Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
342
result(s) for
"Lee, Youngjae"
Sort by:
High-speed compressed-sensing fluorescence lifetime imaging microscopy of live cells
by
Gao, Liang
,
Best-Popescu, Catherine
,
Lee, Youngjae
in
Applied Biological Sciences
,
Biological Sciences
,
Engineering
2021
We present high-resolution, high-speed fluorescence lifetime imaging microscopy (FLIM) of live cells based on a compressed sensing scheme. By leveraging the compressibility of biological scenes in a specific domain, we simultaneously record the time-lapse fluorescence decay upon pulsed laser excitation within a large field of view. The resultant system, referred to as compressed FLIM, can acquire a widefield fluorescence lifetime image within a single camera exposure, eliminating the motion artifact and minimizing the photobleaching and phototoxicity. The imaging speed, limited only by the readout speed of the camera, is up to 100 Hz. We demonstrated the utility of compressed FLIM in imaging various transient dynamics at the microscopic scale.
Journal Article
Sternum drop during trip recovery differs between the laboratory and real world – An exploratory pilot study
by
Lee, Youngjae
,
Alexander, Neil B.
,
Madigan, Michael L.
in
Accidental Falls - prevention & control
,
Accidents
,
Aged
2025
The goal of this exploratory study was to compare sternum drop—the decrease in sternum height during an attempt to recover balance after tripping—between lab-induced trips and naturally occurring real-world trips. Twenty community-dwelling adults 71.8 (4.6) years old used three inertial measurement units (IMUs) and a wrist-worn voice recorder daily for three weeks to capture sternum drop during any naturally-occurring real-world trips. Participants then completed a single laboratory testing session during which they were intentionally exposed to two lab-induced trips while wearing the same IMUs to also evaluate sternum drop. All real-world trips resulted in recoveries while only 12 of the 22 lab-induced trips resulted in recoveries (the remaining 10 were falls). When including all lab-induced trips, sternum drop after real-world trips was 8.8 cm smaller ( p < 0.001), exhibited less variance ( p < 0.001), and was not associated with lab-induced trips ( R 2 = 0.005; p = 0.757). When only including lab-induced trips that resulted in recoveries, sternum drop after real-world trips did not differ from the lab ( p = 0.163), exhibited less variance ( p < 0.001) and was not associated with lab-induced trips ( R 2 = 0.006; p = 0.766). These results were likely dependent upon 1) our lab protocol that required participants to walk at a gait speed that was likely faster than typical gait speed in the real-world, and 2) the aggressive lab tripping obstacle height of 8.6 cm was likely taller than at least some real-world trips. While reducing gait speed and obstacle height in future laboratory studies may improve agreement with real-world trips, this would lower the physical demands during recovery and may not be as effective at revealing factors contributing to falls. Nevertheless, additional research appears warranted to clarify the linkage between lab and real-world trips. To our knowledge, this is the first study comparing tripping kinematics between the lab and real world.
Journal Article
Industrial Wastewater Discharge and Compliance Investigation for Environmentally Resilient Rwanda
2022
While Rwanda is aiming at environmental pollution resilience and green growth, some industries are still discharging untreated effluent into the environment. This study gives a general overview of the compliance level of industrial effluent discharge in Rwanda and the linked negative environmental impacts. It comprises qualitative and quantitative analyses of data obtained from wastewater samples collected from five selected industries in Rwanda. The selected industries had previously been audited and monitored by the Rwanda Environment Management Authority (REMA), due to complains from neighboring residents. The study found that the effluent discharge from wastewater treatment plants (WWTP) for all concerned industries failed to comply with (i) oil and grease (O&G) national and international tolerable parameter limits or the (ii) fecal coliforms national standard. In addition, a compliance level of 66.7% was observed for key water quality monitoring parameters (pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and heavy metals (i.e., lead (Pb), cadmium (Cd), and chromium (Cr)). Following these study findings, one industry was closed by the REMA for deliberately discharging untreated effluent into an adjacent river. This study recommends the adoption of the best available technology for effluent treatment, installation or renovation of existing WWTPs, and the relocation to industrial zones of industries adjacent to fragile environments.
