117 results on '"Yuna Choi"'
Search Results
2. Parameter estimation-based discrimination method for osteoporosis stage with ultrasound bone densitometer
- Author
-
Yuna Choi, Jaehyun Kim, Gwangyeol Cha, Youngjin Choi, Il Youn Jung, Bong Gun Lee, and Chang-Hun Lee
- Subjects
Medicine ,Science - Abstract
Abstract This paper proposes a new method for predicting the stage of osteoporosis by estimating bone-density parameters using an ultrasonic-bone densitometer. Using the developed ultrasonic bone densitometer, the ultrasonic signal passing through the phalanx of the finger was measured, and the measured signal was preprocessed to generate input data for parameter estimation. The Nakagami probability-density function was used for modeling this data, and optimal bone-density parameters were estimated using an optimization problem – to predict the stage of osteoporosis. The proposed method was verified through in vitro and in vivo experiments. In phantom experiments, cubes with different materials (ABS plastic, PLA plastic, Nylon) were used, and each cube had a different density through internal density so that it could mimic bones. The experiments were conducted using them and the results were compared. The experimental results confirmed that there was a correlation between the density and estimated parameters for all three materials. In the in vivo experiment, the osteoporosis stages were classified as normal, osteopenia, and osteoporosis, and the bone-density parameters were estimated for the participants of each group. Thus, a basis for predicting the stage of osteoporosis was created, and data from new participants were collected and verified as test data. As a result, normal and abnormal groups (osteopenia and osteoporosis) were predicted.
- Published
- 2024
- Full Text
- View/download PDF
3. Asymptomatic Common Carotid Artery Occlusion and Occipital-Vertebral Artery Anastomosis: A Case Report and Literature Review
- Author
-
Yuna Choi, Jun Soo Byun, Hyun Seok Choi, Jin Kyo Choi, and Sunghoon Kim,
- Subjects
common carotid artery occlusion ,collaterals ,occipital artery ,vertebral artery ,case report ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Common carotid artery occlusion (CCAO) is a very rare disorder that has rarely been studied. CCAO causes several neurological symptoms but can sometimes be asymptomatic due to the development of various anastomoses. Herein, we report the case of a 70-year-old male patient diagnosed with asymptomatic CCAO due to anastomotic flow. The patient underwent transfemoral cerebral angiography (TFCA) and was found to have CCAO with two collateral pathways, including an occipital arteryvertebral artery anastomosis. We emphasize the importance of TFCA when CCAO is suspected and review the types and anastomotic pathways of CCAO.
- Published
- 2023
- Full Text
- View/download PDF
4. Pneumocephalus and headache following craniotomy during the immediate postoperative period
- Author
-
Tae Kwan Kim, Jun Rho Yoon, Yee Suk Kim, Yuna Choi, Seheui Han, Jaeuk Jung, and Ik Seong Park
- Subjects
Pneumocephalus ,Craniotomy ,Headache ,Surgery ,RD1-811 - Abstract
Abstract Background Pneumocephalus may be responsible for post-craniotomy headache but is easily overlooked in the clinical situation. In the present study, the relationship between the amount of intracranial air and post-craniotomy headache was investigated. Methods A retrospective observational study was performed on 79 patients who underwent minimal invasive craniotomy for unruptured cerebral aneurysms. Those who had undergone previous neurosurgery, neurological deficit before and after surgery were excluded The amount of air in the cranial cavity was measured using brain computed tomography (CT) taken within 6 h after surgery. To measure the degree of pain due to intracranial air, daily and total analgesic administration amount were used as a pain index. Correlation between intracranial air volume and total consumption of analgesic during hospitalization was tested using Spearman rank correlation coefficients. Receiver operating characteristics (ROC) analysis was used to determine the amount of air associated with increased analgesic consumption over 72 h postoperatively. Results The mean amount of intracranial air was 15.6 ± 9.1 mL. Total administration of parenteral and oral analgesics frequency were 6.5 ± 4.5, 13.2 ± 7.9 respectively. A statically significant correlation was observed between daily and total parenteral analgesic consumption after surgery and the amount of intracranial air at followed-up brain CT postoperatively within 24 h (r = 0.69, p
- Published
- 2022
- Full Text
- View/download PDF
5. Osteopontin is a biomarker for early autoimmune uveoretinitis
- Author
-
Jeongtae Kim, Meejung Ahn, Yuna Choi, Jiyoon Chun, Kyungsook Jung, Akane Tanaka, Hiroshi Matsuda, and Taekyun Shin
- Subjects
cd44 ,ciliary body ,experimental autoimmune uveoretinitis ,macrophage ,müller cell ,osteopontin ,photoreceptor cell ,retina ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Osteopontin (OPN) is an extracellular matrix protein with a diverse range of functions, including roles in cell adhesion, migration, and immunomodulation, which are associated with the modulation of neuroinflammation in the central nervous system. The present study was performed to evaluate the involvement of OPN in the eyes of an experimental autoimmune uveoretinitis (EAU) model. The EAU model was developed by immunization of Lewis rats with interphotoreceptor retinoid-binding protein. The results showed the OPN level was remarkably upregulated in the eye of EAU rats on day 9 post-immunization. The level of CD44, a ligand of OPN, was increased in the ciliary body of EAU rats. Furthermore, OPN was also detected in the ciliary body and activated microglia/macrophages in the EAU retina. The results suggest that OPN was significantly upregulated in the eyes of EAU rats, and that it may be useful as an early biomarker of ocular autoimmune diseases. All animal experiments were approved by the Institutional Animal Care and Use Committee of Jeju National University (approval No. 2020-0012) on March 11, 2020.
- Published
- 2022
- Full Text
- View/download PDF
6. Effects of the July 2018 worldwide valsartan recall and shortage on global trends in antihypertensive medication use: a time-series analysis in 83 countries
- Author
-
Jared W Magnani, Mina Tadrous, Katie J Suda, Yuna Choi, Araniy Santhireswaran, Cherry Chu, and Inma Hernandez
- Subjects
Medicine - Abstract
Objectives This study aims to examine the effects of the July 2018 worldwide valsartan recall and shortage on global trends of antihypertensive medication use in 83 countries.Methods A time-series analysis of monthly purchases of valsartan, other angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACEIs) across 83 countries from January 2017 to July 2020 was conducted using the IQVIA MIDAS database. Trends in outcomes were investigated globally and by economic level (developed vs developing economies). The valsartan recall’s impact on antihypertensive use was assessed with interventional autoregressive integrated moving average modelling.Results Global valsartan utilisation trends decreased significantly by 15.7% (−61 166 515 SU; p
- Published
- 2023
- Full Text
- View/download PDF
7. Case report: Bilateral globus pallidus lesions and delayed progressive leukoencephalopathy in COVID-19: Effects of hypoxia alone or combination of hypoxia and inflammation?
- Author
-
Ahmad A. Ballout, Michael Kolesnik, Yuna Choi, Marc S. Ayoub, Asaff Harel, and Souhel Najjar
- Subjects
COVID-19 ,leukoencephalopathy ,globus pallidus ,SARS-CoV-2 ,hypoxia ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
BackgroundThe globus pallidus is a highly mitochondria-rich metabolic structure that is particularly sensitive to metabolic disturbances and hypoxia. Symmetric lesions of globus pallidus and delayed diffuse leukoencephalopathy were documented in toxic–metabolic disorders, hypoxia, a neurodegenerative disorder, and mitochondrial encephalopathies. Similar changes are also reported in individuals with active COVID-19 infections with associated hypoxia or critical illness.Case informationWe describe a patient with post–COVID-19 infection who presented with rapid cognitive and neurological decline associated with similar neuroimaging structural changes but without toxic–metabolic changes or hypoxia. Despite multiple non-inflammatory cerebrospinal fluid studies, mechanisms involving post–COVID-19 inflammation and immune dysregulation are suspected, given the unexplained continued decline in the neurological status, lack of concurrent hypoxia or antecedent respiratory difficulties, and after a reasonable exclusion of alternative etiologies. Hypermetabolism of both anteromedial temporal structures and diffuse hypometabolism predominantly in the frontal region on PET scan provided indirect support for possible inflammatory mechanisms after reasonable exclusion of alternative etiologies, such as direct CNS infection, among others. The patient's neurological impairment improved substantially after treatment with pulse steroids, plasmapheresis, and rituximab.ConclusionTo the best of our knowledge, this is the first report of post–COVID-19 with bilateral symmetric contrast-enhancing necrotic lesions of globus pallidus with delayed diffuse supratentorial leukoencephalopathy with microhemorrhages without concurrent hypoxia or reported preceding symptoms suggestive of hypoxia. We suspect that these inflammatory mechanisms might be triggered by prior COVID-19 exposure/infection. Furthermore, the role of the cross-talk between inflammation and clinically mild or silent hypoxia linked to prior COVID-19 infection cannot be excluded. Awareness of these post–COVID-19 neurological sequelae and their potential pathophysiology among those with no known antecedent significant hypoxia are important for early recognition and treatment.
