bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Properties of Ti-Cr-Sn-Zr Alloys
Authors: Murayama Yonosuke , Sasaki Shuichi , Kimura Hisamichi , Chiba Akihiko
Published: January 2010

Low modulus β Ti alloys are attractive for biomedical application. This work examines the mechanical properties of Ti-Cr-Sn-Zr system alloys, especially the effect of the varying alloy composition on the microstructure, the Young’s modulus and the deformation mechanism.The Young’s modulus of the alloy varies with the composition, which variation is caused mainly from the competition between the meta-stable β phase and ω phase.The deformation modes of the Ti-Cr-Sn-Zr alloy, which are the mechanical twinning, the deformation by slip and the deformation-induced transformation, also change depending on the composition of the alloy. The minimum of the Young’s modulusof the Ti-Cr-Sn-Zr alloy in this experiment was shown in the composition where the microstructure of the alloy changes from the martensitic structure to the meta-stable β structure.
Mechanical Behavior Study of Plasma Sprayed Hydroxyapatite Coatings onto Ti6Al4V Substrates Using Scratch Test
Authors: Behnamghader Aliasghar , Najjar Denis , Iost Alain , Benayoun Stephane
Published: January 2010

Mechanical behavior and fracture mechanisms of plasma sprayed hydroxyapatite coatings on Ti-6Al-4V substrate were assessed taking into consideration two variables: the coating thickness and the substrate roughness. The results show that the specimens having a substrate arithmetic average roughness parameter Ra = 2.29 µm is favorable with respect to Ra = 1.23 µm. For coating thickness above 105 µm, cracks can be observed in the coating/substrate interface and the higher critical load Pc2 (used generally in comparative evaluation of adherence) decreases. A 90 µm coating thickness sprayed on a substrate having an arithmetic average roughness parameter Ra equal to 2.29 µm seems to be the best compromise between microstructure, mechanical resistance (high critical loads and fairly good contact quality) and long term stability in the physiological medium (low dissolution rate) for an orthopedic application.
Fabrication of Hollow Nano Particles of Metallic Oxides through Oxidation Process
Authors: Nakajima Hideo , Nakamura Ryusuke
Published: January 2010

The formation mechanisms of hollow metal oxide through the oxidation of several metal nanoparticles have been studied by transmission electron microscopy. For Zn, Al, Cu, Ni and Fe nanoparticles, hollow oxide nanoparticles were obtained as a result of vacancy aggregation in the oxidation processes. The formation of the hollow morphology is attributed to the faster outward diffusion of metal ions through the oxide layer in the oxidation processes. Further changes in morphology during the annealing of hollow Cu, Ni and Fe oxides at higher temperatures in air were examined.
Preparation of Silicon-Containing Poly(lactic acid)-Vaterite Hybrid Membranes
Authors: Obata Akiko , Wakita Takashi , Ota Yoshio , Kasuga Toshihiro
Published: January 2010

Microfiber meshes releasing a trace amount of silicon species were prepared by electrospinning silicon-doped vaterite (SiV) and poly(lactic acid) (PLA) hybrids for application to membranes for guided bone regeneration (GBR). A trace amount of silicon-species has been reported to enhance the mineralization and bone-forming abilities of osteogenic cells. The microfiber meshes prepared by electrospinning are regarded to be a useful candidate for the GBR membrane, because they have adequate flexibility and porosity for it. In this study, hydroxyapatite (HA)-forming abilities in simulated body fluid, silicon-releasabilities, compatibility with osteoblast-like cells of the prepared microfiber meshes were examined. The meshes were completely coated with HA after soaking in simulated body fluid for 1 day. The meshes coated with HA released 0.2 -0.7 mg/L of silicon species in a cell culture medium for 7 days. The cells elongated on the microfibers of the meshes and some of them entered the mesh after 1 day-culturing. The meshes are expected to provide an excellent substrate for bone regeneration and enhance bone-forming ability of the cells.
Morphological Analysis of Hydroxyapatite Particels Obtained by Different Methods
Authors: Rivera-Muñoz Eric M. , Velázquez-Castillo Rodrigo , Cabrera-Torres J.L.
Published: January 2010

Material science is playing an increasing role in bioengineering and biomedical sciences, aiming to develop new systems and materials capable of overcoming the highly demanding environment of a living organism. One of those materials, Hydroxyapatite (HAp), is the principal calcium phosphate present in the mineral phase of bone.
Hydroxyapatite-based materials have been used for dental and biomedical applications, and the control of morphology and structure at micro and nanoscale levels in the synthesis processes, is crucial for several of those applications.
Hydroxyapatite crystalline particles were obtained by the so-called sol-gel technique, in which silica gels induce the formation of apatite particles in a simulated body fluid at nearly 37°C, different chemical additives were used to control morphology and particle size, as previously reported by our group. Recently, the synthesis of HAp particles with similar morphologies obtained by different methods, have been reported by other groups. Differences and similarities in morphologies, as well as in the synthesis processes, are established in the present work, along with a discussion of possible crystal growth and assembly mechanisms, which lead to a better understanding of the particle growth processes, is included. This knowledge could be the basis for further synthesis methods aimed to obtain HAp nanostructures with a crystal preferential orientation.
Relevance of Static and Dynamic Recrystallizations on Austenite Grain Refinement in Nb-Mo Microalloyed Steels
Authors: Pereda Beatriz , López Beatriz , Rodriguez-Ibabe J.M.
Published: January 2010

