bluuebunny/crossref_metadata_2025 huggingface dataset:
An external validation study of a clinical prediction rule for medical patients with suspected bacteraemia
Authors: Hodgson Luke Eliot , Dragolea Nicholas , Venn Richard , Dimitrov Borislav D , Forni Lui G
Published: August 2015

Objective

The objective of this study was to externally validate a clinical prediction rule (CPR)—the ‘Shapiro criteria’—to predict bacteraemia in an acute medical unit (AMU).

Methods

Prospectively collected data, retrospectively evaluated over 11 months in an AMU in the UK. From 4810 admissions, 635 patients (13%) had blood cultures (BCs) performed. The 100 cases of true bacteraemia were compared with a randomly selected sample of 100 control cases where BCs were sterile.

Results

To predict bacteraemia (at a cut-off score of two points), the Shapiro criteria had a sensitivity of 97% (95% CIs 91% to 99%), specificity 37% (28% to 47%), positive likelihood ratio 1.54 (1.3 to 1.8) and a negative likelihood ratio of 0.08 (0.03 to 0.25). The area under the receiver operating curve was 0.80 (0.74 to 0.86), and the Hosmer–Lemeshow p value was 0.45.

Conclusions

A cut-off score of two points on the Shapiro criteria had high sensitivity to predict bacteraemia in a study of acute general medical admissions. Application of the rule in patients being considered for a BC could identify those at low risk of bacteraemia. Though the model demonstrated good discrimination, the lengthy number of variables (13) and difficulty automating the CPR may limit its use.
Deaths of teenagers in car crashes: a child death review
Authors: Jones Sarah J , Heatman Beverley
Published: August 2015

MVCs are a leading cause of death and disability for teenagers. In Wales, a child death review process has been established to carry out thematic reviews of deaths; this approach is believed to highlight opportunities for prevention that individual case review could not. Cases were 13-year-old to 17-year-old Welsh residents who died as car drivers or passengers between 1 January 2006 and 31 December 2010. An expert panel was convened to review these cases. 28 MVCs occurred and 34 13–17 year olds died; 24 males, 10 females. 51 vehicles were involved; 23 driven by 17-year-old to 19-year-old males. 19 of the 28 MVCs occurred between 21:00 and 05:00. The risk factors identified were consistent with global research on MVC deaths and injuries to teenagers. However, there is a lack of effective interventions to tackle these in the UK. It is recommended that the implementation of Graduated Driver Licensing is considered.
Shifting abortion care from a hospital to a community sexual and reproductive health care setting
Authors: Cameron Sharon T , Glasier Anna , Johnstone Anne
Published: August 2015

Background

Community sexual and reproductive health (SRH) services are well placed to deliver abortion assessment services and early medical abortion (EMA), but comparative data on safety and acceptability from both settings are important for future service planning.

Methods

Retrospective review of computerised records of 1342 women undergoing outpatient EMA (≤9 weeks) in a community SRH or hospital department of gynaecology in the same city, and a self-completed, anonymous survey of 303 women requesting abortion at both sites. Primary outcome was safety in terms of re-attendance rates for a complication related to EMA. Secondary outcomes were telephone contact with each site for an EMA-related concern and satisfaction with information about abortion (defined as score out of 10) received at each site.

Results

There was no difference in re-attendance rates to either service for a complication following outpatient EMA (2.7%). A higher proportion of women undergoing EMA at the SRH site made telephone contact compared to women at the hospital site (18.8% vs 10.8%;p=0.033). Women rated both settings highly in terms of information received before abortion (9.2 and 9.6 out of 10) at the hospital and SRH sites, respectively.

Conclusions

This study suggests that provision of outpatient EMA in a community SRH setting is as safe as that delivered from a hospital setting, and that women are similarly satisfied with the information they receive about abortion from each setting. More abortion assessment and outpatient EMA services in Great Britain could shift from hospital to community SRH settings.
Appetite-related peptides in childhood and adolescence: role of ghrelin, PYY, and GLP-1
Authors: Horner Katy , Lee SoJung
Published: August 2015

During childhood and adolescence, a number of factors, including age, puberty, sex, race, and body composition, may contribute to differences in satiety, food intake, and appetite-related peptides. These peptides include the orexigenic peptide ghrelin and anorexigenic gut peptides peptide YY (PYY) and glucagon-like peptide-1 (GLP-1). For example, lower fasting ghrelin levels, lower postprandial ghrelin suppression, and blunted PYY and GLP-1 responses to food intake could contribute to a dysregulation of appetite in already obese children and adolescents. Whereas, changes in these peptides observed during puberty could facilitate growth. A greater understanding of the major moderating factors of appetite-related peptides in the pediatric population is essential to improve interpretation of study findings and for effective tailoring of strategies targeting appetite control to individuals. While more studies are needed, there is some evidence to suggest that exercise-based lifestyle interventions could be a potential therapeutic strategy to improve appetite-peptide profiles in overweight and obese children and adolescents. The aim of this review is (i) to discuss the potential moderating factors of ghrelin, PYY, and GLP-1, including age and puberty, sex, race and body composition; and (ii) to examine the effects of exercise interventions on these appetite-related gut peptides in children and adolescents.
Propagators of charged particles in an external magnetic field, expanded over Landau levels
Authors: Kuznetsov A. V. , Okrugin A. A. , Shitova A. M.
Published: August 2015

