bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction of Triangular Defects on 100mm 4° off-axis 4H-SiC using a Chloride Based CVD process
Authors: Das Hrishikesh , Sunkari Swapna , Oldham Timothy , Rodgers Josh , Casady Janna
Published: November 2012

Homoepitaxial layers were grown with very low surface roughness on 4", 4˚ off-axis substrates, but a new kind of large obtuse angled triangular defect that spanned 1000-2000 μm was observed. Process changes resulted in reduction of the size and concentration of these triangular defects from 3.5cm-2 to 0.13cm-2. Both large and small triangular defects were found to have a similar core structure. No degradation in the epitaxial morphology or quality was seen due to the process change. JBS diodes fabricated on wafers with large triangular defects had much higher leakage when the triangular defects were present in the active area of the diodes.
A New Family of Light Emitting Si Nanoparticles
Authors: Shirahata Naoto
Published: November 2012

Color-tuning of UV luminescent silicon nanocrystals (Si NCs) was successfully achieved by precise size control of non-oxidized NCs. The alkoxy-capped Si NCs was synthesized via sodium biphenylide reduction of SiCl4 encapsulated with inverse micelles, and subsequent alkoxylation of surface Si-Cl bonds. Due to the high molecular packing density of alkoxy monolayers, outermost surface of the NCs was completely protected from oxidation even under ambient conditions. Interestingly, the optical absorption and emission spectra were blueshifted with reduction of non-oxidized NC size, and we found strong light emission in the UV range when the NCs were smaller than 2.5 nm. More than 20% of PL quantum efficiencies (QYs) were estimated from those UV luminescent NCs. Monodispersed NCs without oxide can provided narrow PL spectra with 35-40 nm of line-widths, while the presence of oxidized surface region of NCs led to the broad PL spectra. In addition, the redshift of PL spectra were observed from the partially-oxidized NCs which were formed due to the lower surface molecular coverage, suggesting the significant difference in optical transition of photogenerated carriers between the non-oxidized and the partially-oxidized NCs. This can be well-illustrated by comparing decay profiles of the carriers for each sample through the time-resolved PL spectroscopic observation.
Improved conductivity of ZnO thin films by exposure to an atmospheric hydrogen plasma
Authors: Illiberi A. , Kniknie B. , van Deelen J. , Steijvers H.L.A.H. , Habets D. , Simons P.J.P.M. , Janssen A.C. , Beckers E.H.A.
Published: November 2012

Aluminum-doped zinc oxide (ZnOx:Al) films have been deposited on a moving glass substrate by a high throughput metalorganic chemical vapor deposition process at atmospheric pressure. Thin (< 250 nm) ZnOx:Al films have a poor crystalline quality, due to a small grain size and the presence of different crystallographic orientations. The crystalline quality improves with increasing film thickness (from 50 nm to 1000 nm), resulting in a lower value of resistivity (from 100 Ohm cm to 1·10-3 Ohm cm, respectively). We have investigated the variation in the films’ conductivity and transparency induced by a post-deposition exposure to a He/H2 atmospheric plasma. The resistivity of thin (< 250 nm) films is found to decreased sharply from 100 Ohm cm to about 4·10-3 Ohm cm by a short (∼ seconds) plasma exposure, while the resistivity of thicker films remains unaffected.
All Hot Wire CVD Organic/Inorganic Hybrid Barrier Layers for Thin Film Encapsulation
Authors: Spee Diederick A. , Schipper Merijn R. , van der Werf Karine H.M. , Rath Jatindra K. , Schropp Ruud E.I.
Published: November 2012

A water vapor barrier layer is presented that is deposited entirely at temperatures below ∼100oC. Our method, using hot wire chemical vapor deposition (HWCVD), is effective in reducing the issue of pinholes in single layers of silicon nitride (SiNx) made at such low substrate temperatures. We succeeded in depositing an all hot-wire simple three-layer structure consisting of two low-temperature SiNx layers with a polymer layer in between, exhibiting a water vapor transmission rate (WVTR) as low as 5*10-6 g/m2/day, determined at a temperature of 60°C and a relative humidity of 90%. This WVTR is low enough for organic and polymer devices. In a second experiment the robustness of the barrier layer is shown with respect to environmental dust.
Rare Earth Nanocomposites Based on Chitosan Platforms for Biological Applications
Authors: Yasmin Zannatul , Zhang Maogen , Gorski Waldemar , Maswadi Saher , Glickman Randolph , Nash Kelly L.
Published: November 2012

Chitosan (CHIT), a natural biopolymer, has established its applicability in numerous studies including, tissue scaffolds, topical antimicrobial agents, glucose biosensors and drug delivery platforms. Among these applications, biosensors utilizing CHIT has been championed due its excellent film-forming ability, biocompatibility, good adhesion, non-toxicity, and susceptibility to chemical modification due to the presence of plentiful amino groups and hydroxyl groups. The challenge in development of many biosensing materials is that they should offer robust and tunable characteristics (fluorescence, magnetic, thermal, etc.) while remaining biocompatible. In this work, a facile method was developed to synthesize biocompatible hetero-nanoparticles which inherently display multifunctionality based on a few interchangeable components. As an example, we present a system composed of rare earth metal oxide (REMO) nanoparticles, Er doped Y2O3, with the attachment of gold nanostructures using CHIT. The resulting REMO@CHIT@Au0 hybrid nanoparticles are capable of displaying tunable optical properties due to the surface plasmon resonance of the gold nanoparticles useful to photoacoustic applications. An overview of the nanostructure components are given followed by morphological and spectroscopic analyses. The results of the characterizations are the focus of our future work towards the applicability of these systems to biological sensing, detection and contrast agents.
Raster Scanning Laser and UV Processing of nanocrystalline TiO2 Films for Sintering in Dye Solar Cells: Device Performance, Throughput and Embodied Energy
Authors: Mincuzzi Girolamo , Zardetto Valerio , Vesce Luigi , Schulz-Ruhtenberg Malte , Gillner Arnold , Reale Andrea , Di Carlo Aldo , Brown Thomas M.
Published: November 2012

