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Cu–Ti alloys are candidates for replacing Cu–Be alloys owing to their excellent mechanical properties, bending properties, and stress relaxation resistance. However, the precipitation behavior of Cu–Ti alloys remains poorly understood. In this study, diffraction patterns, orientations, and morphologies of continuous and discontinuous precipitates in a Cu–3 wt% Ti (Cu–3Ti) alloy are investigated by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). In the peak-aging condition, numerous rod-like nanosized continuous precipitates (CP) of β′-Cu4Ti are uniformly distributed in the Cu–3Ti alloy. The CP retain their tetragonal structure, and their orientation relationships with the matrix are determined as [001]Cu//[001]β' and (010)Cu//(310)β', exhibiting six variants. With increasing aging time, discontinuous precipitates (DP) of β-Cu4Ti grow at the grain boundaries, displaying an orthorhombic structure (a = 0.453 nm, b = 0.4342 nm, and c = 1.293 nm). The orientation relationships between the DP and the Cu-matrix are determined as (Laughlin and Cahn, 1975; Han et al., 2016; Datta and Soffa, 1976; Han et al., 2020; Huang et al., 2023; Soffa and Laughlin, 2004; Wang et al., 2021; Si et al., 2016; Markandeya et al., 2004; Nagarjuna et al., 2001) [1-10]Cu//[501]β and (111)Cu//(010)β. Typical diffraction pattern models of the CP and DP in different directions were simulated, and the simulations were in good agreement with the experimental data.

This research work has developed a classic method to synthesize high crystalline ~50nm copper (Cu) nanoparticles at a low temperature of 80oC. While nanoparticle synthesis is a concern, a rapid chemical reduction method (CRM) was introduced by reducing copper salts and an appropriate capping agent. The capping agent facilities controlled the movement and formation of nanoparticles that were further investigated by X-ray Diffraction (XRD), Thermo-gravimetric Analysis (TGA), Transmission Electron Microscope (TEM), and Selected Area Electron Diffraction (SAED) as well as TEM couple EDS. The such in-depth analysis demonstrates a 100% crystalline phase with having to predominate (111), (200), and (220) planes and 84% purity. The medium and process protocol selection may be adapted to synthesize other nanoparticles for different functional applications.

Electron diffraction patterns obtained on a TEM contain elliptical distortion resulting from column defects. This distortion can be corrected by applying offsets to the objective lens stigmators to cancel distortions occurring further down the column. In this work, a DigitalMicrographTM script‐based method has been developed to identify the optimum objective stigmator settings which produce a distortion minimum in diffraction. Initially, a manual (by eye) correction is used to determine the stigmator values necessary to bring the pattern distortion below the threshold at which it is no longer visible to the naked eye (<1%). Thereafter, an automated acquisition script is used to acquire matrices of diffraction patterns while varying the stigmator values about the values which were identified as producing a distortion minimum in the preceding step. This analysis can be applied iteratively to refine the location of the distortion minimum, using progressively finer step changes in objective stigmator values. The optimum stigmator values producing the distortion minimum in diffraction are very different to those in imaging. These imaging and diffraction stigmator values can be saved to script and subsequently recalled at the click of a button, making their application very simple. Using this method, diffraction pattern elliptical distortion in a newly installed TEM was reduced from 1.6% to 0.3%, on a measurement precision of 0.3%, effectively producing distortion‐free diffraction. The relevant scripts can be freely downloaded from the internet. Research Highlights: This paper reports a DigitalMicrograph script‐based method to identify and subsequently apply optimized objective stigmator values in diffraction mode. These effectively eliminate elliptical distortion inherent to this diffraction technique. [ABSTRACT FROM AUTHOR]

This research work describes the impact of the surface mechanical attrition treatment (SMAT) on the microstructure of cobalt–chromium–molybdenum (CoCrMo), a biomedical alloy commonly used for orthopedic applications. This surface treatment induces crystalline phases transformations characterized by X‐ray diffraction (XRD) and selected area electron diffraction (SAED). The corresponding structural changes are observed from cross‐section images obtained by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the SMAT process induces the martensitic transformation of the CoCrMo alloy (from γ‐fcc phase to ε‐hcp phase) related to an important grain refinement due to twinning and sliding. [ABSTRACT FROM AUTHOR]

In the study of precipitates in high-Nb non-oriented silicon steel for the rotor of electric automobiles, it was found that mass dispersed Nb-rich precipitates were formed during the rolling process of the steel, these precipitates are presumed to be Laves phases in published literatures. In this regard, two types of Laves phases of high-Nb non-oriented silicon steel for electric automobiles and their crystallographic relationship with the Fe matrix were determined using SAED, FFT and IFFT, and calculation of steel strength enhancement by precipitation strengthening. The results showed the elliptical Laves phase is Fe _16 Nb _6 Si _7 and the rectangular strip Laves phase is Nb _7 P _4 , and the orientation relationship between Fe _16 Nb _6 Si _7 phase and Fe matrix is : [001] _Fe16Nb6Si7 ∥[001] _Fe , [101] _Fe16Nb6Si7 ∥[110] _Fe , [113] _Fe16Nb6Si7 ∥[112] _Fe , the orientation relationship between Nb _7 P _4 phase and Fe matrix is : [130] _Nb7P4 ∥[001] _Fe , [102] _Nb7P4 ∥[110] _Fe , [110] _Nb7P4 ∥[112] _Fe ; Both Fe _16 Nb _6 Si _7 and Nb _7 P _4 precipitates have a good coherent relationship with the Fe matrix; The calculation results show that Fe _16 Nb _6 Si _7 , Nb _7 P _4 and other precipitates can improve the yield strength of non-oriented silicon steel, but at the same time, the magnetic properties of the steel are expected to be negatively impacted. The research results can provide important theoretical guidance on the influence of thermo-mechanical processing on balancing the mechanical and magnetic properties of high niobium non-oriented silicon steel for electric vehicle rotor.

Electron diffraction is an essential characterization tool for materials scientists. When using the transmission electron microscope (TEM) to perform diffraction experiments, setting up the microscope for both calibration standards and unknown materials in a consistent method ensures that dependable results are obtained. Care must also be exercised to protect digital cameras from intense transmitted and diffracted beams to avoid damage. In Parts 1 and 2 of this series, procedures were presented for recording high-quality, well-calibrated, digital SAED patterns. In Part 3, aspects of diffraction analysis software packages and the reliability of data are discussed. [ABSTRACT FROM AUTHOR]

Electron diffraction is an essential tool for materials scientists to have in their characterization toolboxes. When using the transmission electron microscope (TEM) to perform diffraction experiments, setting up the microscope for both calibration standards and unknown materials in a consistent method will ensure that dependable results are obtained. Care must also be exercised to protect digital cameras from intense transmitted and diffracted beams to avoid damage. In Part 2 of this series a procedure is presented for the proper recording of SAED patterns. [ABSTRACT FROM AUTHOR]