Various forms of expressions for the propagators of charged particles in a constant magnetic field that should be used for investigations of electroweak processes in an external uniform magnetic fields are discussed. Formulas for the propagators of the Standard Model charged [Formula: see text]- and scalar [Formula: see text]-bosons in an arbitrary [Formula: see text]-gauge, expanded over Landau levels, are derived for the first time.
Efficient Mining of Data Streams Using Associative Classification Approach
Authors: Kompalli Prasanna Lakshmi , Cherku Ramesh Kumar
Published: August 2015

Data stream associative classification poses many challenges to the data mining community. In this paper, we address four major challenges posed, namely, infinite length, extraction of knowledge with single scan, processing time, and accuracy. Since data streams are infinite in length, it is impractical to store and use all the historical data for training. Mining such streaming data for knowledge acquisition is a unique opportunity and even a tough task. A streaming algorithm must scan data once and extract knowledge. While mining data streams, processing time, and accuracy have become two important aspects. In this paper, we propose PSTMiner which considers the nature of data streams and provides an efficient classifier for predicting the class label of real data streams. It has greater potential when compared with many existing classification techniques. Additionally, we propose a compact novel tree structure called PSTree (Prefix Streaming Tree) for storing data. Extensive experiments conducted on 24 real datasets from UCI repository and synthetic datasets from MOA (Massive Online Analysis) show that PSTMiner is consistent. Empirical results show that performance of PSTMiner is highly competitive in terms of accuracy and performance time when compared with other approaches under windowed streaming model.
Multi-Attribute Utility Theory for Estimation of Optimal Release Time and Change-Point
Authors: Minamino Yuka , Inoue Shinji , Yamada Shigeru
Published: August 2015

Existing optimal software release problems have been discussed by using an evaluation criterion such as cost, reliability, delivery. When we use the methods by those evaluation criteria, the optimal release time is determined by an evaluation criterion. However, it is more realistic that we determine the optimal release time with multiple attributes. Therefore, in this study, we estimate the optimal release time by using multi-attribute utility theory (MAUT). Since MAUT is one of utility theories, we can estimate an optimal release time and change-point from the perspective of utility by maximizing the multi-attribute utility function. Especially, we consider the both of two attributes: cost and reliability. Then, we apply a software reliability growth model (SRGM) with change-point to represent the cost and reliability attributes. Concretely, we use an exponential SRGM with change-point. That is, we can estimate not only the optimal release time but also change-point. Finally, we show numerical examples by using actual data sets. Especially, we check the behavior of the optimal release time, change-point, total software cost and utility.
Enhancement of nonlinear optical property in ZnS PVA films due to self-assembly
Authors: Mathew S. , Vaishak Manu , Samuel Boni , Libish T. M. , Radhakrishnan P. , Nampoori V. P. N. , Vallabhan C. P. G.
Published: August 2015

Nanostructured zinc sulfide ( ZnS ) thin films were synthesized in polyvinyl alcohol matrix by chemical bath deposition and self-assembly techniques. ZnS nanostructured thin films show second harmonic generation (SHG) under irradiation with a pico-second Nd :YAG laser system and the second harmonic intensity is higher for self-assembled nanotree like structured ZnS thin film in comparison with that from chemical bath deposited thin film. Under nanosecond laser pulses, thin films possess good saturable absorption behavior. The optical bandgap and visible luminescence also get enhanced.
Lower–Middle Jurassic facies patterns in the NW Afghan–Tajik Basin of southern Uzbekistan and their geodynamic context
Authors: Fürsich Franz T. , Brunet Marie-Françoise , Auxiètre Jean-Luc , Munsch Hermann
Published: August 2015

Based on 11 sections, the palaeoenvironments and depositional history of the NW Afghan–Tajik Basin in southern Uzbekistan have been reconstructed for the time interval of the Early Jurassic–Early Callovian. The earliest sediments, resting on Palaeozoic basement rocks, date from the Early Jurassic Period. Up to the end of the Early Bajocian time, more than 500 m of non-marine sediments accumulated as a result of extensional tectonics inducing active subsidence. In the Late Bajocian time interval, transgression led to the establishment of siliciclastic ramps that were influenced by storm processes. After a condensed unit in the Middle Bathonian, sedimentation resumed in an outer carbonate ramp–basinal setting as the subsidence rate outpaced the diminished siliciclastic sediment supply. The change from siliciclastic to carbonate sedimentation in the Middle Jurassic Period is thought to be multifactorial, reflecting levelling of relief in the hinterland, the subsidence moving to a thermally more quiet stage and a change from humid to arid climatic conditions. These features are also observed in the area of present-day Iran. Similarly, the timing of the transgression coincides with that in eastern and northern Iran, stressing the regional significance of this event.
On Computing the Gromov Hyperbolicity
Authors: Cohen Nathann , Coudert David , Lancin Aurélien
Published: August 2015

The Gromov hyperbolicity is an important parameter for analyzing complex networks which expresses how the metric structure of a network looks like a tree. It is for instance used to provide bounds on the expected stretch of greedy-routing algorithms in Internet-like graphs. However, the best-known theoretical algorithm computing this parameter runs in
O
(
n
3.69
) time, which is prohibitive for large-scale graphs.

