bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and characterization of PMAA/MWCNTs nanohybrid hydrogels with improved mechanical properties
Authors: Luo Yan‐Ling , Xu Feng , Feng Qiang‐Suo , Chen Ya‐Shao , Ma Chao
Published: October 2009

A novel nanohybrid hydrogel was in situ prepared by means of a free radical crosslinking polymerization route of methacrylic acid in the presence of multi‐walled carbon nanotubes (MWCNTs). The structural and morphological characterizations revealed that poly(methacrylic acid) networks (PMAA) closely covered the MWCNTs, and a MWCNT‐well‐dispersed nanohybrid hydrogel was formed. The addition of MWCNTs strikingly improved pH response and mechanical properties, depending on the component ratios and particle sizes of MWCNTs as well as crosslinker concentrations. The swelling rate was obviously faster than that of the pure PMAA hydrogel. The hydrophilic nature of polyelectrolytes, the capillarity effect, cation‐π or charge‐transfer interaction and hydrogen bonds, as well as a subtle balance among these interactions were adopted to interpret the above swelling behavior. Load transfer to the MWCNTs in the networks played important part in compression mechanical improvements. MTT assays were adopted to evaluate the cytocompatibility of the developed biomaterials. This smart hydrogel is expected to be used as potential candidate for specific biological applications. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2010
Corono‐apical leakage of various root filling materials using two different penetration models—A 3‐month study
Authors: Kececi Ayse Diljin , Kaya Bulem Ureyen , Belli Sema
Published: October 2009

The purpose of this study was to analyze the sealing ability of various filling combinations in a 90 days period using fluid transport and glucose penetration models. Premolars (n = 108) were filled with either gutta‐percha (groups 1–4) or Resilon (groups 5–8) core materials combined with AH Plus (groups 1, 3, 5, 7) or Epiphany (groups 2, 4, 6, 8) sealers by using cold lateral compaction (groups 1, 2, groups 5, 6) or System B with Obtura II (groups 3, 4, groups 7, 8). The sealing ability of each sample was evaluated through glucose and fluid penetration models. Penetration values of 90 days were statistically analyzed with three‐way analysis of variance (ANOVA)and Duncan's Multiple Range tests (p < 0.05). No significant differences were found among the penetration values when the fluid filtration model was used (p > 0.05). On the contrary, statistically significant differences were obtained among the groups with the glucose penetration model (p < 0.05). AH Plus/Resilon/cold lateral compaction group had better sealing ability than the other combinations tested with the glucose penetration model. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2010
Effect of adipic dihydrazide modification on the performance of collagen/hyaluronic acid scaffold
Authors: Zhang Ling , Xiao Yumei , Jiang Bo , Fan Hongsong , Zhang Xingdong
Published: October 2009

Collagen and hydrazide‐functionalized hyaluronic acid derivatives were hybridized by gelating and genipin crosslinking to form composite hydrogel. The study contributed to the understanding of the effects of adipic dihydrazide modification on the physicochemical and biological properties of the collagen/hyaluronic acid scaffold. The investigation included morphology observation, mechanical measurement, swelling evaluation, and collagenase degradation. The results revealed that the stability of composites was increased through adipic dihydrazide modification and genipin crosslinking. The improved biocompatibility and retention of hyaluronic acid made the composite material more favorable to chondrocytes growing, suggesting the prepared scaffold might be high potential for chondrogenesis. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Dental glass‐reinforced composite for caries inhibition: Calcium phosphate ion release and mechanical properties
Authors: Xu Hockin H. K. , Moreau Jennifer L.
Published: October 2009

