Effect of Mn and C on Age Hardening of Fe–Mn–Al–C Lightweight Steels

Sung‑Won Park,Jun Young Park,Kyong Mox Cho,Jae Hoon Jang,Seong‑Jun Park,Joonoh Moon,Tae‑Ho Lee,Jong‑Ho Shin 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.3

The effects of Mn and C content on the age hardening of Fe–Mn–Al–C lightweight steels, which have austenitic or duplex(austenite and ferrite) microstructures, were investigated. An increase in Mn content induced a delay of the age hardeningthat is caused by the formation of intra-granular κ-carbides. In order to interpret the effect of Mn content, first-principlescalculations were conducted using the supercells of Fe24Al8C8,Fe24Al8C7,Fe24(Al7Mn)C8, and Fe24(Al7Mn)C7. The calculationsshowed that an increase in Mn content could be the source of the delay of the intra-granular κ-carbide formation bysuppressing C atom’ occupation of the vacancy at the body-centered site of L12. An increase in C content accelerated theformation of intra-granular κ-carbides, which induced the intense age hardening, and coarse inter-granular κ-carbides, whichresulted in significant decrease in impact absorbed energy due to inter-granular fracture.

Relation of Subclinical Hypothyroidism is Associated With Cardiovascular Events and All-Cause Mortality in Adults With High Cardiovascular Risk

Moon, Shinje,Kong, Sung Hye,Choi, Hoon Sung,Hwangbo, Yul,Lee, Moon-Kyu,Moon, Jae Hoon,Jang, Hak Chul,Cho, Nam Han,Park, Young Joo Elsevier 2018 The American Journal of Cardiology Vol.122 No.4

<P>The aim of this study was to determine the association between subclinical hypothyroidism and cardiovascular (CVD) events, and mortality using the atherosclerotic CVD risk score. We carried out an observational study in a prospective cohort that was followed up for 12 years. The study included 3,021 participants aged ≥ 40 years at baseline from the Ansung cohort, part of the Korean Genome and Epidemiology Study. Cox regression models were constructed to evaluate the hazards ratio (HR) and 95% confidence interval (CI) for all-cause mortality and CVD events in groups classified according to thyroid status. Subgroup analysis was performed with a cut-off age of 65 years or 7.5% of the 10-year atherosclerotic CVD risk score. The subclinical hypothyroidism group in the highest quartile of thyroid-stimulating hormone (>6.57 mIU/L) had a significantly increased risk of all-cause mortality (HR 2.12, 95% CI 1.27 to 3.56) and CVD events (HR 1.92, 95% CI 1.21 to 3.04) compared with euthyroid participants. Subgroup analysis by CVD risk revealed that participants with high CVD risk only had a high risk of all-cause mortality (HR 2.18, 95% CI 1.22 to 3.87) and CVD events (HR 2.42, 95% CI 1.35 to 4.33). Further analysis showed that participants aged <65 years with high CVD risk had the highest risk of all-cause mortality (HR 3.50, 95% CI 1.50 to 8.16) and CVD events (HR 3.37, 95% CI 1.46 to 9.57). Our results demonstrated that high thyroid-stimulating hormone levels were associated with a greater risk of mortality and new CVD risks, particularly among subjects with high CVD risk.</P>

Therapeutic Potential of Ethanolic Extract of Ecklonia cava on Inhibition of Inflammation

Moon-Moo Kim,Sang-Hoon Lee,Dai-Nghiep Ngo,Won-Kyo Jung,Se-Kwon Kim 한국해양바이오학회 2007 한국해양바이오학회지 Vol.2 No.2

The sodium ion-assisted memory behaviour of a silicon nanowire partial composite field-effect transistor

Moon, Kyeong-Ju,Lee, Tae Il,Lee, Sang-Hoon,Myoung, Jae-Min The Royal Society of Chemistry 2014 Chemical communications Vol.50 No.31

<P>A partial composite consisting of rough silicon nanowires and a polymer dielectric layer with sufficient Na<SUP>+</SUP> ions was used to create a field-effect transistor based memory device. Addition of Na<SUP>+</SUP> ions helped compensate for water molecule trapped charges leading to narrow hysteresis characteristics and stable memory retention stability of the resulting device.</P> <P>Graphic Abstract</P><P>A partial composite consisting of rough silicon nanowires and a polymer dielectric layer with sufficient Na<SUP>+</SUP> ions was used to create a field-effect transistor based memory device. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4cc00749b'> </P>

Successful treatment in a patient with onychogryphosis associated with onychomycosis

( Sang Hyeon Won ),( Woo Il Kim ),( Min Young Yang ),( Won Ku Lee ),( Gun Wook Kim ),( Hoon Soo Kim ),( Hyun Chang Ko ),( Byung Soo Kim ),( Moon Bum Kim ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.1