- Published
- 2023
- Full Text
- View/download PDF
8. Feasibility study of portable multi-energy computed tomography with photon-counting detector for preclinical and clinical applications
- Author
-
Chang-Lae Lee, Key Jo Hong, Namwoo Kim, Kwanhee Han, Dongkyu Kim, Hoe-Su Jung, Sangmin Lee, Junyoung Park, Kyoung-Yong Lee, Jee Eun Lee, Yuna Choi, and Minkook Cho
- Subjects
Medicine ,Science - Abstract
Abstract In this study, preclinical experiments were performed with an in-house developed prototypal photon-counting detector computed tomography (PCD CT) system. The performance of the system was compared with the conventional energy-integrating detector (EID)-based CT, concerning the basic image quality biomarkers and the respective capacities for material separation. The pre- and the post-contrast axial images of a canine brain captured by the PCD CT and EID CT systems were found to be visually similar. Multi-energy images were acquired using the PCD CT system, and machine learning-based material decomposition was performed to segment the white and gray matters for the first time in soft tissue segmentation. Furthermore, to accommodate clinical applications that require high resolution acquisitions, a small, native, high-resolution (HR) detector was implemented on the PCD CT system, and its performance was evaluated based on animal experiments. The HR acquisition mode improved the spatial resolution and delineation of the fine structures in the canine’s nasal turbinates compared to the standard mode. Clinical applications that rely on high-spatial resolution expectedly will also benefit from this resolution-enhancing function. The results demonstrate the potential impact on the brain tissue segmentation, improved detection of the liver tumors, and capacity to reconstruct high-resolution images both preclinically and clinically.
- Published
- 2021
- Full Text
- View/download PDF
9. Design framework for a seamless smart glove using a digital knitting system
- Author
-
Yewon Son, Seulah Lee, Yuna Choi, Sora Han, Hyuna Won, Tae-Hyun Sung, Youngjin Choi, and Jihyun Bae
- Subjects
Framework for wearable electronics ,Seamless glove sensor ,Digital knitting CAD/CAM system ,Finger motion detection ,Textile bleaching, dyeing, printing, etc. ,TP890-933 ,Social Sciences - Abstract
Abstract The wearable electronics integrated with textile-based devices is a promising strategy to meet the requirements of human comfort as well as electrical performances. This research presents a design and development framework for a seamless glove sensor system using digital knitting fabrication. Based on the performance requirements of glove sensors for controlling a prosthetic hand, desirable design components include electrical conductivity, comfort, formfit, electrical sensitivity, and customizable design. These attributes are determined and achieved by applying appropriate materials and fabrication technologies. In this study, a digital knitting CAD/CAM system is utilized to meet the desired performance criteria, and two prototypes of the seamless glove sensor systems are successfully developed for the detection of both human and robotic finger motions. This digital knitting system will provide considerable potential for customized design development as well as a sustainable production process. This structured, systematic approach could be adapted in the future development of wearable electronic textile systems.
- Published
- 2021
- Full Text
- View/download PDF
10. Ninjurin-1: a biomarker for reflecting the process of neuroinflammation after spinal cord injury
- Author
-
Poornima D E. Weerasinghe-Mudiyanselage, Jeongtae Kim, Yuna Choi, Changjong Moon, Taekyun Shin, and Meejung Ahn
- Subjects
astrocytes ,clip compression injury ,macrophage ,microglia ,neuroinflammation ,ninjurin-1 ,rat ,spinal cord ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Previous studies have shown that Ninjurin-1 participates in cell trafficking and axonal growth following central and peripheral nervous system neuroinflammation. But its precise roles in these processes and involvement in spinal cord injury pathophysiology remain unclear. Western blot assay revealed that Ninjurin-1 levels in rats with spinal cord injury exhibited an upregulation until day 4 post-injury and slightly decreased thereafter compared with sham controls. Immunohistochemistry analysis revealed that Ninjurin-1 immunoreactivity in rats with spinal cord injury sharply increased on days 1 and 4 post-injury and slightly decreased on days 7 and 21 post-injury compared with sham controls. Ninjurin-1 immunostaining was weak in vascular endothelial cells, ependymal cells, and some glial cells in sham controls while it was relatively strong in macrophages, microglia, and reactive astrocytes. These findings suggest that a variety of cells, including vascular endothelial cells, macrophages, and microglia, secrete Ninjurin-1 and they participate in the pathophysiology of compression-induced spinal cord injury. All experimental procedures were approved by the Care and Use of Laboratory Animals of Jeju National University (approval No. 2018-0029) on July 6, 2018.
- Published
- 2021
- Full Text
- View/download PDF
11. Inner structure- and surface-controlled hollow MnO nanocubes for high sensitive MR imaging contrast effect
- Author
-
Aastha Kukreja, Byunghoon Kang, Seungmin Han, Moo-Kwang Shin, Hye Young Son, Yuna Choi, Eun-Kyung Lim, Yong-Min Huh, and Seungjoo Haam
- Subjects
Hollow nanostructure ,Ligand encapsulation and exchange ,Manganese oxide nanocube ,MR imaging ,T1 contrast agent ,Technology ,Chemical technology ,TP1-1185 ,Biotechnology ,TP248.13-248.65 ,Science ,Physics ,QC1-999 - Abstract
Abstract Manganese oxide (MnO) nanocubes were fabricated and their surface were modified by ligand encapsulation or ligand exchange, to render them water-soluble. And then, MnO formed the hollow structure by etching using acidic solution (phthalate buffer, pH 4.0). Depending on the ligand of the MnO surface, it increases the interaction between MnO and water molecules. Also, the hollow structure of MnO, as well as the ligand, can greatly enhance the accessibility of water molecules to metal ions by surface area-to-volume ratio. These factors provide high R1 relaxation, leading to strong T1 MRI signal. We have confirmed T1-weighted MR contrast effect using 4-kinds of MnO nanocubes (MnOEn, MnOEnHo, MnOEx and MnOExHo). They showed enough a MR contrast effect and biocompatibility. Especially, among them, MnOExHo exhibited high T1 relaxivity (r1) (6.02 mM−1 s−1), even about 1.5 times higher sensitivity than commercial T1 MR contrast agents. In vitro/in vivo studies have shown that MnOExHo provides highly sensitive T1-weighted MR imaging, thereby improving diagnostic visibility at the disease site.
- Published
- 2020
- Full Text
- View/download PDF
12. Deconvolution of diffuse gastric cancer and the suppression of CD34 on the BALB/c nude mice model
- Author
-
Seon-Jin Yoon, Jungmin Park, Youngmin Shin, Yuna Choi, Sahng Wook Park, Seok-Gu Kang, Hye Young Son, and Yong-Min Huh
- Subjects
Diffuse gastric cancer ,CD34 ,Knockdown ,Magnetic resonance imaging ,Histology ,Phenotype ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Gastric cancer is a considerable burden for worldwide patients. And diffuse gastric cancer is the most insidious subgroup with poor survival. The phenotypic characterization of the diffuse gastric cancer cell line can be useful for gastric cancer researchers. In this article, we aimed to characterize the diffuse gastric cancer cells with MRI and transcriptomic data. We hypothesized that gene expression pattern is associated with the phenotype of the cells and that the heterogeneous enhancement pattern and the high tumorigenicity of SNU484 can be modulated by the perturbation of the highly expressed gene. Methods We evaluated the 9.4 T magnetic resonance imaging and transcriptomic data of the orthotopic mice models from diffuse gastric cancer cells such as SNU484, Hs746T, SNU668, and KATO III. We included MKN74 as an intestinal cancer control cell. After comprehensive analysis integrating MRI and transcriptomic data, we selected CD34 and validated the effect by shRNA in the BALB/c nude mice models. Results SNU484, SNU668, Hs746T, and MKN74 formed orthotopic tumors by the 5 weeks after cell injection. The diffuse phenotype was found in the SNU484 and Hs746T. SNU484 was the only tumor showing the heterogeneous enhancement pattern on T2 images with a high level of CD34 expression. Knockdown of CD34 decreased the round-void shape in the H&E staining (P = 0.028), the heterogeneous T2 enhancement, and orthotopic tumorigenicity (100% vs 66.7%). The RNAseq showed that the suppressed CD34 is associated with the downregulated gene-sets of the extracellular matrix remodeling. Conclusion Suppression of CD34 in the human-originated gastric cancer cell suggests that it is important for the round-void histologic shape, heterogeneous enhancement pattern on MRI, and the growth of gastric cancer cell line.
- Published
- 2020
- Full Text
- View/download PDF
13. Development of postbiotics by bioconverting whey using Lactobacillus plantarum SMFM2017-YK1 and Limosilactobacillus fermentum SMFM2017-NK1 to alleviate periodontitis
- Author
-
Yuna Choi, Eunyoung Park, Yohan Yoon, and Jimyeong Ha
- Subjects
Medicine ,Science - Abstract
This study investigated the effects of whey bioconversion products (WBPs) produced by lactic acid bacteria on periodontal disease. WBPs were prepared by fermenting whey with seven lactic acid bacteria, Limosilactobacillus fermentum SMFM2017-CK1 (LF-CK1), L. plantarum SMFM2017-NK2 (LP-NK2), Pediococcus pentosaceus SMFM2017-NK1 (PP-NK1), L. plantarum SMFM2017-NK1 (LP-NK1), L. paraplantarum SMFM2017-YK1 (LPP-YK1), L. plantarum SMFM2017-YK1 (LP-YK1), and L. fermentum SMFM2017-NK1 (LF-NK1)]; the pH of the fermented whey was adjusted to 6.5, followed by centrifugation. WBPs were examined for their effect on cell viability and antimicrobial activity against periodontal pathogens. The selected WBPs were used in animal experiments. After inducing periodontitis through right mandibular first molar ligation, WBPs were administered orally for 8 weeks. After sacrifice, gene and protein expression analyses of genes related to inflammatory and oxidative stress were performed, and histopathological analysis of gingival tissue was conducted. Our results showed that LP-YK1 WBP (WBP produced by LP-YK1) and LF-NK1 WBP (WBP produced by LF-NK1) groups exerted higher anti-inflammatory and antioxidant effects compared to the control group (p < 0.05). Histopathological analysis revealed that infiltration of inflammatory cells and epithelial cell proliferation were reduced in the LP-YK1 WBP group. These results indicate that WBPs prepared with LP-YK1 can be used as a postbiotic to alleviate periodontitis.
