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Sample records for accelerated atherosclerotic process

  1. Severe Brown Fat Lipoatrophy Aggravates Atherosclerotic Process in Male Mice.

    PubMed

    Gómez-Hernández, Almudena; Beneit, Nuria; Escribano, Óscar; Díaz-Castroverde, Sabela; García-Gómez, Gema; Fernández, Silvia; Benito, Manuel

    2016-09-01

    Obesity is one of the major risk factors for the development of cardiovascular diseases and is characterized by abnormal accumulation of adipose tissue, including perivascular adipose tissue (PVAT). However, brown adipose tissue (BAT) activation reduces visceral adiposity. To demonstrate that severe brown fat lipoatrophy might accelerate atherosclerotic process, we generated a new mouse model without insulin receptor (IR) in BAT and without apolipoprotein (Apo)E (BAT-specific IR knockout [BATIRKO];ApoE(-/-) mice) and assessed vascular and metabolic alterations associated to obesity. In addition, we analyzed the contribution of the adipose organ to vascular inflammation. Brown fat lipoatrophy induces visceral adiposity, mainly in gonadal depot (gonadal white adipose tissue [gWAT]), severe glucose intolerance, high postprandial glucose levels, and a severe defect in acute insulin secretion. BATIRKO;ApoE(-/-) mice showed greater hypertriglyceridemia than the obtained in ApoE(-/-) and hypercholesterolemia similar to ApoE(-/-) mice. BATIRKO;ApoE(-/-) mice, in addition to primary insulin resistance in BAT, also showed a significant decrease in insulin signaling in liver, gWAT, heart, aorta artery, and thoracic PVAT. More importantly, our results suggest that severe brown fat lipoatrophy aggravates the atherosclerotic process, characterized by a significant increase of lipid depots, atherosclerotic coverage, lesion size and complexity, increased macrophage infiltration, and proinflammatory markers expression. Finally, an increase of TNF-α and leptin as well as a decrease of adiponectin by BAT, gWAT, and thoracic PVAT might also be responsible of vascular damage. Our results suggest that severe brown lipoatrophy aggravates atherosclerotic process. Thus, BAT activation might protect against obesity and its associated metabolic alterations. PMID:27414981

  2. Raised soluble P-selectin moderately accelerates atherosclerotic plaque progression.

    PubMed

    Woollard, Kevin J; Lumsden, Natalie G; Andrews, Karen L; Aprico, Andrea; Harris, Emma; Irvine, Jennifer C; Jefferis, Ann-maree; Fang, Lu; Kanellakis, Peter; Bobik, Alex; Chin-Dusting, Jaye P F

    2014-01-01

    Soluble P-selectin (sP-selectin), a biomarker of inflammatory related pathologies including cardiovascular and peripheral vascular diseases, also has pro-atherosclerotic effects including the ability to increase leukocyte recruitment and modulate thrombotic responses in vivo. The current study explores its role in progressing atherosclerotic plaque disease. Apoe-/- mice placed on a high fat diet (HFD) were given daily injections of recombinant dimeric murine P-selectin (22.5 µg/kg/day) for 8 or 16 weeks. Saline or sE-selectin injections were used as negative controls. In order to assess the role of sP-selectin on atherothrombosis an experimental plaque remodelling murine model, with sm22α-hDTR Apoe-/- mice on a HFD in conjunction with delivery of diphtheria toxin to induce targeted vascular smooth muscle apoptosis, was used. These mice were similarly given daily injections of sP-selectin for 8 or 16 weeks. While plaque mass and aortic lipid content did not change with sP-selectin treatment in Apoe-/- or SM22α-hDTR Apoe-/- mice on HFD, increased plasma MCP-1 and a higher plaque CD45 content in Apoe-/- HFD mice was observed. As well, a significant shift towards a more unstable plaque phenotype in the SM22α-hDTR Apoe-/- HFD mice, with increased macrophage accumulation and lower collagen content, leading to a lower plaque stability index, was observed. These results demonstrate that chronically raised sP-selectin favours progression of an unstable atherosclerotic plaque phenotype.

  3. Magnetic characterization of human blood in the atherosclerotic process in coronary arteries

    NASA Astrophysics Data System (ADS)

    Janus, B.; Bućko, M. S.; Chrobak, A.; Wasilewski, J.; Zych, M.

    2011-03-01

    In the last decades there has been an increasing interest in biomagnetism—a field of biophysics concerned with the magnetic properties of living organisms. Biomagnetism focuses on the measurement of magnetic properties of biological samples in the clinical environment. Progress in this field can provide new data for the understanding of the pathomechanism of atherosclerosis and support the diagnostic options for the evaluation and treatment of atherothrombotic complications. Lyophilized human blood samples from patients with atherosclerotic lesions (calcium scoring (CS) CS>0) and without atherosclerotic lesions (CS=0) were magnetically investigated. Magnetic measurements (performed in room and low temperature) indicated significant magnetic differences between these two groups of patients. Atherosclerotic blood samples are characterized by higher concentration of ferrimagnetic particles (magnetite and/or maghemite) and significant changes in the superparamagnetic behaviour. This research presents that magnetometry, in combination with medical research can lead to a better understanding of iron physiology in the atherosclerotic process.

  4. Rosiglitazone impedes Porphyromonas gingivalis-accelerated atherosclerosis by downregulating the TLR/NF-κB signaling pathway in atherosclerotic mice.

    PubMed

    Pan, Shengbo; Lei, Lang; Chen, Shuai; Li, Houxuan; Yan, Fuhua

    2014-12-01

    Porphyromonas gingivalis,a predominant periodontal pathogen, is known to accelerate atherosclerosis in hyperlipidemic animals via aberrant inflammatory responses. Peroxisome proliferator-activated receptor gamma (PPARγ) agonists have been reported to exert anti-inflammatory effects in vitro. The purpose of the present study was to investigate the potential protective role of the PPARγ agonist rosiglitazone in pathogen accelerated atherosclerosis in an apolipoprotein E-deficient (ApoE-/-) mouse model. ApoE-/- mice were inoculated intravenously with live P. gingivalis (strain 33277) or the buffer vehicle and treated with rosiglitazone or saline over a 10-week period. Their atherosclerotic status in aortic artery was assessed through histomorphometric analysis, inflammatory agent and lipid profiles in blood was determined by ELISA, and levels of relevant cytokines and Toll-like receptors (TLRs) in aortic tissues were evaluated using immunohistochemistry and quantitative PCR. P. gingivalis inoculation was associated with increased atherosclerotic plaque formation in the aorta and higher levels of serum pro-inflammatory cytokines (tumor necrosis factor-α, monocyte chemotactic protein-1 and interleukin-1β), but the serum lipid profile was not affected by P. gingivalis infection. Levels of tumor necrosis factor-α, monocyte chemotactic protein-1 intercellular cell adhesion molecule-1 and TLRs were higher in the aortic tissues of mice exposed to P. gingivalis, and activation of nuclear factor-κB was also observed. In both P. gingivalis-treated and -untreated ApoE-/- mice, rosiglitazone treatment was associated with less atherosclerotic plaque formation; lower serum inflammatory cytokines, total cholesterol, and low density lipoprotein cholesterol; higher levels of PPARγ, lower amounts of TLR2/4 and downregulated nuclear factor-κB activity in aortic tissues. These findings suggest that rosiglitazone mitigates or prevents P. gingivalis-accelerated atherosclerosis by

  5. Divergent JAM-C Expression Accelerates Monocyte-Derived Cell Exit from Atherosclerotic Plaques

    PubMed Central

    Miljkovic-Licina, Marijana; Lee, Boris P.; Fischer, Nicolas; Fish, Richard J.; Kwak, Brenda; Fisher, Edward A.; Imhof, Beat A.

    2016-01-01

    Atherosclerosis, caused in part by monocytes in plaques, continues to be a disease that afflicts the modern world. Whilst significant steps have been made in treating this chronic inflammatory disease, questions remain on how to prevent monocyte and macrophage accumulation in atherosclerotic plaques. Junctional Adhesion Molecule C (JAM-C) expressed by vascular endothelium directs monocyte transendothelial migration in a unidirectional manner leading to increased inflammation. Here we show that interfering with JAM-C allows reverse-transendothelial migration of monocyte-derived cells, opening the way back out of the inflamed environment. To study the role of JAM-C in plaque regression we used a mouse model of atherosclerosis, and tested the impact of vascular JAM-C expression levels on monocyte reverse transendothelial migration using human cells. Studies in-vitro under inflammatory conditions revealed that overexpression or gene silencing of JAM-C in human endothelium exposed to flow resulted in higher rates of monocyte reverse-transendothelial migration, similar to antibody blockade. We then transplanted atherosclerotic, plaque-containing aortic arches from hyperlipidemic ApoE-/- mice into wild-type normolipidemic recipient mice. JAM-C blockade in the recipients induced greater emigration of monocyte-derived cells and further diminished the size of atherosclerotic plaques. Our findings have shown that JAM-C forms a one-way vascular barrier for leukocyte transendothelial migration only when present at homeostatic copy numbers. We have also shown that blocking JAM-C can reduce the number of atherogenic monocytes/macrophages in plaques by emigration, providing a novel therapeutic strategy for chronic inflammatory pathologies. PMID:27442505

  6. Accelerator simulation of astrophysical processes

    NASA Technical Reports Server (NTRS)

    Tombrello, T. A.

    1983-01-01

    Phenomena that involve accelerated ions in stellar processes that can be simulated with laboratory accelerators are described. Stellar evolutionary phases, such as the CNO cycle, have been partially explored with accelerators, up to the consumption of He by alpha particle radiative capture reactions. Further experimentation is indicated on reactions featuring N-13(p,gamma)O-14, O-15(alpha, gamma)Ne-19, and O-14(alpha,p)F-17. Accelerated beams interacting with thin foils produce reaction products that permit a determination of possible elemental abundances in stellar objects. Additionally, isotopic ratios observed in chondrites can be duplicated with accelerator beam interactions and thus constraints can be set on the conditions producing the meteorites. Data from isotopic fractionation from sputtering, i.e., blasting surface atoms from a material using a low energy ion beam, leads to possible models for processes occurring in supernova explosions. Finally, molecules can be synthesized with accelerators and compared with spectroscopic observations of stellar winds.

  7. Diffusive Shock Acceleration and Reconnection Acceleration Processes

    NASA Astrophysics Data System (ADS)

    Zank, G. P.; Hunana, P.; Mostafavi, P.; Le Roux, J. A.; Li, Gang; Webb, G. M.; Khabarova, O.; Cummings, A.; Stone, E.; Decker, R.

    2015-12-01

    Shock waves, as shown by simulations and observations, can generate high levels of downstream vortical turbulence, including magnetic islands. We consider a combination of diffusive shock acceleration (DSA) and downstream magnetic-island-reconnection-related processes as an energization mechanism for charged particles. Observations of electron and ion distributions downstream of interplanetary shocks and the heliospheric termination shock (HTS) are frequently inconsistent with the predictions of classical DSA. We utilize a recently developed transport theory for charged particles propagating diffusively in a turbulent region filled with contracting and reconnecting plasmoids and small-scale current sheets. Particle energization associated with the anti-reconnection electric field, a consequence of magnetic island merging, and magnetic island contraction, are considered. For the former only, we find that (i) the spectrum is a hard power law in particle speed, and (ii) the downstream solution is constant. For downstream plasmoid contraction only, (i) the accelerated spectrum is a hard power law in particle speed; (ii) the particle intensity for a given energy peaks downstream of the shock, and the distance to the peak location increases with increasing particle energy, and (iii) the particle intensity amplification for a particular particle energy, f(x,c/{c}0)/f(0,c/{c}0), is not 1, as predicted by DSA, but increases with increasing particle energy. The general solution combines both the reconnection-induced electric field and plasmoid contraction. The observed energetic particle intensity profile observed by Voyager 2 downstream of the HTS appears to support a particle acceleration mechanism that combines both DSA and magnetic-island-reconnection-related processes.

  8. Accelerated stochastic diffusion processes

    NASA Astrophysics Data System (ADS)

    Garbaczewski, Piotr

    1990-07-01

    We give a purely probabilistic demonstration that all effects of non-random (external, conservative) forces on the diffusion process can be encoded in the Nelson ansatz for the second Newton law. Each random path of the process together with a probabilistic weight carries a phase accumulation (complex valued) weight. Random path summation (integration) of these weights leads to the transition probability density and transition amplitude respectively between two spatial points in a given time interval. The Bohm-Vigier, Fenyes-Nelson-Guerra and Feynman descriptions of the quantum particle behaviours are in fact equivalent.

  9. ESS Accelerator Cryoplant Process Design

    NASA Astrophysics Data System (ADS)

    Wang, X. L.; Arnold, P.; Hees, W.; Hildenbeutel, J.; Weisend, J. G., II

    2015-12-01

    The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. The ESS accelerator will deliver protons with 5 MW of power to the target at 2.0 GeV, with a nominal current of 62.5 mA. The superconducting part of the accelerator is about 300 meters long and contains 43 cryomodules. The ESS accelerator cryoplant (ACCP) will provide the cooling for the cryomodules and the cryogenic distribution system that delivers the helium to the cryomodules. The ACCP will cover three cryogenic circuits: Bath cooling for the cavities at 2 K, the thermal shields at around 40 K and the power couplers thermalisation with 4.5 K forced helium cooling. The open competitive bid for the ACCP took place in 2014 with Linde Kryotechnik AG being selected as the vendor. This paper summarizes the progress in the ACCP development and engineering. Current status including final cooling requirements, preliminary process design, system configuration, machine concept and layout, main parameters and features, solution for the acceptance tests, exergy analysis and efficiency is presented.

  10. Maximal acceleration and radiative processes

    NASA Astrophysics Data System (ADS)

    Papini, Giorgio

    2015-08-01

    We derive the radiation characteristics of an accelerated, charged particle in a model due to Caianiello in which the proper acceleration of a particle of mass m has the upper limit 𝒜m = 2mc3/ℏ. We find two power laws, one applicable to lower accelerations, the other more suitable for accelerations closer to 𝒜m and to the related physical singularity in the Ricci scalar. Geometrical constraints and power spectra are also discussed. By comparing the power laws due to the maximal acceleration (MA) with that for particles in gravitational fields, we find that the model of Caianiello allows, in principle, the use of charged particles as tools to distinguish inertial from gravitational fields locally.

  11. Lipocalin (LCN) 2 Mediates Pro-Atherosclerotic Processes and Is Elevated in Patients with Coronary Artery Disease

    PubMed Central

    Matthes, Lukas A.; Schuett, Harald; Koch, Ann-Kathrin; Grote, Karsten; Schieffer, Bernhard; Schuett, Jutta; Luchtefeld, Maren

    2015-01-01

    Background Lipocalin (LCN) 2 is associated with multiple acute and chronic inflammatory diseases but the underlying molecular and cellular mechanisms remain unclear. Here, we investigated whether LCN2 is released from macrophages and contributes to pro-atherosclerotic processes and whether LCN2 plasma levels are associated with the severity of coronary artery disease progression in humans. Methods and Results In an autocrine-paracrine loop, tumor necrosis factor (TNF)-α promoted the release of LCN2 from murine bone-marrow derived macrophages (BMDM) and vice versa. Moreover, LCN2 stimulation of BMDM led to up-regulation of M1 macrophage markers. In addition, enhanced migration of monocytic J774A.1 cells towards LCN2 was observed. Furthermore, LCN2 increased the expression of the scavenger receptors Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) as well as scavenger receptor class A-1 (SRA-1) and induced the conversion of macrophages to foam cells. In atherosclerotic lesions of low density lipoprotein receptor-deficient (ldlr−/−) mice fed a high fat, high cholesterol diet, LCN2 was found to be co-localized with macrophages in the shoulder region of the atherosclerotic plaque. In addition, LCN2 plasma levels were significantly increased in plasma samples of these mice. Finally, LCN2 plasma levels correlated with the severity of coronary artery disease (CAD) in patients as determined by coronary angiography. Conclusions Here we demonstrated that LCN2 plays a pivotal role in processes involved in atherogenesis by promoting polarization and migration of monocytic cells and development of macrophages towards foam cells. Moreover, LCN2 may be used as a prognostic marker to determine the status of CAD progression. PMID:26367277

  12. Experiment specific processing of residual acceleration data

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Alexander, J. I. D.

    1992-01-01

    To date, most Spacelab residual acceleration data collection projects have resulted in data bases that are overwhelming to the investigator of low-gravity experiments. This paper introduces a simple passive accelerometer system to measure low-frequency accelerations. Model responses for experiments using actual acceleration data are produced and correlations are made between experiment response and the accelerometer time history in order to test the idea that recorded acceleration data and experimental responses can be usefully correlated. Spacelab 3 accelerometer data are used as input to a variety of experiment models, and sensitivity limits are obtained for particular experiment classes. The modeling results are being used to create experiment-specific residual acceleration data processing schemes for interested investigators.

  13. Processing to determine optical parameters of atherosclerotic disease from phantom and clinical intravascular optical coherence tomography three-dimensional pullbacks.

    PubMed

    Shalev, Ronny; Gargesha, Madhusudhana; Prabhu, David; Tanaka, Kentaro; Rollins, Andrew M; Lamouche, Guy; Bisaillon, Charles-Etienne; Bezerra, Hiram G; Ray, Soumya; Wilson, David L

    2016-04-01

    Analysis of intravascular optical coherence tomography (IVOCT) data has potential for real-time in vivo plaque classification. We developed a processing pipeline on a three-dimensional local region of support for estimation of optical properties of atherosclerotic plaques from coronary artery, IVOCT pullbacks. Using realistic coronary artery disease phantoms, we determined insignificant differences in mean and standard deviation estimates between our pullback analyses and more conventional processing of stationary acquisitions with frame averaging. There was no effect of tissue depth or oblique imaging on pullback parameter estimates. The method's performance was assessed in comparison with observer-defined standards using clinical pullback data. Values (calcium [Formula: see text], lipid [Formula: see text], and fibrous [Formula: see text]) were consistent with previous measurements obtained by other means. Using optical parameters ([Formula: see text], [Formula: see text], [Formula: see text]), we achieved feature space separation of plaque types and classification accuracy of [Formula: see text]. Despite the rapid [Formula: see text] motion and varying incidence angle in pullbacks, the proposed computational pipeline appears to work as well as a more standard "stationary" approach. PMID:27213167

  14. Process in high energy heavy ion acceleration

    NASA Astrophysics Data System (ADS)

    Dinev, D.

    2009-03-01

    A review of processes that occur in high energy heavy ion acceleration by synchrotrons and colliders and that are essential for the accelerator performance is presented. Interactions of ions with the residual gas molecules/atoms and with stripping foils that deliberately intercept the ion trajectories are described in details. These interactions limit both the beam intensity and the beam quality. The processes of electron loss and capture lie at the root of heavy ion charge exchange injection. The review pays special attention to the ion induced vacuum pressure instability which is one of the main factors limiting the beam intensity. The intrabeam scattering phenomena which restricts the average luminosity of ion colliders is discussed. Some processes in nuclear interactions of ultra-relativistic heavy ions that could be dangerous for the performance of ion colliders are represented in the last chapter.

  15. In vitro angioplasty of atherosclerotic human femoral arteries: analysis of the geometrical changes in the individual tissues using MRI and image processing.

    PubMed

    Auer, Martin; Stollberger, Rudolf; Regitnig, Peter; Ebner, Franz; Holzapfel, Gerhard A

    2010-04-01

    Existing atherosclerotic plaque imaging techniques such as intravascular ultrasound, multidetector computed tomography, optical coherence tomography, and high-resolution magnetic resonance imaging (hrMRI) require computerized methods to separate and analyze the plaque morphology. In this work, we perform in vitro balloon angioplasty experiments with 10 human femoral arteries using hrMRI and image processing. The vessel segments contain low-grade to high-grade lesions with very different plaque compositions. The experiments are designed to mimic the in vivo situation. We use a semi-automatic image processing tool to extract the three-dimensional (3D) geometries of the tissue components at four characteristic stages of the angioplasty procedure. The obtained geometries are then used to determine geometrical and mechanical indices in order to characterize, classify, and analyze the atherosclerotic plaques by their specific geometrical changes. During inflation, three vessels ruptured via helical crack propagation. The adventitia, media, and intima did not preserve their area/volume during inflation; the area changes of the lipid pool during inflation were significant. The characterization of changes in individual 3D tissue geometries, together with tissue-specific mechanical properties, may serve as a basis for refined finite element (FE) modeling, which is key to better understand stress evolution in various atherosclerotic plaque configurations. PMID:20148308

  16. Accelerating an iterative process by explicit annihilation

    NASA Technical Reports Server (NTRS)

    Jespersen, D. C.; Buning, P. G.

    1985-01-01

    A slowly convergent stationary iterative process can be accelerated by explicitly annihilating (i.e., eliminating) the dominant eigenvector component of the error. The dominant eigenvalue or complex pair of eigenvalues can be estimated from the solution during the iteration. The corresponding eigenvector or complex pair of eigenvectors can then be annihilated by applying an explicit Richardson process over the basic iterative method. This can be done entirely in real arithmetic by analytically combining the complex conjugate annihilation steps. The technique is applied to an implicit algorithm for the calculation of two dimensional steady transonic flow over a circular cylinder using the equations of compressible inviscid gas dynamics. This demonstrates the use of explicit annihilation on a nonlinear problem.

  17. Accelerating an iterative process by explicit annihilation

    NASA Technical Reports Server (NTRS)

    Jespersen, D. C.; Buning, P. G.

    1983-01-01

    A slowly convergent stationary iterative process can be accelerated by explicitly annihilating (i.e., eliminating) the dominant eigenvector component of the error. The dominant eigenvalue or complex pair of eigenvalues can be estimated from the solution during the iteration. The corresponding eigenvector or complex pair of eigenvectors can then be annihilated by applying an explicit Richardson process over the basic iterative method. This can be done entirely in real arithmetic by analytically combining the complex conjugate annihilation steps. The technique is applied to an implicit algorithm for the calculation of two dimensional steady transonic flow over a circular cylinder using the equations of compressible inviscid gas dynamics. This demonstrates the use of explicit annihilation on a nonlinear problem.

  18. Effect of garlic supplementation on erythrocytes antioxidant parameters, lipid peroxidation, and atherosclerotic plaque formation process in oxidized oil-fed rabbits.

    PubMed

    Zalejska-Fiolka, Jolanta; Kasperczyk, Aleksandra; Kasperczyk, Sławomir; Błaszczyk, Urszula; Birkner, Ewa

    2007-01-01

    Effect of garlic supplementation on blood antioxidant status, lipid peroxidation, and coronary plaque formation process was investigated in oxidized oil-fed rabbits. Eighteen adult male mixed European rabbits were given a balanced diet (21 g% protein, 34 g% fat, 45 g% carbohydrate), which contained isocaloristic addition of nonoxidized or oxidized rapeseed oil in the presence and absence of garlic. The experiment lasted 24 weeks. At the beginning and every 6 weeks, rabbits were weighed, and blood was taken. To evaluate the antioxidant status of the rabbits, erythrocytes malondialdehyde (MDA) concentration, total superoxide dismutase (t-SOD), and glutathione peroxidase (GPX) activations were determined. After the experiment was completed, aortas were dissected for histological examinations. Changes in the contents of the above parameters and histological examinations showed that oxidized rapeseed, oil administered to rabbits, caused the development of atherosclerotic changes and disturbed antioxidant status. The addition of garlic in such diets inhibited atherosclerotic changes in the aorta wall, and it is related to the homeostatic activity of antioxidative enzymes and lipid peroxidation.

  19. Ultrasonic acceleration of enzymatic processing of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzymatic bio-processing of cotton generates significantly less hazardous wastewater effluents, which are readily biodegradable, but it also has several critical shortcomings that impede its acceptance by industries: expensive processing costs and slow reaction rates. It has been found that the intr...

  20. Atherosclerotic and Non-Atherosclerotic Coronary Heart Disease in Women.

    PubMed

    Kolovou, Genovefa; Kolovou, Vana; Koutelou, Maria; Mavrogeni, Sophie

    2015-01-01

    Atherosclerotic Coronary heart disease (CHD) and non-atherosclerotic CHD in individuals less than 50 years of age is considered a "men's case". Undoubtedly, premenopausal women develop atherosclerotic/non-atherosclerotic CHD relatively rarely compared with men. This is attributed mostly to the cardioprotective role of estrogens (mainly estradiol). Nevertheless, there are predisposing conditions, which also make young women vulnerable to develop atherosclerotic/non-atherosclerotic CHD. Women who have classical cardiovascular (CV) risk factors, such as hypertension, diabetes mellitus, smoking, obesity, and dyslipidaemia, are more likely to develop cardiac events, even at a young age. Moreover, there are also other conditions that cause acute coronary syndromes, even in the absence of coronary atheromatic plaques such as myocardial bridge, coronary artery dissection, coronary artery spasm, coronary artery embolism and congenital anomalies of coronary arteries. Also, autoimmune diseases, some of which are more prevalent in women can cause atherosclerotic/ non-atherosclerotic CHD. In this narrative review we have summarized some of the causes that predispose young women to develop atherosclerotic/non-atherosclerotic CHD. PMID:26337108

  1. Computational Tools for Accelerating Carbon Capture Process Development

    SciTech Connect

    Miller, David; Sahinidis, N V; Cozad, A; Lee, A; Kim, H; Morinelly, J; Eslick, J; Yuan, Z

    2013-06-04

    This presentation reports development of advanced computational tools to accelerate next generation technology development. These tools are to develop an optimized process using rigorous models. They include: Process Models; Simulation-Based Optimization; Optimized Process; Uncertainty Quantification; Algebraic Surrogate Models; and Superstructure Optimization (Determine Configuration).

  2. A CLASSIFICATION SCHEME FOR TURBULENT ACCELERATION PROCESSES IN SOLAR FLARES

    SciTech Connect

    Bian, Nicolas; Kontar, Eduard P.; Emslie, A. Gordon E-mail: eduard@astro.gla.ac.uk

    2012-08-01

    We establish a classification scheme for stochastic acceleration models involving low-frequency plasma turbulence in a strongly magnetized plasma. This classification takes into account both the properties of the accelerating electromagnetic field, and the nature of the transport of charged particles in the acceleration region. We group the acceleration processes as either resonant, non-resonant, or resonant-broadened, depending on whether the particle motion is free-streaming along the magnetic field, diffusive, or a combination of the two. Stochastic acceleration by moving magnetic mirrors and adiabatic compressions are addressed as illustrative examples. We obtain expressions for the momentum-dependent diffusion coefficient D(p), both for general forms of the accelerating force and for the situation when the electromagnetic force is wave-like, with a specified dispersion relation {omega} = {omega}(k). Finally, for models considered, we calculate the energy-dependent acceleration time, a quantity that can be directly compared with observations of the time profile of the radiation field produced by the accelerated particles, such as those occuring during solar flares.