Bio‐fabrication of gold nanoparticles (AuNPs) has several advantages like biocompatibility, less toxicity, and eco‐friendly in nature over their chemical and physical methods. Currently, the authors fabricated AuNPs using aqueous root extract of Momordica dioica (M. dioica) and explored their anticancer application with mechanistic approaches. Different biophysical techniques such as UV–visible spectroscopy, Fourier transform infrared, X‐ray diffraction, transmission electron microscopy, selected area electron diffraction, and dynamic light scattering were employed for AuNPs characterisation. The synthesised AuNPs were mono‐dispersed, crystalline in nature, anionic surface (−23.9 mV), and spherical particle of an average diameter of 9.4 nm. In addition, the AuNPs were stable in buffers solutions and also biocompatible towards normal human cells (human vascular endothelial cells and human lung cells). The AuNPs were exhibited anticancer activity against different cancer cell lines such as human breast cancer cells, human cervical cancer cells (HeLa) and human lung cancer cells. Further, the pro‐apoptotic genes such as Bcl2 were down‐regulated and BAX, Caspase‐3, −8, and −9 were up‐regulated in HeLa cells as compared to untreated cells. Annexin‐V‐FITC assay results showed that the AuNPs were induced apoptosis by accumulation of intracellular reactive oxygen species. To their knowledge, this is the first report on the synthesis of bioactive metal nanoparticles from M. dioica and it may open up new avenues in therapeutic applications. [ABSTRACT FROM AUTHOR]

Electron diffraction is an essential tool for materials scientists to have in their characterization toolboxes. When using the transmission electron microscope (TEM) to perform diffraction experiments, setting up the microscope for both calibration standards and unknown materials in a consistent method will ensure that dependable results are obtained. Care must also be exercised to protect digital cameras from intense transmitted and diffracted beams to avoid damage. A procedure is presented that will allow a microscopist to reproducibly configure the microscope and sample to acquire selected area electron diffraction patterns so that these issues are addressed. [ABSTRACT FROM AUTHOR]

The quantity of the crystalline phases present in a nanomaterial is an important parameter that governs the correlation between its properties and microstructure. However, quantification of crystallinity in nanoscale‐level applications by conventional methods (Raman spectroscopy and X‐ray diffraction) is difficult because of the spatial limitations of sampling. Therefore, we propose a technique that involves using energy‐filtered electron diffraction in transmission electron microscopy which offers improved spatial resolution. The degree of crystallinity (DOC) was calculated by separating the crystalline and amorphous intensities from the total intensity histogram acquired by the azimuthal averaging of the zero‐loss filtered signals from electron diffraction. In order to validate the method, it was demonstrated that the DOC calculated by zero‐loss filtered electron diffraction was consistent with the DOC measured by the area ratio using an amorphous silicon on crystalline silicon standard sample. In addition, the results obtained from zero‐loss filtered and conventional electron diffractions were compared. The zero‐loss filtered electron diffraction successfully provided the reliable results of the crystallinity quantification. In contrast, the DOC measured using conventional electron diffraction yielded extremely variable results. Therefore, our results provide a crystallinity quantification technique that can extract quantitative information about crystallinity of nanoscale devices by using zero‐loss filtered electron diffraction with better reliability than conventional electron diffraction. Research highlights: The degree of crystallinity can be measured by separating the crystalline and amorphous intensities from the total intensity histogram acquired by the azimuthal averaging of the zero‐loss filtered signals from selected area electron diffraction. The degree of crystallinity can be measured by separating the crystalline and amorphous intensities from the total intensity histogram acquired by the azimuthal averaging of the zero‐loss filtered signals from selected area electron diffraction. [ABSTRACT FROM AUTHOR]

The bio‐synthesis of palladium nanocubes (PdNCs) was realised using pine needle extract as the reducing agent and cetyl trimethyl ammonium bromide as the capping agent. As an eco‐friendly and readily available biomass, pine needle extract avoided the use of highly polluting chemical reducing agents. The growth process of PdNCs was analysed using ultraviolet–vis and Fourier transform infrared spectroscopy. Flavonoids, esters, terpenoids and polyhydric alcohols, which contain reductive groups, were mainly responsible for the transition of Pd2+ ions to PdNCs. The morphology and structure of PdNCs were characterised using transmission electron microscopy (TEM), high‐resolution TEM, selected area electron diffraction and X‐ray diffraction. It was indicated that the as‐prepared PdNCs displayed a relatively high purity and good crystallinity with a face‐centred cubic structure and exhibited sizes ranging from 6.11 to 29.51 nm with an average particle size of 11.18 nm. In the methanol electro‐oxidation reaction, the PdNCs enclosed by {100} facets exhibited superior electro‐catalytic activity to commercial Pd/C, which was rarely reported in other bio‐synthesis processes for Pd catalysts. Meanwhile, the PdNCs showed excellent anti‐poisoning ability and long‐term stability. This study reveals the possibility of preparing shape‐controlled PdNCs with a specific structure and excellent electro‐catalytic activity. [ABSTRACT FROM AUTHOR]

CaO nanoparticles have been prepared using CaCl2 and aqueous extract of broccoli as a precursor and reducing agent, respectively. Different volumes of the aqueous broccoli extract were utilised to obtain Ca(OH)2 and subsequent calcination gave CaO nanoparticles. The synthesised CaO was confirmed by powder X‐ray diffraction (XRD). The morphology was studied using transmittance electron microscopy (TEM), and the surface composition of Ca(OH)2 was explored using Fourier transform infrared spectroscopy. The major functional groups present in the capping material responsible for the reduction of the metal salt and the surface passivation of Ca(OH)2 were identified. The XRD pattern revealed cubic phase for all the CaO nanoparticles, and the crystallite size was estimated using Scherrer's equation showed a variation which is dependent on the volume of the extract used. TEM analysis showed different shapes, while the selected area electron diffraction (SAED) results confirmed the crystallinity of the nanoparticles. Thermogravimetric analysis of Ca(OH)2 showed the decomposition product to be CaO. Sample C3, which has the smallest particle size, was used as a catalyst for the degradation of bromocresol green via photo irradiation with ultraviolet light and the result revealed a degradation efficiency of 60.1%. [ABSTRACT FROM AUTHOR]

Poly(butylene succinate- co -butylene fumarate) (PBSF) copolymers with butylene fumarate (BF) molar ratio varies from 1% to 40% were synthesized and their single crystals were prepared using a self-seeding method. For PBSFs with low content of BF units, the single crystals are regular hexagonal shape. With the increase of BF molar ratio, the single crystal boundary turns rounded and the aspect ratio decreases. PBSF single crystals with different BF content were prepared at the same temperature, the supercooling degree of the PBSF increases with the increase of BF content, resulting the crystalline density increases and the single crystal size decreases. Selected area electron diffraction (SAED) was used to investigate the crystalline structures of the PBSF single crystals, and the results approve strict isomorphism between butylene succinate (BS) and BF in PBSF, verifying that preparing the single crystal and characterizing the crystalline structure by SAED is a direct method to check for isomorphic polymers. PBSFs can form ring-band spherulites at suitable crystallization temperatures. The band spacing of PBSF increases with the increase of isothermal crystallization temperature. At the same isothermal crystallization temperature, the band spacing PBSF decreases with the increase of BF molar ratios. The crystallization temperature range of forming ring-banded spherulites broadens with the increase of BF molar ratios. [ABSTRACT FROM AUTHOR]