- Published
- 2022
14. Metal artifact reduction and tumor detection using photon-counting multi-energy computed tomography.
- Author
-
Chang-Lae Lee, Junyoung Park, Sangnam Nam, Jiyoung Choi, Yuna Choi, Sangmin Lee, Kyoung-Yong Lee, and Minkook Cho
- Subjects
Medicine ,Science - Abstract
Metal artifacts are considered a major challenge in computed tomography (CT) as these adversely affect the diagnosis and treatment of patients. Several approaches have been developed to address this problem. The present study explored the clinical potential of a novel photon-counting detector (PCD) CT system in reducing metal artifacts in head CT scans. In particular, we studied the recovery of an oral tumor region located under metal artifacts after correction. Three energy thresholds were used to group data into three bins (bin 1: low-energy, bin 2: middle-energy, and bin 3: high-energy) in the prototype PCD CT system. Three types of physical phantoms were scanned on the prototype PCD CT system. First, we assessed the accuracy of iodine quantification using iodine phantoms at varying concentrations. Second, we evaluated the performance of material decomposition (MD) and virtual monochromatic images (VMIs) using a multi-energy CT phantom. Third, we designed an ATOM phantom with metal insertions to verify the effect of the proposed metal artifact reduction. In particular, we placed an insertion-mimicking an iodine-enhanced oral tumor in the beam path of metallic objects. Normalized metal artifact reduction (NMAR) was performed for each energy bin image, followed by an image-based MD and VMI reconstruction. Image quality was analyzed quantitatively by contrast-to-noise ratio (CNR) measurements. The results of iodine quantification showed a good match between the true and measured iodine concentrations. Furthermore, as expected, the contrast between iodine and the surrounding material was higher in bin 1 image than in bin 3 image. On the other hand, the bin 3 image of the ATOM phantom showed fewer metal artifacts than the bin 1 image because of the higher photon energy. The result of quantitative assessment demonstrated that the 40-keV VMI (CNR: 20.6 ± 1.2) with NMAR and MD remarkably increased the contrast of the iodine-enhanced region compared with that of the conventional images (CNR: 10.4 ± 0.5) having 30 to 140 keV energy levels. The PCD-based multi-energy CT imaging has immense potential to maximize the contrast of the target tissue and reduce metal artifacts simultaneously. We believe that it would open the door to novel applications for the diagnosis and treatment of several diseases.
- Published
- 2021
- Full Text
- View/download PDF
15. Prevalence of common causes of neuropathic pain in Korea: population-based observational study
- Author
-
Seunguk Bang, Yee Suk Kim, Soyeon Lee, Uijin Park, Tae-kwan Kim, and Yuna Choi
- Subjects
Medicine (General) ,R5-920 - Abstract
Objective To investigate the prevalence of complex regional pain syndrome (CRPS), post-herpetic neuralgia (PHN), trigeminal neuralgia (TN), and diabetic neuropathy (DN), common causes of neuropathic pain encountered in pain clinics. Methods We investigated the period prevalence rate of CRPS, PHN, TN, and DN using data from a Korean national electronic database from 2009 to 2013. Results The prevalence of CRPS decreased slightly throughout the study period, while the prevalence of PHN increased from 2009 to 2013. The prevalence of TN was reduced over the same period. The prevalence of DN increased from 2009 to 2012 but decreased in 2013. All four neuropathic diseases were more prevalent in individuals aged over 70 years. The prevalence of CRPS, PHN, and TN were more common in women than in men, but DN showed no gender difference. Conclusion While the prevalence of CRPS and TN has decreased in Korea, that of PHN and DN has increased. With the exception of DN, the neuropathic diseases were more prevalent in women. Further studies are necessary to investigate the risk factors and socioeconomic burden for each disease, and national efforts are essential to limit the development of these preventable neuropathic diseases.
- Published
- 2020
- Full Text
- View/download PDF
16. Urban Effect on Sea-Breeze-Initiated Rainfall: A Case Study for Seoul Metropolitan Area
- Author
-
Yuna Choi and Young-Hee Lee
- Subjects
afternoon rainfall ,sea breeze ,UHIC ,Meteorology. Climatology ,QC851-999 - Abstract
We examined the sea-breeze-initiated rainfall in the Seoul Metropolitan area (SMA) on 6 July 2017 using the weather research and forecasting (WRF) model. The model captures the arrival of the sea breeze front (SBF), the development of afternoon rainfall in the SMA, and the location of the sea-breeze-initiated maximum rainfall in the northeastern SMA reasonably well but overestimates the subsequent rainfall. We conducted sensitivity tests to better understand the urban effect on the sea-breeze-initiated rainfall event. Through factor separation analysis, we first examined the explicit role of sea and urban effect on sea-breeze-initiated rainfall. The results show that the interaction of sea and urban effects cause rainfall in the northwest and northeast of the SMA, indicating that both urban heat island circulation (UHIC) and sea breeze play an important role in the study case’s rainfall. We further examined the relative role of urban roughness and anthropogenic heat on the sea-breeze-initiated rainfall through factor separation analysis. Both anthropogenic heat and urban roughness play a role in increasing precipitation in the northeastern area of the SMA, with a larger contribution of anthropogenic heat than urban roughness. The relationship between low-level convergence at the SBF and urban factors is discussed.
- Published
- 2021
- Full Text
- View/download PDF
17. Correction to: Design framework for a seamless smart glove using a digital knitting system
- Author
-
Yewon Song, Seulah Lee, Yuna Choi, Sora Han, Hyuna Won, Tae-Hyun Sung, Youngjin Choi, and Jihyun Bae
- Subjects
Textile bleaching, dyeing, printing, etc. ,TP890-933 ,Social Sciences - Abstract
An amendment to this paper has been published and can be accessed via the original article.
- Published
- 2021
- Full Text
- View/download PDF
18. A Knitted Sensing Glove for Human Hand Postures Pattern Recognition
- Author
-
Seulah Lee, Yuna Choi, Minchang Sung, Jihyun Bae, and Youngjin Choi
- Subjects
knitted sensor ,wearable strain sensor ,data glove ,fabric sensor ,pattern recognition ,Chemical technology ,TP1-1185 - Abstract
In recent years, flexible sensors for data gloves have been developed that aim to achieve excellent wearability, but they are associated with difficulties due to the complicated manufacturing and embedding into the glove. This study proposes a knitted glove integrated with strain sensors for pattern recognition of hand postures. The proposed sensing glove is fabricated at all once by a knitting technique without sewing and bonding, which is composed of strain sensors knitted with conductive yarn and a glove body with non-conductive yarn. To verify the performance of the developed glove, electrical resistance variations were measured according to the flexed angle and speed. These data showed different values depending on the speed or angle of movements. We carried out experiments on hand postures pattern recognition for the practicability verification of the knitted sensing glove. For this purpose, 10 able-bodied subjects participated in the recognition experiments on 10 target hand postures. The average classification accuracy of 10 subjects reached 94.17% when their own data were used. The accuracy of up to 97.1% was achieved in the case of grasp posture among 10 target postures. When all mixed data from 10 subjects were utilized for pattern recognition, the average classification expressed by the confusion matrix arrived at 89.5%. Therefore, the comprehensive experimental results demonstrated the effectiveness of the knitted sensing gloves. In addition, it is expected to reduce the cost through a simple manufacturing process of the knitted sensing glove.
- Published
- 2021
- Full Text
- View/download PDF
19. Robust Real-Time Detection of Laparoscopic Instruments in Robot Surgery Using Convolutional Neural Networks with Motion Vector Prediction
- Author
-
Kyungmin Jo, Yuna Choi, Jaesoon Choi, and Jong Woo Chung
- Subjects
robot surgery ,tool detection ,YOLO ,CNN ,real-time ,convolutional neural networks ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
More than half of post-operative complications can be prevented, and operation performances can be improved based on the feedback gathered from operations or notifications of the risks during operations in real time. However, existing surgical analysis methods are limited, because they involve time-consuming processes and subjective opinions. Therefore, the detection of surgical instruments is necessary for (a) conducting objective analyses, or (b) providing risk notifications associated with a surgical procedure in real time. We propose a new real-time detection algorithm for detection of surgical instruments using convolutional neural networks (CNNs). This algorithm is based on an object detection system YOLO9000 and ensures continuity of detection of the surgical tools in successive imaging frames based on motion vector prediction. This method exhibits a constant performance irrespective of a surgical instrument class, while the mean average precision (mAP) of all the tools is 84.7, with a speed of 38 frames per second (FPS).
- Published
- 2019
- Full Text
- View/download PDF
20. PEGylated Magnetic Nano-Assemblies as Contrast Agents for Effective T2-Weighted MR Imaging
- Author
-
Byunghoon Kang, Jaewoo Lim, Hye-young Son, Yuna Choi, Taejoon Kang, Juyeon Jung, Yong-Min Huh, Seungjoo Haam, and Eun-Kyung Lim
- Subjects
Magnetic resonance image ,PEGylated ,Poly(ethylene glycol)-poly(lactic acid) ,contrast agent ,Chemistry ,QD1-999 - Abstract
We designed a high-sensitivity magnetic resonance imaging contrast agent that could be used to diagnose diseases. First, magnetic nanocrystals were synthesized by a thermal decomposition method on an organic solvent to obtain a high magnetism and methoxy poly(ethylene glycol)-poly(lactic acid) as an amphiphilic polymer using the ring-opening polymerization method to stably disperse the magnetic nanocrystals in an aqueous phase. Subsequently, the magnetic nanoclusters simultaneously self-assembled with methoxy poly(ethylene glycol)-poly(lactic acid) using the nano-emulsion method to form magnetic nanoclusters. Because their shape was similar to a raspberry, they were named PEGylated magnetic nano-assemblies. The PEGylated magnetic nano-assemblies were dispersed stably in the aqueous phase with a uniform size of approximately 65–70 nm for an extended period (0 days: 68.8 ± 5.1 nm, 33 days: 69.2 ± 2.0 nm, and 44 days: 63.2 ± 5.6). They exhibited both enough of a magnetic resonance (MR) contrast effect and biocompatibility. In an in vivo study, the PEGylated magnetic nano-assemblies provided a high contrast effect for magnetic resonance images for a long time after one treatment, thereby improving the diagnostic visibility of the disease site.
