bluuebunny/crossref_metadata_2025 huggingface dataset:
New Titanium Alloy of Ti-Fe-O-N for Dental Implant
Authors: Hashimoto Kimio , Kawahara Dai , Toshimori Yukiko , Hayakawa Masahide , Sakashita Hisato , Kawahara Haruyuki
Published: March 2009

Ti-6Al-4V alloy (Ti-Al-V) is used in dental implants and artificial hip joints to take advantage
of its higher mechanical strength compared to cp Ti. However, the toxicity of vanadium and
aluminum in the titanium alloy has been reported by several investigators since 1965. This study
was carried out to compare the mechanical properties and the biocompatibility of Ti-Fe alloy (TiX®)
to those of conventional metallic implant materials. The mechanical properties of TiX® were
measured and compared with cp Ti, Ti-Al-V, SUS316, SUS304, Co-Cr-Mo, and Ag-Sn. The
tensile strength of TiX® and Ti-Al-V were greater than those of Co-Cr-Mo, SUS316, and SUS304.
The yield point of TiX® was slightly lower than that of Ti-Al-V, but higher than that of cp Ti.
These results suggested the mechanical properties of TiX® were superior to those of Co-Cr-Mo,
SUS316, and SUS304. To evaluate the biocompatibility, cell culture technique with L929 cells
was used to investigate the cell multiplication, and SEM to investigate the morphological change of
adhered cells onto TiX®. The cell growth rate of TiX® was slightly higher than those of Ti-Al-V
and SUS316. Severe cytotoxicity was observed in Ag-Sn, and mild cytotoxicity in Ti-Al-V,
SUS316, SUS304 using gyratory culture method. These results revealed that TiX® is a useful
metallic material for wire, plate, porous, and mesh in dental and medical use, because of the
favorable biocompatibility and easy fabrication.
Polymer Scaffolds for Tissue Engineering
Authors: Chen Guo Ping , Tanaka M. , Tateishi Tetsuya
Published: March 2009

Three-dimensional biodegradable porous scaffolds play an important role in tissue
engineering as temporary templates for transplanted cells to guide the formation of the new organs.
Two kinds of novel biodegradable porous scaffolds for tissue engineering have been developed by
our group by hybridizing synthetic poly(α-hydroxy acids) with naturally derived collagen. One is
their hybrid sponge prepared by introducing collagen microsponges in the pores of poly(α-hydroxy
acids) sponge. The other one is their hybrid mesh prepared by forming collagen microsponges in the
interstices of poly(α-hydroxy acids) mesh. The hybrid scaffolds were used for three-dimensional
culture of fibroblast, tenocytes, chondrocytes and mesenchymal stem cells for tissue engineering of
skin, ligament, cartilage and osteochondral tissue. These cells adhered and spread well in the hybrid
scaffolds, proliferated, secreted extracellular matrices and formed the respective tissues. The
synthetic polymer sponge, or mesh serving as a skeleton, reinforced the hybrid scaffolds and
resulted in easy handling, while the collagen microsponges provided the hybrid sacffolds with a
microporous structure and hydrophilicity, and therefore, easy cell seeding. The hybrid scaffolds will
be useful for tissue engineering.
Process and Fabrication of Calcium Triphosphate and Hydroxylapatite Microspheres for Clinical Application
Authors: Brandau Egbert , Brandau Thorsten
Published: March 2009

Clinical applications of Calcium phosphate compounds are done in most cases with powders of
Calcium-tri-phosphate and/or Hydroxylapatite to enhance the surgery of orthopaedic repair.
The application of microspheres of these compounds has big advantages to faster surgery and higher
strength of the bone structure.
The special processes to produce microspheres of narrow size distribution and high sphericity out
Calcium-tri-phosphate and Hydroxylapatite are described.
Properties and composition of these microspheres as calcined and as sintered are given.
Preparation of Highly Porous Hydroxyapatite Ceramics from Cuttlefish Bone
Authors: Ivankovic H. , Gallego Ferrer G. , Tkalcec E. , Ivankovic M.
Published: March 2009

Scaffold of hydroxyapatite for further tissue-engineering application was produced by
hydrothermal treatment of cuttlefish bone originated aragonite at 200°C. Aragonite (CaCO3)
monoliths were completely transformed into hydroxyapatite after 48 hours of HT treatment. The
substitution of CO3- groups predominantly into the PO4
3- sites of the Ca10(PO4)6(OH)2 structure was
suggested by FTIR spectroscopy. SEM micrographs have shown that the interconnected hollow
structure with pillars connecting parallel lamellae in cuttlefish bone is maintained after conversion.
Specific surface area (SBET) and total pore volume increased and mean pore size decreased by HT
treatment.
Fabrication and In-Vitro Characterization of Three-Dimensional Composite Scaffolds by Robocasting for Biomedical Applications
Authors: Russias J. , Saiz Eduardo , Deville Sylvain , Tomsia Antoni P.
Published: March 2009

