bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constitutional telomerase mutations are genetic risk factors for cirrhosis
Authors: Calado Rodrigo T. , Brudno Jennifer , Mehta Paulomi , Kovacs Joseph J. , Wu Colin , Zago Marco A. , Chanock Stephen J. , Boyer Thomas D. , Young Neal S. 
Published: January 2011

Abstract

Some patients with liver disease progress to cirrhosis, but the risk factors for cirrhosis development are unknown. Dyskeratosis congenita, an inherited bone marrow failure syndrome associated with mucocutaneous anomalies, pulmonary fibrosis, and cirrhosis, is caused by germline mutations of genes in the telomerase complex. We examined whether telomerase mutations also occurred in sporadic cirrhosis. In all, 134 patients with cirrhosis of common etiologies treated at the Liver Research Institute, University of Arizona, between May 2008 and July 2009, and 528 healthy subjects were screened for variation in the

TERT

and

TERC

genes by direct sequencing; an additional 1,472 controls were examined for the most common genetic variation observed in patients. Telomere length of leukocytes was measured by quantitative polymerase chain reaction. Functional effects of genetic changes were assessed by transfection of mutation-containing vectors into telomerase-deficient cell lines, and telomerase activity was measured in cell lysates. Nine of the 134 patients with cirrhosis (7%) carried a missense variant in

TERT

, resulting in a cumulative carrier frequency significantly higher than in controls (

P

= 0.0009). One patient was homozygous and eight were heterozygous. The allele frequency for the most common missense

TERT

variant was significantly higher in patients with cirrhosis (2.6%) than in 2,000 controls (0.7%;

P

= 0.0011). One additional patient carried a

TERC

mutation. The mean telomere length of leukocytes in patients with cirrhosis, including six mutant cases, was shorter than in age-matched controls (

P

= 0.0004).

Conclusion:

Most

TERT

gene variants reduced telomerase enzymatic activity

in vitro

. Loss-of-function telomerase gene variants associated with short telomeres are risk factors for sporadic cirrhosis. (Hepatology 2011;)
Biodegradable Elastomers for Tissue Engineering and Cell–Biomaterial Interactions
Authors: Bettinger Christopher J. 
Published: January 2011

AbstractSynthetic biomaterials serve as a cornerstone in the development of clinically focused regenerative medicine therapies that aim to reduce suffering and prolong life. Recent improvements in biodegradable elastomeric materials utilize natural extracellular matrix proteins as inspiration to yield a new class of materials with superior degradation kinetics, desirable biocompatibility profiles, and mechanical properties that closely match those of soft tissues. This review describes several classes of synthetic biodegradable elastomers and associated fabrication techniques that are relevant to scaffold development. The application of these materials to select tissue engineering models is also discussed. magnified image
Mechanistic Considerations on Contact‐Active Antimicrobial Surfaces with Controlled Functional Group Densities
Authors: Bieser Arno M. , Tiller Joerg C. 
Published: January 2011

AbstractA series of N‐alkyl‐N,N‐dimethyldeoxyammonium celluloses is synthesized by converting tosyl celluloses with DBA and DDA, respectively. Surface coatings with these water‐insoluble derivatives contain well‐defined densities of quaternary ammonium functions and nonactive hydrophobic and hydrophilic groups. It is shown that the antimicrobial activity of such surfaces against S. aureus requires a delicate balance between DDA, BDA, and hydrophobic groups. A mechanism is proposed that involves the selective adhesion of anionic phospholipids from the bacterial cell membrane. This so‐called phospholipid sponge effect is supported by the fact that all coatings could be deactivated by treatment with SDS or negatively charged phospholipids, but not with neutral phospholipids. magnified image
A new solvent‐free super high build epoxy coating evaluated by marine corrosion simulation apparatus
Authors: Yang X. , Zhang T. , Wang H. , Hou B. 
Published: January 2011

