bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of mechanical properties and three‐body abrasive wear of functionally graded aluminum LM25/titanium carbide metal matrix composite
Authors: Radhika N. , Raghu R. 
Published: September 2017

AbstractSeveral engineering components require location specific performance under operating conditions. A compositional/microstructural gradient can provide the performance required at specific locations and these materials were named as functionally graded materials. Functionally graded aluminium metal matrix composites were generally established for the tribo‐components where high wear resistance was a necessity. Reports on three body abrasive wear behaviour of functionally graded materials was limited to date. In the present work, a new functionally graded system comprising aluminium/titanium carbide (10 wt%) was produced through stir casting route followed by centrifugal casting technique and its three body abrasive wear behaviour was investigated. Hollow cylindrical part with the dimensions of length 150 mm, outer diameter 150 mm and thickness 16 mm was obtained. Microstructural study was performed on outer (1 mm) and inner surface (13 mm) to analyze the compositional gradient across the thickness of the functionally graded composite. Hardness was measured on different surfaces along the radial distance from outer periphery and tensile test was conducted on the outer and inner zone. Abrasive wear test was conducted on different surfaces of the functionally graded composite under various loads and speeds at constant time. The microstructural results revealed that particle segregation was more at the outer surface and less at the inner surface. Wear test results showed that increase in wear rate was obtained with increase of load and decrease in wear rate was obtained with increase of speed. The outer surfaces of the functionally graded composite had greater mechanical properties and better wear resistance compared to other surfaces. Scanning electron microscopy analysis was done on the abraded surfaces and observed wear mechanisms were interpreted.
Conidia of Penicillium rubens formed at low water activities can attract more water
Authors: van Laarhoven Karel A. , Peeters Loes H. M. , Bekker Mirjam , Huinink Hendrik P. , Adan Olaf C. G. 
Published: September 2017

AbstractTo address the problem of indoor fungal growth, understanding the influence of moisture conditions on the fungal colonization process is crucial. This paper explores the influence of past moisture conditions on current processes. Specifically, it studies the growth and water sorption of conidia of Penicillium rubens formed at lower water activities (ranging from 0.86 to 0.99). For the first time, dynamic vapor sorption (DVS) is applied as a tool to quantify the water sorption of conidia as a function of the water activity at conidiation. Furthermore, growth experiments on agar and gypsum substrates are reported that relate hyphal growth rates of the mycelium from pretreated conidia to the water activity at conidiation. No effect of the conidiation water activity on mycelial growth rates is found on either gypsum or agar. It is found, however, that conidia formed at lower activities have a higher dry weight and attract more water from humid air. It is shown that both phenomena can be explained by conidia from lower activities carrying higher amounts of compatible solutes, glycerol in particular. The enhanced sorption observed in this study might constitute a mechanism through which solute reserves contribute to survival during the early steps of fungal colonization.
Reversible Broad‐Spectrum Control of Selective Reflections of Chiral Nematic Phases by Closed‐/Open‐Type Axially Chiral Azo Dopants
Authors: Nishikawa Hiroya , Mochizuki Daigou , Higuchi Hiroki , Okumura Yasushi , Kikuchi Hirotsugu 
Published: September 2017

AbstractWe demonstrate reversible RGB‐color photocontrol of a chiral nematic liquid crystal (N*LC) by using newly synthesized closed‐ and open‐type chiral dopants. The photoswitching elements in the dopants are azobenzene units on axially chiral binaphthyl cores. Owing to cis–trans photoisomerization of the azobenzene units, both closed‐ and open‐type compounds showed higher solubility, larger helical twisting power (HTP), and larger changes in HTP than conventional chiral dopants in host LCs. Thus, even at very low dopant concentrations, we successfully controlled the chirality of the induced helical structure of the N*LCs. Consequently, the N*LCs reflected right‐ and left‐handed circularly polarized light (CPL) under a light stimulus. In the N*LCs with closed‐type chiral dopants, the RGB‐color reflection was reversibly controlled within several seconds. Interestingly, the open‐type chiral dopant reversibly inverted CPL with opposite handedness in the near and short‐wave IR regions. These novel materials are expected to realize new applications and perspectives in color information and similar technologies.
Polymers in 2D confinement: A nanoscale mechanism for thermo‐mechanical reinforcement
Authors: Romo‐Uribe Angel 
Published: September 2017