Composite systems composed of nanocrystalline apatites and oligolactide-based polymer networks were prepared resulting in malleable and even injectable formulations which can be cured to compact materials at body temperature. Porous devices with inter-connective porosity were obtained after addition of suitable foaming agents to the composite mixtures. Setting time, porosity and mechanical properties of the composites can be properly adjusted by varying the educt composition. The determined compressive strengths and Young’s moduli of the porous composites perfectly match the mechanical characteristics of cancellous bone material. Preliminary in vitro cell culture experiments with compact composite materials demonstrated their good cytocompatibility. Based on these findings, the synthesized nano-structured composites represent promising candidates for the development of new biomaterials usable in hard tissue regeneration.
Study of Alpha-Beta Transformation in Ti-6Al-4V-ELI. Mechanical and Microstructural Characteristics
Authors: Tarín Pascual , Gualo Aurelio , Simón Atonio Garcia , Piris Nuria M. , Badía Jose Maria
Published: January 2010

In the Ti-6Al-4V-ELI alloy, the alpha phase is gradually transformed into the beta phase until beta-transus temperature ( 980°C) is reached, and the transformation is completed. It is important to identify the transformation kinetics to accomplish the solution heat treatments in which a phase alpha percentage remains unchanged. Kinetics and other transformation characteristics are evaluated, as well as their influence on subsequent cooling transformations, by differential and dilatometric thermal analysis, electric conductivity measurements, hardness measurements and metallographic observation, after performing controlled thermal treatments. Starting from the mill annealed condition, samples were heated at temperatures between 650-1000 °C for 1 hour, then water quenched and subsequently heated for aging, air cooled. Finally, the mechanical properties of samples heat treated were obtained.
Hydrothermal Modification of Titanium Surfaces for Controlling Osteointegration
Authors: Ueda Masato , Kinoshita Takahiro , Sasaki Yuumi , Ikeda Masahiko , Ogawa Michiharu
Published: January 2010

The combined chemical-hydrothermal synthesis of TiO2 and CaTiO3 films on pure Ti substrates was examined with a focus on film crystallinity and surface morphology. Pure Ti disks were chemically treated with H2O2/ HNO3 aqueous solutions at 353 K for 20 min in order to form a TiO2 gel layer on the surfaces. The samples were then hydrothermally treated in an autoclave at 453 K for 12 h or 24 h. Anatase-type TiO2 and perovskite-type CaTiO3 films with high crystallinity were obtained upon treatment with distilled water or aqueous NH3 and aqueous Ca(OH)2, respectively. Uniform, crack-free films were obtained. The surfaces showed excellent attachment of osteoblast-like MC3T3E1 cells in an incipient stage. Furthermore, the cells showed satisfactory proliferation, though at a slightly lower rate than on Ti. In addition, the samples were immersed in SBF (Simulated Body Fluid), adjusted to 310 K. A light hydroxyapatite (HAp) precipitate was observed on the unmodified Ti surface after 6 days of immersion. In contrast, precipitation was observed only after 2 to 4 days on the present oxide films. Thus, these oxide films are non-toxic and enhance the deposition of HAp.
Status of the Development of Creep Resistant Magnesium Materials for Automotive Applications
Authors: Kainer Karl Ulrich , Huang Yuan Ding , Dieringa Hajo , Hort Norbert
Published: January 2010

The present paper presents the development status of creep resistant magnesium materials. It reviews the creep deformation mechanisms of magnesium alloys. Based on these mechanisms, several effective approaches to improve the creep resistance are discussed, including alloying, microstructural control and the development of new monolithic alloys and composites.
Experimental Techniques to Evaluate In Vitro Trabecular Bone Properties and Emerging Numerical Model
Authors: Blangino Eugenia , Irastorza Ramiro M. , Valente Sergio , Vericat Fernando
Published: January 2010

Economical reasons to research and develop new materials are very strong and the main market for biotechnology is human health. Bone is one of the most studied biological material; data and models at different organization levels describe relevant features needed in different applications. Depending on the type of bone, the anatomical location, the human population considered and the level taken into account, the descriptions can differ substantially. In this work, we present a set of properties (mechanical and architectural ones) measured on fresh trabecular bones samples that were extracted from femur heads of live donors with hip total replacement. Standard procedures to preserve the samples were followed. Engineering and clinical tests were performed and custom-built tools were made to adapt the available equipment.
Comparison of the In Vivo Degradation Progress of Solid Magnesium Alloy Cylinders and Screw-Shaped Magnesium Alloy Cylinders in a Rabbit Model
Authors: von der Höh Nina , Bormann Dirk , Lucas Arne , Thorey Fritz , Meyer-Lindenberg Andrea
Published: January 2010