A crucial step in Dye Solar Cell (DSC) fabrication is the sintering of the TiO2 layer which needs to guarantee good electromechanical bonding between nanoparticles whilst maintaining sufficiently large porosity to yield performing devices. The standard procedure for TiO2 sintering requires firing in an oven at ∼ 500°C. An alternative procedure consists in utilizing laser scanning processing which has the advantageous potential of being noncontact, local, low cost, rapid, selective, automated and scalable. We analyzed and optimised a laser process for the sintering of the TiO2 layers in dye solar cells analyzing temperature profiles, throughput and the embodied energy. The development of electronic and photovoltaic devices on plastic substrates is of considerable interest due to the advantages they bring in terms of flexibility and easy processing for lightweight, low-cost large-area applications. An alternative sintering procedure compatible with flexible substrates and large area processing consists in utilizing a UV lamp. We subjected TiO2 pastes deposited on conductive transparent substrates to UV irradiation. Fully plastic devices fabricated through this method showed efficiencies of 4%.
In situ spectroscopic characterization of some LaNi1-xCoxO3 perovskite catalysts active for CH4 reforming reactions
Authors: Pereñiguez Rosa , Gonzalez-Delacruz Victor M. , Ternero Fatima , Holgado Juan P. , Caballero Alfonso
Published: November 2012

Lanthana-supported Ni and Co catalysts were investigated by “operando” techniques (XAS and APPES) for methane reforming reactions. The samples were prepared by the “solid phase crystallization” method (spc), where the precursors La(Ni1-xCox)O3 contains homogeneously distributed metals (Ni, Co) in the crystal structure (perovskite), which, on further reduction, result in the formation of catalytic system Ni1-xCox/La2O3. The monometallic samples (NiLaO3, CoLaO3) have been compared with a bimetallic system of an intermediate composition Ni0.5Co0.5LaO3. This “operando” study has allowed us to obtain important conclusions about the bimetallic particles and the metal-support interactions. The data revealed the formation of bimetallic particles (NiCo); on these ones, the Ni avoids the Co oxidation during the reaction. However, this protection does not induce an improvement in the activity, which presents an intermediate behaviour between Ni/La2O3 and Co/La2O3. These bimetallic particles form a pseudo-alloy with the surface enriched in cobalt (under reduced conditions), resulting nearly in a core-shell structure (Ni@Co).
Hydrogen-Vacancy Effects in Pu-2 at. % Ga Alloys
Authors: Schwartz Daniel S. , Richmond Scott , Smith Alice I. , Costello Alison , Taylor Christopher D.
Published: November 2012

Plutonium and Pu-Ga alloys have been observed to have anomalous hydrogen solubility behavior, including a significant concentration dependence of hydrogen diffusivity in the dilute regime, a sharp drop off in the hydrogen solubility constant in the dilute regime, and a near complete absence of change in the Sieverts’ constant as the alloys are heated across phase transformation boundaries. We are investigating the possibility that a vacancy mechanism is responsible for this behavior. X-ray diffraction measurements show a 0.14% lattice contraction in Pu-2 at. % Ga alloys when they are charged with ~2 at. % hydrogen. The lattice re-expands when the hydrogen is removed. Density functional calculations show that increasing the number of hydrogen atoms associated with a vacant lattice site in Pu lowers the energy of the hydrogen-vacancy complex. These observations support the idea that vacancies are stabilized by hydrogen in the Pu lattice well beyond their thermal equilibrium concentration and could be responsible for the anomalous hydrogen response of Pu.
In-Situ Raman Spectroscopy Studies of Room-Temperature and Hydrothermal Reactions
Authors: McGrail Brendan T. , Jouffret Laurent J. , Villa Eric M. , Burns Peter C.
Published: November 2012

By contracting with the Parr Instrument Company and Bruker Optical Systems, we have developed a system for continuous monitoring of hydrothermal and room temperature reactions by Raman spectroscopy. Using the uranyl peroxide cage cluster {[UO2(O2)(OH)]16[UO2(OM)2]4}24- (denoted {U20R}) and a coordination polymer made from uranyl ions and 4,4’-biphenyldicarboxylate as model systems, we demonstrate the spectroscopically observable changes associated with reaction progress and crystallization.
Carbon Effect on Thermal Ageing Simulations in Ferrite Steels
Authors: Nouchy Fabio , Claisse Antoine , Olsson Pär
Published: November 2012

