WorldWideScience

Sample records for leading-edge bluntness effects

  1. A Reduced-Complexity Investigation of Blunt Leading-Edge Separation Motivated by UCAV Aerodynamics

    Science.gov (United States)

    Luckring, James M.; Boelens, Okko J.

    2015-01-01

    A reduced complexity investigation for blunt-leading-edge vortical separation has been undertaken. The overall approach is to design the fundamental work in such a way so that it relates to the aerodynamics of a more complex Uninhabited Combat Air Vehicle (UCAV) concept known as SACCON. Some of the challenges associated with both the vehicle-class aerodynamics and the fundamental vortical flows are reviewed, and principles from a hierarchical complexity approach are used to relate flow fundamentals to system-level interests. The work is part of roughly 6-year research program on blunt-leading-edge separation pertinent to UCAVs, and was conducted under the NATO Science and Technology Organization, Applied Vehicle Technology panel.

  2. Symmetric airfoil geometry effects on leading edge noise.

    Science.gov (United States)

    Gill, James; Zhang, X; Joseph, P

    2013-10-01

    Computational aeroacoustic methods are applied to the modeling of noise due to interactions between gusts and the leading edge of real symmetric airfoils. Single frequency harmonic gusts are interacted with various airfoil geometries at zero angle of attack. The effects of airfoil thickness and leading edge radius on noise are investigated systematically and independently for the first time, at higher frequencies than previously used in computational methods. Increases in both leading edge radius and thickness are found to reduce the predicted noise. This noise reduction effect becomes greater with increasing frequency and Mach number. The dominant noise reduction mechanism for airfoils with real geometry is found to be related to the leading edge stagnation region. It is shown that accurate leading edge noise predictions can be made when assuming an inviscid meanflow, but that it is not valid to assume a uniform meanflow. Analytic flat plate predictions are found to over-predict the noise due to a NACA 0002 airfoil by up to 3 dB at high frequencies. The accuracy of analytic flat plate solutions can be expected to decrease with increasing airfoil thickness, leading edge radius, gust frequency, and Mach number.

  3. A Unit-Problem Investigation of Blunt Leading-Edge Separation Motivated by AVT-161 SACCON Research

    Science.gov (United States)

    Luckring, James M.; Boelens, Okko J.

    2011-01-01

    A research effort has been initiated to examine in more detail some of the challenging flow fields discovered from analysis of the SACCON configuration aerodynamics. This particular effort is oriented toward a diamond wing investigation specifically designed to isolate blunt leading-edge separation phenomena relevant to the SACCON investigations of the present workshop. The approach taken to design this new effort is reviewed along with the current status of the program.

  4. A Survey of Factors Affecting Blunt Leading-Edge Separation for Swept and Semi-Slender Wings

    Science.gov (United States)

    Luckring, James M.

    2010-01-01

    A survey is presented of factors affecting blunt leading-edge separation for swept and semi-slender wings. This class of separation often results in the onset and progression of separation-induced vortical flow over a slender or semi-slender wing. The term semi-slender is used to distinguish wings with moderate sweeps and aspect ratios from the more traditional highly-swept, low-aspect-ratio slender wing. Emphasis is divided between a selection of results obtained through literature survey a section of results from some recent research projects primarily being coordinated through NATO s Research and Technology Organization (RTO). An aircraft context to these studies is included.

  5. Potential environmental effects of the leading edge hydrokinetic energy technology.

    Science.gov (United States)

    2017-05-01

    The Volpe Center evaluated potential environmental challenges and benefits of the ARPA-E funded research project, Marine Hydrokinetic Energy Harvesting Using Cyber-Physical Systems, led by Brown University. The Leading Edge research team develo...

  6. Roughness Effects on the Formation of a Leading Edge Vortex

    Science.gov (United States)

    Elliott, Cassidy; Lang, Amy; Wahidi, Redha; Wilroy, Jacob

    2016-11-01

    Microscopic scales cover the wings of Monarch butterflies, creating a patterned surface. This patterning is an important natural flow control mechanism that is thought to delay the growth of the leading edge vortex (LEV) produced by the flapping motion of a wing. The increased skin friction caused by the scales leads to a weaker LEV being shed into the butterfly's wake, lessening drag and increasing flight efficiency. To test this theory, a plate of random roughness was designed in SolidWorks and printed on the Objet 30 Pro 3D printer. A 2x3x5 cubic foot tow tank was used to test the rough plate at Reynold's numbers of 1500, 3000, and 6000 (velocities of 8, 16, and 32 mm/s) at an angle of attack of 45 degrees. Particle Image Velocimetry (PIV) captured images of the LEV generated by the plate when towed upwards through the particle-seeded flow. Codes written in MatLab were used to automatically track and determine the strength of the LEV. Circulation values for the randomly-rough plate were then compared to the same values generated in a previous experiment that used a smooth plate and a grooved plate to determine the effect of the patterning on vortex development. Funding provided by NSF REU site Grant EEC 1358991 and CBET 1628600.

  7. Roughness Effects on the Formation of a Leading Edge Vortex

    Science.gov (United States)

    Elliott, Cassidy; Lang, Amy; Wahidi, Redha; Wilroy, Jacob

    2017-11-01

    Microscopic scales cover the wings of Monarch butterflies, creating a patterned surface that acts as a natural energy capture mechanism. This patterning is thought to delay the growth of the leading edge vortex (LEV) produced by the flapping motion of a wing. Increased skin friction caused by the scales leads to a weaker LEV being shed into the butterfly's wake, lessening drag and increasing flight efficiency. To test how this roughness effects LEV formation, a plate of random roughness was designed in SolidWorks and printed on the Objet 30 Pro 3D printer. A 2x3x5 cubic foot tow tank was used to test the rough plate at Reynold's numbers of 1500, 3000, and 6000 (velocities of 8, 16, and 32 mm/s) at an angle of attack of 45 degrees. Images were captured of the LEV generated when the plate was towed upwards through the particle-seeded flow. These images were used to determine the XY velocity of the particles using a technique called Digital Particle Image Velocimetry (DPIV). Codes written in MATLAB were used to track and measure the strength of the LEV. Circulation values for the randomly-rough plate were then compared to the same values generated in a previous experiment that used a smooth plate and a grooved plate to determine the effect of the patterning on vortex development. Funding for this research project was provided by the National Science Foundation under the Research Experience for Undergraduates (REU) program (REU Supplement CBET 1628600 under CBET 1335848).

  8. Leading edge effect in laminar boundary layer excitation by sound

    International Nuclear Information System (INIS)

    Leehey, P.; Shapiro, P.

    1980-01-01

    Essentially plane pure tone sound waves were directed downstream over a heavily damped smooth flat plate installed in a low turbulence (0.04%) subsonic wind tunnel. Laminar boundary layer disturbance growth rates were measured with and without sound excitation and compared with numerical results from spatial stability theory. The data indicate that the sound field and Tollmien-Schlichting (T-S) waves coexist with comparable amplitudes when the latter are damped; moreover, the response is linear. Higher early growth rates occur for excitation by sound than by stream turbulence. Theoretical considerations indicate that the boundary layer is receptive to sound excitation primarily at the test plate leading edge. (orig.)

  9. Effect of leading-edge geometry on boundary-layer receptivity to freestream sound

    Science.gov (United States)

    Lin, Nay; Reed, Helen L.; Saric, W. S.

    1991-01-01

    The receptivity to freestream sound of the laminar boundary layer over a semi-infinite flat plate with an elliptic leading edge is simulated numerically. The incompressible flow past the flat plate is computed by solving the full Navier-Stokes equations in general curvilinear coordinates. A finite-difference method which is second-order accurate in space and time is used. Spatial and temporal developments of the Tollmien-Schlichting wave in the boundary layer, due to small-amplitude time-harmonic oscillations of the freestream velocity that closely simulate a sound wave travelling parallel to the plate, are observed. The effect of leading-edge curvature is studied by varying the aspect ratio of the ellipse. The boundary layer over the flat plate with a sharper leading edge is found to be less receptive. The relative contribution of the discontinuity in curvature at the ellipse-flat-plate juncture to receptivity is investigated by smoothing the juncture with a polynomial. Continuous curvature leads to less receptivity. A new geometry of the leading edge, a modified super ellipse, which provides continuous curvature at the juncture with the flat plate, is used to study the effect of continuous curvature and inherent pressure gradient on receptivity.

  10. Cooling Strategies for Vane Leading Edges in a Syngas Environment Including Effects of Deposition and Turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Ames, Forrest [Univ. of North Dakota, Grand Forks, ND (United States); Bons, Jeffrey [Univ. of North Dakota, Grand Forks, ND (United States)

    2014-09-30

    The Department of Energy has goals to move land based gas turbine systems to alternate fuels including coal derived synthetic gas and hydrogen. Coal is the most abundant energy resource in the US and in the world and it is economically advantageous to develop power systems which can use coal. Integrated gasification combined cycles are (IGCC) expected to allow the clean use of coal derived fuels while improving the ability to capture and sequester carbon dioxide. These cycles will need to maintain or increase turbine entry temperatures to develop competitive efficiencies. The use of coal derived syngas introduces a range of potential contaminants into the hot section of the gas turbine including sulfur, iron, calcium, and various alkali metals. Depending on the effectiveness of the gas clean up processes, there exists significant likelihood that the remaining materials will become molten in the combustion process and potentially deposit on downstream turbine surfaces. Past evidence suggests that deposition will be a strong function of increasing temperature. Currently, even with the best gas cleanup processes a small level of particulate matter in the syngas is expected. Consequently, particulate deposition is expected to be an important consideration in the design of turbine components. The leading edge region of first stage vanes most often have higher deposition rates than other areas due to strong fluid acceleration and streamline curvature in the vicinity of the surface. This region remains one of the most difficult areas in a turbine nozzle to cool due to high inlet temperatures and only a small pressure ratio for cooling. The leading edge of a vane often has relatively high heat transfer coefficients and is often cooled using showerhead film cooling arrays. The throat of the first stage nozzle is another area where deposition potentially has a strongly adverse effect on turbine performance as this region meters the turbine inlet flow. Based on roughness

  11. Numerical investigation of rarefaction effects in the vicinity of a sharp leading edge

    Science.gov (United States)

    Pan, Shaowu; Gao, Zhenxun; Lee, Chunhian

    2014-12-01

    This paper presents a study of rarefaction effect on hypersonic flow over a sharp leading edge. Both continuum approach and kinetic method: a widely spread commercial Computational Fluid Dynamics-Navior-Stokes-Fourier (CFD-NSF) software - Fluent together with a direct simulation Monte Carlo (DSMC) code developed by the authors are employed for simulation of transition regime with Knudsen number ranging from 0.005 to 0.2. It is found that Fluent can predict the wall fluxes in the case of hypersonic argon flow over the sharp leading edge for the lowest Kn case (Kn = 0.005) in current paper while for other cases it also has a good agreement with DSMC except at the location near the sharp leading edge. Among all of the wall fluxes, it is found that coefficient of pressure is the most sensitive to rarefaction while heat transfer is the least one. A parameter based on translational nonequilibrium and a cut-off value of 0.34 is proposed for continuum breakdown in this paper. The structure of entropy and velocity profile in boundary layer is analyzed. Also, it is found that the ratio of heat transfer coefficient to skin friction coefficient remains uniform along the surface for the four cases in this paper.

  12. On the effect of leading edge blowing on circulation control airfoil aerodynamics

    Science.gov (United States)

    Mclachlan, B. G.

    1987-01-01

    In the present context the term circulation control is used to denote a method of lift generation that utilizes tangential jet blowing over the upper surface of a rounded trailing edge airfoil to determine the location of the boundary layer separation points, thus setting an effective Kutta condition. At present little information exists on the flow structure generated by circulation control airfoils under leading edge blowing. Consequently, no theoretical methods exist to predict airfoil performance under such conditions. An experimental study of the flow field generated by a two dimensional circulation control airfoil under steady leading and trailing edge blowing was undertaken. The objective was to fundamentally understand the overall flow structure generated and its relation to airfoil performance. Flow visualization was performed to define the overall flow field structure. Measurements of the airfoil forces were also made to provide a correlation of the observed flow field structure to airfoil performance. Preliminary results are presented, specifically on the effect on the flow field structure of leading edge blowing, alone and in conjunction with trailing edge blowing.

  13. Effects of Leading Edge Defect on the Aerodynamic and Flow Characteristics of an S809 Airfoil.

    Science.gov (United States)

    Wang, Yan; Zheng, Xiaojing; Hu, Ruifeng; Wang, Ping

    Unexpected performance degradation occurs in wind turbine blades due to leading edge defect when suffering from continuous impacts with rain drops, hails, insects, or solid particles during its operation life. To assess this issue, this paper numerically investigates the steady and dynamic stall characteristics of an S809 airfoil with various leading edge defects. More leading edge defect sizes and much closer to practical parameters are investigated in the paper. Numerical computation is conducted using the SST k-ω turbulence model, and the method has been validated by comparison with existed published data. In order to ensure the calculation convergence, the residuals for the continuity equation are set to be less than 10-7 and 10-6 in steady state and dynamic stall cases. The simulations are conducted with the software ANSYS Fluent 13.0. It is found that the characteristics of aerodynamic coefficients and flow fields are sensitive to leading edge defect both in steady and dynamic conditions. For airfoils with the defect thickness of 6%tc, leading edge defect has a relative small influence on the aerodynamics of S809 airfoil. For other investigated defect thicknesses, leading edge defect has much greater influence on the flow field structures, pressure coefficients and aerodynamic characteristics of airfoil at relative small defect lengths. For example, the lift coefficients decrease and drag coefficients increase sharply after the appearance of leading edge defect. However, the aerodynamic characteristics could reach a constant value when the defect length is large enough. The flow field, pressure coefficient distribution and aerodynamic coefficients do not change a lot when the defect lengths reach to 0.5%c,1%c, 2%c and 3%c with defect thicknesses of 6%tc, 12%tc,18%tc and 25%tc, respectively. In addition, the results also show that the critical defect length/thickness ratio is 0.5, beyond which the aerodynamic characteristics nearly remain unchanged. In

  14. Effects of Leading Edge Defect on the Aerodynamic and Flow Characteristics of an S809 Airfoil.

    Directory of Open Access Journals (Sweden)

    Yan Wang

    Full Text Available Unexpected performance degradation occurs in wind turbine blades due to leading edge defect when suffering from continuous impacts with rain drops, hails, insects, or solid particles during its operation life. To assess this issue, this paper numerically investigates the steady and dynamic stall characteristics of an S809 airfoil with various leading edge defects. More leading edge defect sizes and much closer to practical parameters are investigated in the paper.Numerical computation is conducted using the SST k-ω turbulence model, and the method has been validated by comparison with existed published data. In order to ensure the calculation convergence, the residuals for the continuity equation are set to be less than 10-7 and 10-6 in steady state and dynamic stall cases. The simulations are conducted with the software ANSYS Fluent 13.0.It is found that the characteristics of aerodynamic coefficients and flow fields are sensitive to leading edge defect both in steady and dynamic conditions. For airfoils with the defect thickness of 6%tc, leading edge defect has a relative small influence on the aerodynamics of S809 airfoil. For other investigated defect thicknesses, leading edge defect has much greater influence on the flow field structures, pressure coefficients and aerodynamic characteristics of airfoil at relative small defect lengths. For example, the lift coefficients decrease and drag coefficients increase sharply after the appearance of leading edge defect. However, the aerodynamic characteristics could reach a constant value when the defect length is large enough. The flow field, pressure coefficient distribution and aerodynamic coefficients do not change a lot when the defect lengths reach to 0.5%c,1%c, 2%c and 3%c with defect thicknesses of 6%tc, 12%tc,18%tc and 25%tc, respectively. In addition, the results also show that the critical defect length/thickness ratio is 0.5, beyond which the aerodynamic characteristics nearly remain

  15. Prediction of Film Cooling Effectiveness on a Gas Turbine Blade Leading Edge Using ANN and CFD

    Science.gov (United States)

    Dávalos, J. O.; García, J. C.; Urquiza, G.; Huicochea, A.; De Santiago, O.

    2018-05-01

    In this work, the area-averaged film cooling effectiveness (AAFCE) on a gas turbine blade leading edge was predicted by employing an artificial neural network (ANN) using as input variables: hole diameter, injection angle, blowing ratio, hole and columns pitch. The database used to train the network was built using computational fluid dynamics (CFD) based on a two level full factorial design of experiments. The CFD numerical model was validated with an experimental rig, where a first stage blade of a gas turbine was represented by a cylindrical specimen. The ANN architecture was composed of three layers with four neurons in hidden layer and Levenberg-Marquardt was selected as ANN optimization algorithm. The AAFCE was successfully predicted by the ANN with a regression coefficient R2<0.99 and a root mean square error RMSE=0.0038. The ANN weight coefficients were used to estimate the relative importance of the input parameters. Blowing ratio was the most influential parameter with relative importance of 40.36 % followed by hole diameter. Additionally, by using the ANN model, the relationship between input parameters was analyzed.

  16. Effect of guide wall on jet impingement cooling in blade leading edge channel

    International Nuclear Information System (INIS)

    Zhao, Qing-Yang; Chung, Heeyoon; Choi, Seok Min; Cho, Hyung Hee

    2016-01-01

    The characteristics of fluid flow and heat transfer, which are affected by the guide wall in a jet impinged leading edge channel, have been investigated numerically using three-dimensional Reynolds-averaged Navier-Stokes analysis via the shear stress transport turbulence model and gamma theta transitional turbulence model. A constant wall heat flux condition has been applied to the leading edge surface. The jet-to-surface distance is constant, which is three times that of the jet diameter. The arrangement of the guide wall near the jet hole is set as a variable. Results presented in this study include the Nusselt number contour, velocity vector, streamline with velocity, and local Nusselt number distribution along the central line on the leading edge surface. The average Nusselt number and average pressure loss between jet nozzle and channel exit are calculated to assess the thermal performance. The application of the guide wall is aimed at improving heat transfer uniformity on the leading edge surface. Results indicated that the streamwise guide wall ensures the vertical jet impingement flow intensity and prevents the flow after impingement to reflux into jet flow. Thus, a combined rectangular guide wall benefits the average heat transfer, thermal performance and heat transfer distribution uniformity

  17. The effect of butterfly-scale inspired patterning on leading-edge vortex growth

    Science.gov (United States)

    Wilroy, Jacob Aaron

    Leading edge vortices (LEVs) are important for generating thrust and lift in flapping flight, and the surface patterning (scales) on butterfly wings is hypothesized to play a role in the vortex formation of the LEV. To simplify this complex flow problem, an experiment was designed to focus on the alteration of 2-D vortex development with a variation in surface patterning. Specifically, the secondary vorticity generated by the LEV interacting at the patterned surface was studied, as well as the subsequent effect on the LEV's growth rate and peak circulation. For this experiment, rapid-prototyped grooves based on the scale geometry of the Monarch butterfly (Danaus plexippus) were created using additive manufacturing and were attached to a flat plate with a chordwise orientation, thus increasing plate surface area. The vortex generated by the grooved plate was then compared to a smooth plate case in an experiment where the plate translated vertically through a 2 x 3 x 5 cubic foot tow tank. The plate was impulsively started in quiescent water and flow fields at Rec = 1416, 2833, and 5667 are examined using Digital Particle Image Velocimetry (DPIV). The maximum vortex formation number is 2.8 and is based on the flat plate travel length and chord length. Flow fields from each case show the generation of a secondary vortex whose interaction with the shear layer and LEV caused different behaviors depending upon the surface type. The vortex development process varied for each Reynolds number and it was found that for the lowest Reynolds number case a significant difference does not exist between surface types, however, for the other two cases the grooves affected the secondary vortex's behavior and the LEV's ability to grow at a rate similar to the smooth plate case.

  18. On the effects of leading edge vortex generators on an OA209 airfoil

    OpenAIRE

    Heine, Benjamin; Mulleners, Karen; Gardner, Anthony; Mai, Holger

    2009-01-01

    Leading edge vortex generators have been found to significantly increase the aerodynamic performance of an airfoil under dynamic stall conditions. However, the principle of operation of these devices is still unclear. Therefore static wind and water tunnel experiments as well as CFD simulations have been conducted on a rotary aircraft wing profile OA209. A POD analysis applied to the vector fields generated by PIV measurements showed that the vortex generators break larger flow structures...

  19. Effects of Alternate Leading Edge Cutback on the Space Shuttle Main Engine Low Pressure Fuel Pump

    Science.gov (United States)

    Mulder, Andrew; Skelley, Stephen

    2016-01-01

    A higher order cavitation oscillation observed in the SSME low pressure fuel pump has been eliminated in water flow testing of a modified subscale replica of the inducer. The low pressure pump was modified by removing the outboard sections of two opposing blades of the four-bladed inducer, blending the "cutback" regions into the blades at the leading edge and tip, and removing material on the suction sides to decrease the exposed leading edge thickness. The leading edge tips of the cutback blades were moved approximately 25 degrees from their previous locations, thereby increasing one blade to blade spacing, decreasing the second, while simultaneously moving the cutback tips downstream. The test was conducted in MSFC's inducer test loop at scaled operating conditions in degassed and filtered water. In addition to eliminating HOC across the entire scaled operating regime, rotating cavitation was suppressed while the range of both alternate blade and asymmetric cavitation were increased. These latter phenomena, and more significantly, the shifts between these cavitation modes also resulted in significant changes to the head coefficient at low cavitation numbers. Reverse flow was detected at a slightly larger flow coefficient with the cutback inducer and suction capability was reduced by approximately 1 velocity head at and above approximately 90% of the reference flow coefficient. These performance changes along with more intense reverse flow are consistent with poor flow area management and increased incidence in the cutback region. Although the test demonstrated that the inducer modification was successful at eliminating the higher order cavitation across the entire scaled operating regime, different, previously unobserved, cavitation oscillations were introduced and significant performance penalties were imposed.

  20. Effects of free-stream turbulence intensity and blowing ratio on film cooling of turbine blade leading edge

    International Nuclear Information System (INIS)

    Kim, S. M.; Kim, Youn J.; Cho, H. H.

    2001-01-01

    We used a cylindrical model which simulates turbine blade leading edge to investigate the effects of free-stream turbulence intensity and blowing ratio on film cooling of turbine blade leading edge. Tests are carried out in a low-speed wind tunnel on a cylindrical model with three rows of injection holes. Mainstream Reynolds number based on the cylinder diameter was 7.1x10 4 . Two types of turbulence grid are used to increase a free-stream turbulence intensity. The effect of coolant blowing ratio was studied for various blowing ratios. For each blowing ratios, wall temperatures around the surface of the test model are measured by thermocouples installed inside the model. Results show that blowing ratios have small effect on spanwise-averaged film effectiveness at high free-stream turbulence intensity. However, an increase in free-stream turbulence intensity enhances significantly spanwise-averaged film effectiveness at low blowing ratio

  1. Exploratory study of the effects of wing-leading-edge modifications on the stall/spin behavior of a light general aviation airplane

    Science.gov (United States)

    1979-01-01

    Configurations with full-span and segmented leading-edge flaps and full-span and segmented leading-edge droop were tested. Studies were conducted with wind-tunnel models, with an outdoor radio-controlled model, and with a full-scale airplane. Results show that wing-leading-edge modifications can produce large effects on stall/spin characteristics, particularly on spin resistance. One outboard wing-leading-edge modification tested significantly improved lateral stability at stall, spin resistance, and developed spin characteristics.

  2. Aerodynamic forces and flow structures of the leading edge vortex on a flapping wing considering ground effect

    International Nuclear Information System (INIS)

    Truong, Tien Van; Yoon, Kwang Joon; Byun, Doyoung; Kim, Min Jun; Park, Hoon Cheol

    2013-01-01

    The aim of this work is to provide an insight into the aerodynamic performance of the beetle during takeoff, which has been estimated in previous investigations. We employed a scaled-up electromechanical model flapping wing to measure the aerodynamic forces and the three-dimensional flow structures on the flapping wing. The ground effect on the unsteady forces and flow structures were also characterized. The dynamically scaled wing model could replicate the general stroke pattern of the beetle's hind wing kinematics during takeoff flight. Two wing kinematic models have been studied to examine the influences of wing kinematics on unsteady aerodynamic forces. In the first model, the angle of attack is asymmetric and varies during the translational motion, which is the flapping motion of the beetle's hind wing. In the second model, the angle of attack is constant during the translational motion. The instantaneous aerodynamic forces were measured for four strokes during the beetle's takeoff by the force sensor attached at the wing base. Flow visualization provided a general picture of the evolution of the three-dimensional leading edge vortex (LEV) on the beetle hind wing model. The LEV is stable during each stroke, and increases radically from the root to the tip, forming a leading-edge spiral vortex. The force measurement results show that the vertical force generated by the hind wing is large enough to lift the beetle. For the beetle hind wing kinematics, the total vertical force production increases 18.4% and 8.6% for the first and second strokes, respectively, due to the ground effect. However, for the model with a constant angle of attack during translation, the vertical force is reduced during the first stroke. During the third and fourth strokes, the ground effect is negligible for both wing kinematic patterns. This finding suggests that the beetle's flapping mechanism induces a ground effect that can efficiently lift its body from the ground during takeoff

  3. Effect of jet nozzle geometry on flow and heat transfer performance of vortex cooling for gas turbine blade leading edge

    International Nuclear Information System (INIS)

    Du, Changhe; Li, Liang; Wu, Xin; Feng, Zhenping

    2016-01-01

    Highlights: • We establish a suitable vortex chamber model for gas turbine blade leading edge. • Mechanism of vortex cooling is further discussed and presented. • Influences of jet nozzle geometry on vortex cooling characteristics are researched. • This paper focuses on assessment of flow field and thermal performance for different jet nozzle aspect ratio and area. - Abstract: In this paper, 3D viscous steady Reynolds Averaged Navier–Stokes (RANS) equations are utilized to investigate the influence of jet nozzle geometry on flow and thermal behavior of vortex cooling for gas turbine blades. Comparison between calculation with different turbulence models and the experimental data is conducted, and results show that the standard k-ω model provides the best accuracy. The grid independence analysis is performed to obtain the proper mesh number. First, the mechanism of vortex cooling is further discussed, and the pronounced impact of kinetic turbulence intensity, thin thermal boundary layer, violent radial convection and complex vortices on enhanced heat transfer performance is confirmed. Then, seven jet nozzle aspect ratios and seven jet nozzle to chamber cross section area ratios are selected to research the flow field and thermal characteristics of vortex cooling focusing on the streamline, static pressure ratio, total pressure loss ratio and Nusselt number. It is presented that the jet nozzle aspect ratio and jet nozzle to chamber cross section area ratio both impose a significant effect on the flow and thermal parameters. The averaged Nusselt number decreases at first and then increases with the increasing jet nozzle aspect ratio, reaching highest when aspect ratio equals to 1. The effect of area ratio on averaged Nusselt number is complex. Finally, the heat transfer results in this study are compared with other previous works. Results indicate that good agreement with previous data is achieved, and the enhanced thermal behavior may be acquired by

  4. The effect of aspect ratio on the leading-edge vortex over an insect-like flapping wing.

    Science.gov (United States)

    Phillips, Nathan; Knowles, Kevin; Bomphrey, Richard J

    2015-10-09

    Insect wing shapes are diverse and a renowned source of inspiration for the new generation of autonomous flapping vehicles, yet the aerodynamic consequences of varying geometry is not well understood. One of the most defining and aerodynamically significant measures of wing shape is the aspect ratio, defined as the ratio of wing length (R) to mean wing chord (c). We investigated the impact of aspect ratio, AR, on the induced flow field around a flapping wing using a robotic device. Rigid rectangular wings ranging from AR = 1.5 to 7.5 were flapped with insect-like kinematics in air with a constant Reynolds number (Re) of 1400, and a dimensionless stroke amplitude of 6.5c (number of chords traversed by the wingtip). Pseudo-volumetric, ensemble-averaged, flow fields around the wings were captured using particle image velocimetry at 11 instances throughout simulated downstrokes. Results confirmed the presence of a high-lift, separated flow field with a leading-edge vortex (LEV), and revealed that the conical, primary LEV grows in size and strength with increasing AR. In each case, the LEV had an arch-shaped axis with its outboard end originating from a focus-sink singularity on the wing surface near the tip. LEV detachment was observed for AR > 1.5 around mid-stroke at ~70% span, and initiated sooner over higher aspect ratio wings. At AR > 3 the larger, stronger vortex persisted under the wing surface well into the next half-stroke leading to a reduction in lift. Circulatory lift attributable to the LEV increased with AR up to AR = 6. Higher aspect ratios generated proportionally less lift distally because of LEV breakdown, and also less lift closer to the wing root due to the previous LEV's continuing presence under the wing. In nature, insect wings go no higher than AR ~ 5, likely in part due to architectural and physiological constraints but also because of the reducing aerodynamic benefits of high AR wings.

  5. Moveable Leading Edge Device for a Wing

    Science.gov (United States)

    Pitt, Dale M. (Inventor); Eckstein, Nicholas Stephen (Inventor)

    2013-01-01

    A method and apparatus for managing a flight control surface system. A leading edge section on a wing of an aircraft is extended into a deployed position. A deformable section connects the leading edge section to a trailing section. The deformable section changes from a deformed shape to an original shape when the leading edge section is moved into the deployed position. The leading edge section on the wing is moved from the deployed position to an undeployed position. The deformable section changes to the deformed shape inside of the wing.

  6. Dynamic Stall Characteristics of Drooped Leading Edge Airfoils

    Science.gov (United States)

    Sankar, Lakshmi N.; Sahin, Mehmet; Gopal, Naveen

    2000-01-01

    Helicopters in high-speed forward flight usually experience large regions of dynamic stall over the retreating side of the rotor disk. The rapid variations in the lift and pitching moments associated with the stall process can result in vibratory loads, and can cause fatigue and failure of pitch links. In some instances, the large time lag between the aerodynamic forces and the blade motion can trigger stall flutter. A number of techniques for the alleviation of dynamic stall have been proposed and studied by researchers. Passive and active control techniques have both been explored. Passive techniques include the use of high solidity rotors that reduce the lift coefficients of individual blades, leading edge slots and leading edge slats. Active control techniques include steady and unsteady blowing, and dynamically deformable leading edge (DDLE) airfoils. Considerable amount of experimental and numerical data has been collected on the effectiveness of these concepts. One concept that has not received as much attention is the drooped-leading edge airfoil idea. It has been observed in wind tunnel studies and flight tests that drooped leading edge airfoils can have a milder dynamic stall, with a significantly milder load hysteresis. Drooped leading edge airfoils may not, however, be suitable at other conditions, e.g. in hover, or in transonic flow. Work needs to be done on the analysis and design of drooped leading edge airfoils for efficient operation in a variety of flight regimes (hover, dynamic stall, and transonic flow). One concept that is worthy of investigation is the dynamically drooping airfoil, where the leading edge shape is changed roughly once-per-rev to mitigate the dynamic stall.

  7. Flow over 50º Delta Wings with Different Leading-Edge Radii

    NARCIS (Netherlands)

    Verhaagen, N.G.

    2011-01-01

    The experimental study focuses on the effects of the leading-edge radius on the flow over 50º swept delta wing models. Three models were tested, one model has a sharp leading edge and two other have a semi-circular leading edge of different radius. The vortical flow on and off the surface of the

  8. Experimental Surface Pressure Data Obtained on 65 deg Delta Wing Across Reynolds Number and Mach Number Ranges. Volume 2; Small-Radius Leading Edge

    Science.gov (United States)

    Chu, Julio; Luckring, James M.

    1996-01-01

    An experimental wind tunnel test of a 65 deg. delta wing model with interchangeable leading edges was conducted in the Langley National Transonic Facility (NTF). The objective was to investigate the effects of Reynolds and Mach numbers on slender-wing leading-edge vortex flows with four values of wing leading-edge bluntness. Experimentally obtained pressure data are presented without analysis in tabulated and graphical formats across a Reynolds number range of 6 x 10(exp 6) to 84 x 10(exp 6) at a Mach number of 0.85 and across a Mach number range of 0.4 to 0.9 at Reynolds numbers of 6 x 10(exp 6) and 60 x 10(exp 6). Normal-force and pitching-moment coefficient plots for these Reynolds number and Mach number ranges are also presented.

  9. Leading-edge vortex lifts swifts.

    Science.gov (United States)

    Videler, J J; Stamhuis, E J; Povel, G D E

    2004-12-10

    The current understanding of how birds fly must be revised, because birds use their hand-wings in an unconventional way to generate lift and drag. Physical models of a common swift wing in gliding posture with a 60 degrees sweep of the sharp hand-wing leading edge were tested in a water tunnel. Interactions with the flow were measured quantitatively with digital particle image velocimetry at Reynolds numbers realistic for the gliding flight of a swift between 3750 and 37,500. The results show that gliding swifts can generate stable leading-edge vortices at small (5 degrees to 10 degrees) angles of attack. We suggest that the flow around the arm-wings of most birds can remain conventionally attached, whereas the swept-back hand-wings generate lift with leading-edge vortices.

  10. Wing Leading Edge Concepts for Noise Reduction

    Science.gov (United States)

    Shmilovich, Arvin; Yadlin, Yoram; Pitera, David M.

    2010-01-01

    This study focuses on the development of wing leading edge concepts for noise reduction during high-lift operations, without compromising landing stall speeds, stall characteristics or cruise performance. High-lift geometries, which can be obtained by conventional mechanical systems or morphing structures have been considered. A systematic aerodynamic analysis procedure was used to arrive at several promising configurations. The aerodynamic design of new wing leading edge shapes is obtained from a robust Computational Fluid Dynamics procedure. Acoustic benefits are qualitatively established through the evaluation of the computed flow fields.

  11. Leading-Edge Vortex lifts swifts

    NARCIS (Netherlands)

    Videler, JJ; Stamhuis, EJ; Povel, GDE

    2004-01-01

    The current understanding of how birds fly must be revised, because birds use their hand-wings in an unconventional way to generate lift and drag. Physical models of a common swift wing in gliding posture with a 60degrees sweep of the sharp hand-wing leading edge were tested in a water tunnel.

  12. Development of Advanced High Lift Leading Edge Technology for Laminar Flow Wings

    Science.gov (United States)

    Bright, Michelle M.; Korntheuer, Andrea; Komadina, Steve; Lin, John C.

    2013-01-01

    This paper describes the Advanced High Lift Leading Edge (AHLLE) task performed by Northrop Grumman Systems Corporation, Aerospace Systems (NGAS) for the NASA Subsonic Fixed Wing project in an effort to develop enabling high-lift technology for laminar flow wings. Based on a known laminar cruise airfoil that incorporated an NGAS-developed integrated slot design, this effort involved using Computational Fluid Dynamics (CFD) analysis and quality function deployment (QFD) analysis on several leading edge concepts, and subsequently down-selected to two blown leading-edge concepts for testing. A 7-foot-span AHLLE airfoil model was designed and fabricated at NGAS and then tested at the NGAS 7 x 10 Low Speed Wind Tunnel in Hawthorne, CA. The model configurations tested included: baseline, deflected trailing edge, blown deflected trailing edge, blown leading edge, morphed leading edge, and blown/morphed leading edge. A successful demonstration of high lift leading edge technology was achieved, and the target goals for improved lift were exceeded by 30% with a maximum section lift coefficient (Cl) of 5.2. Maximum incremental section lift coefficients ( Cl) of 3.5 and 3.1 were achieved for a blown drooped (morphed) leading edge concept and a non-drooped leading edge blowing concept, respectively. The most effective AHLLE design yielded an estimated 94% lift improvement over the conventional high lift Krueger flap configurations while providing laminar flow capability on the cruise configuration.

  13. On the study of wavy leading-edge vanes to achieve low fan interaction noise

    Science.gov (United States)

    Tong, Fan; Qiao, Weiyang; Xu, Kunbo; Wang, Liangfeng; Chen, Weijie; Wang, Xunnian

    2018-04-01

    The application of wavy leading-edge vanes to reduce a single-stage axial fan noise is numerically studied. The aerodynamic and acoustic performance of the fan is numerically investigated using a hybrid unsteady Reynolds averaged Navier-Stokes (URANS)/acoustic analogy method (Goldstein equations). First, the hybrid URANS/Goldstein method is developed and successfully validated against experiment results. Next, numerical simulations are performed to investigate the noise reduction effects of the wavy leading-edge vanes. The aerodynamic and acoustic performance is assessed for a fan with vanes equipped with two different wavy leading-edge profiles and compared with the performance of conventional straight leading-edge vanes. Results indicate that a fan with wavy leading-edge vanes produces lower interaction noise than the baseline fan without a significant loss in aerodynamic performance. In fact, it is demonstrated that wavy leading-edge vanes have the potential to lead to both aerodynamic and acoustic improvements. The two different wavy leading-edge profiles are shown to successfully reduce the fan tone sound power level by 1.2 dB and 4.3 dB, respectively. Fan efficiency is also improved by about 1% with one of the tested wavy leading-edge profiles. Large eddy simulation (LES) is also performed for a simplified fan stage model to assess the effects of wavy leading-edge vanes on the broadband fan noise. Results indicate that the overall sound power level of a fan can be reduced by about 4 dB with the larger wavy leading-edge profile. Finally, the noise reduction mechanisms are investigated and analysed. It is found that the wavy leading-edge profiles can induce significant streamwise vorticity around the leading-edge protuberances and reduce pressure fluctuations (especially at locations of wavy leading-edge hills) and unsteady forces on the stator vanes. The underlying mechanism of the reduced pressure fluctuations is also discussed by examining the magnitude

  14. Numerical Simulation and Experiment of a Lifting Body with Leading-Edge Rotating Cylinder

    OpenAIRE

    A. Badarudin; C. S. Oon; S. N. Kazi; N. Nik-Ghazali; Y. J. Lee; W. T. Chong

    2013-01-01

    An experimental and simulation flight test has been carried out to evaluate the longitudinal gliding characteristics of a lifting body with blunted half-cone geometry. The novelty here is the lifting body's pitch control mechanism, which consists of a pair of leading-edge rotating cylinders. Flight simulation uses aerodynamic data from computational fluid dynamics supported by wind-tunnel test. Flight test consists of releasing an aluminum lifting body model from a moving vehicle at the appro...

  15. Investigation of irradiation effects on highly integrated leading-edge electronic components of diagnostics and control systems for LHD deuterium operation

    Science.gov (United States)

    Ogawa, K.; Nishitani, T.; Isobe, M.; Murata, I.; Hatano, Y.; Matsuyama, S.; Nakanishi, H.; Mukai, K.; Sato, M.; Yokota, M.; Kobuchi, T.; Nishimura, T.; Osakabe, M.

    2017-08-01

    High-temperature and high-density plasmas are achieved by means of real-time control, fast diagnostic, and high-power heating systems. Those systems are precisely controlled via highly integrated electronic components, but can be seriously affected by radiation damage. Therefore, the effects of irradiation on currently used electronic components should be investigated for the control and measurement of Large Helical Device (LHD) deuterium plasmas. For the precise estimation of the radiation field in the LHD torus hall, the MCNP6 code is used with the cross-section library ENDF B-VI. The geometry is modeled on the computer-aided design. The dose on silicon, which is a major ingredient of electronic components, over nine years of LHD deuterium operation shows that the gamma-ray contribution is dominant. Neutron irradiation tests were performed in the OKTAVIAN at Osaka University and the Fast Neutron Laboratory at Tohoku University. Gamma-ray irradiation tests were performed at the Nagoya University Cobalt-60 irradiation facility. We found that there are ethernet connection failures of programmable logic controller (PLC) modules due to neutron irradiation with a neutron flux of 3  ×  106 cm-2 s-1. This neutron flux is equivalent to that expected at basement level in the LHD torus hall without a neutron shield. Most modules of the PLC are broken around a gamma-ray dose of 100 Gy. This is comparable with the dose in the LHD torus hall over nine years. If we consider the dose only, these components may survive more than nine years. For the safety of the LHD operation, the electronic components in the torus hall have been rearranged.

  16. Aerodynamic performance investigation on waverider with variable blunt radius in hypersonic flows

    Science.gov (United States)

    Li, Shibin; Wang, Zhenguo; Huang, Wei; Xu, Shenren; Yan, Li

    2017-08-01

    Waverider is an important candidate for the design of hypersonic vehicles. However, the ideal waverider cannot be manufactured because of its sharp leading edge, so the leading edge should be blunted. In the paper, the HMB solver and laminar flow model have been utilized to obtain the flow field properties around the blunt waverider with the freestream Mach number being 8.0, and several novel strategies have been suggested to improve the aerodynamic performance of blunt waverider. The numerical method has been validated against experimental data, and the Stanton number(St) of the predicted result has been analyzed. The obtained results show good agreement with the experimental data. Stmax decreases by 58% and L/D decreases by 8.2% when the blunt radius increases from 0.0002 m to 0.001 m. ;Variable blunt waverider; is a good compromise for aerodynamic performance and thermal insulation. The aero-heating characteristics are very sensitive to Rmax. The position of the smallest blunt radius has a great effect on the aerodynamic performance. In addition, the type of blunt leading edge has a great effect on the aero-heating characteristics when Rmax is fixed. Therefore, out of several designs, Type 4is the best way to achieve the good overall performance. The ;Variable blunt waverider; not only improves the aerodynamic performance, but also makes the aero-heating become evenly-distributed, leading to better aero-heating characteristics.

  17. Control of leading edge vortex breakdown by blowing

    Science.gov (United States)

    Visser, K. D.; Iwanski, K. P.; Nelson, R. C.; Ng, T. T.

    1988-01-01

    An investigation into the effects of using a jet of air to control the vortex breakdown position on a 70 degree delta wing is presented. The specific objectives focused on optimizing the blowing positions in terms of maximum lift increments obtained for minimum blowing rates. The tests were conducted at chord Reynolds numbers of 150,000, 200,000, and 250,000 at angles of incidence of 30 and 35 degrees. Visualization and force data is presented to show the effect of the jet on the wing aerodynamic characteristics. The results indicate a jet position located at and aligned parallel to the leading edge to be the optimum. Nearness to the apex and tangency to the upper surface were also crucial factors. The influence of the jet on the leading edge vortex structure was examined using laser Doppler anemometry. Velocity surveys through the vortex showed that at high blowing rates the parallel velocity in the outer swirling region of the vortex increased and the normal velocity decreased. This resulted in a decrease in the swirling angle in the outer region. The peak core velocity was reduced and the vortex breakdown was delayed.

  18. Leading-Edge Flow Sensing for Aerodynamic Parameter Estimation

    Science.gov (United States)

    Saini, Aditya

    ow over a at plate at different freestream velocities in the NCSU subsonic wind tunnel. Experiments were also conducted to characterize the directional sensitivity of the microstructures by creating ow reversal at the sensor location to assess the sensor response. The results show that the direction of microfence deflection correctly reflects the local ow behavior as the ow direction is reversed at the sensor location and the magnitude of deflection correlates qualitatively to an increase in the freestream velocity. The knowledge of the ow-separation location integrated with the LEFS algorithm allows the possibility of extending the LEFS analysis to post-stall flight regimes, which is explored in the current work. Finally, the application of the LEFS algorithm to unsteady aerodynamics is investigated to identify the critical sequence of events associated with the formation of leading-edge vortices. Signatures of vortex formation on the airfoil surface can be captured in the surface-pressure measurements. Real-time knowledge of the unsteady ow phenomena holds significant potential for exploiting the enhanced-lift characteristics related to vortex formation and inhibiting the detrimental effects of dynamic stall in engineering applications such as helicopters, wind turbines, bio-inspired flight, and energy harvesting devices. Computational data was used to assess the capability of the LEFS outputs to identity the signatures associated with vortex formation, i.e. onset of vortex shedding, detachment, and termination. The results demonstrate useful correlation between the LEFS outputs and the LEV signatures.

  19. An Elongated Leading Edge Facilitates Rotation Flap Closure: In Vivo Demonstration.

    Science.gov (United States)

    Lichon, Vanessa; Barbosa, Naiara; Gomez, Doug; Goldman, Glenn

    2016-01-01

    Variation in the design of a rotation flap may affect wound closure tension. Lengthening the leading edge of a rotation flap has been a method of reducing the tension of closure in the primary motion. An in vitro study negating this tenant has been published. The authors set out to design an in vivo experiment to determine if lengthening the leading edge of a rotation flap has the effect of reducing closure tension in the primary motion of the repair. An animal study approved by Institutional Animal Care and Use Committee was undertaken in a pig model. A tension-measuring apparatus was designed using Teflon-coated wires and digital tensiometers. Rotation flaps of a standard design and with elongated leading edges were incised on the flanks of pigs under general anesthesia. Flap closure tensions were measured at points along the leading edge of the flap and in the secondary motion. Elongating the leading edge of a flap led to a statistically significant reduction in closure tension in the primary motion of the flap and at the flap tip. The secondary motion closure tensions were essentially unaffected. The authors confirm that elongating the leading edge of a standard rotation flap will reduce closure tension in the primary flap motion.

  20. Analytical model and stability analysis of the leading edge spar of a passively morphing ornithopter wing.

    Science.gov (United States)

    Wissa, Aimy; Calogero, Joseph; Wereley, Norman; Hubbard, James E; Frecker, Mary

    2015-10-26

    This paper presents the stability analysis of the leading edge spar of a flapping wing unmanned air vehicle with a compliant spine inserted in it. The compliant spine is a mechanism that was designed to be flexible during the upstroke and stiff during the downstroke. Inserting a variable stiffness mechanism into the leading edge spar affects its structural stability. The model for the spar-spine system was formulated in terms of the well-known Mathieu's equation, in which the compliant spine was modeled as a torsional spring with a sinusoidal stiffness function. Experimental data was used to validate the model and results show agreement within 11%. The structural stability of the leading edge spar-spine system was determined analytically and graphically using a phase plane plot and Strutt diagrams. Lastly, a torsional viscous damper was added to the leading edge spar-spine model to investigate the effect of damping on stability. Results show that for the un-damped case, the leading edge spar-spine response was stable and bounded; however, there were areas of instability that appear for a range of spine upstroke and downstroke stiffnesses. Results also show that there exist a damping ratio between 0.2 and 0.5, for which the leading edge spar-spine system was stable for all values of spine upstroke and downstroke stiffnesses.

  1. Turbine Airfoil Leading Edge Film Cooling Bibliography: 1972–1998

    Directory of Open Access Journals (Sweden)

    D. M. Kercher

    2000-01-01

    Full Text Available Film cooling for turbine airfoil leading edges has been a common practice for at least 35 years as turbine inlet gas temperatures and pressures have continually increased along with cooling air temperatures for higher engine cycle efficiency. With substantial engine cycle performance improvements from higher gas temperatures, it has become increasingly necessary to film cool nozzle and rotor blade leading edges since external heat transfer coefficients and thus heat load are the highest in this airfoil region. Optimum cooling air requirements in this harsh environment has prompted a significant number of film cooling investigations and analytical studies reported over the past 25 years from academia, industry and government agencies. Substantial progress has been made in understanding the complex nature of leading edge film cooling from airfoil cascades, simulated airfoil leading edges and environment. This bibliography is a report of the open-literature references available which provide information on the complex aero–thermo interaction of leading edge gaseous film cooling with mainstream flow. From much of this investigative information has come successful operational leading edge film cooling design systems capable of sustaining airfoil leading edge durability in very hostile turbine environments.

  2. Managed aquifer recharge: rediscovering nature as a leading edge technology.

    Science.gov (United States)

    Dillon, P; Toze, S; Page, D; Vanderzalm, J; Bekele, E; Sidhu, J; Rinck-Pfeiffer, S

    2010-01-01

    Use of Managed Aquifer Recharge (MAR) has rapidly increased in Australia, USA, and Europe in recent years as an efficient means of recycling stormwater or treated sewage effluent for non-potable and indirect potable reuse in urban and rural areas. Yet aquifers have been relied on knowingly for water storage and unwittingly for water treatment for millennia. Hence if 'leading edge' is defined as 'the foremost part of a trend; a vanguard', it would be misleading to claim managed aquifer recharge as a leading edge technology. However it has taken a significant investment in scientific research in recent years to demonstrate the effectiveness of aquifers as sustainable treatment systems to enable managed aquifer recharge to be recognised along side engineered treatment systems in water recycling. It is a 'cross-over' technology that is applicable to water and wastewater treatment and makes use of passive low energy processes to spectacularly reduce the energy requirements for water supply. It is robust within limits, has low cost, is suitable from village to city scale supplies, and offers as yet almost untapped opportunities for producing safe drinking water supplies where they do not yet exist. It will have an increasingly valued role in securing water supplies to sustain cities affected by climate change and population growth. However it is not a universal panacea and relies on the presence of suitable aquifers and sources of water together with effective governance to ensure human health and environment protection and water resources planning and management. This paper describes managed aquifer recharge, illustrates its use in Australia, outlining economics, guidelines and policies, and presents some of the knowledge about aquifer treatment processes that are revealing the latent value of aquifers as urban water infrastructure and provide a driver to improving our understanding of urban hydrogeology.

  3. Effect of nose bluntness on boundary layer stability and transition

    Science.gov (United States)

    Malik, M. R.; Spall, R. E.; Chang, C.-L.

    1990-01-01

    The effect of nose bluntness on boundary layer instability is studied theoretically for a Mach 8 flow past a 7 degree semivertex cone. The basic flow is computed by solving the parabolized Navier-Stokes equations. Linear stability analysis of the basic flow reveals that, with small amount of bluntness, the critical Reynolds number for the onset of instability increases by an order of magnitude compared to the sharp cone value. The computed second mode frequencies are also in reasonable agreement with the experimental results. The results are used to explain the effect of unit Reynolds number on transition present in the quiet aeroballistic range data.

  4. Structural Health Monitoring Analysis for the Orbiter Wing Leading Edge

    Science.gov (United States)

    Yap, Keng C.

    2010-01-01

    This viewgraph presentation reviews Structural Health Monitoring Analysis for the Orbiter Wing Leading Edge. The Wing Leading Edge Impact Detection System (WLE IDS) and the Impact Analysis Process are also described to monitor WLE debris threats. The contents include: 1) Risk Management via SHM; 2) Hardware Overview; 3) Instrumentation; 4) Sensor Configuration; 5) Debris Hazard Monitoring; 6) Ascent Response Summary; 7) Response Signal; 8) Distribution of Flight Indications; 9) Probabilistic Risk Analysis (PRA); 10) Model Correlation; 11) Impact Tests; 12) Wing Leading Edge Modeling; 13) Ascent Debris PRA Results; and 14) MM/OD PRA Results.

  5. Effects of imposed monitoring and blunting strategies on emotional reactivity

    NARCIS (Netherlands)

    Muris, Peter; Jong, de Peter; Merckelbach, Harald; van Zuuren, Florence J.

    1994-01-01

    The present study examined the effects of imposed monitoring and blunting coping strategies on emotional reactivity in 40 subjects who prepared themselves for upcoming neutral and aversive slides. Besides subjective indices, electrodermal measures and eye blink startle responses were used to

  6. A Combined CFD/Characteristic Method for Prediction and Design of Hypersonic Inlet with Nose Bluntness

    Science.gov (United States)

    Gao, Wenzhi; Li, Zhufei; Yang, Jiming

    Leading edge bluntness is widely used in hypersonic inlet design for thermal protection[1]. Detailed research of leading edge bluntness on hypersonic inlet has been concentrated on shock shape correlation[2], boundary layer flow[3], inlet performance[4], etc. It is well known that blunted noses cause detached bow shocks which generate subsonic regions around the noses and entropy layers in the flowfield.

  7. An analytically-based method for predicting the noise generated by the interaction between turbulence and a serrated leading edge

    Science.gov (United States)

    Mathews, J. R.; Peake, N.

    2018-05-01

    This paper considers the interaction of turbulence with a serrated leading edge. We investigate the noise produced by an aerofoil moving through a turbulent perturbation to uniform flow by considering the scattered pressure from the leading edge. We model the aerofoil as an infinite half plane with a leading edge serration, and develop an analytical model using a Green's function based upon the work of Howe. This allows us to consider both deterministic eddies and synthetic turbulence interacting with the leading edge. We show that it is possible to reduce the noise by using a serrated leading edge compared with a straight edge, but the optimal noise-reducing choice of serration is hard to predict due to the complex interaction. We also consider the effect of angle of attack, and find that in general the serrations are less effective at higher angles of attack.

  8. Rotary balance data for a typical single-engine general aviation design for an angle-of-attack range of 8 degrees to 35 degrees, 3. Effect of wing leading-edge modifications, model A

    Science.gov (United States)

    Bihrle, W., Jr.; Mulcay, W.

    1979-01-01

    Aerodynamic characteristics obtained in a rotational flow environment utilizing a rotary balance located in the Langley spin tunnel are presented in plotted form for a 1/5 scale, single-engine, low-wing, general aviation airplane model. The configurations tested included the basic airplane, sixteen wing leading-edge modifications and lateral-directional control settings. Data are presented for all configurations without analysis for an angle of attack range of 8 deg to 35 deg and clockwise and counter-clockwise rotations covering an Omega b/2v range from 0 to 0.85. Also, data are presented above 35 deg of attack for some configurations.

  9. Shuttle Wing Leading Edge Root Cause NDE Team Findings and Implementation of Quantitative Flash Infrared Thermography

    Science.gov (United States)

    Burke, Eric R.

    2009-01-01

    Comparison metrics can be established to reliably and repeatedly establish the health of the joggle region of the Orbiter Wing Leading Edge reinforced carbon carbon (RCC) panels. Using these metrics can greatly reduced the man hours needed to perform, wing leading edge scanning for service induced damage. These time savings have allowed for more thorough inspections to be preformed in the necessary areas with out affecting orbiter flow schedule. Using specialized local inspections allows for a larger margin of safety by allowing for more complete characterizations of panel defects. The presence of the t-seal during thermographic inspection can have adverse masking affects on ability properly characterize defects that exist in the joggle region of the RCC panels. This masking affect dictates the final specialized inspection should be preformed with the t-seal removed. Removal of the t-seal and use of the higher magnification optics has lead to the most effective and repeatable inspection method for characterizing and tracking defects in the wing leading edge. Through this study some inadequacies in the main health monitoring system for the orbiter wing leading edge have been identified and corrected. The use of metrics and local specialized inspection have lead to a greatly increased reliability and repeatable inspection of the shuttle wing leading edge.

  10. Development flight tests of JetStar LFC leading-edge flight test experiment

    Science.gov (United States)

    Fisher, David F.; Fischer, Michael C.

    1987-01-01

    The overall objective of the flight tests on the JetStar aircraft was to demonstrate the effectiveness and reliability of laminar flow control under representative flight conditions. One specific objective was to obtain laminar flow on the JetStar leading-edge test articles for the design and off-design conditions. Another specific objective was to obtain operational experience on a Laminar Flow Control (LFC) leading-edge system in a simulated airline service. This included operational experience with cleaning requirements, the effect of clogging, possible foreign object damage, erosion, and the effects of ice particle and cloud encounters. Results are summarized.

  11. Rotational accelerations stabilize leading edge vortices on revolving fly wings.

    Science.gov (United States)

    Lentink, David; Dickinson, Michael H

    2009-08-01

    The aerodynamic performance of hovering insects is largely explained by the presence of a stably attached leading edge vortex (LEV) on top of their wings. Although LEVs have been visualized on real, physically modeled, and simulated insects, the physical mechanisms responsible for their stability are poorly understood. To gain fundamental insight into LEV stability on flapping fly wings we expressed the Navier-Stokes equations in a rotating frame of reference attached to the wing's surface. Using these equations we show that LEV dynamics on flapping wings are governed by three terms: angular, centripetal and Coriolis acceleration. Our analysis for hovering conditions shows that angular acceleration is proportional to the inverse of dimensionless stroke amplitude, whereas Coriolis and centripetal acceleration are proportional to the inverse of the Rossby number. Using a dynamically scaled robot model of a flapping fruit fly wing to systematically vary these dimensionless numbers, we determined which of the three accelerations mediate LEV stability. Our force measurements and flow visualizations indicate that the LEV is stabilized by the ;quasi-steady' centripetal and Coriolis accelerations that are present at low Rossby number and result from the propeller-like sweep of the wing. In contrast, the unsteady angular acceleration that results from the back and forth motion of a flapping wing does not appear to play a role in the stable attachment of the LEV. Angular acceleration is, however, critical for LEV integrity as we found it can mediate LEV spiral bursting, a high Reynolds number effect. Our analysis and experiments further suggest that the mechanism responsible for LEV stability is not dependent on Reynolds number, at least over the range most relevant for insect flight (100wind turbines at much higher Reynolds numbers suggest that even large flying animals could potentially exploit LEV-based force augmentation during slow hovering flight, take-offs or landing

  12. Aerodynamic robustness in owl-inspired leading-edge serrations: a computational wind-gust model.

    Science.gov (United States)

    Rao, Chen; Liu, Hao

    2018-06-08

    Owls are a master to achieve silent flight in gliding and flapping flights under natural turbulent environments owing to their unique wing morphologies. While the leading-edge serrations are recently revealed, as a passive flow control micro-device, to play a crucial role in aerodynamic force production and sound suppression [25], the characteristics of wind-gust rejection associated with leading-edge serrations remain unclear. Here we address a large-eddy simulation (LES)-based study of aerodynamic robustness in owl-inspired leading-edge serrations, which is conducted with clean and serrated wing models through mimicking wind-gusts under a longitudinal fluctuation in free-stream inflow and a lateral fluctuation in pitch angle over a broad range of angles of attack (AoAs) over 0° ≤ Φ ≤ 20°. Our results show that the leading-edge serration-based passive flow control mechanisms associated with laminar-turbulent transition work effectively under fluctuated inflow and wing pitch, indicating that the leading-edge serrations are of potential gust fluctuation rejection or robustness in aerodynamic performance. Moreover, it is revealed that the tradeoff between turbulent flow control (i.e., aero-acoustic suppression) and force production in the serrated model holds independently to the wind-gust environments: poor at lower AoAs but capable of achieving equivalent aerodynamic performance at higher AoAs > 15o compared to the clean model. Our results reveal that the owl-inspired leading-edge serrations can be a robust micro-device for aero-acoustic control coping with unsteady and complex wind environments in biomimetic rotor designs for various fluid machineries. © 2018 IOP Publishing Ltd.

  13. Rotational accelerations stabilize leading edge vortices on revolving fly wings

    NARCIS (Netherlands)

    Lentink, D.; Dickinson, M.H.

    2009-01-01

    The aerodynamic performance of hovering insects is largely explained by the presence of a stably attached leading edge vortex (LEV) on top of their wings. Although LEVs have been visualized on real, physically modeled, and simulated insects, the physical mechanisms responsible for their stability

  14. A high-performance, low-cost, leading edge discriminator

    Indian Academy of Sciences (India)

    Abstract. A high-performance, low-cost, leading edge discriminator has been designed with a timing performance comparable to state-of-the-art, commercially available discrim- inators. A timing error of 16 ps is achieved under ideal operating conditions. Under more realistic operating conditions the discriminator displays a ...

  15. Leading-edge vortex shedding from rotating wings

    Energy Technology Data Exchange (ETDEWEB)

    Kolomenskiy, Dmitry [Centre de Recherches Mathématiques (CRM), Department of Mathematics and Statistics, McGill University, 805 Sherbrooke W., Montreal, QC H3A 0B9 (Canada); Elimelech, Yossef [Faculty of Aerospace Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Schneider, Kai, E-mail: dkolom@gmail.com [M2P2–CNRS, Université d' Aix-Marseille, 39, rue Frédéric Joliot-Curie, F-13453 Marseille Cedex 13 (France)

    2014-06-01

    This paper presents a numerical investigation of the leading-edge vortices generated by rotating triangular wings at Reynolds number Re = 250. A series of three-dimensional numerical simulations have been carried out using a Fourier pseudo-spectral method with volume penalization. The transition from stable attachment of the leading-edge vortex to periodic vortex shedding is explored, as a function of the wing aspect ratio and the angle of attack. It is found that, in a stable configuration, the spanwise flow in the recirculation bubble past the wing is due to the centrifugal force, incompressibility and viscous stresses. For the flow outside of the bubble, an inviscid model of spanwise flow is presented. (papers)

  16. Probabilistic Structural Health Monitoring of the Orbiter Wing Leading Edge

    Science.gov (United States)

    Yap, Keng C.; Macias, Jesus; Kaouk, Mohamed; Gafka, Tammy L.; Kerr, Justin H.

    2011-01-01

    A structural health monitoring (SHM) system can contribute to the risk management of a structure operating under hazardous conditions. An example is the Wing Leading Edge Impact Detection System (WLEIDS) that monitors the debris hazards to the Space Shuttle Orbiter s Reinforced Carbon-Carbon (RCC) panels. Since Return-to-Flight (RTF) after the Columbia accident, WLEIDS was developed and subsequently deployed on board the Orbiter to detect ascent and on-orbit debris impacts, so as to support the assessment of wing leading edge structural integrity prior to Orbiter re-entry. As SHM is inherently an inverse problem, the analyses involved, including those performed for WLEIDS, tend to be associated with significant uncertainty. The use of probabilistic approaches to handle the uncertainty has resulted in the successful implementation of many development and application milestones.

  17. Leading-Edge Velocities and Lifted Methane Jet Flame Stability

    Directory of Open Access Journals (Sweden)

    W. Wang

    2010-01-01

    Full Text Available Current interest exists in understanding reaction-zone dynamics and mechanisms with respect to how they counterpropagate against incoming reactants. Images of flame position and flow-field morphology are presented from flame chemiluminescence and particle image velocimetry (PIV measurements. In the present study, PIV experiments were carried out to measure the methane jet lifted-flame flow-field velocities in the vicinity of the flame leading edge. Specifically, velocity fields within the high-temperature zone were examined in detail, which complements previous studies, whose prime focus is the flow-field upstream of the high-temperature boundary. PIV data is used not only to determine the velocities, but, along with chemiluminescence images, to also indicate the approximate location of the reaction zone (further supported by/through the leading-edge flame velocity distributions. The velocity results indirectly support the concept that the flame is anchored primarily through the mechanism of partially premixed flame propagation.

  18. Ablative overlays for Space Shuttle leading edge ascent heat protection

    Science.gov (United States)

    Strauss, E. L.

    1975-01-01

    Ablative overlays were evaluated via a plasma-arc simulation of the ascent pulse on the leading edge of the Space Shuttle Orbiter. Overlay concepts included corkboard, polyisocyanurate foam, low-density Teflon, epoxy, and subliming salts. Their densities ranged from 4.9 to 81 lb per cu ft, and the thicknesses varied from 0.107 to 0.330 in. Swept-leading-edge models were fabricated from 30-lb per cu ft silicone-based ablators. The overlays were bonded to maintain the surface temperature of the base ablator below 500 F during ascent. Foams provided minimum-weight overlays, and subliming salts provided minimum-thickness overlays. Teflon left the most uniform surface after ascent heating.

  19. Design & fabrication of two seated aircraft with an advanced rotating leading edge wing

    Science.gov (United States)

    Al Ahmari, Saeed Abdullah Saeed

    The title of this thesis is "Design & Fabrication of two Seated Aircraft with an Advanced Rotating Leading Edge Wing", this gives almost a good description of the work has been done. In this research, the moving surface boundary-layer control (MSBC) concept was investigated and implemented. An experimental model was constructed and tested in wind tunnel to determine the aerodynamic characteristics using the leading edge moving surface of modified semi-symmetric airfoil NACA1214. The moving surface is provided by a high speed rotating cylinder, which replaces the leading edge of the airfoil. The angle of attack, the cylinder surfaces velocity ratio Uc/U, and the flap deflection angle effects on the lift and drag coefficients and the stall angle of attack were investigated. This new technology was applied to a 2-seat light-sport aircraft that is designed and built in the Aerospace Engineering Department at KFUPM. The project team is led by the aerospace department chairman Dr. Ahmed Z. AL-Garni and Dr. Wael G. Abdelrahman and includes graduate and under graduate student. The wing was modified to include a rotating cylinder along the leading edge of the flap portion. This produced very promising results such as the increase of the maximum lift coefficient at Uc/U=3 by 82% when flaps up and 111% when flaps down at 40° and stall was delayed by 8degrees in both cases. The laboratory results also showed that the effective range of the leading-edge rotating cylinder is at low angles of attack which reduce the need for higher angles of attack for STOL aircraft.

  20. The leading-edge vortex of yacht sails

    Science.gov (United States)

    Arredondo-Galeana, Abel; Viola, Ignazio Maria

    2017-11-01

    We experimentally show, for the first time, that a stable Leading-Edge Vortex (LEV) can be formed on an asymmetric spinnaker, which is a high-lift sail used by yachts to sail downwind. We tested a 3D printed rigid sail in a water flume at a chord-based Reynolds number of ca. 104. We found that on the leeward side of the sail (the suction side), the flow separates at the leading edge reattaching further downstream and forming a stable LEV. The LEV grows in diameter from the root to the tip of the sail, where it merges with the tip vortex. We detected the LEV using the γ criterion, and we verified its stability over time. The lift contribution provided by the LEV was computed solving a complex potential model of each sail section. This analysis indicated that the LEV provides a substantial contribution to the total sail's lift. These findings suggest that the maximum lift of low-aspect-ratio wings with a sharp leading edge, such as spinnakers, can be enhanced by promoting a stable LEV. This work was funded by the Consejo Nacional de Ciencia y Tecnologia (CONACYT).

  1. Leading-edge flow criticality as a governing factor in leading-edge vortex initiation in unsteady airfoil flows

    Science.gov (United States)

    Ramesh, Kiran; Granlund, Kenneth; Ol, Michael V.; Gopalarathnam, Ashok; Edwards, Jack R.

    2018-04-01

    A leading-edge suction parameter (LESP) that is derived from potential flow theory as a measure of suction at the airfoil leading edge is used to study initiation of leading-edge vortex (LEV) formation in this article. The LESP hypothesis is presented, which states that LEV formation in unsteady flows for specified airfoil shape and Reynolds number occurs at a critical constant value of LESP, regardless of motion kinematics. This hypothesis is tested and validated against a large set of data from CFD and experimental studies of flows with LEV formation. The hypothesis is seen to hold except in cases with slow-rate kinematics which evince significant trailing-edge separation (which refers here to separation leading to reversed flow on the aft portion of the upper surface), thereby establishing the envelope of validity. The implication is that the critical LESP value for an airfoil-Reynolds number combination may be calibrated using CFD or experiment for just one motion and then employed to predict LEV initiation for any other (fast-rate) motion. It is also shown that the LESP concept may be used in an inverse mode to generate motion kinematics that would either prevent LEV formation or trigger the same as per aerodynamic requirements.

  2. Turbine Airfoil With CMC Leading-Edge Concept Tested Under Simulated Gas Turbine Conditions

    Science.gov (United States)

    Robinson, R. Craig; Hatton, Kenneth S.

    2000-01-01

    metal vane was tested for a total of 150 cycles. Both the leading edge and trailing edge of the blade exhibited fatigue cracking and burn-through similar to the failures experienced in service by the F402 engine. Next, an airfoil, fitted with the ceramic leading edge insert, was exposed for 200 cycles. The temperature response of those HPBR cycles indicated a reduced internal metal temperature, by as much as 600 F at the midspan location for the same surface temperature (2100 F). After testing, the composite insert appeared intact, with no signs of failure on either the vane s leading or trailing edge. Only a slight oxide scale, as would be expected, was noted on the insert. Overall, the CMC insert performed similarly to a thick thermal barrier coating. With a small air gap between the metal and the SiC/SiC leading edge, heat transfer from the CMC to the metal alloy was low, effectively lowering the temperatures. The insert's performance has proven that an uncooled CMC can be engineered and designed to withstand the thermal up-shock experienced during the severe lift conditions in the Pegasus engine. The design of the leading-edge insert, which minimized thermal stresses in the SiC/SiC CMC, showed that the CMC/metal assembly can be engineered to be a functioning component.

  3. Periodic and aperiodic flow patterns around an airfoil with leading-edge protuberances

    Science.gov (United States)

    Cai, Chang; Zuo, Zhigang; Maeda, Takao; Kamada, Yasunari; Li, Qing'an; Shimamoto, Kensei; Liu, Shuhong

    2017-11-01

    Recently leading-edge protuberances have attracted great attention as a passive method for separation control. In this paper, the effect of multiple leading-edge protuberances on the performance of a two-dimensional airfoil is investigated through experimental measurement of aerodynamic forces, surface tuft visualization, and numerical simulation. In contrast to the sharp stall of the baseline airfoil with large hysteresis effect during AOA (angle of attack) increasing and decreasing, the stall process of the modified airfoil with leading-edge protuberances is gentle and stable. Flow visualization revealed that the flow past each protuberance is periodic and symmetric at small AOAs. Streamwise vortices are generated on the shoulders of the protuberance, leading to a larger separation around the valley sections and a longer attachment along the peak sections. When some critical AOA is exceeded, aperiodic and asymmetric flow patterns occur on the protuberances at different spanwise positions, with leading-edge separation on some of the valley sections and non-stalled condition elsewhere. A combined mechanism, involving both the compartmentalization effect of the slender momentum-enhanced attached flows on the protuberance peaks and the downwash effect of the local stalled region with low circulation, is proposed to explain the generation of the aperiodic flow patterns. The influence of the number of protuberances is also investigated, which shows similar aperiodic flow patterns. The distance between the neighboring local stalled valley sections is found to be in the range of 4-7 times the protuberance wavelength. According to the proposed mechanism, it is speculated that the distance between the neighboring local stalled valley sections is inclined to increase with a smaller protuberance amplitude or at a larger AOA.

