Mitochondrial Ca²⁺ Uptake Relieves Palmitate-Induced Cytosolic Ca²⁺ Overload in MIN6 Cells

Ly, Luong Dai,Ly, Dat Da,Nguyen, Nhung Thi,Kim, Ji-Hee,Yoo, Heesuk,Chung, Jongkyeong,Lee, Myung-Shik,Cha, Seung-Kuy,Park, Kyu-Sang Korean Society for Molecular and Cellular Biology 2020 Molecules and cells Vol.43 No.1

Saturated fatty acids contribute to β-cell dysfunction in the onset of type 2 diabetes mellitus. Cellular responses to lipotoxicity include oxidative stress, endoplasmic reticulum (ER) stress, and blockage of autophagy. Palmitate induces ER Ca²⁺ depletion followed by notable store-operated Ca²⁺ entry. Subsequent elevation of cytosolic Ca²⁺ can activate undesirable signaling pathways culminating in cell death. Mitochondrial Ca²⁺ uniporter (MCU) is the major route for Ca²⁺ uptake into the matrix and couples metabolism with insulin secretion. However, it has been unclear whether mitochondrial Ca²⁺ uptake plays a protective role or contributes to lipotoxicity. Here, we observed palmitate upregulated MCU protein expression in a mouse clonal β-cell, MIN6, under normal glucose, but not high glucose medium. Palmitate elevated baseline cytosolic Ca²⁺ concentration ([Ca²⁺]_i) and reduced depolarization-triggered Ca²⁺ influx likely due to the inactivation of voltage-gated Ca²⁺ channels (VGCCs). Targeted reduction of MCU expression using RNA interference abolished mitochondrial superoxide production but exacerbated palmitate-induced [Ca²⁺]_i overload. Consequently, MCU knockdown aggravated blockage of autophagic degradation. In contrast, co-treatment with verapamil, a VGCC inhibitor, prevented palmitate-induced basal [Ca²⁺]_i elevation and defective [Ca²⁺]_i transients. Extracellular Ca²⁺ chelation as well as VGCC inhibitors effectively rescued autophagy defects and cytotoxicity. These observations suggest enhanced mitochondrial Ca²⁺ uptake via MCU upregulation is a mechanism by which pancreatic β-cells are able to alleviate cytosolic Ca²⁺ overload and its detrimental consequences.

Geological and mineralization characteristics of the Kestanelik epithermal Au-Ag deposit in the Tethyan Metallogenic Belt, NW Turkey

Nilay Gülyüz,Erhan Gülyüz,Zoe K. Shipton,İlkay Kuşcu,Richard A. Lord 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.4

Kestanelik epithermal gold deposit is situated in the Biga Peninsula, which hosts numerous metallic deposits belonging to the Tethyan Metallogenic Belt. In the Biga peninsula the Tethyan Metallogenic Belt is represented by a Neo-Tethyan suture zone. Discovered deposits along the belt are commonly associated with Cenozoic magmatism ranging between 52 and 18 Ma in age, formed due syn- to post-collisional tectonics. In this study, we focus on the deposit-scale geological and mineralization characteristics of Kestanelik in order to determine the formation and evolution of the deposit within the tectono-magmatic history of the Biga Peninsula. We (1) mapped the geology of the deposit area (2) conducted paleostress analyses, (3) observed and examined the macroscopic and petrographical textural, mineralogical and alteration characteristics of the mineralization and (4) interpreted geophysical resistivity survey and geochemical assay data. The stratigraphic age of the Kestanelik deposit, bracketed by cross cutting relations and supported by the geophysical data, is middle Lutetian–early Priabonian which also implies that the deposit has a genetic link with the Cenozoic post-collisional calc-alkaline magmatism. A NE-SW oriented compressional regime determined from the paleostress analyses is consistent with the kinematics of the vein system and is attributed to the collision and further convergence after the closure of the northern branch of the Neo-Tethys Ocean. The fracture system provided structural pathways for the transport of the hydrothermal fluids. The common presence of pseudo-bladed quartz and hydrothermal breccias, and the low total sulphide and base metal contents in the mineralized veins indicate that the Kestanelik is a low sulphidation epithermal-type gold deposit. Boiling, mixing (hypogene oxidation) and supergene enrichment are the likely gold deposition and enrichment processes respectively.

