Ewha Womans University
  • Seoul, South Korea
Recent publications
CTLA4-CD28 gene fusion has been reported to occur in diverse types of T cell lymphoma. The fusion event is expected to convert inhibitory signals to activating signals and promote proliferation and potentially transformation of T cells. To test the function of the CTLA4-CD28 fusion gene in vivo, we generated a murine model that expresses the gene in a T cell-specific manner. The transgenic mice have shorter life spans and display inflammatory responses including lymphadenopathy and splenomegaly. T cells in turn show higher levels of activation and infiltrate various organs including the lung and skin. T cells, in particular CD4+ helper T cells, were also readily transplantable to immunocompromised mice. Transcriptomic profiling revealed that the gene expression pattern in CD4 + T cells closely resembles that of adult T cell leukemia/lymphoma (ATLL) and that of angioimmunoblastic T cell lymphoma (AITL) tissues. Consistently, we detected supernumerary FOXP3+ cells and PD-1+ cells in transgenic and transplanted mice. This is the first report demonstrating the transforming activity of the CTLA4-CD28 fusion gene in vivo, and this murine model should be useful in dissecting the molecular events downstream to this mutation.
Chronic obstructive pulmonary disease (COPD) has been regarded as a disease of smokers, but the prevalence of non-smoking COPD patients have been reported to be considerable. We investigated differences in clinical characteristics between smoking and non-smoking COPD patients. We used data from the Korea COPD Subgroup Study (KOCOSS) database, which is a multicenter cohort that recruits patients from 54 medical centres in Korea. Comprehensive comparisons of smoking and non-smoking COPD patients were performed based on general characteristics, exacerbations, symptom scores, radiological findings, and lung-function tests. Of the 2477 patients included in the study, 8.1% were non-smokers and 91.9% were smokers. Non-smoking COPD patients were more likely to be female and to have a higher body mass index and lower level of education. Non-smoking COPD patients had more comorbidities, including hypertension, osteoporosis, and gastroesophageal reflux disease, and experienced more respiratory and allergic diseases. No significant differences in exacerbation rates, symptom scores, or exercise capacity scores were observed between the two groups. Smoking COPD patients had more emphysematous lung according to the radiological findings, and non-smoking patients had more tuberculosis-destroyed lung and bronchiectasis. Lung-function testing revealed no significant difference in the forced expiratory capacity in 1 sec between the two groups, but smokers had more rapid lung-function decline in the 5 years of follow-up data. We found differences in general characteristics and radiological findings between smoking and non-smoking COPD patients. No significant differences in exacerbation or symptom scores were observed, but decline in lung function was less steep in non-smoking patients.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2022.2053088 .
The local and global control results for a general higher-order KdV-type operator posed on the unit circle are presented. Using spectral analysis, we are able to prove local results, that is, the equation is locally controllable and exponentially stable. To extend the local results to the global one we captured the smoothing properties of the Bourgain spaces, the so-called propagation of singularities, which are proved with a new perspective. These propagation, together with the Strichartz estimates, are the key to extending the local control properties to the global one, precisely, higher-order KdV-type equations are globally controllable and exponentially stabilizable in the Sobolev space H s (T) for any s ≥ 0. Our results recover previous results in the literature for the KdV and Kawahara equations and extend, for a general higher-order operator of KdV-type, the Strichartz estimates as well as the propagation results, which are the main novelties of this work.
The deubiquitinating enzyme USP15 is implicated in several human cancers by regulating different cellular processes, including splicing regulation. However, the underlying molecular mechanisms of its functional relevance and the successive roles in enhanced tumorigenesis remain ambiguous. Here, we found that USP15 and its close paralog USP4 are overexpressed and facilitate lung cancer cell proliferation by regulating the alternative splicing of SRSF1. Depletion of USP15 and USP4 impair SRSF1 splicing characterized by the replacement of exon 4 with non-coding intron sequences retained at its C-terminus, resulting in an alternative isoform SRSF1-3. We observed an increased endogenous expression of SRSF1 in lung cancer cells as well, and its overexpression significantly enhanced cancer cell phenotype and rescued the depletion effect of USP15 and USP4. However, the alternatively spliced isoform SRSF1-3 was deficient in such aspects for its premature degradation through nonsense-mediated mRNA decay. The increased USP15 expression contributes to the lung adenocarcinoma (LUAD) development and shows significantly lower disease-specific survival of patients with USP15 alteration. In short, we identified USP15 and USP4 as key regulators of SRSF1 alternative splicing with altered functions, which may represent the novel prognostic biomarker as well as a potential target for LUAD.
