13 research outputs found
The use of spa and phage typing for characterization of clinical isolates of methicillin-resistant Staphylococcus aureus in the University Clinical Center in Gdańsk, Poland
The emergence of spa types and spa–clonal complexes (CC) among clinical methicillin-resistant Staphylococcus aureus isolates collected from the University Clinical Center in Gdańsk between 2008 and 2009 were investigated. Phage typing was used as the initial screening in the study. The basic set of phages and the additional set of phages were used. Most of the isolates (56 %) belonged to the phage group III. With the additional set of phages, eight types were found, with predominant one MR8 (50 %). Sixteen distinct spa types were observed. The most frequent were t003 (22 %), t151 (16 %), and t008 (12 %). The spa types were clustered into two spa-CC and eight singletons. The predominant CC010 (50 %) consisted of six types, with the most common t003 (36.7 %) and t151(26.7 %), and in 80 % was identified as staphylococcal chromosomal casette mec (SCCmec) type II. The second cluster has no founder (12 %) with only two spa types: t037 belonging to SCCmec type III and t029. In the most frequent singleton, spa type t008 alone was clustered in 12 % of the isolates. All singletons correspond to SCCmec type IV. The CC010 was distributed in most of the hospital wards, corresponded to Multilocus sequence typing type ST5/ST225 and was constantly present throughout the observed period. The isolates of CC010 generally belonged to the phage group III, and most of them (53.3 %) were resistant to erythromycin, clindamycin, and ciprofloxacin. The concordance between spa-clone and phage type was very high, but the same phage type MR8 was observed within different spa types of the predominant clone
Comparative investigations of drops velocity in a liquid-liquid system and liquid velocity in a homogeneous system
Za pomocą techniki PIV zmierzono i porównano prędkości kropel oleju w wodzie i prędkości wody w układzie jednofazowym. Badania przeprowadzono w mieszalniku zbiornikowym z mieszadłem Rushtona. Badania wykazały maksymalną różnicę w prędkościach rzędu 30% w okolicy mieszadła oraz porównywalne wartości szybkości dyssypacji energii. Przy niskich ułamkach objętościowych fazy rozproszonej, średnice kropel można przewidywać wykorzystując modele CFD dla układów jednofazowych.Velocities of oil drops in emulsion and water in a homogeneous system were measured using PIV technique. Investigations were carried out in a tank equipped with the Rushton turbine. The maximum difference between velocities was observed close to the impeller and was equal to 30%. However, there was no difference in values of energy dissipation rate in both systems. For a low dispersed phase volume fraction, drop diameters can be predicted using CDF models for a homogeneous system
Design, Synthesis, and Characterization of a Bifunctional Chelator with Ultrahigh Capacity for Uranium Uptake from Seawater Simulant
Informed by density functional theory
calculations, a novel bifunctional
chelator, (<i>Z</i>)-2-[2-(<i>N</i>′-hydroxycarbamimidoyl)phenoxy]benzoic
acid, was designed and synthesized for ultrahigh uranium uptake from
seawater. Investigation of the ligand for uranium sorption was conducted
in artificial seawater (pH = 8.2). An exceptional uranium uptake of
553 mg of uranium (g of sorbent)<sup>−1</sup> was obtained
with a theoretical saturation capacity of 710 mg g<sup>–1</sup> obtained by fitting isotherm data with the Langmuir–Freundlich
model. The resulting yellow precipitate was characterized via X-ray
absorption fine structure (XAFS) at the U L<sub>III</sub>-edge, with
the extended XAFS spectra best fitted by a model where uranyl is coordinated
by monodentate amidoxime, one chelating carboxylic acid, and two water
molecules. These results are consistent with the formation of a uranium
coordination polymer. The ultrahigh uranium uptake capacity obtained
by the bifunctional chelating ligand makes it a promising candidate
for deployment as a uranium adsorbent
Synthesis and evaluation of 5,6-disubstituted thiopyrimidine aryl aminothiazoles as inhibitors of the calcium-activated chloride channel TMEM16A/Ano1
Transmembrane protein 16A (TMEM16A), also called Ano1, is a Ca(2+) activated Cl(−) channel expressed widely in mammalian epithelia, as well as in vascular smooth muscle and some tumors and electrically excitable cells. TMEM16A inhibitors have potential utility for treatment of disorders of epithelial fluid and mucus secretion, hypertension, some cancers and other diseases. 4-Aryl-2-amino thiazole T16A(inh)-01 was previously identified by high-throughput screening. Here, a library of 47 compounds were prepared that explored the 5,6-disubstituted pyrimidine scaffold found in T16A(inh)-01. TMEM16A inhibition activity was measured using fluorescence plate reader and short-circuit current assays. We found that very little structural variation of T16A(inh)-01 was tolerated, with most compounds showing no activity at 10 µM. The most potent compound in the series, 9bo, which substitutes 4-methoxyphenyl in T16A(inh)-01 with 2-thiophene, had IC(50) ~1 µM for inhibition of TMEM16A chloride conductance
Synthesis and evaluation of 5,6-disubstituted thiopyrimidine aryl aminothiazoles as inhibitors of the calcium-activated chloride channel TMEM16A/Ano1
Transmembrane protein 16A (TMEM16A), also called Ano1, is a Ca(2+) activated Cl(-) channel expressed widely in mammalian epithelia, as well as in vascular smooth muscle and some tumors and electrically excitable cells. TMEM16A inhibitors have potential utility for treatment of disorders of epithelial fluid and mucus secretion, hypertension, some cancers and other diseases. 4-Aryl-2-amino thiazole T16Ainh-01 was previously identified by high-throughput screening. Here, a library of 47 compounds were prepared that explored the 5,6-disubstituted pyrimidine scaffold found in T16Ainh-01. TMEM16A inhibition activity was measured using fluorescence plate reader and short-circuit current assays. We found that very little structural variation of T16Ainh-01 was tolerated, with most compounds showing no activity at 10 μM. The most potent compound in the series, 9bo, which substitutes 4-methoxyphenyl in T16Ainh-01 with 2-thiophene, had IC50 ∼1 μM for inhibition of TMEM16A chloride conductance
Successful Coupling of a Bis-Amidoxime Uranophile with a Hydrophilic Backbone for Selective Uranium Sequestration
The amidoxime group
(−RNH<sub>2</sub>NOH) has long been used to extract uranium
from seawater on account of its high affinity toward uranium. The
development of tunable sorbent materials for uranium sequestration
remains a research priority as well as a significant challenge. Herein,
we report the design, synthesis, and uranium sorption properties of
bis-amidoxime-functionalized polymeric materials (BAP <b>1</b>–<b>3</b>). Bifunctional amidoxime monomers were copolymerized
with an acrylamide cross-linker to obtain bis-amidoxime incorporation
as high as 2 mmol g<sup>–1</sup> after five synthetic steps.
The resulting sorbents were able to uptake nearly 600 mg of uranium
per gram of polymer after 37 days of contact with a seawater simulant
containing 8 ppm uranium. Moreover, the polymeric materials exhibited
low vanadium uptake with a maximum capacity of 128 mg of vanadium
per gram of polymer. This computationally predicted and experimentally
realized selectivity of uranium over vanadium, nearly 5 to 1 w/w,
is one of the highest reported to date and represents an advancement
in the rational design of sorbent materials with high uptake capacity
and selectivity