The development of novel biodegradable scaffolds for the treatment of bone and
cartilage defects is the subject of intense research. A successful scaffold will guide cell-attachment,
proliferation and tissue regeneration. The objective of this study is to use freeform fabrication
(robocasting) for the preparation of porous hybrid organic/inorganic materials with a well
controlled architecture and porosity. Polymer/hydroxyapatite (HA) pastes with ceramic contents
ranging between 0 to 70 wt. % are prepared by mixing ceramic powders with a solution of the
polymer in methylene chloride. Two different polymers are studied: polylactide (PLA) and
polycaprolactone (PCL). During the compression tests, the scaffolds show an elasto-plastic
behavior with large plastic yielding and do not fail in a brittle manner. The mechanical response is
anisotropic and depends significantly on the ceramic content and the type of polymer.
Development of Bioabsorbable DURA MATER
Authors: Takakuda Kazuo , Koyama Yoshihisa , Tominaga Ben , Ohno Kikuo , Mukai Tomokazu , Shirahama Noriaki
Published: March 2009

Regeneration of dura mater of the brain is one of the most urgent tasks in the fields of
regeneration medicine, considering the facts that we have many patients infected with fatal
Creutzfeldt-Jakob disease following transplant of dried dura mater in the brain operations. Hence we
designed the artificial dura mater made from poly(L-lactic acid-co-glycolic acid-co-ε-caprolactone).
The sutured substitutes have the ability to prevent the leakage of cerebral fluid, would be absorbed in
several months and the patient might be free from the possible side effects caused by the implanted
materials. The leakage-proof tests for the developed substitutes were carried out and it was
demonstrated that the sutured substitutes and dura mater support the pressure of saline as large as
400mmAq without leakage. The dural regeneration experiments were carried out with rabbits and
successful regenerations of dura mater were observed. No inflammations were observed around the
substitutes throughout the experimental period till the complete absorption of the materials.
Guided Bone Regeneration, Platelet Rich Plasma and Low-Intensity Ultrasound Irradiation for Dental Implants
Authors: Nagahara Kuniteru , Tanabe Toshiichiro , Ito Noriaki , Nagayama Motohiko , Takagi Kota , Fujii Shuho
Published: March 2009

Because a concept of an osteointegrated dental implant system was
established, prognosis of a dental implant at treatment improved and the treatment of
restoration for missing teeth was changed. However, a dental implant treatment into
atrophic jaw bone requires bone augmentation, obviously.
At this time, we studied for the purpose of establishing the evidence of each method for
clinical application of these bone augmentation method, such as guided bone
regeneration (GBR), and autogenous bone block graft (BBG). In addition, we pursued
the basic study of the evidence about the bone formation with platelet rich plasma
(PRP) which recognized the availability in clinic. Furthermore, we present the results of
basic studies which we tested for the purpose of applying a low-intensity pulse
ultrasound (LIPU) irradiation applied to a fracture treatment in orthopedics area to
intra-oral area, specially the condition after implant placement.
In the results of comparison with GBR site and BBG, the differences of labeling bands
were observed with a fluorescence microscopy. There was much labeling bands on GBR
sections in comparison with BBG. This meaning that the bone remodeling around
implants at GBR site was more active than BBG site.
And the new bone formation by PRP was identified on soft X-ray graphically at first
week after PRP applied mandible bone defect (experimental side). At same region of
first week specimen, we confirmed positive reactions of platelet derived growth factor
Guided Bone Engineering: Healing of Large Bone Defects
Authors: Schrooten Jan , Van Cleynenbreugel Tim , Impens Saartje , Luyten Jan , Bakker Astrid , Vander Sloten Jos , Luyten Frank P.
Published: March 2009

Tissue engineering (TE) aims/seeks to achieve the substitution of organ transplantation
by the creation of living, functional tissues. It has been suggested that biocompatible porous
materials (scaffolds) and a controllable 3D environment are required to aid in the 3D cell
organisation and their development into functional tissue. Our research envisions a TE-approach
towards the repair of large, load bearing defects in long bones. In vitro standardised, systematic,
quantitative screening of potential bone scaffolds is required to understand how scaffolds can affect
cell behaviour. This screening will avoid a trial-and-error approach and thus limit the number of
animal experiments. Such a screening should be based on the knowledge of mechanical, physical
and (bio)chemical scaffold properties and their interaction with cell behaviour. In addition, the
design and production of a clinically relevant scaffold requires control over its mechanical
behaviour and a new approach for cell seeding in a 3D scaffold, as well as providing nutrition for
the engrafted cells. The objective of this research is to gain substantial knowledge about guided
bone regeneration and to develop quantitative methodologies that can lead to consistent and
reproducible bone regeneration.
Mechano-Active Cartilage Tissue Engineering
Authors: Kim Soo Hyun , Jung Young Mee , Kim Sang Heon , Kim Young Ha , Xie Jun , Matsuda Takehisa , Min Byoung Goo
Published: March 2009

To engineer cartilaginous constructs with a mechano-active scaffold and dynamic
compression was performed for effective cartilage tissue engineering. Mechano-active scaffolds were
fabricated from very elastic poly(L-lactide-co-ε-carprolactone)(5:5). The scaffolds with 85 %
porosity and 300~500 μm pore size were prepared by a gel-pressing method. The scaffolds were
seeded with chondrocytes and the continuous compressive deformation of 5% strain was applied to
cell-polymer constructs with 0.1Hz to evaluate for the effect of dynamic compression for
regeneration of cartilage. Also, the chondrocytes-seeded constructs stimulated by the continuous
compressive deformation of 5% strain with 0.1Hz for 10 days and 24 days respectively were
implanted in nude mice subcutaneously to investigate their biocompatibility and cartilage formation.
From biochemical analyses, chondrogenic differentiation was sustained and enhanced significantly
and chondrial extracellular matrix was increased through mechanical stimulation. Histological
analysis showed that implants stimulated mechanically formed mature and well-developed
cartilaginous tissue, as evidenced by chondrocytes within lacunae. Masson’s trichrome and Safranin
O staining indicated an abundant accumulation of collagens and GAGs. Also, ECM in constructs was
strongly immuno-stained with anti-rabbit collagen type II antibody. Consequently, the periodic
application of dynamic compression can improve the quality of cartilaginous tissue formed in vitro
and in vivo.
Patient Specific Finite Element Modeling of a Human Skull
Authors: Inou Norio , Koseki Michihiko , Maki Koutarou
Published: March 2009