Journal Article
CD99-mediated immunological synapse formation potentiates CAR-T cell function
by
Cho, Byoung-Kyu
,
Park, Hyung Bae
,
Jung, Hyeryeon
in
12E7 Antigen - genetics
,
12E7 Antigen - immunology
,
12E7 Antigen - metabolism
2025
Despite the efficacy of chimeric antigen receptor (CAR)-T cells in selected hematological malignancies, further improvement on CAR-T designs is still desirable. We hypothesize that modifying the CAR structure to enhance immunological synapse (IS) stabilization and CAR target-binding may be a feasible strategy. Here we show that the membrane protein, CD99, is critical for IS formation in T cells by mediating actin-microtubule interaction. CD99 deficiency abolishes IS formation and prevents effective in vivo T cell immunity. Mechanistically, CD99 interacts with microtubules and actins through the transmembrane and cytoplasmic domains, respectively, with which myosin and IQGAP1 interact. As such, incorporating the transmembrane and juxtamembrane domains of CD99 into the CAR structure enhances IS formation and improves the therapeutic efficacy of human CAR-T cells against lymphoma in immune-deficient mice. Our data thus suggest that CD99-mediated IS stabilization may help improve CAR design and efficacy.
Chimeric antigen receptor (CAR)-T cell is a promising therapy for hematological malignancy, but further optimization is still desirable. Here the authors show that incorporating CD99, a membrane protein expressed on activated T cells, transmembrane and juxtamembrane domains into CAR design helps improve CAR-T efficacy in vitro and in vivo in mice.
Journal Article
Reconceptualizing Incomplete Attempt
Incomplete attempt laws are typically explained as laws that exist to justify timely law enforcement intervention. Such explanations may well provide good reasons for the laws based on harm prevention rationales, but they do not address the question whether a person who has, say, “cocked and aimed the pistol” has actually attempted to kill and is blameworthy for having done so. It turns out that this question is notoriously difficult to answer. This Article describes the challenge of defining incomplete attempt and of identifying and articulating its wrongfulness as a general theoretical matter. This Article then argues in favor of conceptualizing incomplete attempt as an offense of disobedience of the state, as opposed to an offense the wrongfulness of which stems from trying to engage in a morally wrongful act. Such reconceptualization can then serve as a basis for building a more clearly articulated account of blameworthiness of incomplete attempts.
Journal Article
Effect of Probabilistic Similarity Measure on Metric-Based Few-Shot Classification
2021
In developing a few-shot classification model using deep networks, the limited number of samples in each class causes difficulty in utilizing statistical characteristics of the class distributions. In this paper, we propose a method to treat this difficulty by combining a probabilistic similarity based on intra-class statistics with a metric-based few-shot classification model. Noting that the probabilistic similarity estimated from intra-class statistics and the classifier of conventional few-shot classification models have a common assumption on the class distributions, we propose to apply the probabilistic similarity to obtain loss value for episodic learning of embedding network as well as to classify unseen test data. By defining the probabilistic similarity as the probability density of difference vectors between two samples with the same class label, it is possible to obtain a more reliable estimate of the similarity especially for the case of large number of classes. Through experiments on various benchmark data, we confirm that the probabilistic similarity can improve the classification performance, especially when the number of classes is large.
Journal Article
An Ectopic Parathyroid Adenoma of the Retropharynx in a Patient with Primary Hyperparathyroidism and Papillary Thyroid Cancer—A Rare Case
by
Cho, Jiwoong
,
Oh, Jeonghyun
,
Lee, Youngjae
in
Cartilage
,
Conflicts of interest
,
ectopic parathyroid
2024
The frequency of concurrent thyroid cancer in patients with primary hyperparathyroidism (pHPT) varies. While the pathological association between thyroid and parathyroid disorders is frequently noted, the co-occurrence of parathyroid adenoma and papillary thyroid cancer is exceptionally rare. Furthermore, an ectopic parathyroid adenoma in the retropharyngeal space is exceedingly rare. Therefore, anatomical variations through the utilization of relevant diagnostic tools play a crucial role in guiding decisions pertaining to clinical manifestations, diagnostic methods, surgical interventions, and operative strategies for parathyroid tumors. We present a case of a 51-year-old female patient with papillary thyroid carcinoma in the right thyroid lobe and an ectopic parathyroid adenoma in the retropharyngeal space confirmed through surgical intervention. The elevated preoperative levels of serum calcium and parathyroid hormone, along with low serum phosphate, returned to normal ranges after surgery. This case sheds light on the unusual occurrence of an ectopic parathyroid adenoma in the retropharyngeal region within a thyroid cancer patient, providing valuable insights into the realm of thyroid malignancies.