Resorbable magnesium alloy implants for osteosynthetic surgery would be advantageous to common implants of titanium or surgical steel as a second surgery for implant removal would become unnecessary. To influence the degradation progress, surface modifications are sensible. As plates and screws were used to stabilize fractures, the degradation behavior of threaded cylinders is of particular interest. Therefore each eight solid MgCa0.8 alloy cylinders (3 x 5 mm) with smooth and sandblasted surface, respectively, and eight screw-shaped, threaded MgCa0.8 cylinders (thread pitch 1.25 mm, length 5 mm) were inserted into the medial femoral condyle of adult New Zealand White rabbits. Implantation periods were three and six months, within which the animals were examined daily. To evaluate a possible gas generation radiographs were taken weekly. After euthanasia the bone-implant-compound was scanned in a µ-computed tomograph (µCT80, ScancoMedical). All implants were well tolerated. Smooth implants degraded slowly. The cross sectional area did not reduce obviously after three months implantation duration and only mildly after six months. Sandblasted implants showed the fastest degradation progress after both implantation periods with the most obvious generation of gas. Threaded cylinders revealed pitting corrosion at the thread pitches. They degrade faster than smooth implants but slower than sandblasted cylinders. In summary, surface modification influences the degradation behavior of resorbable magnesium alloy implants. Contrary to common materials, smooth surfaces seem to be favorable. Thread pitches of screw-shaped implants show pitting corrosion. To what extend this result affects future applications of resorbable screws has to be examined in further investigations.
Synchrotron Radiation and Neutron Diffraction Study of Hydroxyapatite in Bone at the Interface with Implant
Authors: Benmarouane Abdelilah , Citterio-Bigot Helene , Geandier Guillaume , Hansen T. , Millet Pierre , Lodini Alain
Published: January 2010

The quantitative evaluation of the preferential orientation of crystallites by the synchrotron and neutron diffraction techniques during regeneration at the interface with implant gives a good prediction of the mechanical properties of the bone. During the process of bone healing after implantation, the speed and quality of regeneration is affected by the nature of the implant surface. Titanium alloy (Ti-Al-4V) is currently coating with the hydroxyapatite (HAp), Ca10(PO4)6 (OH)2, in order to obtain a stable and functional direct connection between bone and implant. At the interface implant-bone, the new bone reconstituted after implantation must have the same mechanical properties of bone in order to accept the implant. Therefore, it is necessary to study by means of two non destructive techniques: neutron diffraction and synchrotron radiation, the crystal growth and texture of this new bone crystals reconstituted at the interface.
Study of the S Phases Formed on Plasma-Nitrided Austenitic and Ferritic Stainless Steels
Authors: Gontijo L.C. , Machado R. , Casteletti L.C. , Kuri S.E. , Nascente Pedro A.P.
Published: January 2010

An expanded austenite layer is formed on the surfaces of austenitic stainless steels that are nitrided under low-temperature plasma. This S phase is an iron alloy metastable phase supersaturated with nitrogen. We have identified a similar expanded ferrite or ferritic S phase for nitrided ferritic (BCC) stainless steels. Samples of austenitic AISI 304L and AISI 316L and ferritic AISI 409L stainless steels were plasma-nitrided at 350, 400, 450 and 500°C, and the structural and corrosion characteristics of the modified layers were analyzed by X-ray diffraction (XRD) and electrochemical tests. For the austenitic AISI 304L stainless steel, the results showed that a hard S phase layer was formed on the surface, without corrosion resistance degradation, by using low plasma temperatures (350 and 400°C). A similar behavior was observed for the austenitic AISI 316L stainless steel: the modified layers formed at 350 and 400°C were constituted mainly by the S phase. Plasma-nitriding treatment of the ferritic AISI 409L stainless steel caused the formation of a layer having high amount of nitrogen. XRD measurements indicated high strain states for the modified layers formed on the three stainless steels, being more pronounced for the ferritic S phase.
Microstructure and Mechanical Properties of Cr-Al-B-N Coatings Prepared by Reactive D.C. and R.F. Co-Sputtering
Authors: Nose Masateru , Kawabata Tokimasa , Ueda Shouhei , Fujii Kaname , Matsuda Kenji , Ikeno Susumu
Published: January 2010

The current study was undertaken to investigate the synthesis of CrAlN/BN composite coatings having super high hardness by a reactive co-sputtering using CrAl alloy and BN targets and gaseous mixture of Ar+N2, in order to eliminate the possible formation of boride bonding. CrAlN or BN phase was deposited by pulsed d.c.- and r.f.- sputtering, respectively. Plastic hardness, Hpl, and Young’s modulus, E*, of the coatings increased with BN phase ratio, reaching a maximum value of ~46 GPa and 390 GPa at ~8 vol. % of BN phase; and then decreased to ~20GPa and ~300GPa at ~18 vol.%, respectively. Only B1 structured Cr(Al)N phase was found in XRD and SAED analysis. XPS and TEM/HRTEM results revealed that the CrAlN/8vol%BN coating consists mostly of CrAlN and BN phase, which exists as an amorphous like phase among the CrAlN grains. The CrAlN/8vol%BN coating has a kind of nanocomposite structure and the super high hardness over 40 GPa is probably due to this structure.
Electrodeposition of Ferromagnetic Metal Nanowires
Authors: Ohgai Takeshi , Takao Keizo , Mizumoto Masayuki , Kagawa Akio , Tanaka Yoshitomo , Sumita Shigekazu
Published: January 2010

Ni-Fe alloy films and nanowires were fabricated using electrodeposition technique. The cylindrical shape of nanowires was precisely transferred from the nanochannels of membrane filters and the aspect ratio reached to around 60. Coercive force in in-plan direction of Ni-Fe alloy films decreased to ca. 1 Oe with increasing Fe content in deposits while, in perpendicular direction, the films were hardly magnetized. Magnetic hysteresis loops revealed that the nanowires were spontaneously magnetized to the long axis direction and the coercive force reached to ca. 200 Oe.
Surface Protection of Magnesium Alloys via Pack Cementation Coatings with Aluminum Powder and Chlorides
Authors: Park Joon Sik , Kim J.M. , Kim H.Y. , Kang C.S. , Choi S.W.
Published: January 2010