- Published
- 2019
- Full Text
- View/download PDF
21. Overexpressing the hydroxycarboxylic acid receptor 1 in mouse brown adipose tissue restores glucose tolerance and insulin sensitivity in diet-induced obese mice
- Author
-
Hyeon-Young Min, Jiyeon Hwang, Yuna Choi, and Young-Hwan Jo
- Subjects
Male ,Physiology ,Endocrinology, Diabetes and Metabolism ,Body Weight ,Mice, Obese ,Diet ,Receptors, G-Protein-Coupled ,Mice, Inbred C57BL ,Mice ,Glucose ,Adipose Tissue ,Adipose Tissue, Brown ,Physiology (medical) ,Lactates ,Animals ,Obesity ,Insulin Resistance - Abstract
Interscapular brown adipose tissue (BAT) plays an important role in controlling glucose homeostasis. Increased glucose entry and glycolysis in BAT result in lactate production and release. The adipose tissue expresses the lactate receptor hydrocarboxylic acid receptor 1 (HCAR1), markedly downregulated in male diet-induced obese (DIO) and
- Published
- 2023
22. Trajectory Estimation of Center of Plantar Foot Pressure Using Gaussian Process Regression
- Author
-
Yuna Choi, Daehun Lee, and Youngjin Choi
- Published
- 2022
- Full Text
- View/download PDF
23. Attenuation of Experimental Autoimmune Uveitis in Lewis Rats by Betaine
- Author
-
Taekyun Shin, Hyo Jin Kim, Yuna Choi, Hiroshi Matsuda, Changjong Moon, Youngheun Jee, Jeongtae Kim, Akane Tanaka, Jiyoon Chun, Kyungsook Jung, Hyun Ju Ko, and Meejung Ahn
- Subjects
Experimental autoimmune uveitis ,T cell ,Inflammation ,Retina ,Superoxide dismutase ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Anti-oxidation ,Betaine ,Downregulation and upregulation ,Antigen ,Anti-inflammation ,medicine ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Chemistry ,Cell adhesion molecule ,Molecular biology ,eye diseases ,medicine.anatomical_structure ,biology.protein ,Original Article ,Neurology (clinical) ,medicine.symptom - Abstract
Experimental autoimmune uveitis (EAU) is an animal model of human autoimmune uveitis that is characterized by the infiltration of autoimmune T cells with concurrent increases in pro-inflammatory cytokines and reactive oxygen species. This study aimed to assess whether betaine regulates the progression of EAU in Lewis rats. EAU was induced via immunization with the interphotoreceptor retinoid-binding protein (IRBP) and oral administration of either a vehicle or betaine (100 mg/kg) for 9 consecutive days. Spleens, blood, and retinas were sampled from the experimental rats at the time of sacrifice and used for the T cell proliferation assay, serological analysis, real-time polymerase chain reaction, and immunohistochemistry. The T cell proliferation assay revealed that betaine had little effect on the proliferation of splenic T cells against the IRBP antigen in an in vitro assay on day 9 post-immunization. The serological analysis showed that the level of serum superoxide dismutase increased in the betaine-treated group compared with that in the vehicle-treated group. The anti-inflammatory effect of betaine was confirmed by the downregulation of pro-inflammation-related molecules, including vascular cell adhesion molecule 1 and interleukin-1β in the retinas of rats with EAU. The histopathological findings agreed with those of ionized calcium-binding adaptor molecule 1 immunohistochemistry, further verifying that inflammation in the retina and ciliary bodies was significantly suppressed in the betaine-treated group compared with the vehicle-treated group. Results of the present study suggest that betaine is involved in mitigating EAU through anti-oxidation and anti-inflammatory activities.
- Published
- 2021
- Full Text
- View/download PDF
24. Magel2 knockdown in hypothalamic POMC neurons innervating the medial amygdala reduces susceptibility to diet-induced obesity.
- Author
-
Yuna Choi, Hyeon-Young Min, Jiyeon Hwang, Young-Hwan Jo, Yuna Choi, Hyeon-Young Min, Jiyeon Hwang, and Young-Hwan Jo
- Published
- 2022
- Full Text
- View/download PDF
25. Design framework for a seamless smart glove using a digital knitting system
- Author
-
Sora Han, Seulah Lee, Hyuna Won, Yuna Choi, Jihyun Bae, Youngjin Choi, Yewon Son, and Tae Hyun Sung
- Subjects
Cultural Studies ,Textile ,Seamless glove sensor ,Social Psychology ,Process (engineering) ,Computer science ,Finger motion detection ,Strategy and Management ,Materials Science (miscellaneous) ,Framework for wearable electronics ,Wearable computer ,CAD ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,lcsh:Social Sciences ,lcsh:TP890-933 ,Sensitivity (control systems) ,Wearable technology ,Marketing ,Design framework ,Digital knitting CAD/CAM system ,business.industry ,Robotic finger ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,lcsh:H ,Systems engineering ,lcsh:Textile bleaching, dyeing, printing, etc ,0210 nano-technology ,business - Abstract
The wearable electronics integrated with textile-based devices is a promising strategy to meet the requirements of human comfort as well as electrical performances. This research presents a design and development framework for a seamless glove sensor system using digital knitting fabrication. Based on the performance requirements of glove sensors for controlling a prosthetic hand, desirable design components include electrical conductivity, comfort, formfit, electrical sensitivity, and customizable design. These attributes are determined and achieved by applying appropriate materials and fabrication technologies. In this study, a digital knitting CAD/CAM system is utilized to meet the desired performance criteria, and two prototypes of the seamless glove sensor systems are successfully developed for the detection of both human and robotic finger motions. This digital knitting system will provide considerable potential for customized design development as well as a sustainable production process. This structured, systematic approach could be adapted in the future development of wearable electronic textile systems.
- Published
- 2021
26. Planetary Boundary-Layer Structure at an Inland Urban Site under Sea Breeze Penetration
- Author
-
Moon-Soo Park, Young-Hee Lee, and Yuna Choi
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Urban climatology ,Advection ,Planetary boundary layer ,Microwave radiometer ,0207 environmental engineering ,02 engineering and technology ,01 natural sciences ,Ceilometer ,Bulk Richardson number ,Sea breeze ,Weather Research and Forecasting Model ,Climatology ,Environmental science ,020701 environmental engineering ,0105 earth and related environmental sciences - Abstract
We evaluated the performance of the Weather Research and Forecasting Model in simulating the boundary-layer structure at an urban site in Seoul on two clear summer days against observations made using a ceilometer, a Doppler wind lidar, and a microwave radiometer. The planetary boundary-layer height (PBLH) was estimated from two different methods using observations: the ceilometer-based method (CBM) and bulk Richardson number method (BRM). The maximum PBLH was well captured by the model but PBLH was underestimated in the late afternoon and evening. To examine the cause for underestimation of PBLH in the evening, we compared the wind and virtual potential temperature structure between the simulation and observations. The model captured the timing of the sea breeze well, but it considerably overestimated the intensity of the simulated sea breeze, resulting in an overestimated cold advection by a sea breeze. The effect of the overestimated cold advection on evening PBLH was greater when the sea breeze arrived in the late afternoon and hence the vertical extent of the sea breeze was shallow. This study underscores the importance of accurately simulating the sea breeze for PBLH prediction in the evening, over the inland urban areas under sea breeze penetration.
- Published
- 2021
- Full Text
- View/download PDF
27. MRI measurement of alanine uptake in a mouse xenograft model of U-87 MG glioblastoma
- Author
-
Seung-Hyun Yang, Yuna Choi, Mirae Park, Hye-Young Son, Yong-Min Huh, and Chan Gyu Joo
- Subjects
Amino Acid Transport System ASC ,Minor Histocompatibility Antigens ,Mice ,Alanine ,Biomedical Engineering ,Biophysics ,Animals ,Heterografts ,Humans ,Radiology, Nuclear Medicine and imaging ,Protons ,Glioblastoma ,Magnetic Resonance Imaging - Abstract
The potential use of alanine as an MRI contrast agent was investigated. The relaxation properties of alanine solutions were measured at 9.4 T. The T
- Published
- 2022
28. Enantioselective 1,2-Addition of α-Aminoalkyl Radical to Aldehydes via Visible-Light Photoredox Initiated Chiral Oxazaborolidinium Ion Catalysis
- Author
-
Yea Suel Lee, Jae Yeon Kim, Do Hyun Ryu, and Yuna Choi
- Subjects
010405 organic chemistry ,Chemistry ,Enantioselective synthesis ,General Chemistry ,Optically active ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Ion ,Lewis acids and bases ,Visible spectrum - Abstract
Enantioselective 1,2-addition reaction of α-aminoalkyl radical to α,β-unsaturated or aromatic aldehydes to synthesize highly optically active β-amino alcohols has been developed. In the presence of...
