Forsterite Shock Temperatures and Entropy: New Scaling Laws for Impact Melting and Vaporization

Science.gov (United States)

Davies, E.; Root, S.; Kraus, R. G.; Townsend, J. P.; Spaulding, D.; Stewart, S. T.; Jacobsen, S. B.; Fratanduono, D.; Millot, M. A.; Mattsson, T. R.; Hanshaw, H. L.

2017-12-01

The observed masses, radii and temperatures of thousands of extra-solar planets have challenged our theoretical understanding of planet formation and planetary structures. Planetary materials are subject to extreme pressures and temperatures during formation and within the present-day interiors of large bodies. Here, we focus on improving understanding of the physical properties of rocky planets for calculations of internal structure and the outcomes of giant impacts. We performed flyer plate impact experiments on forsterite [Mg2SiO4] on the Z-Machine at Sandia National Laboratory and decaying shock temperature measurements at the Omega EP laser at U. Rochester. At Z, planar, supported shock waves are generated in single crystal samples, permitting observation of both compressed and released states. Using available static and dynamic thermodynamic data, we calculate absolute entropy and heat capacity along the forsterite shock Hugoniot. Entropy and heat capacity on the Hugoniot are larger than previous estimates. Our data constrain the thermodynamic properties of forsterite liquid at high pressures and temperatures and the amount of melt and vapor produced during impact events. For an ambient pressure of 1 bar, shock-vaporization begins upon reaching the liquid region on the forsterite Hugoniot (about 200 GPa). Using hydrocode simulations of giant impacts between rocky planets with forsterite mantles and iron cores and the new experimentally-constrained forsterite shock entropy, we present a new scaling law for the fraction of mantle that is melted or vaporized by the initial shock wave. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525. Prepared by LLNL under Contract DE-AC52-07NA27344. Prepared by the Center

Impulsive shock induced single drop steam explosion visualized by high-speed x-ray radiography and photography - metallic melt

International Nuclear Information System (INIS)

Park, H. S.; Hansson, R. C.; Sehgal, B. R.

2003-01-01

Experimental investigation of fine fragmentation process during vapor explosion was conducted in a small-scale single drop system employing continuous high-speed X-ray radiography and photography. A molten tin drop of about 0.7 g at approximately 1000 .deg. C was dropped into a water pool, at temperatures ranging from 20 to 90 .deg. C, and the explosion was triggered by an external shock pulse of about 1 MPa. X-ray radiographs show that finely fragmented melt particles accelerates to the vapor bubble boundary and forms a particle shell during the period of vapor bubble expansion due to vapor explosions. From the photographs, it was possible to observe a number of counter-jets on the vapor boundary. For tests with highly subcooled coolant, local explosion due to external impulsive shock trigger initiates the stratified mode of explosion along the entire melt surface. For tests with lower subcooled coolant local explosions were initiated by an external impulsive shock trigger and by collapse of vapor/gas pocket attached on the top of the melt drop. Transient spatial distribution map of melt fragments during vapor explosion was obtained by a series of image processing and calibration tests

Shock compression behavior of bi-material powder composites with disparate melting temperatures

International Nuclear Information System (INIS)

Sullivan, Kyle T.; Swift, Damian; Barham, Matthew; Stölken, James; Kuntz, Joshua; Kumar, Mukul

2014-01-01

Laser driven experiments were used to investigate the shock compression behavior of powder processed Bismuth/Tungsten (Bi/W) composite samples. The constituents provide different functionality to the composite behavior as Bi could be shock melted at the pressures attained in this work, while the W could not. Samples were prepared by uniaxial pressing, and the relative density was measured as a function of particle size, applied pressure, and composition for both hot and cold pressing conditions. This resulted in sample densities between 73% and 99% of the theoretical maximum density, and also noticeable differences in microstructure in the hot and cold pressed samples. The compression waves were generated with a 1.3 × 1.3 mm square spot directly onto the surface of the sample, using irradiances between 10 12 and 10 13  W/cm 2 , which resulted in calculated peak pressures between 50 and 150 GPa within a few micrometers. Sample recovery and post-mortem analysis revealed the formation of a crater on the laser drive surface, and the depth of this crater corresponded to the depth to which the Bi had been melted. The melt depth was found to be primarily a function of residual porosity and composition, and ranged from 167 to 528 μm. In general, a higher porosity led to a larger melt depth. Direct numerical simulations were performed, and indicated that the observed increase in melt depth for low-porosity samples could be largely attributed to increased heating associated with work done for pore collapse. However, the relative scaling was sensitive to composition, with low volume fraction Bi samples exhibiting a much stronger dependence on porosity than high Bi content samples. Select samples were repeated using an Al foil ablator, but there were no noticeable differences ensuring that the observed melting was indeed pressure-driven and was not a result of direct laser heating. The resultant microstructures and damage near the spall surface were also investigated

Shock Melting of Iron Silicide as Determined by In Situ X-ray Diffraction.

Science.gov (United States)

Newman, M.; Kraus, R. G.; Wicks, J. K.; Smith, R.; Duffy, T. S.

2016-12-01

The equation of state of core alloys at pressures and temperatures near the solid-liquid coexistence curve is important for understanding the dynamics at the inner core boundary of the Earth and super-Earths. Here, we present a series of laser driven shock experiments on textured polycrystalline Fe-15Si. These experiments were conducted at the Omega and Omega EP laser facilities. Particle velocities in the Fe-15Si samples were measured using a line VISAR and were used to infer the thermodynamic state of the shocked samples. In situ x-ray diffraction measurements were used to probe the melting transition and investigate the potential decomposition of Fe-15Si in to hcp and B2 structures. This work examines the kinetic effects of decomposition due to the short time scale of dynamic compression experiments. In addition, the thermodynamic data collected in these experiments adds to a limited body of information regarding the equation of state of Fe-15Si, which is a candidate for the composition in Earth's outer core. Our experimental results show a highly textured solid phase upon shock compression to pressures ranging from 170 to 300 GPa. Below 320 GPa, we observe diffraction peaks consistent with decomposition of the D03 starting material in to an hcp and a cubic (potentially B2) structure. Upon shock compression above 320 GPa, the intense and textured solid diffraction peaks give way to diffuse scattering and loss of texture, consistent with melting along the Hugoniot. When comparing these results to that of pure iron, we can ascertain that addition of 15 wt% silicon increases the equilibrium melting temperature significantly, or that the addition of silicon significantly increases the metastability of the solid phase, relative to the liquid. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

Science.gov (United States)

Fat'yanov, O. V.; Asimow, P. D.

2014-05-01

Continuing our effort to obtain experimental constraints on the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. Our new Mo capsule design holds a long MgO crystal in a controlled thermal gradient until impact by a Ta flyer launched at up to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel VIS/NIR pyrometer with 3 ns time resolution. The majority of our experiments showed smooth monotonic increases in MgO sound speed and shock temperature with pressure from 197 to 243 GPa. The measured temperatures as well as the slopes of the pressure dependences for both temperature and sound speed were in good agreement with those calculated numerically for the solid phase at our peak shock compression conditions. Most observed sound speeds, however, were ~800 m/s higher than those predicted by the model. A single unconfirmed data point at 239 GPa showed anomalously low temperature and sound speed, which could both be explained by partial melting in this experiment and could suggest that the Hugoniot of MgO preheated to 2300 K crosses its melting line just slightly above 240 GPa.

MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

International Nuclear Information System (INIS)

Fat'yanov, O V; Asimow, P D

2014-01-01

Continuing our effort to obtain experimental constraints on the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. Our new Mo capsule design holds a long MgO crystal in a controlled thermal gradient until impact by a Ta flyer launched at up to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel VIS/NIR pyrometer with 3 ns time resolution. The majority of our experiments showed smooth monotonic increases in MgO sound speed and shock temperature with pressure from 197 to 243 GPa. The measured temperatures as well as the slopes of the pressure dependences for both temperature and sound speed were in good agreement with those calculated numerically for the solid phase at our peak shock compression conditions. Most observed sound speeds, however, were ∼800 m/s higher than those predicted by the model. A single unconfirmed data point at 239 GPa showed anomalously low temperature and sound speed, which could both be explained by partial melting in this experiment and could suggest that the Hugoniot of MgO preheated to 2300 K crosses its melting line just slightly above 240 GPa.

High-pressure polymorphs in Yamato-790729 L6 chondrite and their significance for collisional conditions

Science.gov (United States)

Kato, Yukako; Sekine, Toshimori; Kayama, Masahiko; Miyahara, Masaaki; Yamaguchi, Akira

2017-12-01

Shock pressure recorded in Yamato (Y)-790729, classified as L6 type ordinary chondrite, was evaluated based on high-pressure polymorph assemblages and cathodoluminescence (CL) spectra of maskelynite. The host-rock of Y-790729 consists mainly of olivine, low-Ca pyroxene, plagioclase, metallic Fe-Ni, and iron-sulfide with minor amounts of phosphate and chromite. A shock-melt vein was observed in the hostrock. Ringwoodite, majorite, akimotoite, lingunite, tuite, and xieite occurred in and around the shock-melt vein. The shock pressure in the shock-melt vein is about 14-23 GPa based on the phase equilibrium diagrams of high-pressure polymorphs. Some plagioclase portions in the host-rock occurred as maskelynite. Sixteen different CL spectra of maskelynite portions were deconvolved using three assigned emission components (centered at 2.95, 3.26, and 3.88 eV). The intensity of emission component at 2.95 eV was selected as a calibrated barometer to estimate shock pressure, and the results indicate pressures of about 11-19 GPa. The difference in pressure between the shock-melt vein and host-rock might suggest heterogeneous shock conditions. Assuming an average shock pressure of 18 GPa, the impact velocity of the parent-body of Y-790729 is calculated to be 1.90 km s-1. The parent-body would be at least 10 km in size based on the incoherent formation mechanism of ringwoodite in Y-790729.

On high-pressure melting of tantalum

Science.gov (United States)

Luo, Sheng-Nian; Swift, Damian C.

2007-01-01

The issues related to high-pressure melting of Ta are discussed within the context of diamond-anvil cell (DAC) and shock wave experiments, theoretical calculations and common melting models. The discrepancies between the extrapolations of the DAC melting curve and the melting point inferred from shock wave experiments, cannot be reconciled either by superheating or solid-solid phase transition. The failure to reproduce low-pressure DAC melting curve by melting models such as dislocation-mediated melting and the Lindemann law, and molecular dynamics and quantum mechanics-based calculations, undermines their predictions at moderate and high pressures. Despite claims to the contrary, the melting curve of Ta (as well as Mo and W) remains inconclusive at high pressures.

Two-temperature hydrodynamic expansion and coupling of strong elastic shock with supersonic melting front produced by ultrashort laser pulse

International Nuclear Information System (INIS)

Inogamov, Nail A; Khokhlov, Viktor A; Zhakhovsky, Vasily V; Khishchenko, Konstantin V; Demaske, Brian J; Oleynik, Ivan I

2014-01-01

Ultrafast processes, including nonmonotonic expansion of material into vacuum, supersonic melting and generation of super-elastic shock wave, in a surface layer of metal irradiated by an ultrashort laser pulse are discussed. In addition to the well-established two-temperature (2T) evolution of heated layer a new effect of electron pressure gradient on early stage of material expansion is studied. It is shown that the expanding material experiences an unexpected jump in flow velocity in a place where stress exceeds the effective tensile strength provided by used EoS of material. Another 2T effect is that supersonic propagation of homogeneous melting front results in distortion of spatial profile of ion temperature, which later imprints on ion pressure profile transforming in a super-elastic shock wave with time.

Ultrafast studies of shock-induced melting and phase transitions at LCLS

Science.gov (United States)

McMahon, Malcolm

The study of shock-induced phase transitions, which is vital to the understanding of material response to rapid pressure changes, dates back to the 1950s, when Bankcroft et al reported a transition in iron. Since then, many transitions have been reported in a wide range of materials, but, due to the lack of sufficiently bright x-ray sources, the structural details of these new phases has been notably lacking. While the development of nanosecond in situ x-ray diffraction has meant that lattice-level studies of such phenomena have become possible, including studies of the phase transition reported 60 years ago in iron, the quality of the diffraction data from such studies is noticeably poorer than that obtained from statically-compressed samples on synchrotrons. The advent of x-ray free electron lasers (XFELs), such as the LCLS, has resulted in an unprecedented improvement in the quality of diffraction data that can be obtained from shock-compressed matter. Here I describe the results from three recent experiment at the LCLS that looked at the solid-solid and solid-liquid phase transitions in Sb, Bi and Sc using single 50 fs x-ray exposures. The results provide new insight into the structural changes and melting induced by shock compression. This work is supported by EPSRC under Grant No. EP/J017051/1. Use of the LCLS, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515.

Measurement of Preheat and Shock Melting in Be Ablators During the First Few ns of the NIF Ignition Pulse

Energy Technology Data Exchange (ETDEWEB)

Bradley, D K; Prisbrey, S T; Page, R H; Braun, D G; Edwards, M J; Hibbard, R L; Moreno, K A; Mauldin, M P; Nikroo, A

2008-05-28

We have developed a scaled hohlraum platform to experimentally measure preheat in ablator materials during the first few nanoseconds of the radiation drive proposed for ignition experiments at the National Ignition Facility [J. A. Paisner, J. D. Boyes, S. A. Kumpan, et al., Laser Focus World 30, 75 (1994)]. The platform design approximates the radiation environment of the pole of the capsule by matching both the laser spot intensity and illuminated hohlraum wall fraction in scaled halfraums driven by the OMEGA laser system [T. R. Boehly, D. L. Brown, R. S. Craxton, et al., Optics Communications 133, 495 (1997)]. A VISAR reflecting from the rear surface of the sample was used to measure sample motion prior to shock breakout. The experiments show that the first {approx}20 {micro}m of a Be ablator will be melted by radiation preheat, with subsequent material melted by the initial shock, in agreement with simulations. The experiments also show no evidence of anomalous heating of buried high-z doped layers in the ablator.

Comparative Study on Two Melting Simulation Methods: Melting Curve of Gold

International Nuclear Information System (INIS)

Liu Zhong-Li; Li Rui; Sun Jun-Sheng; Zhang Xiu-Lu; Cai Ling-Cang

2016-01-01

Melting simulation methods are of crucial importance to determining melting temperature of materials efficiently. A high-efficiency melting simulation method saves much simulation time and computational resources. To compare the efficiency of our newly developed shock melting (SM) method with that of the well-established two-phase (TP) method, we calculate the high-pressure melting curve of Au using the two methods based on the optimally selected interatomic potentials. Although we only use 640 atoms to determine the melting temperature of Au in the SM method, the resulting melting curve accords very well with the results from the TP method using much more atoms. Thus, this shows that a much smaller system size in SM method can still achieve a fully converged melting curve compared with the TP method, implying the robustness and efficiency of the SM method. (paper)

Characterization of frictional melting processes in subduction zone faults by trace element and isotope analyses

Science.gov (United States)

Ishikawa, T.; Ujiie, K.

2017-12-01

Pseudotachylytes found in exhumed accretionary complexes, which are considered to be formed originally at seismogenic depths, are of great importance for elucidating frictional melting and concomitant dynamic weakening of the fault during earthquake in subduction zones. However, fluid-rich environment of the subduction zone faults tends to cause extensive alteration of the pseudotachylyte glass matrix in later stages, and thus it has been controversial that pseudotachylytes are rarely formed or rarely preserved. Chemical analysis of the fault rocks, especially on fluid-immobile trace elements and isotopes, can be a useful means to identify and quantify the frictional melting occurred in subduction zone faults. In this paper, we report major and trace element and Sr isotope compositions for pseudotachylyte-bearing dark veins and surrounding host rocks from the Mugi area of the Shimanto accretionary complex (Ujiie et al., J. Struct. Geol. 2007). Samples were collected from a rock chip along the microstructure using a micro-drilling technique, and then analyzed by ICP-MS and TIMS. Major element compositions of the dark veins showed a clear shift from the host rock composition toward the illite composition. The dark veins, either unaltered or completely altered, were also characterized by extreme enrichment in some of the trace elements such as Ti, Zr, Nb and Th. These results are consistent with disequilibrium melting of the fault zone. Model calculations revealed that the compositions of the dark veins can be produced by total melting of clay-rich matrix in the source rock, leaving plagioclase and quartz grains almost unmolten. The calculations also showed that the dark veins are far more enriched in melt component than that expected from the source rock compositions, suggesting migration and concentration of frictional melt during the earthquake faulting. Furthermore, Sr isotope data of the dark veins implied the occurrence of frictional melting in multiple stages

Chondrule destruction in nebular shocks

Energy Technology Data Exchange (ETDEWEB)

Jacquet, Emmanuel; Thompson, Christopher, E-mail: ejacquet@mnhn.fr [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St George Street, Toronto, ON M5S 3H8 (Canada)

2014-12-10

Chondrules are millimeter-sized silicate spherules ubiquitous in primitive meteorites, but whose origin remains mysterious. One of the main proposed mechanisms for producing them is melting of solids in shock waves in the gaseous protoplanetary disk. However, evidence is mounting that chondrule-forming regions were enriched in solids well above solar abundances. Given the high velocities involved in shock models, destructive collisions would be expected between differently sized grains after passage of the shock front as a result of differential drag. We investigate the probability and outcome of collisions of particles behind a one-dimensional shock using analytic methods as well as a full integration of the coupled mass, momentum, energy, and radiation equations. Destruction of protochondrules seems unavoidable for solid/gas ratios ε ≳ 0.1, and possibly even for solar abundances because of 'sandblasting' by finer dust. A flow with ε ≳ 10 requires much smaller shock velocities (∼2 versus 8 km s{sup –1}) in order to achieve chondrule-melting temperatures, and radiation trapping allows slow cooling of the shocked fragments. Initial destruction would still be extensive; although re-assembly of millimeter-sized particles would naturally occur by grain sticking afterward, the compositional heterogeneity of chondrules may be difficult to reproduce. We finally note that solids passing through small-scale bow shocks around few kilometer-sized planetesimals might experience partial melting and yet escape fragmentation.

Theoretical study of melting curves on Ta, Mo, and W at high pressures

Energy Technology Data Exchange (ETDEWEB)

Xi Feng [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, 621900 Mianyang (China)], E-mail: hawk_0816@yahoo.com.cn; Cai Lingcang [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, 621900 Mianyang (China)

2008-06-01

The melting curves of tantalum (Ta), molybdenum (Mo), and tungsten (W) are calculated using a dislocation-mediated melting model. The calculated melting curves are in good agreement with shock-wave data, and partially in agreement with wire explosion and piston-cylinder data, but show large discrepancies with diamond-anvil cell (DAC) data. We propose that the melting mechanism caused by shock-wave and laser-heated DAC techniques are probably different, and that a systematic difference exists in the two melting processes.

MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

OpenAIRE

Fat'yanov, Oleg V.; Asimow, P. D.

2014-01-01

Continuing our effort to obtain experimental constraints on the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. Our new Mo capsule design holds a long MgO crystal in a controlled thermal gradient until impact by a Ta flyer launched at up to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel VIS/NIR pyrometer with 3 ns time resolution. The majority ...

Microjetting from a grooved Al surface under supported and unsupported shocks

Science.gov (United States)

Shao, Jian-Li; Wang, Pei; He, An-Min

2014-08-01

Using molecular dynamics methods, we simulate and compare the microjetting from a grooved Al surface induced by supported and unsupported shocks at different breakout pressures. Via the analysis on the microjetting morphologies and mass distributions, we find that the threshold of shock breakout pressure for the microjetting formation is almost same, but the variation of microjet mass with shock pressure shows a great difference for the two loading patterns. Under supported shock loading, the microjet mass keeps a continuous increase with increasing shock pressure, and release melting can enhance it markedly. By contrast, the microjet mass under unsupported shocks is smaller and seems no remarkable increase with shock pressure in our simulations (at extremely short pulses), implying the shock decaying can weaken the microjetting. Of course, a large area of fragments near the surface may form in this case. The microjet source distributions corresponding to supported and unsupported shocks are presented. It is found that the former becomes apparently broader than the latter with increasing shock pressure. Besides, the microjet tip velocity under supported shocks may appear a reduction because of the material strength effect below release melting. While under unsupported shocks, all the microjets in solid and melted states will experience the reduction of tip velocity. These decrements of tip velocity can be fitted by an exponential function.

Endovascular stenting of the obstructed vertical vein in a neonate with supracardiac total anomalous pulmonary venous return

Directory of Open Access Journals (Sweden)

Nageswara R Koneti

2012-01-01

Full Text Available A newborn baby presented with respiratory distress, cyanosis and shock within 2 hours of birth. The cardiac evaluation showed supracardiac total anomalous pulmonary venous return with critically obstructed vertical vein. The baby underwent successful stenting of the vertical vein at 12 hours of life.

Silicate Veining Above an Ascending Mantle Plume - Evidence from New Ethiopian Xenolith Localities

Science.gov (United States)

Rooney, T. O.; Furman, T.; Ayalew, D.; Yirgu, G.

2004-12-01

Quaternary basaltic eruptions in the Debre Zeyit (Bishoftu) and Butajira regions of the Main Ethiopian Rift host Al-augite, norite and rare lherzolite xenoliths, xenocrysts and megacrysts. These explosive basaltic eruptions are located 20 km to the west of the main rift axis and are characterized by cinder cones and maars. The host basalt was generated as a small degree partial melt of fertile peridotite between 15 and 25 kb and host abundant Al-augite (Type II) xenoliths derived from pressures up to 10 kb. The central Main Ethiopian Rift lies in a transitional zone between the continental rifting of East Africa and the sea floor spreading associated with the Red Sea. Lithospheric and sub-lithospheric processes that occur during the transition from continental to oceanic magmatism may be investigated using these xenolith-bearing basalts. Neither carbonatitic nor hydrous (amphibole + phlogopite) metasomatism is evident in either the xenoliths or host basalts, suggesting that infiltration of silicate melts that produced Al-augite veining dominates the regional lower crust and lithospheric mantle. These veins are significantly hotter (200 - 300 ° C) than the lherzolite wall rock they intrude suggesting the thermal influence of the Afar plume. Recent geophysical tomography indicates that this veining is pervasive and segmented, supporting the association of these Al-augite veins with the formation of a proto-ridge axis. Al-augite xenoliths and megacrysts have been observed in other continental rift settings such as Durango (Luhr, 2001) and Lake Baikal (Litasov, 2000), indicating Al-augite silicate melt metasomatism is a fundamental process associated with continental rift development.

Chondritic Meteorites: Nebular and Parent-Body Formation Processes

Science.gov (United States)

Rubin, Alan E.; Lindstrom, David (Technical Monitor)

2002-01-01

It is important to identify features in chondrites that formed as a result of parent-body modification in order to disentangle nebular and asteroidal processes. However, this task is difficult because unmetamorphosed chondritic meteorites are mixtures of diverse components including various types of chondrules, chondrule fragments, refractory and mafic inclusions, metal-sulfide grains and fine-grained matrix material. Shocked chondrites can contain melt pockets, silicate-darkened material, metal veins, silicate melt veins, and impact-melt-rock clasts. This grant paid for several studies that went far in helping to distinguish primitive nebular features from those produced during asteroidal modification processes.

Melting along the Hugoniot and solid phase transition for Sn via sound velocity measurements

Science.gov (United States)

Song, Ping; Cai, Ling-cang; Tao, Tian-jiong; Yuan, Shuai; Chen, Hong; Huang, Jin; Zhao, Xin-wen; Wang, Xue-jun

2016-11-01

It is very important to determine the phase boundaries for materials with complex crystalline phase structures to construct their corresponding multi-phase equation of state. By measuring the sound velocity of Sn with different porosities, different shock-induced melting pressures along the solid-liquid phase boundary could be obtained. The incipient shock-induced melting of porous Sn samples with two different porosities occurred at a pressure of about 49.1 GPa for a porosity of 1.01 and 45.6 GPa for a porosity of 1.02, based on measurements of the sound velocity. The incipient shock-induced melting pressure of solid Sn was revised to 58.1 GPa using supplemental measurements of the sound velocity. Trivially, pores in Sn decreased the shock-induced melting pressure. Based on the measured longitudinal sound velocity data, a refined solid phase transition and the Hugoniot temperature-pressure curve's trend are discussed. No bcc phase transition occurs along the Hugoniot for porous Sn; further investigation is required to understand the implications of this finding.

Use of IR pyrometry to measure free-surface temperatures of partially melted tin as a function of shock pressure

International Nuclear Information System (INIS)

Seifter, A.; Furlanetto, M. R.; Holtkamp, D. B.; Obst, A. W.; Payton, J. R.; Stone, J. B.; Tabaka, L. J.; Grover, M.; Macrum, G. S.; Stevens, G. D.; Turley, W. D.; Swift, D. C.; Veeser, L. R.

2009-01-01

Equilibrium equation of state theory predicts that the free-surface release temperature of shock-loaded tin will show a plateau at 505 K in the stress range from 19.5 to 33.0 GPa, corresponding to the solid-liquid, mixed-phase region of tin. In this paper we report free-surface temperature measurements on shock-loaded tin from 15 to 31 GPa using multiwavelength optical pyrometry. The shock waves were generated by direct contact of detonating high explosive with a tin sample, and the stress in the sample was determined by free-surface velocity measurements using photon Doppler velocimetry. We measured the emitted thermal radiance in the near IR region at four wavelengths from 1.5 to 5.0 μm. Above 25 GPa the measured free-surface temperatures were higher than the predicted 505 K, and they increased with increasing stress. This deviation may be explained by hot spots and/or variations in surface emissivity, and it may indicate a weakness in the use of a simple analysis of multiwavelength pyrometry data for conditions, such as above the melt threshold, where hot spots or emissivity variations may be significant. We are continuing to study the discrepancy to determine its cause.

The Cocos Ridge hydrothermal system revealed by microthermometry of fluid and melt inclusions

Science.gov (United States)

Brandstätter, J.; Kurz, W.; Krenn, K.

2017-12-01

Microthermometric analyses of fluid and melt inclusions in hydrothermal veins and in the Cocos Ridge (CCR) basalt were used to reveal the CCR thermal history at IODP Site 344-U1414 and to constrain fluid source and flow. Hydrothermal veins are hosted by lithified sediments and CCR basalt . Site 344-U1414, located 1 km seaward of the Middle American Trench offshore Costa Rica, serves to evaluate fluid/rock interaction, the hydrologic system and geochemical processes linked with the tectonic evolution of the incoming Cocos Plate from the Early Miocene up to recent times. The veins in the sedimentary rocks are mainly filled by blocky calcite, containing numerous fluid inclusions, and sometimes crosscut fibrous quartz/chalcedony veins. The veins in the basalt can be differentiated into three types: antitaxial fibrous calcite veins, composite veins with fibrous calcite and clay minerals at the vein margins and spherulitic quartz in the center, and syntaxial blocky aragonite veins surrounded by a clay selvage in the uppermost CCR basalt sections. Secondary minerals, clay minerals, fibrous calcite, quartz/chalcedony and pyrite also filled vesicles in the basalt. Fluid inclusions were mainly found in the aragonite veins and rarely in quartz in the composite veins and vesicles. Blocky veins with embedded wall rock fragments appear in the sediments and in the basalt indicate hydraulic fracturing. The occurrence of decrepitated fluid inclusions show high homogenization temperatures up to 400 °C. Decrepitated fluid inclusions are formed by increased internal overpressure, related to isobaric heating. Elongated fluid inclusion planes, arc-like fluid inclusions and low homogenization temperatures indicate subsequent isobaric cooling. The results obtained so far from Raman spectroscopy and microthermometry indicate CO2 inclusions and petrographic observations suggest the presence of silicate melt inclusions in phenocrysts in the basalt (mainly in clinopyroxene and plagioclase

Sclerotherapy of Varicose Veins and Spider Veins

Science.gov (United States)

... Index A-Z Sclerotherapy of Varicose Veins and Spider Veins Sclerotherapy uses injections from a very fine, ... Sclerotherapy? What is Sclerotherapy of Varicose Veins and Spider Veins? Sclerotherapy is a minimally invasive treatment used ...

Magnetic Fields Recorded by Chondrules Formed in Nebular Shocks

Science.gov (United States)

Mai, Chuhong; Desch, Steven J.; Boley, Aaron C.; Weiss, Benjamin P.

2018-04-01

Recent laboratory efforts have constrained the remanent magnetizations of chondrules and the magnetic field strengths to which the chondrules were exposed as they cooled below their Curie points. An outstanding question is whether the inferred paleofields represent the background magnetic field of the solar nebula or were unique to the chondrule-forming environment. We investigate the amplification of the magnetic field above background values for two proposed chondrule formation mechanisms, large-scale nebular shocks and planetary bow shocks. Behind large-scale shocks, the magnetic field parallel to the shock front is amplified by factors of ∼10–30, regardless of the magnetic diffusivity. Therefore, chondrules melted in these shocks probably recorded an amplified magnetic field. Behind planetary bow shocks, the field amplification is sensitive to the magnetic diffusivity. We compute the gas properties behind a bow shock around a 3000 km radius planetary embryo, with and without atmospheres, using hydrodynamics models. We calculate the ionization state of the hot, shocked gas, including thermionic emission from dust, thermal ionization of gas-phase potassium atoms, and the magnetic diffusivity due to Ohmic dissipation and ambipolar diffusion. We find that the diffusivity is sufficiently large that magnetic fields have already relaxed to background values in the shock downstream where chondrules acquire magnetizations, and that these locations are sufficiently far from the planetary embryos that chondrules should not have recorded a significant putative dynamo field generated on these bodies. We conclude that, if melted in planetary bow shocks, chondrules probably recorded the background nebular field.

Pelvic Vein Embolisation in the Management of Varicose Veins

International Nuclear Information System (INIS)

Ratnam, Lakshmi A.; Marsh, Petra; Holdstock, Judy M.; Harrison, Charmaine S.; Hussain, Fuad F.; Whiteley, Mark S.; Lopez, Anthony

2008-01-01

Pelvic vein incompetence is common in patients with atypical varicose veins, contributing to their recurrence after surgery. Therefore, refluxing pelvic veins should be identified and treated. We present our experience with pelvic vein embolisation in patients presenting with varicose veins. Patients presenting with varicose veins with a duplex-proven contribution from perivulval veins undergo transvaginal duplex sonography (TVUS) to identify refluxing pelvic veins. Those with positive scans undergo embolisation before surgical treatment of their lower limb varicose veins. A total of 218 women (mean age of 46.3 years) were treated. Parity was documented in the first 60 patients, of whom 47 (78.3%) were multiparous, 11 (18.3%) had had one previous pregnancy, and 2 (3.3%) were nulliparous. The left ovarian vein was embolised in 78%, the right internal iliac in 64.7%, the left internal iliac in 56.4%, and the right ovarian vein in 42.2% of patients. At follow-up TVUS, mild reflux only was seen in 16, marked persistent reflux in 6, and new reflux in 3 patients. These 9 women underwent successful repeat embolisation. Two patients experienced pulmonary embolisation of the coils, of whom 1 was asymptomatic and 1 was successfully retrieved; 1 patient had a misplaced coil protruding into the common femoral vein; and 1 patient had perineal thrombophlebitis. The results of our study showed that pelvic venous embolisation by way of a transjugular approach is a safe and effective technique in the treatment of pelvic vein reflux.

[Invasion of the portal vein by a hydatid cyst. Review of the literature].

Science.gov (United States)

Zubiaurre Lizarralde, Leire; Oyarzabal Pérez, Igor; Ruiz Montesinos, Inmaculada; Guisasola Gorrotxategi, Esther

2006-01-01

We have found only 3 publications in the literature that describe portal vein invasion by a hydatid cyst. This complication is very uncommon but should be kept in mind in the diagnosis of anaphylactic shock. Clinical presentation can vary from abdominal pain and fever to portal hypertension or anaphylactic reaction due to leaking of antigenic material from the cyst. Ultrasound and computed tomography scan can identify hydatid cysts and cavernomatosis, but magnetic resonance imaging shows the presence of multiple daughter vesicles replacing the lumen of the portal vein and a communication between the residual cyst and the portal vein. The treatment of choice is surgery, including removal of the cyst and local instillation of scolicide solution. In addition to surgery, administration of albendazole is recommended. Administration should begin 4 days before extirpation and should be continued for more than 4 weeks.

Conservative Management of Azygous Vein Rupture in Blunt Thoracic Trauma

Directory of Open Access Journals (Sweden)

Cian McDermott

2012-01-01

Full Text Available We report a case of successful conservative management of acute traumatic rupture of the azygous vein. A 48-year-old male was involved in a motor vehicle collision. Primary survey revealed acute right intrathoracic haemorrhage. He remained haemodynamically stable with rapid infusion of warmed crystalloid solution and blood. Computed tomographic imaging showed a contained haematoma of the azygous vein. The patient was managed conservatively in the intensive care. Azygous vein laceration resulting from blunt thoracic trauma is a rare condition that carries a universally poor prognosis unless the appropriate treatment is instituted. Clinical features include acute hypovolaemic shock, widened mediastinum on chest radiograph, and a right-sided haemothorax. Haemodynamic collapse necessitates immediate resuscitative thoracotomy. Interest in this injury stems from the severity of the clinical condition, difficulty in diagnosis, the onset of a rapidly deteriorating clinical course all of which can be promptly reversed by timely and appropriate treatment. Although it is a rare cause of intramediastinal haemorrhage, it is proposed that a ruptured azygous vein should be considered in every trauma case causing a right-sided haemothorax or widened mediastinum. All cases described in the literature to date involved operative management. We present a case of successful conservative management of this condition.

Shock-induced decomposition of a high density glass (ZF6)

Science.gov (United States)

Zhou, Xianming; Liu, Xun; Li, Jiabo; Li, Jun; Cao, Xiuxia

2011-07-01

The dynamic high-pressure behavior of a high density glass (ZF6) was investigated in this study. The Hugoniot data, shock temperature (TH) and release sound velocity (C) of ZF6 were measured by a time-resolved multi-channel pyrometer in the shock pressure (PH) range of 50-170 GPa. The Hugoniot data is in accord with the Los Alamos Scientific Laboratory (LASL) shock Hugoniot data and shows a good linearity over 21 GPa. Polymorphic phase transitions were identified by the kinks in the measured TH-PH and C-PH relationships. The onset pressures of the transformations are ˜75 and ˜128 GPa, respectively. A thermodynamic calculation suggests that the phase transition at 75 GPa is its disproportionation to massicot (high pressure phase of PbO) and melted silica while the transition at 128 GPa is from the melting of massicot.

Fluid fractionation of tungsten during granite-pegmatite differentiation and the metal source of peribatholitic W quartz veins: Evidence from the Karagwe-Ankole Belt (Rwanda)

Science.gov (United States)

Hulsbosch, Niels; Boiron, Marie-Christine; Dewaele, Stijn; Muchez, Philippe

2016-02-01

columbite-tantalite mineralised pegmatites of the Gatumba-Gitarama area, emphasises the efficiency of fluid saturation to extract crystal-melt incompatible tungsten from the differentiating melt phase. Fluid-melt-crystal partitioning calculations support the concept of a magmatic-hydrothermal fluid source for tungsten and constrain the range of permissible crystal-melt and fluid-melt partition coefficients together with realistic values for water solubility in the parental G4 granitic melt. Consequently, we propose that for highly-differentiated B-rich, F-poor granite systems fluid saturation started prior to or at the granite-pegmatite transition stage resulting in apical to peribatholitic tungsten veins systems that are paragenetically older than the final pegmatite stage.

Power law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions

Energy Technology Data Exchange (ETDEWEB)

Durand, O.; Soulard, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

2013-11-21

Large scale molecular dynamics (MD) simulations are performed to study and to model the ejecta production from the dynamic fragmentation of shock-loaded metals under melt conditions. A generic 3D crystal in contact with vacuum containing about 10{sup 8} atoms and with a sinusoidal free surface roughness is shock loaded so as to undergo a solid-liquid phase change on shock. The reflection of the shock wave at the interface metal/vacuum gives rise to the ejection of 2D jets/sheets of atoms (Richtmyer-Meshkov instabilities in the continuum limit), which develop and break up, forming ejecta (fragments) of different volumes (or mass). The fragmentation process is investigated by analyzing the evolution of the resulting volume distribution of the ejecta as a function of time. Two metals are studied (Cu and Sn) and the amplitude of the roughness is varied. The simulations show that the associated distributions exhibit a generic behavior with the sum of two distinct terms of varying weight, following the expansion rate of the jets: in the small size limit, the distribution obeys a power law dependence with an exponent equal to 1.15 ± 0.08; and in the large size limit, it obeys an exponential form. These two components are interpreted, with the help of additional simple simulations, as the signature of two different basic mechanisms of fragmentation. The power law dependence results from the fragmentation of a 2D network of ligaments arranged following a fractal (scale free) geometry and generated when the sheets of liquid metal expand and tear. The exponential distribution results from a 1D Poisson fragmentation process of the largest ligaments previously generated. Unlike the power law distribution, it is governed by a characteristic length scale, which may be provided by energy balance principle.

Power law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions

International Nuclear Information System (INIS)

Durand, O.; Soulard, L.

2013-01-01

Large scale molecular dynamics (MD) simulations are performed to study and to model the ejecta production from the dynamic fragmentation of shock-loaded metals under melt conditions. A generic 3D crystal in contact with vacuum containing about 10 8 atoms and with a sinusoidal free surface roughness is shock loaded so as to undergo a solid-liquid phase change on shock. The reflection of the shock wave at the interface metal/vacuum gives rise to the ejection of 2D jets/sheets of atoms (Richtmyer-Meshkov instabilities in the continuum limit), which develop and break up, forming ejecta (fragments) of different volumes (or mass). The fragmentation process is investigated by analyzing the evolution of the resulting volume distribution of the ejecta as a function of time. Two metals are studied (Cu and Sn) and the amplitude of the roughness is varied. The simulations show that the associated distributions exhibit a generic behavior with the sum of two distinct terms of varying weight, following the expansion rate of the jets: in the small size limit, the distribution obeys a power law dependence with an exponent equal to 1.15 ± 0.08; and in the large size limit, it obeys an exponential form. These two components are interpreted, with the help of additional simple simulations, as the signature of two different basic mechanisms of fragmentation. The power law dependence results from the fragmentation of a 2D network of ligaments arranged following a fractal (scale free) geometry and generated when the sheets of liquid metal expand and tear. The exponential distribution results from a 1D Poisson fragmentation process of the largest ligaments previously generated. Unlike the power law distribution, it is governed by a characteristic length scale, which may be provided by energy balance principle

Melting curve of materials: theory versus experiments

International Nuclear Information System (INIS)

Alfe, D; Vocadlo, L; Price, G D; Gillan, M J

2004-01-01

A number of melting curves of various materials have recently been measured experimentally and calculated theoretically, but the agreement between different groups is not always good. We discuss here some of the problems which may arise in both experiments and theory. We also report the melting curves of Fe and Al calculated recently using quantum mechanics techniques, based on density functional theory with generalized gradient approximations. For Al our results are in very good agreement with both low pressure diamond-anvil-cell experiments (Boehler and Ross 1997 Earth Planet. Sci. Lett. 153 223, Haenstroem and Lazor 2000 J. Alloys Compounds 305 209) and high pressure shock wave experiments (Shaner et al 1984 High Pressure in Science and Technology ed Homan et al (Amsterdam: North-Holland) p 137). For Fe our results agree with the shock wave experiments of Brown and McQueen (1986 J. Geophys. Res. 91 7485) and Nguyen and Holmes (2000 AIP Shock Compression of Condensed Matter 505 81) and the recent diamond-anvil-cell experiments of Shen et al (1998 Geophys. Res. Lett. 25 373). Our results are at variance with the recent calculations of Laio et al (2000 Science 287 1027) and, to a lesser extent, with the calculations of Belonoshko et al (2000 Phys. Rev. Lett. 84 3638). The reasons for these disagreements are discussed

Experimental study of dynamic fragmentation of shockloaded metals below and above melting

Directory of Open Access Journals (Sweden)

De Rességuier T.

2010-06-01

Full Text Available The breakout and reflection of a strong shock-wave upon the free surface of a metallic sample may lead to ejecta production of many types. Spall fracture is due to tensile stresses which result from the interaction of the incident and the reflected release waves. When the sample remains in solid state, one or several layers of finite thickness, called spalls, can be created and ejected. When melting is initiated during shock-wave propagation, tensile stresses are generated in a liquid medium and lead to the creation of an expanding cloud of liquid debris. This phenomenon, sometimes referred to as microspalling, consists in a dynamic fragmentation process in the melted material. The present paper is devoted to the experimental investigation of the transition from spall fracture in solid state to the micro-spalling process in molten metals. This study, realized on tin and on iron, involves different shock generators (gas gun, pulsed laser… and diagnostics (velocimetry, high-speed optical shadowgraphy, fragments recovery.

Premixing and steam explosion phenomena in the tests with stratified melt-coolant configuration and binary oxidic melt simulant materials

Energy Technology Data Exchange (ETDEWEB)

Kudinov, Pavel, E-mail: pavel@safety.sci.kth.se; Grishchenko, Dmitry, E-mail: dmitry@safety.sci.kth.se; Konovalenko, Alexander, E-mail: kono@kth.se; Karbojian, Aram, E-mail: karbojan@kth.se

2017-04-01

Highlights: • Steam explosion in stratified melt-coolant configuration is studied experimentally. • Different binary oxidic melt simulant materials were used. • Five spontaneous steam explosions were observed. • Instability of melt-coolant interface and formation of premixing layer was observed. • Explosion strength is influenced by melt superheat and water subcooling. - Abstract: Steam explosion phenomena in stratified melt-coolant configuration are considered in this paper. Liquid corium layer covered by water on top can be formed in severe accident scenarios with (i) vessel failure and release of corium melt into a relatively shallow water pool; (ii) with top flooding of corium melt layer. In previous assessments of potential energetics in stratified melt-coolant configuration, it was assumed that melt and coolant are separated by a stable vapor film and there is no premixing prior to the shock wave propagation. This assumption was instrumental for concluding that the amount of energy that can be released in such configuration is not of safety importance. However, several recent experiments carried out in Pouring and Under-water Liquid Melt Spreading (PULiMS) facility with up to 78 kg of binary oxidic corium simulants mixtures have resulted in spontaneous explosions with relatively high conversion ratios (order of one percent). The instability of the melt-coolant interface, melt splashes and formation of premixing layer were observed in the tests. In this work, we present results of experiments carried out more recently in steam explosion in stratified melt-coolant configuration (SES) facility in order to shed some light on the premixing phenomena and assess the influence of the test conditions on the steam explosion energetics.

Improved extraction of ePTFE and medical adhesive modified defibrillation leads from the coronary sinus and great cardiac vein.

Science.gov (United States)

Wilkoff, Bruce L; Belott, Peter H; Love, Charles J; Scheiner, Avram; Westlund, Randy; Rippy, Marian; Krishnan, Mohan; Norlander, Barry E; Steinhaus, Bruce; Emmanuel, Janson; Zeller, Peter J

2005-03-01

Permanent leads with shocking coils for defibrillation therapy are sometimes implanted in the coronary sinus (CS) and great cardiac vein (GCV). These shocking coils, as documented by pathologic examination of animal investigations, often become tightly encapsulated by fibrosis and can be very difficult to remove. One of three configurations of the Guidant model 7109 Perimeter coronary sinus shocking lead was implanted into the distal portion of the GCV of 24 sheep for up to 14 months. Group 1 had unmodified coils (control), group 2 had coils backfilled with medical adhesive (MA), and Group 3 had coils coated with expanded polytetrafluoroethylene (ePTFE). Eighteen leads, three from each group at 6 and 14 months were transvenously extracted from the left jugular vein. The remaining six animals were not subject to extraction. All animals were euthanized for pathological and microscopic examination. All six of the control, three of the MA, and one of the ePTFE leads required the use of an electrosurgical dissection sheath (EDS) for extraction. Five control, two MA, and none of the ePTFE leads had significant fibrotic attachments to the shocking coils. Significant trauma was observed at necropsy for those leads requiring the use of the EDS for extraction. Tissue ingrowth is a major impediment to the removal of defibrillation leads implanted in the CS and GCV of sheep. Reduction of tissue ingrowth by coating the shocking coils with ePTFE or by backfilling with MA facilitates transvenous lead removal with reduced tissue trauma.

Viscosity of aluminum under shock-loading conditions

International Nuclear Information System (INIS)

Ma Xiao-Juan; Liu Fu-Sheng; Zhang Ming-Jian; Sun Yan-Yun

2011-01-01

A reliable data treatment method is critical for viscosity measurements using the disturbance amplitude damping method of shock waves. In this paper the finite difference method is used to obtain the numerical solutions for the disturbance amplitude damping behaviour of the sinusoidal shock front in a flyer-impact experiment. The disturbance amplitude damping curves are used to depict the numerical solutions of viscous flow. By fitting the experimental data to the numerical solutions of different viscosities, we find that the effective shear viscosity coefficients of shocked aluminum at pressures of 42, 78 and 101 GPa are (1500±100) Pa·s, (2800±100) Pa·s and (3500±100) Pa·s respectively. It is clear that the shear viscosity of aluminum increases with an increase in shock pressure, so aluminum does not melt below a shock pressure of 101 GPa. This conclusion is consistent with the sound velocity measurement. (interdisciplinary physics and related areas of science and technology)

Varicose vein stripping

Science.gov (United States)

... stripping; Venous reflux - vein stripping; Venous ulcer - veins Patient Instructions Surgical wound care - open Varicose veins - what to ask your doctor Images Circulatory system References American Family Physician. Management of varicose veins. www.aafp.org/afp/2008/ ...

Shock Induced Melting in Aluminum: Wave Profile Measurements

Energy Technology Data Exchange (ETDEWEB)

Chhabildas, Lalit C.; Furnish, Michael D.; Reinhart, William D.

1999-06-23

We have developed launch capabilities that can propel macroscopic plates to hypervelocities (8 to 16 km/s). This capability has been used to determine the first time-resolved wave profile measurements using velocity interferometry techniques at impact velocities of 10 km/s. These measurements show that alu- minum continues to exhibit normal release behavior to 161 GPa with complete loss of strength in the shocked state. Results of these experiments are discussed and compared with the results of lower pressure experi- ments conducted at lower impact velocities.

Some techniques and results from high-pressure shock-wave experiments utilizing the radiation from shocked transparent materials

International Nuclear Information System (INIS)

McQueen, R.G.; Fritz, J.N.

1981-01-01

It has been known for many years that some transparent materials emit radiation when shocked to high pressures. This property was used to determine the temperature of shocked fused and crystal quartz, which in turn allowed the thermal expansion of SiO 2 at high pressure and also the specific heat to be calculated. Once the radiative energy as a function of pressure is known for one material it is shown how this can be used to determine the temperature of other transparent materials. By the nature of the experiments very accurate shock velocities can be measured and hence high quality equation of state data obtained. Some techniques and results are presented on measuring sound velocities from symmetrical impact of nontransparent materials using radiation emitting transparent analyzers, and on nonsymmetrical impact experiments on transparent materials. Because of special requirements in the later experiments, techniques were developed that lead to very high-precision shock-wave data. Preliminary results, using these techniques are presented for making estimates of the melting region and the yield strength of some metals under strong shock conditions

Molecular dynamics simulations of ejecta production from sinusoidal tin surfaces under supported and unsupported shocks

Science.gov (United States)

Wu, Bao; Wu, FengChao; Zhu, YinBo; Wang, Pei; He, AnMin; Wu, HengAn

2018-04-01

Micro-ejecta, an instability growth process, occurs at metal/vacuum or metal/gas interface when compressed shock wave releases from the free surface that contains surface defects. We present molecular dynamics (MD) simulations to investigate the ejecta production from tin surface shocked by supported and unsupported waves with pressures ranging from 8.5 to 60.8 GPa. It is found that the loading waveforms have little effect on spike velocity while remarkably affect the bubble velocity. The bubble velocity of unsupported shock loading remains nonzero constant value at late time as observed in experiments. Besides, the time evolution of ejected mass in the simulations is compared with the recently developed ejecta source model, indicating the suppressed ejection of unmelted or partial melted materials. Moreover, different reference positions are chosen to characterize the amount of ejecta under different loading waveforms. Compared with supported shock case, the ejected mass of unsupported shock case saturates at lower pressure. Through the analysis on unloading path, we find that the temperature of tin sample increases quickly from tensile stress state to zero pressure state, resulting in the melting of bulk tin under decaying shock. Thus, the unsupported wave loading exhibits a lower threshold pressure causing the solid-liquid phase transition on shock release than the supported shock loading.

Point-of-Care Ultrasonography to Assess Portal Vein Pulsatility and the Effect of Inhaled Milrinone and Epoprostenol in Severe Right Ventricular Failure: A Report of 2 Cases.

Science.gov (United States)

Tremblay, Jan-Alexis; Beaubien-Souligny, William; Elmi-Sarabi, Mahsa; Desjardins, Georges; Denault, André Y

2017-10-15

This article describes 2 patients with severe acute right ventricular failure causing circulatory shock. Portal vein pulsatility assessed by bedside ultrasonography suggested clinically relevant venous congestion. Management included cardiac preload reduction and combined inhalation of milrinone and epoprostenol to reduce right ventricular afterload. Portal vein ultrasonography may be useful in assessing right ventricular function in the acutely ill patient.

Portal Vein Thrombosis

Directory of Open Access Journals (Sweden)

Hakan Demirci

2016-01-01

Full Text Available Portal vein thrombosis is an important cause of presinusoidal portal hypertension. Portal vein thrombosis commonly occurs in patient with cirrhosis, malignancy and prothrombotic states. Patients with acute portal vein thrombosis have immediate onset. Patients with chronic portal vein thrombosis have developed portal hypertension and cavernous portal transformation. Portal vein thrombosis is diagnosed with doppler ultrasound, computed tomography and magnetic resonance imaging. Therapy with low molecular weight heparin achieves recanalization in more than half of acute cases.

Collateral veins in left renal vein stenosis demonstrated via CT

Energy Technology Data Exchange (ETDEWEB)

Lien, H.H.; Lund, G.; Talle, K.

1983-02-01

Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development.

Collateral veins in left renal vein stenosis demonstrated via CT

International Nuclear Information System (INIS)

Lien, H.H.; Lund, G.; Talle, K.

1983-01-01

Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development. (orig.)

High Strain Rate and Shock-Induced Deformation in Metals

Science.gov (United States)

Ravelo, Ramon

2012-02-01

Large-scale non-equilibrium molecular Dynamics (MD) simulations are now commonly used to study material deformation at high strain rates (10^9-10^12 s-1). They can provide detailed information-- such as defect morphology, dislocation densities, and temperature and stress profiles, unavailable or hard to measure experimentally. Computational studies of shock-induced plasticity and melting in fcc and bcc single, mono-crystal metals, exhibit generic characteristics: high elastic limits, large directional anisotropies in the yield stress and pre-melting much below the equilibrium melt temperature for shock wave propagation along specific crystallographic directions. These generic features in the response of single crystals subjected to high strain rates of deformation can be explained from the changes in the energy landscape of the uniaxially compressed crystal lattice. For time scales relevant to dynamic shock loading, the directional-dependence of the yield strength in single crystals is shown to be due to the onset of instabilities in elastic-wave propagation velocities. The elastic-plastic transition threshold can accurately be predicted by a wave-propagation stability analysis. These strain-induced instabilities create incipient defect structures, which can be quite different from the ones, which characterize the long-time, asymptotic state of the compressed solid. With increase compression and strain rate, plastic deformation via extended defects gives way to amorphization associated with the loss in shear rigidity along specific deformation paths. The hot amorphous or (super-cooled liquid) metal re-crystallizes at rates, which depend on the temperature difference between the amorphous solid and the equilibrium melt line. This plastic-amorphous transition threshold can be computed from shear-waves stability analyses. Examples from selected fcc and bcc metals will be presented employing semi-empirical potentials of the embedded atom method (EAM) type as well as

Evolution of supercritical fluid in deeply subducted continental crust: a case study of composite granite-quartz veins in the Sulu belt, China

Science.gov (United States)

Wang, S.; Wang, L.; Brown, M.

2016-12-01

Although fluid plays a key role in element transport and rock strength during subduction to and exhumation from ultrahigh pressure (UHP) metamorphic conditions, the source of supercritical fluid at P above the second critical endpoints (SCE) and the subsequent evolution are not well constrained. To provide insight into the evolution of supercritical fluid in continental subduction zones, we undertook an integrated study of composite granite-quartz veins in retrogressed and migmatitic UHP eclogite at General's Hill, N of Qingdao, in the central Sulu belt. The composite veins are irregularly distributed in the eclogite, which occurs as blocks within gneiss. The granite component is enriched in large ion lithophile elements and light rare earth elements but depleted in high field strength elements and heavy rare earth elements, indicating crystallization from a melt phase of crustal origin. Additionally, the granite contains high modal phengite (22-30 vol%) and clinozoisite/epidote (3-10 vol%), implying precipitation from a H2O-rich silicate melt. By contrast, the quartz component is dominated by SiO2 (99.10 wt%), and contains low total rare earth elements (ΣREE = 0.46 ppm), indicating precipitation from an aqueous fluid. The crystallization age of the composite veins is 221 ± 2 Ma, which is younger than the UHP metamorphism in the Sulu belt at ca 230 Ma, consistent with formation during exhumation. Initial 176Hf/177Hf ratios and δ18O values of metamorphic zircons from the composite veins, and Sr-Nd isotope compositions of the granites all lie between values for eclogite and gneiss, indicating a mixed source. Accordingly, we propose that a supercritical fluid generated from the gneiss and the included blocks of eclogite at P-T conditions above the SCE for both compositions became trapped in the eclogite during exhumation. At P below the SCE for the hydrous granite system, the mixed supercritical fluid separated into immiscible aqueous melt and aqueous fluid and

Focus on Varicose Veins

Science.gov (United States)

... because the valves of the veins no longer work. Under the pressure of gravity these veins can continue to expand and, in ... and to determine whether the vein valves are work- ing properly or have ... painless. How are varicose veins treated? Varicose veins are always ...

Apollo 17 'melt sheet': chemistry, age and Rb/Sr systematics

Energy Technology Data Exchange (ETDEWEB)

Winzer, S R [Martin Marietta Labs., Baltimore, Md. (USA); Nava, D F; Schuhmann, S; Philpotts, J A [National Aeronautics and Space Administration, Greenbelt, Md. (USA). Goddard Space Flight Center; Schuhmann, P J; Lum, R K.L.; Lindstrom, M M; Lindstrom, D J [Maryland Univ., College Park (USA)

1977-01-01

Major, minor and trace element compositions, age data and Rb/Sr systematics of Apollo 17 boulders have been compiled, and additional analyses performed on a norite breccia clast (77215) included in the Apollo 17, Station 7 boulder. The Apollo 17 boulders are found to be identical or nearly so in major, minor and trace element composition, suggesting that they all originated as an impact melt analogous to melt sheets found in larger terrestrial craters. The matrix dates (/sup 40/Ar//sup 39/Ar) and Rb/Sr systematics available suggest that this impact melt formed by a single impact about 4 b.y. ago. This impact excavated, shocked, brecciated and melted norites, norite cumulates and possibly anorthositic gabbros and dunites about 4.4 b.y. old. The impact was likely a major one, possibly the Serenitatis basin-forming event.

Thermal shock testing of TiC-coated molybdenum with pulsed hydrogen beams

International Nuclear Information System (INIS)

Nakamura, Kazuyuki

1985-07-01

Thermal shock testing of molybdenum samples, on which TiC is coated by TP-CVD and CVD methods, has been made by using a pulsed hydrogen beam. The power density applied was 2 kw/cm 2 . The test results showed that TiC coatings did not exfoliate until the melting of the substrate and showed good adhesion under the thermal shock condition. (author)

Molecular dynamics simulations of ejecta production from sinusoidal tin surfaces under supported and unsupported shocks

Directory of Open Access Journals (Sweden)

Bao Wu

2018-04-01

Full Text Available Micro-ejecta, an instability growth process, occurs at metal/vacuum or metal/gas interface when compressed shock wave releases from the free surface that contains surface defects. We present molecular dynamics (MD simulations to investigate the ejecta production from tin surface shocked by supported and unsupported waves with pressures ranging from 8.5 to 60.8 GPa. It is found that the loading waveforms have little effect on spike velocity while remarkably affect the bubble velocity. The bubble velocity of unsupported shock loading remains nonzero constant value at late time as observed in experiments. Besides, the time evolution of ejected mass in the simulations is compared with the recently developed ejecta source model, indicating the suppressed ejection of unmelted or partial melted materials. Moreover, different reference positions are chosen to characterize the amount of ejecta under different loading waveforms. Compared with supported shock case, the ejected mass of unsupported shock case saturates at lower pressure. Through the analysis on unloading path, we find that the temperature of tin sample increases quickly from tensile stress state to zero pressure state, resulting in the melting of bulk tin under decaying shock. Thus, the unsupported wave loading exhibits a lower threshold pressure causing the solid-liquid phase transition on shock release than the supported shock loading.

Spider Vein Removal

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Spider veins: How are they removed? I have spider veins on my legs. What options are available ... M.D. Several options are available to remove spider veins — thin red lines or weblike networks of ...

