In Situ, Real-Time FT-IR/CIR/ATR Study of the Biocorrosion of Copper by Gum Arabic, Alginic Acid, Bacterial Culture Supernatant and Pseudomonas atlantica Exopolymer

1989 ◽  
Vol 43 (6) ◽  
pp. 1062-1067 ◽  
Author(s):  
John G. Jolley ◽  
Gill G. Geesey ◽  
Michael R. Hankins ◽  
Randy B. Wright ◽  
Paul L. Wichlacz
Keyword(s):  
Aqueous Solution ◽  
Real Time ◽  
Culture Supernatant ◽  
Bacterial Culture ◽  
Alginic Acid ◽  
Gum Arabic ◽  
Bacterial Culture Supernatant ◽  
Ft Ir ◽  
Simulated Seawater

Thin films (2.0 nm) of copper on germanium internal reflection elements (IREs) were exposed to 10% gum arabic (aqueous solution), 2% alginic acid (aqueous solution), 1% bacterial culture supernatant (BCS, simulated seawater solution), and 0.5% Pseudomonas atlantica exopolymer (simulated seawater solution) and monitored in situ, real time, with the use of Fourier transform infrared/cylindrical internal reflection/attenuated total reflection spectroscopy as a function of time at ambient conditions. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium IREs. Results indicate that some of the copper was removed from the Cu/Ge interface by all four polymers and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the four polymers in the order of alginic acid < gum arabic < BCS > Pseudomonas atlantica exopolymer. The FT-IR/CIR/ATR technique can be successfully used to monitor biocorrosion systems in in situ, real-time settings.

scholarly journals The Type II Secreted Lipase/Esterase LesA is a Key Virulence Factor Required for Xylella fastidiosa Pathogenesis in Grapevines

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Rafael Nascimento ◽  
Hossein Gouran ◽  
Sandeep Chakraborty ◽  
Hyrum W. Gillespie ◽  
Hebréia O. Almeida-Souza ◽  
...  
Keyword(s):  
Culture Supernatant ◽  
Bacterial Culture ◽  
Xylella Fastidiosa ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Type Ii ◽  
Symptom Development ◽  
Bacterial Titer ◽  
Bacterial Culture Supernatant ◽  
Xylem Elements

Abstract Pierce’s disease (PD) of grapevines is caused by Xylella fastidiosa (Xf), a xylem-limited gamma-proteobacterium that is responsible for several economically important crop diseases. The occlusion of xylem elements and interference with water transport by Xf and its associated biofilm have been posited as the main cause of PD symptom development; however, Xf virulence mechanisms have not been described. Analysis of the Xf secretome revealed a putative lipase/esterase (LesA) that was abundantly secreted in bacterial culture supernatant and was characterized as a protein ortholog of the cell wall-degrading enzyme LipA of Xanthomonas strains. LesA was secreted by Xf and associated with a biofilm filamentous network. Additional proteomic analysis revealed its abundant presence in outer membrane vesicles (OMVs). Accumulation of LesA in leaf regions associated positively with PD symptoms and inversely with bacterial titer. The lipase/esterase also elicited a hypersensitive response in grapevine. Xf lesA mutants were significantly deficient for virulence when mechanically inoculated into grapevines. We propose that Xf pathogenesis is caused by LesA secretion mediated by OMV cargos and that its release and accumulation in leaf margins leads to early stages of observed PD symptoms.

Preparation of PLA and PLGA Magnetic Microspheres with T-Shaped Microchannel Reactor

2014 ◽  
Vol 609-610 ◽  
pp. 425-429 ◽  
Author(s):  
Peng Liu ◽  
Yi Zhong ◽  
Yan Luo
Keyword(s):  
Aqueous Solution ◽  
Solvothermal Method ◽  
Gum Arabic ◽  
Magnetic Microspheres ◽  
Microchannel Reactor ◽  
Characteristic Functional ◽  
Dichloromethane Solution ◽  
New Approach ◽  
Ft Ir ◽  
Uniform Particle Size

