질산화 작용이 있는 Aeromonas hydrophila의 동정 및 특성

엄미나,장재철,유영희,지의상 한국식품영양학회 2000 韓國食品營養學會誌 Vol.13 No.6

폐수처리 중 생물학적 처리에 활용할 수 있는 질소분해 능력을 가진 미생물을 분리하여 동정하고자 경기도내 하천 6지점에서 채취한 시료로부터 50개 균주를 선별하였다. 형태학적, 생화학적 및 배양학적 실험결과 Bergey's mannual of systematic bacteriology의 색인을 통하여 Aeromonas hydrophila로 동정하였다. Aeromonas hydrophila(AH-1). (AH-3), (AH-4), (AH-6) 균이 질산화 능력이 우수하였다. 4개 균주 모두 amoxillin, ampicillin, cephalothin과 ticarcillin에 내성을 나타내었다. 본 실험에서 분리한 .Aeromonas hydrophila의 질산화의 최적조건은 균 농도 1.0×l0exp(6) cells/ml, 배양온도 37℃로 나타났다. For the purpose of the isolation of microorganisms which have the capability of nitrification, we isolated the microorganisms in 6 samples collected from the stream of Kyonggi area. 60 strains were isolated. The selected strain were identified as a Aeromonas hydrophila based on the data obtained from the morphological, biochemical and cultural characteristics defined experiments. Among them Aeromonas hydrophila (AH-1), (AH-3), (AH-4), (AH-6) showed the highest nitrification capability. All isolates were resistant to amoxillin, ampicillin, cephalothin and ticarcillin. Optimum culture conditions of isolates were 37℃ and 1×10exp(8) cells/ml for 4 hours in the nitrate medium.

Preparation of new natural silk non-woven fabrics by using adhesion characteristics of sericin and their characterization

Lee, Ji Hye,Bae, Yeon Su,Kim, Su Jin,Song, Dae Woong,Park, Young Hwan,Bae, Do Gyu,Choi, Jin Hyun,Um, In Chul ELSEVIER 2018 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES Vol.106 No.-

<P><B>Abstract</B></P> <P>Electro-spun regenerated silk webs have been extensively studied for biomedical applications because of the simplicity of their fabrication methods However, the productivity of the electro-spinning process is low for web fabrication and the mechanical properties of the electro-spun silk web are not satisfactory, which restricts its commercialization. In this study, a new silk non-woven fabric was successfully fabricated by wetting and hot press treatments using the excellent binding characteristic of sericin. The effects of the press temperature and residual sericin content on the preparation, structure, and properties of the silk non-woven fabric were examined. A press temperature of 200°C was optimum for obtaining non-woven fabrics with best mechanical properties, without yellowing. The silk non-woven fabric could not be fabricated without sericin, and a minimum of 8% sericin was required to fabricate it. As the sericin content was increased, the strength and Young’s modulus of the silk non-woven fabric increased, while the tensile elongation remained constant. Regardless of the press temperature and sericin content, all the silk non-woven fabrics showed good cell viability, comparable to that of the tissue culture plate (TCP) used as a control until 4days, which however decreased compared to that of TCP after 7days.</P>

Effect of Empowerment on Perceived Person-Environment Fit and Work Engagement: Focusing on Online Travel Platform Employees

Ji-Young Um(Ji-Young Um),Hye-Yeon Park(Hye-Yeon Park),Sun-Young Yoon(Sun-Young Yoon) The International Academy of Global Business and T 2023 The International Academy of Global Business and T Vol.19 No.1