The two main challenges facing dental composite restorations are secondary caries and bulk fracture. Previous studies developed whisker‐reinforced Ca‐PO4 composites that were relatively opaque. The objective of this study was to develop an esthetic glass particle‐reinforced, photo‐cured calcium phosphate composite. Tetracalcium phosphate (TTCP) particles were incorporated into a resin for Ca and PO4 release, while glass particles provided reinforcement. Ion release and mechanical properties were measured after immersion in solutions with pH of 7, 5.5, and 4. For the composite containing 40% mass fraction of TTCP, incorporating glass fillers increased the strength (p < 0.05). Flexural strength (Mean ± SD; n = 6) at 30% glass was 99 ± 18 MPa, higher than 54 ± 20 MPa at 0% glass (p < 0.05). Elastic modulus was 11 GPa at 30% glass, compared to 2 GPa without glass. At 28 days, the released Ca ion concentration was 4.61 ± 0.18 mmol/L at pH of 4, much higher than 1.14 ± 0.07 at pH of 5.5, and 0.27 ± 0.01 at pH of 7 (p < 0.05). PO4 release was also dramatically increased at cariogenic, acidic pH. The TTCP‐glass composite had strength 2–3 fold that of a resin‐modified glass ionomer control. In conclusion, the photo‐cured TTCP‐glass composite was “smart” and substantially increased the Ca and PO4 release when the pH was reduced from neutral to a cariogenic pH of 4, when these ions are most needed to inhibit tooth caries. Its mechanical properties were significantly higher than previous Ca, PO4, and fluoride releasing restoratives. Hence, the photo‐cured TTCP‐glass composite may have potential to provide the necessary combination of load‐bearing and caries‐inhibiting capabilities. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Domain–ligand mapping for enzymes
Authors: Bashton Matthew , Thornton Janet M
Published: October 2009

In this paper we provide an overview of our current knowledge of the mapping between small molecule ligands and protein domains. We give an overview of the present data resources available on the Web, which provide information about protein–ligand interactions, as well as discussing our own PROCOGNATE database. We present an update of ligand binding in large protein superfamilies and identify those ligands most frequently utilized by nature. Finally we discuss potential uses for this type of data. Copyright © 2009 John Wiley & Sons, Ltd.
Rapid and sensitive detection of Mollicutes in cell culture by polymerase chain reaction
Authors: Shahhosseiny Mohammad Hassan , Hosseiny Zahra , Khoramkhorshid Hamid Reza , Azari Shahram , Shokrgozar Mohammad Ali
Published: October 2009

Infections with Mollicutes species (such as Mycoplasma, Acholeplasma, and Ureaplasma) can induce a variety of problems in living organisms and laboratory cell cultures. Therefore, it is necessary to establish a routine diagnostic protocol for Mycoplasma infection in order to ensure reliable research results, as well as the safety of commercial biological products. For that purpose a novel PCR‐based procedure using specific designed primers complementary to 16S rRNA genome region of mollicute species was evaluated. PCR was optimized and sensitivity and specificity was evaluated by defined cell count concentrations (2‐31250 CFU/ml) of different strains of Mycoplasma, Acholeplasma and Ureaplasma. Amplicon (272 bp) was cloned by PCR‐cloning and sequenced by dideoxy chain termination. PCR, was found to be able to detect 10 copies of mollicute target DNA. No cross‐reactivity with genomic DNA of non‐mollicute bacteria or human cell lines was observed. Forty seven human and animal cell lines were evaluated for mollicute contamination. Twenty five cell lines (53%) were correctly identified as contaminated by this molecular approach. The results of this study demonstrated that this PCR‐based method is not only fast and reproducible, but also highly sensitive and specific for detecting contaminant mycoplasmas in cell cultures. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient inhibition of human cytomegalovirus UL122 gene expression in cell by small interfering RNAs
Authors: Duan Qun‐Jun , Tao Ran , Hu Miao‐Feng , Shang Shi‐Qiang
Published: October 2009