Acrylate‐clay nanocomposites, a 2D confined system, exhibited unusual increase of thermo‐mechanical properties. The nature of this reinforcement can be ascribed to chain dynamics modification and therefore investigated via dynamic mechanical analysis. Transmission electron microscopy and dynamic light scattering showed a strong nanoconfined regime, 2Rh ≫ d001, whereRhis the polymer's hydrodynamic radius andd001is the clay gallery spacing. The geometrical constraints to polymer dynamics led to significantenhancementof the thermo‐mechanical properties. Adding only 1 wt% nanoclay, the glass transition temperature increased significantly,ΔTg = Tg − Tg,bulk ~ 10°C, and the dynamic modulusE′ increased 10‐fold. Analysis of dynamic mechanical spectra showed an increase of relaxation timeτ, ie, polymer dynamics retardation. Furthermore, the mechanical damping tanδwas strongly attenuated evidencing the reduction of viscous dissipation. The activation energyEaof theα‐transition increased as the confined macromolecules needed to overcome higher energy barriers to achieve configurational rearrangements. The considerable increase of mechanical modulus cannot be explained by polymer composite models, rather it was associated to a “nano‐effect,” scaling with the degree of confinement asE/Ematrix ~ (2Rh/d001)n. This study paves the road for further understanding of polymer dynamics under 2D confinement and the reinforcement mechanism of thermo‐mechanical properties.
A novel polystyrene/epoxy ultra‐fine hybrid fabric by electrospinning
Authors: Megahed A. A. , Zoalfakar Said H. , Hassan Abdalla E. A. , Ali Ashraf A. 
Published: September 2017

In this work, electrospinning technique has been used to produce a new ultra‐fine hybrid fiber from a solution consists of polystyrene (PS) and epoxy polymers in dimethylformamide (DMF) solvent. Five ratios of different weight percentages of epoxy in PS/DMF solutions of 4 different concentrations; 15, 20, 25 and 30 wt.% were made to obtain the minimum diameter of the produced hybrid fiber. The minimum obtained hybrid fiber diameter was found to be 897 ± 239 nm at a PS/epoxy ratio of 5:1 and 13.33 Berry's number. Adding epoxy to PS has reduced the electrospun fiber diameter from 2.64 ± 0.49 μm for PS only to 1.52 ± 0.72 μm for PS/epoxy hybrid ultra‐fine fibers because of the reduction in Berry's number from 12.4 to 11.53, which gives an indication for the effect of adding epoxy on the PS molecular chain entanglement in DMF. Nuclear magnetic resonance spectroscopy results unambiguously reveal the coexistence of both epoxy and PS polymers in the hybrid fiber. We hypothesize that a hydrophopic (π‐π) interaction between the benzene rings of PS and epoxy polymers could contribute to the stability of the resulting hybrid fiber under electrospinning conditions. The fact that the lack of functional groups on both of PS and epoxy polymers that can results in covalent bonding or crosslinking between the 2 polymers supports the hypothesis of hydrophopic (π‐π) interaction in the stability of the hybrid fiber. Such (π‐π) interaction is well known to contribute to DNA single strand helical structure via intrastrand staking of the consecutive purine and pyrimidine nucleobases.
Group genetic counseling: An alternate service delivery model in a high risk prenatal screening population
Authors: Cloutier Mireille , Gallagher Lauren , Goldsmith Claire , Akiki Salwa , Barrowman Nick , Morrison Shawna 
Published: September 2017

