bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wild boars as reservoirs of extended‐spectrum beta‐lactamase (ESBL) producing Escherichia coli of different phylogenetic groups
Authors: Poeta Patrícia , Radhouani Hajer , Pinto Luís , Martinho António , Rego Vítor , Rodrigues Rogério , Gonçalves Alexandre , Rodrigues Jorge , Estepa Vanesa , Torres Carmen , Igrejas Gilberto 
Published: October 2009

AbstractESBL‐producing E. coli isolates have been isolated from eight of seventy seven faecal samples (10.4%) of wild boars in Portugal. The ESBL types identified by PCR and sequencing were blaCTX‐M‐1 (6 isolates) and blaCTX‐M‐1 + blaTEM1‐b (2 isolates). Further resistance genes detected included tet (A) or tet (B) (in three tetracycline‐resistant isolates), aad A (in three streptomycin‐resistant isolates), cml A (in one chloramphenicol‐resistant isolate), sul 1 and/or sul 2 and/or sul 3 (in all sulfonamide‐resistant isolates). The intI 1 gene encoding class 1 integrase was detected in all ESBL‐producing E. coli isolates. One isolate also carried the intI 2 gene, encoding class 2 integrase. The ESBL‐producing E. coli isolates could be assigned to phylogenetic groups B1 (3 isolates), B2 (3 isolates) or A (2 isolates). Amino acid change in GyrA protein (Ser83Leu or Asp87Tyr) was detected in three nalidixic acid‐resistant and ciprofloxacin‐susceptible isolates. Two amino acid changes in GyrA (Ser83Leu + Asp87Asn) and one in ParC (Ser80Ile) were identified in two nalidixic acid‐ and ciprofloxacin‐resistant isolates. As evidenced by this study wild boars could be a reservoir of antimicrobial resistance genes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spontaneous and protein‐induced secretion of proteinases from Saccharomyces cerevisiae
Authors: Kurucová Anita , Farkašová Ester , Varečka Ľudovít , Šimkovič Martin 
Published: October 2009

AbstractMany fungi are capable of secreting the wide spectrum of hydrolytic enzymes. We characterized an inducible proteinase secretion in yeasts, Saccharomyces cerevisiae. The proteinase secretion by S. cerevisiae was induced in the presence of yeast extract, or of purified proteins, such as bovine serum albumin, casein, or ovalbumin, and some proteolytic activity was present also without protein inducer. We found that properties of proteinases induced under cultivation conditions were different in various aspects (temperature‐ and pH‐dependencies, substrate specificities, sensitivities to proteinase inhibitors). Proteinase activities were also characterized by gelatin zymography. Multiple proteinase bands with wide‐molecular weights (ranging from 45 to 240 kDa) were detected and patterns of proteinase bands were different. S. cerevisiae cells were able to retain the information about previous contacts with protein inducer resulting in faster and more intensive proteinase secretion response after repeated induction. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Isolation and identification of a Candida digboiensis strain from an extreme acid mine drainage of the Lignite Mine, Gujarat
Authors: Patel Mitesh J. , Tipre Devayani R. , Dave Shailesh R. 
Published: October 2009

AbstractAn extremely acidic mine drainage (AMD) water sample was collected in 1998 and 2008 from Panandhro lignite mine, Gujarat, India. The yeast isolated from this sample was identified using mini API identification system, as a member of genus Candida. The major cellular fatty acids detected by FAME from the isolate are C16:0 and C18:2 cis 9,12/C18:0α as 25.23 and 19.5%, respectively. The isolate was identified as Candida digboiensis by 18S rRNA gene sequence analysis and designated as Candida digboiensis SRDyeast1. Phylogenetic analysis using D1/D2 variable domains showed that the closest relative of this strain is Candida blankii with 3% divergence. This organism has been reported for the first time from the lignite mine AMD sample, and for cellular fatty acid analysis. This yeast is able to survive in the AMD sample preserved at 10–42 °C temperature since last 10 years along with iron oxidizing microorganisms. It can grow in the presence of 40% glucose, 10% NaCl and in the pH range of 1 to 10. The isolate is capable of producing enzymes like protease and lipase. This isolate differs from the type strain Candida digboiensis in as many as six physiological and metabolic characteristics. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection and characterization of class 1 integrons in Aeromonas spp. isolated from human diarrheic stool in Mexico
Authors: Pérez‐Valdespino Abigail , Fernández‐Rendón Elizabeth , Curiel‐Quesada Everardo 
Published: October 2009