- Published
- 2020
- Full Text
- View/download PDF
29. Upregulation of Cathepsins in Olfactory Bulbs Is Associated with Transient Olfactory Dysfunction in Mice with Experimental Autoimmune Encephalomyelitis
- Author
-
Yuna Choi, Meejung Ahn, Taekyun Shin, and Jeongtae Kim
- Subjects
0301 basic medicine ,Cathepsin ,Glomerulus (olfaction) ,Microglia ,Experimental autoimmune encephalomyelitis ,Neuroscience (miscellaneous) ,Proteolytic enzymes ,Biology ,medicine.disease ,Molecular biology ,Olfactory bulb ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Neurology ,Gliosis ,Downregulation and upregulation ,medicine ,medicine.symptom ,030217 neurology & neurosurgery - Abstract
Cathepsins are a family of lysosomal/endosomal proteolytic enzymes that include serine, aspartate, and cysteine proteases. The role of cathepsin in neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, remains elusive. We evaluated the expression level and localization of different cathepsins in the olfactory bulbs of mice with experimental autoimmune encephalomyelitis (EAE), a model of human multiple sclerosis. Quantitative real-time PCR results and Western blotting analyses revealed that serine, aspartate, and cysteine cathepsins are expressed at significantly higher levels in the olfactory bulbs of mice with EAE in the paralytic stage compared with those of control mice. Immunohistochemical analyses indicated that cathepsin A, D, and S were expressed in the glomerulus layer, external plexiform layer, and mitral cell layer. Furthermore, cathepsins were detected in astrocytes, microglia, inflammatory cells, and vascular cells in the olfactory bulb of EAE mice at the paralytic stage. Collectively, these results suggest that the upregulation of cathepsins in the olfactory bulb of mice with EAE is associated with transient olfactory dysfunction in autoimmune encephalomyelitis.
- Published
- 2020
- Full Text
- View/download PDF
30. Alpha-Linolenic Acid Alleviates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice
- Author
-
Jung Eun Kim, Meejung Ahn, Gi Ok Kim, Taekyun Shin, Jeongtae Kim, Nam Ho Lee, Tae-Young Kang, and Yuna Choi
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Immunology ,Crypt ,Inflammation ,Inflammatory bowel disease ,Gastroenterology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,medicine ,Immunology and Allergy ,Large intestine ,Colitis ,Goblet cell ,business.industry ,alpha-Linolenic acid ,medicine.disease ,Ulcerative colitis ,digestive system diseases ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,030220 oncology & carcinogenesis ,medicine.symptom ,business - Abstract
Ulcerative colitis (UC) is a type of inflammatory bowel disease characterized by inflammation of the large intestine, rectal bleeding, and abdominal pain. It can be alleviated by certain bioactive compounds, including α-linolenic acid (ALA), which is a bioactive component in fermented black radish (Raphanus sativus L. var. niger). The aim of this study was to evaluate the anti-inflammatory effects of ALA in dextran sulfate sodium (DSS)-induced UC in mice. UC was induced in C57BL/6 mice by allowing them to freely drink water containing 2.5% DSS for 7 days, followed by oral administration of ALA (30 and 60 mg/kg/day) or vehicle control for 7 days. DSS-induced colitis was evaluated using the Disease Activity Index (DAI) and by measuring colon length and performing a histopathological examination. Compared to the control group, the vehicle-treated group showed a higher DAI score, shorter colon, goblet cell loss, and crypt shortening. The ALA treatment mitigated clinical signs of UC and histopathological changes. Furthermore, it mitigated intestinal inflammation by reducing the expression of ionized calcium binding adaptor molecule 1-positive macrophages in the colon. These results show that ALA alleviates DSS-induced UC by suppressing colon damage, which includes goblet cell loss, crypt shortening, and a reduction of macrophages in the colon.
- Published
- 2020
- Full Text
- View/download PDF
31. L‐glutamine as a T 2 exchange contrast agent
- Author
-
Seung Hyun Yang, Donghyun Kim, Chan Gyu Joo, Yuna Choi, Yong Min Huh, and Hye Young Son
- Subjects
Chemistry ,media_common.quotation_subject ,Glutamate receptor ,Cancer imaging ,030218 nuclear medicine & medical imaging ,Glutamine ,03 medical and health sciences ,0302 clinical medicine ,In vivo ,L-glutamine ,T2 relaxation ,Biophysics ,Contrast (vision) ,Radiology, Nuclear Medicine and imaging ,030217 neurology & neurosurgery ,media_common - Abstract
Purpose The potential of L-glutamine as a T2 exchange contrast agent in MRI was investigated. Methods The T2 relaxation rate of L-glutamine solutions prepared in various concentrations was measured at 9.4 T. A series of T2 -weighted images in a mouse cancer model was acquired with an L-glutamine solution infusion. Results The T2 relaxivity caused by the exchange (R2ex ) at 37°C was 0.069 s-1 mM-1 and 0.102 s-1 mM-1 for glutamine and glutamate solutions at pH = 7.2, respectively. The R2ex of glutamine at pH = 6.1-6.7 was in the 0.097-0.1 s-1 mM-1 range. No significant dependence of T1 on the concentration of glutamine was observed. The dynamic measurement of T2 -weighted images in vivo showed that the glutamine uptake was primarily observed at the localized part of the tumor CONCLUSION: L-glutamine can be used as a T2 exchange contrast agent and images of glutamine uptake in vivo can be acquired.
- Published
- 2020
- Full Text
- View/download PDF
32. Immunohistochemical analysis of periostin in the hearts of Lewis rats with experimental autoimmune myocarditis
- Author
-
Taekyun Shin, Tae-Young Kang, Yuna Choi, Jiyoon Chun, Hanseul Oh, Meejung Ahn, and Jeongtae Kim
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Myocarditis ,040301 veterinary sciences ,Cardiac fibrosis ,autoimmune disease ,Periostin ,Autoimmune Diseases ,0403 veterinary science ,03 medical and health sciences ,Western blot ,Fibrosis ,medicine ,Animals ,030304 developmental biology ,periostin ,Autoimmune disease ,0303 health sciences ,General Veterinary ,medicine.diagnostic_test ,business.industry ,Myocardium ,fibrosis ,04 agricultural and veterinary sciences ,Note ,medicine.disease ,Immunohistochemistry ,Rats ,Disease Models, Animal ,Rats, Inbred Lew ,smooth muscle actin ,business ,Cell Adhesion Molecules ,Homeostasis - Abstract
Periostin plays a critical role in tissue regeneration and homeostasis. The aim of this study was to evaluate the changes in periostin levels in the hearts of rats with experimental autoimmune myocarditis (EAM). Western blot analysis revealed that the expression levels of periostin and alpha-smooth muscle actin were significantly increased at day 14 post-immunization. Immunohistochemical analysis indicated that periostin was expressed in macrophages and fibroblasts in the hearts of EAM-induced rats. In conclusion, these results suggest that increased periostin expression in macrophages and fibroblasts promotes cardiac fibrosis in EAM-induced rats, potentially by enhancing immune cell infiltration. Therefore, periostin should be further investigated as a candidate therapeutic target for myocarditis.
- Published
- 2020
- Full Text
- View/download PDF
33. Enhanced infrared transmittance by modulation of electrical and optical properties of Sm-doped SnO2 thin films
- Author
-
Sang-Seok Lee, Woo-Jin Lee, Yuna Choi, and Il-Kyu Park
- Subjects
General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2023
- Full Text
- View/download PDF
34. Effects of the July 2018 worldwide valsartan recall and shortage on global trends in antihypertensive medication use: a time-series analysis in 83 countries
- Author
-
Yuna Choi, Araniy Santhireswaran, Cherry Chu, Katie J Suda, Inma Hernandez, Jared W Magnani, and Mina Tadrous
- Subjects
General Medicine - Abstract
ObjectivesThis study aims to examine the effects of the July 2018 worldwide valsartan recall and shortage on global trends of antihypertensive medication use in 83 countries.MethodsA time-series analysis of monthly purchases of valsartan, other angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACEIs) across 83 countries from January 2017 to July 2020 was conducted using the IQVIA MIDAS database. Trends in outcomes were investigated globally and by economic level (developed vs developing economies). The valsartan recall’s impact on antihypertensive use was assessed with interventional autoregressive integrated moving average modelling.ResultsGlobal valsartan utilisation trends decreased significantly by 15.7% (−61 166 515 SU; pConclusionsGlobal valsartan purchases substantially decreased post-recall, highlighting the far-reaching impacts of drug shortages. Opposing utilisation trends by economic level raise concerns of potential distribution of contaminated medications from developed countries to developing countries. Concerted actions for equitable global access to quality medications and mitigation of drug shortages are needed.
- Published
- 2023
- Full Text
- View/download PDF
35. Feasibility study of portable multi-energy computed tomography with photon-counting detector for preclinical and clinical applications
- Author
-
Kyoung-Yong Lee, Key Jo Hong, Namwoo Kim, Yuna Choi, Jee Eun Lee, Kwanhee Han, Chang-Lae Lee, Dong-Kyu Kim, Junyoung Park, Min-Kook Cho, Sang-Min Lee, and Hoesu Jung
- Subjects
Male ,Canine brain ,Carcinoma, Hepatocellular ,Image quality ,Computer science ,Science ,Contrast Media ,Computed tomography ,Article ,Medical research ,Dogs ,medicine ,Animals ,Segmentation ,Image resolution ,Photon counting detector ,Cancer ,Photons ,Multidisciplinary ,medicine.diagnostic_test ,Phantoms, Imaging ,Detector ,Liver Neoplasms ,Brain ,Disease Models, Animal ,Optics and photonics ,Medicine ,Feasibility Studies ,Neural Networks, Computer ,Rabbits ,Tomography, X-Ray Computed ,Energy (signal processing) ,Biomedical engineering - Abstract
In this study, preclinical experiments were performed with an in-house developed prototypal photon-counting detector computed tomography (PCD CT) system. The performance of the system was compared with the conventional energy-integrating detector (EID)-based CT, concerning the basic image quality biomarkers and the respective capacities for material separation. The pre- and the post-contrast axial images of a canine brain captured by the PCD CT and EID CT systems were found to be visually similar. Multi-energy images were acquired using the PCD CT system, and machine learning-based material decomposition was performed to segment the white and gray matters for the first time in soft tissue segmentation. Furthermore, to accommodate clinical applications that require high resolution acquisitions, a small, native, high-resolution (HR) detector was implemented on the PCD CT system, and its performance was evaluated based on animal experiments. The HR acquisition mode improved the spatial resolution and delineation of the fine structures in the canine’s nasal turbinates compared to the standard mode. Clinical applications that rely on high-spatial resolution expectedly will also benefit from this resolution-enhancing function. The results demonstrate the potential impact on the brain tissue segmentation, improved detection of the liver tumors, and capacity to reconstruct high-resolution images both preclinically and clinically.
