Impact of scuba diving underwater environment on satisfaction of scuba diving activity and re-participation intention

( Sang Taek Yoon ),( Cheol Sang Hwang ) 한국체육학회 2016 국제스포츠과학 학술대회 Vol.2016 No.1

Purpose: This study intended to identify the impact of resort perceived by the consumers using the scuba diving resort on consumers`` re-participation intention according to the scuba diving underwater environment. The purpose of this can be to provide the strategic basic data for enlargement of scuba diving base and marketing activities by analyzing the scuba diving activity re-participation intention in the consumers experienced the scuba diving. Method: In this study, the questionnaire survey was performed from the qualified divers having scuba diving experience by distributing the questionnaires on the scuba diving underwater environment and scuba diving re-participation intention. The statistical analysis was formed by coding the collected questionnaires using PASW Statistics 18.0 statistic package. The significance level for all statistics was set to 0.05 and for the analysis method used in this study, the frequency analysis to analyze the general characteristics of the individual, exploratory factor analysis to refined the scale of construct in the questionnaire and to verify the convergence validity, Cronbach``s coefficient test to analyze the reliability and the correlation analysis to examine the correlation between the scuba diving underwater environment and the re-participation intention were performed. And finally, the multiple regression analysis was performed the correlation between the scuba diving underwater environment and the re-participation intention. Result: The statistical results analyzed based on the data investigated in this study are as follows. It was represented that the diversity of the underwater point and the activity depth and the diversity of aquatic organism has statistically significant impact on the satisfaction factor by the aquatic organism and out of the sub-factors of the environmental factor, the underwater point and activity depth represented to have significant impact on the satisfaction related to resort facilities. Finally, the factor having statistically significant impact on the re-participation intention was shown as the diversity of activity point and the activity depth. Conclusion and Discussion: First, the sub-factor of the underwater environment represented to have impact on the point, diversity of activity depth and the satisfaction of the aquatic organism. Second, the factor having impact on the scuba diving resort facilities can be the point and the diversity of the activity depth. Third, the re-participation intention after the activity was related to the point and the diversity of activity depth.

Biological Production of an Integrin <i>α</i> v <i>β</i> 3 Targeting Imaging Probe and Functional Verification

Hwang, Mi-Hye,Kim, Jung Eun,Kim, Sang-Yeob,Kalimuthu, Senthilkumar,Jeong, Shin Young,Lee, Sang-Woo,Lee, Jaetae,Ahn, Byeong-Cheol Hindawi Publishing Corporation 2015 BioMed research international Vol.2015 No.-

<P>The aim of the present study is to establish a bacterial clone capable of secreting an integrin <I>α</I>v<I>β</I>3 targeting probe with bioluminescent and fluorescent activities, and to verify its specific targeting and optical activities using molecular imaging. A bacterial vector expressing a fusion of secretory Gaussia luciferase (sGluc), mCherry, and RGD (sGluc-mCherry-RGDX3; GCR), and a control vector expressing a fusion of secretory <I>Gaussia luciferase</I> and mCherry (sGluc-mCherry; GC) were constructed. The GCR and GC proteins were expressed in <I>E. coli</I> and secreted into the growth medium, which showed an approximately 10-fold higher luciferase activity than the bacterial lysate. Successful purification of GCR and GC was achieved using the 6X His-tag method. The GCR protein bound with higher affinity to U87MG cells than CHO cells in confocal microscopy and IVIS imaging, and also showed a high affinity for integrin <I>α</I>v<I>β</I>3 expressing tumor xenografts in an <I>in vivo</I> animal model. An <I>E. coli</I> clone was established to secrete an integrin <I>α</I>v<I>β</I>3 targeting imaging probe with bioluminescent and fluorescent activities. The probe was produced feasibly and at low cost, and has shown to be useful for the assessment of angiogenesis <I>in vitro</I> and <I>in vivo</I>.</P>

Performance Variation According to Device Structure and the Source/Drain Metal Electrode of a-IGZO TFTs

Sang Ho Rha,Jisim Jung,Yoonsoo Jung,Yoon Jang Chung,Un Ki Kim,Eun Suk Hwang,Byoung Keon Park,Tae Joo Park,Jung-Hae Choi,Cheol Seong Hwang IEEE 2012 IEEE transactions on electron devices Vol.59 No.12

<P>The transmission-line method (TLM) was adopted to clarify the causes of device performance variation according to the source/drain metal electrode and device structure of a thin-film transistor using an amorphous indium-gallium-zinc-oxide channel. Using the TLM, the channel characteristics independent of contact resistance were extracted for the two different contact metals, i.e., Ti and Mo. Based on these results, the mobility characteristics were compared in terms of device scaling and contact structure in the source/drain overlap region. In addition, the transport characteristics according to the contact structure of the source/drain metal electrode were investigated in detail and reproduced using the simulation model.</P>

Auranofin, an inhibitor of thioredoxin reductase, induces apoptosis in hepatocellular carcinoma Hep3B cells by generation of reactive oxygen species

