The sorption kinetics and thermodynamics of 1,3-dinitrobenzene (DNB), m-nitrotoluene (mNT), p-nitrophenol (pNP), and nitrobenzene (NB) on as-grown and nitric acid-oxidized multiwalled carbon nanotubes (MWCNTs) were investigated. The sorption kinetics was well described by a pseudo-second-order rate model, while both Langmuir and Freundlich models described the sorption isotherms well and the so...

This paper reports a first microbial biosensor for rapid and cost-effective determination of organophosphorus pesticides fenitrothion and EPN. The biosensor consisted of recombinant PNP-degrading/oxidizing bacteria Pseudomonas putida JS444 anchoring and displaying organophosphorus hydrolase (OPH) on its cell surface as biological sensing element and a dissolved oxygen electrode as the transduce...

In this work, the adsorption kinetics of p-nitrophenol (PNP) onto several commercial activated carbons (ACs) with different textural and geometrical characteristics was studied. For this aim, a homogeneous diffusion solid model (HDSM) was used, which does take the adsorbent shape into account. The HDSM was solved by means of the finite element method (FEM) using the commercial software COMSOL. ...

Induction of UDP-glucuronosyltransferases (UGTs) toward thyroxine (T4) and p-nitrophenol (pNP) by 3-methylcholanthrene (MC), dexamethasone (DEX), clofibrate (Cl), and MC combined with DEX or Cl was studied in rat hepatocyte culture. We have developed a sensitive method for the measurement of glucuronide conjugates of the two substrates based on HPLC analysis of culture medium. MC, Cl, or DEX in...

Legionella pneumophila, the agent of Legionnaires' disease, is an intracellular pathogen of protozoa and macrophages. Previously, we had determined that the Legionella pilD gene is involved in type IV pilus biogenesis, type II protein secretion, intracellular infection, and virulence. Since the loss of pili and a protease do not account for the infection defect exhibited by a pilD-deficient str...

The cytochrome P450 enzymes (P450s) that mediate mammalian xenobiotic metabolism are highly versatile monooxygenases, which show wide and overlapping substrate ranges but generally poor catalytic rates. Re-engineering of these P450s may enable the development of useful biocatalysts for industrial applications. In the current study, restriction enzyme-mediated DNA family shuffling was used to cr...

In this study, we investigated the catalytic properties of N,N-dimethylformamide (DMF)-stabilized gold nanoclusters (AuNCs) in the reduction of 4-nitrophenol (PNP) to 4-aminophenol by NaBH(4), a well known model reaction to be catalyzed by metal surfaces. The DMF-stabilized AuNCs were prepared in DMF by a surfactant-free method. The DMF-stabilized AuNCs showed high catalytic activity even when ...

Three Ag nanoparticle (NP) colloids are produced from borohydride reduction of silver nitrate in water by varying the amount sodium citrate. These nanoparticles used as photocatalysts with H2O2 to degrade a p-nitrophenol (PNP) solution. X-ray diffraction patterns have shown production metallic nanoparticles, whatever concentration The transmission electron microscope images these NPs highlighte...

Mononuclear copper(II) complexes based on the symmetric tridentate N3-donor ligands bis(pyridin-2-yl)methyl)amine (HBPA, L1) and its methylated counterpart, di(2-pyridylmethyl)amine (MeDPA, L2) have been prepared, characterized, demonstrated as functional models for lytic polysaccharide monooxygenase. These disrupt synthetic substrate, such p-nitrophenyl--D-glucopyranoside (-PNPG) into p-nitr...