bluuebunny/crossref_metadata_2025 huggingface dataset:
Residents’ knowledge of quality improvement: the impact of using a group project curriculum
Authors: Duello Katherine , Louh Irene , Greig Hope , Dawson Nancy
Published: August 2015

Background

The Accreditation Council for Graduate Medical Education requires residents to learn and demonstrate proficiency in practice improvement. Quality improvement (QI) projects are a way to improve patient care as well as facilitate education on this core competency. There are inherent barriers to completing these goals in the structure of residency training including rigorous resident schedules and a limited number of projects and resources.

Objectives

We developed a QI programme using an experiential class project and incorporated it into our Internal Medicine Resident Core Curriculum to improve the residents’ knowledge of QI methods. We assessed the residents’ experience, knowledge and interest in practice and QI subject matter with a survey preimplementation and postimplementation.

Methods

In 2009, 24 residents in the Internal Medicine resident programme completed a survey measuring their experience, knowledge and interest in QI initiatives. They then completed a QI 1-year programme, with monthly, 1-hour sessions combining didactics and a resident-designed project. At the conclusion of the year, the residents completed the same survey, and the results were compared and analysed.

Results

Postcurriculum questionnaires revealed residents were more knowledgeable about QI methods, showing improvement in knowledge about institutional-wide QI projects, better preparation for implementing a QI project, and more likely to participate in QI in the future. The project completed was one which improved patients’ knowledge of their anticipated date of discharge from the hospital.

Conclusions

A class quality project can teach QI to residents incorporating both didactic and practical methods to maximise the experience and minimise the barriers. We found that this method improved residents experience, knowledge and interest in quality initiatives.
Development of the Biostatistics and Clinical Epidemiology Skills (BACES) assessment for medical residents
Authors: Barlow Patrick B , Skolits Gary , Heidel Robert Eric , Metheny William , Smith Tiffany Lee
Published: August 2015

Background

Although biostatistics and clinical epidemiology are essential for comprehending medical evidence, research has shown consistently low and variable knowledge among postgraduate medical trainees. Simultaneously, there has been an increase in the complexity of statistical methods among top-tier medical journals.

Aims

To develop the Biostatics and Clinical Epidemiology Skills (BACES) assessment by (1) establishing content validity evidence of the BACES; (2) examining the model fit of the BACES items to an Item Response Theory (IRT) model; and (3) comparing IRT item estimates with those of traditional Classical Test Theory (CTT) indices.

Methods

Thirty multiple choice questions were written to focus on interpreting clinical epidemiological and statistical methods. Content validity was assessed through a four-person expert review. The instrument was administered to 150 residents across three academic medical centres in southern USA during the autumn of 2013. Data were fit to a two-parameter logistic IRT model and the item difficulty, discrimination and examinee ability values were compared with traditional CTT item statistics.

Results

147 assessments were used for analysis (mean (SD) score 14.38 (3.38)). Twenty-six items, 13 devoted to statistics and 13 to clinical epidemiology, successfully fit a two-parameter logistic IRT model. These estimates also significantly correlated with their comparable CTT values.

Conclusions

The strength of the BACES instrument was supported by (1) establishing content validity evidence; (2) fitting a sample of 147 residents’ responses to an IRT model; and (3) correlating the IRT estimates with their CTT values, which makes it a flexible yet rigorous instrument for measuring biostatistical and clinical epidemiological knowledge.
Barriers to healthcare seeking among medical students: a cross sectional study from South India
Authors: Menon Vikas , Sarkar Siddharth , Kumar Santosh
Published: August 2015

Objective

To determine the barriers to seeking help from healthcare services reported by medical students at an Indian medical school, and to compare the barriers for using physical health services with those for using mental health services.

Methods

In 2014, we invited all medical students across the nine semesters of training at a government medical college in Puducherry, India, to complete a 28 item questionnaire about perceived barriers to seeking healthcare services. The questionnaire enquired about barriers to using physical and mental healthcare services separately.

Results

Completed responses were available from 461 of 509 students (response rate 90.6%). Stigma, confidentiality issues, lack of awareness about where to seek help and fear of unwanted intervention were more commonly reported for mental healthcare seeking (OR 4.21, 4.01, 3.19 and 2.43, respectively), while issues relating to cost, lack of time and fear of side effects were observed less frequently (OR 0.45, 0.46 and 0.57, respectively) compared with physical healthcare seeking. In comparison with physical health, students were more indifferent to their mental health issues and preferred self-diagnosis and informal consultations over formal documented care.

Conclusions

Barriers to seeking healthcare services differ for mental and physical health issues. Many system based barriers such as stigma, confidentiality issues and poor awareness of service location were reported by students. Institutional programmes should use this information for improving the usage, satisfaction and effectiveness of healthcare delivery systems for medical students.
Influence of species identity and charring conditions on fire-derived charcoal traits
Authors: Pluchon Nathalie , Casetou Sophie C. , Kardol Paul , Gundale Michael J. , Nilsson Marie-Charlotte , Wardle David A.
Published: August 2015

