Mole-controlled growth of Y-doped ZnO nanostructures by hydrothermal method

Heo, S.,Lee, Y.,Sharma, S.K.,Lee, S.,Kim, D.Y. Elsevier 2014 Current Applied Physics Vol.14 No.11

We investigated the mole-controlled growth of Y-doped ZnO (YZO) nanostructures by the hydrothermal synthesis techniques. Through controlling the aqueous solution's mole concentration, we could modify the morphological and structural properties of YZO. The shape of YZO becomes a nanometer-sized rod when using a relatively low mole concentration, whereas the morphology is changed to be flat and mosaic when using a relatively high mole concentration. Since the aqueous solution's mole concentration decides the amount of hydroxide, we ascribe the mole-controlled morphological changes to the alteration of chemical potential during the hydrothermal chemical reaction.

대학생의 인터넷중독 및 스마트폰 중독 정도와 미술 치료 인식에 대한 조사 연구

박혜원,송승윤,윤하영,이경현,이소영,이지원,진예은,최시온,허은서,황다빈,신주현,이인영 이화여자대학교 간호학회 2018 이화간호학회지 Vol.- No.52

Purpose: Investigate the level of Internet and smart phone addiction of college students and difference of their perception on the art therapy. Method: Data was collected using 4 categories of questionnaires. Participants of this study were 383 college students who are currently attending universities located in seoul, Kyung-Ki and Incheon. The Chi-square test, One-way Analysis of Variance, Scheffé test were performed using IBM SPSS Statistics 23.0 Result: First, the study has established that the status of attending universities, grade, people who living with, age affected the level of Internet addiction of college students. In terms of the level of smart phone addiction of college students, the status of attending universities, gender, age were the affective factors. Second, there was a significant difference on the perception of the advantages of the art therapy and the level of acknowledging it, depending on the level of Internet addiction. Finally, depending on the level of smartphone addiction, there was a significant difference in the level of perception of the art therapy, expectation toward the art therapy and the helpfulness of art therapy. The more the participants are close to the addicted level, the more they want to experience the art therapy. Conclusion: These results suggest. First, it is necessary to use bigger group of participants. Second, it is necessary to improve the research methods for college students. Third, nurse should offer holistic care toward the patients regarding their general characteristics by adapting this study. Finally, it is necessary to improve the art therapy programs for the college students who are addicted to the Internet and smartphone and to develop researches proving the effectiveness of these programs.

Wound healing potential of antibacterial microneedles loaded with green tea extracts

Park, S.Y.,Lee, H.U.,Lee, Y.C.,Kim, G.H.,Park, E.C.,Han, S.H.,Lee, J.G.,Choi, S.,Heo, N.S.,Kim, D.L.,Huh, Y.S.,Lee, J. Elsevier 2014 Materials Science and Engineering C Vol.42 No.-

This study evaluates the utility of an antibacterial microneedle composed of green tea (GT) extract and hyaluronic acid (HA), for the efficient delivery of GT. These microneedles have the potential to be a patient-friendly method for the conventional sustained release of drugs. In this study, a fabrication method using a mold-based technique to produce GT/HA microneedles with a maximum area of ~50mm<SUP>2</SUP> with antibacterial properties was used to manufacture transdermal drug delivery systems. Fourier transform infrared (FTIR) spectrometry was carried out to observe the potential modifications in the microneedles, when incorporated with GT. The degradation rate of GT in GT/HA microneedles was controlled simply by adjusting the HA composition. The effects of different ratios of GT in the HA microneedles were determined by measuring the release properties. In HA microneedles loaded with 70% GT (GT70), a continuous higher release rate was sustained for 72h. The in vitro cytotoxicity assays demonstrated that GT/HA microneedles were not generally cytotoxic to Chinese hamster ovary cells (CHO-K1), human embryonic kidney cells (293T), and mouse muscle cells (C2C12), which were treated for 12 and 24h. Antimicrobial activity of the GT/HA microneedles was demonstrated by ~95% growth reduction of gram negative [Escherichia coli (E. coli), Pseudomonas putida (P. putida), and Salmonella typhimurium (S. typhimurium)] and gram positive bacteria [Staphylococcus aureus (S. Aureus) and Bacillus subtilis (B. subtilis)], with GT70. Furthermore, GT/HA microneedles reduced bacterial growth of infected wound sites in the skin and improved wound healing process of skin in rat model.

