Paleostress of the Joseon and Pyeongan Supergroups in South Korea using the New Calcite Strain Gauge (NCSG)

( Bo An Jang ),( Chin Surk Ko ),( Jung Han Kim ),( Cheong Bin Kim ),( Seong Seung Kang2 ) 대한지질공학회 2014 지질공학 Vol.24 No.3

Limestone bodies under the tectonic environment have experienced various tectonic processes, and also changed the stress state. In this study, calcite twins found in limestones of the Joseon Supergroup and Pyeongan Supergroup in the northeastern part of the Ogcheon Belt, South Korea were measured, then the paleostress (i.e., the maximum shortening axis) was reconstructed using the new calcite strain gauge (NCSG) technique. The average twin thickness and average twin intensity increase as the total twin strain increases. We utilize the appearance of twins, the average twin thickness and average twin intensity, and the total twin strain to estimate that the observed calcite twins were produced at temperatures of < 200oC in the Joseon Supergroup and 170oC in the Pyeongan Supergroup. In the Joseon Supergroup, the dominant direction of the maximum shortening axis WNW-ESE to NW-SE; NE-SW shortening is also observed. The maximum shortening axes in the Pyeongan Supergroup are oriented NW-SE and NE-SW. The NE-SW direction of maximum shortening is associated with the occurrence of the Songrim orogeny of the Paleozoic to Early Jurassic, and the NW-SE direction of maximum shortening correlates to the Daebo orogeny of the Early Jurassic to Late Jurassic. It is thus concluded that the paleostress across the study area changed from NE-SW to NW-SE during the Mesozoic.

Changes in hippocalcin expression in cortical neurons and glial cells by epigallocatechin gallate administration in an animal model of stroke

Ju-Bin Kang(Ju-Bin Kang),Dong-Ju Park(Dong-Ju Park),Jae-You Kim(Jae-You Kim),Hyeun-Gyoung(Hyeun-Gyoung ),Phil-Ok Koh(Phil-Ok Koh) 한국예방수의학회 2023 예방수의학회지 Vol.47 No.2

Ischemic stroke causes brain damage and neuronal cell death by depriving oxygen and nutrients and releasing excessive levels of glutamate and intracellular calcium. Epigallocatechin gallate (EGCG) is a polyphenolic compound present in green tea. It has antioxidant, anti-inflammatory, and neuroprotective effects. Hippocalcin is a calcium binding protein that regulates calcium concentration, neuronal differentiation, neuronal excitability, and neuronal cell death. In this study, we investigated whether EGCG regulates the expression of hippocalcin in neurons and astrocytes after focal cerebral ischemia. Cerebral ischemia was induced by meddle cerebral artery occlusion (MCAO). EGCG (50 mg/kg) or PBS was injected into the abdominal cavity just before MCAO surgery. Neurobehavioral tests were performed to evaluate the effect of EGCG on neurological behavioral deficits 24 h after MCAO surgery. Immunofluorescence staining was performed to evaluate the positive response to hippocalcin in the cerebral cortex after MCAO surgery. We also detected the positive reactions of neuronal nuclear protein (NeuN) and glial fibrillary acidic protein (GFAP) as markers of neuron and astrocyte, respectively. MCAO caused severe neurological impairment and EGCG treatment attenuated these impairments. MCAO damage reduced the number of NeuN-positive cells and increased the number of GFAP-positive cells. This result indicates a decrease in neurons and an increase in astrocytes. However, EGCG alleviated these changes caused by MCAO damage. MCAO reduced the number of hippocalcin-positive cells in neurons and astrocytes, and EGCG treatment attenuated these reductions. Hippocalcin exerts neuroprotective effect through regulating intracellular calcium concentration. In conclusion, EGCG regulates the expression of hippocalcin in neurons and astrocytes and has neuroprotective effects in focal cerebral ischemia.

UHPLC-ESI-qTOF-MS Analysis of Cyclopeptide Alkaloids in the Seeds of Ziziphus jujuba var. spinosa

Kang, Kyo Bin,Jang, Dae Sik,Kim, Jinwoong,Sung, Sang Hyun Korean Society for Mass Spectrometry 2016 Mass spectrometry letters Vol.7 No.2

An UHPLC-ESI-qTOF-MS analytical method was developed for cyclopeptide alkaloids in the seeds of Ziziphus jujuba var. spinosa (Semen Ziziphi Spinosae), which is a commonly used herb in Chinese and Korean traditional medicines. Considering the basicity of cyclopeptide alkaloids, a specific separation method was developed for an UHPLC system. The compounds were detected by DAD and ESI-qTOF-MS, and their fragmentation patterns were also acquired by MS^E technologies. Peak-picking of major compounds was performed with nine previously isolated compounds and two reference standard compounds. Tandem MS fragmentation behaviors of type-Ia and -Ib cyclopeptide alkaloids were investigated with the acquired data to develop a strategy for dereplication of other cyclopeptide alkaloid compounds in Z. jujuba var. spinosa. Two more cyclopeptide alkaloids were tentatively identified with UHPLC-ESI-qTOF-MS using this method.