AbstractCoal tar epoxy and epoxy asphalt coating have been widely used to protect marine constructions conventionally. However, their use is being restricted for increasing environmental concerns. Therefore, solvent‐free coating, i.e., coating without volatile organic compounds (VOCs) or hazardous air pollutant has become a new focus. Meanwhile, super high build (SHB) coating, having good anti‐corrosion performance and environment‐friendly feature, has become an important area of development in heavy‐duty protection to marine constructions. Herein, we combine the virtues of solvent‐free and SHB coating to introduce a new solvent‐free SHB heavy‐duty epoxy coating with no organic solvent and extremely low VOC content. Results show that the new coating is environment‐friendly, and has excellent physical properties and anti‐corrosion performance. The SHB coating performed much better than other three widely used coatings, especially in splash zone, the most dynamic area. The new solvent‐free SHB coating provides an ideal substitute to coal tar epoxy and epoxy asphalt coating and is expected to be widely used for anti‐corrosion of steel structures in splash, tidal, and immersed zones.
Depletion sensor for protective high temperature coatings
Authors: Aleksandrov K. , Schütze M. , Teliban I. , Thede C. , Quandt E. 
Published: January 2011

AbstractIn order to minimise corrosion at high temperatures metallic or intermetallic Al‐ and/or Cr‐rich protective coatings are applied to metallic alloys. Protection against corrosion is achieved by the formation of a continuous Al2O3 and/or Cr2O3 layer. Progressive scale formation, as well as interdiffusion between the coating and the substrate during long operating stages depletes the scale‐forming elements, Al and Cr. The decrease of their concentration below a critical value is followed by accelerated corrosion and rapid breakdown of the component. Non‐destructive depletion measurement is not possible, because of the absence of suitable materials that serve simultaneously as depletion sensors and reservoir phases. In a novel development, protective high temperature coatings containing a magnetic phase which at the same time acts as a reservoir phase are used as a depletion sensor. The alloy surface is coated with the magnetic substance either by reactive magnetron co‐sputtering or by using pack cementation. In the course of operation, the formation of a protective oxide scale depletes the reservoir and the measured magnetic signal decreases. Measurement of the change of the coating's magnetic signal enables in situ assessment and non‐destructive detection of depletion. In order to avoid perturbances in the magnetic signal coming from the coating the metallic substrate must be non‐magnetic. Therefore this concept is restricted to Cr/Ni‐austenitic steels and Ni‐base alloys. Doping of AlN with transition metals (Al1 − xMexN, Me = Cr, Co, Mn, x = 2–7 at%) makes it a suitable magnetic reservoir phase, i.e. Al‐ and/or Cr‐containing. Furthermore, it is ferromagnetic, has a high Curie temperature and is magnetically soft. Samples of Alloy 800 and Alloy 602 CA were coated with Al1 − xCrxN (x = 2 and 3 at%) using both pack cementation and PVD. Measurements of the magnetic moments of the coatings at temperatures up to 300 °C show very soft ferromagnetic behaviour. Coatings on different substrates with Al1 − xMnxN, Al1 − xCoxN (x = 2–7 at%) and Al1 − xCrxN with higher Cr contents (x = 4–7%) are underway. Investigations of the magnetic properties of the coatings at temperatures up to the Curie point are also in progress.
Metallic interconnects for solid oxide fuel cell: Performance of reactive element oxide coating during long time exposure
Authors: Fontana S. , Chevalier S. , Caboche G. 
Published: January 2011

AbstractOne of challenges in improving the performance and cost‐effectiveness of SOFCs (solid oxide fuel cells) is the development of suitable interconnects materials. Chromia‐forming alloys and especially ferritic stainless steels, like Crofer22APU, are considered to be among the most promising candidate materials as interconnects in SOFC stacks. However, the performance of chromia‐forming materials can be limited by the low electronic conductivity of the oxide scale (high ASR – area specific resistance – value). Such degradation are unacceptable regarding the long‐term operation (>40 000 h). A previous study 1 demonstrated that in air, the addition of a nanometric reactive element oxide (La2O3) layer applied by metal organic chemical vapor deposition (MOCVD) drastically improved both corrosion rate and electrical properties of Crofer22APU and Haynes230 alloys for 100 h at 800 °C. In this present study coating performances were checked after 10 months (7500 h) and 20 months (15 000 h) at 800 °C in air. The corrosion products were carefully analyzed by SEM, EDX, and XRD. ASR measurements are realized after long time exposure. This study demonstrates that the Crofer22APU alloy has a good oxidation resistance after 15 000 h in air but this alloy has an ASR value equal to 0.370 Ω cm2. The coatings composed of a thin reactive element oxide such as La2O3 resulted in an important improvement in the high temperature oxidation resistance; the ASR values are equal to 0.154 Ω cm2. Haynes230 alloy has a better oxidation resistance but the formation of an insulating Al2O3/SiO2 layer could be detrimental.
Internal oxidation of Fe–3%Si alloys annealed under H2O–H2 atmosphere
Authors: Yamazaki S. , Takahashi F. , Kubota T. , Yanagihara K. 
Published: January 2011

