Interaction of silver(I) and copper(I) with an O₂S₂-macrocycle - A comparative structural study

Kim, S.,Lee, E.,Lee, S.Y.,Lee, S.S.,Lindoy, L.F. Elsevier Sequoia [etc.] 2014 Inorganica chimica acta Vol.417 No.-

The 14-membered O<SUB>2</SUB>S<SUB>2</SUB>-macrocycle L reacts with AgPF<SUB>6</SUB> in acetonitrile/dichloromethane (1:1) to yield the cyclic, double S-Ag-S bridged complex, [Ag<SUB>2</SUB>L<SUB>2</SUB>(CH<SUB>3</SUB>CN)<SUB>4</SUB>](PF<SUB>6</SUB>)<SUB>2</SUB> (2), in which each Ag(I) is bound to two exo-oriented S donors arising from different macrocycles to form a 12-membered, di-Ag metallacycle. Two PF<SUB>6</SUB><SUP>-</SUP> ions form weak intramolecular contacts [Ag...F, 2.925(2)A] between the Ag centres in a bridging bidentate fashion. The coordination sphere of each Ag is completed by two weakly bound acetonitrile molecules. The respective macrocyclic ligands are arranged trans to the mean plane through the metallacycle. When the above synthetic procedure was repeated employing methanol/dichloromethane (1:1) as solvent, a complex of type [Ag<SUB>2</SUB>L<SUB>2</SUB>](PF<SUB>6</SUB>)<SUB>2</SUB> (3) was obtained whose structure incorporates a similar 12-membered metallacycle but with the respective macrocyclic rings now oriented towards the same side of the metallacyclic plane. The reaction of L with AgCF<SUB>3</SUB>SO<SUB>3</SUB> yields [Ag<SUB>2</SUB>L<SUB>2</SUB>(CF<SUB>3</SUB>SO<SUB>3</SUB>)<SUB>2</SUB>].2CH<SUB>3</SUB>CN (4) whose structure resembles that of [Ag<SUB>2</SUB>L<SUB>2</SUB>(CH<SUB>3</SUB>CN)<SUB>4</SUB>](PF<SUB>6</SUB>)<SUB>2</SUB> (2); each complex unit incorporates a di-Ag(I) 12-membered metallacycle, with symmetrical bridging bidentate CF<SUB>3</SUB>SO<SUB>3</SUB><SUP>-</SUP> ions weakly linking Ag centres. Long Ag1...Ag1C contacts are present between pairs of complex units. Reaction of Cu(CH<SUB>3</SUB>CN)<SUB>4</SUB>PF<SUB>6</SUB> (one equiv.) with L in methanol/dichloromethane (1:1) resulted in isolation of [CuL<SUB>2</SUB>]PF<SUB>6</SUB> (5) incorporating a distorted tetrahedral S<SUB>4</SUB>-coordination sphere, with each macrocycle binding as a bidentate ligand via its two (exo-orientated) S atoms. In contrast, reaction of [Cu(CH<SUB>3</SUB>CN)<SUB>4</SUB>]PF<SUB>6</SUB> (two equiv.) with L in either acetonitrile/dichloromethane (1:1) or methanol/dichloromethane (1:1) yielded [Cu<SUB>2</SUB>L<SUB>3</SUB>]PF<SUB>6</SUB> (6) in which the Cu(I) centres are bound exo to the macrocyclic cavity by individual S-donors from one L, with the coordination sphere of each Cu(I) completed by out-of-plane binding of the S<SUB>2</SUB>O donors from a second L. Unsymmetrical F...Cu contacts from a PF<SUB>6</SUB><SUP>-</SUP> anion weakly link the pair of Cu centres in a bridging bidentate fashion.

Interaction of copper(II) with N-substituted bis(2-pyridylmethyl)amine derivatives

Kim, M.,Mora, C.,Lee, Y.H.,Clegg, J.K.,Lindoy, L.F.,Min, K.S.,Thuery, P.,Kim, Y. Elsevier 2010 Inorganic chemistry communications Vol.13 No.10

