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>

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

Relationship between workplace violence and work-related depression/anxiety, separating the types of perpetrators: a cross-sectional study using data from the fourth and fifth Korean Working Conditions Surveys(KWCS)

Na-Rae Lee,Sang-Woo Kim,Jae-Han Joo,Jae-Han Lee,June-Hee Lee,Kyung-Jae Lee 대한직업환경의학회 2022 대한직업환경의학회지 Vol.34 No.-

Regulation of MDA5-MAVS Antiviral Signaling Axis by TRIM25 through TRAF6-Mediated NF-κB Activation

Lee, Na-Rae,Kim, Hye-In,Choi, Myung-Soo,Yi, Chae-Min,Inn, Kyung-Soo Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.9

Tripartite motif protein 25 (TRIM25), mediates K63-linked polyubiquitination of Retinoic acid inducible gene I (RIG-I) that is crucial for downstream antiviral interferon signaling. Here, we demonstrate that TRIM25 is required for melanoma differentiation-associated gene 5 (MDA5) and MAVS mediated activation of NF-${\kappa}B$ and interferon production. TRIM25 is required for the full activation of NF-${\kappa}B$ at the downstream of MAVS, while it is not involved in IRF3 nuclear translocation. Mechanical studies showed that TRIM25 is involved in TRAF6-mediated NF-${\kappa}B$ activation. These collectively indicate that TRIM25 plays an additional role in RIG-I/MDA5 signaling other than RIG-I ubiquitination via activation of NF-${\kappa}B$.

Effect of house dust mite on neutrophil apoptosis by cytokine secretion in lymphocytes

Lee, Na Rae,Lee, Ji-Sook,Baek, Seung Yeop,Kim, Da Hye,Gu, Ayoung,Kim, Seong Yeol,Lee, Soo Jin,Kim, In Sik THE KOREAN SOCIETY OF TOXICOGENOMICS AND TOXICOPRP 2016 MOLECULAR AND CELLULAR TOXICOLOGY Vol. No.

Although extract of Dermatophagoides farinae (DF) alone had no effect on neutrophil apoptosis, it inhibited neutrophil apoptosis in neutrophils cocultured with lymphocytes in both normal and allergic subjects. DF showed a stronger inhibition on the apoptosis of allergic neutrophils cocultured with allergic lymphocytes than that of normal neutrophils cocultured with normal lymphocytes. DF induced the secretion of IL-6, IL-8, MCP-1, and GM-CSF of the normal and allergic lymphocytes. The cytokine secretion due to DF in allergic lymphocytes is higher than in normal lymphocytes. The cytokine secretion of normal and allergic lymphocytes induced by DF was suppressed by PAR2i, a PAR2 inhibitor, LY294002, a PI3K inhibitor, AKTi, an Akt inhibitor, PD98059, an ERK inhibitor, and BAY-11-7085, an <TEX>$NF-{\kappa}B$</TEX> inhibitor. Phosphorylation of ERK induced by DF was suppressed by PAR2i, LY294002 and AKTi, and <TEX>$NF-{\kappa}B$</TEX> activity due to DF was inhibited by PAR2i, LY294002, AKTi, and PD98059.

Identification of a Technique Optimized for the Isolation of Spermatogonial Stem Cells from Mouse Testes

Na Rae Han,Hye Jin Park,Hyun Lee,Jung Im Yun,Kimyung Choi,Eunsong Lee,Seung Tae Lee 한국수정란이식학회 2018 한국동물생명공학회지 Vol.33 No.4

To date, there are no protocols optimized to the effective separation of spermatogonial stem cells (SSCs) from testicular cells derived from mouse testes, thus hindering studies based on mouse SSCs. In this study, we aimed to determine the most efficient purification method for the isolation of SSCs from mouse testes among previously described techniques. Isolation of SSCs from testicular cells derived from mouse testes was conducted using four different techniques: differential plating (DP), magnetic-activated cell sorting (MACS) post-DP, MACS, and positive and negative selection double MACS. DP was performed for 1, 2, 4, 8, or 16 h, and MACS was performed using EpCAM (MACSEpCAM), Thy1 (MACSThy1), or GFR α1 (MACSGFRα1) antibodies. The purification efficiency of each method was analyzed by measuring the percentage of cells that stained positively for alkaline phosphatase. DP for 8 h, MACSThy1 post-DP for 8 h, MACSGFRα1, positive selection double MACSGFRα1/EpCAM, and negative selection double MACSGFRα1/α-SMA were identified as the optimal protocols for isolation of SSCs from mouse testicular cells. Comparison of the purification efficiencies of the optimized isolation protocols showed that, numerically, the highest purification efficiency was obtained using MACSGFRα1. Overall, our results indicate that MACSGFRα1 is an appropriate purification technique for the isolation of SSCs from mouse testicular cells.

