Engineering an aligned endothelial monolayer on a topologically modified nanofibrous platform with a micropatterned structure produced by femtosecond laser ablation

Shin, Young Min,Shin, Hyeok Jun,Heo, Yunhoe,Jun, Indong,Chung, Yong-Woo,Kim, Kyeongsoo,Lim, Youn Mook,Jeon, Hojeong,Shin, Heungsoo The Royal Society of Chemistry 2017 Journal of Materials Chemistry B Vol.5 No.2

<P>A monolayer of endothelial cells (ECs) aligned along the direction of blood flow plays crucial roles in the regulation of anti-thrombogenic and pro-inflammatory reactions in the blood vessel wall. Thus, many researchers have attempted to mimic the aligned structure of ECs in vascular grafts or tissue-engineered blood vessels. In the present study, we fabricated micro-groove patterned nanofibers using a femtosecond laser ablation technique to recapitulate the densely organized anisotropic architecture of the endothelial layer. Femtosecond laser ablation enabled us to generate high-resolution groove patterns (10 μm width) with 20 or 80 μm gaps on randomly oriented electrospun nanofibers. The patterned nanofibers exhibited anisotropic (transverse: 101.1 ± 4.0° and longitudinal: 123.5 ± 9.4°) water contact angles; however, the mechanical properties were consistent in both directions. The micropatterned nanofibers modulated the aligned structure or aspect ratio (20 μm: 0.23 ± 0.11 and 80 μm: 0.42 ± 0.18) of ECs along the pattern direction. In particular, the engineered aligned endothelial layer was effective in eliciting an anti-inflammatory response (approximately 50% greater than that of random or aligned nanofibers), thereby effectively preventing monocyte adhesion following activation by TNF-α treatment. Therefore, micropatterning by laser ablation can be utilized to generate high-resolution microgrooves on various substrates, thereby providing fundamental platforms for vascular tissue engineering.</P>

P181 Secondary cutaneous DLBCL has a higher IPI score and worse prognosis than DLBCL, leg type

( Hojeong Shin ),( Woojin Lee ),( Kwanghee Won ),( Chonghyun Won ),( Sungeun Chang ),( Jeeho Choi ),( Keechan Moon ),( Chansik Park ),( Jooryung Huh ),( Cheolwon Suh ),( Miwoo Lee ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.2

<div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div><div style="display:none">fiogf49gjkf0d</div> Background: Differences in skin lesions and survival data for cutaneous diffuse large B-cell lymphoma (DLBCL) depending on primary tumor site are currently unknown. Objectives: we aimed to analyze the clinical features of skin lesions and survival outcomes of cutaneous DLBCL according to the primary tumor site. Methods: Forty-seven patients with cutaneous DLBCL were classified as primary cutaneous DLBCL or cutaneous DLBCL secondary to primary disease. Clinical features, survival outcomes, and prognostic factors were analyzed using patient medical records. Survival outcomes were analyzed using the Kaplan.Meier method and compared using the log-rank test. Results: Although skin lesion characteristics did not significantly differ between groups, secondary cutaneous DLBCL more commonly presented disseminated skin lesions that involved multiple anatomical sites. Primary cutaneous DLBCL demonstrated a less aggressive clinical course and better survival outcomes than secondary cutaneous DLBCL. Disseminated skin lesions and a location on the leg significantly affected the prognosis of primary cutaneous DLBCL. The multiplicity of skin lesions and time point of cutaneous involvement were associated with prognosis in secondary cutaneous DLBCL. Conclusion: Although the clinical features of skin lesions were similar regardless of subgroup, survival outcomes and prognostic factors differed depending on the primary tumor site of cutaneous DLBCL.

Treatment of acne scars with autologous fibroblast injection

( Hojeong Shin ),( Yejin Lee ),( Woojin Lee ),( Sungeun Chang ),( Miwoo Lee ),( Jeeho Choi ),( Chonghyun Won ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.2

Background: Acne scars cause cosmetically and psychologically devastating effect. Autologous fibroblast injections increase dermal collagen formation result in dermal remodeling without serious adverse events. Objectives: We evaluated efficacy and safety of autologous fibroblast injections for treatment of acne scars. Methods: Five patients with acne scar included and fibroblast were cultured from postauricualr fold skin for 8 weeks. Cultured autologous fibroblasts(20million/mL) or placebo were injected intradermaly on both cheek for three times at 2 week intervals. Primary end point was a 2-point shift in at least one treated area using a standardized 7-point photoguide. Secondary end point was improvement of ECCA grading scale, physician improvement scale, subject acne scar assessment. Results: Three patients received autologous fibroblast injection and two patients received placebo injection. All three patients responded to the treatment with a 2-point shift in at least one treated area. ECOG grading score was improved by 48% in treatment group and 5% in control group. Average of physician improvement scale was 2.7 for treatment group and 0 for control group. In treatment group, 2 patients were satisfied, and 1 patients was very satisfied. Autologous fibroblast injections were well tolerated, without permanent adverse effect. Conclusion: Our results suggest that autologous fibroblast injections could be another option for treatment of acne scars.

