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This study aimed to remove motion artifacts from brain magnetic resonance (MR) images using a U-Net model. In addition, a simulation method was proposed to increase the size of the dataset required to train the U-Net model while avoiding the overfitting problem. The volume data were rotated and translated with random intensity and frequency, in three dimensions, and were iterated as the number of slices in the volume data. Then, for every slice, a portion of the motion-free k-space data was replaced with motion k-space data, respectively. In addition, based on the transposed k-space data, we acquired MR images with motion artifacts and residual maps and constructed datasets. For a quantitative evaluation, the root mean square error (RMSE), peak signal-to-noise ratio (PSNR), coefficient of correlation (CC), and universal image quality index (UQI) were measured. The U-Net models for motion artifact reduction with the residual map-based dataset showed the best performance across all evaluation factors. In particular, the RMSE, PSNR, CC, and UQI improved by approximately 5.35×, 1.51×, 1.12×, and 1.01×, respectively, and the U-Net model with the residual map-based dataset was compared with the direct images. In conclusion, our simulation-based dataset demonstrates that U-Net models can be effectively trained for motion artifact reduction. [ABSTRACT FROM AUTHOR]

An indirect conversion X-ray detector uses a scintillator that utilizes the proportionality of the intensity of incident radiation to the amount of visible light emitted. A thicker scintillator reduces the patient's dose while decreasing the sharpness. A thin scintillator has an advantage in terms of sharpness; however, its noise component increases. Thus, the proposed method converts the spatial resolution of radiographic images acquired from a normal-thickness scintillation detector into a thin-thickness scintillation detector. Note that noise amplification and artifacts were minimized as much as possible after non-blind deconvolution. To accomplish this, the proposed algorithm estimates the optimal point-spread function (PSF) when the structural similarity index (SSIM) and feature similarity index (FSIM) are the most similar between thick and thin scintillator images. Simulation and experimental results demonstrate the viability of the proposed method. Moreover, the deconvolution images obtained using the proposed scheme show an effective image restoration method in terms of the human visible system compared to that of the traditional PSF measurement technique. Consequently, the proposed method is useful for restoring degraded images using the adaptive PSF while preventing noise amplification and artifacts and is effective in improving the image quality in the present X-ray imaging system. [ABSTRACT FROM AUTHOR]

• Immunogenicity and safety of EuTCV were evaluated in healthy participants (6 months to 45 years). • EuTCV showed a considerable immunogenicity with a mean 425-fold increase in anti-Vi IgG antibody titers. • EuTCV displayed reliable safety without causing serious treatment emergent adverse events. • Batch-to-batch consistency was confirmed in the evaluation of immunogenicity and safety. The typhoid conjugate vaccine (TCV) ensures a long-lasting protective immune response, requires fewer doses and is fit for children under 2 years of age. From Phase I study, EuTCV displayed considerable immunogenicity and reliable safety, thus endorsing further examination in Phase II/III trials. Therefore, a clinical Phase II/III study (NCT04830371) was conducted to evaluate its efficacy in healthy Filipino participants aged 6 months to 45 years through administration of the test vaccine (Arm A, B, and C) or comparator vaccine Typbar-TCV® (Arm D). Sera samples were collected pre-vaccination (Visit 1) and post-vaccination (Visit 4, Day 28) to assess the immunogenicity of EuTCV and Typbar-TCV®. During the study, participants were regularly monitored through scheduled visits to the clinic to report any adverse events associated with the vaccine. For vaccine safety, the proportion of solicited and unsolicited Treatment-Emergent Adverse Events was all comparable between EuTCV and Typbar-TCV® groups. A single dose of EuTCV produced seroconversion in 99.4% of treated participants, with seroconversion rates non-inferior to that of Typbar-TCV®. Batch-to-batch consistency was concluded based on the 90% Confidence Interval of the geometric mean ratio (EuTCV Arm A, B, and C) at Week 4, lying within the equivalence margin of 0.5 to 2.0 for all batches. Results from this Phase II/III clinical trial of EuTCV in healthy volunteers show comparable safety and considerable immunogenicity, compared to Typbar-TCV®, meeting the objectives of this pivotal study. ClinicalTrials.gov registration number: NCT04830371. [ABSTRACT FROM AUTHOR]

This study assessed the differences in muscle stiffness of the medial gastrocnemius (MG) and tibialis anterior (TA) muscles at rest and contraction during ovulation and follicular phase (menstruation) in women with regular menstrual cycle. Thirty‐four young healthy women (mean age 21.3 ± 1.3 years) with regular menstrual cycles participated in this study. Stiffness of the TA and MG muscles at rest and voluntary contraction during ovulation and follicular phase in young women were measured using shear‐wave elastography (SWE) and the handheld myotonometer MyotonPRO. The absolute stiffness difference between resting and contraction was expressed as the stiffness increase rate (SIR). The stiffness of the MG and TA at the resting position was not significantly different between the two phases of the menstrual cycle (p > 0.05). A significantly greater stiffness of both muscles measured using MyotonPRO in the follicular phase than during ovulation was found (p < 0.05), while stiffness measured by SWE showed a difference only in the TA muscle during contraction (p < 0.05). In addition, there were no significant differences in the SIR of both muscles between the two phases (p > 0.05). The results of our study showed a significantly greater stiffness of the MG and TA muscles at the follicular phase than at ovulation during contraction only. As muscle stiffness affects the risk of injury owing to reduced stability during sports activities, these changes in mechanical properties during the menstrual cycle should be noted, and training strategies should be used in female athletes. [ABSTRACT FROM AUTHOR]

Activated carbons play an essential role in developing new electrodes for renewable energy devices due to their electrochemical and physical properties. They have been the subject of much research due to their prominent surface areas, porosity, light weight, and excellent conductivity. The performance of electric double-layer capacitors (EDLCs) is highly related to the morphology of porous carbon electrodes, where high surface area and pore size distribution are proportional to capacitance to a significant extent. In this work, we designed and synthesized several activated carbons based on lignin for both supercapacitors and Li-S batteries. Our most favorable synthesized carbon material had a very high specific surface area (1832 m2·g−1) and excellent pore diameter (3.6 nm), delivering a specific capacitance of 131 F·g−1 in our EDLC for the initial cycle. This translates to an energy density of the supercapacitor cell at 55.6 Wh·kg−1. Using this material for Li-S cells, composited with a nickel-rich phosphide and sulfur, showed good retention of soluble lithium polysulfide intermediates by maintaining a specific capacity of 545 mA·h·g−1 for more than 180 cycles at 0.2 C. [ABSTRACT FROM AUTHOR]