Hwang-Bo, Hyun,Jeong, Jin-Woo,Han, Min Ho,Park, Cheol,Hong, Su-Hyun,Kim, Gi-Young,Moon, Sung-Kwon,Cheong, Jaehun,Kim, Wun-Jae,Yoo, Young Hyun,Choi, Yung Hyun 'AEPress, s.r.o.' 2017 General physiology and biophysics Vol.36 No.2

Role of Electronic Perturbation in Stability and Activity of Pt-Based Alloy Nanocatalysts for Oxygen Reduction

Hwang, Seung Jun,Kim, Soo-Kil,Lee, June-Gunn,Lee, Seung-Cheol,Jang, Jong Hyun,Kim, Pil,Lim, Tae-Hoon,Sung, Yung-Eun,Yoo, Sung Jong American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.48

<P>The design of electrocatalysts for polymer electrolyte membrane fuel cells must satsify two equally important fundamental principles: optimization of electrocatalytic activity and long-term stability in acid media (pH <1) at high potential (0.8 V). We report here a solution-based approach to the preparation of Pt-based alloy with early transition metals and realistic parameters for the stability and activity of Pt(3)M (M = Y, Zr, Ti, Ni, and Co) nanocatalysts for oxygen reduction reaction (ORR). The enhanced stability and activity of Pt-based alloy nanocatalysts in ORR and the relationship between electronic structure modification and stability were studied by experiment and DFT calculations. Stability correlates with the d-band fillings and the heat of alloy formation of Pt(3)M alloys, which in turn depends on the degree of the electronic perturbation due to alloying. This concept provides realistic parameters for rational catalyst design in Pt-based alloy systems.</P>

Simultaneous regeneration of calcium lactate and cellulose into PCL nanofiber for biomedical application

Hwang, T.I.,Kim, J.I.,Joshi, Mahesh Kumar,Park, Chan Hee,Kim, Cheol Sang Elsevier 2019 Carbohydrate Polymers Vol.212 No.-

<P><B>Abstract</B></P> <P>Synthetic polymers are easy to process and have excellent mechanical properties but low wettability and poor cell compatibility limit their applications in tissue scaffolding. In this study, a facile procedure was established to regenerate cellulose and calcium lactate (CaL) into a polycaprolactone (PCL) nanofibrous scaffold for tissue engineering applications. Briefly, varying amounts of lactic acid (LA) was mixed with the blend of PCL and cellulose acetate (CA) solutions and electrospun to fabricate an optimal composite PCL/CA/LA fibrous membrane. Later on, as-prepared membranes were treated with calcium hydroxide solution. This process simultaneously converted CA and LA contents into Cellulose and CaL, respectively. <I>In situ</I> regeneration of Cellulose and CaL into the composite fiber remarkably enhanced the biological and physicochemical properties of the composite fiber. This work provides a novel dual-channel strategy for simultaneous regeneration of biopolymer and bioactive molecule into the PCL nanofiber for regenerative medicine and tissue engineering applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The PCL/CA/LA fiber mat was simply obtained by conventional electrospinning method. </LI> <LI> The as-fabricated composite membrane was simply treated with CaOH<SUB>2</SUB>. </LI> <LI> Calcium lactate (CaL) was synthesized by reaction between LA and CaOH<SUB>2</SUB>. </LI> <LI> Cellulose acetate (CA) content was deacetylated into cellulose (CE). </LI> <LI> CE and CaL were simultaneously generated in a one-step post-electrospinning process. </LI> </UL> </P>

Phellinus linteus Extract Regulates Macrophage Polarization in Human THP-1 Cells

Sang-Yull Lee(이상률),Sul-Gi Park(박슬기),Sun-Nyoung Yu(유선녕),Ji-Won Kim(김지원),You-Lim Hwang(황유림),Dong-Seob Kim(김동섭),Soon-Cheol Ahn(안순철) 한국생명과학회 2020 생명과학회지 Vol.30 No.2