  3. Electron accelerators for industrial processing--a review

    SciTech Connect

    Scharf, Waldemar; Wieszczycka, Wioletta

    1999-06-10

    The applications of over 1000 electron beam (EB) accelerator processors used recently worldwide span technological fields from material modification to medical sterilization and food processing. The performance level achieved by the main manufacturers is demonstrated by some selected parameters of processors in the energy range from 0.1 MeV to 10 MeV. The design of the new generation of low cost compact in-line and stand-alone accelerators is discussed.

  4. Recent Advances in Understanding Particle Acceleration Processes in Solar Flares

    NASA Astrophysics Data System (ADS)

    Zharkova, V. V.; Arzner, K.; Benz, A. O.; Browning, P.; Dauphin, C.; Emslie, A. G.; Fletcher, L.; Kontar, E. P.; Mann, G.; Onofri, M.; Petrosian, V.; Turkmani, R.; Vilmer, N.; Vlahos, L.

    2011-09-01

    We review basic theoretical concepts in particle acceleration, with particular emphasis on processes likely to occur in regions of magnetic reconnection. Several new developments are discussed, including detailed studies of reconnection in three-dimensional magnetic field configurations (e.g., current sheets, collapsing traps, separatrix regions) and stochastic acceleration in a turbulent environment. Fluid, test-particle, and particle-in-cell approaches are used and results compared. While these studies show considerable promise in accounting for the various observational manifestations of solar flares, they are limited by a number of factors, mostly relating to available computational power. Not the least of these issues is the need to explicitly incorporate the electrodynamic feedback of the accelerated particles themselves on the environment in which they are accelerated. A brief prognosis for future advancement is offered.

  5. Plasma acceleration processes in an ablative pulsed plasma thruster

    SciTech Connect

    Koizumi, Hiroyuki; Noji, Ryosuke; Komurasaki, Kimiya; Arakawa, Yoshihiro

    2007-03-15

    Plasma acceleration processes in an ablative pulsed plasma thruster (APPT) were investigated. APPTs are space propulsion options suitable for microspacecraft, and have recently attracted much attention because of their low electric power requirements and simple, compact propellant system. The plasma acceleration mechanism, however, has not been well understood. In the present work, emission spectroscopy, high speed photography, and magnetic field measurements are conducted inside the electrode channel of an APPT with rectangular geometry. The successive images of neutral particles and ions give us a comprehensive understanding of their behavior under electromagnetic acceleration. The magnetic field profile clarifies the location where the electromagnetic force takes effect. As a result, it is shown that high density, ablated neutral gas stays near the propellant surface, and only a fraction of the neutrals is converted into plasma and electromagnetically accelerated, leaving the residual neutrals behind.

  6. Observation of laser multiple filamentation process and multiple electron beams acceleration in a laser wakefield accelerator

    SciTech Connect

    Li, Wentao; Liu, Jiansheng; Wang, Wentao; Chen, Qiang; Zhang, Hui; Tian, Ye; Zhang, Zhijun; Qi, Rong; Wang, Cheng; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2013-11-15

    The multiple filaments formation process in the laser wakefield accelerator (LWFA) was observed by imaging the transmitted laser beam after propagating in the plasma of different density. During propagation, the laser first self-focused into a single filament. After that, it began to defocus with energy spreading in the transverse direction. Two filaments then formed from it and began to propagate independently, moving away from each other. We have also demonstrated that the laser multiple filamentation would lead to the multiple electron beams acceleration in the LWFA via ionization-induced injection scheme. Besides, its influences on the accelerated electron beams were also analyzed both in the single-stage LWFA and cascaded LWFA.

  7. [Atherosclerotic renal artery stenosis].

    PubMed

    Sauguet, A; Honton, B

    2014-12-01

    Atherosclerotic renal artery stenosis can cause ischaemic nephropathy and arterial hypertension. Renal artery stenosis (RAS) continues to be a problem for clinicians, with no clear consensus on how to investigate and assess the clinical significance of stenotic lesions and manage the findings. RAS caused by fibromuscular dysplasia is probably commoner than previously appreciated, should be actively looked for in younger hypertensive patients and can be managed successfully with angioplasty. Atheromatous RAS is associated with increased incidence of cardiovascular events and increased cardiovascular mortality, and is likely to be seen with increasing frequency. Many patients with RAS may be managed effectively with medical therapy for several years without endovascular stenting, as demonstrated by randomized, prospective trials including the cardiovascular outcomes in Renal Atherosclerotic Lesions (CORAL) trial, the Angioplasty and Stenting for Renal Artery Lesions (ASTRAL) trial. These trials share the limitation of excluding subsets of patients with high-risk clinical presentations, including episodic pulmonary edema and rapidly progressing renal failure and hypertension. Blood pressure control and medication adjustment may become more difficult with declining renal function and may prevent the use of angiotensin receptor blocker and angiotensin-converting enzyme inhibitors. The objective of this review is to evaluate the current management of RAS for cardiologists in the context of recent randomized clinical trials. There is now interest in looking more closely at patient selection for intervention, with focus on intervening only in patients with the highest-risk presentations such as flash pulmonary edema, rapidly declining renal function and severe resistant hypertension. PMID:25450992

  8. Secondary electron emission from plasma processed accelerating cavity grade niobium

    NASA Astrophysics Data System (ADS)

    Basovic, Milos

    Advances in the particle accelerator technology have enabled numerous fundamental discoveries in 20th century physics. Extensive interdisciplinary research has always supported further development of accelerator technology in efforts of reaching each new energy frontier. Accelerating cavities, which are used to transfer energy to accelerated charged particles, have been one of the main focuses of research and development in the particle accelerator field. Over the last fifty years, in the race to break energy barriers, there has been constant improvement of the maximum stable accelerating field achieved in accelerating cavities. Every increase in the maximum attainable accelerating fields allowed for higher energy upgrades of existing accelerators and more compact designs of new accelerators. Each new and improved technology was faced with ever emerging limiting factors. With the standard high accelerating gradients of more than 25 MV/m, free electrons inside the cavities get accelerated by the field, gaining enough energy to produce more electrons in their interactions with the walls of the cavity. The electron production is exponential and the electron energy transfer to the walls of a cavity can trigger detrimental processes, limiting the performance of the cavity. The root cause of the free electron number gain is a phenomenon called Secondary Electron Emission (SEE). Even though the phenomenon has been known and studied over a century, there are still no effective means of controlling it. The ratio between the electrons emitted from the surface and the impacting electrons is defined as the Secondary Electron Yield (SEY). A SEY ratio larger than 1 designates an increase in the total number of electrons. In the design of accelerator cavities, the goal is to reduce the SEY to be as low as possible using any form of surface manipulation. In this dissertation, an experimental setup was developed and used to study the SEY of various sample surfaces that were treated

  9. Induction linear accelerators for commercial photon irradiation processing

    SciTech Connect

    Matthews, S.M.

    1989-01-13

    A number of proposed irradiation processes requires bulk rather than surface exposure with intense applications of ionizing radiation. Typical examples are irradiation of food packaged into pallet size containers, processing of sewer sludge for recycling as landfill and fertilizer, sterilization of prepackaged medical disposals, treatment of municipal water supplies for pathogen reduction, etc. Volumetric processing of dense, bulky products with ionizing radiation requires high energy photon sources because electrons are not penetrating enough to provide uniform bulk dose deposition in thick, dense samples. Induction Linear Accelerator (ILA) technology developed at the Lawrence Livermore National Laboratory promises to play a key role in providing solutions to this problem. This is discussed in this paper.

  10. Enzyme clustering accelerates processing of intermediates through metabolic channeling

    PubMed Central

    Castellana, Michele; Wilson, Maxwell Z.; Xu, Yifan; Joshi, Preeti; Cristea, Ileana M.; Rabinowitz, Joshua D.; Gitai, Zemer; Wingreen, Ned S.

    2015-01-01

    We present a quantitative model to demonstrate that coclustering multiple enzymes into compact agglomerates accelerates the processing of intermediates, yielding the same efficiency benefits as direct channeling, a well-known mechanism in which enzymes are funneled between enzyme active sites through a physical tunnel. The model predicts the separation and size of coclusters that maximize metabolic efficiency, and this prediction is in agreement with previously reported spacings between coclusters in mammalian cells. For direct validation, we study a metabolic branch point in Escherichia coli and experimentally confirm the model prediction that enzyme agglomerates can accelerate the processing of a shared intermediate by one branch, and thus regulate steady-state flux division. Our studies establish a quantitative framework to understand coclustering-mediated metabolic channeling and its application to both efficiency improvement and metabolic regulation. PMID:25262299

  11. Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications

    SciTech Connect

    Brown, Michael R.

    2006-11-16

    Project Title: Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications PI: Michael R. Brown, Swarthmore College The purpose of the project was to provide theoretical and modeling support to the Swarthmore Spheromak Experiment (SSX). Accordingly, the theoretical effort was tightly integrated into the SSX experimental effort. During the grant period, Michael Brown and his experimental collaborators at Swarthmore, with assistance from W. Matthaeus as appropriate, made substantial progress in understanding the physics SSX plasmas.

  12. Modeling the Acceleration Process of Dust in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Jia, Y. D.; Lai, H.; Russell, C. T.; Wei, H.

    2015-12-01

    In previous studies we have identified structures created by nano-dust in the solar wind, and we have observed the expected draping and diverting signatures of such structures using well-spaced multi-spacecraft observations. In this study, we reproduce such an interaction event with our multi-fluid MHD model, modeling the dust particles as a fluid. When the number density of dust particles is comparable to the solar wind ions, a significant draping in the IMF is created, with amplitude larger than the ambient fluctuations. We note that such a density is well above several nano dust particles per Debye sphere and a dusty fluid is appropriate for modeling the dust-solar wind interaction. We assume a spherical cloud of dust travelling with 90% solar wind speed. In addition to reproducing the IMF response to the nano-dust at the end-stage of dust acceleration, we model the entire process of such acceleration in the gravity field of the inner heliosphere. It takes hours for the smallest dust with 3000 amu per proton charge to reach the solar wind speed. We find the dust cloud stretched along the solar wind flow. Such stretching enhances the draping of IMF, compared to the spherical cloud we used in an earlier stage of this study. This model will be further used to examine magnetic perturbations at an earlier stage of dust cloud acceleration, and then determine the size, density, and total mass of dust cloud, as well as its creation and acceleration.

  13. Optical signal acquisition and processing in future accelerator diagnostics

    SciTech Connect

    Jackson, G.P. ); Elliott, A. )

    1992-01-01

    Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signal to noise ratio are considerations that require compromises limiting the quality of the measurement. Recent advances in fiber optics related technologies have made it possible to acquire and process beam signals in the optical domain. This paper describes recent developments in the application of these technologies to accelerator beam diagnostics. The design and construction of an optical notch filter used for a stochastic cooling system is used as an example. Conceptual ideas for future beam detectors are also presented.

  14. Optical signal acquisition and processing in future accelerator diagnostics

    SciTech Connect

    Jackson, G.P.; Elliott, A.

    1992-12-31

    Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signal to noise ratio are considerations that require compromises limiting the quality of the measurement. Recent advances in fiber optics related technologies have made it possible to acquire and process beam signals in the optical domain. This paper describes recent developments in the application of these technologies to accelerator beam diagnostics. The design and construction of an optical notch filter used for a stochastic cooling system is used as an example. Conceptual ideas for future beam detectors are also presented.

  15. Accelerating sino-atrium computer simulations with graphic processing units.

    PubMed

    Zhang, Hong; Xiao, Zheng; Lin, Shien-fong

    2015-01-01

    Sino-atrial node cells (SANCs) play a significant role in rhythmic firing. To investigate their role in arrhythmia and interactions with the atrium, computer simulations based on cellular dynamic mathematical models are generally used. However, the large-scale computation usually makes research difficult, given the limited computational power of Central Processing Units (CPUs). In this paper, an accelerating approach with Graphic Processing Units (GPUs) is proposed in a simulation consisting of the SAN tissue and the adjoining atrium. By using the operator splitting method, the computational task was made parallel. Three parallelization strategies were then put forward. The strategy with the shortest running time was further optimized by considering block size, data transfer and partition. The results showed that for a simulation with 500 SANCs and 30 atrial cells, the execution time taken by the non-optimized program decreased 62% with respect to a serial program running on CPU. The execution time decreased by 80% after the program was optimized. The larger the tissue was, the more significant the acceleration became. The results demonstrated the effectiveness of the proposed GPU-accelerating methods and their promising applications in more complicated biological simulations. PMID:26406070

  16. Accelerating sino-atrium computer simulations with graphic processing units.

    PubMed

    Zhang, Hong; Xiao, Zheng; Lin, Shien-fong

    2015-01-01

    Sino-atrial node cells (SANCs) play a significant role in rhythmic firing. To investigate their role in arrhythmia and interactions with the atrium, computer simulations based on cellular dynamic mathematical models are generally used. However, the large-scale computation usually makes research difficult, given the limited computational power of Central Processing Units (CPUs). In this paper, an accelerating approach with Graphic Processing Units (GPUs) is proposed in a simulation consisting of the SAN tissue and the adjoining atrium. By using the operator splitting method, the computational task was made parallel. Three parallelization strategies were then put forward. The strategy with the shortest running time was further optimized by considering block size, data transfer and partition. The results showed that for a simulation with 500 SANCs and 30 atrial cells, the execution time taken by the non-optimized program decreased 62% with respect to a serial program running on CPU. The execution time decreased by 80% after the program was optimized. The larger the tissue was, the more significant the acceleration became. The results demonstrated the effectiveness of the proposed GPU-accelerating methods and their promising applications in more complicated biological simulations.

  17. Particle Acceleration via Reconnection Processes in the Supersonic Solar Wind

    NASA Astrophysics Data System (ADS)

    Zank, G. P.; le Roux, J. A.; Webb, G. M.; Dosch, A.; Khabarova, O.

    2014-12-01

    An emerging paradigm for the dissipation of magnetic turbulence in the supersonic solar wind is via localized small-scale reconnection processes, essentially between quasi-2D interacting magnetic islands. Charged particles trapped in merging magnetic islands can be accelerated by the electric field generated by magnetic island merging and the contraction of magnetic islands. We derive a gyrophase-averaged transport equation for particles experiencing pitch-angle scattering and energization in a super-Alfvénic flowing plasma experiencing multiple small-scale reconnection events. A simpler advection-diffusion transport equation for a nearly isotropic particle distribution is derived. The dominant charged particle energization processes are (1) the electric field induced by quasi-2D magnetic island merging and (2) magnetic island contraction. The magnetic island topology ensures that charged particles are trapped in regions where they experience repeated interactions with the induced electric field or contracting magnetic islands. Steady-state solutions of the isotropic transport equation with only the induced electric field and a fixed source yield a power-law spectrum for the accelerated particles with index α = -(3 + MA )/2, where MA is the Alfvén Mach number. Considering only magnetic island contraction yields power-law-like solutions with index -3(1 + τ c /(8τdiff)), where τ c /τdiff is the ratio of timescales between magnetic island contraction and charged particle diffusion. The general solution is a power-law-like solution with an index that depends on the Alfvén Mach number and the timescale ratio τdiff/τ c . Observed power-law distributions of energetic particles observed in the quiet supersonic solar wind at 1 AU may be a consequence of particle acceleration associated with dissipative small-scale reconnection processes in a turbulent plasma, including the widely reported c -5 (c particle speed) spectra observed by Fisk & Gloeckler and Mewaldt et

  18. Graphics processing unit accelerated computation of digital holograms.

    PubMed

    Kang, Hoonjong; Yaraş, Fahri; Onural, Levent

    2009-12-01

    An approximation for fast digital hologram generation is implemented on a central processing unit (CPU), a graphics processing unit (GPU), and a multi-GPU computational platform. The computational performance of the method on each platform is measured and compared. The computational speed on the GPU platform is much faster than on a CPU, and the algorithm could be further accelerated on a multi-GPU platform. In addition, the accuracy of the algorithm for single- and double-precision arithmetic is evaluated. The quality of the reconstruction from the algorithm using single-precision arithmetic is comparable with the quality from the double-precision arithmetic, and thus the implementation using single-precision arithmetic on a multi-GPU platform can be used for holographic video displays.

  19. The spinning disc: studying radial acceleration and its damping process with smartphone acceleration sensors

    NASA Astrophysics Data System (ADS)

    Hochberg, K.; Gröber, S.; Kuhn, J.; Müller, A.

    2014-03-01

    Here, we show the possibility of analysing circular motion and acceleration using the acceleration sensors of smartphones. For instance, the known linear dependence of the radial acceleration on the distance to the centre (a constant angular frequency) can be shown using multiple smartphones attached to a revolving disc. As a second example, the decrease of the radial acceleration and the rotation frequency due to friction can be measured and fitted with a quadratic function, in accordance with theory. Finally, because the disc is not set up exactly horizontal, each smartphone measures a component of the gravitational acceleration that adds to the radial acceleration during one half of the period and subtracts from the radial acceleration during the other half. Hence, every graph shows a small modulation, which can be used to determine the rotation frequency, thus converting a ‘nuisance effect’ into a source of useful information, making additional measurements with stopwatches or the like unnecessary.

  20. Engineering functionality gradients by dip coating process in acceleration mode.

    PubMed

    Faustini, Marco; Ceratti, Davide R; Louis, Benjamin; Boudot, Mickael; Albouy, Pierre-Antoine; Boissière, Cédric; Grosso, David

    2014-10-01

    In this work, unique functional devices exhibiting controlled gradients of properties are fabricated by dip-coating process in acceleration mode. Through this new approach, thin films with "on-demand" thickness graded profiles at the submillimeter scale are prepared in an easy and versatile way, compatible for large-scale production. The technique is adapted to several relevant materials, including sol-gel dense and mesoporous metal oxides, block copolymers, metal-organic framework colloids, and commercial photoresists. In the first part of the Article, an investigation on the effect of the dip coating speed variation on the thickness profiles is reported together with the critical roles played by the evaporation rate and by the viscosity on the fluid draining-induced film formation. In the second part, dip-coating in acceleration mode is used to induce controlled variation of functionalities by playing on structural, chemical, or dimensional variations in nano- and microsystems. In order to demonstrate the full potentiality and versatility of the technique, original graded functional devices are made including optical interferometry mirrors with bidirectional gradients, one-dimensional photonic crystals with a stop-band gradient, graded microfluidic channels, and wetting gradient to induce droplet motion.

  1. Particle acceleration via reconnection processes in the supersonic solar wind

    SciTech Connect

    Zank, G. P.; Le Roux, J. A.; Webb, G. M.; Dosch, A.; Khabarova, O.

    2014-12-10

    An emerging paradigm for the dissipation of magnetic turbulence in the supersonic solar wind is via localized small-scale reconnection processes, essentially between quasi-2D interacting magnetic islands. Charged particles trapped in merging magnetic islands can be accelerated by the electric field generated by magnetic island merging and the contraction of magnetic islands. We derive a gyrophase-averaged transport equation for particles experiencing pitch-angle scattering and energization in a super-Alfvénic flowing plasma experiencing multiple small-scale reconnection events. A simpler advection-diffusion transport equation for a nearly isotropic particle distribution is derived. The dominant charged particle energization processes are (1) the electric field induced by quasi-2D magnetic island merging and (2) magnetic island contraction. The magnetic island topology ensures that charged particles are trapped in regions where they experience repeated interactions with the induced electric field or contracting magnetic islands. Steady-state solutions of the isotropic transport equation with only the induced electric field and a fixed source yield a power-law spectrum for the accelerated particles with index α = –(3 + M{sub A} )/2, where M{sub A} is the Alfvén Mach number. Considering only magnetic island contraction yields power-law-like solutions with index –3(1 + τ {sub c}/(8τ{sub diff})), where τ {sub c}/τ{sub diff} is the ratio of timescales between magnetic island contraction and charged particle diffusion. The general solution is a power-law-like solution with an index that depends on the Alfvén Mach number and the timescale ratio τ{sub diff}/τ {sub c}. Observed power-law distributions of energetic particles observed in the quiet supersonic solar wind at 1 AU may be a consequence of particle acceleration associated with dissipative small-scale reconnection processes in a turbulent plasma, including the widely reported c {sup –5} (c particle

  2. Accelerating sparse linear algebra using graphics processing units

    NASA Astrophysics Data System (ADS)

    Spagnoli, Kyle E.; Humphrey, John R.; Price, Daniel K.; Kelmelis, Eric J.

    2011-06-01

    The modern graphics processing unit (GPU) found in many standard personal computers is a highly parallel math processor capable of over 1 TFLOPS of peak computational throughput at a cost similar to a high-end CPU with excellent FLOPS-to-watt ratio. High-level sparse linear algebra operations are computationally intense, often requiring large amounts of parallel operations and would seem a natural fit for the processing power of the GPU. Our work is on a GPU accelerated implementation of sparse linear algebra routines. We present results from both direct and iterative sparse system solvers. The GPU execution model featured by NVIDIA GPUs based on CUDA demands very strong parallelism, requiring between hundreds and thousands of simultaneous operations to achieve high performance. Some constructs from linear algebra map extremely well to the GPU and others map poorly. CPUs, on the other hand, do well at smaller order parallelism and perform acceptably during low-parallelism code segments. Our work addresses this via hybrid a processing model, in which the CPU and GPU work simultaneously to produce results. In many cases, this is accomplished by allowing each platform to do the work it performs most naturally. For example, the CPU is responsible for graph theory portion of the direct solvers while the GPU simultaneously performs the low level linear algebra routines.

  3. GPU accelerated processing of astronomical high frame-rate videosequences

    NASA Astrophysics Data System (ADS)

    Vítek, Stanislav; Švihlík, Jan; Krasula, Lukáš; Fliegel, Karel; Páta, Petr

    2015-09-01

    Astronomical instruments located around the world are producing an incredibly large amount of possibly interesting scientific data. Astronomical research is expanding into large and highly sensitive telescopes. Total volume of data rates per night of operations also increases with the quality and resolution of state-of-the-art CCD/CMOS detectors. Since many of the ground-based astronomical experiments are placed in remote locations with limited access to the Internet, it is necessary to solve the problem of the data storage. It mostly means that current data acquistion, processing and analyses algorithm require review. Decision about importance of the data has to be taken in very short time. This work deals with GPU accelerated processing of high frame-rate astronomical video-sequences, mostly originating from experiment MAIA (Meteor Automatic Imager and Analyser), an instrument primarily focused to observing of faint meteoric events with a high time resolution. The instrument with price bellow 2000 euro consists of image intensifier and gigabite ethernet camera running at 61 fps. With resolution better than VGA the system produces up to 2TB of scientifically valuable video data per night. Main goal of the paper is not to optimize any GPU algorithm, but to propose and evaluate parallel GPU algorithms able to process huge amount of video-sequences in order to delete all uninteresting data.

  4. Detection of atherosclerotic vascular tissue from optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Prakash, Ammu; Hewko, Mark; Sowa, Mike; Sherif, Sherif

    2012-10-01

    Atherosclerotic coronary artery disease continues to be one of the major causes of mortality. Prevention, diagnosis and treatment of atherosclerotic coronary artery disease are dependent on the detection of high risk atherosclerotic plaque. As age is one of the most important risk factors, atherosclerosis worsens steadily with increasing age. Automatic characterization of atherosclerotic plaque using the optical coherence tomography (OCT) images provides a powerful tool to classify patients with high risk plaque. In this study we develop an automatic classifier to detect atherosclerotic plaque in young and old Watanabe heritable hyperlipidemic (WHHL) rabbits, using OCT images without reliance on visual inspection. Our classifier based on texture analysis technique may provide an efficient tool for detecting invisible changes in tissue structure. We extracted a set of 22 statistical textural features for each image using the spatial gray level dependence matrix (SGLDM) method. An optimal scalar feature selection process was carried to select the best discriminating features that employ the Fisher discriminant ratio (FDR) criterion, and cross correlation measure between the pairs of features. Using these optimal features, we formed a combination of 5 best classification features using an exhaustive search method. A combined feature set was finally employed for the classification of plaque. We obtained correct classification rate and validation of 76.67% and 75% respectively.

  5. Analyzing Collision Processes with the Smartphone Acceleration Sensor

    ERIC Educational Resources Information Center

    Vogt, Patrik; Kuhn, Jochen

    2014-01-01

    It has been illustrated several times how the built-in acceleration sensors of smartphones can be used gainfully for quantitative experiments in school and university settings (see the overview in Ref. 1 ). The physical issues in that case are manifold and apply, for example, to free fall, radial acceleration, several pendula, or the exploitation…

  6. An Unusual Process of Accelerated Weathering of a Marly Limestone

    NASA Astrophysics Data System (ADS)

    Ercoli, L.; Rizzo, G.; Algozzini, G.

    2003-04-01

    This work deals with a singular case of stone deterioration, which occurred during the restoration of the Cathedral of Cefalù. In particular, a significant process of stone decohesion started after a consolidation treatment on ashlars of the external face of the cloister portico. A study was carried out to characterize the stone and to investigate the deterioration process. Petrographical, chemical and physical analyses were performed on samples taken from the wall. The results indicate that the medieval monument was built using a Pliocene marly limestone, called "trubo", quarried from outcrops of the environs of Cefalù. The rock is soft and uniformely cemented. The carbonatic fraction of the rock is due to foraminifera shells; the rock also contains detritic quartz, feldspate and glauconite. The clay minerals, mainly illite and montmorillonite, are widespread in the rock in the form of thin layers. The use of such a stone in a building of relevant artistic value is definitely unusual. In fact, the "trubo" is a rock subjected to natural decay because of its mineralogical composition and fabric; as effect of natural weathering, in the outcrops the rock disaggregates uniformely, producing silt. In the cloister this effect was magnified by extreme environmental conditions (marine spray, severe excursions of both relative humidity and temperature). Furthermore, after soluble salts removing and subsequent consolidation with ethyl silicate, a significant acceleration of the decay process was observed, producing friable scales detach for a depth of about 3 cm into the ashlars. The stone appeared corroded and uneven. Experimental tests were performed in laboratory in order to evidence any origin of incompatibility between such stone composition and the treatments carried out, which on the other hand are the most generally adopted in restoration interventions.

