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A new 14-membered resorcylic acid lactone (RAL14), chaetolactone A (1), along with three known ones (2−4), was obtained from the fermentation of the soil-derived fungus Chaetosphaeronema sp. SSJZ001. Their structures were established based on extensive spectroscopic data analyses (UV, IR, HRESIMS, 1D, and 2D NMR),13C NMR chemical shifts calculations coupled with the DP4+ probability method, theoretical calculations of ECD spectra, as well as X-ray diffraction analysis. All compounds were evaluated for their cytotoxic effects against A549, HO-8910, and MCF-7 cell lines. [ABSTRACT FROM AUTHOR]

Polyether ether ketone (PEEK) is a biocompatible material that lacks antimicrobial activity and bioactivity; therefore, is not appropriate for use as a dental implant. To overcome these deficiencies, a novel composite coating of bioactive glass and graphene oxide was prepared. PEEK discs were polished, cleaned, and the surface treated with sulfuric acid for 15 min. The composite coating consisted of bioactive glass produced by the sol‐gel route and doped with 0.75 wt% graphene oxide. X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy‐energy dispersive spectroscopy analyses were employed to characterize the composite coating, and the coating adhesion strength quantified using a pull‐off test. Cytotoxicity was assessed using osteoblast‐like cells and gingival fibroblasts. The wettability of the coated and non‐coated samples was determined by optical contact angle assessment, and bioactivity was assessed by immersion in simulated body fluid. The results revealed that the bioactive glass/graphene oxide composite coating, approximately 7 μm thick, was transparent, homogenous with few microcracks and microporosities, but adhered strongly and was not cytotoxic to either osteoblast‐like cells or gingival fibroblasts. The wettability of the PEEK sample was increased to <20° after coating with the composite, and apatite formation was detectable after 14 days of immersion in simulated body fluid. [ABSTRACT FROM AUTHOR]

Objective: This investigation evaluated the effect of two sintering modes of a translucent zirconia (Y‐TZP) on its surface roughness, topography, phase‐transformation (t → m), translucency and biaxial flexure fatigue strength. Materials and Methods: To do so, 50 Y‐TZP discs (Ø = 15 mm; thickness = 1.2 mm; IPS e.max ZirCAD LT) were prepared and divided into two groups: Standard mode (SM) and Fast mode (FM). Staircase fatigue testing was performed (piston‐on‐three balls set‐up, ISO 6872:2015), as well as surface roughness, profilometry, scanning electron microscopy (SEM‐FEG), energy dispersive X‐ray spectroscopy (EDX), phase transformation (t → m) using X‐ray diffraction analysis (XRD), translucency parameter analysis (TP and TP00) and fractography. Results: The results showed no statistical significant differences for roughness parameters (p > 0.05, SM: Ra = 0.13 ± 0.02, Rz = 1.21 ± 0.26 and RSm = 24.91 ± 2.19; FM: Ra = 0.14 ± 0.03, Rz = 1.32 ± 0.25 and RSm = 24.68 ± 2.16) or flexural fatigue strength (SM: 512 (464–560) MPa; FM: 542 (472–611) MPa) between the groups. In addition, similarity in surface morphological features (SEM and profilometry), composition and phases (EDX and XRD) was observed between the firing protocols. Fractography showed that the failure origin occurred on the tensile side. Sintering mode did not affect the TP (F = 0.001, p = 0.97) and TP00 (F = 0.12, p = 0.72). Conclusions: Therefore, the fast‐sintering mode is suggested as a viable alternative to the standard mode since it does not influence the evaluated surface morphology, microstructure, fatigue strength and translucency of a translucent monolithic zirconia. Clinical Significance: The fast sintering mode is a viable alternative for zirconia without compromising its topography, microstructure, mechanical performance or translucency. [ABSTRACT FROM AUTHOR]

Simple Summary: Radiation-based anticancer therapies are often ineffective as cancer cells may acquire radioresistance. Moreover, such therapies can cause unwanted side effects, affecting normal tissues. This problem may be remedied by the use of nanometric radiosensitizers. These compounds in non-toxic concentrations improve the effectiveness of therapy while reducing the total dose of radiation used. In this work, we checked the radiosensitizing properties of bimetallic palladium-platinum nanoparticles with different nanostructures: nano-alloy and core-shell. It has been found that nano-alloy structures are more promising radiosensitizers in vitro, and their effect is more satisfactory when using X-rays than high-energy protons. Thus, by appropriately designing the microstructure of nanomaterials, it is possible to modulate their radiosensitizing potential and enhance the therapy′s effectiveness. Nano-sized radiosensitizers can be used to increase the effectiveness of radiation-based anticancer therapies. In this study, bimetallic, ~30 nm palladium-platinum nanoparticles (PdPt NPs) with different nanostructures (random nano-alloy NPs and ordered core-shell NPs) were prepared. Scanning transmission electron microscopy (STEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDS), zeta potential measurements, and nanoparticle tracking analysis (NTA) were used to provide the physicochemical characteristics of PdPt NPs. Then, PdPt NPs were added to the cultures of colon cancer cells and normal colon epithelium cells in individually established non-toxic concentrations and irradiated with the non-harmful dose of X-rays/protons. Cell viability before and after PdPt NPs-(non) assisted X-ray/proton irradiation was evaluated by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Flow cytometry was used to assess cell apoptosis. The results showed that PdPt NPs significantly enhanced the effect of irradiation on cancer cells. It was noticed that nano-alloy PdPt NPs possess better radiosensitizing properties compared to PtPd core-shell NPs, and the combined effect against cancer cells was c.a. 10% stronger for X-ray than for proton irradiation. Thus, the radio-enhancing features of differently structured PdPt NPs indicate their potential application for the improvement of the effectiveness of radiation-based anticancer therapies. [ABSTRACT FROM AUTHOR]

A new aromatic glycoside (1) and twelve (2–13) known aromatic glycosides were isolated from the n-butyl alcohol of the 70% EtOH extract of the aerial part of Bupleurum chinense. Among them, compounds 4–7, 9, 11–13 were isolated from Umbelliferae plants for the first time. Their structures were elucidated by NMR and MS spectroscopy, and the absolute configuration of compound 1 was elucidated by single-crystal X-ray diffraction. Compounds 6 and 10 showed moderate cytotoxic activities on MGC-803 cell lines with IC50 values of 8.63 ± 0.08 and 13.65 ± 1.73 μM, respectively. [ABSTRACT FROM AUTHOR]