국내 코로나19 판데믹 기간 발생한 입원을 요하는 소아청소년 지역사회폐렴의 원인과 위험 인자

Kang Hae Min,Song Seung Ha,Ahn Bin,Park Ji Young,Kang Hyunmi,Kwak Byung Ok,Kim Dong Hyun,Lee Joon Kee,Choi Soo-Han,Choi Jae Hong,Choi Eun Hwa,Yun Ki Wook 대한소아감염학회 2023 Pediatric Infection and Vaccine Vol.30 No.1

Purpose: This study aimed to identify the etiology and risk factors of community-acquired pneumonia (CAP) requiring hospitalization in Korean children during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Clinical information of children admitted with CAP to Seoul National University Children’s Hospital (SNUCH) between January 1, 2021, and February 28, 2022, was retrospectively collected and analyzed. In addition, the etiologic diagnosis and demographic data of children with CAP who were discharged at the other seven hospitals between January and February 2022 were collected. Pneumonia was diagnosed using strict criteria comprising clinical symptoms, physical examination findings, and chest radiographic findings. Results: Among 91 children hospitalized with CAP at SNUCH during the 14-month period, 68.4% were aged <5 years and 79.1% had underlying diseases. Among the 95 CAP cases, respiratory assistance was required in 70.5%, and the use of a ventilator was required in 20.0%. A total of five patients expired, all of whom were either immunocompromised or had underlying neurological diseases. Neurological diseases and immunosuppression were significantly correlated with respiratory assistance (P=0.003) and death (P=0.014). A total of 55% of the detected respiratory pathogens were viruses, the most common of which was rhinovirus at 35.9%. Among the 169 children hospitalized for CAP at the eight institutions, ≥1 respiratory virus was detected in 92.3%, among which respiratory syncytial virus (79.8%) was the most prevalent. Conclusions: Even during the COVID-19 pandemic, Korean children were hospitalized with CAP caused by seasonal respiratory viral pathogens. Although atypical and pyogenic bacteria were not detected, continuous clinical monitoring and further prospective studies should be conducted.

Prediction of tyrosinase inhibitory activities from HPLC chromatograms of Morus alba root bark extracts

KANG Kyo Bin,KIM Tae Bum,MOON Eunhye,KIM Seung Hyun,KIM Jinwoong,SUNG Sang Hyun 大韓藥學會 2012 大韓藥學會 總會 및 學術大會 Vol.2012 No.1

Coin Drop Simulation based on Smoothed Particles Hydrodynamics

Kang, Han-bin,Pack, In-seok,Song, Ju-han,Lee, Dong-ug,Park, Min-hyeok,Lee, Seok-soon The Society for Aerospace System Engineering 2013 항공우주시스템공학회지 Vol.7 No.1

Smoothed Particle Hydrodynamics(SPH) method uses a grid of historical analysis and is not Lagrangian particles using the grid method. The Navier-Stokes equations were used to solve the viscous flow of the non-compressed. In this study, the numerical analysis of the three-dimensional Coin Drop Simulation using SPH method was performed, and the analysis results are compared with experimental results, and a similar behavior can be seen. The commercial program used was Abaqus/Explicit. SPH method to reduce the error by comparing the existing flow analysis or interpretation of the continuing research is needed in the future. That will enable real-time analysis of material obtained as a result of these numerical simulations similar to the actual flow phenomena, depending on the development of computer graphics technology to show visually. As a result, this method can be applied to the analysis fluid - structure interaction problems in a variety of fields.

The Usefulness of Surgical Treatment in Slow-Flow Vascular Malformation Patients

Kang, Gyu Bin,Bae, Yong Chan,Nam, Su Bong,Bae, Seong Hwan,Sung, Ji Yoon Korean Society of Plastic and Reconstructive Surge 2017 Archives of Plastic Surgery Vol.44 No.4

