Dynamic chemotactic response of fibroblasts to local stimulation using EGF-immobilized microbeads.
Aratsu F1, Harada I2, Yoshimura S1, Cho CS3, Akaike T1, Tagawa Y1.Author information 1Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J3-162, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.2Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J3-162, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. Electronic address: iharada@bio.titech.ac.jp.3Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, 151-921, Republic of Korea.AbstractDirectional cellular migrations as a chemotactic response to spatially inhomogeneous growth factor stimulation play an important role in establishing physiological mechanisms and pathological events in cells. We developed epidermal growth factor (EGF)-immobilized microbeads by photoreaction and evaluated its local stimulatory effects on the dynamic chemotactic motility of fibroblasts. The local stimulation resulted in global activation of ERK 1/2 and directionality of cellular migration. The cellular migration by stimulation using 3-μm diameter EGF-immobilized microbeads persisted for a longer time, were involved a wider field and their number were further increased with stimulation. This effective technique allows cellular migration and biochemical analyses that will help elucidate the mechanisms involved in signal transduction by spatially inhomogeneous stimulation of the growth factor.
Biomaterials.Biomaterials.2014 Mar;35(8):2471-6. doi: 10.1016/j.biomaterials.2013.12.013. Epub 2013 Dec 24.
Directional cellular migrations as a chemotactic response to spatially inhomogeneous growth factor stimulation play an important role in establishing physiological mechanisms and pathological events in cells. We developed epidermal growth factor (EGF)-immobilized microbeads by photoreaction and eval
Photodegradation of sulfapyridine under simulated sunlight irradiation: Kinetics, mechanism and toxicity evolvement.
Xu J1, Hao Z2, Guo C1, Zhang Y3, He Y1, Meng W1.Author information 1State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.2State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.3State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: zhangyuan@craes.org.cn.AbstractIn this study, the photoinduced degradation of sulfapyridine (SPY) was investigated under simulated light irradiation (λ>200nm). The effect of pH and main water constituents including nitrate ion, bicarbonate, dissolved organic matter (DOM) and iron(III) on the photodegradation was explored. SPY was effectively removed in aqueous solution at pH 8 under UV-vis irradiation, with removal efficiency of 100% within 120min. DOM and iron(III) had retarding influence on the SPY removal, whereas nitrate ion and bicarbonate did not show any obvious effect. Under UV-vis irradiation, the formation of singlet oxygen ((1)O2) accelerated the SPY photodegradation and the contribution of indirect photolysis due to reaction with (1)O2 was up to 42%. The transformation products of SPY were identified by HPLC-MS and the possible photoreaction pathways were proposed. It showed that photoinduced hydrolysis, photo-oxidation via (1)O2 and desulfonation were the main degradation ways for SPY decomposition. Toxicity assays by Vibrio fischeri proved that the transformation products were more toxic than the parent compound.
Chemosphere.Chemosphere.2014 Mar;99:186-91. doi: 10.1016/j.chemosphere.2013.10.069. Epub 2013 Nov 27.
In this study, the photoinduced degradation of sulfapyridine (SPY) was investigated under simulated light irradiation (λ>200nm). The effect of pH and main water constituents including nitrate ion, bicarbonate, dissolved organic matter (DOM) and iron(III) on the photodegradation was explored. SPY
Photoinduced Dimerization Reaction Coupled with Oxygenation of a Platinum(II)-Hydrazone Complex.
Kobayashi A, Yamamoto D, Horiki H, Sawaguchi K, Matsumoto T, Nakajima K, Chang HC, Kato M.Author information Department of Chemistry, Faculty of Science, Hokkaido University , North-10 West-8, Kita-ku, Sapporo 060-0810, Japan.AbstractPhotoreactivities of Ni(II)- and Pt(II)-hydrazone complexes, [NiCl(L)] (Ni1) and [PtCl(L)] (Pt1), respectively [HL = 2-(diphenylphosphino)benzaldehyde-2-pyridylhydrazone], were investigated in detail via UV-vis absorption, 1H nuclear magnetic resonance (NMR) spectroscopy, and electrospray ionization time-of-flight (ESI-TOF) mass spectrometry; the two photoproducts obtained from the photoreaction of Pt1 were also successfully identified via X-ray analysis. The absorption bands of the Ni1 and Pt1 complexes were very similar, centered around 530 nm, and were assigned as an intraligand charge transfer transition of the hydrazone moiety. The absorption spectrum of Pt1 in a CH3CN solution changed drastically upon photoirradiation (λ = 530 nm), whereas no change was observed for Ni1. 1H NMR and ESI-TOF mass spectra under various conditions suggested that the photoexcited Pt1* reacts with dissolved dioxygen to form a reactive intermediate, and the ensuing dark reactions afforded two different products without any decomposition. In contrast to the simple photo-oxidation of HL to form a phosphine oxide HL(P═O), the X-ray crystallographic analyses of the photoproducts clearly indicate the formation of a mononuclear Pt complex with the oxygenated hydrazone ligand (Pt1O) and a dinuclear Pt complex with the oxygenated and dimerized hydrazone ligand (Pt2). The photosensitized reaction in the presence of an 1O2-generating photosensitizer, methylene blue (MB), also produced Pt1O and Pt2, indicating that the reaction between 1O2 and ground-state Pt1 is the important step. In a highly viscous dimethyl sulfoxide solution, Pt1 was slowly, but quantitatively, converted to the mononuclear form, Pt1O, without the formation of the dinuclear product, Pt2, upon photoirradiation (and in the reaction photosensitized by MB), suggesting that this photoreaction of Pt1 involves at least one diffusion-controlled reaction. On the other hand, the same complexes Pt1O and Pt2 were also produced in the degassed solution, probably because of the reaction of the photoexcited Pt1* with the biradical character and H2O.
Inorganic chemistry.Inorg Chem.2014 Feb 17. [Epub ahead of print]
Photoreactivities of Ni(II)- and Pt(II)-hydrazone complexes, [NiCl(L)] (Ni1) and [PtCl(L)] (Pt1), respectively [HL = 2-(diphenylphosphino)benzaldehyde-2-pyridylhydrazone], were investigated in detail via UV-vis absorption, 1H nuclear magnetic resonance (NMR) spectroscopy, and electrospray ionization
NOVEL INTRAMOLECULAR CYCLIZATION-SKELETAL REORGANIZATION OF 2-ARYLTHIAZOLES UNDER PHOTOIRRADIATION (Dedicated to Professor Isao Kuwajima on the occasion of his 77th birthday)
Arai Noriyoshi,Mizota Moe,Ohkuma Takeshi
Heterocycles : an international journal for reviews and communications in heterocyclic chemistry 90(1), 607-616, 2015-01-01
Synthesis and Properties of (Terthiophene)4–Poly(amidoamine)–C60 Pentad
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Bulletin of the Chemical Society of Japan 88(5), 736-745, 2015
… The photocurrent of a photopolymerized 8a film on a FTO (poly-8aphoto/FTO) electrode formed by photoreaction of 8a/FTO, is approximately 6 times greater than that of the 8a/FTO electrode. …
Photoreaction definition, a chemical reaction that involves or requires light. See more. Thesaurus Translate Reference Word of the Day Blog Slideshows Apps by Dictionary My Account Log Out Log In follow Dictionary.com Is it ...
Definition of PHOTOREACTION: a photochemical reaction One goose, two geese. One moose, two... moose. What's up with that? » First Known Use of PHOTOREACTION 1909 Rhymes with PHOTOREACTION alarm reaction, decimal fraction ...