On-chip beamsplitter operation on single photons from quasi-resonantly excited quantum dots embedded in GaAs rib waveguides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rengstl, U.; Schwartz, M.; Herzog, T.

2015-07-13

We present an on-chip beamsplitter operating on a single-photon level by means of a quasi-resonantly driven InGaAs/GaAs quantum dot. The single photons are guided by rib waveguides and split into two arms by an evanescent field coupler. Although the waveguides themselves support the fundamental TE and TM modes, the measured degree of polarization (∼90%) reveals the main excitation and propagation of the TE mode. We observe the preserved single-photon nature of a quasi-resonantly excited quantum dot by performing a cross-correlation measurement on the two output arms of the beamsplitter. Additionally, the same quantum dot is investigated under resonant excitation, wheremore » the same splitting ratio is observed. An autocorrelation measurement with an off-chip beamsplitter on a single output arm reveal the single-photon nature after evanescent coupling inside the on-chip splitter. Due to their robustness, adjustable splitting ratio, and their easy implementation, rib waveguide beamsplitters with embedded quantum dots provide a promising step towards fully integrated quantum circuits.« less

Compact wavelength-insensitive fabrication-tolerant silicon-on-insulator beam splitter.

PubMed

Rasigade, Gilles; Le Roux, Xavier; Marris-Morini, Delphine; Cassan, Eric; Vivien, Laurent

2010-11-01

A star coupler-based beam splitter for rib waveguides is reported. A design method is presented and applied in the case of silicon-on-insulator rib waveguides. Experimental results are in good agreement with simulations. Excess loss lower than 1 dB is experimentally obtained for star coupler lengths from 0.5 to 1 μm. Output balance is better than 1 dB, which is the measurement accuracy, and broadband transmission is obtained over 90 nm.

Modeling of dispersion engineered chalcogenide rib waveguide for ultraflat mid-infrared supercontinuum generation in all-normal dispersion regime

NASA Astrophysics Data System (ADS)

Ahmad, H.; Karim, M. R.; Rahman, B. M. A.

2018-03-01

A rigorous numerical investigation has been carried out through dispersion engineering of chalcogenide rib waveguide for near-infrared to mid-infrared ultraflat broadband supercontinuum generation in all-normal group-velocity dispersion regime. We propose a novel design of a 1-cm-long air-clad rib waveguide which is made from {Ge}_{11.5} {As}_{24} {Se}_{64.5} chalcogenide glass as the core with either silica or {Ge}_{11.5} {As}_{24} {S}_{64.5} chalcogenide glass as a lower cladding separately. A broadband ultraflat supercontinuum spanning from 1300 to 1900 nm could be generated when pumped at 1.55 μ {m} with a low input peak power of 100 W. Shifting the pump to 2 μ {m}, the supercontinuum spectra extended in the mid-infrared region up to 3400 nm with a moderate-input peak power of 500 W. To achieve further extension in mid-infrared, we excite our optimized rib waveguide in both the anomalous and all-normal dispersion pumping regions at 3.1 μ {m} with a largest input peak power of 3 kW. In the case of anomalous dispersion region pumping, numerical analysis shows that supercontinuum spectrum can be extended in the mid-infrared up to 10 μ {m}, although this contains high spectral amplitude fluctuations over the entire bandwidth which limits the supercontinuum sources in the field of high precision measurement applications. On the other hand, by optimizing a rib waveguide geometry for pumping in all-normal dispersion region, we are able to generate a smooth and flat-top coherent supercontinuum spectrum with a moderate bandwidth spanning the wavelength range 2-5.5 μ {m} with less than 5 dB spectral fluctuation over the entire output bandwidth. Our proposed design is highly suitable for making on-chip SC light sources for a variety of applications such as biomedical imaging, and environmental and industrial sensing in the mid-infrared region.

Effects of design geometry on SU8 polymer waveguides

NASA Astrophysics Data System (ADS)

Holland, Anthony S.; Balkunje, Vishal S.; Mitchell, Arnan; Austin, Michael W.; Raghunathan, Mukund K.; Kostovski, Gorgi

2005-02-01

The spin-on photoresist SU8 from MicroChem has a relatively high refractive index (n=1.57 at 1550nm) compared with other polymers. It is stable and has high optical transmission at optical communication wavelengths. In this paper we study rib waveguides fabricated using SU8 as the core layer and thermoset polymers UV15 (n=1.50 at 1550nm) from Master Bond and NOA61 (n=1.54 at 1550nm) from Gentec as the cladding layers. The rib height is varied from 0.3 to 1.7μm high. This is part of the SU8 layer sandwiched between the cladding layers. The waveguides are tested to determine the effects of varying this geometry for single mode optical transmission. The lengths of the waveguides were 1.5 cm to 5 cm.

Surface trimming of silicon photonics devices using controlled reactive ion etching chemistry

NASA Astrophysics Data System (ADS)

Chandran, S.; Das, B. K.

2015-06-01

Surface trimming of rib waveguides fabricated in 5-μm SOI substrate has been carried out successfully without any significant increase of propagation losses. A reactive ion etching chemistry has been optimized for trimming and an empirical model has been developed to obtain the resulting waveguide geometries. This technique has been used to demonstrate smaller footprint devices like multimode interference based power splitters and ring resonators after defining them photolithographically with relatively large cross-section rib waveguides. We have been also successful to fabricate 2D tapered spot-size converter useful for monolithic integration of waveguides with varying heights and widths. The taper length is again precisely controlled by photolithographic definition. Minimum insertion loss of such a spot-size converter integrated between waveguides with 3-μm height difference has been recorded to be ∼2 dB. It has been also shown that the overall fiber-to-chip coupling loss can be reduced by >3 dB by using such spot-size converters at the input/output side of the waveguides.

Low loss poly-silicon for high performance capacitive silicon modulators.

PubMed

Douix, Maurin; Baudot, Charles; Marris-Morini, Delphine; Valéry, Alexia; Fowler, Daivid; Acosta-Alba, Pablo; Kerdilès, Sébastien; Euvrard, Catherine; Blanc, Romuald; Beneyton, Rémi; Souhaité, Aurélie; Crémer, Sébastien; Vulliet, Nathalie; Vivien, Laurent; Boeuf, Frédéric

2018-03-05

Optical properties of poly-silicon material are investigated to be integrated in new silicon photonics devices, such as capacitive modulators. Test structure fabrication is done on 300 mm wafer using LPCVD deposition: 300 nm thick amorphous silicon layers are deposited on thermal oxide, followed by solid phase crystallization anneal. Rib waveguides are fabricated and optical propagation losses measured at 1.31 µm. Physical analysis (TEM ASTAR, AFM and SIMS) are used to assess the origin of losses. Optimal deposition and annealing conditions have been defined, resulting in 400 nm-wide rib waveguides with only 9.2-10 dB/cm losses.

Deposition and characterization of silica-based films by helicon-activated reactive evaporation applied to optical waveguide fabrication.

PubMed

Bulla, Douglas A P; Li, Wei-Tang; Charles, Christine; Boswell, Rod; Ankiewicz, Adrian; Love, John

2004-05-10

Planar silicon dioxide optical waveguides were deposited by use of a plasma-activated reactive evaporation system, at a low deposition temperature and with reduced hydrogen contamination, on thermally oxidized silicon wafers. The deposited films show a refractive-index inhomogeneity of less than 0.1%, a thickness nonuniformity of less than 5%, and a material birefringence of approximately 5 x 10(-4). Rib-type channel waveguides were formed on the deposited films by means of hydrofluoric acid etching. The transmission loss of the rib waveguides is determined to be as low as 0.3 dB/cm at a wavelength of 1310 nm for TE polarization, after subtraction of the calculated leakage and scattering losses. Owing to the presence of the OH vibrational overtone band, an additional loss peak of 1 dB/cm is found near the 1385-nm wavelength. The experimental results of transmission loss at wavelengths of 1310 and 1550 nm are compared with analytic expressions for interface scattering and leakage loss.

GaN microring waveguide resonators bonded to silicon substrate by a two-step polymer process.

PubMed

Hashida, Ryohei; Sasaki, Takashi; Hane, Kazuhiro

2018-03-20

Using a polymer bonding technique, GaN microring waveguide resonators were fabricated on a Si substrate for future hybrid integration of GaN and Si photonic devices. The designed GaN microring consisted of a rib waveguide having a core of 510 nm in thickness, 1000 nm in width, and a clad of 240 nm in thickness. A GaN crystalline layer of 1000 nm in thickness was grown on a Si(111) substrate by metal organic chemical vapor deposition using a buffer layer of 300 nm in thickness for the compensation of lattice constant mismatch between GaN and Si crystals. The GaN/Si wafer was bonded to a Si(100) wafer by a two-step polymer process to prevent it from trapping air bubbles. The bonded GaN layer was thinned from the backside by a fast atom beam etching to remove the buffer layer and to generate the rib waveguides. The transmission characteristics of the GaN microring waveguide resonators were measured. The losses of the straight waveguides were measured to be 4.0±1.7  dB/mm around a wavelength of 1.55 μm. The microring radii ranged from 30 to 60 μm, where the measured free-spectral ranges varied from 2.58 to 5.30 nm. The quality factors of the microring waveguide resonators were from 1710 to 2820.

Ultracompact splitter for submicrometer silicon-on-insulator rib waveguides.

PubMed

Koster, Alain; Cassan, Eric; Laval, Suzanne; Vivien, Laurent; Pascal, Daniel

2004-11-01

An ultracompact and efficient 1 x 2 splitter for submicrometer silicon-on-insulator rib waveguides using a star coupler is reported. The structure proposed here is decidedly smaller than the usual splitters such as multi-mode interference or Y-branch devices and much less sensitive to technological fluctuations. Design of the compact splitter is optimized at lambda = 1.31 microm with the effective-index method and a two-dimensional beam-propagation method. The excess losses are lower than 0.15 dB, and the dependence of the losses on wavelength between 1.23 and 1.63 microm is almost flat (variation less than 0.04 dB), which makes the device very interesting for coarse wavelength-division multiplexing applications within the silicon photonic technology.

Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide

NASA Astrophysics Data System (ADS)

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Jeong Kim, Un; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

2015-07-01

We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a “plasmonic via” in plasmonic nanocircuits.

Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide.

PubMed

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Kim, Un Jeong; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

2015-07-02

We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a "plasmonic via" in plasmonic nanocircuits.

Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide

PubMed Central

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Jeong Kim, Un; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

2015-01-01

We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a “plasmonic via” in plasmonic nanocircuits. PMID:26135115

Calculated coupling efficiency between an elliptical-core optical fiber and an optical waveguide over temperature

NASA Technical Reports Server (NTRS)

Tuma, Margaret L.; Weisshaar, Andreas; Li, Jian; Beheim, Glenn

1995-01-01

To determine the feasibility of coupling the output of a single-mode optical fiber into a single-mode rib waveguide in a temperature varying environment, a theoretical calculation of the coupling efficiency between the two was investigated. Due to the complex geometry of the rib guide, there is no analytical solution to the wave equation for the guided modes, thus, approximation and/or numerical techniques must be utilized to determine the field patterns of the guide. In this study, three solution methods were used for both the fiber and guide fields; the effective-index method (EIM), Marcatili's approximation, and a Fourier method. These methods were utilized independently to calculate the electric field profile of each component at two temperatures, 20 C and 300 C, representing a nominal and high temperature. Using the electric field profile calculated from each method, the theoretical coupling efficiency between an elliptical-core optical fiber and a rib waveguide was calculated using the overlap integral and the results were compared. It was determined that a high coupling efficiency can be achieved when the two components are aligned. The coupling efficiency was more sensitive to alignment offsets in the y direction than the x, due to the elliptical modal field profile of both components. Changes in the coupling efficiency over temperature were found to be minimal.

Midinfrared wavelength conversion in hydrogenated amorphous silicon waveguides

NASA Astrophysics Data System (ADS)

Wang, Jiang; Wang, Zhaolu; Huang, Nan; Han, Jing; Li, Yongfang; Liu, Hongjun

2017-10-01

Midinfrared (MIR) wavelength conversion based on degenerate four-wave mixing is theoretically investigated in hydrogenated amorphous silicon (a-Si:H) waveguides. The broadband phase mismatch is achieved in the normal group-velocity dispersion regime. The conversion bandwidth is extended to 900 nm, and conversion efficiency of up to -14 dB with a pump power of 70 mW in a 2-mm long a-Si:H rib waveguides is obtained. This low-power on-chip wavelength converter will have potential for application in a wide range of MIR nonlinear optic devices.

Silicon on silicon dioxide slot waveguide evanescent field gas absorption sensor

NASA Astrophysics Data System (ADS)

Butt, M. A.; Khonina, S. N.; Kazanskiy, N. L.

2018-01-01

Several trace gases such as H2O, CO, CO2, NO, N2O, NO2 and CH4 strongly absorb in the mid-IR spectral region due to their fundamental rotational and vibrational transitions. In this work, we propose an evanescent field absorption gas sensor based on silicon/silicon dioxide slot waveguide at 3.39 μm for sensing of methane gas. These waveguides can provide the highest evanescent field ratio (EFR) > 47% with adequate dimensions. Higher EFR values often come at an expense of higher propagation losses. These waveguides have relatively higher losses as compared to conventional waveguides, such as rib and slab waveguides, as these fundamental losses are static and the proposed sensing mechanism is established on the incremental loss due to the absorption of the gas. Therefore, incident power can always be incremented to compensate the waveguide losses.

Efficient channel-waveguide laser in Nd:GGG at 1.062 μm wavelength

NASA Astrophysics Data System (ADS)

Gerhardt, R.; Kleine-Börger, J.; Beilschmidt, L.; Frommeyer, M.; Dötsch, H.; Gather, B.

1999-08-01

Channel waveguide lasers in crystals of neodymium-doped gadolinium-gallium-garnet are realized. They are based on single-mode rib waveguides prepared by liquid phase epitaxy. By this growth technique the incorporation of certain impurities, which may cause severe quenching, is inevitable. The dominant quenching process could be identified and eliminated. Channel waveguides with extremely low losses, down to 0.25 dB/cm for both TE and TM modes, are fabricated by ion-beam etching. As a result, low thresholds of 5 mW and high slope efficiencies of 48% at the laser wavelength of 1.062 μm could be achieved when pumping at a wavelength of 807 nm.

Raman mediated all-optical cascadable inverter using silicon-on-insulator waveguides.

PubMed

Sen, Mrinal; Das, Mukul K

2013-12-01

In this Letter, we propose an all-optical circuit for a cascadable and integrable logic inverter based on stimulated Raman scattering. A maximum product criteria for noise margin is taken to analyze the cascadability of the inverter. Variation of noise margin for different model parameters is also studied. Finally, the time domain response of the inverter is analyzed for different widths of input pulses.

Free-standing GaN grating couplers and rib waveguide for planar photonics at telecommunication wavelength

NASA Astrophysics Data System (ADS)

Liu, Qifa; Wang, Wei

2018-01-01

Gallium Nitride (GaN) free-standing planar photonic device at telecommunication wavelength based on GaN-on-silicon platform was presented. The free-standing structure was realized by particular double-side fabrication process, which combining GaN front patterning, Si substrate back releasing and GaN slab etching. The actual device parameters were identified via the physical characterizations employing scanning electron microscope (SEM), atomic force microscope (AFM) and reflectance spectra testing. High coupling efficiency and good light confinement properties of the gratings and rib waveguide at telecommunication wavelength range were verified by finite element method (FEM) simulation. This work illustrates the potential of new GaN photonic structure which will enable new functions for planar photonics in communication and sensing applications, and is favorable for the realization of integrated optical circuit.

INTERNATIONAL CONFERENCE ON SEMICONDUCTOR INJECTION LASERS SELCO-87: Low-threshold ridge-waveguide 1.3-μm laser

NASA Astrophysics Data System (ADS)

Kortàn, J.; Nohavica, D.; Sarma, J.

1988-11-01

A description is given of the fabrication and of the main properties of 1.3-μm GaInAsP lasers with a ridge (rib) waveguide structure used for lateral confinement of transverse modes and of the current. Such lasers were made by the method of ion-beam etching and self-alignment photolithography. Narrow ridges (3-5 μm) formed in this way carried Ti-Au Schottky contacts. These lasers were simple to fabricate and their threshold currents were comparable with those in much more complex lasers with buried waveguide structures.

Polymer taper bridge for silicon waveguide to single mode waveguide coupling

NASA Astrophysics Data System (ADS)

Kruse, Kevin; Middlebrook, Christopher T.

2016-03-01

Coupling of optical power from high-density silicon waveguides to silica optical fibers for signal routing can incur high losses and often requires complex end-face preparation/processing. Novel coupling device taper structures are proposed for low coupling loss between silicon photonic waveguides and single mode fibers are proposed and devices are fabricated and measured in terms of performance. Theoretical mode conversion models for waveguide tapers are derived for optimal device structure design and performance. Commercially viable vertical and multi-layer taper designs using polymer waveguide materials are proposed as innovative, cost-efficient, and mass-manufacturable optical coupling devices. The coupling efficiency for both designs is determined to evaluate optimal device dimensions and alignment tolerances with both silicon rib waveguides and silicon nanowire waveguides. Propagation loss as a function of waveguide roughness and metallic loss are determined and correlated to waveguide dimensions to obtain total insertion loss for the proposed taper designs. Multi-layer tapers on gold-sputtered substrates are fabricated through photolithography as proof-of-concept devices and evaluated for device loss optimization. Tapered waveguide coupling loss with Si WGs (2.74 dB) was experimentally measured with high correlation to theoretical results.

Long-wave infrared 1 × 2 MMI based on air-gap beneath silicon rib waveguides

NASA Astrophysics Data System (ADS)

Wei, Yuxin; Li, Guoyi; Hao, Yinlei; Li, Yubo; Yang, Jianyi; Wang, Minghua; Jiang, Xiaoqing

2011-08-01

The undercut long-wave infrared (LWIR) waveguide components with air-gap beneath are analyzed and fabricated on the Si-wafer with simple manufacturing process. A 1 × 2 multimode interference (MMI) splitter based on this structure is presented and measured under the 10.6μm wavelength experimental setup. The uniformity of the MMI fabricated is 0.76 dB. The relationship among the output power, slab thickness and air-gap width is also fully discussed. Furthermore, undercut straight waveguides based on SOI platform are fabricated for propagation loss evaluation. Ways to reduce the loss are discussed either.

Photosensitive adhesive bonding process of magnetooptic waveguides with Si guiding layer for optical nonreciprocal devices

NASA Astrophysics Data System (ADS)

Choowitsakunlert, Salinee; Takagiwa, Kenji; Kobashigawa, Takuya; Hosoya, Nariaki; Silapunt, Rardchawadee; Yokoi, Hideki

2018-05-01

A photosensitive adhesive bonding process for a magnetooptic waveguide for an optical isolator employing a nonreciprocal guided-radiation mode conversion is investigated at 1.55 µm. The magnetooptic waveguide is a straight rib type, and it is fabricated by bonding the Si guiding layer to a magnetic garnet. In the fabrication process, an adhesive material is diluted to obtain a certain thickness before depositing on a silicon-on-insulator (SOI) substrate. The relationship between the percent dilution ratio and the thickness of the adhesive layer is considered. The smallest gap thickness is found to be 0.66 µm at a dilution ratio of 2%.

DAPHNE silicon photonics technological platform for research and development on WDM applications

NASA Astrophysics Data System (ADS)

Baudot, Charles; Fincato, Antonio; Fowler, Daivid; Perez-Galacho, Diego; Souhaité, Aurélie; Messaoudène, Sonia; Blanc, Romuald; Richard, Claire; Planchot, Jonathan; De-Buttet, Come; Orlando, Bastien; Gays, Fabien; Mezzomo, Cécilia; Bernard, Emilie; Marris-Morini, Delphine; Vivien, Laurent; Kopp, Christophe; Boeuf, Frédéric

2016-05-01

A new technological platform aimed at making prototypes and feasibility studies has been setup at STMicroelectronics using 300mm wafer foundry facilities. The technology, called DAPHNE (Datacom Advanced PHotonic Nanoscale Environment), is devoted at developing and evaluating new devices and sub-systems in particular for wavelength division multiplexing (WDM) applications and ring resonator based applications. Developed in the course of PLAT4MFP7 European project, DAPHNE is a flexible platform that fits perfectly R&D needs. The fabrication flow enables the processing of photonic integrated circuits using a silicon-on-insulator (SOI) of 300nm, partial etches of 150nm and 50nm and a total silicon etching. Consequently, two varieties of rib waveguides and one strip waveguide can be fabricated simultaneously with auto-alignment properties. The process variability on the 150nm partially etched silicon and the thin 50nm slab region are both less than 6 nm. Using a variety of different implantation configurations and a back-end of line of 5 metal layers, active devices are fabricated both in germanium and silicon. An available far back-end of line process consists of making 20 μm diameter copper posts on top of the electrical pads so that an electronic integrated circuit can be bonded on top the photonic die by 3D integration. Besides having those fabrication process options, DAPHNE is equipped with a library of standard cells for optical routing and multiplexing. Moreover, typical Mach-Zehnder modulators based on silicon pn junctions are also available for optical signal modulation. To achieve signal detection, germanium photodetectors also exist as standard cells. The measured single-mode propagation losses are 3.5 dB/cm for strip, 3.7 dB/cm for deep-rib (50nm slab) and 1.4 dB/cm for standard rib (150nm slab) waveguides. Transition tapers between different waveguide structures are as low as 0.006 dB.

Mid-infrared supercontinuum generation in tapered As2S3 chalcogenide planar waveguide

NASA Astrophysics Data System (ADS)

Zhang, Xiang; Hu, Hongyu; Li, Wenbo; Dutta, Niloy K.

2016-10-01

We numerically demonstrate mid-infrared supercontinuum generation in a non-uniformly tapered chalcogenide planar waveguide. This planar rib waveguide of As2S3 glass on MgF2 is 2 cm long with increasing etch depth longitudinally to manage the total dispersion. This waveguide has zero dispersion at two wavelengths. The dispersion profile varies along the propagation distance, leading to continuous modification of the phase-matching condition for dispersive wave emission and enhancement of energy transfer efficiency between solitons and dispersive waves. Numerical simulations are conducted for secant input pulses at a wavelength of 1.55 μm with a width of 50 fs and peak power of 2 kW. Results show this proposed scheme significantly broadens the generated continuum, extending from ~1 to ~7 μm.

Spectroscopy of high index contrast Yb:Ta2O5 waveguides for lasing applications

NASA Astrophysics Data System (ADS)

Aghajani, A.; Murugan, G. S.; Sessions, N. P.; Apostolopoulos, V.; Wilkinson, J. S.

2015-06-01

Ytterbium-doped waveguides are required for compact integrated lasers and Yb- doped Ta2O5 is a promising candidate material. The design, fabrication and spectroscopic characterisation of Yb:Ta2O5 rib waveguides are described. The peak absorption cross-section was measured to be 2.75×10-20 cm2 at 975 nm. The emission spectrum was found to have a fluorescence emission peak at a wavelength of 976 nm with a peak cross-section of 2.9×10-20 cm2 and a second broad fluorescence band spanning from 990 nm to 1090 nm. The excited- state life time was measured to be 260 μs.

Optimization of silicon waveguides for gas detection application at mid-IR wavelengths

NASA Astrophysics Data System (ADS)

Butt, M. A.; Kozlova, E. S.

2018-04-01

There are several trace gases such as N2O, CO, CO2, NO, H2O, NO2, NH3, CH4 etc. which have their absorption peaks in Mid-IR spectrum These gases strongly absorb in the mid-IR > 2.5 μm spectral region due to their fundamental rotational and vibrational transitions. In this work, we modelled and optimized three different kinds of waveguides such as rib, strip and slot based on silicon platform to obtain maximum evanescent field ratio. These waveguides are designed at 3.39 μm and 4.67 μm which correspond to the absorption line of methane (CH4) and carbon monoxide (CO) respectively.

Optical waveguide loop for planar trapping of blood cells and microspheres

NASA Astrophysics Data System (ADS)

Ahluwalia, Balpreet S.; Hellesø, Olav G.

2013-09-01

The evanescent field from a waveguide can be used to trap and propel a particle. An optical waveguide loop with an intentional gap at the center is used for planar transport and stable trapping of particles. The waveguide acts as a conveyor belt to trap and deliver spheres towards the gap. At the gap, the counter-diverging light fields hold the sphere at a fixed position. Numerical simulation based on the finite element method was performed in three dimensions using a computer cluster. The field distribution and optical forces for rib and strip waveguide designs are compared and discussed. The optical force on a single particle was computed for various positions of the particle in the gap. Simulation predicted stable trapping of particles in the gap. Depending on the gap separation (2-50 μm) a single or multiple spheres and red blood cells were trapped at the gap. Waveguides were made of tantalum pentaoxide material. The waveguides are only 180 nm thick and thus could be integrated with other functions on the chip.

Hot-embossing fabrication of chalcogenide glasses rib waveguide for mid-infrared molecular sensing

NASA Astrophysics Data System (ADS)

Yan, Ting-Yang; Shen, Xiang; Wang, Rong-Ping; Wang, Guo-Xiang; Dai, Shi-Xun; Xu, Tie-Feng; Nie, Qiu-Hua

2017-02-01

Not Available Project supported by the National Natural Science Foundation of China (Grant No. 61377061), the Public Project of Zhejiang Province, China (Grant No. 2014C31146), and sponsored by K. C. Wong Magna Fund in Ningbo University, China.

Graphene-assisted ultra-compact polarization splitter and rotator with an extended bandwidth.

PubMed

Zhang, Tian; Ke, Xianmin; Yin, Xiang; Chen, Lin; Li, Xun

2017-09-22

The high refraction-index contrast between silicon and the surrounding cladding makes silicon-on-insulator devices highly polarization-dependent. However, it is greatly desirable for many applications to address the issue of polarization dependence in silicon photonics. Here, a novel ultra-compact polarization splitter and rotator (PSR), constructed with an asymmetrical directional coupler consisting of a rib silicon waveguide and a graphene-embedded rib silicon waveguide (GERSW), on a silicon-on-insulator platform is proposed and investigated. By taking advantage of the large modulation of the effective refractive index of the TE mode for the GERSW by tuning the chemical potential of graphene, the phase matching condition can be well satisfied over a wide spectral band. The presented result demonstrates that for a 7-layer-graphene-embedded PSR with a coupling length of 11.1 μm, a high TM-to-TE conversion efficiency (>-0.5 dB) can be achieved over a broad bandwidth from 1516 to 1602 nm.

Optical gain at 650 nm from a polymer waveguide with dye-doped cladding

NASA Astrophysics Data System (ADS)

Reilly, M. A.; Coleman, B.; Pun, E. Y. B.; Penty, R. V.; White, I. H.; Ramon, M.; Xia, R.; Bradley, D. D. C.

2005-12-01

Signal amplification at the polymer optical fiber low-loss window of 650 nm is reported in an SU8 rib waveguide coated with Rhodamine-640 doped poly(methyl methacrylate). A signal beam is end-fired into the facet of a 7×100μm waveguide and amplified by top pumping of the 2-μm-thick cladding region with a pulsed pump source focused into a 9-mm-long stripe. A gain of 14dB and a minimum signal-to-noise ratio of around 2 dB are achieved in a 15-mm-long device with a low threshold pump intensity of 0.25μJ/mm2, which is an order of magnitude lower than previously reported.

Amorphous silicon as high index photonic material

NASA Astrophysics Data System (ADS)

Lipka, T.; Harke, A.; Horn, O.; Amthor, J.; Müller, J.

2009-05-01

Silicon-on-Insulator (SOI) photonics has become an attractive research topic within the area of integrated optics. This paper aims to fabricate SOI-structures for optical communication applications with lower costs compared to standard fabrication processes as well as to provide a higher flexibility with respect to waveguide and substrate material choice. Amorphous silicon is deposited on thermal oxidized silicon wafers with plasma-enhanced chemical vapor deposition (PECVD). The material is optimized in terms of optical light transmission and refractive index. Different a-Si:H waveguides with low propagation losses are presented. The waveguides were processed with CMOS-compatible fabrication technologies and standard DUV-lithography enabling high volume production. To overcome the large mode-field diameter mismatch between incoupling fiber and sub-μm waveguides three dimensional, amorphous silicon tapers were fabricated with a KOH etched shadow mask for patterning. Using ellipsometric and Raman spectroscopic measurements the material properties as refractive index, layer thickness, crystallinity and material composition were analyzed. Rapid thermal annealing (RTA) experiments of amorphous thin films and rib waveguides were performed aiming to tune the refractive index of the deposited a-Si:H waveguide core layer after deposition.

Photonic-chip-based all-optical ultra-wideband pulse generation via XPM and birefringence in a chalcogenide waveguide.

PubMed

Tan, Kang; Marpaung, David; Pant, Ravi; Gao, Feng; Li, Enbang; Wang, Jian; Choi, Duk-Yong; Madden, Steve; Luther-Davies, Barry; Sun, Junqiang; Eggleton, Benjamin J

2013-01-28

We report a photonic-chip-based scheme for all-optical ultra-wideband (UWB) pulse generation using a novel all-optical differentiator that exploits cross-phase modulation and birefringence in an As₂S₃ chalcogenide rib waveguide. Polarity-switchable UWB monocycles and doublets were simultaneously obtained with single optical carrier operation. Moreover, transmission over 40-km fiber of the generated UWB doublets is demonstrated with good dispersion tolerance. These results indicate that the proposed approach has potential applications in multi-shape, multi-modulation and long-distance UWB-over-fiber communication systems.

16-channel arrayed waveguide grating (AWG) demultiplexer design on SOI wafer for application in CWDM-PON

NASA Astrophysics Data System (ADS)

Juhari, Nurjuliana; Menon, P. Susthitha; Ehsan, Abang Annuar; Shaari, Sahbudin

2015-01-01

Arrayed Waveguide Grating (AWG) functioning as a demultiplexer is designed on SOI platform with rib waveguide structure to be utilized in coarse wavelength division multiplexing-passive optical network (CWDM-PON) systems. Two design approaches; conventional and tapered configuration of AWG was developed with channel spacing of 20 nm that covers the standard transmission spectrum of CWDM ranging from 1311 nm to 1611 nm. The performance of insertion loss for tapered configuration offered the lowest insertion loss of 0.77 dB but the adjacent crosstalk gave non-significant relation for both designs. With average channel spacing of 20.4 nm, the nominal central wavelength of this design is close to the standard CWDM wavelength grid over 484 nm free spectrum range (FSR).

Electrically driven hybrid Si/III-V Fabry-Pérot lasers based on adiabatic mode transformers.

PubMed

Ben Bakir, B; Descos, A; Olivier, N; Bordel, D; Grosse, P; Augendre, E; Fulbert, L; Fedeli, J M

2011-05-23

We report the first demonstration of an electrically driven hybrid silicon/III-V laser based on adiabatic mode transformers. The hybrid structure is formed by two vertically superimposed waveguides separated by a 100-nm-thick SiO2 layer. The top waveguide, fabricated in an InP/InGaAsP-based heterostructure, serves to provide optical gain. The bottom Si-waveguides system, which supports all optical functions, is constituted by two tapered rib-waveguides (mode transformers), two distributed Bragg reflectors (DBRs) and a surface-grating coupler. The supermodes of this hybrid structure are controlled by an appropriate design of the tapers located at the edges of the gain region. In the middle part of the device almost all the field resides in the III-V waveguide so that the optical mode experiences maximal gain, while in regions near the III-V facets, mode transformers ensure an efficient transfer of the power flow towards Si-waveguides. The investigated device operates under quasi-continuous wave regime. The room temperature threshold current is 100 mA, the side-mode suppression ratio is as high as 20 dB, and the fiber-coupled output power is ~7 mW.

On-Chip Waveguide Coupling of a Layered Semiconductor Single-Photon Source.

PubMed

Tonndorf, Philipp; Del Pozo-Zamudio, Osvaldo; Gruhler, Nico; Kern, Johannes; Schmidt, Robert; Dmitriev, Alexander I; Bakhtinov, Anatoly P; Tartakovskii, Alexander I; Pernice, Wolfram; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf

2017-09-13

Fully integrated quantum technology based on photons is in the focus of current research, because of its immense potential concerning performance and scalability. Ideally, the single-photon sources, the processing units, and the photon detectors are all combined on a single chip. Impressive progress has been made for on-chip quantum circuits and on-chip single-photon detection. In contrast, nonclassical light is commonly coupled onto the photonic chip from the outside, because presently only few integrated single-photon sources exist. Here, we present waveguide-coupled single-photon emitters in the layered semiconductor gallium selenide as promising on-chip sources. GaSe crystals with a thickness below 100 nm are placed on Si 3 N 4 rib or slot waveguides, resulting in a modified mode structure efficient for light coupling. Using optical excitation from within the Si 3 N 4 waveguide, we find nonclassicality of generated photons routed on the photonic chip. Thus, our work provides an easy-to-implement and robust light source for integrated quantum technology.

Fabrication and demonstration of 1 × 8 silicon-silica multi-chip switch based on optical phased array

NASA Astrophysics Data System (ADS)

Katayose, Satomi; Hashizume, Yasuaki; Itoh, Mikitaka

2016-08-01

We experimentally demonstrated a 1 × 8 silicon-silica hybrid thermo-optic switch based on an optical phased array using a multi-chip integration technique. The switch consists of a silicon chip with optical phase shifters and two silica-based planar lightwave circuit (PLC) chips composed of optical couplers and fiber connections. We adopted a rib waveguide as the silicon waveguide to reduce the coupling loss and increase the alignment tolerance for coupling between silicon and silica waveguides. As a result, we achieved a fast switching response of 81 µs, a high extinction ratio of over 18 dB and a low insertion loss of 4.9-8.1 dB including a silicon-silica coupling loss of 0.5 ± 0.3 dB at a wavelength of 1.55 µm.

Optical modulation in silicon waveguides via charge state control of deep levels.

PubMed

Logan, D F; Jessop, P E; Knights, A P; Wojcik, G; Goebel, A

2009-10-12

The control of defect mediated optical absorption at a wavelength of 1550 nm via charge state manipulation is demonstrated using optical absorption measurements of indium doped Silicon-On-Insulator (SOI) rib waveguides. These measurements introduce the potential for modulation of waveguide transmission by using the local depletion and injection of free-carriers to change deep-level occupancy. The extinction ratio and modulating speed are simulated for a proposed device structure. A 'normally-off' depletion modulator is described with an extinction coefficient limited to 5 dB/cm and switching speeds in excess of 1 GHz. For a carrier injection modulator a fourfold enhancement in extinction ratio is provided relative to free carrier absorption alone. This significant improvement in performance is achieved with negligible increase in driving power but slightly degraded switching speed.

High-speed all-optical logic inverter based on stimulated Raman scattering in silicon nanocrystal.

PubMed

Sen, Mrinal; Das, Mukul K

2015-11-01

In this paper, we propose a new device architecture for an all-optical logic inverter (NOT gate), which is cascadable with a similar device. The inverter is based on stimulated Raman scattering in silicon nanocrystal waveguides, which are embedded in a silicon photonic crystal structure. The Raman response function of silicon nanocrystal is evaluated to explore the transfer characteristic of the inverter. A maximum product criterion for the noise margin is taken to analyze the cascadability of the inverter. The time domain response of the inverter, which explores successful inversion operation at 100 Gb/s, is analyzed. Propagation delay of the inverter is on the order of 5 ps, which is less than the delay in most of the electronic logic families as of today. Overall dimension of the device is around 755  μm ×15  μm, which ensures integration compatibility with the matured silicon industry.

Optical NAND gate

DOEpatents

Skogen, Erik J [Albuquerque, NM; Raring, James [Goleta, CA; Tauke-Pedretti, Anna [Albuquerque, NM

2011-08-09

An optical NAND gate is formed from two pair of optical waveguide devices on a substrate, with each pair of the optical waveguide devices consisting of an electroabsorption modulator and a photodetector. One pair of the optical waveguide devices is electrically connected in parallel to operate as an optical AND gate; and the other pair of the optical waveguide devices is connected in series to operate as an optical NOT gate (i.e. an optical inverter). The optical NAND gate utilizes two digital optical inputs and a continuous light input to provide a NAND function output. The optical NAND gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

Surface acoustic waves in acoustic superlattice lithium niobate coated with a waveguide layer

NASA Astrophysics Data System (ADS)

Yang, G. Y.; Du, J. K.; Huang, B.; Jin, Y. A.; Xu, M. H.

2017-04-01

The effects of the waveguide layer on the band structure of Rayleigh waves are studied in this work based on a one-dimensional acoustic superlattice lithium niobate substrate coated with a waveguide layer. The present phononic structure is formed by the periodic domain-inverted single crystal that is the Z-cut lithium niobate substrate with a waveguide layer on the upper surface. The plane wave expansion method (PWE) is adopted to determine the band gap behavior of the phononic structure and validated by the finite element method (FEM). The FEM is also used to investigate the transmission of Rayleigh waves in the phononic structure with the interdigital transducers by means of the commercial package COMSOL. The results show that, although there is a homogeneous waveguide layer on the surface, the band gap of Rayleigh waves still exist. It is also found that increasing the thickness of the waveguide layer, the band width narrows and the band structure shifts to lower frequency. The present approach can be taken as an efficient tool in designing of phononic structures with waveguide layer.

Babinet-inverted optical Yagi-Uda antenna for unidirectional radiation to free space.

PubMed

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Choe, Jong-Ho; Lee, Jongcheon; Lee, Jaesoong; Jeong, Heejeong; Kim, Un Jeong; Park, Yeonsang; Song, In Yong; Park, Q-Han; Hwang, Sung Woo; Kim, Kinam; Lee, Chang-Won

2014-06-11

Nanophotonics capable of directing radiation or enhancing quantum-emitter transition rates rely on plasmonic nanoantennas. We present here a novel Babinet-inverted magnetic-dipole-fed multislot optical Yagi-Uda antenna that exhibits highly unidirectional radiation to free space, achieved by engineering the relative phase of the interacting surface plasmon polaritons between the slot elements. The unique features of this nanoantenna can be harnessed for realizing energy transfer from one waveguide to another by working as a future "optical via".

Photo-induced reduction of graphene oxide coating on optical waveguide and consequent optical intermodulation

PubMed Central

Chong, W. Y.; Lim, W. H.; Yap, Y. K.; Lai, C. K.; De La Rue, R. M.; Ahmad, H.

2016-01-01

Increased absorption of transverse-magnetic (TM) - polarised light by a graphene-oxide (GO) coated polymer waveguide has been observed in the presence of transverse-electric (TE) - polarised light. The GO-coated waveguide exhibits very strong photo-absorption of TE-polarised light - and acts as a TM-pass waveguide polariser. The absorbed TE-polarised light causes a significant temperature increase in the GO film and induces thermal reduction of the GO, resulting in an increase in optical-frequency conductivity and consequently increased optical propagation loss. This behaviour in a GO-coated waveguide gives the action of an inverted optical switch/modulator. By varying the incident TE-polarised light power, a maximum modulation efficiency of 72% was measured, with application of an incident optical power level of 57 mW. The GO-coated waveguide was able to respond clearly to modulated TE-polarised light with a pulse duration of as little as 100 μs. In addition, no wavelength dependence was observed in the response of either the modulation (TE-polarised light) or the signal (TM-polarised light). PMID:27034015

Electromagnetic modeling of waveguide amplifier based on Nd3+ Si-rich SiO2 layers by means of the ADE-FDTD method.

PubMed

Dufour, Christian; Cardin, Julien; Debieu, Olivier; Fafin, Alexandre; Gourbilleau, Fabrice

2011-04-04

By means of ADE-FDTD method, this paper investigates the electromagnetic modelling of a rib-loaded waveguide composed of a Nd3+ doped Silicon Rich Silicon Oxide active layer sandwiched between a SiO2 bottom cladding and a SiO2 rib. The Auxilliary Differential Equations are the rate equations which govern the levels populations. The Finite Difference Time Domain (FDTD) scheme is used to solve the space and time dependent Maxwell equations which describe the electromagnetic field in a copropagating scheme of both pumping (λpump = 488 nm) and signal (λsignal = 1064 nm) waves. Such systems are characterized by extremely different specific times such as the period of electromagnetic field ~ 10-15 s and the lifetimes of the electronic levels between ~ 10-10s and ~ 10-4 s. The time scaling method is used in addition to specific initial conditions in order to decrease the computational time. We show maps of the Poynting vector along the propagation direction as a function of the silicon nanograin (Si-ng) concentrations. A threshold value of 1024 Si-ng m-3 is extracted below which the pump wave can propagate so that a signal amplication is possible.

Electromagnetic modeling of waveguide amplifier based on Nd3+ Si-rich SiO2 layers by means of the ADE-FDTD method

PubMed Central

2011-01-01

By means of ADE-FDTD method, this paper investigates the electromagnetic modelling of a rib-loaded waveguide composed of a Nd3+ doped Silicon Rich Silicon Oxide active layer sandwiched between a SiO2 bottom cladding and a SiO2 rib. The Auxilliary Differential Equations are the rate equations which govern the levels populations. The Finite Difference Time Domain (FDTD) scheme is used to solve the space and time dependent Maxwell equations which describe the electromagnetic field in a copropagating scheme of both pumping (λpump = 488 nm) and signal (λsignal = 1064 nm) waves. Such systems are characterized by extremely different specific times such as the period of electromagnetic field ~ 10-15 s and the lifetimes of the electronic levels between ~ 10-10s and ~ 10-4 s. The time scaling method is used in addition to specific initial conditions in order to decrease the computational time. We show maps of the Poynting vector along the propagation direction as a function of the silicon nanograin (Si-ng) concentrations. A threshold value of 1024 Si-ng m-3 is extracted below which the pump wave can propagate so that a signal amplication is possible. PMID:21711829

InP-based photonic integrated circuit platform on SiC wafer.

PubMed

Takenaka, Mitsuru; Takagi, Shinichi

2017-11-27

We have numerically investigated the properties of an InP-on-SiC wafer as a photonic integrated circuit (PIC) platform. By bonding a thin InP-based semiconductor on a SiC wafer, SiC can be used as waveguide cladding, a heat sink, and a support substrate simultaneously. Since the refractive index of SiC is sufficiently low, PICs can be fabricated using InP-based strip and rib waveguides with a minimum bend radius of approximately 7 μm. High-thermal-conductivity SiC underneath an InP-based waveguide core markedly improves heat dissipation, resulting in superior thermal properties of active devices such as laser diodes. The InP-on-SiC wafer has significantly smaller thermal stress than InP-on-SiO 2 /Si wafer, which prevents the thermal degradation of InP-based devices during high-temperature processes. Thus, InP on SiC provides an ideal platform for high-performance PICs.

Vibroacoustics of the piano soundboard: Reduced models, mobility synthesis, and acoustical radiation regime

NASA Astrophysics Data System (ADS)

Boutillon, Xavier; Ege, Kerem

2013-09-01

In string musical instruments, the sound is radiated by the soundboard, subject to the strings excitation. This vibration of this rather complex structure is described here with models which need only a small number of parameters. Predictions of the models are compared with the results of experiments that have been presented in Ege et al. [Vibroacoustics of the piano soundboard: (non)linearity and modal properties in the low- and mid-frequency ranges, Journal of Sound and Vibration 332 (5) (2013) 1288-1305]. The apparent modal density of the soundboard of an upright piano in playing condition, as seen from various points of the structure, exhibits two well-separated regimes, below and above a frequency flim that is determined by the wood characteristics and by the distance between ribs. Above flim, most modes appear to be localised, presumably due to the irregularity of the spacing and height of the ribs. The low-frequency regime is predicted by a model which consists of coupled sub-structures: the two ribbed areas split by the main bridge and, in most cases, one or two so-called cut-off corners. In order to assess the dynamical properties of each of the subplates (considered here as homogeneous plates), we propose a derivation of the (low-frequency) modal density of an orthotropic homogeneous plate which accounts for the boundary conditions on an arbitrary geometry. Above flim, the soundboard, as seen from a given excitation point, is modelled as a set of three structural wave-guides, namely the three inter-rib spacings surrounding the excitation point. Based on these low- and high-frequency models, computations of the point-mobility and of the apparent modal densities seen at several excitation points match published measurements. The dispersion curve of the wave-guide model displays an acoustical radiation scheme which differs significantly from that of a thin homogeneous plate. It appears that piano dimensioning is such that the subsonic regime of acoustical radiation extends over a much wider frequency range than it would be for a homogeneous plate with the same low-frequency vibration. One problem in piano manufacturing is examined in relationship with the possible radiation schemes induced by the models.

Fabrication of optical ring resonators in silicon on insulator

NASA Astrophysics Data System (ADS)

Headley, William R.; Reed, Graham T.; Liu, Ansheng; Cohen, Oded; Hak, D.; Paniccia, Mario J.; Howe, Simon; Huille, Inga

2004-07-01

In an effort to determine low-cost alternatives for components currently used in DWDM, optical ring resonators are currently being investigated. The well-known microfabrication techniques of silicon, coupled with the low propagation loss of single crystal silicon, make SOI an attractive material. Laterally coupled racetrack resonators utilising rib waveguides have been fabricated and preliminary results are discussed. An extinction ratio of 15.9 dB and a finesse of 11 have been measured.

Solid State Research, 1980:4

DTIC Science & Technology

1980-10-31

and is initiated at the periphery of the de- vice at opening in the SijNj layer. Rate measurement* of thi* prove** made on the GKOUSS imager using...dimensions, single-mode opera- tion can be obtained. There is a stripe opening in the oxide film running parallel to the etched rib, which can be...seen in cross section in Fig. I-l(a). This stripe opening is the nucleation region for the epitaxial growth. Other oxide-confined waveguide

Tunable Stimulated Brillouin Scattering in Planar Optical Circuits

DTIC Science & Technology

2012-11-01

interaction, making it the material of choice for chip-scale SBS. SBS was characterized in a 7 cm long As2S3 rib waveguide using the backscattered ...spectrum and pump-probe measurements. Figure 2(a) shows the backscattered signal demonstrating the generation of Stokes signal as the average pump...power is increased; pulsed pump with a duty cycle of 1% and pulse width of 400ns was used for backscattering experiment. From the backscattered

Polymer electro-optic waveguide devices: Low-loss etchless fabrication techniques and passive-to-active integration

NASA Astrophysics Data System (ADS)

Geary, Kevin

The development of high-frequency polymer electro-optic modulators has seen steady and significant progress in recent years, yet applications of these promising materials to more complicated integrated optic structures and arrays of devices have been limited primarily due to high optical waveguide loss characteristics. This is unfortunate since a major advantage of polymers as photonic materials is their compatibility with photolithographic processing of large components. In this Dissertation, etchless waveguide writing techniques are presented in order to improve the overall optical insertion loss of electro-optic polymer waveguide devices. These techniques include poling-induced writing, stress-induced waveguide writing, and photobleaching. Using these waveguide writing mechanisms, we have demonstrated straight waveguides, phase modulators, Mach-Zehnder intensity modulators, variable optical attenuators, and multimode interference (MMI) power splitters, all with improved loss characteristics over their etched rib waveguide counterparts. Ultimately, the insertion loss of an integrated optic device is limited by the actual material loss of the core waveguide material. In this Dissertation, passive-to-active polymer waveguide transitions are proposed to circumvent this problem. These transitions are compact, in-plane, self-aligned, and require no tapering of any physical dimensions of the waveguides. By utilizing both the time-dependent and intensity-dependent photobleaching characteristics of electro-optic polymer materials, adiabatic refractive index tapers can be seamlessly coupled to in-plane butt couple transitions, resulting in losses as low as 0.1 dB per interface. By integrating passive polymer planar lightwave circuits with the high-speed phase shifting capability of electro-optic polymers, active wideband photonic devices of increased size and complexity can be realized. Optical fiber-to-device coupling can also result in significant contributions to the overall insertion loss of an integrated electro-optic polymer device. In this Dissertation, we leverage the photobleached refractive index taper component of our proposed passive-to-active polymer waveguide transitions in order to realize a two-dimensional optical mode transformer for improved overall fiber-to-device coupling of electro-optic polymer waveguide devices.

Analysis and design of tunable wideband microwave photonics phase shifter based on Fabry-Perot cavity and Bragg mirrors in silicon-on-insulator waveguide.

PubMed

Qu, Pengfei; Zhou, Jingran; Chen, Weiyou; Li, Fumin; Li, Haibin; Liu, Caixia; Ruan, Shengping; Dong, Wei

2010-04-20

We designed a microwave (MW) photonics phase shifter, consisting of a Fabry-Perot filter, a phase modulation region (PMR), and distributed Bragg reflectors, in a silicon-on-insulator rib waveguide. The thermo-optics effect was employed to tune the PMR. It was theoretically demonstrated that the linear MW phase shift of 0-2pi could be achieved by a refractive index variation of 0-9.68x10(-3) in an ultrawideband (about 38?GHz-1.9?THz), and the corresponding tuning resolution was about 6.92 degrees / degrees C. The device had a very compact size. It could be easily integrated in silicon optoelectronic chips and expected to be widely used in the high-frequency MW photonics field.

Tunable Transmission and Deterministic Interface states in Double-zero-index Acoustic Metamaterials.

PubMed

Zhao, Wei; Yang, Yuting; Tao, Zhi; Hang, Zhi Hong

2018-04-20

Following the seminal work by Dubois et al. (Nat. Commun. 8, 14871 (2017)), we study a double-zero-index acoustic metamaterial with triangular lattice. By varying the height and diameter of air scatterers inside a parallel-plate acoustic waveguide, acoustic dispersion of the first-order waveguide mode can be manipulated and various interesting properties are explored. With accidental degeneracy of monopolar and dipolar modes, we numerically prove the double-zero-index properties of this novel acoustic metamaterial. Acoustic waveguides with tunable and asymmetric transmission are realized with this double-zero-index acoustic metamaterial embedded. Band inversion occurs if the bulk acoustic band diagram of this acoustic metamaterial is tuned. Deterministic interface states are found to exist on the interface between two acoustic metamaterials with inverted band diagrams.

Propagation characteristics of some novel coplanar waveguide transmission lines on GaAs at MM-wave frequencies

NASA Technical Reports Server (NTRS)

Simons, Rainee N.

1986-01-01

Three new Coplanar Waveguide (CPW) transmission lines, namely, Suspended CPW (SCPW), Stripline-like Suspended CPW (SSCPW) and Inverted CPW (ICPW), are proposed and also analyzed for their propagation characteristics. The substrate thickness, permittivity and dimensions of housing are assumed to be arbitrary. These structures have the following advantages over conventional CPW. Firstly, the ratio of guide wavelength to free space wavelength is closer to unity which results in larger dimensions and hence lower tolerances. Secondly, the effective dielectric constant is lower and hence the electromagnetic field energies are concentrated more in the air regions which should reduce attenuation. Thirdly, for a prescribed impedance level, the above structures have a wider slot width for identical strip width. Thus, low impedance lines can be achieved with reasonable slot dimensions. Fourthly, in an inverted CPW shunt mounting of active devices, such as Gunn and IMPATT diodes, between the strip and the metal trough is possible. This feature further enhances the attractiveness of the above structures. Lastly, an E-plane probe type transition from a rectangular waveguide to suspended CPW can also be easily realized. The computed results for GaAs at Ka-band illustrate the variation of normalized guide wavelength, effective dielectric constant and the characteristic impedance as a function of the: (1) frequency; (2) distance of separation between the trough side walls; (3) normalized strip and slot widths; and (4) normalized air gap.

Raman gain and nonlinear optical absorption measurements in a low-loss silicon waveguide

NASA Astrophysics Data System (ADS)

Rong, Haisheng; Liu, Ansheng; Nicolaescu, Remus; Paniccia, Mario; Cohen, Oded; Hak, Dani

2004-09-01

We fabricated a low-loss (˜0.22dB/cm) rib waveguide (WG) in silicon-on-insulator with a small effective core area of ˜1.57μm2 and measured the stimulated Raman scattering gain in the WG. We obtained 2.3dB Raman gain in a 4.8-cm-long S-shaped WG using a 1455nm pump laser with a cw power of 0.9W measured before the WG. In addition, we observed nonlinear dependence of Raman gain and optical propagation loss as a function of the pump power. Our study shows that this mainly is due to two-photon absorption (TPA) induced free carrier absorption in the silicon WG. We experimentally determined the TPA induced free carrier lifetime of 25ns, which agrees well with our modeling.

Experimental investigation of heat transfer and flow using V and broken V ribs within gas turbine blade cooling passage

NASA Astrophysics Data System (ADS)

Kumar, Sourabh; Amano, R. S.

2015-05-01

Gas turbines are extensively used for aircraft propulsion, land-based power generation, and various industrial applications. With an increase in turbine rotor inlet temperatures, developments in innovative gas turbine cooling technology enhance the efficiency and power output; these advancements of turbine cooling have allowed engine designs to exceed normal material temperature limits. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream of gas are based on an increase in the heat transfer areas and on the promotion of turbulence of the cooling flow. In this study, an improvement in performance is obtained by casting repeated continuous V- and broken V-shaped ribs on one side of the two pass square channels into the core of the blade. A detailed experimental investigation is done for two pass square channels with a 180° turn. Detailed heat transfer distribution occurring in the ribbed passage is reported for a steady state experiment. Four different combinations of 60° V- and broken 60° V-ribs in a channel are considered. A series of thermocouples are used to obtain the temperature on the channel surface and local heat transfer coefficients are obtained for Reynolds numbers 16,000, 56,000 and 85,000 within the turbulent flow regime. Area averaged data are calculated in order to compare the overall performance of the tested ribbed surface and to evaluate the degree of heat transfer enhancement induced by the rib. Flow within the channels is characterized by heat transfer enhancing ribs, bends, rotation and buoyancy effects. A series of experimental measurements is performed to predict the overall performance of the channel. This paper presents an attempt to collect information about the Nusselt number, the pressure drop and the overall performance of the eight different ribbed ducts at the specified Reynolds number. The main contribution of this study is to evaluate the best combination of rib arrangements throughout the two pass cooling channels. After a series of experiments, it can be concluded that the distribution of peaks in heat transfer in the case of inlet V and outlet inverted V is high. The overall performances for broken ribs are higher compared with the continuous ribs in two-pass cooling channels.

Optical data latch

DOEpatents

Vawter, G Allen [Corrales, NM

2010-08-31

An optical data latch is formed on a substrate from a pair of optical logic gates in a cross-coupled arrangement in which optical waveguides are used to couple an output of each gate to an photodetector input of the other gate. This provides an optical bi-stability which can be used to store a bit of optical information in the latch. Each optical logic gate, which can be an optical NOT gate (i.e. an optical inverter) or an optical NOR gate, includes a waveguide photodetector electrically connected in series with a waveguide electroabsorption modulator. The optical data latch can be formed on a III-V compound semiconductor substrate (e.g. an InP or GaAs substrate) from III-V compound semiconductor layers. A number of optical data latches can be cascaded to form a clocked optical data shift register.

Integrated Optical Synthetic Aperture Radar Processor.

DTIC Science & Technology

1987-09-01

acoustooptic cell was employed to input each radar return into a time-and-space integrating optical architecture comprised of several lenses, a CCD area array...acoustooptic cell and parallel rib waveguide structure. During the course of the literature survey, we became aware of an elegant and poten- tially profound...wave.) scatterer at (f , A(t) is the far-field pattern of the antenna. From the geometry of Si. 1. R can be written as [I-2R,/c - nT1 r(t) = A(nT) rectj

Efficient Color-Stable Inverted White Organic Light-Emitting Diodes with Outcoupling-Enhanced ZnO Layer.

PubMed

Zhao, Xin-Dong; Li, Yan-Qing; Xiang, Heng-Yang; Zhang, Yi-Bo; Chen, Jing-De; Xu, Lu-Hai; Tang, Jian-Xin

2017-01-25

Inverted organic light-emitting diode (OLED) has attracted extensive attention due to the demand in active-matrix OLED display panels as its geometry enables the direct connection with n-channel transistor backplane on the substrate. One key challenge of high-performance inverted OLED is an efficient electron-injection layer with superior electrical and optical properties to match the indium tin oxide cathode on substrate. We here propose a synergistic electron-injection architecture using surface modification of ZnO layer to simultaneously promote electron injection into organic emitter and enhance out-coupling of waveguided light. An efficient inverted white OLED is realized by introducing the nanoimprinted aperiodic nanostructure of ZnO for broadband and angle-independent light out-coupling and inserting an n-type doped interlayer for energy level tuning and injection barrier lowering. As a result, the optimized inverted white OLEDs have an external quantum efficiency of 42.4% and a power efficiency of 85.4 lm W 1- , which are accompanied by the superiority of angular color stability over the visible wavelength range. Our results may inspire a promising approach to fabricate high-efficiency inverted OLEDs for large-scale display panels.

Integrated optical silicon IC compatible nanodevices for biosensing applications

NASA Astrophysics Data System (ADS)

Lechuga, Laura M.; Sepulveda, Borja; Llobera, Andreu; Calle, Ana; Dominguez, Carlos M.

2003-04-01

Biological and chemical sensing is one of the application fields where integrated optical nanodevices can play an important role [1]. We present a Silicon Integrated Mach-Zehnder Interferometer Nanodevice using a Total Internal Refraction waveguide configuration. The induced changes due to a biomolecular interactions in the effective refractive index of the waveguide,is monitored by the measurement of the change in the properties of the propagating light. For using this device as a biosensor, the waveguides of the structure must verify two conditions: work in the monomode regime and to have a Surface Sensivity as high as possible in the sensing arm. The MZI device structure is: (i) a Si wafer with a 500 mm thickness (ii) a 2 mm thick thermal Silicon-Oxide layer with a refractive index of 1.46 (iii) a LPCVD Silicon Nitride layer of 100 nm thickness and a refractive index of 2.00, which is used as the guiding layer. To achieve monomode behavior is needed to define a rib structure, with a depth of only 3 nm, on the Silicon Nitride layer by a lithographic step. This rib structure is performed by RIE and is the most critical step in the microfabrication of the device. Over the structure a protective layer of LPCVD SiO2 is deposited, with a 2 mm thickness and a refractive index of 1.46, which is patterned (photolithography) and etched (RIE) to define the sensing arm. The high sensivity of these devices makes them quite suitable for biosensing applications. For that, without loosing their activity the receptors biomolecules are covanlently immobilized, at nanometer scale , on the sensor area surface. Biospecific molecular recognition takes places when the complementary analyte to the receptor is flowed over the receptor using a flow system. Several biosensing applications have been performed with this device as enviromental pollutant control, immunosensing or genetic detection.

Heterogeneous microring and Mach-Zehnder modulators based on lithium niobate and chalcogenide glasses on silicon

DOE PAGES

Rao, Ashutosh; Patil, Aniket; Chiles, Jeff; ...

2015-08-20

In this study, thin films of lithium niobate are wafer bonded onto silicon substrates and rib-loaded with a chalcogenide glass, Ge 23Sb 7S 70, to demonstrate strongly confined single-mode submicron waveguides, microring modulators, and Mach-Zehnder modulators in the telecom C band. The 200 μm radii microring modulators present 1.2 dB/cm waveguide propagation loss, 1.2 × 10 5 quality factor, 0.4 GHz/V tuning rate, and 13 dB extinction ratio. The 6 mm long Mach-Zehnder modulators have a half-wave voltage-length product of 3.8 V.cm and an extinction ratio of 15 dB. The demonstrated work is a key step towards enabling wafer scalemore » dense on-chip integration of high performance lithium niobate electro-optical devices on silicon for short reach optical interconnects and higher order advanced modulation schemes.« less

Heterogeneous microring and Mach-Zehnder modulators based on lithium niobate and chalcogenide glasses on silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, Ashutosh; Patil, Aniket; Chiles, Jeff

In this study, thin films of lithium niobate are wafer bonded onto silicon substrates and rib-loaded with a chalcogenide glass, Ge 23Sb 7S 70, to demonstrate strongly confined single-mode submicron waveguides, microring modulators, and Mach-Zehnder modulators in the telecom C band. The 200 μm radii microring modulators present 1.2 dB/cm waveguide propagation loss, 1.2 × 10 5 quality factor, 0.4 GHz/V tuning rate, and 13 dB extinction ratio. The 6 mm long Mach-Zehnder modulators have a half-wave voltage-length product of 3.8 V.cm and an extinction ratio of 15 dB. The demonstrated work is a key step towards enabling wafer scalemore » dense on-chip integration of high performance lithium niobate electro-optical devices on silicon for short reach optical interconnects and higher order advanced modulation schemes.« less

Launching of multi-project wafer runs in ePIXfab with micron-scale silicon rib waveguide technology

NASA Astrophysics Data System (ADS)

Aalto, Timo; Cherchi, Matteo; Harjanne, Mikko; Ylinen, Sami; Kapulainen, Markku; Vehmas, Tapani

2014-03-01

Silicon photonics is a rapidly growing R&D field where universities, institutes and companies are all involved and the business expectations for the next few years are high. One of the key enabling elements that led to the present success of silicon photonics is ePIXfab. It is a consortium of institutes that has together offered multi-project wafer (MPW) runs, packaging services, training, and feasibility studies. These services have significantly lowered the barrier of various research groups and companies to start developing silicon photonics. Until now the MPW services have been offered by the ePIXfab partners IMEC, CEA-Leti and IHP, which all use CMOS-type silicon photonics technology with a typical silicon-on-insulator (SOI) waveguide thickness of 220 nm. In November 2013 this MPW offering was expanded by the ePIXfab partner VTT that opened the access to its 3 μm SOI waveguide platform via ePIXfab MPW runs. This technology platform is complementary to the mainstream silicon photonics technology (220 nm) and it offers such benefits as very low losses, small polarization dependency, ultrabroadband operation and low starting costs

Measurement of locally resonant band gaps in a surface phononic crystal with inverted conical pillars

NASA Astrophysics Data System (ADS)

Hsu, Jin-Chen; Lin, Fan-Shun

2018-07-01

In this paper, we numerically and experimentally study locally resonant (LR) band gaps for surface acoustic waves (SAWs) in a honeycomb array of inverted conical pillars grown on the surface of a 128°YX lithium-niobate substrate. We show that the inverted conical pillars can be used to generate lower LR band gaps below the sound cone. This lowering effect is caused by the increase in the effective pillar mass without increasing the effective stiffness. We employ the finite-element method to calculate the LR band gaps and wideband slanted-finger interdigital transducers to measure the transmission of SAWs. Numerical results show that SAWs are prohibited from propagating through the structure in the lowered LR band gaps. Obvious LR band-gap lowering is observed in the experimental result of a surface phononic crystal with a honeycomb array of inverted conical pillars. The results enable enhanced control over the phononic metamaterial and surface structures, which may have applications in low-frequency waveguiding, acoustic isolation, acoustic absorbers, and acoustic filters.

Design of a wideband tunable AWG using electro-optic polymers and push-pull electrode configuration for ultrafast photonic switching applications

NASA Astrophysics Data System (ADS)

Asquini, Rita; d'Alessandro, Antonio; Salusti, Andrea; Gizzi, Claudio

2003-08-01

A tunable waveguide grating router (WGR) design is reported, where a subpicosecond phase shift is obtained by means of the electro-optically induced refractive index change in the arms of an arrayed-waveguide grating (AWG) made of highly nonlinear poled polymer CLD-75/APC. The polymer consists of a guest-host system, formed by a ring-locked phenyltetraene bridged cromophore dispersed in an amorphous polycarbonate, with coefficient r33=55pm/V and propagation losses of 1.7dB/cm. We propose a multilayer structure on Si substrate, where segments of each waveguide of the AWG are sandwiched between a ground gold electrode and electrodes whose length varies over the AWG. Numerical simulations of a device with electrode length difference of 250μm show a tuning range of 11nm centered at 1550nm by varying the applied voltage from -90V to +90V. From the optimized AWG, a WGR operating with 16 channels spaced by 100GHz has been designed. The WGR is made of single-mode rib waveguides and buffers whose thicknesses are respectively 1.8μm and 1.7μm. A broader tunability range is obtained using the push-pull technique, which induces a refractive index change of opposite sign in two halves of the AWG. A crosstalk of -40dB with tuning range of 22nm over the C-band was figured out.

Thin film lithium niobate electro-optic modulator with terahertz operating bandwidth.

PubMed

Mercante, Andrew J; Shi, Shouyuan; Yao, Peng; Xie, Linli; Weikle, Robert M; Prather, Dennis W

2018-05-28

We present a thin film crystal ion sliced (CIS) LiNbO 3 phase modulator that demonstrates an unprecedented measured electro-optic (EO) response up to 500 GHz. Shallow rib waveguides are utilized for guiding a single transverse electric (TE) optical mode, and Au coplanar waveguides (CPWs) support the modulating radio frequency (RF) mode. Precise index matching between the co-propagating RF and optical modes is responsible for the device's broadband response, which is estimated to extend even beyond 500 GHz. Matching the velocities of these co-propagating RF and optical modes is realized by cladding the modulator's interaction region in a thin UV15 polymer layer, which increases the RF modal index. The fabricated modulator possesses a tightly confined optical mode, which lends itself to a strong interaction between the modulating RF field and the guided optical carrier; resulting in a measured DC half-wave voltage of 3.8 V·cm -1 . The design, fabrication, and characterization of our broadband modulator is presented in this work.

A compressive-sensing Fourier-transform on-chip Raman spectrometer

NASA Astrophysics Data System (ADS)

Podmore, Hugh; Scott, Alan; Lee, Regina

2018-02-01

We demonstrate a novel compressive sensing Fourier-transform spectrometer (FTS) for snapshot Raman spectroscopy in a compact format. The on-chip FTS consists of a set of planar-waveguide Mach-Zehnder interferometers (MZIs) arrayed on a photonic chip, effecting a discrete Fourier-transform of the input spectrum. Incoherence between the sampling domain (time), and the spectral domain (frequency) permits compressive sensing retrieval using undersampled interferograms for sparse spectra such as Raman emission. In our fabricated device we retain our chosen bandwidth and resolution while reducing the number of MZIs, e.g. the size of the interferogram, to 1/4th critical sampling. This architecture simultaneously reduces chip footprint and concentrates the interferogram in fewer pixels to improve the signal to noise ratio. Our device collects interferogram samples simultaneously, therefore a time-gated detector may be used to separate Raman peaks from sample fluorescence. A challenge for FTS waveguide spectrometers is to achieve multi-aperture high throughput broadband coupling to a large number of single-mode waveguides. A multi-aperture design allows one to increase the bandwidth and spectral resolution without sacrificing optical throughput. In this device, multi-aperture coupling is achieved using an array of microlenses bonded to the surface of the chip, and aligned with a grid of vertically illuminated waveguide apertures. The microlens array accepts a collimated beam with near 100% fill-factor, and the resulting spherical wavefronts are coupled into the single-mode waveguides using 45& mirrors etched into the waveguide layer via focused ion-beam (FIB). The interferogram from the waveguide outputs is imaged using a CCD, and inverted via l1-norm minimization to correctly retrieve a sparse input spectrum.

Terahertz-wave surface-emitted difference-frequency generation without quasi-phase-matching technique.

PubMed

Avetisyan, Yuri H

2010-08-01

A scheme of terahertz (THz)-wave surface-emitted difference-frequency generation (SEDFG), which lacks the drawbacks associated with the usage of periodically orientation-inverted structures, is proposed. It is shown that both material birefringence of the bulk LiNbO(3) crystal and modal birefringence of GaAs/AlAs waveguide are sufficient to obtain SEDFG up to a frequency of approximately 3THz. The simplicity of the proposed scheme, along with the fact that there is a much smaller THz-wave decay in nonlinear crystal, makes it a good candidate for the practical realization of efficient THz generation. The use of a GaAs waveguide with an oxidized AlAs layer is proposed for enhanced THz-wave SEDFG in the vicinity of the GaAs polariton resonance at 8THz.

Clutter suppression and classification using twin inverted pulse sonar in ship wakes.

PubMed

Leighton, T G; Finfer, D C; Chua, G H; White, P R; Dix, J K

2011-11-01

Twin inverted pulse sonar (TWIPS) is here deployed in the wake of a moored rigid inflatable boat (RIB) with propeller turning, and then in the wake of a moving tanker of 4580 dry weight tonnage (the Whitchallenger). This is done first to test its ability to distinguish between scatter from the wake and scatter from the seabed, and second to test its ability to improve detectability of the seabed through the wake, compared to conventional sonar processing techniques. TWIPS does this by distinguishing between linear and nonlinear scatterers and has the further property of distinguishing those nonlinear targets which scatter energy at the even-powered harmonics from those which scatter in the odd-powered harmonics. TWIPS can also, in some manifestations, require no range correction (and therefore does not require the a priori environment knowledge necessary for most remote detection technologies).

Novel spot size converter for coupling standard single mode fibers to SOI waveguides

NASA Astrophysics Data System (ADS)

Sisto, Marco Michele; Fisette, Bruno; Paultre, Jacques-Edmond; Paquet, Alex; Desroches, Yan

2016-03-01

We have designed and numerically simulated a novel spot size converter for coupling standard single mode fibers with 10.4μm mode field diameter to 500nm × 220nm SOI waveguides. Simulations based on the eigenmode expansion method show a coupling loss of 0.4dB at 1550nm for the TE mode at perfect alignment. The alignment tolerance on the plane normal to the fiber axis is evaluated at +/-2.2μm for <=1dB excess loss, which is comparable to the alignment tolerance between two butt-coupled standard single mode fibers. The converter is based on a cross-like arrangement of SiOxNy waveguides immersed in a 12μm-thick SiO2 cladding region deposited on top of the SOI chip. The waveguides are designed to collectively support a single degenerate mode for TE and TM polarizations. This guided mode features a large overlap to the LP01 mode of standard telecom fibers. Along the spot size converter length (450μm), the mode is first gradually confined in a single SiOxNy waveguide by tapering its width. Then, the mode is adiabatically coupled to a SOI waveguide underneath the structure through a SOI inverted taper. The shapes of SiOxNy and SOI tapers are optimized to minimize coupling loss and structure length, and to ensure adiabatic mode evolution along the structure, thus improving the design robustness to fabrication process errors. A tolerance analysis based on conservative microfabrication capabilities suggests that coupling loss penalty from fabrication errors can be maintained below 0.3dB. The proposed spot size converter is fully compliant to industry standard microfabrication processes available at INO.

Investigation of AWG demultiplexer based SOI for CWDM application

NASA Astrophysics Data System (ADS)

Juhari, Nurjuliana; Susthitha Menon, P.; Shaari, Sahbudin; Annuar Ehsan, Abang

2017-11-01

9-channel Arrayed Waveguide Grating (AWG) demultiplexer for conventional and tapered structure were simulated using beam propagation method (BPM) with channel spacing of 20 nm. The AWG demultiplexer was design using high refractive index (n 3.47) material namely silicon-on-insulator (SOI) with rib waveguide structure. The characteristics of insertion loss, adjacent crosstalk and output spectrum response at central wavelength of 1.55 μm for both designs were compared and analyzed. The conventional AWG produced a minimum insertion loss of 6.64 dB whereas the tapered AWG design reduced the insertion loss by 2.66 dB. The lowest adjacent crosstalk value of -16.96 dB was obtained in the conventional AWG design and this was much smaller compared to the tapered AWG design where the lowest crosstalk value is -17.23 dB. Hence, a tapered AWG design significantly reduces the insertion loss but has a slightly higher adjacent crosstalk compared to the conventional AWG design. On the other hand, the output spectrum responses that are obtained from both designs were close to the Coarse Wavelength Division Multiplexing (CWDM) wavelength grid.

A proposal for digital electro-optic switches with free-carrier dispersion effect and Goos-Hanchen shift in silicon-on-insulator waveguide corner mirror

NASA Astrophysics Data System (ADS)

Sun, DeGui

2013-09-01

In a silicon-on-insulator (SOI) waveguide corner mirror (WCM) structure, with the quantum process of a frustrated total internal reflection (FTIR) phenomenon and the time delay principle in the two-dimensional potential barrier tunneling process of a mass of particles, we derive an accurate physical model for the Goos-Hanchen (GH) shift of optical guided-mode in the FTIR process, and in principle match the GH shift jumping states with the independent guided-modes. Then, we propose and demonstrate a new regime of 1 × N digital optical switches with a matching state between the free-carrier dispersion (FCD) based refractive index modulation (RIM) of silicon to create a GH shift jumping function of a photonic signal at the reflecting interface and the independent guided-modes in the FTIR process, where a MOS-capacitor type electro-optic modulation regime is proposed and discussed to realize an effective FCD-based RIM. At the critical matching state, i.e., the incident of an optical beam is at the vicinity of Brewster angle in the WCM, a mini-change of refractive index of waveguide material can cause a great jump of GH shift along the FTIR reflecting interface, and further a 1 × N digital optical switching process could be realized. For a 350-500 nm single-mode rib waveguide made on the 220 nm CMOS-compatible SOI substrate and with the FCD effect based RIM of silicon crystal, a concentration variation of 1018-1019 cm-3 has caused a 0.5-2.5 μm GH shift of reflected beam, which is at 2-5 times of a mode-size and hence radically convinces an optical switching function with a 1 × 3-1 × 10 scale.