Partial melting of UHP calc-gneiss from the Dabie Mountains

Science.gov (United States)

Liu, Penglei; Wu, Yao; Liu, Qiang; Zhang, Junfeng; Zhang, Li; Jin, Zhenmin

2014-04-01

Exhumation melting has been proposed for the ultra-high pressure (UHP) metamorphic rocks in the Dabie Mountains based on melting experiments. We document here the first petrological and mineralogical evidence demonstrating that the UHP calc-gneisses from the Ganjialing area in the Dabie Mountains experienced partial melting during early exhumation. The assemblage of garnet, phengite (Si = 3.65 pfu), coesite, rutile and carbonate preserved in the calc-gneisses indicates a peak metamorphic condition of 692-757 °C and 4.0-4.8 GPa. Partial melting is indicated by several lines of evidence: the melting textures of phengite, the feldspar-dominated films, bands, branches, blebs and veins, the euhedral K-feldspars, the intergrowth film of plagioclase and K-feldspar, the plagioclase + biotite intergrowth after garnet and the epidote poikiloblasts. Polyphase inclusions in garnet are characterized with wedge-like offshoots and serrate outlines whereas those in epidote display negative crystal shapes, which can be best interpreted by entrapment of former melts. We propose a wet melting reaction of Phn + Q ± Na-Cpx + H2O = Bt + Pl + Grt + felsic melts, which likely took place at ca.650-800 °C and ca.1.0-2.0 GPa, to interpret the melting event in the calc-gneisses. Chemical exchanges between garnet and melts produced new garnet domains with higher almandine, spessartine, MREE, HREE and Y but lower grossular, pyrope, P, Sc, Ti, V and Zr contents. Zr-in-rutile thermometer reveals a low temperature of 620-643 °C at 5 GPa, indicating a later reset for Zr in rutile. Healed fractures are suggested to be responsible for the formation of some polyphase inclusions in garnet.

What Are Varicose Veins?

Science.gov (United States)

... Leer en español What Is Varicose (VAR-i-kos) veins are swollen, twisted veins that you can ... TA-ze-uhs), spider veins, varicoceles (VAR-i-ko-seals), and other vein problems. Telangiectasias Telangiectasias are ...

Varicose vein - noninvasive treatment

Science.gov (United States)

... spider veins. These are small varicose veins. Salt water (saline) or a chemical solution is injected into the varicose vein. The vein will harden and then disappear. Laser treatment can be used on the surface of the skin. Small bursts ...

Vanadium K Xanes Studies of EET79001 Impact-Melt Glasses Revisited

Science.gov (United States)

Sutton, S. R.; Rao, M. N.; Nyquist, L. E.; Ross, D. K.

2016-01-01

Some impact-melt glasses in shergottites are rich in Martian atmospheric noble gases and sulfur suggesting a possible association with regolith-derived secondary mineral assemblages in the shocked samples. Previously, we studied two glasses, # 506 (Lith C in Lith A) and # 507 (Lith C in Lith B) from EET79001 [1,2] and suggested that sulfur initially existed as sulfate in the glass precursor materials and, on shock-melting of the precursors, the sulfate was reduced to sulfides in the shock glasses. To examine the validity of this hypothesis, we used V K microXANES techniques to measure the valence states of vanadium in the Lith C glasses from Lith A and Lith B in EET79001 [3] to complement and com-pare with previous analogous measurements on,78 glass (Lith C in Lith A) [4,5]. We reported the preliminary results in [3]. Vanadium is ideal for addressing the redox issue because it has multiple valence states and is a well-studied element. Vanadium in basalts exists mostly as V(sup 3+), V(sup 4+) and V(sup 5+) in terrestrial samples, mainly as V(sup 3+) with minor V(sup 2+) and minor V(sup 4+) in lunar samples and as roughly equal mixtures of V(sup 3+) and V(sup 4+) in Martian meteorites. In this report, we discuss the application of the V K XANES results to decipher the nature of shock reduction occurring in the silicate glasses during the impact process.

The Apollo 17 'melt sheet': chemistry, age and Rb/Sr systematics

International Nuclear Information System (INIS)

Winzer, S.R.; Nava, D.F.; Schuhmann, S.; Philpotts, J.A.

1977-01-01

Major, minor and trace element compositions, age data and Rb/Sr systematics of Apollo 17 boulders have been compiled, and additional analyses performed on a norite breccia clast (77215) included in the Apollo 17, Station 7 boulder. The Apollo 17 boulders are found to be identical or nearly so in major, minor and trace element composition, suggesting that they all originated as an impact melt analogous to melt sheets found in larger terrestrial craters. The matrix dates ( 40 Ar/ 39 Ar) and Rb/Sr systematics available suggest that this impact melt formed by a single impact about 4 b.y. ago. This impact excavated, shocked, brecciated and melted norites, norite cumulates and possibly anorthositic gabbros and dunites about 4.4 b.y. old. The impact was likely a major one, possibly the Serenitatis basin-forming event. (Auth.)

Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy - Case report.

Science.gov (United States)

Tang, Jianlin; Abbas, Jihad; Hoetzl, Katherine; Allison, David; Osman, Mahamed; Williams, Mallory; Zelenock, Gerald B

2014-12-01

62 year old Caucasian female with pancreatic head mass abutting the superior mesenteric vein (SMV) presented with fine needle aspiration biopsy confirmed diagnosis of ductal adenocarcinoma. CT scan showed near complete obstruction of portal vein and large SMV collateral development. After 3 months of neoadjuvant therapy, her portal vein flow improved significantly, SMV collateral circulation was diminished. Pancreaticoduodenectomy (PD) and superior mesenteric portal vein (SMPV) confluence resection were performed; A saphenous vein interposition graft thrombosed immediately. The splenic vein remnant was distended and adjacent to the stump of the portal vein. Harvesting an internal jugular vein graft required extra time and using a synthetic graft posed a risk of graft thrombosis or infection. As a result, we chose to perform a direct anastomosis of the portal and splenic vein in a desperate situation. The anastomosis decompressed the mesenteric venous system, so we then ligated the SMV. The patient had an uneventful postoperative course, except transient ascites. She redeveloped ascites more than one year later. At that time a PET scan showed bilateral lung and right femur metastatic disease. She expired 15 months after PD. The lessons we learned are (1) Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2) Synthetic graft is an alternative for internal jugular vein graft. (3) Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4) It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival.

A critical analysis of shock models for chondrule formation

Science.gov (United States)

Stammler, Sebastian M.; Dullemond, Cornelis P.

2014-11-01

In recent years many models of chondrule formation have been proposed. One of those models is the processing of dust in shock waves in protoplanetary disks. In this model, the dust and the chondrule precursors are overrun by shock waves, which heat them up by frictional heating and thermal exchange with the gas. In this paper we reanalyze the nebular shock model of chondrule formation and focus on the downstream boundary condition. We show that for large-scale plane-parallel chondrule-melting shocks the postshock equilibrium temperature is too high to avoid volatile loss. Even if we include radiative cooling in lateral directions out of the disk plane into our model (thereby breaking strict plane-parallel geometry) we find that for a realistic vertical extent of the solar nebula disk the temperature decline is not fast enough. On the other hand, if we assume that the shock is entirely optically thin so that particles can radiate freely, the cooling rates are too high to produce the observed chondrules textures. Global nebular shocks are therefore problematic as the primary sources of chondrules.

Noninvasive optoacoustic system for rapid diagnostics and management of circulatory shock

Science.gov (United States)

Esenaliev, Rinat O.; Petrov, Irene Y.; Petrov, Yuriy; Kinsky, Michael; Prough, Donald S.

2012-02-01

Circulatory shock is lethal, if not promptly diagnosed and effectively treated. Typically, circulatory shock resuscitation is guided by blood pressure, heart rate, and mental status, which have poor predictive value. In patients, in whom early goaldirected therapy was applied using central venous oxygenation measurement, a substantial reduction of mortality was reported (from 46.5% to 30%). However, central venous catheterization is invasive, time-consuming and often results in complications. We proposed to use the optoacoustic technique for noninvasive, rapid assessment of central venous oxygenation. In our previous works we demonstrated that the optoacoustic technique can provide measurement of blood oxygenation in veins and arteries due to high contrast and high resolution. In this work we developed a novel optoacoustic system for noninvasive, automatic, real-time, and continuous measurement of central venous oxygenation. We performed pilot clinical tests of the system in human subjects with different oxygenation in the internal jugular vein and subclavian vein. A novel optoacoustic interface incorporating highly-sensitive optoacoustic probes and standard ultrasound imaging probes were developed and built for the study. Ultrasound imaging systems Vivid i and hand-held Vscan (GE Healthcare) as well as Site-Rite 5 (C.R. Bard) were used in the study. We developed a special algorithm for oxygenation monitoring with minimal influence of overlying tissue. The data demonstrate that the system provides precise measurement of venous oxygenation continuously and in real time. Both current value of the venous oxygenation and trend (in absolute values and for specified time intervals) are displayed in the system. The data indicate that: 1) the optoacoustic system developed by our group is capable of noninvasive measurement of blood oxygenation in specific veins; 2) clinical ultrasound imaging systems can facilitate optoacoustic probing of specific blood vessels; 3) the

Improving the understanding of the melting behaviour of Mo, Ta, and W at extreme pressures

International Nuclear Information System (INIS)

Errandonea, Daniel

2005-01-01

We discuss the existing conflicts between experimentally measured and theoretically calculated melting curves of Mo, Ta, and W. By assuming that vacancy formation plays a fundamental role in the melting process, an explanation for the measured melting curves is provided. Furthermore, we show that the Lindemann law fits well all the measured melting curves of BCC transition metals if the Grueneisen parameter is written as a power series of the interatomic distance. For completeness, we examine possible reasons for current disagreements between shock-wave and DAC experiments. To solve them, we propose the existence of an extra high P-T phase for Mo, Ta, and W

Improving the Outcome of Vein Grafts: Should Vascular Surgeons Turn Veins into Arteries?

OpenAIRE

Isaji, Toshihiko; Hashimoto, Takuya; Yamamoto, Kota; Santana, Jeans M.; Yatsula, Bogdan; Hu, Haidi; Bai, Hualong; Jianming, Guo; Kudze, Tambudzai; Nishibe, Toshiya; Dardik, Alan

2017-01-01

Autogenous vein grafts remain the gold standard conduit for arterial bypass, particularly for the treatment of critical limb ischemia. Vein graft adaptation to the arterial environment, i.e., adequate dilation and wall thickening, contributes to the superior performance of vein grafts. However, abnormal venous wall remodeling with excessive neointimal hyperplasia commonly causes vein graft failure. Since the PREVENT trials failed to improve vein graft outcomes, new strategies focus on the ada...

Right Site, Wrong Route - Cannulating the Left Internal Jugular Vein.

Science.gov (United States)

Paik, Peter; Arukala, Sanjay K; Sule, Anupam A

2018-01-09

Central venous catheters are placed in approximately five million patients annually in the US. The preferred site of insertion is one with fewer risks and easier access. Although the right internal jugular vein is preferred, on occasion, the left internal jugular may have to be accessed. A patient was admitted for septic shock, cerebrovascular accident, and non-ST-segment elevation myocardial infarction. A central venous line was needed for antibiotic and vasopressor administration. Due to trauma from a fall to the right side and previously failed catheterization attempts at the left subclavian and femoral veins, the left internal jugular vein was accessed. On chest radiography for confirmation, the left internal jugular central venous catheter was seen projecting down the left paraspinal region. It did not take the expected course across the midline toward the right and into the superior vena cava (SVC). A review of a computed tomography (CT) scan of the chest with contrast done on a prior admission revealed a duplicated SVC on the left side that had not been reported in the original CT scan interpretation. A left-sided SVC is present in approximately 0.3% to 0.5% of the population, with 90% of these draining into the coronary sinus. During placements of central venous lines and pacemakers, irritation of the coronary sinus may result in hypotension, arrhythmia, myocardial ischemia, or cardiac arrest. A widened mediastinum can be an indication of a duplicated SVC. When attempting a left internal jugular vein central venous catheter placement, it is important to be aware of venous anomalies in order to prevent complications.

Thermal shock test of TiC and graphite

International Nuclear Information System (INIS)

Shirakawa, H.; Okamura, J.; Son, P.; Miyake, M.

1989-01-01

Thermal shock tests were performed by pulse electron beam heating on chemically vapor deposited coatings of TiC on Poco graphite, bulk TiC, and several kinds of isotropic graphite. The specimens were heated at various power densities (10-45 MW/m 2 ) for various pulse durations (1-2 s) to examine the dependence of thermal failures on heating conditions. The TiC coating on graphite suffered cracking, surface melting and evaporation by the thermal pulse. The surface melting limit, defined as F τ 1/2 , where F is the minimum power density that causes surface melting for a specified pulse duration τ, was approximately 48 MWs 1/2 /m 2 for the TiC coating. The combined-Carbon/Titanium ratio of the coating after electron beam heating decreased with increasing power density and pulse duration. The bulk TiC specimens were so brittle that they fractured at heat load conditions where the coating showed no damage. The graphite specimens showed sublimation as a principal damage mechanism by the thermal pulse, and the sublimation weight loss decreased with increasing the thermal conductivity of the specimen. It was confirmed that the TiC coating on graphite had favorable resistance to thermal shock as compared to the bulk TiC and that graphite with high thermal conductivity is promising material as a high heat flux component. (orig.)

Accessory hepatic vein: MR imaging

International Nuclear Information System (INIS)

Lee, Chang Hee; Rho, Tack Soo; Cha, Sang Hoon; Park, Cheol Min; Cha, In Ho

1995-01-01

To evaluate the MR appearance of the accessory hepatic veins. The study included 87 consecutive patients for whom abdominal MR images were obtained. The subjects who had liver lesion or hepatic vascular abnormalities were excluded. Couinaud classified accessory hepatic veins into inferior and middle right hepatic veins. Our major interests were evaluation of the incidence, morphology, and location of the accessory hepatic vein. Inferior right hepatic vein was demonstrated in 43 out of 87 patients (49%). The morphology was linear in 35 patients (80.5%), and V-shaped in 8 patients (19.5%). In 40 patients (93%), the inferior right hepatic vein was located in the posteroinferior aspect of the right lobe. Middle right hepatic vein was demonstrated in 7 out of 87 patients (8%). All were single linear in morphology, combined with the inferior right hepatic vein, and located between the right hepatic vein and inferior right hepatic vein. The accessory hepatic vein was demonstrated in 49% among the Korean adult population, and was located in posteroinferior portion of the liver, in 93%

Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy – Case report

Science.gov (United States)

Tang, Jianlin; Abbas, Jihad; Hoetzl, Katherine; Allison, David; Osman, Mahamed; Williams, Mallory; Zelenock, Gerald B.

2014-01-01

62 year old Caucasian female with pancreatic head mass abutting the superior mesenteric vein (SMV) presented with fine needle aspiration biopsy confirmed diagnosis of ductal adenocarcinoma. CT scan showed near complete obstruction of portal vein and large SMV collateral development. After 3 months of neoadjuvant therapy, her portal vein flow improved significantly, SMV collateral circulation was diminished. Pancreaticoduodenectomy (PD) and superior mesenteric portal vein (SMPV) confluence resection were performed; A saphenous vein interposition graft thrombosed immediately. The splenic vein remnant was distended and adjacent to the stump of the portal vein. Harvesting an internal jugular vein graft required extra time and using a synthetic graft posed a risk of graft thrombosis or infection. As a result, we chose to perform a direct anastomosis of the portal and splenic vein in a desperate situation. The anastomosis decompressed the mesenteric venous system, so we then ligated the SMV. The patient had an uneventful postoperative course, except transient ascites. She redeveloped ascites more than one year later. At that time a PET scan showed bilateral lung and right femur metastatic disease. She expired 15 months after PD. Conclusion The lessons we learned are (1) Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2) Synthetic graft is an alternative for internal jugular vein graft. (3) Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4) It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival. PMID:25568802

Shock Compression and Melting of an Fe-Ni-Si Alloy: Implications for the Temperature Profile of the Earth's Core and the Heat Flux Across the Core-Mantle Boundary

Science.gov (United States)

Zhang, Youjun; Sekine, Toshimori; Lin, Jung-Fu; He, Hongliang; Liu, Fusheng; Zhang, Mingjian; Sato, Tomoko; Zhu, Wenjun; Yu, Yin

2018-02-01

Understanding the melting behavior and the thermal equation of state of Fe-Ni alloyed with candidate light elements at conditions of the Earth's core is critical for our knowledge of the region's thermal structure and chemical composition and the heat flow across the liquid outer core into the lowermost mantle. Here we studied the shock equation of state and melting curve of an Fe-8 wt% Ni-10 wt% Si alloy up to 250 GPa by hypervelocity impacts with direct velocity and reliable temperature measurements. Our results show that the addition of 10 wt% Si to Fe-8 wt% Ni alloy slightly depresses the melting temperature of iron by 200-300 (±200) K at the core-mantle boundary ( 136 GPa) and by 600-800 (±500) K at the inner core-outer core boundary ( 330 GPa), respectively. Our results indicate that Si has a relatively mild effect on the melting temperature of iron compared with S and O. Our thermodynamic modeling shows that Fe-5 wt% Ni alloyed with 6 wt% Si and 2 wt% S (which has a density-velocity profile that matches the outer core's seismic profile well) exhibits an adiabatic profile with temperatures of 3900 K and 5300 K at the top and bottom of the outer core, respectively. If Si is a major light element in the core, a geotherm modeled for the outer core indicates a thermal gradient of 5.8-6.8 (±1.6) K/km in the D″ region and a high heat flow of 13-19 TW across the core-mantle boundary.

Influence of recrystallization on thermal shock resistance of various tungsten grades

International Nuclear Information System (INIS)

Uytdenhouwen, I.; Decreton, M.; Hirai, T.; Linke, J.; Pintsuk, G.; Oost, G. van

2007-01-01

Thermal shock resistance of various tungsten grades (different manufacturing technologies and heat treatments) was examined under plasma disruption conditions, especially in the cracking regime, i.e. below the melting threshold. The tests have been simulated with the electron beam test facility JUDITH. The comparison of the thermal shock resistance showed that sintered tungsten appeared to be better than the deformed tungsten material and clear degradation after recrystallization was found. Damage processes linked to the mechanical properties of W are discussed

Micro-X-ray diffraction assessment of shock stage in enstatite chondrites

Science.gov (United States)

Izawa, Matthew R. M.; Flemming, Roberta L.; Banerjee, Neil R.; McCausland, Philip J. A.

2011-05-01

A new method for assessing the shock stage of enstatite chondrites has been developed, using in situ micro-X-ray diffraction (μXRD) to measure the full width at half maximum (FWHMχ) of peak intensity distributed along the direction of the Debye rings, or chi angle (χ), corresponding to individual lattice reflections in two-dimensional XRD patterns. This μXRD technique differs from previous XRD shock characterization methods: it does not require single crystals or powders. In situ μXRD has been applied to polished thin sections and whole-rock meteorite samples. Three frequently observed orthoenstatite reflections were measured: (020), (610), and (131); these were selected as they did not overlap with diffraction lines from other phases. Enstatite chondrites are commonly fine grained, stained or darkened by weathering, shock-induced oxidation, and metal/sulfide inclusions; furthermore, most E chondrites have little olivine or plagioclase. These characteristics inhibit transmitted-light petrography, nevertheless, shock stages have been assigned MacAlpine Hills (MAC) 02837 (EL3) S3, Pecora Escarpment (PCA) 91020 (EL3) S5, MAC 02747 (EL4) S4, Thiel Mountains (TIL) 91714 (EL5) S2, Allan Hills (ALHA) 81021 (EL6) S2, Elephant Moraine (EET) 87746 (EH3) S3, Meteorite Hills (MET) 00783 (EH4) S4, EET 96135 (EH4-5) S2, Lewis Cliff (LEW) 88180 (EH5) S2, Queen Alexandra Range (QUE) 94204 (EH7) S2, LaPaz Icefield (LAP) 02225 (EH impact melt) S1; for the six with published shock stages, there is agreement with the published classification. FWHMχ plotted against petrographic shock stage demonstrates positive linear correlation. FWHMχ ranges corresponding to shock stages were assigned as follows: S1 3.5°, S6—not measured. Slabs of Abee (EH impact-melt breccia), and Northwest Africa (NWA) 2212 (EL6) were examined using μXRD alone; FWHMχ values place both in the S2 range, consistent with literature values. Micro-XRD analysis may be applicable to other shocked orthopyroxene

Shock wave overtake measurements on cesium iodide

International Nuclear Information System (INIS)

Swenson, C.A.

1986-01-01

The luminosity of the shock front for CsI makes it an ideal material for which to measure directly sound velocities along the Hugoniot using shock wave overtake methods. In these measurements, the occurrence of melting along the Hugoniot is marked by a discontinuous decrease in the measured sound velocity. In addition, CsI is isoelectronic with xenon and is expected to begin to show metallic behavior along the Hugoniot near 0.9 Mbar. The directly-determined sound velocities and corresponding elastic moduli would be expected to be more sensitive to this transition than either Hugoniot equations of state or optical pyrometry experiments. This paper presents a brief description of the present experiments and results

Varicose Veins - Multiple Languages

Science.gov (United States)

... Concerns and Discomforts of Pregnancy: Varicose Veins - English MP3 Concerns and Discomforts of Pregnancy: Varicose Veins - 简体中文 (Chinese, Simplified (Mandarin dialect)) MP3 Concerns and Discomforts of Pregnancy: Varicose Veins - English ...

Valsalva and gravitational variability of the internal jugular vein and common femoral vein: Ultrasound assessment

Energy Technology Data Exchange (ETDEWEB)

Beddy, P. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland)]. E-mail: pbeddy@eircom.net; Geoghegan, T. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Ramesh, N. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Buckley, O. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); O' Brien, J. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Colville, J. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland); Torreggiani, W.C. [Department of Radiology, The Adelaide and Meath Hospital, Tallaght, Dublin 24 (Ireland)

2006-05-15

Purpose: Central venous cannulation via the common femoral vein is an important starting point for many interventions. The purpose of this study was to determine the optimum conditions for cannulation of the femoral vein and to compare these with the relative changes in the internal jugular vein. Methods: High-resolution 2D ultrasound was utilised to determine variability of the calibre of the femoral and internal jugular veins in 10 healthy subjects. Venous diameter was assessed during the Valsalva manoeuvre and in different degrees of the Trendelenburg position. Results: The Valsalva manoeuvre significantly increased the size of the femoral and internal jugular veins. There was a relatively greater increase in femoral vein diameter when compared with the internal jugular vein of 40 and 29%, respectively. Changes in body inclination (Trendelenburg position) did not significantly alter the luminal diameter of the femoral vein. However, it significantly increased internal jugular vein diameter. Conclusions: Femoral vein cannulation is augmented by the Valsalva manoeuvre but not significantly altered by the gravitational position of the subject.

Experimental Shock Transformation of Gypsum to Anhydrite: A New Low Pressure Regime Shock Indicator

Science.gov (United States)

Bell, Mary S.; Zolensky, Michael E.

2011-01-01

The shock behavior of gypsum is important in understanding the Cretaceous/Paleogene event and other terrestrial impacts that contain evaporite sediments in their targets (e.g., Mars Exploration Rover Spirit detected sulfate at Gusev crater, [1]). Most interest focuses on issues of devolatilization to quantify the production of SO2 to better understand its role in generating a temporary atmosphere and its effects on climate and biota [2,3]. Kondo and Ahrens [4] measured induced radiation emitted from single crystal gypsum shocked to 30 and 40 GPa. They observed greybody emission spectra corresponding to temperatures in the range of 3,000 to 4,000 K that are a factor of 2 to 10 times greater than calculated pressure-density energy equation of state temperatures (Hugoniot) and are high enough to melt gypsum. Chen et al. [5] reported results of shock experiments on anhydrite, gypsum, and mixtures of these phases with silica. Their observations indicated little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another report of shock experiments on calcite, anhydrite, and gypsum, Badjukov et al. [6] observed only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa but have not experimentally shocked gypsum in a step-wise manner to constrain possible incipient transformation effects. Schmitt and Hornemann [7] shock loaded anhydrite and quartz to a peak pressure of 60 GPa and report the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggested that recrystallization of anhydrite grains is the result of a solid-state transformation. They concluded that significant decomposition of anhydrite requires shock pressures higher than 60 GPa. Gupta et al. [8

CT findings of portal vein aneurysm

International Nuclear Information System (INIS)

Yang, Dal Mo; Chang, Mi Son; Yoon, Myung Hwan; Kim, Hak Soo; Kim, Hyung Sik; Chung, Hyo Sun; Chung, Jin Woo

1999-01-01

To describe the CT findings of portal vein aneurysm in eight patients. All patients included in this study (two men and six women) underwent CT examinations between October 1996 and June1998. Of these eight, three were suffering from hepatic disease and portal hypertension. We determined the location, shape, size, and characteristics of the lesions, and the presence or absence of portal vein anomaly. Seven patients had intrahepatic portal vein aneurysm (at the umbilical portion of the left portal vein in five patients, between the transverse and umbilical portion of the left portal vein in one, and at the bifurcation of the anterior and posterior branch of the right portal vein in one), while extrahepatic portal vein aneurysm, at the confluence of the superior mesenteric and splenic vein was found in only one. Lesions were cyst-shaped in seven cases and saccular in one, and showed well-circumscribed, markedly enhanced mass, which communicated with the portal vein and/or gives off major branches. Portal vein anomaly, in which the right anterior segmental portal vein originated from the umbilical portion of the left portal vein, was seen in three patients. In all three, intrahepatic portal vein aneurysm was present at the umbilical portion of the left portal vein, and in one, the umbilical protion of the left portal vein was located to the right of the Cantlic line. CT examination can help reveal portal vein aneurysm by detecting a well-circumscribed, markedly enhanced mass which communicates with the portal vein and/or gives off major branches

Alloy synthesis using the mach stem region in an axial symmetric implosive shock: Understanding the pressure strain-temperature contributions

Energy Technology Data Exchange (ETDEWEB)

Staudhammer, Karl P.

2004-01-01

The Mach stem region in an axial symmetric shock implosion has generally been avoided in the dynamic consolidation of powders for a number of reasons. The prime reason being that the convergence of the shock waves in the cylindrical axis produce enormous pressures and concomitant temperatures that have melted tungsten. This shock wave convergence consequently results in a discontinuity in the hydro-code calculations. Dynamic deformation experiments on gold plated 304L stainless steel powders were undertaken. These experiments utilized pressures of 0.08 to 1.0 Mbar and contained a symmetric radial melt region along the central axis of the sample holder. To understand the role of deformation in a porous material, the pressure, and temperature as well as the deformation heat and associated defects must be accounted for. When the added heat of consolidation deformation exceeds the melt temperature of the 304 powders, a melt zone results that can consume large regions of the compact while still under the high-pressure pulse. As the shock wave traverses the sample and is removed in a momentum trap, its pressure/temperature are quenched. It is within this region that very high diffusion/alloying occurs and has been observed in the gold plated powders. Anomalous increases of gold diffusion into 304 stainless steel have been observed via optical microscopy, scanning electron microscopy and EDAX measurements. Values exceeding 1200 m/sec have been measured and correlated to the powder sizes, size distribution and packing density, concomitant with sample container strains ranging from 2.0% to 26%.

Comparison between mechanical properties of human saphenous vein and umbilical vein

Directory of Open Access Journals (Sweden)

Hamedani Borhan

2012-08-01

Full Text Available Abstract Background As a main cause of mortality in developed countries, Coronary Artery Disease (CAD is known as silent killer with a considerable cost to be dedicated for its treatment. Coronary Artery Bypass Graft (CABG is a common remedy for CAD for which different blood vessels are used as a detour. There is a lack of knowledge about mechanical properties of human blood vessels used for CABG, and while these properties have a great impact on long-term patency of a CABG. Thus, studying these properties, especially those of human umbilical veins which have not been considered yet, looks utterly necessary. Methods Umbilical vein, as well as human Saphenous vein, are respectively obtained after cesarean and CABG. First, histological tests were performed to investigate different fiber contents of the samples. Having prepared samples carefully, force-displacement results of samples were rendered to real stress–strain measurements and then a fourth-order polynomial was used to prove the non-linear behavior of these two vessels. Results Results were analyzed in two directions, i.e. circumferentially and longitudinally, which then were compared with each other. The comparison between stiffness and elasticity of these veins showed that Saphenous vein’s stiffness is much higher than that of umbilical vein and also, it is less stretchable. Furthermore, for both vessels, longitudinal stiffness was higher than that of circumferential and in stark contrast, stretch ratio in circumferential direction came much higher than longitudinal orientation. Conclusion Blood pressure is very high in the region of aorta, so there should be a stiff blood vessel in this area and previous investigations showed that stiffer vessels would have a better influence on the flow of bypass. To this end, the current study has made an attempt to compare these two blood vessels’ stiffness, finding that Saphenous vein is stiffer than umbilical vein which is somehow as stiff as

Vein grafting in fingertip replantations.

Science.gov (United States)

Yan, Hede; Jackson, William D; Songcharoen, Somjade; Akdemir, Ovunc; Li, Zhijie; Chen, Xinglong; Jiang, Liangfu; Gao, Weiyang

2009-01-01

In this retrospective study, the survival rates of fingertip replantation with and without vein grafting were evaluated along with their postoperative functional and cosmetic results. One hundred twenty-one-fingertip amputations were performed in 103 patients between September 2002 and July 2007. Thirty-four amputated fingertips were replanted without vein grafting, while 87 amputated fingertips were replanted with vein grafting for arterial and/or venous repairs. The overall survival rates of the replantations with and without vein grafting were 90% (78/87) and 85% (29/34), respectively. The survival rates were 88% (36/41) with venous repair, 93% (25/27) with arterial repair, and 89% (17/19) with both. Nineteen patients without vein grafting and 48 patients with vein grafting had a follow-up period of more than one year. Good cosmetic and functional outcomes were observed in both groups of patients. The results show that vein grafting is a reliable technique in fingertip replantations, showing no significant difference (P > 0.05) in survival between those with and without vein grafting. Furthermore, no significant difference (P > 0.05) in survival was found between cases with vein grafts for arterial and/or venous repairs. In fingertip replantations with vein grafting, favorable functional and esthetic results can be achieved without sacrificing replantation survival. (c) 2009 Wiley-Liss, Inc.

About the Shape of the Melting Line as a Possible Precursor of a Liquid-Liquid Phase Transition

Science.gov (United States)

Imre, Attila R.; Rzoska, Sylwester J.

Several simple, non-mesogenic liquids can exists in two or more different liquid forms. When the liquid-liquid line, separating two liquid forms, meets the melting line, one can expect some kind of break on the melting line, caused by the different freezing/melting behaviour of the two liquid forms. Unfortunately recently several researchers are using this vein of thinking in reverse; seeing some irregularity on the melting line, they will expect a break and the appearance of a liquid-liquid line. In this short paper, we are going to show, that in the case of the high-pressure nitrogen studied recently by Mukherjee and Boehler, the high-pressure data can be easily described by a smooth, break-free function, the modified Simon-Glatzel equation. In this way, the break, suggested by them and consequently the suggested appearance of a new liquid phase of the nitrogen might be artefacts.

Vein matching using artificial neural network in vein authentication systems

Science.gov (United States)

Noori Hoshyar, Azadeh; Sulaiman, Riza

2011-10-01

Personal identification technology as security systems is developing rapidly. Traditional authentication modes like key; password; card are not safe enough because they could be stolen or easily forgotten. Biometric as developed technology has been applied to a wide range of systems. According to different researchers, vein biometric is a good candidate among other biometric traits such as fingerprint, hand geometry, voice, DNA and etc for authentication systems. Vein authentication systems can be designed by different methodologies. All the methodologies consist of matching stage which is too important for final verification of the system. Neural Network is an effective methodology for matching and recognizing individuals in authentication systems. Therefore, this paper explains and implements the Neural Network methodology for finger vein authentication system. Neural Network is trained in Matlab to match the vein features of authentication system. The Network simulation shows the quality of matching as 95% which is a good performance for authentication system matching.

Absence of Middle Hepatic Vein Combined with Retro-Aortic Left Renal Vein: a Very Rare Case Report

Directory of Open Access Journals (Sweden)

Sezer Akçer

2012-06-01

Full Text Available The hepatic and renal veins drain into the inferior vena cava. The upper group of hepatic veins consists of three veins which extend to the posterior face of the liver to join the inferior cava. The left renal vein passes anterior to the aorta just below the origin of the superior mesenteric artery. We detected a variation in the hepatic and renal veins in a multislice CT angiogram of a nine-year-old male patient in the Radiology Department of Afyon Kocatepe University Medical School. The upper group hepatic veins normally drains into the inferior vena cava as three separate trunks, namely the right, left and middle. In our case, we found that only the right and left hepatic veins existed and the middle hepatic vein was absent. Furthermore, the left renal vein, which normally passes anterior to the abdominal aorta, was retro-aortic. Left renal vein variations are of great importance in planning retroperitoneal surgery and vascular interventions. Knowledge of a patient’s hepatic vein and renovascular anatomy and determining their variations and anomalies are of critical importance to abdominal operations, transplantations and preoperative evaluation of endovascular interventions.

Surgical Access to Jejunal Veins for Local Thrombolysis and Stent Placement in Portal Vein Thrombosis

International Nuclear Information System (INIS)

Schellhammer, Frank; Esch, Jan Schulte am; Hammerschlag, Sascha; Knoefel, Wolfram Trudo; Fuerst, Guenter

2008-01-01

Portal vein thrombosis is an infrequent entity, which may cause high morbidity and mortality. We report a case of portal vein thrombosis due to benign stenosis following partial pancreatoduodenectomy with segmental replacement of the portal vein by a Gore-tex graft. Using a surgical access to jenunal veins, local thrombolysis, mechanical fragmentation of thrombus, and stent placement were successfully performed.

Effects of Friction and Plastic Deformation in Shock-Comminuted Damaged Rocks on Impact Heating

Science.gov (United States)

Kurosawa, Kosuke; Genda, Hidenori

2018-01-01

Hypervelocity impacts cause significant heating of planetary bodies. Such events are recorded by a reset of 40Ar-36Ar ages and/or impact melts. Here we investigate the influence of friction and plastic deformation in shock-generated comminuted rocks on the degree of impact heating using the iSALE shock-physics code. We demonstrate that conversion from kinetic to internal energy in the targets with strength occurs during pressure release, and additional heating becomes significant for low-velocity impacts (projectile mass to temperatures for the onset of Ar loss and melting from 8 and 10 km s-1, respectively, for strengthless rocks to 2 and 6 km s-1 for typical rocks. Our results suggest that the impact conditions required to produce the unique features caused by impact heating span a much wider range than previously thought.

Investigating the response of biotite to impact metamorphism: Examples from the Steen River impact structure, Canada

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Walton, E. L.; Sharp, T. G.; Hu, J.; Tschauner, O.

2018-01-01

Impact metamorphic effects from quartz and feldspar and to a lesser extent olivine and pyroxene have been studied in detail. Comparatively, studies documenting shock effects in other minerals, such as double chain inosilicates, phyllosilicates, carbonates, and sulfates, are lacking. In this study, we investigate impact metamorphism recorded in crystalline basement rocks from the Steen River impact structure (SRIS), a 25 km diameter complex crater in NW Alberta, Canada. An array of advanced analytical techniques was used to characterize the breakdown of biotite in two distinct settings: along the margins of localized regions of shock melting and within granitic target rocks entrained as clasts in a breccia. In response to elevated temperature gradients along shock vein margins, biotite transformed at high pressure to an almandine-Ca/Fe majorite-rich garnet with a density of 4.2 g cm-3. The shock-produced garnets are poikilitic, with oxide and silicate glass inclusions. Areas interstitial to garnets are vesiculated, in support of models for the formation of shock veins via oscillatory slip, with deformation continuing during pressure release. Biotite within granitic clasts entrained within the hot breccia matrix thermally decomposed at ambient pressure to produce a fine-grained mineral assemblage of orthopyroxene + sanidine + titanomagnetite. These minerals are aligned to the (001) cleavage plane of the original crystal. In this and previous work, the transformation of an inosilicate (pargasite) and a phyllosilicate (biotite) to form garnet, an easily identifiable, robust mineral, has been documented. We contend that in deeply eroded astroblemes, high-pressure minerals that form within or in the environs of shock veins may serve as one of the possibly few surviving indicators of impact metamorphism.

The economics of vein disease.

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Sales, Clifford M; Podnos, Joan; Levison, Jonathan

2007-09-01

The management of cosmetic vein problems requires a very different approach than that for the majority of most other vascular disorders that occur in a vascular surgery practice. This article focuses on the business aspects of a cosmetic vein practice, with particular attention to the uniqueness of these issues. Managing patient expectations is critical to the success of a cosmetic vein practice. Maneuvering within the insurance can be difficult and frustrating for both the patient and the practice. Practices should use cost accounting principles to evaluate the success of their vein work. Vein surgery--especially if performed within the office--can undergo an accurate break-even analysis to determine its profitability.

Deep Vein Thrombosis

African Journals Online (AJOL)

OWNER

Deep Vein Thrombosis: Risk Factors and Prevention in Surgical Patients. Deep Vein ... preventable morbidity and mortality in hospitalized surgical patients. ... the elderly.3,4 It is very rare before the age ... depends on the risk level; therefore an .... but also in the post-operative period. ... is continuing uncertainty regarding.

Arabidopsis thaliana Ei-5: Minor Vein Architecture Adjustment Compensates for Low Vein Density in Support of Photosynthesis.

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Stewart, Jared J; Polutchko, Stephanie K; Demmig-Adams, Barbara; Adams, William W

2018-01-01

An Arabidopsis thaliana accession with naturally low vein density, Eifel-5 (Ei-5), was compared to Columbia-0 (Col-0) with respect to rosette growth, foliar vein architecture, photosynthesis, and transpiration. In addition to having to a lower vein density, Ei-5 grew more slowly, with significantly lower rates of rosette expansion, but had similar capacities for photosynthetic oxygen evolution on a leaf area basis compared to Col-0. The individual foliar minor veins were larger in Ei-5, with a greater number of vascular cells per vein, compared to Col-0. This compensation for low vein density resulted in similar values for the product of vein density × phloem cell number per minor vein in Ei-5 and Col-0, which suggests a similar capacity for foliar sugar export to support similar photosynthetic capacities per unit leaf area. In contrast, the product of vein density × xylem cell number per minor vein was significantly greater in Ei-5 compared to Col-0, and was associated not only with a higher ratio of water-transporting tracheary elements versus sugar-transporting sieve elements but also significantly higher foliar transpiration rates per leaf area in Ei-5. In contrast, previous studies in other systems had reported higher ratios of tracheary to sieve elements and higher transpiration rate to be associated with higher - rather than lower - vein densities. The Ei-5 accession thus further underscores the plasticity of the foliar vasculature by illustrating an example where a higher ratio of tracheary to sieve elements is associated with a lower vein density. Establishment of the Ei-5 accession, with a low vein density but an apparent overcapacity for water flux through the foliar xylem network, may have been facilitated by a higher level of precipitation in its habitat of origin compared to that of the Col-0 accession.

Low-pressure differentiation of tholeiitic lavas as recorded in segregation veins from Reykjanes (Iceland), Lanzarote (Canary Islands) and Masaya (Nicaragua)

Science.gov (United States)

Martin, E.; Sigmarsson, O.

2007-11-01

Segregation veins are common in lava sheets and result from internal differentiation during lava emplacement and degassing. They consist of evolved liquid, most likely replaced by gas-filter pressing from a ˜50% crystallised host lava. Pairs of samples, host lavas and associated segregation veins from the Reykjanes Peninsula (Iceland), Lanzarote (Canary Islands) and the Masaya volcano (Nicaragua) show extreme mineralogical and compositional variations (MgO in host lava, segregation veins and interstitial glass ranges from 8-10 wt%, 3-6 wt%, and to less than 0.01 wt%, respectively). These samples allow the assessment of the internal lava flow differentiation mechanism, since both the parental and derived liquid are known in addition to the last magma drops in the form of late interstitial glasses. The mineralogical variation, mass-balance calculated from major- and trace element composition, and transitional metal partition between crystals and melts are all consistent with fractional crystallisation as the dominant differentiation mechanism. The interstitial glasses are highly silicic (SiO2 = 70-80 wt%) and represent a final product of high-degree (75-97%) fractional crystallisation of olivine tholeiite at a pressure close to one atmosphere. The tholeiitic liquid-line-of-decent and the composition of the residual melts are governed by the K2O/Na2O of the initial basaltic magma. The granitic minimum is reached if the initial liquid has a high K2O/Na2O whereas trondhjemitic composition is the final product of magma with low initial K2O/Na2O.

Attenuation of shock waves in copper and stainless steel

International Nuclear Information System (INIS)

Harvey, W.B.

1986-06-01

By using shock pins, data were gathered on the trajectories of shock waves in stainless steel (SS-304L) and oxygen-free-high-conductivity copper (OFHC-Cu). Shock pressures were generated in these materials by impacting the appropriate target with thin (approx.1.5 mm) flying plates. The flying plates in these experiments were accelerated to high velocities (approx.4 km/s) by high explosives. Six experiments were conducted, three using SS-304L as the target material and three experiments using OFHC-Cu as the target material. Peak shock pressures generated in the steel experiments were approximately 109, 130, and 147 GPa and in the copper experiments, the peak shock pressures were approximately 111, 132, and 143 GPa. In each experiment, an attenuation of the shock wave by a following release wave was clearly observed. An extensive effort using two characteristic codes (described in this work) to theoretically calculate the attenuation of the shock waves was made. The efficacy of several different constitutive equations to successfully model the experiments was studied by comparing the calculated shock trajectories to the experimental data. Based on such comparisons, the conclusion can be drawn that OFHC-Cu enters a melt phase at about 130 GPa on the principal Hugoniot. There was no sign of phase changes in the stainless-steel experiments. In order to match the observed attenuation of the shock waves in the SS-304L experiments, it was necessary to include strength effects in the calculations. It was found that the values for the parameters in the strength equations were dependent on the equation of state used in the modeling of the experiments. 66 refs., 194 figs., 77 tabs

Attenuation of shock waves in copper and stainless steel

Energy Technology Data Exchange (ETDEWEB)

Harvey, W.B.

1986-06-01

By using shock pins, data were gathered on the trajectories of shock waves in stainless steel (SS-304L) and oxygen-free-high-conductivity copper (OFHC-Cu). Shock pressures were generated in these materials by impacting the appropriate target with thin (approx.1.5 mm) flying plates. The flying plates in these experiments were accelerated to high velocities (approx.4 km/s) by high explosives. Six experiments were conducted, three using SS-304L as the target material and three experiments using OFHC-Cu as the target material. Peak shock pressures generated in the steel experiments were approximately 109, 130, and 147 GPa and in the copper experiments, the peak shock pressures were approximately 111, 132, and 143 GPa. In each experiment, an attenuation of the shock wave by a following release wave was clearly observed. An extensive effort using two characteristic codes (described in this work) to theoretically calculate the attenuation of the shock waves was made. The efficacy of several different constitutive equations to successfully model the experiments was studied by comparing the calculated shock trajectories to the experimental data. Based on such comparisons, the conclusion can be drawn that OFHC-Cu enters a melt phase at about 130 GPa on the principal Hugoniot. There was no sign of phase changes in the stainless-steel experiments. In order to match the observed attenuation of the shock waves in the SS-304L experiments, it was necessary to include strength effects in the calculations. It was found that the values for the parameters in the strength equations were dependent on the equation of state used in the modeling of the experiments. 66 refs., 194 figs., 77 tabs.

Investigation of Surface Phenomena in Shocked Tin in Converging Geometry

Energy Technology Data Exchange (ETDEWEB)

Rousculp, Christopher L. [Los Alamos National Laboratory; Oro, David Michael [Los Alamos National Laboratory; Griego, Jeffrey Randall [Los Alamos National Laboratory; Turchi, Peter John [Los Alamos National Laboratory; Reinovsky, Robert Emil [Los Alamos National Laboratory; Bradley, Joseph Thomas [Los Alamos National Laboratory; Cheng, Baolian [Los Alamos National Laboratory; Freeman, Matthew Stouten [Los Alamos National Laboratory; Patten, Austin Randall [Los Alamos National Laboratory

2016-03-21

There is great interest in the behavior of the free surface of tin under shock loading. While it is known that meso-scale surface imperfections can seed the Richtmyer- Meshkov Instability (RMI) for a surface that is melted on release, much less is known about a tin surface that is solid, but plastically deforming. Here material properties such as shear and yield strength come into play especially in converging geometry. Previous experiments have been driven by direct contact HE. Usually a thin, flat target coupon is fielded with various single-mode, sinusoidal, machined, profiles on the free surface. The free surface is adjacent to either vacuum or an inert receiver gas. Most of these previous driver/target configurations have been nominal planer geometry. With modern HE it has been straightforward to shock tin into melt on release. However it has been challenging to achieve a low enough pressure for solid state on release. Here we propose to extend the existing base of knowledge to include the behavior of the free surface of tin in cylindrical converging geometry. By shock loading a cylindrical tin shell with a magnetically driven cylindrical liner impactor, the free surface evolution can be diagnosed with proton radiography. With the PHELIX capacitor bank, the drive can easily be varied to span the pressure range to achieve solid, mixed, and liquid states on release. A conceptual cylindrical liner and target is shown in Figure 1.

Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy – Case report

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Jianlin Tang

2014-12-01

Conclusion: The lessons we learned are (1 Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2 Synthetic graft is an alternative for internal jugular vein graft. (3 Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4 It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival.

Vein visualization: patient characteristic factors and efficacy of a new infrared vein finder technology.

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Chiao, F B; Resta-Flarer, F; Lesser, J; Ng, J; Ganz, A; Pino-Luey, D; Bennett, H; Perkins, C; Witek, B

2013-06-01

We investigated the patient characteristic factors that correlate with identification of i.v. cannulation sites with normal eyesight. We evaluated a new infrared vein finding (VF) technology device in identifying i.v. cannulation sites. Each subject underwent two observations: one using the conventional method (CM) of normal, unassisted eyesight and the other with the infrared VF device, VueTek's Veinsite™ (VF). A power analysis for moderate effect size (β=0.95) required 54 samples for within-subject differences. Patient characteristic profiles were obtained from 384 subjects (768 observations). Our sample population exhibited an overall average of 5.8 [95% confidence interval (CI) 5.4-6.2] veins using CM. As a whole, CM vein visualization were less effective among obese [4.5 (95% CI 3.8-5.3)], African-American [4.6 (95% CI 3.6-5.5 veins)], and Asian [5.1 (95% CI 4.1-6.0)] subjects. Next, the VF technology identified an average of 9.1 (95% CI 8.6-9.5) possible cannulation sites compared with CM [average of 5.8 (95% CI 5.4-6.2)]. Seventy-six obese subjects had an average of 4.5 (95% CI 3.8-5.3) and 8.2 (95% CI 7.4-9.1) veins viewable by CM and VF, respectively. In dark skin subjects, 9.1 (95% CI 8.3-9.9) veins were visible by VF compared with 5.4 (95% CI 4.8-6.0) with CM. African-American or Asian ethnicity, and obesity were associated with decreased vein visibility. The visibility of veins eligible for cannulation increased for all subgroups using a new infrared device.

Palliative treatment of TIPS to portal vein tumor thrombosis complicated with portal vein hypertension

International Nuclear Information System (INIS)

Jiang Zaibo; Shan Hong; Guan Shouhai; Zhu Kangshun; Huang Mingsheng; Li Zhengran; Guo Tiansheng; Liu Lang

2002-01-01

Objective: To evaluate the palliative therapeutic effects of transjugular intrahepatic portosystemic shunt (TIPS) in portal vein tumor thrombosis (PVTT) complicated with portal vein hypertension, and to discuss the technical skills. Methods: There were 14 cases of end-stage hepatocellular carcinoma complicated with PVTT and portal vein hypertension, the average age was 53.6 yr. There were 8 cases with complete occlusion of main portal vein, 6 eases with incomplete thrombosis, and 5 cases combined with portal vein cavernous transformation. One case had simple hemorrhage, 3 eases had intractable ascites, and 10 cases had hemorrhage accompanied by intractable ascites. Results: The procedure of TIPS was successful in 10 cases, the successful rate was about 71%. The mean portal vein pressure was reduced from 37.2 mm Hg to 18.2 mm Hg, with an average reduction of 19.0 mm Hg. After the procedure of TIPS, the ascites decreased, hemorrhage stopped and the clinical symptoms disappeared. The average survival period was 132.3 days. The procedure were failing in 4 cases. Conclusion: TIPS was an effective palliative therapeutic methods to control the hemorrhage and ascites aroused by hepatic carcinoma complicated with PVTT

SPHERICAL MICROPARTICLES FROM GOLD–BEARING QUARTZ VEINS OF THE IROKINDA DEPOSIT, WESTERN TRANSBAIKALIA

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A. V. Tatarinov

2016-01-01

.The consequence of metamorphism, i.e. deformational or mechano-chemical transformations of rocks in Irokinda, as well as the autochthon (the rock bed of the Kelyano-Irokinda belt, is the gas-water (‘hydrothermal’ system capable of forming the spherical ore particles with low-temperature mineral rims.The main feature of the structure of the spherical microparticles in Irokinda is a sharp contrast of the crystallization conditions of the metal nodes and their rims. Similar conditions leading to formation of contrasting mineral associations, that are similar in compositions to the discussed spherules, are characteristic of the gas-water-lithoclastitic and gas-water stages of mud volcanoes. For these stages, we suggest the cavitation mechanism of formation of spherical metal particles of Fe, Fe–Cr and other compositions, which is accompanied by combustion (pyrogenic melt and pyrolysis of hydrocarbon components of the fluid. This mechanism, with the exception of the origin of the melt (in this case, of the friction type seems to most closely correspond to the actual data.  The spheroids are likely to have formed in the pre-ore stage of formation of the quartz veins.The high-temperature metal spherical microparticles revealed in our study can be regarded as specific indicators showing conditions in which the ore-forming system of the dynamo-metamorphic type was functioning to produce gold mineralization on the Irokinda deposit. The structure and composition of these microparticles differ from those of the microspherules from other gold deposits in Transbaikalia (black shale formation in Sukhoi Log, and low–sulphide gold–quartz ore formation in Pervenets, which also belong to the dynamogenic genetic type. However, the ore-forming systems of the compared deposits have two common factors that contribute to formation of spherical microparticles – high tectonic activity manifested by repeated (impulse-type tectonic movements, and the associated unstable pressure conditions. The

Concerns and Discomforts of Pregnancy - Varicose Veins

Science.gov (United States)

Concerns and Discomforts of Pregnancy - Varicose Veins Varicose veins are enlarged veins you may see on your ... Healthy Roads Media project www. healthyroadsmedia. org English - Concerns and Discomforts of Pregnancy (Varicose Veins) Last reviewed ...

Highly CO2-supersaturated melts in the Pannonian lithospheric mantle - A transient carbon reservoir?

Science.gov (United States)

Créon, Laura; Rouchon, Virgile; Youssef, Souhail; Rosenberg, Elisabeth; Delpech, Guillaume; Szabó, Csaba; Remusat, Laurent; Mostefaoui, Smail; Asimow, Paul D.; Antoshechkina, Paula M.; Ghiorso, Mark S.; Boller, Elodie; Guyot, François

2017-08-01

Subduction of carbonated crust is widely believed to generate a flux of carbon into the base of the continental lithospheric mantle, which in turn is the likely source of widespread volcanic and non-volcanic CO2 degassing in active tectonic intracontinental settings such as rifts, continental margin arcs and back-arc domains. However, the magnitude of the carbon flux through the lithosphere and the budget of stored carbon held within the lithospheric reservoir are both poorly known. We provide new constraints on the CO2 budget of the lithospheric mantle below the Pannonian Basin (Central Europe) through the study of a suite of xenoliths from the Bakony-Balaton Highland Volcanic Field. Trails of secondary fluid inclusions, silicate melt inclusions, networks of melt veins, and melt pockets with large and abundant vesicles provide numerous lines of evidence that mantle metasomatism affected the lithosphere beneath this region. We obtain a quantitative estimate of the CO2 budget of the mantle below the Pannonian Basin using a combination of innovative analytical and modeling approaches: (1) synchrotron X-ray microtomography, (2) NanoSIMS, Raman spectroscopy and microthermometry, and (3) thermodynamic models (Rhyolite-MELTS). The three-dimensional volumes reconstructed from synchrotron X-ray microtomography allow us to quantify the proportions of all petrographic phases in the samples and to visualize their textural relationships. The concentration of CO2 in glass veins and pockets ranges from 0.27 to 0.96 wt.%, higher than in typical arc magmas (0-0.25 wt.% CO2), whereas the H2O concentration ranges from 0.54 to 4.25 wt.%, on the low end for estimated primitive arc magmas (1.9-6.3 wt.% H2O). Trapping pressures for vesicles were determined by comparing CO2 concentrations in glass to CO2 saturation as a function of pressure in silicate melts, suggesting pressures between 0.69 to 1.78 GPa. These values are generally higher than trapping pressures for fluid inclusions

Corrosion cast study of the canine hepatic veins.

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Uršič, M; Vrecl, M; Fazarinc, G

2014-11-01

This study presents a detailed description of the distribution, diameters and drainage patterns of hepatic veins on the basis of the corrosion cast analysis in 18 dogs. We classified the hepatic veins in three main groups: the right hepatic veins of the caudate process and right lateral liver lobe, the middle hepatic veins of the right medial and quadrate lobes and the left hepatic veins of both left liver lobes and the papillary process. The corrosion cast study showed that the number of the veins in the Nomina Anatomica Veterinaria and most anatomical textbooks is underestimated. The number of various-sized hepatic veins of the right liver division ranged from 3 to 5 and included 1 to 4 veins from the caudate process and 2 to 4 veins from the right lateral liver lobe. Generally, in all corrosion casts, one middle-sized vein from the right part of the right medial lobe, which emptied separately in the caudal vena cava, was established. The other vein was a large-sized vein from the remainder of the central division, which frequently joined the common left hepatic vein from the left liver lobes. The common left hepatic vein was the largest of all the aforementioned hepatic veins.

Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

Directory of Open Access Journals (Sweden)

Young Ho Park

2012-10-01

Full Text Available On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger-vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger-vein recognition is advantageous in that it involves the use of inexpensive and small devices that are difficult to counterfeit. In general, finger-vein recognition systems capture images by using near infrared (NIR illumination in conjunction with a camera. However, such systems can face operational difficulties, since the scattering of light from the skin can make capturing a clear image difficult. To solve this problem, we proposed new image quality enhancement method that measures the direction and thickness of vein lines. This effort represents novel research in four respects. First, since vein lines are detected in input images based on eight directional profiles of a grey image instead of binarized images, the detection error owing to the non-uniform illumination of the finger area can be reduced. Second, our method adaptively determines a Gabor filter for the optimal direction and width on the basis of the estimated direction and thickness of a detected vein line. Third, by applying this optimized Gabor filter, a clear vein image can be obtained. Finally, the further processing of the morphological operation is applied in the Gabor filtered image and the resulting image is combined with the original one, through which finger-vein image of a higher quality is obtained. Experimental results from application of our proposed image enhancement method show that the equal error rate (EER of finger-vein recognition decreases to approximately 0.4% in the case of a local binary pattern-based recognition and to approximately 0.3% in the case of a wavelet transform

Normal hepatic vein patterns on ultrasound

International Nuclear Information System (INIS)

Kim, Hae Jin; Chae, Yoo Soon; Park, Hea Yeoung; Park, Bok Hwan; Kim, Yang Sook

1987-01-01

Understanding of the anatomy of the hepatic vein is important in manipulation for transplantation of the liver, hepatectomy and the treatment of hepatic trauma with avulsion of the hepatic vein. Demonstrated of the inferior right hepatic vein (IRHV) is also important; in some cases of hepatocellular carcinoma, thrombus can be seen in the IRHV; in primary Budd-Chiari syndrome, the IRHV is main draining vein; during hepatectomy, the postero-inferior segment of the right lobe and draining IRHV can be preserved. For some 10 months ultrasound examination was done in a total of 124 patients with normal liver function with special emphasis on the hepatic vein, their branches, and the IRHV, and analysed in terms of branching pattern and relative size of the hepatic vein and the detection rate of the IRHV.

Low-temperature magnetic study of naturally and experimentally shocked pyrrhotite

Science.gov (United States)

Mang, C.; Kontny, A. M.; Hecht, L.

2011-12-01

The most intriguing observation from the suevite unit of the 35 Ma old Chesapeake Bay impact structure (CBIS), Virginia, USA, is the occurrence of "shocked pyrrhotite", which might provide clues for a better understanding of the acquisition of shock-induced remagnetization during an impact event. A large range of differently strong deformed and melted components are mixed in the suevite and maximum shock pressures up to 35 GPa are reported (Wittmann et al. 2009). Pyrrhotite occurs as grains and grain clusters within the suevite matrix and rarely in melt fragments, and abundant lattice defects in pyrrhotite prove a shock-induced deformation. The shocked mineral is characterized by a significant loss of iron and the stoichiometric formula lies between Fe0.808S and Fe0.811S. This composition falls significantly below the Fe/S ratio of regular pyrrhotite (Fe>0.875) and is similar to the one of smythite (Fe9S11). The Curie temperature (TC) is above that of the ferrimagnetic 4C modification (320°C) and lies between 350 and 365°C. However, a transition at 30 K (Rochette et al. 1990), visible in low temperature remanence curves, confirms the presence of ferrimagnetic monoclinic 4C pyrrhotite.The present work aims at the question if all these different features observed in the natural pyrrhotite from the CBIS suevite are impact-related. Therefore we experimentally shocked a pyrrhotite ore from the Cerro de Pasco mine, Peru at 3, 5, 8, 20 and 30 GPa using a high pressure gun and high explosive devices. The obtained samples have been investigated by low-temperature AC susceptibility and remanence measurements (LT). In addition, we determined TC using AC susceptibility as function of temperature. LT experiments of the pyrrhotite ore unfortunately do not only show magnetic transition temperatures related to pure pyrrhotite but additionally of accessory magnetic mineral phases like magnetite (Fe3O4) and pyrophanite (MnTiO3). The contribution of those phases makes especially

The umbilical and paraumbilical veins of man.

