bluuebunny/crossref_metadata_2025 huggingface dataset:
Origin of the multi-exponential decay dynamics in light-emitting silicon nanocrystals
Authors: Reynaud Cécile , Guillois Olivier , Herlin-Boime Nathalie , Ledoux Gilles , Huisken Friedrich
Published: April 2011

Light-emitting silicon nanocrystals (nc-Si) have attracted much interest due to their importance for optoelectronic devices. Electron hole recombination in a quantum confined system is generally considered as the theoretical frame explaining the photoluminescence (PL) origin. However, there is still a living debate, in particular regarding the PL decay dynamics. The decay is not single exponential and decay curves described by a stretched exponential law were systematically reported for all types of nanocrystalline silicon. The origin of this multi-exponential decay is often attributed to migration effects of the excitons between nanocrystals. In contrast to these approaches, the absence of carrier hopping has been demonstrated experimentally in porous silicon. In order to elucidate this question, specific samples were prepared, consisting in deposits made from gas phase grown silicon nanocrystals with different particle density. The nanoparticles were synthesized by laser pyrolysis of silane in a gas flow reactor, extracted as a supersonic beam, size-selected, and deposited downstream as films of variable densities by changing the deposition time. The nanoparticle number densities were determined by atomic force microscopy. Time-resolved photoluminescence measurements on these films were carried out as a function of the film density and at different PL wavelengths. The reported results showed photoluminescence properties independent of the film density. Even in the very low density film (∼4*109 particles/cm2) where nanoparticles are completely isolated from each other, the decay kinetics corresponds to a multi-exponential law. This means that exciton migration alone cannot explain the stretched exponential decay. Its origin must be linked to an intrinsic characteristic of the nc-Si particle. In this paper, the experimental results are described in more details and compared to the theoretical predictions available in the frame of the quantum confinement model. Then, the possible origins of the multi-exponential character of the decay dynamics is discussed, and the particular properties of the PL in indirect band-gap semiconductors emphasized.
Nanorings, Nanopillars and Nanospikes on Si(111) by Modified Nanosphere Lithography: Fabrication and Application
Authors: Rose Jefferson , Baugh Delroy
Published: April 2011

Uniform arrays of nanopillars, nanospikes, nanorings and rings atop nanopillars were fabricated using modified nanosphere lithography on the Si(111) surface and observed using AFM and SEM. A self-assembled monolayer mask which utilized 450±10nm polystyrene spheres were used as an etch mask during a fabrication process of physical Ar+ ion bombardment followed by SF6RIE to produce nanopillars with flat tops that could be as large as 210nm in height and 175nm in diameter. Nanospikes of approximately the same height were fabricated made with a FWHM of 250nm. The initial Ar+ion bombardment step was varied to achieve up to 4 times faster etch rates and narrowed widths in the nanospikes. Both types nanostructures systems were “self-wired” which is an intrinsic result of this fabrication process. Self-wired nanorings and rings atop nanopillar structures were also fabricated using a two step etching process along with sonication. The nanorings had inner and outer diameters of 225±5nm and 175±5 nm, respectively and were up to 20nm in height and their nanowire connectivity could be made optional by a judicious choice of solvent for sonication. The self-wired Si nanostructures were also “dressed” with self-assembled Ge quantum dots. These Ge/Si nano-architectured structures possess the basic framework for fabricating novel nanoelectronic and nano-optoelectronic devices in the foreseeable future.
Characterization of SiC nanowires grown by APCVD using single precursors
Authors: Rho Dae-Ho , Kim Jae-Soo , Byun Dong-Jin , Yang Jae-Woong , Lee Jae-Hoon , Kim Na-Ri
Published: April 2011

SiC nanowire was grown by APCVD using single precursors. Grown SiC nanowires had 10∼60nm diameters and lengths of several micrometers. Nanowire's diameters and lengths were varied with kind of catalysts. Nanowire's growth scheme was divided by two regions with diameter of nanowire. At first region, nanowire was grown by VLS (vapor-liquid-solid) mechanism, but at the second region, nanowire growth was made by VS (vapor-solid) reaction. These differences were made from limitations of growth rate and deactivation effects. Growth temperature, time and flow rates of source gases were affected nanowire's diametesr and its lengths. And kind of catalysts, coating methods and precursors were affected growth direction and microstructures too.
Hard PVD Coatings for Austenitic Stainless Steel Machining: New Developments
Authors: Endrino J. L. , Wachter A. , Kuhnt E. , Mettler T. , Neuhaus J. , Gey C.
Published: April 2011