Background Many difficulties exist in establishing a treatment plan for slow-flow vascular malformation (SFVM). In particular, little research has been conducted on the surgical treatment of SFVMs. Thus, we investigated what proportion of SFVM patients were candidates for surgical treatment in clinical practice and how useful surgical treatment was in those patients. Methods This study included 109 SFVM patients who received care at the authors' clinic from 2007 to 2015. We classified the patients as operable or non-operable, and analyzed whether the operability and the extent of the excision varied according to the subtype and location of the SFVM. Additionally, we investigated complications and self-assessed satisfaction scores. Results Of the 109 SFVM patients, 59 (54%) were operable, while 50 (46%) were non-operable. Total excision could be performed in 44% of the operable SFVM patients. Lymphatic malformations were frequently non-operable, while capillary malformations were relatively operable (P=0.042). Total excision of venous malformations could generally be performed, while lymphatic malformations and combined vascular malformations generally could only undergo partial excision (P=0.048). Complications occurred in 11% of the SFVM patients who underwent surgery; these were minor complications, except for 1 case. The average overall satisfaction score was 4.19 out of 5. Conclusions Based on many years of experience, we found that approximately half (54%) of SFVM patients were able to undergo surgery, and around half (44%) of those patients were able to fully recover after a total excision. Among the patients who underwent surgical treatment, high satisfaction was found overall and relatively few complications were reported.

Creep Behaviors of CrMnFeCoNi High Entropy Alloy at Intermediate Temperatures

Kang, You Bin,Lee, Kap Ho,Hong, Sun Ig Trans Tech Publications, Ltd. 2017 Key Engineering Materials Vol.737 No.-

<P>In this study, creep properties and fracture behavior of CrMnFeCoNi high entropy alloy (HEA) were studied at intermediate temperatures. The invert-type transient primary creep behaviors were observed in CrMnFeCoNi high entropy alloy. Creep behaviors of HEA are similar to those of class I solid solution alloys. The transient creep curves upon increase of stress by 5MPa in the steady state creep region did not change much except the sudden strain increase. And, no decrease of creep rate was observed upon increase of stress. Instead, the slightly invert transient creep or almost straight creep curves were observed, supporting the high friction stress. CrMnFeCoNi high entropy alloy has a stress exponent of 3.75 and the creep activation energy was calculated to be 278KJ/mole. The fracture strain increased from 1.3 to 1.6 with the decrease of stress from 96 MPa to 48MPa. The lower stress exponent along with the invert type primary creep curves strongly suggest that the creep of CrMnFeCoNi high entropy alloy at 600°C~650°C occurs by a glide controlled process.</P>

Catechin-Bound Ceanothane-Type Triterpenoid Derivatives from the Roots of <i>Zizyphus jujuba</i>

Kang, Kyo Bin,Kim, Hyun Woo,Kim, Jung Wha,Oh, Won Keun,Kim, Jinwoong,Sung, Sang Hyun American Society of Pharmacognosy 2017 Journal of natural products Vol.80 No.4

<P>Three unprecedented ceanothane-type triterpenoids, ent-epicatechinoceanothic acid A (1), ent-epicatechinoceanothic acid B (2), and epicatechino-3-deoxyceanothetric acid A (3), containing C-C bond linkages with catechin moieties, were isolated from the roots of Zizyphus jujuba. Their chemical structures, including absolute configurations, were established by spectroscopic analysis and calculation of their ECD spectra. A possible biogenetic pathway for C-C bond formation between the catechin and the triterpenoid moieties is presented. Compound 1 was evaluated for its antiproliferalive activity on HSC-T6 hepatic stellate cells.</P>

Chemical and genomic diversity of six <i>Lonicera</i> species occurring in Korea

Kang, Kyo Bin,Kang, Shin-Jae,Kim, Mi Song,Lee, Dong Young,Han, Sang Il,Kim, Tae Bum,Park, Jee Young,Kim, Jinwoong,Yang, Tae-Jin,Sung, Sang Hyun Elsevier 2018 Phytochemistry Vol.155 No.-

<P><B>Abstract</B></P> <P> <I>Lonicera</I> spp. (Caprifoliaceae) are important not only as a common medicinal herb in East Asia but also as one of the most problematic invasive species in North America. In the present study, we performed a systemic analysis of genomic and chemical diversity among six <I>Lonicera</I> species occurring in Korea, <I>L. japonica</I>, <I>L. maackii</I>, <I>L. insularis</I>, <I>L. sachalinensis</I>, <I>L. praeflorens</I>, and <I>L. vesicaria</I>, using chloroplast DNA whole genome shotgun (WGS) sequencing and LC–MS analyses. The phylogenetic and phylochemical relationships did not coincide with each other, but partial consistency could be found among them. InDel-based cDNA marker for authentication was developed based on the genome sequences. Flavonoids, iridoids, and organic acids were identified in the LC–MS analyses, and their inter-species distribution and localization were also revealed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Phylogeny between six <I>Lonicera</I> species was supposed based on chloroplast genome sequences. </LI> <LI> Specialized metabolites were profiled and compared by LC–MS. </LI> <LI> Partial consistency was found between genomic and chemical phylogeny. </LI> <LI> An Indel-based DNA barcode was developed for authentication of plants. </LI> <LI> Difference in chemotypes was suggested to be caused by ecological roles of iridoids. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>