Magnesium alloys have been received an attention for structural applications due to their low density compared to other alloys, and intensive studies have been focused for enhancing mechanical strength and surface protection as well. Especially, for environmental reasonings, coating processes in a dry condition have been recently received a great attention. In this study, diffusion coatings via Al powders with an aluminum chloride activator have been investigated in order to examine surface protection effect on magnesium alloys. The commercial AZ31 magnesium alloy has been subjected to diffusion coatings in an Al alloy powder for various time frames. An intermediate layer of Mg17Ag12 was successfully synthesized via diffusion annealing. The underlying mechanisms for surface layer formation are discussed together with growth kinetics and microstructural observations
Change in Surface States of Amorphous Carbon Nitride Films after Exposure to Oxygen Plasma
Authors: Aono Masami , Kikuchi Shunsuke , Kitazawa Nobuaki , Watanabe Yoshihisa
Published: January 2010

Amorphous carbon nitride (a-CNx) thin films were deposited by rf-reactive sputtering method using a graphite target, and after deposition the films were exposed to oxygen plasma. The effect of the oxygen plasma exposure on the morphology and chemical bonding states of the film surface has been studied. Film composition and the chemical bonding states were analyzed by X-ray photoelectron spectroscopy (XPS). Film surface was observed by atomic force microscopy (AFM). AFM observations have revealed that the as-deposited film surface is uniformly covered with particle-like features in the early stage of deposition and the surface changes to be covered with broccoli-like features with increasing the deposition time and correspondingly the surface roughness increases, while after exposure to oxygen plasma, the film surface was etched selectively and the surface roughness increases with the plasma exposure time. It should be noted that the etching behavior depends on the film deposition temperatures. XPS studies have shown that after exposure to oxygen plasma the change in the bonding states in the films prepared at 853 K is different from that in the films prepared at RT.
Mechanism of Whisker Growth Suppression by Lead Co-Deposition on Electroplated Tin Film
Authors: Hino Makoto , Murakami Koji , Mitooka Yutaka , Takamizawa Masao , Naka Toshihide , Nakai Kiyomichi
Published: January 2010

This study investigated the effect of lead on the whisker growth of a tin film that was the electrodeposited on a phosphor bronze substrate. Subsequent FE-AES observation revealed that the whisker growth on the electrodeposited tin film varied depending on the morphology of the oxide film. The whisker growth was suppressed concomitantly with thinness or fragility of the oxide film formed on the tin deposits. The whisker growth was also suppressed concomitantly with the lead co-deposition in the tin deposits. In the Sn/Sn-Pb multilayer, because the lead between the tin film and the substrate was transferred to the surface, the whisker growth was also suppressed. This whisker growth suppression effect caused by the existence of a lead in the tin deposits was attributed to the oxide film thinning and embrittlement, depending on the lead transfer to the surface at room temperature.
Microstructure and Properties of Friction Surfaced Stainless Steel and Tool Steel Coatings
Authors: Khalid Rafi H. , Janaki Ram G.D. , Phanikumar G. , Rao K. Prasad
Published: January 2010

Friction surfacing is a novel solid state surface coating process with several advantages over conventional fusion welding based surfacing processes. In this work, austenitic stainless steel (AISI 310) and tool steel (H13) coatings were friction deposited on mild steel substrates for corrosion and wear protection, respectively. Microstructural studies were carried out by using optical and scanning electron microscopy. Shear tests and bend tests (ASTM A264) were conducted to assess the integrity of the coatings. This study brings out the microstructural features across the coating/substrate interface and its mechanical properties, showing good metallurgical bonding between stainless steel and tool steel coating over mild steel.
Control of Polymorphism and Mass-Transfer in Al2O3 Scale on Alumina Forming Alloys
Authors: Kitaoka Satoshi , Matsudaira Tsuneaki , Wada Masashi , Kuroyama Tomohiro
Published: January 2010

The transformation from metastable polymorphs to stable alpha-Al2O3 in the scale formed on a CoNiCrAlY alloy is accelerated under lower oxygen partial pressure (PO2), where both Al and Cr in the alloy are simultaneously oxidized, resulting in the formation of a dense and monolithic alpha-Al2O3 scale. Under higher PO2, where all components of the alloy are oxidized, the transformation is retarded and (Co,Ni)(Al,Cr)2O4 is also produced. The oxygen permeability in polycrystalline alpha-Al2O3 wafers exposed to steep oxygen potential gradients is evaluated at high temperatures to investigate the complicated mass-transfer phenomena through the scale formed on the alloy. The diffusion of Al and O species, which are responsible for the oxygen permeation along the grain boundaries of Al2O3, is dependent on the formation of an oxygen potential gradients. For Lu-doped Al2O3 polycrystals, it was found that Lu depressed the mobility of oxygen, but did not directly influence the migration of Al.
Microstructure and Thermal Diffusivity of Micro- and Nano-Sized YSZ
Authors: Moskal Grzegorz
Published: January 2010