Flat-top MZI filters: a novel robust design based on MMI splitters

NASA Astrophysics Data System (ADS)

Cherchi, Matteo; Harjanne, Mikko; Ylinen, Sami; Kapulainen, Markku; Vehmas, Tapani; Aalto, Timo

2016-03-01

Multimode Interferometers (MMIs) are an attractive alternative to directional couplers, ensuring more relaxed tolerances to fabrication errors and broader operation bandwidth. The drawback is that only a limited discrete set of splitting ratios is achievable with MMIs of constant cross section. This issue clearly limits their use in flat-top interferometric filters, which design requires, in general, free choice of the splitting ratios. Here we show for the first time that it is possible to design 4-stage flat-top interferometers using only standard MMIs with 50:50 and 85:15 splitting ratios. The design approach is based on the representation of the system on the Bloch sphere. Flat-top interleavers with different free spectral ranges have been designed and fabricated on the silicon photonics platform of VTT, based on 3 μm thick rib and strip waveguides. Two different layouts have been explored: one where all components are collinear and a more compact one which elements have been folded in a spiral shape. All interleavers have been designed for TE polarization, and they work in a wavelength range comparable with the 100 nm bandwidth of the MMI splitters. Even though fabrication imperfections and non-ideal behaviour of both waveguide bends and MMIs led to reduced extinction compared to simulations, most devices show in-band extinction exceeding 15 dB. The in-band losses of the most central channels did not exceed 1.5 dB compared to the reference straight waveguide. The designed interleavers can be employed in cascaded configurations to achieve broadband and fabrication tolerant flat-top wavelength (de)multiplexers.

Resolving precipitation-induced water content profiles through inversion of dispersive GPR data

NASA Astrophysics Data System (ADS)

Mangel, A. R.; Moysey, S. M.; Van Der Kruk, J.

2015-12-01

Ground-penetrating radar (GPR) has become a popular tool for monitoring hydrologic processes. When monitoring infiltration, the thin wetted zone that occurs near the ground surface at early times may act as a dispersive waveguide. This low-velocity layer traps the GPR waves, causing specific frequencies of the signal to travel at different phase velocities, confounding standard traveltime analysis. In a previous numerical study we demonstrated the potential of dispersion analysis for estimating the depth distribution of waveguide water contents. Here, we evaluate the effectiveness of the methodology when applying it to experimental time-lapse dispersive GPR data collected during a laboratory infiltration experiment in a relatively homogenous soil. A large sand-filled tank is equipped with an automated gantry to independently control the position of 1000 MHz source and receiver antennas. The system was programmed to repeatedly collect a common mid-point (CMP) profile at the center of the tank followed by two constant offset profiles (COP) in the x and y direction. Each collection was completed in 30 s and repeated 50 times during a 28 min experiment. Two minutes after the start of measurements, the surface of the sand was irrigated at a constant flux rate of 0.006 cm/sec for 23 minutes. Time-lapse COPs show increases in traveltime to reflectors in the tank associated with increasing water content, as well as the development of a wetting front reflection. From 4-10 min, the CMPs show a distinct shingling characteristic that is indicative of waveguide dispersion. Forward models where the waveguide is conceptualized as discrete layers and a piece-wise linear function were used to invert picked dispersion curves for waveguide properties. We show the results from both inversion approaches for multiple dispersive CMPs and show how the single layer model fails to represent the gradational nature of the wetting front.

Controlling plasma distributions as driving forces for ion migration during fs laser writing

NASA Astrophysics Data System (ADS)

Teddy Fernandez, Toney; Siegel, Jan; Hoyo, Jesus; Sotillo, Belen; Fernandez, Paloma; Solis, Javier

2015-04-01

The properties of structures written inside dielectrics with high repetition rate femtosecond lasers are known to depend strongly on the complex interplay of a large number of writing parameters. Recently, ion migration within the laser-excited volume has been identified as a powerful mechanism for changing the local element distribution and producing efficient optical waveguides. In this work it is shown that the transient plasma distribution induced during laser irradiation is a reliable monitor for predicting the final refractive index distribution of the waveguide caused by ion migration. By performing in situ plasma emission microscopy during the writing process inside a La-phosphate glass it is found that the long axis of the plasma distribution determines the axis of ion migration, being responsible for the local refractive index increase. This observation is also valid when strong positive or negative spherical aberration is induced, greatly deforming the focal volume and inverting the index profile. Even subtle changes in the writing conditions, such as an inversion of the writing direction (quill writing effect), show up in the form of a modified plasma distribution, which manifests as a modified index distribution. Finally, it is shown that the superior control over the waveguide properties employing the slit shaping technique is caused by the more confined plasma distribution produced. The underlying reasons for this unexpected result are discussed in terms of non-linear propagation and heat accumulation.

Polymer thermal optical switch for a flexible photonic circuit.

PubMed

Sun, Yue; Cao, Yue; Wang, Qi; Yi, Yunji; Sun, Xiaoqiang; Wu, Yuanda; Wang, Fei; Zhang, Daming

2018-01-01

Flexible and wearable optoelectronic devices are the new trend for an active lifestyle. These devices are polymer-based for flexibility. We demonstrated flexible polymer waveguide optical switches for a flexible photonic integrated circuit. The optical switches are composed of a single-mode inverted waveguide with dimensions of 5 μm waveguide width, 3 μm ridge height, and 3 μm slab height. A Mach-Zehnder structure was used in the device, with the Y-branch horizontal length of 0.1 cm, the distance between two heating branches of 30 μm, and the heating branch length of 1 cm. The optical field of the device was simulated by beam propagation to optimize the electrode position. The switching properties of the flexible optical switch with different working conditions, such as contact to the polymer, silicon, and skin, were simulated. The device was prepared based on the photo curved polymer and lithography method. The end faces of the flexible film device were processed using an excimer laser with optimized parameters of 28  mJ/cm 2 and 15 Hz. The response rise time and fall time on the PMMA substrate were measured as 1.98 ms and 2.71 ms, respectively. The power consumption was 16 mW and the extinction ratio was 11 dB. The response rise and fall times on the Si substrate were measured as 1.08 ms and 1.62 ms, respectively. The power consumption was 17 mW and the extinction ratio was 11 dB. The demonstrated properties indicate that this flexible optical waveguide structure can be used in the light control area of a wearable device.

Processing soft materials for integrated photonic and macroelectronic components and devices

NASA Astrophysics Data System (ADS)

Tsay, Candice Ruth

Incorporating soft materials into micro-fabrication processes opens up new functionalities for fabricated devices, but requires unique processing routes. This thesis presents our development of integrated photonic and macroelectronic structures through processing innovations that unite disparate inorganic/organic, and soft/rigid materials systems. For the integrated photonic system, we focus our efforts on chalcogenide glasses, dielectric materials that exhibit a variety of optical properties that make them desirable for near- and mid-infrared communications and sensing applications. However, processing limitations for these relatively fragile materials have made the direct integration of waveguides with sources or detectors challenging. Here we demonstrate the viability of several additive methods for patterning chalcogenide glass waveguides from solution. In particular, we focus on two complementary soft lithography methods. The first, micro-molding in capillaries (MIMIC), is shown to fabricate multi-mode As2S 3 waveguides which are directly integrated with quantum cascade lasers (QCLs). In a second method, we demonstrate the ability of micro-transfer molding (muTM), to produce arrays of single mode rib waveguides over large areas while maintaining low surface and edge roughness. These methods form a suite of processes that can be applied to chalcogenide solutions to create a diverse array of mid-IR photonic structures ranging from less than 5 to 10's of mum in cross-sectional dimension. Optical characterization, including measurement of waveguide loss by cut-back, is carried out in the mid-IR using QCLs. In addition, materials characterization of the chalcogenide glass structures is carried out to determine loss mechanisms and optimize processing. While we use soft polymeric materials as molds to pattern chalcogenide glasses, we also employ them as substrate material for stretchable electronic systems, which comprise a new class of flexible macroelectronics. These devices must undergo elastic deformation to large strain (>10%), for applications in which electronics are conformally shaped around surfaces of arbitrary shape, like many biological surfaces. We develop strategies for processing stretchable metallic electrodes and study the mechanism of their stretchability via careful observation of thin film micro-structures. Our macroelectronic work culminates in fabrication of stretchable microelectrode arrays that interface with brain tissue, laying the groundwork for future development of advanced bio-electronic interfaces.

Chondrosarcoma of the nasal septum.

PubMed

Magnano, Mauro; Boffano, Paolo; Machetta, Giacomo; Garibaldi, Elisabetta; Delmastro, Elena; Gabriele, Pietro

2015-03-01

Chondrosarcomas are non-epithelial malignant, slow growing tumors that usually involve pelvis, ribs, and long bones of extremities, scapula and sternum. Median age at diagnosis for head and neck chondrosarcomas is in the fourth decade. The etiopathogenesis of chondrosarcomas remains unknown. Treatment of choice is surgical, with adjuvant therapy having a limited role. In fact, radiation therapy and chemotherapy are reserved for residual or recurrent disease and palliation. As for surgery, several surgical procedures have been described. Recently, endoscopic surgery has allowed for the successful and less invasive treatment of inverting papillomas and even nasopharyngeal angiofibromas, lesions previously requiring extended external approaches. The aim of this paper was to present a case of nasal septal chondrosarcoma that was successfully treated with endoscopic surgery and radiation adjuvant therapy.

Development of sputtered techniques for thrust chambers, task 1. [evaluation of filler materials for regeneratively cooled thrust chambers

NASA Technical Reports Server (NTRS)

Mullaly, J. R.; Schmid, T. E.; Hecht, R. J.

1974-01-01

Filler materials proposed for use in the sputter fabrication regeneratively cooled thrust chambers were evaluated. Low melting castable alloys, CERROBEND. CERROCAST, and CERROTRU, slurry applied SERMETEL 481 and flame-sprayed aluminum were investigated as filler materials. Sputter deposition from a cylindrical cathode inverted magnestron was used to apply an OFHC copper closeout layer to filled OFHC copper ribbed-wall cylindrical substrates. The sputtered closeout layer structure was evaluated with respect to filler material contamination, predeposition machining and finishing operations, and deposition parameters. The application of aluminum by flame-spraying resulted in excessiver filler porosity. Though the outgassing from this porosity was found to be detrimental to the closeout layer structure, bond strengths in excess of 10,500 psi were achieved. Removal of the aluminum from the grooves was readily accomplished by leaching in a 7.0 molar solution of sodium hydroxide at 353 K. Of the other filler materials evaluated, CERROTRU was found to be the most suitable material with respect to completely filling the ribbed-wall cylinders and vacuum system compatibility. However, bond contamination resulted in low closeout layer bond strength with the CERROTRU filler. CERROBEND, CERROCAST, and SERMETEL 481 were found to be unacceptable as filler materials.

Design and characterization of integrated components for SiN photonic quantum circuits.

PubMed

Poot, Menno; Schuck, Carsten; Ma, Xiao-Song; Guo, Xiang; Tang, Hong X

2016-04-04

The design, fabrication, and detailed calibration of essential building blocks towards fully integrated linear-optics quantum computation are discussed. Photonic devices are made from silicon nitride rib waveguides, where measurements on ring resonators show small propagation losses. Directional couplers are designed to be insensitive to fabrication variations. Their offset and coupling lengths are measured, as well as the phase difference between the transmitted and reflected light. With careful calibrations, the insertion loss of the directional couplers is found to be small. Finally, an integrated controlled-NOT circuit is characterized by measuring the transmission through different combinations of inputs and outputs. The gate fidelity for the CNOT operation with this circuit is estimated to be 99.81% after post selection. This high fidelity is due to our robust design, good fabrication reproducibility, and extensive characterizations.

Low-loss adiabatically-tapered high-contrast gratings for slow-wave modulators on SOI

NASA Astrophysics Data System (ADS)

Sciancalepore, Corrado; Hassan, Karim; Ferrotti, Thomas; Harduin, Julie; Duprez, Hélène; Menezo, Sylvie; Ben Bakir, Badhise

2015-02-01

In this communication, we report about the design, fabrication, and testing of Silicon-based photonic integrated circuits (Si-PICs) including low-loss flat-band slow-light high-contrast-gratings (HCGs) waveguides at 1.31 μm. The light slowdown is achieved in 300-nm-thick silicon-on-insulator (SOI) rib waveguides by patterning adiabatically-tapered highcontrast gratings, capable of providing slow-light propagation with extremely low optical losses, back-scattering, and Fabry-Pérot noise. In detail, the one-dimensional (1-D) grating architecture is capable to provide band-edge group indices ng ~ 25, characterized by overall propagation losses equivalent to those of the index-like propagation regime (~ 1-2 dB/cm). Such photonic band-edge slow-light regime at low propagation losses is made possible by the adiabatic apodization of such 1-D HCGs, thus resulting in a win-win approach where light slow-down regime is reached without additional optical losses penalty. As well as that, a tailored apodization optimized via genetic algorithms allows the flattening of slow-light regime over the wavelength window of interest, therefore suiting well needs for group index stability for modulation purposes and non-linear effects generation. In conclusion, such architectures provide key features suitable for power-efficient high-speed modulators in silicon as well as an extremely low-loss building block for non-linear optics (NLO) which is now available in the Si photonics toolbox.

Industrial application of the decomposition of CO2 . NOx by large flow atmospheric microwave plasma LAMP employed in motorcar

NASA Astrophysics Data System (ADS)

Pandey, Anil; Niwa, Syunta; Morii, Yoshinari; Ikezawa, Shunjiro

2012-10-01

In order to decompose CO2 . NOx [1], we have developed the large flow atmospheric microwave plasma; LAMP [2]. It is very important to apply it for industrial innovation, so we have studied to apply the LAMP into motorcar. The characteristics of the developed LAMP are that the price is cheap and the decomposition efficiencies of CO2 . NOx are high. The mechanism was shown as the vertical configuration between the exhaust gas pipe and the waveguide was suitable [2]. The system was set up in the car body with a battery and an inverter. The battery is common between the engine and the inverter. In the application of motorcar, the flow is large, so the LAMP which has the merits of large flow, high efficient decomposition, and cheap apparatus will be superior.[4pt] [1] H. Barankova, L. Bardos, ISSP 2011, Kyoto.[0pt] [2] S. Ikezawa, S. Parajulee, S. Sharma, A. Pandey, ISSP 2011, Kyoto (2011) pp. 28-31; S. Ikezawa, S. Niwa, Y. Morii, JJAP meeting 2012, March 16, Waseda U. (2012).

Automatic three-dimensional rib centerline extraction from CT scans for enhanced visualization and anatomical context

NASA Astrophysics Data System (ADS)

Ramakrishnan, Sowmya; Alvino, Christopher; Grady, Leo; Kiraly, Atilla

2011-03-01

We present a complete automatic system to extract 3D centerlines of ribs from thoracic CT scans. Our rib centerline system determines the positional information for the rib cage consisting of extracted rib centerlines, spinal canal centerline, pairing and labeling of ribs. We show an application of this output to produce an enhanced visualization of the rib cage by the method of Kiraly et al., in which the ribs are digitally unfolded along their centerlines. The centerline extraction consists of three stages: (a) pre-trace processing for rib localization, (b) rib centerline tracing, and (c) post-trace processing to merge the rib traces. Then we classify ribs from non-ribs and determine anatomical rib labeling. Our novel centerline tracing technique uses the Random Walker algorithm to segment the structural boundary of the rib in successive 2D cross sections orthogonal to the longitudinal direction of the ribs. Then the rib centerline is progressively traced along the rib using a 3D Kalman filter. The rib centerline extraction framework was evaluated on 149 CT datasets with varying slice spacing, dose, and under a variety of reconstruction kernels. The results of the evaluation are presented. The extraction takes approximately 20 seconds on a modern radiology workstation and performs robustly even in the presence of partial volume effects or rib pathologies such as bone metastases or fractures, making the system suitable for assisting clinicians in expediting routine rib reading for oncology and trauma applications.

3-D characterization of high-permeability zones in a gravel aquifer using 2-D crosshole GPR full-waveform inversion and waveguide detection

NASA Astrophysics Data System (ADS)

Klotzsche, Anja; van der Kruk, Jan; Linde, Niklas; Doetsch, Joseph; Vereecken, Harry

2013-11-01

Reliable high-resolution 3-D characterization of aquifers helps to improve our understanding of flow and transport processes when small-scale structures have a strong influence. Crosshole ground penetrating radar (GPR) is a powerful tool for characterizing aquifers due to the method's high-resolution and sensitivity to porosity and soil water content. Recently, a novel GPR full-waveform inversion algorithm was introduced, which is here applied and used for 3-D characterization by inverting six crosshole GPR cross-sections collected between four wells arranged in a square configuration close to the Thur River in Switzerland. The inversion results in the saturated part of this gravel aquifer reveals a significant improvement in resolution for the dielectric permittivity and electrical conductivity images compared to ray-based methods. Consistent structures where acquisition planes intersect indicate the robustness of the inversion process. A decimetre-scale layer with high dielectric permittivity was revealed at a depth of 5-6 m in all six cross-sections analysed here, and a less prominent zone with high dielectric permittivity was found at a depth of 7.5-9 m. These high-permittivity layers act as low-velocity waveguides and they are interpreted as high-porosity layers and possible zones of preferential flow. Porosity estimates from the permittivity models agree well with estimates from Neutron-Neutron logging data at the intersecting diagonal planes. Moreover, estimates of hydraulic permeability based on flowmeter logs confirm the presence of zones of preferential flow in these depth intervals. A detailed analysis of the measured data for transmitters located within the waveguides, revealed increased trace energy due to late-arrival elongated wave trains, which were observed for receiver positions straddling this zone. For the same receiver positions within the waveguide, a distinct minimum in the trace energy was visible when the transmitter was located outside the waveguide. A novel amplitude analysis was proposed to explore these maxima and minima of the trace energy. Laterally continuous low-velocity waveguides and their boundaries were identified in the measured data alone. In contrast to the full-waveform inversion, this method follows a simple workflow and needs no detailed and time consuming processing or inversion of the data. Comparison with the full-waveform inversion results confirmed the presence of the waveguides illustrating that full-waveform inversion return reliable results at the highest resolution currently possible at these scales. We envision that full-waveform inversion of GPR data will play an important role in a wide range of geological, hydrological, glacial and periglacial studies in the critical zone.

Semitransparent inverted organic solar cell with improved absorption and reasonable transparency perception based on the nanopatterned MoO3/Ag/MoO3 anode

NASA Astrophysics Data System (ADS)

Tian, Ximin; Zhang, Ye; Hao, Yuying; Cui, Yanxia; Wang, Wenyan; Shi, Fang; Wang, Hua; Wei, Bin; Huang, Wei

2015-01-01

We demonstrate an inverted low bandgap semitransparent organic solar cell with improved absorption as well as reasonable transparency perception based on a nanopatterned MoO3/Ag/MoO3 (MAM) multilayer film as the transparent anode under illumination from the MAM side. The integrated absorption efficiency of the active layer at normal hybrid-polarized incidence considering an AM 1.5G solar spectrum is up to 51.69%, increased by 18.53% as compared to that of the equivalent planar device (43.61%) and reaching 77.3% of that of the corresponding opaque nanopatterned device (66.90%). Detailed investigations reveal that the excitation of plasmonic waveguide modes (at transverse magnetic polarization) and photonic modes (at transverse electric polarization) are responsible for the observed enhancement in absorption. Importantly, the proposed device exhibits an average transmittance of up to 28.4% and an average transparency perception of 26.3% for the human eyes under hybrid-polarized light illumination along with a good color rendering property. Additionally, our proposal works very well over a fairly wide angular range.

Babinet-Inverted Optical Yagi-Uda Antenna for Unidirectional Radiation to Free Space

NASA Astrophysics Data System (ADS)

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Choe, Jong-Ho; Lee, Jongcheon; Lee, Jaesoong; Jeong, Heejeong; Kim, Un Jeong; Park, Yeonsang; Song, In Yong; Park, Q.-Han; Hwang, Sung Woo; Kim, Kinam; Lee, Chang-Won

2014-06-01

Plasmonic nanoantennas are key elements in nanophotonics capable of directing radiation or enhancing the transition rate of a quantum emitter. Slot-type magnetic-dipole nanoantennas, which are complementary structures of typical electric-dipole-type antennas, have received little attention, leaving their antenna properties largely unexplored. Here we present a novel magnetic-dipole-fed multi-slot optical Yagi-Uda antenna. By engineering the relative phase of the interacting surface plasmon polaritons between the slot elements, we demonstrate that the optical antenna exhibits highly unidirectional radiation to free space. The unique features of the slot-based magnetic nanoantenna provide a new possibility of achieving integrated features such as energy transfer from one waveguide to another by working as a future optical via.

Cough-induced rib fractures.

PubMed

Hanak, Viktor; Hartman, Thomas E; Ryu, Jay H

2005-07-01

To define the demographic, clinical, and radiological features of patients with cough-induced rib fractures and to assess potential risk factors. For this retrospective, single-center study, we identified all cases of cough-induced rib fractures diagnosed at the Mayo Clinic in Rochester, Minn, over a 9-year period between January 1, 1996, and January 31, 2005. Bone densitometry data from patients' medical records were analyzed, and T scores were used to classify patients into bone density categories. The mean +/- SD age of the 54 study patients at presentation was 55+/-17 years, and 42 patients (78%) were female. Patients presented with chest wall pain after onset of cough. Rib fracture was associated with chronic cough (> or =3 weeks' duration) in 85% of patients. Rib fractures were documented by chest radiography, rib radiography, computed tomography, or bone scan. Chest radiography had been performed in 52 patients and revealed rib fracture in 30 (58%). There were 112 fractured ribs in 54 patients. One half of patients had more than one fractured rib. Right-sided rib fractures alone were present in 17 patients (26 fractured ribs), left-sided in 23 patients (35 fractured ribs), and bilateral in 14 patients (51 fractured ribs). The most commonly fractured rib on both sides was rib 6. The fractures were most common at the lateral aspect of the rib cage. Bone densitometry was done in 26 patients and revealed osteopenia or osteoporosis in 17 (65%). Cough-induced rib fractures occur primarily in women with chronic cough. Middle ribs along the lateral aspect of the rib cage are affected most commonly. Although reduced bone density is likely a risk factor, cough-induced rib fractures can occur in the presence of normal bone density.

Analysis of the current rib support practices and techniques in U.S. coal mines

PubMed Central

Mohamed, Khaled M.; Murphy, Michael M.; Lawson, Heather E.; Klemetti, Ted

2016-01-01

Design of rib support systems in U.S. coal mines is based primarily on local practices and experience. A better understanding of current rib support practices in U.S. coal mines is crucial for developing a sound engineering rib support design tool. The objective of this paper is to analyze the current practices of rib control in U.S. coal mines. Twenty underground coal mines were studied representing various coal basins, coal seams, geology, loading conditions, and rib control strategies. The key findings are: (1) any rib design guideline or tool should take into account external rib support as well as internal bolting; (2) rib bolts on their own cannot contain rib spall, especially in soft ribs subjected to significant load—external rib control devices such as mesh are required in such cases to contain rib sloughing; (3) the majority of the studied mines follow the overburden depth and entry height thresholds recommended by the Program Information Bulletin 11-29 issued by the Mine Safety and Health Administration; (4) potential rib instability occurred when certain geological features prevailed—these include draw slate and/or bone coal near the rib/roof line, claystone partings, and soft coal bench overlain by rock strata; (5) 47% of the studied rib spall was classified as blocky—this could indicate a high potential of rib hazards; and (6) rib injury rates of the studied mines for the last three years emphasize the need for more rib control management for mines operating at overburden depths between 152.4 m and 304.8 m. PMID:27648341

Rib fractures and their association With solid organ injury: higher rib fractures have greater significance for solid organ injury screening.

PubMed

Rostas, Jack W; Lively, Timothy B; Brevard, Sidney B; Simmons, Jon D; Frotan, Mohammad A; Gonzalez, Richard P

2017-04-01

The purpose of this study was to identify patients with rib injuries who were at risk for solid organ injury. A retrospective chart review was performed of all blunt trauma patients with rib fractures during the period from July 2007 to July 2012. Data were analyzed for association of rib fractures and solid organ injury. In all, 1,103 rib fracture patients were identified; 142 patients had liver injuries with 109 (77%) associated right rib fractures. Right-sided rib fractures with highest sensitivity for liver injury were middle rib segment (5 to 8) and lower segment (9 to 12) with liver injury sensitivities of 68% and 43%, respectively (P < .001); 151 patients had spleen injuries with 119 (79%) associated left rib fractures. Left middle segment rib fractures and lower segment rib fractures had sensitivities of 80% and 63% for splenic injury, respectively (P < .003). Rib fractures higher in the thoracic cage have significant association with solid organ injury. Using rib fractures from middle plus lower segments as indication for abdominal screening will significantly improve rib fracture sensitivity for identification of solid organ injury. Copyright © 2016 Elsevier Inc. All rights reserved.

"Buckle" rib fracture: an artifact following cardio-pulmonary resuscitation detected on postmortem CT.

PubMed

Yang, Kyung-Moo; Lynch, Matthew; O'Donnell, Chris

2011-09-01

Buckle rib fractures are incomplete fractures involving the inner cortex alone, and are rarely detected on routine chest X-ray or at autopsy. The characteristics of these fractures have not been well evaluated in situ although they are commonly observed on postmortem CT images especially following CPR. The postmortem CT findings in 42 cases showing buckle rib fractures caused by CPR were reviewed. The cause of death in all cases was non-traumatic. The shape, number, location, and distribution of these buckle rib fractures and their relationship to other types of rib fractures were evaluated using a novel oblique axial multiplanar reconstruction technique. Almost all incomplete rib fractures associated with CPR are buckle rib fractures (90.5%). All rib fractures were distributed from the second to ninth ribs with over 95% being within the second to seventh ribs. Buckle rib fractures are dominant in the seventh to ninth ribs and the proportion of buckle rib fractures located in the vicinity of the costochondral junctions increases with the lower ribs. Over 97% of all CPR associated rib fractures are located in the anterior one third of the ribs based on a new measurement method utilizing oblique axial multiplanar reconstruction of the CT data. When recognition of incomplete or buckle rib fractures on postmortem CT is taken into account, detection of symmetry and continuity of rib fractures typically associated with CPR is improved compared with the detection of complete fractures alone. Recognition of buckle rib fractures and their characteristics on postmortem CT is of benefit to the forensic pathologist in evaluating the possibility of CPR and the differentiation of resuscitative artifact from forensically significant visceral injury observed at autopsy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Development of a socket-type rib coaptation device made of poly-L-lactide fibers: feasibility study in a canine model

PubMed Central

Komatsu, Teruya; Sakaguchi, Yasuto; Muranishi, Yusuke; Yutaka, Yojiro; Date, Hiroshi; Nakamura, Tatsuo

2018-01-01

Background Costal coaptation pins made of poly-L-lactide (PLA) are clinically available for fixing surgically divided ribs. However, the clinical results of such rib fixation have not been completely satisfactory. We aimed to develop a new rib coaptation socket system and explore its clinical applicability. Methods We surgically divided three consecutive ribs of each beagle dog, and rib coaptation sockets were implanted to stabilize each rib. Fifteen 3-dimensional (3D)-printed and 30 PLA fiber knitted sockets were implanted in five and ten dogs, respectively, to stabilize the artificially divided ribs. Mechanical analysis of the sockets and radiographical examination of costal fixation were performed to evaluate the effectiveness of the newly developed socket system for rib stabilization. Results All 15 ribs with 3D-printed sockets had displaced 1 month after the operation. Three ribs in one dog with implanted PLA fiber knitted sockets were displaced radiographically after 1 month, and the grade of displacement remained unchanged after 6 months. The remaining 27 ribs fixed with PLA fiber knitted sockets did not show any displacement. Conclusions The PLA fiber knitted rib coaptation socket system was sufficiently durable for the stabilization of divided ribs with biocompatibility. This promising finding can be applied for clinical stabilization of divided ribs. PMID:29850125

Development of a socket-type rib coaptation device made of poly-L-lactide fibers: feasibility study in a canine model.

PubMed

Komatsu, Teruya; Sato, Toshihiko; Sakaguchi, Yasuto; Muranishi, Yusuke; Yutaka, Yojiro; Date, Hiroshi; Nakamura, Tatsuo

2018-04-01

Costal coaptation pins made of poly-L-lactide (PLA) are clinically available for fixing surgically divided ribs. However, the clinical results of such rib fixation have not been completely satisfactory. We aimed to develop a new rib coaptation socket system and explore its clinical applicability. We surgically divided three consecutive ribs of each beagle dog, and rib coaptation sockets were implanted to stabilize each rib. Fifteen 3-dimensional (3D)-printed and 30 PLA fiber knitted sockets were implanted in five and ten dogs, respectively, to stabilize the artificially divided ribs. Mechanical analysis of the sockets and radiographical examination of costal fixation were performed to evaluate the effectiveness of the newly developed socket system for rib stabilization. All 15 ribs with 3D-printed sockets had displaced 1 month after the operation. Three ribs in one dog with implanted PLA fiber knitted sockets were displaced radiographically after 1 month, and the grade of displacement remained unchanged after 6 months. The remaining 27 ribs fixed with PLA fiber knitted sockets did not show any displacement. The PLA fiber knitted rib coaptation socket system was sufficiently durable for the stabilization of divided ribs with biocompatibility. This promising finding can be applied for clinical stabilization of divided ribs.

Rib Radiography versus Chest Computed Tomography in the Diagnosis of Rib Fractures.

PubMed

Sano, Atsushi

2018-05-01

 The accurate diagnosis of rib fractures is important in chest trauma. Diagnostic images following chest trauma are usually obtained via chest X-ray, chest computed tomography, or rib radiography. This study evaluated the diagnostic characteristics of rib radiography and chest computed tomography.  Seventy-five rib fracture patients who underwent both chest computed tomography and rib radiography between April 2008 and December 2013 were included. Rib radiographs, centered on the site of pain, were taken from two directions. Chest computed tomography was performed using a 16-row multidetector scanner with 5-mm slice-pitch without overlap, and axial images were visualized in a bone window.  In total, 217 rib fractures were diagnosed in 75 patients. Rib radiography missed 43 rib fractures in 24 patients. The causes were overlap with organs in 15 cases, trivial fractures in 21 cases, and injury outside the imaging range in 7 cases. Left lower rib fractures were often missed due to overlap with the heart, while middle and lower rib fractures were frequently not diagnosed due to overlap with abdominal organs. Computed tomography missed 21 rib fractures in 17 patients. The causes were horizontal fractures in 10 cases, trivial fractures in 9 cases, and insufficient breath holding in 1 case.  In rib radiography, overlap with organs and fractures outside the imaging range were characteristic reasons for missed diagnoses. In chest computed tomography, horizontal rib fractures and insufficient breath holding were often responsible. We should take these challenges into account when diagnosing rib fractures. Georg Thieme Verlag KG Stuttgart · New York.

Anatomically contoured plates for fixation of rib fractures.

PubMed

Bottlang, Michael; Helzel, Inga; Long, William B; Madey, Steven

2010-03-01

: Intraoperative contouring of long bridging plates for stabilization of flail chest injuries is difficult and time consuming. This study implemented for the first time biometric parameters to derive anatomically contoured rib plates. These plates were tested on a range of cadaveric ribs to quantify plate fit and to extract a best-fit plating configuration. : Three left and three right rib plates were designed, which accounted for anatomic parameters required when conforming a plate to the rib surface. The length lP over which each plate could trace the rib surface was evaluated on 109 cadaveric ribs. For each rib level 3-9, the plate design with the highest lP value was extracted to determine a best-fit plating configuration. Furthermore, the characteristic twist of rib surfaces was measured on 49 ribs to determine the surface congruency of anatomic plates with a constant twist. : The tracing length lP of the best-fit plating configuration ranged from 12.5 cm to 14.7 cm for ribs 3-9. The corresponding range for standard plates was 7.1-13.7 cm. The average twist of ribs over 8-cm, 12-cm, and 16-cm segments was 8.3 degrees, 20.6 degrees, and 32.7 degrees, respectively. The constant twist of anatomic rib plates was not significantly different from the average rib twist. : A small set of anatomic rib plates can minimize the need for intraoperative plate contouring for fixation of ribs 3-9. Anatomic rib plates can therefore reduce the time and complexity of flail chest stabilization and facilitate spanning of flail segments with long plates.

Novel classification system of rib fractures observed in infants.

PubMed

Love, Jennifer C; Derrick, Sharon M; Wiersema, Jason M; Pinto, Deborrah C; Greeley, Christopher; Donaruma-Kwoh, Marcella; Bista, Bibek

2013-03-01

Rib fractures are considered highly suspicious for nonaccidental injury in the pediatric clinical literature; however, a rib fracture classification system has not been developed. As an aid and impetus for rib fracture research, we developed a concise schema for classifying rib fracture types and fracture location that is applicable to infants. The system defined four fracture types (sternal end, buckle, transverse, and oblique) and four regions of the rib (posterior, posterolateral, anterolateral, and anterior). It was applied to all rib fractures observed during 85 consecutive infant autopsies. Rib fractures were found in 24 (28%) of the cases. A total of 158 rib fractures were identified. The proposed schema was adequate to classify 153 (97%) of the observed fractures. The results indicate that the classification system is sufficiently robust to classify rib fractures typically observed in infants and should be used by researchers investigating infant rib fractures. © 2013 American Academy of Forensic Sciences.

Evaluating the point of separation, during carcass fabrication, between the beef wholesale rib and the beef wholesale chuck.

PubMed

Reuter, B J; Wulf, D M; Shanks, B C; Maddock, R J

2002-01-01

This study determined whether there is a logical point of value change, related to either tenderness or consumer acceptance, at which to separate the beef carcass within the rib/chuck region. Rib/chuck rolls (RCR); (n = 30) consisting of the ribeye roll and chuck eye roll subprimals (2nd through 12th rib locations) were cut into 22 steaks each (two steaks per rib location), and Warner-Bratzler shear force and consumer purchase preference were evaluated for steaks at each rib location. Steaks from different locations of the RCR were composed of differing proportions of several muscles: longissimus muscle (LM), spinalis dorsi and multifidus dorsi (SM), and complexus (CO). The LM (4th to 12th rib) contained three tenderness regions: 7th through 12th rib, 5th and 6th ribs, and 4th rib regions (lowest, intermediate, and highest shear force values, respectively; P < 0.01). Shear force differed (P < 0.05) among rib locations for the SM (2nd to 9th rib), but no logical pattern was evident. The CO (2nd to 7th rib) was more tender toward the anterior end (P < 0.05). The region of the RCR represented by the 4th through 6th rib locations had steaks with higher weighted-average shear force (average shear force of each steak, weighted for surface area of each muscle) values than the remainder of the RCR (P < 0.05). Animal-to-animal variation in shear force was 36% greater than rib-to-rib variation in shear force; thus, statistically significant differences in tenderness among rib locations may be undetectable by consumers. Steaks (n = 330) were offered for sale at a retail supermarket and case time was monitored on each steak to determine consumer purchase preference. Steaks from the 2nd through 4th rib locations required more time to sell (P < 0.01) than steaks from the 5th through 12th rib locations. Two alternative locations for the rib/chuck separation point could be between the 6th and 7th ribs, yielding a ribeye subprimal useful in marketing a "premium quality" product, or between the 4th and 5th ribs, which would yield four more 2.5-cm ribeye steaks per carcass.

Increasing number of fractured ribs is not predictive of the severity of splenic injury following blunt trauma: an analysis of a National Trauma Registry database.

PubMed

Boris, Kessel; Forat, Swaid; Itamar, Ashkenazi; Oded, Olsha; Kobi, Peleg; Adi, Givon; Igor, Jeroukhimov; Ricardo, Alfici

2014-05-01

Association between rib fractures and incidence of abdominal solid organs injury is well described. However, the correlation between the number of fractured ribs and severity of splenic injury is not clear. The purpose of this study was to assess whether an increasing number of rib fractures predicts the severity of splenic injury in blunt trauma patients. A retrospective cohort study involving blunt trauma patients with concomitant splenic injuries and rib fractures, between the years 1998 and 2012, registered in the Israeli National Trauma Registry. Of 321,618 patients with blunt mechanism of trauma, 57,130 had torso injuries, and of these 14,651 patients sustained rib fractures, and 3691 patients suffered from splenic injury. Concomitant splenic injury occurred in 1326 of the patients with rib fractures (9.1%), as compared to 2365 patients sustaining splenic injury without rib fractures (5.6%). The incidence of splenic injury among patients sustaining 5 or more rib fractures was significantly higher compared to patients suffering from 1 to 4 rib fractures. Among patients with splenic injury, the tendency to sustain associated rib fractures increased steadily with age. Patients with concomitant rib fractures had higher Injury Severity Score (ISS), but similar mortality rates, compared to patients with splenic injury without rib fractures. Among patients with concomitant rib fractures and splenic injury, there was no relation between the number of fractured ribs and the severity of splenic injury, neither as a whole group, nor after stratification according to the mechanism of injury. Although the presence of rib fractures increases the probability of splenic injury in blunt torso trauma, there is no relation between the number of fractured ribs and splenic injury severity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cavernous hemangioma of the rib: a rare diagnosis.

PubMed

Gourgiotis, Stavros; Piyis, Anastasios; Panagiotopoulos, Nikolaos; Panayotopoulos, Panayotis; Salemis, Nikolaos S

2010-01-01

Hemangioma of the rib is an uncommon benign vascular tumour. A case of rib hemangioma in a 29-year-old woman is presented. Chest roentgenogram and computed tomography revealed a mass along the inner surface of the 7th left rib with bone destruction. She underwent resection of the 7th rib. The pathologic diagnosis was cavernous hemangioma. Hemangiomas of the rib are rare tumours but should be kept in mind in the differential diagnosis of rib tumours.

A 3' UTR-derived non-coding RNA RibS increases expression of cfa and promotes biofilm formation of Salmonella enterica serovar Typhi.

PubMed

Zhao, Xin; Liu, Rui; Tang, Hao; Osei-Adjei, George; Xu, Shungao; Zhang, Ying; Huang, Xinxiang

2018-05-08

Bacterial non-coding RNAs (ncRNAs) are widely studied and found to play important roles in regulating various cellular processes. Recently, many ncRNAs have been discovered to be transcribed or processed from 3' untranslated regions (3' UTRs). Here we reported a novel 3' UTR-derived ncRNA, RibS, which could influence biofilm formation of Salmonella enterica serovar Typhi (S. Typhi). RibS was confirmed to be a ∼700 nt processed product produced by RNase III-catalyzed cleavage from the 3' UTR of riboflavin synthase subunit alpha mRNA, RibE. Overexpression of RibS increased the expression of the cyclopropane fatty acid synthase gene, cfa, which was located at the antisense strand. Biofilm formation of S. Typhi was enhanced by overexpressing RibS both in the wild type strain and cfa deletion mutant. Deletion of cfa attenuated biofilm formation of S. Typhi, while complementation of cfa partly restored the phenotype. Moreover, overexpressing cfa enhanced the biofilm formation of S. Typhi. In summary, RibS has been identified as a novel ncRNA derived from the 3' UTR of RibE that promotes biofilm formation of S. Typhi, and it appears to do so, at least in part, by increasing the expression of cfa. Copyright © 2018 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Local heat transfer distribution in a square channel with 90 continuous, 90 saw tooth profiled and 60 broken ribs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Abhishek; SriHarsha, V.; Prabhu, S.V.

2008-02-15

Internal channel cooling is employed in advanced gas turbines blade to allow high inlet temperatures so as to achieve high thrust/weight ratios and low specific fuel consumption. The objective of the present study is to measure the local heat transfer distributions in a double wall ribbed square channel with 90 continuous, 90 saw tooth profiled and 60 V-broken ribs. Comparison is made between the 90 continuous ribs (P/e = 7 and 10 for a e/D = 0.15) and 90 saw tooth profiled rib configurations (P/e = 7 for an e/D = 0.15) for the same rib height to the hydraulicmore » diameter ratio (e/D). The effect of pitch to rib height ratio (P/e = 7.5,10 and 12) of 60 V-broken ribbed channel with a constant rib height to hydraulic diameter ratio (e/D) of 0.0625 on the local heat transfer distribution is studied. The Reynolds number based on duct hydraulic diameter is ranging from 10,000 to 30,000. A thin stainless steel foil of 0.05 mm thickness is used as heater and infrared thermography technique is used to obtain the local temperature distribution on the surface. The images are captured in the periodically fully developed region of the channel. It is observed that the heat transfer augmentations in the channel with 90 saw tooth profiled ribs are comparable with those of 90 continuous ribs. The enhancements caused by 60 V-broken ribs are higher than those of 90 continuous ribs. The effect of pitch to the rib height ratio (P/e) is not significant for channel with 60 V-broken ribs for a given rib height to hydraulic diameter ratio (e/D = 0.0625). (author)« less

Cavernous Hemangioma of the Rib: A Rare Diagnosis

PubMed Central

Gourgiotis, Stavros; Piyis, Anastasios; Panagiotopoulos, Nikolaos; Panayotopoulos, Panayotis; Salemis, Nikolaos S.

2010-01-01

Hemangioma of the rib is an uncommon benign vascular tumour. A case of rib hemangioma in a 29-year-old woman is presented. Chest roentgenogram and computed tomography revealed a mass along the inner surface of the 7th left rib with bone destruction. She underwent resection of the 7th rib. The pathologic diagnosis was cavernous hemangioma. Hemangiomas of the rib are rare tumours but should be kept in mind in the differential diagnosis of rib tumours. PMID:20585365

[Internal fixation treatment of multiple rib fractures with absorbable rib-connecting-pins under epidural anesthesia].

PubMed

Liu, Jinliang; Li, Keyao; Ju, Zhenlong; Bai, Yan

2011-03-01

To study the indications, methods and experience of absorbable rib-connecting-pins fixation in the treatment of multiple rib fractures. 52 cases with multiple rib fractures were performed internal fixation with absorbable rib-connecting-pins under epidural anesthesia. All cases were followed up for 1 to 12 months, with an average of 5 months. All fractures were achieved healing in 3 to 6 months after the operation and were not found chest wall deformity. Absorbable rib-connecting-pins fixation is a simple and effective method and worthies recommending to perform operation for the appropriate cases with multiple rib fractures.

Cough-induced rib fractures.

PubMed

Sano, Atsushi; Tashiro, Ken; Fukuda, Tsutomu

2015-10-01

Occasionally, patients who complain of chest pain after the onset of coughing are diagnosed with rib fractures. We investigated the characteristics of cough-induced rib fractures. Between April 2008 and December 2013, 17 patients were referred to our hospital with chest pain after the onset of coughing. Rib radiography was performed, focusing on the location of the chest pain. When the patient had other signs and symptoms such as fever or persistent cough, computed tomography of the chest was carried out. We analyzed the data retrospectively. Rib fractures were found in 14 of the 17 patients. The age of the patients ranged from 14 to 86 years (median 39.5 years). Ten patients were female and 4 were male. Three patients had chronic lung disease. There was a single rib fracture in 9 patients, and 5 had two or more fractures. The middle and lower ribs were the most commonly involved; the 10th rib was fractured most frequently. Cough-induced rib fractures occur in every age group regardless of the presence or absence of underlying disease. Since rib fractures often occur in the lower and middle ribs, rib radiography is useful for diagnosis. © The Author(s) 2015.

Clinical and Radiologic Predictive Factors of Rib Fractures in Outpatients With Chest Pain.

PubMed

Zhang, Liang; McMahon, Colm J; Shah, Samir; Wu, Jim S; Eisenberg, Ronald L; Kung, Justin W

To identify the clinical and radiologic predictive factors of rib fractures in stable adult outpatients presenting with chest pain and to determine the utility of dedicated rib radiographs in this population of patients. Following Institutional Review Board approval, we performed a retrospective review of 339 consecutive cases in which a frontal chest radiograph and dedicated rib series had been obtained for chest pain in the outpatient setting. The frontal chest radiograph and dedicated rib series were sequentially reviewed in consensus by two fellowship-trained musculoskeletal radiologists blinded to the initial report. The consensus interpretation of the dedicated rib series was used as the gold standard. Multiple variable logistic regression analysis assessed clinical and radiological factors associated with rib fractures. Fisher exact test was used to assess differences in medical treatment between the 2 groups. Of the 339 patients, 53 (15.6%) had at least 1 rib fracture. Only 20 of the 53 (37.7%) patients' fractures could be identified on the frontal chest radiograph. The frontal chest radiograph had a sensitivity of 38% and specificity of 100% when using the rib series as the reference standard. No pneumothorax, new mediastinal widening or pulmonary contusion was identified. Multiple variable logistic regression analysis of clinical factors associated with the presence of rib fractures revealed a significant association of trauma history (odds ratio 5.7 [p < 0.05]) and age ≥40 (odds radio 3.1 [p < 0.05]). Multiple variable logistic regression analysis of radiographic factors associated with rib fractures in this population demonstrated a significant association of pleural effusion with rib fractures (odds ratio 18.9 [p < 0.05]). Patients with rib fractures received narcotic analgesia in 47.2% of the cases, significantly more than those without rib fractures (21.3%, p < 0.05). None of the patients required hospitalization. In the stable outpatient setting, rib fractures have a higher association with a history of minor trauma and age ≥40 in the adult population. Radiographic findings associated with rib fractures include pleural effusion. The frontal chest radiograph alone has low sensitivity in detecting rib fractures. The dedicated rib series detected a greater number of rib fractures. Although no patients required hospitalization, those with rib fractures were more likely to receive narcotic analgesia. Copyright © 2018 Elsevier Inc. All rights reserved.

Numerical investigations of rib fracture failure models in different dynamic loading conditions.

PubMed

Wang, Fang; Yang, Jikuang; Miller, Karol; Li, Guibing; Joldes, Grand R; Doyle, Barry; Wittek, Adam

2016-01-01

Rib fracture is one of the most common thoracic injuries in vehicle traffic accidents that can result in fatalities associated with seriously injured internal organs. A failure model is critical when modelling rib fracture to predict such injuries. Different rib failure models have been proposed in prediction of thorax injuries. However, the biofidelity of the fracture failure models when varying the loading conditions and the effects of a rib fracture failure model on prediction of thoracic injuries have been studied only to a limited extent. Therefore, this study aimed to investigate the effects of three rib failure models on prediction of thoracic injuries using a previously validated finite element model of the human thorax. The performance and biofidelity of each rib failure model were first evaluated by modelling rib responses to different loading conditions in two experimental configurations: (1) the three-point bending on the specimen taken from rib and (2) the anterior-posterior dynamic loading to an entire bony part of the rib. Furthermore, the simulation of the rib failure behaviour in the frontal impact to an entire thorax was conducted at varying velocities and the effects of the failure models were analysed with respect to the severity of rib cage damages. Simulation results demonstrated that the responses of the thorax model are similar to the general trends of the rib fracture responses reported in the experimental literature. However, they also indicated that the accuracy of the rib fracture prediction using a given failure model varies for different loading conditions.

Triode carbon nanotube field emission display using barrier rib structure and manufacturing method thereof

DOEpatents

Han, In-taek; Kim, Jong-min

2003-01-01

A triode carbon nanotube field emission display (FED) using a barrier rib structure and a manufacturing method thereof are provided. In a triode carbon nanotube FED employing barrier ribs, barrier ribs are formed on cathode lines by a screen printing method, a mesh structure is mounted on the barrier ribs, and a spacer is inserted between the barrier ribs through slots of the mesh structure, thereby stably fixing the mesh structure and the spacer within a FED panel due to support by the barrier ribs.

Deeply etched MMI-based components on 4 μm thick SOI for SOA-based optical RAM cell circuits

NASA Astrophysics Data System (ADS)

Cherchi, Matteo; Ylinen, Sami; Harjanne, Mikko; Kapulainen, Markku; Aalto, Timo; Kanellos, George T.; Fitsios, Dimitrios; Pleros, Nikos

2013-02-01

We present novel deeply etched functional components, fabricated by multi-step patterning in the frame of our 4 μm thick Silicon on Insulator (SOI) platform based on singlemode rib-waveguides and on the previously developed rib-tostrip converter. These novel components include Multi-Mode Interference (MMI) splitters with any desired splitting ratio, wavelength sensitive 50/50 splitters with pre-filtering capability, multi-stage Mach-Zehnder Interferometer (MZI) filters for suppression of Amplified Spontaneous Emission (ASE), and MMI resonator filters. These novel building blocks enable functionalities otherwise not achievable on our SOI platform, and make it possible to integrate optical RAM cell layouts, by resorting to our technology for hybrid integration of Semiconductor Optical Amplifiers (SOAs). Typical SOA-based RAM cell layouts require generic splitting ratios, which are not readily achievable by a single MMI splitter. We present here a novel solution to this problem, which is very compact and versatile and suits perfectly our technology. Another useful functional element when using SOAs is the pass-band filter to suppress ASE. We pursued two complimentary approaches: a suitable interleaved cascaded MZI filter, based on a novel suitably designed MMI coupler with pre-filtering capabilities, and a completely novel MMI resonator concept, to achieve larger free spectral ranges and narrower pass-band response. Simulation and design principles are presented and compared to preliminary experimental functional results, together with scaling rules and predictions of achievable RAM cell densities. When combined with our newly developed ultra-small light-turning concept, these new components are expected to pave the way for high integration density of RAM cells.

Less-invasive stabilization of rib fractures by intramedullary fixation: a biomechanical evaluation.

PubMed

Bottlang, Michael; Helzel, Inga; Long, William; Fitzpatrick, Daniel; Madey, Steven

2010-05-01

This study evaluated intramedullary fixation of rib fractures with Kirschner wires and novel ribs splints. We hypothesized that rib splints can provide equivalent fixation strength while avoiding complications associated with Kirschner wires, namely wire migration and cutout. The durability, strength, and failure modes of rib fracture fixation with Kirschner wires and rib splints were evaluated in 22 paired human ribs. First, intact ribs were loaded to failure to determine their strength. After fracture fixation with Kirschner wires and rib splints, fixation constructs were dynamically loaded to 360,000 cycles at five times the respiratory load to determine their durability. Finally, constructs were loaded to failure to determine residual strength and failure modes. All constructs sustained dynamic loading without failure. Dynamic loading caused three times more subsidence in Kirschner wire constructs (1.2 mm +/- 1.4 mm) than in rib splint constructs (0.4 mm +/- 0.2 mm, p = 0.09). After dynamic loading, rib splint constructs remained 48% stronger than Kirschner wire constructs (p = 0.001). Five of 11 Kirschner wire constructs failed catastrophically by cutting through the medial cortex, leading to complete loss of stability and wire migration through the lateral cortex. The remaining six constructs failed by wire bending. Rib splint constructs failed by development of fracture lines along the superior and interior cortices. No splint construct failed catastrophically, and all splint constructs retained functional reduction and fixation. Because of their superior strength and absence of catastrophic failure mode, rib splints can serve as an attractive alternative to Kirschner wires for intramedullary stabilization of rib fractures, especially in the case of posterior rib fractures where access for plating is limited.

Are first rib fractures a marker for other life-threatening injuries in patients with major trauma? A cohort study of patients on the UK Trauma Audit and Research Network database

PubMed Central

Sammy, Ian Ayenga; Chatha, Hridesh; Lecky, Fiona; Bouamra, Omar; Fragoso-Iñiguez, Marisol; Sattout, Abdo; Hickey, Michael; Edwards, John E

2017-01-01

Background First rib fractures are considered indicators of increased morbidity and mortality in major trauma. However, this has not been definitively proven. With an increased use of CT and the potential increase in detection of first rib fractures, re-evaluation of these injuries as a marker for life-threatening injuries is warranted. Methods Patients sustaining rib fractures between January 2012 and December 2013 were investigated using data from the UK Trauma Audit and Research Network. The prevalence of life-threatening injuries was compared in patients with first rib fractures and those with other rib fractures. Multivariate logistic regression was performed to determine the association between first rib fractures, injury severity, polytrauma and mortality. Results There were 1683 patients with first rib fractures and 8369 with fractures of other ribs. Life-threatening intrathoracic and extrathoracic injuries were more likely in patients with first rib fractures. The presence of first rib fractures was a significant predictor of injury severity (Injury Severity Score >15) and polytrauma, independent of mechanism of injury, age and gender with an adjusted OR of 2.64 (95% CI 2.33 to 3.00) and 2.01 (95% CI 1.80 to 2.25), respectively. Risk-adjusted mortality was the same in patients with first rib fractures and those with other rib fractures (adjusted OR 0.97, 95% CI 0.79 to 1.19). Conclusion First rib fractures are a marker of life-threatening injuries in major trauma, though they do not independently increase mortality. Management of patients with first rib fractures should focus on identification and treatment of associated life-threatening injuries. PMID:28119351

Segmentation of ribs in digital chest radiographs

NASA Astrophysics Data System (ADS)

Cong, Lin; Guo, Wei; Li, Qiang

2016-03-01

Ribs and clavicles in posterior-anterior (PA) digital chest radiographs often overlap with lung abnormalities such as nodules, and cause missing of these abnormalities, it is therefore necessary to remove or reduce the ribs in chest radiographs. The purpose of this study was to develop a fully automated algorithm to segment ribs within lung area in digital radiography (DR) for removal of the ribs. The rib segmentation algorithm consists of three steps. Firstly, a radiograph was pre-processed for contrast adjustment and noise removal; second, generalized Hough transform was employed to localize the lower boundary of the ribs. In the third step, a novel bilateral dynamic programming algorithm was used to accurately segment the upper and lower boundaries of ribs simultaneously. The width of the ribs and the smoothness of the rib boundaries were incorporated in the cost function of the bilateral dynamic programming for obtaining consistent results for the upper and lower boundaries. Our database consisted of 93 DR images, including, respectively, 23 and 70 images acquired with a DR system from Shanghai United-Imaging Healthcare Co. and from GE Healthcare Co. The rib localization algorithm achieved a sensitivity of 98.2% with 0.1 false positives per image. The accuracy of the detected ribs was further evaluated subjectively in 3 levels: "1", good; "2", acceptable; "3", poor. The percentages of good, acceptable, and poor segmentation results were 91.1%, 7.2%, and 1.7%, respectively. Our algorithm can obtain good segmentation results for ribs in chest radiography and would be useful for rib reduction in our future study.

Epidemiology of rib fractures in older men: Osteoporotic Fractures in Men (MrOS) prospective cohort study.

PubMed

Barrett-Connor, Elizabeth; Nielson, Carrie M; Orwoll, Eric; Bauer, Douglas C; Cauley, Jane A

2010-03-15

To study the causes and consequences of radiologically confirmed rib fractures (seldom considered in the context of osteoporosis) in community dwelling older men. Prospective cohort study (Osteoporotic Fractures in Men (MrOS) Study). 5995 men aged 65 or over recruited in 2000-2 from six US sites; 99% answered mailed questionnaires about falls and fractures every four months for a mean 6.2 (SD 1.3) year follow-up. New fractures validated by radiology reports; multivariate Cox proportional hazard ratios were used to evaluate factors independently associated with time to incident rib fracture; associations between baseline rib fracture and incident hip and wrist fracture were also evaluated. The incidence of rib fracture was 3.5/1000 person years, and 24% (126/522) of all incident non-spine fractures were rib fractures. Nearly half of new rib fractures (48%; n=61) followed falling from standing height or lower. Independent risk factors for an incident rib fracture were age 80 or above, low bone density, difficulty with instrumental activities of daily living, and a baseline history of rib/chest fracture. Men with a history of rib/chest fracture had at least a twofold increased risk of an incident rib fracture (adjusted hazard ratio 2.71, 95% confidence interval 1.86 to 3.95), hip fracture (2.05, 1.33 to 3.15), and wrist fracture (2.06, 1.14 to 3.70). Only 14/82 of men reported being treated with bone specific drugs after their incident rib fracture. Rib fracture, the most common incident clinical fracture in men, was associated with classic risk markers for osteoporosis, including old age, low hip bone mineral density, and history of fracture. A history of rib fracture predicted a more than twofold increased risk of future fracture of the rib, hip, or wrist, independent of bone density and other covariates. Rib fractures should be considered to be osteoporotic fractures in the evaluation of older men for treatment to prevent future fracture.

Rib Fracture Diagnosis in the Panscan Era.

PubMed

Murphy, Charles E; Raja, Ali S; Baumann, Brigitte M; Medak, Anthony J; Langdorf, Mark I; Nishijima, Daniel K; Hendey, Gregory W; Mower, William R; Rodriguez, Robert M

2017-12-01

With increased use of chest computed tomography (CT) in trauma evaluation, traditional teachings in regard to rib fracture morbidity and mortality may no longer be accurate. We seek to determine rates of rib fracture observed on chest CT only; admission and mortality of patients with isolated rib fractures, rib fractures observed on CT only, and first or second rib fractures; and first or second rib fracture-associated great vessel injury. We conducted a planned secondary analysis of 2 prospectively enrolled cohorts of the National Emergency X-Radiography Utilization Study chest studies, which evaluated patients with blunt trauma who were older than 14 years and received chest imaging in the emergency department. We defined rib fractures and other thoracic injuries according to CT reports and followed patients through their hospital course to determine outcomes. Of 8,661 patients who had both chest radiograph and chest CT, 2,071 (23.9%) had rib fractures, and rib fractures were observed on chest CT only in 1,368 cases (66.1%). Rib fracture patients had higher admission rates (88.7% versus 45.8%; mean difference 42.9%; 95% confidence interval [CI] 41.4% to 44.4%) and mortality (5.6% versus 2.7%; mean difference 2.9%; 95% CI 1.8% to 4.0%) than patients without rib fracture. The mortality of patients with rib fracture observed on chest CT only was not statistically significantly different from that of patients with fractures also observed on chest radiograph (4.8% versus 5.7%; mean difference -0.9%; 95% CI -3.1% to 1.1%). Patients with first or second rib fractures had significantly higher mortality (7.4% versus 4.1%; mean difference 3.3%; 95% CI 0.2% to 7.1%) and prevalence of concomitant great vessel injury (2.8% versus 0.6%; mean difference 2.2%; 95% CI 0.6% to 4.9%) than patients with fractures of ribs 3 to 12, and the odds ratio of great vessel injury with first or second rib fracture was 4.4 (95% CI 1.8 to 10.4). Under trauma imaging protocols that commonly incorporate chest CT, two thirds of rib fractures were observed on chest CT only. Patients with rib fractures had higher admission rates and mortality than those without rib fractures. First or second rib fractures were associated with significantly higher mortality and great vessel injury. Copyright © 2017 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Case report: clinical and postmortem findings in four cows with rib fracture.

PubMed

Braun, Ueli; Warislohner, Sonja; Hetzel, Udo; Nuss, Karl

2017-02-06

Published reports of rib fractures in adult cattle are limited to the occurrence of chronic rib swellings caused by calluses, which are unremarkable from a clinical standpoint, whereas studies identifying clinical signs of rib fractures were not found in a literature search. This report describes the clinical and postmortem findings in four cows with rib fractures. The 13th rib was fractured in three cows and the 11th rib in the remaining cow; three fractures were on the right and one on the left side. Clinical and postmortem findings varied considerably, and percussion of the rib cage elicited a pain response in only one cow. One cow had generalised peritonitis because of perforation of the rumen by the fractured rib. One cow was recumbent because of pain and became a downer cow, and two other cows had bronchopneumonia, which was a sequel to osteomyelitis of the fracture site in one. In the absence of a history of trauma, the diagnosis of rib fracture based on clinical signs alone is difficult. Although rib fractures undoubtedly are very painful, the four cases described in this report suggest that they are difficult to diagnose in cattle because associated clinical signs are nonspecific.

Nineth Rib Syndrome after 10(th) Rib Resection.

PubMed

Yu, Hyun Jeong; Jeong, Yu Sub; Lee, Dong Hoon; Yim, Kyoung Hoon

2016-07-01

The 12(th) rib syndrome is a disease that causes pain between the upper abdomen and the lower chest. It is assumed that the impinging on the nerves between the ribs causes pain in the lower chest, upper abdomen, and flank. A 74-year-old female patient visited a pain clinic complaining of pain in her back, and left chest wall at a 7 on the 0-10 Numeric Rating scale (NRS). She had a lateral fixation at T12-L2, 6 years earlier. After the operation, she had multiple osteoporotic compression fractures. When the spine was bent, the patient complained about a sharp pain in the left mid-axillary line and radiating pain toward the abdomen. On physical examination, the 10(th) rib was not felt, and an image of the rib-cage confirmed that the left 10(th) rib was severed. When applying pressure from the legs to the 9(th) rib of the patient, pain was reproduced. Therefore, the patient was diagnosed with 9(th) rib syndrome, and ultrasound-guided 9(th) and 10(th) intercostal nerve blocks were performed around the tips of the severed 10(th) rib. In addition, local anesthetics with triamcinolone were administered into the muscles beneath the 9(th) rib at the point of the greatest tenderness. The patient's pain was reduced to NRS 2 point. In this case, it is suspected that the patient had a partial resection of the left 10(th) rib in the past, and subsequent compression fractures at T8 and T9 led to the deformation of the rib cage, causing the tip of the remaining 10(th) rib to impinge on the 9(th) intercostal nerves, causing pain.

A rib-specific multimodal registration algorithm for fused unfolded rib visualization using PET/CT

NASA Astrophysics Data System (ADS)

Kaftan, Jens N.; Kopaczka, Marcin; Wimmer, Andreas; Platsch, Günther; Declerck, Jérôme

2014-03-01

Respiratory motion affects the alignment of PET and CT volumes from PET/CT examinations in a non-rigid manner. This becomes particularly apparent if reviewing fine anatomical structures such as ribs when assessing bone metastases, which frequently occur in many advanced cancers. To make this routine diagnostic task more efficient, a fused unfolded rib visualization for 18F-NaF PET/CT is presented. It allows to review the whole rib cage in a single image. This advanced visualization is enabled by a novel rib-specific registration algorithm that rigidly optimizes the local alignment of each individual rib in both modalities based on a matched filter response function. More specifically, rib centerlines are automatically extracted from CT and subsequently individually aligned to the corresponding bone-specific PET rib uptake pattern. The proposed method has been validated on 20 PET/CT scans acquired at different clinical sites. It has been demonstrated that the presented rib- specific registration method significantly improves the rib alignment without having to run complex deformable registration algorithms. At the same time, it guarantees that rib lesions are not further deformed, which may otherwise affect quantitative measurements such as SUVs. Considering clinically relevant distance thresholds, the centerline portion with good alignment compared to the ground truth improved from 60:6% to 86:7% after registration while approximately 98% can be still considered as acceptably aligned.

Model based rib-cage unfolding for trauma CT

NASA Astrophysics Data System (ADS)

von Berg, Jens; Klinder, Tobias; Lorenz, Cristian

2018-03-01

A CT rib-cage unfolding method is proposed that does not require to determine rib centerlines but determines the visceral cavity surface by model base segmentation. Image intensities are sampled across this surface that is flattened using a model based 3D thin-plate-spline registration. An average rib centerline model projected onto this surface serves as a reference system for registration. The flattening registration is designed so that ribs similar to the centerline model are mapped onto parallel lines preserving their relative length. Ribs deviating from this model appear deviating from straight parallel ribs in the unfolded view, accordingly. As the mapping is continuous also the details in intercostal space and those adjacent to the ribs are rendered well. The most beneficial application area is Trauma CT where a fast detection of rib fractures is a crucial task. Specifically in trauma, automatic rib centerline detection may not be guaranteed due to fractures and dislocations. The application by visual assessment on the large public LIDC data base of lung CT proved general feasibility of this early work.

A novel ex vivo model of compressive immature rib fractures at pathophysiological rates of loading.

PubMed

Beadle, Nicola; Burnett, Timothy L; Hoyland, Judith A; Sherratt, Michael J; Freemont, Anthony J

2015-11-01

Compressive rib fractures are considered to be indicative of non-accidental injury (NAI) in infants, which is a significant and growing issue worldwide. The diagnosis of NAI is often disputed in a legal setting, and as a consequence there is a need to model such injuries ex vivo in order to characterise the forces required to produce non-accidental rib fractures. However, current models are limited by type of sample, loading method and rate of loading. Here, we aimed to: i) develop a loading system for inducing compressive fractures in whole immature ribs that is more representative of the physiological conditions and mechanism of injury employed in NAI and ii) assess the influence of loading rate and rib geometry on the mechanical performance of the tissue. Porcine ribs (5-6 weeks of age) from 12 animals (n=8 ribs/animal) were subjected to axial compressive load directed through the anterior-posterior rib axis at loading rates of 1, 30, 60 or 90 mm/s. Key mechanical parameters (including peak load, load and percentage deformation to failure and effective stiffness) were quantified from the load-displacement curves. Measurements of the rib length, thickness at midpoint, distance between anterior and posterior extremities, rib curvature and fracture location were determined from radiographs. This loading method typically produced incomplete fractures around the midpoint of the ribs, with 87% failing in this manner; higher loads and less deformation were required for ribs to completely fracture through both cortices. Loading rate, within the range of 1-90 mm/s, did not significantly affect any key mechanical parameters of the ribs. Load-displacement curves displaying characteristic and quantifiable features were produced for 90% of the ribs tested, and multiple regression analyses indicate that, in addition to the geometrical variables, there are other factors such as the micro- and nano-structure that influence the measured mechanical data. A reproducible method of inducing fractures in a consistent location in immature porcine ribs has been successfully developed. Fracture appearance may be indicative of the amount of load and deformation that produced the fracture, which is an important finding for NAI, where knowledge of the aetiology of fractures is vital. Characteristic rib behaviour independent of loading rate and, to an extent, rib geometry has been demonstrated, allowing further investigation into how the complex micro- and nano-structure of immature ribs influences the mechanical performance under compressive load. This research will ultimately enable improved characterisation of the loading pattern involved in non-accidental rib fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Heat transfer and friction characteristics of the microfluidic heat sink with variously-shaped ribs for chip cooling.

PubMed

Wang, Gui-Lian; Yang, Da-Wei; Wang, Yan; Niu, Di; Zhao, Xiao-Lin; Ding, Gui-Fu

2015-04-22

This paper experimentally and numerically investigated the heat transfer and friction characteristics of microfluidic heat sinks with variously-shaped micro-ribs, i.e., rectangular, triangular and semicircular ribs. The micro-ribs were fabricated on the sidewalls of microfluidic channels by a surface-micromachining micro-electro-mechanical system (MEMS) process and used as turbulators to improve the heat transfer rate of the microfluidic heat sink. The results indicate that the utilizing of micro-ribs provides a better heat transfer rate, but also increases the pressure drop penalty for microchannels. Furthermore, the heat transfer and friction characteristics of the microchannels are strongly affected by the rib shape. In comparison, the triangular ribbed microchannel possesses the highest Nusselt number and friction factor among the three rib types.

Are first rib fractures a marker for other life-threatening injuries in patients with major trauma? A cohort study of patients on the UK Trauma Audit and Research Network database.

PubMed

Sammy, Ian Ayenga; Chatha, Hridesh; Lecky, Fiona; Bouamra, Omar; Fragoso-Iñiguez, Marisol; Sattout, Abdo; Hickey, Michael; Edwards, John E

2017-04-01

First rib fractures are considered indicators of increased morbidity and mortality in major trauma. However, this has not been definitively proven. With an increased use of CT and the potential increase in detection of first rib fractures, re-evaluation of these injuries as a marker for life-threatening injuries is warranted. Patients sustaining rib fractures between January 2012 and December 2013 were investigated using data from the UK Trauma Audit and Research Network. The prevalence of life-threatening injuries was compared in patients with first rib fractures and those with other rib fractures. Multivariate logistic regression was performed to determine the association between first rib fractures, injury severity, polytrauma and mortality. There were 1683 patients with first rib fractures and 8369 with fractures of other ribs. Life-threatening intrathoracic and extrathoracic injuries were more likely in patients with first rib fractures. The presence of first rib fractures was a significant predictor of injury severity (Injury Severity Score >15) and polytrauma, independent of mechanism of injury, age and gender with an adjusted OR of 2.64 (95% CI 2.33 to 3.00) and 2.01 (95% CI 1.80 to 2.25), respectively. Risk-adjusted mortality was the same in patients with first rib fractures and those with other rib fractures (adjusted OR 0.97, 95% CI 0.79 to 1.19). First rib fractures are a marker of life-threatening injuries in major trauma, though they do not independently increase mortality. Management of patients with first rib fractures should focus on identification and treatment of associated life-threatening injuries. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) [year]. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Rib fractures and death from deletion of osteoblast βcatenin in adult mice is rescued by corticosteroids.

PubMed

Duan, JinZhu; Lee, Yueh; Jania, Corey; Gong, Jucheng; Rojas, Mauricio; Burk, Laurel; Willis, Monte; Homeister, Jonathon; Tilley, Stephen; Rubin, Janet; Deb, Arjun

2013-01-01

Ribs are primarily made of cortical bone and are necessary for chest expansion and ventilation. Rib fractures represent the most common type of non-traumatic fractures in the elderly yet few studies have focused on the biology of rib fragility. Here, we show that deletion of βcatenin in Col1a2 expressing osteoblasts of adult mice leads to aggressive osteoclastogenesis with increased serum levels of the osteoclastogenic cytokine RANKL, extensive rib resorption, multiple spontaneous rib fractures and chest wall deformities. Within days of osteoblast specific βcatenin deletion, animals die from respiratory failure with a vanishing rib cage that is unable to sustain ventilation. Increased bone resorption is also observed in the vertebrae and femur. Treatment with the bisphosphonate pamidronate delayed but did not prevent death or associated rib fractures. In contrast, administration of the glucocorticoid dexamethasone decreased serum RANKL and slowed osteoclastogenesis. Dexamethasone preserved rib structure, prevented respiratory compromise and strikingly increased survival. Our findings provide a novel model of accelerated osteoclastogenesis, where deletion of osteoblast βcatenin in adults leads to rapid development of destructive rib fractures. We demonstrate the role of βcatenin dependent mechanisms in rib fractures and suggest that glucocorticoids, by suppressing RANKL, may have a role in treating bone loss due to aggressive osteoclastogenesis.

Rib Fractures and Death from Deletion of Osteoblast βcatenin in Adult Mice Is Rescued by Corticosteroids

PubMed Central

Duan, JinZhu; Lee, Yueh; Jania, Corey; Gong, Jucheng; Rojas, Mauricio; Burk, Laurel; Willis, Monte; Homeister, Jonathon; Tilley, Stephen; Rubin, Janet; Deb, Arjun

2013-01-01

Ribs are primarily made of cortical bone and are necessary for chest expansion and ventilation. Rib fractures represent the most common type of non-traumatic fractures in the elderly yet few studies have focused on the biology of rib fragility. Here, we show that deletion of βcatenin in Col1a2 expressing osteoblasts of adult mice leads to aggressive osteoclastogenesis with increased serum levels of the osteoclastogenic cytokine RANKL, extensive rib resorption, multiple spontaneous rib fractures and chest wall deformities. Within days of osteoblast specific βcatenin deletion, animals die from respiratory failure with a vanishing rib cage that is unable to sustain ventilation. Increased bone resorption is also observed in the vertebrae and femur. Treatment with the bisphosphonate pamidronate delayed but did not prevent death or associated rib fractures. In contrast, administration of the glucocorticoid dexamethasone decreased serum RANKL and slowed osteoclastogenesis. Dexamethasone preserved rib structure, prevented respiratory compromise and strikingly increased survival. Our findings provide a novel model of accelerated osteoclastogenesis, where deletion of osteoblast βcatenin in adults leads to rapid development of destructive rib fractures. We demonstrate the role of βcatenin dependent mechanisms in rib fractures and suggest that glucocorticoids, by suppressing RANKL, may have a role in treating bone loss due to aggressive osteoclastogenesis. PMID:23393600

Biomechanical investigation of different surgical strategies for the treatment of rib fractures using a three-dimensional human respiratory model.

PubMed

Shih, Kao-Shang; Truong, Thanh An; Hsu, Ching-Chi; Hou, Sheng-Mou

2017-11-02

Rib fracture is a common injury and can result in pain during respiration. Conservative treatment of rib fracture is applied via mechanical ventilation. However, ventilator-associated complications frequently occur. Surgical fixation is another approach to treat rib fractures. Unfortunately, this surgical treatment is still not completely defined. Past studies have evaluated the biomechanics of the rib cage during respiration using a finite element method, but only intact conditions were modelled. Thus, the purpose of this study was to develop a realistic numerical model of the human rib cage and to analyse the biomechanical performance of intact, injured and treated rib cages. Three-dimensional finite element models of the human rib cage were developed. Respiratory movement of the human rib cage was simulated to evaluate the strengths and limitations of different scenarios. The results show that a realistic human respiratory movement can be simulated and the predicted results were closely related to previous study (correlation coefficient>0.92). Fixation of two fractured ribs significantly decreased the fixation index (191%) compared to the injured model. This fixation may provide adequate fixation stability as well as reveal lower bone stress and implant stress compared with the fixation of three or more fractured ribs.

Diagnostic value and clinical laboratory associations of antibodies against recombinant ribosomal P0, P1 and P2 proteins and their native heterocomplex in a Caucasian cohort with systemic lupus erythematosus.