This paper presents automated finite element modeling method and application to a
biomechanical study. The modeling method produces a finite element model based on the
multi-sliced image data adaptively controlling the element size according to complexity of local
bony shape. The method realizes a compact and precise finite element model with a desired total
number of nodal points. This paper challenges to apply this method to a human skull because of its
intricate structure. To accomplish the application of the human skull, we analyze characteristics of
bony shape for a mandible and a skull. Using the analytical results, we demonstrate that the
proposed modeling method successfully generates a precise finite element model of the skull with
fine structures.
Composite Layer with a Ti3P External Zone Produced on Titanium Alloy for Bone Applications
Authors: Czarnowska E. , Zajaczkowska A. , Sowinska A. , Godlewski M.M. , Mizera Jaroslaw , Wierzchon T.
Published: March 2009

A diffusion surface layer of Ti3P+Ti-Ni type was produced on Ti6Al4V titanium alloy by a
chemical electroless nickel-phosphorous deposition process combined with glow discharge treatment. The
microstructure, phase composition, surface topography, corrosion and wear resistance of this surface layer
were investigated, as was its biocompatibility with the human Saos-2 cell line. Cells were analysed in terms
of cell viability and adhesion. The results showed that the duplex treatment permits production of a layer that
has high corrosion and frictional wear resistance and the Ti3P outer zone of this composite layer is
characterised by a topography and chemical composition promising high biocompatibility. This new
Ti3P+Ti-Ni type layer offers new potential in biomaterials for bone applications in terms of improved tissue
ingrowth and long-term use.
Synthesis and Nanocomposite Sintering of Hydroxyapatite-Coated Zirconia Nanopowders
Authors: Bondioli Federica , Cannillo Valeria , Lusvarghi Luca , Manfredini Tiziano , Ferrari Anna Maria
Published: March 2009

Hydroxyapatite (HAP), Ca10(PO4)6(OH)2, is a well-known and a valuable implant
material with biocompatibility and bioactive properties. Full utilisation of the unique properties of
hydroxyapatite bulk ceramics is, however, enhanced by a proper reinforcement, i.e. by preparation
of composites. The goal of this study was to synthesize a HAP-coated zirconia composite powder
by the precipitation of HAP in presence of zirconia. The idea was to avoid uncontrolled
agglomeration of the zirconia nanostructured reinforcement during the sintering step. ZrO2
nanopowders, previously synthesized by hydrothermal crystallisation, were added in an appropriate
amount to an intensively stirred aqueous suspension of Ca(OH)2. HAP was precipitated by addition
of H2PO4 at controlled pH in order to obtain a 50:50 composite powders. The obtained powders,
fully characterized by TEM, XRD, TG-DTA and BET, were used for the preparation of the
nanostructured composite speciments. The sintered materials were characterized in order to
evaluate their structural and morphological properties.
Nanostructured Carbon Films Produced by Pulsed Laser Deposition for Bio-Medical Applications
Authors: Mangione A. , Torrisi Lorenzo , Picciotto A. , Visco Anna Maria , Campo Nino
Published: March 2009

Damond-like (DLC) films can be produced by Pulsed Laser Deposition (PLD) technique. Different
pulsed lasers can be employed to generate hot carbon plasma, to deposit and/or to implant
energetic carbon atoms and molecules on substrates. A Nd:Yag laser radiation with ns pulse
duration, about 1010 W/cm2intensity and 30 Hz repetition rate, can be employed to produce in
vacuum thin carbon films with properties similar to graphite and diamond. The films were
deposited on SiO2 substrates, placed at different distances and angles from the target. The PLDgenerated
plasma can be controlled “in situ” by mass quadrupole spectroscopy and time-of-flight
tehniques. “Ex situ” investigations were performed on the deposited films by using the Scanning
Electron Microscopy (SEM) and Raman spectroscopy. Deposited films show evidence of carbon
nanostructures, which find a growing variety of applications in medicine and bio-enegineering
fields. Diamond-like carbon (DLC) shows low friction, high atomic density, hard but flexible
structure, chemical inertia, wear, diffusion and corrosion resistance and highly bio and hemocompatible
properties.
Effect of Cation Dopant on Phase Stability of Zirconia Bioceramics in Hot Water
Authors: Takigawa Yorinobu , Naka Yukihisa , Higashi Kenji
Published: March 2009

The effect of cation ion dopant on phase transformation of zirconia bioceramics is evaluated by
ageing in hot water. The phase transformation progresses with time in all specimens. However, the
transformation behavior is much different depending on the dopant. The transformation is promoted
when the 1 mol% of pentavalent element is added to 3mol% yttria stabilized zirconia (3Y-TZP). In
contrast, the transformation is suppressed when the bivalent element is added. In case that the
tetravalent element is added, the transformation is promoted if the ionic radius of the element is
larger than that of zirconium, and the transformation is suppressed if the element with smaller ionic
radius than zirconium ion is added. This result indicates that the ionic radius and the valency of ions
are important factors to control the phase stability in zirconia.
Laser CVD of Filaments
Authors: Frischknecht K.D. , Diefendorf R.J.
Published: March 2009

