bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pneumopericardium diagnosis by point‐of‐care ultrasonography
Authors: Bobbia Xavier , Claret Pierre Géraud , Muller Laurent , de La Coussaye Jean Emmanuel 
Published: May 2012

AbstractFocused cardiac ultrasound by the emergency physician has become a fundamental tool to expedite the diagnostic evaluation of the patient at bedside. We report the case of a patient admitted to the emergency department for respiratory distress. He was examined by an emergency physician who performed a bedside echocardiography. Bright spots were seen rapidly moving along the pericardial layer during diastole with comet‐tail artifacts extending across the whole image of the heart and disappearing during systole, suggesting pneumopericardium. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2013
Sphingosine 1‐phosphate‐primed astrocytes enhance differentiation of neuronal progenitor cells
Authors: Spohr Tânia Cristina Leite de Sampaio e , Dezonne Rômulo Sperduto , Nones Jader , dos Santos Souza Cleide , Einicker‐Lamas Marcelo , Gomes Flávia Carvalho Alcântara , Rehen Stevens Kastrup 
Published: May 2012

AbstractSphingosine 1‐phosphate (S1P) is a bioactive signaling lysophospholipid. Effects of S1P on proliferation, survival, migration, and differentiation have already been described; however, its role as a mediator of interactions between neurons and glial cells has been poorly explored. Here we describe effects of S1P, via the activation of its receptors in astrocytes, on the differentiation of neural progenitor cells (NPC) derived from either embryonic stem cells or the developing cerebral cortex. S1P added directly to NPC induced their differentiation, but S1P‐primed astrocytes were able to promote even more pronounced changes in maturation, neurite outgrowth, and arborization in NPC. An increase in laminin by astrocytes was observed after S1P treatment. The effects of S1P‐primed astrocytes on neural precursor cells were abrogated by antibodies against laminin. Together, our data indicate that S1P‐treated astrocytes are able to induce neuronal differentiation of NPC by increasing the levels of laminin. These results implicate S1P signaling pathways as new targets for understanding neuroglial interactions within the central nervous system. © 2012 Wiley Periodicals, Inc.
Different mechanisms underlying changes in excitability of peripheral nerve sensory and motor axons in multiple sclerosis
Authors: Ng Karl , Howells James , Pollard John D. , Burke David 
Published: May 2012

AbstractIntroduction: Subtle involvement of peripheral nerves may occur in multiple sclerosis. Motor excitability studies have suggested upregulation of slow K+ currents, probably secondary to altered motoneuron properties resulting from the central lesion. This study concentrates on sensory axons. Methods: Excitability of median nerve axons at the wrist was studied in 26 patients. Results: Sensory recordings were possible in 22 patients, and reduced superexcitability was the sole abnormality. There was no evidence for changes in membrane potential or demyelination. The decrease was significant in patients taking immunomodulatory therapy. These findings could be reproduced in a computer model by changing the gating of fast K+ channels. Motor axon findings were consistent with previously reported increased slow K+ current. Conclusions: The sensory findings differ from motor findings. They can be explained by a humoral factor, possibly cytokines, which can penetrate the paranode and have been documented to alter the gating of K+ channels. Muscle Nerve, 2013
Photovoltaic module simulation by neural networks using solar spectral distribution
Authors: Piliougine Michel , Elizondo David , Mora‐López Llanos , de‐Cardona Mariano Sidrach‐ 
Published: May 2012

ABSTRACTA novel methodology based on artificial neural networks is proposed as an alternative to algebraic and numerical procedures to determine the I‐V curve of a module under different conditions. Although there are methods that use neural networks for approximating the I‐V curve, this is the first time that the measurement of the spectrum is incorporated as an input. In addition, a suitable selection of the training samples used to build the model is fundamental in order to get an accurate approximation. This is why a training sample selection based on a Kohonen self‐organizing map is performed in this paper instead of a random selection. With the use of this preliminary step, the performance of the network trained with spectral information improves over the one without spectral information. Copyright © 2012 John Wiley & Sons, Ltd.
On the Elastic Modulus of Powders
Authors: Nysaeter Trude O. , Enstad Gisle G. 
Published: May 2012