PubMed

Barkhudarova, Fidan; Dähnrich, Cornelia; Rosemann, Anke; Schneider, Udo; Stöcker, Winfried; Burmester, Gerd-Rüdiger; Egerer, Karl; Schlumberger, Wolfgang; Hiepe, Falk; Biesen, Robert

2011-02-10

In this study, we sought to determine the diagnostic value and clinical laboratory associations of autoantibodies against recombinant ribosomal P0, P1 and P2 proteins and their native heterocomplex in systemic lupus erythematosus (SLE). Autoantibodies against recombinant ribosomal P proteins (aRibPR0, aRibPR1 and aRibPR2) and antibodies against native ribosomal P heterocomplex (aRibPNH) were determined in sera from patients with SLE (n = 163), systemic sclerosis (n = 66), Sjögren's syndrome (n = 54), rheumatoid arthritis (n = 90) and healthy donors (n = 100) using enzyme-linked immunosorbent assay. Test results were correlated to medical records, including the American College of Rheumatology criteria, the Systemic Lupus Erythematosus Disease Activity Index 2000, laboratory data and medications of all SLE patients. Sensitivities of 22.0% for aRibPR0, 14.9% for aRibPR2, 14.3% for aRibPNH and 10.7% for aRibPR1 were obtained at a specificity of 99%. The assay for aRibPR0 detection demonstrated the best performance in receiver-operating characteristics analysis, with aRibPR0 detectable in 10% of anti-Smith antibody and anti-double-stranded DNA-negative sera at a specificity of 100%. ARibPR0 positivity was associated with lymphocytopenia. ARibPR1+ patients had significantly higher γ-glutamyl transpeptidase (GGT) levels than their aRibPR1- counterparts. No specific damage occurred in aRibP+ lupus patients compared with a group of age-, sex- and nephritis-matched aRibP- lupus patients within 3 years. The determination of antibodies against ribosomal P proteins improves the diagnosis of SLE and should therefore be implemented in upcoming criteria for the diagnosis or classification of SLE. High titers of aRibPR0 can be associated with lymphocytopenia, and high titers of aRibPR1 can be associated with elevated GGT levels. So far, there is no evidence for a prognostic value of aRibPs for damage.

The number of displaced rib fractures is more predictive for complications in chest trauma patients.

PubMed

Chien, Chih-Ying; Chen, Yu-Hsien; Han, Shih-Tsung; Blaney, Gerald N; Huang, Ting-Shuo; Chen, Kuan-Fu

2017-02-28

Traumatic rib fractures can cause chest complications that need further treatment and hospitalization. We hypothesized that an increase in the number of displaced rib fractures will be accompanied by an increase in chest complications. We retrospectively reviewed the trauma registry between January 2013 and May 2015 in a teaching hospital in northeastern Taiwan. Patients admitted with chest trauma and rib fractures without concomitant severe brain, splenic, pelvic or liver injuries were included. The demographic data, such as gender, age, the index of coexistence disease, alcohol consumption, trauma mechanisms were analyzed as potential predictors of pulmonary complications. Pulmonary complications were defined as pneumothorax, hemothorax, flail chest, pulmonary contusion, and pneumonia. In the 29 months of the study period, a total of 3151 trauma patients were admitted to our hospital. Among them, 174 patients were enrolled for final analysis. The most common trauma mechanism was road traffic accidents (58.6%), mainly motorbike accidents (n = 70, 40.2%). Three or more displaced rib fractures had higher specificity for predicting complications, compared to three or more total rib fractures (95.5% vs 59.1%). Adjusting the severity of chest trauma using TTSS and Ribscore by multivariable logistic regression analysis, we found that three or more rib fractures or any displaced rib fracture was the most significant predictor for developing pulmonary complication (aOR: 5.49 95% CI: 1.82-16.55). Furthermore, there were 18/57 (31.6%) patients with fewer than three ribs fractures developed pulmonary complications. In these 18 patients, only five patients had delayed onset complications and four of them had at least one displaced rib fracture. In this retrospective cohort study, we found that the number of displaced or total rib fractures, bilateral rib fractures, and rib fractures in more than two areas were associated with the more chest complications. Furthermore, three or more rib fracture or any displacement were found to be the most sensitive risk factor for chest complications, independent of other risk factors or severity index. The number of displaced rib fractures could be a strong predictor for developing pulmonary complications. For patients with fewer than three rib fractures without rib displacement and initial lung or other organ injuries, outpatient management could be safe and efficient.

Trial of Injected Liposomal Bupivacaine vs Bupivacaine Infusion After Surgical Stabilization of Rib Fractures

ClinicalTrials.gov

2017-10-06

Drug Effect; Rib Fractures; Rib Trauma; Surgical Procedure, Unspecified; Pain; Catheter (Other); Nerve Pain; Local Infiltration; Anesthesia, Local; Intercostal Rib; Opioid Dependence; Chest Injury Trauma; Pneumonia

Computed Tomography Measurement of Rib Cage Morphometry in Emphysema

PubMed Central

Sverzellati, Nicola; Colombi, Davide; Randi, Giorgia; Pavarani, Antonio; Silva, Mario; Walsh, Simon L.; Pistolesi, Massimo; Alfieri, Veronica; Chetta, Alfredo; Vaccarezza, Mauro; Vitale, Marco; Pastorino, Ugo

2013-01-01

Background Factors determining the shape of the human rib cage are not completely understood. We aimed to quantify the contribution of anthropometric and COPD-related changes to rib cage variability in adult cigarette smokers. Methods Rib cage diameters and areas (calculated from the inner surface of the rib cage) in 816 smokers with or without COPD, were evaluated at three anatomical levels using computed tomography (CT). CTs were analyzed with software, which allows quantification of total emphysema (emphysema%). The relationship between rib cage measurements and anthropometric factors, lung function indices, and %emphysema were tested using linear regression models. Results A model that included gender, age, BMI, emphysema%, forced expiratory volume in one second (FEV1)%, and forced vital capacity (FVC)% fit best with the rib cage measurements (R2 = 64% for the rib cage area variation at the lower anatomical level). Gender had the biggest impact on rib cage diameter and area (105.3 cm2; 95% CI: 111.7 to 98.8 for male lower area). Emphysema% was responsible for an increase in size of upper and middle CT areas (up to 5.4 cm2; 95% CI: 3.0 to 7.8 for an emphysema increase of 5%). Lower rib cage areas decreased as FVC% decreased (5.1 cm2; 95% CI: 2.5 to 7.6 for 10 percentage points of FVC variation). Conclusions This study demonstrates that simple CT measurements can predict rib cage morphometric variability and also highlight relationships between rib cage morphometry and emphysema. PMID:23935872

ribB and ribBA genes from Acidithiobacillus ferrooxidans: expression levels under different growth conditions and phylogenetic analysis.

PubMed

Knegt, Fábio H P; Mello, Luciane V; Reis, Fernanda C; Santos, Marcos T; Vicentini, Renato; Ferraz, Lúcio F C; Ottoboni, Laura M M

2008-01-01

Acidithiobacillus ferrooxidans is a Gram-negative, chemolithoautotrophic bacterium involved in metal bioleaching. Using the RNA arbitrarily primed polymerase chain reaction (RAP-PCR), we have identified several cDNAs that were differentially expressed when A. ferrooxidans LR was submitted to potassium- and phosphate-limiting conditions. One of these cDNAs showed similarity with ribB. An analysis of the A. ferrooxidans ATCC 23270 genome, made available by The Institute for Genomic Research, showed that the ribB gene was not located in the rib operon, but a ribBA gene was present in this operon instead. The ribBA gene was isolated from A. ferrooxidans LR and expression of both ribB and ribBA was investigated. Transcript levels of both genes were enhanced in cells grown in the absence of K2HPO4, in the presence of zinc and copper sulfate and in different pHs. Transcript levels decreased upon exposure to a temperature higher than the ideal 30 degrees C and at pH 1.2. A comparative genomic analysis using the A. ferrooxidans ATCC 23270 genome revealed similar putative regulatory elements for both genes. Moreover, an RFN element was identified upstream from the ribB gene. Phylogenetic analysis of the distribution of RibB and RibBA in bacteria showed six different combinations. We suggest that the presence of duplicated riboflavin synthesis genes in bacteria must provide their host with some benefit in certain stressful situations.

Comparative Study of Convective Heat Transfer Performance of Steam and Air Flow in Rib Roughened Channels

NASA Astrophysics Data System (ADS)

Ma, Chao; Ji, Yongbin; Ge, Bing; Zang, Shusheng; Chen, Hua

2018-04-01

A comparative experimental study of heat transfer characteristics of steam and air flow in rectangular channels roughened with parallel ribs was conducted by using an infrared camera. Effects of Reynolds numbers and rib angles on the steam and air convective heat transfer have been obtained and compared with each other for the Reynolds number from about 4,000 to 15,000. For all the ribbed channels the rib pitch to height ratio (p/e) is 10, and the rib height to the channel hydraulic diameter ratio is 0.078, while the rib angles are varied from 90° to 45°. Based on experimental results, it can be found that, even though the heat transfer distributions of steam and air flow in the ribbed channels are similar to each other, the steam flow can obtain higher convective heat transfer enhancement capability, and the heat transfer enhancement of both the steam and air becomes greater with the rib angle deceasing from 90° to 45°. At Reynolds number of about 12,000, the area-averaged Nusselt numbers of the steam flow is about 13.9%, 14.2%, 19.9% and 23.9% higher than those of the air flow for the rib angles of 90°, 75°, 60° and 45° respectively. With the experimental results the correlations for Nusselt number in terms of Reynolds number and rib angle for the steam and air flow in the ribbed channels were developed respectively.

Traumatic Rib Injury: Patterns, Imaging Pitfalls, Complications, and Treatment.

PubMed

Talbot, Brett S; Gange, Christopher P; Chaturvedi, Apeksha; Klionsky, Nina; Hobbs, Susan K; Chaturvedi, Abhishek

2017-01-01

The ribs are frequently affected by blunt or penetrating injury to the thorax. In the emergency department setting, it is vital for the interpreting radiologist to not only identify the presence of rib injuries but also alert the clinician about organ-specific injury, specific traumatic patterns, and acute rib trauma complications that require emergent attention. Rib injuries can be separated into specific morphologic fracture patterns that include stress, buckle, nondisplaced, displaced, segmental, and pathologic fractures. Specific attention is also required for flail chest and for fractures due to pediatric nonaccidental trauma. Rib fractures are associated with significant morbidity and mortality, both of which increase as the number of fractured ribs increases. Key complications associated with rib fracture include pain, hemothorax, pneumothorax, extrapleural hematoma, pulmonary contusion, pulmonary laceration, acute vascular injury, and abdominal solid-organ injury. Congenital anomalies, including supernumerary or accessory ribs, vestigial anterior ribs, bifid ribs, and synostoses, are common and should not be confused with traumatic pathologic conditions. Nontraumatic mimics of traumatic rib injury, with or without fracture, include metastatic disease, primary osseous neoplasms (osteosarcoma, chondrosarcoma, Ewing sarcoma, Langerhans cell histiocytosis, and osteochondroma), fibrous dysplasia, and Paget disease. Principles of management include supportive and procedural methods of alleviating pain, treating complications, and stabilizing posttraumatic deformity. By recognizing and accurately reporting the imaging findings, the radiologist will add value to the care of patients with thoracic trauma. Online supplemental material is available for this article. © RSNA, 2017.

Rib fixation for severe chest deformity due to multiple rib fractures.

PubMed

Igai, Hitoshi; Kamiyoshihara, Mitsuhiro; Nagashima, Toshiteru; Ohtaki, Yoichi

2012-01-01

The operative indications for rib fracture repair have been a matter of debate. However, several reports have suggested that flail chest, pain on respiration, and chest deformity/defect are potential conditions for rib fracture repair. We describe our experience of rib fixation in a patient with severe chest deformity due to multiple rib fractures. A 70-year-old woman was admitted with right-sided multiple rib fractures (2nd to 7th) and marked chest wall deformity without flailing caused by an automobile accident. Collapse of the chest wall was observed along the middle anterior axillary line. At 11 days after the injury, surgery was performed to repair the chest deformity, as it was considered to pose a risk of restrictive impairment of pulmonary function or chronic intercostal pain in the future. Operative findings revealed marked displacement of the superior 4 ribs, from the 2nd to the 5th, and collapse of the osseous chest wall towards the thoracic cavity. After exposure of the fracture regions, ribs fixations were performed using rib staplers. The total operation time was 90 minutes, and the collapsed portion of the chest wall along the middle anterior axillary line was reconstructed successfully.

Experimental and numerical analysis of interlocking rib formation at sheet metal blanking

NASA Astrophysics Data System (ADS)

Bolka, Špela; Bratuš, Vitoslav; Starman, Bojan; Mole, Nikolaj

2018-05-01

Cores for electrical motors are typically produced by blanking of laminations and then stacking them together, with, for instance, interlocking ribs or welding. Strict geometrical tolerances, both on the lamination and on the stack, combined with complex part geometry and harder steel strip material, call for use of predictive methods to optimize the process before actual blanking to reduce the costs and speed up the process. One of the major influences on the final stack geometry is the quality of the interlocking ribs. A rib is formed in one step and joined with the rib of the preceding lamination in the next. The quality of the joint determines the firmness of the stack and also influences its. The geometrical and positional accuracy is thus crucial in rib formation process. In this study, a complex experimental and numerical analysis of interlocking rib formation has been performed. The aim of the analysis is to numerically predict the shape of the rib in order to perform a numerical simulation of the stack formation in the next step of the process. A detailed experimental research has been performed in order to characterize influential parameters on the rib formation and the geometry of the ribs itself, using classical and 3D laser microscopy. The formation of the interlocking rib is then simulated using Abaqus Explicit. The Hilll 48 constitutive material model is based on extensive and novel material characterization process, combining data from in-plane and out-of-plane material tests to perform a 3D analysis of both, rib formation and rib joining. The study shows good correlation between the experimental and numerical results.

Association of Ipsilateral Rib Fractures With Displacement of Midshaft Clavicle Fractures.

PubMed

Stahl, Daniel; Ellington, Matthew; Brennan, Kindyle; Brennan, Michael

2017-04-01

To determine whether the presence of ipsilateral rib fractures affects the rate of a clavicle fracture being unstable (>100% displacement). A retrospective review from 2002-2013 performed at a single level 1 trauma center evaluated 243 midshaft clavicle fractures. Single Level 1 trauma center. These fractures were subdivided into those with ipsilateral rib fractures (CIR; n = 149) and those without ipsilateral rib fractures (CnIR; n = 94). The amount of displacement was measured on the initial injury radiograph and subsequent follow-up radiographs. Fractures were classified into either <100% displacement or >100% displacement, based on anteroposterior radiographs. Ipsilateral rib fractures were recorded based on which number rib was fractured and the total number of fractured ribs. One hundred sixteen (78%) of the CIR group and 51 (54%) of the CnIR group were found to have >100% displacement at follow-up (P = 0.0047). Seventy-two percent of the CIR group demonstrated progression from <100% to >100% displacement of the fracture compared with only 54% of the CnIR group (P < 0.05). The odds ratio for progression of the clavicle fracture to >100% was 4.08 (P = 0.000194) when ribs 1-4 were fractured and not significant for rib fractures 5-8 or 9-12. The presence of concomitant ipsilateral rib fractures significantly increases the rate of midshaft clavicle fractures being >100% displaced. In addition, a fracture involving the upper one-third of the ribs significantly increases the rate of the clavicle fracture being >100% displaced on early follow-up. Clavicle fractures with associated ipsilateral rib fractures tend to demonstrate an increased amount of displacement on follow-up radiographs compared with those without ipsilateral rib fractures. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Bone suppression technique for chest radiographs

NASA Astrophysics Data System (ADS)

Huo, Zhimin; Xu, Fan; Zhang, Jane; Zhao, Hui; Hobbs, Susan K.; Wandtke, John C.; Sykes, Anne-Marie; Paul, Narinder; Foos, David

2014-03-01

High-contrast bone structures are a major noise contributor in chest radiographic images. A signal of interest in a chest radiograph could be either partially or completely obscured or "overshadowed" by the highly contrasted bone structures in its surrounding. Thus, removing the bone structures, especially the posterior rib and clavicle structures, is highly desirable to increase the visibility of soft tissue density. We developed an innovative technology that offers a solution to suppress bone structures, including posterior ribs and clavicles, on conventional and portable chest X-ray images. The bone-suppression image processing technology includes five major steps: 1) lung segmentation, 2) rib and clavicle structure detection, 3) rib and clavicle edge detection, 4) rib and clavicle profile estimation, and 5) suppression based on the estimated profiles. The bone-suppression software outputs an image with both the rib and clavicle structures suppressed. The rib suppression performance was evaluated on 491 images. On average, 83.06% (±6.59%) of the rib structures on a standard chest image were suppressed based on the comparison of computer-identified rib areas against hand-drawn rib areas, which is equivalent to about an average of one rib that is still visible on a rib-suppressed image based on a visual assessment. Reader studies were performed to evaluate reader performance in detecting lung nodules and pneumothoraces with and without a bone-suppression companion view. Results from reader studies indicated that the bone-suppression technology significantly improved radiologists' performance in the detection of CT-confirmed possible nodules and pneumothoraces on chest radiographs. The results also showed that radiologists were more confident in making diagnoses regarding the presence or absence of an abnormality after rib-suppressed companion views were presented

Quantitative analysis of rib movement based on dynamic chest bone images: preliminary results

NASA Astrophysics Data System (ADS)

Tanaka, R.; Sanada, S.; Oda, M.; Mitsutaka, M.; Suzuki, K.; Sakuta, K.; Kawashima, H.

2014-03-01

Rib movement during respiration is one of the diagnostic criteria in pulmonary impairments. In general, the rib movement is assessed in fluoroscopy. However, the shadows of lung vessels and bronchi overlapping ribs prevent accurate quantitative analysis of rib movement. Recently, an image-processing technique for separating bones from soft tissue in static chest radiographs, called "bone suppression technique", has been developed. Our purpose in this study was to evaluate the usefulness of dynamic bone images created by the bone suppression technique in quantitative analysis of rib movement. Dynamic chest radiographs of 10 patients were obtained using a dynamic flat-panel detector (FPD). Bone suppression technique based on a massive-training artificial neural network (MTANN) was applied to the dynamic chest images to create bone images. Velocity vectors were measured in local areas on the dynamic bone images, which formed a map. The velocity maps obtained with bone and original images for scoliosis and normal cases were compared to assess the advantages of bone images. With dynamic bone images, we were able to quantify and distinguish movements of ribs from those of other lung structures accurately. Limited rib movements of scoliosis patients appeared as reduced rib velocity vectors. Vector maps in all normal cases exhibited left-right symmetric distributions, whereas those in abnormal cases showed nonuniform distributions. In conclusion, dynamic bone images were useful for accurate quantitative analysis of rib movements: Limited rib movements were indicated as a reduction of rib movement and left-right asymmetric distribution on vector maps. Thus, dynamic bone images can be a new diagnostic tool for quantitative analysis of rib movements without additional radiation dose.

Effects of Pin Detached Space on Heat Transfer in a Rib Roughened Channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siw, Sin Chien; Chyu, Minking K.; Alvin, Mary Anne

2012-11-08

An experimental study is performed to investigate the heat transfer characteristics and frictional losses in a rib roughened channel combined with detached pin-fins. The overall channel geometry (W=76.2 mm, E=25.4 mm) simulates an internal cooling passage of wide aspect ratio (3:1) in a gas turbine airfoil. With a given pin diameter, D=6.35 mm=[1/4]E, three different pin-fin height-to-diameter ratios, H/D=4, 3, and 2, were examined. Each of these three cases corresponds to a specific pin array geometry of detachment spacing (C) between the pin-tip and one of the endwalls, i.e., C/O=0, 1, 2, respectively. The rib height-to-channel height ratio is 0.0625.more » Two newly proposed cross ribs, namely the broken rib and full rib are evaluated in this effort. The broken ribs are positioned in between two consecutive rows of pin-fins, while the full ribs are fully extended adjacent to the pin-fins. The Reynolds number, based on the hydraulic diameter of the unobstructed cross section and the mean bulk velocity, ranges from 10,000 to 25,000. The experiment employs a hybrid technique based on transient liquid crystal imaging to obtain distributions of the local heat transfer coefficient over all of the participating surfaces, including the endwalls and all pin elements. The presence of ribs enhances local heat transfer coefficient on the endwall substantially by approximately 20% to 50% as compared to the neighboring endwall. In addition, affected by the rib geometry, which is a relatively low profile as compared to the overall height of the channel, the pressure loss seems to be insensitive to the presence of the ribs. However, from the overall heat transfer enhancement standpoint, the baseline cases (without ribs) outperform cases with broken ribs or full ribs.« less

Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54-56 Gy given in 9-7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size.

PubMed

Aoki, Masahiko; Sato, Mariko; Hirose, Katsumi; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Ono, Shuichi; Takai, Yoshihiro

2015-04-22

Radiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor. During 2003-2008, 41 patients with 42 lung tumors were treated with SBRT to 54-56 Gy in 9-7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study. Median follow-up time was 68 months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16-48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54 Gy were 47.7% and 12.9% (p = 0.0184), and for fraction size of 6, 7 and 8 Gy were 19.5%, 31.2% and 55.7% (p = 0.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10-55, age, sex, and planning target volume were not significantly different. The doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures.

Rib kinematics during lung ventilation in the American alligator (Alligator mississippiensis): an XROMM analysis

PubMed Central

Moritz, Sabine; Codd, Jonathan; Sellers, William I.

2017-01-01

ABSTRACT The current hypothesis regarding the mechanics of breathing in crocodylians is that the double-headed ribs, with both a capitulum and tuberculum, rotate about a constrained axis passing through the two articulations; moreover, this axis shifts in the caudal thoracic ribs, as the vertebral parapophysis moves from the centrum to the transverse process. Additionally, the ventral ribcage in crocodylians is thought to possess additional degrees of freedom through mobile intermediate ribs. In this study, X-ray reconstruction of moving morphology (XROMM) was used to quantify rib rotation during breathing in American alligators. Whilst costovertebral joint anatomy predicted overall patterns of motion across the ribcage (decreased bucket handle motion and increased calliper motion), there were significant deviations: anatomical axes overestimated pump handle motion and, generally, ribs in vivo rotate about all three body axes more equally than predicted. The intermediate ribs are mobile, with a high degree of rotation measured about the dorsal intracostal joints, especially in the more caudal ribs. Motion of the sternal ribs became increasingly complex caudally, owing to a combination of the movements of the vertebral and intermediate segments. As the crocodylian ribcage is sometimes used as a model for the ancestral archosaur, these results have important implications for how rib motion is reconstructed in fossil taxa, and illustrate the difficulties in reconstructing rib movement based on osteology alone. PMID:28855323

Ribbed moraine formation

NASA Astrophysics Data System (ADS)

Hättestrand, Clas; Kleman, Johan

Ribbed (Rogen) moraines are conspicuous landforms found in interior parts of formerly glaciated areas. Two major theories for ribbed moraine formation have been suggested in recent years: (i) the shear and stack theory, which explains ribbed moraine formation by shearing and stacking of till slabs or englacially entrained material during compressive flow, followed by basal melt-out of transverse moraine ridges, and (ii) the fracturing theory, according to which ribbed moraines form by fracturing of frozen pre-existing till sheets, at the transition from cold- to warm-based conditions under deglaciating ice sheets. In this paper, we present new data on the distribution of ribbed moraines and their close association with areas of frozen-bed conditions under ice sheets. In addition, we show examples of ribbed moraine ridges that fit together like a jig-saw puzzle. These observations indicate that fracturing and extension of a pre-existing till sheet may be a predominant process in ribbed moraine formation. In summary, we conclude that all described characteristics of ribbed moraines are compatible with the fracturing theory, while the shear and stack theory is hampered by an inability to explain many conspicuous features in the distribution pattern and detailed morphology of ribbed moraines. One implication of the fracturing theory is that the distribution of ribbed moraines can be used to reconstruct the extent of areas that underwent a change from frozen-bed to thawed-bed conditions under former ice sheets.

The Design of Airplane Wing Ribs

NASA Technical Reports Server (NTRS)

Newlin, J A; Trayer, George W

1931-01-01

The purpose of this investigation was to obtain information for use in the design of truss and plywood forms, particularly with reference to wing ribs. Tests were made on many designs of wing ribs, comparing different types in various sizes. Many tests were also made on parallel-chord specimens of truss and plywood forms in place of the actual ribs and on parts of wing ribs, such as truss diagonals and sections of cap strips. It was found that for ribs of any size or proportions, when they were designed to obtain a well-balanced construction and were carefully manufactured, distinct types are of various efficiencies; the efficiency is based on the strength per unit of weight. In all types of ribs the heavier are the stronger per unit of weight. Reductions in the weight of wing ribs are accompanied even in efficient designs by a much greater proportional reduction in strength.

Rib fracture repair: indications, technical issues, and future directions.

PubMed

Nirula, Raminder; Diaz, Jose J; Trunkey, Donald D; Mayberry, John C

2009-01-01

Rib fracture repair has been performed at selected centers around the world for more than 50 years; however, the operative indications have not been established and are considered controversial. The outcome of a strictly nonoperative approach may not be optimal. Potential indications for rib fracture repair include flail chest, painful, movable rib fractures refractory to conventional pain management, chest wall deformity/defect, rib fracture nonunion, and during thoracotomy for other traumatic indication. Rib fracture repair is technically challenging secondary to the human rib's relatively thin cortex and its tendency to fracture obliquely. Nonetheless, several effective repair systems have been developed. Future directions for progress on this important surgical problem include the development of minimally invasive techniques and the conduct of multicenter, randomized trials.

Rib fractures induced by coughing: an unusual cause of acute chest pain.

PubMed

De Maeseneer, M; De Mey, J; Debaere, C; Meysman, M; Osteaux, M

2000-03-01

We report three patients with stress fractures of the ribs induced by coughing. Standard radiographs of the chest and ribs did not reveal evidence of rib fractures in any of the patients. Bone scintigraphy, performed 1 to 2 weeks after initial onset of symptoms, showed a focal area of increased uptake along the chest wall in all cases. Thin section angulated helical CT directly visualized the subtle rib fractures. Initial diagnosis of a cough-induced fracture of the rib may be difficult because of the associated underlying disorder, and unnecessary examinations are commonly performed. Identification of a cough-induced fracture of the rib using helical CT may be clinically important to avoid unnecessary concern and additional examinations.

Comparison of ultrasonography and radiography in diagnosis of rib fractures.

PubMed

Pishbin, Elham; Ahmadi, Koorosh; Foogardi, Molood; Salehi, Maryam; Seilanian Toosi, Farrokh; Rahimi-Movaghar, Vafa

2017-08-01

Rib fractures are the most common skeletal thoracic injuries resulting from blunt chest trauma. Half of the rib fractures are not detected upon a precise physical evaluation and radiographs. Recently ultrasonography (USG) has been investigated to detect rib fractures. But based on literature the usefulness of USG varies widely. This study was conducted to investigate the role of USG in the detection of possible rib fractures in comparison with radiography. In this cross-sectional study, consecutive patients with minor blunt chest trauma and suspected rib fractures presenting in Imam Reza Hospital located in Mashhad-Iran, between April 2013 and October 2013 were assessed by USG and radiography. The radiography was performed in a posteroanterior (PA) chest projection and oblique rib view centered over the area of trauma. The time duration spent in taking USG and radiography were recorded. The prevalence and location of fractures revealed by USG and radiography were compared. Sixty-one suspected patients were assessed. The male to female ratio was 2.4:1 (43 men and 18 women) with a mean ± SD age of (44.3 ± 19.7) years. There were totally 59 rib fractures in 38 (62.3%) patients based on radiography and USG, while 23 (37.7%) patients had no diagnostic evidence of rib lesions. USG revealed 58 rib fractures in 33 (54.1%) of 61 suspected patients and radiographs revealed 32 rib fractures in 20 (32.8%) of 61 patients. A total of 58 (98.3%) rib fractures were detected by USG, whereas oblique rib view and PA chest radiography showed 27 (45.8%) and 24 (40.7%) rib fractures, respectively. The average duration of USG was (12 ± 3) min (range 7-17 min), whereas the duration of radiography was (27 ± 6) min (range 15-37 min). The kappa coefficient showed a low level of agreement between both USG and PA chest radiography (kappa coefficient = 0.28), and between USG and oblique rib view (kappa coefficient = 0.32). USG discloses more fractures than radiography in most patients presenting with suspected rib fractures. Moreover USG requires significantly less time than radiography. Copyright © 2017 Daping Hospital and the Research Institute of Surgery of the Third Military Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Rib fracture as a predictor of future fractures in young and older postmenopausal women: National Osteoporosis Risk Assessment (NORA)

PubMed Central

Sajjan, S. G.; Barrett-Connor, E.; McHorney, C. A.; Miller, P. D.; Sen, S. S.; Siris, E.

2013-01-01

Summary A rib fracture history after age 45 was associated with a 5.4-fold increase in new rib fracture risk and a 2.4-fold increase in risk of any new clinical fracture in 155,031 postmenopausal women. A rib fracture history suggests osteoporosis and should be considered when evaluating patients for interventions to prevent fractures. Introduction Until recently, little attention was paid to rib fracture as an osteoporosis marker. Emerging evidence suggests rib fracture may be an osteoporotic fracture in men and women. We report the 5-year independent association between baseline rib fracture histories and self-reported future fractures by age (decade) in the NORA cohort (155,031 postmenopausal women, 50–99 years). Methods Participants reported fracture history and responded to follow-up surveys at years 1, 3, or 6. Women with a baseline rib fracture history without other fractures were compared with women with no fracture. Results At baseline, 4,758 (3.07%) women reported a rib fracture history without other fractures; 6,300 women reported 6,830 new clinical fractures, including wrist (2,271), rib (1,891), spine (1,136), hip (941), and forearm (591). Adjusted relative risk (ARR) values (95% confidence interval [CI]) for future fractures in women with rib fracture history versus women with no fracture history were 5.4 (4.8–6.1) at the rib, 2.1 (1.7–2.6) at the spine, and 1.4 (1.1–1.7) at the wrist, and not significant for forearm or hip fractures. Future fracture risk was at least doubled in women with a rib fracture history in all ages: ARR (95% CI) 3.4 (2.8–4.0) for ages 50–59, 2.5 (2.1–3.0) for ages 60–69, 2.0 (1.7–2.3) for ages 70–79, and 2.0 (1.6–2.6) for ages >80. Conclusions Rib fracture, the second most common clinical fracture in women (after wrist fracture), predicted future fractures of the rib, wrist, and spine at all ages. Women presenting with rib fractures should be evaluated for appropriate management to prevent future fractures. PMID:21904951

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pokhrel, D; Sood, S; Badkul, R

Purpose: To evaluate XVMC computed rib doses for peripherally located non-small-cell-lung tumors treated with SBRT following RTOG-0915 guidelines. Methods: Twenty patients with solitary peripherally located non-small-cell-lung tumors were treated using XVMC-based SBRT to 50–54Gy in 5−3 fractions, respectively, for PTV(V100%)=95%. Based on 4D-CT, ITV was delineated on MaximumIP images and organs-at-risk(OARs) including ribs were contoured on MeanIP images. Mean PTV(ITV+5mm uniform margin) was 46.1±38.7cc (range, 11.1–163.0cc). XVMC SBRT treatment plans were generated with a combination of non-coplanar 3D-conformal arcs/beams, and were delivered by Novalis-TX consisting of HD-MLCs and a 6MV-SRS(1000MU/min) beam, following RTOG-0915 criteria. XVMC rib maximum dose and dosemore » to <1cc, <5cc, <10cc were evaluated as a function of PTV, prescription dose and 3D-distance from tumor isocenter to the most proximal rib contour. Plans were re-computed using heterogeneity-corrected pencil-beam (PB-hete) algorithm utilizing identical beam geometry/MLC positions and MUs and subsequently compared to XVMC. Results: XVMC average maximum rib dose was 50.9±6.4Gy (range, 35.1–59.3Gy). XVMC mean rib dose to <1cc was 41.6±5.6Gy (range, 27.9–47.9Gy), <5cc was 31.2±7.3Gy (range, 10.6–43.1Gy), and <10cc was 21.2±8.7Gy (range, 1.1–36Gy), respectively. For the given prescription, correlation between PTV and rib doses to <5cc (p=0.005) and <10cc (p=0.018) was observed. 3D-distance from the tumor isocenter to the proximal rib contour strongly correlated with maximum rib dose (p=0.0001). PB-hete algorithm overestimated maximum rib dose and dose to <1cc, <5cc, and <10cc of ribs by 5%, 3%, 3%, and 3%, respectively. Conclusion: PB-hete overestimates ribs dose relative to XVMC. Since all the clinical XVMC plans were generated without compromising the target coverage (per RTOG-0915), almost all patient’s ribs doses were higher than the protocol guidelines. As expected, larger tumor size and proximity to ribs received higher absolute dose to ribs. Prospective observation is needed to determine if XVMC delivered rib doses correlates with patient symptoms including chest wall pain and/or rib fractures.« less

Microfluidics and thin-film processes: a recipe for organic integrated photonics based on 3D microresonators

NASA Astrophysics Data System (ADS)

Huby, N.; Pluchon, D.; Belloul, M.; Moreac, A.; Coulon, N.; Gaviot, E.; Panizza, P.; B"che, B.

2010-02-01

We report on the design and realization of photonic integrated devices based on 3D organic microresonators. This has been achieved by combining microfluidics techniques and thin-film processes. The microfluidic device and the control of the flow rates of the continuous and dispersed phases allow the fabrication of organic microresonators with diameter ranging from 30 to 200 μm. The resonance of the sphere in air has been first investigated by using the Raman spectroscopy set-up demonstrating the appropriate photonic properties. Then the microresonators have been integrated on an organic chip made of the photosensitive resin SU-8 and positioned at the extremity of a taper and alongside a rib waveguide. The realization of these structures by thin-film processes needs one step UV-lithography leading to 6μm width and 30μm height. Both devices have proved the efficient evanescent coupling leading to the excitation of the whispering gallery modes confined at the surface of the organic 3D microresonators. Finally, a band-stop filter has been used to detect the resonance spectra of the resonators once integrated.

InGaAsP Mach-Zehnder interferometer optical modulator monolithically integrated with InGaAs driver MOSFET on a III-V CMOS photonics platform.

PubMed

Park, Jin-Kown; Takagi, Shinichi; Takenaka, Mitsuru

2018-02-19

We demonstrated the monolithic integration of a carrier-injection InGaAsP Mach-Zehnder interferometer (MZI) optical modulator and InGaAs metal-oxide-semiconductor field-effect transistor (MOSFET) on a III-V-on-insulator (III-V-OI) wafer. A low-resistivity lateral PIN junction was formed along an InGaAsP rib waveguide by Zn diffusion and Ni-InGaAsP alloy, enabling direct driving of the InGaAsP optical modulator by the InGaAs MOSFET. A π phase shift of the InGaAsP optical modulator was obtained through the injection of a drain current from the InGaAs MOSFET with a gate voltage of approximately 1 V. This proof-of-concept demonstration of the monolithic integration of the InGaAsP optical modulator and InGaAs driver MOSFET will enable us to develop high-performance and low-power electronic-photonic integrated circuits on a III-V CMOS photonics platform.

Testing of stiffening ribs formed by incremental forming in thin-walled aircraft structures made of 2024-T3 ALCLAD aluminium alloy

NASA Astrophysics Data System (ADS)

Kubit, Andrzej; Wydrzynski, Dawid; Bucior, Magdalena; Krasowski, Bogdan

2018-05-01

This paper presents the results of experimental tests on the fabrication of longitudinal stiffening ribs in 2024-T3 ALCLAD aluminum alloy sheet, which is widely used in the aircraft structures. The problem presented in this paper concerns the concept of rib-stiffening of the structure of aircraft skin. The ribs are intended to stiffen integral thin-walled structure. Different shapes and different parameters of the forming process were studied. The rib-stiffened samples of various depths of the ribs were tested experimentally in the buckling test.

Rib fractures: comparison of associated injuries between pediatric and adult population.

PubMed

Kessel, Boris; Dagan, Jasmin; Swaid, Forat; Ashkenazi, Itamar; Olsha, Oded; Peleg, Kobi; Givon, Adi; Alfici, Ricardo

2014-11-01

Rib fractures are considered a marker of exposure to significant traumatic energy. In children, because of high elasticity of the chest wall, higher energy levels are necessary for ribs to fracture. The purpose of this study was to analyze patterns of associated injuries in children as compared with adults, all of whom presented with rib fractures. A retrospective cohort study involving blunt trauma patients with rib fractures registered in the National Trauma Registry was conducted. Of 6,995 trauma victims who were found to suffer from rib fractures, 328 were children and 6,627 were adults. Isolated rib fractures without associated injuries occurred in 19 children (5.8%) and 731 adults (11%). More adults had 4 or more fractured ribs compared with children (P < .001). Children suffered from higher rates of associated brain injuries (P = .003), hemothorax/pneumothorax (P = .006), spleen, and liver injury (P < .001). Mortality rate was 5% in both groups. The incidence of associated head, thoracic, and abdominal solid organ injuries in children was significantly higher than in adults suffering from rib fractures. In spite of a higher Injury Severity Score and incidence of associated injuries, mortality rate was similar. Mortality of rib fracture patients was mostly affected by the presence of extrathoracic injuries. Copyright © 2014 Elsevier Inc. All rights reserved.

Measurement of heat transfer and pressure drop in rectangular channels with turbulence promoters

NASA Technical Reports Server (NTRS)

Han, J. C.; Park, J. S.; Ibrahim, M. Y.

1986-01-01

Periodic rib turbulators were used in advanced turbine cooling designs to enhance the internal heat transfer. The objective of the present project was to investigate the combined effects of the rib angle of attack and the channel aspect ratio on the local heat transfer and pressure drop in rectangular channels with two opposite ribbed walls for Reynolds number varied from 10,000 to 60,000. The channel aspect ratio (W/H) was varied from 1 to 2 to 4. The rib angle of attack (alpha) was varied from 90 to 60 to 45 to 30 degree. The highly detailed heat transfer coefficient distribution on both the smooth side and the ribbed side walls from the channel sharp entrance to the downstream region were measured. The results showed that, in the square channel, the heat transfer for the slant ribs (alpha = 30 -45 deg) was about 30% higher that of the transverse ribs (alpha = 90 deg) for a constant pumping power. However, in the rectangular channels (W/H = 2 and 4, ribs on W side), the heat transfer at alpha = 30 -45 deg was only about 5% higher than 90 deg. The average heat transfer and friction correlations were developed to account for rib spacing, rib angle, and channel aspect ratio over the range of roughness Reynolds number.

Reduction of rib fractures with a bioresorbable plating system: preliminary observations.

PubMed

Vu, Kim-Chi; Skourtis, Mia E; Gong, Xi; Zhou, Minhao; Ozaki, Wayne; Winn, Shelley R

2008-05-01

Operative fixation of rib fractures can reduce morbidity and mortality. Currently, resorbable fixation devices are used in a variety of surgical procedures. A standard osteotomy was prepared in 30 New Zealand white rabbits at the 12th rib. Eighteen had surgical repair with bioresorbable plates and 12 underwent nonoperative management. Half the animals in each group were killed at 3-week postfracture and the remaining animals were killed at 6-week postfracture. Ribs were radiographed and processed histologically to assess fracture healing. Rib reduction was defined as the alignment of the rib ends in a structural condition similar to the prefractured state and quantitative radiomorphometry measured the radiopaque callus surrounding the rib injury sites. Statistical analysis was performed using Fisher's exact test and an unpaired Student's t test and significance was established at p < 0.05. At both the 3- and 6-week intervals, seven of the nine rib fractures remained reduced in the operative group, whereas zero of six and three of six of the rib fractures remained reduced, respectively, in the nonoperative group. A statistically significant increase in radiopaque callus surrounding the rib injury sites was observed at 3 and 6 weeks in the fixed groups. Fixation of rib fractures with a bioresorbable miniplate system was superior to nonoperative treatment at the 3-week interval, with a statistically significant increase in radiopaque callus formation at both 3 and 6 weeks. Additional studies will evaluate the biomechanical outcomes and degradation tissue response after extended in vivo intervals.

Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT.

PubMed

Cho, S H; Sung, Y M; Kim, M S

2012-10-01

The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images.

Hemangioma of the rib showing a relatively high 18F-FDG uptake: a case report with a literature review

PubMed Central

Emori, Makoto; Terashima, Yoshinori; Hasegawa, Tadashi; Shimizu, Junya; Nagoya, Satoshi; Yamashita, Toshihiko

2017-01-01

Hemangioma of the rib is a rare benign tumor that is often difficult to distinguish from malignant bone tumors. Rib hemangioma often shows bony disruption with a slight cortical disruption, extraosseous lesion, and expanded bone on computed tomography (CT). We report the case of a 68-year-old man with atypical rib hemangioma with a slight cortical disruption and no expanded bone. The tumor showed relatively high 18FDG-uptake on positron emission tomography (PET)/CT. Rib hemangioma often shows higher 18FDG-uptake. PET/CT may not provide useful information for distinguishing rib hemangioma from a malignant tumor. Close observation without surgical resection may be feasible if the tumor is diagnosed as a rib hemangioma by biopsy. PMID:28959457

Structural characterization of ribT from Bacillus subtilis reveals it as a GCN5-related N-acetyltransferase.

PubMed

Srivastava, Ritika; Kaur, Amanpreet; Sharma, Charu; Karthikeyan, Subramanian

2018-04-01

In bacteria, biosynthesis of riboflavin occurs through a series of enzymatic steps starting with one molecule of GTP and two molecules of ribulose-5-phosphate. In Bacillus subtilis (B. subtilis) the genes (ribD/G, ribE, ribA, ribH and ribT) which are involved in riboflavin biosynthesis are organized in an operon referred as rib operon. All the genes of rib operon are characterized functionally except for ribT. The ribT gene with unknown function is found at the distal terminal of rib operon and annotated as a putative N-acetyltransferase. Here, we report the crystal structure of ribT from B. subtilis (bribT) complexed with coenzyme A (CoA) at 2.1 Å resolution determined by single wavelength anomalous dispersion method. Our structural study reveals that bribT is a member of GCN5-related N-acetyltransferase (GNAT) superfamily and contains all the four conserved structural motifs that have been in other members of GNAT superfamily. The members of GNAT family transfers the acetyl group from acetyl coenzyme A (AcCoA) to a variety of substrates. Moreover, the structural analysis reveals that the residues Glu-67 and Ser-107 are suitably positioned to act as a catalytic base and catalytic acid respectively suggesting that the catalysis by bribT may follow a direct transfer mechanism. Surprisingly, the mutation of a non-conserved amino acid residue Cys-112 to alanine or serine affected the binding of AcCoA to bribT, indicating a possible role of Cys-112 in the catalysis. Copyright © 2017 Elsevier Inc. All rights reserved.

Rib Cartilage Assessment Relative to the Healthy Ear in Young Children with Microtia Guiding Operative Timing.

PubMed

Kang, Shen-Song; Guo, Ying; Zhang, Dong-Yi; Jiang, Du-Yin

2015-08-20

The optimal age at which to initiate for auricular reconstruction is controversial. Rib cartilage growth is closely related to age and determines the feasibility and outcomes of auricular reconstruction. We developed a method to guide the timing of auricular reconstruction in children with microtia ranging in age from 5 to 10 years. Rib cartilage and the healthy ear were assessed using low-dose multi-slice computed tomography. The lengths of the eighth rib cartilage and the helix of the healthy ear (from the helical crus to the joint of the helix and the earlobe) were measured. Surgery was performed when the two lengths were approximately equal. The preoperative eighth rib measurements significantly correlated with the intraoperative measurements (P < 0.05). From 5 to 10 years of age, eighth rib growth was not linear. In 76 (62.8%) of 121 patients, the eighth rib length was approximately equal to the helix length in the healthy ear; satisfactory outcomes were achieved in these patients. In 18 (14.9%) patients, the eighth rib was slightly shorter than the helix, helix fabrication was accomplished by adjusting the length of the helical crus of stent, and satisfactory outcomes were also achieved. Acceptable outcomes were achieved in 17 (14.0%) patients in whom helix fabrication was accomplished by cartilage splicing. In 9 (7.4%) patients with insufficient rib cartilage length, the operation was delayed. In one (0.8%) patient with insufficient rib cartilage length, which left no cartilage for helix splicing, the result was unsatisfactory. Eighth rib cartilage growth is variable. Rib cartilage assessment relative to the healthy ear can guide auricular reconstruction and personalize treatment in young patients with microtia.

Factors Associated With Chest Wall Toxicity After Accelerated Partial Breast Irradiation Using High-Dose-Rate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Sheree, E-mail: shereedst32@hotmail.com; Vicini, Frank; Vanapalli, Jyotsna R.

2012-07-01

Purpose: The purpose of this analysis was to evaluate dose-volume relationships associated with a higher probability for developing chest wall toxicity (pain) after accelerated partial breast irradiation (APBI) by using both single-lumen and multilumen brachytherapy. Methods and Materials: Rib dose data were available for 89 patients treated with APBI and were correlated with the development of chest wall/rib pain at any point after treatment. Ribs were contoured on computed tomography planning scans, and rib dose-volume histograms (DVH) along with histograms for other structures were constructed. Rib DVH data for all patients were sampled at all volumes {>=}0.008 cubic centimeter (cc)more » (for maximum dose related to pain) and at volumes of 0.5, 1, 2, and 3 cc for analysis. Rib pain was evaluated at each follow-up visit. Patient responses were marked as yes or no. No attempt was made to grade responses. Eighty-nine responses were available for this analysis. Results: Nineteen patients (21.3%) complained of transient chest wall/rib pain at any point in follow-up. Analysis showed a direct correlation between total dose received and volume of rib irradiated with the probability of developing rib/chest wall pain at any point after follow-up. The median maximum dose at volumes {>=}0.008 cc of rib in patients who experienced chest wall pain was 132% of the prescribed dose versus 95% of the prescribed dose in those patients who did not experience pain (p = 0.0035). Conclusions: Although the incidence of chest wall/rib pain is quite low with APBI brachytherapy, attempts should be made to keep the volume of rib irradiated at a minimum and the maximum dose received by the chest wall as low as reasonably achievable.« less

The etiology of pectus carinatum involves overgrowth of costal cartilage and undergrowth of ribs.

PubMed

Park, Chul Hwan; Kim, Tae Hoon; Haam, Seok Jin; Jeon, Inhwan; Lee, Sungsoo

2014-08-01

We compared the length of costal cartilage and rib between patients with symmetric pectus carinatum and controls without anterior chest wall protrusion, using a 3-dimensional (3D) computed tomography (CT) to evaluate whether the overgrowth of costal cartilage exists in patients with pectus carinatum. Twenty-six patients with symmetric pectus carinatum and matched twenty-six controls without chest wall protrusion were enrolled. We measured the full lengths of the 4th-6th ribs and costal cartilages using 3-D volume rendering CT images and the curved multiplanar reformatted (MPR) techniques. The lengths of ribs and costal cartilages, the summation of rib and costal cartilage lengths, and the costal index [length of cartilage/length of rib * 100 (%)] were compared between the patients group and the control group at 4th-6th levels. The lengths of costal cartilage in patient group were significantly longer than those of control group at 4th, 5th and 6th rib level. The lengths of ribs in patient group were significantly shorter than those of control group at 4th, 5th and 6th rib level. The summations of rib and costal cartilage lengths were not longer in patients group than in control group. The costal indices were significantly larger in patients group than in control groups at 4th, 5th and 6th rib level. In patients with symmetric pectus carinatum, the lengths of costal cartilage were longer but the lengths of rib were shorter than those of controls. These findings may supports that the overgrowth of costal cartilage was not the only factor responsible for pectus carinatum. Copyright © 2014 Elsevier Inc. All rights reserved.

A comparison between rib fracture patterns in peri- and post-mortem compressive injury in a piglet model.

PubMed

Bradley, Amanda L; Swain, Michael V; Neil Waddell, J; Das, Raj; Athens, Josie; Kieser, Jules A

2014-05-01

Forensic biomechanics is increasingly being used to explain how observed injuries occur. We studied infant rib fractures from a biomechanical and morphological perspective using a porcine model. We used 24, 6th ribs of one day old domestic pigs Sus scrofa, divided into three groups, desiccated (representing post-mortem trauma), fresh ribs with intact periosteum (representing peri-mortem trauma) and those stored at -20°C. Two experiments were designed to study their biomechanical behaviour fracture morphology: ribs were axially compressed and subjected to four-point bending in an Instron 3339 fitted with custom jigs. Morphoscopic analysis of resultant fractures consisted of standard optical methods, micro-CT (μCT) and Scanning Electron Microscopy (SEM). During axial compression fresh ribs did not fracture because of energy absorption capabilities of their soft and fluidic components. In flexure tests, dry ribs showed typical elastic-brittle behaviour with long linear load-extension curves, followed by short non-linear elastic (hyperelastic) behaviour and brittle fracture. Fresh ribs showed initial linear-elastic behaviour, followed by strain softening and visco-plastic responses. During the course of loading, dry bone showed minimal observable damage prior to the onset of unstable fracture. Frozen then thawed bone showed similar patterns to fresh bone. Morphologically, fresh ribs showed extensive periosteal damage to the tensile surface with areas of collagen fibre pull-out along the tensile surface. While all dry ribs fractured precipitously, with associated fibre pull-out, the latter feature was absent in thawed ribs. Our study highlights the fact that under controlled loading, fresh piglet ribs (representing perimortem trauma) did not fracture through bone, but was associated with periosteal tearing. These results suggest firstly, that complete lateral rib fracture in infants may in fact not result from pure compression as has been previously assumed; and secondly, that freezing of bone during storage may affect its fracture behaviour. Copyright © 2013 Elsevier Ltd. All rights reserved.

Analysis of bone healing in flail chest injury: do we need to fix both fractures per rib?

PubMed

Marasco, Silvana; Liew, Susan; Edwards, Elton; Varma, Dinesh; Summerhayes, Robyn

2014-09-01

Surgical rib fixation (SRF) for severe rib fracture injuries is generating increasing interest in the medical literature. It is well documented that poorly healed fractured ribs can lead to chronic pain, disability, and deformity. An unanswered question in SRF for flail chest injury is whether it is sufficient to fix one fracture per rib, on successive ribs, thus converting a flail chest injury into simple fractured ribs, or whether both ends of the floating segment of the chest wall should be fixed. This study aimed to analyze SRF in flail chest injury, assessing 3-month outcomes for nonfixed fractured rib ends in the flail segment. This is a retrospective review (2005-2013) of 60 consecutive patients who underwent SRF for flail chest injury admitted to the Alfred Hospital, Melbourne, Australia. Imaging by three-dimensional computed tomography (3D CT) of the chest at admission was compared with follow-up 3D CT at 3 months after injury. The 3-month CT scans were assessed for degree of healing and presence of residual deformity at the fracture fixation site. Follow-up CT was performed in 52 of the 60 patients. At 3 months after surgery, 86.5% of the patients had at least partial healing with good alignment and adequate fracture stabilization. Hardware failure was noted in five patients (9.6%) and occurred with the absorbable prostheses only. Six patients who had preoperative overlapping or displacement showed no improvement in deformity despite fixing the lateral fractures. Callus formation and bony bridging between adjacent ribs was often noted in the rib fractures not fixed (28 of 52 patients, 54%) This retrospective review of 3D CT chest at 3 months after rib fixation indicates that a philosophy of fixing only one fracture per rib in a flail segment does not avoid deformity and displacement, particularly in posterior rib fractures. Therapeutic study, level V; epidemiologic study, level V.

WRAP-RIB antenna technology development

NASA Technical Reports Server (NTRS)

Freeland, R. E.; Garcia, N. F.; Iwamoto, H.

1985-01-01

The wrap-rib deployable antenna concept development is based on a combination of hardware development and testing along with extensive supporting analysis. The proof-of-concept hardware models are large in size so they will address the same basic problems associated with the design fabrication, assembly and test as the full-scale systems which were selected to be 100 meters at the beginning of the program. The hardware evaluation program consists of functional performance tests, design verification tests and analytical model verification tests. Functional testing consists of kinematic deployment, mesh management and verification of mechanical packaging efficiencies. Design verification consists of rib contour precision measurement, rib cross-section variation evaluation, rib materials characterizations and manufacturing imperfections assessment. Analytical model verification and refinement include mesh stiffness measurement, rib static and dynamic testing, mass measurement, and rib cross-section characterization. This concept was considered for a number of potential applications that include mobile communications, VLBI, and aircraft surveillance. In fact, baseline system configurations were developed by JPL, using the appropriate wrap-rib antenna, for all three classes of applications.

The contribution of rib fractures to chronic pain and disability.

PubMed

Gordy, Stephanie; Fabricant, Loic; Ham, Bruce; Mullins, Richard; Mayberry, John

2014-05-01

The contribution of rib fractures to chronic pain and disability is not well described. Two hundred three patients with rib fractures were followed for 6 months. Chronic pain was assessed using the McGill Pain Questionnaire Pain Rating Index and Present Pain Intensity (PPI) scales. Disability was defined as a decrease in work or functional status. The prevalence of chronic pain was 22% and disability was 53%. Acute PPI predicted chronic pain. Associated injuries, bilateral rib fractures, injury severity score, and number of rib fractures were not predictive of chronic pain. No acute injury characteristics were predictive of disability. Among 89 patients with isolated rib fractures, the prevalence of chronic pain was 28% and of disability was 40%. No injury characteristics predicted chronic pain. Bilateral rib fractures and acute PPI predicted disability. The contribution of rib fractures to chronic pain and disability is significant but unpredictable with conventional injury descriptors. Copyright © 2014 Elsevier Inc. All rights reserved.

Compressive rib fracture: peri-mortem and post-mortem trauma patterns in a pig model.

PubMed

Kieser, Jules A; Weller, Sarah; Swain, Michael V; Neil Waddell, J; Das, Raj

2013-07-01

Despite numerous studies on high impact fractures of ribs, little is known about compressive rib injuries. We studied rib fractures from a biomechanical and morphological perspective using 15, 5th ribs of domestic pigs Sus scrofa, divided into two groups, desiccated (representing post-mortem trauma) and fresh ribs with intact periosteum (representing peri-mortem trauma). Ribs were axially compressed and subjected to four-point bending in an Instron 3339 fitted with custom jigs. Morphoscopic analysis of resultant fractures consisted of standard optical methods, micro-CT (μCT) and scanning electron microscopy (SEM). During axial compression, fresh ribs had slightly higher strength because of energy absorption capabilities of their soft and fluidic components. In flexure tests, dry ribs showed typical elastic-brittle behaviour with long linear load-extension curves, followed by relatively short non-linear elastic (hyperelastic) behaviour and brittle fracture. Fresh ribs showed initial linear-elastic behaviour, followed by strain softening, visco-plastic responses. During the course of loading, dry bone showed minimal observable damage prior to the onset of unstable fracture. In contrast, fresh bone showed buckling-like damage features on the compressive surface and cracking parallel to the axis of the bone. Morphologically, all dry ribs fractured precipitously, whereas all but one of the fresh ribs showed incomplete fracture. The mode of fracture, however, was remarkably similar for both groups, with butterfly fractures predominating (7/15, 46.6% dry and wet). Our study highlights the fact that under controlled loading, despite seemingly similar butterfly fracture morphology, fresh ribs (representing perimortem trauma) show a non-catastrophic response. While extensive strain softening observed for the fresh bone does show some additional micro-cracking damage, it appears that the periosteum may play a key role in imparting the observed pseudo-ductility to the ribs. The presence of fibrous pull-out and grooving of the outer tensile surface associated with periosteal stretching suggests that the periosteum under tension is able to sustain very high strain and bridge the mouth of the extending butterfly crack, thereby contributing to the observed strain-softening behaviour. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Rib plating of acute and sub-acute non-union rib fractures in an adult with cystic fibrosis: a case report.

PubMed

Dean, Nathan C; Van Boerum, Don H; Liou, Theodore G

2014-10-01

Rib fractures associated with osteoporosis have been reported to occur ten times more frequently in adults with cystic fibrosis. Fractures cause chest pain, and interfere with cough and sputum clearance leading to worsened lung function and acute exacerbations which are the two main contributors to early mortality in cystic fibrosis. Usual treatment involves analgesics and time for healing; however considerable pain and disability result due to constant re-injury from chronic repetitive cough. Recently, surgical plating of rib fractures has become commonplace in treating acute, traumatic chest injuries. We describe here successful surgical plating in a White cystic fibrosis patient with multiple, non-traumatic rib fractures. A-37-year old White male with cystic fibrosis was readmitted to Intermountain Medical Center for a pulmonary exacerbation. He had developed localized rib pain while coughing 2 months earlier, with worsening just prior to hospital admission in conjunction with a "pop" in the same location while bending over. A chest computerized tomography scan at admission demonstrated an acute 5th rib fracture and chronic non-united 6th and 7th right rib fractures. An epidural catheter was placed both for analgesia and to make secretion clearance possible in preparation for the surgery performed 2 days later. Under general anesthesia, he had open reduction and internal fixation of the right 5th, 6th and 7th rib fractures with a Synthes Matrix rib set. After several days of increased oxygen requirements, fever, fluid retention, and borderline vital signs, he stabilized. Numerical pain rating scores from his ribs were lower post-operatively and he was able to tolerate chest physical therapy and vigorous coughing. In our case report, rib plating with bone grafting improved rib pain and allowed healing of the fractures and recovery, although the immediate post-op period required close attention and care. We believe repair may be of benefit in selected cystic fibrosis patients, such as our patient who had suffered multiple rib fractures that were healing poorly.

Fixation of a human rib by an intramedullary telescoping splint anchored by bone cement.

PubMed

Liovic, Petar; Šutalo, Ilija D; Marasco, Silvana F

2016-09-01

A novel concept for rib fixation is presented that involves the use of a bioresorbable polymer intramedullary telescoping splint. Bone cement is used to anchor each end of the splint inside the medullary canal on each side of the fracture site. In this manner, rib fixation is achieved without fixation device protrusion from the rib, making the splint completely intramedullary. Finite element analysis is used to demonstrate that such a splint/cement composite can preserve rib fixation subjected to cough-intensity force loadings. Computational fluid dynamics and porcine rib experiments were used to study the anchor formation process required to complete the fixation.

Delayed massive hemothorax complicating simple rib fracture associated with diaphragmatic injury.

PubMed

Chen, Chin-Li; Cheng, Yeung-Leung

2014-07-01

Traumatic hemothorax is potentially life threatening. Rib fractures are the commonest injury after chest trauma, which accounts for 10% of patients after trauma. A delayed massive hemothorax after simple rib fracture is rare. The possibility of delayed sequelae after chest trauma should be considered, and patients should be informed of this possibility. We present a case of this uncommon situation with delayed massive hemothorax caused by simple fracture of the lower ribs. Admission should be considered for close observation when presenting with fracture of the lower ribs because of the possibility of diaphragmatic injury or intra-abdominal injury, even if a simple rib fracture is found initially.

A statistical human rib cage geometry model accounting for variations by age, sex, stature and body mass index.

PubMed

Shi, Xiangnan; Cao, Libo; Reed, Matthew P; Rupp, Jonathan D; Hoff, Carrie N; Hu, Jingwen

2014-07-18

In this study, we developed a statistical rib cage geometry model accounting for variations by age, sex, stature and body mass index (BMI). Thorax CT scans were obtained from 89 subjects approximately evenly distributed among 8 age groups and both sexes. Threshold-based CT image segmentation was performed to extract the rib geometries, and a total of 464 landmarks on the left side of each subject׳s ribcage were collected to describe the size and shape of the rib cage as well as the cross-sectional geometry of each rib. Principal component analysis and multivariate regression analysis were conducted to predict rib cage geometry as a function of age, sex, stature, and BMI, all of which showed strong effects on rib cage geometry. Except for BMI, all parameters also showed significant effects on rib cross-sectional area using a linear mixed model. This statistical rib cage geometry model can serve as a geometric basis for developing a parametric human thorax finite element model for quantifying effects from different human attributes on thoracic injury risks. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surgical Management of Rib Fractures: Strategies and Literature Review.

PubMed

de Jong, M B; Kokke, M C; Hietbrink, F; Leenen, L P H

2014-06-01

Rib fractures can cause significant problems in trauma patients, often resulting in pain and difficulty with respiration. To prevent pulmonary complications and decrease the morbidity and mortality rates of patients with rib fractures, currently there is a trend to provide surgical management of patients with flail chest. However, the indications for rib fracture fixation require further specification. Past and current strategies are described according to a review of the medical literature. A systematic review was performed including current indications for rib fracture fixation. MEDLINE (2000-2013) was searched, as well as Embase (2000-2013) and Cochrane Databases, using the keywords rib, fracture, fixation, plate, repair, and surgery. Three retrospective studies were found that described different techniques for rib fracture fixation. The results demonstrated a reduced number of ventilation days, decreased long-term morbidity and pain, and satisfactory rehabilitation after surgical treatment. In addition to flail chest, age, Injury Severity Score, and the number of rib fractures were important predictive factors for morbidity and mortality. Surgical rib fracture fixation might be indicated in a broader range of cases than is currently performed. Prospective randomized trials are needed for further confirmation. © The Finnish Surgical Society 2014.

Surgical Stabilization of Rib Fractures in a 6-Year-Old Child After Blunt Trauma.

PubMed

Abdelsattar, Zaid M; Ishitani, Michael B; Kim, Brian D

2017-12-01

When identified, rib fractures in children are associated with high-energy trauma, nonaccidental trauma, or both. Traditionally, the optimal management of rib fractures in children is supportive care. In this case report, we present a 6-year-old boy who underwent surgical rib fixation for multiple displaced and comminuted rib fractures after being stepped on by a horse. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Detection and labeling ribs on expiration chest radiographs

NASA Astrophysics Data System (ADS)

Park, Mira; Jin, Jesse S.; Wilson, Laurence S.

2003-06-01

Typically, inspiration is preferred when xraying the lungs. The x-ray technologist will ask a patient to be still and to take a deep breath and to hold it. This not only reduces the possibility of a blurred image but also enhances the quality of the image since air-filled lungs are easier to see on x-ray film. However, inspiration causes low density in the inner part of lung field. That means that ribs in the inner part of lung field have lower density than the other parts nearer to the border of the lung field. That is why edge detection algorithms often fail to detect ribs. Therefore to make rib edges clear we try to produce an expiration lung field using a 'hemi-elliptical cavity.' Based on the expiration lung field, we extract the rib edges using canny edge detector and a new connectivity method, called '4 way with 10-neighbors connectivity' to detect clavicle and rib edge candidates. Once the edge candidates are formed, our system selects the best candidates using knowledge-based constraints such as a gradient, length and location. The edges can be paired and labeled as superior rib edge and inferior rib edge. Then the system uses the clavicle, which is obtained in a same method for the rib edge detection, as a landmark to label all detected ribs.

Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT

PubMed Central

Cho, S H; Sung, Y M; Kim, M S

2012-01-01

Objective The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. Methods 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. Results 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Conclusion Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images. PMID:22514102

Induced chirality of cage metal complexes switched by their supramolecular and covalent binding.

PubMed

Kovalska, Vladyslava B; Vakarov, Serhii V; Kuperman, Marina V; Losytskyy, Mykhaylo Y; Gumienna-Kontecka, Elzbieta; Voloshin, Yan Z; Varzatskii, Oleg A

2018-01-23

An ability of the ribbed-functionalized iron(ii) clathrochelates to induce a CD output in interactions with a protein, covalent bonding or supramolecular interactions with a low-molecular-weight chiral inductor, was discovered. The interactions of CD inactive, carboxyl-terminated iron(ii) clathrochelates with serum albumin induced their molecular asymmetry, causing an appearance of strong CD signals in the range of 350-600 nm, whereas methyl ester and amide clathrochelate derivatives remained almost CD inactive. The CD spectra of carboxyl-terminated clathrochelates on supramolecular interactions or covalent bonding with (R)-(+)-1-phenylethylamine gave a substantially lower CD output than with albumin, affected by both the solvent polarity and the isomerism of clathrochelate's ribbed substituents. In supramolecular assemblies, the bands were most intensive for ortho-substituted carboxyl-terminated clathrochelates. The ortho- and meta-phenylethylamide cage complexes in tetrachloromethane inverted the signs of their CD bands compared with those in acetonitrile. It was suggested that the tris-dioximate metal clathrochelates possess a Russian doll-like molecular system. Because of the distorted TP-TAP geometry, their coordination polyhedron had no inversion centre and possessed an inherent chirality together with the equiprobability of its left(Λ)- and right(Δ)-handle twists. The selective fixation of one of these C 3 -distorted conformations resulted in the appearance of the CD signal in the range of their visible metal-to-ligand charge transfer bands. Calculations by DFT methods were used to illustrate the possible conformations of the macrobicyclic molecules, as well as the intramolecular interactions between the cage framework and optically active distal substituents responsible for the chirality induction of the metal-centred coordination polyhedra.

Photonic crystal based biosensor for the detection of glucose concentration in urine

NASA Astrophysics Data System (ADS)

Robinson, Savarimuthu; Dhanlaksmi, Nagaraj

2017-03-01

Photonic sensing technology is a new and accurate measurement technology for bio-sensing applications. In this paper, a two-dimensional photonic crystal ring resonator based sensor is proposed and designed to detect the glucose concentration in urine over the range of 0 gm/dl-15 gm/dl. The proposed sensor is consisted of two inverted "L" waveguides and a ring resonator. If the glucose concentration in urine is varied, the refractive index of the urine is varied, which in turn the output response of sensor will be varied. By having the aforementioned principle, the glucose concentration in urine, glucose concentration in blood, albumin, urea, and bilirubin concentration in urine are predicted. The size of the proposed sensor is about 11.4 µm×11.4 µm, and the sensor can predict the result very accurately without any delay, hence, this attempt could be implemented for medical applications.

Photonic mesophases from cut rod rotators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stelson, Angela C.; Liddell Watson, Chekesha M., E-mail: cml66@cornell.edu; Avendano, Carlos

2016-01-14

The photonic band properties of random rotator mesophases are calculated using supercell methods applied to cut rods on a hexagonal lattice. Inspired by the thermodynamic mesophase for anisotropic building blocks, we vary the shape factor of cut fraction for the randomly oriented basis. We find large, stable bandgaps with high gap isotropy in the inverted and direct structures as a function of cut fraction, dielectric contrast, and filling fraction. Bandgap sizes up to 34.5% are maximized at high dielectric contrast for rods separated in a matrix. The bandgaps open at dielectric contrasts as low as 2.0 for the transverse magneticmore » polarization and 2.25 for the transverse electric polarization. Additionally, the type of scattering that promotes the bandgap is correlated with the effect of disorder on bandgap size. Slow light properties are investigated in waveguide geometry and slowdown factors up to 5 × 10{sup 4} are found.« less

Computational Investigations in Rectangular Convergent and Divergent Ribbed Channels

NASA Astrophysics Data System (ADS)

Sivakumar, Karthikeyan; Kulasekharan, N.; Natarajan, E.

2018-05-01

Computational investigations on the rib turbulated flow inside a convergent and divergent rectangular channel with square ribs of different rib heights and different Reynolds numbers (Re=20,000, 40,000 and 60,000). The ribs were arranged in a staggered fashion between the upper and lower surfaces of the test section. Computational investigations are carried out using computational fluid dynamic software ANSYS Fluent 14.0. Suitable solver settings like turbulence models were identified from the literature and the boundary conditions for the simulations on a solution of independent grid. Computations were carried out for both convergent and divergent channels with 0 (smooth duct), 1.5, 3, 6, 9 and 12 mm rib heights, to identify the ribbed channel with optimal performance, assessed using a thermo hydraulic performance parameter. The convergent and divergent rectangular channels show higher Nu values than the standard correlation values.

Preliminary study of rib articulated model based on dynamic fluoroscopy images

NASA Astrophysics Data System (ADS)

Villard, Pierre-Frederic; Escamilla, Pierre; Kerrien, Erwan; Gorges, Sebastien; Trousset, Yves; Berger, Marie-Odile

2014-03-01

We present in this paper a preliminary study of rib motion tracking during Interventional Radiology (IR) fluoroscopy guided procedures. It consists in providing a physician with moving rib three-dimensional (3D) models projected in the fluoroscopy plane during a treatment. The strategy is to help to quickly recognize the target and the no-go areas i.e. the tumor and the organs to avoid. The method consists in i) elaborating a kinematic model of each rib from a preoperative computerized tomography (CT) scan, ii) processing the on-line fluoroscopy image and iii) optimizing the parameters of the kinematic law such as the transformed 3D rib projected on the medical image plane fit well with the previously processed image. The results show a visually good rib tracking that has been quantitatively validated by showing a periodic motion as well as a good synchronism between ribs.

Physical mechanisms of active control of sound transmission through rib stiffened double-panel structure

NASA Astrophysics Data System (ADS)

Ma, Xiyue; Chen, Kean; Ding, Shaohu; Yu, Haoxin

2016-06-01

This paper presents an analytical investigation on physical mechanisms of actively controlling sound transmission through a rib stiffened double-panel structure using point source in the cavity. The combined modal expansion and vibro-acoustic coupling methods are applied to establish the theoretical model of such active structure. Under the condition of minimizing radiated power of the radiating ribbed plate, the physical mechanisms are interpreted in detail from the point of view of modal couplings similar as that used in existed literatures. Results obtained demonstrate that the rule of sound energy transmission and the physical mechanisms for the rib stiffened double-panel structure are all changed, and affected by the coupling effects of the rib when compared with the analytical results obtained for unribbed double-panel case. By taking the coupling effects of the rib into considerations, the cavity modal suppression and rearrangement mechanisms obtained in existed investigations are modified and supplemented for the ribbed plate case, which gives a clear interpretation for the physical nature involved in the active rib stiffened double-panel structure.

What Accounts for Rib Fractures in Older Adults?

PubMed Central

Wuermser, Lisa-Ann; Achenbach, Sara J.; Amin, Shreyasee; Khosla, Sundeep; Melton, L. Joseph

2011-01-01

To address the epidemiology of rib fractures, an age- and sex-stratified random sample of 699 Rochester, Minnesota, adults age 21–93 years was followed in a long-term prospective study. Bone mineral density (BMD) was assessed at baseline, and fractures were ascertained by periodic interview and medical record review. During 8560 person-years of followup (median, 13.9 years), 56 subjects experienced 67 rib fracture episodes. Risk factors for falling predicted rib fractures as well as BMD, but both were strongly age-related. After age-adjustment, BMD was associated with rib fractures in women but not men. Importantly, rib fractures attributed to severe trauma were associated with BMD in older individuals of both sexes. Self-reported heavy alcohol use doubled fracture risk but did not achieve significance due to limited statistical power. Bone density, along with heavy alcohol use and other risk factors for falling, contributes to the risk of rib fractures, but no one factor predominates. Older women with rib fractures, regardless of cause, should be considered for an osteoporosis evaluation, and strategies to prevent falling should be considered in both sexes. PMID:22028986

What accounts for rib fractures in older adults?

PubMed

Wuermser, Lisa-Ann; Achenbach, Sara J; Amin, Shreyasee; Khosla, Sundeep; Melton, L Joseph

2011-01-01

To address the epidemiology of rib fractures, an age- and sex-stratified random sample of 699 Rochester, Minnesota, adults age 21-93 years was followed in a long-term prospective study. Bone mineral density (BMD) was assessed at baseline, and fractures were ascertained by periodic interview and medical record review. During 8560 person-years of followup (median, 13.9 years), 56 subjects experienced 67 rib fracture episodes. Risk factors for falling predicted rib fractures as well as BMD, but both were strongly age-related. After age-adjustment, BMD was associated with rib fractures in women but not men. Importantly, rib fractures attributed to severe trauma were associated with BMD in older individuals of both sexes. Self-reported heavy alcohol use doubled fracture risk but did not achieve significance due to limited statistical power. Bone density, along with heavy alcohol use and other risk factors for falling, contributes to the risk of rib fractures, but no one factor predominates. Older women with rib fractures, regardless of cause, should be considered for an osteoporosis evaluation, and strategies to prevent falling should be considered in both sexes.

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

PubMed

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.

Rib fractures after percutaneous radiofrequency and microwave ablation of lung tumors: incidence and relevance.

PubMed

Alexander, Erica S; Hankins, Carol A; Machan, Jason T; Healey, Terrance T; Dupuy, Damian E

2013-03-01

To retrospectively identify the incidence and probable risk factors for rib fractures after percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) of neoplasms in the lung and to identify complications related to these fractures. Institutional review board approval was obtained for this HIPAA-compliant retrospective study. Study population was 163 patients treated with MWA and/or RFA for 195 lung neoplasms between February 2004 and April 2010. Follow-up computed tomographic images of at least 3 months were retrospectively reviewed by board-certified radiologists to determine the presence of rib fractures. Generalized estimating equations were performed to assess the effect that patient demographics, tumor characteristics, treatment parameters, and ablation zone characteristics had on development of rib fractures. Kaplan-Meier curve was used to estimate patients' probability of rib fracture after ablation as a function of time. Clinical parameters (ie, pain in ribs or chest, organ damage caused by fractured rib) were evaluated for patients with confirmed fracture. Rib fractures in proximity to the ablation zone were found in 13.5% (22 of 163) of patients. Estimated probability of fracture was 9% at 1 year and 22% at 3 years. Women were more likely than were men to develop fracture after ablation (P = .041). Patients with tumors closer to the chest wall were more likely to develop fracture (P = .0009), as were patients with ablation zones that involved visceral pleura (P = .039). No patients with rib fractures that were apparently induced by RFA and MWA had organ injury or damage related to fracture, and 9.1% (2 of 22) of patients reported mild pain. Rib fractures were present in 13.5% of patients after percutaneous RFA and MWA of lung neoplasms. Patients who had ablations performed close to the chest wall should be monitored for rib fractures.

Dyspnea, chest wall hyperinflation, and rib cage distortion in exercising patients with chronic obstructive pulmonary disease.