AbstractInternal oxidation phenomena during decarburization annealing are very important in the manufacturing process of grain oriented electrical steel. In the present study, the internal oxidation of nearly pure Fe–3%Si alloy was investigated, as a basic study for decarburization annealing. Annealing was performed at various $P_{{\rm H}_{{\rm 2}} {\rm O}} /P_{{\rm H}_{{\rm 2}} } $ ratios and at 1123 K for 300 s. The transition of external to internal oxidation took place at $P_{{\rm H}_{{\rm 2}} {\rm O}} /P_{{\rm H}_{{\rm 2}} } $ around 0.01. The morphologies of oxide in the internal oxidation zone (IOZ) were filamentary or needle‐like shapes and different from the reported oxide shapes in industrial electrical steel. These peculiar morphologies affected the kinetic aspects such as the depth and the enrichment of oxide in the IOZ.
Metal dusting behaviour of several nickel‐ and cobalt‐base alloys in COH2H2O atmosphere
Authors: Wu Q. , Zhang J. , Young D. J. 
Published: January 2011

AbstractThe metal dusting behaviour of total 11 nickel‐ and cobalt‐base alloys at 680 °C in a gas of 68%CO31%H21%H2O (aC = 19.0, $p_{{\rm O}_{{\rm 2}} } $ = 5.4 × 10−25 atm) was investigated. All samples were electropolished and reacted in a thermal cycling apparatus. On the basis of their reaction kinetics, these alloys can be classified into three groups: the first, with rapid carbon uptake and significant metal wastage, consists of alloys of relatively high iron content (AC 66, 800H and NS‐163); the second, with intermediate rates, consists of some Co‐base alloys (HAYNES 188, HAYNES 25 and ULTIMET) and the third, with very low reaction rates, consists of nickel‐base alloys with high chromium levels (601, HAYNES HR 160, 230, G‐35 and EN 105). An external chromia scale protected group 3 alloys from carburization and dusting. However, this protective scale was damaged and not rehealed for group 1 and group 2 alloys, allowing carbon attack. In all cases, coke deposited on the surface with two typical morphologies: filaments and graphite particle clusters. Subsurface spinel formation in high iron‐content alloys led to rapid dusting due to the significant volume expansion. Alloy carbon permeability was calculated from a simple law of mixtures, and shown to correlate reasonably well with initial dusting rate except for one cobalt‐base alloy in which iron spinel formation was significant.
Effect of water vapour on cyclic oxidation of Fe–Cr alloys
Authors: Othman N. K. , Zhang J. , Young D. J. 
Published: January 2011

AbstractModel Fe–Cr alloys containing 9, 17 or 25 wt% Cr were subjected to repeated 1 h cycles of exposure at 700 °C to flowing gas mixtures of Ar‐20O2, Ar‐20O2‐5H2O and Ar‐5O2‐20H2O (all in volume %) for up to 400 cycles. The kinetics and morphological development of these reactions were compared with those found during isothermal exposure to the same gases. Under isothermal conditions, all alloys developed thin protective chromium‐rich scales in dry oxygen. Addition of 5% H2O induced breakaway for Fe‐9Cr within 48 h, but had little effect on higher chromium alloys. Isothermal chromia scale growth on Fe‐17Cr and Fe‐25Cr was accelerated by the addition of 20% H2O, but breakaway did not result. Under cyclic conditions in dry oxygen, Fe‐9Cr quickly entered breakaway, oxidising according to fast, linear kinetics, but the higher chromium alloys exhibited protective behaviour. When 5% H2O was added to the oxygen, the 17% Cr alloy also underwent fast breakaway oxidation, but Fe‐25Cr continued to be protected by a chromia scale. In the 20% H2O gas, all alloys failed under cyclic conditions, producing thick, iron‐rich oxide scales. The synergistic effects of water vapour and temperature cycling are discussed in terms of alloy chromium depletion and the effects of H2O(g) on oxide transport properties.
Influence of minor additions on the emissivity of the oxide scale of FeCrAlY alloys during resistance heating
Authors: Hattendorf H. 
Published: January 2011