Background The signs and symptoms of pheochromocytoma can imitate those of many other diseases, which may result in confusion. Therefore, diagnosing and treating secondary hypertension due to pheochromocytoma in deteriorating patients becomes challenging. Case presentation A 63-year-old female patient presented to the emergency room with severe and progressive nausea. The initial diagnosis was an acute myocardial infarction based on ST-segment depression on electrocardiogram and elevated cardiac markers. Elective coronary angiography revealed nonobstructive coronary arteries. However, she suffered from a complicated clinical course for several weeks during her life-or-death crisis. She was subsequently diagnosed with a cerebral hemorrhage and a pheochromocytoma. It is unclear whether her initial presentation was due to the neurogenic stunned myocardium caused by a cerebral hemorrhage or type 2 myocardial infarction caused by a pheochromocytoma, or both. However, this case showed the significance of accurately diagnosing and treating underlying causes in patients presenting with myocardial infarction with nonobstructive coronary arteries. Early diagnosis and treatment of the pheochromocytoma may have prevented the complications experienced by the patient. Conclusions A catecholamine surge and blood pressure fluctuation caused severe complications. When a patient presents with an unusual clinical presentation, secondary hypertension due to pheochromocytoma should be suspected.
Background Conventional modality requires several days observation by Holter monitor to differentiate atrial fibrillation (AF) between Paroxysmal atrial fibrillation (PAF) and Non-paroxysmal atrial fibrillation (Non-PAF). Rapid and practical differentiating approach is needed. Objective To develop a machine learning model that observes 10-s of standard 12-lead electrocardiograph (ECG) for real-time classification of AF between PAF versus Non-PAF. Methods In this multicenter, retrospective cohort study, the model training and cross-validation was performed on a dataset consisting of 741 patients enrolled from Severance Hospital, South Korea. For cross-institutional validation, the trained model was applied to an independent data set of 600 patients enrolled from Ewha University Hospital, South Korea. Lasso regression was applied to develop the model. Results In the primary analysis, the Area Under the Receiver Operating Characteristic Curve (AUC) on the test set for the model that predicted AF subtype only using ECG was 0.72 (95% CI 0.65–0.80). In the secondary analysis, AUC only using baseline characteristics was 0.53 (95% CI 0.45–0.61), while the model that employed both baseline characteristics and ECG parameters was 0.72 (95% CI 0.65–0.80). Moreover, the model that incorporated baseline characteristics, ECG, and Echocardiographic parameters achieved an AUC of 0.76 (95% CI 0.678–0.855) on the test set. Conclusions Our machine learning model using ECG has potential for automatic differentiation of AF between PAF versus Non-PAF achieving high accuracy. The inclusion of Echocardiographic parameters further increases model performance. Further studies are needed to clarify the next steps towards clinical translation of the proposed algorithm.
Layered group-IV monochalcogenides, including GeS, GeSe, SnS, and SnSe, garner attention because of their anisotropic structures and properties. Here, we report on the growth of GeS microribbons via chemical vapor transport (CVT), which affords each of them with a low-symmetry orthorhombic structure and anisotropic optical and electronic properties. The single-crystalline nature of the GeS microribbon, which has a typical thickness of~30 nm, is confirmed. Polarized Raman spectra reveal angle-dependent intensities that are attributed to the anisotropic layered structure of GeS microribbons. The photoluminescence (PL) spectra reveal a peak at~1.66 eV. The angle-dependent PL and anisotropic absorption spectroscopy results provide evidence for a distinct anisotropic optical transition near the energy band edges; this phenomenon is also predicted by our density functional theory (DFT)-based calculations. Strong in-plane direct-current transport anisotropy is observed under dark and white illumination by using back-gate cross-shaped field effect transistors (CSFETs) fabricated with the GeS microribbon; significant gate-tunable conductivity is also confirmed. The strong anisotropy is further confirmed by the DFT-calculated effective mass ratio. Our findings not only support the application of GeS microribbons in anisotropic photoelectronic transistors but also provide more possibilities for other functional device applications.