Aim: To examine the associations between compassion competence and missed nursing care, professional quality of life and quality of life among clinical nurses. Background: Compassionate care has been demonstrated to have a positive impact on outcomes for patients, employees and organisations. However, little is known about the associations between compassion competence and missed nursing care, professional quality of life and quality of life among clinical nurses. Methods: A survey was conducted with 1,556 Korean clinical nurses. The associations between compassion competence and missed nursing care, professional quality of life and quality of life were examined using multivariate linear regression. Results: Compassion competence was negatively associated with missed nursing care and burnout but positively associated with compassion satisfaction, secondary traumatic stress and quality of life. Conclusions: Our results extend the literature on the significant influence of compassionate care by providing evidence of its positive effects on missed nursing care, compassion satisfaction, burnout and quality of life in clinical nurses. Implications for nursing management: Nursing managers should implement programmes to improve compassion competence in clinical nurses to address missed nursing care and burnout and improve compassion satisfaction and quality of life, thus improving quality of care, patient experience and patient safety. [ABSTRACT FROM AUTHOR]

The mitochondrial calcium uniporter (MCU) plays essential roles in mitochondrial calcium homeostasis and regulates cellular functions, such as energy synthesis, cell growth, and development. Thus, MCU activity is tightly controlled by its regulators as well as post-translational modification, including phosphorylation by protein kinases such as proline-rich tyrosine kinase 2 (Pyk2) and AMP-activated protein kinase (AMPK). In our in vitro kinase assay, the MCU N-terminal domain (NTD) was phosphorylated by protein kinase C isoforms (PKCβII, PKCδ, and PKCε) localized in the mitochondrial matrix. In addition, we found the conserved S92 was phosphorylated by the PKC isoforms. To reveal the structural effect of MCU S92 phosphorylation (S92p), we determined crystal structures of the MCU NTD of S92E and D119A mutants and analysed the molecular dynamics simulation of WT and S92p. We observed conformational changes of the conserved loop2-loop4 (L2-L4 loops) in MCU NTDS92E, NTDD119A, and NTDS92p due to the breakage of the S92-D119 hydrogen bond. The results suggest that the phosphorylation of S92 induces conformational changes as well as enhancements of the negative charges at the L2-L4 loops, which may affect the dimerization of two MCU-EMRE tetramers. [ABSTRACT FROM AUTHOR]

• Pulsatile pump is used to simulate pulsatile flow in several in-vitro experiments. • The desired physiological flow need to be output accurately in some experiments. • The developed pulsatile pump minimized the error through iterative control algorithm. In-vitro cardiovascular experiments provide an effective means for characterizing structural or hemodynamic features of medical devices before they are tested on animals or used in clinical practice. In-vitro experiments simulate complicated cardiovascular systems with blood pumps, vessels and valves, but without human or animal subjects. Therefore, such experiments are free from ethical issues and present large cost savings in comparison to in-vivo experiments. In this study, we aimed to design a fully programmable pulsatile flow pump that can consistently and accurately reproduce a wide range of physiological flow waveforms without costly transient flowmeter in the system. An iterative control algorithm (ICA) was used to minimize the differences between the desired and produced flow waveforms. Our results confirm that the developed pulsatile pump can replicate flow waveforms accurately, with root mean square errors (RMSEs) of 0.64 L/min and 0.52 mL for the flow rate and stroke volume, respectively. [ABSTRACT FROM AUTHOR]

This study aimed to develop and evaluate an improved median filter (IMF) with an adaptive mask size for light microscope (LM) images. We acquired images of the mouse first molar using a LM at 100× magnification. The images obtained using our proposed IMF were compared with those from a conventional median filter. Several parameters such as the contrast-to-noise ratio, coefficient of variation, no-reference assessments and peak signal-to-noise ratio were employed to evaluate the image quality quantitatively. The results demonstrated that the proposed IMF could effectively de-noise the LM images and preserve the image details, achieving a better performance than the conventional median filter. [ABSTRACT FROM AUTHOR]

Au/TiO 2 /GaN junctions with a TiO 2 interlayer were deposited at various oxygen pressures from 5 mTorr to 80 mTorr, and their surface, microstructural, and electrical properties were investigated. Compared with a single 5 μm-Si-doped GaN film on an (0001) Al 2 O 3 substrate, the 0.2 μm-Si-doped GaN film with an undoped GaN buffer layer demonstrated improved properties for the application to metal/semiconductor junctions. Atomic force microscope and tunneling electron microscope measurements suggested that the TiO 2 interlayer deposited at room temperature exhibited a distinctive change above the oxygen deposition pressure of 40 mTorr. In contrast to the small rectification ratio of 101-102 for Au/GaN junctions, the Au/TiO 2 /GaN junctions with the TiO 2 interlayers displayed a large rectification ratio of 106-107 when the oxygen pressure during the deposition of TiO 2 interlayer was maintained at 40 mTorr. These results suggest that the leakage current and the rectification behavior in a metal/oxide/semiconductor junction can be effectively controlled using the oxygen deposition pressure for an oxide interlayer. Image 1 • Investigation of surface and interface properties of oxide/semiconductor TiO 2 /GaN junction. • I–V characteristics of Au/TiO 2 /GaN junctions with TiO 2 interlayer oxygen deposition pressure. • Largely reduced leakage and improved rectification behavior by an insertion of oxide interlayer. • Controllable leakage current and rectification behavior with TiO 2 interlayer deposition pressure. [ABSTRACT FROM AUTHOR]

Background: Patient safety incidents lead to performance difficulties for nurses when providing nursing practice. This affects work-life balance and causes second and third-victimization. This study predicts factors affecting clinical nurses' work-life balance due to patient safety incidents using classification and regression tree analysis techniques. Methods: This study was a secondary analysis of data from a cohort research project, which used a descriptive survey for data collection. Participants comprised 372 nurses. Data were collected using SurveyMonkey, a mobile-based survey software solution, from January to September 2021. Data included the general characteristics of clinical nurses, second damage, second damage support, third damage, and work-life balance. The specific variables included in the analysis chosen through rigorous Lasso analysis form the foundation for predicting work-life balance. Variables with low explanatory power were excluded, thereafter, the variables selected by Lasso were analyzed with a classification and regression tree model to predict work-life balance. Results: A regression tree was applied to predict work-life balance using seven variables—education level, marital status, position, physical distress, second-victim support, turnover intentions, and absenteeism (selected through Lasso analysis). After pruning, at tree size four, when turnover intentions were < 4.250, physical distress < 2.875, and second-victim support < 2.345, the predicted work-life balance was 3.972. However, when turnover intentions were < 4.250, physical distress < 2.875, and second-victim support ≥ 2.345, then the predicted work-life balance was 2.760. Conclusions: This study's insights offer crucial groundwork for crafting targeted workforce risk management strategies and fostering a conducive organizational culture to mitigate nursing occupational stress, potentially curbing the recurrence of patient safety incidents and improving nursing practice while enhancing patient outcomes. Future research should explore second and third victim experiences across various healthcare settings globally to understand their impact on WLB and patient safety outcomes. [ABSTRACT FROM AUTHOR]