  7. Progress in atherosclerotic plaque imaging

    PubMed Central

    Soloperto, Giulia; Casciaro, Sergio

    2012-01-01

    Cardiovascular diseases are the primary cause of mortality in the industrialized world, and arterial obstruction, triggered by rupture-prone atherosclerotic plaques, lead to myocardial infarction and cerebral stroke. Vulnerable plaques do not necessarily occur with flow-limiting stenosis, thus conventional luminographic assessment of the pathology fails to identify unstable lesions. In this review we discuss the currently available imaging modalities used to investigate morphological features and biological characteristics of the atherosclerotic plaque. The different imaging modalities such as ultrasound, magnetic resonance imaging, computed tomography, nuclear imaging and their intravascular applications are illustrated, highlighting their specific diagnostic potential. Clinically available and upcoming methodologies are also reviewed along with the related challenges in their clinical translation, concerning the specific invasiveness, accuracy and cost-effectiveness of these methods. PMID:22937215

  8. Anomalous/Fractional Diffusion in Particle Acceleration Processes.

    NASA Astrophysics Data System (ADS)

    Bian, Nicolas

    2016-07-01

    This talk is aimed at reviewing a certain number of theoretical aspects concerning the relation between stochastic acceleration and anomalous/fractional transport of particles. As a matter of fact, anomalous velocity-space diffusion is required within any stochastic acceleration scenario to explain the formation of the ubiquitous power-law tail of non-thermal particles, as observed e.g. in the accelerated distribution of electrons during solar flares. I will establish a classification scheme for stochastic acceleration models involving turbulence in magnetized plasmas. This classification takes into account both the properties of the accelerating electromagnetic field, and the nature of the spatial transport (possibly fractional) of charged particles in the acceleration region. I will also discuss recent attempts to obtain spatially non-local and fractional diffusion equations directly from first principles, starting either from the Fokker-Planck equation in the large mean free-path regime or the Boltzmann equation involving velocity-space relaxation toward the kappa distribution instead of the standard Maxwellian distribution.

  9. Accelerating Cardiac Bidomain Simulations Using Graphics Processing Units

    PubMed Central

    Neic, Aurel; Liebmann, Manfred; Hoetzl, Elena; Mitchell, Lawrence; Vigmond, Edward J.; Haase, Gundolf

    2013-01-01

    Anatomically realistic and biophysically detailed multiscale computer models of the heart are playing an increasingly important role in advancing our understanding of integrated cardiac function in health and disease. Such detailed simulations, however, are computationally vastly demanding, which is a limiting factor for a wider adoption of in-silico modeling. While current trends in high-performance computing (HPC) hardware promise to alleviate this problem, exploiting the potential of such architectures remains challenging since strongly scalable algorithms are necessitated to reduce execution times. Alternatively, acceleration technologies such as graphics processing units (GPUs) are being considered. While the potential of GPUs has been demonstrated in various applications, benefits in the context of bidomain simulations where large sparse linear systems have to be solved in parallel with advanced numerical techniques are less clear. In this study, the feasibility of multi-GPU bidomain simulations is demonstrated by running strong scalability benchmarks using a state-of-the-art model of rabbit ventricles. The model is spatially discretized using the finite element methods (FEM) on fully unstructured grids. The GPU code is directly derived from a large pre-existing code, the Cardiac Arrhythmia Research Package (CARP), with very minor perturbation of the code base. Overall, bidomain simulations were sped up by a factor of 11.8 to 16.3 in benchmarks running on 6–20 GPUs compared to the same number of CPU cores. To match the fastest GPU simulation which engaged 20GPUs, 476 CPU cores were required on a national supercomputing facility. PMID:22692867

  10. Accelerating molecular docking calculations using graphics processing units.

    PubMed

    Korb, Oliver; Stützle, Thomas; Exner, Thomas E

    2011-04-25

    The generation of molecular conformations and the evaluation of interaction potentials are common tasks in molecular modeling applications, particularly in protein-ligand or protein-protein docking programs. In this work, we present a GPU-accelerated approach capable of speeding up these tasks considerably. For the evaluation of interaction potentials in the context of rigid protein-protein docking, the GPU-accelerated approach reached speedup factors of up to over 50 compared to an optimized CPU-based implementation. Treating the ligand and donor groups in the protein binding site as flexible, speedup factors of up to 16 can be observed in the evaluation of protein-ligand interaction potentials. Additionally, we introduce a parallel version of our protein-ligand docking algorithm PLANTS that can take advantage of this GPU-accelerated scoring function evaluation. We compared the GPU-accelerated parallel version to the same algorithm running on the CPU and also to the highly optimized sequential CPU-based version. In terms of dependence of the ligand size and the number of rotatable bonds, speedup factors of up to 10 and 7, respectively, can be observed. Finally, a fitness landscape analysis in the context of rigid protein-protein docking was performed. Using a systematic grid-based search methodology, the GPU-accelerated version outperformed the CPU-based version with speedup factors of up to 60. PMID:21434638

  11. Quantification of Apoptosis in Mouse Atherosclerotic Lesions.

    PubMed

    Figg, Nichola L; Bennett, Martin R

    2015-01-01

    Apoptosis is a key process occurring in atherosclerosis, both in humans and in animal models. Apoptosis occurs in all cell types studied thus far, and thus lineage marking is often necessary. Apoptosis should be ascertained using a combination of morphological features and activation of specific pathways (e.g., terminal UTP nick end labeling-TUNEL). Both TUNEL and cryptic epitope antibodies (e.g., cleaved caspase 3) can be used, although they will often give different frequencies. Apoptotic frequency but not rate can be estimated from these methods, as we do not know the timing of apoptosis or how much of the process is marked by each method. We describe the morphological and immunohistochemical methods used in our laboratory to detect apoptotic cells in animal and human atherosclerotic plaques.

  12. Accelerators for E-beam and X-ray processing

    NASA Astrophysics Data System (ADS)

    Auslender, V. L.; Bryazgin, A. A.; Faktorovich, B. L.; Gorbunov, V. A.; Kokin, E. N.; Korobeinikov, M. V.; Krainov, G. S.; Lukin, A. N.; Maximov, S. A.; Nekhaev, V. E.; Panfilov, A. D.; Radchenko, V. N.; Tkachenko, V. O.; Tuvik, A. A.; Voronin, L. A.

    2002-03-01

    During last years the demand for pasteurization and desinsection of various food products (meat, chicken, sea products, vegetables, fruits, etc.) had increased. The treatment of these products in industrial scale requires the usage of powerful electron accelerators with energy 5-10 MeV and beam power at least 50 kW or more. The report describes the ILU accelerators with energy range up to 10 MeV and beam power up to 150 kW.The different irradiation schemes in electron beam and X-ray modes for various products are described. The design of the X-ray converter and 90° beam bending system are also given.

  13. New high-current Dynamitron accelerators for electron beam processing

    NASA Astrophysics Data System (ADS)

    Cleland, M. R.; Thompson, C. C.; Saito, H.; Lisanti, T. F.; Burgess, R. G.; Malone, H. F.; Loby, R. J.; Galloway, R. A.

    1993-06-01

    The material throughput capabilities of RDI's new 550 keV and 800 keV Dynamitron R accelerators have been enhanced by increasing their beam current ratings from 100 mA to 160 mA. Future requirements up to 200 mA have been anticipated in the designs. The high-voltage power supply, beam scanner and beam window have all been modified to accommodate the higher current ratings. A new programmable control system has also been developed. The basic design concepts are described and performance data are presented in this paper.

  14. Next generation tools to accelerate the synthetic biology process.

    PubMed

    Shih, Steve C C; Moraes, Christopher

    2016-05-16

    Synthetic biology follows the traditional engineering paradigm of designing, building, testing and learning to create new biological systems. While such approaches have enormous potential, major challenges still exist in this field including increasing the speed at which this workflow can be performed. Here, we present recently developed microfluidic tools that can be used to automate the synthetic biology workflow with the goal of advancing the likelihood of producing desired functionalities. With the potential for programmability, automation, and robustness, the integration of microfluidics and synthetic biology has the potential to accelerate advances in areas such as bioenergy, health, and biomaterials. PMID:27146265

  15. Accelerate!

    PubMed

    Kotter, John P

    2012-11-01

    The old ways of setting and implementing strategy are failing us, writes the author of Leading Change, in part because we can no longer keep up with the pace of change. Organizational leaders are torn between trying to stay ahead of increasingly fierce competition and needing to deliver this year's results. Although traditional hierarchies and managerial processes--the components of a company's "operating system"--can meet the daily demands of running an enterprise, they are rarely equipped to identify important hazards quickly, formulate creative strategic initiatives nimbly, and implement them speedily. The solution Kotter offers is a second system--an agile, networklike structure--that operates in concert with the first to create a dual operating system. In such a system the hierarchy can hand off the pursuit of big strategic initiatives to the strategy network, freeing itself to focus on incremental changes to improve efficiency. The network is populated by employees from all levels of the organization, giving it organizational knowledge, relationships, credibility, and influence. It can Liberate information from silos with ease. It has a dynamic structure free of bureaucratic layers, permitting a level of individualism, creativity, and innovation beyond the reach of any hierarchy. The network's core is a guiding coalition that represents each level and department in the hierarchy, with a broad range of skills. Its drivers are members of a "volunteer army" who are energized by and committed to the coalition's vividly formulated, high-stakes vision and strategy. Kotter has helped eight organizations, public and private, build dual operating systems over the past three years. He predicts that such systems will lead to long-term success in the 21st century--for shareholders, customers, employees, and companies themselves. PMID:23155997

  16. Accelerate!

    PubMed

    Kotter, John P

    2012-11-01

    The old ways of setting and implementing strategy are failing us, writes the author of Leading Change, in part because we can no longer keep up with the pace of change. Organizational leaders are torn between trying to stay ahead of increasingly fierce competition and needing to deliver this year's results. Although traditional hierarchies and managerial processes--the components of a company's "operating system"--can meet the daily demands of running an enterprise, they are rarely equipped to identify important hazards quickly, formulate creative strategic initiatives nimbly, and implement them speedily. The solution Kotter offers is a second system--an agile, networklike structure--that operates in concert with the first to create a dual operating system. In such a system the hierarchy can hand off the pursuit of big strategic initiatives to the strategy network, freeing itself to focus on incremental changes to improve efficiency. The network is populated by employees from all levels of the organization, giving it organizational knowledge, relationships, credibility, and influence. It can Liberate information from silos with ease. It has a dynamic structure free of bureaucratic layers, permitting a level of individualism, creativity, and innovation beyond the reach of any hierarchy. The network's core is a guiding coalition that represents each level and department in the hierarchy, with a broad range of skills. Its drivers are members of a "volunteer army" who are energized by and committed to the coalition's vividly formulated, high-stakes vision and strategy. Kotter has helped eight organizations, public and private, build dual operating systems over the past three years. He predicts that such systems will lead to long-term success in the 21st century--for shareholders, customers, employees, and companies themselves.

  17. [Atherosclerotic renal artery disease diagnosis update].

    PubMed

    Meier, Pascal; Haesler, Erik; Teta, Daniel; Qanadli, Salah Dine; Burnier, Michel

    2009-02-01

    Atherosclerotic renal artery disease represents a cause of which little is known but not a cause to be neglected for hypertension and renal insufficiency. Even though its occurrence remains badly defined, atherosclerotic renal artery disease is constantly on the rise due to the aging population, the never prevailing hypertension and diabetes mellitus. This review aims to give a clinical profile of patients presenting with atherosclerotic renal artery disease and to discuss, in the light of study results, which diagnostic evaluation should be used considering the sequence and the benefit and risk of each in order to initiate a personalized treatment. Patients affected by atherosclerotic renal artery disease are likely to have more complications and more extensive target-organ damage than patients without renal artery stenosis. The evolution of the atherosclerotic renal artery disease is in general slow and progressive. Nevertheless, certain clinical cases manifest themselves with the onset of acute renal failure bought upon by the administration of blockers of the rennin-angiotensin-aldosterone system, or by some other causes responsible for a sudden drop in renal plasma flow (e.g., thrombosis of the renal artery). The relationship between atherosclerotic renal artery disease and atherosclerosis is complex, and mediators implicated in the pathophysiology of renovascular disease may also contribute to the progression of cardiovascular damage. An early assumption of the atherosclerotic renal artery stenosis is warranted to determine the adapted treatment (i.e., medical treatment, revascularisation...) just as the assumption and the correction of the more general cardiovascular risk factors. PMID:18809367

  18. Novel process windows for enabling, accelerating, and uplifting flow chemistry.

    PubMed

    Hessel, Volker; Kralisch, Dana; Kockmann, Norbert; Noël, Timothy; Wang, Qi

    2013-05-01

    Novel Process Windows make use of process conditions that are far from conventional practices. This involves the use of high temperatures, high pressures, high concentrations (solvent-free), new chemical transformations, explosive conditions, and process simplification and integration to boost synthetic chemistry on both the laboratory and production scale. Such harsh reaction conditions can be safely reached in microstructured reactors due to their excellent transport intensification properties. This Review discusses the different routes towards Novel Process Windows and provides several examples for each route grouped into different classes of chemical and process-design intensification.

  19. 77 FR 21991 - Federal Housing Administration (FHA): Multifamily Accelerated Processing (MAP)-Lender and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT Federal Housing Administration (FHA): Multifamily Accelerated Processing (MAP)--Lender and Underwriter Eligibility Criteria and Credit Watch for MAP Lenders AGENCY: Office of the...

  20. Approach to atherosclerotic renovascular disease: 2016

    PubMed Central

    Daloul, Reem; Morrison, Aubrey R.

    2016-01-01

    The management of atherosclerotic renal artery stenosis in patients with hypertension or impaired renal function remains a clinical dilemma. The current general consensus, supported by the results of the Angioplasty and Stenting for Renal Atherosclerotic Lesions and Cardiovascular Outcomes for Renal Artery Lesions trials, argues strongly against endovascular intervention in favor of optimal medical management. We discuss the limitations and implications of the contemporary clinical trials and present our approach and formulate clear recommendations to help with the management of patients with atherosclerotic narrowing of the renal artery. PMID:27679718

  1. Approach to atherosclerotic renovascular disease: 2016

    PubMed Central

    Daloul, Reem; Morrison, Aubrey R.

    2016-01-01

    The management of atherosclerotic renal artery stenosis in patients with hypertension or impaired renal function remains a clinical dilemma. The current general consensus, supported by the results of the Angioplasty and Stenting for Renal Atherosclerotic Lesions and Cardiovascular Outcomes for Renal Artery Lesions trials, argues strongly against endovascular intervention in favor of optimal medical management. We discuss the limitations and implications of the contemporary clinical trials and present our approach and formulate clear recommendations to help with the management of patients with atherosclerotic narrowing of the renal artery.

  2. Approach to atherosclerotic renovascular disease: 2016.

    PubMed

    Daloul, Reem; Morrison, Aubrey R

    2016-10-01

    The management of atherosclerotic renal artery stenosis in patients with hypertension or impaired renal function remains a clinical dilemma. The current general consensus, supported by the results of the Angioplasty and Stenting for Renal Atherosclerotic Lesions and Cardiovascular Outcomes for Renal Artery Lesions trials, argues strongly against endovascular intervention in favor of optimal medical management. We discuss the limitations and implications of the contemporary clinical trials and present our approach and formulate clear recommendations to help with the management of patients with atherosclerotic narrowing of the renal artery. PMID:27679718

  3. Computational Tools for Accelerating Carbon Capture Process Development

    SciTech Connect

    Miller, David

    2013-01-01

    The goals of the work reported are: to develop new computational tools and models to enable industry to more rapidly develop and deploy new advanced energy technologies; to demonstrate the capabilities of the CCSI Toolset on non-proprietary case studies; and to deploy the CCSI Toolset to industry. Challenges of simulating carbon capture (and other) processes include: dealing with multiple scales (particle, device, and whole process scales); integration across scales; verification, validation, and uncertainty; and decision support. The tools cover: risk analysis and decision making; validated, high-fidelity CFD; high-resolution filtered sub-models; process design and optimization tools; advanced process control and dynamics; process models; basic data sub-models; and cross-cutting integration tools.

  4. A focus on inflammation as a major risk factor for atherosclerotic cardiovascular diseases.

    PubMed

    Gregersen, Ida; Holm, Sverre; Dahl, Tuva B; Halvorsen, Bente; Aukrust, Pål

    2016-01-01

    Atherosclerosis is a dynamic, pathogenic process in the artery wall, with potential adverse outcome for the host. Acute events such as myocardial infarction and ischemic stroke often result from rupture of unstable atherosclerotic lesions. Understanding the underlying pathology of such lesions and why and when they rupture, is therefore of great interest for the development of new diagnostics and treatment. Inflammation is one of the key drivers of atherosclerotic plaque development and the interplay between inflammation and lipids constitutes the hallmark of atherosclerotic disease. This review summarizes the role of inflammation in atherosclerosis and presents some of the latest discoveries as well as unmet needs regarding the role of inflammation as major risk factor in atherosclerotic disease.

  5. The angiotensin receptor blocker, azilsartan medoxomil (TAK-491), suppresses vascular wall expression of plasminogen activator inhibitor type-I protein potentially facilitating the stabilization of atherosclerotic plaques.

    PubMed

    French, Christopher J; Zaman, A K M Tarikuz; Sobel, Burton E

    2011-08-01

    Increased expression of plasminogen activator inhibitor type-I (PAI-1) in vessel walls seems to accelerate atherosclerosis. Angiotensin II can increase the synthesis of PAI-1. Inhibition of this process may facilitate migration of vascular smooth muscle cells (VSMCs) stabilizing atherosclerotic plaques. To determine whether the inhibition of the angiotensin II type 1 receptor can blunt the expression of PAI-1 protein in the aortic wall, we administered azilsartan medoxomil (AZL-M), a prodrug of an angiotensin II type 1 receptor blocker developed by the Takeda Pharmaceutical Company Limited, for 16 weeks to ApoE knockout mice on a high fat diet rendered overexpressors of PAI-1 in VSMCs. Homogenates of the pooled aortas from each group were assayed for PAI-1 by enzyme-linked immunosorbent assay. Cellularity of atherosclerotic lesions was assessed by 4',6-diamidino-2-phenylindole staining in sections of aortic lesions, and collagen content in the lesions was quantified by immunohistochemistry. Aortic wall PAI-1 was decreased by each of the 3 dosage regimens of AZL-M (0.1-10 mg/kg). Cellularity and collagen were increased in lesions from mice given AZL-M, consistent with the development of more stable plaques. Accordingly, the suppression of PAI-1 expression by AZL-M may attenuate the evolution of atherosclerotic plaques vulnerable to rupture.

  6. Biotherapeutics in orthopaedic medicine: accelerating the healing process?

    PubMed

    Puleo, David

    2003-01-01

    Musculoskeletal injuries have a significant human and financial impact on society. In particular, fractures that lead to delayed union or even nonunion represent a serious clinical challenge for which few treatment options are available. The multiple surgical procedures often needed are associated with patient morbidity and reduced quality of life. Biotechnological advances have made possible a host of potential treatments for enhancing and accelerating the repair of bone. By stimulating the body's own healing mechanisms, clinical outcomes may be improved while also containing procedural costs. Biotherapeutics may take the form of proteins, genes or cells that can be used to treat the injury. Protein biotherapeutics have received the greatest attention. Using recombinant DNA techniques, growth factors that play important roles in bone development and repair are being produced. By delivering exogenous growth factors to the site of injury in an appropriate manner, bone formation can be stimulated. Although individual proteins have been the primary focus of investigation, combinations of biomolecules can have additive, and perhaps synergistic, effects. Alternatively, genes coding for osteotropic growth factors can be delivered to the site of injury. Expression of the gene effectively results in localised delivery of the growth factor. Delivery of cells having osteogenic potential can also result in bone formation. Furthermore, it may be possible to obtain additional benefits by combining biotherapeutic approaches, such as by introducing cells genetically modified to overexpress therapeutic proteins of interest. Although biotherapeutics have great potential for stimulating bone repair, only a limited number of treatments have been approved by governmental regulatory agencies for clinical use. Bone morphogenetic activity was initially described in 1965, but not until 2001 and 2002 did two protein biotherapeutics, utilising bone morphogenetic proteins 2 and 7, receive

  7. Acceleration of the GAMESS-UK electronic structure package on graphical processing units.

    PubMed

    Wilkinson, Karl A; Sherwood, Paul; Guest, Martyn F; Naidoo, Kevin J

    2011-07-30

    The approach used to calculate the two-electron integral by many electronic structure packages including generalized atomic and molecular electronic structure system-UK has been designed for CPU-based compute units. We redesigned the two-electron compute algorithm for acceleration on a graphical processing unit (GPU). We report the acceleration strategy and illustrate it on the (ss|ss) type integrals. This strategy is general for Fortran-based codes and uses the Accelerator compiler from Portland Group International and GPU-based accelerators from Nvidia. The evaluation of (ss|ss) type integrals within calculations using Hartree Fock ab initio methods and density functional theory are accelerated by single and quad GPU hardware systems by factors of 43 and 153, respectively. The overall speedup for a single self consistent field cycle is at least a factor of eight times faster on a single GPU compared with that of a single CPU. PMID:21541963

  8. Using pattern enumeration to accelerate process development and ramp yield

    NASA Astrophysics Data System (ADS)

    Zhuang, Linda; Pang, Jenny; Xu, Jessy; Tsai, Mengfeng; Wang, Amy; Zhang, Yifan; Sweis, Jason; Lai, Ya-Chieh; Ding, Hua

    2016-03-01

    During a new technology node process setup phase, foundries do not initially have enough product chip designs to conduct exhaustive process development. Different operational teams use manually designed simple test keys to set up their process flows and recipes. When the very first version of the design rule manual (DRM) is ready, foundries enter the process development phase where new experiment design data is manually created based on these design rules. However, these IP/test keys contain very uniform or simple design structures. This kind of design normally does not contain critical design structures or process unfriendly design patterns that pass design rule checks but are found to be less manufacturable. It is desired to have a method to generate exhaustive test patterns allowed by design rules at development stage to verify the gap of design rule and process. This paper presents a novel method of how to generate test key patterns which contain known problematic patterns as well as any constructs which designers could possibly draw based on current design rules. The enumerated test key patterns will contain the most critical design structures which are allowed by any particular design rule. A layout profiling method is used to do design chip analysis in order to find potential weak points on new incoming products so fab can take preemptive action to avoid yield loss. It can be achieved by comparing different products and leveraging the knowledge learned from previous manufactured chips to find possible yield detractors.

  9. Noninvasive imaging modalities to visualize atherosclerotic plaques

    PubMed Central

    2016-01-01

    Atherosclerotic cardiovascular disease is becoming a major cause of death in the world due to global epidemic of diabetes and obesity. For the prevention of atherosclerotic cardiovascular disease, it is necessary to detect high-risk atherosclerotic plaques prior to events. Recent technological advances enable to visualize atherosclerotic plaques noninvasively. This ability of noninvasive imaging helps to refine cardiovascular risk assessment in various individuals, select optimal therapeutic strategy and evaluate the efficacy of medical therapies. In this review, we discuss the role of the currently available imaging modalities including computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography. Advantages and disadvantages of each noninvasive imaging modality will be also summarized. PMID:27500092

  10. Adventitial inflammation and its interaction with intimal atherosclerotic lesions

    PubMed Central

    Akhavanpoor, Mohammadreza; Wangler, Susanne; Gleissner, Christian A.; Korosoglou, Grigorios; Katus, Hugo A.; Erbel, Christian

    2014-01-01

    The presence of adventitial inflammation in correlation with atherosclerotic lesions has been recognized for decades. In the last years, several studies have investigated the relevance and impact of adventitial inflammation on atherogenesis. In the abdominal aorta of elderly Apoe−/− mice, adventitial inflammatory structures were characterized as organized ectopic lymphoid tissue, and therefore termed adventitial tertiary lymphoid organs (ATLOs). These ATLOs possess similarities in development, structure and function to secondary lymphoid organs. A crosstalk between intimal atherosclerotic lesions and ATLOs has been suggested, and several studies could demonstrate a potential role for medial vascular smooth muscle cells in this process. We here review the development, phenotypic characteristics, and function of ATLOs in atherosclerosis. Furthermore, we discuss the possible role of medial vascular smooth muscle cells and their interaction between plaque and ATLOs. PMID:25152736

  11. Imaging Modalities to Identity Inflammation in an Atherosclerotic Plaque

    PubMed Central

    Goel, Sunny; Miller, Avraham; Agarwal, Chirag; Zakin, Elina; Acholonu, Michael; Gidwani, Umesh; Sharma, Abhishek; Kulbak, Guy; Shani, Jacob; Chen, On

    2015-01-01

    Atherosclerosis is a chronic, progressive, multifocal arterial wall disease caused by local and systemic inflammation responsible for major cardiovascular complications such as myocardial infarction and stroke. With the recent understanding that vulnerable plaque erosion and rupture, with subsequent thrombosis, rather than luminal stenosis, is the underlying cause of acute ischemic events, there has been a shift of focus to understand the mechanisms that make an atherosclerotic plaque unstable or vulnerable to rupture. The presence of inflammation in the atherosclerotic plaque has been considered as one of the initial events which convert a stable plaque into an unstable and vulnerable plaque. This paper systemically reviews the noninvasive and invasive imaging modalities that are currently available to detect this inflammatory process, at least in the intermediate stages, and discusses the ongoing studies that will help us to better understand and identify it at the molecular level. PMID:26798515

  12. Refining each process step to accelerate the development of biorefineries

    DOE PAGES

    Chandra, Richard P.; Ragauskas, Art J.