Monodisperse magnetic microspheres with biomaterial of polylactic acid (PLA) or poly lactic-co-glycolic acid (PLGA) as shell were successfully prepared via T-shaped microchannel reactor in this paper. Hydrophilic ferriferrous oxide (Fe3O4) with highly magnetic responsiveness was obtained by solvothermal method. Aqueous solution of Fe3O4 was then emulsified into a dichloromethane solution of PLA or PLGA to generate water-in-oil (W/O) emulsion. Different stabilizer, i.e. polyvinyl alcohol (PVA), gelatin or gum arabic, was then added into the W/O emulsion for the purpose of more stable system. Subsequently, W/O/W composite emulsion was formed by injecting W/O emulsion into PVA aqueous solution at the T-shaped joint of microchannel reactor. Magnetic microspheres were finally prepared by solvent evaporation in the microchannel. The characteristic functional groups of Fe3O4 were characterized by Fourier transform infrared spectroscopy (FT-IR). The magnetic property was measured with vibrating sample magnetometer (VSM). The morphology of all samples was observed by scanning electron microscopy (SEM). It was found that the magnetic microspheres exhibit a uniform particle size in micro-scale. Therefore, the T-shaped microchannel reactor was expected to create a new approach for fabricating magnetic microspheres.

A hemicyanine-based fluorescent probe for hydrazine detection in aqueous solution and its application in real time bioimaging of hydrazine as a metabolite in mice

2019 ◽  
Vol 7 (20) ◽  
pp. 3197-3200 ◽  
Author(s):  
Tao Li ◽  
Jian Liu ◽  
Linjiang Song ◽  
Zicheng Li ◽  
Qingrong Qi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Real Time ◽  
Fluorescent Probe

A fluorescent probe, Hcy-Ac, was developed for the monitoring of in situ hydrazine release during the metabolism of isoniazid.

scholarly journals In Situ Synthesis of Poly(methyl methacrylate)/SiO2Hybrid Nanocomposites via “Grafting Onto” Strategy Based on UV Irradiation in the Presence of Iron Aqueous Solution

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hong Zhang ◽  
Chao Li ◽  
Jinshan Guo ◽  
Limin Zang ◽  
Jiahe Luo
Keyword(s):  
Aqueous Solution ◽  
Methyl Methacrylate ◽  
Uv Irradiation ◽  
Hybrid Composites ◽  
Monomer Conversion ◽  
Hybrid Particles ◽  
Poly Methyl Methacrylate ◽  
Ft Ir ◽  
Grafting Onto

Poly(methyl methacrylate)/SiO2(PMMA/SiO2) hybrid composites were prepared via “grafting onto” strategy based on UV irradiation in the presence of iron aqueous solution. Two steps were used to graft polymethyl methacrylate (PMMA) onto the surface of nanosilica, anchoring 3-(methacryloxy) propyl trimethoxysilane (MPTS) onto the surface of nanosilica to modify it with double bonds, and then grafting PMMA onto the surface of nanosilica with FeCl3as photoinitiator. The products were characterized by FT-IR, TGA, TEM, DLS, and XPS. The results showed that it is easy to graft PMMA onto the surface of nanosilica under UV irradiation, and the hybrid particles are monodisperse and have core-shell structure with nanosilica as the core and PMMA layers as the shell. Furthermore, the products initiated by FeCl3have higher monomer conversion, percent grafting, and better monodispersion compared with the products initiated by traditional photoinitiator such as 2-hydroxy-4-(2-hydroxyethoxy)-2-methyl-propiophenone (Irgacure 2959).

Development and validation of an in situ and real-time quantification method for bicarbonate, carbonate and orthophosphate ions by ATR FT-IR spectroscopy in aqueous solutions

The Analyst ◽  
2018 ◽  
Vol 143 (18) ◽  
pp. 4387-4393 ◽  
Author(s):  
Pierre-Olivier Morisset ◽  
Jonathan Gagnon ◽  
Réjean Tremblay ◽  
Jean-Sébastien Deschênes
Keyword(s):  
Ir Spectroscopy ◽  
Real Time ◽  
Inorganic Carbon ◽  
Bioprocess Monitoring ◽  
Quantification Method ◽  
Phosphate Ions ◽  
Ft Ir ◽  
Development And Validation ◽  
Ft Ir Spectroscopy

An in situ real-time quantification method for inorganic carbon and phosphate ions in water using ATR FT-IR suitable for bioprocess monitoring is described.

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