AbstractWe determined the presence of class 1 integrons related to the acquisition of resistance to antimicrobials in Aeromonas spp. isolated from individuals with diarrhea. Species were identified as A. caviae, A. hydrophila, A. veronii and A. media using PCR‐RFLP of the 16S rDNA. Selected isolates were further characterized by ERIC‐PCR. Resistance to chloramphenicol, aztreonam, tetracycline, trimethoprim/sulfamethoxazole, nalidixic acid and streptomycin, among others, was determined using the Kirby‐Bauer method. Integrons were detected by PCR amplification of the 5′ conserved, variable, and 3′ conserved regions. Sequencing of the variable regions revealed class 1 integrons with cassettes encoding resistance to trimethoprim (dfrA12, dfrA15, dfrB4), streptomycin/spectinomycin (aadA2, aadA1), oxacillin (oxa2) and chloramphenicol (catB3, cmlA4). Others had an open reading frame (orfD) or no insert at all. To our knowledge, this is the first description of the occurrence of genes cmlA4 and dfrA15 in Aeromonas class 1 integrons. Not all the integron‐linked cassettes conferred their associated resistances, which suggests the inactivity of some cassettes. Most integrons were chromosomally located. The presence of class 1 integrons similar to those found in a wide variety of bacterial genera from different origins, including environmental and fish‐borne Aeromonas, confirms the stability and horizontal transfer of these genetic elements. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of antibiotic resistant E. coli and Enterococcus spp. in stool of healthy growing children in Portugal
Authors: Barreto Ângela , Guimarães Bruno , Radhouani Hajer , Araújo Carlos , Gonçalves Alexandre , Gaspar Eurico , Rodrigues Jorge , Igrejas Gilberto , Poeta Patrícia 
Published: October 2009

AbstractFrom stool specimens of 118 healthy children's (1–14 years) in Portugal 92 E. coli and 101 Enterococcu s spp. strains have been isolated. Almost half (40.2%) of the E. coli isolates were resistant to ampicillin, 25.0% were resistant to tetracycline and 26.1% were resistant to streptomycin. Resistance genes detected by specific PCR included blaTEM and/or blaSHV and/or blaCTX‐M (33 of 37 ampicillin and/or cefotaxime resistant isolates), tet (A) and/or tet (B) (16 of 23 tetracycline‐resistant isolates), aad A (19 of 24 streptomycin‐resistant isolates), cml A (in the two chloramphenicol‐resistant isolates), aac (3)‐II with/without aac (3)‐IV (in the four gentamicin‐resistant isolates), sul 1 and/or sul 2 and/or sul 3 (in all trimethoprim/sulfamethoxazole resistant isolates). The majority of the resistant E. coli isolates (69.1%) belonged to phylogenetic group B2. Of the enterococci isolates E. faecium (n = 53), E. faecalis (n = 41), E. hirae (n = 4) and E. durans (n = 3) more than one‐fourth (28.7%) of the isolates were resistant to tetracycline; 21.8% were resistant to erythromycin and 8.9% were resistant to kanamycin. Resistance genes detected by PCR in enterococci included aph (3)′‐IIIa (in all kanamycin‐resistant isolates), aac (6′) (in all gentamicin‐resistant isolates), tet (M) and/or tet (L) (26 of 29 tetracycline‐resistant isolates), erm (B) (17 of 22 erythromycin‐resistant isolates). This survey showed that faecal bacteria such as E. coli and enterococci of healthy growing children's could be a reservoir of antimicrobial resistance genes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elevated curdlan production by a mutant of Agrobacterium sp. ATCC 31749
Authors: West Thomas P. 
Published: October 2009

AbstractA mutant strain of the curdlan‐producing bacterium Agrobacterium sp. ATCC 31749, isolated by ethylmethane sulfonate mutagenesis and resistance to ampicillin, was capable of elevated curdlan synthesis. Using 2.5% corn syrup, glucose or maltose as a carbon source, the mutant strain was shown to produce a 1.5‐fold, 1.5‐fold or 1.5‐fold higher level of curdlan, respectively, than its parent strain after 120 h of growth. The mutant strain produced higher curdlan levels after 96 or 120 h of growth on glucose or maltose as a carbon source than it did on corn syrup. Biomass production by the mutant strain grown on the carbon sources studied was slightly elevated compared to its parent strain. It was concluded that the elevated curdlan production observed for the mutant strain grown on corn syrup or glucose was not due to an increase in biomass production. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interference of chromium with biological systems in yeasts and fungi: a review
Authors: Poljsak Borut , Pócsi István , Raspor Peter , Pesti Miklós 
Published: October 2009