    2016-06-21

    Research over the past decade has been mainly focused on overcoming hurdles in the pretreatment, enzymatic hydrolysis, and fermentation steps of biochemical processing. Pretreatments have improved significantly in their ability to fractionate and recover the cellulose, hemicellulose, and lignin components of biomass while producing substrates containing carbohydrates that can be easily broken down by hydrolytic enzymes. There is a rapid movement towards pretreatment processes that incorporate mechanical treatments that make use of existing infrastructure in the pulp and paper industry, which has experienced a downturn in its traditional markets. Enzyme performance has also made great strides with breakthrough developments inmore » nonhydrolytic protein components, such as lytic polysaccharide monooxygenases, as well as the improvement of enzyme cocktails.The fermentability of pretreated and hydrolyzed sugar streams has been improved through strategies such as the use of reducing agents for detoxification, strain selection, and strain improvements. Although significant progress has been made, tremendous challenges still remain to advance each step of biochemical conversion, especially when processing woody biomass. In addition to technical and scale-up issues within each step of the bioconversion process, biomass feedstock supply and logistics challenges still remain at the forefront of biorefinery research.« less

  13. Accelerated space object tracking via graphic processing unit

    NASA Astrophysics Data System (ADS)

    Jia, Bin; Liu, Kui; Pham, Khanh; Blasch, Erik; Chen, Genshe

    2016-05-01

    In this paper, a hybrid Monte Carlo Gauss mixture Kalman filter is proposed for the continuous orbit estimation problem. Specifically, the graphic processing unit (GPU) aided Monte Carlo method is used to propagate the uncertainty of the estimation when the observation is not available and the Gauss mixture Kalman filter is used to update the estimation when the observation sequences are available. A typical space object tracking problem using the ground radar is used to test the performance of the proposed algorithm. The performance of the proposed algorithm is compared with the popular cubature Kalman filter (CKF). The simulation results show that the ordinary CKF diverges in 5 observation periods. In contrast, the proposed hybrid Monte Carlo Gauss mixture Kalman filter achieves satisfactory performance in all observation periods. In addition, by using the GPU, the computational time is over 100 times less than that using the conventional central processing unit (CPU).

  14. Accelerating radio astronomy cross-correlation with graphics processing units

    NASA Astrophysics Data System (ADS)

    Clark, M. A.; LaPlante, P. C.; Greenhill, L. J.

    2013-05-01

    We present a highly parallel implementation of the cross-correlation of time-series data using graphics processing units (GPUs), which is scalable to hundreds of independent inputs and suitable for the processing of signals from 'large-Formula' arrays of many radio antennas. The computational part of the algorithm, the X-engine, is implemented efficiently on NVIDIA's Fermi architecture, sustaining up to 79% of the peak single-precision floating-point throughput. We compare performance obtained for hardware- and software-managed caches, observing significantly better performance for the latter. The high performance reported involves use of a multi-level data tiling strategy in memory and use of a pipelined algorithm with simultaneous computation and transfer of data from host to device memory. The speed of code development, flexibility, and low cost of the GPU implementations compared with application-specific integrated circuit (ASIC) and field programmable gate array (FPGA) implementations have the potential to greatly shorten the cycle of correlator development and deployment, for cases where some power-consumption penalty can be tolerated.

  15. Graphics processing units accelerated semiclassical initial value representation molecular dynamics

    SciTech Connect

    Tamascelli, Dario; Dambrosio, Francesco Saverio; Conte, Riccardo; Ceotto, Michele

    2014-05-07

    This paper presents a Graphics Processing Units (GPUs) implementation of the Semiclassical Initial Value Representation (SC-IVR) propagator for vibrational molecular spectroscopy calculations. The time-averaging formulation of the SC-IVR for power spectrum calculations is employed. Details about the GPU implementation of the semiclassical code are provided. Four molecules with an increasing number of atoms are considered and the GPU-calculated vibrational frequencies perfectly match the benchmark values. The computational time scaling of two GPUs (NVIDIA Tesla C2075 and Kepler K20), respectively, versus two CPUs (Intel Core i5 and Intel Xeon E5-2687W) and the critical issues related to the GPU implementation are discussed. The resulting reduction in computational time and power consumption is significant and semiclassical GPU calculations are shown to be environment friendly.

  16. Graphics processing units accelerated semiclassical initial value representation molecular dynamics

    NASA Astrophysics Data System (ADS)

    Tamascelli, Dario; Dambrosio, Francesco Saverio; Conte, Riccardo; Ceotto, Michele

    2014-05-01

    This paper presents a Graphics Processing Units (GPUs) implementation of the Semiclassical Initial Value Representation (SC-IVR) propagator for vibrational molecular spectroscopy calculations. The time-averaging formulation of the SC-IVR for power spectrum calculations is employed. Details about the GPU implementation of the semiclassical code are provided. Four molecules with an increasing number of atoms are considered and the GPU-calculated vibrational frequencies perfectly match the benchmark values. The computational time scaling of two GPUs (NVIDIA Tesla C2075 and Kepler K20), respectively, versus two CPUs (Intel Core i5 and Intel Xeon E5-2687W) and the critical issues related to the GPU implementation are discussed. The resulting reduction in computational time and power consumption is significant and semiclassical GPU calculations are shown to be environment friendly.

  17. Graphics processing units accelerated semiclassical initial value representation molecular dynamics.

    PubMed

    Tamascelli, Dario; Dambrosio, Francesco Saverio; Conte, Riccardo; Ceotto, Michele

    2014-05-01

    This paper presents a Graphics Processing Units (GPUs) implementation of the Semiclassical Initial Value Representation (SC-IVR) propagator for vibrational molecular spectroscopy calculations. The time-averaging formulation of the SC-IVR for power spectrum calculations is employed. Details about the GPU implementation of the semiclassical code are provided. Four molecules with an increasing number of atoms are considered and the GPU-calculated vibrational frequencies perfectly match the benchmark values. The computational time scaling of two GPUs (NVIDIA Tesla C2075 and Kepler K20), respectively, versus two CPUs (Intel Core i5 and Intel Xeon E5-2687W) and the critical issues related to the GPU implementation are discussed. The resulting reduction in computational time and power consumption is significant and semiclassical GPU calculations are shown to be environment friendly. PMID:24811627

  18. Accelerating the scientific exploration process with scientific workflows

    NASA Astrophysics Data System (ADS)

    Altintas, Ilkay; Barney, Oscar; Cheng, Zhengang; Critchlow, Terence; Ludaescher, Bertram; Parker, Steve; Shoshani, Arie; Vouk, Mladen

    2006-09-01

    Although an increasing amount of middleware has emerged in the last few years to achieve remote data access, distributed job execution, and data management, orchestrating these technologies with minimal overhead still remains a difficult task for scientists. Scientific workflow systems improve this situation by creating interfaces to a variety of technologies and automating the execution and monitoring of the workflows. Workflow systems provide domain-independent customizable interfaces and tools that combine different tools and technologies along with efficient methods for using them. As simulations and experiments move into the petascale regime, the orchestration of long running data and compute intensive tasks is becoming a major requirement for the successful steering and completion of scientific investigations. A scientific workflow is the process of combining data and processes into a configurable, structured set of steps that implement semi-automated computational solutions of a scientific problem. Kepler is a cross-project collaboration, co-founded by the SciDAC Scientific Data Management (SDM) Center, whose purpose is to develop a domain-independent scientific workflow system. It provides a workflow environment in which scientists design and execute scientific workflows by specifying the desired sequence of computational actions and the appropriate data flow, including required data transformations, between these steps. Currently deployed workflows range from local analytical pipelines to distributed, high-performance and high-throughput applications, which can be both data- and compute-intensive. The scientific workflow approach offers a number of advantages over traditional scripting-based approaches, including ease of configuration, improved reusability and maintenance of workflows and components (called actors), automated provenance management, ''smart'' re-running of different versions of workflow instances, on-the-fly updateable parameters

  19. Using Qualitative Observation To Document Group Processes in Accelerated Schools Training: Techniques and Results.

    ERIC Educational Resources Information Center

    McFarland, Katherine; Batten, Constance

    This paper describes the use of qualitative observation techniques for gathering and analyzing data related to group processes during an Accelerated Schools Model training session. The purposes for this research were to observe the training process in order better to facilitate present continuation and future training, to develop questions for…

  20. Accelerator Production of Tritium project process waste assessment

    SciTech Connect

    Carson, S.D.; Peterson, P.K.

    1995-09-01

    DOE has made a commitment to compliance with all applicable environmental regulatory requirements. In this respect, it is important to consider and design all tritium supply alternatives so that they can comply with these requirements. The management of waste is an integral part of this activity and it is therefore necessary to estimate the quantities and specific wastes that will be generated by all tritium supply alternatives. A thorough assessment of waste streams includes waste characterization, quantification, and the identification of treatment and disposal options. The waste assessment for APT has been covered in two reports. The first report was a process waste assessment (PWA) that identified and quantified waste streams associated with both target designs and fulfilled the requirements of APT Work Breakdown Structure (WBS) Item 5.5.2.1. This second report is an expanded version of the first that includes all of the data of the first report, plus an assessment of treatment and disposal options for each waste stream identified in the initial report. The latter information was initially planned to be issued as a separate Waste Treatment and Disposal Options Assessment Report (WBS Item 5.5.2.2).

  1. Alginate-hyaluronan composite hydrogels accelerate wound healing process.

    PubMed

    Catanzano, O; D'Esposito, V; Acierno, S; Ambrosio, M R; De Caro, C; Avagliano, C; Russo, P; Russo, R; Miro, A; Ungaro, F; Calignano, A; Formisano, P; Quaglia, F

    2015-10-20

    In this paper we propose polysaccharide hydrogels combining alginate (ALG) and hyaluronan (HA) as biofunctional platform for dermal wound repair. Hydrogels produced by internal gelation were homogeneous and easy to handle. Rheological evaluation of gelation kinetics of ALG/HA mixtures at different ratios allowed understanding the HA effect on ALG cross-linking process. Disk-shaped hydrogels, at different ALG/HA ratio, were characterized for morphology, homogeneity and mechanical properties. Results suggest that, although the presence of HA does significantly slow down gelation kinetics, the concentration of cross-links reached at the end of gelation is scarcely affected. The in vitro activity of ALG/HA dressings was tested on adipose derived multipotent adult stem cells (Ad-MSC) and an immortalized keratinocyte cell line (HaCaT). Hydrogels did not interfere with cell viability in both cells lines, but significantly promoted gap closure in a scratch assay at early (1 day) and late (5 days) stages as compared to hydrogels made of ALG alone (p<0.01 and 0.001 for Ad-MSC and HaCaT, respectively). In vivo wound healing studies, conducted on a rat model of excised wound indicated that after 5 days ALG/HA hydrogels significantly promoted wound closure as compared to ALG ones (p<0.001). Overall results demonstrate that the integration of HA in a physically cross-linked ALG hydrogel can be a versatile strategy to promote wound healing that can be easily translated in a clinical setting.

  2. Progression and regression of the atherosclerotic plaque.

    PubMed

    de Feyter, P J; Vos, J; Deckers, J W

    1995-08-01

    In animals in which atherosclerosis was induced experimentally (by a high cholesterol diet) regression of the atherosclerotic lesion was demonstrated after serum cholesterol was reduced by cholesterol- lowering drugs or a low-fat diet. Whether regression of advanced coronary arterly lesions also takes place in humans after a similar intervention remains conjectural. However, several randomized studies, primarily employing lipid-lowering intervention or comprehensive changes in lifestyle, have demonstrated, using serial angiograms, that it is possible to achieve less progression, arrest or even (small) regression of atherosclerotic lesions. The lipid-lowering trials (NHBLI, CLAS, POSCH, FATS, SCOR and STARS) studied 1240 symptomatic patients, mostly men, with moderately elevated cholesterol levels and moderately severe angiographic-proven coronary artery disease. A variety of lipid-lowering drugs, in addition to a diet, were used over an intervention period ranging from 2 to 3 years. In all but one study (NHBLI), the progression of coronary atherosclerosis was less in the treated group, but regression was induced in only a few patients. The overall relative risk of progression of coronary atherosclerosis was 0 x 62 and 2 x 13, respectively. The induced angiographic differences were small and did not produce any significant haemodynamic benefit. The most important result was tht the disease process could be stabilized in the majority of patients. Three comprehensive lifestyle change trials (the Lifestyle Heart study, STARS and the Heidelberg Study) studied 183 patients, who were subjected to stress management, and/or intensive exercise, in addition to a low fat diet, over a period ranging from 1 to 3 years. All three trials demonstrated less progression, and more regression with overall relative risks of 0 x 40 and 2 x 35 respectively, in the intervention groups. Angiographic trials demonstrated that retardation or arrest of coronary atherosclerosis was possible

  3. Swarm accelerometer data processing from raw accelerations to thermospheric neutral densities

    NASA Astrophysics Data System (ADS)

    Siemes, Christian; de Teixeira da Encarnação, João; Doornbos, Eelco; van den IJssel, Jose; Kraus, Jiří; Pereštý, Radek; Grunwaldt, Ludwig; Apelbaum, Guy; Flury, Jakob; Holmdahl Olsen, Poul Erik

    2016-05-01

    The Swarm satellites were launched on November 22, 2013, and carry accelerometers and GPS receivers as part of their scientific payload. The GPS receivers do not only provide the position and time for the magnetic field measurements, but are also used for determining non-gravitational forces like drag and radiation pressure acting on the spacecraft. The accelerometers measure these forces directly, at much finer resolution than the GPS receivers, from which thermospheric neutral densities can be derived. Unfortunately, the acceleration measurements suffer from a variety of disturbances, the most prominent being slow temperature-induced bias variations and sudden bias changes. In this paper, we describe the new, improved four-stage processing that is applied for transforming the disturbed acceleration measurements into scientifically valuable thermospheric neutral densities. In the first stage, the sudden bias changes in the acceleration measurements are manually removed using a dedicated software tool. The second stage is the calibration of the accelerometer measurements against the non-gravitational accelerations derived from the GPS receiver, which includes the correction for the slow temperature-induced bias variations. The identification of validity periods for calibration and correction parameters is part of the second stage. In the third stage, the calibrated and corrected accelerations are merged with the non-gravitational accelerations derived from the observations of the GPS receiver by a weighted average in the spectral domain, where the weights depend on the frequency. The fourth stage consists of transforming the corrected and calibrated accelerations into thermospheric neutral densities. We present the first results of the processing of Swarm C acceleration measurements from June 2014 to May 2015. We started with Swarm C because its acceleration measurements contain much less disturbances than those of Swarm A and have a higher signal-to-noise ratio

  4. FAST Observations of Acceleration Processes in the Cusp--Evidence for Parallel Electric Fields

    NASA Technical Reports Server (NTRS)

    Pfaff, R. F.. Jr.; Carlson, C.; McFadden, J.; Ergun, R.; Clemmons, J.; Klumpar D.; Strangeway, R.

    1999-01-01

    The existence of precipitating keV ions in the Earth's cusp originating at the magnetosheath provide unique means to test our understanding of particle acceleration and parallel electric fields in the lower altitude acceleration region. On numerous occasions, the FAST (The Fast Auroral Snapshot) spacecraft has encountered the Earth's cusp regions near its apogee of 4175 km which are characterized by their signatures of dispersed keV ion injections. The FAST instruments also reveal a complex microphysics inherent to many, but not all, of the cusp regions encountered by the spacecraft, that include upgoing ion beams and conics, inverted-V electrons, upgoing electron beams, and spikey DC-coupled electric fields and plasma waves. Detailed inspection of the FAST data often show clear modulation of the precipitating magnetosheath ions that indicate that they are affected by local electric potentials. For example, the magnetosheath ion precipitation is sometimes abruptly shut off precisely in regions where downgoing localized inverted-V electrons are observed. Such observations support the existence of a localized process, such as parallel electric fields, above the spacecraft which accelerate the electrons downward and consequently impede the precipitating ion precipitation. Other acceleration events in the cusp are sometimes organized with an apparent cellular structure that suggests Alfven waves or other large-scale phenomena are controlling the localized potentials. We examine several cusp encounters by the FAST satellite where the modulation of energetic session on acceleration particle populations reveals evidence of localized acceleration, most likely by parallel electric fields.

  5. Quasi-steady stages in the process of premixed flame acceleration in narrow channels

    NASA Astrophysics Data System (ADS)

    Valiev, D. M.; Bychkov, V.; Akkerman, V.; Eriksson, L.-E.; Law, C. K.

    2013-09-01

    The present paper addresses the phenomenon of spontaneous acceleration of a premixed flame front propagating in micro-channels, with subsequent deflagration-to-detonation transition. It has recently been shown experimentally [M. Wu, M. Burke, S. Son, and R. Yetter, Proc. Combust. Inst. 31, 2429 (2007)], 10.1016/j.proci.2006.08.098, computationally [D. Valiev, V. Bychkov, V. Akkerman, and L.-E. Eriksson, Phys. Rev. E 80, 036317 (2009)], 10.1103/PhysRevE.80.036317, and analytically [V. Bychkov, V. Akkerman, D. Valiev, and C. K. Law, Phys. Rev. E 81, 026309 (2010)], 10.1103/PhysRevE.81.026309 that the flame acceleration undergoes different stages, from an initial exponential regime to quasi-steady fast deflagration with saturated velocity. The present work focuses on the final saturation stages in the process of flame acceleration, when the flame propagates with supersonic velocity with respect to the channel walls. It is shown that an intermediate stage may occur during acceleration with quasi-steady velocity, noticeably below the Chapman-Jouguet deflagration speed. The intermediate stage is followed by additional flame acceleration and subsequent saturation to the Chapman-Jouguet deflagration regime. We elucidate the intermediate stage by the joint effect of gas pre-compression ahead of the flame front and the hydraulic resistance. The additional acceleration is related to viscous heating at the channel walls, being of key importance at the final stages. The possibility of explosion triggering is also demonstrated.

  6. Acceleration of Early-Photon Fluorescence Molecular Tomography with Graphics Processing Units

    PubMed Central

    Wang, Xin; Zhang, Bin; Cao, Xu; Liu, Fei; Luo, Jianwen; Bai, Jing

    2013-01-01

    Fluorescence molecular tomography (FMT) with early-photons can improve the spatial resolution and fidelity of the reconstructed results. However, its computing scale is always large which limits its applications. In this paper, we introduced an acceleration strategy for the early-photon FMT with graphics processing units (GPUs). According to the procedure, the whole solution of FMT was divided into several modules and the time consumption for each module is studied. In this strategy, two most time consuming modules (Gd and W modules) were accelerated with GPU, respectively, while the other modules remained coded in the Matlab. Several simulation studies with a heterogeneous digital mouse atlas were performed to confirm the performance of the acceleration strategy. The results confirmed the feasibility of the strategy and showed that the processing speed was improved significantly. PMID:23606899

  7. [Atherosclerotic renal artery disease management update].

    PubMed

    Meier, Pascal; Haesler, Erik; Teta, Daniel; Qanadli, Salah Dine; Burnier, Michel

    2009-02-01

    In the case of atherosclerotic renal artery disease, the best conclusive results lie principally not in the degree of the stenosis but rather in the degree the renal parenchymal disease beyond the stenosis itself. These determining factors involve the controlling of the patients blood pressure, the improvement in the renal function and the beneficial results to the cardiovascular system. Besides the indispensable medical treatment, a revascularisation by angioplasty may be indicated. This procedure with or without vascular stent often allows satisfactory angiographic results. A treatment by surgical revascularisation is only recommended in the case of extensive atherosclerotic lesions of the aorta, complex lesions of the latter or an abdominal aortic aneurism. Although the frequency of restenosis of angioplasty with stent remains extremely low, the risk of cholesterol emboli due to the diffuse atherosclerotic lesions of the abdominal aorta, must be considered at the time of each aortic catheterization. The therapeutic approach of atherosclerotic renal artery disease must be dictated by the whole cardiovascular risk factors and by the threat of target organs. The control of the blood pressure and the maintenance of the renal function must be integrated in the decisional algorithm as well as the possible risks in carrying out an eventual revascularisation procedure. Finally, the renal angioplasty should in numerous situations be integrated in the overall assumption of responsibility of the atherosclerotic vascular diseases, and should be part of the medical treatment. Several questions still do exist; at what moment an atherosclerotic renal artery stenosis should and e considered critical, and which procedure should be considered for which patient? The purpose of this review is to propose a decisional tool for individualized treatments in the light of results from randomized and controlled studies. PMID:18815087

  8. [Atherosclerotic renal artery disease management update].

    PubMed

    Meier, Pascal; Haesler, Erik; Teta, Daniel; Qanadli, Salah Dine; Burnier, Michel

    2009-02-01

    In the case of atherosclerotic renal artery disease, the best conclusive results lie principally not in the degree of the stenosis but rather in the degree the renal parenchymal disease beyond the stenosis itself. These determining factors involve the controlling of the patients blood pressure, the improvement in the renal function and the beneficial results to the cardiovascular system. Besides the indispensable medical treatment, a revascularisation by angioplasty may be indicated. This procedure with or without vascular stent often allows satisfactory angiographic results. A treatment by surgical revascularisation is only recommended in the case of extensive atherosclerotic lesions of the aorta, complex lesions of the latter or an abdominal aortic aneurism. Although the frequency of restenosis of angioplasty with stent remains extremely low, the risk of cholesterol emboli due to the diffuse atherosclerotic lesions of the abdominal aorta, must be considered at the time of each aortic catheterization. The therapeutic approach of atherosclerotic renal artery disease must be dictated by the whole cardiovascular risk factors and by the threat of target organs. The control of the blood pressure and the maintenance of the renal function must be integrated in the decisional algorithm as well as the possible risks in carrying out an eventual revascularisation procedure. Finally, the renal angioplasty should in numerous situations be integrated in the overall assumption of responsibility of the atherosclerotic vascular diseases, and should be part of the medical treatment. Several questions still do exist; at what moment an atherosclerotic renal artery stenosis should and e considered critical, and which procedure should be considered for which patient? The purpose of this review is to propose a decisional tool for individualized treatments in the light of results from randomized and controlled studies.

  9. Electron studies of acceleration processes in the corona. [solar probe mission planning

    NASA Technical Reports Server (NTRS)

    Lin, R. P.

    1978-01-01

    The solar probe mission can obtain unique and crucially important measurements of electron acceleration, storage, and propagation processes in the corona and can probe the magnetic field structure of the corona below the spacecraft. The various energetic electron phenomena which will be sampled by the Solar Probe are described and some new techniques to probe coronal structures are suggested.

  10. Nanomanufacturing Portfolio: Manufacturing Processes and Applications to Accelerate Commercial Use of Nanomaterials

    SciTech Connect

    Industrial Technologies Program

    2011-01-05

    This brochure describes the 31 R&D projects that AMO supports to accelerate the commercial manufacture and use of nanomaterials for enhanced energy efficiency. These cost-shared projects seek to exploit the unique properties of nanomaterials to improve the functionality of industrial processes and products.

  11. Sampling frequency affects the processing of Actigraph raw acceleration data to activity counts.

    PubMed

    Brønd, Jan Christian; Arvidsson, Daniel

    2016-02-01

    ActiGraph acceleration data are processed through several steps (including band-pass filtering to attenuate unwanted signal frequencies) to generate the activity counts commonly used in physical activity research. We performed three experiments to investigate the effect of sampling frequency on the generation of activity counts. Ideal acceleration signals were produced in the MATLAB software. Thereafter, ActiGraph GT3X+ monitors were spun in a mechanical setup. Finally, 20 subjects performed walking and running wearing GT3X+ monitors. Acceleration data from all experiments were collected with different sampling frequencies, and activity counts were generated with the ActiLife software. With the default 30-Hz (or 60-Hz, 90-Hz) sampling frequency, the generation of activity counts was performed as intended with 50% attenuation of acceleration signals with a frequency of 2.5 Hz by the signal frequency band-pass filter. Frequencies above 5 Hz were eliminated totally. However, with other sampling frequencies, acceleration signals above 5 Hz escaped the band-pass filter to a varied degree and contributed to additional activity counts. Similar results were found for the spinning of the GT3X+ monitors, although the amount of activity counts generated was less, indicating that raw data stored in the GT3X+ monitor is processed. Between 600 and 1,600 more counts per minute were generated with the sampling frequencies 40 and 100 Hz compared with 30 Hz during running. Sampling frequency affects the processing of ActiGraph acceleration data to activity counts. Researchers need to be aware of this error when selecting sampling frequencies other than the default 30 Hz.

  12. Graphics processing unit-accelerated double random phase encoding for fast image encryption

    NASA Astrophysics Data System (ADS)

    Lee, Jieun; Yi, Faliu; Saifullah, Rao; Moon, Inkyu

    2014-11-01

    We propose a fast double random phase encoding (DRPE) algorithm using a graphics processing unit (GPU)-based stream-processing model. A performance analysis of the accelerated DRPE implementation that employs the Compute Unified Device Architecture programming environment is presented. We show that the proposed methodology executed on a GPU can dramatically increase encryption speed compared with central processing unit sequential computing. Our experimental results demonstrate that in encryption data of an image with a pixel size of 1000×1000, where one pixel has a 32-bit depth, our GPU version of the DRPE scheme can be approximately two times faster than the advanced encryption standard algorithm implemented on a GPU. In addition, the quality of parallel processing on the presented DRPE acceleration method is evaluated with performance parameters, such as speedup, efficiency, and redundancy.

  13. Risk-Based Decision Process for Accelerated Closure of a Nuclear Weapons Facility

    SciTech Connect

    Butler, L.; Norland, R. L.; DiSalvo, R.; Anderson, M.

    2003-02-25

    Nearly 40 years of nuclear weapons production at the Rocky Flats Environmental Technology Site (RFETS or Site) resulted in contamination of soil and underground systems and structures with hazardous substances, including plutonium, uranium and hazardous waste constituents. The Site was placed on the National Priority List in 1989. There are more than 370 Individual Hazardous Substance Sites (IHSSs) at RFETS. Accelerated cleanup and closure of RFETS is being achieved through implementation and refinement of a regulatory framework that fosters programmatic and technical innovations: (1) extensive use of ''accelerated actions'' to remediate IHSSs, (2) development of a risk-based screening process that triggers and helps define the scope of accelerated actions consistent with the final remedial action objectives for the Site, (3) use of field instrumentation for real time data collection, (4) a data management system that renders near real time field data assessment, and (5) a regulatory agency consultative process to facilitate timely decisions. This paper presents the process and interim results for these aspects of the accelerated closure program applied to Environmental Restoration activities at the Site.

