Laser Thinning for Monolayer Graphene Formation: Heat Sink and Interference Effect

Han, Gang Hee,Chae, Seung Jin,Kim, Eun Sung,Gü,neş,, Fethullah,Lee, Il Ha,Lee, Sang Won,Lee, Si Young,Lim, Seong Chu,Jeong, Hae Kyung,Jeong, Mun Seok,Lee, Young Hee American Chemical Society 2011 ACS NANO Vol.5 No.1

<P>Despite the availability of large-area graphene synthesized by chemical vapor deposition (CVD), the control of a uniform monolayer graphene remained challenging. Here, we report a method of acquiring monolayer graphene by laser irradiation. The accumulation of heat on graphene by absorbing light, followed by oxidative burning of upper graphene layers, which strongly relies on the wavelength of light and optical parameters of the substrate, was <I>in situ</I> measured by the G-band shift in Raman spectroscopy. The substrate plays a crucial role as a heat sink for the bottom monolayer graphene, resulting in no burning or etching. Oscillatory thinning behavior dependent on the substrate oxide thickness was evaluated by adopting a simple Fresnel’s equation. This paves the way for future research in utilizing monolayer graphene for high-speed electronic devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2011/ancac3.2011.5.issue-1/nn1026438/production/images/medium/nn-2010-026438_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn1026438'>ACS Electronic Supporting Info</A></P>

The Korean Developmental State Model and the Saemaul Movement as National Development Strategies: Are They Applicable to Latin American Nations?

( Chae Won Lim ),( Myung Rok Do ),( Min Han Kim ) 한국정책학회 2013 한국정책학회 추계학술발표논문집 Vol.2013 No.-

Effect of the Modified Live Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Vaccine on European and North American PRRSV Shedding in Semen from Infected Boars

Han, Kiwon,Seo, Hwi Won,Shin, Jeoung Hwa,Oh, Yeonsu,Kang, Ikjae,Park, Changhoon,Chae, Chanhee American Society for Microbiology 2011 CLINICAL AND VACCINE IMMUNOLOGY Vol.18 No.10

<B>ABSTRACT</B><P>The objective of the present study was to compare the effects of the modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (Ingelvac PRRS MLV; Boehringer Ingelheim Animal Health, St. Joseph, MO) on European and North American PRRSV shedding in the semen of experimentally infected boars. The boars were randomly divided into six groups. Vaccinated boars shed the North American PRRSV at the rate of 10<SUP>0.1</SUP>to 10<SUP>1.0</SUP>viral genome copies per ml and 3.63 to 10<SUP>1.1</SUP>50% tissue culture infective doses (TCID50)/ml, respectively, in semen, whereas nonvaccinated boars shed the North American PRRSV at the rate of 10<SUP>0.2</SUP>to 10<SUP>4.7</SUP>viral genome copies per ml and 1.14 to 10<SUP>3.07</SUP>TCID50/ml, respectively, in semen. Vaccinated boars shed the European PRRSV at the rate of 10<SUP>0.1</SUP>to 10<SUP>4.57</SUP>viral genome copies per ml and 1.66 to 10<SUP>3.10</SUP>TCID50/ml, respectively, in semen, whereas nonvaccinated boars shed the European PRRSV at the rate of 10<SUP>0.3</SUP>to 10<SUP>5.14</SUP>viral genome copies per ml and 1.69 to 10<SUP>3.17</SUP>TCID50/ml, respectively, in semen. The number of genomic copies of the European PRRSV in semen samples was not significantly different between vaccinated and nonvaccinated challenged European PRRSV boars. The present study demonstrated that boar vaccination using commercial modified live PRRSV vaccine was able to decrease subsequent shedding of North American PRRSV in semen after challenge but was unable to decrease shedding of European PRRSV in semen after challenge.</P>

Deoxypodophyllotoxin Inhibits Cell Growth and Induces Apoptosis by Blocking EGFR and MET in Gefitinib-Resistant Non-Small Cell Lung Cancer

( Han Sol Kim ),( Ha-na Oh ),( Ah-won Kwak ),( Eunae Kim ),( Mee-hyun Lee ),( Ji-hye Seo ),( Seung-sik Cho ),( Goo Yoon ),( Jung-il Chae ),( Jung-hyun Shim ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.4