Four new ionones and ionone glycosides (1–4) were isolated from the whole plant of Rehmannia piasezkii Maxim. Their planar structures as well as absolute configuration were confirmed via spectroscopic analysis, ECD calculation, and X-ray crystallography. Compounds 1–4 were tested for their cytotoxicity against five human tumor cell lines and ability to inhibit LPS-activated NO production in the BV2 cell line. [ABSTRACT FROM AUTHOR]

Phytochemical investigations of the twig and leaf extracts of Uvaria dac Pierre ex Finet & Gagnep. resulted in the isolation and identification of five new highly oxygenated cyclohexenes, uvaridacols M − Q (1 – 3 , 5 , and 6), and six known compounds (4 and 7 – 11). All new structures were elucidated by spectroscopic methods and HRESITOFMS data. The absolute configuration of 1 , 5 , and 6 was confirmed by single X-ray diffraction analysis with Cu Kα radiation. In contrast, other compounds were established by comparing their specific rotation and ECD spectra with those of known compounds. Some of the isolated compounds with sufficient quantity were evaluated for their α-glucosidase inhibitory activity. Of these, (−)-1,6-desoxypipoxide (10) showed α-glucosidase inhibitory activity with an IC 50 value of 28.6 μM. The in silico molecular docking of active compounds was also studied. Phytochemical investigations of the twig and leaf extracts of Uvaria dac Pierre ex Finet & Gagnep. resulted in the isolation and identification of five new highly oxygenated cyclohexenes and six known compounds. Some of the isolated compounds with sufficient quantity were evaluated for their α-glucosidase inhibitory activity. Of these, (−)-1,6-desoxypipoxide (10) showed α-glucosidase inhibitory activities with an IC 50 value of 28.6 μM. [Display omitted] • Five new oxygenated cyclohexenes were isolated from Uvaria dac. • The absolute configuration of uvaridacol M, P, Q were confirmed by single X-ray diffraction analysis with Cu Kα radiation. • Oxygenated cyclohexenes containing a cinnamoyl moiety, such as uvaridacols N and P first reported here. • 1,6-Desoxypipoxide showed α -glucosidase inhibitory activity. • 1,6-Desoxypipoxide was docked into α -glucosidase (PDB ID: 2QMJ) in silico molecular docking. [ABSTRACT FROM AUTHOR]

An extensive phytochemical investigation on the rare medicinal plant Semiliquidambar cathayensis (family: Hamamelidaceae) led to the isolation of four new (1 – 4 , named semiliquidacids A–D, respectively) and 25 related known pentacyclic triterpenoids. The new structures with absolute configurations were elucidated by spectroscopic methods, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction analysis. Compound 1 represents the first naturally occurring ursane-type triterpenoid featuring an uncommon C-25 formyl group. Compound 4 and oleanolic acid (13) exhibited remarkable inhibitory effects against the ATP-citrate lyase (ACL, an emerging drug target for hyperlipidemia and related metabolic disorders) with IC 50 values of 6.5 and 11.9 μM, respectively. The molecular interaction and binding mode between the bioactive triterpenoids and ACL were elaborated by conducting a molecular docking study. Meanwhile, the chemotaxonomic significance of the isolated triterpenoids has been briefly discussed. [Display omitted] • The rare medicinal plant Semiliquidambar cathayensis was phytochemically investigated. • Four new and twenty-five related known pentacyclic triterpenoids were reported. • Semiliquidacid A is a rare ursane-type triterpenoid featuring a C-25 formyl group. • Semiliquidacid D and oleanolic acid significantly inhibited the ATP-citrate lyase. • A molecular docking study was performed to provide an insight into the binding site. [ABSTRACT FROM AUTHOR]

Three Stemona alkaloids named stemotuberines A–C (1 – 3) with unique C 17 N frameworks, presumably formed by elimination of the C-11–C-15 lactone ring of the stichoneurine skeleton, were isolated from the roots of Stemona tuberosa. Their structures were elucidated by spectroscopic analysis, X-ray diffraction, and computational methods. Compounds 2 and 3 showed inhibition (IC 50 values of 37.1 and 23.2 μM, respectively) against LPS-induced nitric oxide production in RAW 264.7 cells. In addition, concern was expressed about the reported plant origin (S. sessilifolia) of the recently described alkaloids tuberostemonols O–R (4–7), which should be S. tuberosa. NMR calculations indicated structural misassignment of these compounds except for 6. Isolation of tuberostemonol P (5) from our material of S. tuberosa allowed for a close examination of the spectroscopic data leading to the revised structure 5a. Tuberostemonol R (7) was found to have identical 1H and 13C NMR data to the well-known alkaloid croomine, and therefore its structure including relative stereochemistry must be revised as 7a. [Display omitted] • Three previously undescribed Stemona alkaloids were isolated from Stemona tuberosa. • Compounds 1 – 3 possess unprecedented C 17 N skeletons. • Nitric oxide inhibitory activities of isolated compounds were evaluated. • Putative structures of tuberostemonols P and R were revised. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the EtOAc soluble fraction from leaves of Trichilia dregeana Sond. (Meliaceae) afforded naturally rare four new pentacyclic triterpenoids (1 – 4), together with five known pentacyclic analogs (5 – 8 , and 11) and two steroids (9 and 10). Their structures were elucidated by extensive spectroscopic techniques such as 1D and 2D NMR and HRESIMS data analyses. The absolute configuration of 1 was determined by using the single-crystal X-ray diffraction analysis. The nitric oxide (NO) production inhibitory assay indicated that the EtOAc fraction as well as 4 and 7 inhibited the NO production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells with the IC 50 values of 83.53 μg/mL and 81.31 and 85.71 μM, respectively. Compounds 1 – 4 are rare 19(10 → 9) abeo -euphane-type triterpenoids bearing a 3,10-ether bridge. To the best of our knowledge, this study is the first isolation of triterpenoids with the 3,10-ether bridge in their skeleton from the genus Trichilia , providing new insights into the chemodiversity of the terpenoids in T. dregeana. [Display omitted] [ABSTRACT FROM AUTHOR]

