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1.
J Clin Neurol ; 20(3): 265-275, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38330417

RESUMO

BACKGROUND AND PURPOSE: Early- and late-onset Alzheimer's disease (EOAD and LOAD, respectively) share the same neuropathological hallmarks of amyloid and neurofibrillary tangles but have distinct cognitive features. We compared structural brain connectivity between the EOAD and LOAD groups using structural network efficiency and evaluated the association of structural network efficiency with the cognitive profile and pathological markers of Alzheimer's disease (AD). METHODS: The structural brain connectivity networks of 80 AD patients (47 with EOAD and 33 with LOAD) and 57 healthy controls were reconstructed using diffusion-tensor imaging. Graph-theoretic indices were calculated and intergroup differences were evaluated. Correlations between network parameters and neuropsychological test results were analyzed. The correlations of the amyloid and tau burdens with network parameters were evaluated for the patients and controls. RESULTS: Compared with the age-matched control group, the EOAD patients had increased global path length and decreased global efficiency, averaged local efficiency, and averaged clustering coefficient. In contrast, no significant differences were found in the LOAD patients. Locally, the EOAD patients showed decreases in local efficiency and the clustering coefficient over a wide area compared with the control group, whereas LOAD patients showed such decreases only within a limited area. Changes in network parameters were significantly correlated with multiple cognitive domains in EOAD patients, but only with Clinical Dementia Rating Sum-of-Boxes scores in LOAD patients. Finally, the tau burden was correlated with changes in network parameters in AD signature areas in both patient groups, while there was no correlation with the amyloid burden. CONCLUSIONS: The impairment of structural network efficiency and its effects on cognition may differ between EOAD and LOAD.

2.
Anat Cell Biol ; 57(1): 13-17, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38351474

RESUMO

Masseter are commonly botulinum neurotoxin targeted muscle for facial contouring in aesthetic field. However, paradoxical masseteric bulging is common adverse effect that has not been discussed with ultrasonographic observations. Retrospective study has been conducted from October, 2021 to January, 2023, out of 324 patients have done blinded botulinum neurotoxin injection in the masseter at the middle and lower portion of the masseter with each side of 25 units (letibotulinum neurotoxin type A), 3 patients demonstrated paradoxical masseteric bulging has been reported and the image observed by ultrasonography by physician. Based on the observations made, we can infer that the function of the moving muscle involves twisting of the muscle fibers during contraction, along with the twisting of the deep inferior tendon, which causes the muscle to be divided into anterior and posterior compartments rather than into superficial and deep compartments of masseter. In ultrasonographic observe the skin surface of a patient with paradoxical masseteric bulging, it is observable that either the anterior or posterior part contracts significantly. The functional units of anterior and posterior compartment are observable as muscular contraction of inward movement of the muscle from either the anterior or posterior functional unit.

3.
J Cosmet Dermatol ; 23(2): 434-440, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37942679

RESUMO

OBJECTIVE: In the esthetic field, the masseter muscle is commonly targeted by botulinum neurotoxin for facial contouring. However, multiple botulinum neurotoxin injections have been reported to cause muscle fibrosis. Ultrasonography can be useful for clinical consideration in such cases. MATERIALS AND METHODS: This study presents nine cases of masseteric fibrosis caused by repeated botulinum neurotoxin injections with ultrasonographic analysis of full and partial masseteric fibrosis. RESULTS: Repetitive botulinum neurotoxin injections resulted in reduced masseter muscle volume, which frequently appeared hyperechoic on ultrasonography. The hyperechoic region was mostly located in the deep and posterior portions; however, in some cases, it was observed throughout the muscle, including the superficial, deep, or both areas. CONCLUSION: The fibrotic masseter muscles appear hyperechoic, and ultrasonography is necessary to analyze the degree and location of fibrosis. Predictions can be made for cases in which botulinum neurotoxin injections may have less of an effect after ultrasonography. Because muscle fibrosis can be localized, it is necessary to confirm the degree and location of fibrosis before determining the effective area of injection. In clinical practice, muscle fibrosis may be visible in a specific area where blind injections are administered.