Fire is a major disturbance worldwide, and it produces significant amounts of wood-derived charcoal. There is increasing evidence that the key properties (“traits”) of charcoal vary greatly, with consequences for ecosystem processes, but how the key factors drive variability of charcoal traits, i.e., species identity and charring conditions, remain poorly understood. Here, we experimentally produced charcoal from three common boreal tree species under six charring conditions representing those encountered during boreal fires and then analyzed their structural and chemical traits. Overall, we found that species identity affected charcoal traits more than did charring conditions. Among the structural traits, density and microporosity varied among tree species, and density decreased with increasing temperature. Among the chemical traits, electrical conductivity, total nitrogen (N) and phosphorus (P) contents, and phosphate concentration differed among species, whereas pH, total N content, and ammonium concentration responded to charring conditions. No traits except nitrate concentration responded to the interactive effect of species identity and charring condition. Our results reveal that traits of charcoal, and potentially its ecological functions, are driven by a combination of fire behavior and tree species identity; such information is relevant for understanding ecological consequences of altered fire regimes due to the changing climate and to forest management.
AICAR enhances insulin signaling via downregulation of miR-29
Authors: Liu Jia , Ye Cheng , Liu Wei , Zhao Wei , Zhang Ya-jing , Zhang Hong , Ying Hao
Published: August 2015

As an activator of AMPK, the effect of AICAR on insulin signaling has not been investigated extensively. PI3K–Akt is a critical node involved in the insulin signaling pathway. We observed that concomitant with the activation of AMPK by AICAR, the protein level of PI3K p85α and the insulin-induced phosphorylation of Akt were enhanced in mouse primary hepatocytes. Previously, we identified a group of AMPK-regulated miRNAs in hepatocytes. It is not clear whether miRNAs are related to the regulation of insulin signaling by AMPK. Here, we confirmed the negative regulation of miR-29 family members by AICAR treatment in mouse primary hepatocytes. Our results indicated that p85α is a direct target of miR-29 and is negatively regulated by miR-29b in hepatocytes. In agreement with the findings in vitro, we found that the expression of miR-29 and the protein levels of p85α were inversely correlated in the liver of fasted mice. Overexpression of miR-29b reduced the insulin-induced phosphorylation of Akt in hepatocytes, suggesting that miR-29 could serve as a negative regulator of insulin signaling. Furthermore, we found that overexpression of miR-29 could attenuate the effect of AICAR on p85α expression. Taken together, our results indicated that activation of AMPK may enhance insulin signaling via downregulation of miR-29.
How Elections are Impacted by Production, Economic Growth and Conflict
Authors: Hausken Kjell , Ncube Mthuli
Published: August 2015

We analyze the pre- and post-election processes as a two-period game between an incumbent and a challenger. Before the election, in period 1, an incumbent allocates resources into production, fighting with the challenger, and providing public goods, which impact the probability of winning an election. After the election, in period 2 the incumbent may accept the election result, or a coalition or standoff may follow. Six outcomes are that the incumbent wins, the challenger wins, and that a standoff or coalition arises after one of the players wins. We analyze the incumbent’s and challenger’s strategic choices, how these choices depend on a variety of parameters, and the impact of the choices. The analysis is mapped to and tested against empirics of 48 African elections during 2009–2015 which are classified into the six outcomes. To test the model empirically, the correlations between three variables (the incumbent’s fighting and public goods provision and the challenger’s fighting, in period 1) and the six election outcomes are determined for 48 African elections.
An Exploration with Novel Shape Signature of GMSC Distance Function to Track the Object
Authors: Sidram M. H. , Bhajantri Nagappa U.
Published: August 2015

The process explicitly dedicated to estimate the path of the object as it moves along the region of scene in the image plane is the principle of tracking. In other words, it is a strategy to detect and track moving object through a sequence of frames. In this work, optical flow based on Horn–Schunk with Barren, Fleet and Beuchemin (BFB) kernel has been employed to estimate the motion vectors.

The peripheries of moving objects are extracted for different shape signatures such as boundary, edge, area, curvature and centroid distance functions. Fourier descriptors (FD) of particular shape signature for each of the candidate templates and model template are computed. Similarity between the model template and candidate templates is confirmed by corresponding minimum Minkowski distance (MD). Subsequently, best match candidate template will be updated by model template in view of tracking process.

However, centroid distance function has remarked some potentials and hence it has further motivated to mine it to throw in the proposed novel criteria such as the geometric mean of segmented centroid (GMSC) distance function to track the object. The proposed method of GMSC distance function has shown significant change in the tracking outcome.
Radical of perfect numbers and perfect numbers among polynomial values
Authors: Klurman Oleksiy
Published: August 2015

It is conjectured that [Formula: see text] for any perfect number [Formula: see text]. We prove that [Formula: see text] improving the previous bound of Luca and Pomerance as well as Acquaah and Konyagin. As a consequence, we prove that assuming the [Formula: see text]-conjecture, any integer polynomial of degree [Formula: see text] without repeated factors can take only finitely many perfect values. We also show that the latter holds unconditionally for even perfect numbers.
Influence of the Spin–Orbit Interaction on the Magnetotransport Properties of a Two-Dimensional Electron System
Authors: Cangas R. , Hidalgo M. A.
Published: August 2015