PubMed

Bruni, Giulia Innocenti; Gigliotti, Francesco; Binazzi, Barbara; Romagnoli, Isabella; Duranti, Roberto; Scano, Giorgio

2012-06-01

Whether dyspnea, chest wall dynamic hyperinflation, and abnormalities of rib cage motion are interrelated phenomena has not been systematically evaluated in patients with chronic obstructive pulmonary disease (COPD). Our hypothesis that they are not interrelated was based on the following observations: (i) externally imposed expiratory flow limitation is associated with no rib cage distortion during strenuous incremental exercise, with indexes of hyperinflation not being correlated with dyspnea, and (ii) end-expiratory chest wall volume may either increase or decrease during exercise in patients with COPD, with those who hyperinflate being as breathless as those who do not. Sixteen patients breathed either room air or 50% supplemental O2 at 75% of peak exercise in randomized order. We evaluated the volume of chest wall (V(cw)) and its compartments: the upper rib cage (V(rcp)), lower rib cage (V(rca)), and abdomen (V(ab)) using optoelectronic plethysmography; rib cage distortion was assessed by measuring the phase angle shift between V(rcp) and V(rca). Ten patients increased end-expiratory V(cw) (V(cw,ee)) on air. In seven hyperinflators and three non-hyperinflators, the lower rib cage paradoxed inward during inspiration with a phase angle of 63.4° ± 30.7° compared with a normal phase angle of 16.1° ± 2.3° recorded in patients without rib cage distortion. Dyspnea (by Borg scale) averaged 8.2 and 9 at the end of exercise on air in patients with and without rib cage distortion, respectively. At iso-time during exercise with oxygen, decreased dyspnea was associated with a decrease in ventilation regardless of whether patients distorted the rib cage, dynamically hyperinflated, or deflated the chest wall. Dyspnea, chest wall dynamic hyperinflation, and rib cage distortion are not interrelated phenomena.

Focusing of high intensity ultrasound through the rib cage using a therapeutic random phased array

PubMed Central

Bobkova, Svetlana; Gavrilov, Leonid; Khokhlova, Vera; Shaw, Adam; Hand, Jeffrey; #, ||

2010-01-01

A method for focusing high intensity ultrasound through a rib cage that aims to minimize heating of the ribs whilst maintaining high intensities at the focus (or foci) is proposed and tested theoretically and experimentally. Two approaches, one based on geometric acoustics and the other accounting for diffraction effects associated with propagation through the rib cage, are investigated theoretically for idealized source conditions. It is shown that for an idealized radiator the diffraction approach provides a 23% gain in peak intensity and results in significantly less power losses on the ribs (1% versus 7.5% of the irradiated power) compared with the geometric one. A 2D 1-MHz phased array with 254 randomly distributed elements, tissue mimicking phantoms, and samples of porcine rib cages are used in experiments; the geometric approach is used to configure how the array is driven. Intensity distributions are measured in the plane of the ribs and in the focal plane using an infra-red camera. Theoretical and experimental results show that it is possible to provide adequate focusing through the ribs without overheating them for a single focus and several foci, including steering at ± 10–15 mm off and ± 20 mm along the array axis. Focus splitting due to the periodic spatial structure of ribs is demonstrated both in simulations and experiments; the parameters of splitting are quantified. The ability to produce thermal lesions with a split focal pattern in ex vivo porcine tissue placed beyond the rib phantom is also demonstrated. The results suggest that the method is potentially useful for clinical applications of HIFU for which the rib cage lies between the transducer(s) and the targeted tissue. PMID:20510186

Osteoblastic lesion screening with an advanced post-processing package enabling in-plane rib reading in CT-images.

PubMed

Seuss, Hannes; Dankerl, Peter; Cavallaro, Alexander; Uder, Michael; Hammon, Matthias

2016-05-20

To evaluate screening and diagnostic accuracy for the detection of osteoblastic rib lesions using an advanced post-processing package enabling in-plane rib reading in CT-images. We retrospectively assessed the CT-data of 60 consecutive prostate cancer patients by applying dedicated software enabling in-plane rib reading. Reading the conventional multiplanar reconstructions was considered to be the reference standard. To simulate clinical practice, the reader was given 10 s to screen for sclerotic rib lesions in each patient applying both approaches. Afterwards, every rib was evaluated individually with both approaches without a time limit. Sensitivities, specificities, positive/negative predictive values and the time needed for detection were calculated depending on the lesion's size (largest diameter < 5 mm, 5-10 mm, > 10 mm). In 53 of 60 patients, all ribs were properly displayed in plane, in five patients ribs were partially displayed correctly, and in two patients none of the ribs were displayed correctly. During the 10-s screening approach all patients with sclerotic rib lesions were correctly identified reading the in-plane images (including the patients without a correct rib segmentation), whereas 14 of 23 patients were correctly identified reading conventional multiplanar images. Overall screening sensitivity, specificity, and positive/negative predictive values were 100/27.0/46.0/100 %, respectively, for in-plane reading and 60.9/100/100/80.4 %, respectively, for multiplanar reading. Overall diagnostic (no time limit) sensitivity, specificity, and positive/negative predictive values of in-plane reading were 97.8/92.8/74.6/99.5 %, respectively. False positive results predominantly occurred for lesions <5 mm in size. In-plane reading of the ribs allows reliable detection of osteoblastic lesions for screening purposes. The limited specificity results from false positives predominantly occurring for small lesions.

Trauma patient adverse outcomes are independently associated with rib cage fracture burden and severity of lung, head, and abdominal injuries.

PubMed

Dunham, C Michael; Hileman, Barbara M; Ransom, Kenneth J; Malik, Rema J

2015-01-01

We hypothesized that lung injury and rib cage fracture quantification would be associated with adverse outcomes. Consecutive admissions to a trauma center with Injury Severity Score ≥ 9, age 18-75, and blunt trauma. CT scans were reviewed to score rib and sternal fractures and lung infiltrates. Sternum and each anterior, lateral, and posterior rib fracture was scored 1 = non-displaced and 2 = displaced. Rib cage fracture score (RCFS) = total rib fracture score + sternal fracture score + thoracic spine Abbreviated Injury Score (AIS). Four lung regions (right upper/middle, right lower, left upper, and left lower lobes) were each scored for % of infiltrate: 0% = 0; ≤ 20% = 1, ≤ 50% = 2, > 50% = 3; total of 4 scores = lung infiltrate score (LIS). Of 599 patients, 193 (32%) had 854 rib fractures. Rib fracture patients had more abdominal injuries (p < 0.001), hemo/pneumothorax (p < 0.001), lung infiltrates (p < 0.001), thoracic spine injuries (p = 0.001), sternal fractures (p = 0.0028) and death or need for mechanical ventilation ≥ 3 days (Death/Vdays ≥ 3) (p < 0.001). Death/Vdays ≥ 3 was independently associated with RCFS (p < 0.001), LIS (p < 0.001), head AIS (p < 0.001) and abdominal AIS (p < 0.001). Of the 193 rib fracture patients, Glasgow Coma Score 3-12 or head AIS ≥ 2 occurred in 43%. A lung infiltrate or hemo/pneumothorax occurred in 55%. Thoracic spine injury occurred in 23%. RCFS was 6.3 ± 4.4 and Death/Vdays ≥ 3 occurred in 31%. Death/Vdays ≥ 3 rates correlated with RCFS values: 19% for 1-3; 24% for 4-6; 42% for 7-12 and 65% for ≥ 13 (p < 0.001). Death/Vdays ≥ 3 was independently associated with RCFS (p = 0.02), LIS (p = 0.001), head AIS (p < 0.001) and abdominal AIS (p < 0.001). Death/Vdays ≥ 3 association was better for RCFS (p = 0.005) than rib fracture score (p = 0.08) or number of fractured ribs (p = 0.80). Rib fracture patients have increased risk for truncal injuries and adverse outcomes. Adverse outcomes are independently associated with rib cage fracture burden. Severity of head, abdominal, and lung injuries also influence rib fracture outcomes.

Turbine bucket natural frequency tuning rib

DOEpatents

Wang, John Zhiqiang; Norton, Paul Francis; Barb, Kevin Joseph; Jacala, Ariel Caesar-Prepena

2002-01-01

A tuning rib is added preferably in the aft cavity of a cored turbine bucket to alter the bucket's natural frequencies. The tuning rib may be a solid rib or a segmented rib and is particularly suited for altering high order frequency modes such as 2T, 4F and 1-3S. As such, detrimental crossings of natural bucket frequencies and gas turbine stimuli can be avoided to thereby improve the reliability of a gas turbine without impacting other features of the bucket that are important to the performance of the gas turbine.

Rib fracture - aftercare

MedlinePlus

... Alternative Names Broken rib - aftercare References Browner BD, Jupiter JB, Krettek C, Anderson PA. Scapula and rib fractures. In: Browner BD, Jupiter JB, Krettek C, Anderson PA, eds. Skeletal Trauma: ...

Waveguide arrangements based on adiabatic elimination

DOEpatents

Suchowski, Haim; Mrejen, Michael; Wu, Chihhui; Zhang, Xiang

2016-09-13

This disclosure provides systems, methods, and apparatus related to nanophotonics. In one aspect, an arrangement of waveguides includes a substrate and three waveguides. Each of the three waveguides may be a linear waveguide. A second waveguide is positioned between a first waveguide and a third waveguide. The dimensions and positions of the first, the second, and the third waveguides are specified to substantially eliminate coupling between the first waveguide and the third waveguide over a distance of about 1 millimeter to 2 millimeters along lengths of the first waveguide, the second waveguide, and the third waveguide.

Use of the Animal Trauma Triage Score, RibScore, Modified RibScore and Other Clinical Factors for Prognostication in Canine Rib Fractures.

PubMed

McCarthy, Daniel; Bacek, Lenore; Kim, Kyoung; Miller, George; Gaillard, Philippe; Kuo, Kendon

2018-06-11

 To characterize the clinical features among dogs sustaining rib fractures and to determine if age, type and severity of injury, entry blood lactate, trauma score and rib fracture score were associated with outcome.  A retrospective study was performed to include dogs that were presented with rib fractures. Risk factors evaluation included breed, age, body weight, diagnosis, presence of a flail chest, bandage use, puncture wound presence, rib fracture number, location of the fracture along the thoracic wall, hospital stay length, body weight, other fractures, pleural effusion, pulmonary contusions, pneumothorax and occurrence of an anaesthetic event. A retrospective calculation of an animal trauma triage (ATT) score, RibScore and Modified RibScore was assigned.  Forty-one medical records were collected. Motor vehicular trauma represented 56% of the rib fracture aetiology, 41% of patients sustained dog bites and one case was of an unknown aetiology. Significant correlations with risk factors were found only with the ATT score. All patients that died had an ATT score ≥ 5. The ATT score correlated positively with mortality ( p  < 0.05) with an ATT score ≥ 7 was 88% sensitive and 81% specific for predicting mortality. A 1-point increase in ATT score corresponded to 2.1 times decreased likelihood of survival. Mean hospital stay was 3 days longer for dog bite cases.  There was no increased mortality rate in canine patients that presented with the suspected risk factors. The only risk factor that predicted mortality was the ATT score. Schattauer GmbH Stuttgart.

The posterior skeletal thorax: rib-vertebral angle and axial vertebral rotation asymmetries in adolescent idiopathic scoliosis.

PubMed

Burwell, R G; Aujla, R K; Freeman, B J C; Dangerfield, P H; Cole, A A; Kirby, A S; Polak, F J; Pratt, R K; Moulton, A

2008-01-01

The deformity of the ribcage in thoracic adolescent idiopathic scoliosis (AIS) is viewed by most as being secondary to the spinal deformity, though a few consider it primary or involved in curve aggravation. Those who consider it primary ascribe pathogenetic significance to rib-vertebra angle asymmetry. In thoracic AIS, supra-apical rib-vertebra angle differences (RVADs) are reported to be associated with the severity of the Cobb angle. In this paper we attempt to evaluate rib and spinal pathomechanisms in thoracic and thnoracolumbar AIS using spinal radiographs and real-time ultrasound. On the radiographs by costo-vertebral angle asymmetries (rib-vertebral angle differences RVADs, and rib-spinal angle differences RSADs), apical vertebral rotation (AV) and apical vertebral translation (AVT) were measured; and by ultrasound, spine-rib rotation differences (SRRDs) were estimated. RVADs are largest at two and three vertebral levels above the apex where they correlate significantly and positively with Cobb angle and AVT but not AVR. In right thoracic AIS, the cause(s) of the RVA asymmetries is unknown: it may result from trunk muscle imbalance, or from ribs adjusting passively within the constraint of the fourth column of the spine to increasing spinal curvature from whatever cause. Several possible mechanisms may drive axial vertebral rotation including, biplanar spinal asymmetry, relative anterior spinal overgrowth, dorsal shear forces in the presence of normal vertebral axial rotation, asymmetry of rib linear growth, trunk muscle imbalance causing rib-vertebra angle asymmetry weakening the spinal rotation-defending system of bipedal gait, and CNS mechanisms.

Modified rib pivot lateral thoracotomy: a case series.

PubMed

Appelgrein, C; Hosgood, G

2018-01-01

To describe a modified rib pivot thoracotomy and its clinical application in client-owned dogs and cats. Case series of 24 dogs and 1 cat requiring a thoracotomy. A lateral thoracic incision over the required thoracic segment was made. The latissimus dorsi muscle was reflected dorsally. The predetermined rib was identified and the periosteum overlying the rib was elevated circumferentially, avoiding the intercostal neurovascular structures. Holes were pre-placed above and below the proposed osteotomy site. The rib was osteotomised and pivoted cranially. The pleura was incised and the required intrathoracic procedure was then performed. The thoracic cavity was closed by pre-placement of a suture through the pre-placed holes within the osteotomised rib. The pleura and intercostal musculature were closed, avoiding the intercostal neurovascular structures. The rib was re-apposed and the lateral approach was closed. The cases included were reviewed for both the rib pivoted as per the procedure required and postoperative complications. The study group comprised 8 Staffordshire Bull Terriers, 2 Poodles, 2 German Shepherd Dogs, 1 each of Basset Hound, Rhodesian Ridgeback, Golden Retriever, Australian Shepherd, Vizsla, Bull Mastiff, Schnauzer, Jack Russell Terrier, Bulldog, Deerhound, Labrador Retriever and Australian Terrier, and 1 cat. A modified rib pivot thoracotomy was performed for lung lobectomy (n = 11), oesophagectomy (7), subtotal pericardectomy (5), patent ductus arteriosus ligation (1) and thoracic duct ligation (1). Follow-up ranged from 2 to 40 weeks postoperatively. Postoperative complications included seroma formation in two dogs. A modified rib pivot thoracotomy should be considered as an alternative lateral thoracic approach with good exposure, minimal complications and low morbidity. © 2018 Australian Veterinary Association.

Action of the isolated canine diaphragm on the lower ribs at high lung volumes.

PubMed

De Troyer, André; Wilson, Theodore A

2014-10-15

The normal diaphragm has an inspiratory action on the lower ribs, but subjects with chronic obstructive pulmonary disease commonly have an inward displacement of the lateral portions of the lower rib cage during inspiration. This paradoxical displacement, conventionally called 'Hoover's sign', has traditionally been attributed to the direct action of radially oriented diaphragmatic muscle fibres. In the present study, the inspiratory intercostal muscles in all interspaces in anaesthetized dogs were severed so that the diaphragm was the only muscle active during inspiration. The displacements of the lower ribs along the craniocaudal and laterolateral axes and the changes in pleural pressure (∆Ppl) and transdiaphragmatic pressure were measured during occluded breaths and mechanical ventilation at different lung volumes between functional residual capacity (FRC) and total lung capacity. From these data, the separate effects on rib displacement of ∆Ppl and of the force exerted by the diaphragm on the ribs were determined. Isolated spontaneous diaphragm contraction at FRC displaced the lower ribs cranially and outward, but this motion was progressively reversed into a caudal and inward motion as lung volume increased. However, although the force exerted by the diaphragm on the ribs decreased with increasing volume, it continued to displace the ribs cranially and outward. These observations suggest that Hoover's sign is usually caused by the decrease in the zone of apposition and, thus, by the dominant effect of ∆Ppl on the lower ribs, rather than an inward pull from the diaphragm. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

The Matrix Rib Plating System: improving aesthetic outcomes in microvascular breast reconstruction.

PubMed

Ahdoot, Michael A; Echo, Anthony; Otake, Leo R; Son, Ji; Zeidler, Kamakshi R; Saadian, Isaac; Lee, Gordon K

2013-04-01

During microvascular breast reconstruction, exposure of internal mammary vessels (IMVs) is facilitated by the removal of a portion of the rib resulting in occasional chest contour deformity (CCD). The use of rib plating may reduce CCD and reduce postoperative pain. All patients underwent microvascular breast reconstruction using IMVs. In the retrospective arm, photographs were assessed by a blinded reviewer for CCDs. In the prospective cohort, patients were randomized to rib plating with the Synthes Matrix Rib Plating System or no rib plating. Postoperatively, patients were assessed for CCD and pain. In the retrospective arm, 11 of 98 (11.2%) patients representing 12 of 130 (9.2%) breast reconstructions had a noticeable contour deformity. The average body mass index (BMI) of patients with CCDs was 26.6 kg/m. In the prospective arm, there was 16% (3 of 19) rate of visible and palpable CCDs among controls, compared to 0% rate of palpable and visible contour deformity in the rib plating group. Pain was decreased in the rib plating group on all postoperative days. The pain reduction was statistically significant at rest by postoperative day 30. The majority of patients (9 of 11) with compromised aesthetic outcomes had a BMI less than 30 kg/m, suggesting a paucity of overlying soft tissue contributed to visibility of these bony defects. Rib plating prevented chest contour deformity, reduced postoperative pain, and added limited additional morbidity. We believe that rib plating is a safe, useful adjunct to microvascular breast reconstruction using IMVs, as it may improve aesthetic outcomes and reduce postoperative pain.

Pollen contamination in seed mixture increases the dominance of resistance to Bt maize in Spodoptera frugiperda (Lepidoptera: Noctuidae).

PubMed

Yang, Fei; Kerns, David L; Brown, Sebe; Head, Graham P; Huang, Fangneng

2017-11-01

Seed mixture, also called 'RIB', has been used to provide refuge populations for delaying insect resistance. Pollen contamination in RIB could result in refuge kernels of non-Bt maize expressing variable Bt proteins. Data are lacking regarding the impact of pollen contamination on evolution of resistance for ear-feeding insects. Here, we used Spodoptera frugiperda and Cry1F-maize as a model to examine if pollen contamination in RIB increases the dominance of insect resistance. Pollen contamination caused >66% refuge kernels in 5:95% (non-Bt:Bt) and 20:80% RIBs to express Cry1F protein. Survival at adult stage on pure non-Bt ears was similar (54.4-63.3%) among Cry1F-susceptible (SS), Cry1F-resistant (RR) and Cry1F-heterozygous (RS) S. frugiperda. On Bt ears, survival was similar between SS and RS (0.0-1.7%), but it was significantly less than that of RR (59.2%). On the two RIB refuge ears, survival at adult stage for RS (42.3% in 5:95% RIB; 50.0% in 20:80% RIB) was significantly higher than for SS (8.7% in 5:95% RIB; 10.0% in 20:80% RIB). The results suggest that pollen contamination in RIB could increase the dominance of resistance for ear-feeding insects by significantly reducing susceptible refuge populations and supporting higher survival of heterozygotes relative to homozygous susceptible insects. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Digital radiography of crush thoracic trauma in the Sichuan earthquake

PubMed Central

Dong, Zhi-Hui; Shao, Heng; Chen, Tian-Wu; Chu, Zhi-Gang; Deng, Wen; Tang, Si-Shi; Chen, Jing; Yang, Zhi-Gang

2011-01-01

AIM: To investigate the features of crush thoracic trauma in Sichuan earthquake victims using chest digital radiography (CDR). METHODS: We retrospectively reviewed 772 CDR of 417 females and 355 males who had suffered crush thoracic trauma in the Sichuan earthquake. Patient age ranged from 0.5 to 103 years. CDR was performed between May 12, 2008 and June 7, 2008. We looked for injury to the thoracic cage, pulmonary parenchyma and the pleura. RESULTS: Antero-posterior (AP) and lateral CDR were obtained in 349 patients, the remaining 423 patients underwent only AP CDR. Thoracic cage fractures, pulmonary contusion and pleural injuries were noted in 331 (42.9%; 95% CI: 39.4%-46.4%), 67 and 135 patients, respectively. Of the 256 patients with rib fractures, the mean number of fractured ribs per patient was 3. Rib fractures were mostly distributed from the 3rd through to the 8th ribs and the vast majority involved posterior and lateral locations along the rib. Rib fractures had a significant positive association with non-rib thoracic fractures, pulmonary contusion and pleural injuries (P < 0.001). The number of rib fractures and pulmonary contusions were significant factors associated with patient death. CONCLUSION: Earthquake-related crush thoracic trauma has the potential for multiple fractures. The high number of fractured ribs and pulmonary contusions were significant factors which needed appropriate medical treatment. PMID:22132298

Quality of life after major trauma with multiple rib fractures.

PubMed

Marasco, Silvana; Lee, Geraldine; Summerhayes, Robyn; Fitzgerald, Mark; Bailey, Michael

2015-01-01

Rib fractures are a common injury presenting to major trauma centres and community hospitals. Aside from the acute impact of rib fracture injury, longer-term morbidity of pain, disability and deformity have been described. Despite this, the mainstay of management for the vast majority of rib fracture injuries remains supportive only with analgesia and where required respiratory support. This study aimed to document the long-term quality of life in a cohort of major trauma patients with rib fracture injury over 24 months. Retrospective review (July 2006-July 2011) of 397 major trauma patients admitted to The Alfred Hospital with rib fractures and not treated with operative rib fixation. The main outcome measures were quality of life over 24 months post injury assessed using the Glasgow Outcome Scale Extended and SF12 health assessment forms and a pain questionnaire. Assessment over 24 months of major trauma patients with multiple rib fractures demonstrated significantly lower quality of life compared with published Australian norms at all time points measured. Return to work rates were poor with only 71% of those who were working prior to their accident, returning to any work. This study demonstrates a significant reduction in quality of life for rib fracture patients requiring admission to hospital, which does not return to the level of Australian norms for at least two years. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

30 CFR 75.202 - Protection from falls of roof, face and ribs.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or travel shall be supported or otherwise controlled to protect persons from hazards related to falls of the...

30 CFR 75.202 - Protection from falls of roof, face and ribs.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or travel shall be supported or otherwise controlled to protect persons from hazards related to falls of the...

30 CFR 75.202 - Protection from falls of roof, face and ribs.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or travel shall be supported or otherwise controlled to protect persons from hazards related to falls of the...

30 CFR 75.202 - Protection from falls of roof, face and ribs.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or travel shall be supported or otherwise controlled to protect persons from hazards related to falls of the...

30 CFR 75.202 - Protection from falls of roof, face and ribs.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection from falls of roof, face and ribs... Protection from falls of roof, face and ribs. (a) The roof, face and ribs of areas where persons work or travel shall be supported or otherwise controlled to protect persons from hazards related to falls of the...

Comparison of Computed Tomography and Chest Radiography in the Detection of Rib Fractures in Abused Infants

ERIC Educational Resources Information Center

Wootton-Gorges, Sandra L.; Stein-Wexler, Rebecca; Walton, John W.; Rosas, Angela J.; Coulter, Kevin P.; Rogers, Kristen K.

2008-01-01

Purpose: Chest radiographs (CXR) are the standard method for evaluating rib fractures in abused infants. Computed tomography (CT) is a sensitive method to detect rib fractures. The purpose of this study was to compare CT and CXR in the evaluation of rib fractures in abused infants. Methods: This retrospective study included all 12 abused infants…

Role of a polymorphism in a Hox/Pax-responsive enhancer in the evolution of the vertebrate spine

USGS Publications Warehouse

Guerreiro, Isabel; Nunes, Andreia; Woltering, Joost M.; Casaca, Ana; Nóvoa, Ana; Vinagre, Tânia; Hunter, Margaret E.; Duboule, Denis; Mallo, Moisés

2013-01-01

Patterning of the vertebrate skeleton requires the coordinated activity of Hox genes. In particular, Hox10 proteins are essential to set the transition from thoracic to lumbar vertebrae because of their rib-repressing activity. In snakes, however, the thoracic region extends well into Hox10-expressing areas of the embryo, suggesting that these proteins are unable to block rib formation. Here, we show that this is not a result of the loss of rib-repressing properties by the snake proteins, but rather to a single base pair change in a Hox/Paired box (Pax)-responsive enhancer, which prevents the binding of Hox proteins. This polymorphism is also found in Paenungulata, such as elephants and manatees, which have extended rib cages. In vivo, this modified enhancer failed to respond to Hox10 activity, supporting its role in the extension of rib cages. In contrast, the enhancer could still interact with Hoxb6 and Pax3 to promote rib formation. These results suggest that a polymorphism in the Hox/Pax-responsive enhancer may have played a role in the evolution of the vertebrate spine by differently modulating its response to rib-suppressing and rib-promoting Hox proteins.

Design of a rib impactor equipment

NASA Astrophysics Data System (ADS)

Torres, C. R.; García, G.; Aguilar, L. A.; Martínez, L.

2017-01-01

The human ribs must be analyzed as long and as curved bones, due to their physiology. For the development of an experimental equipment that simulate the application of loads, over the rib in the moment of a frontal collision in an automobile with seat belt, it was applied a methodology that constituted in the identification of needs and the variables which led the design of 3D model, from this it was used the technique of fused deposition modeling for the development of the equipment pieces. The supports that hold the rib ends were design with two and three degrees of freedom that allows the simulation of rib movement with the spine and the breastbone in the breathing. For the simulation of the seat belt, it was determined to applied two loads over the front part of the rib from the sagittal and lateral plane respectively, for this it was made a displacement through a lineal actuator with a speed of 4mm/s. The outcomes shown a design of an equipment able to obtain the load parameters required to generate fractures in rib specimens. The equipment may be used for the study of specimens with nearby geometries to the rib taken as a reference.

Research into topology optimization and the FDM method for a space cracked membrane

NASA Astrophysics Data System (ADS)

Hu, Qingxi; Li, Wanyuan; Zhang, Haiguang; Liu, Dali; Peng, Fujun; Duan, Yongchao

2017-07-01

The problem that the space membranes are easily torn open is the main focus in this paper, and a bionic strengthening-ribs structure is proposed for a space membrane based on interdisciplinary strengths, such as topology optimization, composite materials, and rapid prototyping. The optimization method and modeling method of membranes with bionic strengthening-ribs was studied. The PEEK and SCF/PEEK composite material which are applied to the space environment are chosen, and FDM technology is used. Through topology optimization, bionic strengthening-ribs with good tensile and tear capacities were obtained. Cracked membranes, cracked membranes with PEEK strengthening-ribs and SCF/PEEK strengthening-ribs were tested and test data were obtained. An extension situation and tension fracture were compared for three cases. The experimental results showed that membranes with the bionic strengthening-ribs structure have better mechanical properties, and the strength of the membranes with PEEK and SCF/PEEK strengthening-ribs were raised, respectively, up to 266.9% and 185.9%. The strengthening-ribs structure greatly improves the capacity to halt membrane crack-growth, which has an important significance to avoid membrane tear, and to ensure the spacecraft orbital lifetime.

Rib fractures in trauma patients: does operative fixation improve outcome?

PubMed

Majak, Peter; Næss, Pål A

2016-12-01

Renewed interest in surgical fixation of rib fractures has emerged. However, conservative treatment is still preferred at most surgical departments. We wanted to evaluate whether operative treatment of rib fractures may benefit severely injured patients. Several studies report a reduction in mechanical ventilation time, ICU length of stay (LOS), hospital LOS, pneumonia, need for tracheostomy, pain and costs in operatively treated patients with multiple rib fractures compared with patients treated nonoperatively. Although patient selection and timing of the operation seem crucial for successful outcome, no consensus exists. Mortality reduction has only been shown in a few studies. Most studies are retrospective cohort and case-control studies. Only four randomized control trials exist. Conservative treatment, consisting of respiratory assistance and pain control, is still the treatment of choice in the vast majority of patients with multiple rib fractures. In selected patients, operative fixation of fractured ribs within 72 h postinjury may lead to better outcome. More randomized control trials are needed to further determine who benefits from surgical fixation of rib fractures.

Nozzle airfoil having movable nozzle ribs

DOEpatents

Yu, Yufeng Phillip; Itzel, Gary Michael

2002-01-01

A nozzle vane or airfoil structure is provided in which the nozzle ribs are connected to the side walls of the vane or airfoil in such a way that the ribs provide the requisite mechanical support between the concave side and convex side of the airfoil but are not locked in the radial direction of the assembly, longitudinally of the airfoil. The ribs may be bi-cast onto a preformed airfoil side wall structure or fastened to the airfoil by an interlocking slide connection and/or welding. By attaching the nozzle ribs to the nozzle airfoil metal in such a way that allows play longitudinally of the airfoil, the temperature difference induced radial thermal stresses at the nozzle airfoil/rib joint area are reduced while maintaining proper mechanical support of the nozzle side walls.

Slipping rib syndrome: a place for sonography in the diagnosis of a frequently overlooked cause of abdominal or low thoracic pain.

PubMed

Meuwly, Jean-Yves; Wicky, Stephan; Schnyder, Pierre; Lepori, Domenico

2002-03-01

To describe the sonographic appearance of a poorly recognized cause of low thoracic or upper abdominal pain. Three sonographic descriptions of slipping rib syndrome are presented. The 3 patients had abnormal mobility of a cartilaginous rib, which could slip over an adjacent rib during abdominal muscle contraction. Slipping rib syndrome should be considered in patients with histories of upper abdominal or low thoracic pain of unknown origin. We suggest that high-resolution sonography of the costal margin should be added to abdominal sonography in cases of nonspecific abdominal pain.

Rib fracture following stereotactic body radiotherapy: a potential pitfall.

PubMed

Stanic, Sinisa; Boike, Thomas P; Rule, William G; Timmerman, Robert D

2011-11-01

Although the incidence of rib fractures after conventional radiotherapy is generally low (<2%), rib fractures are a relatively common complication of stereotactic body radiotherapy. For malignancy adjacent to the chest wall, the incidence of rib fractures after stereotactic body radiotherapy is as high as 10%. Unrecognized bone fractures can mimic bone metastases on bone scintigraphy, can lead to extensive workup, and can even lead to consideration of unnecessary systemic chemotherapy, as treatment decisions can be based on imaging findings alone. Nuclear medicine physicians and diagnostic radiologists should always consider rib fracture in the differential diagnosis.

Effect of rib angle on local heat/mass transfer distribution in a two-pass rib-roughened channel

NASA Technical Reports Server (NTRS)

Chandra, P. R.; Han, J. C.; Lau, S. C.

1987-01-01

The naphthalene sublimation technique is used to investigate the heat transfer characteristics of turbulent air flow in a two-pass channel. A test section that resembles the internal cooling passages of gas turbine airfoils is employed. The local Sherwood numbers on the ribbed walls were found to be 1.5-6.5 times those for a fully developed flow in a smooth square duct. Depending on the rib angle-of-attack and the Reynolds number, the average ribbed-wall Sherwood numbers were 2.5-3.5 times higher than the fully developed values.

Validation and Analysis of Numerical Results for a Two-Pass Trapezoidal Channel With Different Cooling Configurations of Trailing Edge.

PubMed

Siddique, Waseem; El-Gabry, Lamyaa; Shevchuk, Igor V; Fransson, Torsten H

2013-01-01

High inlet temperatures in a gas turbine lead to an increase in the thermal efficiency of the gas turbine. This results in the requirement of cooling of gas turbine blades/vanes. Internal cooling of the gas turbine blade/vanes with the help of two-pass channels is one of the effective methods to reduce the metal temperatures. In particular, the trailing edge of a turbine vane is a critical area, where effective cooling is required. The trailing edge can be modeled as a trapezoidal channel. This paper describes the numerical validation of the heat transfer and pressure drop in a trapezoidal channel with and without orthogonal ribs at the bottom surface. A new concept of ribbed trailing edge has been introduced in this paper which presents a numerical study of several trailing edge cooling configurations based on the placement of ribs at different walls. The baseline geometries are two-pass trapezoidal channels with and without orthogonal ribs at the bottom surface of the channel. Ribs induce secondary flow which results in enhancement of heat transfer; therefore, for enhancement of heat transfer at the trailing edge, ribs are placed at the trailing edge surface in three different configurations: first without ribs at the bottom surface, then ribs at the trailing edge surface in-line with the ribs at the bottom surface, and finally staggered ribs. Heat transfer and pressure drop is calculated at Reynolds number equal to 9400 for all configurations. Different turbulent models are used for the validation of the numerical results. For the smooth channel low-Re k-ɛ model, realizable k-ɛ model, the RNG k-ω model, low-Re k-ω model, and SST k-ω models are compared, whereas for ribbed channel, low-Re k-ɛ model and SST k-ω models are compared. The results show that the low-Re k-ɛ model, which predicts the heat transfer in outlet pass of the smooth channels with difference of +7%, underpredicts the heat transfer by -17% in case of ribbed channel compared to experimental data. Using the same turbulence model shows that the height of ribs used in the study is not suitable for inducing secondary flow. Also, the orthogonal rib does not strengthen the secondary flow rotational momentum. The comparison between the new designs for trailing edge shows that if pressure drop is acceptable, staggered arrangement is suitable for the outlet pass heat transfer. For the trailing edge wall, the thermal performance for the ribbed trailing edge only was found about 8% better than other configurations.

Delayed pneumothorax complicating minor rib fracture after chest trauma.

PubMed

Lu, Ming-Shian; Huang, Yao-Kuang; Liu, Yun-Hen; Liu, Hui-Ping; Kao, Chiung-Lun

2008-06-01

Pneumothorax (PTX) after trauma is a preventable cause of death. Drainage procedures such as chest tube insertion have been traditionally advocated to prevent fatal tension PTX. We evaluated the safety of close observation in patients with delayed PTX complicating rib fracture after minor chest trauma. Adult patients (>18 years) with a diagnosis of chest trauma and 3 or fewer fractured ribs were reviewed. Case patients were divided according to age, location and number of fractured ribs, mechanism of trauma, and initial pulmonary complication after thoracic trauma for comparative analysis. There were 207 male (70.2%) and 88 female (29.8%) patients whose ages ranged from 18 to 93 years (median, 55 years). The mechanisms of trauma were a motor vehicle accident in 207 patients, falls in 66, pedestrian injury in 10, and assaults in 14. Ninety-five patients sustained 1 rib fracture, 95 had 2 rib fractures, and 105 suffered 3 rib fractures. Right-sided injury occurred in 164 cases, left-sided injury did in 127, and bilateral injury did in 4. The most frequent location of rib fractures was from the fourth rib to the ninth rib. The initial pulmonary complications after trauma were PTX in 16 patients, hemothorax in 43, pneumohemothorax in 14, lung contusion in 75, and isolated subcutaneous emphysema (SubcEmph) in 33. Thirty percent of the patients (n = 5/16) who presented with traumatic PTX were observed safely without drainage. Delayed PTX was recorded in 16 patients, occurring mostly during the first 2 days of their admission. Associated extrathoracic injury was recorded in 189 patients. The mean hospital stay of the patients was 7.66 days. Longer hospital stay was related to increasing number of fractured ribs, need for thoracic drainage, and the presence of associated extrathoracic injury. The mortality rate for the entire group was 2%. The presence of SubcEmph was the only risk factor associated with the development of delayed PTX. Patients sustaining blunt chest trauma and minor rib fractures should be admitted for close observation when presenting with SubcEmph because of possible delayed presentation of PTX.

Analysis of cervical ribs in a series of human fetuses

PubMed Central

Bots, Jessica; Wijnaendts, Liliane C D; Delen, Sofie; Van Dongen, Stefan; Heikinheimo, Kristiina; Galis, Frietson

2011-01-01

In humans, an increasing body of evidence has linked the frequency of cervical ribs to stillbirths, other malformations and early childhood cancers. However, the frequency of cervical ribs in a putatively healthy fetal population is not sufficiently known to assess the actual medical risks of these prenatal findings. We therefore analyzed the presence of skeletal anomalies in a series of 199 electively aborted fetuses, which were whole-mount stained with alizarin red specific for skeletal tissues. Results show that approximately 40% of the fetuses had cervical ribs, even though external congenital abnormalities such as craniofacial and limb defects were absent. A literature overview indicates that the observed frequency of cervical ribs is comparable to results previously obtained for deceased fetuses with no or minor congenital anomalies, and higher than expected for healthy fetuses. This unexpected result can probably in part be explained by a higher detection rate of small cervical ribs when using alizarin red staining instead of radiographs. Additionally, studies in the literature suggest that the size of a cervical rib may indicate the severity of abnormalities, but this possibility requires further research. Anomalies of the axial skeleton are known to be caused by a disturbance of early development, which alters Hox gene expression, but in this study the origin of the stress could not be verified as maternal medical data were not available. The co-occurrence of rudimentary or absent 12th ribs in 23.6% of the cases with cervical ribs indicates that in approximately 8% of the fetuses a homeotic shift occurred over a larger part of the vertebral column. This suggests that the expression of multiple Hox genes may have been affected in these fetuses. Together, the high incidence of cervical ribs and also their co-occurrence with rudimentary or absent 12th ribs suggests that there may have been a disturbance of early development such that the studied fetuses are probably not informative about the general population. Future studies determining the frequency of cervical ribs in a more healthy fetal population are therefore needed to evaluate their potential as an indicator of medical risks. PMID:21689099

Low evaluation rate for osteoporosis among patients presenting with a rib fracture.

PubMed

Kim, Whang; Gong, Hyun Sik; Lee, Seung Hoo; Park, Jin Woo; Kim, Kahyun; Baek, Goo Hyun

2017-12-01

This study in a regional hospital setting found a low evaluation rate for osteoporosis among patients presenting with a rib fracture. Increased emphasis or education for osteoporosis evaluation may be necessary in case of rib fractures. Rib fractures from a low-energy trauma are common in the elderly, and a history of rib fracture has been reported to increase the risk for a subsequent osteoporotic fracture. The purpose of this study was to evaluate how many of the patients presenting with an isolated rib fracture were being evaluated for osteoporosis and the risk for a subsequent fracture. We retrospectively reviewed all patients aged 50 years or older who were diagnosed with a rib fracture between January 2011 and April 2016 at a regional tertiary care university hospital near Seoul, South Korea. We excluded those who had been treated for osteoporosis or those with other concomitant fractures or fractures from a motor vehicle accident or cancer. We evaluated the frequency of dual energy X-ray absorptiometry (DXA) scan examinations in these patients. There were 231 patients with isolated rib fractures (132 men and 99 women). The mean age was 65 years. Rib fractures were most commonly diagnosed at the emergency department and most of the patients were referred to the department of thoracic surgery for follow-up evaluations. Of these 231 patients, 29 (12%) had DXA examinations after the injury, and only 9 (4%) of them did so within 6 months. Physicians specializing in orthopedic surgery, family medicine, internal medicine, rehabilitation medicine, and emergency medicine were ordering the examination. This study in a regional hospital setting found a low evaluation rate for osteoporosis among patients presenting with a rib fracture. This study suggests that increased emphasis or education for osteoporosis evaluation may be necessary for physicians who are often referred to for care of rib fractures.

Rib fracture after stereotactic radiotherapy for primary lung cancer: prevalence, degree of clinical symptoms, and risk factors.

PubMed

Nambu, Atsushi; Onishi, Hiroshi; Aoki, Shinichi; Tominaga, Licht; Kuriyama, Kengo; Araya, Masayuki; Saito, Ryoh; Maehata, Yoshiyasu; Komiyama, Takafumi; Marino, Kan; Koshiishi, Tsuyota; Sawada, Eiichi; Araki, Tsutomu

2013-02-07

As stereotactic body radiotherapy (SBRT) is a highly dose-dense radiotherapy, adverse events of neighboring normal tissues are a major concern. This study thus aimed to clarify the frequency and degree of clinical symptoms in patients with rib fractures after SBRT for primary lung cancer and to reveal risk factors for rib fracture. Appropriate α/β ratios for discriminating between fracture and non-fracture groups were also investigated. Between November 2001 and April 2009, 177 patients who had undergone SBRT were evaluated for clinical symptoms and underwent follow-up thin-section computed tomography (CT). The time of rib fracture appearance was also assessed. Cox proportional hazard modeling was performed to identify risk factors for rib fracture, using independent variables of age, sex, maximum tumor diameter, radiotherapeutic method and tumor-chest wall distance. Dosimetric details were analyzed for 26 patients with and 22 randomly-sampled patients without rib fracture. Biologically effective dose (BED) was calculated with a range of α/β ratios (1-10 Gy). Receiver operating characteristics analysis was used to define the most appropriate α/β ratio. Rib fracture was found on follow-up thin-section CT in 41 patients. The frequency of chest wall pain in patients with rib fracture was 34.1% (14/41), and was classified as Grade 1 or 2. Significant risk factors for rib fracture were smaller tumor-chest wall distance and female sex. Area under the curve was maximal for BED at an α/β ratio of 8 Gy. Rib fracture is frequently seen on CT after SBRT for lung cancer. Small tumor-chest wall distance and female sex are risk factors for rib fracture. However, clinical symptoms are infrequent and generally mild. When using BED analysis, an α/β ratio of 8 Gy appears most effective for discriminating between fracture and non-fracture patients.

Traumatic Vertebral Fractures and Concomitant Fractures of the Rib in Southwest China, 2001 to 2010

PubMed Central

Wang, Hongwei; Zhou, Yue; Ou, Lan; Li, Changqing; Liu, Jun; Xiang, Liangbi

2015-01-01

Abstract To our knowledge, the clinical characteristics of traumatic vertebral fractures and concomitant fractures of the rib (TVF-RF) have not been described in previous studies. To investigate the clinical characteristics of patients managed for TVF-RF. A retrospective study of 3142 patients who presented with traumatic vertebral fractures was performed. Two hundred twenty-six patients (7.2%) suffered from TVF-RF. Incidence rate ratios were then calculated with respect to the level of injury to the spine, the ASIA classification of neurological deficits and age. There were 171 male (75.7%) and 55 female (24.3%) patients with a mean age of 43.8 years. The most common mechanisms were falls from high heights in 81 cases and road traffic crashes in 67 cases. Right-sided rib injury occurred in 106 cases, left-sided injury occurred in 76 cases, and bilateral injury occurred in 44 cases. The most frequent location of the rib fractures was from the fourth rib to the ninth rib (70.3%, 510/725). Initial pulmonary complications (IPC) after trauma occurred in 116 cases (51.3%). The mortality rate for the entire group was 1.3% (3/226). The patients with thoracic vertebral fractures and neurological deficits had a higher frequency of multiple rib fractures and IPC than the other patients (P < 0.05). With the increased number of rib fractures, the frequency of IPC and mean intensive care unit (ICU) length of stay also increased. The rates of complications for patients with rib fractures were significantly different from those without rib fractures. We should pay much attention to the patients who presented with thoracic vertebral fractures and neurological deficits for minimizing further complications and mortality in such patients who had a higher frequency of multiple rib fractures and IPC than the other patients. PMID:26554809

Rib fracture after stereotactic radiotherapy for primary lung cancer: prevalence, degree of clinical symptoms, and risk factors

PubMed Central

2013-01-01

Background As stereotactic body radiotherapy (SBRT) is a highly dose-dense radiotherapy, adverse events of neighboring normal tissues are a major concern. This study thus aimed to clarify the frequency and degree of clinical symptoms in patients with rib fractures after SBRT for primary lung cancer and to reveal risk factors for rib fracture. Appropriate α/β ratios for discriminating between fracture and non-fracture groups were also investigated. Methods Between November 2001 and April 2009, 177 patients who had undergone SBRT were evaluated for clinical symptoms and underwent follow-up thin-section computed tomography (CT). The time of rib fracture appearance was also assessed. Cox proportional hazard modeling was performed to identify risk factors for rib fracture, using independent variables of age, sex, maximum tumor diameter, radiotherapeutic method and tumor-chest wall distance. Dosimetric details were analyzed for 26 patients with and 22 randomly-sampled patients without rib fracture. Biologically effective dose (BED) was calculated with a range of α/β ratios (1–10 Gy). Receiver operating characteristics analysis was used to define the most appropriate α/β ratio. Results Rib fracture was found on follow-up thin-section CT in 41 patients. The frequency of chest wall pain in patients with rib fracture was 34.1% (14/41), and was classified as Grade 1 or 2. Significant risk factors for rib fracture were smaller tumor-chest wall distance and female sex. Area under the curve was maximal for BED at an α/β ratio of 8 Gy. Conclusions Rib fracture is frequently seen on CT after SBRT for lung cancer. Small tumor-chest wall distance and female sex are risk factors for rib fracture. However, clinical symptoms are infrequent and generally mild. When using BED analysis, an α/β ratio of 8 Gy appears most effective for discriminating between fracture and non-fracture patients. PMID:23391264

Sex determination based on a thoracic vertebra and ribs evaluation using clinical chest radiography.

PubMed

Tsubaki, Shun; Morishita, Junji; Usumoto, Yosuke; Sakaguchi, Kyoko; Matsunobu, Yusuke; Kawazoe, Yusuke; Okumura, Miki; Ikeda, Noriaki

2017-07-01

Our aim was to investigate whether sex can be determined from a combination of geometric features obtained from the 10th thoracic vertebra, 6th rib, and 7th rib. Six hundred chest radiographs (300 males and 300 females) were randomly selected to include patients of six age groups (20s, 30s, 40s, 50s, 60s, and 70s). Each group included 100 images (50 males and 50 females). A total of 14 features, including 7 lengths, 5 indices for the vertebra, and 2 types of widths for ribs, were utilized and analyzed for sex determination. Dominant features contributing to sex determination were selected by stepwise discriminant analysis after checking the variance inflation factors for multicollinearity. The accuracy of sex determination using a combination of the vertebra and ribs was evaluated from the selected features by the stepwise discriminant analysis. The accuracies in each age group were also evaluated in this study. The accuracy of sex determination based on a combination of features of the vertebra and ribs was 88.8% (533/600). This performance was superior to that of the vertebra or ribs only. Moreover, sex determination of subjects in their 20s demonstrated the highest accuracy (96.0%, 96/100). The features selected in the stepwise discriminant analysis included some features in both the vertebra and ribs. These results indicate the usefulness of combined information obtained from the vertebra and ribs for sex determination. We conclude that a combination of geometric characteristics obtained from the vertebra and ribs could be useful for determining sex. Copyright © 2017 Elsevier B.V. All rights reserved.

Internal rib structure can be predicted using mathematical models: An anatomic study comparing the chest to a shell dome with application to understanding fractures.

PubMed

Casha, Aaron R; Camilleri, Liberato; Manché, Alexander; Gatt, Ruben; Attard, Daphne; Gauci, Marilyn; Camilleri-Podesta, Marie-Therese; Mcdonald, Stuart; Grima, Joseph N

2015-11-01

The human rib cage resembles a masonry dome in shape. Masonry domes have a particular construction that mimics stress distribution. Rib cortical thickness and bone density were analyzed to determine whether the morphology of the rib cage is sufficiently similar to a shell dome for internal rib structure to be predicted mathematically. A finite element analysis (FEA) simulation was used to measure stresses on the internal and external surfaces of a chest-shaped dome. Inner and outer rib cortical thickness and bone density were measured in the mid-axillary lines of seven cadaveric rib cages using computerized tomography scanning. Paired t tests and Pearson correlation were used to relate cortical thickness and bone density to stress. FEA modeling showed that the stress was 82% higher on the internal than the external surface, with a gradual decrease in internal and external wall stresses from the base to the apex. The inner cortex was more radio-dense, P < 0.001, and thicker, P < 0.001, than the outer cortex. Inner cortical thickness was related to internal stress, r = 0.94, P < 0.001, inner cortical bone density to internal stress, r = 0.87, P = 0.003, and outer cortical thickness to external stress, r = 0.65, P = 0.035. Mathematical models were developed relating internal and external cortical thicknesses and bone densities to rib level. The internal anatomical features of ribs, including the inner and outer cortical thicknesses and bone densities, are similar to the stress distribution in dome-shaped structures modeled using FEA computer simulations of a thick-walled dome pressure vessel. Fixation of rib fractures should include the stronger internal cortex. © 2015 Wiley Periodicals, Inc.

When Should Abdominal Computed Tomography Be Considered in Patients with Lower Rib Fractures?

PubMed

Jeroukhimov, Igor; Hershkovitz, Yehuda; Wiser, Itay; Kessel, Boris; Ayyad, Mohammed; Gatot, Inbar; Shapira, Zahar; Jeoravlev, Svetlana; Halevy, Ariel; Lavy, Ron

2017-05-01

Lower rib fractures are considered as a marker of intra-abdominal organ injury. Abdominal computed tomography (CT) is the "gold standard" examination for patients with lower rib fractures. However, the reported incidence of concomitant intra-abdominal injuries (IAI) is 20%-40%. The purpose of this study was to evaluate the incidence of intra-abdominal organ injuries in blunt trauma patients with lower rib fractures. Medical charts and radiology reports of patients with lower rib (from the 8th to 12th rib) fractures admitted to our center during a 6-year period were retrospectively reviewed. Patients were divided into two groups. Group I included patients with intra-abdominal injury (IAI) diagnosed either by CT or on urgent laparotomy, and Group II included those with normal abdominal CT scans. Data included demographics, mechanism of injury, laboratory tests, radiology results including number and location of fractured ribs, and incidence of IAI. Overall 318 patients were included in the study. Fifty-seven patients (17.9%) had 71 IAIs compared with 265 (82.1%) patients with no IAI. Logistic regression identified age younger than 55 years (relative risk [RR] = 7.2; 95% confidence interval [CI] 3.1-16.8; p = 0.001), bilateral rib fractures (RR = 3.9; 95% CI 1.1-13.5; p = 0.03) and decreased levels of hematocrit (RR = 2.4; 95% CI 1.2-4.8; p = 0.016) as independent risk factors for the presence of IAI. Abdominal CT should be considered in blunt trauma patients with lower rib fractures who are younger than 55 years of age and have bilateral rib fractures and decreased levels of hematocrit on admission. Copyright © 2016 Elsevier Inc. All rights reserved.

Clinical Utility of Chest Computed Tomography in Patients with Rib Fractures CT Chest and Rib Fractures.

PubMed

Chapman, Brandon C; Overbey, Douglas M; Tesfalidet, Feven; Schramm, Kristofer; Stovall, Robert T; French, Andrew; Johnson, Jeffrey L; Burlew, Clay C; Barnett, Carlton; Moore, Ernest E; Pieracci, Fredric M

2016-12-01

Chest CT is more sensitive than a chest X-ray (CXR) in diagnosing rib fractures; however, the clinical significance of these fractures remains unclear. The purpose of this study was to determine the added diagnostic use of chest CT performed after CXR in patients with either known or suspected rib fractures secondary to blunt trauma. Retrospective cohort study of blunt trauma patients with rib fractures at a level I trauma center that had both a CXR and a CT chest. The CT finding of ≥ 3 additional fractures in patients with ≤ 3 rib fractures on CXR was considered clinically meaningful. Student's t-test and chi-square analysis were used for comparison. We identified 499 patients with rib fractures: 93 (18.6%) had CXR only, 7 (1.4%) had chest CT only, and 399 (79.9%) had both CXR and chest CT. Among these 399 patients, a total of 1,969 rib fractures were identified: 1,467 (74.5%) were missed by CXR. The median number of additional fractures identified by CT was 3 (range, 4 - 15). Of 212 (53.1%) patients with a clinically meaningful increase in the number of fractures, 68 patients underwent one or more clinical interventions: 36 SICU admissions, 20 pain catheter placements, 23 epidural placements, and 3 SSRF. Additionally, 70 patients had a chest tube placed for retained hemothorax or occult pneumothorax. Overall, 138 patients (34.5%) had a change in clinical management based upon CT chest. The chest X-ray missed ~75% of rib fractures seen on chest CT. Although patients with a clinical meaningful increase in the number of rib fractures were more likely to be admitted to the intensive care unit, there was no associated improvement in pulmonary outcomes.

Sex estimation from measurements of the first rib in a contemporary Polish population.

PubMed

Kubicka, Anna Maria; Piontek, Janusz

2016-01-01

The aim of this study was to evaluate the accuracy of sex assessment using measurements of the first rib from computed tomography (CT) to develop a discriminant formula. Four discriminant formulae were derived based on CT imaging of the right first rib of 85 female and 91 male Polish patients of known age and sex. In direct discriminant analysis, the first equation consisted of all first rib variables; the second included measurements of the rib body; the third comprised only two measurements of the sternal end of the first rib. The stepwise method selected the four best variables from all measurements. The discriminant function equation was then tested on a cross-validated group consisting of 23 females and 24 males. The direct discriminant analysis showed that sex assessment was possible in 81.5% of cases in the first group and in 91.5% in the cross-validated group when all variables for the first rib were included. The average accuracy for the original group for rib body and sternal end was 80.9 and 67.9%, respectively. The percentages of correctly assigned individuals for the functions based on the rib body and sternal end in the cross-validated group were 76.6 and 85.0%, respectively. Higher average accuracies were obtained for stepwise discriminant analysis: 83.1% for the original group and 91.2% for the cross-validated group. The exterior edge, anterior-posterior of the sternal end, and depth of the arc were the most reliable parameters. Our results suggest that the first rib is dimorphic and that the described method can be used for sex assessment.

Ribbed electrode substrates

DOEpatents

Breault, Richard D.; Goller, Glen J.

1983-01-01

A ribbed substrate for an electrochemical cell electrode is made from a mixture of carbon fibers and carbonizable resin and has a mean pore size in the ribs which is 60-75% of the mean pore size of the web portions of the substrate which interconnect the ribs. Preferably the mean pore size of the web portion is 25-45 microns; and, if the substrate includes edge seals parallel to the ribs, the edge seals preferably have a mean pore size no greater than about ten microns. Most preferably the substrate has the same ratio of carbon fibers to polymeric carbon in all areas, including the ribs, webs, and edge seals. A substrate according to the present invention will have better overall performance than prior art substrates and minimizes the substrate thickness required for the substrate to perform all its functions well.

Cerebro-costo-mandibular syndrome: prognosis and proposal for classification.

PubMed

Nagasawa, Hiroyuki; Yamamoto, Yutaka; Kohno, Yoshinori

2010-09-01

Cerebro-costo-mandibular syndrome (CCMS) is a very rare syndrome characterized by micrognathia and posterior rib gap, with a poor prognosis. To date, only 75 cases have been reported worldwide. The overall survival rate for patients with this disorder has not been reported, and a classification of the patients on the basis of the prognosis is not yet available. The present study analyzed the figures and prognoses of past patients and documented a new case of CCMS. Formerly published case reports and personal communications were used to reveal the prognosis and classification of CCMS. The occurrence ratios of rib gap defects and of missing ribs were examined. Patients were divided into the following three groups according to their life span: lethal type, where the patients died before 1 month; severe type, where the patients lived for 1-12 months; and mild type, where they survived for more than 1 year. A comparison was made of the number of rib gaps, missing ribs, and the rib gap ratio (defined as the number of rib gaps divided by the number of all existing ribs) among these three groups. A significant difference in the number of rib defects between the lethal type and other types was noted. Short life span of severe type patients, compared to mild type, was attributed to their subjection to severe respiratory infection. CCMS can be classified into three categories--lethal, severe, and mild--according to the severity of the symptoms and prognosis.

The mechanoreceptors of the costo-vertebral joints

PubMed Central

Godwin-Austen, R. B.

1969-01-01

1. Unitary recording in the thoracic dorsal roots of mechanoreceptor discharges from the costo-vertebral joints was carried out in the cat and rabbit. Criteria for the identification of costo-vertebral joint mechanoreceptors were established. 2. The majority of rib joint mechanoreceptors are slowly adapting and fifty-three such receptors were studied. Five rapidly adapting receptors were also identified. 3. The responses of these receptors have been correlated with rib position and movement. The slowly adapting receptors gave a monotonic response to different rib positions. 72% showed an increase of discharge rate with displacements towards expiratory rib positions. 4. In response to manually imposed rib movements slowly adapting joint mechanoreceptors gave a dynamic response which was directly related to the velocity of the movement and adapted within 2 sec. The movements of breathing produced a corresponding alteration of the discharge frequency of the slowly adapting receptors. 5. Slowly adapting receptors were localized to the capsule of the costo-transverse joint by probing. They responded to increased intra-articular pressure with an increase of discharge rate and were silenced by intra-articular lignocaine, 0·4%. 6. Rapidly adapting joint mechanoreceptors responded to rib movement with a brief burst of discharges. 7. The rib joint mechanoreceptors signal rib joint position, and the direction and velocity of rib movement. It is suggested that these afferent discharges provide the basis for the perception of respiratory movements of the chest. The significance of these receptors to the `sense of effort' resulting from a resistance to breathing is discussed. PMID:5789947

Improving mechanical properties of maxillary complete dentures through a bioinspired engineering design.

PubMed

White, James A P; Bond, Ian P; Jagger, Daryll C

2011-01-01

This study investigated how ribbed design features, including palatal rugae, may be used to significantly improve the structural performance of a maxillary denture under load. A computer-aided design model of a generic maxillary denture, incorporating various rib features, was created and imported into a finite element analysis program. The denture and ribbed features were assigned the material properties of standard denture acrylic resin, and load was applied in two different ways: the first simulating a three-point flexural bend of the posterior section and the second simulating loading of the entire palatal region. To investigate the combined use of ribbing and reinforcement, the same simulations were repeated with the ribbed features having a Young modulus two orders of magnitude greater than denture acrylic resin. For a prescribed load, total displacements of tracking nodes were compared to those of a control denture (without ribbing) to assess relative denture rigidity. When subjected to flexural loading, an increase in rib depth was seen to result in a reduction of both the transverse displacement of the last molar and vertical displacement at the centerline. However, ribbed features assigned the material properties of denture acrylic resin require a depth that may impose on speech and bolus propulsion before significant improvements are observed. The use of ribbed features, when made from a significantly stiffer material (eg, fiber-reinforced polymer) and designed to mimic palatal rugae, offer an acceptable method of providing significant improvements in rigidity to a maxillary denture under flexural load.

Focusing through the rib cage for MR-guided transcostal FUS

NASA Astrophysics Data System (ADS)

Gao, J.; Volovick, A.; Pekelny, Y.; Huang, ZH.; Cochran, S.; Melzer, A.

2012-10-01

The rib cage presents a significant obstacle in transcostal focused ultrasound surgery (FUS). This paper proposes a geometric solution, based on central projection from the focus to identify transducer elements affected by ribs shadowing which should be switched off. Its effectiveness in phantom experiments and simulations is reported, and ways are discussed to further reduce energy deposition on the ribs while enhancing heating at the focus. A tissue-mimicking phantom with phantom of ribs was sonicated using a 208-element 1.15 MHz bowl transducer and a 1000-element 550 kHz planar matrix transducer (both ExAblate, InSightec, Israel). The temperature evolution was monitored with real-time MRI thermometry (GE, USA). Numerical simulations were performed with FEA software (PZFlex, Weidlinger Associates, USA) to investigate different skin-focus and transducer-rib distances. The temperature rise near the ribs was reduced to 16°C and 4°C for the 1.15 MHz and 550 kHz transducers respectively. With the 1.15 MHz transducer, the focal temperature reached the ablation threshold. These measurements are in good agreement with simulations. The proposed method shows promising results for transcostal FUS. Residual temperature rise on the ribs can be further reduced by active cooling, allowing the higher energies essential for efficient ablation.

[Analysis of 163 rib fractures by imaging examination].

PubMed

Song, Tian-fu; Wang, Chao-chao

2014-12-01

To explore the applications of imaging examination on rib fracture sites in forensic identification. Features including the sites, numbers of the processed imaging examination and the first radiological technology at diagnosis in 56 cases of rib fractures from 163 injuries were retrospectively analyzed. The detection rate of the rib fractures within 14 days was 65.6%. The initial detection rate of anterior rib fracture proceeded by X-ray was 76.2%, then 90.5% detected at a second time X-ray, while the detection rate of CT was 66.7% and 80.0%, respectively. The initial detec- tion rate of rib fracture in axillary section proceeded by X-ray was 27.6%, then 58.6% detected at a second time X-ray, while the detection rate of CT was 54.3% and 80.4%, respectively. The initial detection rate of posterior rib fracture proceeded by X-ray was 63.6%, then 81.8% detected at a second time X-ray, while the detection rate of CT was 50.0% and 70.0%, respectively. It is important to pay attention to the use of combined imaging examinations and the follow-up results. In the cases of suspicious for rib fracture in axillary section, CT examination is suggested in such false X-ray negative cases.

Concurrent rib and pelvic fractures as an indicator of solid abdominal organ injury.

PubMed

Al-Hassani, Ammar; Afifi, Ibrahim; Abdelrahman, Husham; El-Menyar, Ayman; Almadani, Ammar; Recicar, Jan; Al-Thani, Hassan; Maull, Kimball; Latifi, Rifat

2013-01-01

To study the association of solid organ injuries (SOIs) in patients with concurrent rib and pelvic fractures. Retrospective analysis of prospectively collected data from November 2007 to May 2010. Patients' demographics, mechanism of injury, Injury severity scoring, pelvic fracture, and SOIs were analyzed. Patients with SOIs were compared in rib fractures with and without pelvic fracture. The study included 829 patients (460 with rib fractures ± pelvic fracture and 369 with pelvic fracture alone) with mean age of 35 ± 12.7 years. Motor vehicle crashes (45%) and falls from height (30%) were the most common mechanism of injury. The overall incidence of SOIs in this study was 22% (185/829). Further, 15% of patient with rib fractures had associated pelvic fracture. SOI was predominant in patients with concurrent rib fracture and pelvic fracture compared to ribs or pelvic fractures alone (42% vs. 26% vs. 15%, respectively, p = 0.02). Concurrent multiple rib fractures and pelvic fracture increases the risk of SOI compared to either group alone. Lower RFs and pelvic fracture had higher association for SOI and could be used as an early indicator of the presence of SOIs. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

[Surgical fixation of rib fractures with clips and titanium bars (STRATOS System). Preliminary experience].

PubMed

Moreno De La Santa Barajas, Pablo; Polo Otero, María Dolores; Delgado Sánchez-Gracián, Carlos; Lozano Gómez, Manuel; Toscano Novella, Alberto; Calatayud Moscoso Del Prado, Julia; Leal Ruiloba, Sonsoles; Choren Durán, Maria L

2010-09-01

Rib fractures are very common in closed chest injuries. The majority of these patients suffer significant pain with movement and cough. The purpose of this study is to assess the usefulness of titanium rib bars and clips in stabilising rib fractures. Twenty-two patients with rib fractures were treated with open reduction and internal fixation between 2008 and 2009. Indications for treatment were defined as; 1) Patients with unstable chest (13 patients), 2) Patients with pain or instability due to rib fractures (6 patients), and 3) Significant traumatic deformities of the chest wall (3 patients). Age, traumatic mechanism, chest and associated injuries, surgical data, complications and follow-up were prospectively analysed. The surgical technique is described. The majority of patients were extubated immediately after surgery. All patients with pain or instability showed a subjective improvement or disappearance of pain after the surgery. Four patients had a wound infection which had to be drained. After 3 months, 55% of the patients had returned to work or normal life. The results in each group are described. Open reduction with internal fixation of rib fractures is a good alternative. The use of titanium rib bars and clips give good clinical results, are easy to apply and have few complications. Copyright © 2010 AEC. Published by Elsevier Espana. All rights reserved.

Improved oil-off survivability of tapered roller bearings

NASA Technical Reports Server (NTRS)

Kreider, Gary E.; Lee, Peter W.

1987-01-01

The aim of this program is to improve the oil-off survivability of a tapered roller bearing when applied to a helicopter transmission, since the tapered bearing has shown a performance advantage in this application. However, the critical roller end-rib conjunction is vulnerable to damage in an oil-off condition. Three powdered metal materials were selected to use as the rib material for oil-off evaluation. These were: M2 steel to a 65% density, CBS 1000M 65% density, and CBS 1000M 75% density. The bearing styles tested were ribbed cone (inner race) and ribbed cup (outer race). Carburized solid CBS 600 was also used as a ribbed material for comparison of oil-off results. The tests were conducted at six speeds from 4000 rpm (0.26 million DN) through 37000 rpm (2.4 million DN).The ribbed cup style bearing achieved longer lives than the ribbed cone style. A standard bearing lasted only 10 minutes at 4000 rpm; however, the 30-min oil-off goal was achieved through 11000 rpm using the survivable ribbed cup bearing. The oil-off lives at 37000 rpm were less than 10 seconds. The grinding of the powder metal materials and surface preparation to achieve an open porosity is extremely critical to the oil-off performance of the powder metal component.

The Epidemiological, Morphological, and Clinical Aspects of the Cervical Ribs in Humans

PubMed Central

Spadliński, Łukasz; Cecot, Tomasz; Majos, Agata; Stefańczyk, Ludomir; Pietruszewska, Wioletta; Wysiadecki, Grzegorz; Topol, Mirosław

2016-01-01

A familiarity with the anatomy of some types of bone anomalies is necessary for clinicians involved in many medical areas. The aim of this paper is to review the newest literature concerning the morphology, embryology, clinical image, and therapeutic methods of the cervical ribs in the humans. The incidence of cervical ribs has been found to vary from 0.58% in Malaysian population to 6.2% in Turkish population. Cervical ribs have clinical implications that are generally divided into neurological or vascular. This study is of particular importance for clinicians, as early identification of cervical ribs may prevent life-threatening complications. PMID:27975060

Multi-detector thoracic CT findings in cerebro-costo-mandibular syndrome: rib gaps and failure of costo-vertebral separation.

PubMed

Watson, Tom Anthony; Arthurs, Owen John; Muthialu, Nagarajan; Calder, Alistair Duncan

2014-02-01

Cerebro-costo-mandibular syndrome (CCMS) describes a triad of mandibular hypoplasia, brain dysfunction and posterior rib defects ("rib gaps"). We present the CT imaging for a 2-year-old girl with CCMS that highlights the rib gap defects and shows absent transverse processes with abnormal fusion of the ribs directly to the vertebral bodies. We argue that this is likely to relate to abnormal lateral sclerotome development in embryology, with the failure of normal costo-vertebral junctions compounding impaired thoracic function. The case also highlights the use of CT for specific indications in skeletal dysplasia.

A Surgical Procedure for Resecting the Mouse Rib: A Model for Large-Scale Long Bone Repair

PubMed Central

Funnell, John W.; Thein, Thu Zan Tun; Mariani, Francesca V.

2015-01-01

This protocol introduces researchers to a new model for large-scale bone repair utilizing the mouse rib. The procedure details the following: preparation of the animal for surgery, opening the thoracic body wall, exposing the desired rib from the surrounding intercostal muscles, excising the desired section of rib without inducing a pneumothorax, and closing the incisions. Compared to the bones of the appendicular skeleton, the ribs are highly accessible. In addition, no internal or external fixator is necessary since the adjacent ribs provide a natural fixation. The surgery uses commercially available supplies, is straightforward to learn, and well-tolerated by the animal. The procedure can be carried out with or without removing the surrounding periosteum, and therefore the contribution of the periosteum to repair can be assessed. Results indicate that if the periosteum is retained, robust repair occurs in 1 - 2 months. We expect that use of this protocol will stimulate research into rib repair and that the findings will facilitate the development of new ways to stimulate bone repair in other locations around the body. PMID:25651082

Flexural performance of steel fiber reinforced concrete (SFRC) ribbed slab with various topping thicknesses

NASA Astrophysics Data System (ADS)

Rahman, Fadhillah Abdul; Bakar, Afidah Abu; Hashim, Mohd Hisbany Mohd; Ahmad, Hazrina

2017-11-01

Ribbed slab provides lighter slab than an equivalent solid slab which helps in reducing the weight with its voids. However, in order to overcome the drawbacks in the construction process, the application of steel fibre reinforcement concrete (SFRC) is seen as an alternative material to be used in the slab. This study is performed to investigate the behaviour of SFRC as the main material in ribbed slab, omitting the conventional reinforcements, under four-point bending test. Three equivalent samples of ribbed slabs were prepared for this study with variations in the topping thickness of 100, 75 and 50 mm. The flexural strength of ribbed slab with 100 mm topping shows similar loading carrying capacity with the 75mm topping while 50 mm gave the lowest ultimate loading. First cracks for all slabs occurred at the topping. The cracks began from the external ribs and propagates toward the internal rib. Incorporation of steel fibres help in giving a longer deflection softening than a sudden brittle failure, thus proves its ability to increase energy absorption capacity and improving cracking behaviour.

Experimental investigation of the effect of variously-shaped ribs on local heat transfer on the outer wall of the turning portion of a U-channel inside solar air heater

NASA Astrophysics Data System (ADS)

Salameh, Tareq; Alami, Abdul Hai; Sunden, Bengt

2016-03-01

In the present work, an experimental investigation of convective heat transfer and pressure drop was carried out for the turning portion of a U-channel where the outer wall was equipped with ribs. The shape of the ribs was varied. The investigation aims to give guidelines for improving the thermo-hydraulic performance of a solar air heater at the turning portion of a U-channel. Both the U-channel and the ribs were made in acrylic material to allow optical access for measuring the surface temperature by using a high-resolution technique based on narrow band thermochromic liquid crystals (TLC R35C5 W) and a CCD camera placed to face the turning portion of the U-channel. The uncertainties were estimated to 5 and 7 % for the Nusselt number and friction factor, respectively. The pressure drop was approximately the same for all the considered shapes of the ribs while the dimpled rib case gave the highest heat transfer coefficient while the grooved rib presented the highest performance index.

A case of pathological rib fractures: focal osteolysis or osteoporosis?

PubMed

Vrbanić, T S L; Novak, S; Sestan, B; Tudor, A; Gulan, G

2008-03-01

This paper reports on a unique, previously unreported, successful outcome in the case of a patient with focal osteolytic lesions of the ribs as a first sign of osteoporosis. The lesions were detected by chance after acute cough-induced rib fractures were seen on plain chest radiographs. The diagnosis had to be approached as a diagnosis of exclusion since known causes of the osteolytic process had to be eliminated. The authors describe multiple focal osteolytic lesions with rib fractures appearing in a pattern that could be confused with metastases. Laboratory results were normal. Final diagnosis was based on plain radiography, bone scan and bone densitometry. Pharmacomedical treatments for osteoporosis were applied. The patient was observed between the year 2000 and 2005. Five years later radiological and bone scintigraphy revealed resolution of the lesion. We conclude that osteoporosis should be included in the differential diagnosis of asymptomatic focal osteolysis of the ribs with rib fractures as a complication of acute cough. The case suggests that focal osteolytic lesions of the ribs may regress over time and become scintigraphically inactive.

Heat transfer performance comparison of steam and air in gas turbine cooling channels with different rib angles

NASA Astrophysics Data System (ADS)

Shi, Xiaojun; Gao, Jianmin; Xu, Liang; Li, Fajin

2013-11-01

Using steam as working fluid to replace compressed air is a promising cooling technology for internal cooling passages of blades and vanes. The local heat transfer characteristics and the thermal performance of steam flow in wide aspect ratio channels ( W/ H = 2) with different angled ribs on two opposite walls have been experimentally investigated in this paper. The averaged Nusselt number ratios and the friction factor ratios of steam and air in four ribbed channels were also measured under the same test conditions for comparison. The Reynolds number range is 6,000-70,000. The rib angles are 90°, 60°, 45°, and 30°, respectively. The rib height to hydraulic diameter ratio is 0.047. The pitch-to-rib height ratio is 10. The results show that the Nusselt number ratios of steam are 1.19-1.32 times greater than those of air over the range of Reynolds numbers studied. For wide aspect ratio channels using steam as the coolant, the 60° angled ribs has the best heat transfer performance and is recommended for cooling design.

Compact waveguide circular polarizer

DOEpatents

Tantawi, Sami G.

2016-08-16

A multi-port waveguide is provided having a rectangular waveguide that includes a Y-shape structure with first top arm having a first rectangular waveguide port, a second top arm with second rectangular waveguide port, and a base arm with a third rectangular waveguide port for supporting a TE.sub.10 mode and a TE.sub.20 mode, where the end of the third rectangular waveguide port includes rounded edges that are parallel to a z-axis of the waveguide, a circular waveguide having a circular waveguide port for supporting a left hand and a right hand circular polarization TE.sub.11 mode and is coupled to a base arm broad wall, and a matching feature disposed on the base arm broad wall opposite of the circular waveguide for terminating the third rectangular waveguide port, where the first rectangular waveguide port, the second rectangular waveguide port and the circular waveguide port are capable of supporting 4-modes of operation.

Interconnect Between a Waveguide and a Dielectric Waveguide Comprising an Impedance Matched Dielectric Lens

NASA Technical Reports Server (NTRS)

Decrossas, Emmanuel (Inventor); Chattopadhyay, Goutam (Inventor); Chahat, Nacer (Inventor); Tang, Adrian J. (Inventor)

2016-01-01

A lens for interconnecting a metallic waveguide with a dielectric waveguide is provided. The lens may be coupled a metallic waveguide and a dielectric waveguide, and minimize a signal loss between the metallic waveguide and the dielectric waveguide.

RF window assembly comprising a ceramic disk disposed within a cylindrical waveguide which is connected to rectangular waveguides through elliptical joints

DOEpatents

Tantawi, Sami G.; Dolgashev, Valery A.; Yeremian, Anahid D.