Assuntos
Toxinas Botulínicas Tipo A , Fármacos Neuromusculares , Humanos , Toxinas Botulínicas Tipo A/uso terapêutico , Músculo Masseter/diagnóstico por imagem , Fármacos Neuromusculares/uso terapêutico , Neurotoxinas/uso terapêutico , Ultrassonografia , Injeções Intramusculares/efeitos adversos , Hipertrofia/tratamento farmacológico
4.
J Cosmet Dermatol ; 23(1): 84-89, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37381604

RESUMO

INTRODUCTION: Inadvertent entry of filler products into the supratrochlear, supraorbital, or dorsal nasal arteries, among other branches of the ophthalmic artery, might result in an immediate and devastating loss of vision. We wanted to examine how much filler could block the ophthalmic artery. MATERIALS AND METHODS: Twenty-nine fresh cadavers were examined. We exposed the arterial supply to the opthalmic artery by dissecting the orbital area. Thereafter, 17 filler injections were introduced into the supratrochlear, supraorbital, and dorsal nasal arteries each. The amount of filler injection that completely blocked the ophthalmic artery was measured. Additionally, one of the head specimens was processed using phosphotungstic acid-based contrast enhancement micro-computed tomography to analyze each arteries to obstruct its whole ophthalmic artery. RESULTS: The supratrochlear, supraorbital, and dorsal nasal arteries had mean volumes in milliliter (mean ± standard deviation) of 0.0397 ± 0.010 mL, 0.0409 ± 0.00932 mL, and 0.0368 ± 0.00732 mL, respectively. However, the arteries did not differ significantly. CONCLUSION: Even a modest amount of filler injection can completely block the ophthalmic artery, resulting in visual loss.


Assuntos
Técnicas Cosméticas , Preenchedores Dérmicos , Humanos , Preenchedores Dérmicos/efeitos adversos , Técnicas Cosméticas/efeitos adversos , Microtomografia por Raio-X , Artéria Oftálmica , Cegueira
5.
Skin Res Technol ; 29(12): e13535, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38093502

RESUMO

BACKGROUND: Thread lifting is a common minimally invasive plastic surgery procedure. Parotid gland injury caused by thread lifting is a known complication; however, visual evidence of this complication is lacking. OBJECTIVES: This study aimed to present cases of parotid gland injury by thread lifting shown using ultrasound and to discuss the importance of ultrasound detection of the location of the parotid gland before thread insertion. METHODS: This study included eight patients diagnosed with parotid gland perforation and one with parotid duct injury due to threads from November 2020 to October 2022. RESULTS: Six patients showed tenderness and swelling, three were asymptomatic, and one with duct injury showed severe swelling and pain. Although the severity and duration of symptoms have differed, we confirmed the progress of improvement with conservative treatment and confirmed ultrasound findings progressed. CONCLUSIONS: Using ultrasound to detect the parotid gland's location before thread lifting might reduce the chance of parotid duct injury. Identifying immediate parotid duct or gland injury with ultrasound can help to act quickly for delayed pain or swelling and reduce the likelihood of additional complications.


Assuntos
Glândula Parótida , Ductos Salivares , Humanos , Glândula Parótida/diagnóstico por imagem , Glândula Parótida/cirurgia , Ductos Salivares/diagnóstico por imagem , Ductos Salivares/cirurgia , Ultrassonografia , Dor , Ultrassonografia de Intervenção
6.
Sensors (Basel) ; 23(21)2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37960648

RESUMO

We configured a long-distance ranging apparatus to test the principle of dual-comb time-of-flight measurement using ultrashort lasers. Emphasis was given to the evaluation of open-air performance quantitatively in terms of the measurement resolution and stability. The test results revealed that our dual-comb asynchronous optical pulse sampling permits micrometer-resolved ranging with a repeatability of 2.05 µm over a 648 m distance in dry weather conditions. Further atmospheric effects were evaluated in three different weather conditions with corresponding Allan deviations. Finally, the capability of simultaneous determination of multiple targets was verified with the potential of advanced industrial applications, such as manufacturing, surveying, metrology, and geodesy.