As one of the major types of lung cancer, non-small cell lung cancer (NSCLC) accounts for the majority of cancer-related deaths worldwide. Treatments for NSCLC includes surgery, chemotherapy, and targeted therapy. Among the targeted therapies, resistance to inhibitors of the epidermal growth factor receptor (EGFR) is common and remains a problem to be solved. MET (hepatocyte growth factor receptor) amplification is one of the major causes of EGFR-tyrosine kinase inhibitor (TKI) resistance. Therefore, there exists a need to find new and more efficacious therapies. Deoxypodophyllotoxin (DPT) extracted from Anthriscus sylvestris roots exhibits various pharmacological activities including anti-inflammation and anti-cancer effects. In this study we sought to determine the anti-cancer effects of DPT on HCC827GR cells, which are resistant to gefitinib (EGFR-TKI) due to regulation of EGFR and MET and their related signaling pathways. To identify the direct binding of DPT to EGFR and MET, we performed pull-down, ATP-binding, and kinase assays. DPT exhibited competitive binding with ATP against the network kinases EGFR and MET and reduced their activities. Also, DPT suppressed the expression of p-EGFR and p-MET as well as their downstreat proteins p-ErbB3, p-AKT, and p-ERK. The treatment of HCC827GR cells with DPT induced high ROS generation that led to endoplasmic-reticulum stress. Accordingly, loss of mitochondrial membrane potential and apoptosis by multi-caspase activation were observed. In conclusion, these results demonstrate the apoptotic effects of DPT on HCC827GR cells and signify the potential of DPT to serve as an adjuvant anti-cancer drug by simultaneously inhibiting EGFR and MET.

Isorhamnetin Protects Human Keratinocytes against Ultraviolet B-Induced Cell Damage

Han, Xia,Piao, Mei Jing,Kim, Ki Cheon,Hewage, Susara Ruwan Kumara Madduma,Yoo, Eun Sook,Koh, Young Sang,Kang, Hee Kyoung,Shin, Jennifer H,Park, Yeunsoo,Yoo, Suk Jae,Chae, Sungwook,Hyun, Jin Won The Korean Society of Applied Pharmacology 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.4

Isorhamnetin (3-methylquercetin) is a flavonoid derived from the fruits of certain medicinal plants. This study investigated the photoprotective properties of isorhamnetin against cell damage and apoptosis resulting from excessive ultraviolet (UV) B exposure in human HaCaT keratinocytes. Isorhamnetin eliminated UVB-induced intracellular reactive oxygen species (ROS) and attenuated the oxidative modification of DNA, lipids, and proteins in response to UVB radiation. Moreover, isorhamnetin repressed UVB-facilitated programmed cell death in the keratinocytes, as evidenced by a reduction in apoptotic body formation, and nuclear fragmentation. Additionally, isorhamnetin suppressed the ability of UVB light to trigger mitochondrial dysfunction. Taken together, these results indicate that isorhamnetin has the potential to protect human keratinocytes against UVB-induced cell damage and death.

Effects of Mental Health Support on the Grief of Bereaved People Caused by Sewol Ferry Accident

Han, Hyesung,Noh, Jin-Won,Huh, Hyu jung,Huh, Seung,Joo, Ji-Young,Hong, Jin Hyuk,Chae, Jeong-Ho The Korean Academy of Medical Sciences 2017 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.32 No.7

<P>Few studies have assessed the overall effects of multi-centered, complicated mental health support on the grief process. This study investigated the broader influence of mental health support provided practically to the bereaved family on the severity of complicated grief. Ninety-three bereaved family members of the Sewol ferry accident were recruited. Severity of complicated grief, post-traumatic stress disorder (PTSD) and depressive disorder was assessed through self-reporting questionnaire, inventory of complicated grief (ICG), PTSD Check List-5 (PCL-5) and Patient Health Questionnaire-9 (PHQ-9). We also included demographic, socioeconomic, health-related variables, and Functional Social Support Questionnaire (FSSQ), which affect the ICG score. Participants were divided into 4 groups based on the experience of psychotherapy or psychiatry clinic service before the accident and mental health support after the disaster. In univariate analysis, these 4 groups showed a significant difference in the mean ICG score (<I>P</I> = 0.020). Participants who received mental health support only after the Sewol ferry accident (group 2) showed a lower mean ICG score than those who received neither psychotherapy or psychiatry clinic service before the disaster nor mental health support after the accident (group 4). There was no significant correlation between the ICG score and other variables except for subjective health status measured 1 month after the disaster (<I>P</I> = 0.005). There was no significant difference in PCL-5 (<I>P</I> = 0.140) and PHQ-9 scores (<I>P</I> = 0.603) among groups, respectively. In conclusion, mental health support significantly reduced the severity of grief only in those participants who had not received any psychotherapy or psychiatry clinic service before the accident.</P>

Strong hydrophobizer: laterally chemisorbed low-molecular-weight polydimethylsiloxane

Chae, Soo Sang,Oh, Jin Young,Park, Jee Ho,Choi, Won Jin,Han, Jeong Hwan,Lee, Jeong-O,Baik, Hong Koo,Lee, Tae Il The Royal Society of Chemistry 2015 Chemical communications Vol.51 No.27

<P>We introduce a siloxane chain-based hydrophobizer that exhibits superior thermal and chemical stability compared to the conventional hydrophobizing silane agent under conditions of over 300 °C and pH 2–13. To demonstrate the capability of the siloxane chain-based hydrophobizer to serve as a highly robust chemical surface modifier, we present two applications: the formation of fine metal nanoparticles with a narrow size distribution by thermal aggregation of a metal thin film and the selective deposition of a ruthenium thin film by atomic layer deposition.</P> <P>Graphic Abstract</P><P>We introduce a siloxane chain-based hydrophobizer that exhibits superior thermal and chemical stability compared to the conventional hydrophobizing silane agent under conditions of over 300 °C and pH 2–13. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5cc00066a'> </P>

