Energy storage capabilities of nitrogen-enriched pyropolymer nanoparticles fabricated through rapid pyrolysis

Yun, Young Soo,Kim, Yu Hyun,Song, Min Yeong,Kim, Na Rae,Ku, Kyojin,An, Ji Su,Kang, Kisuk,Choi, Hyoung Jin,Jin, Hyoung-Joon Elsevier 2016 Journal of Power Sources Vol.331 No.-

<P><B>Abstract</B></P> <P>Nanostructured pyropolymers contain significant amounts of redox-active heteroatoms, have high specific surface areas, and a defective carbon microstructure, indicating good potential for pseudocapacitive charge storage. In this study, nitrogen-enriched pyropolymer nanoparticles (N-PNs-50) are fabricated from polyaniline nanotubes through rapid pyrolysis at 50 °C min<SUP>−1</SUP>. N-PNs-50 exhibit a nitrogen content of 9.8 wt%, a high specific surface area of 875.8 m<SUP>2</SUP> g<SUP>−1</SUP>, and an amorphous carbon structure with an I<SUB> <I>D</I> </SUB>/I<SUB> <I>G</I> </SUB> intensity ratio of 0.95. These unique characteristics lead to good electrochemical performances, in which reversible capacities of 660 and 255 mAh g<SUP>−1</SUP> are achieved for Li-ion and Na-ion storage, respectively, with favorable voltage characteristics (<1.5 V for Li-ions and <1.2 V for Na-ions). This study provides a more feasible production method for nitrogen-doped pyropolymers and their practicable electrochemical performances for use as an anode in energy storage devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanostructured pyropolymers (N-PNs-50) were fabricated by rapid pyrolysis. </LI> <LI> N-PNs-50 exhibited a nitrogen content of 9.8 wt% and amorphous carbon structure. </LI> <LI> N-PNs-50 exhibited a high specific surface area of 875.8 m<SUP>2</SUP> g<SUP>−1</SUP>. </LI> <LI> 660 and 255 mAh g<SUP>−1</SUP> were achieved for Li-ion and Na-ion storage, respectively. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Nitrogen-enriched pyropolymer nanoparticles (N-PNs-50) were fabricated from polyaniline nanotubes through rapid pyrolysis at 50 °C min<SUP>−1</SUP>, showing superior electrochemical performances.</P> <P>[DISPLAY OMISSION]</P>

Hierarchically nanoporous pyropolymer nanofibers for surface-induced sodium-ion storage

Yoon, Hyeon Ji,Lee, Min Eui,Kim, Na Rae,Yang, Seung Jae,Jin, Hyoung-Joon,Yun, Young Soo Pergamon Press 2017 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>Surface-driven charge storage materials based on both electrochemical double layer (EDL) formation and pseudocapacitive behavior can deliver high energy and power capabilities with long-lasting cycling performance. On the other hand, the electrochemical performance is strongly dependent on the material properties, requiring sophisticated electrode design with a high active surface area and a large number of redox-active sites. In this study, hierarchically nanoporous pyropolymer nanofibers (HN-PNFs) were fabricated from electrospun polyacrylonitrile nanofibers by simple heating with KOH. The HN-PNFs have a hierarchically nanoporous structure and an exceptionally high specific surface area of 3,950.7m<SUP>2</SUP> g<SUP>−1</SUP> as well as numerous redox-active heteroatoms (C/O and C/N ratio of 10.6 and 16.8, respectively). These unique material properties of HN-PNFs resulted in high reversible Na-ion capacity of ∼292mAhg<SUP>−1</SUP> as well as rapid kinetics and stable cycling performance in the cathodic potential range (1-4.5V vs. Na<SUP>+</SUP>/Na). Furthermore, energy storage devices based on HN-PNFs showed a remarkably high specific energy of ∼258 Wh kg<SUP>−1</SUP> at ∼245Wkg<SUP>−1</SUP> as well as a high specific power of ∼21,500Wkg<SUP>−1</SUP> at ∼78 Wh kg<SUP>−1</SUP>, with long and stable cycling behaviors over 2,000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hierarchically nanoporous pyropolymer nanofibers (HN-PNFs) were fabricated. </LI> <LI> HN-PNFs have a high specific surface area of ∼3,950m<SUP>2</SUP> g<SUP>−1</SUP> and numerous heteroatoms. </LI> <LI> HN-PNFs exhibit high capacities of ∼292mAhg<SUP>−1</SUP> and great rate/cycling performances. </LI> <LI> High energy (258Whkg<SUP>−1</SUP>) and high power (21,500Wkg<SUP>−1</SUP>) are achieved. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Hierarchically nanoporous pyropolymer nanofibers (HN-PNFs) fabricated from electrospun polyacrylonitrile nanofibers by simple heating with KOH exhibited high electrochemical performance for Na-ion storage.</P> <P>[DISPLAY OMISSION]</P>