Edge Delamination of Monolayer Transition Metal Dichalcogenides

Ly, Thuc Hue,Yun, Seok Joon,Thi, Quoc Huy,Zhao, Jiong American Chemical Society 2017 ACS NANO Vol.11 No.7

<P>Delamination of thin films from the supportive substrates is a critical issue within the thin film industry. The emergent two-dimensional, atomic layered materials, including transition metal dichalcogenides, are highly flexible; thus buckles and wrinkles can be easily generated and play vital roles in the corresponding physical properties. Here we introduce one kind of patterned buckling behavior caused by the delamination from a substrate initiated at the edges of the chemical vapor deposition synthesized monolayer transition metal dichalcogenides, led by thermal expansion mismatch. The atomic force microscopy and optical characterizations clearly showed the puckered structures associated with the strain, whereas the transmission electron microscopy revealed the special sawtooth-shaped edges, which break the geometrical symmetry for the buckling behavior of hexagonal samples. The condition of the edge delamination is in accordance with the fracture behavior of thin film interfaces. This edge delamination and buckling process is universal for most ultrathin two-dimensional materials, which requires more attention in various future</P>

On H\"older estimates for Cauchy transforms on convex domains in $\mathbb{C}^2$

Ly Kim Ha 대한수학회 2019 대한수학회보 Vol.56 No.4

The main purpose of this paper is to establish H\"older estimates for the Cauchy transform in a class of finite/infinite type convex domains in $\mathbb{C}^2$.

Approaching trauma analgesia using prolonged and novel continuous peripheral nerve blocks - A case report -

Ly Eric,Velamuri Sai,Hickerson William,Hill David M.,Desai Jay,Tsui Ban,Herr Michael,Jones Jerry 대한마취통증의학회 2022 Anesthesia and pain medicine Vol.17 No.1

Background A supraclavicular brachial plexus nerve block provides analgesia for the shoulder, arm, and hand; however, the maximum safe duration for a continuous infusion remains controversial. A novel continuous peripheral nerve block (CPNB) technique combining the Lateral, Intermediate, and Medial femoral cutaneous nerves (termed the ‘LIM’ block) to provide analgesia to the lateral, anterior, and medial cutaneous areas of the thigh while preserving quadriceps strength will also be described in detail here. CaseWe present a complex case in which simultaneous utilization of an unilateral supraclavicular CPNB (5 weeks) and bilateral LIM CPNB (5 days) are successfully performed to provide analgesia for a traumatic degloving injury resulting in multiple surgeries.Conclusions The analgesic plan in this case study eliminated previous episodes of opioid-induced delirium, facilitated participation in recovery, and removed concerns for respiratory depression and chronic opioid use in a patient at particular risk for both issues.

Clinical In Vivo Bio Assay of Glucose in Human Skin by a Tattoo Film Carbon Nano Tube Sensor

Ly, Suw Young,Lee, Chang Hyun The Korean Society of Applied Science and Technolo 2017 한국응용과학기술학회지 Vol.34 No.3

In vivo assay of glucose detection was described using a skin tattoo film electrode (STF), and the probe was made from carbon nano tube paste modification film paper. Here in the square-wave stripping anodic working range obtained of $20-100mgL^{-1}$ within an accumulation time of 0 seconds only in sea water electrolyte solutions of pH 7.0. The relative standard deviations of 50 mg glucose that were observed of 0.14 % (n=12), respectively, using optimum stripping accumulation of 30 sec, the low detection limit (S/N) was pegged at 15.8 mg/L. The developed results can be applied to the detect of in vivo skin sensing in real time. Which confirms the results are usable for in vitro or vivo diagnostic clinical analysis.

Unique characteristics of algal dissolved organic matter and their association with membrane fouling behavior: a review

Ly, Quang Viet,Maqbool, Tahir,Hur, Jin Springer 2017 Environmental Science and Pollution Research Vol. No.

<P>Over the last several decades, the frequent occurrence of algal bloom in drinking water supplies, driven by increasing anthropogenic input and climate change, has posed serious problems for membrane filtration processes, resulting in reduced membrane permeability and increased energy consumption. It is essential to comprehensively understand the characteristics of algal dissolved organic matter (DOM) and the subsequent effects on the filtration processes for better insight into membrane fouling mitigation. Many studies have revealed that algal DOM has displayed unique characteristics distinguished from other sources of DOM with respect to the chemical composition, the structures, and the molecular weight distributions. Algal DOM is considered to be a major obstacle in understanding membrane fouling due to its complicated interactions among dissimilar algal DOM constituents as well as between algal DOM and membrane material matrices. The present review article summarizes (1) recent characterizing methods for algal DOM, (2) environmental factors affecting the characteristics of algal DOM, (3) the discrepancies between algal DOM and other sources of aquatic DOM, particularly terrestrial sources, and (4) potential fouling effects of algal DOM on membrane filtration processes and their associations with algal DOM characteristics. A broad understanding of algal DOM-driven membrane fouling can lead to breakthroughs in efficient membrane filtration processes to treat algal bloom water sources.</P>