대식세포는 특성에 따라 크게 classically activated macrophages (M1-phenotype macrophages)와 alternatively activated macrophages (M2-phenotype macrophages) 두 가지의 형태로 나눌 수 있다. M1 대식세포의 경우 직·간접적으로 병원체, 감염된 조직 및 암세포 등을 제거하는 능력을 가진 반면, M2 대식세포의 경우 항염증 반응을 동반한 손상된 세포 조직의 복구 및 세포외기질의 생성에 관여하고 있다. 본 연구에서는 상황버섯 열수추출물을 합성 흡착제인 Diaion HP-20에 통과시켜 소수성 물질을 제거한 시료(PLEP)을 이용하여 인간 유래 THP-1 단핵구 세포주의 염증성 혹은 항염증성 분극화 특성을 알아보았다. 먼저 PLEP 자체의 단핵구 세포에 대한 세포독성을 확인한 결과, 고농도의 300 μg/ml에서 세포독성이 확인되지 않았다. 한편 세포의 형태학적 변화를 확인한 결과, PLEP의 농도가 증가함에 따라 M1- phenotype 대식세포와 유사한 flatted and branched 형태가 증가하였다. 대식세포로 분화시킨 THP-1 세포주에 PLEP를 처리한 후, M1 대식세포 분극화 관련 유전자인 TNFα, IL-1β, IL-6, IL-8, CXCL10, CCR7과 M2-분극화 관련 유전자인 MRC-1, DC-SIGN, CCL17, CCL22의 유전자 발현량을 조사하여 분극화 양상을 알아보았다. 그 결과, M1-분극화 관련 유전자들은 PLEP 농도 의존적으로 증가하였지만, M2-분극화 관련 유전자들은 반대로 감소하였다. 또한 ELISA assay를 통하여 M1 분극화 관련 cytokine인 TNFα, IL-1β, IL-6의 발현량이 유전자의 발현량과 동일하게 증가하였다. 이러한 cytokine들의 분비를 촉진시키는 MAPK signaling 또한 PLEP의 농도가 증가함에 따라 촉진되었고 염증성 cytokine과 관련된 전사인자 NF-κB의 활성화도 증가하였다. 따라서 PLEP는 인간 유래 THP-1 세포주에서의 M1 대식세포 분극화를 통해 염증 반응을 유발하는 것으로 확인되어 염증을 촉진하는 천연물질로 이용할 수 있을 것으로 전망된다. Macrophages are initiators for regulating a host’s defenses to eliminate pathogens and trigger tissue repair. Macrophages are classified into two types: classically (M1) activated macrophages and alternatively (M2) activated macrophages. M1-phenotype macrophages directly or indirectly kill infectious organisms and tumor cells via pro-inflammatory responses, whereas M2-phenotype macrophages remodel wounded tissue through anti-inflammatory responses. In this paper, we investigated how Phellinus linteus hot water extract passed from Diaion HP-20 resin (PLEP) regulates polarization of M1-like or M2-like macrophages in human THP-1 cells. PLEP did not have cytotoxicity at a high concentration of 300 μg/ml. We observed morphological alteration of the THP-1 cells, which are stimulated by PLEP, LPS/INF-γ (M1 stimulators) or IL-4/IL13 (M2 stimulators). PLEP exposure induced morphology contiguous with LPS/INF-γ. qPCR was also performed to determine whether PLEP influences M1 or M2 polarization-related genes. M1-phenotype macrophage–specific genes, such as TNF-α, IL-1β, IL-6, IL-8, CXCL10 and CCR7, were enhanced by PLEP in a dose-dependent manner similar to LPS/INF-γ. Conversely, M2-phenotype–specific genes, such as MRC-1, DC-SIGN, CCL17 and CCL22, were suppressed by PLEP. PLEP also significantly up-regulated secretory inflammation cytokines related to M1 polarization of macrophages, including TNFα, IL-1β and IL-6, which was similar to the gene expression. Further, MAPK and NF-κB signaling were increased by treatment with PLEP, resulting in enhancement of cytokine secretion. PLEP might therefore be used as a promising booster of pro-inflammatory responses through M1 polarization of human THP-1 cells.

A 16-Year Single Center Experience of Resected 2029 Pancreatic Ductal Adenocarcinoma

Sang Hyun Shin,Song Cheol Kim,Dae Wook Hwang,Ki Byung Song,Jae Hoon Lee,Bong Jun Kwak,Seong-Ryong Kim,Jaewoo Kwon,Chung Hyeun Ma,Seunghyun Hwang,Kwang-Min Park,Young-Joo Lee 대한외과학회 2016 대한외과학회 학술대회 초록집 Vol.2016 No.11

A Study on Food Safety in Chocolates and Candies: Pb, Tar Colors and Microbial Contaminants

Sung-kyu Park,Chae-man Choi,Bu-cheol Choi,Jae-eun Kwak,Seon-ok Jung,Min-jeong Kim,In-sook Hwang 한국분석과학회 2023 학술대회논문집 Vol.2023 No.5

Investigation of detection wavelength of Quantum Well Infrared-Photodetector

Sung Ho Hwang,Jae Gu Lim,Jin Dong Song,Jae Cheol Shin,Du Chang Heo,최원준 한국진공학회 2015 Applied Science and Convergence Technology Vol.24 No.6

We report on GaAs/AlGaAs quantum well infrared photodetectors (QWIPs) that can cover the spectral range of 3.6-25 μm. One advantage of the GaAs QWIPs is the wavelength tenability as a function of their structural parameters. We have performed a systematic calculation on the detection wavelength of a typical GaAs/AlxGa1-xAs multi-quantum-well photodetector, with the aluminum mole fraction (x) of AlxGa1-xAs barrier in the range of 0.15- 0.43 and the quantum-well width range from 30 to 60 Å. Design and fabrication of a QWIP based on GaAs/Al0.23Ga0.77As structure with 37 Å-thick well width has been carried out. The calculated operation wavelength of the QWIP is in a good agreement with the experimental data taken by photo response and activation energy calculation from thermal quenching of integrated photoluminescence.