- Published
- 2021
36. Development of postbiotics by bioconverting whey using Lactobacillus plantarum SMFM2017-YK1 and Limosilactobacillus fermentum SMFM2017-NK1 to alleviate periodontitis
- Author
-
Yuna Choi, Eunyoung Park, Yohan Yoon, and Jimyeong Ha
- Subjects
Limosilactobacillus fermentum ,Multidisciplinary ,Whey Proteins ,Anti-Infective Agents ,Lactobacillales ,Whey ,Animals ,Periodontitis ,Antioxidants ,Lactobacillus plantarum - Abstract
This study investigated the effects of whey bioconversion products (WBPs) produced by lactic acid bacteria on periodontal disease. WBPs were prepared by fermenting whey with seven lactic acid bacteria, Limosilactobacillus fermentum SMFM2017-CK1 (LF-CK1), L. plantarum SMFM2017-NK2 (LP-NK2), Pediococcus pentosaceus SMFM2017-NK1 (PP-NK1), L. plantarum SMFM2017-NK1 (LP-NK1), L. paraplantarum SMFM2017-YK1 (LPP-YK1), L. plantarum SMFM2017-YK1 (LP-YK1), and L. fermentum SMFM2017-NK1 (LF-NK1)]; the pH of the fermented whey was adjusted to 6.5, followed by centrifugation. WBPs were examined for their effect on cell viability and antimicrobial activity against periodontal pathogens. The selected WBPs were used in animal experiments. After inducing periodontitis through right mandibular first molar ligation, WBPs were administered orally for 8 weeks. After sacrifice, gene and protein expression analyses of genes related to inflammatory and oxidative stress were performed, and histopathological analysis of gingival tissue was conducted. Our results showed that LP-YK1 WBP (WBP produced by LP-YK1) and LF-NK1 WBP (WBP produced by LF-NK1) groups exerted higher anti-inflammatory and antioxidant effects compared to the control group (p < 0.05). Histopathological analysis revealed that infiltration of inflammatory cells and epithelial cell proliferation were reduced in the LP-YK1 WBP group. These results indicate that WBPs prepared with LP-YK1 can be used as a postbiotic to alleviate periodontitis.
- Published
- 2021
37. Immunohistochemical localization of nerve injury-induced protein-1 in mouse tissues
- Author
-
Meejung Ahn, Taekyun Shin, Jeongtae Kim, Poornima Ekanayake, and Yuna Choi
- Subjects
Pathology ,medicine.medical_specialty ,Cell type ,Histology ,Mouse ,Biology ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Western blot ,medicine ,0303 health sciences ,medicine.diagnostic_test ,Cell adhesion molecule ,Cerebrum ,Ninjurin-1 ,Cell Biology ,Nerve injury ,Blot ,medicine.anatomical_structure ,030301 anatomy & morphology ,nervous system ,Organ ,Immunohistochemistry ,Original Article ,Sciatic nerve ,Anatomy ,medicine.symptom ,Developmental Research ,030217 neurology & neurosurgery ,Developmental Biology - Abstract
Nerve injury-induced protein (Ninjurin)-1 is a cell adhesion molecule that is upregulated in neurons and Schwann cells after transection injury in rats. In this study, we investigated the localization of Ninjurin-1 in various tissues, including the cerebrum, sciatic nerve, spleen, lung, stomach, ileum, colon, liver, pancreas, kidney, testis, and skin in C57BL/6 mice, using Western blotting and immunohistochemistry. Western blot analysis showed that Ninjurin-1 was differentially expressed among organs. Ninjurin-1 was abundant in skin and ileum, weakly expressed in cerebrum, and moderately expressed in the other organs studied. Immunohistochemical analysis largely confirmed the results of the western blot analysis with often localization of Ninjurin-1 in the regions with abundant connective tissues. In addition, Ninjurin-1 was differentially expressed in various cell types in the tissues under the investigation. These findings suggest that Ninjurin-1 may play organ-specific roles in development and homeostasis of many organs.
- Published
- 2019
38. Fermented black radish (Raphanus sativus L. var. niger) attenuates methionine and choline deficient diet‐induced nonalcoholic fatty liver disease in mice
- Author
-
Meejung Ahn, Taekyun Shin, Ji-Yeon Chun, Yuna Choi, Jeongtae Kim, Poornima Ekanayake, Gi-Ok Kim, and Dawun Yang
- Subjects
0301 basic medicine ,medicine.medical_specialty ,MCD diet ,Raphanus ,lcsh:TX341-641 ,Chronic liver disease ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,Adipocyte ,Nonalcoholic fatty liver disease ,medicine ,steatosis ,Choline ,Original Research ,Methionine ,biology ,fermented black radish ,fibrosis ,medicine.disease ,biology.organism_classification ,Fatty acid synthase ,030104 developmental biology ,Endocrinology ,chemistry ,inflammation ,030220 oncology & carcinogenesis ,biology.protein ,Steatosis ,lcsh:Nutrition. Foods and food supply ,Food Science - Abstract
As one of the wide‐ranging form of chronic liver disease, there are only limited therapeutic options for nonalcoholic fatty liver disease (NAFLD). We evaluated whether fermented black radish (Raphanus sativus L. var. niger; FBR) ameliorates lipid accumulation, inflammation, and hepatic fibrosis, which are characteristics of the pathogenesis of NAFLD. Fermented black radish treatment reduced lipid accumulation in 3T3‐L1 adipocytes, which appeared to be associated with the downregulation of adipogenic transcription factors, including sterol regulatory element‐binding protein 1c, CCAAT/enhancer‐binding protein α, peroxisome proliferator‐activated receptor γ, and lipid accumulation‐related genes including adipocyte protein‐2 and fatty acid synthase. Administration of FBR to C57BL/6J mice challenged with methionine and choline deficient (MCD) diet significantly attenuated the increased serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and triglyceride. In addition, treatment with FBR interestingly repressed the hepatic inflammation induced with MCD diet, by lowering the expression of inducible nitric oxide synthase and suppressing the inactivation of macrophages and Kupffer cells in the liver. Fermented black radish was also shown to mitigate liver fibrosis through the inhibition of alpha‐smooth muscle actin, transforming growth factor beta‐1, and collagen type I alpha 1 chain. Our results indicate that FBR ameliorates NAFLD and its related metabolic disease by regulating multiple pathways, suggesting that FBR may be an effective dietary supplement for ameliorating NAFLD.
- Published
- 2019
39. Antifibrotic effects of fermented black radish (Raphanus sativus L. var. niger) on chronic liver injury in rats
- Author
-
Yuna Choi, Meejung Ahn, Taekyun Shin, Gi-Ok Kim, Poornima Ekanayake, and Jeongtae Kim
- Subjects
Raphanus ,CCL4 ,Inflammation ,Pharmacology ,digestive system ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Western blot ,Downregulation and upregulation ,Fibrosis ,parasitic diseases ,medicine ,Sirius Red ,biology ,medicine.diagnostic_test ,Chemistry ,biology.organism_classification ,medicine.disease ,030205 complementary & alternative medicine ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,Carbon tetrachloride ,medicine.symptom - Abstract
We evaluated the antifibrotic effects of fermented black radish (FBR) on carbon tetrachloride (CCl4)-induced chronic liver injury in rats. Serum biochemical analysis indicated that FBR treatment attenuated the upregulation of alanine aminotransferase and aspartate aminotransferase. Moreover, Sirius red staining and histopathological examination revealed decreased fibrosis and inflammation in FBR-treated rats compared with CCl4 + vehicle-treated rats. Western blot analysis of alpha-smooth muscle actin expression levels confirmed the downregulation of fibrosis in the FBR treatment group compared with the CCl4 + vehicle treatment group. These results suggest that FBR treatment suppressed liver fibrosis in CCl4-exposed rats.
- Published
- 2019
- Full Text
- View/download PDF
40. Retrospective investigation of anesthetic management and outcome in patients with deep neck infections
- Author
-
Yuna Choi, Tae Kwane Kim, Hye Jin Yoon, Jun Rho Yoon, Yuri Ko, and Ui Jin Park
- Subjects
business.industry ,Anesthesia ,Anesthetic management ,Medicine ,In patient ,General Medicine ,business ,Airway ,Outcome (game theory) - Published
- 2019
- Full Text
- View/download PDF
41. Efficiency of PetrifilmTM Staph Express Count Plate for the Enumeration of Staphylococcus aureus in Meat, Fishery Product, and Korean Traditional Foods
- Author
-
Yoonjeong Yoo, Soomin Lee, Yuna Choi, Yohan Yoon, Hyunjo Bang, Seungho Choi, and Jimyeong Ha
- Subjects
food.ingredient ,biology ,Baird–Parker agar ,food and beverages ,biology.organism_classification ,medicine.disease_cause ,Petrifilm ,chemistry.chemical_compound ,Filefish ,food ,chemistry ,Staphylococcus aureus ,medicine ,Enumeration ,Agar ,Food science - Abstract
To enumerate Staphylococcus aureus in food, Baird-Parker Agar (BPA) is usually used in the conventional method, However it requires time and space for the preparation and plating, and incubation. Thus, use of the 3MTM PetrifilmTM Staph Express Count Plate (STX Petrifilm) might be appropriate to solve these challenging problems. The purpose of this study was to compare the efficiency of STX Petrifilm with BPA for enumeration of S. aureus in various foods. A mixture of S. aureus strains ATCC29213, ATCC25923, and ATCC13565 was inoculated on marinated pork chop, beef (chuck tender), dried filefish, semi-dried squid, rice cake, and Japchae (stir-fried glass noodles) at 2, 3, 5, and 7 Log CFU/g. S. aureus cell counts were enumerated by spread-plating on STX Petrifilm and BPA after 0 and 24 hours at 4oC (marinated pork chop, beef, semi-dried squid, and stir-fried glass noodles) and 25oC (dried filefish and rice cake). Recovery of STX Petrifilm for S. aureus from various food samples was compared with BPA, and the results showed that there were no significant differences between two selective media in all cases. The results indicated that STX Petrifilm had enough efficiency to recover S. aureus from various foods as well as saving time and space.
- Published
- 2019
- Full Text
- View/download PDF
42. Efficient Self-Assembled MicroRNA Delivery System Consisting of Cholesterol-Conjugated MicroRNA and PEGylated Polycationic Polymer for Tumor Treatment
- Author
-
Seungjoo Haam, Seungmin Han, Byeonggeol Mun, Hye Young Son, Eunji Jang, Yuna Choi, and Yong Min Huh
- Subjects
chemistry.chemical_classification ,Cholesterol ,Biochemistry (medical) ,Biomedical Engineering ,Endogeny ,General Chemistry ,Polymer ,Conjugated system ,Self assembled ,Biomaterials ,chemistry.chemical_compound ,chemistry ,In vivo ,RNA interference ,microRNA ,Cancer research - Abstract
MicroRNA (miR), a key molecule involved in endogenous RNA interference, is a promising therapeutic agent. In vivo delivery of miR, however, is a major factor limiting its application because its po...
- Published
- 2019
- Full Text
- View/download PDF
43. Investigation of Keratinizing Squamous Cell Carcinoma of the Tongue Using Terahertz Reflection Imaging
- Author
-
Yong Min Huh, Young Han Lee, Young Bin Ji, Yoon Woo Koh, Jung Min Kim, Da Hee Kim, Yuna Choi, Jin Suck Suh, and Seung Jae Oh
- Subjects
010302 applied physics ,Pathology ,medicine.medical_specialty ,Radiation ,integumentary system ,Chemistry ,Terahertz radiation ,High water content ,Condensed Matter Physics ,01 natural sciences ,Tumor tissue ,Terahertz spectroscopy and technology ,010309 optics ,stomatognathic diseases ,medicine.anatomical_structure ,Keratinizing Squamous Cell Carcinoma ,Tongue ,0103 physical sciences ,Reflection (physics) ,medicine ,Electrical and Electronic Engineering ,Instrumentation ,Keratin pearl - Abstract
We investigated the feasibility of using terahertz (THz) reflection imaging to detect keratinizing squamous cell carcinoma (SCC) of the tongue. Four fresh keratinizing SCC tissues were studied, which had been surgically resected. All of the keratinizing SCCs were well distinguished from normal healthy tissues. We showed that the tumor regions exhibited low THz reflection despite having higher water content than normal regions. The refractive indices and absorption coefficients were low in the tumor tissues despite the relatively high water content. Our results showed that there were dominant factors such as keratin pearls, other than the water content affecting the THz reflection signal.
- Published
- 2019
- Full Text
- View/download PDF
44. Magel2knockdown in hypothalamic POMC neurons innervating the medial amygdala reduces susceptibility to diet-induced obesity
- Author
-
Yuna Choi, Hyeon-Young Min, Jiyeon Hwang, and Young-Hwan Jo
- Subjects
Ecology ,Health, Toxicology and Mutagenesis ,Plant Science ,Biochemistry, Genetics and Molecular Biology (miscellaneous) - Abstract
Hyperphagia and obesity profoundly affect the health of children with Prader–Willi syndrome (PWS). TheMagel2gene among the genes in the Prader–Willi syndrome deletion region is expressed in proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC). Knockout of theMagel2gene disrupts POMC neuronal circuits and functions. Here, we report that loss of theMagel2gene exclusively in ARCPOMCneurons innervating the medial amygdala (MeA) causes a reduction in body weight in both male and female mice fed with a high-fat diet. This anti-obesity effect is associated with an increased locomotor activity. There are no significant differences in glucose and insulin tolerance in mice without theMagel2gene in ARCPOMCneurons innervating the MeA. Plasma estrogen levels are higher in female mutant mice than in controls. Blockade of the G protein–coupled estrogen receptor (GPER), but not estrogen receptor-α (ER-α), reduces locomotor activity in female mutant mice. Hence, our study provides evidence that knockdown of theMagel2gene in ARCPOMCneurons innervating the MeA reduces susceptibility to diet-induced obesity with increased locomotor activity through activation of central GPER.
- Published
- 2022
- Full Text
- View/download PDF
45. Immunomagnetic microfluidic integrated system for potency-based multiple separation of heterogeneous stem cells with high throughput capabilities
- Author
-
Eun Kyung Lim, Seungjoo Haam, Seungmin Han, Byunghoon Kang, Yong Min Huh, Byeonggeol Mun, Jeong-Ki Min, Yuna Choi, Moo-Kwang Shin, Jongjin Park, Hye Young Son, and Daewon Park
- Subjects
Pluripotent Stem Cells ,Chemistry ,Microfluidics ,Biomedical Engineering ,Biophysics ,Cell Differentiation ,General Medicine ,Biosensing Techniques ,Cell Separation ,Regenerative medicine ,Cell biology ,Electrochemistry ,Magnetic nanoparticles ,Potency ,Stem cell ,Induced pluripotent stem cell ,Throughput (business) ,Biotechnology ,Adult stem cell - Abstract
Multipotent adult stem cells (MASCs) derived from Pluripotent stem cells (PSCs) have found widespread use in various applications, including regenerative therapy and drug screening. For these applications, highly pluripotent PSCs need to be selectively separated from those that show low pluripotency for reusage of PSCs, and MASCs need to be collected for further application. Herein, we developed immunomagnetic microfluidic integrated system (IM-MIS) for separation of stem cells depending on potency level. In this system, each stem cell was multiple-separated in microfluidics chip by magnetophoretic mobility of magnetic-activated cells based on the combination of two sizes of magnetic nanoparticles and two different antibodies. Magnetic particles had a difference in the degree of magnetization, and antibodies recognized potency-related surface markers. IM-MIS showed superior cell separation performance than FACS with high throughput (49.5%) in a short time (15 min) isolate 1 × 10
- Published
- 2021
46. Genetic changes and growth promotion of glioblastoma by magnetic nanoparticles and a magnetic field
- Author
-
Hyun Wook Rho, Seung Hyun Yang, Yong Min Huh, Yuna Choi, Hye Young Son, and Byeunghoon Kang
- Subjects
Biomedical Engineering ,Medicine (miscellaneous) ,Bioengineering ,02 engineering and technology ,Development ,03 medical and health sciences ,In vivo ,Cell Line, Tumor ,medicine ,Animals ,General Materials Science ,Magnetite Nanoparticles ,Wnt Signaling Pathway ,beta Catenin ,030304 developmental biology ,Cell Proliferation ,0303 health sciences ,Chemistry ,Wnt signaling pathway ,LRP6 ,equipment and supplies ,021001 nanoscience & nanotechnology ,medicine.disease ,In vitro ,Magnetic field ,Cell biology ,Magnetic Fields ,Magnetic nanoparticles ,Signal transduction ,0210 nano-technology ,Glioblastoma ,human activities - Abstract
Aim: To confirm the biological effects of manganese ferrite magnetic nanoparticles (MFMNPs) and an external magnetic field on glioblastoma cells. Methods: U-87MG glioblastoma cells were prepared, into which the uptake of MFMNPs was high. The cells were then exposed to an external magnetic field using a neodymium magnet in vitro and in vivo. Results: LRP6 and TCF7 mRNA levels involved in the Wnt/β-catenin signaling pathway were elevated by the influence of MFMNPs and the external magnetic field. MFMNPs and the external magnetic field also accelerated tumor growth by approximately 7 days and decreased survival rates in animal experiments. Conclusion: When MFMNPs and an external magnetic field are applied for a long time on glioblastoma cells, mRNA expression related to Wnt/β-catenin signaling is increased and tumor growth is promoted.
- Published
- 2021
47. Overexpressing the hydroxycarboxylic acid receptor 1 in mouse brown adipose tissue restores glucose tolerance and insulin sensitivity in diet-induced obese mice.
- Author
-
Hyeon-Young Min, Jiyeon Hwang, Yuna Choi, and Young-Hwan Jo
- Subjects
BROWN adipose tissue ,INSULIN sensitivity ,INSULIN resistance ,INSULIN receptors ,GENETIC overexpression ,MONOCARBOXYLATE transporters ,GLUCOSE - Abstract
Interscapular brown adipose tissue (BAT) plays an important role in controlling glucose homeostasis. Increased glucose entry and glycolysis in BAT result in lactate production and release. The adipose tissue expresses the lactate receptor hydrocarboxylic acid receptor 1 (HCAR1), markedly downregulated in male diet-induced obese (DIO) and ob/ob mice. In this study, we examined the role of HCAR1 in BAT in controlling glucose homeostasis in male DIO mice. We overexpressed HCAR1 in BAT by injecting adeno-associated viruses (AAVs) expressing HCAR1 into the BAT pads of male DIO C57BL/6J mice. Overexpressing HCAR1 in BAT resulted in augmented glucose uptake by BAT in response to treatment with the HCAR1 agonist. HCAR1 overexpression elevated BAT temperature associated with increased thermogenic gene expression in BAT. HCAR1 overexpression prevented body weight gain in male DIO mice. Importantly, mice overexpressing HCAR1 in BAT exhibited improved glucose tolerance and insulin sensitivity. HCAR1 overexpression upregulated the Slc2a4 gene expression and promoted GLUT4 trafficking to the plasma membrane. In addition, mice overexpressing HCAR1 displayed a decrease in hormone-sensitive lipase (HSL) phosphorylation and increased lipogenic enzyme gene expression in BAT. Unlike DIO mice, overexpressing HCAR1 in BAT of mice fed a low-fat diet did not change body weight gain and glucose homeostasis. Taken together, our results support the interpretation that HCAR1 expressed in BAT promotes glucose entry and reduces lipolysis in BAT of male DIO mice. As activation of HCAR1 in BAT restores body weight, glucose tolerance, and insulin sensitivity in male DIO mice, our study suggests that interoceptive lactate detection via HCAR1 in BAT can regulate glucose and lipid substrate utilization and/or availability to promote healthy metabolism. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. Ninjurin-1: a biomarker for reflecting the process of neuroinflammation after spinal cord injury
- Author
-
Meejung Ahn, Taekyun Shin, Yuna Choi, Jeongtae Kim, Changjong Moon, and Poornima D. E. Weerasinghe-Mudiyanselage
- Subjects
Pathology ,medicine.medical_specialty ,Ependymal Cell ,microglia ,macrophage ,lcsh:RC346-429 ,neuroinflammation ,Developmental Neuroscience ,Medicine ,clip compression injury ,rat ,Spinal cord injury ,lcsh:Neurology. Diseases of the nervous system ,Neuroinflammation ,Microglia ,business.industry ,Ninjurin-1 ,astrocytes ,spinal cord ,medicine.disease ,Spinal cord ,Pathophysiology ,medicine.anatomical_structure ,ninjurin-1 ,Peripheral nervous system ,business ,Immunostaining ,Research Article - Abstract
Previous studies have shown that Ninjurin-1 participates in cell trafficking and axonal growth following central and peripheral nervous system neuroinflammation. But its precise roles in these processes and involvement in spinal cord injury pathophysiology remain unclear. Western blot assay revealed that Ninjurin-1 levels in rats with spinal cord injury exhibited an upregulation until day 4 post-injury and slightly decreased thereafter compared with sham controls. Immunohistochemistry analysis revealed that Ninjurin-1 immunoreactivity in rats with spinal cord injury sharply increased on days 1 and 4 post-injury and slightly decreased on days 7 and 21 post-injury compared with sham controls. Ninjurin-1 immunostaining was weak in vascular endothelial cells, ependymal cells, and some glial cells in sham controls while it was relatively strong in macrophages, microglia, and reactive astrocytes. These findings suggest that a variety of cells, including vascular endothelial cells, macrophages, and microglia, secrete Ninjurin-1 and they participate in the pathophysiology of compression-induced spinal cord injury. All experimental procedures were approved by the Care and Use of Laboratory Animals of Jeju National University (approval No. 2018-0029) on July 6, 2018.
- Published
- 2020
49. In vivo monitoring platform of transplanted human stem cells using magnetic resonance imaging
- Author
-
Byunghoon Kang, Hye Young Son, Yuna Choi, Eun Kyung Lim, Moo Kwang Shin, Daewon Park, Jeong Ki Min, Yong Min Huh, Seungmin Han, Jongjin Park, and Seungjoo Haam
- Subjects
Integrin β1 ,medicine.medical_treatment ,Induced Pluripotent Stem Cells ,Biomedical Engineering ,Biophysics ,02 engineering and technology ,Biosensing Techniques ,Biology ,01 natural sciences ,Regenerative medicine ,In vivo ,Electrochemistry ,medicine ,Humans ,medicine.diagnostic_test ,010401 analytical chemistry ,Magnetic resonance imaging ,Cell Differentiation ,General Medicine ,Stem-cell therapy ,021001 nanoscience & nanotechnology ,Magnetic Resonance Imaging ,0104 chemical sciences ,Cell biology ,Transplantation ,biology.protein ,Stem cell ,Antibody ,0210 nano-technology ,Biotechnology ,Stem Cell Transplantation - Abstract
As stem cells show great promise in regenerative therapy, stem cell-mediated therapeutic efficacy must be demonstrated through the migration and transplantation of stem cells into target disease areas at the pre-clinical level. In this study, we developed manganese-based magnetic nanoparticles with hollow structures (MnOHo) and modified them with the anti-human integrin β1 antibody (MnOHo-Ab) to enable the minimal-invasive monitoring of transplanted human stem cells at the pre-clinical level. Compared to common magnetic resonance imaging (MRI)-based stem cell monitoring systems that use pre-labeled stem cells with magnetic particles before stem cell injection, the MnOHo-Ab is a new technology that does not require stem cell modification to monitor the therapeutic capability of stem cells. Additionally, MnOHo-Ab provides improved T1 MRI owing to the hollow structure of the MnOHo. Particularly, the anti-integrin β1 antibody (Ab) introduced in the MnOHo targets integrin β1 expressed in the entire stem cell lineage, enabling targeted monitoring regardless of the differentiation stage of the stem cells. Furthermore, we verified that intravenously injected MnOHo-Ab specifically targeted human induced pluripotent stem cells (hiPSCs) that were transferred to mice testes and differentiated into various lineages. The new stem cell monitoring method using MnOHo-Ab demonstrates whether the injected human stem cells have migrated and transplanted themselves in the target area during long-term stem cell regenerative therapy.
- Published
- 2020
50. Metal artifact reduction and tumor detection using photon-counting multi-energy computed tomography
- Author
-
Sangnam Nam, Min-Kook Cho, Yuna Choi, Kyoung-Yong Lee, Sang-Min Lee, Jiyoung Choi, Junyoung Park, and Chang-Lae Lee
- Subjects
Image quality ,Image Processing ,Contrast Media ,Diagnostic Radiology ,Neoplasms ,Image Processing, Computer-Assisted ,Medicine and Health Sciences ,Contrast (vision) ,Tomography ,media_common ,Multidisciplinary ,Phantoms, Imaging ,Radiology and Imaging ,Physics ,Detector ,Calcium Imaging ,Chemistry ,Oncology ,Metals ,Physical Sciences ,Medicine ,Radiographic Image Interpretation, Computer-Assisted ,Engineering and Technology ,Artifacts ,Algorithms ,Elementary Particles ,Research Article ,Chemical Elements ,Iodine ,Materials science ,Tomography Scanners, X-Ray Computed ,Imaging Techniques ,media_common.quotation_subject ,Science ,Image processing ,Neuroimaging ,Research and Analysis Methods ,Bin ,Imaging phantom ,Metal Artifact ,Diagnostic Medicine ,Humans ,Particle Physics ,Photons ,Biology and Life Sciences ,Cancers and Neoplasms ,equipment and supplies ,Photon counting ,Computed Axial Tomography ,Head and Neck Cancers ,Signal Processing ,Tomography, X-Ray Computed ,Head ,Biomedical engineering ,Neuroscience - Abstract
Metal artifacts are considered a major challenge in computed tomography (CT) as these adversely affect the diagnosis and treatment of patients. Several approaches have been developed to address this problem. The present study explored the clinical potential of a novel photon-counting detector (PCD) CT system in reducing metal artifacts in head CT scans. In particular, we studied the recovery of an oral tumor region located under metal artifacts after correction. Three energy thresholds were used to group data into three bins (bin 1: low-energy, bin 2: middle-energy, and bin 3: high-energy) in the prototype PCD CT system. Three types of physical phantoms were scanned on the prototype PCD CT system. First, we assessed the accuracy of iodine quantification using iodine phantoms at varying concentrations. Second, we evaluated the performance of material decomposition (MD) and virtual monochromatic images (VMIs) using a multi-energy CT phantom. Third, we designed an ATOM phantom with metal insertions to verify the effect of the proposed metal artifact reduction. In particular, we placed an insertion-mimicking an iodine-enhanced oral tumor in the beam path of metallic objects. Normalized metal artifact reduction (NMAR) was performed for each energy bin image, followed by an image-based MD and VMI reconstruction. Image quality was analyzed quantitatively by contrast-to-noise ratio (CNR) measurements. The results of iodine quantification showed a good match between the true and measured iodine concentrations. Furthermore, as expected, the contrast between iodine and the surrounding material was higher in bin 1 image than in bin 3 image. On the other hand, the bin 3 image of the ATOM phantom showed fewer metal artifacts than the bin 1 image because of the higher photon energy. The result of quantitative assessment demonstrated that the 40-keV VMI (CNR: 20.6 ± 1.2) with NMAR and MD remarkably increased the contrast of the iodine-enhanced region compared with that of the conventional images (CNR: 10.4 ± 0.5) having 30 to 140 keV energy levels. The PCD-based multi-energy CT imaging has immense potential to maximize the contrast of the target tissue and reduce metal artifacts simultaneously. We believe that it would open the door to novel applications for the diagnosis and treatment of several diseases.
- Published
- 2020
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.