AbstractObjectiveTo address the growing demand for prenatal genetic services, group genetic counseling was explored as an alternative service delivery model for women with a positive prenatal screening result.MethodWomen were recruited from a prenatal genetic service and systematically allocated to a traditional individual appointment with a genetic counselor or a group genetic counseling session. Questionnaires were administered to assess patient psychological outcomes, knowledge, and satisfaction following individual and group genetic counseling for a positive prenatal screen. Genetic counselor time per type of patient was measured.ResultsOf 172 participants, 107 (62.2%) received group genetic counseling and 65 (37.8%) received individual genetic counseling. Both group and individual genetic counseling encounters significantly decreased patient anxiety, increased perceived personal control, decreased decisional conflict, and increased knowledge. Satisfaction was high following both methods. Anxiety was significantly decreased in women who received individual genetic counseling compared with group sessions (P < .001). Genetic counselors spent less time per group patient seen compared with individual patients.ConclusionGroup genetic counseling followed by the option of brief individual genetic counseling appears acceptable to women in a high‐risk prenatal screening population. The findings support an alternative service delivery model for prenatal genetic services that could optimize the utilization of genetic counseling resources.
PROCAL: A Set of 40 Peptide Standards for Retention Time Indexing, Column Performance Monitoring, and Collision Energy Calibration
Authors: Zolg Daniel Paul , Wilhelm Mathias , Yu Peng , Knaute Tobias , Zerweck Johannes , Wenschuh Holger , Reimer Ulf , Schnatbaum Karsten , Kuster Bernhard 
Published: September 2017

AbstractBeyond specific applications, such as the relative or absolute quantification of peptides in targeted proteomic experiments, synthetic spike‐in peptides are not yet systematically used as internal standards in bottom‐up proteomics. A number of retention time standards have been reported that enable chromatographic aligning of multiple LC–MS/MS experiments. However, only few peptides are typically included in such sets limiting the analytical parameters that can be monitored. Here, we describe PROCAL (ProteomeTools Calibration Standard), a set of 40 synthetic peptides that span the entire hydrophobicity range of tryptic digests, enabling not only accurate determination of retention time indices but also monitoring of chromatographic separation performance over time. The fragmentation characteristics of the peptides can also be used to calibrate and compare collision energies between mass spectrometers. The sequences of all selected peptides do not occur in any natural protein, thus eliminating the need for stable isotope labeling. We anticipate that this set of peptides will be useful for multiple purposes in individual laboratories but also aiding the transfer of data acquisition and analysis methods between laboratories, notably the use of spectral libraries.
Oral herbal medicines marketed in Brazil for the treatment of osteoarthritis: A systematic review and meta‐analysis
Authors: Del Grossi Moura Mariana , Lopes Luciane Cruz , Biavatti Maique Weber , Kennedy Sean Alexander , de Oliveira e Silva Maria Carolina , Silva Marcus Tolentino , de Cássia Bergamaschi Cristiane 
Published: September 2017

Herbal medications are commonly used to manage symptoms associated with osteoarthritis (OA). This systematic review evaluated the effectiveness and safety of oral medications used in Brazil for the treatment of OA. Randomized clinical trials involving adults with OA treated by a herbal medicine or a control group were eligible. The primary outcomes measured were pain, physical function, swelling, stiffness and quality of life; and the secondary outcomes were adverse events, activity limitations and treatment satisfaction. Sixteen studies were included (n = 1,741 patients) in the systematic review and nine studies in the meta‐analysis, representing 6 of the 13 herbal medicines studied: Boswellia serrata (n = 2), Curcuma longa (n = 3), Harpagophytum procumbens (n = 1), Salix daphnoides (n = 3), Uncaria guianensis (n = 2) and Zingiber officinale (n = 5). B. serrata was more effective than both placebo and valdecoxib for improvement of pain and physical function. No difference was observed for H. procumbens, C. longa and U. guianensis compared with control. Z. officinale showed improvement of pain over placebo. The evidence was insufficient to support the effective and safe use of these herbal medicines, because the quality of evidence of studies was low. This study guides managers of the Brazilian public health system and prescribers in decision‐making regarding the use of these herbal medicines for OA. Copyright © 2017 John Wiley & Sons, Ltd.
Lack of maintenance is a major challenge for stream restoration projects
Authors: Moore Harriet Elizabeth , Rutherfurd Ian D. 
Published: September 2017

