bluuebunny/crossref_metadata_2025 huggingface dataset:
Percutaneous Extraction of ePTFE‐Coated ICD Leads: A Single Center Comparative Experience
Authors: KOHUT ANDREW R. , GRAMMES JON , SCHULZE CHRISTOPHER M. , AL‐BATAINEH MOHAMMAD , YESENOSKY GEORGE A. , HORROW JAY C. , KUTALEK STEVEN P.
Published: January 2013

Background

Percutaneous extraction of standard implantable cardioverter‐defibrillator leads is often complicated by ingrowth of fibrotic tissue into the shocking coils. Leads with GORE™ expanded polytetrafluoroethylene (ePTFE) coating (W. L. Gore & Associates, Inc., Newark, DE, USA) designed to inhibit fibrosis are in use, but clinical data regarding their extraction are lacking. The study's purpose was to examine the feasibility, efficacy, and safety of percutaneous extraction involving defibrillator leads coated with ePTFE.

Methods

We analyzed our database to identify all percutaneously extracted leads with ePTFE‐coated shocking coils. Lead and procedure characteristics were compared to a cohort of noncoated leads of similar implant duration.

Results

One hundred fifty‐six leads were extracted from 145 patients; 57 ePTFE‐coated leads, with a mean implant duration of 621 days, were extracted and compared to 99 noncoated leads, with a mean implant duration of 763 days (P = 0.0641). Mean extraction time was 5 minutes for coated leads versus 9.75 minutes for noncoated leads (P = 0.0001). Extraction time of less than 1 minute was more frequent with coated leads (61% vs 35%, P = 0.0025). Adjunct extraction tools were required less frequently with coated leads than noncoated leads (39% vs 63%, P = 0.0071). There was no fibrosis where ePTFE covered the shocking coils. Alternatively, 23 of 99 (23%) noncoated leads demonstrated fibrosis adherent to the shock coil. There were no procedure‐related complications in either group.

Conclusions

Compared to noncoated leads, ePTFE‐coated leads are associated with shorter extraction times and are less likely to require extraction tools for removal. The difference is likely related to the absence of fibrosis over the ePTFE‐coated high‐energy coils.
Acquired Protein Energy Malnutrition in Glutaric Acidemia
Authors: Ma Liqiao , Savory Stephanie , Agim Nnenna G.
Published: January 2013

We report a case of acquired protein energy malnutrition with associated zinc deficiency in an 18‐month‐old boy with type 1 glutaric acidemia. Physical examination findings included generalized nonpitting edema, widespread desquamative plaques, and sparse hair with a reddish tinge. Laboratory abnormalities included low levels of zinc, albumin, alkaline phosphatase, and iron. A review of skin manifestations of nutritional deficiencies, specifically kwashiorkor, is presented, as well as the relatively new entity called acrodermatitis dysmetabolica.
Diverging Racial Trends in Neonatal Infantile Hemangioma Diagnoses, 1979–2006
Authors: Amrock Stephen M. , Weitzman Michael
Published: January 2013

Nationally representative historical trends in neonatal infantile hemangioma (IH) diagnosis have not been previously assessed. Using the National Hospital Discharge Survey (NHDS), trends in IH diagnoses were assessed according to race and sex. Findings confirmed prior research that female and white newborns are more likely to be diagnosed with IH, and a statistically significant increase in IH diagnoses was observed in white, but not in nonwhite, infants.
Conversational Implicatures (and How to Spot Them)
Authors: Blome‐Tillmann Michael
Published: January 2013

In everyday conversations we often convey information that goes above and beyond what we strictly speaking say: exaggeration and irony are obvious examples. H.P. Grice introduced the technical notion of a conversational implicature in systematizing the phenomenon of meaning one thing by saying something else. In introducing the notion, Grice drew a line between what is said, which he understood as being closely related to the conventional meaning of the words uttered, and what is conversationally implicated, which can be inferred from the fact that an utterance has been made in context. Since Grice’s seminal work, conversational implicatures have become one of the major research areas in pragmatics. This article introduces the notion of a conversational implicature, discusses some of the key issues that lie at the heart of the recent debate, and explicates tests that allow us to reliably distinguish between semantic entailments and conventional implicatures on the one hand and conversational implicatures on the other.
Metabolism in orange fruits is driven by photooxidative stress in the leaves
Authors: Poiroux‐Gonord Florine , Santini Jérémie , Fanciullino Anne‐Laure , Lopez‐Lauri Félicie , Giannettini Jean , Sallanon Huguette , Berti Liliane , Urban Laurent
Published: January 2013

