Ultra-energy-efficient analog-to-digital converters based on single-electron transistor/CMOS hybrid technology for biomedical applications

Lee, Jieun,Choi, Changmin,Park, Sungwook,Chung, In-Young,Kim, Chang-Joon,Park, Byung-Gook,Kim, Dong Myong,Kim, Dae Hwan Institute of Physics 2009 Semiconductor science and technology Vol.24 No.11

<P>Ultra-energy-efficient analog-to-digital converters (ADCs) based on single-electron transistor (SET)/complementary metal-oxide-semiconductor (CMOS) hybrid technology are proposed as a solution to sense and process biomedical signals. Our results show the energy efficiency of 0.82 pJ/state, which is lower than that in previously reported energy-efficient ADCs. The performance and dissipated power of proposed ADCs are estimated and compared with those of CMOS ADCs by using Lee's SPICE model including non-ideal effects of the experimental data. While the proposed ADC shows an operating power lower by two orders of magnitude than that of the CMOS flash-type ADC, the number of required transistors is about 10% of that in the CMOS flash-type ADC. The peak-to-valley current ratio in Coulomb oscillation of SETs used in the circuit implementation has the range of 1.15–1.5, which is consistent with the experimental result of top-down approached Si-based SETs at <I>T</I> = 77–100 K. From the perspective of the immunity to the gate capacitance <I>C<SUB>cg</SUB></I> mismatch and the background charge <I>Q</I><SUB>0</SUB> noise, it is shown that the criteria of SET/CMOS hybrid ADCs are Δ<I>C<SUB>cg</SUB></I> ⩽ 0.02 × <I>C<SUB>cg</SUB></I> (with <I>C<SUB>cg</SUB></I> = 0.24 aF) and Δ<I>Q</I><SUB>0</SUB> ⩽ 0.23<I>q</I>, respectively.</P>

발달장애학생의 성인기 전환교육에 대한 메타적 중요도-실행도(IPA) 분석 : 2000년 이후 국내 논문을 중심으로

황지은 ( Hwang¸ Jieun ),이미지 ( Lee¸ Miji ),박지현 ( Park¸ Jihyun ) 한국지적장애교육학회 2021 지적장애연구 Vol.23 No.3

본 연구는 교사인식에 따른 국내 발달장애 대상 성인기 전환교육에 대한 중요도-실행도(IPA) 연구를 메타적으로 분석함으로써 지금까지 이루어진 전환교육의 하위영역별 중요성과 실행도를 종합적인 관점에서 검토하고 앞으로의 접근 방향성을 제시하는 데 목적을 두고 있다. 이를 위해 2000년대 이후 출판된 발달장애학생들의 성인기 전환교육에 관한 교사인식을 다룬 연구 중에서 중요도와 실행도를 모두 포함하는 총 14편의 연구를 대상으로 메타적인 분석을 실행하였다. 연구의 결과는 다음과 같다. 첫째, 각 연구에 대한 개별 매트릭스를 도출한 뒤 하나의 전체 매트릭스로 통합하고 사분면에 제시된 중영역의 특성을 바탕으로 분석한 결과, ‘전환교육 계획 및 실행, 진로/직업, 전환 협력, 교사 역량, 학생 역량’이라는 5개의 주제를 도출하였으며, 이를 다시 사분면에 따른 주제별 비율로 제시하였다. 둘째, 전환주제별 세부항목이 사분면에 위치하는 양상을 중복성과 단일성 여부로 나누어 분석한 결과, 2개 이상의 사분면에 중복 위치한 항목이 다수 나타났고 단일 사분면에 위치한 항목들도 주제별로 확인할 수 있었다. 이러한 IPA 매트릭스에 대한 메타적 의미 분석에 따라 발달장애 대상 전환교육의 현 실정을 점검하고 앞으로의 지원 방향성 및 후속 연구에 시사하는 바를 논의하였다. The purpose of this study is to review the degrees of importance and performance of subcategories of transition education from a holistic perspective and to present the direction of future approach by meta-importance-performance analysis (IPA) studies of transition education to adulthood for students with developmental disabilities in Korea regarding teachers’ perceptions. A meta-analyzing method was conducted on the 14 studies published since 2000s, including both importance and performance. The analysis areas are as follows: the entire analysis of the key information presented in the 14 studies, a meta-analysis with the entire IPA matrix applied, and subjects derivation based on subcategories of transition education and its’ quadrant layout aspect analysis. As a result of the study, first, five themes, 'transition education planning and implementation, career/job, transition cooperation, teacher competency, and student competency', were derived from the characteristics of the subcategories presented in the quadrant and then they were presented again as a topic-specific ratio according to the quadrant. Second, the detailed items of each transition topic were analyzed by dividing them into redundancy and unity, and many items were found to be overlapped in two or more quadrants, and items located in a single quadrant could be checked by subjects. Following the meta-meaning analysis of these IPA matrices, the current state of transition education for students with developmental disabilities was examined and implications for future support directions and subsequent studies were discussed.