Journal Article
Potential Role of Hedgehog Pathway in Liver Response to Radiation
2013
Radiation-induced fibrosis constitutes a major problem that is commonly observed in the patients undergoing radiotherapy; therefore, understanding its pathophysiological mechanism is important. The Hedgehog (Hh) pathway induces the proliferation of progenitors and myofibroblastic hepatic stellate cells (MF-HSCs) and promotes the epithelial-to-mesenchymal transition (EMT), thereby regulating the repair response in the damaged liver. We examined the response of normal liver to radiation injury. Male mice were sacrificed at 6 weeks and 10 weeks after exposure to a single dose of 6 Gy and the livers were collected for biochemical analysis. Irradiated (IR) and control mice were compared for progenitors, fibrosis, Hh pathway, and EMT at 6 and 10 weeks post irradiation. Fatty hepatocytes were observed and the expressions of Hh ligand, Indian Hh. were greater in the livers at 6 weeks, whereas expression of another Hh ligand, Sonic Hh, increased at 10 weeks post irradiation. Both Smoothened, Hh receptor, and Gli2, Hh-target gene, were up-regulated at 6 and 10 weeks after irradiation. Accumulation of progenitors (CD44, Pan-cytokeratin, and Sox9) was significant in IR livers at 6 and 10 weeks. RNA analysis showed enhanced expression of the EMT-stimulating factor, tgf-β, in the IR livers at 6 weeks and the upregulation of mesenchymal markers (α-SMA, collagen, N-cadherin, and s100a4), but down-regulation of EMT inhibitors, in IR mouse livers at 6 and 10 weeks. Increased fibrosis was observed in IR mouse livers at 10 weeks. Treatment of mice with Hh inhibitor, GDC-0449, suppressed Hh activity and block the proliferation of hepatic progenitor and expression of EMT-stimulating genes in irradiated mice. Therefore, those results demonstrated that the Hh pathway increased in response to liver injury by radiation and promoted a compensatory proliferation of MF-HSCs and progenitors, thereby regulating liver remodeling.
Journal Article
Holding Area Conceptual Design and Validation for Various Urban Air Mobility (UAM) Operations: A Case Study in Seoul–GyungIn Area
2021
As populations become concentrated in cities, traffic congestion increases, and urban air mobility (UAM) is being considered to face this problem. Accordingly, many institutions and companies around the world are developing UAM vehicles, building infrastructure, and researching flight operating systems. In this study, three holding area concepts have been designed that can control air traffic flows and avoid bad weather conditions when UAM vehicles are operating. These holding areas have been considered to allow UAM vehicles to fly by avoiding collisions with other UAM vehicles or structures such as buildings. After validating the turning radius analysis with existing aircraft, a case study on the holding area concept design for the Seoul–GyungIn area was performed to determine whether UAM vehicles can turn within a narrow radius. It was not possible for winged-type UAM vehicles to turn across the Han River at cruise speed. The holding area concepts and the turning procedure of this study can be used as guidelines when designing UAM corridors or UAM flight routes.
Journal Article
Characteristics of combustion and ash deposition for pulverized coal combustion under various thermal loads: An experimental study in an 80 kWth combustion system
2024
Load-following operations of coal power plants are required to cope with the variability in power generation from renewable energy sources. This study aimed to optimize combustion in coal-fired power plants at low loads by analyzing combustion efficiency, NO
x
emissions, and ash deposition in a boiler. An experiment was conducted by varying the heat input in a bench-scale combustion system. The combustion performance, in terms of the CO concentration in combustion gas and unburned carbon content in ash, degraded during low-load operation. Consequently, the fuel ratio was found to be a key factor for determining the combustion efficiency during low-load operation. The nitrogen content of the fuel was dominant in terms of the NO conversion ratio. The inconsistency in the ash deposition tendency suggested that it was affected more by the composition of minerals than by the amount of ash or total feed rate of ash in coal.
Journal Article