Lasers have been used to chemically vapor deposit materials since the 1970’s. The fine
focus achievable with the laser beam allows deposition to be carried out on a substrate much like
hand-writing. The formation of a filament simply requires moving the filament to keep the laser
beam focused on or near the depositing tip of the filament. Deposition rates can be very rapid
because of the high mass transport rate that can be achieved, although the total mass deposited is
low. Multiple beams can be used to increase the number of filaments being formed, but the high
deposition rate would be sacrificed somewhat. However, the process is attractive for producing
small amounts of new high temperature materials in the easily tested filament form. The process is
also amenable to easily making more complicated shapes such as coils that could be used for
heating or other applications. Deposition kinetics are different for cases where deposition is from
the original deposition molecule or early formed fragment, compared to intermediates formed by
subsequent gas phase reactions.
CMC and C/C-SiC-Fabrication
Authors: Weiss Roland
Published: March 2009

Ceramic Matrix Composites (CMC) have a wide interest for high temperature
applications. The materials can be modified by the selection of the matrix precursor as well as of the
reinforcing materials. C/C-composites can be easily modified by post-treatments with silicon in
order to acquire different tribological properties from good sliding behaviour up to braking systems
only depending on the manufacturing technique of these materials. It will be demonstrated during
the presentation that the manufacturing depends on one hand side on the material which has to be
manufactured and on the other side on the structural component and the number of parts which are
required. Furthermore, it will also be shown, that silicon treatments can be performed up to a full
conversion of C/C materials creating a new family of monolithic ceramic materials. Within the
presentation detailed information will be given on possible processing routes as well as the resulting
physical and mechanical properties of the materials.
Mechanical Behaviour Al-Matrix Composite Wires in Double Composite Structures
Authors: Kientzl Imre , Orbulov Imre Norbert , Dobránszky János , Németh Árpád
Published: March 2009

The fibre reinforced metal matrix composites (FRMMC-s) are one of the main groups of
the composite materials. The composite wires are continuous-fibre-reinforced aluminium matrix
composites, which are made by a continuous process. Composite wires already have a few
experimental applications for the reinforcement of high voltage electric cables. Other experimental
application fields of these materials are the preferential reinforcement of the cast parts. In this way
significant decrease in the weight could be achieved. The aim of this study is to show the excellent
mechanical properties of the composite wires, and the contact relationship between the mechanical
and other properties (i.e. thermoelectric power) and the possibility of their standardized production.
The continuous production process of the composite wires and their test results were are shown as
well. The difference between the composite wire reinforced double composite structures and direct
fibre reinforced blocks were delineated as well. In this paper specimens were examined by tensile
tests, bending tests, thermal aging tests and thermoelectric power measurement.
Vibration Damping Properties of Nanotube-Reinforced Materials
Authors: Kireitseu Maksim
Published: March 2009

Energy dissipation (damping) in structures/materials at the nanoscale level, the damping/
dynamics of materials require investigations before they will come to advanced engineering applications.
By invoking the properties of nanostructures, it may be possible to enhance the energy
dissipation. The paper therefore presents some preliminary results on the topic providing route map
to the nanotechnology-based vibration damping solutions and comparison of some experimental
damping behavior of nanoparticle-reinforced polymeric structures.
Improved Oxide-Based Interfacial Coatings for the Next Generation of CMC's
Authors: Baklanova Natalia I. , Zaitsev B.N. , Titov Anatoly
Published: March 2009

CMC's reinforced by SiC-based fibers achieve high toughness and damage tolerance
through the disposal of weak fiber coating which can deflect cracks and promote debonding at the
fiber/matrix region. Refractory oxide-based systems are considered as the most promising ones for
this purpose. Sols of zirconia, including stabilized zirconia were used as simple and readily
processable precursors for obtaining interfacial coatings on SiC tow and cloth. The morphology,
composition, topography, roughness, tensile properties of as-prepared and exposed to air at 1000°C
coated fibers were evaluated by SEM/EDS, XPS, XRD, AFM, micro Raman analysis. The
peculiarities of the behavior of oxide-coated fibers are governed by the properties of initial sols,
procedure for coating fabrication, chemical and nanostructural factors. The peculiarities of the
behavior of the stabilized zirconia interphase with accurate phase control will be discussed. A
monitoring of the t→ m phase transformation within ZrO2 interfacial coating on SiC fiber using
micro Raman makes it possible quantitatively to evaluate an ability of ZrO2 as oxidation resistance
and readily deformable weak interfacial coating for the next-generation CMC's.
Molecular Dynamics Simulation of Organic Molecules Distorted Conformation in Zeolites
Authors: Semprini E. , Perez G. , Stefani Ferdinanda , Cafarelli Patrizia , De Stefanis A. , Tomlinson A.A.G.
Published: March 2009

Experimental results indicate that conformational changes of organic molecules occurring in the
gaseous and in the liquid phase are hindered or lowered in constrained environments like zeolite
pores. A successful understanding of the processes occurring in this type of materials requires a
good description of the equilibrium properties, which can be calculated by the Grand Canonical
Monte Carlo method. In particular, in the present work conformational changes, such as boat →
chair for cyclohexane, are studied by molecular dynamics simulation, as a function of pore size and
temperature.
Evolution of Pt Nanoclusters Morphology on PEMFC Electrode due to Methanol Oxidation Reaction Studied by Electron Microscopy and Synchrotron Grazing Incidence X-Ray Diffraction
Authors: Alvisi Marco , Galtieri Giovanna , Giorgi L. , Serra Emanuele , Di Luccio Tiziana , Giorgi R.
Published: March 2009

The proton exchange membrane fuel cells (PEMFC) have been developed mainly as a
power source for vehicles, power generation and consumer electronics since they combine high
energy conversion efficiency at relatively low temperatures without pollutants emission in the
environment. An electrode for a PEMFC is a layered structure composed by a catalyst layer
deposited on a porous carbon substrate. The substrate is usually covered by a diffusion layer that
enhances the gas and water flow. Platinum nanoparticles supported by carbon microparticles are
commonly employed as catalyst layer. In this work an extreme ultra-low loading of Pt catalyst (<
0.02 mg/cm2) has been deposited by magnetron sputtering on gas diffusion electrodes, with different
carbon supports (Vulcan and SuperP), in order to enhance the activity of PEM fuel cells. The
morphology (shape and grain size) and microstructure have been studied combining field emission
scanning electron microscopy (FEG-SEM), grazing incidence synchrotron x-ray diffraction
(GIXRD) and x-ray photoelectron spectroscopy (XPS). The results presented here concern the
evolution of the cluster size and shape after the ageing, induced by cyclic voltammetry for methanol
oxidation reaction.
Quantum Dots in GaInP/GaInAs/GaAs for Infrared Sensing
Authors: Lim H. , Tsao S. , Taguchi M. , Zhang W. , Quivy A.A. , Razeghi M.
Published: March 2009

Nanotechnology is occurring simultaneously in almost every field with strong
interdisciplinary applications which have unique and important characteristics for potential novel
and high performance devices. Quantum dots grown by epitaxial self-assembly via Stranski-
Krastanov growth mode have many favorable properties for infrared sensing. Because of their very
small size and three-dimensional confinement, the electronic energy levels are quantized and
discrete. These quantum effects lead to a unique property, “phonon bottleneck”, which might enable
the high operating temperature of infrared sensing which usually requires cryogenic cooling. Here
we report a focal plane array (FPA) based on an epitaxial self-assembled quantum dot infrared
detector (QDIP). The device structure containing self-assembled In0.68Ga0.32As quantum dots with a
density around 3×1010 cm-2 was grown by low-pressure metalorganic chemical vapor deposition
(LP-MOCVD). Using different structures, we successfully developed QDIPs with a peak
photoresponse around 5 μm and 9 μm. High peak detectivities were achieved at 77 K from both
QDIPs. By stacking both device structures, we demonstrated a two-color QDIP whose peak
detection wavelength could be tuned from 5 μm to 9 μm by changing the bias. 256×256 detector
arrays based on 5 μm and 9 μm-QDIPs were fabricated with standard photolithography, dry etching
and hybridization to a read-out integrated circuit (ROIC). We demonstrated thermal imaging from
our FPAs based on QDIPs.
Investigation on the Reinforcement of Multi-Walled Carbon Nanotubes on Alumina Matrix
Authors: Sun Jing , Gao Lian
Published: March 2009

In this paper, a colloidal processing route was adopted to disperse multi-walled
carbon nanotubes (MWNTs) into alumina powders homogenously. Alumina matrix composites
containing 0.1 to 2 weight percent of MWNTs were successfully fabricated by pressureless sintering.
Also, 1wt% MWNTs-alumina composites were prepared by hot pressing for comparison. It was
found that when the sample was sintered at 1450oC, the addition of 1wt% carbon nanotubes led to
10% increase in bending strength compared with monolithic alumina. The reinforcement
mechanism was discussed based on the microstructure investigation. The broken nanotubes and
pullout of MWNTs at interfaces are efficient in transferring the load from the alumina matrix to the
nanotubes, leading to the improvement of the mechanical properties.
Characterization of Fullerene / TriA-PI Composites
Authors: Shinoda Yasuaki , Shiota Ichiro , Ishida Yuichi , Ogasawara Toshio , Yokota Rikio
Published: March 2009

TriA-PI is a newly developed phenylethnyl terminated polyimide. It exhibits
excellent mechanical properties and processability with high glass transition temperature
(Tg>300°C). Nano-size particles of fullerene were dispersed throughout a thermosetting
polyimide Triple API (TriA-PI) to elevate the glass transition temperature. The increase of the
glass transition temperature of the composites with the fullerene was confirmed by dynamic
mechanical analysis (DMA).
Carbon-Based and Other Nanostructures Obtained via Cluster-Assembling: A View Combining Electron Spectroscopies and Nanospectroscopies
Authors: Gavioli L. , Sancrotti M.
Published: March 2009

This work will provide an overview of recent experiments devoted to study the nature
and properties of materials obtained in situ via cluster-assembling, by using supersonic cluster beam
deposition. This technique has proved to be a powerful tool for assembling nanostructured materials
with tailored physical properties, in particular for: 1) carbon-based clusters deposited in situ on
appropriate substrates in Ultra High Vacuum compatible conditions; 2) a micro-structured pattern
based on pristine carbon-based dots and then promoted to the formation of SiC via in situ thermal
annealing; 3) thermo-chemically doped nanostructured TiO2, revealing the possibility to control the
band gap of this material. The electronic structure of the systems has been studied combining a
wide variety of experimental methods, including valence-band and core-level photoemission,
Electron Energy Loss Spectroscopy, Scanning Auger Spectroscopy, Atomic Force Microscopy.
Transport Properties of (Ga,Mn)As Diluted Magnetic Semiconductors in the Bulk and in Layered Systems
Authors: Turek Ilja , Carva K. , Kudrnovsky J.
Published: March 2009

Transport properties of systems based on diluted magnetic semiconductors (Ga,Mn)As
are investigated theoretically by means of the Kubo linear response theory. The underlying
electronic structure is obtained within the local spin-density approximation using the scalarrelativistic
tight-binding linear muffin-tin orbital (TB-LMTO) method. The effect of substitutional
randomness on the electronic structure and on the transport properties is systematically described in
the coherent potential approximation (CPA). The quantities studied include the residual resistivities
of the bulk alloys as well as conductances of epitaxial trilayers Cr/(Ga,Mn)As/Cr (001) in the
current-perpendicular-to-plane (CPP) orientation. The results witness that various compensating
defects such as As antisite atoms and Mn interstitials have much stronger detrimental effect on the
spin polarization of the CPP conductances as compared to their influence on the spin polarization of
the bulk conductivities.
Disorder Effects on Tunneling Junctions
Authors: Da Costa Victor , Romeo M.
Published: March 2009

This paper illustrates statistical properties of tunnel currents flowing through metalinsulator-
metal tunnel junctions. A direct experiment performed on a metal-oxide junction shows
that the tunnel current follows broad statistical distributions extending over more than 4 orders of
magnitude. A simple lognormal law is proposed to explain the properties of currents flowing
through tunnel junctions.
A Magnetoelectric Effect in Low-Carrier Density Colossal Magnetoresistance Materials
Authors: Auslender M.
Published: March 2009

It is shown that in colossal magnetoresistance materials an inhomogeneous alternating
magnetic field generates a strong electric field of non-inductive nature. This magnetoelectric effect
is an analog of acoustoelectric effect in conventional semiconductors. Due to the above electric
field spin waves in the former materials, like acoustic waves in the latter ones, acquire an additional
attenuation at equilibrium. This attenuation may be converted to amplification by applying strong
enough dc electric field drifting the carriers (solid-state Cherenkov’s effect). The experiments,
which probed this phenomenon in HgCr2Se4 using spin wave pumping, are discussed.
Isolated and Grouped Co Spins in Polycrystalline Zn1-xCoxO Oxides
Authors: Zhang Yue Bin , Sritharan Thirumany , Li Sean
Published: March 2009

Polycrystalline stoichiometric Co-substituted ZnO oxides have been synthesized by solid
state reaction via sintering ZnO and Co powders in air. The precise nature of magnetic coupling is
determined by studying carefully structural and magnetic properties. The magnetization as a
function of temperature for Zn1-xCoxO (x = 0.02, 0.05, 0.0625 and 0.10) can be fitted well to a
model with a paramagnetic Curie term, an antiferromagnetic Curie-Weiss term and a diamagnetic
constant, which could arise from spins of isolated Co ions, grouped Co ions that are in nearest
neighbor positions and a diamagnetic background, respectively. The substitution of Co at the Zn
sites does not occur in a completely random manner but the Co ions appear to have a tendency for
grouping. It is interesting to note in Raman measurements that host lattice defects with 2 distinct
impurity modes may be induced by isolated and grouped Co spins.
Transient Wigner Function Studies of DMS Barrier Devices
Authors: Grubin H.L.
Published: March 2009

Incorporating diluted magnetic semiconductor (DMS) layers within barrier
devices offers new device design potential. To study these devices we have
generalized an existing time dependent transient algorithm that couples the Wigner
transport equation to Poisson’s equation and an external circuit. For electron transport
we have studied alterations in the dc and time dependent behavior of resonant
tunneling diodes with DMS barriers and wells, have transformed a single barrier
structure into a double barrier structure and examined the increased functionality of
the devices. We present new results, including some preliminary calculations incorporating
holes, discuss transients and the potential role that DMS layers will
play in controlling the transient operation of superlattice structures.
Fabrication and Investigation of Hybrid Device Consisting of Ferromagnetic Nanodots and Ga(Mn)As
Authors: Chang Joon Yeon , Kim W.Y. , Chun S.H. , Saphonin M. , Mironov V.L. , Gribkov B.A. , Fraerman A.A.
Published: March 2009

The new hybrid device consisting of patterned array of Co nanodots on GaMnAs channel was
fabricated and demonstrated to give a new functionality to control the transport properties of
GaMnAs. Magnetic state of array of Co nanodots was observed with magnetic force microscopy
(MFM) observation. The magnetic state of individual Co dots can be controlled by using a MFM tip.
Different distribution of magnetic state of Co nanodots in an array structure resulted in an
inhomogeneous magnetic field. Magnetic field induced by the array of nanodots leads to change in
the transport properties of GaMnAs. This inhomogeneous magnetic field was regarded to act as an
effective potential that can trap the spin polarized carriers in the GaMnAs system with giant Zeeman
splitting.
Nano Patterned Surfaces for Biomaterial Applications
Authors: Gadegaard Nikolaj , Dalby Matthew J. , Martines Elena , Seunarine Kris , Riehle Mathis O. , Curtis Adam S.G. , Wilkinson Chris D.W.
Published: March 2009