7.
J Alzheimers Dis ; 94(3): 1233-1246, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37393505

RESUMO

BACKGROUND: Little is known regarding the differential effects of the apolipoprotein E (APOE) ɛ4 on the regional topography of amyloid and tau in patients with both early-onset (EOAD) and late-onset Alzheimer's disease (LOAD). OBJECTIVE: To compare the distribution and association of tau, amyloid, and cortical thickness among groups classified by the presence of APOEɛ4 allele and onset age. METHODS: A total of 165 participants including 54 EOAD patients (29 ɛ4-; 25 ɛ4+), 45 LOAD patients (21 ɛ4-; 24 ɛ4+), and 66 age-matched controls underwent 3T MRI, 18F-THK5351 (THK) and 18F-flutemetamol (FLUTE) PET scans, APOE genotyping, and neuropsychological tests. Data for voxel-wise and standardized uptake values from PET scans were analyzed in the context of APOE and age at onset. RESULTS: EOAD ɛ4- patients showed greater THK retention in the association cortices, whereas their EOAD ɛ4+ counterparts had more retention in medial temporal areas. THK topography of LOAD ɛ4+ was similar to EOAD ɛ4 + . THK correlated positively with FLUTE and conversely with mean cortical thickness, being lowest in EOAD ɛ4-, highest in LOAD ɛ4-, and modest in ɛ4+ groups. Even in the APOEɛ4+ groups, THK tended to correlate with FLUTE and mean cortical thickness in the inferior parietal region in EOAD and in the medial temporal region in LOAD. LOAD ɛ4- manifested with prevalent small vessel disease markers and the lowest correlation between THK retention and cognition. CONCLUSION: Our observations suggest the differential effects of the APOEɛ4 on the relationship between tau and amyloid in EOAD and LOAD.


Assuntos
Doença de Alzheimer , Humanos , Alelos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Peptídeos beta-Amiloides , Apolipoproteína E4/genética , Apolipoproteínas E/genética , Cognição , Tomografia por Emissão de Pósitrons
8.
J Magn Reson Imaging ; 58(1): 272-283, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36285604

RESUMO

BACKGROUND: Cerebral microbleeds (CMBs) are microscopic brain hemorrhages with implications for various diseases. Automated detection of CMBs is a challenging task due to their wide distribution throughout the brain, small size, and visual similarity to their mimics. For this reason, most of the previously proposed methods have been accomplished through two distinct stages, which may lead to difficulties in integrating them into clinical workflows. PURPOSE: To develop a clinically feasible end-to-end CMBs detection network with a single-stage structure utilizing 3D information. This study proposes triplanar ensemble detection network (TPE-Det), ensembling 2D convolutional neural networks (CNNs) based detection networks on axial, sagittal, and coronal planes. STUDY TYPE: Retrospective. SUBJECTS: Two datasets (DS1 and DS2) were used: 1) 116 patients with 367 CMBs and 12 patients without CMBs for training, validation, and testing (70.39 ± 9.30 years, 68 women, 60 men, DS1); 2) 58 subjects with 148 microbleeds and 21 subjects without CMBs only for testing (76.13 ± 7.89 years, 47 women, 32 men, DS2). FIELD STRENGTH/SEQUENCE: A 3 T field strength and 3D GRE sequence scan for SWI reconstructions. ASSESSMENT: The sensitivity, FPavg (false-positive per subject), and precision measures were computed and analyzed with statistical analysis. STATISTICAL TESTS: A paired t-test was performed to investigate the improvement of detection performance by the suggested ensembling technique in this study. A P value < 0.05 was considered significant. RESULTS: The proposed TPE-Det detected CMBs on the DS1 testing set with a sensitivity of 96.05% and an FPavg of 0.88, presenting statistically significant improvement. Even when the testing on DS2 was performed without retraining, the proposed model provided a sensitivity of 85.03% and an FPavg of 0.55. The precision was significantly higher than the other models. DATA CONCLUSION: The ensembling of multidimensional networks significantly improves precision, suggesting that this new approach could increase the benefits of detecting lesions in the clinic. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.