Science.gov (United States)

Martin, B F; Tudor, R G

1980-03-01

During its transit through the umbilicus structural changes occur in the thick wall of the extra-abdominal segment of the umbilical vein whereby the components of the intra-abdominal segment acquire an essentially longitudinal direction and become arranged in fibro-elastic and fibro-muscular zones. The vein lumen becomes largely obliterated by asymmetrical proliferation of loose subendothelial conective tissue. The latter forms a new inner zone within which a small segment of the lumen persists in an eccentric position. This residual lumen transmits blood to the portal system from paraumbilical and systemic sources, and is retained in the upper part of the vein, even in old age. A similar process of lumen closure is observed in the ductus venosus. In early childhood the lower third of the vein undergoes breakdown, with fatty infiltration, resulting in its complete division into vascular fibro-elastic strands, and in old age some breakdown occurs in the outermost part of the wall of the upper two thirds. The paraumbilical veins are thick-walled and of similar structure to the umbilical vein. Together they constitute an accessory portal system which is confined between the layers of the falciform ligament and is in communication with the veins of the ventral abdominal wall. The constituents form an ascending series, namely, Burow's veins, the umbilical vein, and Sappey's inferior and superior veins. The main channel of Sappey's inferior veins may be the remnant of the right umbilical vein since it communicates with the right rectus sheath and often communicates directly with the portal system within the right lobe of the liver. The results are of significance in relation to clinical usage of the umbilical vein.

Idiopathic Bilateral External Jugular Vein Thrombosis.

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Hindi, Zakaria; Fadhel, Ehab

2015-08-20

Vein thrombosis is mainly determined by 3 factors, which constitute a triad called Virchow's triad: hypercoagulability, stasis, and endothelial injury. Venous thrombosis commonly occurs in the lower extremities since most of the blood resides there and flows against gravity. The veins of the lower extremities are dependent on intact valves and fully functional leg muscles. However, in case of valvular incompetency or muscular weakness, thrombosis and blood stasis will occur as a result. In contrast, the veins of the neck, specially the jugulars, have distensible walls which allow flexibility during respiration. In addition, the blood directly flows downward towards the heart. Nevertheless, many case reports mentioned the thrombosis of internal jugular veins and external jugular veins with identified risk factors. Jugular vein thrombosis has previously been associated in the literature with a variety of medical conditions, including malignancy. This report is of a case of idiopathic bilateral external jugular vein thrombosis in a 21 year-old male construction worker of Southeast Asian origin with no previous medical history who presented with bilateral facial puffiness of gradual onset over 1 month. Doppler ultrasound and computed tomography were used in the diagnosis. Further work-up showed no evidence of infection or neoplasia. The patient was eventually discharged on warfarin. The patient was assessed after 6 months and his symptoms had resolved completely. Bilateral idiopathic external jugular veins thrombosis is extremely rare and can be an indicator of early malignancy or hidden infection. While previous reports in the literature have associated jugular vein thrombosis with malignancy, the present case shows that external jugular vein thrombosis can also be found in persons without malignancy.

Noninvasive optoacoustic system for rapid diagnosis and management of circulatory shock

Science.gov (United States)

Petrov, Irene Y.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. N.; Seeton, Roger; Esenaliev, Rinat O.; Prough, Donald S.

2013-03-01

Circulatory shock can lead to death or severe complications, if not promptly diagnosed and effectively treated. Typically, diagnosis and management of circulatory shock are guided by blood pressure and heart rate. However, these variables have poor specificity, sensitivity, and predictive value. Early goal-directed therapy in septic shock patients, using central venous catheterization (CVC), reduced mortality from 46.5% to 30%. However, CVC is invasive and complication-prone. We proposed to use an optoacoustic technique for noninvasive, rapid assessment of peripheral and central venous oxygenation. In this work we used a medical grade optoacoustic system for noninvasive, ultrasound image-guided measurement of central and peripheral venous oxygenation. Venous oxygenation during shock declines more rapidly in the periphery than centrally. Ultrasound imaging of the axillary [peripheral] and internal jugular vein [central] was performed using the Vivid e (GE Healthcare). We built an optoacoustic interface incorporating an optoacoustic transducer and a standard ultrasound imaging probe. Central and peripheral venous oxygenations were measured continuously in healthy volunteers. To simulate shock-induced changes in central and peripheral oxygenation, we induced peripheral vasoconstriction in the upper extremity by using a cooling blanket. Central and peripheral venous oxygenations were measured before (baseline) and after cooling and after rewarming. During the entire experiment, central venous oxygenation was relatively stable, while peripheral venous oxygenation decreased by 5-10% due to cooling and recovered after rewarming. The obtained data indicate that noninvasive, optoacoustic measurements of central and peripheral venous oxygenation may be used for diagnosis and management of circulatory shock with high sensitivity and specificity.

Blood sampling from adrenal gland vein

International Nuclear Information System (INIS)

Sun Yong; Ni Caifang

2009-01-01

Adrenal gland vein sampling is an interventional method to get the blood samples from the adrenal gland vein. The blood is obtained via a catheter which is selectively inserted in the adrenal gland vein. This technique is mainly used to be diagnostic for primary hyperaldosteronism. A full knowledge of the anatomy and variations of the adrenal gland vein, serious preoperative preparation and skilled catheterization manipulation are necessary for obtaining sufficient blood sample and for reducing the occurrence of complications. Providing the physicians with definite diagnostic evidence and being technically feasible, adrenal gland vein sampling should become one of the routine examinations for clarifying the cause of primary hyperaldosteronism. (authors)

Isolated inferior mesenteric portal hypertension with giant inferior mesenteric vein and anomalous inferior mesenteric vein insertion

Directory of Open Access Journals (Sweden)

G Raghavendra Prasad

2013-01-01

Full Text Available Extrahepatic portal hypertension is not an uncommon disease in childhood, but isolated inferior mesenteric portal varices and lower gastrointestinal (GI bleed have not been reported till date. A 4-year-old girl presented with lower GI bleed. Surgical exploration revealed extrahepatic portal vein obstruction with giant inferior mesenteric vein and colonic varices. Inferior mesenteric vein was joining the superior mesenteric vein. The child was treated successfully with inferior mesenteric - inferior vena caval anastomosis. The child was relieved of GI bleed during the follow-up.

Multimodal ultrasonographic assessment of leiomyosarcoma of the femoral vein in a patient misdiagnosed as having deep vein thrombosis

Science.gov (United States)

Zhang, Mei; Yan, Feng; Huang, Bin; Wu, Zhoupeng; Wen, Xiaorong

2017-01-01

Abstract Rationale: Primary leiomyosarcoma (LMS) of the vein is a rare tumor that arises from the smooth muscle cells of the vessel wall and has an extremely poor prognosis. This tumor can occur in vessels such as the inferior vena cava, great saphenous vein, femoral vein, iliac vein, popliteal vein, and renal vein; the inferior vena cava is the most common site. LMS of the femoral vein can result in edema and pain in the lower extremity; therefore, it is not easy to be differentiated from deep vein thrombosis (DVT). Moreover, virtually no studies have described the ultrasonographic features of LMS of the vein in detail. Patient concerns: We present a case of a 55-year-old woman with LMS of the left femoral vein that was misdiagnosed as having deep vein thrombosis (DVT) on initial ultrasonographic examination. The patient began to experience edema and pain in her left leg seven months previously. She was diagnosed as having DVT on initial ultrasonographic examination, but the DVT treatment that she had received for 7 months failed to improve the status of her left lower limb. Diagnoses: She subsequently underwent re-examination by means of a multimodal ultrasonographic imaging approach (regular B-mode imaging, color Doppler imaging, pulsed-wave Doppler imaging, contrast-enhanced ultrasonography), which confirmed a diagnosis of LMS. Interventions: This patient was treated successfully with surgery. Outcomes: This case demonstrates that use of multiple ultrasonographic imaging techniques can be helpful to diagnose LMS accurately. Detection of vasculature in a dilated vein filled with a heterogeneous hypoechoic substance on ultrasonography is a sign of a tumor. Lessons: The pitfall of misdiagnosing this tumor as DVT is a useful reminder. PMID:29145269

Duplex sonography of the near-surface leg veins

International Nuclear Information System (INIS)

Mendoza, E.

2007-01-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins

Self-taught axillary vein access without venography for pacemaker implantation: prospective randomized comparison with the cephalic vein access.

Science.gov (United States)

Squara, Fabien; Tomi, Julien; Scarlatti, Didier; Theodore, Guillaume; Moceri, Pamela; Ferrari, Emile

2017-12-01

Axillary vein access for pacemaker implantation is uncommon in many centres because of the lack of training in this technique. We assessed whether the introduction of the axillary vein technique was safe and efficient as compared with cephalic vein access, in a centre where no operators had any previous experience in axillary vein puncture. Patients undergoing pacemaker implantation were randomized to axillary or cephalic vein access. All three operators had no experience nor training in axillary vein puncture, and self-learned the technique by reading a published review. Axillary vein puncture was fluoroscopy-guided without contrast venography. Cephalic access was performed by dissection of delto-pectoral groove. Venous access success, venous access duration (from skin incision to guidewire or lead in superior vena cava), procedure duration, X-ray exposure, and peri-procedural (1 month) complications were recorded. results We randomized 74 consecutive patients to axillary (n = 37) or cephalic vein access (n = 37). Axillary vein was successfully accessed in 30/37 (81.1%) patients vs. 28/37 (75.7%) of cephalic veins (P = 0.57). Venous access time was shorter in axillary group than in cephalic group [5.7 (4.4-8.3) vs. 12.2 (10.5-14.8) min, P < 0.001], as well as procedure duration [34.8 (30.6-38.4) vs. 42.0 (39.1-46.6) min, P = 0.043]. X-ray exposure and peri-procedural overall complications were comparable in both groups. Axillary puncture was safe and faster than cephalic access even for the five first procedures performed by each operator. Self-taught axillary vein puncture for pacemaker implantation seems immediately safe and faster than cephalic vein access, when performed by electrophysiologists trained to pacemaker implantation but not to axillary vein puncture. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.

Temperature and pressure determination of the tin melt boundary from a combination of pyrometry, spectral reflectance, and velocity measurements along release paths

Science.gov (United States)

La Lone, Brandon; Asimow, Paul; Fatyanov, Oleg; Hixson, Robert; Stevens, Gerald

2017-06-01

Plate impact experiments were conducted on tin samples backed by LiF windows to determine the tin melt curve. Thin copper flyers were used so that a release wave followed the 30-40 GPa shock wave in the tin. The release wave at the tin-LiF interface was about 300 ns long. Two sets of experiments were conducted. In one set, spectral emissivity was measured at six wavelengths using a flashlamp illuminated integrating sphere. In the other set, thermal radiance was measured at two wavelengths. The emissivity and thermal radiance measurements were combined to obtain temperature histories of the tin-LiF interface during the release. PDV was used to obtain stress histories. All measurements were combined to obtain temperature vs. stress release paths. A kink or steepening in the release paths indicate where the releases merge onto the melt boundary, and release paths originating from different shock stresses overlap on the melt boundary. Our temperature-stress release path measurements provide a continuous segment of the tin melt boundary that is in good agreement with some of the published melt curves. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy, and supported by the Site-Directed Research and Development Program. DOE/NV/259463133.

Progade PT path, prograde fluid flow, metasomatism and hydrous melting in the Osor high-grade HT-LP complex (Catalan Coastal Ranges-CCR, NE Iberia).

Science.gov (United States)

Reche, Joan; Martínez, Francisco; Leoz, Gisela

2015-04-01

Fast thermal pulses related to HT-LP metamorphism may imply dehydration reaction overstepping, higher than normal fluid production rates, quick local increases in Pfluid and common situations of Pfluid >> Plitostatic and surpassing locally the tensile stresses. This ambient would be favorable to transient hydrofracturing and fluid flow even if the ongoing HT-LP event develops on dominantly ductile crustal levels. In inner zones where temperatures are high enough, hydrous melting and melt migration would be favored as well. Such movement of fluids and melts would tend to be sustained if non-hydrostatic stresses are active during heating, and would be favored in high strain domains such high-T shear zones or along foliation planes. In such scenario, local metasomatic processes and mass-transfer phenomena are expected to occur along these high strain zones and so distributed along tectonic anisotropies. A variety of features found in high T Garnet - biotite-sillimanite±cordierite±plagioclase±K-feldspar±quartz metapelitic gneisses from the Osor Complex (Guilleries massif, CCR), testify from this kind of processes operating in the lower crustal section, at the amphibolite to granulite transition zone during a prograde Variscan HT-LP thermal pulse. Such features include: syn-D2 quartz veining, leucogranitoid (leucotonalite, trondhjemitic) lenses sub parallel to S2 dominant foliation, fibrolite-rich foliation planes and prograde sub-idiomorphic garnet developing preferentially near fluid migration channels (quartz veins) or near melt lenses.

Portal vein thrombosis.

Science.gov (United States)

Chawla, Yogesh K; Bodh, Vijay

2015-03-01

Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

Case report: Varicosity of the communicating vein between the left renal vein and the left ascending lumbar vein mimicking a renal artery aneurysm: Report of an unusual site of varicose veins and a novel hypothesis to explain its association with abdominal pain

Directory of Open Access Journals (Sweden)

Sandeep G Jakhere

2011-01-01

Full Text Available A communicating vein between the left renal vein and the left ascending lumbar vein has only rarely been reported in the imaging literature. There are very few reports of varicosity of this communicating vein. Nonetheless, awareness about this communicating vein is of utmost importance for surgeons performing aortoiliac surgeries and nephrectomies as it may pose technical difficulties during surgery or cause life-threatening retroperitoneal hemorrhage. Varicosity of this venous channel may be mistaken for paraaortic lymphadenopathy, adrenal pseudo-mass, or renal artery aneurysm. We report a case of a patient with varicosity of this communicating vein, which mimicked a left renal artery aneurysm. A novel hypothesis is also proposed to explain the relationship with abdominal pain.

Petrological Geodynamics of Mantle Melting II. AlphaMELTS + Multiphase Flow: Dynamic Fractional Melting

Science.gov (United States)

Tirone, Massimiliano

2018-03-01

In this second installment of a series that aims to investigate the dynamic interaction between the composition and abundance of the solid mantle and its melt products, the classic interpretation of fractional melting is extended to account for the dynamic nature of the process. A multiphase numerical flow model is coupled with the program AlphaMELTS, which provides at the moment possibly the most accurate petrological description of melting based on thermodynamic principles. The conceptual idea of this study is based on a description of the melting process taking place along a 1-D vertical ideal column where chemical equilibrium is assumed to apply in two local sub-systems separately on some spatial and temporal scale. The solid mantle belongs to a local sub-system (ss1) that does not interact chemically with the melt reservoir which forms a second sub-system (ss2). The local melt products are transferred in the melt sub-system ss2 where the melt phase eventually can also crystallize into a different solid assemblage and will evolve dynamically. The main difference with the usual interpretation of fractional melting is that melt is not arbitrarily and instantaneously extracted from the mantle, but instead remains a dynamic component of the model, hence the process is named dynamic fractional melting (DFM). Some of the conditions that may affect the DFM model are investigated in this study, in particular the effect of temperature, mantle velocity at the boundary of the mantle column. A comparison is made with the dynamic equilibrium melting (DEM) model discussed in the first installment. The implications of assuming passive flow or active flow are also considered to some extent. Complete data files of most of the DFM simulations, four animations and two new DEM simulations (passive/active flow) are available following the instructions in the supplementary material.

Interventional treatment of iliac vein compression syndrome

International Nuclear Information System (INIS)

Li Xiaoqiang; Zhou Weiming; Nie Zhonglin; Yu Chaowen

2002-01-01

Objective: To explore the clinical significance of interventional treatment of iliac vein compression syndrome (IVCS). Methods: Percutaneous transluminal angioplasty (PTA) was performed in 40 cases. Thirty-three cases underwent endovascular stent implantation and 27 cases underwent second-stage left saphenous vein ligation and stripping and the valves of left femoral veins narrowing. Thirty-one cases were followed-up postoperatively and the duration was 6-66 months (mean 28 months). Results: The dilation of iliac veins was successful in 36 cases and there were god efficacy in all patients when they discharged from hospital. Followed-up during post-operation, all the limbs ulcers were cured and varicose veins disappeared. The skin pigmentation disappeared in 17 of 19 cases and markedly relieved in 2 cases. Left lower limb swelling disappeared in 15 of 17 cases and relieved in 2 cases. Conclusion: There is good efficacy in the interventional treatment of left iliac vein lesions, but second-stage procedures should be performed in secondary lesions of saphenous veins and valves of femoral veins

Density Determination of Metallic Melts from Diffuse X-Ray Scattering

Science.gov (United States)

Brauser, N.; Davis, A.; Greenberg, E.; Prakapenka, V. B.; Campbell, A.

2017-12-01

Liquids comprise several important structural components of the deep Earth, for example, the present outer core and a hypothesized magma ocean early in Earth history. However, the physical properties of the constituent materials of these structures at high pressures and temperatures are less well constrained than their crystalline counterparts. Determination of the physical properties of these liquids can inform geophysical models of the composition and structure of the Earth, but methods for studying the physical properties of liquids at high pressure and temperatures are underdeveloped. One proposed method for direct determination of density of a melt requires analysis of the diffuse scattered X-ray signal of the liquid. Among the challenges to applying this technique to high-pressure melts within a laser heated diamond anvil cell are the low signal-to-noise ratio and overlapping diffraction peaks from the crystalline components of the sample assembly interfering with the diffuse scattering from the liquid. Recent advances in instrumentation at synchrotron X-ray sources have made this method more accessible for determination of density of melted material. In this work we present the technique and report the densities of three high-pressure melts of the FCC metals iron, nickel, and gold derived from diffuse scattered X-ray spectra collected from in situ laser-heated diamond anvil cell synchrotron experiments. The results are compared to densities derived from shock wave experiments.

The angiographic demonstration of hepatic vein obstruction

International Nuclear Information System (INIS)

Zu Maoheng; Xu Hao; Li Guojun; Gu Yuming; Wei Ning; Wang Cheng; Xu Wei

2004-01-01

Objective: To evaluate the angiographic feature of hepatic vein obstruction. Methods Forty-five patients (male 23, female 22, age 9-54 years) suffered from hepatic vein obstruction. The inferior vena cavography and the hepatic venography were performed in all cases. Results: IVC was free in 37 patients with hepatic vein obstruction, both IVC and HV were obstructed in 8 patients. The local or long stenosis of IVC was found in 31 inferior vena cavography. The diameter of IVC was normal in 12 patients. The sign of membranous dome was found in hepatic vein orifice in 5 cases and in accessory hepatic vein orifice in 4 cases. Intrahepatic venous collaterals were found in 45 cases. Conclusion: Hepatic vein obstruction can be reproached primarily in inferior vena cavography, the membranous dome is a direct sign of membranous obstruction of HV and AHV in inferior vena cavography. The selected hepatic venography can provide reliable evidence to diagnose hepatic vein obstruction

A Vein Map Biometric System

Directory of Open Access Journals (Sweden)

Felix Fuentes

2013-08-01

Full Text Available There is increasing demand world-wide, from government agencies and the private sector for cutting-edge biometric security technology that is difficult to breach but userfriendly at the same time. Some of the older tools, such as fingerprint, retina and iris scanning, and facial recognition software have all been found to have flaws and often viewed negatively because of many cultural and hygienic issues associated with them. Comparatively, mapping veins as a human barcode, a new technology, has many advantages over older technologies. Specifically, reproducing a three-dimensional model of a human vein system is impossible to replicate. Vein map technology is distinctive because of its state-of-the-art sensors are only able to recognize vein patterns if hemoglobin is actively flowing through the person

Yield strength measurement of shock-loaded metal by flyer-impact perturbation method

Science.gov (United States)

Ma, Xiaojuan; Shi, Zhan

2018-06-01

Yield strength is one of the most important physical properties of a solid material, especially far from its melting line. The flyer-impact perturbation method measures material yield strength on the basis of correlation between the yield strength under shock compression and the damping of oscillatory perturbations in the shape of a shock front passing through the material. We used flyer-impact experiments on targets with machined grooves on the impact surface of shock 6061-T6 aluminum to between 32 and 61 GPa and recorded the evolution of the shock front perturbation amplitude in the sample with electric pins. Simulations using the elastic-plastic model can be matched to the experiments, explaining well the form of the perturbation decay and constraining the yield strength of 6061-T6 aluminum to be 1.31-1.75 GPa. These results are in agreement with values obtained from reshock and release wave profiles. We conclude that the flyer-impact perturbation method is indeed a new means to measure material strength.

GLASS MELTING PHENOMENA, THEIR ORDERING AND MELTING SPACE UTILISATION

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Němec L.

2013-12-01

Full Text Available Four aspects of effective glass melting have been defined – namely the fast kinetics of partial melting phenomena, a consideration of the melting phenomena ordering, high utilisation of the melting space, and effective utilisation of the supplied energy. The relations were defined for the specific melting performance and specific energy consumption of the glass melting process which involve the four mentioned aspects of the process and indicate the potentials of effective melting. The quantity “space utilisation” has been treated in more detail as an aspect not considered in practice till this time. The space utilisation was quantitatively defined and its values have been determined for the industrial melting facility by mathematical modelling. The definitions of the specific melting performance and specific energy consumption have been used for assessment of the potential impact of a controlled melt flow and high space utilisation on the melting process efficiency on the industrial scale. The results have shown that even the partial control of the melt flow, leading to the partial increase of the space utilisation, may considerably increase the melting performance, whereas a decrease of the specific energy consumption was determined to be between 10 - 15 %.

Deep vein thrombosis of the leg

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun Hee; Rhee, Kwang Woo; Jeon, Suk Chul; Joo, Kyung Bin; Lee, Seung Ro; Seo, Heung Suk; Hahm, Chang Kok [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

1987-04-15

Ascending contrast venography is the definitive standard method for the diagnosis of deep vein thrombosis (DVT) of the lower extremities. Authors analysed 22 cases of DVT clinically and radiographically. 1.The patients ranged in age from 15 to 70 yrs and the most prevalent age group was 7th decade (31%). There was an equal distribution of males and females. 2.In 11 cases of 22 cases, variable etiologic factors were recognized, such as abdominal surgery, chronic bedridden state, local trauma on the leg, pregnancy, postpartum, Behcet's syndrome, iliac artery aneurysm, and chronic medication of estrogen. 3.Nineteen cases out of 22 cases showed primary venographic signs of DVT, such as well-defined filling defect in opacified veins and narrowed, irregularly filled venous lumen. In only 3 cases, the diagnosis of DVT was base upon the segmental nonvisualization of deep veins with good opacification of proximal and distal veins and presence of collaterals. 4.Extent of thrombosis: 3 cases were confined to calf vein, 4 cases extended to femoral vein, and 15 cases had involvement above iliac vein. 5.In 17 cases involving relatively long segment of deep veins, propagation pattern of thrombus was evaluated by its radiologic morphology according to the age of thrombus: 9 cases suggested central or antegrade propagation pattern and 8 cases, peripheral or retrograde pattern. 6.None of 22 cases showed clinical evidence of pulmonary embolism. The cause of the rarity of pulmonary embolism in Korean in presumed to be related to the difference in major involving site and propagation pattern of DVT in the leg.

Deep vein thrombosis of the leg

International Nuclear Information System (INIS)

Lee, Eun Hee; Rhee, Kwang Woo; Jeon, Suk Chul; Joo, Kyung Bin; Lee, Seung Ro; Seo, Heung Suk; Hahm, Chang Kok

1987-01-01

Ascending contrast venography is the definitive standard method for the diagnosis of deep vein thrombosis (DVT) of the lower extremities. Authors analysed 22 cases of DVT clinically and radiographically. 1.The patients ranged in age from 15 to 70 yrs and the most prevalent age group was 7th decade (31%). There was an equal distribution of males and females. 2.In 11 cases of 22 cases, variable etiologic factors were recognized, such as abdominal surgery, chronic bedridden state, local trauma on the leg, pregnancy, postpartum, Behcet's syndrome, iliac artery aneurysm, and chronic medication of estrogen. 3.Nineteen cases out of 22 cases showed primary venographic signs of DVT, such as well-defined filling defect in opacified veins and narrowed, irregularly filled venous lumen. In only 3 cases, the diagnosis of DVT was base upon the segmental nonvisualization of deep veins with good opacification of proximal and distal veins and presence of collaterals. 4.Extent of thrombosis: 3 cases were confined to calf vein, 4 cases extended to femoral vein, and 15 cases had involvement above iliac vein. 5.In 17 cases involving relatively long segment of deep veins, propagation pattern of thrombus was evaluated by its radiologic morphology according to the age of thrombus: 9 cases suggested central or antegrade propagation pattern and 8 cases, peripheral or retrograde pattern. 6.None of 22 cases showed clinical evidence of pulmonary embolism. The cause of the rarity of pulmonary embolism in Korean in presumed to be related to the difference in major involving site and propagation pattern of DVT in the leg

Viscosity measurements on metal melts at high pressure and viscosity calculations for the earth's core

International Nuclear Information System (INIS)

Mineev, Vladimir N; Funtikov, Aleksandr I

2004-01-01

A review is given of experimental and calculated data on the viscosity of iron-based melts on the melting curve. The interest in these data originates in the division of opinion on whether viscosity increases rather moderately or considerably in the high-pressure range. This disagreement is especially pronounced in the interpretation of the values of molten iron and its compounds in the environment of the earth's outer core. The conclusion on a substantial rise in viscosity mostly follows from the universal law, proposed by Brazhkin and Lyapin [1], of viscosity changing along the metal melting curve in the high-pressure range. The review analyzes available experimental and computational data, including the most recent ones. Data on viscosity of metals under shock wave compression in the megabar pressure range are also discussed. It is shown that data on viscosity of metal melts point to a small increase of viscosity on the melting curve. Specifics are discussed of the phase diagram of iron made more complex by the presence of several phase transitions and by the uncertainty in the position of the melting curve in the high-pressure range. Inaccuracies that arise in extrapolating the results of viscosity measurements to the pressure range corresponding to the earth's core environment are pointed out. (reviews of topical problems)

Bilateral meandering pulmonary veins

Energy Technology Data Exchange (ETDEWEB)

Thupili, Chakradhar R.; Udayasankar, Unni [Pediatric Imaging, Imaging Institute Cleveland Clinic, Cleveland, OH (United States); Renapurkar, Rahul [Imaging Institute Cleveland Clinic, Thoracic Imaging, L10, Cleveland, OH (United States)

2015-06-15

Meandering pulmonary veins is a rare clinical entity that can be mistaken for more complex congenital syndromes such as hypogenetic lung syndrome. We report imaging findings in a rare incidentally detected case of bilateral meandering pulmonary veins. We briefly discuss the role of imaging in diagnosing this condition, with particular emphasis on contrast-enhanced CT. (orig.)

The veining phenomenon in unalloyed plutonium

International Nuclear Information System (INIS)

White, J.S.

1976-01-01

An investigation has been made of the veining phenomenon in unalloyed plutonium. The surface markings, or veins, which are sometimes seen on α-phase plutonium samples, arise as a result of the β→α transformation. As far as is known, this veining is unrivalled in its scale and form as compared with the solid state surface transformation effects shown by any other metal. The phenomenon has been explained by the application of the Le Chatelier principle to the phase change. In this instance, the large (10%) volume contraction associated with the β→α reaction and the anisotropy of the nonoclinic α-phase structure, account for the fact that the veins are so prominent in plutonium. On the basis of the proposed model, the veins can only form at temperatures where the transformation mechanism is non-martensitic. (Auth.)

Unusual termination of the right testicular vein | Woldeyes | Anatomy ...

African Journals Online (AJOL)

The testicular veins are formed by the veins emerging from the testis and epididymis forming the pampiniform venous plexus. The right testicular vein drains into inferior vena cava and the left testicular vein to the left renal vein. Testicular veins display a great variability with regard to their number, course and sites of ...

An unusual case: right proximal ureteral compression by the ovarian vein and distal ureteral compression by the external iliac vein

Directory of Open Access Journals (Sweden)

Halil Ibrahim Serin

2015-12-01

Full Text Available A 32-years old woman presented to the emergency room of Bozok University Research Hospital with right renal colic. Multidetector computed tomography (MDCT showed compression of the proximal ureter by the right ovarian vein and compression of the right distal ureter by the right external iliac vein. To the best of our knowledge, right proximal ureteral compression by the ovarian vein together with distal ureteral compression by the external iliac vein have not been reported in the literature. Ovarian vein and external iliac vein compression should be considered in patients presenting to the emergency room with renal colic or low back pain and a dilated collecting system.

Fuel-coolant interaction in a shock tube with initially-established film boiling

International Nuclear Information System (INIS)

Sharon, A.; Bankoff, S.G.

1979-01-01

A new mode of thermal interaction has been employed, in which liquid metal is melted in a crucible within a shock tube; the coolant level is raised to overflow the crucible and establish subcooled film boiling with known bulk metal temperature; and a pressure shock is then initiated. With water and lead-tin alloy an initial splash of metal may be obtained after the vapor film has collapsed, due primarily to thermal interaction, followed by a successive cycle of bubble growth and collapse. To obtain large interactions, the interfacial contact temperature must exceed the spontaneous nucleation temperature of the coolant. Other cutoff behavior is observed with respect to the initial system pressure and temperatures and with the shock pressure and rise time. Experiments with butanol and lead-tin alloy show only relatively mild interactions. Qualitative explanations are proposed for the different behaviors of the two liquids

Shock initiation sensitivity and Hugoniot-based equation of state of Composition B obtained using in situ electromagnetic gauging

International Nuclear Information System (INIS)

Gibson, L L; Bartram, B D; Sheffield, S A; Gustavsen, R L; Brown, G W; Sandstrom, M M; Giambra, A M; Dattelbaum, D M; Handley, C A

2014-01-01

A series of gas gun-driven plate impact experiments were performed on vacuum melt-cast Composition B to obtain new Hugoniot states and shock sensitivity (run-distance-to-detonation) information. The Comp B (ρ 0 = 1.713 g/cm 3 ) consisted of 59.5% RDX, 39.5% TNT, and 1% wax, with ∼ 6.5% HMX in the RDX. The measured Hugoniot states were found to be consistent with earlier reports, with the compressibility on the shock adiabat softer than that of a 63% RDX material reported by Marsh.[4] The shock sensitivity was found to be more sensitive (shorter run distance to detonation at a given shock input condition) than earlier reports for Comp B-3 and a lower density (1.68-1.69 g/cm 3 ) Comp B formulation. The reactive flow during the shock-to-detonation transition was marked by heterogeneous, hot spot-driven growth both in and behind the leading shock front.

Investigation of adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents in the iliac vein: insights into developing a better iliac vein stent.

Science.gov (United States)

Shida, Takuya; Umezu, Mitsuo; Iwasaki, Kiyotaka

2018-06-01

We analyzed the adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents for the treatment of iliac venous thromboembolism and investigated their relationships with the anatomical features of the iliac vein, to gain insights into the development of a better iliac vein stent. Reports of adverse events following the use of stents in the iliac vein were retrieved from the Manufacturer and User Facility Device Experience (MAUDE) database that contain suspected device-associated complications reported to the Food and Drug Administration. Data from 2006 to 2016 were investigated. The literature analysis was also conducted using PubMed, Cochrane Library, EMBASE, and Web of Science focusing on English articles published up to 4 October 2016. The analysis of 88 adverse events from the MAUDE database and 182 articles from the literature revealed that a higher number of adverse events had been reported following the use of arterial stents in the iliac vein compared to CE-marked iliac vein stents. While stent migration and shortening were reported only for the arterial stents, stent fracture and compression occurred regardless of the stent type, even though a vein does not pulsate. A study of the anatomical features of the iliac vein implies that bending, compression, and kink loads are applied to the iliac vein stents in vivo. For designing, developing, and pre-clinical testing of stents intended for use in the iliac vein, the above mechanical load environments induced by the anatomical features should be considered.

Flow Strength of Shocked Aluminum in the Solid-Liquid Mixed Phase Region

Science.gov (United States)

Reinhart, William

2011-06-01

Shock waves have been used to determine material properties under high shock stresses and very-high loading rates. The determination of mechanical properties such as compressive strength under shock compression has proven to be difficult and estimates of strength have been limited to approximately 100 GPa or less in aluminum. The term ``strength'' has been used in different ways. For a Von-Mises solid, the yield strength is equal to twice the shear strength of the material and represents the maximum shear stress that can be supported before yield. Many of these concepts have been applied to materials that undergo high strain-rate dynamic deformation, as in uni-axial strain shock experiments. In shock experiments, it has been observed that the shear stress in the shocked state is not equal to the shear strength, as evidenced by elastic recompressions in reshock experiments. This has led to an assumption that there is a yield surface with maximum (loading)and minimum (unloading), shear strength yet the actual shear stress lies somewhere between these values. This work provides the first simultaneous measurements of unloading velocity and flow strength for transition of solid aluminum to the liquid phase. The investigation describes the flow strength observed in 1100 (pure), 6061-T6, and 2024 aluminum in the solid-liquid mixed phase region. Reloading and unloading techniques were utilized to provide independent data on the two unknowns (τc and τo) , so that the actual critical shear strength and the shear stress at the shock state could be estimated. Three different observations indicate a change in material response for stresses of 100 to 160 GPa; 1) release wave speed (reloading where applicable) measurements, 2) yield strength measurements, and 3) estimates of Poisson's ratio, all of which provide information on the melt process including internal consistency and/or non-equilibrium and rate-dependent melt behavior. The study investigates the strength properties

Preoperative mapping of the saphenous vein

DEFF Research Database (Denmark)

Levi-Mazloum, Niels Donald; Sillesen, H; Nielsen, Tina G

1995-01-01

A consecutive series of 92 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. A naturally occurring optimal vein diameter was discovered. It was significantly correlated with higher postoperative ankle-brachial pres......-brachial pressure index (ABI) and lesser early postoperative thrombosis. A significant linear regression was found between the pre and postoperative vein diameter....

The CT appearance of the superior intercostal veins

International Nuclear Information System (INIS)

Lund, G.

1982-01-01

The CT appearance of the superior intercostal veins is described. The veins are more frequently seen on the right side. The right superior intercostal vein should not be misinterpreted as a paraspinal mass when it is large or bulges into the contour of the right lung. A case of stenosis of the left brachiocephalic vein is shown, where the left superior intercostal vein serves as a collateral. (orig.)

Balloon-occluded retrograde transvenous obliteration of gastric varix draining via the left inferior phrenic vein into the left hepatic vein

International Nuclear Information System (INIS)

Ibukuro, Kenji; Mori, Koichi; Tsukiyama, Toshitaka; Inoue, Yoshihiro; Iwamoto, Yukako; Tagawa, Kazumi

1999-01-01

We encountered a patient with gastric varix draining not via the usual left suprarenal vein but via the left inferior phrenic vein joining the left hepatic vein. Transfemoral balloon-occluded retrograde transvenous obliteration (BRTO) of the varix was performed under balloon occlusion of the left inferior phrenic vein via the left hepatic vein and retrograde injection of the sclerosing agent (5% of ethanolamine oleate) into the gastric varix. Disappearance of the gastric varix was confirmed on endoscopic examination 2 months later.

Eutectic melting temperature of the lowermost Earth's mantle

Science.gov (United States)

Andrault, D.; Lo Nigro, G.; Bolfan-Casanova, N.; Bouhifd, M.; Garbarino, G.; Mezouar, M.

2009-12-01

Partial melting of the Earth's deep mantle probably occurred at different stages of its formation as a consequence of meteoritic impacts and seismology suggests that it even continues today at the core-mantle boundary. Melts are important because they dominate the chemical evolution of the different Earth's reservoirs and more generally the dynamics of the whole planet. Unfortunately, the most critical parameter, that is the temperature profile inside the deep Earth, remains poorly constrained accross the planet history. Experimental investigations of the melting properties of materials representative of the deep Earth at relevant P-T conditions can provide anchor points to refine past and present temperature profiles and consequently determine the degree of melting at the different geological periods. Previous works report melting relations in the uppermost lower mantle region, using the multi-anvil press [1,2]. On the other hand, the pyrolite solidus was determined up to 65 GPa using optical observations in the laser-heated diamond anvil cell (LH-DAC) [3]. Finally, the melting temperature of (Mg,Fe)2SiO4 olivine is documented at core-mantle boundary (CMB) conditions by shock wave experiments [4]. Solely based on these reports, experimental data remain too sparse to draw a definite melting curve for the lower mantle in the relevant 25-135 GPa pressure range. We reinvestigated melting properties of lower mantle materials by means of in-situ angle dispersive X-ray diffraction measurements in the LH-DAC at the ESRF [5]. Experiments were performed in an extended P-T range for two starting materials: forsterite and a glass with chondrite composition. In both cases, the aim was to determine the onset of melting, and thus the eutectic melting temperatures as a function of pressure. Melting was evidenced from drastic changes of diffraction peak shape on the image plate, major changes in diffraction intensities in the integrated pattern, disappearance of diffraction rings

Modeling and evaluation of HE driven shock effects in copper with the MTS model

International Nuclear Information System (INIS)

Murphy, M.J.; Lassila, D.F.

1997-01-01

Many experimental studies have investigated the effect of shock pressure on the post-shock mechanical properties of OFHC copper. These studies have shown that significant hardening occurs during shock loading due to dislocation processes and twinning. It has been demonstrated that when an appropriate initial value of the Mechanical Threshold Stress (MTS) is specified, the post-shock flow stress of OFE copper is well described by relationships derived independently for unshocked materials. In this study we consider the evolution of the MTS during HE driven shock loading processes and the effect on the subsequent flow stress of the copper. An increased post shock flow stress results in a higher material temperature due to an increase in the plastic work. An increase in temperature leads to thermal softening which reduces the flow stress. These coupled effects will determine if there is melting in a shaped charge jet or a necking instability in an EFP Ww. 'Me critical factor is the evolution path followed combined with the 'current' temperature, plastic strain, and strain rate. Preliminary studies indicate that in simulations of HE driven shock with very high resolution zoning, the MTS saturates because of the rate dependence in the evolution law. On going studies are addressing this and other issues with the goal of developing a version of the MT'S model that treats HE driven, shock loading, temperature, strain, and rate effects apriori

The magmatic model for the origin of Archean Au-quartz vein ore systems: an assessment of the evidence

International Nuclear Information System (INIS)

Spooner, E.T.C.

1991-01-01

The magmatic model for the origin of Archean Au-quartz vein ore systems suggests that Au was derived by partition between silicate (± sulphide) melts of certain compositions and H 2 O-CO 2 -NaCl magmatic fluids. Supporting evidence includes partial/structural geological relationships, timing relationships, H and C isotope geochemistry, probable primary Au enrichment in the Lamaque stocks, and fluid inclusion volatile geochemistry. Evidence is currently negative with respect to various within- and sub-greenstone belt metamorphic/deep crustal fluid models for primary Au mineralization; however a U-Pb age for vein stage 3 sphene from the Camflo deposit, Quebec which is ∼ 55-60 Ma younger than the host stock at 2685-2680 Ma indicates dissolution/reprecipitation of Au by late, (?) upper crustal saline fluids. Evidence is accumulating that epithermal-meso thermal Au-Ag mineralization in island arc and cordilleran settings may also have been magmatically derived ± high level fluid mixing from calc-alkaline, shoshonitic and other igneous compositions. (author)

Vein Patch Closure Using Below the Knee Greater Saphenous Vein for Femoral Endarterectomy Procedures is Not Always a Safe Choice

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M. Berner

Full Text Available : Background: The complication of vein patch rupture is well described after carotid patch angioplasty; however, there is a paucity of data about the safety of vein patch closure in the setting of femoral endarterectomy. Methods/results: From May 2012 to May 2015, 115 femoral endarterectomies with patch closure were performed. A patch rupture occurred in three cases (2.6% with a mortality rate of 66% (2/3. In all cases the greater saphenous vein below the knee was used as patch material. Discussion/conclusion: Vein patches, particularly from small calibre veins, should be excluded in femoral endarterectomy procedures as they pose a substantial risk of rupture. Keywords: Angioplasty, Patch rupture, Femoral artery, Patch, Great saphenous vein

Petrological Geodynamics of Mantle Melting I. AlphaMELTS + Multiphase Flow: Dynamic Equilibrium Melting, Method and Results

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Massimiliano Tirone

2017-10-01

Full Text Available The complex process of melting in the Earth's interior is studied by combining a multiphase numerical flow model with the program AlphaMELTS which provides a petrological description based on thermodynamic principles. The objective is to address the fundamental question of the effect of the mantle and melt dynamics on the composition and abundance of the melt and the residual solid. The conceptual idea is based on a 1-D description of the melting process that develops along an ideal vertical column where local chemical equilibrium is assumed to apply at some level in space and time. By coupling together the transport model and the chemical thermodynamic model, the evolution of the melting process can be described in terms of melt distribution, temperature, pressure and solid and melt velocities but also variation of melt and residual solid composition and mineralogical abundance at any depth over time. In this first installment of a series of three contributions, a two-phase flow model (melt and solid assemblage is developed under the assumption of complete local equilibrium between melt and a peridotitic mantle (dynamic equilibrium melting, DEM. The solid mantle is also assumed to be completely dry. The present study addresses some but not all the potential factors affecting the melting process. The influence of permeability and viscosity of the solid matrix are considered in some detail. The essential features of the dynamic model and how it is interfaced with AlphaMELTS are clearly outlined. A detailed and explicit description of the numerical procedure should make this type of numerical models less obscure. The general observation that can be made from the outcome of several simulations carried out for this work is that the melt composition varies with depth, however the melt abundance not necessarily always increases moving upwards. When a quasi-steady state condition is achieved, that is when melt abundance does not varies significantly

Varicose Veins: Role of Mechanotransduction of Venous Hypertension

Science.gov (United States)

Atta, Hussein M.

2012-01-01

Varicose veins affect approximately one-third of the adult population and result in significant psychological, physical, and financial burden. Nevertheless, the molecular pathogenesis of varicose vein formation remains unidentified. Venous hypertension exerted on veins of the lower extremity is considered the principal factor in varicose vein formation. The role of mechanotransduction of the high venous pressure in the pathogenesis of varicose vein formation has not been adequately investigated despite a good progress in understanding the mechanomolecular mechanisms involved in transduction of high blood pressure in the arterial wall. Understanding the nature of the mechanical forces, the mechanosensors and mechanotransducers in the vein wall, and the downstream signaling pathways will provide new molecular targets for the prevention and treatment of varicose veins. This paper summarized the current understanding of mechano-molecular pathways involved in transduction of hemodynamic forces induced by blood pressure and tries to relate this information to setting of venous hypertension in varicose veins. PMID:22489273

[Deep vein thrombosis prophylaxis.

Science.gov (United States)

Sandoval-Chagoya, Gloria Alejandra; Laniado-Laborín, Rafael

2013-01-01

Background: despite the proven effectiveness of preventive therapy for deep vein thrombosis, a significant proportion of patients at risk for thromboembolism do not receive prophylaxis during hospitalization. Our objective was to determine the adherence to thrombosis prophylaxis guidelines in a general hospital as a quality control strategy. Methods: a random audit of clinical charts was conducted at the Tijuana General Hospital, Baja California, Mexico, to determine the degree of adherence to deep vein thrombosis prophylaxis guidelines. The instrument used was the Caprini's checklist for thrombosis risk assessment in adult patients. Results: the sample included 300 patient charts; 182 (60.7 %) were surgical patients and 118 were medical patients. Forty six patients (15.3 %) received deep vein thrombosis pharmacologic prophylaxis; 27.1 % of medical patients received deep vein thrombosis prophylaxis versus 8.3 % of surgical patients (p < 0.0001). Conclusions: our results show that adherence to DVT prophylaxis at our hospital is extremely low. Only 15.3 % of our patients at risk received treatment, and even patients with very high risk received treatment in less than 25 % of the cases. We have implemented strategies to increase compliance with clinical guidelines.

Anomalous adrenal vein anatomy complicating the evaluation of primary hyperaldosteronism

Directory of Open Access Journals (Sweden)

Kaitlin M. Ford, BS

2018-02-01

Full Text Available Adrenal vein development in utero occurs concurrently with the development of the inferior vena cava, the renal veins, and the gonadal veins. The embryologic formation of these veins involves communication of various venous systems. Although the left adrenal-renal vein complex is most commonly described as a shared emptying of the left adrenal vein and the left inferior phrenic vein into the left renal vein, there have been reports of numerous anatomic variations of this complex. In this report, we present a case of a rare variant of the left adrenal vein, in which the left adrenal vein empties into the left gonadal vein, which takes an atypical course superolateral to the left kidney.

On dynamics of uranium vein mineralization

International Nuclear Information System (INIS)

Petrosyan, R.V.

1981-01-01

The formation of urnaium vein deposits and the essence of consanguinity of the mineralization and wall metasomatites are considered. The formation of uranium mineralization is analysed from the positions of Korzhinsky D. S. : the formation of metasomatite aureole and associated vein ores take place as a result of the development of one solution flow while the formation of mineral vein associations occurs on the background of contineous filtration of the solution during metasomato is due to a repeated (pulse) half-opening of fractures and their filling with a part of filtrating solution. The analysis of the available information on the example of two different uranium manifestations permits to reveal certain relations both in the character of wall rock alterations and between the metasomatosis and the formation of ore minerals in veins. The conclusion is made that spatial-time correlations of vein formations with wall metasomatites attest that the pulse formation of ores in veinlets occurs on the background and in interrelation with a consecutive precipitation of components in the aureole volume. The analysis of element migration dynamics in wall aureole carried out from the positions of the Korzhinsky hypothesis of the advance wave of acid components that takes into account the interaction of continuous and pulse mechanisms of solution movement permits to avoid contradictions when interpreting the processes of wall rock alterations and vein ore-forming, and permits to make a common scheme of vein ore-genesis [ru

A Morphological Insight of the Femoral Vein

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Ferreira AH

2015-10-01

Full Text Available A total of 13 cadavers (12 men and 1 women of different age group were used for the study with the purpose to determine the prevalence of femoral vein duplication. Lower limb regions (26 sides were carefully dissected as per the standard dissection procedure. Femoral vein (unitruncular was found in 96.15% of specimen. Bitruncular configurations (total bifidity was found in a male cadaver of 75 years of age (3.85%. In the right lower limb, 6.5 cms below the inguinal ligament the femoral vein - lateral ramus received the lateral circumflex femoral vein, and the medial circumflex femoral vein, and the lateral and medial ramii formed a common venous trunk. Knowledge of the truncular venous variations is important to recognize and avoid potential errors in diagnosis of deep venous thrombosis of the femoral vein, in the case of an occluded duplicated trunk.

Melting curves of molecular hydrogen and molecular deuterium under high pressures between 20 and 373 K

International Nuclear Information System (INIS)

Diatschenko, V.; Chu, C.W.; Liebenberg, D.H.; Young, D.A.; Ross, M.; Mills, R.L.

1985-01-01

We determined the melting curve of molecular hydrogen and molecular deuterium at closely spaced intervals from 20 to 373 K by two different techniques using high-pressure diamond cells. The cells were loaded with liquid at low temperature or with compressed gas at room temperature. Empirical functions for the melting curves were evaluated from least-squares fits of the data. Values of the compressibility and Debye temperature were computed at melting, and the results are compared with those calculated from various theoretical models. The good agreement shows that the models are generally valid, although small systematic deviations may point the way toward refinements in modeling. Our study also demonstrates the need to determine a one-piece intermolecular potential valid over a wide pressure range by refitting all experimental data, including the shock data recently made available

The Chicxulub crater - impact metamorphism of sulfate and carbonate lithologies

Science.gov (United States)

Deutsch, A.; Langenhorst, F.; Hornemann, U.; Ivanov, B. A.

2003-04-01

It is discussed whether in the aftermath of the Chicxulub event, impact-released CO_2 and SO_x have changed the Earth's climate, acting also as lethal thread for life. Undoubtedly, vaporization of carbonates and sulfates, which are major target lithologies at the Chicxulub impact site, occurred in the footprint of the projectile. What happened to these lithologies outside this very restricted zone was so far unconstrained. Petrologic observations on PEMEX and UNAM as well as on the CSDP cores allow to set up a general classification for shock-related pro-grade effects on sulfate and carbonate sedimentary rocks. Shock effects in lithic breccias are restricted to brecciation and formation of twins in calcite. Suevites mostly lack melted carbonate clasts; annealing effects in anhydrite fragments are absent. The underlying melt breccias contain anhydrite fragments still displaying a sedimentary texture, and limestone clasts, whose texture reflect crystallization from melt. Impact melt breccias from deeper levels frequently contain partially resorbed anhydrite clasts and a melt matrix with the Ca-rich mineral assemblage quartz + plagioclase + clinopyroxene; this mineral assemblage provides evidence for partial dissociation of CaSO_4. Large clasts of anhydrite consist of equant crystals with 120^o triple junctions, a feature indicative for re-crystallization in the solid state. Tagamites (impact melt rocks) are virtually free of clasts from sedimentary lithologies. These rocks have an extremely high formation temperature, which caused total dissociation of CaSO_4 and CaCO_3. Finally, up to 100 μm wide veins of anhydrite + calcite + quartz cut the matrix of all lithologies except the tagamites. They probably represent "degassing vents". The given scheme is in qualitative accordance with data of shock recovery and annealing experiments as well as with modeling results. In addition, it substantiates that annealing plays a fundamental role in the impact metamorphism of

Cavernous transformation of the portal vein

International Nuclear Information System (INIS)

Lehotska, V.; Dostalova, K.; Durkovsky, A.; Samal, V.

1995-01-01

In this contribution, the authors give an account of a rare case of a cavernous transformation of the portal vein that may have originated secondarily in a proliferative hematogenous disease with a polyglobulia and thrombosis in the periferal blood count as well as development of portal hypertension of a prehepatal type. The state of hyper-coagulation in a myeloproliferative disease may have lead to a chronic thrombosis of the portal vein with a subsequent malformation of the portal vein in terms of a cavernous transformation of the portal vein. The case is an interesting one because of the discrepancy between the gravity of the thrombotic complication and slightness of the symptoms in the clinical picture. The authors point out the importance of ultrasonography and computed tomography examination following the intravenous application of a water solution of a contrast medium in a morphologic diagnosing of a rare complication of a chronic thrombotic clot of the portal vein - the cavernous transformation. (authors)

Varicose Vein Treatment (Endovenous Ablation of Varicose Veins)

Science.gov (United States)

... associated veins. top of page What are the benefits vs. risks? Benefits No surgical incision is needed—only a small ... risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in ...

Preduodenal portal vein: its surgical significance.

Science.gov (United States)

Makey, D A; Bowen, J C

1978-11-01

Preduodenal portal vein is a rare anatomical variant which may be one of many anomalies in the neonate with duodenal "atresia." Preduodenal portal vein also may be an occasional finding in an adult undergoing biliary, gastric, or pancreatic surgery. Awareness and recognition of the anomaly are essential for the avoidance of injury during such operations. We report here a symptomless patient whose preduodenal portal vein was discovered at cholecystectomy.

Multimodal ultrasonographic assessment of leiomyosarcoma of the femoral vein in a patient misdiagnosed as having deep vein thrombosis: A case report.

Science.gov (United States)

Zhang, Mei; Yan, Feng; Huang, Bin; Wu, Zhoupeng; Wen, Xiaorong

2017-11-01

Primary leiomyosarcoma (LMS) of the vein is a rare tumor that arises from the smooth muscle cells of the vessel wall and has an extremely poor prognosis. This tumor can occur in vessels such as the inferior vena cava, great saphenous vein, femoral vein, iliac vein, popliteal vein, and renal vein; the inferior vena cava is the most common site. LMS of the femoral vein can result in edema and pain in the lower extremity; therefore, it is not easy to be differentiated from deep vein thrombosis (DVT). Moreover, virtually no studies have described the ultrasonographic features of LMS of the vein in detail. We present a case of a 55-year-old woman with LMS of the left femoral vein that was misdiagnosed as having deep vein thrombosis (DVT) on initial ultrasonographic examination. The patient began to experience edema and pain in her left leg seven months previously. She was diagnosed as having DVT on initial ultrasonographic examination, but the DVT treatment that she had received for 7 months failed to improve the status of her left lower limb. She subsequently underwent re-examination by means of a multimodal ultrasonographic imaging approach (regular B-mode imaging, color Doppler imaging, pulsed-wave Doppler imaging, contrast-enhanced ultrasonography), which confirmed a diagnosis of LMS. This patient was treated successfully with surgery. This case demonstrates that use of multiple ultrasonographic imaging techniques can be helpful to diagnose LMS accurately. Detection of vasculature in a dilated vein filled with a heterogeneous hypoechoic substance on ultrasonography is a sign of a tumor. The pitfall of misdiagnosing this tumor as DVT is a useful reminder.

Duplication of the Portal Vein: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Won; Shin, Hyeong Cheol; Jou, Sung Shick; Han, Jong Kyu; Kim, Il Young [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of)

2009-12-15

The duplication of the portal vein is an uncommon congenital anomaly. To date, only four cases have been reported in the medical literature. This anomaly can cause portal hypertension in pediatric patients. In addition, duplication of the portal vein has various patterns of connection with a splenic vein or mesenteric veins, and it can lie anterior or posterior to the duodenum. We report the MDCT findings of an adult patient with duplication of the portal vein that was found incidentally

Management of Post-Traumatic Phlegmasia Cerulea Dolens via Right-to-Left Femoral Vein to Femoral Vein Bypass (Palma Procedure).

Science.gov (United States)

Dua, Anahita; Heller, Jennifer; Lee, Cheong

2017-11-01

Phlegmasia cerulea dolens (PCD) is a rare condition resulting from venous occlusion that impairs arterial flow. We report a rare case of post-traumatic PCD after ligation of the iliac vein with successful treatment by right-to-left femoral vein to femoral vein bypass using left great saphenous vein (Palma procedure). The clinical presentation, diagnostic process, and approach to management along with a literature review on the operative management of PCD are presented in this case report.

Absent right superior caval vein in situs solitus

DEFF Research Database (Denmark)

Lytzen, Rebekka; Sundberg, Karin; Vejlstrup, Niels

2015-01-01

Introduction In up to 0.07% of the general population, the right anterior cardinal vein obliterates and the left remains open, creating an absent right superior caval vein and a persistent left superior caval vein. Absent right superior caval vein is associated with additional congenital heart...... disease in about half the patients. We wished to study the consequences of absent right superior caval vein as an incidental finding on prenatal ultrasonic malformation screening. Material and methods This is a retrospective case series study of all foetuses diagnosed with absent right superior caval vein...... no postnatal complications. All children were found to have healthy hearts at follow-up. CONCLUSIONS: In all cases, the findings proved to be a benign condition with no clinical manifestations or complications. Although isolated absent right superior caval vein does not seem to affect the outcome, associated...

Theoretical study of the aluminum melting curve to very high pressure

International Nuclear Information System (INIS)

Moriarty, J.A.; Young, D.A.; Ross, M.

1984-01-01

A detailed theoretical study of the Al melting curve from normal melting conditions to pressures in the vicinity of 2 Mbar is presented. The analysis is based on two parallel, but distinct, treatments of the metal: the first from rigorous generalized pseudopotential theory involving first-principles nonlocal pseudopotentials and the second from a parametrized local pseudopotential model which has been accurately fit to first-principles band-theory and experimental equation-of-state data. Both treatments utilize full lattice-dynamical calculations of the phonon free energy in the solid, within the harmonic approximation, and fluid variational theory to obtain the free energy of the liquid. Particular attention is focused on the choice of the reference system in implementing the fluid variational theory. It is shown that in Al the soft-sphere model of Ross produces a lower (and hence more accurate) liquid free energy than either the hard-sphere or one-component-plasma reference systems, and is, moreover, necessary to obtain a reasonable quantitative description of the melting properties. With the soft-sphere system, the two theoretical treatments give results in good overall agreement with each other and with experiment. In particular, melting on the shock Hugoniot is predicted to begin at about 1.2 Mbar and to end at about 1.55 Mbar, in excellent agreement with the recent preliminary measurements of McQueen

Finger vein extraction using gradient normalization and principal curvature

Science.gov (United States)

Choi, Joon Hwan; Song, Wonseok; Kim, Taejeong; Lee, Seung-Rae; Kim, Hee Chan

2009-02-01

Finger vein authentication is a personal identification technology using finger vein images acquired by infrared imaging. It is one of the newest technologies in biometrics. Its main advantage over other biometrics is the low risk of forgery or theft, due to the fact that finger veins are not normally visible to others. Extracting finger vein patterns from infrared images is the most difficult part in finger vein authentication. Uneven illumination, varying tissues and bones, and changes in the physical conditions and the blood flow make the thickness and brightness of the same vein different in each acquisition. Accordingly, extracting finger veins at their accurate positions regardless of their thickness and brightness is necessary for accurate personal identification. For this purpose, we propose a new finger vein extraction method which is composed of gradient normalization, principal curvature calculation, and binarization. As local brightness variation has little effect on the curvature and as gradient normalization makes the curvature fairly uniform at vein pixels, our method effectively extracts finger vein patterns regardless of the vein thickness or brightness. In our experiment, the proposed method showed notable improvement as compared with the existing methods.

Adventitial cystic disease of the common femoral vein presenting as deep vein thrombosis

Directory of Open Access Journals (Sweden)

Young-Kyun Kim

2016-07-01

Full Text Available Adventitial cystic disease of the common femoral vein is a rare condition. We herein report the case of a 50-year-old woman who presented with painless swelling in her left lower leg that resembled deep vein thrombosis. She underwent femoral exploration and excision of the cystic wall. The presentation, investigation, treatment, and pathology of this condition are discussed with a literature review.

Reduced energy consumption for melting in foundries

Energy Technology Data Exchange (ETDEWEB)

Skov-Hansen, S.

2007-09-15

By improving the gating technology in traditional gating systems it is possible to reduce the amount of metal to be re-melted, and hence reduce the energy consumption for melting in foundries. Traditional gating systems are known for a straight tapered down runner a well base and 90 deg. bends in the runner system. In the streamlined gating systems there are no sharp changes in direction and a large effort is done to confine and control the flow of the molten metal during mould filling. Experiments in real production lines have proven that using streamlined gating systems improves yield by decreasing the poured weight compared to traditional layouts. In a layout for casting of valve housings in a vertically parted mould the weight of the gating system was reduced by 1,1kg which is a 20% weight reduction for the gating system. In a layout for horizontally parted moulds the weight of the gating system has been reduced by 3,7kg which is a weight reduction of 60% for the gating system. The experiments casting valve housings in ductile iron also proved that it is possible to lower the pouring temperature from 1400 deg. C to 1300 deg. C without the risk of cold runs. Glass plate fronted moulds have been used to study the flow of melt during mould filling. These experiments have also been used for studying the flow pattern when ceramic filters are used. The thorough study of the use of filters revealed that the metal passing through the filter is divided into a number of small jets. This proves that filters do not have the claimed positive effect on the flow of metal. The volumes necessary on either side of the filter is not filled till a backpressure is build up and results in formation of pressure shocks when backfilled. These pressure shocks result in more turbulence inside the casting than the same gating system with no filter. Not using filters can mean a reduction in poured weight of 0,6kg. To examine if the experiments using glass plate fronted moulds give

Augmented reality based real-time subcutaneous vein imaging system.