The microstructure of a Ti-8Mo-6Fe ternary alloy with ultrafine grains was systematically studied with Tecnai-G2 F20 field transmission electron microscope and JEMS 2010 transmission electron microscope. A new Ti phase with face-centered-cubic (Fm-3m) structure was discovered. The morphology of these FCC Ti phases was elliptical, and they were widely distributed at interfaces between the polygonal BCC TiMoFe phases. The size of the FCC Ti phases was concentrated in the range of 200–450 nm. The lattice constant of FCC Ti phase was 0.431 nm. Simulated high-resolution images of FCC Ti and compounds of FCC TiC, TiN and TiO with different thicknesses and different defocus amounts were carried out to prove that the FCC structure in Ti-8Mo-6Fe alloy was indeed FCC Ti but not FCC TiC, TiN and TiO. First principle calculations revealed the metallic properties and stability of FCC Ti. All alloy elements of Mo and Fe were in the polygonal BCC TiMoFe phases. The semicircular arc periodic strips formed by electron diffuse scattering were present on the selected area electron diffraction (SAED) patterns of the BCC TiMoFe phase, which may come from the ordered domain of Mo and Fe or local ordering by Mo, Fe and Ti. [ABSTRACT FROM AUTHOR]

Comparative chemical and structural characterization of various apatite phases from both synthetic and natural sources were carried out by utilizing a multi-sample loading device developed for scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The device is capable of spraying nanoparticles via ultrasonication, and four separate samples were loaded on a single TEM grid by a masking tool to characterize different apatite phases in consistent instrumental and analytical conditions. SEM energy dispersive spectroscopy (EDS) analysis of the apatite samples revealed distinctive values of O/P and Ca/P intensity ratios except for the fossil apatite due to its high proportion of externally originating phases. Selected area electron diffraction (SAED) pattern analysis presented the characteristic lattice parameters of the apatite phases, especially the bone and fossil apatite which had CO 3 in their chemistry. Analyzing distinctive chemical and structural features among varied apatite phases can be efficiently carried out through electron microscopy with multiple samples on a single TEM grid, and such methods can be employed for characterizing a wider range of materials. [ABSTRACT FROM AUTHOR]

This paper presents a study of structural properties of InGaAs/InAlAs quantum well (QW) heterostructures with convex-graded In x Al 1-x As ( x = 0.05–0.79) metamorphic buffer layers (MBLs) grown by molecular beam epitaxy on GaAs substrates. Mechanisms of elastic strain relaxation in the convex-graded MBLs were studied by the X-ray reciprocal space mapping combined with the data of spatially-resolved selected area electron diffraction implemented in a transmission electron microscope. The strain relaxation degree was approximated for the structures with different values of an In step-back. Strong contribution of the strain relaxation via lattice tilt in addition to the formation of the misfit dislocations has been observed for the convex-graded InAlAs MBL, which results in a reduced threading dislocation density in the QW region as compared to a linear-graded MBL. [ABSTRACT FROM AUTHOR]

The aqueous extract of Chinese winter jujube (Ziziphus jujuba Mill. cv. Dongzao) was used as reducing and capping agents for the synthesis of silver nanoparticles (AgNPs) for the first time. The resulting AgNPs were characterised by UV/Visible (UV–Vis) spectroscopy, atomic force microscope, transmission electron microscopy, selected area electron diffraction, X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray and Fourier transform infrared spectroscopy (FTIR). The colloidal solution of AgNPs gave a maximum UV–Vis absorbance at 446 nm. The synthesised nanoparticles were almost in the spherical shapes with an average size of 11.5 ± 4. 8 nm. FTIR spectra were applied to identify the functional groups which were possibly responsible for the conversion of metal ions into nanoparticles. The results showed that the prepared AgNPs were coated with the biomolecules in the extract. The biosynthesised AgNPs showed a remarkable catalytic activity at room temperature, and they also showed good antibacterial properties against Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

In the recent decades, nanotechnology is gaining tremendous impetus due to its capability of modulating metals into their nanosize, which drastically changes the chemical, physical, biological and optical properties of metals. In this study, silver nanoparticles (AgNPs) synthesis using aqueous leaf extracts of Tagetes patula L. which act as reducing agent as well as capping agent is reported. Synthesis of AgNPs was observed at different parameters like temperature, concentration of silver nitrate, leaf extract concentration and time of reduction. The AgNPs were characterized using UV‐vis spectroscopy, scanning electron microscope with energy dispersive spectroscopy, transmission electron microscopy with selected area electron diffraction, X‐ray diffraction, Fourier transform infrared and dynamic light scattering analysis. These analyses revealed the size of nanoparticles ranging from 15 to 30 nm as well revealed their spherical shape and cubic and hexagonal lattice structure. The lower zeta potential (−14.2mV) and the FTIR spectra indicate that the synthesized AgNPs are remarkably stable for a long period due to the capped biomolecules on the surface of nanoparticles. Furthermore, these AgNPs were found to be highly toxic against phytopathogenic fungi Colletotrichum chlorophyti by both in vitro and in vivo and might be a safer alternative to chemical fungicides. [ABSTRACT FROM AUTHOR]

Biological synthesis of nanomaterials is a growing innovative approach and it was broadly utilised in the field of nanotechnology and nanomedicine. This study illustrates that biosynthesis of silver nanoparticles (AgNPs) using fucoidan extracted from seaweed Padina tetrastromatica. The functional groups of extracted fucoidan were characterised by Fourier transform infrared spectroscopy (FTIR) and used to NPs synthesis. Synthesised AgNPs were characterised by ultraviolet–visible spectra, scanning electron microscope, energy dispersive X‐ray, transmission electron microscope, selected area electron diffraction and FTIR. In this study, their main focus is enhancement antibacterial activity of AgNPs coated antibiotics against antibiotic resistant bacteria. Among the microorganisms, Serratia nematodiphila was resistant to novobiocin and penicillin, but it was sensitive to AgNPs impregnated antibiotic discs. The zone of inhibition was 12 and 15 mm. The synergistic effect of combined antibiotics and AgNPs resulted in increased fold area which was greater than the sum of their separate effects. It reveals that AgNPs are highly sought in the medicinal field due to their broad spectrum of antibacterial activity and relatively cheaper. This enhanced synergistic effect potentially superior to control the growth of bacteria and it is the budding process for the development of new remedial agents for severe diseases. [ABSTRACT FROM AUTHOR]