Assuntos
Hemorragia Cerebral , Imageamento por Ressonância Magnética , Masculino , Humanos , Feminino , Imageamento por Ressonância Magnética/métodos , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/patologia , Estudos Retrospectivos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Redes Neurais de Computação
9.
Artigo em Inglês | MEDLINE | ID: mdl-35627599

RESUMO

Many people visited urban parks during the COVID-19 pandemic to reduce the negative effects of lack of physical activity, social isolation, anxiety, and depression. It is unclear whether all parks are robust against the pandemic, helping people sustain healthy daily living through the diverse activities within them. Nevertheless, few studies have identified the specific relationship between park visits and the COVID-19 pandemic. Therefore, this study aims to demonstrate how physical features such as type, functionality, and access influenced daily visiting to parks during the pandemic, using mobile phone data at a micro level. This study first classified urban parks as point-type parks with an area of less than 1 ha, plane-type parks with 1 ha or more, and line-type parks with elongated shapes, while measuring accessibility to residential, employment, transportation, and auxiliary facilities within the park. The study employed the multi-level regression model with random intercept to investigate the effects of differing park visits, focusing on Goyang city, South Korea. Our analysis results identified that easy access from home was more important than the park size during the pandemic. If we look at the types of parks, the use of both plane- and point-type parks increased more than that of line-type parks. However, line-type parks near homes, along with shopping and sports facilities, were found to be more robust to the pandemic. These findings can be informative to provide specific guidelines to fulfill the enhanced role of parks in sustaining public health during an infectious disease pandemic that may strike again.


Assuntos
COVID-19 , Parques Recreativos , COVID-19/epidemiologia , Humanos , Pandemias , Logradouros Públicos , Recreação
10.
Front Aging Neurosci ; 13: 694629, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34248609

RESUMO

BACKGROUND: Despite emerging evidence suggesting that visceral fat may play a major role in obesity-induced neurodegeneration, little evidence exists on the association between visceral fat and brain cortical thickness in the elderly. PURPOSE: We aimed to examine the association between abdominal fat and brain cortical thickness in a Korean elderly population. METHODS: This cross-sectional study included elderly individuals without dementia (n = 316). Areas of visceral fat and subcutaneous fat (cm2) were estimated from computed tomography scans. Regional cortical thicknesses (mm) were obtained by analyzing brain magnetic resonance images. Given the inverted U-shaped relationship between visceral fat area and global cortical thickness (examined using a generalized additive model), visceral fat area was categorized into quintiles, with the middle quintile being the reference group. A generalized linear model was built to explore brain regions associated with visceral fat. The same approach was used for subcutaneous fat. RESULTS: The mean (standard deviation) age was 67.6 (5.0) years. The highest quintile (vs. the middle quintile) group of visceral fat area had reduced cortical thicknesses in the global [ß = -0.04 mm, standard error (SE) = 0.02 mm, p = 0.004], parietal (ß = -0.04 mm, SE = 0.02 mm, p = 0.01), temporal (ß = -0.05 mm, SE = 0.02 mm, p = 0.002), cingulate (ß = -0.06 mm, SE = 0.02 mm, p = 0.01), and insula lobes (ß = -0.06 mm, SE = 0.03 mm, p = 0.02). None of the regional cortical thicknesses significantly differed between the highest and the middle quintile groups of subcutaneous fat area. CONCLUSION: The findings suggest that a high level of visceral fat, but not subcutaneous fat, is associated with a reduced cortical thickness in the elderly.

11.
J Nanosci Nanotechnol ; 21(8): 4524-4531, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33714356

RESUMO

As an eco-friendly alternative fuel material, ammonium dinitramide (ADN, NH4N(NO2)2) is safe and stable at room temperature; however, it requires high purity for practical applications. A small amount of impurities can retard the catalytic decomposition of the monopropellant in the thruster, lower the specific impulse, and induce side effects such as clogging of the nozzle. Therefore, we purified NH4N(NO2)2 by performing repeated extractions, adsorption by powdered activated carbon, and low-temperature extractions. In this study, we evaluated the chemical density of purified NH4N(NO2)2 through Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, and ion chromatography, and obtained a final purity of 99.8%. Furthermore, we fabricated a liquid fuel using high-purity NH4N(NO2)2 as the main oxidizing agent, and can be prepared a mono-propellant formulation that exhibited decomposition at a minimum temperature of 148 °C.