In plants, stress signals propagate to trigger distant responses and thus stress acclimation in non‐exposed organs. We tested here the hypothesis that leaves submitted to photooxidative stress may influence the metabolism of nearby fruits and thus quality criteria. Leaves of orange trees (Citrus sinensis (L.) Osbeck cv. ‘Navelate’) were acclimated to shade for 1 week and then submitted to full (FL) and medium light (ML) conditions. As expected, photoinhibition was detected in leaves of both FL and ML treatments as revealed by stress indicators (Fv/Fm, Performance Index) for at least 99 h after treatments. In the fruits near the stressed leaves, we then determined the activities of enzymes related to oxidative stress, superoxide dismutase, catalase and the enzymes of the ascorbate (AA)/glutathione cycle, as well as the contents in sugars, organic acids and carotenoids. Ascorbate peroxidase and monodehydroascorbate reductase activities in the pulp of fruits were dramatically higher in both treatments when compared to the control. AA and total sugars were not affected by the photooxidative stress. However, the FL treatment resulted in a 16% increase in total organic acids, with succinic acid being the major contributor, a shift towards less glucose + fructose and more sucrose, and a 15% increase in total carotenoids, with cis‐violaxanthin being the major contributor. Our observations strongly suggest the existence of a signal generated in leaves in consequence of photooxidative stress, transmitted to nearby fruits. Exploiting such a signal by agronomic means promises exciting perspectives in managing quality criteria in fruits accumulating carotenoids.
What price fairness when security is at stake? Police legitimacy in South Africa
Authors: Bradford Ben , Huq Aziz , Jackson Jonathan , Roberts Benjamin
Published: January 2013

The legitimacy of legal authorities – particularly the police – is central to the state's ability to function in a normatively justifiable and effective manner. Studies, mostly conducted in the US and UK, regularly find that procedural justice is the most important antecedent of police legitimacy, with judgments about other aspects of police behavior – notably, about effectiveness – appearing less relevant. But this idea has received only sporadic testing in less cohesive societies where social order is more tenuous, resources to sustain it scarcer, and the position of the police is less secure. This paper considers whether the link between process fairness and legitimacy holds in the challenging context of present day South Africa. In a high crime and socially divided society, do people still emphasize procedural fairness or are they more interested in instrumental effectiveness? How is the legitimacy of the police influenced by the wider problems faced by the South African state? We find procedural fairness judgments play a key role, but also that South Africans place greater emphasis on police effectiveness (and concerns about crime). Police legitimacy is, furthermore, associated with citizens' judgments about the wider success and trustworthiness of the state.
SCALE ECONOMIES OF THE FRANCHISED BUSES AND FERRIES OF HONG KONG, 1948–1998
Authors: Lai Lawrence W.C. , Chau K.W. , Cheung Polycarp Alvin C.W.
Published: January 2013

The privatization of state transport operators has been driven by empirical discoveries in transport economic research of the constant or even diseconomies of scale of these operators. With reference to public records and official statistics, this paper is an initial attempt to examine the scale economies of and output relationship between major bus and ferry operators in Hong Kong during the period 1948–1998. The two franchised bus and two franchised ferry companies each experienced unique scale effects during different periods and correlated with each other in terms of production. The paper will also discuss the possible reasons for this phenomenon and policy concerns related to this finding.
Religion and Suicide in Patients with Mental Illness or Cancer
Authors: Panczak Radoslaw , Spoerri Adrian , Zwahlen Marcel , Bopp Matthias , Gutzwiller Felix , Egger Matthias
Published: January 2013

In Switzerland, the highest rates of suicide are observed in persons without religious affiliation and the lowest in Catholics, with Protestants in an intermediate position. We examined whether this association was modified by concomitant psychiatric diagnoses or malignancies, based on 6,909 suicides (ICD‐10 codes X60‐X84) recorded in 3.69 million adult residents 2001–2008. Suicides were related to mental illness or cancer if codes F or C, respectively, were mentioned on the death certificate. The protective effect of religion was substantially stronger if a diagnosis of cancer was mentioned on the death certificate and weaker if a mental illness was mentioned.
Dynamical Analysis of the MicroRNA – Mediated Protein Translation Process
Authors: Nikolova Elena , Jordanov Ivan , Vitanov Nikolay
Published: January 2013

Mathematical modelling of kinetic processes with different time scales allows a reduction of the governing equations using quasi-steady-state approximations (QSSA). A QSSA theorem is applied to a modified mathematical model of the microRNA-mediated protein translation process. By an appropriate normalized procedure the system of seven nonlinear ordinary differential equations is rewritten in a form suitable for model reduction. In accordance with the terminology of the QSSA theorem, it is established that two of the protein concentrations are "fast varying", such that the corresponding kinetic equations form an attached system. The other four concentrations are "slow varying", and form a degenerate system. Another variable appears to be a constant. Analytical solutions, related to the steady-state values of the fast varying concentrations and the slow varying ones, are derived and interpreted as restrictions on the regulatory role of microRNAs on the protein translation dynamics.
Improved Thermal Response in Encapsulated Phase Change Materials by Nanotube Attachment on Encapsulating Solid
Authors: Barney I. T. , Ganguli S. , Roy A. K. , Mukhopadhyay S. M.
Published: January 2013

This paper demonstrates greatly improved specific power (W/g) for encapsulated phase change materials (EPCM) as a result of modified interface morphology. Carbon nanotubes are strongly attached to the interior walls of the graphitic foam encapsulation. Microstructure analysis using scanning electron microscopy (SEM) indicates that the wax infiltrates into the carbon nanotubes (CNT) forest and creates an intimate contact with increased interfacial area between the two phases. Specific power has been calculated by measuring thermal response times of the phase change materials using a custom system. The carbon nanotubes increase the specific power of the encapsulated phase change materials by about 27% during heating and over 146% during the more important stage of latent heat storage. Moreover, SEM images of the interface after repeated thermal cycling indicate that the presence of CNT may also improve durability of the EPCM by preventing interfacial gaps and maintaining improved contact between the graphite and PCM phases.
Pool Boiling Heat Transfer Enhancement Through Nanostructures on Silicon Microchannels
Authors: Yao Z. , Lu Y.-W. , Kandlikar S. G.
Published: January 2013