Science.gov (United States)

Ai, Danni; Yang, Jian; Fan, Jingfan; Zhao, Yitian; Song, Xianzheng; Shen, Jianbing; Shao, Ling; Wang, Yongtian

2016-07-01

A novel 3D reconstruction and fast imaging system for subcutaneous veins by augmented reality is presented. The study was performed to reduce the failure rate and time required in intravenous injection by providing augmented vein structures that back-project superimposed veins on the skin surface of the hand. Images of the subcutaneous vein are captured by two industrial cameras with extra reflective near-infrared lights. The veins are then segmented by a multiple-feature clustering method. Vein structures captured by the two cameras are matched and reconstructed based on the epipolar constraint and homographic property. The skin surface is reconstructed by active structured light with spatial encoding values and fusion displayed with the reconstructed vein. The vein and skin surface are both reconstructed in the 3D space. Results show that the structures can be precisely back-projected to the back of the hand for further augmented display and visualization. The overall system performance is evaluated in terms of vein segmentation, accuracy of vein matching, feature points distance error, duration times, accuracy of skin reconstruction, and augmented display. All experiments are validated with sets of real vein data. The imaging and augmented system produces good imaging and augmented reality results with high speed.

Emerging melt quality control solution technologies for aluminium melt

Directory of Open Access Journals (Sweden)

Arturo Pascual, Jr

2009-11-01

Full Text Available The newly developed “MTS 1500” Melt Treatment System is performing the specifi cally required melt treatment operations like degassing, cleaning, modification and/or grain refinement by an automated process in one step and at the same location. This linked process is saving time, energy and metal losses allowing - by automated dosage of the melt treatment agents - the production of a consistent melt quality batch after batch. By linking the MTS Metal Treatment System with sensors operating on-line in the melt, i.e., with a hydrogen sensor “Alspek H”, a fully automated control of parts of the process chain like degassing is possible. This technology does guarantee a pre-specifi ed and documented melt quality in each melt treatment batch. Furthermore, to ensure that castings are consistent and predictable there is a growing realization that critical parameters such as metal cleanliness must be measured prior to casting. There exists accepted methods for measuring the cleanliness of an aluminum melt but these can be both slow and costly. A simple, rapid and meaningful method of measuring and bench marking the cleanliness of an aluminum melt has been developed to offer the foundry a practical method of measuring melt cleanliness. This paper shows the structure and performance of the integrated MTS melt treatment process and documents achieved melt quality standards after degassing, cleaning, modifi cation and grain refi nement operations under real foundry conditions. It also provides an insight on a melt cleanliness measuring device “Alspek MQ” to provide foundry men better tools in meeting the increasing quality and tighter specifi cation demand from the industry.

Personal authentication through dorsal hand vein patterns

Science.gov (United States)

Hsu, Chih-Bin; Hao, Shu-Sheng; Lee, Jen-Chun

2011-08-01

Biometric identification is an emerging technology that can solve security problems in our networked society. A reliable and robust personal verification approach using dorsal hand vein patterns is proposed in this paper. The characteristic of the approach needs less computational and memory requirements and has a higher recognition accuracy. In our work, the near-infrared charge-coupled device (CCD) camera is adopted as an input device for capturing dorsal hand vein images, it has the advantages of the low-cost and noncontact imaging. In the proposed approach, two finger-peaks are automatically selected as the datum points to define the region of interest (ROI) in the dorsal hand vein images. The modified two-directional two-dimensional principal component analysis, which performs an alternate two-dimensional PCA (2DPCA) in the column direction of images in the 2DPCA subspace, is proposed to exploit the correlation of vein features inside the ROI between images. The major advantage of the proposed method is that it requires fewer coefficients for efficient dorsal hand vein image representation and recognition. The experimental results on our large dorsal hand vein database show that the presented schema achieves promising performance (false reject rate: 0.97% and false acceptance rate: 0.05%) and is feasible for dorsal hand vein recognition.

Thrombosis of right ovarian vein

International Nuclear Information System (INIS)

Forner, J.; Talens, A.; Flores, M.; Mendez, M.

2001-01-01

Ovarian vein thrombosis is a rare postpartum complication (0.1%). It can be fatal, since it can lead to sepsis, pulmonary thromboembolisms and inferior vena cava or renal vein thrombosis. Computed tomography and magnetic resonance imaging are the techniques of choice for its diagnosis, while the value of ultrasound is limited due to its low sensitivity and specificity. We report the case of a woman who, during puerperium, developed thrombosis of right ovarian vein that presented clinical, ultrasonographic and computed tomographic features of appendicitis. We describe the radiological sings and stress the fact that this diagnosis should be suspected in puerperal women. (Author) 9 refs

Assessment and management of patients with varicose veins.

Science.gov (United States)

Allen, Louise

Varicose veins are enlarged superficial veins found in the legs. This article explores the anatomy and physiology of the venous system to assist nurses to assess, manage and treat patients with varicose veins.

Mineralogy, structural control and age of the Incachule Sb epithermal veins, the Cerro Aguas Calientes collapse caldera, Central Puna

Science.gov (United States)

Salado Paz, Natalia; Petrinovic, Iván; Do Campo, Margarita; Brod, José Affonso; Nieto, Fernando; da Silva Souza, Valmir; Wemmer, Klauss; Payrola, Patricio; Ventura, Roberto

2018-03-01

The Incachule Sb epithermal veins is located near to the N-E rim of the Cerro Aguas Calientes collapse caldera (17.5-10.8 Ma), in the geologic province of Puna, Salta- Argentina. It is hosted in Miocene felsic volcanic rocks with continental arc signature. The district includes twelve vein systems with mineralization of Sb occurring in hydrothermal breccias and stockwork. The veins are composed of quartz-sulfide with pyrite, stibnite and arsenopyrite. All around the veins, wall rocks are variably altered to clay minerals and sulfates in an area of around 2.5 km wide by more than 7 km long. The hydrothermal alterations recognized are: silicic, phyllic and argillic. The veins are characterized by high contents of Sb, As, and Tl and intermediate contents of Pb-Zn-Cu, and traces of Ag and Au. Homogenization and ice-melting temperatures of fluid inclusions vary from 125 °C to 189 °C and -2.4 °C to -0.8 °C. The isotopic data indicated a range of δ34S -3.04‰ to +0.72‰ consistent with a magmatic source for sulfur. We present the firsts K-Ar ages for hydrothermal illite/smectite mixed layers (I/SR1, 60% illite layers) and illite that constrain the age of the ore deposit (8.5-6.7 ± 0.2 Ma). The data shown here, let characterized the Incachule district as a shallow low sulfidation epithermal system hosted in a collapse caldera. Our data also indicate that mineralization is structurally controlled by a fault system related to the 10.3 Ma collapse of Aguas Calientes caldera. The interpreted local stress field is consistent with the regional one.

Deep vein thrombosis: a clinical review

Directory of Open Access Journals (Sweden)

Kesieme EB

2011-04-01

Full Text Available Emeka Kesieme1, Chinenye Kesieme2, Nze Jebbin3, Eshiobo Irekpita1, Andrew Dongo11Department of Surgery, Irrua Specialist Teaching Hospital, Irrua, Nigeria; 2Department of Paediatrics, Irrua Specialist Teaching Hospital, Irrua, Nigeria; 3Department of Surgery, University of Port Harcourt Teaching Hospital, Port-Harcourt, NigeriaBackground: Deep vein thrombosis (DVT is the formation of blood clots (thrombi in the deep veins. It commonly affects the deep leg veins (such as the calf veins, femoral vein, or popliteal vein or the deep veins of the pelvis. It is a potentially dangerous condition that can lead to preventable morbidity and mortality.Aim: To present an update on the causes and management of DVT.Methods: A review of publications obtained from Medline search, medical libraries, and Google.Results: DVT affects 0.1% of persons per year. It is predominantly a disease of the elderly and has a slight male preponderance. The approach to making a diagnosis currently involves an algorithm combining pretest probability, D-dimer testing, and compression ultrasonography. This will guide further investigations if necessary. Prophylaxis is both mechanical and pharmacological. The goals of treatment are to prevent extension of thrombi, pulmonary embolism, recurrence of thrombi, and the development of complications such as pulmonary hypertension and post-thrombotic syndrome.Conclusion: DVT is a potentially dangerous condition with a myriad of risk factors. Prophylaxis is very important and can be mechanical and pharmacological. The mainstay of treatment is anticoagulant therapy. Low-molecular-weight heparin, unfractionated heparin, and vitamin K antagonists have been the treatment of choice. Currently anticoagulants specifically targeting components of the common pathway have been recommended for prophylaxis. These include fondaparinux, a selective indirect factor Xa inhibitor and the new oral selective direct thrombin inhibitors (dabigatran and selective

Dual Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varix Draining into the Left Adrenal Vein and Left Inferior Phrenic Vein

International Nuclear Information System (INIS)

Nishida, Norifumi; Ninoi, Teruhisa; Kitayama, Toshiaki; Yamamoto, Akira; Sakai, Yukimasa; Sato, Kimihiko; Hamuro, Masao; Nakamura, Kenji; Inoue, Yuichi; Yamada, Ryusaku

2004-01-01

A 66-year-old woman with a gastric varix, draining into a dilated left adrenal vein and a left inferior phrenic vein, was treated with dual balloon-occluded retrograde transvenous obliteration (B-RTO). Under balloon occlusion of the left adrenal vein and the left inferior phrenic vein, retrograde injection of a sclerosant (5% ethanolamine oleate) into the gastric varix was performed. Two weeks later, disappearance of flow in the gastric varix was confirmed on endoscopic ultrasound examination

Significance of special blasting modes for anti shock struggle at hydrothermal Pribram uranium ore deposit

International Nuclear Information System (INIS)

Stenczel, J.

1988-01-01

Situations are presented which occur in connection with blasting jobs. Special blasting operations are described. In the Pribram uranium deposit two types of special blasting operations were tested. Conditions are described under which softening blasting was carried out. This type of work did not prove satisfactory in operation and is therefore not performed at the Pribram deposit. A theoretical analysis is made of shock distrubance blasting and the procedure of designing such projects, the placement of explosives and the determination of their size. Such blasting jobs have been tested in shock zones of vein node. The total weight of the explosive was 100 to 200 kg of Px V 19. In most cases a mine shock was initiated (in some cases with a delay of up to several dozen hours). The said method increases the technical safety of operation. At the Pribram deposit it is only used in cases of utmost necessity because its use increases costs and delays the procedure of mining work. (E.S.). 9 figs., 1 tab., 6 refs

Recurrence of superficial vein thrombosis in patients with varicose veins.

Science.gov (United States)

Karathanos, Christos; Spanos, Konstantinos; Saleptsis, Vassileios; Tsezou, Aspasia; Kyriakou, Despina; Giannoukas, Athanasios D

2016-08-01

To investigate which factors other than history of superficial vein thrombosis (SVT) are associated with recurrent spontaneous SVT episodes in patients with varicose veins (VVs). Patients with a history of spontaneous SVT and VVs were followed up for a mean period of 55 months. Demographics, comorbidities, and thrombophilia screening test were analyzed. Patients were grouped according to the clinical-etiology-anatomy-pathophysiology classification. A multiple logistic regression analysis with the forward likelihood ratio method was undertaken. Thirteen patients out of 97 had a recurrence SVT episode during the follow-up period. All those patients were identified to have a thrombophilia defect. Protein C and S, antithrombin, and plasminogen deficiencies were more frequently present in patients without recurrence. Gene mutations were present in 38% in the nonrecurrence group and 77% in the recurrence group. After logistic regression analysis, patients with dislipidemia and mutation in prothrombin G20210A (FII) had an increased risk for recurrence by 5.4-fold and 4.6-fold, respectively. No deep vein thrombosis or pulmonary embolism occurred. Dislipidemia and gene mutations of F II are associated with SVT recurrence in patients with VVs. A selection of patients may benefit from anticoagulation in the short term and from VVs intervention in the long term. © The Author(s) 2015.

Endovenous mechanochemical ablation of great saphenous vein incompetence using the ClariVein device: a safety study

NARCIS (Netherlands)

Eekeren, R. van; Boersma, D.; Elias, S.; Holewijn, S.; Werson, D.A.; Vries, J.P. de; Reijnen, M.M.P.J.

2011-01-01

PURPOSE: To evaluate the feasibility and safety of endovenous mechanochemical ablation (MOCA) for the treatment of great saphenous vein (GSV) incompetence. METHODS: The newly developed ClariVein device uses a technique that combines mechanical endothelial damage using a rotating wire with the

Gd-DTPA-enhanced MR venography for varicose veins of the calf

International Nuclear Information System (INIS)

Kohata, Yoshiko; Naito, Akira; Ito, Katuhide.

1995-01-01

2D time-of-flight MR venography (2D TOF MRV) was performed in 16 patients (25 calves) with varicose veins and 2 volunteers (4 calves), and compared with venography. Sequential SPGR (TR/TE/FA=45 ms/7 ms/60deg) transverse images and/or GRASS (TR/TE/FA=100 ms/13 ms/60deg) transverse images were obtained for MRV. Superior presaturation pulse (S-SAT) was placed in 21 calves, and 0.05 mmol/kg Gd-DTPA was used in all calves. Projection MRVs were generated with maximum intensity projection (MIP) reconstruction. Regarding sequence parameter, S-SAT was useful to eliminate signal from artery that would obscure the signal of deep veins. The detectability of deep veins was improved with the use of S-SAT. In the comparison with venography, MRV could more clearly demonstrate varicose veins more than 5 mm in diameter and their drainage veins than venography. But it could not so clearly demonstrate deep veins as venography. It could not detect fine varicose veins less than 5 mm in diameter and connecting veins with valve insufficiency. In the examination of varicose veins, detection of deep veins, large varicose veins and their main drainage veins is clinically important, because diagnosis of patency of deep veins and dilatation of the drainage veins is necessary to choose the treatment, concluding conservative therapy, stripping and sclerotherapy. However, detection of fine varicose veins and connecting veins are not so important because those veins seldom need treatment. MRV was not so suitable for detection of deep veins, but very useful for detection of varicose veins more than 5 mm in diameter and their main drainage veins. In conclusion, MRV is non-invasive and effective method in varicose veins of calf, and it can take the place of venography with the improvement of deep vein detectability. (author)

Leiomyosarcoma of the renal vein

Directory of Open Access Journals (Sweden)

Lemos Gustavo C.

2003-01-01

Full Text Available Leiomyosarcoma of the renal vein is a rare tumor of complex diagnosis. We presented a case of renal vein leiomyosarcoma detected in a routine study. The primary treatment was complete surgical removal of the mass. In cases where surgical removal is not possible the prognosis is poor, with high rates of local recurrence and distant spread.

The Compartment Syndrome Associated with Deep Vein Thrombosis due to Rattlesnake Bite: A Case Report

Directory of Open Access Journals (Sweden)

Radu Ciprian Tincu

2017-08-01

Full Text Available Background: Snakebite is a health issue specific to some parts of the world, especially in the tropical area, where it produces many victims. The main clinical damage caused by snake bite involves hemotoxic, neurotoxic and myotoxic reactions. It is also established that the importance of systemic impairment varies according to individual factors and are related to organ dysfunction, shock or hypotension. We report the case of a young woman suffering from snakebite who developed deep vein thrombosis and compartment syndrome. Case Report: We present the case of a 32-year-old Romanian woman who was injured by her own Crotalinae snake (also known as pit viper or rattlesnake on her left forearm. When admitted to our Emergency Department, she was conscious with a Glasgow coma scale of 12/15, somnolent, febrile, suffering of headache, tachypnea; the marks of the snakebite were located in the distal part of the anterior left forearm; she had pain and bleeding at the bite site and swelling of the left upper limb with lymphangitis up to the axilla. She experienced fasciotomy-requiring compartment syndrome of the upper limb and required unfractionated heparin and closed monitored using activated partial thromboplastin time evolution due micro-thrombosis in the brachial vein. Local improvement was achieved in the next 4 days with progressive diminish of local tenderness and swelling. Conclusion: Limb deep vein thrombosis might be induced by snakebite, despite pro-hemorrhagic general condition induced by the envenomation. High index of clinical suspicion is needed for early diagnosis and timely management which can improve survival of these patients

Volatile diffusion in silicate melts and its effects on melt inclusions

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P. Scarlato

2005-06-01

Full Text Available A compendium of diffusion measurements and their Arrhenius equations for water, carbon dioxide, sulfur, fluorine, and chlorine in silicate melts similar in composition to natural igneous rocks is presented. Water diffusion in silicic melts is well studied and understood, however little data exists for melts of intermediate to basic compositions. The data demonstrate that both the water concentration and the anhydrous melt composition affect the diffusion coefficient of water. Carbon dioxide diffusion appears only weakly dependent, at most, on the volatilefree melt composition and no effect of carbon dioxide concentration has been observed, although few experiments have been performed. Based upon one study, the addition of water to rhyolitic melts increases carbon dioxide diffusion by orders of magnitude to values similar to that of 6 wt% water. Sulfur diffusion in intermediate to silicic melts depends upon the anhydrous melt composition and the water concentration. In water-bearing silicic melts sulfur diffuses 2 to 3 orders of magnitude slower than water. Chlorine diffusion is affected by both water concentration and anhydrous melt composition; its values are typically between those of water and sulfur. Information on fluorine diffusion is rare, but the volatile-free melt composition exerts a strong control on its diffusion. At the present time the diffusion of water, carbon dioxide, sulfur and chlorine can be estimated in silicic melts at magmatic temperatures. The diffusion of water and carbon dioxide in basic to intermediate melts is only known at a limited set of temperatures and compositions. The diffusion data for rhyolitic melts at 800°C together with a standard model for the enrichment of incompatible elements in front of growing crystals demonstrate that rapid crystal growth, greater than 10-10 ms-1, can significantly increase the volatile concentrations at the crystal-melt interface and that any of that melt trapped

Genesis of the Assif El Mal Zn-Pb (Cu, Ag) vein deposit. An extension-related Mesozoic vein system in the High Atlas of Morocco. Structural, mineralogical, and geochemical evidence

Science.gov (United States)

Bouabdellah, M.; Beaudoin, G.; Leach, D.L.; Grandia, F.; Cardellach, E.

2009-01-01

The Assif El Mal Zn-Pb (Cu-Ag) vein system, located in the northern flank of the High Atlas of Marrakech (Morocco), is hosted in a Cambro-Ordovician volcaniclastic and metasedimentary sequence composed of graywacke, siltstone, pelite, and shale interlayered with minor tuff and mudstone. Intrusion of synorogenic to postorogenic Late Hercynian peraluminous granitoids has contact metamorphosed the host rocks giving rise to a metamorphic assemblage of quartz, plagioclase, biotite, muscovite, chlorite, amphibole, chloritoid, and garnet. The Assif El Mal Zn-Pb (Cu-Ag) mineralization forms subvertical veins with ribbon, fault breccia, cockade, comb, and crack and seal textures. Two-phase liquid-vapor fluid inclusions that were trapped during several stages occur in quartz and sphalerite. Primary inclusion fluids exhibit Th mean values ranging from 104??C to 198??C. Final ice-melting temperatures range from -8.1??C to -12.8??C, corresponding to salinities of ???15 wt.% NaCl equiv. Halogen data suggest that the salinity of the ore fluids was largely due to evaporation of seawater. Late secondary fluid inclusions have either Ca-rich, saline (26 wt.% NaCl equiv.), or very dilute (3.5 wt.% NaCl equiv.) compositions and homogenization temperatures ranging from 75??C to 150??C. The ??18O and ??D fluid values suggest an isotopically heterogeneous fluid source involving mixing between connate seawater and black-shale-derived organic waters. Low ??13CVPDB values ranging from -7.5??? to -7.7??? indicate a homogeneous carbon source, possibly organic matter disseminated in black shale hosting the Zn-Pb (Cu-Ag) veins. The calculated ??34SH2S values for reduced sulfur (22.5??? to 24.3???) are most likely from reduction of SO42- in trapped seawater sulfate or evaporite in the host rocks. Reduction of sulfate probably occurred through thermochemical sulfate reduction in which organic matter was oxidized to produce CO2 which ultimately led to precipitation of saddle dolomite with

Ultrasound assessment of great saphenous vein insufficiency

Directory of Open Access Journals (Sweden)

Chander RK

2015-06-01

Full Text Available Rajiv K Chander,1 Thomas S Monahan1,2 1Section of Vascular Surgery, Department of Surgery, University of Maryland School of Medicine, 2Department of Surgery, Baltimore Veterans Affairs Medical Center, Baltimore, MD, USA Abstract: Duplex ultrasonography is the ideal modality to assess great saphenous vein insufficiency. Duplex ultrasonography incorporates both gray scale images to delineate anatomy and color-Doppler imaging that visualizes the flow of blood in a structure. Assessment of great saphenous vein requires definition of the anatomy, augmentation of flow, evaluation for both superficial and deep vein thrombosis, and determining the presence of reflux. Currently, evolution in the treatment of reflux also relies on ultrasound for the treatment of the disease. Understanding the utilization of the ultrasound for the diagnosis and treatment of greater saphenous vein reflux is important for practitioners treating reflux disease. Keywords: duplex ultrasonography, small saphenous vein 

Double melting in polytetrafluoroethylene γ-irradiated above its melting point

International Nuclear Information System (INIS)

Serov, S.A.; Khatipov, S.A.; Sadovskaya, N.V.; Tereshenkov, A.V.; Chukov, N.A.

2012-01-01

Highlights: ► PTFE irradiation leads to formation of double melting peaks in DSC curves. ► This is connected to dual crystalline morphology typical for PTFE. ► Two crystalline types exist in the PTFE irradiated in the melt. - Abstract: PTFE irradiation above its melting point leads to formation of double melting and crystallization peaks in DSC curves. Splitting of melting peaks is connected to dual crystalline morphology typical for PTFE irradiated in the melt. According to electron microscopy, two crystalline types with different size and packing density exist in the irradiated PTFE.

Numerical simulation of nonequilibrium flow in high-enthalpy shock tunnel

Energy Technology Data Exchange (ETDEWEB)

Kaneko, M.; Men' shov, I.; Nakamura, Y

2005-03-01

The flow field of a nozzle starting process with thermal and chemical nonequilibrium has been simulated. This flow is produced in high enthalpy impulse facilities such as the free piston shock tunnel. The governing equations are the axisymmetric, compressible Navier-Stokes equations. In this study, Park's two-temperature model, where air consists of five species, is used for defining the thermodynamic properties of air as a driven gas. The numerical scheme employed here is the hybrid scheme of the explicit and implicit methods, which was developed in our laboratory, along with AUSM{sup +} to evaluate inviscid fluxes. In the present simulation, the Mach number of an incident shock wave is set at M{sub s}=10.0. It corresponds to a specific enthalpy, h{sub 0}, of 12 MJ/kg. The results clearly show the complicated thermal and chemical nonequilibrium flow field around the end of the shock tube section and at the nozzle inlet during the initial stage of the nozzle starting process. They also suggest that the phenomenon of nozzle melting might be associated with a flow separation at the nozzle inlet.

Gonadal vein tumor thrombosis due to renal cell carcinoma

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Hamidreza Haghighatkhah

2015-01-01

Full Text Available Renal cell carcinoma (RCC had a tendency to extend into the renal vein and inferior vena cava, while extension into the gonadal vein has been rarely reported. Gonadal vein tumor thrombosis appears as an enhancing filling defect within the dilated gonadal vein anterior to the psoas muscle and shows an enhancement pattern identical to that of the original tumor. The possibility of gonadal vein thrombosis should be kept in mind when looking at an imaging study of patients with RCC

Identifikasi Pepper vein yellows virus yang Berasosiasi dengan Penyakit Yellow Vein Banding pada Tanaman Mentimun di Bali

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I Dewa Nyoman Nyana

2016-11-01

Full Text Available Yellowing vein banding disease has been reported infecting cucurbit plants in Bali since 2014. Similar vein banding symptom on chilli pepper was observed previously, and early diagnosis indicated infection of Polerovirus. The objective of this research was to confirm the presence of Polerovirus infection on cucumber plant showing yellow vein banding symptom in Bali. Reverse transcription polymerase chain reaction – based detection method was conducted using specific primer pairs PeVYV-CP-F-BamH1/ PeVYV-CP-R-Pst1followed by sequencing and nucleotide sequence analysis.  Specific DNA fragments of ± 650 bp was successfully amplified from field samples.  Nucleotide sequence analysis showed that the sequence has the highest similarity > 95% with Pepper vein yellow virus (PeVYV infecting chili pepper from Indonesia (Bali, and Rembang, Japan, and Greece.

Endovascular management for significant iatrogenic portal vein bleeding.

Science.gov (United States)

Kim, Jong Woo; Shin, Ji Hoon; Park, Jonathan K; Yoon, Hyun-Ki; Ko, Gi-Young; Gwon, Dong Il; Kim, Jin Hyoung; Sung, Kyu-Bo

2017-11-01

Background Despite conservative treatment, hemorrhage from an intrahepatic branch of the portal vein can cause hemodynamic instability requiring urgent intervention. Purpose To retrospectively report the outcomes of hemodynamically significant portal vein bleeding after endovascular management. Material and Methods During a period of 15 years, four patients (2 men, 2 women; median age, 70.5 years) underwent angiography and embolization for iatrogenic portal vein bleeding. Causes of hemorrhage, angiographic findings, endovascular treatment, and complications were reported. Results Portal vein bleeding occurred after percutaneous liver biopsy (n = 2), percutaneous radiofrequency ablation (n = 1), and percutaneous cholecystostomy (n = 1). The median time interval between angiography and percutaneous procedure was 5 h (range, 4-240 h). Common hepatic angiograms including indirect mesenteric portograms showed active portal vein bleeding into the peritoneal cavity with (n = 1) or without (n = 2) an arterioportal (AP) fistula, and portal vein pseudoaneurysm alone with an AP fistula (n = 1). Successful transcatheter arterial embolization (n = 2) or percutaneous transhepatic portal vein embolization (n = 2) was performed. Embolic materials were n-butyl cyanoacrylate alone (n = 2) or in combination with gelatin sponge particles and coils (n = 2). There were no major treatment-related complications or patient mortality within 30 days. Conclusion Patients with symptomatic or life-threatening portal vein bleeding following liver-penetrating procedures can successfully be managed with embolization.

Conventional tomographic hilar anatomy emphasizing the pulmonary veins

International Nuclear Information System (INIS)

Genereux, G.P.

1983-01-01

The pulmonary hili are a frequent site of interpretive uncertainty because of thir complex anatomy. The right hilar shadow relates primarily to the ascending and descending pulmonary arteries and the right superior pulmonary vein, whereas the left hilar density accrues from the left pulmonary artery, left descending pulmonary artery, and left superior pulmonary vein. The right and left superoir pulmonary veins are intimately associated with and inseparable from the arteries. Knowledge of the course of these veins facilitates their identification on conventional tomograms. The right and left inferior pulmonary veins lie behind the lower hili and contribute only a small increment to the normal hilar density; the horizontal course of these vessels readily distinguishes them from the vertically oriented lower lobe arteries. Prominence of both the right and left superior and inferior veins may cause hilar pseudotumors. Conventional tomograms are most helpful in understanding plain radiographs. A multiview approach in anteroposterior, 55 0 posterior oblique, and lateral projections is recommended for a complete assessment. Computed tomography in transaxial sections adds further understanding of spatial relations in the hili, including the contributions of the pulmonary veins

Evaluation of the portal veins, hepatic veins and bile ducts using fat-suppressed segmented True FISP

International Nuclear Information System (INIS)

Ueda, Takashi; Uchikoshi, Masato; Imaoka, Izumi; Iwaya, Kazuo; Matsuo, Michimasa; Wada, Akihiko

2005-01-01

True FISP (fast imaging with steady-state free precession) is a fast imaging technique that provides high SNR (signal to noise ratio) and excellent delineation of parenchymal organs. The contrast of True FISP depends on the mixture of T 2 /T 1 . Vessels with slow flow are usually displayed as high signal intensity on True FISP images. The purpose of this study was to optimize fat-suppressed (FS) segmented True FISP imaging for portal veins, hepatic veins, and bile ducts. FS segmented True FISP images were applied to the phantoms of liver parenchyma, saline, and oil with various flip angles (every 10 degrees from 5-65 degrees) and k-space segmentations (3, 15, 25, 51, 75, 99). Five healthy volunteers were also examined to get optimized flip angle and k-space segmentation. The largest flip angle, 65 degrees, showed the best contrast between the liver parenchyma phantom, saline, and oil. The largest segmentations, 99, provided the best contrast between a liver parenchyma phantom and saline. However, the signal of the oil phantom exceeded that of the liver parenchyma phantom with 99 segmentations. As a result, the flip angle of 65 degrees and 75 segments is recommended to get the best contrast between the liver parenchyma phantom and saline, while suppressing the signal of oil. The volunteer studies also support the phantom studies and showed excellent anatomical delineation of portal veins, hepatic veins, and bile ducts when using these parameters. We conclude that True FISP is potentially suitable for the imaging of portal veins, hepatic veins, and bile ducts. The flip angle of 65 degrees with 75 segments is recommended to optimize FS segmented True FISP images. (author)

Petrology, chronology and sequence of vein systems: Systematic magmatic and hydrothermal history of a major intracontinental shear zone, Canadian Appalachians

Science.gov (United States)

Pe-Piper, Georgia; Piper, David J. W.; McFarlane, Chris R. M.; Sangster, Chris; Zhang, Yuanyuan; Boucher, Brandon

2018-04-01

Intra-continental shear zones developed during continental collision may experience prolonged magmatism and mineralization. The Cobequid Shear Zone formed part of a NE-SW-trending, orogen-parallel shear system in the late Devonian-early Carboniferous, where syn-tectonic granite-gabbro plutons and volcanic rocks 4 km thick were progressively deformed. In late Carboniferous to Permian, Alleghanian collision of Africa with Laurentia formed the E-W trending Minas Fault Zone, reactivating parts of the Cobequid Shear Zone. The 50 Ma history of hydrothermal mineralization following pluton emplacement is difficult to resolve from field relationships of veins, but SEM study of thin sections provides clear detail on the sequence of mineralization. The general paragenesis is: albite ± quartz ± chlorite ± monazite → biotite → calcite, allanite, pyrite → Fe-carbonates, Fe-oxides, minor sulfides, calcite and synchysite. Chronology was determined from literature reports and new U-Pb LA-ICPMS dating of monazite and allanite in veins. Vein mineralization was closely linked to magmatic events. Vein emplacement occurred preferentially during fault movement recognised from basin-margin inversion, as a result of fractures opening in the damage zone of master faults. The sequence of mineralization, from ca. 355 Ma riebeckite and albite veins to ca. 327 (-305?) Ma siderite-magnetite and sulfide mineralization, resembles Precambrian iron-oxide-copper-gold (IOCG) systems in the literature. The abundant magmatic Na, halogens and CO2 in veins and some magmatic bodies, characteristic of IOCG systems, were derived from the deeply subducted Rheic Ocean slab with little terrigenous sediment. Regional extension of the Magdalen Basin caused asthenospheric upwelling and melting of the previously metasomatized sub-continental lithospheric mantle. Crustal scale strike-slip faulting facilitated the rise of magmas, resulting in high heat flow driving an active hydrothermal system. Table S2

Generating and analyzing synthetic finger vein images

OpenAIRE

Hillerström, Fieke; Kumar, Ajay; Veldhuis, Raymond N.J.

2014-01-01

Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have posed challenges in exploring this technology for large scale applications. This paper details the first such attempt to synthesize finger-vein images and presents analysis of synthesized images fo...

Geometrical shock dynamics for magnetohydrodynamic fast shocks

KAUST Repository

Mostert, W.; Pullin, D. I.; Samtaney, Ravi; Wheatley, V.

2016-01-01

We describe a formulation of two-dimensional geometrical shock dynamics (GSD) suitable for ideal magnetohydrodynamic (MHD) fast shocks under magnetic fields of general strength and orientation. The resulting area–Mach-number–shock-angle relation is then incorporated into a numerical method using pseudospectral differentiation. The MHD-GSD model is verified by comparison with results from nonlinear finite-volume solution of the complete ideal MHD equations applied to a shock implosion flow in the presence of an oblique and spatially varying magnetic field ahead of the shock. Results from application of the MHD-GSD equations to the stability of fast MHD shocks in two dimensions are presented. It is shown that the time to formation of triple points for both perturbed MHD and gas-dynamic shocks increases as (Formula presented.), where (Formula presented.) is a measure of the initial Mach-number perturbation. Symmetry breaking in the MHD case is demonstrated. In cylindrical converging geometry, in the presence of an azimuthal field produced by a line current, the MHD shock behaves in the mean as in Pullin et al. (Phys. Fluids, vol. 26, 2014, 097103), but suffers a greater relative pressure fluctuation along the shock than the gas-dynamic shock. © 2016 Cambridge University Press

Geometrical shock dynamics for magnetohydrodynamic fast shocks

KAUST Repository

Mostert, W.

2016-12-12

We describe a formulation of two-dimensional geometrical shock dynamics (GSD) suitable for ideal magnetohydrodynamic (MHD) fast shocks under magnetic fields of general strength and orientation. The resulting area–Mach-number–shock-angle relation is then incorporated into a numerical method using pseudospectral differentiation. The MHD-GSD model is verified by comparison with results from nonlinear finite-volume solution of the complete ideal MHD equations applied to a shock implosion flow in the presence of an oblique and spatially varying magnetic field ahead of the shock. Results from application of the MHD-GSD equations to the stability of fast MHD shocks in two dimensions are presented. It is shown that the time to formation of triple points for both perturbed MHD and gas-dynamic shocks increases as (Formula presented.), where (Formula presented.) is a measure of the initial Mach-number perturbation. Symmetry breaking in the MHD case is demonstrated. In cylindrical converging geometry, in the presence of an azimuthal field produced by a line current, the MHD shock behaves in the mean as in Pullin et al. (Phys. Fluids, vol. 26, 2014, 097103), but suffers a greater relative pressure fluctuation along the shock than the gas-dynamic shock. © 2016 Cambridge University Press

Melting method for miscellaneous radioactive solid waste and melting furnace

International Nuclear Information System (INIS)

Osaki, Toru; Furukawa, Hirofumi; Uda, Nobuyoshi; Katsurai, Kiyomichi

1998-01-01

A vessel containing miscellaneous solid wastes is inserted in a crucible having a releasable material on the inner surface, they are induction-heated from the outside of the crucible by way of low temperature heating coils to melt low melting point materials in the miscellaneous wastes within a temperature range at which the vessel does not melt. Then, they are induction-heated by way of high temperature heating coils to melt the vessel and not yet melted materials, those molten materials are cooled, solidified molten material and the releasable material are taken out, and then the crucible is used again. Then, the crucible can be used again, so that it can be applied to a large scaled melting furnace which treats wastes by a unit of drum. In addition, since the cleaning of the used crucible and the application of the releasable material can be conducted without interrupting the operation of the melting furnace, the operation cycle of the melting furnace can be shortened. (N.H.)

High thermal shock resistance of the hot rolled and swaged bulk W–ZrC alloys

Energy Technology Data Exchange (ETDEWEB)

Xie, Z.M.; Liu, R.; Miao, S.; Yang, X.D. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Zhang, T., E-mail: zhangtao@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Fang, Q.F.; Wang, X.P. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Liu, C.S., E-mail: csliu@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Lian, Y.Y. [Southwestern Institute of Physics, Chengdu (China); Liu, X., E-mail: xliu@swip.ac.cn [Southwestern Institute of Physics, Chengdu (China); Luo, G.N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2016-02-15

The thermal shock (single shot) resistance and mechanical properties of the W–0.5wt% ZrC (WZC) alloys manufactured by ordinary sintering followed by swaging or rolling process were investigated. No cracks or surface melting were detected on the surface of the rolled WZC alloy plates after thermal shock at a power density of 0.66 GW/m{sup 2} for 5 ms, while primary intergranular cracks appear on the surface of the swaged WZC samples after thermal shock at a power density of 0.44 GW/m{sup 2} for 5 ms. Three point bending tests indicate that the rolled WZC alloy has a flexural strength of ∼2.4 GPa and a total strain of 1.8% at room temperature, which are 100% and 260% higher than those of the swaged WZC, respectively. The fracture energy density of the rolled WZC alloy is 3.23 × 10{sup 7} J/m{sup 3}, about 10 times higher than that of the swaged WZC (2.9 × 10{sup 6} J/m{sup 3}). The high thermal shock resistance of the rolled WZC alloys can be ascribed to their extraordinary ductility and plasticity. - Graphical abstract: (Left panel) surface morphology observed by optical microscope after a single pulse for 5 ms with various absorbed power densities at RT on the rolled WZC. (Right panel) curves of flexural stress versus strain at RT (a) and the calculated fracture energy (b) for the swaged WZC and rolled WZC alloys. - Highlights: • No cracks or surface melting were detected on the rolled WZC alloy samples after thermal shock at 0.66 GW/m{sup 2} for 5 ms. • Hot rolled WZC alloy plates exhibit a flexural strength of 2.4 GPa and a strain of 1.8% at RT. • The fracture energy of the rolled WZC alloy is 3.23 × 10{sup 7} J/m{sup 3} at RT, about 10 times higher than that of the swaged WZC. • A detailed analysis of the relationships between the mechanical properties and the thermal shock resistance is given.

Optoacoustic measurement of central venous oxygenation for assessment of circulatory shock: clinical study in cardiac surgery patients

Science.gov (United States)

Petrov, Irene Y.; Prough, Donald S.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. Nan; Seeton, Roger; Salter, Michael G.; Esenaliev, Rinat O.

2014-03-01

Circulatory shock is a dangerous medical condition, in which blood flow cannot provide the necessary amount of oxygen to organs and tissues. Currently, its diagnosis and therapy decisions are based on hemodynamic parameters (heart rate, blood pressure, blood gases) and mental status of a patient, which all have low specificity. Measurement of mixed or central venous blood oxygenation via catheters is more reliable, but highly invasive and associated with complications. Our previous studies in healthy volunteers demonstrated that optoacoustic systems provide non-invasive measurement of blood oxygenation in specific vessels, including central veins. Here we report our first results of a clinical study in coronary artery bypass graft (CABG) surgery patients. We used a medical-grade OPO-based optoacoustic system developed in our laboratory to measure in real time blood oxygenation in the internal jugular vein (IJV) of these patients. A clinical ultrasound imaging system (GE Vivid e) was used for IJV localization. Catheters were placed in the IJV as part of routine care and blood samples taken via the catheters were processed with a CO-oximeter. The optoacoustic oxygenation data were compared to the CO-oximeter readings. Good correlation between the noninvasive and invasive measurements was obtained. The results of these studies suggest that the optoacoustic system can provide accurate, noninvasive measurements of central venous oxygenation that can be used for patients with circulatory shock.

Endovascular Radiofrequency Ablation for Varicose Veins

Science.gov (United States)

2011-01-01

Executive Summary Objective The objective of the MAS evidence review was to conduct a systematic review of the available evidence on the safety, effectiveness, durability and cost–effectiveness of endovascular radiofrequency ablation (RFA) for the treatment of primary symptomatic varicose veins. Background The Ontario Health Technology Advisory Committee (OHTAC) met on August 26th, 2010 to review the safety, effectiveness, durability, and cost-effectiveness of RFA for the treatment of primary symptomatic varicose veins based on an evidence-based review by the Medical Advisory Secretariat (MAS). Clinical Condition Varicose veins (VV) are tortuous, twisted, or elongated veins. This can be due to existing (inherited) valve dysfunction or decreased vein elasticity (primary venous reflux) or valve damage from prior thrombotic events (secondary venous reflux). The end result is pooling of blood in the veins, increased venous pressure and subsequent vein enlargement. As a result of high venous pressure, branch vessels balloon out leading to varicosities (varicose veins). Symptoms typically affect the lower extremities and include (but are not limited to): aching, swelling, throbbing, night cramps, restless legs, leg fatigue, itching and burning. Left untreated, venous reflux tends to be progressive, often leading to chronic venous insufficiency (CVI). A number of complications are associated with untreated venous reflux: including superficial thrombophlebitis as well as variceal rupture and haemorrhage. CVI often results in chronic skin changes referred to as stasis dermatitis. Stasis dermatitis is comprised of a spectrum of cutaneous abnormalities including edema, hyperpigmentation, eczema, lipodermatosclerosis and stasis ulceration. Ulceration represents the disease end point for severe CVI. CVI is associated with a reduced quality of life particularly in relation to pain, physical function and mobility. In severe cases, VV with ulcers, QOL has been rated to be as bad

Umbilical vein draining into the inferior vena cava via the internal iliac vein, bypassing the liver

International Nuclear Information System (INIS)

Currarino, G.; Stannard, M.W.; Texas Univ., Dallas, TX; Kolni, H.

1991-01-01

This is the third report of an anomalous umbilical vein draining ectopically in a left pelvic vein, probably the left internal iliac, and through the inferior vena cava into the right atrium. The anomaly was encountered in a newborn infant with nonimmune hydrops fetalis, hypertrophic cardiomyopathy, multiorgan failure and possibly Noonan Syndrome. (orig.)

Umbilical vein draining into the inferior vena cava via the internal iliac vein, bypassing the liver

Energy Technology Data Exchange (ETDEWEB)

Currarino, G.; Stannard, M.W. (Children' s Medical Center, Dallas, TX (United States). Dept. of Radiology Texas Univ., Dallas, TX (United States). Southwestern Medical Center); Kolni, H. (Methodist Hospital, Dallas, TX (United States). Dept. of Pediatrics)

1991-05-01

This is the third report of an anomalous umbilical vein draining ectopically in a left pelvic vein, probably the left internal iliac, and through the inferior vena cava into the right atrium. The anomaly was encountered in a newborn infant with nonimmune hydrops fetalis, hypertrophic cardiomyopathy, multiorgan failure and possibly Noonan Syndrome. (orig.).

Noble gases, nitrogen, cosmic ray exposure history and mineralogy of Beni M'hira (L6) chondrite

Science.gov (United States)

Mahajan, Ramakant R.; Nejia, Laridhi Ouazaa; Ray, Dwijesh; Naik, Sekhar

2018-03-01

The concentrations and isotopic composition of noble gases helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon(Xe) and nitrogen were measured in the Beni M'hira L6 chondrite. The cosmic ray exposure age of Beni M'hira is estimated of 15.6 ± 3.7 (Ma). The radiogenic age, of around 485 ± 64 Ma, derived from 4He, and of around 504 ± 51 Ma from 40Ar, suggests an age resetting indicating the event impact. The heavy noble gases (Ar, Kr and Xe) concentrations imply that the gas is a mixture of trapped component Q and solar wind. The measured nitrogen abundance of 0.74 ppm and the isotopic signature of δ15N = 14.6‰ are within the range of ordinary chondrites. The homogeneous chemical composition of olivine (Fa:26 ± 0.25) and low-Ca pyroxene (Fs:22.4 ± 0.29) suggest that the Beni M'hira meteorite is an equilibrated chondrite. This is further corroborated by strong chondrule-matrix textural integration (lack of chondrules, except a few relict clast). Shock metamorphism generally corresponds to S5 (>45 GPa), however, locally disequilibrium melting (shock-melt veins) suggests, that the peak shock metamorphism was at ∼75 GPa, 950 °C.

Patterning of leaf vein networks by convergent auxin transport pathways.

Science.gov (United States)

Sawchuk, Megan G; Edgar, Alexander; Scarpella, Enrico

2013-01-01

The formation of leaf vein patterns has fascinated biologists for centuries. Transport of the plant signal auxin has long been implicated in vein patterning, but molecular details have remained unclear. Varied evidence suggests a central role for the plasma-membrane (PM)-localized PIN-FORMED1 (PIN1) intercellular auxin transporter of Arabidopsis thaliana in auxin-transport-dependent vein patterning. However, in contrast to the severe vein-pattern defects induced by auxin transport inhibitors, pin1 mutant leaves have only mild vein-pattern defects. These defects have been interpreted as evidence of redundancy between PIN1 and the other four PM-localized PIN proteins in vein patterning, redundancy that underlies many developmental processes. By contrast, we show here that vein patterning in the Arabidopsis leaf is controlled by two distinct and convergent auxin-transport pathways: intercellular auxin transport mediated by PM-localized PIN1 and intracellular auxin transport mediated by the evolutionarily older, endoplasmic-reticulum-localized PIN6, PIN8, and PIN5. PIN6 and PIN8 are expressed, as PIN1 and PIN5, at sites of vein formation. pin6 synthetically enhances pin1 vein-pattern defects, and pin8 quantitatively enhances pin1pin6 vein-pattern defects. Function of PIN6 is necessary, redundantly with that of PIN8, and sufficient to control auxin response levels, PIN1 expression, and vein network formation; and the vein pattern defects induced by ectopic PIN6 expression are mimicked by ectopic PIN8 expression. Finally, vein patterning functions of PIN6 and PIN8 are antagonized by PIN5 function. Our data define a new level of control of vein patterning, one with repercussions on other patterning processes in the plant, and suggest a mechanism to select cell files specialized for vascular function that predates evolution of PM-localized PIN proteins.

Patterning of leaf vein networks by convergent auxin transport pathways.

Directory of Open Access Journals (Sweden)

Megan G Sawchuk

Full Text Available The formation of leaf vein patterns has fascinated biologists for centuries. Transport of the plant signal auxin has long been implicated in vein patterning, but molecular details have remained unclear. Varied evidence suggests a central role for the plasma-membrane (PM-localized PIN-FORMED1 (PIN1 intercellular auxin transporter of Arabidopsis thaliana in auxin-transport-dependent vein patterning. However, in contrast to the severe vein-pattern defects induced by auxin transport inhibitors, pin1 mutant leaves have only mild vein-pattern defects. These defects have been interpreted as evidence of redundancy between PIN1 and the other four PM-localized PIN proteins in vein patterning, redundancy that underlies many developmental processes. By contrast, we show here that vein patterning in the Arabidopsis leaf is controlled by two distinct and convergent auxin-transport pathways: intercellular auxin transport mediated by PM-localized PIN1 and intracellular auxin transport mediated by the evolutionarily older, endoplasmic-reticulum-localized PIN6, PIN8, and PIN5. PIN6 and PIN8 are expressed, as PIN1 and PIN5, at sites of vein formation. pin6 synthetically enhances pin1 vein-pattern defects, and pin8 quantitatively enhances pin1pin6 vein-pattern defects. Function of PIN6 is necessary, redundantly with that of PIN8, and sufficient to control auxin response levels, PIN1 expression, and vein network formation; and the vein pattern defects induced by ectopic PIN6 expression are mimicked by ectopic PIN8 expression. Finally, vein patterning functions of PIN6 and PIN8 are antagonized by PIN5 function. Our data define a new level of control of vein patterning, one with repercussions on other patterning processes in the plant, and suggest a mechanism to select cell files specialized for vascular function that predates evolution of PM-localized PIN proteins.

Quantification of deep medullary veins at 7 T brain MRI

Energy Technology Data Exchange (ETDEWEB)

Kuijf, Hugo J.; Viergever, Max A.; Vincken, Koen L. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Bouvy, Willem H.; Razoux Schultz, Tom B.; Biessels, Geert Jan [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Zwanenburg, Jaco J.M. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands)

2016-10-15

Deep medullary veins support the venous drainage of the brain and may display abnormalities in the context of different cerebrovascular diseases. We present and evaluate a method to automatically detect and quantify deep medullary veins at 7 T. Five participants were scanned twice, to assess the robustness and reproducibility of manual and automated vein detection. Additionally, the method was evaluated on 24 participants to demonstrate its application. Deep medullary veins were assessed within an automatically created region-of-interest around the lateral ventricles, defined such that all veins must intersect it. A combination of vesselness, tubular tracking, and hysteresis thresholding located individual veins, which were quantified by counting and computing (3-D) density maps. Visual assessment was time-consuming (2 h/scan), with an intra-/inter-observer agreement on absolute vein count of ICC = 0.76 and 0.60, respectively. The automated vein detection showed excellent inter-scan reproducibility before (ICC = 0.79) and after (ICC = 0.88) visually censoring false positives. It had a positive predictive value of 71.6 %. Imaging at 7 T allows visualization and quantification of deep medullary veins. The presented method offers fast and reliable automated assessment of deep medullary veins. (orig.)

Preoperative mapping of the saphenous vein

DEFF Research Database (Denmark)

Levi-Mazloum, Niels Donald; Sillesen, H; Nielsen, Tina G

1996-01-01

A series of 124 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. 33 (27%) bypass procedures thrombosed within the first year. A naturally occurring optimal vein diameter was discovered: 5.0-6.5 mm at mid-thigh lev...

Recanalization after acute deep vein thrombosis

Directory of Open Access Journals (Sweden)

Gustavo Mucoucah Sampaio Brandao

2013-12-01

Full Text Available The process of recanalization of the veins of the lower limbs after an episode of acute deep venous thrombosis is part of the natural evolution of the remodeling of the venous thrombus in patients on anticoagulation with heparin and vitamin K inhibitors. This remodeling involves the complex process of adhesion of thrombus to the wall of the vein, the inflammatory response of the vessel wall leading to organization and subsequent contraction of the thrombus, neovascularization and spontaneous lysis of areas within the thrombus. The occurrence of spontaneous arterial flow in recanalized thrombosed veins has been described as secondary to neovascularization and is characterized by the development of flow patterns characteristic of arteriovenous fistulae that can be identified by color duplex scanning. In this review, we discuss some controversial aspects of the natural history of deep vein thrombosis to provide a better understanding of its course and its impact on venous disease.

Renal vein doppler sonography in rabbits with acute ureteral obstruction: usefulness of impedance index of renal vein

International Nuclear Information System (INIS)

Sohn, Kyung Myung; Chung, Su Kyo; Lee, Sung Yong

2004-01-01

To evaluate the usefulness of the impedance index of the renal vein for the diagnosis of acute obstructive uropathy in rabbits. Ligation of the left ureter was done in 12 rabbits. Doppler sonography of the interlobar veins in both kidneys was checked before and 30 minutes, 1, 3, 6, 9 and 24 hours after ureteral ligation. The venous impedance index [(peak flow signal-least flow signal)/peak flow signal] was compared between the obstructed and non-obstructed kidneys for all periods. The change in the impedance index after ureteral ligation was also compared between the obstructed and non-obstructed kidneys. A decrease in the impedance index of the intrarenal vein was observed starting from 30 mins atter ureteral ligation, and the index remained low up to 24 hours after ureteral ligation. The obstructed kidneys had a significantly lower impedance index than the contralateral kidneys for all six of the postligation measurements (p< 0.05). There were significant differences in the change of impedance index after ureteral ligation between the obstructed and non-obstructed kidneys (p< 0.05). The impedance index of the intrarenal vein was significantly decreased in the obstructed kidneys. The measurement of the impedance index of the intrarenal vein using Doppler sonography could provide a useful method of diagnosing obstructive uropathy

Percutaneous transhepatic portal vein stenting in a patient with benign non-transplant postoperative portal vein stenosis: A case report

OpenAIRE

Madhusudhan, KS; Agrawal, Nikhil; Srivastava, Deep N; Pal, Sujoy; Gupta, Arun K

2013-01-01

Extrahepatic portal vein stenosis is caused by a variety of benign and malignant diseases and results in development of symptoms due to portal hypertension. Benign post-surgical adhesions causing portal vein stenosis in non-transplant population is an uncommon etiology of portal hypertension. Endovascular treatment of such patients with angioplasty and stenting is uncommonly reported in literature. We report a case of portal hypertension caused by benign postoperative portal vein fibrosis, su...

Animal Model of Acute Deep Vein Thrombosis

International Nuclear Information System (INIS)

Roy, Sumit; Laerum, Frode; Brosstad, Frank; Kvernebo, Knut; Sakariassen, Kjell S.

1998-01-01

Purpose: To develop an animal model of acute deep vein thrombosis (DVT). Methods: In part I of the study nine juvenile domestic pigs were used. Each external iliac vein was transluminally occluded with a balloon catheter. Thrombin was infused through a microcatheter in one leg according to one of the following protocols: (1) intraarterial (IA): 1250 U at 25 U/min in the common femoral artery (n= 3); (2) intravenous (IV): 5000 U in the popliteal vein at 500 U/min (n= 3), or at 100 U/min (n= 3). Saline was administered in the opposite leg. After the animals were killed, the mass of thrombus in the iliofemoral veins was measured. The pudendoepiploic (PEV), profunda femoris (PF), and popliteal veins (PV) were examined. Thrombosis in the tributaries of the superficial femoral vein (SFVt) was graded according to a three-point scale (0, +, ++). In part II of the study IV administration was further investigated in nine pigs using the following three regimens with 1000 U at 25 U/min serving as the control: (1) 1000 U at 100 U/min, (2) 250 U at 25 U/min, (3) 250 U at 6.25 U/min. Results: All animals survived. In part I median thrombus mass in the test limbs was 1.40 g as compared with 0.25 g in the controls (p= 0.01). PEV, PFV and PV were thrombosed in all limbs infused with thrombin. IV infusion was more effective in inducing thrombosis in both the parent veins (mass 1.32-1.78 g) and SVFt (++ in 4 of 6 legs), as compared with IA infusion (mass 0.0-1.16 g; SFVt ++ in 1 of 3 legs). In part II thrombus mass in axial veins ranged from 1.23 to 2.86 g, and showed no relationship with the dose of thrombin or the rate of infusion. Tributary thrombosis was less extensive with 250 U at 25 U/min than with the other regimens. Conclusion: Slow distal intravenous thrombin infusion in the hind legs of pigs combined with proximal venous occlusion induces thrombosis in the leg veins that closely resembles clinical DVT in distribution

Mars on Earth: Analog basaltic soils and particulates from Lonar Crater, India, include Deccan soil, shocked soil, reworked lithic and glassy ejecta, and both shocked and unshocked baked zones

Science.gov (United States)

Wright, S. P.

2017-12-01

"There is no perfect analog for Mars on Earth" [first line of Hipkin et al. (2013) Icarus, 261-267]. However, fieldwork and corresponding sample analyses from laboratory instrumentation (to proxy field instruments) has resulted in the finding of unique analog materials that suggest that detailed investigations of Lonar Crater, India would be beneficial to the goals of the Mars Program. These are briefly described below as Analog Processes, Materials, and Fieldwork. Analog Processes: The geologic history of Lonar Crater emulates localities on Mars with 1.) flood basaltic volcanism with interlayer development of 2.) baked zones or "boles" and 3.) soil formation. Of six flows, the lower three are aqueously altered by groundwater to produce a range of 4.) alteration products described below. The impact event 570 ka produced a range of 5.) impactites including shocked baked zones, shocked soils, and altered basalt shocked to a range of shock pressures [Kieffer et al., 1976]. Analog Materials: 65 Ma Deccan basalt contains augite and labradorite. Baked zones are higher in hematite and other iron oxides. Soil consists of calcite and organic matter. Several basalts with secondary alteration are listed here and these mirror alteration on Mars: hematite, chlorite, serpentine, zeolite, and palagonite, with varying combinations of these with primary igneous minerals. All of these materials (#1 through 4 above) are shocked to a range of shocked pressures to produce maskelynite, flowing plagioclase glass, vesiculated plagioclase glass, and complete impact melts. Shocked soils contain schlieren calcite amidst comminuted grains of augite, labradorite, and these glasses. Shocked baked zones unsurprisingly have a petrographic texture similar to hornfels, another product of contact metamorphism. Analog Fieldwork: The ejecta consists of two layers: 8 m of lithic breccia with unshocked and fractured basalts under a 1 m suevite consisting of all ranges of shock pressure described above

A Case Study of Deep Vein Thrombosis of the Right Internal Jugular Vein in a Healthy 21-Year-Old Male

Directory of Open Access Journals (Sweden)

Javier Corral

2016-01-01

Full Text Available We are reporting a case of a healthy 21-year-old male, with no significant past medical history, who was found to have an incidental nonocclusive deep vein thrombosis in the right internal jugular vein detected on a head MRI previously ordered for work-up of headaches. A follow-up upper extremity venous Doppler ultrasound confirmed the presence of a partially occlusive deep vein thrombosis in the right jugular vein. The case presented is unique for the reason that the patient is young and has no prior risk factor, personal or familial, for venous thrombosis except for associated polycythemia on clinical presentation.

Tin in granitic melts: The role of melting temperature and protolith composition

Science.gov (United States)

Wolf, Mathias; Romer, Rolf L.; Franz, Leander; López-Moro, Francisco Javier

2018-06-01

Granite bound tin mineralization typically is seen as the result of extreme magmatic fractionation and late exsolution of magmatic fluids. Mineralization, however, also could be obtained at considerably less fractionation if initial melts already had enhanced Sn contents. We present chemical data and results from phase diagram modeling that illustrate the dominant roles of protolith composition, melting conditions, and melt extraction/evolution for the distribution of Sn between melt and restite and, thus, the Sn content of melts. We compare the element partitioning between leucosome and restite of low-temperature and high-temperature migmatites. During low-temperature melting, trace elements partition preferentially into the restite with the possible exception of Sr, Cd, Bi, and Pb, that may be enriched in the melt. In high-temperature melts, Ga, Y, Cd, Sn, REE, Pb, Bi, and U partition preferentially into the melt whereas Sc, V, Cr, Co, Ni, Mo, and Ba stay in the restite. This contrasting behavior is attributed to the stability of trace element sequestering minerals during melt generation. In particular muscovite, biotite, titanite, and rutile act as host phases for Sn and, therefore prevent Sn enrichment in the melt as long as they are stable phases in the restite. As protolith composition controls both the mineral assemblage and modal contents of the various minerals, protolith composition eventually also controls the fertility of a rock during anatexis, restite mineralogy, and partitioning behavior of trace metals. If a particular trace element is sequestered in a phase that is stable during partial melting, the resulting melt is depleted in this element whereas the restite becomes enriched. Melt generation at high temperature may release Sn when Sn-hosts become unstable. If melt has not been lost before the breakdown of Sn-hosts, Sn contents in the melt will increase but never will be high. In contrast, if melt has been lost before the decomposition of Sn

Veins improve fracture toughness of insect wings.

