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.

Towards Sympathetic Cooling of Highly Charged Ions by Laser-Cooled Ca+ Ions

Kang-Bin Im,Gi Dong Kim,박영호,신택수 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.7

The long-term goal of the Penning trap system for the heavy ion accelerator named RAON in Korea is to obtain an order of magnitude higher mass accuracy for short-lived rare isotopes. For that purpose, we are developing a sympathetic cooler for highly charged ions by exploiting laser-cooled Ca+ ions. We installed a prototype octagon chamber with a calcium atom source, a Paul trap, and a helical resonator for the high-voltage RF supply. The laser system is composed of three extended cavity diode lasers (423, 397, 866 nm) plus one UV diode laser (375 nm). The optical frequency stabilization setup is made up of a wavelength meter, a multichannel fiber switch and a PXI system with an 8-channel analog output module. After having obtained a resonant ionization signal from the calcium atomic beam, we applied the RF voltage to the trap electrodes and illuminated the cooling lasers at the center of the trap. We successfully observed a laser-cooled ion bunch and a linearly aligned ion string by using imaging optics and an electron multiplying charge coupled device (EMCCD) camera. In addition to the experimental effort, we performed a simulation study for cooling 132Sn10+ ions inside a laser-cooled 40Ca+ Coulomb crystal by using a parallel computation technique.

Accuracy improvement of the most probable point‐based dimension reduction method using the hessian matrix

Kang, Seong Bin,Park, Jeong Woo,Lee, Ikjin John Wiley Sons, Ltd 2017 International journal for numerical methods in eng Vol.111 No.3

<P><B>Summary</B></P><P>This paper proposes a most probable point (MPP)‐based dimension reduction method (DRM) using the Hessian matrix called HeDRM to improve accuracy of reliability analysis in existing MPP‐based DRM methods. Conventional MPP‐based DRMs contain two types of errors: (1) error due to eliminating cross‐terms of a performance function by using the univariate DRM; (2) error because of dependency of an axis direction after a rotational transformation. The proposed method minimizes the aforementioned errors by utilizing the Hessian matrix of a performance function. By performing an orthogonal transformation using the eigenvectors of the Hessian matrix, the cross‐term effect of the performance function is minimized and the axis direction that results in the most accurate calculation is obtained because the Gaussian quadrature points for numerical integration are arranged along the eigenvector directions. In this way, the error incurred by exiting MPP‐based DRMs can be reduced that leads to more accurate probability of failure estimation. In addition, this paper proposes to allocate the Gaussian quadrature points using the magnitude of the eigenvalues of the Hessian matrix. This allocation makes it possible to predetermine the number of function evaluations required to estimate the probability of failure accurately and efficiently. Copyright © 2016 John Wiley & Sons, Ltd.</P>

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.

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

Failure of Cephalosporin Treatment for Bloodstream Infection Caused by Apparently Susceptible Klebsiella pneumoniae which Produced DHA-1β-Lactamase Induced by Clavulanic Acid

Kang, Cheol-In,Pai, Hyungjoo,Kim, Sung Han,Kim, Hong-Bin,Oh, Myoung-don,Kim, Eui-Chong,Choe, Kang-Won 대한감염학회 2004 감염과 화학요법 Vol.36 No.3

목적 : AmpC beta-lactamase를 생성하는 Klebsiella pneumoniae 균주가 보고되고 있으나 이에 대한 적절한 치료 항균제 선택에 제한이 있다. Cephalosporin 내성이 유도되는 형질을 지닌 K. pneumoniae에 의한 균혈증이 2례 발생하였다. 혈액에서 분리된 이 균주들의 내정 기전을 확인하고 항균제 감수성의 특성을 알아보고자 하였다. 방법 : NCCLS 지침에 따라 항균제 감수성 검사와 ESBL 확인 검사를 시행하였다. Isoelectric focusing과 PCR을 이용하여 beta-lactamase characterization을 시행하였다. 결과 : 균주들은 DHA-1 AmpC beta-lactamase를 생성하고 있었고 clavulanic acid에 의해 cephalosporin 내성이 유도되었다. 항균제 감수성 검사 결과 내성이 아닌 광범위 cephalosporin을 투여받았으나 환자들은 치료 실패를 경험하였다. 결론 : 이러한 결과들은 DHA-1을 생성하는 K. pneumoniae에 의한 중증 감염증에 광범위 cephalosporin을 투여하는 것은 감수성이 있는 항균제라 하더라도 적절한 항균제 선택이 아닐 수 있음을 시사한다. Backgroud : The therapeutic option is limited for the infections caused by organisms producing plasmid-mediated AmpC beta-lactamases, increasingly identified worldwide. Two sporadic patients with bacteremia caused by K. pnemniae possessing an unusual inducible β-lactam resistant phenotype were found in a university hospital. Materials & Methods : We conducted antibiotic susceptibility test according to NCCLS guideline. Also, we characterized β-lactamase by isoelectric focusing. Results : DHA-1 gene conferred the resistant phenotype. The patients had experienced treatment failure when treated with extended-spectrum cephalosporin. For the isolates the cephalosporin resistance was induced by clawlanic acid (and cefoxitin). Conclusion : Theses results suggest that the extended-spectrum cephalosporins might not provide optimal therapeutic option for inducible DHA-1-producing K. pneumoniae infection, even when the pathogens are susceptible in vitro.

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.

Use of plant growth-promoting rhizobacteria to control stress responses of plant roots

Kang, Bin-Goo,Kim, Woo-Taek,Yun, Hye-Sup,Chang, Soo-Chul The Korean Society of Plant Biotechnology 2010 Plant biotechnology reports Vol.4 No.3

Ethylene is a key gaseous hormone that controls various physiological processes in plants including growth, senescence, fruit ripening, and responses to abiotic and biotic stresses. In spite of some of these positive effects, the gas usually inhibits plant growth. While chemical fertilizers help plants grow better by providing soil-limited nutrients such as nitrogen and phosphate, overusage often results in growth inhibition by soil contamination and subsequent stress responses in plants. Therefore, controlling ethylene production in plants becomes one of the attractive challenges to increase crop yields. Some soil bacteria among plant growth-promoting rhizobacteria (PGPRs) can stimulate plant growth even under stressful conditions by reducing ethylene levels in plants, hence the term "stress controllers" for these bacteria. Thus, manipulation of relevant genes or gene products might not only help clear polluted soil of contaminants but contribute to elevating the crop productivity. In this article, the beneficial soil bacteria and the mechanisms of reduced ethylene production in plants by stress controllers are discussed.

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>