AbstractThis paper deals with the interactions of chromium (Cr) with biological systems, focusing in particular on yeasts and fungi. These interactions are analysed with primarily regard to biochemical functions, but higher levels of organization are also considered. Thus, the morphological and cytological characteristics of selected microorganisms in response to exposure to chromium ions are evaluated. The different oxidation states of chromium and reactive oxygen species (ROS) generated in redox reactions with chromium ions are presented and characterized. The interactions of the most exposed subcellular structures, including the cell wall, plasma membrane and nuclei, have been deeply investigated in recent years, for two major reasons. The first is the toxicity of chromium ions and their strong impact on the metabolism of many species, ranging from microbes to humans. The second is the still disputed usefulness of chromium ions, and in particular trivalent chromium, in the glucose and fat metabolisms. Chromium pollution is still an important issue in many regions of the world, and various solutions have been proposed for the bioremediation of soil and water with selected microbial species. Yeasts and especially moulds have been most widely investigated from this aspect, and the biosorption and bioaccumulation of chromium for bioremediation purposes have been demonstrated. Accordingly, the mechanisms of chromium tolerance or resistance of selected microbes are of particular importance in both bioremediation and waste water treatment technologies. The mechanisms of chromium toxicity and detoxification have been studied extensively in yeasts and fungi, and some promising results have emerged in this area. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Corrosion resistance of the anti‐sulfide steel in the CO2/H2S containing solutions
Authors: Bai Z. Q. , Yin Z. F. , Wei D. , Wang X. F. , Yin C. X. 
Published: October 2009

AbstractThe present work primarily investigates the corrosion characterization of the common P110 steel and the anti‐sulfide P110SS steel in CO2‐containing solution with or without hydrosulfuric acid (H2S) at 70 °C. The electrochemical techniques such as potentiodynamic polarization sweep and electrochemical impedance spectroscopy (EIS) were used to disclose the differences of the corrosion mechanisms between both P110 and P110SS steels in CO2‐containing solution with various additions of H2S. The EIS data fitted by ZsimpWin software were analyzed and discussed. The experimental results indicated that H2S could accelerate and also inhibit the corrosion attack according to the changes of corrosive environments.
The effect of calcination on the corrosion performance of TiO2 sol–gel coatings doped with benzotriazole on steel CK45
Authors: Madani S. M. , Ehteshamzadeh M. , Rafsanjani H. H. , Mansoori S. S. 
Published: October 2009

AbstractSol–gel method under dip coating process and tetra‐n‐butyle orthotitanate as precursor were used to produce titanium oxide coating on steel CK45. The effect of calcination at 400 °C, after drying at 120 °C, on the morphology and corrosion performance of the coatings was investigated. Benzotriazole (BTA) as an inhibitor was doped on titanium oxide coatings to improve corrosion performance of the coatings as well as its self‐healing properties. The morphology and structure of the coatings were studied by X‐ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X‐ray spectroscopy (EDS) techniques. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were used to study the corrosion behavior of the coatings. The results revealed that after calcination the dominant crystalline phase was anatase. The results obtained from potentiodynamic polarization curves and electrochemical impedance spectra showed that the calcinated and doped with BTA coatings possessed higher corrosion resistance than non‐calcinated although doped with BTA coatings.
Effect of the metallic substrate and zinc layer on the atmospheric corrosion resistance of phosphatized and painted electrogalvanized steels
Authors: Alvarenga E. A. , Moreira J. G. , Buono V. T. L. , Lins V. F. C. 
Published: October 2009

