively used over 100 runs without showing significant decrease in the separation efficiency.

This paper describes the compositional, mechanical, and structural differences between collagen gels fabricated from different sources and processing methods. Despite extensive use of collagen in the manufacturing of biomaterials and implants, there is little information as to the variation in properties based on collagen source or processing methods. As such, differences in purity and composition may affect gel structure and mechanical performance. Using mass spectrometry, we assessed protein composition of collagen from seven different sources. The mechanics and gelation kinetics of each gel were assessed through oscillatory shear rheology. Scanning electron microscopy enabled visualization of distinct differences in fiber morphology. Mechanics and gelation kinetics differed with source and processing method and were found to correlate with differences in composition. Gels fabricated from telopeptide-containing collagens had higher storage modulus (144 vs. 54 Pa) and faster gelation (251 vs. 734 seconds) compared to atelocollagens, despite having lower purity (93.4 vs 99.8%). For telopeptide-containing collagens, as collagen purity increased, storage modulus increased, and fiber diameter decreased. As α1/α2 chain ratio increased, fiber diameter increased, and gelation slowed. As such, this study provides an examination of the effects of collagen processing on key quality attributes for use of collagen gels in biomedical contexts.

Compression molded composites were prepared through a water-assisted mixing of an aqueous suspension of poly(ethylene-co-acrylic acid), additive,and pulp fibers [thermomechanical pulp (TMP) or dissolving pulp (DP)]. The lubricating additives used were magnesium stearate (MgSt) and molybdenum disulphide (MoS2). The composite materials had dry pulp contents ranging from 30 to 70 wt% and 5 wt% additive relative to the weight of the pulp. The adsorption of the additives onto the fibers was confirmed by scanning electron microscopy and energy dispersive X-ray analysis. DMA showed that MgSt and MoS2 gave similar interphase properties for the TMP samples at all loading contents, but the combination of MgSt and MoS2 improved the overall properties of the DP-based composites. The tensile modulus, at 70 wt% fiber content (TMP or DP), increased compared to the matrix by a factor of 6.3 and 8.1, without lubricants, and by a factor of 8 and 10.7, with lubricants, respectively. The increase in melt viscosity observed for the lubricated samples was greater for the TMP-based samples containing MoS2. At a lubricant content of 5 wt%, in 30 wt% TMP, the MoS2 behaved as both a lubricant and compatibilizer.