12.
Sensors (Basel) ; 20(24)2020 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-33353042

RESUMO

Multilateration tracking systems (MLTSs) are used in industrial three-dimensional (3D) coordinate measuring applications. For high-precision measurement, system parameters must be calibrated properly in advance. For an MLTS using absolute distance measurement (ADM), the conventional self-calibration method significantly reduces estimation efficiency because all system parameters are estimated simultaneously using a complicated residual function. This paper presents a novel self-calibration method that optimizes ADM to reduce the number of system parameters via highly precise and separate estimations of dead paths. Therefore, the residual function to estimate the tracking station locations can be simplified. By applying a suitable mathematical procedure and solving the initial guess problem without the aid of an external device, estimation accuracy of the system parameters is significantly improved. In three self-calibration experiments, with ADM repeatability of approximately 3.4 µm, the maximum deviation of the system parameters estimated by the proposed self-calibration method was 68.6 µm, while the maximum deviation estimated by the conventional self-calibration method was 711.9 µm. Validation of 3D coordinate measurements in a 1000 mm × 1000 mm × 1000 mm volume showed good agreement between the proposed ADM-based MLTS and a commercial laser tracker, where the maximum difference based on the standard deviation was 17.7 µm. Conversely, the maximum difference was 98.8 µm using the conventional self-calibration method. These results confirmed the efficiency and feasibility of the proposed self-calibration method.

13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1055-1058, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018167

RESUMO

Cerebral Microbleeds (CMBs) are small chronic brain hemorrhages, which have been considered as diagnostic indicators for different cerebrovascular diseases including stroke, dysfunction, dementia, and cognitive impairment. In this paper, we propose a fully automated two-stage integrated deep learning approach for efficient CMBs detection, which combines a regional-based You Only Look Once (YOLO) stage for potential CMBs candidate detection and three-dimensional convolutional neural networks (3D-CNN) stage for false positives reduction. Both stages are conducted using the 3D contextual information of microbleeds from the MR susceptibility-weighted imaging (SWI) and phase images. However, we average the adjacent slices of SWI and complement the phase images independently and utilize them as a two- channel input for the regional-based YOLO method. The results in the first stage show that the proposed regional-based YOLO efficiently detected the CMBs with an overall sensitivity of 93.62% and an average number of false positives per subject (FPavg) of 52.18 throughout the five-folds cross-validation. The 3D-CNN based second stage further improved the detection performance by reducing the FPavg to 1.42. The outcomes of this work might provide useful guidelines towards applying deep learning algorithms for automatic CMBs detection.


Assuntos
Imageamento por Ressonância Magnética , Redes Neurais de Computação , Algoritmos , Encéfalo , Hemorragia Cerebral/diagnóstico , Humanos
14.
J Opt Soc Am A Opt Image Sci Vis ; 37(9): B27-B35, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32902417

RESUMO

Ultrashort pulse lasers are emerging as an advanced tool of distance measurement, with their unique temporal and spectral characteristics being extended to diverse principles of absolute ranging and instrumentation. Here, a systematic methodology is presented for absolute ranging by means of the time-of-flight measurement of ultrashort light pulses using dual-comb asynchronous optical sampling. Based on an elaborate uncertainty analysis, influencing system parameters such as the pulse duration, repetition rate, and averaging time are optimized to achieve a sub-µm measurement accuracy. The absolute ranging system developed in this study demonstrates a combined standard uncertainty of 0.986 µm for a 0.5 ms averaging over a distance range of 3.0 m, with a further reduction to 0.056 µm when the averaging time is increased to 0.5 s. The outstanding performance leads to unprecedented multitarget applications: machine feed control with thermal error compensation in real time as well as the nondestructive inspection of multilens assembly in a production line.

15.
J Nanosci Nanotechnol ; 20(11): 6855-6861, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32604527

RESUMO

Dinitramide anion [-N(NO2)2] salt composed of resonance structure is a plausible oxidizing agents, as efficient propellant. Among them, guanidinium dinitramide (GDN) is an organic compound improving the stability against moisture, as well long term storage. An additional advantage composed guanidinium ion is the reaction efficient via the decomposed by-product during pyrognostics, maximum yield of 99%. The types of GDN (GDN-I, II, III, IV, V) were synthesized using several starting material such as guanidine acetate, chloride, carbonate, nitrate and sulfate under hydrodeprivation. In this work, the intermediates formed in these processes were closely identified and their thermal properties, and chemical structure were examined. The absorption peaks by Fourier transform infrared (FT-IR) were found guanidinium infrared frequencies (3452, 3402, 3354, 3278, 1642 cm-1) and dinitramide infrared frequencies (3208, 1570, 1492, 1416, 1337, 1179, 1000 cm-1). The activation energy of GDN samples were obtained Ea = 53.26 Kcal/mole (GDN-I), 50.94 Kcal/mole (GDN-II), 52.34 Kcal/mole (GDN-III), 62.19 Kcal/mole (GDN-IV), 55.32 Kcal/mole (GDN-V) from exothermic at over 153°C.

