Publications by authors named "Kyung Ahn"

Refractoriness to initial chemotherapy and relapse after remission are the main obstacles to curing T cell acute lymphoblastic leukemia (T-ALL). While tumor heterogeneity has been implicated in treatment failure, the cellular and genetic factors contributing to resistance and relapse remain unknown. Here we linked tumor subpopulations with clinical outcome, created an atlas of healthy pediatric hematopoiesis and applied single-cell multiomic analysis to a diverse cohort of 40 T-ALL cases.

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Galactic cosmic radiation (GCR) is an unavoidable risk to astronauts that may affect mission success. Male rodents exposed to 33-beam-GCR (33-GCR) show short-term cognitive deficits but reports on female rodents and long-term assessment are lacking. We asked: What are the longitudinal behavioral effects of 33-GCR on female mice? Also, can an antioxidant/anti-inflammatory compound (CDDO-EA) mitigate the impact of 33-GCR? Mature (6-month-old) C57BL/6J female mice received CDDO-EA (400 μg/g of food) or a control diet (vehicle, Veh) for 5 days and Sham-irradiation (IRR) or whole-body 33-GCR (0.

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Article Synopsis
  • The size and shape of graphite are crucial for the performance of lithium-ion batteries and affect the manufacturing of electrode slurries.
  • A novel method was developed to accurately characterize graphite particles' edge size and shape by aligning them through a specific flow field in a microchannel.
  • The study reveals that ball-milled graphite has a different shape compared to natural graphite, which impacts the rheological properties of slurries, electrode structures, and ultimately the electrochemical performance of the batteries.
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 The greater the viscosity of the blood, the more difficult its flow becomes, leading to an increased incidence of diseases caused by blood circulation disorders. These diseases are commonly associated with the cardiovascular and cerebrovascular systems. High blood viscosity is a primary cause of circulatory system diseases.

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Non-hematopoietic cells are essential contributors to hematopoiesis. However, heterogeneity and spatial organization of these cells in human bone marrow remain largely uncharacterized. We used single-cell RNA sequencing (scRNA-seq) to profile 29,325 non-hematopoietic cells and discovered nine transcriptionally distinct subtypes.

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Article Synopsis
  • The bone marrow is crucial for blood production, with non-hematopoietic cells playing key roles, yet their organization in humans has been underexplored due to technical difficulties.
  • Using advanced techniques like single-cell RNA sequencing, researchers characterized 29,325 bone marrow cells and identified nine distinct cellular subtypes.
  • Their findings revealed specific niches for cell development in healthy and leukemia-affected samples, providing a detailed multiomic atlas of human bone marrow that can aid future studies on blood cell formation and interactions.
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Pediatric high-grade glioma (pHGG) is an incurable central nervous system malignancy that is a leading cause of pediatric cancer death. While pHGG shares many similarities to adult glioma, it is increasingly recognized as a molecularly distinct, yet highly heterogeneous disease. In this study, we longitudinally profiled a molecularly diverse cohort of 16 pHGG patients before and after standard therapy through single-nucleus RNA and ATAC sequencing, whole-genome sequencing, and CODEX spatial proteomics to capture the evolution of the tumor microenvironment during progression following treatment.

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  • The study investigates how blood viscosity affects stroke outcomes and its clinical usefulness when measured at hospital arrival.
  • Among 112 patients suspected of having a stroke, blood viscosity was significantly higher in those with ischemic stroke compared to those diagnosed with stroke mimics.
  • The findings suggest that measuring blood viscosity can help differentiate ischemic stroke from other conditions, as it correlates with different shear rates at various frequencies.
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The initiation and progression of cancer are intricately linked to the tumor microenvironment (TME). Understanding the function of specific cancer-TME interactions poses a major challenge due in part to the complexity of the in vivo microenvironment. Here we predict cancer-TME interactions from single cell transcriptomic maps of both human colorectal cancers (CRCs) and mouse CRC models, ask how these interactions are altered in human tumor organoid (tumoroid) cultures, and functionally recapitulate human myeloid-carcinoma interactions in vitro.

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Refractoriness to initial chemotherapy and relapse after remission are the main obstacles to cure in T-cell Acute Lymphoblastic Leukemia (T-ALL). Biomarker guided risk stratification and targeted therapy have the potential to improve outcomes in high-risk T-ALL; however, cellular and genetic factors contributing to treatment resistance remain unknown. Previous bulk genomic studies in T-ALL have implicated tumor heterogeneity as an unexplored mechanism for treatment failure.