The machinability of austenitic stainless steels is, in general, considered to be a difficult process. This is due in great part to the high plasticity and tendency to work-harden of the workpiece, which normally results in extreme conditions imposed on cutting edges. Additionally, austenitic stainless steels have much lower thermal conductivities in comparison to plain carbon and tool steels; this inflicts high thermal loads within the chip-tool contact zone, which can significantly increase the wear rate. The complex machining of austenitic stainless steels can be, in part, relieved by use of a hard coating with low thermal conductivity and an adequate coating surface quality. This can lead to a low friction coefficient between the parts and an improved chip evacuation process. In this study, stainless steel plates were machined using a high speed finishing process and cemented carbide tools coated with four high aluminum containing coatings namely, AlCrN, AlCrNbN, fine grained (fg) AlTiN, and nanocrystalline (nc) AlTiN. Both AlTiN and AlCrN-based coatings are known for their high oxidation resistances and the formation of aluminum oxide surface layers during oxidation [1]. The coating surface textures before and after post-deposition treatment were analyzed by means of the Abbot-Firestone ratio curves in order to study the influence of surface configurations leading to reduced tool wear. A maximum tool life of 150 m was observed for the tool coated with the nc-AlTiN coating.
Effect of Surface Geometry on Stress Generation in Thermal Barrier Coatings During Plasma Spray Deposition
Authors: Ye Guosheng , Basu Soumendra
Published: April 2011

A fully coupled thermo-mechanical finite element model was used to study the buildup of stresses during splat solidification, and to understand the effect of deposition conditions on crack formation during plasma spray deposition. Through the simulation, the locations and magnitudes of maximum stresses were identified, where crack formation would presumably initiate. The model showed that the stresses scaled with the temperature difference between the superheated splat and the substrate. The simulation further showed that the stresses scale with the three geometric parameters, and two independent geometric ratios were defined; ζ (defined as t/λ) and ψ (defined as A/λ). 2D maps of maximum S11 and S22 under different combinations of ζ and ψ were constructed. The mappings showed that only roughness features on the scale of splat thickness were important in providing locations of maximum stress concentration.
Fabricating Neural and Cardiomyogenic Stem Cell Structures by a Novel Rapid Prototyping—the Inkjet Printing Method
Authors: Xu Tao , Gregory Cassie , Molnar Peter , Boland Thomas
Published: April 2011

Direct printing of living cardiomyogenic stem cells and embryonic cortical neurons to generate complex cellular patterns and structures of such cells was demonstrated in the study. Furthermore, the immunostaining analyses and the whole-cell patch clamp recordings showed the cortical neurons grown in the printed cellular patterns and structures maintained their basic cellular functions, including neuronal phenotypes and electrophysiological properties. These results and findings may greatly prompt the inkjet printing method evolving into a viable and cost-effective approach for engineering human neural and cardiac tissues or even organs.
Development of Novel Biodegradable Amino Acid Ester Based Polyphosphazene– Hydroxyapatite Composites for Bone Tissue Engineering
Authors: Sethuraman Swaminathan , Nair Lakshmi S. , Singh Anurima , Bender Jared D , Greish Yaser E. , Brown Paul W. , Allcock Harry R. , Laurencin Cato T.
Published: April 2011

ASTRACT:

Hydroxyapatite formed from low temperature setting calcium phosphate cements (CPC) are currently been used for various orthopaedic applications. CPCs are attractive candidates for the development of scaffolds for bone tissue engineering, since they are moldable, resorbable, set at physiological temperature without the use of toxic chemicals, and can be processed in an operating room setting. However they may have mechanical disadvantages which seriously limit them to non-load bearing orthopaedic applications. The aim of the present study was to develop composites from polyphosphazenes and calcium deficient hydroxyapatite precursors to form poorly crystalline hydroxyapatite-polymer composites. Composites were formed from calcium deficient hydroxyapatite precursors (Ca/P – 1.5, 1.6) and biodegradable polyphosphazenes, poly[bis(ethyl alanato)phosphazene] (PNEA) and poly[(50%ethyl alanato) (50%methyl phenoxy)phosphazene] (PNEA50mPh50) at physiological temperature. The results demonstrated that poorly crystalline hydroxyapatite that resembled the mineral component of bone was formed in the presence of biodegradable polyphosphazenes. The surface morphology of all the four composites was identical with a porous microstructure. The composites supported the adhesion and proliferation of osteoblast like MC3T3-E1 cells making them potential candidates for bone tissue engineering.
Enhanced Osteoblast Functions on Nanophase Titania in Poly-lactic-co-glycolic Acid (PLGA) Composites
Authors: Liu Huinan , Slamovich Elliott B. , Webster Thomas J.
Published: April 2011

Much work is needed in the design of more effective bone tissue engineering materials to induce the growth of normal bone tissue. Nanotechnology offers exciting alternatives to traditional bone implants since bone itself is a nanostructured material composed of nanofibered hydroxyapatite well-dispersed in a mostly collagen matrix. For this purpose, poly-lactic-co-glycolic acid (PLGA) was dissolved in chloroform and nanometer grain size titania was dispersed by various sonication powers from 0 W to 166 W. Previous results demonstrated that the dispersion of titania in PLGA was enhanced by increasing the intensity of sonication and that greater osteoblast (bone-forming cells) adhesion correlated with improved nanophase titania dispersion in PLGA. However, adhesion of osteoblasts to material surfaces, alone, is not adequate to determine long-term functions of implant materials. For this reason, and as a next step to determine the efficacy of nanocomposites in bone applications, subsequent functions of osteoblasts on nanophase titania/PLGA composites were investigated in vitro in this study. For the first time, results correlated better osteoblast long-term functions, specifically the deposition of calcium-containing mineral, with improved nanophase titania dispersions in PLGA.In this manner, the present study demonstrated that PLGA composites with well-dispersed nanophase titania can improve osteoblast functions necessary for the further investigation of these materials in orthopedic applications.
Properties and Applications of Novel DNA-Based Surfactants
Authors: Paunov Vesselin N. , Xu Chun , Taylor Pietro , Ersoz Mustafa , Fletcher Paul D.I.
Published: April 2011

