Macroscopic Quantum Tunneling in Superconducting Junctions of β-Ag₂Se Topological Insulator Nanowire

Kim, Jihwan,Kim, Bum-Kyu,Kim, Hong-Seok,Hwang, Ahreum,Kim, Bongsoo,Doh, Yong-Joo American Chemical Society 2017 NANO LETTERS Vol.17 No.11

<P>We report on the fabrication and electrical transport properties of superconducting junctions made of beta-Ag2Se topological insulator (Tl) nanowires in contact with Al superconducting electrodes. The temperature dependence of the critical current indicates that the superconducting junction belongs to a short and diffusive junction regime. As a characteristic feature of the narrow junction, the critical current decreases monotonously with increasing magnetic field. The stochastic distribution of the switching current exhibits the macroscopic quantum tunneling behavior, which is robust up to T = 0.8 K. Our observations indicate that the Tl nanowire-based Josephson junctions can be a promising building block for the development of nanohybrid superconducting quantum bits.</P>

노이즈 면역을 향상시킨 플립플롭

김아름(AhReum Kim),김선권(Sunkwon Kim),이현중(Hyunjoong Lee),김수환(Suhwan Kim) 大韓電子工學會 2011 電子工學會論文誌-SD (Semiconductor and devices) Vol.48 No.8

휴대용 전자 기기 수요가 증가하면서 저전력 회로에 대한 관심이 커지고 있다. 이와 더불어 프로세서 데이터 패스의 폭이 넓어지고, 파이프라인의 단계가 많아짐에 따라, 사용되는 플립플롭의 수가 증가하였다. 그로 인해 플립플롭의 전력 소모 및 성능이 전체 시스템에 미치는 영향이 커졌다. 또한, 반도체 공정 스케일이 점점 줄면서, 공급 전압과 문턱 전압이 감소되었고 이로 인해 노이즈가 회로에 미치는 영향이 커지고 있다. 본 논문에서는 노이즈 면역을 향상시키면서도 저전력 시스템에 사용할 수 있는 플립플롭을 제안하고자 한다. 제안한 회로는 1.2V에서 동작하는 65㎚ CMOS 공정으로 구현하였다. As the data path of the processor widens and the depth of the pipeline deepens, the number of required registers increases. Consequently, careful attention must be paid to the design of clocked storage elements like latches and flipflops as they have a significant bearing on the overall performance of a synchronous VLSI circuit. As technology is also scaling down, noise immunity is becoming an important factor. In this paper, we present a new flipflop which has an improved noise immunity when compared to the hybrid latch flipflop and the conditional precharge flipflop. Simulation results in 65㎚ CMOS technology with 1.2V supply voltage are used to demonstrate the effectiveness of the proposed flipflop structure.

Evaluation of Antigen-Specific Immunoglobulin G Responses in Pulmonary Tuberculosis Patients and Contacts

Hur, Yun-Gyoung,Kim, Ahreum,Kang, Young Ae,Kim, An Sik,Kim, Dae Yeon,Kim, Yeun,Kim, Youngmi,Lee, Hyeyoung,Cho, Sang-Nae American Society for Microbiology 2015 Journal of clinical microbiology Vol.53 No.3

<P>This study aimed to evaluate the serodiagnostic potential of immunoglobulin G (IgG) responses to <I>Mycobacterium tuberculosis</I> antigens in pulmonary tuberculosis (TB) patients, recent TB contacts with latent TB infection (LTBI), and healthy subjects. Infections were assessed using tuberculin skin tests, QuantiFERON-TB Gold In-Tube tests, drug susceptibility testing, and molecular genotyping of clinical isolates. Serum IgG responses to selective <I>M. tuberculosis</I> antigens, including the 38-kDa and 16-kDa antigens, lipoarabinomannan (LAM), and recombinant early secreted antigen target 6 kDa (ESAT-6) and culture filtrate protein 10 kDa (CFP-10), were determined. We found that the serum IgG responses to all antigens might differentiate between active TB and LTBI, with LAM having the highest diagnostic value (area under the curve [AUC] of 0.7756, <I>P</I> < 0.001). Recurrent TB cases showed significantly higher IgG responses to 38 kDa, CFP-10 (<I>P</I> < 0.01), and LAM (<I>P</I> < 0.05) than new cases, and male patients had higher levels of antigen-specific IgG than females (<I>P</I> < 0.05). Conversely, drug resistance and patient body mass index did not affect IgG responses (<I>P</I> > 0.05). LAM-specific IgG responses differentiated between acid-fast bacillus (AFB) smear-positive and -negative patients (<I>P</I> < 0.01), whereas antigen-specific IgG responses did not vary with the <I>M. tuberculosis</I> genotype (<I>P</I> > 0.05). Significantly higher IgG responses to 38 kDa and 16 kDa were observed in AFB smear-negative patients than in controls. These results suggest that assessment of serum IgG responses to selective purified <I>M. tuberculosis</I> antigens may help improve the diagnosis of active TB, particularly for sputum smear-negative patients or recurrent cases, and these may also help to differentiate between active TB and LTBI.</P>