In order to develop a gene therapy to human cytomegalovirus (HCMV), RNA interference (RNAi) was employed to inhibit the expression of HCMV UL122 gene in vitro. Recombinant vector pUL122‐EGFP, which expressed UL122‐EGFP fusion protein, and recombinant vectors psi122‐1, psi122‐2 and psi122‐3, which expressed small interfering RNAs (siRNAs) targeted to UL122 were contransfected into AD293 cells. The fluorescence signal of pUL122‐EGFP was greatly suppressed by psi122‐1 and psi122‐2, with an inhibitory rate of 82.0% ± 1.0% and 79.5% ± 2.5%, respectively. The mRNA of pUL122‐EGFP of the cells transfected with psi122‐1 and psi122‐2 was decreased 97.3% ± 0.6% and 98.0% ± 0.1%, respectively. Vector psi122‐3 showed a slightly low suppression rate. Therefore, it may be concluded that plasmids encoding siRNAs targeted to UL122 is able to in vitro reduce markedly the expression of UL122‐EGFP. And it is very likely that the psi122‐1 and psi122‐2 are potentially efficacious siRNAs in the gene therapy of HCMV infection in vivo, in which further investigations are required. This study is expected to greatly facilitate the use of the RNAi technology for the anti‐HCMV studies. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
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

ESBL‐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

Many 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

An 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

We 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

From 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

A 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

This 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

The 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

Sol–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

In 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

The 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

The 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

Although 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

Panels 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

A 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

Citrus 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.
Influence of thermal processing on IgE reactivity to lentil and chickpea proteins
Authors: Cuadrado Carmen , Cabanillas Beatriz , Pedrosa Mercedes M. , Varela Alejandro , Guillamón Eva , Muzquiz Mercedes , Crespo Jesús F. , Rodriguez Julia , Burbano Carmen
Published: October 2009

In the last years, legume proteins are gaining importance as food ingredients because of their nutraceutical properties. However, legumes are also considered relevant in the development of food allergies through ingestion. Peanuts and soybeans are important food allergens in Western countries, while lentil and chickpea allergy are more relevant in the Mediterranean area. Information about the effects of thermal‐processing procedures at various temperatures and conditions is scarce; therefore, the effect of these procedures on legume allergenic properties is not defined so far. The SDS‐PAGE and IgE‐immunoblotting patterns of chickpeas and lentils were analyzed before and after boiling (up to 60 min) and autoclaving (1.2 and 2.6 atm, up to 30 min). The results indicated that some of these treatments reduce IgE binding to lentil and chickpea, the most important being harsh autoclaving. However, several extremely resistant immunoreactive proteins still remained in these legumes even after this extreme treatment.
Four selenoproteins, protein biosynthesis, and Wnt signalling are particularly sensitive to limited selenium intake in mouse colon
Authors: Kipp Anna , Banning Antje , van Schothorst Evert M. , Méplan Catherine , Schomburg Lutz , Evelo Chris , Coort Susan , Gaj Stan , Keijer Jaap , Hesketh John , Brigelius‐Flohé Regina
Published: October 2009

Selenium is an essential micronutrient. Its recommended daily allowance is not attained by a significant proportion of the population in many countries and its intake has been suggested to affect colorectal carcinogenesis. Therefore, microarrays were used to determine how both selenoprotein and global gene expression patterns in the mouse colon were affected by marginal selenium deficiency comparable to variations in human dietary intakes. Two groups of 12 mice each were fed a selenium‐deficient (0.086 mg Se/kg) or a selenium‐adequate (0.15 mg Se/kg) diet. After 6 wk, plasma selenium level, liver, and colon glutathione peroxidase (GPx) activity in the deficient group was 12, 34, and 50%, respectively, of that of the adequate group. Differential gene expression was analysed with mouse 44K whole genome microarrays. Pathway analysis by GenMAPP identified the protein biosynthesis pathway as most significantly affected, followed by inflammation, Delta‐Notch and Wnt pathways. Selected gene expression changes were confirmed by quantitative real‐time PCR. GPx1 and the selenoproteins W, H, and M, responded significantly to selenium intake making them candidates as biomarkers for selenium status. Thus, feeding a marginal selenium‐deficient diet resulted in distinct changes in global gene expression in the mouse colon. Modulation of cancer‐related pathways may contribute to the higher susceptibility to colon carcinogenesis in low selenium status.
Variation in the human lipidome associated with coffee consumption as revealed by quantitative targeted metabolomics
Authors: Altmaier Elisabeth , Kastenmüller Gabi , Römisch‐Margl Werner , Thorand Barbara , Weinberger Klaus M. , Adamski Jerzy , Illig Thomas , Döring Angela , Suhre Karsten
Published: October 2009