The thermal barrier coatings (TBC) enable to lower temperature (at approx. 170°C) of operating elements in a hot section of gas turbine to a range, which enables to operate for a long time in conditions of high temperature influence and prolongs operation of them even three or four times. Usually, the TBC coverings are constructed of four layers:
• superalloys on a base of nickel;
• outer ceramic zone, from which low thermal conduction is required. It is, in most cases, ZrO2 oxide stabilized with Y2O3 (YSZ – yttria stabilized zirconia), material of one of lowest values of thermal conductivity in high temperature of a rank 2.3 Wm-1K-1 in 1000°C for 100% density and thermal expansion of a rank 11×10-6°C-1, what enables to reduce thermal stresses. Usually, thickness of an outer ceramic layer is within a range 250-375μm;
• bond coat of a type Ni(Co)CrAlY or diffusion layer of a type (Ni,Pt)Al;
• layer of barrier oxides, accrueting as a result of temperature growth TGO (thermally grown oxide).
In the present study characterization of conventional micro-sized YSZ powders stabilized by 8% of yttria and in comparison nano-sized YSZ will be presented. The tests performed showed that the monoclinic phase content in the nanocrystalline powder is approx. 8.8%, and approx. 7.5% in the conventional powder. The chemical composition analysis and test of powder microstructure were also performed. Carbon, sulphur and gas nitrogen contents were determined and the results received were similar. The surface morphology and powder microstructure on the cross-sections were also characterized. The standard powder with spherical shape and relatively smooth surface is predominant. The internal structure is characterized by the presence of tiny sintered particles and low porosity. The nanocrystalline powder tests showed the presence of particles in the form of tiny polyhedrons with bimodal size distribution of particles (approx. 1μm and 10μm).
Experimental Study on Drilling Process of CFRP Composite Laminate
Authors: Azhari Azmir , Nair Sivasankaran Praveena , Hamedon Z.
Published: January 2010

This thesis deals with carbon fiber reinforced plastics (CFRP) composites, an advanced material which is widely used in manufacturing aircrafts because of their unique mechanical and physical properties. The research mainly involved drilling of CFRP. This study is focused on analyzing the thrust force and delamination against drilling parameters namely feed rate, spindle speed and type of tool materials. Also, the optimal parameters were chosen using an optimization method called D optimal. It was observed that the higher the feed rate and spindle speed employed, the higher the thrust force and delamination occur. The split point fibre (SPF) drill gave the lowest values of thrust force and delamination. Based on the optimal parameters, a verification test was conducted and the prediction error was 2.3% and 5.6% for thrust force and delamination respectively. This shows, that the optimal parameters obtained is reliable as it could improve the process considerably. The results of this study could be used as a reference for further research and studies on drilling of CFRP.
Hierarchical Structured Nanomaterial Fabricated by Nanopowder Process: Nanopowder Agglomerate Sintering
Authors: Lee Jai Sung , You W. K. , Cha B. H.
Published: January 2010

The key concept of nanopowder agglomerate sintering (NAS) process is based on the optimization of structure design and full density processing of nanopowder into nanostructured micro-components. The kinetics of NAS process is characteristic of being controlled by material transport through hierarchical interface structures of nanopowder agglomerates. Through optimal design of those hierarchical interfaces such as nano grain boundary and agglomerate boundary, thus, full density nanopowder materials can be fabricated by pressureless sintering. In this paper we overview recent studies on the role of hierarchical interfaces for processing of full density nanopowder materials.
Urine Proteome Scans Uncover Total Urinary Protease, Prostaglandin D Synthase, Serum Amyloid P, and Superoxide Dismutase as Potential Markers of Lupus Nephritis
Authors: Wu Tianfu , Fu Yuyang , Brekken Deirdre , Yan Mei , Zhou Xin J. , Vanarsa Kamala , Deljavan Nima , Ahn Chul , Putterman Chaim , Mohan Chandra
Published: January 2010

To identify potential biomarkers in immune-mediated nephritis, urine from mice subjected to an augmented passive model of anti-glomerular basement membrane (GBM)-induced experimental nephritis was resolved using two-dimensional gels. The urinary proteome in these diseased mice was comprised of at least 71 different proteins. Using orthogonal assays, several of these molecules, including serum amyloid P (SAP), PG D synthase, superoxide dismutase, rennin, and total protease were validated to be elevated in the urine and kidneys of mice during anti-GBM disease, as well as in mice with spontaneously arising lupus nephritis. Among these, urinary protease was the only marker that appeared to be exclusively renal in origin, whereas the others were partly serum-derived. Longitudinal studies in murine lupus demonstrated that total urinary protease had better predictive value for histologically active nephritis (r = 0.78) compared with proteinuria (r = −0.04), azotemia (r = 0.28), or the other markers examined, whereas urine SAP emerged as the single most predictive marker of histological glomerulonephritis. Collectively, these studies uncover total urinary protease, PG D synthase, SAP, and superoxide dismutase as novel biomarkers of anti-GBM disease and lupus nephritis, with stronger correlation to renal disease compared with currently employed biomarkers. These findings could have important diagnostic and prognostic ramifications in the management of these renal diatheses.
Immunoregulatory Properties of Mouse Limbal Stem Cells
Authors: Holan Vladimir , Pokorna Katerina , Prochazkova Jana , Krulova Magdalena , Zajicova Alena
Published: January 2010

Stem cells have been demonstrated in nearly all adult mammalian tissues and play a vital role in their physiological renewal and healing after injury. Due to their irreplaceable role in tissue repair, these cells had to develop mechanisms protecting them from deleterious inflammatory immune reactions and ensuring their increased resistance to various apoptosis-inducing agents. In this study, we demonstrate that a population of mouse limbal cells highly enriched for cells expressing markers and charateristics of limbal stem cells (LSCs) suppresses in a dose-dependent manner the proliferation of lymphocytes elicited by mitogens or TCR-triggering and significantly inhibits the production of proinflammatory cytokines by activated T cells. The suppression was mediated by soluble factor(s) and did not affect early cell activation. LSCs were even more suppressive than mesenchymal stem cells or natural regulatory T cells. In addition, the cells expressing markers and characteristics of LSC had significantly higher levels of mRNA for Fas ligand and for the antiapoptotic molecules Mcl-1, XIAP, and survivin than other limbal cell populations. LSCs were also more resistant to staurosporin-induced apoptotic cell death and to cell-mediated cytotoxic reaction than other limbal cells. Collectively, these results suggest that SC isolated from fresh adult limbal tissue possess immunomodulatory properties and inhibit proinflammatory immune reactions. Simultaneously, these cells express high levels of mRNA for antiapoptotic molecules, which can protect them against cell-mediated cytotoxic reactions and various apoptosis-inducing agents.
So mechanical or routine: The not original in Feist
Authors: Warner Julian
Published: January 2010

The United States Supreme Court case of 1991, Feist Publications, Inc. v. Rural Tel. Service Co., continues to be highly significant for property in data and databases, but remains poorly understood. The approach taken in this article contrasts with previous studies. It focuses upon the “not original” rather than the original. The delineation of the absence of a modicum of creativity in selection, coordination, and arrangement of data as a component of the not original forms a pivotal point in the Supreme Court decision. The author also aims at elucidation rather than critique, using close textual exegesis of the Supreme Court decision. The results of the exegesis are translated into a more formal logical form to enhance clarity and rigor.

The insufficiently creative is initially characterized as “so mechanical or routine.” Mechanical and routine are understood in their ordinary discourse senses, as a conjunction or as connected by AND, and as the central clause. Subsequent clauses amplify the senses of mechanical and routine without disturbing their conjunction.

The delineation of the absence of a modicum of creativity can be correlated with classic conceptions of computability. The insufficiently creative can then be understood as a routine selection, coordination, or arrangement produced by an automatic mechanical procedure or algorithm. An understanding of a modicum of creativity and of copyright law is also indicated.

The value of the exegesis and interpretation is identified as its final simplicity, clarity, comprehensiveness, and potential practical utility.
Mechanisms for intensification and maintenance of numerically simulated dust devils
Authors: Ohno Hiroshi , Takemi Tetsuya
Published: January 2010

A large eddy simulation (LES) of a well‐developed convective boundary layer (CBL) under no mean wind condition was performed with the Weather Research and Forecasting model in order to investigate the mechanisms for the intensification and maintenance of dust devils. By examining intense vortices from high temporal‐frequency outputs, it was found that most of the intense vortices are intensified through the merger of multiple vortices. Moreover, such a significantly intense vortex was maintained and more enhanced by additionally merging small‐scale vortices and tilting horizontal vortices at boundaries of convective cells. Copyright © 2010 Royal Meteorological Society
Synthesis of the proteinase inhibitor LEKTI domain 6 by the fragment condensation method and regioselective disulfide bond formation
Authors: Vasileiou Zoe , Barlos Kostas K. , Gatos Dimitrios , Adermann Knut , Deraison Celine , Barlos Kleomenis
Published: January 2010

Proteinase inhibitors are of high pharmaceutical interest and are drug candidates for a variety of indications. Specific kallikrein inhibitors are important for their antitumor activity and their potential application to the treatment of skin diseases. In this study we describe the synthesis of domain 6 of the kallikrein inhibitor Lympho‐Epithilial Kazal‐Type Inhibitor (LEKTI) by the fragment condensation method and site‐directed cystine bridge formation. To obtain the linear LEKTI precursor, the condensation was best performed in solution, coupling the protected fragment 1‐22 to 23‐68. This method yielded LEKTI domain 6 of high purity and equipotent to the recombinantly produced peptide. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94: 339–349, 2010.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Corticosterone exerts immunostimulatory effects on macrophages via endoplasmic reticulum stress
Authors: Zhou J-Y , Zhong H-J , Yang C , Yan J , Wang H-Y , Jiang J-X
Published: January 2010

Background

Glucocorticoids are the central effector hormones for the hypothalamic–pituitary–adrenal axis. However, the effects of endogenous glucocorticoids on the immune system are not understood completely.

Methods

Macrophage function (adherence, chemotaxis and cytokine production) was assessed in the presence of increasing concentrations of corticosterone. The role of endoplasmic reticulum (ER) stress in corticosterone immunoregulation was determined with thapsigargin and plasmid pGCL-GFP-siXBP1. Mifepristone was used to determine the role of glucocorticoid receptor in the corticosterone-induced ER stress response.

Results

Corticosterone exerted immunostimulatory effects on macrophage function at low concentrations. No effects were observed at high concentrations in the absence of immunological stimulation. Low-dose corticosterone induced ER stress, which was correlated to the corticosterone immunostimulatory activities. Expression of X box-binding protein (XBP) 1, but not activating transcription factor 6, was significantly increased at both mRNA and protein levels only in the presence of low-dose corticosterone. Inhibition of XBP1 expression with small interfering RNA significantly inhibited the corticosterone immunostimulatory effects. In addition, pretreatment of macrophages with mifepristone significantly inhibited the expression of glucose response protein 78 and XBP1 in macrophages by low-dose corticosterone.

Conclusion

At low concentrations, endogenous glucocorticoids exert immunostimulatory actions on macrophages. The underlying mechanisms may be correlated to ER stress via the glucocorticoid receptor, in which XBP1 plays an important role.
Risk factors and incidence of postoperative delirium in elderly patients after elective and emergency surgery
Authors: Ansaloni L , Catena F , Chattat R , Fortuna D , Franceschi C , Mascitti P , Melotti R M
Published: January 2010

Background

This study evaluated the incidence of postoperative delirium (POD) in elderly patients undergoing general surgery, the risk factors associated with POD, and its impact on hospital stay and mortality.

Methods

Patients aged over 65 years who had emergency or elective operations were eligible for this case–control study. Risk factors significantly associated with POD using univariable analysis were entered into multivariable analysis, to establish those independently associated with POD.

Results

A total of 351 patients (357 admissions) were enrolled in the study. The incidence of POD was 13·2 per cent (17·9 per cent for emergency operations). Independent variables associated with POD were: age above 75 years, co-morbidity, preoperative cognitive impairment, psychopathological symptoms and abnormal glycaemic control. Median length of hospital stay was 21 (range 1–75) days for patients with POD versus 8 (range 1–79) days for control patients (P < 0·001). The hospital mortality rate was 19 and 8·4 per cent respectively (P = 0·021).

Conclusion

The incidence of POD is high in elderly patients for both emergency and elective surgery, leading to an increase in hospital stay and perioperative mortality. To minimize POD, associated risk factors of co-morbidity, cognitive impairment, psychopathology and abnormal glycaemic control must be identified and treated.
Meta-analysis of the effect of peritoneal lavage on survival in experimental peritonitis
Authors: Qadan M , Dajani D , Dickinson A , Polk H C
Published: January 2010

Background

Morbidity and mortality associated with bacterial peritonitis remain a challenge for contemporary surgery. Despite great surgical improvements, death rates have not improved. A secondary debate concerns the volume and nature of peritoneal lavage or washout—what volume, what carrier and what, if any, antibiotic or antiseptic?

Methods

A literature search of experimental studies assessing the effect of peritoneal lavage following peritonitis was conducted using Medline, EMBASE and Cochrane databases. Twenty-three trials met predetermined inclusion criteria. Data were pooled and relative risks calculated.

Results

In an experimental peritonitis setting a mortality rate of 48·9 per cent (238 of 487) was found for saline lavage compared with 16·4 per cent (106 of 647) for antibiotic lavage (absolute risk reduction (ARR) 32·5 (95 per cent confidence interval (c.i.) 27·1 to 37·7) per cent; (P < 0·001). An ARR of 25·0 (95 per cent c.i. 17·9 to 31·7) per cent P < 0·001) was found for the use of saline compared with no lavage at all. The survival benefit persisted regardless of systemic antibiotic therapy. Antiseptic lavage was associated with a very high mortality rate (75·0 per cent).

Conclusion

Pooled data from studies in experimental peritonitis demonstrated a significant reduction in mortality with antibiotic lavage.
Diagnostic value of p16INK4A, Ki‐67, and human papillomavirus L1 capsid protein immunochemical staining on cell blocks from residual liquid‐based gynecologic cytology specimens
Authors: Yu Li , Wang Liantang , Zhong Juemin , Chen Shangwu
Published: January 2010

BACKGROUND:

This study was conducted to evaluate the reliability and role of cell block preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix and to improve the value of cell block preparations in diagnosing and predicting the prognosis of cervical lesions through immunostaining of p16INK4A (p16), Ki‐67, and human papillomavirus (HPV) L1 capsid protein (HPV L1).

METHODS:

In total, 138 specimens were diagnosed on liquid‐based cytology (LBC) and cell block preparations, and 63 specimens were subjected subsequently to tissue follow‐up and immunostaining for p16, Ki‐67, and HPV L1 on cell block sections.

RESULTS:

In 42 specimens that were diagnosed as low‐grade squamous intraepithelial lesion, high‐grade squamous intraepithelial lesion (HSIL), and squamous cell carcinoma (SCC) on cell blocks, 38 specimens (90.5%) were confirmed by histopathologic reports, and there was slightly better than 81.6% agreement between LBC and tissue follow‐up. Immunointensity and cells that were positive for p16 were enhanced according to increased pathologic grade and differed statistically between cervical intraepithelial neoplasia 1 (CIN‐1) and CIN‐2/CIN‐3 as well as SCC. The positive rates of HPV L1 decreased gradually according to the severity of cervical neoplasia, and HPV L1/p16 expression patterns were related to the severity of cervical lesions.

