bluuebunny/crossref_metadata_2025_split huggingface dataset:
VEGF modulates synaptic activity in the developing spinal cord
Authors: Guérit Sylvaine , Allain Anne‐Emilie , Léon Céline , Cazenave William , Ferrara Napoleone , Branchereau Pascal , Bikfalvi Andréas 
Published: April 2014

ABSTRACTAlthough it has been documented that the nervous and the vascular systems share numerous analogies and are closely intermingled during development and pathological processes, interactions between the two systems are still poorly described. In this study, we investigated whether vascular endothelial growth factor (VEGF), which is a key regulator of vascular development, also modulates neuronal developmental processes. We report that VEGF enhances the gamma‐aminobutyric acid (GABA)/glycinergic but not glutamatergic synaptic activity in embryonic spinal motoneurons (MNs), without affecting MNs excitability. In response to VEGF, the frequency of these synaptic events but not their amplitude was increased. Blocking endogenous VEGF led to an opposite effect by decreasing frequency of synaptic events. We found that this effect occurred specifically at early developmental stages (E13.5 and E15.5) and vanished at the prenatal stage E17.5. Furthermore, VEGF was able to increase vesicular inhibitory amino acid transporter density at the MN membrane. Inhibition of single VEGF receptors did not modify electrophysiological parameters indicating receptor combinations or an alternative pathway. Altogether, our findings identify VEGF as a modulator of the neuronal activity during synapse formation and highlight a new ontogenic role for this angiogenic factor in the nervous system. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 74: 1110–1122, 2014
Does your species have memory? Analyzing capture–recapture data with memory models
Authors: Cole Diana J. , Morgan Byron J. T. , McCrea Rachel S. , Pradel Roger , Gimenez Olivier , Choquet Remi 
Published: April 2014

AbstractWe examine memory models for multisite capture–recapture data. This is an important topic, as animals may exhibit behavior that is more complex than simple first‐order Markov movement between sites, when it is necessary to devise and fit appropriate models to data. We consider the Arnason–Schwarz model for multisite capture–recapture data, which incorporates just first‐order Markov movement, and also two alternative models that allow for memory, the Brownie model and the Pradel model. We use simulation to compare two alternative tests which may be undertaken to determine whether models for multisite capture–recapture data need to incorporate memory. Increasing the complexity of models runs the risk of introducing parameters that cannot be estimated, irrespective of how much data are collected, a feature which is known as parameter redundancy. Rouan et al. (JABES, 2009, pp 338–355) suggest a constraint that may be applied to overcome parameter redundancy when it is present in multisite memory models. For this case, we apply symbolic methods to derive a simpler constraint, which allows more parameters to be estimated, and give general results not limited to a particular configuration. We also consider the effect sparse data can have on parameter redundancy and recommend minimum sample sizes. Memory models for multisite capture–recapture data can be highly complex and difficult to fit to data. We emphasize the importance of a structured approach to modeling such data, by considering a priori which parameters can be estimated, which constraints are needed in order for estimation to take place, and how much data need to be collected. We also give guidance on the amount of data needed to use two alternative families of tests for whether models for multisite capture–recapture data need to incorporate memory.
Intermolecular Interactions in Fluorinated Tetraarylporphyrins: An Experimental and Theoretical Study
Authors: Soman Rahul , Sujatha Subramaniam , De Susmita , Rojisha Vallyanga Chalil , Parameswaran Pattiyil , Varghese Babu , Arunkumar Chellaiah 
Published: May 2014

AbstractCrystallographic studies of the fluorinated tetraarylporphyrin 5,10,15,20‐tetrakis(2′,3′,5′,6′‐tetrafluoro‐N,N‐dimethyl‐4‐anilinyl)porphyrin and its metal complexes [MTF4DMAP; M = 2H·2H2O, 1; NiII·THF, 2; CuII·5H2O, 3; and ZnII·(THF)2, 4; THF = tetrahydrofuran] are reported. To analyse the weak intermolecular interactions, we have used a combination of energy decomposition analysis and Hirshfeld surface analysis, which allowed us to elucidate the nature of various close contacts. The energy decomposition analysis shows that dispersive interactions involving fluorine atoms significantly contribute to the stabilizing intermolecular interactions. Cooperative weak interactions such as C–F···H/C/F, C–H···π and H···H are responsible for the formation and stabilization of the supramolecular self assemblies.
Hierarchical Self‐Assembly of Luminescent EuIII Complexes on Silicon
Authors: Misztal Kasjan , Tudisco Cristina , Sartori Andrea , Malicka Joanna M. , Castelli Riccardo , Condorelli Guglielmo G. , Dalcanale Enrico 
Published: April 2014

