The reaction of the common pain reliever acetaminophen (paracetamol, 4-acetamidophenol) with hypochlorite was investigated over time under conditions that simulate wastewater disinfection. Initially, the reaction was studied in pure water at neutral pH (7.0), a range of reaction times (2-90 min), and a molar excess of hypochlorite (2-57 times) relative to the acetaminophen concentration. The re...

Electron-transfer flavoprotein (ETF)-ubiquinone (2,3-dimethoxy-5-methyl-1,4-benzoquinone) oxidoreductase (ETF-QO) is a membrane-bound iron-sulphur flavoprotein that participates in an electron-transport pathway between eleven mitochondrial flavoprotein dehydrogenases and the ubiquinone pool. ETF is the intermediate electron carrier between the dehydrogenases and ETF-QO. The steady-state kinetic...

Controlled shortening of the poly(A) tail of mRNAs is the first step in eukaryotic mRNA decay and can also be used for translational inactivation of mRNAs. The CCR4-NOT complex is the most important among a small number of deadenylases, enzymes catalyzing poly(A) tail shortening. Rates of poly(A) shortening differ between mRNAs as the CCR4-NOT complex is recruited to specific mRNAs by means of ...

We report the characterization and determination of 2,6-dichloro-1,4-benzoquinone and three new disinfection byproducts (DBPs): 2,6-dichloro-3-methyl-1,4-benzoquinone, 2,3,6-trichloro-1,4-benzoquinone, and 2,6-dibromo-1,4-benzoquinone. These haloquinones are suspected bladder carcinogens and are likely produced during drinking water disinfection treatment. However, detection of these haloquinon...

A polynucleotide helical structure containing two strands of poly(A) and one of poly(U) is reported. As shown by spectroscopic observations, the complex only forms when the poly(A) strands are of Mr between 9000 and 50,000 (degree of polymerization congruent to 28-150), whereas the size of the poly(U) strand has no effect. This limitation may explain why poly(A.A.U) was not seen in previous inv...

Using CD measurements the complex formation of Netropsin (Nt) with poly(dA-dC).poly(dT-dG) and its stability against high salt concentrations is compared with that of poly(dA).poly(dT) and poly(dA-dT).POLY(DT-dA). It is experimentally shown that the insertion of a dG.dC pair in dA.dT sequences strongly reduces the specific interaction of Nt with DNA duplexes. The specificity of the interaction ...

Poly(ethyleneglycol)-b-poly(4-vinylpyridine) (PEG-b-P4VP) and zinc meso-5,10,15,20-tetrakis-(4-sulfonatophenyl)porphyrin (ZnTPPS) form complex micelles based on electrostatic interactions. The complex micelles have a core-shell structure that can effectively prevent the demetallization and aggregation of ZnTPPS in acidic aqueous solutions (pH < 4.0).

Many steps in nuclear RNA processing, surveillance, and degradation require TRAMP, a complex containing the poly(A) polymerase Trf4p, the Zn-knuckle protein Air2p, and the RNA helicase Mtr4p. TRAMP polyadenylates RNAs designated for decay or trimming by the nuclear exosome. It has been unclear how polyadenylation by TRAMP differs from polyadenylation by conventional poly(A) polymerase, which pr...

poly methyl methacrylate (pmma) is the most common material used in prosthodontics. several studies indicate a breakdown of the number of very high resin bases after 2 to 3 years to avoid breaking bass and several attempts have been made, such as altering the chemical structure of resin by adding causes cross linking or copolymerization. the innovative method for improving the physical properti...