<P>Interaction of copper(II) with the N-substituted bis(2-pyridylmethyl)amine derivatives, (R)-N-1,N-1-bis (pyridine-2-ylmethyl)butane-1,2-diamine (L-1) and (R)-2-(bis(pyridin-2-ylmethyl)amino)butan-1-ol (L-2), has led to isolation of optically active [Cu(L-1)Cl]PF6 (1) and [Cu(L-2)Cl]ClO4 (2), respectively. The X-ray structures of (1) and (2) show that the copper is bound to all four heteroatoms of the respective ligands as well as to a chlorine atom in a distorted square pyramidal arrangement in which the three nitrogens of L-1 or L-2 occupy three positions of each basal plane while the fourth position is occupied by the chloro ligand; apical sites in each case are filled by the amine donor from the NH2-substituted butane arm in L-1 or the (protonated) alcohol oxygen of the 2-aminobutane-1-ol substituent in L-2. To a first approximation the coordination geometry in 2 is distorted square pyramidal; however, the remaining (axial) site on each copper centre is involved in a long contact (2.96 angstrom) with a bound chloro ligand from an adjacent complex which connects individual complex units in a zigzag 1-D polymeric chain, so that the coordination geometry could also be seen as pseudo-octahedral. A temperature-dependent magnetic study revealed the presence of ferromagnetic exchange coupling between copper centres in the chain reflecting the orthogonal structure between the chloro-bridged copper(II) ions; in contrast, and as expected, the discrete complex 1 is magnetically dilute. (C) 2010 Elsevier B.V. All rights reserved.</P>

노인의 병원 선택 경험

김단비,김민지,김해솔,김희정,박윤선,손유경,송예진,유예림,이다예,이서영,이지현,강숙정,김부연 이화여자대학교간호학회 2020 이화간호학회지 Vol.- No.54

Purpose: The purpose of this descriptive study was to examine hospital choice factors among elderly patients to understand their experience and use as data to move towards senior-friendly hospitals. Methods: The individual in-depth interviews were conducted from August 13th to 18th, 2019. The participants consisted of eight senior citizens aged 65 and above that suffered from chronic illnesses and had regular hospital visits. Results: This study found that when elderly patients choose the hospital, they considered ‘awareness such as brand name of the hospital', ‘quality of medical service',‘convenience', ‘healthcare team / hospital employee', ‘personal experience', ‘children’s recommendation’ and etc,. The significant point was that all these factors were related to personal experiences from specific hospitals. Conclusion: This study analyzed the hospital choice factors of the elderly patients with high hospital utilization rates and found that the results were mainly affected by the distinct characteristics of elderly patients. The implications of this study are that we proposed further research directions and means for the improvement of the hospital. We suggest hospitals to increase labor allocation for elderly patients with difficulties dealing with unmanned systems such as kiosk and strengthen the role of healthcare providers as instructors for higher satisfaction.

Fabrication and microstructure of hot pressed laminated Y₂O₃/Nd:Y₂O₃/Y₂O₃ transparent ceramics

Gan, L.,Park, Y.J.,Kim, H.,Kim, J.M.,Ko, J.W.,Lee, J.W. Elsevier Science Publishers 2016 Journal of the European Ceramic Society Vol.36 No.3

A transparent three-layered composite Y<SUB>2</SUB>O<SUB>3</SUB>/1at% Nd:Y<SUB>2</SUB>O<SUB>3</SUB>/Y<SUB>2</SUB>O<SUB>3</SUB> ceramic was successfully fabricated by a hot-pressing method. After the hot-pressing step, the laminar structure was maintained very well, and no apparent deformation was found. The sample shows a fine microstructure (the average grain size is ~1μm) without an apparent transition layer between a Nd-doped layer and an undoped layer as a result of the relatively low hot-pressing temperature of only 1600<SUP>o</SUP>C. For a 4-mm-thick polished specimen, the in-line transmittance reaches 59.7% at 400nm and 73.0% at 1100nm.

Characterization of Lactobacillus acidophilus Isolated from Piglets and Chicken

Ahn, Y.T.,Lim, K.L.,Ryu, J.C.,Kang, D.K.,Ham, J.S.,Jang, Y.H.,Kim, H.U. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.12

Lactic acid bacteria were isolated from piglets and chicken and characterized. Lactic acid bacteria showing resistance to low pH and bile, adhesion to intestinal epithelium cells, and the inhibition of Escherichia coli and Salmonella spp. were identified as Lactobacillus acidophilus. L. acidophilus PF01 survived for 2 h in MRS broth adjusted to pH 2. L. acidophilus CF07 was less resistant than L. acidophilus PF01 to pH 2, but survived at pH 2.5 for 2 h. Both of isolates were able to grow in MRS broth containing 0.3% (w/v) bile, with L. acidophilus CF07 being more tolerant to bile than L. acidophilus PF01. L. acidophilus PF01 and CF07 adhered specifically to the duodenal and jejunal epithelium cells of piglet, and the cecal and duodenal epithelium cells of chicken, respectively. Both of isolates did not adhere to the epithelium cells of the various animal intestines from which they were isolated. When L. acidophilus was cultured with E. coli and Salmonella spp. in MRS broth, MRS broth containing 2% skim milk powder or modified tryptic soy broth at $37^{\circ}C$, L. acidophilus PF01 and CF07 inhibited the growths of E. coli K88 and K99, and S. enteritidis and S. typhimurium, respectively. Both of isolates were found to possess the essential characteristics of probiotic lactic acid bacteria for piglet and chicken.