In this article, we propose an algorithm for determining the hyperbolicity of graphs with tens of thousands of nodes. Its running time depends on the distribution of distances and on the actual value of the hyperbolicity. Although its worst case runtime is
O
(
n
4
), it is in practice much faster than previous proposals as observed in our experimentations. Finally, we propose a heuristic algorithm that can be used on graphs with millions of nodes. Our algorithms are all evaluated on benchmark instances.
Synthesis of machine code from semantics
Authors: Srinivasan Venkatesh , Reps Thomas
Published: August 2015

In this paper, we present a technique to synthesize machine-code instructions from a semantic specification, given as a Quantifier-Free Bit-Vector (QFBV) logic formula. Our technique uses an instantiation of the Counter-Example Guided Inductive Synthesis (CEGIS) framework, in combination with search-space pruning heuristics to synthesize instruction-sequences. To counter the exponential cost inherent in enumerative synthesis, our technique uses a divide-and-conquer strategy to break the input QFBV formula into independent sub-formulas, and synthesize instructions for the sub-formulas. Synthesizers created by our technique could be used to create semantics-based binary rewriting tools such as optimizers, partial evaluators, program obfuscators/de-obfuscators, etc. Our experiments for Intel's IA-32 instruction set show that, in comparison to our baseline algorithm, our search-space pruning heuristics reduce the synthesis time by a factor of 473, and our divide-and-conquer strategy reduces the synthesis time by a further 3 to 5 orders of magnitude.
Concurrency debugging with differential schedule projections
Authors: Machado Nuno , Lucia Brandon , Rodrigues Luís
Published: August 2015

We present Symbiosis: a concurrency debugging technique based on novel differential schedule projections (DSPs). A DSP shows the small set of memory operations and data-flows responsible for a failure, as well as a reordering of those elements that avoids the failure. To build a DSP, Symbiosis first generates a full, failing, multithreaded schedule via thread path profiling and symbolic constraint solving. Symbiosis selectively reorders events in the failing schedule to produce a non-failing, alternate schedule. A DSP reports the ordering and data-flow differences between the failing and non-failing schedules. Our evaluation on buggy real-world software and benchmarks shows that, in practical time, Symbiosis generates DSPs that both isolate the small fraction of event orders and data-flows responsible for the failure, and show which event reorderings prevent failing. In our experiments, DSPs contain 81% fewer events and 96% less data-flows than the full failure-inducing schedules. Moreover, by allowing developers to focus on only a few events, DSPs reduce the amount of time required to find a valid fix.
Synthesis of ranking functions using extremal counterexamples
Authors: Gonnord Laure , Monniaux David , Radanne Gabriel
Published: August 2015

We present a complete method for synthesizing lexicographic linear ranking functions (and thus proving termination), supported by inductive invariants, in the case where the transition relation of the program includes disjunctions and existentials (large block encoding of control flow). Previous work would either synthesize a ranking function at every basic block head, not just loop headers, which reduces the scope of programs that may be proved to be terminating, or expand large block transitions including tests into (exponentially many) elementary transitions, prior to computing the ranking function, resulting in a very large global constraint system. In contrast, our algorithm incrementally refines a global linear constraint system according to extremal counterexamples: only constraints that exclude spurious solutions are included. Experiments with our tool Termite show marked performance and scalability improvements compared to other systems.
Synthesizing data structure transformations from input-output examples
Authors: Feser John K. , Chaudhuri Swarat , Dillig Isil
Published: August 2015

We present a method for example-guided synthesis of functional programs over recursive data structures. Given a set of input-output examples, our method synthesizes a program in a functional language with higher-order combinators like map and fold. The synthesized program is guaranteed to be the simplest program in the language to fit the examples. Our approach combines three technical ideas: inductive generalization, deduction, and enumerative search. First, we generalize the input-output examples into hypotheses about the structure of the target program. For each hypothesis, we use deduction to infer new input/output examples for the missing subexpressions. This leads to a new subproblem where the goal is to synthesize expressions within each hypothesis. Since not every hypothesis can be realized into a program that fits the examples, we use a combination of best-first enumeration and deduction to search for a hypothesis that meets our needs. We have implemented our method in a tool called λ2, and we evaluate this tool on a large set of synthesis problems involving lists, trees, and nested data structures. The experiments demonstrate the scalability and broad scope of λ2. A highlight is the synthesis of a program believed to be the world's earliest functional pearl.
Algorithmic debugging of real-world haskell programs: deriving dependencies from the cost centre stack
Authors: Faddegon Maarten , Chitil Olaf
Published: August 2015

Existing algorithmic debuggers for Haskell require a transformation of all modules in a program, even libraries that the user does not want to debug and which may use language features not supported by the debugger. This is a pity, because a promising approach to debugging is therefore not applicable to many real-world programs. We use the cost centre stack from the Glasgow Haskell Compiler profiling environment together with runtime value observations as provided by the Haskell Object Observation Debugger (HOOD) to collect enough information for algorithmic debugging. Program annotations are in suspected modules only. With this technique algorithmic debugging is applicable to a much larger set of Haskell programs. This demonstrates that for functional languages in general a simple stack trace extension is useful to support tasks such as profiling and debugging.
Verifying read-copy-update in a logic for weak memory
Authors: Tassarotti Joseph , Dreyer Derek , Vafeiadis Viktor
Published: August 2015

