Layered ZrGeTe4is a new type of ternary anisotropic semiconductor material. The strong in-plane anisotropy may give us another degree of freedom for controlling electrical and optical properties and designing advanced nanodevices. Using both first-principles calculations and Raman spectroscopy, physical properties such as band structure, phonon vibration, and carrier mobility of layered ZrGeTe4from bulk to monolayer were investigated. The bulk and few-layer ZrGeTe4are predicted as indirect bandgap semiconductors, but the monolayer ZrGeTe4turns out to be a direct band gap semiconductor with moderate value of 1.08 eV. Detail calculations reveal that the van der Waals (vdW) interaction is the main reason of causing the transition from indirect band gap to direct one. Phonon calculations and Raman spectroscopy together demonstrate that the layered ZrGeTe4is mechanically stable and anisotropic. In orders of magnitude, the predicted carrier mobility of ZrGeTe4(∽103cm2V-1s-1) is between that of graphene (∽105) and MoS2(∽102), and the anisotropy of electronic mobility is similar to that of black phosphorus (BP), while hole mobility varies with the numbers of layers. © 2020 IOP Publishing Ltd.The IAEA is currently coordinating a multi-year project to update the TRS-398 Code of Practice for the dosimetry of external beam radiotherapy based on standards of absorbed dose to water. One major aspect of the project is the determination of new beam quality correction factors, k_Q, for megavoltage photon beams consistent with developments in radiotherapy dosimetry and technology since the publication of TRS-398 in 2000. Specifically, all values must be based on, or consistent with, the key data of ICRU Report 90. Data sets obtained from Monte Carlo (MC) calculations by advanced users and measurements at primary standard laboratories have been compiled for 23 cylindrical ionization chamber types, consisting of 725 MC-calculated and 179 experimental data points. These have been used to derive consensus k_Q values as a function of the beam quality index TPR _20,10 with a combined standard uncertainty of 0.6%. Mean values of MC-derived chamber-specific f_ch factors for cylindrical and plane-parallel chamber types in ^60Co beams have also been obtained with an estimated uncertainty of 0.4%. © 2020 Institute of Physics and Engineering in Medicine.In this work, the fouling resistance of TFC (thin film composite) nanofiltration membrane has been enhanced by electrostatically coupled SiO2 (silica dioxide) nanoparticles/poly(L-DOPA) (3-(3,4-dihydroxyphenyl)-l-alanine) antifouling coating. SiO2 nanoparticles were synthesized in different size ranges and combined with L-DOPA; and then coated as an anti-fouling layer on the membrane surface by recirculated deposition. Membranes were coated with S-NP (silica nanoparticles) in small (19.8 nm), medium (31.6 nm) and large (110.1 nm) size. The zwitterionic compound L-DOPA in the form of self-polymerized poly(L-DOPA) (PDOPA) helped in the attachment of the S-NP on to the membrane surface. It was confirmed by AFM (atomic force microscopy) measurement that coating of membranes led to an increase in hydrophilicity and reduction in surface roughness, which in turn led to a 60% reduction in adhesion force of foulant on the membrane as compared to the neat membrane. The modified membranes experienced almost no flux decline during the filtration experimental period, whereas the unmodified (neat) membrane showed sharp flux decline. The best coating conditions of silica nanoparticles resulting in the enhanced anti-fouling properties were identified. Biofouling film formation on the membranes were evaluated quantitatively by flow cytometry method. The results indicated that the modified membranes had 50% lower microbial population growth in terms of Total Event Count compared to the neat membrane. Overall, the experimental results have confirmed that the coating of electrostatically coupled SiO2 nanoparticles and PDOPA (S-NP/PDOPA) on TFC-NF (nanofiltration) membrane surface is effective in improving the fouling resistance of the membranes. This result has positive implications on reducing membrane fouling in the desalination and industrial wastewater treatment applications. © 2020 IOP Publishing Ltd.We report on Kelvin Probe Force Microscopy (KPFM) and Density Functional Theory (DFT) investigations of charge transfers in vertical heterojunctions between tungsten diselenide (WSe2) layers and graphene on silicon carbide substrates. The experimental data reveal the existence of an interface dipole, which is shown by DFT to originate from the neutralization of the graphene n-doping by an electron transfer towards the transition metal dichalcogenide (TMD) layer. The relative vacuum level shift probed by KPFM between the TMD and the substrate stays constant when passing from monolayer to bilayer graphene, which confirms that the Schottky-Mott model can be rigorously applied to these interfaces by taking into account the charge transfer from the substrate to the TMD. DFT calculations show that the first TMD layer absorbs almost all the excess charges contained in the graphene, and that the second TMD layer shall not play a significant role in the electrostatics of the system. Negatively charged defect at the TMD edges contribute however to the electrostatic landscape probed by KPFM on both TMD layers. © 2020 IOP Publishing Ltd.Epicardial adipose tissue (EAT) is a visceral fat deposit, that’s known for its association with factors, such as obesity, diabetes mellitus, age, and hypertension. Segmentation of the EAT in a fast and reproducible way is important for the interpretation of its role as an independent risk marker intricate. However, EAT has a variable distribution, and various diseases may affect the volume of the EAT, which can increase the complexity of the already time-consuming