Two major causes of hardening and subsequent embrittlement in ferrite steels are the spinodal decomposition of the binary Fe-Cr solid solution and the carbide formation due to the presence of carbon as foreign interstitial atoms. In the present work, simulations of the microstructure evolution due to thermal ageing are performed by means of a kinetic Monte Carlo code and using a state-of-the-art interatomic potential based on density functional theory (DFT) predictions and experimental data. The main issues concern the possibility to perform thermal ageing simulations in an acceptable computational time frame and to reproduce a realistic behavior of carbon kinetics and carbide formation. The simulations on the binary system show the microstructural evolution during thermal ageing and allowed to find an exponential trend related to the acceleration as a function of temperature. With the insertion of carbon in the model, the chromium precipitation tends to accelerate. The carbon clustering, analyzed separately, is faster with higher C concentrations and in lattices with segregated chromium.
Surface analytical study of uranium exposed to low pressures of hydrogen at ∼ 80°C
Authors: Harker Robert M. , Chohollo Afiya H.
Published: November 2012

Identical samples of uranium coupons were prepared and each exposed to hydrogen for different times (where this time is significantly less than a classically understood ‘induction time’). Samples were prepared from rolled depleted uranium stock: as-received oxide was removed on all surfaces and two faces (~12x12 mm) were polished to a sub-micron standard. Samples were individually taken through a Vacuum Thermal Pre-Treatment cycle from room temperature to 200°C to the reaction temperature (80°C) over 40 hours and subsequently exposed to 10 mbar O2 for 24 hours. After O2 was removed, the samples were exposed to hydrogen for pre-determined times of up to 48 minutes. Examination of the samples by Scanning Electron Microscopy (SEM) has, as expected, identified small features protruding from the surface believed to have been caused by sub-surface precipitation of UH3. In general these features are circular and isolated from each other, have a diameter of less than 3μm and appear as either ‘flat-topped’ or ‘domed’ morphology. In addition, longer time exposure samples show a predominance of ‘area attack’ where coalesced sub-surface precipitation appears to be confined to particular metal grains. X-Ray Diffraction (XRD) data show an increase in the quantity of UH3 with time.
Pre-eminence of the Indirect Channel in the Resonant Inverse Photoelectron Spectroscopy of Cerium Oxide
Authors: Tobin J. G. , Yu S.-W. , Chung B.W. , Waddill G.D.
Published: November 2012

A strong resonance in the inverse photoelectron spectroscopy (IPES) of cerium oxide was reported recently. Here, it is shown that dominance of the indirect channel of the resonant inverse photoelectron spectroscopy (RIPES) is so complete that the photon energy dependence can be explained in terms of emission associated with a single photon energy.
The High-Temperature Phonon Anomalies of α-uranium.
Authors: Riseborough Peter S.
Published: November 2012

There is a growing body of evidence that a number of mixed-valent and heavy-fermion materials show renormalized hybridization gaps either at the Fermi-energy or close to the Fermi-energy. In the former case, a heavy-fermion semiconducting state occurs and in the later case, the system remains metallic at low temperatures. The magnitudes of the hy-bridization gaps are observed to decrease with increasing temperature. The existence of a low-energy electronic energy scale creates a possibility that the Born-Oppenheimer ap-proximation may fail and that there may be a resonant coupling between the phonons and the electronic excitations. Here we argue that such a mechanism may be the cause of the phonon anomalies observed in neutron scattering experiments on the high-temperature phase of alpha-uranium.
An electron microscopy study on the Zr oxides formed during the transition to breakaway oxidation
Authors: Park Dong Jun , Choi Byoung Kwon , Park Jeong Yong
Published: November 2012

In order to characterize the microstructure of oxide layers formed on Zircaloy-4 tubes during the breakaway transition, oxidation tests in a flowing steam environment were performed at 1000°C with a different oxidation time. It was found that breakaway oxidation occurred after the oxidation time of 3000s, and zirconium dioxide layers existed in two mixed crystallographic forms of the tetragonal and monoclinic phase in all samples. The zirconium oxide layers showed enhanced crystallinity, increase in grain size, and fine pores at the grain boundary after breakaway oxidation. We found that the initiation of breakaway-oxidation instability originated from these microstructural changes.
Spin Fluctuation, Orbital States and Non-conventional Superconductivity in Actinides Compounds
Authors: Kambe S. , Sakai H. , Tokunaga Y.
Published: November 2012

In d-wave unconventional superconductors, superconducting Cooper pairs are believed to be formed via magnetic fluctuations. In fact, the superconducting transition temperature Tc roughly correlates with the antiferromagnetic spin fluctuation energy in d-wave unconventional superconductors including high Tc cuprates. In addition to this correlation, the superconducting pairing symmetry and the magnetic anisotropy of the normal state are found empirically to be strongly correlated in f-electron unconventional superconductors having crystallographic symmetry lower than cubic. In antiferromagnetic systems, unconventional superconductivity appears with singlet (d-wave) pairing for cases of XY anisotropy. In contrast, in ferromagnetic systems, unconventional superconductivity with triplet (e.g. p-wave) pairing appears for cases of Ising anisotropy. In this report, the d-wave case is addressed, the origin of XY anisotropy is discussed in terms of the orbital character; and the angular momentum character jz for each piece of Fermi surfaces is determined.
In situ AFM and XPS Investigation of U6+ Reduction by Fe2+ on Hematite and Pyrite
Authors: Niu Jingjie , Becker Udo , Ewing Rodney
Published: November 2012