AbstractEnvironmental infrastructure and practices designed to restore and protect aquatic systems are now mainstream. Yet many of these projects are failing to produce the biophysical outcomes that they are designed for because of poor maintenance. The success of restoration projects is just as much a consequence of how they are maintained, as it is how the project was initially designed and implemented. Successful maintenance relies on understanding the ecological and biological recovery trajectories of aquatic systems. Some interventions will require ongoing maintenance indefinitely, whereas others will reach a self‐sustaining point where maintenance is no longer required. Different management arrangements are required to ensure the maintenance of different types of project. Those projects that involve high costs should be managed using more robust arrangements, such as legal regulation, compared to those projects that involve lower costs. This paper describes the maintenance required for common river restoration projects and outlines a classification of projects based on maintenance and recovery trajectories. It then considers the types of management arrangements required to ensure maintenance. Finally, these points are illustrated with 3 case studies of typical restoration actions (riparian stock exclusion, fish passage, and restoring large wood loads). Projects that require ongoing maintenance, particularly those that involve high costs, such as environmental flows, require strong management arrangements to ensure successful outcomes. Voluntary instruments are more appropriate for self‐sustaining interventions. Regardless of the chosen management arrangements, monitoring and independent assessment are essential for successful maintenance.
Modeling continuous response variables using ordinal regression
Authors: Liu Qi , Shepherd Bryan E. , Li Chun , Harrell Frank E. 
Published: September 2017

We study the application of a widely used ordinal regression model, the cumulative probability model (CPM), for continuous outcomes. Such models are attractive for the analysis of continuous response variables because they are invariant to any monotonic transformation of the outcome and because they directly model the cumulative distribution function from which summaries such as expectations and quantiles can easily be derived. Such models can also readily handle mixed type distributions. We describe the motivation, estimation, inference, model assumptions, and diagnostics. We demonstrate that CPMs applied to continuous outcomes are semiparametric transformation models. Extensive simulations are performed to investigate the finite sample performance of these models. We find that properly specified CPMs generally have good finite sample performance with moderate sample sizes, but that bias may occur when the sample size is small. Cumulative probability models are fairly robust to minor or moderate link function misspecification in our simulations. For certain purposes, the CPMs are more efficient than other models. We illustrate their application, with model diagnostics, in a study of the treatment of HIV. CD4 cell count and viral load 6 months after the initiation of antiretroviral therapy are modeled using CPMs; both variables typically require transformations, and viral load has a large proportion of measurements below a detection limit.
Detecting safety‐related components in statecharts through traceability and model slicing
Authors: Kan Shuanglong , Huang Zhiqiu 
Published: September 2017

SummaryWith rapid development in software technology, more and more safety‐critical systems are software intensive. Safety issues become important when software is used to control such systems. However, there are 2 important problems in software safety analysis: (1) there is often a significant traceability gap between safety requirements and software design, resulting in safety analysis and software design are often conducted separately; and (2) the growing complexity of safety‐critical software makes it difficult to determine whether software design fulfills safety requirements. In this paper, we propose a technique to address the above 2 important problems on the model level. The technique is based on statecharts, which are used to model the behavior of software, and fault tree safety analysis. This technique contains the following 2 parts, which are corresponding to the 2 problems, respectively. The first part is to build a metamodel of traceability between fault trees and statecharts, which is to bridge their traceability gap. A collection of rules for the creation and maintenance of traceability links is provided. The second part is a model slicing technique to reduce the complexity of statecharts with respect to the traceability information. The slicing technique can deal with the characteristics of hierarchy, concurrency, and synchronization of statecharts. The reduced statecharts are much smaller than their original statecharts, which are helpful to successive safety analysis. Finally, we illustrate the effectiveness and the importance of the method by a case study of slats and flaps control units in flight control systems.
CoopREP: Cooperative record and replay of concurrency bugs
Authors: Machado Nuno , Romano Paolo , Rodrigues Luís 
Published: September 2017