Read-Copy-Update (RCU) is a technique for letting multiple readers safely access a data structure while a writer concurrently modifies it. It is used heavily in the Linux kernel in situations where fast reads are important and writes are infrequent. Optimized implementations rely only on the weaker memory orderings provided by modern hardware, avoiding the need for expensive synchronization instructions (such as memory barriers) as much as possible. Using GPS, a recently developed program logic for the C/C++11 memory model, we verify an implementation of RCU for a singly-linked list assuming "release-acquire" semantics. Although release-acquire synchronization is stronger than what is required by real RCU implementations, it is nonetheless significantly weaker than the assumption of sequential consistency made in prior work on RCU verification. Ours is the first formal proof of correctness for an implementation of RCU under a weak memory model.
Relaxing safely: verified on-the-fly garbage collection for x86-TSO
Authors: Gammie Peter , Hosking Antony L. , Engelhardt Kai
Published: August 2015

We report on a machine-checked verification of safety for a state-of-the-art, on-the-fly, concurrent, mark-sweep garbage collector that is designed for multi-core architectures with weak memory consistency. The proof explicitly incorporates the relaxed memory semantics of x86 multiprocessors. To our knowledge, this is the first fully machine-checked proof of safety for such a garbage collector. We couch the proof in a framework that system implementers will find appealing, with the fundamental components of the system specified in a simple and intuitive programming language. The abstract model is detailed enough for its correspondence with an assembly language implementation to be straightforward.
Current Trends and Challenges in Biointerfaces Science and Engineering
Authors: Ross A.M. , Lahann J.
Published: August 2015

The cellular microenvironment is extremely complex, and a plethora of materials and methods have been employed to mimic its properties in vitro. In particular, scientists and engineers have taken an interdisciplinary approach in their creation of synthetic biointerfaces that replicate chemical and physical aspects of the cellular microenvironment. Here the focus is on the use of synthetic materials or a combination of synthetic and biological ligands to recapitulate the defined surface chemistries, microstructure, and function of the cellular microenvironment for a myriad of biomedical applications. Specifically, strategies for altering the surface of these environments using self-assembled monolayers, polymer coatings, and their combination with patterned biological ligands are explored. Furthermore, methods for augmenting an important physical property of the cellular microenvironment, topography, are highlighted, and the advantages and disadvantages of these approaches are discussed. Finally, the progress of materials for prolonged stem cell culture, a key component in the translation of stem cell therapeutics for clinical use, is featured.
Graphene Nanoplatelets Embedded in HfO2 for MOS Memory
Authors: El-Atab Nazek , Turgut Berk Berkan , Okyay Ali , Nayfeh Ammar
Published: August 2015

In this work, a MOS memory with graphene nanoplatelets charge trapping layer and a double layer high-қ Al2O3/HfO2 tunnel oxide is demonstrated. Using C-Vgate measurements, the memory showed a large memory window at low program/erase voltages. The analysis of the C-V characteristics shows that electrons are being stored in the graphene-nanoplatelets during the program operation. In addition, the retention characteristic of the memory is studied by plotting the hysteresis measurement vs. time. The measured excellent retention characteristic (28.8% charge loss in 10 years) is due to the large electron affinity of the graphene. The analysis of the plot of the energy band diagram of the MOS structure further proves its good retention characteristic. Finally, the results show that such graphene nanoplatelets are promising in future low-power non-volatile memory devices.
Thorium-234 Electrodeposition Using Ionic and Aqueous Uranyl Solutions
Authors: Saliba-Silva Adonis Marcelo , Linardi Marcelo , Dos Santos Rocha Lucas , Durazzo Michelangelo
Published: August 2015

Electrodeposition process of natural uranyl many has several deposit possibilities, since the process variables and uranium natural isotopes and secular equilibrium may induce the formation of several uranium compounds. One of these deposit possibilities is the strong beta-emitter thorium-234. The present work showed that pulsed polarization and 2-propanol natural uranyl solution (50 mM [U]) induced the formation of intense beta-emission in the samples, with activity beta-alpha ratio reaching levels of 300, which is much higher than the secular equilibrium ratio around 1. The natural decay of the deposited samples showed that the beta-emitter as most probable element to be thorium-234 within a pertinent regression exponential decay curve adjustment (R2=0.998) giving a typical experimentation value for half-life as 22.88 days. This value was found lower than the typical 24.10 days for thorium-234 (specific activity of 85.69x1013 Bq/g), probably due to activity contribution of uranium-235 daughter, thorium-231 (specific activity of 19.67x1015 Bq/g), which beta-decays having half-life of 25.6 h. Further experimentation with pulsed polarization of the cathode (0 to -15V; 12.5 Hz – duty time = 87.5% and process time varying until 3600s) also showed that thorium-234 depends on solution acidity, solution usage and deposition time. XRD spectra suggests that the deposit would be probably a combined structure of uranium-thorium hydride, which decomposes with time.
Improving Electrosorption Performance in Membrane Assisted Capacitive Deionization Cells Using Asymmetric Electrodes Configuration
Authors: Omosebi Ayokunle , Li Zhiao , Gao Xin , Landon James , Liu Kunlei
Published: August 2015