Uranyl adsorption/reduction by Fe2+ on hematite and pyrite has been studied at neutral pH under anoxic and CO2-free conditions. XPS results confirm that more U3O8 precipitates on hematite than on pyrite reacted for 24 h in 160 μM uranyl nitrate and 160 μM Fe2+ solution at initial pH 7.3. These results are explained in terms of co-adsorption energy and U atom Mulliken charge transfer by quantum mechanical calculations. Moreover, in situ fluid tapping-mode AFM experiments on hematite indicate a deceleration of the U reduction rate within 24 h due to the passivation of the surface caused by the formation of orthorhombic U3O8 crystals. In addition, crystals observed using AFM show morphologies of orthorhombic schoepite appearing on hematite after 5 h.
Electron Microscopy and Raman Spectroscopy Study of Pu-Bearing LaBS Glasses
Authors: Stefanovsky S.V. , Shiryaev A.A. , Vlasova I.E. , Yapaskurt V.O. , Marra J.C.
Published: November 2012

Two LaBS glasses containing 9.5 wt.% (#1) and 5.0 wt.% PuO2 (#2) were prepared by melting in Pt ampoules at 1500 C and examined by scanning electron microscopy with energy dispersive X-ray spectroscopy. The bulk of sample #1, both as-prepared and stored for 3 yrs, was amorphous with homogeneous PuO2 distribution. Sample #2, especially after storage for 2-3 yrs, was partly devitrified primarily in the near-surface area. As followed from X-ray elemental maps, the vitreous phase was enriched with Al and Si whereas larger elongated and smaller dendrite crystals strongly enriched with rare earths (La, Nd, Gd) and Si and minor amounts of Hf may be attributed to britholite. A minor concentration of Pu was also observed in this phase. Moreover, relatively minor amounts of white regular crystals with high PuO2 and lower HfO2 contents were observed in the samples and are probably associated with PuO2 and a PuO2-HfO2 cubic solid solution phase. Nevertheless, even in devitrified areas of the samples, the majority of the Pu remained in the vitreous phase where it was homogeneously distributed.
Actinide Complexation with Biomimetic Phosphorylated Molecules
Authors: Safi Samir , Charbonnel Marie Christine , Creff Gaelle , Jeanson Aurélie , Mostapha Sarah , Roques Jerome , Simoni Eric , Solari Pier , Vidaud Claude , Den Auwer Christophe
Published: November 2012

Most data available on the interaction of actinides with biological systems are based on physiological or biokinetic measurements, with scarce information on the structure of the actinide coordination site. This proceeding article describes an approach for structural elucidation of actinide biological complexes. Indeed most of c.a. actinide circulation pathways are unknown, as they accumulate mostly in bones, kidney and liver. In case of accidental release of radionuclide in the environment, internal contamination under either acute or chronic conditions has the potential to induce both radiological and chemical toxicity through significant interaction with the metabolome or proteome followed by possible functional modifications. For instance, the metalloproteins present primary, secondary and tertiary structures, and also different post-translational modifications, all playing a crucial role in interacting with their partners, which can be altered by actinide bonding. When tightly bound, metal ions are critical to the function, structure, and stability of the proteins, by disabling specific interactions through significant local or global conformational modifications. In order to overcome the intricacy of actinide chemistry combined with that of metalloproteins, a simplified study toward better understanding the interaction of actinides and biological systems using simple biomolecules such as amino acids has therefore been considered. Focus is made on the cation coordination site itself, given that conformational effects are not taken into account in this approach. In a first step, we have selected simple phosphorylated building blocks that may be considered as chemical representatives of some ubiquitous target metalloproteins or some important phosphorylated peptides or proteins.
Materials specific electronic correlation effects and spectral weight ‘hot spots’ in intermetallic actinides
Authors: Das Tanmoy , Zhu Jian-Xin , Durakiewicz Tomasz , Joyce John J. , Graf Matthias J.
Published: November 2012

Many metallic actinide systems host partially filled 5f electrons in the low-energy spectrum. Consequently, they exhibit diverse quantum mechanical phenomena such as magnetism, superconductivity, a mysterious hidden-order phase, or heavy-fermion behavior. Here we present results of a unified theoretical method based on the self-consistent GW formalism for the electronic many-body self-energy. We calculate the dynamic electronic correlation spectra starting from materials specific first-principles electronic band-structure. In particular, we present results for four isostructural intermetallic actinides PuCoIn5, PuCoGa5, PuRhGa5, and UCoGa5. A common underlying property of these materials is a strong spin–orbit coupling split band structure that enables substantial spin fluctuations. In a feedback effect on the electronic structure they create electronic ‘hot spots’, where the single-particle spectral weight is maximum, resulting in a universal peak-dip-hump feature. These results are in good agreement with experiments, suggesting that actinides are adequately described by the intermediate Coulomb interaction regime, where both itinerant (peak) and localized (hump) features coexist.
Experimental verification of a stay cable delta frame model
Authors: Nimse Parag S. , Nims Douglas K. , Helmicki Arthur , Hunt Victor J.
Published: November 2012