Onychogryphosis is a disorder of nail plate growth that is clinically characterized by an opaque, yellow-brown thickening of the nail plate associated with gross hyperkeratosis, elongation, and increased curvature. There can be various causes of acquired onychogryphosis, and onychomycosis may be the one of them. So it should be noted that onychogryphosis and onychomycosis can coexist. We present the case of a 55-year-old man with a 6-year history of severe thickening, abnormal growth, and yellow discoloration of both great toenails, clinically consistent with onychogryphosis. Potassium hydroxide (KOH) examination was positive. It was necessary to treat both onychogryphosis and onychomycosis respectively. There are a wide variety of therapies according to the cause and patient comorbidities. As for onychogryphosis, nail grinding was done as a palliative therapy. And for onychomycosis, efinaconazole 10% topical solution was administered. After 9 months of these combination therapy, significant cosmetic improvements were achieved. To our knowledge, successful treatment for onychogryphosis associated with onychomycosis has rarely been reported in Korean dermatologic literature. Therefore, we suggest that nail grinding and efinaconazole 10% topical medication should be regarded as one of good treatment modalities in a patient with onychogryphosis associated with onychomycosis.

HOXC6 Is Deregulated in Human Head and Neck Squamous Cell Carcinoma and Modulates Bcl-2 Expression

Moon, Sung-Min,Kim, Soo-A,Yoon, Jung-Hoon,Ahn, Sang-Gun American Society for Biochemistry and Molecular Bi 2012 The Journal of biological chemistry Vol.287 No.42

<P>Homeobox C6 (<I>HOXC6</I>) genes belong to the homeoprotein family of transcription factors, which play an important role in morphogenesis and cellular differentiation during embryonic development. The aim of this study was to explore the role of HOXC6 in the regulation of Bcl-2 in human head and neck squamous cell carcinoma (HNSCC). The HOXC6 and Bcl-2 gene were identified as being overexpressed in HNSCC tissue and cell lines. Transfection assays demonstrated that HOXC6 increased the levels of Bcl-2 mRNA and protein. A luciferase reporter assay suggested that HOXC6 induced activity of the Bcl-2 promoter. A series of Bcl-2 promoter deletion mutants were examined and the minimal HOXC6-responsive region was identified to be in the TAAT motif (-420 bp) of the Bcl-2 promoter. Interestingly, the inhibition of HOXC6 using siRNA led to the repression of Bcl-2 expression and induced caspase-3-dependent apoptosis; overexpression of HOXC6 in HNSCC cells increased the resistance to paclitaxel-induced apoptosis. Together, our findings suggest that HOXC6 is an important mechanism of the anti-apoptotic pathway via regulation of Bcl-2 expression.</P>

Fabrication and Characterization of Piezoelectric Composite Nanofibers Based on Poly(vinylidene fluoride-cohexafluoropropylene) and Barium Titanate Nanoparticle

Sang-Hoon Lee,Young Chul Choi,Minsu Kim,Kyung Moon Ryu,정영규 한국섬유공학회 2020 Fibers and polymers Vol.21 No.3

Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based composite nanofibers containing differentbarium titanate (BaTiO3) nanoparticle contents of 10-60 wt% were fabricated by an efficient electrospinning. Thepiezoelectric performance of PVDF-HFP/BaTiO3 composite nanofibers under a periodic compressional pressure of ~20 kPawas investigated by considering the BaTiO3 content and the electric poling. The X-ray diffraction patterns revealed thepresence of piezoelectric tetragonal BaTiO3 nanoparticles in the composite nanofibers with PVDF β-form crystals. The SEMimages demonstrated that the BaTiO3 nanoparticles were dispersed uniformly in the composite nanofibers at relatively lowloadings of 10-20 wt%, but they formed aggregates at high loadings of 30-60 wt%. The piezoelectric performance of thecomposite nanofibers increased with the BaTiO3 content up to 20 wt% and decreased at higher BaTiO3 contents of 30-60 wt%, which results from the trade-off effect between the piezoelectric performance and the dispersibility of BaTiO3nanoparticles in the composite nanofibers. Accordingly, the composite nanofibers with 20 wt% BaTiO3 exhibited maximumpiezoelectric outputs such as voltage of ~9.63 V, current ~0.52 μA, and electric power of ~7892.2 nW. After the electricpoling, the piezoelectric performance was further enhanced to ~11.69 V, ~20.56 μA, and ~1115.2 nW, which was highenough to light up a small LED bulb after rectification.