We have designed a novel class of functional surfactants based on DNA and have explored their properties in relation to several possible applications. The DNA-surfactants consist of short chain DNA oligonucleotides covalently bound to a large hydrophobic group, which makes the DNA molecules amphiphilic. We demonstrate that these materials behave like common detergents and are surface-active at various fluid surfaces, e.g. air-water, oil-water interfaces, and lipid bilayers. We also show that once adsorbed the DNA-surfactants remain on the liquid surface upon hybridisation with a complementary DNA chain. We use complementary DNA-surfactants to functionalise fluid surfaces and to program the interactions between them based on Watson-Crick pairing. By selecting the appropriate DNA base sequences, the interaction between the fluid surfaces functionalised with DNA-surfactants can be programmed with a very high specificity. We have also developed a novel procedure for micro-patterning of solid surfaces with DNA by a microcontact printing with aqueous inks of DNA-surfactants which can be utilised for rapid fabrication of DNA assays and genetic biochips.
Alkoxide Based Sol-Gel Processing of CMR Manganites
Authors: Pohl Annika , Westin Gunnar
Published: April 2011

We have prepared a soluble manganese alkoxide, and used in the first all-alkoxide synthesis of Ca, Sr, and Ba substituted lanthanum manganites. The phase development from gel to target oxide was monitored by TGA, DSC, powder-XRD, FT–IR spectroscopy, and TEM-EDS. Here we present the effect of dopant on the phase development. It was found that the dopants influence the temperature of complete oxide formation (≥650°C). The main difference in phase evolution was seen in the 300–600°C range, where the formation of crystalline phases in trace quantities seemed to temporarily reduce the elemental homogeneity.
Magnetic Structure of K2NiF4-type Iron(III) Oxide Halides
Authors: Hector Andrew L.
Published: April 2011

Materials with the K2NiF4 structure and a magnetic atom on the B site are examples of a pseudo-2D square lattice. The nearest neighbour interactions are very strong and, with iron(III), usually lead to xy antiferromagnetic coupling. We have used powder neutron diffraction at 2 K to study the magnetic structures of A2FeO3X where A is Ca or Sr and X is Cl or Br. There are two common magnetic structures for K2NiF4-type xy antiferromagnets, those of La2NiO4 and La2CuO4, here we find the latter. In Sr2FeO3F we find a more complex situation. The reflections corresponding to the La2CuO4 magnetic structure are present from 2 K to ambient temperature, but a further set of peaks decays from 2 K to around 60 K. These correspond to a magnetic structure with a doubled c-axis. This is due to a magnetic structure in which La2NiO4-and La2CuO4-type stacking alternate. To our knowledge this is the only example of this magnetic structure type.
The Rôle of Defects in Photographic Latent Image Formation
Authors: Wilson D. J. , Sokol A. A. , French S. A. , Catlow C. R. A.
Published: April 2011

We report a density functional theory study of the structure and energies of point defects in silver chloride. The localisation of photoelectrons and corresponding holes at these defects has been studied, along with the corresponding relaxation of the lattice. We have applied state-of-the-art periodic and QM/MM embedding methods, to provide new insights into the long-standing problem of the fundamental processes controlling latent image formation.
Ultrafast Laser Processing for Lab-on-a-Chip Device Manufacture
Authors: Sugioka Koji , Cheng Ya , Midorikawa Katsumi
Published: April 2011

3D microstructuring of photosensitive glass is demonstrated by femtosecond (fs) laser for lab-on-a-chip manufacture. True 3D hollow microstructures embedded in the glass are fabricated by the fs laser direct write followed by heat treatment and successive wet etching. A variety of microcomponents for a lab-on-a-chip device like a microfluidics, a microvalve, a microoptics, a microlaser, etc. are fabricated by using this technique. The fs laser direct write process is also applied for selective metallization of internal walls of the hollow microstructures embedded in the glass for electric control of movement of the micromechanical components in the lab-on-a-chip device.
Direct-Write Micro- and Nanostructuring with Femtosecond Lasers
Authors: Chichkov B. N. , Koch J. , Ovsianikov A. , Passinger S. , Reinhardt C. , Serbin J.
Published: April 2011

Our recent progress in the direct-write femtosecond laser material processing technologies, nanostructuring, and fabrication of photonic devices is reviewed. Special attention is given to the sub-wavelength microstructuring of metals and two-photon polymerization (2PP) technique. Formation of microbumps and nanojets on thin metal films under single pulse laser irradiation is discussed. Microstructuring of different photosensitive materials by 2PP technique is demonstrated. Numerous applications of this technology for the fabrication of 3d structures, waveguides, photonic crystals, etc. are studied.
A Bunch of Excellent Properties for Applications of Diode Laser Pumped Solid-State Lasers
Authors: Kreutz E. W. , Poprawe R. , Loosen P. , Hoffmann D.
Published: April 2011