  4. Numerical investigation of mist/air impingement cooling on ribbed blade leading-edge surface.

    Science.gov (United States)

    Bian, Qingfei; Wang, Jin; Chen, Yi-Tung; Wang, Qiuwang; Zeng, Min

    2017-12-01

    The working gas turbine blades are exposed to the environment of high temperature, especially in the leading-edge region. The mist/air two-phase impingement cooling has been adopted to enhance the heat transfer on blade surfaces and investigate the leading-edge cooling effectiveness. An Euler-Lagrange particle tracking method is used to simulate the two-phase impingement cooling on the blade leading-edge. The mesh dependency test has been carried out and the numerical method is validated based on the available experimental data of mist/air cooling with jet impingement on a concave surface. The cooling effectiveness on three target surfaces is investigated, including the smooth and the ribbed surface with convex/concave columnar ribs. The results show that the cooling effectiveness of the mist/air two-phase flow is better than that of the single-phase flow. When the ribbed surfaces are used, the heat transfer enhancement is significant, the surface cooling effectiveness becomes higher and the convex ribbed surface presents a better performance. With the enhancement of the surface heat transfer, the pressure drop in the impingement zone increases, but the incremental factor of the flow friction is smaller than that of the heat transfer enhancement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Leading edge analysis of transcriptomic changes during pseudorabies virus infection

    Directory of Open Access Journals (Sweden)

    Damarius S. Fleming

    2016-12-01

    Full Text Available Eight RNA samples taken from the tracheobronchial lymph nodes (TBLN of pigs that were either infected or non-infected with a feral isolate of porcine pseudorabies virus (PRV were used to investigate changes in gene expression related to the pathogen. The RNA was processed into fastq files for each library prior to being analyzed using Illumina Digital Gene Expression Tag Profiling sequences (DGETP which were used as the downstream measure of differential expression. Analyzed tags consisted of 21 base pair sequences taken from time points 1, 3, 6, and 14 days' post infection (dpi that generated 1,927,547 unique tag sequences. Tag sequences were analyzed for differential transcript expression and gene set enrichment analysis (GSEA to uncover transcriptomic changes related to PRV pathology progression. In conjunction with the DGETP and GSEA, the study also incorporated use of leading edge analysis to help link the TBLN transcriptome data to clinical progression of PRV at each of the sampled time points. The purpose of this manuscript is to provide useful background on applying the leading edge analysis to GSEA and expression data to help identify genes considered to be of high biological interest. The data in the form of fastq files has been uploaded to the NCBI Gene Expression Omnibus (GEO (GSE74473 database.

  6. Leading edge analysis of transcriptomic changes during pseudorabies virus infection.

    Science.gov (United States)

    Fleming, Damarius S; Miller, Laura C

    2016-12-01

    Eight RNA samples taken from the tracheobronchial lymph nodes (TBLN) of pigs that were either infected or non-infected with a feral isolate of porcine pseudorabies virus (PRV) were used to investigate changes in gene expression related to the pathogen. The RNA was processed into fastq files for each library prior to being analyzed using Illumina Digital Gene Expression Tag Profiling sequences (DGETP) which were used as the downstream measure of differential expression. Analyzed tags consisted of 21 base pair sequences taken from time points 1, 3, 6, and 14 days' post infection (dpi) that generated 1,927,547 unique tag sequences. Tag sequences were analyzed for differential transcript expression and gene set enrichment analysis (GSEA) to uncover transcriptomic changes related to PRV pathology progression. In conjunction with the DGETP and GSEA, the study also incorporated use of leading edge analysis to help link the TBLN transcriptome data to clinical progression of PRV at each of the sampled time points. The purpose of this manuscript is to provide useful background on applying the leading edge analysis to GSEA and expression data to help identify genes considered to be of high biological interest. The data in the form of fastq files has been uploaded to the NCBI Gene Expression Omnibus (GEO) (GSE74473) database.

  7. A fence barrier method of leading edge cell capture for explorative biochemical research.

    Science.gov (United States)

    Wager, Lucas J; Murray, Rachael Z; Thompson, Erik W; Leavesley, David I

    2017-09-03

    The scratch or wound-healing assay is used ubiquitously for investigating re-epithelialisation and has already revealed the importance of cells comprising the leading edge of healing epithelial wounds. However it is currently limited to studying the effect of known biochemical agents on the tissue of choice. Here we present an adaptation that extends the utility of this model to encompass the collection of cells from the leading edge of migrating epithelial sheets making available explorative biochemical analyses. The method is scalable and does not require expensive apparatus, making it suitable for large and small laboratories alike. We detail the application of our method and exemplify proof of principle data derived from primary human keratinocyte cultures.

  8. Method for a Leading Edge Slat on a Wing of an Aircraft

    Science.gov (United States)

    Pitt, Dale M. (Inventor); Eckstein, Nicholas Stephen (Inventor)

    2016-01-01

    A method for managing a flight control surface system. A leading edge device is moved on a leading edge from an undeployed position to a deployed position. The leading edge device has an outer surface, an inner surface, and a deformable fairing attached to the leading edge device such that the deformable fairing covers at least a portion of the inner surface. The deformable fairing changes from a deformed shape to an original shape when the leading edge device is moved to the deployed position. The leading edge device is then moved from the deployed position to the undeployed position, wherein the deformable fairing changes from the original shape to the deformed shape.

  9. The leading-edge vortex of swift-wing shaped delta wings

    Science.gov (United States)

    Muir, Rowan; Arredondo-Galeana, Abel; Viola, Ignazio Maria

    2017-11-01

    Recent investigations on the aerodynamics of natural fliers have illuminated the significance of the Leading-Edge Vortex (LEV) for lift generation in a variety of flight conditions. In this investigation, a model non-slender delta shaped wing with a sharp leading-edge is tested at low Reynolds Number, along with a delta wing of the same design, but with a modified trailing edge inspired by the wing of a common swift Apus apus. The effect of the tapering swift wing on LEV development and stability is compared with the flow structure over the un-modified delta wing model through particle image velocimetry. For the first time, a leading-edge vortex system consisting of a dual or triple LEV is recorded on a swift-wing shaped delta wing, where such a system is found across all tested conditions. It is shown that the spanwise location of LEV breakdown is governed by the local chord rather than Reynolds Number or angle of attack. These findings suggest that the trailing-edge geometry of the swift wing alone does not prevent the common swift from generating an LEV system comparable with that of a delta shaped wing. This work received funding from the Engineering and Physical Sciences Research Council [EP/M506515/1] and the Consejo Nacional de Ciencia y Tecnología (CONACYT).

  10. Flexible Plug Repair for Shuttle Wing Leading Edge

    Science.gov (United States)

    Camarda, Charles J.; Sikora, Joseph; Smith, Russel; Rivers, H.; Scotti, Stephen J.; Fuller, Alan M.; Klacka, Robert; Reinders, Martin; Schwind, Francis; Sullivan, Brian; hide

    2012-01-01

    In response to the Columbia Accident Investigation Board report, a plug repair kit has been developed to enable astronauts to repair the space shuttle's wing leading edge (WLE) during orbit. The plug repair kit consists of several 17.78- cm-diameter carbon/silicon carbide (C/SiC) cover plates of various curvatures that can be attached to the refractory carbon-carbon WLE panels using a TZM refractory metal attach mechanism. The attach mechanism is inserted through the damage in the WLE panel and, as it is tightened, the cover plate flexes to conform to the curvature of the WLE panel within 0.050 mm. An astronaut installs the repair during an extravehicular activity (EVA). After installing the plug repair, edge gaps are checked and the perimeter of the repair is sealed using a proprietary material, developed to fill cracks and small holes in the WLE.

  11. Impact of Leading-Edge Orientation and Shape on Performance of Compressor Blades

    National Research Council Canada - National Science Library

    Powell, Jonathan D

    2005-01-01

    This thesis presents a Computation Fluid Dynamics (CFD) analysis of the aerodynamic performance of circular and elliptical leading edges of compressor blades, with a range of leading edge droop angles...

  12. Effects of Chemistry on Blunt-Body Wake Structure

    Science.gov (United States)

    Dogra, Virendra K.; Moss, James N.; Wilmoth, Richard G.; Taylor, Jeff C.; Hassan, H. A.

    1995-01-01

    Results of a numerical study are presented for hypersonic low-density flow about a 70-deg blunt cone using direct simulation Monte Carlo (DSMC) and Navier-Stokes calculations. Particular emphasis is given to the effects of chemistry on the near-wake structure and on the surface quantities and the comparison of the DSMC results with the Navier-Stokes calculations. The flow conditions simulated are those experienced by a space vehicle at an altitude of 85 km and a velocity of 7 km/s during Earth entry. A steady vortex forms in the near wake for these freestream conditions for both chemically reactive and nonreactive air gas models. The size (axial length) of the vortex for the reactive air calculations is 25% larger than that of the nonreactive air calculations. The forebody surface quantities are less sensitive to the chemistry than the base surface quantities. The presence of the afterbody has no effect on the forebody flow structure or the surface quantities. The comparisons of DSMC and Navier-Stokes calculations show good agreement for the wake structure and the forebody surface quantities.

  13. Mechanisms of leading edge protrusion in interstitial migration

    Science.gov (United States)

    Wilson, Kerry; Lewalle, Alexandre; Fritzsche, Marco; Thorogate, Richard; Duke, Tom; Charras, Guillaume

    2013-01-01

    While the molecular and biophysical mechanisms underlying cell protrusion on two-dimensional substrates are well understood, our knowledge of the actin structures driving protrusion in three-dimensional environments is poor, despite relevance to inflammation, development and cancer. Here we report that, during chemotactic migration through microchannels with 5 μm × 5 μm cross-sections, HL60 neutrophil-like cells assemble an actin-rich slab filling the whole channel cross-section at their front. This leading edge comprises two distinct F-actin networks: an adherent network that polymerizes perpendicular to cell-wall interfaces and a ‘free’ network that grows from the free membrane at the cell front. Each network is polymerized by a distinct nucleator and, due to their geometrical arrangement, the networks interact mechanically. On the basis of our experimental data, we propose that, during interstitial migration, medial growth of the adherent network compresses the free network preventing its retrograde movement and enabling new polymerization to be converted into forward protrusion. PMID:24305616

  14. The Effect of Sarcopenia on Outcomes in Geriatric Blunt Trauma.

    Science.gov (United States)

    Malekpour, Mahdi; Bridgham, Kelly; Jaap, Kathryn; Erwin, Ryan; Widom, Kenneth; Rapp, Megan; Leonard, Diane; Baro, Susan; Dove, James; Hunsinger, Marie; Blansfield, Joseph; Shabahang, Mohsen; Torres, Denise; Wild, Jeffrey

    2017-11-01

    Elderly patients are at a higher risk of morbidity and mortality after trauma, which is reflected through higher frailty indices. Data collection using existing frailty indices is often not possible because of brain injury, dementia, or inability to communicate with the patient. Sarcopenia is a reliable objective measure for frailty that can be readily assessed in CT imaging. In this study, we aimed to evaluate the effect of sarcopenia on the outcomes of geriatric blunt trauma patients. Left psoas area (LPA) was measured at the level of the third lumbar vertebra on the axial CT images. LPA was normalized for height (LPA mm2/m2) and after stratification by gender, sarcopenia was defined as LPA measurements in the lowest quartile. A total of 1175 patients consisting of 597 males and 578 females were studied. LPAs below 242.6 mm2/m2 in males and below 187.8 mm2/m2 in females were considered to be sarcopenic. We found sarcopenia in 149 males and 145 females. In multivariate analysis, sarcopenia was associated with a higher risk of in-hospital mortality (odds ratio [OR]: 1.61, 95% confidence interval [CI]: 1.01-2.56) and a higher risk of discharge to less favorable destinations (OR: 1.42, 95% CI: 1.05-1.97). Lastly, sarcopenic patients had an increased risk of prolonged hospitalization (hazard ratio: 1.21, 95% CI: 1.04-1.40).

  15. The effect of resuscitation strategy on the longitudinal immuno-inflammatory response to blunt trauma

    DEFF Research Database (Denmark)

    Bonde, Alexander; Nordestgaard, Ask Tybjærg; Kirial, Rasmus

    2017-01-01

    INTRODUCTION: Resuscitation strategies following blunt trauma have been linked to immuno-inflammatory complications leading to systemic inflammatory syndrome (SIRS), sepsis and multiple organ failure (MOF). The effect of resuscitation strategy on longitudinal inflammation marker trajectories is...

  16. Morphological Variations of Leading-Edge Serrations in Owls (Strigiformes.

    Directory of Open Access Journals (Sweden)

    Matthias Weger

    Full Text Available Owls have developed serrations, comb-like structures, along the leading edge of their wings. Serrations were investigated from a morphological and a mechanical point of view, but were not yet quantitatively compared for different species. Such a comparative investigation of serrations from species of different sizes and activity patterns may provide new information about the function of the serrations.Serrations on complete wings and on tenth primary remiges of seven owl species were investigated. Small, middle-sized, and large owl species were investigated as well as species being more active during the day and owls being more active during the night. Serrations occurred at the outer parts of the wings, predominantly at tenth primary remiges, but also on further wing feathers in most species. Serration tips were oriented away from the feather rachis so that they faced into the air stream during flight. The serrations of nocturnal owl species were higher developed as demonstrated by a larger inclination angle (the angle between the base of the barb and the rachis, a larger tip displacement angle (the angle between the tip of the serration and the base of the serration and a longer length. Putting the measured data into a clustering algorithm yielded dendrograms that suggested a strong influence of activity pattern, but only a weak influence of size on the development of the serrations.Serrations are supposed to be involved in noise reduction during flight and also depend on the aerodynamic properties that in turn depend on body size. Since especially nocturnal owls have to rely on hearing during prey capture, the more pronounced serrations of nocturnal species lend further support to the notion that serrations have an important function in noise reduction. The differences in shape of the serrations investigated indicate that a silent flight requires well-developed serrations.

  17. Morphological Variations of Leading-Edge Serrations in Owls (Strigiformes)

    Science.gov (United States)

    Weger, Matthias; Wagner, Hermann

    2016-01-01

    Background Owls have developed serrations, comb-like structures, along the leading edge of their wings. Serrations were investigated from a morphological and a mechanical point of view, but were not yet quantitatively compared for different species. Such a comparative investigation of serrations from species of different sizes and activity patterns may provide new information about the function of the serrations. Results Serrations on complete wings and on tenth primary remiges of seven owl species were investigated. Small, middle-sized, and large owl species were investigated as well as species being more active during the day and owls being more active during the night. Serrations occurred at the outer parts of the wings, predominantly at tenth primary remiges, but also on further wing feathers in most species. Serration tips were oriented away from the feather rachis so that they faced into the air stream during flight. The serrations of nocturnal owl species were higher developed as demonstrated by a larger inclination angle (the angle between the base of the barb and the rachis), a larger tip displacement angle (the angle between the tip of the serration and the base of the serration) and a longer length. Putting the measured data into a clustering algorithm yielded dendrograms that suggested a strong influence of activity pattern, but only a weak influence of size on the development of the serrations. Conclusions Serrations are supposed to be involved in noise reduction during flight and also depend on the aerodynamic properties that in turn depend on body size. Since especially nocturnal owls have to rely on hearing during prey capture, the more pronounced serrations of nocturnal species lend further support to the notion that serrations have an important function in noise reduction. The differences in shape of the serrations investigated indicate that a silent flight requires well-developed serrations. PMID:26934104

  18. The leading-edge vortex of swift wing-shaped delta wings.

    Science.gov (United States)

    Muir, Rowan Eveline; Arredondo-Galeana, Abel; Viola, Ignazio Maria

    2017-08-01

    Recent investigations on the aerodynamics of natural fliers have illuminated the significance of the leading-edge vortex (LEV) for lift generation in a variety of flight conditions. A well-documented example of an LEV is that generated by aircraft with highly swept, delta-shaped wings. While the wing aerodynamics of a manoeuvring aircraft, a bird gliding and a bird in flapping flight vary significantly, it is believed that this existing knowledge can serve to add understanding to the complex aerodynamics of natural fliers. In this investigation, a model non-slender delta-shaped wing with a sharp leading edge is tested at low Reynolds number, along with a delta wing of the same design, but with a modified trailing edge inspired by the wing of a common swift Apus apus . The effect of the tapering swift wing on LEV development and stability is compared with the flow structure over the unmodified delta wing model through particle image velocimetry. For the first time, a leading-edge vortex system consisting of a dual or triple LEV is recorded on a swift wing-shaped delta wing, where such a system is found across all tested conditions. It is shown that the spanwise location of LEV breakdown is governed by the local chord rather than Reynolds number or angle of attack. These findings suggest that the trailing-edge geometry of the swift wing alone does not prevent the common swift from generating an LEV system comparable with that of a delta-shaped wing.

  19. The Houdini effect--an unusual case of blunt abdominal trauma resulting in perforative appendicitis.

    LENUS (Irish Health Repository)

    O'Kelly, F

    2012-03-01

    We present a unique case of perforative appendicitis that occurred in an adult following blunt abdominal trauma. This case represents the first such reported case from Ireland. It also represents a modern practical example of Laplace\\'s theory of the effect of increased pressure on colonic wall tension leading to localized perforation, and serves to highlight not only the importance in preoperative imaging for blunt abdominal trauma, but also the importance of considering appendiceal perforation.

  20. Experimental investigation of wavy leading edges on rod-aerofoil interaction noise

    Science.gov (United States)

    Chen, Weijie; Qiao, Weiyang; Tong, Fan; Wang, Liangfeng; Wang, Xunnian

    2018-05-01

    Experimental studies are performed to investigate the effect of wavy leading edges on rod-aerofoil interaction noise in an open-jet anechoic wind tunnel. NACA 0012 aerofoils with straight and wavy leading edges (denoted by SLE and WLE, respectively) are embedded in the wake of a circular rod. The WLEs are in the form of sinusoidal profiles of amplitude, A, and wavelength, W. Parametric studies of the amplitude and wavelength characteristics are conducted to understand the effect of WLEs on noise reduction. It is observed that the sound power reduction level is sensitive to both the amplitude and wavelength of the WLEs. The WLE with the largest amplitude and smallest wavelength can achieve the most considerable noise reduction effect of up to 4 dB. The influences of rod diameter, d, and free-stream velocity, U0, on the noise reduction effect of the WLEs are also investigated. In addition, a parametric study of the influence of separating rod-aerofoil distance on the acoustic radiation of the SLE case and on the sound power reduction level of the WLE cases is performed. It is found that a critical spacing exists where the acoustic radiation and noise reduction can be divided into two different "modes".

  1. Method and Apparatus for a Leading Edge Slat on a Wing of an Aircraft

    Science.gov (United States)

    Pitt, Dale M. (Inventor); Eckstein, Nicholas Stephen (Inventor)

    2013-01-01

    A method and apparatus for managing a flight control surface system. A leading edge device is moved on a leading edge from an undeployed position to a deployed position. The leading edge device has an outer surface, an inner surface, and a deformable fairing attached to the leading edge device such that the deformable fairing covers at least a portion of the inner surface. The deformable fairing changes from a deformed shape to an original shape when the leading edge device is moved to the deployed position. The leading edge device is then moved from the deployed position to the undeployed position, wherein the deformable fairing changes from the original shape to the deformed shape.

  2. Numerical simulation of flow characteristics behind the aerodynamic performances on an airfoil with leading edge protuberances

    Directory of Open Access Journals (Sweden)

    Ming Zhao

    2017-01-01

    Full Text Available This article presents a numerical investigation of the effects of leading-edge protuberances on airfoil stall and post-stall performance. An improved delayed detached eddy simulation (IDDES method was adopted. As a result, to clarify the effects of ‘bi-periodic’ phenomenon around stall region, it was found that the flow separation at troughs was the main inducement of aerodynamic lift degradation within pre-stall regime and the flow pattern where vortices diverged was predominant. It was also found that the variations in flow patterns led to the gentle stall process. Furthermore, to study the statistical characteristics of unsteady vortex shedding, corresponding spectrum characteristics were also analyzed from another perspective, suggesting that the vortex shedding frequency was higher where vortices converged. Eventually, the improved performances of tubercled airfoil within post-stall regime could be attributed to the strong streamwise vortices generated by the leading-edge protuberances. Deploying the methods of vortex dynamics, the generation and evolution of the streamwise vortices were depicted. It turned out that the primary and secondary vortices were induced by spanwise pressure gradient at airfoil surface; meanwhile, vortex stretching played a key role in primary vortex evolution, which initially enhanced the strength of vortices corresponding to the acceleration of streamwise velocity.

  3. What is the critical height of leading edge roughness for aerodynamics?

    DEFF Research Database (Denmark)

    Bak, Christian; Gaunaa, Mac; Olsen, Anders Smærup

    2016-01-01

    -C2-18 and at three different Reynolds numbers with two different leading edge roughness tape heights. Firstly, an analysis of the momentum thickness as function of Reynolds number was carried out based on the boundary layer theory by Thwaites. Secondly, the wind tunnel measurements combined......In this paper the critical leading edge roughness height is analyzed in two cases: 1) leading edge roughness influencing the lift-drag ratio and 2) leading edge roughness influencing the maximum lift. The analysis was based on wind tunnel measurements on the airfoils NACA0015, Risoe-B1-18 and Risoe...

  4. Fabrication of lithium/C-103 alloy heat pipes for sharp leading edge cooling

    Science.gov (United States)

    Ai, Bangcheng; Chen, Siyuan; Yu, Jijun; Lu, Qin; Han, Hantao; Hu, Longfei

    2018-05-01

    In this study, lithium/C-103 alloys heat pipes are proposed for sharp leading edge cooling. Three models of lithium/C-103 alloy heat pipes were fabricated. And their startup properties were tested by radiant heat tests and aerothermal tests. It is found that the startup temperature of lithium heat pipe was about 860 °C. At 1000 °C radiant heat tests, the operating temperature of lithium/C-103 alloy heat pipe is lower than 860 °C. Thus, startup failure occurs. At 1100 °C radiant heat tests and aerothermal tests, the operating temperature of lithium/C-103 alloy heat pipe is higher than 860 °C, and the heat pipe starts up successfully. The startup of lithium/C-103 alloy heat pipe decreases the leading edge temperature effectively, which endows itself good ablation resistance. After radiant heat tests and aerothermal tests, all the heat pipe models are severely oxidized because of the C-103 poor oxidation resistance. Therefore, protective coatings are required for further applications of lithium/C-103 alloy heat pipes.

  5. Case Studies of Leading Edge Small Urban High Schools. Relevance Strategic Designs: 4. Boston Arts Academy

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  6. Case Studies of Leading Edge Small Urban High Schools. Relevance Strategic Designs: 6. Perspectives Charter School

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  7. Topology optimization of compliant adaptive wing leading edge with composite materials

    Directory of Open Access Journals (Sweden)

    Tong Xinxing

    2014-12-01

    Full Text Available An approach for designing the compliant adaptive wing leading edge with composite material is proposed based on the topology optimization. Firstly, an equivalent constitutive relationship of laminated glass fiber reinforced epoxy composite plates has been built based on the symmetric laminated plate theory. Then, an optimization objective function of compliant adaptive wing leading edge was used to minimize the least square error (LSE between deformed curve and desired aerodynamics shape. After that, the topology structures of wing leading edge of different glass fiber ply-orientations were obtained by using the solid isotropic material with penalization (SIMP model and sensitivity filtering technique. The desired aerodynamics shape of compliant adaptive wing leading edge was obtained based on the proposed approach. The topology structures of wing leading edge depend on the glass fiber ply-orientation. Finally, the corresponding morphing experiment of compliant wing leading edge with composite materials was implemented, which verified the morphing capability of topology structure and illustrated the feasibility for designing compliant wing leading edge. The present paper lays the basis of ply-orientation optimization for compliant adaptive wing leading edge in unmanned aerial vehicle (UAV field.

  8. Modulation of leading edge vorticity and aerodynamic forces in flexible flapping wings.

    Science.gov (United States)

    Zhao, Liang; Deng, Xinyan; Sane, Sanjay P

    2011-09-01

    In diverse biological flight systems, the leading edge vortex has been implicated as a flow feature of key importance in the generation of flight forces. Unlike fixed wings, flapping wings can translate at higher angles of attack without stalling because their leading edge vorticity is more stable than the corresponding fixed wing case. Hence, the leading edge vorticity has often been suggested as the primary determinant of the high forces generated by flapping wings. To test this hypothesis, it is necessary to modulate the size and strength of the leading edge vorticity independently of the gross kinematics while simultaneously monitoring the forces generated by the wing. In a recent study, we observed that forces generated by wings with flexible trailing margins showed a direct dependence on the flexural stiffness of the wing. Based on that study, we hypothesized that trailing edge flexion directly influences leading edge vorticity, and thereby the magnitude of aerodynamic forces on the flexible flapping wings. To test this hypothesis, we visualized the flows on wings of varying flexural stiffness using a custom 2D digital particle image velocimetry system, while simultaneously monitoring the magnitude of the aerodynamic forces. Our data show that as flexion decreases, the magnitude of the leading edge vorticity increases and enhances aerodynamic forces, thus confirming that the leading edge vortex is indeed a key feature for aerodynamic force generation in flapping flight. The data shown here thus support the hypothesis that camber influences instantaneous aerodynamic forces through modulation of the leading edge vorticity.

  9. A PKC-MARCKS-PI3K regulatory module links Ca2+ and PIP3 signals at the leading edge of polarized macrophages.

    Science.gov (United States)

    Ziemba, Brian P; Falke, Joseph J

    2018-01-01

    The leukocyte chemosensory pathway detects attractant gradients and directs cell migration to sites of inflammation, infection, tissue damage, and carcinogenesis. Previous studies have revealed that local Ca2+ and PIP3 signals at the leading edge of polarized leukocytes play central roles in positive feedback loop essential to cell polarization and chemotaxis. These prior studies showed that stimulation of the leading edge Ca2+ signal can strongly activate PI3K, thereby triggering a larger PIP3 signal, but did not elucidate the mechanistic link between Ca2+ and PIP3 signaling. A hypothesis explaining this link emerged, postulating that Ca2+-activated PKC displaces the MARCKS protein from plasma membrane PIP2, thereby releasing sequestered PIP2 to serve as the target and substrate lipid of PI3K in PIP3 production. In vitro single molecule studies of the reconstituted pathway on lipid bilayers demonstrated the feasibility of this PKC-MARCKS-PI3K regulatory module linking Ca2+ and PIP3 signals in the reconstituted system. The present study tests the model predictions in live macrophages by quantifying the effects of: (a) two pathway activators-PDGF and ATP that stimulate chemoreceptors and Ca2+ influx, respectively; and (b) three pathway inhibitors-wortmannin, EGTA, and Go6976 that inhibit PI3K, Ca2+ influx, and PKC, respectively; on (c) four leading edge activity sensors-AKT-PH-mRFP, CKAR, MARCKSp-mRFP, and leading edge area that report on PIP3 density, PKC activity, MARCKS membrane binding, and leading edge expansion/contraction, respectively. The results provide additional evidence that PKC and PI3K are both essential elements of the leading edge positive feedback loop, and strongly support the existence of a PKC-MARCKS-PI3K regulatory module linking the leading edge Ca2+ and PIP3 signals. As predicted, activators stimulate leading edge PKC activity, displacement of MARCKS from the leading edge membrane and increased leading edge PIP3 levels, while inhibitors

  10. A PKC-MARCKS-PI3K regulatory module links Ca2+ and PIP3 signals at the leading edge of polarized macrophages.

    Directory of Open Access Journals (Sweden)

    Brian P Ziemba

    Full Text Available The leukocyte chemosensory pathway detects attractant gradients and directs cell migration to sites of inflammation, infection, tissue damage, and carcinogenesis. Previous studies have revealed that local Ca2+ and PIP3 signals at the leading edge of polarized leukocytes play central roles in positive feedback loop essential to cell polarization and chemotaxis. These prior studies showed that stimulation of the leading edge Ca2+ signal can strongly activate PI3K, thereby triggering a larger PIP3 signal, but did not elucidate the mechanistic link between Ca2+ and PIP3 signaling. A hypothesis explaining this link emerged, postulating that Ca2+-activated PKC displaces the MARCKS protein from plasma membrane PIP2, thereby releasing sequestered PIP2 to serve as the target and substrate lipid of PI3K in PIP3 production. In vitro single molecule studies of the reconstituted pathway on lipid bilayers demonstrated the feasibility of this PKC-MARCKS-PI3K regulatory module linking Ca2+ and PIP3 signals in the reconstituted system. The present study tests the model predictions in live macrophages by quantifying the effects of: (a two pathway activators-PDGF and ATP that stimulate chemoreceptors and Ca2+ influx, respectively; and (b three pathway inhibitors-wortmannin, EGTA, and Go6976 that inhibit PI3K, Ca2+ influx, and PKC, respectively; on (c four leading edge activity sensors-AKT-PH-mRFP, CKAR, MARCKSp-mRFP, and leading edge area that report on PIP3 density, PKC activity, MARCKS membrane binding, and leading edge expansion/contraction, respectively. The results provide additional evidence that PKC and PI3K are both essential elements of the leading edge positive feedback loop, and strongly support the existence of a PKC-MARCKS-PI3K regulatory module linking the leading edge Ca2+ and PIP3 signals. As predicted, activators stimulate leading edge PKC activity, displacement of MARCKS from the leading edge membrane and increased leading edge PIP3 levels, while

  11. CFD study on NACA 4415 airfoil implementing spherical and sinusoidal Tubercle Leading Edge.

    Science.gov (United States)

    Aftab, S M A; Ahmad, K A

    2017-01-01

    The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE) effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD) study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c), the wavelength (0.25c) is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil.

  12. Next-generation science information network for leading-edge applications

    International Nuclear Information System (INIS)

    Urushidani, S.; Matsukata, J.

    2008-01-01

    High-speed networks are definitely essential tools for leading-edge applications in many research areas, including nuclear fusion research. This paper describes a number of advanced features in the Japanese next-generation science information network, called SINET3, and gives researchers clues on the uses of advanced high-speed network for their applications. The network services have four categories, multiple layer transfer, enriched virtual private network, enhanced quality-of-service, and bandwidth on demand services, and comprise a versatile service platform. The paper also describes the network architecture and advanced networking capabilities that enable economical service accommodation and flexible network resource assignment as well as effective use of Japan's first 40-Gbps lines

  13. Next-generation science information network for leading-edge applications

    Energy Technology Data Exchange (ETDEWEB)

    Urushidani, S. [National Institute of Informatics, 2-1-2 Hitotsubashi Chiyoda-ku, Tokyo 101-8430 (Japan)], E-mail: urushi@nii.ac.jp; Matsukata, J. [National Institute of Informatics, 2-1-2 Hitotsubashi Chiyoda-ku, Tokyo 101-8430 (Japan)

    2008-04-15

    High-speed networks are definitely essential tools for leading-edge applications in many research areas, including nuclear fusion research. This paper describes a number of advanced features in the Japanese next-generation science information network, called SINET3, and gives researchers clues on the uses of advanced high-speed network for their applications. The network services have four categories, multiple layer transfer, enriched virtual private network, enhanced quality-of-service, and bandwidth on demand services, and comprise a versatile service platform. The paper also describes the network architecture and advanced networking capabilities that enable economical service accommodation and flexible network resource assignment as well as effective use of Japan's first 40-Gbps lines.

  14. MHD forced and free convection boundary layer flow near the leading edge

    International Nuclear Information System (INIS)

    Hossain, M.A.; Ahmed, M.

    1988-07-01

    Magnetohydrodynamic forced and free convection flow of an electrically conducting viscous incompressible fluid past a vertical flat plate with uniform heat flux in the presence of a magnetic field acting normal to the plate that moves with the fluid has been studied near the leading edge of the plate. The coupled non-linear equations are solved by the method of superposition for the values of the Prandtl number ranges from 0.01 to 10.0. The velocity and the temperature profiles are presented graphically and the values of the wall shear-stress as well as the heat transfer rate are presented in tabular form showing the effect of the buoyancy force and the applied magnetic field. To show the accuracy of the present method some typical values are compared with the available one. (author). 17 refs, 3 figs, 2 tabs

  15. An empirically-based model for the lift coefficients of twisted airfoils with leading-edge tubercles

    Science.gov (United States)

    Ni, Zao; Su, Tsung-chow; Dhanak, Manhar

    2018-04-01

    Experimental data for untwisted airfoils are utilized to propose a model for predicting the lift coefficients of twisted airfoils with leading-edge tubercles. The effectiveness of the empirical model is verified through comparison with results of a corresponding computational fluid-dynamic (CFD) study. The CFD study is carried out for both twisted and untwisted airfoils with tubercles, the latter shown to compare well with available experimental data. Lift coefficients of twisted airfoils predicted from the proposed empirically-based model match well with the corresponding coefficients determined using the verified CFD study. Flow details obtained from the latter provide better insight into the underlying mechanism and behavior at stall of twisted airfoils with leading edge tubercles.

  16. Streamwise counter-rotating vortices generated by triangular leading edge pattern in flat plate boundary layer

    KAUST Repository

    Hasheminejad, S. M.; Mitsudharmadi, Hatsari; Winoto, S. H.; Lua, K. B.; Low, H. T.

    2016-01-01

    A series of flow visualizations were conducted to qualitatively study the development of streamwise counter-rotating vortices over a flat plate induced by triangular patterns at the leading edge of a flat plate. The experiments were carried out

  17. Hypersonic Engine Leading Edge Experiments in a High Heat Flux, Supersonic Flow Environment

    Science.gov (United States)

    Gladden, Herbert J.; Melis, Matthew E.

    1994-01-01

    A major concern in advancing the state-of-the-art technologies for hypersonic vehicles is the development of an aeropropulsion system capable of withstanding the sustained high thermal loads expected during hypersonic flight. Three aerothermal load related concerns are the boundary layer transition from laminar to turbulent flow, articulating panel seals in high temperature environments, and strut (or cowl) leading edges with shock-on-shock interactions. A multidisciplinary approach is required to address these technical concerns. A hydrogen/oxygen rocket engine heat source has been developed at the NASA Lewis Research Center as one element in a series of facilities at national laboratories designed to experimentally evaluate the heat transfer and structural response of the strut (or cowl) leading edge. A recent experimental program conducted in this facility is discussed and related to cooling technology capability. The specific objective of the experiment discussed is to evaluate the erosion and oxidation characteristics of a coating on a cowl leading edge (or strut leading edge) in a supersonic, high heat flux environment. Heat transfer analyses of a similar leading edge concept cooled with gaseous hydrogen is included to demonstrate the complexity of the problem resulting from plastic deformation of the structures. Macro-photographic data from a coated leading edge model show progressive degradation over several thermal cycles at aerothermal conditions representative of high Mach number flight.

  18. Flight test operations using an F-106B research airplane modified with a wing leading-edge vortex flap

    Science.gov (United States)

    Dicarlo, Daniel J.; Brown, Philip W.; Hallissy, James B.

    1992-01-01

    Flight tests of an F-106B aircraft equipped with a leading-edge vortex flap, which represented the culmination of a research effort to examine the effectiveness of the flap, were conducted at the NASA Langley Research Center. The purpose of the flight tests was to establish a data base on the use of a wing leading-edge vortex flap as a means to validate the design and analysis methods associated with the development of such a vortical flow-control concept. The overall experiment included: refinements of the design codes for vortex flaps; numerous wind tunnel entries to aid in verifying design codes and determining basic aerodynamic characteristics; design and fabrication of the flaps, structural modifications to the wing tip and leading edges of the test aircraft; development and installation of an aircraft research instrumentation system, including wing and flap surface pressure measurements and selected structural loads measurements; ground-based simulation to assess flying qualities; and finally, flight testing. This paper reviews the operational aspects associated with the flight experiment, which includes a description of modifications to the research airplane, the overall flight test procedures, and problems encountered. Selected research results are also presented to illustrate the accomplishments of the research effort.

  19. Simulation-based MDP verification for leading-edge masks

    Science.gov (United States)

    Su, Bo; Syrel, Oleg; Pomerantsev, Michael; Hagiwara, Kazuyuki; Pearman, Ryan; Pang, Leo; Fujimara, Aki

    2017-07-01

    For IC design starts below the 20nm technology node, the assist features on photomasks shrink well below 60nm and the printed patterns of those features on masks written by VSB eBeam writers start to show a large deviation from the mask designs. Traditional geometry-based fracturing starts to show large errors for those small features. As a result, other mask data preparation (MDP) methods have become available and adopted, such as rule-based Mask Process Correction (MPC), model-based MPC and eventually model-based MDP. The new MDP methods may place shot edges slightly differently from target to compensate for mask process effects, so that the final patterns on a mask are much closer to the design (which can be viewed as the ideal mask), especially for those assist features. Such an alteration generally produces better masks that are closer to the intended mask design. Traditional XOR-based MDP verification cannot detect problems caused by eBeam effects. Much like model-based OPC verification which became a necessity for OPC a decade ago, we see the same trend in MDP today. Simulation-based MDP verification solution requires a GPU-accelerated computational geometry engine with simulation capabilities. To have a meaningful simulation-based mask check, a good mask process model is needed. The TrueModel® system is a field tested physical mask model developed by D2S. The GPU-accelerated D2S Computational Design Platform (CDP) is used to run simulation-based mask check, as well as model-based MDP. In addition to simulation-based checks such as mask EPE or dose margin, geometry-based rules are also available to detect quality issues such as slivers or CD splits. Dose margin related hotspots can also be detected by setting a correct detection threshold. In this paper, we will demonstrate GPU-acceleration for geometry processing, and give examples of mask check results and performance data. GPU-acceleration is necessary to make simulation-based mask MDP verification

  20. RANS Based Methodology for Predicting the Influence of Leading Edge Erosion on Airfoil Performance

    Energy Technology Data Exchange (ETDEWEB)

    Langel, Christopher M. [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aerospace Engineering; Chow, Raymond C. [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aerospace Engineering; van Dam, C. P. [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aerospace Engineering; Maniaci, David Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Wind Energy Technologies Dept.

    2017-10-01

    The impact of surface roughness on flows over aerodynamically designed surfaces is of interested in a number of different fields. It has long been known the surface roughness will likely accelerate the laminar- turbulent transition process by creating additional disturbances in the boundary layer. However, there are very few tools available to predict the effects surface roughness will have on boundary layer flow. There are numerous implications of the premature appearance of a turbulent boundary layer. Increases in local skin friction, boundary layer thickness, and turbulent mixing can impact global flow properties compounding the effects of surface roughness. With this motivation, an investigation into the effects of surface roughness on boundary layer transition has been conducted. The effort involved both an extensive experimental campaign, and the development of a high fidelity roughness model implemented in a R ANS solver. Vast a mounts of experimental data was generated at the Texas A&M Oran W. Nicks Low Speed Wind Tunnel for the calibration and validation of the roughness model described in this work, as well as future efforts. The present work focuses on the development of the computational model including a description of the calibration process. The primary methodology presented introduces a scalar field variable and associated transport equation that interacts with a correlation based transition model. The additional equation allows for non-local effects of surface roughness to be accounted for downstream of rough wall sections while maintaining a "local" formulation. The scalar field is determined through a boundary condition function that has been calibrated to flat plate cases with sand grain roughness. The model was initially tested on a NACA 0012 airfoil with roughness strips applied to the leading edge. Further calibration of the roughness model was performed using results from the companion experimental study on a NACA 633 -418 airfoil

  1. SiC/SiC Leading Edge Turbine Airfoil Tested Under Simulated Gas Turbine Conditions

    Science.gov (United States)

    Robinson, R. Craig; Hatton, Kenneth S.

    1999-01-01

    Silicon-based ceramics have been proposed as component materials for use in gas turbine engine hot-sections. A high pressure burner rig was used to expose both a baseline metal airfoil and ceramic matrix composite leading edge airfoil to typical gas turbine conditions to comparatively evaluate the material response at high temperatures. To eliminate many of the concerns related to an entirely ceramic, rotating airfoil, this study has focused on equipping a stationary metal airfoil with a ceramic leading edge insert to demonstrate the feasibility and benefits of such a configuration. Here, the idea was to allow the SiC/SiC composite to be integrated as the airfoil's leading edge, operating in a "free-floating" or unrestrained manner. and provide temperature relief to the metal blade underneath. The test included cycling the airfoils between simulated idle, lift, and cruise flight conditions. In addition, the airfoils were air-cooled, uniquely instrumented, and exposed to the same internal and external conditions, which included gas temperatures in excess of 1370 C (2500 F). Results show the leading edge insert remained structurally intact after 200 simulated flight cycles with only a slightly oxidized surface. The instrumentation clearly suggested a significant reduction (approximately 600 F) in internal metal temperatures as a result of the ceramic leading edge. The object of this testing was to validate the design and analysis done by Materials Research and Design of Rosemont, PA and to determine the feasibility of this design for the intended application.

  2. Application of a Beamforming Technique to the Measurement of Airfoil Leading Edge Noise

    Directory of Open Access Journals (Sweden)

    Thomas Geyer

    2012-01-01

    Full Text Available The present paper describes the use of microphone array technology and beamforming algorithms for the measurement and analysis of noise generated by the interaction of a turbulent flow with the leading edge of an airfoil. Experiments were performed using a setup in an aeroacoustic wind tunnel, where the turbulent inflow is provided by different grids. In order to exactly localize the aeroacoustic noise sources and, moreover, to separate airfoil leading edge noise from grid-generated noise, the selected deconvolution beamforming algorithm is extended to be used on a fully three-dimensional source region. The result of this extended beamforming are three-dimensional mappings of noise source locations. Besides acoustic measurements, the investigation of airfoil leading edge noise requires the measurement of parameters describing the incident turbulence, such as the intensity and a characteristic length scale or time scale. The method used for the determination of these parameters in the present study is explained in detail. To demonstrate the applicability of the extended beamforming algorithm and the experimental setup as a whole, the noise generated at the leading edge of airfoils made of porous materials was measured and compared to that generated at the leading edge of a common nonporous airfoil.

  3. Interplay between phosphoinositide lipids and calcium signals at the leading edge of chemotaxing ameboid cells☆

    Science.gov (United States)

    Falke, Joseph J.; Ziemba, Brian P.

    2014-01-01

    The chemotactic migration of eukaryotic ameboid cells up concentration gradients is among the most advanced forms of cellular behavior. Chemotaxis is controlled by a complex network of signaling proteins bound to specific lipids on the cytoplasmic surface of the plasma membrane at the front of the cell, or the leading edge. The central lipid players in this leading edge signaling pathway include the phosphoinositides PI(4,5)P2 (PIP2) and PI(3,4,5)P3 (PIP3), both of which play multiple roles. The products of PI(4,5)P2 hydrolysis, diacylglycerol (DAG) and Ins(1,4,5)P3 (IP3), are also implicated as important players. Together, these leading edge phosphoinositides and their degradation products, in concert with a local Ca2+ signal, control the recruitment and activities of many peripheral membrane proteins that are crucial to the leading edge signaling network. The present critical review summarizes the current molecular understanding of chemotactic signaling at the leading edge, including newly discovered roles of phosphoinositide lipids and Ca2+, while highlighting key questions for future research. PMID:24451847

  4. Interplay between phosphoinositide lipids and calcium signals at the leading edge of chemotaxing ameboid cells.

    Science.gov (United States)

    Falke, Joseph J; Ziemba, Brian P

    2014-09-01

    The chemotactic migration of eukaryotic ameboid cells up concentration gradients is among the most advanced forms of cellular behavior. Chemotaxis is controlled by a complex network of signaling proteins bound to specific lipids on the cytoplasmic surface of the plasma membrane at the front of the cell, or the leading edge. The central lipid players in this leading edge signaling pathway include the phosphoinositides PI(4,5)P2 (PIP2) and PI(3,4,5)P3 (PIP3), both of which play multiple roles. The products of PI(4,5)P2 hydrolysis, diacylglycerol (DAG) and Ins(1,4,5)P3 (IP3), are also implicated as important players. Together, these leading edge phosphoinositides and their degradation products, in concert with a local Ca(2+) signal, control the recruitment and activities of many peripheral membrane proteins that are crucial to the leading edge signaling network. The present critical review summarizes the current molecular understanding of chemotactic signaling at the leading edge, including newly discovered roles of phosphoinositide lipids and Ca(2+), while highlighting key questions for future research. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. α-Crystallin localizes to the leading edges of migrating lens epithelial cells

    International Nuclear Information System (INIS)

    Maddala, Rupalatha; Vasantha Rao, P.

    2005-01-01

    α-crystallin (αA and αB) is a major lens protein, which belongs to the small heat-shock family of proteins and binds to various cytoskeletal proteins including actin, vimentin and desmin. In this study, we investigated the cellular localization of αA and αB-crystallins in migrating epithelial cells isolated from porcine lens. Immunofluorescence localization and confocal imaging of αB-crystallin in confluent and in migrating subconfluent cell cultures revealed a distinct pattern of subcellular distribution. While αB-crystallin localization was predominantly cytoplasmic in confluent cultures, it was strongly localized to the leading edges of cell membrane or the lamellipodia in migrating cells. In accordance with this pattern, we found abundant levels of αB-crystallin in membrane fractions compared to cytosolic and nuclear fractions in migrating lens epithelial cells. αA-crystallin, which has 60% sequence identity to αB-crystallin, also exhibited a distribution profile localizing to the leading edge of the cell membrane in migrating lens epithelial cells. Localization of αB-crystallin to the lamellipodia appears to be dependent on phosphorylation of residue serine-59. An inhibitor of p38 MAP kinase (SB202190), but not the ERK kinase inhibitor PD98059, was found to diminish localization of αB-crystallin to the lamellipodia, and this effect was found to be associated with reduced levels of Serine-59 phosphorylated αB-crystallin in SB202190-treated migrating lens epithelial cells. αB-crystallin localization to the lamellipodia was also altered by the treatment with RGD (Arg-Ala-Asp) peptide, dominant negative N17 Rac1 GTPase, cytochalasin D and Src kinase inhibitor (PP2), but not by the Rho kinase inhibitor Y-27632 or the myosin II inhibitor, blebbistatin. Additionally, in migrating lens epithelial cells, αB-crystallin exhibited a clear co-localization with the actin meshwork, β-catenin, WAVE-1, a promoter of actin nucleation, Abi-2, a component of WAVE

  6. Suppression of dynamic stall with a leading-edge slat on a VR-7 airfoil

    Science.gov (United States)

    Mcalister, K. W.; Tung, C.

    1993-01-01

    The VR-7 airfoil was experimentally studied with and without a leading-edge slat at fixed angles of attack from 0 deg to 30 deg at Re = 200,000 and for unsteady pitching motions described by alpha equals alpha(sub m) + 10 deg(sin(wt)). The models were two dimensional, and the test was performed in a water tunnel at Ames Research Center. The unsteady conditions ranged over Re equals 100,000 to 250,000, k equals 0.001 to 0.2, and alpha(sub m) = 10 deg to 20 deg. Unsteady lift, drag, and pitching-moment measurements were obtained along with fluorescent-dye flow visualizations. The addition of the slat was found to delay the static-drag and static-moment stall by about 5 degrees and to eliminate completely the development of a dynamic-stall vortex during unsteady motions that reached angles as high as 25 degrees. In all of the unsteady cases studied, the slat caused a significant reduction in the force and moment hysteresis amplitudes. The reduced frequency was found to have the greatest effect on the results, whereas the Reynolds number had little effect on the behavior of either the basic or the slatted airfoil. The slat caused a slight drag penalty at low angles of attack, but generally increased the lift/drag ratio when averaged over the full cycle of oscillation.

  7. Streamwise counter-rotating vortices generated by triangular leading edge pattern in flat plate boundary layer

    KAUST Repository

    Hasheminejad, S. M.

    2016-01-05

    A series of flow visualizations were conducted to qualitatively study the development of streamwise counter-rotating vortices over a flat plate induced by triangular patterns at the leading edge of a flat plate. The experiments were carried out for a Reynolds number based on the pattern wavelength (λ) of 3080. The results depict the onset, development and breakdown of the vortical structures within the flat plate boundary layer. Moreover, the effect of one spanwise array of holes with diameter of 0.2λ (=3 mm) was examined. This investigation was done on two different flat plates with holes placed at the location x/λ = 2 downstream of the troughs and peaks. The presence of holes after troughs does not show any significant effect on the vortical structures. However, the plate with holes after peaks noticeably delays the vortex breakdown. In this case, the “mushroom-like” vortices move away from the wall and propagate downstream with stable vortical structures. The vortex growth is halted further downstream but start to tilt aside.

  8. CFD study on NACA 4415 airfoil implementing spherical and sinusoidal Tubercle Leading Edge.

    Directory of Open Access Journals (Sweden)

    S M A Aftab

    Full Text Available The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c, the wavelength (0.25c is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil.

  9. Distributed Roughness Effects on Blunt-Body Transition and Turbulent Heating

    Science.gov (United States)

    Hollis, Brian R.

    2014-01-01

    An experimental program has been conducted to obtain data on the effects of surface roughness on blunt bodies at laminar, transitional, and turbulent conditions. Wind tunnel models with distributed surface roughness heights from 0.06 mm to 1.75 mm were tested and heating data were obtained using global surface thermography. Heating rates of up to 85% higher than predicted, smooth-surface turbulent levels were measured.

  10. Test and Analysis Correlation of Form Impact onto Space Shuttle Wing Leading Edge RCC Panel 8

    Science.gov (United States)

    Fasanella, Edwin L.; Lyle, Karen H.; Gabrys, Jonathan; Melis, Matthew; Carney, Kelly

    2004-01-01

    Soon after the Columbia Accident Investigation Board (CAIB) began their study of the space shuttle Columbia accident, "physics-based" analyses using LS-DYNA were applied to characterize the expected damage to the Reinforced Carbon-Carbon (RCC) leading edge from high-speed foam impacts. Forensic evidence quickly led CAIB investigators to concentrate on the left wing leading edge RCC panels. This paper will concentrate on the test of the left-wing RCC panel 8 conducted at Southwest Research Institute (SwRI) and the correlation with an LS-DYNA analysis. The successful correlation of the LS-DYNA model has resulted in the use of LS-DYNA as a predictive tool for characterizing the threshold of damage for impacts of various debris such as foam, ice, and ablators onto the RCC leading edge for shuttle return-to-flight.

  11. Fundamental aerodynamic characteristics of delta wings with leading-edge vortex flows

    Science.gov (United States)

    Wood, R. M.; Miller, D. S.

    1985-01-01

    An investigation of the aerodynamics of sharp leading-edge delta wings at supersonic speeds has been conducted. The supporting experimental data for this investigation were taken from published force, pressure, and flow-visualization data in which the Mach number normal to the wing leading edge is always less than 1.0. The individual upper- and lower-surface nonlinear characteristics for uncambered delta wings are determined and presented in three charts. The upper-surface data show that both the normal-force coefficient and minimum pressure coefficient increase nonlinearly with a decreasing slope with increasing angle of attack. The lower-surface normal-force coefficient was shown to be independent of Mach number and to increase nonlinearly, with an increasing slope, with increasing angle of attack. These charts are then used to define a wing-design space for sharp leading-edge delta wings.

  12. Membrane tension controls adhesion positioning at the leading edge of cells.

    Science.gov (United States)

    Pontes, Bruno; Monzo, Pascale; Gole, Laurent; Le Roux, Anabel-Lise; Kosmalska, Anita Joanna; Tam, Zhi Yang; Luo, Weiwei; Kan, Sophie; Viasnoff, Virgile; Roca-Cusachs, Pere; Tucker-Kellogg, Lisa; Gauthier, Nils C

    2017-09-04

    Cell migration is dependent on adhesion dynamics and actin cytoskeleton remodeling at the leading edge. These events may be physically constrained by the plasma membrane. Here, we show that the mechanical signal produced by an increase in plasma membrane tension triggers the positioning of new rows of adhesions at the leading edge. During protrusion, as membrane tension increases, velocity slows, and the lamellipodium buckles upward in a myosin II-independent manner. The buckling occurs between the front of the lamellipodium, where nascent adhesions are positioned in rows, and the base of the lamellipodium, where a vinculin-dependent clutch couples actin to previously positioned adhesions. As membrane tension decreases, protrusion resumes and buckling disappears, until the next cycle. We propose that the mechanical signal of membrane tension exerts upstream control in mechanotransduction by periodically compressing and relaxing the lamellipodium, leading to the positioning of adhesions at the leading edge of cells. © 2017 Pontes et al.

  13. Modification of the NACA 632-415 leading edge for better aerodynamic performance

    DEFF Research Database (Denmark)

    Bak, C.; Fuglsang, P.

    2002-01-01

    Double stall causes more than one power level when stall-regulated wind turbines operate in stall. This involves significant uncertainty on power production and loads. To avoid double stall, a new leading edge was designed for the NACA 632-415 airfoil, an airfoil that is often used in the tip...... region of wind turbines. A numerical optimization tool incorporating XFOIL was used with a special formulation for the airfoil leading edge shape. The EllipSys2D CFD code was used to analyze the modified airfoil. In theory and in wind tunnel tests, the modified airfoil showed smooth and stable stall...... stall and aerodynamic damping characteristics for the modified airfoil and the NACA 632-415 airfoil were the same. The modified airfoil with leading edge roughness in general had better characteristics compared with the NACA 632-415 airfoil. ©2002 ASME...

  14. A mechanism of leading-edge protrusion in the absence of Arp2/3 complex.

    Science.gov (United States)

    Suraneni, Praveen; Fogelson, Ben; Rubinstein, Boris; Noguera, Philippe; Volkmann, Niels; Hanein, Dorit; Mogilner, Alex; Li, Rong

    2015-03-01

    Cells employ protrusive leading edges to navigate and promote their migration in diverse physiological environments. Classical models of leading-edge protrusion rely on a treadmilling dendritic actin network that undergoes continuous assembly nucleated by the Arp2/3 complex, forming ruffling lamellipodia. Recent work demonstrated, however, that, in the absence of the Arp2/3 complex, fibroblast cells adopt a leading edge with filopodia-like protrusions (FLPs) and maintain an ability to move, albeit with altered responses to different environmental signals. We show that formin-family actin nucleators are required for the extension of FLPs but are insufficient to produce a continuous leading edge in fibroblasts lacking Arp2/3 complex. Myosin II is concentrated in arc-like regions of the leading edge in between FLPs, and its activity is required for coordinated advancement of these regions with formin-generated FLPs. We propose that actomyosin contraction acting against membrane tension advances the web of arcs between FLPs. Predictions of this model are verified experimentally. The dependence of myosin II in leading-edge advancement helps explain the previously reported defect in directional movement in the Arpc3-null fibroblasts. We provide further evidence that this defect is cell autonomous during chemotaxis. © 2015 Suraneni et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  15. Drag Coefficient of Water Droplets Approaching the Leading Edge of an Airfoil

    Science.gov (United States)

    Vargas, Mario; Sor, Suthyvann; Magarino, Adelaida Garcia

    2013-01-01

    This work presents results of an experimental study on droplet deformation and breakup near the leading edge of an airfoil. The experiment was conducted in the rotating rig test cell at the Instituto Nacional de Tecnica Aeroespacial (INTA) in Madrid, Spain. An airfoil model was placed at the end of the rotating arm and a monosize droplet generator produced droplets that fell from above, perpendicular to the path of the airfoil. The interaction between the droplets and the airfoil was captured with high speed imaging and allowed observation of droplet deformation and breakup as the droplet approached the airfoil near the stagnation line. Image processing software was used to measure the position of the droplet centroid, equivalent diameter, perimeter, area, and the major and minor axes of an ellipse superimposed over the deforming droplet. The horizontal and vertical displacement of each droplet against time was also measured, and the velocity, acceleration, Weber number, Bond number, Reynolds number, and the drag coefficients were calculated along the path of the droplet to the beginning of breakup. Results are presented and discussed for drag coefficients of droplets with diameters in the range of 300 to 1800 micrometers, and airfoil velocities of 50, 70 and 90 meters/second. The effect of droplet oscillation on the drag coefficient is discussed.

  16. Numerical Predictions of Sonic Boom Signatures for a Straight Line Segmented Leading Edge Model

    Science.gov (United States)

    Elmiligui, Alaa A.; Wilcox, Floyd J.; Cliff, Susan; Thomas, Scott

    2012-01-01

    A sonic boom wind tunnel test was conducted on a straight-line segmented leading edge (SLSLE) model in the NASA Langley 4- by 4- Foot Unitary Plan Wind Tunnel (UPWT). The purpose of the test was to determine whether accurate sonic boom measurements could be obtained while continuously moving the SLSLE model past a conical pressure probe. Sonic boom signatures were also obtained using the conventional move-pause data acquisition method for comparison. The continuous data acquisition approach allows for accurate signatures approximately 15 times faster than a move-pause technique. These successful results provide an incentive for future testing with greatly increased efficiency using the continuous model translation technique with the single probe to measure sonic boom signatures. Two widely used NASA codes, USM3D (Navier-Stokes) and CART3D-AERO (Euler, adjoint-based adaptive mesh), were used to compute off-body sonic boom pressure signatures of the SLSLE model at several different altitudes below the model at Mach 2.0. The computed pressure signatures compared well with wind tunnel data. The effect of the different altitude for signature extraction was evaluated by extrapolating the near field signatures to the ground and comparing pressure signatures and sonic boom loudness levels.

  17. Generation of Fullspan Leading-Edge 3D Ice Shapes for Swept-Wing Aerodynamic Testing

    Science.gov (United States)

    Camello, Stephanie C.; Lee, Sam; Lum, Christopher; Bragg, Michael B.

    2016-01-01

    The deleterious effect of ice accretion on aircraft is often assessed through dry-air flight and wind tunnel testing with artificial ice shapes. This paper describes a method to create fullspan swept-wing artificial ice shapes from partial span ice segments acquired in the NASA Glenn Icing Reserch Tunnel for aerodynamic wind-tunnel testing. Full-scale ice accretion segments were laser scanned from the Inboard, Midspan, and Outboard wing station models of the 65% scale Common Research Model (CRM65) aircraft configuration. These were interpolated and extrapolated using a weighted averaging method to generate fullspan ice shapes from the root to the tip of the CRM65 wing. The results showed that this interpolation method was able to preserve many of the highly three dimensional features typically found on swept-wing ice accretions. The interpolated fullspan ice shapes were then scaled to fit the leading edge of a 8.9% scale version of the CRM65 wing for aerodynamic wind-tunnel testing. Reduced fidelity versions of the fullspan ice shapes were also created where most of the local three-dimensional features were removed. The fullspan artificial ice shapes and the reduced fidelity versions were manufactured using stereolithography.

  18. Turbulence Amplification with Incidence at the Leading Edge of a Compressor Cascade

    Directory of Open Access Journals (Sweden)

    Garth V. Hobson

    1999-01-01

    Full Text Available Detailed measurements, with a two-component laser-Doppler velocimeter and a thermal anemometer were made near the suction surface leading edge of controlled-diffusion airfoils in cascade. The Reynolds number was near 700,000, Mach number equal to 0.25, and freestream turbulence was at 1.5% ahead of the cascade.

  19. The Leading Edge of Early Childhood Education: Linking Science to Policy for a New Generation

    Science.gov (United States)

    Lesaux, Nonie K., Ed.; Jones, Stephanie M., Ed.

    2016-01-01

    "The Leading Edge of Early Childhood Education" aims to support the effort to simultaneously scale up and improve the quality of early childhood education by bringing together relevant insights from emerging research to provide guidance for this critical, fledgling field. It reflects the growing recognition that early childhood…

  20. Leading-Edge Noise Prediction of General Airfoil Profiles with Spanwise-Varying Inflow Conditions

    NARCIS (Netherlands)

    Miotto, Renato Fuzaro; Wolf, William Roberto; De Santana, Leandro Dantas

    2018-01-01

    This paper presents a study of the leading-edge noise radiated by an airfoil undergoing a turbulent inflow. The noise prediction of generic airfoil profiles subjected to spanwise-varying inflow conditions is performed with the support of Amiet’s theory and the inverse strip technique. In the

  1. New approach to the suction force at the leading edge of a profile with zero thickness

    NARCIS (Netherlands)

    Sparenberg, JA; de Jager, EM

    2004-01-01

    This paper considers the suction force at the leading edge of a profile with zero thickness in an incompressible and inviscid fluid flow. The theory is linear, and the approach to the suction force is from the innerside of the profile. It is shown that the suction force can be considered as an

  2. Leading edge erosion of coated wind turbine blades: Review of coating life models

    NARCIS (Netherlands)

    Slot, H.M.; Gelinck, E.R.M.; Rentrop, A.; van der Heide, Emile

    2015-01-01

    Erosion of the leading edge of wind turbine blades by droplet impingement wear, reduces blade aerodynamic efficiency and power output. Eventually, it compromises the integrity of blade surfaces. Elastomeric coatings are currently used for erosion resistance, yet the life of such coatings cannot be

  3. Leading-Edge Noise Prediction of General Airfoil Profiles with Spanwise-Varying Inflow Conditions

    NARCIS (Netherlands)

    Miotto, Renato Fuzaro; Wolf, William Roberto; De Santana, Leandro Dantas

    This paper presents a study of the leading-edge noise radiated by an airfoil undergoing a turbulent inflow. The noise prediction of generic airfoil profiles subjected to spanwise-varying inflow conditions is performed with the support of Amiet’s theory and the inverse strip technique. In the

  4. Defibrotide blunts the prothrombotic effect of thalidomide on endothelial cells.

    Science.gov (United States)

    Echart, C L; Somaini, S; Distaso, M; Palumbo, A; Richardson, P G; Fareed, J; Iacobelli, M

    2012-01-01

    Patients with multiple myeloma (MM) are at relatively high risk of developing thromboembolic events such deep venous thrombosis (DVT) where thalidomide therapy has been identified to increase this risk. Defibrotide (DF), a polydisperse oligonucleotide, showed previously to counteract the alterations in endothelial cells (ECs) induced by lipopolysaccharide. It prompts us to investigate the impact of thalidomide on ECs and whether DF modulates changes in fibrinolysis induced by thalidomide. In this in vitro study, MM by itself alters the profibrinolytic potential of ECs decreasing the tissue plasminogen activator (t-PA) and increasing the plasminogen activator inhibitor 1 (PAI-1) levels which is potentiated by thalidomide. Defibrotide was able to counteract these effects. Additionally, DF upregulated the t-PA and downregulated PAI-1 gene expression modulated by thalidomide. Defibrotide also protects ECs from thalidomide-mediated cell death without interfering with its antitumor effects. These findings support DF clinical use for the prevention of DVT induced by immunomodulatory drugs.

  5. Thermostructural applications of heat pipes for cooling leading edges of high-speed aerospace vehicles

    Science.gov (United States)

    Camarda, Charles J.; Glass, David E.

    1992-01-01

    Heat pipes have been considered for use on wing leading edge for over 20 years. Early concepts envisioned metal heat pipes cooling a metallic leading edge. Several superalloy/sodium heat pipes were fabricated and successfully tested for wing leading edge cooling. Results of radiant heat and aerothermal testing indicate the feasibility of using heat pipes to cool the stagnation region of shuttle-type space transportation systems. The test model withstood a total seven radiant heating tests, eight aerothermal tests, and twenty-seven supplemental radiant heating tests. Cold-wall heating rates ranged from 21 to 57 Btu/sq ft-s and maximum operating temperatures ranged from 1090 to 1520 F. Follow-on studies investigated the application of heat pipes to cool the stagnation regions of single-stage-to-orbit and advanced shuttle vehicles. Results of those studies indicate that a 'D-shaped' structural design can reduce the mass of the heat-pipe concept by over 44 percent compared to a circular heat-pipe geometry. Simple analytical models for heat-pipe startup from the frozen state (working fluid initially frozen) were adequate to approximate transient, startup, and steady-state heat-pipe performance. Improvement in analysis methods has resulted in the development of a finite-element analysis technique to predict heat-pipe startup from the frozen state. However, current requirements of light-weight design and reliability suggest that metallic heat pipes embedded in a refractory composite material should be used. This concept is the concept presently being evaluated for NASP. A refractory-composite/heat-pipe-cooled wing leading edge is currently being considered for the National Aero-Space Plane (NASP). This concept uses high-temperature refractory-metal/lithium heat pipes embedded within a refractory-composite structure and is significantly lighter than an actively cooled wing leading edge because it eliminates the need for active cooling during ascent and descent. Since the

  6. High fat diet blunts the effects of leptin on ventilation and on carotid body activity.

    Science.gov (United States)

    Ribeiro, Maria J; Sacramento, Joana F; Gallego-Martin, Teresa; Olea, Elena; Melo, Bernardete F; Guarino, Maria P; Yubero, Sara; Obeso, Ana; Conde, Silvia V

    2017-12-22

    Leptin plays a role in the control of breathing, acting mainly on central nervous system; however, leptin receptors have been recently shown to be expressed in the carotid body (CB), and this finding suggests a physiological role for leptin in the regulation of CB function. Leptin increases minute ventilation in both basal and hypoxic conditions in rats. It increases the frequency of carotid sinus nerve discharge in basal conditions, as well as the release of adenosine from the CB. However, in a metabolic syndrome animal model, the effects of leptin in ventilatory control, carotid sinus nerve activity and adenosine release by the CB are blunted. Although leptin may be involved in triggering CB overactivation in initial stages of obesity and dysmetabolism, resistance to leptin signalling and blunting of responses develops in metabolic syndrome animal models. Leptin plays a role in the control of breathing, acting mainly on central nervous system structures. Leptin receptors are expressed in the carotid body (CB) and this finding has been associated with a putative physiological role of leptin in the regulation of CB function. Since, the CBs are implicated in energy metabolism, here we tested the effects of different concentrations of leptin administration on ventilatory parameters and on carotid sinus nerve (CSN) activity in control and high-fat (HF) diet fed rats, in order to clarify the role of leptin in ventilation control in metabolic disease states. We also investigated the expression of leptin receptors and the neurotransmitters involved in leptin signalling in the CBs. We found that in non-disease conditions, leptin increases minute ventilation in both basal and hypoxic conditions. However, in the HF model, the effect of leptin in ventilatory control is blunted. We also observed that HF rats display an increased frequency of CSN discharge in basal conditions that is not altered by leptin, in contrast to what is observed in control animals. Leptin did not

  7. Aerodynamic improvement of a delta wing in combination with leading edge flaps

    Directory of Open Access Journals (Sweden)

    Tadateru Ishide

    2017-11-01

    Full Text Available Recently, various studies of micro air vehicle (MAV and unmanned air vehicle (UAV have been reported from wide range points of view. The aim of this study is to research the aerodynamic improvement of delta wing in low Reynold’s number region to develop an applicative these air vehicle. As an attractive tool in delta wing, leading edge flap (LEF is employed to directly modify the strength and structure of vortices originating from the separation point along the leading edge. Various configurations of LEF such as drooping apex flap and upward deflected flap are used in combination to enhance the aerodynamic characteristics in the delta wing. The fluid force measurement by six component load cell and particle image velocimetry (PIV analysis are performed as the experimental method. The relations between the aerodynamic superiority and the vortex behavior around the models are demonstrated.

  8. Structural characteristics of the shock-induced boundary layer separation extended to the leading edge

    Science.gov (United States)

    Tao, Y.; Liu, W. D.; Fan, X. Q.; Zhao, Y. L.

    2017-07-01

    For a better understanding of the local unstart of supersonic/hypersonic inlet, a series of experiments has been conducted to investigate the shock-induced boundary layer separation extended to the leading edge. Using the nanoparticle-based planar laser scattering, we recorded the fine structures of these interactions under different conditions and paid more attention to their structural characteristics. According to their features, these interactions could be divided into four types. Specifically, Type A wave pattern is similar to the classic shock wave/turbulent boundary layer interaction, and Type B wave configuration consists of an overall Mach reflection above the large scale separation bubble. Due to the gradual decrease in the size of the separation bubble, the separation bubble was replaced by several vortices (Type C wave pattern). Besides, for Type D wave configuration which exists in the local unstart inlet, there appears to be some flow spillage around the leading edge.

  9. Chronophin coordinates cell leading edge dynamics by controlling active cofilin levels

    Science.gov (United States)

    Delorme-Walker, Violaine; Seo, Ji-Yeon; Gohla, Antje; Fowler, Bruce; Bohl, Ben; DerMardirossian, Céline

    2015-01-01

    Cofilin, a critical player of actin dynamics, is spatially and temporally regulated to control the direction and force of membrane extension required for cell locomotion. In carcinoma cells, although the signaling pathways regulating cofilin activity to control cell direction have been established, the molecular machinery required to generate the force of the protrusion remains unclear. We show that the cofilin phosphatase chronophin (CIN) spatiotemporally regulates cofilin activity at the cell edge to generate persistent membrane extension. We show that CIN translocates to the leading edge in a PI3-kinase–, Rac1-, and cofilin-dependent manner after EGF stimulation to activate cofilin, promotes actin free barbed end formation, accelerates actin turnover, and enhances membrane protrusion. In addition, we establish that CIN is crucial for the balance of protrusion/retraction events during cell migration. Thus, CIN coordinates the leading edge dynamics by controlling active cofilin levels to promote MTLn3 cell protrusion. PMID:26324884

  10. Methodology for heat flux investigation on leading edges using infrared thermography

    Czech Academy of Sciences Publication Activity Database

    Corre, Y.; Gardarein, J.-L.; Dejarnac, Renaud; Gaspar, J.; Gunn, J. P.; Aumeunier, M.-H.; Courtois, X.; Missirlian, M.; Rigollet, F.