Phytochemical investigation on the extract of endophytic fungus Tolypocladium sp. SHJJ1 resulted in the identification of a pair of previously undescribed pyridoxatin atropisomers [ 1 ( M / P )] and three new indole diterpenoids (3 – 5), together with a pair of known pyridoxatin atropisomers [ 2 ( M / P )] and ten known indole diterpenoids (6 –1 5). Their structures, including their absolute configurations were elucidated by extensive spectroscopic analysis, quantum chemical calculations, and X - ray diffraction. Among the undescribed natural products, [ 1 ( M / P )] that two rapidly interconverting atropisomers are the third example to report in the pyridoxatin atropisomers. Except for compounds 1 ( M / P ) and 2 ( M / P ), all other compounds were tested for their cytotoxicity using HepG2, A549, and MCF-7 human cell lines. Compound 9 displayed moderate cytotoxicity against the HepG2, A549, and MCF-7 cell lines with IC 50 values of 32.39 ± 1.48 μM, 26.06 ± 1.14 μM, and 31.44 ± 1.94 μM, respectively, which was similar to the positive drug cisplatin (with IC 50 values of 32.55 ± 1.76 μM, 18.40 ± 1.43 μM, and 27.31 ± 1.22 μM, respectively). [Display omitted] [ABSTRACT FROM AUTHOR]

A phytochemical investigation on the buds of edible medicinal plant, Eugenia carvophyllata , led to the discovery of seven new compounds, caryophones A–G (1 – 7), along with two biogenetically-related known ones, 2-methoxy-7-methyl-1,4-naphthalenedione (8) and eugenol (9). Compounds 1 – 3 represent the first examples of C-5–C-1′ connected naphthoquinone-monoterpene adducts with a new carbon skeleton. Compounds 4 – 7 are a class of novel neolignans with unusual linkage patterns, in which the C-9 position of one phenylpropene unit coupled with the aromatic core of another phenylpropene unit. The chemical structures of the new compounds were determined based on extensive spectroscopic analysis, X-ray diffraction crystallography, and quantum-chemical calculation. Among the isolates, compounds (−)- 2 , 3 , 6 , and 9 showed significant in vitro inhibitory activities against respiratory syncytial virus (RSV)-induced nitric oxide (NO) production in RAW264.7 cells. [Display omitted] [ABSTRACT FROM AUTHOR]

Four undescribed ginkgolides, including two rare sesquiterpene ginkgolides (compounds 1 and 2) and two diterpenoid ginkgolides (compounds 3 and 4) , were isolated from Ginkgo biloba L. The structures of these four ginkgolides were identified based on extensive spectroscopic analysis, DP4+ probability analysis and X-ray diffraction. Compounds 1 and 2 exhibited excellent antiplatelet aggregation activities with IC 50 values of 1.20 ± 0.25 and 4.11 ± 0.34 μM, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: The present study was aimed at phyto-synthesized silver nanoparticles (AgNPs) using Amygdalus spinosissima ( A. spinosissima) extract and to investigate the antibacterial, antioxidant effects, anticancer and apoptotic effects of phyto-synthesized AgNPs. Methods: The bio-fabricated AgNPs were characterized using UV-visible spectroscopy (UV-visible), X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX). Results: The phyto-synthesized AgNPs showed maximum absorption in 438 nm, in the UV-visible spectrum. XRD peaks were observed at 2θ values in 38.20°, 44.40°, 64.60°, and 77.50° which are indexed as (111), (200), (220), and (311) bands of Face-Centered Cubic (FCC) structures of silver. FTIR analysis indicated that the AgNPs were capped with A. spinosissima extract. SEM and TEM micrographs revealed that the fabricated AgNPs were spherical and the average size range was 17.89 nm. Also, the EDX results show that the content of Ag was 90%. Conclusion: The phyto-synthesized AgNPs had significant antibacterial activity against Gram-negative bacteria, as well as, the AgNPs exhibited great inhibitory effects on DPPH radicals and their antioxidant properties were favorably comparable to the antioxidant outcomes of ascorbic acid. Moreover, the AgNPs showed anticancer activity against the MCF-7 cell line with the IC50=6.1 µg/ml. Moreover, the phyto- synthesized AgNPs could induce apoptosis in the MCF-7 cell line significantly. The GC-MS analysis of the A. spinosissima extract showed that 102 bioactive phytochemical compounds, which be of use to the synthesis of AgNPs. [ABSTRACT FROM AUTHOR]

A comparison of the analysis of respirable crystalline silica direct-on-filter methods using X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy was undertaken using 253 real workplace air samples from road construction and tunnelling, coal mining, and kitchen benchtop manufacturing in Australia. Using pure α-quartz standards, XRD and FT-IR direct-on-filter analyses produced identical test results, however, the real workplace samples showed a clear discrepancy between FT-IR and XRD results with on average a 9% positive bias of the FT-IR results. The cause of the positive bias was due to matrix interferences which was confirmed by using synthetic mixture air samples. Approximately a third of the data by direct-on-filter method using FT-IR was assessed to be invalid based on the peak height ratio criterion due to excessive interferences and weight overload limitations. The XRD method showed better results due to less interference from the common matrices. XRD could handle up to twice the sample loading and at higher loadings up to 7 mg when a correction was applied. It was also able to achieve a lower limit of detection of 2 µg filter−1 when a slower scan condition was utilized. [ABSTRACT FROM AUTHOR]

Five new Erythrina alkaloids and five known E. alkaloids were isolated from a 95% ethanol extract of the stems of Erythrina corallodendron L. Their chemical structures were elucidated by UV, IR, HRESIMS, NMR and X-ray. Furthermore, the analgesic activities of E. alkaloids 1, 2 and 6 were evaluated by using an acetic acid-induced writhing test in mice, and their writhing inhibition rates were 67.9%, 64.6% and 70.3% at doses of 20 mg/kg, respectively. [ABSTRACT FROM AUTHOR]

