Gachon University
  • Seongnam-si, Gyeonggi-do, South Korea
Recent publications
Fully automated vehicles collect information about their road environments to adjust their driving actions, such as braking and slowing down. The development of artificial intelligence (AI) and the Internet of Things (IoT) has improved the cognitive abilities of vehicles, allowing them to detect traffic signs, pedestrians, and obstacles for increasing the intelligence of these transportation systems. Three-dimensional (3D) object detection in front-view images taken by vehicle cameras is important for both object detection and depth estimation. In this paper, a joint channel attention and multidimensional regression loss method for 3D object detection in automated vehicles (called CAMRL) is proposed to improve the average precision of 3D object detection by focusing on the model’s ability to infer the locations and sizes of objects. First, channel attention is introduced to effectively learn the yaw angles from the road images captured by vehicle cameras. Second, a multidimensional regression loss algorithm is designed to further optimize the size and position parameters during the training process. Third, the intrinsic parameters of the camera and the depth estimate of the model are combined to reduce the object depth computation error, allowing us to calculate the distance between an object and the camera after the object’s size is confirmed. As a result, objects are detected, and their depth estimations are validated. Then, the vehicle can determine when and how to stop if an object is nearby. Finally, experiments conducted on the KITTI dataset demonstrate that our method is effective and performs better than other baseline methods, especially in terms of 3D object detection and bird’s-eye view (BEV) evaluation.
Infectious respiratory diseases such as COVID-19 are serious and global concerns from the past to the present. To isolate the spread of infectious diseases even in the absence of a health system, a simple, inexpensive, reliable, sensitive, and selective molecular diagnosis platform for Point of Care Test (POCT) is required. Especially, the nucleic acid extraction step is difficult to perform out of laboratory. Here, we propose a paper-based lysis (PBL) strip for nucleic acid extraction, especially in low-resource settings (LRS). PBL strips are suitable for isolating RNA from viruses with biological interference and inhibitors. We optimized the buffer compositions and membranes of the strip. A simple preparation method using a PBL strip could obtain an eluent for downstream inspection within 20 minutes. Overall, 104 copies/swaps were detected for 20 minutes for amplification in combination with Reverse Transcription Loop-Mediated Amplification (RT-LAMP).
Acral melanoma (AM), a rare subtype of cutaneous melanoma, shows higher incidence in Asians, including Koreans, than in Caucasians. However, the genetic modification associated with AM in Koreans is not well known and has not been comprehensively investigated in terms of oncogenic signaling, and hallmarks of cancer. We performed whole-exome and RNA sequencing for Korean patients with AM and acquired the genetic alterations and gene expression profiles. KIT alterations (previously known to be recurrent alterations in AM) and CDK4/CCND1 copy number amplifications were identified in the patients. Genetic and transcriptomic alterations in patients with AM were functionally converge to the hallmarks of cancer and oncogenic pathways, including 'proliferative signal persistence', 'apoptotic resistance', and 'activation of invasion and metastasis', despite the heterogeneous somatic mutation profiles of Korean patients with AM. This study may provide a molecular understanding for therapeutic strategy for AM.
Purpose Previous reports showed that some probiotics provide beneficial effects on various diseases including metabolic disorders. This study aimed to investigate the anti-obesity effects of Lactiplantibacillus (L.) plantarum SKO-001 (SKO-001), a probiotic strain newly isolated from Angelica gigas. Methods C57BL/6J mice were fed with high-fat diet (HFD, 60% fat) for four weeks, and then different doses of SKO-001 (n = 10 each group) were orally given for 12 weeks. Following treatment, body weight, fat weight, serum parameters and adipose and liver tissues were analyzed. Results SKO-001 (2 × 10¹⁰ CFU/day, per os) reduced body weight gain after 10th week of administration, accompanied by a reduction in body fat mass of mice. In the SKO-001-fed group, increased serum adiponectin, decreased leptin, insulin, total cholesterol, low-density lipoprotein cholesterol, free fatty acids, and triglyceride levels were observed. Hematoxylin and eosin staining of various fat depots showed that increased adipocyte size caused by HFD intake was markedly reduced and correlated with reduced mRNA levels of lipogenesis genes, including sterol regulatory element-binding protein-1c, peroxisome proliferator-activated receptor gamma, and CCAAT/enhancer binding protein alpha, and increased uncoupling protein 1 levels. Similarly, SKO-001 reduced lipid accumulation, decreased the mRNA levels of lipogenic genes, and reduced α-smooth muscle actin and collagen type 1 alpha 1 levels in the liver. Conclusions SKO-001 ameliorates obesity and related metabolic abnormalities in adipose and liver tissues, possibly via the regulation of lipid metabolism. Based on the results of the present study, SKO-001 may be applicable as an anti-obesity therapeutic or functional food.
Objective: Modular workcells could be a better solution than total laboratory automation (TLA) in hemostasis laboratories. Here, we evaluated the impact of implementing a modular workcell (HemoCell) with an intelligent data management facility (HemoHub). Methods: We compared the turnaround times (TATs), numbers of rerun samples, and rerun times pre- and postimplementation of the HemoCell at Gil Medical Center. Prothrombin time (PT), activated partial thromboplastin time (aPTT), D-dimer, and fibrinogen were evaluated. Results: The TAT standard deviations (SDs) and maximum TAT values decreased after HemoCell implementation, although the mean TATs for PT, aPTT, and D-dimer were increased. Numbers of rerun samples were increased (18.1/day vs 44.7/day). However, rerun times were reduced, and SDs were decreased during the post-HemoCell period compared with pre-HemoCell. Additionally, technologists needed smaller working space and less labor. Conclusion: The modular workcell could improve quality and efficiency by providing more consistent TATs and shorter rerun times in the hemostasis laboratory.
The liver partakes as a sensor and effector of peripheral metabolic changes and a regulator of systemic blood and nutrient circulation. As such, abnormalities arising from liver dysfunction can influence the brain in multiple ways, owing to direct and indirect bilateral communication between the liver and the brain. Interestingly, altered bile acid composition resulting from perturbed liver cholesterol metabolism influences systemic inflammatory responses, blood-brain barrier permeability, and neuron synaptic functions. Furthermore, bile acids produced by specific bacterial species may provide a causal link between dysregulated gut flora and neurodegenerative disease pathology through the gut-brain axis. This review will cover the role of bile acids—an often-overlooked category of active metabolites—in the development of neurological disorders associated with neurodegeneration. Further studies into bile acid signaling in the brain may provide insights into novel treatments against neurological disorders.
Low-dimensional nanomaterials with various functionalities are highly promising materials for transparent electrodes which are key components of electronic and optoelectronic devices. However, conventional physical vapor deposition (PVD) methods are not applicable to low-dimensional nanomaterials because of the harsh vaporizing conditions, and using solution processing technologies as alternatives is attracting attention. Herein, we demonstrate a facile method for fabricating of multifunctional transparent electrodes via one-step spray deposition of indium-tin-oxide (ITO) nanoparticles. In this method, ITO nanoparticles are spontaneously and rapidly packed, forming electrically conductive thin films composed of random nanostructures. This method can be adapted to fabricating hierarchical structures, that is, micropatterns consisting of random nanostructures, using impermeable shadow masks. In addition, the optical and electrochemical properties of the spray-deposited ITO films were investigated to confirm their high transmission haze values and ion-storage capabilities, leading to further applications such as random scattering layers, transparent superconductors, and high-performance electrochromic devices. We expect these results to spur the development and refinement of multifunctional electrodes and their electronic and optoelectronic applications.
Alzheimer’s disease (AD) is the most common dementia characterized by the excessive accumulation of amyloid-beta (Aβ) and tau aggregates, as well as neuronal damage and neuroinflammation. Metabolic disruption in AD has been noticed because metabolite alterations closely correlate with Aβ neuropathology and behavioral phenotypes. Accordingly, controlling various neuropathological processes and metabolic disruption is an efficient therapeutic strategy for AD treatment. In this study, we evaluated the effects of a combination of Cuscuta seeds and Lactobacillus paracasei NK112 (CCL01) on AD neuropathology and altered metabolism in five familial AD (5xFAD) transgenic mice and neuronal cell cultures. First, we observed that CCL01 exerted neuroprotective effects in HT22 hippocampal neurons and primary cultured neurons. CCL01 ameliorated memory decline and protected synapses and neuronal survival in 5xFAD mice. These effects were related to the inhibition of tau phosphorylation. CCL01 also inhibited the activation of mitogen-activated protein kinase (MAPK) signaling and neuroinflammatory processes. Moreover, the metabolite profile—particularly characterized by altered phospholipid metabolism—was significantly changed in the 5xFAD group, while CCL01 partly restored the alteration. Lysophosphatidylcholine (lysoPC), the levels of which were higher in the brains of 5xFAD mice, exerted neurotoxicity in vitro, whereas CCL01 protected neurons from lysoPC-induced toxicity by regulating MAPK signaling. Additionally, CCL01 administration reduced gut inflammation in the 5xFAD mice. In summary, we demonstrated that CCL01 improved the memory function of 5xFAD mice by protecting neurons against Aβ- and lysoPC-induced toxicity through the regulation of MAPK signaling, neuroinflammation, tau phosphorylation, and gut inflammation, suggesting the potential of CCL01 as treatment for AD.
Rapid screening of individuals infected with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is necessary to contain contagion in a large population. Nucleic acid-based gold standard assays are time-consuming, and nucleic acid amplification is mandatory and expensive, impeding the containment of the coronavirus disease 2019 (COVID-19) outbreak. To overcome the aforementioned disadvantages, this study deals with a specially designed gold (Au)-deoxyribonucleic acid (DNA)-cadmium telluride (CdTe) quantum dot (QD) probe to target two sections of the nucleocapsid (N) gene of SARS-CoV-2 ribonucleic acid (RNA) of three variants (B.1.1.529, B.1.617.2, and B.1.351). A duplex-specific nuclease (DSN)-assisted highly selective release of signaling probes enable higher specificity, and an Au-supported DNA probe is incorporated to carry many CdTe QD signaling probes. After dissolution, the generated Cd2+ ions are quantified at the novel cobalt sulfide (CoS)-nitrogen-doped graphene QD (NGQD)/platinum (Pt)@palladium (Pd) electrode with extraordinary sensitivity through square wave anodic stripping voltammetry (SWASV). The developed sensor exhibits a wide range of detection (10 to 108 copies µL−1) and a lower detection limit (0.12 copies µL−1), without any amplification. The selectivity of the sensor is tested against MERS and HCoV-NL63, and real-time detection is performed on heat-inactivated viral samples, which show excellent selectivity.
Protozoan-borne diseases are major drivers of global morbidities and mortalities, especially in developing countries. These diseases pose a unique challenge to effective treatment strategies, thereby contributing to significant death. Current treatment approaches have low efficacy, high toxicity and side effects of therapeutic doses and therefore generate a need for alternative new treatment approaches. Nanotechnology-based drug delivery systems have evolved as a new and promising approach to therapy and prevention of protozoan-associated infectious diseases. The formulation of new drugs and drugs’ carriers using nano-sized particles including exosomes, liposomes, solid lipid nanoparticles, dendrimers and nano-vaccines promises to overcome the limitations of low bioavailability, low toxicity, sub-therapeutic drug accumulation in microbial sanctuaries and reservoirs and low patient adherence due to drug-related toxicities and extended therapeutic regimens. Nanotechnology-based therapeutic approaches offer an important weapon in the fight against infectious protozoan diseases.
Gamma-glutamyl transpeptidase is an enzyme that facilitates the transfer of glutamyl groups from glutamyl peptides to other peptides or water. Additionally, it also participates in important processes such as amino acid transport, cellular redox control, drug detoxification, apoptosis, and DNA fragmentation in a various organism. In the present study, GGT activity in Gigantocotyle explanatum was examined in order to characterize the enzyme in the helminth system. GGT is isolated using membrane solubilization and purified through affinity column chromatography (Con-A Sepharose column). Km and Vmax values, as well as the optimal pH, optimal temperature, and incubation period, are also determined using enzyme kinetics. The hetero-dimeric property of the enzyme is demonstrated by the purified GGT, which yielded two subunits of 65.5 and 55 kDa. The optimal pH and temperature are found to be 8.0 and 37 °C, respectively. While assessing the optimal incubation time of the enzyme, it was observed that the purified GGT not only retained its functional integrity up to 15 min but also reflected considerable thermostability at higher temperatures, by retaining 78% and 25% of its initial activities at 50 °C and 60 °C, respectively. One millimolar concentration of 6-Diazo-5-Oxo Nor-isoleucine (DON), a specific inhibitor of GGT, completely abolished GGT activity. These results suggest that GGT in these worms is a catalytically active enzyme with distinguishing characteristics that can be used for further study to comprehend its function in amphistome biology and in host-parasite relationships, especially since the potential therapeutic candidacy of the GGT enzyme has already been indicated in these groups of organisms.
Crohn's disease is a chronic inflammatory disease that may occur in the alimentary tract and has various clinical courses. It is characterized by several complications, including bowel strictures, bowel obstruction, fistulas, abscesses, and hydronephroureterosis. Each complication is related to adjacent bowel involvement in Crohn's disease, and other complications can require surgical or interventional treatment. Patients with Crohn's disease who develop intra-abdominal abscess tend to suffer from recurrent intra-abdominal abscess during the follow-up period. Intra-abdominal abscess can often develop at the fistula site. Bowel stricture due to Crohn's disease leads to bowel obstruction. Radiologic examinations, such as computed tomography and magnetic resonance imaging, play an essential role in evaluating disease severity and complications in patients with Crohn's disease.
Pancreatic β-cells produce and secrete insulin to maintain blood glucose levels within a narrow range. Defects in the function and mass of β-cells play a significant role in the development and progression of diabetes. Increased β-cell deficiency and β-cell apoptosis are observed in the pancreatic islets of patients with type 2 diabetes. At an early stage, β-cells adapt to insulin resistance, and their insulin secretion increases, but they eventually become exhausted, and the β-cell mass decreases. Various causal factors, such as high glucose, free fatty acids, inflammatory cytokines, and islet amyloid polypeptides, contribute to the impairment of β-cell function. Therefore, the maintenance of β-cell function is a logical approach for the treatment and prevention of diabetes. In this review, we provide an overview of the role of these risk factors in pancreatic β-cell loss and the associated mechanisms. A better understanding of the molecular mechanisms underlying pancreatic β-cell loss will provide an opportunity to identify novel therapeutic targets for type 2 diabetes.
Amid the rapid development of electric vehicles, a flexible and waterproof radiant heater that can withstand repeated bending and washing is highly desirable. Herein, a freestanding, ultra‐flexible, and washable joule heater is constructed using a biocompatible poly(styrene‐isoprene‐styrene) (SIBS) polymer as binder and carbon black (CB) as heating material. By controlling the amount of CB and the thickness of the film, a minimum resistivity, and conductivity of 26 mΩ cm and 7.4 S cm−1, respectively, is achieved. Remarkably, the 28% CB/SIBS film can reach a maximum temperature of 201 °C while maintaining a stable temperature at 130 °C for repeated ON/OFF cycles. Time‐of‐flight secondary ion mass spectrometry of post‐mortem material analysis shows that a 1 h stability test at 130 °C has no sign of degradation and the films remain extremely stable. The films also show exceptional electrothermal heater performance after carrying out mechanical property tests such as bending (over 30°), repetitive bending (1000 cycles), twisting (two turns), and washing (soaked in distilled water for over 12 h). These outstanding heater performances incorporate extreme chemical stability and mechanical flexibility proposing that the CB/SIBS‐based electrothermal elements hold great potential for numerous practical applications, such as heating systems in electric vehicles and wearable electronics. The uptake of electric vehicles (EVs) around the world is driving global demand for lithium‐ion batteries. The EVs of today suffer from key limitations in colder climates—the batteries discharge extremely quickly, resulting in significant reduced mileage. The present investigation develops an advanced carbon incorporated polymer matrix for washable, twistable, and stretchable electrothermal heaters with significantly less battery power consumption.