    2017-01-01

    Roč. 57, č. 1 (2017), č. článku 016009. ISSN 0029-5515 Institutional support: RVO:61389021 Keywords : IR thermography * leading edge * heat flux * limiter Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.307, year: 2016 http://iopscience.iop.org/article/10.1088/0029-5515/57/1/016009/meta

  11. Fracture Mechanics Analyses of the Slip-Side Joggle Regions of Wing-Leading-Edge Panels

    Science.gov (United States)

    Raju, Ivatury S.; Knight, Norman F., Jr.; Song, Kyongchan; Phillips, Dawn R.

    2011-01-01

    The Space Shuttle wing-leading edge consists of panels that are made of reinforced carbon-carbon. Coating spallation was observed near the slip-side region of the panels that experience extreme heating. To understand this phenomenon, a root-cause investigation was conducted. As part of that investigation, fracture mechanics analyses of the slip-side joggle regions of the hot panels were conducted. This paper presents an overview of the fracture mechanics analyses.

  12. ARF1 recruits RAC1 to leading edge in neutrophil chemotaxis.

    Science.gov (United States)

    Mazaki, Yuichi; Onodera, Yasuhito; Higashi, Tsunehito; Horinouchi, Takahiro; Oikawa, Tsukasa; Sabe, Hisataka

    2017-10-02

    The small GTPase ARF1 mediates membrane trafficking mostly from the Golgi, and is essential for the G protein-coupled receptor (GPCR)-mediated chemotaxis of neutrophils. In this process, ARF1 is activated by the guanine nucleotide exchanger GBF1, and is inactivated by the GTPase-activating protein GIT2. Neutrophils generate the Gβγ-PAK1-αPIX-GIT2 linear complex during GPCR-induced chemotaxis, in which αPIX activates RAC1/CDC42, which then employs PAK1. However, it has remained unclear as to why GIT2 is included in this complex. We investigated the association between ARF1 and RAC1/CDC42 during the fMLP-stimulated chemotaxis of HL60 cells. We found that the silencing of GBF1 significantly impaired the recruitment of RAC1 to the leading edges, but not PAK1, αPIX, RAC2, or CDC42. A significant population of RAC1 colocalized with ARF1 at the leading edges in stimulated cells, whereas fMLP activated both ARF1 and ARF5. Consistently, the silencing of ARF1, but not ARF5, impaired the recruitment of RAC1, whereas the silencing of RAC1 did not affect the recruitment of ARF1 to the leading edges. Our results indicated that the activation of ARF1 triggers the plasma membrane recruitment of RAC1 in GPCR-mediated chemotaxis, which is essential for cortical actin remodeling. Thus, membrane remodeling at the leading edges appears to precede actin remodeling in chemotaxis. Together with the fact that GIT2, which inactivates ARF1, is an integral component of the machinery activating RAC1, we proposed a model in which the ARF1-RAC1 linkage enables the regulation of ARF1 by repetitive on/off cycles during GPCR-mediated neutrophil chemotaxis.

  13. Reduced innate immunity of Cuban Treefrogs at leading edge of range expansion.

    Science.gov (United States)

    Goetz, Scott M; Romagosa, Christina M; Appel, Arthur G; Guyer, Craig; Mendonça, Mary T

    2017-12-01

    During geographic range expansion, populations of non-indigenous species at the invasion front may benefit from directing resources away from immune defense. To test this hypothesis, we investigated the strength of two innate immune components in populations of invasive Cuban Treefrogs (Osteopilus septentrionalis) in a long-colonized area (core region) and at the invasion front (leading-edge region). First, we compared the region-specific metabolic response of frogs injected with an endotoxin that induces systemic inflammation (lipopolysaccharide, LPS) to sham-injected control frogs pooled from both regions. Males and females were analyzed independently because we detected a sex-related difference in mass-independent metabolism of control frogs, with males exhibiting a significantly higher metabolic rate (F 1, 21  = 29.02, P leading-edge populations, there was no significant difference in the metabolic rate of LPS-injected and control frogs (males, P  = 0.195; females, P  = 0.132). Second, we directly compared bacterial killing ability of frog blood plasma between regions. Bactericidal ability of plasma was significantly greater in frogs from the core region in comparison with those at the leading edge (F 1, 26   = 28.67, P < 0.001). For both immune components that we examined, populations from the core exhibited stronger immune responses. Our findings support hypotheses predicting an inverse relationship between immunity and range expansion. © 2018 Wiley Periodicals, Inc.

  14. Rapid and dynamic arginylation of the leading edge β-actin is required for cell migration.

    Science.gov (United States)

    Pavlyk, Iuliia; Leu, Nicolae A; Vedula, Pavan; Kurosaka, Satoshi; Kashina, Anna

    2018-04-01

    β-actin plays key roles in cell migration. Our previous work demonstrated that β-actin in migratory non-muscle cells is N-terminally arginylated and that this arginylation is required for normal lamellipodia extension. Here, we examined the function of β-actin arginylation in cell migration. We found that arginylated β-actin is concentrated at the leading edge of lamellipodia and that this enrichment is abolished after serum starvation as well as in contact-inhibited cells in confluent cultures, suggesting that arginylated β-actin at the cell leading edge is coupled to active migration. Arginylated actin levels exhibit dynamic changes in response to cell stimuli, lowered after serum starvation and dramatically elevating within minutes after cell stimulation by readdition of serum or lysophosphatidic acid. These dynamic changes require active translation and are not seen in confluent contact-inhibited cell cultures. Microinjection of arginylated actin antibodies into cells severely and specifically inhibits their migration rates. Together, these data strongly suggest that arginylation of β-actin is a tightly regulated dynamic process that occurs at the leading edge of locomoting cells in response to stimuli and is integral to the signaling network that regulates cell migration. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Mechanism of Supercooled Water Droplet Breakup near the Leading Edge of an Airfoil

    Science.gov (United States)

    Veras-Alba, Belen; Palacios, Jose; Vargas, Mario; Ruggeri, Charles; Bartkus, Tadas P.

    2017-01-01

    This work presents the results of an experimental study on supercooled droplet deformation and breakup near the leading edge of an airfoil. The results are compared to prior room temperature droplet deformation results to explore the effects of droplet supercooling. The experiments were conducted in the Adverse Environment Rotor Test Stand (AERTS) at The Pennsylvania State University. An airfoil model placed at the end of the rotor blades mounted onto the hub in the AERTS chamber was moved at speeds ranging between 50 and 80 m/sec. The temperature of the chamber was set at -20°C. A monotonic droplet generator was used to produce droplets that fell from above, perpendicular to the path of the airfoil. The supercooled state of the droplets was determined by measurement of the temperature of the drops at various locations below the droplet generator exit. A temperature prediction code was also used to estimate the temperature of the droplets based on vertical velocity and the distance traveled by droplets from the droplet generator to the airfoil stagnation line. High speed imaging was employed to observe the interaction between the droplets and the airfoil. The high speed imaging provided droplet deformation information as the droplet approached the airfoil near the stagnation line. A tracking software program was used to measure the horizontal and vertical displacement of the droplet against time. It was demonstrated that to compare the effects of water supercooling on droplet deformation, the ratio of the slip velocity and the initial droplet velocity must be equal. A case with equal slip velocity to initial velocity ratios was selected for room temperature and supercooled droplet conditions. The airfoil velocity was 60 m/s and the slip velocity for both sets of data was 40 m/s. In these cases, the deformation of the weakly supercooled and warm droplets did not present different trends. The similar behavior for both environmental conditions indicates that water

  16. Simulated big sagebrush regeneration supports predicted changes at the trailing and leading edges of distribution shifts

    Science.gov (United States)

    Schlaepfer, Daniel R.; Taylor, Kyle A.; Pennington, Victoria E.; Nelson, Kellen N.; Martin, Trace E.; Rottler, Caitlin M.; Lauenroth, William K.; Bradford, John B.

    2015-01-01

    Many semi-arid plant communities in western North America are dominated by big sagebrush. These ecosystems are being reduced in extent and quality due to economic development, invasive species, and climate change. These pervasive modifications have generated concern about the long-term viability of sagebrush habitat and sagebrush-obligate wildlife species (notably greater sage-grouse), highlighting the need for better understanding of the future big sagebrush distribution, particularly at the species' range margins. These leading and trailing edges of potential climate-driven sagebrush distribution shifts are likely to be areas most sensitive to climate change. We used a process-based regeneration model for big sagebrush, which simulates potential germination and seedling survival in response to climatic and edaphic conditions and tested expectations about current and future regeneration responses at trailing and leading edges that were previously identified using traditional species distribution models. Our results confirmed expectations of increased probability of regeneration at the leading edge and decreased probability of regeneration at the trailing edge below current levels. Our simulations indicated that soil water dynamics at the leading edge became more similar to the typical seasonal ecohydrological conditions observed within the current range of big sagebrush ecosystems. At the trailing edge, an increased winter and spring dryness represented a departure from conditions typically supportive of big sagebrush. Our results highlighted that minimum and maximum daily temperatures as well as soil water recharge and summer dry periods are important constraints for big sagebrush regeneration. Overall, our results confirmed previous predictions, i.e., we see consistent changes in areas identified as trailing and leading edges; however, we also identified potential local refugia within the trailing edge, mostly at sites at higher elevation. Decreasing

  17. Case Studies of Leading Edge Small Urban High Schools. Relevance Strategic Designs: 5. Life Academy of Health and Bioscience

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  18. Case Studies of Leading Edge Small Urban High Schools. Relevance Strategic Designs: 8. High Tech High School

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  19. Case Studies of Leading Edge Small Urban High Schools. Personalization Strategic Designs: 9. MetWest High School

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  20. Case Studies of Leading Edge Small Urban High Schools. Relevance Strategic Designs: 7. TechBoston Academy

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  1. Case Studies of Leading Edge Small Urban High Schools. Core Academic Strategic Designs: 3. University Park Campus School

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  2. Case Studies of Leading Edge Small Urban High Schools. Core Academic Strategic Designs: 1. Academy of the Pacific Rim

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  3. Case Studies of Leading Edge Small Urban High Schools. Core Academic Strategic Designs: 2. Noble Street Charter High School

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  4. Resveratrol blunts the positive effects of exercise training on cardiovascular health in aged men

    DEFF Research Database (Denmark)

    Hybholt, Lasse Gliemann; Schmidt, Jakob Friis; Olesen, Jesper

    2013-01-01

    on atherosclerosis marker VCAM-1. Sirtuin 1 protein levels were not affected by resveratrol supplementation. These findings indicate that, whereas exercise training effectively improves several cardiovascular health parameters in aged men, concomitant resveratrol supplementation blunts most of these effects.......Aging is thought to be associated with decreased vascular function partly due to oxidative stress. Resveratrol is a polyphenol, which, in animal studies has been shown to decrease atherosclerosis, improve cardiovascular health and physical capacity, in part through its effects on Sirtuin 1.......02) and muscle TBX synthase was higher in the resveratrol group after training (P effects of exercise on LDL, TC/HDL ratio and triglycerides concentrations in blood (P effect of exercise training...

  5. Event review: How Interesting Archaeology Is! - Captivating and Leading-Edge Student Research

    Directory of Open Access Journals (Sweden)

    Atsushi Uemine

    2015-03-01

    Full Text Available Kyoto City Archaeological Museum situated in Kansai region, the central part of Honshu Island, Japan, has held special exhibitions in collaboration with external organizations every year since 2011. From 2011 to 2013, several universities and even a high school have participated projects, and in 2014, the Kansai Archaeological Association for Students (KAAS played an important role as partner, producing the exhibit “ここまでわかる!考古学―学生が魅せる最先端” (“How Interesting Archaeology Is! - Captivating and Leading-Edge Student Research”.

  6. A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators.

    Science.gov (United States)

    Du, Junwei; Schmall, Jeffrey P; Judenhofer, Martin S; Di, Kun; Yang, Yongfeng; Cherry, Simon R

    2017-09-01

    The leading edge timing pick-off technique is the simplest timing extraction method for PET detectors. Due to the inherent time-walk of the leading edge technique, corrections should be made to improve timing resolution, especially for time-of-flight PET. Time-walk correction can be done by utilizing the relationship between the threshold crossing time and the event energy on an event by event basis. In this paper, a time-walk correction method is proposed and evaluated using timing information from two identical detectors both using leading edge discriminators. This differs from other techniques that use an external dedicated reference detector, such as a fast PMT-based detector using constant fraction techniques to pick-off timing information. In our proposed method, one detector was used as reference detector to correct the time-walk of the other detector. Time-walk in the reference detector was minimized by using events within a small energy window (508.5 - 513.5 keV). To validate this method, a coincidence detector pair was assembled using two SensL MicroFB SiPMs and two 2.5 mm × 2.5 mm × 20 mm polished LYSO crystals. Coincidence timing resolutions using different time pick-off techniques were obtained at a bias voltage of 27.5 V and a fixed temperature of 20 °C. The coincidence timing resolution without time-walk correction were 389.0 ± 12.0 ps (425 -650 keV energy window) and 670.2 ± 16.2 ps (250-750 keV energy window). The timing resolution with time-walk correction improved to 367.3 ± 0.5 ps (425 - 650 keV) and 413.7 ± 0.9 ps (250 - 750 keV). For comparison, timing resolutions were 442.8 ± 12.8 ps (425 - 650 keV) and 476.0 ± 13.0 ps (250 - 750 keV) using constant fraction techniques, and 367.3 ± 0.4 ps (425 - 650 keV) and 413.4 ± 0.9 ps (250 - 750 keV) using a reference detector based on the constant fraction technique. These results show that the proposed leading edge based time-walk correction method works well. Timing resolution obtained

  7. Effect of local energy supply to a hypersonic flow on the drag of bodies with different nose bluntness

    International Nuclear Information System (INIS)

    Borzov, V.Yu.; Rybka, I.V.; Yur'ev, A.S.

    1995-01-01

    Parameters of the axisymmetric flow around bodies with different bluntness are compared in the case of constant energy supply to the main hypersonic flow. Flow structures, drag coefficients, and expenditure of energy on overcoming drag are analyzed with the effect of thermal energy on the flow taken into account for different bodies with equal volume

  8. The effect of crack blunting on the competition between dislocation nucleation and cleavage

    Science.gov (United States)

    Fischer, Lisa L.; Beltz, Glenn E.

    2001-03-01

    To better understand the ductile versus brittle fracture behavior of crystalline materials, attention should be directed towards physically realistic crack geometries. Currently, continuum models of ductile versus brittle behavior are typically based on the analysis of a pre-existing sharp crack in order to use analytical solutions for the stress fields around the crack tip. This paper examines the effects of crack blunting on the competition between dislocation nucleation and atomic decohesion using continuum methods. We accomplish this by assuming that the crack geometry is elliptical, which has the primary advantage that the stress fields are available in closed form. These stress field solutions are then used to calculate the thresholds for dislocation nucleation and atomic decohesion. A Peierls-type framework is used to obtain the thresholds for dislocation nucleation, in which the region of the slip plane ahead of the crack develops a distribution of slip discontinuity prior to nucleation. This slip distribution increases as the applied load is increased until an instability is reached and the governing integral equation can no longer be solved. These calculations are carried out for various crack tip geometries to ascertain the effects of crack tip blunting. The thresholds for atomic decohesion are calculated using a cohesive zone model, in which the region of the crack front develops a distribution of opening displacement prior to atomic decohesion. Again, loading of the elliptical crack tip eventually results in an instability, which marks the onset of crack advance. These calculations are carried out for various crack tip geometries. The results of these separate calculations are presented as the critical energy release rates versus the crack tip radius of curvature for a given crack length. The two threshold curves are compared simultaneously to determine which failure mode is energetically more likely at various crack tip curvatures. From these

  9. Direct Numerical Simulation of an Airfoil with Sand Grain Roughness on the Leading Edge

    Science.gov (United States)

    Ribeiro, Andre F. P.; Casalino, Damiano; Fares, Ehab; Choudhari, Meelan

    2016-01-01

    As part of a computational study of acoustic radiation due to the passage of turbulent boundary layer eddies over the trailing edge of an airfoil, the Lattice-Boltzmann method is used to perform direct numerical simulations of compressible, low Mach number flow past an NACA 0012 airfoil at zero degrees angle of attack. The chord Reynolds number of approximately 0.657 million models one of the test conditions from a previous experiment by Brooks, Pope, and Marcolini at NASA Langley Research Center. A unique feature of these simulations involves direct modeling of the sand grain roughness on the leading edge, which was used in the abovementioned experiment to trip the boundary layer to fully turbulent flow. This report documents the findings of preliminary, proof-of-concept simulations based on a narrow spanwise domain and a limited time interval. The inclusion of fully-resolved leading edge roughness in this simulation leads to significantly earlier transition than that in the absence of any roughness. The simulation data is used in conjunction with both the Ffowcs Williams-Hawkings acoustic analogy and a semi-analytical model by Roger and Moreau to predict the farfield noise. The encouraging agreement between the computed noise spectrum and that measured in the experiment indicates the potential payoff from a full-fledged numerical investigation based on the current approach. Analysis of the computed data is used to identify the required improvements to the preliminary simulations described herein.

  10. Conjugate calculation of a film-cooled blade for improvement of the leading edge cooling configuration

    Directory of Open Access Journals (Sweden)

    Norbert Moritz

    2013-03-01

    Full Text Available Great efforts are still put into the design process of advanced film-cooling configurations. In particular, the vanes and blades of turbine front stages have to be cooled extensively for a safe operation. The conjugate calculation technique is used for the three-dimensional thermal load prediction of a film-cooled test blade of a modern gas turbine. Thus, it becomes possible to take into account the interaction of internal flows, external flow, and heat transfer without the prescription of heat transfer coefficients. The focus of the investigation is laid on the leading edge part of the blade. The numerical model consists of all internal flow passages and cooling hole rows at the leading edge. Furthermore, the radial gap flow is also part of the model. The comparison with thermal pyrometer measurements shows that with respect to regions with high thermal load a qualitatively and quantitatively good agreement of the conjugate results and the measurements can be found. In particular, the region in the vicinity of the mid-span section is exposed to a higher thermal load, which requires further improvement of the cooling arrangement. Altogether the achieved results demonstrate that the conjugate calculation technique is applicable for reasonable prediction of three-dimensional thermal load of complex cooling configurations for blades.

  11. Space Shuttle Orbiter Wing-Leading-Edge Panel Thermo-Mechanical Analysis for Entry Conditions

    Science.gov (United States)

    Knight, Norman F., Jr.; Song, Kyongchan; Raju, Ivatury S.

    2010-01-01

    Linear elastic, thermo-mechanical stress analyses of the Space Shuttle Orbiter wing-leading-edge panels is presented for entry heating conditions. The wing-leading-edge panels are made from reinforced carbon-carbon and serve as a part of the overall thermal protection system. Three-dimensional finite element models are described for three configurations: integrated configuration, an independent single-panel configuration, and a local lower-apex joggle segment. Entry temperature conditions are imposed and the through-the-thickness response is examined. From the integrated model, it was concluded that individual panels can be analyzed independently since minimal interaction between adjacent components occurred. From the independent single-panel model, it was concluded that increased through-the-thickness stress levels developed all along the chord of a panel s slip-side joggle region, and hence isolated local joggle sections will exhibit the same trend. From the local joggle models, it was concluded that two-dimensional plane-strain models can be used to study the influence of subsurface defects along the slip-side joggle region of these panels.

  12. Fracture Mechanics Analyses of the Slip-Side Joggle Regions of Wing-Leading Edge Panels

    Science.gov (United States)

    Raju, Ivatury S.; Knight, Norman F., Jr.; Song, Kyongchan; Phillips, Dawn R.

    2010-01-01

    The Space Shuttle Orbiter wing comprises of 22 leading edge panels on each side of the wing. These panels are part of the thermal protection system that protects the Orbiter wings from extreme heating that take place on the reentry in to the earth atmosphere. On some panels that experience extreme heating, liberation of silicon carbon (SiC) coating was observed on the slip side regions of the panels. Global structural and local fracture mechanics analyses were performed on these panels as a part of the root cause investigation of this coating liberation anomaly. The wing-leading-edge reinforced carbon-carbon (RCC) panels, Panel 9, T-seal 10, and Panel 10, are shown in Figure 1 and the progression of the stress analysis models is presented in Figure 2. The global structural analyses showed minimal interaction between adjacent panels and the T-seal that bridges the gap between the panels. A bounding uniform temperature is applied to a representative panel and the resulting stress distribution is examined. For this loading condition, the interlaminar normal stresses showed negligible variation in the chord direction and increased values in the vicinity of the slip-side joggle shoulder. As such, a representative span wise slice on the panel can be taken and the cross section can be analyzed using plane strain analysis.

  13. PIV Study on Flow around Leading-Edge Slat of 30P30N Airfoil

    Science.gov (United States)

    Ando, Ryosuke; Onishi, Yusaku; Sakakibara, Jun

    2017-11-01

    We measured flow velocity distribution around leading-edge slat using PIV. Simultaneously, noise measurement using microphone was also performed. A leading-edge slat and main wing model having a chord length of 160 mm was placed in the tunnel with free stream velocity of about 26m/s and chord Reynolds number of 2.8 x 105. Angle of attack was changed from 4 degrees to 10 degrees at two degree intervals. In this experiment, we investigated the relationship between the unsteady flow condition and the noise. At 4 degrees in the angle of attack, vortices shedding from the slat cusp were moved to the downstream. At 6 degrees or more, flow velocity distributions show that vortices were reattached on the slat lower surface and the flow in the slat cove recirculated. In FFT analysis of noise measurement, at 6 degrees in the angle of attack, there were some peaks on low frequency area and dominant peak on high frequency area was found. At 8 degrees or more, there were also some peaks on low frequency area. But dominant peak on high frequency area disappeared.

  14. Two Functionally Distinct Sources of Actin Monomers Supply the Leading Edge of Lamellipodia

    Science.gov (United States)

    Vitriol, Eric A.; McMillen, Laura M.; Kapustina, Maryna; Gomez, Shawn M.; Vavylonis, Dimitrios; Zheng, James Q.

    2015-01-01

    Summary Lamellipodia, the sheet-like protrusions of motile cells, consist of networks of actin filaments (F-actin) regulated by the ordered assembly from and disassembly into actin monomers (G-actin). Traditionally, G-actin is thought to exist as a homogeneous pool. Here, we show that there are two functionally and molecularly distinct sources of G-actin that supply lamellipodial actin networks. G-actin originating from the cytosolic pool requires the monomer binding protein thymosin β4 (Tβ4) for optimal leading edge localization, is targeted to formins, and is responsible for creating an elevated G/F-actin ratio that promotes membrane protrusion. The second source of G-actin comes from recycled lamellipodia F-actin. Recycling occurs independently of Tβ4 and appears to regulate lamellipodia homeostasis. Tβ4-bound G-actin specifically localizes to the leading edge because it doesn’t interact with Arp2/3-mediated polymerization sites found throughout the lamellipodia. These findings demonstrate that actin networks can be constructed from multiple sources of monomers with discrete spatiotemporal functions. PMID:25865895

  15. Effects of exogenous ubiquitin in a polytrauma model with blunt chest trauma

    Science.gov (United States)

    Baker, Todd A.; Romero, Jacqueline; Bach, Harold H.; Strom, Joel A.; Gamelli, Richard L.; Majetschak, Matthias

    2013-01-01

    Objective To determine whether treatment with the CXC chemokine receptor (CXCR) 4 agonist ubiquitin results in beneficial effects in a polytrauma model consisting of bilateral femur fractures plus blunt chest trauma (Injury Severity Score 18-25). Design Treatment study. Setting Research Laboratory. Subjects Seventeen Yorkshire pigs. Interventions Intravenous (i.v.) injection of 1.5 mg/kg ubiquitin or albumin (=control) at 60 min after polytrauma. Measurements and Main Results Anesthetized, mechanically ventilated pigs underwent polytrauma, followed by a simulated 60 min shock phase. At the end of the shock phase ubiquitin or albumin were administered and animals were resuscitated to a mean arterial blood pressure of 70 mmHg until t = 420 min. After i.v. ubiquitin, ubiquitin plasma concentrations increased sixteen-fold to 2870 ± 1015 ng/mL at t = 90 min and decreased with t1/2 = 60 min. Endogenous plasma ubiquitin increased two-fold in the albumin group with peak levels of 359 ± 210 ng/mL. Plasma levels of the cognate CXCR4 ligand stromal cell-derived factor (SDF)-1α were unchanged in both groups. Ubiquitin treatment reduced arterial lactate levels and prevented a continuous decrease in arterial oxygenation, which occurred in the albumin group during resuscitation. Wet weight to dry weight ratios of the lung contralateral from the injury, heart, spleen and jejunum were lower with ubiquitin. With ubiquitin treatment, tissue levels of IL-8, IL-10, TNFα and SDF-1α were reduced in the injured lung and of IL-8 in the contralateral lung, respectively. Conclusions Administration of exogenous ubiquitin modulates the local inflammatory response, improves resuscitation, reduces fluid shifts into tissues and preserves arterial oxygenation after blunt polytrauma with lung injury. This study further supports the notion that ubiquitin is a promising protein therapeutic and implies CXCR4 as a drug target after polytrauma. PMID:22622399

  16. Numerical Prediction of the Impact of Non-Uniform Leading Edge Coatings On the Aerodynamic Performance of Compressor Airfoils

    National Research Council Canada - National Science Library

    Elmstrom, Michael

    2004-01-01

    A computational fluid dynamic (CFD) investigation is presented that provides predictions of the aerodynamic impact of uniform and non-uniform coatings applied to the leading edge of a compressor airfoil in a cascade. Using a NACA 65(12...

  17. Development of Streamwise Counter-Rotating Vortices in Flat Plate Boundary Layer Pre-set by Leading Edge Patterns

    KAUST Repository

    Hasheminejad, S.M.; Mitsudharmadi, Hatsari; Winoto, S.H.; Low, H.T.; Lua, K.B.

    2017-01-01

    Development of streamwise counter-rotating vortices induced by leading edge patterns with different pattern shape is investigated using hot-wire anemometry in the boundary layer of a flat plate. A triangular, sinusoidal and notched patterns

  18. The FAK–Arp2/3 interaction promotes leading edge advance and haptosensing by coupling nascent adhesions to lamellipodia actin

    Science.gov (United States)

    Swaminathan, Vinay; Fischer, R. S.; Waterman, Clare M.

    2016-01-01

    Cell migration is initiated in response to biochemical or physical cues in the environment that promote actin-mediated lamellipodial protrusion followed by the formation of nascent integrin adhesions (NAs) within the protrusion to drive leading edge advance. Although FAK is known to be required for cell migration through effects on focal adhesions, its role in NA formation and lamellipodial dynamics is unclear. Live-cell microscopy of FAK−/− cells with expression of phosphorylation deficient or a FERM-domain mutant deficient in Arp2/3 binding revealed a requirement for FAK in promoting the dense formation, transient stabilization, and timely turnover of NA within lamellipodia to couple actin-driven protrusion to adhesion and advance of the leading edge. Phosphorylation on Y397 of FAK promotes dense NA formation but is dispensable for transient NA stabilization and leading edge advance. In contrast, transient NA stabilization and advance of the cell edge requires FAK–Arp2/3 interaction, which promotes Arp2/3 localization to NA and reduces FAK activity. Haptosensing of extracellular matrix (ECM) concentration during migration requires the interaction between FAK and Arp2/3, whereas FAK phosphorylation modulates mechanosensing of ECM stiffness during spreading. Taken together, our results show that mechanistically separable functions of FAK in NA are required for cells to distinguish distinct properties of their environment during migration. PMID:26842895

  19. Transport Mechanisms Governing initial Leading-Edge Vortex Development on a Pitching Wing

    Science.gov (United States)

    Wabick, Kevin; Berdon, Randall; Buchholz, James; Johnson, Kyle; Thurow, Brian

    2017-11-01

    The formation and evolution of Leading Edge Vortices (LEVs) are ubiquitous in natural fliers and maneuvering wings, and have a profound impact on aerodynamic loads. The formation of an LEV is experimentally investigated on a pitching flat-plate wing of aspect-ratio 2, and dimensionless pitch rates of k = Ωc / 2 U of 0.1, 0.2, and 0.5, at a Reynolds number of 104. The sources and sinks of vorticity that contribute to the growth and evolution of the LEV are investigated at spanwise regions of interest, and their relative balance is compared to other wing kinematics, and the case of a two-dimensional pitching wing. This work is supported by the Air Force Office of Scientific Research (Grant Number FA9550-16-1-0107, Dr. Douglas Smith, program manager).

  20. Insect Residue Contamination on Wing Leading Edge Surfaces: A Materials Investigation for Mitigation

    Science.gov (United States)

    Lorenzi, Tyler M.; Wohl, Christopher J.; Penner, Ronald K.; Smith, Joseph G.; Siochi, Emilie J.

    2011-01-01

    Flight tests have shown that residue from insect strikes on aircraft wing leading edge surfaces may induce localized transition of laminar to turbulent flow. The highest density of insect populations have been observed between ground level and 153 m during light winds (2.6 -- 5.1 m/s), high humidity, and temperatures from 21 -- 29 C. At a critical residue height, dependent on the airfoil and Reynolds number, boundary layer transition from laminar to turbulent results in increased drag and fuel consumption. Although this represents a minimal increase in fuel burn for conventional transport aircraft, future aircraft designs will rely on maintaining laminar flow across a larger portion of wing surfaces to reduce fuel burn during cruise. Thus, insect residue adhesion mitigation is most critical during takeoff and initial climb to maintain laminar flow in fuel-efficient aircraft configurations. Several exterior treatments investigated to mitigate insect residue buildup (e.g., paper, scrapers, surfactants, flexible surfaces) have shown potential; however, implementation has proven to be impractical. Current research is focused on evaluation of wing leading edge surface coatings that may reduce insect residue adhesion. Initial work under NASA's Environmentally Responsible Aviation Program focused on evaluation of several commercially available products (commercial off-the-shelf, COTS), polymers, and substituted alkoxy silanes that were applied to aluminum (Al) substrates. Surface energies of these coatings were determined from contact angle data and were correlated to residual insect excrescence on coated aluminum substrates using a custom-built "bug gun." Quantification of insect excrescence surface coverage was evaluated by a series of digital photographic image processing techniques.

  1. Effects of Nose Bluntness on Hypersonic Boundary-Layer Receptivity and Stability Over Cones

    Science.gov (United States)

    Kara, Kursat; Balakumar, Ponnampalam; Kandil, Osama A.

    2011-01-01

    The receptivity to freestream acoustic disturbances and the stability properties of hypersonic boundary layers are numerically investigated for boundary-layer flows over a 5 straight cone at a freestream Mach number of 6.0. To compute the shock and the interaction of the shock with the instability waves, the Navier-Stokes equations in axisymmetric coordinates were solved. In the governing equations, inviscid and viscous flux vectors are discretized using a fifth-order accurate weighted-essentially-non-oscillatory scheme. A third-order accurate total-variation-diminishing Runge-Kutta scheme is employed for time integration. After the mean flow field is computed, disturbances are introduced at the upstream end of the computational domain. The appearance of instability waves near the nose region and the receptivity of the boundary layer with respect to slow mode acoustic waves are investigated. Computations confirm the stabilizing effect of nose bluntness and the role of the entropy layer in the delay of boundary-layer transition. The current solutions, compared with experimental observations and other computational results, exhibit good agreement.

  2. Goertler vortices in growing boundary layers: The leading edge receptivity problem, linear growth and the nonlinear breakdown stage

    Science.gov (United States)

    Hall, Philip

    1989-01-01

    Goertler vortices are thought to be the cause of transition in many fluid flows of practical importance. A review of the different stages of vortex growth is given. In the linear regime, nonparallel effects completely govern this growth, and parallel flow theories do not capture the essential features of the development of the vortices. A detailed comparison between the parallel and nonparallel theories is given and it is shown that at small vortex wavelengths, the parallel flow theories have some validity; otherwise nonparallel effects are dominant. New results for the receptivity problem for Goertler vortices are given; in particular vortices induced by free stream perturbations impinging on the leading edge of the walls are considered. It is found that the most dangerous mode of this type can be isolated and it's neutral curve is determined. This curve agrees very closely with the available experimental data. A discussion of the different regimes of growth of nonlinear vortices is also given. Again it is shown that, unless the vortex wavelength is small, nonparallel effects are dominant. Some new results for nonlinear vortices of 0(1) wavelengths are given and compared to experimental observations.

  3. A comparison of the behind armour blunt trauma effects between ceramic faced and soft body armours caused by ballistic impact

    OpenAIRE

    Lewis, E. A.; Horsfall, Ian; Watson, Celia H.

    2002-01-01

    Recently published research has characterised the behind armour blunt trauma (BABT) effects associated with high velocity ballistic impact on textile-based armour faced with a ceramic plate. Subsequently dynamic displacements, accelerations and pressures have been characterised both in Gelatine experiments and animal experiments and used to provide test methodologies. High velocity armour consists of a ceramic plate usually backed with a composite panel, which is worn over the conventional te...

  4. Unsteady lift and thrust of a 2D flapping thin airfoil in the presence of additional leading edge vortices

    Science.gov (United States)

    Alaminos-Quesada, Javier; Fernandez-Feria, Ramon

    2017-11-01

    The effect of leading-edge vortices (LEVs) on the lift, thrust and moment of a two-dimensional heaving and pitching foil is analyzed from the unsteady, linear potential theory. General expressions taking into account the effect of unsteady point vortices interacting with the oscillatory trailing wake are first derived. Then, simplified expressions for the initial stages of the growing LEV on each half-stroke are used to obtain analytical closed expressions for the main contribution of these vortices to the lift, thrust and moment. It is found that, within the linear potential framework and the Brown-Michael model, the LEV contributes to the aerodynamic forces and moment only for combined pitching and heaving motions of the foil, being a relevant contribution for sufficiently large values of the product of the reduced frequency and the amplitude of the heaving and/or pitching motions. The results are compared with available experimental data and numerical simulations. Supported by the Ministerio de Economia y Competitividad of Spain Grants No. DPI2013-40479-P and DPI2016-76151-C2-1-R.

  5. RANS-based numerical simulation and visualization of the horseshoe vortex system in the leading edge endwall region of a symmetric body

    International Nuclear Information System (INIS)

    Levchenya, A.M.; Smirnov, E.M.; Goryachev, V.D.

    2010-01-01

    This contribution is aimed at analyzing the capabilities of popular two-equation turbulence models to predict features of 3D flow fields and endwall heat transfer near the blunt edge of a symmetric body mounted on a plate. The configuration studied experimentally by Praisner and Smith is considered. Results obtained with the in-house CFD code SINF and the commercial package ANSYS-CFX are presented and compared. Prediction capabilities of the low-Re Wilcox turbulence model and two versions of the Menter SST model, the original and the modified one, are analyzed in comparison with the experimental data. Special attention is paid to grid sensitivity of the numerical solutions. Advanced visualization of the vortex structures computed is performed with author's visualization tool HDVIS. It has been established that the Wilcox model is not capable of predicting the development of a multiple-vortex system observed in the experiment upstream of the body leading edge. Both versions of the MSST model produce qualitatively correct results, with a considerable superiority of the modified version when compared with the quantitative data.

  6. Wing Leading Edge RCC Rapid Response Damage Prediction Tool (IMPACT2)

    Science.gov (United States)

    Clark, Robert; Cottter, Paul; Michalopoulos, Constantine

    2013-01-01

    This rapid response computer program predicts Orbiter Wing Leading Edge (WLE) damage caused by ice or foam impact during a Space Shuttle launch (Program "IMPACT2"). The program was developed after the Columbia accident in order to assess quickly WLE damage due to ice, foam, or metal impact (if any) during a Shuttle launch. IMPACT2 simulates an impact event in a few minutes for foam impactors, and in seconds for ice and metal impactors. The damage criterion is derived from results obtained from one sophisticated commercial program, which requires hours to carry out simulations of the same impact events. The program was designed to run much faster than the commercial program with prediction of projectile threshold velocities within 10 to 15% of commercial-program values. The mathematical model involves coupling of Orbiter wing normal modes of vibration to nonlinear or linear springmass models. IMPACT2 solves nonlinear or linear impact problems using classical normal modes of vibration of a target, and nonlinear/ linear time-domain equations for the projectile. Impact loads and stresses developed in the target are computed as functions of time. This model is novel because of its speed of execution. A typical model of foam, or other projectile characterized by material nonlinearities, impacting an RCC panel is executed in minutes instead of hours needed by the commercial programs. Target damage due to impact can be assessed quickly, provided that target vibration modes and allowable stress are known.

  7. The Multipoint Global Shape Optimization of Flying Configuration with Movable Leading Edges Flaps

    Directory of Open Access Journals (Sweden)

    Adriana NASTASE

    2012-12-01

    Full Text Available The aerodynamical global optimized (GO shape of flying configuration (FC, at two cruising Mach numbers, can be realized by morphing. Movable leading edge flaps are used for this purpose. The equations of the surfaces of the wing, of the fuselage and of the flaps in stretched position are approximated in form of superpositions of homogeneous polynomes in two variables with free coefficients. These coefficients together with the similarity parameters of the planform of the FC are the free parameters of the global optimization. Two enlarged variational problems with free boundaries occur. The first one consists in the determination of the GO shape of the wing-fuselageFC, with the flaps in retracted position, which must be of minimum drag, at higher cruising Mach number. The second enlarged variational problem consists in the determination of the GO shape of the flaps in stretched position in such a manner that the entire FC shall be of minimum drag at the second lower Mach number. The iterative optimum-optimorum (OO theory of the author is used for the solving of these both enlarged variational problems. The inviscid GO shape of the FC is used only in the first step of iteration and the own developed hybrid solutions for the compressible Navier-Stokes partial-differential equations (PDEs are used for the determination of the friction drag coefficient and up the second step of iteration of OO theory.

  8. Fracture Mechanics Analyses of Reinforced Carbon-Carbon Wing-Leading-Edge Panels

    Science.gov (United States)

    Raju, Ivatury S.; Phillips, Dawn R.; Knight, Norman F., Jr.; Song, Kyongchan

    2010-01-01

    Fracture mechanics analyses of subsurface defects within the joggle regions of the Space Shuttle wing-leading-edge RCC panels are performed. A 2D plane strain idealized joggle finite element model is developed to study the fracture behavior of the panels for three distinct loading conditions - lift-off and ascent, on-orbit, and entry. For lift-off and ascent, an estimated bounding aerodynamic pressure load is used for the analyses, while for on-orbit and entry, thermo-mechanical analyses are performed using the extreme cold and hot temperatures experienced by the panels. In addition, a best estimate for the material stress-free temperature is used in the thermo-mechanical analyses. In the finite element models, the substrate and coating are modeled separately as two distinct materials. Subsurface defects are introduced at the coating-substrate interface and within the substrate. The objective of the fracture mechanics analyses is to evaluate the defect driving forces, which are characterized by the strain energy release rates, and determine if defects can become unstable for each of the loading conditions.

  9. Mechanism of Water Droplet Breakup Near the Leading Edge of an Airfoil

    Science.gov (United States)

    Vargas, Mario; Sor, Suthyvann; Magarino, Adelaida, Garcia

    2012-01-01

    This work presents results of an experimental study on droplet deformation and breakup near the leading edge of an airfoil. The experiment was conducted in the rotating rig test cell at the Instituto Nacional de Tecnica Aeroespacial (INTA) in Madrid, Spain. The airfoil model was placed at the end of the rotating arm and a monosize droplet generator produced droplets that fell from above, perpendicular to the path of the airfoil. The interaction between the droplets and the airfoil was captured with high speed imaging and allowed observation of droplet deformation and breakup as the droplet approached the airfoil near the stagnation line. Image processing software was used to measure the position of the droplet centroid, equivalent diameter, perimeter, area, and the major and minor axes of an ellipse superimposed over the deforming droplet. The horizontal and vertical displacement of each droplet against time was also measured, and the velocity, acceleration, Weber number, Bond number, Reynolds number, and the drag coefficients were calculated along the path of the droplet to the beginning of breakup. Droplet deformation is defined and studied against main parameters. The high speed imaging allowed observation of the actual mechanism of breakup and identification of the sequence of configurations from the initiation of the breakup to the disintegration of the droplet. Results and comparisons are presented for droplets of diameters in the range of 500 to 1800 microns, and airfoil velocities of 70 and 90 m/sec.

  10. Thermostructural Evaluation of Joggle Region on the Shuttle Orbiter's Wing Leading Edge

    Science.gov (United States)

    Walker, Sandra P.; Warren, Jerry E.

    2012-01-01

    An investigation was initiated to determine the cause of coating spallation occurring on the Shuttle Orbiter's wing leading edge panels in the slip-side joggle region. The coating spallation events were observed, post flight, on differing panels on different missions. As part of the investigation, the high re-entry heating occurring on the joggles was considered here as a possible cause. Thus, a thermostructural evaluation was conducted to determine the detailed state-of-stress in the joggle region during re-entry and the feasibility of a laboratory test on a local joggle specimen to replicate this state-of-stress. A detailed three-dimensional finite element model of a panel slip-side joggle region was developed. Parametric and sensitivity studies revealed significant stresses occur in the joggle during peak heating. A critical interlaminar normal stress concentration was predicted in the substrate at the coating interface and was confined to the curved joggle region. Specifically, the high interlaminar normal stress is identified to be the cause for the occurrence of failure in the form of local subsurface material separation occurring in the slip-side joggle. The predicted critical stresses are coincident with material separations that had been observed with microscopy in joggle specimens obtained from flight panels.

  11. Turbulent Wing-Leading-Edge Correlation Assessment for the Shuttle Orbiter

    Science.gov (United States)

    King, Rudolph A.; Vaughan, Matthew P.

    2009-01-01

    This study was conducted in support of the Orbiter damage assessment activity that takes place for each Shuttle mission since STS-107 (STS - Space Transportation System). As part of the damage assessment activity, the state of boundary layer (laminar or turbulent) during reentry needs to be estimated in order to define the aerothermal environment on the Orbiter. Premature turbulence on the wing leading edge (WLE) is possible if a surface irregularity promotes early transition and the resulting turbulent wedge flow contaminates the WLE flow. The objective of this analysis is to develop a criterion to determine if and when the flow along the WLE experiences turbulent heating given an incoming turbulent boundary layer that contaminates the attachment line. The data to be analyzed were all obtained as part of the MH-13 Space Shuttle Orbiter Aerothermodynamic Test conducted on a 1.8%-scale Orbiter model at Calspan/University of Buffalo Research Center in the Large Energy National Shock Tunnels facility. A rational framework was used to develop a means to assess the state of the WLE flow on the Orbiter during reentry given a contaminated attachment-line flow. Evidence of turbulent flow on the WLE has been recently documented for a few STS missions during the Orbiter s flight history, albeit late in the reentry trajectory. The criterion developed herein will be compared to these flight results.

  12. Characterization of Unsteady Flow Structures Near Leading-Edge Slat. Part 1; PIV Measurements

    Science.gov (United States)

    Jenkins, Luther N.; Khorrami, Mehdi R.; Choudhari, Meelan

    2004-01-01

    A comprehensive computational and experimental study has been performed at the NASA Langley Research Center as part of the Quiet Aircraft Technology (QAT) Program to investigate the unsteady flow near a leading-edge slat of a two-dimensional, high-lift system. This paper focuses on the experimental effort conducted in the NASA Langley Basic Aerodynamics Research Tunnel (BART) where Particle Image Velocimetry (PIV) data was acquired in the slat cove and at the slat trailing edge of a three-element, high-lift model at 4, 6, and 8 degrees angle of attack and a freestream Mach Number of 0.17. Instantaneous velocities obtained from PIV images are used to obtain mean and fluctuating components of velocity and vorticity. The data show the recirculation in the cove, reattachment of the shear layer on the slat lower surface, and discrete vortical structures within the shear layer emanating from the slat cusp and slat trailing edge. Detailed measurements are used to examine the shear layer formation at the slat cusp, vortex shedding at the slat trailing edge, and convection of vortical structures through the slat gap. Selected results are discussed and compared with unsteady, Reynolds-Averaged Navier-Stokes (URANS) computations for the same configuration in a companion paper by Khorrami, Choudhari, and Jenkins (2004). The experimental dataset provides essential flow-field information for the validation of near-field inputs to noise prediction tools.

  13. Pressure-Velocity Correlations in the Cove of a Leading Edge Slat

    Science.gov (United States)

    Wilkins, Stephen; Richard, Patrick; Hall, Joseph

    2015-11-01

    One of the major sources of aircraft airframe noise is related to the deployment of high-lift devices, such as leading-edge slats, particularly when the aircraft is preparing to land. As the engines are throttled back, the noise produced by the airframe itself is of great concern, as the aircraft is low enough for the noise to impact civilian populations. In order to reduce the aeroacoustic noise sources associated with these high lift devices for the next generation of aircraft an experimental investigation of the correlation between multi-point surface-mounted fluctuating pressures measured via flush-mounted microphones and the simultaneously measured two-component velocity field measured via Particle Image Velocimetry (PIV) is studied. The development of the resulting shear-layer within the slat cove is studied for Re =80,000, based on the wing chord. For low Mach number flows in air, the major acoustic source is a dipole acoustic source tied to fluctuating surface pressures on solid boundaries, such as the underside of the slat itself. Regions of high correlations between the pressure and velocity field near the surface will likely indicate a strong acoustic dipole source. In order to study the underlying physical mechanisms and understand their role in the development of aeroacoustic noise, Proper Orthogonal Decomposition (POD) by the method of snapshots is employed on the velocity field. The correlation between low-order reconstructions and the surface-pressure measurements are also studied.

  14. CFD Modelling of a Pump as Turbine (PAT with Rounded Leading Edge Impellers for Micro Hydro Systems

    Directory of Open Access Journals (Sweden)

    Ismail Mohd Azlan

    2017-01-01

    Full Text Available A Pump as Turbine (PAT is one of micro hydro system components that is used to substitute a commercially available turbine due to its wide availability and low acquisition cost. However, PAT have high hydraulic losses due to differences in pump-turbine operation and hydraulic design. The fluid flowing inside the PAT is subjected to hydraulic losses due to the longer flow passage and unmatched fluid flow within the wall boundaries. This paper presents the effect of rounding the impeller leading edges of the pump on turbine performance. A CFD model of a PAT was designed to simulate virtual performance for the analysis. The aim of this study is to observe the internal hydraulic performance resulting from the changes in the performance characteristics. Highest efficiency was recorded at 17.0 l/s, an increase of 0.18%. The simulation results reveal that there is an improvement in hydraulic performance at overflow operation. The velocity vector visualization shows that there is a reduction in wake and consequently less flow separation along impeller flow passages. However, adjusting the sensitive impeller inlet geometry will also alter the velocity inlet vector and consequently change the velocity triangles for the turbo machinery system.

  15. The influence of airfoil kinematics on the formation of leading-edge vortices in bio-inspired flight

    Energy Technology Data Exchange (ETDEWEB)

    Rival, David; Prangemeier, Tim; Tropea, Cameron [Technische Universitaet Darmstadt (Germany). Institute of Fluid Mechanics and Aerodynamics

    2009-05-15

    The formation process of leading-edge vortices has been investigated experimentally using Particle Image Velocimetry. Various airfoil kinematics have been tested, including asymmetric and peak-shifted plunging motions, and are evaluated for Re = 30,000 and a reduced frequency range of 0.2{<=}k{<=}0.33. By measuring the growth in the leading-edge vortex during the dynamic-stall process, the vortex pinch-off process is examined based on the concept of an optimal vortex formation time. The various kinematics are then evaluated with respect to their associated vortex strength, timing and convection into the wake. (orig.)

  16. Method and System for Weakening Shock Wave Strength at Leading Edge Surfaces of Vehicle in Supersonic Atmospheric Flight

    Science.gov (United States)

    Daso, Endwell O. (Inventor); Pritchett, Victor E., II (Inventor); Wang, Ten-See (Inventor); Farr, Rebecca Ann (Inventor); Auslender, Aaron Howard (Inventor); Blankson, Isaiah M. (Inventor); Plotkin, Kenneth J. (Inventor)

    2015-01-01

    A method and system are provided to weaken shock wave strength at leading edge surfaces of a vehicle in atmospheric flight. One or more flight-related attribute sensed along a vehicle's outer mold line are used to control the injection of a non-heated, non-plasma-producing gas into a local external flowfield of the vehicle from at least one leading-edge surface location along the vehicle's outer mold line. Pressure and/or mass flow rate of the gas so-injected is adjusted in order to cause a Rankine-Hugoniot Jump Condition along the vehicle's outer mold line to be violated.

  17. Pediatric FAST and elevated liver transaminases: An effective screening tool in blunt abdominal trauma.

    Science.gov (United States)

    Sola, Juan E; Cheung, Michael C; Yang, Relin; Koslow, Starr; Lanuti, Emma; Seaver, Chris; Neville, Holly L; Schulman, Carl I

    2009-11-01

    The current standard for the evaluation of children with blunt abdominal trauma (BAT) consists of physical examination, screening lab values, and computed tomography (CT) scan. We sought to determine if the focused assessment with sonography for trauma (FAST) combined with elevated liver transaminases (AST/ALT) could be used as a screening tool for intra-abdominal injury (IAI) in pediatric patients with BAT. Registry data at a level 1 trauma center was retrospectively reviewed from 1991-2007. Data collected on BAT patients under the age of 16 y included demographics, injury mechanism, ISS, GCS, imaging studies, serum ALT and AST levels, and disposition. AST and ALT were considered positive if either one was >100 IU/L. Overall, 3171 cases were identified. A total of 1008 (31.8%) patients received CT scan, 1148 (36.2%) had FAST, and 497 (15.7%) patients received both. Of the 497 patients, 400 (87.1%) also had AST and ALT measured. FAST was 50% sensitive, 91% specific, with a positive predictive value (PPV) of 68%, negative predictive value (NPV) of 83%, and accuracy of 80%. Combining FAST with elevated AST or ALT resulted in a statistically significant increase in all measures (sensitivity 88%, specificity 98%, PPV 94%, NPV 96%, accuracy 96%). FAST combined with AST or ALT > 100 IU/L is an effective screening tool for IAI in children following BAT. Pediatric patients with a negative FAST and liver transaminases < 100 IU/L should be observed rather than subjected to the radiation risk of CT.

  18. Data acquisition electronics for gamma ray emission tomography using width-modulated leading-edge discriminators

    Energy Technology Data Exchange (ETDEWEB)

    Lage, E; Tapias, G; Villena, J; Desco, M; Vaquero, J J, E-mail: desco@mce.hggm.e [Unidad de Medicina y CirugIa Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain)

    2010-08-07

    We present a new high-performance and low-cost approach for implementing radiation detection acquisition systems. The basic elements used are charge-integrating ADCs and a set of components encapsulated in an HDL (hardware definition language) library which makes it possible to implement several acquisition tasks such as time pickoff and coincidence detection using a new and simple trigger technique that we name WMLET (width-modulated leading-edge timing). As proof of concept, a 32-channel hybrid PET/SPECT acquisition system based on these elements was developed and tested. This demonstrator consists of a master module responsible for the generation and distribution of trigger signals, 2 x 16-channel ADC cards (12-bit resolution) for data digitization and a 32-bit digital I/O PCI card for handling data transmission to a personal computer. System characteristics such as linearity, maximum transmission rates or timing resolution in coincidence mode were evaluated with test and real detector signals. Imaging capabilities of the prototype were also evaluated using different detector configurations. The performance tests showed that this implementation is able to handle data rates in excess of 600k events s{sup -1} when acquiring simultaneously 32 channels (96-byte events). ADC channel linearity is >98.5% in energy quantification. Time resolution in PET mode for the tested configurations ranges from 3.64 ns FWHM to 7.88 ns FWHM when signals from LYSO-based detectors are used. The measured energy resolution matched the expected values for the detectors evaluated and single elements of crystal matrices can be neatly separated in the acquired flood histograms.

  19. Data acquisition electronics for gamma ray emission tomography using width-modulated leading-edge discriminators

    Science.gov (United States)

    Lage, E.; Tapias, G.; Villena, J.; Desco, M.; Vaquero, J. J.

    2010-08-01

    We present a new high-performance and low-cost approach for implementing radiation detection acquisition systems. The basic elements used are charge-integrating ADCs and a set of components encapsulated in an HDL (hardware definition language) library which makes it possible to implement several acquisition tasks such as time pickoff and coincidence detection using a new and simple trigger technique that we name WMLET (width-modulated leading-edge timing). As proof of concept, a 32-channel hybrid PET/SPECT acquisition system based on these elements was developed and tested. This demonstrator consists of a master module responsible for the generation and distribution of trigger signals, 2 × 16-channel ADC cards (12-bit resolution) for data digitization and a 32-bit digital I/O PCI card for handling data transmission to a personal computer. System characteristics such as linearity, maximum transmission rates or timing resolution in coincidence mode were evaluated with test and real detector signals. Imaging capabilities of the prototype were also evaluated using different detector configurations. The performance tests showed that this implementation is able to handle data rates in excess of 600k events s-1 when acquiring simultaneously 32 channels (96-byte events). ADC channel linearity is >98.5% in energy quantification. Time resolution in PET mode for the tested configurations ranges from 3.64 ns FWHM to 7.88 ns FWHM when signals from LYSO-based detectors are used. The measured energy resolution matched the expected values for the detectors evaluated and single elements of crystal matrices can be neatly separated in the acquired flood histograms.

  20. Tropomyosin Promotes Lamellipodial Persistence by Collaborating with Arp2/3 at the Leading Edge.

    Science.gov (United States)

    Brayford, Simon; Bryce, Nicole S; Schevzov, Galina; Haynes, Elizabeth M; Bear, James E; Hardeman, Edna C; Gunning, Peter W

    2016-05-23

    At the leading edge of migrating cells, protrusion of the lamellipodium is driven by Arp2/3-mediated polymerization of actin filaments [1]. This dense, branched actin network is promoted and stabilized by cortactin [2, 3]. In order to drive filament turnover, Arp2/3 networks are remodeled by proteins such as GMF, which blocks the actin-Arp2/3 interaction [4, 5], and coronin 1B, which acts by directing SSH1L to the lamellipodium where it activates the actin-severing protein cofilin [6, 7]. It has been shown in vitro that cofilin-mediated severing of Arp2/3 actin networks results in the generation of new pointed ends to which the actin-stabilizing protein tropomyosin (Tpm) can bind [8]. The presence of Tpm in lamellipodia, however, is disputed in the literature [9-19]. Here, we report that the Tpm isoforms 1.8/9 are enriched in the lamellipodium of fibroblasts as detected with a novel isoform-specific monoclonal antibody. RNAi-mediated silencing of Tpm1.8/9 led to an increase of Arp2/3 accumulation at the cell periphery and a decrease in the persistence of lamellipodia and cell motility, a phenotype consistent with cortactin- and coronin 1B-deficient cells [2, 7]. In the absence of coronin 1B or cofilin, Tpm1.8/9 protein levels are reduced while, conversely, inhibition of Arp2/3 with CK666 leads to an increase in Tpm1.8/9 protein. These findings establish a novel regulatory mechanism within the lamellipodium whereby Tpm collaborates with Arp2/3 to promote lamellipodial-based cell migration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. "Partners in Science": A Model Cooperative Program Introducing High School Teachers and Students to Leading-Edge Pharmaceutical Science

    Science.gov (United States)

    Woska, Joseph R., Jr.; Collins, Danielle M.; Canney, Brian J.; Arcario, Erin L.; Reilly, Patricia L.

    2005-01-01

    "Partners in Science" is a cooperative program between Boehringer Ingelheim Pharmaceuticals, Inc. and area high schools in the community surrounding our Connecticut campus. It is a two-phase program that introduces high school students and teachers to the world of drug discovery and leading-edge pharmaceutical research. Phase 1 involves…

  2. Owl-inspired leading-edge serrations play a crucial role in aerodynamic force production and sound suppression.

    Science.gov (United States)

    Rao, Chen; Ikeda, Teruaki; Nakata, Toshiyuki; Liu, Hao

    2017-07-04

    Owls are widely known for silent flight, achieving remarkably low noise gliding and flapping flights owing to their unique wing morphologies, which are normally characterized by leading-edge serrations, trailing-edge fringes and velvet-like surfaces. How these morphological features affect aerodynamic force production and sound suppression or noise reduction, however, is still not well known. Here we address an integrated study of owl-inspired single feather wing models with and without leading-edge serrations by combining large-eddy simulations (LES) with particle-image velocimetry (PIV) and force measurements in a low-speed wind tunnel. With velocity and pressure spectra analysis, we demonstrate that leading-edge serrations can passively control the laminar-turbulent transition over the upper wing surface, i.e. the suction surface at all angles of attack (0°    15° where owl wings often reach in flight. Our results indicate that the owl-inspired leading-edge serrations may be a useful device for aero-acoustic control in biomimetic rotor designs for wind turbines, aircrafts, multi-rotor drones as well as other fluid machinery.

  3. Peridotite carbonation at the leading edge of the mantle wedge: OmDP Site BT1

    Science.gov (United States)

    Kelemen, P. B.; Godard, M.; Johnson, K. T. M.; Okazaki, K.; Manning, C. E.; Urai, J. L.; Michibayashi, K.; Harris, M.; Coggon, J. A.; Teagle, D. A. H.; Phase I Science Party, T. O. D. P.

    2017-12-01

    immobile on a 1-10 m scale during introduction of C, O, lesser Ca, minor Fe, and fluid mobile trace elements (Godard ea AGU 17) during transformation of Mg-silicates to carbonate + quartz. With prior and coeval serpentinization, this implies 80% solid volume expansion compared to unaltered peridotite, in a zone >200 m thick at the leading edge of the mantle wedge.

  4. IMPROVING THE AERODYNAMICS OF A TRANSPORT AIRCRAFT WING USING A DELTA PLANFORM WINGTIP LEADING EDGE EXTENSION

    Directory of Open Access Journals (Sweden)

    D. Gueraiche

    2018-01-01

    Full Text Available The article explores the possibility of improving the aerodynamic properties of a supercritical-airfoil wing, typical for a modern passenger aircraft, using delta planform passive devices of large relative areas, installed along the leading edge at the wing tip. Delta extensions of various configurations were considered to be used as wingtip devices, potentially improving or completely replacing classical R. Whitcomb winglets. As a result of two- and three-dimensional CFD simulations performed on DLR-F4 wing-body prototype, the potential advantage of these devices was confirmed, particularly when they are installed in a combination with an elliptical planform, largely swept, raked winglet in terms of reducing the induced drag and increasing the aerodynamic lift-to-drag ratio at flight angles of attack. The growth in lift-to-drag ratio applying these devices owes it solely to the drop in drag, without increasing the lift force acting on the wing. In comparison to the classical winglets that lead to a general increase in lifting and lateral forces acting on the wing structure, resulting in a weight penalty, the Wingtip Ledge Edge Triangular Extension (WLETE yields the same L/D ratio increase, but with a much smaller increase in the wing loading. A study has been made of the characteristics of the local (modified airfoil in the WLETE zone in a two-dimensional flow context, and a quantitative analysis has been conducted of the influence of WLETE on both the profile and induced drag components, as well as its influence on the overall lift coefficient of the wing. The resulted synthesis of the WLETE influence on the wing L/D ratio will consist of its influence on each of these components. A comparison of the efficiency of using delta extensions against classical winglets was carried out in a multidisciplinary way, where in addition to the changes in aerodynamic coefficients of lift and drag, the increments of magnitude and distribution of the loads

  5. An experimental analysis of critical factors involved in the breakdown process of leading edge vortex flows. Ph.D. Thesis

    Science.gov (United States)

    Visser, Kenneth D.

    1991-01-01

    Experimental crosswire measurements of the flowfield above a 70 and 75 degree flat plate delta wing were performed at a Reynolds number of 250,000. Survey grids were taken normal to the platform at a series of chordwise locations for angles of attack of 20 and 30 degrees. Axial and azimuthal vorticity distributions were derived from the velocity fields. The dependence of circulation on distance from the vortex core as well as on chordwise location was examined. The effects of nondimensionalization in comparison with other experimental data was made. The circulation distribution scales with the local semispan and grows approximately linearly in the chordwise direction. For regions of the flow outside of the vortex subcore, the circulation at any chordwise station was observed to vary logarithmically with distance from the vortex axis. The circulation was also found to increase linearly with angle of incidence at a given chordwise station. A reduction in the local circulation about the vortex axis occurred at breakdown. The spanwise distribution of axial vorticity was severely altered through the breakdown region and the spanwise distribution of axial vorticity present appeared to reach a maximum immediately preceding breakdown. The local concentration of axial vorticity about the vortex axis was reduced while the magnitude of the azimuthal vorticity decreased throughout the breakdown zone. The axial vorticity components with a negative sense, found in the secondary vortex, remained unaffected by changes in wing sweep or angle of attack, in direct contrast to the positive components. The inclusion of the local wing geometry into a previously derived correlation parameter indicated that the circulation of growing leading edge vortex flows were similar at corresponding radii from the vortex axis. It was concluded that the flow over a delta wing, upstream of the breakdown regions and away from the apex and trailing edge regions, is conical. In addition, the dominating

  6. Experimental Investigation of Effect of the Sail with Leading Edge Fillet on Flow around a Submarine

    OpenAIRE

    Mohsen Rahmany; Amir Hamzeh Farajollahi; Mojtaba Dehghan Manshadi

    2016-01-01

    Because of connecting the various appendages of submarine to the main body the vortices have been created that disrupt the flow uniformity and make the undesirable features such as vortex formation to flow. Vortices that have been created due to the connectivity of sail to the body of submarines have a significant impact on non-uniformity of submarine wake at location of the propeller disc. In present research the use of hot wire anemometer has created vertical flow field in back of the two s...

  7. Active control of noise amplification in the flow over a square leading-edge flat plate utilizing DBD plasma actuator

    Science.gov (United States)

    Yadong, HUANG; Benmou, ZHOU

    2018-05-01

    Perturbation is generally considered as the flow noise, and its energy can gain transient growth in the separation bubble. The amplified perturbations may cause unstable Kelvin–Helmohltz vortices which induce the three-dimensional transition. Active control of noise amplification via dielectric barrier discharge plasma actuator in the flow over a square leading-edge flat plate is numerically studied. The actuator is installed near the plate leading-edge where the separation bubble is formed. The maximum energy amplification of perturbations is positively correlated with the separation bubble scale which decreases with the increasing control parameters. As the magnitude of noise amplification is reduced, the laminar-turbulent transition is successfully suppressed.

  8. An experimental investigation of the shear-layer and acoustic sources produced by a leading edge slat

    Science.gov (United States)

    Wilkins, Stephen; Richard, Patrick; Hall, Joseph; Turbulence; Flow Noise Laboratory Team

    2013-11-01

    Leading edge slats are a common addition to airfoils as part of a high lift configuration employed during take-off and landing; the unsteady flow caused by these slats is a major contributor to the overal airframe noise. As the next generation of aircraft seeks to reduce these noise concerns, a better understanding of the sources of aeroacoustic noise generation is sought. Particle Image Velocimetry (PIV) and simultaneous multipoint measurements of the unsteady surface pressure are used herein to investigate the unsteady flow around a leading edge slat coupled with an airfoil for several different configurations and a range of Reynolds numbers (Re = 156 , 000 to Re = 1 . 2 million based on the wing chord). Shear-layer development off the slat cusp and the related unsteady vortex structures are examined in detail to better establish and understand the mechanisms responsible for the generation of aeroacoustic slat noise. The authors are grateful for the support provided by GARDN.

  9. NUMERICAL AND EXPERIMENTAL INVESTIGATION ON THE FLUTTER OF CANTILEVERED PLATES WITH FREE LEADING EDGE IN AXIAL FLOW

    Directory of Open Access Journals (Sweden)

    I. P. G. SOPAN RAHTIKA

    2017-10-01

    Full Text Available This paper reports the results of the numerical and experimental investigation on the flutter of cantilevered thin flat plates with free leading edge in axial flow. Three methods of in-vacuo modal analyses of the plates are presented and compared in this paper, namely the finite element modal analysis using ANSYS STUDENT Modal, the analytical beam model, and the experimental modal analysis. In this study, the numerical Fluid Structure Interaction was performed using the ANSYS STUDENT Structural Transient Analysis and ANSYS STUDENT CFX to obtain the system response in the time domain. Furthermore, the experimental investigation was conducted in the smooth flow of a wind tunnel to observe the flutter speeds of the plates and their vibration characteristics. The plates’ vibration behaviors were mapped on the normalized air speed. The normalized air speed can be divided into four speed zones based on the experimental plates’ vibration characteristics. A new finding observed during the experiments is the presence of intermittent vibration behavior that is unique to the free leading edge configuration and has not been reported by other researchers in the earlier references of the clamped leading edge configuration. The potential application of this Fluid Structure Interaction configuration to wind harvesting is inquired.

  10. Materials, Manufacturing, and Test Development of a Composite Fan Blade Leading Edge Subcomponent for Improved Impact Resistance

    Science.gov (United States)

    Miller, Sandi G.; Handschuh, Katherine; Sinnott, Matthew J.; Kohlman, Lee W.; Roberts, Gary D.; Martin, Richard E.; Ruggeri, Charles R.; Pereira, J. Michael

    2015-01-01

    Application of polymer matrix composite materials for jet engine fan blades is becoming attractive as an alternative to metallic blades; particularly for large engines where significant weight savings are recognized on moving to a composite structure. However, the weight benefit of the composite is offset by a reduction of aerodynamic efficiency resulting from a necessary increase in blade thickness; relative to the titanium blades. Blade dimensions are largely driven by resistance to damage on bird strike. Further development of the composite material is necessary to allow composite blade designs to approximate the dimensions of a metallic fan blade. The reduction in thickness over the state of the art composite blades is expected to translate into structural weight reduction, improved aerodynamic efficiency, and therefore reduced fuel consumption. This paper presents test article design, subcomponent blade leading edge fabrication, test method development, and initial results from ballistic impact of a gelatin projectile on the leading edge of composite fan blades. The simplified test article geometry was developed to realistically simulate a blade leading edge while decreasing fabrication complexity. Impact data is presented on baseline composite blades and toughened blades; where a considerable improvement to impact resistance was recorded.

  11. Model for adhesion clutch explains biphasic relationship between actin flow and traction at the cell leading edge

    Science.gov (United States)

    Craig, Erin M.; Stricker, Jonathan; Gardel, Margaret L.; Mogilner, Alex

    2015-01-01

    Cell motility relies on the continuous reorganization of a dynamic actin-myosin-adhesion network at the leading edge of the cell, in order to generate protrusion at the leading edge and traction between the cell and its external environment. We analyze experimentally measured spatial distributions of actin flow, traction force, myosin density, and adhesion density in control and pharmacologically perturbed epithelial cells in order to develop a mechanical model of the actin-adhesion-myosin self-organization at the leading edge. A model in which the F-actin network is treated as a viscous gel, and adhesion clutch engagement is strengthened by myosin but weakened by actin flow, can explain the measured molecular distributions and correctly predict the spatial distributions of the actin flow and traction stress. We test the model by comparing its predictions with measurements of the actin flow and traction stress in cells with fast and slow actin polymerization rates. The model predicts how the location of the lamellipodium-lamellum boundary depends on the actin viscosity and adhesion strength. The model further predicts that the location of the lamellipodium-lamellum boundary is not very sensitive to the level of myosin contraction. PMID:25969948

  12. Unsteady behavior of leading-edge vortex and diffuser stall in a centrifugal compressor with vaned diffuser

    Science.gov (United States)

    Fujisawa, Nobumichi; Hara, Shotaro; Ohta, Yutaka

    2016-02-01

    The characteristics of a rotating stall of an impeller and diffuser and the evolution of a vortex generated at the diffuser leading-edge (i.e., the leading-edge vortex (LEV)) in a centrifugal compressor were investigated by experiments and numerical analysis. The results of the experiments revealed that both the impeller and diffuser rotating stalls occurred at 55 and 25 Hz during off-design flow operation. For both, stall cells existed only on the shroud side of the flow passages, which is very close to the source location of the LEV. According to the CFD results, the LEV is made up of multiple vortices. The LEV is a combination of a separated vortex near the leading- edge and a longitudinal vortex generated by the extended tip-leakage flow from the impeller. Therefore, the LEV is generated by the accumulation of vorticity caused by the velocity gradient of the impeller discharge flow. In partial-flow operation, the spanwise extent and the position of the LEV origin are temporarily transmuted. The LEV develops with a drop in the velocity in the diffuser passage and forms a significant blockage within the diffuser passage. Therefore, the LEV may be regarded as being one of the causes of a diffuser stall in a centrifugal compressor.

  13. Myosin X is recruited to nascent focal adhesions at the leading edge and induces multi-cycle filopodial elongation.

    Science.gov (United States)

    He, Kangmin; Sakai, Tsuyoshi; Tsukasaki, Yoshikazu; Watanabe, Tomonobu M; Ikebe, Mitsuo

    2017-10-20

    Filopodia protrude from the leading edge of cells and play important roles in cell motility. Here we report the mechanism of myosin X (encoded by Myo10)-induced multi-cycle filopodia extension. We found that actin, Arp2/3, vinculin and integrin-β first accumulated at the cell's leading edge. Myosin X was then gathered at these sites, gradually clustered by lateral movement, and subsequently initiated filopodia formation. During filopodia extension, we found the translocation of Arp2/3 and integrin-β along filopodia. Arp2/3 and integrin-β then became localized at the tip of filopodia, from where myosin X initiated the second extension of filopodia with a change in extension direction, thus producing long filopodia. Elimination of integrin-β, Arp2/3 and vinculin by siRNA significantly attenuated the myosin-X-induced long filopodia formation. We propose the following mechanism. Myosin X accumulates at nascent focal adhesions at the cell's leading edge, where myosin X promotes actin convergence to create the base of filopodia. Then myosin X moves to the filopodia tip and attracts integrin-β and Arp2/3 for further actin nucleation. The tip-located myosin X then initiates the second cycle of filopodia elongation to produce the long filopodia.