Background: Growing investigations demonstrate that graphene oxide (GO) has an undeniable impact on repairing damaged bone tissue. Moreover, it has been stated in the literatures that poly(2-hydroxyethyl methacrylate) (PHEMA) and gelatin could provide a biocompatible structure. Methods: In this research, we fabricated a scaffold using freeze-drying method comprised of PHEMA and gelatin, combined with GO. The validation of the successful fabrication of the scaffolds was performed utilizing Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction assay (XRD). The microstructure of the scaffolds was observed using scanning electron microscopy (SEM). The structural properties of the scaffolds including mechanical strength, hydrophilicity, electrical conductivity, and degradation rate were also evaluated. Human bone marrow‐derived mesenchymal stem cells (hBM-MSCs) were used to evaluate the cytotoxicity of the prepared scaffolds. The osteogenic potential of the GO-containing scaffolds was studied by measuring the alkaline phosphatase (ALP) activity after 7, 14, and 21 days cell culturing. Results: SEM assay showed a porous interconnected scaffold with approximate pore size of 50–300 μm, appropriate for bone regeneration. The increase in GO concentration from 0.25 to 0.75% w/v exhibited a significant improvement in scaffolds compressive modulus from 9.03 ± 0.36 to 42.82 ± 1.63 MPa. Conventional four-probe analysis confirmed the electrical conductivity of the scaffolds in the semiconductor range. The degradation rate of the samples appeared to be in compliance with bone healing process. The scaffolds exhibited no cytotoxicity using MTT assay against hBM-MSCs. ALP analysis indicated that the PHEMA–Gel–GO scaffolds could efficiently cause the differentiation of hBM-MSCs into osteoblasts after 21 days, even without the addition of the osteogenic differentiation medium. Conclusion: Based on the results of this research, it can be stated that the PHEMA–Gel–GO composition is a promising platform for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Two novel fungal polyketides, phometides A (1) and B (2), together with four known compounds (3–6), were isolated from the endophytic fungus Phoma sp. YUD17001 obtained from Gastrodia elata Blume. The structures were elucidated based on spectroscopic analyses, X-ray crystal diffraction, and time-dependent density functional theory/electronic circular dichroism (TDDFT/ECD) calculations. Structurally, phometide A (1) represented the first example of C 12 polyketide characterized by an unusual tetrahydrobenzofuran-3(2 H)-one core with an α , β -unsaturated ketone functionality, while phometide B (2) was an unprecedented molecule containing a 2-pentylcycloheptan-1-one scaffold. In an antimicrobial activity assay, phometide A (1) exhibited significant inhibitory activity against Staphylococcus aureus with MIC value of 4 μg/mL. Phometide B (2) showed moderate antifungal activity against Candida albicans with an MIC value of 16 μg/mL. Furthermore, compounds 1 and 2 were evaluated for their acetylcholinesterase inhibitory and cytotoxic activities. [Display omitted] • Two novel fungal polyketides were identified from the endophytic fungus Phoma sp. YUD17001. • Phometide A possess an unusual tetrahydrobenzofuran-3(2 H)-one functionality. • Phometide B is a novel polyketone containing a 2-pentylcycloheptan-1-one scaffold. • Phometides A and B demonstrated antimicrobial activity against S. aureus and C. albicans , respectively. [ABSTRACT FROM AUTHOR]

Distraction osteogenesis (DO) is an efficient strategy that is employed for the treatment of large bone defects in craniomaxillofacial surgery. Despite its utility, however, DO is associated with a prolonged consolidation phase and a high complication rate that hinder its more widespread utilization. Panax notoginseng saponin (PNS) is a traditional Chinese medicine that is frequently administered for the treatment of a range of conditions. Herein, we explored the ability of PNS treatment to influence osteogenic differentiation using both rabbit bone marrow mesenchymal cells (BMSCs) and a model of mandibular DO. BMSC proliferation was assessed via CCK-8 assay, while osteogenic differentiation was monitored through ALP and alizarin red S staining. A PCR approach was used to evaluate the expression of genes associated with osteogenesis (ALP, Runx2, and OCN) and genes linked to the TGF pathway (TβR-II, SMAD2, SMAD3, and PPM1A). For in vivo experiments, treated BMSCs were locally injected into the DO gap, with PNS being injected into treated rabbits every other day throughout the experimental period. The quality of the regenerative process was assessed via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray imaging, and hematoxylin and eosin (H&E) staining. These analyses revealed that PNS was able to promote BMSC osteogenesis and mandibular generation, driving the upregulation of osteogenesis-related genes at the mRNA levels through the modulation of the TGF-β1/Smad pathway. Consistently, the overexpression or silencing of TβR-II in PNS-treated BMSCs was sufficient to modulate their osteogenic potential. Analyses of in vivo mandibular DO outcomes revealed significantly augmented new bone growth in the PNS-treated group relative to control animals, with maximal osteogenesis in the group overexpressing rabbit TβR-II. Together, these results highlight the PNS as a promising and cost-effective therapeutic tool with the potential to enhance bone regeneration in clinical contexts through the modulation of the TGF-β1/Smad pathway. [ABSTRACT FROM AUTHOR]

This study was aimed at fabricating and evaluating the physical and bioproperties of nanofast cement (NFC) as a replacement of the MTA. The cement particles were decreased in nanoscale, and zirconium oxide was used as a radiopacifier. The setting time and radiopacity were investigated according to ISO recommendations. Analysis of color, bioactivity, and cytotoxicity was performed using spectroscopy, simulated body fluid (SBF), and MTT assay. The setting time of cement pastes significantly dropped from 65 to 15 min when the particle sizes decreased from 2723 nm to 322 nm. Nanoparticles provide large surface areas and nucleation sites and thereby a higher hydration rate, so they reduced the setting time. Based on the resulting spectroscopy, the specimens did not exhibit clinically noticeable discoloration. Resistance to discoloration may be due to the resistance of zirconium oxide to decomposition. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (FTIR) examinations of the immersed SBF samples showed apatite formation that was a reason for its suitable bioactivity. The results of cell culture revealed that NFC is nontoxic. This study showed that NFC was more beneficial than MTA in dental restorations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effect of calcium hydroxide [Ca(OH)2] on dentine composition and root fracture resistance. Root canals of fifty extracted mandibular premolars were prepared and divided into five groups (N = 10). Canals were filled with non‐setting Ca(OH)2 or left empty and were subsequently stored in phosphate buffered saline for 7, 14, 30, or 90 days, respectively. Ca(OH)2 was then washed out, and roots were separated from the crowns and subjected to fracture strength test. Fractured fragments were examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD). The results showed a significant and progressive reduction in fracture resistance the longer the duration of exposure to Ca(OH)2, and the fracture resistance in teeth exposed for 90 days was significantly lower than in any other group. SEM revealed cracks in the dentine surfaces that had been exposed to Ca(OH)2. FTIR showed a significantly lower mineral to matrix ratio in roots exposed to Ca(OH)2 for 30 and 90 days than seen in roots exposed for a shorter duration. XRD analysis revealed a reduction in dentine crystallinity. It was concluded that Ca(OH)2 significantly reduced the fracture resistance of the roots overtime. Exposure to Ca(OH)2 reduced the mineral to matrix ratio and crystallinity of the dentine. [ABSTRACT FROM AUTHOR]