Uniform silicon nanowires (SiNW) were successfully fabricated on the top, bottom, and sidewall surfaces of silicon microchannels by using a two-step electroless etching process. Different microchannel patterns with the channel width from 100 to 300 μm were first fabricated in a 10 mm × 10 mm silicon chip and then covered by SiNW with an average height of 10–20 μm. The effects of the microchannel geometry, micro/nano-hierarchical structures on pool boiling were studied and the bubble dynamics on different sample surfaces were compared. It was found that the combination of the micro/nanostructures promoted microbubble emission boiling under moderate heat fluxes, and yielded superior boiling heat transfer performance. At given wall superheats, the maximum heat flux of the microchannel with SiNW was improved by 120% over the microchannel-only surface, and more than 400% over a plain silicon surface. These results provide a new insight into the boiling mechanism for micro/nano-hierarchical structures and demonstrate their potential in improving pool boiling performance for microchannels.
Nanocarrier–Cell Surface Adhesive and Hydrodynamic Interactions: Ligand–Receptor Bond Sensitivity Study
Authors: Uma B. , Radhakrishnan R. , Eckmann D. M. , Ayyaswamy P. S.
Published: January 2013

A hybrid approach combining fluctuating hydrodynamics with generalized Langevin dynamics is employed to study the motion of a neutrally buoyant nanocarrier in an incompressible Newtonian stationary fluid medium. Both hydrodynamic interactions and adhesive interactions are included, as are different receptor–ligand bond constants relevant to medical applications. A direct numerical simulation adopting an arbitrary Lagrangian–Eulerian based finite element method is employed for the simulation. The flow around the particle and its motion are fully resolved. The temperatures of the particle associated with the various degrees of freedom satisfy the equipartition theorem. The potential of mean force (or free energy density) along a specified reaction coordinate for the harmonic (spring) interactions between the antibody and antigen is evaluated for two different bond constants. The numerical evaluations show excellent comparison with analytical results. This temporal multiscale modeling of hydrodynamic and microscopic interactions mediating nanocarrier motion and adhesion has important implications for designing nanocarriers for vascular targeted drug delivery.
Study of Insulating Properties of Alkanethiol Self-Assembled Monolayers Formed Under Prolonged Incubation Using Electrochemical Impedance Spectroscopy
Authors: Agonafer Damena D. , Chainani Edward , Oruc Muhammed E. , Lee Ki Sung , Shannon Mark A.
Published: January 2013

The electrochemical interfacial properties of a well-ordered self-assembled monolayer (SAM) of 1-undecanethiol (UDT) on evaporated gold surface have been investigated by electrochemical impedance spectroscopy (EIS) in electrolytes without a redox couple. Using a constant-phase element (CPE) series resistance model, prolonged incubation times (up to 120 h) show decreasing monolayer capacitance approaching the theoretical value for 1-undecanethiol. Using the CPE exponent α as a measure of ideality, it was found that the monolayer approaches an ideal dielectric (α = 0.992) under prolonged incubation, which is attributed to the reduction of pinholes and defects in the monolayer during coalescence and annealing of SAM chains. The SAMs behave as insulators until a critical potential, Vc, is exceeded in both cathodic and anodic regimes, where electrolyte ions are believed to penetrate the monolayers. Using a Randles circuit model for these cases, the variation of the capacitance and charge transfer resistance with applied dc potential shows decreased permeability to ionic species with prolonged incubation time. The EIS data show that UDT (methylene chain length n = 10), incubated for 120 h, forms a monolayer whose critical voltage range extends from −0.3 to 0.5 V versus Ag/AgCl, previously attained only for alkanethiol at n = 15. At low frequencies where ion diffusion occurs, almost pure capacitive phase (−89 deg) was attained with lengthy incubation.
Micro-Optical Initiation of Nanoenergetic Materials Using a Temporally Tailored Variable-Pulse-Width Laser
Authors: Slipchenko Mikhail N. , Moody Clint E. , Miller Joseph D. , Roy Sukesh , Gord James R. , Meyer Terrence R.
Published: January 2013