The effect of coffee consumption on human health is still discussed controversially. Here, we report results from a metabolomics study of coffee consumption, where we measured 363 metabolites in blood serum of 284 male participants of the Cooperative Health Research in the Region of Augsburg study population, aged between 55 and 79 years. A statistical analysis of the association of metabolite concentrations and the number of cups of coffee consumed per day showed that coffee intake is positively associated with two classes of sphingomyelins, one containing a hydroxy‐group (SM(OH)) and the other having an additional carboxy‐group (SM(OH,COOH)). In contrast, long‐ and medium‐chain acylcarnitines were found to decrease with increasing coffee consumption. It is noteworthy that the concentration of total cholesterol also rises with an increased coffee intake in this study group. The association observed here between these hydroxylated and carboxylated sphingolipid species and coffee intake may be induced by changes in the cholesterol levels. Alternatively, these molecules may act as scavengers of oxidative species, which decrease with higher coffee intake. In summary, we demonstrate strong positive associations between coffee consumption and two classes of sphingomyelins and a negative association between coffee consumption and long‐ and medium‐chain acylcarnitines.
Optimizing assignment of Tomahawk cruise missile missions to firing units
Authors: Newman Alexandra M. , Rosenthal Richard E. , Salmerón Javier , Brown Gerald G. , Price Wilson , Rowe Anton , Fennemore Charles F. , Taft Robert L.
Published: October 2009

The Tomahawk land‐attack cruise missile can be launched from a ship or submarine, and can deliver its warhead precisely to a target at long range. There are several variants of the Tomahawk missile, each with specialized capabilities. For each Tomahawk Missile Sequence Number (MSN) task (i.e., mission), the Tomahawk missile variants can be ranked with respect to their ability and cost effectiveness to perform that task. A given land attack strike order may involve a large number of Tomahawk missiles and numerous Tomahawk launch platforms. Operational planners select, in real time, feasible launch platforms to execute Tomahawk taskings. The Tomahawk tasking in a strike order includes not only primary assignments but also backup assignments. On board each launch platform, the precise allocation of specific Tomahawk missiles to the Tomahawk MSN task assigned is optimized with a model described here. We help naval operational planners select, in real time, appropriate feasible launch platforms to fulfill the Tomahawk tasking in a strike order. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 58: 281–294, 2011
On online bin packing with LIB constraints
Authors: Epstein Leah
Published: October 2009

In many applications of packing, the location of small items below large items, inside the packed boxes, is forbidden. We consider a variant of the classic online one‐dimensional bin packing, in which items allocated to each bin are packed there in the order of arrival, satisfying the condition above. This variant is called online bin packing problem with LIB (larger item in the bottom) constraints. We give an improved analysis of First Fit showing that its competitive ratio is at most
$ {5 \over 2} = 2.5$, and design a lower bound of 2 on the competitive ratio of any online algorithm. In addition, we study the competitive ratio of First Fit as a function of an upper bound $ {1 \over d} $
(where d is a positive integer) on the item sizes. Our upper bound on the competitive ratio of First Fit tends to 2 as d grows, whereas the lower bound of two holds for any value of d. Finally, we consider several natural and well known algorithms, namely, Best Fit, Worst Fit, Almost Worst Fit, and Harmonic, and show that none of them has a finite competitive ratio for the problem. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009
Methoxy poly(ethylene glycol)‐b‐poly(octadecanoic anhydride)‐b‐methoxy poly(ethylene glycol) amphiphilic triblock copolymer nanoparticles as delivery vehicles for paclitaxel
Authors: Xing Jinfeng , Deng Liandong , Xie Chaopeng , Xiao Li , Zhai Yinglei , Jin Fengmin , Li Yimei , Dong Anjie
Published: October 2009