Objectives Ground-glass opacity (GGO) on computed tomography is associated with prognosis in early-stage non-small cell lung cancer (NSCLC) patients. However, the stratification of the prognostic value of GGO is controversial. We aimed to evaluate clinicopathologic characteristics of early-stage NSCLC based on the consolidation-to-tumor ratio (CTR), conduct multi-pronged analysis, and stratify prognosis accordingly. Methods We retrospectively investigated 944 patients with clinical stage IA NSCLC, who underwent curative-intent lung resection between August 2018 and January 2020. The CTR was measured and used to categorize patients into six groups (1, 0%; 2, 0–25%; 3, 25–50%; 4, 50–75%; 5, 75–100%; and 6, 100%). Results Pathologic nodal upstaging was found in 1.8% (group 4), 9.0% (group 5), and 17.4% (group 6), respectively. The proportion of patients with a high grade of tumor-infiltrating lymphocytes tended to decrease as the CTR increased. In a subtype analysis of patients with adenocarcinoma, all of the patients with predominant micro-papillary patterns were in the CTR > 50% groups, and most of the patients with predominant solid patterns were in group 6 (47/50, 94%). The multivariate analysis demonstrated that CTR 75–100% (hazard ratio [HR], 3.85; 95% confidence interval [CI], 1.58–9.36) and CTR 100% (HR, 5.58; 95% CI, 2.45–12.72) were independent prognostic factors for DFS, regardless of tumor size. Conclusion We demonstrated that the CTR could provide various noninvasive clinicopathological information. A CTR of more than 75% is the factor associated with a poor prognosis and should be considered when making therapeutic plans for patients with early-stage NSCLC.
Practical lithium–oxygen batteries require a shift from pure O2 to air. CO2 traces, however, fundamentally alter the O2 electrochemistry towards Li2CO3 formation via peroxocarbonate intermediates in highly-solvating electrolytes e.g., tetraethylene glycol dimethyl ether (G4). Here, we reveal that operating temperatures (0∼70 °C) critically dictate Li2CO3-associated cell overcharges (4.60∼3.77 V), by determining temperature-dependent reaction kinetics and evolving species mobility, as analogously witnessed under pure O2-conditions. Against what is observed for Li2O2 formation in the Li–O2 cell, however, cell temperatures do not govern the crystallinity of the Li2CO3 discharge product. In agreement with experimental observations, comprehensive density functional theory calculations also uncover the effect of the temperature on the Li2CO3 precipitation mechanism and shed light on the dwindling stabilization of metastable peroxocarbonate intermediates during discharge at increasing cycling temperatures. On the other hand, during extended operation, the temperature-dependent reactants mobility in the viscous G4 electrolyte and remnant Li-deficient carbonate surfaces from precedent recharge steps play equally prominent roles on the Li2CO3 precipitation mechanism and the resulting cell capacity. Our study highlights the complexity of practical Li–O2 cells with temperature-dependent performances.
The purpose of this study is to investigate the effect of fire-damaged areas associated with wall width on the axial strength of fire-damaged reinforced concrete (RC) walls. Toward that goal, Finite Element (FE) models of RC walls in real scale are generated with various wall widths of (600, 1500, and 3000) mm and number of heated surfaces such as half-surface, single-surface and double-surfaces. For the analyses, experiments are used to obtain temperature distributions inside the walls depending on the fire-damaged areas, and to validate the FE models. The analytical results show that the axial strength of the fire-damaged wall increases linearly with the wall width, except that the ratios of axial force to wall width showed slightly off from the average for the case of walls heated on half of the surface. Using the axial strength data of fire-damaged concrete walls obtained from the current and previous studies, regression analysis is conducted to estimate axial strength reduction ratios of fire-damaged concrete walls, considering various influencing parameters, such as concrete strength, fire-damaged areas, wall width and height. As a conclusion, multiple linear regression formulations from the regressions analyses are able to estimate axial strength reduction ratios of the fire-damaged concrete walls considering various influencing parameters of the wall size, concrete strength and fire-damaged area and the estimations showed good agreements with the data collected from experiments and FE analyses.