Nanoenergetic materials can provide a significant enhancement in the rate of energy release as compared with microscale materials. The energy-release rate is strongly dependent not only on the primary particle size but also on the level of agglomeration, which is of particular interest for the inclusion of nanoenergetics in practical systems where agglomeration is desired or difficult to avoid. Unlike studies of nanoparticles or nanometer-size aggregates, which can be conducted with ultrafast or nanosecond lasers assuming uniform heating, microscale aggregates of nanoparticles are more sensitive to the thermophysical time scale of the heating process. To allow control over the rate of energy deposition during laser initiation studies, a custom, temporally tailored, continuously variable-pulse-width (VPW) laser was employed for radiative heating of nanoenergetic materials. The laser consisted of a continuous-wave master oscillator, which could be sliced into desired pulses, and a chain of amplifiers to reach high peak power. The slicer allowed control over the time profile of the pulses via the combination of an arbitrary waveform generator and acousto-optic modulator (AOM). The effects of utilizing flat-top or ramped laser pulses with durations from 100 ns to 150 μs and energies up to 20 mJ at 1064 nm were investigated, along with a broad range of heating rates for single particles or nanoparticle aggregates up to 100-μm diameter. In combination with an optical microscope, laser heating of aggregates consisting of 70-nm diameter Al nanoparticles in a Teflon matrix showed significant dependence on the heating profile due to the sensitivity of nanoenergetic materials to heating rate. The ability to control the temporal pulse-intensity profile leads to greater control over the effects of ablative heating and the resulting shockwave propagation. Hence, flexible laser-pulse profiles allow the investigation of energetic properties for a wide size range of metal/metal-oxide nanoparticles, aggregates, and composites.
Experimental and Numerical Validation of a Wind Gust Facility
Authors: Volpe Raffaele , Da Silva Arthur , Ferrand Valérie , Le Moyne Luis
Published: January 2013

The study of a vehicle moving through a lateral wind gust has always been a difficult task due to the difficulties in granting the right similitude. The facility proposed by Ryan and Dominy has been one of the best options to carry it out. In this approach, a double wind tunnel is used to send a lateral moving gust on a stationary model. Using this idea as a starting point, the ISAE has built a dedicated test bench for lateral wind studies on transient conditions. Experimental work has been carried out by means of time-resolved PIV, aiming at studying the unsteady interpenetration of the two flows coming from each wind tunnel. Meanwhile, a 3D CFD model based on URANS was set up, faithfully reproducing the double wind tunnel. Both the experimental and numerical results are compared, and the evolution of the reproduced wind gust is discussed. Conclusions are finally determined about the validity of this kind of test bench for ground vehicle applications.
Coupled Computational Fluid Dynamic and Finite Element Multiphase Modeling of Laser Weld Bead Geometry Formation and Joint Strengths
Authors: Marimuthu S. , Eghlio R. M. , Pinkerton A. J. , Li L.
Published: January 2013

Laser welding is used extensively in industry for joining various materials in the assembly of components and structures. Localized melting followed by rapid cooling results in the formation of a weld bead and generation of residual stress. Selection of the appropriate combination of input parameters and understanding their effects is important to achieve the required weld quality with a smooth welding surface. In the present work, a sequentially coupled thermo-structural multiphase analysis was carried out with the objectives of predicting the effect of laser parameters on the change in surface topology of the weld bead and its subsequent effect on structural properties. The work shows that the laser welding parameters strongly affect the weld bead shape, which eventually affects the weld quality. A net shaped weld bead demonstrates better performance in terms of stress distribution and distortion than other weld bead shapes. The numerical simulation results were compared with the experimental observations performed on a mild steel sheet using a fibre laser and the results are in good agreement in terms of weld bead cross-sectional profile and strength.
Variability of Computational Fluid Dynamics Solutions for Pressure and Flow in a Giant Aneurysm: The ASME 2012 Summer Bioengineering Conference CFD Challenge
Authors: Steinman David A. , Hoi Yiemeng , Fahy Paul , Morris Liam , Walsh Michael T. , Aristokleous Nicolas , Anayiotos Andreas S. , Papaharilaou Yannis , Arzani Amirhossein , Shadden Shawn C. , Berg Philipp , Janiga Gábor , Bols Joris , Segers Patrick , Bressloff Neil W. , Cibis Merih , Gijsen Frank H. , Cito Salvatore , Pallarés Jordi , Browne Leonard D. , Costelloe Jennifer A. , Lynch Adrian G. , Degroote Joris , Vierendeels Jan , Fu Wenyu , Qiao Aike , Hodis Simona , Kallmes David F. , Kalsi Hardeep , Long Quan , Kheyfets Vitaly O. , Finol Ender A. , Kono Kenichi , Malek Adel M. , Lauric Alexandra , Menon Prahlad G. , Pekkan Kerem , Esmaily Moghadam Mahdi , Marsden Alison L. , Oshima Marie , Katagiri Kengo , Peiffer Véronique , Mohamied Yumnah , Sherwin Spencer J. , Schaller Jens , Goubergrits Leonid , Usera Gabriel , Mendina Mariana , Valen-Sendstad Kristian , Habets Damiaan F. , Xiang Jianping , Meng Hui , Yu Yue , Karniadakis George E. , Shaffer Nicholas , Loth Francis
Published: January 2013