The accuracy of a finite-element model depends on the assumptions made during modelling. A combined experimental and analytical approach which uses a minimum of expensive instrumentation and construction loading to verify the modelling assumptions and validate the mathematical model was used to study a delta frame on the Veterans′ Glass City Skyway (VGCS). The VGCS is a twin segmental box girder cable-stayed bridge with three lanes in each direction located in Toledo, Ohio. The delta frame is a complex and critical element of the bridge that transfers loads from the box girders to the stay cables. It was instrumented with a sparse array of strain gauges. A small number of strain gauges were placed in regions of expected high strain. The model was calibrated using the prestressing loads and was used to investigate potential cracking during construction of the delta frame and was incorporated in a larger model of the entire bridge. The accuracy of the work was confirmed by inspection for cracking and strain measurements on the completed bridge.
Monitoring and repair of an impact damaged prestressed bridge
Authors: Pakrashi Vikram , Harkin Julie , Kelly Joe , Farrell Aidan , Nanukuttan Sreejith
Published: November 2012

This paper details the monitoring and repair of an impact damaged prestressed concrete bridge. The repair was required following an impact from a low-loader carrying an excavator while passing underneath the bridge. The repair was carried out by preloading the bridge in the vicinity of the damage to relieve some prestressing. This preload was removed following the hardening and considerable strength gain of the repair material. The true behaviour of damaged prestressed concrete bridges during repair is difficult to estimate theoretically due to a lack of benchmarking and inadequacy of assumed damage models. A network of strain gauges at locations of interest was thus installed during the entire period of repair. Effects of various activities were qualitatively and quantitatively observed. The interaction and rapid, model-free calibration of damaged and undamaged beams, including identification of damaged gauges, were also probed. This full-scale experiment is expected to be of interest and benefit to the practising engineer and the researcher alike.
Design and construction of Zambezi River Bridge, Mozambique
Authors: Reis António J. , Oliveira Pedro José J. , Dalili Behnam
Published: November 2012

The Zambezi River Bridge between Caia and Chimuara is one of the longest and most important bridges built in Africa in recent years. The 2376 m long bridge provides a vital connection between the south and north of Mozambique, substituting the ferry connection to the national road 1 that has existed for almost 50 years. The topography of the site, the deep foundations, the size and significance of the river channel and the environmental sensitivities shaped almost every aspect of the bridge design and construction presented here, including the route selection, the structural forms and the construction methods.
Upgrade of London Underground Bridge D70: Chiswick Park
Authors: Chan Karl
Published: November 2012

Bridge D70 is a single-span steel plate girder bridge dating from the 1930s. It carries four tracks of London Underground's District and Piccadilly lines, the latter being one of the capital's main rail links to Heathrow Airport. Situated next to Chiswick Park tube station the bridge spans over a busy traffic route. This paper describes the project as part of the public private partnership contract to modernise the London Underground system. The paper describes the reasons why upgrading of the existing structure was chosen over complete renewal. The primary aims during the works were to avoid unnecessary closure of the railway line, to minimise the risk of unplanned disruption and to protect the safety of the travelling public. The paper explains the method of construction and the constraints on carrying out work to an existing bridge while in service to passenger trains. This required the extensive use of temporary works to support the tracks. It also describes the challenges in refurbishing a bridge in a residential area in terms of access to the site and reducing the environmental impact of the work. The designer and project manager was Metronet Rail SSL, and the main contractor was Edmund Nuttall (BAM Nuttall).
Briefing: French bridge elegance and the future
Authors: Virlogeux Michel
Published: November 2012

Innovative and elegant bridges such as the Pont de Normandie and Millau Viaduct may be the last of their kind in France. This is due to a combination of reduced funding, growing environmental pressures, delegated design responsibility and decreasing central government involvement.
Retrofit versus new-build house using life-cycle assessment
Authors: Grath Teresa Mc , Nanukuttan Sreejith , Owens Kieran , Basheer Muhammed , Keig Peter
Published: November 2012

This paper reports the findings of research on the environmental performance of two case-study houses, a retrofit and new build. The retrofit was completed to a Passivhaus standard while the new build was completed to current Irish building regulations. Environmental performance of the retrofit and new build was measured using life-cycle assessments, examining the assembly, operational and end-of-life stage over life spans of 50 and 80 years. Using primary information, life-cycle assessment software and life-cycle assessment databases the environmental impacts of each stage were modelled. The operational stage of both case studies was found to be the source of the most significant environmental damage, followed by the assembly and the end-of-life stage respectively. The relative importance of the assembly and end-of-life stage decreased as the life span increased. It was found that the retrofit house studied outperformed the new build in the assembly and operational stage, whereas the new build performed better in the end-of-life stage; however, this is highly sensitive, depending on the standards to which both are completed. Operational energy savings pre- and post-retrofit were significant, indicating the future potential for adoption of high-quality retrofitting practices.
Design and construction of stations on the East London line
Authors: Duffy Rob , Williamson Chris , Kimbell Tom
Published: November 2012

This paper describes the design and construction of the two smaller ‘new-build' stations on the northern section of the new East London line recently constructed in central London. The stations were heavily influenced by the environment in which they were built and the structures they adjoined. Hoxton station was constructed under the existing nineteenth century masonry arches, which underwent significant analysis as part of the design, while at Haggerston, where they were assessed to be unsuitable, the new station was constructed under a new arch replacement structure.
Effect of Maxillary Sinus Membrane Perforation on Vital Bone Formation and Implant Survival: A Retrospective Study
Authors: Froum Stuart J. , Khouly Ismael , Favero Giovanni , Cho Sang‐Choon
Published: November 2012

Background: The maxillary sinus augmentation procedure (SAP) using the lateral window technique has been documented to be a highly predictable procedure. However, the most common intraoperative complication has been reported to be maxillary sinus membrane perforation (MSMP). The present study evaluates the percentage of vital bone and implant survival in sinuses that had perforations repaired during surgery versus a non‐perforated sinus group.

