bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDIES ON AGE HARDENING FOR IMPROVEMENT OF 6261 AND 6060 EXTRUDED ALUMINIUM ALLOYS
Authors: AU KA KI (KATIE) , HODGSON MICHAEL , PASANG TIMOTIUS , CHIU YU LUNG
Published: August 2010

The magnesium silicide precipitates in the 6XXX series alloy are the main components contributing to the heat treatable properties and T6 strength of the alloy, which is influenced by the size, morphology and distribution of this phase. During the extrusion process, the strength contributing phase, magnesium silicide is supposed to dissolve and form again in a controlled state during age hardening. Whereas the intermetallic AlFeSi phase has little if any influence on the strength, the β phase of this intermetallic is known to cause brittle fracture of this alloy, as opposed to the less detrimental, more equiaxed α phase formed during homogenisation.

This study investigates the as-extruded 6060 and the more heavily alloyed 6261 aluminium alloys, as well as the subsequent heat treated forms to investigate the ageing conditions to optimise hardening and shorten age hardening times for higher cost effectiveness. The microstructure, texture and precipitate size and distributions were studied using optical microscopy, SEM, EBSD and DSC. SEM and EDAX results have indicated signs of evenly distributed α AlFeSi and β Magnesium Silicide precipitates. The phase responsible for hardening is believed to be the much smaller scaled β" magnesium silicide, requiring much higher resolution studies.
ELECTROCHEMICAL BEHAVIOR AND CORROSION MORPHOLOGY OF SICP/5A06 ALUMINUM ALLOY COMPOSITE
Authors: AZIZ IRFAN , ZHANG QI , TANG ZHANMEI , JIANG ZHIKUN
Published: August 2010

The corrosion morphology and electrochemical behavior of 5A06 aluminum alloy and SiC p / 5 A 06 aluminum matrix composite (MMC), were investigated by means of the immersion test and various electrochemical techniques. The surface morphology of the samples tested was observed by optical (OM) and scanning electron microscopy (SEM) accompanied with energy dispersion spectroscopy (EDS) to reveal the damage caused by the immersion. It was found that the composite corroded faster than the matrix alloy due to the presence of fine and uniformly distributed intermetallics and crevices at the SiC p / matrix interface, rather than galvanic corrosion between SiC p and the matrix phase. Cyclic potentiodynamic polarization (CV) and the variation of the open circuit potential with time ( E corr -t) were carried out and revealed similar corrosion potential ( E corr ) and pitting potential ( E pit ) for the composite and the matrix alloy. More pitting initiation sites were recorded on the composite surface, in accordance with its greater electronegative protection potential ( E prot ).
COMPOSITION DESIGN AND GLASS-FORMING ABILITY OF TI-BASED BULK METALLIC GLASSES
Authors: ZHAO LEI , ZHANG ZEQIANG , ZHANG JING , PANG SHUJIE , MA CHAOLI , ZHANG TAO
Published: August 2010

Ti -based bulk metallic glasses (BMGs) have great potential for use as structural materials due to their excellent mechanical properties. How to fabricate Ti -based metallic glasses with sufficient large size has always been the key issue in both the theoretic and technology aspects since finding the BMG. In this paper, we try to fabricate Ti -based metallic glasses with high glass-forming ability (GFA) through composition design based on various empirical ideas. BMG alloy with composition of Ti 43.89 Cu 43.60 Zr 6.75 Ni 5.76 was synthesized based on the deep eutectic idea, and the critical diameter of this glassy alloy reaches to 2 mm. The GFA of this alloy was further improved by small addition of Si (0.5-1 at %). BMG rods with diameters up to 3mm were synthesized for compositions of Ti 42.89 Cu 43.60 Zr 6.75 Ni 5.76 Si 1, Ti 43.89 Cu 43.60 Zr 6.25 Ni 5.76 Si 0.5 and Ti 43.89 Cu 43.60 Zr 6.75 Ni 4.76 Si 1. The amorphous structure of all the samples was confirmed by X-ray diffraction (XRD) method. The thermal stability associated with glass transition, supercooled liquid region and crystallization was investigated by differential scanning calorimetry (DSC). Possible mechanisms for the improvement of GFA were discussed.
PRECIPITATION IN FE-NI-CO-TI FERROMAGNETIC SHAPE MEMORY ALLOY
Authors: JIN M. J. , DING H. , GU Y.J. , JIN X. J.
Published: August 2010

Fe - Ni - Co - Ti alloys have been concerned as a potential magnetically induced shape memory alloy (MISMA) with high output power and low cost. Thin plate martensite with twin substructure, which is the key to get MISME, can be preserved at room temperature only after appropriate heat treatment in a certain composition range. Precipitation transformation in Fe - Ni - Co - Ti alloy was investigated by means of electrical resistivity and stress relaxation methods in this paper. Kinetics of precipitation was also discussed with JMA Equation.
RESIDUAL STRESS AND MAGNETIC PROPERTIES OF Fe-Ga THIN FILMS
Authors: WANG B. W. , CAO S. Y. , HUANG W. M. , WENG L. , SUN Y.
Published: August 2010

Fe - Ga thin films were prepared by DC magnetron sputtering on Si (100) substrate and an alloy target consisting of Fe 81 Ga 19 was used. X-ray diffraction techniques were used to quantify the strain in the Fe - Ga thin films by measuring the interplanar spacings of select crystallographic planes. The interplanar spacing, d, for the family of Fe - Ga {211} planes was measured. Using the well-established sin 2ψ technique, the residual stress of the Fe - Ga thin films was calculated. It has been found that the stress for Fe - Ga thin films quickly increases with increasing the sputtering power. The residual stress of thin films is almost unchanged in the range of 220-440 nm, and then it decreases with increasing the thickness of thin films.
A CORRELATION BETWEEN THE AGING PARAMETER AND ELECTRICAL RESISTIVITY FOR THE DEGRADED 9 CR STEEL
Authors: BAEK UN BONG , LEE YUN-HEE , NA HO JUN , NAHM SEUNG HOON , NAM YOUNG HYUN
Published: August 2010

It is advantageous to use a non-destructive evaluation (NDE) method to assess the mechanical properties of materials since conventional methods are time-consuming and usually require sampling from the material or component. In this study, an electrical resistivity method was attempted for the estimation of the creep damage of degraded 9 Cr steel. The specimens with six different kinds of aging periods were prepared by an isothermal heat treatment at 690 °C. The electrical resistivity was determined by a standard DC four-point probe method at 24±0.5 °C. The home-made probe station and Burster 2304 were utilized for the resistance measurement. A correlation between the measured electrical resistivity and the tensile properties was studied. The electrical resistivity showed a declining tendency with the increase of aging time because the electrical resistivity is strongly dependent on the microstructural changes. A correlation between the electrical resistivity and aging parameter was established, which allows one to estimate the material degradation of 9 Cr steel.
THE SULFIDE STRESS CORROSION CRACKING CHARACTERISTICS OF THE PIPE WELD IN THE PETROCHEMICAL PLANT
Authors: LEE GYU YOUNG , BAE DONG HO
Published: August 2010

Sulfide stress corrosion cracking (SSCC) in crude oil field environment including hydrogen sulfide ( H 2 S ) has been recognized as a materials failure mechanism. Welding residual stress generation and metallurgical change by fusion welding process increase the cracking driving force and reduce the resistance of brittle fracture as well as environmental fracture. On the base of this understanding, firstly, we analyzed welding residual stresses of welded ASTM A 106 Gr B steel pipe using in the petrochemical plant. And next, SSCC tests were conducted to assess SSCC resistance of the weld with smooth specimens. From the result, influence of temperature on corrosion rate was sensitive in order of HAZ, base metal and weld metal. Therefore, the most sensitive region in the weld is HAZ, and its corrosion rate increases with the temperature of corrosion environment increase. And failure positions of the most cases among failed specimens were at HAZ of the weld. Low limit (σ SSCC ) of A 106 Gr B steel pipe was assessed as 0.6 σ y (7271.6N)
A STUDY ON FRACTURE BEHAVIORS OF CERAMIC USING SHOCK COMPRESSIVE WAVE
Authors: KIM JAE-HOON , LEE YOUNG-SHIN , HWANG KWON-TAE , SHIM WOO-SUNG , PARK JONG-HO , SONG KEE-HYEUK , YOON SU-JIN
Published: August 2010

An experimental investigation was carried out to evaluate the fracture pressure and behaviors of ceramic materials for a dome port cover of an air breathing engine. The experiments were performed in a shock tube, which had a working section of 70 mm in diameter and a total length of 6 m in the shock tube. The response pressure transducers were used to measure expansion pressure and reflection pressure of working section near the end edge of the shock tube. Fractured specimens collected from the dump tank were investigated for the fracture phenomenon of ceramics after testing. The fracture pressure increases as a specimen thickness increases, and as the specimen diameter decreases, respectively. The driven gas pressures P 2 obtained from theory and experiment agree well. The reflection wave pressures P 5 agree well comparatively with both results of equation and experiment at low pressure of P 4, but they do not agree well at high pressure of P 4. The fracture phenomena of the plate and dome specimens at the same diameter are broken into small particles in various thicknesses, but the fracture phenomenon of the plate specimen is not broken into the particles as specimen diameter decreases.
EFFECTS OF HEAT TREATMENT ON THE TENSILE BEHAVIOR AND DAMAGE EVOLUTION OF A 3D C/SIC COMPOSITE
Authors: WANG YIQIANG , ZHANG LITONG , CHENG LAIFEI
Published: August 2010

The tensile responses and the associated damage evolutions of a 3D C / SiC composite with and without heat treatment on the fiber preforms were compared. The results show that the composite without heat treatment exhibits a largely non-linear stress-strain behavior up to rupture as well as a lower strength and a strain-to-failure. The damage evolution characterized by acoustic emission indicates the composite failures in the region of matrix cracking multiplication. However, the composite with heat treatment has a larger strength and a strain-to-failure, and the damage evolution indicates that the composite had experienced the region of matrix cracking saturation and then fiber bundle pull-out just prior to final failure. Microstructural observations on the fractured specimens revealed the interfacial bonding between fibers and matrix becomes weaker after heat treatment.
THE FRICTION AND WEAR CHARACTERISTICS OF SI3N4 CERAMIC AGAINST SI3N4 CERAMIC ZRO2 CERAMIC AND CHILLED CAST IRON AND AL2O3 CERAMIC UNDER DRY FRICTION
Authors: TIAN XIAO , NIU JIANGANG , WANG CUIBIAO
Published: August 2010

The friction and wear of silicon nitride ( Si 3 N 4) against silicon nitride ( Si 3 N 4) and zirconia (Y–TZP) and chilled cast iron and Alumina sliding under dry friction at room temperature conditions were investigated with pin-on-disk tribometer at sliding speed of 0.56ms-1 and normal load of 50N, 80N, respectively. Based on the variety regulation of the wear maps, the wear mechanisms of the two couples were analyzed. Get the result of friction coefficient and maps of wear Rate of the Pin and the Disk. The results of comparing this couple is Si 3 N 4/ chilled cast iron < Si 3 N 4/ ZrO 2< Si 3 N 4/ Si 3 N 4< Si 3 N 4/ Al 2 O 3.
SOLUTE FIELD ACROSS DIFFUSE INTERFACE DURING TRANSIENT PROCESS OF BINARY ALLOYS SOLIDIFICATION IN PHASE FIELD MODE
Authors: WANG ZHIJUN , WANG JINCHENG , YANG GENCANG
Published: August 2010

The establishment of solute boundary layer is studied by using a quantitative phase field model during the initial transient stage of binary alloys solidification. Results reveal that the time-dependent solute distribution shows good agreements with the previous analytical results. The planar instability is discussed according to the time-dependent constitutional supercooling with different pulling velocities. Moreover, the critical pulling velocity of planar instability can be obtained by investigating the interface velocity of the critical instability with different pulling velocities.
TOOL STRESS PATTERN DEPENDING ON TOOL GEOMETRY
Authors: LEE YOUNG MOON , CHOI WON SIK , SON JAE HWAN , KIM SUN IL , JUNG HEE CHUL
Published: August 2010

In metal cutting practices, for a given tool material, tool geometry is a very important element and must be carefully designed in relation to the workpiece material to be machined. Patterns of tool stress are varying with input cutting conditions; however, effects of tool geometry on tool stress are not clearly understood. The load distribution on tool face is affected by the tool geometry and this causes the change of the stress distribution on the tool.
THE EFFECT OF HIGH TEMPERATURE CORROSION ON MECHANICAL BEHAVIOR OF A GAMMA-TiAl ALLOY
Authors: ZHAO WENYUE , MA YUE , GONG SHENGKAI
Published: August 2010

The mechanical properties of Ti -48 Al -2 Cr -2 Nb alloy were discussed after the high temperature corrosion tests carried out with salt mixture of 75wt. % Na 2 SO 4 and 25wt. % NaCl at 800°C. The microstructure of the alloy after corrosion was observed by SEM and the fracture behavior of the corroded and uncorroded alloys was investigated by means of the three-point bending tests. It has been shown that the corrosion path was mainly along the lamellar structure and rough surface with a large number of corrosion pits formed during the high temperature corrosion. The experimental results also indicated that the bearing capacity of bending fracture descended evidently due to the molten salt corrosion at high temperature, which only had remarkable effects on the surface state of the alloy. The microcracks inside the alloy always propagated along the phase interfaces and grain boundaries while the corrosion pits on salt-deposited surface became the main crack initiation location in corroded alloy. The stress concentration caused by corrosion was considered as the essential reason of the property reduction, which decreased the energy barrier of crack nucleation and shortened the incubation period.
SELF-FORMATION OF MgO OR Al2O3 SURFACE LAYER BY ANNEALING OF CuMg OR CuAl DILUTE ALLOYS
Authors: ZHU Y. F. , JIANG Q. , HONG S. H. , MIMURA K. , ISSHIKI M. , LIM J. W.
Published: August 2010

Self-formation of MgO or Al 2O3 surface layer on CuMg or CuAl alloys by annealing in H 2 gas was investigated theoretically and experimentally. Theoretical consideration shows that Mg or Al can segregate to the surface of Cu during the annealing, while the enrichment ability is much stronger for Mg . Meanwhile, the MgO or Al 2O3 surface layer is self-formed by the preferential reaction of Mg or Al with O 2 remnant in H 2 atmosphere. The Al 2O3 surface layer is expected to play a role in passivating the surface of Cu . However, the MgO layer would suffer failure in passivating the surface due to incorporation of Cu and fissures formed in MgO during the annealing process. Our theoretical predictions are in agreement with experimental observations.
EVALUATION OF INTERFACIAL STRENGTH OF BNT FILMS HYDROTHERMALLY DEPOSITED ON TITANIUM SUBSTRATES
Authors: KUSUKAWA KAZUHIRO , XU FANGCHAO
Published: August 2010

Lead-free piezoelectric ( Bi 1/2 Na 1/2) TiO 3 (abbreviated as BNT) films were deposited on 0.2 mm thick pure titanium( Ti ) substrates by a hydrothermal method. Scratch tests and Vickers indentation tests were performed to quantitatively assess the adhesion strength between BNT films and Ti substrates. Some of Ti substrates were pretreated by chemical polish and mechanical polish respectively prior to BNT film deposition with a view of investigating the effects of substrate surface pretreatments on the adhesion of BNT films. In the scratch test, the critical force was determined from the variations of the tangential force and the acoustic emission (AE) signals with the normal force. The scratch test results revealed that the chemical polish pretreatment effectively improved the adhesion of BNT films. In addition, the critical substrate strain inducing the adhesion failure of BNT films has been investigated by the Vickers indentation test combined with finite element analysis (FEM).
ROLLING CONTACT FATIGUE CHARACTERISTICS OF SAE52100 BY ULTRASONIC NANOCRYSTAL SURFACE MODIFICATION TECHNOLOGY
Authors: LEE CHANG-SOON , PARK IN-GYU , PYOUN YOUNG-SHIK , CHO IN-SHIK , CHO IN-HO , PARK JIN
Published: August 2010

UNSM(Ultrasonic Nanocrystal Surface Modification) technology has been applied to test specimens of bearing rings and rollers made of SAE52100. Mechanical properties, especially rolling contact fatigue characteristics, are analyzed using two-roller test and 6-ball test before and after UNSM treatment. The main effects to improve rolling contact fatigue characteristics by UNSM treatment are explained in the view points of residual stress, hardness and surface topology.
CORROSION MECHANISM AND MODEL OF ANODIZED FILM ON AZ91D MAGNESIUM ALLOY
Authors: LI LINA , QIAN JIANGANG , LU ZHAOZHONG , SUN ZHONGWU
Published: August 2010

The corrosion behavior of anodized film on AZ91D magnesium alloy in 3.5% neutral NaCl solution was investigated by saline immersion test. The results show that new corrosion points seldom occur on the surface of the said anodized film during the immersion time in 3.5% NaCl neutral aqueous solution after the first macroscopic corrosion point appears on the anodized film, while the previous corrosion point extends vertically or horizontally and turns into a corrosion pit which is in form of "strip". Moreover, the corrosion occurs firstly on α phase rather than β phase, when the corrosion of anodized film reaches the Mg alloy substrate. The corrosion products of anodized film on AZ91D magnesium alloy in neutral immersion solution were analyzed by XRD. A possible corrosion reaction and model about the corrosion of anodized film on AZ91D magnesium alloy in NaCl solution based on the experimental results is proposed.
INFLUENCE OF DEPOSITION CONDITIONS ON FATIGUE PROPERTIES OF MARTENSITIC STAINLESS STEEL WITH TIN FILM COATED BY ARC ION PLATING METHOD
Authors: FUKUI SATOSHI , YONEKURA DAISUKE , MURAKAMI RI-ICHI
Published: August 2010

The surface properties like roughness etc. strongly influence the fatigue strength of high-tensile steel. To investigate the effect of surface condition and TiN coating on the fatigue strength of high-strength steel, four-point bending fatigue tests were carried out for martensitic stainless steel with TiN film coated using arc ion plating (AIP) method. This study, using samples that had been polished under several size of grind particle, examines the influence of pre-coating treatment on fatigue properties. A 2-µm-thick TiN film was deposited onto the substrate under three kinds of polishing condition. The difference of the hardness originated in the residual stress or thin deformation layer where the difference of the size of grinding particle of the surface polishing. And it leads the transformation of the interface of the substrate and the TiN film and improves fatigue limit.
HOT-CORROSION BEHAVIOR OF THERMAL BARRIER COATED DZ125 SUPERALLOY EXPOSED TO ATOMIZED SEAWATER AND KEROSENE
Authors: BAI ZHIMING , ZHOU LE , LIANG TIANQUAN , GUO HONGBO , GONG SHENGKAI
Published: August 2010

The bare superalloy DZ 125 alloy, the aluminide coated specimens and electron beam physical vapor deposited (EB-PVD) thermal barrier coating (TBC) consisting of yttria stabilizied zirconia (YSZ) topcoat and NiCoCrAlY bond coat specimens were exposed to atomized seawater and kerosene at 900°C and the cyclic hot-corrosion behaviors of the specimens were investigated. Disastrous spallation of the bare superalloy occurred within 50 h hot-corrosion. In contrast to this, after 100 h hot-corrosion, the average mass change for the aluminized and TBC coated specimens is 0.7 mg/cm2 and 0.63 mg/cm2, respectively, exhibiting excellent hot-corrosion resistance.
MORPHOLOGICAL AND OPTICAL CHARACTERIZATION OF ELECTROSPUN ZINC OXIDE NANOFIBERS
Authors: GANJI M. ESMAEILPOUR , BAZARGAN A. M. , KEYANPOUR-RAD M. , BAHREVAR M. A.
Published: August 2010

A combination of the remarkably simple technique of electrospinning, developed to fabricate polymer nanofibers, and sol–gel processing has been utilized to produce fine zinc oxide nanofibers with an average diameter of 70 nm. A non-toxic precursor solution of polyvinyl alcohol and zinc acetate was electrospun and the resulting fibers were then calcined at a relatively low temperature to produce ZnO nanofibers. Simultaneous thermal analyses were used to study the formation of ZnO nanofibers from the precursor material. X-ray diffraction was employed to analyze the phases and different microscopy techniques, such as scanning electron microscopy, transmission electron microscopy and atomic force microscopy were used to study the morphology and size of the fibers. Fourier transform infrared spectroscopy was employed to investigate the composition of the precursor and ZnO fibers. The specific surface area of the electrospun nanofibers was determined using the Brunauer–Emmett–Teller method and optical properties were measured by UV-Vis and PL spectroscopy. The very high specific surface area of the ZnO fibers makes them potential candidates for nanodevice applications in gas sensing, dye-sensitized solar cells, and UV/blue emission devices.
Sphingosine-1-phosphate prevents permeability increases via activation of endothelial sphingosine-1-phosphate receptor 1 in rat venules
Authors: Zhang Gengqian , Xu Sulei , Qian Yan , He Pingnian
Published: August 2010

Sphingosine-1-phosphate (S1P) has been demonstrated to enhance endothelial barrier function in vivo and in vitro. However, different S1P receptor subtypes have been indicated to play different or even opposing roles in the regulation of vascular barrier function. This study aims to differentiate the roles of endogenous endothelial S1P subtype receptors in the regulation of permeability in intact microvessels using specific receptor agonist and antagonists. Microvessel permeability was measured with hydraulic conductivity ( Lp) in individually perfused rat mesenteric venules. S1P-mediated changes in endothelial intracellular Ca2+ concentration ([Ca2+]i) was measured in fura-2-loaded venules. Confocal images of fluorescent immunostaining illustrated the spatial expressions of three S1P subtype receptors (S1PR1–3) in rat venules. The application of S1P (1 μM) in the presence of S1PR1–3 inhibited platelet-activating factor- or bradykinin-induced permeability increase. This S1P effect was reversed only with a selective S1PR1 antagonist, W-146, and was not affected by S1PR2 or S1PR3 antagonists JTE-013 and CAY-10444, respectively. S1PR1 was also identified as the sole receptor responsible for S1P-mediated increases in endothelial [Ca2+]i. S1PR2 or S1PR3 antagonist alone affected neither basal Lp nor platelet-activating factor-induced permeability increase. The selective S1PR1 agonist, SEW-2871, showed similar [Ca2+]i and permeability effect to that of S1P. These results indicate that, despite the presence of S1PR1–3 in the intact venules, only the activation of endothelial S1PR1 is responsible for the protective action of S1P on microvessel permeability and that endogenous S1PR2 or S1PR3 did not exhibit functional roles in the regulation of permeability under basal or acutely stimulated conditions.
Atrial natriuretic peptide attenuates LPS-induced lung vascular leak: role of PAK1
Authors: Birukova Anna A. , Xing Junjie , Fu Panfeng , Yakubov Bakhtiyor , Dubrovskyi Oleksii , Fortune Jennifer A. , Klibanov Alexander M. , Birukov Konstantin G.
Published: August 2010

Increased levels of atrial natriuretic peptide (ANP) in the models of sepsis, pulmonary edema, and acute respiratory distress syndrome (ARDS) suggest its potential role in the modulation of acute lung injury. We have recently described ANP-protective effects against thrombin-induced barrier dysfunction in pulmonary endothelial cells (EC). The current study examined involvement of the Rac effector p21-activated kinase (PAK1) in ANP-protective effects in the model of lung vascular permeability induced by bacterial wall LPS. C57BL/6J mice or ANP knockout mice (Nppa−/−) were treated with LPS (0.63 mg/kg intratracheal) with or without ANP (2 μg/kg iv). Lung injury was monitored by measurements of bronchoalveolar lavage protein content, cell count, Evans blue extravasation, and lung histology. Endothelial barrier properties were assessed by morphological analysis and measurements of transendothelial electrical resistance. ANP treatment stimulated Rac-dependent PAK1 phosphorylation, attenuated endothelial permeability caused by LPS, TNF-α, and IL-6, decreased LPS-induced cell and protein accumulation in bronchoalveolar lavage fluid, and suppressed Evans blue extravasation in the murine model of acute lung injury. More severe LPS-induced lung injury and vascular leak were observed in ANP knockout mice. In rescue experiments, ANP injection significantly reduced lung injury in Nppa−/− mice caused by LPS. Molecular inhibition of PAK1 suppressed the protective effects of ANP treatment against LPS-induced lung injury and endothelial barrier dysfunction. This study shows that the protective effects of ANP against LPS-induced vascular leak are mediated at least in part by PAK1-dependent signaling leading to EC barrier enhancement. Our data suggest a direct role for ANP in endothelial barrier regulation via modulation of small GTPase signaling.
Evaluation of inhaled carbon monoxide as an anti-inflammatory therapy in a nonhuman primate model of lung inflammation
Authors: Mitchell Leah A. , Channell Meghan M. , Royer Christopher M. , Ryter Stefan W. , Choi Augustine M. K. , McDonald Jacob D.
Published: August 2010

Carbon monoxide (CO) confers anti-inflammatory protection in rodent models of lung injury when applied at low concentration. Translation of these findings to clinical therapies for pulmonary inflammation requires validation in higher mammals. We have evaluated the efficacy of inhaled CO in reducing LPS-induced lung inflammation in cynomolgus macaques. LPS inhalation resulted in profound neutrophil influx and moderate increases in airway lymphocytes, which returned to baseline levels within 2 wk following exposure. CO exposure (500 ppm, 6 h) following LPS inhalation decreased TNF-α release in bronchoalveolar lavage fluid but did not affect IL-6 or IL-8 release. Lower concentrations of CO (250 ppm, 6 h) did not reduce pulmonary neutrophilia. Pretreatment with budesonide, a currently used inhaled corticosteroid, decreased LPS-induced expression of TNF-α, IL-6, and IL-8, and reduced LPS-induced neutrophilia by ∼84%. In comparison, CO inhalation (500 ppm, for 6 h after LPS exposure) reduced neutrophilia by ∼67%. Thus, inhaled CO was nearly as efficacious as pretreatment with an inhaled corticosteroid at reducing airway neutrophil influx in cynomolgus macaques. However, the therapeutic efficacy of CO required relatively high doses (500 ppm) that resulted in high carboxyhemoglobin (COHb) levels (>30%). Lower CO concentrations (250 ppm), associated with anti-inflammatory protection in rodents, were ineffective in cynomolgus macaques and also yielded relatively high COHb levels. These studies highlight the complexity of interspecies variation of dose-response relationships of CO to COHb levels and to the anti-inflammatory functions of CO. The findings of this study warrant further investigations for assessing the therapeutic application of CO in nonhuman primate models of tissue injury and in human diseases. The study also suggests that akin to many new therapies in human diseases, the translation of CO therapy to human disease will require additional extensive and rigorous proof-of-concept studies in humans in the future.
TLR-Mediated Preterm Birth in Response to Pathogenic Agents
Authors: Thaxton Jessica E. , Nevers Tania A. , Sharma Surendra
Published: August 2010

The incidence of preterm birth in developed countries has risen in the past decades. Underlying causes for this enigmatic pregnancy complication are numerous, yet infectious agents that induce dysregualtion of immunity at the maternal-fetal interface pose one of the most probable causes of preterm birth. This paper highlights two factors regarding maternal infections that trigger unscheduled inflammatory sequences that are deleterious to the maternal-fetal balance necessary to maintain pregnancy. Firstly, we discuss the role of Toll-like receptors (TLRs) as sentinels of uterine immunity in the context of response to pathogens. We highlight the idea that particular TLR activations lead to differential immune cascades that induce preterm birth. Secondly, two alternative routes of pathogenic entry may prove to be critical for inducing preterm birth via a cytokine storm or a secondary and currently unknown cell-mediated mechanism of uterine inflammation. This paper summarizes pathways that underlie activation of adverse and diverse immune responses to foreign agents that may result in preterm birth.
Differential Impact of Adherence to Pegylated Interferon and Ribavirin in the Treatment of Genotype 1 High Viral Titer Chronic Hepatitis C
Authors: Numata Makoto , Kagawa Tatehiro , Kojima Sei-ichiro , Hirose Shunji , Nagata Naruhiko , Shiraishi Koichi , Watanabe Norihito , Shiozawa Hirokazu , Nishizaki Yasuhiro , Motegi Shigeyuki , Takashimizu Shinji , Kamochi Jun-ichiro , Wasada Mitsuru , Ohno Takashi , Tei Yoshihiro , Nakano Atsushi , Yamada Takuji , Atsukawa Kazuhiro , Watanabe Tetsu , Mine Tetsuya
Published: August 2010

To clarify the impact of adherence, we treated 122 genotype 1 high viral titer chronic hepatitis C patients with pegylated interferon (peg-IFN) and ribavirin for 48 weeks at nine referral hospitals, and evaluated the prognostic factors with a focus on the adherence to the treatment. This study included 68 (55.7%) treatment-naïve patients and 54 (44.3%) patients who did not respond to the previous treatment. Multivariate analysis revealed adherence to peg-IFN and ribavirin as the only significant predictor. Sustained virological response (SVR) rate was 72.2%, 19.0%, and 27.3% in patients given ≥80%, 60%–80%, and <60% dose peg-IFN, respectively, and was 68.6%, 41.2%, and 5.3% in those given ≥80%, 60%–80%, and <60% dose ribavirin, respectively. SVR rate sharply fell when exposure to peg-IFN was below 80% whereas it decreased in a stepwise manner as for ribavirin. Therefore, ≥80% of peg-IFN and as much as possible dose of ribavirin are desired to achieve SVR in the treatment of genotype 1 high viral titer chronic hepatitis C.
Novel Matrix Metalloproteinase Inhibitor [18F]Marimastat-Aryltrifluoroborate as a Probe for In vivo Positron Emission Tomography Imaging in Cancer
Authors: auf dem Keller Ulrich , Bellac Caroline L. , Li Ying , Lou Yuanmei , Lange Philipp F. , Ting Richard , Harwig Curtis , Kappelhoff Reinhild , Dedhar Shoukat , Adam Michael J. , Ruth Thomas J. , Bénard François , Perrin David M. , Overall Christopher M.
Published: August 2010

Matrix metalloproteinases (MMP), strongly associated pathogenic markers of cancer, have undergone extensive drug development programs. Marimastat, a noncovalent MMP inhibitor, was conjugated with FITC to label cellular metalloproteinase cancer targets in MDA-MB-231 cells in vitro. Punctate localization of active transmembrane MMP14 was observed. For molecular-targeted positron emission tomography imaging of syngeneic 67NR murine mammary carcinoma in vivo, marimastat was 18F-labeled using a shelf-stable arylboronic ester conjugate as a captor for aqueous [18F]fluoride in a novel, rapid one-step reaction at ambient temperature. [18F]Marimastat-aryltrifluoroborate localized to the tumors, with labeling being blocked in control animals first loaded with >10-fold excess unlabeled marimastat. The labeled drug cleared primarily via the hepatobiliary and gastrointestinal tract, with multiple animals imaged in independent experiments, confirming the ease of this new labeling strategy. Cancer Res; 70(19); 7562–9. ©2010 AACR.
Ergonomic Factors Related to Drop-Off Detection With the Long Cane: Effects of Cane Tips and Techniques
Authors: Kim Dae Shik , Wall Emerson Robert S. , Curtis Amy B.
Published: August 2010

Objective: This study examined the effect of cane tips and cane techniques on drop-off detection with the long cane.

Background: Blind pedestrians depend on a long cane to detect drop-offs. Missing a drop-off may result in falls or collision with moving vehicles in the street. Although cane tips appear to affect a cane user’s ability to detect drop-offs, few experimental studies have examined such effect.

Method: A repeated-measures design with block randomization was used for the study. Participants were 17 adults who were legally blind and had no other disabilities. Participants attempted to detect the drop-offs of varied depths using different cane tips and cane techniques.

Results: Drop-off detection rates were similar between the marshmallow tip (77.0%) and the marshmallow roller tip (79.4%) when both tips were used with the constant contact technique, p = .294. However, participants detected drop-offs at a significantly higher percentage when they used the constant contact technique with the marshmallow roller tip (79.4%) than when they used the two-point touch technique with the marshmallow tip (63.2%), p < .001.

Conclusion: The constant contact technique used with a marshmallow roller tip (perceived as a less advantageous tip) was more effective than the two-point touch technique used with a marshmallow tip (perceived as a more advantageous tip) in detecting drop-offs.

Application: The findings of the study may help cane users and orientation and mobility specialists select appropriate cane techniques and cane tips in accordance with the cane user’s characteristics and the nature of the travel environment.
Hand and Finger Dexterity as a Function of Skin Temperature, EMG, and Ambient Condition
Authors: Chen Wen-Lin , Shih Yuh-Chuan , Chi Chia-Fen
Published: August 2010

Objective: This article examines the changes in skin temperature (finger, hand, forearm), manual performance (hand dexterity and strength), and forearm surface electromyograph (EMG) through 40-min, 11 °C water cooling followed by 15-min, 34 °C water rewarming; additionally, it explores the relationship between dexterity and the factors of skin temperature, EMG, and ambient condition.

Background: Hand exposure in cold conditions is unavoidable and significantly affects manual performance.

Method: Two tasks requiring gross and fine dexterity were designed, namely, nut loosening and pin insertion, respectively. The nested-factorial design includes factors of gender, participant (nested within gender), immersion duration, muscle type (for EMG), and location (for skin temperature). The responses are changes in dexterity, skin temperature, normalized amplitude of EMG, and grip strength. Finally, factor analysis and stepwise regression are used to explore factors affecting hand and finger dexterity.

Results: Dexterity, EMG, and skin temperature fell with prolonged cooling, but the EMG of the flexor digitorum superficialis remained almost unchanged during the nut loosening task. All responses but the forearm skin temperature recovered to the baseline level at the end of rewarming. The three factors extracted by factor analysis are termed skin temperature, ambient condition, and EMG. They explain approximately two thirds of the variation of the linear models for both dexterities, and the factor of skin temperature is the most influential.

Conclusion: Sustained cooling and warming significantly decreases and increases finger, hand, and forearm skin temperature. Dexterity, strength, and EMG are positively correlated to skin temperature. Therefore, keeping the finger, hand, and forearm warm is important to maintaining hand performance.

Application: The findings could be help- ful to building safety guidelines for working in cold environments.
Understanding the variability of vegetable fibres: a case study of harakeke (Phormium tenax)
Authors: Lowe Bronwyn J , Carr Debra J , McCallum Rua E , Myers Tom , Ngarimu-Cameron Roka , Niven Brian E
Published: August 2010

Fibre properties may be an important source of information to identify, conserve and protect intraspecific diversity within culturally significant fibre plants such as harakeke (Phormium tenax, New Zealand flax). Māori weavers recognise differences in whītau * (fibre aggregate prepared using traditional practices) extracted from leaves of different harakeke cultivars. However, tensile properties of fibre aggregates are reportedly highly variable. The aim of this study was to investigate variation in fibre aggregate physical and mechanical properties among leaves harvested from different fans within two bushes representing different cultivars of harakeke. Tenacity, extension to maximum load, specific modulus and specific energy to maximum load of fibre aggregates differed between the bushes, and also among leaves within each bush. Leaf width and thickness were weakly correlated with fibre aggregate properties suggesting that wider, thicker leaves yield tougher and more pliable fibre aggregates. Variability among leaves differed according to the property measured, and was highest for fibre aggregate length and lowest for specific energy to maximum load. Although fibre aggregate tenacity (or strength) is commonly used to compare intra and interspecific fibre properties, specific modulus, extension at maximum load and specific energy to maximum load were all more appropriate for identifying intraspecific differences in harakeke fibre properties.
Influence of wetting phenomenon on the characteristics of a sized yarn
Authors: Sejri Nejib , Harzallah Omar , Viallier Pierre , Ben Nasrallah Sassi
Published: August 2010

The aim of this work is to study the effect of the addition of a wetting agent to a size solution and to the water used for the pre-wetting to know if it is possible to reduce size content of the yarn with mechanical properties allowing a good ‘weavability’. The effect on the physical and mechanical characteristics of adding the wetting agent was examined. In the tensile test, as a result of adding the wetting agent to a size solution, an increase in the Young modulus of the yarn sized classically was induced, and a decrease with a pre-wetting technique. Concerning the bending rigidity, the same conclusion as for the tensile strength has been demonstrated by using the Kawabata unit. These deteriorations have been explained by using scanning electron microscopy. Indeed, the micrographs seem to show that the fibers of yarns sized with the pre-wetting technique are coated with the size film and not bridged to themselves with the size which explained the decrease of the mechanical properties. However this coating is not recommended in the sizing process.
Coexisting antistatic and water-repellent properties of polyester fabric
Authors: Shyr Tien-Wei , Lien Chin-Hsing , Lin Ai-Jing
Published: August 2010

It is desirable for textiles to prevent static charges and to repel water. This work used nano-silver antistatic finish and fluorine water-repellent finish in order to determine whether it is possible for antistatic and water-repellent properties to coexist on a single sample of polyester fabric. The antistatic and water-repellent fabric finishes were each tested singly first; both finishes were combined in each of three treatments, namely the one-bath, two-bath A, and two-bath B treatments. The antistatic and the water-repellent properties of the finished fabrics were evaluated by FTTS—FA—009 and AATCC 22 spray rating standards. The nano-silver and fluorochemical finishes individually showed high performance properties on polyester fabric. It was found that the order of the finishing processes has a significant effect on the antistatic and water-repellent properties of polyester fabric. The two-bath B process treated polyester fabric, first with 5 wt% nano-silver antistat and then with 3 wt% fluorine water-repellent. After 10 washings, the fabric finished with the two-bath B process was certified to FTTS—FA—009 A grade for its antistatic properties; it was certified to AATCC 22 spray rating 90 grade for its water-repellent qualities.
Are Patients’ Initial Experiences at the Diagnosis of Type 2 Diabetes Associated With Attitudes and Self-management Over Time?
Authors: Polonsky William H. , Fisher Lawrence , Guzman Susan , Sieber William J. , Philis-Tsimikas Athena , Edelman Steven V.
Published: August 2010

Objective

The purpose of this study was to investigate patients’ experiences when diagnosed with type 2 diabetes and diabetes-related distress and self-management years later.

Method

One hundred seventy-nine adults with type 2 diabetes, 1 to 5 years after diagnosis, completed a questionnaire assessing what they were told and what was recommended at diagnosis as well as current diet, physical activity, and diabetes distress.

Results

Most patients (60%) expressed confidence in their health care provider (HCP) at diagnosis, but 30% reported that a clear action plan was not communicated. Current diabetes distress was significantly lower among those who reported being reassured at diagnosis that diabetes could be managed successfully and had developed a clearer action plan with their HCP. Patients’ current dietary behaviors were significantly better among those receiving a clearer action plan at diagnosis.