Purpose - COVID-19 has dramatically changed the business landscape, and the travel industry is no exception. The industry is undergoing a paradigm shift to the platform business, and traditional travel agencies are moving their businesses to online platforms. However, in this irreversible global paradigm shift, it is not easy for travel companies to hire and retain employees, especially companies in the IT sector. Studies typically study consumers, such as selection attributes and satisfaction with travel platforms. However, to the best of our knowledge, there have been almost no studies on employees. This study explored how the empowerment of online travel platform employees influences their perceived person-environment (P-E) fit and work engagement. Design/Methodology/Approach - We analyzed data from 352 employees of 26 domestic online travel platforms who were surveyed in January and February 2021. After coding the collected data, we analyzed it using frequency, exploratory factor, reliability, correlation, and multiple regression analyses using IBM SPSS Statistics, ver. 20.0. Findings - First, enhancing the meaningfulness of work and organizational autonomy influences personjob (P-J) fit and person-organization (P-O) fit. Second, enhancing the meaningfulness of work significantly influences vigor, dedication, and absorption in terms of work engagement, while organizational autonomy significantly influences work engagement vigor. Third, P-J fit and P-O fit influence the vigor of work engagement, and P-O fit influences dedication and absorption. Research Implications - This study demonstrated that the empowerment of travel platform employees can improve perceived P-E fit and work engagement. Thus, if organizations guarantee some degree of empowerment, employees will be energized and engaged more in their workplace. Finally, this helps expand the scope of online travel platform research from the perspective of personnel organization.

스마트팜 혁신밸리 입주 청년농업인의 경영성과 분석

심근호,황금영,이소영,엄지범,Geun Ho Shimg,Geum Yeong Hwang,So Young Lee,Ji Bum Um 국립한국농수산대학교 교육개발센터 2024 현장농업연구지 = Journal of practical agricultural resear Vol.25 No.4

This study analyzed the profitability and diagnosed business performance of fruit and vegetable (cherry tomatoes, tomatoes, strawberries, cucumbers) businesses targeting young farmers participating in the youth business incubation center of A Smart Farm Innovation Valley. The purpose of this is to provide basic data for decision-making by prospective young entrepreneurs. As a result of the analysis, Smart Farm Innovation Valley had the advantage of having a fixed rental fee. As a result, it was analyzed that various costs such as depreciation of large farm equipment, depreciation of farming facilities, repair and maintenance costs, land rent, floating capital service cost, fixed capital service cost, and land capital service cost are being reduced. However, excessive input of labor, water, electricity, other materials, and fertilizer costs was being made. Guidance to reduce these costs is expected to make a significant contribution to expanding the influx of young farmers.

Dissection of Activation Parameters in the Bell-Shaped α-Effect Following Solvent Modulation (DMSO–H₂O Media)

Um, Ik-Hwan,Kang, Ji-Sun,Kim, Min-Young,Buncel, Erwin American Chemical Society 2013 Journal of organic chemistry Vol.78 No.17

<P>This paper comprises results of our investigation of the α-effect phenomenon for the reaction of <I>O-p</I>-nitrophenyl thionobenzoate (PNPTB) with butane-2,3-dione monoximate (Ox<SUP>–</SUP>, α-nucleophile) and <I>p</I>-chlorophenoxide (<I>p</I>-ClPhO<SUP>–</SUP>, normal-nucleophile) in DMSO–H<SUB>2</SUB>O mixtures of varying compositions at 15.0 °C, 25.0 °C, and 35.0 °C. The reactivity of Ox<SUP>–</SUP> and <I>p</I>-ClPhO<SUP>–</SUP> increases significantly as the DMSO content in the medium increases, although the effects of medium on reactivity are not the same for the reactions with Ox<SUP>–</SUP> and <I>p</I>-ClPhO<SUP>–</SUP>. Ox<SUP>–</SUP> exhibits the α-effect in all solvent compositions and temperatures. The α-effect increases up to 50 mol % DMSO and then decreases thereafter, resulting in a bell-shaped α-effect profile. Dissection of the activation parameters (i.e., Δ<I>H</I><SUP>⧧</SUP> and <I>T</I>Δ<I>S</I><SUP>⧧</SUP>) has revealed that the bell-shaped α-effect behavior is due to entropy of activation differences rather than enthalpy terms, although the enthalpy term controls almost entirely the solvent dependence of the reaction rate. Differences in the transition-state (TS) structures for the reactions with Ox<SUP>–</SUP> (a six-membered cyclic TS) and <I>p</I>-ClPhO<SUP>–</SUP> (an acyclic TS) are consistent with the entropy-dependent α-effect behavior.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/joceah/2013/joceah.2013.78.issue-17/jo401415f/production/images/medium/jo-2013-01415f_0008.gif'></P>