Methods: Data were obtained retrospectively from an Institutional Review Board–approved anonymous database at New York University, Kriser Dental Center, Department of Periodontology and Implant Dentistry, New York, New York, from 23 patients who had undergone SAP with a total of 40 treated sinuses. Sinuses were grafted with mineralized cancellous bone allograft, anorganic bovine bone matrix, or biphasic calcium phospate. Perforation complications occurred in 15 sinuses with 25 non‐perforated sinuses. All perforations were repaired during surgery with absorbable collagen membrane barriers. Histologic cores were taken from all treated sinuses 26 to 32 weeks after surgery. The implant success rate of 79 placed implants was recorded.

Results: The average percentage of vital bone was 26.3% ± 6.3% in the perforated (repaired) sinuses versus 19.1% ± 6.3% in the non‐perforated sinuses. The differences were statistically significant (SS). The implant success rate was 100% (35 of 35) compared to 95.5% (43 of 45) in the perforated/repaired vs. non‐perforated sinuses, respectively. There was no SS difference in implant failure rates.

Conclusions: The augmented sinuses in this study that exhibited MSMPs that occurred during the SAP (which were treated during surgery) show SS greater vital bone percentages compared with the non‐perforated sinus group. There were no SS differences in implant survival in the perforated versus non‐perforated groups. In this study, sinus MSMPs, when properly repaired during surgery, do not appear to be an adverse complication in terms of vital bone production or implant survival.
Predictive Power of the Severity Measure of Attachment Loss for Periodontal Care Need
Authors: Liu Honghu , Marcus Marvin , Maida Carl A. , Wang Yan , Shen Jie , Spolsky Vladimir W.
Published: November 2012

Background: The prevalence of periodontal diseases is high, and >15% of adults have severe gum disease. Clinical attachment loss (AL) is one of the most important measures for periodontal disease severity. With AL, one could measure the worst scenario, the average, or the cumulative sum of AL among all teeth. The objective of this study is to evaluate which of the 15 measures of periodontal problems (e.g., maximum, mean, and cumulative AL) best predict the need for periodontal treatment.

Methods: Using detailed periodontal data obtained through clinical examination from the National Health and Nutrition Examination Survey 1999 to 2002, weighted logistic regression was used to model the periodontal treatment need of 15 different periodontal disease measures. The outcome measure is the clinically determined periodontal need.

Results: After adjustment for the covariates of age, sex, ethnicity, education, smoking status, and diabetes, the three most predictive measures were identified as: 1) the sum of the maximum mid‐buccal (B) and mesio‐buccal (MB) measures, which reflects the worst case of both B and MB measures; 2) the sum of the maximum MB measure or the worst case of the MB measure; and 3) the sum of all B and MB measures, or the cumulative AL measures.

Conclusions: Cumulative periodontal morbidity, particularly the worst case of B and MB measures, has the strongest impact on the need for periodontal care. All the demographic variables and covariates follow the classic pattern of association with periodontal disease.
A Synthetic Oligopeptide Derived From Enamel Matrix Derivative Promotes the Differentiation of Human Periodontal Ligament Stem Cells Into Osteoblast‐Like Cells With Increased Mineralization
Authors: Kato Hirohito , Katayama Nobuhito , Taguchi Yoichiro , Tominaga Kazuya , Umeda Makoto , Tanaka Akio
Published: November 2012

Background: In a previous study, the authors obtained a synthetic peptide (SP) for useful periodontal tissue regeneration. Periodontal ligament stem cells (PDLSCs) have multiple potentiality to contribute to tissue regeneration. The aim of this experiment is to investigate the effect of SP on human PDLSCs.

Methods: Periodontal ligament cells were obtained from healthy adult human third molars and used to isolate single PDLSC‐derived colonies. The mesenchymal stem cell nature of the PDLSCs was confirmed by immunohistochemical evaluation of STRO‐1 expression. Proliferation and osteoblastic differentiation were investigated by culturing PDLSCs in normal or osteogenic medium with and without SP (100 ng/mL). Osteoblast differentiation was assessed by measuring alkaline phosphatase (ALP) activity, osteocalcin production, mRNA expression of osteonectin, mineralization, and calcium deposition.

Results: Isolated PDLSCs were immunohistochemically positive for vimentin and STRO‐1 and negative for cytokeratin. A greater number of calcified nodules were observed in osteogenic medium culture with SP than without. In the early and later stages of PDLSC culture with SP, osteonectin production and osteocalcin production were increased. SP in culture with osteogenic medium significantly enhanced proliferation of PDLSCs, as well as ALP activity, expression of osteonectin, osteocalcin production, formation of calcified nodules, and mineralization.