Effects of the Zr concentration on transparent Y2O3 ceramics fabricated by vacuum pre-sintering and a subsequent HIP treatment

Zhu, L. L.,Park, Y. J.,Gan, L.,Go, S. I.,Kim, H. N.,Kim, J. M.,Ko, J. W. Chapman and Hall 2017 Journal of materials science Materials in electron Vol. No.

<P>Highly transparent Y2O3 ceramics doped with different Zr concentrations were successfully fabricated by vacuum pre-sintering at temperatures ranging from 1600 to 1800 degrees C combined with a subsequent hot-isostatic pressing (HIP) treatment using commercial powders as the starting materials. All of the 1 mol% Zr-doped Y2O3 ceramics exhibit very good optical quality. The sample with the highest transparency level was realized by vacuum sintering at 1650 degrees C for 4 h followed by a post-HIP treatment at 1450 degrees C lasting 5 h. It has a fine microstructure and the grain size is 1.48 mu m. Furthermore, the in-line transmittance reaches 83.3% at 1100 nm (1.2 mm thickness). It was found that a relatively low vacuum sintering temperature (1650 degrees C) and relatively low Zr doping concentration (1 mol%) are more appropriate to achieve optimally transparent Y2O3 ceramics with a subsequent HIP treatment.</P>

Elimination of the cryptic plasmid in Leuconostoc citreum by CRISPR/Cas9 system

Jang, Y.J.,Seo, S.O.,Kim, S.A.,Li, L.,Kim, T.J.,Kim, S.C.,Jin, Y.S.,Han, N.S. Elsevier Science Publishers 2017 Journal of biotechnology Vol.251 No.-

<P>Leuconostoc spp. are important lactic acid bacteria for the fermentation of foods. In particular, L. citreum strains isolated from various foods have been used as host strains for genetic and metabolic engineering studies. In order to develop a food-grade genetic engineering system, L. citreum CB2567 was isolated from Kimchi. However, the isolated bacterium contained a cryptic plasmid which was difficult to eliminate. As the existence of the plasmid might hinder strain engineering, we eliminated the plasmid using an RNA-guided DNA endonuclease CRISPR/Cas9 system. We demonstrated that a plasmid-free L. citreum CB2567 host strain could be efficiently constructed through a two-step procedure: 1) transformation of the 'killer' plasmid expressing Cas9 endonuclease and a guide RNA (gRNA) targeting for a specific sequence in the cryptic plasmid, and 2) serial subculture without antibiotics for curing the killer plasmid. When the crude extract of L. citreum expressing Cas9 and the guide RNA was incubated with a PCR fragment containing the specific sequence recognized by the guide RNA, the PCR fragment was cleaved. Also, the cryptic plasmid pCB42 was successfully eliminated from the host strain after transforming the plasmid harboring Cas9 and the guide RNA. The Cas9 and gRNA expression plasmid used in this study can be applied for genome engineering purposes by additionally introducing an editing DNA template to repair the double strand DNA breakage caused by Cas9 in the genome of L. citreum. This study demonstrates the feasibility of developing CRISPR/Cas9-based genetic engineering tools to develop a safe host strain and construct food-grade lactic acid bacteria without residual antibiotic markers.</P>

Reduction of d-lactate content in sauerkraut using starter cultures of recombinant Leuconostoc mesenteroides expressing the ldhL gene

Jin, Q.,Li, L.,Moon, J.S.,Cho, S.K.,Kim, Y.J.,Lee, S.J.,Han, N.S. Society for Bioscience and Bioengineering, Japan ; 2016 Journal of bioscience and bioengineering Vol.121 No.5

<P>The n-form of lactate, which causes metabolic stress upon excessive dietary intake, is mainly produced by Leuconostoc sp., the predominant species in sauerkraut. To shift the metabolic flux of D-lactate from pyruvate to L-lactate, we expressed the L-lactate dehydrogenase (ldhL) gene in Leuconostoc mesenteroides ATCC 8293. The IdhL gene from Lactobacillus plantarum was introduced into L. mesenteroides using the shuttle vectors pLeuCM and pLeuCM42. To elevate the expression level of IdhL in L. mesenteroides, the nucleotides for pyruvate kinase promoter were fused to IdhL and cloned into above vectors to construct pLC18pkL and pLC42pkL. As results, introduction of pLC42pkL in L. mesenteroides significantly improved both L-LDH activity and L-lactate productivity during fermentation, decreasing the D-/L-lactate ratio. When used as a starter culture for sauerkraut fermentation, recombinant L. mesenteroides harboring pLC42pkL increased L-lactate concentration and decreased D-lactate concentration compared to the wild type strain. We newly developed a recombinant L. mesenteroides which has high L-lactate dehydrogenase activity and applied this strain to minimize the harmful effect of D-lactate during the sauerkraut fermentation. To the best of our knowledge, we demonstrate for the first time the effective use of recombinant Leuconostoc sp. for quality improvement of fermented foods. (C) 2015, The Society for Biotechnology, Japan. All rights reserved.</P>