AbstractIn this work, the influence of the metallic substrate and zinc layer on the atmospheric corrosion resistance of phosphatized and painted electrogalvanized steels was evaluated. For this purpose two types of electrogalvanized steels were used, one with drawing quality carbon steel as metallic substrate, and the other one with a substrate of Ni–Cu–Cr added carbon steel. The corrosion resistance was determined by accelerated and non‐accelerated corrosion tests, using cyclic test chambers and field tests in industrial and marine atmosphere. The mean corrosion advance and the maximum corrosion penetration of samples were measured using image analysis techniques. The study showed that the substrate and zinc layer mass play a decisive role on the atmospheric corrosion resistance of the phosphatized and painted electrogalvanized steels. It was also verified that it is possible to use smaller zinc layer masses without compromising the corrosion resistance of the material, provided that the metallic substrate has characteristics of atmospheric corrosion resistance, thus contributing to the improvement of the zinc coated steels.
DFT theoretical studies of antipyrine Schiff bases as corrosion inhibitors
Authors: Issa R. M. , Awad M. K. , Atlam F. M. 
Published: October 2009

AbstractThe anti‐corrosive properties of some antipyrine Schiff bases (benzylidine amino)antipyrine (a), 4‐hydroxy 3‐(benzylidine amino)antipyrine (b), 2‐hydroxy 3‐(benzylidine amino)antipyrine (c), and 2‐hydroxy 3‐(naphthylidine amino)antipyrine (d) are studied using density functional theory at the B3LYP/6‐31G level. The computational calculations are performed to find a relation between their electronic and structural properties and the inhibition efficiency. The calculated quantum chemical parameters correlated to the inhibition efficiency are, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), the separation energy (ΔE), the dipole moment (µ), the softness (σ), the total negative charge on the whole molecule (TNC), the total charge on the azomethine moiety, the molecular volume (Vi), and the total energy (TE). A good correlation between the quantum chemical parameters and the experimental inhibition efficiency is found.
Early stages of copper corrosion behaviour in a Tunisian soil
Authors: Souissi N. , Triki E. 
Published: October 2009

AbstractThe early stages of copper corrosion in a Tunisian soil were studied using mass loss, surface analysis (optical microscopy, visible spectroscopy, IRTF and atomic force microscopy) and electrochemical characterizations (polarization curves and cyclic voltammetry). The corrosion rate dependence with immersion time was Δm = atb. Two behaviours for the material surface were evidenced when varying the soil concentration and temperature. Then, the apparent kinetic constant, the soil reaction order and the apparent activation energy were calculated. Analytical and electrochemical characterizations showed that a rough patina layer was build up as a result of the interaction between soil and copper.
Microstructural properties of the bulk matrix and the steel/cement paste interface in reinforced concrete, maintained in conditions of corrosion and cathodic protection
Authors: Koleva D. A. , Guo Z. , van Breugel K. , de Wit J. H. W. 
Published: October 2009

AbstractAlthough rarely considered, especially within the investigation of steel corrosion phenomena or electrochemical protection techniques in reinforced concrete structures, the concrete bulk matrix has a significant contribution in the global performance of the system “reinforced concrete.” This is especially the case when chloride‐induced corrosion or electrical current flow [as within impressed current cathodic protection (CP)] are involved. In the latter cases, the concrete bulk matrix undergoes significant alterations in chemical composition, electrical properties, and microstructures, thus influencing the overall performance of the system. This work reports on the microstructural investigation of the bulk concrete matrix and the steel/cement paste interface in reinforced concrete, previously subjected to corrosion and CP for 460 days. The emphasis hereby is to evaluate the altered structural properties, i.e., porosity, pore size, permeability of the bulk cement matrix, and the steel/cement paste interface (translated to bond strength) as a result of chloride‐induced corrosion and two types of CP (conventional and pulse), compared to control (non‐corroding, non‐protected) conditions. The research revealed a major contribution and close dependence of all microlevel interfaces on the global performance of reinforced concrete. The electrical current flow (as in CP applications) was found to bring about unfavorable modifications to the material structure, both in the bulk matrix (reducing porosity) and at the steel/cement paste interface (enlarging interfacial gaps). The derived microstructural parameters show that the conventional CP leads to a higher level of structural heterogeneity, whereas the pulse CP exerts minimal or no effects, maintaining the material properties close to the reference (control) conditions, the underlying mechanism being a more homogeneous material microstructure.
Corrosion performance of Zn–Al–Mg coatings in open and confined zones in conditions simulating automotive applications
Authors: Prosek T. , Larché N. , Vlot M. , Goodwin F. , Thierry D. 
Published: October 2009