A biosynthetic method for the production of selenium nanoparticles under ambient temperature and pressure from sodium selenite was developed using Gram‐negative bacterial strain Escherichia coli ATCC 35218. Bacteriogenic nanoparticles were methodologically characterized employing UV‐vis, XRD, Raman spectroscopy, SEM, TEM, DLS and FTIR techniques. Generation of nanoparticles was visualized from the appearance of red colour in the selenite supplemented culture medium and broad absorption bands in the UV‐vis. Biofabricated nanoparticles were spherical, polydisperse, ranged from 100‐183 nm and the average particle size was about 155 nm. Based on selected‐area electron diffraction, XRD patterns; and Raman spectroscopy the nanospheres were found to be amorphous. IR spectrum revealed the involvement of bacterial proteins in the reduction of selenite and stabilization of nanoparticles. Used bacterial strain demonstrated efficient selenite reduction capability which was evident from 89.2% of selenium removal within 72 h at a concentration of 1 mM. Observation noted in the current study highlight the importance of bacterial reduction in selenium nanoparticle generation which can be scaled up for commercial production. Also, the bacteriogenic, amorphous nanoparticles can also be used as nutritional supplements for humans since selenium nanoparticles of 5‐200 nm are bioavailable and known to induce seleno enzymes involved in antioxidant defence. [ABSTRACT FROM AUTHOR]

Purpose: To find an efficient method to configure the proton fluence for a commercial proton pencil beam scanning (PBS) treatment planning system (TPS). Methods: An in-water dose kernel was developed to mimic the dose kernel of the pencil beam convolution superposition algorithm, which is part of the commercial proton beam therapy planning software, ECLIPSE™ (Varian Medical Systems, Palo Alto, CA). The field size factor (FSF) was calculated based on the spot profile reconstructed by the in-house dose kernel. The workflow of using FSFs to find the desirable proton fluence is presented. The in-house derived spot profile and FSF were validated by a direct comparison with those calculated by the ECLIPSE TPS. The validation included 420 comparisons of the FSFs from 14 proton energies, various field sizes from 2 to 20 cm and various depths from 20% to 80% of proton range. Results: The relative in-water lateral profiles between the in-house calculation and the ECLIPSE TPS agree very well even at the level of 10-4. The FSFs between the in-house calculation and the ECLIPSE TPS also agree well. The maximum deviation is within 0.5%, and the standard deviation is less than 0.1%. Conclusions: The authors' method significantly reduced the time to find the desirable proton fluences of the clinical energies. The method is extensively validated and can be applied to any proton centers using PBS and the ECLIPSE TPS. [ABSTRACT FROM AUTHOR]

Purpose: CyberKnife system is initially equipped with fixed circular cones for stereotactic radiosurgery. Two dose calculation algorithms, Ray-Tracing and Monte Carlo, are available in the supplied treatment planning system. A multileaf collimator system was recently introduced in the latest generation of system, capable of arbitrarily shaped treatment field. The purpose of this study is to develop a model based dose calculation algorithm to better handle the lateral scatter in an irregularly shaped small field for the CyberKnife system. Methods: A pencil beam dose calculation algorithm widely used in linac based treatment planning system was modified. The kernel parameters and intensity profile were systematically determined by fitting to the commissioning data. The model was tuned using only a subset of measured data (4 out of 12 cones) and applied to all fixed circular cones for evaluation. The root mean square (RMS) of the difference between the measured and calculated tissue-phantom-ratios (TPRs) and off-center-ratio (OCR) was compared. Three cone size correction techniques were developed to better fit the OCRs at the penumbra region, which are further evaluated by the output factors (OFs). The pencil beam model was further validated against measurement data on the variable dodecagon-shaped Iris collimators and a half-beam blocked field. Comparison with Ray-Tracing and Monte Carlo methods was also performed on a lung SBRT case. Results: The RMS between the measured and calculated TPRs is 0.7% averaged for all cones, with the descending region at 0.5%. The RMSs of OCR at infield and outfield regions are both at 0.5%. The distance to agreement (DTA) at the OCR penumbra region is 0.2 mm. All three cone size correction models achieve the same improvement in OCR agreement, with the effective source shift model (SSM) preferred, due to their ability to predict more accurately the OF variations with the source to axis distance (SAD). In noncircular field validation, the pencil beam calculated results agreed well with the film measurement of both Iris collimators and the half-beam blocked field, fared much better than the Ray-Tracing calculation. Conclusions: The authors have developed a pencil beam dose calculation model for the CyberKnife system. The dose calculation accuracy is better than the standard linac based system because the model parameters were specifically tuned to the CyberKnife system and geometry correction factors. The model handles better the lateral scatter and has the potential to be used for the irregularly shaped fields. Comprehensive validations on MLC equipped system are necessary for its clinical implementation. It is reasonably fast enough to be used during plan optimization. [ABSTRACT FROM AUTHOR]

Purpose: The "InCise™multileaf-collimator (MLC)" is the first commercial MLC to be mounted on a robotic SRS/SBRT platform (CyberKnife). The authors assessed characteristics and performance of this novel device in a preclinical five months test period. Methods: Commissioning beam data were acquired with unshielded diodes. EBT3 radiochromic films were employed for measurement of transmission, leaf/bank position accuracy (garden fence) before and after exercising the MLC, for end-to-end testing and further characterization of the beam. The robot workspace with MLC was assessed analytically by transformation to an Euler geometry ("plane," "gantry," and "collimator" angles) and by measuring pointing accuracy at each node. Stability over time was evaluated in picket fence and adapted Winston-Lutz tests (AQA). Results: Beam penumbrae (80%-20%, with 100% = 2×dose at inflection point for field sizes ≥ 50 ×50 mm2) were 2.2-3.7 mm for square fields in reference condition (source-axis-distance 800 mm, depth 15 mm) and depended on field size and off-axis position. Transmission and leakage did not exceed 0.5%. Accessible clinical workspace with MLC covered non-coplanar gantry angles of [-113°; +112°] and collimator angles of [-100°; +107°], with an average robot pointing accuracy of 0.12±0.09 mm. For vertical beams, garden fence tests exhibited an average leaf positioning error of ≤0.2 mm, which increased by 0.25 and 0.30 mm (banks X1 and X2) with leaves traveling parallel to gravity. After execution of a leaf motion stress routine, garden fence tests showed slightly increased jaggedness and allowed to identify one malfunctioning leaf motor. Total system accuracy with MLC was 0.38±0.05 mm in nine end-to-end tests. Picket fence and AQA tests displayed stable results over the test period. Conclusions: The InCise™ MLC for CyberKnife showed high accuracy and adequate characteristics for SRS/SBRT applications. MLC performance after exercise demands specific quality assurance measures. [ABSTRACT FROM AUTHOR]

γ-MoO3 nanobelts prepared by hydrothermal synthesis were studied by synchrotron radiation powder diffraction, scanning electron microscopy, transmission electron microscopy and selected area electron diffraction. Their nm dimensions, in particular in two crystallographic directions, have a profound influence on electrochemical properties during cycling as the cathode material in lithium-ion batteries (LIBs). The diffraction analysis shows clearly that the crystal structure for the γ-MoO3 nanobelts differs significantly from that of bulk α-MoO3. The observed powder diffraction pattern, with asymmetric peaks, extremely broad peaks, as well as additional or absent diffraction peaks, is fully described by means of a model based on stacking disorder of MoO3 slabs. [ABSTRACT FROM AUTHOR]