2016-03-15

A high-power microwave RF window is provided that includes a cylindrical waveguide, where the cylindrical waveguide includes a ceramic disk concentrically housed in a central region of the cylindrical waveguide, a first rectangular waveguide, where the first rectangular waveguide is connected by a first elliptical joint to a proximal end of the cylindrical waveguide, and a second rectangular waveguide, where the second rectangular waveguide is connected by a second elliptical joint to a distal end of the cylindrical waveguide.

A study of general instability of box beams with truss-type ribs

NASA Technical Reports Server (NTRS)

Lundquist, Eugene E; Schwartz, Edward B

1942-01-01

The design of truss-type ribs for box beams is theoretically treated with regard to the function of the ribs in stabilizing the compression flange. The theory is applied to a design problem, and the results of this application are presented and discussed in relation to the general problem of rib design. The results of some tests made as a part of this general study are presented in an appendix.

Thoracic Injury Risk Curves for Rib Deflections of the SID-IIs Build Level D.

PubMed

Irwin, Annette L; Crawford, Greg; Gorman, David; Wang, Sikui; Mertz, Harold J

2016-11-01

Injury risk curves for SID-IIs thorax and abdomen rib deflections proposed for future NCAP side impact evaluations were developed from tests conducted with the SID-IIs FRG. Since the floating rib guide is known to reduce the magnitude of the peak rib deflections, injury risk curves developed from SID-IIs FRG data are not appropriate for use with SID-IIs build level D. PMHS injury data from three series of sled tests and one series of whole-body drop tests are paired with thoracic rib deflections from equivalent tests with SID-IIs build level D. Where possible, the rib deflections of SID-IIs build level D were scaled to adjust for differences in impact velocity between the PMHS and SID-IIs tests. Injury risk curves developed by the Mertz-Weber modified median rank method are presented and compared to risk curves developed by other parametric and non-parametric methods.

Costal cartilage fractures and disruptions in a rugby football player.

PubMed

Lopez, Victor; Ma, Richard; Li, Xinning; Steele, John; Allen, Answorth A

2013-05-01

Costal cartilage fracture of the rib cage, or costochondral, is a rare sporting injury. For contact athletes, the instability of the rib cage may lead to potential serious complications, similar to rib fractures or thorax disruption. Most authors recommend initial conservative treatment with surgery reserved for only recalcitrant cases. We report a case of an amateur American male rugby football player who sustained a costal cartilage fracture and disruption involving the anterior left fifth and sixth rib costal cartilages. The case highlights the difficulty in establishing the diagnosis based on clinical examination and standard radiographs alone. Computed tomography was used to assist in diagnosing this destabilizing injury to the rib cage. Costal cartilage fractures and disruptions in athletes are rarely reported in the literature and can have serious implications for the athlete's ability to return to play if the rib cage is destabilized.

[Internal fixation treatment of multiple rib fractures with absorbable rib-connecting-pins].

PubMed

Liu, Jinliang; Li, Keyao; He, Jianning

2011-01-01

To study the indications, methods, and therapeutic effect of absorbable rib-connecting-pins fixation in the treatment of multiple rib fractures. Between March 2007 and September 2009, 40 patients with multiple rib fractures received internal fixation with absorbable rib-connecting-pins, including 8 one-side flail chest and 1 two-side flail chest. There were 32 males and 8 females with an average age of 39.8 years (range, 25-72 years). The injury was caused by traffic accident in 32 cases, falling from height in 6 cases, and blunt hitting in 2 cases. Preoperatively, imaging data of the chest X-ray or spiral CT three-dimensional (3D) examination showed that all patients had multiple ribs fractures and displacement. The number of fractured ribs was 4-10 (median, 6), and the fracture location ranged from the 2nd to the 10th ribs. Of them, 28 cases were accompanied by hemathorax, pneumothorax or hemopneumothorax; 5 cases by thoracic organ injury; and 10 cases by other part trauma. The time from injury to hospitalization was less than 1 day in 26 cases, 1-3 days in 12 cases, and 3-6 days in 2 cases, and the time from hospitalization to operation was 3 hours to 3 days (mean, 1.2 days). The median fixation rib number was 5 (range, 3-8). The mean operative time, the time in bed, and hospitalization days were 32 minutes (range, 15-50 minutes), 4.5 days (range, 2-7 days), and 11.2 days (range, 5-18 days), respectively. All incisions healed by first intention. No pulmonary infection, pulmonary atelectasis, intrathoracic infection or other complications occurred. All cases were followed up 6-12 months (mean, 8 months). PaO2 [(86.6 +/- 2.2) mmHg (1 mm Hg = 0.133 kPa)] and SpO2 (97.2% +/- 0.6%) at 2 hours after operation were obviously improved when compared with preoperative ones (PaO2 (53.6 + 4.7) mm Hg and SpO2 (86.2% + 1.8%)], showing significant differences (t = 2.971, P = 0.005; t = 2.426, P = 0.020). The chest X-ray films or spiral CT 3D indicated that fracture of rib healed within 3-6 months (mean, 4.5 months) after operation. Severe collapsed chest wall or flail chest caused by fracture of multiple ribs should be treated by absorbable rib-connecting-pins, which is a simple, firm, and effective method.

Supersonic Wing Optimization Using SpaRibs

NASA Technical Reports Server (NTRS)

Locatelli, David; Mulani, Sameer B.; Liu, Qiang; Tamijani, Ali Y.; Kapania, Rakesh K.

2014-01-01

This research investigates the advantages of using curvilinear spars and ribs, termed SpaRibs, to design a supersonic aircraft wing-box in comparison to the use of classic design concepts that employ straight spars and ribs. The objective is to achieve a more efficient load-bearing mechanism and to passively control the deformation of the structure under the flight loads. Moreover, the use of SpaRibs broadens the design space and allows for natural frequencies and natural mode shape tailoring. The SpaRibs concept is implemented in a new optimization MATLAB-based framework referred to as EBF3SSWingOpt. This optimization scheme performs both the sizing and the shaping of the internal structural elements, connecting the optimizer with the analysis software. The shape of the SpaRibs is parametrically defined using the so called Linked Shape method. Each set of SpaRibs is placed in a one by one square domain of the natural space. The set of curves is subsequently transformed in the physical space for creating the wing structure geometry layout. The shape of each curve of each set is unique; however, mathematical relations link the curvature in an effort to reduce the number of design variables. The internal structure of a High Speed Commercial Transport aircraft concept developed by Boeing is optimized subjected to stress, subsonic flutter and supersonic flutter constraints. The results show that the use of the SpaRibs allows for the reduction of the aircraft's primary structure weight without violating the constraints. A weight reduction of about 15 percent is observed.

Use of a 90° drill and screwdriver for rib fracture stabilization.

PubMed

Nickerson, Terry P; Kim, Brian D; Zielinski, Martin D; Jenkins, Donald; Schiller, Henry J

2015-03-01

Rib fracture stabilization has become a more accepted practice although stabilization of the most cephalad ribs presents a unique challenge. We present our experience with use of a 90° drill and screwdriver to bridge these difficult rib fractures. This retrospective review included patients who underwent rib fracture stabilization from August 1, 2009, through September 30, 2012. Patients were divided into two groups: those whose procedure used the 90° device and those that did not. Data were compared using standard statistical analysis and reported as percentages and medians [interquartile ranges]. P values <0.05 were considered significant. We identified 89 patients: 29 (33%) had 90° devices used and 60 (67%) did not. There were no differences between groups in age, sex, Trauma-Related Injury Severity Score, the presence of flail chest, occurrence of pneumonia, and intensive care unit or hospital length of stay. The Injury Severity Score was higher in the 90° group (22 vs. 16; P = 0.03). The highest rib stabilized was different between the 2 groups (3 [2-5] vs. 5 [2-9]; P = 0.001), with more third rib stabilizations in the 90° group (38 vs. 20%; P = 0.04) as well as more total number of ribs fixed (5 vs. 4; P = 0.001). There was no difference in operative time between the 2 groups. The surgical reach for rib fracture stabilization has been extended with use of a 90° drill and screwdriver. High fractures under the scapula where access is technically challenging can be stabilized without prolonging operative times.

New bone post-processing tools in forensic imaging: a multi-reader feasibility study to evaluate detection time and diagnostic accuracy in rib fracture assessment.

PubMed

Glemser, Philip A; Pfleiderer, Michael; Heger, Anna; Tremper, Jan; Krauskopf, Astrid; Schlemmer, Heinz-Peter; Yen, Kathrin; Simons, David

2017-03-01

The aim of this multi-reader feasibility study was to evaluate new post-processing CT imaging tools in rib fracture assessment of forensic cases by analyzing detection time and diagnostic accuracy. Thirty autopsy cases (20 with and 10 without rib fractures in autopsy) were randomly selected and included in this study. All cases received a native whole body CT scan prior to the autopsy procedure, which included dissection and careful evaluation of each rib. In addition to standard transverse sections (modality A), CT images were subjected to a reconstruction algorithm to compute axial labelling of the ribs (modality B) as well as "unfolding" visualizations of the rib cage (modality C, "eagle tool"). Three radiologists with different clinical and forensic experience who were blinded to autopsy results evaluated all cases in a random manner of modality and case. Rib fracture assessment of each reader was evaluated compared to autopsy and a CT consensus read as radiologic reference. A detailed evaluation of relevant test parameters revealed a better accordance to the CT consensus read as to the autopsy. Modality C was the significantly quickest rib fracture detection modality despite slightly reduced statistic test parameters compared to modalities A and B. Modern CT post-processing software is able to shorten reading time and to increase sensitivity and specificity compared to standard autopsy alone. The eagle tool as an easy to use tool is suited for an initial rib fracture screening prior to autopsy and can therefore be beneficial for forensic pathologists.

Prevalence of Abuse Among Young Children with Rib Fractures: A Systematic Review

PubMed Central

Paine, Christine Weirich; Fakeye, Oludolapo; Christian, Cindy W.; Wood, Joanne N.

2016-01-01

Objectives We aimed to estimate the prevalence of abuse in young children presenting with rib fractures and to identify demographic, injury, and presentation-related characteristics that affect the probability that rib fractures are secondary to abuse. Methods We searched PubMed/MEDLINE and CINAHL databases for articles published in English between January 1, 1990 and June 30, 2014 on rib fracture etiology in children ≤ 5 years old. Two reviewers independently extracted predefined data elements and assigned quality ratings to included studies. Study-specific abuse prevalences and the sensitivities, specificities, and positive and negative likelihood ratios of patients’ demographic and clinical characteristics for abuse were calculated with 95% confidence intervals. Results Data for 1,396 children ≤ 48 months old with rib fractures were abstracted from 10 articles. Among infants < 12 months old, abuse prevalence ranged from 67% to 84%, whereas children 12-23 months old and 24-35 months old had study-specific abuse prevalences of 29% and 28% respectively. Age < 12 months was the only characteristic significantly associated with increased likelihood of abuse across multiple studies. Rib fracture location was not associated with likelihood of abuse. The retrospective design of the included studies and variations in ascertainment of cases, inclusion/exclusion criteria, and child abuse assessments prevented further meta-analysis. Conclusions Abuse is the most common cause of rib fractures in infants < 12 months old. Prospective studies with standardized methods are needed to improve accuracy in determining abuse prevalence among children with rib fractures and characteristics associated with abusive rib fractures. PMID:27749806

Outcomes after operative management of symptomatic rib nonunion.

PubMed

Gauger, Erich M; Hill, Brian W; Lafferty, Paul M; Cole, Peter A

2015-06-01

To report the outcomes of rib reconstruction after painful nonunion. Retrospective case series. Level I trauma center. Between November 2007 and May 2013, 10 patients who presented with 16 rib nonunions and disabling pain were treated with reconstruction of their nonunited rib fractures. Rib nonunion reconstruction predominately with iliac crest bone graft and a tension band plate with a locked precontoured plating system for ribs. Demographic data, mechanism of injury, and number of rib nonunions were recorded. Operative procedure, length of follow-up, complications, Short Form Survey 36, and a patient questionnaire were also captured and documented. Eight of the 10 patients sustained their original fractures from a fall. Outcomes were available for the 10 patients at a mean follow-up of up of 18.6 months (range, 3-46 months). All 16 ribs went on to union with a mean time from reconstruction to union of 14.7 weeks (range, 12-24 weeks). At final follow-up, the mean mental and physical component Short Form Survey 36 scores were 54.4 and 43.5, respectively. Eight of the 10 patients were able to return to work and/or previous activities without limitations. Complications included 1 wound infection that resolved after irrigation and debridement with adjunctive antibiotics. One symptomatic implant was removed. Ten patients with 16 symptomatic rib nonunions were reconstructed using autologous bone graft and implant/mesh fixation manifesting in successful union with improved patient function and a low rate of complications. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

21. Detail of steel ribs at south wall, T18; Note ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. Detail of steel ribs at south wall, T-18; Note composition of ribs--two steel channels welded together - Advance Base Depot Davisville, Building T-17, Ninth Street southeast of Davisville Road, Davisville, Washington County, RI

Clinical prognostic factors and grading system for rib fracture following stereotactic body radiation therapy (SBRT) in patients with peripheral lung tumors.

PubMed

Kim, Su Ssan; Song, Si Yeol; Kwak, Jungwon; Ahn, Seung Do; Kim, Jong Hoon; Lee, Jung Shin; Kim, Woo Sung; Kim, Sang-We; Choi, Eun Kyung

2013-02-01

Several studies reported rib fractures following stereotactic body radiation therapy (SBRT) for peripheral lung tumors. We tried to investigate risk factors and grading system for rib fractures after SBRT. Of 375 primary or metastatic lung tumors (296 patients) which were treated with SBRT at the Asan Medical Center (2006-2009), 126 lesions (118 patients) were adjacent to the chest-wall (<1cm) and followed-up with chest computed tomography (CT) for >6 months; these were investigated in the present retrospective study. Three to four fractional doses of 10-20 Gy were delivered to 85-90% iso-dose volume of the isocenter dose. Rib fracture grade was defined from follow-up CT scans as the appearance of a fracture line (Gr1), dislocation of the fractured rib by more than half the rib diameter (Gr2), or the appearance of adjacent soft tissue edema (Gr3). Chest wall pain was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v3.0. Correlations between dose-volume data and the development of rib fracture were then analyzed. The Kaplan-Meier method, log-rank tests, and chi-square tests were used for statistical analysis. The median age of the patients was 69 years (range: 19-90). Over a median follow-up period of 22 months (range: 7-62), 48 cases of rib fracture were confirmed. Median time to rib fracture was 17 months (range: 4-52). The 2-year actuarial risk of rib fracture was 42.4%. Maximal grade was Gr1 (n=28), Gr2 (n=8), or Gr3 (n=15). The incidence of moderate to severe chest wall pain (CTCAE Gr ≥ 2) increased with maximal fracture grade (17.5% for Gr0-1 and 60.9% for Gr2-3; p<0.001). Multivariate analysis identified female gender, lateral location, and the dose to the 8cc of the chest wall as significant prognostic factors. Female gender and lateral tumor location were clinical risk factors for rib fracture in the present study. Efforts to decrease chest wall dose should be made to reduce the risk of the rib fracture, particularly in high-risk patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Systemic administration of mesenchymal stem cells combined with parathyroid hormone therapy synergistically regenerates multiple rib fractures.

PubMed

Cohn Yakubovich, Doron; Sheyn, Dmitriy; Bez, Maxim; Schary, Yeshai; Yalon, Eran; Sirhan, Afeef; Amira, May; Yaya, Alin; De Mel, Sandra; Da, Xiaoyu; Ben-David, Shiran; Tawackoli, Wafa; Ley, Eric J; Gazit, Dan; Gazit, Zulma; Pelled, Gadi

2017-03-09

A devastating condition that leads to trauma-related morbidity, multiple rib fractures, remain a serious unmet clinical need. Systemic administration of mesenchymal stem cells (MSCs) has been shown to regenerate various tissues. We hypothesized that parathyroid hormone (PTH) therapy would enhance MSC homing and differentiation, ultimately leading to bone formation that would bridge rib fractures. The combination of human MSCs (hMSCs) and a clinically relevant PTH dose was studied using immunosuppressed rats. Segmental defects were created in animals' fifth and sixth ribs. The rats were divided into four groups: a negative control group, in which animals received vehicle alone; the PTH-only group, in which animals received daily subcutaneous injections of 4 μg/kg teriparatide, a pharmaceutical derivative of PTH; the hMSC-only group, in which each animal received five injections of 2 × 10 6 hMSCs; and the hMSC + PTH group, in which animals received both treatments. Longitudinal in vivo monitoring of bone formation was performed biweekly using micro-computed tomography (μCT), followed by histological analysis. Fluorescently-dyed hMSCs were counted using confocal microscopy imaging of histological samples harvested 8 weeks after surgery. PTH significantly augmented the number of hMSCs that homed to the fracture site. Immunofluorescence of osteogenic markers, osteocalcin and bone sialoprotein, showed that PTH induced cell differentiation in both exogenously administered cells and resident cells. μCT scans revealed a significant increase in bone volume only in the hMSC + PTH group, beginning by the 4 th week after surgery. Eight weeks after surgery, 35% of ribs in the hMSC + PTH group had complete bone bridging, whereas there was complete bridging in only 6.25% of ribs (one rib) in the PTH-only group and in none of the ribs in the other groups. Based on the μCT scans, biomechanical analysis using the micro-finite element method demonstrated that the healed ribs were stiffer than intact ribs in torsion, compression, and bending simulations, as expected when examining bone callus composed of woven bone. Administration of both hMSCs and PTH worked synergistically in rib fracture healing, suggesting this approach may pave the way to treat multiple rib fractures as well as additional fractures in various anatomical sites.

Measuring Three-Dimensional Thorax Motion Via Biplane Radiographic Imaging: Technique and Preliminary Results.

PubMed

Baumer, Timothy G; Giles, Joshua W; Drake, Anne; Zauel, Roger; Bey, Michael J

2016-01-01

Measures of scapulothoracic motion are dependent on accurate imaging of the scapula and thorax. Advanced radiographic techniques can provide accurate measures of scapular motion, but the limited 3D imaging volume of these techniques often precludes measurement of thorax motion. To overcome this, a thorax coordinate system was defined based on the position of rib pairs and then compared to a conventional sternum/spine-based thorax coordinate system. Alignment of the rib-based coordinate system was dependent on the rib pairs used, with the rib3:rib4 pairing aligned to within 4.4 ± 2.1 deg of the conventional thorax coordinate system.

Successful management of threatened aortic rupture late after rib fracture caused by blunt chest trauma.

PubMed

Morimoto, Yoshihisa; Sugimoto, Takaki; Sakahira, Hideki; Matsuoka, Hidehito; Yoshioka, Yuki; Arase, Hiroki

2014-05-01

A 62-year-old man was crushed in a car accident and diagnosed with a fractured left ninth rib, pulmonary and heart contusion, hemopneumothorax, and descending aortic injury based on a computed tomography scan. He underwent chest tube drainage and was intubated for mechanical ventilation because a bone fragment of the ninth rib threatened to penetrate the descending aorta. On the second posttrauma day, computed tomography showed the bone fragment of the ninth rib approaching the descending aorta. He underwent graft replacement of the injured portion of the descending thoracic aorta, and we removed the fractured left ninth rib. Copyright © 2014 Elsevier Inc. All rights reserved.

A Rare Entity: Bilateral First Rib Fractures Accompanying Bilateral Scapular Fractures.

PubMed

Gulbahar, Gultekin; Kaplan, Tevfik; Turker, Hasan Bozkurt; Gundogdu, Ahmet Gokhan; Han, Serdar

2015-01-01

First rib fractures are scarce due to their well-protected anatomic locations. Bilateral first rib fractures accompanying bilateral scapular fractures are very rare, although they may be together with scapular and clavicular fractures. According to our knowledge, no case of bilateral first rib fractures accompanying bilateral scapular fractures has been reported, so we herein discussed the diagnosis, treatment, and complications of bone fractures due to thoracic trauma in bias of this rare entity.

A Rare Entity: Bilateral First Rib Fractures Accompanying Bilateral Scapular Fractures

PubMed Central

Gulbahar, Gultekin; Kaplan, Tevfik; Turker, Hasan Bozkurt; Gundogdu, Ahmet Gokhan; Han, Serdar

2015-01-01

First rib fractures are scarce due to their well-protected anatomic locations. Bilateral first rib fractures accompanying bilateral scapular fractures are very rare, although they may be together with scapular and clavicular fractures. According to our knowledge, no case of bilateral first rib fractures accompanying bilateral scapular fractures has been reported, so we herein discussed the diagnosis, treatment, and complications of bone fractures due to thoracic trauma in bias of this rare entity. PMID:26175916

Electromagnetic Inverse Methods and Applications for Inhomogeneous Media Probing and Synthesis.

NASA Astrophysics Data System (ADS)

Xia, Jake Jiqing

The electromagnetic inverse scattering problems concerned in this thesis are to find unknown inhomogeneous permittivity and conductivity profiles in a medium from the scattering data. Both analytical and numerical methods are studied in the thesis. The inverse methods can be applied to geophysical medium probing, non-destructive testing, medical imaging, optical waveguide synthesis and material characterization. An introduction is given in Chapter 1. The first part of the thesis presents inhomogeneous media probing. The Riccati equation approach is discussed in Chapter 2 for a one-dimensional planar profile inversion problem. Two types of the Riccati equations are derived and distinguished. New renormalized formulae based inverting one specific type of the Riccati equation are derived. Relations between the inverse methods of Green's function, the Riccati equation and the Gel'fand-Levitan-Marchenko (GLM) theory are studied. In Chapter 3, the renormalized source-type integral equation (STIE) approach is formulated for inversion of cylindrically inhomogeneous permittivity and conductivity profiles. The advantages of the renormalized STIE approach are demonstrated in numerical examples. The cylindrical profile inversion problem has an application for borehole inversion. In Chapter 4 the renormalized STIE approach is extended to a planar case where the two background media are different. Numerical results have shown fast convergence. This formulation is applied to inversion of the underground soil moisture profiles in remote sensing. The second part of the thesis presents the synthesis problem of inhomogeneous dielectric waveguides using the electromagnetic inverse methods. As a particular example, the rational function representation of reflection coefficients in the GLM theory is used. The GLM method is reviewed in Chapter 5. Relations between modal structures and transverse reflection coefficients of an inhomogeneous medium are established in Chapter 6. A stratified medium model is used to derive the guidance condition and the reflection coefficient. Results obtained in Chapter 6 provide the physical foundation for applying the inverse methods for the waveguide design problem. In Chapter 7, a global guidance condition for continuously varying medium is derived using the Riccati equation. It is further shown that the discrete modes in an inhomogeneous medium have the same wave vectors as the poles of the transverse reflection coefficient. An example of synthesizing an inhomogeneous dielectric waveguide using a rational reflection coefficient is presented. A summary of the thesis is given in Chapter 8. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.).

Intercostal high intensity focused ultrasound for liver ablation: The influence of beam shaping on sonication efficacy and near-field risks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greef, M. de, E-mail: m.degreef@umcutrecht.nl; Wijlemans, J. W.; Bartels, L. W.

2015-08-15

Purpose: One of the major issues in high intensity focused ultrasound ablation of abdominal lesions is obstruction of the ultrasound beam by the thoracic cage. Beam shaping strategies have been shown by several authors to increase focal point intensity while limiting rib exposure. However, as rib obstruction leaves only part of the aperture available for energy transmission, conserving total emitted acoustic power, the intensity in the near-field tissues inherently increases after beam shaping. Despite of effective rib sparing, those tissues are therefore subjected to increased risk of thermal damage. In this study, for a number of clinically representative intercostal sonicationmore » geometries, modeling clinically available hardware, the effect of beam shaping on both the exposure of the ribs and near-field to acoustic energy was evaluated and the implications for the volumetric ablation rate were addressed. Methods: A relationship between rib temperature rise and acoustic energy density was established by means of in vivo MR thermometry and simulations of the incident acoustic energy for the corresponding anatomies. This relationship was used for interpretation of rib exposure in subsequent numerical simulations in which rib spacing, focal point placement, and the focal point trajectory were varied. The time required to heat a targeted region to 65 °C was determined without and with the application of beam shaping. The required sonication time was used to calculate the acoustic energy density at the fat–muscle interface and at the surface of the ribs. At the fat–muscle interface, exposure was compared to available literature data and rib exposure was interpreted based on the earlier obtained relation between measured temperature rise and simulated acoustic energy density. To estimate the volumetric ablation rate, the cool-down time between periods of energy exposure was estimated using a time-averaged power limit of 100 kJ/h. Results: At the level of the ribs, the temperature rise–energy density proportionality constant was estimated to be 6.0–7.6 °C/(J/mm{sup 2}). Beam shaping by the geometric shadow method typically reduces the acoustic intensity a factor of 2, considering the 1 cm{sup 2} with the highest exposure. For a 4 mm diameter circular sonication trajectory, the near-field energy limit of 2.5 J/mm{sup 2} was exceeded for all considered geometries. The estimated rib temperature was in all but one (sonication 50 mm behind the ribs, with 15 mm rib spacing and a 4 mm diameter circular sonication trajectory) of the considered scenarios within acceptable limits. For those sonication scenarios where a single sonication is considered safe both in terms of near-field as well as rib heating, volumetric ablation rates in the order of 1 ml/h are estimated. Conclusions: Intercostal sonication is associated with an increased risk of near-field overheating. This risk is strongly dependent on the considered rib spacing, the placement of the focus behind the ribs, and the selected sonication trajectory. For the hardware under simulation, obstruction by the thoracic cage renders ablations of clinically relevant volumes within a practical time-frame unfeasible in a large part of the liver. Improvements maybe expected from transducer designs with a larger active surface and/or nonlinear sonication strategies.« less

Method and apparatus for monitoring the thickness of a coal rib during rib formation

DOEpatents

Mowrey, Gary L.; Ganoe, Carl W.; Monaghan, William D.

1996-01-01

Apparatus for monitoring the position of a mining machine cutting a new entry in a coal seam relative to an adjacent, previously cut entry to determine the distance between a near face of the adjacent previously cut entry and a new face adjacent thereto of a new entry being cut by the mining machine which together define the thickness of a coal rib being formed between the new entry and the adjacent previously cut entry during the new entry-cutting operation. The monitoring apparatus; includes a transmit antenna mounted on the mining machine and spaced inwardly from the new face of the coal rib for transmitting radio energy towards the coal rib so that one portion of the radio energy is reflected by the new face which is defined at an air-coal interface between the new entry and the coal rib and another portion of the radio energy is reflected by the near face of the coal rib which is defined at an air-coal interface between the coal rib and the adjacent previously cut entry. A receive antenna mounted on the mining machine and spaced inwardly of the new face of the coal rib receives the one portion of the radio energy reflected by the new face and also receives the another portion of the radio energy reflected by the near face. A processor determines a first elapsed time period equal to the time required for the one portion of the radio energy reflected by the new face to travel between the transmit antenna and the receive antenna and also determines a second elapsed time period equal to the time required for the another portion of the radio energy reflected by the near face to travel between the transmit antenna and the receive antenna and thereafter calculates the thickness of the coal rib being formed as a function of the difference between the first and second elapsed time periods.

Rib fractures under anterior-posterior dynamic loads: experimental and finite-element study.

PubMed

Li, Zuoping; Kindig, Matthew W; Kerrigan, Jason R; Untaroiu, Costin D; Subit, Damien; Crandall, Jeff R; Kent, Richard W

2010-01-19

The purpose of this study was to investigate whether using a finite-element (FE) mesh composed entirely of hexahedral elements to model cortical and trabecular bone (all-hex model) would provide more accurate simulations than those with variable thickness shell elements for cortical bone and hexahedral elements for trabecular bone (hex-shell model) in the modeling human ribs. First, quasi-static non-injurious and dynamic injurious experiments were performed using the second, fourth, and tenth human thoracic ribs to record the structural behavior and fracture tolerance of individual ribs under anterior-posterior bending loads. Then, all-hex and hex-shell FE models for the three ribs were developed using an octree-based and multi-block hex meshing approach, respectively. Material properties of cortical bone were optimized using dynamic experimental data and the hex-shell model of the fourth rib and trabecular bone properties were taken from the literature. Overall, the reaction force-displacement relationship predicted by both all-hex and hex-shell models with nodes in the offset middle-cortical surfaces compared well with those measured experimentally for all the three ribs. With the exception of fracture locations, the predictions from all-hex and offset hex-shell models of the second and fourth ribs agreed better with experimental data than those from the tenth rib models in terms of reaction force at fracture (difference <15.4%), ultimate failure displacement and time (difference <7.3%), and cortical bone strains. The hex-shell models with shell nodes in outer cortical surfaces increased static reaction forces up to 16.6%, compared to offset hex-shell models. These results indicated that both all-hex and hex-shell modeling strategies were applicable for simulating rib responses and bone fractures for the loading conditions considered, but coarse hex-shell models with constant or variable shell thickness were more computationally efficient and therefore preferred. Copyright 2009 Elsevier Ltd. All rights reserved.

Multiple Rib Nonunion: Open Reduction and Internal Fixation and Iliac Crest Bone Graft Aspirate.

PubMed

Kaplan, Daniel J; Begly, John; Tejwani, Nirmal

2017-08-01

Rib fractures are a common chest injury that can typically be treated nonoperatively. However, a percentage of these will go on to nonunion, either because of unique characteristics of the fracture itself or because of a variety of poor healing factors of the host. If a patient has continued symptomology beyond 3 months, surgeons may consider operative management. Although isolated resection of fibrous scar tissue from the nonunion site may be sufficient in some cases, it may also be necessary to provide additional structural integrity to the rib depending on the extent of the fracture pattern and resection. This goal can be achieved operatively with rib plating and bone grafting to promote healing. This video demonstrates the use of plating in the treatment of rib nonunion. It begins with relevant background information on rib fractures and nonunions, then details the approach, open reduction and internal fixation of 3 ribs using plates and bone graft aspirate. Pearls and pitfalls are included during the surgical technique aspect of the video to both help guide surgeons new to the procedure and provide potentially advantageous technical details to more experienced surgeons.

Chest wall stabilization in trauma patients: why, when, and how?

PubMed Central

White, Thomas W.

2018-01-01

Blunt trauma to the chest wall and rib fractures are remarkably frequent and are the basis of considerable morbidity and possible mortality. Surgical remedies for highly displaced rib fractures, especially in cases of flail chest, have been undertaken intermittently for more than 50 years. Rib-specific plating systems have started to be used in the last 10 years. These have ushered in the modern era of rib repair with chest wall stabilization (CWS) techniques that are safer, easier to perform, and more efficient. Recent consensus statements have sought to define the indications and contraindications, as well as the when, the how, and the technical details of CWS. Repair should be considered for patients who have three or more displaced rib fractures or a flail chest, whether or not mechanical ventilation is required. Additional candidates include patients who fail non-operative management irrespective of fracture pattern and those with rib fractures who need thoracic procedures for other reasons. Traditionally, unstable spine fracture and severe traumatic brain injury are definite contraindications. Pulmonary contusion’s role in the decision to perform CWS remains controversial. A range of rib-specific plating systems are now commercially available. PMID:29744222

Analysis of the Shear Behavior of Stubby Y-Type Perfobond Rib Shear Connectors for a Composite Frame Structure.

PubMed

Kim, Sang-Hyo; Kim, Kun-Soo; Lee, Do-Hoon; Park, Jun-Seung; Han, Oneil

2017-11-22

Shear connectors are used in steel beam-concrete slabs of composite frame and bridge structures to transfer shear force according to design loads. The existing Y-type perfobond rib shear connectors are designed for girder slabs of composite bridges. Therefore, the rib and transverse rebars of the conventional Y-type perfobond rib shear connectors are extremely large for the composite frames of building structures. Thus, this paper proposes stubby Y-type perfobond rib shear connectors, redefining the existing connectors, for composite frames of building structures; these were used to perform push-out tests. These shear connectors have relatively small ribs compared to the conventional Y-type perfobond rib shear connectors. To confirm the shear resistance of these stubby shear connectors, we performed an experiment by using transverse rebars D13 and D16. The results indicate that these shear connectors have suitable shear strength and ductility for application in composite frame structures. The shear strengths obtained using D13 and D16 were not significantly different. However, the ductility of the shear connectors with D16 was 45.1% higher than that of the shear connectors with D13.

The respective effect of under-rib convection and pressure drop of flow fields on the performance of PEM fuel cells.

PubMed

Wang, Chao; Zhang, Qinglei; Shen, Shuiyun; Yan, Xiaohui; Zhu, Fengjuan; Cheng, Xiaojing; Zhang, Junliang

2017-03-02

The flow field configuration plays an important role on the performance of proton exchange membrane fuel cells (PEMFCs). For instance, channel/rib width and total channel cross-sectional area determine the under-rib convection and pressure drop respectively, both of which directly influence the water removal, in turn affecting the oxygen supply and cathodic oxygen reduction reaction. In this study, effects of under-rib convection and pressure drop on cell performance are investigated experimentally and numerically by adjusting the channel/rib width and channel cross-sectional area of flow fields. The results show that the performance differences with various flow field configurations mainly derive from the oxygen transport resistance which is determined by the water accumulation degree, and the cell performance would benefit from the narrower channels and smaller cross sections. It reveals that at low current densities when water starts to accumulate in GDL at under-rib regions, the under-rib convection plays a more important role in water removal than pressure drop does; in contrast, at high current densities when water starts to accumulate in channels, the pressure drop dominates the water removal to facilitate the oxygen transport to the catalyst layer.

The respective effect of under-rib convection and pressure drop of flow fields on the performance of PEM fuel cells

NASA Astrophysics Data System (ADS)

Wang, Chao; Zhang, Qinglei; Shen, Shuiyun; Yan, Xiaohui; Zhu, Fengjuan; Cheng, Xiaojing; Zhang, Junliang

2017-03-01

The flow field configuration plays an important role on the performance of proton exchange membrane fuel cells (PEMFCs). For instance, channel/rib width and total channel cross-sectional area determine the under-rib convection and pressure drop respectively, both of which directly influence the water removal, in turn affecting the oxygen supply and cathodic oxygen reduction reaction. In this study, effects of under-rib convection and pressure drop on cell performance are investigated experimentally and numerically by adjusting the channel/rib width and channel cross-sectional area of flow fields. The results show that the performance differences with various flow field configurations mainly derive from the oxygen transport resistance which is determined by the water accumulation degree, and the cell performance would benefit from the narrower channels and smaller cross sections. It reveals that at low current densities when water starts to accumulate in GDL at under-rib regions, the under-rib convection plays a more important role in water removal than pressure drop does; in contrast, at high current densities when water starts to accumulate in channels, the pressure drop dominates the water removal to facilitate the oxygen transport to the catalyst layer.

Regional Variation in the Structural Response and Geometrical Properties of Human Ribs

PubMed Central

Cormier, Joseph M.; Stitzel, Joel D.; Duma, Stefan M.; Matsuoka, Fumio

2005-01-01

By incorporating material and geometrical properties into a model of the human thorax one can develop an injury criterion that is a function of stress and strain of the material and not a function of the global response of the thorax. Previous research on the mechanical properties of ribs has focused on a limited set of specific ribs. For this study a total of 52 rib specimens were removed from four cadaver subjects. Variation in peak moment by thoracic region was significant (p < 0.01) with average values of 2, 2.9 and 3.9 N-m for the anterior, lateral and posterior regions respectively. Two geometrical properties, radius of gyration and distance from the neutral axis, showed significant variation by region (p < 0.0001) as well as by rib level (p = < 0.01, 0.05). The results of this study can be used to update current models of the human thorax to account for the variation in strength and geometrical properties throughout the rib cage. Accounting for the variation in rib properties by region will improve injury predictive measures and, therefore, the ability to design systems to prevent thoracic injury. PMID:16179146

Looking for Speed!! Go Optical Ultra-Fast Photonic Logic Gates for the Future Optical Communication and Computing

NASA Technical Reports Server (NTRS)

Abdeldayem, Hossin; Frazier, Donald O.; Penn, Benjamin; Paley, Mark S.

2003-01-01

Recently, we developed two ultra-fast all-optical switches in the nanosecond and picosecond regimes. The picosecond switch is made of a polydiacetylene thin film coated on the interior wall of a hollow capillary of approximately 50 micron diameter by a photo-polymerization process. In the setup a picosecond Nd:YAG laser at 10 Hz and at 532 nm with a pulse duration of approximately 40 ps was sent collinearly along a cw He-Ne laser beam and both were waveguided through the hollow capillary. The setup functioned as an Exclusive OR gate. On the other hand, the material used in the nanosecond switch is a phthalocyanine thin film, deposited on a glass substrate by a vapor deposition technique. In the setup a nanosecond, 10 Hz, Nd:YAG laser of 8 ns pulse duration was sent collinearly along a cw He-Ne laser beam and both were wave-guided through the phthalocyanine thin film. The setup in this case functioned as an all-optical AND logic gate. The characteristic table of the ExOR gate in polydiacetylene film was attributed to an excited state absorption process, while that of the AND gate was attributed to a saturation process of the first excited state. Both mechanisms were thoroughly investigated theoretically and found to agree remarkably well with the experimental results. An all-optical inverter gate has been designed but has not yet been demonstrated. The combination of all these three gates form the foundation for building all the necessary gates needed to build a prototype of an all-optical system.

CT measured normative cartilage growth in children requiring costochondral grafting.

PubMed

Andreoli, Steven M; Mills, Jared C; Kilpatrick, Lauren A; White, David R; Patel, Krishna G

2013-12-01

Careful operative timing is required for children undergoing microtia repair using autologous costochondral grafting. This operation is performed as early as age 6 in efforts to treat children before school matriculation while allowing for sufficient rib growth. There remains a paucity of data regarding cartilaginous growth of the ribs and synchondrosis routinely harvested during microtia repair. This study employs CT imaging to generate normative costochondral growth characteristics in children. A population-based study was performed. Tertiary care children's hospital. Chest CTs were reviewed in 360 children ages 3 to 20 years. Measurements included: length of ribs 6, 7, and 8 and the height and width of the synchondrosis between ribs 6 and 7. Growth charts are presented for gender and laterality. At age 6: ribs 6, 7, and 8 measure 5.96 ± 0.69, 7.79 ± 0.84, and 6.33 ± 1.01 cm, respectively. In adulthood the mean length of ribs 6, 7, and 8 are 8.29 ± 1.00, 11.10 ± 1.19, and 8.95 ± 1.99 cm, respectively. The vertical height of the synchondrosis at years 6 and 20 are 2.42 ± 0.39 and 3.59 ± 0.53 cm, respectively. Ribs 6, 7, and 8 as well as the synchondrosis grow in a nearly linear fashion. Cartilaginous growth of ribs 6 to 8 during early childhood is nearly linear. Synchondrosis height approaches adult auricle width at 8 years. Rib size is consistently larger in males and on the left side. These data are useful for the pediatric otolaryngologist and facial plastics and reconstructive surgeon performing microtia surgery.

Lower thoracic rib stress fractures in baseball pitchers.

PubMed

Gerrie, Brayden J; Harris, Joshua D; Lintner, David M; McCulloch, Patrick C

2016-01-01

Stress fractures of the first rib on the dominant throwing side are well-described in baseball pitchers; however, lower thoracic rib fractures are not commonly recognized. While common in other sports such as rowing, there is scant literature on these injuries in baseball. Intercostal muscle strains are commonly diagnosed in baseball pitchers and have a nearly identical presentation but also a highly variable healing time. The diagnosis of a rib stress fracture can predict a more protracted recovery. This case series presents two collegiate baseball pitchers on one team during the same season who were originally diagnosed with intercostal muscle strains, which following magnetic resonance imaging (MRI) were found to have actually sustained lower thoracic rib stress fractures. The first sustained a stress fracture of the posterior aspect of the right 8th rib on the dominant arm side, while the second presented with a left-sided 10th rib stress fracture on the nondominant arm side. In both cases, MRI was used to visualize the fractures as plain radiographs are insensitive and commonly negative early in patient presentation. Patients were treated with activity modification, and symptomatic management for 4-6 weeks with a graduated return to throwing and competition by 8-10 weeks. The repetitive high stresses incurred by pitching may cause either dominant or nondominant rib stress fractures and this should be included in the differential diagnosis of thoracic injuries in throwers. It is especially important that athletic trainers and team physicians consider this diagnosis, as rib fractures may have a protracted course and delayed return to play. Additionally, using the appropriate imaging techniques to establish an accurate diagnosis can help inform return-to-play decisions, which have important practical applications in baseball, such as roster management and eligibility.

The crystal structure of the bifunctional deaminase/reductase RibD of the riboflavin biosynthetic pathway in Escherichia coli: implications for the reductive mechanism.

PubMed

Stenmark, Pål; Moche, Martin; Gurmu, Daniel; Nordlund, Pär

2007-10-12

We have determined the crystal structure of the bi-functional deaminase/reductase enzyme from Escherichia coli (EcRibD) that catalyzes two consecutive reactions during riboflavin biosynthesis. The polypeptide chain of EcRibD is folded into two domains where the 3D structure of the N-terminal domain (1-145) is similar to cytosine deaminase and the C-terminal domain (146-367) is similar to dihydrofolate reductase. We showed that EcRibD is dimeric and compared our structure to tetrameric RibG, an ortholog from Bacillus subtilis (BsRibG). We have also determined the structure of EcRibD in two binary complexes with the oxidized cofactor (NADP(+)) and with the substrate analogue ribose-5-phosphate (RP5) and superposed these two in order to mimic the ternary complex. Based on this superposition we propose that the invariant Asp200 initiates the reductive reaction by abstracting a proton from the bound substrate and that the pro-R proton from C4 of the cofactor is transferred to C1 of the substrate. A highly flexible loop is found in the reductase active site (159-173) that appears to control cofactor and substrate binding to the reductase active site and was therefore compared to the corresponding Met20 loop of E. coli dihydrofolate reductase (EcDHFR). Lys152, identified by comparing substrate analogue (RP5) coordination in the reductase active site of EcRibD with the homologous reductase from Methanocaldococcus jannaschii (MjaRED), is invariant among bacterial RibD enzymes and could contribute to the various pathways taken during riboflavin biosynthesis in bacteria and yeast.

Local heat/mass transfer and pressure drop in a two-pass rib-roughened channel for turbine airfoil cooling

NASA Technical Reports Server (NTRS)

Han, J. C.; Chandra, P. R.

1987-01-01

The heat transfer characteristics of turbulent air flow in a multipass channel were studied via the naphthalene sublimation technique. The naphthalene-coated test section, consisting of two straight, square channels joined by a 180 deg turn, resembled the internal cooling passages of gas turbine airfoils. The top and bottom surfaces of the test channel were roughened by rib turbulators. The rib height-to-hydraulic diameter ratio (e/D) were 0.063 and 0.094, and the rib pitch-to-height ratio (P/e) were 10 and 20. The local heat/mass transfer coefficients on the roughened top wall and on the smooth divider and side walls of the test channel were determined for three Reynolds numbers of 15, 30, and 60, thousand, and for three angles of attack (alpha) of 90, 60, and 45 deg. Results showed that the local Sherwood numbers on the ribbed walls were 1.5 to 6.5 times those for a fully developed flow in a smooth square duct. The average ribbed-wall Sherwood numbers were 2.5 to 3.5 times higher than the fully developed values, depending on the rib angle of attack and the Reynolds number. The results also indicated that, before the turn, the heat/mass transfer coefficients in the cases of alpha = 60 and 45 deg were higher than those in the case of alpha=90 deg. However, after the turn, the heat/mass transfer coefficients in the oblique-rib cases were lower than those in the transverse rib case. Correlations for the average Sherwood number ratios for individual channel surfaces and for the overall Sherwood number ratios are reported. Correlations for the fully developed friction factors and for the loss coefficients are also provided.

Measurements of the pulmonary vasculature on thoracic radiographs in healthy dogs compared to dogs with mitral regurgitation.

PubMed

Oui, Heejin; Oh, Juyeon; Keh, Seoyeon; Lee, Gahyun; Jeon, Sunghoon; Kim, Hyunwook; Yoon, Junghee; Choi, Jihye

2015-01-01

This study reassessed the previously reported radiographic method of comparing pulmonary vessels versus rib diameter for differentiating healthy dogs and dogs with mitral regurgitation. The width of the right cranial pulmonary artery and vein at the fourth rib level, right caudal pulmonary artery and vein at the ninth rib level, and the diameters of the fourth rib and ninth rib were measured in prospectively recruited healthy dogs (n = 40) and retrospectively recruited dogs with mitral regurgitation (n = 58). In healthy dogs, the pulmonary arteries and accompanying veins were similar in size. The cranial lobar vessels were smaller than the fourth rib. However, 67.5% of right caudal pulmonary artery diameters and 65% of vein diameters were larger than the ninth rib in healthy dogs. The right caudal pulmonary vein diameter in dogs with mitral regurgitation, particularly those within moderate and severe grades, was significantly larger than that in healthy dogs (P < 0.001). The comparative method used to detect enlargement of the right caudal pulmonary vein relative to the accompanying pulmonary artery had the highest sensitivity (80.2%) and specificity (82.5%) for predicting mitral regurgitation. A cut-off of 1.22 when applying the ninth rib criterion had better specificity (73%) than the most used value ≤ 1 (89.7% sensitivity and 63.8% specificity), although it has less sensitivity (73%). We recommend using the accompanying pulmonary artery and 1.22 × the diameter of the ninth rib as a radiographic criterion for assessing the size of the right caudal pulmonary vein and differentiating healthy dogs from those with mitral regurgitation. © 2014 American College of Veterinary Radiology.

Frequency of intrathoracic injuries in children younger than 3 years with rib fractures.

PubMed

Darling, Stephen E; Done, Stephen L; Friedman, Seth D; Feldman, Kenneth W

2014-10-01

Research documents that among children admitted to trauma intensive care units the number of rib fractures sustained indicates the child's likelihood of having and severity of intrathoracic injury. This has been misused in court to argue that children with multiple rib fractures who lack intrathoracic injury have abnormal bone fragility rather than inflicted injury. To determine frequency of intrathoracic injuries in children younger than 3 years with rib fractures in cases of child abuse and accidental trauma. We conducted a retrospective review of rib fractures caused by documented abuse or accidents from 2003 to 2010 in children treated at Seattle Children's Hospital and Harborview Medical Center. A senior pediatric radiologist and radiology fellow independently reviewed the imaging. Children with bone demineralization were excluded. Descriptive and simple comparative statistics were used. Seventy-two percent (47/65) of infants and toddlers with rib fractures were abused. Abused children had more rib fractures than accidentally injured children (5.55 vs. 3.11, P = 0.012). However intrathoracic injuries as a whole (55.6% vs. 12.8%, P < 0.001) and individual types of intrathoracic injuries were more common with accidents. Rates of other thoracic cage injuries did not differ substantially (27.8% accidents vs. 12.8% abuse, P = 0.064). Intracranial and intra-abdominal injuries and skull fractures were equally frequent, but other extrathoracic fractures were more common with abuse (70.2% vs. 16.7%, P < 0.001). Abused infants and toddlers have fewer intrathoracic injuries but more rib fractures than accidentally injured peers. This likely reflects different injury mechanics. Lack of intrathoracic injuries in abused children with rib fractures does not imply bone fragility.

Number of Ribs Resected is Associated with Respiratory Complications Following Lobectomy with en bloc Chest Wall Resection.

PubMed

Geissen, Nicole M; Medairos, Robert; Davila, Edgar; Basu, Sanjib; Warren, William H; Chmielewski, Gary W; Liptay, Michael J; Arndt, Andrew T; Seder, Christopher W

2016-08-01

Pulmonary lobectomy with en bloc chest wall resection is a common strategy for treating lung cancers invading the chest wall. We hypothesized a direct relationship exists between number of ribs resected and postoperative respiratory complications. An institutional database was queried for patients with non-small cell lung cancer that underwent lobectomy with en bloc chest wall resection between 2003 and 2014. Propensity matching was used to identify a cohort of patients who underwent lobectomy via thoracotomy without chest wall resection. Patients were propensity matched on age, gender, smoking history, FEV1, and DLCO. The relationship between number of ribs resected and postoperative respiratory complications (bronchoscopy, re-intubation, pneumonia, or tracheostomy) was examined. Sixty-eight patients (34 chest wall resections; 34 without chest wall resection) were divided into 3 cohorts: cohort A = 0 ribs resected (n = 34), cohort B = 1-3 ribs resected (n = 24), and cohort C = 4-6 ribs resected (n = 10). Patient demographics were similar between cohorts. The 90-day mortality rate was 2.9 % (2/68) and did not vary between cohorts. On multivariate analysis, having 1-3 ribs resected (OR 19.29, 95 % CI (1.33, 280.72); p = 0.03), 4-6 ribs resected [OR 26.66, (1.48, 481.86); p = 0.03), and a lower DLCO (OR 0.91, (0.84, 0.99); p = 0.02) were associated with postoperative respiratory complications. In patients undergoing lobectomy with en bloc chest wall resection for non-small cell lung cancer, the number of ribs resected is directly associated with incidence of postoperative respiratory complications.

An analytical study of the free and forced vibration response of a ribbed plate with free boundary conditions

NASA Astrophysics Data System (ADS)

Lin, Tian Ran; Zhang, Kai

2018-05-01

An analytical study to predict the vibration response of a ribbed plate with free boundary conditions is presented. The analytical solution was derived using a double cosine integral transform technique and then utilized to study the free and forced vibration of the ribbed plate, as well as the effect of the rib on the modal response of the uniform plate. It is shown that in addition to the three zero-frequency rigid body modes of the plate, the vibration modes of the uniform plate can be classified into four mode groups according to the symmetric properties of the plate with respect to the two orthogonal middle lines parallel to the plate edges. The four mode groups correspond to a double symmetric group, a double anti-symmetric group and two symmetric/anti-symmetric groups. Whilst the inclusion of the rib to the plate is shown to cause distortion to the distribution of vibration modes, most modes can still be traced back to the original modes of the uniform plate. Both the mass and stiffness of the rib are shown to affect the modal vibration of the uniform plate, whereby a dominant effect from the rib mass leads to a decrease in the modal frequency of the plate, whereas a dominant effect from the rib stiffness leads to an increase in plate modal frequency. When the stiffened rib behaves as an effective boundary to the plate vibration, an original plate mode becomes a pair of degenerate modes, whereby one mode has a higher frequency and the other mode has a lower frequency than that of the original mode.

Phrenic Arterial Injury Presenting as Delayed Hemothorax Complicating Simple Rib Fracture.

PubMed

Ahn, Hong Joon; Lee, Jun Wan; Kim, Kun Dong; You, In Sool

2016-04-01

Delayed hemothorax after blunt torso injury is rare, but might be associated with significant morbidity and mortality. We present a case of delayed hemothorax bleeding from phrenic artery injury in a 24-year-old woman. The patient suffered from multiple rib fractures on the right side, a right hemopneumothorax, thoracic vertebral injury and a pelvic bone fracture after a fall from a fourth floor window. Delayed hemothorax associated with phrenic artery bleeding, caused by a stab injury from a fractured rib segment, was treated successfully by a minimally invasive thoracoscopic surgery. Here, we have shown that fracture of a lower rib or ribs might be accompanied by delayed massive hemothorax that can be rapidly identified and promptly managed by thoracoscopic means.

Phrenic Arterial Injury Presenting as Delayed Hemothorax Complicating Simple Rib Fracture

PubMed Central

2016-01-01

Delayed hemothorax after blunt torso injury is rare, but might be associated with significant morbidity and mortality. We present a case of delayed hemothorax bleeding from phrenic artery injury in a 24-year-old woman. The patient suffered from multiple rib fractures on the right side, a right hemopneumothorax, thoracic vertebral injury and a pelvic bone fracture after a fall from a fourth floor window. Delayed hemothorax associated with phrenic artery bleeding, caused by a stab injury from a fractured rib segment, was treated successfully by a minimally invasive thoracoscopic surgery. Here, we have shown that fracture of a lower rib or ribs might be accompanied by delayed massive hemothorax that can be rapidly identified and promptly managed by thoracoscopic means. PMID:27051252

FOCUS SPLITTING ASSOCIATED WITH PROPAGATION OF FOCUSED ULTRASOUND THROUGH THE RIB CAGE

PubMed Central

Khokhlova, V. A.; Bobkova, S. M.; Gavrilov, L. R.

2011-01-01

The effect of focus splitting after propagation of focused ultrasound through a rib cage is investigated theoretically. It is shown that the mechanism of this effect is caused by the interference of waves from two or more spatially separated sources, such as intercostal spaces. Analytical estimates of the parameters of splitting are obtained, i.e., the number of foci, their amplitudes, diameter, and the distance between them, depending on the transducer parameters, as well as the dimensions of the rib cage and position of ribs relative to the radiator. Various configurations of the relative positioning of ribs and radiator are considered; it is shown which of them are the most effective for real surgical operations. PMID:21607120

A V-band wafer probe using ridge-trough waveguide

NASA Astrophysics Data System (ADS)

Godshalk, Edward M.

1991-12-01

A V-band (50-75 GHz) wafer probe is presented. The probe features a type of waveguide developed to allow transition from rectangular waveguide to coplanar waveguide. The waveguide consists of a ridge extending from the upper waveguide wall into a trough in the lower waveguide wall, and is known as the ridge-trough waveguide. A mathematical model is presented that allows important properties of the ridge-trough waveguide, such as the cutoff frequency and characteristic impedance, to be calculated.

Folding retractable protective dome for space vehicle equipment

NASA Technical Reports Server (NTRS)

Clark, Paul R. (Inventor); Messinger, Ross H. (Inventor)

2008-01-01

A folding, retractable dome for protecting a feature, such as a docking mechanism, a hatch or other equipment at an exterior surface of a space vehicle, includes a plurality of arcuate ribs, each having opposite ends respectively pinioned at opposite sides of the feature at the surface of the vehicle for rotational movement about an axis of rotation extending through the opposite ends and through an arcuate path of revolution extending over the feature, and a flexible cover attached to each of the ribs such that, in a deployed configuration of the dome, in which adjacent ribs are rotated apart from each other at a maximum relative angle therebetween, the cover is stretched generally tangentially between the adjacent ribs to form a generally arcuate shield over the feature, and in a retracted position of the dome, in which adjacent ribs are rotated together at a minimum relative angle therebetween, the cover is collapsed to define folded pleats between the adjacent ribs.

Differentiating the Causes of Spontaneous Rib Fracture After Breast Cancer.

PubMed

Harris, Susan R

2016-12-01

Spontaneous rib fracture after treatment for primary breast cancer is not uncommon. Although metastatic disease accounts for about 30% of spontaneous rib fractures and should constitute the first line of diagnostic investigation, other possible contributors include primary osteoporosis or secondary osteoporosis resulting from cancer treatments. Chemotherapy-induced menopause, aromatase inhibitors, radiation therapy, and long-term bisphosphonate use can all contribute to bone fragility, including spontaneous rib fractures in the latter 3. Drawing on recent breast cancer practice guidelines as well as population-based studies of fracture risk for women with a history of breast cancer and systematic reviews, this Perspective will provide an update on recent developments in understanding how to differentiate the possible reasons for non-traumatic rib fracture in women treated for breast cancer. In addition to describing the various possible causes of spontaneous rib fracture, the recommended medical and imaging procedures for differentiating among the potential causes will be presented. Copyright © 2016 Elsevier Inc. All rights reserved.

Determinants of rib motion in flail chest.

PubMed

Cappello, M; Legrand, A; De Troyer, A

1999-03-01

We have previously developed a canine model of isolated flail chest to assess the effects of this condition on the mechanics of breathing, and these studies have led to the conclusion that the respiratory displacement of the fractured ribs is primarily determined by the fall in pleural pressure (Delta Ppl) and the action of the parasternal intercostal muscles. The present studies were designed to test the validity of this conclusion. A flail was induced in six supine anesthetized animals by fracturing both dorsally and ventrally the second to fifth ribs on the right side of the chest, after which the phrenic nerve roots were bilaterally sectioned in the neck. Sectioning the phrenic nerves caused a 34% decrease in Delta Ppl, associated with a 39% increase in parasternal intercostal inspiratory EMG activity (p < 0.05), and resulted in a marked reduction in the inspiratory inward displacement of the ribs. In three animals, the inward rib displacement was even reversed into a small outward displacement. When the airway was then occluded at end-expiration to increase Delta Ppl during the subsequent inspiration, all animals again showed a clear-cut inward rib displacement. These observations therefore confirm that in dogs with flail chest, the inspiratory displacement of the fractured ribs is set by the balance between the force related to pleural pressure and that generated by the parasternal intercostals. These observations also point to the critical importance of the pattern of inspiratory muscle activation in determining the magnitude of rib cage paradox in such patients.

Periods of vertebral column sensitivity to boric acid treatment in CD-1 mice in utero.

PubMed

Cherrington, Jana W; Chernoff, Neil

2002-01-01

Boric acid (BA) has many uses as an industrial compound and is widely distributed in the environment. BA has been shown to produce rib agenesis, a rare effect in laboratory animals. This study was conducted to determine if there is a period of sensitivity to this unusual effect. BA (500 or 750 mg/kg) was administered p.o. to pregnant CD-1 mice once daily on gestational days (GDs) 6-10. A reduction of 13th rib length occurred at both dose levels. BA 400mg/kg was also administered twice daily on GD 6, 7, 8, 9, or 10 or on GDs 6-8. A significant decrease in average fetal weight was observed in all treatment groups. Significant increases in the incidence of cervical ribs/ossifications resulted from treatments on GD 7 and GDs 6-8. Rib agenesis occurred with treatment on GD 8 and GDs 6-8. Reduced rib length, a decreased incidence of supernumerary ribs (SNR), and an increased incidence of fused and/or branched ribs occurred when dams were treated GDs 6-8. Doses of 750 mg/kg given twice on day 8 produced significant increases in several thoracic skeletal anomalies. Further studies of pathogenesis are necessary to determine the earliest perturbations and the processes that are affected. The sensitivity of embryos to treatment on GD 8 to rib agenesis suggests that BA is affecting early processes such as gastrulation and presomitic mesoderm formation and patterning in this area.

ACR Appropriateness Criteria® rib fractures.

PubMed

Henry, Travis S; Kirsch, Jacobo; Kanne, Jeffrey P; Chung, Jonathan H; Donnelly, Edwin F; Ginsburg, Mark E; Heitkamp, Darel E; Kazerooni, Ella A; Ketai, Loren H; McComb, Barbara L; Parker, J Anthony; Ravenel, James G; Restrepo, Carlos Santiago; Saleh, Anthony G; Shah, Rakesh D; Steiner, Robert M; Suh, Robert D; Mohammed, Tan-Lucien H

2014-11-01

Rib fracture is the most common thoracic injury, present in 10% of all traumatic injuries and almost 40% of patients who sustain severe nonpenetrating trauma. Although rib fractures can produce significant morbidity, the diagnosis of associated complications (such as pneumothorax, hemothorax, pulmonary contusion, atelectasis, flail chest, cardiovascular injury, and injuries to solid and hollow abdominal organs) may have a more significant clinical impact. When isolated, rib fractures have a relatively low morbidity and mortality, and failure to detect isolated rib fractures does not necessarily alter patient management or outcome in uncomplicated cases. A standard posteroanterior chest radiograph should be the initial, and often the only, imaging test required in patients with suspected rib fracture after minor trauma. Detailed radiographs of the ribs rarely add additional information that would change treatment, and, although other imaging tests (eg, computed tomography, bone scan) have increased sensitivity for detection of rib fractures, there are little data to support their use. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review process 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.

Potential Benefits of Rib Fracture Fixation in Patients with Flail Chest and Multiple Non-flail Rib Fractures.

PubMed

Qiu, Meiguang; Shi, Zhanjun; Xiao, Jun; Zhang, Xuming; Ling, Shishui; Ling, Hao

2016-12-01

The purpose of this study is to evaluate the potential benefits of rib fracture fixation in patients with flail chest and multiple non-flail rib fractures versus conventional treatment modalities. A retrospective reviewed study compared 86 cases which received surgical treatment between June 2009 and May 2013 to 76 cases which received conservative treatment between January 2006 and May 2009. The patients were divided into the flail chest ( n  = 38) and multiple non-flail rib fracture groups ( n  = 124). In the flail chest group, the mechanical ventilation time, ICU monitoring time, tracheostomies, thoracic deformity, and impaired pulmonary function and return to full-time employment were compared. In the multiple non-flail rib fracture group, fracture healing, visual analog scale (VAS) pain score, inpatient length of stay, atelectatic, pulmonary complications, and normal activity-returning time were compared. Patients in the flail chest operative fixation group had significantly shorter ICU stay, decreased ventilator requirements, fewer tracheostomies, less thoracic deformity and impaired pulmonary function, and more returned to full-time employment. Patients in the multiple non-flail rib fracture operative fixation had shorter hospital stay, less pain, earlier return to normal activity, more fracture healing, less atelectasis, and fewer pulmonary infections. This study demonstrates the potential benefits of surgical stabilization of flail chest and multiple non-flail rib fractures with plate fixation. When compared with conventional conservative management, operatively managed patients demonstrated improved clinical outcomes.

Evaluation of Rib Fractures on a Single-in-plane Image Reformation of the Rib Cage in CT Examinations.

PubMed

Dankerl, Peter; Seuss, Hannes; Ellmann, Stephan; Cavallaro, Alexander; Uder, Michael; Hammon, Matthias

2017-02-01

This study aimed to evaluate the diagnostic performance of using a reformatted single-in-plane image reformation of the rib cage for the detection of rib fractures in computed tomography (CT) examinations, employing different levels of radiological experience. We retrospectively evaluated 10 consecutive patients with and 10 patients without rib fractures, whose CT scans were reformatted to a single-in-plane image reformation of the rib cage. Eight readers (two radiologists, two residents in radiology, and four interns) independently evaluated the images for the presence of rib fractures using a reformatted single-in-plane image and a multi-planar image reformation. The time limit was 30 seconds for each read. A consensus of two radiologist readings was considered as the reference standard. Diagnostic performance (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) was assessed and evaluated per rib and per location (anterior, lateral, posterior). To determine the time limit, we prospectively analyzed the average time it took radiologists to assess the rib cage, in a bone window setting, in 50 routine CT examinations. McNemar test was used to compare the diagnostic performances. Single image reformation was successful in all 20 patients. The sensitivity, specificity, PPV, and NPV for the detection of rib fractures using the conventional multi-planar read were 77.5%, 99.2%, 89.9%, and 98.0% for radiologists; 46.3%, 99.7%, 92.5%, and 95.3% for residents; and 29.4%, 99.4%, 82.5%, and 93.9% for interns, respectively. Sensitivity, PPV, and NPV increased across all three groups of experience, using the reformatted single-in-plane image of the rib cage (radiologists: 85.0%, 98.6%, and 98.7%; residents: 80.0%, 92.8%, and 98.2%; interns: 66.9%, 89.9%, and 97.1%), whereas specificity did not change significantly (99.9%, 99.4%, and 99.3%). The diagnostic performance of the interns and residents was significantly better when evaluating the single-in-plane image reformations (P < .01). The diagnostic performance of the radiologists was better when evaluating the single-in-plane image reformations; however, there was no significant difference (statistical power: 0.32). The diagnostic performance for the detection of rib fractures, using CT images that have been reformatted to a single-in-plane image, improves for readers from different educational levels when the evaluation time is restricted to 30 seconds or less. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Yb-doped mixed-sesquioxide films grown by pulsed laser deposition

NASA Astrophysics Data System (ADS)

Prentice, Jake J.; Grant-Jacob, James A.; Shepherd, David P.; Eason, Robert W.; Mackenzie, Jacob I.

2018-06-01

Growth and characterization of compositionally tuned, ytterbium-doped mixed lutetium-scandium oxide, and pure lutetia and scandia crystalline films are presented. Pulsed laser deposition was employed to grow these sesquioxide films, of thicknesses up to 20 μm, on (0 0 0 1)-sapphire substrates. By varying the atomic ratio of lutetium to scandium in the target, the lattice parameter of the resulting films could be tuned to match that of the single-crystal c-cut sapphire substrate and thereby achieve a lattice mismatch of <0.1%. Optimization of growth parameters led to a reduction of undesirable particulates and scattering points within the film. X-ray diffraction measurements show (2 2 2)-orientated epitaxial growth with crystallinity comparable to bulk crystals. Through pole figure and electron-backscatter imaging measurements, it was found that two inverted cubic lattice orientations grow with micron-scaled domains. Growth of these lattice-matched mixed sesquioxides paves the way for fabrication of high-quality waveguides suitable for generation of ultrashort laser pulses.

Controlled replication of butterfly wings for achieving tunable photonic properties.

PubMed

Huang, Jingyun; Wang, Xudong; Wang, Zhong Lin

2006-10-01

The fine structure of the wing scale of a Morpho Peleides butterfly was examined carefully, and the entire configuration was completely replicated by a uniform Al(2)O(3) coating through a low-temperature ALD process. An inverted structure was achieved by removing the butterfly wing template at high temperature, forming a polycrystalline Al(2)O(3) shell structure with precisely controlled thickness. Other than the copy of the morphology of the structure, the optical property, such as the existence of PBG, was also inherited by the alumina replica. Reflection peaks at the violet/blue range were detected on both original wings and their replica, while a simple alumina coating shifted the reflection peak to longer wavelength because of the change of periodicity and refraction index. The alumina replicas also exhibited similar functional structures as waveguide and beam splitter, which may be used as the building blocks for photonic ICs with high reproducibility and lower fabrication cost compared to traditional lithography techniques.

Logical spin-filtering in a triangular network of quantum nanorings with a Rashba spin-orbit interaction

NASA Astrophysics Data System (ADS)

Dehghan, E.; Sanavi Khoshnoud, D.; Naeimi, A. S.

2018-01-01

The spin-resolved electron transport through a triangular network of quantum nanorings is studied in the presence of Rashba spin-orbit interaction (RSOI) and a magnetic flux using quantum waveguide theory. This study illustrates that, by tuning Rashba constant, magnetic flux and incoming electron energy, the triangular network of quantum rings can act as a perfect logical spin-filtering with high efficiency. By changing in the energy of incoming electron, at a proper value of the Rashba constant and magnetic flux, a reverse in the direction of spin can take place in the triangular network of quantum nanorings. Furthermore, the triangular network of quantum nanorings can be designed as a device and shows several simultaneous spintronic properties such as spin-splitter and spin-inverter. This spin-splitting is dependent on the energy of the incoming electron. Additionally, different polarizations can be achieved in the two outgoing leads from an originally incoming spin state that simulates a Stern-Gerlach apparatus.

20 CFR 225.22 - Employee RIB PIA used in survivor annuities.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... This PIA is computed in accordance with section 215 of the Social Security Act using the deceased... RETIREMENT ACT PRIMARY INSURANCE AMOUNT DETERMINATIONS PIA's Used in Computing Survivor Annuities and the... Employee Retirement Insurance Benefit PIA (Employee RIB PIA) is used to compute the employee RIB amount...

FUEL ELEMENT SUPPORT

DOEpatents

Wyman, W.L.

1961-06-27

The described cylindrical fuel element has longitudinally spaced sets of short longitudinal ribs circumferentially spaced from one another. The ribs support the fuel element in a coolant tube so that there is an annular space for coolant flow between the fuel element and the interior of the coolant tube. If the fuel element grows as a result of reactor operation, the circumferential distribution of the ribs maintains the uniformity of the annular space between the coolant tube and the fuel element, and the collapsibility of the ribs prevents the fuel element from becoming jammed in the coolant tube.

Analysis and test of a 16-foot radial rib reflector developmental model

NASA Technical Reports Server (NTRS)

Birchenough, Shawn A.

1989-01-01

Analytical and experimental modal tests were performed to determine the vibrational characteristics of a 16-foot diameter radial rib reflector model. Single rib analyses and experimental tests provided preliminary information relating to the reflector. A finite element model predicted mode shapes and frequencies of the reflector. The analyses correlated well with the experimental tests, verifying the modeling method used. The results indicate that five related, characteristic mode shapes form a group. The frequencies of the modes are determined by the relative phase of the radial ribs.

Thoracic Outlet Syndrome in a Volleyball Player Due to Nonunion of the First Rib Fracture.

PubMed

Puttmann, Kathleen T; Satiani, Bhagwan; Vaccaro, Patrick

2016-11-01

Fracture of the first rib with ensuing callus formation is a rare cause of thoracic outlet syndrome. We report a case of a 17-year-old female volleyball player who presented with months of chronic arm pain. Radiographic imaging demonstrated nonunion fracture of the first rib. Physical therapy had been unsuccessful in relieving the pain, and surgical management was performed with resection of the first rib through a transaxillary approach with complete resolution of symptoms. Inflammation surrounding such fractures may destroy tissue planes, making dissection more technically difficult.

Comprehensive approach to the management of the patient with multiple rib fractures: a review and introduction of a bundled rib fracture management protocol.

PubMed

Witt, Cordelie E; Bulger, Eileen M

2017-01-01

Rib fractures are common among patients sustaining blunt trauma, and are markers of severe bodily and solid organ injury. They are associated with high morbidity and mortality, including multiple pulmonary complications, and can lead to chronic pain and disability. Clinical and radiographic scoring systems have been developed at several institutions to predict risk of complications. Clinical strategies to reduce morbidity have been studied, including multimodal pain management, catheter-based analgesia, pulmonary hygiene, and operative stabilization. In this article, we review risk factors for morbidity and complications, intervention strategies, and discuss experience with bundled clinical pathways for rib fractures. In addition, we introduce the multidisciplinary rib fracture management protocol used at our level I trauma center.

Assessment and management of rib fracture pain in geriatric population: an ode to old age.

PubMed

Wardhan, Richa

2013-10-01

Pain management for traumatic rib fractures has been described in literature, but there is paucity of data when it comes to acute pain management in the elderly, let alone pain resulting from traumatic rib fractures. This article focuses on challenges of assessment of pain in elderly patients and the various options available for pain management including utilization of nerve blocks. Nerve blocks are instrumental in treating rib fracture pain along with utilization of opioids and nonopioids thus formulating a multimodal approach to pain management. The goal is to devise a proper pain management regimen for geriatric patients with rib fractures to decrease the morbidity and mortality associated with it. Developing institutional protocols is one step forward towards quality care for such patients.

The respective effect of under-rib convection and pressure drop of flow fields on the performance of PEM fuel cells

PubMed Central

Wang, Chao; Zhang, Qinglei; Shen, Shuiyun; Yan, Xiaohui; Zhu, Fengjuan; Cheng, Xiaojing; Zhang, Junliang

2017-01-01

The flow field configuration plays an important role on the performance of proton exchange membrane fuel cells (PEMFCs). For instance, channel/rib width and total channel cross-sectional area determine the under-rib convection and pressure drop respectively, both of which directly influence the water removal, in turn affecting the oxygen supply and cathodic oxygen reduction reaction. In this study, effects of under-rib convection and pressure drop on cell performance are investigated experimentally and numerically by adjusting the channel/rib width and channel cross-sectional area of flow fields. The results show that the performance differences with various flow field configurations mainly derive from the oxygen transport resistance which is determined by the water accumulation degree, and the cell performance would benefit from the narrower channels and smaller cross sections. It reveals that at low current densities when water starts to accumulate in GDL at under-rib regions, the under-rib convection plays a more important role in water removal than pressure drop does; in contrast, at high current densities when water starts to accumulate in channels, the pressure drop dominates the water removal to facilitate the oxygen transport to the catalyst layer. PMID:28251983

Rib Diced Cartilage-Fascia Grafting in Dorsal Nasal Reconstruction: A Randomized Clinical Trial of Wrapping With Rectus Muscle Fascia vs Deep Temporal Fascia.

PubMed

As'adi, Kamran; Salehi, Seyed Hamid; Shoar, Saeed

2014-08-01

Rib cartilage is an abundant source for cartilage grafts when significant dorsal nasal augmentation or structural support is indicated. Diced cartilage wrapped in fascia was developed to counteract warping, visibility, and displacement of rib cartilage as a dorsal solid graft. The technique for wrapping diced cartilage has evolved during the past several years. The authors compared 2 distinct fascial sleeves for wrapping rib diced cartilage in the treatment of patients who required major dorsal nasal augmentation. Thirty-six patients who planned to undergo major dorsal nasal reconstruction with diced costal rib cartilage were assigned randomly to 1 of 2 groups: the intervention group, which received grafts wrapped with rectus muscle fascia from the rib cartilage harvesting site, or the control group, which received deep temporal fascia harvested separately. Outcomes were compared between the groups. Patients in the intervention group had significantly shorter operating times, significantly higher average satisfaction scores, and significantly shorter postoperative hospital stays than did patients in the control group. Harvesting rectus muscle fascia for wrapping diced rib cartilage is a feasible and reliable technique in dorsal nasal reconstruction surgery. It is associated with favorable outcomes and a high level of patient satisfaction. 4. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

Design and testing of integrated Bragg grating sensor systems for advanced grid structure

NASA Astrophysics Data System (ADS)

Amano, Masataro; Mizutani, Tadahito; Okabe, Yoji; Takeda, Nobuo; Ozaki, Tsuyoshi

2006-03-01

In this research, the authors target on the construction of structural health monitoring system of Advanced Grid Structure (AGS) made of Carbon fiber reinforced plastic (CFRP). AGS has often been applied to aerospace structures because of the following advantages: (1) Since ribs carry only axial forces, the weakness in the transverse direction of the CFRP unidirectional laminates is negligible. (2) AGS has damage tolerance because the fracture of a rib hardly affects other ribs, namely AGS is a fail-safe structure. In this research, in order to detect existence and regions of rib fractures in AGS, we embedded multiplexed fiber Bragg grating (FBG) sensors into AGS in rib longitudinal directions for measurement of strains. Monitoring of the change in rib longitudinal strains is the most effective SHM system for AGS. In order to confirm our proposal, we carried out following discussions. First, we analytically revealed that the change in rib longitudinal strains was the most sensitive signal for damage detection because of AGS's structural redundancy. Then, we introduced a statistical outlier analysis technique into the SHM system for damage recognition. Finally, we established AGS with the SHM system and verified experimentally. The result of the test showed that damage existence and regions in AGS could be detected with the proposed SHM system.