Clinicopathological significance of tumor infiltrating lymphocytes and programmed death-1 expression in cutaneous melanoma: a comparative study on clinical subtypes

( Hojeong Shin ),( Woojin Lee ),( Yejin Lee ),( Chonghyun Won ),( Sungeun Chang ),( Jeeho Choi ),( Miwoo Lee ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.2

Background: Interactions between immune cells and tumor cells play an important role in tumor progression. Objectives: We evaluated patterns of tumor infiltrating lymphocytes (TILs) and programmed death-1 (PD-1) expression in acral and non-acral cutaneous melanoma, and determined their effects on clinicopathological characteristics and biologic responses. Methods: We identified 122 cases of cutaneous melanoma, of which 39 were cases of non-nail unit acral melanoma, 35 were cases of nail unit melanoma and 48 were cases of non-acral melanoma. Clinicopathological features and survival outcomes were analyzed according to the scores for TILs and PD-1 expression in intra- and peritumoral compartments. Results: The frequency of intratumoral TILs and PD-1 expression were lower in nail unit melanoma than in the other two subtypes. The density of peritumoral PD-1 was significantly higher in non-nail unit acral melanoma. In nail unit melanoma and non-acral melanoma, a low density of intratumoral TILs and PD-1 was associated with a deeper Breslow thickness and the presence of a vertical growth phase. In non-nail unit acral melanoma, a high density of peritumoral TILs and PD-1 was associated with a shallower Breslow thickness and less frequent extracutaneous dissemination. Conclusion: This study suggests that the effects of PD-1+TILs on biological activity differ according to the clinical subtypes of cutaneous melanoma.

감마선 폭발 관측용 2U 초소형위성의 Worst hot case 열 해석을 통한 태양전지판 배치 설계

신호정(Hojeong Shin),송명준(Myeongjun Song),최성임(Seongim Choi) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.11

부유식 진자형 파력발전장치용 에너지 변환시스템의 수치모델링

천호정(Hojeong Cheon),신승호(Seungho Shin) 한국해양환경·에너지학회 2016 한국해양환경공학회 학술대회논문집 Vol.2016 No.5

Association between body mass index and cortical thickness: among elderly cognitively normal men and women

Kim, Hojeong,Kim, Changsoo,Seo, Sang Won,Na, Duk L.,Kim, Hee Jin,Kang, Mira,Shin, Hee-Young,Cho, Seong Kyung,Park, Sang eon,Lee, Jeongmin,Hwang, Jung Won,Jeon, Seun,Lee, Jong-Min,Kim, Geon Ha,Cho, Han Cambridge University Press 2015 INTERNATIONAL PSYCHOGERIATRICS - Vol.27 No.1

<B>ABSTRACT</B><B>Background:</B><P>There is increasing evidence of a relationship between underweight or obesity and dementia risk. Several studies have investigated the relationship between body weight and brain atrophy, a pathological change preceding dementia, but their results are inconsistent. Therefore, we aimed to evaluate the relationship between body mass index (BMI) and cortical atrophy among cognitively normal participants.</P><B>Methods:</B><P>We recruited cognitively normal participants (<I>n</I> = 1,111) who underwent medical checkups and detailed neurologic screening, including magnetic resonance imaging (MRI) in the health screening visits between September 2008 and December 2011. The main outcome was cortical thickness measured using MRI. The number of subjects with five BMI groups in men/women was 9/9, 148/258, 185/128, 149/111, and 64/50 in underweight, normal, overweight, mild obesity, and moderate to severe obesity, respectively. Linear and non-linear relationships between BMI and cortical thickness were examined using multiple linear regression analysis and generalized additive models after adjustment for potential confounders.</P><B>Results:</B><P>Among men, underweight participants showed significant cortical thinning in the frontal and temporal regions compared to normal weight participants, while overweight and mildly obese participants had greater cortical thicknesses in the frontal region and the frontal, temporal, and occipital regions, respectively. However, cortical thickness in each brain region was not significantly different in normal weight and moderate to severe obesity groups. Among women, the association between BMI and cortical thickness was not statistically significant.</P><B>Conclusions:</B><P>Our findings suggested that underweight might be an important risk factor for pathological changes in the brain, while overweight or mild obesity may be inversely associated with cortical atrophy in cognitively normal elderly males.</P>

P212 The treatment of pigmentary skin lesions using 1,927nm thulium laser “Lavieen^R”

( Sungeun Chang ),( Hojeong Shin ),( Woojin Lee ),( Chonghyun Won ),( Jeeho Choi ),( Miwoo Lee ),( Sunyoung Choi ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.2