Abstract The dual-energy contrast-enhanced digital mammography (CEDM) system based on a photon counting detector (PCD) is very useful providing functional information for breast cancer detection. In particular, this system can be used to solve the spectral overlap and high radiation dose problems. However, imaging noise is a big problem because of the degradation image performance and cancer detection ratio in the CEDM system. To address this problem, a total variation (TV)-based denoising technique approach has recently been studied. Thus, the aim of this study was to evaluate and confirm the image performance of our TV-based denoising technique with dual-energy CEDM with a PCD. For this purpose, we simulated a dual-energy CEDM with a PCD and breast phantom in Monte Carlo simulation using the Geant4 Application for Tomographic Emission (GATE) that is an essential open source program. We also designed a TV-based denoising technique based on the L 1 -norm estimation included correction and iteration steps for acquiring high edge preservation in X-ray images. To evaluate the image performance, we used evaluation parameters with a contrast-to-noise ratio (CNR) and coefficient of variation (COV) as a function of the absorbed dose levels (2.18, 1.53, 1.09, and 0.66 mGy). According to the results, the average of all iodine thicknesses and absorbed dose conditions for the CNR using our proposed TV-based denoising technique was 1.71, 1.39, and 1.13 times higher than that acquired for the noisy image, median filter and Wiener filter, respectively. We also acquired excellent COV results for the dual-energy CEDM with a PCD system (2.53 times higher than that of the noisy image). In conclusion, the results of this study suggested that a TV-based denoising technique can be achieved with an improved image performance and the effect and feasibility of the TV-based denoising technique for dual-energy CEDM with a PCD can be investigated. Highlights • Monte Carlo simulation of CZT X-ray imaging system and breast phantom. • The noise reduction studies have been undertaken on a dual-energy CEDM with a CZT photon counting detector. • The comparison results using contrast-to-noise ratio and coefficient of variation confirms the noise reduction quality of total variation. [ABSTRACT FROM AUTHOR]

Abstract A color-sensitive and spectrometer-free sensing method using plasmonic nanohole arrays and the color components, L* , a* , and b* , of the CIELAB defined by the international commission on illumination (CIE) is introduced for the analysis of optically transparent materials in the visible range. Spectral analysis based on plasmonic nanoparticles or nanostructures can be applied to real-time bio-detection, but complex optical instrumentations and low spatial resolution have limited the sensing ability. Therefore, we take an advantage of color image processing instead of spectral analysis which induces the distinctive color information of plasmonic nanohole arrays with different transparent materials. It guarantees high spatial resolution which is essential to bio-detection such as living cells. To establish our sensing platform, the color components, L* , a* , and b* , were extracted from photo images by an image sensor, statistically processed using a JAVA program, and finally utilized as three individual sensing factors. Additionally, our study on a correlation between the spacing of plasmonic sensors and the color sensitivity to the refractive index reveals geometrically optimal conditions of nanohole arrays. The weighted mean calculation with the three individual sensing factors offers an enhanced distinction of the optical difference for transparent materials. In this work, a color sensitivity of 156.94 RIU−1 and a minimum mean absolute error of 1.298 × 10−4 RIU were achieved. The difference in the refractive index can be recognized up to 10−4 level with the suggested sensing platform and the signal process. This unique color-sensitive sensing method enables a simple, easy-to-control, and highly accurate analysis without complicated measurement systems including a spectrometer. Therefore, our sensing platform can be applied as a very powerful tool to in-situ label-free bio-detection fields. Highlights • Color-sensitive and spectrometer-free analysis using plasmonic sensors. • Simple and fast sensing based on pixel by pixel image processing. • Highly accurate prediction of the refractive index with the error of 0.0001298 RIU. [ABSTRACT FROM AUTHOR]

Abstract Photon counting spectral X-ray imaging system has many advantages compared with the conventional energy integrated X-ray imaging system. The photon counting room temperature semiconductor detector (PCRTSD) splits the energy spectrum into various energy ranges and can use the K-edge imaging technique for elemental composition of objects. However, despite its advantages, this system has limitations with respect to image noise. The aim of this study was to design a patch group-based nonlocal self-similarity prior learning denoising (PGPD) algorithm and to evaluate its image performance with K-edge imaging technique in the CdTe photon counting spectral X-ray imaging system. We simulated CdTe PCRTSD and X-ray source using Monte Carlo simulation using Geant4 Application for Tomographic Emission version 6, and applied the median filter and proposed PGPD denoising algorithms in the acquired phantom image. The denoising algorithm provided significant improvement in image performance (contrast to noise ratio and coefficient of variation) with K-edge imaging technique in PCRTSD. [ABSTRACT FROM AUTHOR]

The noise reduction algorithms have been widely used in the field of medical X-ray imaging system using semiconductor photon counting detector (PCD). Among these algorithms, fast non-local means (FNLM) method is based on use of the encoded information and considering the local region in the image. The aim of this study was to design FNLM noise reduction algorithm using acceleration function with Euclidean distance, which is feasible to cope with practical problems, and to confirm its application feasibility in CdTe PCD. We simulated X-ray imaging system with PCD using Monte Carlo simulation tool (Geant4 Application for Tomographic Emission (GATE)) version 6 and applied conventional and proposed noise reduction algorithms in acquired water phantom image. We conclude that the results of the image performances associated with noise characteristics demonstrated the superiority of the proposed FNLM noise reduction algorithm in CdTe PCD imaging system. [ABSTRACT FROM AUTHOR]

The development of novel noise-reduction algorithms is one of the main research areas in the field of medical diagnostic X-ray imaging. The purpose of this study is to develop an improved total-variation (TV) noise-reduction technique using a gradient method that employs an iteration counter, and confirm its feasibility for applications in chest and abdominal X-ray imaging systems. We evaluated image qualities using contrast–to–noise ratio (CNR) and relative standard deviation (RSD) calculations with the proposed and conventional noise-reduction algorithms for both chest and abdominal X-ray images. The results of the quantitative CNR and RSD evaluations demonstrated the superiority of the proposed TV noise-reduction technique over other algorithms; in particular, the comparison between the conventional and proposed TV techniques revealed that the proposed method has improved noise-reduction characteristics in all cases. In conclusion, the results demonstrated that the improved TV noise-reduction technique with the gradient method using the iteration counter can be used to acquire images with a better quality than those of conventional algorithms. This can lead to lowering of the radiation dose in chest and abdominal X-ray imaging systems. [ABSTRACT FROM AUTHOR]

This study investigated the relationship between uninterrupted time-on-task and academic success of students enrolled in a Massive Open Online Course (MOOC). The variables representing uninterrupted time-on-task, such as number and duration of uninterrupted consecutive learning activities, were mined from the log files capturing how 4286 students tried to learn Newtonian mechanics concepts in a MOOC. These variables were used as predictors in the logistic regression model estimating the likelihood of students getting a course certificate at the end of the semester. The analysis results indicate that the predictive power of the logistic regression model, which was assessed by Area Under the Precision-Recall Curve (AUPRC), depends on the value of off-task activity threshold time, and the likelihood of students getting a course certificate increases as students were doing more uninterrupted learning activities over a longer period of time. The findings from this study suggest that a simple count of learning activities, which has been used as a proxy for time-on-task in previous studies, may not accurately describe student learning in the computer-based learning environment because it does not reflect the quality, such as uninterrupted durations, of those learning activities. [ABSTRACT FROM AUTHOR]

