Residual risk of Pseudomonas aeruginosa waterborne contamination in an intensive care unit despite the presence of filters at all water points-of-use.

Objective: To assess the residual risk of waterborne contamination by Pseudomonas aeruginosa from a water network colonized by a single genotype [sequence type (ST) 299] despite the presence of antimicrobial filters in a medical intensive care unit (ICU).

Methods: During the first 19-month period since the ICU opened, contamination of the water network was assessed monthly by collecting water upstream of the filters. Downstream water was also sampled to assess the efficiency of the filters.

Infectious disease model generalization based on diffuse perturbations under conditions of body's temperature reaction.

The infectious disease mathematical model is generalized based on the influence of diffuse perturbations on the development of the disease under conditions of the body's temperature reaction. The singularly perturbed model problem was reduced with delay to a sequence of problems without delay, for which the corresponding asymptotic expansions of solutions are obtained. The presented results of computer modeling in various situational states illustrate the expected decrease in the growth rate of the number of viral particles as a result of the action of the body's protective temperature reaction.

Assessment of the efficacy of slow-release formulations of the tribenuron-methyl herbicide in field-grown spring wheat.

The efficacy of slow-release formulations of tribenuron-methyl (TBM) embedded in the matrix of degradable poly(3-hydroxybutyrate) blended with birch wood flour [polymer/wood flour/herbicide 50/30/20 wt.%] was compared with the efficacy of TBM as the active ingredient of the Mortira commercial formulation, which was applied as post-emergence spray to treat spring wheat cv. Novosibirskaya 15.

Efficacy of embedded metribuzin and tribenuron-methyl herbicides in field-grown vegetable crops infested by weeds.

The purpose of the present study was to investigate the efficacy of the experimental formulations of the metribuzin (MET) and tribenuron-methyl (TBM) herbicides embedded in the matrix of degradable poly-3-hydroxybutyrate blended with wood flour in field-grown tomato and beet crops infested by weeds. There is a necessity to develop environmentally friendly and effective means to protect plants because of the shortcomings of the free herbicide forms such as the environmentally unsafe spray application of solutions and suspensions of the widespread metribuzin and tribenuron-methyl herbicides, removal from soil during watering events and rains, and transport to natural aquatic environments, where the herbicides accumulate in the trophic chains of biota. Free TBM is also rapidly inactivated in soil and metabolized to nontoxic products in plants.

Biological effects of the free and embedded metribuzin and tribenuron-methyl herbicides on various cultivated weed species.

The present study addresses the herbicidal activity and biological effects of the metribuzin (MET) and tribenuron-methyl (TBM) herbicides used to control various weed species ( and ). The effects of the free herbicides and the herbicides embedded in granules of degradable polymer poly-3-hydroxybutyrate [P(3HB)] blended with birch wood flour were compared. Metribuzin, regardless of the form, caused 100% mortality of the three weeds by day 21.

Thermal, mechanical and biodegradation studies of biofiller based poly-3-hydroxybutyrate biocomposites.

Biodegradable poly-3-hydroxybutyrate [P(3HB)] and natural fillers - clay, peat, and birch wood flour - were used to prepare powdered composites to form pellets and granules. Pellets were produced by cold pressing of polymer and filler powder whereas granules were produced from the powders wetted with ethanol. Characterization techniques like IR spectroscopy, differential scanning calorimetry, X-ray analysis, mechanical analysis and electron microscopy were employed to study the properties of the initial P(3HB) and fillers and the composites.

Tracking carbapenemase-producing bacteria by molecular typing: Population diversity and sampling pitfall.

While typing methods are increasingly refined, the sampling of bacteria to be typed in healthcare-associated infection context retains less attention. Through 2 emblematic cases of in-hospital transmission of extensively drug-resistant bacteria producing carbapenemases, we demonstrate the impact of colony sampling in typing results. Because of intra-population diversity, typing several colonies of same species and resistotype was needed to fully track the transmission among patients.

Tracking the spread routes of opportunistic premise plumbing pathogens in a haematology unit with water points-of-use protected by antimicrobial filters.

Background: Water networks in hospitals are frequently contaminated by opportunistic premise plumbing pathogens (OPPPs) leading to installation of antimicrobial filters on water points-of-use (POU) in order to limit patients' exposure.