A Kinetic Study on Nucleophilic Displacement Reactions of Aryl Benzenesulfonates with Potassium Ethoxide: Role of K⁺ Ion and Reaction Mechanism Deduced from Analyses of LFERs and Activation Parameters

Um, Ik-Hwan,Kang, Ji-Sun,Shin, Young-Hee,Buncel, Erwin American Chemical Society 2013 Journal of organic chemistry Vol.78 No.2

<P>Pseudofirst-order rate constants (<I>k</I><SUB>obsd</SUB>) have been measured spectrophotometrically for the nucleophilic substitution reactions of 2,4-dinitrophenyl X-substituted benzenesulfonates <B>4a</B>–<B>f</B> and Y-substituted phenyl benzenesulfonates <B>5a</B>–<B>k</B> with EtOK in anhydrous ethanol. Dissection of <I>k</I><SUB>obsd</SUB> into <I>k</I><SUB>EtO<SUP>–</SUP></SUB> and <I>k</I><SUB>EtOK</SUB> (i.e., the second-order rate constants for the reactions with the dissociated EtO<SUP>–</SUP> and ion-paired EtOK, respectively) shows that the ion-paired EtOK is more reactive than the dissociated EtO<SUP>–</SUP>, indicating that K<SUP>+</SUP> ion catalyzes the reaction. The catalytic effect exerted by K<SUP>+</SUP> ion (e.g., the <I>k</I><SUB>EtOK</SUB>/<I>k</I><SUB>EtO<SUP>–</SUP></SUB> ratio) decreases linearly as the substituent X in the benzenesulfonyl moiety changes from an electron-donating group (EDG) to an electron-withdrawing group (EWG), but it is independent of the electronic nature of the substituent Y in the leaving group. The reactions have been concluded to proceed through a concerted mechanism from analyses of the kinetic data through linear free energy relationships (e.g., the Brønsted-type, Hammett, and Yukawa–Tsuno plots). K<SUP>+</SUP> ion catalyzes the reactions by increasing the electrophilicity of the reaction center through a cyclic transition state (TS) rather than by increasing the nucleofugality of the leaving group. Activation parameters (e.g., Δ<I>H</I><SUP>‡</SUP> and Δ<I>S</I><SUP>‡</SUP>) determined from the reactions performed at five different temperatures further support the proposed mechanism and TS structures.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/joceah/2013/joceah.2013.78.issue-2/jo302373y/production/images/medium/jo-2012-02373y_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jo302373y'>ACS Electronic Supporting Info</A></P>

Molecular coevolution of kisspeptins and their receptors from fish to mammals : Kisspeptins and their receptors in vertebrates

Um, Haet Nim,Han, Ji Man,Hwang, Jong-Ik,Hong, Sung In,Vaudry, Hubert,Seong, Jae Young Wiley (Blackwell Publishing) 2010 Annals of the New York Academy of Sciences Vol.1200 No.1

<P>Kisspeptin and its receptor, GPR54, play a pivotal role in vertebrate reproduction. Recent advances in bioinformatic tools combined with comparative genomics have led to the identification of a large number of kisspeptin and GPR54 genes in a variety of vertebrate species. Genome duplications may have produced at least two isoforms of both ligand (KiSS1 and KiSS2) and receptor (GPR54-1 and GPR54-2). Additional isoforms of kisspeptin (KiSS1b) and GPR54 (GPR54-1b) have been found in an amphibian species, Xenopus (Silurana) tropicalis. Here, we describe the evolutionary lineages of these kisspeptin and GPR54 isoforms using genome synteny and phylogenetic analyses, and possible molecular interactions between kisspeptin and GPR54 subtypes based on ligand-receptor selectivity. Together, kisspeptin and GPR54 provide an excellent model for understanding molecular coevolution of the peptide ligand and GPCR pairs.</P>