In gamma-ray imaging, a collimator plays a crucial role in determining the sensitivity of the system and the spatial resolution of the acquired image. Herein, we presented a novel concept for a variable collimator in a pixelated photon-counting detector. The gamma-ray imaging system was modeled using the Monte Carlo simulation tool Geant4 Application for Tomographic Emission program. A detector using cadmium telluride and a 99m Tc point source was used. The collimators comprised three tungsten layers, and the septal height the beam finally penetrated from the incident gamma ray was adjusted differently. The first collimator layer constituted a hole with four times the pixel size, and the second and third layers comprised a hole with twice the pixel size, overlapping asymmetrically. Finally, the emitted gamma ray equaled the pixel. The spatial resolution showed different results depending on the source-to-collimator distance for each collimator configuration. Additionally, we determined that the sensitivity improved as the collimator height where gamma rays are incident and initially interact increased. We have proposed a novel collimator concept in a gamma-ray imaging system using a pixelated photon-counting detector, which may be applied in various fields in the future. [ABSTRACT FROM AUTHOR]

The resulting image obtained from an X-ray imaging system depends significantly on the characteristics of the detector. In particular, when an X-ray image is acquired by thinning the detector, a relatively large amount of noise inevitably occurs. In addition, when a thick detector is used to reduce noise in X-ray images, blurring increases and the ability to distinguish target areas deteriorates. In this study, we aimed to derive the optimal X-ray image quality by deriving the optimal noise reduction parameters based on the non-local means (NLM) algorithm. The detectors used were of two thicknesses (96 and 140 μm), and images were acquired based on the IEC 62220-1-1:2015 RQA-5 protocol. The optimal parameters were derived by calculating the edge preservation index and signal-to-noise ratio according to the sigma value of the NLM algorithm. As a result, a sigma value of the optimized NLM algorithm (0.01) was derived, and this algorithm was applied to a relatively thin X-ray detector system to obtain appropriate noise level and spatial resolution data. The no-reference-based blind/referenceless image spatial quality evaluator value, which analyzes the overall image quality, was best when using the proposed method. In conclusion, we propose an optimized NLM algorithm based on a new method that can overcome the noise amplification problem in thin X-ray detector systems and is expected to be applied in various photon imaging fields in the future. [ABSTRACT FROM AUTHOR]

Thallium bromide (TlBr) semiconductor materials are widely used to detect gamma rays. They have excellent detection efficiency owing to their high stopping and effective atomic number. The purpose of this study was to compare image quality using TlBr and conventional detector materials according to parallel-hole collimator geometry in gamma camera scintigraphy. The Geant4 application for tomographic emission (GATE) simulation tool was used. Cadmium telluride (CdTe), cadmium zinc telluride (CZT), and TlBr semiconductor materials were used; the parallel-hole collimator lengths were designed as 0.4, 0.6, 0.8, and 1.0 cm. For qualitative analysis, images were acquired using a quadrant-bar phantom with different bar thicknesses. Quantitative analyses, such as sensitivity (cps/MBq) and scatter fraction using a point source with 99m Tc of 1 mCi, were conducted. The sensitivity with TlBr material with collimator lengths of 0.4, 0.6, 0.8, and 1.0 cm was 2.38, 2.39, 2.39, and 2.36 times greater than with CdTe and CZT materials, and the scatter fraction with TlBr material was 1.26, 1.25, 1.24, and 1.31 times less than the scatter fraction with CdTe and CZT materials with the same collimator length, respectively. There was no significant difference in sensitivity and scatter fraction between CdTe and CZT materials. Thus, we confirmed that TlBr is a potential detector material with improved sensitivity and scatter fraction in gamma camera scintigraphy. [ABSTRACT FROM AUTHOR]

Anti-bacterial and anti-viral neuraminidase agents inhibit neuraminidase activity catalyzing the hydrolysis of terminal N -acetylneuraminic acid (Neu5Ac) from glycoconjugates and help to prevent the host pathogenesis that lead to fatal infectious diseases including influenza, bacteremia, sepsis, and cholera. Emerging antibiotic and drug resistances to commonly used anti-neuraminidase agents such as oseltamivir (Tamiflu) and zanamivir (Relenza) have highlighted the need to develop new anti-neuraminidase drugs. We obtained a serendipitous complex crystal of the catalytic domain of Clostridium perfringens neuraminidase ( Cp NanI CD ) with 2-(cyclohexylamino)ethanesulfonic acid (CHES) as a buffer. Here, we report the crystal structure of Cp NanI CD in complex with CHES at 1.24 Å resolution. Amphipathic CHES binds to the catalytic site of Cp NanI CD similar to the substrate (Neu5Ac) binding site. The 2-aminoethanesulfonic acid moiety and cyclohexyl groups of CHES interact with the cluster of three arginine residues and with the hydrophobic pocket of the Cp NanI CD catalytic site. In addition, a structural comparison with other bacterial and human neuraminidases suggests that CHES could serve as a scaffold for the development of new anti-neuraminidase agents targeting Cp NanI. [ABSTRACT FROM AUTHOR]

We demonstrate the growth of high-quality AlN layers on an AlN nanopillar structure with a patterned SiO 2 layer employing horizontal hydride vapor phase epitaxy (HVPE). The use of the AlN nanopillar structure with the patterned SiO 2 resulted in improving the crystalline, and overall material properties of the AlN layer. The full width half maximum (FWHM) of peaks corresponding to (002) and (102) reflections of the AlN layer with the nanopillar structure were significantly decreased from 386 and 576 arcsec to 265 and 318 arcsec, respectively, as compared with that of the as-grown AlN layer. The laterally overgrown AlN regions consisted of a continuous well-coalesced layer exhibiting a lower dislocation density than that of the templates used owing to the dislocation blocking and dislocation bending effects. Complementary characterization by transmittance, photoluminescence and Raman spectroscope, indicates further the overall good material properties of the AlN layer grown on the nanopillar structure. [ABSTRACT FROM AUTHOR]

Dual-energy contrast-enhanced digital mammography (CEDM) has been used to decompose breast images and improve diagnostic accuracy for tumor detection. However, this technique causes an increase of radiation dose and an inaccuracy in material decomposition due to the limitations of conventional X-ray detectors. In this study, we simulated the dual-energy CEDM with an energy-resolved photon-counting detector (ERPCD) for reducing radiation dose and improving the quantitative accuracy of material decomposition images. The ERPCD-based dual-energy CEDM was compared to the conventional dual-energy CEDM in terms of radiation dose and quantitative accuracy. The correlation between radiation dose and image quality was also evaluated for optimizing the ERPCD-based dual-energy CEDM technique. The results showed that the material decomposition errors of the ERPCD-based dual-energy CEDM were 0.56–0.67 times lower than those of the conventional dual-energy CEDM. The imaging performance of the proposed technique was optimized at the radiation dose of 1.09 mGy, which is a half of the MGD for a single view mammogram. It can be concluded that the ERPCD-based dual-energy CEDM with an optimal exposure level is able to improve the quality of material decomposition images as well as reduce radiation dose. [ABSTRACT FROM AUTHOR]