High expression level of SOX2 is significantly associated with shorter survival in patients with thymic epithelial tumors

Lee, Guk Jin,Lee, Heejung,Woo, In Sook,Kim, Taejung,An, Ho Jung,Choi, Hyun Joo,Lee, Youn Soo,Lee, Kyo Young,Lee, Jieun,Kang, Jin-Hyoung Elsevier 2019 Lung cancer Vol.132 No.-

<P><B>Abstract</B></P> <P><B>Objectives</B></P> <P>Thymic epithelial tumors (TET) are heterogenous tumors which are composed of thymoma (TM) and thymic carcinoma (TC). We attempted to determine differences in gene expression between TM and TC, and to determine the effect of such genes on the prognosis of patients with TET.</P> <P><B>Materials and methods</B></P> <P>Gene expression profiles of SOX2, OCT-4, IGF-1, IGF-1R and IR mRNA transcripts in tumor tissues of TM and TC were determined using real-time PCR (RT-PCR). We constructed tissue microarray with 140 paraffin-embedded tumor tissues and performed immunohistochemistry (IHC) for IGF-1R-related signaling molecules, including SOX2, IGF-1, IGF-1R and pAKT.</P> <P><B>Results</B></P> <P>SOX2 mRNA expression was notably higher (216-fold) in TCs than in TMs. However, there was no significant difference in expression of IGF-1, IGF-1R, OCT-4 or IR between the two tumor types. In IHC results, SOX2 (HR: 7.57, P = 0.001) and IGF-1 (HR: 9.43, P = 0.001) expression levels in TC were significantly higher than those in TM. There was a significant correlation in expression of SOX2 with IGF-1 (P = 0.021) and pAKT (P = 0.026). In univariate analysis, clinical TNM stage, WHO classification, serum LDH, expression of SOX2, IGF-1R, IGF-1 and pAKT, were significantly correlated with overall survival (OS). Multivariate analysis using a forward-selection procedure revealed that clinical N stage (HR: 4.08, P < 0.001), M stage (HR: 3.37, P = 0.001) and SOX2 expression (HR: 4.53, P = 0.010) were significantly associated with OS.</P> <P><B>Conclusions</B></P> <P>SOX2 is expressed significantly higher in TC than in TM. SOX2 expression is also closely related to IGF-1 and pAKT expression. The higher expression of SOX2 is significantly associated with shorter survival in patients with TET.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Thymic epithelial tumors (TET) are divided into two broad categories, thymoma (TM) and thymic carcinoma (TC). </LI> <LI> Molecular biology of TETs are poorly understood. </LI> <LI> We suggest that SOX2 might be potential biomarker to predict biologic aggressiveness and poor prognosis in TETs. </LI> </UL> </P>

Activity concentrations and radiological hazard assessments of ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs in soil samples obtained from the Dongnam Institute of Radiological & Medical Science, Korea

Jieun Lee,HyoJin Kim,Yong Uk Kye,Dong Yeon Lee,Wol Soon Jo,Chang Geun Lee,Jeung Kee Kim,Jeong-Hwa Baek,Yeong-Rok Kang Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.7

The radioactivity concentration of environmental radionuclides was analyzed for soil and sand at eight locations within a radius of 255 m centered on the Dongnam Institute of Radiological & Medical Science (DIRAMS), Korea. The average activity concentrations of ⁴⁰K, ¹³⁷Cs, ²²⁶Ra, and ²³²Th were 661.1 Bq/kg-dry, 0.9 Bq/kg-dry, 21.9 Bq/kg-dry, and 11.1 Bq/kg-dry, respectively. The activity of ⁴⁰K and ¹³⁷Cs was lower than the 3-year (2017-2019) average reported by the Korea Institute of Nuclear Safety, respectively. Due to the nature of granite-rich soil, the radioactivity of ⁴⁰K was 0.6-fold higher than in other countries, while ¹³⁷Cs was in the normal fluctuation range (15-30 Bq/kg-dry) of the concentration of radioactive fallout from nuclear tests. The activity of ²²⁶Ra and ²³²Th was lower than in Korean soils reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The average activity concentrations of ²³²Th and ⁴⁰K for the soil and sand samples from DIRAMS were within the range specified by UNSCEAR in 2000. The radium equivalent activity and internal and external hazard index values were below the recommended limits (1 mSv/y). These radionuclide concentration (²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs) data can be used for regional environmental monitoring and ecological impact assessments of nuclear power plant accidents.