Membrane capacitive deionization (MCDI) is an emerging salt treatment technology that performs beyond the capabilities of traditional capacitive deionization cells due its ability to mitigate unwanted ion expulsion events. We present a dynamic model for observing the concentration response of deionization cells configured in a recirculating batch setup. The model consists of two volumes representing the deionization cell and the reservoir where salt storage and mixing respectively occur. The model was used to fit a typical MCDI cell made up of two similar electrodes each with potential of zero charge (EPZC) values of ~-0.2 V vs saturated calomel electrode (SCE), and an asymmetric MCDI cell with respective anode and cathode EPZCs at ~-0.2 and ~+0.2 V vs. SCE. The model predicts increases of up to 50% and 10% in capacity and efficiency, respectively, for the asymmetric MCDI cell.
Electrosynthesis of Heterocyclic Compounds by Radical Cyclization in Environmentally Friendly Media
Authors: Mendes J.P. , Esperança J.M. S.S. , Esteves A. P. , Silva M. M. , Medeiros M.J.
Published: August 2015

We investigated the reductive intramolecular cyclization of bromopropargyl ethers derivatives, catalyzed by electrogenerated (1,4,8,11-tetramethyl-1,4,8,11-tetraaza-cyclotetradecane)nickel(I), [Ni(tmc)]+ as the catalysts in N,N,N-trimethyl-N-(2-hydroxyethyl)ammonium bis(trifluoromethylsulfonyl)imide,[N1 1 1 2(OH)][NTf2] and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C2mim][NTf2] by cyclic voltammetry and controlled-potential electrolysis. The results show that the reaction leads to the formation of the expected cyclic compounds, which are important intermediates in the synthesis of natural products with possible biological activities.
Electrochemical and Spectrophotometric Study of the Hydration of Orthophthalaldehyde and Its Reaction with Amines and Aminoacids
Authors: Kantnerová Kristýna , Donkeng Dazie Joel , Ludvík Jiří
Published: August 2015

Reactions of orthophthalaldehyde (OPA) with aliphatic α-amino acids and with aliphatic primary amines were studied in buffered aqueous solution and in non-aqueous acetonitrile. For comparison lysine and glycine ethyl ester were used. The role of the substitution on the α-carbon was discovered and the effect of OPA hydration on the course of the reaction was also investigated. In contrary to the published information, the dialdehydic unhydrated form is not the primary reactive species and for the successful reaction of OPA with amines, the presence of water is necessary.
Electrochemical Explorations of 9,10-Anthraquinone/Hafnium(IV) Ion Interactions in Nonaqueous Solvents
Authors: Cheek Graham T.
Published: August 2015

The effect of hafnium(IV) trifluoromethanesulfonate [Hf(TfO)4] on the electrochemical behavior of 9,10-anthraquinone (AQ) has been studied in adiponitrile (ADN). AQ undergoes two successive reversible one-electron redox processes in ADN. Addition of Hf(TfO)4 produces a positive reduction peak potential shift due to formation of the complexes Hf(AQ)4+, then Hf2(AQ)8+, as Hf(TfO)4 is added. The reduction of these complexes leads to the appearance of the same oxidation peak, which is assigned to oxidation of Hf(AQ)3
2-. The peak potential shift is greater than that observed for addition of Al(TfO)3, indicating that Hf4+ interacts more extensively with AQ than does Al3+.
Determination of Inorganic Arsenic As(III) in Water by Linear Sweep Anodic Stripping Voltammetry Using Gold Ultra-Microelectrode Array
Authors: Duong Quyet Nguyen , Le Nghiem Van , Le Thuong Dinh , Nguyen Hoang Thai , Tong Hien Duy , Nguyen Thoa Thi Phuong
Published: August 2015

A gold ultra-microelectrode array has been developed for the determination of arsenic As(III) ions by linear sweep anodic stripping voltammetry (LSASV). The deposition potential (Edep) and time (tdep) and supporting electrolytes were investigated. The repeatability, linearity, accuracy of the proposed method and the effect of pH and interference ions were evaluated. It was found that As(III) can be determined by the proposed method using our developed gold ultra-microwire electrode at any pH including the pH values typical for natural waters. Well defined voltammetric waves at Edep = -0.450 V (vs. Ag/AgCl/3M KCl reference electrode), tdep = 100 s and 1.000 V.s-1 scan rate are obtained in 1M H3PO4 supporting electrolyte. A good linear relationship between LSASV peak current and As(III) concentration is observed for the typical values in natural waters and in arsenic contaminated ones. The limit of detection was 2 ng.L-1 (signal-to-noise ratio = 3). The obtained results suggested that the fabricated gold chip would facilitate monitoring of As(III) in natural waters by linear sweep anodic stripping voltammetry.
In Situ STM Studies of Electrochemically Polished Cd(0001) Electrode in 1-Ethyl-3-Methylimidazolium Tetrafluoroborate
Authors: Pikma Piret , Siinor Liis , Selberg Simona , Lust Enn
Published: August 2015

