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The deposition of beta-amyloid (Aβ) in the brain precedes the onset of symptoms such as cognitive impairment in Alzheimer’s disease (AD); therefore, the early detection of Aβ accumulation is crucial. We previously reported the applicability of the QPLEXTM Alz plus assay kit for the prescreening of Aβ accumulation. Here, we tested the specific application of the kit in a large cohort of cognitively normal (CN) individuals of varying ages for the early detection of Aβ accumulation. We included a total of 221 CN participants with or without brain Aβ. The QPLEXTM biomarkers were characterized based on age groups (1st–3rd tertile) and across various brain regions with cerebral amyloid deposition. The 3rd tertile group (>65 years) was found to be the most suitable age group for the application of our assay kit. Receiver operating characteristic curve analysis showed that the area under the curve (AUC, discrimination power) was 0.878 with 69.7% sensitivity and 98.4% specificity in the 3rd tertile group. Additionally, specific correlations between biomarkers and cerebral amyloid deposition in four different brain regions revealed an overall correlation with general amyloid deposition, consistent with previous findings. Furthermore, the combinational panel with plasma Aβ1–42 levels maximized the discrimination efficiency and achieved an AUC of 0.921 with 95.7% sensitivity and 67.3% specificity. Thus, we suggest that the QPLEXTM Alz plus assay is useful for prescreening brain Aβ levels in CN individuals, especially those aged >65 years, to prevent disease progression via the early detection of disease initiation.

Attenuation correction (AC) and scatter correction (SC) are essential steps for accurate PET quantification in positron emission tomography (PET)/computed tomography (CT) and PET/magnetic resonance (MR) imaging. SC with a single scatter simulation (SSS) algorithm is usually performed by employing an attenuation map using CT and MR data for AC. The purpose of this study was to evaluate the effect of SC using a SSS algorithm with CT- and MR-based attenuation maps in phantom and volunteer studies for 18F-FDG brain PET. We investigated the effect of the SC on two MR-based attenuation maps, which included a four-segmentation Dixon (soft tissue, fat, lung, and air) and a five-segmentation Model, which is Dixon plus bone, and we compared those maps with a standard CT-based attenuation map. In the phantom study, the difference in (%) recovery coefficients before and after SC for a CT-based attenuation correction (CTAC) and a MR-based attenuation correction (MRAC) were 20.36 and 21.01, respectively. The difference in the scatter fractions on the sinogram was about 2% between the CTAC and the MRAC (Dixon). In the volunteer study, the scatter fractions were 24.08 for the CT, 23.09 for the Dixon, and 23.11 for the Model. The bias in the scatter ratio image, after calculating the before and after SCs from the PET images, between the CTAC and the two MRACs was less than 1% (% MAE = 0.43 for CT-Dixon and 0.39 for CT-Model). A voxel-wise analysis of the scatter ratio before and after the SC from PET images showed no significant differences between the CTAC and the two MRACs (p > 0.05). We found that despite the different attenuation maps, the difference in the effects of the SC between the two MR and the CT attenuation maps was minimal. This implies that the SC obtained using the SSS algorithm was rarely affected by the attenuation map.

