75 research outputs found
Clinical features as a predictor of laparotomy findings in supradiaphragmatic stage I and II Hodgkin\u27s disease
Influence of alkyl gallate surface modified TiO2 nanoparticles on the rheological properties of alkyd resin
The influence of alkyl gallate surface modified TiO2 nanoparticles on the
rheological properties of long oil alkyd resin, based on soybean oil, was
investigated. Surface modification of TiO2 nanoparticles, obtained by acid
catalyzed hydrolysis of titanium tetraisopropoxide, was performed with
propyl, lauryl or cetyl gallate. The average particle size and the crystal
structure of synthesized nanoparticles were estimated by transmission
electron microscopy and X-ray diffraction. The gallate chemisorption onto
surface of TiO2 nanoparticles was confirmed by FTIR and UV spectroscopy.
The examined dispersions were prepared by the addition of modified TiO2
nanoparticles to the commercial alkyd resin. The viscosity of the prepared
dispersions was higher than viscosity of the pure resin and it increased with
increasing length of hydrophobic part of the gallate used for surface
modification of TiO2 nanoparticles. This occurred because the increase of
their hydrodynamic volume led to the increase of the effective volume
fraction of particles in dispersion
Adsorption of Organophosphate Pesticide Dimethoate on Gold Nanospheres and Nanorods
Organophosphorus pesticide dimethoate was adsorbed onto gold nanospheres and nanorods in aqueous solution using batch technique. Adsorption of dimethoate onto gold nanoparticles was confirmed by UV-Vis spectrophotometry, TEM, AFM, and FTIR analysis. The adsorption of nanospheres resulted in aggregation which was not the case with nanorods. Nanoparticles adsorption features were characterized using Langmuir and Freundlich isotherm models. The Langmuir adsorption isotherm was found to have the best fit to the experimental data for both types of nanoparticles. Adsorption capacity detected for nanospheres is 456 mg/g and for nanorods is 57.1 mg/g. Also, nanoparticles were successfully used for dimethoate removal from spiked drinking water while nanospheres were shown to be more efficient than nanorods
MimoDB 2.0: a mimotope database and beyond
Mimotopes are peptides with affinities to given targets. They are readily obtained through biopanning against combinatorial peptide libraries constructed by phage display and other display technologies such as mRNA display, ribosome display, bacterial display and yeast display. Mimotopes have been used to infer the protein interaction sites and networks; they are also ideal candidates for developing new diagnostics, therapeutics and vaccines. However, such valuable peptides are not collected in the central data resources such as UniProt and NCBI GenPept due to their ‘unnatural’ short sequences. The MimoDB database is an information portal to biopanning results of random libraries. In version 2.0, it has 15 633 peptides collected from 849 papers and grouped into 1818 sets. Besides the core data on panning experiments and their results, broad background information on target, template, library and structure is included. An accompanied benchmark has also been compiled for bioinformaticians to develop and evaluate their new models, algorithms and programs. In addition, the MimoDB database provides tools for simple and advanced searches, structure visualization, BLAST and alignment view on the fly. The experimental biologists can easily use the database as a virtual control to exclude possible target-unrelated peptides. The MimoDB database is freely available at http://immunet.cn/mimodb
Examining the Interactome of Huperzine A by Magnetic Biopanning
Huperzine A is a bioactive compound derived from traditional Chinese medicine plant Qian Ceng Ta (Huperzia serrata), and was found to have multiple neuroprotective effects. In addition to being a potent acetylcholinesterase inhibitor, it was thought to act through other mechanisms such as antioxidation, antiapoptosis, etc. However, the molecular targets involved with these mechanisms were not identified. In this study, we attempted to exam the interactome of Huperzine A using a cDNA phage display library and also mammalian brain tissue extracts. The drugs were chemically linked on the surface of magnetic particles and the interactive phages or proteins were collected and analyzed. Among the various cDNA expressing phages selected, one was identified to encode the mitochondria NADH dehydrogenase subunit 1. Specific bindings between the drug and the target phages and target proteins were confirmed. Another enriched phage clone was identified as mitochondria ATP synthase, which was also panned out from the proteome of mouse brain tissue lysate. These data indicated the possible involvement of mitochondrial respiratory chain matrix enzymes in Huperzine A's pharmacological effects. Such involvement had been suggested by previous studies based on enzyme activity changes. Our data supported the new mechanism. Overall we demonstrated the feasibility of using magnetic biopanning as a simple and viable method for investigating the complex molecular mechanisms of bioactive molecules
Thermodynamic study of interactions between ZnO and ZnO binding peptides using isothermal titration calorimetry
Whilst material specific peptide binding sequences have been identified using a combination of combinato-rial methods and computational modelling tools, a deep molecular level understanding of the fundamental principles through which these interactions occur and in some instances modify the morphology of inorganic materials is far from being fully realized. Understanding the thermodynamic changes that occur during peptide-inorganic interactions and correlating these to structural modifications of the inorganic materials could be the key to achieving and mastering con-trol over material formation processes. This study is a detailed investigation applying isothermal titration calorimetry (ITC) to directly probe thermodynamic changes that occur during interaction of ZnO binding peptides (ZnO-BPs) and ZnO. The ZnO-BPs used are reported sequences G-12 (GLHVMHKVAPPR), GT-16 (GLHVMHKVAPPR-GGGC) and alanine mutants of G-12 (G-12A6, G-12A11 and G-12A12) whose interaction with ZnO during solution synthesis studies have been extensively investigated. The interactions of the ZnO-BPs with ZnO yielded biphasic isotherms comprising both an endo-thermic and an exothermic event. Qualitative differences were observed in the isothermal profiles of the different pep-tides and ZnO particles studied. Measured ΔG values were between -6 and -8.5 kcal/mol and high adsorption affinity val-ues indicated the occurrence of favourable ZnO-BP-ZnO interactions. ITC has great potential in its use to understand peptide-inorganic interactions and with continued development, the knowledge gained may be instrumental for simplifi-cation of selection processes of organic molecules for the advancement of material synthesis and design
MICORRIZAS ARBUSCULARES NO CRESCIMENTO DE LEGUMINOSAS ARBÓREAS EM SUBSTRATO CONTENDO REJEITO DE MINERAÇÃO DE CARVÃO
Bimodal dynamics of primary metabolism-related responses in tolerant potato-Potato virus Y interaction
Preparation and characterization of poly(styren)/TiO2 nanocomposites
46th Meeting of the Serbian Chemical Society : February 21, Belgrade, 2008
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