Background: The treatment of pigmentary skin lesions has always been a challenge for dermatologists. Fractional 1927nm Thullium laser (Lavieen^R) has shown effectiveness in treating melasma, postinflammatory hyperpigmentation and seborrheic keratosis. Objectives: We aimed to treat refractory cases of diverse pigmentatry lesions using the fractional 1927nm Thullium laser. 8 patients with melasma, PIH, seborrheic keratosis, pigmented contact dermatitis were treated. Methods: A total of 8 patients with refractory pigmentary lesions were included. A single treatment session using the fractional 1927nm Thullium laser was carried out in 5 patients and 2 sessions with a 4-week interval were done in 3 of the patients. In a subset of patients, post-procedural topical application of polydeoxyribonucleotide (Placentex^R) was performed. Clinical efficacy was assessed using pre- and post-treatment clinical photographs. Results: All patients exhibited mild to moderate therapeutic responses with high levels of satisfaction. No serious adverse event was reported. Interestingly, the post-procedural application of whitening agents significantly improved the clinical outcome, probably owing to the facilitation of active agents`` delivery to the dermis. Conclusion: Overall, fractional 1927nm Thullium laser (Lavieen^R) seems to be an effective therapeutic option to treat a variety of pigmentary lesions with minimal downtime and could also be a promising tool to boost dermal drug delivery.

Complete photodissociation dynamics of CF₂I₂ in solution

Park, Seongchul,Shin, Juhyang,Yoon, Hojeong,Pak, Youngshang,Lim, Manho The Royal Society of Chemistry 2019 Physical chemistry chemical physics Vol.21 No.13

<P>Photodissociation dynamics of CF2I2 in cyclohexane were evaluated by probing the C-F stretching mode over a wide time range after ultraviolet excitation using femtosecond infrared spectroscopy. After the ultrafast (<0.2 ps) state-selective photodissociation of CF2I2 as in the gas phase (267 nm excitation led to exclusive three-body dissociation (CF2 + I + I), 350 nm to exclusive two-body dissociation (CF2I + I), and 310 nm to a mixture of three- and two-body dissociations), various secondary reactions were observed. Once produced, some nascent CF2 radicals immediately formed a complex with the departing I atom (I⋯CF2), which produced either CF2I or CF2 radicals. The produced CF2I geminately recombined with the I atom, whereas the CF2 radical reacted bimolecularly to produce C2F4 with a diffusion-limited rate constant of 8.1 × 10<SUP>9</SUP> M<SUP>−1</SUP> s<SUP>−1</SUP>. Some nascent CF2I radicals were produced with sufficient excess energy to further dissociate into CF2 and I, or immediately reacted with the dissociated I atom to form the I2-CF2 isomer that rapidly dissociated into CF2 and I2. Other nascent CF2I radicals geminately recombined with the I atom with various time constants. Thus, the nascent photoproducts, CF2 and CF2I take various reaction paths: complex formation, secondary dissociation, isomer formation, and fast and slow germinate rebindings. The ensuing reaction path of the nascent photoproduct is dictated by its internal energy as well as solvent environment, which leads to different interactions between the photoproduct and solvent. Measurement over a broad time range with a structure-sensitive probe could reveal the fate of all the reaction intermediates, which allows evaluation of the complete reaction dynamics in solution.</P>

Investigation of Structure–Property Relationships in Diketopyrrolopyrrole-Based Polymer Semiconductors via Side-Chain Engineering

Back, Jang Yeol,Yu, Hojeong,Song, Inho,Kang, Il,Ahn, Hyungju,Shin, Tae Joo,Kwon, Soon-Ki,Oh, Joon Hak,Kim, Yun-Hi American Chemical Society 2015 Chemistry of materials Vol.27 No.5

<P>Systematic side-chain engineering has been performed for diketopyrrolopyrrole-selenophene vinylene selenophene (DPP-SVS) polymers to determine the optimal side-chain geometries for the most efficient charge transport, and the structure–property relationship has been thoroughly investigated using a range of analyses. A series of DPP-SVS polymers, ranging from 25-DPP-SVS to 32-DPP-SVS, with branched alkyl groups containing linear spacer groups from C2 to C9 has been synthesized, and the electrical performance of these polymers is significantly dependent on both the length of the spacer group and its odd–even characteristics. Spacer groups with even numbers of carbon atoms exhibit charge-carrier mobilities that are 1 order of magnitude higher than those with odd numbers of carbon atoms. The optimized charge transport has been obtained from 29-DPP-SVS with a C6 spacer, showing the maximum mobility of 13.9 cm<SUP>2</SUP> V<SUP>–1</SUP> s<SUP>–1</SUP> (<I>V</I><SUB>GS</SUB>, <I>V</I><SUB>DS</SUB> = −100 V) and 17.8 cm<SUP>2</SUP> V<SUP>–1</SUP> s<SUP>–1</SUP> (<I>V</I><SUB>GS</SUB>, <I>V</I><SUB>DS</SUB> = −150 V). Longer spacer groups deviate from the odd–even trend. In addition to the exceptionally high charge-carrier mobilities of the DPP-SVS polymers, the results obtained herein provide new insight into the molecular design of high-performance polymer semiconductors.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2015/cmatex.2015.27.issue-5/cm504545e/production/images/medium/cm-2014-04545e_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm504545e'>ACS Electronic Supporting Info</A></P>