Alzheimer’s disease (AD) is the leading cause of dementia, and many studies have focused on finding effective blood biomarkers for the accurate diagnosis of this disease. Predicting cerebral amyloid deposition is considered the key for AD diagnosis because a cerebral amyloid deposition is the hallmark of AD pathogenesis. Previously, blood biomarkers were discovered to predict cerebral amyloid deposition, and further efforts have been made to increase their sensitivity and specificity. In this study, we analyzed blood-test factors (BTFs) that can be commonly measured in medical health check-ups from 149 participants with cognitively normal, 87 patients with mild cognitive impairment, and 64 patients with clinically diagnosed AD dementia with brain amyloid imaging data available. We demonstrated that four factors among regular health check-up blood tests, cortisol, triglyceride/high-density lipoprotein cholesterol ratio, alanine aminotransferase, and free triiodothyronine, showed either a significant difference by or correlation with cerebral amyloid deposition. Furthermore, we made a prediction model for Pittsburgh compound B-positron emission tomography positivity, using BTFs and the previously discovered blood biomarkers, the QPLEXTM Alz plus assay kit biomarker panel, and the area under the curve was significantly increased up to 0.845% with 69.4% sensitivity and 90.6% specificity. These results show that BTFs could be used as co-biomarkers and that a highly advanced prediction model for amyloid plaque deposition could be achieved by the combinational use of diverse biomarkers., Alzheimer’s disease: routine blood-test results could assist early diagnosis Four blood components measured in routine tests may highlight the cerebral protein build-up indicative of Alzheimer’s disease and could improve diagnosis. Amyloid protein plaque accumulation in the brain is a hallmark of Alzheimer’s, and early detection prior to symptoms appearing is invaluable. PET imaging is currently used for detecting plaque deposition, but scientists are developing simpler detection methods using blood biomarkers such as amyloid peptide levels. Haeng Jun Kim at Seoul National University, South Korea, and co-workers demonstrated that biomarker test accuracy could be boosted by including routine blood-test data. They correlated PET imaging data with blood results from patients with mild cognitive impairment, Alzheimer’s, and healthy controls. They identified components whose levels are associated with amyloid deposition, including a liver enzyme and the hormone cortisol, and developed a proof-of-concept plaque prediction model.

In this study, we compared the signal-to-noise ratio (SNR) and the geometric accuracy between conventional-bore and wide-bore 3-T magnetic resonance imaging (MRI) by using both balanced fast field echo (bFFE) and turbo spin-echo (TSE) pulse sequences with a large field of view (FOV). A large-diameter phantom was scanned using clinical 60-cm conventional-bore and 70-cm wide-bore scanners. The signal-to-noise ratios (SNRs) of both the bFFE and the TSE pulse sequences were calculated for each MR scanner for various acceleration factors (AFs). The diameter of the phantom was measured in four directions to evaluate the geometric accuracy. The SNR values were found to increase as the FOV increased for both the conventional- and the wide-bore scanners. No statistically significant differences in the SNR and the geometric accuracy were observed in either sequences between the two bores (p > 0.05), although the image noise tended to increase as the AF of both bores increased. Wide-bore MRI using a large FOV can provide a SNR and a geometric accuracy comparable to those of conventional-bore MRI, despite the increase in the image noise as the AF of both bores is increased.

This study compared sensitivity encoding (SENSE) and compressed sensing sensitivity encoding (CS-SENSE) for phase oversampling distance and assessed its impact on image quality and image acquisition time. The experiment was performed with a large diameter phantom using 16-channel anterior body coils. All imaging data were divided into three groups according to the parallel imaging technique and oversampling distances: groups A (SENSE with phase oversampling distance of 150 mm), B (CS-SENSE with phase oversampling distance of 100 mm), and C (CS-SENSE with phase oversampling distance of 75 mm). No statistically significant differences were observed among groups A, B, and C regarding both T2 and T1 turbo spin-echo (TSE) sequences using an acceleration factor (AF) of 2 (p = 0.301 and 0.289, respectively). In comparison with AF 2 of group A, the scan time of AF 2 of groups B and C was reduced by 11.2% and 23.5% (T2 TSE) and 15.8% and 22.7% (T1 TSE), respectively, while providing comparable image quality. Significant image noise and aliasing artifact were more evident at AF

The deposition of beta-amyloid (Aβ) in the brain precedes the onset of symptoms such as cognitive impairment in Alzheimer's disease (AD); therefore, the early detection of Aβ accumulation is crucial. We previously reported the applicability of the QPLEX

We tested the accuracy of the relaxation times T1 and T2 of MAGiC magnetic resonance imaging (MRI) by using a synthetic technique and comparing them with those obtained from conventional spin echo MRI. A phantom using a gadolinium contrast agent was produced and utilized to increase the accuracy of the measurement by minimizing the susceptibility effects that occurred in in-vivo experiments. This study showed that T2 mapping of MAGiC MRI has an error by comparing T1 and T2 of MAGiC MRI with those of conventional spin echo MRI, which provides the most accurate mapping value.