AbstractChromium aluminum yttrium (FeCrAlY) alloys owe their low oxidation rate to the formation of a slow growing α‐alumina scale. For material used for heating elements not only the life time and the behavior of the resistance during the life time is of relevance, but also the emission coefficient of the oxide scale. The power density JS produced by resistance heating of strip with 50 µm thickness and about 5–6 mm width at 1050 °C is approximately equal to the radiant flux density, which is according to Stefan–Boltzmann's law proportional to the total emission coefficient εg. Resistance heating tests were performed on samples made from FeCrAlY alloys with different zirconium and carbon content. The “high zirconium” containing FeCrAlY alloys (zirconium > about 0.10%) have a higher power density/emissivity than the “low zirconium” alloys. In parallel with this, all samples with higher power density/emissivity have internal oxidation and therefore a “rough” metal–oxide interface. Thus, one cause for the increase of the emissivity of the scale could be this rough metal–oxide interface; other causes could be a higher amount of zirconium incorporated into the scale, more pores and/or different grain structure in the scale. Additionally the carbon content influences the appearance of a higher emissivity and the internal oxidation.
Combined Al‐ plus F‐treatment of Ti‐alloys for improved behaviour at elevated temperatures
Authors: Donchev A. , Kolitsch A. , Schütze M. , Yankov R. 
Published: January 2011

AbstractTitanium is a widely used structural material because of its low specific weight, good mechanical properties and excellent corrosion resistance at ambient temperature. As a result of increased oxidation at elevated temperatures and environmental embrittlement the maximum operation temperature of standard Ti‐alloys is only about 600 °C. The oxidation behaviour can be improved by different methods, e.g. coatings. This leads to an improvement which is, however, often limited. The combination of Al‐enrichment in the sub surface zone, so that a TiAl‐layer is formed, plus F‐treatment gives impressively good results because a protective alumina scale is formed due to the fluorine effect. This alumina scale prevents oxygen inward diffusion which causes embrittlement and protects the material against environmental attack. The procedure is applied to alloys with a very low Al‐content or even no Al at all. In the paper results of oxidation tests of α‐Ti without any treatment, with Al‐treatment and with a combination of Al‐ + F‐treatment are presented. Aluminium was diffused into the samples by a powder pack process. Fluorine was applied by a liquid phase process. The formation of an alumina scale on treated samples was revealed by post experimental investigations. The results are discussed referring to the fluorine effect model for TiAl‐alloys.
Comparison between field and laboratory steam oxidation testing on aluminide coatings on P92
Authors: Agüero A. , González V. , Gutiérrez M. , Knödler R. , Muelas R. , Straub S. 
Published: January 2011

AbstractSteam oxidation has become an important issue for steam power plants as operating temperatures increase from the current 550 to 600–650 °C. For the last 10 years several groups have been carrying out steam oxidation testing of both uncoated substrates and coatings in the laboratory. On the other hand, field testing results are very scarce. In this paper, a comparison of laboratory steam oxidation testing with field test results carried out by Alstom at the Kraftwerk Westfalen power station located in Hamm, Germany will be presented. Both slurry deposited aluminide coatings and uncoated P92 steel have been included in the study. Under steam (atmospheric pressure) and isothermal conditions in the laboratory at 650 °C, spallation of oxides formed on ferritic steels occurs after significantly longer time when compared to exposure to real operating conditions. Oxide spallation results in serious damage in steam power plants by obstructing heat exchanger tubes, erosion of valves and turbine blades, etc. Moreover, the thickness of the oxide scales formed under field testing conditions is significantly higher after similar exposure. On the other hand, aluminide coated P92, which exhibit thickness through cracks, have shown to be stable in the laboratory for up to 60 000 h at 650 °C under steam, without evidence of crack propagation. However, field test results indicate that some degree of crack propagation occurs but without causing substrate attack up to 21 700 h of exposure. Moreover, the aluminium oxide observed in both laboratory and field tested specimens is different.
Oxidation protection of Ni‐base superalloys by halogen treatment
Authors: Zschau H.‐E. , Masset P. J. , Schütze M. 
Published: January 2011