16.
Front Aging Neurosci ; 12: 615467, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33584247

RESUMO

Background: Mild cognitive impairment (MCI) is a condition with diverse causes and clinical outcomes that can be categorized into subtypes. [18F]THK5351 has been known to detect reactive astrogliosis as well as tau which is accompanied by neurodegenerative changes. Here, we identified heterogeneous groups of MCI patients using THK retention patterns and a graph theory approach, allowing for the comparison of risk of progression to dementia in these MCI subgroups. Methods: Ninety-seven participants including 60 MCI patients and individuals with normal cognition (NC, n = 37) were included and undertook 3T MRI, [18F]THK5351 PET, and detailed neuropsychological tests. [18F]Flutemetamol PET was also performed in 62 participants. We calculated similarities between MCI patients using their regional standardized uptake value ratio of THK retention in 75 ROIs, and clustered subjects with similar retention patterns using the Louvain method based on the modularity of the graph. The clusters of patients identified were compared with an age-matched control group using a general linear model. Dementia conversion was evaluated after a median follow-up duration of 34.6 months. Results: MCI patients were categorized into four groups according to their THK retention patterns: (1) limbic type; (2) diffuse type; (3) sparse type; and (4) AD type (retention pattern as in AD). Subjects of the limbic type were characterized by older age, small hippocampal volumes, and reduced verbal memory and frontal/executive functions. Patients of the diffuse type had relatively large vascular burden, reduced memory capacity and some frontal/executive functions. Co-morbidity and mortality were more frequent in this subgroup. Subjects of the sparse type were younger and declined only in terms of visual memory and attention. No individuals in this subgroup converted to dementia. Patients in the AD type group exhibited the poorest cognitive function. They also had the smallest hippocampal volumes and the highest risk of progression to dementia (90.9%). Conclusion: Using cluster analyses with [18F]THK5351 retention patterns, it is possible to identify clinically-distinct subgroups of MCI patients and those at greater risk of progression to dementia.

17.
Neuroimage Clin ; 28: 102464, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33395960

RESUMO

Cerebral Microbleeds (CMBs) are small chronic brain hemorrhages, which have been considered as diagnostic indicators for different cerebrovascular diseases including stroke, dysfunction, dementia, and cognitive impairment. However, automated detection and identification of CMBs in Magnetic Resonance (MR) images is a very challenging task due to their wide distribution throughout the brain, small sizes, and the high degree of visual similarity between CMBs and CMB mimics such as calcifications, irons, and veins. In this paper, we propose a fully automated two-stage integrated deep learning approach for efficient CMBs detection, which combines a regional-based You Only Look Once (YOLO) stage for potential CMBs candidate detection and three-dimensional convolutional neural networks (3D-CNN) stage for false positives reduction. Both stages are conducted using the 3D contextual information of microbleeds from the MR susceptibility-weighted imaging (SWI) and phase images. However, we average the adjacent slices of SWI and complement the phase images independently and utilize them as a two-channel input for the regional-based YOLO method. This enables YOLO to learn more reliable and representative hierarchal features and hence achieve better detection performance. The proposed work was independently trained and evaluated using high and low in-plane resolution data, which contained 72 subjects with 188 CMBs and 107 subjects with 572 CMBs, respectively. The results in the first stage show that the proposed regional-based YOLO efficiently detected the CMBs with an overall sensitivity of 93.62% and 78.85% and an average number of false positives per subject (FPavg) of 52.18 and 155.50 throughout the five-folds cross-validation for both the high and low in-plane resolution data, respectively. These findings outperformed results by previously utilized techniques such as 3D fast radial symmetry transform, producing fewer FPavg and lower computational cost. The 3D-CNN based second stage further improved the detection performance by reducing the FPavg to 1.42 and 1.89 for the high and low in-plane resolution data, respectively. The outcomes of this work might provide useful guidelines towards applying deep learning algorithms for automatic CMBs detection.