AbstractWe have combined the metal‐coordinating features of phenanthroline with the remarkable complexing properties of tetraphosphonate (Tiiii) cavitands towards N‐methylammonium salts with the aim of assembling novel luminescent ternary complexes. The formation of such complexes was first tested in solution: the charged sarcosine derivative 1, bearing a phenanthroline moiety, was complexed by the cavitand Tiiii‐A, followed by coordination of EuIII–tris(β‐diketonate) complex 2. The occurrence of the self‐assembly has been proven by NMR spectroscopy, mass spectrometry and photophysical measurements. The transfer of this binding protocol to the surface showed the complete orthogonality of these interactions, as verified by control experiments on complexation‐inactive surfaces. The formation of the ternary complexes on the silicon surface was monitored by means of X‐ray photoelectron spectroscopy and luminescence spectroscopy. The emission properties of the silicon‐bound Si‐Tiiii‐B·1·2 and the corresponding ternary complex Tiiii‐A·1·2 in solution are similar, which indicates that the transfer of the self‐assembly process onto silicon does not significantly perturb the EuIII coordination environment. The self‐assembly protocol illustrated here can be extended to a wide variety of lanthanide ions and can be implemented for applications in sensing, bioimaging and optoelectronic devices.
Evidence of biogeomorphic patterning in a low‐relief karst landscape
Authors: Watts Adam C. , Watts Danielle L. , Cohen Matthew J. , Heffernan James B. , McLaughlin Daniel L. , Martin Jonathan B. , Kaplan David A. , Osborne Todd Z. , Kobziar Leda N. 
Published: May 2014

ABSTRACTPatterned landscapes are often evidence of biotic control on geomorphic processes, emerging in response to coupled ecosystem processes acting at different spatial scales. Self‐reinforcing processes at local scales expand patches, while self‐inhibiting processes, operating at a distance, impose limits to expansion. In Big Cypress National Preserve (BICY) in southwest Florida, isolated forested wetland depressions (cypress domes) appear to be evenly distributed within a mosaic of short‐hydroperiod marshes and pine uplands. To test the hypothesis that the apparent patterning is regular, we characterized frequency distributions and spatial patterns of vegetation communities, surface and bedrock elevation, and soil properties (thickness and phosphorus content). Nearest neighbor distances indicate strongly significant wetland spatial overdispersion, and bedrock elevations exhibited periodic spatial autocorrelation; both observations are consistent with regular patterning. Bedrock elevations and soil P were clearly bimodal, suggesting strong positive feedbacks on wetland patch development. Soil‐surface elevations exhibited weaker bimodality, indicating smoothing of surface morphology by some combination of sediment transport, mineral reprecipitation, and organic matter production. Significant negative autocorrelation of bedrock elevations at scales similar to wetland spacing suggest the presence of distal negative feedbacks on patch expansion. These findings support the inference of regular patterning, and are consistent with the presence of local positive feedbacks among hydroperiod, vegetation productivity and bedrock dissolution. These processes are ultimately constrained by distal negative feedbacks, potentially induced by landscape scale limitations on the water volume required to enable this biogeomorphic mechanism. Copyright © 2014 John Wiley & Sons, Ltd.
Heterogeneous Aging Within PEMFC Stacks
Authors: Chatillon Y. , Bonnet C. , Lapicque F. 
Published: May 2014