AbstractA new concept of oxidation protection is proposed for Ni‐base alloys with Al‐amounts of 2–5 wt%. Following Wagner's theory of oxidation the formation of a dense protective alumina scale is possible if the Al‐activity is sufficiently high. This condition can be fulfilled by using the halogen effect. Thermodynamical calculations reveal the existence of regions for a positive effect of F and Cl for the alloys IN738 and IN939. In the case of fluorine these results are transformed into F concentrations in a screening by using ion implantation. By the F‐effect the oxidation mechanism at 1050 °C/air was changed from internal oxidation of Al to an external formation of an Al2O3 – scale. Optimal implantation parameters were defined. The formation and stability of the protective alumina scale was proved within 1000 h/1050 °C.
Electrochemical investigations on corrosion protection oils
Authors: Eich G. , Schneider J. , Zimmermann J. 
Published: January 2011

AbstractTribologically affected surfaces of high‐strength steels often only may be protected against corrosion by the use of specific protecting oils. The protective effectiveness of these products is usually assessed by neutral salt spray test during qualification. As this test method takes a long time and because the reproducibility is poor a new test method was developed based on electrochemistry. It could be shown that a distinction was possible between well and nonprotecting oils based on current density curves and electrochemical impedance spectroscopy.
Corrosion behavior of SRB Desulfobulbus propionicus isolated from an Indian petroleum refinery on mild steel
Authors: Anandkumar B. , George R. P. , Maruthamuthu S. , Palaniswamy N. , Dayal R. K. 
Published: January 2011

AbstractIn this study, Desulfobulbus propionicus (D. propionicus), a sulfate reducing bacterium (SRB) was isolated and identified in cooling towers by molecular biologic techniques. This bacterial species has been reported for the first time in the cooling towers of an Indian petroleum refinery. Corrosion behaviors were analyzed by electrochemical and weight loss methods. The high corrosion rate and the enhancement of anodic current in increased chloride environment was noticed in the presence of D. propionicus indicating that this SRB species enhances the pitting corrosion of mild steel. Propionate metabolism in H2S production is discussed as a new pathway of corrosion enhancement.
Ultrasound‐Induced Disruption of Amphiphilic Block Copolymer Micelles
Authors: Xuan Juan , Pelletier Maxime , Xia Hesheng , Zhao Yue 
Published: January 2011

AbstractUltrasound‐induced disruption of PEO‐b‐PTHPMA, PEO‐b‐PIBMA, PEO‐b‐PTHFEMA, and PEO‐b‐PMMA block copolymer micelles in aqueous solution was investigated. Fluorescence change of loaded NR, DLS, IR, AFM, and SEM show that those micelles could be disrupted differently by 1.1 MHz high‐intensity focused ultrasound beams. The micelles of PEO‐b‐PIBMA and PEO‐b‐PTHPMA appear to be more sensitive to ultrasound irradiation, resulting in a more severe micellar disruption, and IR spectra show evidence of ultrasound‐induced chemical reactions, most likely hydrolysis. PEO‐b‐PMMA appear to resist HIFU irradiation better, and IR analysis found no evidence of chemical reactions. This study provides new evidence for the prospect of ultrasound‐responsive BCP micelles for controlled delivery applications. magnified image
A Cohen type inequality for Fourier expansions of orthogonal polynomials with a non‐discrete Gegenbauer‐Sobolev inner product
Authors: Fejzullahu Bujar Xh. 
Published: January 2011

AbstractLet dμ(x) = (1 − x2)α−1/2dx,α> − 1/2, be the Gegenbauer measure on the interval [ − 1, 1] and introduce the non‐discrete Sobolev inner product

where λ>0. In this paper we will prove a Cohen type inequality for Fourier expansions in terms of the polynomials orthogonal with respect to the above inner product. Results on divergence for Cesàro means of Gegenbauer‐Sobolev expansions are deduced. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim