-
Two-Photon Fluorescent Probes for Quantitative Bio-Imaging Analysis in Live Tissues by Vinayak Juvekar;Hyo Won Lee;Dong Joon Lee;Hwan Myung Kim TRAC-TRENDS IN ANALYTICAL CHEMISTRY 2022, 157(0); https://doi.org/10.1016/j.trac.2022.116787 Abstract Two-photon (TP) microscopy (TPM) is an indispensable visualization tool for deep-tissue imaging. TPM uses the low energy light of the near-infrared window as an excitation source of fluorophores which reduces autofluorescence, photodamage, and light scattering, resulting in high resolution fluorescence images potentially beyond several millimeter depths in living systems. Due to the continuous development of the microscope and advances in optical output algorithms, it is crucial to develop innovative strategies for the quantitative analysis of biomedically relevant target analytes in living systems using TP fluorescence probes. In this review, we have highlighted ratiometric TP probe design strategies with representative ratiometric TP sensors in the last decade. We have also summarized the recent progress in the development of TP probes published between 2017 and 2022 for quantitatively detecting analytes such as enzymes, reactive species, bio-thiols, pH, neutral molecules, and metal ions in live cells and tissues. Keywords: Bio-imagingQuantitative analysisTwo-photon probesTissue imagingTwo-photon microscopy
-
39
- 작성자박은영
- 작성일2023-01-16
- 286
- 동영상동영상
-
-
37
- 작성자박은영
- 작성일2023-01-16
- 256
- 동영상동영상
-
Cytoplasmic molecular chaperones in Pseudomonas species. by Hyunhee Kim;Seongjoon Moon;Soojeong Ham;Kihyun Lee;Ute Römling;Changhan Lee Journal of Microbiology 2022, 60(0); https://doi.org/10.1007/s12275-022-2425-0 Abstract Pseudomonas is widespread in various environmental and host niches. To promote rejuvenation, cellular protein homeostasis must be finely tuned in response to diverse stresses, such as extremely high and low temperatures, oxidative stress, and desiccation, which can result in protein homeostasis imbalance. Molecular chaperones function as key components that aid protein folding and prevent protein denaturation. Pseudomonas, an ecologically important bacterial genus, includes human and plant pathogens as well as growth-promoting symbionts and species useful for bioremediation. In this review, we focus on protein quality control systems, particularly molecular chaperones, in ecologically diverse species of Pseudomonas, including the opportunistic human pathogen Pseudomonas aeruginosa, the plant pathogen Pseudomonas syringae, the soil species Pseudomonas putida, and the psychrophilic Pseudomonas antarctica.
-
35
- 작성자박은영
- 작성일2023-01-16
- 263
- 동영상동영상
-
A Method to Study α-Synuclein Toxicity and Aggregation Using a Humanized Yeast Model by Hyunhee Kim;Juwon Jeong;Changhan Lee Journal of Visualized Experiments 2022, 189(0); https://doi.org/10.3791/64418 Abstract Parkinson's disease is the second most common neurodegenerative disorder and is characterized by progressive cell death caused by the formation of Lewy bodies containing misfolded and aggregated α-synuclein. α-synuclein is an abundant presynaptic protein that regulates synaptic vesicle trafficking, but the accumulation of its proteinaceous inclusions results in neurotoxicity. Recent studies have revealed that various genetic factors, including bacterial chaperones, could reduce the formation of α-synuclein aggregates in vitro. However, it is also important to monitor the anti-aggregation effect in the cell to apply this as a potential treatment for the patients. It would be ideal to use neuronal cells, but these cells are difficult to handle and take a long time to exhibit the anti-aggregation phenotype. Therefore, a quick and effective in vivo tool is required for the further evaluation of in vivo anti-aggregation activity. The method described here was used to monitor and analyze the anti-aggregation phenotype in the humanized yeast Saccharomyces cerevisiae, which expressed human α-synuclein. This protocol demonstrates in vivo tools that could be used for monitoring α-synuclein-induced cellular toxicity, as well as the formation of α-synuclein aggregates in cells. ,
-
33
- 작성자박은영
- 작성일2023-01-16
- 261
- 동영상동영상
-
-
31
- 작성자박은영
- 작성일2023-01-16
- 257
- 동영상동영상
-
Advances in Small Molecule Two-Photon Fluorescent Trackers for Lipid Droplets in Live Sample Imaging by Dong Joon Lee;Eun Seo Kim;Hyo Won Lee;Hwan Myung Kim Frontiers in Chemistry 2022, 10(0); https://doi.org/10.3389/fchem.2022.1072143 Abstract Two-photon fluorescent trackers for monitoring of lipid droplets (LDs) would be highly effective for illustrating the critical roles of LDs in live cells or tissues. Although a number of one-photon fluorescent trackers for labeling LDs have been developed, their usability remains constrained in live sample imaging due to photo damage, shallow imaging depth, and auto-fluorescence. Recently, some two-photon fluorescent trackers for LDs have been developed to overcome these limitations. In this mini-review article, the advances in two-photon fluorescent trackers for monitoring of LDs are summarized. We summarize the chemical structures, two-photon properties, live sample imaging, and biomedical applications of the most recent representative two-photon fluorescent trackers for LDs. Additionally, the current challenges and future research trends for the two-photon fluorescent trackers of LDs are discussed.