AbstractFor the design of silos and similar equipment for storage, handling and processing of particulate materials, a thorough understanding of the mechanical behaviour of powders is of great importance. Whereas strength properties of powders have been investigated by many workers, the elastic behaviour at small deformations has been much less in focus. In that respect, a simple preliminary theory of uniaxial elasticity has been derived for particles, based on a simple system of spherical and monosized particles of a homogenous and elastically isotropic material. The equation σ = Epϵel2 gives the relationship between stress, elastic modulus and elastic deformation for the unloading of a given powder at a specific consolidation stress/ compression level. Comparisons with experimental results of real powders in a uniaxial tester show surprisingly good agreement in many cases. The equation seems to describe the elasticity of powders fairly well, although it is only a preliminary derivation based on simple considerations.
Fractional exhaled nitric oxide in healthy non‐asthmatic 7‐year olds and prenatal exposure to polycyclic aromatic hydrocarbons: Nested regression analysis
Authors: Jedrychowski Wieslaw , Maugeri Umberto , Mroz Elzbieta , Flak Elzbieta , Rembiasz Maria , Jacek Ryszard , Sowa Agata 
Published: May 2012

AbstractThe main goal of the study was to assess possible association between transplacental exposure to genotoxic PAH compounds assessed by the cord blood PAH–DNA adducts and fractional exhaled nitric oxide (FeNO) measured in healthy non‐asthmatic children at the age of 7 years. The subjects included the subsample of 89 children who took part in the ongoing population based birth cohort study in Krakow and attended FeNO testing. The effect of transplacental PAH exposure was adjusted for potential confounders, such as maternal allergy and children's specific atopy to common domestic allergens.ResultsFeNO values were significantly elevated in children with higher prenatal PAH exposure (gmean = 7.7 ppb; 95% CI: 5.8–10.2 ppb) compared with those at low exposure level (gmean = 3.8 ppb; 95% CI: 2.3–6.3) (P = 0.011). Children with maternal allergy had also significantly higher mean FeNO values (gmean = 13.7 ppb, 95% CI: 8.8–21.4 ppb) compared with the subjects whose mothers denied allergy (gmean = 5.6 ppb, 95% CI: 4.3–7.3 ppb) (P = 0.012). Similarly, FeNO values in atopic children were higher (gmean = 11.2 ppb; 95% CI: 3.8–32.8 ppb) than in non‐atopic individuals (gmean = 6.0 ppb; 95% CI: 4.7–7.7 ppb, P = 0.079). The results of the nested multivariable linear regression analysis showed that both maternal allergy and sensitization of children to domestic aeroallergens jointly explained 10.4% of FeNO variance, however, the additional 10.9% was determined by prenatal PAH exposure.ConclusionFeNO is more than a marker useful for screening atopy or symptomatic bronchial inflammation and may also be a proxy for cytokine deregulation and “allergic response” phenotype possibly established in fetal period due to transplacental PAH exposure. Preliminary results of our study should encourage more studies on intrauterine PAH exposure and later respiratory symptoms. Pediatr Pulmonol. 2012. 47:1131–1139. © 2012 Wiley Periodicals, Inc.
Efficacy of methylprednisolone in children with severe community acquired pneumonia
Authors: Nagy Bela , Gaspar Imre , Papp Agnes , Bene Zsolt , Nagy Bela , Voko Zoltan , Balla Gyorgy 
Published: May 2012