  14. Studies Conducted of Sodium Carbonate Contaminant Found on the Wing Leading Edge and the Nose Cap of the Space Shuttle Orbiter

    Science.gov (United States)

    Jacobson, Nathan S.; Palou, Jaime J.

    2003-01-01

    In early 2001, three of the space shuttle orbiters were found to have a sodium carbonate contaminant on the wing leading edge and nose cap. These parts are made of a reinforced carbon/carbon material protected by silicon carbide (SiC) and a glass coating. The glass coating is known as Type A and is primarily sodium silicate with particles of SiC. NASA Glenn Research Center's Environmental Durability Branch was asked to determine the chemistry of this deposit formation and assess any possible detrimental effects. At low temperatures, the reverse reaction is favorable. Previous studies of the corrosion of glass show that carbon dioxide in the presence of water does form sodium carbonate on sodium silicate glass (ref. 1). It is quite likely that a similar scenario exists for the orbiter wing leading edge. All three orbiters that formed sodium carbonate were exposed to rain. This formation of sodium carbonate was duplicated in the laboratory. The Type A glass, which coats the wing leading edge and nose cap, was made in a freestanding form and exposed to water in two separate experiments. In one set of experiments, the coating was placed in a petri dish filled with water. As the water evaporated, sodium carbonate formed. In another case, water was slowly dripped on the coating and sodium carbonate formed. The sodium carbonate was detected by chemical analysis and, in some cases, xray diffraction showed a hydrated sodium carbonate. The next step was to examine possible detrimental effects of this sodium carbonate. There are three likely scenarios for the sodium carbonate deposit: (1) it may be removed with a simple rinse, (2) it may remain and flow back into the Type A glass after heating during reentry, or (3) it may remain and flow onto unprotected SiC and/or other parts after heating during reentry. The effect of case 1 is to remove the Na2O constituent from the Type A glass, thus decreasing its effectiveness as a sealant. Even so, overall, it is probably the best

  15. Effects of toxic cyanobacteria and ammonia on flesh quality of blunt snout bream (Megalobrama amblycephala).

    Science.gov (United States)

    Wang, Li; Chen, Chuanyue; Liu, Wanjing; Xia, Hu; Li, Jian; Zhang, Xuezhen

    2017-03-01

    Toxic cyanobacterial blooms result in the production of an organic biomass containing cyanotoxins (e.g. microcystins) and an elevated ammonia concentration in the water environment. The ingestion of toxic cyanobacteria and exposure to ammonia are grave hazards for fish. The present study assessed the effects of dietary toxic cyanobacteria and ammonia exposure on the flesh quality of blunt snout bream (Megalobrama amblycephala). Dietary toxic cyanobacteria and ammonia exposure had no impact on fish growth performance, fillet proximate composition and drip loss, whereas it significantly decreased fillet total amino acids, total essential amino acids, hardness and gumminess, and increased fillet ultimate pH as well as malondialdehyde content. However, there was no significant interaction between dietary toxic cyanobacteria and ammonia exposure on these parameters. Additionally, dietary toxic cyanobacteria significantly increased fillet initial pH, thaw loss and protein carbonyl content, whereas ammonia exposure did not. The results of the present study indicate that dietary toxic cyanobacteria and ammonia exposure reduced the quality of blunt snout bream fillet. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  16. Effect of surface roughness on the heating rates of large-angled hypersonic blunt cones

    Science.gov (United States)

    Irimpan, Kiran Joy; Menezes, Viren

    2018-03-01

    Surface-roughness caused by the residue of an ablative Thermal Protection System (TPS) can alter the turbulence level and surface heating rates on a hypersonic re-entry capsule. Large-scale surface-roughness that could represent an ablated TPS, was introduced over the forebody of a 120° apex angle blunt cone, in order to test for its influence on surface heating rates in a hypersonic freestream of Mach 8.8. The surface heat transfer rates measured on smooth and roughened models under the same freestream conditions were compared. The hypersonic flow-fields of the smooth and rough-surfaced models were visualized to analyse the flow physics. Qualitative numerical simulations and pressure measurements were carried out to have an insight into the high-speed flow physics. Experimental observations under moderate Reynolds numbers indicated a delayed transition and an overall reduction of 17-46% in surface heating rates on the roughened model.

  17. Numerical and experimental study on the ability of dynamic roughness to alter the development of a leading edge vortex

    Science.gov (United States)

    Griffin, Christopher D.

    Dynamic stall is an unsteady aerodynamic phenomenon garnering much research interest because it occurs in a variety of applications. For example, dynamic stall is known to occur on helicopter rotor blades, wind turbines, high maneuvering military aircraft, and flapping wings. Dynamic stall occurs when an aerodynamic lifting device, such as an airfoil, wing, or turbomachine blade, undergoes a rapid pitching motion. It also occurs on lifting devices that are impulsively started at high angles of attack. Dynamic stall can "delay" aerodynamic stall to angles of attack that are significantly beyond the static stall angle of attack. During dynamic stall a large leading edge vortex (LEV) is formed, which creates greater fluid acceleration over the wing or airfoil, thus sustaining lift. As this vortex is shed downstream stall eventually occurs and there is an abrupt increase in drag and a large shift in pitching moment. Research has been performed to better understand the mechanisms occurring during dynamic stall in an effort to find ways to best take advantage of the increased lift associated with dynamic stall, but avoid the downfalls that occur once stall is initiated. Few attempts have been made to alter the LEV, and these attempts have used methods associated with laminar boundary layer separation control. Although these methods have shown promise, they suffer from the drawback that they exhaust more energy than is gained by flow control, while also only being effective at certain flight regimes. The research described herein documents the first study on the ability of dynamic roughness to alter the LEV encountered on a rapidly pitching airfoil. Both numerical and experimental studies were performed, including two-dimensional and three-dimensional computational fluid dynamics (CFD) simulations as well as stereo and planar particle image velocimetry (PIV) experiments. Evidence for the ability of small scale dynamic roughness to alter the development of the LEV was

  18. Effect of analgesia on the changes in respiratory parameters in blunt chest injury with multiple rib fractures.

    Science.gov (United States)

    Ekpe, Eyo Effiong; Eyo, Catherine

    2017-01-01

    Blunt chest injury with multiple rib fractures can result in such complications as pneumonia, atelectasis, bronchiectasis, empyema thoracis, acute respiratory distress syndrome, and prolonged Intensive Care Unit and hospital stay, with its concomitant mortality. These may be prevented or reduced by good analgesic therapy which is the subject of this study. This was a prospective study of effects of analgesia on changes in pulmonary functions of patients with traumatic multiple rib fractures resulting from blunt chest injury. There were 64 adult patients who were studied with multiple rib fractures caused by blunt chest trauma. Of these patients, 54 (84.4%) were male and 10 (15.6%) were female. Motorcycle (popularly known as "okada") and tricycle (popularly known as keke napep) accidents significantly accounted for the majority of the multiple rib fractures, that is, in 50 (78.1%) of the patients. Before analgesic administration, no patient had a normal respiratory rate, but at 1 h following the administration of analgesic, 21 (32.8%) of patients recorded normal respiratory rates and there was a significant reduction in the number (10.9% vs. 39.1%) of patients with respiratory rates> 30 breaths/min. Before commencement of analgesic, no patient recorded up to 99% of oxygen saturation (SpO2) as measured by pulse oximeter, while 43.8% recorded SpO2of 96%. This improved after 1 h of administration of analgesics to SpO2of 100% in 18.8% of patients and 99% in 31.3% of patients and none recording SpO2of 100% of predicted while only 9 (14.1%) patients were able to achieve a PEFR value in the range of 91%-100% of predicted value. One hour after analgesia, a total of 6 (9.4%) patients were able to achieve PEFR values> 100% predicted, while 35 (54.7%) patients achieved PEFR values in the range of 91%-100% predicted. Adequate analgesia is capable of reversing the negative effects of chest pain of traumatic multiple rib fractures on pulmonary function parameters through

  19. Applicability of linearized-theory attached-flow methods to design and analysis of flap systems at low speeds for thin swept wings with sharp leading edges

    Science.gov (United States)

    Carlson, Harry W.; Darden, Christine M.

    1987-01-01

    Low-speed experimental force and data on a series of thin swept wings with sharp leading edges and leading and trailing-edge flaps are compared with predictions made using a linearized-theory method which includes estimates of vortex forces. These comparisons were made to assess the effectiveness of linearized-theory methods for use in the design and analysis of flap systems in subsonic flow. Results demonstrate that linearized-theory, attached-flow methods (with approximate representation of vortex forces) can form the basis of a rational system for flap design and analysis. Even attached-flow methods that do not take vortex forces into account can be used for the selection of optimized flap-system geometry, but design-point performance levels tend to be underestimated unless vortex forces are included. Illustrative examples of the use of these methods in the design of efficient low-speed flap systems are included.

  20. TRIAGE OF PATIENTS TO ANGIOGRAPHY FOR DETECTION OF AORTIC RUPTURE AFTER BLUNT CHEST TRAUMA - COST-EFFECTIVENESS ANALYSIS OF USING CT

    NARCIS (Netherlands)

    HUNINK, MGM; BOS, JJ

    OBJECTIVE. The purpose of this study was to evaluate the cost-effectiveness of dynamic chest CT, compared with plain chest radiography and immediate angiography, in deciding when angiography should be performed in hemodynamically stable patients with suspected aortic rupture after blunt chest

  1. Superior Reproducibility of the Leading to Leading Edge and Inner to Inner Edge Methods in the Ultrasound Assessment of Maximum Abdominal Aortic Diameter

    DEFF Research Database (Denmark)

    Borgbjerg, Jens; Bøgsted, Martin; Lindholt, Jes S

    2018-01-01

    Objectives: Controversy exists regarding optimal caliper placement in ultrasound assessment of maximum abdominal aortic diameter. This study aimed primarily to determine reproducibility of caliper placement in relation to the aortic wall with the three principal methods: leading to leading edge...

  2. The non-receptor tyrosine kinase Lyn controls neutrophil adhesion by recruiting the CrkL–C3G complex and activating Rap1 at the leading edge

    Science.gov (United States)

    He, Yuan; Kapoor, Ashish; Cook, Sara; Liu, Shubai; Xiang, Yang; Rao, Christopher V.; Kenis, Paul J. A.; Wang, Fei

    2011-01-01

    Establishing new adhesions at the extended leading edges of motile cells is essential for stable polarity and persistent motility. Despite recent identification of signaling pathways that mediate polarity and chemotaxis in neutrophils, little is known about molecular mechanisms governing cell–extracellular-matrix (ECM) adhesion in these highly polarized and rapidly migrating cells. Here, we describe a signaling pathway in neutrophils that is essential for localized integrin activation, leading edge attachment and persistent migration during chemotaxis. This pathway depends upon Gi-protein-mediated activation and leading edge recruitment of Lyn, a non-receptor tyrosine kinase belonging to the Src kinase family. We identified the small GTPase Rap1 as a major downstream effector of Lyn to regulate neutrophil adhesion during chemotaxis. Depletion of Lyn in neutrophil-like HL-60 cells prevented chemoattractant-induced Rap1 activation at the leading edge of the cell, whereas ectopic expression of Rap1 largely rescued the defects induced by Lyn depletion. Furthermore, Lyn controls spatial activation of Rap1 by recruiting the CrkL–C3G protein complex to the leading edge. Together, these results provide novel mechanistic insights into the poorly understood signaling network that controls leading edge adhesion during chemotaxis of neutrophils, and possibly other amoeboid cells. PMID:21628423

  3. Is non-operative management safe and effective for all splenic blunt trauma? A systematic review.

    Science.gov (United States)

    Cirocchi, Roberto; Boselli, Carlo; Corsi, Alessia; Farinella, Eriberto; Listorti, Chiara; Trastulli, Stefano; Renzi, Claudio; Desiderio, Jacopo; Santoro, Alberto; Cagini, Lucio; Parisi, Amilcare; Redler, Adriano; Noya, Giuseppe; Fingerhut, Abe

    2013-09-03

    The goal of non-operative management (NOM) for blunt splenic trauma (BST) is to preserve the spleen. The advantages of NOM for minor splenic trauma have been extensively reported, whereas its value for the more severe splenic injuries is still debated. The aim of this systematic review was to evaluate the available published evidence on NOM in patients with splenic trauma and to compare it with the operative management (OM) in terms of mortality, morbidity and duration of hospital stay. For this systematic review we followed the "Preferred Reporting Items for Systematic Reviews and Meta-analyses" statement. A systematic search was performed on PubMed for studies published from January 2000 to December 2011, without language restrictions, which compared NOM vs. OM for splenic trauma injuries and which at least 10 patients with BST. We identified 21 non randomized studies: 1 Clinical Controlled Trial and 20 retrospective cohort studies analyzing a total of 16,940 patients with BST. NOM represents the gold standard treatment for minor splenic trauma and is associated with decreased mortality in severe splenic trauma (4.78% vs. 13.5% in NOM and OM, respectively), according to the literature. Of note, in BST treated operatively, concurrent injuries accounted for the higher mortality. In addition, it was not possible to determine post-treatment morbidity in major splenic trauma. The definition of hemodynamic stability varied greatly in the literature depending on the surgeon and the trauma team, representing a further bias. Moreover, data on the remaining analyzed outcomes (hospital stay, number of blood transfusions, abdominal abscesses, overwhelming post-splenectomy infection) were not reported in all included studies or were not comparable, precluding the possibility to perform a meaningful cumulative analysis and comparison. NOM of BST, preserving the spleen, is the treatment of choice for the American Association for the Surgery of Trauma grades I and II

  4. Blunt Chest Trauma in Mice after Cigarette Smoke-Exposure: Effects of Mechanical Ventilation with 100% O2.

    Science.gov (United States)

    Wagner, Katja; Gröger, Michael; McCook, Oscar; Scheuerle, Angelika; Asfar, Pierre; Stahl, Bettina; Huber-Lang, Markus; Ignatius, Anita; Jung, Birgit; Duechs, Matthias; Möller, Peter; Georgieff, Michael; Calzia, Enrico; Radermacher, Peter; Wagner, Florian

    2015-01-01

    Cigarette smoking (CS) aggravates post-traumatic acute lung injury and increases ventilator-induced lung injury due to more severe tissue inflammation and apoptosis. Hyper-inflammation after chest trauma is due to the physical damage, the drop in alveolar PO2, and the consecutive hypoxemia and tissue hypoxia. Therefore, we tested the hypotheses that 1) CS exposure prior to blunt chest trauma causes more severe post-traumatic inflammation and thereby aggravates lung injury, and that 2) hyperoxia may attenuate this effect. Immediately after blast wave-induced blunt chest trauma, mice (n=32) with or without 3-4 weeks of CS exposure underwent 4 hours of pressure-controlled, thoraco-pulmonary compliance-titrated, lung-protective mechanical ventilation with air or 100% O2. Hemodynamics, lung mechanics, gas exchange, and acid-base status were measured together with blood and tissue cytokine and chemokine concentrations, heme oxygenase-1 (HO-1), activated caspase-3, and hypoxia-inducible factor 1-α (HIF-1α) expression, nuclear factor-κB (NF-κB) activation, nitrotyrosine formation, purinergic receptor 2X4 (P2XR4) and 2X7 (P2XR7) expression, and histological scoring. CS exposure prior to chest trauma lead to higher pulmonary compliance and lower PaO2 and Horovitz-index, associated with increased tissue IL-18 and blood MCP-1 concentrations, a 2-4-fold higher inflammatory cell infiltration, and more pronounced alveolar membrane thickening. This effect coincided with increased activated caspase-3, nitrotyrosine, P2XR4, and P2XR7 expression, NF-κB activation, and reduced HIF-1α expression. Hyperoxia did not further affect lung mechanics, gas exchange, pulmonary and systemic cytokine and chemokine concentrations, or histological scoring, except for some patchy alveolar edema in CS exposed mice. However, hyperoxia attenuated tissue HIF-1α, nitrotyrosine, P2XR7, and P2XR4 expression, while it increased HO-1 formation in CS exposed mice. Overall, CS exposure aggravated post

  5. Blunt Chest Trauma in Mice after Cigarette Smoke-Exposure: Effects of Mechanical Ventilation with 100% O2.

    Directory of Open Access Journals (Sweden)

    Katja Wagner

    Full Text Available Cigarette smoking (CS aggravates post-traumatic acute lung injury and increases ventilator-induced lung injury due to more severe tissue inflammation and apoptosis. Hyper-inflammation after chest trauma is due to the physical damage, the drop in alveolar PO2, and the consecutive hypoxemia and tissue hypoxia. Therefore, we tested the hypotheses that 1 CS exposure prior to blunt chest trauma causes more severe post-traumatic inflammation and thereby aggravates lung injury, and that 2 hyperoxia may attenuate this effect. Immediately after blast wave-induced blunt chest trauma, mice (n=32 with or without 3-4 weeks of CS exposure underwent 4 hours of pressure-controlled, thoraco-pulmonary compliance-titrated, lung-protective mechanical ventilation with air or 100% O2. Hemodynamics, lung mechanics, gas exchange, and acid-base status were measured together with blood and tissue cytokine and chemokine concentrations, heme oxygenase-1 (HO-1, activated caspase-3, and hypoxia-inducible factor 1-α (HIF-1α expression, nuclear factor-κB (NF-κB activation, nitrotyrosine formation, purinergic receptor 2X4 (P2XR4 and 2X7 (P2XR7 expression, and histological scoring. CS exposure prior to chest trauma lead to higher pulmonary compliance and lower PaO2 and Horovitz-index, associated with increased tissue IL-18 and blood MCP-1 concentrations, a 2-4-fold higher inflammatory cell infiltration, and more pronounced alveolar membrane thickening. This effect coincided with increased activated caspase-3, nitrotyrosine, P2XR4, and P2XR7 expression, NF-κB activation, and reduced HIF-1α expression. Hyperoxia did not further affect lung mechanics, gas exchange, pulmonary and systemic cytokine and chemokine concentrations, or histological scoring, except for some patchy alveolar edema in CS exposed mice. However, hyperoxia attenuated tissue HIF-1α, nitrotyrosine, P2XR7, and P2XR4 expression, while it increased HO-1 formation in CS exposed mice. Overall, CS exposure

  6. Development of Streamwise Counter-Rotating Vortices in Flat Plate Boundary Layer Pre-set by Leading Edge Patterns

    KAUST Repository

    Hasheminejad, S.M.

    2017-04-03

    Development of streamwise counter-rotating vortices induced by leading edge patterns with different pattern shape is investigated using hot-wire anemometry in the boundary layer of a flat plate. A triangular, sinusoidal and notched patterns with the same pattern wavelength λ of 15mm and the same pattern amplitude A of 7.5mm were examined for free-stream velocity of 3m/s. The results show a good agreement with earlier studies. The inflection point on the velocity profile downstream of the trough of the patterns at the beginning of the vortex formation indicates that the vortices non-linearly propagate downstream. An additional vortex structure was also observed between the troughs of the notched pattern.

  7. Open source and healthcare in Europe - time to put leading edge ideas into practice.

    Science.gov (United States)

    Murray, Peter J; Wright, Graham; Karopka, Thomas; Betts, Helen; Orel, Andrej

    2009-01-01

    Free/Libre and Open Source Software (FLOSS) is a process of software development, a method of licensing and a philosophy. Although FLOSS plays a significant role in several market areas, the impact in the health care arena is still limited. FLOSS is promoted as one of the most effective means for overcoming fragmentation in the health care sector and providing a basis for more efficient, timely and cost effective health care provision. The 2008 European Federation for Medical Informatics (EFMI) Special Topic Conference (STC) explored a range of current and future issues related to FLOSS in healthcare (FLOSS-HC). In particular, there was a focus on health records, ubiquitous computing, knowledge sharing, and current and future applications. Discussions resulted in a list of main barriers and challenges for use of FLOSS-HC. Based on the outputs of this event, the 2004 Open Steps events and subsequent workshops at OSEHC2009 and Med-e-Tel 2009, a four-step strategy has been proposed for FLOSS-HC: 1) a FLOSS-HC inventory; 2) a FLOSS-HC collaboration platform, use case database and knowledge base; 3) a worldwide FLOSS-HC network; and 4) FLOSS-HC dissemination activities. The workshop will further refine this strategy and elaborate avenues for FLOSS-HC from scientific, business and end-user perspectives. To gain acceptance by different stakeholders in the health care industry, different activities have to be conducted in collaboration. The workshop will focus on the scientific challenges in developing methodologies and criteria to support FLOSS-HC in becoming a viable alternative to commercial and proprietary software development and deployment.

  8. The role of the leading edge vortex in lift augmentation of steadily revolving wings: a change in perspective.

    Science.gov (United States)

    Nabawy, Mostafa R A; Crowther, William J

    2017-07-01

    The presence of a stable leading edge vortex (LEV) on steadily revolving wings increases the maximum lift coefficient that can be generated from the wing and its role is important to understanding natural flyers and flapping wing vehicles. In this paper, the role of LEV in lift augmentation is discussed under two hypotheses referred to as 'additional lift' and 'absence of stall'. The 'additional lift' hypothesis represents the traditional view. It presumes that an additional suction/circulation from the LEV increases the lift above that of a potential flow solution. This behaviour may be represented through either the 'Polhamus leading edge suction' model or the so-called 'trapped vortex' model. The 'absence of stall' hypothesis is a more recent contender that presumes that the LEV prevents stall at high angles of attack where flow separation would normally occur. This behaviour is represented through the so-called 'normal force' model. We show that all three models can be written in the form of the same potential flow kernel with modifiers to account for the presence of a LEV. The modelling is built on previous work on quasi-steady models for hovering wings such that model parameters are determined from first principles, which allows a fair comparison between the models themselves, and the models and experimental data. We show that the two models which directly include the LEV as a lift generating component are built on a physical picture that does not represent the available experimental data. The simpler 'normal force' model, which does not explicitly model the LEV, performs best against data in the literature. We conclude that under steady conditions the LEV as an 'absence of stall' model/mechanism is the most satisfying explanation for observed aerodynamic behaviour. © 2017 The Author(s).

  9. Simple X-ray versus ultrasonography examination in blunt chest trauma: effective tools of accurate diagnosis and considerations for rib fractures

    OpenAIRE

    Hwang, Eun Gu; Lee, Yunjung

    2016-01-01

    Simple radiography is the best diagnostic tool for rib fractures caused by chest trauma, but it has some limitations. Thus, other tools are also being used. The aims of this study were to investigate the effectiveness of ultrasonography (US) for identifying rib fractures and to identify influencing factors of its effectiveness. Between October 2003 and August 2007, 201 patients with blunt chest trauma were available to undergo chest radiographic and US examinations for diagnosis of rib fractu...

  10. Blunt gastric injuries.

    Science.gov (United States)

    Oncel, Didem; Malinoski, Darren; Brown, Carlos; Demetriades, Demetrios; Salim, Ali

    2007-09-01

    Gastric rupture after blunt abdominal trauma is a rare injury with few reports in the literature. The purpose of this study was to review our experience with blunt gastric injuries and compare outcomes with small bowel or colon injuries. All patients with hollow viscus perforations after blunt abdominal trauma from 1992 to 2005 at our level I trauma center were reviewed. Of 35,033 blunt trauma admissions, there were 268 (0.7%) patients with a total of 319 perforating hollow viscus injuries, 25 (0.07%) of which were blunt gastric injuries. When compared with the small bowel or colon injuries, the blunt gastric injury group had a higher Injury Severity Score (22 versus 17, P = 0.04), more patients with a chest Abbreviated Injury Score greater than 2 (36% versus 12%, P < 0.01), and a shorter interval from injury to laparotomy (221 versus 366 minutes, P = 0.017). Multivariate analysis identified five independent risk factors for mortality: age older than 55 years, head Abbreviated Injury Score greater than 2, chest Abbreviated Injury Score greater than 2, the presence of hypotension on admission, and Glasgow Coma Scale 8 or less. The results of this study suggest that mortality in patients with blunt hollow viscus injuries can be attributed to concurrent head and chest injuries, but not the specific hollow viscus organ that is injured.

  11. CX3CR1 deficiency alters hippocampal-dependent plasticity phenomena blunting the effects of enriched environment

    Directory of Open Access Journals (Sweden)

    Laura eMaggi

    2011-10-01

    Full Text Available In recent years several evidence demonstrated that some features of hippocampal biology, like neurogenesis, synaptic transmission, learning and memory performances are deeply modulated by social, motor and sensorial experiences. Fractalkine/CX3CL1 is a transmembrane chemokine abundantly expressed in the brain by neurons, where it modulates glutamatergic transmission and long-term plasticity processes regulating the intercellular communication between glia and neurons, being its specific receptor CX3CR1 expressed by microglia. In this paper we investigated the role of CX3CL1/CX3CR1 signaling on experience-dependent hippocampal plasticity processes. At this aim wt and CX3CR1GFP/GFP mice were exposed to long-lasting-enriched environment (EE and the effects on hippocampal functions were studied by electrophysiological recordings of long-term potentiation (LTP of synaptic activity, behavioral tests of learning and memory in the Morris water maze paradigm and analysis of neurogenesis in the subgranular zone of the dentate gyrus (DG.We found that CX3CR1 deficiency increases hippocampal plasticity and spatial memory blunting the potentiating effects of EE. In contrast, exposure to EE increased the number and migration of neural progenitors in the DG of both wt and CX3CR1GFP/GFP mice. These data indicate that CX3CL1/CX3CR1-mediated signaling is crucial for a normal experience-dependent modulation of hippocampal functions.

  12. Comparative Effectiveness of Emergency Resuscitative Thoracotomy versus Closed Chest Compressions among Patients with Critical Blunt Trauma: A Nationwide Cohort Study in Japan.

    Science.gov (United States)

    Suzuki, Kodai; Inoue, Shigeaki; Morita, Seiji; Watanabe, Nobuo; Shintani, Ayumi; Inokuchi, Sadaki; Ogura, Shinji

    2016-01-01

    Although emergency resuscitative thoracotomy is performed as a salvage maneuver for critical blunt trauma patients, evidence supporting superior effectiveness of emergency resuscitative thoracotomy compared to conventional closed-chest compressions remains insufficient. The objective of this study was to investigate whether emergency resuscitative thoracotomy at the emergency department or in the operating room was associated with favourable outcomes after blunt trauma and to compare its effectiveness with that of closed-chest compressions. This was a retrospective nationwide cohort study. Data were obtained from the Japan Trauma Data Bank for the period between 2004 and 2012. The primary and secondary outcomes were patient survival rates 24 h and 28 d after emergency department arrival. Statistical analyses were performed using multivariable generalized mixed-effects regression analysis. We adjusted for the effects of different hospitals by introducing random intercepts in regression analysis to account for the differential quality of emergency resuscitative thoracotomy at hospitals where patients in cardiac arrest were treated. Sensitivity analyses were performed using propensity score matching. In total, 1,377 consecutive, critical blunt trauma patients who received cardiopulmonary resuscitation in the emergency department or operating room were included in the study. Of these patients, 484 (35.1%) underwent emergency resuscitative thoracotomy and 893 (64.9%) received closed-chest compressions. Compared to closed-chest compressions, emergency resuscitative thoracotomy was associated with lower survival rate 24 h after emergency department arrival (4.5% vs. 17.5%, respectively, P chest compressions (P chest compressions.

  13. Blunted cortisol response to acute pre-learning stress prevents misinformation effect in a forced confabulation paradigm.

    Science.gov (United States)

    Zoladz, Phillip R; Cadle, Chelsea E; Dailey, Alison M; Fiely, Miranda K; Peters, David M; Nagle, Hannah E; Mosley, Brianne E; Scharf, Amanda R; Brown, Callie M; Duffy, Tessa J; Earley, McKenna B; Rorabaugh, Boyd R; Payment, Kristie E

    2017-07-01

    Research examining the effects of stress on false memory formation has been equivocal, partly because of the complex nature of stress-memory interactions. A major factor influencing stress effects on learning is the timing of stress relative to encoding. Previous work has shown that brief stressors administered immediately before learning enhance long-term memory. Thus, we predicted that brief stress immediately before learning would decrease participants' susceptibility to subsequent misinformation and reduce false memory formation. Eighty-four male and female participants submerged their hand in ice cold (stress) or warm (no stress) water for 3min. Immediately afterwards, they viewed an 8-min excerpt from the Disney movie Looking for Miracles. The next day, participants were interviewed and asked several questions about the video, some of which forced them to confabulate responses. Three days and three weeks later, respectively, participants completed a recognition test in the lab and a free recall test via email. Our results revealed a robust misinformation effect, overall, as participants falsely recognized a significant amount of information that they had confabulated during the interview as having occurred in the original video. Stress, overall, did not significantly influence this misinformation effect. However, the misinformation effect was completely absent in stressed participants who exhibited a blunted cortisol response to the stress, for both recognition and recall tests. The complete absence of a misinformation effect in non-responders may lend insight into the interactive roles of autonomic arousal and corticosteroid levels in false memory development. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Investigation of a Novel Turbulence Model and Using Leading-Edge Slots for Improving the Aerodynamic Performance of Airfoils and Wind Turbines

    Science.gov (United States)

    Beyhaghi, Saman

    as compared to the baseline DES. In the second part of this study, the focus is on improving the aerodynamic performance of airfoils and wind turbines in terms of lift and drag coefficients and power generation. One special type of add-on feature for wind turbines and airfoils, i.e., leading-edge slots are investigated through numerical simulation and laboratory experiments. Although similar slots are designed and employed for aircrafts, a special slot with a reversed flow direction is drilled in the leading edge of a sample wind turbine airfoil to study its influence on the aerodynamic performance. The objective is to vary the five main geometrical parameters of slot and characterize the performance improvement of the new design under different operating conditions. A number of Design of Experiment and optimization studies are conducted to determine the most suitable slot configuration to maximize the lift or lift-over-drag ratio. Results indicate that proper sizing and placement of slot can improve the lift coefficient, while it has negligible negative impact on the drag. Some recommendations for future investigation on slot are proposed at the end. The performance of a horizontal axis wind turbine blade equipped with leading-edge slot is also studied, and it is concluded that slotted blades can generate about 10% more power than solid blades, for the two operating conditions investigated. The good agreement between the CFD predictions and experimental data confirms the validity of the model and results.

  15. A leading-edge hardware family for diagnostics applications and low-level RF in CERN's ELENA ring

    CERN Document Server

    Angoletta, M E; Jaussi, M; Leiononen, P; Levens, T E; Molendijk, J C; Sanchez-Quesada, J; Simonin, J

    2013-01-01

    The CERN Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons transferred from the CERN’s Antiproton Decelerator (AD). The requirements for the acquisition and treatment of signals for longitudinal diagnostics are very demanding, owing to the revolution frequency swing as well as to the digital signal processing required. The requirements for the Low-Level Radio-Frequency (LLRF) system are very demanding as well, especially in terms of revolution frequency swing, dynamic range and low noise required by the cavity voltage control and digital signal processing to be performed. Both sets of requirements will be satisfied by using a leading-edge hardware family, developed to cover the LLRF needs of all synchrotrons in the Meyrin site; it will be first deployed in 2014 in the CERN’s PSB and in the medical machine MedAustron. This paper gives an overview of the main building blocks of the hardware family and of th...

  16. Leading edge vortices in lesser long-nosed bats occurring at slow but not fast flight speeds

    International Nuclear Information System (INIS)

    Muijres, Florian T; Christoffer Johansson, L; Hedenström, Anders; Winter, York

    2014-01-01

    Slow and hovering animal flight creates high demands on the lift production of animal wings. Steady state aerodynamics is unable to explain the forces required and the most commonly used mechanism to enhance the lift production is a leading edge vortex (LEV). Although LEVs increase the lift, they come at the cost of high drag. Here we determine the flow above the wing of lesser long-nosed bats at slow and cruising speed using particle image velocimetry (PIV). We find that a prominent LEV is present during the downstroke at slow speed, but not at cruising speed. Comparison with previously published LEV data from a robotic flapper inspired by lesser long-nosed bats suggests that bats should be able to generate LEVs at cruising speeds, but that they avoid doing so, probably to increase flight efficiency. In addition, at slow flight speeds we find LEVs of opposite spin at the inner and outer wing during the upstroke, potentially providing a control challenge to the animal. We also note that the LEV stays attached to the wing throughout the downstoke and does not show the complex structures found in insects. This suggests that bats are able to control the development of the LEV and potential control mechanisms are discussed. (papers)

  17. Partners in Science: A Model Cooperative Program Introducing High School Teachers and Students to Leading-Edge Pharmaceutical Science

    Science.gov (United States)

    Woska, Joseph R., Jr.; Collins, Danielle M.; Canney, Brian J.; Arcario, Erin L.; Reilly, Patricia L.

    2005-12-01

    Partners in Science is a cooperative program between Boehringer Ingelheim Pharmaceuticals, Inc. and area high schools in the community surrounding our Connecticut campus. It is a two-phase program that introduces high school students and teachers to the world of drug discovery and leading-edge pharmaceutical research. Phase 1 involves a series of lectures, tours, and demonstrations given by scientists within our research and development division (R&D). Phase 2 involves the selection of a small group of participants to intern for the summer in a research laboratory, working side by side with a scientist within R&D. In this manuscript, the specific aims, goals, and development of the Partners in Science program are described, as well as the syllabus/agenda, the logistics surrounding the operation of the program, and our shared personal experiences with students and teachers who have participated. Some of the pitfalls/problems associated with the program will be presented, and finally, the future direction of the program including areas of improvement and expansion are described.

  18. Forewings match the formation of leading-edge vortices and dominate aerodynamic force production in revolving insect wings.

    Science.gov (United States)

    Chen, Di; Kolomenskiy, Dmitry; Nakata, Toshiyuki; Liu, Hao

    2017-10-20

    In many flying insects, forewings and hindwings are coupled mechanically to achieve flapping flight synchronously while being driven by action of the forewings. How the forewings and hindwings as well as their morphologies contribute to aerodynamic force production and flight control remains unclear yet. Here we demonstrate that the forewings can produce most of the aerodynamic forces even with the hindwings removed through a computational fluid dynamic study of three revolving insect wing models, which are identical to the wing morphologies and Reynolds numbers of hawkmoth (Manduca sexta), bumblebee (Bombus ignitus) and fruitfly (Drosophila melanogaster). We find that the forewing morphologies match the formation of leading-edge vortices (LEV) and are responsible for generating sufficient lift forces at the mean angles of attack and the Reynolds numbers where the three representative insects fly. The LEV formation and pressure loading keep almost unchanged with the hindwing removed, and even lead to some improvement in power factor and aerodynamic efficiency. Moreover, our results indicate that the size and strength of the LEVs can be well quantified with introduction of a conical LEV angle, which varies remarkably with angles of attack and Reynolds numbers but within the forewing region while showing less sensitivity to the wing morphologies. This implies that the forewing morphology very likely plays a dominant role in achieving low-Reynolds number aerodynamic performance in natural flyers as well as in revolving and/or flapping micro air vehicles. © 2017 IOP Publishing Ltd.

  19. Do rapid 'superbug' tests pay off? Balance the costs and benefits of leading-edge technology. Interview by Alan Joch.

    Science.gov (United States)

    Morgan, Margie Ann

    2009-02-01

    As hospitals become increasingly sensitive to the health and financial consequences of health care-associated infections (HAIs), a new generation of molecular-based testing technologies promises to significantly shorten the time required to identify "superbugs" and other bacterial infections. The leading-edge techniques promise to reduce costs by helping hospitals quickly determine which patients to isolate because they carry active methicillin-resistant Staphylococcus aureus (MRSA) infections, for example, or which ones to release from prophylactic isolation because they ultimately tested negative for a dangerous infection. But diagnostic speed comes at a price--the costs to perform molecular tests are significantly higher than conventional methods. This challenges hospitals to balance health care expenses with medical efficacy, says molecular testing veteran Margie Morgan, Ph.D., scientific director at Cedars-Sinai Medical Center, Los Angeles. "The rapid methods can be extreme time savers and possibly help a great deal with the isolation of patients. But some of the tests may cost five times what manual methods might be, so there is a price for seeing so much of a reduction in time," she says.

  20. Transition over C4 leading edge and measurement of intermittency factor using PDF of hot-wire signal

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, B.K.; Hirsch, C. [Vrije Univ. Brussel, Brussels (Belgium). Dept. of Fluid Mechanics

    1997-07-01

    The variation of intermittency factors in the transition region of a C4 leading edge flat plate is measured at three incidence angles in a low-turbulence free stream. During the determination of intermittency factor, the threshold value of the detector function and the validity of conditional averaging are verified by a method based on the direct application of PDF of the hot-wire output. As the angle of incidence is increased, the transition progressively moves through all the three modes on the suction surface: at zero incidence the bypass transition, at 2 deg incidence the natural transition, and at 4 deg incidence the separated-flow transition occur, respectively. All three modes of transition exhibited the chordwise intermittency factor variation in accordance with Narasinha`s universal intermittency distribution; thus, the method based on spot production rate is applicable to all the three modes of transition. In the transition zone of the attached boundary layers, the conditionally averaged interturbulent profiles are fuller than the Blasius profile, while the conditionally averaged turbulent profiles follow a logarithmic profile with a variable additive parameter.

  1. Experimental Observations on the Deformation and Breakup of Water Droplets Near the Leading Edge of an Airfoil

    Science.gov (United States)

    Vargas, Mario; Feo, Alex

    2011-01-01

    This work presents the results of an experimental study on droplet deformation and breakup near the leading edge of an airfoil. The experiment was conducted in the rotating rig test cell at the Instituto Nacional de Tecnica Aeroespacial (INTA) in Madrid, Spain. An airfoil model placed at the end of the rotating arm was moved at speeds of 50 to 90 m/sec. A monosize droplet generator was employed to produce droplets that were allowed to fall from above, perpendicular to the path of the airfoil at a given location. High speed imaging was employed to observe the interaction between the droplets and the airfoil. The high speed imaging allowed observation of droplet deformation and breakup as the droplet approached the airfoil near the stagnation line. A tracking software program was used to measure from the high speed movies the horizontal and vertical displacement of the droplet against time. The velocity, acceleration, Weber number, Bond number, Reynolds number, and the drag coefficients were calculated along the path of a given droplet from beginning of deformation to breakup and/or hitting the airfoil. Results are presented for droplets with a diameter of 490 micrometers at airfoil speeds of 50, 60, 70, 80 and 90 m/sec

  2. A combination of methylprednisolone and quercetin is effective for the treatment of cardiac contusion following blunt chest trauma in rats

    Energy Technology Data Exchange (ETDEWEB)

    Demir, F. [Department of Pediatric Cardiology, Faculty of Medicine, Dicle University, Diyarbakır (Turkey); Güzel, A. [Department of Pediatrics, Faculty of Medicine, Ondokuz Mayıs University, Samsun (Turkey); Katı, C. [Department of Emergency Medicine, Faculty of Medicine, Ondokuz Mayıs University, Samsun (Turkey); Karadeniz, C. [Pediatric Cardiology Services, Behçet Uz Children' s Hospital, İzmir (Turkey); Akdemir, U. [Department of Emergency Medicine, Faculty of Medicine, Ondokuz Mayıs University, Samsun (Turkey); Okuyucu, A. [Department of Medical Biochemistry, Faculty of Medicine, Ondokuz Mayıs University, Samsun (Turkey); Gacar, A. [Department of Pathology, Faculty of Veterinary Medicine, Ondokuz Mayıs University, Samsun (Turkey); Özdemir, S. [Department of Pediatrics, Faculty of Medicine, Ondokuz Mayıs University, Samsun (Turkey); Güvenç, T. [Department of Pathology, Faculty of Veterinary Medicine, Ondokuz Mayıs University, Samsun (Turkey)

    2014-08-01

    Cardiac contusion is a potentially fatal complication of blunt chest trauma. The effects of a combination of quercetin and methylprednisolone against trauma-induced cardiac contusion were studied. Thirty-five female Sprague-Dawley rats were divided into five groups (n=7) as follows: sham, cardiac contusion with no therapy, treated with methylprednisolone (30 mg/kg on the first day, and 3 mg/kg on the following days), treated with quercetin (50 mg·kg{sup −1}·day{sup −1}), and treated with a combination of methylprednisolone and quercetin. Serum troponin I (Tn-I) and tumor necrosis factor-alpha (TNF-α) levels and cardiac histopathological findings were evaluated. Tn-I and TNF-α levels were elevated after contusion (P=0.001 and P=0.001). Seven days later, Tn-I and TNF-α levels decreased in the rats treated with methylprednisolone, quercetin, and the combination of methylprednisolone and quercetin compared to the rats without therapy, but a statistical significance was found only with the combination therapy (P=0.001 and P=0.011, respectively). Histopathological degeneration and necrosis scores were statistically lower in the methylprednisolone and quercetin combination group compared to the group treated only with methylprednisolone (P=0.017 and P=0.007, respectively). However, only degeneration scores were lower in the combination therapy group compared to the group treated only with quercetin (P=0.017). Inducible nitric oxide synthase positivity scores were decreased in all treatment groups compared to the untreated groups (P=0.097, P=0.026, and P=0.004, respectively). We conclude that a combination of quercetin and methylprednisolone can be used for the specific treatment of cardiac contusion.

  3. Mesh sensitivity effects on fatigue crack growth by crack-tip blunting and re-sharpening

    DEFF Research Database (Denmark)

    Tvergaard, Viggo

    2007-01-01

    remeshing at several stages of the plastic deformation, with studies of the effect of overloads or compressive underloads. Recent published analyses for the first two cycles have shown folding of the crack surface in compression, leading to something that looks like striations. The influence of mesh...... refinement is used to study the possibility of this type of behaviour within the present method. Even with much refined meshes no indication of crack surface folding is found here....

  4. Association between white-coat effect and blunted dipping of nocturnal blood pressure.

    Science.gov (United States)

    Bochud, Murielle; Bovet, Pascal; Vollenweider, Peter; Maillard, Marc; Paccaud, Fred; Wandeler, Gilles; Gabriel, Anne; Burnier, Michel

    2009-10-01

    In this study, we assessed whether the white-coat effect (difference between office and daytime blood pressure (BP)) is associated with nondipping (absence of BP decrease at night). Data were available in 371 individuals of African descent from 74 families selected from a population-based hypertension register in the Seychelles Islands and in 295 Caucasian individuals randomly selected from a population-based study in Switzerland. We used standard multiple linear regression in the Swiss data and generalized estimating equations to account for familial correlations in the Seychelles data. The prevalence of systolic and diastolic nondipping (rate was inversely associated with the difference between daytime and night-time heart rate in the two populations. These results did not change after adjustment for potential confounders. The white-coat effect is associated with BP nondipping. The similar associations between office-daytime values and daytime-night-time values for both BP and heart rate suggest that the sympathetic nervous system might play a role. Our findings also further stress the interest, for clinicians, of assessing the presence of a white-coat effect as a means to further identify patients at increased cardiovascular risk and guide treatment accordingly.

  5. Directional migration of leading-edge mesoderm generates physical forces: Implication in Xenopus notochord formation during gastrulation.

    Science.gov (United States)

    Hara, Yusuke; Nagayama, Kazuaki; Yamamoto, Takamasa S; Matsumoto, Takeo; Suzuki, Makoto; Ueno, Naoto

    2013-10-15

    Gastrulation is a dynamic tissue-remodeling process occurring during early development and fundamental to the later organogenesis. It involves both chemical signals and physical factors. Although much is known about the molecular pathways involved, the roles of physical forces in regulating cellular behavior and tissue remodeling during gastrulation have just begun to be explored. Here, we characterized the force generated by the leading edge mesoderm (LEM) that migrates preceding axial mesoderm (AM), and investigated the contribution of LEM during Xenopus gastrulation. First, we constructed an assay system using micro-needle which could measure physical forces generated by the anterior migration of LEM, and estimated the absolute magnitude of the force to be 20-80nN. Second, laser ablation experiments showed that LEM could affect the force distribution in the AM (i.e. LEM adds stretch force on axial mesoderm along anterior-posterior axis). Third, migrating LEM was found to be necessary for the proper gastrulation cell movements and the establishment of organized notochord structure; a reduction of LEM migratory activity resulted in the disruption of mediolateral cell orientation and convergence in AM. Finally, we found that LEM migration cooperates with Wnt/PCP to form proper notochord. These results suggest that the force generated by the directional migration of LEM is transmitted to AM and assists the tissue organization of notochord in vivo independently of the regulation by Wnt/PCP. We propose that the LEM may have a mechanical role in aiding the AM elongation through the rearrangement of force distribution in the dorsal marginal zone. © 2013 Elsevier Inc. All rights reserved.

  6. The Lived Experiences of Leading Edge Certified Elementary School Teachers Who Use Instructional Technology to Foster Critical Thinking, Collaboration, Creativity, and Communication in Their Classrooms: A Phenomenological Study

    Science.gov (United States)

    Ruddell, Natalie

    2017-01-01

    Purpose: The purpose of this phenomenological study was to describe the perceptions of current and former Leading Edge Certified (LEC) elementary school teachers regarding instructional technology practices that facilitate students' development of critical thinking, collaboration, communication, and creativity (4Cs) in one-to-one computer…

  7. Swords with Blunt Edges

    Science.gov (United States)

    Popham, W. James

    2004-01-01

    Many U.S. educators now wonder whether they're teachers or targets. This mentality stems from the specter of their school being sanctioned for failing the state accountability tests mandated under No Child Left Behind (NCLB). According to this author, most of those tests are like blunt-edged swords: They function badly in two directions. While…

  8. Blunt traumatic diaphragmatic rupture

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Nogueira

    2011-09-01

    Full Text Available Traumatic injury of the diaphragm ranges from 0.6 to 1.2% and rise up to 5%among patients who were victims of blunt trauma and underwent laparotomy.Clinical suspicion associated with radiological assessment contributes to earlydiagnosis. Isolated diaphragmatic injury has a good prognosis. Generallyworse outcomes are associated with other trauma injuries. Bilateral andright diaphragmatic lesions have worse prognosis. Multi detector computed tomography (MDCT scan of the chest and abdomen provides better diagnosticaccuracy using the possibility of image multiplanar reconstruction. Surgicalrepair via laparotomy and/ or thoracotomy in the acute phase of the injury hasa better outcome and avoids chronic complications of diaphragmatic hernia.The authors present the case of a young male patient, victim of blunt abdominaltrauma due to motor vehicle accident with rupture of the diaphragm, spleenand kidney injuries. The diagnosis was made by computed tomography of thethorax and abdomen and was confirmed during laparotomy.

  9. Pathophysiological effects and changes in potassium, ionised calcium, glucose and haemoglobin early after severe blunt chest trauma.

    Science.gov (United States)

    Rocksén, David; Gryth, Dan; Druid, Henrik; Gustavsson, Jenny; Arborelius, Ulf P

    2012-05-01

    Severe lung contusion is often observed after blunt chest trauma due to traffic accidents or fall from heights, but may also occur after a non-penetrating ballistic impact against body armour. Such trauma has been designated behind armour blunt trauma (BABT). Our aim in the present study has been to evaluate pathophysiological changes and compensatory mechanisms that occur early after such severe lung contusion. Twelve pigs wearing body armour were shot with a 7.62mm assault rifle to produce a standardised pulmonary contusion. Exposed animals were compared with five control animals shot with blank ammunition. Physiological parameters and levels of potassium, glucose, haemoglobin, calcium, lactate and pH were monitored for two hours after the shot. The impact induced severe pulmonary contusion with apnoea, desaturation and hypotension in all exposed animals. Increased haemoglobin, glucose and severe hyperkalaemia were seen shortly after impact. Seven of twelve animals died due to the trauma. Dense cardiac tissue was observed during post mortem examination in six of the animals that died during the experimental course. In conclusion, this study has shown that life-threatening hyperkalaemia occurs early after severe lung contusion. Moreover, dense cardiac tissue and early increase of haemoglobin and glucose are intriguing findings that should be investigated in future studies. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Blunt chest trauma.

    Science.gov (United States)

    Stewart, Daphne J

    2014-01-01

    Blunt chest trauma is associated with a wide range of injuries, many of which are life threatening. This article is a case study demonstrating a variety of traumatic chest injuries, including pathophysiology, diagnosis, and treatment. Literature on the diagnosis and treatment was reviewed, including both theoretical and research literature, from a variety of disciplines. The role of the advance practice nurse in trauma is also discussed as it relates to assessment, diagnosis, and treatment of patients with traumatic chest injuries.

  11. Suppression of chemotaxis by SSeCKS via scaffolding of phosphoinositol phosphates and the recruitment of the Cdc42 GEF, Frabin, to the leading edge.

    Science.gov (United States)

    Ko, Hyun-Kyung; Guo, Li-wu; Su, Bing; Gao, Lingqiu; Gelman, Irwin H

    2014-01-01

    Chemotaxis is controlled by interactions between receptors, Rho-family GTPases, phosphatidylinositol 3-kinases, and cytoskeleton remodeling proteins. We investigated how the metastasis suppressor, SSeCKS, attenuates chemotaxis. Chemotaxis activity inversely correlated with SSeCKS levels in mouse embryo fibroblasts (MEF), DU145 and MDA-MB-231 cancer cells. SSeCKS loss induced chemotactic velocity and linear directionality, correlating with replacement of leading edge lamellipodia with fascin-enriched filopodia-like extensions, the formation of thickened longitudinal F-actin stress fibers reaching to filopodial tips, relative enrichments at the leading edge of phosphatidylinositol (3,4,5)P3 (PIP3), Akt, PKC-ζ, Cdc42-GTP and active Src (SrcpoY416), and a loss of Rac1. Leading edge lamellipodia and chemotaxis inhibition in SSeCKS-null MEF could be restored by full-length SSeCKS or SSeCKS deleted of its Src-binding domain (ΔSrc), but not by SSeCKS deleted of its three MARCKS (myristylated alanine-rich C kinase substrate) polybasic domains (ΔPBD), which bind PIP2 and PIP3. The enrichment of activated Cdc42 in SSeCKS-null leading edge filopodia correlated with recruitment of the Cdc42-specific guanine nucleotide exchange factor, Frabin, likely recruited via multiple PIP2/3-binding domains. Frabin knockdown in SSeCKS-null MEF restores leading edge lamellipodia and chemotaxis inhibition. However, SSeCKS failed to co-immunoprecipitate with Rac1, Cdc42 or Frabin. Consistent with the notion that chemotaxis is controlled by SSeCKS-PIP (vs. -Src) scaffolding activity, constitutively-active phosphatidylinositol 3-kinase could override the ability of the Src inhibitor, SKI-606, to suppress chemotaxis and filopodial enrichment of Frabin in SSeCKS-null MEF. Our data suggest a role for SSeCKS in controlling Rac1 vs. Cdc42-induced cellular dynamics at the leading chemotactic edge through the scaffolding of phospholipids and signal mediators, and through the reorganization of the

  12. Comparative Effectiveness of Emergency Resuscitative Thoracotomy versus Closed Chest Compressions among Patients with Critical Blunt Trauma: A Nationwide Cohort Study in Japan.

    Directory of Open Access Journals (Sweden)

    Kodai Suzuki

    Full Text Available Although emergency resuscitative thoracotomy is performed as a salvage maneuver for critical blunt trauma patients, evidence supporting superior effectiveness of emergency resuscitative thoracotomy compared to conventional closed-chest compressions remains insufficient. The objective of this study was to investigate whether emergency resuscitative thoracotomy at the emergency department or in the operating room was associated with favourable outcomes after blunt trauma and to compare its effectiveness with that of closed-chest compressions.This was a retrospective nationwide cohort study. Data were obtained from the Japan Trauma Data Bank for the period between 2004 and 2012. The primary and secondary outcomes were patient survival rates 24 h and 28 d after emergency department arrival. Statistical analyses were performed using multivariable generalized mixed-effects regression analysis. We adjusted for the effects of different hospitals by introducing random intercepts in regression analysis to account for the differential quality of emergency resuscitative thoracotomy at hospitals where patients in cardiac arrest were treated. Sensitivity analyses were performed using propensity score matching.In total, 1,377 consecutive, critical blunt trauma patients who received cardiopulmonary resuscitation in the emergency department or operating room were included in the study. Of these patients, 484 (35.1% underwent emergency resuscitative thoracotomy and 893 (64.9% received closed-chest compressions. Compared to closed-chest compressions, emergency resuscitative thoracotomy was associated with lower survival rate 24 h after emergency department arrival (4.5% vs. 17.5%, respectively, P < 0.001 and 28 d after arrival (1.2% vs. 6.0%, respectively, P < 0.001. Multivariable generalized mixed-effects regression analysis with and without a propensity score-matched dataset revealed that the odds ratio for an unfavorable survival rate after 24 h was lower for

  13. Myosin II activity is required for functional leading-edge cells and closure of epidermal sheets in fish skin ex vivo.

    Science.gov (United States)

    Morita, Toshiyuki; Tsuchiya, Akiko; Sugimoto, Masazumi

    2011-09-01

    Re-epithelialization in skin wound healing is a process in which epidermal sheets grow and close the wound. Although the actin-myosin system is thought to have a pivotal role in re-epithelialization, its role is not clear. In fish skin, re-epithelialization occurs around 500 μm/h and is 50 times faster than in mammalian skin. We had previously reported that leading-edge cells of the epidermal outgrowth have both polarized large lamellipodia and "purse string"-like actin filament cables in the scale-skin culture system of medaka fish, Oryzias latipes (Cell Tissue Res, 2007). The actin purse-string (APS) is a supracellular contractile machinery in which adherens junctions (AJs) link intracellular myosin II-including actin cables between neighboring cells. In this study, we developed a modified "face-to-face" scale-skin culture system as an ex vivo model to study epidermal wound healing, and examined the role of the actin-myosin system in the rapid re-epithelialization using a myosin II ATPase inhibitor, blebbistatin. A low level of blebbistatin suppressed the formation of APS and induced the dissociation of keratocytes from the leading edge without attenuating the growth of the epidermal sheet or the migration rate of solitary keratocytes. AJs in the superficial layer showed no obvious changes elicited by blebbistatin. However, two epidermal sheets without APSs did not make a closure with each other, which was confirmed by inhibiting the connecting AJs between the superficial layers. These results suggest that myosin II activity is required for functional leading-edge cells and for epidermal closure.

  14. Adverse Effects of Antidepressants Reported by 1,431 people from 38 Countries: Emotional Blunting, Suicidality, and Withdrawal Effects.

    Science.gov (United States)

    Read, John; Williams, James

    2018-06-04

    Studies of the adverse effects of antidepressants tend to focus on biological symptoms. The prevalence of suicidality and withdrawal effects are currently a source of controversy. To directly ascertain the experiences of an international sample of antidepressant users. An online survey asked adult antidepressant users whether they had experienced 20 adverse effects 'as a result of taking the antidepressant', and if so, to what degree of severity. 1,431 people from 38 countries responded. 61% of the respondents reported at least ten of the 20 effects, most commonly: 'Feeling emotionally numb' (reported by 71%), 'Feeling foggy or detached' (70%); 'Feeling not like myself' (66%), 'Sexual difficulties' (66%), 'Drowsiness' (63%), and 'Reduction in positive feelings' (60%). 'Suicidality' as a result of the drugs was reported by 50%. Withdrawal effects were reported by 59%, and 'Addiction' by 40%. Rates of adverse effects were higher for those prescribed multiple antidepressants and those who also took antipsychotics. Younger age and longer use of ADs were positively related to total adverse effects. One third did not recall being told about any side effects by the prescriber. Less than 5% were told about suicidality, emotional numbing, withdrawal effects or addiction. Asking people directly reveals far higher rates of adverse responses to antidepressants than previously understood, especially in the emotional, psychological and interpersonal domains. Given recent findings that antidepressants are only marginally more effective than placebo, the findings of the current study imply a cost-benefit analysis that cannot justify the extremely high prescription rates for these drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Effects of dietary fructooligosaccharide levels and feeding modes on growth, immune responses, antioxidant capability and disease resistance of blunt snout bream (Megalobrama amblycephala).

    Science.gov (United States)

    Zhang, Chun-Nuan; Li, Xiang-Fei; Jiang, Guang-Zhen; Zhang, Ding-Dong; Tian, Hong-Yan; Li, Jun-Yi; Liu, Wen-Bin

    2014-12-01

    This study aimed to determine the effects of fructooligosaccharide (FOS) levels and its feeding modes on growth, immune response, antioxidant capability and disease resistance of blunt snout bream (Megalobrama amblycephala). Fish (12.5 ± 0.5 g) were subjected to three FOS levels (0, 0.4% and 0.8%) and two feeding modes (supplementing FOS continuously and supplementing FOS two days interval 5 days) according to a 3 × 2 factorial design. At the end of 8-week feeding trial, fish were challenged by Aeromonas hydrophila with concentration of 1 × 10(5) CFU mL(-1) and mortality was recorded for the next 96 h. Fish fed 0.4% FOS continuously (D2) and fish fed the basal diet for 5 days followed by 0.8% FOS for 2 days (D5) showed admirable growth performance. The highest plasma lysozyme, acid phosphatase and myeloperoxidase activities as well as complement component 3, total protein and immunoglobulin M (IgM) levels were all observed in fish fed D5. They were significantly higher (P 0.05) with that of fish fed D2. A similar trend was also observed in antioxidant capability as well as the expression of Leap-I and Leap-Ⅱ. Mortality showed an opposite trend with the immune response with the lowest rate observed in fish fed D5. The results indicated that diet supplementing FOS in appropriate levels and feeding modes could improve the growth, immune response and antioxidant capability of fish, as might consequently lead to enhanced disease resistance. It can be speculated that the basal diet for 5 days followed by 0.8% FOS for 2 days was most suitable for blunt snout bream. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Analysis of dimensionality effect on shock wave boundary layer interaction in laminar hypersonic flows

    International Nuclear Information System (INIS)

    John, Bibin; Surendranath, Srikanth; Natarajan, Ganesh; Kulkarni, Vinayak

    2016-01-01

    Highlights: • Leading edge bluntness based separation control has been analysed numerically for 2D and axi-symmetric flows. • Differential growth of entropy layer in the streamwise direction in these cases leads to different interaction with respective boundary layers. • Separation control is found possible for planar flows beyond a critical radius called as equivalent radius. • No equivalent radius has been noticed in axi-symmertric flows in the present studies due to thin entropy layer and lack of favourable pressure gradient. - Abstract: Present investigations are centered on passive control of shock wave boundary layer interaction (SWBLI) for double cone and double wedge configurations with leading edge bluntness. This study seeks the differences in the flow physics of SWBLI in case of two dimensional (2D) and axisymmetric flow fields. In-house developed second order accurate finite-volume 2D axisymmetric compressible flow solver is employed for these studies. It is observed that the idea of leading edge bluntness offers reduction in separation bubble for 2D flow fields, whereas it leads to enhanced separation zone in case of axisymmetric flow fields. Relevant flow physics is well explored herein using wall pressure profile and relative thicknesses of boundary layer and entropy layer. Thicker entropy layer and stronger favorable pressure gradient are found responsible for the possibility of separation control in case of 2D flow fields. Thin entropy layer due to three dimensional relieving effect and its swallowing by the boundary layer are attributed for higher separation bubble size in case of cone with range of radii under consideration.

  17. Mass and performance optimization of an airplane wing leading edge structure against bird strike using Taguchi-based grey relational analysis

    Directory of Open Access Journals (Sweden)

    Hassan Pahange

    2016-08-01

    Full Text Available Collisions between birds and aircraft are one of the most dangerous threats to flight safety. In this study, smoothed particles hydrodynamics (SPH method is used for simulating the bird strike to an airplane wing leading edge structure. In order to verify the model, first, experiment of bird strike to a flat aluminum plate is simulated, and then bird impact on an airplane wing leading edge structure is investigated. After that, considering dimensions of wing internal structural components like ribs, skin and spar as design variables, we try to minimize structural mass and wing skin deformation simultaneously. To do this, bird strike simulations to 18 different wing structures are made based on Taguchi’s L18 factorial design of experiment. Then grey relational analysis is used to minimize structural mass and wing skin deformation due to the bird strike. The analysis of variance (ANOVA is also applied and it is concluded that the most significant parameter for the performance of wing structure against impact is the skin thickness. Finally, a validation simulation is conducted under the optimal condition to show the improvement of performance of the wing structure.

  18. Rolling and scrolling: The portrayal of marijuana cigars (blunts) on YouTube.

    Science.gov (United States)

    Montgomery, LaTrice; Yockey, Andrew

    2018-01-01

    Blunts are partially or fully hollowed-out cigars or cigarillos that are filled with marijuana. Despite the high prevalence of blunt use, very few studies assess this specific method of cannabis administration. YouTube, a popular video-sharing website, has the potential to provide insights into blunt use. The purpose of this study was to examine the content of YouTube videos that discuss blunts. A sample of 41 videos was coded for content. The 41 videos had a total of 27,579,636 views. Most of the individuals in the videos were male (85%) and many appeared to be White (80%) and under the age of 25 (46%). Only 34% of the videos had an age restriction. The majority of messages in the videos promoted blunt use (93%) and showed at least one person rolling (76%) and/or smoking (66%) a blunt. The videos mainly consisted of introductions to blunt use (76%) and tips and personal experiences with blunt use (73%). YouTube videos on blunt use are readily available and primarily promote the use of blunts. Future research should continue to monitor YouTube content and develop videos on social media platforms that inform consumers of the health effects associated with blunt use.

  19. Timing of blunt force injuries in long bones: the effects of the environment, PMI length and human surrogate model.

    Science.gov (United States)

    Coelho, Luís; Cardoso, Hugo F V

    2013-12-10

    Timing of blunt force trauma in human bone is a critical forensic issue, but there is limited knowledge on how different environmental conditions, the duration of postmortem interval (PMI), different bone types and different animal models influence fracture morphology. This study aims at evaluating the influence of the type of postmortem environment and the duration of the postmortem period on fracture morphology, for distinguishing perimortem from postmortem fractures on different types of long bones from different species. Fresh limb segments from pig and goat were sequentially left to decompose, under 3 different environmental circumstances (surface, buried and submerged), resulting in sets with different PMI lengths (0, 28, 56, 84, 112, 140, 168 and 196 days), which were then fractured. Fractured bones (total=325; pig tibia=110; pig fibula=110; goat metatarsals=105) were classified according to the Fracture Freshness Index (FFI). Climatic data for the experiment location was collected. Statistical analysis included descriptive statistics, correlation analysis between FFI and PMI, Mann-Whitney U tests comparing FFI medians for different PMI's and linear regression analysis using PMI, pluviosity and temperature as predictors for FFI. Surface samples presented increases in FFI with increasing PMI, with positive correlations for all bone types. The same results were observed in submerged samples, except for pig tibia. Median FFI values for surface samples could distinguish bones with PMI=0 days from PMI≥56 days. Buried samples presented no significant correlation between FFI and PMI, and nonsignificant regression models. Regression analysis of surface and submerged samples suggested differences in FFI variation with PMI between bone types, although without statistical significance. Adding climatic data to surface regression models resulted in PMI no longer predicting FFI. When comparing different animal models, linear regressions suggested greater increases in

  20. Effects of Gabra2 Point Mutations on Alcohol Intake: Increased Binge-Like and Blunted Chronic Drinking by Mice.

    Science.gov (United States)

    Newman, Emily L; Gunner, Georgia; Huynh, Polly; Gachette, Darrel; Moss, Stephen J; Smart, Trevor G; Rudolph, Uwe; DeBold, Joseph F; Miczek, Klaus A

    2016-11-01

    Alcohol use disorders are associated with single-nucleotide polymorphisms in GABRA2, the gene encoding the GABA A receptor α2-subunit in humans. Deficient GABAergic functioning is linked to impulse control disorders, intermittent explosive disorder, and to drug abuse and dependence, yet it remains unclear whether α2-containing GABA A receptor sensitivity to endogenous ligands is involved in excessive alcohol drinking. Male wild-type (Wt) C57BL/6J and point-mutated mice rendered insensitive to GABAergic modulation by benzodiazepines (BZD; H101R), allopregnanolone (ALLO) or tetrahydrodeoxycorticosterone (THDOC; Q241M), or high concentrations of ethanol (EtOH) (S270H/L277A) at α2-containing GABA A receptors were assessed for their binge-like, moderate, or escalated chronic drinking using drinking in the dark, continuous access (CA) and intermittent access (IA) to alcohol protocols, respectively. Social approach by mutant and Wt mice in forced alcohol abstinence was compared to approach by EtOH-naïve controls. Social deficits in forced abstinence were treated with allopregnanolone (0, 3.0, 10.0 mg/kg, intraperitoneal [i.p.]) or midazolam (0, 0.56, 1.0 mg/kg, i.p.). Mice with BZD-insensitive α2-containing GABA A receptors (H101R) escalated their binge-like drinking. Mutants harboring the Q241M point substitution in Gabra2 showed blunted chronic intake in the CA and IA protocols. S270H/L277A mutants consumed excessive amounts of alcohol but, unlike wild-types, they did not show forced abstinence-induced social deficits. These findings suggest a role for: (i) H101 in species-typical binge-like drinking, (ii) Q241 in escalated chronic drinking, and (iii) S270 and/or L277 in the development of forced abstinence-associated social deficits. Clinical findings report reduced BZD-binding sites in the cortex of dependent patients; the present findings suggest a specific role for BZD-sensitive α2-containing receptors. In addition, amino acid residue 241 in Gabra2 is

  1. The effect of small streamwise velocity distortion on the boundary layer flow over a thin flat plate with application to boundary layer stability theory

    Science.gov (United States)

    Goldstein, M. E.; Leib, S. J.; Cowley, S. J.

    1990-01-01

    Researchers show how an initially linear spanwise disturbance in the free stream velocity field is amplified by leading edge bluntness effects and ultimately leads to a small amplitude but linear spanwise motion far downstream from the edge. This spanwise motion is imposed on the boundary layer flow and ultimately causes an order-one change in its profile shape. The modified profiles are highly unstable and can support Tollmein-Schlichting wave growth well upstream of the theoretical lower branch of the neutral stability curve for a Blasius boundary layer.

  2. Effect of a Roughness Element on the Receptivity of a Hypersonic Boundary Layer over a Blunt Cone Due to Pulse Entropy Disturbance with a Single Frequency

    Directory of Open Access Journals (Sweden)

    Zhenqing Wang

    2018-05-01

    Full Text Available A high-order finite difference method was used to simulate the hypersonic flow field over a blunt cone with different height roughness elements. The unsteady flow field induced by pulse disturbances was analyzed and compared with that under continuous disturbances. The temporal and spatial evolution characteristics of disturbances in the boundary layer were investigated and the propagation of different disturbance modes in the boundary layer was researched through the fast Fourier transform (FFT method. The effect of the roughness element on the receptivity characteristic of the hypersonic boundary layer under pulse entropy disturbances was explored. The results showed that the different mode disturbances near roughness in the boundary layer were enlarged in the upstream half of the roughness element and suppressed in the downstream half. However, the effect of roughness weakened gradually as the disturbance frequency increased in the boundary layer. A phenomenon of mode competition in the downstream region of the roughness element exited. As the disturbances propagated downstream, the fundamental mode gradually became the dominant mode. A certain promotion effect on the mode competition was induced by the roughness element and the effect was enhanced with the increase in the roughness element height.

  3. James Blunt matuselaulude edetabeli tipus

    Index Scriptorium Estoniae

    2006-01-01

    Bereavement Registeri andmetel Suurbritannias matustel tellitavate laulude edetabelis: James Blunt "Goodbye My Lover", Robbie Williams "Angels", Jennifer Warnes ja Bill Medley "I've Had the Time Of My Life", Elton John "Candle in the Wind", Righteous Brothers "Unchained Melody"

  4. GASTROINTESTINAL INJURIES FROM BLUNT ABDOMINAL ...

    African Journals Online (AJOL)

    hi-tech

    2004-04-04

    Apr 4, 2004 ... Subjects: Twenty one children managed for gastrointestinal injuries from blunt trauma ... ileus, urinary tract infection and chest infection, respectively postoperatively. .... predictive value with CT scan, (9) the positive predictive.

  5. A RETROSPECTIVE STUDY ON BLUNT INJURY ABDOMEN

    OpenAIRE

    Kopperundevi; Jagadeesan; Kiruthiga

    2016-01-01

    Blunt injury abdomen is the leading cause of morbidity and mortality in all age groups. Blunt trauma differs from penetrating trauma as different organs are characteristically injured by compression from blunt straining. A total of 53 cases of blunt trauma were studied in this study for the period of 1 year. In this study, commonest cause for blunt abdominal trauma was road traffic accident. The maximum incidence was noted in 20-40 middle age group of which 90% male patients were ...

  6. Blunt cerebrovascular injuries in trauma.

    Science.gov (United States)

    Eastham, Shannon

    2016-09-01

    Blunt cerebrovascular injury (BCVI) includes trauma to the carotid or vertebral vessels and is noted in 0.1% of hospitalized trauma patients without an initial screening system in place. Several important topics must be addressed including determination of the appropriate screening population, the best modality of screening for diagnosis, treatment types, and required follow-up of blunt cerebrovascular injuries. Copyright © 2015 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  7. Simple X-ray versus ultrasonography examination in blunt chest trauma: effective tools of accurate diagnosis and considerations for rib fractures.