CONCLUSIONS:

The cell block preparation technique was complementary to LBC, and the authors concluded that the application of LBC combined with cell block preparations may improve the diagnostic accuracy of cytology. Immunostaining for p16 and Ki‐67 on cell block preparations can help to improve the diagnostic accuracy of HSIL and SCC. A combined expression pattern of p16 and HPV L1 may serve as a valuable index for predicting prognosis and follow‐up of cervical dysplastic lesions. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.
Ultrafast Decay of the Excited Singlet States of Thioxanthone by Internal Conversion and Intersystem Crossing
Authors: Angulo Gonzalo , Grilj Jakob , Vauthey Eric , Serrano‐Andrés Luis , Rubio‐Pons Òscar , Jacques Patrice
Published: January 2010

The experimental ultrafast photophysics of thioxanthone in several aprotic organic solvents at room temperature is presented, measured using femtosecond transient absorption together with high‐level ab initio CASPT2 calculations of the singlet‐ and triplet‐state manifolds in the gas phase, including computed state minima and conical intersections, transition energies, oscillator strengths, and spin–orbit coupling terms. The initially populated singlet ππ* state is shown to decay through internal conversion and intersystem crossing processes via intermediate nπ* singlet and triplet states, respectively. Two easily accessible conical intersections explain the favorable internal conversion rates and low fluorescence quantum yields in nonpolar media. The presence of a singlet–triplet crossing near the singlet ππ* minimum and the large spin–orbit coupling terms also rationalize the high intersystem crossing rates. A phenomenological kinetic scheme is proposed that accounts for the decrease in internal conversion and intersystem crossing (i.e. the very large experimental crescendo of the fluorescence quantum yield) with the increase of solvent polarity.
A load balancing energy efficient clustering algorithm for MANETs
Authors: Safa H. , Mirza O.
Published: January 2010

Nodes in mobilead hocNetworks (MANETs) are characterized by their limited resources. Hence, the concept of clustering was introduced to allow spacial reuse of bandwidth and to minimize routing overhead. However, node mobility perturbs the stability of the network and affects the performance of other protocols such as scheduling, routing, and resource allocation, which makes re‐clustering the network to maintain up‐to‐date information at each node unavoidable. Consequently, clustering models for MANETS should be carefully designed while taking into consideration the fact that mobile nodes are energy constrained. In this paper, we propose a dynamic energy‐efficient clustering algorithm that prolongs the network lifetime by electing cluster‐heads taking into consideration, in addition to other parameters such as mobility, their residual energies and making them dynamically monitor their energy consumption to either diminish the number of their cluster‐members or relinquish their roles. We have evaluated the performance of the proposed clustering model and compared it with other related clustering approaches found in the literature. Obtained results show the efficiency of the proposed algorithm. Copyright © 2010 John Wiley & Sons, Ltd.
A zone‐control induction heating (ZCIH) system for semiconductor processing
Authors: Fujita Hideaki , Ozaki Kazuhiro , Uchida Naoki
Published: January 2010

This paper proposes a new induction heating technology capable of controlling a precise exothermic distribution, which is termed zone‐control induction heating (ZCIH). The ZCIH system consists of two or more sets of a high‐frequency inverter unit and a work coil. The inverter units control the phase angle of the coil current to be in phase with each other. The ZCIH has the capability of operation with the mutual inductance, and enables locating the coils as close as possible. As a result, the ZCIH technology makes it possible to achieve rapid heating performance with extremely precise exothermic distribution. This paper presents experimental results of a 150‐kW six‐zone ZCIH system for semiconductor heat processing. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(1): 37–45, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.20908
Characteristics of creeping discharge developed in narrow gap on a filamentous backside electrode
Authors: Hirata Tomoyuki , Koga Mitsumasa , Ueno Hideki , Nakayama Hiroshi
Published: January 2010

We describe the characteristics of a creeping discharge developed in a narrow gap with a backside electrode, under microsecond pulse voltage application. In a gas mixture of 3% SF6in N2, the flashover voltage at pressures of 0.2 and 0.3 MPa decreased by approximately 5% compared to that of 0.1 MPa when using both a filamentous straight backside electrode and a filamentous curved backside electrode. V‐characteristics with decreased flashover voltage were obtained with SF6mixtures in N2. We obtained V‐characteristics of the flashover voltage for SF6concentrations in the range ofD=3 to 100% for a filamentous backside electrode. The flashover voltages obtained with a filamentous straight backside electrode were higher than those obtained with a filamentous curved backside electrode. From corona observation using an ultra‐high‐speed camera, it was found that the flashover is generated along the backside electrode. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(1): 1–9, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20955
Synthesis of Three‐Quarter‐Sphere‐Like γ‐AlOOH Superstructures with High Adsorptive Capacity
Authors: Zhu You , Hou Hongwei , Tang Gangling , Hu Qingyuan
Published: January 2010

Three‐quarter‐sphere‐like γ‐AlOOH superstructures were successfully fabricated by a simple hydrothermal route exploiting the layered hydroxide structure. Several techniques such as X‐ray diffraction (XRD), FTIR spectroscopy, field‐emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), DSC thermal analysis, and nitrogen adsorption/desorption measurements were used to characterize the products. The possible formation mechanism of the three‐quarter‐sphere‐like structure was proposed and discussed. The γ‐AlOOH superstructures have high Brunauer–Emmett–Teller (BET) surface area and high adsorptive capacity. On the basis of these properties, they could be potentially used for removing chromium ions from highly toxic pollutant solutions and harmful tobacco‐specific nitrosamines (TSNAs) from cigarette smoke.