Bionanotechnology has seen much interest in the past few years. The development in
new nanotechnologies and the transfer of such to biomedical applications has been received with
large expectations. Here we will describe some of the most common techniques to prepare surfaces
with nanometric sized features and how they have been applied to control cell behavior. The focus,
however, will be on electron beam lithography and its use in biological applications. We will show
that such highly ordered surfaces exhibit low adhesive properties for cells. Also, such topographies
change the wetting properties to be either more hydrophilic or hydrophobic depending on the
surface energy of the flat surface. Today, little research has found its way to the commercial market.
This is mainly down to the ability to make large areas or large quantities of nano patterned
materials. We will describe a few methods by which we think it would be possible to mass produce
nano topographically patterned surfaces.
Modulation of Biological Properties of Silicon Nitride for Biosensor Applications by Self-Assembled Monolayers
Authors: Gustavsson J. , Altankov G. , Errachid A. , Samitier Josep , Planell Josep A. , Engel Elisabeth
Published: March 2009

As a ceramic, silicon nitride (Si3N4) has been suggested as a biocompatible material in
contact with bone. In another configuration, as a low pressure chemically vapor deposited
(LPCVD) thin film, Si3N4 can also be used as the sensitive material in certain biosensor
applications. With the latter in mind, the biocompatibility of such films was investigated after them
being modified with silane based self-assembled monolayers (SAMs) bearing functional end groups
of methyl (CH3), primary amine (NH2), and carboxyl (COOH) respectively. The SAM surface
modifications provided a wide range of physiochemical properties including hydrophobic (CH3),
hydrophilic (bare Si3N4), positively (NH2) and negatively charged (COOH). Specifically the cell
adhesion and proliferation, as well as the levels of alkaline phosphatase activity and osteocalcin,
have been evaluated using the human osteoblast-like MG-63 cell line. It was observed that
attachment and spreading was pronounced on NH2 while suppressed on CH3. With time the cells
grew to confluence on all chemistries, and the levels of osteocalcin normalized to total protein
content varied as CH3 > Si3N4 > COOH > NH2, but without significant differences. The highest
spontaneous alkaline phosphatase activity was observed from cells grown on Si3N4 substrata.
Self-Organized Metal Oxide Exhibiting Enhanced Bioactivity
Authors: Karlinsey Robert L. , Hara Anderson T. , Duhn Clif W.
Published: March 2009

Self-assembled niobium oxide microcones produced by potentiostatic anodization with varied
NaF content (between 100 and 250 mg) in an HF electrolyte are shown to nucleate mineral when
immersed in supersaturated solutions emulating mineral content in saliva and blood. The most
extensive mineral coverage in 100 mL of 2.5 wt. % HF electrolyte occurs when NaF content is
about 100 mg with substantial mineral formation occurring within 24 hours. Higher salt content
apparently alters the conditions favoring mineral nucleation by generating smaller nucleation
centers that ultimately diminish the extent of mineral coverage. Additionally, nucleation kinetics
and morphological contrasts between mineral formed from saliva and blood is briefly discussed in
terms of the relative degree of supersaturation with respect to hydroxyapatite. Finally, we show that
the integrity of the microcone shape is not critical for mineral nucleation, an observation that builds
on our prior hypothesis by promoting the importance of self-assembly and crystal formation. Based
on these results, we demonstrate the influence of NaF and stress the role of the self-organization
process in producing effective mineral nucleation sites.
Release of Proteins from Nanochannel Delivery Systems: A Coupled Many-Scale Simulation - Experimental Investigation
Authors: Pricl Sabrina , Ferrone Marco , Cosoli Paolo , Paneni Maria Silvia , Fermeglia Maurizio , Cosentino Carlo , Amato Francesco , Cheng Mark M.C. , Ferrari Mauro
Published: March 2009

Transport and surface interactions of proteins in nanopore membranes play a key role in
many processes of biomedical importance. Although the use of porous materials provides a large
surface-to-volume ratio, the efficiency of the operations is often determined by transport behavior,
and this is complicated by the fact that transport paths (i.e., the pores) are frequently of molecular
dimensions. Under these conditions, wall effects become significant, with the mobility of molecules
being affected by hydrodynamic interactions between protein molecules and the wall. Modeling of
transport in pores is normally carried out at the continuum level, making use of such parameters as
hindrance coefficients; these in turn are typically estimated using continuum methods applied at the
level of individual diffusing particles. In this work we coupled experimental evidences to manyscale
molecular simulations for the analysis of hen egg-white lysozyme adsorption/diffusion
through a microfabricated silicon membrane, having pores of nanometric size in only one
dimension. Our joint efforts allowed us a) to elucidate the specific mechanisms of interaction
between the biopolymer and the silicon surface, and b) to derive molecular energetic and structural
parameters to be employed in the formulation of a mathematical model of diffusion, thus filling the
gap between the nano- and the macroscale.
PVA-HAp Nanocomposites for Artificial Cornea
Authors: Kobayashi Hisatoshi
Published: March 2009