    Science.gov (United States)

    Hwang, Eun Gu; Lee, Yunjung

    2016-12-01

    Simple radiography is the best diagnostic tool for rib fractures caused by chest trauma, but it has some limitations. Thus, other tools are also being used. The aims of this study were to investigate the effectiveness of ultrasonography (US) for identifying rib fractures and to identify influencing factors of its effectiveness. Between October 2003 and August 2007, 201 patients with blunt chest trauma were available to undergo chest radiographic and US examinations for diagnosis of rib fractures. The two modalities were compared in terms of effectiveness based on simple radiographic readings and US examination results. We also investigated the factors that influenced the effectiveness of US examination. Rib fractures were detected on radiography in 69 patients (34.3%) but not in 132 patients. Rib fractures were diagnosed by using US examination in 160 patients (84.6%). Of the 132 patients who showed no rib fractures on radiography, 92 showed rib fractures on US. Among the 69 patients of rib fracture detected on radiography, 33 had additional rib fractures detected on US. Of the patients, 76 (37.8%) had identical radiographic and US results, and 125 (62.2%) had fractures detected on US that were previously undetected on radiography or additional fractures detected on US. Age, duration until US examination, and fracture location were not significant influencing factors. However, in the group without detected fractures on radiography, US showed a more significant effectiveness than in the group with detected fractures on radiography ( P =0.003). US examination could detect unnoticed rib fractures on simple radiography. US examination is especially more effective in the group without detected fractures on radiography. More attention should be paid to patients with chest trauma who have no detected fractures on radiography.

  8. The effect of pre-injury anti-platelet therapy on the development of complications in isolated blunt chest wall trauma: a retrospective study.

    Directory of Open Access Journals (Sweden)

    Ceri Battle

    Full Text Available INTRODUCTION: The difficulties in the management of the blunt chest wall trauma patient in the Emergency Department due to the development of late complications are well recognised in the literature. Pre-injury anti-platelet therapy has been previously investigated as a risk factor for poor outcomes following traumatic head injury, but not in the blunt chest wall trauma patient cohort. The aim of this study was to investigate pre-injury anti-platelet therapy as a risk factor for the development of complications in the recovery phase following blunt chest wall trauma. METHODS: A retrospective study was completed in which the medical notes were analysed of all blunt chest wall trauma patients presenting to a large trauma centre in Wales in 2012 and 2013. Using univariate and multivariable logistic regression analysis, pre-injury platelet therapy was investigated as a risk factor for the development of complications following blunt chest wall trauma. Previously identified risk factors were included in the analysis to address the influence of confounding. RESULTS: A total of 1303 isolated blunt chest wall trauma patients presented to the ED in Morriston Hospital in 2012 and 2013 with complications recorded in 144 patients (11%. On multi-variable analysis, pre-injury anti-platelet therapy was found to be a significant risk factor for the development of complications following isolated blunt chest wall trauma (odds ratio: 16.9; 95% confidence intervals: 8.2-35.2. As in previous studies patient age, number of rib fractures, chronic lung disease and pre-injury anti-coagulant use were also found to be significant risk factors. CONCLUSIONS: Pre-injury anti-platelet therapy is being increasingly used as a first line treatment for a number of conditions and there is a concurrent increase in trauma in the elderly population. Pre-injury anti-platelet therapy should be considered as a risk factor for the development of complications by clinicians managing

  9. Imaging of blunt chest trauma

    International Nuclear Information System (INIS)

    Prosch, H.; Negrin, L.

    2014-01-01

    Blunt chest trauma is associated with high morbidity and mortality. Consequently, all patients should be evaluated radiologically after blunt chest trauma to allow timely and appropriate treatment. Conventional chest radiographs and computed tomography (CT) are proven modalities with which to evaluate patients after blunt chest trauma. Over the last several years extended focused assessment with sonography for trauma (eFAST) has gained increasing importance for the initial assessment of seriously injured patients. In the acute phase of severely injured patients eFAST examinations are helpful to exclude pneumothorax, hemothorax and hemopericardium. Chest radiographs may also be used to diagnose a pneumothorax or hemothorax; however, the sensitivity is limited and CT is the diagnostic modality of choice to evaluate severely injured patients. (orig.) [de

  10. Cumulative effective radiation dose received by blunt trauma patients arriving to a military level I trauma center from point of injury and interhospital transfers.

    Science.gov (United States)

    Van Arnem, Kerri A; Supinski, David P; Tucker, Jonathan E; Varney, Shawn

    2016-12-01

    Trauma patients sustaining blunt injuries are exposed to multiple radiologic studies. Evidence indicates that the risk of cancer from exposure to ionizing radiation rises in direct proportion to the cumulative effective dose (CED) received. The purpose of this study is to quantify the amount of ionizing radiation accumulated when arriving directly from point of injury to San Antonio Military Medical Center (SAMMC), a level I trauma center, compared with those transferred from other facilities. A retrospective record review was conducted from 1st January 2010 through 31st December 2012. The SAMMC trauma registry, electronic medical records, and the digital radiology imaging system were searched for possible candidates. The medical records were then analyzed for sex, age, mechanism of injury, received directly from point of injury (direct group), transfer from another medical facility (transfer group), computed tomographic scans received, dose-length product, CED of radiation, and injury severity score. A diagnostic imaging physicist then calculated the estimated CED each subject received based on the dose-length product of each computed tomographic scan. A total of 300 patients were analyzed, with 150 patients in the direct group and 150 patients in the transfer group. Both groups were similar in age and sex. Patients in the transfer group received a significantly greater CED of radiation compared with the direct group (mean, 37.6 mSv vs 28 mSv; P=.001). The radiation received in the direct group correlates with a lifetime attributable risk (LAR) of 1 in 357 compared with the transfer group with an increase in LAR to 1 in 266. Patients transferred to our facility received a 34% increase in ionizing radiation compared with patients brought directly from the injury scene. This increased dose of ionizing radiation contributes to the LAR of cancer and needs to be considered before repeating imaging studies. III. Published by Elsevier Inc.

  11. Blunt Head Trauma and Headache

    Directory of Open Access Journals (Sweden)

    Ana B Chelse

    2015-04-01

    Full Text Available Investigators from New York Presbyterian Morgan Stanley Children’s Hospital examined whether having an isolated headache following minor blunt head trauma was suggestive of traumatic brain injury (TBI among a large cohort of children 2-18 years of age.

  12. Probiotics Blunt the Anti-Hypertensive Effect of Blueberry Feeding in Hypertensive Rats without Altering Hippuric Acid Production.

    Science.gov (United States)

    Blanton, Cynthia; He, Zhengcheng; Gottschall-Pass, Katherine T; Sweeney, Marva I

    2015-01-01

    Previously we showed that feeding polyphenol-rich wild blueberries to hypertensive rats lowered systolic blood pressure. Since probiotic bacteria produce bioactive metabolites from berry polyphenols that enhance the health benefits of berry consumption, we hypothesized that adding probiotics to a blueberry-enriched diet would augment the anti-hypertensive effects of blueberry consumption. Groups (n = 8) of male spontaneously hypertensive rats were fed one of four AIN '93G-based diets for 8 weeks: Control (CON); 3% freeze-dried wild blueberry (BB); 1% probiotic bacteria (PRO); or 3% BB + 1% PRO (BB+PRO). Blood pressure was measured at weeks 0, 2, 4, 6, and 8 by the tail-cuff method, and urine was collected at weeks 4 and 8 to determine markers of oxidative stress (F2-isoprostanes), nitric oxide synthesis (nitrites), and polyphenol metabolism (hippuric acid). Data were analyzed using mixed models ANOVA with repeated measures. Diet had a significant main effect on diastolic blood pressure (p = 0.046), with significantly lower measurements in the BB- vs. CON-fed rats (p = 0.035). Systolic blood pressure showed a similar but less pronounced response to diet (p = 0.220), again with the largest difference between the BB and CON groups. Absolute increase in blood pressure between weeks 0 and 8 tended to be smaller in the BB and PRO vs. CON and BB+PRO groups (systolic increase, p = 0.074; diastolic increase, p = 0.185). Diet had a significant main effect on hippuric acid excretion (pblueberry-enriched diet does not enhance and actually may impair the anti-hypertensive effect of blueberry consumption. However, probiotic bacteria are not interfering with blueberry polyphenol metabolism into hippuric acid.

  13. Probiotics Blunt the Anti-Hypertensive Effect of Blueberry Feeding in Hypertensive Rats without Altering Hippuric Acid Production.

    Directory of Open Access Journals (Sweden)

    Cynthia Blanton

    Full Text Available Previously we showed that feeding polyphenol-rich wild blueberries to hypertensive rats lowered systolic blood pressure. Since probiotic bacteria produce bioactive metabolites from berry polyphenols that enhance the health benefits of berry consumption, we hypothesized that adding probiotics to a blueberry-enriched diet would augment the anti-hypertensive effects of blueberry consumption. Groups (n = 8 of male spontaneously hypertensive rats were fed one of four AIN '93G-based diets for 8 weeks: Control (CON; 3% freeze-dried wild blueberry (BB; 1% probiotic bacteria (PRO; or 3% BB + 1% PRO (BB+PRO. Blood pressure was measured at weeks 0, 2, 4, 6, and 8 by the tail-cuff method, and urine was collected at weeks 4 and 8 to determine markers of oxidative stress (F2-isoprostanes, nitric oxide synthesis (nitrites, and polyphenol metabolism (hippuric acid. Data were analyzed using mixed models ANOVA with repeated measures. Diet had a significant main effect on diastolic blood pressure (p = 0.046, with significantly lower measurements in the BB- vs. CON-fed rats (p = 0.035. Systolic blood pressure showed a similar but less pronounced response to diet (p = 0.220, again with the largest difference between the BB and CON groups. Absolute increase in blood pressure between weeks 0 and 8 tended to be smaller in the BB and PRO vs. CON and BB+PRO groups (systolic increase, p = 0.074; diastolic increase, p = 0.185. Diet had a significant main effect on hippuric acid excretion (p<0.0001, with 2- and ~1.5-fold higher levels at weeks 4 and 8, respectively, in the BB and BB+PRO vs. PRO and CON groups. Diet did not have a significant main effect on F2-isoprostane (p = 0.159 or nitrite excretion (p = 0.670. Our findings show that adding probiotics to a blueberry-enriched diet does not enhance and actually may impair the anti-hypertensive effect of blueberry consumption. However, probiotic bacteria are not interfering with blueberry polyphenol metabolism into hippuric

  14. A blunted anxiolytic like effect of curcumin against acute lead induced anxiety in rat: involvement of serotonin.

    Science.gov (United States)

    Benammi, Hind; El Hiba, Omar; Romane, Abderrahmane; Gamrani, Halima

    2014-06-01

    Anxiety is one of the most common mental disorders sharing extreme or pathological anxiety states as the primary disturbance in mood or emotional tone, with increased fear and exaggerated acute stress responses. Medicinal plants are very variable, but some of them are used as a spice such as curcumin (Curcuma longa). Curcumin shows a wide range of pharmacological potentialities, however, little is known about its anxiolytic properties. The aim of our study was to assess the anti-anxiety potential of curcumin extract against experimental lead induced-anxiety in rats. Experiments were carried out on male Wistar rats intoxicated acutely with an intraperitoneal injection of Pb (25mg/kg B.W.) and/or concomitantly with administration of curcumin (30 mg/kg B.W.) for 3 days. Using immunohistochemistry and anxiety assessment tests (dark light box and elevated plus maze), we evaluated, respectively, the expression of serotonin (5HT) in the dorsal raphe nucleus (DRN) and the anxiety state in our animals. Our results showed, for the first time, a noticeable anxiolytic effect of curcumin against lead induced anxiety in rats and this may possibly result from modulation of central neuronal monoaminergic neurotransmission, especially serotonin, which has shown a significant reduction of the immunoreactivity within the DRN. Copyright © 2014 Elsevier GmbH. All rights reserved.

  15. Angled shots onto body armour using 9 mm ammunition: the effect on potential blunt injury.

    Science.gov (United States)

    Lyall, Alison; Carr, D J; Lankester, C; Malbon, C

    2017-02-01

    Some military specialists wear body armour that is more similar to police armour and provides protection from ammunition fired from pistols. During ballistic testing, these armours are mounted on a standardised type of modelling clay and the back face signature (BFS; depth of depression) formed as a result of the non-perforating impact event on to the armour is measured. This study investigated the effect of impact angle on the BFS and on the deformation of the bullet. Two commonly worn types of armour (HG1/A+KR1 and HG1+KR1) were considered that provide protection from pistol ammunition and sharp weapons. Armours were tested against two types of pistol ammunition (9 mm full metal jacket and 9 mm hollow point) at eight different impact angles (0°, 15°, 30°, 45°, 60°, 70°, 75° and 80°). Increased impact angles resulted in smaller BFSs. Impact angle also affected whether bullets were retained in the armour; as the impact angle increased, the probability of a round exiting the side of the armour increased. Bullet deformation was affected by impact angle. Understanding the deformation of bullets may assist with recreating a shooting incident and interpreting forensic evidence. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  16. Emotional blunting with antidepressant treatments: A survey among depressed patients.

    Science.gov (United States)

    Goodwin, G M; Price, J; De Bodinat, C; Laredo, J

    2017-10-15

    Emotional blunting is regularly reported in depressed patients on antidepressant treatment but its actual frequency is poorly understood. We have previously used qualitative methods to develop an appropriate scale, the Oxford Questionnaire on the Emotional Side-Effects of Antidepressants (OQESA). Six hundred and sixty nine depressed patients on treatment and 150 recovered (formerly depressed) controls (aged ≥18 years) participated in this internet-based survey. The rate of emotional blunting in treated depressed patients was 46%, slightly more frequent in men than women (52% versus 44%) and in those with higher Hospital Anxiety and Depression (HAD) scale scores. There was no difference according to antidepressant agent, though it appeared less frequent with bupropion. Depressed patients with emotional blunting had much higher total blunting scores on OQESA than controls (42.83 ± 14.73 versus 25.73 ± 15.00, p 7 (n = 170) had a higher total questionnaire score, 49.23±12.03, than those with HAD-D score ≤7 (n = 140), 35.07 ± 13.98, and the difference between the two groups was highly significant. However, patients with HAD-D score ≤7 (n = 140) had a higher total score (35.07 ± 13.98) than the recovered controls (n = 150) (25.73 ± 15.00), and the difference between the two groups was significant. Among the patients with emotional blunting, 37% had a negative perception of their condition and 38% positive. Men reported a more negative perception than women (p=0.008), and patients with a negative perception were more likely to have higher HAD scores. Higher levels of emotional blunting are associated with a more negative perception of it by the patient (r = -0.423). Include self-evaluation and the modest size of the sample for detection of differences between antidepressants. Emotional blunting is reported by nearly half of depressed patients on antidepressants. It appears to be common to all monoaminergic antidepressants. The OQESA scores are highly

  17. Endovascular repair of blunt popliteal arterial injuries

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Shan; Zhang, Xiquan; Chen, Zhong; Zhu, Wei; Pan, Xiaolin [Dept. of nterventional Vascular, The 148th Hospital of Chinese People' s Liberation Army, Zibo (China); Dong, Peng; Sun, Yequan [Dept. of Medical Imaging, Weifang Medical University, Weifang (China); Qi, Deming [Dept. of Medical Imaging, Qilu Medical University, Zibo (China)

    2016-09-15

    To evaluate the feasibility and effectiveness of endovascular repair for blunt popliteal arterial injuries. A retrospective analysis of seven patients with clinical suspicion of popliteal arterial injuries that were confirmed by arteriography was performed from September 2009 to July 2014. Clinical data included demographics, mechanism of injury, type of injury, location of injury, concomitant injuries, time of endovascular procedures, time interval from trauma to blood flow restoration, instrument utilized, and follow-up. All patients were male (mean age of 35.9 ± 10.3 years). The type of lesion involved intimal injury (n = 1), partial transection (n = 2), complete transection (n = 2), arteriovenous fistula (n = 1), and pseudoaneurysm (n = 1). All patients underwent endovascular repair of blunt popliteal arterial injuries. Technical success rate was 100%. Intimal injury was treated with a bare-metal stent. Pseudoaneurysm and popliteal artery transections were treated with bare-metal stents. Arteriovenous fistula was treated with bare-metal stent and coils. No perioperative death and procedure-related complication occurred. The average follow-up was 20.9 ± 2.3 months (range 18–24 months). One patient underwent intra-arterial thrombolysis due to stent thrombosis at 18 months after the procedure. All limbs were salvaged. Stent migration, deformation, or fracture was not found during the follow-up. Endovascular repair seems to be a viable approach for patients with blunt popliteal arterial injuries, especially on an emergency basis. Endovascular repair may be effective in the short-term. Further studies are required to evaluate the long-term efficacy of endovascular repair.

  18. EMA: a developmentally regulated cell-surface glycoprotein of CNS neurons that is concentrated at the leading edge of growth cones.

    Science.gov (United States)

    Baumrind, N L; Parkinson, D; Wayne, D B; Heuser, J E; Pearlman, A L

    1992-08-01

    To identify cell-surface molecules that mediate interactions between neurons and their environment during neural development, we used monoclonal antibody techniques to define a developmentally regulated antigen in the central nervous system of the mouse. The antibody we produced (2A1) immunolabels cells throughout the central nervous system; we analyzed its distribution in the developing cerebral cortex, where it is expressed on cells very soon after they complete mitosis and leave the periventricular proliferative zone. Expression continues into adult life. The antibody also labels the epithelium of the choroid plexus and the renal proximal tubules, but does not label neurons of the peripheral nervous system in the dorsal root ganglia. In dissociated cell culture of embryonic cerebral cortex, 2A1 labels the surface of neurons but not glia. Immunolabeling of neurons in tissue culture is particularly prominent on the edge of growth cones, including filopodia and the leading edge of lamellipodia, when observed with either immunofluorescence or freeze-etch immunoelectron microscopy. Immunopurification with 2A1 of a CHAPS-extracted membrane preparation from brains of neonatal mice produces a broad (32-36 kD) electrophoretic band and a less prominent 70 kD band that are sensitive to N-glycosidase but not endoglycosidase H. Thus the 2A1 antibody recognizes a developmentally regulated, neuronal cell surface glycoprotein (or glycoproteins) with complex N-linked oligosaccharide side chains. We have termed the glycoprotein antigen EMA because of its prominence on the edge membrane of growth cones. EMA is similar to the M6 antigen (Lagenaur et al: J. Neurobiol. 23:71-88, 1992) in apparent molecular weight, distribution in tissue sections, and immunoreactivity on Western blots, suggesting that the two antigens are similar or identical. Expression of EMA is a very early manifestation of neuronal differentiation; its distribution on growth cones suggests a role in mediating the

  19. Effects on mortality, treatment, and time management as a result of routine use of total body computed tomography in blunt high-energy trauma patients.

    Science.gov (United States)

    van Vugt, Raoul; Kool, Digna R; Deunk, Jaap; Edwards, Michael J R

    2012-03-01

    Currently, total body computed tomography (TBCT) is rapidly implemented in the evaluation of trauma patients. With this review, we aim to evaluate the clinical implications-mortality, change in treatment, and time management-of the routine use of TBCT in adult blunt high-energy trauma patients compared with a conservative approach with the use of conventional radiography, ultrasound, and selective computed tomography. A literature search for original studies on TBCT in blunt high-energy trauma patients was performed. Two independent observers included studies concerning mortality, change of treatment, and/or time management as outcome measures. For each article, relevant data were extracted and analyzed. In addition, the quality according to the Oxford levels of evidence was assessed. From 183 articles initially identified, the observers included nine original studies in consensus. One of three studies described a significant difference in mortality; four described a change of treatment in 2% to 27% of patients because of the use of TBCT. Five studies found a gain in time with the use of immediate routine TBCT. Eight studies scored a level of evidence of 2b and one of 3b. Current literature has predominantly suboptimal design to prove terminally that the routine use of TBCT results in improved survival of blunt high-energy trauma patients. TBCT can give a change of treatment and improves time intervals in the emergency department as compared with its selective use.

  20. The helicase, DDX3X, interacts with poly(A)-binding protein 1 (PABP1) and caprin-1 at the leading edge of migrating fibroblasts and is required for efficient cell spreading.

    Science.gov (United States)

    Copsey, Alice C; Cooper, Simon; Parker, Robert; Lineham, Ella; Lapworth, Cuzack; Jallad, Deema; Sweet, Steve; Morley, Simon J

    2017-08-30

    DDX3X, a helicase, can interact directly with mRNA and translation initiation factors, regulating the selective translation of mRNAs that contain a structured 5' untranslated region. This activity modulates the expression of mRNAs controlling cell cycle progression and mRNAs regulating actin dynamics, contributing to cell adhesion and motility. Previously, we have shown that ribosomes and translation initiation factors localise to the leading edge of migrating fibroblasts in loci enriched with actively translating ribosomes, thereby promoting steady-state levels of ArpC2 and Rac1 proteins at the leading edge of cells during spreading. As DDX3X can regulate Rac1 levels, cell motility and metastasis, we have examined DDX3X protein interactions and localisation using many complementary approaches. We now show that DDX3X can physically interact and co-localise with poly(A)-binding protein 1 and caprin-1 at the leading edge of spreading cells. Furthermore, as depletion of DDX3X leads to decreased cell motility, this provides a functional link between DDX3X, caprin-1 and initiation factors at the leading edge of migrating cells to promote cell migration and spreading. © 2017 The Author(s).

  1. Imaging of blunt chest trauma

    International Nuclear Information System (INIS)

    Wicky, S.; Wintermark, M.; Schnyder, P.; Capasso, P.; Denys, A.

    2000-01-01

    In western European countries most blunt chest traumas are associated with motor vehicle and sport-related accidents. In Switzerland, 39 of 10,000 inhabitants were involved and severely injured in road accidents in 1998. Fifty two percent of them suffered from blunt chest trauma. According to the Swiss Federal Office of Statistics, traumas represented in men the fourth major cause of death (4 %) after cardiovascular disease (38 %), cancer (28 %), and respiratory disease (7 %) in 1998. The outcome of chest trauma patients is determined mainly by the severity of the lesions, the prompt appropriate treatment delivered on the scene of the accident, the time needed to transport the patient to a trauma center, and the immediate recognition of the lesions by a trained emergency team. Other determining factors include age as well as coexisting cardiac, pulmonary, and renal diseases. Our purpose was to review the wide spectrum of pathologies related to blunt chest trauma involving the chest wall, pleura, lungs, trachea and bronchi, aorta, aortic arch vessels, and diaphragm. A particular focus on the diagnostic impact of CT is demonstrated. (orig.)

  2. Appendicitis following blunt abdominal trauma.

    Science.gov (United States)

    Cobb, Travis

    2017-09-01

    Appendicitis is a frequently encountered surgical problem in the Emergency Department (ED). Appendicitis typically results from obstruction of the appendiceal lumen, although trauma has been reported as an infrequent cause of acute appendicitis. Intestinal injury and hollow viscus injury following blunt abdominal trauma are well reported in the literature but traumatic appendicitis is much less common. The pathophysiology is uncertain but likely results from several mechanisms, either in isolation or combination. These include direct compression/crush injury, shearing injury, or from indirect obstruction of the appendiceal lumen by an ileocecal hematoma or traumatic impaction of stool into the appendix. Presentation typically mirrors that of non-traumatic appendicitis with nausea, anorexia, fever, and right lower quadrant abdominal tenderness and/or peritonitis. Evaluation for traumatic appendicitis requires a careful history and physical exam. Imaging with ultrasound or computed tomography is recommended if the history and physical do not reveal an acute surgical indication. Treatment includes intravenous antibiotics and surgical consultation for appendectomy. This case highlights a patient who developed acute appendicitis following blunt trauma to the abdomen sustained during a motor vehicle accident. Appendicitis must be considered as part of the differential diagnosis in any patient who presents to the ED with abdominal pain, including those whose pain begins after sustaining blunt trauma to the abdomen. Because appendicitis following trauma is uncommon, timely diagnosis requires a high index of suspicion. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Superior Reproducibility of the Leading to Leading Edge and Inner to Inner Edge Methods in the Ultrasound Assessment of Maximum Abdominal Aortic Diameter.

    Science.gov (United States)

    Borgbjerg, Jens; Bøgsted, Martin; Lindholt, Jes S; Behr-Rasmussen, Carsten; Hørlyck, Arne; Frøkjær, Jens B

    2018-02-01

    Controversy exists regarding optimal caliper placement in ultrasound assessment of maximum abdominal aortic diameter. This study aimed primarily to determine reproducibility of caliper placement in relation to the aortic wall with the three principal methods: leading to leading edge (LTL), inner to inner edge (ITI), and outer to outer edge (OTO). The secondary aim was to assess the mean difference between the OTO, ITI, and LTL diameters and estimate the impact of using either of these methods on abdominal aortic aneurysm (AAA) prevalence in a screening program. Radiologists (n=18) assessed the maximum antero-posterior abdominal aortic diameter by completing repeated caliper placements with the OTO, LTL, and ITI methods on 50 still abdominal aortic images obtained from an AAA screening program. Inter-observer reproducibility was calculated as the limit of agreement with the mean (LoA), which represents expected deviation of a single observer from the mean of all observers. Intra-observer reproducibility was assessed averaging the LoA for each observer with their repeated measurements. Based on data from an AAA screening trial and the estimated mean differences between the three principal methods, AAA prevalence was estimated using each of the methods. The inter-observer LoA of the OTO, ITI, and LTL was 2.6, 1.9, and 1.9 mm, whereas the intra-observer LoA was 2.0, 1.6, and 1.5 mm, respectively. Mean differences of 5.0 mm were found between OTO and ITI measurements, 2.6 mm between OTO and LTL measurements, and 2.4 mm between LTL and ITI measurements. The prevalence of AAA almost doubled using OTO instead of ITI, while the difference between ITI and LTL was minor (3.3% vs. 4.0% AAA). The study shows superior reproducibility of LTL and ITI compared with the OTO method of caliper placement in ultrasound determination of maximum abdominal aortic diameter, and the choice of caliper placement method significantly affects the prevalence of AAAs in screening programs

  4. Splenic abscess after splenic blunt injury angioembolization.

    Science.gov (United States)

    Tartaglia, Dario; Galatioto, Christian; Lippolis, Piero Vincenzo; Modesti, Matteo; Gianardi, Desirée; Bertolucci, Andrea; Cucinotta, Monica; Zocco, Giuseppe; Seccia, Massimo

    2014-11-03

    Splenic Angioembolization (SAE), during Nonoperative Management (NOM) of Blunt Splenic Injury (BSI), is an effective therapy for hemodynamically stable patients with grade III, IV, and V OIS splenic injuries. We report a case of a patient with a blunt abdominal trauma due to an accidental fall, who presented splenic abscess a week after SAE and a review of the literature. A 38-year-old male arrived at Emergency after an accidental fall with contusion of the left upper quadrant of the abdomen. Abdominal CT scan revealed the fracture of the lower splenic pole with intraparenchymal pseudoaneurysms (OIS spleen injury scale IV). Considering the hemodynamic stability, NOM was undertaken and SAE was performed. After a week, the patient developed a splenic abscess confirmed by Abdominal CT; therefore, splenectomy was performed. There was no evidence of bacterial growing in the perisplenic hematoma cultures but the histological examination showed multiple abscess and hemorrhagic areas in the spleen. Splenic abscess after SAE during NOM of BSI is a rare major complication. The most frequently cultured organisms include Clostridium perfringens, Alpha-Hemoliticus Streptococcus, gram-positive Staphylococcus, gram-negative Salmonella, Candida, and Aspergillus. This case represents our first reported splenic abscess after SAE. SAE is a very useful tool for BSI managing; splenic abscess can occur in a short time, even if it is a rare major complication, so it may be useful to monitor patients undergoing SAE, focusing not only on the hemodynamic parameters but also on the inflammatory and infectious aspects.

  5. Study of airfoil trailing edge bluntness noise

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2010-01-01

    This paper deals with airfoil trailing edge noise with special focus on airfoils with blunt trailing edges. Two methods are employed to calculate airfoil noise: The flow/acoustic splitting method and the semi-empirical method. The flow/acoustic splitting method is derived from compressible Navier...... design or optimization. Calculations from both methods are compared with exist experiments. The airfoil blunt noise is found as a function of trailing edge bluntness, Reynolds number, angle of attack, etc....

  6. Microstructural modelling of creep crack growth from a blunted crack

    NARCIS (Netherlands)

    Onck, P.R.; Giessen, E. van der

    1998-01-01

    The effect of crack tip blunting on the initial stages of creep crack growth is investigated by means of a planar microstructural model in which grains are represented discretely. The actual linking-up process of discrete microcracks with the macroscopic crack is simulated, with full account of the

  7. (PCR) for direct cloning of blunt-end DNA fragments

    African Journals Online (AJOL)

    Administrator

    2011-09-19

    Sep 19, 2011 ... Key words: Blunt-end cloning, phosphorylated DNA fragment, dephosphorylated blunt-end vector. INTRODUCTION ... With this method, a lot of steps are saved, which includes restriction .... pBSK-blunt (data not shown).

  8. A hybrid CFD/characteristics method for fast characterization of hypersonic blunt forebody/inlet flow

    Science.gov (United States)

    Gao, WenZhi; Li, ZhuFei; Yang, JiMing

    2015-10-01

    A hybrid CFD/characteristic method (CCM) was proposed for fast design and evaluation of hypersonic inlet flow with nose bluntness, which targets the combined advantages of CFD and method of characteristics. Both the accuracy and efficiency of the developed CCM were verified reliably, and it was well demonstrated for the external surfaces design of a hypersonic forebody/inlet with nose bluntness. With the help of CCM method, effects of nose bluntness on forebody shock shapes and the flowfield qualities which dominate inlet performance were examined and analyzed on the two-dimensional and axisymmetric configurations. The results showed that blunt effects of a wedge forebody are more substantial than that of related cone cases. For a conical forebody with a properly blunted nose, a recovery of the shock front back to that of corresponding sharp nose is exhibited, accompanied with a gradually fading out of entropy layer effects. Consequently a simplification is thought to be reasonable for an axisymmetric inlet with a proper compression angle, and a blunt nose of limited radius can be idealized as a sharp nose, as the spillage and flow variations at the entrance are negligible, even though the nose scale increases to 10% cowl lip radius. Whereas for two-dimensional inlets, the blunt effects are substantial since not only the inlet capturing/starting capabilities, but also the flow uniformities are obviously degraded.

  9. Hernia Following Blunt Abdominal Trauma

    Directory of Open Access Journals (Sweden)

    N Aghaie

    2009-10-01

    Full Text Available Traumatic abdominal wall hernia is a rare type of hernia, which follows blunt trauma to the abdomen, where disruption of the musculature and fascia occurs with the overlying skin remaining intact. Diagnosis of this problem is very difficult and delayed. Traumatic hernia is often diagnosed during laparatomy or laparascopy, but CT scan also has a role in distinguishing this pathology. Delay in diagnosis is very dangerous and can result in gangrene and necrosis of the organs in the hernia. The case report of a 35 years old man with liftruck blunt trauma is reported. His vital signs were stable. On physical examination, tenderness of RUQ was seen. He underwent Dpl for suspected hemoprotein. Dpl was followed up by laparatomy. Laparatomy revealed that the transverse and ascending colon partially herniated in the abdominal wall defect. The colon was reduced in the abdomen and repair of abdominal hernia was done. The patient was discharged after 5 day. The etiology, pathogenesis and management are discussed.

  10. Blunt abdominal trauma in children.

    Science.gov (United States)

    Schonfeld, Deborah; Lee, Lois K

    2012-06-01

    This review will examine the current evidence regarding pediatric blunt abdominal trauma and the physical exam findings, laboratory values, and radiographic imaging associated with the diagnosis of intra-abdominal injuries (IAI), as well as review the current literature on pediatric hollow viscus injuries and emergency department disposition after diagnosis. The importance of the seat belt sign on physical examination and screening laboratory data remains controversial, although screening hepatic enzymes are recommended in the evaluation of nonaccidental trauma to identify occult abdominal organ injuries. Focused Assessment with Sonography for Trauma (FAST) has modest sensitivity for hemoperitoneum and IAI in the pediatric trauma patient. Patients with concern for undiagnosed IAI, including bowel injury, may be considered for hospital admission and serial abdominal exams without an increased risk of complications, if an exploratory laparotomy is not performed emergently. Although the FAST exam is not recommended as the sole screening tool to rule out IAI in hemodynamically stable trauma patients, it may be used in conjunction with the physical exam and laboratory findings to identify children at risk for IAI. Children with a normal physical exam and normal abdominal CT may not require routine hospitalization after blunt abdominal trauma.

  11. Management of adult blunt hepatic trauma.

    Science.gov (United States)

    Kozar, Rosemary A; McNutt, Michelle K

    2010-12-01

    To review the nonoperative and operative management of blunt hepatic injury in the adult trauma population. Although liver injury scale does not predict need for surgical intervention, a high-grade complex liver injury should alert the physician to a patient at increased risk of hepatic complications following nonoperative management. Blunt hepatic injury remains a frequent intraabdominal injury in the adult trauma population. The management of blunt hepatic injury has undergone a major paradigm shift from mandatory operative exploration to nonoperative management. Hemodynamic instability with a positive focused abdominal sonography for trauma and peritonitis are indications for emergent operative intervention. Although surgical intervention for blunt hepatic trauma is not as common as in years past, it is imperative that the current trauma surgeon be familiar with the surgical skill set to manage complex hepatic injuries. This study represents a review of both nonoperative and operative management of blunt hepatic injury.

  12. Evaluation and Management of Blunt Solid Organ Trauma.

    Science.gov (United States)

    Martin, Jonathan G; Shah, Jay; Robinson, Craig; Dariushnia, Sean

    2017-12-01

    Trauma is a leading cause of death in patients under the age of 45 and generally associated with a high kinetic energy event such as a motor vehicle accident or fall from extreme elevations. Blunt trauma can affect every organ system and major vascular structure with potentially devastating effect. When we consider abdominal solid organ injury from blunt trauma, we usually think of the liver, spleen, and kidneys. However, all of the abdominal organs, including the pancreas and adrenal glands, may be involved. Blunt hepatic trauma is more commonly associated with venous bleeding rather than arterial injury. Stable venous injury is often managed conservatively; when the patient is hemodynamically unstable from venous hepatic injury, operative management should be first-line therapy. When the injury is arterial, endovascular therapy should be initiated. Blunt trauma to the spleen is the most common cause of traumatic injury to the spleen. Management is controversial. In our institution unstable patients are taken to the operating room, and stable patients with Grades IV-V injuries and patients with active arterial injury are taken for endovascular treatment. Renal injuries are less common, and evidence of arterial injury such as active extravasation or pseudoaneurysm is warranted before endovascular therapy. Pancreatic trauma is uncommon and usually secondary to steering wheel/handlebar mechanism injuries. Adrenal injuries are rare in the absence of megatrauma or underlying adrenal abnormality. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Blunted stress reactivity in chronic cannabis users.

    Science.gov (United States)

    Cuttler, Carrie; Spradlin, Alexander; Nusbaum, Amy T; Whitney, Paul; Hinson, John M; McLaughlin, Ryan J

    2017-08-01

    One of the most commonly cited reasons for chronic cannabis use is to cope with stress. Consistent with this, cannabis users have shown reduced emotional arousal and dampened stress reactivity in response to negative imagery. To our knowledge, the present study represents the first to examine the effects of an acute stress manipulation on subjective stress and salivary cortisol in chronic cannabis users compared to non-users. Forty cannabis users and 42 non-users were randomly assigned to complete either the stress or no stress conditions of the Maastricht Acute Stress Test (MAST). The stress condition of the MAST manipulates both physiological (placing hand in ice bath) and psychosocial stress (performing math under conditions of social evaluation). Participants gave baseline subjective stress ratings before, during, and after the stress manipulation. Cortisol was measured from saliva samples obtained before and after the stress manipulation. Further, cannabis cravings and symptoms of withdrawal were measured. Subjective stress ratings and cortisol levels were significantly higher in non-users in the stress condition relative to non-users in the no stress condition. In contrast, cannabis users demonstrated blunted stress reactivity; specifically, they showed no increase in cortisol and a significantly smaller increase in subjective stress ratings. The stress manipulation had no impact on cannabis users' self-reported cravings or withdrawal symptoms. Chronic cannabis use is associated with blunted stress reactivity. Future research is needed to determine whether this helps to confer resiliency or vulnerability to stress-related psychopathology as well as the mechanisms underlying this effect.

  14. Combat Helmet-Headform Coupling Characterized from Blunt Impact Events

    Science.gov (United States)

    2011-11-01

    Testing was completed on a monorail drop tower to analyze the effect of helmet/headform coupling on the blunt impact behavior of ACH helmets using FMVSS...designates its own methods and test equipment: a drop tower ( monorail or twin- wire), headform (DOT, ISO, NOCSAE), headform CG accelerometer (single or...the more anthropomorphic International Standard Organization (ISO) half headform. Testing was completed on a monorail drop tower to analyze the effect

  15. Blunt carotid and vertebral artery injuries.

    Science.gov (United States)

    Arthurs, Zachary M; Starnes, Benjamin W

    2008-11-01

    The recognition and treatment of blunt cerebrovascular injuries has dramatically evolved over the past two decades. As imaging technology has improved both with respect to the image quality and acquisition times, its use has become a fundamental diagnostic tool in blunt trauma evaluation. The single greatest radiological advance in the past quarter century has been the refinement and increasing use of computed tomographic imaging for the diagnosis of surgical disease. Paralleling advances in noninvasive imaging, a heightened awareness of blunt cerebrovascular injuries has emerged, and the first screening protocols were developed at high volume trauma centres. Through aggressive screening, these injuries have increasingly been recognised before devastating neurological ischaemia and adverse neurocognitive outcomes. The mainstay of treatment for these injuries is antithrombotic therapy. However, all blunt cerebrovascular injuries require short and long-term follow-up. While the majority of injuries will resolve with medical management, a proportion will require further intervention in order to reduce the risk of subsequent stroke.

  16. Acute appendicitis after blunt abdominal trauma

    Directory of Open Access Journals (Sweden)

    Marjan Joudi

    2012-02-01

    Full Text Available Appendecitis is one of the most frequent surgeries. Inflammation of appendix may be due to variable causes such as fecalit, hypertrophy of Peyer’s plaques, seeds of fruits and parasites. In this study we presented an uncommon type of appendicitis which occurred after abdominal blunt trauma. In this article three children present who involved acute appendicitis after blunt abdominal trauma. These patients were 2 boys (5 and 6-year-old and one girl (8-year-old who after blunt abdominal trauma admitted to the hospital with abdominal pain and symptoms of acute abdomen and appendectomy had been done for them.Trauma can induce intramural hematoma at appendix process and may cause appendicitis. Therefore, physicians should be aware of appendicitis after blunt abdominal trauma

  17. Duodenal Transection without Pancreatic Injury following Blunt ...

    African Journals Online (AJOL)

    following blunt abdominal trauma and its clinical picture is often ... Here we report a case of complete duodenal ... Key words: Duodenal injury, peritonitis, transection. Department of ... When our patient was brought to the emergency room, he.

  18. Blunt cardiac rupture in a toddler

    Directory of Open Access Journals (Sweden)

    Peep Talving

    2016-08-01

    Full Text Available Blunt cardiac rupture is typically a fatal injury with overall mortality exceeding 90%. Most of the patients never reach the hospital alive. In pediatric patients, only 0.03% of cases following blunt trauma admissions have a cardiac injury. This report presents a rare survivor of 16-months old toddler injured in a domestic accident suffering a right atrial rupture repaired through a median sternotomy. To the best of our knowledge this is the youngest case reported in the literature.

  19. Transcatheter Embolization for Delayed Hemorrhage Caused by Blunt Splenic Trauma

    International Nuclear Information System (INIS)

    Krohmer, Steven J.; Hoffer, Eric K.; Burchard, Kenneth W.

    2010-01-01

    Although the exact benefit of adjunctive splenic artery embolization (SAE) in the nonoperative management (NOM) of patients with blunt splenic trauma has been debated, the role of transcatheter embolization in delayed splenic hemorrhage is rarely addressed. The purpose of this study was to evaluate the effectiveness of SAE in the management of patients who presented at least 3 days after initial splenic trauma with delayed hemorrhage. During a 24-month period 4 patients (all male; ages 19-49 years) presented with acute onset of pain 5-70 days after blunt trauma to the left upper quadrant. Two had known splenic injuries that had been managed nonoperatively. All had computed axial tomography evidence of active splenic hemorrhage or false aneurysm on representation. All underwent successful SAE. Follow-up ranged from 28 to 370 days. These cases and a review of the literature indicate that SAE is safe and effective for NOM failure caused by delayed manifestations of splenic arterial injury.

  20. Cardiogenic shock following blunt chest trauma

    Directory of Open Access Journals (Sweden)

    Rodríguez-González Fayna

    2010-01-01

    Full Text Available Cardiac contusion, usually caused by blunt chest trauma, has been recognized with increased frequency over the past decades. Traffic accidents are the most frequent cause of cardiac contusions resulting from a direct blow to the chest. Other causes of blunt cardiac injury are numerous and include violent fall impacts, interpersonal aggression, explosions, and various types of high-risk sports. Myocardial contusion is difficult to diagnose; clinical presentation varies greatly, ranging from lack of symptoms to cardiogenic shock and arrhythmia. Although death is rare, cardiac contusion can be fatal. We present a case of cardiac contusion due to blunt chest trauma secondary to a fall impact, which manifested as cardiogenic shock.

  1. Aerothermodynamics of blunt body entry vehicles

    Science.gov (United States)

    Hollis, Brian R.; Borrelli, Salvatore

    2012-01-01

    In this chapter, the aerothermodynamic phenomena of blunt body entry vehicles are discussed. Four topics will be considered that present challenges to current computational modeling techniques for blunt body environments: turbulent flow, non-equilibrium flow, rarefied flow, and radiation transport. Examples of comparisons between computational tools to ground and flight-test data will be presented in order to illustrate the challenges existing in the numerical modeling of each of these phenomena and to provide test cases for evaluation of computational fluid dynamics (CFD) code predictions.

  2. [Surgical Repair for Blunt Cardiac Rupture].

    Science.gov (United States)

    Yashiki, Noriyoshi; Yachi, Tsuyoshi; Takahashi, Tomohiko

    2017-07-01

    Blunt cardiac injury is a life-threatening condition. We report 3 successful cases in which we performed surgery for blunt cardiac injury. Three individuals were injured, 2 in traffic accidents and the other being caught between a crane and a steel frame. Echocardiograms and computed tomography scans revealed pooling of bloody pericardial fluid in all 3 patients, who underwent emergency surgery. Two patients needed sutures to control persistent bleeding. Although a heart-lung machine was prepared at the start of surgery in all 3 cases, we did not need to use it for any patient. Thus, prior to performing such surgery, it is necessary to ascertain its need.

  3. Isolated jejunal perforation following blunt abdominal trauma

    Directory of Open Access Journals (Sweden)

    Ahmet Pergel

    2012-09-01

    Full Text Available Isolated perforation of the jejunum, following blunt abdominaltrauma, is extremely rare. These injuries aredifficult to diagnose because initial clinical signs are frequentlynonspecific and a delay in treatment increasesmortality and morbidity of the patients. Conventional radiogramsare often inadequate for diagnosing this subsetof trauma. For an accurate and timely diagnosis, thepossibility of bowel perforation and the need for repeatedexaminations should be kept in mind. Herein, we presenta 28-year-old man with isolated jejunal perforation followingblunt abdominal trauma.Key words: Blunt abdominal trauma, isolated jejunal perforation,early diagnosis

  4. Roentgenologic evaluation of blunt abdominal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Zoon; Ra, Woo Youn; Woo, Won Hyung [Hankang Sacred heart Hospital, Chung Ang University School of Medicine, Seoul (Korea, Republic of)

    1974-10-15

    This study comprises 25 cases of blunt abdominal trauma proved by surgery. It is concluded that visceral damage by blunt abdominal trauma may be suspected, but can not be satisfactorily diagnosed upon a single plane abdominal roentgenologic examination with clinical support. Contrary to some reports in the literature, rupture of the hallow, viscus is more susceptible than solid organ and ileum is more than jejunum. It is a useful roentgenologic sign denoting distension and small cresent air shadow in the duodenal sweep of the damaged pancreas.

  5. Aerodynamics and Heat Transfer Studies of Parameters Specific to the IGCC-Requirements: Endwall Contouring, Leading Edge and Blade Tip Ejection under Rotating Turbine Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schobeiri, Meinhard; Han, Je-Chin

    2014-09-30

    This report deals with the specific aerodynamics and heat transfer problematic inherent to high pressure (HP) turbine sections of IGCC-gas turbines. Issues of primary relevance to a turbine stage operating in an IGCC-environment are: (1) decreasing the strength of the secondary flow vortices at the hub and tip regions to reduce (a), the secondary flow losses and (b), the potential for end wall deposition, erosion and corrosion due to secondary flow driven migration of gas flow particles to the hub and tip regions, (2) providing a robust film cooling technology at the hub and that sustains high cooling effectiveness less sensitive to deposition, (3) investigating the impact of blade tip geometry on film cooling effectiveness. The document includes numerical and experimental investigations of above issues. The experimental investigations were performed in the three-stage multi-purpose turbine research facility at the Turbomachinery Performance and Flow Research Laboratory (TPFL), Texas A&M University. For the numerical investigations a commercial Navier-Stokes solver was utilized.

  6. 64-MDCT angiography of blunt vascular injuries of the neck.

    Science.gov (United States)

    Chokshi, Falgun H; Munera, Felipe; Rivas, Luis A; Henry, Robert P; Quencer, Robert M

    2011-03-01

    CT angiography (CTA) using 64-MDCT enables timely evaluation of injuries associated with blunt neck trauma. The purpose of this article is to familiarize the reader with the most frequent CTA signs of blunt vascular injury. CTA is a valuable tool to detect blunt vascular injuries, especially using its multiplanar and 3D reconstruction capabilities.

  7. Tetanus after blunt lawn mower trauma

    Directory of Open Access Journals (Sweden)

    Camilla Normand

    2015-01-01

    Full Text Available A patient presented with tetanus ten days after blunt trauma with a lawn mower. Our case describes the diagnosis and treatment of this patient with an infectious disease commonly seen in the developing world but rarely seen in the developed world.

  8. Tetanus after blunt lawn mower trauma

    OpenAIRE

    Normand, Camilla; Fostervold, Aasmund; Haarr, Elin; Skontorp, Marie; Berg, ?se

    2015-01-01

    A patient presented with tetanus ten days after blunt trauma with a lawn mower. Our case describes the diagnosis and treatment of this patient with an infectious disease commonly seen in the developing world but rarely seen in the developed world.

  9. Tetanus after blunt lawn mower trauma.

    Science.gov (United States)

    Normand, Camilla; Fostervold, Aasmund; Haarr, Elin; Skontorp, Marie; Berg, Åse

    2015-01-01

    A patient presented with tetanus ten days after blunt trauma with a lawn mower. Our case describes the diagnosis and treatment of this patient with an infectious disease commonly seen in the developing world but rarely seen in the developed world.

  10. Ventricular septal necrosis after blunt chest trauma

    Directory of Open Access Journals (Sweden)

    Alireza Ahmadi

    2012-07-01

    Full Text Available Ventricular Septal Defect (VSD after blunt chest trauma is a very rare traumatic affection.We report here a case of blunt chest injury-related VSD and pseudoaneurysm.A 30-year old male truck driver was referred from a trauma center to our hospital seven days after a blunt chest trauma and rib fracture. The patient had severe pulmonary edemaand echocardiography showed large VSD. Several mechanisms are involved in the pathogenesis of this affection including an acute compression of the heart muscle between the sternum and the spine, leading to excessive changes in the intrathoracic and most likely theintracardiac pressure after blunt chest injury. Traumatical patients with the same symptoms may be at risk of sudden death. Therefore, a high grade of suspicion is mandatory even without solid evidence of myocardial damage on the initial evaluation. In continue somehidden angles of this case was discussed. Given the prognostic implications of traumatic VSD with associated pseudoaneurysm, its detection has critical value for preventing its clinicalsequelae.

  11. OUR EXPERIENCE WITH BLUNT ABDOMINAL TRAUMA

    Directory of Open Access Journals (Sweden)

    Ankareddi Vijaya Lakshmi

    2016-12-01

    Full Text Available BACKGROUND Blunt abdominal trauma is an emergency and is associated with significant morbidity and mortality. The aim of the study is to study incidence, demographic profile, epidemiological factors, mechanism of trauma, treatment modalities, associated injuries, postoperative complications and morbidity and mortality. MATERIALS AND METHODS A retrospective analysis of 72 patients of blunt abdominal trauma who were admitted in government general hospital between May 2013 to April 2015 in Department of General Surgery, Government General Hospital, Guntur, with in a span of 24 months were studied. Demographic data, mechanism of trauma, management and outcome were studied. RESULTS Most of the patients in our study were in the age group of 21-30 years. Spleen was the commonest organ involved and most common procedure performed was splenectomy. Most common extra-abdominal injury was rib fractures. Wound infection was the commonest complication. CONCLUSION Initial resuscitative measures, thorough clinical examination and correct diagnosis forms the vital part of the management. FAST is more useful in blunt abdominal trauma patients who are unstable. X-ray revealed 100% accuracy in hollow viscous perforation in blunt abdominal trauma patients. CT abdomen is more useful in stable patients. Definitive indication for laparotomy was haemodynamic instability and peritonitis. Associated injuries influenced morbidity and mortality. Early diagnosis and prompt treatment can save many lives.

  12. Isolated gallbladder rupture following blunt abdominal injury

    African Journals Online (AJOL)

    2015-05-26

    May 26, 2015 ... Kaohsiung Medical University, Kaohsiung, Taiwan. Abstract. Isolated traumatic gallbladder rupture subsequent to blunt abdominal injury is rare. Most literatures on the subjects consist of case reports. We reported a rare case of isolated gallbladder rupture and discussed the possible predisposing factors to ...

  13. Anterior capsular rupture following blunt ocular injury

    Science.gov (United States)

    Gremida, Anas; Kassem, Iris; Traish, Aisha

    2011-01-01

    Summary A 10-year-old boy suffered a large, oblique anterior capsular tear following blunt injury to his right eye. The boy was followed daily for hyphema resolution and progressive traumatic cataract formation. After the hyphema had resolved, the lens was removed using an anterior approach and an intraocular lens was placed with excellent visual outcome. PMID:23362402

  14. An evidence based blunt trauma protocol

    NARCIS (Netherlands)

    Vugt, R. van; Kool, D.R.; Lubeek, S.F.K.; Dekker, H.M.; Brink, M.; Deunk, J.; Edwards, M.J.R.

    2013-01-01

    OBJECTIVE: Currently CT is rapidly implemented in the evaluation of trauma patients. In anticipation of a large international multicentre trial, this study's aim was to evaluate the clinical feasibility of a new diagnostic protocol, used for the primary radiological evaluation in adult blunt

  15. Complications following blunt and penetrating injuries in 216 victims of chest trauma requiring tube thoracostomy.

    Science.gov (United States)

    Helling, T S; Gyles, N R; Eisenstein, C L; Soracco, C A

    1989-10-01

    Tube thoracostomy (TT) is required in the treatment of many blunt and penetrating injuries of the chest. In addition to complications from the injuries, TT may contribute to morbidity by introducing microorganisms into the pleural space or by incomplete lung expansion and evacuation of pleural blood. We have attempted to assess the impact of TT following penetrating and blunt thoracic trauma by examining a consecutive series of 216 patients seen at two urban trauma centers with such injuries who required TT over a 30-month period. Ninety-four patients suffered blunt chest trauma; 122 patients were victims of penetrating wounds. Patients with blunt injuries had longer ventilator requirements (12.6 +/- 14 days vs. 3.7 +/- 7.1 days, p = 0.003), longer intensive care stays (12.2 +/- 12.5 days vs. 4.1 +/- 7.5 days, p = 0.001), and longer periods of TT, (6.5 +/- 4.9 days vs. 5.2 +/- 4.5 days, p = 0.018). Empyema occurred in six patients (3%). Residual hemothorax was found in 39 patients (18%), seven of whom required decortication. Recurrent pneumothorax developed in 51 patients (24%) and ten required repeat TT. Complications occurred in 78 patients (36%). Patients with blunt trauma experienced more complications (44%) than those with penetrating wounds (30%) (p = 0.04). However, only seven of 13 patients developing empyema or requiring decortication had blunt trauma. Despite longer requirements for mechanical ventilation, intensive care, and intubation, victims of blunt trauma seemed to have effective drainage of their pleural space by TT without increased risk of infectious complications.

  16. Integrating Innovation: Keeping the Leading Edge

    Science.gov (United States)

    2015-08-01

    access inside Army com- mand posts. Commercial innovation also can be built directly into our con- tract structure. Just as today’s smartphones ...moving to publish detailed guidance this year on how gov- ernment and industry partners will comply with the Modular Open Systems Architecture...which outlines design principles and interface characteristics allowing for modular hardware While the Army cannot predict the future or design

  17. The simulation of automated leading edge assembly

    OpenAIRE

    Song, Qingming

    2015-01-01

    Aircraft manufacturers are experiencing a fierce competition worldwide. Improving productivity, increasing throughput and reducing costs are influencing aircraft manufacturer’s future development. In order to improve competitiveness and provide sufficient and high quality products, it should reduce operations of aircraft assembly,majority of which are still in manual process, which limit production output. In contrast, these processes can be automated to replace manual opera...

  18. Leading Edge Aeronautics Research for NASA Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The LEARN Project explores the creation of novel concepts and processes with the potential to create new capabilities in aeronautics research through awards to the...

  19. Computed tomographic diagnosis of the blunt hepatic trauma

    International Nuclear Information System (INIS)

    Suzuki, Masayuki; Takashima, Tsutomu; Funaki, Hiromi; Kanno, Seiichi; Ushitani, Kenji; Tabuchi, Makoto.

    1982-01-01

    In this report, the CT appearances of three cases of the blunt hepatic trauma are presented. The hepatic hematomas are displayed as the poorly demarcated, uneven low density area on plain CT. Post-contrast study makes their margin more clearly. The intrapertioneal hemorrhage is shown as a fluid collection around the liver and/or spleen. As CT is non-invasively and quickly performed, it is useful for the evaluation of the hepatic injury in emergency. The concomitant other organ injuries may be accurately detected by CT. The follow-up study is useful for estimating the therapeutic effect and considering the treatment plan. (author)

  20. Blunt impact as deterrent: human approach-avoidance behaviors and other stress responses studied within a paintball gaming context

    Science.gov (United States)

    Short, Kenneth R.; Bergen, Michael T.; DeMarco, Robert M.; Chua, Florence B.; Servatius, Richard J.

    2006-05-01

    Blunt impact munitions are often used by civilian law enforcement and in military operations on urban terrain (MOUT) missions to dissuade individuals and groups from approaching valued assets. The use of blunt munitions (rubber-ball or sponge) is predicated on their effectiveness as aversive stimuli; the effectiveness is weighed against the risk of serious injury or death. However, little empirical evidence supports effectiveness. Here, we use a paintball gaming context to study the effects of blunt impact on performance and approach behaviors. Volunteers individually traversed a course in which targets offer the opportunity to gain for accuracy. While completing the targeting task, subjects were bombarded with paintballs, which progressively became more numerous and the impact more intense as the subjects neared goal locations. Initial data suggest that over 30 blunt impacts by paintballs delivered at 280 ft/sec over 30 to 100 ft are insufficient to overcome intrinsic and extrinsic approach motivations or impair targeting or advance performance in an overwhelming majority of subjects. Our apparent ceiling effect was surprising. A sub-comparison of the few subjects who stopped the game before the end with those who did not suggests that personality factors influence the effectiveness of blunt impact as a deterrent. While paintballs differ from traditional blunt impact munitions on a number of physical characteristics, impact that was sufficient to repeatedly bruise volunteers was not an effective deterrent.

  1. The effect of dietary folic acid on biochemical parameters and gene expression of three heat shock proteins (HSPs) of blunt snout bream (Megalobrama amblycephala) fingerling under acute high temperature stress.

    Science.gov (United States)

    Sesay, Daniella Fatmata; Habte-Tsion, Habte-Michael; Zhou, Qunlan; Ren, Mingchun; Xie, Jun; Liu, Bo; Chen, Ruli; Pan, Liangkun

    2017-08-01

    The effects of dietary folic acid on biochemical parameters and gene expression of three heat shock proteins (HSPs) of blunt snout bream (Megalobrama amblycephala) fingerling under acute high temperature stress. Six dietary folic acid groups (0.0, 0.5, 1.0, 2.0, 5.0, and 10.0) mg/kg diets were designed and assigned into 18 tanks in three replicates each (300 l/tank) and were administered for 10 weeks in a re-circulated water system. The fingerlings with an initial weight of 27.0 ± 0.03 g were fed with their respective diets four times daily. At the end of the experiment, samples were collected before challenge, 0, 24, 72 h, and 7 days. Serum total protein (TP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), cortisol, glucose, complement C3 (C3), complement C4 (C4, immunoglobulin M (IgM) hepatic superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and the expression of heat shock protein 60 (HSP60), 70 (HSP70), and 90 (HSP90) were studied. The results showed that fish fed with dietary folic acid between 1.0, 2.0, and 5.0 mg/kg significantly (P stress, 0, 24, 72 h, and 7 days significantly (P  0.05) of the three HSPs. However, there were statistical significant interactive effect between dietary folic acid inclusion level and temperature duration on serum C3 and C4 (P  0.05). The present results indicate that supplementation of basal diet from 1.0 mg/kg; 2.0 and 5.0 mg/kg can enhance acute high temperature resistance ability in M. amblycephala fingerling to some degree and improve physiological response, immune and antioxidant capacities, and expression level of three HSPs.

  2. A CLINICAL STUDY ON BLUNT INJURY ABDOMEN

    Directory of Open Access Journals (Sweden)

    G. Kishore Babu

    2016-10-01

    Full Text Available BACKGROUND Abdominal trauma continues to account for a large number of trauma-related injuries and deaths. Motor vehicle accidents and urban violence, respectively, are the leading causes of blunt and penetrating trauma to this area of the body. Unnecessary deaths and complications can be minimized by improved resuscitation, evaluation and treatment. The new techniques and diagnostic tools available are important in the management of abdominal trauma. These improved methods, however, still depend on experience and clinical judgment for application and determination of the best care for the injured patient. The aim of the study is to 1. Analyse the incidence, clinical characteristics, diagnosis, indications for laparotomy, therapeutic methods and morbidity & mortality rates. 2. To study nature of blunt abdominal trauma. 3. To assess patient for surgical intervention and to avoid negative laparotomy. 4. To assess morbidity rate in different organs injury. 5. To evaluate modalities of treatment, complications and prognosis. MATERIALS AND METHODS This study is a prospective study on 97 patients with Blunt injuries to the abdomen admitted in S.V.R.R.G.G. Hospital, Tirupati during October 2013-15. Inclusion Criteria Patients > 13 years, with Blunt injury to abdomen either by RTA, fall, object contact, assault giving written informed consent. Exclusion Criteria Patients <13 yrs. Blunt injuries due to blasts, patients with severe cardiothoracic and head injuries who are hemodynamically unstable. CONCLUSION Blunt Trauma to abdomen is on rise due to excessive use of motor vehicles. It poses a therapeutic and diagnostic dilemma for the attending surgeon due to wide range of clinical manifestations ranging from no early physical findings to progression to shock. So, the Trauma surgeon should rely on his physical findings in association with use of modalities like x-ray abdomen, USG abdomen and abdominal paracentesis. Hollow viscus perforations are

  3. Screening ultrasonography of 2,204 patients with blunt abdominal trauma in the Wenchuan earthquake.

    Science.gov (United States)

    Zhou, Jixiang; Huang, Jiwei; Wu, Hong; Jiang, Hui; Zhang, Heqing; Prasoon, Pankaj; Xu, Yinglong; Bai, Yannan; Qiu, Jianguo; Zeng, Yong

    2012-10-01

    Abdominal injuries constitute a small proportion of all earthquake-related traumas; however, it often resulted in fatal hemorrhage. Ultrasonography has been described as an effective triage tool in the evaluation of blunt abdominal trauma. We aimed to present an overview of the diagnostic accuracy of screening ultrasonography for patients with blunt abdominal trauma admitted to various hospitals during the Wenchuan earthquake in China. We retrospectively analyzed the patients with blunt abdominal trauma who underwent ultrasonography after admission to various hospitals. Ultrasonography findings were considered positive if evidence of free fluid or a parenchymal injury was identified. Ultrasonography findings were compared with the findings of computed tomography, diagnostic peritoneal lavage, repeated ultrasonography, cystography, operation, and/or the clinical course. Findings from 2,204 ultrasonographic examinations were evaluated. Findings of 199 ultrasonographic examinations (9.0%) were considered positive. Of the patients, 12 (0.5%) had a false-negative ultrasonographic findings; of this group, 3 (25%) required exploratory laparotomy. Ultrasonography had a sensitivity of 91.9%, specificity of 96.9%, and an accuracy of 96.6% for detection of abdominal injuries. Positive predictive value was 68.3%, and negative predictive value was 99.4%. Screening ultrasonography is highly reliable in the setting of blunt abdominal trauma after earthquake. It should be used as an initial diagnostic modality in the evaluation of most blunt abdominal trauma. Diagnostic study, level III.

  4. Blunt trauma to the spleen: ultrasonographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Doody, O. [Department of Radiology, Tallaght Hospital, Dublin (Ireland); Lyburn, D. [Department of Radiology, Cheltenham General Hospital (United Kingdom); Geoghegan, T. [Department of Radiology, Tallaght Hospital, Dublin (Ireland); Govender, P. [Department of Radiology, Tallaght Hospital, Dublin (Ireland); Monk, P.M. [Department of Radiology, Vancouver Hospital (Canada); Torreggiani, W.C. [Department of Radiology, Tallaght Hospital, Dublin (Ireland)]. E-mail: william.torreggiani@amnch.ie

    2005-09-01

    The spleen is the most frequently injured organ in adults who sustain blunt abdominal trauma. Splenic trauma accounts for approximately 25% to 30% of all intra-abdominal injuries. The management of splenic injury has undergone rapid change over the last decade, with increasing emphasis on splenic salvage and non-operative management. Identifying the presence and degree of splenic injury is critical in triaging the management of patients. Imaging is integral in the identification of splenic injuries, both at the time of injury and during follow-up. Although CT remains the gold standard in blunt abdominal trauma, US continues to play an important role in assessing the traumatized spleen. This pictorial review illustrates the various ultrasonographic appearances of the traumatized spleen. Correlation with other imaging is presented and complications that occur during follow-up are described.

  5. Predictors of abdominal injuries in blunt trauma.

    Science.gov (United States)

    Farrath, Samiris; Parreira, José Gustavo; Perlingeiro, Jacqueline A G; Solda, Silvia C; Assef, José Cesar

    2012-01-01

    To identify predictors of abdominal injuries in victims of blunt trauma. retrospective analysis of trauma protocols (collected prospectively) of adult victims of blunt trauma in a period of 15 months. Variables were compared between patients with abdominal injuries (AIS>0) detected by computed tomography or/and laparotomy (group I) and others (AIS=0, group II). Student's t, Fisher and qui-square tests were used for statistical analysis, considering p3) in head (18.5% vs. 7.9%), thorax (29.2% vs. 2.4%) and extremities (40.0% vs. 13.7%). The highest odds ratios for the diagnosis of abdominal injuries were associated flail chest (21.8) and pelvic fractures (21.0). Abdominal injuries were more frequently observed in patients with hemodynamic instability, changes in Glasgow coma scale and severe lesions to the head, chest and extremities.

  6. Myocardial contusion following nonfatal blunt chest trauma

    International Nuclear Information System (INIS)

    Kumar, S.A.; Puri, V.K.; Mittal, V.K.; Cortez, J.

    1983-01-01

    Currently available diagnostic techniques for myocardial contusion following blunt chest trauma were evaluated. We investigated 30 patients prospectively over a period of 1 year for the presence of myocardial contusion. Among the 30 patients, eight were found to have myocardial contusion on the basis of abnormal electrocardiograms, elevated creatine phosphokinase MB fraction (CPK-MB), and positive myocardial scan. Myocardial scan was positive in seven of eight patients (87.5%). CPK-MB fraction was elevated in four of eight patients (50%). Definitive electrocardiographic changes were seen in only two of eight patients (25%). It appears that myocardial scan using technetium pyrophosphate and CPK-MB fraction determinations are the most reliable aids in diagnosis of myocardial contusion following blunt chest trauma

  7. Hepatic hydrothorax after blunt chest trauma

    Directory of Open Access Journals (Sweden)

    Shang-Chiung Wang

    2012-08-01

    Full Text Available We report a successful treatment result in a rare case of hepatitis C virus-related cirrhosis, who had sustained hydrothorax after blunt thoracoabdominal trauma. This was a female patient with liver cirrhosis, Child–Turcotte–Pugh class A, without ascites before injury. She sustained blunt thoracoabdominal trauma with a left clavicle fracture dislocation and right rib fractures. There was no hemopneumothorax at initial presentation. However, dyspnea and right pleural effusion developed gradually. We inserted a chest tube to relieve the patient's symptoms, and the daily drainage amount remained consistent. Hepatic hydrothorax was confirmed by the intraperitoneal injection of radioisotope 99mTc-sulfur colloid that demonstrated one-way transdiaphragmatic flow of fluid from the peritoneal cavity to pleural cavities. Finally, the hydrothorax was treated successfully by minocycline-induced pleural symphysis. To the best of our knowledge, this is the first case of hepatic hydrothorax developed after thoracoabdominal trauma.

  8. Blunt traumatic cardiac rupture: therapeutic options and outcomes.

    Science.gov (United States)

    Nan, Yu-Yun; Lu, Ming-Shian; Liu, Kuo-Sheng; Huang, Yao-Kuang; Tsai, Feng-Chun; Chu, Jaw-Ji; Lin, Pyng Jing

    2009-09-01

    Cardiac rupture following blunt thoracic trauma is rarely encountered by clinicians, since it commonly causes death at the scene. With advances in traumatology, blunt cardiac rupture had been increasingly disclosed in various ways. This study reviews our experience of patients with suspected blunt traumatic cardiac rupture and proposes treatment protocols for the same. This is a 5-year retrospective study of trauma patients confirmed with blunt traumatic cardiac rupture admitted to a university-affiliated tertiary trauma referral centre. The following information was collected from the patients: age, sex, mechanism of injury, initial effective diagnostic tool used for diagnosing blunt cardiac rupture, location and size of the cardiac injury, associated injury and injury severity score (ISS), reversed trauma score (RTS), survival probability of trauma and injury severity scoring (TRISS), vital signs and biochemical lab data on arrival at the trauma centre, time elapsed from injury to diagnosis and surgery, surgical details, hospital course and final outcome. The study comprised 8 men and 3 women with a median age of 39 years (range: 24-73 years) and the median follow-up was 5.5 months (range: 1-35 months). The ISS, RTS, and TRISS scores of the patients were 32.18+/-5.7 (range: 25-43), 6.267+/-1.684 (range: 2.628-7.841), and 72.4+/-25.6% (range: 28.6-95.5%), respectively. Cardiac injuries were first detected using focused assessment with sonography for trauma (FAST) in 4 (36.3%) patients, using transthoracic echocardiography in 3 (27.3%) patients, chest CT in 1 (9%) patient, and intra-operatively in 3 (27.3%) patients. The sites of cardiac injury comprised the superior vena cava/right atrium junction (n=4), right atrial auricle (n=1), right ventricle (n=4), left ventricular contusion (n=1), and diffuse endomyocardial dissection over the right and left ventricles (n=1). Notably, 2 had pericardial lacerations presenting as a massive haemothorax, which initially masked

  9. ACR appropriateness criteria blunt chest trauma.

    Science.gov (United States)

    Chung, Jonathan H; Cox, Christian W; Mohammed, Tan-Lucien H; Kirsch, Jacobo; Brown, Kathleen; Dyer, Debra Sue; Ginsburg, Mark E; Heitkamp, Darel E; Kanne, Jeffrey P; Kazerooni, Ella A; Ketai, Loren H; Ravenel, James G; Saleh, Anthony G; Shah, Rakesh D; Steiner, Robert M; Suh, Robert D

    2014-04-01

    Imaging is paramount in the setting of blunt trauma and is now the standard of care at any trauma center. Although anteroposterior radiography has inherent limitations, the ability to acquire a radiograph in the trauma bay with little interruption in clinical survey, monitoring, and treatment, as well as radiography's accepted role in screening for traumatic aortic injury, supports the routine use of chest radiography. Chest CT or CT angiography is the gold-standard routine imaging modality for detecting thoracic injuries caused by blunt trauma. There is disagreement on whether routine chest CT is necessary in all patients with histories of blunt trauma. Ultimately, the frequency and timing of CT chest imaging should be site specific and should depend on the local resources of the trauma center as well as patient status. Ultrasound may be beneficial in the detection of pneumothorax, hemothorax, and pericardial hemorrhage; transesophageal echocardiography is a first-line imaging tool in the setting of suspected cardiac injury. In the blunt trauma setting, MRI and nuclear medicine likely play no role in the acute setting, although these modalities may be helpful as problem-solving tools after initial assessment. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  10. The blunted effect of glucose-dependent insulinotropic polypeptide in subcutaneous abdominal adipose tissue in obese subjects is partly reversed by weight loss

    DEFF Research Database (Denmark)

    Asmar, M; Arngrim, N; Simonsen, L.