Vaccination of sows against type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) before artificial insemination protects against type 2 PRRSV challenge but does not protect against type 1 PRRSV challenge in late gestation

Han, Kiwon,Seo, Hwi Won,Park, Changhoon,Chae, Chanhee BioMed Central 2014 VETERINARY RESEARCH Vol.45 No.-

<P>The objective of the present study was to determine the effects of the commercially available type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)-based modified live vaccine against type 1 and type 2 PRRSV challenge in pregnant sows. Half of the sows in the study were vaccinated with a type 2 PRRSV-based vaccine 4 weeks prior to artificial insemination while the other half remained non-vaccinated. Sows were then challenged intranasally with type 1 or type 2 PRRSV at 93 days of gestation. The sows which received the type 2 PRRSV-based vaccine followed by type 2 PRRSV challenge had significantly higher neutralizing antibody titers against type 2 PRRSV than they did against type 1 PRRSV. These same sows had higher frequencies of IFN-γ-secreting cells when stimulated with type 2 PRRSV compared to those stimulated with type 1 PRRSV. Subsequent virological evaluation demonstrated that the type 2 PRRSV-based vaccine reduced the type 2 PRRSV load but not the type 1 PRRSV load present in the blood of the sows. Additionally, vaccination of pregnant sows with the type 2 PRRSV-based vaccine effectively reduced the level of type 2 PRRSV nucleic acids observed in fetal tissues from type 2 PRRSV-challenged sows but did not reduce the level of type 1 PRRSV nucleic acid observed in fetal tissues from type 1 PRRSV-challenged sows. This study demonstrates that the vaccination of pregnant sows with the type 2 PRRSV-based vaccine protects against type 2 PRRSV challenge but does not protect against type 1 PRRSV challenge.</P>

Mechanism of Thapsigargin-induced Apoptosis in MC3T3E1 Osteoblast

Won, Kang-Hee,Kang, Jang-Sook,Chae, Han-Jung,Han, Jo-Il,Kim, Hyung-Ryong 원광대학교 생체재료·매식연구소 1999 원광생체재료·매식 Vol.8 No.1

본 연구는 고농도 칼슘자극에 의한 조골세포주 MC3TE1 세포의 죽음의 단계를 알아보기 위하여 세포내 소기관인 endoplasmic reticulum 의 Ca^++ -ATPase pump를 비가역적으로 억제시키는 물질인 thapsigargin에 의한 조골세포고사 기전을 규명하였다. Thapsigargin은 MC3TE1 세포의 c-Jun N-terminal kinase1 (JNK1)의 활성을 증가시켜 actvating protein-1 (AP-1)의 전사활동을 증가시켰다. Thapsigargin에 의한 MC3TE1의 세포고사 조절기전에 caspase-1과 caspase-3의 활성을 형광기질인 acetyl-YVAD-AMC와 acetyl-DEVD-AMC를 이용하여 관찰한 결과 caspase-3의 활성을 증가시켰으며 또한 nuclear factor-κB (NKκB)의 전사활동을 증가시켰다. 조골세포에서 thapsigargin 에 의한 세포고사 조절기전에 JNK1, caspase-3, protease, AP-1 및 NF-κB의 활성이 관여함을 시사해주고 있다.

Inter- and Intra-observer Variability of a Cervical OPLL Classifi cation Using Reconstructed CT Images

Han Chang,Chae-Gwan Kong,Ho-Yeon Won,Ju-Hwan Kim,,Jong-Beom Park 대한정형외과학회 2010 Clinics in Orthopedic Surgery Vol.2 No.1

Background: The lateral radiograph-based system described by Tsuyama is used widely to classify ossifi cation of the posteriorlongitudinal ligament (OPLL) of the cervical spine. However, OPLL is a complex 3-dimensional (3-D) lesion, not a simple and uniplanarone, which is often diffi cult to identify on a lateral radiograph. Furthermore, its reliability among spine surgeons has notbeen investigated. Given the popularity of a reconstructed computed tomography (CT), this study examined the inter- and intraobserverreliability of lateral radiograph-based OPLL classifi cation using that modality. Methods: Five spine surgeons independently reviewed the lateral radiograph, axial CT, 2-D (sagittal) and 3-D reconstructed CTimages of 108 OPLL patients on 2 separate occasions. Based on these images, the reviewers classifi ed each OPLL case accordingto the Tsuyama’s system. The kappa values were used to assess the statistical reliability. Results: The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination withthe axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa valuesshowed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated afair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribedtype on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcomesomewhat using 2-D and 3-D reconstructed CT images. Conclusions: The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combinationwith the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa valuesshowed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated afair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribedtype on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcomesomewhat using 2-D and 3-D reconstructed CT images.