In this study, we estimated the characteristics of the optically stimulated luminescence dosimeter (OSLD), and confirmed the evaluation of the OSLD for intensity modulated radiation therapy (IMRT) dose verification. For the estimation of the characteristics of the OSLD, reproducibility, dose linearity, energy dependence, dose-rate dependence, and angular dependence were evaluated. To minimize the effect of the reproducibility on the other studies, we selected 17 OSLDs which had the reproducibility variation margin of ±1.5%. The result showed the linearity of the OSLD from 0.5 to 2 Gy, but from 2 to 6 Gy, supra-linearity was observed. The photon-rays and electron-rays energy dependences of the OSLD were ±1% and ±0.9%, respectively. The dose-rate dependences were ±0.4% for photon-rays, ±0.3% for electrons, and the angular dependence was ±0.7%. To estimate the evaluation of the OSLD for IMRT dose verification, 5 IMRT dose verification cases and 5 RapidArc dose verification cases were selected. The correction factors which were measured in the estimation of the characteristics of the OSLD were used in the dose conversion and the IMRT dose verification standard ±5% were increased to ±7%, because of the relatively high combined uncertainty of the OSLD. In this study, we estimate the characteristics of the OSLD in photon-rays and electron-rays, and confirm the evaluation of the OSLD for IMRT dose assessment through the logic flow chart, which concerned the size of the cancer and partiality of the radiation therapy center. [ABSTRACT FROM AUTHOR]

Yttrium-90 (Y-90) has attracted great attention as a therapeutic radionuclide because of higher emitted particle energy and pure beta emitter. In Y-90 bremsstrahlung imaging, NaI(Tl) and GSO detectors are widely used in detecting photon but these detectors cannot be easily applied to this imaging because of relatively low sensitivity. Among detector candidates, cadmium tungstate (CdWO 4 ) can acquire high detection efficiency due to the high density and good light yield. The purpose of this study was to evaluate the feasibility of gamma camera system with CdWO 4 detector for quantitation of Y-90 bremsstrahlung imaging using a Geant4 Application for Tomographic Emission (GATE). To evaluate performance of the imaging system, a Y-90 point source was designed in GATE simulation. These detectors using CdWO 4 , NaI(Tl), and GSO were equipped with low energy general purpose (LEGP), medium energy general purpose (MEGP), and high energy general purpose (HEGP) parallel-hole collimators. According to the results, the average sensitivities of the CdWO 4 detector with LEGP, MEGP, and HEGP were 43.76, 37.16, and 28.22 cps/MBq, respectively. In addition, the sensitivity was higher for CdWO 4 detector system than for NaI(Tl) or GSO detector systems for all parallel-hole collimator system with 55–285 keV energy window. However, differences of scatter fraction for three detectors were very similar. Our results showed that the effect and feasibility of CdWO 4 detector for Y-90 bremsstrahlung imaging can be investigated by a GATE simulation. In conclusion, the results of this study suggest that CdWO 4 detector can be achieved improved performance of Y-90 bremsstrahlung imaging. [ABSTRACT FROM AUTHOR]

The interaction of the rhomboid pseudoprotease Derlin-1 and p97 is crucial for the retrotranslocation of polyubiquitinated substrates in the endoplasmic reticulum-associated degradation pathway. We report a 2.25 Å resolution structure of the p97 N-terminal domain (p97N) in complex with the Derlin-1 SHP motif. Remarkably, the SHP motif adopts a short, antiparallel β-strand that interacts with the β-sheet of p97N-a site distinct from that to which most p97 adaptor proteins bind. Mutational and biochemical analyses contributed to defining the specific interaction, demonstrating the importance of a highly conserved binding pocket on p97N and a signature motif on SHP. Our findings may also provide insights into the interactions between other SHP-containing proteins and p97N. [ABSTRACT FROM AUTHOR]

Recently, significant effort has been spent on the development of photons counting detector (PCD) based on a CdTe for applications in X-ray imaging system. The motivation of developing PCDs is higher image quality. Especially, the K-edge subtraction (KES) imaging technique using a PCD is able to improve image quality and useful for increasing the contrast resolution of a target material by utilizing contrast agent. Based on above-mentioned technique, we presented an idea for an improved K-edge log-subtraction (KELS) imaging technique. The KELS imaging technique based on the PCDs can be realized by using different subtraction energy width of the energy window. In this study, the effects of the KELS imaging technique and subtraction energy width of the energy window was investigated with respect to the contrast, standard deviation, and CNR with a Monte Carlo simulation. We simulated the PCD X-ray imaging system based on a CdTe and polymethylmethacrylate (PMMA) phantom which consists of the various iodine contrast agents. To acquired KELS images, images of the phantom using above and below the iodine contrast agent K-edge absorption energy (33.2 keV) have been acquired at different energy range. According to the results, the contrast and standard deviation were decreased, when subtraction energy width of the energy window is increased. Also, the CNR using a KELS imaging technique is higher than that of the images acquired by using whole energy range. Especially, the maximum differences of CNR between whole energy range and KELS images using a 1, 2, and 3 mm diameter iodine contrast agent were acquired 11.33, 8.73, and 8.29 times, respectively. Additionally, the optimum subtraction energy width of the energy window can be acquired at 5, 4, and 3 keV for the 1, 2, and 3 mm diameter iodine contrast agent, respectively. In conclusion, we successfully established an improved KELS imaging technique and optimized subtraction energy width of the energy window, and based on our results, we recommend using this technique for high image quality. [ABSTRACT FROM AUTHOR]

COVID 19 -PEB is developed to simply detect SARS-CoV-2 by introducing FRET-based molecular beacon to the hACE2 receptor mimic peptide, which has excellent binding ability with the spike protein. This allows direct detection of SARS-CoV-2 without complicated pretreatment, and in particular, it is also very simple to check whether or not SARS-CoV-2 is infected. [Display omitted] • SARS-CoV-2 is causing an acute respiratory disease pandemic. • Selective and rapid testing is required to prevent further spread of the virus. • COVID 19-PEB based on FRET was developed for simple detection of SARS-CoV-2. • This allows direct detection of SARS-CoV-2 without complicated pretreatment. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has led to a pandemic of acute respiratory disease, namely coronavirus disease (COVID-19). This disease threatens human health and public safety. Early diagnosis, isolation, and prevention are important to suppress the outbreak of COVID 19 given the lack of specific antiviral drugs to treat this disease and the emergence of various variants of the virus that cause breakthrough infections even after vaccine administration. Simple and prompt testing is paramount to preventing further spread of the virus. However, current testing methods, namely RT-PCR, is time-consuming. Binding of the SARS-CoV-2 spike (S) glycoprotein to human angiotensin-converting enzyme 2 (hACE2) receptor plays a pivotal role in host cell entry. In the present study, we developed a hACE2 mimic peptide beacon (COVID19-PEB) for simple detection of SARS-CoV-2 using a fluorescence resonance energy transfer system. COVID19-PEB exhibits minimal fluorescence in its "closed" hairpin structure; however, in the presence of SARS-CoV-2, the specific recognition of the S protein receptor-binding domain by COVID19-PEB causes the beacon to assume an "open" structure that emits strong fluorescence. COVID19-PEB can detect SARS-CoV-2 within 3 h or even 50 min and exhibits strong fluorescence even at low viral concentrations, with a detection limit of 4 × 103 plaque-forming unit/test. Furthermore, in SARS-CoV-2-infected patient samples confirmed using polymerase chain reaction, COVID19-PEB accurately detected the virus. COVID19-PEB could be developed as a rapid and accurate diagnostic tool for COVID-19. [ABSTRACT FROM AUTHOR]

