Publications by authors named "Kipom Kim"
Parietal-Frontal Pathway Controls Relapse of Fear Memory in a Novel Context.
Biol Psychiatry Glob Open Sci
July 2024
Article Synopsis
- The study explores how fear responses can resurface in new situations and the challenges this poses for therapies that aim to reduce fear.
- Researchers investigated the role of specific brain regions (posterior parietal cortex and anterior cingulate cortex) using advanced techniques to understand the circuits involved in fear relapse.
- Findings revealed that the pathway from the PPC to the ACC is crucial for this fear resurgence, with changes in neuron activity and the influence of parvalbumin-expressing interneurons affecting this process.
Article Synopsis
- - Biomedical research on the brain has made significant strides in understanding consciousness and addressing brain diseases, but has historically faced challenges like complex interpretations and limited collaboration among researchers from different fields.
- - The progression of brain research has been slower than other biomedical areas due to these complexities, but recent advancements in high-throughput analysis tools have initiated a significant shift towards patient-centered, large-scale studies.
- - Innovations in neuroimaging, multiomics, and artificial intelligence are leading the way for transformative changes in brain research, while interdisciplinary approaches are helping to tackle unresolved biomedicine questions.
Article Synopsis
- - Adult neurogenesis involves the creation of new neurons from neural stem cells in areas like the hippocampus, and dietary components can influence this process.
- - A study examined the effects of different doses of curcumin, a compound found in curry, on mouse brain function, finding that low doses (0.4 mg/kg) increased the growth and survival of new neurons while high doses (10 mg/kg) did not have the same effect.
- - Results indicated that low-dose curcumin improved memory retention in tests and boosted levels of brain-derived neurotrophic factor (BDNF) and certain cellular activity markers, suggesting its potential to counteract cognitive decline related to aging or neurodegenerative diseases.
Article Synopsis
- SimPET-L and SimPET-XL are advanced positron emission tomography (PET) systems designed for whole-body imaging of rats, featuring larger fields of view compared to earlier models, enhancing imaging capabilities.
- Both systems utilize silicon photomultiplier arrays and specialized crystal detectors, and they were rigorously evaluated according to a national protocol, demonstrating improved radial resolution and peak sensitivity.
- The results indicate that SimPET-XL outperforms SimPET-L in terms of uniformity and image quality, making it a beneficial tool for rat imaging studies like F-NaF and F-FDG PET.
Article Synopsis
- Studies show that nitric oxide synthase 2 (NOS2) is linked to Alzheimer's disease, but its role in Parkinson's disease (PD) is less understood.
- Researchers used mouse models with the A53T mutation of α-synuclein to explore the effects of deleting NOS2 on PD pathology.
- The findings revealed that removing NOS2 reduced phosphorylation of α-synuclein and decreased neuroinflammatory responses, indicating that NOS2 deletion may help alleviate α-synuclein-related issues in the brain.
Article Synopsis
- Mild traumatic brain injury (mTBI) is common, but understanding its neurological effects and diagnostic criteria is still developing, particularly in relation to brainstem connectivity.* -
- Recent studies in mice revealed that functional connectivity in the brainstem significantly declines after a concussion, particularly noticeable on day 7 post-injury, but trends towards normalization by day 14.* -
- The research also found correlations between changes in local network properties of the brainstem and anxiety-like behaviors, highlighting the importance of functional reorganization during recovery from concussions.*
Article Synopsis
- * This study focused on understanding the structure and behavior of the MLC1 protein, revealing it has eight transmembrane (TM) domains with both ends facing the cytoplasm.
- * The researchers discovered that MLC1 can form oligomers, specifically trimeric complexes, and the findings set the stage for detailed structural and functional studies of the protein.
Background: Low-intensity transcranial focused ultrasound stimulation is a promising candidate for noninvasive brain stimulation and accurate targeting of brain circuits because of its focusing capability and long penetration depth. However, achieving a sufficiently high spatial resolution to target small animal sub-regions is still challenging, especially in the axial direction.
Objective: To achieve high axial resolution, we designed a dual-crossed transducer system that achieved high spatial resolution in the axial direction without complex microfabrication, beamforming circuitry, and signal processing.
Article Synopsis
- Alzheimer's disease (AD) is a common but poorly understood neurodegenerative condition with no cure, leading to research into stem cell treatments, particularly mesenchymal stem cells (MSCs).
- MSCs show promise in animal studies for AD by reducing neuroinflammation, clearing toxic proteins, enhancing cognitive function, and improving brain health.
- The review highlights the potential benefits of MSC-based therapies while also discussing current limitations and future directions for stem cell research in treating AD.
