Growth responses of Escherichia coli and Myxococcus xanthus on agar gel substrates with different levels of stiffness

Bacteria colonize surfaces responding to the physicochemical properties of substrates. A systematic study was carried out with growing single bacterial colonies on the surface of agar media to decipher the interaction between bacterial growth and substrate stiffness. We investigated the growth kinetics of wild-type Escherichia coli, non-motile E. coli, and Myxococcus xanthus, cultured on semi-solid agar substrates containing different amounts of nutrient and agar. We found that substrate stiffness, which was controlled by agar concentration, modulates the growth of motile bacteria, such as wild-type E. coli and M. xanthus, independently of the nutrient level, but does not affect the growth response of non-motile E. coli. Interestingly, growth of M. xanthus moving with type IV pili correlates negatively with the substrate stiffness in contrast to wild-type E. coli propelled by flagella. The present study demonstrates that the type of surface motility is a key  determinant of the growth response of bacteria to substrate stiffness, and has potential application to the design of surfaces that prevent or promote biofilm formation.Key words: Bacterial colonization, substrate stiffness, surface motility, swarming, Escherichia coli, Myxococcus xanthus

Removal of Pb and Cu ions from aqueous solution by Mn3O4-coated activated carbon

Mn3O4-coated activated carbon (Mn3O4/AC) was prepared by supercritical technique and applied for the removal of Pb and Cu ions from aqueous solution. Kinetic and isotherm data of the adsorption by Mn3O4/AC were compared with those of activated carbon (AC) and pure Mn3O4. Adsorption of metals was adequately described by pseudo-second-order kinetics and Langmuir isotherm models. Maximum adsorption capacities of Pb and Cu ions determined by Langmuir model were enhanced 2.2 and 6.1 times for Pb and Cu ions by Mn3O4 coating onto AC, which might be attributed to reduced resistance of intraparticle diffusion and enhanced surface electrostatic interaction and complexation by Mn3O4

Origin, criterion, and mechanism of vortex-core reversals in soft magnetic nanodisks under perpendicular bias fields

We studied dynamics of vortex-core reversals driven by circular rotating fields along with static perpendicular magnetic fields of different direction and strength. We found that the application of perpendicular fields H p modifies the starting ground state of vortex magnetizations, thereby instigating the development of a magnetization dip mz,dip in the vicinity of the original core up to its threshold value, m z,dip cri ???-p, which is necessary for vortex-core reversals, where p is the initial core polarization. We found the relationship of the dynamic evolutions of the mz,dip and the out-of-plane gyrofields hz, which was induced, in this case, by vortex-core motion of velocity ??, thereby their critical value relation ??crihz cri. The simulation results indicated that the variation of the critical core velocity ??cri with Hp can be expressed explicitly as ??cri / ?? cri 0 = (??/ ??0) | -p- m z,dip g |, with the core size ?? and the starting ground-state magnetization dip m z,dip g variable with H p, and for the values of ?? cri 0 and ??0 at H p =0. This work offers deeper and/or new insights into the origin, criterion and mechanism of vortex-core reversals under application of static perpendicular bias fields.open7

Hydrated copper and gold monovalent cations: Ab initio study

To understand the hydration phenomena of noble transition metals, we investigated the structures, hydration energies, electronic properties, and spectra of the Cu+(H3O)(1-6) and Au+ (H2O)(1-6) clusters using ab initio calculations. The coordination numbers of these clusters are found to be only two, which is highly contrasted to those of Ag+ (H2O)(n) (which have the coordination numbers of 3-4) as well as the hydrated alkali metal ions (which have the coordination numbers of similar to6). For the possible identification of their interesting hydration structures, we predict their IR spectra for the OH stretch modes. (C) 2005 American Institute of Physics.open384

Sustainability of Korean National Health Insurance

Korean National Health Insurance (NHI) was established during only 12 yr from its inception (1977-1989), providing universal medical coverage to the entire nation and making a huge contribution to medical security. However, the program now faces many challenges in terms of sustainability. The low birth rates, aging population, low economic growth, and escalating demands for welfare, as well as unification issues, all add pressure to the sustainability of NHI. The old paradigm of low contribution - low benefits coverage - low NHI's fee schedule needs to be replaced by a new paradigm of proper contribution - adequate benefit coverage - fair NHI's fee schedule. This new paradigm will require reform of NHI's operating system, funding, and spending

Genetic analysis of env and gag gene fragments of bovine leukemia virus identified in cattle from Korea

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the molecular characteristics of BLVs obtained from a specific region in Korea. Proviral BLVs were detected in anti-BLV antibody-positive blood samples by PCR. Env and gag fragments were sequenced and compared to previously published reference sequences. Analysis of the env gene sequence revealed that the YI strain was highly similar to genotype 1, including United States and Japanese strains. The gag gene sequence had the highest degree of similarity with a Japanese strain.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/0000030777/4ADJUST_YN:YEMP_ID:A076079DEPT_CD:551CITE_RATE:0FILENAME:53-56.pdfDEPT_NM:수의학과CONFIRM:

Evaluation of 28 Human Embryonic Stem Cell Lines for Use as Unrelated Donors in Stem Cell Therapy: Implications of HLA and ABO Genotypes

For human embryonic stem cells (hESCs) to be used clinically, it is imperative that immune responses evoked by hESCs and their derivates after transplantation should be prevented. Human leukocyte antigens (HLA) and ABO blood group antigens are important histocompatibility factors in graft rejection. HLA matching between recipient and unrelated donors, in particular, is important in improving outcomes in hematopoietic cell transplantation (HCT). We have established and successfully maintained 29 hESC lines and analyzed the HLA and ABO genotypes of these lines. HLA-A, -B, -C and -DR (DRB1) genotyping was performed by polymerase chain reaction (PCR) sequence-based typing and ABO genotyping was carried out by PCR restriction fragment length polymorphism methods. To determine what proportion of the Korean population would be covered by these cell lines in organ transplantation, 27 cell lines with HLA-A, -B, and -DR data were evaluated for HCT (cord blood) donors and 28 cell lines with HLA-DR and ABO data were evaluated for solid organ (kidney) transplantation donors, and then compared the data with those from 6,740 donated cord bloods. When <= 2 HLA mismatches are allowed for HCT, as currently accepted for cord blood transplantation, it was estimated that about 16% and 25% of the possible recipients can find one or more donor cell lines with mismatches at A, B, DRB1 allele level and at A, B antigen/DRB1 allele level, respectively. When HLA-DR antigen level matching and ABO compatibility was considered for solid organ (kidney) transplantation, it was estimated that about 29% and 96% of the possible recipients can find one or more ABO-compatible donor cell lines with 0 and 1 DR mismatches, respectively. We provided the first report on the HLA and ABO genotypes of hESC lines, and estimated the degree of HLA and ABO matching in organ transplantation for the Korean population.Yu JY, 2009, SCIENCE, V324, P797, DOI 10.1126/science.1172482Kaji K, 2009, NATURE, V458, P771, DOI 10.1038/nature07864Lee JY, 2010, FERTIL STERIL, V93, P976, DOI 10.1016/j.fertnstert.2008.10.017Holdsworth R, 2009, TISSUE ANTIGENS, V73, P95, DOI 10.1111/j.1399-0039.2008.01183.xLehec SC, 2009, CELL TRANSPLANT, V18, P941, DOI 10.3727/096368909X471323Oishi K, 2009, CELL TRANSPLANT, V18, P581Molne J, 2008, TRANSPLANTATION, V86, P1407, DOI 10.1097/TP.0b013e31818a6805Fernandes AM, 2010, CELL TRANSPLANT, V19, P509, DOI 10.3727/096368909X485067Stadtfeld M, 2008, SCIENCE, V322, P945, DOI 10.1126/science.1162494Wang GW, 2005, BIOCHEM BIOPH RES CO, V330, P934, DOI 10.1016/j.bbrc.2005.03.058Hoffman LM, 2005, NAT BIOTECHNOL, V23, P699, DOI 10.1038/nbt1102Li Y, 2005, BIOTECHNOL BIOENG, V91, P688, DOI 10.1002/bit.20536Vallier L, 2005, J CELL SCI, V118, P4495, DOI 10.1242/jcs.02553Taylor CJ, 2005, LANCET, V366, P2019Boyd AS, 2005, ADV DRUG DELIVER REV, V57, P1944, DOI 10.1016/j.addr.2005.08.004Ludwig TE, 2006, NAT BIOTECHNOL, V24, P185, DOI 10.1038/nbt1177Drukker M, 2006, STEM CELLS, V24, P221, DOI 10.1634/stemcells.2005-0188Priddle H, 2006, STEM CELLS, V24, P815, DOI 10.1634/stemcells.2005-0356Reubinoff BE, 2000, NAT BIOTECHNOL, V18, P399Amit M, 2000, DEV BIOL, V227, P271Xu CH, 2001, NAT BIOTECHNOL, V19, P971Drukker M, 2002, P NATL ACAD SCI USA, V99, P9864, DOI 10.1073/pnas.142298299Richards M, 2002, NAT