Purpose: Information about tendon displacement is important for allowing clinicians to not only quantify preoperative tendon injuries but also to identify any adhesive scaring between tendon and adjacent tissue. The Fisher-Tippett (FT) similarity measure has recently been shown to be more accurate than the Laplacian sum of absolute differences (SAD) and Gaussian sum of squared differences (SSD) similarity measures for tracking tendon displacement in ultrasound B-mode images. However, all of these similarity measures can easily be influenced by the quality of the ultrasound image, particularly its signal-to-noise ratio. Ultrasound images of injured hands are unfortunately often of poor quality due to the presence of adhesive scars. The present study investigated a novel Kalman-filter scheme for overcoming this problem. Purpose: Information about tendon displacement is important for allowing clinicians to not only quantify preoperative tendon injuries but also to identify any adhesive scaring between tendon and adjacent tissue. The Fisher-Tippett (FT) similarity measure has recently been shown to be more accurate than the Laplacian sum of absolute differences (SAD) and Gaussian sum of squared differences (SSD) similarity measures for tracking tendon displacement in ultrasound B-mode images. However, all of these similarity measures can easily be influenced by the quality of the ultrasound image, particularly its signal-to-noise ratio. Ultrasound images of injured hands are unfortunately often of poor quality due to the presence of adhesive scars. The present study investigated a novel Kalman-filter scheme for overcoming this problem. Results: The experimental results indicated that SSD exhibited better accuracy in the phantom experiments, whereas FT exhibited better performance for tracking real tendon motion in the cadaver experiments. All three tracking methods were influenced by the signal-to-noise ratio of the images. On the other hand, the K1 scheme was able to optimize the tracking trajectory of displacement in all experiments, even from a location with a poor image quality. The human experimental data indicated that the normal tendons were displaced more than the injured tendons, and that the motion ability of the injured tendon was restored after appropriate rehabilitation sessions. Conclusions: The obtained results show the potential for applying the proposed FT-K1 method in clinical applications for evaluating the tendon injury level after metacarpal fractures and assessing the recovery of an injured tendon during rehabilitation. [ABSTRACT FROM AUTHOR]

In this study, Al–Cr–Fe powders were consolidated using spark plasma sintering at different temperatures (650 °C, 700 °C, 750 °C and 800 °C). The sintered samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The porosity of the pellets is very sensitive to the sintering temperature: it reduces sharply from around 29.3% to around 3.1% when the sintering temperature increases from 650 °C to 700 °C probably due to the softening of quasicrystals at elevated temperatures. Metastable icosahedral Al–Cr–Fe transforms to stable decagonal Al–Cr–Fe in sintering process. Stable icosahedral Al–Cr–Fe forms in the samples sintered at 700 °C, 750 °C and 800 °C. Both stable quasicrystalline phases form through the nucleation and growth process in the sintering process. Selected area electron diffraction (SAED) analysis shows that the icosahedral phase and the decagonal phase formed in the sintering process have a quasilattice constant of about 0.45 nm and 1.2 nm, respectively. [ABSTRACT FROM AUTHOR]

Background: The objective of this investigation was to design and optimize the fabrication of Rasagiline mesylate loaded nanoscale solid lipid particles composed with stearic acid as lipid matrix by microemulsion technique. Rasagiline (N-propargyl- 1-R-aminoindan) mesylate (RM) is a potent, selective, irreversible inhibitors of monoamine oxidase-B, propargylaminebased drug. It has been explored in the treatment of Parkinson disease. Nanoscale solid lipid particles are the exploited carrier system for targeted drug delivery in a controlled manner. Method: The Plackett-Burman design was successfully employed for the optimization of nanoscale solid lipid particles containing Rasagiline mesylate. The influence of independent variables studied were lipid, surfactant and co-surfactant concentration, volume of aqueous phase, magnetic stirring rate, probe sonicator duration, volume of beaker used and volume of cold aqueous phase. The dependent variables, namely average particle size, span, surface area and polydispersity index of the formulated Rasagiline mesylate loaded solid lipid nanoparticles. Results: The experiments were carried out according to 12 runs involving 8 independent variables (higher and lower levels) employing Plackett-Burman design. The Rasagiline mesylate-loaded solid lipid nanoparticles were characterized by average mean particle size, span, surface area and polydispersity index and it results were 169 nm, 0.821, 52.4 m2g-1 and 0.310, respectively. The morphological evaluation of optimal Rasagiline mesylate loaded solid lipid nanoparticles was found to be monodisperse, uniform size and quasispherical shape with smooth surface by transmission electron microscopy (TEM). The selected area electron diffraction (SAED) indicated the formulation was not in an amorphous form but in a crystalline state. Conclusion: The experimental results were good correlated with predicted data analysed by Plackett-Burman statistical method. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this work was to develop a treatment planning workflow for rapid radiotherapy delivered with very high-energy electron (VHEE) scanning pencil beams of 60-120 MeV and to study VHEE plans as a function of VHEE treatment parameters. Additionally, VHEE plans were compared to clinical state-of-the-art volumetric modulated arc therapy (VMAT) photon plans for three cases. Methods: VHEE radiotherapy treatment planning was performed by linking EGSnrc Monte Carlo (MC) dose calculations with inverse treatment planning in a research version of RayStation. In order to study the effect of VHEE treatment parameters on VHEE dose distributions, a MATLAB graphical user interface (GUI) for calculation of VHEE MC pencil beam doses was developed. Through the GUI, pediatric case MC simulations were run for a number of beam energies (60, 80, 100, and 120 MeV), number of beams (13, 17, and 36), pencil beam spot (0.1, 1.0, and 3.0 mm) and grid (2.0, 2.5, and 3.5 mm) sizes, and source-to-axis distance, SAD (40 and 50 cm). VHEE plans for the pediatric case calculated with the different treatment parameters were optimized and compared. Furthermore, 100 MeV VHEE plans for the pediatric case, a lung, and a prostate case were calculated and compared to the clinically delivered VMAT plans. All plans were normalized such that the 100% isodose line covered 95% of the target volume. Results:VHEE beam energy had the largest effect on the quality of dose distributions of the pediatric case. For the same target dose, the mean doses to organs at risk (OARs) decreased by 5%-16% when planned with 100 MeV compared to 60 MeV, but there was no further improvement in the 120 MeV plan. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams, but to a more modest degree (<8%). While pencil beam spacing and SAD had a small effect on VHEE dose distributions, 0.1-3 mm pencil beam sizes resulted in identical dose distributions. For the 100 MeV VHEE pediatric plan, OAR doses were up to 70% lower and the integral dose was 33% lower for VHEE compared to 6 MV VMAT. Additionally, VHEE conformity indices (CI100 = 1.09 and CI50 = 4.07) were better than VMAT conformity indices (CI100 = 1.30 and CI50 = 6.81). The 100 MeV VHEE lung plan resulted in mean dose decrease to all OARs by up to 27% for the same target coverage compared to the clinical 6 MV flattening filter-free (FFF) VMAT plan. The 100 MeV prostate plan resulted in 3% mean dose increase to the penile bulb and the urethra, but all other OAR mean doses were lower compared to the 15 MV VMAT plan. The lung case CI100 and CI50 conformity indices were 3% and 8% lower, respectively, in the VHEE plan compared to the VMAT plan. The prostate case CI100 and CI50 conformity indices were 1% higher and 8% lower, respectively, in the VHEE plan compared to the VMAT plan. Conclusions: The authors have developed a treatment planning workflow for MC dose calculation of pencil beams and optimization for treatment planning of VHEE radiotherapy. The authors have demonstrated that VHEE plans resulted in similar or superior dose distributions for pediatric, lung, and prostate cases compared to clinical VMAT plans. [ABSTRACT FROM AUTHOR]