In this paper, we review the contribution of the Rashba spin–orbit coupling to the magnetoconduction of a two-dimensional electron system (2DES) confined in an inversion layer under quantum Hall regime (low temperature and low defects and impurities). The study is based on a semi-classical model for the magnetoconductivities of the 2DES. This model reproduces the measurements of the Shubnikov-de Haas (SdH) oscillations obtained in systems confined in III–V heterostructures, and also the quantum Hall magnetoconductivity (magnetoresistivity). We also discuss the Rashba and Zeeman competition and its effect on the magnetoconductivity.
Tuning Effects of Spin–Orbit Coupling in L10Ordered and Disordered FePdPt Films
Authors: Fan W. J. , Shi Z. , Chen F. L. , Zhou S. M.
Published: August 2015

Effects of spin–orbit coupling (SOC) on magnetocrystalline anisotropy, magneto-optical Kerr effect (MOKE), magnetic damping parameter and anomalous Hall effect (AHE) have been studied in theory extensively. In contrast, few experimental reports have appeared on these issues. In this review paper, we introduce our recent experimental investigation on the SOC tuning effects on the perpendicular magnetic anisotropy, polar MOKE, intrinsic magnetic damping parameter and AHE in L10ordered [Formula: see text] ternary alloys. We also outline the SOC effects in polycrystalline disordered [Formula: see text] films for comparison.
An Accommodative Security Architecture in the Asia-Pacific
Authors: Wu Chunsi
Published: August 2015

In the Asia-Pacific geopolitical dynamics, China's rise and its accompanying "assertive" diplomacy are often cited by some studies as the cause of security concerns. The author argues that this interpretation of the Asia-Pacific security situation is wrong. The Asia-Pacific confronts various and complex security problems, which cannot be simply attributed to the rise of China. The occurrence and activation of so many security problems in the Asia-Pacific only indicate that the security architecture in the region is undergoing a profound transition. The old security architecture inherited from the Cold War era cannot effectively handle the security problems in the region any more. The Asia-Pacific needs a new architecture adaptive to the features of the post-Cold War era. The new security architecture should embody the spirit of cooperation and reflect Asian countries' interests and ways of handling regional affairs. More importantly, the new security architecture should feature ample accommodativeness, not only including the diverse cultures and paths of development of the region, but also encouraging and incentivizing all parties of the region to learn from each other so as to JNTly create a sustainable security environment for the region.
The Ecological and Evolutionary Consequences of Marine Reserves
Authors: Baskett Marissa L. , Barnett Lewis A.K.
Published: August 2015

Here we review the population, community, and evolutionary consequences of marine reserves. Responses at each level depend on the tendency of fisheries to target larger body sizes and the tendency for greater reserve protection with less movement within and across populations. The primary population response to reserves is survival to greater ages and sizes plus increases in the population size for harvested species, with greater response to reserves that are large relative to species' movement rates. The primary community response to reserves is an increase in total biomass and diversity, with the potential for trophic cascades and altered spatial patterning of metacommunities. The primary evolutionary response to reserves is increased genetic diversity, with the theoretical potential for protection against fisheries-induced evolution and selection for reduced movement. The potential for the combined outcome of these responses to buffer marine populations and communities against temporal environmental heterogeneity has preliminary theoretical and empirical support.
Surveying Key Aspects of Sociolegal Scholarship on India: An Overview
Authors: Krishnan Jayanth K. , Thomas Patrick W.
Published: August 2015

This article surveys key aspects of sociolegal scholarship on India. The literature has tended to emphasize certain areas, such as rights-based social movements, courts (both formal and informal), and the legal profession. Additionally, various authors over the years have examined gender, religion, and caste—each on its own, but also how each can intersect with one another and with the other above-mentioned topics. And more recently, there has been a burgeoning sociolegal literature on the role globalization plays in India. Scholars who have written on these issues approach their work from a range of methodological perspectives, but regardless, as we argue here, much of this literature has served as a vehicle to champion the rights of the needy. Gaps, of course, still are present, which we discuss. We conclude by highlighting a few areas upon which scholars may wish to build in the future.
Improving the Effectiveness of Suspect Interrogations
Authors: Meissner Christian A. , Kelly Christopher E. , Woestehoff Skye A.
Published: August 2015

The past two decades of research on interrogation were spurred, in large part, by the specter of false confessions and the resulting miscarriages of justice. More recently, interest in the topic has been fueled by the need to develop evidence-based methods that improve the collection of diagnostic confession evidence and accurate intelligence from human sources. In this review, we update the research on false confessions and describe recent assessments of scientifically validated approaches for obtaining cooperation, eliciting confessions, and detecting deceit. Studies are summarized through the prism of accusatorial versus information-gathering approaches to interrogation: The former rely on psychological manipulation and control-based methods, whereas the latter focus on developing rapport and cooperation to elicit an account that can be strategically addressed via evidence presentation. The review concludes with recommendations for additional research to further improve the effectiveness of interrogations across a variety of contexts.
Visualizing and Quantifying Oceanic Motion
Authors: Rossby T.
Published: August 2015

Here I review the use of two highly complementary acoustical technologies for measuring currents in the ocean: acoustically tracked neutrally buoyant floats and vessel-mounted acoustic Doppler current profilers (ADCPs). The beauty of floats lies in their ability to efficiently and accurately visualize fluid motion in fronts and vortices and the dispersion caused by mesoscale eddy processes. Floats complement classical hydrography by articulating mechanisms and pathways by which waters spread out from their source region. Vessel-mounted ADCPs can profile the water column at O(1 km) horizontal resolution to depths greater than 1,000 m. These vessel-based scans capture in detail the cross-stream structure of fronts and eddies as well as the impact of bathymetry on currents. Sustained sampling along selected routes builds up valuable databases both for statistical studies of the submesoscale velocity field and for accurate estimates of fluid transport, as well as how these vary over time.
New Approaches to Marine Conservation Through the Scaling Up of Ecological Data
Authors: Edgar Graham J. , Bates Amanda E. , Bird Tomas J. , Jones Alun H. , Kininmonth Stuart , Stuart-Smith Rick D. , Webb Thomas J.
Published: August 2015