Conclusion

Patients’ retrospective reports of reassuring HCP messages when diagnosed, along with the presentation of a clear action plan, are associated with less diabetes distress and better self-management at 1 to 5 years after diagnosis.

Practical implications

Findings suggest a long-lasting impact on patients’ attitudes and behaviors when the diagnosis of type 2 diabetes is delivered clearly, a sense of hope is provided, and a specific care plan is put forward.
Abiomed Impella ® 2.5 patient transport: lessons learned
Authors: Griffith Kevin E , Jenkins Eric
Published: August 2010

The Abiomed Impella ® 2.5 is a micro-axial flow, catheter-based left ventricular assist system (LVAS). Designed for percutaneous insertion into the femoral artery and positioned across the aortic valve, the Impella® is capable of pumping 2.5 liters of blood per minute from the patient’s left ventricle into the ascending aorta. Since United States Federal Food and Drug Administration clearance in June of 2008, use of the Impella® 2.5 has grown rapidly.

We operate at the center of a “hub-and-spoke” regional referral network that facilitates the transfer of patients in cardiogenic shock to our facility for definitive care. Based on our recent experience of transporting patients supported on the Impella® 2.5 system, we review system operation, pump position, monitoring, and recommendations for providing safe and efficient transport.
Detecting Blood Laboratory Errors Using a Bayesian Network
Authors: Le Quang A. , Strylewicz Greg , Doctor Jason N.
Published: August 2010

Objectives: To detect errors in blood laboratory results using a Bayesian network (BN), to compare results with an established method for detecting errors based on frequency patterns (LabRespond) and logistic regression model. Methods: In Experiment 1 and 2 using a sample of 5,800 observations from the National Health and Nutrition Examination Survey dataset, large, medium and small errors were randomly generated and introduced to liver enzymes (ALT, AST, and LDH) of the dataset. Experiment 1 examined systematic errors, while Experiment 2 investigated random errors. The outcome of interest was the correct detection of liver enzymes as “error” or “not error.” With the BN, the outcome was predicted by exploiting probabilistic relationships among AST, ALT, LDH, and gender. In addition to AST, ALT, LDH, and gender, LabRespond required more information on related analytes to achieve optimal prediction. We assessed performance by examining the area under the receiver operating characteristics curves using a 10-fold cross validation method, as well as risk stratification tables. Results: In Experiment 1, the BN significantly outperformed both LabRespond and logistic regression in detecting large (both at p < 0.001), medium ( p = 0.01 and p < 0.001, respectively), and small ( p = 0.03 and, p = 0.05, respectively) systematic errors. In Experiment 2, the BN performed significantly better than LabRespond and multinomial logistic regression in detecting large ( p = 0.04 and p < 0.001, respectively) and medium ( p = 0.05 and p < 0.001, respectively) random errors. Conclusion: A Bayesian network is better at detection and can detect errors with less information than existing automated models, suggesting that Bayesian model may be an effective means for reducing medical costs and improving patient safety.
Exploring Model Uncertainty in Economic Evaluation of Health Interventions: The Example of Rotavirus Vaccination in Vietnam
Authors: Kim Sun-Young , Goldie Sue J. , Salomon Joshua A.
Published: August 2010

Objective . Motivated by observed discrepancies between 2 published studies on the cost-effectiveness of rotavirus vaccination in Vietnam, the authors’ objectives were to illustrate a specific, systematic approach to assessing model (structure and process) uncertainty and to quantify explicitly the contributions of different sources of variation in the outputs of different studies that share the same research question. Methods . On the basis of a series of working definitions of key model elements, the authors developed 5 alternative computer simulation (state-transition) models of rotavirus disease. They examined how epidemiological outcomes and cost-effectiveness ratios associated with rotavirus vaccination would change as elements of model structure and modeling process were progressively modified. They also explicitly decomposed the relative contributions of different modeling elements to differences in the cost-effectiveness results between the 2 previous analyses motivating the present study. Results . The findings suggest that within the category of a static, deterministic, aggregate-level model, different choices in model structure and process lead to relatively modest differences in the estimated cost-effectiveness of rotavirus vaccination, but that intermediate epidemiologic outcomes vary more substantially depending on the choice of model structure. Conclusions . The authors caution against generalizing the quantitative results in this study beyond the present example but suggest that the approach presented here may serve as a template for other examinations of model uncertainty. As new research questions arise after the introduction of rotavirus vaccination programs, a reevaluation of model uncertainty is likely to be needed.
The complexity of innovation: A relational turn
Authors: Fløysand Arnt , Jakobsen Stig-Erik
Published: August 2010

Recent contributions within the system of innovation approach are marked by an instrumentalism that views innovation as a predictable and standardized process that in most aspects counters theories and empirical observations stressing the multilevel, spontaneous and complex features of innovation. Informed by the relational turn within economic geography this paper develops an alternative analytical framework. We do this stepwise: first, by elaborating on how innovation was originally defined within the systems of innovation approach; second, by outlining a relational based analytical framework based on the concept of social fields; and, finally, by demonstrating how it has been applied.
Human geographies of climate change: Landscape, temporality, and lay knowledges
Authors: Brace Catherine , Geoghegan Hilary
Published: August 2010

In this paper we bring together work on landscape, temporality and lay knowledges to propose new ways of understanding climate change. A focus on the familiar landscapes of everyday life offers an opportunity to examine how climate change could be researched as a relational phenomenon, understood on a local level, with distinctive spatialities and temporalities. Climate change can be observed in relation to landscape but also felt, sensed, apprehended emotionally as part of the fabric of everyday life in which acceptance, denial, resignation and action co-exist as personal and social responses to the local manifestations of a global problem.