Background: Oxiracetam may have a modest effect on preventing cognitive decline. Exercise can also enhance cognitive function. This trial aims to investigate the effect of oxiracetam on post-stroke cognitive impairment and explore whether this effect is modified by exercise. Furthermore, the mechanisms that mediate this effect will be investigated through a neural network analysis. Methods: This is a multicenter, randomized, double-blind, placebo-controlled phase IV trial. Patients who complained of cognitive decline 3 months after stroke and had a high risk of cognitive decline were eligible. Patients were randomly assigned to receive either 800 mg of oxiracetam or placebo twice daily for 36 weeks. After randomization, a predetermined exercise protocol was provided to each participant, and the degree of physical activity was assessed using wrist actigraphy at 4, 12, 24, and 36 weeks. Resting-state functional MRI was obtained in baseline and 36-week follow-up. Co-primary endpoints are changes in the Mini-Mental State Examination and Clinical Dementia Rating-Sum of Boxes. Secondary endpoints include changes in the NINDS-CSN VCIHS-Neuropsychology Protocol, Euro QoL, patient's global assessment, and functional network connectivity. If there is a significant difference in physical activity between the two groups, the interaction effect between physical activity and the treatment group will be examined. A total of 500 patients were enrolled from February 2018, and the last patient's final follow-up was completed in September 2022. Conclusion: This trial is meaningful not only to prove the efficacy of oxiracetam, but also evaluate whether exercise can modify the effects of medication and how cognitive function can be restored. Trial registration (KCT0005137).
Polyp segmentation is challenging because the boundary between polyps and mucosa is ambiguous. Several models have considered the use of attention mechanisms to solve this problem. However, these models use only finite information obtained from a single type of attention. We propose a new dual-attention network based on shallow and reverse attention modules for colon polys segmentation called SRaNet. The shallow attention mechanism removes background noise while emphasizing the locality by focusing on the foreground. In contrast, reverse attention helps distinguish the boundary between polyps and mucous membranes more clearly by focusing on the background. The two attention mechanisms are adaptively fused using a “Softmax Gate”. Combining the two types of attention enables the model to capture complementary foreground and boundary features. Therefore, the proposed model predicts the boundaries of polyps more accurately than other models. We present the results of extensive experiments on polyp benchmarks to show that the proposed method outperforms existing models on both seen and unseen data. Furthermore, the results show that the proposed dual attention module increases the explainability of the model.
We explored the perceptions of individuals in teams (both leaders and members) regarding shared leadership in the South Korean business context, seeking a nuanced and unique understanding of shared leadership. We examined how shared leadership in team‐based structures develops and functions. Informed by the driving and restraining forces framework, we elucidate factors that facilitate and that impede shared leadership practice and implementation. The analysis uses semi‐structured interviews with seven teams that each consist of one team leader and two team members. Findings include the four essential elements of shared leadership and the identification of the driving and restraining forces for why employees and managers welcome or refuse to accept shared leadership. We present strategies for human resource development (HRD) professionals seeking to cultivate shared leadership in the South Korean context. We also discuss the study's limitations and potential directions of inquiry for future researchers.
IntroductionDuring the Vietnam War, several unknown chemicals, such as Agent Orange, were used in Vietnam by the military. Therefore, there have been continuous health concerns among the Vietnamese population and veterans exposed to these hazardous chemicals. This study aimed to investigate the risk of all cancers and also organ-specific cancers among Korean veterans of the Vietnam War.Methods This study used a national representative cohort that included all Korean Vietnam War veterans as the interest group, with 1:4 age-sex-region-matched general Korean citizens as the reference group, from 2002 to 2018. Age-standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated for all cancers and for 31 organ-specific cancer categories based on the medical facility visit data.ResultsAn increased SIR of 1.07 (95% CI, 1.06–1.08) was observed for all cancers among the veterans. There was a significantly increased risk of cancer among 22/31 organspecific cancers, with 18 cancer categories showing a significantly higher risk than all cancers. The highest risk was observed for “malignant neoplasms of other parts of the central nervous system” (SIR, 1.71; 95% CI, 1.51–1.92).DiscussionThis study evaluated the risk of cancer among Korean Vietnam War veterans. Further studies are warranted to investigate various health determinants in the veterans as well as the Vietnamese population.
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1,518 members
Jae Hoon Lee
  • Department of Hemato-oncology
Gautam Das
  • Department of Chemical and Biological Engineering
Sang Pyo Lee
  • Department of Internal Medicine
Kumud Tripathi
  • Department of BioNano Technology
1342 Sungnam Daero, Sujung-gu, 461-701, Seongnam-si, Gyeonggi-do, South Korea
Head of institution
Gil-yeo Lee