A series of amphiphilic triblock copolymers, methoxy poly(ethylene glycol)‐b‐poly(octadecanoic anhydride)‐b‐methoxy poly(ethylene glycol) (mPEG‐b‐POA‐b‐mPEG), were prepared via melt polycondensation of methoxy poly(ethylene glycol) (mPEG) and poly(octadecanoic anhydride) (POA). mPEG‐b‐POA‐b‐mPEG were characterized by FTIR, 1H‐NMR, GPC, DSC, and XRD. Drug‐loaded mPEG‐b‐POA‐b‐mPEG nanoparticles (NPs) with spherical morphology and narrow size polydispersity index were prepared by nanoprecipitation technique with paclitaxel as the model drug. In vitro release behaviors of drug‐loaded NPs present that the biphasic process and the release mechanism of each phase are zero order drug releases. According to this study, mPEG‐b‐POA‐b‐mPEG NPs could serve as suitable delivery agents for paclitaxel and other hydrophobic drugs. Copyright © 2009 John Wiley & Sons, Ltd.
Simultaneous extraction of nucleic acids and proteins from tissue specimens by ultracentrifugation: A protocol using the high‐salt protein fraction for quantitative proteome analysis
Authors: Grzendowski Michael , Riemenschneider Markus J. , Hawranke Eva , Stefanski Anja , Meyer Helmut E. , Reifenberger Guido , Stühler Kai
Published: October 2009

Comprehensive molecular profiling of human tumor tissue specimens at the DNA, mRNA and protein level is often obstructed by a limited amount of available material. Homogenization of frozen tissue samples in guanidine isothiocyanate followed by ultracentrifugation over cesium chloride allows the simultaneous extraction of high‐molecular weight DNA and RNA. Here, we present a protocol for quantitative proteome analysis using the high‐salt protein fraction obtained as supernatant after ultracentrifugation for nucleic acid extraction. We applied this method to extracts from primary human brain tumors and demonstrate its successful application for protein expression profiling in these tumors using 2‐D DIGE, MS and Western blotting.
Proteomic analysis of Arabidopsis halleri shoots in response to the heavy metals cadmium and zinc and rhizosphere microorganisms
Authors: Farinati Silvia , DalCorso Giovanni , Bona Elisa , Corbella Michela , Lampis Silvia , Cecconi Daniela , Polati Rita , Berta Graziella , Vallini Giovanni , Furini Antonella
Published: October 2009

Arabidopsis halleri has the rare ability to colonize heavy metal‐polluted sites and is an emerging model for research on adaptation and metal hyperaccumulation. The aim of this study was to analyze the effect of plant–microbe interaction on the accumulation of cadmium (Cd) and zinc (Zn) in shoots of an ecotype of A. halleri grown in heavy metal‐contaminated soil and to compare the shoot proteome of plants grown solely in the presence of Cd and Zn or in the presence of these two metals and the autochthonous soil rhizosphere‐derived microorganisms. The results of this analysis emphasized the role of plant–microbe interaction in shoot metal accumulation. Differences in protein expression pattern, identified by a proteomic approach involving 2‐DE and MS, indicated a general upregulation of photosynthesis‐related proteins in plants exposed to metals and to metals plus microorganisms, suggesting that metal accumulation in shoots is an energy‐demanding process. The analysis also showed that proteins involved in plant defense mechanisms were downregulated indicating that heavy metals accumulation in leaves supplies a protection system and highlights a cross‐talk between heavy metal signaling and defense signaling.
Proteomic analysis of the secretome of human umbilical vein endothelial cells using a combination of free‐flow electrophoresis and nanoflow LC‐MS/MS
Authors: Tunica David Guillen , Yin Xiaoke , Sidibe Anissa , Stegemann Christin , Nissum Mikkel , Zeng Lingfang , Brunet Merce , Mayr Manuel
Published: October 2009