Public Safe Assets Determination

Ly Dai Hung 연세대학교 동서문제연구원 2020 Global economic review Vol.49 No.4

On a sample of 150 economies, we characterise the safety of public debt by both ordinary least square and instrument variable regressions. For demand analysis, the public debt is safer for a larger financial market size, a higher financial development level, a lower inflation rate and greater political stability. For supply analysis, the safety of debt improves for a huger debt stock in economies with high income per capita but deteriorates in economies with low income per capita. Cases studies record that, compared with the prediction by economic fundamentals, the investors overestimate the debt safety of China but underestimate that of Greece and Japan.

Antibiotics Assay of Doxycycline in Food System using Stripping Voltammetry

Ly, Suw Young,Lee, Chang Hyun The Korean Society of Applied Science and Technolo 2016 한국응용과학기술학회지 Vol.33 No.4

A voltammetric analysis of doxycycline was developed using DNA immobilized onto a carbon nanotube paste electrode (PE). An anodic peak current was indicated at 0.2 V (versus Ag/AgCl) in a 0.1M $NH_4H_2PO_4$ electrolyte solution. The linear working range of the cyclic and square wave stripping voltammetry was obtained to $1-27ngL^{-1}$ with an accumulation time of 800 s. Final analytical parameters were optimized to be as follows: amplitude, 0.35 V; frequency, 500 Hz; and pH, 5.43. Here detection limit was found to be $0.45ngL^{-1}$, this result can be applied in foods systems and in the biological diagnostics

Spectroscopic measurements of interactions between hydrophobic 1-pyrenebutyric acid and silver colloidal nanoparticles

Ly, Nguyen Hoang,Nguyen, Thanh Danh,Bui, Thanh Lam,Lee, Sangyeop,Choo, Jaebum,Joo, Sang-Woo Elsevier 2017 Colloids and surfaces. A, Physicochemical and engi Vol.518 No.-

<P><B>Abstract</B></P> <P>We compared the adsorption and desorption of 1-pyrenecarboxylic acid (PyC), 1-pyreneacetic acid (PyA), and 1-pyrenebutyric acid (PyB) on silver nanoparticles (AgNPs) via interfacial spectroscopic tools to study the role of the aliphatic units between pyrene and carboxylic group. The negative surface charges of AgNPs at ca. −51mV shifted up to −11mV, after adsorbing hydrophobic pyrene compounds. The three pyrene acid compounds appeared to adsorb onto AgNPs via their carboxylate units by referring to the observation of the broad <I>ν</I>(COO<SUP>−</SUP>) bands at 1380–1410cm<SUP>−1</SUP> in the Raman spectra. X-ray photoelectron spectroscopy (XPS) also supported the CO species in the C<SUB>1s</SUB> region. AgNPs were found to efficiently quench the fluorescence of the three pyrene acid adsorbates. The highest Stern–Volmer constant of PyA may be due to the largest overlap integral with the surface Plasmon absorption band of AgNPs. The butyric unit was expected to lead a stronger binding on Ag, as suggested by density functional theory (DFT) calculations. The adsorbed pyrene acid compounds appeared to be released from AgNPs by thiol-containing glutathione (GSH). PyB with the butyric group exhibited larger quenched fluorescence intensities and smaller released amounts than PyC and PyA in aqueous solutions and A549 cancer cells. Our study will be helpful in designing pyrene-based fluorescence sensors in cellular imaging.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hydrophobic pyrene acids were chemically interacted with Ag nanoparticles. </LI> <LI> 1-Pyrene acids were found to adsorb on silver via the COO<SUP>−</SUP> bonds. </LI> <LI> Fluorescence quenching behaviors of pyrene acids were compared on Ag. </LI> <LI> Glutathione-triggered desorption of pyrene acids were observed in cancer cells. </LI> <LI> 1-Pyrenebutyrate showed stronger binding than 1-pyrenecarboxlyate on Ag. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>