Diode laser pumped solid-state lasers such as rod, disk or slab lasers are on the way to govern as new systems developed in the last years the applications of laser radiation for various applications in innovative technologies. The laser radiation is used either as a tool for materials processing or as a source for radiation generation beside of applications in life science, environment, medicine, analytics, and others. The state-of-the-art of diode laser pumped solid state lasers is described highlighting beam quality, efficiency, mean time between failure, and compactness in order to discuss new laser radiation governed processes aimed for rapid manufacturing by rapid prototyping via selective laser melting, surface cleaning, surface polishing, and generation of EUV radiation.
Producing ultrashort Terahertz to UV photons at high repetition rates for research into materials
Authors: Neil G. R. , Behre C. , Benson S. V. , Biallas G. , Boyce J. , Dillon-Townes L. A. , Douglas D. , Dylla H. F. , Evans R. , Grippo A. , Gruber D. , Gubeli J. , Hernandez-Garcia C. , Jordan K. , Kelley M. J. , Merminga L. , Mammosser J. , Nishimimori N. , Preble J. , Rimmer R. , Shinn M. , Siggins T. , Walker R. , Williams G. P. , Zhang S.
Published: April 2011

A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on a Energy-Recovered, (superconducting) Linac (ERL). The machine has a 160 MeV electron beam and an average current of 10 mA in 75 MHz repetition rate hundred femtosecond bunches.

These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz ∼ half cycle pulse whose average brightness is > 5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20 W of average power extracted[1]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100 fs pulses with >200 W of average power (see G. P. Williams, this conference).

The FELs also provide record-breaking laser power [2]: up to 10 kW of average power in the IR from 1 to 14 microns in 400 fs pulses at up to 74.85 MHz repetition rates and soon will produce similar pulses of 300–1000 nm light at up to 3 kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10 microseconds long at high repetition rates to continuous operation.

The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser vapor deposition, nitriding of metals, and energy flow in proteins. This paper will present the status of the system and discuss some of the opportunities provided by this unique light source for modifying and studying materials.
High Power THz Generation from Sub-ps Bunches of Relativistic Electrons
Authors: Benson S. , Douglas D. R. , Dylla H. F. , Gubeli J. , Jordan K. , Neil G. R. , Shinn M. , Zhang S. , Williams G. P.
Published: April 2011

We describe a > 100 Watt broadband THz source that takes advantage of the relativistic enhancement of the radiation from accelerating electrons according to the formula assigned the name of Sir Joseph Larmor[1, 2]. This is in contrast to the typical 1 milliwatt sources available in a laboratory. Specifically, for relativistic electrons the emission is enhanced by the fourth power of the increase in mass. Thus for 100 MeV electrons, for which the mass increases by a factor of ∼ 200, the enhancement is > 109. The experiments use a new generation of light source called an energy recovery linac (ERL) [3], in which bunches of electrons circulate once, but in which their energy is recovered. In such a machine the electron bunches can be very much shorter than those, say, in storage rings or synchrotrons.

The Jefferson Lab facility operates in new limits of emission from relativistic particles involving both multiparticle coherence and near-field emission in which the velocity (Coulomb) term in the classical electrodynamical theory becomes as important as the acceleration term (synchrotron radiation).

The sub-picosecond pulses of light offer unique capabilities in 2 specific areas, namely time-resolved dynamics, and imaging. High resolution THz spectroscopy has recently revealed sharp vibrational modes for many materials including malignant tissue, proteins, DNA, pharmaceuticals and explosive materials. Energetically the THz range embraces superconducting bandgaps, and regions of intense interest in the understanding of systems in which correlated motions of electrons are important, such as colossal magneto-resistive and high-Tc materials. The very high power levels of the new source will allow non-linear effects to be observed as well as the creation of novel states of materials, including electric-field driven localization[4]. We will give examples of existing work in these areas and present opportunities afforded by the new source.
Three-Dimensional Micro- and Nanofabrication with Multiphoton Absorption
Authors: LaFratta Christopher N. , Farrer Richard A. , Baldacchini Tommaso , Znovena Juliet , Lim Daniel , Pons Anne-Cécile , Pons Josefina , O'Malley Kevin , Bayindir Zeynel , Naughton Michael J. , Saleh Bahaa E. A. , Teich Malvin C. , Fourkas John T.
Published: April 2011

Multiphoton absorption has become a powerful technique for the creation of three-dimensional micro- and nanostructures. Here we review some of our recent progress towards creating functional microdevices with multiphoton absorption. Specific thrusts of our research include development of new resins for multiphoton absorption polymerization, design of novel schemes for metal deposition, and post-fabrication ablation of polymeric structures.
Morphological Manipulation and Plasticization of the Electrostatic Network in Perfluorosulfonate Ionomers
Authors: Phillips Alan K. , Moore Robert B.
Published: April 2011

The addition of small molecule fluorosurfactants to perfluorosulfonate ionomers has been found to have a profound effect on the morphology and mechanical properties of solution processed membranes. Perfluorooctane sulfonates neutralized with both alkali metal and alkylammonium counterions have been incorporated into solution processed Nafion® membranes. Sodium neutralized fluorosurfactants were found to crystallize during membrane casting leading to the formation of a surface layer of crystalline material.