Background: Nanoscale solid lipid particles of rasagiline mesylate (RM) were fabricated by microemulsion technique. The nanoscale particle must be sterile for intravenous administration, and several approaches are available for sterilization. However, the selection of sterilization technique for the fabricated RM loaded nanoscale solid lipid particles mainly depends on the nature of the drug that needs to be encapsulated and release pattern of the polymer. Materials and Methods: We have preferred moist heat sterilization, as it is the most convenient and the composition of the carrier and incorporated drug should remain unchanged and the incorporated drug should not leak out of the drug carrier. The physical and chemical stability of RM loaded nanoscale solid lipid particles investigated during sterilization and to determine the average mean particle size, polydispersity index, zeta potential (ZP), transmission electron microscopy (TEM), entrapment efficiency (EE), and drug content after autoclaving. Result: There were no significant changes in the average mean particle size, polydispersity index, ZP, TEM, EE, and drug content of RM loaded nanoscale solid lipid particles after autoclaving (121°C for 20 min [15 lbs]). Conclusion: These observations suggest that the moist heat sterilization by autoclaving is the most suitable method for nanoscale solid lipid formulations. [ABSTRACT FROM AUTHOR]

Iron doped Yttrium Copper Titanate nano-ceramic with composition, Y 2/3 Cu 3 Ti 3.90 Fe 0.10 O 12 (YCTFO) was prepared by semi-wet route. It displays all normal XRD peaks of Y 2/3 Cu 3 Ti 4 O 12 (YCTO) along with a few secondary peaks of CuO. Stoichiometric purity of the composition was ascertained by EDX spectral analysis. The distribution of bimodal spherical grains confirms 0.5–1.5 µm size limit along with a few irregular shaped large grains with size 1.5–2.8 µm. The impacts of acceptor type of hetero-valent substitution of Ti 4+ by Fe 3+ in Y 2/3 Cu 3 Ti 4 O 12 (YCTO) were reflected as decrease in grain size and broadening of ε r – T peak with simultaneous decrease in ε r value. The presence of temperature dependent relaxation was also rationalized by impedance and modulus spectroscopic studies which confirm ferroelectric to paraelectric phase transition at 348 K. [ABSTRACT FROM AUTHOR]

Purpose:To develop and validate a real-time mitral valve annulus (MVA) tracking approach based on biplane transesophageal echocardiogram (TEE) data and magnetic tracking systems (MTS) to be used in minimally invasive off-pump beating heart mitral valve repair (MVR).Methods:The authors’ guidance system consists of three major components: TEE, magnetic tracking system, and an image guidance software platform. TEE provides real-time intraoperative images to show the cardiac motion and intracardiac surgical tools. The magnetic tracking system tracks the TEE probe and the surgical tools. The software platform integrates the TEE image planes and the virtual model of the tools and the MVA model on the screen. The authors’ MVA tracking approach, which aims to update the MVA model in near real-time, comprises of three steps: image based gating, predictive reinitialization, and registration based MVA tracking. The image based gating step uses a small patch centered at each MVA point in the TEE images to identify images at optimal cardiac phases for updating the position of the MVA. The predictive reinitialization step uses the position and orientation of the TEE probe provided by the magnetic tracking system to predict the position of the MVA points in the TEE images and uses them for the initialization of the registration component. The registration based MVA tracking step aims to locate the MVA points in the images selected by the image based gating component by performing image based registration.Results:The validation of the MVA tracking approach was performed in a phantom study and a retrospective study on porcine data. In the phantom study, controlled translations were applied to the phantom and the tracked MVA was compared to its “true” position estimated based on a magnetic sensor attached to the phantom. The MVA tracking accuracy was 1.29 ± 0.58 mm when the translation distance is about 1 cm, and increased to 2.85 ± 1.19 mm when the translation distance is about 3 cm. In the study on porcine data, the authors compared the tracked MVA to a manually segmented MVA. The overall accuracy is 2.37 ± 1.67 mm for single plane images and 2.35 ± 1.55 mm for biplane images. The interoperator variation in manual segmentation was 2.32 ± 1.24 mm for single plane images and 1.73 ± 1.18 mm for biplane images. The computational efficiency of the algorithm on a desktop computer with an Intel® Xeon® CPU @3.47 GHz and an NVIDIA GeForce 690 graphic card is such that the time required for registering four MVA points was about 60 ms.Conclusions:The authors developed a rapid MVA tracking algorithm for use in the guidance of off-pump beating heart transapical mitral valve repair. This approach uses 2D biplane TEE images and was tested on a dynamic heart phantom and interventional porcine image data. Results regarding the accuracy and efficiency of the authors’ MVA tracking algorithm are promising, and fulfill the requirements for surgical navigation. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this investigation is to determine if a single set of beam data, described by a minimal set of equations and fitting variables, can be used to commission different installations of a proton double-scattering system in a commercial pencil-beam dose calculation algorithm. Methods: The beam model parameters required to commission the pencil-beam dose calculation algorithm (virtual and effective SAD, effective source size, and pristine-peak energy spread) are determined for a commercial double-scattering system. These parameters are measured in a first room and parameterized as function of proton energy and nozzle settings by fitting four analytical equations to the measured data. The combination of these equations and fitting values constitutes the golden beam data (GBD). To determine the variation in dose delivery between installations, the same dosimetric properties are measured in two additional rooms at the same facility, as well as in a single room at another facility. The difference between the room-specific measurements and the GBD is evaluated against tolerances that guarantee the 3D dose distribution in each of the rooms matches the GBD-based dose distribution within clinically reasonable limits. The pencil-beam treatment-planning algorithm is commissioned with the GBD. The three-dimensional dose distribution in water is evaluated in the four treatment rooms and compared to the treatment-planning calculated dose distribution. Results: The virtual and effective SAD measurements fall between 226 and 257 cm. The effective source size varies between 2.4 and 6.2 cm for the large-field options, and 1.0 and 2.0 cm for the smallfield options. The pristine-peak energy spread decreases from 1.05% at the lowest range to 0.6% at the highest. The virtual SAD as well as the effective source size can be accurately described by a linear relationship as function of the inverse of the residual energy. An additional linear correction term as function of RM-step thickness is required for accurate parameterization of the effective SAD. The GBD energy spread is given by a linear function of the exponential of the beam energy. Except for a few outliers, the measured parameters match the GBD within the specified tolerances in all of the four rooms investigated. For a SOBP field with a range of 15 g/cm² and an air gap of 25 cm, the maximum difference in the 80%-20% lateral penumbra between the GBD-commissioned treatment-planning system and measurements in any of the four rooms is 0.5 mm. Conclusions: The beam model parameters of the double-scattering system can be parameterized with a limited set of equations and parameters. This GBD closely matches the measured dosimetric properties in four different rooms [ABSTRACT FROM AUTHOR]

