Publications by authors named "Jahng J"

Article Synopsis
  • Photo-induced force microscopy (PiFM) is a high-resolution imaging technique that utilizes photo-induced forces to enhance tip movement, allowing for detailed nanoscale spectroscopic imaging.
  • This review covers the complexities of PiFM, including the influences of both local dipole interactions and thermal expansion, and distinguishes between far-field and near-field effects.
  • The article serves as a comprehensive guide for beginners, combining theoretical insights with practical examples that span from basic concepts to more advanced topics in the field.
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Article Synopsis
  • * The research introduces the impact of these EVs on THP-1 differentiated macrophages, revealing that they are taken up by the cells and alter the expression of key cytokines linked to immune responses.
  • * Additionally, the EVs cause macrophages to lower their energy production by inhibiting processes like oxidative phosphorylation, suggesting that parasite-derived EVs play a significant role in shaping the immune response and could influence the course of infection.
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Ionizing radiation is widely used in various industrial and medical applications, resulting in increased exposure for certain populations. Lessons from radiation accidents and occupational exposure have highlighted the cardiovascular and cerebrovascular risks associated with radiation exposure. In addition, radiation therapy for cancer has been linked to numerous cardiovascular complications, depending on the distribution of the dose by volume in the heart and other relevant target tissues in the circulatory system.

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Long QT Syndrome (LQTS) is a genetic heart disorder that can induce cardiac arrhythmias. The most prevalent subtype, LQT1, stems from rare variants in the KCNQ1 gene. Utilizing induced pluripotent stem cells (iPSCs) enables detailed cellular studies and personalized medicine approaches for this life-threatening condition.

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The photoinduced dipole force (PiDF) is an attractive force arising from the Coulombic interaction between the light-induced dipoles on the illuminated tip and the sample. It shows extreme sample-tip distance and refractive index dependence, which is promising for nanoscale infrared (IR) imaging of ultrathin samples. However, the existence of PiDF in the mid-IR region has not been experimentally demonstrated due to the coexistence of photoinduced thermal force (PiTF), typically one to two orders of magnitude higher than PiDF.

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Determining the pathogenicity of hypertrophic cardiomyopathy-associated mutations in the β-myosin heavy chain () can be challenging due to its variable penetrance and clinical severity. This study investigates the early pathogenic effects of the incomplete-penetrant G256E mutation on myosin function that may trigger pathogenic adaptations and hypertrophy. We hypothesized that the G256E mutation would alter myosin biomechanical function, leading to changes in cellular functions.

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Identification of new mechanisms mediating insulin sensitivity is important to allow validation of corresponding therapeutic targets. In this study, we first used a cellular model of skeletal muscle cell iron overload and found that endoplasmic reticulum (ER) stress and insulin resistance occurred after iron treatment. Insulin sensitivity was assessed using cells engineered to express an Akt biosensor, based on nuclear FoxO localization, as well as western blotting for insulin signaling proteins.

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Strategies to enhance autophagy flux have been suggested to improve outcomes in cardiac ischemic models. We explored the role of adiponectin in mediating cardiac autophagy under ischemic conditions induced by permanent coronary artery ligation. We studied the molecular mechanisms underlying adiponectin's cardio-protective effects in adiponectin knockout (Ad-KO) compared with wild-type (WT) mice subjected to ischemia by coronary artery ligation and H9c2 cardiomyocyte cell line exposed to hypoxia.

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We, for the first time, report the nanoscopic imaging study of anomalous infrared (IR) phonon enhancement of bilayer graphene, originated from the charge imbalance between the top and bottom layers, resulting in the enhancement of E mode of bilayer graphene near 0.2 eV. We modified the multifrequency atomic force microscope platform to combine photo-induced force microscope with electrostatic/Kelvin probe force microscope constituting a novel hybrid nanoscale optical-electrical force imaging system.

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Article Synopsis
  • Idiopathic pulmonary arterial hypertension (IPAH) is a rare condition affecting 500-1000 individuals yearly, with some cases linked to mutations in the BMPR2 gene, indicating a genetic factor in its onset.
  • Researchers have developed two human induced pluripotent stem cell (iPSC) lines from IPAH patients, which can serve as models to study the disease.
  • These iPSC lines will help researchers gain insights into the biological processes underlying IPAH and could aid in developing new treatments.
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To comprehensively describe the operation of photo-induced force microscopy (PiFM), we have developed a model based on coupled harmonic oscillators. This model features two point masses connected by massless elastic wires, offering greater intuitiveness compared to existing PiFM models. It simplifies these models into a unified theoretical framework.