Tetramethylammonium neutralized surfactants behave in a similar fashion with crystallization of the surfactant occurring during casting. The use of large tetrabutylammonium counterions is found to prevent crystallization of the surfactant and create a highly plasticized membrane.
Three Decades of Social Science Research on High‐Level Nuclear Waste: Achievements and Future Challenges
Authors: Solomon Barry D. , Andrén Mats , Strandberg Urban
Published: April 2011

Research on high‐level nuclear waste management has focused on technical and scientific issues since the U.S. National Academy of Sciences first studied the problem in the mid‐1950s and recommended long‐term disposal in deep salt formations. In this review, we trace the development of the problem's definition and its associated research since socioeconomic, political, and policy issues were first given consideration and nuclear waste management became recognized as more than a technical problem. Three somewhat overlapping time periods can be identified. First, from the mid‐1970s to the early 1980s, initial research explored institutional dimensions of nuclear waste, among other subjects, while several countries attempted to officially solve the problem. The second period began in the early 1980s with a concerted effort to site nuclear waste repositories, and ended in the mid‐1990s with some progress in Sweden, Finland, and the United States, and general stalemate elsewhere. This period accelerated research on risk perception and stigma of nuclear waste, and elevated a focus on public trust. Special attention was given to repository siting conflicts in particular. The last period, since the mid‐1990s, has been characterized by failure and continuing political stalemate, with the major exception of Scandinavia, and increased attention to public participation, political systems, and international solutions. Questions of ethics have been given serious attention, while research on risk perceptions and siting conflicts continues. Thus, we see some signs of progress toward final disposal. We frame these periods in a broader context of the shifting role of applied social scientists. The paper concludes with a general discussion of this research area and prospects for future research.
“On the Uses and Disadvantages of History” for Radioactive Waste Management
Authors: Laes Erik , Schröder Jantine
Published: April 2011

In this paper we propose a critical investigation of the epistemological, ontological, and moral foundations for the legitimacy of the (internationally accepted) permanent geological disposal option for high‐level radioactive waste. We do so through a reading of Nietzsche's second untimely meditation, “On the uses and disadvantages of history for life.” In particular, we offer an interpretation of some of the central concepts in this text and Nietzsche's work in general—perspectivism, pluralism, active forgetting, etc.—and investigate the effects of the confrontation between these lines of thought and present practices in the management of medium‐ and high‐level long‐lived radioactive waste (categories B and C). Furthermore, we argue that this untimely meditation comes at a timely moment, i.e., at a time when modernity's way of dealing with waste could be undergoing a major transformation. The paper ends with some preliminary reflections on our nuclear inheritance and its link with nuclear power of the future (GenIV).
The influence of hygienisation of sewage sludge on the process of pyrolysis
Authors: Čížková Adéla , Juchelková Dagmar , Raclavská Helena
Published: April 2011

The influence of hygienisation of sewage sludge on the process of pyrolysis

The aim of this work was to determine the influence of liming on the process of pyrolysis. Three samples of sludge from two wastewater treatment plants were selected for this study on pyrolysis: sludge without liming and limed sludge from the Central Wastewater Treatment Plant in Ostrava and sludge from the Wastewater Treatment Plant in Sviadnov. The samples had different content of calcite (CaCO3). The limed sludge contained 7% of CaCO3, sludge without liming 3.8% and sludge without liming from WWTP Sviadnov contained 0.5% of calcite. The results of laboratory pyrolysis proved that limed sludge released the maximum amount of carbon - 55.46 %, while sludge without liming from WWTP Sviadnov released only 48.92%. Calcite produces during its decomposition CaO and the product influences the pyrolysis process because it supports cracking of volatile organic compounds
Using a Positive Self-Talk Intervention to Enhance Coping Skills in Breast Cancer Survivors: Lessons from a Community-Based Group Delivery Model
Authors: Hamilton Ryan , Miedema B. , MacIntyre L. , Easley J.
Published: April 2011

Purpose: Cancer survivorship is a distinct phase of the cancer continuum, and it can have myriad associated stresses and challenges. The purpose of the present study was to evaluate the effectiveness of a positive self-talk (PST) intervention in enhancing the coping skills and improving the psychological well-being of breast cancer survivors. Methods: Participants (n = 38) were recruited from 5 support groups in a small eastern Canadian province. Support groups were randomly assigned to either a control (n = 18) or an intervention (n = 20) condition. Intervention participants were pre-tested, received a 2-hour PST in-person group workshop and a 10-minute “booster” session by telephone, and completed post-test questionnaires 1 month later. Results: Intervention participants reviewed the workshop favourably. Nearly all participants used the intervention in everyday life, were able to accurately describe how PST works, and found that PST had a considerable impact on their ability to cope with cancer and related sequelae. However, the descriptive findings from the workshop evaluation did not translate into significant differences between the intervention and control groups on the psychometric measures. Conclusions: The PST intervention, delivered in a community group model, was positively received and effective in teaching participants about PST and how PST can be used to enhance coping skills for breast cancer patients. However, the intervention did not promote significantly greater levels of change in anxiety, depression, mood disturbance, or coping ability for intervention participants. The unique challenges of community-level psychological intervention are explored.
Rare Synchronous Primary Large B-cell Gastric Lymphoma and Huge Retroperitoneal Liposarcoma with Inguinal Hernia in Chronic Hepatitis B Patient
Authors: Ghimire P. , Wu Guangyao , Zhu L.
Published: April 2011