In an era of rapid global change, conservation managers urgently need improved tools to track and counter declining ecosystem conditions. This need is particularly acute in the marine realm, where threats are out of sight, inadequately mapped, cumulative, and often poorly understood, thereby generating impacts that are inefficiently managed. Recent advances in macroecology, statistical analysis, and the compilation of global data will play a central role in improving conservation outcomes, provided that global, regional, and local data streams can be integrated to produce locally relevant and interpretable outputs. Progress will be assisted by (a) expanded rollout of systematic surveys that quantify species patterns, including some carried out with help from citizen scientists; (b) coordinated experimental research networks that utilize large-scale manipulations to identify mechanisms underlying these patterns; (c) improved understanding of consequences of threats through the application of recently developed statistical techniques to analyze global species' distributional data and associated environmental and socioeconomic factors; (d) development of reliable ecological indicators for accurate and comprehensible tracking of threats; and (e) improved data-handling and communication tools.
Radiative Capture Reactions in Astrophysics
Authors: Brune Carl R. , Davids Barry
Published: August 2015

The radiative capture reactions of greatest importance in nuclear astrophysics are identified and placed in their stellar contexts. Recent experimental efforts to estimate their thermally averaged rates are surveyed.
Experimental Searches for the Axion and Axion-Like Particles
Authors: Graham Peter W. , Irastorza Igor G. , Lamoreaux Steven K. , Lindner Axel , van Bibber Karl A.
Published: August 2015

Four decades after its prediction, the axion remains the most compelling solution to the strong-CP problem and a well-motivated dark matter candidate, inspiring a host of elegant and ultrasensitive experiments based on axion–photon mixing. This article reviews the experimental situation on several fronts. The microwave cavity experiment is making excellent progress in the search for dark matter axions in the μeV range and may plausibly be extended up to 100 μeV. Within the past several years, however, researchers have realized that axions are pervasive throughout string theories, but with masses that fall naturally in the neV range, for which an NMR-based search is under development. Both searches for axions emitted from the Sun's burning core and purely laboratory experiments based on photon regeneration have recently made great progress, with ambitious projects proposed for the coming decade. Each of these campaigns has pushed the state of the art in technology, enabling large gains in sensitivity and mass reach. Furthermore, each modality has been exploited in order to search for more generalized axion-like particles, which we also discuss in this review. We are hopeful, even optimistic, that the next review of the subject will concern the discovery of the axion, its properties, and its exploitation as a probe of early universe cosmology and structure formation.
Changing Norms to Change Behavior
Authors: Miller Dale T. , Prentice Deborah A.
Published: August 2015

Providing people with information about the behavior and attitudes of their peers is a strategy commonly employed by those seeking to reduce behavior deemed harmful either to individuals (e.g., high alcohol consumption) or the collective (e.g., high energy consumption). We review norm-based interventions, detailing the logic behind them and the various forms they can take. We give special attention to interventions designed to decrease college students' drinking and increase environment-friendly behaviors. We identify the conditions under which norm information has the highest likelihood of changing the targeted behavior and discuss why this is the case.
Drug Addiction: Updating Actions to Habits to Compulsions Ten Years On
Authors: Everitt Barry J. , Robbins Trevor W.
Published: August 2015

A decade ago, we hypothesized that drug addiction can be viewed as a transition from voluntary, recreational drug use to compulsive drug-seeking habits, neurally underpinned by a transition from prefrontal cortical to striatal control over drug seeking and taking as well as a progression from the ventral to the dorsal striatum. Here, in the light of burgeoning, supportive evidence, we reconsider and elaborate this hypothesis, in particular the refinements in our understanding of ventral and dorsal striatal mechanisms underlying goal-directed and habitual drug seeking, the influence of drug-associated Pavlovian-conditioned stimuli on drug seeking and relapse, and evidence for impairments in top-down prefrontal cortical inhibitory control over this behavior. We further review animal and human studies that have begun to define etiological factors and individual differences in the propensity to become addicted to drugs, leading to the description of addiction endophenotypes, especially for cocaine addiction. We consider the prospect of novel treatments for addiction that promote abstinence from and relapse to drug use.
Coronavirus Host Range Expansion and Middle East Respiratory Syndrome Coronavirus Emergence: Biochemical Mechanisms and Evolutionary Perspectives
Authors: Peck Kayla M. , Burch Christina L. , Heise Mark T. , Baric Ralph S.
Published: August 2015