AbstractBackgroundThe clinical value of adjuvant corticosteroid treatment in community‐acquired pneumonia (CAP) seemed to be controversial in adults, and even less data are available on the use of corticosteroids in children with CAP.Materials and MethodsIn this study, we investigated the efficacy of a 5‐day adjuvant methylprednisolone therapy to imipenem in 29 children with severe CAP. In parallel, 30 subjects with the same disease were treated with imipenem and placebo, and the two study groups were compared based on the different parameters of the primary and secondary end points. The primary end points were the duration of fever, the levels of white blood cells (WBC) and high sensitive C‐reactive protein (hsCRP). Secondary end points were the length of hospital stay, and the number of severe complications with or without surgical interventions.ResultsThe additive methylprednisolone treatment significantly reduced the duration of fever with 2.5 days, the WBC counts (P = 0.014), the hsCRP levels showing a 48.7% decrease, and the length of hospital stay with 5.2 days versus the placebo group. Moreover, patients treated on imipenem alone had twice more complications and four times more invasive interventions compared to those on the combined therapy.ConclusionsThe 5‐day methylprednisolone therapy with imipenem was found effective in children having severe CAP. However, trials with larger cohorts are needed to study further beneficial effects of corticosteroids in children with CAP. Pediatr Pulmonol. 2013; 48:168–175. © 2012 Wiley Periodicals, Inc.
An optimal design for patient‐specific templates for pedicle spine screws placement
Authors: Ferrari V. , Parchi P. , Condino S. , Carbone M. , Baluganti A. , Ferrari M. , Mosca F. , Lisanti M. 
Published: May 2012

AbstractBackgroundCurrently, pedicle screws are positioned using a free‐hand technique or under fluoroscopic guidance, with error in the range 10–40%, depending on the skill of the surgeon.MethodsAfter spine CT acquisition, each vertebra is segmented and the surgeon plans screw positioning in a virtual environment, then the template is designed around the chosen trajectories. This design is based on surgical and mechanical considerations to obtain an optimal solution to guarantee template stability, simple positioning and minimized intervention invasiveness. In vitro evaluation on synthetic spine models and ex vivo animal tests on porcine specimens were performed, with the insertion of 28 Kirschner wires.ResultsDuring the in vitro tests, all the surgeons rendered positive evaluations regarding the device and considered template placement to be easy. Ex vivo tests were evaluated by CT examination, which showed that 96.5% of the Kirschner wires had been correctly inserted.ConclusionsThe proposed solution is a promising, simple, highly precise, low‐cost solution to safely performing posterior stabilization. Such a solution would be of interest even in hospitals in which a few spine interventions are performed per year, and for which it is not reasonable to purchase the equipment required for robotic or navigated approaches. Copyright © 2012 John Wiley & Sons, Ltd.
Model Predictive Control approach for guidance of spacecraft rendezvous and proximity maneuvering
Authors: Di Cairano S. , Park H. , Kolmanovsky I. 
Published: May 2012

SUMMARYTraditionally, rendezvous and proximity maneuvers have been performed using open‐loop maneuver planning techniques and ad hoc error corrections. In this paper, a Model Predictive Control (MPC) approach is applied to spacecraft rendezvous and proximity maneuvering problems in the orbital plane. We demonstrate that various constraints arising in these maneuvers can be effectively handled with the MPC approach. These include constraints on thrust magnitude, constraints on spacecraft positioning within Line‐of‐Sight cone while approaching the docking port on a target platform, and constraints on approach velocity to match the velocity of the docking port. The two cases of a nonrotating and a rotating (tumbling) platform are treated separately, and trajectories are evaluated in terms of maneuver time and fuel consumption. For the case when the platform is not rotating and the docking port position is fixed with respect to the chosen frame, an explicit offline solution of the MPC optimization problem is shown to be possible; this explicit solution has a form of a piecewise affine control law suitable for online implementation without an on‐board optimizer. In the case of a fast rotating platform, it is, however, shown that the prediction of the platform rotation is necessary to successfully accomplish the maneuvers and to reduce fuel consumption. Finally, the proposed approach is applied to debris avoidance maneuvers with the debris in the spacecraft rendezvous path. The significance of this paper is in demonstrating that Model Predictive Control can be an effective feedback control approach to satisfy various maneuver requirements, reduce fuel consumption, and provide robustness to disturbances. Copyright © 2012 John Wiley & Sons, Ltd.
Do SEII Electrons Really Degrade SEM Image Quality?
Authors: Bernstein Gary H. , Carter Andrew D. , Joy David C. 
Published: May 2012