가족공동체를 떠난 간호대학생들의 대학생활체험

김고은,김유은,김희진,조유진,안주영,허다연,홍서우,차지영,박송이 이화여자대학교 간호학회 2018 이화간호학회지 Vol.- No.52

Purpose: The purpose of this study was to understand and explain the experiences of college life among junior nursing students who live apart from their families. Methods: 14 junior nursing students living apart from their families for at least one semester were recruited through snowballing and convenience sampling. Participants were interviewed individually using open ended questions. Data were collected from July to October in 2017 until data saturation. Interviews were transcribed verbatim and analyzed by using hermeneutic phenomenological method proposed by van Manen. Results: Five essential theme clusters emerged: (1) faced with diverse problems while living apart from family, (2) depend on family when stressed, (3) adapt to college life by being independent and forming self-initiative lifestyle, (4) confront with difficulties once again when adapting to academic curriculum restructured by practicum, (5) pave the way to nursing career and feel proud of overcoming the difficulties independently. Conclusion: Although most participants faced diverse problems in college life, they tried to adapt independently by forming self-initiative lifestyle and overturn the difficulties to positive experiences. In conclusion, the process of living apart from families transformed participants into proactive individuals. Adopting counseling programs could support starting their junior years successfully.

Rational Design of Low Cost and High Energy Lithium Batteries through Tailored Fluorine-free Electrolyte and Nanostructured S/C Composite

Agostini, M.,Lim, D.-H.,Sadd, M.,Hwang, J.-Y.,Brutti, S.,Heo, J. W.,Ahn, J. H.,Sun, Y. K.,Matic, A. Wiley (John WileySons) 2018 ChemSusChem Vol.11 No.17

<P>We report a new Li-S cell concept based on an optimized F-free catholyte solution and a high loading nanostructured C/S composite cathode. The Li2S8 present in the electrolyte ensures both buffering against active material dissolution and Li+ conduction. The high S loading is obtained by confining elemental S (approximate to 80%) in the pores of a highly ordered mesopores carbon (CMK3). With this concept we demonstrate stabilization of a high energy density and excellent cycling performance over 500 cycles. This Li-S cell has a specific capacity that reaches over 1000 mA hg(-1), with an overall S loading of 3.6 mg cm(-2) and low electrolyte volume (i.e., 10 mu L cm(-2)), resulting in a practical energy density of 365 Wh kg(-1). The Li-S system proposed thus meets the requirements for large scale energy storage systems and is expected to be environmentally friendly and have lower cost compared with the commercial Li-ion battery thanks to the removal of both Co and F from the overall formulation.</P>

음이온 치환을 이용한 Li_1-xFeO_2-yF_y-Li_xMnO₂ (Mn/(Mn + Fe) = 0.8, 0≤y≤0.15) 양극 활물질의 합성 및 전기화학적 특성