  14. Recent developments in the application of electron accelerators for polymer processing

    NASA Astrophysics Data System (ADS)

    Chmielewski, A. G.; Al-Sheikhly, M.; Berejka, A. J.; Cleland, M. R.; Antoniak, M.

    2014-01-01

    There are now over 1700 high current, electron beam (EB) accelerators being used world-wide in industrial applications, most of which involve polymer processing. In contrast to the use of heat, which transfers only about 5-10% of input energy into energy useful for materials modification, radiation processing is very energy efficient, with 60% or more of the input energy to an accelerator being available for affecting materials. Historic markets, such as the crosslinking of wire and cable jacketing, of heat shrinkable tubings and films, of partial crosslinking of tire components and of low-energy EB to cure or dry inks and coatings remain strong. Accelerator manufacturers have made equipment more affordable by down-sizing units while maintaining high beam currents. Very powerful accelerators with 700 kW output have made X-ray conversion a practical alternative to the historic use of radioisotopes, mainly cobalt-60, for applications as medical device sterilization. New EB end-uses are emerging, such as the development of nano-composites and nano-gels and the use of EB processing to facilitate biofuel production. These present opportunities for future research and development.

  15. Acceleration processes in the quasi-steady magnetoplasmadynamic discharge. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Boyle, M. J.

    1974-01-01

    The flow field characteristics within the discharge chamber and exhaust of a quasi-steady magnetoplasmadynamic (MPD) arcjet were examined to clarify the nature of the plasma acceleration process. The observation of discharge characteristics unperturbed by insulator ablation and terminal voltage fluctuations, first requires the satisfaction of three criteria: the use of refractory insulator materials; a mass injection geometry tailored to provide propellant to both electrode regions of the discharge; and a cathode of sufficient surface area to permit nominal MPD arcjet operation for given combinations of arc current and total mass flow. The axial velocity profile and electromagnetic discharge structure were measured for an arcjet configuration which functions nominally at 15.3 kA and 6 g/sec argon mass flow. An empirical two-flow plasma acceleration model is advanced which delineates inner and outer flow regions and accounts for the observed velocity profile and calculated thrust of the accelerator.

  16. General description of electromagnetic radiation processes based on instantaneous charge acceleration in ''endpoints''

    SciTech Connect

    James, Clancy W.; Falcke, Heino; Huege, Tim; Ludwig, Marianne

    2011-11-15

    We present a methodology for calculating the electromagnetic radiation from accelerated charged particles. Our formulation - the 'endpoint formulation' - combines numerous results developed in the literature in relation to radiation arising from particle acceleration using a complete, and completely general, treatment. We do this by describing particle motion via a series of discrete, instantaneous acceleration events, or 'endpoints', with each such event being treated as a source of emission. This method implicitly allows for particle creation and destruction, and is suited to direct numerical implementation in either the time or frequency domains. In this paper we demonstrate the complete generality of our method for calculating the radiated field from charged particle acceleration, and show how it reduces to the classical named radiation processes such as synchrotron, Tamm's description of Vavilov-Cherenkov, and transition radiation under appropriate limits. Using this formulation, we are immediately able to answer outstanding questions regarding the phenomenology of radio emission from ultra-high-energy particle interactions in both the earth's atmosphere and the moon. In particular, our formulation makes it apparent that the dominant emission component of the Askaryan effect (coherent radio-wave radiation from high-energy particle cascades in dense media) comes from coherent 'bremsstrahlung' from particle acceleration, rather than coherent Vavilov-Cherenkov radiation.

  17. Lipidome of atherosclerotic plaques from hypercholesterolemic rabbits.

    PubMed

    Bojic, Lazar A; McLaren, David G; Shah, Vinit; Previs, Stephen F; Johns, Douglas G; Castro-Perez, Jose M

    2014-12-15

    The cellular, macromolecular and neutral lipid composition of the atherosclerotic plaque has been extensively characterized. However, a comprehensive lipidomic analysis of the major lipid classes within atherosclerotic lesions has not been reported. The objective of this study was to produce a detailed framework of the lipids that comprise the atherosclerotic lesion of a widely used pre-clinical model of plaque progression. Male New Zealand White rabbits were administered regular chow supplemented with 0.5% cholesterol (HC) for 12 weeks to induce hypercholesterolemia and atherosclerosis. Our lipidomic analyses of plaques isolated from rabbits fed the HC diet, using ultra-performance liquid chromatography (UPLC) and high-resolution mass spectrometry, detected most of the major lipid classes including: Cholesteryl esters, triacylglycerols, phosphatidylcholines, sphingomyelins, diacylglycerols, fatty acids, phosphatidylserines, lysophosphatidylcholines, ceramides, phosphatidylglycerols, phosphatidylinositols and phosphatidylethanolamines. Given that cholesteryl esters, triacylglycerols and phosphatidylcholines comprise greater than 75% of total plasma lipids, we directed particular attention towards the qualitative and quantitative assessment of the fatty acid composition of these lipids. We additionally found that sphingomyelins were relatively abundant lipid class within lesions, and compared the abundance of sphingomyelins to their precursor phosphatidylcholines. The studies presented here are the first approach to a comprehensive characterization of the atherosclerotic plaque lipidome.

  18. Lipidome of Atherosclerotic Plaques from Hypercholesterolemic Rabbits

    PubMed Central

    Bojic, Lazar A.; McLaren, David G.; Shah, Vinit; Previs, Stephen F.; Johns, Douglas G.; Castro-Perez, Jose M.

    2014-01-01

    The cellular, macromolecular and neutral lipid composition of the atherosclerotic plaque has been extensively characterized. However, a comprehensive lipidomic analysis of the major lipid classes within atherosclerotic lesions has not been reported. The objective of this study was to produce a detailed framework of the lipids that comprise the atherosclerotic lesion of a widely used pre-clinical model of plaque progression. Male New Zealand White rabbits were administered regular chow supplemented with 0.5% cholesterol (HC) for 12 weeks to induce hypercholesterolemia and atherosclerosis. Our lipidomic analyses of plaques isolated from rabbits fed the HC diet, using ultra-performance liquid chromatography (UPLC) and high-resolution mass spectrometry, detected most of the major lipid classes including: Cholesteryl esters, triacylglycerols, phosphatidylcholines, sphingomyelins, diacylglycerols, fatty acids, phosphatidylserines, lysophosphatidylcholines, ceramides, phosphatidylglycerols, phosphatidylinositols and phosphatidylethanolamines. Given that cholesteryl esters, triacylglycerols and phosphatidylcholines comprise greater than 75% of total plasma lipids, we directed particular attention towards the qualitative and quantitative assessment of the fatty acid composition of these lipids. We additionally found that sphingomyelins were relatively abundant lipid class within lesions, and compared the abundance of sphingomyelins to their precursor phosphatidylcholines. The studies presented here are the first approach to a comprehensive characterization of the atherosclerotic plaque lipidome. PMID:25517033

  19. Ultrasound Tissue Characterization of Vulnerable Atherosclerotic Plaque

    PubMed Central

    Picano, Eugenio; Paterni, Marco

    2015-01-01

    A thrombotic occlusion of the vessel fed by ruptured coronary atherosclerotic plaque may result in unstable angina, myocardial infarction or death, whereas embolization from a plaque in carotid arteries may result in transient ischemic attack or stroke. The atherosclerotic plaque prone to such clinical events is termed high-risk or vulnerable plaque, and its identification in humans before it becomes symptomatic has been elusive to date. Ultrasonic tissue characterization of the atherosclerotic plaque is possible with different techniques—such as vascular, transesophageal, and intravascular ultrasound—on a variety of arterial segments, including carotid, aorta, and coronary districts. The image analysis can be based on visual, video-densitometric or radiofrequency methods and identifies three distinct textural patterns: hypo-echoic (corresponding to lipid- and hemorrhage-rich plaque), iso- or moderately hyper-echoic (fibrotic or fibro-fatty plaque), and markedly hyperechoic with shadowing (calcific plaque). Hypoechoic or dishomogeneous plaques, with spotty microcalcification and large plaque burden, with plaque neovascularization and surface irregularities by contrast-enhanced ultrasound, are more prone to clinical complications than hyperechoic, extensively calcified, homogeneous plaques with limited plaque burden, smooth luminal plaque surface and absence of neovascularization. Plaque ultrasound morphology is important, along with plaque geometry, in determining the atherosclerotic prognostic burden in the individual patient. New quantitative methods beyond backscatter (to include speed of sound, attenuation, strain, temperature, and high order statistics) are under development to evaluate vascular tissues. Although not yet ready for widespread clinical use, tissue characterization is listed by the American Society of Echocardiography roadmap to 2020 as one of the most promising fields of application in cardiovascular ultrasound imaging, offering unique

  20. Challenges Encountered during the Processing of the BNL ERL 5 Cell Accelerating Cavity

    SciTech Connect

    A. Burrill; I. Ben-Zvi; R. Calaga; H. Hahn; V. Litvinenko; G. T. McIntyre; P. Kneisel; J. Mammosser; J. P. Preble; C. E. Reece; R. A. Rimmer; J. Saunders

    2007-08-01

    One of the key components for the Energy Recovery Linac being built by the Electron cooling group in the Collider Accelerator Department is the 5 cell accelerating cavity which is designed to accelerate 2 MeV electrons from the gun up to 15-20 MeV, allow them to make one pass through the ring and then decelerate them back down to 2 MeV prior to sending them to the dump. This cavity was designed by BNL and fabricated by AES in Medford, NY. Following fabrication it was sent to Thomas Jefferson Lab in VA for chemical processing, testing and assembly into a string assembly suitable for shipment back to BNL and integration into the ERL. The steps involved in this processing sequence will be reviewed and the deviations from processing of similar SRF cavities will be discussed. The lessons learned from this process are documented to help future projects where the scope is different from that normally encountered.

  1. Distinguishing Between Quasi-static and Alfvénic Auroral Acceleration Processes

    NASA Astrophysics Data System (ADS)

    Lysak, R. L.; Song, Y.

    2013-12-01

    Models for the acceleration of auroral particles fall into two general classes. Quasi-static processes, such as double layers or magnetic mirror supported potential drops, produce a nearly monoenergetic beam of precipitating electrons and upward flowing ion beams. Time-dependent acceleration processes, often associated with kinetic Alfvén waves, can produce a broader range of energies and often have a strongly field-aligned pitch angle distribution. Both processes are associated with strong perpendicular electric fields as well as the parallel electric fields that are largely responsible for the particle acceleration. These electric fields and the related magnetic perturbations can be characterized by the ratio of the electric field to a perpendicular magnetic perturbation, which is related to the Pedersen conductivity in the static case and the Alfvén velocity in the time-dependent case. However, these considerations can be complicated by the interaction between upward and downward propagating waves. The relevant time and space scales of these processes will be assessed and the consequences for observation by orbiting spacecraft and ground-based instrumentation will be determined. These features will be illustrated by numerical simulations of the magnetosphere-ionosphere coupling with emphasis on what a virtual spacecraft passing through the simulation would be expected to observe.

  2. Acceleration of integral imaging based incoherent Fourier hologram capture using graphic processing unit.

    PubMed

    Jeong, Kyeong-Min; Kim, Hee-Seung; Hong, Sung-In; Lee, Sung-Keun; Jo, Na-Young; Kim, Yong-Soo; Lim, Hong-Gi; Park, Jae-Hyeung

    2012-10-01

    Speed enhancement of integral imaging based incoherent Fourier hologram capture using a graphic processing unit is reported. Integral imaging based method enables exact hologram capture of real-existing three-dimensional objects under regular incoherent illumination. In our implementation, we apply parallel computation scheme using the graphic processing unit, accelerating the processing speed. Using enhanced speed of hologram capture, we also implement a pseudo real-time hologram capture and optical reconstruction system. The overall operation speed is measured to be 1 frame per second.

  3. Hardware accelerator of convolution with exponential function for image processing applications

    NASA Astrophysics Data System (ADS)

    Panchenko, Ivan; Bucha, Victor

    2015-12-01

    In this paper we describe a Hardware Accelerator (HWA) for fast recursive approximation of separable convolution with exponential function. This filter can be used in many Image Processing (IP) applications, e.g. depth-dependent image blur, image enhancement and disparity estimation. We have adopted this filter RTL implementation to provide maximum throughput in constrains of required memory bandwidth and hardware resources to provide a power-efficient VLSI implementation.

  4. Accelerating frequency-domain diffuse optical tomographic image reconstruction using graphics processing units.

    PubMed

    Prakash, Jaya; Chandrasekharan, Venkittarayan; Upendra, Vishwajith; Yalavarthy, Phaneendra K

    2010-01-01

    Diffuse optical tomographic image reconstruction uses advanced numerical models that are computationally costly to be implemented in the real time. The graphics processing units (GPUs) offer desktop massive parallelization that can accelerate these computations. An open-source GPU-accelerated linear algebra library package is used to compute the most intensive matrix-matrix calculations and matrix decompositions that are used in solving the system of linear equations. These open-source functions were integrated into the existing frequency-domain diffuse optical image reconstruction algorithms to evaluate the acceleration capability of the GPUs (NVIDIA Tesla C 1060) with increasing reconstruction problem sizes. These studies indicate that single precision computations are sufficient for diffuse optical tomographic image reconstruction. The acceleration per iteration can be up to 40, using GPUs compared to traditional CPUs in case of three-dimensional reconstruction, where the reconstruction problem is more underdetermined, making the GPUs more attractive in the clinical settings. The current limitation of these GPUs in the available onboard memory (4 GB) that restricts the reconstruction of a large set of optical parameters, more than 13,377.

  5. The contemporary management of intracranial atherosclerotic disease.

    PubMed

    Leng, Xinyi; Wong, Ka Sing; Leung, Thomas W

    2016-06-01

    Intracranial atherosclerotic disease is the most common cause of cerebral vasculopathy and an important stroke etiology worldwide, with a higher prevalence in Asian, Hispanic and African ethnicities. Symptomatic intracranial atherosclerotic disease portends a recurrent stroke risk as high as 18% at one year. The key to secondary prevention is an understanding of the underlying stroke mechanism and aggressive control of conventional cardiovascular risks. Contemporary treatment includes antiplatelet therapy, optimal glycemic and blood pressure control, statin therapy and lifestyle modifications. For patients with high-grade (70-99%) symptomatic steno-occlusion, short-term dual antiplatelet therapy with aspirin and clopidogrel followed by life-long single antiplatelet therapy may reduce the recurrent risk. Current evidence does not advocate percutaneous transluminal angioplasty and stenting as an initial treatment. External counterpulsation, encephaloduroarteriosynangiosis and remote limb ischemic preconditioning are treatments under investigation. Future studies should aim at predicting patients prone to recurrence despite of medical therapies and testing the efficacy of emerging therapies.

  6. Biobanking in Atherosclerotic Disease, Opportunities and Pitfalls

    PubMed Central

    Scholtes, V.P.W; de Vries, J.P.P.M; Catanzariti, L.M; de Kleijn, D.P.V; Moll, F.L; de Borst, G.J; Pasterkamp, G

    2011-01-01

    Cardiovascular disease is the leading cause of death in Western countries and current research is still focusing on optimizing therapeutic approaches in the battle against this multifactorial disease. Concepts regarding the pathogenesis of many cardiovascular diseases originate from observations of human atherosclerotic tissue obtained from autopsies or during vascular surgery. These observations have helped us to disentangle the pathophysiology of atherosclerosis. However, identifying vulnerable patients, those prone to developing cardiovascular complications, remains difficult. The search for predictive cardiovascular biomarkers continues and large, well organized biobanks are needed to discover or validate novel biomarkers. Biobanks are an extremely valuable resource that enables us to study the influence of both genetic and environmental factors on the development of multifactorial diseases such as atherosclerosis. This review will focus on the advantages and pitfalls in atherosclerotic biobanking. PMID:22294969

  7. Accelerating Correlated Quantum Chemistry Calculations Using Graphical Processing Units and a Mixed Precision Matrix Multiplication Library.

    PubMed

    Olivares-Amaya, Roberto; Watson, Mark A; Edgar, Richard G; Vogt, Leslie; Shao, Yihan; Aspuru-Guzik, Alán

    2010-01-12

    Two new tools for the acceleration of computational chemistry codes using graphical processing units (GPUs) are presented. First, we propose a general black-box approach for the efficient GPU acceleration of matrix-matrix multiplications where the matrix size is too large for the whole computation to be held in the GPU's onboard memory. Second, we show how to improve the accuracy of matrix multiplications when using only single-precision GPU devices by proposing a heterogeneous computing model, whereby single- and double-precision operations are evaluated in a mixed fashion on the GPU and central processing unit, respectively. The utility of the library is illustrated for quantum chemistry with application to the acceleration of resolution-of-the-identity second-order Møller-Plesset perturbation theory calculations for molecules, which we were previously unable to treat. In particular, for the 168-atom valinomycin molecule in a cc-pVDZ basis set, we observed speedups of 13.8, 7.8, and 10.1 times for single-, double- and mixed-precision general matrix multiply (SGEMM, DGEMM, and MGEMM), respectively. The corresponding errors in the correlation energy were reduced from -10.0 to -1.2 kcal mol(-1) for SGEMM and MGEMM, respectively, while higher accuracy can be easily achieved with a different choice of cutoff parameter.

  8. In-situ plasma processing to increase the accelerating gradients of SRF cavities

    DOE PAGES

    Doleans, Marc; Afanador, Ralph; Barnhart, Debra L.; Degraff, Brian D.; Gold, Steven W.; Hannah, Brian S.; Howell, Matthew P.; Kim, Sang-Ho; Mammosser, John; McMahan, Christopher J.; et al

    2015-12-31

    A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipactingmore » issues. This article discusses the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus.« less

  9. In-situ plasma processing to increase the accelerating gradients of superconducting radio-frequency cavities

    NASA Astrophysics Data System (ADS)

    Doleans, M.; Tyagi, P. V.; Afanador, R.; McMahan, C. J.; Ball, J. A.; Barnhart, D. L.; Blokland, W.; Crofford, M. T.; Degraff, B. D.; Gold, S. W.; Hannah, B. S.; Howell, M. P.; Kim, S.-H.; Lee, S.-W.; Mammosser, J.; Neustadt, T. S.; Saunders, J. W.; Stewart, S.; Strong, W. H.; Vandygriff, D. J.; Vandygriff, D. M.

    2016-03-01

    A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipacting issues. In this article, the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus are discussed.

  10. In-situ plasma processing to increase the accelerating gradients of SRF cavities

    SciTech Connect

    Doleans, Marc; Afanador, Ralph; Barnhart, Debra L.; Degraff, Brian D.; Gold, Steven W.; Hannah, Brian S.; Howell, Matthew P.; Kim, Sang-Ho; Mammosser, John; McMahan, Christopher J.; Neustadt, Thomas S.; Saunders, Jeffrey W.; Tyagi, Puneet V.; Vandygriff, Daniel J.; Vandygriff, David M.; Ball, Jeffrey Allen; Blokland, Willem; Crofford, Mark T.; Lee, Sung-Woo; Stewart, Stephen; Strong, William Herb

    2015-12-31

    A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipacting issues. This article discusses the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus.

  11. 12- and 15-lipoxygenases in human carotid atherosclerotic lesions: Associations with cerebrovascular symptoms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lipoxygenase (ALOX) enzymes are implicated in both pro- and anti-atherogenic processes. The aim of this study was to investigate mRNA expression of 12- and 15-lipoxygenases (ALOX12, ALOX12B, ALOX15, ALOX15B) and the atypical ALOXE3 in human carotid atherosclerotic lesions, in relation to cerebrovasc...

  12. Plasma Processing of SRF Cavities for the next Generation Of Particle Accelerators

    SciTech Connect

    Vuskovic, Leposava

    2015-11-23

    The cost-effective production of high frequency accelerating fields are the foundation for the next generation of particle accelerators. The Ar/Cl2 plasma etching technology holds the promise to yield a major reduction in cavity preparation costs. Plasma-based dry niobium surface treatment provides an excellent opportunity to remove bulk niobium, eliminate surface imperfections, increase cavity quality factor, and bring accelerating fields to higher levels. At the same time, the developed technology will be more environmentally friendly than the hydrogen fluoride-based wet etching technology. Plasma etching of inner surfaces of standard multi-cell SRF cavities is the main goal of this research in order to eliminate contaminants, including niobium oxides, in the penetration depth region. Successful plasma processing of multi-cell cavities will establish this method as a viable technique in the quest for more efficient components of next generation particle accelerators. In this project the single-cell pill box cavity plasma etching system is developed and etching conditions are determined. An actual single cell SRF cavity (1497 MHz) is plasma etched based on the pill box cavity results. The first RF test of this plasma etched cavity at cryogenic temperature is obtained. The system can also be used for other surface modifications, including tailoring niobium surface properties, surface passivation or nitriding for better performance of SRF cavities. The results of this plasma processing technology may be applied to most of the current SRF cavity fabrication projects. In the course of this project it has been demonstrated that a capacitively coupled radio-frequency discharge can be successfully used for etching curved niobium surfaces, in particular the inner walls of SRF cavities. The results could also be applicable to the inner or concave surfaces of any 3D structure other than an SRF cavity.

  13. ACCELERATED PROCESSING OF SB4 AND PREPARATION FOR SB5 PROCESSING AT DWPF

    SciTech Connect

    Herman, C

    2008-12-01

    The Defense Waste Processing Facility (DWPF) initiated processing of Sludge Batch 4 (SB4) in May 2007. SB4 was the first DWPF sludge batch to contain significant quantities of HM or high Al sludge. Initial testing with SB4 simulants showed potential negative impacts to DWPF processing; therefore, Savannah River National Laboratory (SRNL) performed extensive testing in an attempt to optimize processing. SRNL's testing has resulted in the highest DWPF production rates since start-up. During SB4 processing, DWPF also began incorporating waste streams from the interim salt processing facilities to initiate coupled operations. While DWPF has been processing SB4, the Liquid Waste Organization (LWO) and the SRNL have been preparing Sludge Batch 5 (SB5). SB5 has undergone low-temperature aluminum dissolution to reduce the mass of sludge for vitrification and will contain a small fraction of Purex sludge. A high-level review of SB4 processing and the SB5 preparation studies will be provided.

  14. Effects of accelerated reading rate on syntactic processing of Hebrew sentences: electrophysiological evidence.

    PubMed

    Leikin, M; Breznitz, Z

    2001-05-01

    The present study was designed to investigate whether accelerated reading rate influences the way adult readers process sentence components with different grammatical functions. Participants were 20 male native Hebrew-speaking college students aged 18-27 years. The processing of normal word strings was examined during word-by-word reading of sentences having subject-verb-object (SVO) syntactic structure in self-paced and fast-paced conditions. In both reading conditions, the N100 (late positive) and P300 (late negative) event-related potential (ERP) components were sensitive to such internal processes as recognition of words' syntactic functions. However, an accelerated reading rate influenced the way in which readers processed these sentence elements. In the self-paced condition, the predicate-centered (morphologically based) strategy was used, whereas in the fast-paced condition an approach that was more like the word-order strategy was used. This new pattern was correlated with findings on the shortening of latency and the increasing of amplitudes in both N100 and P300 ERP components for most sentence elements. These changes seemed to be related to improved working memory functioning and maximized attention.

  15. Quantitative evaluation of lipid concentration in atherosclerotic plaque phantom by near-infrared multispectral angioscope at wavelengths around 1200 nm

    NASA Astrophysics Data System (ADS)

    Matsui, Daichi; Ishii, Katsunori; Awazu, Kunio

    2015-07-01

    Atherosclerosis is a primary cause of critical ischemic diseases like heart infarction or stroke. A method that can provide detailed information about the stability of atherosclerotic plaques is required. We focused on spectroscopic techniques that could evaluate the chemical composition of lipid in plaques. A novel angioscope using multispectral imaging at wavelengths around 1200 nm for quantitative evaluation of atherosclerotic plaques was developed. The angioscope consists of a halogen lamp, an indium gallium arsenide (InGaAs) camera, 3 optical band pass filters transmitting wavelengths of 1150, 1200, and 1300 nm, an image fiber having 0.7 mm outer diameter, and an irradiation fiber which consists of 7 multimode fibers. Atherosclerotic plaque phantoms with 100, 60, 20 vol.% of lipid were prepared and measured by the multispectral angioscope. The acquired datasets were processed by spectral angle mapper (SAM) method. As a result, simulated plaque areas in atherosclerotic plaque phantoms that could not be detected by an angioscopic visible image could be clearly enhanced. In addition, quantitative evaluation of atherosclerotic plaque phantoms based on the lipid volume fractions was performed up to 20 vol.%. These results show the potential of a multispectral angioscope at wavelengths around 1200 nm for quantitative evaluation of the stability of atherosclerotic plaques.

  16. Open-source graphics processing unit-accelerated ray tracer for optical simulation

    NASA Astrophysics Data System (ADS)

    Mauch, Florian; Gronle, Marc; Lyda, Wolfram; Osten, Wolfgang

    2013-05-01

    Ray tracing still is the workhorse in optical design and simulation. Its basic principle, propagating light as a set of mutually independent rays, implies a linear dependency of the computational effort and the number of rays involved in the problem. At the same time, the mutual independence of the light rays bears a huge potential for parallelization of the computational load. This potential has recently been recognized in the visualization community, where graphics processing unit (GPU)-accelerated ray tracing is used to render photorealistic images. However, precision requirements in optical simulation are substantially higher than in visualization, and therefore performance results known from visualization cannot be expected to transfer to optical simulation one-to-one. In this contribution, we present an open-source implementation of a GPU-accelerated ray tracer, based on nVidias acceleration engine OptiX, that traces in double precision and exploits the massively parallel architecture of modern graphics cards. We compare its performance to a CPU-based tracer that has been developed in parallel.