Care/Welfare Technology and Senior Technology Adoption in Super-Aged Society

Young Sun Kim,Tae Hwa Han,Yoon Seok Ko,Jae Gi Son,Su Hyun Shin,Ji Hye Kim,Ji Han Kim,Hye Ri Shin,Sa Rang Um 대한전자공학회 2019 대한전자공학회 학술대회 Vol.2019 No.6

Original Articles : Virologic response is not durable after adefovir discontinuation in Lamivudine-resistant chronic hepatitis B patients

( Young Kul Jung ),( Jong Eun Yeon ),( Kwang Gyun Lee ),( Eun Seok Jung ),( Jeong Han Kim ),( Ji Hoon Kim ),( Yeon Seok Seo ),( Hyung Joon Yim ),( Sun Ho Um ),( Ho Sang Ryu ),( Kwan Soo Byun ) 대한간학회 2011 Clinical and Molecular Hepatology(대한간학회지) Vol.17 No.4

Background/Aims: We investigated the durability of the biochemical and virologic responses after adefovir (ADV) discontinuation in lamivudine-resistant (LMV-R) chronic hepatitis B (CHB) patients, and the outcomes of ADV discontinuation compared to that of ADV maintenance. Methods: The indication for ADV treatment cessation was an undetectable level of hepatitis B virus (HBV) DNA documented on two occasions at least 6 months apart. All patients received additional ADV for at least 12 months after the confirmation of undetectable HBV DNA (Cobas TaqMan PCR assay, <70 copies/mL). Of 36 patients who had a sufficient ADV therapeutic effect, 19 discontinued ADV treatment, while the others maintained it. A virologic rebound was arbitrarily defined as the redetection of HBV DNA at a level higher than 105 copies/mL. Results: In the ADV discontinuation group, ADV treatment and additional therapy were administered for medians of 33 months (range, 12-47 months) and 18 months, respectively. The patients were followed for a median of 12 months (range, 3-30 months) after ADV cessation. During that period, 18 of 19 patients (95%) experienced viral relapse. Viral rebound was observed in six patients (32%). However, 12 of 18 patients (67%) exhibited serum HBV DNA levels of less than 105 copies/mL. Biochemical relapses were observed in four of the six patients with viral rebound. In the ADV maintenance group, patients were treated for a median of 53 months (range, 31-85 months), and 9 patients (53%) experienced viral breakthrough. Conclusions: During short-term follow-up after ADV discontinuation, most patients (95%) exhibited viral relapse, whereas and viral breakthrough occurred in about half of patients (53%) maintained on ADV therapy. Therefore, the durability of virologic response after ADV discontinuation in LMV-R patients was unsatisfactory. In addition, and viral breakthrough was not infrequent in the ADV continuation group. (Korean J Hepatol 2011;17:261-267)

Highly fluorescent and water soluble turn-on type diarylethene for super-resolution bioimaging over a broad pH range

Um, Sang Hoon,Kim, Hyung Jun,Kim, Dojin,Kwon, Ji Eon,Lee, Jong Woo,Hwang, Doyk,Kim, Seong Keun,Park, Soo Young Elsevier 2018 Dyes and pigments Vol.158 No.-

<P><B>Abstract</B></P> <P>We report a water-soluble turn-on type diarylethene SO3-BPDBTEO that reversibly switches its fluorescence on and off upon light stimuli. We note that the two sodium sulfonate groups enable SO3-BPDBTEO to exhibit excellent photo-switching properties in aqueous solution over a wide range of pH between 3 and 10. We demonstrated that SO3-BPDBTEO could be applied to conventional fluorescence imaging of mammalian cell lines such as HeLa cell at various pH conditions with low cytotoxicity. We also examine its feasibility for super-resolution fluorescence imaging as a photoswitching probe.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We report synthesis, characterization, and application of fluorescent diarylethane bearing sodium sulfonate groups. </LI> <LI> It exhibit excellent photo-switching properties in aqueous solution over a wide pH range. </LI> <LI> It can be applied for fluorescence based bioimaging with low cytotoxicity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>