Purpose: Expert manual labeling is the gold standard for image segmentation, but this process is difficult, time-consuming, and prone to inter-individual differences. While fully automated methods have successfully targeted many anatomies, automated methods have not yet been developed for numerous essential structures (e.g., the internal structure of the spinal cord as seen on magnetic resonance imaging). Collaborative labeling is a new paradigm that offers a robust alternative that may realize both the throughput of automation and the guidance of experts. Yet, distributing manual labeling expertise across individuals and sites introduces potential human factors concerns (e.g., training, software usability) and statistical considerations (e.g., fusion of information, assessment of confidence, bias) that must be further explored. During the labeling process, it is simple to ask raters to self-assess the confidence of their labels, but this is rarely done and has not been previously quantitatively studied. Herein, the authors explore the utility of self-assessment in relation to automated assessment of rater performance in the context of statistical fusion. Methods: The authors conducted a study of 66 volumes manually labeled by 75 minimally trained human raters recruited from the university undergraduate population. Raters were given 15 min of training during which they were shown examples of correct segmentation, and the online segmentation tool was demonstrated. The volumes were labeled 2D slice-wise, and the slices were unordered. A self-assessed quality metric was produced by raters for each slice by marking a confidence bar superimposed on the slice. Volumes produced by both voting and statistical fusion algorithms were compared against a set of expert segmentations of the same volumes. Results: Labels for 8825 distinct slices were obtained. Simple majority voting resulted in statistically poorer performance than voting weighted by self-assessed performance. Statistical fusion resulted in statistically indistinguishable performance from self-assessed weighted voting. The authors developed a new theoretical basis for using self-assessed performance in the framework of statistical fusion and demonstrated that the combined sources of information (both statistical assessment and self-assessment) yielded statistically significant improvement over the methods considered separately. Conclusions: The authors present the first systematic characterization of self-assessed performance in manual labeling. The authors demonstrate that self-assessment and statistical fusion yield similar, but complementary, benefits for label fusion. Finally, the authors present a new theoretical basis for combining self-assessments with statistical label fusion. [ABSTRACT FROM AUTHOR]

Purpose: New technology has been developed to treat age-related macular degeneration (AMD) using 100 kVp pencil-beams that enter the patient through the radio-resistant sclera with a depth of interest between 1.6 and 2.6 cm. Measurement of reference and relative dose in a kilovoltage x-ray beam with a 0.42 cm diameter field size and a 15 cm source to axis distance (SAD) is a challenge that is not fully addressed in current guidelines to medical physicists. AAPMˈs TG-61 gives dosimetry recommendations for low and medium energy x-rays, but not all of them are feasible to follow for this modality. Methods: An investigation was conducted to select appropriate equipment for the application. PTWˈs Type 34013 Soft X-Ray Chamber (Freiburg, Germany) and CIRSˈs Plastic Water LR (Norfolk, VA) were found to be the best available options. Attenuation curves were measured with minimal scatter contribution and thus called Low Scatter Tissue Air Ratio (LSTAR). A scatter conversion coefficient (Cscat) was derived through Monte Carlo radiation transport simulation using MCNPX (LANL, Los Alamos, NM) to quantify the difference between a traditional TAR curve and the LSTAR curve. A material conversion coefficient (Cmat) was determined through experimentation to evaluate the difference in attenuation properties between water and Plastic Water LR. Validity of performing direct dosimetry measurements with a source to detector distance other than the treatment distance, and therefore a different field size due to a fixed collimator, was explored. A method-Integrated Tissue Air Ratio (ITAR)-has been developed that isolates each of the three main radiological effects (distance from source, attenuation, and scatter) during measurement, and integrates them to determine the dose rate to the macula during treatment. Results: LSTAR curves were determined to be field size independent within the range explored, indicating that direct dosimetry measurements may be performed with a source to detector distance of 20 cm even though the SAD is 15 cm during treatment. Cscat varied from 1.102 to 1.106 within the range of depths of interest. The experimental variance among repeated measurements of Cmat was larger than depth dependence, so Cmat was estimated as1.019 for all depths of interest. Conclusions: Equipment selection, measurement techniques, and formalism for the determination of dose rate to the macula during stereotaxy for AMD have been determined and are strongly recommended by the authors of this paper to be used by clinical medical physicists. [ABSTRACT FROM AUTHOR]

Purpose: The main purposes of this study were to (1) investigate the dependency of lateral penumbra (80%-20% distance) of uniform scanning proton beams on various factors such as air gap, proton range, modulation width, compensator thickness, and depth, and (2) compare the lateral penumbra calculated by a treatment planning system (TPS) with measurements. Methods: First, lateral penumbra was measured using solid-water phantom and radiographic films for (a) air gap, ranged from 0 to 35 cm, (b) proton range, ranged from 8 to 30 cm, (c) modulation, ranged from 2 to 10 cm, (d) compensator thickness, ranged from 0 to 20 cm, and (e) depth, ranged from 7 to 15 cm. Second, dose calculations were computed in a virtual water phantom using the XiO TPS with pencil beam algorithm for identical beam conditions and geometrical configurations that were used for the measurements. The calculated lateral penumbra was then compared with the measured one for both the horizontal and vertical scanning magnets of our uniform scanning proton beam delivery system. Results: The results in the current study showed that the lateral penumbra of horizontal scanning magnet was larger (up to 1.4 mm for measurement and up to 1.0 mm for TPS) compared to that of vertical scanning magnet. Both the TPS and measurements showed an almost linear increase in lateral penumbra with increasing air gap as it produced the greatest effect on lateral penumbra. Lateral penumbra was dependent on the depth and proton range. Specifically, the width of lateral penumbra was found to be always lower at shallower depth than at deeper depth within the spread out Bragg peak (SOBP) region. The lateral penumbra results were less sensitive to the variation in the thickness of compensator, whereas lateral penumbra was independent of modulation. Overall, the comparison between the results of TPS with that of measurements indicates a good agreement for lateral penumbra, with TPS predicting higher values compared to measurements. Conclusions: Lateral penumbra of uniform scanning proton beams depends on air gap, proton range, compensator thickness, and depth, whereas lateral penumbra is not dependent on modulation. The XiO TPS typically overpredicted lateral penumbra compared to measurements, within 1 mm for most cases, but the difference could be up to 2.5 mm at a deep depth and large air gap. [ABSTRACT FROM AUTHOR]