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Article Synopsis
  • The text discusses the potential of using microbial metabolism to convert sunlight and organic carbon into sustainable energy, highlighting the current limitations in developing effective microbial platforms for fuel production.
  • A new microbial device inspired by water lily leaves is introduced, which functions at the air-water interface, enhancing the supply and capture of gases while optimizing sunlight delivery.
  • The device, utilizing the microorganism Rhodopseudomonas parapalustris, demonstrates significantly improved hydrogen production rates compared to traditional devices, showcasing its promise for efficient and sustainable solar energy conversion.
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Storing solar energy in chemical bonds aided by heterogeneous photocatalysis is desirable for sustainable energy conversion. Despite recent progress in designing highly active photocatalysts, inefficient solar energy and mass transfer, the instability of catalysts and reverse reactions impede their practical large-scale applications. Here we tackle these challenges by designing a floatable photocatalytic platform constructed from porous elastomer-hydrogel nanocomposites.

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Background And Objectives: Although long QT syndrome (LQTS) is a potentially life-threatening inherited cardiac channelopathy, studies documenting the long-term clinical data of Korean patients with LQTS are scarce.

Methods: This retrospective cohort study included 105 patients with LQTS (48 women; 45.7%) from a single tertiary center.

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Objective: The management of late-onset scalp wounds following irradiation is troublesome, especially in patients with a surgical history of intracranial neoplasms. It, insidiously, starts with wound dehiscence or discharge and never heals spontaneously without appropriate surgical treatment. Nevertheless, definite treatment guidelines have not yet been established.

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Clogging is ubiquitous. It happens in a wide range of material processing and causes severe performance degradation or process breakdown. In this study, we investigate clogging dynamics in a single micropore by controlling the surface property of the particle and processing condition.

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Background And Objectives: Protein-losing enteropathy (PLE) is a devastating complication after the Fontan operation. This study aimed to investigate the clinical characteristics, treatment response, and outcomes of Fontan-associated PLE.

Methods: We reviewed the medical records of 38 patients with Fontan-associated PLE from 1992 to 2018 in 2 institutions in Korea.

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The evolution of the normal stress and microstructure in the drying process of bidisperse colloidal films is studied using the Brownian dynamics simulation. Here, we show that the formation process of small-on-top stratification can be explained by normal stress development. At high 's, a stratified layer with small particles is formed near the interface.

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Purpose: Heart failure (HF) poses significant morbidity and mortality. Recently, the ventriculo-vascular coupling index (VVI) was introduced as an independent prognostic factor reflective of the overall cardiovascular performance index in HF. We aimed to determine the effectiveness of force-titration of valsartan on VVI values in HF patients.

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Two-dimensional transition metal dichalcogenides (TMDs) offer numerous advantages over silicon-based application in terms of atomically thin geometry, excellent opto-electrical properties, layer-number dependence, band gap variability, and lack of dangling bonds. The production of high-quality and large-scale TMD films is required with consideration of practical technology. However, the performance of scalable devices is affected by problems such as contamination and patterning arising from device processing; this is followed by an etching step, which normally damages the TMD film.

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A ternary composite of poly(lactic acid) (PLA), poly(caprolactone) (PCL), and carbon black (CB) shows the PCL-induced CB self-aggregation and percolation formation when the amount of the PCL phase as the secondary phase is as small as the amount of CB. Furthermore, when the drop size of the PCL phase becomes smaller, the ternary composite forms a percolation of high order structure, resulting in a remarkable enhancement of the electrical conductivity (~4 × 10 S/m with 4 wt.% CB).

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Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) are chemogenetic tools commonly-used to manipulate brain activity. The most widely-used synthetic DREADD ligand, clozapine-N-oxide (CNO), is back-metabolized to clozapine which can itself activate endogenous receptors. Studies in non-DREADD-expressing rodents suggest CNO or a DREADD agonist that lacks active metabolites, such as Compound 21 (C21), change rodent behavior (e.

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We carry out a numerical study to investigate the dynamics of non-Brownian hard-sphere suspensions near the liquid and crystal coexistence region in small to large amplitude oscillatory shear flow. The first normal stress difference (N1) and related rheological functions are carefully analyzed, focusing on the strain stiffening phenomenon, which occurs in the large strain amplitude region. Under oscillatory shear, we observe several unique behaviors of N1.

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A binder plays a critical role in dispersion of coating liquids and the quality of coating. Poly(vinylidene fluoride) (PVDF) is widely used as a binder in cathode slurries; however, its role as a binder is still under debate. In this paper, we study the role of PVDF on the rheology of cathode battery slurries consisting of Li(NiMnCo)O (NCM), carbon black (CB) and N-methyl-2-pyrrolidone (NMP).

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What Is Known And Objective: Pre-treatment of clopidogrel 600 mg is better than 300 mg loading for reducing periprocedural myocardial infarction (PMI). We aimed to evaluate pre-treatment methods for preventing PMI among patients undergoing conventional coronary angiography (CAG) for stable angina pectoris.

Materials And Methods: The study analyzed 402 patients who underwent percutaneous coronary intervention (PCI) during 2010 - 2011 at three Korean hospitals.

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