Spontaneous rib fractures.

PubMed

Katrancioglu, Ozgur; Akkas, Yucel; Arslan, Sulhattin; Sahin, Ekber

2015-07-01

Other than trauma, rib fracture can occur spontaneously due to a severe cough or sneeze. In this study, patients with spontaneous rib fractures were analyzed according to age, sex, underlying pathology, treatment, and complications. Twelve patients who presented between February 2009 and February 2011 with spontaneous rib fracture were reviewed retrospectively. The patients' data were evaluated according to anamnesis, physical examination, and chest radiographs. The ages of the patients ranged from 34 to 77 years (mean 55.91 ± 12.20 years), and 7 (58.4%) were male. All patients had severe cough and chest pain. The fractures were most frequently between 4th and 9th ribs; multiple rib fractures were detected in 5 (41.7%) patients. Eight (66.7%) patients had chronic obstructive pulmonary disease, 2 (16.7%) had bronchial asthma, and 2 (16.7%) had osteoporosis. Bone densitometry revealed a high risk of bone fracture in all patients. Patients with chronic obstructive pulmonary disease or bronchial asthma had been treated with high-dose steroids for over a year. Spontaneous rib fracture due to severe cough may occur in patients with osteoporosis, chronic obstructive pulmonary disease, or bronchial asthma, receiving long-term steroid therapy. If these patients have severe chest pain, chest radiography should be performed to check for bone lesions. © The Author(s) 2015.

Enhanced heat transfer with full circumferential ribs in helical pipe

NASA Astrophysics Data System (ADS)

Chang, S. W.; Su, L. M.; Yang, T. L.

2002-08-01

This paper describes an experimental study of heat transfers in the smooth-walled and rib-roughened helical pipes with reference to the design of enhanced cooling passages in the cylinder head and liner of a marine propulsive diesel engine. The manner in which the repeated ribs modify the forced heat convection in the helical pipe is considered for the case where the flow is turbulent upon entering the coil but laminar in further downstream. A selection of experimental results illustrates the individual and interactive effects of Dean vortices and rib-flows on heat transfer along the inner and outer helixes of coils. The experimental-based observations reveal that the centrifugal force modifies the heat transfer in a manner to generate circumferential heat transfer variation with better cooling performance on the outer edge relative to its inner counterpart even with the agitated flow field caused by the repeated ribs. Heat transfer augmentation factor in the range of 1.3 - 3 times of the smooth-walled level is achieved using the present ribbing geometry. A set of empirical correlations based on the experimental data has been developed to permit the evaluation of heat transfers along the inner and outer helixes of the smooth-walled and rib-roughened helical pipes.

A Study on the Performance of the Split Reaction Water Turbine with Guide Ribs

NASA Astrophysics Data System (ADS)

Allen, Deuel H.; Villanueva, Eliseo P.

2015-09-01

The development of technologies that make use of renewable energy is of great significance presently. A new kind of turbine called Split Reaction Water Turbine (SRWT) using PVC pipes as material is a major contribution towards harnessing the energy potentials of small stream low head water resources. SRWTs of diameter to height ratio (D/H = 110 cm/160 cm) were tested at the MSU-IIT College of Engineering Fluid Engineering Laboratory. Data on volumetric flow and pressure head at the turbine inlet of the SRWT were recorded using National Instrument Data Processing System using LabView software. In later experiments, guide ribs were installed at the vane of the exit nozzles in order to determine the difference in the performance of the ribbed and the non-ribbed SRWT. Simulations of the running SRWT were conducted using SOLIDWORKS software. Results of the simulations aided in the thorough analyses of the data from the experimental runs. A comparison of data from the ribbed and non-ribbed SRWT shows that guide ribs were effective in directing the momentum of the exiting water to improve the speed of rotation. In this study, the increase in the speed of the Split Reaction Water Turbine was as much as 46%.

Rib fractures predict incident limb fractures: results from the European prospective osteoporosis study.

PubMed

Ismail, A A; Silman, A J; Reeve, J; Kaptoge, S; O'Neill, T W

2006-01-01

Population studies suggest that rib fractures are associated with a reduction in bone mass. While much is known about the predictive risk of hip, spine and distal forearm fracture on the risk of future fracture, little is known about the impact of rib fracture. The aim of this study was to determine whether a recalled history of rib fracture was associated with an increased risk of future limb fracture. Men and women aged 50 years and over were recruited from population registers in 31 European centres for participation in a screening survey of osteoporosis (European Prospective Osteoporosis Study). Subjects were invited to complete an interviewer-administered questionnaire that included questions about previous fractures including rib fracture, the age of their first fracture and also the level of trauma. Lateral spine radiographs were performed and the presence of vertebral deformity was determined morphometrically. Following the baseline survey, subjects were followed prospectively by annual postal questionnaire to determine the occurrence of clinical fractures. The subjects included 6,344 men, with a mean age of 64.2 years, and 6,788 women, with a mean age of 63.6 years, who were followed for a median of 3 years (range 0.4-5.9 years), of whom 135 men (2.3%) and 101 women (1.6%) reported a previous low trauma rib fracture. In total, 138 men and 391 women sustained a limb fracture during follow-up. In women, after age adjustment, those with a recalled history of low trauma rib fracture had an increased risk of sustaining 'any' limb fracture [relative hazard (RH)=2.3; 95% CI 1.3, 4.0]. When stratified by fracture type the predictive risk was more marked for hip (RH=7.7; 95% CI 2.3, 25.9) and humerus fracture (RH=4.5; 95% CI 1.4, 14.6) than other sites (RH=1.6; 95% CI 0.6, 4.3). Additional adjustment for prevalent vertebral deformity and previous (non-rib) low trauma fractures at other sites slightly reduced the strength of the association between rib fracture and subsequent limb fracture. In men, after age adjustment, there was a small though non-significant association between recalled history of rib fracture and future limb fracture. Our data highlight the importance of rib fracture as a marker of bone fragility in women.

The clinical implications of severe low rib fracture in the management of diaphragm injury: A Case Control Study.

PubMed

Kim, Seongyup; Choi, Woo Jin; Lee, Kawng Ho; Byun, Chun Sung; Bae, Keum Seok; Park, Il Hwan

2017-06-01

The objective of this study was to analyze the differences in clinical presentation and characteristics with regard to diaphragmatic injury between blunt trauma patients with severe low rib fractures and those without severe low rib fractures. The medical records of all patients with diaphragmatic injuries who were surgically treated at this level I trauma center, between January 2004 and December 2016 were reviewed. Patient notes, radiologic findings, and operative reports were evaluated. All of the diaphragmatic injuries were confirmed based on the operative findings. Rib fracture with displacement between the ends of the fracture of more than half the width of the fractured rib on computed tomography was classified as 'severe rib fracture'. Patients were categorized into 2 groups and analyzed: those who had more than one severe rib fracture in low ribs on the ipsilateral side of the diaphragm injury (Severe group), and those with no severe rib fracture (Non-severe group). Delayed diagnosis of diaphragmatic injury was more frequent in the Severe group than in the Non-severe group (81.8% vs 36.8%, p-value = 0.026). With regard to initial indications for operation, intrathoracic visceral herniation was more frequent in the Non-severe group (78.9% vs 18.2%, p-value = 0.002), while hemothorax was more frequent in the Severe group (63.6% vs 5.3%, p-value = 0.001). Central type diaphragmatic laceration was more frequent in the Non-severe group than in the Severe group (78.9% vs 18.2%, p-value = 0.002). The diameter of diaphragmatic injury was larger in the Non-severe group than in the Severe group (9.70 ± 4.10 cm vs 4.80 ± 3.60 cm, p-value = 0.004). The results of this study imply that a low threshold for thoracotomy or laparotomy should be considered in blunt trauma patients with severe low rib fractures for the purpose of hidden diaphragmatic injury detection and management. Copyright © 2017. Published by Elsevier Ltd.

Optimal Central Obesity Measurement Site for Assessing Cardiometabolic and Type 2 Diabetes Risk in Middle-Aged Adults

PubMed Central

Millar, Seán R.; Perry, Ivan J.; Phillips, Catherine M.

2015-01-01

Objectives Despite recommendations that central obesity assessment should be employed as a marker of cardiometabolic health, no consensus exists regarding measurement protocol. This study examined a range of anthropometric variables and their relationships with cardiometabolic features and type 2 diabetes in order to ascertain whether measurement site influences discriminatory accuracy. In particular, we compared waist circumference (WC) measured at two sites: (1) immediately below the lowest rib (WC rib) and (2) between the lowest rib and iliac crest (WC midway), which has been recommended by the World Health Organisation and International Diabetes Federation. Materials and Methods This was a cross-sectional study involving a random sample of 2,002 men and women aged 46-73 years. Metabolic profiles and WC, hip circumference, pelvic width and body mass index (BMI) were determined. Correlation, logistic regression and area under the receiver operating characteristic curve analyses were used to evaluate obesity measurement relationships with metabolic risk phenotypes and type 2 diabetes. Results WC rib measures displayed the strongest associations with non-optimal lipid and lipoprotein levels, high blood pressure, insulin resistance, impaired fasting glucose, a clustering of metabolic risk features and type 2 diabetes, in both genders. Rib-derived indices improved discrimination of type 2 diabetes by 3-7% compared to BMI and 2-6% compared to WC midway (in men) and 5-7% compared to BMI and 4-6% compared to WC midway (in women). A prediction model including BMI and central obesity displayed a significantly higher area under the curve for WC rib (0.78, P=0.003), Rib/height ratio (0.80, P<0.001), Rib/pelvis ratio (0.79, P<0.001), but not for WC midway (0.75, P=0.127), when compared to one with BMI alone (0.74). Conclusions WC rib is easier to assess and our data suggest that it is a better method for determining obesity-related cardiometabolic risk than WC midway. The clinical utility of rib-derived indices, or alternative WC measurements, deserves further investigation. PMID:26042771

Microminiature optical waveguide structure and method for fabrication

DOEpatents

Strand, O.T.; Deri, R.J.; Pocha, M.D.

1998-12-08

A method for manufacturing low-cost, nearly circular cross section waveguides comprises starting with a substrate material that a molten waveguide material can not wet or coat. A thin layer is deposited of an opposite material that the molten waveguide material will wet and is patterned to describe the desired surface-contact path pedestals for a waveguide. A waveguide material, e.g., polymer or doped silica, is deposited. A resist material is deposited and unwanted excess is removed to form pattern masks. The waveguide material is etched away to form waveguide precursors and the masks are removed. Heat is applied to reflow the waveguide precursors into near-circular cross-section waveguides that sit atop the pedestals. The waveguide material naturally forms nearly circular cross sections due to the surface tension effects. After cooling, the waveguides will maintain the round shape. If the width and length are the same, then spherical ball lenses are formed. Alternatively, the pedestals can be patterned to taper along their lengths on the surface of the substrate. This will cause the waveguides to assume a conical taper after reflowing by heat. 32 figs.

Microminiature optical waveguide structure and method for fabrication

DOEpatents

Strand, Oliver T.; Deri, Robert J.; Pocha, Michael D.

1998-01-01

A method for manufacturing low-cost, nearly circular cross section waveguides comprises starting with a substrate material that a molten waveguide material can not wet or coat. A thin layer is deposited of an opposite material that the molten waveguide material will wet and is patterned to describe the desired surface-contact path pedestals for a waveguide. A waveguide material, e.g., polymer or doped silica, is deposited. A resist material is deposited and unwanted excess is removed to form pattern masks. The waveguide material is etched away to form waveguide precursors and the masks are removed. Heat is applied to reflow the waveguide precursors into near-circular cross-section waveguides that sit atop the pedestals. The waveguide material naturally forms nearly circular cross sections due to the surface tension effects. After cooling, the waveguides will maintain the round shape. If the width and length are the same, then spherical ball lenses are formed. Alternatively, the pedestals can be patterned to taper along their lengths on the surface of the substrate. This will cause the waveguides to assume a conical taper after reflowing by heat.

Method and apparatus for preventing cyclotron breakdown in partially evacuated waveguide

DOEpatents

Moeller, Charles P.

1987-01-01

Cyclotron breakdown is prevented in a partially evacuated waveguide by providing a section of waveguide having an axial cut therein in order to apply a potential across the two halves of the waveguide. This section is positioned in the waveguide crossing the area of electron cyclotron resonance. The potential applied across the waveguide halves is used to deflect seed electrons into the wall of the waveguide in order to prevent ionization of gas molecules and creation of more electron ion pairs which would result in cyclotron breakdown. Support means is also disclosed for electrically isolating the waveguide halves and transition means is provided between the section of the waveguide with the axial cut and the solid waveguide at either end thereof.

[Cohort study on the prevalence and risk factors of late pulmonary complications in adults following a closed minor chest trauma].

PubMed

Plourde, Miville; Émond, Marcel; Lavoie, André; Guimont, Chantal; Le Sage, Natalie; Chauny, Jean-Marc; Bergeron, Éric; Vanier, Laurent; Moore, Lynne; Allain-Boulé, Nadine; Fratu, Ramona-Florina; Dufresne, Maryline

2013-11-01

The objectives of this study are to determine the prevalence, risk factors, and time to onset of delayed hemothorax and pneumothorax in adults who experienced a minor blunt thoracic trauma. A prospective cohort of 450 consecutive patients was recruited. Eligible patients had to be over 16 years of age, consulted within 72 hours for a trauma, and available for outpatient follow-up at 2, 7, and 14 days posttrauma. The clinical outcome investigated was the presence of delayed pneumothorax or hemothorax on the follow-up chest x-ray. Delayed hemothorax occurred in 11.8% (95% CI 8.8-14.8), and delayed pneumothorax occurred in 0.9% (95% CI 0.2-2.3) of participants. During the 14-day follow-up period, 87.0% of these delayed complications developed in the first week. In the multivariate analysis, the only statistically significant risk factor for delayed complications was the location of fractures on the x-ray of the hemithorax. The adjusted odds ratio was 1.52 (95% CI 0.62-3.73) for the lower ribs (tenth to twelfth rib), 3.11 (95% CI 1.60-6.08) for the midline ribs (sixth to ninth rib), and 5.05 (95% CI 1.80-14.19) for the upper ribs (third to fifth rib) versus patients with no fractures. The presence of at least one rib fracture between the third and ninth rib on the x-ray of the hemithorax is a significant risk factor for delayed hemothorax and pneumothorax.

Characterization of Human Rib Biomechanical Responses due to Three-Point Bending.

PubMed

Kalra, Anil; Saif, Tal; Shen, Ming; Jin, Xin; Zhu, Feng; Begeman, Paul; Yang, King H; Millis, Scott

2015-11-01

In the elderly population, rib fracture is one of the most common injuries sustained in motor vehicle crashes. The current study was conducted to predict the biomechanical fracture responses of ribs with respect to age, gender, height, weight and percentage of ash content. Three-point bending experiments were conducted on 278 isolated rib samples extracted from 82 cadaver specimens (53 males and 29 females between the ages of 21 and 87 years) for 6th and 7th levels of ribs. Statistical analyses were carried out to identify differences based on age and gender. It was found that, in comparison to males, females had significantly lower values for maximum bending moments, slopes of bending moment-angle curves, and average cortical-bone thickness (p<0.05). Samples of ribs taken from elderly specimens failed at lower values of fracture moments than those from younger specimens, and had lower slopes of bending moment-angle curves, both in males and females (p<0.05). The generalized estimated equations were developed to predict the values of biomechanical response and average cortical thickness based on age, gender, height and weight of individual specimens. Results from the current study illustrate that biomechanical responses and rib cortical thicknesses are functions of age, gender, height and weight. However, the current study is limited to a quasi-static loading scheme, which is different from real crash conditions. Hence, rib-material properties, which are dependent on strain rate, and are needed for wholebody finite element models representing different populations, still require more research.

Number of rib fractures thresholds independently predict worse outcomes in older patients with blunt trauma.

PubMed

Shulzhenko, Nikita O; Zens, Tiffany J; Beems, Megan V; Jung, Hee Soo; O'Rourke, Ann P; Liepert, Amy E; Scarborough, John E; Agarwal, Suresh K

2017-04-01

There have been conflicting reports regarding whether the number of rib fractures sustained in blunt trauma is associated independently with worse patient outcomes. We sought to investigate this risk-adjusted relationship among the lesser-studied population of older adults. A retrospective review of the National Trauma Data Bank was performed for patients with blunt trauma who were ≥65 years old and had rib fractures between 2009 and 2012 (N = 67,695). Control data were collected for age, sex, injury severity score, injury mechanism, 24 comorbidities, and number of rib fractures. Outcome data included hospital mortality, hospital and intensive care unit durations of stay, duration of mechanical ventilation, and the occurrence of pneumonia. Multiple logistic and linear regression analyses were performed. Sustaining ≥5 rib fractures was associated with increased intensive care unit admission (odds ratio: 1.14, P < .001) and hospital duration of stay (relative duration: 105%, P < .001). Sustaining ≥7 rib fractures was associated with an increased incidence of pneumonia (odds ratio: 1.32, P < .001) and intensive care unit duration of stay (relative duration: 122%, P < .001). Sustaining ≥8 rib fractures was associated with increased mortality (odds ratio: 1.51, P < .001) and duration of mechanical ventilation (relative duration: 117%, P < .001). In older patients with trauma, sustaining at least 5 rib fractures is a significant predictor of worse outcomes independent of patient characteristics, comorbidities, and trauma burden. Copyright © 2016 Elsevier Inc. All rights reserved.

The Role of Minimally Invasive Plate Osteosynthesis in Rib Fixation: A Review

PubMed Central

Bemelman, Michael; van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

2016-01-01

More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950’s, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation. Since the introduction of plate fixation for fractures, several plates and screws have been developed, all with their own characteristics. To accomplice more fracture stability, it was thought the bigger the plate, the better. The counter side was a compromised blood supply of the bone, often resulting in bone necrosis and ultimately delayed or non-union. With the search and development of new materials and techniques for fracture fixation, less invasive procedures have become increasingly popular. This resulted in the minimally invasive plate osteosynthesis (MIPO) technique for fracture fixation. With the MIPO technique, procedures could be performed with smaller incisions and thus with less soft tissue damage and a better preserved blood supply. The last 5 years rib fixation has become increasingly popular, rising evidence has become available suggesting that surgical rib fixation improves outcome of patients with a flail chest or isolated rib fractures. Many surgical approaches for rib fixation have been described in the old literature, however, most of these techniques are obscure nowadays. Currently mostly large incisions with considerable surgical insult are used to stabilize rib fractures. We think that MIPO deserves a place in the surgical treatment of rib fractures. We present the aspects of diagnosis, preoperative planning and operative techniques in regard to MIPO rib fixation. PMID:26889439

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ali, Elsayed

Purpose: To characterize and correct for radiation-induced background (RIB) observed in the signals from a class of scanning water tanks. Methods: A method was developed to isolate the RIB through detector measurements in the background-free linac console area. Variation of the RIB against a large number of parameters was characterized, and its impact on basic clinical data for photon and electron beams was quantified. Different methods to minimize and/or correct for the RIB were proposed and evaluated. Results: The RIB is due to the presence of the electrometer and connection box in a low background radiation field (by design). Themore » absolute RIB current with a biased detector is up to 2 pA, independent of the detector size, which is 0.6% and 1.5% of the central axis reference signal for a standard and a mini scanning chamber, respectively. The RIB monotonically increases with field size, is three times smaller for detectors that do not require a bias (e.g., diodes), is up to 80% larger for positive (versus negative) polarity, decreases with increasing photon energy, exhibits a single curve versus dose rate at the electrometer location, and is negligible for electron beams. Data after the proposed field-size correction method agree with point measurements from an independent system to within a few tenth of a percent for output factor, head scatter, depth dose at depth, and out-of-field profile dose. Manufacturer recommendations for electrometer placement are insufficient and sometimes incorrect. Conclusions: RIB in scanning water tanks can have a non-negligible effect on dosimetric data.« less

Evaluation of slot-to-slot coupling between dielectric slot waveguides and metal-insulator-metal slot waveguides.

PubMed

Kong, Deqing; Tsubokawa, Makoto

2015-07-27

We numerically analyzed the power-coupling characteristics between a high-index-contrast dielectric slot waveguide and a metal-insulator-metal (MIM) plasmonic slot waveguide as functions of structural parameters. Couplings due mainly to the transfer of evanescent components in two waveguides generated high transmission efficiencies of 62% when the slot widths of the two waveguides were the same and 73% when the waveguides were optimized by slightly different widths. The maximum transmission efficiency in the slot-to-slot coupling was about 10% higher than that in the coupling between a normal slab waveguide and an MIM waveguide. Large alignment tolerance of the slot-to-slot coupling was also proved. Moreover, a small gap inserted into the interface between two waveguides effectively enhances the transmission efficiency, as in the case of couplings between a normal slab waveguide and an MIM waveguide. In addition, couplings with very wideband transmissions over a wavelength region of a few hundred nanometers were validated.

The biomechanics of human ribs: material and structural properties from dynamic tension and bending tests.

PubMed

Kemper, Andrew R; McNally, Craig; Pullins, Clayton A; Freeman, Laura J; Duma, Stefan M; Rouhana, Stephen M

2007-10-01

The purpose of this study was to quantify both the tensile material properties and structural response of human ribs in order to determine which variables contribute to regional variation in the strength of human ribs. This was done by performing 94 matched tests on human rib specimens; 46 tension coupon tests, 48 three-point bending tests. Contralateral matched specimens were dissected from anterior and lateral regions of ribs 4 through 7 of six male fresh frozen post mortem human subjects ranging from 42 to 81 years of age. Tension coupons were taken from one side of the thorax, while three-point bending specimens were taken from the opposite side as the tension coupons at corresponding anatomical locations. The results of the tension coupon testing showed that there were no significant differences with respect to region or rib level: ultimate stress (p=0.90; p=0.53), ultimate strain (p=0.49; p=0.86), or modulus (p=0.72; p=0.81). In contrast, lateral three-point bending specimens were found to have a significantly higher peak bending moment (p<0.01), peak strain (p=0.03), modulus (p=0.05), and stiffness (p<0.01) than anterior specimens. The lateral three-point bending specimens also had a significantly larger area moment of inertia (p<0.01), larger distance to the neutral axis (p<0.01), smaller ratio of distance to the neutral axis to area moment of inertia (p<0.01), larger cortical bone area (p<0.01), and larger radius of gyration (p<0.01) than the anterior specimens. In addition, the peak moment (Ant p=0.20; Lat p=0.02), peak strain (Ant p=0.05; Lat p=0.15), and stiffness (Ant p<0.01; Lat p<0.01) were found to vary significantly with respect to rib level. Similar to anatomical region, the changes in the structural response with respect to rib level were also accompanied by significant changes in geometry. For anterior specimens, distance to the neutral axis (p<0.01), ratio of the distance to the neutral axis to area moment of inertia (p=0.02) and radius of gyration (p=0.04) were found to be significantly different with respect to rib level. For lateral specimens, the area moment of inertia (p<0.01), distance to the neutral axis (p<0.01), ratio of the distance to the neutral axis to area moment of inertia (p<0.01), the cortical bone area (p=0.01), and radius of gyration (p=0.03) were found to be significantly different with respect to rib level. These results clearly illustrate that there is variation in the structural response of human ribs with respect to anatomical region and rib level and this variation is due to changes in local geometry of each rib while the material properties remain constant.

Surgical resection of melorheostosis in the ribs.

PubMed

Chanda, Binayak; Millner, Russell W J

2007-04-01

Melorheostosis is a rare nongenetic developmental anomaly of the cortical bone. We present a 40-year-old woman who was diagnosed with melorheostosis affecting the ribs only. Chronic pain and cosmetic deformity were her presenting symptoms. She underwent posterolateral thoracotomy and excision of the affected ribs, with a satisfactory outcome of this uncommon presentation.

Does Cardiopulmonary Resuscitation Cause Rib Fractures in Children? A Systematic Review

ERIC Educational Resources Information Center

Maguire, Sabine; Mann, Mala; John, Nia; Ellaway, Bev; Sibert, Jo R.; Kemp, Alison M.

2006-01-01

Background: There is a diagnostic dilemma when a child presents with rib fractures after cardiopulmonary resuscitation (CPR) where child abuse is suspected as the cause of collapse. We have performed a systematic review to establish the evidence base for the following questions: (i) Does cardiopulmonary resuscitation cause rib fractures in…

Strategies to improve electrode positioning and safety in cochlear implants.

PubMed

Rebscher, S J; Heilmann, M; Bruszewski, W; Talbot, N H; Snyder, R L; Merzenich, M M

1999-03-01

An injection-molded internal supporting rib has been produced to control the flexibility of silicone rubber encapsulated electrodes designed to electrically stimulate the auditory nerve in human subjects with severe to profound hearing loss. The rib molding dies, and molds for silicone rubber encapsulation of the electrode, were designed and machined using AutoCad and MasterCam software packages in a PC environment. After molding, the prototype plastic ribs were iteratively modified based on observations of the performance of the rib/silicone composite insert in a clear plastic model of the human scala tympani cavity. The rib-based electrodes were reliably inserted farther into these models, required less insertion force and were positioned closer to the target auditory neural elements than currently available cochlear implant electrodes. With further design improvements the injection-molded rib may also function to accurately support metal stimulating contacts and wire leads during assembly to significantly increase the manufacturing efficiency of these devices. This method to reliably control the mechanical properties of miniature implantable devices with multiple electrical leads may be valuable in other areas of biomedical device design.

Large Eddy Simulation of Turbulent Flow in a Ribbed Pipe

NASA Astrophysics Data System (ADS)

Kang, Changwoo; Yang, Kyung-Soo

2011-11-01

Turbulent flow in a pipe with periodically wall-mounted ribs has been investigated by large eddy simulation with a dynamic subgrid-scale model. The value of Re considered is 98,000, based on hydraulic diameter and mean bulk velocity. An immersed boundary method was employed to implement the ribs in the computational domain. The spacing of the ribs is the key parameter to produce the d-type, intermediate and k-type roughness flows. The mean velocity profiles and turbulent intensities obtained from the present LES are in good agreement with the experimental measurements currently available. Turbulence statistics, including budgets of the Reynolds stresses, were computed, and analyzed to elucidate turbulence structures, especially around the ribs. In particular, effects of the ribs are identified by comparing the turbulence structures with those of smooth pipe flow. The present investigation is relevant to the erosion/corrosion that often occurs around a protruding roughness in a pipe system. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0008457).

Correction of cleft lip nose deformity with rib cartilage.

PubMed

Hafezi, Farhad; Naghibzadeh, Bijan; Ashtiani, Abbas Kazemi; Mousavi, S Jaber; Nouhi, Amir Hossein; Naghibzadeh, Ghazal

2013-07-01

Correction of cleft lip nasal deformities (CLND) is often unsatisfactory because of problems resulting from cartilage weakness and strong soft tissue forces. Therefore, strong cartilaginous support, such as rib cartilage, is mandatory. The authors describe placement of rib cartilage grafts to create a more symmetric and aesthetically acceptable repair of CLND with improved nasal air flow. Two groups of patients, including those with unilateral and bilateral CLND, underwent operations with different sources of autologous cartilage. Group 1 received grafts from the septum and ear, whereas group 2 received grafts from the septum and ribs. Results were evaluated by 2 independent physicians who rated improvement between pre- and postoperative photographs. There were significant differences in postoperative improvement between patients who received septal/ear cartilage grafts and those who received septal/rib cartilage grafts in both unilateral and bilateral cases (P = .028 and P = .043, respectively). The authors' results demonstrate that rib cartilage has a positive effect on the aesthetic outcome of CLND operations and provides a strong support structure for correcting this deformity with minimal postoperative complications.

Stress fractures of the ribs in elite competitive rowers: a report of nine cases.

PubMed

Dragoni, S; Giombini, A; Di Cesare, A; Ripani, M; Magliani, G

2007-10-01

The objective was to report the clinical and imaging patterns of nine cases of stress fractures of the rib diagnosed in Italian Olympic rowers. Nine patients with stress fractures of the rib detected from 103 (8.7%) Italian team rowers competing between May 2000 and May 2006 were identified based on the database of a sports medicine institute. All athletes were male. They were aged between 17 and 31 years (mean: 24.4). Patient weight, fracture location, rowing side and imaging methods employed were noted. The diagnosis was made based on history, clinical examination and Tc-99m MDP bone scintigraphy. Eight of the 9 fractures were located anterolaterally between the fourth and ninth rib. In 1 of the 5 athletes with standard radiographs, a fracture line was visible and in 4 there was callus formation. In 2 athletes sonography was performed, which detected discontinuity of the rib surface and callus formation (1 case each). Stress fractures of the ribs are relatively common in competitive rowers. They are characterized by increasing lateral chest pain and typical scintigraphic, radiographic and sonographic findings.

Slotted Polyimide-Aerogel-Filled-Waveguide Arrays

NASA Technical Reports Server (NTRS)

Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.

2013-01-01

Polyimide aerogels were considered to serve as a filling for millimeter-wave waveguides. While these waveguides present a slightly higher loss than hollow waveguides, they have less losses than Duroid substrate integrated waveguides (less than 0.15 dB at Ka-band, in a 20 mm section), and exhibit an order of magnitude of mass reduction when compared to commercial waveguides. A Ka-band slotted aerogel-filled-waveguide array was designed, which provided the same gain (9 dBi) as its standard waveguide counterpart, and a slotted aerogel-filled-waveguide array using folded-slots was designed for comparison, obtaining a gain of 9 dB and a bandwidth of 590 MHz.

Competition and evolution of dielectric waveguide mode and plasmonic waveguide mode

NASA Astrophysics Data System (ADS)

Yuan, Sheng-Nan; Fang, Yun-Tuan

2017-10-01

In order to study the coupling and evolution law of the waveguide mode and two plasmonic surface modes, we construct a line defect waveguide based on hexagonal honeycomb plasmonic photonic crystal. Through adjusting the radius of the edge dielectric rods, the competition and evolution behaviors occur between dielectric waveguide mode and plasmonic waveguide mode. There are three status: only plasmonic waveguide modes occur for rA < 0.09a; only dielectric waveguide modes occur for rA > 0.25a; two kinds of modes coexist for 0.09a < rA < 0.25a. The plasmonic waveguide mode has advantages in achieving slow light.

Histology shows that elongated neck ribs in sauropod dinosaurs are ossified tendons.

PubMed

Klein, Nicole; Christian, Andreas; Sander, P Martin

2012-12-23

The histology of cervical ribs of Sauropoda reveals a primary bone tissue, which largely consists of longitudinally oriented mineralized collagen fibres, essentially the same tissue as found in ossified tendons. The absence of regular periosteal bone and the dominance of longitudinal fibres contradict the ventral bracing hypothesis (VBH) postulated for sauropod necks. The VBH predicts histologically primary periosteal bone with fibres oriented perpendicular to the rib long axis, indicative of connective tissue between overlapping hyperelongated cervical ribs. The transformation of the cervical ribs into ossified tendons makes the neck more flexible and implies that tension forces acted mainly along the length of the neck. This is contrary to the VBH, which requires compressive forces along the neck. Tension forces would allow important neck muscles to shift back to the trunk region, making the neck much lighter.

Histology shows that elongated neck ribs in sauropod dinosaurs are ossified tendons

PubMed Central

Klein, Nicole; Christian, Andreas; Sander, P. Martin

2012-01-01

The histology of cervical ribs of Sauropoda reveals a primary bone tissue, which largely consists of longitudinally oriented mineralized collagen fibres, essentially the same tissue as found in ossified tendons. The absence of regular periosteal bone and the dominance of longitudinal fibres contradict the ventral bracing hypothesis (VBH) postulated for sauropod necks. The VBH predicts histologically primary periosteal bone with fibres oriented perpendicular to the rib long axis, indicative of connective tissue between overlapping hyperelongated cervical ribs. The transformation of the cervical ribs into ossified tendons makes the neck more flexible and implies that tension forces acted mainly along the length of the neck. This is contrary to the VBH, which requires compressive forces along the neck. Tension forces would allow important neck muscles to shift back to the trunk region, making the neck much lighter. PMID:23034173

Preoperative Embolization in Surgical Treatment of a Primary Hemangiopericytoma of the Rib : A Case Report

PubMed Central

Akan, Huseyin; Baris, Sancar; Atici, Atilla G.; Uzun, Oguz; Erkan, Levent

2005-01-01

Primary hemangiopericytoma of the rib is extremely rare and only a few cases have been reported. A 62-yr-old man presented with an aching chest pain and dyspnea. Thoracic computed tomography revealed a homogenous mass expanding the right seventh rib. A diagnosis of hemangiopericytoma was established by percutaneous needle biopsy. Preoperative embolization of the feeding vessels of the tumor was performed in order to prevent perioperative bleeding. There was no significant bleeding during the surgery, where complete resection of the tumor with 7th to 9th ribs with a surgical margin of 5 cm was performed. Postoperative course was uneventful and there has been no recurrence for thirteen months. To our knowledge, there has been no report to apply a preoperative embolization of a primary hemangiopericytoma of the rib. PMID:15832008

Daylighting and shuttering: RIB system mechanical design and preliminary performance data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinney, L.; Reynolds, D.

1983-12-01

The Reflective, Insulating Blind (RIB) system is a flexible, user-controlled daylighting device which also has direct thermal advantages: it can reject a considerable portion of summer sun while still retaining an adequate daylighting function; and it functions as moveable insulation to significantly decrease thermal losses through fenestration during evening hours. The conceptual design of the RIB system was accomplished by Barnes and Shapira at the Oak Ridge National Laboratory (ORNL). Mechanical design and prototype fabrication was accomplished by the authors and 29 systems were installed immediately inside existing south-facing windows of an energy-efficient office and dormitory at ORNL. The buildingmore » is a heavily-instrumented, passively-solar-heated structure for which reliable performance data was gathered and analyzed before the addition of RIB systems, thus facilitating the interpretation of ''after RIB'' performance data.« less

Operative Fixation of Rib Fractures Indications, Techniques, and Outcomes.

PubMed

Galos, David; Taylor, Benjamin; McLaurin, Toni

2017-01-01

Rib fractures are extremely common injuries and vary in there severity from single nondisplaced fractures to multiple segmental fractures resulting in flail chest and respiratory compromise. Historically, rib fractures have been treated conservatively with pain control and respiratory therapy. However this method may not be the best treatment modality in all situations. Operative fixation of select rib fractures has been increasing in popularity especially in patients with flail chest and respiratory compromise. Newer techniques use muscle sparing approaches and precontoured locking plate technology to obtain stable fixation and allow improved respiration. Current reports shows that rib fracture fixation offers the benefits of improved respiratory mechanics and improved pain control in the severe chest wall injury with resultant improvement in patient outcomes by decreasing time on the ventilator, time in the intensive care unit, and overall hospital length of stay.

Biosorbable poly-L-lactide rib-connecting pins may reduce acute pain after thoracotomy.

PubMed

Iwasaki, A; Hamatake, D; Shirakusa, T

2004-02-01

Conventional thoracotomy is currently used as a standard procedure, and is often required to treat numerous diseases. Additionally, rib resections are occasionally required to maintain an adequate field of view for surgery. The benefits of using rib pins for chest closure following such procedures have not yet been established. This study sought to evaluate the usefulness of rib pins in reducing acute postoperative pain. Thirty-three consecutive patients with lung cancer underwent lobectomies using the posterolateral approach. The patients were rib-resected and reconstructed with two techniques: 21 patients with absorbable rib pins (ARP group) and 12 patients by ligation with absorbable sutures (LAS group). Intensity of pain was assessed during the 3 days immediately following surgery. The two groups were assessed using the visual analogue scale (VAS) as a pain scale, amounts consumed of patient-controlled analgesics (PCA), and additional chest x-rays. On the first day following surgery, the mean VAS intensity of the ARP group for patient motion was 2.71 +/- 2.14, compared to 5.33 +/- 2.99 in the LAS group. After three days, the mean score for the ARP group was 1.98 +/- 1.89, compared to 4.60 +/- 1.97 in the LAS group. Scores in the ARP group were significantly lower than in the LAS group one day and three days following thoracotomy. The LAS group (55.0 +/- 15.9 times) made more frequent requests than the ARP group (16.1 +/- 10.3 times). The PCA requirement was also significantly lower in the ARP group. Excessive derangement of the rib (grade 2) was found in one case (4.7 %) in the ARP group compared to five cases (41.6 %) in the LAS group. Rib shifts were seen in numerous cases in the LAS group compared to the ARP group as measured by chest x-rays. Use of absorbable rib pins reduced postoperative pain and may improve long-term prospects for the post-thoracotomy course.

Use of the S-hook for Pelvic Fixation in Rib-Based Treatment of Early-Onset Scoliosis: A Multicenter Study.

PubMed

Ramirez, Norman; Flynn, John M; Smith, John T; Vitale, Michael; Sturm, Peter F; DʼAmato, Charles; Samdani, Amer; Machiavelli, Raul; El-Hawary, Ron

2015-06-01

Retrospective review. The purpose of this study was to evaluate how several preoperative variables affect the outcome using the rib-to-pelvis S-hook constructs of a rib-based distraction implant (Vertical Expandable Prosthetic Titanium Rib). Rib-to-pelvis fixation with S-hooks is one of the options for distal anchoring of rib-based distraction growing rod construct to control early-onset spinal deformity. Since the initial report, the indications of pelvic fixation with S-hooks have been extended and modified. This is an institutional review board-approved retrospective study of patients who underwent rib-based growing rod system surgery-rib-to-pelvis construct with Dunn-McCarthy S-hook. Data evaluation included history, physical examination, preoperative and postoperative radiographs, surgical variables, and complications. Sixty-five patients were evaluated; 38 were male and 27 were female. Mean age at initial procedure was 71 months. The mean follow-up was 46 months. There was a statistically significant improvement of the immediate postoperative Cobb angle and the last follow-up Cobb angle (P < 0.0001). Fifty percent of the patients (32/65) had S-hook-related complications. The most common complication was sliding of the S-hook out of the iliac crest, followed by infection, neuropathic pain, distal migration of more than 2 cm, fracture of the hook, and bursitis. The complications were related to the preoperative ambulatory status, the use of end-to-end rod connectors, surgical time, and not positioning the hook over the central one-third of the iliac crest at the initial implantation. The use of the S-hook as a pelvic attachment of the rib-based system is indicated in nonambulatory patients with progressive, early-onset scoliosis curve with a lack of adequate anchor at the lumbar spine. Several technical factors should be considered to reduce the complication rate. 3.

The costal skeleton of the Regourdou 1 Neandertal.

PubMed

Gómez-Olivencia, Asier; Holliday, Trenton; Madelaine, Stéphane; Couture-Veschambre, Christine; Maureille, Bruno

2018-02-26

The morphology and size of the Neandertal thorax is a subject of growing interest due to its link to general aspects of body size and shape, including physiological aspects related to bioenergetics and activity budgets. However, the number of well-preserved adult Neandertal costal remains is still low. The recent finding of new additional costal remains from the Regourdou 1 (R1) skeleton has rendered this skeleton as one of the most complete Neandertal costal skeletons with a minimum of 18 ribs represented, five of which are complete or virtually complete. Here we describe for the first time all the rib remains from R1 and compare them to a large modern Euroamerican male sample as well as to other published Neandertal individuals. The costal skeleton of this individual shows significant metric and morphological differences from our modern human male comparative sample. The perceived differences include: dorsoventrally large 1st and 2nd ribs, 3rd ribs with a very closed dorsal curvature and large maximum diameters at the posterior angle, a large tubercle-iliocostal line distance in the 4th rib, thick shafts at the dorsal end of its 6th ribs, thick mid-shafts of the 8th ribs, large articular tubercles at the 9th ribs, and thick shafts of the 11th and 12th ribs. Here we also describe a new mesosternal fragment: the left lateral half of sternebral segments 4 and 5. This portion reveals that the mesosternum of R1 had a sternal foramen in its inferiormost preserved sternal segment and supports previous estimation of the total length of this mesosternum. The new costal remains from R1 support the view that Neandertals, when compared with modern humans, show a significantly different thorax, consistent with differences found in other anatomical regions such as the vertebral column and pelvis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Isolated Traumatic Bilateral First Rib Fracture: A Rare Entity

PubMed Central

Chatterjee, Souvik; Dey, Rajesh; Ray, Ramdip; Sinha, Santanu

2011-01-01

Since the first rib is protected very well by the overlying soft tissue and bones, its fracture is a major injury and a considerable force is required to do it. Therefore, an isolated fracture of this rib is unusual. A 28-year-old healthy female had an accident while crossing the road and a heavy object fell on her. She had severe pain behind her clavicle region and was immediately hospitalized and examined. Thorough clinical examination and different relevant investigations surprisingly disclosed isolated bilateral first rib fracture which is a very rare clinical condition. PMID:25191390

CONSTRUCTION OF NUCLEAR FUEL ELEMENTS

DOEpatents

Weems, S.J.

1963-09-24

>A rib arrangement and an end construction for nuclearfuel elements laid end to end in a coolant tube are described. The rib arrangement is such that each fuel element, when separated from other fuel elements, fits loosely in the coolant tube and so can easily be inserted or withdrawn from the tube. The end construction of the fuel elements is such that the fuel elements when assembled end to end are keyed against relative rotation, and the ribs of each fuel element cooperate with the ribs of the adjacent fuel elements to give the assembled fuel elements a tight fit with the coolant tube. (AEC)

Significance of Rib Fractures Potentially Caused by Blunt Impact Non Lethal Weapons

DTIC Science & Technology

2017-03-01

Center Drive Alexandria, Virginia 22311-1882 I N S T I T U T E F O R D E F E N S E A N A L Y S E S Significance of Rib Fractures Potentially...F E N S E A N A L Y S E S IDA Document D-8277 Significance of Rib Fractures Potentially Caused by Blunt-Impact Non-Lethal Weapons Shelley M. Cazares...deterrent by inducing pain or muscle spasm at the site of impact of the affected individual. These weapons may induce rib fractures —the focus of this

Magnetic resonance-guided shielding of prefocal acoustic obstacles in focused ultrasound therapy: application to intercostal ablation in liver.

PubMed

Salomir, Rares; Petrusca, Lorena; Auboiroux, Vincent; Muller, Arnaud; Vargas, Maria-Isabel; Morel, Denis R; Goget, Thomas; Breguet, Romain; Terraz, Sylvain; Hopple, Jerry; Montet, Xavier; Becker, Christoph D; Viallon, Magalie

2013-06-01

The treatment of liver cancer is a major public health issue because the liver is a frequent site for both primary and secondary tumors. Rib heating represents a major obstacle for the application of extracorporeal focused ultrasound to liver ablation. Magnetic resonance (MR)-guided external shielding of acoustic obstacles (eg, the ribs) was investigated here to avoid unwanted prefocal energy deposition in the pathway of the focused ultrasound beam. Ex vivo and in vivo (7 female sheep) experiments were performed in this study. Magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) was performed using a randomized 256-element phased-array transducer (f∼1 MHz) and a 3-T whole-body clinical MR scanner. A physical mask was inserted in the prefocal beam pathway, external to the body, to block the energy normally targeted on the ribs. The effectiveness of the reflecting material was investigated by characterizing the efficacy of high-intensity focused ultrasound beam reflection and scattering on its surface using Schlieren interferometry. Before high-intensity focused ultrasound sonication, the alignment of the protectors with the conical projections of the ribs was required and achieved in multiple steps using the embedded graphical tools of the MR scanner. Multiplanar near real-time MR thermometry (proton resonance frequency shift method) enabled the simultaneous visualization of the local temperature increase at the focal point and around the exposed ribs. The beam defocusing due to the shielding was evaluated from the MR acoustic radiation force impulse imaging data. Both MR thermometry (performed with hard absorber positioned behind a full-aperture blocking shield) and Schlieren interferometry indicated a very good energy barrier of the shielding material. The specific temperature contrast between rib surface (spatial average) and focus, calculated at the end point of the MRgHIFU sonication, with protectors vs no protectors, indicated an important reduction of the temperature elevation at the ribs' surface, typically by 3.3 ± 0.4 in vivo. This was translated into an exponential reduction in thermal dose by several orders of magnitude. The external shielding covering the full conical shadow of the ribs was more effective when the protectors could be placed close to the ribs' surface and had a tendency to lose its efficiency when placed further from the ribs. Hepatic parenchyma was safely ablated in vivo using this rib-sparing strategy and single-focus independent sonications. A readily available, MR-compatible, effective, and cost-competitive method for rib protection in transcostal MRgHIFU was validated in this study, using specific reflective strips. The current approach permitted safe intercostal ablation of small volumes (0.7 mL) of liver parenchyma.

Study of the temperature rise induced by a focusing transducer with a wide aperture angle on biological tissue containing ribs

NASA Astrophysics Data System (ADS)

Xin, Wang; Jiexing, Lin; Xiaozhou, Liu; Jiehui, Liu; Xiufen, Gong

2016-04-01

We used the spheroidal beam equation to calculate the sound field created by focusing a transducer with a wide aperture angle to obtain the heat deposition, and then we used the Pennes bioheat equation to calculate the temperature field in biological tissue with ribs and to ascertain the effects of rib parameters on the temperature field. The results show that the location and the gap width between the ribs have a great influence on the axial and radial temperature rise of multilayer biological tissue. With a decreasing gap width, the location of the maximum temperature rise moves forward; as the ribs are closer to the transducer surface, the sound energy that passes through the gap between the ribs at the focus decreases, the maximum temperature rise decreases, and the location of the maximum temperature rise moves forward with the ribs. Project supported by the National Basic Research Program of China (Grant Nos. 2012CB921504 and 2011CB707902), the National Natural Science Foundation of China (Grant No. 11274166), the Fundamental Research Funds for the Central Universities, China (Grant No. 020414380001), the Fund from State Key Laboratory of Acoustics, Chinese Academy of Sciences (Grant No. SKLA201401), China Postdoctoral Science Foundation (Grant No. 2013M531313), and the Priority Academic Program Development of Jiangsu Higher Education Institutions and SRF for ROCS, SEM.

Arrangement of Cellulose Microfibrils in Walls of Elongating Parenchyma Cells

PubMed Central

Setterfield, G.; Bayley, S. T.

1958-01-01

The arrangement of cellulose microfibrils in walls of elongating parenchyma cells of Avena coleoptiles, onion roots, and celery petioles was studied in polarizing and electron microscopes by examining whole cell walls and sections. Walls of these cells consist firstly of regions containing the primary pit fields and composed of microfibrils oriented predominantly transversely. The transverse microfibrils show a progressive disorientation from the inside to the outside of the wall which is consistent with the multinet model of wall growth. Between the pit-field regions and running the length of the cells are ribs composed of longitudinally oriented microfibrils. Two types of rib have been found at all stages of cell elongation. In some regions, the wall appears to consist entirely of longitudinal microfibrils so that the rib forms an integral part of the wall. At the edges of such ribs the microfibrils can be seen to change direction from longitudinal in the rib to transverse in the pit-field region. Often, however, the rib appears to consist of an extra separate layer of longitudinal microfibrils outside a continuous wall of transverse microfibrils. These ribs are quite distinct from secondary wall, which consists of longitudinal microfibrils deposited within the primary wall after elongation has ceased. It is evident that the arrangement of cellulose microfibrils in a primary wall can be complex and is probably an expression of specific cellular differentiation. PMID:13563544

Frequency of rib and sternum fractures associated with out-of-hospital cardiopulmonary resuscitation is underestimated by conventional chest X-ray.

PubMed

Lederer, Wolfgang; Mair, Dieter; Rabl, Walter; Baubin, Michael

2004-02-01

Fractured ribs and sternum are frequent complications of thoracic compression during CPR in adults. This study was conducted to determine whether findings of plain chest radiography (CXR) correlate with post-mortem findings in patients who underwent cardiopulmonary resuscitation (CPR) after out-of-hospital cardiac arrest. CXR findings and autopsy results of CPR-related chest injuries comprising rib and sternum fractures were compared prospectively in 19 patients. Fractures were diagnosed in nine of 19 patients by means of radiology and in 18 of 19 patients by autopsy (rib fractures in 6/19 versus 17/19, P=0.002; sternum fractures in 5/19 versus in 9/19, P=0.227. The total number of isolated bone fractures detected by CXR was 18 (12 rib and six sternum fractures) and by autopsy 92 (83 rib and nine sternum fractures). The majority of rib fractures was located in the anterior part of the thoracic cage. Sternum fractures predominantly occurred in the lower third. Eight of 19 patients received either thrombolytic or antithrombotic treatment during CPR but no major bleeding complication associated with CPR was detected by autopsy. The findings of this study indicate that fractures associated with CPR are underreported in conventional radiographic investigations. No major bleeding complications related to CPR-associated fractures was detected.

Application of fracture mechanics to failure in manatee rib bone.

PubMed

Yan, Jiahau; Clifton, Kari B; Reep, Roger L; Mecholsky, John J

2006-06-01

The Florida manatee (Trichechus manatus latirostris) is listed as endangered by the U.S. Department of the Interior. Manatee ribs have different microstructure from the compact bone of other mammals. Biomechanical properties of the manatee ribs need to be better understood. Fracture toughness (K(C)) has been shown to be a good index to assess the mechanical performance of bone. Quantitative fractography can be used in concert with fracture mechanics equations to identify fracture initiating defects/cracks and to calculate the fracture toughness of bone materials. Fractography is a standard technique for analyzing fracture behavior of brittle and quasi-brittle materials. Manatee ribs are highly mineralized and fracture in a manner similar to quasi-brittle materials. Therefore, quantitative fractography was applied to determine the fracture toughness of manatee ribs. Average fracture toughness values of small flexure specimens from six different sizes of manatees ranged from 1.3 to 2.6 MPa(m)(12). Scanning electron microscope (SEM) images show most of the fracture origins were at openings for blood vessels and interlayer spaces. Quantitative fractography and fracture mechanics can be combined to estimate the fracture toughness of the material in manatee rib bone. Fracture toughness of subadult and calf manatees appears to increase as the size of the manatee increases. Average fracture toughness of the manatee rib bone materials is less than the transverse fracture toughness of human and bovine tibia and femur.

Orbit transfer rocket engine technology program enhanced heat transfer combustor technology

NASA Technical Reports Server (NTRS)

Brown, William S.

1991-01-01

In order to increase the performance of a high performance, advanced expander-cycle engine combustor, higher chamber pressures are required. In order to increase chamber pressure, more heat energy is required to be transferred to the combustor coolant circuit fluid which drives the turbomachinery. This requirement was fulfilled by increasing the area exposed to the hot-gas by using combustor ribs. A previous technology task conducted 2-d hot air and cold flow tests to determine an optimum rib height and configuration. In task C.5 a combustor calorimeter was fabricated with the optimum rib configuration, 0.040 in. high ribs, in order to determine their enhancing capability. A secondary objective was to determine the effects of mixture ratio changers on the enhancement during hot-fire testing. The program used the Rocketdyne Integrated Component Evaluator (ICE) reconfigured into a thrust chamber only mode. The test results were extrapolated to give a projected enhancement from the ribs for a 16 in. long cylindrical combustor at 15 Klb nominal thrust level. The hot-gas wall ribs resulted in a 58 percent increase in heat transfer. When projected to a full size 15K combustor, it becomes a 46 percent increase. The results of those tests, a comparison with previous 2-d results, the effects of mixture ratio and combustion gas flow on the ribs and the potential ramifications for expander cycle combustors are detailed.

Comparing and determining the causes of ribbed mussel nitrogen isotope signatures in three New England sub-watersheds

EPA Science Inventory

Geukensia demissa, the ribbed mussel, is a useful indicator of sources of nitrogen input into coastal watersheds as it possesses a slow tissue turnover rate and is a common salt marsh species. During the summer of 2016, we sampled ribbed mussels from three New England sub-watersh...

Microbiological safety of commercial prime rib preparation methods: thermal inactivation of Salmonella spp. in mechanically tenderized beef roasts

USDA-ARS?s Scientific Manuscript database

A survey of food service operations in a medium-size Midwestern city was conducted to evaluate the microbiological safety of prime rib preparation methods relative to survival of Salmonella spp. in both intact and tenderized (non-intact) product. All six restaurants visited seared rib eye roasts (ai...

Waveguide-mode polarization gaps in square spiral photonic crystals

NASA Astrophysics Data System (ADS)

Liu, Rong-Juan; John, Sajeev; Li, Zhi-Yuan

2015-09-01

We designed waveguide channels in two types of square spiral photonic crystals. Wide polarization gaps, in which only one circular polarization wave is allowed while the other counter-direction circular polarization wave is forbidden, can be opened up on the waveguide modes within the fundamental photonic band gap according to the calculation of band structures and transmission spectra. This phenomenon is ascribed to the chirality of the waveguide and is independent of the chirality of the background photonic crystal. Moreover, the transmission spectra show a good one-way property of the waveguide channels. The chiral quality factor demonstrates the handedness of the allowed and impeded chiral waveguide modes, and further proved the property of the waveguide-mode polarization gap. Such waveguides with waveguide-mode polarization gap are a good candidate for one-way waveguides with robust backscattering-immune transport.

Experimental investigation of cross-over jets in a rib-roughened trailing-edge cooling channel

NASA Astrophysics Data System (ADS)

Xue, Fei

Increasing the rotor inlet temperature can dramatically increase the efficiency and power output of the gas turbine engine. However, the melting point of turbine blade material limits the realistic upper bound of the rotor inlet temperature. As a result, the development of high temperature turbine blade material and advanced turbine blade cooling technology determines the future of turbine blade engine. Adding impingement jet holes and rib turbulators in the inner cooling channel of the gas turbine blades are two effective ways to enhance the cooling effects. The purpose of this study is to figure out the influence of different combinations of jet holes and rib turbulators on the heat transfer efficiency. A tabletop scale test model is used in the study to simulate the cooling cavity of trailing edge and its feed channel in a real gas turbine blade. The Dimensional Analysis Theory is used in the study to eliminate the influence of scaling. Two different crossover slots are tested with 5 different rib arrangements, and each of the test geometries is tested for 6 jet Reynolds numbers ranging from 10,000 to 36,000. The two different crossover slots are the crossover slots with 0 and 5 degree tilt angles. The four different rib arrangements are ribs with 0 degree, 45 degree, 90 degree and 135 degree angles of attack with respect to the flow direction. Furthermore, a smooth test section (no ribs) was also tested. The steady state liquid crystal thermography is used to quantify the heat transfer performance of the target areas. The variation of Nusselt number versus Reynolds number is plotted for each of the 10 geometries. Also, the variation of Nusselt number versus Reynolds number are compared for different rib angles of attack with the same crossover slot tilt angle, and between different crossover slots tilt angles with the same rib angle. The results show that, the area-weighted average Nusselt number increases monotonically with the Reynolds number; the target areas near the open end have a larger Nusselt number comparing with the ones near the close end; the 90 degree rib angle has the highest Nusselt number among the 4 rib angles of attack and the smooth wall channel; the crossover slots with 0 degree tilt angle produce higher convective heat transfer coefficients than the crossover slots with 5 degree tilt angle. Possible physical explanations for the result are offered by the author.

Multimode Directional Coupler

NASA Technical Reports Server (NTRS)

Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor)

2016-01-01

A multimode directional coupler is provided. In some embodiments, the multimode directional coupler is configured to receive a primary signal and a secondary signal at a first port of a primary waveguide. The primary signal is configured to propagate through the primary waveguide and be outputted at a second port of the primary waveguide. The multimode directional coupler also includes a secondary waveguide configured to couple the secondary signal from the primary waveguide with no coupling of the primary signal into the secondary waveguide. The secondary signal is configured to propagate through the secondary waveguide and be outputted from a port of the secondary waveguide.

The role of acoustic nonlinearity in tissue heating behind a rib cage using a high-intensity focused ultrasound phased array

NASA Astrophysics Data System (ADS)

Yuldashev, Petr V.; Shmeleva, Svetlana M.; Ilyin, Sergey A.; Sapozhnikov, Oleg A.; Gavrilov, Leonid R.; Khokhlova, Vera A.

2013-04-01

The goal of this study was to investigate theoretically the effects of nonlinear propagation in a high-intensity focused ultrasound (HIFU) field produced by a therapeutic phased array and the resultant heating of tissue behind a rib cage. Three configurations of focusing were simulated: in water, in water with ribs in the beam path and in water with ribs backed by a layer of soft tissue. The Westervelt equation was used to model the nonlinear HIFU field, and a 1 MHz phased array consisting of 254 circular elements was used as a boundary condition to the model. The temperature rise in tissue was modelled using the bioheat equation, and thermally necrosed volumes were calculated using the thermal dose formulation. The shapes of lesions predicted by the modelling were compared with those previously obtained in in vitro experiments at low-power sonications. Intensity levels at the face of the array elements that corresponded to the formation of high-amplitude shock fronts in the focal region were determined as 10 W cm-2 in the free field in water and 40 W cm-2 in the presence of ribs. It was shown that exposures with shocks provided a substantial increase in tissue heating, and its better spatial localization in the main focal region only. The relative effects of overheating ribs and splitting of the focus due to the periodic structure of the ribs were therefore reduced. These results suggest that utilizing nonlinear propagation and shock formation effects can be beneficial for inducing confined HIFU lesions when irradiating through obstructions such as ribs. Design of compact therapeutic arrays to provide maximum power outputs with lower intensity levels at the elements is necessary to achieve shock wave regimes for clinically relevant sonication depths in tissue.

SpaRibs Geometry Parameterization for Wings with Multiple Sections using Single Design

NASA Technical Reports Server (NTRS)

De, Shuvodeep; Jrad, Mohamed; Locatelli, Davide; Kapania, Rakesh K.; Baker, Myles; Pak, Chan-Gi

2017-01-01

The SpaRibs topology of an aircraft wing has a significant effect on its structural behavior and stability as well as the flutter performance. The development of additive manufacturing techniques like Electron Beam Free Form Fabrication (EBF3) has made it feasible to manufacture aircraft wings with curvilinear spars, ribs (SpaRibs) and stiffeners. In this article a new global-local optimization framework for wing with multiple sections using curvilinear SpaRibs is described. A single design space is used to parameterize the SpaRibs geometry. This method has been implemented using MSC-PATRAN to create a broad range of SpaRibs topologies using limited number of parameters. It ensures C0 and C1 continuities in SpaRibs geometry at the junction of two wing sections with airfoil thickness gradient discontinuity as well as mesh continuity between all structural components. This method is advantageous in complex multi-disciplinary optimization due to its potential to reduce the number of design variables. For the global-local optimization the local panels are generated by an algorithm which is totally based on a set algebra on the connectivity matrix data. The great advantage of this method is that it is completely independent of the coordinates of the nodes of the finite element model. It is also independent of the order in which the elements are distributed in the FEM. The code is verified by optimizing of the CRM Baseline model at trim condition at Mach number equal to 0.85 for five different angle of attack (-2deg, 0deg,2deg,4deg and 6deg). The final weight of the wing is 19,090.61 lb. This value is comparable to that obtained by Qiang et al. 6 (19,269 lb).

The role of acoustic nonlinearity in tissue heating behind the rib cage using high intensity focused ultrasound phased array

PubMed Central

Yuldashev, Petr V.; Shmeleva, Svetlana M.; Ilyin, Sergey A.; Sapozhnikov, Oleg A.; Gavrilov, Leonid R.; Khokhlova, Vera A.

2013-01-01

The goal of this study was to investigate theoretically the effects of nonlinear propagation in a high intensity focused ultrasound (HIFU) field produced by a therapeutic phased array and the resultant heating of tissue behind a rib cage. Three configurations of focusing were simulated: in water, in water with ribs in the beam path, and in water with ribs backed by a layer of soft tissue. The Westervelt equation was used to model the nonlinear HIFU field and a 1 MHz phased array consisting of 254 circular elements was used as a boundary condition to the model. The temperature rise in tissue was modelled using the bioheat equation, and thermally necrosed volumes were calculated using the thermal dose formulation. The shapes of lesions predicted by the modelling were compared with those previously obtained in in vitro experiments at low power sonications. Intensity levels at the face of the array elements that corresponded to formation of high amplitude shock fronts in the focal region were determined as 10 W·cm−2 in the free field in water and 40 W·cm−2 in the presence of ribs. It was shown that exposures with shocks provided a substantial increase in tissue heating, and its better spatial localization in the main focal region only. The relative effects of overheating ribs and splitting of the focus due to the periodic structure of the ribs were therefore reduced. These results suggest that utilizing nonlinear propagation and shock formation effects can be beneficial for inducing confined HIFU lesions when irradiating through obstructions such as ribs. Design of compact therapeutic arrays to provide maximum power outputs with lower intensity levels at the elements is necessary to achieve shock wave regimes for clinically relevant sonication depths in tissue. PMID:23528338

Fine structure of the 21S ribosomal RNA region on yeast mitochondrial DNA. III. Physical location of mitochondrial genetic markers and the molecular nature of omega.

PubMed

Heyting, C; Menke, H H

1979-01-11

1. We have determined the physical location of mitochondrial genetic markers in the 21S region of yeast mtDNA by genetic analysis of petite mutants whose mtDNA has been physically mapped on the wild-type mtDNA. 2. The order of loci, determined in this study, is in agreement with the order deduced from recombination analysis and coretention analysis except for the position of omega+: we conclude that omega+ is located between C321 (RIB-1) and E514 (RIB-3). 3. The marker E514 (RIB-3) has been localized on a DNA segment of 3800 bp, and the markers E354, E553 and cs23 (RIB-2) on a DNA segment of 1100 base pairs; both these segments overlap the 21S rRNA cistron. The marker C321 (RIB-1) has been localized within a segment of 240 bp which also overlaps the 21S rRNA cistron, and we infer on the basis of indirect evidence that this marker lies within this cistron. 4. In all our rho+ as well as rho- strains there is a one-to-one correlation between the omega+ phenotype, the ability to transmit the omega+ allele and the presence of a mtDNA segment of about 1000 bp long, located between sequences specifying RIB-3 and sequences corresponding to the loci RIB-1 and RIB-2. This segment may be inserted at this same position into omega- mtDNA by recombination. 5. The role which the different allelic forms of omega may play in the polarity of recombination is discussed.

Microbiological Safety of Commercial Prime Rib Preparation Methods: Thermal Inactivation of Salmonella in Mechanically Tenderized Rib Eye.

PubMed

Calle, Alexandra; Porto-Fett, Anna C S; Shoyer, Bradley A; Luchansky, John B; Thippareddi, Harshavardhan

2015-12-01

Boneless beef rib eye roasts were surface inoculated on the fat side with ca. 5.7 log CFU/g of a five-strain cocktail of Salmonella for subsequent searing, cooking, and warm holding using preparation methods practiced by restaurants surveyed in a medium-size Midwestern city. A portion of the inoculated roasts was then passed once through a mechanical blade tenderizer. For both intact and nonintact roasts, searing for 15 min at 260°C resulted in reductions in Salmonella populations of ca. 0.3 to 1.3 log CFU/g. For intact (nontenderized) rib eye roasts, cooking to internal temperatures of 37.8 or 48.9°C resulted in additional reductions of ca. 3.4 log CFU/g. For tenderized (nonintact) rib eye roasts, cooking to internal temperatures of 37.8 or 48.9°C resulted in additional reductions of ca. 3.1 or 3.4 log CFU/g, respectively. Pathogen populations remained relatively unchanged for intact roasts cooked to 37.8 or 48.9°C and for nonintact roasts cooked to 48.9°C when held at 60.0°C for up to 8 h. In contrast, pathogen populations increased ca. 2.0 log CFU/g in nonintact rib eye cooked to 37.8°C when held at 60.0°C for 8 h. Thus, cooking at low temperatures and extended holding at relatively low temperatures as evaluated herein may pose a food safety risk to consumers in terms of inadequate lethality and/or subsequent outgrowth of Salmonella, especially if nonintact rib eye is used in the preparation of prime rib, if on occasion appreciable populations of Salmonella are present in or on the meat, and/or if the meat is not cooked adequately throughout.

Rib fractures in chronic alcoholic men: Relationship with feeding habits, social problems, malnutrition, bone alterations, and liver dysfunction.

PubMed

González-Reimers, Emilio; García-Valdecasas-Campelo, Elena; Santolaria-Fernández, Francisco; Milena-Abril, Antonio; Rodríguez-Rodríguez, Eva; Martínez-Riera, Antonio; Pérez-Ramírez, Alina; Alemán-Valls, María Remedios

2005-10-01

Rib fractures are common in alcoholics. This high prevalence might be due to ethanol-associated malnutrition, bone disease, liver dysfunction, or the peculiar lifestyle of the alcoholic with frequent trauma and altercations. In this study we try to discern the role of these factors on rib fracture (assessed on a plain thoracic X-ray film) in 81 consecutive alcoholic patients, 25 of them cirrhotics. Serum albumin, prothrombin aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), gamma-glutamyl transpeptidase, C-terminal cross-linking telopeptide of type 1 collagen, osteocalcin, insulin growth factor 1, 1,25-dihydroxyvitamin D, parathyroid hormone, estradiol, free testosterone, and corticosterone were measured, and the patients also underwent assessment of bone mineral density by a HOLOGIC QDR-2000 bone densitometer (Waltham, MA, USA). Body mass index, triceps skinfold, and brachial perimeter were also determined, and the patients and their families were asked about tobacco consumption, social and familial links, consumption of ethanol by other members of the family, kind of job, and feeding habits. Forty-two male nondrinker sanitary workers of similar age served as controls. Forty of the 81 patients showed rib fractures. There was a statistically significant association between rib fractures and disruption of social and familial links, irregular feeding habits (in bars or pubs, not at home), ethanol consumption by close relatives, and intensity of tobacco consumption, but not between rib fractures and liver function tests, nutritional parameters, or bone mineral density, besides a nearly significant trend (p = .053) with the presence of osteopenia at the femoral neck. Patients with major withdrawal symptoms at admission also presented more frequent rib fractures. We conclude that rib fractures in alcoholics are related to the peculiar lifestyle of these patients rather than to bone alterations, liver dysfunction, or nutritional status.

Cronkhite-Canada syndrome associated with rib fractures: a case report.

PubMed

Yuan, Bosi; Jin, Xinxin; Zhu, Renmin; Zhang, Xiaohua; Liu, Jiong; Wan, Haijun; Lu, Heng; Shen, Yunzhu; Wang, Fangyu

2010-10-18

Cronkhite-Canada syndrome (CCS) is a rare multiple gastrointestinal polyposis. Up till now, many complications of CCS have been reported in the literature, but rib fracture is not included. We report a case of a 58-year-old man who was admitted to our hospital with a 6-month history of frequent diarrhea, intermittent hematochezia and a weight loss of 13 kg. On admission, physical examination revealed alopecia of the scalp, hyperpigmentation of the hands and soles, and dystrophy of the fingernails. Laboratory data revealed hypocalcaemia and hypoproteinemia. Esophagogastroduodenoscopy, video capsule endoscopy and colonoscopy revealed various sizes of generalized gastrointestinal polyps. Histological examination of the biopsy specimens obtained from the stomach and the colon showed adenomatous polyp and inflammatory polyp respectively. Thus, a diagnosis of CCS was made. After treatment with corticosteroids for 24 days and nutritional support for two months, his clinical condition improved. Two months later, he was admitted to our hospital for the second time with frequent diarrhea and weight loss. The chest radiography revealed fractures of the left sixth and seventh ribs. Examinations, including emission computed tomography, bone densitometry test, and other serum parameters, were performed, but could not identify the definite etiology of the rib fractures. One month later, the patient suffered from aggravating multiple rib fractures due to the ineffective treatment, persistent hypocalcaemia and malnutrition. This is the first case of a CCS patient with multiple rib fractures. Although the association between CCS and multiple rib fractures in this case remains uncertain, we presume that persistent hypocalcaemia and malnutrition contribute to this situation, or at least aggravate this rare complication. Besides, since prolonged corticosteroid therapy will result in an increased risk of osteoporotic fracture, CCS patients who accept corticosteroid therapy could be potential victims of rib fracture.

Photonic Waveguide Choke Joint with Absorptive Loading

NASA Technical Reports Server (NTRS)

Wollack, Edward J. (Inventor); U-Yen, Kongpop (Inventor); Chuss, David T. (Inventor)

2016-01-01

A photonic waveguide choke includes a first waveguide flange member having periodic metal tiling pillars, a dissipative dielectric material positioned within an area between the periodic metal tiling pillars and a second waveguide flange member disposed to be coupled with the first waveguide flange member and in spaced-apart relationship separated by a gap. The first waveguide flange member has a substantially smooth surface, and the second waveguide flange member has an array of two-dimensional pillar structures formed therein.

Spondylocostal dysostosis associated with right-sided polythelia, right-sided rib deformity and meningocoele: Case report with review of literature.

PubMed

Rai, Narendra; Thakur, Neha; Khan, Naheed Zin; Dwivedi, Akhilesh Dutt

2015-01-01

Spondylocostal dysostosis (SCD) is a rare anomaly of axial skeleton due to flawed embryological development. A newborn baby boy with right-sided polythelia, meningocoele, fan-like configuration of third and fourth rib, fused fifth and sixth rib and third thoracic hemivertebra was delivered to a second gravid mother by elective caesarean section. Baby was active, cried immediately after birth, had normal muscle tone and reflexes. He passed urine and meconium within 24 h of birth. Based on clinical examination and radiological picture, a diagnosis of SCD with meningocele with right-sided polythelia was made. Our case is the first SCD with polythelia and meningocele in newborn. SCD with right-sided polythelia and rib deformity with neural tube defect (NTD) may be due to a genetic defect with the culprit genes missing. Further genetic and embryological studies might find a link between right-sided rib defects, polythelia and NTD.

Right ventricular rupture after lateral thoracotomy for removal of rib-associated telangiectatic osteosarcoma in a dog.

PubMed

Barmettler, Reto; Spreng, David E; Gorgas, Daniela; Scharf, Gernot; Posthaus, Horst; Sigrist, Nadja E

2009-06-01

To describe a case of a focal right ventricular rupture following removal of a rib-associated telangiectatic osteosarcoma (TOS) in a dog. A 2-year-old spayed female mixed-breed dog, weighing 20 kg, was presented in compensated hypovolemic shock due to active bleeding into the thoracic cavity. The dog was stabilized with appropriate fluid administration. Subsequent computed tomographic examination revealed a large mineralized mass originating from the body of a rib and displacing the heart. Two days after surgical removal of this mass, focal right ventricular rupture occurred and the dog died. The mass was later identified as a TOS. Although hemothorax secondary to TOS has been described previously, this report describes for the first time, spontaneous focal right ventricular rupture as a rare complication of thoracotomy and rib resection for the removal of a rib-associated, intrathoracic TOS.

Flexural strength and behaviour of SFRSCC ribbed slab under four point bending

NASA Astrophysics Data System (ADS)

Ahmad, Hazrina; Hashim, Mohd Hisbany Mohd; Bakar, Afidah Abu; Hamzah, Siti Hawa; Rahman, Fadhillah Abdul

2017-11-01

An experimental investigation was carried out to study the ultimate strength and behaviour of SFRSCC ribbed slab under four point bending. Comparison was been made between ribbed slab that was fully reinforced with steel fibres (SFWS) with conventionally reinforced concrete ribbed slab (CS and CRC). The volume fraction of the 35 mm hooked end steel fibres used in the mix was 1% (80 kg/m3) with the aspect ratio of 65. Three full scale slab samples with the dimension of 2.8 x 1.2 m with 0.2 m thickness was constructed for the purpose of this study. The slab samples was loaded until failure in a four point bending test. As a whole, based on the results, it can be concluded that the performance of the steel fiber reinforced samples (SFWS) was found to be almost equivalent to the conventionally reinforced concrete ribbed slab sample (CRC).

Characteristic scapular and rib changes on chest radiographs of children with ADA-deficiency SCIDS in the first year of life.

PubMed

Manson, David; Diamond, Lauren; Oudjhane, Kamaldine; Hussain, Faisal Bin; Roifman, Chaim; Grunebaum, Eyal

2013-03-01

We describe radiographic changes in the ribs and scapulae seen in the first 6 months of life in children with ADA (adenosine deaminase) deficiency severe combined immundeficiency syndrome (SCIDS). We suggest that these changes are reversible with appropriate enzyme replacement therapy. The purpose of this study was to describe characteristic rib and scapular radiographic changes in infants with ADA-deficiency SCIDS. This was a retrospective review of chest radiographs of nine children with ADA-deficiency SCIDS performed in the first year of life by two experienced pediatric radiologists. A control cohort of unaffected children was used for comparison. All children with ADA-deficiency SCIDS manifested unusual scapular spurring and anterior rib cupping. None of the control children manifested these changes. Characteristic and reversible scapular and rib changes in the correct clinical setting should suggest an early diagnosis of ADA deficiency, prompting appropriate diagnostic and therapeutic measures.

Successful emergency pain control for posterior rib fractures with ultrasound-guided erector spinae plane block.