  17. Monitoring oil displacement processes with k-t accelerated spin echo SPI.

    PubMed

    Li, Ming; Xiao, Dan; Romero-Zerón, Laura; Balcom, Bruce J

    2016-03-01

    Magnetic resonance imaging (MRI) is a robust tool to monitor oil displacement processes in porous media. Conventional MRI measurement times can be lengthy, which hinders monitoring time-dependent displacements. Knowledge of the oil and water microscopic distribution is important because their pore scale behavior reflects the oil trapping mechanisms. The oil and water pore scale distribution is reflected in the magnetic resonance T2 signal lifetime distribution. In this work, a pure phase-encoding MRI technique, spin echo SPI (SE-SPI), was employed to monitor oil displacement during water flooding and polymer flooding. A k-t acceleration method, with low-rank matrix completion, was employed to improve the temporal resolution of the SE-SPI MRI measurements. Comparison to conventional SE-SPI T2 mapping measurements revealed that the k-t accelerated measurement was more sensitive and provided higher-quality results. It was demonstrated that the k-t acceleration decreased the average measurement time from 66.7 to 20.3 min in this work. A perfluorinated oil, containing no (1) H, and H2 O brine were employed to distinguish oil and water phases in model flooding experiments. High-quality 1D water saturation profiles were acquired from the k-t accelerated SE-SPI measurements. Spatially and temporally resolved T2 distributions were extracted from the profile data. The shift in the (1) H T2 distribution of water in the pore space to longer lifetimes during water flooding and polymer flooding is consistent with increased water content in the pore space. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Monitoring oil displacement processes with k-t accelerated spin echo SPI.

    PubMed

    Li, Ming; Xiao, Dan; Romero-Zerón, Laura; Balcom, Bruce J

    2016-03-01

    Magnetic resonance imaging (MRI) is a robust tool to monitor oil displacement processes in porous media. Conventional MRI measurement times can be lengthy, which hinders monitoring time-dependent displacements. Knowledge of the oil and water microscopic distribution is important because their pore scale behavior reflects the oil trapping mechanisms. The oil and water pore scale distribution is reflected in the magnetic resonance T2 signal lifetime distribution. In this work, a pure phase-encoding MRI technique, spin echo SPI (SE-SPI), was employed to monitor oil displacement during water flooding and polymer flooding. A k-t acceleration method, with low-rank matrix completion, was employed to improve the temporal resolution of the SE-SPI MRI measurements. Comparison to conventional SE-SPI T2 mapping measurements revealed that the k-t accelerated measurement was more sensitive and provided higher-quality results. It was demonstrated that the k-t acceleration decreased the average measurement time from 66.7 to 20.3 min in this work. A perfluorinated oil, containing no (1) H, and H2 O brine were employed to distinguish oil and water phases in model flooding experiments. High-quality 1D water saturation profiles were acquired from the k-t accelerated SE-SPI measurements. Spatially and temporally resolved T2 distributions were extracted from the profile data. The shift in the (1) H T2 distribution of water in the pore space to longer lifetimes during water flooding and polymer flooding is consistent with increased water content in the pore space. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26626141

  19. Physical processes at work in sub-30 fs, PW laser pulse-driven plasma accelerators: Towards GeV electron acceleration experiments at CILEX facility

    NASA Astrophysics Data System (ADS)

    Beck, A.; Kalmykov, S. Y.; Davoine, X.; Lifschitz, A.; Shadwick, B. A.; Malka, V.; Specka, A.

    2014-03-01

    Optimal regimes and physical processes at work are identified for the first round of laser wakefield acceleration experiments proposed at a future CILEX facility. The Apollon-10P CILEX laser, delivering fully compressed, near-PW-power pulses of sub-25 fs duration, is well suited for driving electron density wakes in the blowout regime in cm-length gas targets. Early destruction of the pulse (partly due to energy depletion) prevents electrons from reaching dephasing, limiting the energy gain to about 3 GeV. However, the optimal operating regimes, found with reduced and full three-dimensional particle-in-cell simulations, show high energy efficiency, with about 10% of incident pulse energy transferred to 3 GeV electron bunches with sub-5% energy spread, half-nC charge, and absolutely no low-energy background. This optimal acceleration occurs in 2 cm length plasmas of electron density below 1018 cm-3. Due to their high charge and low phase space volume, these multi-GeV bunches are tailor-made for staged acceleration planned in the framework of the CILEX project. The hallmarks of the optimal regime are electron self-injection at the early stage of laser pulse propagation, stable self-guiding of the pulse through the entire acceleration process, and no need for an external plasma channel. With the initial focal spot closely matched for the nonlinear self-guiding, the laser pulse stabilizes transversely within two Rayleigh lengths, preventing subsequent evolution of the accelerating bucket. This dynamics prevents continuous self-injection of background electrons, preserving low phase space volume of the bunch through the plasma. Near the end of propagation, an optical shock builds up in the pulse tail. This neither disrupts pulse propagation nor produces any noticeable low-energy background in the electron spectra, which is in striking contrast with most of existing GeV-scale acceleration experiments.

  20. Ground Test of the Urine Processing Assembly for Accelerations and Transfer Functions

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Almond, Deborah F. (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview of the ground test of the urine processing assembly for accelerations and transfer functions. Details are given on the test setup, test data, data analysis, analytical results, and microgravity assessment. The conclusions of the tests include the following: (1) the single input/multiple output method is useful if the data is acquired by tri-axial accelerometers and inputs can be considered uncorrelated; (2) tying coherence with the matrix yields higher confidence in results; (3) the WRS#2 rack ORUs need to be isolated; (4) and future work includes a plan for characterizing performance of isolation materials.

  1. Study of the near-electrode processes in quasi-steady plasma accelerators with impenetrable electrodes

    SciTech Connect

    Kozlov, A. N.

    2012-01-15

    Near-electrode processes in a coaxial plasma accelerator with equipotential impenetrable electrodes are simulated using a two-dimensional (generally, time-dependent) two-fluid MHD model with allowance for the Hall effect and the plasma conductivity tensor. The simulations confirm the theoretically predicted mechanism of the so-called 'crisis of current' caused by the Hall effect. The simulation results are compared with available experimental data. The influence of both the method of plasma supply to the channel and an additional longitudinal magnetic field on the development of near-electrode instabilities preceding the crisis of current is studied.

  2. A practical protocol to accelerate the breeding process of rice in semitropical and tropical regions

    PubMed Central

    Li, Jun; Hou, Xianhui; Liu, Jindi; Qian, Changgen; Gao, Rongcun; Li, Linchuan; Li, Jinjun

    2015-01-01

    Breeding of excellent rice varieties is essential for modern rice production. Typical breeding procedures to introduce and maintain valuable agricultural traits require at least 8 generations from crossing to stabilization, always taking more than 4–5 years of work. This long and tedious process is the rate-limiting step in the development of new varieties, and therefore fast culturing methods are in urgent need. Taking advantage of early flowering characteristics of light-sensitive rice under short-day conditions, we have developed a practical protocol to accelerate the breeding cycle of rice, which we have termed the “1 + 2”, “2 + 2”, “1 + 3”, and “0 + 5” methods according to the different rice varieties and different breeding purposes. We have also incorporated several techniques, including glume cutting, seed desiccation at 50°C in a drier seed dormancy breakage with low concentration of HNO3, and direct seeding. Using the above strategy, we have shortened the life cycle of light-sensitive rice varieties to about 70 days, making it possible for several rice cultivars to proliferate 4–5 generations in a single calendar year. This protocol greatly accelerates the process of new variety breeding, and can be used in rice research for shortening the process of genetic analysis and the construction of mapping populations. PMID:26175620

  3. Accelerated simulation of stochastic particle removal processes in particle-resolved aerosol models

    NASA Astrophysics Data System (ADS)

    Curtis, J. H.; Michelotti, M. D.; Riemer, N.; Heath, M. T.; West, M.

    2016-10-01

    Stochastic particle-resolved methods have proven useful for simulating multi-dimensional systems such as composition-resolved aerosol size distributions. While particle-resolved methods have substantial benefits for highly detailed simulations, these techniques suffer from high computational cost, motivating efforts to improve their algorithmic efficiency. Here we formulate an algorithm for accelerating particle removal processes by aggregating particles of similar size into bins. We present the Binned Algorithm for particle removal processes and analyze its performance with application to the atmospherically relevant process of aerosol dry deposition. We show that the Binned Algorithm can dramatically improve the efficiency of particle removals, particularly for low removal rates, and that computational cost is reduced without introducing additional error. In simulations of aerosol particle removal by dry deposition in atmospherically relevant conditions, we demonstrate about 50-times increase in algorithm efficiency.

  4. Stochastic Modeling and Analysis of Multiple Nonlinear Accelerated Degradation Processes through Information Fusion.

    PubMed

    Sun, Fuqiang; Liu, Le; Li, Xiaoyang; Liao, Haitao

    2016-01-01

    Accelerated degradation testing (ADT) is an efficient technique for evaluating the lifetime of a highly reliable product whose underlying failure process may be traced by the degradation of the product's performance parameters with time. However, most research on ADT mainly focuses on a single performance parameter. In reality, the performance of a modern product is usually characterized by multiple parameters, and the degradation paths are usually nonlinear. To address such problems, this paper develops a new s-dependent nonlinear ADT model for products with multiple performance parameters using a general Wiener process and copulas. The general Wiener process models the nonlinear ADT data, and the dependency among different degradation measures is analyzed using the copula method. An engineering case study on a tuner's ADT data is conducted to demonstrate the effectiveness of the proposed method. The results illustrate that the proposed method is quite effective in estimating the lifetime of a product with s-dependent performance parameters. PMID:27509499

  5. Large scale neural circuit mapping data analysis accelerated with the graphical processing unit (GPU)

    PubMed Central

    Shi, Yulin; Veidenbaum, Alexander V.; Nicolau, Alex; Xu, Xiangmin

    2014-01-01

    Background Modern neuroscience research demands computing power. Neural circuit mapping studies such as those using laser scanning photostimulation (LSPS) produce large amounts of data and require intensive computation for post-hoc processing and analysis. New Method Here we report on the design and implementation of a cost-effective desktop computer system for accelerated experimental data processing with recent GPU computing technology. A new version of Matlab software with GPU enabled functions is used to develop programs that run on Nvidia GPUs to harness their parallel computing power. Results We evaluated both the central processing unit (CPU) and GPU-enabled computational performance of our system in benchmark testing and practical applications. The experimental results show that the GPU-CPU co-processing of simulated data and actual LSPS experimental data clearly outperformed the multi-core CPU with up to a 22x speedup, depending on computational tasks. Further, we present a comparison of numerical accuracy between GPU and CPU computation to verify the precision of GPU computation. In addition, we show how GPUs can be effectively adapted to improve the performance of commercial image processing software such as Adobe Photoshop. Comparison with Existing Method(s) To our best knowledge, this is the first demonstration of GPU application in neural circuit mapping and electrophysiology-based data processing. Conclusions Together, GPU enabled computation enhances our ability to process large-scale data sets derived from neural circuit mapping studies, allowing for increased processing speeds while retaining data precision. PMID:25277633

  6. miRNAs in atherosclerotic plaque initiation, progression, and rupture

    PubMed Central

    Andreou, Ioannis; Sun, Xinghui; Stone, Peter H.; Edelman, Elazer R.; Feinberg, Mark W.

    2015-01-01

    Atherosclerosis is a chronic immune-inflammatory disorder that integrates multiple cell types and a diverse set of inflammatory mediators. miRNAs are emerging as important post-transcriptional regulators of gene expression in most, if not all, vertebrate cells and constitute central players in many physiological and pathological processes. Rapidly accumulating experimental studies reveal their key role in cellular and molecular processes related to the development of atherosclerosis. Here, we review the current evidence for the involvement of miRNAs in early atherosclerotic lesion formation to plaque rupture and erosion. We conclude with a perspective on the clinical relevance, therapeutic opportunities, and future challenges of miRNA biology in the pathogenesis of this complex disease. PMID:25771097

  7. Spatiotemporal processing of linear acceleration: primary afferent and central vestibular neuron responses

    NASA Technical Reports Server (NTRS)

    Angelaki, D. E.; Dickman, J. D.

    2000-01-01

    Spatiotemporal convergence and two-dimensional (2-D) neural tuning have been proposed as a major neural mechanism in the signal processing of linear acceleration. To examine this hypothesis, we studied the firing properties of primary otolith afferents and central otolith neurons that respond exclusively to horizontal linear accelerations of the head (0.16-10 Hz) in alert rhesus monkeys. Unlike primary afferents, the majority of central otolith neurons exhibited 2-D spatial tuning to linear acceleration. As a result, central otolith dynamics vary as a function of movement direction. During movement along the maximum sensitivity direction, the dynamics of all central otolith neurons differed significantly from those observed for the primary afferent population. Specifically at low frequencies (acceleration. At least three different groups of central response dynamics were described according to the properties observed for motion along the maximum sensitivity direction. "High-pass" neurons exhibited increasing gains and phase values as a function of frequency. "Flat" neurons were characterized by relatively flat gains and constant phase lags (approximately 20-55 degrees ). A few neurons ("low-pass") were characterized by decreasing gain and phase as a function of frequency. The response dynamics of central otolith neurons suggest that the approximately 90 degrees phase lags observed at low frequencies are not the result of a neural integration but rather the effect of nonminimum phase behavior, which could arise at least partly through spatiotemporal convergence. Neither afferent nor central otolith neurons discriminated between gravitational and inertial components of linear acceleration. Thus response sensitivity was indistinguishable during 0.5-Hz pitch oscillations and fore-aft movements

  8. UV Irradiation Accelerates Amyloid Precursor Protein (APP) Processing and Disrupts APP Axonal Transport

    PubMed Central

    Almenar-Queralt, Angels; Falzone, Tomas L.; Shen, Zhouxin; Lillo, Concepcion; Killian, Rhiannon L.; Arreola, Angela S.; Niederst, Emily D.; Ng, Kheng S.; Kim, Sonia N.; Briggs, Steven P.; Williams, David S.

    2014-01-01

    Overexpression and/or abnormal cleavage of amyloid precursor protein (APP) are linked to Alzheimer's disease (AD) development and progression. However, the molecular mechanisms regulating cellular levels of APP or its processing, and the physiological and pathological consequences of altered processing are not well understood. Here, using mouse and human cells, we found that neuronal damage induced by UV irradiation leads to specific APP, APLP1, and APLP2 decline by accelerating their secretase-dependent processing. Pharmacological inhibition of endosomal/lysosomal activity partially protects UV-induced APP processing implying contribution of the endosomal and/or lysosomal compartments in this process. We found that a biological consequence of UV-induced γ-secretase processing of APP is impairment of APP axonal transport. To probe the functional consequences of impaired APP axonal transport, we isolated and analyzed presumptive APP-containing axonal transport vesicles from mouse cortical synaptosomes using electron microscopy, biochemical, and mass spectrometry analyses. We identified a population of morphologically heterogeneous organelles that contains APP, the secretase machinery, molecular motors, and previously proposed and new residents of APP vesicles. These possible cargoes are enriched in proteins whose dysfunction could contribute to neuronal malfunction and diseases of the nervous system including AD. Together, these results suggest that damage-induced APP processing might impair APP axonal transport, which could result in failure of synaptic maintenance and neuronal dysfunction. PMID:24573290

  9. Accelerated rescaling of single Monte Carlo simulation runs with the Graphics Processing Unit (GPU).

    PubMed

    Yang, Owen; Choi, Bernard

    2013-01-01

    To interpret fiber-based and camera-based measurements of remitted light from biological tissues, researchers typically use analytical models, such as the diffusion approximation to light transport theory, or stochastic models, such as Monte Carlo modeling. To achieve rapid (ideally real-time) measurement of tissue optical properties, especially in clinical situations, there is a critical need to accelerate Monte Carlo simulation runs. In this manuscript, we report on our approach using the Graphics Processing Unit (GPU) to accelerate rescaling of single Monte Carlo runs to calculate rapidly diffuse reflectance values for different sets of tissue optical properties. We selected MATLAB to enable non-specialists in C and CUDA-based programming to use the generated open-source code. We developed a software package with four abstraction layers. To calculate a set of diffuse reflectance values from a simulated tissue with homogeneous optical properties, our rescaling GPU-based approach achieves a reduction in computation time of several orders of magnitude as compared to other GPU-based approaches. Specifically, our GPU-based approach generated a diffuse reflectance value in 0.08ms. The transfer time from CPU to GPU memory currently is a limiting factor with GPU-based calculations. However, for calculation of multiple diffuse reflectance values, our GPU-based approach still can lead to processing that is ~3400 times faster than other GPU-based approaches. PMID:24298424

  10. Atherosclerotic renal artery stenosis: Current status

    PubMed Central

    Kwon, Soon Hyo; Lerman, Lilach O.

    2014-01-01

    Atherosclerotic renal artery stenosis (ARAS) remains a major cause of secondary hypertension and renal failure. Randomized, prospective trials show that medical treatment should constitute the main therapeutic approach in ARAS. Regardless of intensive treatment and adequate blood pressure control, however, renal and extra-renal complications are not uncommon. Yet, the precise mechanisms, accurate detection, and optimal treatment in ARAS remain elusive. Strategies oriented to early detection and targeting these pathogenic pathways might prevent development of clinical endpoints. Here, we review the results of recent clinical trials, current understanding of the pathogenic mechanisms, novel imaging techniques to assess renal damage in ARAS, and treatment options. PMID:25908472

  11. Anti-atherosclerotic therapy based on botanicals.

    PubMed

    Orekhov, Alexander N; Sobenin, Igor A; Korneev, Nikolay V; Kirichenko, Tatyana V; Myasoedova, Veronika A; Melnichenko, Alexandra A; Balcells, Mercedes; Edelman, Elazer R; Bobryshev, Yuri V

    2013-04-01

    Natural products including botanicals for both therapy of clinical manifestations of atherosclerosis and reduction of atherosclerosis risk factors are topics of recent patents. Only a few recent patents are relevant to the direct antiatherosclerotic therapy leading to regression of atherosclerotic lesions. Earlier, using a cellular model we have developed and patented several anti-atherosclerotic drugs. The AMAR (Atherosclerosis Monitoring and Atherogenicity Reduction) study was designed to estimate the effect of two-year treatment with time-released garlic-based drug Allicor on the progression of carotid atherosclerosis in 196 asymptomatic men aged 40-74 in double-blinded placebo-controlled randomized clinical study. The primary outcome was the rate of atherosclerosis progression, measured by high-resolution B-mode ultrasonography as the increase in carotid intima-media thickness (IMT) of the far wall of common carotid arteries. The mean rate of IMT changes in Allicor-treated group (-0.022±0.007 mm per year) was significantly different (P = 0.002) from the placebo group in which there was a moderate progression of 0.015±0.008 mm at the overall mean baseline IMT of 0.931±0.009 mm. A significant correlation was found between the changes in blood serum atherogenicity (the ability of serum to induce cholesterol accumulation in cultured cells) during the study and the changes in intima-media thickness of common carotid arteries (r = 0.144, P = 0.045). Thus, the results of AMAR study demonstrate that long-term treatment with Allicor has a direct anti-atherosclerotic effect on carotid atherosclerosis and this effect is likely to be due to serum atherogenicity inhibition. The beneficial effects of other botanicals including Inflaminat (calendula, elder and violet), phytoestrogen- rich Karinat (garlic powder, extract of grape seeds, green tea leafs, hop cones, β-carotene, α-tocopherol and ascorbic acid) on atherosclerosis have also been revealed in clinical studies

  12. Atherosclerotic renal artery stenosis: current status.

    PubMed

    Kwon, Soon Hyo; Lerman, Lilach O

    2015-05-01

    Atherosclerotic renal artery stenosis (ARAS) remains a major cause of secondary hypertension and kidney failure. Randomized prospective trials show that medical treatment should constitute the main therapeutic approach in ARAS. Regardless of intensive treatment and adequate blood pressure control, however, renal and extrarenal complications are not uncommon. Yet, the precise mechanisms, accurate detection, and optimal treatment in ARAS remain elusive. Strategies oriented to early detection and targeting these pathogenic pathways might prevent development of clinical end points. Here, we review the results of recent clinical trials, current understanding of the pathogenic mechanisms, novel imaging techniques to assess kidney damage in ARAS, and treatment options. PMID:25908472

  13. Zinc Restored the Decreased Vascular Smooth Muscle Cell Viability under Atherosclerotic Calcification Conditions

    PubMed Central

    Shin, Mee-Young; Kwun, In-Sook

    2014-01-01

    Zinc is considered to be involved in maintaining healthy vascular condition. Atherosclerotic calcification of vascular smooth muscle cells (VSMCs) occurs via the mechanism of cell death; therefore, cell viability is a critical factor for preventing VSMC calcification. In this study, we tested whether zinc affected VSMC viability under both normal physiological non-calcifying (0 mM P) and atherosclerotic calcifying conditions (3 and 5 mM P), since VSMC physiological characters change during the VSMC calcification process. The study results showed that an optimal zinc level (15 μM) restored the decreased VSMC viability which was induced under low zinc levels (0 and 1 μM) and calcifying conditions (3 and 5 mM P) at 9 and 15 days culture. This zinc-protecting effect for VSMC viability is more prominent under atherosclerotic calcifying condition (3 and 5 mM P) than normal condition (0 mM P). Also, the increased VSMC viability was consistent with the decreased Ca and P accumulation in VSMC cell layers. The results suggested that zinc could be an effective biomineral for preventing VSMC calcification under atherosclerotic calcifying conditions. PMID:25580404

  14. Citrullination within the atherosclerotic plaque: A potential target for the anti-citrullinated protein antibody response in rheumatoid arthritis

    PubMed Central

    Sokolove, Jeremy; Sharpe, Orr; Brennan, Matthew; Lahey, Lauren J.; Kao, Amy H.; Krishnan, Eswar; Edmundowicz, Daniel; Lepus, Christin M.; Wasko, Mary Chester; Robinson, William H.

    2013-01-01

    Background/Purpose Patients with rheumatoid arthritis (RA) are at increased risk for cardiovascular disease, an observation not explained by traditional cardiac risk factors and generally limited to those with RA-associated autoantibodies such as rheumatoid factor and anti-citrullinated protein antibodies (ACPA). We hypothesized that citrullinated proteins within the atherosclerotic plaque can be targeted by ACPA, forming stimulatory immune complexes which propagate the progression of atherosclerosis. Methods and Results Protein lysates prepared from atherosclerotic segments of human aorta were investigated for the presence of citrulline-modified proteins and specifically citrullinated fibrinogen (cFb) by immunoprecipitation and/or immunoblotting followed by mass spectrometry. Immunohistochemistry was performed in coronary artery plaques for the presence of citrullinated proteins and the PAD4 enzyme. Levels of anti-cyclic citrullinated peptide (CCP), anti-citrullinated vimentin (cVim), and anti-cFb antibodies were measured in 134 women with seropositive RA previously characterized for the presence of subclinical atherosclerosis by electron beam CT scan (EBCT). Western analysis of atherosclerotic plaque lysates demonstrated several citrullinated proteins and the presence of cFb was confirmed by immunoprecipitation, and mass spectroscopy. Immunohistochemistry demonstrated co-localization of citrullinated proteins and the PAD4 enzyme within the coronary artery plaque. In age-adjusted regression models, antibodies targeting cFb and cit-vimentin, but not CCP2, were associated with an increased aortic plaque burden. Conclusion Citrullinated proteins are prevalent within the atherosclerotic plaque, and certain ACPAs are associated with atherosclerotic burden. These observations suggest that targeting of citrullinated epitopes, specifically cFb, within the atherosclerotic plaque could provide a mechanism for accelerated atherosclerosis observed in patients with RA. PMID

  15. Surface damage correction, and atomic level smoothing of optics by Accelerated Neutral Atom Beam (ANAB) Processing

    NASA Astrophysics Data System (ADS)

    Walsh, M.; Chau, K.; Kirkpatrick, S.; Svrluga, R.

    2014-10-01

    Surface damage and surface contamination of optics has long been a source of problems for laser, lithography and other industries. Nano-sized surface defects may present significant performance issues in optical materials for deep UV and EUV applications. The effects of nanometer sized surface damage (scratches, pits, and organics) on the surface of optics made of traditional materials and new more exotic materials is a limiting factor to high end performance. Angstrom level smoothing of materials such as calcium fluoride, spinel, zinc sulfide, BK7 and others presents a unique set of challenges. Exogenesis Corporation, using its proprietary Accelerated Neutral Atom Beam (ANAB) technology, is able to remove nano-scale surface damage and contamination and leaves many material surfaces with roughness typically around one angstrom. This process technology has been demonstrated on nonlinear crystals, and various other high-end optical materials. This paper describes the ANAB technology and summarizes smoothing results for various materials that have been processed with ANAB. All surface measurement data for the paper was produced via AFM analysis. Exogenesis Corporation's ANAB processing technology is a new and unique surface modification technique that has demonstrated to be highly effective at correcting nano-scale surface defects. ANAB is a non-contact vacuum process comprised of an intense beam of accelerated, electrically neutral gas atoms with average energies of a few tens of electron volts. The ANAB process does not apply normal forces associated with traditional polishing techniques. ANAB efficiently removes surface contaminants, nano-scale scratches, bumps and other asperities under low energy physical sputtering conditions as the removal action proceeds. ANAB may be used to remove a precisely controlled, uniform thickness of material without any increase of surface roughness, regardless of the total amount of material removed. The ANAB process does not

  16. Accelerated Molecular Dynamics Simulations with the AMOEBA Polarizable Force Field on Graphics Processing Units.

    PubMed

    Lindert, Steffen; Bucher, Denis; Eastman, Peter; Pande, Vijay; McCammon, J Andrew

    2013-11-12

    The accelerated molecular dynamics (aMD) method has recently been shown to enhance the sampling of biomolecules in molecular dynamics (MD) simulations, often by several orders of magnitude. Here, we describe an implementation of the aMD method for the OpenMM application layer that takes full advantage of graphics processing units (GPUs) computing. The aMD method is shown to work in combination with the AMOEBA polarizable force field (AMOEBA-aMD), allowing the simulation of long time-scale events with a polarizable force field. Benchmarks are provided to show that the AMOEBA-aMD method is efficiently implemented and produces accurate results in its standard parametrization. For the BPTI protein, we demonstrate that the protein structure described with AMOEBA remains stable even on the extended time scales accessed at high levels of accelerations. For the DNA repair metalloenzyme endonuclease IV, we show that the use of the AMOEBA force field is a significant improvement over fixed charged models for describing the enzyme active-site. The new AMOEBA-aMD method is publicly available (http://wiki.simtk.org/openmm/VirtualRepository) and promises to be interesting for studying complex systems that can benefit from both the use of a polarizable force field and enhanced sampling.

  17. Accelerating image reconstruction in three-dimensional optoacoustic tomography on graphics processing units

    PubMed Central

    Wang, Kun; Huang, Chao; Kao, Yu-Jiun; Chou, Cheng-Ying; Oraevsky, Alexander A.; Anastasio, Mark A.