Stimulated by a recent controversy regarding pressure drops predicted in a giant aneurysm with a proximal stenosis, the present study sought to assess variability in the prediction of pressures and flow by a wide variety of research groups. In phase I, lumen geometry, flow rates, and fluid properties were specified, leaving each research group to choose their solver, discretization, and solution strategies. Variability was assessed by having each group interpolate their results onto a standardized mesh and centerline. For phase II, a physical model of the geometry was constructed, from which pressure and flow rates were measured. Groups repeated their simulations using a geometry reconstructed from a micro-computed tomography (CT) scan of the physical model with the measured flow rates and fluid properties. Phase I results from 25 groups demonstrated remarkable consistency in the pressure patterns, with the majority predicting peak systolic pressure drops within 8% of each other. Aneurysm sac flow patterns were more variable with only a few groups reporting peak systolic flow instabilities owing to their use of high temporal resolutions. Variability for phase II was comparable, and the median predicted pressure drops were within a few millimeters of mercury of the measured values but only after accounting for submillimeter errors in the reconstruction of the life-sized flow model from micro-CT. In summary, pressure can be predicted with consistency by CFD across a wide range of solvers and solution strategies, but this may not hold true for specific flow patterns or derived quantities. Future challenges are needed and should focus on hemodynamic quantities thought to be of clinical interest.
50 Years of Computer Simulation of the Human Thermoregulatory System
Authors: Hensley Daniel W. , Mark Andrew E. , Abella Jayvee R. , Netscher George M. , Wissler Eugene H. , Diller Kenneth R.
Published: January 2013

This paper presents an updated and augmented version of the Wissler human thermoregulation model that has been developed continuously over the past 50 years. The existing Fortran code is translated into C with extensive embedded commentary. A graphical user interface (GUI) has been developed in Python to facilitate convenient user designation of input and output variables and formatting of data presentation. Use of the code with the GUI is described and demonstrated. New physiological elements were added to the model to represent the hands and feet, including the unique vascular structures adapted for heat transfer associated with glabrous skin. The heat transfer function and efficacy of glabrous skin is unique within the entire body based on the capacity for a very high rate of blood perfusion and the novel capability for dynamic regulation of blood flow. The model was applied to quantify the absolute and relative contributions of glabrous skin flow to thermoregulation for varying levels of blood perfusion. The model also was used to demonstrate how the unique features of glabrous skin blood flow may be recruited to implement thermal therapeutic procedures. We have developed proprietary methods to manipulate the control of glabrous skin blood flow in conjunction with therapeutic devices and simulated the effect of these methods with the model.
Subject-Specific Analysis of Joint Contact Mechanics: Application to the Study of Osteoarthritis and Surgical Planning
Authors: Henak Corinne R. , Anderson Andrew E. , Weiss Jeffrey A.
Published: January 2013

Advances in computational mechanics, constitutive modeling, and techniques for subject-specific modeling have opened the door to patient-specific simulation of the relationships between joint mechanics and osteoarthritis (OA), as well as patient-specific preoperative planning. This article reviews the application of computational biomechanics to the simulation of joint contact mechanics as relevant to the study of OA. This review begins with background regarding OA and the mechanical causes of OA in the context of simulations of joint mechanics. The broad range of technical considerations in creating validated subject-specific whole joint models is discussed. The types of computational models available for the study of joint mechanics are reviewed. The types of constitutive models that are available for articular cartilage are reviewed, with special attention to choosing an appropriate constitutive model for the application at hand. Issues related to model generation are discussed, including acquisition of model geometry from volumetric image data and specific considerations for acquisition of computed tomography and magnetic resonance imaging data. Approaches to model validation are reviewed. The areas of parametric analysis, factorial design, and probabilistic analysis are reviewed in the context of simulations of joint contact mechanics. Following the review of technical considerations, the article details insights that have been obtained from computational models of joint mechanics for normal joints; patient populations; the study of specific aspects of joint mechanics relevant to OA, such as congruency and instability; and preoperative planning. Finally, future directions for research and application are summarized.
Regional Structural and Biomechanical Alterations of the Ovine Main Pulmonary Artery During Postnatal Growth
Authors: Fata Bahar , Carruthers Christopher A. , Gibson Gregory , Watkins Simon C. , Gottlieb Danielle , Mayer John E. , Sacks Michael S.
Published: January 2013

The engineering foundation for novel approaches for the repair of congenital defects that involve the main pulmonary artery (PA) must rest on an understanding of changes in the structure-function relationship that occur during postnatal maturation. In the present study, we quantified the postnatal growth patterns in structural and biomechanical behavior in the ovine PA in the juvenile and adult stages. The biaxial mechanical properties and collagen and elastin fiber architecture were studied in four regions of the PA wall, with the collagen recruitment of the medial region analyzed using a custom biaxial mechanical-multiphoton microscopy system. Circumferential residual strain was also quantified at the sinotubular junction and bifurcation locations, which delimit the PA. The PA wall demonstrated significant mechanical anisotropy, except in the posterior region where it was nearly isotropic. Overall, we observed only moderate changes in regional mechanical properties with growth. We did observe that the medial and lateral locations experience a moderate increase in anisotropy. There was an average of about 24% circumferential residual stain present at the luminal surface in the juvenile stage that decreased to 16% in the adult stage with a significant decrease at the bifurcation, implying that the PA wall remodels toward the bifurcation with growth. There were no measurable changes in collagen and elastin content of the tunica media with growth. On average, the collagen fiber recruited more rapidly with strain in the adult compared to the juvenile. Interestingly, the PA thickness remained constant with growth. When this fact is combined with the observed stable overall mechanical behavior and increase in vessel diameter with growth, a simple Laplace Law wall stress estimate suggests an increase in effective PA wall stress with postnatal maturation. This observation is contrary to the accepted theory of maintenance of homeostatic stress levels in the regulation of vascular function and suggests alternative mechanisms regulate postnatal somatic growth. Understanding the underlying mechanisms, incorporating important structural features during growth, will help to improve our understanding of congenital defects of the PA and lay the basis for functional duplication in their repair and replacement.
Simulation of Impact Tests With Hard, Soft and Liquid Filled Missiles on Reinforced Concrete Structures
Authors: Heckötter Christian , Sievers Jürgen
Published: January 2013