PubMed

Luftig, Josh; Mantuani, Daniel; Herring, Andrew A; Dixon, Brittany; Clattenburg, Eben; Nagdev, Arun

2017-12-28

The Eastern Association for the Surgery of Trauma and Trauma Anesthesiology Society Guidelines recommend prompt and effective multimodal analgesia for rib fractures that combines regional anesthesia (RA) techniques with pharmacotherapy to treat pain, optimize pulmonary function, and reduce opioid related complications. However, RA techniques such as epidurals and paravertebral blocks, are generally underutilized or unavailable for emergency department (ED) patients. The recently described serratus anterior plane block (SAPB) is a promising technique, but failures with posterior rib fractures have been observed. The erector spinae plane block (ESPB) is conceptually similar to the SAPB, but targets the posterior thorax making it likely more effective for ED patients with posterior rib fractures. Our initial experience demonstrates consistent success with the ESPB for traumatic posterior rib fracture analgesia. Herein, we present the first description of the ESPB utilized in the ED. Copyright © 2017 Elsevier Inc. All rights reserved.

Behavior of streamwise rib vortices in a three-dimensional mixing layer

NASA Technical Reports Server (NTRS)

Lopez, J. M.; Bulbeck, C. J.

1992-01-01

The structure and behavior of a streamwise rib vortex in a direct numerical simulation of a time-developing three-dimensional incompressible plane mixing layer is examined. Where the rib vortex is being stretched, the vorticity vector is primarily directed in the vortex axial direction and the radial and azimuthal velocity distribution is similar to that of a Burger's vortex. In the region where the vortex stretching is negative, there is a change in the local topology of the vortex. The axial flow is decelerated and a negative azimuthal component of vorticity is induced. These features are characteristic of vortex breakdown. The temporal evolution of the rib vortex is similar to the evolution of an axisymmetric vortex in the early stages of vortex breakdown. The effect of vortex breakdown on other parts of the flow is, however, not as significant as the interaction between the rib vortex and other vortices.

Acoustic one-way mode conversion and transmission by sonic crystal waveguides

NASA Astrophysics Data System (ADS)

Ouyang, Shiliang; He, Hailong; He, Zhaojian; Deng, Ke; Zhao, Heping

2016-09-01

We proposed a scheme to achieve one-way acoustic propagation and even-odd mode switching in two mutually perpendicular sonic crystal waveguides connected by a resonant cavity. The even mode in the entrance waveguide is able to switch to the odd mode in the exit waveguide through a symmetry match between the cavity resonant modes and the waveguide modes. Conversely, the odd mode in the exit waveguide is unable to be converted into the even mode in the entrance waveguide as incident waves and eigenmodes are mismatched in their symmetries at the waveguide exit. This one-way mechanism can be applied to design an acoustic diode for acoustic integration devices and can be used as a convertor of the acoustic waveguide modes.

Optical waveguide device with an adiabatically-varying width

DOEpatents

Watts,; Michael R. , Nielson; Gregory, N [Albuquerque, NM

2011-05-10

Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

Adaptive gain, equalization, and wavelength stabilization techniques for silicon photonic microring resonator-based optical receivers

NASA Astrophysics Data System (ADS)

Palermo, Samuel; Chiang, Patrick; Yu, Kunzhi; Bai, Rui; Li, Cheng; Chen, Chin-Hui; Fiorentino, Marco; Beausoleil, Ray; Li, Hao; Shafik, Ayman; Titriku, Alex

2016-03-01

Interconnect architectures based on high-Q silicon photonic microring resonator devices offer a promising solution to address the dramatic increase in datacenter I/O bandwidth demands due to their ability to realize wavelength-division multiplexing (WDM) in a compact and energy efficient manner. However, challenges exist in realizing efficient receivers for these systems due to varying per-channel link budgets, sensitivity requirements, and ring resonance wavelength shifts. This paper reports on adaptive optical receiver design techniques which address these issues and have been demonstrated in two hybrid-integrated prototypes based on microring drop filters and waveguide photodetectors implemented in a 130nm SOI process and high-speed optical front-ends designed in 65nm CMOS. A 10Gb/s powerscalable architecture employs supply voltage scaling of a three inverter-stage transimpedance amplifier (TIA) that is adapted with an eye-monitor control loop to yield the necessary sensitivity for a given channel. As reduction of TIA input-referred noise is more critical at higher data rates, a 25Gb/s design utilizes a large input-stage feedback resistor TIA cascaded with a continuous-time linear equalizer (CTLE) that compensates for the increased input pole. When tested with a waveguide Ge PD with 0.45A/W responsivity, this topology achieves 25Gb/s operation with -8.2dBm sensitivity at a BER=10-12. In order to address microring drop filters sensitivity to fabrication tolerances and thermal variations, efficient wavelength-stabilization control loops are necessary. A peak-power-based monitoring loop which locks the drop filter to the input wavelength, while achieving compatibility with the high-speed TIA offset-correction feedback loop is implemented with a 0.7nm tuning range at 43μW/GHz efficiency.

Photonic crystal slab waveguides in moderate index contrast media: Generalized transverse Bragg waveguides

NASA Astrophysics Data System (ADS)

Burckel, David Bruce

One of the anticipated advantages of photonic crystal waveguides is the ability to tune waveguide dispersion and propagation characteristics to achieve desired properties. The majority of research into photonic crystal waveguides centers around high index contrast photonic crystal waveguides with complete in-plane bandgaps in the photonic crystal cladding. This work focuses on linear photonic crystal waveguides in moderate index materials, with insufficient index contrast to guarantee a complete in-plane bandgap. Using a technique called Interferometric Lithography (IL) as well as standard semiconductor processing steps, a process flow for creating large area (˜cm 2), linear photonic crystal waveguides in a spin-deposited photocurable polymer is outlined. The study of such low index contrast photonic crystal waveguides offers a unique opportunity to explore the mechanisms governing waveguide confinement and photonic crystal behavior in general. Results from two optical characterization experiments are provided. In the first set of experiments, rhodamine 590 organic laser dye was incorporated into the polymer prior to fabrication of the photonic crystal slab. Emission spectra from waveguide core modes exhibit no obvious spectral selectivity owing to variation in the periodicity or geometry of the photonic crystal. In addition, grating coupled waveguides were fabricated, and a single frequency diode laser was coupled into the waveguide in order to study the transverse mode structure. To this author's knowledge, the optical mode profile images are the first taken of photonic crystal slab waveguides, exhibiting both simple low order mode structure as well as complex high order mode structure inconsistent with effective index theory. However, no obvious correlation between the mode structure and photonic crystal period or geometry was evident. Furthermore, in both the laser dye-doped and grating coupled waveguides, low loss waveguiding was observed regardless of wavelength to period ratio. These optical results indicated a need for a deeper understanding of the confinement/guiding mechanisms in such waveguide structures. A simplification of the full 2-D problem to a more tractable "tilted 1-D" geometry led to the proposal of a new waveguide geometry, Generalized Transverse Bragg Waveguides (GTBW), as well as a new propagation mode characterized by spatial variation in both the transverse direction as well as the direction of propagation. GTBW demonstrate many of the same dispersion tunability traits exhibited in complete bandgap photonic crystal waveguides, under more modest fabrication demands, and moreover provide much insight into photonic crystal waveguide modes of all types. Generalized Transverse Bragg Waveguides are presented in terms of the standard physical properties associated with waveguides, including the dispersion relation, expressions for the spatial field profile, and the concepts of phase and group velocity. In addition, the proposal of at least one obvious application, semiconductor optical amplifiers, is offered.

An unusual cause of rib fracture following a road traffic accident.

PubMed Central

Daniels, R J; Fulcher, R A

1997-01-01

A case is presented which is thought to be the first described example of rib fracture occurring as a result of airbag inflation. It would appear that the propellant cartridge came loose during deployment to form a missile, striking the patient on his chest and fracturing a rib. Images Figure 1 Figure 2 Figure 3 PMID:9132187

Replacing conventional or brown-mid rib corn silage with brown-mid rib sudangrass silage in the diets of lactating dairy cows

USDA-ARS?s Scientific Manuscript database

Forages that use less water, but are high in digestibility, are sought as alternatives to traditional forages such as corn silage. Brown mid-rib (BMR) sudangrass is a possible alternative that can provide high-quality forage as a replacement for corn silage. The objective of this study was to evalua...

Rib Fracture Fixation: Indications and Outcomes.

PubMed

Senekjian, Lara; Nirula, Raminder

2017-01-01

Rib fractures are a frequently identified injury in the trauma population. Not only are multiple rib fractures painful, but they are associated with an increased risk of adverse outcomes. Pneumonia in particular can be devastating, especially to an elderly patient, but other complications such as prolonged ventilation and increased intensive care and hospital durations of stay have a negative impact on the patient. Computed tomography scan is the best modality to diagnosis rib fractures but the treatment of fractures is still evolving. Currently patient care involves a multidisciplinary approach that includes pain control, aggressive pulmonary therapy, and possibly surgical fixation. Copyright © 2016 Elsevier Inc. All rights reserved.

Reoperative surgical stabilization of a painful nonunited rib fracture using bone grafting and a metal plate.

PubMed

Cho, Yang Hyun; Kim, Hyun Koo; Kang, Du-Young; Choi, Young Ho

2009-09-01

We report a case of a nonunited sixth rib in a patient with multiple rib fractures who underwent internal fixation using a wire and Judet strut 3 times. During the following 3 years, the patient continued to complain of pain and instability. At surgery, a pseudarthrosis between the ends of the sixth rib was excised. A longitudinal gutter crossing the fracture site was fashioned and splinted with an inlay block of cancellous bone grafted from the iliac crest; stabilization was accomplished with a reconstruction plate and screws. The following 2 years of follow-up demonstrated no instability or pain.

Thoracoscopic resection of parosteal lipoma of the rib using orthopedic electric micro drill.

PubMed

Go, Tetsuhiko; Nakajima, Nariyasu; Yokota, Naoya; Yokomise, Hiroyasu

2018-05-09

Parosteal lipoma derived from the rib is extremely rare and is usually resected through open thoracotomy despite its benign nature. A 33-year-old man who had no symptoms was referred to our hospital for treatment of a 30-mm chest wall mass that has slightly increased in size during 2 years of follow-up. En bloc resection of the tumor with parts of the 3rd and 4th ribs was performed through a complete thoracoscopic approach using orthopedic electric micro drill. This was the first report on a case of parosteal lipoma of the rib that was resected by a complete thoracoscopic procedure.

Rib Geometry Explains Variation in Dynamic Structural Response: Potential Implications for Frontal Impact Fracture Risk.

PubMed

Murach, Michelle M; Kang, Yun-Seok; Goldman, Samuel D; Schafman, Michelle A; Schlecht, Stephen H; Moorhouse, Kevin; Bolte, John H; Agnew, Amanda M

2017-09-01

The human thorax is commonly injured in motor vehicle crashes, and despite advancements in occupant safety rib fractures are highly prevalent. The objective of this study was to quantify the ability of gross and cross-sectional geometry, separately and in combination, to explain variation of human rib structural properties. One hundred and twenty-two whole mid-level ribs from 76 fresh post-mortem human subjects were tested in a dynamic frontal impact scenario. Structural properties (peak force and stiffness) were successfully predicted (p < 0.001) by rib cross-sectional geometry obtained via direct histological imaging (total area, cortical area, and section modulus) and were improved further when utilizing a combination of cross-sectional and gross geometry (robusticity, whole bone strength index). Additionally, preliminary application of a novel, adaptive thresholding technique, allowed for total area and robusticity to be measured on a subsample of standard clinical CT scans with varied success. These results can be used to understand variation in individual rib response to frontal loading as well as identify important geometric parameters, which could ultimately improve injury criteria as well as the biofidelity of anthropomorphic test devices (ATDs) and finite element (FE) models of the human thorax.

Generation of Turbulent Inflow Conditions for Pipe Flow via an Annular Ribbed Turbulator

NASA Astrophysics Data System (ADS)

Moallemi, Nima; Brinkerhoff, Joshua

2016-11-01

The generation of turbulent inflow conditions adds significant computational expense to direct numerical simulations (DNS) of turbulent pipe flows. Typical approaches involve introducing boxes of isotropic turbulence to the velocity field at the inlet of the pipe. In the present study, an alternative method is proposed that incurs a lower computational cost and allows the anisotropy observed in pipe turbulence to be physically captured. The method is based on a periodic DNS of a ribbed turbulator upstream of the inlet boundary of the pipe. The Reynolds number based on the bulk velocity and pipe diameter is 5300 and the blockage ratio (BR) is 0.06 based on the rib height and pipe diameter. The pitch ratio is defined as the ratio of rib streamwise spacing to rib height and is varied between 1.7 and 5.0. The generation of turbulent flow structures downstream of the ribbed turbulator are identified and discussed. Suitability of this method for accurate representation of turbulent inflow conditions is assessed through comparison of the turbulent mean properties, fluctuations, Reynolds stress profiles, and spectra with published pipe flow DNS studies. The DNS results achieve excellent agreement with the numerical and experimental data available in the literature.

Transcostal high-intensity focused ultrasound treatment using phased array with geometric correction.

PubMed

Qiao, Shan; Shen, Guofeng; Bai, Jingfeng; Chen, Yazhu

2013-08-01

In the high-intensity focused ultrasound treatment of liver tumors, ultrasound propagation is affected by the rib cage. Because of the diffraction and absorption of the bone, the sound distribution at the focal plane is altered, and more importantly, overheating on the rib surface might occur. To overcome these problems, a geometric correction method is applied to turn off the elements blocked by the ribs. The potential of steering the focus of the phased-array along the propagation direction to improve the transcostal treatment was investigated by simulations and experiments using different rib models and transducers. The ultrasound propagation through the ribs was computed by a hybrid method including the Rayleigh-Sommerfeld integral, k-space method, and angular spectrum method. A modified correction method was proposed to adjust the output of elements based on their relative area in the projected "shadow" of the ribs. The simulation results showed that an increase in the specific absorption rate gain up to 300% was obtained by varying the focal length although the optimal value varied in each situation. Therefore, acoustic simulation is required for each clinical case to determine a satisfactory treatment plan.

Numerical analysis of installation damage of a pre-damaged geogrid with rectangular apertures

NASA Astrophysics Data System (ADS)

Dong, Yan-li; Guo, Hui-juan; Han, Jie; Zhang, Jun

2018-06-01

The geogrid can be damaged in the process or during construction if sufficient care is not exercised. In this study, the numerical software-FLAC was adopted to investigate the responses of pre-damaged geogrids with rectangular apertures when subjected to a uniaxial tensile load at different directions relative to the orientations of ribs in air. To simulate the combined loss of ribs and junction strength, specimens were pre-damaged by reducing certain amount of stiffness of the geogrid ribs. The geogrid ribs were modeled using beam elements jointed rigidly at nodes and subjected to tension in one direction. The numerical study demonstrated that the pre-damaged geogrid with rectangular apertures had similar responses when it was subjected to tension at the loading directions. The pre-damaged geogrids under 30° tension are the most sensitivity to the damage. With the increase of the degree of damage, the tensile strengths decreased relative quickly. An increase of the degree of installation damage of ribs decreased the tensile strength/stiffness of the geogrid with rectangular apertures. A higher reduction factor RFID due to installation damage is suggested when the geogrid is subjected to 30° tension relative to the orientation of ribs.

In Situ Splitting of a Rib Bone Graft for Reconstruction of Orbital Floor and Medial Wall.

PubMed

Uemura, Tetsuji; Yanai, Tetsu; Yasuta, Masato; Harada, Yoshimi; Morikawa, Aya; Watanabe, Hidetaka; Kurokawa, Masato

2017-06-01

In situ splitting of rib bone graft was conducted in 22 patients for the repair of orbital fracture with no other complicating fractures. A bone graft was harvested from the sixth or seventh rib in the right side. The repair of the orbital floor and medial wall was successful in all the cases. Ten patients had bone grafting to the orbital floor, eight had it done onto medial wall, and 4 onto both floor and wall after reduction. The mean length of in situ rib bone graft was 40.9 mm (range, 20-70 mm), the mean width of these was 14.9 mm (range, 8-20 mm). The bone grafting was done by one leaf for 15 cases and two leafs for 7 cases in size of defects. The technique of in situ splitting of a rib bone graft for the repair of the orbital floor and medial wall is a simple and safe procedure, easily taking out the in situ splitting of a rib, and less pain in donor site. It has proved to be an optimal choice in craniofacial reconstruction, especially the defects of orbital floor and medial wall.

Flank pseudohernia following posterior rib fracture: a case report.

PubMed

Butensky, Adam M; Gruss, Leah P; Gleit, Zachary L

2016-10-01

A pseudohernia is an abdominal wall bulge that may be mistaken for a hernia but that lacks the disruption of the abdominal wall that characterizes a hernia. Thus, the natural history and treatment of this condition differ from those of a hernia. This is the first report of a pseudohernia due to cough-associated rib fracture. A case of pseudohernia due to fractures of the 10 th and 11 th ribs in a 68-year-old white woman is presented. The patient suffered from a major coughing episode 1 year prior to her presentation, after which she noted a progressively enlarging bulge in her left flank. Computed tomography demonstrated a bulge in the abdominal wall containing bowel and spleen but with all muscle and fascial layers intact; in addition, lateral 10 th rib and posterior 11 th rib fractures were noted. As there was no defect in muscle or fascia, we diagnosed a pseudohernia, likely due to a denervation injury from the fractured ribs. Symptomatic treatment was recommended, including wearing a corset and referral to a pain management clinic. Symptomatic treatment is thought to be the mainstay of therapy for pseudohernias, as surgical intervention is unlikely to be of benefit.

First-rib stress fracture in two adolescent swimmers: a case report.

PubMed

Low, Sara; Kern, Michael; Atanda, Alfred

2016-01-01

First-rib stress fractures have been described in adolescent athletes in various sports, with only one prior case report of first-rib stress fractures in an adolescent female swimmer. There is a need for research on the cause, management, and prevention of these injuries as they lead to significant morbidity and critical time away from sport for these aspiring athletes. We aimed to describe first-rib stress fractures as a potential cause for non-specific atraumatic chronic shoulder pain in adolescent swimmers and to discuss the different presentations, unique risk factors, treatment, and potential injury prevention strategies of such fractures. We discussed two such cases which were successfully treated with activity modification with restriction of all overhead activity, gradually progressive physical therapy and a return to swimming protocol. First-rib stress fractures can vary in presentation and should be in the differential diagnosis in adolescent swimmers with chronic shoulder pain. These injuries can be successfully managed with rest from overhead activities and physical therapy. Gradual return to competitive swimming can be achieved even with non-union of a first-rib stress fracture. Emphasis on balanced strength training in different muscle groups and proper swimming technique is essential to prevent these injuries.

Rib Geometry Explains Variation in Dynamic Structural Response: Potential Implications for Frontal Impact Fracture Risk

PubMed Central

Murach, Michelle M.; Kang, Yun-Seok; Goldman, Samuel D.; Schafman, Michelle A.; Schlecht, Stephen H.; Moorhouse, Kevin; Bolte, John H.; Agnew, Amanda M.

2018-01-01

The human thorax is commonly injured in motor vehicle crashes, and despite advancements in occupant safety rib fractures are highly prevalent. The objective of this study was to quantify the ability of gross and cross-sectional geometry, separately and in combination, to explain variation of human rib structural properties. One hundred and twenty-two whole mid-level ribs from 76 fresh post-mortem human subjects were tested in a dynamic frontal impact scenario. Structural properties (peak force and stiffness) were successfully predicted (p<0.001) by rib cross-sectional geometry obtained via direct histological imaging (total area, cortical area, and section modulus) and were improved further when utilizing a combination of cross-sectional and gross geometry (robusticity, whole bone strength index). Additionally, preliminary application of a novel, adaptive thresholding technique, allowed for total area and robusticity to be measured on a subsample of standard clinical CT scans with varied success. These results can be used to understand variation in individual rib response to frontal loading as well as identify important geometric parameters, which could ultimately improve injury criteria as well as the biofidelity of anthropomorphic test devices (ATDs) and finite element (FE) models of the human thorax. PMID:28547660

Chondro-manubrial deformity and bifid rib, rare variations seen in pectus carinatum: a radiological finding.

PubMed

Allwyn Joshua, S; Shetty, Lathika; Pare, V S; Sebastian, Roopa

2013-07-01

Pectus carinatum or protrusion deformity of chest wall is less frequently occurring anterior chest wall deformity when compared to pectus excavatum. It may be classified as type 1 or chondro-gladiolar and type 2 or chondro-manubrial deformity. Other variations seen are symmetrical and asymmetrical pectus carinatum. Here we present two unique case reports, one with chondro-manubrial deformity (Currarino-Silverman syndrome) and other with asymmetrical pectus carinatum having bifid rib which are some of the rare variations seen in pectus carinatum found during Computerized tomographic examination. Currarino-Silverman syndrome is a type 2 pectus carinatum, a rare deformity with chondro-manubrial involvement and usually associated congenital heart diseases. Early fusion of sternal plates is one of the known theories in producing this deformity. On the other hand, asymmetrical pectus deformity are usually seen due to imbalance or abnormality in growth plates of costal cartilages leading to forked rib or bifid rib, which are accidently seen on radiological examination. To conclude, our reports would help in differential diagnosis from frequently occurring conditions affecting chest like chondro-gladiolar deformity, pectus excavatum, chest wall tumours, rib fractures and intra thoracic ribs.

Estimation of carcass composition using rib dissection of calf-fed Holstein steers supplemented zilpaterol hydrochloride.

PubMed

McEvers, T J; May, N D; Reed, J A; Walter, L J; Hutcheson, J P; Lawrence, T E

2018-04-14

A serial harvest was conducted every 28 d from 254 to 534 d on feed (DOF) to quantify changes in growth and composition of calf-fed Holstein steers (n = 115, initial body weight (BW) = 449.2 ± 19.9 kg). One-half were supplemented with the β-2 adrenergic agonist zilpaterol hydrochloride (ZH; 8.33 mg/kg 100% dry matter (DM) basis) during the final 20 d followed by a 3-d withdrawal prior to harvest; the remainder was fed a non-ZH control (CON) ration. Five steers were randomly selected and harvested after 226 DOF which served as a reference point for modeling purposes. Fabricated carcass soft tissue was ground, mixed, and subsampled for proximate analysis. Moreover, following the traditional method of rib dissection which includes the 9th, 10th, and 11th rib contained within the IMPS 103 primal, the relationship of carcass chemical composition to 9-10-11 rib composition was evaluated. Carcasses in this investigation had more (P < 0.01) separable lean, fat, ash, and moisture concomitant with less bone and ether extract than rib dissections. However, protein levels were similar (P = 0.27) between carcasses and rib dissections. Using regression procedures, models were constructed to describe the relationship of rib dissection (RD) composition including separable lean (RDSL), separable fat (RDSF), separable bone (RDSB), ether extract (RDEE), protein (RDP), moisture (RDM), and ash (RDA) with carcass composition. Carcass lean (CL), carcass fat (CF), and carcass bone (CB) were correlated (P < 0.01) with RDSL, RDSF, and RDSB with simple r values of 0.41, 0.71, and 0.50, respectively. Chemical composition of the rib and carcass, carcass ether extract (CEE), carcass protein (CP), carcass moisture (CM), and carcass ash (CA) were correlated (P ≤ 0.01) with simple r values of 0.75, 0.31, 0.66, and 0.37, respectively. Equations to predict carcass fatness from rib dissection variables and ZH supplementation status were only able to account for 50 and 56%, of the variability of CF and CEE, respectively. Overall, the relationships quantified and equations developed in this investigation do not support use of 9/10/11 rib dissection for estimation of carcass composition of calf-fed Holstein steers.

Integration of a waveguide self-electrooptic effect device and a vertically coupled interconnect waveguide

DOEpatents

Vawter, G Allen [Corrales, NM

2008-02-26

A self-electrooptic effect device ("SEED") is integrated with waveguide interconnects through the use of vertical directional couplers. Light initially propagating in the interconnect waveguide is vertically coupled to the active waveguide layer of the SEED and, if the SEED is in the transparent state, the light is coupled back to the interconnect waveguide.

Simplified flangeless unisex waveguide coupler assembly

DOEpatents

Michelangelo, Dimartino; Moeller, Charles P.

1993-01-01

A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150.degree. C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. The split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide. The second collar is then slipped over the second waveguide behind the annular groove and retaining ring therein and the second collar is coaxially secured by fastening means to the split collar to draw the respective waveguides together by coaxial force exerted by the second collar against the retaining ring on the second waveguide. A sealing ring is placed against an external sealing surface at a reduced external diameter end formed on one waveguide to sealingly engage a corresponding sealing surface on the other waveguide as the waveguides are urged toward each other.

Simplified flangeless unisex waveguide coupler assembly

DOEpatents

Michelangelo, D.; Moeller, C.P.

1993-05-04

A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150 C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. The split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide. The second collar is then slipped over the second waveguide behind the annular groove and retaining ring therein and the second collar is coaxially secured by fastening means to the split collar to draw the respective waveguides together by coaxial force exerted by the second collar against the retaining ring on the second waveguide. A sealing ring is placed against an external sealing surface at a reduced external diameter end formed on one waveguide to sealingly engage a corresponding sealing surface on the other waveguide as the waveguides are urged toward each other.

Simplified flangeless unisex waveguide coupler assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michelangelo, D.; Moeller, C.P.

1993-05-04

A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150 C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. Themore » split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide. The second collar is then slipped over the second waveguide behind the annular groove and retaining ring therein and the second collar is coaxially secured by fastening means to the split collar to draw the respective waveguides together by coaxial force exerted by the second collar against the retaining ring on the second waveguide. A sealing ring is placed against an external sealing surface at a reduced external diameter end formed on one waveguide to sealingly engage a corresponding sealing surface on the other waveguide as the waveguides are urged toward each other.« less

Design of organic 3D microresonators with microfluidics coupled to thin-film processes for photonic applications

NASA Astrophysics Data System (ADS)

Huby, N.; Pluchon, D.; Coulon, N.; Belloul, M.; Moreac, A.; Gaviot, E.; Panizza, P.; Bêche, B.

2010-06-01

We report on the design and realization of photonic integrated devices based on 3D organic microresonators (MR) shaped by an applied fluid mechanism technique. Such an interdisciplinary approach has been judiciously achieved by combining microfluidics techniques and thin-film processes, respectively, for the realizations of microfluidic and optical chips. The microfluidic framework with flow rates control allows the fabrication of microresonators with diameters ranging from 30 to 160 μm. The resonance of an isolated sphere in air has been demonstrated by way of a modified Raman spectroscopy devoted to the excitation of Whispering Gallery Modes (WGM). Then the 3D-MR have been integrated onto an organic chip and positioned either close to the extremity of a taper or alongside a rib waveguide. Both devices have proved efficient evanescent coupling mechanisms leading to the excitation of the WGM confined at the surface of the organic 3D-MR. Finally, a band-stop filter has been used to detect the resonance spectra of organic resonators once being integrated. Such spectral resonances have been observed with an integrated configuration and characterized with a Δ λ = 1.4 nm free spectral range (FSR), appearing as stemming from a 78 μm-radius MR structure.

Ultra-Compact Ka-Band Parabolic Deployable Antenna for RADAR and Interplanetary CubeSats

NASA Technical Reports Server (NTRS)

Sauder, Jonathan; Chahat, Nacer; Thomson, Mark; Hodges, Richard; Peral, Eva; Rahmat-Samii, Yahya

2015-01-01

Over the past several years, technology and launch opportunities for CubeSats have exploded, enabling a wide variety of missions. However, as instruments become more complex and CubeSats travel deeper into space, data communication rates become an issue. To solve this challenge, JPL has initiated a research and technology development effort to design a 0.5 meter Ka-band parabolic deployable antenna (KaPDA) which would stow in 1.5U (10 x 10 x 15 cu cm) and provide 42dB of gain (50% efficiency). A folding rib architecture and dual reflector Cassegrainian design was selected as it best balances RF gain and stowed size. The design implements an innovative telescoping waveguide and gas powered deployment. RF simulations show that after losses, the antenna would have over 42 dB gain, supported by preliminary test results. KaPDA would create opportunities for a host of new CubeSat missions by allowing high data rate communication which would enable using high fidelity instruments or venturing further into deep space, including potential interplanetary missions. Additionally KaPDA would provide a solution for other small antenna needs and the opportunity to obtain Earth science data. This paper discusses the design challenges encountered, the architecture of the solution, and the antennas expected performance capabilities.

Analysis of the rectangular resonator with butterfly MMI coupler using SOI

NASA Astrophysics Data System (ADS)

Kim, Sun-Ho; Park, Jun-Hee; Kim, Eudum; Jeon, Su-Jin; Kim, Ji-Hoon; Choi, Young-Wan

2018-02-01

We propose a rectangular resonator sensor structure with butterfly MMI coupler using SOI. It consists of the rectangular resonator, total internal reflection (TIR) mirror, and the butterfly MMI coupler. The rectangular resonator is expected to be used as bio and chemical sensors because of the advantages of using MMI coupler and the absence of bending loss unlike ring resonators. The butterfly MMI coupler can miniaturize the device compared to conventional MMI by using a linear butterfly shape instead of a square in the MMI part. The width, height, and slab height of the rib type waveguide are designed to be 1.5 μm, 1.5 μm, and 0.9 μm, respectively. This structure is designed as a single mode. When designing a TIR mirror, we considered the Goos-Hänchen shift and critical angle. We designed 3:1 MMI coupler because rectangular resonator has no bending loss. The width of MMI is designed to be 4.5 μm and we optimize the length of the butterfly MMI coupler using finite-difference time-domain (FDTD) method for higher Q-factor. It has the equal performance with conventional MMI even though the length is reduced by 1/3. As a result of the simulation, Qfactor of rectangular resonator can be obtained as 7381.

Design optimization of a compact photonic crystal microcavity based on slow light and dispersion engineering for the miniaturization of integrated mode-locked lasers

NASA Astrophysics Data System (ADS)

Kemiche, Malik; Lhuillier, Jérémy; Callard, Ségolène; Monat, Christelle

2018-01-01

We exploit slow light (high ng) modes in planar photonic crystals in order to design a compact cavity, which provides an attractive path towards the miniaturization of near-infrared integrated fast pulsed lasers. By applying dispersion engineering techniques, we can design structures with a low dispersion, as needed by mode-locking operation. Our basic InP SiO2 heterostructure is robust and well suited to integrated laser applications. We show that an optimized 30 μm long cavity design yields 9 frequency-equidistant modes with a FSR of 178 GHz within a 11.5 nm bandwidth, which could potentially sustain the generation of optical pulses shorter than 700 fs. In addition, the numerically calculated quality factors of these modes are all above 10,000, making them suitable for reaching laser operation. Thanks to the use of a high group index (28), this cavity design is almost one order of magnitude shorter than standard rib-waveguide based mode-locked lasers. The use of slow light modes in planar photonic crystal based cavities thus relaxes the usual constraints that tightly link the device size and the quality (peak power, repetition rate) of the pulsed laser signal.

Rib Bone Graft Adjusted to Fit the Facial Asymmetry: A Frame Structure Graft.

PubMed

Lee, Yoon Ho; Choi, Jong Hwan; Hwang, Kun; Choi, Jun Ho

2015-10-01

The authors introduce the concept of a "frame structure graft" in which a harvested rib bone was adjusted to fit facial asymmetry. On the costochondral junction of the sixth or seventh rib, a 5 cm incision was made. Through a subperiosteal dissection, the rib bone was harvested. Using a reciprocating saw, the harvested rib was scored on its anterior surface as well as its posterior surface with a partial depth at different intervals. The harvested rib bone was placed on the skin surface of the unaffected side of the face and a curvature was created exactly matching that of the unaffected side by bending the bone using a greenstick fracture. Thereafter, the graft was adjusted to conceal the asymmetry of the deficient side. The adjusted "frame structure" was transferred to the defect through the incisions on the affected side, and the "frame structure" graft was placed on the mandible or zygoma. The graft fixation was done externally with at least 2 Kirschner wires (K-wires). From January 2005 to August 2013, a total of 30 patients (13 men, 17 women, mean age 25.6 years) received a frame structure graft. All 30 patients achieved good healing at the operation site without complications. Donor-site morbidity as pneumothorax from the rib bone harvest was not found. Merits of this frame structure graft, the authors think, are that this method could allow a similar curvature to the normal side. In addition, the procedure itself is easy.

Rib fracture after stereotactic radiotherapy on follow-up thin-section computed tomography in 177 primary lung cancer patients

PubMed Central

2011-01-01

Background Chest wall injury after stereotactic radiotherapy (SRT) for primary lung cancer has recently been reported. However, its detailed imaging findings are not clarified. So this study aimed to fully characterize the findings on computed tomography (CT), appearance time and frequency of chest wall injury after stereotactic radiotherapy (SRT) for primary lung cancer Materials and methods A total of 177 patients who had undergone SRT were prospectively evaluated for periodical follow-up thin-section CT with special attention to chest wall injury. The time at which CT findings of chest wall injury appeared was assessed. Related clinical symptoms were also evaluated. Results Rib fracture was identified on follow-up CT in 41 patients (23.2%). Rib fractures appeared at a mean of 21.2 months after the completion of SRT (range, 4 -58 months). Chest wall edema, thinning of the cortex and osteosclerosis were findings frequently associated with, and tending to precede rib fractures. No patients with rib fracture showed tumors > 16 mm from the adjacent chest wall. Chest wall pain was seen in 18 of 177 patients (10.2%), of whom 14 patients developed rib fracture. No patients complained of Grade 3 or more symptoms. Conclusion Rib fracture is frequently seen after SRT for lung cancer on CT, and is often associated with chest wall edema, thinning of the cortex and osteosclerosis. However, related chest wall pain is less frequent and is generally mild if present. PMID:21995807

Feasibility of emergency department point-of-care ultrasound for rib fracture diagnosis in minor thoracic injury.

PubMed

Lalande, Élizabeth; Guimont, Chantal; Émond, Marcel; Parent, Marc Charles; Topping, Claude; Kuimi, Brice Lionel Batomen; Boucher, Valérie; Le Sage, Natalie

2017-05-01

The main objective of this study was to evaluate the feasibility of emergency department (ED) point-of-care ultrasound (PoCUS) for rib fracture diagnosis in patients with minor thoracic injury (mTI). Secondary objectives were to 1) evaluate patients' pain during the PoCUS procedure, 2) identify the limitations of the use of PoCUS technique, and 3) compare the diagnosis obtained with PoCUS to radiography results. Adult patients who presented with clinical suspicion of rib fractures after mTI were included. All patients underwent PoCUS performed by emergency physicians (EPs) prior to a rib view X-ray. A visual analogue scale (VAS) ranging from 0 to 100 was used to ascertain feasibility, patients' pain and clinicians' degree of certitude. Feasibility was defined as a score of more than 50 on the VAS. We documented the radiologists' interpretation of rib view X-ray. Radiologists were blinded to the PoCUS results. Ninety-six patients were included. A majority (65%) of EPs concluded that the PoCUS technique to diagnose rib fracture was feasible (VAS score > 50). Median score for feasibility was 63. Median score was 31 (Interquartile range [IQR] 5-57) for patients' pain related to the PoCUS. The main limiting factor of the PoCUS technique was pain during patient examination (15%). PoCUS examination appears to be a feasible technique for a rib fracture diagnosis in the ED.

Evanescent fields of laser written waveguides

NASA Astrophysics Data System (ADS)

Jukić, Dario; Pohl, Thomas; Götte, Jörg B.

2015-03-01

We investigate the evanescent field at the surface of laser written waveguides. The waveguides are written by a direct femtosecond laser writing process into fused silica, which is then sanded down to expose the guiding layer. These waveguides support eigenmodes which have an evanescent field reaching into the vacuum above the waveguide. We study the governing wave equations and present solution for the fundamental eigenmodes of the modified waveguides.

Vertical waveguides integrated with silicon photodetectors: Towards high efficiency and low cross-talk image sensors

NASA Astrophysics Data System (ADS)

Tut, Turgut; Dan, Yaping; Duane, Peter; Yu, Young; Wober, Munib; Crozier, Kenneth B.

2012-01-01

We describe the experimental realization of vertical silicon nitride waveguides integrated with silicon photodetectors. The waveguides are embedded in a silicon dioxide layer. Scanning photocurrent microscopy is performed on a device containing a waveguide, and on a device containing the silicon dioxide layer, but without the waveguide. The results confirm the waveguide's ability to guide light onto the photodetector with high efficiency. We anticipate that the use of these structures in image sensors, with one waveguide per pixel, would greatly improve efficiency and significantly reduce inter-pixel crosstalk.

Microoptoelectromechanical system (MOEMS) based laser

DOEpatents

Hutchinson, Donald P.

2003-11-04

A method for forming a folded laser and associated laser device includes providing a waveguide substrate, micromachining the waveguide substrate to form a folded waveguide structure including a plurality of intersecting folded waveguide paths, forming a single fold mirror having a plurality of facets which bound all ends of said waveguide paths except those reserved for resonator mirrors, and disposing a pair of resonator mirrors on opposite sides of the waveguide to form a lasing cavity. A lasing material is provided in the lasing cavity. The laser can be sealed by disposing a top on the waveguide substrate. The laser can include a re-entrant cavity, where the waveguide substrate is disposed therein, the re-entrant cavity including the single fold mirror.

Femtosecond laser inscribed cladding waveguide lasers in Nd:LiYF4 crystals

NASA Astrophysics Data System (ADS)

Li, Shi-Ling; Huang, Ze-Ping; Ye, Yong-Kai; Wang, Hai-Long

2018-06-01

Depressed circular cladding, buried waveguides were fabricated in Nd:LiYF4 crystals with an ultrafast Yb-doped fiber master-oscillator power amplifier laser. Waveguides were optimized by varying the laser writing conditions, such as pulse energy, focus depth, femtosecond laser polarization and scanning velocity. Under optical pump at 799 nm, cladding waveguides showed continuous-wave laser oscillation at 1047 nm. Single- and multi-transverse modes waveguide laser were realized by varying the waveguide diameter. The maximum output power in the 40 μm waveguide is ∼195 mW with a slope efficiency of 34.3%. The waveguide lasers with hexagonal and cubic cladding geometry were also realized.

Electrically Tunable Nd:YAG waveguide laser based on Graphene

PubMed Central

Ma, Linan; Tan, Yang; Akhmadaliev, Shavkat; Zhou, Shengqiang; Chen, Feng

2016-01-01

We demonstrate a tunable hybrid Graphene-Nd:YAG cladding waveguide laser exploiting the electro-optic and the Joule heating effects of Graphene. A cladding Nd:YAG waveguide was fabricated by the ion irradiation. The multi-layer graphene were transferred onto the waveguide surface as the saturable absorber to get the Q-switched pulsed laser oscillation in the waveguide. Composing with appropriate electrodes, graphene based capacitance and heater were formed on the surface of the Nd:YAG waveguide. Through electrical control of graphene, the state of the hybrid waveguide laser was turned on or off. And the laser operation of the hybrid waveguide was electrically tuned between the continuous wave laser and the nanosecond pulsed laser. PMID:27833114

Design of a low-frequency (5-20 GHz), 15-meter-diameter passive radiometer for geostationary earth science platforms

NASA Technical Reports Server (NTRS)

Sinha, A. K.

1989-01-01

The Wrap-Rib Antenna is a deployable lightweight shaped reflector. It consists of a central hub, parabolic ribs, and an rf reflector mesh. The wrap-rib reflector approximates the desired surface by means of pie-shaped segments of parabolic cylinders. The elements of the total system and the feasibility of the system are discussed.

Effect of Wagyu- versus Angus-sired calves on feedlot performance, carcass characteristics, and tenderness.

PubMed

Radunz, A E; Loerch, S C; Lowe, G D; Fluharty, F L; Zerby, H N

2009-09-01

Wagyu-sired (n = 20) and Angus-sired (n = 19) steers and heifers were used to compare the effects of sire breed on feedlot performance, carcass characteristics, and meat tenderness. Calves were weaned at 138 +/- 5 d of age and individually fed a finishing diet consisting of 65% whole corn, 20% protein/vitamin/mineral supplement, and 15% corn silage on a DM basis. Heifers and steers were slaughtered at 535 and 560 kg of BW, respectively. Carcasses were ribbed between the 12th and 13th (USDA grading system) and the 6th and 7th ribs (Japanese grading system) to measure fat thickness, LM area (LMA), and intramuscular fat (IMF). Two steaks were removed from the 12th rib location and aged for 72 h and 14 d to determine Warner-Bratzler shear force and cooking loss. Sire breed x sex interactions were not significant (P > 0.05). Angus-sired calves had greater (P < 0.05) ADG and DMI than Wagyu. Wagyu-sired calves had improved (P < 0.05) feed efficiency than Angus. Sire breed did not affect (P > 0.20) HCW, 12th-rib fat, or USDA yield grade. Carcasses of Wagyu had greater (P = 0.0001) marbling scores at the 12th rib than those of Angus (770.9 vs. 597.3 +/- 41.01, respectively). Carcasses of Wagyu also had greater (P < 0.02) 12th-rib IMF and 6th-rib IMF than Angus, resulting in a greater proportion of carcasses grading Prime (65.0 vs. 21.1%; P = 0.006). Carcasses from Wagyu tended (P = 0.08) to have greater LMA at the 12th rib, whereas Angus carcasses had greater (P < 0.05) LMA at the 6th rib. Steaks from Angus and Wagyu had similar (P > 0.50) tenderness at aging times of 72 h and 14 d. Cooking loss was greater (P < 0.01) for Angus than Wagyu steaks at 72 h and 14 d. Using Wagyu sires vs. Angus sires on British-based commercial cows combined with early weaning management strategies has the potential to produce a product with greater marbling, but is unlikely to significantly enhance tenderness.

Coordination Between Ribs Motion and Thoracoabdominal Volumes in Swimmers During Respiratory Maneuvers

PubMed Central

Sarro, Karine J.; Silvatti, Amanda P.; Barros, Ricardo M. L.

2008-01-01

This work aimed to verify if swimmers present better chest wall coordination during breathing than healthy non-athletes analyzing the correlation between ribs motion and the variation of thoracoabdominal volumes. The results of two up-to-date methods based on videogrammetry were correlated in this study. The first one measured the volumes of 4 separate compartments of the chest wall (superior thorax, inferior thorax, superior abdomen and inferior abdomen) as a function of time. The second calculated the rotation angle of the 2nd to the 10th ribs around the quasi-transversal axis also in function of time. The chest wall was represented by 53 markers, attached to the ribs, vertebrae, thorax and abdomen of 15 male swimmers and of 15 non- athletes. A kinematical analysis system equipped with 6 digital video cameras (60Hz) was used to obtain the 3D coordinates of the markers. Correlating the curves of ribs rotation angles with the curves of the separate volumes, swimmers presented higher values than non-athletes when the superior and inferior abdomen were considered and the highest correlation values were found in swimmers for the inferior thorax. These results suggest a better coordination between ribs motion and thoracoabdominal volumes in swimmers, indicating the prevalent and coordinated action of the diaphragm and abdominal muscles to inflate and deflate the chest wall. The results further suggest that swimming practice leads to the formation of an optimized breathing pattern and can partially explain the higher lung volumes found in these athletes reported in literature. Key pointsThe study revealed that swimmers present higher correlation between the ribs motion and the variation of abdominal volumes than non-swimmers, suggesting that swimming practice might lead to the formation of an optimized breathing pattern, increasing the coordination between the thoracoabdominal volumes and the ribs motion.No previous work was found in the literature reporting this optimized breathing pattern in swimmers.The higher coordination between the thoracoabdominal volumes and the ribs motion found in swimmers can partially explain the higher lung volumes reported in literature for these athletes. PMID:24149449

C7 vertebra homeotic transformation in domestic dogs - are Pug dogs breaking mammalian evolutionary constraints?

PubMed

Brocal, J; De Decker, S; José-López, R; Manzanilla, E G; Penderis, J; Stalin, C; Bertram, S; Schoenebeck, J J; Rusbridge, C; Fitzpatrick, N; Gutierrez-Quintana, R

2018-05-14

The number of cervical vertebrae in mammals is almost constant at seven, regardless of their neck length, implying that there is selection against variation in this number. Homebox (Hox) genes are involved in this evolutionary mammalian conservation, and homeotic transformation of cervical into thoracic vertebrae (cervical ribs) is a common phenotypic abnormality when Hox gene expression is altered. This relatively benign phenotypic change can be associated with fatal traits in humans. Mutations in genes upstream of Hox, inbreeding and stressors during organogenesis can also cause cervical ribs. The aim of this study was to describe the prevalence of cervical ribs in a large group of domestic dogs of different breeds, and explore a possible relation with other congenital vertebral malformations (CVMs) in the breed with the highest prevalence of cervical ribs. By phenotyping we hoped to give clues as to the underlying genetic causes. Twenty computed tomography studies from at least two breeds belonging to each of the nine groups recognized by the Federation Cynologique Internationale, including all the brachycephalic 'screw-tailed' breeds that are known to be overrepresented for CVMs, were reviewed. The Pug dog was more affected by cervical ribs than any other breed (46%; P < 0.001), and was selected for further analysis. No association was found between the presence of cervical ribs and vertebral body formation defect, bifid spinous process, caudal articular process hypoplasia/aplasia and an abnormal sacrum, which may infer they have a different aetiopathogenesis. However, Pug dogs with cervical ribs were more likely to have a transitional thoraco-lumbar vertebra (P = 0.041) and a pre-sacral vertebral count of 26 (P < 0.001). Higher C7/T1 dorsal spinous processes ratios were associated with the presence of cervical ribs (P < 0.001), supporting this is a true homeotic transformation. Relaxation of the stabilizing selection has likely occurred, and the Pug dog appears to be a good naturally occurring model to further investigate the aetiology of cervical ribs, other congenital vertebral anomalies and numerical alterations. © 2018 Anatomical Society.

Low-loss curved subwavelength grating waveguide based on index engineering

NASA Astrophysics Data System (ADS)

Wang, Zheng; Xu, Xiaochuan; Fan, D. L.; Wang, Yaoguo; Chen, Ray T.

2016-03-01

Subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to its freedom to tune a few important waveguide properties such as dispersion and refractive index. Devices based on SWG waveguide have demonstrated impressive performances compared to those of conventional waveguides. However, the large loss of SWG waveguide bends jeopardizes their applications in integrated photonics circuits. In this work, we propose that a predistorted refractive index distribution in SWG waveguide bends can effectively decrease the mode mismatch noise and radiation loss simultaneously, and thus significantly reduce the bend loss. Here, we achieved the pre-distortion refractive index distribution by using trapezoidal silicon pillars. This geometry tuning approach is numerically optimized and experimentally demonstrated. The average insertion loss of a 5 μm SWG waveguide bend can be reduced drastically from 5.58 dB to 1.37 dB per 90° bend for quasi-TE polarization. In the future, the proposed approach can be readily adopted to enhance performance of an array of SWG waveguide-based photonics devices.

Quasi-phase matching and quantum control of high harmonic generation in waveguides using counterpropagating beams

DOEpatents

Zhang, Xiaoshi; Lytle, Amy L.; Cohen, Oren; Kapteyn, Henry C.; Murnane, Margaret M.

2010-11-09

All-optical quasi-phase matching (QPM) uses a train of counterpropagating pulses to enhance high-order harmonic generation (HHG) in a hollow waveguide. A pump pulse enters one end of the waveguide, and causes HHG in the waveguide. The counterpropagation pulses enter the other end of the waveguide and interact with the pump pulses to cause QPM within the waveguide, enhancing the HHG.

Do we Underestimate the Importance of Leaf Size in Plant Economics? Disproportional Scaling of Support Costs Within the Spectrum of Leaf Physiognomy

PubMed Central

Niinemets, Ülo; Portsmuth, Angelika; Tena, David; Tobias, Mari; Matesanz, Silvia; Valladares, Fernando

2007-01-01

Background Broad scaling relationships between leaf size and function do not take into account that leaves of different size may contain different fractions of support in petiole and mid-rib. Methods The fractions of leaf biomass in petiole, mid-rib and lamina, and the differences in chemistry and structure among mid-ribs, petioles and laminas were investigated in 122 species of contrasting leaf size, life form and climatic distribution to determine the extent to which differences in support modify whole-lamina and whole-leaf structural and chemical characteristics, and the extent to which size-dependent support investments are affected by plant life form and site climate. Key Results For the entire data set, leaf fresh mass varied over five orders of magnitude. The percentage of dry mass in mid-rib increased strongly with lamina size, reaching more than 40 % in the largest laminas. The whole-leaf percentage of mid-rib and petiole increased with leaf size, and the overall support investment was more than 60 % in the largest leaves. Fractional support investments were generally larger in herbaceous than in woody species and tended to be lower in Mediterranean than in cool temperate and tropical plants. Mid-ribs and petioles had lower N and C percentages, and lower dry to fresh mass ratio, but greater density (mass per unit volume) than laminas. N percentage of lamina without mid-rib was up to 40 % higher in the largest leaves than the total-lamina (lamina and mid-rib) N percentage, and up to 60 % higher than whole-leaf N percentage, while lamina density calculated without mid-rib was up to 80 % less than that with the mid-rib. For all leaf compartments, N percentage was negatively associated with density and dry to fresh mass ratio, while C percentage was positively linked to these characteristics, reflecting the overall inverse scaling between structural and physiological characteristics. However, the correlations between N and C percentages and structural characteristics differed among mid-ribs, petioles and laminas, implying that the mass-weighted average leaf N and C percentage, density, and dry to fresh mass ratio can have different functional values depending on the importance of within-leaf support investments. Conclusions These data demonstrate that variation in leaf size is associated with major changes in within-leaf support investments and in large modifications in integrated leaf chemical and structural characteristics. These size-dependent alterations can importantly affect general leaf structure vs. function scaling relationships. These data further demonstrate important life-form effects on and climatic differentiation in foliage support costs. PMID:17586597

Local heat/mass transfer distributions around sharp 180 deg turns in two-pass smooth and rib-roughened channels

NASA Technical Reports Server (NTRS)

Han, J. C.; Chandra, P. R.; Lau, S. C.

1988-01-01

The napthalene sublimation technique was employed to study the detailed mass transfer distributions around the sharp 180 deg turns in a two-pass, square, smooth channel and in an identical channel with two rib-roughened opposite walls. Experiments conducted for Reynolds numbers of 15,000, 30,000, and 60,000 indicate that the Sherwood numbers on the top, outer, and inner walls around the turn in the rib-roughened channel are higher than the corresponding Sherwood numbers around the turn in the smooth channel. Sherwood numbers after the sharp turn are found to be higher than those before the turn for both the smooth and the ribbed channels.

Compound semiconductor optical waveguide switch

DOEpatents

Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

2003-06-10

An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

FIBER AND INTEGRATED OPTICS: New method for determination of the parameters of a channel waveguide

NASA Astrophysics Data System (ADS)

Galechyan, M. G.; Dianov, Evgenii M.; Lyndin, N. M.; Sychugov, V. A.; Tishchenko, A. V.; Usievich, B. A.

1992-02-01

A new method for the determination of the parameters of channel integrated optical waveguides is proposed. This method is based on measuring the spectral transmission of a system comprising the investigated waveguide and single-mode fiber waveguides, which are brought into contact with the channel waveguide. The results are reported of an investigation of two channel waveguides formed in glass by a variety of methods and characterized by different refractive index profiles. The proposed method is found to be suitable for determination of the parameters of the refractive index profile of the investigated channel waveguides.

Optical panel system including stackable waveguides

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeSanto, Leonard; Veligdan, James T.

An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, whereinmore » each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.« less

Microfabricated Waveguide Atom Traps.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jau, Yuan-Yu

A nanoscale , microfabricated waveguide structure can in - principle be used to trap atoms in well - defined locations and enable strong photon-atom interactions . A neutral - atom platform based on this microfabrication technology will be prealigned , which is especially important for quantum - control applications. At present, there is still no reported demonstration of evanescent - field atom trapping using a microfabricated waveguide structure. We described the capabilities established by our team for future development of the waveguide atom - trapping technology at SNL and report our studies to overcome the technical challenges of loading coldmore » atoms into the waveguide atom traps, efficient and broadband optical coupling to a waveguide, and the waveguide material for high - power optical transmission. From the atomic - physics and the waveguide modeling, w e have shown that a square nano-waveguide can be utilized t o achieve better atomic spin squeezing than using a nanofiber for first time.« less

Dielectric-loaded waveguide circulator for cryogenically cooled and cascaded maser waveguide structures

NASA Technical Reports Server (NTRS)

Clauss, R. C.; Quinn, R. B. (Inventor)

1980-01-01

A dielectrically loaded four port waveguide circulator is used with a reflected wave maser connected to a second port between first and third ports to form one of a plurality of cascaded maser waveguide structures. The fourth port is connected to a waveguide loaded with microwave energy absorbing material. The third (output signal) port of one maser waveguide structure is connected by a waveguide loaded with dielectric material to the first (input) port of an adjacent maser waveguide structure, and the second port is connected to a reflected wave maser by a matching transformer which passes the signal to be amplified into and out of the reflected wavemaser and blocks pumping energy in the reflected wave maser from entering the circulator. A number of cascaded maser waveguide structures are thus housed in a relatively small volume of conductive material placed within a cryogenically cooled magnet assembly.

An analog of photon-assisted tunneling in a periodically modulated waveguide array

PubMed Central

Li, Liping; Luo, Xiaobing; Yang, Xiaoxue; Wang, Mei; Lü, Xinyou; Wu, Ying

2016-01-01

We theoretically report an analog of photon-assisted tunneling (PAT) originated from dark Floquet state in a periodically driven lattice array without a static biased potential by studying a three-channel waveguide system in a non-high-frequency regime. This analog of PAT can be achieved by only periodically modulating the top waveguide and adjusting the distance between the bottom and its adjacent waveguide. It is numerically shown that the PAT resonances also exist in the five-channel waveguide system and probably exist in the waveguide arrays with other odd numbers of waveguides, but they will become weak as the number of waveguides increases. With origin different from traditional PAT, this type of PAT found in our work is closely linked to the existence of the zero-energy (dark) Floquet states. It is readily observable under currently accessible experimental conditions and may be useful for controlling light propagation in waveguide arrays. PMID:27767189

Optical panel system including stackable waveguides

DOEpatents

DeSanto, Leonard; Veligdan, James T.

2007-03-06

An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

Slow-light enhanced subwavelength plasmonic waveguide refractive index sensors.

PubMed

Huang, Yin; Min, Changjun; Dastmalchi, Pouya; Veronis, Georgios

2015-06-01

We introduce slow-light enhanced subwavelength scale refractive index sensors which consist of a plasmonic metal-dielectric-metal (MDM) waveguide based slow-light system sandwiched between two conventional MDM waveguides. We first consider a MDM waveguide with small width structrue for comparison, and then consider two MDM waveguide based slow light systems: a MDM waveguide side-coupled to arrays of stub resonators system and a MDM waveguide side-coupled to arrays of double-stub resonators system. We find that, as the group velocity decreases, the sensitivity of the effective index of the waveguide mode to variations of the refractive index of the fluid filling the sensors as well as the sensitivities of the reflection and transmission coefficients of the waveguide mode increase. The sensing characteristics of the slow-light waveguide based sensor structures are systematically analyzed. We show that the slow-light enhanced sensors lead to not only 3.9 and 3.5 times enhancements in the refractive index sensitivity, and therefore in the minimum detectable refractive index change, but also to 2 and 3 times reductions in the required sensing length, respectively, compared to a sensor using a MDM waveguide with small width structure.

Sustained relief of pain from osteosynthesis surgery of rib fracture by using biodegradable lidocaine-eluting nanofibrous membranes.

PubMed

Yu, Yi-Hsun; Hsu, Yung-Heng; Chou, Ying-Chao; Fan, Chin-Lung; Ueng, Steve W N; Kau, Yi-Chuan; Liu, Shih-Jung

2016-10-01

Various effective methods are available for perioperative pain control in osteosynthesis surgery, but they are seldom applied intraoperatively. The aim of this study was to evaluate a biodegradable poly([d,l]-lactide-co-glycolide) (PLGA)/lidocaine nanofibrous membrane for perioperative pain control in rib fracture surgery. Scanning electron microscopy showed high porosity of the membrane, and an ex vivo high-performance liquid chromatography study revealed an excellent release profile for both burst and controlled release of lidocaine within 30days. Additionally, the PLGA/lidocaine nanofibrous membrane was applied in an experimental rabbit rib osteotomy model. Implantation of the membrane around the osteotomized rib during osteosynthesis surgery resulted in a significant increase in weight gain, food and water consumption, and daily activity compared to the study group without the membrane. In addition, all osteotomized ribs were united. Thus, application of the PLGA/lidocaine nanofibrous membrane may be effective for sustained relief of pain in oeteosynthesis surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Spondylocostal dysostosis associated with right-sided polythelia, right-sided rib deformity and meningocoele: Case report with review of literature

PubMed Central

Rai, Narendra; Thakur, Neha; Khan, Naheed Zin; Dwivedi, Akhilesh Dutt

2015-01-01

Spondylocostal dysostosis (SCD) is a rare anomaly of axial skeleton due to flawed embryological development. A newborn baby boy with right-sided polythelia, meningocoele, fan-like configuration of third and fourth rib, fused fifth and sixth rib and third thoracic hemivertebra was delivered to a second gravid mother by elective caesarean section. Baby was active, cried immediately after birth, had normal muscle tone and reflexes. He passed urine and meconium within 24 h of birth. Based on clinical examination and radiological picture, a diagnosis of SCD with meningocele with right-sided polythelia was made. Our case is the first SCD with polythelia and meningocele in newborn. SCD with right-sided polythelia and rib deformity with neural tube defect (NTD) may be due to a genetic defect with the culprit genes missing. Further genetic and embryological studies might find a link between right-sided rib defects, polythelia and NTD. PMID:26962344

Molecular-Flow Properties of RIB Type Vapor-Transport Systems Using a Fast-Valve

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alton, Gerald D; Bilheux, Hassina Z; Zhang, Y.

2014-01-01

The advent of the fast-valve device, described previously, permits measurement of molecular-flow times of chemically active or inactive gaseous species through radioactive ion beam (RIB) target ion source systems, independent of size, geometry and materials of construction. Thus, decay losses of short-half-life RIBs can be determined for a given target/vapor-transport system in advance of on-line operation, thereby ascertaining the feasibility of the system design for successful processing of a given isotope. In this article, molecular-flow-time theory and experimentally measured molecular-flow time data are given for serial- and parallel-coupled Ta metal RIB vapor-transport systems similar to those used at ISOL basedmore » RIB facilities. In addition, the effect of source type on the molecular-flow time properties of a given system is addressed, and a chemical passivation method for negating surface adsorption enthalpies for chemically active gaseous species on Ta surfaces is demonstrated.« less

Increased clutter level in echocardiography due to specular reflection

NASA Astrophysics Data System (ADS)

Fatemi, Ali; Torp, Hans; Aakhus, Svend; Rodriguez-Molares, Alfonso

2017-03-01

State-of-the-art echocardiography allows to correctly diagnose most of cardiovascular diseases. An unknown source of clutter, however, hinders the visualization of the heart in some cases. We believe this clutter is caused by the ultrasound beam being partially reflected by the ribs into the elevation direction, so that structures outside the imaging plane are displayed on top of the heart image as clutter noise. We conducted in vitro experiments in a water tank using a synthetic ventricle and pig ribs. By partially blocking the probe with the ribs in the elevation direction, objects outside the imaging plane were rendered in the B-mode image, which confirms that the ribs can behave as specular reflectors. In addition, we succeeded in reproducing clutter noise using a piece of polystyrene to simulate the reflections from the lungs. This indicates that the origin of the clutter noise in echocardiograms can be reverberation coming from the lungs via specular reflection at the ribs.

Sonography of occult rib and costal cartilage fractures: a case series.

PubMed

Mattox, Ross; Reckelhoff, Kenneth E; Welk, Aaron B; Kettner, Norman W

2014-06-01

The purpose of this case series is to describe the use of diagnostic ultrasound (US) in the detection of occult rib and costal cartilage fractures presenting as chest wall pain to a chiropractic clinic. Three patients presented with chest wall pain and tenderness. Two of the patients presented with acute chest wall injury and 1 carried a previous diagnosis of rib fracture after trivial trauma 2 months earlier. Diagnostic US was selected as a non-ionizing imaging tool for these patients after negative digital radiography studies. All fractures were considered isolated as there was no associated injury, such as pneumothorax. Both of the acute cases were followed up to complete healing (evidence of osseous union) using US. All patients eventually achieved pain-free status. In these cases, US was more sensitive than radiography for diagnosing these cases of acute rib and costal cartilage fractures. Early recognition of rib injury could avoid potential complications from local manipulative therapy.

Surgical Treatment of Snapping Scapula Syndrome Due to Malunion of Rib Fractures.

PubMed

Ten Duis, Kaj; IJpma, Frank F A

2017-02-01

This report describes a case of snapping scapula syndrome (SSS) caused by malunited rib fractures. Abrasion of the deformed ribs was performed with good results. SSS as a cause of shoulder pain after thoracic trauma has to be considered and can be treated by a surgical abrasion technique. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Buckling Tests with a Spar-rib Grill

NASA Technical Reports Server (NTRS)

Weinhold, Josef

1940-01-01

The present report deals with a comparison of mathematically and experimentally defined buckling loads of a spar-rib grill, on the assumption of constant spar section, and infinitely closely spaced ribs with rigidity symmetrical to the grill center. The loads are applied as equal bending moments at both spar ends, as compression in the line connecting the joints, and in the spar center line as the assumedly uniformly distributed spar weight.

Manufacturing and assembly of IWS support rib and lower bracket for ITER vacuum vessel

NASA Astrophysics Data System (ADS)

Laad, R.; Sarvaiya, Y.; Pathak, H. A.; Raval, J. R.; Choi, C. H.

2017-04-01

ITER Vacuum Vessel (VV) is made of double walls connected by ribs structure and flexible housings. Space between these walls is filled up with In Wall Shielding (IWS) blocks to (1) shield neutrons streaming out of plasma and (2) reduce toroidal magnetic field ripple. These blocks will be connected to the VV through a supporting structure of Support Rib (SR) and Lower Bracket (LB) assembly. SR and LB are two independent components manufactured from SS 316L(N)-IG, Total 1584 support ribs and 3168 lower bracket of different sizes and shapes will be manufactured for the IWS. Two lower brackets will be welded with one support rib to make an assembly. The welding between SR and LB is a full penetration welding. Total 1584 assemblies of different sizes and shapes will be manufactured. Sufficient experience gained from manufacturing and testing of mock ups, final manufacturing of IWS support rib and lower bracket has been started at the site of IWS manufacturer M/s. Avasarala Technologies Limited (ATL). This paper will describe, optimization of water jet cutting speed on IWS material, selection criteria for K type weld joint, unique features of fixture of assembly, manufacturing of Mock ups, and welding processes with NDTs.

Validation of automatic segmentation of ribs for NTCP modeling.

PubMed

Stam, Barbara; Peulen, Heike; Rossi, Maddalena M G; Belderbos, José S A; Sonke, Jan-Jakob

2016-03-01

Determination of a dose-effect relation for rib fractures in a large patient group has been limited by the time consuming manual delineation of ribs. Automatic segmentation could facilitate such an analysis. We determine the accuracy of automatic rib segmentation in the context of normal tissue complication probability modeling (NTCP). Forty-one patients with stage I/II non-small cell lung cancer treated with SBRT to 54 Gy in 3 fractions were selected. Using the 4DCT derived mid-ventilation planning CT, all ribs were manually contoured and automatically segmented. Accuracy of segmentation was assessed using volumetric, shape and dosimetric measures. Manual and automatic dosimetric parameters Dx and EUD were tested for equivalence using the Two One-Sided T-test (TOST), and assessed for agreement using Bland-Altman analysis. NTCP models based on manual and automatic segmentation were compared. Automatic segmentation was comparable with the manual delineation in radial direction, but larger near the costal cartilage and vertebrae. Manual and automatic Dx and EUD were significantly equivalent. The Bland-Altman analysis showed good agreement. The two NTCP models were very similar. Automatic rib segmentation was significantly equivalent to manual delineation and can be used for NTCP modeling in a large patient group. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Propagation losses in undoped and n-doped polycrystalline silicon wire waveguides.

PubMed

Zhu, Shiyang; Fang, Q; Yu, M B; Lo, G Q; Kwong, D L

2009-11-09

Polycrystalline silicon (polySi) wire waveguides with width ranging from 200 to 500 nm are fabricated by solid-phase crystallization (SPC) of deposited amorphous silicon (a-Si) on SiO(2) at a maximum temperature of 1000 degrees C. The propagation loss at 1550 nm decreases from 13.0 to 9.8 dB/cm with the waveguide width shrinking from 500 to 300 nm while the 200-nm-wide waveguides exhibit quite large loss (>70 dB/cm) mainly due to the relatively rough sidewall of waveguides induced by the polySi dry etch. By modifying the process sequence, i.e., first patterning the a-Si layer into waveguides by dry etch and then SPC, the sidewall roughness is significantly improved but the polySi crystallinity is degraded, leading to 13.9 dB/cm loss in the 200-nm-wide waveguides while larger losses in the wider waveguides. Phosphorus implantation causes an additional loss in the polySi waveguides. The doping-induced optical loss increases relatively slowly with the phosphorus concentration increasing up to 1 x 10(18) cm(-3), whereas the 5 x 10(18) cm(-3) doped waveguides exhibit large loss due to the dominant free carrier absorption. For all undoped polySi waveguides, further 1-2 dB/cm loss reduction is obtained by a standard forming gas (10%H(2) + 90%N(2)) annealing owing to the hydrogen passivation of Si dangling bonds present in polySi waveguides, achieving the lowest loss of 7.9 dB/cm in the 300-nm-wide polySi waveguides. However, for the phosphorus doped polySi waveguides, the propagation loss is slightly increased by the forming gas annealing.

Diagnostic significance of rib series in minor thorax trauma compared to plain chest film and computed tomography.

PubMed

Hoffstetter, Patrick; Dornia, Christian; Schäfer, Stephan; Wagner, Merle; Dendl, Lena M; Stroszczynski, Christian; Schreyer, Andreas G

2014-01-01

Rib series (RS) are a special radiological technique to improve the visualization of the bony parts of the chest. The aim of this study was to evaluate the diagnostic accuracy of rib series in minor thorax trauma. Retrospective study of 56 patients who received RS, 39 patients where additionally evaluated by plain chest film (PCF). All patients underwent a computed tomography (CT) of the chest. RS and PCF were re-read independently by three radiologists, the results were compared with the CT as goldstandard. Sensitivity, specificity, negative and positive predictive value were calculated. Significance in the differences of findings was determined by McNemar test, interobserver variability by Cohens kappa test. 56 patients were evaluated (34 men, 22 women, mean age =61 y.). In 22 patients one or more rib fracture could be identified by CT. In 18 of these cases (82%) the correct diagnosis was made by RS, in 16 cases (73%) the correct number of involved ribs was detected. These differences were significant (p = 0.03). Specificity was 100%, negative and positive predictive value were 85% and 100%. Kappa values for the interobserver agreement was 0.92-0.96. Sensitivity of PCF was 46% and was significantly lower (p = 0.008) compared to CT. Rib series does not seem to be an useful examination in evaluating minor thorax trauma. CT seems to be the method of choice to detect rib fractures, but the clinical value of the radiological proof has to be discussed and investigated in larger follow up studies.

CFD analysis to study effect of circular vortex generator placed in inlet section to investigate heat transfer aspects of solar air heater.

PubMed

Gawande, Vipin B; Dhoble, A S; Zodpe, D B

2014-01-01

CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate.

Prevalence and characteristics of rib fractures in ex-preterm infants.

PubMed

Lucas-Herald, Angela; Butler, Sandra; Mactier, Helen; McDevitt, Helen; Young, David; Ahmed, Syed Faisal

2012-12-01

This study aimed to identify the prevalence and characteristics of rib fractures in ex-preterm infants. Infants born at <37 weeks' gestation and admitted before 2011 to 3 regional neonatal units were identified from admission registers. For 2 centers, these data were available from 2000 onward and, for another center, from 2005. Electronic records were searched to identify chest radiographs performed up to age 1 year. Chest radiograph reports were then reviewed for evidence of rib fractures, and the case notes of all affected individuals were scrutinized. Of the 3318 eligible preterm infants, 1446 had a total of 9386 chest radiographs. Of these infants, 26 (1.8%) were identified as having a total of 62 rib fractures. Their median (range) gestation at birth was 26 weeks (23-34). The median chronological age of these infants at the time of the radiograph was 14 weeks (5 weeks to 8 months). The median corrected gestational age at the time of the radiograph was 39 weeks (34 weeks to 4 months). Of the 62 fractures, 27 (36%) were sited posteriorly, and 15 (53%) of the infants with posterior rib fractures were diagnosed with osteopathy of prematurity. Classic risk including conjugated hyperbilirubinemia and diuretics, were present in 23 of 26 (88%) infants. A full skeletal survey was performed in 8 of 26 (31%). Investigations for nonaccidental injury occurred in 4 of 26 (15%) cases. Evidence of rib fractures is present in ~2% of ex-preterm infants. The evaluation of these fractures in infancy requires a detailed neonatal history irrespective of the site of rib fracture.

The Efficacy of Platelet-Rich Plasma in the Treatment of Rib Fractures.

PubMed

Gunay, Samil; Candan, Huseyin; Yılmaz, Rahsan; Eser, Irfan; Aydoğmus, Umit

2017-10-01

Background  Rib fracture is the most common result of thoracic traumas. Intrapulmonary shunt, alveolar capillary membrane damage, intra-alveolar hemorrhage, and hypoxia may develop following rib fractures. Therefore, prompt treatment is important. The aim of this experimental study was to analyze the effects of platelet-rich plasma (PRP) on rib fractures to secure a speedier and more efficient treatment method. Materials and Methods  The study involved 18 New Zealand white rabbits, randomly divided into three groups as Group 1, the sham group with no surgical intervention; Group 2, the control group in which simple rib fractures were applied and no treatment; and Group 3, in which rib fractures were applied and then PRP treatment was administered. Results  The mean recovery plate thickness measurements were found to be statistically significantly higher in the PRP group compared with the other groups ( p  < 0.005). A thicker fibrotic cell proliferation and the formation of many capillaries were observed around the growth plate in the PRP group compared with the other groups. These structures were lesser in the control group compared with the PRP group and at the lowest level in the sham group. Larger and distinct callus formation was observed and a new intramedullary field in the PRP group. Conclusions  PRP is a reliable and effective autologous product with minimal side effects, which can be considered as an alternative treatment in patients with rib fractures and used easily in pseudoarthrosis, surgical fracture, or flail chest. Georg Thieme Verlag KG Stuttgart · New York.

CFD Analysis to Study Effect of Circular Vortex Generator Placed in Inlet Section to Investigate Heat Transfer Aspects of Solar Air Heater

PubMed Central

Gawande, Vipin B.; Dhoble, A. S.; Zodpe, D. B.

2014-01-01

CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate. PMID:25254251

Local distribution of wall static pressure and heat transfer on a rough flat plate impinged by a slot air jet

NASA Astrophysics Data System (ADS)

Meda, Adimurthy; Katti, Vadiraj V.

2017-08-01

The present work experimentally investigates the local distribution of wall static pressure and the heat transfer coefficient on a rough flat plate impinged by a slot air jet. The experimental parameters include, nozzle-to-plate spacing (Z /D h = 0.5-10.0), axial distance from stagnation point ( x/D h ), size of detached rib ( b = 4-12 mm) and Reynolds number ( Re = 2500-20,000). The wall static pressure on the surface is recorded using a Pitot tube and a differential pressure transmitter. Infrared thermal imaging technique is used to capture the temperature distribution on the target surface. It is observed that, the maximum wall static pressure occurs at the stagnation point ( x/D h = 0) for all nozzle-to-plate spacing ( Z/D h ) and rib dimensions studied. Coefficient of wall static pressure ( C p ) decreases monotonically with x/D h . Sub atmospheric pressure is evident in the detached rib configurations for jet to plate spacing up to 6.0 for all ribs studied. Sub atmospheric region is stronger at Z/D h = 0.5 due to the fluid accelerating under the rib. As nozzle to plate spacing ( Z/D h ) increases, the sub-atmospheric region becomes weak and vanishes gradually. Reasonable enhancement in both C p as well as Nu is observed for the detached rib configuration. Enhancement is found to decrease with the increase in the rib width. The results of the study can be used in optimizing the cooling system design.

Short video interventions to reduce mental health stigma: a multi-centre randomised controlled trial in nursing high schools.

PubMed

Winkler, Petr; Janoušková, Miroslava; Kožený, Jiří; Pasz, Jiří; Mladá, Karolína; Weissová, Aneta; Tušková, Eva; Evans-Lacko, Sara

2017-12-01

We aimed to assess whether short video interventions could reduce stigma among nursing students. A multi-centre, randomised controlled trial was conducted. Participating schools were randomly selected and randomly assigned to receive: (1) an informational leaflet, (2) a short video intervention or (3) a seminar involving direct contact with a service user. The Community Attitudes towards Mental Illness (CAMI) and Reported and Intended Behaviour Scale (RIBS) were selected as primary outcome measures. SPANOVA models were built and Cohen's d calculated to assess the overall effects in each of the trial arms. Compared to the baseline, effect sizes immediately after the intervention were small in the flyer arm (CAMI: d = 0.25; RIBS: d = 0.07), medium in the seminar arm (CAMI: d = 0.61; RIBS: d = 0.58), and medium in the video arm (CAMI: d = 0.49 RIBS: d = 0.26; n = 237). Effect sizes at the follow-up were vanishing in the flyer arm (CAMI: d = 0.05; RIBS: d = 0.04), medium in the seminar arm (CAMI: d = 0.43; RIBS: d = 0.26; n = 254), and small in the video arm (CAMI: d = 0.22 RIBS: d = 0.21; n = 237). Seminar had the strongest and relatively stable effect on students' attitudes and intended behaviour, but the effect of short video interventions was also considerable and stable over time. Since short effective video interventions are relatively cheap, conveniently accessible and easy to disseminate globally, we recommend them for further research and development.

