Publications by authors named "Yo Han Song"

Article Synopsis
  • Synaptic vesicle transport along microtubules is essential for communication between neurons, but tau-hyperphosphorylation destabilizes microtubules and affects this transport process.
  • Research shows that in cells with tau-hyperphosphorylation, the transport of vesicle-motor protein multiplexes (VMPMs) is slowed down and exhibits erratic motion instead of smooth, unidirectional transport.
  • A new physicochemical model explains these changes in motion and suggests that disrupted vesicle transport could be linked to neurodegenerative disorders associated with tau-hyperphosphorylation.
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  • CRISPR-Cas12a is an RNA-guided enzyme that creates double-strand breaks in DNA by first cutting a non-target strand and then the target strand.
  • Research using single-molecule FRET revealed that the 3' overhangs of both the non-target strand and the guide RNA (crRNA) block the target strand from entering the enzyme's active site.
  • The study provides valuable insights into how these overhangs affect the cleavage process of Cas12a, which could inform future strategies for regulating its activity.
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The CRISPR-Cas12a system has emerged as a promising tool for molecular diagnostics due to its indiscriminate trans-ssDNase activity. However, the sensitivity of Cas12a-based diagnostics remains insufficient for clinical use without a pre-amplification step such as loop-mediated isothermal amplification, and therefore the trans-cleavage activity of Cas12a needs to be enhanced. Here, we present a novel strategy to enhance the trans-cleavage activity of Cas12a by reducing the steric hindrance from cis-cleavage products.

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Blood-brain barrier (BBB) serves as an essential interface between central nervous system (CNS) and its periphery, allowing selective permeation of ions, gaseous molecules, and other nutrients to maintain metabolic functions of brain. Concurrently, it restricts passage of unsolicited materials from bloodstream to CNS which could otherwise lead to neurotoxicity. Nevertheless, in the treatment of neurodegenerative diseases such as Parkinson's, Alzheimer's, diffuse intrinsic pontine glioma, and other brain cancers, drugs must reach CNS.

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The delicate tertiary structure of proteins, their susceptibility to heat- and enzyme-induced irreversible denaturation, and their tendency to get accumulated at the cell membrane during uptake are daunting challenges in proteinaceous therapeutic delivery. Herein, a polyelectrolyte complex having encapsulated therapeutic protein has been designed on the surface of upconverting luminescent nanoparticles (NaYF:20%Yb,2%Er). This nanosized complex system has been found to overcome the challenges of protein aggregation at the cell membrane.

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Virtual reality (VR)-based therapies are widely used in stroke rehabilitation. Although various studies have used VR techniques for bilateral upper limb training, most have been only semi-immersive and have only been performed in an artificial environment. This study developed VR content and protocols based on activities of daily living to provide immersive VR-based bilateral arm training (VRBAT) for upper limb rehabilitation in stroke patients.

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Tauopathy is the aggregation phenomenon of tau proteins and associated with neurodegenerative diseases. It metastasizes via the transfer of tau aggregates to adjacent neuron cells; however, the mechanism has not yet been fully understood. Moreover, if the materials used for designing drug delivery system to treat such neurodegenerative diseases do not undergo biodegradation or exocytosis but remains in cells or tissues, they raise concerns about their possible negative impacts.

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Pyruvate dehydrogenase kinase (PDK) controls the activity of pyruvate decarboxylase complex (PDC) by phosphorylating key serine residues on the E1 subunit, which leads to a decreased oxidative phosphorylation in mitochondria. Inhibition of PDK activity by natural/synthetic compounds has been shown to reverse the Warburg effect, a characteristic metabolism in cancer cells. PDK-PDC axis also has been associated with diabetes and heart disease.

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Vesicle transport conducted by motor protein multiplexes (MPMs), which is ubiquitous among eukaryotes, shows anomalous and stochastic dynamics qualitatively different from the dynamics of thermal motion and artificial active matter; the relationship between in vivo vesicle-delivery dynamics and the underlying physicochemical processes is not yet quantitatively understood. Addressing this issue, we perform accurate tracking of individual vesicles, containing upconverting nanoparticles, transported by kinesin-dynein-multiplexes along axonal microtubules. The mean-square-displacement of vesicles along the microtubule exhibits unusual dynamic phase transitions that are seemingly inconsistent with the scaling behavior of the mean-first-passage time over the travel length.

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Lanthanide-doped upconversion nanoparticles (UCNPs) are inorganic nanomaterials in which the lanthanide cations embedded in the host matrix can convert incident near-infrared light to visible or ultraviolet light. These particles are often used for long-term and real-time imaging because they are extremely stable even when subjected to continuous irradiation for a long time. It is now possible to image their movement at the single particle level with a scale of a few nanometers and track their trajectories as a function of time with a scale of a few microseconds.