Multiple primary neoplasms with synchronous or metachronous presentation are rare, although the incidence has recently increased because of several factors. We present the case of a 53-year-old patient with chronic hepatitis B who presented with abdominal mass, mild abdominal pain, and inguinal hernia. Computed tomography imaging demonstrated diffuse thickening of the gastric antral wall, together with a huge heterogeneous abdominal mass with predominant fat attenuation with septa that showed mild enhancement on contrast-enhanced scans. Distal gastrectomy and wide resection of the retroperitoneal mass was performed. Pathology exam led to a diagnosis of diffuse large B-cell gastric lymphoma with retroperitoneal liposarcoma. This is a rare case of a primary gastric lymphoma with another primary (sarcomatous) malignancy occurring synchronously in same patient.
Study of Mechanical Characterization of Ceramic Specimens from a Brazilian Test Adaptation
Authors: Iglesias I. , Acosta B. , Yu R. , Ruiz G. , Aineto M. , Acosta A.
Published: April 2011

The Brazilian Test is easy to perform and its result is the tensile strength of the material provided certain ratios are fulfilled between the diameter of the sample, the load bearing width and the characteristic length of the material. In this paper we present experimental results obtained from 8 mm-thick ceramic cylinders whose diameter was 40 mm in length. The cylinders were obtained from a standard type of clay by pressing and subsequent baking at 900 ºC. We made a complete mechanical characterization of the material, which included obtaining fracture properties, and a numerical simulation of the Brazilian test based on the cohesive crack model. Numerical results confirm that the size and boundary conditions chosen for the test are adequate to get the actual tensile strength of construction ceramics, which prove that this type of test is useful to compare the strength of several types of construction ceramics in a simple and convenient way. Besides, it requires a very small amount of material to prepare the specimen
The clinical utility of gene testing for Alzheimer’s disease
Authors: Atkins Emily R. , Panegyres Peter K.
Published: April 2011

Alzheimer’s disease (AD) is the largest cause of dementia, affecting 35.6 million people in 2010. Amyloid precursor protein, presenilin 1 and presenilin 2 mutations are known to cause familial early-onset AD, whereas apolipoprotein E (APOE) ε4 is a susceptibility gene for late-onset AD. The genes for phosphatidylinositol- binding clathrin assembly protein, clusterin and complement receptor 1 have recently been described by genome-wide association studies as potential risk factors for lateonset AD. Also, a genome association study using single neucleotide polymorphisms has identified an association of neuronal sortilin related receptor and late-onset AD. Gene testing, and also predictive gene testing, may be of benefit in suspected familial early-onset AD however it adds little to the diagnosis of lateonset AD and does not alter the treatment. We do not recommend APOE ε4 genotyping.
Relationship between Plasma Glucose Levels and Malignant Uterine Cervical Neoplasias
Authors: Nomelini Rosekeila Simõtes , Neto Adriano Souza Lima , Capuci Kalebe Alexandre , Murta Beatriz Martins Tavares , Murta Eddie Fernando Candido
Published: April 2011

Background

There is a direct correlation between glycemic load and the risk of developing many malignant neoplasms.

Aims

The aim of this study was to determine the plasma glucose levels in women with cervical cancer.

Methods

The study included 177 women with anatomopathologically diagnosed uterine cervical cancer (stages 0–IV) treated between 1980 and 2008 at the Gynecology and Obstetrics outpatient service of the UFTM, Brazil. The plasma glucose levels of all patients were assayed at the time of diagnosis and correlated with tumor staging.

Results

We statistically compared the plasma glucose levels of group 1 (cervical intraepithelial neoplasia 2–3), group 2 (stage I–II), group 3 (stage III–IV), and group 4 (control group: leiomyomas). Patient groups with poor prognosis (groups 2 and 3) showed significantly higher plasma glucose levels ( P < 0.05) than those with less aggressive lesions (group 1). Plasma glucose levels were significantly higher in groups 2 and 3 than in group 4 ( P < 0.05). The comparison of number of patients with plasma glucose level >90 mg/dl showed CIN versus I/II: P = 0.0753; OR = 2.018; (95% CI: 0.9236 to 4.410) and CIN versus III/IV: P = 0.0975; OR = 2.400; (95% CI: 0.8335 to 6.911).

Conclusion

We observed an association between high plasma glucose levels and cervical cancer cases with poor prognoses. Plasma glucose tests should be routinely used as additional prognostic parameters in patients with cervical neoplasias.
Oral Health Practices and Oral Cancer Knowledge Attitudes and Behaviors among College Students
Authors: Shanmugavel Aarthi , Shive Steven E
Published: April 2011

Objective

This study examines the knowledge about the risk factors and symptoms of oral cancer, attitudes toward oral cancer and associated behaviors of college students using constructs of the Health Belief Model and the predictors of oral screening of college students.