Computed tomography (CT) quality control (QC) is regularly performed with standard phantoms, to bar faulty equipment from medical use. Its accuracy may be improved by replacing qualitative methods based on good visual distinction with pixel value-based quantitative methods. We hypothesized that statistical texture analysis (TA) that covers the entire phantom image would be a more appropriate tool. Therefore, our study devised a novel QC method based on the TA for contrast resolution (CR) and spatial resolution (SR) and proposed new, quantitative CT QC criteria. TA of CR and SR images on an American Association of Physicists in Medicine (AAPM) CT Performance Phantom were performed with nine CT scanner models. Six texture descriptors derived from first-order statistics of grayscale image histograms were analyzed. Principal component analysis was used to reveal descriptors with high utility. For CR evaluation, contrast and softness were the most accurate descriptors. For SR evaluation, contrast, softness, and skewness were the most useful descriptors. We propose the following ranges: contrast for CR, 29.5 ± 15%, for SR, 29 ± 10%, softness for CR, &lt, 0.015, for SR, &lt, 0.014, and skewness for SR, &gt, −1.85. Our novel TA method may improve the assessment of CR and SR of AAPM phantom images.

BackgroundThe deposition of beta-amyloid (Ab) in the brain precedes the onset of symptoms such as cognitive abnormality in Alzheimer’s disease (AD); therefore, it is best to detect Ab accumulation early as possible.MethodsWe previously reported that QPLEXTM Alz plus assay could be used for pre-screening of Ab accumulation in the brain. In this study, we applied QPLEXTM Alz plus assay kit to the cognitively normal (CN) group for the brain Ab positivity. Total 221 CN participants with or without brain Ab were included. ResultsReceiver operating characteristics (ROC) curve analysis showed that the discrimination power reached 0.878 area under curve (AUC) with 69.7% sensitivity and 98.4% specificity in the CN group over 65 years. Conclusions We suggest that QPLEXTM Alz plus assay is a useful method for pre-screening brain Ab in the CN group, especially over 65 years, to prevent disease progression by early detection of disease initiation.

In this study, we assessed how image quality depends on the angle of tilt of a flex tilt coil supporting device during an MRI examination. All measurements were performed with an American College of Radiology (ACR) MRI phantom using a flex tilt coil supporting device. All images were analyzed using an automatic assessment method following the ACR MRI accreditation guidance. Image quality was compared between acquisitions grouped according to the angle of tilt of the coil supporting device: group A (Flat mode), group B (10˚), and group C (18˚). All measured image qualities were within the ACR recommended criteria, regardless of the angle of tilt of the flex tilt coil supporting device. However, statistically significant differences between the three groups were found for slice thickness, position accuracy, image intensity uniformity, and SNR (P

Background Alzheimer’s disease (AD) is an irreversible neurodegenerative disease characterized by the hallmark finding of cerebral amyloid deposition. Many researchers have tried to predict the existence of cerebral amyloid deposition by using easily accessible blood plasma samples, but the effectiveness of such strategies remains controversial. Methods We developed a new multiplex kit, the QPLEX™ Alz plus assay kit, which uses proteomics-based blood biomarkers to prescreen for cerebral amyloid deposition. A total of 300 participants who underwent Pittsburgh compound B (PiB)-positron emission tomography (PET) which allows imaging of cerebral amyloid deposition were included in this study. We compared the levels of QPLEX™ biomarkers between patients who were classified as PiB-negative or PiB-positive, regardless of their cognitive function. Logistic regression analysis followed by receiver operating characteristic (ROC) curve analysis was performed. The kit accuracy was tested using a randomized sample selection method. Results The results obtained using our assay kit reached 89.1% area under curve (AUC) with 80.0% sensitivity and 83.0% specificity. Further validation of the QPLEX™ Alz plus assay kit using a randomized sample selection method showed an average accuracy of 81.5%. Conclusions Our QPLEX™ Alz plus assay kit provides preliminary evidence that it can be used as blood marker to predict cerebral amyloid deposition but independent validation is needed.