Summary: In paired biopsies of osteoporotic women treated with either strontium ranelate or a placebo for 36 months, characteristics of bone apatite crystals were not influenced by the presence of strontium. The mean rate of substitutions of calcium by strontium ions was 4.5 %. Introduction: The potential effect of strontium (Sr) on bone apatite crystals was investigated in paired biopsies of osteoporotic women treated with either strontium ranelate (SrRan) or a placebo for 36 months. Methods: In ten paired biopsies, crystallinity, apparent length and width/thickness of crystals, interplanar distances, and lattice parameters of unit cells were assessed by X-ray diffraction and selected area electron diffraction. Results: All these parameters, reflecting crystal and unit cell characteristics, were not influenced by the presence of Sr and were similar in SrRan and placebo groups after 36 months of treatment. The mean rate of substitutions of calcium by Sr ions was 4.5 %. Conclusion: Overall, the quality of bone apatite crystals was maintained after 36 months of treatment with SrRan. [ABSTRACT FROM AUTHOR]

Nanoenabled drug carriers are emerging as alternatives to conventional small‐molecule drugs and their in‐vitro biocompatibility evaluation with blood components is a necessary part of early preclinical development. In the present study, Chitosan‐based bionanocomposites of sol–gel derived TiO2 and SiO2 were synthesised by the ex situ process. Samples were characterised by X‐ray diffraction, Fourier transformed infrared spectrophotometer, transmission electron microscopy and selected area electron diffraction techniques. The analysis reveals the formation of single‐phase oxides and their bionanocomposites. Haemolysis (destruction of red blood cell) study was performed by spectrophotometer to assess the haemocompatibility nature as a function of different incubation time. Experimental results reveal the percentage of haemolysis increase with the increase of the incubation time, but it was found to be <2%. This confirms our bionanocomposites are more haemocompatible as compared with respective nanocrystalline ceramics. Also, the interaction of our bionanocomposites with serum proteins at various incubation periods (1–24 h) were investigated using sodium dodecyl sulphate–polyacrylamide gel experiment, the obtained results were discussed in details. [ABSTRACT FROM AUTHOR]

Electron diffraction patterns obtained on a TEM contain elliptical distortion resulting from column defects. This distortion can be corrected by applying offsets to the objective lens stigmators to cancel distortions occurring further down the column. In this work, a DigitalMicrographTM script-based method has been developed to identify the optimum objective stigmator settings which produce a distortion minimum in diffraction. Initially, a manual (by eye) correction is used to determine the stigmator values necessary to bring the pattern distortion below the threshold at which it is no longer visible to the naked eye (<1%). Thereafter, an automated acquisition script is used to acquire matrices of diffraction patterns while varying the stigmator values about the values which were identified as producing a distortion minimum in the preceding step. This analysis can be applied iteratively to refine the location of the distortion minimum, using progressively finer step changes in objective stigmator values. The optimum stigmator values producing the distortion minimum in diffraction are very different to those in imaging. These imaging and diffraction stigmator values can be saved to script and subsequently recalled at the click of a button, making their application very simple. Using this method, diffraction pattern elliptical distortion in a newly installed TEM was reduced from 1.6% to 0.3%, on a measurement precision of 0.3%, effectively producing distortion-free diffraction. The relevant scripts can be freely downloaded from the internet. RESEARCH HIGHLIGHTS: This paper reports a DigitalMicrograph script-based method to identify and subsequently apply optimized objective stigmator values in diffraction mode. These effectively eliminate elliptical distortion inherent to this diffraction technique., (© 2022 The Author. Microscopy Research and Technique published by Wiley Periodicals LLC.)

Tetragonal, rhombohedral and monoclinic ferroelectric domains can all occur in morphotropic PbZr1− xTi xO3 (PZT) ceramics. In this article, the influence of these domains on the splitting of reflections in selected area electron diffraction (SAED) patterns along the main pseudo-cubic zone axes is reported. The orientation of the domain wall in a transmission electron microscopy image with respect to the splitting of reflections in the diffraction pattern has to be considered for the interpretation. The distinction of tetragonal and rhombohedral splitting is achieved for a pronounced splitting except for 〈111〉 with the domain wall edge on. As the monoclinic structure contains tetragonal as well as rhombohedral distortions, the distinction of monoclinic symmetry from tetragonal and rhombohedral based only on the splitting of reflections is not possible. Conceivable models of configurations of monoclinic subdomains inside the existing tetragonal or rhombohedral microdomains are derived from group-subgroup relations. Some experimental observations are given, which can only be explained by these models. [ABSTRACT FROM AUTHOR]

The distortions present in an electron diffraction pattern can be classified into two categories: one is radially invariant and the other is angularly invariant. We report a method to compensate these displacements undergone by diffraction features promoted by any kind of artifacts generated in parallel beam electron diffraction conditions. This approach is not aimed at quantifying these distortions but only intends to aid in the measurement of lattice parameters of crystals with a significant increase of accuracy and precision as compared to previous approaches. It is based on statistical estimations of the relative positions between diffraction rings and/or spots after performing a transformation of the digitalized patterns to polar coordinates. The analytical method is based on fitting a Gaussian type profile to intensity distributions. This makes it possible to determine the lattice parameters of a polycrystal or single crystal with relative errors smaller than 0.1% for diffractograms acquired in photographic films and below 0.01% for those collected in imaging plates. [ABSTRACT FROM AUTHOR]

Abstract: Pd particles supported on SnO2 and GeO2 have been structurally investigated by X-ray diffraction, (High-Resolution) transmission and scanning electron microscopy after different reductive treatments to monitor the eventual formation of bimetallic phases and catalytically tested in methanol dehydrogenation/reforming. For both oxides this included a thin film sample with well-defined Pd particles and a powder catalyst prepared by incipient wetness impregnation. The hexagonal and the tetragonal polymorph were studied for powder GeO2. Pd2Ge formation was observed on all GeO2-supported catalysts, strongly depending on the specific sample used. Reduction of the thin film at 573K resulted in full transformation into the bimetallic state. The partial solubility of hexagonal GeO2 in water and its thermal structural instability yielded Pd2Ge formation at 473K, at the cost of a structurally inhomogeneous support and Ge metal formation at higher reduction temperatures. Pd on tetragonal GeO2 entered a state of strong metal–support interaction after reduction at 573–673K, resulting in coalescing Pd2Ge particles on a sintered and re-crystallized support, apparently partially covering the bimetallic particles and decreasing the catalytic activity. Pd2Ge on amorphous thin film and hexagonal GeO2 converted methanol primarily via dehydrogenation to CO and H2. At 573K, formation of Pd2Sn and also PdSn occurred on the Pd/SnO2 thin film. Pd3Sn2 (and to some extent Pd2Sn) were predominantly obtained on the respective powder catalyst. Strong deactivation with increasing reduction temperature was observed, likely not based on the classical strong metal–support interaction effect, but rather on a combination of missing active structural ensembles on Sn-enriched bimetallic phases and the formation of metallic β-Sn. Correlations to Pd and its bimetallics supported on ZnO, Ga2O3 and In2O3 were also discussed. [Copyright &y& Elsevier]