Surface properties and early murine pre-osteoblastic cell responses of anodized TiO₂ surfaces

( Sang-hoon Kim ),( Hwa-sun Lee ),( Eui-ri Na ),( Jong-wook Moon ),( Young-joon Kim ) 조선대학교 구강생물학연구소 2018 Oral Biology Research (Oral Biol Res) Vol.42 No.1

The noted anodic oxidation of titanium surfaces by the utilization of an electrochemical method is one of the procedures that can be used for the enhancement of osseointegration. This study evaluated the surface characteristics and the cell response of titanium samples that were modified by different treatment conditions. The samples were subsequently divided into 4 groups. In this study, Group I was noted as an anodized TiO₂ film using a constant voltage, 270 V for 30 sec. Further, Group II was noted as using an anodized TiO₂ film using a constant voltage, 270 V for 60 sec. Also, Group III was an anodized TiO₂ film using a constant voltage, 270 V for 90 sec. The control was a non-treated machined titanium surface. The results were as follows: the XRD analysis showed that the crystallinity of anodic oxide film was composed of anatase and rutile. The study continued with the procedure of increasing the time for anodization, whereby it was noted that the intensity of the TiO₂ peaks for anatase phase decreased, while the TiO₂ peak for the rutile phase was seen to have increased. In the MTT assay, it was noted that there was no significant difference in the response of fetal rat calvarial cells to the anodized titanium surfaces with the different treatment conditions. Similarly, the Group II and III showed higher ALP activity levels compared with the control and Group I (p<0.01). In the RT-PCR analysis, it is noted that the bone sialoprotein mRNA expression in Group II and III increased approximately 1.7-fold and 1.5-fold respectively, compared with the control, which was cp-Ti. The osteocalcin mRNA expression in Group II and III also increased approximately 1.6-fold and 1.7-fold respectively, compared with the control. Fundamentally, these results suggest that the anodized TiO₂ surfaces treated at 60 and 90 sec, should promote cellular activity of the noted and reviewed osteoblasts, as compared with the machined Ti surface.

Effect of Preoperative Fatty Degeneration of the Deltoid and the Teres Minor Muscles on the Clinical Outcome after Reverse Total Shoulder Arthroplasty

Sung-Hoon Moon,Woo-Dong Nam,Chang-Hyun Rheu,Jae-Woo Lee 대한견주관절의학회 2015 대한견주관절학회지 Vol.18 No.3

Background: To evaluate the effect of preoperative fatty degeneration of deltoid and teres minor muscles on the clinical outcome in patient with reverse total shoulder arthroplasty (RTSA). Methods: Nineteen patients with RTSA were enrolled. The mean follow-up period was 16.1 months. The fatty degeneration of three distinct parts in each deltoid and the teres minor muscle was measured using a preoperative magnetic resonance imaging. Postoperatively, the muscle strengths for forward elevation (FE), abduction (Abd), and external rotation (ER) were measured using a myometer at the last follow-up. The parameters for clinical outcome were Constant Score (CS) and Korean Shoulder Score (KSS). Results: The number of cases was 10 in group 1 and 9 in group 2. The strength of FE and Abd were significantly higher in group 1 (p<0.001 and p<0.001, respectively), and the strength of ER was not different significantly between two groups (p=0.065). For the clinical outcome, both CS and KSS were higher in group 1 (p=0.002 and p=0.002, respectively). The number of patients in group A was 11, and group B was 8. Although there was not a significant difference in terms of FE and Abd between group A and B (p=0.091, p=0.238), ER was significantly higher in group A (p=0.012). We did not find a significant difference in the clinical scores (CS, p=0.177 and KSS, p=0.238). Conclusions: These findings suggest the importance of a preoperative evaluation of the fatty degeneration of deltoid and teres minor muscles for predicting postoperative strength and clinical outcome.

Two new cases of leprosy in PNUH

( Sang Hyeon Won ),( Woo Il Kim ),( Min Young Yang ),( Won Ku Lee ),( Gun Wook Kim ),( Hoon Soo Kim ),( Hyun Chang Ko ),( Byung Soo Kim ),( Moon Bum Kim ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.1

Leprosy is a chronic infectious disease with prominent involvement of the skin and nerves that is caused by the bacillus Mycobacterium leprae. It can manifest as a wide variety of immunological and clinical features. Although leprosy is now considered a curable disease with a good prognosis, it can still be incapacitating and stigmatizing. That is why early diagnosis and prompt therapy are important to control the disease. But it is rare recently, young dermatologists are often unfamiliar with it. Here, we report two cases of leprosy with different clinical manifestations. Firstly, a 74-year-old woman presented with anesthetic erythematous hairless patches on glabella and both eyebrows for 1 year. Secondly, a 85-year-old man presented with generalized erythematous nodules, and plaques on whole body for 3 months. In both cases, a biopsy was performed and granulomatous dermal infiltration of foamy histiocytes was found. Ziehl-Neelsen stain was positive for acid-fast bacilli (AFB). Serologic assay was positive for anti-PGL antibodies. Mycobacterium leprae infection was also verified by PCR. A diagnosis of leprosy was established based on clinicopathologic features in both cases. Though the chance to meet leprosy patients seems to be quite low nowadays, leprosy didn’t extinguish completely in Korea. And so, it is imperative for dermatologists to increase their vigilance in screening, treating, and reporting cases.