Background: Alzheimer's disease (AD) is an irreversible neurodegenerative disease characterized by the hallmark finding of cerebral amyloid deposition. Many researchers have tried to predict the existence of cerebral amyloid deposition by using easily accessible blood plasma samples, but the effectiveness of such strategies remains controversial. Methods: We developed a new multiplex kit, the QPLEXTM Alz plus assay kit, which uses proteomics-based blood biomarkers to prescreen for cerebral amyloid deposition. A total of 300 participants who underwent Pittsburgh compound B (PiB)-positron emission tomography (PET) which allows imaging of cerebral amyloid deposition were included in this study. We compared the levels of QPLEXTM biomarkers between patients who were classified as PiB-negative or PiB-positive, regardless of their cognitive function. Logistic regression analysis followed by receiver operating characteristic (ROC) curve analysis was performed. The kit accuracy was tested using a randomized sample selection method.Results: The results obtained using our assay kit reached 89.1% area under curve (AUC) with 80.0% sensitivity and 83.0% specificity. Further validation of the QPLEXTM Alz plus assay kit using a randomized sample selection method showed an average accuracy of 81.5%.Conclusions: Our QPLEXTM Alz plus assay kit offers a highly effective way to predict cerebral amyloid deposition through a convenient blood test, and should enable easy prediction of AD in daily life.

Purpose To identify independent patient factors associated with an increased radiation dose, and to evaluate the effect of patient position on the effective dose in abdominal digital radiography. Materials and Methods We retrospectively evaluated the effective dose for abdominal digital radiography in 222 patients. The patients were divided into two groups based on the cut-off dose value of 0.311 mSv (the upper third quartile of dose distribution): group A (n = 166) and group B (n = 56). Through logistic regression, independent factors associated with a larger effective dose were identified. The effect of patient position on the effective dose was evaluated using a paired t-test. Results High body mass index (BMI) (≥ 23 kg/m2), presence of ascites, and spinal metallic instrumentation were significantly associated with a larger effective dose. Multivariate logistic regression analysis revealed that high BMI [odds ratio (OR), 25.201; p < 0.001] and ascites (OR, 25.132; p < 0.001) were significantly associated with a larger effective dose. The effective dose was significantly lesser (22.6%) in the supine position than in the standing position (p < 0.001). Conclusion High BMI and ascites were independent factors associated with a larger effective dose in abdominal digital radiography. Significant dose reduction in patients with these factors may be achieved by placing the patient in the supine position during abdominal digital radiography.

In recent years, unmanned aerial vehicles (UAVs) have been developed and studied for various applications, including drone deliveries, broadcasting, scouting, crop dusting, and firefighting. To enable the wide use of UAVs, their exact aeroacoustic characteristics must be assessed. In this study, a noise prediction method for a ducted fan UAV with complicated geometry was developed. In general, calculation efficiency is increased by simulating a ducted fan UAV without the struts that fix the fuselage to the ducts. However, numerical predictions of noise and aerodynamics differ according to whether struts are present. In terms of aerodynamic performance, the total thrust with and without struts is similar owing to the tendency of the thrust of a blade to offset the drag of the struts. However, in aeroacoustic simulations, the strut effect should be considered in order to predict the UAV’s noise because noise from the blades can be changed by the strut effect. Modelling of the strut effect revealed that the dominant tonal noises were closely correlated with the blade passage frequency of the experimental results. Based on the successful detection of noise sources from a ducted fan UAV system, using the proposed noise contribution contour, methods for noise reduction can be suggested by comparing numerical results with measured noise profiles.

Purpose Dose reduction using additional filters with high kilovoltage peak (kVp) for abdominal digital radiography has received much attention recently. We evaluated image quality with dose reduction in abdominal digital radiography by using high kVp and additional copper filters at a tertiary hospital. Methods Between June 2016 and July 2016, 82 patients underwent abdominal digital radiography using 80 kVp in X-ray room 1 and 82 were imaged using 92 kVp with 0.1-mm copper filtration in X-ray room 2. The effective dose was calculated using a PC-based Monte Carlo program. Image quality of the abdominal radiography acquired in the two rooms was evaluated using a five-point ordinal scale, as well as the signal-to-noise and contrast-to-noise ratios. Results The mean effective dose decreased by 25.8% and 25.7% for the supine and standing positions, respectively, when abdominal digital radiography using 92 kVp with 0.1-mm copper filtration was performed. In the 20 patients who performed abdominal digital radiography twice in each room, visual grading scores for visualisation of psoas outlines and kidney outlines are higher in room 1. However, there was no statistical significant difference of visual grading scores among the 124 patients who underwent only one abdominal radiography in the room 1 or 2 (P > 0.05). Conclusions Dose reduction for abdominal digital radiography can be achieved with comparable image quality by performing abdominal digital radiography using 92 kVp with 0.1-mm copper filtration, despite the higher AEC dose.