SummaryThis paper presents CoopREP, a system that provides support for fault replication of concurrent programs based on cooperative recording and partial log combination. CoopREP uses partial logging to reduce the amount of information that a given program instance is required to store to support deterministic replay. This allows reducing substantially the overhead imposed by the instrumentation of the code, but raises the problem of finding a combination of logs capable of replaying the fault. CoopREP tackles this issue by introducing several innovative statistical analysis techniques aimed at guiding the search of the partial logs to be combined and needed for the replay phase. CoopREP has been evaluated using both standard benchmarks for multithreaded applications and real‐world applications. The results highlight that CoopREP can successfully replay concurrency bugs involving tens of thousands of memory accesses, while reducing recording overhead with respect to state‐of‐the‐art noncooperative logging schemes by up to 13× (and by 2.4× on average).
Carbonic anhydrase inhibitor acetazolamide shifts synaptic vesicle recycling to a fast mode at the mouse neuromuscular junction
Authors: Bertone Nicolas Ivan , Groisman Ayelén Ivana , Mazzone Graciela Lujan , Cano Raquel , Tabares Lucia , Uchitel Osvaldo Daniel 
Published: September 2017

AbstractAcetazolamide (AZ), a molecule frequently used to treat different neurological syndromes, is an inhibitor of the carbonic anhydrase (CA), an enzyme that regulates pH inside and outside cells. We combined fluorescent FM styryl dyes and electrophysiological techniques at ex vivo levator auris longus neuromuscular junctions (NMJs) from mice to investigate the modulation of synaptic transmission and vesicle recycling by AZ. Transmitter release was minimally affected by AZ, as evidenced by evoked and spontaneous end‐plate potential measurements. However, optical evaluation with FM‐styryl dyes of vesicle exocytosis elicited by 50 Hz stimuli showed a strong reduction in fluorescence loss in AZ treated NMJ, an effect that was abolished by bathing the NMJ in Hepes. The remaining dye was quenched by bromophenol, a small molecule capable of diffusing inside vesicles. Furthermore, in transgenic mice expressing Synaptophysin‐pHluorin (SypHy), the fluorescence responses of motor nerve terminals to a 50 Hz train of stimuli was decrease to a 50% of controls in the presence of AZ. Immunohistochemistry experiments to evaluate the state of the Myosin light chain kinase (MLCK), an enzyme involved in vesicle recycling, demonstrated that MLCK phosphorylation was much stronger in the presence than AZ than in its absence in 50 Hz stimulated NMJs. We postulate that AZ, via cytosol acidification and activation of MLCK, shifts synaptic vesicle recycling to a fast (kiss‐and‐run) mode, which changes synaptic performance. These changes may contribute to the therapeutic action reported in many neurological syndromes like ataxia, epilepsy, and migraine.
Mortality and Morbidity After Hartmann’s Procedure Versus Primary Anastomosis Without a Diverting Stoma for Colorectal Perforation: A Nationwide Observational Study
Authors: Tsuchiya Asuka , Yasunaga Hideo , Tsutsumi Yusuke , Matsui Hiroki , Fushimi Kiyohide 
Published: September 2017

AbstractBackgroundThe benefit of primary anastomosis (PA) without a diverting stoma over Hartmann’s procedure (HP) for colorectal perforation remains controversial. We compared postoperative mortality and morbidity between HP and PA without a diverting stoma for colorectal perforation of various etiologies.MethodsUsing the Japanese Diagnosis Procedure Combination database, we extracted data on patients who underwent emergency open laparotomy for colorectal perforation of various etiologies from July 1, 2010 to March 31, 2014. We compared 30‐day mortality, postoperative complication rates, and postoperative critical care interventions between HP and PA groups using propensity score matching, inverse probability of treatment weighting, and instrumental variable analyses to adjust for measured and unmeasured confounding factors.ResultsWe identified 8500 eligible patients (5455 HP and 3045 PA). In the propensity score‐matched model, a significant difference between the HP and PA groups was detected in 30‐day mortality (7.7% vs. 9.6%; risk difference, 1.9%; 95% confidence interval [CI], 0.5–3.4). The inverse probability of treatment weighting showed similar results (8.8% vs. 10.7%; risk difference, 1.9%; 95% CI, 1.0–2.8). In the instrumental variable analysis, the point estimate suggested similar direction to that of the propensity score analyses (risk difference, 4.4%; 95% CI, −3.3 to 12.1). The PA group had significantly higher rates of secondary surgery for complications (4.6% vs. 8.4%; risk difference, 3.8%; 95% CI, 2.5–4.1) and slightly longer duration of postoperative critical care interventions.ConclusionsThis study revealed a significant difference in 30‐day mortality between HP and PA without a diverting stoma.