Coronaviruses have frequently expanded their host range in recent history, with two events resulting in severe disease outbreaks in human populations. Severe acute respiratory syndrome coronavirus (SARS-CoV) emerged in 2003 in Southeast Asia and rapidly spread around the world before it was controlled by public health intervention strategies. The 2012 Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak represents another prime example of virus emergence from a zoonotic reservoir. Here, we review the current knowledge of coronavirus cross-species transmission, with particular focus on MERS-CoV. MERS-CoV is still circulating in the human population, and the mechanisms governing its cross-species transmission have been only partially elucidated, highlighting a need for further investigation. We discuss biochemical determinants mediating MERS-CoV host cell permissivity, including virus spike interactions with the MERS-CoV cell surface receptor dipeptidyl peptidase 4 (DPP4), and evolutionary mechanisms that may facilitate host range expansion, including recombination, mutator alleles, and mutational robustness. Understanding these mechanisms can help us better recognize the threat of emergence for currently circulating zoonotic strains.
Multi-Physics Modeling of a Na-NiCl2 Commercial Cell
Authors: Christin Rémy , Cugnet Mikaël , Zanon Nicola , Crugnola Giorgio , Mailley Pascal
Published: August 2015

A two-dimensional multi-physics model of a Na-NiCl2 commercial cell is presented. Thermodynamics, electrode kinetics, transport phenomena, and thermal effects are involved in a system of non-linear partial differential equations. This work sheds new light on mathematical modeling of sodium metal halide cell. Some novel hypotheses are used to simulate the cell dynamic behavior during discharges at various rates and initial temperatures. Implementation and computations are performed with Comsol Multiphysics, and the model performance is validated with experimental data obtained from the FIAMM commercial cell.
Anode Based on Porous Silicon Films Using Polymer Electrolyte for Lithium-Ion Microbatteries
Authors: Chaudoy V. , Luais Erwann , Ghamouss F. , Defforge Thomas , Desplobain S. , Gautier G. , Wolfman J. , Houdbert J.-C. , Tran-Van François , Sakai J.
Published: August 2015

In this paper, the preparation of an all solid-state lithium-ion microbattery is presented with original core materials : a gel polymer electrolyte (GPE) and a macroporous silicon (pSi) as the anode. The preparation and the synthesis of GPE consist of solubilizing a linear polymer (PVdF-HFP : poly(vinylidene fluoride-co-hexafluoropropylene) with an ionic liquid (P13FSI : Pyrrolidinium bis(fluorosulfonyl)imide) and a lithium salt (LiTFSI : lithium bis-trifluoromethanesulfonimide). The polymer film is transparent, self-supported and presents an ionic conductivity of 1.88 mS.cm-2 at 25°C. GPE compatibility with a Li/LiCoO2 system, with a Li/pSi half-cell and finally with a pSi/LiCoO2 lithium-ion microbattery, is demonstrated through 30 galvanostatic cycles. The full cell reaches a discharge capacity of 173 µAh/cm2 at 167 µA/cm2 with a coulombic efficiency upper than 99 % after 7 cycles of charge and discharge.
Two Pathways for Near Room Temperature Electrochemical Conversion of Methane to Methanol
Authors: Omasta Travis J , Rigdon William A , Lewis Connor A , Stanis Ronald J , Liu Renxuan , Fan Chinbay Q , Mustain William E
Published: August 2015

The conversion of methane to methanol in low temperature alkaline flow cells is studied. The mechanism of oxygen insertion without breaking the C-H bond for methane activation is examined with both hydroxide and carbonate oxygen donors. The effectiveness of adding zirconium oxide to the nickel oxide catalyst to facilitate carbonate adsorption is evaluated. Methanol production in the flow cells is measured using multiple techniques.
Modeling of Proton Conductivity through Perfluorosulfonate Acid Electrolyte Membranes
Authors: Zhang Bo , Edwards Brian Joseph
Published: August 2015

Proton conductivity through perfluorosulfonate acid (PFSA) polymer electrolyte membranes was investigated using a nanoporous network model to describe transport of charged species through PFSA membranes. The membrane was modeled as an indeterminate network of random fractal nanopores with the PFSA anionic groups fixed along the pore wall according to a distribution determined by the equivalent weight and dry membrane density. The transport of the hydronium ions inside the pore was expressed using the Nernst-Einstein equation. Continuum percolation theory and a fractal structural model were used to determine a relevant diffusion coefficient and to illustrate the possible transport mechanisms. The conductivity of the membrane was deduced in terms of the following quantities: water content, equivalent weight, temperature, and the architecture of PFSA polymer. Theoretical predictions of the model for varying water content and temperature were compared against experimental conductivity data of four commercial PFSA membranes.
Study on Degradation and Failure in Lithographically Patterned Gold/Manganese Dioxide Core/Shell Nanowires Based Supercapacitors
Authors: Thesma Chandran Girija , Le Thai Mya , Penner R. M.
Published: August 2015

Nanosized manganese oxide (MnO2) is a widely studied material for electrochemical capacitors because of the high specific surface area and excellent electrochemical properties leading to improved rate capability and enhanced energy/power densities. Most of the research on MnO2 is aimed at improving the capacitance whereas only a few studies are focused on cycling stability of these electrodes. In this work, degradation in capacitance of arrays of gold core nanowire encapsulated within a hemicylindrical shell of MnO2 is studied. Raman spectroscopy experiments performed on a single core/shell nanowire indicated changes in spectral shifts of the prominent Raman modes for δ-MnO2 as well as changes in the intensity of these modes.
Study on the Electrochemical Characteristics of Multiwalled CNTs Decorated by Various Oxygen Functional Groups (Non-Aqueous and Aqueous based Electrolytes)
Authors: Oktaviano Haryo Satriya , Wajima Mikiya , Waki Keiko
Published: August 2015