난치성 간질로 절제한 대뇌피질의 병리소견에 대한 소아군과 성인군의 비교:164예의 분석

김나래,서연림 대한병리학회 1999 Journal of Pathology and Translational Medicine Vol.33 No.12

전격성 제1형 당뇨병 1예

노동현,김도형,김나래,박종선,이창헌,김미경,최영식 고신대학교의과대학 2007 고신대학교 의과대학 학술지 Vol.22 No.2

전격성 제1형 당뇨병은 특발성 당뇨병환자에서 임상 경과가 짧고 진단 당시 심각한 대사 합병증을 동반하면서 췌장 효소 수치가 높고 췌도 특이 자가항체가 음성인 새로운 아형으로 알려져 있으며, 일본과 일본 외에서의 유병률에는 차이가 있는 것으로 보인다. 아직 전격성 제1형 당뇨병의 발생 기전은 명확하지 않으며 유전적 감수성이 있는 개체에서 바이러스 감염 등의 환경적인 인자와의 연관성이 가능한 병태생리로 제시되고 있으며 이에 대한 추가적인 연구가 요구된다. 저자들은 케톤산증으로 내원하여 전격성 제1형 당뇨병을 진단받은 증례를 경험하였기에 문헌고찰과 함께 보고 하는 바이다. Some patients with idiopathic type 1 diabetes have a fulminant disorder characterized by the absence of insulitis and of diabetes-related antibodies, a remarkably abrupt onset and high serum pancreatic enzyme concentrations. This is referred to as fulminant type 1 diabetes. A 29-year-old man suffering from abdominal pain, nausea and vomiting consulted to our hospital. Laboratory findings revealed high blood glucose level and the evidence of diabetic ketoacidosis, but the serum HbA1c was normal nevertheless. The low level of plasma C-peptide indicated the loss of endogenous insulin secretion. The patient satisfied the criteria for the diagnosis of fulminant type 1 diabetes. After the patient has been treated with insulin, his symptoms were improved and abnormal laboratory data were normalized. We report this case with a review of the literature

팽대부주위 암종에서 Cytokeratin 7과 20의 발현

최종순,감나래,안긍환,박철근 대한병리학회 2000 Journal of Pathology and Translational Medicine Vol.34 No.1

Inhibitory effect of arazyme on the development of atopic dermatitis-like lesions in BALB/c and Nc/Nga mice.