Vital parts of nuclear facilities are commonly protected by reinforced concrete (rc-) structures. In order to assess the barrier effectiveness of these structures, different internal and external loads have to be considered. Among others, external missile impacts, for instance due to an airplane crash, are assumed to be relevant loading cases. In this context, impacts of nondeformable (“hard”), deformable (“soft”) as well as liquid filled (“wet”) missiles are considered. Major rc-target failure mechanisms are global bending, punching and perforation. This paper presents simulations with the computer program AUTODYN (ANSYS INC., 2010, ANSYS AUTODYN, Version 13.0 & Theory Manual) on intermediate- and large-scale impact experiments dealing with the aforementioned failure mechanisms. Missile velocities are in the range of 110 to 250 m/s. In particular, two different intermediate scale test series are considered. One test deals with predominant punching failure and perforation of a rc-slab (target) hit by a hard missile. Further, bending vibration of slabs impacted by soft missiles is analyzed, whereupon the influence of liquid infill on loading and target response is pointed out. Finally, a large scaled test with combined bending and punching failure of a rc-slab due to soft missile impact is considered. Results of numerical simulation and tests are compared. It is found, that the used concret material model developed by Riedel, Hiermaier, and Thoma (RHT) (Riedel, 2004, “Beton Unter Dynamischen Lasten: Meso-Und Makromechanische Modelle Und Ihre Parameter, Fraunhofer–Ernst-Mach-Institut, Freiburg/Br., ISBN 3-8167-6340-5) is suitable to reproduce the responses of rc-structures subjected to various kinds of impact conditions. Sensitivities of simulation results on modeling parameters are discussed.
InP Nanowire Array Solar Cells Achieving 13.8% Efficiency by Exceeding the Ray Optics Limit
Authors: Wallentin Jesper , Anttu Nicklas , Asoli Damir , Huffman Maria , Åberg Ingvar , Magnusson Martin H. , Siefer Gerald , Fuss-Kailuweit Peter , Dimroth Frank , Witzigmann Bernd , Xu H. Q. , Samuelson Lars , Deppert Knut , Borgström Magnus T.
Published: January 2013

Improving Nanowire Photovoltaics

In principle, solar cells based on arrays of nanowires made from compound inorganic semiconductors, such as indium phosphide (InP), should decrease materials and fabrication costs compared with planar junctions. In practice, device efficiencies tend to be low because of poor light absorption and increased rates of unproductive charge recombination in the surface region.

Wallentin
et al.

(p.
1057
, published online 17 January) now report that arrays of p-i-n InP nanowires (that switch from positive to negative doping), grown to millimeter lengths, can be optimized by varying the nanowire diameter and length of the n-doped segment. Efficiencies as high as 13.8% were achieved, which are comparable to the best planar InP photovoltaics.
Quantitative Magneto-Mechanical Detection and Control of the Barkhausen Effect
Authors: Burgess J. A. J. , Fraser A. E. , Sani F. Fani , Vick D. , Hauer B. D. , Davis J. P. , Freeman M. R.
Published: January 2013

Controlling Magnetic Noise

Ferromagnetic materials contain a number of magnetic domains, with individual domains switching stochastically as the field strength is increased. As magnetic memory elements shrink in size, it is important to understand, and ultimately control, this magnetic noise. Using a magnetic vortex core integrated with a nanomechanical torsion balance,

Burgess
et al.

(p.
1051
, published online 17 January) created a two-dimensional map of the magnetic potential within the sample with nanoscale resolution. Moreover, introducing geometric defects (dimples) in the sample allowed the magnetization to be stabilized.
Genome-Wide Quantitative Enhancer Activity Maps Identified by STARR-seq
Authors: Arnold Cosmas D. , Gerlach Daniel , Stelzer Christoph , Boryń Łukasz M. , Rath Martina , Stark Alexander
Published: January 2013

The Regulatory Genome

Multicellular organisms contain a variety of cell types that are morphologically and functionally distinct even though they typically contain the same genomic DNA. Differences stem from differential gene expression. Gene regulatory genomic regions (enhancers) are well studied, yet despite major efforts, such as Encode and modEncode, the number of enhancers in animal genomes and their genomic positions, cell-type specificity, and strengths are largely unknown.

Arnold
et al.

(p.
1074
, published online 17 January) report a method, termed STARR-seq, that measures the strength of enhancers genome-wide, giving insight into the organization of the regulatory genome.
Myoelectrical Activity and Muscle Morphology in a Rat Model of Myofascial Trigger Points Induced by Blunt Trauma to the Vastus Medialis
Authors: Huang Qiang-Min , Ye Gang , Zhao Zhen-Yan , Lv Jiao-Jiao , Tang Li
Published: January 2013

Objectives

To explore myoelectrical activity and muscle morphology of myofascial trigger points (MTrPs) in an injury model of rats.