Directory of Open Access Journals (Sweden)

Jan-Henning Dirks

Full Text Available During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect's flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material's resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m. However, the cross veins increase the wing's toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm. This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically 'optimal' solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial 'venous' wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species.

Transvenous liver biopsy via the femoral vein

International Nuclear Information System (INIS)

Khosa, F.; McNulty, J.G.; Hickey, N.; O'Brien, P.; Tobin, A.; Noonan, N.; Ryan, B.; Keeling, P.W.N.; Kelleher, D.P.; McDonald, G.S.A.

2003-01-01

AIM: To study the safety, effectiveness and diagnostic value of transvenous forceps biopsy of the liver in 54 patients with coagulopathy, gross ascites or morbid obesity and suspected liver disease in whom percutaneous liver biopsy was contraindicated. MATERIAL AND METHODS: Forceps biopsy of the liver via the femoral vein was attempted in 54 adult patients with advanced liver disease of unknown aetiology who had coagulation disorders (41 cases), gross ascites (11 cases) or morbid obesity (two cases). In each patient two to six biopsies (average four) were taken using a radial jaw forceps inserted via the right or left femoral vein. RESULTS: The procedure was successful in 53 cases. Hepatic vein catheterization failed in one patient. Adequate liver tissue for diagnosis was obtained in 84% of cases. One patient developed delayed haemorrhage at 12 h from a capsular leak that was undetected during the biopsy procedure. This patient required blood transfusions and laparotomy to control bleeding. There were no deaths in the 53 patients studied. Transient minor chest and shoulder pain was encountered during sheath insertion into a hepatic vein in 23 patients. Three patients developed a femoral vein haematoma, which resolved with conservative treatment. CONCLUSION: Transvenous liver biopsy via the femoral vein is another safe, effective, simple alternative technique of biopsy when the percutaneous route is contraindicated

Computed tomographic evaluation of the portal vein in the hepatomas

Energy Technology Data Exchange (ETDEWEB)

Lee, Kee Hyung; Lee, Seung Chul; Bae, Man Gil; Seo, Heung Suk; Kim, Soon Yong; Lee, Min Ho; Kee, Choon Suhk; Park, Kyung Nam [Hanyang University College of Medicine, Seoul (Korea, Republic of)

1986-10-15

Computed tomography and pornographic findings of 63 patients with hepatoma, undergone hepatic angiography and superior mesenteric pornography for evaluation of tumor and thrombosis of portal vein and determination of indication of transcatheter arterial embolization for palliative treatment of hepatoma from April, 85 to June, 86 in Hanyang university hospital, were reviewed. The results were as follows: 1. In 36 cases, portal vein thrombosis was detected during photography. Nineteen of 37 cases which revealed localized hepatoma in the right lobe of the liver showed portal vein thrombosis; 9 of 11 cases of the left lobe; 8 of 14 cases which were involved in entire liver revealed thrombosis. One case localized in the caudate lobe showed no evidence of invasion to portal vein. 2. Twenty-four of 34 cases with diffuse infiltrative hepatoma revealed portal vein thrombosis and the incidence of portal vein thrombosis in this type were higher than in the cases of the nodular type. 3. The portal vein thrombosis appeared as filling defects of low density in the lumen of the portal veins in CT and they did not reveal contrast enhancement. 4. CT revealed well the evidence of obstructions in the cases of portal vein thrombosis and the findings were well-corresponded to the findings of the superior mesenteric photography. 5. Five of the cases of the portal vein thrombosis were missed in the CT and the causes were considered as due to partial volume effect of enhanced portal vein with partial occlusion or arterioportal shunts. 6. Six of 13 cases with occlusion of main portal vein showed cavernous transformation and they were noted as multiple small enhanced vascularities around the porta hepatis in the CT. According to the results, we conclude that CT is a useful modality to detect the changes of the portal veins in the patients of the hepatoma.

Computed tomographic evaluation of the portal vein in the hepatomas

International Nuclear Information System (INIS)

Lee, Kee Hyung; Lee, Seung Chul; Bae, Man Gil; Seo, Heung Suk; Kim, Soon Yong; Lee, Min Ho; Kee, Choon Suhk; Park, Kyung Nam

1986-01-01

Computed tomography and pornographic findings of 63 patients with hepatoma, undergone hepatic angiography and superior mesenteric pornography for evaluation of tumor and thrombosis of portal vein and determination of indication of transcatheter arterial embolization for palliative treatment of hepatoma from April, 85 to June, 86 in Hanyang university hospital, were reviewed. The results were as follows: 1. In 36 cases, portal vein thrombosis was detected during photography. Nineteen of 37 cases which revealed localized hepatoma in the right lobe of the liver showed portal vein thrombosis; 9 of 11 cases of the left lobe; 8 of 14 cases which were involved in entire liver revealed thrombosis. One case localized in the caudate lobe showed no evidence of invasion to portal vein. 2. Twenty-four of 34 cases with diffuse infiltrative hepatoma revealed portal vein thrombosis and the incidence of portal vein thrombosis in this type were higher than in the cases of the nodular type. 3. The portal vein thrombosis appeared as filling defects of low density in the lumen of the portal veins in CT and they did not reveal contrast enhancement. 4. CT revealed well the evidence of obstructions in the cases of portal vein thrombosis and the findings were well-corresponded to the findings of the superior mesenteric photography. 5. Five of the cases of the portal vein thrombosis were missed in the CT and the causes were considered as due to partial volume effect of enhanced portal vein with partial occlusion or arterioportal shunts. 6. Six of 13 cases with occlusion of main portal vein showed cavernous transformation and they were noted as multiple small enhanced vascularities around the porta hepatis in the CT. According to the results, we conclude that CT is a useful modality to detect the changes of the portal veins in the patients of the hepatoma.

Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

OpenAIRE

Park, Young Ho; Park, Kang Ryoung

2012-01-01

On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger‐vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger‐vein recognition is advantageous in that it involves the use of inexpensive and small devices that are diffic...

A Modified Technique of Basilic Vein Transposition for Haemodialysis

International Nuclear Information System (INIS)

Chaudhary, F. A.; Parvez, Z.

2014-01-01

Objective: To modify the technique of basilic vein transposition for vascular accesss for haemodialysis aiming at better maturation rate, longer survival of fistula and lesser complications. Study Design: Case series. Place and Duration of Study: Shaikh Zayed Hospital and Omer Hospital, Lahore, from February 2008 to July 2011. Methodology: Patients referred for basilic vein transposition for haemodialysis vascular access were prospectively enrolled. The surgical technique included small tracking incisions, an extra 3 - 4 cm of vein length harvesting to avoid tension in the vein in its new course, an oval arteriotomy and a smooth curved pathway, away from vein harvesting incision to avoid entrapment of vein in the scar. Maturation rate, fistula survival and other complications were noted. Results: There was no immediate failure in 51 patients. The complications during follow-up period were infection and thrombosis, bleeding and non-development of basilic vein in 2 patients each; and false aneurysm formation in one. Four patients died during follow-up period. The maturation time was 4.9 A +- 1.1 weeks. The early patency rate was 92.2%, same at 6 months and 90.7% at 12 months. Conclusion: Arteriovenous fistula constructed with modified technique of basilic vein transposition is an acceptable and valid option of vascular access for haemodialysis. (author)

Phase transitions to 120 GPa for shock-compressed pyrolytic and hot-pressed boron nitride

International Nuclear Information System (INIS)

Gust, W.H.; Young, D.A.

1977-01-01

Shock-compression characteristics of two types of hexagonal graphitelike boron nitride have been investigated. Highly oriented very pure pyrolytic boron nitride exhibits shock-velocity versus particle-velocity discontinuities that appear to be manifestations of the initiation of a sluggish phase transition. This transition begins at 20 GPa and is driven to completion (melting) at 75 GPa. Discontinuities in the plot for impure hot-pressed boron nitride indicate initiation at 10 GPa and completion at 20 GPa. The (U/sub s/, U/sub p/) plots follow essentially the same paths for 4.0 < U/sub p/ < 5.2 km/sec. No evidence for a transition to a metalliclike state was seen. Temperature calculations indicate that the material is liquid above approx.80 GPa

Percutaneous transhepatic portal vein stenting in a patient with benign non-transplant postoperative portal vein stenosis: A case report

Directory of Open Access Journals (Sweden)

KS Madhusudhan

2013-01-01

Full Text Available Extrahepatic portal vein stenosis is caused by a variety of benign and malignant diseases and results in development of symptoms due to portal hypertension. Benign post-surgical adhesions causing portal vein stenosis in non-transplant population is an uncommon etiology of portal hypertension. Endovascular treatment of such patients with angioplasty and stenting is uncommonly reported in literature. We report a case of portal hypertension caused by benign postoperative portal vein fibrosis, successfully treated by self-expandable metallic stent.

Physics of Collisionless Shocks Space Plasma Shock Waves

CERN Document Server

Balogh, André

2013-01-01

The present book provides a contemporary systematic treatment of shock waves in high-temperature collisionless plasmas as are encountered in near Earth space and in Astrophysics. It consists of two parts. Part I develops the complete theory of shocks in dilute hot plasmas under the assumption of absence of collisions among the charged particles when the interaction is mediated solely by the self-consistent electromagnetic fields. Such shocks are naturally magnetised implying that the magnetic field plays an important role in their evolution and dynamics. This part treats both subcritical shocks, which dissipate flow energy by generating anomalous resistance or viscosity, and supercritical shocks. The main emphasis is, however, on super-critical shocks where the anomalous dissipation is insufficient to retard the upstream flow. These shocks, depending on the direction of the upstream magnetic field, are distinguished as quasi-perpendicular and quasi-parallel shocks which exhibit different behaviours, reflecti...

Conduit dynamics in transitional rhyolitic activity recorded by tuffisite vein textures from the 2008-2009 Chaitén eruption

Directory of Open Access Journals (Sweden)

Elodie eSaubin

2016-05-01

and sintering preceded ultimate bomb ejection, which then triggered a final bubble nucleation event.Our results highlight how the vesiculation response of magma to decompression events is highly sensitive to the local melt volatile concentration, which is strongly spatially heterogeneous. Repeated opening of pervasive tuffisite vein networks promotes this heterogeneity, allowing juxtaposition of variably volatile-rich magma fragments that are derived from a wide range of depths in the conduit. This process enables efficient but explosive removal of gas from rhyolitic

Olivine/melt transition metal partitioning, melt composition, and melt structure—Melt polymerization and Qn-speciation in alkaline earth silicate systems

Science.gov (United States)

Mysen, Bjorn O.

2008-10-01

The two most abundant network-modifying cations in magmatic liquids are Ca 2+ and Mg 2+. To evaluate the influence of melt structure on exchange of Ca 2+ and Mg 2+ with other geochemically important divalent cations ( m-cations) between coexisting minerals and melts, high-temperature (1470-1650 °C), ambient-pressure (0.1 MPa) forsterite/melt partitioning experiments were carried out in the system Mg 2SiO 4-CaMgSi 2O 6-SiO 2 with ⩽1 wt% m-cations (Mn 2+, Co 2+, and Ni 2+) substituting for Ca 2+ and Mg 2+. The bulk melt NBO/Si-range ( NBO/Si: nonbridging oxygen per silicon) of melt in equilibrium with forsterite was between 1.89 and 2.74. In this NBO/Si-range, the NBO/Si(Ca) (fraction of nonbridging oxygens, NBO, that form bonds with Ca 2+, Ca 2+- NBO) is linearly related to NBO/Si, whereas fraction of Mg 2+- NBO bonds is essentially independent of NBO/Si. For individual m-cations, rate of change of KD( m-Mg) with NBO/Si(Ca) for the exchange equilibrium, mmelt + Mg olivine ⇌ molivine + Mg melt, is linear. KD( m-Mg) decreases as an exponential function of increasing ionic potential, Z/ r2 ( Z: formal electrical charge, r: ionic radius—here calculated with oxygen in sixfold coordination around the divalent cations) of the m-cation. The enthalpy change of the exchange equilibrium, Δ H, decreases linearly with increasing Z/ r2 [Δ H = 261(9)-81(3)· Z/ r2 (Å -2)]. From existing information on (Ca,Mg)O-SiO 2 melt structure at ambient pressure, these relationships are understood by considering the exchange of divalent cations that form bonds with nonbridging oxygen in individual Qn-species in the melts. The negative ∂ KD( m-Mg) /∂( Z/ r2) and ∂(Δ H)/∂( Z/ r2) is because increasing Z/ r2 is because the cations forming bonds with nonbridging oxygen in increasingly depolymerized Qn-species where steric hindrance is decreasingly important. In other words, principles of ionic size/site mismatch commonly observed for trace and minor elements in crystals, also

Applied anatomic study of testicular veins in adult cadavers and in human fetuses

Directory of Open Access Journals (Sweden)

Luciano A. Favorito

2007-04-01

Full Text Available OBJECTIVES: Analyze the anatomic variations of the testicular veins in human cadavers and fetuses. MATERIALS AND METHODS: One hundred male adult cadavers and 24 fetuses were studied. Four anatomic aspects were considered: 1 Number of testicular veins, 2 The local of vein termination, 3 Type and number of collaterals present and 4 Testicular vein termination angle. RESULTS: Cadavers - Right side - One testicular vein occurred in 85% and 2 veins in 5% of the cases. There were communicating veins with the colon in 21% of the cases. Left side - One testicular vein occurred in 82%, two veins in 15%, three veins in 2% and four veins in 1% of the cases. There were communicating veins with the colon in 31% of the cases. Fetuses - Right side -One testicular vein occurred in all cases. This vein drained to the vena cava in 83.3% of the cases, to the junction of the vena cava with the renal vein in 12.5% and to the renal vein in 4.2%. There were communicating veins with the colon in 25% of the cases. Left side - One testicular vein occurred in 66.6% of the cases, and 2 veins in occurred 33.3%. Communicating veins with the colon were found in 41.6% of the cases. CONCLUSION: The testicular vein presents numeric variations and also variations in its local of termination. In approximately 30% of the cases, there are collaterals that communicate the testicular vein with retroperitoneal veins. These anatomic findings can help understanding the origin of varicocele and its recurrence after surgical interventions.

Supracardiac total anomalous pulmonary venous connection with a descending vertical vein.

Science.gov (United States)

Shah, Sejal; Singh, Mukesh; John, Colin; Maheshwari, Sunita

2009-10-01

The commonly used Darling classification for total anomalous pulmonary venous connection (TAPVC) consists of supracardiac, cardiac, infracardiac, and mixed types (Craig et al., Lab Invest 6:44-64, 1967). In supracardiac TAPVC, the common pulmonary vein drains superiorly into the left innominate vein, the superior vena cava, or the azygos vein by way of an ascending vertical vein. We describe a case of supracardiac TAPVC draining into the azygos vein atypically by way of a descending vertical vein.

Induced chorioretinal venous anastomosis in experimental retinal branch vein occlusion.

OpenAIRE

McAllister, I L; Yu, D Y; Vijayasekaran, S; Barry, C; Constable, I

1992-01-01

Iatrogenic retinal vein to choroidal vein anastomoses were created using laser photocoagulation in six of seven dog eyes in which a partial branch retinal vein occlusion had previously been created photochemically. A similar attempt to create an anastomosis was made in six control eyes in which no branch vein occlusion was present. In the eyes in which a branch retinal vein had been created, a venous chorioretinal anastomosis appeared to be present by 3 to 6 weeks. In three control eyes simil...

Permeability and 3-D melt geometry in shear-induced high melt fraction conduits

Science.gov (United States)

Zhu, W.; Cordonnier, B.; Qi, C.; Kohlstedt, D. L.

2017-12-01

Observations of dunite channels in ophiolites and uranium-series disequilibria in mid-ocean ridge basalt suggest that melt transport in the upper mantle beneath mid-ocean ridges is strongly channelized. Formation of high melt fraction conduits could result from mechanical shear, pyroxene dissolution, and lithological partitioning. Deformation experiments (e.g. Holtzman et al., 2003) demonstrate that shear stress causes initially homogeneously distributed melt to segregate into an array of melt-rich bands, flanked by melt-depleted regions. At the same average melt fraction, the permeability of high melt fraction conduits could be orders of magnitude higher than that of their homogenous counterparts. However, it is difficult to determine the permeability of melt-rich bands. Using X-ray synchrotron microtomography, we obtained high-resolution images of 3-dimensional (3-D) melt distribution in a partially molten rock containing shear-induced high melt fraction conduits. Sample CQ0705, an olivine-alkali basalt aggregate with a nominal melt fraction of 4%, was deformed in torsion at a temperature of 1473 K and a confining pressure of 300 MPa to a shear strain of 13.3. A sub-volume of CQ0705 encompassing 3-4 melt-rich bands was imaged. Microtomography data were reduced to binary form so that solid olivine is distinguishable from basalt glass. At a spatial resolution of 160 nm, the 3-D images reveal the shape and connectedness of melt pockets in the melt-rich bands. Thin melt channels formed at grain edges are connected at large melt nodes at grain corners. Initial data analysis shows a clear preferred orientation of melt pockets alignment subparallel to the melt-rich band. We use the experimentally determined geometrical parameters of melt topology to create a digital rock with identical 3-D microstructures. Stokes flow simulations are conducted on the digital rock to obtain the permeability tensor. Using this digital rock physics approach, we determine how deformation

Radiation Retinopathy Associated with Central Retinal Vein Occlusion

Institute of Scientific and Technical Information of China (English)

Yan; Liu; FengWen

2007-01-01

Purpose: To report a case of radiation retinopathy associated with central retinal vein occlusion.Methods: The clinical features and fundus fluorescein angiography of this case were analyzed.Results: The patient had been treated with radiotherapy for her nasopharyngeal carcinoma, and presented with sudden visual loss in the left eye. The funduscopic examination and fluorescein angiography showed the features of radiation retinopathy in both eyes, and central retinal vein occlusion in the left eye.Conclusions: Radiation retinopathy can be associated with central retinal vein occlusion in the same eye, and it seems that the endothelial cell loss caused by radiation retinopathy may lead to retinal vein occlusion.

Disastrous Portal Vein Embolization Turned into a Successful Intervention

Energy Technology Data Exchange (ETDEWEB)

Dobrocky, Tomas, E-mail: tomas.dobrocky@insel.ch [University of Bern, Department of Interventional, Pediatric and Diagnostic Radiology, Inselspital, University Hospital (Switzerland); Kettenbach, Joachim, E-mail: joachim.kettenbach@stpoelten.lknoe.at [Universitätsklinikum St. Pölten-Lilienfeld, Institute of Medical Radiology, Diagnostic, Intervention (Austria); Lopez-Benitez, Ruben, E-mail: Ruben.lopez@insel.ch; Kara, Levent, E-mail: levent.kara@insel.ch [University of Bern, Department of Interventional, Pediatric and Diagnostic Radiology, Inselspital, University Hospital (Switzerland)

2015-10-15

Portal vein embolization (PVE) may be performed before hemihepatectomy to increase the volume of future liver remnant (FLR) and to reduce the risk of postoperative liver insufficiency. We report the case of a 71-year-old patient with hilar cholangiocarcinoma undergoing PVE with access from the right portal vein using a mixture of n-butyl-2-cyanoacrylate and ethiodized oil. During the procedure, nontarget embolization of the left portal vein occurred. An aspiration maneuver of the polymerized plug failed; however, the embolus obstructing portal venous flow in the FLR was successfully relocated into the right portal vein while carefully bypassing the plug with a balloon catheter, inflating the balloon, and pulling the plug into the main right portal vein.

Non-contact finger vein acquisition system using NIR laser

Science.gov (United States)

Kim, Jiman; Kong, Hyoun-Joong; Park, Sangyun; Noh, SeungWoo; Lee, Seung-Rae; Kim, Taejeong; Kim, Hee Chan

2009-02-01

Authentication using finger vein pattern has substantial advantage than other biometrics. Because human vein patterns are hidden inside the skin and tissue, it is hard to forge vein structure. But conventional system using NIR LED array has two drawbacks. First, direct contact with LED array raise sanitary problem. Second, because of discreteness of LEDs, non-uniform illumination exists. We propose non-contact finger vein acquisition system using NIR laser and Laser line generator lens. Laser line generator lens makes evenly distributed line laser from focused laser light. Line laser is aimed on the finger longitudinally. NIR camera was used for image acquisition. 200 index finger vein images from 20 candidates are collected. Same finger vein pattern extraction algorithm was used to evaluate two sets of images. Acquired images from proposed non-contact system do not show any non-uniform illumination in contrary with conventional system. Also results of matching are comparable to conventional system. We developed Non-contact finger vein acquisition system. It can prevent potential cross contamination of skin diseases. Also the system can produce uniformly illuminated images unlike conventional system. With the benefit of non-contact, proposed system shows almost equivalent performance compared with conventional system.

Management of reticular veins and telangiectases.

Science.gov (United States)

Smith, Philip Coleridge

2015-11-01

To review the literature related to the management of reticular varices and telangiectases of the lower limbs to provide guidance on the treatment of these veins. Very few randomised clinical trials are available in this field. A European Guideline has been published on the treatment of reticular varices and telangiectases, which is largely based on the opinion of experts. Older accounts written by individual phlebologists contain extensive advice from their own practice, which is valuable in identifying effective methods of sclerotherapy. All accounts indicate that a history should be taken combined with a clinical and ultrasound examination to establish the full extent of the venous disease. Sclerotherapy is commenced by injecting the larger veins first of all, usually the reticular varices. Later in the same session or in subsequent sessions, telangiectases can be treated by direct injection. Following treatment, the application of class 2 compression stockings for a period of up to three weeks is beneficial but not used universally by all phlebologists. Further sessions can follow at intervals of 2-8 weeks in which small residual veins are treated. Resistant veins can be managed by ultrasound-guided injection of underlying perforating veins and varices. Other treatments including RF diathermy and laser ablation of telangiectases have very limited efficacy in this condition. Sclerotherapy, when used with the correct technique, is the most effective method for the management of reticular varices and telangiectases. © The Author(s) 2015.

A review of the anatomy and clinical significance of adrenal veins.

Science.gov (United States)

Cesmebasi, Alper; Du Plessis, Maira; Iannatuono, Mark; Shah, Sameer; Tubbs, R Shane; Loukas, Marios

2014-11-01

The adrenal veins may present with a multitude of anatomical variants, which surgeons must be aware of when performing adrenalectomies. The adrenal veins originate during the formation of the prerenal inferior vena cava (IVC) and are remnants of the caudal portion of the subcardinal veins, cranial to the subcardinal sinus in the embryo. The many communications between the posterior cardinal, supracardinal, and subcardinal veins of the primordial venous system provide an explanation for the variable anatomy. Most commonly, one central vein drains each adrenal gland. The long left adrenal vein joins the inferior phrenic vein and drains into the left renal vein, while the short right adrenal vein drains immediately into the IVC. Multiple variations exist bilaterally and may pose the risk of surgical complications. Due to the potential for collaterals and accessory adrenal vessels, great caution must be taken during an adrenalectomy. Adrenal venous sampling, the gold standard in diagnosing primary hyperaldosteronism, also requires the clinician to have a thorough knowledge of the adrenal vein anatomy to avoid iatrogenic injury. The adrenal vein acts as an important conduit in portosystemic shunts, thus the nature of the anatomy and hypercoagulable states pose the risk of thrombosis. © 2014 Wiley Periodicals, Inc.

Kinetics of vein graft hyperplasia

International Nuclear Information System (INIS)

Zwolak, R.M.; Adams, M.C.; Clowes, A.W.

1986-01-01

Human aortocoronary vein grafts fail due to accelerated occlusive disease. The possibility that this is related to cellular hyperplasia was investigated in a rabbit model where kinetics of vein graft thickening, endothelial (EC) repair, and smooth muscle cell (SMC) proliferation were measured from 2 days to 24 weeks after implanting jugular vein segments in the carotid artery. Immediately after graft placement focal EC denudation was observed. These defects were repaired within 1 week and did not recur. By 4 weeks intimal area had increased 30 fold from 0.028 +/- 0.004 to 0.705 +/- 0.021 mm 2 , and a 24 weeks was 0.93 +/- 0.21 mm 2 . This response did not produce a reduction in graft lumen area. EC and SMC thymidine-labeling index were measured by en face and cross-section autoradiography after injection of 3 H-thymidine and perfusion fixation. Despite rapid EC surface repair EC labeling index remained elevated and only returned to normal levels at 12 weeks; SMC labeling was 10 fold greater than baseline even at 24 weeks (0.22% vs 0.02%). SMC mass demonstrated morphometrically increased between 2 and 12 weeks. Intimal thickening in vein grafts is due to SMC proliferation and develops after the EC layer has been restored. In contrast, intimal SMC proliferate in damaged arteries when the EC layer is absent and cease when the EC layer is regenerated

Interventional treatment for the occlusive hepatic veins in Budd-Chiari syndrome

International Nuclear Information System (INIS)

Zhang Xitong; Xu Ke; Feng Bo; Su Hongying; Li Hong; Zu Maoheng; Cui Jingguo; Yang Xueliang; Zhao Jinxu; Chen Kai

2003-01-01

Objective: To evaluate the interventional methods for occlusive hepatic veins in Budd-Chiari syndrome and its mid and long-term effects. Methods: Forty-two patients (male 17 cases and female 25 cases) aged from 18 to 57 years old (mean 34.5 years) were studied. The liver functions were Child A in 23 cases, Child B in 6 cases, and Child C in 13 cases, respectively. A total of 92 hepatic veins were occluded. Among them, 29 left hepatic veins, 24 middle hepatic veins, 36 right hepatic veins, and 3 accessory hepatic veins were occluded. Thirty-four patients were accompanied with the stenotic or occlusive inferior vena cave (IVC) . The interventional methods included: (1) recanalization of occlusive hepatic veins (by transjugular, transfemoral, and percutaneous transhepatic route, or the combination of above three methods); (2) percutaneous transluminal angioplasty; (3) self-expanding stent implantation. The occlusive IVC in 32 patients also accepted PTA and/or stent implantation. Results: The successful recanalization was carried out in forty hepatic veins in 40 patients. PTA of occlusive veins was followed by stent implantation in 8 patients. The pressure of hepatic veins dropped from 34.5 cm H 2 O (25.0-48.0 cm H 2 O) to 22.0 cm H 2 O (12.0-35.0 cm H 2 O) after intervention (T=11.50, P < 0.01). The symptoms and pathological signs improved obviously in 32 cases and improved partly in 8 cases. During the follow-up period from 1 month to 54 months (mean 27.5 months), one cases died of liver function failure at one month after intervention. The re-intervention of occlusive veins in two cases were performed and the better results were acquired again. Five cases didn't accept re-intervention. Neither recurrence of symptoms nor re-occlusion of hepatic veins was found in the other 32 patients. Conclusion: (1) Multiple and synthetical interventional methods for the occlusive hepatic veins in Budd-Chiari syndrome can be utilized. (2) The intervention of hepatic vein is mini

Duplex sonography of the near-surface leg veins; Duplexsonographie der oberflaechlichen Beinvenen

Energy Technology Data Exchange (ETDEWEB)

Mendoza, E.

2007-07-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins.

Generating and analyzing synthetic finger vein images

NARCIS (Netherlands)

Hillerström, Fieke; Kumar, Ajay; Veldhuis, Raymond N.J.

2014-01-01

Abstract: The finger-vein biometric offers higher degree of security, personal privacy and strong anti-spoofing capabilities than most other biometric modalities employed today. Emerging privacy concerns with the database acquisition and lack of availability of large scale finger-vein database have

Experimental and numerical study of the micro-spalling of metallic targets subjected to laser shock

International Nuclear Information System (INIS)

Loison, D.

2012-01-01

Micro-spalling is a failure phenomenon consisting in dynamic fragmentation of a material after partial or full melting under intense shock wave loading. High power pulsed lasers are used as shock wave generators in laboratory for scientific and industrial purposes, such as research on inertial confinement fusion. In this context, the production of high velocity fragments can damage the facilities where shock experiments are conducted. This thesis, realized in collaboration with different teams from CEA, aims at understanding and modeling the different processes involved in micro-spalling phenomenon. Experiments to study micro-spalling of laser shock-loaded tin and aluminum targets have been performed. Various and complementary diagnostics (photonic Doppler velocimetry, soft recovery of debris and microtomography) have been used to characterize the ballistic properties (size distributions and velocities) of droplets constituting the micro-spalling cloud. In parallel, phase transition and fragmentation models have been adapted to simulate micro-spalling. These models have been implemented in a code to predict the sizes and velocities of debris. The combination of experimental and numerical results allows characterizing the successive stages of micro-spalling from laser-matter interaction to the ejection of droplets. (author)

Simulations of Converging Shock Collisions for Shock Ignition

Science.gov (United States)

Sauppe, Joshua; Dodd, Evan; Loomis, Eric

2016-10-01

Shock ignition (SI) has been proposed as an alternative to achieving high gain in inertial confinement fusion (ICF) targets. A central hot spot below the ignition threshold is created by an initial compression pulse, and a second laser pulse drives a strong converging shock into the fuel. The collision between the rebounding shock from the compression pulse and the converging shock results in amplification of the converging shock and increases the hot spot pressure above the ignition threshold. We investigate shock collision in SI drive schemes for cylindrical targets with a polystyrene foam interior using radiation-hydrodynamics simulations with the RAGE code. The configuration is similar to previous targets fielded on the Omega laser. The CH interior results in a lower convergence ratio and the cylindrical geometry facilitates visualization of the shock transit using an axial X-ray backlighter, both of which are important for comparison to potential experimental measurements. One-dimensional simulations are used to determine shock timing, and the effects of low mode asymmetries in 2D computations are also quantified. LA-UR-16-24773.

Complications of umbilical vein catherisation. Case Report

International Nuclear Information System (INIS)

Bothur-Nowacka, J.; Czech-Kowalska, J.; Gruszfeld, D.; Nowakowska-Rysz, M.; Dobrzanska, A.; Kosciesza, A.; Polnik, D.

2011-01-01

Umbilical vein catheterization is a relatively easy procedure performed routinely on the neonate intensive care units. It provides a fast central vein access, but some complications have been described in the literature. Case Reports: We presented a case report of a premature infant (34 hbd) with extravasation of the parenteral nutrition and drugs to the liver after umbilical vein catheterization. Fever and increasing biochemical markers of infection were observed. USG revealed a heterogenic, well-limited space of 4 cm in diameter, located in the right lobe of the liver. CT excluded liver abscess. Considering neoplastic process or incorrect location of the catheter of the central vein, we performed liver biopsy. Results: Cytological and biochemical analysis of the aspirated fluid revealed extravasation of parenteral nutrition to the liver.Our case confirms the necessity of controlling a proper location of the central catheter right after its insertion and during hospitalization. (authors)

Effect of coolant velocity on the fragmentation of single melt drops in water

International Nuclear Information System (INIS)

Cunningham, M.H.; Frost, D.L.

1997-01-01

Flash X-ray radiography and high-speed photography are used to investigate the effect of the coolant velocity on the fine fragmentation of molten tin drops in water. A water cannot is used to accelerate the water to a constant speed of up to 30 m/s. The water is accelerated with a double piston arrangement including a foam shock absorber to eliminate the formation of a shock wave. In this way, the effect of coolant velocity on drop breakup is investigated in the absence of the strong shock wave that is present in most earlier studies. The results show that there is a transition from thermal to hydrodynamic fragmentation through an intermediate stage in which the drops initially undergo hydrodynamic fragmentation followed by the formation of a vapour bubble. For low velocities (9 m/s) this bubble collapses, fragmenting the remainder of the drop while at greater velocities (15 m/s) the drop breaks up within the bubble before it condenses. At 22 and 28 m/s there is no vapour formation and the drop fragments due to hydrodynamic effects. Quantitative analysis of the radiographs is used to determine the mass distribution of the melt during the drop fragmentation. Comparison with earlier work in which the ambient flow is preceded by a strong shock wave indicates that the transition from thermal to hydrodynamic breakup is strongly dependent on the characteristics of the pressure field experienced by the drop. (author)

[Treatment of nontumoral portal vein thrombosis in cirrhosis].

Science.gov (United States)

Bañares, Rafael; Catalina, María-Vega

2014-07-01

Portal vein thrombosis in cirrhosis is a relatively common complication associated with the presence of an accompanying prothrombotic phenotype of advanced cirrhosis. The consequences of portal vein thrombosis are relevant because it can be associated with impaired hepatic function, might contraindicate hepatic transplantation and could increase morbidity in the surgical procedure. There is controversy concerning the most effective treatment of portal vein thrombosis, which is based on information that is seldom robust and whose primary objective is to achieve a return to vessel patency. Various studies have suggested that starting anticoagulation therapy early is associated with portal vein repatency more frequently than without treatment and has a low rate of complications. There are no proven data on the type of anticoagulant (low-molecular-weight heparins or dicoumarin agents) and the treatment duration. The implementation of TIPS is technically feasible in thrombosis without cavernous transformation and is associated with portal vein recanalization in a significant proportion of cases. Thrombolytic therapy does not appear to present an adequate balance between efficacy and safety; its use is therefore not supported for this indication. The proper definition of treatment for portal vein thrombosis requires properly designed studies to delimit the efficacy and safety of the various alternatives. Copyright © 2014 Elsevier España, S.L. All rights reserved.

Catheter Displacement into Inferior Epigastric Vein Causing Local Phlebitis and Cellulitis

Directory of Open Access Journals (Sweden)

Noriko Hattori

2012-01-01

Full Text Available Catheter insertion for intravenous hyperalimentation is a commonly and widely used clinical technique. When compared with the incidence of complications associated with insertions into the internal jugular vein or the subclavian vein, complications associated with insertions into the femoral vein are less frequent. In this paper, we describe a very rare complication of femoral vein catheter insertion—namely, catheter displacement into the inferior epigastric vein.

Renal Vein Reconstruction for Harvesting Injury in Kidney Transplantation

Directory of Open Access Journals (Sweden)

Birkan Bozkurt

2014-03-01

Full Text Available Kidney transplantation is the best treatment choice in the end-stage renal disease. In the renal transplantation, renal vein damage or shortness which occurs during cadaveric or living donor nephrectomy causes technical difficulties for surgeons. The lack of the donors already especially cadaveric, the acquirement of the graft, gets very much importance. In this report, it is aimed to share the clinical experiment by which it seen, how anastomosis can become appropriate by using the renal vein which is damaged in the way that anastomosis cannot be done anyway by using cadaveric vena cava graft. The renal vein brought to length for anostomosis which is repaired by using cadaveric vena cava graft, is anastomosed successfully by becoming an end-to-side of the external iliac vein of the recipient. Vascular anastomoses are applied easily in technique. The time of the warm ischemia was under 2 hours and the kidney was functional in the post-operative period. Renal vein trombosis was not observed. The renal vein damage occured during cadaveric or living donor nephrectomy, can be repaired by some methods. In the kidneys in which vein requirement is done, the success rates are rather high although acute tubular necrosis and delayed function can be seen more.

A study on the development of engineering plastic piston used in the shock absorber

Science.gov (United States)

Kim, Young-Ho; Bae, Won-Byong; Lim, Dong-Ju; Suh, Yun-Soo

1998-08-01

A piston is an important component of the shock absorber which determines comfortable riding and handling. Conventional piston is made of metal powder that is pressed in a mold, and then sintered at high temperatures below the melting point before machining processes such as drilling, sizing and teflon banding. This study aims at cutting down cost and weight, and improving the process by replacing the traditional sintering process used for manufacturing the shock absorber with the injection molding process adopting engineering plastics as raw material. To analyze the injection molding process, we used the commercial program, MOLDFLOW, and obtained an optimal combination of the process parameters. In addition, by comparing the engineering plastic piston with the metal powder piston through the formability and the performance experiments, we confirmed the availability of this alternative process suggested.

Anomalous mass transport in Au/304 stainless steel powder under shock loading

Energy Technology Data Exchange (ETDEWEB)

Staudhammer, Karl P.

2004-01-01

Dynamic deformation experiments on gold plated 304L stainless steel powders were undertaken using a axial symmetrical implosion geometry. These experiments utilized pressures of 0.08 to 1.0 Mbar and contained a symmetric radial melt region along the central axis of the sample holder. To understand the role of deformation in a porous material, the pressure, and temperature as well as the deformation heat and associated defects must be accounted for. Using a strain controllable shock loading design it was possible to separate and control independently strain and pressure. Thus enabling the ability to control the added heat from the deformation process undergoing compaction/consolidation of the powder. When the added heat of consolidation deformation exceeds the melt temperature of the 304 powders, a melt zone results that can consume large regions of the compact. It is within these regions that very high diffusion of gold into the powder occurs. These anomalous increases have been observed via optical microscopy, scanning electron microscopy and EDAX measurements. Values exceeding 1200 m/sec have been measured and correlated to the powder sizes, size distribution and packing density, concomitant with sample container strains ranging from 2.0% to 26%.

Shock Dynamics in Stellar Outbursts. I. Shock Formation

Energy Technology Data Exchange (ETDEWEB)

Ro, Stephen; Matzner, Christopher D., E-mail: ro@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)

2017-05-20

Wave-driven outflows and non-disruptive explosions have been implicated in pre-supernova outbursts, supernova impostors, luminous blue variable eruptions, and some narrow-line and superluminous supernovae. To model these events, we investigate the dynamics of stars set in motion by strong acoustic pulses and wave trains, focusing on nonlinear wave propagation, shock formation, and an early phase of the development of a weak shock. We identify the shock formation radius, showing that a heuristic estimate based on crossing characteristics matches an exact expansion around the wave front and verifying both with numerical experiments. Our general analytical condition for shock formation applies to one-dimensional motions within any static environment, including both eruptions and implosions. We also consider the early phase of shock energy dissipation. We find that waves of super-Eddington acoustic luminosity always create shocks, rather than damping by radiative diffusion. Therefore, shock formation is integral to super-Eddington outbursts.

Congestive index of portal vein

International Nuclear Information System (INIS)

Kim, Won Ho; Kim, H. K.; Lee, S. C.; Han, S. H.; Han, K. H.; Chung, J. B.; Choi, H. J.

1989-01-01

In patients with portal hypertension, the blood flow volume is maintained despite decreased blood flow velocity due to enlargement of the vascular cross sectional area. Thus, the 'congestion index' of the portal vein, which is the ratio between the cross sectional area (cm2) and the blood flow velocity (cm/sec) determined by a Doppler ultrasonography, may be a sensitive index by which to assess portal hypertension. We performed Doppler ultrasonography on 24 normal subjects, 14 patients with biopsy proved chronic active hepatitis and 55 patients with liver cirrhosis in order to assess the diagnostic value of the congestion index. The cross sectional area of the portal vein was significantly enlarged and the mean blood flow velocity was significantly reduced in patients with liver cirrhosis compared with controls. However, the blood flow volume was no difference. The congestion index of the portal vein was significantly increased in patients with liver cirrhosis (0.113+0.035) compared with patients with chronic active hepatitis(0.078+0.029) (p<0.001) and controls (0.053+0.016) (p<0.001). The sensitivity, specificity and predictability of the congestion index for detection of patients with the cirrhosis of the liver were 76.4%, 100% and 100% respectively, when the normal range was set at mean+2SD. The results suggest that the congestion index of the portal vein may pla a significant role in diagnosis of portal hypertensive patients

Evaluation of Melt Behavior with initial Melt Velocity under SFR Severe Accidents

Energy Technology Data Exchange (ETDEWEB)

Heo, Hyo; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of); Jerng, Dong Wook [Chung-Ang Univ, Seoul (Korea, Republic of)

2015-10-15

In the current Korean sodium-cooled fast reactor (SFR) program, early dispersion of the molten metallic fuel within a subchannel is suggested as one of the inherent safety strategies for the initiating phase of hypothetical core disruptive accident (HCDA). The safety strategy provides negative reactivity driven by the melt dispersal, so it could reduce the possibility of the recriticality event under a severe triple or more fault scenario for SFR. Since the behavior of the melt dispersion is unpredictable, it depends on the accident condition, particularly core region. While the voided coolant channel region is usually developed in the inner core, the unvoided coolant channel region is formed in the outer core. It is important to confirm the fuel dispersion with the core region, but there are not sufficient existing studies for them. From the existing studies, the coolant vapor pressure is considered as one of driving force to move the melt towards outside of the core. There is a complexity of the phenomena during intermixing of the melt with the coolant after the horizontal melt injections. It is too difficult to understand the several combined mechanisms related to the melt dispersion and the fragmentation. Thus, it could be worthwhile to study the horizontal melt injections at lower temperature as a preliminary study in order to identify the melt dispersion phenomena. For this reason, it is required to clarify whether the coolant vapor pressure is the driving force of the melt dispersion with the core region. The specific conditions to be well dispersed for the molten metallic fuel were discussed in the experiments with the simulant materials. The each melt behavior was compared to evaluate the melt dispersion under the coolant void condition and the boiling condition. As the results, the following results are remarked: 1. The upward melt dispersion did not occur for a given melt and coolant temperature in the nonboiling range. Over current range of conditions

Evaluation of Melt Behavior with initial Melt Velocity under SFR Severe Accidents

International Nuclear Information System (INIS)

Heo, Hyo; Bang, In Cheol; Jerng, Dong Wook

2015-01-01

In the current Korean sodium-cooled fast reactor (SFR) program, early dispersion of the molten metallic fuel within a subchannel is suggested as one of the inherent safety strategies for the initiating phase of hypothetical core disruptive accident (HCDA). The safety strategy provides negative reactivity driven by the melt dispersal, so it could reduce the possibility of the recriticality event under a severe triple or more fault scenario for SFR. Since the behavior of the melt dispersion is unpredictable, it depends on the accident condition, particularly core region. While the voided coolant channel region is usually developed in the inner core, the unvoided coolant channel region is formed in the outer core. It is important to confirm the fuel dispersion with the core region, but there are not sufficient existing studies for them. From the existing studies, the coolant vapor pressure is considered as one of driving force to move the melt towards outside of the core. There is a complexity of the phenomena during intermixing of the melt with the coolant after the horizontal melt injections. It is too difficult to understand the several combined mechanisms related to the melt dispersion and the fragmentation. Thus, it could be worthwhile to study the horizontal melt injections at lower temperature as a preliminary study in order to identify the melt dispersion phenomena. For this reason, it is required to clarify whether the coolant vapor pressure is the driving force of the melt dispersion with the core region. The specific conditions to be well dispersed for the molten metallic fuel were discussed in the experiments with the simulant materials. The each melt behavior was compared to evaluate the melt dispersion under the coolant void condition and the boiling condition. As the results, the following results are remarked: 1. The upward melt dispersion did not occur for a given melt and coolant temperature in the nonboiling range. Over current range of conditions

Phenotypic heterogeneity in the endothelium of the human vortex vein system.

Science.gov (United States)

Yu, Paula K; Tan, Priscilla E Z; Cringle, Stephen J; McAllister, Ian L; Yu, Dao-Yi

2013-10-01

The vortex vein system is the drainage pathway for the choroidal circulation and serves an important function in the effective drainage of the exceptionally high blood flow from the choroidal circulation. As there are only 4-6 vortex veins, a large volume of blood must be drained from many choroidal veins into each individual vortex vein. The vortex vein system must also cope with passing through tissues of different rigidity and significant pressure gradient as it transverses from the intrao-cular to the extra-ocular compartments. However, little is known about how the vortex vein system works under such complex situations in both physiological and pathological condition. Endothelial cells play a vital role in other vascular systems, but they have not been studied in detail in the vortex vein system. The purpose of this study is to characterise the intracellular structures and morphology in both the intra-and extra-ocular regions of the human vortex vein system. We hypothesise the presence of endothelial phenotypic heterogeneity through the vortex vein system. The inferior temporal vortex vein system from human donor eyes were obtained and studied histologically using confocal microscopy. The f-actin cytoskeleton and nuclei were labelled using Alexa Fluor conjugated Phalloidin and YO-PRO-1. Eight regions of the vortex vein system were examined with the venous endothelium studied in detail with quantitative data obtained for endothelial cell and nuclei size and shape. Significant endothelial phenotypic heterogeneity was found throughout the vortex vein system with the most obvious differences observed between the ampulla and its downstream regions. Variation in the distribution pattern of smooth muscle cells, in particular the absence of smooth muscle cells around the ampulla, was noted. Our results suggest the presence of significantly different haemodynamic forces in different regions of the vortex vein system and indicate that the vortex vein system may play

Finger Vein Recognition Based on Personalized Weight Maps

Science.gov (United States)

Yang, Gongping; Xiao, Rongyang; Yin, Yilong; Yang, Lu

2013-01-01

Finger vein recognition is a promising biometric recognition technology, which verifies identities via the vein patterns in the fingers. Binary pattern based methods were thoroughly studied in order to cope with the difficulties of extracting the blood vessel network. However, current binary pattern based finger vein matching methods treat every bit of feature codes derived from different image of various individuals as equally important and assign the same weight value to them. In this paper, we propose a finger vein recognition method based on personalized weight maps (PWMs). The different bits have different weight values according to their stabilities in a certain number of training samples from an individual. Firstly we present the concept of PWM, and then propose the finger vein recognition framework, which mainly consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PWM achieves not only better performance, but also high robustness and reliability. In addition, PWM can be used as a general framework for binary pattern based recognition. PMID:24025556

Finger Vein Recognition Based on Personalized Weight Maps

Directory of Open Access Journals (Sweden)

Lu Yang

2013-09-01

Full Text Available Finger vein recognition is a promising biometric recognition technology, which verifies identities via the vein patterns in the fingers. Binary pattern based methods were thoroughly studied in order to cope with the difficulties of extracting the blood vessel network. However, current binary pattern based finger vein matching methods treat every bit of feature codes derived from different image of various individuals as equally important and assign the same weight value to them. In this paper, we propose a finger vein recognition method based on personalized weight maps (PWMs. The different bits have different weight values according to their stabilities in a certain number of training samples from an individual. Firstly we present the concept of PWM, and then propose the finger vein recognition framework, which mainly consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PWM achieves not only better performance, but also high robustness and reliability. In addition, PWM can be used as a general framework for binary pattern based recognition.

Deep Vein Thrombosis

Centers for Disease Control (CDC) Podcasts

2012-04-05

This podcast discusses the risk for deep vein thrombosis in long-distance travelers and ways to minimize that risk.  Created: 4/5/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 4/5/2012.

Characterization of a porcine model of chronic superficial varicose veins.

Science.gov (United States)

Jones, Gregory T; Grant, Mark W; Thomson, Ian A; Hill, B Geraldine; van Rij, André M

2009-06-01

Previous animal models of venous disease, while inducing venous hypertension and valvular insufficiency, do not produce superficial varicose veins. In this study, we aimed to develop and characterize a pig-based model of superficial varicose veins. Right femoral arteriovenous fistulae (AVF) were surgically fashioned in young adult pigs. Animals were examined at postoperative times up to 15 weeks to determine the development of varicose veins and measurement of both blood pressure and flow velocities within the superficial thigh veins. Histology and vascular corrosion casts were used to characterize the resulting structural venous alterations. Porcine pathophysiological features were compared with those of human primary superficial varicose veins. Gross superficial varicosities developed over the ipsilateral medial thigh region after an initial lag period of 1-2 weeks. Veins demonstrated retrograde filling with valvular incompetence, and a moderate, non-pulsatile, venous hypertension, which was altered by changes in posture and Valsalva. Venous blood flow velocities were elevated to 15-30 cm/s in varicose veins. Structurally, pig varicose veins were enlarged, tortuous, had valvular degeneration, and regions of focal medial atrophy with or without overlying intimal thickening. The superficial varicose veins, which developed within this model, have a pathophysiology that is consistent with that observed in humans. The porcine femoral AVF model is proposed as a suitable experimental model to evaluate the pathobiology of superficial venous disease. It may also be suitable for the evaluation of treatment interventions including drug therapy.

[Portal perfusion with right gastroepiploic vein flow in liver transplant].

Science.gov (United States)

Mendoza-Sánchez, Federico; Javier-Haro, Francisco; Mendoza-Medina, Diego Federico; González-Ojeda, Alejandro; Cortés-Lares, José Antonio; Fuentes-Orozco, Clotilde

Liver transplantation in patients with liver cirrhosis, portal vein thrombosis, and cavernous transformation of the portal vein, is a complex procedure with high possibility of liver graft dysfunction. It is performed in 2-19% of all liver transplants, and has a significantly high mortality rate in the post-operative period. Other procedures to maintain portal perfusion have been described, however there are no reports of liver graft perfusion using right gastroepiploic vein. A 20 year-old female diagnosed with cryptogenic cirrhosis, with a Child-Pugh score of 7 points (class "B"), and MELD score of 14 points, with thrombosis and cavernous transformation of the portal vein, severe portal hypertension, splenomegaly, a history of upper gastrointestinal bleeding due to oesophageal varices, and left renal agenesis. The preoperative evaluation for liver transplantation was completed, and the right gastroepiploic vein of 1-cm diameter was observed draining to the infrahepatic inferior vena cava and right suprarenal vein. An orthotopic liver transplantation was performed from a non-living donor (deceased on January 30, 2005) using the Piggy-Back technique. Portal vein perfusion was maintained using the right gastroepiploic vein, and the outcome was satisfactory. The patient was discharged 13 days after surgery. Liver transplantation was performed satisfactorily, obtaining an acceptable outcome. In this case, the portal perfusion had adequate blood flow through the right gastroepiploic vein. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

A study of images of Projective Angles of pulmonary veins

Energy Technology Data Exchange (ETDEWEB)

Wang Jue [Beijing Anzhen Hospital, Beijing (China); Zhaoqi, Zhang [Beijing Anzhen Hospital, Beijing (China)], E-mail: zhaoqi5000@vip.sohu.com; Yu Wei; Miao Cuilian; Yan Zixu; Zhao Yike [Beijing Anzhen Hospital, Beijing (China)

2009-09-15

Aims: In images of magnetic resonance and computed tomography (CT) there are visible angles between pulmonary veins and the coronary, transversal or sagittal section of body. In this study these angles are measured and defined as Projective Angles of pulmonary veins. Several possible influential factors and characters of distribution are studied and analyzed for a better understanding of this imaging anatomic character of pulmonary veins. And it could be the anatomic base of adjusting correctly the angle of the central X-ray of the angiography of pulmonary veins undergoing the catheter ablation of atrial fibrillation (AF). Method: Images of contrast enhanced magnetic resonance angiography (CEMRA) and contrast enhanced computer tomography (CECT) of the left atrium and pulmonary veins of 137 health objects and patients with atrial fibrillation (AF) are processed with the technique of post-processing, and Projective Angles to the coronary and transversal sections are measured and analyzed statistically. Result: Project Angles of pulmonary veins are one of real and steady imaging anatomic characteristics of pulmonary veins. The statistical distribution of variables is relatively concentrated, with a fairly good representation of average value. It is possible to improve the angle of the central X-ray according to the average value in the selective angiography of pulmonary veins undergoing the catheter ablation of AF.

Adrenal vein catheterization. Anatomic considerations

Energy Technology Data Exchange (ETDEWEB)

El-Sherief, M.A. (Akademiska Sjukhuset, Uppsala (Sweden))

1982-01-01

Twenty post-mortem specimens and 93 phlebographies (56 right side, 37 left side) from 44 patients were investigated with respect to the adrenal venous anatomy. At autopsy, the venous orifices displayed in the area of adrenal drainage were injected bilaterally to identify the adrenal vein(s), the surrounding channels and the presence of interconnections. The findings were correlated with those at clinical phlebography, and the different sources of error were elicited. These were mainly found on the right side. Some guidelines are suggested in the hope that these will contribute to eliminate misconceptions.

Treatment of hepatic encephalopathy by retrograde transcaval coil embolization of an ileal vein-to-right gonadal vein portosystemic shunt

International Nuclear Information System (INIS)

Nishie, Akihiro; Yoshimitsu, Kengo; Honda, Hiroshi; Kaneko, Kuniyuki; Kuroiwa, Toshiro; Fukuya, Tatsuro; Irie, Hiroyuki; Ninomiya, Toshiharu; Yoshimitsu, Takahiro; Hirakata, Hideki; Okuda, Seiya; Masuda, Kouji

1997-01-01

A 43-year-old non-cirrhotic woman suffered from encephalopathy caused by an extrahepatic portosystemic shunt between the ileal vein and inferior vena cava via the right gonadal vein. Percutaneous transcatheter embolization with stainless steel coils was performed by the retrograde systemic venous approach. Encephalopathy improved dramatically

Is the inferior vena cava diameter measured by bedside ultrasonography valuable in estimating the intravascular volume in patients with septic shock?

Directory of Open Access Journals (Sweden)

Mortaza Talebi Doluie

2016-07-01

Full Text Available Introduction:Resuscitation should be initiated immediately in shock. Early goal-directed therapy is an established algorithm for the resuscitation in septic shock. The first step is to maintain cardiac preload. Central venous pressure (CVP plays an important role in goal-directed therapy. Central venous catheterization is invasive and time-consuming in emergency conditions. There are some alternative and noninvasive methods for estimating the intravascular volume such as measuring the inferior vena cava (IVC diameter by ultrasonography. Methods: We searched PubMed, Google scholar, and Scopus databases with keywords (central venous pressure OR venous pressure OR CVP AND (ultrasonography OR sonography AND (sepsis OR septic shock AND (inferior vena cava OR IVC.Result: The search resulted in 2550 articles. The articles were appraised regarding the relevance, type of article, and statistical methods. Finally, 12 articles were selected. The number of patients was between 30 and 83 cases (mean age=57-67 years, intubated and non-intubated in each study. The IVC diameter was measured in respiratory cycle by bedside ultrasonography in longitudinal subxiphoid view and caval index was calculated, then they were compared with the CVP measured by central venous catheter.Discussion: CVP is an indicator of intravascular fluid status and right heart function. CVP measurement is an invasive method and of course with some complications. The IVC is the biggest vein of venous system with low-pressure; expansion of the vein reflects intravascular volume.Conclusion: It seems that IVC diameter measured by ultrasonography could be used as an alternative method for the determination of CVP in the emergency or critical patients.

Vein-type uranium deposits

International Nuclear Information System (INIS)

Rich, R.A.; Holland, H.D.; Petersen, U.

1975-01-01

A critical review is presented of published data bearing on the mineralogy, paragenesis, geochemistry, and origin of veiw-type uranium deposits. Its aim is to serve as a starting point for new research and as a basis for the development of new exploration strategies. During the formation of both vein and sandstone types of deposits uranium seems to have been dissolved by and transported in rather oxidized solutions, and deposited where these solutions encountered reducing agents such as carbon, sulfides, ferrous minerals and hydrocarbons. Granitic rocks abnormally enriched in uranium have apparently been the most common source for uranium in vein-type deposits. Oxidizing solutions have been derived either from the surface or from depth. Surface solutions saturated with atmospheric oxygen have frequently passed through red bed or clean sandstone conduits on their way to and from uranium source rocks. Deep solutions of non-surface origin have apparently become sufficiently oxidizing by passage through and equilibration with red beds. The common association of clean sandstones or red beds with uranium-rich granites in the vicinity of vein-type uranium deposits is probably not fortuitous, and areas where these rock types are found together are considered particularly favorable targets for uranium exploration

Interposition vein cuffs.

Science.gov (United States)

Harris, P; Da Silva, T; How, T

1996-01-01

A vein cuff interposed at the distal anastomosis between a prosthetic vascular graft and a recipient infrageniculate artery improves the chances of continued patency of the graft, at least in the short and medium term. The mode of effect appears to be suppression or modification of anastomotic myointimal hyperplasia (MIH). In the event of graft failure the recipient artery and run-off vessels remain free from MIH and their patency is preserved thereby improving the prospects for further vascular reconstruction and limb salvage. The mechanisms by which interposition vein cuffs might modulate MIH are reviewed. Experimental evidence is described to show that the geometry of a cuffed anastomosis promotes a characteristic haemodynamic flow structure with a stable vortex. It is suggested that this vortex exerts greater shear stress upon the wall of the artery than the normal laminar flow observed in conventional anastomoses. High shear stress is known to inhibit MIH.

Rapakivi texture formation via disequilibrium melting in a contact partial melt zone, Antarctica

Science.gov (United States)

Currier, R. M.