Diff-Quik 염색방법에 의한 오계 닭 정자의 염색질 이상과 운동성 추정에 관한 연구

김성우(Sung Woo Kim),최아름(Ahreum Choi),최창용(Changyong Choe),김동교(Dongkyo Kim),성환후(Hwan-Hoo Seong),김재환(Jae-Hwan Kim),김종대(Chongdae Kim) 한국가금학회 2015 韓國家禽學會誌 Vol.42 No.2

Trends of Incidence, Mortality, and Future Projection of Spinal Fractures in Korea Using Nationwide Claims Data

Kim, Tae-Young,Jang, Sunmee,Park, Chan-Mi,Lee, Ahreum,Lee, Young-Kyun,Kim, Ha-Young,Cho, Eun-Hee,Ha, Yong-Chan The Korean Academy of Medical Sciences 2016 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.31 No.5

<P>Spinal fractures have been recognized as a major health concern. Our purposes were to evaluate the trends in the incidence and mortality of spinal fractures between 2008 and 2012 and predict the number of spinal fractures that will occur in Korea up to 2025, using nationwide data from the National Health Insurance Service (NHIS). A nationwide data set was evaluated to identify all new visits to medical institutes for spinal fractures in men and women aged 50 years or older between 2008 and 2012. The incidence, mortality rates and estimates of the number of spinal fractures were calculated using Poisson regression. The number of spinal fractures increased over the time span studied. Men and women experienced 14,808 and 55,164 vertebral fractures in 2008 and 22,739 and 79,903 in 2012, respectively. This reflects an increase in the incidence of spinal fractures for both genders (men, 245.3/100,000 in 2008 and 312.5/100,000 in 2012; women, 780.6/100,000 in 2008 and 953.4/100,000 in 2012). The cumulative mortality rate in the first year after spinal fractures decreased from 8.51% (5,955/69,972) in 2008 to 7.0% (7,187/102,642) in 2012. The overall standardized mortality ratio (SMR) of spinal fractures at 1 year post-fracture was higher in men (7.76, 95% CI: 7.63-7.89) than in women (4.70, 95% CI: 4.63-4.76). The total number of spinal fractures is expected to reach 157,706 in 2025. The incidence of spinal fractures increased in Korea in the last 5 years, and the socioeconomic burden of spinal fractures will continue to increase in the near future.</P>

FC 1-6 : The clinical impact of rituximab reimbursement by national health insurance on the treatment of pemphigus in South Korea

( Ahreum Song ),( Jieun Jang ),( Soo-chan Kim ),( Jaeyong Shin ),( Jong Hoon Kim ) 대한피부과학회 2021 대한피부과학회 학술발표대회집 Vol.73 No.-

Background: The use of rituximab has been shown to be effective in the treatment of pemphigus, thereby inducing remission efficiently and permitting rapid tapering of corticosteroid doses. The high cost had been a burden in South Korea until Feb. 2018, when the National Health Insurance has started to reimburse the rituximab therapy for patients with severe pemphigus. Objectives: To assess the clinical impact of rituximab reimbursement policy on treatment of pemphigus in South Korea. Methods: A single-center, observational study was conducted including 214 patients with pemphigus treated with their first rituximab from Jan. 2014 to Dec. 2020. T-tests and time series graph comparisons were carried out to evaluate the time of starting rituximab, time taken to achieve the partial remission under minimum therapy (PRMT), and the amount of systemic corticosteroid intake. Results: The time to initiate rituximab was significantly shorter after the rituximab reimbursement policy (p = 0.008). Total systemic corticosteroid intake for the first year of treatment (p = 0.001), and for the 6 months after the rituximab treatment (p = 0.044) were significantly decreased after the rituximab reimbursement policy, but the time to reach the PRMT was not (p = 0.184). Conclusion: The reimbursement policy of rituximab in South Korea had a significant effect on the shortening of time to start rituximab therapy, thereby decrease the amount of total steroid intake after rituximab for the pemphigus patients.