The electrochemical characteristic of different oxygen functional groups on MWCNTs was investigated in both non-aqueous and aqueous electrolyte. The removal of carboxyls from CNTs has affected the capacitive response in both electrolytes. This suggest that carboxyl groups play an important role to the electrochemical characteristics of functionalized CNTs
Sensitivity Analysis of an Electrochemical Model of Li-ion Batteries and Consequences on the Modeled Aging Mechanisms
Authors: Edouard Clément , Petit Martin , Bernard Julien , Forgez Christophe , Revel Renaud
Published: August 2015

A sensitivity analysis of a simplified electrochemical model was performed to find out the influence on the model output of the 37 physical parameters. The standard deviation of the simulated voltage after discharges at different temperatures and C-rates show that some parameters were more sensitive than others and needed more accurate identification or measurement to ensure the reliability of the model prediction. Moreover, processing of the sensitivity analysis results permitted to find out the conditions under which the parameters were the more sensitive. A step-wise identification strategy was then determined, to be able to identify the sensitive parameters of the model in a more accurate manner.
Study on the Preparation of the Cathode Materials for Lithium-Ion Batteries by Multiphase Redox Method
Authors: Xi Xiao-ming , Liao Da-qian , Hu Liu-quan , Huang Zhou-shu , Tang Mo-tang
Published: August 2015

We report a new method, which is called multiphase redox method, to prepare LiMn2O4 cathode material. The precursors of LiMn2O4 were synthetized in Mn(OH)2-H2O-LiOH solution system by using air, oxygen or KMnO4 as the oxidant. The oxidation ability of the oxidant has an important influence on the amount of lithium embedding. Meanwhile, the sintering process and the electrochemical performance of the sintered samples are studied as well. The sample sintered at 820℃ for 10 h presents both high discharge capacity and excellent cycle performance. Compared with LiMn2O4 prepared by solid-state method, the uniformity in chemical composition of LiMn2O4 prepared by multiphase redox method is bettered significantly and the differences in micro-components of LiMn2O4 are almost eliminated, thus improving the electrochemical performance of LiMn2O4 prepared by multiphase redox method.
Study on the Charging Behaviors of Lithium-Ion Batteries by Analysis of Li Distribution in the Electrode Particles
Authors: Yang Naixing , Zhang Xiongwen , Li Guojun , Hua Dong
Published: August 2015

The lithium-ion battery is considered to be one of the most attractive energy storage systems for electric vehicles (EVs), and the fast charging technology is a basic requirement for the popularity of EVs. This paper investigates the influences of the current and temperature on the charging behaviors based on the analysis of the Li concentration distributions inside the electrode particles. The constant current (CC)-constant voltage (CV) mode is adopted. The results show that the chargeable capacity in the CC stage decreases as the charging current increases from 0.5C to 4C, whereas it changes slightly as the current larger than 4C; the CC charging time is approximately inversely proportional to the charging current, whereas the CV charging time changes slightly as the charging current increases. For application of EVs, the battery is recommended to only charge 90% of the total capacity, which can greatly shorten the charging time.
The Relation between the Microstructure and Corrosion Behavior of Aluminum Alloy AA2024-T3
Authors: Yi Han Bang , Lin Chao-Sung
Published: August 2015

Two different acidic pretreatments were applied on aluminum alloy 2024-T3 before the trivalent chrome process (TCP). Micro-sized pits were observed on the alloy surface treated with Deoxidizer 6, which contained chromic acid and hydrofluoric acid, while the surface morphology hardly changed after nitric acid pretreatment. Moreover, a thin film containing Cr was formed on the surface after Deoxidizer 6 pretreatment. This passivation film deteriorated the reactivity during TCP. The TCP coating treated after nitric acid was thus thicker than that treated after Deoxidizer 6. The effect of immersion time of acidic pretreatment was examined using potentiodynamic polarization curve. It was found that increasing immersion time was not necessarily proportional to the anti-corrosion properties of TCP coatings.
Growth of TiO2 Nanotube Layers on Ti Substrates with Different Microstructures
Authors: Kim Min Su , Yamamoto Shota , Tsuchiya Hiroaki , Fujimoto Shinji
Published: August 2015

The present work examined the morphology of anodic oxide layers on Ti substrates with different microstructures. The microstructures were varied by the heat-treatment or accumulative roll-bonding (ARB) process. Tubular oxide layers were formed on all Ti substrates by anodization, but the thickness of the layers was changed. The thickness of oxide layer formed on heat-treated substrates decreased with increasing heat-treatment temperature and duration. On the other hand, ARB process resulted in the increase of the thickness. Therefore, the microstructures affected the growth of tubular anodic oxide layers.
A Cationic Contamination in PEFC Cathode: A Cause and Effect Study
Authors: Uddin Md. Aman , Park Jaehyung , Ganesan Selvarani , Pasaogullari Ugur , Bonville Leonard J. , Molter Trent
Published: August 2015