SummaryGenerally, in scanning electron microscopy (SEM) imaging, it is desirable that a high‐resolution image be composed mainly of those secondary electrons (SEs) generated by the primary electron beam, denoted SEI. However, in conventional SEM imaging, other, often unwanted, signal components consisting of backscattered electrons (BSEs), and their associated SEs, denoted SEII, are present; these signal components contribute a random background signal that degrades contrast, and therefore signal‐to‐noise ratio and resolution. Ideally, the highest resolution SEM image would consist only of the SEI component. In SEMs that use conventional pinhole lenses and their associated Everhart–Thornley detectors, the image is composed of several components, including SEI, SEII, and some BSE, depending on the geometry of the detector. Modern snorkel lens systems eliminate the BSEs, but not the SEIIs. We present a microfabricated diaphragm for minimizing the unwanted SEII signal components. We present evidence of improved imaging using a microlithographically generated pattern of Au, about 500 nm thick, that blocks most of the undesired signal components, leaving an image composed mostly of SEIs. We refer to this structure as a “spatial backscatter diaphragm.” SCANNING 35:1‐6, 2013. © 2012 Wiley Periodicals, Inc.
Chemotherapy and molecular‐targeted treatment for unresectable hepatic metastases: a Japanese perspective
Authors: Shimada Yasuhiro 
Published: May 2012

AbstractLiver metastasis from colorectal cancer has become a common disease associated with the increase of primary colorectal cancer in Japan. The standard treatment for resectable liver metastases is still complete liver resection. Recent advances in systemic chemotherapy have introduced another strategy, i.e., conversion chemotherapy, for patients with initially diagnosed unresectable liver metastases. The conversion rate after neo‐adjuvant chemotherapy is increasing with multidisciplinary approaches. Long‐term clinical data have not been established yet. Indications for liver resection after neo‐adjuvant chemotherapy; optimal chemotherapy regimens; and histological changes in the normal liver are important research issues for the future.
The Ethnic-Civic Dichotomy and the Explanation of National Self-Understanding
Authors: Jayet Cyril 
Published: May 2012

AbstractIn his paper Ethnicity as Cognition (2006), Rogers Brubaker held that cognitive psychology can enrich the understanding of the practices of categorisation that underpins ethnicity, nationhood and race. I shall argue that the philosophical debate concerning the different types of explanation in social sciences – the explanations based on reasons and the explanations based on causal mechanisms – can throw some light on this issue. To analyse beliefs requires use of both approaches. It can be shown with the classical opposition between an ethnic and a civic conception of national belonging which derives from a reason-based approach. The causal mechanism approach underlying cognitive psychology can offer alternative models accounting for national self-understanding, notably the prototype model of categorisation. I confront empirically these two theories – the ethnic civic dichotomy and the prototype model – using theisspdata from 2003 and evidence the advantages and shortcomings of each theory.
Methionine restriction affects the phenotypic and transcriptional response of rainbow trout (Oncorhynchus mykiss) to carbohydrate-enriched diets
Authors: Craig Paul M. , Moon Thomas W. 
Published: May 2012

Mammalian studies report that methionine restriction (MR) as a dietary regimen extends life span, delays the onset of age-related diseases and enhances fat oxidation in obese subjects with metabolic syndromes. However, the underlying cellular signalling pathways are poorly understood. Rainbow trout (Oncorhynchus mykiss) is a glucose-intolerant species, providing an excellent model for the study of carbohydrate metabolism. MR diets in combination with 12 % (+/ − ) and 22 % (+/ − ) carbohydrate-rich meals were fed to rainbow trout for a period of 8 weeks and phenotypic and transcript expression changes in the liver and white muscle were assessed. Fish fed MR diets, irrespective of carbohydrate load, were shown to abolish the glucose-intolerant phenotype 6 h post-feeding. There was a distinct switch in glucose and glycogen content in the liver of fish fed MR diets, with a significantly higher concentration of glycogen, suggesting reduced glycolytic capacity. Transcriptional responses to MR demonstrated decreased expression of hepatic fatty acid synthase, sterol regulatory binding protein 1, PPARγ coactivator 1-α and PPARα, indicative of a reduction in thede novosynthesis of fatty acids and cholesterol, and a potential decrease in hepatic fat oxidative capacity. Muscle adenylate charge was depressed under MR, and increased expression of AMP-activated protein kinase α1 was detected, indicative of reduced energy availability. Total DNA methylation showed that carbohydrate load, rather than MR, dictated hypomethylation of genomic DNA. This is the first study which demonstrates that MR can abolish a glucose-intolerant phenotype in trout, and identifies trout as a suitable model for studying metabolic syndromes.
Detection of recurrent and primary acquired cholesteatoma with echo-planar diffusion-weighted magnetic resonance imaging
Authors: Evlice A , Tarkan Ö , Kiroğlu M , Biçakci K , Özdemir S , Tuncer Ü , Çekiç E 
Published: May 2012