manual segmentation work. We propose a 3D deep attention U-Net method to automatically segment the EAT from coronary computed tomography angiography (CCTA). Five-fold cross-validation and hold-out experiments were used to evaluate the proposed method through a retrospective investigation of 200 patients. The automatically segmented EAT volume was compared with physician-approved clinical contours. Quantitative metrics used were the Dice similarity coefficient (DSC), sensitivity, specificity, Jaccard index (JAC), Hausdorff distance (HD), mean surface distance (MSD), residual mean square distance (RMSD), and the center of mass distance (CMD). For cross-validation, the median DSC, sensitivity, and specificity were 92.7%, 91.1%, and 95.1%, respectively, with JAC, HD, CMD, MSD, and RMSD are 82.9% ± 8.8%, 3.77 ± 1.86mm, 1.98 ± 1.50mm, 0.37 ± 0.24mm, and 0.65 ± 0.37mm, respectively. For the hold-out test, the accuracy of the proposed method remained high. We developed a novel deep learning-based approach for the automated segmentation of the EAT on CCTA images. We demonstrated the high accuracy of the proposed learning-based segmentation method through comparison with ground truth contour of 200 clinical patient cases using 8 quantitative metrics, Pearson correlation, and Bland-Altman analysis. Our automatic EAT segmentation results show the potential of the proposed method to be used in computer-aided diagnosis of coronary artery diseases (CADs) in clinical settings. © 2020 Institute of Physics and Engineering in Medicine.OBJECTIVE Instrumental identification of proximal scleroderma, which is necessary for the early diagnosis of systemic sclerosis (SSD), has not yet been developed. The aim of this study was to assess the potential diagnostic value of the imaging photoplethysmography (IPPG) method in patients with SSD. APPROACH The study enrolled 19 patients with SSD and 21 healthy subjects matched by age and sex with the patients. Spatial distribution of capillary-blood-flow parameters and their dynamics was estimated in the facial area of patients and subjects. In the IPPG system, a 40-s video of the subject’s face illuminated by green polarized light was recorded with a monochrome digital camera in synchronization with the electrocardiogram. Experimental data were processed by using custom software allowing assessment of an arrival time of the blood pressure wave (PAT), an amplitude of pulsatile component (APC) of the photoplethysmographic waveform, and their variability. MAIN RESULTS Our study has revealed significant increase of PAT variability in patients with SSD compared to the control group 52±47 ms vs 24±13 ms (P = 0.01). Similarly, the variability of PPG-pulse shape was larger in patients with SSD 0.13±0.07 % vs 0.09±0.02 % (P less then 0.001). In addition, patients with scleroderma showed significantly greater degree of asymmetry of APC parameter than the control group 17.7±9.7 vs 7.9±5.0 (P less then 0.001). At the same time, no correlation was found between the photoplethysmographic waveform parameters and either the form or duration of the disease. No relationship between the characteristics of the PPG waveform and the modified Rodnan skin score was found, as well. SIGNIFICANCE Novel instrumental markers found in our pilot study showed that the IPPG method can be used for diagnosing the systemic sclerosis in the early stages of the disease. © 2020 Institute of Physics and Engineering in Medicine.3D bioprinting may revolutionize the field of tissue engineering by allowing fabrication of bio-structures with high degree of complexity, fine architecture and heterogeneous composition. The printing substances in these processes are mostly based on biomaterials and living cells. As such, they generally possess weak mechanical properties and thus must be supported during fabrication in order to prevent the collapse of large, volumetric multi-layered printouts. In this work, we characterize a uniquely formulated media used to support printing of extracellular matrix-based biomaterials. We show that a hybrid material, comprised of calcium-alginate nanoparticles and xanthan gum, presents superb qualities that enable printing at high resolution of down to 10 microns, allowing fabrication of complex constructs and cellular structures. This hybrid also presents an exclusive combination of desirable properties such as biocompatibility, high transparency, stability at a wide range of temperatures and amenability to delicate extraction procedures. Moreover, as fabrication of large, volumetric biological structures may require hours and even days to accomplish, we have demonstrated that the hybrid medium can support prolonged, precise printing for at least 18 hours. All these qualities make it a promising support medium for 3D printing of tissues and organs. © 2020 IOP Publishing Ltd.INTRODUCTION The lack of rigorous quality standards in pre-clinical radiation dosimetry has renewed interest in the development of anthropomorphic phantoms. Using 3D printing customisable phantoms can be created to assess all parts of pre-clinical radiation research planning, image guidance and treatment delivery. We present the full methodology, including material development and printing designs, for the production of a high spatial resolution, anatomically realistic heterogeneous small animal phantom. METHODS A methodology for creating and validating tissue equivalent materials is presented. The technique is demonstrated through the development of a bone-equivalent material. This material is used together with a soft-tissue mimicking ABS plastic filament to reproduce the corresponding structure geometries captured from a CT scan of a nude mouse. Air gaps are used to represent the lungs. Phantom validation was performed through comparison of the geometry and X-ray attenuation of CT images of the phantom and animal images.