Cationic contamination in polymer electrolyte fuel cells (PEFC) is investigated by contaminating a catalyst coated membrane (CCM) in Ca2+ solution prior to a long term durability test. The cathode catalyst layer of the contaminated CCM becomes significantly thinner over the entire active area of the CCM as compared to an as-received, uncontaminated CCM. It is found that there is no change in the total Pt content in cathode catalyst layer, and the only possible element loss that may cause significant catalyst layer thickness change is carbon. Since the cation tends to accumulate in the cathode catalyst layer during the fuel cell test, it is hypothesized that the cation accumulation in the catalyst layer can render the Pt inactive, and either directly or indirectly increases the carbon oxidation reaction rate resulting in catalyst layer thinning.
Preparations of Highly Stable RuCo/CNTs Electrocatalysts for Oxygen Reduction Reaction
Authors: Gao Dong , Li Hengyi , Cheng Xuan
Published: August 2015

The ruthenium-based chalcogenide catalysts such as ruthenium selenides have been shown to display good electrocatalytic activity toward oxygen reduction reaction (ORR) in acidic media. In this investigation, the carbon nanotubes (CNTs) supported RuCo alloyed nanoparticles (RuCo/CNTs) were prepared with different Ru/Co ratios (Ru/Co=0.5, 1.0, 2.0, 3.0) by impregnated method followed by heat treatments using less expansive metal chlorides as precursors. It was found that the RuCo nanoparticles were uniformly dispersed on the CNTs support and exhibited hexagonal alloyed phase with small amounts of metal oxides at the surface. The mean particle sizes were smaller than 10 nm and the potentials corresponding to oxygen reduction reaction were 0.67~0.73 V with the electron transfer numbers (n) of 3.0~4.0. The amounts of Co presented in the alloy significantly influenced the growth of nanoparticles and the defects of CNTs support. The best ORR activity with high stability in an acid solution was achieved with the RuCo/CNTs catalyst prepared with Ru/Co=2.0.
Two weeks of high-intensity interval training improves novel but not traditional cardiovascular disease risk factors in adolescents
Authors: Bond Bert , Cockcroft Emma J. , Williams Craig A. , Harris Sam , Gates Phillip E. , Jackman Sarah R. , Armstrong Neil , Barker Alan R.
Published: August 2015

High-intensity interval training (HIIT) improves traditional cardiovascular disease (CVD) risk factors in adolescents, but no study has identified the influence of HIIT on endothelial and autonomic function in this group. Thirteen 13- to 14-yr-old adolescents (6 girls) completed six HIIT sessions over 2 wk. Each training session consisted of eight to ten 1-min repetitions of cycling at 90% peak power interspersed with 75 s of unloaded cycling. Traditional (triglycerides, cholesterol, glucose, insulin, and blood pressure) and novel [flow-mediated dilation (FMD), heart rate variability (HRV)] CVD risk factors were assessed in a fasted and postprandial state before (PRE), 1 day after (POST-1D), and 3 days after (POST-3D) training. Aerobic fitness was determined PRE and POST-3D. Two weeks of HIIT had no effect on aerobic fitness or traditional CVD risk factors determined in the fasted or postprandial state ( P > 0.15). Compared with PRE, fasted FMD was improved POST-1D [ P = 0.003, effect size (ES) = 0.70] but not POST-3D ( P = 0.32, ES = 0.22). Fasted FMD was greater POST-1D compared with POST-3D ( P = 0.04, ES = 0.48). Compared with PRE, postprandial FMD was greater POST-1D ( P < 0.001, ES = 1.01) and POST-3D ( P = 0.01, ES = 0.60). Fasted HRV was greater POST-1D ( P = 0.001, ES = 0.71) and POST-3D ( P = 0.02, ES = 0.44). The test meal lowered HRV in all laboratory visits ( P < 0.001, ES = 0.59), but there were no differences in postprandial HRV between visits ( P > 0.32 for all). Two weeks of HIIT enhanced endothelial function and HRV without improvements in traditional CVD risk factors. However, most of this favorable adaptation was lost POST-3D, suggesting that regularly performing high-intensity exercise is needed to maintain these benefits.
Blockade of Ets-1 attenuates epidermal growth factor-dependent collagen loss in human carotid plaque smooth muscle cells
Authors: Rao Velidi H. , Rai Vikrant , Stoupa Samantha , Agrawal Devendra K.
Published: August 2015

Although degradation of extracellular matrix by matrix metalloproteinases (MMPs) is thought to be involved in symptomatic (S) carotid plaques in atherosclerosis, the mechanisms of MMP expression are poorly understood. Here, we demonstrate that collagen loss in vascular smooth vessel cells (VSMCs) isolated from S plaques was induced by epidermal growth factor (EGF) through the activation of p38-MAPK and JNK-MAPK pathways. Inhibitors of p38-MAPK and JNK-MAPK signaling pathways downregulated the expression of MMP-1 and MMP-9. In addition, we examined whether v-ets erythroblastosis virus E26 oncogene homologue 1 (Ets-1), an important regulator of different genes, is involved in destabilizing S plaques in patients with carotid stenosis. We demonstrate that EGF induces Ets-1 expression and decreases interstitial and basement membrane collagen in vascular smooth muscle cells (VSMCs) from patients with carotid stenosis. Increased expression of MMP-1 and -9 and decreased collagen mRNA transcripts were also found in Ets-1-overexpressed VSMCs. Transfection with both dominant-negative form of Ets-1 and small interfering RNA blocked EGF-induced MMP-1 and -9 expressions and increased the mRNA transcripts for collagen I (α1) and collagen III (α1) in S compared with asymptomatic (AS) carotid plaques. Inhibitors of p38-MAPK (SB202190) and JNK-MAPK (SP600125) signaling pathways decreased the expression of Ets-1, MMP-1, and MMP-9 and increased collagen type I and III expression in EGF-treated VSMCs. This study provides a mechanistic insight into the role of Ets-1 in the plaque destabilization in patients with carotid stenosis involving p38-MAPK and JNK signaling pathways.
Computational genomic analysis of PARK7 interactome reveals high BBS1 gene expression as a prognostic factor favoring survival in malignant pleural mesothelioma
Authors: Vavougios Georgios D. , Solenov Evgeniy I. , Hatzoglou Chrissi , Baturina Galina S. , Katkova Liubov E. , Molyvdas Paschalis Adam , Gourgoulianis Konstantinos I. , Zarogiannis Sotirios G.
Published: August 2015