To prepare measures for washing synthetic fibers, which cause proliferation of microplastics in the marine ecosystem, a fundamental analysis is required. Therefore, this study established an efficient method for quantitatively analyzing microfibers using artificial neural networks, comparing the amounts of microfibers generated in the manufacturing, wearing, and washing processes of clothing. The proportion of microfiber emitted during the manufacturing process was the largest (49%), followed by that emitted during the washing (28%) and wearing (23%) processes. This suggests that minimizing the amount of microfiber emitted during the manufacturing process is key to solving microfiber issues in the fashion industry. Additionally, during the wearing process, the amount of waterborne microfiber detected in washing was slightly larger than the amount of airborne microfiber. In the washing process, the washing temperature did not significantly affect microfiber emissions. However, when reducing the amount of water used or increasing the number of washings, microfiber emissions increased noticeably due to the greater friction applied to clothes. A common result of all experiments was that the largest proportion of microfibers was released during the first five washing cycles. Therefore, before wearing new items, consumers can minimize microfiber release by pre-washing using a laundry bag that filters microfibers. Furthermore, the most effective way to minimize microfibers is to eliminate them from the manufacturing process before they are distributed to consumers.
To improve the thermostability of Thermomyces lanuginosus lipase (TLL) which has been widely used in biodiesel production, molecular dynamics (MD) simulation was applied to find the fluctuation regions under different temperatures. In silico mutation prediction was also applied to calculate the mutation stability of amino acid residues for site mutagenesis. Six mutants were predicted and subjected to mutagenesis and expressed in Pichia pastoris KM71H. The enzyme activity of G91C not only increased by 53.8%, but also enhanced the residual activity by about 25 ∼ 45% in thermostability. With 5 °C higher than that of the wild type in optimal temperature, the catalytic efficiency of G91C was also increased by 1.3 times. The fatty acid methyl esters (FAME) yield catalyzed by G91C was as high as 91% at 43 °C, 7% higher than that of the WT during the transesterification of Cornus wilsoniana oil to biodiesel. According to the structural comparisons, it was found that there was an extra main-side hydrogen bond between Cys91 and Glu87 separated by four amino acid residues and a more stable α-helix was obtained, which may be the key factor in the thermostability enhancement. In total, the engineered G91C mutant showed great potential in the production of biodiesel at high temperature.
Surgical intervention after traumatic peripheral nerve injury relies heavily on sutures. While the suture method often burdens functional nerve regeneration by causing secondary traumatic damage and eliciting prolonged inflammatory immune responses, replacing sutures has rarely been considered because secure anastomosis between severed nerve ends has been the utmost priority in neurorrhaphy. In the present work, a macrophage-polarizing sutureless neurorrhaphy system was proposed by using an in situ visible light-crosslinkable protein-based bioadhesive hydrogel containing a functional neurotransmitter peptide. The efficacy of the proposed bioadhesive hydrogel as a successful sutureless neurorrhaphy system was intensively evaluated in vitro and in vivo. Using a rat sciatic nerve defect model, our findings suggested that this macrophage-polarizing bioadhesive hydrogel offered effective sutureless anastomosis and the capability to induce M2 macrophage polarization for effective tissue remodeling, significantly enhancing functional nerve regeneration compared with conventional sutures. Taken together, these results suggest that our macrophage-polarizing functional bioadhesive hydrogel system can be utilized as a promising alternative to surgical sutures for nerve regenerative medicine applications.