Photon-counting detectors allow spectral computed tomography (CT) imaging using energy-resolved information from a polychromatic X-ray spectrum. The spectral CT images based on the photon-counting detectors are dependent on the energy ranges defined by energy bins for image acquisition. In this study, K-edge and energy weighting imaging methods were experimentally implemented by using a spectral CT system with a cadmium zinc telluride (CZT)-based photon-counting detector. The spectral CT images were obtained by various energy bins and compared in terms of CNR improvement for investigating the effect of energy bins and the efficiency of the spectral CT imaging methods. The results showed that the spectral CT image quality was improved by using the particular energy bins, which were optimized for each spectral CT imaging method and target material. The CNR improvement was different for the spectral CT imaging methods and target materials. It can be concluded that an appropriate selection of imaging method for each target material and the optimization of energy bin can maximize the quality of spectral CT images. [ABSTRACT FROM AUTHOR]

Conversation among different types of design media is critical in providing haptic feedback within the architectural design loop. More attention needs to be given to creating a fully integrated design loop of digital architecture, where the gap between form in the virtual model and physical model is generally larger than it was in the pre-digital era due to the difficulty of the externalization of challenging forms via traditional methods. This study examines the significance of reciprocal relationships among different dimensions of design media including 2D drawings, digital models and physical models in design process. For a better understanding of the integrated design process, the characteristics and roles of these media are described particularly within the context of digital architecture. Three case studies of student work show a reconciled design conversation among three different types of media that contributed to the designer's haptic cognitive process offering not only visual serendipities but also suggestions on structure, material and assembly based on understanding the attributes of each medium. [ABSTRACT FROM AUTHOR]

Gamma ray imaging techniques that use a cadmium zinc telluride (CZT) or cadmium telluride (CdTe) pixelated semiconductor detectors have rapidly gained popularity as a key tool for nuclear medicine research. By using a pinhole collimator with a pixelated semiconductor gamma camera system, better spatial resolution can be achieved. However, this improvement in spatial resolution is accomplished with a decrease in the sensitivity due to the small collimator hole diameter. Furthermore, few studies have been conducted for novel parallel-hole collimator geometric designs with pixelated semiconductor gamma camera systems. A gamma camera system which combines a CZT pixelated semiconductor detector with a newly designed stack-up parallel-hole collimator was developed and evaluated. The eValuator-2500 CZT pixelated semiconductor detector (eV product, Saxonburg, PA) was selected for the gamma camera system. This detector consisted of a row of four CZT crystals of 12.8 mm in length with 3 mm in thickness. The proposed parallel-hole collimator consists of two layers. The upper layer results in a fourfold increase in hole size compared to a matched square hole parallel-hole collimator with an equal hole and pixel size, while the lower layer also consisted of fourfold holes size and pretty acts as a matched square hole parallel-hole collimator. The overlap ratios of these collimators were 1:1, 1:2, 2:1, 1:5, and 5:1. These collimators were mounted on the eValuator-2500 CZT pixelated semiconductor detector. The basic performance of the imaging system was measured for a 57 Co gamma source (122 keV). The measured averages of sensitivity and spatial resolution varied depending on the overlap ratios of the proposed parallel-hole collimator and source-to-collimator distances. One advantage of our system is the use of stacked collimators that can select the best combination of system sensitivity and spatial resolution. With low counts, we can select a high sensitivity collimator with a 1:5 or 5:1 overlap ratio. For high counts, a 1:1 overlap ratio collimator combination is the best selection at this time. In addition, if a higher system spatial resolution is needed, we can increase the spatial resolution by stacking additional thin collimators. These results demonstrate that the developed small pixelated semiconductor gamma camera system has high potential as an effective instrument for low energy gamma ray imaging. [ABSTRACT FROM AUTHOR]

The median modified Wiener filter (MMWF) algorithm, which is a combination of median and Wiener filters, was applied to reduce the noise signal contained in digital image systems. In this study, we investigated the effect of MMWF algorithm with mask sizes of 3 × 3, 5 × 5, 7 × 7, and 9 × 9 and compared it to the median and Wiener filters with a breast American College of Radiology (ACR) phantom designed using 3D printing technology. To compare the similarity between the conventional and 3D printed breast ACR phantoms at various tube voltages and tube currents, the peak signal-to-noise (PSNR) ratio was recorded. Then, the noise level of the mammographic X-ray image applied with the MMWF algorithm using various mask sizes and the conventional filtering methods were compared and evaluated. According to the results, when the MMWF algorithm using a mask size of 9 × 9 was applied to the X-ray phantom image, superior signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and coefficient of variation (COV) values were derived. In addition, by comparing the average values obtained using the conventional noise reduction methods, we confirmed that the SNR, CNR, and COV values obtained from the MMWF algorithm, using a 9 × 9 mask size, improved by 1.91, 2.29, and 4.77 times, respectively. In conclusion, applicability of the mammographic X-ray field after ACR phantom production using 3D printing technology was proven in this study. An optimal mask size of 9 × 9 for the MMWF algorithm was proposed for improving the image quality of the acquired image. [ABSTRACT FROM AUTHOR]

The filters used in X-ray systems affect the image quality and radiation dose. Although using filters has advantages in terms of image quality and dose, image noise increases because the amount of X-rays in the energy range of the entire area is reduced. Thus, a newly improved non-local means (INLM) denoising algorithm was modeled and applied to X-ray images based on the thickness of the aluminum (Al) filter, which is most commonly used in X-ray imaging systems, to prove its potential use. For X-ray image acquisition, a high-performance cadmium telluride material-based detector and a tube containing Al filters (1-, 3-, and 5-mm thickness) were designed. The proposed INLM denoising algorithm was modeled by including the improved weights for the gradient information for each pixel in the conventional NLM-based equation. When the proposed INLM denoising algorithm was applied to the acquired photon-counting X-ray images, results showed superior performance for both noise characteristics and no-reference-based image evaluation. In particular, we confirmed that when the INLM was applied to X-ray images using 5 mm Al thickness, noise characteristics and no-reference-based evaluation results were improved by approximately 1.36 times and 1.06 times, respectively, compared to the conventional NLM. The study proved that choosing the INLM in photon-counting X-ray images using 5 mm-thick Al filtration is vital for the success of image processing applications. [ABSTRACT FROM AUTHOR]