The in situ scanning tunneling microscopy (STM) and electrochemical impedance spectroscopy studies of electrochemically polished Cd(0001) electrode have been performed in the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) ionic liquid within electrode potential region from -1.6 V to –0.9 V (vs. Ag|AgCl|EMImBF4). The in situ STM data show that there are no quick surface reconstruction processes and the ideal surface structure of Cd(0001), very similar to that previously observed in aqueous electrolyte, has been established.
(Invited) Making Electrochemical Research Accessible to an Undergraduate Audience
Authors: LeSuer Robert J
Published: August 2015

In principle, undergraduate students are introduced to electrochemical reactions within the first year of the chemistry program. In practice, the amount of content covered in the second semester of general chemistry is oftentimes limited to oxidation numbers and possibly balancing redox reactions. Coverage of electrochemical concepts in higher level classes seems to be largely dependent on how comfortable the instructor is with the material. Presented here is one approach towards establishing a rigorous research program designed to train and teach undergraduate students utilizing principles derived from Bloom's taxonomy of learning. Development of a successful electrochemical research program has involved several factors, including: the use of active learning strategies; creating learning outcomes based on a cognitive skills framework; incorporation of assessment tasks; developing a sense of community; integrating research into the curriculum; and an emphasis on scientific communication.
(Invited) Nanotechnology for Biosensing Applications
Authors: Williams Frances , Komirisetty Archana , Pradhan Aswini K
Published: August 2015

Sensor related research has greatly increased over the last two decades due to the need for technology and devices for health and environmental monitoring as well as for biological warfare detection. New developments in biosensor design are crucial as these devices are in increasing demand in daily life. This paper presents a device based on electrochemical sensing using a working electrode with zinc oxide (ZnO) nanorods functionalized with glucose oxidase (GOx). Among all metal oxide nanostructures, ZnO nano-materials play a significant role as a sensing element in biosensors due to their properties such as high isoelectric point (IEP), fast electron transfer, non-toxicity, biocompatibility, and chemical stability. The glucose sensor was designed and fabricated on a silicon substrate. The ZnO nanorods were grown by the hydrothermal technique. The sensor has a linear range of 0.1mM-10.6mM, sensitivity of 18.15μA cm-1 mM-1 and a limit of detection of 0.1mM.
Electrochemical Deposition of Copper on Graphene with High Heat Transfer Coefficient
Authors: Jaikumar Arvind , Santhanam Kalathur S.V. , Kandlikar Satish G , Raya I.B.P , Raghupathi P.
Published: August 2015

The electrochemical deposition of copper is carried out on graphene in a two-step process that involves the potentiostatic deposition of copper on a platinum disc electrode at -0.30 V vs saturated calomel electrode (SCE) in the first step, followed by a dip coating of graphene. The cyclic voltammetric and chronoamperometric data of copper ion in sodium sulfate as the supporting electrolyte shows enhanced currents that are due to the oxidation of the copper that is underlying graphene. The electrodeposited copper on graphene shows a porous bead like structure in scanning electron microscope (SEM). The electrochemically obtained graphene solution is dip coated on a copper chip and investigated for its pool boiling performance. An enhancement of 82% in heat transfer coefficient (HTC) was obtained compared to a plain uncoated copper chip.
Screening of Novel Anti-Corrosion Coatings by Scanning Electrochemical Microscopy (SECM)
Authors: Lee Changyoung , Calhoun Margaret C. , Dorriety William , Hanrahan Richard , Lancaster Fred , Calhoun R. L.
Published: August 2015

A variety of experiments were conducted during the course of this study to further explore variables in a previously developed protocol that screens the effectiveness of anticorrosion coatings using scanning electrochemical microscopy (SECM). Statistical data on the basic protocol as well as pH dependence of the SECM imaging are presented in this work.
Enhanced Oxygen Reduction Reactions and Stable Long-term Activity on TiO2-supported Dealloyed PtCu Nanoparticles in Acidic Aqueous Solutions
Authors: Gunji Takao , Sasaki Kengo , Jeevagan Arockiam John , Kaneko Shingo , Tanabe Toyokazu , Matsumoto Futoshi
Published: August 2015

Dealloyed PtCu nanoparticles (NPs) were prepared on titanium oxide (TiO2) surfaces with chemical reduction of Pt and Cu ion precursors using a reducing agent in an organic solvent containing TiO2, which was followed by an electrochemical dealloying process of potential cycling (-0.2~1.2 V vs. RHE). Dealloyed PtCu NPs/TiO2 shows higher and substantial electrocatalytic activities towards oxygen reduction reactions (ORR) compared to conventional carbon black-supported Pt NPs (Pt NPs/CB). The current densities at 0.9 V (vs. RHE) were -4.0 and -2.0 mAcm-2 on dealloyed PtCu NPs/TiO2 and Pt NPs/CB, respectively.
Lithium-Ion Battery Energy Storage Systems for Grid Applications
Authors: Moss Eugene Newton , Nelson Ruben , Morris Larry , Weatherspoon Mark H , Moss Pedro L.
Published: August 2015

The use of storage devices to support grid functions is seen as a viable option to meet an increasing electricity demand. Simulations performed will provide a look into the sustainability and life of a lithium-ion battery in continuous operation that can be used to support on-grid services. Specifically, COMSOL Multiphysics will be used to model a lithium manganese oxide battery and illustrate the capacity fade, solid-electrolyte interphase (SEI) formation leading to potential drop and electrolyte potential drop in the battery. These simulations will provide insight into continuous cycling phenomena of charging and discharging a battery.
Electrochemical Dealloying of a Ternary Al67Cu18Sn15 Alloy Compared with that of a Binary Al75Cu25 Alloy
Authors: Song Tingting , Yan Ming , Shi Zhiming , Atrens Andrej , Qian Ma
Published: August 2015