2017-12-01

In the McMurdo Dry Valleys of Antarctica, a Jurassic aged dolerite sill induced partial melting of granite in the shallow crust. The melt zone can be traced in full, from high degrees of melting (>60%) along the dolerite contact, to no apparent signs of melting, 10s of meters above the contact. Within this melt zone, the well-known rapakivi texture is found, arrested in various stages of development. High above the contact, and at low degrees of melting, K-feldspar crystals are slightly rounded and unmantled. In the lower half of the melt zone, mantles of cellular textured plagioclase appear on K-feldspar, and thicken towards the contact heat source. At the highest degrees of melting, cellular-textured plagioclase completely replaces restitic K-feldspar. Because of the complete exposure and intact context, the leading models of rapakivi texture formation can be tested against this system. The previously proposed mechanisms of subisothermal decompression, magma-mixing, and hydrothermal exsolution all fail to adequately describe rapakivi generation in this melt zone. Preferred here is a closed system model that invokes the production of a heterogeneous, disequilibrium melt through rapid heating, followed by calcium and sodium rich melt reacting in a peritectic fashion with restitic K-feldspar crystals. This peritectic reaction results in the production of plagioclase of andesine-oligoclase composition—which is consistent with not just mantles in the melt zone, but globally as well. The thickness of the mantle is diffusion limited, and thus a measure of the diffusive length scale of sodium and calcium over the time scale of melting. Thermal modeling provides a time scale of melting that is consistent with the thickness of observed mantles. Lastly, the distribution of mantled feldspars is highly ordered in this melt zone, but if it were mobilized and homogenized—mixing together cellular plagioclase, mantled feldspars, and unmantled feldspars—the result would be

Internal jugular vein: Peripheral vein adrenocorticotropic hormone ratio in patients with adrenocorticotropic hormone-dependent Cushing′s syndrome: Ratio calculated from one adrenocorticotropic hormone sample each from right and left internal jugular vein during corticotrophin releasing hormone stimulation test

Directory of Open Access Journals (Sweden)

Sachin Chittawar

2013-01-01

Full Text Available Background: Demonstration of central: Peripheral adrenocorticotropic hormone (ACTH gradient is important for diagnosis of Cushing′s disease. Aim: The aim was to assess the utility of internal jugular vein (IJV: Peripheral vein ACTH ratio for diagnosis of Cushing′s disease. Materials and Methods: Patients with ACTH-dependent Cushing′s syndrome (CS patients were the subjects for this study. One blood sample each was collected from right and left IJV following intravenous hCRH at 3 and 5 min, respectively. A simultaneous peripheral vein sample was also collected with each IJV sample for calculation of IJV: Peripheral vein ACTH ratio. IJV sample collection was done under ultrasound guidance. ACTH was assayed using electrochemiluminescence immunoassay (ECLIA. Results: Thirty-two patients participated in this study. The IJV: Peripheral vein ACTH ratio ranged from 1.07 to 6.99 ( n = 32. It was more than 1.6 in 23 patients. Cushing′s disease could be confirmed in 20 of the 23 cases with IJV: Peripheral vein ratio more than 1.6. Four patients with Cushing′s disease and 2 patients with ectopic ACTH syndrome had IJV: Peripheral vein ACTH ratio less than 1.6. Six cases with unknown ACTH source were excluded for calculation of sensitivity and specificity of the test. Conclusion: IJV: Peripheral vein ACTH ratio calculated from a single sample from each IJV obtained after hCRH had 83% sensitivity and 100% specificity for diagnosis of CD.

Convolutional Neural Network-Based Finger-Vein Recognition Using NIR Image Sensors.

Science.gov (United States)

Hong, Hyung Gil; Lee, Min Beom; Park, Kang Ryoung

2017-06-06

Conventional finger-vein recognition systems perform recognition based on the finger-vein lines extracted from the input images or image enhancement, and texture feature extraction from the finger-vein images. In these cases, however, the inaccurate detection of finger-vein lines lowers the recognition accuracy. In the case of texture feature extraction, the developer must experimentally decide on a form of the optimal filter for extraction considering the characteristics of the image database. To address this problem, this research proposes a finger-vein recognition method that is robust to various database types and environmental changes based on the convolutional neural network (CNN). In the experiments using the two finger-vein databases constructed in this research and the SDUMLA-HMT finger-vein database, which is an open database, the method proposed in this research showed a better performance compared to the conventional methods.

The vein collar

DEFF Research Database (Denmark)

Lundgren, F; Schroeder, Torben Veith

2012-01-01

Randomized studies evaluating the effect of a vein collar at the distal anastomosis of PTFE-grafts show conflicting results. The study of the Joint Vascular Research Group (JVRG) of UK found improved primary patency while the Scandinavian Miller Collar Study (SCAMICOS) found neither any effect...

Mesenteric vein thrombosis after percitaneous transhepatic portal vein catheterisation for the localisation of an insulinoma

International Nuclear Information System (INIS)

Luska, G.; Langer, H.E.; Le Blanc, S.; Medizinische Hochschule Hannover

1984-01-01

The authors report on a fatal mesenteric vein thrombosis following an uncomplicated percutaneous transhepatic portal vein catheterisation for the localisation of an insulinoma. Several hours after the procedure the patient developed an acute abdomen. An emergency laparotomy revealed a haemorrhagic infarct of the ileum. The resected specimen showed an acute phlebitis with fresh thrombus. The cause of the phlebothrombosis was thought to be intimal damage from high osmolar contrast medium. There was no evidence of damage due to the catheder, either on the phlebogram or pathologically. (orig.) [de

Experimental results for TiO2 melting and release using cold crucible melting

International Nuclear Information System (INIS)

Hong, S. W.; Min, B. T.; Park, I. G.; Kim, H. D.

2000-01-01

To simulate the severe accident phenomena using the real reactor material which melting point is about 2,800K, the melting and release method for materials with high melting point should be developed. This paper discusses the test results for TiO 2 materials using the cold crucible melting method to study the melting and release method of actual corium. To melt and release of few kg of TiO2, the experimental facility is manufactured through proper selection of design parameters such as frequency and capacity of R.F generator, crucible size and capacity of coolant. The melting and release of TiO 2 has been successfully performed in the cold crucible of 15cm in inner diameter and 30cm in height with 30kW RF power generator of 370 KHz. In the melt delivery experiment, about 2.6kg of molten TiO2, 60% of initial charged mass, is released. Rest of it is remained in the watercage in form of the rubble crust formed at the top of crucible and melt crust formed at the interface between the water-cage and melt. Especially, in the melt release test, the location of the working coil is important to make the thin crust at the bottom of the crucible

Incidental retroaortic left innominate vein in adult patient

Directory of Open Access Journals (Sweden)

Alexandre Semionov, MD, PhD

2017-09-01

Full Text Available Retro-aortic left innominate vein is a rare vascular abnormality, usually associated with congenital heart disease. Here we report a case of isolated retro-aortic left innominate vein in an adult female.

TrapEase inferior vena cava filter placement: use of the subclavian vein.

Science.gov (United States)

Stone, Patrick A; Aburahma, Ali F; Hass, Stephen M; Hofeldt, Matthew J; Zimmerman, William B; Deel, John T; Deluca, John A

2004-01-01

The purpose of this paper was to evaluate the safety and technical success of TrapEase inferior vena cava filter placement via the subclavian vein. As of yet, no reports in the literature have specifically investigated the use of the subclavian vein as a route for deploying TrapEase vena cava filters. Retrospective chart review was conducted of 135 patients with attempted TrapEase inferior vena cava filter placement over a 2-year period. In a majority of cases, the choice of subclavian vein approach was based primarily on surgeon preference. Other circumstances for subclavian vein deployment included cervical immobilization secondary to trauma, desire for concomitant placement of a subclavian long-term central venous access catheter, and patient body habitus limiting exposure to the internal jugular vein. One hundred and thirty-five filters were placed over this 2-year period. The internal jugular vein approach was used in 56 patients, the femoral vein approach in 39 patients, and the subclavian vein approach in 40 patients. Thirty-nine of the 40 TrapEase filter placements using the subclavian vein were successful. Twenty-six were deployed through the right subclavian vein and 14 through the left subclavian vein. The single failed subclavian deployment was due to the inability to pass the guidewire adequately into the inferior vena cava after successful cannulation of the right subclavian vein. The average deployment time for subclavian vein placement was 26 minutes when TrapEase filter placement was the only procedure performed. No insertional complications were encountered, specifically no pneumothoraces confirmed by chest radiography or fluoroscopy. The subclavian vein provides an alternative site of access for the TrapEase inferior vena cava filter. This route is comparable to other alternative methods evaluated both in average deployment time and complication occurrence. Furthermore, the subclavian vein route is valuable in patients with limited central access

Thermal histories of chondrules in solar nebula shocks, including the effect of molecular line cooling

Science.gov (United States)

Morris, Melissa A.

Chondrules are millimeter-sized, silicate (mostly ferromagnesian) igneous spheres found within chondritic meteorites. They are some of the oldest materials in our Solar System, having formed within a few million years of its birth. Chondrules were melted at high temperature (over 1800 K), while they were free-floating objects in the early solar nebula. Their petrology and chemistry constrain their formation, especially their thermal histories. Chondrules provide some of the most powerful constraints on conditions in the solar nebula. Models in which chondrule precursors melted by passage through solar nebula shocks are very promising, and meet most constraints on chondrule formation in broad brush. However, these models have been lacking in some of the relevant physics. Previous shock models have used incorrect approximations to the input radiation boundary condition, and the opacity of solids has been treated simply. Most important, a proper treatment of cooling due to molecular line emission has not been included. In this thesis, the shock model is significantly improved in order to determine if it remains consistent with observational constraints. The appropriate boundary condition for the input radiation and the proper method for calculation of the opacity of solids are determined, and a complete treatment of molecular line cooling due to water is included. Previous estimates of the effect of line cooling predicted chondrule cooling rates in excess of 10,000 K per hour. However, once molecular line cooling due to water was incorporated into the full shock model, it was found that line cooling has a minimal effect on the thermal histories of gas and chondrules. This behavior is attributed mostly to the thermal buffering of the gas due to hydrogen dissociation and recombination, which tends to keep the gas temperature at approximately 2000 K until the column densities of water become optically thick to line emission. Chondrule cooling rates in the range of 10

Intravitreal triamcinolone acetonide injections in the treatment of retinal vein occlusions.

Science.gov (United States)

Roth, Daniel B; Cukras, Catherine; Radhakrishnan, Ravi; Feuer, William J; Yarian, David L; Green, Stuart N; Wheatley, Harold M; Prenner, Jonathan

2008-01-01

To report the visual acuity response after intravitreal triamcinolone injection in patients with macular edema due to retinal vein occlusions. Retrospective nonrandomized interventional series of 172 consecutive patients with macular edema due to retinal vein occlusions who were treated with intravitreal triamcinolone acetonide injection. Patients underwent Snellen visual acuity testing and ophthalmoscopic examination at baseline and 1, 3, 6, and 12 months after intravitreal triamcinolone acetonide injection. All subtypes of retinal vein occlusions showed significant improvements in mean visual acuity 1 month after injection. This improvement in visual acuity was maintained over the 12-month period for all but the central retinal vein occlusion group. Seventy-one (41.3%) of the 172 patients received more than one intravitreal triamcinolone injection for unresolved or recurrent macular edema. This study demonstrates a benefit associated with intravitreal triamcinolone acetonide injection for retinal vein occlusions that was maintained by patients with branch retinal vein occlusions and hemiretinal vein occlusions over a 12-month period. Visual acuity improvement was not maintained in patients with central retinal vein occlusions with this course of treatment.

Fluid inclusion and stable isotopes studies of epithermal gold-bearing veins in the SE Afar Rift (Djibouti)

Science.gov (United States)

Moussa, N.; Boiron, M. C.; Grassineau, N.; Fouquet, Y.; Le Gall, B.; Mohamed, J.

2015-12-01

The Afar rift results from the interaction of a number of actively-propagating tectono-magmatic axes. Recent field investigations in the SE Afar rift have emphasized the importance of hydrothermal system in rift-related volcanic complexes. Mineralization occur as gold-silver bearing veins and are associated with felsic volcanism. Late carbonate veins barren of sulfides and gold are common. The morphologies and textures of quartz show crustiform colloform banding, massive and breccias. Microthermometric measurements were made on quartz-hosted two phases (liquid + vapor) inclusions; mean homogenization temperature range from 150°C to 340°C and ice-melting temperatures range from -0.2° to 1.6°C indicating that inclusion solutions are dilute and contain 0.35 to 2.7 equivalent wt. % NaCl. Furthermore, δ18O and δ13C values from calcite range from 3.7 to 26.6 ‰ and -7.5 to 0.3‰, respectively. The presence of platy calcite and adularia indicate that boiling condition existed. This study shows that precious-metal deposition mainly occurred from hydrothermal fluids at 200°C at around 300 and 450 m below the present-day surface in a typical low-sulphidation epithermal environment.

Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Melting Efficiency Improvement

Energy Technology Data Exchange (ETDEWEB)

Principal Investigator Kent Peaslee; Co-PI’s: Von Richards, Jeffrey Smith

2012-07-31

Steel foundries melt recycled scrap in electric furnaces and typically consume 35-100% excess energy from the theoretical energy requirement required to pour metal castings. This excess melting energy is multiplied by yield losses during casting and finishing operations resulting in the embodied energy in a cast product typically being three to six times the theoretical energy requirement. The purpose of this research project was to study steel foundry melting operations to understand energy use and requirements for casting operations, define variations in energy consumption, determine technologies and practices that are successful in reducing melting energy and develop new melting techniques and tools to improve the energy efficiency of melting in steel foundry operations.

Robust finger vein ROI localization based on flexible segmentation.

Science.gov (United States)

Lu, Yu; Xie, Shan Juan; Yoon, Sook; Yang, Jucheng; Park, Dong Sun

2013-10-24

Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI) definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system.

Robust Finger Vein ROI Localization Based on Flexible Segmentation

Directory of Open Access Journals (Sweden)

Dong Sun Park

2013-10-01

Full Text Available Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system.

Robust Finger Vein ROI Localization Based on Flexible Segmentation

Science.gov (United States)

Lu, Yu; Xie, Shan Juan; Yoon, Sook; Yang, Jucheng; Park, Dong Sun

2013-01-01

Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI) definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system. PMID:24284769

Slow shocks and their transition to fast shocks in the inner solar wind

International Nuclear Information System (INIS)

Wang, Y.C.

1987-01-01

The jump conditions of MHD shocks may be directly calculated as functions of three upstream conditions: the shock Alfven number based on the normal component of the relative shock speed, the shock angle, and the plasma β value. The shock Alfven number is less than 1 for a slow shock and greater than 1 for a fast shock. A traveling, forward shock can be a slow shock in coronal space, where the Alfven speed is of the order of 1000 km/s. The surface of a forward slow shock has a bow-shaped geometry with its nose facing toward the sun. The decrease in the Alfven speed at increasing heliocentric distance causes the shock Alfven number of a forward slow shock to become greater than 1, and the shock eventually evolves from a slow shock into a fast shock. During the transition the shock system consists of a slow shock, a fast shock, and a rotational discontinuity. They intersect along a closed transition line. As the system moves outward from the sun, the area enclosed by the transition line expands, the fast shock grows stronger, and the slow shock becomes weaker. Eventually, the slow shock diminishes, and the entire shock system evolves into a forward fast shock. copyrightAmerican Geophysical Union 1987

MELT-IIIB: an updated version of the melt code

International Nuclear Information System (INIS)

Tabb, K.K.; Lewis, C.H.; O'Dell, L.D.; Padilla, A. Jr.; Smith, D.E.; Wilburn, N.P.

1979-04-01

The MELT series is a reactor modeling code designed to investigate a wide variety of hypothetical accident conditions, particularly the transient overpower sequence. MELT-IIIB is the latest in the series

Study of particles clouds ejected under shock: the contributions of Photonic Doppler Velocimetry

International Nuclear Information System (INIS)

Prudhomme, Gabriel

2014-01-01

A metal plate subjected to a shock (tin, 10 GPa) undergoes a variety of damages such as spalling or the ejection of a cloud of particles. Two main mechanisms govern the formation of this cloud: the micro-jetting and the melting under shock. Photonic Doppler Velocimetry (PDV, a.k.a. LDV or het-V) is a multi-velocity time-resolved diagnostic. Developed from 2000's, the all-fibered conception makes its integration easy into shock experiments. The purpose of the thesis is to describe the contributions of PDV systems for high-velocity (several km/s) particle-cloud characterization, including micro-jetting cloud. This document presents a state of the art of shock generators, diagnostics and (numerical and experimental) studies involved in metallic micro-machined jetting. An extensive study of a PDV system is proposed. It leads to the definition of time-velocity spectrogram, evaluated in units of collected power, and a detection capability limit. Thanks to photon diffusion models, a threshold in the diameter of the measured particle is estimated. A PDV spectrogram simulation program is shown within the framework of particle clouds. Finally, several experimental campaigns are exposed. They emphasize the remarkable capacities of the system; results are compared to simulations. Diameter distributions are inferred using slowing down in air or in other gazes. Some radiometric analyses are also performed. (author) [fr

Contact-free palm-vein recognition based on local invariant features.

Directory of Open Access Journals (Sweden)

Wenxiong Kang

Full Text Available Contact-free palm-vein recognition is one of the most challenging and promising areas in hand biometrics. In view of the existing problems in contact-free palm-vein imaging, including projection transformation, uneven illumination and difficulty in extracting exact ROIs, this paper presents a novel recognition approach for contact-free palm-vein recognition that performs feature extraction and matching on all vein textures distributed over the palm surface, including finger veins and palm veins, to minimize the loss of feature information. First, a hierarchical enhancement algorithm, which combines a DOG filter and histogram equalization, is adopted to alleviate uneven illumination and to highlight vein textures. Second, RootSIFT, a more stable local invariant feature extraction method in comparison to SIFT, is adopted to overcome the projection transformation in contact-free mode. Subsequently, a novel hierarchical mismatching removal algorithm based on neighborhood searching and LBP histograms is adopted to improve the accuracy of feature matching. Finally, we rigorously evaluated the proposed approach using two different databases and obtained 0.996% and 3.112% Equal Error Rates (EERs, respectively, which demonstrate the effectiveness of the proposed approach.

Contact-free palm-vein recognition based on local invariant features.

Science.gov (United States)

Kang, Wenxiong; Liu, Yang; Wu, Qiuxia; Yue, Xishun

2014-01-01

Contact-free palm-vein recognition is one of the most challenging and promising areas in hand biometrics. In view of the existing problems in contact-free palm-vein imaging, including projection transformation, uneven illumination and difficulty in extracting exact ROIs, this paper presents a novel recognition approach for contact-free palm-vein recognition that performs feature extraction and matching on all vein textures distributed over the palm surface, including finger veins and palm veins, to minimize the loss of feature information. First, a hierarchical enhancement algorithm, which combines a DOG filter and histogram equalization, is adopted to alleviate uneven illumination and to highlight vein textures. Second, RootSIFT, a more stable local invariant feature extraction method in comparison to SIFT, is adopted to overcome the projection transformation in contact-free mode. Subsequently, a novel hierarchical mismatching removal algorithm based on neighborhood searching and LBP histograms is adopted to improve the accuracy of feature matching. Finally, we rigorously evaluated the proposed approach using two different databases and obtained 0.996% and 3.112% Equal Error Rates (EERs), respectively, which demonstrate the effectiveness of the proposed approach.

Budd-Chiari and inferior caval vein syndromes due to membranous obstruction of the liver veins. Successful treatment with angioplasty and transcaval TIPS

DEFF Research Database (Denmark)

Holland-Fischer, Peter

2004-01-01

The case is presented of a 25-year-old Caucasian patient with Budd-Chiari syndrome due to membranous obstruction of the liver veins and inferior caval vein syndrome as a result of secondary hyperplasia of the caudate lobe of the liver, obstructing the caval vein. Diagnosis was established...... that angioplasty and TIPS are safe and efficient procedures to reduce liver engorgement and complications of portal hypertension in selected patients with Budd-Chiari syndrome....

Retinal vein occlusion: pathophysiology and treatment options

OpenAIRE

Karia, Niral

2010-01-01

Niral KariaDepartment of Ophthalmology, Southend Hospital, Prittlewell Chase, Westcliff on Sea, Essex, United KingdomAbstract: This paper reviews the current thinking about retinal vein occlusion. It gives an overview of its pathophysiology and discusses the evidence behind the various established and emerging treatment paradigms.Keywords: central, hemispheric, branch, retinal vein occlusion, visual loss

Percutaneous closure of patent ductus arteriosus in interrupted inferior caval vein through femoral vein approach

Directory of Open Access Journals (Sweden)

Endale Tefera

2014-01-01

Full Text Available Percutaneous closure of the patent arterial duct in patients with interrupted inferior caval vein poses a technical challenge. A 12-year-old girl with a patent ductus arteriosus (PDA and interrupted inferior caval vein is described in this report. The diagnosis of interrupted inferior caval vein and azygos continuation was made in the catheterization laboratory. A catheter was advanced and snared in the descending aorta. An exchange wire was advanced through the catheter and snared in the descending aorta. Then, an Amplatzer TorqVue 2 delivery sheath was advanced over the wire from the venous side and again snared in the descending aorta. An Amplatzer duct occluder (ADO size 8/6 was advanced through the sheath while still holding the sheath with a snare. The device was opened. The sheath was then unsnared once the aortic disc was completely out. The sheath and the device were pulled back into the duct and the device was successfully implanted. The device was then released and it attained a stable position. An aortic angiogram was performed which showed complete occlusion.

Percutaneous closure of patent ductus arteriosus in interrupted inferior caval vein through femoral vein approach

International Nuclear Information System (INIS)

Tefera, Endale; Bermudez-Cañete, Ramon

2014-01-01

Percutaneous closure of the patent arterial duct in patients with interrupted inferior caval vein poses a technical challenge. A 12-year-old girl with a patent ductus arteriosus (PDA) and interrupted inferior caval vein is described in this report. The diagnosis of interrupted inferior caval vein and azygos continuation was made in the catheterization laboratory. A catheter was advanced and snared in the descending aorta. An exchange wire was advanced through the catheter and snared in the descending aorta. Then, an Amplatzer TorqVue 2 delivery sheath was advanced over the wire from the venous side and again snared in the descending aorta. An Amplatzer duct occluder (ADO) size 8/6 was advanced through the sheath while still holding the sheath with a snare. The device was opened. The sheath was then unsnared once the aortic disc was completely out. The sheath and the device were pulled back into the duct and the device was successfully implanted. The device was then released and it attained a stable position. An aortic angiogram was performed which showed complete occlusion

[Intraosseous veins of the maxilla in the newborn].

Science.gov (United States)

Bogdanov, R A

1975-12-01

The intraosseous veins of the maxilla in newborns grow larger with enlargement of the bone and become disposed in three mutually perpendicular planes. The venous plexus of the alveolar process is large. V. v. vallares are thin and interlace forming a network. The veins of interdental septum are well pronounced. The thick venous network of the periosteum and the mucous membrane of the nasal surface of the palatine process includes the vessels transversal and longitudinal to the nasal septum. The venous loops of the incisor part are of triangular, pentagonal and polygonal shape. The veins of the palatine process are connected with 3-4 large vessels falling into the vessels of the tear duct. The transversal and oblique veins of the oral surface of the palatine process are connected with large vessels disposed in parallel to the medial structure of the hard palate. The venous network of the incisor part of the bone is restricted by densified small arc-shaped plexuses. Two-three largest veins lie sagittally and, connected by arc-shaped anastomoses, are tributaries of the vessels of the palate bone, soft palate and pharynx.

Anatomical variation of thyroid veins on contrast-enhanced multi-detector row computed tomography

Energy Technology Data Exchange (ETDEWEB)

Tomita, Hayato, E-mail: m04149@yahoo.co.jp [Department of Radiology, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashicho, Asahi-ku, Yokohama, Kanagawa 241-0811 (Japan); Yamada, Takayuki; Murakami, Kenji; Hashimoto, Kazuki; Tazawa, Yoko; Kumano, Reiko [Department of Radiology, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashicho, Asahi-ku, Yokohama, Kanagawa 241-0811 (Japan); Nakajima, Yasuo [Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511 (Japan)

2015-05-15

Highlights: • This is the first study to demonstrate the anatomy of thyroid veins on contrasted-enhanced MDCT. • Identifying the thyroid vein on MDCT prior to selective venous sampling of parathyroid hormone provides clinical information to interventional radiologist. • Detecting especially the inferior thyroid veins with individual variability in numbers, locations, and lengths may have an effect on SVS for HPT and decrease the difficulty and time of the procedure. - Abstract: Objective: The objective of this study was to clarify the anatomical variation of thyroid veins into the systemic vein using contrast-enhanced multi-detector row computed tomography (MDCT). Design and methods: : The subjects were 80 patients (34 males and 46 females; mean age, 50.1 years; age range, 15–92 years) with neck diseases who underwent MDCT. The number and location of inflow points of the thyroid veins into the systemic vein, and the length from the junction of bilateral brachiocephalic veins to the orifice of inferior thyroid vein were investigated by reviewing the axial and coronal images. Results: All superior thyroid veins were detected. Right and left middle thyroid veins were identified in 39 and 29 patients, respectively. Right inferior thyroid veins, left inferior thyroid veins, and common trunks were detected in 43, 46, and 39 patients, respectively; in five patients, two left thyroid veins were identified. All left inferior thyroid veins and 34 common trunks flowed into the innominate vein, while right ones had some variations in inflow sites. Mean lengths were 3.01 ± 1.30 cm (range, 0.5–6.19) and 2.04 ± 0.91 cm (0.5–4.4) in the left inferior thyroid vein and common trunk, and 1.96 ± 1.05 cm (0.81–4.8) and 1.65 ± 0.69 cm (0.63–2.94) in the right one flowing into the right internal jugular vein and the innominate vein, respectively. Conclusions: The numbers and orifices of thyroid veins were identified at high rates on contrast-enhanced MDCT. This

Cloud screening and melt water detection over melting sea ice using AATSR/SLSTR

Science.gov (United States)

Istomina, Larysa; Heygster, Georg

2014-05-01

With the onset of melt in the Arctic Ocean, the fraction of melt water on sea ice, the melt pond fraction, increases. The consequences are: the reduced albedo of sea ice, increased transmittance of sea ice and affected heat balance of the system with more heat passing through the ice into the ocean, which facilitates further melting. The onset of melt, duration of melt season and melt pond fraction are good indicators of the climate state of the Arctic and its change. In the absence of reliable sea ice thickness retrievals in summer, melt pond fraction retrieval from satellite is in demand as input for GCM as an indicator of melt state of the sea ice. The retrieval of melt pond fraction with a moderate resolution radiometer as AATSR is, however, a non-trivial task due to a variety of subpixel surface types with very different optical properties, which give non-unique combinations if mixed. In this work this has been solved by employing additional information on the surface and air temperature of the pixel. In the current work, a concept of melt pond detection on sea ice is presented. The basis of the retrieval is the sensitivity of AATSR reflectance channels 550nm and 860nm to the amount of melt water on sea ice. The retrieval features extensive usage of a database of in situ surface albedo spectra. A tree of decisions is employed to select the feasible family of in situ spectra for the retrieval, depending on the melt stage of the surface. Reanalysis air temperature at the surface and brightness temperature measured by the satellite sensor are analyzed in order to evaluate the melting status of the surface. Case studies for FYI and MYI show plausible retrieved melt pond fractions, characteristic for both of the ice types. The developed retrieval can be used to process the historical AATSR (2002-2012) dataset, as well as for the SLSTR sensor onboard the future Sentinel-3 mission (scheduled for launch in 2015), to keep the continuity and obtain longer time sequence

Multidetector CT venography and contrast-enhanced MR venography of the inferior mesenteric vein in paediatric extrahepatic portal vein obstruction

International Nuclear Information System (INIS)

Chennur, Vikash SrinivasaiahSetty; Sharma, Raju; Gamanagatti, Shivanand; Gupta, Arun Kumar; Bhatnagar, Veereshwar; Vishnubhatla, Sreenivas

2011-01-01

Extrahepatic portal vein obstruction (EHPVO) is a common cause of paediatric portal hypertension and the only permanent treatment is shunt surgery. The inferior mesenteric vein (IMV) is a portal venous channel that can be used for the shunt when the splenic vein/superior mesenteric vein is thrombosed or when a lienorenal shunt is not possible. To compare MDCT venography (MDCTV) and contrast-enhanced MR venography (CEMRV) for visualisation of the IMV in children with EHPVO. This was a prospective study of 26 children (4-12 years, median 10 years) who underwent MDCTV and CEMRV. The IMV visualisation was graded using 4- and 2-point scales and the difference in visualisation was assessed by calculating the exact significance probability (P). The IMV was visualised in all children on MDCTV and 25/26 children on CEMRV (96%). The images were diagnostic in 23/26 children (88%) on MDCTV and in 18/26 (69%) children on CEMRV (P = 0.063). MDCTV and CEMRV are comparable for IMV visualisation with a tendency toward MDCTV being superior. (orig.)

Multidetector CT venography and contrast-enhanced MR venography of the inferior mesenteric vein in paediatric extrahepatic portal vein obstruction

Energy Technology Data Exchange (ETDEWEB)

Chennur, Vikash SrinivasaiahSetty; Sharma, Raju; Gamanagatti, Shivanand; Gupta, Arun Kumar [All India Institute of Medical Sciences (AIIMS), Department of Radiology, New Delhi (India); Bhatnagar, Veereshwar [AIIMS, Department of Paediatric Surgery, New Delhi (India); Vishnubhatla, Sreenivas [AIIMS, Department of Biostatistics, New Delhi (India)

2011-03-15

Extrahepatic portal vein obstruction (EHPVO) is a common cause of paediatric portal hypertension and the only permanent treatment is shunt surgery. The inferior mesenteric vein (IMV) is a portal venous channel that can be used for the shunt when the splenic vein/superior mesenteric vein is thrombosed or when a lienorenal shunt is not possible. To compare MDCT venography (MDCTV) and contrast-enhanced MR venography (CEMRV) for visualisation of the IMV in children with EHPVO. This was a prospective study of 26 children (4-12 years, median 10 years) who underwent MDCTV and CEMRV. The IMV visualisation was graded using 4- and 2-point scales and the difference in visualisation was assessed by calculating the exact significance probability (P). The IMV was visualised in all children on MDCTV and 25/26 children on CEMRV (96%). The images were diagnostic in 23/26 children (88%) on MDCTV and in 18/26 (69%) children on CEMRV (P = 0.063). MDCTV and CEMRV are comparable for IMV visualisation with a tendency toward MDCTV being superior. (orig.)

Primary leiomyosarcoma of the innominate vein.

Science.gov (United States)

Illuminati, Giulio; Miraldi, Fabio; Mazzesi, Giuseppe; D'urso, Antonio; Ceccanei, Gianluca; Bezzi, Marcello

2007-01-01

Primary venous leiomyosarcoma is rare. We report the case of a primary leiomyosarcoma of the left innominate vein, with neoplastic thrombus extending into the left jugular and subclavian veins. The tumor was curatively resected en bloc with anterior mediastinal and laterocervical lymphatics, through a median sternotomy prolonged into left cervicotomy. Primary venous sarcomas may be associated with prolonged survival in individual cases, with curative resection recommended as the standard treatment, in the absence of distant spread.

Right top pulmonary vein: Evaluation with 64 section multidetector computed tomography

International Nuclear Information System (INIS)

Arslan, Gokhan; Dincer, Elvan; Kabaalioglu, Adnan; Ozkaynak, Can

2008-01-01

Purpose: To evaluate the incidence and anatomic features of the rare variant of the pulmonary veins named 'right top pulmonary vein' as depicted with 64 section multidetector computed tomography (MDCT). Materials and methods: MDCT of 610 patients obtained over 12 months period for diagnosis of suspected thoracic or cardiac pathology were routinely reviewed in transverse and 3D images. The frequency of right top pulmonary vein (RTPV) was determined and anatomic features were also documented. Results: Right top pulmonary vein (RTPV) is a supernumerary vein arising from the roof of the right part of the left atrium separately from the orifice of the right superior pulmonary vein. It crosses behind the intermediate bronchus and drains mainly posterior segment of the right upper lobe but also receives few subsegmental branches of superior segment of the right lower lobe. It was detected in 2.2% of patients (14/610). The mean diameter of RTPV was 5.1 mm. Conclusion: The RTPV is a rare venous drainage variation of pulmonary veins. It is important to be aware of this anatomic pattern for avoiding misinterpretation of pulmonary venographic findings, inadvertent ablation of pulmonary vein and perioperative bleeding during video assisted thorocoscopic lobectomy

Thermal shock behavior of W-ZrC/Sc2O3 composites under two different transient events by electron and laser irradiation

Science.gov (United States)

Chen, Hong-Yu; Luo, Lai-Ma; Zan, Xiang; Xu, Qiu; Tokunaga, Kazutoshi; Liu, Jia-Qin; Zhu, Xiao-Yong; Cheng, Ji-Gui; Wu, Yu-Cheng

2018-02-01

The transient thermal shock behaviors of W-ZrC/Sc2O3 composites with different ZrC contents were evaluated using transient thermal shock test by electron and laser beams. The effects of different ZrC doping contents on the surface morphology and thermal shock resistance of W-ZrC/Sc2O3 composites were then investigated. Similarity and difference between effects of electron and laser beam transient heat loading were also discussed in this study. Repeated heat loading resulted in thermal fatigue of the irradiated W-ZrC/Sc2O3 samples by thermal stress, leading to the rough surface morphologies with cracks. After different transient thermal tests, significant surface roughening, cracks, surface melting, and droplet ejection occurred. W-2vol.%Sc2O3 sample has superior thermal properties and greater resistance to surface modifications under transient thermal shock, and with the increasing ZrC content in W alloys, thermal shock resistance of W-Zr/Sc2O3 sample tends to be unsatisfied.

Regional heterogeneity of endothelial cells in the porcine vortex vein system.

Science.gov (United States)

Tan, Priscilla Ern Zhi; Yu, Paula K; Cringle, Stephen J; Morgan, William H; Yu, Dao-Yi

2013-09-01

The aim of this study was to investigate whether region-dependent endothelial heterogeneity is present within the porcine vortex vein system. The superior temporal vortex vein in young adult pig eyes were dissected out and cannulated. The intact vortex vein system down to the choroidal veins was then perfused with labels for f-actin and nucleic acid. The endothelial cells within the choroidal veins, pre-ampulla, anterior portion of the ampulla, mid-ampulla, posterior portion of the ampulla, post-ampulla, intra-scleral canal and the extra-ocular vortex vein regions were studied in detail using a confocal microscopy technique. The endothelial cell and nuclei length, width, area and perimeter were measured and compared between the different regions. Significant regional differences in the endothelial cell and nuclei length, width, area and perimeter were observed throughout the porcine vortex vein system. Most notably, very narrow and elongated endothelia were found in the post-ampulla region. A lack of smooth muscle cells was noted in the ampulla region compared to other regions. Heterogeneity in endothelial cell morphology is present throughout the porcine vortex vein system and there is a lack of smooth muscle cells in the ampulla region. This likely reflects the highly varied haemodynamic conditions and potential blood flow control mechanisms in different regions of the vortex vein system. Copyright © 2013 Elsevier Inc. All rights reserved.

Management Strategy for Patients With Chronic Subclavian Vein Thrombosis.

Science.gov (United States)

Keir, Graham; Marshall, M Blair

2017-02-01

We performed a systematic review to determine best practice for the management of patients with chronic or subacute subclavian vein thrombosis. This condition is best managed with surgical excision of the first rib followed by long-term anticoagulation. Interventional techniques aimed at restoring patency are ineffective beyond 2 weeks postthrombosis. Additional therapeutic options should be made based on the severity of symptoms as well as vein status. Patients with milder symptoms are given decompression surgery followed by anticoagulation whereas patients with more severe symptoms are considered for either a jugular vein transposition or saphenous patch based on the vein characteristics. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

MULTIPLE VARIATIONS OF THE SUPERFICIAL JUGULAR VEINS: CASE REPORT AND CLINICAL RELEVANCE

Directory of Open Access Journals (Sweden)

George Paraskevas

2014-01-01

Full Text Available The jugular venous system constitutes the primary venous drainage of the head and neck. It includes a profundus or subfascial venous system, formed by the two internal jugular veins, and a superficial or subcutaneous one, formed by the two anterior and two external jugular veins. We report one case of unilateral anatomical variations of the external and anterior jugular veins. Particularly, on the right side, three external jugular veins co-existed with two anterior jugular veins. Such a combination of venous anomalies is extremely rare. The awareness of the variability of these veins is essential to anesthesiologists and radiologists, since the external jugular vein constitutes a common route for catheterization. Their knowledge is also important to surgeons performing head and neck surgery.

Surgery for acquired cardiovascular disease: antiseptic treatment of contaminated vein grafts.

Science.gov (United States)

Schmidt, F P; Peivandi, A A; Kohnen, W; Jansen, B

2014-04-01

Saphenous vein grafts harvested for use as bypass conduits can be contaminated intraoperatively, e.g. by being inadvertently dropped to the floor of the operating room (OR). This study was performed to investigate microorganisms most likely contaminating vein grafts and to assess the possible efficacy of measures to treat potentially contaminated vein grafts antiseptically for further use. In a first step we determined the microbiological flora of the OR using surface cultures and cultures from intentionally dropped vein grafts. Several antiseptic agents (PVP-iodine 10%, octenidinhydrochloride 0.1%, polyhexanide 1%) were evaluated for their in vitro efficacy to disinfect artificially contaminated vein segments. The most promising antiseptic regimen was tested on veins contaminated in a real OR setting. Finally, we tested for possible alterations in mechanical properties of the veins caused by antiseptic treatment. Coagulase-negative staphylococci where the predominant bacteria recovered from the OR with 59.9%. Antiseptic treatment with a combination of octenidine and PVP-iodine resulted in a higher rate of negative cultures than any single agent. Treatment of 50 saphenous vein grafts contaminated in the OR with the combination regimen resulted in only 3 positive cultural results within 7 days. Mechanical tear-stress testing comparing antiseptically treated vein grafts with controls showed no difference in their resistance to tear stress. Antiseptic treatment of contaminated vein grafts was shown to be effective in a high percentage of cases without altering mechanical properties of grafts and may be an option for the surgeon in case of a contamination.

Toxic shock syndrome

Science.gov (United States)

Staphylococcal toxic shock syndrome; Toxic shock-like syndrome; TSLS ... Toxic shock syndrome is caused by a toxin produced by some types of staphylococcus bacteria. A similar problem, called toxic shock- ...

Clinicopathological comparisons of open vein harvesting and endoscopic vein harvesting in coronary artery bypass grafting patients in Mashhad.

Science.gov (United States)

Amouzeshi, Ahmad; Teshnisi, Mohamad Abbassi; Zirak, Nahid; Shamloo, Alireza Sepehri; Hoseinikhah, Hamid; Alizadeh, Behzad; Moeinipour, Aliasghar

2016-01-01

Harvesting of the greater saphenous vein is almost an inevitable part of coronary artery bypass grafting (CABG) operations, and it is done by two main techniques, i.e., conventional or open vein harvesting (OVH) and the minimally-invasive endoscopic vein harvesting (EVH). This study aimed to compare these two techniques in off-pump CABG procedures with respect to clinical and pathological outcomes. This cohort study was conducted on CABG candidates during a one-year period from October 2013 through September 2014 in the Department of Cardiac Surgery at Mashhad University of Medical Sciences. Eighty-seven patients voluntarily underwent EVH, and another 86 patients matched for age, gender, and other cardiovascular risk factors were selected for OVH. They were followed up for six weeks, and the main outcome measures were infections of the wound, pain, duration of hospital stay, and the costs of hospitalization. Paired sample t-test, independent t-test, or their non-parametric equivalents and the chi-squared test were used by SPSS version 17.0 for data analysis. The mean duration of time for vein harvesting was shorter in the EVH group (p < 0.001), and the pain score was lower (p = 0.04). No infections occurred at the site of the wound. The length of hospital stay was not significantly different for the two groups (OVH versus EVH: 8.5 ± 3.3 versus 8.4 ± 3.2 days; p-value: 0.08). Hospitalization costs were significantly higher in the EVH group (OVH versus EVH: 5.8 ± 4.7 versus 7.3 ± 2.0 million Tomman; p-value: 0.008), yet no difference was diagnosed with respect to endothelial damage in the vein grafts harvested by the EVH and OVH techniques. EVH is considered as a minimally invasive and safe vein harvesting technique in our Center, and it can reduce the harvesting time and post-operative pain. In addition, its efficiency was similar to that of OVH.

Leiomyosarcoma of inferior vena cava involving bilateral renal veins: Surgical challenges and reconstruction with upfront saphenous vein interposition graft for left renal vein outflow

Directory of Open Access Journals (Sweden)

Rishi Nayyar

2010-01-01

Full Text Available Leiomyosarcoma of inferior vena cava (IVC involving bilateral renal veins presents a surgical challenge. Herein, we report the successful management of two such cases using restoration of left renal venous outflow by saphenous vein interposition graft as first step of surgery. Then radical resection of tumor and right kidney was done. IVC was lastly reconstructed using Gore-Tex graft. This report highlights the surgical challenges to ensure radical resection. Furthermore, the importance of restoring left renal outflow in presence of concomitant right nephrectomy is discussed. Both the patients were disease free at six months with no loss of left renal glomerular filtration rate.

Two-temperature hydrodynamics of laser-generated ultrashort shock waves in elasto-plastic solids

International Nuclear Information System (INIS)

Ilnitsky, Denis K; Migdal, Kirill P; Khokhlov, Viktor A; Inogamov, Nail A; Petrov, Yurii V; Anisimov, Sergey I; Zhakhovsky, Vasily V; Khishchenko, Konstantin V

2014-01-01

Shock-wave generation by ultrashort laser pulses opens new doors for study of hidden processes in materials happened at an atomic-scale spatiotemporal scales. The poorly explored mechanism of shock generation is started from a short-living two-temperature (2T) state of solid in a thin surface layer where laser energy is deposited. Such 2T state represents a highly non-equilibrium warm dense matter having cold ions and hot electrons with temperatures of 1-2 orders of magnitude higher than the melting point. Here for the first time we present results obtained by our new hybrid hydrodynamics code combining detailed description of 2T states with a model of elasticity together with a wide-range equation of state of solid. New hydro-code has higher accuracy in the 2T stage than molecular dynamics method, because it includes electron related phenomena including thermal conduction, electron-ion collisions and energy transfer, and electron pressure. From the other hand the new code significantly improves our previous version of 2T hydrodynamics model, because now it is capable of reproducing the elastic compression waves, which may have an imprint of supersonic melting like as in MD simulations. With help of the new code we have solved a difficult problem of thermal and dynamic coupling of a molten layer with an uniaxially compressed elastic solid. This approach allows us to describe the recent femtosecond laser experiments.

Beta irradiation inhibits neo-intimal formation in vein grafts

International Nuclear Information System (INIS)

Lang Xiaoou; Ji Shenquan; Zeng Ke; Li Jun; Liu Bingbing; Ma Wenfeng; Zhang Qiang

2002-01-01

Objective: The study was to evaluate the effect of beta irradiation on intimal proliferation response in vein grafts. Methods: An autogenous vein graft model was established in 40 rats by transplanting internal branch of jugular vein to carotid artery by end-to-end anastomosis. The vein was irradiated by 32 P before anastomosis. Four dose schedules were studied: (1) control graft (nonirradiated); (2) irradiated with 8 Gy; (3) 18 Gy; and (4) 36 Gy. The grafted veins were harvested at 2 weeks after the operation. IH (intimal hyperplasia) and SMC (smooth muscle cell) proliferation were histologically and immuno-histochemically observed and analyzed by a computer digitalising system. Results: In 18 Gy and 36 Gy-irradiated grafts compared with the control, there was a significant decrease in the average intimal thickness (P 0.05). Immunohistochemical analysis of PCNA indicated decrease of positive cells in both 18 Gy and 36 Gy groups compared with 8 Gy and the control group (P 0.05) groups, and there was also no significant difference between 8 Gy and the control group (P > 0.05). Conclusion: These preliminary results demonstrate that proper dose of beta irradiation in vein graft inhibits smooth muscle cells proliferation and neo-intimal hyperplasia in rat

Effects of high shock pressures and pore morphology on hot spot mechanisms in HMX

Science.gov (United States)

Springer, H. K.; Tarver, C. M.; Bastea, S.

2017-01-01

The shock initiation and detonation behavior of heterogeneous solid explosives is governed by its microstructure and reactive properties. New additive manufacturing techniques offer unprecedented control of explosive microstructures previously impossible, enabling us to develop novel explosives with tailored shock sensitivity and detonation properties. Since microstructure-performance relationships are not well established for explosives, there is little material design guidance for these manufacturing techniques. In this study, we explore the effects of high shock pressures (15-38 GPa) with long shock durations and different pore morphologies on hot spot mechanisms in HMX. HMX is chosen as the model material because we have experimental data on many of the chemical-thermal-mechanical properties required for pore collapse simulations. Our simulations are performed using the multi-physics arbitrary Lagrangian Eulerian finite element hydrocode, ALE3D, with Cheetah-based models for the unreacted and the product equation-of-states. We use a temperature-dependent specific heat with the unreacted equation-of-state and a temperature-dependent viscosity model to ensure accurate shock temperatures for subsequent chemistry. The Lindemann Law model is used for shock melting in HMX. In contrast to previous pore collapse studies at lower shock pressures (≤10 GPa) in HMX and shorter post-collapse burning times, our calculations show that shock melting occurs above 15 GPa due to higher bulk heating and a prominent elongated ("jet-like") hot spot region forms at later times. The combination of the elongated, post-collapse hot spot region and the higher bulk heating with increasing pressure dramatically increases the growth rate of reaction. Our calculations show that the reaction rate, dF/dt, increases with increasing shock pressure. We decompose the reaction rate into ignition ((dF/dt)ig) and growth ((dF/dt)gr) phases to better analyze our results. We define the ignition phase

Geometric Analysis of Vein Fracture Networks From the Awibengkok Core, Indonesia

Science.gov (United States)

Khatwa, A.; Bruhn, R. L.; Brown, S. R.

2003-12-01

Fracture network systems within rocks are important features for the transportation and remediation of hazardous waste, oil and gas production, geothermal energy extraction and the formation of vein fillings and ore deposits. A variety of methods, including computational and laboratory modeling have been employed to further understand the dynamic nature of fractures and fracture systems (e.g. Ebel and Brown, this session). To substantiate these studies, it is also necessary to analyze the characteristics and morphology of naturally occurring vein systems. The Awibengkok core from a geothermal system in West Java, Indonesia provided an excellent opportunity to study geometric and petrologic characteristics of vein systems in volcanic rock. Vein minerals included chlorite, calcite, quartz, zeolites and sulphides. To obtain geometric data on the veins, we employed a neural net image processing technique to analyze high-resolution digital photography of the veins. We trained a neural net processor to map the extent of the vein using RGB pixel training classes. The resulting classification image was then converted to a binary image file and processed through a MatLab program that we designed to calculate vein geometric statistics, including aperture and roughness. We also performed detailed petrographic and microscopic geometric analysis on the veins to determine the history of mineralization and fracturing. We found that multi-phase mineralization due to chemical dissolution and re-precipitation as well as mechanical fracturing was a common feature in many of the veins and that it had a significant role for interpreting vein tortuosity and history of permeability. We used our micro- and macro-scale observations to construct four hypothetical permeability models that compliment the numerical and laboratory modeled data reported by Ebel and Brown. In each model, permeability changes, and in most cases fluctuates, differently over time as the tortuosity and aperture of

Preventing Deep Vein Thrombosis

Science.gov (United States)

... Physicians Contact Us My ACOG ACOG Departments Donate Shop Career Connection Home Clinical Guidance & Publications Practice Management ... skin. A clot also can form if blood flow is too slow the lining of a vein ...

Finger Vein Recognition Based on Local Directional Code

Science.gov (United States)

Meng, Xianjing; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

2012-01-01

Finger vein patterns are considered as one of the most promising biometric authentication methods for its security and convenience. Most of the current available finger vein recognition methods utilize features from a segmented blood vessel network. As an improperly segmented network may degrade the recognition accuracy, binary pattern based methods are proposed, such as Local Binary Pattern (LBP), Local Derivative Pattern (LDP) and Local Line Binary Pattern (LLBP). However, the rich directional information hidden in the finger vein pattern has not been fully exploited by the existing local patterns. Inspired by the Webber Local Descriptor (WLD), this paper represents a new direction based local descriptor called Local Directional Code (LDC) and applies it to finger vein recognition. In LDC, the local gradient orientation information is coded as an octonary decimal number. Experimental results show that the proposed method using LDC achieves better performance than methods using LLBP. PMID:23202194

Finger Vein Recognition Based on Local Directional Code

Directory of Open Access Journals (Sweden)

Rongyang Xiao

2012-11-01

Full Text Available Finger vein patterns are considered as one of the most promising biometric authentication methods for its security and convenience. Most of the current available finger vein recognition methods utilize features from a segmented blood vessel network. As an improperly segmented network may degrade the recognition accuracy, binary pattern based methods are proposed, such as Local Binary Pattern (LBP, Local Derivative Pattern (LDP and Local Line Binary Pattern (LLBP. However, the rich directional information hidden in the finger vein pattern has not been fully exploited by the existing local patterns. Inspired by the Webber Local Descriptor (WLD, this paper represents a new direction based local descriptor called Local Directional Code (LDC and applies it to finger vein recognition. In LDC, the local gradient orientation information is coded as an octonary decimal number. Experimental results show that the proposed method using LDC achieves better performance than methods using LLBP.

Palm Vein Verification Using Multiple Features and Locality Preserving Projections

Directory of Open Access Journals (Sweden)

Ali Mohsin Al-juboori

2014-01-01

Full Text Available Biometrics is defined as identifying people by their physiological characteristic, such as iris pattern, fingerprint, and face, or by some aspects of their behavior, such as voice, signature, and gesture. Considerable attention has been drawn on these issues during the last several decades. And many biometric systems for commercial applications have been successfully developed. Recently, the vein pattern biometric becomes increasingly attractive for its uniqueness, stability, and noninvasiveness. A vein pattern is the physical distribution structure of the blood vessels underneath a person’s skin. The palm vein pattern is very ganglion and it shows a huge number of vessels. The attitude of the palm vein vessels stays in the same location for the whole life and its pattern is definitely unique. In our work, the matching filter method is proposed for the palm vein image enhancement. New palm vein features extraction methods, global feature extracted based on wavelet coefficients and locality preserving projections (WLPP, and local feature based on local binary pattern variance and locality preserving projections (LBPV_LPP have been proposed. Finally, the nearest neighbour matching method has been proposed that verified the test palm vein images. The experimental result shows that the EER to the proposed method is 0.1378%.

Portal vein branching order helps in the recognition of anomalous right-sided round ligament: common features and variations in portal vein anatomy.

Science.gov (United States)

Yamashita, Rikiya; Yamaoka, Toshihide; Nishitai, Ryuta; Isoda, Hiroyoshi; Taura, Kojiro; Arizono, Shigeki; Furuta, Akihiro; Ohno, Tsuyoshi; Ono, Ayako; Togashi, Kaori

2017-07-01

This study aimed to evaluate the common features and variations of portal vein anatomy in right-sided round ligament (RSRL), which can help propose a method to detect and diagnose this anomaly. In this retrospective study of 14 patients with RSRL, the branching order of the portal tree was analyzed, with special focus on the relationship between the dorsal branch of the right anterior segmental portal vein (P A-D ) and the lateral segmental portal vein (P LL ), to determine the common features. The configuration of the portal vein from the main portal trunk to the right umbilical portion (RUP), the inclination of the RUP, and the number and thickness of the ramifications branching from the right anterior segmental portal vein (P A ) were evaluated for variations. In all subjects, the diverging point of the P A-D was constantly distal to that of the P LL . The portal vein configuration was I- and Z-shaped in nine and five subjects, respectively. The RUP was tilted to the right in all subjects. In Z-shaped subjects, the portal trunk between the branching point of the right posterior segmental portal vein and that of the P LL was tilted to the left in one subject and was almost parallel to the vertical plane in four subjects. Multiple ramifications were radially distributed from the P A in eight subjects, whereas one predominant P A-D branched from the P A in six subjects. Based on the diverging points of the P A-D and P LL , we proposed a three-step method for the detection and diagnosis of RSRL.

Coronal mass ejection shock fronts containing the two types of intermediate shocks

International Nuclear Information System (INIS)

Steinolfson, R.S.; Hundhausen, A.J.

1990-01-01

Numerical solutions of the time-dependent, magnetohydrodynamic (MHD) equations in two dimensions are used to demonstrate the formation of both types of intermediate shocks in a single shock front for physical conditions that are an idealization of those expected to occur in some observed coronal mass ejections. The key to producing such a shock configuration in the simulations is the use of an initial atmosphere containing a magnetic field representative of that in a coronal streamer with open field lines overlying a region of closed field lines. Previous attempts using just open field lines (perpendicular to the surface) produced shock configurations containing just one of the two intermediate shock types. A schematic of such a shock front containing both intermediate shock types has been constructed previously based solely on the known properties of MHD shocks from the Rankine-Hugoniot equations and specific requirements placed on the shock solution at points along the front where the shock normal and upstream magnetic field are aligned. The shock front also contains, at various locations along the front, a hydrodynamic (nonmagnetic) shock, a switch-on shock, and a fast shock in addition to the intermediate shocks. This particular configuration occurs when the shock front speed exceeds the upstream (preshock) intermediate wave speed but is less than a critical speed defined in the paper (equation 1) along at least some portion of the shock front. A distinctive feature of the front is that it is concave upward (away from the surface) near the region where the field in the preshock plasma is normal to the front of near the central portion of the shock front

[MK-801 or DNQX reduces electroconvulsive shock-induced impairment of learning-memory and hyperphosphorylation of Tau in rats].

Science.gov (United States)

Liu, Chao; Min, Su; Wei, Ke; Liu, Dong; Dong, Jun; Luo, Jie; Liu, Xiao-Bin

2012-08-25

This study explored the effect of the excitatory amino acid receptor antagonists on the impairment of learning-memory and the hyperphosphorylation of Tau protein induced by electroconvulsive shock (ECT) in depressed rats, in order to provide experimental evidence for the study on neuropsychological mechanisms improving learning and memory impairment and the clinical intervention treatment. The analysis of variance of factorial design set up two intervention factors which were the electroconvulsive shock (two level: no disposition; a course of ECT) and the excitatory amino acid receptor antagonists (three level: iv saline; iv NMDA receptor antagonist MK-801; iv AMPA receptor antagonist DNQX). Forty-eight adult Wistar-Kyoto (WKY) rats (an animal model for depressive behavior) were randomly divided into six experimental groups (n = 8 in each group): saline (iv 2 mL saline through the tail veins of WKY rats ); MK-801 (iv 2 mL 5 mg/kg MK-801 through the tail veins of WKY rats) ; DNQX (iv 2 mL 5 mg/kg DNQX through the tail veins of WKY rats ); saline + ECT (iv 2 mL saline through the tail veins of WKY rats and giving a course of ECT); MK-801 + ECT (iv 2 mL 5 mg/kg MK-801 through the tail veins of WKY rats and giving a course of ECT); DNQX + ECT (iv 2 mL 5 mg/kg DNQX through the tail veins of WKY rats and giving a course of ECT). The Morris water maze test started within 1 day after the finish of the course of ECT to evaluate learning and memory. The hippocampus was removed from rats within 1 day after the finish of Morris water maze test. The content of glutamate in the hippocampus of rats was detected by high performance liquid chromatography. The contents of Tau protein which included Tau5 (total Tau protein), p-PHF1(Ser396/404), p-AT8(Ser199/202) and p-12E8(Ser262) in the hippocampus of rats were detected by immunohistochemistry staining (SP) and Western blot. The results showed that ECT and the glutamate ionic receptor blockers (NMDA receptor antagonist MK-801 and

A Tight Spot After Pulmonary Vein Catheter Ablation

NARCIS (Netherlands)

Amir, Rabia; Yeh, Lu; Montealegre-Gallegos, Mario; Saraf, Rabya; Matyal, Robina; Mahmood, Feroze

2016-01-01

A 52-YEAR-OLD woman with a history of embolic stroke due to paroxysmal atrial fibrillation was referred to the authors’ institution for epicardial surgical pulmonary vein isolation with left atrial appendage resection. The patient had 2 previous failed pulmonary vein catheter ablations. Dense

CO2-DSA in lower extremity veins: a clinical application

International Nuclear Information System (INIS)

Guo Jinhe; Teng Gaojun; Zhu Guangyu; Liu Zhensheng; Li Guozhao; Ding Huijuan; Shen Zhiping; He Shicheng; Deng Gang; Fang Wen

2005-01-01

Objective: To explore the feasibility and usefulness of carbon dioxide digital subtraction angiography (CO 2 -DSA) in deep veins of lower extremity via the dorsal is pedis vein. Methods: CO 2 -DSA in lower extremity veins was performed in 15 patients (15 limbs affected, male 9, female 6) by injection of CO 2 via the dorsal is pedis vein. Among them, 8 patients were suspected with deep venous thrombosis (DVT), 6 patients with saphena magna dilation, and 1 patient with a follow-up after thrombolysis due to DVT. Results: Excellent image was obtained in 12 cases, which showed branches of the venous system clearly, as well as the details of DVT. Good image was obtained in 2 cases. Technical failure was encountered in one patient due to inaccessible puncture veins. Mild discomfort (transient pain at the percutaneous site) during the procedure was demonstrated in 11 patients. There was no severe side effects or complications in this series. Conclusion: CO 2 -DSA in lower extremity veins is feasible and safe, the preliminary result is satisfactory. (authors)

Updated cannulation technique for tissue plasminogen activator injection into peripapillary retinal vein for central retinal vein occlusion.

Science.gov (United States)

van Overdam, Koen A; Missotten, Tom; Spielberg, Leigh H

2015-12-01

To update the surgical technique in which a vitrectomy is performed and a retinal branch vein is cannulated and infused with recombinant tissue plasminogen activator (RTPA) to treat central retinal vein occlusion (CRVO) in patients who present with very low visual acuity (VA). Twelve consecutive patients (12 eyes) with CRVO and low VA (logMAR >1.00) at presentation were treated using this method. Cannulation of a peripapillary retinal vein and stable injection of RTPA was successfully performed without surgery-related complications in all 12 eyes. At 12 months after surgery, 8 of the 12 patients (67%) experienced at least one line of improvement in best corrected visual acuity; 6 of the 12 (50%) improved ≥5 lines and 2 (17%) improved ≥8 lines. After additional grid laser and/or subconjunctival or intravitreal corticosteroids, the mean decrease in central foveal thickness was 260 μm, and the mean total macular volume decreased from 12.10 mm(3) to 9.24 mm(3) . Four patients received panretinal photocoagulation to treat either iris neovascularization (n = 2) or neovascularization of the retina and/or disc (n = 2). Administration of RTPA via a peripapillary vein using this updated technique provides an alternative or additional treatment option for patients with very low VA after CRVO. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Melting of Dense Sodium

International Nuclear Information System (INIS)

Gregoryanz, Eugene; Degtyareva, Olga; Hemley, Russell J.; Mao, Ho-kwang; Somayazulu, Maddury

2005-01-01

High-pressure high-temperature synchrotron diffraction measurements reveal a maximum on the melting curve of Na in the bcc phase at ∼31 GPa and 1000 K and a steep decrease in melting temperature in its fcc phase. The results extend the melting curve by an order of magnitude up to 130 GPa. Above 103 GPa, Na crystallizes in a sequence of phases with complex structures with unusually low melting temperatures, reaching 300 K at 118 GPa, and an increased melting temperature is observed with further increases in pressure

A 2D double-porosity model for melting and melt migration beneath mid-oceanic ridges

Science.gov (United States)

Liu, B.; Liang, Y.; Parmentier, E.