AbstractPanels coated by hot dipping with zinc (HDG), Zn–5Al (Galfan) and Zn–1.5Al–1.5Mg coatings at different thicknesses were phosphated and painted on an industrial line. Crevice panels with non‐painted bare parts modelling conditions in hem flanges, reference panels with open surfaces and formed non‐painted panels were exposed to a cyclic accelerated automotive test. Zn–Al–Mg coatings with the thickness of 10 µm provided similar or even better protection than HDG and Galfan at 20 µm in both confined and open configurations. In comparison to 10‐µm HDG, the Zn–Al–Mg coating delayed red rust appearance in crevices by a factor of 2 and the maximal depth of corrosion in the steel substrate was by 42% lower. Confined areas were more corroded than open surfaces. For HDG, the time to red rust appearance dropped by 50–75%, corrosion attack in steel was from 3.5 to 7 times deeper and mass gain was about 2.3 times higher in crevices than on open surfaces. Corrosion of Zn–Al–Mg may be more affected by local environmental conditions created by the crevice configuration than for HDG. Red rust appearance on formed panels of 20‐µm Galfan, 7‐, 10‐ and 14‐µm Zn–Al–Mg was delayed to 10‐µm HDG by a factor of 2.8, 3.5, 3.8 and >4.5, respectively. No adverse effect of forming was noticed. The results indicate that 2‐ to 3‐fold reduction of the coating thickness for Zn–Al–Mg alloy coatings in comparison to traditional HDG may be possible without compromising the corrosion performance.
An Aqueous, Electrolyte‐Type, Rechargeable Device Utilizing a Hydrophilic Radical Polymer‐Cathode
Authors: Koshika Kenichiroh , Sano Naoki , Oyaizu Kenichi , Nishide Hiroyuki 
Published: October 2009

AbstractA hydrophilic poly(vinyl ether)‐backbone polymer bearing a pendant TEMPO radical, poly(2,2,6,6‐tetramethylpiperidinyloxy‐4‐yl vinyl ether) (PTVE), was designed as a cathode‐active material, which displays a reversible one‐electron redox capability, even in an aqueous electrolyte. The PTVE layer coated on a current collector demonstrated a rapid charging‐discharging rate based on the combination of the redox‐active nitroxide radicals built into the hydrophilic polymer and the aqueous electrolyte that possessed a high electrical conductivity. A test cell fabricated with a PTVE cathode, a zinc anode, and an aqueous electrolyte gave an output voltage of 1.7 V and showed the ability to be recharged more than 500 times rechargeability.magnified image
Naringin inhibits matrix metalloproteinase‐9 expression and AKT phosphorylation in tumor necrosis factor‐α‐induced vascular smooth muscle cells
Authors: Lee Eo‐Jin , Kim Dong‐Il , Kim Wun‐Jae , Moon Sung‐Kwon 
Published: October 2009

AbstractCitrus fruits are high in naringin, which has a beneficial effect on cardiovascular diseases. However, the matrix metalloproteinase‐9 (MMP‐9) regulation involved in cell migration and invasion remains to be identified. Naringin inhibited tumor necrosis factor‐α (TNF‐α)‐induced expression of MMP‐9, under 10–25 μM concentration conditions in vascular smooth muscle cells (VSMC). The TNF‐α‐induced invasion and migration of VSMC were inhibited by naringin. Furthermore, naringin suppressed TNF‐α‐mediated release of interleukin‐6 and ‐8 (IL‐6 and IL‐8). However, naringin (10–25 μM) treatment of VSMC in the presence of TNF‐α did not affect cell growth and apoptosis. In additional experiments, naringin reduced the transcriptional activity of activator protein‐1 and nuclear factor kappaB (NF‐κB), which are two important nuclear transcription factors that are involved in MMP‐9 expression. Also, naringin treatment blocked PI3K/AKT/mTOR/p70S6K pathway in TNF‐α‐induced VSMC. Treatment of aglycone naringenin (10–25 μM) had same effect on the levels of MMP‐9 expression, invasion, migration, and AKT phosphorylation in TNF‐α‐induced VSMC, compared with naringin treatment. These results suggest that naringin represses PI3K/AKT/mTOR/p70S6K pathway, invasion and migration, and subsequently suppresses MMP‐9 expression through the transcription factors NF‐κB and activator protein‐1 in TNF‐α‐induced VSMC. These novel findings provide a theoretical basis for the preventive use of naringin for atherosclerosis disease.