The fuselage of a helicopter is strongly affected by the rotor and its wake under hovering and low-speed forward flight conditions. Unsteady loading is observed on the fuselage surface owing to the blade passing effect and periodic collision of the wake vortices. Panel and vortex methods were combined for simulating rotor–fuselage aerodynamic interaction. Although the panel method involves the use of Bernoulli's equation to obtain the surface pressure, it is difficult to consider the increase in stagnation pressure in the vortical flow region under the rotor. In this study, an integral solution of the Poisson equation was adopted to calculate the pressure at the surface of the fuselage. The flow around the Georgia Institute of Technology's rotor–fuselage model was simulated to demonstrate the increase in stagnation pressure along the topline of the fuselage, during which unsteady loading caused by tip vortex impingement was observed. The ROBIN (rotor body interaction) model, which considers a generic helicopter fuselage, was also used to analyze the unsteady pressures at the top and the side of the fuselage. For the models, the Poisson equation was found to accurately predict both unsteady pressure fluctuation and stagnation pressure increase on the fuselage in the presence of the rotor wake without any special treatment.

Idiopathic condylar resorption (ICR), also known as idiopathic condylysis or condylar atrophy, is multifactorial pathology leading to severe mandibular retrognathism. The etiology has been shown to be multifactorial, such as avascular necrosis, traumatic injuries, hormone and autoimmune disease and it is largely difficult to distinguish the exact cause in each individual. In spite of the remarkable morphological alteration, surgical intervention is not readily recruited due to the possibility of recurrence of resorption. In order to restore balanced facial profile and occlusion. In this report, we present a camouflage treatment for skeletal Class II with ICR and facial asymmetry involving total arch movement, for the improvement facial profile and reconstruction of occlusion.

고리를 합성하는 여러 가지 방법을 연구 개발 하였다. 본 연구는 상업적으로 가격이 저렴한 benzyl amine과 acid chloride 유도체 화합물을이용하여 다양한 α, β, γ-lactam 고리 화합물을 만들어 보는데 목적이 있다. 즉, N-benzylchloroamide의 carbonyl과chloride가 붙은 탄소위치에 따라 intramolecular cyclization을통해 α, β, γ-lactam 유도체를 다양하게 합성 하였다.Fig. 1에서 보는 것처럼, N-benzylchloroamide 을 염기처리하면 amide의 nitrogen에 붙어 있는 수소를 제거하여aminolate중간체 를 생성시킬 수 있다. 형성된 aminolate 중간체를 intramolecular N-cyclization 방법을 이용하면 amide의carbonyl과 chloride 사이를 연결하는 탄소원자 수에 따라서 α, β, γ-lactam을 효과적으로 합성할 수 있다(Fig. 1).

MIC-3500을 각 농도별(4, 8, 10, 15 그리고 20%)로 조제하여 마이크로웨이브 조사 후 각 농도별로 흡광도를 나타냈었다. 측정결과 193−203 nm에서 peak가 나타냈으며,절삭유의 농도가 짙어질수록 흡광도가 증가하였고 또한파장(nm)이 길어지는 것을 확인하였다(Fig. 1).노르말-헥산법으로 추출된 오일에 흡광도를 측정하였다. 그 결과 노르말-헥산법으로 추출된 오일의 양이 많을수록 흡광도가 증가함을 알 수 있었다(Fig. 2).Table 1. The characters of water-soluble cutting oilCutting oil MIC3500 (BUHMWOO CHEMICAL) METOSOL506 (HANSUNG) EM-100 (SINCOOL)Color (undiluted/diluent) Brown, (milky) Dark green (green milky) Brown transparent, (milk white)Specific gravity (15/4

Rotor wake causes unsteady aerodynamics of rotor blade. So, accurate prediction of wake is very important and vortex method is good solution for this problem. Aerodynamic force of the rotor blade is calculated by potential panel method and the rotor wake is simulated by vortex particle method. The vortex particle method is easier to treat wake-body interaction and has better performance to expect the effect of ground and fuselage interaction. Rotor in hovering and forward flight condition is simulated through these methods. Thrust and surface pressure of rotor are compared with experiment data.