-
29
- 작성자박은영
- 작성일2023-01-16
- 280
- 동영상동영상
-
Recent Advances in Biosensor Technologies for Point-of-Care Urinalysis by Chuljin Hwang;Won-June Lee;Su Dong Kim;Sungjun Park;Joo Hee Kim Biosensors 2022, 12(11); https://doi.org/10.3390/bios12111020 Abstract Human urine samples are non-invasive, readily available, and contain several components that can provide useful indicators of the health status of patients. Hence, urine is a desirable and important template to aid in the diagnosis of common clinical conditions. Conventional methods such as dipstick tests, urine culture, and urine microscopy are commonly used for urinalysis. Among them, the dipstick test is undoubtedly the most popular owing to its ease of use, low cost, and quick response. Despite these advantages, the dipstick test has limitations in terms of sensitivity, selectivity, reusability, and quantitative evaluation of diseases. Various biosensor technologies give it the potential for being developed into point-of-care (POC) applications by overcoming these limitations of the dipstick test. Here, we present a review of the biosensor technologies available to identify urine-based biomarkers that are typically detected by the dipstick test and discuss the present limitations and challenges that future development for their translation into POC applications for urinalysis. Keywords: urine sensor; point-of-care urinalysis; clinical application for urinalysis; dipstick test; biosensors
-
27
- 작성자박은영
- 작성일2023-01-16
- 258
- 동영상동영상
-
Enhancing the oxidation resistance of nanocrystalline high-entropy AlCuCrFeMn alloys by the addition of tungsten by Sheetal Kumar Dewangan;Devesh Kumar; Ashutosh Sharma;Byungmin Ahn;Vinod Kumar Journal of Materials Research and Technology-JMR&T 2022, 21(0); https://doi.org/10.1016/j.jmrt.2022.11.078 Abstract The isothermal oxidation behavior of multi-component high entropy alloys (HEAs), namely AlCuCrFeMn, AlCuCrFeMnW0.05, AlCuCrFeMnW0.1, and AlCuCrFeMnW0.5, was investigated and the behavior of the oxide layer was analyzed. All four HEAs were synthesized via mechanical alloying (MA) and consolidated by spark plasma sintering (SPS). The samples were oxidized in the air atmosphere at a temperature of 500 °C for 50 h. Based on the thermogravimetric result, the oxidation rate of the materials decreased with the increase of W content, and the values of parabolic constants were on a level similar to those observed in Ni–Al superalloys. However, higher content of W improves the continuity and internal position of the WO3 scale, which leads to increased oxidation resistance. Throughout the oxidation process, the composition of the phases of all materials changed significantly. The triple-thick oxide layer formed of Al2O3, Cr2O3, and WO3, developed in HEAs, has been carefully studied using the XPS technique. Keywords: High-entropy alloyOxide resistanceNanocrystallinePowder metallurgy
-
25
- 작성자박은영
- 작성일2023-01-16
- 272
- 동영상동영상
-
-
23
- 작성자박은영
- 작성일2023-01-16
- 272
- 동영상동영상
-
Quasiresonant diffusion of wave packets in one-dimensional disordered mosaic lattices by Ba Phi Nguyen;Duy Khuong Phung;Kihong Kim Physical Review B 2022, 106(13); https://doi.org/10.1103/PhysRevB.106.134204 Abstract We investigate numerically the time evolution of wave packets incident on one-dimensional semi-infinite lattices with mosaic modulated random on-site potentials, which are characterized by the integer-valued modulation period κ and the disorder strength W. For Gaussian wave packets with the central energy E0 and a small spectral width, we perform extensive numerical calculations of the disorder-averaged time-dependent reflectance, 〈R(t)〉, for various values of E0, κ, and W. We find that the long-time behavior of 〈R(t)〉 obeys a power law of the form t−γ in all cases. In the presence of the mosaic modulation, γ is equal to 2 for almost all values of E0, implying the onset of the Anderson localization, while at a finite number of discrete values of E0 dependent on κ, γ approaches 3/2, implying the onset of the classical diffusion. This phenomenon is independent of the disorder strength and arises in a quasiresonant manner such that γ varies rapidly from 3/2 to 2 in a narrow energy range as E0 varies away from the quasiresonance values. We deduce a simple analytical formula for the quasiresonance energies and provide an explanation of the delocalization phenomenon based on the interplay between randomness and band structure and the node structure of the wave functions. We explore the nature of the states at the quasiresonance energies using a finite-size scaling analysis of the average participation ratio and find that the states are neither extended nor exponentially localized, but critical states.
-
21
- 작성자박은영
- 작성일2023-01-16
- 274
- 동영상동영상