To solve the shortage of the donor cornea in Japan, we are developing a poly(vinyl alcohol)
hydrogel based keratoprosthesis. Minimum requirements for a keratoprosthesis include light transparency,
non-toxicity, and nutrition and fluid permeability. Earlier clinical trials had frequently failed because corneal
epithelial down growth occurred between the host cornea and the materials, and the materials were finally
rejected from the host cornea. The major cause of this rejection is the weak adhesion between the host cornea
and the prosthesis. In order to achieve the firm fixation of the artificial cornea to host cornea, composites of
collagen-immobilized poly(vinyl alcohol) hydrogel with hydroxyapatite(PVA-HAp nano composites) were
synthesized. The preparation method, characterization, and the results of corneal cell adhesion and
proliferation on the composite materials were studied. The PVA-HAp nano composites were successfully
synthesized. Chick embryonic keratocyto-like cells were well attached and proliferated on the PVA-HAp
composites. This material showed potential for keratoprosthesis.
'Top Down' Approaches for the Study of Single-Cells: Micro-Engineering and Electrical Phenotype
Authors: Senez Vincent , Akalin T. , Arscott S. , Bourzgui N.E. , Bocquet B. , Fujii T. , Lennon E. , Yamamoto Takahisa
Published: March 2009

Single-cell analysis is a very important field of research and is currently at the frontier of
physical and biological sciences. Understanding how the phenotype of a single-cell arises from its
genotype is a complex topic. Currently, the prevailing paradigm to analyze cellular functions is the
study of biochemical interactions using fluorescence based imaging systems. However, the
elimination of the labelling process is highly desirable to improve the accuracy of the analysis.
Living cells are electromagnetic units; in as much they use electric mechanisms to control and
regulate dynamic processes involved in inter alia signal transduction, metabolism, proliferation and
differentiation. Recent developments in micro- and nanofabrication technologies are offering great
opportunities for the analysis of single cells; the combination of micro fluidic environments, nano
electrodes/wires and ultra wide band electromagnetic engineering will soon make possible the
investigation of local (submicrometer scale) dynamic processes integrating several events at
different time scales. In the paper, we present recent approaches which aim at investigating singlecells
with the help of MEMS and NEMS (Micro and Nano Electro Mechanical Systems) and ultra
wide band (DC-THz) electromagnetic characterization techniques.
Rapid Shrinking of Porous Hydrogel Prepared by Ice Templating
Authors: Umebayashi Eri , Murai Wakaaki , Suguro Kazuho , Morohoshi Tomohiro , Ikeda Tsukasa , Kato Norihiro
Published: March 2009

To control and maximize the shrinking rates of thermo-sensitive organic-inorganic (O-I)
hybrid gels, microporous structure of gels could be controlled by ice-templating. Water-swollen gels
easily became porous after freezing. Applying the freezing method effectively accelerate the
shrinking rates of the poly(N-isopropylacrylamide), polyNIPA-based O-I hybrid gels by two different
ways. One is the interpenetrating network with polyNIPA and polysiloxane. The other is the
copolymer network of NIPA and a vinyl monomer possessing the trimethoxysilane, of which
crosslinking was carried out by sol-gel reaction. Their thermally-triggered shrinking kinetics was
investigated by measuring the weight change of gels. Shrinking coefficients (D) were determined by
fitting the shrinking data with the Fick’s model. The coefficients after applying the freezing method
increased to approximately 10-3 cm2s-1 while those before freezing were on the order of 10-5 - 10-6
cm2s-1.
Synthesis and Characterization of Thermal Actuators Based on Composite Coatings with Phase Change Materials
Authors: Malfliet Annelies , Stappers Linda , Fransaer Jan
Published: March 2009

Metal coatings with embedded phase change material (PCM) particles were made by
electrolytic deposition. These composite coatings have useful thermo-mechanical properties for
thermal actuators. The PCM particles which are homogeneously dispersed in the metal matrix
provide a large thermal expansion of the composite at the phase change temperature. Since the
metal matrix has a good thermal conductivity, it allows fast heating of the embedded PCM particles
and hence fast actuation. In this study, paraffin and water were used as PCM in copper, zinc and
nickel coatings. To embed PCM material in electrolytic metal coatings, the PCM has to be
encapsulated first. This was done by emulsion polymerization for paraffin and by solvent
evaporation of a double emulsion for water. PCM-metal composite coatings are made by adding the
PCM particles to the electrolyte used for metal plating. The properties of the metal-PCM composite
coatings were examined by differential scanning calorimetry (DSC) and vertical dilatometry. The
thermal expansion of the paraffin composite coatings showed a sharp increase in a small
temperature range above the melting point of the paraffin and a total expansion of 1 % was found.
Although a sharp expansion increase in a small temperature range is ideal for thermal actuators, the
effect decreased by thermal cycling. A thermoelastoplastic model was developed to describe the
thermal expansion of the composites. For water containing composite coatings, very large
expansions of up to 15 % were obtained, but the temperature range over which this expansion
occurs is large.
A New Designing Concept for Multifunctional Structural Material Systems Based on Composites
Authors: Asanuma Hiroshi
Published: March 2009

A new designing concept to realize multifunctional structural material systems is proposed
and demonstrated in this paper. The concept can be explained as follow: There exist a couple of
competitive structural materials which normally compete with each other because of their similar and
high mechanical properties, and they tend to have secondary properties which are different from each
other or opposite among them. So if they are combined together to make a composite, the similar
properties, normally high mechanical property, can be maintained, and the other dissimilar properties
conflict with each other, which will generate functional properties. According to the proposed concept,
a CFRP (carbon fiber reinforced plastics)/aluminum laminate was fabricated and its actuation
capabilities and multifunctionality were successfully demonstrated. A titanium fiber/aluminum
matrix composite was also fabricated, where the fiber was oxidized for electrical insulation and
strengthening. This material system is very simple, but it can generate many useful functions such as
heating, actuation, temperature sensing, deformation sensing and healing.