The aim of our study was to assess the differential gene expression of Parkinson protein 7 (PARK7) interactome in malignant pleural mesothelioma (MPM) using data mining techniques to identify novel candidate genes that may play a role in the pathogenicity of MPM. We constructed the PARK7 interactome using the ConsensusPathDB database. We then interrogated the Oncomine Cancer Microarray database using the Gordon Mesothelioma Study, for differential gene expression of the PARK7 interactome. In ConsensusPathDB, 38 protein interactors of PARK7 were identified. In the Gordon Mesothelioma Study, 34 of them were assessed out of which SUMO1, UBC3, KIAA0101, HDAC2, DAXX, RBBP4, BBS1, NONO, RBBP7, HTRA2, and STUB1 were significantly overexpressed whereas TRAF6 and MTA2 were significantly underexpressed in MPM patients ( network 2). Furthermore, Kaplan-Meier analysis revealed that MPM patients with high BBS1 expression had a median overall survival of 16.5 vs. 8.7 mo of those that had low expression. For validation purposes, we performed a meta-analysis in Oncomine database in five sarcoma datasets. Eight network 2 genes (KIAA0101, HDAC2, SUMO1, RBBP4, NONO, RBBP7, HTRA2, and MTA2) were significantly differentially expressed in an array of 18 different sarcoma types. Finally, Gene Ontology annotation enrichment analysis revealed significant roles of the PARK7 interactome in NuRD, CHD, and SWI/SNF protein complexes. In conclusion, we identified 13 novel genes differentially expressed in MPM, never reported before. Among them, BBS1 emerged as a novel predictor of overall survival in MPM. Finally, we identified that PARK7 interactome is involved in novel pathways pertinent in MPM disease.
Coming to terms with tissue engineering and regenerative medicine in the lung
Authors: Prakash Y. S. , Tschumperlin Daniel J. , Stenmark Kurt R.
Published: August 2015

Lung diseases such as emphysema, interstitial fibrosis, and pulmonary vascular diseases cause significant morbidity and mortality, but despite substantial mechanistic understanding, clinical management options for them are limited, with lung transplantation being implemented at end stages. However, limited donor lung availability, graft rejection, and long-term problems after transplantation are major hurdles to lung transplantation being a panacea. Bioengineering the lung is an exciting and emerging solution that has the ultimate aim of generating lung tissues and organs for transplantation. In this article we capture and review the current state of the art in lung bioengineering, from the multimodal approaches, to creating anatomically appropriate lung scaffolds that can be recellularized to eventually yield functioning, transplant-ready lungs. Strategies for decellularizing mammalian lungs to create scaffolds with native extracellular matrix components vs. de novo generation of scaffolds using biocompatible materials are discussed. Strengths vs. limitations of recellularization using different cell types of various pluripotency such as embryonic, mesenchymal, and induced pluripotent stem cells are highlighted. Current hurdles to guide future research toward achieving the clinical goal of transplantation of a bioengineered lung are discussed.
Hydrothermal Pretreatment of Date Palm (Phoenix dactyliferaL.) Leaflets and Rachis to Enhance Enzymatic Digestibility and Bioethanol Potential
Authors: Fang Chuanji , Schmidt Jens Ejbye , Cybulska Iwona , Brudecki Grzegorz P. , Frankær Christian Grundahl , Thomsen Mette Hedegaard
Published: August 2015

Date palm residues are one of the most promising lignocellulosic biomass for bioethanol production in the Middle East. In this study, leaflets and rachis were subjected to hydrothermal pretreatment to overcome the recalcitrance of the biomass for enzymatic conversion. Evident morphological, structural, and chemical changes were observed by scanning electron microscopy, X-ray diffraction, and infrared spectroscopy after pretreatment. High glucan (>90% for both leaflets and rachis) and xylan (>75% for leaflets and >79% for rachis) recovery were achieved. Under the optimal condition of hydrothermal pretreatment (210°C/10 min) highly digestible (glucan convertibility, 100% to leaflets, 78% to rachis) and fermentable (ethanol yield, 96% to leaflets, 80% to rachis) solid fractions were obtained. Fermentability test of the liquid fractions proved that no considerable inhibitors toSaccharomyces cerevisiaewere produced in hydrothermal pretreatment. Given the high sugar recovery, enzymatic digestibility, and ethanol yield, production of bioethanol by hydrothermal pretreatment could be a promising way of valorization of date palm residues in this region.