허정배,박금재,이윤성,Heo, J.B.,Park, G.J.,Lee, Y.S. 한국전기화학회 2007 한국전기화학회지 Vol.10 No.4

산소자리에 치환된 불소가 $Li_{1-x}FeO_2Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8) 양극 활물질에 미치는 영향을 고찰하기 위해 다양한 양의 불소를 치환시킨 $Li_{1-x}FeO_{2-y}F_y-Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8, $0.05{\le}y{\le}0.15$) 양극 활물질을 고상법을 이용하여 합성하였다. 불소 미치환 시료 및 치환양이 0.05와 0.1의 시료의 경우, $1-1.5\;{\mu}m$ 크기의 막대 형상 분말 형태에 50-100 nm정도의 작은 구형 입자들이 주위에 분포되어 있는 형태이었다. 반면, 불소 치환양이 0.15인 시료의 경우, 그 모양이 구형으로 변화되어지며 입자가 급격하게 성장하였다. 합성된 시료를 이용하여 제작된 셀들의 충 방전 수행 결과, $Li/Li_{1-x}FeO_{1.9}F_{0.1}-Li_xMnO_2$ 셀이 163 mAh/g의 가장 높은 초기용량을 보였으며 50 싸이클 후에도 95%의 높은 가역 특성을 보였다. 특히, 활물질내의 불소 치환양이 증가할수록 초기 방전용량도 같이 증가하였으나, 불소이온의 치환양이 일정량을 (y>0.1) 넘는 경우에는 산소 자리에 불소이온이 완전하게 치환되지 못하고 불순물로 존재함으로써 전지의 가역특성을 현저하게 저하시키는 요인으로 작용함을 확인하였다. In order to investigate the effect of fluorine ion in the $Li_{1-x}FeO_2Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8) cathode material, it was synthesized $Li_{1-x}FeO_{2-y}F_y-Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8, $0.05{\le}y{\le}0.15$) cathode materials at $350^{\circ}C$ for 10hrs using solid-state method. $Li_{1-x}FeO_{2-y}F_y-Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8, $0.0{\le}y{\le}0.1$ was composed many large needle-like particles of about $1-1.5\;{\mu}m$ and small particles of about 50-100 nm, which were distributed among the larger particles. However, $Li_{1-x}FeO_{1.85}F_{0.15}-Li_xMnO_2$ material showed slightly different particle morphology. The particles of $Li_{1-x}FeO_{1.85}F_{0.15}-Li_xMnO_2$ were suddenly increased and started to be a spherical type of particle shape. $Li/Li_{1-x}FeO_{1.9}F_{0.1}-Li_xMnO_2$ cell showed a high initial discharge capacity of 163 mAh/g and a high cycle retention rate of 95% after 50 cycles. The initial discharge capacity of $Li/Li_{1-x}FeO_{2-y}F_y-Li_xMnO_2$ ($0.05{\le}y{\le}0.15$) cells increased according to the increase of F content. However, the cycleability of this cell was very rapidly decreased when the substituted fluorine content is over 0.1. We suggested that too large amount of F ion fail to substitute into the $Li_{1-x}FeO_2-Li_xMnO_2$ structure, which resulted in the severe decline of battery performance.

20대 성인의 페이스북 이용행태에 따른 사회비교 경향성, 우울,자아존중감

김지원,남궁빈,안해정,권햇살,한예슬,허진성,김고은,김수진,김미혜,이수인 이화여자대학교 간호과학대학 2015 이화간호학회지 Vol.- No.49

Purpose: The purpose of this study was to explore the differences among social comparison orientation, depression, and self-esteem by patterns of using Facebook among Facebook users’ in their 20s. Methods: The participants in this descriptive study were 332 Facebook users in their 20s. Data collection took place between August 21 and 27, 2014. Questionnaires were the Iowa–Netherlands Comparison Orientation Measure (revised), Center for Epidemiologic Studies Depression Scale, and Rosenberg Self-Esteem Scale. Data were statistically analyzed using t-tests and ANOVAs. Result: Each mean score of social comparison, depression, and self-esteem was 26.04±6.82, 31.39±8.99 and 38.05±6.19. Significant differences emerged between the degree of social comparison and the following Facebook usage variables: average single-connection time to Facebook (F=3.570, p=.007) and self-evaluation of Facebook usage behavior (F=6.203, p<.001). Conclusion: The results of this study suggested that Facebook users in their 20s who access Facebook for long periods and assess themselves as using it more often had a high score of comparison orientation. This result can be used in Nursing by developing the theoretical basis for education and campaign related to Facebook usage. In-depth studies are needed for research on the effect social comparison has on Facebook users and relationships between social comparison and emotions.