Conclusions: SP enhances the formation of calcified nodules and osteocalcin production in the culture of PDLSCs into osteoblast‐like cells and is a useful material for periodontal tissue regeneration.
Host Genome, Epigenome, and Oral Microbiome Interactions: Toward Personalized Periodontal Therapy
Authors: Razzouk Sleiman , Termechi Omid
Published: November 2012

Periodontal diseases are multidimensional and complex. Bacterial content is the initiator, but disease progression depends on genetic and environmental parameters related to the host. Although bone loss magnitude is the common resulting outcome, the biologic process likely represents a unique inflammatory response characteristic to every individual. Therefore, it is obvious that practitioners must take into account the influence of these parameters and tailor a treatment accordingly. New, emerging deoxyribonucleotide‐based technologies allow integration of the biologic impact of the environment, and periodontists should be prepared to incorporate these technologies into their practice to advance personalized medicine. This commentary provides updated insights on the distinctiveness of inflammation per individual in terms of microbiome and genome specificity and cites some educational resources helpful for implementing individualized therapy.
Systems Cancer Biology and the Controlling Mechanisms for the J-Shaped Cancer dose Response: Towards Relaxing the LNT Hypothesis
Authors: Lou In Chio , Zhao Yuchao , Wu Yingjie , Ricci Paolo F
Published: November 2012

The hormesis phenomena or J-shaped dose response have been accepted as a common phenomenon regardless of the involved biological model, endpoint measured and chemical class/physical stressor. This paper first introduced a mathematical dose response model based on systems biology approach. It links molecular-level cell cycle checkpoint control information to clonal growth cancer model to predict the possible shapes of the dose response curves of Ionizing Radiation (IR) induced tumor transformation frequency. J-shaped dose response curves have been captured with consideration of cell cycle checkpoint control mechanisms. The simulation results indicate the shape of the dose response curve relates to the behavior of the saddle-node points of the model in the bifurcation diagram. A simplified version of the model in previous work of the authors was used mathematically to analyze behaviors relating to the saddle-node points for the J-shaped dose response curve. It indicates that low-linear energy transfer (LET) is more likely to have a J-shaped dose response curve. This result emphasizes the significance of systems biology approach, which encourages collaboration of multidiscipline of biologists, toxicologists and mathematicians, to illustrate complex cancer-related events, and confirm the biphasic dose-response at low doses.
What do researchers say about proposed Medicare claims public use files?
Authors: Erdem Erkan , Concannon Thomas W
Published: November 2012

Background:
Medicare claims data sets have been used widely in outcomes research over the last decade. In 2010, the Centers for Medicare & Medicaid Services established a program to create de-identified basic standalone public use files (PUFs) from Medicare claims data, each one containing claims information from a 5% sample of beneficiaries.
Methods:
We conducted a series of structured key informant interviews with research stakeholders to compile recommendations that would guide the creation of these PUFs. In this paper, we describe the interview methodology and present our findings. Fifteen researchers, representing a range of clinical health services and health policy expertise, were interviewed.
Results:
All respondents supported the use of Medicare claims in comparative effectiveness research and responded favorably to the creation of PUFs for this purpose. The interviews resulted in administrative-, technical- and content-related recommendations, some of which led to important changes in the PUFs.
Discussion:
A primary trade-off in the development of the proposed PUFs involved assuring maximum research utility of the files while assuring security of beneficiaries’ protected health information. Protection of protected health information was considered a requirement. Given this constraint, the proposed PUFs may be most useful for two primary activities in comparative effectiveness research: first, working through the beginning stages of a research project; and second, examining high-level questions.
Comparing methods of respiratory event detection during the treatment of obstructive sleep apnea
Authors: Fields Barry G , Kuna Samuel T
Published: November 2012

Renewed focus on comparative effectiveness research presents a unique opportunity to develop optimal clinical management pathways for patients with obstructive sleep apnea. With this momentum comes the challenge of measuring treatment effect on sleep-disordered breathing, especially in large, multisite studies. In-laboratory polysomnography, the current gold standard sleep assessment of obstructive sleep apnea severity, is costly and imposes significant participant burden. Alternatives include home unattended sleep testing and overnight pulse oximetry recording. Research studies using positive airway pressure treatment have the additional option of using the information recorded by the patient’s positive airway pressure device to assess treatment effectiveness. Recent research has shown relatively good agreement between manual identification of residual respiratory events in overnight in-laboratory polysomnography and the automatic event detection utilized in positive airway pressure machines. In addition to assessing the effects of interventions on sleep disordered breathing, obstructive sleep apnea-related comparative effectiveness studies need to assess the impact of the interventions on patient burden, cost of therapy, timeliness of care, improved quality of life and other clinically relevant outcomes.
Drug-eluting versus bare-metal coronary stents: where are we now?
Authors: Amoroso Nicholas S , Bangalore Sripal
Published: November 2012

Drug-eluting stents have dramatically reduced the risk of restenosis, but concerns of an increased risk of stent thrombosis have provided uncertainty about their use. Recent studies have continued to show improved procedural and clinical outcomes with drug-eluting stents both in the setting of acute coronary syndromes and stable coronary artery disease. Newer generation drug-eluting stents (especially everolimus-eluting stents) have been shown to be not only efficacious but also safe with reduced risk of stent thrombosis when compared with bare-metal stents, potentially changing the benchmark for stent safety from bare-metal stents to everolimus-eluting stents. While much progress is being made in the development of bioabsorbable polymer stents, nonpolymer stents and bioabsorbable stent technology, it remains to be seen whether these stents will have superior safety and efficacy outcomes compared with the already much improved rates of revascularization and stent thrombosis seen with newer generation stents (everolimus-eluting stents and resolute zotarolimus-eluting stents).
Calculation of body surface area via computed tomography–guided modeling in domestic rabbits (Oryctolagus cuniculus)
Authors: Zehnder Ashley M. , Hawkins Michelle G. , Trestrail Earl A. , Holt Randall W. , Kent Michael S.
Published: November 2012

Objective—To optimize the use of CT-guided modeling for the calculation of body surface area (BSA) in domestic rabbits (Oryctolagus cuniculus).