Methods

A total of 24 male SD rats were randomly divided into a control group (group A) and model group (group B). A blunt striking injury and eccentric exercise were applied to the vastus medialis (VM) of rats in group B for 8 weeks. Later, the palpable taut band (TB), local twitch response, myoelectrical activities and morphology in the two groups were examined.

Results

An average of 2.5 (30/12) palpable TBs were detected in the VM in group B compared with none in group A. The MTrPs had two types of abnormal potential. Their amplitudes were significantly higher than those in the control group (p<0.01) but their durations showed no significant differences. A series of reflex contractions appeared in groups A and B in response to external stimulation to the ear. Their amplitude and duration in group B were significantly lower than those in group A. A series of lower fibrillation potentials repeatedly occurred in model MTrPs in group B. The morphology of MTrPs showed abnormal muscle fibres with large round or ellipse shapes in cross-section and enlarged tapering shapes in longitudinal section.

Conclusions

Active MTrPs can be provoked by repeated blunt injury. Active MTrPs are a group of muscle fibres with abnormal shapes and abnormal myoelectrical potentials. External stimulation provokes low-voltage responses in MTrPs, which is different from the response of normal muscle fibres.
Current state of knowledge on neuroendocrine small bowel tumours: non-systematic review of the literature based on one case
Authors: Simion Nicolae Irinel , Muntean Valentin , Fabian Ovidiu
Published: January 2013

More than 60% of neuroendocrine tumours, also called carcinoids, are localised within the gastrointestinal tract. Small bowel neuroendocrine tumours have been diagnosed with increasing frequency over the past 35 years, being the second most frequent tumours of the small intestine. Ileal neuroendocrine tumours diagnosis is late because patients have non-specific symptoms. We have proposed to illustrate as an example the case of a patient, and on its basis, to make a brief review of the literature on small bowel neuroendocrine tumours, resuming several recent changes in the field, concerning classification criteria of these tumours and new recommendations and current advances in diagnosis and treatment. This patient came to our emergency department with a complete bowel obstruction, along with a 2-year history of peristaltic abdominal pain, vomits and diarrhoea episodes. During emergency laparotomy, an ileal stricture was observed, that showed to be a neuroendocrine tumour of the small bowel.
Where is the culprit? A case of acromegaly that defied the management algorithm
Authors: Tamban Celito A , Sandoval Mark Anthony S , Lantion-Ang Frances Lina
Published: January 2013

A 30-year-old Filipino man presented with a 11-year history of coarse facial features and progressive enlargement of hands and feet. Initial work-up revealed elevated insulin-like growth factor-1 and non-suppressible growth hormone level after 75 g glucose challenge test. Initial cranial MRI performed in the year 2010 showed absence of pituitary adenoma. The patient was lost to follow-up. He again consulted in the year 2011 and a repeat cranial MRI and a dedicated pituitary MRI were performed and both did not reveal any pituitary mass. Further investigation included chest and abdominal CT scan, both of which did not show any neoplasm. At present, there has been no practice guideline on the management of acromegalic patients on whom the identifiable source cannot be found. The patient was given the option to undergo surgical exploration of the pituitary gland or medical treatment with somatostatin analogues. He decided to undergo surgery but has not given consent for the procedure.
Gastric band erosion, infection and migration causing jejunal obstruction
Authors: Salar Omer , Waraich Naseem , Singh Rajeev , Awan Altaf
Published: January 2013

Complications of laparoscopic adjustable gastric bands (LAGB) are well documented and may include migration, erosion, slippage, infection, pouch dilatation and, rarely, gastric perforation. We describe a rare case involving three such complications simultaneously, namely, gastric erosion, infection and migration through the pylorus-causing proximal jejunal obstruction. As LAGB is now the commonest performed bariatric procedure for the treatment of morbid obesity, we encourage the practising surgeon to be vigilant of these rare but potentially life-threatening complications.
Gallbladder volvulus: a case of mimicry
Authors: Vedanayagam Maria Sangeetha , Nikolopoulos Ioannis , Janakan Gnananandan , El-Gaddal Ahmed
Published: January 2013

Torsion of the gallbladder resulting in a volvulus is a rare clinical finding that poses a diagnostic challenge preoperatively to both surgeons and radiologists. It is thought to occur secondary to a redundant mesentery where rotation of the gallbladder occurs along the axis of the cystic duct and cystic artery. Gallbladder volvulus commonly presents as acute cholecystitis and is rarely diagnosed preoperatively. An early emergency laparoscopic cholecystectomy is the preferred treatment. Early consideration of this diagnosis enables prompt surgical intervention and quick postoperative recovery periods.
Clubbing, cyanosis and a new diagnosis of atrial septal defect in a parturient: a straightforward diagnosis of Eisenmenger syndrome?
Authors: Butcher Charles , Plyman Carla , Hughes Marina , Walker Fiona
Published: January 2013