A neonate with Joubert syndrome presenting with symptoms of Horner syndrome

Na Rae Lee,남상욱,김영미,이윤진 대한소아청소년과학회 2016 Clinical and Experimental Pediatrics (CEP) Vol.59 No.no.sup1

Joubert syndrome (JS) is characterized by the “molar tooth sign” (MTS) with cerebellar vermis agenesis, episodic hyperpnea, abnormal eye movements, and hypotonia. Ocular and oculomotor abnormalities have been observed; however, Horner syndrome (HS) has not been documented in children with JS. We present the case of a 2-month-old boy having ocular abnormalities with bilateral nystagmus, left-dominant bilateral ptosis, and unilateral miosis and enophthalmos of the left eye, which were compatible with HS. Brain magnetic resonance imaging (MRI) revealed the presence of the MTS. Neck MRI showed no definite lesion or mass around the cervical sympathetic chain. His global development was delayed. He underwent ophthalmologic surgery, and showed some improvement in his ptosis. To the best of our knowledge, the association of HS with JS has not yet been described. We suggest that early neuroimaging should be considered for neonates or young infants with diverse eye abnormalities to evaluate the underlying etiology.

Detection and quantification of air transparency from industrial air environment

( Na Rae Lee ),( K Yoo ),( H K Son ),( S Sivakumar ) 한국폐기물자원순환학회(구 한국폐기물학회) 2013 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2013 No.-

Digital photography-based technique was developed to quantify plume opacity from digital photographs due to disadvantage of the currently used methods. The present study is designed to simplify the opacity monitoring process by the application of NI Labview program using digitized images from digital camera. The field tests demonstrated that this method have advantages when compared to in-stack transmissometer by their lower cost, improved objectivity, and availability of photographs of the visible emissions and their environments. Method 9 requires that an observer have an individual opacity error (15%) and an average opacity error (7.5%) for plumes during a particular test for the observer to be certified for 6 months. The individual and average opacity errors in the present study when compared to a reference in-stack transmissometer are within USEPA``s error limits for Method 9. These results indicate that both methods have the potential to serve as an alternative method to Method 9 to determine the opacity of plumes for regulatory compliance of stationary sources.

Removal of styrene in biofilter using different load fluctuation as operating parameter

( Na Rae Lee ),( K Yoo ),( H K Son ),( S Sivakumar ) 한국폐기물자원순환학회(구 한국폐기물학회) 2013 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2013 No.-

Biofilters are operated successfully at steady loads of contaminants. Meantime, variations in contaminant load are common in real application. Various studies have indicated the possibility of using a carbon filter for buffering the biofilter. Therefore, in the present study, the performance of biofilter packed with sewage sludge was tested over a period of 100 days under different styrene fluctuating loading condition. The inlet loading rate was varied in this system from 5 to 350 g styrene/m3. The fluctuation inlet loading rate was adjusted manually depends upon the performance of the biofilter i.e., when the styrene outlet removal efficiency was over 95%. The obtained results show that at every step in the increase in the loading rates, it was observed that the biofilter adapted to the new concentration within few days and reached a steady state shortly. The removal efficiencies during this period were 72 to 100%. The proposed procedure is valid to examine the biofiltration behavior used in removal of VOCs.

IS-14 : Estimation of Black Plume Opacity during Dim Condition

( Na Rae Lee ),( K Yoo ),( H K Son ),( S Sivakumar ) 한국폐기물자원순환학회(구 한국폐기물학회) 2013 한국폐기물자원순환학회 추계학술발표논문집 Vol.2013 No.-

Method 9 is a reference method established by U.S. Environmental Protection Agency (EPA) to quantify plume opacity by the certified observer. Later, digital Optical Method (DOM) was developed to quantify plume opacity from digital photographs for bright and dim conditions. However, there is a limitation for the use of Method 9 and DOM to quantify the plume opacity especially for dim condition. In this paper, DIM-DOM system was used instead of DOM to quantify plume opacity during dim condition. Opacity readings provided by DIM-DOM were compared with the opacity values obtained with the reference in-stack transmissometer of the smoke generator. The individual opacity error results demonstrated that DIM-DOM met Method 9`s requirements. The individual opacity values ranging from 0 to 100% compare well to the corresponding opacity results from the in-stack transmissometer results meeting USEPA`s Method 9 IOE requirement of ≤15%. These results are encouraging and indicate that DIM-DOM has the potential to quantify plume opacity during dim condition.