AbstractObjective:To evaluate the diagnostic value of echo-planar diffusion-weighted magnetic resonance imaging in pre-operative detection of suspected primary acquired, residual and/or recurrent cholesteatoma.Materials and methods:Fifty-eight chronic otitis media patients with suspected cholesteatoma were thus evaluated two weeks pre-operatively, and divided into group one (41 patients, no previous surgery, suspected primary acquired cholesteatoma) and group two (17 patients, previous surgery, scheduled ‘second-look’ or revision surgery for suspected residual or recurrent cholesteatoma). Patients' operative, histopathology and radiological findings were compared.Results:Cholesteatoma was found in 63 per cent of group one patients and 58 per cent of group two patients at surgery. Histopathological examination of surgical specimens indicated that imaging accurately predicted the presence or absence of cholesteatoma in 90 per cent of group one (37/41; 23 true positives, 14 true negatives) and 76 per cent of group two (13/17; seven true positives, six true negatives). Three patients in both groups were false negative diagnoses and one patient in both groups was a false positive. The sensitivity, specificity, and positive and negative predictive values of echo-planar diffusion-weighted magnetic resonance imaging of cholesteatoma were respectively 88, 93, 95 and 82 per cent in group one and 70, 85, 87 and 66 per cent in group two.Conclusion:Echo-planar diffusion-weighted magnetic resonance imaging is a valuable technique with high sensitivity and specificity for cholesteatoma imaging.
A Semi-Markov Multiple State Model for Reverse Mortgage Terminations
Authors: Ji Min , Hardy Mary , Li Johnny Siu-Hang 
Published: May 2012

AbstractReverse mortgages provide a mechanism for seniors to release the equity that has been built up in their home. At termination, the mortgagors are usually guaranteed to owe no more than the value of their property. The value of the reverse mortgage guarantee is heavily dependent on the maturity or termination date, which is uncertain. In this paper, we model reverse mortgage terminations using a semi-Markov multiple state model which incorporates three different modes of exit: death, entrance into a long-term care facility, and voluntary prepayment. We apply the proposed model specifically to develop the valuation formulas for roll-up mortgages in the UK and Home Equity Conversion Mortgages (HECMs) in the USA. We examine the significance of each mode of termination by valuing the contracts allowing progressively for each mode. On the basis of our model and assumptions, we find that both health related terminations and voluntary (non-health related) terminations significantly impact the contract value. In addition we analyze the premium structure for US reverse mortgage insurance, and demonstrate that premiums appear to be too high for some borrowers, and substantial cross-subsidies may result.
Lattice cluster theory of associating telechelic polymers. III. Order parameter and average degree of self-assembly, transition temperature, and specific heat
Authors: Dudowicz Jacek , Freed Karl F. , Douglas Jack F. 
Published: May 2012

The lattice cluster theory of strongly interacting, structured polymer fluids is applied to determine the thermodynamic properties of solutions of telechelic polymers that may associate through bifunctional end groups. Hence, this model represents a significant albeit natural extension of a diverse array of prior popular equilibrium polymerization models in which structureless “bead” monomers associate into chain-like clusters under equilibrium conditions. In particular, the thermodynamic description of the self-assembly of linear telechelic chains in small molecule solvents (initiated in Paper II) is systematically extended through calculations of the order parameter Φ and average degree ⟨N⟩ of self-assembly, the self-assembly transition temperature Tp, and the specific heat CV of solutions of telechelic molecules. Special focus is placed on examining how molecular and thermodynamic parameters, such as the solution composition ϕ, temperature T, microscopic interaction energies (εs and ε), and length M of individual telechelic chains, influence the computed thermodynamic quantities that are commonly used to characterize self-assembling systems.