BIOTECHNOL, V20, P933, DOI 10.1038/nbt726Bradley JA, 2002, NAT REV IMMUNOL, V2, P859, DOI 10.1038/nri934Amit M, 2003, BIOL REPROD, V68, P2150, DOI 10.1095/biolreprod.102.012583Li L, 2004, STEM CELLS, V22, P448Drukker M, 2004, TRENDS BIOTECHNOL, V22, P136, DOI 10.1016/j.tibtech.2004.01.003Thomson JA, 1998, SCIENCE, V282, P1145Petersdorf EW, 1999, CURR OPIN IMMUNOL, V11, P521Bodnar MS, 2004, STEM CELLS DEV, V13, P243Koivisto H, 2004, REPROD BIOMED ONLINE, V9, P330Rocha V, 2004, NEW ENGL J MED, V351, P2276Laughlin MJ, 2004, NEW ENGL J MED, V351, P2265Lee JB, 2005, BIOL REPROD, V72, P42, DOI 10.1095/biolrepod.104.033480Xu RH, 2005, NAT METHODS, V2, P185, DOI 10.1038/NMETH744Beattie GM, 2005, STEM CELLS, V23, P489, DOI 10.1634/stemcells.2004-0279Genbacev O, 2005, FERTIL STERIL, V83, P1517, DOI 10.1016/j.fertnstert.2005.01.086Oh SKW, 2006, CLIN EXP PHARMACOL P, V33, P489Skottman H, 2006, FEBS LETT, V580, P2875, DOI 10.1016/j.febslet.2006.03.083Xiao L, 2006, STEM CELLS, V24, P1476, DOI 10.1634/stemcells.2005-0299Stussi G, 2006, TRANSFUS APHER SCI, V35, P59, DOI 10.1016/j.transci.2006.05.009Takahashi K, 2006, CELL, V126, P663Guhr A, 2006, STEM CELLS, V24, P2187, DOI 10.1634/stemcells.2006-0053Klumpp TR, 2006, BONE MARROW TRANSPL, V38, P615, DOI 10.1038/sj.bmt.1705496Nakajima F, 2007, STEM CELLS, V25, P983, DOI 10.1634/stemcells.2006-0566Huangfu DW, 2008, NAT BIOTECHNOL, V26, P1269, DOI 10.1038/nbt.1502Petersdorf EW, 2008, CURR OPIN IMMUNOL, V20, P588, DOI 10.1016/j.coi.2008.06.014Chen YT, 2008, STEM CELLS DEV, V17, P853, DOI 10.1089/scd.2007.0226Park IH, 2008, CELL, V134, P877, DOI 10.1016/j.cell.2008.07.041Swijnenburg RJ, 2008, P NATL ACAD SCI USA, V105, P12991, DOI 10.1073/pnas.0805802105Unger C, 2008, HUM MOL GENET, V17, pR48, DOI 10.1093/hmg/ddn079Drukker M, 2008, SEMIN IMMUNOL, V20, P123, DOI 10.1016/j.smim.2007.11.002Revazova ES, 2008, CLONING STEM CELLS, V10, P11, DOI 10.1089/clo.2007.0063Mountford JC, 2008, TRANSFUSION MED, V18, P1, DOI 10.1111/j.1365-3148.2007.00807.xPark IH, 2008, NATURE, V451, P141, DOI 10.1038/nature06534Nakagawa M, 2008, NAT BIOTECHNOL, V26, P101, DOI 10.1038/nbt1374Buzzeo MP, 2008, CELL TRANSPLANT, V17, P489Kamani N, 2008, BIOL BLOOD MARROW TR, V14, P1, DOI 10.1016/j.bbmt.2007.11.003Saric T, 2008, CELLS TISSUES ORGANS, V188, P78, DOI 10.1159/000118784Navarro-Alvarez N, 2008, CELL TRANSPLANT, V17, P27KASTENBERG ZJ, 2008, TRANSPLANT REV ORLAN, V22, P215Lee SJ, 2007, BLOOD, V110, P4576, DOI 10.1182/blood-2007-06-097386Shaw BE, 2007, BLOOD, V110, P4560, DOI 10.1182/blood-2007-06-095265Strom S, 2007, HUM REPROD, V22, P3051, DOI 10.1093/humep/dem35Lin G, 2007, CELL RES, V17, P999, DOI 10.1038/cr.2007.97Crook JM, 2007, CELL STEM CELL, V1, P490Helming AM, 2007, PEDIATR BLOOD CANCER, V49, P313, DOI 10.1002/pbc.21025Cabrera CM, 2007, CELL BIOL INT, V31, P1072, DOI 10.1016/j.cellbi.2007.03.015Lei T, 2007, CELL RES, V17, P682, DOI 10.1038/cr.2007.61Okita K, 2007, NATURE, V448, P313, DOI 10.1038/nature05934Wernig M, 2007, NATURE, V448, P318, DOI 10.1038/nature05944Maherali N, 2007, CELL STEM CELL, V1, P55, DOI 10.1016/j.stem.2007.05.014Eapen M, 2007, LANCET, V369, P1947

Epidemiological and Clinical Parameters Features of Patients with Clonorchiasis in the Geum River Basin, Republic of Korea

This study was conducted to evaluate the infection rates of Clonorchis sinensis and laboratory findings in infected people. The 3,167 fecal samples, from nine villages in Okcheon-gun, were examined