Participants

College of Health Science students (N = 300) at a State university located in the Northeastern US were surveyed.

Methods

A 25-item questionnaire was administered during the Fall 2009 semester, which measured knowledge and behaviors related to oral cancer risk factors.

Results

Participants perceived their oral health to be good (63.6%), were unaware of dental diseases (95.5%), visited a dentist (60.5%), had a dental visit (62.2%) within the last 6 months, and scheduled one (66.3%) in the next 6 months. There was a significant correlation between the behavior of use of tobacco and the perceived susceptibility to oral cancer (t = 8.10, p < 0.05) and perceived severity (t = 2.22, p < 0.05) if a person got oral cancer. There were no significant variables which predicted oral cancer screening. Having a dental visit best predicted the scheduling of a future dental visit.

Conclusions

Findings from this study may further assist in future health education and dental screening programs for this population group across the US.
Analysis on the impact of aerosol optical depth on surface solar radiation in the Shanghai megacity, China
Authors: Xu J. , Li C. , Shi H. , He Q. , Pan L.
Published: April 2011

Abstract. This study investigated the decadal variation of the direct surface solar radiation (DiSR) and the diffuse surface solar radiation (DfSR) during 1961–2008 in the Shanghai megacity as well as their relationships to Aerosol Optical Depth (AOD) under clear-sky conditions. Three successive periods with unique features of long term variation of DiSR were identified for both clear-sky and all-sky conditions: a "dimming" period from the late 1960s to the mid 1980s, a "stabilization"/"slight brightening" period from the mid 1980s to the mid 1990s, and a "renewed dimming" period thereafter. During the two dimming periods of DiSR, DfSR brightened significantly under clear-sky conditions, indicating that change in atmospheric transparency resulting from aerosol emission has an important role on decadal variation of surface solar radiation (SSR) over this area. The analysis on the relationship between the Moderate-resolution Imaging Spectroradiometer (MODIS) retrieved AOD and the corresponding hourly measurements of DiSR and DfSR under clear-sky conditions clearly revealed that AOD is significantly correlated and anti-correlated with DfSR and DiSR, respectively, both above 99% confidence in all seasons, indicating the great impact of aerosols on SSR through absorption and/or scattering in the atmosphere. In addition, both AOD and the corresponding DiSR and DfSR measured during the satellite passage over Shanghai show obvious weekly cycles. On weekends, AOD is lower than the weekly average, corresponding to higher DiSR and lower DfSR, while the opposite pattern was true for weekdays. Less AOD on weekends due to the reduction of transportation and industrial activities results in enhancement of atmospheric transparency under cloud free conditions so as to increase DiSR and decrease DfSR simultaneously. Results show that aerosol loading from the anthropogenic emissions is an important modulator for the long term variation of SSR in Shanghai.
Yields of oxidized volatile organic compounds during the OH radical initiated oxidation of isoprene, methyl vinyl ketone, and methacrolein under high–NOx conditions
Authors: Galloway M. M. , Huisman A. J. , Yee L. D. , Chan A. W. H. , Loza C. L. , Seinfeld J. H. , Keutsch F. N.
Published: April 2011

Abstract. We present first-generation and total production yields of glyoxal, methylglyoxal, glycolaldehyde, and hydroxyacetone from the oxidation of isoprene, methyl vinyl ketone (MVK), and methacrolein (MACR) with OH under high NOx conditions. Several of these first-generation yields are not included in commonly used chemical mechanisms, such as the Leeds Master Chemical Mechanism (MCM) v. 3.1. Inclusion of first-generation production of glyoxal, glycolaldehyde and hydroxyacetone from isoprene and methylglyoxal from MACR greatly improves performance of an MCM based model during the initial part of the experiments. In order to further improve performance of the MCM based model, higher generation glyoxal production was reduced by lowering the first-generation yield of glyoxal from C5 carbonyls. The results suggest that glyoxal production from reaction of OH with isoprene under high NOx conditions can be approximated by inclusion of a first-generation production term together with secondary production only via glycolaldehyde. Analogously, methylglyoxal production can be approximated by a first-generation production term from isoprene, and secondary production via MVK, MACR and hydroxyacetone. The first-generation yields reported here correspond to less than 5% of the total oxidized yield from isoprene and thus only have a small effect on the fate of isoprene. However, due to the abundance of isoprene, the combination of first-generation yields and reduced higher generation production of glyoxal from C5 carbonyls is important for models which include the production of the small organic molecules from isoprene.
Evaluating the impacts of land use changes on hydrologic responses in the agricultural regions of Michigan and Wisconsin
Authors: Nejadhashemi A. P. , Wardynski B. J. , Munoz J. D.
Published: April 2011