Article Synopsis
- Recent advancements in DNA origami design still depend on traditional thermal or chemical methods for folding.
- This study introduces mechanical folding using magnetic tweezers to stretch DNA, which enhances its structure by eliminating secondary formations before stabilizing it with staple strands.
- The mechanical process allows for rapid and efficient folding of DNA nanostructures within 10 minutes and enables parallel processing, paving the way for more programmable DNA origami techniques.
Article Synopsis
- A new biosensor has been developed that doesn't require labels to detect biomolecular interactions.
- It can measure the concentration of target biomolecules ranging from 10 nM to 0.1 pM.
- The biosensor offers high selectivity and sensitivity, making it effective for a wide range of applications.
Article Synopsis
- The study explores how local laser heating affects the shape and motion of oil droplets in water, observing various behaviors like breathing, crawling, budding, and splitting depending on the laser power.
- The researchers discovered that these behaviors result from dynamic instabilities caused by the interaction of convection flows and capillary effects.
- The findings have practical implications for creating microfluidic devices to manipulate droplet behavior using laser power and for enhancing our understanding of thermal systems with soft boundaries.
Coimmunoprecipitation (co-IP) analysis is a useful method for studying protein-protein interactions. It currently involves electrophoresis and western blotting, which are not optimized for detecting weak and transient interactions. In this protocol we describe an advanced version of co-IP analysis that uses real-time, single-molecule fluorescence imaging as its detection scheme.
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- The study investigates how the SNARE complex, which is important for membrane fusion, responds mechanically under various forces using magnetic tweezers.
- It was found that a single SNARE complex can be unzipped at a force of 34 pN, but can only reassemble into a partially formed state at a lower force of 11 pN, with the C-terminal part remaining disassembled.
- The research highlights a phenomenon called mechanical hysteresis, where the complex's structure ensures a specific directionality in its formation, making it an effective mechanism for generating force.
Article Synopsis
- A new photonic force microscope was created to simultaneously measure various parameters, like surface topography and biomolecular interactions.
- The technique tracks the probe bead's position and contact with the sample using video analysis of a light diffraction pattern.
- The microscope successfully demonstrated the ability to measure DNA molecule distribution, binding strength of DNA hybridization, and the surface topography.
Optical vortex trapping can allow the capture and manipulation of micro- and nanometre-sized objects such as damageable biological particles or particles with a refractive index lower than the surrounding material. However, the quest for nanometric optical vortex trapping that overcomes the diffraction limit remains. Here we demonstrate the first experimental implementation of low-power nano-optical vortex trapping using plasmonic resonance in gold diabolo nanoantennas.
View Article and Find Full Text PDFA high-resolution magnetic tweezer for single-molecule measurements.
Nucleic Acids Res
November 2009
Article Synopsis
- Magnetic tweezers are tools that use a magnetic field to manipulate and measure the extension of biomolecules attached to magnetic beads, allowing scientists to study molecular behavior.
- Previous implementations of magnetic tweezers lacked the resolution needed to observe very small (sub-nanometer) changes in biomolecular structures.
- The authors introduce a new reflection-interference technique that significantly improves measurement resolution and demonstrate its effectiveness by measuring changes in the length of a DNA hairpin during folding and unfolding.
Article Synopsis
- Reflection interference contrast microscopy (RICM) is used to analyze microscopic objects' shape and position in various biological and physical contexts.
- To improve long-term measurements, a new method was developed that minimizes errors from thermal and mechanical drift by using a linear focus function for feedback control of the microscope's focal position.
- This method resulted in highly stable measurements, as demonstrated by a 45-minute test showing a standard deviation of just 0.12 nm in the height of an immobilized bead.
Jamming transition in a highly dense granular system under vertical vibration.
Phys Rev E Stat Nonlin Soft Matter Phys
July 2005
The dynamics of the jamming transition in a three-dimensional granular system under vertical vibration is studied using diffusing-wave spectroscopy. When the maximum acceleration of the external vibration is large, the granular system behaves like a fluid, with the dynamic correlation function G (t) relaxing rapidly. As the acceleration of vibration approaches the gravitational acceleration g , the relaxation of G (t) slows down dramatically, and eventually stops.
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- The study investigated how patterns form in granular materials under vertical vibrations in a vacuum setup.
- Researchers manipulated the system's parameters, specifically dimensionless acceleration (Gamma) and vibration frequency (f), to observe changes in pattern formation.
- They found that transitioning from a flat to a striped pattern took over 10,000 cycles, and the growth of the ordered patterns followed dynamic scaling laws, with a growth exponent of 0.25 that aligns with existing theories.