AbstractEvaluation of PEM fuel cell aging occurring in various operating conditions is usually conducted in single cell configuration for which various electrochemical methods can be used. Aging phenomena in stack is often investigated either in a global manner or by basic measurements of variables, e.g. individual cell voltages. This paper presents the results of aging investigation of three‐cell stacks using crossed linked electrochemical methods giving access to the time variations of ohmic and charge transfer resistance of the three cathodes, as well as the electrochemical surface area and the fuel crossover over more than 1,000 h at 0.3 A cm–2 upon air humidification. Consistency between the various methods employed was discussed and demonstrated. In addition to the case of a stack formed by three sane cells, the case of a stack comprising a defective cell – previously aged under oxidative conditions – placed between two sane MEAs was investigated: the pre‐ageing of this cell was shown to slightly accelerate the aging under long‐term operation. Besides, it was observed that in both stacks, the back cell – i.e. located far from the stack inlet and outlet – suffered much more from the long‐term run than the two other cells.
Using the Multiple SEA Method to Synthesize Pt/Carbon Xerogel Electrocatalysts for PEMFC Applications
Authors: Zubiaur A. , Chatenet M. , Maillard F. , Lambert S. D. , Pirard J.‐P. , Job N. 
Published: May 2014

AbstractPt/carbon xerogel (CX) catalysts were synthesized by the multiple strong electrostatic adsorption (SEA) method. This method consists of the impregnation of a carbon support (here, a CX) by a solution containing hexachloroplatinic acid (H2PtCl6). The impregnation pH is precisely chosen to maximize the ion/support interactions. The Pt precursor solution can be re‐used so as to avoid Pt waste during the process. Five catalysts with increasing Pt weight percentage were synthesized by multiple impregnation (from one to five times), and were characterized by transmission electron microscopy, X‐ray diffraction, and CO stripping. The specific activity of the Pt particles for the oxygen reduction reaction (ORR) was measured in liquid electrolyte with a rotating disk electrode system. The Pt particles are ca. 2.5 nm in diameter and display electroactive specific surface areas of ca. 95 cm2 gPt–1. The five Pt/CX catalysts present the same specific activity for the ORR: for all the catalysts, the specific activity equals ca. 0.05 mA cm–2Pt at 0.85 V versus NHE and 0.01 mA cm–2Pt at 0.9 V versus NHE.
Evaluating the Effectiveness of Using Flexography Printing for Manufacturing Catalyst‐Coated Membranes for Fuel Cells
Authors: Bois C. , Dumont P. J. J. , Blayo A. , Vincent R. , Nayoze C. , Chaussy D. 
Published: May 2014

AbstractThis study is an evaluation of the effectiveness of the flexography printing process for manufacturing catalyst‐coated membranes (CCMs) for use in proton exchange membrane fuel cells (PEMFCs). Flexography is a maskless and continuous process that is used in large‐scale production with water‐based inks to reduce the cost of production of PEMFC components. Unfortunately, water has undesirable effects on the Nafion® membrane: water wets the membrane surface poorly and causes the membrane to bulge outwards significantly. Membrane printability was improved by pre‐treating membrane samples by water immersion for short periods (<2 min). This pre‐treatment was used to control the membrane deformation before printing to limit the impact of the ink transfer. Water and ink drop deposition experiments were performed to estimate the liquid‐air‐Nafion® apparent contact angle and the locally induced membrane deformation. Despite the short immersion times used in the tests, the immersion pre‐treatment appeared to induce structural modifications that enhanced both the membrane wettability and the dimensional stability. Flexography printability tests were performed on these treated membranes and showed that the dimensional instability of the Nafion® membrane was the critical parameter for limiting the ink transfer. The immersion pre‐treatment improved the printability of the Nafion® membranes, which were used to fabricate cathodes that were tested in an operational fuel cell.
Transoral robotic assisted resection of the parapharyngeal space
Authors: Mendelsohn Abie H. 
Published: May 2014