Radio frequency (RF) microwave components and subsystems using loaded ridge waveguide

DOEpatents

Kang, Yoon W.

2013-08-20

A waveguide having a non-conductive material with a high permeability (.mu., .mu..sub.r for relative permeability) and/or a high permittivity (.di-elect cons., .di-elect cons..sub.r for relative permittivity) positioned within a housing. When compared to a hollow waveguide, the waveguide of this invention, reduces waveguide dimensions by .varies..mu. ##EQU00001## The waveguide of this invention further includes ridges which further reduce the size and increases the usable frequency bandwidth.

Silicone polymer waveguide bridge for Si to glass optical fibers

NASA Astrophysics Data System (ADS)

Kruse, Kevin L.; Riegel, Nicholas J.; Middlebrook, Christopher T.

2015-03-01

Multimode step index polymer waveguides achieve high-speed, (<10 Gb/s) low bit-error-rates for onboard and embedded circuit applications. Using several multimode waveguides in parallel enables overall capacity to reach beyond 100 Gb/s, but the intrinsic bandwidth limitations due to intermodal dispersion limit the data transmission rates within multimode waveguides. Single mode waveguides, where intermodal dispersion is not present, have the potential to further improve data transmission rates. Single mode waveguide size is significantly less than their multimode counterparts allowing for greater density of channels leading to higher bandwidth capacity per layer. Challenges in implementation of embedded single mode waveguides within printed circuit boards involves mass production fabrication techniques to create precision dimensional waveguides, precision alignment tolerances necessary to launch a mode, and effective coupling between adjoining waveguides and devices. An emerging need in which single mode waveguides can be utilized is providing low loss fan out techniques and coupling between on-chip transceiver devices containing Si waveguide structures to traditional single mode optical fiber. A polymer waveguide bridge for Si to glass optical fibers can be implemented using silicone polymers at 1310 nm. Fabricated and measured prototype devices with modeling and simulation analysis are reported for a 12 member 1-D tapered PWG. Recommendations and designs are generated with performance factors such as numerical aperture and alignment tolerances.

Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography.

PubMed

Dong, Zhi-Hui; Yang, Zhi-Gang; Chen, Tian-Wu; Chu, Zhi-Gang; Deng, Wen; Shao, Heng

2011-01-01

Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR=1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR=1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR= 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR= 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR=1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries.

Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography

PubMed Central

Dong, Zhi-hui; Yang, Zhi-gang; Chen, Tian-wu; Chu, Zhi-gang; Deng, Wen; Shao, Heng

2011-01-01

PURPOSE: Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). METHODS: We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. RESULTS: The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR = 1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR = 1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR = 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR = 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR = 1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. CONCLUSIONS: Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries. PMID:21789386

Impaired rib bone mass and quality in end-stage cystic fibrosis patients.

PubMed

Mailhot, Geneviève; Dion, Natalie; Farlay, Delphine; Rizzo, Sébastien; Bureau, Nathalie J; Jomphe, Valérie; Sankhe, Safiétou; Boivin, Georges; Lands, Larry C; Ferraro, Pasquale; Ste-Marie, Louis-Georges

2017-05-01

Advancements in research and clinical care have considerably extended the life expectancy of cystic fibrosis (CF) patients. However, with this extended survival come comorbidities. One of the leading co-morbidities is CF-related bone disease (CFBD), which progresses with disease severity and places patients at high risk for fractures, particularly of the ribs and vertebrae. Evidence that CF patients with vertebral fractures had higher bone mineral density (BMD) than the nonfracture group led us to postulate that bone quality is impaired in these patients. We therefore examined rib specimens resected at the time of lung transplant in CF patients to measure parameters of bone quantity and quality. In this exploratory study, we analysed 19 end-stage CF and 13 control rib specimens resected from otherwise healthy lung donors. BMD, bone microarchitecture, static parameters of bone formation and resorption and microcrack density of rib specimens were quantified by imaging, histomorphometric and histological methods. Variables reflecting the mineralization of ribs were assessed by digitized microradiography. The degree of bone mineralization (g/cm 3 ) and the heterogeneity index of the mineralization (g/cm 3 ) were calculated for trabecular and cortical bone. Compared to controls, CF ribs exhibited lower areal and trabecular volumetric BMD, decreased trabecular thickness and osteoid parameters, and increased microcrack density, that was particularly pronounced in specimens from patients with CF-related diabetes. Static parameters of bone resorption were similar in both groups. Degree of mineralization of total bone, but not heterogeneity index, was increased in CF specimens. The combination of reduced bone mass, altered microarchitecture, imbalanced bone remodeling (maintained bone resorption but decreased formation), increased microdamage and a small increase of the degree of mineralization, may lead to decreased bone strength, which, when coupled with chronic coughing and chest physical therapy, may provide an explanation for the increased incidence of rib fractures previously reported in this population. Copyright © 2017 Elsevier Inc. All rights reserved.

Prolonged pain and disability are common after rib fractures.

PubMed

Fabricant, Loic; Ham, Bruce; Mullins, Richard; Mayberry, John

2013-05-01

The contribution of rib fractures to prolonged pain and disability may be underappreciated and undertreated. Clinicians are traditionally taught that the pain and disability of rib fractures resolves in 6 to 8 weeks. This study was a prospective observation of 203 patients with rib fractures at a level 1 trauma center. Chest wall pain was evaluated by the McGill Pain Questionnaire (MPQ) pain rating index (PRI) and present pain intensity (PPI). Prolonged pain was defined as a PRI of 8 or more at 2 months after injury. Prolonged disability was defined as a decrease in 1 or more levels of work or functional status at 2 months after injury. Predictors of prolonged pain and disability were determined by multivariate analysis. One hundred forty-five male patients and 58 female patients with a mean injury severity score (ISS) of 20 (range, 1 to 59) had a mean of 5.4 rib fractures (range, 1 to 29). Forty-four (22%) patients had bilateral fractures, 15 (7%) had flail chest, and 92 (45%) had associated injury. One hundred eighty-seven patients were followed 2 months or more. One hundred ten (59%) patients had prolonged chest wall pain and 142 (76%) had prolonged disability. Among 111 patients with isolated rib fractures, 67 (64%) had prolonged chest wall pain and 69 (66%) had prolonged disability. MPQ PPI was predictive of prolonged pain (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.4 to 2.5), and prolonged disability (OR, 2.2; 95% CI, 1.5 to 3.4). The presence of significant associated injuries was predictive of prolonged disability (OR, 5.9; 95% CI, 1.4 to 29). Prolonged chest wall pain is common, and the contribution of rib fractures to disability is greater than traditionally expected. Further investigation into more effective therapies that prevent prolonged pain and disability after rib fractures is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluation of the iPhone with an acrylic sleeve versus the Scoliometer for rib hump measurement in scoliosis.

PubMed

Izatt, Maree T; Bateman, Gary R; Adam, Clayton J

2012-07-30

Vertebral rotation found in structural scoliosis contributes to trunkal asymmetry which is commonly measured with a simple Scoliometer device on a patient's thorax in the forward flexed position. The new generation of mobile 'smartphones' have an integrated accelerometer, making accurate angle measurement possible, which provides a potentially useful clinical tool for assessing rib hump deformity. This study aimed to compare rib hump angle measurements performed using a Smartphone and traditional Scoliometer on a set of plaster torsos representing the range of torsional deformities seen in clinical practice. Nine observers measured the rib hump found on eight plaster torsos moulded from scoliosis patients with both a Scoliometer and an Apple iPhone on separate occasions. Each observer repeated the measurements at least a week after the original measurements, and were blinded to previous results. Intra-observer reliability and inter-observer reliability were analysed using the method of Bland and Altman and 95% confidence intervals were calculated. The Intra-Class Correlation Coefficients (ICC) were calculated for repeated measurements of each of the eight plaster torso moulds by the nine observers. Mean absolute difference between pairs of iPhone/Scoliometer measurements was 2.1 degrees, with a small (1 degrees) bias toward higher rib hump angles with the iPhone. 95% confidence intervals for intra-observer variability were +/- 1.8 degrees (Scoliometer) and +/- 3.2 degrees (iPhone). 95% confidence intervals for inter-observer variability were +/- 4.9 degrees (iPhone) and +/- 3.8 degrees (Scoliometer). The measurement errors and confidence intervals found were similar to or better than the range of previously published thoracic rib hump measurement studies. The iPhone is a clinically equivalent rib hump measurement tool to the Scoliometer in spinal deformity patients. The novel use of plaster torsos as rib hump models avoids the variables of patient fatigue and discomfort, inconsistent positioning and deformity progression using human subjects in a single or multiple measurement sessions.

Evaluation of the iPhone with an acrylic sleeve versus the Scoliometer for rib hump measurement in scoliosis

PubMed Central

2012-01-01

Background Vertebral rotation found in structural scoliosis contributes to trunkal asymmetry which is commonly measured with a simple Scoliometer device on a patient's thorax in the forward flexed position. The new generation of mobile 'smartphones' have an integrated accelerometer, making accurate angle measurement possible, which provides a potentially useful clinical tool for assessing rib hump deformity. This study aimed to compare rib hump angle measurements performed using a Smartphone and traditional Scoliometer on a set of plaster torsos representing the range of torsional deformities seen in clinical practice. Methods Nine observers measured the rib hump found on eight plaster torsos moulded from scoliosis patients with both a Scoliometer and an Apple iPhone on separate occasions. Each observer repeated the measurements at least a week after the original measurements, and were blinded to previous results. Intra-observer reliability and inter-observer reliability were analysed using the method of Bland and Altman and 95% confidence intervals were calculated. The Intra-Class Correlation Coefficients (ICC) were calculated for repeated measurements of each of the eight plaster torso moulds by the nine observers. Results Mean absolute difference between pairs of iPhone/Scoliometer measurements was 2.1 degrees, with a small (1 degrees) bias toward higher rib hump angles with the iPhone. 95% confidence intervals for intra-observer variability were +/- 1.8 degrees (Scoliometer) and +/- 3.2 degrees (iPhone). 95% confidence intervals for inter-observer variability were +/- 4.9 degrees (iPhone) and +/- 3.8 degrees (Scoliometer). The measurement errors and confidence intervals found were similar to or better than the range of previously published thoracic rib hump measurement studies. Conclusions The iPhone is a clinically equivalent rib hump measurement tool to the Scoliometer in spinal deformity patients. The novel use of plaster torsos as rib hump models avoids the variables of patient fatigue and discomfort, inconsistent positioning and deformity progression using human subjects in a single or multiple measurement sessions. PMID:22846346

Ultra-large nonlinear parameter in graphene-silicon waveguide structures.

PubMed

Donnelly, Christine; Tan, Dawn T H

2014-09-22

Mono-layer graphene integrated with optical waveguides is studied for the purpose of maximizing E-field interaction with the graphene layer, for the generation of ultra-large nonlinear parameters. It is shown that the common approach used to minimize the waveguide effective modal area does not accurately predict the configuration with the maximum nonlinear parameter. Both photonic and plasmonic waveguide configurations and graphene integration techniques realizable with today's fabrication tools are studied. Importantly, nonlinear parameters exceeding 10(4) W(-1)/m, two orders of magnitude larger than that in silicon on insulator waveguides without graphene, are obtained for the quasi-TE mode in silicon waveguides incorporating mono-layer graphene in the evanescent part of the optical field. Dielectric loaded surface plasmon polariton waveguides incorporating mono-layer graphene are observed to generate nonlinear parameters as large as 10(5) W(-1)/m, three orders of magnitude larger than that in silicon on insulator waveguides without graphene. The ultra-large nonlinear parameters make such waveguides promising platforms for nonlinear integrated optics at ultra-low powers, and for previously unobserved nonlinear optical effects to be studied in a waveguide platform.

Geometrical tuning art for entirely subwavelength grating waveguide based integrated photonics circuits

DOE PAGES

Wang, Zheng; Xu, Xiaochuan; Fan, Donglei; ...

2016-05-05

Here, subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to the extra degree of freedom it offers in tuning a few important waveguide properties, such as dispersion and refractive index. Devices based on SWG waveguides have demonstrated impressive performances compared to conventional waveguides. However, the high loss of SWG waveguide bends jeopardizes their applications in integrated photonic circuits. In this work, we propose a geometrical tuning art, which realizes a pre-distorted refractive index profile in SWG waveguide bends. The pre-distorted refractive index profile can effectively reduce the mode mismatch and radiation loss simultaneously, thus significantlymore » reduce the bend loss. This geometry tuning art has been numerically optimized and experimentally demonstrated in present study. Through such tuning, the average insertion loss of a 5 μm SWG waveguide bend is reduced drastically from 5.43 dB to 1.10 dB per 90° bend for quasi-TE polarization. In the future, the proposed scheme will be utilized to enhance performance of a wide range of SWG waveguide based photonics devices.« less

Geometrical tuning art for entirely subwavelength grating waveguide based integrated photonics circuits

PubMed Central

Wang, Zheng; Xu, Xiaochuan; Fan, Donglei; Wang, Yaguo; Subbaraman, Harish; Chen, Ray T.

2016-01-01

Subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to the extra degree of freedom it offers in tuning a few important waveguide properties, such as dispersion and refractive index. Devices based on SWG waveguides have demonstrated impressive performances compared to conventional waveguides. However, the high loss of SWG waveguide bends jeopardizes their applications in integrated photonic circuits. In this work, we propose a geometrical tuning art, which realizes a pre-distorted refractive index profile in SWG waveguide bends. The pre-distorted refractive index profile can effectively reduce the mode mismatch and radiation loss simultaneously, thus significantly reduce the bend loss. This geometry tuning art has been numerically optimized and experimentally demonstrated in present study. Through such tuning, the average insertion loss of a 5 μm SWG waveguide bend is reduced drastically from 5.43 dB to 1.10 dB per 90° bend for quasi-TE polarization. In the future, the proposed scheme will be utilized to enhance performance of a wide range of SWG waveguide based photonics devices. PMID:27145872

Geometrical tuning art for entirely subwavelength grating waveguide based integrated photonics circuits.

PubMed

Wang, Zheng; Xu, Xiaochuan; Fan, Donglei; Wang, Yaguo; Subbaraman, Harish; Chen, Ray T

2016-05-05

Subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to the extra degree of freedom it offers in tuning a few important waveguide properties, such as dispersion and refractive index. Devices based on SWG waveguides have demonstrated impressive performances compared to conventional waveguides. However, the high loss of SWG waveguide bends jeopardizes their applications in integrated photonic circuits. In this work, we propose a geometrical tuning art, which realizes a pre-distorted refractive index profile in SWG waveguide bends. The pre-distorted refractive index profile can effectively reduce the mode mismatch and radiation loss simultaneously, thus significantly reduce the bend loss. This geometry tuning art has been numerically optimized and experimentally demonstrated in present study. Through such tuning, the average insertion loss of a 5 μm SWG waveguide bend is reduced drastically from 5.43 dB to 1.10 dB per 90° bend for quasi-TE polarization. In the future, the proposed scheme will be utilized to enhance performance of a wide range of SWG waveguide based photonics devices.

Investigation of heat transfer and flow using ribs within gas turbine blade cooling passage: Experimental and hybrid LES/RANS modeling

NASA Astrophysics Data System (ADS)

Kumar, Sourabh

Gas turbines are extensively used for aircraft propulsion, land based power generation and various industrial applications. Developments in innovative gas turbine cooling technology enhance the efficiency and power output, with an increase in turbine rotor inlet temperatures. These advancements of turbine cooling have allowed engine design to exceed normal material temperature limits. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream are based on the increase of heat transfer areas and on promotion of turbulence of the cooling flow. In this study, it is obtained by casting repeated continuous V and broken V shaped ribs on one side of the two pass square channel into the core of blade. Despite extensive research on ribs, only few papers have validated the numerical data with experimental results in two pass channel. In the present study, detailed experimental investigation is carried out for two pass square channels with 180° turn. Detailed heat transfer distribution occurring in the ribbed passage is reported for steady state experiment. Four different combinations of 60° and Broken 60° V ribs in channel are considered. Thermocouples are used to obtain the temperature on the channel surface and local heat transfer coefficients are obtained for various Reynolds numbers, within the turbulent flow regime. Area averaged data are calculated in order to compare the overall performance of the tested ribbed surface and to evaluate the degree of heat transfer enhancement induced by the ribs with. Flow within the channels is characterized by heat transfer enhancing ribs, bends, rotation and buoyancy effects. Computational Fluid Dynamics (CFD) simulations were carried out for the same geometries using different turbulence models such as k-o Shear stress transport (SST) and Reynolds stress model (RSM). These CFD simulations were based on advanced computing in order to improve the accuracy of three dimensional metal temperature prediction which can be applied routinely in the design stage of turbine cooled vanes and blades. This study presents an attempt to collect information about Nusselt number inside the ribbed duct and a series of measurement is performed in steady state eliminating the error sources inherently connected with transient method. A Large Eddy Simulation (LES) is carried out on the best V and Broken V rib arrangements to analyze the flow pattern inside the channel. A novel method is devised to analyze the results obtained from CFD simulation. Hybrid LES/Reynolds Averaged Navier Strokes (RANS) modeling is used to modify Reynolds stresses using Algebraic Stress Model (ASM).

Broadband photonic transport between waveguides by adiabatic elimination

NASA Astrophysics Data System (ADS)

Oukraou, Hassan; Coda, Virginie; Rangelov, Andon A.; Montemezzani, Germano

2018-02-01

We propose an adiabatic method for the robust transfer of light between the two outer waveguides in a three-waveguide directional coupler. Unlike the established technique inherited from stimulated Raman adiabatic passage (STIRAP), the method proposed here is symmetric with respect to an exchange of the left and right waveguides in the structure and permits the transfer in both directions. The technique uses the adiabatic elimination of the middle waveguide together with level crossing and adiabatic passage in an effective two-state system involving only the external waveguides. It requires a strong detuning between the outer and the middle waveguide and does not rely on the adiabatic transfer state (dark state) underlying the STIRAP process. The suggested technique is generalized to an array of N waveguides and verified by numerical beam propagation calculations.

Diffraction of an Electromagnetic Wave on a Dielectric Rod in a Rectangular Waveguide. A Method of Partial Waveguide Filling

NASA Astrophysics Data System (ADS)

Zav'yalov, A. S.

2018-04-01

A variant of the method of partial waveguide filling is considered in which a sample is put into a waveguide through holes in wide waveguide walls at the distance equal to a quarter of the wavelength in the waveguide from a short-circuiter, and the total input impedance of the sample in the waveguide is directly measured. The equivalent circuit of the sample is found both without and with account of the hole. It is demonstrated that consideration of the edge effect makes it possible to obtain more exact values of the dielectric permittivity.

Passive estimation of the waveguide invariant per pair of modes.

PubMed

Le Gall, Yann; Bonnel, Julien

2013-08-01

In many oceanic waveguides, acoustic propagation is characterized by a parameter called waveguide invariant. This property is used in many passive and active sonar applications where knowledge of the waveguide invariant value is required. The waveguide invariant is classically considered as scalar but several studies show that it is better modeled by a distribution because of its dependence on frequency and mode pairs. This paper presents a new method for estimating the waveguide invariant distribution. Using the noise radiated by a distant ship and a single hydrophone, the proposed methodology allows estimating the waveguide invariant for each pair of modes in shallow water. Performance is evaluated on simulated data.

FIBER AND INTEGRATED OPTICS: Noncollinear geometry for highly efficient excitation of a corrugated waveguide

NASA Astrophysics Data System (ADS)

Klimov, M. S.; Sychugov, V. A.; Tishchenko, A. V.

1992-02-01

An analysis is made of the process of light emission from a corrugated waveguide into air and into a substrate in a noncollinear geometry, i.e., when the direction along which the waveguide mode propagates does not coincide with the plane in which the emitted wave lies. Calculations show that when a TE mode is excited in a corrugated waveguide by a light beam with the TM polarization incident from air on the waveguide at a grazing angle, one can achieve a high waveguide excitation efficiency (~ 60%) if the waveguide mode propagates along the normal to the plane of incidence.

Guiding properties of asymmetric hybrid plasmonic waveguides on dielectric substrates

PubMed Central

2014-01-01

We proposed an asymmetric hybrid plasmonic waveguide which is placed on a substrate for practical applications by introducing an asymmetry into a symmetric hybrid plasmonic waveguide. The guiding properties of the asymmetric hybrid plasmonic waveguide are investigated using finite element method. The results show that, with proper waveguide sizes, the proposed waveguide can eliminate the influence of the substrate on its guiding properties and restore its broken symmetric mode. We obtained the maximum propagation length of 2.49 × 103 μm. It is approximately equal to that of the symmetric hybrid plasmonic waveguide embedded in air cladding with comparable nanoscale confinement. PMID:24406096

Waveguide Power-Amplifier Module for 80 to 150 GHz

NASA Technical Reports Server (NTRS)

Samoska, Lorene; Weinreb, Sander; Peralta, Alejandro

2006-01-01

A waveguide power-amplifier module capable of operating over the frequency range from 80 to 150 GHz has been constructed. The module comprises a previously reported power amplifier packaged in a waveguide housing that is compatible with WR-8 waveguides. (WR- 8 is a standard waveguide size for the nominal frequency range from 90 to 140 GHz.) The waveguide power-amplifier module is robust and can be bolted to test equipment and to other electronic circuits with which the amplifier must be connected for normal operation.

Dielectric waveguides for ultrahigh field magnetic resonance imaging.

PubMed

Bluemink, Johanna J; Raaijmakers, Alexander J E; Koning, Wouter; Andreychenko, Anna; Rivera, Debra S; Luijten, Peter R; Klomp, Dennis W J; van den Berg, Cornelis A T

2016-10-01

The design of RF coils for MRI transmit becomes increasingly challenging at high frequencies required for MRI at 7T and above. Our goal is to show a proof of principle of a new type of transmit coil for higher field strengths. We demonstrate an alternative transmit coil design based on dielectric waveguide principles which transfers energy via evanescent wave coupling. The operating principles and conditions are explored by simulations. The waveguide is applied for in vivo imaging at 7T. The waveguide can be an efficient transmit coil when four conditions are fulfilled: (1) the waveguide should be operated just above the cutoff frequency of the lowest order transverse electric mode, (2) the waveguide should not operate at a frequency where the wavelength fits an integer number of times in the waveguide length and standing wave patterns become very prominent, (3) for homogeneous excitation, the waveguide should be bent around the object, and (4) there should be an air gap between the waveguide and the object. By choosing the dielectric and the dimensions adequately, the dielectric waveguide couples the magnetic field efficiently into the body. The waveguide can be redesigned for higher frequencies by simple adaptations and may be a promising transmit alternative. Magn Reson Med 76:1314-1324, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Nanoscale devices based on plasmonic coaxial waveguide resonators

NASA Astrophysics Data System (ADS)

Mahigir, A.; Dastmalchi, P.; Shin, W.; Fan, S.; Veronis, G.

2015-02-01

Waveguide-resonator systems are particularly useful for the development of several integrated photonic devices, such as tunable filters, optical switches, channel drop filters, reflectors, and impedance matching elements. In this paper, we introduce nanoscale devices based on plasmonic coaxial waveguide resonators. In particular, we investigate threedimensional nanostructures consisting of plasmonic coaxial stub resonators side-coupled to a plasmonic coaxial waveguide. We use coaxial waveguides with square cross sections, which can be fabricated using lithography-based techniques. The waveguides are placed on top of a silicon substrate, and the space between inner and outer coaxial metals is filled with silica. We use silver as the metal. We investigate structures consisting of a single plasmonic coaxial resonator, which is terminated either in a short or an open circuit, side-coupled to a coaxial waveguide. We show that the incident waveguide mode is almost completely reflected on resonance, while far from the resonance the waveguide mode is almost completely transmitted. We also show that the properties of the waveguide systems can be accurately described using a single-mode scattering matrix theory. The transmission and reflection coefficients at waveguide junctions are either calculated using the concept of the characteristic impedance or are directly numerically extracted using full-wave three-dimensional finite-difference frequency-domain simulations.

New technique for fixing rib fracture with bioabsorbable plate.

PubMed

Oyamatsu, Hironori; Ohata, Norihisa; Narita, Kunio

2016-09-01

Fixation of a bone fracture with a bioabsorbable plate made of poly-L-lactide and hydroxyapatite has received attention. We adopted this technique for a rib fracture by bending the plate into a U-shape and fixing it with suture through the holes in the mesh of the plate and holes that are drilled in the edge of the fractured rib. The suture is also wound around the plate. © The Author(s) 2016.

Analysis of an optically controlled photonic switch.

PubMed

Attard, A E

1999-05-20

The principle that the coupling of light between two fiber waveguides can be controlled by the resonant interference of a third waveguide has been developed [Attard, Appl. Opt. 37, 2296-2302 (1998)]. Here significant details concerning the operation of a photonic switch are obtained, and a more complete analysis is presented. Multiple-resonant conditions are identified for slab and fiber control waveguides at large indices of refraction. Thus a selection of materials with an appropriate refractive index and a Kerr coefficient is rendered more easily. Furthermore it is shown that the light used to control the index of refraction in the control waveguide does not enter the output of the photonic switch but remains confined to the control waveguide, for either a slab or a multimode fiber control waveguide. Spatial fluctuations of the control light beam in the control waveguide do not affect the operation of the photonic switch. Tolerances have been determined for the spacing between the control waveguide and the photonic coupler and also for the index of refraction of the control waveguide.

Generation of radially-polarized terahertz pulses for coupling into coaxial waveguides

PubMed Central

Navarro-Cía, Miguel; Wu, Jiang; Liu, Huiyun; Mitrofanov, Oleg

2016-01-01

Coaxial waveguides exhibit no dispersion and therefore can serve as an ideal channel for transmission of broadband THz pulses. Implementation of THz coaxial waveguide systems however requires THz beams with radially-polarized distribution. We demonstrate the launching of THz pulses into coaxial waveguides using the effect of THz pulse generation at semiconductor surfaces. We find that the radial transient photo-currents produced upon optical excitation of the surface at normal incidence radiate a THz pulse with the field distribution matching the mode of the coaxial waveguide. In this simple scheme, the optical excitation beam diameter controls the spatial profile of the generated radially-polarized THz pulse and allows us to achieve efficient coupling into the TEM waveguide mode in a hollow coaxial THz waveguide. The TEM quasi-single mode THz waveguide excitation and non-dispersive propagation of a short THz pulse is verified experimentally by time-resolved near-field mapping of the THz field at the waveguide output. PMID:27941845

FIBER AND INTEGRATED OPTICS: Waveguide characteristics of real optical strip waveguides

NASA Astrophysics Data System (ADS)

Shmal'ko, A. V.; Frolov, V. V.

1990-01-01

A study is reported of the influence of the parameters of real thin-film optical strip waveguides on their waveguide characteristics (propagation constants, localization of the mode field, etc.) allowing for the presence of transition layers in a transverse cross section of the base planar waveguide, for the real geometry of this section (which is nearly trapezoidal), and for the thickness of the guiding strip. Analytic expressions are obtained for the optical confinement coefficient and the effective mode format of a weakly guiding symmetric strip waveguide. It is shown that the coefficient representing the fundamental E11x(y) mode is practically independent of the relative thickness t /h (h is the thickness of the base planar waveguide) of the guiding strip provided t /h>=0.5. The corrections to the normalized effective refractive indices of the base planar and strip waveguides are found in order to allow for the real geometry and for the refractive index profile in the strip waveguide.

Practical microstructured and plasmonic terahertz waveguides

NASA Astrophysics Data System (ADS)

Markov, Andrey

The terahertz frequency range, with frequencies lying between 100 GHz and 10 THz, has strong potential for various technological and scientific applications such as sensing, imaging, communications, and spectroscopy. Most terahertz (THz) sources are immobile and THz systems use free-space propagation in dry air where losses are minimal. Designing efficient THz waveguides for flexible delivery of broadband THz radiation is an important step towards practical applications of terahertz techniques. THz waveguides can be very useful on the system integration level when used for connection of the diverse THz point devices, such as sources, filters, sensor cells, detectors, etc. The most straightforward application of waveguides is to deliver electromagnetic waves from the source to the point of detection. Cumbersome free-space optics can be replaced by waveguides operating in the THz range, which could lead to the development of compact THz time domain spectroscopy systems. Other promising applications of THz waveguides are in sensing and imaging. THz waveguides have also been shown to operate in subwavelength regimes, offering mode confinement in waveguide structures with a size smaller than the diffraction limit, and thus, surpassing the resolution of free-space THz imaging systems. In order to design efficient terahertz waveguides, the frequency dependent loss and dispersion of the waveguide must be minimized. A possible solution would be to increase the fraction of mode power propagating through air. In this thesis, the usage of planar porous air/dielectric waveguides and metal wire/dielectric hybrid terahertz fibers will be discussed. First, I present a novel design of a planar porous low-loss waveguide, describe its fabrication, and characterize it in view of its potential applications as a low-loss waveguide and sensor in the THz spectral range. The waveguide structure features a periodic sequence of layers of thin (25-50 mum) polyethylene film that are separated by low-loss air layers of comparable thickness. A large fraction of the modal fields in these waveguides is guided in the low-loss air region, thus effectively reducing the waveguide transmission losses. I consider that such waveguides can be useful not only for low-loss THz wave delivery, but also for sensing of biological and chemical specimens in the terahertz region, by placing the recognition elements directly into the waveguide microstructure. The main advantage of the proposed planar porous waveguide is the convenient access to its optical mode, since the major portion of THz power launched into such a waveguide is confined within the air layers. Moreover, small spacing between the layers promotes rapid loading of the analyte into the waveguide due to strong capillary effect (< 1 s filling of a 10 cm long waveguide with an analyte). The transmission and absorption properties of such waveguides have been investigated both experimentally using THz-TDS spectroscopy and theoretically using finite element software. The modal refractive index of porous waveguides is smaller compared to pure polymer and it is easy to adjust by changing the air spacing between the layers, as well as the number of layers in the core. The porous waveguide exhibits considerably smaller transmission losses than bulk material. In the following chapters I review another promising approach towards designing of low-loss, low-dispersion THz waveguides. The hybrid metal/dielectric waveguides use a plasmonic mode guided in the gap between two parallel wires that are, in turn, encapsulated inside a low-loss, low-refractive index, micro-structured cladding that provides mechanical stability and isolation from the environment. I describe several promising techniques that can be used to encapsulate the two-wire waveguides, while minimizing the negative impact of dielectric cladding on the waveguide optical properties. In particular, I detail the use of low-density foams and microstructured plastic claddings as two enabling materials for the two-wire waveguide encapsulation. The hybrid fiber design is more convenient for practical applications than a classic two metal wire THz waveguide as it allows direct manipulations of the fiber without the risk of perturbing its core-guided mode. I present a detailed analysis of the modal properties of the hybrid metal/dielectric waveguides, compare them with the properties of a classic two-wire waveguide, and then present strategies for the improvement of hybrid waveguide performance by using higher cladding porosity or utilizing inherently porous cladding material. I study coupling efficiency into hybrid waveguides and conclude that it can be relatively high (>50%) in the broad frequency range ˜0.5 THz. Not surprisingly, optical properties of such fibers are inferior to those of a classic two-wire waveguide due to the presence of lossy dielectric near an inter-wire gap. At the same time, composite fibers outperform porous fibers of the same geometry both in bandwidth of operation and in lower dispersion. I demonstrate that hybrid metal/dielectric porous waveguides can have a very large operational bandwidth, while supporting tightly confined, air-bound modes both at high and low frequencies. This is possible as, at higher frequencies, hybrid fibers can support ARROW-like low-loss air-bound modes, while changing their guidance mechanism to plasmonic confinement in the inter-wire air gap at lower frequencies. Finally, I describe an intriguing resonant property of some hybrid plasmonic modes of metal / dielectric waveguides that manifests itself in the strong frequency dependent change in the modal confinement from dielectric-bound to air-bound. I discuss how this property can be used to construct THz refractometers. Introduction of even lossless analytes into the fiber core leads to significant changes in the modal losses, which is used as a transduction mechanism. The resolution of the refractometer has been investigated numerically as a function of the operation frequency and the geometric parameters of the fiber. With a refractive index resolution on the order of ˜10-3 RIU, the composite fiber-based sensor is capable of identifying various gaseous analytes and aerosols or measuring the concentration of dust particles in the air.

Integrated optical refractometer based on bend waveguide with air trench structure

NASA Astrophysics Data System (ADS)

Ryu, Jin Hwa; Park, Jaehoon; Kang, Chan-mo; Son, Youngdal; Do, Lee-Mi; Baek, Kyu-Ha

2015-07-01

This study proposed a novel optical sensor based on a refractometer integrating a bend waveguide and a trench structure. The optical sensor is a planar lightwave circuit (PLC) device involving a bend waveguide with maximum optical loss. A trench structure was aligned with the partially exposed core layer's sidewall of the bend waveguide, providing a quantitative measurement condition. The insertion losses of the proposed 1 x 2 single-mode optical splitter-type sensor were 4.38 dB and 8.67 dB for the reference waveguide and sensing waveguide, respectively, at a wavelength of 1,550 nm. The optical loss of the sensing waveguide depends on the change in the refractive index of the material in contact with the trench, but the reference waveguide had stable optical propagating characteristic regardless of the variations of the refractive index.

Tapered waveguides for guided wave optics.

PubMed

Campbell, J C

1979-03-15

Strip waveguides having half-paraboloid shaped tapers that permit efficient fiber to waveguide coupling have been fabricated by Ag ion exchange in soda-lime glass. A reduction in the input coupling loss has been accomplished by tailoring the diffusion to provide a gradual transition from a single-mode waveguide to a multimode waveguide having cross-sectional dimensions comparable to the core diameter of a single-mode fiber. Waveguides without tapers exhibit an attenuation of 1.0 dB/cm and an input coupling loss of 0.6 dB. The additional loss introduced by the tapered region is 0.5 dB. By way of contrast, an input coupling loss of 2.4 dB is obtained by coupling directly to a single-mode waveguide, indicating a net improvement of 1.3 dB for the tapered waveguides.

An efficient high-frequency analysis of modal reflection and transmission coefficients for a class of waveguide discontinuities

NASA Technical Reports Server (NTRS)

Pathak, P. H.; Altintas, A.

1988-01-01

A high-frequency analysis of electromagnetic modal reflection and transmission coefficients is presented for waveguide discontinuities formed by joining different waveguide sections. The analysis uses an extended version of the concept of geometrical theory of diffraction based equivalent edge currents in conjunction with the reciprocity theorem to describe interior scattering effects. If the waveguide modes and their associated modal rays can be found explicitly, general two- and three-dimensional waveguide geometries can be analyzed. Expressions are developed for two-dimensional reflection and transmission coefficients. Numerical results are given for a flanged, semi-infinite parallel plate waveguide and for the junction between two linearly tapered waveguides.

Polarization-dependent coupling between a polarization-independent high-index-contrast subwavelength grating and waveguides

NASA Astrophysics Data System (ADS)

Katayama, Takeo; Ito, Jun; Kawaguchi, Hitoshi

2016-07-01

We investigated the optical coupling between a polarization-independent high-index-contrast subwavelength grating (HCG) and two orthogonal in-plane waveguides. We fabricated the HCG with waveguides on a silicon-on-insulator substrate and demonstrated that a waveguide with a strong output is switched by changing the polarization of light injected into the HCG. The light coupled more strongly to the waveguide in the direction perpendicular to the polarization of the incident light than to that in the parallel direction. If this waveguide-coupled HCG is incorporated into a polarization bistable vertical-cavity surface-emitting laser (VCSEL), the output waveguide can be switched by changing the lasing polarization of the VCSEL.

Dielectric waveguide with transverse index variation that support a zero group velocity mode at a non-zero longitudinal wavevector

DOEpatents

Ibanescu, Mihai; Joannopoious, John D.; Fink, Yoel; Johnson, Steven G.; Fan, Shanhui

2005-06-21

Optical components including a laser based on a dielectric waveguide extending along a waveguide axis and having a refractive index cross-section perpendicular to the waveguide axis, the refractive index cross-section supporting an electromagnetic mode having a zero group velocity for a non-zero wavevector along the waveguide axis.

Surface-enhanced Raman scattering of amorphous silica gel adsorbed on gold substrates for optical fiber sensors

NASA Astrophysics Data System (ADS)

Degioanni, S.; Jurdyc, A. M.; Cheap, A.; Champagnon, B.; Bessueille, F.; Coulm, J.; Bois, L.; Vouagner, D.

2015-10-01

Two kinds of gold substrates are used to produce surface-enhanced Raman scattering (SERS) of amorphous silica obtained via the sol-gel route using tetraethoxysilane Si(OC2H5)4 (TEOS) solution. The first substrate consists of a gold nanometric film elaborated on a glass slide by sputter deposition, controlling the desired gold thickness and sputtering current intensity. The second substrate consists of an array of micrometer-sized gold inverted pyramidal pits able to confine surface plasmon (SP) enhancing electric field, which results in a distribution of electromagnetic energy inside the cavities. These substrates are optically characterized to observe SPR with, respectively, extinction and reflectance spectrometries. Once coated with thin layers of amorphous silica (SiO2) gel, these samples show Raman amplification of amorphous SiO2 bands. This enhancement can occur in SERS sensors using amorphous SiO2 gel as shells, spacers, protective coatings, or waveguides, and represents particularly a potential interest in the field of Raman distributed sensors, which use the amorphous SiO2 core of optical fibers as a transducer to make temperature measurements.

System and method for ultrafast optical signal detecting via a synchronously coupled anamorphic light pulse encoded laterally

DOEpatents

Heebner, John E [Livermore, CA

2010-08-03

In one general embodiment, a method for ultrafast optical signal detecting is provided. In operation, a first optical input signal is propagated through a first wave guiding layer of a waveguide. Additionally, a second optical input signal is propagated through a second wave guiding layer of the waveguide. Furthermore, an optical control signal is applied to a top of the waveguide, the optical control signal being oriented diagonally relative to the top of the waveguide such that the application is used to influence at least a portion of the first optical input signal propagating through the first wave guiding layer of the waveguide. In addition, the first and the second optical input signals output from the waveguide are combined. Further, the combined optical signals output from the waveguide are detected. In another general embodiment, a system for ultrafast optical signal recording is provided comprising a waveguide including a plurality of wave guiding layers, an optical control source positioned to propagate an optical control signal towards the waveguide in a diagonal orientation relative to a top of the waveguide, at least one optical input source positioned to input an optical input signal into at least a first and a second wave guiding layer of the waveguide, and a detector for detecting at least one interference pattern output from the waveguide, where at least one of the interference patterns results from a combination of the optical input signals input into the first and the second wave guiding layer. Furthermore, propagation of the optical control signal is used to influence at least a portion of the optical input signal propagating through the first wave guiding layer of the waveguide.

FIBER AND INTEGRATED OPTICS: Optimization of optical film waveguides

NASA Astrophysics Data System (ADS)

Adamson, P. V.

1990-10-01

Theoretical investigations were made of the possibility of optimization of the effective thickness, of the optical confinement factor Γ1, and of the birefringence of a planar dielectric waveguide as a function of the waveguide parameter V and the waveguide asymmetry. For a given value of V it is possible to ensure higher values of Γ1, for an asymmetric waveguide than for a symmetric one. An approximate expression is proposed for the factor Γ1, of an asymmetric waveguide directly in terms of its thickness and the refractive indices of the layers.

The superfamily keeps growing: Identification in trypanosomatids of RibJ, the first riboflavin transporter family in protists.

PubMed

Balcazar, Darío E; Vanrell, María Cristina; Romano, Patricia S; Pereira, Claudio A; Goldbaum, Fernando A; Bonomi, Hernán R; Carrillo, Carolina

2017-04-01

Trypanosomatid parasites represent a major health issue affecting hundreds of million people worldwide, with clinical treatments that are partially effective and/or very toxic. They are responsible for serious human and plant diseases including Trypanosoma cruzi (Chagas disease), Trypanosoma brucei (Sleeping sickness), Leishmania spp. (Leishmaniasis), and Phytomonas spp. (phytoparasites). Both, animals and trypanosomatids lack the biosynthetic riboflavin (vitamin B2) pathway, the vital precursor of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) cofactors. While metazoans obtain riboflavin from the diet through RFVT/SLC52 transporters, the riboflavin transport mechanisms in trypanosomatids still remain unknown. Here, we show that riboflavin is imported with high affinity in Trypanosoma cruzi, Trypanosoma brucei, Leishmania (Leishmania) mexicana, Crithidia fasciculata and Phytomonas Jma using radiolabeled riboflavin transport assays. The vitamin is incorporated through a saturable carrier-mediated process. Effective competitive uptake occurs with riboflavin analogs roseoflavin, lumiflavin and lumichrome, and co-factor derivatives FMN and FAD. Moreover, important biological processes evaluated in T. cruzi (i.e. proliferation, metacyclogenesis and amastigote replication) are dependent on riboflavin availability. In addition, the riboflavin competitive analogs were found to interfere with parasite physiology on riboflavin-dependent processes. By means of bioinformatics analyses we identified a novel family of riboflavin transporters (RibJ) in trypanosomatids. Two RibJ members, TcRibJ and TbRibJ from T. cruzi and T. brucei respectively, were functionally characterized using homologous and/or heterologous expression systems. The RibJ family represents the first riboflavin transporters found in protists and the third eukaryotic family known to date. The essentiality of riboflavin for trypanosomatids, and the structural/biochemical differences that RFVT/SLC52 and RibJ present, make the riboflavin transporter -and its downstream metabolism- a potential trypanocidal drug target.

Surveyed opinion of American trauma, orthopedic, and thoracic surgeons on rib and sternal fracture repair.

PubMed

Mayberry, John C; Ham, L Bruce; Schipper, Paul H; Ellis, Thomas J; Mullins, Richard J

2009-03-01

Rib and sternal fracture repair are controversial. The opinion of surgeons regarding those patients who would benefit from repair is unknown. Members of the Eastern Association for the Surgery of Trauma, the Orthopedic Trauma Association, and thoracic surgeons (THS) affiliated with teaching hospitals in the United States were recruited to complete an electronic survey regarding rib and sternal fracture repair. Two hundred thirty-eight trauma surgeons (TRS), 97 orthopedic trauma surgeons (OTS), and 70 THS completed the survey. Eighty-two percent of TRS, 66% of OTS, and 71% of THS thought that rib fracture repair was indicated in selected patients. A greater proportion of surgeons thought that sternal fracture repair was indicated in selected patients (89% of TRS, 85% of OTS, and 95% of THS). Chest wall defect/pulmonary hernia (58%) and sternal fracture nonunion (>6 weeks) (68%) were the only two indications accepted by a majority of respondents. Twenty-six percent of surgeons reported that they had performed or assisted on a chest wall fracture repair, whereas 22% of surgeons were familiar with published randomized trials of the surgical repair of flail chest. Of surgeons who thought rib fracture or sternal fracture repair was rarely, if ever, indicated, 91% and 95%, respectively, specified that a randomized trial confirming efficacy would be necessary to change their negative opinion. A majority of surveyed surgeons reported that rib and sternal fracture repair is indicated in selected patients; however, a much smaller proportion indicated that they had performed the procedures. The published literature on surgical repair is sparse and unfamiliar to most surgeons. Barriers to surgical repair of rib and sternal fracture include a lack of expertise among TRS, lack of research of optimal techniques, and a dearth of randomized trials.

Influence of mesh density, cortical thickness and material properties on human rib fracture prediction.

PubMed

Li, Zuoping; Kindig, Matthew W; Subit, Damien; Kent, Richard W

2010-11-01

The purpose of this paper was to investigate the sensitivity of the structural responses and bone fractures of the ribs to mesh density, cortical thickness, and material properties so as to provide guidelines for the development of finite element (FE) thorax models used in impact biomechanics. Subject-specific FE models of the second, fourth, sixth and tenth ribs were developed to reproduce dynamic failure experiments. Sensitivity studies were then conducted to quantify the effects of variations in mesh density, cortical thickness, and material parameters on the model-predicted reaction force-displacement relationship, cortical strains, and bone fracture locations for all four ribs. Overall, it was demonstrated that rib FE models consisting of 2000-3000 trabecular hexahedral elements (weighted element length 2-3mm) and associated quadrilateral cortical shell elements with variable thickness more closely predicted the rib structural responses and bone fracture force-failure displacement relationships observed in the experiments (except the fracture locations), compared to models with constant cortical thickness. Further increases in mesh density increased computational cost but did not markedly improve model predictions. A ±30% change in the major material parameters of cortical bone lead to a -16.7 to 33.3% change in fracture displacement and -22.5 to +19.1% change in the fracture force. The results in this study suggest that human rib structural responses can be modeled in an accurate and computationally efficient way using (a) a coarse mesh of 2000-3000 solid elements, (b) cortical shells elements with variable thickness distribution and (c) a rate-dependent elastic-plastic material model. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

The superfamily keeps growing: Identification in trypanosomatids of RibJ, the first riboflavin transporter family in protists

PubMed Central

Balcazar, Darío E.; Vanrell, María Cristina; Romano, Patricia S.; Pereira, Claudio A.; Goldbaum, Fernando A.; Bonomi, Hernán R.; Carrillo, Carolina

2017-01-01

Background Trypanosomatid parasites represent a major health issue affecting hundreds of million people worldwide, with clinical treatments that are partially effective and/or very toxic. They are responsible for serious human and plant diseases including Trypanosoma cruzi (Chagas disease), Trypanosoma brucei (Sleeping sickness), Leishmania spp. (Leishmaniasis), and Phytomonas spp. (phytoparasites). Both, animals and trypanosomatids lack the biosynthetic riboflavin (vitamin B2) pathway, the vital precursor of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) cofactors. While metazoans obtain riboflavin from the diet through RFVT/SLC52 transporters, the riboflavin transport mechanisms in trypanosomatids still remain unknown. Methodology/Principal findings Here, we show that riboflavin is imported with high affinity in Trypanosoma cruzi, Trypanosoma brucei, Leishmania (Leishmania) mexicana, Crithidia fasciculata and Phytomonas Jma using radiolabeled riboflavin transport assays. The vitamin is incorporated through a saturable carrier-mediated process. Effective competitive uptake occurs with riboflavin analogs roseoflavin, lumiflavin and lumichrome, and co-factor derivatives FMN and FAD. Moreover, important biological processes evaluated in T. cruzi (i.e. proliferation, metacyclogenesis and amastigote replication) are dependent on riboflavin availability. In addition, the riboflavin competitive analogs were found to interfere with parasite physiology on riboflavin-dependent processes. By means of bioinformatics analyses we identified a novel family of riboflavin transporters (RibJ) in trypanosomatids. Two RibJ members, TcRibJ and TbRibJ from T. cruzi and T. brucei respectively, were functionally characterized using homologous and/or heterologous expression systems. Conclusions/Significance The RibJ family represents the first riboflavin transporters found in protists and the third eukaryotic family known to date. The essentiality of riboflavin for trypanosomatids, and the structural/biochemical differences that RFVT/SLC52 and RibJ present, make the riboflavin transporter -and its downstream metabolism- a potential trypanocidal drug target. PMID:28406895

Tissue engineering rib with the incorporation of biodegradable polymer cage and BMSCs/decalcified bone: an experimental study in a canine model.

PubMed

Tang, Hua; Wu, Bin; Qin, Xiong; Zhang, Lu; Kretlow, Jim; Xu, Zhifei

2013-05-20

The reconstruction of large bone defects, including rib defects, remains a challenge for surgeons. In this study, we used biodegradable polydioxanone (PDO) cages to tissue engineer ribs for the reconstruction of 4cm-long costal defects. PDO sutures were used to weave 6cm long and 1cm diameter cages. Demineralized bone matrix (DBM) which is a xenograft was molded into cuboids and seeded with second passage bone marrow mesenchymal stem cells (BMSCs) that had been osteogenically induced. Two DBM cuboids seeded with BMSCs were put into the PDO cage and used to reconstruct the costal defects. Radiographic examination including 3D reconstruction, histologic examination and mechanical test was performed after 24 postoperative weeks. All the experimental subjects survived. In all groups, the PDO cage had completely degraded after 24 weeks and been replaced by fibrous tissue. Better shape and radian were achieved in PDO cages filled with DBM and BMSCs than in the other two groups (cages alone, or cages filled with acellular DBM cuboids). When the repaired ribs were subjected to an outer force, the ribs in the PDO cage/DBMs/BMSCs group kept their original shape while ribs in the other two groups deformed. In the PDO cage/DBMs/BMSCs groups, we also observed bony union at all the construct interfaces while there was no bony union observed in the other two groups. This result was also confirmed by radiographic and histologic examination. This study demonstrates that biodegradable PDO cage in combination with two short BMSCs/DBM cuboids can repair large rib defects. The satisfactory repair rate suggests that this might be a feasible approach for large bone repair.

Tissue engineering rib with the incorporation of biodegradable polymer cage and BMSCs/decalcified bone: an experimental study in a canine model

PubMed Central

2013-01-01

Background The reconstruction of large bone defects, including rib defects, remains a challenge for surgeons. In this study, we used biodegradable polydioxanone (PDO) cages to tissue engineer ribs for the reconstruction of 4cm-long costal defects. Methods PDO sutures were used to weave 6cm long and 1cm diameter cages. Demineralized bone matrix (DBM) which is a xenograft was molded into cuboids and seeded with second passage bone marrow mesenchymal stem cells (BMSCs) that had been osteogenically induced. Two DBM cuboids seeded with BMSCs were put into the PDO cage and used to reconstruct the costal defects. Radiographic examination including 3D reconstruction, histologic examination and mechanical test was performed after 24 postoperative weeks. Results All the experimental subjects survived. In all groups, the PDO cage had completely degraded after 24 weeks and been replaced by fibrous tissue. Better shape and radian were achieved in PDO cages filled with DBM and BMSCs than in the other two groups (cages alone, or cages filled with acellular DBM cuboids). When the repaired ribs were subjected to an outer force, the ribs in the PDO cage/DBMs/BMSCs group kept their original shape while ribs in the other two groups deformed. In the PDO cage/DBMs/BMSCs groups, we also observed bony union at all the construct interfaces while there was no bony union observed in the other two groups. This result was also confirmed by radiographic and histologic examination. Conclusions This study demonstrates that biodegradable PDO cage in combination with two short BMSCs/DBM cuboids can repair large rib defects. The satisfactory repair rate suggests that this might be a feasible approach for large bone repair. PMID:23688344

Pulsed ultrasounds accelerate healing of rib fractures in an experimental animal model: an effective new thoracic therapy?

PubMed

Santana-Rodríguez, Norberto; Clavo, Bernardino; Fernández-Pérez, Leandro; Rivero, José C; Travieso, María M; Fiuza, María D; Villar, Jesús; García-Castellano, José M; Hernández-Pérez, Octavio; Déniz, Antonio

2011-05-01

Rib fractures are a frequent traumatic injury associated with a relatively high morbidity. Currently, the treatment of rib fractures is symptomatic. Since it has been reported that pulsed ultrasounds accelerates repair of limb fractures, we hypothesized that the application of pulsed ultrasounds will modify the course of healing in an animal model of rib fracture. We studied 136 male Sprague-Dawley rats. Animals were randomly assigned to different groups of doses (none, 50, 100, and 250 mW/cm(2) of intensity for 3 minutes per day) and durations (2, 10, 20, and 28 days) of treatment with pulsed ultrasounds. In every subgroup, we analyzed radiologic and histologic changes in the bone callus. In addition, we examined changes in gene expression of relevant genes involved in wound repair in both control and treated animals. Histologic and radiologic consolidation was significantly increased by pulsed ultrasound treatment when applied for more than 10 days. The application of 50 mW/cm(2) was the most effective dose. Only the 100 and 250 mW/cm(2) doses were able to significantly increase messenger RNA expression of insulin-like growth factor 1, suppressor of cytokine signaling-2 and -3, and vascular endothelial growth factor and decrease monocyte chemoattractant protein-1 and collagen type II-alpha 1. Our findings indicate that pulsed ultrasound accelerates the consolidation of rib fractures. This study is the first to show that pulsed ultrasound promotes the healing of rib fractures. From a translational point of view, this easy, cheap technique could serve as an effective new therapeutic modality in patients with rib fractures. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Biomechanical investigation of impact induced rib fractures of a porcine infant surrogate model.

PubMed

Blackburne, William B; Waddell, J Neil; Swain, Michael V; Alves de Sousa, Ricardo J; Kieser, Jules A

2016-09-01

This study investigated the structural, biomechanical and fractographic features of rib fractures in a piglet model, to test the hypothesis that fist impact, apart from thoracic squeezing, may result in lateral costal fractures as observed in abused infants. A mechanical fist with an accelerometer was constructed and fixed to a custom jig. Twenty stillborn piglets in the supine position were impacted on the thoracic cage. The resultant force versus time curves from the accelerometer data showed a number of steps indicative of rib fracture. The correlation between impact force and number of fractures was statistically significant (Pearson׳s r=0.528). Of the fractures visualized, 15 completely pierced the parietal pleura of the thoracic wall, and 5 had butterfly fracture patterning. Scanning electron microscopy showed complete bone fractures, at the zone of impact, were normal to the axis of the ribs. Incomplete vertical fractures, with bifurcation, occurred on the periphery of the contact zone. This work suggests the mechanism of rib failure during a fist impact is typical of the transverse fracture pattern in the anterolateral region associated with cases of non-accidental rib injury. The impact events investigated have a velocity of ~2-3m/s, approximately 2×10(4) times faster than previous quasi-static axial and bending tests. While squeezing the infantile may induce buckle fractures in the anterior as well as posterior region of the highly flexible bones, a fist punch impact event may result in anterolateral transverse fractures. Hence, these findings suggest that the presence of anterolateral rib fractures may result from impact rather than manual compression. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of efficacy and indications of surgical fixation for multiple rib fractures: a propensity-score matched analysis.

PubMed

Uchida, K; Nishimura, T; Takesada, H; Morioka, T; Hagawa, N; Yamamoto, T; Kaga, S; Terada, T; Shinyama, N; Yamamoto, H; Mizobata, Y

2017-08-01

The purpose of this study was to assess the effects of recent surgical rib fixation and establish its indications not only for flail chest but also for multiple rib fractures. Between 2007 and 2015, 187 patients were diagnosed as having multiple rib fractures in our institution. After the propensity score matching was performed, ten patients who had performed surgical rib fixation and ten patients who had treated with non-operative management were included. Categorical variables were analyzed with Fischer's exact test and non-parametric numerical data were compared using the Mann-Whitney U test. Wilcoxon signed-rank test was performed for comparison of pre- and postoperative variables. All statistical data are presented as median (25-75 % interquartile range [IQR]) or number. The surgically treated patients extubated significantly earlier than non-operative management patients (5.5 [1-8] vs 9 [7-12] days: p = 0.019). The duration of continuous intravenous narcotic agents infusion days (4.5 [3-6] vs 12 [9-14] days: p = 0.002) and the duration of intensive care unit stay (6.5 [3-9] vs 12 [8-14] days: p = 0.008) were also significantly shorter in surgically treated patients. Under the same ventilating conditions, the postoperative values of tidal volume and respiratory rate improved significantly compared to those values measured just before the surgery. The incidence of pneumonia as a complication was significantly higher in non-operative management group (p = 0.05). From the viewpoints of early respiratory stabilization and intensive care unit disposition without any complications, surgical rib fixation is a sufficiently acceptable procedure not only for flail chest but also for repair of severe multiple rib fractures.

Follow-up bone scan in breast cancer patients: what is the appropriate interpretation of purely rib uptake?

PubMed

Seo, Minjung; Ko, Byung Kyun; Tae, Soon Young; Koh, Su-Jin; Noh, Young Ju; Choi, Hye-Jeong; Bae, Kyungkyg; Bang, Minseo; Jun, Sungmin; Park, Seol Hoon

2016-12-01

Although rib uptake is frequently detected in follow-up bone scans of breast cancer patients, few studies have assessed its clinical significance. Among 1208 breast cancer patients who underwent a bone scan between 2011 and 2014, 157 patients presented with newly detected rib uptake at follow-up. Patients who had underlying bone metastases (n=8) or had simultaneous new uptake in sites other than the rib (n=13) were excluded. The patients enrolled finally were those who had purely rib uptakes. The location, intensity, and final diagnosis of the uptake were evaluated by nuclear medicine physicians. A total of 275 new instances of rib uptake were detected in follow-up bone scans of 136 patients. These were more frequently located on the ipsilateral side of the breast cancer (61.1%) and the anterior arc (65.1%), and they presented as moderate to intense (93.1%) uptakes. Among these, 265 lesions in 130 patients turned out to be benign fractures (96.4%), whereas only 10 lesions in six patients were metastases. The proportion of metastases was significantly higher if the uptake was linear or if the patient had recurrence. It was marginally higher if the uptake was located in the posterior arc. The proportion of metastases within the radiation field was significantly lower in patients with a history of irradiation. Newly detected purely rib uptake on a follow-up bone scan in patients who have been treated for breast cancer is mostly because of fractures and rarely signals metastasis. However, if the patient has disease recurrence, metastasis should strongly be suspected, particularly when uptake is linear or located in the posterior arc.

Pain as an indication for rib fixation: a bi-institutional pilot study.

PubMed

de Moya, Marc; Bramos, Thanos; Agarwal, Suresh; Fikry, Karim; Janjua, Sumbal; King, David R; Alam, Hasan B; Velmahos, George C; Burke, Peter; Tobler, William

2011-12-01

In trauma patients, open reduction and internal fixation of rib fractures remain controversial. We hypothesized that patients who have open reduction and internal fixation of rib fractures would experience less pain compared with controls and thus require fewer opiates. Further, we hypothesized that improved pain control would result in fewer pulmonary complications and decreased length of stay. This is a retrospective bi-institutional matched case-control study. Cases were matched 1:2 by age, injury severity Score, chest abbreviated injury severity score, head abbreviated injury severity score, pulmonary contusion score, and number of fractured ribs. The daily total doses of analgesic drugs were converted to equianalgesic intravenous morphine doses, and the primary outcome was inpatient narcotic administration. Sixteen patients between July 2005 and June 2009 underwent rib fixation in 5 ± 3 days after injury using an average of 3 (1-5) metallic plates. Morphine requirements decreased from 110 mg ± 98 mg preoperatively to 63 ± 57 mg postoperatively (p = 0.01). There were no significant differences between cases and controls in the mean morphine dose (79 ± 63 vs. 76 ± 55 mg, p = 0.65), hospital stay (18 ± 12 vs. 16 ± 11 days, p = 0.67), intensive care unit stay (9 ± 8 vs. 7 ± 10 days, p = 0.75), ventilation days (7 ± 8 vs. 6 ± 10, p = 0.44), and pneumonia rates (31% vs. 38%, p = 0.76). The need for analgesia was significantly reduced after rib fixation in patients with multiple rib fractures. However, no difference in outcomes was observed when these patients were compared with matched controls in this pilot study. Further study is required to investigate these preliminary findings.

Operative fixation of rib fractures after blunt trauma: A practice management guideline from the Eastern Association for the Surgery of Trauma.

PubMed

Kasotakis, George; Hasenboehler, Erik A; Streib, Erik W; Patel, Nimitt; Patel, Mayur B; Alarcon, Louis; Bosarge, Patrick L; Love, Joseph; Haut, Elliott R; Como, John J

2017-03-01

Rib fractures are identified in 10% of all injury victims and are associated with significant morbidity (33%) and mortality (12%). Significant progress has been made in the management of rib fractures over the past few decades, including operative reduction and internal fixation (rib ORIF); however, the subset of patients that would benefit most from this procedure remains ill-defined. The aim of this project was to develop evidence-based recommendations. Population, intervention, comparison, and outcome (PICO) questions were formulated for patients with and without flail chest. Outcomes of interest included mortality, duration of mechanical ventilation (DMV), hospital and intensive care unit (ICU) length of stay (LOS), incidence of pneumonia, need for tracheostomy, and pain control. A systematic review and meta-analysis of currently available evidence was performed per the Grading of Recommendations Assessment, Development, and Evaluation methodology. Twenty-two studies were identified and analyzed. These included 986 patients with flail chest, of whom 334 underwent rib ORIF. Rib ORIF afforded lower mortality; shorter DMV, hospital LOS, and ICU LOS; and lower incidence of pneumonia and need for tracheostomy. The data quality was deemed very low, with only three prospective randomized trials available. Analyses for pain in patients with flail chest and all outcomes in patients with nonflail chest were not feasible due to inadequate data. In adult patients with flail chest, we conditionally recommend rib ORIF to decrease mortality; shorten DMV, hospital LOS, and ICU LOS; and decrease incidence of pneumonia and need for tracheostomy. We cannot offer a recommendation for pain control, or any of the outcomes in patients with nonflail chest with currently available data. Systematic review/meta-analysis, level III.

Atypical form of melorheostosis improved by pamidronate.

PubMed

Saadallaoui Ben Hamida, Kaouther; Ksontini, Imen; Rahali, Hajer; Mourali, Slim; Fejraoui, Nadia; Bouhaouala, Habib; Charfi, M Ridha; Dougui, M Hedi

2009-03-01

Melorheostosis is a rare chronic bone disease of unknown etiology that often affects a single limb. Report a new case of melorheostosis of the ribs improved by pamidronate infusions A 36-year-old man without any medical history was admitted for a history of one month painful tumefaction on the 7th left rib. The diagnosis of melorheostosis of the rib and the tibia was made. Patient was treated by pamidronate infusions with useful and satisfactory outcome.

Mechanical strength of multicomponent reinforced composite structures at different temperatures

NASA Astrophysics Data System (ADS)

Chumaevskii, A. V.; Rubtsov, V. E.; Kolubae, E. A.; Tarasov, S. Yu.; Filippov, A. V.

2017-12-01

The paper studies mechanical properties and fractography of composite structure components after tensile testing at 20, +120 and -120°C. Both tensile strength and elasticity modulus of composite samples were shown to be independent of stress concentrators in the form of ribs. On the contrary, the tensile test at high and low temperatures had notable detrimental effect of mechanical characteristics of the samples with ribs as compared to those of the rib-free samples.

The 'Pro-Drug' RibCys Decreases The Mutagenicity of High LET Radiation in Cultured Mammalian Cells

NASA Technical Reports Server (NTRS)

Lenarczyk, M.; Ueno, A.; Vannais, D. B.; Kraemer, S.; Kronenberg, A.; Roberts, J. C.; Tatsumi, K.; Hei, T. K.; Waldren, C. A.

2000-01-01

We have initiated studies aimed at reducing the mutational effects of high LET radiation such as Fe-56 ions and C-12 ions with certain drugs. The mutagenicity of high LET (143 keV/micrometer) Fe-56 or C-12 ions (LET = 100 keV/micrometer) was quantified at the CD59 locus of human-hamster hybrid AL cells. RibCys [2,S)-D-ribo-(1',2',3',4'- Tetrahydroxybutyl)-thiazolidine-4(R)-ca riboxylic acid], formed by condensation of L-cysteine with D-ribose, is designed so that the sulfhydryl amino acid L-cysteine is released intracellularly via nonenzymatic ring opening and hydrolysis leading to increased levels of glutathione (GSH). RibCys (4 or 10 mM), present during irradiation and a few hours post-irradiation, significantly decreased the yield of CD59(-) mutants induced by radiation. RibCys did not affect the clonogenic survival of irradiated cells, nor was it mutagenic itself. These results, together with the minimal side effects reported in mice and pigs, indicate that RibCys may be useful, perhaps even when used prophylactically, in reducing the load of mutations created by high LET radiation in astronauts or other exposed individuals. RibCys is an attractive drug that may reduce the risk of carcinogenesis in people exposed to high LET radiation.

Dynamic simulations of under-rib convection-driven flow-field configurations and comparison with experiment in polymer electrolyte membrane fuel cells

NASA Astrophysics Data System (ADS)

Duy, Vinh Nguyen; Lee, Jungkoo; Kim, Kyungcheol; Ahn, Jiwoong; Park, Seongho; Kim, Taeeun; Kim, Hyung-Man

2015-10-01

The under-rib convection-driven flow-field design for the uniform distribution of reacting gas and the generation of produced water generates broad scientific interest, especially among those who study the performance of polymer electrolyte membrane fuel cells (PEMFCs). In this study, we simulate the effects of an under-rib convection-driven serpentine flow-field with sub-channel and by-pass (SFFSB) and a conventional advanced serpentine flow-field (CASFF) on single cell performance, and we compare the simulation results with experimental measurements. In the under-rib convection-driven flow-field configuration with SFFSB, the pressure drop is decreased because of the greater cross-sectional area for gas flow, and the decreased pressure drop results in the reduction of the parasitic loss. The anode liquid water mass fraction increases with increasing channel height because of increased back diffusion, while the cathode liquid water mass fraction does not depend upon the sub-channels but is ascribed mainly to the electro-osmotic drag. Simulation results verify that the maximum current and the power densities of the SFFSB are increased by 18.85% and 23.74%, respectively, due to the promotion of under-rib convection. The findings in this work may enable the optimization of the design of under-rib convection-driven flow-fields for efficient PEMFCs.

Reconstruction of Extensive Soft-Tissue Defects with Concomitant Bone Defects in the Lower Extremity with the Latissimus Dorsi-Serratus Anterior-Rib Free Flap.

PubMed

Sia, Wei Tee; Xu, Germaine Guiqin; Puhaindran, Mark Edward; Tan, Bien Keem; Cheng, Mathew Hern Wang; Chew, Winston Yoon Chong

2015-07-01

The combined latissimus dorsi-serratus anterior-rib (LD-SA-rib) free flap provides a large soft-tissue flap with a vascularized bone flap through a solitary vascular pedicle in a one-stage reconstruction. Seven LD-SA-rib free flaps were performed in seven patients to reconstruct concomitant bone and extensive soft-tissue defects in the lower extremity (tibia, five; femur, one; foot, one). The patients were all male, with an average age of 34 years (range, 20-48 years). These defects were secondary to trauma in five patients and posttraumatic osteomyelitis in two patients. All flaps survived and achieved bony union. The average time to bony union was 9.4 months. Bone hypertrophy of at least 20% occurred in all flaps. All patients achieved full weight-bearing ambulation without aid at an average duration of 23.7 months. Two patients developed stress fractures of the rib flap. There was no significant donor site morbidity, except for two patients who had pleural tears during harvesting of the flap. The LD-SA-rib flap provides a large soft-tissue component and a vascularized bone flap for reconstruction of composite large soft-tissue defects with concomitant bone defects of the lower extremity in a one-stage procedure. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

[Rib cage ostheosynthesis. Literature review and case reports].

PubMed

Jiménez-Quijano, Andrés; Varón-Cotés, Juan Carlos; García-Herreros-Hellal, Luis Gerardo; Espinosa-Moya, Beatriz; Rivero-Rapalino, Oscar; Salazar-Marulanda, Michelle

2015-01-01

Fractures of the chest wall include sternum and rib fractures. Traditionally they are managed conservatively due to the anatomy of the rib cage that allows most of them to remain stable and to form a callus that unites the fractured segments. In spite of this management, some patients present with chronic pain or instability of the wall which makes them require some type of fixation. The present article performs a literature review based on 4 cases. The first case was a 61 year-old man with blunt chest trauma, with a great deformity of the chest wall associated with subcutaneous emphysema, and pneumothorax. The second case was a 51 year-old man with blunt chest trauma, initially managed at another institution, who despite treatment, had persistent pain and dyspnoea. The third case was a 30 year-old man that suffered a motor vehicle accident, with resulting pain and crepitation of the rib cage and with diagnostic images showing multiple rib fractures. The last case is a 62 year-old man that fell down the stairs, with blunt chest trauma with high intensity pain, dyspnoea and basal ipsilateral hypoventilation. Rib fracture fixation offers a good alternative in selected patients to decrease associated morbidity, leading to a patient's fast return to his or her working life. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

Early intravenous ibuprofen decreases narcotic requirement and length of stay after traumatic rib fracture.

PubMed

Bayouth, Lilly; Safcsak, Karen; Cheatham, Michael L; Smith, Chadwick P; Birrer, Kara L; Promes, John T

2013-11-01

Pain control after traumatic rib fracture is essential to avoid respiratory complications and prolonged hospitalization. Narcotics are commonly used, but adjunctive medications such as nonsteroidal anti-inflammatory drugs may be beneficial. Twenty-one patients with traumatic rib fractures treated with both narcotics and intravenous ibuprofen (IVIb) (Treatment) were retrospectively compared with 21 age- and rib fracture-matched patients who received narcotics alone (Control). Pain medication requirements over the first 7 hospital days were evaluated. Mean daily IVIb dose was 2070 ± 880 mg. Daily intravenous morphine-equivalent requirement was 19 ± 16 vs 32 ± 24 mg (P < 0.0001). Daily narcotic requirement was significantly decreased in the Treatment group on Days 3 through 7 (P < 0.05). Total weekly narcotic requirement was significantly less among Treatment patients (P = 0.004). Highest and lowest daily pain scores were lower in the Treatment group (P < 0.05). Hospital length of stay was 4.4 ± 3.4 versus 5.4 ± 2.9 days (P = 0.32). There were no significant complications associated with IVIb therapy. Early IVIb therapy in patients with traumatic rib fractures significantly decreases narcotic requirement and results in clinically significant decreases in hospital length of stay. IVIb therapy should be initiated in patients with traumatic rib fractures to improve patient comfort and reduce narcotic requirement.

High incidence of cervical ribs indicates vulnerable condition in Late Pleistocene woolly rhinoceroses

PubMed Central

2017-01-01

Mammals as a rule have seven cervical vertebrae, a number that remains remarkably constant. Changes of this number are associated with major congenital abnormalities (pleiotropic effects) that are, at least in humans, strongly selected against. Recently, it was found that Late Pleistocene mammoths (Mammuthus primigenius) from the North Sea have an unusually high incidence of abnormal cervical vertebral numbers, approximately ten times higher than that of extant elephants. Abnormal numbers were due to the presence of large cervical ribs on the seventh vertebra, indicating a homeotic change from a cervical rib-less vertebra into a thoracic rib-bearing vertebra. The high incidence of cervical ribs indicates a vulnerable condition and is thought to be due to inbreeding and adverse conditions that may have impacted early pregnancies in declining populations. In this study we investigated the incidence of cervical ribs in another extinct Late Pleistocene megaherbivore from the North Sea and the Netherlands, the woolly rhinoceros (Coelodonta antiquitatis). We show that the incidence of abnormal cervical vertebral numbers in the woolly rhinoceros is unusually high for mammals (15,6%, n = 32) and much higher than in extant Rhinoceratidae (0%, n = 56). This indicates that woolly rhinoceros lived under vulnerable conditions, just like woolly mammoths. The vulnerable condition may well have contributed to their eventual extinction. PMID:28875067

Method for ultrafast optical deflection enabling optical recording via serrated or graded light illumination

DOEpatents

Heebner, John E [Livermore, CA

2009-09-08

In one general embodiment, a method for deflecting an optical signal input into a waveguide is provided. In operation, an optical input signal is propagated through a waveguide. Additionally, an optical control signal is applied to a mask positioned relative to the waveguide such that the application of the optical control signal to the mask is used to influence the optical input signal propagating in the waveguide. Furthermore, the deflected optical input signal output from the waveguide is detected in parallel on an array of detectors. In another general embodiment, a beam deflecting structure is provided for deflecting an optical signal input into a waveguide, the structure comprising at least one wave guiding layer for guiding an optical input signal and at least one masking layer including a pattern configured to influence characteristics of a material of the guiding layer when an optical control signal is passed through the masking layer in a direction of the guiding layer. In another general embodiment, a system is provided including a waveguide, an attenuating mask positioned on the waveguide, and an optical control source positioned to propagate pulsed laser light towards the attenuating mask and the waveguide such that a pattern of the attenuating mask is applied to the waveguide and material properties of at least a portion of the waveguide are influenced.

FDTD simulation of amorphous silicon waveguides for microphotonics applications

NASA Astrophysics Data System (ADS)

Fantoni, A.; Lourenço, P.; Pinho, P.; Vieira, M.,

2017-05-01

In this work we correlate the dimension of the waveguide with small variations of the refractive index of the material used for the waveguide core. We calculate the effective modal refractive index for different dimensions of the waveguide and with slightly variation of the refractive index of the core material. These results are used as an input for a set of Finite Difference Time Domain simulation, directed to study the characteristics of amorphous silicon waveguides embedded in a SiO2 cladding. The study considers simple linear waveguides with rectangular section for studying the modal attenuation expected at different wavelengths. Transmission efficiency is determined analyzing the decay of the light power along the waveguides. As far as near infrared wavelengths are considered, a-Si:H shows a behavior highly dependent on the light wavelength and its extinction coefficient rapidly increases as operating frequency goes into visible spectrum range. The simulation results show that amorphous silicon can be considered a good candidate for waveguide material core whenever the waveguide length is as short as a few centimeters. The maximum transmission length is highly affected by the a-Si:H defect density, the mid-gap density of states and by the waveguide section area. The simulation results address a minimum requirement of 300nm×400nm waveguide section in order to keep attenuation below 1 dB cm-1.