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Rationale: Over 200 mutations in the sarcomeric protein β-myosin heavy chain (MYH7) have been linked to hypertrophic cardiomyopathy (HCM). However, different mutations in MYH7 lead to variable penetrance and clinical severity, and alter myosin function to varying degrees, making it difficult to determine genotype-phenotype relationships, especially when caused by rare gene variants such as the G256E mutation.

Objective: This study aims to determine the effects of low penetrant MYH7 G256E mutation on myosin function.

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The common aldehyde dehydrogenase 2 () alcohol flushing variant known as affects ∼8% of the world's population. Even in heterozygous carriers, this missense variant leads to a severe loss of ALDH2 enzymatic activity and has been linked to an increased risk of coronary artery disease (CAD). Endothelial cell (EC) dysfunction plays a determining role in all stages of CAD pathogenesis, including early-onset CAD.

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Photo-induced force microscopy (PiFM) is a scan probe technique that offers images with spectroscopic contrast at a spatial resolution in the nanometer range. PiFM utilizes the non-propagating, enhanced near field at the apex of a sharp tip to locally induce a polarization in the sample, which in turn produces an additional force acting on the cantilevered tip. This photo-induced force, though in the pN range or less, can be extracted from the oscillation properties of the cantilever, thus enabling the generation of photo-induced force maps.

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Article Synopsis
  • Hypertrophic cardiomyopathy (HCM) is a genetic heart condition that leads to thickening of the heart muscle, increasing the chances of serious issues like arrhythmias and sudden cardiac death.
  • Researchers created two human-induced pluripotent stem cell (iPSC) lines from HCM patients, each with a mutation in key genes (MYBPC3 and PRKAG2).
  • These iPSC lines show typical pluripotent characteristics and can differentiate into various cell types, which could help in studying HCM and its underlying causes in a lab setting.
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Charge doping to Mott insulators is critical to realize high-temperature superconductivity, quantum spin liquid state, and Majorana fermion, which would contribute to quantum computation. Mott insulators also have a great potential for optoelectronic applications; however, they showed insufficient photoresponse in previous reports. To enhance the photoresponse of Mott insulators, charge doping is a promising strategy since it leads to effective modification of electronic structure near the Fermi level.

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Congenital long QT syndrome type 1 (LQT1) results from KCNQ1 mutations that cause loss of Kv7.1 channel function, leading to arrhythmias, syncope, and sudden cardiac death. Here, we generated three human-induced pluripotent stem cell (iPSC) lines from peripheral blood mononuclear cells (PBMCs) of LQT1 patients carrying pathogenic variants (c.

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MYH7 heterozygous mutations are common genetic causes of hypertrophic cardiomyopathy (HCM). HCM is characterized by hypertrophy of the left ventricle and diastolic dysfunction. We generated three human induced pluripotent stem cell (iPSC) lines from three HCM patients each carrying a single heterozygous mutation in MYH7, c.

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The advent of induced pluripotent stem cells (iPSCs) and identification of transcription factors for cardiac reprogramming have raised hope to cure heart disease, the leading cause of death in the world. Our knowledge in heart development and molecular barriers of cardiac reprogramming is advancing, but many hurdles are yet to be overcome for clinical translation. Importantly, we lack a full understanding of molecular mechanisms governing cell fate conversion toward cardiomyocytes.

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Congenital long QT syndrome type 2 (LQT2) results from KCNH2 mutations that cause loss of Kv11.1 channel function which can lead to arrhythmias, syncope, and sudden death. Here, we generated three human-induced pluripotent stem cell (iPSC) lines from peripheral blood mononuclear cells (PBMCs) of two LQT2 patients carrying pathogenic variants (c.

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Hypertrophic cardiomyopathy (HCM) is an inherited heart disease that can cause sudden cardiac death and heart failure. HCM often arises from mutations in sarcomeric genes, among which the MYBPC3 is the most frequently mutated. Here we generated two human induced pluripotent stem cell (iPSC) lines from a HCM patient who has a familial history of HCM and his daughter who carries the pathogenic non-coding mutation.

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