We present a new open‐source software for the integration of the radial Dirac equation developed specifically with muonic atoms in mind. The software, called mudirac, is written in C++ and can be used to predict frequencies and probabilities of the transitions between levels of the muonic atom. In this way, it provides an invaluable tool in helping with the interpretation of muonic X‐ray spectra for elemental analysis. We introduce the details of the algorithms used by the software, show the interpretation of a few example spectra and discuss the more complex issues involved with predicting the intensities of the spectral lines. The software is available publicly at https://github.com/muon-spectroscopy-computational-project/mudirac. [ABSTRACT FROM AUTHOR]

Biocellulose or bacterial cellulose (BC) is a biocompatible (nano) material produced with a threedimensional network structure composed of microfibrils having nanometric diameters obtained by the Gluconacetobacter xylinus bacteria. BC membranes present relatively high porosity, allowing the incorporation or synthesis in situ of inorganic nanoparticles for multifunctional applications and have been used as flexible membranes for incorporation of magnetic nanocomposite. In this work, highly stable superparamagnetic iron oxide nanoparticles (SPION), functionalized with polyethylene glycol (PEG), with an average diameter of 5 nm and a saturation magnetization of 41 emu/g at 300K were prepared. PEG-Fe2O3 hybrid was dispersed by mixing a pristine BC membrane in a stable aqueous dispersion of PEG-SPION. The PEG chains at PEG-SPION's surface provide a good permeability and strong affinity between the BC chains and SPION through hydrogen-bonding interactions. PEG-SPION also allow the incorporation of higher content of nanoparticles without compromising the mechanical properties of the nanocomposite. Structural and magnetic properties of the composite have been characterized by XRD, SEM, energy-dispersive X-ray spectroscopy (EDX), magnetization, Raman spectroscopy, and magnetic force microscopy. [ABSTRACT FROM AUTHOR]

Nitrocellulose with silver nanoparticle (AgNP/NC) composite was prepared in situ using Ag(CH3CO2) and nitrocellulose without any reducing agent. The composite materials synthesized were spray coated onto glass substrates to obtain thin films. The AgNPs/NC composites were characterized by ultraviolet-visible, Fourier transform infrared, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The antimicrobial activity of AgNPs/NC composite was investigated by tube method and time-kill kinetic studies against three microbial species, including Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), and Candida albicans (ATCC 10231). The antibiofilm activities were qualitatively determined against all three organisms. Prepared AgNPs/NC films exhibited good antimicrobial activity and significant inhibition of biofilm development against all three microbial species. The effective dispersion of AgNPs/NC in biofilm was responsible for the significant antibiofilm activity of the prepared material. The reported AgNPs/NC composite can be used as coating additive in bacteriocidal paint which can be applied onto surfaces such as in healthcare environments. [ABSTRACT FROM AUTHOR]

NGC 5548 was recently monitored intensively from NIR to X-rays as part of the STORM campaign. Its disc emission was found to lag behind the observed X-rays, while the measured time lag was increasing with wavelength. These results are consistent with the assumption that short-term variability in AGN emission is driven by the X-ray illumination of the accretion disc. In this work, we studied the power spectrum of UV/optical and X-ray emission of NGC 5548, using the data of the STORM campaign as well as previous Swift data, in order to investigate the relation between the UV/optical and X-ray variability and to examine its consistency with the above picture. We demonstrate that even the power spectrum results are compatible with a standard disc being illuminated by X-rays, with low accretion rates, but the details are not entirely consistent with the results from the modelling of the 'τ versus λ' relation. The differences indicate that the inner disc might be covered by a 'warm corona' which does not allow the detection of UV/optical emission from the inner disc. Finally, we found strong evidence that the UV emission of NGC 5548 is not stationary. [ABSTRACT FROM AUTHOR]

Pump–probe experiments at synchrotrons and free‐electron lasers to study ultrafast dynamics in materials far from equilibrium have been well established, but techniques to investigate equilibrium dynamics on the nano‐ and pico‐second timescales remain underdeveloped and experimentally challenging. A promising approach relies on a double‐probe X‐ray speckle visibility spectroscopy setup at split‐and‐delay beamlines of X‐ray free‐electron lasers. However, the logistics in consistently producing two collinear, perfectly overlapping pulses necessary to conduct a faithful experiment is difficult to achieve. In this paper, a method is introduced to extract contrast in the case where an angular misalignment and imperfect overlap exists between the two pulses. Numerical simulations of a dynamical system show that contrast can still be extracted for significant angular misalignments accompanied by partial overlap between the two pulses. [ABSTRACT FROM AUTHOR]

Experimental observation of the hybridization of oxygen p states with metal states at the interface in Fe/MgO core/shell self-assembled nanostructures, obtained by vapour-phase deposition, is reported. Synchrotron-based X-ray absorption spectroscopy techniques were used to directly probe the Fe orbital character at the interfacial region. O K edge features suggest the formation of metal-induced states within the band gap of MgO. Thermogravimetric analysis was also used to track interfacial phase changes after different annealing processes. These data demonstrate the relevant role of annealing protocols in controlling the barrier interface, which determine the actual characteristics of spin polarized tunnelling conduction processes. [ABSTRACT FROM AUTHOR]

Direct quantitative measurements of nanoscale dynamical processes associated with structural relaxation and crystallization near the glass transition are a major experimental challenge. These type of processes have been primarily treated as macroscopic phenomena within the framework of phenomenological models and bulk experiments. Here, we report x-ray photon correlation spectroscopy measurements of dynamics at the crystal-melt interface during the radiation induced formation of Se nano-crystallites in pure Se and in binary AsSe4 glass-forming liquids near their glass transition temperature. We observe a heterogeneous dynamical behaviour where the intensity correlation functions g2(q, t) exhibits either a compressed or a stretched exponential decay, depending on the size of the Se nano-crystallites. The corresponding relaxation timescale for the AsSe4 liquid increases as the temperature is raised, which can be attributed to changes in the chemical composition of the melt at the crystal-melt interface with the growth of the Se nano-crystallites. [ABSTRACT FROM AUTHOR]