AbstractBackgroundPreliminary case series have reported clinical feasibility and safety of a transoral minimally invasive technique to approach parapharyngeal space masses. With the assistance of the surgical robotic system, tumors within the parapharyngeal space can now be excised safely without neck incisions. A detailed technical description is included.MethodsAfter developing compressive symptoms from a parapharyngeal space lipomatous tumor, the patient was referred by his primary otolaryngologist because of poor open surgical access to the nasopharyngeal component of the tumor.ResultsTransoral robotic assisted resection of a 54‐ × 46‐mm parapharyngeal space mass was performed, utilizing 97 minutes of robotic surgical time. Pictorial demonstration of the robotic resection is provided.ConclusionParapharyngeal space tumors have traditionally been approached via transcervical skin incisions, typically including blunt dissection from tactile feedback. The transoral robotic approach offers magnified 3D visualization of the parapharyngeal space that allows for complete and safe resection. © 2014 Wiley Periodicals, Inc. Head Neck 37: 273‐280, 2015
Influence of surgical margins on local recurrence in T1/T2 oral squamous cell carcinoma
Authors: Barry Conor P. , Ahmed Ferhan , Rogers Simon N. , Lowe Derek , Bekiroglu Fazilet , Brown James S. , Shaw Richard J. 
Published: May 2014

AbstractBackgroundThe purpose of this study was to explore the significance of resection margin status on local recurrence and survival for early (T1/T2) oral cancer and to determine if the significance of the resection margin varies with the biological aggression of the tumor as determined by pN status.MethodsThe influence of resection margin size and local recurrence for 295 patients with pT1/T2 oral cavity squamous cell carcinomas (SCCs) treated by primary surgery, including neck dissection, between 1998 and 2010 was analyzed.ResultsOverall, there was a trend toward increased local recurrence with close or involved margins. When stratified according to nodal status, there was no relationship between margin size and local recurrence for the pN0 group.ConclusionThe size of the resection margin does not seem to influence local control in stage I/II oral cancer. With future advances in preoperative neck staging, this data may help plan personalized therapy in head and neck cancer. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1176–1180, 2015
Cognitive impairment in temporal lobe epilepsy: Role of online and offline processing of single cell information
Authors: Titiz A. S. , Mahoney J. M. , Testorf M. E. , Holmes G. L. , Scott R. C. 
Published: May 2014

ABSTRACTCognitive impairment is a common comorbidity in temporal lobe epilepsy (TLE) and is often considered more detrimental to quality of life than seizures. While it has been previously shown that the encoding of memory during behavior is impaired in the pilocarpine model of TLE in rats, how this information is consolidated during the subsequent sleep period remains unknown. In this study, we first report marked deficits in spatial memory performance and severe cell loss in the CA1 layer of the hippocampus lower spatial coherence of firing in TLE rats. We then present the first evidence that the reactivation of behavior‐driven patterns of activity of CA1 place cells in the hippocampus is intact in TLE rats. Using a template‐matching method, we discovered that real‐time (3–5 s) reactivation structure was intact in TLE rats. Furthermore, we estimated the entropy rate of short time scale (∼250 ms) bursting activity using block entropies and found that significant, extended temporal correlations exist in both TLE and control rats. Fitting a first‐order Markov Chain model to these bursting time series, we found that long sequences derived from behavior were significantly enriched in the Markov model over corresponding models fit on randomized data confirming the presence of replay in shorter time scales. We propose that the persistent consolidation of poor spatial information in both real time and during bursting activity may contribute to memory impairments in TLE rats. © 2014 Wiley Periodicals, Inc.
The effect of maternal body mass index on fetal growth: Use of individualized growth assessment and two‐level linear modeling
Authors: Canavan Timothy P. , Deter Russell L. 
Published: May 2014

ABSTRACTPurposeTo determine the effect of maternal body mass index on fetal growth using individualized growth assessment and two‐level linear modeling.MethodsA retrospective review of biometry in the second and third trimesters from 246 normal, term singleton fetuses was performed. Four to eight biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur diaphysis length (FDL) measurements per fetus were available and used to determine second‐trimester growth rates. Expected third‐trimester size trajectories were generated from these data and Percent Deviations [%Dev = ((observed − expected)/expected) × 100] were calculated. Two‐level linear modeling was used to determine %Dev slopes and the effect of body mass index (BMI) on these slopes. Relationships between individual second‐ and third‐trimester slopes and BMI were evaluated using linear regression.ResultsLinear regression analysis of second‐trimester growth indicated no significant relationships between the fetal growth rate and the BMI in the second trimester [R2 (adj): 0.0% to 1.0% except AC in one subgroup (5.6%)]. Regression analysis did not indicate a significant relationship (adj R2: 0%–0.2%) between BMI and third‐trimester %Dev slopes for any anatomic parameter. Two‐level statistical modeling showed no effect of BMI on BPD, AC, or FDL growth and only a moderate effect on the HC growth in the third trimester.ConclusionsOur findings indicate that the maternal BMI does not have an effect on fetal growth in either the second or the third trimester as determined with individualized growth assessment. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 42:456–464, 2014
Comparison of techniques for the isolation of volatiles from cashew apple juice
Authors: Sampaio Karina L , Biasoto Aline C T , Da Silva Maria Aparecida A P 
Published: April 2014