Lithium-sulfur (Li-S) batteries can provide at least three times higher energy density than lithium-ion (Li-Ion) batteries. However, Li-S batteries suffer from a phenomenon called the polysulfide shuttle (PSS) that prevents the commercialization of these batteries. The PSS has several undesirable effects, such as depletion of active materials from the cathode, deleterious reactions between the lithium anode and electrolyte soluble lithium polysulfides, resulting in unfavorable coulombic efficiency, and poor cycle life of the battery. In this study, a new sulfur cathode composed of graphitic nitride as the polysulfide absorbing material and reduced graphene oxide as the conductive carbon host has been synthesized to rectify the problems associated with the PSS effect. This composite cathode design effectively retains lithium polysulfide intermediates within the cathode structure. The S@RGO/GN cathode displayed excellent capacity retention compared to similar RGO-based sulfur cathodes published by other groups by delivering an initial specific capacity of 1415 mA h g−1 at 0.2 C. In addition, the long-term cycling stability was outstanding (capacity decay at the rate of only 0.2% per cycle after 150 cycles). [ABSTRACT FROM AUTHOR]

Hemodynamics in aortic dissection (AD) is closely associated with the risk of aortic aneurysm, rupture, and malperfusion. Altered blood flow in patients with AD can lead to severe complications such as visceral malperfusion. In this study, we aimed to investigate the effect of cannulation flow on hemodynamics in AD using a fluid–structure interaction simulation. We developed a specific-idealized AD model that included an intimal tear in the descending thoracic aorta, a re-entry tear in the left iliac artery, and nine branches. Two different cannulation methods were tested: (1) axillary cannulation (AC) only through the brachiocephalic trunk and (2) combined axillary and femoral cannulation (AFC) through the brachiocephalic trunk and the right common iliac artery. AC was found to result in the development of a pressure difference between the true lumen and false lumen, owing to the difference in the flow rate through each lumen. This pressure difference collapsed the true lumen, disturbing blood flow to the celiac and superior mesenteric arteries. However, in AFC, the pressure levels between the two lumens were similar, and no collapse occurred. Moreover, the visceral flow was higher than that in AC. Lastly, the stiffness of the intimal flap affected the true lumen's collapse. [ABSTRACT FROM AUTHOR]

Highlights: [•] Oligodendroglia uniquely provide metabolic support to neurons/axons. [•] The MCT1 lactate transporter is preferentially localized to oligodendroglia. [•] Loss of neuronal lactate supply by oligodendroglia leads to axon degeneration. [•] Oligodendroglial injury occurs in ALS. [•] Oligodendroglial–astroglial coupling may serve as metabolic support to neurons. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the influence of stand age class (I:<20 years old; II: 21–40 years old; III: 41–60 years old) on BEF and stem density and to develop allometric equations for the three stand age classes in order to estimate the biomass of pitch pine (Pinus rigidaMill.) plantations in South Korea. BEFs (g g−1) were observed to decrease in the three stand age classes with 1.983 for stand I, 1.201 for stand II and 1.131 for stand III. Results showed that there was a significant statistical difference in BEFs (p <0.05) among the stand age classes. The stem densities (g cm−3) of the three stands were 0.430, 0.451 and 0.481, respectively, and there was no significant statistical difference (p >0.05) among stand age classes. Both model 1 (DBH as predictor variable) and model 2 (DBH and total height as predictor variables) showed good results based on the model evaluation criteria (R2,RMSEandFI). The stem wood had the highest biomass distribution percentage of the three age classes with 52%, 67% and 69% determined for classes I, II and III, respectively. Stand age-dependent BEFs and allometric equations will help forest managers to accurately estimate the biomass and carbon stocks of the different pitch pine plantations in South Korea, which is essential in climate change mitigation. [ABSTRACT FROM AUTHOR]

In order to improve image quality in single-photon emission computed tomography (SPECT)/computed tomography (CT), various studies focusing on reconstruction methods and noise reduction algorithms have been conducted. Therefore, the purpose of this study was to evaluate the efficiency of the filtered back projection (FBP) and ordered subset expectation maximization (OSEM) reconstruction methods, and to evaluate image quality after applying the median modified Wiener filter (MMWF) as a complementary noise reduction filter using 3 × 3 and 5 × 5 mask sizes. The 3D Hoffman brain phantom was used, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were evaluated in regions of interest for quantitative analysis. Based on the results, the image quality obtained by the OSEM reconstruction method was 37.7% and 25.9% higher than that of the FBP reconstruction method regarding SNR and CNR, respectively. In addition, the average SNR and CNR values obtained by applying the MMWF algorithm were 35.9% and 17.1% higher than those without the MMWF algorithm. Therefore, our results indicate that the OSEM reconstruction method is more efficient than the FBP reconstruction method, and that the MMWF algorithm improves image quality in SPECT images, regardless of which reconstruction method is used. [ABSTRACT FROM AUTHOR]

In this study, we designed a photon-counting cadmium zinc telluride (CZT) gamma- and X-ray fusion imaging system and propose a new image processing method to improve image quality. The Geant4 Application for Tomographic Emission (GATE) platform was used to acquire gamma- and X-ray fusion images, and a stack-up parallel-hole collimator, which can greatly improve sensitivity, with a CZT detector was modeled. The newly proposed image processing algorithm to improve the image quality combines the median modified Wiener filter (MMWF), which can efficiently remove noise, and the Canny and Prewitt methods, which are representative edge detection algorithms. As a result, we confirmed that the two new algorithms improve noise and edge information compared to the conventional MMWF. In addition, when comparing the performance of the two proposed algorithms, we demonstrated that when the Canny is fused to MMWF, noise can be removed relatively efficiently, and the Prewitt can obtain improved edge information. The no-reference-based evaluation method was used to test these new algorithms with phantom images, with the same results. Thus, we demonstrate that the method combining MMWF and the edge detection algorithm provides superior image performance to the conventional filtering method in gamma- and X-ray fusion images with photon-counting CZT detectors. [ABSTRACT FROM AUTHOR]

Oligodendroglia support axon survival and function through mechanisms independent of myelination, and their dysfunction leads to axon degeneration in several diseases. The cause of this degeneration has not been determined, but lack of energy metabolites such as glucose or lactate has been proposed. Lactate is transported exclusively by monocarboxylate transporters, and changes to these transporters alter lactate production and use. Here we show that the most abundant lactate transporter in the central nervous system, monocarboxylate transporter 1 (MCT1, also known as SLC16A1), is highly enriched within oligodendroglia and that disruption of this transporter produces axon damage and neuron loss in animal and cell culture models. In addition, this same transporter is reduced in patients with, and in mouse models of, amyotrophic lateral sclerosis, suggesting a role for oligodendroglial MCT1 in pathogenesis. The role of oligodendroglia in axon function and neuron survival has been elusive; this study defines a new fundamental mechanism by which oligodendroglia support neurons and axons. [ABSTRACT FROM AUTHOR]

The article discusses a study which synthesized palladium nanoparticles supported on nitrogen-doped carbon nanofiber (N-CNF-H) by thermally decomposing Pd2(dba)3CHCl3 in the presence of N-CNF-H. The study found that the Pd/N-CNF-H compounds act as efficient catalysts in the partial hydrogenation of internal alkynes to the corresponding (Z)-alkenes. It also suggested the significance of N-CNF-H in the preparation of heterogenous poisoning catalysts.