Background: In recent years, the method of constructing and evaluating the properties of polymer nanocomposite and bioactive ceramics in tissue engineering such as biocompatible scaffolds was studied by some researchers. Methods: In this study, the bio-nanocomposite scaffolds of Chitosan (CS)--Hydroxyapatite (HA)--Wllastonite (WS), incorporated with 0, 10, 20 and 30 wt% of zirconium were produced using a freeze-drying method. Also, the phase structure and morphology of scaffolds were investigated using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). By analyzing the SEM images, the porosity of the scaffolds was observed in the normal bone area of the body. In the next step, bioactivity and biodegradability tests of the scaffolds were carried out. Due to the presence of hydrophilic components and the high-water absorption capacity of these materials, the bio-nanocomposite scaffolds were able to absorb water properly. After that, the mechanical properties of the scaffolds were studied. Results: The mechanical test results showed that the preparation of reinforced bionanocomposites containing 10 wt% of zirconium presented better properties compared to incorporated bio-nanocomposites with different loadings of zirconium. Conclusion: According to MTT assay results, the prepared scaffolds did not have cytotoxicity at different concentrations of scaffold extracts. Consequently, the investigated scaffold can be beneficial in bone tissue engineering applications because of its similarity to natural bone structure and its proper porosity. [ABSTRACT FROM AUTHOR]

We present the results of X-ray spectral-timing analysis of a 90 ks XMM–Newton observation of the nearby, broad-line, early-type AGN NGC5273. The X-ray spectrum revealed the clear presence of a reflection component at high energies, with a clear signature of a narrow iron line at 6.4 keV, consistent with distant reflection. Applying a relativistic reflection model, we found only marginal evidence for a broader relativistic line component. However, cross-spectral analysis revealed that, between 4 and 6 × 10−4 Hz, the 5–8 keV band lagged the 2–3 keV band, implying reflection of the iron line from material close to the black hole. From the analysis of the lag-energy spectrum, we found a broad, but skewed line with a peak of ≈1000 s at 7.5 keV relative to the continuum, which we interpret as the iron line in the reverberation spectrum from an illuminated accretion disc. From the asymmetry in the shape of lag-energy spectrum, we also found that the source is consistent with having an inclination ≥45°. [ABSTRACT FROM AUTHOR]

Purpose: The major short coming of conventional therapy system is that they can't deliver the therapeutics specifically to a site within the body without producing nonspecific toxicity. Present research aimed at developing kidney targeted allopurinol (AP) loaded chitosan coated magnetic nanoparticles (A-MNPs) for the management of hyperuricemic nephropathy manifested in the form of nephrolithiasis. Methods: The work includes preparation of magnetic nanoparticles by chemical co-precipitation method and evaluation of the prepared batches for particle size analysis, Transmission electron microscopy, entrapment efficiency, in-vitro release study etc. Further, FTIR spectroscopy, X-ray diffraction, Differential Scanning Calorimetry, Vibrational sample magnetometer (VSM) and in-vivo animal studies were also performed. Results: VSM analysis demonstrates that the prepared nanoparticles exhibit superparamagnetic magnetic behaviour which was retained even after coating by chitosan. In-vivo studies of A-MNPs showed 19.07-fold increase in kidney uptake of AP as compared to serum post 2 h of administration in mice whereas no drug was detected in kidney and serum post 2 h administration of pure drug (free-form) indicating successful targeting to kidney as well as sustained release of AP from the formulated A-MNPs. The significant (p < 0.01) effectiveness of A-MNPs in management of hyperuricemic nephrolithiasis was observed through estimating pH and uric acid levels in urine and serum samples of mice. These findings were also confirmed by histological examination of isolated kidney samples. Conclusion: Present investigation signifies that a simple external magnetic field is enough for targeting allopurinol to kidneys by formulating A-MNPs which further offers an effective approach for management of hyperuricemic nephrolithiasis. [ABSTRACT FROM AUTHOR]

• Iatrogenic foreign body in mediastinum found after 14 years. • SEM/EDX analysis to understand the nature of the foreign body. • Responsibility in medical malpractice issues discussed. The retention of gauze within the mediastinum is considered an exceptional finding. We are presenting the case of a woman, affected by aorto-mitral valvulopathy, in whose mediastinum was found, during the autopsy, a gauzome without signs of active phlogosis, which had been "forgotten" in a previous surgery, acted 14 years before the death. A 39 y.o. woman had received surgical treatment of double aorto-mitral valve substitution and tricuspid plastic. At age 53, she successfully received surgery once again at a different hospital; she then started rehabilitation therapy, during which she deceased due to sudden hematemesis with infectious multi organ failure. During the autopsy, a 5 cm long surgical gauze was found in the mediastinum. A SEM/EDX (Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy) exam was ran on the foreign body and a sample of the same gauze used in the cardiac-surgical department of the hospital the victim had passed away in, to act a comparison between the two kinds of material. The exam showed a morphological difference between exogenous fibers incorporated within the gauzome and the control gauze. This case highlights the diagnostic and interpretative challenges in finding a foreign body within the mediastinum without signs of active phlogosis. SEM/EDX investigations executed on the gauzome and a "control gauze" allowed the attribution of malpractice to the first hospital the victim had been operated in 14 years before the exitus. The SEM/EDX exam confirms its importance in correctly identifying the case, which becomes an example for similar happenings. [ABSTRACT FROM AUTHOR]