2017-12-01

Several lines of evidence suggest that the melting and melt extraction region of the MORB mantle is heterogeneous consisting of an interconnected network of high permeability dunite channels in a low porosity harzburgite or lherzolite matrix. In principle, one can include channel formation into the tectonic-scale geodynamic models by solving conservation equations for a chemically reactive and viscously deformable porous medium. Such an approach eventually runs into computational limitations such as resolving fractal-like channels that have a spectrum of width. To better understand first order features of melting and melt-rock interaction beneath MOR, we have formulated a 2D double porosity model in which we treat the triangular melting region as two overlapping continua occupied by the low-porosity matrix and interconnected high-porosity channels. We use melt productivity derived from a thermodynamic model and melt suction rate to close our problem. We use a high-order accurate numerical method to solve the conservation equations in 2D for porosity, solid and melt velocities and concentrations of chemical tracers in the melting region. We carry out numerical simulations to systematically study effects of matrix-to-channel melt suction and spatially distributed channels on the distributions of porosity and trace element and isotopic ratios in the melting region. For near fractional melting with 10 vol% channel in the melting region, the flow field of the matrix melt follows closely to that of the solid because the small porosity (exchange between the melt and the solid. The smearing effect can be approximated by dispersion coefficient. For slowly diffusing trace elements (e.g., LREE and HFSE), the melt migration induced dispersion can be as effective as thermal diffusion. Therefore, sub-kilometer scale heterogeneities of Nd and Hf isotopes are significantly damped or homogenized in the melting region.

Fluids in crustal deformation: Fluid flow, fluid-rock interactions, rheology, melting and resources

Science.gov (United States)

Lacombe, Olivier; Rolland, Yann

2016-11-01

Fluids exert a first-order control on the structural, petrological and rheological evolution of the continental crust. Fluids interact with rocks from the earliest stages of sedimentation and diagenesis in basins until these rocks are deformed and/or buried and metamorphosed in orogens, then possibly exhumed. Fluid-rock interactions lead to the evolution of rock physical properties and rock strength. Fractures and faults are preferred pathways for fluids, and in turn physical and chemical interactions between fluid flow and tectonic structures, such as fault zones, strongly influence the mechanical behaviour of the crust at different space and time scales. Fluid (over)pressure is associated with a variety of geological phenomena, such as seismic cycle in various P-T conditions, hydrofracturing (including formation of sub-horizontal, bedding-parallel veins), fault (re)activation or gravitational sliding of rocks, among others. Fluid (over)pressure is a governing factor for the evolution of permeability and porosity of rocks and controls the generation, maturation and migration of economic fluids like hydrocarbons or ore forming hydrothermal fluids, and is therefore a key parameter in reservoir studies and basin modeling. Fluids may also help the crust partially melt, and in turn the resulting melt may dramatically change the rheology of the crust.

Energy Saving Melting and Revert Reduction Technology: Melting Efficiency in Die Casting Operations

Energy Technology Data Exchange (ETDEWEB)

David Schwam

2012-12-15

This project addressed multiple aspects of the aluminum melting and handling in die casting operations, with the objective of increasing the energy efficiency while improving the quality of the molten metal. The efficiency of melting has always played an important role in the profitability of aluminum die casting operations. Consequently, die casters need to make careful choices in selecting and operating melting equipment and procedures. The capital cost of new melting equipment with higher efficiency can sometimes be recovered relatively fast when it replaces old melting equipment with lower efficiency. Upgrades designed to improve energy efficiency of existing equipment may be well justified. Energy efficiency is however not the only factor in optimizing melting operations. Melt losses and metal quality are also very important. Selection of melting equipment has to take into consideration the specific conditions at the die casting shop such as availability of floor space, average quantity of metal used as well as the ability to supply more metal during peaks in demand. In all these cases, it is essential to make informed decisions based on the best available data.

demystifying the shock of shocking

African Journals Online (AJOL)

(with a pulse), atrial fibrillation and atrial flutter. The energy dose in cardioversion is less (0.5. - 2 J/kg) than in defibrillation (2 - 4 J/kg). In cardioversion the shock is discharged synchronously with the native R wave of the patient. Without synchronisation,. VF can be induced if a shock is delivered during the refractory period ...

Renal vein thrombosis mimicking urinary calculus: a dilemma of diagnosis.

Science.gov (United States)

Wang, Yimin; Chen, Shanwen; Wang, Wei; Liu, Jianyong; Jin, Baiye

2015-07-02

Renal vein thrombosis (RVT) with flank pain, and hematuria, is often mistaken with renal colic originating from ureteric or renal calculus. Especially in young and otherwise healthy patients, clinicians are easily misled by clinical presentation and calcified RVT. A 38-year-old woman presented with flank pain and hematuria suggestive of renal calculus on ultrasound. She underwent extracorporeal shock wave lithotripsy that failed, leading to the recommendation that percutaneous lithotomy was necessary to remove the renal calculus. In preoperative view of the unusual shape of the calculus without hydronephrosis, noncontrast computed tomography was taken and demonstrated left ureteric calculus. However computed tomography angiography revealed, to our surprise, a calcified RVT that was initially thought to be a urinary calculus. This case shows that a calcified RVT might mimic a urinary calculus on conventional ultrasonography and ureteric calculus on noncontrast computed tomography. Subsequent computed tomography angiography disclosed that a calcified RVT caused the imaging findings, thus creating a potentially dangerous clinical pitfall. Hence, it is suggested that the possibility of a RVT needs to be considered in the differential diagnosis whenever one detects an uncommon shape for a urinary calculus.

Evidence for a Meteoritic Component in Impact Melt Rock from the Chicxulub Structure

Science.gov (United States)

Koeberl, Christian; Sharpton, Virgil L.; Schuraytz, Benjamin C.; Shirey, Steven B.; Blum, Joel D.; Marin, Luis E.

1994-01-01

The Chicxulub structure in Yucatan, Mexico, has recently been recognized as a greater then 200-km-diameter multi-ring impact crater of K-T boundary age. Crystalline impact melt rocks and breccias from within the crater, which have compositions similar to those of normal continental crustal rocks and which show shock metamorphic effects, have been studied for trace element and Re-Os isotope compositions. Re-Os isotope systematics allow the sensitive and selective determination of an extraterrestrial component in impact-derived rocks. A melt rock sample shows elevated iridium concentrations, an osmium concentration of 25 ppb, and a low Os-187/Os-188 ratio of 0.113, which are incompatible with derivation from the continental crust. Even though the Os-187/Os-188 ratio is slightly lower than the range so far measured in meteorites, a mantle origin seems unlikely for mass balance reasons and because the cratering event is unlikely to have excavated mantle material. The data support the hypothesis of a heterogeneously distributed meteoritic component in the Chicxulub melt rock. A sample of impact glass from the Haitian K-T boundary at Beloc yielded about 0.1 ppb osmium and an Os-187/0s-188 ratio of 0.251, indicating the presence of a small meteoritic component in the impact ejecta as well.

Shock absorbing structure

International Nuclear Information System (INIS)

Kojima, Naoki; Matsushita, Kazuo.

1992-01-01

Small pieces of shock absorbers are filled in a space of a shock absorbing vessel which is divided into a plurality of sections by partitioning members. These sections function to prevent excess deformation or replacement of the fillers upon occurrence of falling accident. Since the shock absorbing small pieces in the shock absorbing vessel are filled irregularly, shock absorbing characteristics such as compression strength is not varied depending on the direction, but they exhibit excellent shock absorbing performance. They surely absorb shocks exerted on a transportation vessel upon falling or the like. If existing artificial fillers such as pole rings made of metal or ceramic and cut pieces such as alumium extrusion molding products are used as the shock absorbing pieces, they have excellent fire-proofness and cold resistance since the small pieces are inflammable and do not contain water. (T.M.)

Fuel Rod Melt Progression Simulation Using Low-Temperature Melting Metal Alloy

International Nuclear Information System (INIS)

Seung Dong Lee; Suh, Kune Y.; GoonCherl Park; Un Chul Lee

2002-01-01

The TMI-2 accident and various severe fuel damage experiments have shown that core damage is likely to proceed through various states before the core slumps into the lower head. Numerous experiments were conducted to address when and how the core can lose its original geometry, what geometries are formed, and in what processes the core materials are transported to the lower plenum of the reactor pressure vessel. Core degradation progresses along the line of clad ballooning, clad oxidation, material interaction, metallic blockage, molten pool formation, melt progression, and relocation to the lower head. Relocation into the lower plenum may occur from the lateral periphery or from the bottom of the core depending upon the thermal and physical states of the pool. Determining the quantities and rate of molten material transfer to the lower head is important since significant amounts of molten material relocated to the lower head can threaten the vessel integrity by steam explosion and thermal and mechanical attack of the melt. In this paper the focus is placed on the melt flow regime on a cylindrical fuel rod utilizing the LAMDA (Lumped Analysis of Melting in Degrading Assemblies) facility at the Seoul National University. The downward relocation of the molten material is a combination of the external film flow and the internal pipe flow. The heater rods are 0.8 m long and are coated by a low-temperature melting metal alloy. The electrical internal heating method is employed during the test. External heating is adopted to simulate the exothermic Zircaloy-steam reaction. Tests are conducted in several quasi-steady-state conditions. Given the variable boundary conditions including the heat flux and the water level, observation is made for the melting location, progression, and the mass of molten material. Finally, the core melt progression model is developed from the visual inspection and quantitative analysis of the experimental data. As the core material relocates

CT of portal vein tumor thrombosis. Usefulness of dynamic CT

Energy Technology Data Exchange (ETDEWEB)

Takemoto, Kazumasa; Inoue, Yuichi; Tanaka, Masahiro; Nemoto, Yutaka; Nakamura, Kenji [Osaka City Univ. (Japan). Faculty of Medicine

1983-08-01

We evaluated CT findings of portal vein tumor thrombosis in 16 hepatomas by plain, contrast and dynamic CT. Plain and contrast CT findings were an enlargement of the portal vein (81%), intraluminal low density area (63%). Dynamic CT enhanced the diagnostic capability of the tumor thrombus as a relatively low density area because of the marked enhancement of the portal vein. In addition, dynamic CT newly demonstrated hyperdense peripheral ring (35%) and arterio portal shunt (35%). It is advisable to select the scan level to include the portal vein when dynamic CT is performed in the patient of hepatocellular carcinoma.

Palm vein recognition based on directional empirical mode decomposition

Science.gov (United States)

Lee, Jen-Chun; Chang, Chien-Ping; Chen, Wei-Kuei

2014-04-01

Directional empirical mode decomposition (DEMD) has recently been proposed to make empirical mode decomposition suitable for the processing of texture analysis. Using DEMD, samples are decomposed into a series of images, referred to as two-dimensional intrinsic mode functions (2-D IMFs), from finer to large scale. A DEMD-based 2 linear discriminant analysis (LDA) for palm vein recognition is proposed. The proposed method progresses through three steps: (i) a set of 2-D IMF features of various scale and orientation are extracted using DEMD, (ii) the 2LDA method is then applied to reduce the dimensionality of the feature space in both the row and column directions, and (iii) the nearest neighbor classifier is used for classification. We also propose two strategies for using the set of 2-D IMF features: ensemble DEMD vein representation (EDVR) and multichannel DEMD vein representation (MDVR). In experiments using palm vein databases, the proposed MDVR-based 2LDA method achieved recognition accuracy of 99.73%, thereby demonstrating its feasibility for palm vein recognition.

[Cockett's syndrome, May-Thurner syndrome, or iliac vein compression syndrome].

Science.gov (United States)

Gil Martín, A R; Carreras Aja, M; Arrieta Ardieta, I; Labayen Azparren, I

2014-01-01

Iliac vein compression syndrome (also known as May-Thurner syndrome or Cockett's syndrome) is a rare clinical entity in which the left common iliac vein is compressed when it passes between the right common iliac artery and the spine. The sustained compression and trauma caused by the pulsatile force of the artery on the vein damage the intima and lead to the formation of membranes or bands in the vascular lumen that hinder or obstruct the flow of blood in the vein, favoring thrombus formation. The current treatment strategy of choice is endovascular vein patch angioplasty and stenting with the aim of improving the caliber of the lumen and enabling normal venous drainage. We present two cases of May-Thurner syndrome and review the clinical and CT findings. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

Shock and Rarefaction Waves in a Heterogeneous Mantle

Science.gov (United States)

Jordan, J.; Hesse, M. A.

2012-12-01

has a zero eigenvalue, corresponding to a wave speed of zero, which preserves a residual imprint of the initial condition. Freezing fronts textemdash those that result in a negative change in porositytextemdash feature fast path waves that travel as shocks, whereas the fast path waves of melting fronts travel as spreading, rarefaction waves.

Pattern of venous collateral development after splenic vein occlusion in an extended Whipple procedure : comparison with collateral vein pattern in cases of sinistral portal hypertension.

Science.gov (United States)

Strasberg, Steven M; Bhalla, Sanjeev; Sanchez, Luis A; Linehan, David C

2011-11-01

The risks of developing sinistral portal hypertension as a result of occlusion of the splenic vein close to its termination during a Whipple procedure are unclear. Our purpose was to compare the pattern of venous collateral development after splenic vein ligation in an extended Whipple procedure with the pattern of collateral development in cases of sinistral portal hypertension. Five patients underwent an extended Whipple procedure in which the splenic vein was divided and not reconstructed. Six to eight months later detailed mapping of venous return from the spleen was determined by contrast-enhanced multidetector computed tomography or in one case by 3D contrast-enhanced MRI. Spleen size and length of residual patent splenic vein were also measured. The literature on sinistral portal hypertension was evaluated to ascertain whether the venous collateral pattern in cases of left-sided portal hypertension was similar to the pattern that developed when the splenic vein was ligated at its termination in the Whipple procedure. A length of splenic vein remained patent in all five patients, measuring 4.5 to 11.5 cm from the spleen. Splenomegaly did not develop. Blood returned from the spleen by multiple collaterals including collaterals in the omentum and mesocolon. These types of collaterals do not develop in sinistral portal hypertension, nor is residual patent splenic vein seen. Ligation of the splenic vein close to its termination in five patients resulted in a pattern of venous return different from patients that have developed left-sided portal hypertension.

Study on Reflected Shock Wave/Boundary Layer Interaction in a Shock Tube

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Wook; Kim, Tae Ho; Kim, Heuy Dong [Andong Nat’l Univ., Andong (Korea, Republic of)

2017-07-15

The interaction between a shock wave and a boundary layer causes boundary layer separation, shock train, and in some cases, strong unsteadiness in the flow field. Such a situation is also observed in a shock tube, where the reflected shock wave interacts with the unsteady boundary layer. However, only a few studies have been conducted to investigate the shock train phenomenon in a shock tube. In the present study, numerical studies were conducted using the two-dimensional axisymmetric domain of a shock tube, and compressible Navier-Stokes equations were solved to clarify the flow characteristics of shock train phenomenon inside a shock tube. A detailed wave diagram was developed based on the present computational results, which were validated with existing experimental data.

A rare case of anastomosis between the external and internal jugular veins.

Science.gov (United States)

Karapantzos, Ilias; Zarogoulidis, Paul; Charalampidis, Charalampos; Karapantzou, Chrysanthi; Kioumis, Ioannis; Tsakiridis, Kosmas; Mpakas, Andrew; Sachpekidis, Nikolaos; Organtzis, John; Porpodis, Konstantinos; Zarogoulidis, Konstantinos; Pitsiou, Georgia; Zissimopoulos, Athanasios; Kosmidis, Christoforos; Fouka, Evagelia; Demetriou, Theodoros

2016-01-01

Jugular veins bring deoxygenated blood from the head back to the heart. There are two sets of external and internal veins. The external jugular vein receives the greater part of the blood from the cranium and the deep parts of the face. It commences from the substance of the parotid gland and runs down the neck at the posterior border of sternocleidomastoideus and ends in the subclavian vein in front of the scalenus anterior. The external jugular vein is covered by the platysma and its upper half runs parallel with the great auricular nerve. There is also another minor jugular vein, the anterior, draining the submaxillary region. In our patient, we recognized a shunt between the external and internal jugular veins. It appeared in the middle of the veins, between the pair of valves, which are placed ~2.5 cm above the termination of the vessel. The anastomosis was fully functional, and there was no problem in the blood pressure of the patient. Moreover, the shunt was not associated with any systemic disease.

Shock-tube study of fusion plasma-wall interactions

International Nuclear Information System (INIS)

Gross, R.A.; Tien, J.K.; Jensen, B.; Panayotou, N.F.; Feinberg, B.

1977-01-01

Theoretical and experimental studies have been made of phenomena which occur when a hot (T 1 approximately equal to 6 x 10 6 0 K), dense (n approximately equal to 10 16 cm -3 ), deuterium plasma containing a transverse magnetic field is brought into sudden contact with a cold metal wall. These studies are motivated by the need to understand plasma and metallurgical conditions at the first-wall of a fusion reactor. Experiments were carried out in the Columbia high energy electromagnetic shock tube. Computational simulation was used to investigate the detailed physics of the fusion plasma boundary layer which develops at the wall. The rate of energy transfer from the plasma to the wall was calculated and conditions under which surface melting occurs are estimated. Experimental measurements of plasma-wall heat transfer rates up to 3 x 10 5 watts/cm 2 were obtained and agreement with computed values are good. Fusion reactor first-wall materials have been exposed to 6.0 x 10 21 eV cm -2 (1,000 shots) of deuterium plasma bombardment. Scanning electron micrograph photographs show preferential erosion at grain boundaries, formation of deuterium surface blisters, and evidence of local surface melting. Some cracking is observed along grain boundaries, and a decrease in tensile ductiity is measured

Quartz-molybdenite veins in the Priestly Lake granodiorite, north-central Maine

Science.gov (United States)

Ayuso, Robert A.; Shank, Stephen G.

1983-01-01

Quartz-molybdenite veins up to 15 cm in width occur in fine to medium-grained porphyritic biotite-hornblende granodiorite at Priestly Lake north-central Maine. An area of about 150 m x 150 m contains quartz-molybdenite veins; a larger area is characterized by barren quartz veins. Quartz-molybdenite veins are concentrated within the most felsic variants of the intrusion as suggested by lower mafic mineral contents. The pluton has a narrow range in SiO2 (67-70 wt.%), major oxides, and in trace-element compositions. Molybdenite occurs as coarse grained clusters in pockets within the quartz veins, and fills fractures in the quartz veins and host rocks. Disseminated molybdenite in the granodiorite is relatively rare and occurs only in the area characterized by a high density of quartz veins (up to 50 veins per square meter). Alteration envelopes along the quartz veins are very thin or absent, although in some areas the granodiorite appears to be selectively and pervasively altered. Sericite, chlorite, epidote, calcite, pyrite, and quartz are concentrated near the quartz-molybdenite veins. Many of the field and geochemical characteristics of the Priestly Lake pluton are unlike those of major molybdenum-producing areas (Climax, Henderson, Urad). For example, the area of alteration seems to be of limited extent, the host rock is not intensely altered hydrothermally at the surface, the density of fractures is rather low in the mineralized area, and the amount of disseminated molybdenite appears to be small. However, the Priestly Lake pluton may be a small fraction of a concealed batholith as suggested by geophysical data. It is conceivable that the type of mineralization at the surface might be the expression of more extensive molybdenite mineralization at depth. The quartz-molybdenite veins in the Priestly Lake pluton are significant because they indicate that potential molybdenum sources for producing mineralized granites were available at depth. Future studies should be

A new design concept for knitted external vein-graft support mesh.

Science.gov (United States)

Singh, Charanpreet; Wang, Xungai

2015-08-01

Autologous vein-graft failure significantly limits the long-term efficacy of coronary artery bypass procedures. The major cause behind this complication is biomechanical mismatch between the vein and coronary artery. The implanted vein experiences a sudden increase (10-12 fold) in luminal pressures. The resulting vein over-distension or 'ballooning' initiates wall thickening phenomenon and ultimate occlusion. Therefore, a primary goal in improving the longevity of a coronary bypass procedure is to inhibit vein over-distension using mechanical constriction. The idea of using an external vein-graft support mesh has demonstrated sustained benefits and wide acceptance in experimental studies. Nitinol based knitted structures have offered more promising mechanical features than other mesh designs owing to their unique loosely looped construction. However, the conventional plain knit construction still exhibits limitations (radial compliance, deployment ease, flexibility, and bending stresses) which limit this design from proving its real clinical advantage. The new knitted mesh design presented in this study is based on the concept of composite knitting utilising high modulus (nitinol and polyester) and low modulus (polyurethane) material components. The experimental comparison of the new design with a plain knit design demonstrated significant improvement in biomechanical (compliance, flexibility, extensibility, viscoelasticity) and procedural (deployment limit) parameters. The results are indicative of the promising role of new mesh in restoring the lost compliance and pulsatility of vein-graft at high arterial pressures. This way it can assist in controlled vein-graft remodelling and stepwise restoration of vein mechanical homoeostasis. Also, improvement in deployment limit parameter offers more flexibility for a surgeon to use a wide range of vein diameters, which may otherwise be rendered unusable for a plain knit mesh. Copyright © 2015 Elsevier Ltd. All rights

Anatomical variations of the right hepatic veins and their relevance to surgery.

Science.gov (United States)

Hribernik, Marija; de Cecchis, Lucio; Trotovsek, Blaz; Gadzijev, Eldar M; Ravnik, Dean

2003-01-01

In a morphological study of the right hepatic veins anatomical characteristics of surgical importance were looked for. 110 cadaveric human livers were prepared by the corrosion casts method. The confluence patterns of the superior right hepatic vein, the hepatocaval confluence, the accessory right hepatic veins and the anastomoses between hepatic veins in the right hemiliver were examined. Four types of the superior right hepatic vein, based on the length of its trunk and the confluence pattern of its main tributaries were determined and their frequency was calculated. Type I was found in 20%, type II in 40%, type III in 25% and type IV in 15%. Accessory right hepatic veins with a minimal caliber of 0.4 cm, which were always present in type IV, were also found in other types, all together in 27% of the casts. The tributary-free part of the superior right hepatic vein at hepatocaval confluence was longer than 1 cm in 77%. In the right hemiliver 109 anastomoses were found in 29/110 liver casts. Knowing the characteristics of different superior right hepatic vein types and of the accessory right hepatic veins may be useful in segment-oriented liver resections and in right side living donor resections.

Inferior vena cava filter insertion through the popliteal vein: enabling the percutaneous endovenous intervention of deep vein thrombosis with a single venous access approach in a single session

Science.gov (United States)

Kim, Hyoung Ook; Kim, Jae Kyu; Park, Jin Gyoon; Yim, Nam Yeol; Kang, Yang Jun; Jung, Hye Doo

2016-01-01

PURPOSE We aimed to evaluate the efficiency of placing an inferior vena cava (IVC) filter through the same popliteal vein access site used for percutaneous endovenous intervention in patients with extensive lower extremity deep vein thrombosis. METHODS This retrospective study included 21 patients who underwent IVC filter insertion through the popliteal vein over a three-year period. Patient medical records were reviewed for the location of the deep vein thrombosis, result of filter removal, and total number of endovascular procedures needed for filter insertion and recanalization of the lower extremity venous system. Follow-up lower extremity computed tomography (CT) venography was also reviewed in each patient to assess the degree of filter tilt in the IVC. RESULTS All patients had extensive lower extremity deep vein thrombosis involving the iliac vein and/or femoral vein. Seventeen patients showed deep vein thrombosis of the calf veins. In all patients, IVC filter insertion and the recanalization procedure were performed during a single procedure through the single popliteal vein access site. In the 17 patients undergoing follow-up CT, the mean tilt angle of the filter was 7.14°±4.48° in the coronal plane and 8.77°±5.49° in the sagittal plane. Filter retrieval was successful in 16 of 17 patients (94.1%) in whom filter retrieval was attempted. CONCLUSION Transpopliteal IVC filter insertion is an efficient technique that results in low rates of significant filter tilt and enables a single session procedure using a single venous access site for filter insertion and percutaneous endovenous intervention. PMID:27559713

Formation of quartz veins by local dissolution and transport of silica

Energy Technology Data Exchange (ETDEWEB)

Wangen, Magnus; Munz, Ingrid Anne

2004-08-01

A simple model is proposed for the (often) thick quartz veins observed in the Modum Complex in Southern Norway. The formation of these veins cannot easily be explained by silica imported by hot ascending fluids. The proposed model has dissolution in the host rock adjacent to the veins as the source for silica. The suggested process for vein formation is represented by a reaction-diffusion equation, and the process is studied in terms of a Damkoehler number. Estimates for the growth rate of quartz cement are derived. The estimates for the growth rate can be used to constrain poorly known parameters of the vein formation process, like for instance, the degree of supersaturation in the host rock. (Author)

Primary extraskeletal mesenchymal chondrosarcoma arising from the iliac vein

Directory of Open Access Journals (Sweden)

Hua Zhang

2017-10-01

Full Text Available The iliac vein is an extremely rare site for mesenchymal chondrosarcoma, and patients with primary extraskeletal mesenchymal chondrosarcoma arising from a vein always suffer a very poor prognosis. We report a case of a 45-year-old female who presented with a 5-month history of left leg edema in 2015. Contrast-enhanced computed tomography showed a large mass in the left iliac vein with scattered calcifications. Wide-margin resection was performed, and histopathologic and immunohistochemical analyses confirmed the presence of intraluminal mesenchymal chondrosarcoma with local invasion out of the vein wall. Due to poor patient compliance, postoperative neoadjuvant chemotherapy and radiotherapy were not started, and a bone scan performed 16 weeks postoperatively showed multiple bone metastases. The patient died on the twenty-fourth postoperative week.

Iliac Vein Compression Syndrome due to Bladder Distention Caused by Urethral Calculi

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Akiko Ikegami

2015-01-01

Full Text Available We report a rare case of iliac vein compression syndrome caused by urethral calculus. A 71-year-old man had a history of urethral stenosis. He complained of bilateral leg edema and dysuria for 1 week. Physical examination revealed bilateral distention of the superficial epigastric veins, so obstruction of both common iliac veins or the inferior vena cava was suspected. Plain abdominal computed tomography showed a calculus in the pendulous urethra, distention of the bladder (as well as the right renal pelvis and ureter, and compression of the bilateral common iliac veins by the distended bladder. Iliac vein compression syndrome was diagnosed. Bilateral iliac vein compression due to bladder distention (secondary to neurogenic bladder, benign prostatic hyperplasia, or urethral calculus as in this case is an infrequent cause of acute bilateral leg edema. Detecting distention of the superficial epigastric veins provides a clue for diagnosis of this syndrome.

The study of multi-detector CT on the grouping and measuring of the hepatic veins

International Nuclear Information System (INIS)

Wang Xianliang; Dong Guang; Geng Hai; Wang Wengang; Li Linkun; Gao Wei; Wang Rongfang

2007-01-01

Objective: To study the three-dimensional topography of the hepatic vein (HV), the inferior vena cava(IVC) and the inferior right hepatic vein(IRHV) in the retrohepatic and pre-IVC tunnel in human beings, and to provide an anatomic reference for liver surgery. Methods: One hundred and ten volunteers underwent CT scanning at 60 to 75 s after injection of contrast medium, and their HV, IVC and IRHV were reconstructed into MPR and 3D-MIP images. The hepatic veins were grouped according to the way by which the hepatic vein enters IVC. The angle between the right hepatic vein and the middle hepatic vein or the trunk of hepatic vein was measured, and the width from right hepatic vein to middle hepatic vein or to the trunk of hepatic vein on IVC was recorded. The frequency of IRHV was observed, and the length of the tunnel was measured. Results: Among the 110 volunteers, there were 6 cases (5.45%) with three hepatic veins respectively entering IVC, 98 cases (89.10%) with right hepatic vein and a common trunk of the middle hepatic vein and the left hepatic vein entering IVC, and 6 cases (5.45%) with left hepatic vein and a common trunk of the right hepatic vein and the middle hepatic vein entering IVC. The mean value of the angles between the right hepatic vein and the middle hepatic vein or the mink of hepatic vein was (55 ± 18) degree. The width from the right hepatic vein to the middle hepatic vein or to the trunk of hepatic vein was (21 ± 7)mm. The IRHV was observed in 30 cases(27.27%). The mean value of the tunnel length was (53 ± 11) mm. Conclusion: The parameters of the retrohepatic and pre-IVC tunnel in human beings can be measured accurately by the imaging of MPR, which can provide an anatomic reference for the liver surgery. (authors)

Collisionless electrostatic shocks

DEFF Research Database (Denmark)

Andersen, H.K.; Andersen, S.A.; Jensen, Vagn Orla

1970-01-01

An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth......An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth...

Right ovarian vein drainage variant: Is there a relationship with pelvic varices?

International Nuclear Information System (INIS)

Koc, Zafer; Ulusan, Serife; Oguzkurt, Levent

2006-01-01

Objective: To correlate right ovarian vein (ROV) variations that drain into the right renal vein (RRV) with the presence of pelvic varices. Materials and methods: Routine abdominal multidetector-row computed tomography scans of 324 women were analyzed for the presence and type of ROV variations in this retrospective study. The subjects were divided into 2 groups: those with ROV variations and those without such variations. The diameters of the subjects' ROV, left ovarian vein (LOV), and parauterine veins were measured. Pelvic varices and the presence and degree of ovarian vein reflux were noted and compared between the 2 groups. The χ 2 -test and the Pearson correlation test were used for statistical analysis. Results: Thirty-two (9.9%) of 324 women studied exhibited ROV variant that drained into the right renal vein, and the remaining subjects (90.1%) exhibited a normal pattern of ROV drainage that flowed directly into the inferior vena cava. Pelvic varices were identified in 59 (18%) of the subjects. Reflux was not observed in any patient without pelvic varices. Fifty-seven of 59 women exhibited ovarian vein reflux. In 56 of those 57 individuals, reflux occurred only in the LOV, and in 1 subject, reflux was noted predominantly in the ROV. No significant relationship between the presence of an ROV that drained into the right renal vein and pelvic varices was noted. Conclusion: Although right-sided pelvic varices associated with right ovarian vein drainage variations are rare, anatomic variations of the right ovarian vein are not. This study did not find an association between the presence of right ovarian vein and pelvic varices

Right ovarian vein drainage variant: Is there a relationship with pelvic varices?

Energy Technology Data Exchange (ETDEWEB)

Koc, Zafer [Baskent Universitesi, Adana Hastanesi, Radyoloji Boeluemue, Serin Evler 39, Sok. No. 6 Yueregir, Adana (Turkey)]. E-mail: koczafer@gmail.com; Ulusan, Serife [Baskent Universitesi, Adana Hastanesi, Radyoloji Boeluemue, Serin Evler 39, Sok. No. 6 Yueregir, Adana (Turkey); Oguzkurt, Levent [Baskent Universitesi, Adana Hastanesi, Radyoloji Boeluemue, Serin Evler 39, Sok. No. 6 Yueregir, Adana (Turkey)

2006-09-15

Objective: To correlate right ovarian vein (ROV) variations that drain into the right renal vein (RRV) with the presence of pelvic varices. Materials and methods: Routine abdominal multidetector-row computed tomography scans of 324 women were analyzed for the presence and type of ROV variations in this retrospective study. The subjects were divided into 2 groups: those with ROV variations and those without such variations. The diameters of the subjects' ROV, left ovarian vein (LOV), and parauterine veins were measured. Pelvic varices and the presence and degree of ovarian vein reflux were noted and compared between the 2 groups. The {chi}{sup 2}-test and the Pearson correlation test were used for statistical analysis. Results: Thirty-two (9.9%) of 324 women studied exhibited ROV variant that drained into the right renal vein, and the remaining subjects (90.1%) exhibited a normal pattern of ROV drainage that flowed directly into the inferior vena cava. Pelvic varices were identified in 59 (18%) of the subjects. Reflux was not observed in any patient without pelvic varices. Fifty-seven of 59 women exhibited ovarian vein reflux. In 56 of those 57 individuals, reflux occurred only in the LOV, and in 1 subject, reflux was noted predominantly in the ROV. No significant relationship between the presence of an ROV that drained into the right renal vein and pelvic varices was noted. Conclusion: Although right-sided pelvic varices associated with right ovarian vein drainage variations are rare, anatomic variations of the right ovarian vein are not. This study did not find an association between the presence of right ovarian vein and pelvic varices.

Acute paraumbilical vein recanalization: an unusual complication of acute pancreatitis

Directory of Open Access Journals (Sweden)

R J Foster

2015-04-01

Full Text Available Acute pancreatitis is associated with a number of well-known complications and imaging findings. Spontaneous recanalization of the paraumbilical veins as a consequence of pancreatitis in a patient with an otherwise normal liver is, however, a rare entity. This case report depicts this unusual complication as a consequence of gallstone pancreatitis in a patient with a non-cirrhotic liver and no clinical or radiological evidence of portal hypertension. There was recanalization of the paraumbilical veins followed by thrombosis, which is believed to have propagated in a retrograde fashion into distal branches of the otherwise patent portal vein. A literature search for similar cases such as this has yielded no results. Although rare, clinicians and radiologists alike need to be aware of this finding. This case discussion highlights the embryology and anatomy of the paraumbilical veins, as well as discusses the management of paraumbilical and portal vein thrombosis.

Finger Vein Recognition Using Optimal Partitioning Uniform Rotation Invariant LBP Descriptor

Directory of Open Access Journals (Sweden)

Bang Chao Liu

2016-01-01

Full Text Available As a promising biometric system, finger vein identification has been studied widely and many relevant researches have been proposed. However, it is hard to extract a satisfied finger vein pattern due to the various vein thickness, illumination, low contrast region, and noise existing. And most of the feature extraction algorithms rely on high-quality finger vein database and take a long time for a large dimensional feature vector. In this paper, we proposed two block selection methods which are based on the estimate of the amount of information in each block and the contribution of block location by looking at recognition rate of each block position to reduce feature extraction time and matching time. The specific approach is to find out some local finger vein areas with low-quality and noise, which will be useless for feature description. Local binary pattern (LBP descriptors are proposed to extract the finger vein pattern feature. Two finger vein databases are taken to test our algorithm performance. Experimental results show that proposed block selection algorithms can reduce the feature vector dimensionality in a large extent.

Sliding Window-Based Region of Interest Extraction for Finger Vein Images

Science.gov (United States)

Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

2013-01-01

Region of Interest (ROI) extraction is a crucial step in an automatic finger vein recognition system. The aim of ROI extraction is to decide which part of the image is suitable for finger vein feature extraction. This paper proposes a finger vein ROI extraction method which is robust to finger displacement and rotation. First, we determine the middle line of the finger, which will be used to correct the image skew. Then, a sliding window is used to detect the phalangeal joints and further to ascertain the height of ROI. Last, for the corrective image with certain height, we will obtain the ROI by using the internal tangents of finger edges as the left and right boundary. The experimental results show that the proposed method can extract ROI more accurately and effectively compared with other methods, and thus improve the performance of finger vein identification system. Besides, to acquire the high quality finger vein image during the capture process, we propose eight criteria for finger vein capture from different aspects and these criteria should be helpful to some extent for finger vein capture. PMID:23507824

ALPHA visual data collection. STX005-025: melt drop steam explosion experiments

International Nuclear Information System (INIS)

Moriyama, Kiyofumi; Yamano, Norihiro; Maruyama, Yu; Kudo, Tamotsu; Sugimoto, Jun

1999-03-01

Steam explosion is a phenomenon in which a high temperature liquid gives its internal energy to a low temperature volatile liquid extremely quickly causing rapid evaporation and shock wave generation. In the field of nuclear reactor safety research regarding severe accidents in LWRs, steam explosions involving molten fuel and coolant has been recognized as a potential threat to the integrity of the reactor containment vessel. In the ALPHA (Assessment of Loads and Performance of Containment in Hypothetical Accident) program, experiments were performed to investigate the phenomenology of vapor explosions using iron-alumina thermite melt as a simulant of molten core. This report collects the experimental results especially emphasizing the visual observations by high speed photography. (author)

Veias do sistema porta-hepático em gansos domésticos Veins from hepatic portal vein system in domestic geese

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Tatiana C. Santos

2009-04-01

Full Text Available A distribuição intraparenquimal das veias porta-hepáticas foi estudada em 30 gansos domésticos. Latex Neoprene corado foi injetado pela veia isquiática e os animais forma fixados por imersão e injeção intramuscular com formol a 10% e dissecados. O fígado esteve composto por um grande lobo hepático direito e por um lobo hepático esquerdo menor, os quais estiveram conectados por uma ponte de parênquima. O lobo direito do fígado teve exclusivamente vasos do sistema porta-hepático formados pela distribuição intraparenquimal da veia porta-hepática direita, enquanto que no lobo esquerdo estes originaram-se da veia porta-hepática direita e de pequenas veias porta-hepáticas esquerdas. A veia porta-hepática direita emitiu o ramo caudal direito, que emitiu um pequeno ramo caudolateral direito e um grande ramo caudomedial direito. Cranialmente esta veia emitiu os ramos craniais direito e ramos lateral direito. A porção transversa da veia porta-hepática direita cruzou para o lobo hepático esquerdo, emitindo de 1 a 6 pequenos ramos craniais e caudais para a região média do fígado. No lobo esquerdo, o ramo esquerdo da veia porta-hepática direita emitiu o ramo cranial esquerdo, o ramo lateral esquerdo e o ramo medial. De 1 a 6 veias porta-hepáticas esquerdas foram identificadas desembocando ou no ramo esquerdo da veia porta-hepática direita ou em sua porção transversa, oriundos do ventrículo gástrico e do pró-ventrículo. Em 40% dos gansos uma veia porta-hepática própria oriunda da confluência de vasos venosos da face esquerda do ventrículo distribuiu-se na extremidade caudal do lobo esquerdo isoladamente.The intraparenchymal distribution of the hepatic portal veins in 30 domestic geese were studied. Stained Neoprene latex was injected into the isquiatic vessels, and the animals were fixed in 10% formaldehyde by immersion and intramuscular injection. The liver of geese was composed of a large right and a smaller left

Arabidopsis thickvein mutation affects vein thickness and organ vascularization, and resides in a provascular cell-specific spermine synthase involved in vein definition and in polar auxin transport.

Science.gov (United States)

Clay, Nicole K; Nelson, Timothy

2005-06-01

Polar auxin transport has been implicated in the induction of vascular tissue and in the definition of vein positions. Leaves treated with chemical inhibitors of polar auxin transport exhibited vascular phenotypes that include increased vein thickness and vascularization. We describe a recessive mutant, thickvein (tkv), which develops thicker veins in leaves and in inflorescence stems. The increased vein thickness is attributable to an increased number of vascular cells. Mutant plants have smaller leaves and shorter inflorescence stems, and this reduction in organ size and height is accompanied by an increase in organ vascularization, which appears to be attributable to an increase in the recruitment of cells into veins. Furthermore, although floral development is normal, auxin transport in the inflorescence stem is significantly reduced in the mutant, suggesting that the defect in auxin transport is responsible for the vascular phenotypes. In the primary root, the veins appear morphologically normal, but root growth in the tkv mutant is hypersensitive to exogenous cytokinin. The tkv mutation was found to reside in the ACL5 gene, which encodes a spermine synthase and whose expression is specific to provascular cells. We propose that ACL5/TKV is involved in vein definition (defining the boundaries between veins and nonvein regions) and in polar auxin transport, and that polyamines are involved in this process.

Portal Vein Stenting for Portal Biliopathy with Jaundice

Energy Technology Data Exchange (ETDEWEB)

Hyun, Dongho, E-mail: mesentery@naver.com; Park, Kwang Bo, E-mail: kbjh.park@samsung.com [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center (Korea, Republic of); Lim, Seong Joo [Konyang University, Department of Radiology, College of Medicine, Konyang University Hospital (Korea, Republic of); Hwang, Jin Ho [Hallym University Sacred Heart Hospital, Department of Radiology (Korea, Republic of); Sinn, Dong Hyun [Sungkyunkwan University School of Medicine, Department of Medicine, Samsung Medical Center (Korea, Republic of)

2016-04-15

Portal biliopathy refers to obstruction of the bile duct by dilated peri- or para-ductal collateral channels following the main portal vein occlusion from various causes. Surgical shunt operation or endoscopic treatment has been reported. Herein, we report a case of portal biliopathy that was successfully treated by interventional portal vein recanalization.

New therapy strategies for treatment of severe sepsis and septic shock in Intensive care unit of Clinical centre in Kragujevac

Directory of Open Access Journals (Sweden)

Jevđić Jasna

2008-01-01

Full Text Available INTRODUCTION Despite numerous advances in medicine, the mortality rate of severe sepsis and septic shock remains high, 30-50%. New therapy strategies include: early goaldirected therapy, fluid replacement, early and appropriate antimicrobials, source of infection control, use of corticosteroids, vasopressors and inotropic therapy, use of recombinant activated protein C, tight glucose control, low-tidal-volume mechanical ventilation. They have been shown to improve the outcomes. The adequacy and speed of treatment influence the outcome, too. OBJECTIVE The objective was to evaluate if new therapy strategies had been integrated in our routine practice. METOD Patients with severe sepsis or septic shock, who were treated in the Intensive Care Unit (ICU over a ten-month period, were analyzed retrospectively. The descriptive epidemiological method was applied. Central venous catheterization, central venous pressure, antibiotics, fluid resuscitation, mechanical ventilation, vasopressors, corticosteroids, blood administration, deep vein thrombosis prophylaxis, stress ulcer prophylaxis, glucose control, were evaluated. RESULTS 27 patients were analyzed. Patient characteristics were: age, 49.9 years (18-77 with 30-day in-hospital mortality rate of 48.1%. All patients received broad-spectrum antibiotics. Blood cultures were obtained in 85.2% patients. Adequate antimicrobial treatment was applied to 59.3% and 74.1% patients had central venous pressure monitoring. Average central venous pressure was 8.47±5.6 mm Hg (-2- 20. Aggressive fluid therapy was given to 33.3% of the cases and 66.7% of the patients with septic shock received vasoactive drugs while 29.6% received corticosteroids. Red blood cell transfusions were applied in 59.3% of patients. All patients received stress ulcer prophylaxis, and 37% of them deep vein thrombosis prophylaxis. The average value of morning glucose was 9.11±5.03 mmol/l (3.7-22.0. 63% of patients were mechanically ventilated

Near-infrared image formation and processing for the extraction of hand veins

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Bouzida, Nabila; Hakim Bendada, Abdel; Maldague, Xavier P.

2010-10-01

The main objective of this work is to extract the hand vein network using a non-invasive technique in the near-infrared region (NIR). The visualization of the veins is based on a relevant feature of the blood in relation with certain wavelengths of the electromagnetic spectrum. In the present paper, we first introduce the image formation in the NIR spectral band. Then, the acquisition system will be presented as well as the method used for the image processing in order to extract the vein signature. Extractions of this pattern on the finger, on the wrist and on the dorsal hand are achieved after exposing the hand to an optical stimulation by reflection or transmission of light. We present meaningful results of the extracted vein pattern demonstrating the utility of the method for a clinical application like the diagnosis of vein disease, of primitive varicose vein and also for applications in vein biometrics.

Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

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Mizandari, Malkhaz [High Technology Medical Center, Tbilisi State Medical University (Georgia); Ao, Guokun [The 309 Hospital of People' s Liberation Army, Department on Oncology (China); Zhang Yaojun; Feng Xi [Imperial College London, Department of Surgery and Cancer (United Kingdom); Shen Qiang [The First Minimally Invasive Department of Eastern Hepatobiliary Surgery Hospital (China); Chen Minshan [Cancer Centre of Sun Yat-Sen University, Department of Hepatobiliary Surgery (China); Lau, Wan Yee [Chinese University of Hong Kong, Department of Surgery, Faculty of Medicine (Hong Kong); Nicholls, Joanna; Jiao Long; Habib, Nagy, E-mail: nagy.habib@imperial.ac.uk [Imperial College London, Department of Surgery and Cancer (United Kingdom)

2013-02-15

We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus. There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.

The color Doppler ultrasonography in in the diagnosis of deep vein thrombosis

International Nuclear Information System (INIS)

Ameneiro Perez, Santiago; Alvarez Sanchez, Jose A.; Rodriguez Villalonga, Luis; Borras Migues, Marisela; Quinnones Castro, Mayda

2004-01-01

The paper was aimed at evaluating the accuracy of color Doppler ultrasonography, a noninvasive method, in the diagnosis of deep vein thrombosis of the lower limbs, comparing it to the results of the cruel and costly diagnostic g olden rule , that is, phlebography. Methods: Color Doppler ultrasonography served to assess 102 patients clinically suspected of deep vein thrombosis of the lower limbs, taking into account the following criteria: vein compressibility, echographic images, color, Vein Doppler signal modulation after several maneuvers and distal compression. Sensitivity, specificity, positive and negative predictive values and diagnostic efficacy were estimated for each criteria, taking the phlebography as a reference. Results: Total or partial lack of vein compressibility combined with the vein flow evaluation is the ultrasonographic criterion that reveals higher degree of sensitivity, specificity and efficacy (0,98; 0,95 and 0,97 respectively. Color Doppler ultrasonography is a highly effective noninvasive diagnostic method that detects deep vein thrombosis in proximal areas of the lower limbs

Endovascular vein harvest: systemic carbon dioxide absorption.

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Maslow, Andrew M; Schwartz, Carl S; Bert, Arthur; Hurlburt, Peter; Gough, Jeffrey; Stearns, Gary; Singh, Arun K

2006-06-01

Endovascular vein harvest (EDVH) requires CO(2) insufflation to expand the subcutaneous space, allowing visualization and dissection of the saphenous vein. The purpose of this study was to assess the extent of CO(2) absorption during EDVH. Prospective observational study. Single tertiary care hospital. Sixty patients (30 EDVH and 30 open-vein harvest) undergoing isolated coronary artery bypass graft surgery. Hemodynamic, procedural, and laboratory data were collected prior to (baseline), during, and at it the conclusion (final) of vein harvesting. Data were also collected during cardiopulmonary bypass (CPB). Data were compared by using t tests, analysis of variance, and correlation statistics when needed. There were significant increases in arterial CO(2) (PaCO(2), 35%) and decreases in pH (1.35%) during EDVH. These were associated with increases in heart rate, mean blood pressure, and cardiac output. Within the EDVH group, greater elevations (>10 mmHg) in PaCO2 were more likely during difficult harvest procedures, and these patients exhibited greater increase in heart rate. Elevated CO(2) persisted during CPB, requiring higher systemic gas flows and greater use of phenylephrine to maintain desired hemodynamics. EDVH was associated with systemic absorption of CO(2). Greater absorption was more likely in difficult procedures and was associated with greater hemodynamic changes requiring medical therapy.

The Microwave Properties of Simulated Melting Precipitation Particles: Sensitivity to Initial Melting

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Johnson, B. T.; Olson, W. S.; Skofronick-Jackson, G.

2016-01-01

A simplified approach is presented for assessing the microwave response to the initial melting of realistically shaped ice particles. This paper is divided into two parts: (1) a description of the Single Particle Melting Model (SPMM), a heuristic melting simulation for ice-phase precipitation particles of any shape or size (SPMM is applied to two simulated aggregate snow particles, simulating melting up to 0.15 melt fraction by mass), and (2) the computation of the single-particle microwave scattering and extinction properties of these hydrometeors, using the discrete dipole approximation (via DDSCAT), at the following selected frequencies: 13.4, 35.6, and 94.0GHz for radar applications and 89, 165.0, and 183.31GHz for radiometer applications. These selected frequencies are consistent with current microwave remote-sensing platforms, such as CloudSat and the Global Precipitation Measurement (GPM) mission. Comparisons with calculations using variable-density spheres indicate significant deviations in scattering and extinction properties throughout the initial range of melting (liquid volume fractions less than 0.15). Integration of the single-particle properties over an exponential particle size distribution provides additional insight into idealized radar reflectivity and passive microwave brightness temperature sensitivity to variations in size/mass, shape, melt fraction, and particle orientation.

Varicography in the preoperative evaluation of primary varicose veins

International Nuclear Information System (INIS)

Pinzani, A.; Paoli, G.; Gongolo, A.; Spreafico, G.

1989-01-01

Primary varicose veins in the lower limb are usually well evaluated by the surgeon, who avails himself of tornequet tests and Doppler US. However, the operation is often followed by failure or recurrence, or else it requires ugly skin dissection to eradicate an unforeseeably complicated varicose vein. The authors suggest that, whenever the surgeon considers the information obtained with tests and Doppler US inadequate for planning surgery, varicography be performed to get further morphological (and functional) data about the origin of varicose veins, which is of fundamental importance for an accurate surgical planning (crossectomy, stripping, ligation, sclerosis). Out of 100 varicographies consecutively carried out on patients in whom clinical examination was not conclusive, 62% allowed an already planned surgical approach to be changed. The figure rose to 100% in the case of unusual varicose veins. Such a results allowed the needs of both the surgeon (selectivity, effectiveness, radicality) and the patients (narrow scars, absence of relapse) to be respected. Furthermore, it has been pointed out that some vein segments are often only pathological, and they are to be adequately treated, while others can be undamaged, and they are to be preserved for both their function and an eventual by-pass surgery. Varicography is rapidly performed, without complication, and is well accepted by the patients. It is a fundamental help in the preoperative study of primary varicose veins, especially in case of unusual ones, whenever the surgeon is in the slightest diagnostic - and therefore surgical - doubt

Palm-vein classification based on principal orientation features.

Directory of Open Access Journals (Sweden)

Yujia Zhou

Full Text Available Personal recognition using palm-vein patterns has emerged as a promising alternative for human recognition because of its uniqueness, stability, live body identification, flexibility, and difficulty to cheat. With the expanding application of palm-vein pattern recognition, the corresponding growth of the database has resulted in a long response time. To shorten the response time of identification, this paper proposes a simple and useful classification for palm-vein identification based on principal direction features. In the registration process, the Gaussian-Radon transform is adopted to extract the orientation matrix and then compute the principal direction of a palm-vein image based on the orientation matrix. The database can be classified into six bins based on the value of the principal direction. In the identification process, the principal direction of the test sample is first extracted to ascertain the corresponding bin. One-by-one matching with the training samples is then performed in the bin. To improve recognition efficiency while maintaining better recognition accuracy, two neighborhood bins of the corresponding bin are continuously searched to identify the input palm-vein image. Evaluation experiments are conducted on three different databases, namely, PolyU, CASIA, and the database of this study. Experimental results show that the searching range of one test sample in PolyU, CASIA and our database by the proposed method for palm-vein identification can be reduced to 14.29%, 14.50%, and 14.28%, with retrieval accuracy of 96.67%, 96.00%, and 97.71%, respectively. With 10,000 training samples in the database, the execution time of the identification process by the traditional method is 18.56 s, while that by the proposed approach is 3.16 s. The experimental results confirm that the proposed approach is more efficient than the traditional method, especially for a large database.

DEPENDENCY OF SULFATE SOLUBILITY ON MELT COMPOSITION AND MELT POLYMERIZATION

International Nuclear Information System (INIS)

JANTZEN, CAROL M.

2004-01-01

Sulfate and sulfate salts are not very soluble in borosilicate waste glass. When sulfate is present in excess it can form water soluble secondary phases and/or a molten salt layer (gall) on the melt pool surface which is purported to cause steam explosions in slurry fed melters. Therefore, sulfate can impact glass durability while formation of a molten salt layer on the melt pool can impact processing. Sulfate solubility has been shown to be compositionally dependent in various studies, (e.g. , B2O3, Li2O, CaO, MgO, Na2O, and Fe2O3 were shown to increase sulfate solubility while Al2O3 and SiO2 decreased sulfate solubility). This compositional dependency is shown to be related to the calculated melt viscosity at various temperatures and hence the melt polymerization

The umbilical and paraumbilical veins of man.

OpenAIRE

Martin, B F; Tudor, R G

1980-01-01

During its transit through the umbilicus structural changes occur in the thick wall of the extra-abdominal segment of the umbilical vein whereby the components of the intra-abdominal segment acquire an essentially longitudinal direction and become arranged in fibro-elastic and fibro-muscular zones. The vein lumen becomes largely obliterated by asymmetrical proliferation of loose subendothelial conective tissue. The latter forms a new inner zone within which a small segment of the lumen persis...

Aneurysmal malformation of the extrahepatic portal vein: a case report

International Nuclear Information System (INIS)

Lee, Jeong Min; Kang, Sung Soo; Kim, Chong Soo; Han, Hyeun Young

1999-01-01

Aneurysmal malformation of the portal vein is a rare entity. To our knowledge, only scattered reports of portal vein aneurysms appear in the literature in English, and there is no previously published report in Korean. We describe a case exhibiting aneurysmal malformation of the extrahepatic portal vein at the hepatic hilum ; the findings demonstrated by ultrasound, CT and angiography are discussed, a review of previously described cases is included

Congenital vascular malformations: the persistence of marginal and embryonal veins.

Science.gov (United States)

Weber, J; Daffinger, N

2006-05-01

In about 18% of cases with conginental vascular malformations we find a perspective of an atypical truncular vein, located along the outside of the leg, frequently extended from the dorsal foot up to the bottom. In presence of a normally developed system of the deep collecting veins of the lower limb and within the pelvic outflow we are talking about a persisting marginal vein (MV). Hypoplasia or even aplasia of the main deep veins in contrary defines the persisting embryonal vein (EV). Already in childhood these truncular dysplastic veins tend to develop varicose enlargement, causing severe reflux of a huge volume of blood--even more when being associated with av-fistulas (46%). In consequence a rapidly growing chronic venous insufficiency will guide to additional injuries. We have analysed 97 patients showing a persisting MV (n: 92 ) within a total of 102 legs. A persistent embryonal vein (EV) was seen 10 times within this clientel. The persisting truncular veins, associated with phlebectasias and typical clinical symptoms have been examined in a diagnostic "step-by-step" procedure, mainly phlebographically (ascending leg phlebography and varicography), including direct venous blood pressure measurements (phlebodynamometry) and--if needed--by arteriography, showing av-shunting fistulae in 46% of cases. CT and MRI were consulted for the exact therapy planing (frequently initially offered as a non-invasive, however, inadequate key of diagnostic). Actually now these techniques cannot replace pre-operatively the angiographic imaging techniques. The analysis of clinical, morphologic and functional signs, guiding to a specific therapy-relevant classification of MV's and EV's will be presented. And a specific strategy of surgical repair, interventional treatment of av-fistulas and conservative compressive follow-up treatment attempting palliative recompensation of the diseased venous outflow will be discussed also.

Is guidewire exchange a better approach for subclavian vein re-catheterization for chronic hemodialysis patients?

Science.gov (United States)

Hou, Shaw-Min; Chou, Po-Ching; Huang, Chi-Hung; Chin, Chih-Hui; Wang, Pa-Chun; Chen, Ya-Hui

2006-01-01

The objectives of this study were to compare outcomes and survival rates of subclavian vein re-catheterization through guide wire exchange (GWE) or de novo insertion (DN). The study was conducted in a retrospective manner. Medical records of 36 patients who received percutaneous subclavian vein re-catheterization for hemodialysis in our institution during the period from April 1, 2001 to September 30, 2004 were reviewed. All patients had at least 2 catheter insertions records in our institute. Incidences of adverse events (infection, thrombosis) were compared between GWE and DN groups using x2 test. Predictors for adverse event occurrences were analyzed using logistic regression models. Cox proportional hazard model was used to investigate the predictors for adverse event-free catheter days. Kaplan-Meire survival curves were computed and compared using log rank test. Information were generated from 98 catheters (41 from DN, 57 from GWE groups). The average catheter usage was 2.8+/-0.9 devices per patient and the mean catheter-indwelling-day was 125.4+/-129.5 days in this cohort. We found GWE group had significantly lower thrombosis rate (49.1% vs. 85.4% for DN group, Prates for GWE were > or =30 days, 85.4%; > or =60 days, 75.5%; > or =90 days, 64.5%; > or =180 days, 44.3%. The actuarial survival rates for DN were > or =30 days, 70.7%; > or =60 days, 58.5%; > or =90 days, 34.2%; > or =180 days, 18.4%. GWE group catheters had significantly higher catheter survival rates (P=0.0009). Mahukar catheter (hazard ratio 0.514, P=0.03), non-shock (hazard ratio 3.358, P=0.04), and older age (hazard ratio 0.958, P=0.026) were predictors of adverse event-free remaining catheter days. We suggest that GWE might be a favorable option over DN insertion when revised subclavian vein catheterization is inevitable. GWE can be performed repeatedly without compromising catheter outcomes.

Contralateral Deep Vein Thrombosis after Iliac Vein Stent Placement in Patients with May-Thurner Syndrome.

Science.gov (United States)

Le, Trong Binh; Lee, Taeg Ki; Park, Keun-Myoung; Jeon, Yong Sun; Hong, Kee Chun; Cho, Soon Gu

2018-04-25

To investigate the incidence and potential causes of contralateral deep vein thrombosis (DVT) after common iliac vein (CIV) stent placement in patients with May-Thurner syndrome (MTS). Data of 111 patients (women: 73%) who had CIV stent implantation for symptomatic MTS at a single center were retrospectively analyzed. Mean patient age was 63.1 ± 15.2 years. Median follow-up was 36 months (range, 1-142 months). Stent location was determined by venogram and classified as extended to the inferior vena cava (IVC), covered the confluence, or confined to the iliac vein. Potential causes of contralateral DVT were presumed based on venographic findings. The relationship between stent location and contralateral DVT was analyzed. Ten patients (9%, men/women: 4/6) exhibited contralateral DVT at a median timing of 40 months (range, 6-98 months). Median age was 69 years (range, 42-85 years). Median follow-up was 73.5 months (range, 20-134 months). Potential causes were venous intimal hyperplasia (VIH) (n = 7), "jailing" (n = 2), and indeterminate (n = 1). All patients with VIH had previous CIV stents overextended to the IVC. Overextension of CIV stent was associated with contralateral DVT (P VIH should be considered a potential cause. Copyright © 2018 SIR. Published by Elsevier Inc. All rights reserved.