The article focuses on research to immobilize platinum nanoparticles on the surface of nitrogen-doped, herringbone-type carbon nanofibers (N-CNF-H) with the formed Pt/N-CNF-H compounds becoming efficient poisoning catalysts for the nitro-selective hydrogenation of nitroarenes. Carbon-supported metal nanoparticles are used as sensors and electrocatalysts for lithium (Li) ion batteries. It involves synthesizing N-CNF-H using vapor deposition over an MgO supported Ni-Fe catalyst using hydrogen.

Abstract: In recent years, Korea’s Information and Communication Technology (ICT) industry has grown rapidly. The prosperity of the ICT industry has brought growing recognition that rising productivity and innovative performance have made major contributions to ensuring competitive advantage in international markets. In this context, recent studies stress the importance of external knowledge for improving both innovative performance and productivity. This paper empirically investigates the effects of firms’ external knowledge search behavior on their productivity as well as their innovative performance in the Korean ICT manufacturing sector. Based on firm-level data from the Science and Technology Policy Institute (STEPI), this study indicates that incremental innovation and productivity are both related to external knowledge search. [Copyright &y& Elsevier]

Noise reduction is a fundamental early stage in X-ray image performance evaluation. In this study, the median-modified Wiener filter (MMWF) algorithm based on a nonlinear adaptive spatial filter is compared to two general noise-reduction techniques using median and Wiener filters to confirm an excellent denoising approach in X-ray images. To acquire images, a high-resolution complementary metal–oxide–semiconductor (CMOS) radio-magnetic X-ray imaging system (exposure conditions: 100, 400, and 700 μ A) and rat phantom were used. The performances of the denoising methods were evaluated in terms of contrast-to-noise ratio (CNR), coefficient of variation (COV), and no-reference image quality assessment using the Blind/Referenceless Image Spatial Quality Evaluator (BRISQUE). The average results for CNR, COV, and BRISQUE in the acquired X-ray image using the MMWF algorithm were 1.08, 1.10, and 1.03 times higher than those of the noisy image, respectively. On average, the MMWF algorithm provided better image restoration than general noise-reduction techniques and was found to be most effective in relatively lower exposure conditions. [ABSTRACT FROM AUTHOR]

Digital breast tomosynthesis (DBT) is well-established in breast imaging modality to overcome the loss of depth-information in a three-dimension (3D) object in 2D mammography. However, the reconstructed DBT images suffer from shading artifacts caused by scatter radiation, beam-hardening effect, and unique geometric conditions. In this study, we investigated the application of a non-uniformity correction framework with TV-penalty in the DBT system for substantial improvement of its image visibility. We modeled a modified solver to estimate the non-uniformity field component, which is inspired by the normalized intensity-gradient joint-histogram-based energy minimization. The proposed framework was compared to the reference slice with only primary component in Monte-Carlo simulation and the uniformity was experimentally improved using the projection at low exposure condition. To quantitative evaluate image performance, percent integral uniformity (PIU) was calculated in acquired images. Our results indicated that the proposed framework well-operated to compensate for distorted flatness due to beam hardening, scatter, and unique DBT geometry. Especially, the measured PIU value of the corrected DBT slice was 14.2, it is almost same compared to that of mono-energy DBT slice (primary only) in simulation study. Moreover, the profile flatness of the corrected DBT slice was significantly improved from conventional DBT slice with much noise component. The uniformity correction of the DBT slice is necessary to reduce the misdiagnosis. Consequently, our results demonstrate that the proposed framework successfully corrects the non-uniformity at low X-ray exposure condition, and its scheme is expected to be applicable for efficient DBT imaging performance. [ABSTRACT FROM AUTHOR]

Presents a design algorithm for a withdrawal-weighted surface acoustic wave (SAW) transversal filter. Variables for the design of a withdrawal-weighted SAW; Sample performance specifications for a SAW intermediate frequency filter; Design algorithm that can determine all design parameters.

This study integrated a systematic analysis of instructional design and a sentiment analysis of student reviews of 18 courses from the Class Central Top 20 MOOCs to analyze the potential connections between instructional design quality and student reviews. The analysis of instructional design quality was based on the ten-principle framework. The results indicated that: 1) the instructional design quality of the highly-rated courses was in the medium-to-upper range; 2) there was a positive correlation between the instructional design quality and MOOCs ranking; 3) student sentiment was much more positive for Humanities courses compared to other subjects; 4) the student sentiment and MOOCs ranking had no significant correlation, but there was a positive correlation between student sentiment and the instructional design quality; and 5) the design of learning activities related to "Collaboration", "Differentiation" and "Collective knowledge" needed to be improved. The implications for practice and ideas for future research are outlined. [Display omitted] • The instructional design quality of the 18 courses was in the medium-to-upper level. • There was a positive correlation between the instructional design quality and the ranks of the 18 MOOCs. • Student sentiment was much more positive for Humanities compared to other subjects. • There was a significant positive correlation between student sentiment and the instructional design quality. • The design of learning activities related to the three principles "Collaboration", "Differentiation" and "Collective knowledge" need to be improved. [ABSTRACT FROM AUTHOR]

This study investigated health-related quality of life and identified factors affecting it among people with the HIV in South Korea. A total of 243 people living with HIV participated in this cross-sectional survey. Data were collected from five hospitals between November 2021 and August 2022 using structured online questionnaires. Data were analyzed using descriptive statistics, Mann-Whitney U test, Kruskal-Wallis test, Spearman's rho analysis, and Tobit regression analysis because a significant ceiling effect was observed for the dependent variable. The mean score for the health-related quality of life was 75.74 ± 16.48. The significant factors that positively influence the health-related quality of life were "employment" (B = 4.57, p =.035), "not participating in the self-help group" (B = 6.10, p =.004), "higher self-efficacy for managing symptoms" (B = 1.32, p =.036), "higher self-efficacy for getting support/help" (B = 0.95, p =.035), and "higher self-efficacy for managing fatigue" (B = 2.80, p <.001) in the Tobit regression analysis. The results suggest that interventions to increase self-efficacy should involve developing programs and policies for people living with HIV. There is a need for efforts to provide healthcare services linked to employment support, as well as to establish a social environment in which they can work without stigma. Further, self-help groups could be utilized as intervention channels. [ABSTRACT FROM AUTHOR]

In recent years, indirect digital radiography detectors have been actively studied to improve radiographic image performance with low radiation exposure. This study aimed to achieve low-dose radiation imaging with a thick scintillation detector while simultaneously obtaining the resolution of a thin scintillation detector. The proposed method was used to predict the optimal point spread function (PSF) between thin and thick scintillation detectors by considering image quality assessment (IQA). The process of identifying the optimal PSF was performed on each sub-band in the wavelet domain to improve restoration accuracy. In the experiments, the edge preservation index (EPI) values of the non-blind deblurred image with a blurring sigma of σ = 5.13 pixels and the image obtained with optimal parameters from the thick scintillator using the proposed method were approximately 0.62 and 0.76, respectively. The coefficient of variation (COV) values for the two images were approximately 1.02 and 0.63, respectively. The proposed method was validated through simulations and experimental results, and its viability is expected to be verified on various radiological imaging systems. [ABSTRACT FROM AUTHOR]