Abstract. Hydrologic fluxes in the Great Lakes region have been altered relative to pre-settlement conditions in response to major land use changes during the past 150 yr. Land surface characteristics and processes including leaf area index, roughness, albedo, soil moisture, and rates of momentum, energy and water vapor exchange are strongly influenced by land use. Changes in land use including urbanization and de(/re)forestation continue to affect the nature and magnitude of groundwater – surface water interactions and water availability influencing ecosystems and their services. One of the goals of the present work is to develop a baseline scenario relative to which the impacts of land use changes on hydrological and environmental processes can be evaluated. In addition, the study can help in quantifying the potential impacts of future projected changes in land use in order to mitigate the negative impacts of these changes on goods and services of value to society. The present study explores the relationship between land use changes and hydrologic indicators within the agricultural regions of Michigan and Wisconsin. Two sets of land use data, the circa 1800 County Base and the 2001 National Land Cover Dataset, were used to setup the Soil and Water Assessment Tool (SWAT) model. First, sensitivity analyses were performed both based on pre-settlement and current land use scenarios and the most sensitive parameters were identified. Then, the model was calibrated against measured daily stream flow data obtained from eight United States Geological Survey gauging stations. The impacts of land use changes were studied at three scales: subbasin-level, watershed-level, and basin-level. At the subbasin level, most of the hydrologic behavior can be described by percent change in land cover. At the watershed scale, significant differences were observed based on the long-term average hydrologic fluxes under the current and pre-settlement scenarios. In addition, an overall increase in the amount of evapotranspiration and overland flow and overall decrease in the amount of baseflow and water yield were observed. However, at the basin-level, the majority of the area experienced increased overland flow, decreased baseflow, lateral flow, and recharge to aquifers, and minor changes in evapotranspiration and water yield.
Ranibizumab in Retinal Angiomatous Proliferation (RAP): Influence of RAP Stage on Visual Outcome
Authors: Reche-Frutos Juan , Calvo-Gonzalez Cristina , Pérez-Trigo Silvia , Fernandez-Perez Cristina , Donate-Lopez Juan , Garcia-Feijoo Julian
Published: April 2011

Purpose.

To evaluate the influence of retinal angiomatous proliferation (RAP) stage on visual and anatomic outcome after ranibizumab (Lucentis®).

Methods.

This was a prospective study on consecutively diagnosed RAP eyes at the Hospital Clínico San Carlos, Madrid. Best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) are performed monthly. Indocyanine green angiography (ICG) and fluorescein angiography (FA) are performed at baseline and every 3 months thereafter. A starting dose of a monthly ranibizumab injection in the first 3 months is followed by retreatment in case of intraretinal edema, subretinal fluid, or pigment epithelium detachment (PED) in OCT, increased leakage in FA, or a hot spot in ICG.

Results.

A total of 53 eyes from 49 patients were included. The mean change in BCVA at 12 months was +7.3, +0.83, and −2.1 letters in stages IIA (21 cases), Il B (18 cases), and III (14 cases), respectively. After adjusting the change in BCVA according to baseline BCVA, β coefficient was −6.012 letters (p=0.025) in stage IIB and −9.762 letters (p=0.003) in stage III vs stage IIA. Four cases had a retinal pigment epithelium tear after injection of ranibizumab.

Conclusions.

Patients in stage II without PED have a better visual and anatomic evolution than patients in stage II with PED and stage III.
Allogenic Labral Transplantation in Hip Instability following Arthroscopic Labrectomy
Authors: Tey Marc , Erquicia Juan I. , Pelfort Xavier , Miquel Joan , Gelber Pablo E. , Ribas Manuel
Published: April 2011

The acetabular labrum augments femoral head coverage within the acetabulum and contributes to hip joint stability. This has led to an increasing interest in procedures dedicated to preservation of the labrum. An allogenic labral transplantation performed in a patient who had previously undergone a partial labral resection is presented.
Improved Tank in Series Reactor Model for Tubular Solid Oxide Fuel Cell Stacks
Authors: Danilov V. A. , Vijay P. , Tade M. O.
Published: April 2011

An improved tank in series reactor model for the tubular solid oxide fuel cell stack is presented. The model accounts for the charge balances in the electrodes and electrolyte in addition to the component and energy balances, and is used to simulate the potentiostatic operation of the stack. Moreover, the time required for simulating this model is much less compared to the more elaborate three‐dimensional models in the literature. The results demonstrate a strong coupling between the temperature, concentration and current density distributions.
Determination of the Mechanical Variation in Stress of Transient Adsorption Plants
Authors: Steinbach Hendrik , Ferstl Johann , Platzer Bernd
Published: April 2011

In stark gekoppelten Adsorberstationen herrscht während des Betriebs ein instationärer Prozess durch den kontinuierlichen Wechsel zwischen Adsorption und Desorption. Aufgrund des konträren Verhaltens werden zeitlich variierende mechanische Spannungen in den Bauteilen erzeugt und wieder abgebaut. Es wird eine Vorgehensweise vorgestellt, um die Spannungsverläufe an den kritischen Stellen mit ausreichender Näherung zu bestimmen und dabei den Rechenaufwand stark zu minimieren. Aufgrund der genaueren Erkenntnisse über Schwingbreite und Lastzyklen ist es zusätzlich möglich, die Komponenten einer Adsorptionsanlage bezüglich Schädigung nach der Methode von Miner und Palmgren qualitativ besser zu bewerten. Die neue Beurteilung geht konform mit dem ASME‐Code oder dem AD‐Regelwerk.