Aim: To assess the spread of OPPPs through secondary water routes (outside the plumbing system) in an adult haematology unit in which 52 out of 73 water POU were high risk for patients and protected by antimicrobial filters.

Methods: An observational audit identified six secondary water routes for which bacteria tracking and typing were performed in 315 surface samplings.

Computational approaches to the design of novel 5-HT6 R ligands.

5-Hydroxytryptamine (5-HT, serotonin) subtype 6 receptor (5-HT6 receptor, 5-HT6 R) belongs to a 5-HT subclass of a relatively wide G protein-coupled receptor (GPCR) family. Accumulated biological data indicate that 5-HT6 R antagonists and agonists have a great potential for the treatment of neuropathological disorders, such as Parkinson's disease, Alzheimer's disease, and schizophrenia. A number of painstaking efforts have been made toward the design of novel 5-HT6 R ligands; however, there are still no drugs that successfully passed all the clinical trials and entered the market, except for several multimodal ligands.

Structural basis for the binding affinity of a homologous series of synthetic phenoxazone drugs with DNA: NMR and molecular mechanics analysis.

The molecular basis of the marked structure-activity relationship for a homologous series of DNA-binding phenoxazone drugs (ActII-ActIV) has been investigated by NMR spectroscopy and molecular mechanics. The spatial structures of the complexes between the drugs and a model deoxytetranucleotide, 5'-d(TpGpCpA), have been determined by molecular mechanics methods using homonuclear (1)H-(1)H 2D-NOESY and heteronuclear (1)H-(31)P (HMBC) NMR spectroscopic data. Observed intermolecular NOE contacts and equilibrium binding studies confirm that the binding affinity of the synthetic phenoxazone derivatives with d(TGCA) decreases with an increase in the number of CH(2) groups in the dimethylaminoalkyl side chains, i.

Spectrophotometric investigation of the hetero-association of caffeine and thiazine dye in aqueous solution.

The self-association of thiazine dye, Methylene Blue (MB), and its hetero-association with Caffeine (CAF), were studied in aqueous solution by means of spectrophotometry in the visible range of spectrum. Concentration and temperature dependences of molar absorption of the interacting molecules were used to analyse dynamic equilibrium in solution in terms of two-component model of molecular hetero-association. The magnitudes of equilibrium dimerization and hetero-association constants as well as thermodynamic parameters, enthalpy and entropy, were determined.

NMR investigation of the complexation of daunomycin with deoxytetranucleotides of different base sequence in aqueous solution.

500 MHz NMR spectroscopy has been used to investigate the complexation of the anthracycline antibiotic daunomycin (DAU) with self-complementary deoxytetranucleotides, 5'-d(CGCG), 5'-d(GCGC), 5'-d(TGCA), 5'-d(ACGT) and 5'-d(AGCT), of different base sequence in aqueous salt solution. 2D homonuclear 1H NMR spectroscopy (TOCSY and NOESY) and heteronuclear 1H - 31P NMR spectroscopy (HMBC) have been used for complete assignment of the non-exchangeable protons and the phosphorus resonance signals, respectively, and for a qualitative determination of the preferred binding sites of the drug. Analysis shows that DAU intercalates preferentially into the terminal sites of each of the tetranucleotides and that the aminosugar of the antibiotic is situated in the minor groove of the tetramer duplex, partly eclipsing the third base pair.

1H-NMR determination of the thermodynamics of drug complexation with single-stranded and double-stranded oligonucleotides in solution: ethidium bromide complexation with the deoxytetranucleotides 5'-d(ApCpGpT), 5'-d(ApGpCpT), and 5'-d(TpGpCpA).

The thermodynamical parameters (free energy, enthalpy, and entropy) of complex formation between ethidium bromide and single-stranded and double-stranded tetranucleotides of different base sequence [5-d(TpGpCpA), 5-d(ApCpGpT), and 5-d(ApGpCpT) have been determined from the temperature dependencies of 500 MHz proton nmr chemical shifts. The analysis enables the contributions to be differentiated for the formation of different types of complexes (1:1, 2:1, 1.2 and 2:2) in aqueous solution.