Rice serine/threonine kinase 1 is required for the stimulation of OsNug2 GTPase activity

Heo, J.B.,Lee, Y.M.,Yun, H.R.,Im, C.H.,Lee, Y.S.,Yi, Y.B.,Kwon, C.,Lim, J.,Bahk, J.D. G. Fischer 2014 Journal of plant physiology Vol.171 No.17

Several GTPases are required for ribosome biogenesis and assembly. We recently identified rice (Oryza sativa) nuclear/nucleolar GTPase 2 (OsNug2), a YlqF/YawG family GTPase, as having a role in pre-60S ribosomal subunit maturation. To investigate the potential factors involved in regulating OsNug2 function, yeast two-hybrid screens were performed using OsNug2 as bait. Rice serine/threonine kinase 1 (OsSTK1) was identified as a candidate interacting protein. OsSTK1 appeared to interact with OsNug2 both in vitro and in vivo. OsSTK1 was found to have no effect on the GTP-binding activity of OsNug2; however, the presence of recombinant OsSTK1 in OsNug2 assay reaction mixtures increased OsNug2 GTPase activity. A kinase assay showed that OsSTK1 had weak autophosphorylation activity and strongly phosphorylated serine 209 of OsNug2. Using yeast complementation testing, we identified a GAL::OsNug2(S209N) mutation-harboring yeast strain that exhibited a growth-defective phenotype on galactose medium at 39<SUP>o</SUP>C, which was divergent from that of a yeast strain harboring GAL::OsNug2. The intrinsic GTPase activity of OsNug2(S209N), which was found to be similar to that of OsNug2, was not fully enhanced upon weak binding of OsSTK1. Our findings indicate that OsSTK1 functions as a positive regulator of OsNug2 by enhancing OsNug2 GTPase activity. In addition, phosphorylation of OsNug2 serine 209 is essential for its complete function in biological functional pathway.

간호대생들의 임상실습 스트레스, 학업적 자기효능감 및 진로정체감에 대한 연구

최유빈,최민지,이은형,이연우,우소연,하희주,허예지,박수현,허미래,이가현 이화여자대학교 간호과학대학 2015 이화간호학회지 Vol.- No.49

Purpose: The purpose of this study was to investigate clinical practice stress, academic self-efficacy, and career identity among undergraduate students in nursing practicum. Method: This study was a descriptive correlational design using the survey method. The study included 267 undergraduate students attending to 5 college in Seoul. The data was gathered from August 2014 to October 2014 and the data were analyzed using IBM SPSS statistics version 22.0 Program with descriptive statistics, t-test, analysis of variance with Scheffe test, and Pearson’s correlation coefficient. Results: Situational characteristics of Clinical Practice Stress(CPP) was significantly different with regards to task difficulties and efficacy self-confidence of academic self-efficacy(ASE) (r= .179, p= .003; r= .166, p= .006). Statistically significant positive relationship was founded between Personal characteristics of CPP and self-confidence of ASE (r= .239, p< .01). External regulators of CPP was significantly different according to self-confidence and task difficulties (r= .175, p= .003; r= .132, p= .028). The self-confidence and efficacy for self-confidence of ASE were a significantly correlated with Career Identity; The Career identity also was a significantly correlated with all sub-categories of CSS scale(r= -0.208, p< 0.01; r= -0.369, p< 0.01; r= -0.153, p< .011) Conclusion: This study showed positive statistical relationships associated with clinical practice stress, academic self-efficacy, and career identity as a preliminary evidence-based study for guiding education in nursing curriculum. Further research should be need for students’ future as a professional nurse.

시뮬레이티드 어닐링을 이용한 젖소의 급이량 산정

허은영,김동원,한병성,김용준,이수영 한국농업기계학회 2002 바이오시스템공학 Vol.27 No.5