Kim, In Sik,Lee, Na Rae,Baek, Seung Yeop,Kim, Eun Jeong,Kim, Jung Seok,Jeong, Tae-Sook,Shin, Dong-Ha,Park, Ho-Yong,Lee, Ji-Sook SPANDIDOS PUBLICATIONS 2015 MOLECULAR MEDICINE REPORTS Vol.11 No.5

<P>Arazyme is a metalloprotease released by Aranicola proteolyticus that was shown to inhibit cytokine release in HaCaT and endothelial cells. However, the regulatory effects of arazyme in atopic dermatitis remain to be fully understood. In the present study, the anti?inflammatory effects of arazyme in BALB/c and Nc/Nga mice induced with 2,4?dinitrochlrobenzene (DNCB) were investigated. BALB/c mice were sensitized with DNCB and were subsequently administered arazyme for 4 weeks either orally, dorsally or orally/dorsally. Arazyme administration significantly reduced epidermal thickening and infiltration of inflammatory cells into the dermis compared with the DNCB group. However, serum immunoglobulin E (IgE) levels were not altered by arazyme treatment. Additionally, the level of secretion of interleukins (IL)?4, ?5 and ?13 in the splenocytes of BALB/c mice was elevated following stimulation with concanavalin A, while the increase of IL?4 and IL?13 was inhibited by arazyme. Administration of arazyme (25 mg/kg in phosphate?buffered saline) to Nc/Nga mice that had been sensitized with DNCB for 6 weeks reduced the skin severity score compared with that in the DNCB group and inhibited the histological manifestations of atopic dermatitis?like skin lesions. In addition, the serum IgE levels were reduced in the arazyme?treated NC/Nga mice relative to the DNCB group. Collectively, these results indicated that arazyme attenuates the development of atopic dermatitis?like lesions via lowering the levels of IgE and inflammatory cytokines. The results of the present study will aid in the development of effective therapeutic strategies for the treatment of allergic diseases, including atopic dermatitis.</P>

NJK14013, a novel synthetic estrogen receptor-α agonist, exhibits estrogen receptor-independent, tumor cell-specific cytotoxicity

KIM, HYE-IN,KIM, TAELIM,KIM, JI-EUN,LEE, JUN,HEO, JINYUK,LEE, NA-RAE,KIM, NAM-JUNG,INN, KYUNG-SOO Spandidos Publications 2015 International journal of oncology Vol.47 No.1

<P>Estrogens act through interactions with estrogen receptors (ERs) to play diverse roles in various pathophysiological conditions. A number of synthetic selective estrogen receptor modulators (SERMs), such as tamoxifen and raloxifene, have been developed and used to treat ER-related diseases, including breast cancer and osteoporosis. Here, we identified a novel compound, bis(4-hydroxyphenyl) methanone-O-isopentyl oxime, designated NJK14013, as an ER agonist. NJK14013 activated ER-dependent transcription in a concentration-dependent manner, while suppressing androgen receptor-dependent transcriptional activity. It induced the activation-related phosphorylation of ER and enhanced the transcription of growth regulation by estrogen in breast cancer 1 (GREB1), further supporting its ER-stimulating activity. NJKI4013 exerted anti-proliferative effects on various cancer cell lines, including an ER-negative breast cancer cell line, suggesting that it is capable of suppressing the growth of cancer cells independent of its ER-modulating activity. In addition, NJKI4013 treatment resulted in significant apoptotic death of MCF7 and Ishikawa cancer cells, but did not induce apoptosis in non-cancer human umbilical vein endothelial cells. Collectively, our findings demonstrate that NJK 14013 is a novel SERM that can activate ER-mediated transcription in MCF7 cells and suppress the proliferation of various cancer cells, including breast cancer cells and endometrial cancer cells. These results suggest that NJK14013 has potential as a novel SERM for anticancer or hormone-replacement therapy with reduced risk of carcinogenesis.</P>

Ag–Cu Bimetallic Nanoparticles with Enhanced Resistance to Oxidation: A Combined Experimental and Theoretical Study

Kim, Na Rae,Shin, Kihyun,Jung, Inyu,Shim, Moonsub,Lee, Hyuck Mo American Chemical Society 2014 The Journal of Physical Chemistry Part C Vol.118 No.45