Animals—12 domestic rabbits.

Procedures—Adult rabbits (body weight, 1 to > 4 kg) that were client-owned animals undergoing CT for disease diagnosis or deceased laboratory animals donated from other research projects were scanned with a CT scanner. Images were transferred to a radiation therapy planning software program. Image slices were captured as contiguous slices at 100 kVp and 100 mA and processed to 0.1-cm-thick sections. The length of each contoured slice was summed to calculate a final BSA measurement. Nonlinear regression analysis was then used to derive an equation for the calculation of BSA in rabbits.

Results—The constant calculated by use of this method was 9.9 (range, 9.59 to 10). The R2 for the goodness of fit was 0.9332. The equation that best described BSA as a function of body weight for domestic rabbits with this method was as follows: BSA = (9.9 × [body weight {in grams}]2/3)/10,000.

Conclusions and Clinical Relevance—The BSA calculated via the CT-guided method yielded results similar to those obtained with equations for other similarly sized mammals and verified the use of such equations for rabbits. Additionally, this technique can be used for species that lack equations for the accurate calculation of BSA.
Evaluation of squeeze-induced somnolence in neonatal foals
Authors: Toth Balazs , Aleman Monica , Brosnan Robert J. , Dickinson Peter J. , Conley Alan J. , Stanley Scott D. , Nogradi Nora , Williams Colette D. , Madigan John E.
Published: November 2012

Objective—To test the hypothesis that application of a rope restraint device would result in behavioral, electroencephalographic, and humoral changes consistent with sleep and analgesia in neonatal foals.

Animals—8 healthy neonatal foals.

Procedures—Following acclimatization to experimental conditions, each foal underwent a series of assessments before and during or at the end of a period of restraint via application of a restraint device (soft linen rope). Assessments included measurements of heart and respiratory rates, rectal temperature, and circulating β-endorphin and steroid hormone concentrations and evaluations of mentation and body position (behavior), electroencephalographic patterns, and pain tolerance.

Results—All foals were lively with apparently normal behavior prior to restraint. During application of the restraint device, foals assumed lateral recumbency with relaxed, somnolent behavior. Heart and respiratory rates and rectal temperature uniformly decreased as a result of the procedure. Electroencephalographic recordings (completed for 3 foals only) revealed patterns consistent with slow wave sleep. Plasma ACTH, dehydroepiandrosterone sulfate, and androstenedione concentrations significantly increased during restraint, compared with prerestraint values. The foals' tolerance to noxious stimuli significantly increased during restraint; however, this was independent of the concentration of circulating β-endorphin.

Conclusions and Clinical Relevance—In neonatal foals, the evaluated form of restraint resulted in a decrease in heart and respiratory rates and rectal temperature. Squeeze-induced somnolence may resemble the effects of compression of the fetus in the birth canal and lead to inhibition of voluntary activity. Use of this technique to safely restrain neonatal foals during minor procedures warrants further evaluation.
Evaluation of four methods used to measure plasma insulin-like growth factor 1 concentrations in healthy cats and cats with diabetes mellitus or other diseases
Authors: Tschuor Flurin , Zini Eric , Schellenberg Stefan , Wenger Monique , Boretti Felicitas S. , Reusch Claudia E.
Published: November 2012

Objective—To evaluate 4 methods used to measure plasma insulin-like growth factor (IGF) 1 concentrations in healthy cats and cats with diabetes mellitus or other diseases.

Animals—39 healthy cats, 7 cats with diabetes mellitus, and 33 cats with other diseases.

Procedures—4 assays preceded by different sample preparation methods were evaluated, including acid chromatography followed by radioimmunoassay (AC-RIA), acid-ethanol extraction followed by immunoradiometry assay (AEE-IRMA), acidification followed by immunochemiluminescence assay (A-ICMA), and IGF-2 excess followed by RIA (IE-RIA). Validation of the methods included determination of precision, accuracy, and recovery. The concentration of IGF-1 was measured with all methods, and results were compared among cat groups.

Results—The intra-assay coefficient of variation was < 10% for AC-RIA, A-ICMA, and AEE-IRMA and 14% to 22% for IE-RIA. The linearity of dilution was close to 1 for each method. Recovery rates ranged from 69% to 119%. Five healthy cats had IGF-1 concentrations > 1,000 ng/mLwith the AEE-IRMA, but < 1,000 ng/mL with the other methods. Compared with healthy cats, hyperthyroid cats had significantly higher concentrations of IGF-1 with the A-ICMA method, but lower concentrations with the IE-RIA method. Cats with lymphoma had lower IGF-1 concentrations than did healthy cats regardless of the method used.

Conclusions and Clinical Relevance—Differences in the methodologies of assays for IGF-1 may explain, at least in part, the conflicting results previously reported in diabetic cats. Disorders such as hyperthyroidism and lymphoma affected IGF-1 concentrations, making interpretation of results more difficult if these conditions are present in cats with diabetes mellitus.