This paper reports on the electrochemical dealloying of a ternary Al67Cu18Sn15 (in at.% throughout the paper) alloy consisting of a-Al, Al2Cu and Sn using potentiodynamic and potentiostatic polarization measurements. When the applied potential (-0.5 V) was below the critical potential of the Al2Cu phase (-0.41 V), complete electrochemical dealloying of the binary Al75Cu25 alloy (consisting of a-Al and Al2Cu) occurred, leading to the formation of a nanoporous (52 ± 10 nm) copper (Cu) structure. However, under the same condition dealloying only occurred partially to the α-Al phase in the ternary Al67Cu18Sn15 alloy due to the suppressing influence of Sn. The electrochemical dealloying of the ternary Al67Cu18Sn15 alloy was potential dependent and involved the concurrence of dealloying and realloying as evidenced by the formation of Cu6Sn5.
Atomic Layer Deposition on Fabrics for Flame Resistance
Authors: O'Brien S , Cosgrave L , Lodge V , Povey I. M
Published: August 2015

An atomic layer deposition process for coating a wool-synthetic fabric sample with alumina was developed. The coating efficacy was evaluated by both internal and commercial indicative flame resistance studies. It was shown that untreated samples burnt to completion on removal of the ignition source, but in the case of the treated samples, the flame on the fabric extinguished rapidly on removal of the ignition source, leaving the sample intact after the test. Thermal gravimetric analysis showed that successful fire resistance treatment was achieved by addition of alumina with less than 1% weight of the fabric. It was concluded that the atomic layer deposition coating of oxide offered significant advantages in the area of fire resistance treatment, since in addition to its effectiveness, treated fabrics exhibit a negligible increase in weight, remained flexible, breathable and did not undergo any change in color or palpable texture.
Separating myoblast differentiation from muscle cell fusion using IGF-I and the p38 MAP kinase inhibitor SB202190
Authors: Gardner Samantha , Gross Sean M. , David Larry L. , Klimek John E. , Rotwein Peter
Published: August 2015

The p38 MAP kinases play critical roles in skeletal muscle biology, but the specific processes regulated by these kinases remain poorly defined. Here we find that activity of p38α/β is important not only in early phases of myoblast differentiation, but also in later stages of myocyte fusion and myofibrillogenesis. By treatment of C2 myoblasts with the promyogenic growth factor insulin-like growth factor (IGF)-I, the early block in differentiation imposed by the p38 chemical inhibitor SB202190 could be overcome. Yet, under these conditions, IGF-I could not prevent the later impairment of muscle cell fusion, as marked by the nearly complete absence of multinucleated myofibers. Removal of SB202190 from the medium of differentiating myoblasts reversed the fusion block, as multinucleated myofibers were detected several hours later and reached ∼90% of the culture within 30 h. Analysis by quantitative mass spectroscopy of proteins that changed in abundance following removal of the inhibitor revealed a cohort of upregulated muscle-enriched molecules that may be important for both myofibrillogenesis and fusion. We have thus developed a model system that allows separation of myoblast differentiation from muscle cell fusion and should be useful in identifying specific steps regulated by p38 MAP kinase-mediated signaling in myogenesis.
Phenotypic divergence in two lines ofL-Fabp−/−mice reflects substrain differences and environmental modifiers
Authors: Newberry Elizabeth P. , Kennedy Susan , Xie Yan , Luo Jianyang , Jiang Hui , Ory Daniel S. , Davidson Nicholas O.
Published: August 2015

Phenotypic divergence in diet-induced obesity (DIO) and hepatic steatosis has been reported in two independently generated lines of L-Fabp−/−mice [New Jersey (NJ) L-Fabp−/−vs. Washington University (WU) L-Fabp−/−mice]. We performed side-by-side studies to examine differences between the lines and investigate the role of genetic background, intestinal microbiota, sex, and diet in the divergent phenotypes. Fasting-induced steatosis was attenuated in both L-Fabp−/−lines compared with C57BL/6J controls, with restoration of hepatic triglyceride levels following adenoviral L-Fabp rescue. Both lines were protected against DIO after high-saturated-fat diet feeding. Hepatic steatosis was attenuated in WU but not NJ L-Fabp−/−mice, although this difference between the lines disappeared upon antibiotic treatment and cohousing. In contrast, there was phenotypic divergence in L-Fabp−/−mice fed a high cocoa butter fat diet, with WU L-Fabp−/−mice, but not NJ L-Fabp−/−mice, showing protection against both DIO and hepatic steatosis, with some sex-dependent (female > male) differences. Dense mapping revealed no evidence of unintended targeting, duplications, or deletions surrounding the Fabp1 locus in either line and only minor differences in mRNA expression of genes located near the targeted allele. However, a C57BL/6 substrain screen showed that the NJ L-Fabp−/−line contains ∼40% C57BL/6N genomic DNA, despite reports that these mice were backcrossed six generations. Overall, these findings suggest that some of the phenotypic divergence between the two L-Fabp−/−lines may reflect unanticipated differences in genetic background, underscoring the importance of genetic background in phenotypic characterization.
Ionizing radiation induces myofibroblast differentiation via lactate dehydrogenase
Authors: Judge J. L. , Owens K. M. , Pollock S. J. , Woeller C. F. , Thatcher T. H. , Williams J. P. , Phipps R. P. , Sime P. J. , Kottmann R. M.
Published: August 2015