A parturient required emergency admission to intensive care following a major postpartum haemorrhage. She was hypovolaemic, hypoxic and cyanosed and was also noted to have digital clubbing. A transthoracic echo showed a large atrial septal defect (ASD) with right heart dilation and possible anomalous pulmonary venous drainage. Eisenmenger syndrome was diagnosed with cyanosis due to shunt reversal at atrial level (right atrium to left), as a consequence of an elevated pulmonary vascular resistance from chronically increased pulmonary blood flow. After a full initial recovery, she was referred to a specialist grown-up congenital heart disease unit for further investigation. Cardiac MRI confirmed an ASD but showed that the cause of the cyanosis was anatomical in origin. An elongated Eustachian valve was diverting desaturated inferior venacaval blood across the intra-atrial septum into the left atrium. Her congenital heart defect was therefore amenable to corrective surgery.
Prevention of fall-related injuries in 7-year-old to 12-year-old children: a cluster randomised controlled trial
Authors: Nauta Joske , Knol Dirk L , Adriaensens Lize , Klein Wolt Karin , van Mechelen Willem , Verhagen Evert A L M
Published: January 2013

Introduction

To counteract the recently observed increase in forearm fractures in children worldwide, an educational programme to improve fall skills was developed. In this 8-week programme children learned basic martial arts falling techniques in their physical education classes. In this study, the effectiveness of this educational programme to improve fall skills was evaluated.

Methods

A cluster randomised controlled trial was conducted in 33 primary schools. The intervention group received the educational programme to improve falling skills during their physical education (PE) classes whereas the control group received their regular PE curriculum. At baseline (October 2009) and follow-up (May 2010), a questionnaire was completed by the children about their physical activity behaviours. Furthermore, fall-related injuries were registered continuously during an entire school-year.

Results

A total of 36 incident injuries was reported in the intervention group, equalling an injury incidence density (IID) of 0.14 fall-related injuries per 1000 h of physical activity (95% CI 0.09 to 0.18). In contrast, 96 injuries were reported by the control group corresponding to an IID of 0.26 (95% CI 0.21 to 0.32). However, because intracluster correlation was high (ICC=0.46), differences in injury incidence were not statistically significant. When activity level was taken into account, a trend was shown suggesting that the ‘falling is a sport’ programme was effective in decreasing falling-related injury risk, but only in the least active children.

Discussion and conclusion

Although results did not reach significance because of strong clustering effects, a trend was found suggesting that a school-based educational programme to improve falling skills may be more beneficial for the prevention of falling-related injuries in children with low levels of habitual physical activity.
Movie making as a cognitive distraction for paediatric patients receiving radiotherapy treatment: qualitative interview study
Authors: Shrimpton Bradley J M , Willis David J , Tongs Cáthal D , Rolfo Aldo G
Published: January 2013

Objectives

To establish the outcomes achieved by using an innovative movie-making programme designed to reduce fear of radiotherapy among paediatric patients.

Design

Qualitative descriptive evaluation based on semistructured, qualitative interviews with purposeful sampling and thematic analysis.

Setting

Tertiary Cancer Centre.

Participants

20 parents of paediatric patients who had produced a movie of their radiation therapy experience and were in a follow-up phase of cancer management.

Results

Participants attributed a broad range of outcomes to the movie-making program. These included that the programme had helped reduce anxiety and distress exhibited by paediatric patients and contributed to a willingness to receive treatment. Other outcomes were that the completed movies had been used in school reintegration and for maintaining social connections.

Conclusions

Allowing children to create a video of their experience of radiotherapy provided a range of benefits to paediatric patients that varied according to their needs. For some patients, movie-making offered a valuable medium for overcoming fear of the unknown as well as increasing understanding of treatment processes. For others, the development of a personalised video offered an important cognitive/attentional distraction through engaging with an age-appropriate activity. Together these outcomes helped children maintain self-control and a positive outlook.
Recognising the importance of ‘family time-out’ in consultations: an exploratory qualitative study
Authors: Korfage Ida J , Audrey Suzanne , Hak Tony , Blazeby Jane M , Abel Julian , Campbell Rona
Published: January 2013

Objectives

Patients are often accompanied by family or companions during consultations, but little is known about how this might influence the process. We explored how the presence of a companion in a consultation contributes to communication and the decision-making process.

Design

Observational study.

Setting

A teaching hospital and a district general hospital in south-west England.

Participants

31 patients and their physicians were observed during consultations in which decisions to undergo palliative chemotherapy were made. Each patient was accompanied by at least one companion.

Outcome measures

Communication patterns between physicians, patients and companions.

Results

In addition to standard patient/physician interactions, patients and companions were often found to discuss medical information and exchange opinions between themselves without the physician actively participating. We called these instances ‘family time-out’. On the occasion of disagreement between patients and companions about preferred treatment options, physicians and patients were able to agree the decision while acknowledging the differences in opinion.

Conclusions

Instances of ‘family time-out’ may contribute to better consultation outcomes because they are understood and supported by the patient's social system. This study highlights the potentially important role of exchanges between patients and companions during consultations and how physicians may benefit from observation of such exchanges. We recommend testing the value of making space for family time-out during consultations. Also, we recommend further study into the medical ethics of family time-out. While the focus here is on palliative chemotherapy, this finding has implications for other consultations, particularly those involving difficult treatment decisions.