Cyclometalated Ir(III) complexes exhibit strong phosphorescence emission with lifetime of submicroseconds to several microseconds at room temperature. Their synthetic versatility enables broad control of physical properties, such as charge and lipophilicity, as well as emission colors. These favorable properties have motivated the use of Ir(III) complexes in luminescent bioimaging applications. This review examines the recent progress in the development of phosphorescent biolabels and sensors based on Ir(III) complexes. It begins with a brief introduction about the basic principles of the syntheses and photophysical processes of cyclometalated Ir(III) complexes. Focus is placed on illustrating the broad imaging utility of Ir(III) complexes. Phosphorescent labels illuminating intracellular organelles, including mitochondria, lysosomes, and cell membranes, are summarized. Ir(III) complexes capable of visualization of tumor spheroids and parasites are also introduced. Facile chemical modification of the cyclometalating ligands endows the Ir(III) complexes with strong sensing ability. Sensors of temperature, pH, CO2, metal ions, anions, biosulfur species, reactive oxygen species, peptides, and viscosity have recently been added to the molecular imaging tools. This diverse utility demonstrates the potential of phosphorescent Ir(III) complexes toward bioimaging applications.
In this study, we integrate insights from the literature on top management team (TMT) composition, gender diversity, and cumulative innovation, and examine how TMT gender diversity (or women in TMTs) impacts firm innovation. We analyze a panel of U.S. firms over the period 2005–2019, exploiting U.S. state-level variation in support policies protecting the rights of female workers. We find that greater TMT gender diversity increases the number of innovations but decreases their impact. Furthermore, greater TMT gender diversity narrows the breadth of search (search becomes more local). We illuminate the multifaceted innovation outcomes of gender-diverse TMTs and highlight the risk-reducing effects of female TMT members in innovation contexts. Our study provides opportune innovation insights that are much needed in the current era, with the increasing presence of female executives in TMTs.
A hybrid preventive maintenance policy for heterogeneous degrading items is discussed. It combines the classical age-replacement strategy, when a system is replaced either on failure or at the predetermined age, with replacement of the system when degradation reaches the predetermined level at some intermediate time. Items come from two subpopulations with different reliability characteristics. Non-homogeneous gamma processes model degradation of an item from each subpopulation. We justify probabilistically the superiority of the proposed policy over that for homogeneous populations and over the policy without possibility of additional replacement. The corresponding long-run cost rate is derived for the suggested cost structure. Some detailed numerical illustrations are presented and relevant sensitivity analysis for the main parameters of the model is performed.
Traditionally, in reliability acceptance sampling plans, the decision to accept or reject a lot is made by performing the life tests of items. However, when the item’s deterioration is described by a degradation process, it can be made based on the observed deterioration levels of the items obtained from degradation tests. In this paper, two acceptance sampling plans are developed, based on the observation of the deterioration of the items, accumulated on a given period of time. To model the degradation of the items over time, the Wiener process with positive drift is employed. Algorithms to find the parameters of the proposed sampling plans are suggested. Conditionally on the acceptance in the test, the developed sampling plans are shown to improve the reliability performance of the items in the sense that the lifetimes of the items after the reliability sampling test are stochastically larger than those before the test. Also, we compare the two sampling plans both from a technical and economical points of view.
In this paper, we describe a result on self-conjugate (s,s+1)-core partitions with the fixed number of corners. We also define shifted corners of a distinct partition and find formulas for the number of (s‾,s+1‾)-core partitions and the number of (s,s+1)-core shifted Young diagrams with the fixed number of shifted corners.
To understand the development of cyber aggression during adolescence, it is important to consider the temporal variability of its potential predictors. This study uses a four-wave survey to investigate how changes in peer norms, parental norms, and parental communication are associated with two-year trajectories of online peer aggression. The sample includes 1521 Swiss middle school students (M age T1 = 11.54, SD = 0.40; 48% female). The results showed that over time a better parental communication quality and anti-aggression norms predicted lower rates and slower development of cyber aggression. Moreover, parental variables emerged as a quite stable deterrent of aggressive conduct. Although entrance into adolescence is characterized by the rise of peer influence, results from this study suggest that parents maintain an important protective role.
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3,874 members
Kye-Il Joo
  • Division of Chemical Engineering and Materials Science
Shaherin Basith
  • College of Pharmacy
Jongserl Chun
  • Social Work
Kyung-Suk Cho
  • Department of Environmental Science and Engineering
Dong-Wook Kim
  • Department of Physics
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