Assuntos
Aprendizado Profundo , Interpretação de Imagem Assistida por Computador , Algoritmos , Hemorragia Cerebral/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética
18.
J Nanosci Nanotechnol ; 19(12): 7906-7910, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31196307

RESUMO

The aim of this study is to elucidate the influence of an iridium loading strategy over hexaaluminate on the catalytic performance during the decomposition of liquid monopropellants based on ammonium dinitramide (ADN). Powder-type and pellet-type Ir/hexaaluminate catalysts were prepared and their chemico-physical properties were characterized by N2 adsorption, XRD, XRF, and SEM. There were considerable differences in the Ir amounts present on the surface according to the impregnation method employed. The catalytic activities of three types of Ir/hexaaluminate catalysts to decompose the ADN-based liquid monopropellant were compared using a semi-batch type of reactor. Pellet-type Ir/hexaaluminate catalyst, which formed hexaaluminate into a pellet and where iridium was impregnated during the last stage, showed the lowest onset temperature during the decomposition of the ADN-based liquid monopropellant, having the effect of lowering the decomposition onset temperature by around 60 °C compared to that without a catalyst. This was due to the pellet-type Ir/hexaaluminate having a larger surface area and a large number of Ir active sites on its surface.

19.
J Cosmet Dermatol ; 17(4): 637-642, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30058278

RESUMO

BACKGROUND: Injections of filler into the nose for dorsum augmentation have a higher risk of complications due to the complicated blood supply and anastomotic channels in this area. OBJECTIVES: The aim of this study was to determine the anatomical features and location of the dorsal nasal artery (DNA), and to provide clinical anatomical information to reduce side effects and severe complications in the perinasal area. METHODS: Using the 31 cadaveric noses in Asians, dissections and histologic examinations were performed to identify the location and depth of the vascular structures including DNA. RESULTS: Dorsal nasal artery ran downward at 20.3 ± 3.5 mm from the intercanthal line and the communicating branch that connected the bilateral DNAs was located 8.5 ± 3.5 mm inferior to the intercanthal line. The DNA was located at 4.4 ± 3.2 mm, 4.6 ± 4.4 mm, and 5.2 ± 4.4 mm lateral to the midline of the nose on the intercanthal, quadrisected, and bisected lines, respectively. At the level of nasal bone, DNA was located superficial to the muscular layer and it runs inferolaterally on dorsum on nose. It was running more deeply and located beneath the fibromuscular layer at the cartilaginous portion of the dorsum of nose. CONCLUSIONS: Injection into deep fatty layer may reduce the risk of arterial injury and the consequent complications. However, in a hooked nose, the tip of the needle traveling along the deep layer approaches the superficial layer due to the convexity of the hump as it passes over it, which can increase the probability of damaging the DNA.


Assuntos
Artérias/anatomia & histologia , Nariz/irrigação sanguínea , Adulto , Idoso , Idoso de 80 Anos ou mais , Pontos de Referência Anatômicos , Cadáver , Preenchedores Dérmicos/efeitos adversos , Dissecação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ritidoplastia/efeitos adversos
20.
J Nanosci Nanotechnol ; 18(1): 353-358, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29768853

RESUMO

Ordered mesoporous Cu-Mn binary metal oxide (meso-CuMnOx) catalysts were successfully synthesized by a hard-templating method from a mesoporous silica template with a cubic Ia3d mesostructure (KIT-6) or hydrophobic KIT-6, exhibiting a well-developed crystalline framework, a regular pore size distribution and a high surface area. The copper and manganese elements in the mesoporous Cu-Mn binary metal oxides (meso-CuMnOx-N and meso-CuMnOx-HP), obtained from the KIT-6 and hydrophobic KIT-6, respectively, were homogeneously dispersed in the whole particles. The activities of meso-CuMnOx catalysts for the decomposition of a liquid monopropellant containing an energetic ionic liquid, ammonium dinitramide, were much higher than that over a CuMnOx catalyst prepared by a conventional precipitation method. This is attributed to the well-developed mesoporosity of the meso-CuMnOx catalysts. Among the mesoporous CuMnOx catalysts, the decomposition onset temperature over meso-CuMnOx-HP (87.9 °C) was found to be lower than that over meso-CuMnOx-N (100.4 °C), probably due to its higher mesoporosity and surface area.

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