The bonding and the temperature-driven metalation of 2H-tetraphenylporphyrin (2H-TPP) on the Cu(111) surface under ultrahigh vacuum conditions were investigated by a combination of x-ray photoelectron spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectroscopy with density functional theory calculations. Thin films were prepared by organic molecular beam epitaxy and subsequent annealing. Our systematic study provides an understanding of the changes of the spectroscopic signature during adsorption and metalation. Specifically, we achieved a detailed peak assignment of the 2H-TPP multilayer data of the C1s and the N1s region. After annealing to 420 K both XPS and NEXAFS show the signatures of a metalloporphyrin, which indicates self-metalation at the porphyrin-substrate interface, resulting in Cu-TPP. Furthermore, for 2H-TPP monolayer samples we show how the strong influence of the copper surface is reflected in the spectroscopic signatures. Adsorption results in a strongly deformed macrocycle and a quenching of the first NEXAFS resonance in the nitrogen edge suggesting electron transfer into the LUMO. For Cu-TPP the spectroscopic data indicate a reduced interaction of first-layer molecules with the substrate as demonstrated by the relaxed macrocycle geometry. [ABSTRACT FROM AUTHOR]

The radical oxidation of Ge(100) applying a dielectric barrier discharge plasma was investigated using metastable induced electron spectroscopy, ultraviolet photoelectron spectroscopy, and x-ray photoelectron spectroscopy. The plasma treatments were performed in a pure oxygen atmosphere as well as under environmental conditions at room temperature. In both atmospheres GeO2 layers up to thicknesses of several nm were formed on the Ge(100) surface. [ABSTRACT FROM AUTHOR]

We discuss the processing of data recorded with multimonochromatic x-ray imagers (MMI) in inertial confinement fusion experiments. The MMI records hundreds of gated, spectrally resolved images that can be used to unravel the spatial structure of the implosion core. In particular, we present a new method to determine the centers in all the array of images, a better reconstruction technique of narrowband implosion core images, two algorithms to determine the shape and size of the implosion core volume based on reconstructed broadband images recorded along three-quasiorthogonal lines of sight, and the removal of artifacts from the space-integrated spectra. [ABSTRACT FROM AUTHOR]

In weakly absorbing materials such as polymers and soft tissue, x-ray phase sensitive imaging methods can provide substantially enhanced contrast compared to classical, absorption based radiography. For specific applications, the latter can be applied in a dual energy scheme that helps to identify, discriminate and/or quantify materials. In this paper, we report on a new method that combines the idea of dual energy with x-ray phase contrast imaging and thus provides material sensitivity among poor absorbers. The dual energy modality cannot be applied in common phase contrast imaging schemes because of their demand for limited bandwidth or even monochromatic x-ray sources. Our new interferometric method based on diffraction gratings can overcome this shortcoming and thus simultaneously deliver x-ray phase contrast images for two distinct x-ray energy intervals. It has been shown that high quality images can be obtained with the dual energy phase setup. Energy spectra with 40 kV and 70 kV were applied to obtain low- and high-energy images, respectively. Furthermore, an estimation of the effective energy in the image formation process for absorption and phase contrast was experimentally determined. Examples are shown for which the dual energy phase contrast modality delivers complementary information on material composition when compared with the conventional dual energy scheme. [ABSTRACT FROM AUTHOR]

The local structure of a Zn, Sn codoped In2O3 thin film grown on c⁁-plane sapphire by pulsed-laser deposition was examined by polarization-dependent x-ray absorption spectroscopy. The bixbyite film structure is both out-of-plane and in-plane oriented, and the structural results show that both Zn and Sn dopants occupy In sites. The In–O bond length is comparable to that in powder In2O3. However, both Sn–O and Zn–O bonds have two distinct distances in the first shell. Some of the Zn dopants are undercoordinated and, accordingly, some isovalent Sn dopants are overcoordinated for charge balance. In addition, the results suggest that the aliovalent Sn dopants form Frank–Köstlin clusters, (2SnIn•Oi″)x, which provide enough charge carriers to explain the Hall measurements. [ABSTRACT FROM AUTHOR]

Lithium niobate (LN) crystals, in particular after strong oxidation, are of great relevance for applications in photorefraction and nonlinear optics. Crystals doped with 2 or 4 wt % of iron are studied by extended x-ray absorption fine structure spectroscopy. The Fe atoms are observed to be sixfold coordinated by oxygen atoms and incorporated into the Li site. No evidence for formation of iron oxide clusters is found. In situ x-ray absorption spectroscopy measurements of the thermoelectric oxidation of a LN:Fe 2 wt % crystal and the analyses of the partially site-selective x-ray absorption near edge structure spectra of a LN:Fe 4 wt % crystal provide site-selective structural information. We found that the Fe2+ and Fe3+ sites have the same site symmetries and positions in the LN matrix, i.e., the Fe2+ and Fe3+ atoms are both octahedrally coordinated by six oxygen atoms and both occupy the Li site. [ABSTRACT FROM AUTHOR]

We report the effects of the Mg doping on the dielectric properties of CaCu3Ti4O12 in the frequency range of 200 Hz–200 kHz and in the temperature range of 58–473 K. It is found that the incorporations of Mg2+ result in increases in the dielectric constant by 12%–20% and decreases in the dielectric loss by 41%–64% (with the minimum of 0.042 for CaCu2.7Mg0.3Ti4O12) at room temperature and at 1 kHz. The x-ray photoemission spectroscopy measurements reveal that the content of Cu3+ increases with the increasing concentration of Mg2+. The enhanced dielectric response may be related to the influence of Cu3+ and/or Mg2+. In other words, Mg2+ is an effective ion to optimize the dielectric properties of CaCu3Ti4O12. [ABSTRACT FROM AUTHOR]

X-ray excited optical luminescence (XEOL) and x-ray absorption near-edge structure in total electron, x-ray fluorescence, and photoluminescence yields at Sn M5,4-, O K-, and Sn K-edges have been used to study the luminescence from SnO2 nanoribbons. The effect of the surface on the luminescence from SnO2 nanoribbons was studied by preferential excitation of the ions in the near-surface region and at the normal lattice positions, respectively. No noticeable change of luminescence from SnO2 nanoribbons was observed if the Sn ions in the near-surface region were excited selectively, while the luminescence intensity changes markedly when Sn or O ions at the normal lattice positions were excited across the corresponding edges. Based on the experimental results, we show that the luminescence from SnO2 nanoribbons is dominated by energy transfer from the excitation of the whole SnO2 lattice to the surface states. Surface site specificity is not observable due to its low concentration and weak absorption coefficient although the surface plays an important role in the emission as a luminescence center. The energy transfer and site specificity of the XEOL or the lack of the site specificity from a single-phase sample is discussed. [ABSTRACT FROM AUTHOR]