AbstractBACKGROUNDThe aim of this study was to compare the performance of the following techniques on the isolation of volatiles of importance for the aroma/flavor of fresh cashew apple juice: dynamic headspace analysis using PorapakQ® as trap, solvent extraction with and without further concentration of the isolate, and solid‐phase microextraction (fiber DVB/CAR/PDMS).RESULTSA total of 181 compounds were identified, from which 44 were esters, 20 terpenes, 19 alcohols, 17 hydrocarbons, 15 ketones, 14 aldehydes, among others. Sensory evaluation of the gas chromatography effluents revealed esters (n = 24) and terpenes (n = 10) as the most important aroma compounds.CONCLUSIONThe four techniques were efficient in isolating esters, a chemical class of high impact in the cashew aroma/flavor. However, the dynamic headspace methodology produced an isolate in which the analytes were in greater concentration, which facilitates their identification (gas chromatography–mass spectrometry) and sensory evaluation in the chromatographic effluents. Solvent extraction (dichloromethane) without further concentration of the isolate was the most efficient methodology for the isolation of terpenes. Because these two techniques also isolated in greater concentration the volatiles from other chemical classes important to the cashew aroma, such as aldehydes and alcohols, they were considered the most advantageous for the study of cashew aroma/flavor. © 2014 Society of Chemical Industry
Partitioned analysis of flexible multibody systems using filtered linear finite element deformational modes
Authors: González José A. , Abascal Ramón , Park K.C. 
Published: April 2014

SUMMARYThis work presents a partitioned finite element formulation for flexible multibody systems, based on the floating frame (FF) approach, under the assumption of small deformations but arbitrarily large rotations of the bodies. In classical FF of reference methods, deformational modes are normally computed by modal analysis. In this approach, free‐floating modes are eliminated from the linear model using projection techniques and substituted by a complete set of non‐linear finite rotations. In this way, all deformational modes are retained, and no modal selection is needed. The main difference between this work and a classical FF of reference formulation is an algebraic separation of pure deformational modes from rigid‐body motions. The proposed methodology presents the following advantages. First, the position and orientation of the FF has no restriction and can be freely located in the body with identical results. Second, the formulation uses only the linear finite element matrices of a classical vibration problem; hence, they can be easily obtained from linear FEM packages. Third, no selection of modes is needed, all deformational modes are retained through the filtering process. And finally, thanks to the use of localized Lagrangian multipliers (LLM), a partitioned system is obtained that can be solved iteratively and in a distributed manner by available scalable solvers. Copyright © 2014 John Wiley & Sons, Ltd.
A level set approach for topology optimization with local stress constraints
Authors: Emmendoerfer Hélio , Fancello Eduardo Alberto 
Published: April 2014

SUMMARYThe purpose of this work is to present a level set‐based approach for the structural topology optimization problem of mass minimization submitted to local stress constraints. The main contributions are threefold. First, the inclusion of local stress constraints by means of an augmented Lagrangian approach within the level set context. Second, the proposition of a constraint procedure that accounts for a continuous activation/deactivation of a finite number of local stress constraints during the optimization sequence. Finally, the proposition of a logarithmic scaling of the level set normal velocity as an additional regularization technique in order to improve the minimization sequence. A set of benchmark tests in two dimensions achieving successful numerical results assesses the good behavior of the proposed method. In these examples, it is verified that the algorithm is able to identify stress concentrations and drive the design to a feasible local minimum. Copyright © 2014 John Wiley & Sons, Ltd.