Morphology of congenital portosystemic shunts involving the left colic vein in dogs and cats.

Science.gov (United States)

White, R N; Parry, A T

2016-05-01

To describe the anatomy of congenital portosystemic shunts involving the left colic vein in dogs and cats. Retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. For inclusion a shunt involving the left colic vein with recorded intraoperative mesenteric portovenography or computed tomography angiography along with direct gross surgical observations at the time of surgery was required. Six dogs and three cats met the inclusion criteria. All cases had a shunt which involved a distended left colic vein. The final communication with a systemic vein was variable; in seven cases (five dogs, two cats) it was via the caudal vena cava, in one cat it was via the common iliac vein and in the remaining dog it was via the internal iliac vein. In addition, two cats showed caudal vena cava duplication. The morphology of this shunt type appeared to be a result of an abnormal communication between either the left colic vein or the cranial rectal vein and a pelvic systemic vein (caudal vena cava, common iliac vein or internal iliac vein). This information may help with surgical planning in cases undergoing shunt closure surgery. © 2016 British Small Animal Veterinary Association.

Effects of Atwood number on shock focusing in shock-cylinder interaction

Science.gov (United States)

Ou, Junfeng; Ding, Juchun; Luo, Xisheng; Zhai, Zhigang

2018-02-01

The evolution of shock-accelerated heavy-gas cylinder surrounded by the air with different Atwood numbers (A_t=0.28, 0.50, 0.63) is investigated, concentrating on shock focusing and jet formation. Experimentally, a soap film technique is used to generate an ideal two-dimensional discontinuous gas cylinder with a clear surface, which can guarantee the observation of shock wave movements inside the cylinder. Different Atwood numbers are realized by different mixing ratios of SF_6 and air inside the cylinder. A high-speed schlieren system is adopted to capture the shock motions and jet morphology. Numerical simulations are also performed to provide more information. The results indicate that an inward jet is formed for low Atwood numbers, while an outward jet is generated for high Atwood numbers. Different Atwood numbers will lead to the differences in the relative velocities between the incident shock and the refraction shock, which ultimately results in the differences in shock competition near the downstream pole. The morphology and feature of the jet are closely associated with the position and intensity of shock focusing. The pressure and vorticity contours indicate that the jet formation should be attributed to the pressure pulsation caused by shock focusing, and the jet development is ascribed to the vorticity induction. Finally, a time ratio proposed in the previous work for determining the shock-focusing type is verified by experiments.

Plantar vein thrombosis: a rare cause of plantar foot pain

International Nuclear Information System (INIS)

Siegal, Daniel S.; Wu, Jim S.; Brennan, Darren D.; Hochman, Mary G.; Challies, Tracy

2008-01-01

Plantar vein thrombosis is a rare condition, with only a handful of cases reported in the literature. The cause is unknown; however, the disease has been attributed to prior surgery, trauma, and paraneoplastic conditions. We present a case of a 32-year-old female runner with plantar vein thrombosis diagnosed on contrast-enhanced MRI and confirmed on ultrasound. The symptoms resolved with conservative treatment and evaluation revealed the presence of a prothrombin gene mutation and use of oral contraceptive pills. To our knowledge, this is the first case of plantar vein thrombosis diagnosed initially by MRI. Moreover, this case suggests that plantar vein thrombosis should be considered in patients with hypercoagulable states and plantar foot pain. (orig.)

Plantar vein thrombosis: a rare cause of plantar foot pain

Energy Technology Data Exchange (ETDEWEB)

Siegal, Daniel S.; Wu, Jim S.; Brennan, Darren D.; Hochman, Mary G. [Beth Israel Deaconess Medical Center, Department of Radiology, Boston, MA (United States); Challies, Tracy [Beth Israel Deaconess Medical Center, Department of Pathology, Boston, MA (United States)

2008-03-15

Plantar vein thrombosis is a rare condition, with only a handful of cases reported in the literature. The cause is unknown; however, the disease has been attributed to prior surgery, trauma, and paraneoplastic conditions. We present a case of a 32-year-old female runner with plantar vein thrombosis diagnosed on contrast-enhanced MRI and confirmed on ultrasound. The symptoms resolved with conservative treatment and evaluation revealed the presence of a prothrombin gene mutation and use of oral contraceptive pills. To our knowledge, this is the first case of plantar vein thrombosis diagnosed initially by MRI. Moreover, this case suggests that plantar vein thrombosis should be considered in patients with hypercoagulable states and plantar foot pain. (orig.)

Shock parameter calculations at weak interplanetary shock waves

Directory of Open Access Journals (Sweden)

J. M. Gloag

2005-02-01

Full Text Available A large set of interplanetary shock waves observed using the Ulysses spacecraft is analysed in order to determine their local parameters. For the first time a detailed analysis is extended to the thermodynamic properties of a large number of events. The intention is to relate the shock parameters to the requirements set by MHD shock theory. A uniform approach is adopted in the selection of up and downstream regions for this analysis and applied to all the shock waves. Initially, the general case of a 3 component adiabatic plasma is considered. However, the calculation of magnetosonic and Alfvénic Mach numbers and the ratio of downstream to upstream entropy produce some unexpected results. In some cases there is no clear increase in entropy across the shock and also the magnetosonic Mach number can be less than 1. It is found that a more discerning use of data along with an empirical value for the polytropic index can raise the distribution of downstream to upstream entropy ratios to a more acceptable level. However, it is also realised that many of these shocks are at the very weakest end of the spectrum and associated phenomena may also contribute to the explanation of these results.

Enhancing the bioavailability of magnolol in rabbits using melting solid dispersion with polyvinylpyrrolidone.

Science.gov (United States)

Lin, Shiuan-Pey; Hou, Yu-Chi; Liao, Tzu-Yun; Tsai, Shang-Yuan

2014-03-01

Preparation of magnolol-loaded amorphous solid dispersion was investigated for improving the bioavailability. A solid dispersion of magnolol was prepared with polyvinylpyrrolidone K-30 (PVP) by melting method, and the physical properties were characterized by using differential scanning calorimetry, powder X-ray diffractometry, Fourier transformation-infrared spectroscopy and scanning electron microscope. In addition, dissolution test was also performed. Subsequently, the bioavailability of magnolol pure compound, its physical mixture and solid dispersion were compared in rabbits. The blood samples withdrawn via marginal ear vein at specific time points were assayed by HPLC method. Oral administration of the solid dispersion of magnolol with PVP significantly increased the systemic exposures of magnolol and magnolol sulfates/glucuronides by 80.1% and 142.8%, respectively, compared to those given with magnolol pure compound. Magnolol-loaded amorphous solid dispersion with PVP has demonstrated enhanced bioavailability of magnolol in rabbits.

Persistent Left Superior Vena Cava Associated with Hemiazygos Vein Draining in It and Absence of Left Brachiocephalic Vein, in a Patient with Congenital Heart Defect

Directory of Open Access Journals (Sweden)

Opincariu Diana

2016-09-01

Full Text Available Persistent left superior vena cava is an anomalous vein that derives from a malfunction of obliteration of the left common cardinal vein during intrauterine life. The diagnosis can be suggested by a dilated coronary sinus as seen in echocardiography, or other imagistic methods. Due to the lack of hemodynamic impairment, and consequently with few or no symptoms, this vascular anomaly is frequently discovered incidentally. In this brief report we present the case of a 35-year-old male known with a complex congenital cardiovascular malformation that included atrial septum defect, persistent left superior vena cava and anomalous right pulmonary vein drainage in the PLSVC, diagnosed with sinoatrial block that required pacemaker implantation. Due to the patient’s medical history, investigations to decide the best approach needed for pacemaker implantation were performed, including a thoracic CT that incidentally found additional anomalies — the hemiazygos vein draining in PLSVC and the lack of the left brachiocephalic vein.

Shock pressure estimation in basement rocks of the Chicxulub impact crater using cathodoluminescence spectroscopy of quartz

Science.gov (United States)

Tomioka, N.; Tani, R.; Kayama, M.; Chang, Y.; Nishido, H.; Kaushik, D.; Rae, A.; Ferrière, L.; Gulick, S. P. S.; Morgan, J. V.

2017-12-01

The Chicxulub impact structure, located in the northern Yucatan Peninsula, Mexico, was drilled by the joint IODP-ICDP Expedition 364 in April-May 2016. This expedition is the first attempt to obtain materials from the topographic peak ring within the crater previously identified by seismic imaging. A continuous core was successfully recovered from the peak ring at depths between 505.7 and 1334.7 mbsf. Uplifted, fractured, and shocked granitic basement rocks forming the peak ring were found below, in the impact breccia and impact melt rock unit (747.0-1334.7 mbsf; Morgan et al. 2016). In order to constrain impact crater formation, we investigated shock pressure distribution in the peak-ring basement rocks. Thin sections of the granitic rocks were prepared at intervals of 60 m. All the samples contains shocked minerals, with quartz grains frequently showing planar deformation features (PDFs). We determined shock pressures based on the cathodoluminescence (CL) spectroscopy of quartz. The strong advantage of the CL method is its applicability to shock pressure estimation for individual grains for both quartz and diaplectic SiO2 glass with high-spatial resolution ( 1 μm) (Chang et al. 2016). CL spectra of quartz shows a blue emission band caused by shock-induced defect centers, where its intensity increases with shock pressure. A total of 108 quartz grains in ten thin sections were analyzed using a scanning electron microscope with a CL spectrometer attached (an acceleration voltage of 15 kV and a beam current of 2 nA were used). Natural quartz single crystals, which were experimentally shocked at 0-30 GPa, were used for pressure calibration. CL spectra of all the quartz grains in the basement rocks showed broad blue emission band at the wavelength range of 300-500 nm and estimated shock pressures were in the range of 15-20 GPa. The result is consistent with values obtained from PDFs analysis in quartz using the universal stage (Ferrière et al. 2017; Rae et al. 2017

Collateral veins in inferior caval vein occlusion demonstrated via CT

International Nuclear Information System (INIS)

Lien, H.H.; Lund, G.

1983-01-01

CT-scans of 12 patients with tumour-induced occlusion of the inferior vena cava were studied with regard to collateral veins. A comparison was performed with findings at phlebography in 10 patients and at autopsy in 2. The site and appearance of the main collateral pathway are presented. A close study of vascular structures renders useful information on collateral circulation in occlusion of the inferior vena cava. (orig.)

Mass-velocity and size-velocity distributions of ejecta cloud from shock-loaded tin surface using atomistic simulations

Energy Technology Data Exchange (ETDEWEB)

Durand, O.; Soulard, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

2015-04-28

The mass (volume and areal densities) versus velocity as well as the size versus velocity distributions of a shock-induced cloud of particles are investigated using large scale molecular dynamics simulations. A generic three-dimensional tin crystal with a sinusoidal free surface roughness (single wavelength) is set in contact with vacuum and shock-loaded so that it melts directly on shock. At the reflection of the shock wave onto the perturbations of the free surface, two-dimensional sheets/jets of liquid metal are ejected. The simulations show that the distributions may be described by an analytical model based on the propagation of a fragmentation zone, from the tip of the sheets to the free surface, in which the kinetic energy of the atoms decreases as this zone comes closer to the free surface on late times. As this kinetic energy drives (i) the (self-similar) expansion of the zone once it has broken away from the sheet and (ii) the average size of the particles which result from fragmentation in the zone, the ejected mass and the average size of the particles progressively increase in the cloud as fragmentation occurs closer to the free surface. Though relative to nanometric scales, our model may help in the analysis of experimental profiles.

Shock Mechanism Analysis and Simulation of High-Power Hydraulic Shock Wave Simulator

Directory of Open Access Journals (Sweden)

Xiaoqiu Xu

2017-01-01

Full Text Available The simulation of regular shock wave (e.g., half-sine can be achieved by the traditional rubber shock simulator, but the practical high-power shock wave characterized by steep prepeak and gentle postpeak is hard to be realized by the same. To tackle this disadvantage, a novel high-power hydraulic shock wave simulator based on the live firing muzzle shock principle was proposed in the current work. The influence of the typical shock characteristic parameters on the shock force wave was investigated via both theoretical deduction and software simulation. According to the obtained data compared with the results, in fact, it can be concluded that the developed hydraulic shock wave simulator can be applied to simulate the real condition of the shocking system. Further, the similarity evaluation of shock wave simulation was achieved based on the curvature distance, and the results stated that the simulation method was reasonable and the structural optimization based on software simulation is also beneficial to the increase of efficiency. Finally, the combination of theoretical analysis and simulation for the development of artillery recoil tester is a comprehensive approach in the design and structure optimization of the recoil system.

Arabidopsis thickvein Mutation Affects Vein Thickness and Organ Vascularization, and Resides in a Provascular Cell-Specific Spermine Synthase Involved in Vein Definition and in Polar Auxin Transport1

Science.gov (United States)

Clay, Nicole K.; Nelson, Timothy

2005-01-01

Polar auxin transport has been implicated in the induction of vascular tissue and in the definition of vein positions. Leaves treated with chemical inhibitors of polar auxin transport exhibited vascular phenotypes that include increased vein thickness and vascularization. We describe a recessive mutant, thickvein (tkv), which develops thicker veins in leaves and in inflorescence stems. The increased vein thickness is attributable to an increased number of vascular cells. Mutant plants have smaller leaves and shorter inflorescence stems, and this reduction in organ size and height is accompanied by an increase in organ vascularization, which appears to be attributable to an increase in the recruitment of cells into veins. Furthermore, although floral development is normal, auxin transport in the inflorescence stem is significantly reduced in the mutant, suggesting that the defect in auxin transport is responsible for the vascular phenotypes. In the primary root, the veins appear morphologically normal, but root growth in the tkv mutant is hypersensitive to exogenous cytokinin. The tkv mutation was found to reside in the ACL5 gene, which encodes a spermine synthase and whose expression is specific to provascular cells. We propose that ACL5/TKV is involved in vein definition (defining the boundaries between veins and nonvein regions) and in polar auxin transport, and that polyamines are involved in this process. PMID:15894745

Characterizing the nature of melt-rock reaction in peridotites from the Santa Elena Ophiolite, NW Costa Rica

Science.gov (United States)

Carr, D.; Loocke, M. P.; Snow, J. E.; Gazel, E.

2017-12-01

The Santa Elena Ophiolite (SEO), located on the northwestern coast of Costa Rica, consists primarily of preserved oceanic mantle and crustal rocks thrust above an accretionary complex. The SEO is predominantly characterized by mantle peridotites (i.e., primarily spinel lherzolite with minor amounts of harzburgite and dunite) cut and intruded by minor pegmatitic gabbros, layered gabbros, plagiogranites, and doleritic and basaltic dykes. Previous studies have concluded that the complex formed in a suprasubduction zone (SSZ) setting based on the geochemical nature of the layered gabbros and plagiogranites (i.e., depleted LREE and HFSE and enriched LILE and Pb), as well, as the peridotites (i.e., low-TiO2, Zr, and V, and high MgO, Cr, and Ni)(Denyer and Gazel, 2009). Eighteen ultramafic samples collected during the winter 2010/2011 field season (SECR11) exhibit abundant evidence for melt-rock reaction (e.g., disseminated plagioclase and plagioclase-spinel, clinopyroxene-spinel, and plagioclase-clinopyroxene symplectites) and provide a unique opportunity to characterize the textural and chemical nature of melt-rock reaction in the SEO. We present the results of a petrologic investigation (i.e., petrography and electron probe microanalysis) of 28 thin sections (19 spinel lherzolites, of which 14 are plagioclase-bearing, 4 pyroxenite veins, and 5 harzburgites) derived from the SECR11 sample set. The results of this investigation have the potential to better our understanding of the nature of melt generation and migration and melt-rock interaction in the SEO mantle section and shed further light on the complex petrogenetic history of the SEO. Denyer, P., Gazel, E., 2009, Journal of South American Earth Sciences, 28:429-442.

Iliac vein stenosis is an underdiagnosed cause of pelvic venous insufficiency.

Science.gov (United States)

Santoshi, Ratnam K N; Lakhanpal, Sanjiv; Satwah, Vinay; Lakhanpal, Gaurav; Malone, Michael; Pappas, Peter J

2018-03-01

Reflux in the ovarian veins, with or without an obstructive venous outflow component, is reported to be the primary cause of pelvic venous insufficiency (PVI). The degree to which venous outflow obstruction plays a role in PVI is currently ill-defined. We retrospectively reviewed the charts of 227 women with PVI who presented to the Center for Vascular Medicine from January 2012 to September 2015. Assessments and interventions consisted of an evaluation for other causes of chronic pelvic pain by a gynecologist; preintervention and postintervention visual analog scale (VAS) pain score; complete venous duplex ultrasound examination; and Clinical, Etiology, Anatomy, and Pathophysiology classification. All patients underwent diagnostic venography of their pelvic and left ovarian veins as well as intravascular ultrasound of their iliac veins. Patients were treated in one of six ways: ovarian vein embolization (OVE) alone (chemical ± coils), OVE with staged iliac vein stenting, OVE with simultaneous iliac vein stenting, iliac vein stenting alone, OVE with venoplasty, and venoplasty alone. Of the 227 women treated, the average age and number of pregnancies was 46.4 ± 10.4 years and 3.36 ± 1.99, respectively. Treatment distribution was the following: OVE, n = 39; OVE with staged stenting, n = 94; OVE with simultaneous stenting, n = 33; stenting alone, n = 50; OVE with venoplasty, n = 8; and venoplasty alone, n = 3. Seven patients in the OVE and stenting groups (staged) and one patient in the OVE + venoplasty group required a second embolization of the left ovarian vein. Eighty percent (181/227) of patients demonstrated an iliac stenosis >50% by intravascular ultrasound. Average VAS scores for the entire cohort before and after intervention were 8.45 ± 1.11 and 1.86 ± 1.61 (P ≤ .001). In the staged group, only 9 of 94 patients reported a decrease in the VAS score with OVE alone. VAS score decreased from 8.6 ± 0.89 before OVE to 7.97 ± 2.10 after OVE

Alfven shock trains

International Nuclear Information System (INIS)

Malkov, M.A.; Kennel, C.F.; Wu, C.C.; Pellat, R.; Shapiro, V.D.

1991-01-01

The Cohen--Kulsrud--Burgers equation (CKB) is used to consider the nonlinear evolution of resistive, quasiparallel Alfven waves subject to a long-wavelength, plane-polarized, monochromatic instability. The instability saturates by nonlinear steepening, which proceeds until the periodic waveform develops an interior scale length comparable to the dissipation length; a fast or an intermediate shock then forms. The result is a periodic train of Alfven shocks of one or the other type. For propagation strictly parallel to the magnetic field, there will be two shocks per instability wavelength. Numerical integration of the time-dependent CKB equation shows that an initial, small-amplitude growing wave asymptotes to a stable, periodic stationary wave whose analytic solution specifies how the type of shock embedded in the shock train, and the amplitude and speed of the shock train, depend on the strength and phase of the instability. Waveforms observed upstream of the Earth's bowshock and cometary shocks resemble those calculated here

Melting of contaminated metallic waste

International Nuclear Information System (INIS)

Lee, Y.-S.; Cheng, S.-Y.; Kung, H.-T.; Lin, L.-F.

2004-01-01

Approximately 100 tons of contaminated metallic wastes were produced each year due to maintenance for each TPC's nuclear power reactor and it was roughly estimated that there will be 10,000 tons of metallic scraps resulted from decommissioning of each reactor in the future. One means of handling the contaminated metal is to melt it. Melting process owns not only volume reduction which saves the high cost of final disposal but also resource conservation and recycling benefits. Melting contaminated copper and aluminum scraps in the laboratory scale have been conducted at INER. A total of 546 kg copper condenser tubes with a specific activity of about 2.7 Bq/g was melted in a vacuum induction melting facility. Three types of products, ingot, slag and dust were derived from the melting process, with average activities of 0.10 Bq/g, 2.33 Bq/g and 84.3 Bq/g respectively. After the laboratory melting stage, a pilot plant with a 500 kg induction furnace is being designed to melt the increasingly produced contaminated metallic scraps from nuclear facilities and to investigate the behavior of different radionuclides during melting. (author)

Phosphorus zoning as a recorder of crystal growth kinetics

DEFF Research Database (Denmark)

Baziotis, I.; Asimow, P.D.; Ntaflos, T.

2017-01-01

spectrometry. The petrogenetic history of each vein involves melt intrusion, cooling accompanied by both wall-rock reaction and crystallization, quench of melt to a glass, and possibly later modifications. Exotic secondary olivine crystals in the veins display concentric phosphorus (P)-rich zoning, P...

Dynamics of Melting and Melt Migration as Inferred from Incompatible Trace Element Abundance in Abyssal Peridotites

Science.gov (United States)

Peng, Q.; Liang, Y.

2008-12-01

To better understand the melting processes beneath the mid-ocean ridge, we developed a simple model for trace element fractionation during concurrent melting and melt migration in an upwelling steady-state mantle column. Based on petrologic considerations, we divided the upwelling mantle into two regions: a double- lithology upper region where high permeability dunite channels are embedded in a lherzolite/harzburgite matrix, and a single-lithology lower region that consists of partially molten lherzolite. Melt generated in the single lithology region migrates upward through grain-scale diffuse porous flow, whereas melt in the lherzolite/harzburgite matrix in the double-lithology region is allowed to flow both vertically through the overlying matrix and horizontally into its neighboring dunite channels. There are three key dynamic parameters in our model: degree of melting experienced by the single lithology column (Fd), degree of melting experienced by the double lithology column (F), and a dimensionless melt suction rate (R) that measures the accumulated rate of melt extraction from the matrix to the channel relative to the accumulated rate of matrix melting. In terms of trace element fractionation, upwelling and melting in the single lithology column is equivalent to non-modal batch melting (R = 0), whereas melting and melt migration in the double lithology region is equivalent to a nonlinear combination of non-modal batch and fractional melting (0 abyssal peridotite, we showed, with the help of Monte Carlo simulations, that it is difficult to invert for all three dynamic parameters from a set of incompatible trace element data with confidence. However, given Fd, it is quite possible to constrain F and R from incompatible trace element abundances in residual peridotite. As an illustrative example, we used the simple melting model developed in this study and selected REE and Y abundance in diopside from abyssal peridotites to infer their melting and melt migration

The response of thrombosis in the portal vein or hepatic vein in hepatocellular carcinoma to radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Bae, Bong Kyung; Kim, Jae Chul [Dept. of Radiation Oncology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

2016-09-15

The purpose of current study is to evaluate the response of the patients with portal vein thrombosis (PVT) or hepatic vein thrombosis (HVT) in hepatocellular carcinoma (HCC) treated with three-dimensional conformal radiation therapy (3D-CRT). In addition, survival of patients and potential prognostic factors of the survival was evaluated. Forty-seven patients with PVT or HVT in HCC, referred to our department for radiotherapy, were retrospectively reviewed. For 3D-CRT plans, a gross tumor volume (GTV) was defined as a hypodense filling defect area in the portal vein (PV) or hepatic vein (HV). Survival of patients, and response to radiation therapy (RT) were analyzed. Potential prognostic factors for survival and response to RT were evaluated. The median survival time of 47 patients was 8 months, with 1-year survival rate of 15% and response rate of 40%. Changes in Child-Pugh score, response to RT, Eastern cooperative oncology group performance status (ECOG PS), hepatitis C antibody (HCVAb) positivity, and additional post RT treatment were statistically significant prognostic factors for survival in univariate analysis (p = 0.000, p = 0.018, p = 0.000, p = 0.013, and p = 0.047, respectively). Of these factors, changes in Child-Pugh score, and response to RT were significant for patients' prognosis in multivariate analysis (p = 0.001 and p = 0.035, respectively). RT could constitute a reasonable treatment option for patients with PVT or HVT in HCC with acceptable toxicity. Changes in Child-Pugh score, and response to RT were statistically significant factors of survival of patients.

The risk of varicose veins in standing female workers

Directory of Open Access Journals (Sweden)

Tony Hidayat

2013-07-01

Full Text Available AbstrakLatar belakang:Varises sering terjadi pada karyawan yang harus bekerja dalam posisi kerja berdiri. Tujuan penelitian ini untuk mengetahui beberapa faktor risiko terhadap varises tungkai dan atau kaki di antara pekerja perempuan. Metode:Penelitian potong lintang ini dilakukan pada Januari-Maret 2010. Sampel penelitian yang dipilih secara purposif yang memenuhi kriteria inklusi penelitian di antara pekerja perempuan perlu bekerja dalam  posisi  kerja  berdiri.  Data  dikumpulkan  dengan  wawancara,  pemeriksaan  fisik  dan  observasi posisi kerja berdiri. Pengolahan data untuk menentukan faktor dominan terhadap varises menggunakan pendekatan risiko relatif.Hasil:Dari 152 karyawan yang terdapat 111 yang bersedia mengikuti penelitian, dan yang menderita varises tungkai dan atau kaki sebanyak 52,3% (53 orang. Sebagian besar responden berusia 18-35 tahun, memiliki masa kerja 3-17 tahun, bekerja dalam posisi kerja banyak berdiri. Sebagian kecil responden memiliki riwayat varises di dalam keluarga (13,51%, memakai kontrasepsi oral (11,71%, memiliki kebiasaan olah raga (18,02% dan memakai sepatu hak tinggi (11,71%. Faktor umur, pemakaian kontrasepsi oral, pemakaian sepatu hak tinggi, kebiasaan olah raga, posisi kerja berdiri, tempat kerja, dan masa kerja tidak berhubungan dengan varises tungkai dan atau kaki. Karyawan yang mempunyai dibandingkan dengan yang tidak mempunyai riwayat keluarga varises, berisiko 69% lebih tinggi menderita varises [risiko relatif (RR = 1,69; P = 0.121]. Kesimpulan:Karyawan yang mempunyai riwayat keluarga varises berisiko lebih tinggi menderita varises. (Health Science Indones 2013;1:47-50 Kata kunci:varises, posisi kerja berdiriAbstractBackground: Varicose veins often occur in employees who have to work in a position of standing work. The purpose of this study to determine risk factors for varicose veins and leg or foot among women workers.Methods: In this cross-sectional study in January-March 2010 the

Sound velocity of tantalum under shock compression in the 18–142 GPa range

Energy Technology Data Exchange (ETDEWEB)

Xi, Feng, E-mail: xifeng@caep.cn; Jin, Ke; Cai, Lingcang, E-mail: cai-lingcang@aliyun.com; Geng, Huayun; Tan, Ye; Li, Jun [National Key Laboratory of Shock Waves and Detonation Physics, Institute of Fluid Physics, CAEP, P.O. Box 919-102 Mianyang, Sichuan 621999 (China)

2015-05-14

Dynamic compression experiments of tantalum (Ta) within a shock pressure range from 18–142 GPa were conducted driven by explosive, a two-stage light gas gun, and a powder gun, respectively. The time-resolved Ta/LiF (lithium fluoride) interface velocity profiles were recorded with a displacement interferometer system for any reflector. Sound velocities of Ta were obtained from the peak state time duration measurements with the step-sample technique and the direct-reverse impact technique. The uncertainty of measured sound velocities were analyzed carefully, which suggests that the symmetrical impact method with step-samples is more accurate for sound velocity measurement, and the most important parameter in this type experiment is the accurate sample/window particle velocity profile, especially the accurate peak state time duration. From these carefully analyzed sound velocity data, no evidence of a phase transition was found up to the shock melting pressure of Ta.

Spherical strong-shock generation for shock-ignition inertial fusion

Energy Technology Data Exchange (ETDEWEB)

Theobald, W.; Seka, W.; Lafon, M.; Anderson, K. S.; Hohenberger, M.; Marshall, F. J.; Michel, D. T.; Solodov, A. A.; Stoeckl, C.; Edgell, D. H.; Yaakobi, B.; Shvydky, A. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Nora, R.; Betti, R. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Department of Mechanical Engineering and Department of Physics, University of Rochester, Rochester, New York 14623 (United States); Casner, A.; Reverdin, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Ribeyre, X.; Vallet, A. [Université de Bordeaux-CNRS-CEA, CELIA (Centre Lasers Intenses et Applications) UMR 5107 F-33400 Talence (France); Peebles, J.; Beg, F. N. [University of California, San Diego, La Jolla, California 92093 (United States); and others

2015-05-15

Recent experiments on the Laboratory for Laser Energetics' OMEGA laser have been carried out to produce strong shocks in solid spherical targets with direct laser illumination. The shocks are launched at pressures of several hundred Mbars and reach Gbar upon convergence. The results are relevant to the validation of the shock-ignition scheme and to the development of an OMEGA experimental platform to study material properties at Gbar pressures. The experiments investigate the strength of the ablation pressure and the hot-electron production at incident laser intensities of ∼2 to 6 × 10{sup 15 }W/cm{sup 2} and demonstrate ablation pressures exceeding 300 Mbar, which is crucial to developing a shock-ignition target design for the National Ignition Facility. The timing of the x-ray flash from shock convergence in the center of the solid plastic target is used to infer the ablation and shock pressures. Laser–plasma instabilities produce hot-electrons with a moderate temperature (<100 keV). The instantaneous conversion efficiencies of laser power into hot-electron power reached up to ∼15% in the intensity spike. The large amount of hot electrons is correlated with an earlier x-ray flash and a strong increase in its magnitude. This suggests that hot electrons contribute to the augmentation of the shock strength.

Reverse polarity magnetized melt rocks from the Chicxulub impact structure, Yucatan Peninsula, Mexico

Science.gov (United States)

Urrutia-Fucugauchi, Jaime; Marin, Luis E.; Sharpton, Virgil L.; Quezada, Juan Manuel

1993-03-01

Further paleomagnetic data for core samples of melt rock recovered in the Petroleos Mexicanos (PEMEX) exploratory wells within the Chicxulub structure, northern Yucatan peninsula, Mexico are reported. A previous report by Sharpton showed that the rocks studied contain high iridium levels and shocked breccia clasts, and an Ar-40/Ar-39 age of 65.2 plus or minus 0.4 Ma. The geomagnetic polarity determined for two samples is reverse (R) and was correlated with chron 29R that includes the K/T boundary. Our present analysis is based on two samples from each of three clasts of the melt rock from PEMEX well Y6-N17 (1295 to 1299 m b.s.l.). This study concentrates on the vectorial nature and stability of the remanence (NRM), the magnetic mineralogy and remanence carriers (i.e., the reliability and origin of the record), and on the implications (correlation with expected paleolatitude and polarity). The relative orientation of the drill core samples with respect to the horizontal is known. Samples were stable under alternating field (AF) and thermal treatments, and after removal of a small component they exhibited single-vectorial behavior. The characteristic remanence inclinations show small dispersion and a mean value (-43 deg) in close agreement with the expected inclination and paleolatitude (derived from the North American apparent polar wander path). Isothermal remenence (IRM) acquisition experiments, Lowrie-Fuller tests, coercivity and unblocking temperature spectra of NRM and saturation IRM, susceptibility and Q-coefficient analyses, and the single-component nature indicate a dominant mineralogy of iron-rich titanomagnetites with single or pseduo-single domain states. The stable characteristic magnetization may be interpreted as a result of shock heating of the rock at the time of formation of the inpact structure and its polarity, age, and paleolatitude are consistent with a time about the K/T boundary.

A free vein graft cap influences neuroma formation after nerve transection.

Science.gov (United States)

Galeano, Mariarosaria; Manasseri, Benedetto; Risitano, Giovanni; Geuna, Stefano; Di Scipio, Federica; La Rosa, Paola; Delia, Gabriele; D'Alcontres, Francesco Stagno; Colonna, Michele R

2009-01-01

: Neuroma formation is a major problem in nerve surgery and consensus about its prevention has not been reached. It has been suggested that vein covering can reduce neuroma formation in transected nerves. In this article, the Authors propose an easy and novel method of covering by nerve stump capping with a free vein graft. : Neuroma-like lesions were created on the rat thigh sectioning the femoral nerve above its division in 16 animals. The proximal nerve stump was invaginated into the lumen of a 1.5 cm long femoral free vein graft on the right side, and the vein was closed on itself by microsurgical sutures to form a cap for the nerve stump. On the left side acting as the control neuroma, the nerve was cut and left uncovered. Histological and immunohistochemical assessment was used to quantify the degree of neuroma formation. : Significant differences were found in both neuroma size and axon-glia organization between the treated and control sides indicating that free vein graft capping reduced neuroma formation in comparison to uncovered nerve stumps. : Our results confirm that vein-covering of a transected nerve stump can be effective in reducing neuroma formation. Moreover, unlike previous works that buried the nerve into an adjacent vein left in place, our experiments showed that also the use of a free vein graft cap can hinder neuroma formation. Although translation of rat experiments to the clinics should be dealt with caution, our data suggest a careful clinical use of the technique. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009.

Is shock index associated with outcome in children with sepsis/septic shock?*.

Science.gov (United States)

Yasaka, Yuki; Khemani, Robinder G; Markovitz, Barry P

2013-10-01

To investigate the association between PICU shock index (the ratio of heart rate to systolic blood pressure) and PICU mortality in children with sepsis/septic shock. To explore cutoff values for shock index for ICU mortality, how change in shock index over the first 6 hours of ICU admission is associated with outcome, and how the use of vasoactive therapy may affect shock index and its association with outcome. Retrospective cohort. Single-center tertiary PICU. Five hundred forty-four children with the diagnosis of sepsis/septic shock. None. From January 2003 to December 2009, 544 children met International Pediatric Sepsis Consensus Conference of 2005 criteria for sepsis/septic shock. Overall mortality was 23.7%. Among all patients, hourly shock index was associated with mortality: odds ratio of ICU mortality at 0 hour, 1.08, 95% CI (1.04-1.12); odds ratio at 1 hour, 1.09 (1.04-1.13); odds ratio at 2 hours, 1.09 (1.05-1.13); and odds ratio at 6 hours, 1.11 (1.06-1.15). When stratified by age, early shock index was associated with mortality only in children 1-3 and more than or equal to 12 years old. Area under the receiver operating characteristic curve in age 1-3 and more than or equal to 12 years old for shock index at admission was 0.69 (95% CI, 0.58-0.80) and 0.62 (95% CI, 0.52-0.72) respectively, indicating a fair predictive marker. Although higher shock index was associated with increased risk of mortality, there was no particular cutoff value with adequate positive or negative likelihood ratios to identify mortality in any age group of children. The improvement of shock index in the first 6 hours of ICU admission was not associated with outcome when analyzed in all patients. However, among patients whose shock index were above the 50th percentile at ICU admission for each age group, improvement of shock index was associated with lower ICU mortality in children between 1-3 and more than or equal to 12 years old (p = 0.02 and p = 0.03, respectively). When

Biomass shock pretreatment

Science.gov (United States)

Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

2014-07-01

Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

Galen's vein aneurysm as cause of heart failure

International Nuclear Information System (INIS)

Echeverria, Claudia; Cassalett, Gabriel; Franco, Jaime; Carrillo, Gustavo

2005-01-01

We present the case of a newborn admitted to the intensive care unit with a heart failure of difficult medical management. A large ductus arteriosus was found. It was surgically corrected, but the heart failure persisted and did not improve with medical treatment. Incidentally, a big Galen's vein aneurysm was found. Galen's vein aneurysm is a rare congenital pathology, originated by a fusion defect of the internal cerebral veins. Due to its low resistance, it produces a picture of high-output heart failure. Large defects may contain 50% to 60% of cardiac output. An aneurysm may be suspected in each newborn or infant with clinical picture of heart failure and right cardiac chamber dilation without any evidence of structural cardiac anomaly

Mechanisms of shock-induced dynamic friction

International Nuclear Information System (INIS)

Winter, R E; Ball, G J; Keightley, P T

2006-01-01

The mechanism of shock-induced dynamic friction has been explored through an integrated programme of experiments and numerical simulations. A novel experimental technique has been developed for observing the sub-surface deformation in aluminium when sliding against a steel anvil at high velocity and pressure. The experimental observations suggest that slight differences in conditions at the interface between the metals affect frictional behaviour even at the very high-velocity, high-pressure regime studied here. However, a clear finding from the experimental work is the presence of two distinct modes of deformation termed deep and shallow. The deep deformation is observed in a region of the aluminium specimen where the interfacial velocity is relatively low and the shallow deformation is observed in a region where the interfacial velocity is higher. A 1D numerical treatment is presented which predicts the existence of two mechanisms for dynamic friction termed 'asymptotic melting' and 'slide-then-lock'. In both modes there is a warm-up phase in which the interface temperature is increased by frictional heating. For high initial sliding velocity, this is followed by the onset of the asymptotic melting state, in which the temperature is almost constant and melting is approached asymptotically. This mechanism produces low late-time frictional stress and shallow deformation. For lower initial sliding velocity, the warm-up terminates in a violent work hardening event that locks the interface and launches a strong plastic shear wave into the weaker material. This slide-then-lock mechanism is characterized by sustained high frictional stress and deep plastic deformation. These predicted mechanisms offer a plausible and consistent explanation for the abrupt transitions in the depth of sub-surface deformation observed in the experiments. A key conclusion arising from the current work is that the frictional stress does not vary smoothly with pressure or sliding velocity

Renal computed angiography. Part I: Renal CT phlebography. Renal veins variants

International Nuclear Information System (INIS)

Al-Amin, M.; Krupev, M.; Hadjidekov, V.; Plachkov, I.

2012-01-01

The changing trend in renal surgery, transplantation and minimal invasive urology implies preprocedure evaluation of renal veins. Development of imaging methods offers new possibilities for venographic visualization. The goal of this study is to present authors experience in visualization of renal veins using 64 MDCT and to evaluate the utility in assessments of their variants. 128 patients (68 females and 60 males, mean age 53,3) with urological complaints underwent 64MDCT examination including CT angiography. Contrast enhancement includes 3-4ml/sec injection flow of 90 ml contrast medium followed by 20 ml saline at the same rate. In 23 out of 128 examined patients some of the common variants of the renal vein is found. 64 MDCT angiography visualize very well renal veins and becomes method of choice in preoperative assessment of renal vein anatomy. (authors)

The psychological aspects of everyday functioning in a group of patients with varicose veins – an assessment with VEINES Qol/Sym for patients before and after varicose veins surgery

Directory of Open Access Journals (Sweden)

Łukasz Migdalski

2015-10-01

Full Text Available Psychological functioning of patients in early stages of venous insufficiency has not been a common subject of scientific investigation so far, even though this group of patients experiences many limitations in daily functioning, as well as psychological distress. Varicose veins are the most common type of venous insufficiency, with an epidemiology of up to 50% of the western population. The present study is concerned with the functioning of a group undergoing surgery of varicose veins. The operation was carried out in an ambulatory mode, and such psychological factors as acceptance of illness, anxiety–state, anxiety–trait, and wellbeing (treated as personality construct have been considered. It is the first time that such variables have been used with the new tool for assessing quality of life in venous diseases (VEINES Qol/Sym, and no previous findings about applying VEINES Qol/Sym to assess patients after varicose veins operations exist. The results are promising, especially for combining such psychological variables as anxiety, acceptance of illness, or wellbeing with specific venous measures of quality of life. It has been proved that there is a need for monitoring psychological variables in the group of patients in an early stage of chronic venous illness. Further research on other venous patient groups is necessary to fully understand the specificity of these groups.

Analysis of hepatic vein variations in healthy people with 64-slice spiral CT

International Nuclear Information System (INIS)

Zhang Rong; Li Yong; Shen Jun; Zeng Weike; Li Jieting; Huang Suiqiao; Liang Biling; Liu Chao

2007-01-01

Objective: To analyze variations of hepatic vein in healthy people with 64-slice spiral CT. Methods: Seventy-five healthy subjects underwent multi-slice spiral computed (MSCT) hepatic venography. The anatomy of the junction of the hepatic veins with the inferior vena cava and the intrahepatic drainage territory of the hepatic veins and tributaries were evaluated. The hepatic veins were classified according to three anatomic classification (Nakamura's, Marcos's and Kawasaki's classification) methods respectively. Results: There was a common trunk of the middle and left hepatic veins before joining the IVC in 86.7% (65/75)of the cases. In 13.3% (10/75)of the cases, the three main hepatic veins joined the IVC separately. The ratios of Nakamma's classification type A, B, C of hepatic veins were 49.4% (37/75), 37.3% (28/75), and 13.3% (10/75) respectively. The ratios of Marcos's classification type A, B, C of hepatic veins were 56.0% (42/75), 24.0% (18/75), and 20.0% (15/75) respectively. The ratios of Kawasaki's classification type I, II of hepatic vein were 40.0% (30/75) and 60.0% (45/75). Conclusion: Multi-slice spiral CT hepatic venography can provide visualization of peripheral hepatic venous branches in details. (authors)

Cosmic-ray shock acceleration in oblique MHD shocks

Science.gov (United States)

Webb, G. M.; Drury, L. OC.; Volk, H. J.

1986-01-01

A one-dimensional, steady-state hydrodynamical model of cosmic-ray acceleration at oblique MHD shocks is presented. Upstream of the shock the incoming thermal plasma is subject to the adverse pressure gradient of the accelerated particles, the J x B force, as well as the thermal gas pressure gradient. The efficiency of the acceleration of cosmic-rays at the shock as a function of the upstream magnetic field obliquity and upstream plasma beta is investigated. Astrophysical applications of the results are briefly discussed.

Modelling of the controlled melt flow in a glass melting space – Its melting performance and heat losses

Czech Academy of Sciences Publication Activity Database

Jebavá, Marcela; Dyrčíková, Petra; Němec, Lubomír

2015-01-01

Roč. 430, DEC 15 (2015), s. 52-63 ISSN 0022-3093 Institutional support: RVO:67985891 Keywords : glass melt flow * mathematical modelling * energy distribution * space utilizatios * melting performance Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.825, year: 2015

Incidence of Central Vein Stenosis and Occlusion Following Upper Extremity PICC and Port Placement

International Nuclear Information System (INIS)

Gonsalves, Carin F.; Eschelman, David J.; Sullivan, Kevin L.; DuBois, Nancy; Bonn, Joseph

2003-01-01

The purpose of this study was to determine the incidence of central vein stenosis and occlusion following upper extremity placement of peripherally inserted central venous catheters(PICCs) and venous ports. One hundred fifty-four patients who underwent venography of the ipsilateral central veins prior to initial and subsequent venous access device insertion were retrospectively identified. All follow-up venograms were interpreted at the time of catheter placement by one interventional radiologist over a 5-year period and compared to the findings on initial venography. For patients with central vein abnormalities, hospital and home infusion service records and radiology reports were reviewed to determine catheter dwelltime and potential alternative etiologies of central vein stenosis or occlusion. The effect of catheter caliber and dwell time on development of central vein abnormalities was evaluated. Venography performed prior to initial catheter placement showed that 150 patients had normal central veins. Three patients had central vein stenosis, and one had central vein occlusion. Subsequent venograms (n = 154)at the time of additional venous access device placement demonstrated 8 patients with occlusions and 10 with stenoses. Three of the 18 patients with abnormal follow-up venograms were found to have potential alternative causes of central vein abnormalities. Excluding these 3 patients and the 4 patients with abnormal initial venograms, a 7% incidence of central vein stenosis or occlusion was found in patients with prior indwelling catheters and normal initial venograms. Catheter caliber showed no effect on the subsequent development of central vein abnormalities. Patients who developed new or worsened central vein stenosis or occlusion had significantly (p =0.03) longer catheter dwell times than patients without central vein abnormalities. New central vein stenosis or occlusion occurred in 7% of patients following upper arm placement of venous access devices

Research and implementation of finger-vein recognition algorithm

Science.gov (United States)

Pang, Zengyao; Yang, Jie; Chen, Yilei; Liu, Yin

2017-06-01

In finger vein image preprocessing, finger angle correction and ROI extraction are important parts of the system. In this paper, we propose an angle correction algorithm based on the centroid of the vein image, and extract the ROI region according to the bidirectional gray projection method. Inspired by the fact that features in those vein areas have similar appearance as valleys, a novel method was proposed to extract center and width of palm vein based on multi-directional gradients, which is easy-computing, quick and stable. On this basis, an encoding method was designed to determine the gray value distribution of texture image. This algorithm could effectively overcome the edge of the texture extraction error. Finally, the system was equipped with higher robustness and recognition accuracy by utilizing fuzzy threshold determination and global gray value matching algorithm. Experimental results on pairs of matched palm images show that, the proposed method has a EER with 3.21% extracts features at the speed of 27ms per image. It can be concluded that the proposed algorithm has obvious advantages in grain extraction efficiency, matching accuracy and algorithm efficiency.

C1-esterase inhibitor protects against early vein graft remodeling under arterial blood pressure.

Science.gov (United States)

Krijnen, Paul A J; Kupreishvili, Koba; de Vries, Margreet R; Schepers, Abbey; Stooker, Wim; Vonk, Alexander B A; Eijsman, Leon; Van Hinsbergh, Victor W M; Zeerleder, Sacha; Wouters, Diana; van Ham, Marieke; Quax, Paul H A; Niessen, Hans W M

2012-01-01

Arterial pressure induced vein graft injury can result in endothelial loss, accelerated atherosclerosis and vein graft failure. Inflammation, including complement activation, is assumed to play a pivotal role herein. Here, we analyzed the effects of C1-esterase inhibitor (C1inh) on early vein graft remodeling. Human saphenous vein graft segments (n=8) were perfused in vitro with autologous blood either supplemented or not with purified human C1inh at arterial pressure for 6h. The vein segments and perfusion blood were analyzed for cell damage and complement activation. In addition, the effect of purified C1inh on vein graft remodeling was analyzed in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. Application of C1inh in the in vitro perfusion model resulted in significantly higher blood levels and significantly more depositions of C1inh in the vein wall. This coincided with a significant reduction in endothelial loss and deposition of C3d and C4d in the vein wall, especially in the circular layer, compared to vein segments perfused without supplemented C1inh. Administration of purified C1inh significantly inhibited vein graft intimal thickening in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. C1inh significantly protects against early vein graft remodeling, including loss of endothelium and intimal thickening. These data suggest that it may be worth considering its use in patients undergoing coronary artery bypass grafting. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Recent Changes in Arctic Sea Ice Melt Onset, Freeze-Up, and Melt Season Length

Science.gov (United States)

Markus, Thorsten; Stroeve, Julienne C.; Miller, Jeffrey

2010-01-01

In order to explore changes and trends in the timing of Arctic sea ice melt onset and freeze-up and therefore melt season length, we developed a method that obtains this information directly from satellite passive microwave data, creating a consistent data set from 1979 through present. We furthermore distinguish between early melt (the first day of the year when melt is detected) and the first day of continuous melt. A similar distinction is made for the freeze-up. Using this method we analyze trends in melt onset and freeze-up for 10 different Arctic regions. In all regions except for the Sea of Okhotsk, which shows a very slight and statistically insignificant positive trend (O.4 days/decade), trends in melt onset are negative, i.e. towards earlier melt. The trends range from -1.0day/decade for the Bering Sea to -7.3 days/decade for the East Greenland Sea. Except for the Sea of Okhotsk all areas also show a trend towards later autumn freeze onset. The Chukchi/Beaufort Seas and Laptev/East Siberian Seas observe the strongest trends with 7 days/decade. For the entire Arctic, the melt season length has increased by about 20 days over the last 30 years. Largest trends of over 1O days/decade are seen for Hudson Bay, the East Greenland Sea the Laptev/East Siberian Seas, and the Chukchi/Beaufort Seas. Those trends are statistically significant a1 the 99% level.

Reaction of soda-lime-silica glass melt with water vapour at melting temperatures

Czech Academy of Sciences Publication Activity Database

Vernerová, Miroslava; Kloužek, Jaroslav; Němec, Lubomír

2015-01-01

Roč. 416, MAY 15 (2015), s. 21-30 ISSN 0022-3093 R&D Projects: GA TA ČR TA01010844 Institutional support: RVO:67985891 Keywords : glass melt * sulfate * water vapour * bubble nucleation * melt foaming * glass melting Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.825, year: 2015

Compressed sensing approach for wrist vein biometrics.

Science.gov (United States)

Lantsov, Aleksey; Ryabko, Maxim; Shchekin, Aleksey

2018-04-01

The work describes features of the compressed sensing (CS) approach utilized for development of a wearable system for wrist vein recognition with single-pixel detection; we consider this system useful for biometrics authentication purposes. The CS approach implies use of a spatial light modulation (SLM) which, in our case, can be performed differently-with a liquid crystal display or diffusely scattering medium. We show that compressed sensing combined with above-mentioned means of SLM allows us to avoid using an optical system-a limiting factor for wearable devices. The trade-off between the 2 different SLM approaches regarding issues of practical implementation of CS approach for wrist vein recognition purposes is discussed. A possible solution of a misalignment problem-a typical issue for imaging systems based upon 2D arrays of photodiodes-is also proposed. Proposed design of the wearable device for wrist vein recognition is based upon single-pixel detection. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transition metal ions in silicate melts. I. Manganese in sodium silicate melts

Energy Technology Data Exchange (ETDEWEB)

Nelson, C; White, W B

1980-01-01

Optical absorption spectra obtained on glasses quenched from sodium silicate melts show Mn/sup 3 +/ to be the dominant species for melts heated in air and Mn/sup 2 +/ to be the dominant species for melts heated at P/sub O/sub 2// = 10/sup -17/ bar. The absorption spectrum of Mn/sup 3 +/ consists of an intense band at 20,000 cm/sup -1/ with a 15,000 cm/sup -1/ satellite possibly arising from the Jahn-Teller effect. The independence of the spectrum from melt composition and the high band intensity is offered as evidence for a distinct Mn/sup 3 +/ complex in the melt. The spectrum of Mn/sup 2 +/ is weak and many expected bands are not observed. A two-band luminescence spectrum from Mn/sup 2 +/ has been tentatively interpreted as due to Mn/sup 2 +/ in interstitial sites in the network and Mn/sup 2 +/ coordiated by non-bridging oxygens.

Metabolic effects of portal vein sensing.

Science.gov (United States)

Mithieux, G

2014-09-01

The extrinsic gastrointestinal nerves are crucial in the sensing of nutrients and hormones and its translation in terms of control of food intake. Major macronutrients like glucose and protein are sensed by the extrinsic nerves located in the portal vein walls, which signal to the brain and account for the satiety phenomenon they promote. Glucose is sensed in the portal vein by neurons expressing the glucose receptor SGLT3, which activate the main regions of the brain involved in the control of food intake. Proteins indirectly act on food intake by inducing intestinal gluconeogenesis and its sensing by the portal glucose sensor. The mechanism involves a prior antagonism by peptides of the μ-opioid receptors present in the portal vein nervous system and a reflex arc with the brain inducing intestinal gluconeogenesis. In a comparable manner, short-chain fatty acids produced from soluble fibre act via intestinal gluconeogenesis to exert anti-obesity and anti-diabetic effects. In the case of propionate, the mechanism involves a prior activation of the free fatty acid receptor FFAR3 present in the portal nerves and a reflex arc initiating intestinal gluconeogenesis. © 2014 John Wiley & Sons Ltd.

Female Pelvic Vein Embolization: Indications, Techniques, and Outcomes

Energy Technology Data Exchange (ETDEWEB)

Lopez, Anthony James, E-mail: consultant@radiologist.co.uk [The Imaging Clinic (United Kingdom)

2015-08-15

Until recently, the main indication for pelvic vein embolization (PVE) in women was to treat pelvic venous congestion syndrome (PVC) but increasingly, patients with refluxing pelvic veins associated with leg varicosities are also being treated. A more unusual reason for PVE is to treat pelvic venous malformations, although such lesions may be treated with sclerotherapy alone. Embolotherapy for treating PVC has been performed for many years with several published studies included in this review, whilst an emerging indication for PVE is to treat lower limb varicosities associated with pelvic vein reflux. Neither group, however, has been subjected to an adequate randomized, controlled trial. Consequently, some of the information presented in this review should be considered anecdotal (level III evidence) at this stage, and a satisfactory ‘proof’ of clinical efficacy remains deficient until higher-level evidence is presented. Furthermore, a wide range of techniques not accepted by all are used, and some standardization will be required based on future mandatory prospective studies. Large studies have also clearly shown an unacceptably high recurrence rate of leg varicose veins following venous surgery. Furthermore, minimally or non-invasive imaging is now revealing that there is a refluxing pelvic venous source in a significant percentage of women with de novo leg varicose veins, and many more with recurrent varicosities. Considering that just over half the world’s population is female and a significant number of women not only have pelvic venous reflux, but also have associated leg varicosities, minimally invasive treatment of pelvic venous incompetence will become a common procedure.

Female Pelvic Vein Embolization: Indications, Techniques, and Outcomes

International Nuclear Information System (INIS)

Lopez, Anthony James

2015-01-01

Until recently, the main indication for pelvic vein embolization (PVE) in women was to treat pelvic venous congestion syndrome (PVC) but increasingly, patients with refluxing pelvic veins associated with leg varicosities are also being treated. A more unusual reason for PVE is to treat pelvic venous malformations, although such lesions may be treated with sclerotherapy alone. Embolotherapy for treating PVC has been performed for many years with several published studies included in this review, whilst an emerging indication for PVE is to treat lower limb varicosities associated with pelvic vein reflux. Neither group, however, has been subjected to an adequate randomized, controlled trial. Consequently, some of the information presented in this review should be considered anecdotal (level III evidence) at this stage, and a satisfactory ‘proof’ of clinical efficacy remains deficient until higher-level evidence is presented. Furthermore, a wide range of techniques not accepted by all are used, and some standardization will be required based on future mandatory prospective studies. Large studies have also clearly shown an unacceptably high recurrence rate of leg varicose veins following venous surgery. Furthermore, minimally or non-invasive imaging is now revealing that there is a refluxing pelvic venous source in a significant percentage of women with de novo leg varicose veins, and many more with recurrent varicosities. Considering that just over half the world’s population is female and a significant number of women not only have pelvic venous reflux, but also have associated leg varicosities, minimally invasive treatment of pelvic venous incompetence will become a common procedure

[Transposition of the cephalic vein in free flap breast reconstruction: Technical note].

Science.gov (United States)

Silhol, T; Suffee, T; Hivelin, M; Lantieri, L

2018-02-01

Free flaps have become a reliable practice for breast reconstruction. However, the venous congestion is still the most frequent reason of flap failure. It is due to bad quality of the internal mammary veins, a preferential superficial venous outflow of the flap or due to venous thrombosis. The transposition of the cephalic vein could useful in some cases. We describe the surgical technique and suggest an intraoperative algorithm. Seventeen patients (15 DIEP and 2 PAP) were included. Twenty nine point four percent had an unusable internal mammary vein, 23.5% a preferential superficial venous outflow and 47.1% a venous thrombosis. The length of the cephalic vein dissected varied from 15 to 25cm. The mean time of dissection was 39min. There was no flap failure after cephalic vein transposition. The sequelae were one or two scars on the arm without any functional morbidity. The transposition of the cephalic vein is a reliable, less morbid alternative in case of bad quality internal mammary vein with a good quality internal mammary artery, in case of an additional venous outflow necessity or in case of venous thrombosis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Portal vein thrombosis after splenectomy for beta-thalassemia major

International Nuclear Information System (INIS)

Al-Hawsawi, Zakaria M.; Tarawah, Ahmed M.; Hassan, Ruhul Amin A.; Haouimi, Ammar S.

2004-01-01

Portal vein thrombosis is a recognized complication after splenectomy for beta-thalassemia major due to the chronic hypercoagulable state which has been recognized to exist in childhood thalassemia and contribute to thromboembolic events. We reporting one patient with beta-thalassemia major developed portal vein thrombosis following splenectomy. (author)

LOCAL LINE BINARY PATTERN FOR FEATURE EXTRACTION ON PALM VEIN RECOGNITION

Directory of Open Access Journals (Sweden)

Jayanti Yusmah Sari

2015-08-01

Full Text Available In recent years, palm vein recognition has been studied to overcome problems in conventional systems in biometrics technology (finger print, face, and iris. Those problems in biometrics includes convenience and performance. However, due to the clarity of the palm vein image, the veins could not be segmented properly. To overcome this problem, we propose a palm vein recognition system using Local Line Binary Pattern (LLBP method that can extract robust features from the palm vein images that has unclear veins. LLBP is an advanced method of Local Binary Pattern (LBP, a texture descriptor based on the gray level comparison of a neighborhood of pixels. There are four major steps in this paper, Region of Interest (ROI detection, image preprocessing, features extraction using LLBP method, and matching using Fuzzy k-NN classifier. The proposed method was applied on the CASIA Multi-Spectral Image Database. Experimental results showed that the proposed method using LLBP has a good performance with recognition accuracy of 97.3%. In the future, experiments will be conducted to observe which parameter that could affect processing time and recognition accuracy of LLBP is needed

Percutaneous sclerotherapy of testicular vein insufficiency in persistent and recurrent varicocele

International Nuclear Information System (INIS)

Sigmund, G.; Baehren, W.; Gall, H.; Thon, W.

1986-01-01

Among 1217 retrograde phlebographies of left-sided idiopathic varicoceles 66 patients presented because of persistence or recurrence of varicocele, 34 of them after operation and 32 after sclerotherapy. After operation without success there was always - except for one case - a reflux passing the site of ligature. If persistence or recurrence of varicocele occured after sclerotherapy, the testicular (internal spermatic) vein was most often found to be obliterated at the junction with the renal vein and the sonographically proven reflux went via collaterals or unidentified veins which prevented a repeat sclerotheraphy. In 12 out of 32 patients after sclerotherapy a persistent main stem of the testicular vein allowed a second attempt of sclerotherapy. If sclerotherapy in patients after operation or previous sclerotherapy could be performed, it was an effective, low risk procedure on an outpatient basis just as in primary sclerotherapy of testicular vein insufficiency causing varicocele. (orig.) [de