<P>A simple oleylamine-based thermal decomposition process using different time steps for precursor injection was used to obtain bimetallic Ag–Cu nanoparticles with a narrow size distribution. Experimental and theoretical studies were carried out to demonstrate that these bimetallic nanoparticles are less prone to oxidation. The calculated energy trends for O<SUB>2</SUB> adsorption on the nanoparticles show that the adsorption energy declines rapidly when more than six O<SUB>2</SUB> molecules are present, indicating that O<SUB>2</SUB> is rarely adsorbed on Ag–Cu nanoparticles. Electron transfer from Cu to Ag within these bimetallic nanoparticles allows far better resistance to oxidation than monometallic Cu nanoparticles.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2014/jpccck.2014.118.issue-45/jp506069c/production/images/medium/jp-2014-06069c_0010.gif'></P>

Symbol Interval Optimization for Molecular Communication With Drift

Na-Rae Kim,Eckford, Andrew W.,Chan-Byoung Chae IEEE 2014 IEEE transactions on nanobioscience Vol.13 No.3

<P>In this paper, we propose a symbol interval optimization algorithm in molecular communication with drift. Proper symbol intervals are important in practical communication systems since information needs to be sent as fast as possible with low error rates. There is a trade-off, however, between symbol intervals and inter-symbol interference (ISI) from Brownian motion. Thus, we find proper symbol interval values considering the ISI inside two kinds of blood vessels, and also suggest no ISI system for strong drift models. Finally, an isomer-based molecule shift keying (IMoSK) is applied to calculate achievable data transmission rates (achievable rates, hereafter). Normalized achievable rates are also obtained and compared in one-symbol ISI and no ISI systems.</P>

Inhibitory Effects of <i>Chrysanthemum boreale</i> Essential Oil on Biofilm Formation and Virulence Factor Expression of <i>Streptococcus mutans</i>

Kim, Beom-Su,Park, Sun-Ju,Kim, Myung-Kon,Kim, Young-Hoi,Lee, Sang-Bong,Lee, Kwang-Hee,Choi, Na-Young,Lee, Young-Rae,Lee, Young-Eun,You, Yong-Ouk Hindawi Publishing Corporation 2015 Evidence-based Complementary and Alternative Medic Vol.2015 No.-

<P>The aim of the study was to evaluate the antibacterial activity of essential oil extracted from <I>Chrysanthemum boreale</I> (<I>C. boreale</I>) on <I>Streptococcus mutans</I> (<I>S. mutans</I>). To investigate anticariogenic properties, and bacterial growth, acid production, biofilm formation, bacterial adherence of <I>S. mutans</I> were evaluated. Then gene expression of several virulence factors was also evaluated. <I>C. boreale</I> essential oil exhibited significant inhibition of bacterial growth, adherence capacity, and acid production of <I>S. mutans</I> at concentrations 0.1–0.5 mg/mL and 0.25–0.5 mg/mL, respectively. The safranin staining and scanning electron microscopy results showed that the biofilm formation was also inhibited. The result of live/dead staining showed the bactericidal effect. Furthermore, real-time PCR analysis showed that the gene expression of some virulence factors such as <I>gtf</I>B, <I>gtf</I>C, <I>gtf</I>D, <I>gbp</I>B, <I>spa</I>P, <I>brp</I>A, <I>rel</I>A, and <I>vic</I>R of <I>S. mutans</I> was significantly decreased in a dose dependent manner. In GC and GC-MS analysis, seventy-two compounds were identified in the oil, representing 85.42% of the total oil. The major components were camphor (20.89%), <I>β</I>-caryophyllene (5.71%), <I>α</I>-thujone (5.46%), piperitone (5.27%), <I>epi</I>-sesquiphellandrene (5.16%), <I>α</I>-pinene (4.97%), 1,8-cineole (4.52%), <I>β</I>-pinene (4.45%), and camphene (4.19%). These results suggest that <I>C. boreale</I> essential oil may inhibit growth, adhesion, acid tolerance, and biofilm formation of <I>S. mutans</I> through the partial inhibition of several of these virulence factors.</P>