This paper presents a study into pH Indicator-Embedded hydrogel micro-particles which are encoded various shapes according to the captured indicator. We incorporate various pH indicators into a photo-curable hydrogel, PEG-DA(Poly(ethylene glycol) diacrylate). Using the latest fluidic lithography techniques, we can easily fabricate variously patterned hydrogel particles based on in-situ photopolymerization of the PEG-DA in a micro-fluidic channel. The shape of the particle is related to the pH indicator inside the particle. We demonstrate that the micro pH sensors change their colors according to the pH levels. The micro pH sensors have various characteristics that are related to the curing time, particle size, etc. By changing these conditions, we can adjust the long term stability and reaction time of the hybrid micro pH sensors.

The handling ability of containers at the terminal strongly depends on the performance of the cargo handling system such as RTGC(Rubber Tired Gantry Crane). This paper introduces a new guide line position measurement method using a camera for the RTGC which plays a important role in the harbor area. Because the line tracking is the basic technique for control system design of RTGC, it is necessary to develop a useful and reliable measurement system. If the displacement and angle of the RTGC relative to a guide line as trajectory to follow is obtained, the position of RTGC is calculated. Therefore, in this paper, a camera-based measurement system is introduced. The proposed measurement system is robust against light fluctuation and cracks of the guideline. This system consists of a camera and a PC which are installed at the lower side of the RTGC. Two edges of the guide line are detected from an input image taken by the camera, and these positions are determined in a Hough parameter space by using the Hough transformation method. From the experimental results, high accurate standard deviations were found as 0.98 pixel of the displacement and 0.24 degree of the angle, including robustness against lighting fluctuation and cracks of the guide line also.

An open rotor is one of the next generation aero-engines as it has 30% higher efficiency compared to the conventional turbofan engines. However, a high level of noise loudness has been a major drawback of the open rotor for its commercial use in aviation market. Although there have been a number of efforts to reduce its noise level, an accurate prediction of unsteady and complex flow field of the open rotor makes it difficult for the design methodologies to be applied. This paper introduces one of the state-of-the-art design methodologies to handle the unsteady problem of low-noise open rotor design. A harmonic balance method which is an order of magnitude more efficient than the conventional timeaccurate CFD method is used to analyze open rotor flows. To demonstrate the accuracy of the harmonic balance method, a wind-tunnel experiment of the scaled model of the open rotor is carried out and aerodynamic performances are compared with the harmonic balance predictions. With the steady formulation of the flow governing equations through the harmonic balance method, a design method using a surrogate model is employed to find an optimum configuration that minimizes the noise level and total power at a constant thrust level. A noise prediction is computed using the Farassat formula, derived from the FfowcsWillimas Hawkings equation. Design variables of the blade radii, rotor spacing, and the pitch angle variation of the aft rotor are chosen. A parameter study to investigate the sensitivities of the design parameters to thrust and torque/power levels as well as to the noise loudness is carried out. A genetic algorithm to handle multi-objectives is used in combination with the surrogate model of Kriging response surface. An optimum configuration is obtained from the pareto front of the optimization results and shows the reduction of noise level by 7dB and power level by 4% from the baseline values.

In this paper, mathematical modeling of a small scale ducted-fan UAV is conducted, and the modeling results are compared with wind tunnel test. Wind tunnel test is performed and bunch of test data were acquired. A set of wind tunnel test data was categorized and approximated as mathematical functions. Mathematically modeled force and moments acting on the UAV are then compared with those of the wind tunnel data. A gradient-based algorithm is applied to extract trim states with respect to various flight conditions. Numerical analysis shows reasonable flight status with respect to airspeed.