    2013-01-01

    Purpose: Optoacoustic tomography (OAT) is inherently a three-dimensional (3D) inverse problem. However, most studies of OAT image reconstruction still employ two-dimensional imaging models. One important reason is because 3D image reconstruction is computationally burdensome. The aim of this work is to accelerate existing image reconstruction algorithms for 3D OAT by use of parallel programming techniques. Methods: Parallelization strategies are proposed to accelerate a filtered backprojection (FBP) algorithm and two different pairs of projection/backprojection operations that correspond to two different numerical imaging models. The algorithms are designed to fully exploit the parallel computing power of graphics processing units (GPUs). In order to evaluate the parallelization strategies for the projection/backprojection pairs, an iterative image reconstruction algorithm is implemented. Computer simulation and experimental studies are conducted to investigate the computational efficiency and numerical accuracy of the developed algorithms. Results: The GPU implementations improve the computational efficiency by factors of 1000, 125, and 250 for the FBP algorithm and the two pairs of projection/backprojection operators, respectively. Accurate images are reconstructed by use of the FBP and iterative image reconstruction algorithms from both computer-simulated and experimental data. Conclusions: Parallelization strategies for 3D OAT image reconstruction are proposed for the first time. These GPU-based implementations significantly reduce the computational time for 3D image reconstruction, complementing our earlier work on 3D OAT iterative image reconstruction. PMID:23387778

  18. GAMER: A GRAPHIC PROCESSING UNIT ACCELERATED ADAPTIVE-MESH-REFINEMENT CODE FOR ASTROPHYSICS

    SciTech Connect

    Schive, H.-Y.; Tsai, Y.-C.; Chiueh Tzihong

    2010-02-01

    We present the newly developed code, GPU-accelerated Adaptive-MEsh-Refinement code (GAMER), which adopts a novel approach in improving the performance of adaptive-mesh-refinement (AMR) astrophysical simulations by a large factor with the use of the graphic processing unit (GPU). The AMR implementation is based on a hierarchy of grid patches with an oct-tree data structure. We adopt a three-dimensional relaxing total variation diminishing scheme for the hydrodynamic solver and a multi-level relaxation scheme for the Poisson solver. Both solvers have been implemented in GPU, by which hundreds of patches can be advanced in parallel. The computational overhead associated with the data transfer between the CPU and GPU is carefully reduced by utilizing the capability of asynchronous memory copies in GPU, and the computing time of the ghost-zone values for each patch is diminished by overlapping it with the GPU computations. We demonstrate the accuracy of the code by performing several standard test problems in astrophysics. GAMER is a parallel code that can be run in a multi-GPU cluster system. We measure the performance of the code by performing purely baryonic cosmological simulations in different hardware implementations, in which detailed timing analyses provide comparison between the computations with and without GPU(s) acceleration. Maximum speed-up factors of 12.19 and 10.47 are demonstrated using one GPU with 4096{sup 3} effective resolution and 16 GPUs with 8192{sup 3} effective resolution, respectively.

  19. On-site installation and shielding of a mobile electron accelerator for radiation processing

    NASA Astrophysics Data System (ADS)

    Catana, Dumitru; Panaitescu, Julian; Axinescu, Silviu; Manolache, Dumitru; Matei, Constantin; Corcodel, Calin; Ulmeanu, Magdalena; Bestea, Virgil

    1995-05-01

    The development of radiation processing of some bulk products, e.g. grains or potatoes, would be sustained if the irradiation had been carried out at the place of storage, i.e. silo. A promising solution is proposed consisting of a mobile electron accelerator, installed on a couple of trucks and traveling from one customer to another. The energy of the accelerated electrons was chosen at 5 MeV, with 10 to 50 kW beam power. The irradiation is possible either with electrons or with bremsstrahlung. A major problem of the above solution is the provision of adequate shielding at the customer, with a minimum investment cost. Plans for a bunker are presented, which houses the truck carrying the radiation head. The beam is vertical downwards, through the truck floor, through a transport pipe and a scanning horn. The irradiation takes place in a pit, where the products are transported through a belt. The belt path is so chosen as to minimize openings in the shielding. Shielding calculations are presented supposing a working regime with 5 MeV bremsstrahlung. Leakage and scattered radiation are taken into account.

  20. Hyperspectral imaging of atherosclerotic plaques in vitro

    NASA Astrophysics Data System (ADS)

    Larsen, Eivind L. P.; Randeberg, Lise L.; Olstad, Elisabeth; Haugen, Olav A.; Aksnes, Astrid; Svaasand, Lars O.

    2011-02-01

    Vulnerable plaques constitute a risk for serious heart problems, and are difficult to identify using existing methods. Hyperspectral imaging combines spectral- and spatial information, providing new possibilities for precise optical characterization of atherosclerotic lesions. Hyperspectral data were collected from excised aorta samples (n = 11) using both white-light and ultraviolet illumination. Single lesions (n = 42) were chosen for further investigation, and classified according to histological findings. The corresponding hyperspectral images were characterized using statistical image analysis tools (minimum noise fraction, K-means clustering, principal component analysis) and evaluation of reflectance/fluorescence spectra. Image analysis combined with histology revealed the complexity and heterogeneity of aortic plaques. Plaque features such as lipids and calcifications could be identified from the hyperspectral images. Most of the advanced lesions had a central region surrounded by an outer rim or shoulder-region of the plaque, which is considered a weak spot in vulnerable lesions. These features could be identified in both the white-light and fluorescence data. Hyperspectral imaging was shown to be a promising tool for detection and characterization of advanced atherosclerotic plaques in vitro. Hyperspectral imaging provides more diagnostic information about the heterogeneity of the lesions than conventional single point spectroscopic measurements.

  1. High-Speed Digital Signal Processing Method for Detection of Repeating Earthquakes Using GPGPU-Acceleration

    NASA Astrophysics Data System (ADS)

    Kawakami, Taiki; Okubo, Kan; Uchida, Naoki; Takeuchi, Nobunao; Matsuzawa, Toru

    2013-04-01

    Repeating earthquakes are occurring on the similar asperity at the plate boundary. These earthquakes have an important property; the seismic waveforms observed at the identical observation site are very similar regardless of their occurrence time. The slip histories of repeating earthquakes could reveal the existence of asperities: The Analysis of repeating earthquakes can detect the characteristics of the asperities and realize the temporal and spatial monitoring of the slip in the plate boundary. Moreover, we are expecting the medium-term predictions of earthquake at the plate boundary by means of analysis of repeating earthquakes. Although the previous works mostly clarified the existence of asperity and repeating earthquake, and relationship between asperity and quasi-static slip area, the stable and robust method for automatic detection of repeating earthquakes has not been established yet. Furthermore, in order to process the enormous data (so-called big data) the speedup of the signal processing is an important issue. Recently, GPU (Graphic Processing Unit) is used as an acceleration tool for the signal processing in various study fields. This movement is called GPGPU (General Purpose computing on GPUs). In the last few years the performance of GPU keeps on improving rapidly. That is, a PC (personal computer) with GPUs might be a personal supercomputer. GPU computing gives us the high-performance computing environment at a lower cost than before. Therefore, the use of GPUs contributes to a significant reduction of the execution time in signal processing of the huge seismic data. In this study, first, we applied the band-limited Fourier phase correlation as a fast method of detecting repeating earthquake. This method utilizes only band-limited phase information and yields the correlation values between two seismic signals. Secondly, we employ coherence function using three orthogonal components (East-West, North-South, and Up-Down) of seismic data as a

  2. Acceleration of Electron Repulsion Integral Evaluation on Graphics Processing Units via Use of Recurrence Relations.

    PubMed

    Miao, Yipu; Merz, Kenneth M

    2013-02-12

    Electron repulsion integral (ERI) calculation on graphical processing units (GPUs) can significantly accelerate quantum chemical calculations. Herein, the ab initio self-consistent-field (SCF) calculation is implemented on GPUs using recurrence relations, which is one of the fastest ERI evaluation algorithms currently available. A direct-SCF scheme to assemble the Fock matrix efficiently is presented, wherein ERIs are evaluated on-the-fly to avoid CPU-GPU data transfer, a well-known architectural bottleneck in GPU specific computation. Realized speedups on GPUs reach 10-100 times relative to traditional CPU nodes, with accuracies of better than 1 × 10(-7) for systems with more than 4000 basis functions. PMID:26588740

  3. Functionalization of gadolinium metallofullerenes for detecting atherosclerotic plaque lesions by cardiovascular magnetic resonance

    PubMed Central

    2013-01-01

    Background The hallmark of atherosclerosis is the accumulation of plaque in vessel walls. This process is initiated when monocytic cells differentiate into macrophage foam cells under conditions with high levels of atherogenic lipoproteins. Vulnerable plaque can dislodge, enter the blood stream, and result in acute myocardial infarction and stroke. Imaging techniques such as cardiovascular magnetic resonance (CMR) provides one strategy to identify patients with plaque accumulation. Methods We synthesized an atherosclerotic-targeting contrast agent (ATCA) in which gadolinium (Gd)-containing endohedrals were functionalized and formulated into liposomes with CD36 ligands intercalated into the lipid bilayer. In vitro assays were used to assess the specificity of the ATCA for foam cells. The ability of ATCA to detect atherosclerotic plaque lesions in vivo was assessed using CMR. Results The ATCA was able to detect scavenger receptor (CD36)-expressing foam cells in vitro and were specifically internalized via the CD36 receptor as determined by focused ion beam/scanning electron microscopy (FIB-SEM) and Western blotting analysis of CD36 receptor-specific signaling pathways. The ATCA exhibited time-dependent accumulation in atherosclerotic plaque lesions of ApoE −/− mice as determined using CMR. No ATCA accumulation was observed in vessels of wild type (C57/b6) controls. Non-targeted control compounds, without the plaque-targeting moieties, were not taken up by foam cells in vitro and did not bind plaque in vivo. Importantly, the ATCA injection was well tolerated, did not demonstrate toxicity in vitro or in vivo, and no accumulation was observed in the major organs. Conclusions The ATCA is specifically internalized by CD36 receptors on atherosclerotic plaque providing enhanced visualization of lesions under physiological conditions. These ATCA may provide new tools for physicians to non-invasively detect atherosclerotic disease. PMID:23324435

  4. Grating interferometry-based phase microtomography of atherosclerotic human arteries

    NASA Astrophysics Data System (ADS)

    Buscema, Marzia; Holme, Margaret N.; Deyhle, Hans; Schulz, Georg; Schmitz, Rüdiger; Thalmann, Peter; Hieber, Simone E.; Chicherova, Natalia; Cattin, Philippe C.; Beckmann, Felix; Herzen, Julia; Weitkamp, Timm; Saxer, Till; Müller, Bert

    2014-09-01

    Cardiovascular diseases are the number one cause of death and morbidity in the world. Understanding disease development in terms of lumen morphology and tissue composition of constricted arteries is essential to improve treatment and patient outcome. X-ray tomography provides non-destructive three-dimensional data with micrometer-resolution. However, a common problem is simultaneous visualization of soft and hard tissue-containing specimens, such as atherosclerotic human coronary arteries. Unlike absorption based techniques, where X-ray absorption strongly depends on atomic number and tissue density, phase contrast methods such as grating interferometry have significant advantages as the phase shift is only a linear function of the atomic number. We demonstrate that grating interferometry-based phase tomography is a powerful method to three-dimensionally visualize a variety of anatomical features in atherosclerotic human coronary arteries, including plaque, muscle, fat, and connective tissue. Three formalin-fixed, human coronary arteries were measured using advanced laboratory μCT. While this technique gives information about plaque morphology, it is impossible to extract the lumen morphology. Therefore, selected regions were measured using grating based phase tomography, sinograms were treated with a wavelet-Fourier filter to remove ring artifacts, and reconstructed data were processed to allow extraction of vessel lumen morphology. Phase tomography data in combination with conventional laboratory μCT data of the same specimen shows potential, through use of a joint histogram, to identify more tissue types than either technique alone. Such phase tomography data was also rigidly registered to subsequently decalcified arteries that were histologically sectioned, although the quality of registration was insufficient for joint histogram analysis.

  5. Microcalcifications in atherosclerotic lesion of apolipoprotein E-deficient mouse

    PubMed Central

    Debernardi, Nicola; Roijers, Ruben B; Krams, Rob; de Crom, Rini; Mutsaers, Peter HA; van der Vusse, Ger J

    2010-01-01

    Evidence is accumulating that calcium-rich microdeposits in the vascular wall might play a crucial role in the onset and progression of atherosclerosis. Here we investigated an atherosclerotic lesion of the carotid artery in an established murine model, i.e. the apolipoprotein E-deficient (APOE−/−) mouse to identify (i) the presence of microcalcifications, if any, (ii) the elemental composition of microcalcifications with special reference to calcium/phosphorus mass ratio and (iii) co-localization of increased concentrations of iron and zinc with microcalcifications. Atherosclerosis was induced by a flow-divider placed around the carotid artery resulting in low and high shear-stress regions. Element composition was assessed with a proton microprobe. Microcalcifications, predominantly present in the thickened intima of the low shear-stress region, were surrounded by areas with normal calcium levels, indicating that calcium-precipitation is a local event. The diameter of intimal microcalcifications varied from 6 to 70 μm. Calcium/phosphorus ratios of microcalcifications varied from 0.3 to 4.8, mainly corresponding to the ratio of amorphous calcium-phosphate. Increased iron and zinc concentrations commonly co-localized with microcalcifications. Our findings indicate that the atherosclerotic process in the murine carotid artery is associated with locally accumulated calcium, iron and zinc. The calcium-rich deposits resemble amorphous calcium phosphate rather than pure hydroxyapatite. We propose that the APOE−/− mouse, in which atherosclerosis was evoked by a flow-divider, offers a useful model to investigate the pathophysiological significance of accumulation of elements such as calcium, iron and zinc. PMID:20804542

  6. Stochastic Modeling and Analysis of Multiple Nonlinear Accelerated Degradation Processes through Information Fusion

    PubMed Central

    Sun, Fuqiang; Liu, Le; Li, Xiaoyang; Liao, Haitao

    2016-01-01

    Accelerated degradation testing (ADT) is an efficient technique for evaluating the lifetime of a highly reliable product whose underlying failure process may be traced by the degradation of the product’s performance parameters with time. However, most research on ADT mainly focuses on a single performance parameter. In reality, the performance of a modern product is usually characterized by multiple parameters, and the degradation paths are usually nonlinear. To address such problems, this paper develops a new s-dependent nonlinear ADT model for products with multiple performance parameters using a general Wiener process and copulas. The general Wiener process models the nonlinear ADT data, and the dependency among different degradation measures is analyzed using the copula method. An engineering case study on a tuner’s ADT data is conducted to demonstrate the effectiveness of the proposed method. The results illustrate that the proposed method is quite effective in estimating the lifetime of a product with s-dependent performance parameters. PMID:27509499

  7. Variability of Mass Dependence of Auroral Acceleration Processes with Solar Activity

    NASA Technical Reports Server (NTRS)

    Ghielmetti, Arthur G.

    1997-01-01

    The objectives of this investigation are to improve understanding of the mass dependent variability of the auroral acceleration processes and so to clarify apparent discrepancies regarding the altitude and local time variations with solar cycle by investigating: (1) the global morphological relationships between auroral electric field structures and the related particle signatures under varying conditions of solar activity, and (2) the relationships between the electric field structures and particle signatures in selected events that are representative of the different conditions occurring during a solar cycle. The investigation is based in part on the Lockheed UFI data base of UpFlowing Ion (UFI) events in the 5OO eV to 16keV energy range and associated electrons in the energy range 7O eV to 24 keV. This data base was constructed from data acquired by the ion mass spectrometer on the S3-3 satellite in the altitude range of I to 1.3 Re. The launch of the POLAR spacecraft in early 1996 and successful operation of its TIMAS ion mass spectrometer has provided us with data from within the auroral acceleration regions during the current solar minimum. The perigee of POLAR is at about 1 Re, comparable to that of S3-3. The higher sensitivity and time resolution of TIMAS compared to the ion mass spectrometer on S3-3 together with its wider energy range, 15 eV to 33 keV, facilitate more detailed studies of upflowing ions.

  8. The tolls and dangers of atherosclerotic disease.

    PubMed

    Monaco, Claudia

    2012-01-01

    Inflammation drives atherosclerosis. Toll-like receptor-2 and -4 are so far the strongest candidates for initiating innate immune signalling in atherosclerosis. Their signalling has implications for lesion development, foam cell formation, inflammation, matrix degradation and ischemia-reperfusion. The repertoire of TLR agonists is expanding. They collectively represent a conglomerate of structurally diverse molecular patterns requiring a high level of versatility in their sensing. Such versatility is achieved through cooperation of TLR heterodimers, co-receptors, and binding proteins. Several endogenous and exogenous molecular patterns engaging TLRs are associated with atherosclerosis development and complications. In this review, I describe how such molecular patterns are sensed, how they signal and what the consequences in the atherosclerotic plaque might be. The effect of TLR antagonising compounds in human and murine atherosclerosis is also addressed.

  9. Acceleration of iterative Navier-Stokes solvers on graphics processing units

    NASA Astrophysics Data System (ADS)

    Tomczak, Tadeusz; Zadarnowska, Katarzyna; Koza, Zbigniew; Matyka, Maciej; Mirosław, Łukasz

    2013-04-01

    While new power-efficient computer architectures exhibit spectacular theoretical peak performance, they require specific conditions to operate efficiently, which makes porting complex algorithms a challenge. Here, we report results of the semi-implicit method for pressure linked equations (SIMPLE) and the pressure implicit with operator splitting (PISO) methods implemented on the graphics processing unit (GPU). We examine the advantages and disadvantages of the full porting over a partial acceleration of these algorithms run on unstructured meshes. We found that the full-port strategy requires adjusting the internal data structures to the new hardware and proposed a convenient format for storing internal data structures on GPUs. Our implementation is validated on standard steady and unsteady problems and its computational efficiency is checked by comparing its results and run times with those of some standard software (OpenFOAM) run on central processing unit (CPU). The results show that a server-class GPU outperforms a server-class dual-socket multi-core CPU system running essentially the same algorithm by up to a factor of 4.

  10. In Vivo Hypobaric Hypoxia Performed During the Remodeling Process Accelerates Bone Healing in Mice

    PubMed Central

    Durand, Marjorie; Collombet, Jean-Marc; Frasca, Sophie; Begot, Laurent; Lataillade, Jean-Jacques; Le Bousse-Kerdilès, Marie-Caroline

    2014-01-01

    We investigated the effects of respiratory hypobaric hypoxia on femoral bone-defect repair in mice because hypoxia is believed to influence both mesenchymal stromal cell (MSC) and hematopoietic stem cell mobilization, a process involved in the bone-healing mechanism. To mimic conditions of non-weight-bearing limb immobilization in patients suffering from bone trauma, our hypoxic mouse model was further subjected to hind-limb unloading. A hole was drilled in the right femur of adult male C57/BL6J mice. Four days after surgery, mice were subjected to hind-limb unloading for 1 week. Seven days after surgery, mice were either housed for 4 days in a hypobaric room (FiO2 at 10%) or kept under normoxic conditions. Unsuspended control mice were housed in either hypobaric or normoxic conditions. Animals were sacrificed on postsurgery day 11 to allow for collection of both contralateral and lesioned femurs, blood, and spleen. As assessed by microtomography, delayed hypoxia enhanced bone-healing efficiency by increasing the closing of the cortical defect and the newly synthesized bone volume in the cavity by +55% and +35%, respectively. Proteome analysis and histomorphometric data suggested that bone-repair improvement likely results from the acceleration of the natural bone-healing process rather than from extended mobilization of MSC-derived osteoprogenitors. Hind-limb unloading had hardly any effect beyond delayed hypoxia-enhanced bone-healing efficiency. PMID:24944208

  11. Vibrotactile masking experiments reveal accelerated somatosensory processing in congenitally blind Braille readers

    PubMed Central

    Bhattacharjee, Arindam; Ye, Amanda J.; Lisak, Joy A.; Vargas, Maria G.; Goldreich, Daniel

    2010-01-01

    Braille reading is a demanding task that requires the identification of rapidly varying tactile patterns. During proficient reading, neighboring characters impact the fingertip at about 100-ms intervals, and adjacent raised dots within a character at 50-ms intervals. Because the brain requires time to interpret afferent sensorineural activity, among other reasons, tactile stimuli separated by such short temporal intervals pose a challenge to perception. How, then, do proficient Braille readers successfully interpret inputs arising from their fingertips at such rapid rates? We hypothesized that somatosensory perceptual consolidation occurs more rapidly in proficient Braille readers. If so, Braille readers should outperform sighted participants on masking tasks, which demand rapid perceptual processing, but would not necessarily outperform the sighted on tests of simple vibrotactile sensitivity. To investigate, we conducted two-interval forced-choice vibrotactile detection, amplitude discrimination, and masking tasks on the index fingertips of 89 sighted and 57 profoundly blind humans. Sighted and blind participants had similar unmasked detection (25-ms target tap) and amplitude discrimination (compared to 100-micron reference tap) thresholds, but congenitally blind Braille readers, the fastest readers among the blind participants, exhibited significantly less masking than the sighted (masker: 50-Hz, 50-micron; target-masker delays ±50 and ±100 ms). Indeed, Braille reading speed correlated significantly and specifically with masking task performance, and in particular with the backward masking decay time constant. We conclude that vibrotactile sensitivity is unchanged, but that perceptual processing is accelerated in congenitally blind Braille readers. PMID:20980584

  12. Vibrotactile masking experiments reveal accelerated somatosensory processing in congenitally blind braille readers.

    PubMed

    Bhattacharjee, Arindam; Ye, Amanda J; Lisak, Joy A; Vargas, Maria G; Goldreich, Daniel

    2010-10-27

    Braille reading is a demanding task that requires the identification of rapidly varying tactile patterns. During proficient reading, neighboring characters impact the fingertip at ∼100 ms intervals, and adjacent raised dots within a character at 50 ms intervals. Because the brain requires time to interpret afferent sensorineural activity, among other reasons, tactile stimuli separated by such short temporal intervals pose a challenge to perception. How, then, do proficient Braille readers successfully interpret inputs arising from their fingertips at such rapid rates? We hypothesized that somatosensory perceptual consolidation occurs more rapidly in proficient Braille readers. If so, Braille readers should outperform sighted participants on masking tasks, which demand rapid perceptual processing, but would not necessarily outperform the sighted on tests of simple vibrotactile sensitivity. To investigate, we conducted two-interval forced-choice vibrotactile detection, amplitude discrimination, and masking tasks on the index fingertips of 89 sighted and 57 profoundly blind humans. Sighted and blind participants had similar unmasked detection (25 ms target tap) and amplitude discrimination (compared with 100 μm reference tap) thresholds, but congenitally blind Braille readers, the fastest readers among the blind participants, exhibited significantly less masking than the sighted (masker, 50 Hz, 50 μm; target-masker delays, ±50 and ±100 ms). Indeed, Braille reading speed correlated significantly and specifically with masking task performance, and in particular with the backward masking decay time constant. We conclude that vibrotactile sensitivity is unchanged but that perceptual processing is accelerated in congenitally blind Braille readers.

  13. Graphics Processing Unit (GPU) Acceleration of the Goddard Earth Observing System Atmospheric Model

    NASA Technical Reports Server (NTRS)

    Putnam, Williama

    2011-01-01

    The Goddard Earth Observing System 5 (GEOS-5) is the atmospheric model used by the Global Modeling and Assimilation Office (GMAO) for a variety of applications, from long-term climate prediction at relatively coarse resolution, to data assimilation and numerical weather prediction, to very high-resolution cloud-resolving simulations. GEOS-5 is being ported to a graphics processing unit (GPU) cluster at the NASA Center for Climate Simulation (NCCS). By utilizing GPU co-processor technology, we expect to increase the throughput of GEOS-5 by at least an order of magnitude, and accelerate the process of scientific exploration across all scales of global modeling, including: The large-scale, high-end application of non-hydrostatic, global, cloud-resolving modeling at 10- to I-kilometer (km) global resolutions Intermediate-resolution seasonal climate and weather prediction at 50- to 25-km on small clusters of GPUs Long-range, coarse-resolution climate modeling, enabled on a small box of GPUs for the individual researcher After being ported to the GPU cluster, the primary physics components and the dynamical core of GEOS-5 have demonstrated a potential speedup of 15-40 times over conventional processor cores. Performance improvements of this magnitude reduce the required scalability of 1-km, global, cloud-resolving models from an unfathomable 6 million cores to an attainable 200,000 GPU-enabled cores.