Effect of dietary lactulose supplementation on growth performance, nutrient digestibility, meat quality, relative organ weight, and excreta microflora in broilers

Zhao, P.Y.,Li, H.L.,Mohammadi, M.,Kim, I.H. Elsevier 2016 Poultry science Vol.95 No.1

<P>A 35 d trial was conducted to evaluate the effects of dietary lactulose on growth performance, nutrient digestibility, meat quality, relative organ weight, and excreta microflora in broilers. A total of 816 1-day-old male Ross broilers (40.2 +/- 0.4 g) were allotted to 4 dietary treatments using 12 cages with 17 chicks per cage. Treatments were: 1) CON, basal diet; 2) L05, CON + 0.05% lactulose; 3) L10, CON + 0.10% lactulose; and 4) L15, CON + 0.15% lactulose. Higher (P < 0.05) body weight gain (BWG) and lower (P < 0.05) feed conversion ratio (FCR) were observed in broilers fed the L15 diet compared with those fed the CON diet during d 22 to 35. During d 0 to 35, BWG was higher (P < 0.05) and FCR was lower (P < 0.05) in broilers fed lactulose diets than those fed the CON diet. Additionally, broilers fed L15 diets had the highest BWG (P < 0.05) and lowest FCR (P < 0.05). The apparent total tract digestibility (ATTD) of DM and nitrogen (N) was increased (P < 0.05) in broilers fed the L15 diet compared with those fed the CON diet. Drip loss was decreased (P < 0.05) in L10 and L15 treatments compared with CON treatment on d 1, d 3, and d 5. On d 3, lowest (P < 0.05) drip loss was observed in the L15 treatment. Excreta E. coli counts in the L15 treatment were decreased (P < 0.05) on d 14, but Lactobacillus counts in the L15 treatment were increased (P < 0.05) on d 14 and d 35 compared with the CON diet. A linear effect (P < 0.05) was observed on BWG (d 22 to 35), FCR (d 0 to 35), the ATTD of DM and N, drip loss, E. coli (d 14), and Lactobacillus (d 14 and d 35) counts. In conclusion, dietary supplementation of 0.15% lactulose can improve growth performance and nutrient digestibility; as well as increase the proliferation of Lactobacillus and decrease E. coli counts in excreta.</P>

Expression analysis of UV-B signaling genes in soybean [Glycine max (L.) Merr.].

Yoon, M.Y.,Shim, S.R.,Kim, M.Y,Kim, K.D,Lee, Y.H,Lee, S.H 한국육종학회 2014 한국육종학회 심포지엄 Vol.2014 No.07

Due to depletion of the stratospheric ozone layer throughout most of this century, increased UV-B radiation has affected seriously to plant growth and development as one of nature mutagens. We surveyed differential expressed genes (DEGs) under UV-B irradiation in UV-B tolerant Buseok compared to UV-B sensitive Cheongja 3 through RNA seq analysis using six RNA samples of Buseok and Cheongja 3 with 0.5 hr and 6 hr UV-B irradiation or without irradiation. After excluding 1003 DEGs due to genetic background difference of two genotypes, a total of 872 DEGs orthologous to UV-related Arabidopsis genes were identified. BINGO analysis of the DEGs by 0.5 hr UV-B irradiation showed overrepresentation in signaling and cell morphogenesis. Genes related with apoptosis and immune response were overrepresented in 6 hr irradiated Buseok. In addition, KEGG pathway database was used to identify mTOR signaling and phosphatidylinositol signaling pathways. Based on GO and KEGG results, specific focus was given to a serial of genes involved in UV-B defense signaling, besides photomorphogenesis and oxidation reduction-related genes. Several genes playing a role in phosphatidylinositol signaling, such as diacylglycerol kinase, phosphatidylinositol-4-phosphate 5-kinase family protein, were highly expressed in UV-B tolerant Buseok by 0.5 hr irradiation. Mitogen-activated protein kinase (MAPK) 19 and 20 were highly expressed in Buseok under 6 hr irradiation. Furthermore, 51 nucleotide binding site leucine rich repeats (NBS-LRRs) genes were up-regulated in Buseok under 0.5 hr irradiation.