Plasmonic nano-necklace arrays <i>via</i> reconstruction of diblock copolymer inverse micelle nanotemplates

Lee, Ji Yong,Lee, Jieun,Jang, Yu Jin,Lee, Juyon,Jang, Yoon Hee,Kochuveedu, Saji Thomas,Lee, Sang Soo,Kim, Dong Ha Royal Society of Chemistry 2011 SOFT MATTER Vol.7 No.1

<P>We present a facile strategy for the generation of plasmonic nano-necklace arrays by introducing metallic precursors into strings of reconstructed inverse micelle nanotemplates which are induced by applying sequential selective solvent treatment and solvent vapour annealing for quasi-hexagonal arrays of poly(styrene-<I>block</I>-2-vinyl pyridine) inverse micelles.</P> <P>Graphic Abstract</P><P>A generalized protocol to fabricate plasmonic nano-necklace arrays with controlled composition was suggested <I>via</I> reconstruction of inverse micelle nanotemplates. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0sm00972e'> </P>

Effects of Hahella chejuensis-Derived Prodigiosin on UV-Induced ROS Production, Inflammation and Cytotoxicity in HaCaT Human Skin Keratinocytes

( Jieun Lee ),( Hyun Ju Kim ),( Sang Jun Lee ),( Moo-seung Lee ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.3

Prodigiosins, which are natural tripyrrole red pigments and synthetic derivatives, reportedly have multiple biological effects mainly on various types of cancer cells. However, the effects of bacterial prodigiosin on non-cancerous HaCaT human skin keratinocytes have not been reported. Therefore, the present study aimed to investigate the functional activities of prodigiosin derived from cultures of the bacterium Hahella chejuensis in HaCaT cells. Cell viability, the cell proliferation rate, and reactive oxygen species (ROS) production in vitro were assayed following treatment of HaCaT cells with prodigiosin. Prodigiosin did not cause cytotoxicity and notably increased proliferation of HaCaT cells. Furthermore, prodigiosin reduced ultraviolet (UV) irradiation-induced ROS production and the inflammatory response in HaCaT cells. More importantly, prodigiosin reduced matrix metalloproteinase-9 expression and increased collagen synthesis in UV-irradiated HaCaT cells, demonstrating that it elicits anti-aging effects. In conclusion, our results reveal that H. chejuensis-derived prodigiosin is a potential natural product to develop functional cosmetic ingredients.

The Tolerability of Mirtazapine Augmentation in Schizophrenic Patients Treated with Risperidone: A Preliminary Randomized Placebo-controlled Trial

Jieun Lee,Sung Joon Cho,Kang Soo Lee,Keunyoung Yook,최아영,Sungjae Lee,김보라,Keung-Hyang Kim,Tae Kyou Choi,이상혁 대한정신약물학회 2011 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.9 No.2

Objective: Some patients with schizophrenia may need mirtazapine augmentation to improve negative and cognitive symptoms. However there have been a few studies about the tolerability of mirtazapine augmentation to antipsychotics such as akathisia,extrapyramydal symptoms, weight gain, and body mass index (BMI). Methods: This study was an eight-week double-blind, randomized controlled trial (RCT) of mirtazapine augmentation to risperidone. Twenty-one stabilized participants diagnosed with schizophrenia and undergoing treatment with risperidone were randomized to adjunctive treatment with mirtazapine (15 mg/day for the first two weeks, 30 mg/day for the next six weeks) or placebo. Eleven patients were assigned to the mirtazapine group, and nine patients were given placebo. Results: There was no significant difference between the mirtazapine and placebo groups with respect to Barnes Akathisia rating Scale (BAS) and Sympsom-Angus Scale (SAS). However, the mirtazapine group exhibited a statistically significant increase in weight and BMI (p<0.05). Conclusion: These results suggest that mirtazapine augmentation can be tolerable in schizophrenic patients treated with risperidone;however, we should pay attention to the weight gain with mirtazapine. Our results should be replicated in a large-scale lengthy trial.

