8,057 research outputs found

    Nanotopographic Cell Culture Substrate: Polymer-Demixed Nanotextured Films Under Cell Culture Conditions

    Get PDF
    Modulating physical cell culture environments via nanoscale substrate topographic modification has recently been of significant interest in regenerative medicine. Many studies have utilized a polymer-demixing technique to produce nanotextured films and showed that cellular adhesion, proliferation, and differentiation could be regulated by the shape and scale of the polymer-demixed nanotopographies. However, little attention has been paid to the topographic fidelity of the polymer-demixed films when exposed to cell culture conditions. In this brief article, two polymer-demixing systems were employed to assess topographic changes in polymer-demixed films after fibronectin (FN) extracellular matrix protein adsorption and after incubation in phosphate-buffered saline at 37ā—¦C. We showed that FN adsorption induced very small variations ( \u3c 2 nm) to the polystyrene/polybromostyrene (PS/PBrS)-demixed nanoisland textures, not substantially altering the nanotopographies given by the polymer demixing. In addition, poly(L-lactic acid)/PS (PLLA/PS)-demixed nanoisland topographies using PLLA with Mw = 50 x 103 did not show notable degradation up to day 24

    Forest Decline Under Progress in the Urban Forest of Seoul, Central Korea

    Get PDF
    Vegetation in the urban area showed not only a difference in species composition but also lower diversity compared with that of the natural area. Successional trend was normal in natural area, but that in urban areas showed a retrogressive pattern. Korean mountain ash (Sorbus alnifolia (Siebold & Zucc.) K.Koch), a shade intolerant species, dominated such a retrogressive succession. The vegetation decline is due to changes of mesoclimate and soil properties that imbalanced distribution of green space induced as the result of urbanization. In recent years, new environmental stress due to climate change is imposed additively to this forest decline. Drought is the very environmental stress. Drought-induced plant damage started from withering of leaves of plants introduced for landscaping in the urban area. Over time, branches died and death of the whole plant body followed. In particular, damage of Korean mountain ash, the product of retrogressive succession, was remarkable. As retrogressive succession has already progressed much, thus such phenomenon could be recognized as crisis of urban forest

    Nickel(II) and Cobalt(II) Nitrate and Chloride Networks with 2-aminopyrimidine

    Get PDF
    The coordination chemistry of 2-aminopyrimidine (PymNH2) with nickel(II) and cobalt(II) nitrate and chloride is reported, including seven new X-ray crystal structures. Two [Ni(NO3)2(PymNH2)2(OH2)] isomers were found (A: C2/c, a=13.3006(5), b=7.9727(3), c=28.5453(11), Ī²=101.758(2), V=2963.48(19), Z=8 and BĀ·1/2 acetone: P21/c, a=7.66060(10), b=10.6792(2), c=20.6790(3), Ī²=100.2970(10), 1664.48(5), Z=4). In both cases one nitrate is monodentate and the other is chelating and the PymNH2 ligands coordinate through ring nitrogen atoms. Hydrogen bonding results in double sheet structure for isomer A, and a three dimensional channeled network for isomer B. [Co(NO3)2(PymNH2)2(OH2)] (C2/c, a=13.3507(2), b=7.99520(10), c=28.6734(3), Ī²=102.3540(10), V=2989.77(7), Z=8) is isostructural to Ni isomer A. [CoCl2(PymNH2)] (Cmcm, a=3.6139(2), b=14.3170(7), c=12.9986(7), V=672.55(6), Z=4) is a sheet coordination network, consisting of corner-sharing chains of Co2(Ī¼-Cl)2 bridged by PymNH2 through ring nitrogen atoms; [CoCl2(PymNH2)2] (C2/c, a=11.2774(6), b=6.5947(4), c=16.5687(9), Ī²=92.269(3), V=1231.27(12), Z=4) is a tetrahedral molecule knit into a ribbon structures through pairs of hydrogen bonds. Isostructural trans-[NiCl2(PymNH2)4] (C2/c, a=7.67760(10), b=18.7224(3), c=15.0418(2), Ī²=99.6740(10), V=2131.41(5), Z=4) and trans-[CoCl2(PymNH2)4] (C2/c, a=7.69120(10), b=18.5957(2), c=15.1091(2), Ī²=99.5280(10), V=2131.14(5), Z=4) are simple octahedral molecules, with hydrogen-bonding producing sheet structures

    L-Asparaginase delivered by Salmonella typhimurium suppresses solid tumors

    Get PDF
    Bacteria can be engineered to deliver anticancer proteins to tumors via a controlled expression system that maximizes the concentration of the therapeutic agent in the tumor. L-asparaginase (L-ASNase), which primarily converts asparagine to aspartate, is an anticancer protein used to treat acute lymphoblastic leukemia. In this study, Salmonellae were engineered to express L-ASNase selectively within tumor tissues using the inducible araBAD promoter system of Escherichia coli. Antitumor efficacy of the engineered bacteria was demonstrated in vivo in solid malignancies. This result demonstrates the merit of bacteria as cancer drug delivery vehicles to administer cancer-starving proteins such as L-ASNase to be effective selectively within the microenvironment of cancer tissue

    Esophageal Thermal Injury by Hot Adlay Tea

    Get PDF
    Reversible thermal injury to the esophagus as the result of drinking hot liquids has been reported to generate alternating white and red linear mucosal bands, somewhat reminiscent of a candy cane. This phenomenon is associated with chest pain, dysphagia, odynophagia, and epigastric pain

    Antibiotic-induced Severe Neutropenia with Multidrug-Dependent Antineutrophil Antibodies Developed in A Child with Streptococcus pneumoniae Infection

    Get PDF
    Drug-induced neutropenia (DIN), particularly that in which antibiotic-dependent antineutrophil antibodies have been detected, is a rare disorder. We report the case of a child with pneumococcal pneumonia, who experienced severe neutropenia during various antibiotic treatments. We detected 4 kinds (cefotaxim, augmentin, vancomycin, and tobramycin) of antibiotic-dependent antineutrophil antibodies by using the mixed passive hemagglutination assay (MPHA) technique with this child
    • ā€¦
    corecore