Dibenzothiophene (DBT) and their derivatives, accounting for the major part of the sulfur components in crude oil, make one of the most significant pollution sources. The DBT sulfone monooxygenase BdsA, one of the key enzymes in the "4S" desulfurization pathway, catalyzes the oxidation of DBT sulfone to 2'-hydroxybiphenyl 2-sulfonic acid (HBPSi). Here, we determined the crystal structure of Bds...

On the assumption of the theory that the sulfone of a penam derivative should effectively act as a suicide substrate against beta-lactamases to which the parent compound is a poor substrate, the action of cloxacillin sulfone on four different types of beta-lactamases was studied. As we expected, cloxacillin sulfone showed strong mechanism-based irreversible inactivation against type Ib penicill...

A cell-impermeable diffusion chamber technique has been developed that lends itself to growth studies of Mycobacterium lepraemurium. This technique, in which the organism grows within macrophage cultures inside the chambers that are maintained on monolayer cultures of macrophages, provides a method for a strict in vitro evaluation of antileprosy drugs without the influence of a multiplicity of ...

Organic-inorganic composite materials have attracted great attention because of their potential to combine the features of organic materials with those of inorganic materials. Particularly organic-metal composite such as polymer-silver are promising functional materials in areas ranging from electronic and optical devices to biosensing, antimicrobial agents and catalysis. In general, there are ...

A complete and permanent hydrophilic modification of polyethersulfone (PES) membranes is achieved by argon plasma treatment followed by polyacrylic acid (PAA) grafting in vapor phase. Both Ar plasma treatment alone and post-PAA grafting rendered a complete hydrophilicity to the PES membranes. The hydrophilicity of the membranes treated with only the Ar plasmas is not, however, permanent. In con...

Hydrophilic polyethersulfone (PES) hollow fiber membranes were prepared via non-solvent induced phase separation (NIPS) by addition of polymeric additives as a membrane modifying agent. The effect of the addition of hydrophilic surfactant Pluronic F127, Polyivinylpyrrolidone (PVP), and Tetronic 1307 on the performance of the final PES hollow-fiber membrane was investigated. The morphology of fa...

A flow biosensor for the detection of toxicity in water using the ammonia-oxidizing bacterium (AOB) Nitrosomonas europaea as a bioreceptor and a polymeric membrane ammonium-selective electrode as a transducer is described. The system is based on the inhibition effects of toxicants on the activity of AOB, which can be evaluated by measuring the ammonium consumption rates with the ammonium-select...

Biofilm is a significant cause for membrane fouling. Antibacterial-coated surfaces can inhibit biofilm formation by killing bacteria. In this study, polyethersulfone (PES) microfiltration membrane was photografted by four antibiotic quaternary ammonium compounds (QACs) separately, which were synthesized from dimethylaminoethyl methacrylate (DMAEMA) by quaternization with butyl bromide (BB), oct...

Bis(methylsulfonamido) sulfone, C(2)H(8)N(2)O(6)S(3) or SO(2)(NHSO(2)CH(3))(2), was synthesized from imidobis(sulfonyl chloride), HN(SO(2)Cl)(2), and bis(trimethylsilyl)methane, CH(2)[Si(CH(3))(3)](2), in chlorotrimethylsilane solution. In the solid state, there are two independent molecules linked by two N-H...O hydrogen bridges into infinite chains parallel to the b axis. The central S atoms ...

The "no reaction" lateral flow assay (nrLFA) uses a simplified LFA structure with no conjugate pad and no stored reagents. In the nrLFA, the capillary-based transport time or distance is the key indicator, rather than the outcome of a biochemical reaction. Hence, the calibration and reproducibility of the nrLFA device are critical. The capillary flow properties of several membrane types (nitroc...