    2016-01-01

    BACKGROUND: Glucose-dependent insulinotropic polypeptide (GIP) appears to have impaired effect on subcutaneous abdominal adipose tissue metabolism in obese subjects. The aim of the present study was to examine whether weight loss may reverse the impaired effect of GIP on subcutaneous abdominal...... adipose tissue in obese subjects. METHODS: Five obese males participated in a 12-week weight loss program, which consisted of caloric restriction (800 Cal day(-)(1)) followed by 4 weeks of weight-maintenance diet. Before and after weight loss, subcutaneous adipose tissue lipid metabolism was studied...... after weight loss, Pobese subjects, weight...

  11. Performance of a New Blunt-Tip Coaxial Needle for Percutaneous Biopsy and Drainage of "Hard-To-Reach" Targets.

    Science.gov (United States)

    Cazzato, Roberto Luigi; Garnon, Julien; Shaygi, Behnam; Caudrelier, Jean; Bauones, Salem; Tsoumakidou, Georgia; Koch, Guillaume; Gangi, Afshin

    2017-09-01

    To present a new blunt-tip coaxial needle (SoftGuard) applied to access "hard-to-reach" targets undergoing percutaneous image-guided biopsy or drainage. All consecutive patients presenting between August and December 2016 with "hard-to-reach" (blunt-tip needle is a safe and effective tool when applied as a coaxial working cannula for percutaneous biopsy or drainage of "hard-to-reach" targets.

  12. Surgery as a Double-Edged Sword: A Clinically Feasible Approach to Overcome the Metastasis-Promoting Effects of Surgery by Blunting Stress and Prostaglandin Responses

    International Nuclear Information System (INIS)

    Benish, Marganit; Ben-Eliyahu, Shamgar

    2010-01-01

    Surgery remains an essential therapeutic approach for most solid malignancies, including breast cancer. However, surgery also constitutes a risk factor for promotion of pre-existing micrometastases and the initiation of new metastases through several mechanisms, including the release of prostaglandins and stress hormones (e.g., catecholamines and glucocorticoids). However, the perioperative period also presents an opportunity for cell mediated immunity (CMI) and other mechanisms to eradicate or control minimal residual disease, provided that the deleterious effects of surgery are minimized. Here, we discuss the key role of endogenous stress hormones and prostaglandins in promoting the metastatic process through their direct impact on malignant cells, and through their deleterious impact on anti-cancer CMI. We further discuss the effects of anesthetic techniques, the extent of surgery, pain alleviation, and timing within the menstrual cycle with respect to their impact on tumor recurrence and physiological stress responses. Last, we suggest an attractive perioperative drug regimen, based on a combination of a cyclooxygenase (COX)-2 inhibitor and a β-adrenergic blocker, which we found effective in attenuating immune suppression and the metastasis-promoting effects of surgery in several tumor models. This regimen is clinically applicable, and could potentially promote disease free survival in patients operated for breast and other types of cancer

  13. Surgery as a Double-Edged Sword: A Clinically Feasible Approach to Overcome the Metastasis-Promoting Effects of Surgery by Blunting Stress and Prostaglandin Responses

    Energy Technology Data Exchange (ETDEWEB)

    Benish, Marganit; Ben-Eliyahu, Shamgar, E-mail: shamgar@post.tau.ac.il [Neuroimmunology Research Unit, Department of Psychology, Tel Aviv University, Tel Aviv 69978 (Israel)

    2010-11-24

    Surgery remains an essential therapeutic approach for most solid malignancies, including breast cancer. However, surgery also constitutes a risk factor for promotion of pre-existing micrometastases and the initiation of new metastases through several mechanisms, including the release of prostaglandins and stress hormones (e.g., catecholamines and glucocorticoids). However, the perioperative period also presents an opportunity for cell mediated immunity (CMI) and other mechanisms to eradicate or control minimal residual disease, provided that the deleterious effects of surgery are minimized. Here, we discuss the key role of endogenous stress hormones and prostaglandins in promoting the metastatic process through their direct impact on malignant cells, and through their deleterious impact on anti-cancer CMI. We further discuss the effects of anesthetic techniques, the extent of surgery, pain alleviation, and timing within the menstrual cycle with respect to their impact on tumor recurrence and physiological stress responses. Last, we suggest an attractive perioperative drug regimen, based on a combination of a cyclooxygenase (COX)-2 inhibitor and a β-adrenergic blocker, which we found effective in attenuating immune suppression and the metastasis-promoting effects of surgery in several tumor models. This regimen is clinically applicable, and could potentially promote disease free survival in patients operated for breast and other types of cancer.

  14. Transcatheter Treatment of Liver Laceration from Blunt Trauma

    OpenAIRE

    Hardy, Andrew Hal; Phan, Ho; Khanna, Pavan; Nolan, Timothy; Dong, Paul

    2012-01-01

    Blunt hepatic trauma is a fairly common pathology seen in trauma centers. We describe a pediatric patient who suffered blunt hepatic trauma that was managed successfully with a combination of exploratory laparotomy and liver packing, followed by hepatic artery embolization by interventional radiology (IR) after he continued to have significant arterial extravasation. Also discussed are trends in overall blunt hepatic trauma management and the technique of IR management.

  15. Kuula. Kellele ei meeldiks James Blunt? / Mart Juur

    Index Scriptorium Estoniae

    Juur, Mart, 1964-

    2007-01-01

    Heliplaatidest: James Blunt "Back To Bedlam", Enrique Iglesias "Insomniac", Prince "Planet Earth", Garbage "Absolut Garbage", Justice "Cross", Interpol "Our Love To Admire", Rufus Wainwright "Release The Stars"

  16. Stability and sensitivity analysis of hypersonic flow past a blunt cone

    Science.gov (United States)

    Nichols, Joseph W.; Cook, David; Brock, Joseph M.; Candler, Graham V.

    2017-11-01

    We investigate the effects of nosetip bluntness and low-level distributed roughness on instabilities leading to transition on a 7 degree half-angle blunt cone at Mach 10. To study the sensitivity of boundary layer instabilities to bluntness and roughness, we numerically extract Jacobian matrices directly from the unstructured hypersonic flow solver US3D. These matrices govern the dynamics of small perturbations about otherwise laminar base flows. We consider the frequency response of the resulting linearized dynamical system between different input and output locations along the cone, including close to the nosetip. Using adjoints, our method faithfully captures effects of complex geometry such as strong curvature and roughness that lead to flow acceleration and localized heating in this region. These effects violate the assumption of a slowly-varying base flow that underpins traditional linear stability analyses. We compare our results, which do not rely upon this assumption, to experimental measurements of a Mach 10 blunt cone taken at the AEDC Hypervelocity Ballistic Range G facility. In particular, we assess whether effects of complex geometry can explain discrepancies previously noted between traditional stability analysis and observations. This work is supported by the Office of Naval Research through Grant Number N00014-17-1-2496.

  17. Wind Tunnel and Numerical Analysis of Thick Blunt Trailing Edge Airfoils

    Science.gov (United States)

    McLennan, Anthony William

    Two-dimensional aerodynamic characteristics of several thick blunt trailing edge airfoils are presented. These airfoils are not only directly applicable to the root section of wind turbine blades, where they provide the required structural strength at a fraction of the material and weight of an equivalent sharp trailing edge airfoil, but are also applicable to the root sections of UAVs having high aspect ratios, that also encounter heavy root bending forces. The Reynolds averaged Navier-Stokes code, ARC2D, was the primary numerical tool used to analyze each airfoil. The UCD-38-095, referred to as the Pareto B airfoil in this thesis, was also tested in the University of California, Davis Aeronautical Wind Tunnel. The Pareto B has an experimentally determined maximum lift coefficient of 1.64 at 14 degrees incidence, minimum drag coefficient of 0.0385, and maximum lift over drag ratio of 35.9 at a lift coefficient of 1.38, 10 degrees incidence at a Reynolds number of 666,000. Zig-zag tape at 2% and 5% of the chord was placed on the leading edge pressure and suction side of the Pareto B model in order to determine the aerodynamic performance characteristics at turbulent flow conditions. Experimental Pareto B wind tunnel data and previous FB-3500-0875 data is also presented and used to validate the ARC2D results obtained in this study. Additionally MBFLO, a detached eddy simulation Navier-Stokes code, was used to analyze the Pareto B airfoil for comparison and validation purposes.

  18. Blunt splenic trauma: Assessment, management and outcomes.

    Science.gov (United States)

    El-Matbouly, Moamena; Jabbour, Gaby; El-Menyar, Ayman; Peralta, Ruben; Abdelrahman, Husham; Zarour, Ahmad; Al-Hassani, Ammar; Al-Thani, Hassan

    2016-02-01

    The approach for diagnosis and management of blunt splenic injury (BSI) has been considerably shifted towards non-operative management (NOM). We aimed to review the current practice for the evaluation, diagnosis and management of BSI. A traditional narrative literature review was carried out using PubMed, MEDLINE and Google scholar search engines. We used the keywords "Traumatic Splenic injury", "Blunt splenic trauma", "management" between December 1954 and November 2014. Most of the current guidelines support the NOM or minimally approaches in hemodynamically stable patients. Improvement in the diagnostic modalities guide the surgeons to decide the timely management pathway Though, there is an increasing shift from operative management (OM) to NOM of BSI; NOM of high grade injury is associated with a greater rate of failure, prolonged hospital stay, risk of delayed hemorrhage and transfusion-associated infections. Some cases with high grade BSI could be successfully treated conservatively, if clinically feasible, while some patients with lower grade injury might end-up with delayed splenic rupture. Therefore, the selection of treatment modalities for BSI should be governed by patient clinical presentation, surgeon's experience in addition to radiographic findings. About one-fourth of the blunt abdominal trauma accounted for BSI. A high index of clinical suspicion along with radiological diagnosis helps to identify and characterize splenic injuries with high accuracy and is useful for timely decision-making to choose between OM or NOM. Careful selection of NOM is associated with high success rate with a lower rate of morbidity and mortality. Copyright © 2015 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  19. Higher incidence of major complications after splenic embolization for blunt splenic injuries in elderly patients.

    Science.gov (United States)

    Wu, Shih-Chi; Fu, Chih-Yuan; Chen, Ray-Jade; Chen, Yung-Fang; Wang, Yu-Chun; Chung, Ping-Kuei; Yu, Shu-Fen; Tung, Cheng-Cheng; Lee, Kun-Hua

    2011-02-01

    Nonoperative management (NOM) of blunt splenic injuries has been widely accepted, and the application of splenic artery embolization (SAE) has become an effective adjunct to NOM. However, complications do occur after SAE. In this study, we assess the factors leading to the major complications associated with SAE. Focusing on the major complications after SAE, we retrospectively studied patients who received SAE and were admitted to 2 major referral trauma centers under the same established algorithm for management of blunt splenic injuries. The demographics, angiographic findings, and factors for major complications after SAE were examined. Major complications were considered to be direct adverse effects arising from SAE that were potentially fatal or were capable of causing disability. There were a total of 261 patients with blunt splenic injuries in this study. Of the 261 patients, 53 underwent SAE, 11 (21%) of whom were noted to have 12 major complications: 8 cases of postprocedural bleeding, 2 cases of total infarction, 1 case of splenic abscess, and 1 case of splenic atrophy. Patients older than 65 years were more susceptible to major complications after SAE. Splenic artery embolization is considered an effective adjunct to NOM in patients with blunt splenic injuries. However, risks of major complications do exist, and being elderly is, in part, associated with a higher major complication incidence. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Transdiaphragmatic Intercostal Herniation following Blunt Trauma

    Directory of Open Access Journals (Sweden)

    Debkumar Sarkar

    2012-01-01

    Full Text Available Intercostal herniation is very rarely and sporadically reported in the literature. Intercostal hernia can occur following blunt trauma and may be associated with rib fractures. We present a case of a patient who presented with rib fractures, diaphragmatic rupture, and intrathoracic herniation of abdominal contents with subsequent herniation of both lung and abdominal contents through an intercostal defect. The patient was successfully treated with primary surgical repair of the diaphragm and intercostal hernia. The presentation, pathophysiology, and management of this rare clinical entity are discussed.

  1. Atrioventricular Dissociation following Blunt Chest Trauma

    Directory of Open Access Journals (Sweden)

    Salim Surani

    2014-01-01

    Full Text Available Blunt chest trauma (BCT is a common clinical presentation seen in emergency departments. Few cases of cardiac conduction abnormalities due to BCT have been reported in the medical literature. This dysrhythmias may present as permanent conduction defects requiring permanent pacemaker or may have temporary conduction abnormalities requiring temporary pacemaker or supportive care. We present the case of a young woman who suffered from BCT after being kicked by a horse with the development of a significant substernal hematoma. She developed temporary atrioventricular block, which was completely resolved with the decrease in the size of the substernal hematoma suffered.

  2. Fatigue crack growth from blunt notches

    International Nuclear Information System (INIS)

    Rhodes, D.

    1982-01-01

    A number of methods have been proposed, by which the formation and early growth of fatigue cracks at blunt notches may be predicted. In this report, four methods are compared - i.e. analysis of the crack tip plastic deformation, the cyclic contour integral, δJ, the strain in a critical volume of material, and the notch root plastic strain range. It is shown that these approaches have fundamental elements in common, and that all are compatable with linear elastic fracture mechanics. Early results from a continuing experimental programme are reported. (orig.) [de

  3. CT of blunt hepatic trauma in children

    International Nuclear Information System (INIS)

    Nishiguchi, Hiroyasu; Shimizu, Toshihisa; Omura, Makoto; Nishio, Yoshinori; Watanabe, Shinsuke.

    1991-01-01

    CT findings of blunt hepatic trauma were studied in 27 children. Liver injury was classified into 3 types from mild to severe. Liver contusion was observed in 1, liver laceration in 21, and liver rupture in 5. Only 2 patients (7.4%) required surgery, and the others could be managed by conservative therapy. CT, which accurately reveals not only the severity of liver injury but also injuries of other abdominal organs and intraperitoneal bleeding, is important for the diagnosis of liver injury and determination of its treatment. (author)

  4. CT of blunt chest trauma in children

    International Nuclear Information System (INIS)

    Manson, D.; Babyn, P.S.; Palder, S.; Bergmann, K.

    1993-01-01

    While trauma is still the leading cause of death in the pediatric age range, it is surprising how little the CT appearances of pediatric chest injury have been investigated in the literature. We have reviewed the CT findings of blunt chest trauma in 44 children for whom chest CT examinations were requested to investigate the extent of intrathoracic injury. We noted a propensity for pulmonary contusions to be located posteriorly or posteromedially, and for them to be anatomically nonsegmental and crescentic in shape. This is possibly attributable to the relatively compliant anterior chest wall in children. The CT appearances of other major thoracic injuries are described, including pulmonary lacerations, pneumothoraces, malpositioned chest tubes, mediastinal hematomas, aortic injury, tracheobronchial injury, hemopericardium, and spinal injuries with paraspinal fluid collections. Children demonstrating findings incidental to the actual injury yet important to the subsequent therapy are also presented. We conclude that, in the event of clinically significant blunt chest trauma, the single supine chest examination in the trauma room is insufficient to adequately identify the extent of intrathoracic injury. With the exception of concern for aortic injury for which aortography is indicated, a dynamically enhanced CT scan of the thorax should be performed as clinically significant findings may result in altered therapy. (orig.)

  5. Multiple subfailures characterize blunt aortic injury.

    Science.gov (United States)

    Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A; Brasel, Karen J

    2007-05-01

    Blunt aortic injuries result from rapid deceleration of the thorax as may occur during automotive impacts and falls from extreme heights. Pathological findings can range from failure of specific vessel layers to immediate vessel wall rupture. The purpose of this investigation was to determine the sequence of local structural events that may lead to aortic wall disruption. Fourteen porcine aorta specimens were opened to expose the intima and longitudinally distracted until rupture. Longitudinal mechanics were quantified and subfailures were identified. Histology was used to examine internal layer subfailure. Videography demonstrated that subfailures propagated into complete vessel wall rupture. Subfailures occurred before complete vessel rupture in 93% of specimens. Intimal and medial subfailures were present at 74% of the stress and 82% of the strain to rupture. Multiple subfailures were evident in 79% of specimens. Present results supported the clinical theory that nonimmediate death as a result of blunt aortic injury is commonly caused by propagation of lesser lesions, initiating on the intimal layer, into complete vessel rupture including the adventitial layer. This finding, along with histologic evidence of subfailure pathological findings, confirms the presence of an acute window during which recognition and initiation of permissive hypotension may be lifesaving.

  6. Role of CT in blunt hepatic injury

    International Nuclear Information System (INIS)

    Park, Hyun Joo; Yang, Dal Mo; Kang, Sook Wook; Kim, Hyung Sik; Chung, Hyo Sun; Lee, Young Seok

    1994-01-01

    The aim of this study was to determine the role of the CT scan in blunt hepatic injury and the significance of CT degree of hepatic injury in the decision making of treatment plan. We retrospectively analyzed the CT findings of 22 patients with hepatic injury. We graded hepatic injury on CT scan into five according to the severity. Clinical records, type of management and clinical outcome of the patients were also reviewed. Of the 22 patients, 17 had conservative treatment and five had surgery. The numbers of patients treated conservatively were 0, 4, 11, 2 and 0 in the grade 1, 2, 3, 4, and 5, retrospectively and the numbers of surgically treated cases were 0, 0, 3, 2 and 0 respectively. There was no significant statistical difference between surgically and conservatively treated groups(p-value > 0.05). All patients with conservatively treated group were hemodynamically stable and had no complication during hospitalization. Hemoperitoneum was observed in 11 of 22 patients. In blunt hepatic injury, CT plays an important role in the demonstration of location and extent of the hepatic injury, size of hemoperitoneum and the post operative course. However, we believe that physiologic status of the patients may be more important than the extent of CT based hepatic injury for determining a mode of treatment

  7. Evidence-Based Management and Controversies in Blunt Splenic Trauma

    NARCIS (Netherlands)

    Olthof, D. C.; van der Vlies, C. H.; Goslings, J. C.

    2017-01-01

    The study aims to describe the evidence-based management and controversies in blunt splenic trauma. A shift from operative management to non-operative management (NOM) has occurred over the past decades where NOM has now become the standard of care in haemodynamically stable patients with blunt

  8. Acquired ventricular septal defect: A rare sequel of blunt chest ...

    African Journals Online (AJOL)

    Ventricular septal defect (VSD) is the most common congenital cardiac lesion encountered worldwide. Only very rarely is it acquired, and causation through blunt injury in a child is extremely rare. A previously healthy 7‑year‑old boy suffered blunt chest trauma while at play. He presented 11 days later with features of acute ...

  9. VALIDITY OF PARACENTESIS IN DIAGNOSING BLUNT TRAUMA ABDOMEN

    Directory of Open Access Journals (Sweden)

    Fahad Bin Abdul Majeed

    2017-03-01

    Full Text Available BACKGROUND Blunt abdominal trauma is a common case that comes to an emergency department and it is the most easily missed diagnosis resulting in catastrophic consequences. Delay in diagnosing a case is due to the nonspecific character of the symptoms with which it presents. Clinical signs that could be elicited in blunt trauma abdomen are equally nonspecific. Thus, to avoid delay and save the life of the patient, a doctor has to depend on various investigations to rule out blunt trauma abdomen. The modalities which help include paracentesis, diagnostic peritoneal lavage, Focused Abdominal Sonography for Trauma (FAST and ContrastEnhanced Computed Tomography (CECT. To choose the right investigation for the right patient helps in saving precious lives. Validity of each investigation, availability, condition of the patient are the main points to look into before deciding on the right investigative modality. Paracentesis is the simplest investigation that could be done in emergency department and also at the site of accident to triage the patient. Paracentesis has low sensitivity to detect blunt trauma. FAST is a better investigation with higher validity rates than paracentesis. This study aims to validate paracentesis, which is the simplest and commonest investigation used to identify blunt abdominal trauma. MATERIALS AND METHODS In this study, 106 patients who fulfilled the inclusion and exclusion criteria were followed up by detailed history, clinical examination, paracentesis and FAST to identify blunt abdominal trauma and then compared with a gold standard investigation, which was assigned as CECT for haemodynamically stable patients and laparotomy for haemodynamically unstable patients. Commonest organs injured in blunt trauma and their management was noted. Patients were followed up till discharge or death. Subsequently, the data were compiled using excel sheet and evaluated using tables and charts. RESULTS Paracentesis is found to have a

  10. Study of microstructure and fracture properties of blunt notched and sharp cracked high density polyethylene specimens.

    Science.gov (United States)

    Pan, Huanyu; Devasahayam, Sheila; Bandyopadhyay, Sri

    2017-07-21

    This paper examines the effect of a broad range of crosshead speed (0.05 to 100 mm/min) and a small range of temperature (25 °C and 45 °C) on the failure behaviour of high density polyethylene (HDPE) specimens containing a) standard size blunt notch and b) standard size blunt notch plus small sharp crack - all tested in air. It was observed that the yield stress properties showed linear increase with the natural logarithm of strain rate. The stress intensity factors under blunt notch and sharp crack conditions also increased linearly with natural logarithm of the crosshead speed. The results indicate that in the practical temperature range of 25 °C and 45 °C under normal atmosphere and increasing strain rates, HDPE specimens with both blunt notches and sharp cracks possess superior fracture properties. SEM microstructure studies of fracture surfaces showed craze initiation mechanisms at lower strain rate, whilst at higher strain rates there is evidence of dimple patterns absorbing the strain energy and creating plastic deformation. The stress intensity factor and the yield strength were higher at 25 °C compared to those at 45 °C.

  11. Pneumomediastinum in Blunt Chest Trauma: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Gregory Mansella

    2014-01-01

    Full Text Available Blunt trauma is the most common mechanism of injury in patients with pneumomediastinum and may occur in up to 10% of patients with severe blunt thoracic and cervical trauma. In this case report we present a 24-year-old man with pneumomediastinum due to blunt chest trauma after jumping from a bridge into a river. He complained of persistent retrosternal pain with exacerbation during deep inspiration. Physical examination showed only a slight tenderness of the sternum and the extended Focused Assessment with Sonography for Trauma (e-FAST was normal. Pneumomediastinum was suspected by chest X-ray and confirmed by computed tomography, which showed a lung contusion as probable cause of the pneumomediastinum due to the “Mackling effect.” Sonographic findings consistent with pneumomediastinum, like the “air gap” sign, are helpful for quick bedside diagnosis, but the diagnostic criteria are not yet as well established as for pneumothorax. This present case shows that despite minimal findings in physical examination and a normal e-FAST a pneumomediastinum is still possible in a patient with chest pain after blunt chest trauma. Therefore, pneumomediastinum should always be considered to prevent missing major aerodigestive injuries, which can be associated with a high mortality rate.

  12. Effect of nose bluntness and afterbody shape on aerodynamic characteristics of a monoplanar missile concept with bodies of circular and elliptical cross sections at a Mach number of 2.50

    Science.gov (United States)

    Graves, E. B.; Fournier, R. H.

    1979-01-01

    The tests were performed at a Mach number of 2.50 and at angles of attack from about -4 deg to 32 deg. The results indicate that increasing nose bluntness increases zero lift drag and decreases both the maximum lift-drag ratio and the level of directional stability. The center of pressure generally moves forward with increasing nose size; however, small nose radii on the modified elliptical configurations move the center of pressure rearward. The circular bodied configurations exhibit the greatest longitudinal stability and the least directional stability. Concepts with the variable geometry afterbody contour display the most directional stability and the greatest zero lift drag.

  13. Gastrointestinal Injuries in Blunt Abdominal Traumas.

    Science.gov (United States)

    Gönüllü, D; Ilgun, S; Gedik, M L; Demiray, O; Öner, Z; Er, M; Köksoy, F N

    2015-01-01

    To discuss the efficiency of RTS (Revised TraumaScore), ISS (Injury Severity Score), and factors that affect mortality and morbidity in gastrointestinal injuries due to blunt trauma.Method and methods: Patients with gastrointestinal injuries due to blunt trauma operated within the last six years have been studied retrospectively in terms of demographics,injury mechanism and localization, additional injuries, RTS and ISS, operative technique, morbidity, mortality and duration of hospitalization. Of the eighteen cases, cause of injury was a traffic accident for 11 (61.1%), fall from height for 5 (27%) and physical attack for 2 (11%). Among the eighteen patients,there were 21 gastrointestinal injuries (11 intestinal, 6 colon,3 duodenum, 1 stomach). 10 (55.6%) had additional intraabdominal injuries while the number for extra-abdominal injuries were 12 (66.7%). Primary suture (10), segmentary resection (9) and pyloric exclusion (2) were the operations performed for the twenty-one gastrointestinal injuries.Although statistically not significant, 13(72.2%) patients with additional injuries compared with 5 (27.8%) patients with isolated gastrointestinal injuries, were found to have lower RTS (7.087/7.841), higher ISS (19.4/12.2), longer duration of hospitalization (11.5/8.4 day) as well as higher morbidity (7/1) and mortality (2/0) rates. Comparing the RTS (7.059/7.490) of patients who have and have not developed morbidity revealed no significant difference.However, ISS (23.9/12.2) was significantly higher in patients who have developed morbidity (p=0.003). RTS (6.085 7.445) and ISS (39.5/14.6) of patients who have survived were significantly different than patients who have not(p=0.037 and p=0.023, respectively) Additional injuries in patients with gastrointestinal injury due blunt abdominal traumas increases, although not significantly, morbidity, mortality and duration of hospitalization even when operated early. High ISS is significantly related to the risk of both

  14. Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma.

    Science.gov (United States)

    Stengel, Dirk; Rademacher, Grit; Ekkernkamp, Axel; Güthoff, Claas; Mutze, Sven

    2015-09-14

    Ultrasonography (performed by means of a four-quadrant, focused assessment of sonography for trauma (FAST)) is regarded as a key instrument for the initial assessment of patients with suspected blunt abdominal and thoraco-abdominal trauma in the emergency department setting. FAST has a high specificity but low sensitivity in detecting and excluding visceral injuries. Proponents of FAST argue that ultrasound-based clinical pathways enhance the speed of primary trauma assessment, reduce the number of unnecessary multi-detector computed tomography (MDCT) scans, and enable quicker triage to surgical and non-surgical care. Given the proven accuracy, increasing availability of, and indication for, MDCT among patients with blunt abdominal and multiple injuries, we aimed to compile the best available evidence of the use of FAST-based assessment compared with other primary trauma assessment protocols. To assess the effects of diagnostic algorithms using ultrasonography including in FAST examinations in the emergency department in relation to the early, late, and overall mortality of patients with suspected blunt abdominal trauma. The most recent search was run on 30th June 2015. We searched the Cochrane Injuries Group Specialised Register, The Cochrane Library, MEDLINE (OvidSP), EMBASE (OvidSP), ISI Web of Science (SCI-EXPANDED, SSCI, CPCI-S, and CPSI-SSH), clinical trials registers, and screened reference lists. Trial authors were contacted for further information and individual patient data. We included randomised controlled trials (RCTs). Participants were patients with blunt torso, abdominal, or multiple trauma undergoing diagnostic investigations for abdominal organ injury. The intervention was diagnostic algorithms comprising emergency ultrasonography (US). The control was diagnostic algorithms without US examinations (for example, primary computed tomography (CT) or diagnostic peritoneal lavage (DPL)). Outcomes were mortality, use of CT or invasive procedures (DPL

  15. Aerothermodynamic shape optimization of hypersonic blunt bodies

    Science.gov (United States)

    Eyi, Sinan; Yumuşak, Mine

    2015-07-01

    The aim of this study is to develop a reliable and efficient design tool that can be used in hypersonic flows. The flow analysis is based on the axisymmetric Euler/Navier-Stokes and finite-rate chemical reaction equations. The equations are coupled simultaneously and solved implicitly using Newton's method. The Jacobian matrix is evaluated analytically. A gradient-based numerical optimization is used. The adjoint method is utilized for sensitivity calculations. The objective of the design is to generate a hypersonic blunt geometry that produces the minimum drag with low aerodynamic heating. Bezier curves are used for geometry parameterization. The performances of the design optimization method are demonstrated for different hypersonic flow conditions.

  16. Primary nasal tuberculosis following blunt trauma nose

    Directory of Open Access Journals (Sweden)

    Kaushik Saha

    2014-01-01

    Full Text Available Primary nasal tuberculosis is a rare disease with nearly 40 cases reported. Our patient was a young male presented with left sided nasal obstruction, anosmia and occasional epistaxis for last 7 weeks after 6 months of blunt trauma nose. Contrast enhanced computed tomography of the para nasal sinuses showed increased soft-tissue density with contrast enhancement in the left maxillary antrum with extension through left osteomeatal foramen to the left nasal cavity along with further extension through choana to nasopharynx resulting in partial obliteration of the nasopharyngeal airway. Nasal endoscopy revealed a sessile polypoidal pinkish mass arising from the left osteomeatal foramen. Histopathological examination of excisional biopsy of that area showed caseating granuloma. Our patient diagnosed as primary nasal tuberculosis following trauma and treated with anti-tubercular chemotherapy.

  17. Laparoscopic Splenectomy in Hemodynamically Stable Blunt Trauma.

    Science.gov (United States)

    Huang, Gregory S; Chance, Elisha A; Hileman, Barbara M; Emerick, Eric S; Gianetti, Emily A

    2017-01-01

    No criteria define indications for laparoscopic splenectomy in trauma. This investigation compared characteristics of trauma patients and outcomes between laparoscopic and open splenectomies. Patients were identified retrospectively by using ICD-9 codes. Included patients were 18 or older, with a blunt splenic injury from January 1, 2011, through December 31, 2014, and required splenectomy. Excluded patients had penetrating trauma, successful nonoperative management, or successful embolization. Variables included demographics, presenting characteristics, injury severity scores, abdominal abbreviated injury scores, splenic injury grade, surgical indication and approach (open or laparoscopic), surgery length, intra-operative blood loss, transfusions, length of stay, complications, mortality, and discharge disposition. Forty-one patients underwent open splenectomy, and 11 underwent laparoscopic splenectomy. The mean age was 48.7 years, and men comprised the sample majority (36/52). The groups were well matched for age, abdominal injury scores, and admission vital signs. The open group had a significantly lower level of consciousness and more acidosis compared with the laparoscopic group. Most laparoscopic splenectomies were performed after failed nonoperative management or embolization. The indications for open splenectomy were a positive focused assessment with sonography for trauma and computed tomography results. Laparoscopic patients had significantly longer times between presentation and surgery and longer operations, but had significantly less blood loss and fewer transfusions compared with the open group. There were no differences in mortality, length of stay, complications, or discharge dispositions. Laparoscopic splenectomy is useful in patients with blunt trauma in whom conservative management produced no improvement and who do not have other injuries to preclude laparoscopy.

  18. CT diagnosis of blunt laryngeal trauma

    International Nuclear Information System (INIS)

    Kong Fanbin; Xia Ruigan; Hu Libin

    2000-01-01

    Objective: To analyze CT findings of blunt laryngeal trauma (BLT) and evaluate the value of CT in the diagnosis of BLT. Methods: CT diagnosis and treatment of 16 patients with BLT were reviewed. Results: Soft-tissue injuries were detected in five cases including swelling of the aryepiglottic folds, the false or true vocal cords and airway narrowing in four, and left cricoarytenoid dislocation and card paralysis in one. Supraglottic injuries in two cases including c fractures of the epiglottis in 2 and associated with a laceration of the aryepiglottic folds and the hypopharynx. Glottic injuries in four cases including ventricle fracture of the right thyroid ala in one and midline ventricle or comminute fractures of the thyroid cartilage in three, a square segment of cartilage was depressed into the larynx, and the true vocal cords and the anterior commissure were disrupted in one of this series. Subglottic injuries in five cases including cricoid ring fracture on the opposite side following a lateral force in one, with the fragment depressed into the larynx. Two showed marked comminution of the cricoid ring. Midline vertical fracture of the posterior cricoid plate associated with the laceration of the first tracheal ring in one, and one presented marked disruption of the right cricothyroid joint. Conclusion: CT clearly shows the extent of cartilaginous injury and displacement, related soft-tissue changes and the degree of resulting airway encroachment, and it may be successfully used to determine the need for open exploration and repair in selected cases of blunt trauma to the larynx

  19. Characterizing substance use and mental health profiles of cigar, blunt, and non-blunt marijuana users from the National Survey of Drug Use and Health.

    Science.gov (United States)

    Cohn, Amy; Johnson, Amanda; Ehlke, Sarah; Villanti, Andrea C

    2016-03-01

    Smoking marijuana in a cigar (blunt use) is gaining popularity in the U.S. Research suggests that blunt users differ from exclusive cigar or marijuana users on a variety of demographic and substance use factors. Misreporting of blunts and cigars is also common, particularly among young people, and may lead to inaccurate prevalence estimates. To determine subtype differences, this study investigated the prevalence and demographic, mental health, and substance use correlates of four mutually-exclusive groups of blunt, cigar, and marijuana past 30-day users (cigar-only, blunt-only, non-blunt marijuana, or dual cigar-blunt). Data were analyzed from the 2013 National Survey of Drug Use and Health. In weighted multinomial logistic regression models, respondents who were younger, Black, and who had used tobacco, alcohol, or other drugs in the past 30-days had the highest odds of reporting blunt-only or dual cigar-blunt use. Those reporting blunt-only and dual cigar-blunt use also endorsed a greater number of marijuana and alcohol use disorder symptoms compared to those reporting cigar-only and non-blunt marijuana use. Lower marijuana risk perceptions were associated with increased odds of marijuana use with or without blunts. Major depressive episode was uniquely associated with non-blunt marijuana use. With respect to misclassifiers, respondents who reported past 30-day blunt use but not past 30-day marijuana use were younger, Black, female, and had lower education and income. Those who report blunt-only and dual cigar-blunt use showed the most severe risk profiles. Communicating health consequences and risks of blunt use should be directed toward specific subgroups. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Preliminary evidence that exercise dependence is associated with blunted cardiac and cortisol reactions to acute psychological stress.

    Science.gov (United States)

    Heaney, Jennifer L J; Ginty, Annie T; Carroll, Douglas; Phillips, Anna C

    2011-02-01

    Low or blunted cardiovascular and cortisol reactions to acute psychological stress have been shown to characterise those with a tobacco or alcohol dependency. The present study tested the hypothesis that exercise dependency would be similarly associated with blunted reactivity. Young female exercisers (N=219) were screened by questionnaire for exercise dependence. Ten women with probable exercise dependence and 10 non dependent controls were selected for laboratory stress testing. Cardiovascular activity and salivary cortisol were measured at rest and in response to a 10-min mental arithmetic stress task. The exercise dependent women showed blunted cardiac reactions to the stress task and blunted cortisol at 10, 20, and 30 minute post stress exposure. These effects could not be accounted for in terms of group differences in stress task performance, nor could the cardiac effects be attributed to group differences in cardio-respiratory fitness. It would seem that low stress reactivity is characteristic of a wide range of dependencies, and is not confined to substance dependence. Our results offer further support for the hypothesis that blunted stress reactivity may be a peripheral marker of a central motivational dysregulation. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Posttraumatic True Aneurysm of the Axillary Artery Following Blunt Trauma

    Directory of Open Access Journals (Sweden)

    Tugrul Goncu

    2010-01-01

    Full Text Available The majority of the axillary artery aneurysm cases arise as pseudoaneurysms secondary to blunt or iatrogenic trauma. Isolated traumatic true axillary artery aneurysm is a relatively unusual disorder and generally occurs with repetitive blunt trauma. A 22-year-old female patient with distal axillary artery true aneurysm due to simple blunt axillothoracic trauma is presented. The aneurysm was excised with subpectoral-axillary approach and saphenous vein graft interposition was applied. Long-term follow-up with the patient was uneventful.

  2. Base Deficit as an Indicator of Significant Blunt Abdominal Trauma

    African Journals Online (AJOL)

    multiruka1

    important cause of morbidity and mortality among trauma patients. ... the use of BD as an indicator of significant BAT. Methods: ... Key words: Base deficit, Blunt abdominal trauma,. Predictor. ..... Delineate Risk for Torso Injury in Stable Patients.

  3. Blunt chest trauma: bony injury in the thorax.

    Science.gov (United States)

    Zreik, Nasri H; Francis, Irene; Ray, Arun; Rogers, Benedict A; Ricketts, David M

    2016-02-01

    The management of blunt chest trauma is an evolving concept with no clear current guidelines. This article explores the bony injuries associated with this, focusing on rib fractures and flail segments and the themes around investigation and best management.

  4. Pectus excavatum in blunt chest trauma: a case report

    Directory of Open Access Journals (Sweden)

    Liodakis Emmanouil

    2013-01-01

    Full Text Available Abstract Introduction Blunt cardiac rupture is an exceedingly rare injury. Case presentation We report a case of blunt cardiac trauma in a 43-year-old Caucasian German mother with pectus excavatum who presented after a car accident in which she had been sitting in the front seat holding her two-year-old boy in her arms. The mother was awake and alert during the initial two hours after the accident but then proceeded to hemodynamically collapse. The child did not sustain any severe injuries. Intraoperatively, a combined one-cm laceration of the left atrium and right ventricle was found. Conclusion Patients with pectus excavatum have an increased risk for cardiac rupture after blunt chest trauma because of compression between the sternum and spine. Therefore, patients with pectus excavatum and blunt chest trauma should be admitted to a Level I Trauma Center with a high degree of suspicion.

  5. Factors for failure of nonoperative management of blunt ...

    African Journals Online (AJOL)

    Factors for failure of nonoperative management of blunt hepatosplenic trauma in children. ... Annals of Pediatric Surgery ... However, other than hemodynamic instability, the other factors mentioned above deserve further evaluation to ...

  6. Pneumothorax and subcutaneous emphysema secondary to blunt chest injury

    OpenAIRE

    Porhomayon, Jahan; Doerr, Ralph

    2011-01-01

    This is the case of a patient with a history of blunt chest trauma associated with subcutaneous emphysema and pneumothorax. The patient complained of inspiratory stridor on presentation. Anatomical relationships can explain the pathophysiological process.

  7. Isolated gallbladder injury in a case of blunt abdominal trauma.

    Science.gov (United States)

    Birn, Jeffrey; Jung, Melissa; Dearing, Mark

    2012-04-01

    The diagnosis of blunt injury to the gallbladder may constitute a significant challenge to the diagnostician. There is often a delay in presentation with non-specific clinical symptoms. In the absence of reliable clinical symptoms, diagnostic imaging becomes an invaluable tool in the rapid identification of gallbladder injury. We present a case of isolated gallbladder injury following blunt abdominal trauma which was diagnosed by computed tomography and subsequently confirmed by cholecystectomy.

  8. Isolated Gallbladder Injury in a Case of Blunt Abdominal Trauma

    OpenAIRE

    Birn, Jeffrey; Jung, Melissa; Dearing, Mark

    2012-01-01

    The diagnosis of blunt injury to the gallbladder may constitute a significant challenge to the diagnostician. There is often a delay in presentation with non-specific clinical symptoms. In the absence of reliable clinical symptoms, diagnostic imaging becomes an invaluable tool in the rapid identification of gallbladder injury. We present a case of isolated gallbladder injury following blunt abdominal trauma which was diagnosed by computed tomography and subsequently confirmed by cholecystectomy.

  9. Clinical value of different detection methods in blunt ocular trauma

    Directory of Open Access Journals (Sweden)

    Yang Li

    2018-02-01

    Full Text Available Blunt ocular can cause persistent change of eye structure and function, the method of detection which is closely related to eye injury including B-can ultrasonography, UBM, OCT, FFA, scanning laser polarimetry, fundus autofluorescence, each examination with particular emphasis. This paper aims to review the advantages and disadvantages of different inspection methods in order to provide reference for clinical diagnosis and treatment of blunt ocular trauma.

  10. Unrecognized blunt tracheal trauma with massive pneumomediastinum and tension pneumothorax

    Directory of Open Access Journals (Sweden)

    Nanda Shetty

    2011-01-01

    Full Text Available Blunt neck trauma with an associated laryngotracheal injury is rare. We report a patient with blunt neck trauma who came to the emergency room and was sent to ward without realizing the seriousness of the situation. He presented later with respiratory distress and an anesthesiologist was called in for emergency airway management. Airway management in such a situation is described in this report.

  11. Duodenal Transection without Pancreatic Injury following Blunt Abdominal Trauma

    OpenAIRE

    Bankar, Sanket Subhash; Gosavi, Vikas S.; Hamid, Mohd.

    2014-01-01

    With the inventions of faster cars and even more faster motorbikes there is a worldwide increase in road traffic accidents, which has increased the incidence of blunt abdominal trauma but still duodenal injury following a blunt abdominal trauma is uncommon and can pose a formidable challenge to the surgeon and failure to manage it properly can result in devastating results. It may typically occur in isolation or with pancreatic injury. Here, we report a case of an isolated transection of the ...

  12. Value of diagnostic and therapeutic laparoscopy for patients with blunt abdominal trauma: A 10-year medical center experience.

    Science.gov (United States)

    Lin, Heng-Fu; Chen, Ying-Da; Chen, Shyr-Chyr

    2018-01-01

    Laparoscopy has been used for the diagnosis and treatment for hemodynamically stable patients with penetrating abdominal trauma. This study evaluated whether diagnostic and therapeutic laparoscopy can be used as effectively in select patients with blunt abdominal trauma. All hemodynamically stable patients undergoing operations for blunt abdominal trauma over a 10-year period (2006-2015) at a tertiary medical center were included. Patients undergoing laparotomy were categorized as group A. Patients who underwent laparoscopy were categorized as group B. The clinical outcomes of the 2 groups were compared. There were 139 patients in group A and 126 patients in group B. Group A patients were more severely injured (mean injury severity score of 23.3 vs. 18.9, P .05). Laparoscopy is a feasible and safe tool for the diagnosis and treatment of hemodynamically stable patients with blunt abdominal trauma who require surgery.

  13. Pediatric blunt splenic trauma: a comprehensive review

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, Karen N.; Werder, Gabriel M.; Callaghan, Rachel M.; Jafri, Zafar H. [William Beaumont Hospital, Department of Diagnostic Radiology, Royal Oak, MI (United States); Sullivan, Ashley N. [St. George' s University School of Medicine, Grenada, West Indies (Grenada); Bloom, David A. [William Beaumont Hospital, Department of Diagnostic Radiology, Royal Oak, MI (United States); William Beaumont Hospital, Section of Pediatric Radiology, Department of Radiology, Royal Oak, MI (United States)

    2009-09-15

    Abdominal trauma is a leading cause of death in children older than 1 year of age. The spleen is the most common organ injured following blunt abdominal trauma. Pediatric trauma patients present unique clinical challenges as compared to adults, including different mechanisms of injury, physiologic responses, and indications for operative versus nonoperative management. Splenic salvage techniques and nonoperative approaches are preferred to splenectomy in order to decrease perioperative risks, transfusion needs, duration/cost of hospitalization, and risk of overwhelming postsplenectomy infection. Early and accurate detection of splenic injury is critical in both adults and children; however, while imaging findings guide management in adults, hemodynamic stability is the primary determinant in pediatric patients. After initial diagnosis, the primary role of imaging in pediatric patients is to determine the level and duration of care. We present a comprehensive literature review regarding the mechanism of injury, imaging, management, and complications of traumatic splenic injury in pediatric patients. Multiple patients are presented with an emphasis on the American Association for the Surgery of Trauma organ injury grading system. Clinical practice guidelines from the American Pediatric Surgical Association are discussed and compared with our experience at a large community hospital, with recommendations for future practice guidelines. (orig.)

  14. Pediatric blunt splenic trauma: a comprehensive review

    International Nuclear Information System (INIS)

    Lynn, Karen N.; Werder, Gabriel M.; Callaghan, Rachel M.; Jafri, Zafar H.; Sullivan, Ashley N.; Bloom, David A.

    2009-01-01

    Abdominal trauma is a leading cause of death in children older than 1 year of age. The spleen is the most common organ injured following blunt abdominal trauma. Pediatric trauma patients present unique clinical challenges as compared to adults, including different mechanisms of injury, physiologic responses, and indications for operative versus nonoperative management. Splenic salvage techniques and nonoperative approaches are preferred to splenectomy in order to decrease perioperative risks, transfusion needs, duration/cost of hospitalization, and risk of overwhelming postsplenectomy infection. Early and accurate detection of splenic injury is critical in both adults and children; however, while imaging findings guide management in adults, hemodynamic stability is the primary determinant in pediatric patients. After initial diagnosis, the primary role of imaging in pediatric patients is to determine the level and duration of care. We present a comprehensive literature review regarding the mechanism of injury, imaging, management, and complications of traumatic splenic injury in pediatric patients. Multiple patients are presented with an emphasis on the American Association for the Surgery of Trauma organ injury grading system. Clinical practice guidelines from the American Pediatric Surgical Association are discussed and compared with our experience at a large community hospital, with recommendations for future practice guidelines. (orig.)

  15. Ascending aortic injuries following blunt trauma.

    Science.gov (United States)

    Sun, Xiumei; Hong, Jenny; Lowery, Robert; Goldstein, Steven; Wang, Zuyue; Lindsay, Joseph; Hill, Peter C; Corso, Paul J

    2013-11-01

    The diagnosis and the management of traumatic thoracic aortic injuries have undergone significant changes due to new technology and improved prehospital care. Most of the discussions have focused on descending aortic injuries. In this review, we discuss the recent management of ascending aortic injuries. We found 5 cohort studies on traumatic aortic injuries and 11 case reports describing ascending aortic injuries between 1998 to the present through Medline research. Among case reports, 78.9% of cases were caused by motor vehicle accidents (MVA). 42.1% of patients underwent emergent open repair and the operative mortality was 12.5%. 36.8% underwent delayed repair. Associated injuries occurred in 84.2% of patients. Aortic valve injury was concurrent in 26.3% of patients. The incidence of ascending aortic injury ranged 1.9-20% in cohort studies. Traumatic injuries to the ascending aorta are relatively uncommon among survivors following blunt trauma. Aortography has been replaced by computed tomography and echocardiography as a diagnostic tool. Open repair, either emergent or delayed, remains the treatment of choice. © 2013 Wiley Periodicals, Inc.

  16. Tracheobronchial injuries in blunt chest trauma

    Directory of Open Access Journals (Sweden)

    vahid Montazeri

    2004-01-01

    Full Text Available Introduction: Tracheobronchial injuries are uncommon but potentially fatal complication of blunt thoracic trauma harboring a high morbidity and mortality if not diagnosed early . A recent series gleaning cases from four major Trauma Center in Los Angeles nine cases in a seven- year period , but the incidence of these injuries has been increasing recently. This has been attributed to improvement in hospital care and advanced Trauma Centers and earlier diagnosis of such injuries. Disruption of tight main bronchus is more common, such injuries are often associated with rib or clavicular fractures. Findings: Clinical and paraclinical data gathered from records of three patients referred with tracheobronchial injuries during the recent ten years have been reviewed .These include clinical manifestations, diagnostic findings, treatment modality and clinical course. The outcome has been satisfactory in all three patients who have undergone operation 2-5 hours after sustaining the injury. We have not had any mortality. Conclusion: These results are similar to those of other series emphasizing over early diagnosis and treatment of such injuries .

  17. Blunt pancreatic trauma. Role of CT

    International Nuclear Information System (INIS)

    Procacci, C.; Graziani, R.; Bicego, E.; Mainardi, P.; Bassi, C.; Bergamo Andreis, I.A.; Valdo, M.; Guarise, A.; Girelli, M.

    1997-01-01

    Purpose: To define the evolution patterns of blunt pancreatic trauma, and to point out the CT features most significant for the diagnosis. Material and Methods: Ten cases of pancreatic trauma, observed over a period of about 10 years, were analyzed in retrospect. The cases were divided into 3 groups according to the time that had elapsed between trauma and first CT: Early phase (within 72 h: n=3/10); late phase (after 10 days: n=3/10); and following pancreatic drainage (n=4/10). Results: In the early phase, one case showed a blood collection surrounding the pancreatic head and duodenum, and displacing the mesenteric vessels to the left. In the 2 other cases it was possible to demonstrate a tear in the pancreas at the neck, perpendicular to the main pancreatic axis. In the late phase in all 3 cases, one cystic lesion was present at the site of the tear, either surrounding the gland or embedded - more or less deeply - within the parenchyma. One of the lesions subsided spontaneously; the 2 others required surgery. In the postoperative phase, an external fistula was demonstrated in 2 cases following percutaneous drainage of pancreatic cysts; the fistula was fed by a cystic lesion in the pancreatic neck. In the 2 other cases a pseudocyst developed. (orig.)

  18. Blunt pancreatic trauma. Role of CT

    Energy Technology Data Exchange (ETDEWEB)

    Procacci, C. [Dept. of Radiology, Univ. Hospital, Verona (Italy); Graziani, R. [Dept. of Radiology, Univ. Hospital, Verona (Italy); Bicego, E. [Dept. of Radiology, Univ. Hospital, Verona (Italy); Mainardi, P. [Dept. of Radiology, Univ. Hospital, Verona (Italy); Bassi, C. [Dept. of Surgery, Univ. Hospital, Verona (Italy); Bergamo Andreis, I.A. [Dept. of Radiology, Univ. Hospital, Verona (Italy); Valdo, M. [Dept. of Radiology, Univ. Hospital, Verona (Italy); Guarise, A. [Dept. of Radiology, Univ. Hospital, Verona (Italy); Girelli, M. [Dept. of Radiology, Univ. Hospital, Verona (Italy)

    1997-07-01

    Purpose: To define the evolution patterns of blunt pancreatic trauma, and to point out the CT features most significant for the diagnosis. Material and Methods: Ten cases of pancreatic trauma, observed over a period of about 10 years, were analyzed in retrospect. The cases were divided into 3 groups according to the time that had elapsed between trauma and first CT: Early phase (within 72 h: n=3/10); late phase (after 10 days: n=3/10); and following pancreatic drainage (n=4/10). Results: In the early phase, one case showed a blood collection surrounding the pancreatic head and duodenum, and displacing the mesenteric vessels to the left. In the 2 other cases it was possible to demonstrate a tear in the pancreas at the neck, perpendicular to the main pancreatic axis. In the late phase in all 3 cases, one cystic lesion was present at the site of the tear, either surrounding the gland or embedded - more or less deeply - within the parenchyma. One of the lesions subsided spontaneously; the 2 others required surgery. In the postoperative phase, an external fistula was demonstrated in 2 cases following percutaneous drainage of pancreatic cysts; the fistula was fed by a cystic lesion in the pancreatic neck. In the 2 other cases a pseudocyst developed. (orig.).

  19. Simplified pancreatoduodenectomy for complex blunt pancreaticoduodenal injury

    Directory of Open Access Journals (Sweden)

    FENG Xin-fu

    2013-10-01

    Full Text Available 【Abstract】A 34-year-old man admitted to our department with complex blunt pancreaticoduodenal injury after a car accident. The wall of the first, second, and third portions of the duodenum was extensively lacerated, and the pancreas was longitudinally transected along the superior mesenteric vein-portal vein trunk. The pancreatic head and the uncinate process were devitalized and the distal common bile duct and the proximal main pancreatic duct were completely detached from the Vater ampulla. The length of the stump of distal common bile located at the cut surface of remnant pancreas was approximately 0.6 cm. A simplified Kausch-Whipple’s procedure was performed after debridement of the devitalized pancreatic head and resection of the damaged duodenum in which the stump of distal common bile duct and the pancreatic remnant were embedded into the jejunal loop. Postoperative wound abscess appeared that eventually recovered by conservative treatment. During 16 months follow-up the patient has been stable and healthy. A simplified pancreaticoduodenectomy is a safe alternative for the Whipple procedure in managing complex pancreaticoduodenal injury in a hemodynamically stable patient. Key words: Pancreaticoduodenectomy; Abdominal injuries; Pancreas; Duodenum

  20. TREATMENT OF BLUNT LIVER INJURIES IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Ana Kostić

    2003-04-01

    Full Text Available Liver is the largest parenchymatous organ, well vascularized, weighing approximately 1.8-3.0% of the whole body weight. Among all abdominal traumas liver injuries account for 25%. For more serious liver injuries the mortality is around 40% in children below 10 years of age. For lesions of the juxtahepatic veins (three major hepatic veins or the retrohepatic portion of v. cava or for complex, combined intraabdominal injuries, the mortality is even up to 70%.This work analyzed the period 1988-2000 during which there were 19 children admitted and treated for blunt liver injuries at the Clinic of Pediatric Surgery and Orthopedics in Nis; I, II and III scale injuries prevailed (17 cases; 89.4%. These injuries were surgically treated for the most part (17 cases; 89.4%. In 7 children (36.8% there were combined injuries. The lethality was 26.3%-5 cases, with three major complications: two intrahepatic hematomas and one biliary fistula associated with biliary peritonitis and biloma formation.

  1. Emergency management of blunt chest trauma in children: an evidence-based approach.

    Science.gov (United States)

    Pauzé, Denis R; Pauzé, Daniel K

    2013-11-01

    Pediatric trauma is commonly encountered in the emergency department, and trauma to the head, chest, and abdomen may be a source of significant morbidity and mortality. As children have unique thoracic anatomical and physiological properties, they may present with diagnostic challenges that the emergency clinician must be aware of. This review examines the effects of blunt trauma to the pediatric chest, as well as its relevant etiologies and associated mortality. Diagnostic and treatment options for commonly encountered injuries such as pulmonary contusions, rib fractures, and pneumothoraces are examined. Additionally, this review discusses rarely encountered--yet highly lethal--chest wall injuries such as blunt cardiac injuries, commotio cordis, nonaccidental trauma, and aortic injuries.

  2. Blunt splenic injury in a child with situs inversus totalis treated with transcatheter arterial embolization

    Directory of Open Access Journals (Sweden)

    Naoki Hashizume

    2016-10-01

    Full Text Available We report the first case of blunt splenic rupture in a child with situs inversus totalis treated with transcatheter arterial embolization (TAE. A 12-year-old girl fell roughly 4 feet onto the pavement while riding her bicycle. Contrast-enhanced computed tomography revealed situs inversus totalis, a massive hemorrhage in the abdominal cavity, and a ruptured spleen with extravasation. Arteriography showed that the internal organs were located opposite their normal positioning. TAE was carried out with gelfoam and a micro coils at the branch of the upper lobe of the splenic artery. TAE is effective for blunt splenic injury with extravasation in a child with situs inversus. In TAE, there is no technical difference about situs inversus excepted mirror image of abdominal vascular formation.

  3. Delayed Occipital Artery Pseudoaneurysm Following Blunt Force Trauma.

    Science.gov (United States)

    Changa, Abhinav R; Meleis, Ahmed M; Bassani, Luigi

    2016-05-01

    Occipital artery pseudoaneurysms are extremely rare pathologies that manifest after traumatic injury; only 11 cases have been reported in the literature. Because of their low incidence and vague symptoms, the initial diagnosis can be difficult. However, for correctly diagnosed occipital artery pseudoaneurysms, many successful treatment modalities exist. We review the pathology of occipital pseudoaneurysms, elucidate the reasons for their rarity, discuss effective diagnostic measures, and discuss the currently available treatment options. We also present a case of a 16-year-old boy who sustained blunt force trauma in May 2014 and presented 6 months later with a painful, pulsatile mass in the occipital region. The patient underwent surgical resection to alleviate the pain and the potential risk of hemorrhage. He experienced complete resolution of pain and associated symptoms. Our case highlights the fact that occipital swelling, a significant initial sign of pseudoaneurysm development, can be delayed. Therefore, occipital artery pseudoaneurysms cannot be ruled out of the differential diagnosis based on time course alone. Surgical resection is a quick and effective method for relief of severe pain resulting from occipital artery pseudoaneurysms. Although they are rare entities, occipital artery pseudoaneurysms must be considered in the differential diagnosis of cases of pulsatile mass lesions in the posterior scalp. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Blunt body near wake flow field at Mach 6

    Science.gov (United States)

    Horvath, Thomas J.; McGinley, Catherine B.; Hannemann, Klaus

    1996-01-01

    Tests were conducted in a Mach 6 flow to examine the reattachment process of an axisymmetric free shear layer associated with the near wake of a 70 deg. half angle, spherically blunted cone with a cylindrical after body. Model angle of incidence was fixed at 0 deg. and free-stream Reynolds numbers based on body diameter ranged from 0.5 x 10(exp 6) to 4 x 10(exp 6). The sensitivity of wake shear layer transition on reattachment heating was investigated. The present perfect gas study was designed to compliment results obtained previously in facilities capable of producing real gas effects. The instrumented blunted cone model was designed primarily for testing in high enthalpy hypervelocity shock tunnels in both this country and abroad but was amenable for testing in conventional hypersonic blowdown wind tunnels as well. Surface heating rates were inferred from temperature - time histories from coaxial surface thermocouples on the model forebody and thin film resistance gages along the model base and cylindrical after body. General flow feature (bow shock, wake shear layer, and recompression shock) locations were visually identified by schlieren photography. Mean shear layer position and growth were determined from intrusive pitot pressure surveys. In addition, wake surveys with a constant temperature hot-wire anemometer were utilized to qualitatively characterize the state of the shear layer prior to reattachment. Experimental results were compared to laminar perfect gas predictions provided by a 3-D Navier Stokes code (NSHYP). Shear layer impingement on the instrumented cylindrical after body resulted in a localized heating maximum that was 21 to 29 percent of the forebody stagnation point heating. Peak heating resulting from the reattaching shear layer was found to be a factor of 2 higher than laminar predictions, which suggested a transitional shear layer. Schlieren flow visualization and fluctuating voltage time histories and spectra from the hot wire surveys

  5. Blunt splenic injury and severe brain injury: a decision analysis and implications for care

    Science.gov (United States)

    Alabbasi, Thamer; Nathens, Avery B.; Tien, Col Homer

    2015-01-01

    Background The initial nonoperative management (NOM) of blunt splenic injuries in hemodynamically stable patients is common. In soldiers who experience blunt splenic injuries with concomitant severe brain injury while on deployment, however, NOM may put the injured soldier at risk for secondary brain injury from prolonged hypotension. Methods We conducted a decision analysis using a Markov process to evaluate 2 strategies for managing hemodynamically stable patients with blunt splenic injuries and severe brain injury — immediate splenectomy and NOM — in the setting of a field hospital with surgical capability but no angiography capabilities. We considered the base case of a 40-year-old man with a life expectancy of 78 years who experienced blunt trauma resulting in a severe traumatic brain injury and an isolated splenic injury with an estimated failure rate of NOM of 19.6%. The primary outcome measured was life expectancy. We assumed that failure of NOM would occur in the setting of a prolonged casualty evacuation, where surgical capability was not present. Results Immediate splenectomy was the slightly more effective strategy, resulting in a very modest increase in overall survival compared with NOM. Immediate splenectomy yielded a survival benefit of only 0.4 years over NOM. Conclusion In terms of overall survival, we would not recommend splenectomy unless the estimated failure rate of NOM exceeded 20%, which corresponds to an American Association for the Surgery of Trauma grade III splenic injury. For military patients for whom angiography may not be available at the field hospital and who require prolonged evacuation, immediate splenectomy should be considered for grade III–V injuries in the presence of severe brain injury. PMID:26100770

  6. Finite element analysis of blunt foreign body impact on the cornea after PRK and LASIK.

    Science.gov (United States)

    Mousavi, Seyed Jamaleddin; Nassiri, Nariman; Masoumi, Nafiseh; Nassiri, Nader; Majdi-N, Mercede; Farzaneh, Solmaz; Djalilian, Ali R; Peyman, Gholam A

    2012-01-01

    To investigate the effect of blunt foreign body impact on a human cornea after photorefractive keratectomy (PRK) and LASIK using a simulation model. Computational simulations were performed using a finite element analysis program (LS-Dyna, Livermore Software Technology Corp). The blunt foreign body was set to impact at the center of the corneal surface models (after PRK and LASIK) with thicknesses of 500, 450, 400, 350, and 300 μm. Corneal rupture was assumed to occur at a peak stress of 9.45 MPa and at a strain of 18%. The foreign body projectile was blunt in shape, made from aluminum, contained plastic-kinematic properties, and had a density of 2700 kg/m(3). The projectile was launched at the center of the cornea with velocities ranging from 20 to 60 m/s. The threshold of impact velocities creating rupture in corneal thicknesses of 500, 450, 400, 350, and 300 μm were 33, 32.8, 30.7, 27.9, and 22.8 m/s, respectively, in the PRK model. In the LASIK model, the thresholds creating rupture in the stromal bed of the corneas with thicknesses of 500, 450, 400, 350, and 300 μm were 40, 38.1, 35.6, 31.5, and 26.7 m/s, respectively. The 110-μm corneal flap in the LASIK model ruptured at all velocities. Ruptures occurred at lower velocities in the PRK cornea model than in the corneal stromal bed of the LASIK model following blunt foreign body impact. Copyright 2012, SLACK Incorporated.

  7. The use of laparoscopy in the diagnosis and treatment of blunt and penetrating abdominal injuries: 10-year experience at a level 1 trauma center.

    Science.gov (United States)

    Johnson, Jeremy J; Garwe, Tabitha; Raines, Alexander R; Thurman, Joseph B; Carter, Sandra; Bender, Jeffrey S; Albrecht, Roxie M

    2013-03-01

    Diagnostic laparoscopy (DL) has decreased the rate of nontherapeutic laparotomy for patients suffering from penetrating injuries. We evaluated whether DL similarly lowers the rate of nontherapeutic laparotomy for patients with blunt injuries. All patients undergoing DL over a 10-year period (ie, 2001-2010) in a single level 1 trauma center were classified by the mechanism of injury. Demographic and perioperative data were compared using the Student t and Fisher exact tests. There were 131 patients included, 22 of whom sustained blunt injuries. Patients suffering from blunt injuries were more severely injured (Injury Severity Score 18.0 vs 7.3, P = .0001). The most common indication for DL after blunt injury was a computed tomographic scan concerning for bowel injury (59.1%). The rate of nontherapeutic laparotomy for patients sustaining penetrating vs blunt injury was 1.8% and nil, respectively. DL, when coupled with computed tomographic findings, is an effective tool for the initial management of patients with blunt injuries. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. The efficacy of transcatheter arterial embolization (TAE) in children with blunt splenic injury

    International Nuclear Information System (INIS)

    Park, Si Kyun; Kim, Young Ju; Kwon, Taek Sang; Kim, Jong Jin; Ko, Sung Min; Sung, Ki Joon

    1998-01-01

    The purpose of this study is to evaluate the efficacy of transcatheter arterial embolization (TAE) in children with blunt splenic injury. The results of transcatheter splenic arterial embolization in nine children who suffered splenic injury after blunt abdominal trauma were retrospectively studied. This injury was demonstrated by CT, and the findings were evaluated according to the classification of Mirvis et al.; two patients were grade 3 and seven were grade 4. All were carefully observed in intensive care before embolization. TAE was performed if a patient satisfied the following criteria : (1) transfusion and/or fluid replacement required to maintain hemodynamic stability; or (2) rapid Hb/Hct decrease; or (3) both. Splenic function was subsequently estimated according to the results of 09m Tc-sulfur colloid scintigraphy and/or CT scanning. TAE was successful in all nine children. Two were embolized with a coil only, three with gelfoam, and four with gelfoam and a coil. Seven were embolized in the main trunk of the splenic artery and others in both the main trunk and its branches. Splenic function was preserved in all nine children, during follow-up, none suffered rebleeding. TAE of the splenic artery can be a safe and effective nonsurgical approach to the management of blunt splenic injury in children, and can preserve splenic function. (author). 18 refs., 2 tabs., 3 figs

  9. The efficacy of transcatheter arterial embolization (TAE) in children with blunt splenic injury

    Energy Technology Data Exchange (ETDEWEB)

    Park, Si Kyun; Kim, Young Ju; Kwon, Taek Sang; Kim, Jong Jin; Ko, Sung Min; Sung, Ki Joon [Yonsei University, Wonju (Korea, Republic of). Wonju Coll. of Medicine

    1998-06-01

    The purpose of this study is to evaluate the efficacy of transcatheter arterial embolization (TAE) in children with blunt splenic injury. The results of transcatheter splenic arterial embolization in nine children who suffered splenic injury after blunt abdominal trauma were retrospectively studied. This injury was demonstrated by CT, and the findings were evaluated according to the classification of Mirvis et al.; two patients were grade 3 and seven were grade 4. All were carefully observed in intensive care before embolization. TAE was performed if a patient satisfied the following criteria : (1) transfusion and/or fluid replacement required to maintain hemodynamic stability; or (2) rapid Hb/Hct decrease; or (3) both. Splenic function was subsequently estimated according to the results of {sup 09m}Tc-sulfur colloid scintigraphy and/or CT scanning. TAE was successful in all nine children. Two were embolized with a coil only, three with gelfoam, and four with gelfoam and a coil. Seven were embolized in the main trunk of the splenic artery and others in both the main trunk and its branches. Splenic function was preserved in all nine children, during follow-up, none suffered rebleeding. TAE of the splenic artery can be a safe and effective nonsurgical approach to the management of blunt splenic injury in children, and can preserve splenic function. (author). 18 refs., 2 tabs., 3 figs.

  10. Abdominal computed tomography scan as a screening tool in blunt trauma

    International Nuclear Information System (INIS)

    Brasel, K.J.; Borgstrom, D.C.; Kolewe, K.A.

    1997-01-01

    Background. One of the most difficult problems in blunt trauma is evaluation for potential intraabdominal injury. Admission for serial abdominal exams remains the standard of care after intraabdominal injury has been initially excluded. We hypothesized a normal abdominal computed tomography (CT) scan in a subgroup of minimally injured patients would obviate admission for serial abdominal examinations, allowing safe discharge from the emergency department (ED). Methods. We reviewed our blunt trauma experience with patients admitted solely for serial abdominal examinations after a normal CT. Patients were identified from the trauma registry at a Level 1 trauma center from July 1991 through June 1995. Patients with abnormal CTs, extra-abdominal injuries necessitating admission, hemodynamic abnormalities, a Glasgow Coma Scale less than 13, or injury severity scores (ISSs) greater than 15 were excluded. Records of 238 patients remained; we reviewed them to determine the presence of missed abdominal injury. Results. None of the 238 patients had a missed abdominal injury. Average ISS of these patients was 3.2 (range, 0 to 10). Discharging these patients from the ED would result in a yearly cost savings of $32,874 to our medical system. Conclusions. Abdominal CT scan is a safe and cost-effective screening tool in patients with blunt trauma. A normal CT scan in minimally injured patients allows safe discharge from the ED. (authors)

  11. Flow establishment behind blunt bodies at hypersonic speeds in a shock tunnel

    Science.gov (United States)

    Park, G.; Hruschka, R.; Gai, S. L.; Neely, A. J.

    2008-11-01

    An investigation of flow establishment behind two blunt bodies, a circular cylinder and a 45° half-angle blunted-cone was conducted. Unlike previous studies which relied solely on surface measurements, the present study combines these with unique high-speed visualisation to image the establishment of the flow structure in the base region. Test flows were generated using a free-piston shock tunnel at a nominal Mach number of 10. The freestream unit Reynolds numbers considered were 3.02x105/m and 1.17x106/m at total enthalpies of 13.35MJ/kg and 3.94MJ/kg, respectively. In general, the experiments showed that it takes longer to establish steady heat flux than pressure. The circular cylinder data showed that the near wake had a slight Reynolds number effect, where the size of the near wake was smaller for the high enthalpy flow condition. The blunted-cone data showed that the heat flux and pressures reached steady states in the near wake at similar times for both high and low enthalpy conditions.

  12. Surface Heat Flux and Pressure Distribution on a Hypersonic Blunt Body With DEAS

    Science.gov (United States)

    Salvador, I. I.; Minucci, M. A. S.; Toro, P. G. P.; Oliveira, A. C.; Channes, J. B.

    2008-04-01

    With the currently growing interest for advanced technologies to enable hypersonic flight comes the Direct Energy Air Spike concept, where pulsed beamed laser energy is focused upstream of a blunt flight vehicle to disrupt the flow structure creating a virtual, slender body geometry. This allies in the vehicle both advantages of a blunt body (lower thermal stresses) to that of a slender geometry (lower wave drag). The research conducted at the Henry T. Nagamatsu Laboratory for Aerodynamics and Hypersonics focused on the measurement of the surface pressure and heat transfer rates on a blunt model. The hypersonic flight conditions were simulated at the HTN Laboratory's 0.3 m T2 Hypersonic Shock Tunnel. During the tests, the laser energy was focused upstream the model by an infrared telescope to create the DEAS effect, which was supplied by a TEA CO2 laser. Piezoelectric pressure transducers were used for the pressure measurements and fast response coaxial thermocouples were used for the measurement of surface temperature, which was later used for the estimation of the wall heat transfer using the inverse heat conduction theory.

  13. [The mechanisms of formation of liver injuries associated with the blunt abdominal trauma].

    Science.gov (United States)

    Pigolkin, Iu I; Dubrovina, I A; Dubrovin, I A

    2012-01-01

    The mechanisms of liver damage associated with the blunt abdominal trauma are considered based on the analysis of the literature publications. The general characteristic of these mechanisms and the processes underlying the development of liver injuries is presented. It is argued that the mechanisms underlying the formation of damages to the liver differ depending on the form of the traumatic impact, the injurious factor, and the processes leading to the destruction of the hepatic tissue. The main forms of traumatic impact in the case of a blunt abdominal trauma include the strike (blow), pressure, and concussion of the organ while the major traumatic factors are deformation, displacement, and "shock-resistant effects". The mechanisms underlying tissue destruction are compression and stretching. These two mechanisms are responsible for the formation of different variants of liver destruction. The results of the study suggest the necessity of the search for other mechanisms of degradation of the hepatic tissue following a blunt abdominal trauma for the improvement of forensic medical diagnostics of its cause and the underlying mechanism.