Human umbilical vein endothelial cells are the most widely used in vitro model for endothelial cells. Their secreted proteins, however, have not been comprehensively analysed so far. In this study, we accomplished to map the secretome of human umbilical vein endothelial cells by combining free‐flow electrophoresis with nanoflow LC‐MS/MS. This comprehensive analysis provides a basis for future comparative studies of protein secretion by endothelial cells in response to cardiovascular risk factors and is available on our website http://www.vascular‐proteomics.com.
Can ultrasonic energy efficiently speed 18O‐labeling of proteins?
Authors: Carreira Ricardo J. , Lodeiro Carlos , Diniz Mario S. , Moura Isabel , Capelo José L.
Published: October 2009

We report in this work on the robustness of ultrasonic energy as a tool to speed the isotopic labeling of proteins using the 18O‐decoupling procedure. The first part of the decoupling procedure, comprising protein denaturation, reduction, alkylation and digestion, is done in 8 min under the effects of an ultrasonic field whilst the second part, the isotopic labeling, was assayed with and without the use of ultrasonic energy. Our results clearly demonstrate that the 18O‐isotopic labeling in a decoupling procedure cannot be accelerated using an ultrasonic field.
ExoCarta: A compendium of exosomal proteins and RNA
Authors: Mathivanan Suresh , Simpson Richard J.
Published: October 2009

Exosomes, membrane microvesicles (40–100 nm) secreted by most cell types, can be isolated in several ways while characterizing them is heavily based on electron microscopy and, most importantly, the identification of exosome marker proteins. Researchers rely on the identification of certain exosomal marker proteins including Alix, CD9 and CD63 to confirm the presence of exosomes in their preparations. An evolutionary‐conserved set of protein molecules have been identified in most exosomes studied to date. However, with the complexity of tissue/cell type‐specific proteins being incorporated in the exosomes, some of these so‐called exosomal markers are not always present in all the exosomes. The presence of tissue/cell type‐specific proteins in exosomes allows researchers to isolate them using immunoaffinity capture methods. A compendium for exosomal proteomes will aid researchers in identifying proteins that were more commonly found in various exosomes (exosome markers) and those that are specific to certain tissue/cell type‐derived exosomes. Here, we describe ExoCarta, a compendium for proteins and RNA molecules identified in exosomes. ExoCarta is first of its kind and the resource is freely available to the scientific community through the web (http://exocarta.ludwig.edu.au). We believe that this community resource will be of great biological importance for any future exosome analyses.
Hydrogels: From soft contact lenses and implants to self‐assembled nanomaterials
Authors: Kopecek Jindrich
Published: October 2009

Hydrogels were the first biomaterials designed for clinical use. Their discovery and applications as soft contact lenses and implants are presented. This early hydrogel research served as a foundation for the expansion of biomedical polymers research into new directions: design of stimuli sensitive hydrogels that abruptly change their properties upon application of an external stimulus (pH, temperature, solvent, electrical field, biorecognition) and hydrogels as carriers for the delivery of drugs, peptides, and proteins. Finally, pathways to self‐assembly of block and graft copolymers into hydrogels of precise 3D structures are introduced. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5929–5946, 2009
Star polymers with POSS via azide–alkyne click reaction
Authors: Gungor Eda , Bilir Cigdem , Durmaz Hakan , Hizal Gurkan , Tunca Umit
Published: October 2009

Azidopropyl‐heptaisobutyl‐substituted polyhedral oligomeric silsesquioxane (POSS‐N3) was reacted with 1,1,1‐tris[4‐(2‐propynyloxy)phenyl]‐ethane (1) and poly(ethylene glycol) (PEG)‐b‐poly(methyl methacrylate) (PMMA) copolymer with alkyne at its center (PEG‐PMMA‐alkyne) affording the first time synthesis of 3‐arm star POSS and PEG‐PMMA‐POSS 3‐miktoarm star terpolymer, respectively, in the presence of CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as catalyst and N,N‐dimethylformamide/tetrahydrofuran as solvent at room temperature. The precursors and the target star polymers were characterized comprehensively by 1H NMR, GPC, and DSC. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5947–5953, 2009