Reporting nationwide monitoring results about high risk pests in 2018

Jieun Lee,Seunghwan Lee,Jong-Seok Park,Hyojoong Kim,Ki-jeong Hong,Chuleui Jung,Dong-soon Kim,Wonhoon Lee 한국응용곤충학회 2019 한국응용곤충학회 학술대회논문집 Vol.2019 No.04

고위험해충에 대한 국내 유입/발생 여부를 상시 조사하고, 조기 대응하는 전국 민·관·학 예찰협력 네트워크 구성을 위하여, 고위험해충 11종(Bactrocera dorsalis, Solenopsis invicta, Cydia pomonella, Drosophila suzukii, Bactrocera depressa, Lobesia botrana, Proeulia sp., Aceria diospyri, Stephaitis takeyai, Bactrocera minax, Bactrocera tsuneonis)에 대하여 7개 대학(경상대학교, 군산대학교, 서울대학교, 순천대학교, 안동대학교, 제주대학교, 충북대학교)이 참여한 전국 권역별 예찰조사를 2018년 6월부터 10월까지 실시하였다. 조사결과, B. dorsalis, S. invicta, C. pomonella은 발견되지 않았으며, D. suzukii (3,584개체), B. depressa (21개체) 채집되었다. 포도, 단감, 감귤의 유입우려해충(L. botrana, P. sp., A. diospyri, S. takeyai, B. minax, B. tsuneonis)은 발견되지 않았다. 본 조사연구를 통하여, 고위험해충을 조기 탐색할 수 있는 7개 대학을 통한 전국단위의 감시체계를 구축하였고, 수출단지 상대국우려병해충 및 수출품목에 대한 정밀 예찰과 관리를 통한 수출지원, 국경 이후 병해충 예찰․관리를 위한 거점 확보의 성과를 이루었다.

The Caenorhabditis elegans AMP-activated protein kinase AAK-2 is phosphorylated by LKB1 and is required for resistance to oxidative stress and for normal motility and foraging behavior.

Lee, Hyojin,Cho, Jeong Soo,Lambacher, Nils,Lee, Jieun,Lee, Se-Jin,Lee, Tae Hoon,Gartner, Anton,Koo, Hyeon-Sook American Society for Biochemistry and Molecular Bi 2008 The Journal of biological chemistry Vol.283 No.22

<P>AAK-2 is one of two alpha isoforms of the AMP-activated protein kinase in Caenorhabditis elegans and is involved in life span maintenance, stress responses, and germ cell cycle arrest upon dauer entry. We found that AAK-2 was phosphorylated at threonine 243 in response to paraquat treatment and that this phosphorylation depends on PAR-4, the C. elegans LKB1 homologue. Both aak-2 mutation and par-4 knockdown increased the sensitivity of C. elegans worms to paraquat, and the double deficiency did not further increase sensitivity, indicating that aak-2 and par-4 act in a linear pathway. Both mutations also slowed body bending during locomotion and failed to reduce head oscillation in response to anterior touch. Consistent with this abnormal motility and behavioral response, expression of the AAK-2::green fluorescent protein fusion protein was observed in the ventral cord, some neurons, body wall muscle, pharynx, vulva, somatic gonad, and excretory cell. Our study suggests that AMPK can influence the behavior of C. elegans worms in addition to its well known function in metabolic control.</P>

Development of Self-Questionnaire for Internal Dose Assessment by Food Ingestion

Lee JiEun,Kim Hyo Jin,Kye Yong-Uk,Lee Dong-Yeon,Jo Wol Soon,Lee Chang-Geun,Kim Jung-Ki,Kang Yeong-Rok 대한방사선방어학회 2022 방사선방어학회지 Vol.47 No.4

Background : The accident at the Fukushima Daiichi nuclear power plant increased the level of anxiety related to the radioactive contamination of various foods sourced in Japan . Particularly, after the accident , the detection of artificial radionuclides in locally produced foods raised food safety concerns . In this study, the radioactivity concentrations and annual ingestions of 40K and 137 Cs in food products commonly and frequently consumed by the general public were investi- gated , and the annual effective dose of each was evaluated . Materials and Methods : The 2016–2018 data from the Radiation Safety Management Report released by the Korea Nuclear Safety Technology Center was referenced for the evaluation of the amounts of 40K and 137Cs contained in food . Using the food-ingestion survey mentioned above as a reference , we selected 62 foods to include in our radioactivity concentration and dose as- sessment . We also developed a questionnaire and evaluated the responses from the subjects who answered the questionnaire . Results and Discussion : The radioactivity concentration of 137Cs was found to be close to or below the level of minimum detectable activity. Additionally, the annual ingestion of 62 foods was 294 . 77 kg/yr, the effective doses from 40K and 137Cs were 136 . 4 and 0 . 163 μSv/yr, respec- tively. Conclusion : Thus , the findings confirmed that the effective dose from 40K and 137Cs in food tends to be lower than the effective dose limit of 1 mSv/yr suggested by the International Com- mission on Radiological Protection (ICRP) Publication 60 . The questionnaire developed in this study is expected to be useful for estimating the annual effective dose status of Korean adults who consume foods containing 40K and 137Cs .