A method for quantitative measurement of the complex transmissivity of samples is presented where in-line holography and additional shearing interferograms, at a fixed sample-detector distance, are used. The wave field at the detector plane is completely determined and the exit-face wave field of the sample is reconstructed by deconvolution. The principle of experiment and the results of imaging of various samples are described. [ABSTRACT FROM AUTHOR]

We report on a detailed study of structural, magnetic, and electronic properties of MnxGe1-x single crystals (0

The use of combined filtered cathodic vacuum arc (FCVA) technique and laser ablation to fabricate high-quality As doped ZnO (ZnO:As) films at room temperature is proposed. This is possible because FCVA technique is capable of realizing high-quality undoped ZnO films with extremely high resistivity (i.e., extremely low concentration of Zn interstitials) at low deposition temperature. In addition, laser ablation allows the generation of As plume to react with Zn ion species and O2 inside the FCVA chamber to form ZnO:As films. It was shown that high-quality p-type ZnO:As film with a resistivity of 0.05 Ω cm, a mobility of 2 cm2/V s, and a hole concentration of 4×1019 cm-3 was obtained at room temperature by using the proposed deposited technique. X-ray photoemission spectroscopy analysis has indicated that complex of As substitutional Zn induces two Zn vacancies (i.e., AsZn–2VZn complex), which is likely to be the defect contributing to the formation of shallow acceptor lever inside the ZnO:As films. Furthermore, In/Au Ohmic contacts deposited on p-type ZnO:As films and p-n ZnO based homojunction have been fabricated using plastic as the substrate. [ABSTRACT FROM AUTHOR]

Sn1-xMnxO2 nanocrystalline powders were synthesized by a wet chemical method (x<=0.08). X-ray diffraction reveals that single-phase rutile Sn1-xMnxO2 was obtained for x up to about 0.06. Evolution of cell parameters, x-ray photoelectron spectroscopy measurements, thermogravimetric analysis, and quantitative evaluation of the magnetization data all indicate that Mn element acts as Mn4+ for x=0.01 and as Mn3+ for x=0.02 and 0.04 at room temperature, but as Mn3+ for all the samples at 5 K. Magnetization data show that the average magnetic moment per Mn site decreases with increasing x at 5 K, while the effective fraction of the Mn ions contributing to the magnetization decreases. The magnetic properties of the Sn1-xMnxO2 are discussed based on the competition between the free carrier mediated Ruderman-Kittel-Kasuya-Yosida interaction and antiferromagnetic superexchange interaction in the system. [ABSTRACT FROM AUTHOR]

High-pressure Raman and x-ray diffraxtion (XRD) measurements of a defect clathrate Ba8Ge43□3 have been carried out at room temperature up to 40 GPa. Three vibrational modes associated with guest Ba atoms were observed in the low-frequency region, and the structureless spectrum due to Ge vacancies was found in the framework vibrational region. The Raman spectra shows a pressure-induced phase transition at 8 GPa, which is due to the structural distortion through the three-bonded Ge atoms and to the change in the guest-host electronic interaction. Both Raman spectra and XRD patterns present the evidence for the amorphization of Ba8Ge43 around 30–40 GPa. The isostructural phase transition often present in intercalated silicon clathrates and associated with a large volume reduction was not observed for Ba8Ge43 up to 40 GPa. The pressure dependence of the lattice constant (a) normalized by a0 at 1 bar (a/a0) shows the continuous decrease with pressure until amorphization. From the good coincidence of this curve between Ba8Ge43 and Ba8Si46 at pressures above 15 GPa, we propose that the isostructural phase transition found for Ba8Si46 at 15 GPa may be originated from a defect-induced transformation to Ba8Si43□3 with the help of their theoretical equation of state by the first-principles calculations. [ABSTRACT FROM AUTHOR]

The atomic structure of amorphous and crystalline hafnium oxide (HfO2) films was examined using x-ray diffractometry and Hf edge x-ray absorption spectroscopy. According to the x-ray photoelectron spectroscopy and band data calculated by the density functional method, we found that the valence band of HfO2 consists of three subbands separated by ionic gaps. The upper subband is formed by O 2p, Hf 4f, and Hf 5d states; the intermediate subband is formed by O 2s and Hf 4f states, whereas the lower narrow subband is mainly formed by Hf 5p states. The energy gap of amorphous HfO2 is 5.7 eV as determined by electron energy loss spectroscopy. The band calculation results indicate the existence of light (0.3m0) and heavy (8.3m0) holes in the HfO2 film and the effective mass of electron lies in the interval of 0.7m0–2.0m0. [ABSTRACT FROM AUTHOR]

The structural properties and electrical characteristics of thin Nd2O3 gate oxides were deposited on silicon substrates by reactive rf sputtering. The structural and morphological features of these films were studied, as a function of the growth conditions (three various argon-to-oxygen flow ratios: 20/5, 15/10, and 12.5/12.5 and temperature from 600 to 800 °C), by x-ray diffraction, atomic force microscopy, and x-ray photoelectron spectroscopy. It is found that Nd2O3 dielectrics with a 12.5/12.5 ratio condition annealed at 700 °C exhibit a thinner capacitance equivalent thickness and excellent electrical properties, including the electric breakdown field, the interface trap density, the hysteresis, and frequency dispersion in the capacitance-voltage curves. This condition is suggested to the reduction of the interfacial SiO2 and silicate formation, and the small of surface roughness due to the optimization of oxygen in the metal oxide film. [ABSTRACT FROM AUTHOR]

This paper demonstrates a swept high frequency eddy current (SHFEC) methodology that can determine near-surface conductivity deviation profiles of shot-peened superalloy surfaces, from which residual stress state can be assessed nondestructively. Our methodology is built around a laboratory-grade SHFEC hardware and a model-based SHFEC data inversion software, both described in this article. For the demonstration, a series of shot-peened Inconel 718 block specimens is prepared and examined by the proposed SHFEC inversion technique. The conductivity depth profiles of the samples under various shot peening intensities have been obtained by the inversion. Several sensitivity and consistency test results are given to support the reliability of the inverted conductivity profiles. The extreme near-surface regions (10–20 μm) of the shot-peened surfaces are also examined by various microstructural characterization methods such as scanning electron microscopy, energy dispersive x-ray spectroscopy, and x-ray diffraction, to examine our inversion results microscopically. [ABSTRACT FROM AUTHOR]