  14. Multidetector CT findings of bowel Transection in blunt abdominal trauma

    International Nuclear Information System (INIS)

    Cho, Hyun Suk; Woo, Ji Young; Hong, Hye Suk; Park, Mee Hyun; Yang, Ik; Lee, Yul; Jung, Ah Young; Hwang, Ji Young; Ha, Hong Il

    2013-01-01

    Though a number of CT findings of bowel and mesenteric injuries in blunt abdominal trauma are described in literature, no studies on the specific CT signs of a transected bowel have been published. In the present study we describe the incidence and new CT signs of bowel transection in blunt abdominal trauma. We investigated the incidence of bowel transection in 513 patients admitted for blunt abdominal trauma who underwent multidetector CT (MDCT). The MDCT findings of 8 patients with a surgically proven complete bowel transection were assessed retrospectively. We report novel CT signs that are unique for transection, such as complete cutoff sign (transection of bowel loop), Janus sign (abnormal dual bowel wall enhancement, both increased and decreased), and fecal spillage. The incidence of bowel transection in blunt abdominal trauma was 1.56%. In eight cases of bowel transection, percentage of CT signs unique for bowel transection were as follows: complete cutoff in 8 (100%), Janus sign in 6 (100%, excluding duodenal injury), and fecal spillage in 2 (25%). The combination of complete cutoff and Janus sign were highly specific findings in patients with bowel transection. Complete cut off and Janus sign are the unique CT findings to help detect bowel transection in blunt abdominal trauma and recognition of these findings enables an accurate and prompt diagnosis for emergency laparotomy leading to reduced mortality and morbidity.

  15. The Role of Computed Tomography in Blunt Abdominal Trauma.

    Science.gov (United States)

    Karki, O B

    2015-01-01

    Blunt injury trauma is regularly encountered in the emergency department. Diagnostic tools that help in optimum management of blunt abdominal trauma include; Focussed Assessment Sonography for Trauma scan, Diagnostic peritoneal lavage and Computed Tomography scan. The aim of this study is to determine the validity of CT scan as an accurate diagnostic tool and its role in management of patients with blunt abdominal trauma. A prospective analysis of 80 patients of blunt abdomen trauma who were admitted in Manipal Teaching Hospital, Pokhara, Nepal within a span of 15 months was done. Demographic data, mechanism of trauma, management and outcomes were studied. Organ injuries were graded using the Organ Injury Scale guidelines. Most of the patients in our study were in the age group of 21-40 years with an M: F ratio of 2.3:1. Road traffic accident (47.5%) was the most common mechanism of injury. Spleen (27.5%) was the commonest organ injured. CT scan was superior to FAST scan and had sensitivity of 97.3% specificity 75% positive predictive value 98.6%. FAST scan had sensitivity of 78.9%, specificity 50%, positive predictive value 96% with p- value of 0.0034. 81% of patients were conservatively managed. In conjunction with close clinical monitoring, CT scan is reliable in the evaluation and management of blunt abdominal trauma patients. Our study also shows CT as a superior diagnostic modality compared to FAST scan.

  16. Role of computed tomography in blunt chest trauma

    International Nuclear Information System (INIS)

    Cho, Jae Hyun; Kim, Sang Jin; Lee, Chan Wha; Kim, Hae Kyoon

    1994-01-01

    In patient with blunt trauma of chest, supine AP x-ray cannot differentiate the lung contusion, laceration, atelectasis, and hemothorax definitely. Therefore, computed tomographic evaluation is needed for accurate evaluation of the injuries. In our knowledge, there are few reports about CT findings of blunt chest trauma, in our country, therefore we tried to fluid the characteristic CT findings in patients with blunt trauma. We analyzed the plain x-ray and CT image of 4 patients with blunt chest trauma. Location and morphology of lung parenchymal contusion and laceration, hemopneumothorax, chest wall injuries and location of chest tube. Lung parenchymal contusion was noted in 53 segments., of 16 patients infiltration(n=27 segment), and multiple nodular pattern was noted in 15 segment, pattern of consolidation along the lung periphery was seen in 11 segment. Laceration was noted in 18 lesion and most commonly located in paravertebral area(b=8). CT scan of chest in patient with blunt chest trauma, provides accurate information of the pattern of injuries, and localization, therefore, should be performed as possible

  17. Independent predictors of morbidity and mortality in blunt colon trauma.

    Science.gov (United States)

    Ricciardi, R; Paterson, C A; Islam, S; Sweeney, W B; Baker, S P; Counihan, T C

    2004-01-01

    We sought to determine the impact of (1) grade of the colon injury, (2) the formation of an ostomy, and (3) associated injuries on outcomes such as morbidity and mortality after blunt colon injuries. We retrospectively reviewed 16,814 cases of blunt abdominal trauma. Patients with colonic injuries were selected and charts reviewed for demographic, clinical, and outcomes data. Injuries were grouped by the Colon Injury Scale (grades I-V). Independent risk factors of morbidity included spine and lung injuries, as well as increased age. A higher grade of colon injury trended toward a significant association with intra-abdominal complications. Independent risk factors of mortality included liver, heart, and lung injuries, as well as intracerebral blood and female gender. The grade of colon injury, the formation of an ostomy, and management of the colon trauma did not independently predict increased intra-abdominal complications, morbidity, or mortality. These results indicate that patients afflicted with blunt colon trauma experience a high rate of morbidity and mortality from associated injuries and or increased age. Treatment regimens directed at these factors will be most helpful in reducing the high morbidity and mortality after blunt colon trauma. Factors such as ostomy formation and management strategy are not associated with increased morbidity or mortality after blunt colon trauma.

  18. Improvement of airfoil trailing edge bluntness noise model

    Directory of Open Access Journals (Sweden)

    Wei Jun Zhu

    2016-02-01

    Full Text Available In this article, airfoil trailing edge bluntness noise is investigated using both computational aero-acoustic and semi-empirical approach. For engineering purposes, one of the most commonly used prediction tools for trailing edge noise are based on semi-empirical approaches, for example, the Brooks, Pope, and Marcolini airfoil noise prediction model developed by Brooks, Pope, and Marcolini (NASA Reference Publication 1218, 1989. It was found in previous study that the Brooks, Pope, and Marcolini model tends to over-predict noise at high frequencies. Furthermore, it was observed that this was caused by a lack in the model to predict accurately noise from blunt trailing edges. For more physical understanding of bluntness noise generation, in this study, we also use an advanced in-house developed high-order computational aero-acoustic technique to investigate the details associated with trailing edge bluntness noise. The results from the numerical model form the basis for an improved Brooks, Pope, and Marcolini trailing edge bluntness noise model.

  19. Comparing 2-nt 3' overhangs against blunt-ended siRNAs: a systems biology based study.

    Science.gov (United States)

    Ghosh, Preetam; Dullea, Robert; Fischer, James E; Turi, Tom G; Sarver, Ronald W; Zhang, Chaoyang; Basu, Kalyan; Das, Sajal K; Poland, Bradley W

    2009-07-07

    In this study, we formulate a computational reaction model following a chemical kinetic theory approach to predict the binding rate constant for the siRNA-RISC complex formation reaction. The model allowed us to study the potency difference between 2-nt 3' overhangs against blunt-ended siRNA molecules in an RNA interference (RNAi) system. The rate constant predicted by this model was fed into a stochastic simulation of the RNAi system (using the Gillespie stochastic simulator) to study the overall potency effect. We observed that the stochasticity in the transcription/translation machinery has no observable effects in the RNAi pathway. Sustained gene silencing using siRNAs can be achieved only if there is a way to replenish the dsRNA molecules in the cell. Initial findings show about 1.5 times more blunt-ended molecules will be required to keep the mRNA at the same reduced level compared to the 2-nt overhang siRNAs. However, the mRNA levels jump back to saturation after a longer time when blunt-ended siRNAs are used. We found that the siRNA-RISC complex formation reaction rate was 2 times slower when blunt-ended molecules were used pointing to the fact that the presence of the 2-nt overhangs has a greater effect on the reaction in which the bound RISC complex cleaves the mRNA.

  20. Protocol compliance and time management in blunt trauma resuscitation.

    Science.gov (United States)

    Spanjersberg, W R; Bergs, E A; Mushkudiani, N; Klimek, M; Schipper, I B

    2009-01-01

    To study advanced trauma life support (ATLS) protocol adherence prospectively in trauma resuscitation and to analyse time management of daily multidisciplinary trauma resuscitation at a level 1 trauma centre, for both moderately and severely injured patients. All victims of severe blunt trauma were consecutively included. Patients with a revised trauma score (RTS) of 12 were resuscitated by a "minor trauma" team and patients with an RTS of less than 12 were resuscitated by a "severe trauma" team. Digital video recordings were used to analyse protocol compliance and time management during initial assessment. From 1 May to 1 September 2003, 193 resuscitations were included. The "minor trauma" team assessed 119 patients, with a mean injury severity score (ISS) of 7 (range 1-45). Overall protocol compliance was 42%, ranging from 0% for thoracic percussion to 93% for thoracic auscultation. The median resuscitation time was 45.9 minutes (range 39.7-55.9). The "severe team" assessed 74 patients, with a mean ISS of 22 (range 1-59). Overall protocol compliance was 53%, ranging from 4% for thoracic percussion to 95% for thoracic auscultation. Resuscitation took 34.8 minutes median (range 21.6-44.1). Results showed the current trauma resuscitation to be ATLS-like, with sometimes very low protocol compliance rates. Timing of secondary survey and radiology and thus time efficiency remains a challenge in all trauma patients. To assess the effect of trauma resuscitation protocols on outcome, protocol adherence needs to be improved.

  1. Wake of a blunt planetary probe model under hypervelocity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kastell, D.; Hannemann, D.; Eitelberg, G. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Goettingen (Germany). Inst. fuer Stroemungsmechanik

    1998-12-31

    The flow in the wake of a planetary probe under hypervelocity re-entry conditions has two idiosyncrasies not present in the conventional (cold) hypersonic flows: the strong dissociation reaction occurring behind the bow shock wave, and the freezing of the chemical reactions of the flow by the rapid expansion at the shoulder of the probe. The aim of the present study was to both understand the relative importance of the two phenomena upon the total heat and pressure loads on a planetary probe and its possible payload as well as to provide experimental validation data for those developing numerical codes for planetary probe design and analysis. For the experimental study an instrumented blunted 140 cone was tested in the High Enthalpy Shock Tunnel in Goettingen (HEG). The numerical calculations were performed with a Thin-Layer Navier-Stokes code which is capable of simulating chemical and thermal nonequilibrium flows. For the forebody loads the prediction methods were very reliable and capable of accounting for the kinetic effects caused by the high specific enthalpy of the flow. On the other side considerable discrepancies between experimental and numerical results for the wake of the model have been observed. (orig.)

  2. Wake of a blunt planetary probe model under hypervelocity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kastell, D.; Hannemann, D.; Eitelberg, G. (DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Goettingen (Germany). Inst. fuer Stroemungsmechanik)

    1998-01-01

    The flow in the wake of a planetary probe under hypervelocity re-entry conditions has two idiosyncrasies not present in the conventional (cold) hypersonic flows: the strong dissociation reaction occurring behind the bow shock wave, and the freezing of the chemical reactions of the flow by the rapid expansion at the shoulder of the probe. The aim of the present study was to both understand the relative importance of the two phenomena upon the total heat and pressure loads on a planetary probe and its possible payload as well as to provide experimental validation data for those developing numerical codes for planetary probe design and analysis. For the experimental study an instrumented blunted 140 cone was tested in the High Enthalpy Shock Tunnel in Goettingen (HEG). The numerical calculations were performed with a Thin-Layer Navier-Stokes code which is capable of simulating chemical and thermal nonequilibrium flows. For the forebody loads the prediction methods were very reliable and capable of accounting for the kinetic effects caused by the high specific enthalpy of the flow. On the other side considerable discrepancies between experimental and numerical results for the wake of the model have been observed. (orig.)

  3. Management of diaphragmatic rupture from blunt trauma.

    Science.gov (United States)

    Tan, K K; Yan, Z Y; Vijayan, A; Chiu, M T

    2009-12-01

    Diagnosis of diaphragmatic rupture is difficult, and delays could result in a catastrophic outcome. We reviewed our institution's management of patients with diaphragmatic rupture after blunt trauma. All patients in this study were treated at Tan Tock Seng Hospital, Singapore, from March 2002 to October 2008. Patients with penetrating injuries were excluded. The parameters included age, mechanism of injury, haemodynamic status at admission, Glasgow coma scale (GCS) score, injury severity score (ISS), imaging studies, location of diaphragmatic injuries, associated injuries and outcome. 14 patients with a median age of 38 years formed the study group. Vehicular-related incidents accounted for 71.4 percent of the injuries. The median GCS score on admission was 14 (range 3-15), while the median systolic blood pressure and heart rate were 94 (range 50-164) mmHg and 110 (range 76-140) beats per minute, respectively. The median ISS was 41 (range 14-66). All had chest radiographs performed in the emergency department, six (42.9 percent) had computed tomography performed before surgery, while the remaining eight (57.1 percent) were sent straight to the operating theatre from the emergency department. There were five (35.7 percent) right-sided and nine (64.3 percent) left-sided diaphragmatic ruptures. The mortality rate was 35.7 percent. Some of the associated injuries included eight (57.1 percent) splenic lacerations, five (35.7 percent) haemothorax and lung injuries, four (28.6 percent) bone fractures and three (21.4 percent) liver lacerations. 12 (85.7 percent) patients underwent repair of the diaphragmatic rupture using interrupted polypropylene suture, while the remaining two (14.3 percent) were too haemodynamically unstable to undergo definitive treatment. Advanced age, haemodynamic instability and raised ISS were associated with mortality. An accurate diagnosis of diaphragmatic rupture in trauma patients is difficult, and a thorough examination of both the

  4. The cigar as a drug delivery device: youth use of blunts.

    Science.gov (United States)

    Soldz, Stephen; Huyser, Dana Joy; Dorsey, Elizabeth

    2003-10-01

    Blunts are hollowed-out cigars used to smoke marijuana (and perhaps other substances) in the United States. We investigated rates of blunt use; whether cigar use reported in surveys may actually be blunt use; the relationship of blunt to cigar use; characteristics of blunt users; brands of cigars used to make blunts; and drugs added to blunts. A school-based survey of youth, the Cigar Use Reasons Evaluation (CURE). Eleven schools across Massachusetts. A total of 5016 students in grades 7-12. CURE items assessing blunt, cigar and cigarette use, brands used to make blunts, drugs added to blunts and demographics were used. Life-time blunt use was reported by 20.0% of the sample, with use greater among high school (25.6%) than middle school (11.4%) students, and among males (23.7%) than females (16.6%). Self-reported cigar use rates were not influenced strongly by blunt use being misreported as cigar use. In a multivariate model, blunt use was associated with male gender, higher grade in school, lower GPA, truancy, lower school attachment, not living in a two-parent family, being of 'other' race/ethnicity and current use of both cigarettes and cigars. 'Phillies' was the most popular brand of cigar for making blunts, used by 59% of users. 'Garcia y Vega' (18.0%) was the second most popular. Twenty-eight per cent of blunt users had added drugs other than marijuana to blunts. The use of blunts as a drug delivery device is a serious problem. Efforts to address it will require the cooperation of the tobacco control and substance abuse prevention systems.

  5. MAIN CONTROVERSIES IN THE NONOPERATIVE MANAGEMENT OF BLUNT SPLENIC INJURIES.

    Science.gov (United States)

    Carlotto, Jorge Roberto Marcante; Lopes-Filho, Gaspar de Jesus; Colleoni-Neto, Ramiro

    2016-03-01

    The nonoperative management of traumatic spleen injuries is the modality of choice in patients with blunt abdominal trauma and hemodynamic stability. However, there are still questions about the treatment indication in some groups of patients, as well as its follow-up. Update knowledge about the spleen injury. Was performed review of the literature on the nonoperative management of blunt injuries of the spleen in databases: Cochrane Library, Medline and SciELO. Were evaluated articles in English and Portuguese, between 1955 and 2014, using the headings "splenic injury, nonoperative management and blunt abdominal trauma". Were selected 35 articles. Most of them were recommendation grade B and C. The spleen traumatic injuries are frequent and its nonoperative management is a worldwide trend. The available literature does not explain all aspects on treatment. The authors developed a systematization of care based on the best available scientific evidence to better treat this condition.

  6. [The theory of cardiac lesions from blunt chest injury].

    Science.gov (United States)

    Tumanov, E V; Sokolova, Z Iu

    2010-01-01

    The main theories of myocardial lesions associated with a blunt chest injury proposed starting from the XIXth century till the present time are considered based on the overview of the literature data. It is shown that the theory of selective mechanical activation of ATP-dependent K+ channels is most promising for further investigations into the mechanisms of myocardial dysfunction resulting from blunt chest injuries. The authors emphasize the absence of the universally accepted theory explaining the mechanism behind traumatic cardiac troubles and its fatal outcome despite numerous studies of cardiac lesions in patients with a blunt chest injury. It dictates the necessity of further research, both clinical and experimental, for a deeper insight into the problem.

  7. About Usefulness of Kalemia Monitoring after Blunt Liver Trauma

    Directory of Open Access Journals (Sweden)

    Francesco Meriggi

    2012-01-01

    Full Text Available Background. The aim of this study is to investigate the evidence of hypokalemia as a suitable parameter for therapeutic decision making after severe blunt liver trauma. Methods. We reviewed the medical records of 11 patients (9 M, 2 F, mean age 32 years admitted to San Matteo Hospital of Pavia between 2007–2009. All of them were victims of road accidents hospitalized for blunt liver injury and submitted to surgery. Results. Hypokalemia was observed in 7/11 (63.6% patients during the preoperative period (mean value 2.91 mEq/L. Serum potassium concentration normalized in all patients at the 7th postoperative day only (<0.01. Conclusions. According to literature results, our study confirms that after blunt hepatic injury serum potassium levels may decrease significantly. Therefore, kalemia must be carefully monitored in order to establish appropriate treatment and avoid any complications.

  8. Non-operative management versus operative management in high-grade blunt hepatic injury.

    Science.gov (United States)

    Cirocchi, Roberto; Trastulli, Stefano; Pressi, Eleonora; Farinella, Eriberto; Avenia, Stefano; Morales Uribe, Carlos Hernando; Botero, Ana Maria; Barrera, Luis M

    2015-08-24

    Surgery used to be the treatment of choice in cases of blunt hepatic injury, but this approach gradually changed over the last two decades as increasing non-operative management (NOM) of splenic injury led to its use for hepatic injury. The improvement in critical care monitoring and computed tomographic scanning, as well as the more frequent use of interventional radiology techniques, has helped to bring about this change to non-operative management. Liver trauma ranges from a small capsular tear, without parenchymal laceration, to massive parenchymal injury with major hepatic vein/retrohepatic vena cava lesions. In 1994, the Organ Injury Scaling Committee of the American Association for the Surgery of Trauma (AAST) revised the Hepatic Injury Scale to have a range from grade I to VI. Minor injuries (grade I or II) are the most frequent liver injuries (80% to 90% of all cases); severe injuries are grade III-V lesions; grade VI lesions are frequently incompatible with survival. In the medical literature, the majority of patients who have undergone NOM have low-grade liver injuries. The safety of NOM in high-grade liver lesions, AAST grade IV and V, remains a subject of debate as a high incidence of liver and collateral extra-abdominal complications are still described. To assess the effects of non-operative management compared to operative management in high-grade (grade III-V) blunt hepatic injury. The search for studies was run on 14 April 2014. We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library, Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic+Embase (Ovid), PubMed, ISI WOS (SCI-EXPANDED, SSCI, CPCI-S & CPSI-SSH), clinical trials registries, conference proceedings, and we screened reference lists. All randomised trials that compare non-operative management versus operative management in high-grade blunt hepatic injury. Two authors independently

  9. Aerothermodynamics of Blunt Body Entry Vehicles. Chapter 3

    Science.gov (United States)

    Hollis, Brian R.; Borrelli, Salvatore

    2011-01-01

    In this chapter, the aerothermodynamic phenomena of blunt body entry vehicles are discussed. Four topics will be considered that present challenges to current computational modeling techniques for blunt body environments: turbulent flow, non-equilibrium flow, rarefied flow, and radiation transport. Examples of comparisons between computational tools to ground and flight-test data will be presented in order to illustrate the challenges existing in the numerical modeling of each of these phenomena and to provide test cases for evaluation of Computational Fluid Dynamics (CFD) code predictions.

  10. Multidetector Computer Tomography: Evaluation of Blunt Chest Trauma in Adults

    International Nuclear Information System (INIS)

    Palas, J.; Matos, A.P.; Ramalho, M.; Mascarenhas, V.; Heredia, V.

    2014-01-01

    Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall.

  11. INTER LABORATORY COMBAT HELMET BLUNT IMPACT TEST METHOD COMPARISON

    Science.gov (United States)

    2018-03-26

    data by Instrumentation for Impact  Test , SAE standard J211‐1 [4]. Although the entire curve is collected, the interest of this  project  team  solely...HELMET BLUNT IMPACT TEST METHOD COMPARISON by Tony J. Kayhart Charles A. Hewitt and Jonathan Cyganik March 2018 Final...INTER-LABORATORY COMBAT HELMET BLUNT IMPACT TEST METHOD COMPARISON 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

  12. Multidetector Computer Tomography: Evaluation of Blunt Chest Trauma in Adults

    Directory of Open Access Journals (Sweden)

    João Palas

    2014-01-01

    Full Text Available Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall.

  13. Spleen artery embolization increases the success of nonoperative management following blunt splenic injury

    Directory of Open Access Journals (Sweden)

    Isaac Chun-Jen Chen

    2011-08-01

    Conclusion: Performance of SAE for the patients with blunt splenic injury could increase the successful rate of NOM significantly and safely. An algorithm including the angioembolization might be beneficial in the management of patients with blunt spleen trauma.

  14. Blunt Splenic Trauma in Children : Are We Too Careful?

    NARCIS (Netherlands)

    De Jong, W. J. J.; Nellensteijn, D. R.; ten Duis, H. J.; Albers, M. J. I. J.; El Moumni, M.; Hulscher, J. B. F.

    Introduction: There has been a shift from operative treatment (OT) to non-operative treatment (NOT) of splenic injury. We evaluated the outcomes of treatment of pediatric patients with blunt splenic trauma in our hospital, with special focus on the outcomes after NOT. Patients and Methods: The data

  15. Delayed splenic rupture presenting 70 days following blunt abdominal trauma.

    Science.gov (United States)

    Resteghini, Nancy; Nielsen, Jonpaul; Hoimes, Matthew L; Karam, Adib R

    2014-01-01

    Delayed splenic rupture following conservative management of splenic injury is an extremely rare complication. We report a case of an adult patient who presented with delayed splenic rupture necessitating splenectomy, 2 months following blunt abdominal trauma. Imaging at the initial presentation demonstrated only minimal splenic contusion and the patient was discharge following 24 hours of observation. © 2014.

  16. Determinants of splenectomy in splenic injuries following blunt abdominal trauma.

    Science.gov (United States)

    Akinkuolie, A A; Lawal, O O; Arowolo, O A; Agbakwuru, E A; Adesunkanmi, A R K

    2010-02-01

    The management of splenic injuries has shifted from splenectomy to splenic preservation owing to the risk of overwhelming post-splenectomy infection (OPSI). This study aimed to identify the factors that determine splenectomy in patients with isolated splenic injuries, with a view to increasing the rate of splenic preservation. Files of 55 patients managed for isolated splenic injuries from blunt abdominal trauma between 1998 and 2007 were retrospectively analysed using a pro forma. Management options were classified into nonoperative, operative salvage and splenectomy. The majority of patients suffered splenic injury as a result of motor vehicle accident (MVA) trauma or falls. Splenectomy was undertaken in 33 (60%) patients, 12 (22%) had non-operative management, and operative salvage was achieved in 10 (18%) patients. Significant determinants of splenectomy were grade of splenic injury, hierarchy of the surgeon, and hierarchy of the assistant. MVA injury and falls accounted for the vast majority of blunt abdominal trauma in this study. The rate and magnitude of energy transferred versus splenic protective mechanisms at the time of blunt abdominal trauma seems to determine the grade of splenic injury. Interest in splenic salvage surgery, availability of technology that enables splenic salvage surgery, and the experience of the surgeon and assistant appear to determine the surgical management. Legislation on vehicle safety and good parental control may reduce the severity of splenic injury in blunt abdominal trauma. When surgery is indicated, salvage surgery should be considered in intermediate isolated splenic injury to reduce the incidence of OPSI.

  17. The Role of Computed Tomography in Blunt Abdominal Trauma

    Directory of Open Access Journals (Sweden)

    Om Bahadur Karki

    2016-10-01

    aim of this study is to determine the validity of CT scan as an accurate diagnostic tool and its role in management of patients with blunt abdominal trauma. Methods: A prospective analysis of 80 patients of blunt abdomen trauma who were admitted in Manipal Teaching Hospital, Pokhara, Nepal within a span of 15 months was done. Demographic data, mechanism of trauma, management and outcomes were studied. Organ injuries were graded using the Organ Injury Scale guidelines. Results: Most of the patients in our study were in the age group of 21-40 years with an M: F ratio of 2.3:1. Road traf c accident (47.5% was the most common mechanism of injury. Spleen (27.5% was the commonest organ injured. CT scan was superior to FAST scan and had sensitivity of 97.3% speci city 75% positive predictive value 98.6%. FAST scan had sensitivity of 78.9%, speci city 50%, positive predictive value 96% with p- value of 0.0034. 81% of patients were conservatively managed. Conclusion: In conjunction with close clinical monitoring, CT scan is reliable in the evaluation and management of blunt abdominal trauma patients. Our study also shows CT as a superior diagnostic modality compared to FAST scan. Keywords: blunt abdominal trauma; CT scan; FAST scan; road traf c accident.

  18. Factors for failure of nonoperative management of blunt ...

    African Journals Online (AJOL)

    The aim is to evaluate factors for failure of NOM for blunt abdominal ... and contrast blush on the CT scan increase the risk of failure of NOM .... Lung contusion. 23 (16.1) .... abscesses, delayed hepatic or splenic bleeding, bilomas, and missed ...

  19. Unusual blunt force wound produced by a gun muzzle.

    Science.gov (United States)

    Hanzlick, R; Zaki, S A

    1986-09-01

    Most blunt force injuries produced by guns are associated with gun butts, and patterned, muzzle/sight impressions are usually produced by discharging firearms. An unusual and distinct forehead laceration produced by a blow with the muzzle end of a .32 caliber revolver is presented.

  20. Use of urethral catheters for diagnostic peritoneal lavage in blunt ...

    African Journals Online (AJOL)

    Background: Diagnostic peritoneal lavage (DPL) has been reported to be a reliable diagnostic tool in assessing the need for liparotomy in blunt abdominal trauma (BAT) with a diagnostic accuracy of more thin 95% when using a peritoneal lavage catheter (PLC). The aim of this study was to determine the diagnostic ...

  1. Transient electrocardiographic abnormalities following blunt chest trauma in a child

    NARCIS (Netherlands)

    Udink ten Cate, Floris; Heerde, van Marc; Rammeloo, Lukas; Hruda, Jaroslav

    2008-01-01

    Blunt cardiac injury may occur in patients after suffering nonpenetrating trauma of the chest. It encompasses a wide spectrum of cardiac injury with varied severity and clinical presentation. Electrocardiographic abnormalities are frequently encountered. This article presents a case of a child

  2. Blunt injuries to the abdomen in Makurdi, Benue State: Nigeria ...

    African Journals Online (AJOL)

    Splenic rupture was the commonest intra abdominal injury and was managed by splenectomy in all cases. Delay in presentation and slow reaction time were observed. These worsened the haemodynamic instability and further accounted for the high mortality rate of 26.6%. Keywords: blunt injuries, road traffic accidents

  3. Pancreatic injuries after blunt abdominal trauma: an analysis of 110 ...

    African Journals Online (AJOL)

    Background and objective. Injuries to the pancreas are uncommon, but may result in considerable morbidity and mortality. This study evaluated the management of blunt pancreatic injuries using a previously defined protocol to determine which factors predicted morbidity and mortality. Methods. The study design was a ...

  4. Gastrointestinal injuries from blunt abdominal trauma in children.

    Science.gov (United States)

    Ameh, E A; Nmadu, P T

    2004-04-01

    To determine the pattern, presentation and outcome of gastrointestinal injuries from blunt abdominal trauma in children. A retrospective study. Ahmadu Bello University Teaching Hospital, Zaria, Nigeria. Twenty one children managed for gastrointestinal injuries from blunt trauma from 1984-2002. The pattern, presentation, management and outcome of gastrointestinal injuries from blunt trauma. In the 19 year period, 1984-2002, 92 children were treated for blunt abdominal trauma, 21(23%) of who had injuries to the gastrointestinal tract. Three presenting after 24 hours had evidence of peritonitis. In six children with isolated gastrointestinal tract (GIT) injury who presented within two hours, abdominal signs were vague at initial evaluation but became marked over a few hours at repeated examination. In eight with associated intraabdominal injuries, abdominal signs were marked at initial examination and five presented with shock. Free peritoneal air was present on plain abdominal and chest radiograph in three of ten patients, dilated bowel loops in six and fluid levels in one. Diagnostic peritoneal lavage or paracentesis was positive in four patients with isolated GIT injuries and eight with associated intraabdominal injuries. There were 24 injuries in the 21 patients consisting of 15 perforations, five contusions, two seromuscular tears, and two gangrene from mesenteric injury. The small intestine was involved in 11 patients, colon six, stomach five, duodenum one and rectum one. Seven (35%) patients had associated extraabdominal injuries. Treatment consisted of simple closure of perforations, over sewing of contusions, resection and anastomosis for gangrene and repair with protective stoma for the rectal injury. One patient each developed prolonged ileus, urinary tract infection and chest infection, respectively postoperatively. Mortality was 28%, all of who had associated intraabdominal or extraabdominal injuries. Gastrointestinal injury from blunt abdominal trauma in

  5. Value of ultrasound in the evaluation of blunt abdominal trauma

    International Nuclear Information System (INIS)

    Jayanthi, Shri Krishna

    2008-01-01

    Trauma is a major cause of morbidity and mortality in an age group including from teenagers to young adults, in a male dominant proportion, resulting in great economic and social impact. Within the complex of trauma, blunt abdominal trauma (BAT) is frequent event and presents difficulty in the evaluation and management since the clinical examination shows low sensitivity and specificity. The detection of hemo peritoneum is one of the methods of evaluation of possible indirect intra-abdominal injuries, initially using direct diagnostic abdominal paracentesis and posteriorly the diagnostic peritoneal lavage, that despite the effectiveness, have drawbacks such as invasiveness and the inability of hemo peritoneum quantification and the lesion staging, resulting in non-therapeutic laparotomies. Imaging methods provide useful information in the investigation of abdominal injuries, such as conventional and contrast radiology, ultrasound (US) and computed tomography (CT), which is the best effective method, but has its own drawbacks, such as cost, accessibility, use of ionizing radiation and contrast media and the displacement of the patient to the machine. US presents itself as an alternative in the initial evaluation of these patients as noninvasive method, with lack of harmfulness, low cost, fast answer and portability. Nevertheless, this method also has its limitations, as in cases of abdominal injuries without free fluid. This study was conducted in order to establish the performance of the US in this setting, allowing to rationalise the use of CT. For this purpose we studied 163 patients treated in the ER of HC/FMUSP, with the completion of consecutive US and CT. The population fits the usual profile of trauma victims, with 83% male, 56% in the age group between 20 and 39 years and in 73% of cases victims of traffic accidents. They were brought to the service in an average time of 51 minutes, mainly stable and with satisfactory level of consciousness. US took on

  6. Concomitant aortic valve and internal mammary artery injuries in blunt chest trauma: report of a case.

    Science.gov (United States)

    Yeh, Chun-Chieh; Hsieh, Chi-Hsun; Wang, Yu-Chun; Chung, Ping-Kuei; Chen, Ray-Jade

    2009-01-01

    We report a case of concomitant injury to the aortic valve and internal mammary artery (IMA) from nonpenetrating chest trauma. To our knowledge, this is the first such case to be reported. Transcatheter arterial embolization (TAE) following diagnostic angiography offers an effective and minimally invasive treatment for traumatic IMA injuries. Because there might be an asymptomatic interval after traumatic aortic valve injuries, serial physical examinations and repeated echocardiography should be mandatory for patients with de novo heart failure after blunt chest trauma. Transesophageal echocardiography can provide a clearer image of cardiac injuries than transthoracic echocardiography, particularly if there is extensive anterior mediastinal hematoma resulting from IMA trauma.

  7. Evaluating the use and utility of noninvasive angiography in diagnosing traumatic blunt cerebrovascular injury.

    Science.gov (United States)

    Wang, Anthony C; Charters, Michael A; Thawani, Jayesh P; Than, Khoi D; Sullivan, Stephen E; Graziano, Gregory P

    2012-06-01

    Digital subtraction angiography (DSA) is the gold standard for radiographic diagnosis of blunt cerebrovascular injury (BCVI), but use of computed tomography angiography (CTA) and magnetic resonance angiography (MRA) has increased dramatically in BCVI screening. This study explores the utility, effectiveness, and cost of noninvasive CTA and MRA screening for BCVI. Medical records of 2,025 consecutive adults evaluated for acute blunt neck trauma and BCVI were reviewed retrospectively. The incidence of BCVI, level(s) of cervical injury, involvement of foramina transversaria and internal carotid canals, presence of bony dislocation or subluxation, and subsequent treatment received were assessed. Asymptomatic patients were analyzed based on fracture and injury patterns. The cost effectiveness of CTA compared with DSA and the effects of CTA sensitivity and screening yield were determined. Of reviewed patients, 196 received CTA or MRA. Thirty-eight patients (19.4%) were diagnosed with BCVI. Screening yield in patients symptomatic at presentation was 48.8%. Large-vessel internal carotid, vertebral, anterior spinal, and basilar artery occlusion were associated with a positive screen, as were concurrent stroke and spinal cord injury (p tool for BCVI screening. Symptomatic presentation was the best predictor of BCVI. Significant cost savings were realized using CTA rather than DSA, with similar effectiveness and patient outcomes. Diagnostic study, level III; economic analysis, level IV. Copyright © 2012 by Lippincott Williams & Wilkins

  8. Blunted Endogenous Opioid Release Following an Oral Amphetamine Challenge in Pathological Gamblers

    Science.gov (United States)

    Mick, Inge; Myers, Jim; Ramos, Anna C; Stokes, Paul R A; Erritzoe, David; Colasanti, Alessandro; Gunn, Roger N; Rabiner, Eugenii A; Searle, Graham E; Waldman, Adam D; Parkin, Mark C; Brailsford, Alan D; Galduróz, José C F; Bowden-Jones, Henrietta; Clark, Luke; Nutt, David J; Lingford-Hughes, Anne R

    2016-01-01

    Pathological gambling is a psychiatric disorder and the first recognized behavioral addiction, with similarities to substance use disorders but without the confounding effects of drug-related brain changes. Pathophysiology within the opioid receptor system is increasingly recognized in substance dependence, with higher mu-opioid receptor (MOR) availability reported in alcohol, cocaine and opiate addiction. Impulsivity, a risk factor across the addictions, has also been found to be associated with higher MOR availability. The aim of this study was to characterize baseline MOR availability and endogenous opioid release in pathological gamblers (PG) using [11C]carfentanil PET with an oral amphetamine challenge. Fourteen PG and 15 healthy volunteers (HV) underwent two [11C]carfentanil PET scans, before and after an oral administration of 0.5 mg/kg of d-amphetamine. The change in [11C]carfentanil binding between baseline and post-amphetamine scans (ΔBPND) was assessed in 10 regions of interest (ROI). MOR availability did not differ between PG and HV groups. As seen previously, oral amphetamine challenge led to significant reductions in [11C]carfentanil BPND in 8/10 ROI in HV. PG demonstrated significant blunting of opioid release compared with HV. PG also showed blunted amphetamine-induced euphoria and alertness compared with HV. Exploratory analysis revealed that impulsivity positively correlated with caudate baseline BPND in PG only. This study provides the first evidence of blunted endogenous opioid release in PG. Our findings are consistent with growing evidence that dysregulation of endogenous opioids may have an important role in the pathophysiology of addictions. PMID:26552847

  9. CT findings in children with blunt trauma in the spleen

    International Nuclear Information System (INIS)

    Nishiguchi, Hiroyasu; Shimizu, Toshihisa; Ohmura, Makoto; Kawai, Naoki; Tauchi, Hayato; Hayakawa, Masao; Nishio, Yoshinori; Watanabe, Shinsuke.

    1991-01-01

    We evaluated CT findings in 19 children with blunt injuries in the spleen. CT demonstrated laceration of the spleen in 7 children, rupture of the spleen in 7, and splenic hematoma in 5. Leakage of the contrast medium was observed in 3 children, of whom 1 was treated by arterial embolization. Laparotomy was performed in 3 children (15.8%) other than the 3 showing contrast medium leakage; hemostasis by compression was performed in 1 with laceration, and splenectomy in 2 with rupture. Late splenic rupture or abscess did not occur in any child. One child (5.3%) died of complicating injuries. Many of children with blunt splenic injuries can be successfully treated with conservative treatment, and CT scanning is useful for evaluating the degree of splenic injuries and complicating injuries. (author)

  10. CT findings in children with blunt trauma in the spleen

    Energy Technology Data Exchange (ETDEWEB)

    Nishiguchi, Hiroyasu; Shimizu, Toshihisa; Ohmura, Makoto; Kawai, Naoki; Tauchi, Hayato; Hayakawa, Masao; Nishio, Yoshinori (Kyoto Second Red Cross Hospital (Japan)); Watanabe, Shinsuke

    1991-09-01

    We evaluated CT findings in 19 children with blunt injuries in the spleen. CT demonstrated laceration of the spleen in 7 children, rupture of the spleen in 7, and splenic hematoma in 5. Leakage of the contrast medium was observed in 3 children, of whom 1 was treated by arterial embolization. Laparotomy was performed in 3 children (15.8%) other than the 3 showing contrast medium leakage; hemostasis by compression was performed in 1 with laceration, and splenectomy in 2 with rupture. Late splenic rupture or abscess did not occur in any child. One child (5.3%) died of complicating injuries. Many of children with blunt splenic injuries can be successfully treated with conservative treatment, and CT scanning is useful for evaluating the degree of splenic injuries and complicating injuries. (author).

  11. CT of blunt pancreatic trauma-A pictorial essay

    International Nuclear Information System (INIS)

    Venkatesh, Sudhakar Kundapur; Wan, John Mun Chin

    2008-01-01

    Blunt trauma to pancreas is uncommon and clinical features are often non-specific and unreliable leading to possible delays in diagnosis and therefore increased morbidity. CT has been established as the imaging modality of choice for the diagnosis of abdominal solid-organ injury in the blunt trauma patient. The introduction of multidetector-row CT allows for high resolution scans and multiplanar reformations that improve diagnosis. Detection of pancreatic injuries on CT requires knowledge of the subtle changes produced by pancreatic injury. The CT appearance of pancreatic injury ranges from a normal initial appearance of the pancreas to active pancreatic bleeding. Knowledge of CT signs of pancreatic trauma and a high index of suspicion is required in diagnosing pancreatic injury

  12. Blunt apical dissection during anatomic radical retropubic prostatectomy

    Directory of Open Access Journals (Sweden)

    Yacoub Saif

    2009-02-01

    Full Text Available Abstract Background Meticulous apical dissection during a radical prostatectomy is imperative to achieve desirable pathologic and quality of life outcomes. Findings We describe a novel technique using careful blunt dissection to better delineate the apex of the prostate, providing a simple means to potentially lessen positive surgical margins at the apex and promote better continence and erectile function in men undergoing an anatomic radical prostatectomy. Median operative time and blood loss were 190 minutes and 675 mL, respectively. Only 10 percent of the patients with positive surgical margins were found to have apical positive surgical margins. Ninety-three percent of patients reported no urinary leakage. Conclusion We believe our technique of isolating the DVC with blunt dissection and then ligating and transecting the DVC to be feasible approach that requires larger studies to truly confirm its utility.

  13. Physiological blunting during pregnancy extends to induced relaxation.

    Science.gov (United States)

    DiPietro, Janet A; Mendelson, Tamar; Williams, Erica L; Costigan, Kathleen A

    2012-01-01

    There is accumulating evidence that pregnancy is accompanied by hyporesponsivity to physical, cognitive, and psychological challenges. This study evaluates whether observed autonomic blunting extends to conditions designed to decrease arousal. Physiological and psychological responsivity to an 18-min guided imagery relaxation protocol in healthy pregnant women during the 32nd week of gestation (n=54) and non-pregnant women (n=28) was measured. Data collection included heart period (HP), respiratory sinus arrhythmia (RSA), tonic and phasic measures of skin conductance (SCL and NS-SCR), respiratory period (RP), and self-reported psychological relaxation. As expected, responses to the manipulation included increased HP, RSA, and RP and decreased SCL and NS-SCR, followed by post-manipulation recovery. However, responsivity was attenuated for all physiological measures except RP in pregnant women, despite no difference in self-reported psychological relaxation. Findings support non-specific blunting of physiological responsivity during pregnancy. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Multi-detector row computed tomography and blunt chest trauma

    International Nuclear Information System (INIS)

    Scaglione, Mariano; Pinto, Antonio; Pedrosa, Ivan; Sparano, Amelia; Romano, Luigia

    2008-01-01

    Blunt chest trauma is a significant source of morbidity and mortality in industrialized countries. The clinical presentation of trauma patients varies widely from one individual to another and ranges from minor reports of pain to shock. Knowledge of the mechanism of injury, the time of injury, estimates of motor vehicle accident velocity and deceleration, and evidence of associated injury to other systems are all salient features to provide for an adequate assessment of chest trauma. Multi-detector row computed tomography (MDCT) scanning and MDCT-angiography are being used more frequently in the diagnosis of patients with chest trauma. The high sensitivity of MDCT has increased the recognized spectrum of injuries. This new technology can be regarded as an extremely valuable adjunct to physical examination to recognize suspected and unsuspected blunt chest trauma

  15. MANAGEMENT OF SPLENIC INJURY AFTER BLUNT INJURY TO ABDOMEN

    Directory of Open Access Journals (Sweden)

    J. Bharath Prakash Reddy

    2016-07-01

    Full Text Available BACKGROUND The spleen is an important organ in the body’s immune system. It is the most frequently injured organ in blunt abdominal trauma. 1 Over the past several decades, diagnosis and management of splenic trauma has been evolved. The conservative, operative approach has been challenged by several reports of successful non-operative management aided by the power of modern diagnostic imaging. The aim of our prospective study was to compare non-operative management with surgery for cases of splenic injury. METHODS We conducted a prospective study of patients admitted with blunt splenic injury to our regional hospital over a three-year period (2012-2015. Haemodynamic status upon admission, FAST examination, computed tomography 2 grade of splenic tear, presence and severity of associated injuries have been taken into account to determine the treatment of choice. Therapeutic options were classified into non-operative and splenectomy. RESULTS Over a 3-year period, 24 patients were admitted with blunt splenic injury. Sixteen patients were managed operatively and eight patients non-operatively. 3,4 Non-operative management failed in one patient due to continued bleeding. The majority of grades I, II, and III splenic injuries were managed non-operatively and grades IV and V were managed operatively. Blood transfusion requirement was significantly higher among the operative group, but the operative group had a significantly longer hospital stay. Among those managed non-operatively (median age 24.5 years, a number of patients were followed up with CT scans with significant radiation exposure and unknown longterm consequences. CONCLUSION In our experience, NOM is the treatment of choice for grade I, II and III blunt splenic injuries. Splenectomy was the chosen technique in patients who met exclusion criteria for NOM, as well as for patients with grade IV and V injury.

  16. Are routine pelvic radiographs in major pediatric blunt trauma necessary?

    International Nuclear Information System (INIS)

    Lagisetty, Jyothi; Slovis, Thomas; Thomas, Ronald; Knazik, Stephen; Stankovic, Curt

    2012-01-01

    Screening pelvic radiographs to rule out pelvic fractures are routinely used for the initial evaluation of pediatric blunt trauma. Recently, the utility of routine pelvic radiographs in certain subsets of patients with blunt trauma has been questioned. There is a growing amount of evidence that shows the clinical exam is reliable enough to obviate the need for routine screening pelvic radiographs in children. To identify variables that help predict the presence or absence of pelvic fractures in pediatric blunt trauma. We conducted a retrospective study from January 2005 to January 2010 using the trauma registry at a level 1 pediatric trauma center. We analyzed all level 1 and level 2 trauma victims, evaluating history, exam and mechanism of injury for association with the presence or absence of a pelvic fracture. Of 553 level 1 and 2 trauma patients who presented during the study period, 504 were included in the study. Most of these children, 486/504 (96.4%), showed no evidence of a pelvic fracture while 18/504 (3.6%) had a pelvic fracture. No factors were found to be predictive of a pelvic fracture. However, we developed a pelvic fracture screening tool that accurately rules out the presence of a pelvic fracture P = 0.008, NPV 99, sensitivity 96, 8.98 (1.52-52.8). This screening tool combines eight high-risk clinical findings (pelvic tenderness, laceration, ecchymosis, abrasion, GCS <14, positive urinalysis, abdominal pain/tenderness, femur fracture) and five high-risk mechanisms of injury (unrestrained motor vehicle collision [MVC], MVC with ejection, MVC rollover, auto vs. pedestrian, auto vs. bicycle). Pelvic fractures in pediatric major blunt trauma can reliably be ruled out by using our pelvic trauma screening tool. Although no findings accurately identified the presence of a pelvic fracture, the screening tool accurately identified the absence of a fracture, suggesting that pelvic radiographs are not warranted in this subset of patients. (orig.)

  17. Diagnostic Accuracy of Secondary Ultrasound Exam in Blunt Abdominal Trauma

    International Nuclear Information System (INIS)

    Rajabzadeh Kanafi, Alireza; Giti, Masoumeh; Gharavi, Mohammad Hossein; Alizadeh, Ahmad; Pourghorban, Ramin; Shekarchi, Babak

    2014-01-01

    In stable patients with blunt abdominal trauma, accurate diagnosis of visceral injuries is crucial. To determine whether repeating ultrasound exam will increase the sensitivity of focused abdominal sonography for trauma (FAST) through revealing additional free intraperitoneal fluid in patients with blunt abdominal trauma. We performed a prospective observational study by performing primary and secondary ultrasound exams in blunt abdominal trauma patients. All ultrasound exams were performed by four radiology residents who had the experience of more than 400 FAST exams. Five routine intraperitoneal spaces as well as the interloop space were examined by ultrasound in order to find free fluid. All patients who expired or were transferred to the operating room before the second exam were excluded from the study. All positive ultrasound results were compared with intra-operative and computed tomography (CT) findings and/or the clinical status of the patients. Primary ultrasound was performed in 372 patients; 61 of them did not undergo secondary ultrasound exam; thus, were excluded from the study.Three hundred eleven patients underwent both primary and secondary ultrasound exams. One hundred and two of all patients were evaluated by contrast enhanced CT scan and 31 underwent laparotomy. The sensitivity of ultrasound exam in detecting intraperitoneal fluid significantly increased from 70.7% for the primary exam to 92.7% for the secondary exam. Examining the interloop space significantly improved the sensitivity of ultrasonography in both primary (from 36.6% to 70.7%) and secondary (from 65.9% to 92.7%) exams. Performing a secondary ultrasound exam in stable blunt abdominal trauma patients and adding interloop space scan to the routine FAST exam significantly increases the sensitivity of ultrasound in detecting intraperitoneal free fluid

  18. Are routine pelvic radiographs in major pediatric blunt trauma necessary?

    Science.gov (United States)

    Lagisetty, Jyothi; Slovis, Thomas; Thomas, Ronald; Knazik, Stephen; Stankovic, Curt

    2012-07-01

    Screening pelvic radiographs to rule out pelvic fractures are routinely used for the initial evaluation of pediatric blunt trauma. Recently, the utility of routine pelvic radiographs in certain subsets of patients with blunt trauma has been questioned. There is a growing amount of evidence that shows the clinical exam is reliable enough to obviate the need for routine screening pelvic radiographs in children. To identify variables that help predict the presence or absence of pelvic fractures in pediatric blunt trauma. We conducted a retrospective study from January 2005 to January 2010 using the trauma registry at a level 1 pediatric trauma center. We analyzed all level 1 and level 2 trauma victims, evaluating history, exam and mechanism of injury for association with the presence or absence of a pelvic fracture. Of 553 level 1 and 2 trauma patients who presented during the study period, 504 were included in the study. Most of these children, 486/504 (96.4%), showed no evidence of a pelvic fracture while 18/504 (3.6%) had a pelvic fracture. No factors were found to be predictive of a pelvic fracture. However, we developed a pelvic fracture screening tool that accurately rules out the presence of a pelvic fracture P = 0.008, NPV 99, sensitivity 96, 8.98 (1.52-52.8). This screening tool combines eight high-risk clinical findings (pelvic tenderness, laceration, ecchymosis, abrasion, GCS blunt trauma can reliably be ruled out by using our pelvic trauma screening tool. Although no findings accurately identified the presence of a pelvic fracture, the screening tool accurately identified the absence of a fracture, suggesting that pelvic radiographs are not warranted in this subset of patients.

  19. Blunt Facial Trauma Causing Isolated Optic Nerve Hematoma

    Directory of Open Access Journals (Sweden)

    R. Parab

    2013-01-01

    Full Text Available Traumatic optic neuropathy is an uncommon, yet serious, result of facial trauma. The authors present a novel case of a 59-year-old gentleman who presented with an isolated blunt traumatic left optic nerve hematoma causing vision loss. There were no other injuries or fractures to report. This case highlights the importance of early recognition of this rare injury and reviews the current literature and management of traumatic optic neuropathy.

  20. Physiological blunting during pregnancy extends to induced relaxation

    OpenAIRE

    DiPietro, Janet A.; Mendelson, Tamar; Williams, Erica L.; Costigan, Kathleen A.

    2011-01-01

    There is accumulating evidence that pregnancy is accompanied by hyporesponsivity to physical, cognitive, and psychological challenges. This study evaluates whether observed autonomic blunting extends to conditions designed to decrease arousal. Physiological and psychological responsivity to an 18-minute guided imagery relaxation protocol in healthy pregnant women during the 32nd week of gestation (n = 54) and non-pregnant women (n = 28) was measured. Data collection included heart period (HP)...

  1. Penetrating cardiac injuries in blunt chest wall trauma.

    Science.gov (United States)

    Kanchan, Tanuj; Menezes, Ritesh G; Sirohi, Parmendra

    2012-08-01

    The present photocase illustrates the possible mechanism of direct cardiac injuries from broken sharp jagged fractured ends of ribs in blunt force trauma to the chest in run over traffic mishaps. We propose that the projecting fractured ends of the ribs penetrate the underlying thoracic organs due to the transient phenomenon of deformation of chest cavity under pressure in run over traffic mishaps. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  2. Homicide by blunt force in 2 Scandinavian capitals

    DEFF Research Database (Denmark)

    Rogde, Sidsel; Hougen, Hans P; Poulsen, Klaus

    2003-01-01

    In the Oslo and Copenhagen areas, 77 instances of blunt force homicides were committed from 1985-1994, accounting for 18% of all homicides in that 10-year period. Fifty-four (70%) of the victims were male, often killed by an acquaintance during a fight. Almost 70% of the female victims were kille...... were battered children. Many of the victims with a blood alcohol level of 0 turned out to have lived for some time after the injury....

  3. Are routine pelvic radiographs in major pediatric blunt trauma necessary?

    Energy Technology Data Exchange (ETDEWEB)

    Lagisetty, Jyothi [Memorial Hermann Medical Center, Emergency Medicine Department, Houston, TX (United States); Slovis, Thomas [Wayne State University School of Medicine, Department of Radiology, Pediatric Imaging, Children' s Hospital of Michigan, Detroit, MI (United States); Thomas, Ronald [Children' s Hospital of Michigan, Wayne State University of Medicine, Department of Pediatrics, Detroit, MI (United States); Knazik, Stephen; Stankovic, Curt [Wayne State University of Medicine, Division of Emergency Medicine, Children' s Hospital of Michigan, Detroit, MI (United States)

    2012-07-15

    Screening pelvic radiographs to rule out pelvic fractures are routinely used for the initial evaluation of pediatric blunt trauma. Recently, the utility of routine pelvic radiographs in certain subsets of patients with blunt trauma has been questioned. There is a growing amount of evidence that shows the clinical exam is reliable enough to obviate the need for routine screening pelvic radiographs in children. To identify variables that help predict the presence or absence of pelvic fractures in pediatric blunt trauma. We conducted a retrospective study from January 2005 to January 2010 using the trauma registry at a level 1 pediatric trauma center. We analyzed all level 1 and level 2 trauma victims, evaluating history, exam and mechanism of injury for association with the presence or absence of a pelvic fracture. Of 553 level 1 and 2 trauma patients who presented during the study period, 504 were included in the study. Most of these children, 486/504 (96.4%), showed no evidence of a pelvic fracture while 18/504 (3.6%) had a pelvic fracture. No factors were found to be predictive of a pelvic fracture. However, we developed a pelvic fracture screening tool that accurately rules out the presence of a pelvic fracture P = 0.008, NPV 99, sensitivity 96, 8.98 (1.52-52.8). This screening tool combines eight high-risk clinical findings (pelvic tenderness, laceration, ecchymosis, abrasion, GCS <14, positive urinalysis, abdominal pain/tenderness, femur fracture) and five high-risk mechanisms of injury (unrestrained motor vehicle collision [MVC], MVC with ejection, MVC rollover, auto vs. pedestrian, auto vs. bicycle). Pelvic fractures in pediatric major blunt trauma can reliably be ruled out by using our pelvic trauma screening tool. Although no findings accurately identified the presence of a pelvic fracture, the screening tool accurately identified the absence of a fracture, suggesting that pelvic radiographs are not warranted in this subset of patients. (orig.)

  4. Pneumoperitoneum in a patient with pneumothorax and blunt neck trauma

    Directory of Open Access Journals (Sweden)

    Suhail Yaqoob Hakim

    2014-01-01

    CONCLUSION: Free air in the abdomen after blunt traumatic neck injury is very rare. If pneumoperitoneum is suspected in the presence of pneumothorax, exploratory laparotomy should be performed to rule out intraabdominal injury. As, there is no consensus for this plan yet, further prospective studies are warrant. Conservative management for pneumoperitoneum in the absence of viscus perforation is still a safe option in carefully selected cases.

  5. Development of a murine model of blunt hepatic trauma.

    Science.gov (United States)

    Nemzek-Hamlin, Jean A; Hwang, Haejin; Hampel, Joseph A; Yu, Bi; Raghavendran, Krishnan

    2013-10-01

    Despite the prevalence of blunt hepatic trauma in humans, there are few rodent models of blunt trauma that can be used to study the associated inflammatory responses. We present a mouse model of blunt hepatic trauma that was created by using a cortical contusion device. Male mice were anesthetized with ketamine-xylazine-buprenorphine and placed in left lateral recumbency. A position of 2 mm ventral to the posterior axillary line and 5 mm caudal to the costal margin on the right side was targeted for impact. An impact velocity of 6 m/s and a piston depth of 12 mm produced a consistent pattern of hepatic injury with low mortality. All mice that recovered from anesthesia survived without complication for the length of the study. Mice were euthanized at various time points (n = 5 per group) until 7 d after injury for gross examination and collection of blood and peritoneal lavage fluids. Some mice were reanesthetized for serial monitoring of hepatic lesions via MRI. At 2 h after trauma, mice consistently displayed laceration, hematoma, and discoloration of the right lateral and caudate liver lobes, with intraabdominal hemorrhage but no other gross injuries. Blood and peritoneal lavage fluid were collected from all mice for cytokine analysis. At 2 h after trauma, there were significant increases in plasma IL10 as well as peritoneal lavage fluid IL6 and CXCL1/KC; however, these levels decreased within 24 h. At 7 d after trauma, the mice had regained body weight, and the hepatic lesions, which initially had increased in size during the first 48 h, had returned to their original size. In summary, this technique produced a reliable, low mortality, murine model that recreates features of blunt abdominal liver injury in human subjects with similar acute inflammatory response.

  6. Thyroid gland rupture caused by blunt trauma to the neck

    OpenAIRE

    Hara, Hirotaka; Hirose, Yoshinobu; Yamashita, Hiroshi

    2016-01-01

    Background Thyroid rupture following blunt trauma is extremely rare, and neck pain without swelling may be the only presenting symptom. However, hemorrhage and hematoma subsequently causes severe tracheal compression and respiratory distress. Case presentation A 71-year-old Japanese woman visited our emergency room with a complaint of increasing right-sided neck pain at the thyroid cartilage level after she tripped and accidentally hit her neck against a pole 3?h back. On admission, her vital...

  7. Non-operative management of adult blunt splenic injuries

    Institute of Scientific and Technical Information of China (English)

    YANG Jun; GAO Jin-mou; Jean-Claude Baste

    2006-01-01

    Objective: To investigate the indication of nonoperative management of adult blunt splenic injuries.Methods: A retrospective review was performed on all adult patients (age > 15 years ) with blunt splenic injuries admitted to the department of vascular surgery of Pellegrin hospital in France from 1999 to 2003. We managed splenic injuries non-operatively in all appropriate patients without regard to age.Results: During the 4 years, 54 consecutive adult patients with blunt splenic injuries were treated in the hospital. A total of 27 patients with stable hemodynamic status were treated non-operatively at first, of which 2 patients were failed to non-operative treatment. The successful percentage of non-operative management was 92.6 %. In the 54 patients, 7 of 8 patients older than 55 years were treated with non-operative management. Two cases developing postoperatively subphrenic infection were healed by proper treatment. In the series, there was no death.Conclusions: Non-operative management of low-grade splenic injuries can be accomplished with an acceptable low-failure rate. If the clinical and laboratory parameters difficult for surgeons to make decisions, they can depend on Resciniti' s CT (computed tomography)scoring system to select a subset of adults with splenic trauma who are excellent candidates for a trial of nonoperative management. The patients older than 55 years are not absolutely inhibited to receive non-operative management.

  8. A rare case of traumatic chylothorax after blunt thoracic trauma

    Directory of Open Access Journals (Sweden)

    Spasić Marko

    2017-01-01

    Full Text Available Introduction. Chylothorax is an accumulation of chyle in the pleural cavity due to a disruption of the thoracic duct. Traumatic chylothoraces are usually a result of a penetrating trauma and disruption of the thoracic duct, but blunt traumatic chylothorax is a rare condition. The aim of this paper is to present a rare case of traumatic chylothorax after blunt thoracic trauma. Case Outline. We present a case of traumatic chylothorax after blunt thoracic trauma in a patient injured in a motor vehicle accident. The patient had a right-sided fracture of rib XI, hydropneumothorax, lung contusion, and signs of pneumomediastinum. We performed thoracic drainage, but a few days later, according to the increase of amount of the fluid daily drained, and the confirmation of laboratory findings of the analyzed fluid, we made a diagnosis of chylothorax and the patient underwent a thoracotomy, where we sutured the thoracic duct. Conclusion. Chylothorax should be considered in patients after chest trauma if they develop a milky pleural effusion. Analysis of pleural fluid and level of triglycerides is important for the diagnosis and treatment of chylothorax. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III41007

  9. Diagnostic imaging of blunt abdominal trauma in pediatric patients.

    Science.gov (United States)

    Miele, Vittorio; Piccolo, Claudia Lucia; Trinci, Margherita; Galluzzo, Michele; Ianniello, Stefania; Brunese, Luca

    2016-05-01

    Trauma is a leading cause of morbidity and mortality in childhood, and blunt trauma accounts for 80-90 % of abdominal injuries. The mechanism of trauma is quite similar to that of the adults, but there are important physiologic differences between children and adults in this field, such as the smaller blood vessels and the high vasoconstrictive response, leading to the spreading of a non-operative management. The early imaging of children undergoing a low-energy trauma can be performed by CEUS, a valuable diagnostic tool to demonstrate solid organ injuries with almost the same sensitivity of CT scans; nevertheless, as for as urinary tract injuries, MDCT remains still the technique of choice, because of its high sensitivity and accuracy, helping to discriminate between an intra-peritoneal form a retroperitoneal urinary leakage, requiring two different managements. The liver is the most common organ injured in blunt abdominal trauma followed by the spleen. Renal, pancreatic, and bowel injuries are quite rare. In this review we present various imaging findings of blunt abdominal trauma in children.

  10. Computed tomography and nonoperative treatment for blunt abdominal trauma

    International Nuclear Information System (INIS)

    Watanabe, Shinsuke; Ishi, Takashi; Kamachi, Masahiro; Takahashi, Toshio.

    1990-01-01

    Studies were undertaken to determine if computed tomography (CT) could reliably assist physical examination in the initial assessment of blunt abdominal trauma, and also to examine how various abdominal injuries were managed with the guidance of CT. A total of 255 patients underwent emergency abdominal CT following blunt abdominal trauma over a period of seven years. One hundred and fifty two patients had abnormal CT scans, including 58 hepatic, 36 renal, 25 splenic and 9 pancreatic injuries as well as 67 patients with intra-abdominal hemorrhage and 21 patients with free abdominal air. A comparative study on the detection of pneumoperitoneum revealed CT to be far superior to plain radiography. One hundred and three patients had normal CT scans, all of whom were managed nonoperatively, except for three false-negative cases and two nontherapeutic cases. The patients with injury to the parenchymal organs were given nonoperative treatment if they had stable vital signs and no evidence of associated injuries demanding immediate surgery and the majority of these patients were managed well nonoperatively. CT was thus found to be a useful adjunct in the management of victims of blunt abdominal trauma, since in a rapid and noninvasive fashion, CT accurately defined the extent of parenchymal organ injury and also disclosed any other abdominal injuries. (author)

  11. Computed tomography and nonoperative treatment for blunt abdominal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Shinsuke; Ishi, Takashi; Kamachi, Masahiro [Saiseikai Shiga Hospital, Shiga (Japan); Takahashi, Toshio

    1990-01-01

    Studies were undertaken to determine if computed tomography (CT) could reliably assist physical examination in the initial assessment of blunt abdominal trauma, and also to examine how various abdominal injuries were managed with the guidance of CT. A total of 255 patients underwent emergency abdominal CT following blunt abdominal trauma over a period of seven years. One hundred and fifty two patients had abnormal CT scans, including 58 hepatic, 36 renal, 25 splenic and 9 pancreatic injuries as well as 67 patients with intra-abdominal hemorrhage and 21 patients with free abdominal air. A comparative study on the detection of pneumoperitoneum revealed CT to be far superior to plain radiography. One hundred and three patients had normal CT scans, all of whom were managed nonoperatively, except for three false-negative cases and two nontherapeutic cases. The patients with injury to the parenchymal organs were given nonoperative treatment if they had stable vital signs and no evidence of associated injuries demanding immediate surgery and the majority of these patients were managed well nonoperatively. CT was thus found to be a useful adjunct in the management of victims of blunt abdominal trauma, since in a rapid and noninvasive fashion, CT accurately defined the extent of parenchymal organ injury and also disclosed any other abdominal injuries. (author).

  12. Factors Associated with ICU Admission following Blunt Chest Trauma

    Directory of Open Access Journals (Sweden)

    Andrea Bellone

    2016-01-01

    Full Text Available Background. Blunt chest wall trauma accounts for over 10% of all trauma patients presenting to emergency departments worldwide. When the injury is not as severe, deciding which blunt chest wall trauma patients require a higher level of clinical input can be difficult. We hypothesized that patient factors, injury patterns, analgesia, postural condition, and positive airway pressure influence outcomes. Methods. The study population consisted of patients hospitalized with at least 3 rib fractures (RF and at least one pulmonary contusion and/or at least one pneumothorax lower than 2 cm. Results. A total of 140 patients were retrospectively analyzed. Ten patients (7.1% were admitted to intensive care unit (ICU within the first 72 hours, because of deterioration of the clinical conditions and gas exchange with worsening of chest X-ray/thoracic ultrasound/chest computed tomography. On univariable analysis and multivariable analysis, obliged orthopnea (p=0.0018 and the severity of trauma score (p<0.0002 were associated with admission to ICU. Conclusions. Obliged orthopnea was an independent predictor of ICU admission among patients incurring non-life-threatening blunt chest wall trauma. The main therapeutic approach associated with improved outcome is the prevention of pulmonary infections due to reduced tidal volume, namely, upright postural condition and positive airway pressure.

  13. Nonoperative management of blunt hepatic trauma: A systematic review.

    Science.gov (United States)

    Boese, Christoph Kolja; Hackl, Michael; Müller, Lars Peter; Ruchholtz, Steffen; Frink, Michael; Lechler, Philipp

    2015-10-01

    Nonoperative management (NOM) has become the standard treatment in hemodynamically stable patients with blunt hepatic injuries. While the reported overall success rates of NOM are excellent, there is a lack of consensus regarding the risk factors predicting the failure of NOM. The aim of this systematic review was to identify the incidence and prognostic factors for failure of NOM in adult patients with blunt hepatic trauma. Prospective studies reporting prognostic factors for the failure of nonoperative treatment of blunt liver injuries were identified by searching MEDLINE and the Cochrane Central Register of Controlled Trials. We screened 798 titles and abstracts, of which 8 single-center prospective observational studies, reporting 410 patients, were included in the qualitative and quantitative synthesis. No randomized controlled trials were found. The pooled failure rate of NOM was 9.5% (0-24%). Twenty-six prognostic factors predicting the failure of NOM were reported, of which six reached statistical significance in one or more studies: blood pressure (p hepatic injuries. Systematic review, level III.

  14. Primary hepatic artery embolization in pediatric blunt hepatic trauma.

    Science.gov (United States)

    Ong, Caroline C P; Toh, Luke; Lo, Richard H G; Yap, Te-Lu; Narasimhan, Kannan

    2012-12-01

    Non-operative management of isolated blunt hepatic trauma is recommended except when hemodynamic instability requires immediate laparotomy. Hepatic artery angioembolization is increasingly used for hepatic injuries with ongoing bleeding as demonstrated by contrast extravasation on the CT scan. It is used primarily or after laparotomy to control ongoing hemorrhage. Hepatic angioembolization as part of multimodality management of hepatic trauma is reported mainly in adults, with few pediatric case reports. We describe our institution experience with primary pediatric hepatic angioembolization and review the literature with regard to indications and complications. Two cases (3 and 8 years old), with high-grade blunt hepatic injuries with contrast extravasation on the CT scan were successfully managed by emergency primary hepatic angioembolization with minimal morbidity and avoided laparotomy. To date, the only reports of pediatric hepatic angioembolization for trauma are 5 cases for acute bleeding and 15 delayed cases for pseudoaneurysm. The role of hepatic angioembolization in the presence of an arterial blush on CT in adults is accepted, but contested in a pediatric series, despite higher transfusion rate and mortality rate. We propose that hepatic angioembolization should be considered adjunct treatment, in lieu of, or in addition to emergency laparotomy for hemostasis in pediatric blunt hepatic injury. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Arterial phase CT for the detection of splenic injuries in blunt trauma: would it improve clinical outcomes?

    Science.gov (United States)

    Corwin, Michael T; Fananapazir, Ghaneh; Lamba, Ramit; Salcedo, Edgardo S; Holmes, James F

    2016-01-01

    To determine if the addition of an arterial phase abdominal computed tomography (CT) improves clinical outcomes in patients with blunt splenic injuries. Retrospective review of patients who underwent CT of the abdomen revealing splenic injuries. Clinical management in these patients was determined. Fifty-one of three thousand five hundred twenty-five patients had splenic injuries. Twenty-five patients underwent nonsurgical management, and 3 failed. The theoretical additional arterial phase resulted in a 62% increase in mean effective dose compared to the portal venous phase alone. Routine use of arterial phase CT in blunt trauma patients may not be warranted as there is minimal improvement in outcomes. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Strategic Designs: Lessons from Leading Edge Small Urban High Schools

    Science.gov (United States)

    Shields, Regis Anne; Miles, Karen Hawley

    2008-01-01

    Education Resource Strategies (ERS) works with school and district leaders to help them more strategically use resources--people, time, and money--to improve student performance. They have found that many school districts begin creating small high schools without a clear sense of how much they will spend or how to ensure that small schools…

  17. Editorial "Strategic management and social media: the leading edge"

    NARCIS (Netherlands)

    Olivas-Lujan, Miguel R.; Bondarouk, Tatiana; Olivas-Lujan, M.R.; Bondarouk, T.V.

    2013-01-01

    This volume is a bridge made up by exemplary contributions linking strategic perspectives with the use of social media — the most recent family of technologies that are evolving rapidly and exciting businesses as well as all sectors of society. Social media, defined by Kaplan and Haenlein (2010, p.

  18. Marketing equipment at the leading edge of technology

    International Nuclear Information System (INIS)

    Rapp, K.