Protective Vaccine Efficacy of the Complete Form of PPE39 Protein from <i>Mycobacterium tuberculosis</i> Beijing/K Strain in Mice

Kim, Ahreum,Hur, Yun-Gyoung,Gu, Sunwha,Cho, Sang-Nae AMERICAN SOCIETY FOR MICROBIOLOGY 2017 CLINICAL AND VACCINE IMMUNOLOGY Vol.24 No.11

<P>The aim of this study was to evaluate the protective efficacy of MTBK_24820, a complete form of PPE39 protein derived from a predominant Beijing/K strain of Mycobacterium tuberculosis in South Korea. Mice were immunized with MTKB_24820, M. bovis Bacilli Calmette-Guerin (BCG), or adjuvant prior to a high-dosed Beijing/K strain aerosol infection. After 4 and 9 weeks, bacterial loads were determined and histopathologic and immunologic features in the lungs and spleens of the M. tuberculosis-infected mice were analyzed. Putative immunogenic T-cell epitopes were examined using synthetic overlapping peptides. Successful immunization of MTBK_24820 in mice was confirmed by increased IgG responses (P < 0.05) and recalled gamma interferon (IFN-gamma), interleukin-2 (IL-2), IL-6, and IL-17 responses (P < 0.05 or P < 0.01) to MTBK_24820. After challenge with the Beijing/K strain, an approximately 0.5 to 1.0 log(10) reduction in CFU in lungs and fewer lung inflammation lesions were observed in MTBK_24820-immunized mice compared to those for control mice. Moreover, MTBK_24820 immunization elicited significantly higher numbers of CD4(+) T cells producing protective cytokines, such as IFN-gamma and IL-17, in lungs and spleens (P < 0.01) and CD4(+) multifunctional T cells producing IFN-gamma, tumor necrosis factor alpha (TNF-alpha), and/or IL-17 (P < 0.01) than in control mice, suggesting protection comparable to that of BCG against the hypervirulent Beijing/K strain. The dominant immunogenic T-cell epitopes that induced IFN-gamma production were at the N terminus (amino acids 85 to 102 and 217 to 234). Its vaccine potential, along with protective immune responses in vivo, may be informative for vaccine development, particularly in regions where the M. tuberculosis Beijing/K-strain is frequently isolated from TB patients.</P>

[P9-15] The Neuroprotective Effect of Wild Ginseng Pharmacopuncture for 1-methyl-4-phenyl-1,2,3,6-tetrahy-dropyridine Induced Parkinson's Disease Mice Model

AhReum Doo,Seung-Tae Kim,Younbyoung Chae,Hyekyung Kim,Hi-Joon Park 한국식품영양과학회 2007 한국식품영양과학회 학술대회발표집 Vol.2007 No.10

An efficient first arrival picking procedure for marine streamer data

Ahreum Kim,Donghyun Ryu,하완수,신창수 한국자원공학회 2015 Geosystem engineering Vol.18 No.5

Picking first breaks is a tedious and time-consuming process. We suggest a procedure for an efficient manual first arrival picking of marine towed-streamer data. The procedure contains three methods: we reduce the total number of manual picks by skipping shots and interpolating picks of each shot gather, reusing previous picks, and sorting three-dimensional (3D) shot gathers using offset. Two-dimensional and 3D simulations demonstrate that we can accelerate the picking process 11–117 times compared to that of a complete picking method. Although the efficiency varies depending on the data, the suggested procedure can save considerable manpower while maintaining the accuracy of manual picking.

Metabolic changes in urine and serum during progression of diabetic kidney disease in a mouse model

Kim, Nan Hee,Hyeon, Jin Seong,Kim, Nam Hoon,Cho, Ahreum,Lee, Gayoung,Jang, Seo Young,Kim, Mi-Kyung,Lee, Eun Young,Chung, Choon Hee,Ha, Hunjoo,Hwang, Geum Sook Elsevier 2018 Archives of biochemistry and biophysics Vol.646 No.-

<P><B>Abstract</B></P> <P>Diabetic kidney disease (DKD) involves various pathogenic processes during progression to end stage renal disease, and activated metabolic pathways might be changing based on major pathophysiologic mechanisms as DKD progresses. In this study, nuclear magnetic resonance spectroscopy (NMR)-based metabolic profiling was performed in <I>db/db</I> mice to suggest potential biomarkers for early detection and its progression. We compared concentrations of serum and urinary metabolites between <I>db/m</I> and <I>db/db</I> mice at 8 or 20 weeks of age and investigated whether changes between 8 and 20 weeks in each group were significant. The metabolic profiles demonstrated significantly increased urine levels of glucose and tricarboxylic acid cycle intermediates at both 8 and 20 weeks of age in <I>db/db</I> mice. These intermediates also exhibited strong positive associations with urinary albumin excretion, suggesting that they may be potential biomarkers for early diagnosis. On the contrary, branched chain amino acid and homocysteine-methionine metabolism were activated early in the disease, whereas ketone and fatty acid metabolism were significantly changed in the late phase of the disease. We demonstrated phase-specific alterations in metabolites during progression of DKD. This study provides insights into perturbed mechanisms during evolution of the disease and identifies potential novel biomarkers for DKD.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Metabolic profiling during progression of diabetic kidney disease (DKD) were performed. </LI> <LI> Urinary and serum metabolites in the early and late stages of DKD in <I>db/db</I> mice were identified. </LI> <LI> BCAA and homocysteine-methionine metabolism were activated early in the disease. </LI> <LI> Ketone and fatty acid metabolism were changed in the late phase of the disease. </LI> </UL> </P>