Pulmonary fibrosis is a common and dose-limiting side-effect of ionizing radiation used to treat cancers of the thoracic region. Few effective therapies are available for this disease. Pulmonary fibrosis is characterized by an accumulation of myofibroblasts and excess deposition of extracellular matrix proteins. Although prior studies have reported that ionizing radiation induces fibroblast to myofibroblast differentiation and collagen production, the mechanism remains unclear. Transforming growth factor-β (TGF-β) is a key profibrotic cytokine that drives myofibroblast differentiation and extracellular matrix production. However, its activation and precise role in radiation-induced fibrosis are poorly understood. Recently, we reported that lactate activates latent TGF-β through a pH-dependent mechanism. Here, we wanted to test the hypothesis that ionizing radiation leads to excessive lactate production via expression of the enzyme lactate dehydrogenase-A (LDHA) to promote myofibroblast differentiation. We found that LDHA expression is increased in human and animal lung tissue exposed to ionizing radiation. We demonstrate that ionizing radiation induces LDHA, lactate production, and extracellular acidification in primary human lung fibroblasts in a dose-dependent manner. We also demonstrate that genetic and pharmacologic inhibition of LDHA protects against radiation-induced myofibroblast differentiation. Furthermore, LDHA inhibition protects from radiation-induced activation of TGF-β. We propose a profibrotic feed forward loop, in which radiation induces LDHA expression and lactate production, which can lead to further activation of TGF-β to drive the fibrotic process. These studies support the concept of LDHA as an important therapeutic target in radiation-induced pulmonary fibrosis.
Impact of leg blood flow restriction during walking on central arterial hemodynamics
Authors: Sugawara Jun , Tomoto Tsubasa , Tanaka Hirofumi
Published: August 2015

Walking exercise with limb blood flow restriction (BFR) has been shown to increase muscular mass and strength even if it is performed at low exercise intensities. Despite mounting evidence for its efficacy and the increasing popularity, the safety of BFR exercise in relation to cardiac loads has not been established. The aim of this study was to determine the response of central hemodynamics during the BFR exercise to assess its impact on cardiac load. Fifteen apparently healthy sedentary or recreationally active adults (10 men and 5 women, 27 ± 1 yr) underwent five bouts of 2-min constant treadmill walking at 2 mph with 1-min rest intervals either with or without BFR on both proximal thighs. Beat-by-beat blood pressure and hemodynamics (via Modelflow method) were measured, and central arterial hemodynamics were evaluated with pulse wave analyses via general transfer function. Incident wave amplitude (IWA) and reflected wave amplitude (RWA) were obtained by the wave separation analysis. Peripheral systolic blood pressure (SBP) increased more substantially during walking with BFR (43 ± 5% vs. baseline) than without BFR (11 ± 4% vs. baseline). Aortic SBP did not change significantly during walking without BFR, but there was a substantial elevation in aortic SBP (43 ± 5% vs. baseline) during walking with BFR. Significant effect of BFR was seen in IWA but not in RWA. These findings suggest that even during slow-speed walking, leg BFR induces substantial hypertensive responses in the aorta. However, this response could not be explained by the augmented wave reflection.
Gene expression of peripheral blood mononuclear cells is affected by cold exposure
Authors: Reynés Bàrbara , García-Ruiz Estefanía , Oliver Paula , Palou Andreu
Published: August 2015

Because of the discovery of brown adipose tissue (BAT) in humans, there is increased interest in the study of induction of this thermogenic tissue as a basis to combat obesity and related complications. Cold exposure is one of the strongest stimuli able to activate BAT and to induce the appearance of brown-like (brite) adipocytes in white fat depots (browning process). We analyzed the potential of peripheral blood mononuclear cells (PBMCs) to reflect BAT and retroperitoneal white adipose tissue (rWAT) response to 1-wk cold acclimation (4°C) at different ages of rat development (1, 2, 4, and 6 mo). As expected, cold exposure increased fatty acid β-oxidation capacity in BAT and rWAT (increased Cpt1a expression), explaining increased circulating nonesterified free fatty acids and decreased adiposity. Cold exposure increased expression of the key thermogenic gene, Ucp1, in BAT and rWAT, but only in 1-mo-old animals. Additionally, other brown/brite markers were affected by cold during the whole developmental period studied in BAT. However, in rWAT, cold exposure increased studied markers mainly at early age. PBMCs did not express Ucp1, but expressed other brown/brite markers, which were cold regulated. Of particular interest, PBMCs reflected adipose tissue-increased Cpt1a mRNA expression in response to cold (in older animals) and browning induction occurring in rWAT of young animals (1 mo) characterized by increased Cidea expression and by the appearance of a high number of multilocular CIDE-A positive adipocytes. These results provide evidence pointing to PBMCs as an easily obtainable biological material to be considered to perform browning studies with minimum invasiveness.