    1992-01-01

    This chapter describes the involvement of a gas utility, Brooklyn Union Gas Company, in the marketing of small cogeneration modules and as project managers for their installation. The topics of the chapter include a background of Brooklyn Union, a description of the TOTEM 15 kW module, the economic impact f the TOTEM on the market for natural gas, and the economics of marketing and servicing the TOTEM

  19. Pulsed Film Cooling on a Turbine Blade Leading Edge

    Science.gov (United States)

    2009-09-01

    Iota One controller were used to control the pulsed coolant. The solenoid i The water was encased...Turbine, Unsteady, Pulsed, Heat Transfer 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF

  20. Leading Edge. Volume 7, Issue Number 4, 2012

    Science.gov (United States)

    2012-01-01

    Trek popular- ized the notion of using DE for weapons in years past, today— through persistent DEW RDT&E— Navy leadership is realizing the great...supporting platforms. The Pictured here is the National Aeronautics and Space Administra- tion / National Oceanic and Atmospheric Administration ( NASA ...procured by Boeing Launch Services on 4 March 2010. Built by Boeing Space and Intelli- gence Systems, GOES-P will provide NOAA and NASA scien- tists

  1. Computers Put a Journalism School on Technology's Leading Edge.

    Science.gov (United States)

    Blum, Debra E.

    1992-01-01

    Since 1985, the University of Missouri at Columbia's School of Journalism has been developing a high-technology environment for student work, including word processing, electronic imaging, networked personal computers, and telecommunications. Some faculty worry that the emphasis on technology may overshadow the concepts, principles, and substance…

  2. Computing at the leading edge: Research in the energy sciences

    Energy Technology Data Exchange (ETDEWEB)

    Mirin, A.A.; Van Dyke, P.T. [eds.

    1994-02-01

    The purpose of this publication is to highlight selected scientific challenges that have been undertaken by the DOE Energy Research community. The high quality of the research reflected in these contributions underscores the growing importance both to the Grand Challenge scientific efforts sponsored by DOE and of the related supporting technologies that the National Energy Research Supercomputer Center (NERSC) and other facilities are able to provide. The continued improvement of the computing resources available to DOE scientists is prerequisite to ensuring their future progress in solving the Grand Challenges. Titles of articles included in this publication include: the numerical tokamak project; static and animated molecular views of a tumorigenic chemical bound to DNA; toward a high-performance climate systems model; modeling molecular processes in the environment; lattice Boltzmann models for flow in porous media; parallel algorithms for modeling superconductors; parallel computing at the Superconducting Super Collider Laboratory; the advanced combustion modeling environment; adaptive methodologies for computational fluid dynamics; lattice simulations of quantum chromodynamics; simulating high-intensity charged-particle beams for the design of high-power accelerators; electronic structure and phase stability of random alloys.

  3. Leading Edge. Volume 7, Number 3. Systems Safety Engineering

    Science.gov (United States)

    2010-01-01

    foods were not always safe to eat given the sanitary conditions of the day. In 1943, the psychologist Abraham Maslow proposed a five-level... hierarchy of basic human needs, and safety was number two on this list. System safety is a specialized and formalized extension of our in- herent drive for...factors, hazards, mishaps, and ef- fects. The following is an example of each element within the hierarchy : An exposed sharp edge in a relay cabi- net

  4. A high-performance, low-cost, leading edge discriminator

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 65; Issue 2 ... commercial discriminators. A low-cost discriminator is an essential requirement of the GRAPES-3 experiment where a large number of discriminator channels are used.

  5. Leading Edge Asynchronous Propeller (LEAPTech) Distributed Electric Propulsion (DEP) Concept

    Data.gov (United States)

    National Aeronautics and Space Administration — The "Semi-Tandem Electric Distributed Wing Zip Aviation Advanced Concept Project" was renamed to LEAPTech DEP to better align with the content of the work. This...

  6. Computing at the leading edge: Research in the energy sciences

    International Nuclear Information System (INIS)

    Mirin, A.A.; Van Dyke, P.T.

    1994-01-01

    The purpose of this publication is to highlight selected scientific challenges that have been undertaken by the DOE Energy Research community. The high quality of the research reflected in these contributions underscores the growing importance both to the Grand Challenge scientific efforts sponsored by DOE and of the related supporting technologies that the National Energy Research Supercomputer Center (NERSC) and other facilities are able to provide. The continued improvement of the computing resources available to DOE scientists is prerequisite to ensuring their future progress in solving the Grand Challenges. Titles of articles included in this publication include: the numerical tokamak project; static and animated molecular views of a tumorigenic chemical bound to DNA; toward a high-performance climate systems model; modeling molecular processes in the environment; lattice Boltzmann models for flow in porous media; parallel algorithms for modeling superconductors; parallel computing at the Superconducting Super Collider Laboratory; the advanced combustion modeling environment; adaptive methodologies for computational fluid dynamics; lattice simulations of quantum chromodynamics; simulating high-intensity charged-particle beams for the design of high-power accelerators; electronic structure and phase stability of random alloys

  7. Simulating Bird Strike on Aircraft Composite Wing Leading Edge.

    OpenAIRE

    Ericsson, Max

    2012-01-01

    In this master thesis project the possibility to model the response of a wing when subjected to bird strike using finite elements is analyzed. Since this transient event lasts only a few milliseconds the used solution method is explicit time integration. The wing is manufactured using carbon fiber laminate. Carbon fiber laminates have orthotropic material properties with different stiffness in different directions. Accordingly, there are damage mechanisms not considered when using metal that ...

  8. Noise Radiation From a Leading-Edge Slat

    Science.gov (United States)

    Lockard, David P.; Choudhari, Meelan M.

    2009-01-01

    This paper extends our previous computations of unsteady flow within the slat cove region of a multi-element high-lift airfoil configuration, which showed that both statistical and structural aspects of the experimentally observed unsteady flow behavior can be captured via 3D simulations over a computational domain of narrow spanwise extent. Although such narrow domain simulation can account for the spanwise decorrelation of the slat cove fluctuations, the resulting database cannot be applied towards acoustic predictions of the slat without invoking additional approximations to synthesize the fluctuation field over the rest of the span. This deficiency is partially alleviated in the present work by increasing the spanwise extent of the computational domain from 37.3% of the slat chord to nearly 226% (i.e., 15% of the model span). The simulation database is used to verify consistency with previous computational results and, then, to develop predictions of the far-field noise radiation in conjunction with a frequency-domain Ffowcs-Williams Hawkings solver.

  9. Cecal ligation and puncture followed by MRSA pneumonia increases mortality in mice and blunts production of local and systemic cytokines

    Science.gov (United States)

    Jung, Enjae; Perrone, Erin E.; Liang, Zhe; Breed, Elise R.; Dominguez, Jessica A.; Clark, Andrew T.; Fox, Amy C.; Dunne, W. Michael; Burd, Eileen M.; Farris, Alton B.; Hotchkiss, Richard S.; Coopersmith, Craig M.

    2011-01-01

    Mortality in the ICU frequently results from the synergistic effect of two temporally-distinct infections. This study examined the pathophysiology of a new model of intraabdominal sepsis followed by methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. Mice underwent cecal ligation and puncture (CLP) or sham laparotomy followed three days later by an intratracheal injection of MRSA or saline. Both CLP/saline and sham/MRSA mice had 100% survival while animals with CLP followed by MRSA pneumonia had 67% seven-day survival. Animals subjected to CLP/MRSA had increased bronchoalveolar lavage (BAL) concentrations of MRSA compared to sham/MRSA animals. Animals subjected to sham/MRSA pneumonia had increased BAL levels of IL-6, TNF-α, and G-CSF compared to those given intratracheal saline while CLP/MRSA mice had a blunted local inflammatory response with markedly decreased cytokine levels. Similarly, animals subjected to CLP/saline had increased peritoneal lavage levels of IL-6 and IL-1β compared to those subjected to sham laparotomy while this response was blunted in CLP/MRSA mice. Systemic cytokines were upregulated in both CLP/saline and sham/MRSA mice, and this was blunted by the combination of CLP/MRSA. In contrast, no synergistic effect on pneumonia severity, white blood cell count or lymphocyte apoptosis was identified in CLP/MRSA mice compared to animals with either insult in isolation. These results indicate that a clinically relevant model of CLP followed by MRSA pneumonia causes higher mortality than could have been predicted from studying either infection in isolation, and this was associated with a blunted local (pulmonary and peritoneal) and systemic inflammatory response and decreased ability to clear infection. PMID:21937950

  10. Positive FAST without hemoperitoneum due to fluid resuscitation in blunt trauma.

    Science.gov (United States)

    Slutzman, Jonathan E; Arvold, Lisa A; Rempell, Joshua S; Stone, Michael B; Kimberly, Heidi H

    2014-10-01

    The focused assessment with sonography in trauma (FAST) examination is an important screening tool in the evaluation of blunt trauma patients. To describe a case of a hemodynamically unstable polytrauma patient with positive FAST due to fluid resuscitation after blunt trauma. We describe a case of a hemodynamically unstable polytrauma patient who underwent massive volume resuscitation prior to transfer from a community hospital to a trauma center. On arrival at the receiving institution, the FAST examination was positive for free intraperitoneal fluid, but no hemoperitoneum or significant intra-abdominal injuries were found during laparotomy. In this case, it is postulated that transudative intraperitoneal fluid secondary to massive volume resuscitation resulted in a positive FAST examination. This case highlights potential issues specific to resuscitated trauma patients with prolonged transport times. Further study is likely needed to assess what changes, if any, should be made in algorithms to address the effect of prior resuscitative efforts on the test characteristics of the FAST examination. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Outcome of Blunt Abdominal Traumas with Stable Hemodynamic and Positive FAST Findings

    Directory of Open Access Journals (Sweden)

    Firooz Behboodi

    2016-04-01

    Full Text Available Introduction: Focused assessment with sonography for trauma (FAST is a highly effective first screening tool for initial classification of abdominal trauma patients. The present study was designed to evaluate the outcome of patients with blunt abdominal trauma and positive FAST findings. Methods: The present prospective cross-sectional study was done on patients over 7 years old with normal abdominal examination, positive FAST findings, and available abdominopelvic computed tomography (CT scan findings. The frequency of need for laparotomy as well as its probable risk factors were calculated. Results: 180 patients were enrolled (mean age: 28.0 ± 11.5 years; 76.7% male. FAST findings were confirmed by abdominopelvic CT scan in only 124 (68.9% cases. Finally, 12 (6.6% patients needed laparotomy. Mean age of those in need of laparotomy was significantly higher than others (36.75 ± 11.37 versus 27.34 ± 11.37, p = 0.006. Higher grading of spleen (p = 0.001 and hepatic (p = 0.038 ruptures increased the probability of need for laparotomy. Conclusion: 68.9% of the positive FAST findings in patients with blunt abdominal trauma and stable hemodynamics was confirmed by abdominopelvic CT scan and only 6.6% needed laparotomy. Simultaneous presence of free fluid and air in the abdominal area, old age, and higher grading o solid organ injuries were factors that had a significant correlation with need for laparotomy.

  12. Outcome of Blunt Abdominal Traumas with Stable Hemodynamic and Positive FAST Findings.

    Science.gov (United States)

    Behboodi, Firooz; Mohtasham-Amiri, Zahra; Masjedi, Navid; Shojaie, Reza; Sadri, Peyman

    2016-01-01

    Focused assessment with sonography for trauma (FAST) is a highly effective first screening tool for initial classification of abdominal trauma patients. The present study was designed to evaluate the outcome of patients with blunt abdominal trauma and positive FAST findings. The present prospective cross-sectional study was done on patients over 7 years old with normal abdominal examination, positive FAST findings, and available abdominopelvic computed tomography (CT) scan findings. The frequency of need for laparotomy as well as its probable risk factors were calculated. 180 patients were enrolled (mean age: 28.0 ± 11.5 years; 76.7% male). FAST findings were confirmed by abdominopelvic CT scan in only 124 (68.9%) cases. Finally, 12 (6.6%) patients needed laparotomy. Mean age of those in need of laparotomy was significantly higher than others (36.75 ± 11.37 versus 27.34 ± 11.37, p = 0.006). Higher grading of spleen (p = 0.001) and hepatic (p = 0.038) ruptures increased the probability of need for laparotomy. 68.9% of the positive FAST findings in patients with blunt abdominal trauma and stable hemodynamics was confirmed by abdominopelvic CT scan and only 6.6% needed laparotomy. Simultaneous presence of free fluid and air in the abdominal area, old age, and higher grading o solid organ injuries were factors that had a significant correlation with need for laparotomy.

  13. Wind-Tunnel Investigations of Blunt-Body Drag Reduction Using Forebody Surface Roughness

    Science.gov (United States)

    Whitmore, Stephen A.; Sprague, Stephanie; Naughton, Jonathan W.; Curry, Robert E. (Technical Monitor)

    2001-01-01

    This paper presents results of wind-tunnel tests that demonstrate a novel drag reduction technique for blunt-based vehicles. For these tests, the forebody roughness of a blunt-based model was modified using micomachined surface overlays. As forebody roughness increases, boundary layer at the model aft thickens and reduces the shearing effect of external flow on the separated flow behind the base region, resulting in reduced base drag. For vehicle configurations with large base drag, existing data predict that a small increment in forebody friction drag will result in a relatively large decrease in base drag. If the added increment in forebody skin drag is optimized with respect to base drag, reducing the total drag of the configuration is possible. The wind-tunnel tests results conclusively demonstrate the existence of a forebody dragbase drag optimal point. The data demonstrate that the base drag coefficient corresponding to the drag minimum lies between 0.225 and 0.275, referenced to the base area. Most importantly, the data show a drag reduction of approximately 15% when the drag optimum is reached. When this drag reduction is scaled to the X-33 base area, drag savings approaching 45,000 N (10,000 lbf) can be realized.

  14. Computation of hypersonic axisymmetric flows of equilibrium gas over blunt bodies

    International Nuclear Information System (INIS)

    Hejranfar, K.; Esfahanian, V.; Moghadam, R.K.

    2005-01-01

    An appropriate combination of the thin-layer Navier-Stokes (TLNS) and parabolized Navier-Stokes (PNS) solvers is used to accurately and efficiently compute hypersonic flowfields of equilibrium air around blunt-body configurations. The TLNS equations are solved in the nose region to provide the initial data plane needed for the solution of the PNS equations. Then the PNS equations are employed to efficiently compute the flowfield for the afterbody region by using a space marching procedure. Both the TLNS and the PNS equations are numerically solved by using the implicit non-iterative finite-difference algorithm of Beam and Warming. A shock fitting technique is used in both the TLNS and PNS codes to obtain accurate solution in the vicinity of the shock. To validate the results of the developed TLNS code, hypersonic laminar flow over a sphere at Mach number of 11.26 is computed. To demonstrate the accuracy and efficiency of using the present TLNS-PNS methodology, the computations are performed for hypersonic flow over 5 o long slender blunt cone at Mach number of 19.25. The results of these computations are found to be in good agreement with available numerical and experimental data. The effects of real gas on the flowfield characteristics are also studied in both the TLNS and PNS solutions. (author)

  15. Transition Experiments on Large Bluntness Cones with Distributed Roughness in Hypersonic Flight

    Science.gov (United States)

    Reda, Daniel. C.; Wilder, Michael C.; Prabhu, Dinesh K.

    2012-01-01

    Large bluntness cones with smooth nosetips and roughened frusta were flown in the NASA Ames hypersonic ballistic range at a Mach number of 10 through quiescent air environments. Global surface intensity (temperature) distributions were optically measured and analyzed to determine transition onset and progression over the roughened surface. Real-gas Navier-Stokes calculations of model flowfields, including laminar boundary layer development in these flowfields, were conducted to predict values of key dimensionless parameters used to correlate transition on such configurations in hypersonic flow. For these large bluntness cases, predicted axial distributions of the roughness Reynolds number showed (for each specified freestream pressure) that this parameter was a maximum at the physical beginning of the roughened zone and decreased with increasing run length along the roughened surface. Roughness-induced transition occurred downstream of this maximum roughness Reynolds number location, and progressed upstream towards the beginning of the roughened zone as freestream pressure was systematically increased. Roughness elements encountered at the upstream edge of the roughened frusta thus acted like a finite-extent trip array, consistent with published results concerning the tripping effectiveness of roughness bands placed on otherwise smooth surfaces.

  16. Massive hemothorax due to inferior phrenic artery injury after blunt trauma.

    Science.gov (United States)

    Aoki, Makoto; Shibuya, Kei; Kaneko, Minoru; Koizumi, Ayana; Murata, Masato; Nakajima, Jun; Hagiwara, Shuichi; Kanbe, Masahiko; Koyama, Yoshinori; Tsushima, Yoshito; Oshima, Kiyohiro

    2015-01-01

    Injury to the inferior phrenic artery after blunt trauma is an extremely rare event, and it may occur under unanticipated conditions. This case report describes an injury to the left inferior phrenic artery caused by blunt trauma, which was complicated by massive hemothorax, and treated with transcatheter arterial embolization (TAE). An 81 year-old female hit by a car while walking at the traffic intersection was transferred to the emergency department, computed tomography scanning revealed active extravasations of the contrast medium within the retrocrural space and from branches of the internal iliac artery. The patient underwent repeated angiography, and active extravasation of contrast medium was observed between the retrocrural space and the right pleural space originating from the left inferior phrenic artery. The injured left inferior phrenic artery was successfully embolized with N-butyl cyanoacrylate, resulting in stabilization of the patient's clinical condition. Inferior phrenic artery injury should be recognized as a rare phenomenon and causative factor for hemothorax. TAE represents a safe and effective treatment for this complication and obviates the need for a thoracotomy.

  17. Isolated Multiple Fragmented Cricoid Fracture Associated with External Blunt Neck Trauma: A Case Report

    International Nuclear Information System (INIS)

    Lee, Byung Hoon; Hwang, Yoon Joon; Kim, Yong Hoon; Seo, Jung Wook; Cho, Hyeon Je; Kim, Yeon Soo

    2010-01-01

    Blunt laryngeal trauma is a relatively uncommon but possibly life-threatening injury. An isolated cricoid fracture associated with blunt trauma is rare. We report a case of an isolated multiple fragmented cricoid cartilage fracture that developed in a 20-year-old man after a blunt neck trauma that occurred during a baseball game and was diagnosed by 64-slice multidetector computed tomography (MDCT)

  18. Effects of Forward- and Backward-Facing Steps on the Crossflow Receptivity and Stability in Supersonic Boundary Layers

    Science.gov (United States)

    Balakumar, P.; King, Rudolph A.; Eppink, Jenna L.

    2014-01-01

    The effects of forward- and backward-facing steps on the receptivity and stability of three-dimensional supersonic boundary layers over a swept wing with a blunt leading edge are numerically investigated for a freestream Mach number of 3 and a sweep angle of 30 degrees. The flow fields are obtained by solving the full Navier-Stokes equations. The evolution of instability waves generated by surface roughness is simulated with and without the forward- and backward-facing steps. The separation bubble lengths are about 5-10 step heights for the forward-facing step and are about 10 for the backward-facing step. The linear stability calculations show very strong instability in the separated region with a large frequency domain. The simulation results show that the presence of backward-facing steps decreases the amplitude of the stationary crossflow vortices with longer spanwise wavelengths by about fifty percent and the presence of forward-facing steps does not modify the amplitudes noticeably across the steps. The waves with the shorter wavelengths grow substantially downstream of the step in agreement with the linear stability prediction.

  19. On wall pressure fluctuations and their coupling with vortex dynamics in a separated–reattached turbulent flow over a blunt flat plate

    International Nuclear Information System (INIS)

    Tenaud, C.; Podvin, B.; Fraigneau, Y.; Daru, V.

    2016-01-01

    Highlights: • Study devoted to the compressible LES of the separated/reattached turbulent flow over a blunt flat plate with a right-angled leading edge. • Original contribution using a compressible approach to analyze main coherent structure features and their relation to the unsteady pressure field in the separated/reattached turbulent flow. • The present study provides a well resolved LES reference data-basis that is compared to incompressible results for validation. • It contributes to a better understanding of the coupling between the vortex dynamics and the wall pressure fluctuations, especially in connection with either the vortex shedding or the low frequency shear-layer flapping. - Abstract: This study deals with the numerical predictions through Large-Eddy Simulation (LES) of the separated–reattached turbulent flow over a blunt flat plate for analyzing main coherent structure features and their relation to the unsteady pressure field. A compressible approach that inherently includes acoustic propagation is here followed to describe the relationship between pressure fluctuations and vortex dynamics around the separation bubble. The objective of the present work is then to contribute to a better understanding of the coupling between the vortex dynamics and the wall pressure fluctuations. The filtered compressible Navier–Stokes equations are then solved with a numerical method that follows a Lax–Wendroff approach to recover a high accuracy in both time and space. For validations, the present numerical results are compared to experimental measurements, coming from both the Pprime laboratory (Sicot el al., 2012) and the literature (Cherry et al., 1984; Kiya and Sasaki, 1985; Tafti and Vanka,1991; Sicot et al., 2012). Our numerical results very well predict mean and fluctuating pressure and velocity fields. Flapping, shedding as well as Kelvin–Helmholtz characteristic frequencies educed by present simulations are in very good agreement with the

  20. Comparison of finite element J-integral evaluations for the blunt crack model and the sharp crack model

    International Nuclear Information System (INIS)

    Pan, Y.C.; Kennedy, J.M.

    1983-01-01

    In assessing the safety of a liquid metal fast breeder reactor (LMFBR), a major concern is that of hot sodium coming into contact with either unprotected concrete or steel-lined concrete equipment cells and containment structures. An aspect of this is the potential of concrete cracking which would significantly influence the safety assessment. Concrete cracking in finite element analysis can be modeled as a blunt crack in which the crack is assumed to be uniformly distributed throughout the area of the element. A blunt crack model based on the energy release rate and the effective strength concepts which was insensitive to the element size was presented by Bazant and Cedolin. Some difficulties were encountered in incorporating their approach into a general purpose finite element code. An approach based on the J-integral to circumvent some of the difficulties was proposed by Pan, Marchertas, and Kennedy. Alternatively, cracking can also be modeled as a sharp crack where the crack surface is treated as the boundary of the finite element mesh. The sharp crack model is adopted by most researchers and its J-integral has been well established. It is desirable to establish the correlation between the J-integrals, or the energy release rates, for the blunt crack model and the sharp crack model so that data obtained from one model can be used on the other

  1. Diagnosis and management of colonic injuries following blunt trauma.

    Science.gov (United States)

    Zheng, Yi-Xiong; Chen, Li; Tao, Si-Feng; Song, Ping; Xu, Shao-Ming

    2007-01-28

    To retrospectively evaluate the preoperative diagnostic approaches and management of colonic injuries following blunt abdominal trauma. A total of 82 patients with colonic injuries caused by blunt trauma between January 1992 and December 2005 were enrolled. Data were collected on clinical presentation, investigations, diagnostic methods, associated injuries, and operative management. Colonic injury-related mortality and abdominal complications were analyzed. Colonic injuries were caused mainly by motor vehicle accidents. Of the 82 patients, 58 (70.3%) had other associated injuries. Laparotomy was performed within 6 h after injury in 69 cases (84.1%), laparoscopy in 3 because of haemodynamic instability. The most commonly injured site was located in the transverse colon. The mean colon injury scale score was 2.8. The degree of faecal contamination was classified as mild in 18 (22.0%), moderate in 42 (51.2%), severe in 14 (17.1%), and unknown in 8 (9.8%) cases. Sixty-seven patients (81.7%) were treated with primary repair or resection and anastomosis. Faecal stream diversion was performed in 15 cases (18.3%). The overall mortality rate was 6.1%. The incidence of colonic injury-related abdominal complications was 20.7%. The only independent predictor of complications was the degree of peritoneal faecal contamination (P = 0.02). Colonic injuries following blunt trauma are especially important because of the severity and complexity of associated injuries. A thorough physical examination and a combination of tests can be used to evaluate the indications for laparotomy. One stage management at the time of initial exploration is most often used for colonic injuries.

  2. Blunted Diurnal Cortisol Activity in Healthy Adults with Childhood Adversity.

    Science.gov (United States)

    Kuras, Yuliya I; Assaf, Naomi; Thoma, Myriam V; Gianferante, Danielle; Hanlin, Luke; Chen, Xuejie; Fiksdal, Alexander; Rohleder, Nicolas

    2017-01-01

    Childhood adversity, such as neglect, or physical, emotional, or sexual abuse, is prevalent in the U.S. and worldwide, and connected to an elevated incidence of disease in adulthood. A pathway in this relationship might be altered hypothalamic-pituitary-adrenal (HPA) axis functioning, as a result of differential hippocampal development in early life. A blunted diurnal cortisol slope is a precursor for many disorders. While studies have focused on HPA reactivity in relation to childhood adversity, there has been markedly less research on basal HPA functioning in those with low-to-moderate adversity. Based on previous research, we hypothesized that adults with low-to-moderate childhood adversity would have altered HPA axis functioning, as evidenced by a blunted diurnal cortisol slope and altered cortisol awakening response (CAR). Healthy adults aged 18-65 ( n = 61 adults; 31 males and 30 females) completed the Childhood Trauma Questionnaire. Participants provided at-home saliva samples on two consecutive days at wake-up, and 30 min, 1, 4, 9, and 13 h later; samples were averaged over the 2 days. We found that low-to-moderate childhood adversity predicted lower morning cortisol (β = -0.34, p = 0.007, R 2 = 0.21), as well as a blunted cortisol slope (β = 2.97, p = 0.004, R 2 = 0.22), but found no association with CAR (β = 0.19, p = 0.14, R 2 = 0.12). Overall, we found that in healthy participants, low-to-moderate adversity in childhood is associated with altered basal HPA activity in adulthood. Our findings indicate that even low levels of childhood adversity may predispose individuals to disease associated with HPA dysregulation in later life.

  3. Aetiology, epidemiology and management strategies for blunt scrotal trauma.

    Science.gov (United States)

    Dalton, D M; Davis, N F; O'Neill, D C; Brady, C M; Kiely, E A; O'Brien, M F

    2016-02-01

    To describe our experience of all patients presenting to a tertiary referral centre over a 3 year time period with blunt scrotal trauma and to describe a methodical approach for managing this group of patients. A retrospective analysis was performed on all patients presenting to the Emergency Department (ED) of a level 1 trauma centre with blunt scrotal trauma from 2010 to 2013 inclusive. Inclusion criteria included a recent history of blunt scrotal trauma with associated pain and/or swelling of the affected testis on clinical examination. Twenty-seven male patients with a median age of 19 (range 8-65) years were included and all but 1 patient underwent scrotal ultrasonography upon presentation. Sixteen patients (59%) presented with scrotal trauma secondary to a sports related injury. Fifteen patients were managed conservatively and of the 12 who underwent urgent exploration 9 had a testicular rupture, including 1 who had an emergency orchidectomy due to a completely shattered testis. Four patients had >30% of the testis replaced by necrotic tissue/haematoma; of which 2 ultimately underwent orchidectomy and insertion of testicular prosthesis. Our findings demonstrate that the necessity for scrotal protection in sports that predispose to scrotal trauma should be reviewed. We also demonstrate the importance of scrotal ultrasonography for determining an appropriate management strategy (i.e., conservative versus surgical treatment) in this young patient cohort. Copyright © 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  4. Behind armour blunt trauma--an emerging problem.

    Science.gov (United States)

    Cannon, L

    2001-02-01

    Behind Armour Blunt Trauma (BABT) is the non-penetrating injury resulting from the rapid deformation of armours covering the body. The deformation of the surface of an armour in contact with the body wall arises from the impact of a bullet or other projectile on its front face. The deformation is part of the retardation and energy absorbing process that captures the projectile. In extreme circumstances, the BABT may result in death, even though the projectile has not perforated the armour. An escalation of the available energy of bullets and the desire of armour designers to minimise the weight and bulk of personal armour systems will increase the risk of BABT in military and security forces personnel. In order to develop materials that can be interposed between the armour and the body wall to attenuate the transfer of energy into the body, it is essential that the mechanism of BABT is known. There is a great deal of activity within UK and NATO to unravel the interactions; the mechanism is likely to be a combination of stress (pressure) waves generated by the rapid initial motion of the rear of the armour, and shear deformation to viscera produced by gross deflection of the body wall. Physical and computer model systems are under development to characterise the biophysical processes and provide performance targets for materials to be placed between armours and the body wall in order to attenuate the injuries (trauma attenuating backings-TABs). The patho-physiological consequences of BABT are being clarified by research, but the injuries will have some of the features of blunt chest trauma observed in road traffic accidents and other forms of civilian blunt impact injury. The injuries also have characteristics of primary blast injury. An overview diagnosis and treatment is described.

  5. Blunted Diurnal Cortisol Activity in Healthy Adults with Childhood Adversity

    Directory of Open Access Journals (Sweden)

    Yuliya I. Kuras

    2017-11-01

    Full Text Available Childhood adversity, such as neglect, or physical, emotional, or sexual abuse, is prevalent in the U.S. and worldwide, and connected to an elevated incidence of disease in adulthood. A pathway in this relationship might be altered hypothalamic-pituitary-adrenal (HPA axis functioning, as a result of differential hippocampal development in early life. A blunted diurnal cortisol slope is a precursor for many disorders. While studies have focused on HPA reactivity in relation to childhood adversity, there has been markedly less research on basal HPA functioning in those with low-to-moderate adversity. Based on previous research, we hypothesized that adults with low-to-moderate childhood adversity would have altered HPA axis functioning, as evidenced by a blunted diurnal cortisol slope and altered cortisol awakening response (CAR. Healthy adults aged 18–65 (n = 61 adults; 31 males and 30 females completed the Childhood Trauma Questionnaire. Participants provided at-home saliva samples on two consecutive days at wake-up, and 30 min, 1, 4, 9, and 13 h later; samples were averaged over the 2 days. We found that low-to-moderate childhood adversity predicted lower morning cortisol (β = -0.34, p = 0.007, R2 = 0.21, as well as a blunted cortisol slope (β = 2.97, p = 0.004, R2 = 0.22, but found no association with CAR (β = 0.19, p = 0.14, R2 = 0.12. Overall, we found that in healthy participants, low-to-moderate adversity in childhood is associated with altered basal HPA activity in adulthood. Our findings indicate that even low levels of childhood adversity may predispose individuals to disease associated with HPA dysregulation in later life.

  6. Imaging of blunt chest trauma; Bildgebung des stumpfen Thoraxtraumas

    Energy Technology Data Exchange (ETDEWEB)

    Prosch, H. [Medizinische Universitaet Wien, Allgemeines Krankenhaus, Univ.-Klinik fuer Radiologie und Nuklearmedizin, Wien (Austria); Negrin, L. [Medizinische Universitaet Wien, Allgemeines Krankenhaus, Univ.-Klinik fuer Unfallchirurgie, Wien (Austria)

    2014-09-15

    Blunt chest trauma is associated with high morbidity and mortality. Consequently, all patients should be evaluated radiologically after blunt chest trauma to allow timely and appropriate treatment. Conventional chest radiographs and computed tomography (CT) are proven modalities with which to evaluate patients after blunt chest trauma. Over the last several years extended focused assessment with sonography for trauma (eFAST) has gained increasing importance for the initial assessment of seriously injured patients. In the acute phase of severely injured patients eFAST examinations are helpful to exclude pneumothorax, hemothorax and hemopericardium. Chest radiographs may also be used to diagnose a pneumothorax or hemothorax; however, the sensitivity is limited and CT is the diagnostic modality of choice to evaluate severely injured patients. (orig.) [German] Stumpfe Thoraxtraumen gehen mit einer hohen Morbiditaet und Mortalitaet einher. Daher sollten Patienten mit Verdacht auf ein stumpfes Thoraxtrauma rasch radiologisch untersucht werden, damit die entsprechenden therapeutischen Schritte zeitgerecht eingeleitet werden koennen. Zur Abklaerung von Patienten nach einem stumpfen Thoraxtrauma sind seit Jahren das konventionelle Lungenroentgen und die Computertomographie bewaehrte Verfahren. In den letzten Jahren hat die fokussierte Ultraschalluntersuchung (eFAST, Extended Focused Assessment with Sonography for Trauma) von schwerverletzten Patienten vermehrt an Bedeutung gewonnen. Durch eine eFAST-Untersuchung kann in der Akutphase rasch geklaert werden, ob bei dem Patienten ein therapiebeduerftiger Pneumothorax, Haematoperikard oder Haematothorax vorliegen. Auch das Lungenroentgen wird zur Diagnose eines Pneumothorax oder Haematothorax eingesetzt, wenngleich seine Sensitivitaet deutlich eingeschraenkt ist. Die CT ist das diagnostische Verfahren der Wahl, um v. a. Patienten mit einem schweren Thoraxtrauma abzuklaeren. (orig.)

  7. Pediatric blunt cerebrovascular injury: the McGovern screening score.

    Science.gov (United States)

    Herbert, Joseph P; Venkataraman, Sidish S; Turkmani, Ali H; Zhu, Liang; Kerr, Marcia L; Patel, Rajan P; Ugalde, Irma T; Fletcher, Stephen A; Sandberg, David I; Cox, Charles S; Kitagawa, Ryan S; Day, Arthur L; Shah, Manish N

    2018-03-16

    OBJECTIVE The objective of this study was to assess the incidence, diagnosis, and treatment of pediatric blunt cerebrovascular injury (BCVI) at a busy Level 1 trauma center and to develop a tool for accurately predicting pediatric BCVI and the need for diagnostic testing. METHODS This is a retrospective cohort study of a prospectively collected database of pediatric patients who had sustained blunt trauma (patient age range 0-15 years) and were treated at a Level 1 trauma center between 2005 and 2015. Digital subtraction angiography, MR angiography, or CT angiography was used to confirm BCVI. Recently, the Utah score has emerged as a screening tool specifically targeted toward evaluating BCVI risk in the pediatric population. Using logistical regression and adding mechanism of injury as a logit, the McGovern score was able to use the Utah score as a starting point to create a more sensitive screening tool to identify which pediatric trauma patients should receive angiographic imaging due to a high risk for BCVI. RESULTS A total of 12,614 patients (mean age 6.6 years) were admitted with blunt trauma and prospectively registered in the trauma database. Of these, 460 (3.6%) patients underwent angiography after blunt trauma: 295 (64.1%), 107 (23.3%), 6 (1.3%), and 52 (11.3%) patients underwent CT angiography, MR angiography, digital subtraction angiography, and a combination of imaging modalities, respectively. The BCVI incidence (n = 21; 0.17%) was lower than that in a comparable adult group (p tools for BCVI, misclassified 6 (28.6%), 6 (28.6%), 7 (33.3%), and 10 (47.6%) patients with BCVI, respectively, as "low risk" and not in need of subsequent angiographic imaging. By incorporating the mechanism of injury into the score, the McGovern score only misclassified 4 (19.0%) children, all of whom were managed conservatively with no treatment or aspirin. CONCLUSIONS With a low incidence of pediatric BCVI and a nonsurgical treatment paradigm, a more conservative approach

  8. Blunt dissection in augmentation mammaplasty-an instrumental aid.

    Science.gov (United States)

    Webster, R C; Pedroza, L V; Smith, R C; Smith, K F

    1981-11-01

    The iconoclast is an instrument that facilitates blunt dissection in areas where this basic technique is difficult because of anatomical or postsurgical adherence. Medical and inferior undermining in augmentation mammaplasty in primary and revisional cases is described. The instrument capitalizes on the gripping rather than the spreading strength of the surgeon's hand, allows easy penetration of tissues to be spread apart, and diminished severance of blood vessels. We have used the iconoclast for almost two years in selected cases and have had no problems or complications attributable to it.

  9. CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Wall, S.D. (Univ. of California, San Francisco); Federle, M.P.; Jeffrey, R.B.; Brett, C.M.

    1983-11-01

    Review of abdominal CT scans for evaluation of blunt abdominal trauma yielded 35 cases of pneumothorax, 10 of which had not been diagnosed before CT by clinical examination of plain radiographs. Of the 10 cases initially diagnosed on CT, seven required tube thoracostomy for treatment of the pneumothorax. CT detection of pneumothorax is especially important if mechanical assisted ventilation or general anesthesia is used. Demonstration of pneumothorax requires viewing CT scans of the upper abdomen (lower thorax) at lung windows in addition to the usual soft-tissue windows.

  10. CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma

    International Nuclear Information System (INIS)

    Wall, S.D.; Federle, M.P.; Jeffrey, R.B.; Brett, C.M.

    1983-01-01

    Review of abdominal CT scans for evaluation of blunt abdominal trauma yielded 35 cases of pneumothorax, 10 of which had not been diagnosed before CT by clinical examination of plain radiographs. Of the 10 cases initially diagnosed on CT, seven required tube thoracostomy for treatment of the pneumothorax. CT detection of pneumothorax is especially important if mechanical assisted ventilation or general anesthesia is used. Demonstration of pneumothorax requires viewing CT scans of the upper abdomen (lower thorax) at lung windows in addition to the usual soft-tissue windows

  11. Occult pneumomediastinum in blunt chest trauma: clinical significance.

    Science.gov (United States)

    Rezende-Neto, J B; Hoffmann, J; Al Mahroos, M; Tien, H; Hsee, L C; Spencer Netto, F; Speers, V; Rizoli, S B

    2010-01-01

    Thoracic injuries are potentially responsible for 25% of all trauma deaths. Chest X-ray is commonly used to screen patients with chest injury. However, the use of computed tomography (CT) scan for primary screening is increasing, particularly for blunt trauma. CT scans are more sensitive than chest X-ray in detecting intra-thoracic abnormalities such as pneumothoraces and pneumomediastinums. Pneumomediastinum detected by chest X-ray or "overt pneumomediastinum", raises the concern of possible aerodigestive tract injuries. In contrast, there is scarce information on the clinical significance of pneumomediastinum diagnosed by CT scan only or "occult pneumomediastinum". Therefore we investigated the clinical consequences of occult pneumomediastinum in our blunt trauma population. A 2-year retrospective chart review of all blunt chest trauma patients with initial chest CT scan admitted to a level I trauma centre. Data extracted from the medical records include; demographics, occult, overt, or no pneumomediastinum, the presence of intra-thoracic aerodigestive tract injuries (trachea, bronchus, and/or esophagus), mechanism and severity of injury, endotracheal intubation, chest thoracostomy, operations and radiological reports by an attending radiologist. All patients with intra-thoracic aerodigestive tract injuries from 1994 to 2004 were also investigated. Of 897 patients who met the inclusion criteria 839 (93.5%) had no pneumomediastinum. Five patients (0.6%) had overt pneumomediastinum and 53 patients (5.9%) had occult pneumomediastinum. Patients with occult pneumomediastinum had significantly higher ISS and AIS chest (pchest thoracostomy tube was more common (ppneumothorax. None of the patients with occult pneumomediastinum had aerodigestive tract injuries (95%CI 0-0.06). Follow up CT scan of patients with occult pneumomediastinum showed complete resolution in all cases, in average 3 h after the initial exam. Occult pneumomediastinum occurred in approximately 6% of

  12. Improvement of airfoil trailing edge bluntness noise model

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2016-01-01

    In this article, airfoil trailing edge bluntness noise is investigated using both computational aero-acoustic and semi-empirical approach. For engineering purposes, one of the most commonly used prediction tools for trailing edge noise are based on semi-empirical approaches, for example, the Brooks......, Pope, and Marcolini airfoil noise prediction model developed by Brooks, Pope, and Marcolini (NASA Reference Publication 1218, 1989). It was found in previous study that the Brooks, Pope, and Marcolini model tends to over-predict noise at high frequencies. Furthermore, it was observed...

  13. Feedback Blunting: Total Sleep Deprivation Impairs Decision Making that Requires Updating Based on Feedback

    Science.gov (United States)

    Whitney, Paul; Hinson, John M.; Jackson, Melinda L.; Van Dongen, Hans P.A.

    2015-01-01

    Study Objectives: To better understand the sometimes catastrophic effects of sleep loss on naturalistic decision making, we investigated effects of sleep deprivation on decision making in a reversal learning paradigm requiring acquisition and updating of information based on outcome feedback. Design: Subjects were randomized to a sleep deprivation or control condition, with performance testing at baseline, after 2 nights of total sleep deprivation (or rested control), and following 2 nights of recovery sleep. Subjects performed a decision task involving initial learning of go and no go response sets followed by unannounced reversal of contingencies, requiring use of outcome feedback for decisions. A working memory scanning task and psychomotor vigilance test were also administered. Setting: Six consecutive days and nights in a controlled laboratory environment with continuous behavioral monitoring. Subjects: Twenty-six subjects (22–40 y of age; 10 women). Interventions: Thirteen subjects were randomized to a 62-h total sleep deprivation condition; the others were controls. Results: Unlike controls, sleep deprived subjects had difficulty with initial learning of go and no go stimuli sets and had profound impairment adapting to reversal. Skin conductance responses to outcome feedback were diminished, indicating blunted affective reactions to feedback accompanying sleep deprivation. Working memory scanning performance was not significantly affected by sleep deprivation. And although sleep deprived subjects showed expected attentional lapses, these could not account for impairments in reversal learning decision making. Conclusions: Sleep deprivation is particularly problematic for decision making involving uncertainty and unexpected change. Blunted reactions to feedback while sleep deprived underlie failures to adapt to uncertainty and changing contingencies. Thus, an error may register, but with diminished effect because of reduced affective valence of the feedback

  14. Three-dimensional wake dynamics of a blunt and divergent trailing edge airfoil

    Energy Technology Data Exchange (ETDEWEB)

    El-Gammal, M. [Rowan Williams Davies and Irwin Inc. (RWDI), Guelph, ON (Canada); Hangan, H. [University of Western Ontario, Boundary Layer Wind Tunnel Laboratory, London, ON (Canada)

    2008-05-15

    The wake dynamics of an airfoil with a blunt and divergent trailing edge is investigated experimentally at relatively high Reynolds. The near wake topology is examined versus different levels of free stream turbulence FST and angles of attack, while the downstream wake evolution is characterized at various levels of FST. The FST is found to have a significant effect on the shapes of turbulence profiles and on the downstream location where the flow reaches its quasi-asymptotic behavior. Streamwise vortices (ribs) corresponding to spanwise variations of turbulence quantities are identified in the near wake region. Simultaneous multi-point hot-wire measurements indicate that their spatial arrangement is similar to Williamson's (Ann Rev Fluid Mech 29:477-539, 1996) mode B laminar wake flow topology. The results suggest that the statistical spanwise distribution of ribs is independent of FST effects and angle of attack as long as the vortex shedding Strouhal number remains approximately similar. (orig.)

  15. Blunt Traumatic Extracranial Cerebrovascular Injury and Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Paul M. Foreman

    2017-04-01

    Full Text Available Background: Ischemic stroke occurs in a significant subset of patients with blunt traumatic cerebrovascular injury (TCVI. The patients are victims of motor vehicle crashes, assaults or other high-energy collisions, and suffer ischemic stroke due to injury to the extracranial carotid or vertebral arteries. Summary: An increasing number of patients with TCVI are being identified, largely because of the expanding use of computed tomography angiography for screening patients with blunt trauma. Patients with TCVI are particularly challenging to manage because they often suffer polytrauma, that is, numerous additional injuries including orthopedic, chest, abdominal, and head injuries. Presently, there is no consensus about optimal management. Key Messages: Most literature about TCVI and stroke has been published in trauma, general surgery, and neurosurgery journals; because of this, and because these patients are managed primarily by trauma surgeons, patients with stroke due to TCVI have been essentially hidden from view of neurologists. This review is intended to bring this clinical entity to the attention of clinicians and investigators with specific expertise in neurology and stroke.

  16. Rib fractures in blunt chest trauma - associated thoracic injuries

    Directory of Open Access Journals (Sweden)

    Iv. Dimitrov

    2017-09-01

    Full Text Available PURPOSE. The aim of our retrospective study was to analyze the patterns of associated thoracic injuries in patients underwent blunt chest trauma and rib fractures. METHODS. The study included 212 patients with rib fractures due to blunt thoracic trauma. The mechanism of trauma, the type of rib fracture and the type of associated injuries were analyzed. RESULTS. The patients were divided in two groups according to the number of fractured ribs-group I included the patients with up to two fractured ribs (72 patients-33,9%, and group II – with ≥3 fractured ribs (140 patients-66,1%. Associated chest injuries were present in 36 of the patients from group I (50%, and in 133 patients from group II (95%. Pulmonary contusion was the most common intrathoracicinjurie-65,6% of the cases. The mean hospital stay was 8, 7 days. The lethality rate was 16,9% -all of them due to the associated chest injuries. CONCLUSIONS. The mortality related to rib fractures is affected by the associated thoracic injuries, the advanced age, and the number of fractured ribs.

  17. Non-equilibrium blunt body flows in ionized gases

    International Nuclear Information System (INIS)

    Nishida, Michio

    1981-01-01

    The behaviors of electrons and electronically excited atoms in non-equilibrium and partially ionized blunt-body-flows are described. Formulation has been made separately in a shock layer and in a free stream, and then the free stream solution has been connected with the shock layer solution by matching the two solutions at the shock layer edge. The method of this matching is described here. The partially ionized gas is considered to be composed of neutral atoms, ions and electrons. Furthermore, the neutral atoms are divided into atoms in excited levels. Therefore, it is considered that electron energy released due to excitation, and that gained due to de-excitation, contribute to electron energy. Thus, the electron energy equation including these contributions is solved, coupled with the continuity equations of the excited atoms and the electrons. An electron temperature distribution from a free stream to a blunt body wall has been investigated for a case when the electrons are in thermal non-equilibrium with heavy particles in the free stream. In addition, the distributions of the excited atom density are discussed in the present analysis. (author)

  18. CT analysis of pulmonary injuries from blunt chest trauma

    International Nuclear Information System (INIS)

    Konno, Shoko

    1996-01-01

    The purpose of this paper is to analyze the CT findings of pulmonary parenchymal injuries due to blunt chest trauma and to categorize CT findings on the basis of their outcome. The materials of this study consist of 62 patients who had pulmonary injuries on CT obtained within 6 hours after blunt chest trauma. CT findings were analysed with regards to the shape, size, and distribution of the lesions. Follow-up CT scans were obtained in 35 patients at intervals from 1 day to 1 month after the initial CT study. CT showed ill-defined opacities in 59 patients (64 lesions in the peripheral area and 95 in the non-peripheral area) and pulmonary nodules with or without cavitary lesions in 30 patients (7 lesions in the peripheral area and 31 in the non-peripheral area). Follow-up CT allowed the classification of these pulmonary injuries into 3 types; the non-peripheral, ill-defined opacities showing immediate clearing, nodules with or without cavitary lesions over 1 cm in diameter showing prolongation, and the peripheral ill-defined opacities adjacent to the thoracic cage, and small nodules with or without cavitary lesions within 1 cm in diameter, showing various courses. CT has marked advantage over plain chest radiographs not only in the detection rate but in accurate estimation of the prognosis of the lesions. (author)

  19. Value of Multidetector Computed Tomography in Assessing Blunt Multitrauma Patients

    Energy Technology Data Exchange (ETDEWEB)

    Ahvenjaervi, L.; Mattila, L.; Ojala, R.; Tervonen, O. [Oulu Univ. Hospital (Finland). Dept. of Diagnostic Radiology

    2005-04-01

    Purpose: To find out if multidetector computed tomography (MDCT), using a dedicated trauma protocol, provides sufficient diagnostic information of the injuries of blunt multitrauma patients to enable the planning of treatment for all body compartments. Material and Methods: One-hundred-and-thirty-three patients exposed to high-energy trauma were referred and scanned with the standardized MDCT multitrauma protocol. The imaging protocol consisted of axial scanning of the head and helical scanning of the facial bones, cervical spine, thorax, abdomen, and pelvis. The scanning times were 12 s for the head, 19-21 s for the facial bones and cervical spine (1 mm collimation), and 32-50 s for the thorax, abdomen, and pelvis (2 mm collimation). One-hundred-and-forty milliliters of non-iodinated contrast material (300 mg I/ml) was administered intravenously at 3 ml/s. Results: Ninety-nine of the patients (74%) had at least one finding consistent with trauma. The most frequent findings were in the thorax in 58 patients (44%). Nineteen false-negative findings and two false-positive findings were made. The overall sensitivity of MDCT was 94%, specificity 100%, and accuracy 97%. Conclusion: MDCT is accurate in the assessment of blunt multitrauma patients. The decision to treat the patient can be made on the basis of MDCT with a reasonable level of certainty.

  20. Total transverse rupture of the duodenum after blunt abdominal trauma.

    Science.gov (United States)

    Pirozzi, Cesare; Di Marco, Carluccio; Loponte, Margherita; Savino, Grazia

    2014-05-11

    Complete transverse rupture of the duodenum as an isolated lesion in blunt trauma can be considered as exceptional. The aim of this report is to discuss diagnostic procedures and surgical options in such an infrequent presentation. We report on a 37 year old man who had a total transverse rupture of the duodenum after blunt abdominal trauma. Diagnosis was suspected after contrast enhanced CT scan and confirmed at laparotomy; duodenal rupture was repaired by an end to end duodenal-duodenal anastomosis, after Kocher maneuver. The patient had fast and complete recovery. A high index of suspicion is necessary for timely diagnosis. Multi detector contrast enhanced CT scan is the gold standard for that aim. Surgical management must be tailored on an individual basis, since many techniques are available for both reconstruction and duodenum decompression. Kocher maneuver is essential for complete inspection of the pancreatic duodenal block and for appropriate reconstruction. Management of isolated duodenal rupture can be difficult. Contrast enhanced TC scans is essential for timely diagnosis. Primary repair can be achieved by an end to end duodenum anastomosis after Kocher maneuver, although alternative techniques are available for tailored solutions. Complex duodenum decompression techniques are not mandatory.

  1. Blunt hepatic trauma: comparison between surgical and nonoperative treatment.

    Science.gov (United States)

    Zago, Thiago Messias; Pereira, Bruno Monteiro; Calderan, Thiago Rodrigues Araujo; Hirano, Elcio Shiyoiti; Rizoli, Sandro; Fraga, Gustavo Pereira

    2012-01-01

    To examine the outcomes of blunt hepatic trauma, and compare surgical and non-surgical treatment in patients admitted with hemodynamic stability and with no obvious indications of laparotomy. This is a retrospective study of cases admitted to a university teaching hospital between the years 2000 and 2010. Patients undergoing surgical treatment were divided into two groups: (a) all patients undergoing surgical treatment, and (b) patients with obvious need for surgery. In this period, 120 patients were admitted with blunt hepatic trauma. Sixty five patients (54.1%) were treated non-operatively and fifty five patients were operated upon. Patients treated non-operatively had better physiologic conditions on admission, demonstrated less severe injuries (except the grade of hepatic injury), received less blood components and had lower morbidity and mortality than the patients operated upon. Patients who underwent non-operative treatment had a lower need for blood transfusion but higher rates of complications and mortality than the patients operated upon. Patients who were operated upon, with no obvious indications for surgery, had higher rates of complication and mortality than patients not operated upon. A non-operative approach resulted in lower complications, a lower need for blood transfusions and lower mortality.

  2. Pneumoscrotum as Complication of Blunt Thoracic Trauma: A Case Report

    Directory of Open Access Journals (Sweden)

    Eftychios Lostoridis

    2013-01-01

    Full Text Available Introduction. Pneumoscrotum is a rare clinical entity. It presents with swollen scrotal sac and sometimes with palpable crepitus. It has many etiologies. One of them is due to blunt trauma of the thoracic cage, causing pneumothorax and/or pneumomediastinum. Case Presentation. We report the case of an 82-year-old male who was transferred to the Emergency Department with signs of respiratory distress after a blunt chest trauma. A CT scan was obtained, and bilateral pneumothoraces with four broken ribs were disclosed. Subcutaneous emphysema expanding from the eyelids to the scrotum was observed, and a chest tube was inserted on the right side with immediate improvement of the vital signs of the patient. Discussion. Pneumoscrotum has three major etiologies: (a local introduction of air or infection from gas-producing bacteria, (b pneumoperitoneum, and (c air accumulation from lungs, mediastinum, or retroperitoneum. These sources account for most of the cases described in the literature. Treatment should be individualized, and surgical consultation should be obtained in all cases. Conclusion. Although pneumoscrotum itself is a benign entity, the process by which air accumulates in the scrotum must be clarified, and treatment must target the primary cause.

  3. Nonoperative management for major blunt hepatic trauma. A case report.

    Science.gov (United States)

    Mingoli, Andrea; Saracino, Andrea; Brachini, Gioia; Mariotta, Giovanni; Migliori, Emanuele; Silvestri, Vania

    2015-03-16

    Over the past 20 years the management of blunt liver trauma has evolved from a primary operative approach to a nonoperative one, for both low and high grade injuries, only on the basis of hemodynamic stability. However, in spite of a high success rate of non operative management, it is frequently observed, also in our country, an old fashioned way to approach these patients, based on habit more than observation and evidence based medicine. We present a case of successful nonoperative treatment of a grade IV blunt liver trauma (lacero-contusive injury of V, VI and VII segments) in a 34-year-old woman. Nowadays more than 85% of liver injuries are managed without operative intervention, irrespective of the injury grade. Success rate of the conservative approach ranges from 82% to 100% and almost all complications (14% in high grade injuries) can be managed with interventional radiology procedures, still avoiding major surgery. Today, in the absence of other abdominal injuries requiring surgical exploration, hemodynamic instability from ongoing hemorrhage after primary evaluation and resuscitative treatment, is the only indication to an operative management of traumatic liver injuries.

  4. The role of computed tomography in blunt hepatic injury

    International Nuclear Information System (INIS)

    Kaji, Tatsumi

    1988-01-01

    Computed tomography (CT) images and medical records of 283 patients with blunt abdominal trauma were reviewed. There were 67 patients with hepatic injury. Liver was the most frequently injured organ in blunt abdominal trauma. Most hepatic injuries occurred in the right lobe of the liver. Of the 67 patients with hepatic injury, 60 patients had associated other injuries. There was a high incidence of associated lung injuries (35.8 %). Of importance is the high incidence of associated head injuries (22.4 %), because, in some patients such as those with concomitant head trauma, abdominal symptom is not obvious. The associated hemoperitoneum were correlated with the mode of therapy used in each case (operative vs. nonoperative). 32 patients with hepatic injury but no hemoperitoneum were managed nonoperatively. 9 patients with hepatic injury and little hemoperitoneum were also managed conservatively. 22 patients with high density hemoperitoneum were surgically treated. By combining information on the clinical state of the patient and CT finding, therapy of hepatic injury can be individualized and the incidence of nontherapeutic laparotomies decreased. (author)

  5. Thyroid gland rupture caused by blunt trauma to the neck.

    Science.gov (United States)

    Hara, Hirotaka; Hirose, Yoshinobu; Yamashita, Hiroshi

    2016-02-19

    Thyroid rupture following blunt trauma is extremely rare, and neck pain without swelling may be the only presenting symptom. However, hemorrhage and hematoma subsequently causes severe tracheal compression and respiratory distress. A 71-year-old Japanese woman visited our emergency room with a complaint of increasing right-sided neck pain at the thyroid cartilage level after she tripped and accidentally hit her neck against a pole 3 h back. On admission, her vital signs were stable. There was no swelling or subcutaneous emphysema. Laryngeal endoscopy revealed mild laryngeal edema, although there was no impairment in vocal fold mobility on either side. Contrast-enhanced computed tomography (CT) revealed rupture of the right lobe of the thyroid gland accompanied by a large hematoma extending from the neck to the mediastinum. Under general anesthesia, the right lobe was resected and the hematoma was evacuated. Only a few isolated cases of thyroid rupture caused by blunt neck trauma have been reported in patients with normal thyroid glands and neck pain without swelling may be the only presenting symptom. When suspected, CT should be performed to confirm the diagnosis determine the optimal treatment.

  6. Hepatic Enzyme Decline after Pediatric Blunt Trauma: A Tool for Timing Child Abuse?

    Science.gov (United States)

    Baxter, Amy L.; Lindberg, Daniel M.; Burke, Bonnie L.; Shults, Justine; Holmes, James F.

    2008-01-01

    Objectives: Previous research in adult patients with blunt hepatic injuries has suggested a pattern of serum hepatic transaminase concentration decline. Evaluating this decline after pediatric blunt hepatic trauma could establish parameters for estimating the time of inflicted injuries. Deviation from a consistent transaminase resolution pattern…

  7. Blunt injury of the infrarenal inferior vena cava — imaging and ...

    African Journals Online (AJOL)

    Blunt injury of the infrarenal inferior vena cava — imaging and conservative management. Ian C Duncan, Basil J Sher, Leslie M Fingleson. Abstract. Isolated rupture of the infrarenal segment of the inferior vena cava due to blunt trauma is relatively rare. It may be missed clinically and even diagnostic peritoneal lavage may ...

  8. Blunted lipolytic response to fasting in abdominally obese women: evidence for involvement of hyposomatotropism

    NARCIS (Netherlands)

    Buijs, Madelon M.; Burggraaf, Jacobus; Wijbrandts, Carla; de Kam, Marieke L.; Frölich, Marijke; Cohen, Adam F.; Romijn, Johannes A.; Sauerwein, Hans P.; Meinders, A. Edo; Pijl, Hanno

    2003-01-01

    Background: Abdominal obesity is associated with a blunted lipolytic response to fasting that may contribute to the preservation of adipose tissue mass. Objective: To further explore the pathophysiology of blunted lipolysis during fasting in obesity, we simultaneously measured lipolysis and distinct

  9. Blunt bilateral diaphragmatic rupture—A right side can be easily missed

    Directory of Open Access Journals (Sweden)

    Maria Michailidou

    2015-12-01

    Full Text Available Blunt diaphragmatic rupture (BDR is uncommon with a reported incidence range of 1%–2%. The true incidence is not known. Bilateral BDR is particularly rare. We presented a case of bilateral BDR and we think that the incidence is under-recognised thanks to an easily missed and difficult to diagnose right sided injury. Keywords: Blunt, Diaphragm, Bilateral, Injury

  10. Predictors of abnormal chest CT after blunt trauma: a critical appraisal of the literature.

    NARCIS (Netherlands)

    Brink, M.; Kool, D.R.; Dekker, H.M.; Deunk, J.; Jager, G.J.; Kuijk, C. van; Edwards, M.J.R.; Blickman, J.G.

    2009-01-01

    AIM: To identify and to evaluate predictors that determine whether chest computed tomography (CT) is likely to reveal relevant injuries in adult blunt trauma patients. METHODS: After a comprehensive literature search for original studies on blunt chest injury diagnosis, two independent observers

  11. Computed tomography of the chest in blunt thoracic trauma: results of a prospective study

    International Nuclear Information System (INIS)

    Blostein, P.; Hodgman, C.

    1998-01-01

    Blunt thoracic injuries detected by computed tomography of the chest infrequently require immediate therapy. If immediate therapy is needed, findings will be visible on plain roentgenograms or on clinical exam. Routine Computed Tomography of the chest in blunt trauma is not recommended but may be helpful in selected cases. (N.C.)

  12. Transection of the inferior vena cava from blunt thoracic trauma: case reports.

    Science.gov (United States)

    Peitzman, A B; Udekwu, A O; Pevec, W; Albrink, M

    1989-04-01

    Blunt thoracic trauma is a frequent cause of death in multiple trauma victims. Myocardial rupture may occur in up to 65% of patients who die with thoracic injuries. Two cases are presented with intrapericardial transection of the inferior vena cava, pericardial rupture, and myocardial rupture from blunt thoracic trauma. Both patients died.

  13. Non operative management of blunt splenic trauma: a prospective evaluation of a standardized treatment protocol.

    Science.gov (United States)

    Brillantino, A; Iacobellis, F; Robustelli, U; Villamaina, E; Maglione, F; Colletti, O; De Palma, M; Paladino, F; Noschese, G

    2016-10-01

    The advantages of the conservative approach for major spleen injuries are still debated. This study was designed to evaluate the safety and effectiveness of NOM in the treatment of minor (grade I-II according with the American Association for the Surgery of Trauma; AAST) and severe (AAST grade III-V) blunt splenic trauma, following a standardized treatment protocol. All the hemodynamically stable patients with computer tomography (CT) diagnosis of blunt splenic trauma underwent NOM, which included strict clinical and laboratory observation, 48-72 h contrast-enhanced ultrasonography (CEUS) follow-up and splenic angioembolization, performed both in patients with admission CT evidence of vascular injuries and in patients with falling hematocrit during observation. 87 patients [32 (36.7 %) women and 55 (63.2 %) men, median age 34 (range 14-68)] were included. Of these, 28 patients (32.1 %) had grade I, 22 patients (25.2 %) grade II, 20 patients (22.9 %) grade III, 11 patients (12.6 %) grade IV and 6 patients (6.8 %) grade V injuries. The overall success rate of NOM was 95.4 % (82/87). There was no significant difference in the success rate between the patients with different splenic injuries grade. Of 24 patients that had undergone angioembolization, 22 (91.6 %) showed high splenic injury grade. The success rate of embolization was 91.6 % (22/24). No major complications were observed. The minor complications (2 pleural effusions, 1 pancreatic fistula and 2 splenic abscesses) were successfully treated by EAUS or CT guided drainage. The non operative management of blunt splenic trauma, according to our protocol, represents a safe and effective treatment for both minor and severe injuries, achieving an overall success rate of 95 %. The angiographic study could be indicated both in patients with CT evidence of vascular injuries and in patients with high-grade splenic injuries, regardless of CT findings.

  14. Intracranial pressure monitoring in severe blunt head trauma: does the type of monitoring device matter?

    Science.gov (United States)

    Aiolfi, Alberto; Khor, Desmond; Cho, Jayun; Benjamin, Elizabeth; Inaba, Kenji; Demetriades, Demetrios

    2018-03-01

    OBJECTIVE Intracranial pressure (ICP) monitoring has become the standard of care in the management of severe head trauma. Intraventricular devices (IVDs) and intraparenchymal devices (IPDs) are the 2 most commonly used techniques for ICP monitoring. Despite the widespread use of these devices, very few studies have investigated the effect of device type on outcomes. The purpose of the present study was to compare outcomes between 2 types of ICP monitoring devices in patients with isolated severe blunt head trauma. METHODS This retrospective observational study was based on the American College of Surgeons Trauma Quality Improvement Program database, which was searched for all patients with isolated severe blunt head injury who had an ICP monitor placed in the 2-year period from 2013 to 2014. Extracted variables included demographics, comorbidities, mechanisms of injury, head injury specifics (epidural, subdural, subarachnoid, intracranial hemorrhage, and diffuse axonal injury), Abbreviated Injury Scale (AIS) score for each body area, Injury Severity Score (ISS), vital signs in the emergency department, and craniectomy. Outcomes included 30-day mortality, complications, number of ventilation days, intensive care unit and hospital lengths of stay, and functional independence. RESULTS During the study period, 105,721 patients had isolated severe traumatic brain injury (head AIS score ≥ 3). Overall, an ICP monitoring device was placed in 2562 patients (2.4%): 1358 (53%) had an IVD and 1204 (47%) had an IPD. The severity of the head AIS score did not affect the type of ICP monitoring selected. There was no difference in the median ISS; ISS > 15; head AIS Score 3, 4, or 5; or the need for craniectomy between the 2 device groups. Unadjusted 30-day mortality was significantly higher in the group with IVDs (29% vs 25.5%, p = 0.046); however, stepwise logistic regression analysis showed that the type of ICP monitoring was not an independent risk factor for death

  15. Prior blunt chest trauma may be a cause of single vessel coronary disease; hypothesis and review

    DEFF Research Database (Denmark)

    Bartels, Mette Damkjær; Nielsen, PE; Sleight, P

    2006-01-01

    Prompted by a case where a patient (with no risk factors, and single vessel disease) developed angina pectoris after previous blunt chest trauma, we searched Medline for blunt chest trauma and myocardial ischaemia. We found 77 cases describing AMI after blunt chest trauma, but only one reporting...... angina pectoris. We focused on the age and sex distribution, type of trauma, the angiography findings and the time interval between the trauma and the angiography. The age distribution was atypical, compared to AMI in general; 82% of the patients with AMI after blunt chest trauma were less than 45 years......, which strongly suggested a causal relation between the trauma and subsequent occlusion. AMI should therefore be considered in patients suffering from chest pain after blunt chest trauma. Because traumatic AMI might often be the result of an intimal tear or dissection, thrombolytic therapy might worsen...

  16. Feedback Blunting: Total Sleep Deprivation Impairs Decision Making that Requires Updating Based on Feedback.

    Science.gov (United States)

    Whitney, Paul; Hinson, John M; Jackson, Melinda L; Van Dongen, Hans P A

    2015-05-01

    To better understand the sometimes catastrophic effects of sleep loss on naturalistic decision making, we investigated effects of sleep deprivation on decision making in a reversal learning paradigm requiring acquisition and updating of information based on outcome feedback. Subjects were randomized to a sleep deprivation or control condition, with performance testing at baseline, after 2 nights of total sleep deprivation (or rested control), and following 2 nights of recovery sleep. Subjects performed a decision task involving initial learning of go and no go response sets followed by unannounced reversal of contingencies, requiring use of outcome feedback for decisions. A working memory scanning task and psychomotor vigilance test were also administered. Six consecutive days and nights in a controlled laboratory environment with continuous behavioral monitoring. Twenty-six subjects (22-40 y of age; 10 women). Thirteen subjects were randomized to a 62-h total sleep deprivation condition; the others were controls. Unlike controls, sleep deprived subjects had difficulty with initial learning of go and no go stimuli sets and had profound impairment adapting to reversal. Skin conductance responses to outcome feedback were diminished, indicating blunted affective reactions to feedback accompanying sleep deprivation. Working memory scanning performance was not significantly affected by sleep deprivation. And although sleep deprived subjects showed expected attentional lapses, these could not account for impairments in reversal learning decision making. Sleep deprivation is particularly problematic for decision making involving uncertainty and unexpected change. Blunted reactions to feedback while sleep deprived underlie failures to adapt to uncertainty and changing contingencies. Thus, an error may register, but with diminished effect because of reduced affective valence of the feedback or because the feedback is not cognitively bound with the choice. This has important

  17. Blunt Cardiac Injury in the Severely Injured - A Retrospective Multicentre Study.

    Directory of Open Access Journals (Sweden)

    Marc Hanschen

    Full Text Available Blunt cardiac injury is a rare trauma entity. Here, we sought to evaluate the relevance and prognostic significance of blunt cardiac injury in severely injured patients.In a retrospective multicentre study, using data collected from 47,580 patients enrolled to TraumaRegister DGU (1993-2009, characteristics of trauma, prehospital / hospital trauma management, and outcome analysis were correlated to the severity of blunt cardiac injury. The severity of cardiac injury was assessed according to the abbreviated injury score (AIS score 1-6, the revised injury severity score (RISC allowed comparison of expected outcome with injury severity-dependent outcome. N = 1.090 had blunt cardiac trauma (AIS 1-6 (2.3% of patients.Predictors of blunt cardiac injury could be identified. Sternal fractures indicate a high risk of the presence of blunt cardiac injury (AIS 0 [control]: 3.0%; AIS 1: 19.3%; AIS 2-6: 19.1%. The overall mortality rate was 13.9%, minor cardiac injury (AIS 1 and severe cardiac injury (AIS 2-6 are associated with higher rates. Severe blunt cardiac injury (AIS 4 and AIS 5-6 is associated with a higher mortality (OR 2.79 and 4.89, respectively as compared to the predicted average mortality (OR 2.49 of the study collective.Multiple injured patients with blunt cardiac trauma are at high risk to be underestimated. Careful evaluation of trauma patients is able to predict the presence of blunt cardiac injury. The severity of blunt cardiac injury needs to be stratified according to the AIS score, as the patients' outcome is dependent on the severity of cardiac injury.

  18. Delayed chest wall hematoma caused by progressive displacement of rib fractures after blunt trauma

    Directory of Open Access Journals (Sweden)

    Nobuhiro Sato

    2016-06-01

    Full Text Available Rib fracture is a common injury resulting from blunt thoracic trauma. Although hemothorax and pneumothorax are known delayed complications of rib fracture, delayed chest wall hematoma has rarely been reported. We discuss the case of an 81-year-old woman who was not undergoing antiplatelet or anticoagulant therapy who presented to our emergency department after a traffic injury. This patient had a nondisplaced rib fracture that went undetected on the initial computed tomography scan; the development of progressive displacement led to hemorrhagic shock due to delayed chest wall hematoma. The chest wall hematoma was effectively diagnosed and treated via contrast-enhanced computed tomography and angiographic embolization. This case highlights the possibility of this potential delayed complication from a common injury such as a rib fracture. Keywords: Angiography, Chest wall, Delayed complication, Rib fracture, Thoracic injury

  19. Drug-Intake Methods and Social Identity: The Use of Marijuana in Blunts among Southeast Asian Adolescents and Emerging Adults

    Science.gov (United States)

    Soller, Brian; Lee, Juliet P.

    2010-01-01

    This article examines why Southeast Asian American adolescents and emerging adults in two urban settings prefer to use "blunts," or hollowed-out cigars filled with marijuana, over other methods of drug intake. Rationales for preferring blunts were both instrumental and social. Blunts allowed users to more easily share marijuana, the preferred drug…

  20. Electrophysiology of blunted emotional bias in psychopathic personality.

    Science.gov (United States)

    Carolan, Patrick L; Jaspers-Fayer, Fern; Asmaro, Deyar T; Douglas, Kevin S; Liotti, Mario

    2014-01-01

    Diminished emotional capacity is a core characteristic of psychopathic personality. We examined behavioral and electrophysiological differences in attentional bias to emotional material in 34 healthy individuals rated high or low in psychopathic traits using the short form of the Psychopathic Personality Inventory-Revised (18 high-trait, 16 low-trait). While performing an emotional Stroop task, high-trait participants displayed reduced emotional modulation of the late positive potential (LPP, 400-600 ms), and early anterior positivity (EAP, 200-300 ms) amplitudes. Results suggest blunted bias to affective content in psychopathic personality, characterized by diminished early capture to emotional salience (EAP) and dampened cognitive emotional processing (LPP). Copyright © 2013 Society for Psychophysiological Research.