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Article Synopsis
  • Diets rich in chemopreventive agents like genistein, found in soy, show promise for maintaining health and fighting chronic diseases such as cancer.
  • Genistein's cancer-fighting potential is hindered by issues like poor absorption and low solubility, limiting its effectiveness in clinical settings.
  • Innovative nanocarriers made from polymers are being developed to enhance genistein's pharmacological properties and improve its application in cancer therapy.
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The surface characteristics and osteoconductivity were evaluated for the micro/nanoporous surfaces of titanium (Ti) alloys prepared by micro-arc oxidation (MAO) and hydrothermal treatment (HT) of binary Ti-5 wt% A alloys (A = Au, Mn, Nb, and Pd). Surface properties were analyzed using X-ray diffractometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The osteoconductivity was evaluated by measuring the total protein, ALPase activity, and osteocalcin production.

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Understanding the interaction of nanoparticles with living cells on the basis of cellular uptake efficiency is a fundamental requisite in biomedical research. Cellular internalization of nanoparticles takes place by mechanisms like ATP hydrolysis-driven endocytosis that deliver nanoparticles to the cytoplasm, organelles and nuclei. Despite its importance in nanomedicine, this uptake procedure is not understood in-depth because of the complexity of the biochemical mechanisms and the lack of available experimental methods for quantitative analysis.

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Article Synopsis
  • A new 3D live-cell imaging technique has been developed using lanthanide-doped upconverting nanoparticles (UCNPs), which enhances spatial and temporal resolution.
  • This technique combines the benefits of confocal microscopy with wide-field epi-fluorescence, allowing for clearer 2D images despite typical issues like out-of-focus backgrounds.
  • The method reduces background noise from autofluorescence and effectively reconstructs images to eliminate blurring, enabling detailed studies of cellular processes like nuclear uptake and tracking individual particles in three dimensions.
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  • The study investigates the surface characteristics and osteoconductivity of micro/nanostructured oxide layers on titanium created using anodic oxidation, chemical etching, and hydrothermal treatment.
  • The P-ANO group had a porous surface with micro-sized pores, while treatments resulted in reduced pore size and the formation of nano-sized crystallites in the P-ANO-Et-HT group, enhancing their hydrophilicity.
  • Although the P-ANO-Et-HT group showed low initial cell adhesion in SEM images, it exhibited faster osteoconductivity growth compared to traditional micro-structured surfaces, suggesting potential for improved titanium implant fabrication.
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Surface characteristics and osteoblast cell functions were investigated for the nano-structured oxide layer on commercially pure titanium (CP-Ti) fabricated using microarc oxidation (MAO) and hydrothermal treatment (HT) methods. Ti-MAO-135HT, Ti-MAO-150HT, and Ti-MAO-175HT groups were fabricated by hydrothermally treating the MAO-treated specimens (Ti-MAO) in phosphorus-containing alkaline solution at temperatures of 135, 150, or 175 °C, respectively. After hydrothermal treatment, a nanosheet-shaped morphology, nano-needles and nanorods were observed on the porous surface of the Ti-MAO-135HT, Ti-MAO-150HT and Ti-MAO-175HT groups, respectively.

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Objective: This study was performed to evaluate the biocompatibility of nine types of pure metals using 36 experimental prosthetic titanium-based alloys containing 5, 10, 15, and 20wt% of each substituted metal.

Methods: The cell viabilities for pure metals on Ti alloys that contain these elements were compared with that of commercially pure (CP) Ti using the WST-1 test and agar overlay test.

Results: The ranking of pure metal cytotoxicity from most potent to least potent was: Co>Cu>In>Ag>Cr>Sn>Au>Pd>Pt>CP Ti.

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Purpose: To evaluate the difference in cytotoxicity of soft denture lining materials depending on their component types.

Materials And Methods: Ten commercially available soft denture lining materials (SDLM) consisting of five silicone-based materials and five acrylic-based materials were evaluated. For the MTT test, cured SDLM samples were extracted in a culture medium for 24 hours, and L-929 cells were incubated in the extracted medium for 24 hours.

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Objective: This study was performed to evaluate the biocompatibility of nine types of pure metal ingots (Ag, Al, Cr, Cu, Mn, Mo, Nb, V, Zr) and 36 experimental titanium (Ti) alloys containing 5, 10, 15, and 20 wt% of each alloying element.

Methods: The cell viabilities for each test group were compared with that of CP-Ti using the WST-1 test and agar overlay test.

Results: The ranking of pure metal cytotoxicity from most potent to least potent was as follows: Cu>Al>Ag>V>Mn>Cr>Zr>Nb>Mo>CP-Ti.

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The composition and the antibacterial activity of the essential oil obtained from Cryptomeria japonica D. Don on oral bacteria were studied. The chemical composition of the essential oil was analysed by GC and GC-MS.

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Background: Since many bacterial genes are environmentally regulated, the screening for virulence-associated factors using classical genetic and molecular biology approaches can be biased under laboratory growth conditions of a given pathogen, because the required conditions for expression of many virulence factors may not occur during in vitro growth. Thus, technologies have been developed during the past several years to identify genes that are expressed during disease using animal models of human disease. However, animal models are not always truly representative of human disease, and with many pathogens, there is no appropriate animal model.

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The chemical components of the essential oil obtained from Artemisia lavandulaefolia DC. were analyzed by GC-MS. Ninety-nine compounds accounting for 94.

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The chemical composition of the essential oils obtained from Artemisia scoparia Waldst. et Kitamura and Artemisia capillaris Thunb. was analyzed by GC/MS.

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