  14. Retrospective analysis of linear accelerator output constancy checks using process control techniques.

    PubMed

    Sanghangthum, Taweap; Suriyapee, Sivalee; Srisatit, Somyot; Pawlicki, Todd

    2013-01-01

    Shewhart control charts have previously been suggested as a process control tool for use in routine linear accelerator (linac) output verifications. However, a comprehensive approach to process control has not been investigated for linac output verifications. The purpose of this work is to investigate a comprehensive process control approach to linac output constancy quality assurance (QA). The RBA-3 dose constancy check was used to verify outputs of photon beams and electron beams delivered by a Varian Clinac 21EX linac. The data were collected during 2009 to 2010. Shewhart-type control charts, exponentially weighted moving average (EWMA) charts, and capability indices were applied to these processes. The Shewhart-type individuals chart (X-chart) was used and the number of data points used to calculate the control limits was varied. The parameters tested for the EWMA charts (smoothing parameter (λ) and the control limit width (L)) were λ = 0.05, L = 2.492; λ = 0.10, L = 2.703; and λ = 0.20, L = 2.860, as well as the number of points used to estimate the initial process mean and variation. Lastly, the number of in-control data points used to determine process capability (C(p)) and acceptability (C(pk)) were investigated, comparing the first in-control run to the longest in-control run of the process data. C(p) and C(pk) values greater than 1.0 were considered acceptable. The 95% confidence intervals were reported. The X-charts detected systematic errors (e.g., device setup errors). In-control run lengths on the X-charts varied from 5 to 30 output measurements (about one to seven months). EWMA charts showed in-control runs ranging from 9 to 33 output measurements (about two to eight months). The C(p) and C(pk) ratios are higher than 1.0 for all energies, except 12 and 20 MeV. However, 10 MV and 6, 9, and 16 MeV were in question when considering the 95% confidence limits. The X-chart should be calculated using 8-12 data points. For EWMA chart, using 4 data points

  15. Project Zero Delay: a process for accelerating the activation of cancer clinical trials.

    PubMed

    Kurzrock, Razelle; Pilat, Susan; Bartolazzi, Marcel; Sanders, Dwana; Van Wart Hood, Jill; Tucker, Stanley D; Webster, Kevin; Mallamaci, Michael A; Strand, Steven; Babcock, Eileen; Bast, Robert C

    2009-09-10

    Drug development in cancer research is lengthy and expensive. One of the rate-limiting steps is the initiation of first-in-human (phase I) trials. Three to 6 months can elapse between investigational new drug (IND) approval by the US Food and Drug Administration and the entry of a first patient. Issues related to patient participation have been well analyzed, but the administrative processes relevant to implementing clinical trials have received less attention. While industry and academia often partner for the performance of phase I studies, their administrative processes are generally performed independently, and their timelines driven by different priorities: safety reviews, clinical operations, regulatory submissions, and contracting of clinical delivery vendors for industry; contracts, budgets, and institutional review board approval for academia. Both processes converge on US Food and Drug Administration approval of an IND. In the context of a strategic alliance between M. D. Anderson Cancer Center and AstraZeneca Pharmaceuticals LP, a concerted effort has been made to eliminate delays in implementing clinical trials. These efforts focused on close communications, identifying and matching key timelines, alignment of priorities, and tackling administrative processes in parallel, rather than sequentially. In a recent, first-in-human trial, the study was activated and the first patient identified in 46 days from completion of the final study protocol and about 48 hours after final US Food and Drug Administration IND approval, reducing the overall timeline by about 3 months, while meeting all clinical good practice guidelines. Eliminating administrative delays can accelerate the evaluation of new drugs without compromising patient safety or the quality of clinical research. PMID:19652061

  16. Therapeutic strategies to deplete macrophages in atherosclerotic plaques

    PubMed Central

    De Meyer, Inge; Martinet, Wim; De Meyer, Guido R. Y.

    2012-01-01

    Macrophages can be found in all stages of atherosclerosis and are major contributors of atherosclerotic plaque development, progression and destabilization. Continuous recruitment of monocytes drives this chronic inflammatory disease, which can be intervened by several strategies: reducing the inflammatory stimulus by lowering circulating lipids and promoting cholesterol efflux from plaque, direct and indirect targeting of adhesion molecules and chemokines involved in monocyte adhesion and transmigration and inducing macrophage death in atherosclerotic plaques in combination with anti-inflammatory drugs. This review discusses the outlined strategies to deplete macrophages from atherosclerotic plaques to promote plaque stabilization. PMID:22309283

  17. The NF-κB pathway: regulation of the instability of atherosclerotic plaques activated by Fg, Fb, and FDPs.

    PubMed

    Cao, Yongjun; Zhou, Xiaomei; Liu, Huihui; Zhang, Yanlin; Yu, Xiaoyan; Liu, Chunfeng

    2013-11-01

    Recently, the molecular mechanism responsible for the instability of atherosclerotic plaques has gradually become a hot topic among researchers and clinicians. Matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) play an important role in the processes of formation and development of atherosclerosis. In this study, we established and employed the transwell co-culture system of rabbit aortic endothelial cells and smooth muscle cells to explore the relationship between fibrin (Fb), fibrinogen (Fg), and/or their degradation products (FDPs) in relation to the instability of atherosclerotic plaques; meanwhile, we observed the effects of Fg, Fb, and FDPs on the mRNA levels of MMPs and VEGF as well as on the activation of nuclear factor-kappa B (NF-κB). We concluded that Fb, Fg, and FDPs are involved in the progression of the instability of atherosclerotic plaques via increasing the expression of MMPs and VEGF. This effect might be mediated by the NF-кB pathway.

  18. Bisphenol A exposure accelerated the aging process in the nematode Caenorhabditis elegans.

    PubMed

    Tan, Ling; Wang, Shunchang; Wang, Yun; He, Mei; Liu, Dahai

    2015-06-01

    Bisphenol A (BPA) is a well-known environmental estrogenic disruptor that causes adverse effects. Recent studies have found that chronic exposure to BPA is associated with a high incidence of several age-related diseases. Aging is characterized by progressive function decline, which affects quality of life. However, the effects of BPA on the aging process are largely unknown. In the present study, by using the nematode Caenorhabditis elegans as a model, we investigated the influence of BPA exposure on the aging process. The decrease in body length, fecundity, and population size and the increased egg laying defection suggested that BPA exposure resulted in fitness loss and reproduction aging in this animal. Lifetime exposure of worms to BPA shortened the lifespan in a dose-dependant manner. Moreover, prolonged BPA exposure resulted in age-related behavior degeneration and the accumulation of lipofuscin and lipid peroxide products. The expression of mitochondria-specific HSP-6 and endoplasmic reticulum (ER)-related HSP-70 exhibited hormetic decrease. The expression of ER-related HSP-4 decreased significantly while HSP-16.2 showed a dose-dependent increase. The decreased expression of GCS-1 and GST-4 implicated the reduced antioxidant ability under BPA exposure, and the increase in SOD-3 expression might be caused by elevated levels of reactive oxygen species (ROS) production. Finally, BPA exposure increased the generation of hydrogen peroxide-related ROS and superoxide anions. Our results suggest that BPA exposure resulted in an accelerated aging process in C. elegans mediated by the induction of oxidative stress.

  19. A remediation contractor`s view of accelerating the cleanup process

    SciTech Connect

    Librizzi, W.J.; Phelps, G.S.

    1994-12-31

    Superfund, since its passage in December, 1980, has been under continual evaluation and change. Progress has been made over the past 13 years. To date, EPA under Superfund has completed 220 long term cleanups with 1,100 in various stages of completion. In addition, Superfund has been a catalyst for the development of new innovative cleanup technologies. In this regard, EPA has identified more than 150 innovative technologies now being used to treat contaminated soil, groundwater, sludge and sediments. Despite these noted accomplishments, continued criticisms of the program focus on Superfund weaknesses. They include: inconsistent cleanups; high transactional costs; perceived unfairness in liability; overlapping federal/state relationship; Inadequate community involvement; impediments to economic development. Techniques that can accelerate the hazardous waste cleanup process are discussed further in this paper. They include: strengthened interrelationships between the design and remediation contractors; role of the remediation contractor in the implementation of presumptive remedies; a proactive community relations program, partnering and early and frequent interface with regulatory agencies.

  20. Graphics processing unit accelerated one-dimensional blood flow computation in the human arterial tree.

    PubMed

    Itu, Lucian; Sharma, Puneet; Kamen, Ali; Suciu, Constantin; Comaniciu, Dorin

    2013-12-01

    One-dimensional blood flow models have been used extensively for computing pressure and flow waveforms in the human arterial circulation. We propose an improved numerical implementation based on a graphics processing unit (GPU) for the acceleration of the execution time of one-dimensional model. A novel parallel hybrid CPU-GPU algorithm with compact copy operations (PHCGCC) and a parallel GPU only (PGO) algorithm are developed, which are compared against previously introduced PHCG versions, a single-threaded CPU only algorithm and a multi-threaded CPU only algorithm. Different second-order numerical schemes (Lax-Wendroff and Taylor series) are evaluated for the numerical solution of one-dimensional model, and the computational setups include physiologically motivated non-periodic (Windkessel) and periodic boundary conditions (BC) (structured tree) and elastic and viscoelastic wall laws. Both the PHCGCC and the PGO implementations improved the execution time significantly. The speed-up values over the single-threaded CPU only implementation range from 5.26 to 8.10 × , whereas the speed-up values over the multi-threaded CPU only implementation range from 1.84 to 4.02 × . The PHCGCC algorithm performs best for an elastic wall law with non-periodic BC and for viscoelastic wall laws, whereas the PGO algorithm performs best for an elastic wall law with periodic BC.

  1. Closing the gap: accelerating the translational process in nanomedicine by proposing standardized characterization techniques

    PubMed Central

    Khorasani, Ali A; Weaver, James L; Salvador-Morales, Carolina

    2014-01-01

    On the cusp of widespread permeation of nanomedicine, academia, industry, and government have invested substantial financial resources in developing new ways to better treat diseases. Materials have unique physical and chemical properties at the nanoscale compared with their bulk or small-molecule analogs. These unique properties have been greatly advantageous in providing innovative solutions for medical treatments at the bench level. However, nanomedicine research has not yet fully permeated the clinical setting because of several limitations. Among these limitations are the lack of universal standards for characterizing nanomaterials and the limited knowledge that we possess regarding the interactions between nanomaterials and biological entities such as proteins. In this review, we report on recent developments in the characterization of nanomaterials as well as the newest information about the interactions between nanomaterials and proteins in the human body. We propose a standard set of techniques for universal characterization of nanomaterials. We also address relevant regulatory issues involved in the translational process for the development of drug molecules and drug delivery systems. Adherence and refinement of a universal standard in nanomaterial characterization as well as the acquisition of a deeper understanding of nanomaterials and proteins will likely accelerate the use of nanomedicine in common practice to a great extent. PMID:25525356

  2. Acceleration of High Angular Momentum Electron Repulsion Integrals and Integral Derivatives on Graphics Processing Units.

    PubMed

    Miao, Yipu; Merz, Kenneth M

    2015-04-14

    We present an efficient implementation of ab initio self-consistent field (SCF) energy and gradient calculations that run on Compute Unified Device Architecture (CUDA) enabled graphical processing units (GPUs) using recurrence relations. We first discuss the machine-generated code that calculates the electron-repulsion integrals (ERIs) for different ERI types. Next we describe the porting of the SCF gradient calculation to GPUs, which results in an acceleration of the computation of the first-order derivative of the ERIs. However, only s, p, and d ERIs and s and p derivatives could be executed simultaneously on GPUs using the current version of CUDA and generation of NVidia GPUs using a previously described algorithm [Miao and Merz J. Chem. Theory Comput. 2013, 9, 965-976.]. Hence, we developed an algorithm to compute f type ERIs and d type ERI derivatives on GPUs. Our benchmarks shows the performance GPU enable ERI and ERI derivative computation yielded speedups of 10-18 times relative to traditional CPU execution. An accuracy analysis using double-precision calculations demonstrates that the overall accuracy is satisfactory for most applications. PMID:26574356

  3. Graphics processing unit accelerated one-dimensional blood flow computation in the human arterial tree.

    PubMed

    Itu, Lucian; Sharma, Puneet; Kamen, Ali; Suciu, Constantin; Comaniciu, Dorin

    2013-12-01

    One-dimensional blood flow models have been used extensively for computing pressure and flow waveforms in the human arterial circulation. We propose an improved numerical implementation based on a graphics processing unit (GPU) for the acceleration of the execution time of one-dimensional model. A novel parallel hybrid CPU-GPU algorithm with compact copy operations (PHCGCC) and a parallel GPU only (PGO) algorithm are developed, which are compared against previously introduced PHCG versions, a single-threaded CPU only algorithm and a multi-threaded CPU only algorithm. Different second-order numerical schemes (Lax-Wendroff and Taylor series) are evaluated for the numerical solution of one-dimensional model, and the computational setups include physiologically motivated non-periodic (Windkessel) and periodic boundary conditions (BC) (structured tree) and elastic and viscoelastic wall laws. Both the PHCGCC and the PGO implementations improved the execution time significantly. The speed-up values over the single-threaded CPU only implementation range from 5.26 to 8.10 × , whereas the speed-up values over the multi-threaded CPU only implementation range from 1.84 to 4.02 × . The PHCGCC algorithm performs best for an elastic wall law with non-periodic BC and for viscoelastic wall laws, whereas the PGO algorithm performs best for an elastic wall law with periodic BC. PMID:24009129

  4. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway.

    PubMed

    Tooker, Brian C; Brindley, Stephen M; Chiarappa-Zucca, Marina L; Turteltaub, Kenneth W; Newman, Lee S

    2015-01-01

    Exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, it was determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) than HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.

  5. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway

    SciTech Connect

    Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.; Turteltaub, Kenneth W.; Newman, Lee S.

    2014-06-16

    We report that exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, we determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.

  6. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway

    DOE PAGES

    Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.; Turteltaub, Kenneth W.; Newman, Lee S.

    2014-06-16

    We report that exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstratemore » that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, we determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.« less

  7. Shape-based segmentation and visualization techniques for evaluation of atherosclerotic plaques in coronary artery disease

    NASA Astrophysics Data System (ADS)

    Rinck, Daniel; Krüger, Sebastian; Reimann, Anja; Scheuering, Michael

    2006-03-01

    Multi-slice computed tomography (MSCT) has developed strongly in the emerging field of cardiovascular imaging. The manual analysis of atherosclerotic plaques in coronary arteries is a very time consuming and labor intensive process and today only qualitative analysis is possible. In this paper we present a new shape-based segmentation and visualization technique for quantitative analysis of atherosclerotic plaques in coronary artery disease. The new technique takes into account several aspects of the vascular anatomy. It uses two surface representations, one for the contrast filled vessel lumen and also one for the vascular wall. The deviation between these two surfaces is defined as plaque volume. These surface representations can be edited by the user manually. With this kind of representation it is possible to calculate sub plaque volumes (such as: lipid rich core, fibrous tissue, calcified tissue) inside this suspicious area. Also a high quality 3D visualization, using Open Inventor is possible.

  8. Atherosclerotic renovascular disease in the United States.

    PubMed

    Kalra, Philip A; Guo, Haifeng; Gilbertson, David T; Liu, Jiannong; Chen, Shu-Cheng; Ishani, Areef; Collins, Allan J; Foley, Robert N

    2010-01-01

    Atherosclerotic renovascular disease (ARVD) is an increasingly recognized clinical condition that is diagnosed predominantly in older patients. Here we used annual United States Medicare 5% Denominator Files and studied 16,036,904 patients, 66 years of age and older, to quantify trends in diagnostic rates, associations, treatment, and outcomes of ARVD over a 13-year period. Overall, there was an ARVD rate of 3.09 per 1000 patient-years, which rose progressively with an adjusted hazard ratio of 3.35, comparing data from 1992 to 2004. Within 6 months of disease diagnosis, 13.4% of patients had undergone revascularization. A biphasic pattern of revascularization was found where the adjusted hazard ratios significantly increased in a progressive manner until 1999, following which there was a decline through 2004, which was not significant. The method of revascularization changed markedly over time with endovascular intervention steadily replacing direct surgical revascularization. As a time-dependent variable, ARVD was associated with excess mortality in each calendar year, albeit with declining hazard ratio estimates in more recent years. Among patients with this disease, revascularization was associated with mortality adjusted hazard ratios <1 in each year. Our study shows the diagnosis of ARVD has substantially risen in the United States but the survival implications were not fully explained by other comorbid vascular diseases.

  9. Primary Stenting of Intracranial Atherosclerotic Stenoses

    SciTech Connect

    Straube, T. Stingele, Robert; Jansen, Olav

    2005-04-15

    Purpose: To determine the feasibility and safety of stenting intracranial atherosclerotic stenoses.Methods: In 12 patients the results of primary intracranial stenting were evaluated retrospectively. Patient ages ranged from 49 to 79 years (mean 64 years). Six patients presented with stenoses in the anterior circulation, and six had stenosis in the posterior circulation. One patient presented with extra- and intracranial tandem stenosis of the left internal carotid artery. Three patients presented with acute basilar thrombosis, caused by high-grade basilar stenoses.Results: Intracranial stenoses were successfully stented in 11 of 12 patients. In one patient the stent could not be advanced over the carotid siphon to reach the stenosis of the ophthalmic internal carotid artery. Follow-up digital subtraction angiographic studies were obtained in two patients who had presented with new neurologic signs or symptoms. In both cases the angiogram did not show any relevant stenotic endothelial hyperplasia. In one patient, after local thrombolysis the stenosis turned out to be so narrow that balloon angioplasty had to be performed before stent deployment. All three patients treated for stenosis-related basilar thrombosis died due to brainstem infarction that had ensued before the intervention.Conclusions: Prophylactic primary stenting of intracranial stenoses of the anterior or posterior cerebral circulation can be performed with a low complication rate; technical problems such as stent flexibility must still be solved. Local thrombolysis followed by stenting in stenosis-related thrombotic occlusion is technically possible.

  10. Heat Shock Proteins: Mediators of Atherosclerotic Development.

    PubMed

    Deniset, Justin F; Pierce, Grant N

    2015-01-01

    Heat shock proteins play important housekeeping roles in a variety of cells within the body during normal control conditions. The many different functions for heat shock proteins in the cell depend upon the specific heat shock protein involved. Each protein is nominally differentiated based upon its molecular size. However, in addition to their role in normal cell function, heat shock proteins may play an even more important role as pro-survival proteins conserved through evolution to protect the cell from a variety of stresses. The ability of a cell to withstand these environmental stresses is critical to its capacity to adapt and remain viable. Loss of this ability may lead to pathological states. Abnormal localization, structure or function of the heat shock proteins has been associated with many pathologies, including those involving heart disease. Heat shock proteins like HSP60 and HSP70 in particular have been identified as playing important roles in inflammation and immune reactions. Inflammation has been identified recently as an important pathological risk factor for heart disease. It is perhaps not surprising therefore, that heat shock protein family has been increasingly identified as an important intracellular pathway associated with inflammatory-mediated heart conditions including atherosclerosis. This paper reviews the evidence in support of a role for heat shock proteins in cardiovascular disease and the potential to target these proteins to alter the progression of atherosclerotic disease.

  11. Accelerating POCS interpolation of 3D irregular seismic data with Graphics Processing Units

    NASA Astrophysics Data System (ADS)

    Wang, Shu-Qin; Gao, Xing; Yao, Zhen-Xing

    2010-10-01

    Seismic trace interpolation is necessary for high-resolution imaging when the acquired data are not adequate or when some traces are missing. Projection-onto-convex-sets (POCS) interpolation can gradually recover missing traces with an iterative algorithm, but its computational cost in a 3D CPU-based implementation is too high for practical applications. We present a computing scheme to speedup 3D POCS interpolation with graphics processing units (GPUs). We accelerate the most time-consuming part of the 3D POCS algorithm (i.e. Fourier transforms) by taking advantage of a GPU-based Fourier transform library. Other parts are fine-tuned to maximize the utilization of GPU computing resources. We upload the whole input data set to the global memory of the GPUs and reuse it until the final result is obtained. This can avoid low-bandwidth data transfer between CPU and GPUs. We minimize the number of intermediate 3D arrays to save GPU global memory by optimizing the algorithm implementation. This allows us to handle a much larger input data set. When reducing the runtime of our GPU implementation, the coalescing of global memory access and the 3D CUFFT library provides us with the greatest performance improvements. Numerical results show that our scheme is 3-29× times faster than the optimized CPU-based implementation, depending on the size of 3D data set. Our GPU computing scheme allows a significant reduction of computational cost and would facilitate 3D POCS interpolation for practical applications.

  12. Characteristics of four SPE groups with different origins and acceleration processes

    NASA Astrophysics Data System (ADS)

    Kim, R.-S.; Cho, K.-S.; Lee, J.; Bong, S.-C.; Joshi, A. D.; Park, Y.-D.

    2015-09-01

    Solar proton events (SPEs) can be categorized into four groups based on their associations with flare or CME inferred from onset timings as well as acceleration patterns using multienergy observations. In this study, we have investigated whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find the following: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (> 5000 particle flux per unit (pfu)) even if its associated flare and/or CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. (ii) For the former (Group A), the sites are very low (˜ 1 Rs) and close to the western limb, while the latter (Group C) have relatively higher (mean = 6.05 Rs) and wider acceleration sites. (iii) When the proton acceleration starts from the higher energy (Group B), a SPE tends to be a relatively weak event (< 1000 pfu), although its associated CME is relatively stronger than previous groups. (iv) The SPEs categorized by the simultaneous acceleration in whole energy range within 10 min (Group D) tend to show the weakest proton flux (mean = 327 pfu) in spite of strong associated eruptions. Based on those results, we suggest that the different characteristics of SPEs are mainly due to the different conditions of magnetic connectivity and particle density, which are changed with longitude and height as well as their origin.

  13. Effect of Watermarking on Diagnostic Preservation of Atherosclerotic Ultrasound Video in Stroke Telemedicine.

    PubMed

    Dey, Nilanjan; Bose, Soumyo; Das, Achintya; Chaudhuri, Sheli Sinha; Saba, Luca; Shafique, Shoaib; Nicolaides, Andrew; Suri, Jasjit S

    2016-04-01

    Embedding of diagnostic and health care information requires secure encryption and watermarking. This research paper presents a comprehensive study for the behavior of some well established watermarking algorithms in frequency domain for the preservation of stroke-based diagnostic parameters. Two different sets of watermarking algorithms namely: two correlation-based (binary logo hiding) and two singular value decomposition (SVD)-based (gray logo hiding) watermarking algorithms are used for embedding ownership logo. The diagnostic parameters in atherosclerotic plaque ultrasound video are namely: (a) bulb identification and recognition which consists of identifying the bulb edge points in far and near carotid walls; (b) carotid bulb diameter; and (c) carotid lumen thickness all along the carotid artery. The tested data set consists of carotid atherosclerotic movies taken under IRB protocol from University of Indiana Hospital, USA-AtheroPoint™ (Roseville, CA, USA) joint pilot study. ROC (receiver operating characteristic) analysis was performed on the bulb detection process that showed an accuracy and sensitivity of 100 % each, respectively. The diagnostic preservation (DPsystem) for SVD-based approach was above 99 % with PSNR (Peak signal-to-noise ratio) above 41, ensuring the retention of diagnostic parameter devalorization as an effect of watermarking. Thus, the fully automated proposed system proved to be an efficient method for watermarking the atherosclerotic ultrasound video for stroke application.

  14. Positron emission tomography of the vulnerable atherosclerotic plaque in man – a contemporary review

    PubMed Central

    Pedersen, Sune F; Hag, Anne Mette F; Klausen, Thomas L; Ripa, Rasmus S; Bodholdt, Rasmus P; Kjær, Andreas

    2014-01-01

    Atherosclerosis is the primary underlying cause of cardiovascular disease (CVD). It is the leading cause of morbidity and mortality in the Western world today and is set to become the prevailing disease and major cause of death worldwide by 2020. In the 1950s surgical intervention was introduced to treat symptomatic patients with high-grade carotid artery stenosis due to atherosclerosis – a procedure known as carotid endarterectomy (CEA). By removing the atherosclerotic plaque from the affected carotid artery of these patients, CEA is beneficial by preventing subsequent ipsilateral ischemic stroke. However, it is known that patients with low to intermediate artery stenosis may still experience ischemic events, leading clinicians to consider plaque composition as an important feature of atherosclerosis. Today molecular imaging can be used for characterization, visualization and quantification of cellular and subcellular physiological processes as they take place in vivo; using this technology we can obtain valuable information on atherosclerostic plaque composition. Applying molecular imaging clinically to atherosclerotic disease therefore has the potential to identify atherosclerotic plaques vulnerable to rupture. This could prove to be an important tool for the selection of patients for CEA surgery in a health system increasingly focused on individualized treatment. This review focuses on current advances and future developments of in vivo atherosclerosis PET imaging in man. PMID:24289282

  15. Piperlongumine inhibits atherosclerotic plaque formation and vascular smooth muscle cell proliferation by suppressing PDGF receptor signaling

    SciTech Connect

    Son, Dong Ju; Kim, Soo Yeon; Han, Seong Su; Kim, Chan Woo; Kumar, Sandeep; Park, Byeoung Soo; Lee, Sung Eun; Yun, Yeo Pyo; Jo, Hanjoong; Park, Young Hyun

    2012-10-19

    Highlights: Black-Right-Pointing-Pointer Anti-atherogenic effect of PL was examined using partial carotid ligation model in ApoE KO mice. Black-Right-Pointing-Pointer PL prevented atherosclerotic plaque development, VSMCs proliferation, and NF-{kappa}B activation. Black-Right-Pointing-Pointer Piperlongumine reduced vascular smooth muscle cell activation through PDGF-R{beta} and NF-{kappa}B-signaling. Black-Right-Pointing-Pointer PL may serve as a new therapeutic molecule for atherosclerosis treatment. -- Abstract: Piperlongumine (piplartine, PL) is an alkaloid found in the long pepper (Piper longum L.) and has well-documented anti-platelet aggregation, anti-inflammatory, and anti-cancer properties; however, the role of PL in prevention of atherosclerosis is unknown. We evaluated the anti-atherosclerotic potential of PL in an in vivo murine model of accelerated atherosclerosis and defined its mechanism of action in aortic vascular smooth muscle cells (VSMCs) in vitro. Local treatment with PL significantly reduced atherosclerotic plaque formation as well as proliferation and nuclear factor-kappa B (NF-{kappa}B) activation in an in vivo setting. PL treatment in VSMCs in vitro showed inhibition of migration and platelet-derived growth factor BB (PDGF-BB)-induced proliferation to the in vivo findings. We further identified that PL inhibited PDGF-BB-induced PDGF receptor beta activation and suppressed downstream signaling molecules such as phospholipase C{gamma}1, extracellular signal-regulated kinases 1 and 2 and Akt. Lastly, PL significantly attenuated activation of NF-{kappa}B-a downstream transcriptional regulator in PDGF receptor signaling, in response to PDGF-BB stimulation. In conclusion, our findings demonstrate a novel, therapeutic mechanism by which PL suppresses atherosclerosis plaque formation in vivo.

  16. Nuclear microscopy of atherosclerotic tissue: A review

    NASA Astrophysics Data System (ADS)

    Watt, Frank; Ren, M. Q.; Xie, J. P.; Tan, B. K. H.; Halliwell, B.

    2001-07-01

    This paper reviews the work carried out in the Research Centre for Nuclear Microscopy, NUS on the role of iron in coronary heart disease, using the technique of nuclear microscopy to determine the levels of iron and other trace elements in the artery wall and lesions. These investigations have indicated that iron may play a significant role in the development of atherosclerosis, probably through the promotion of cytotoxic free radicals leading to the oxidation of low-density lipoprotein (LDL). Using a rabbit model we have observed that early atherosclerotic lesions, induced by feeding the animals on a 1% cholesterol diet, contain increased levels of iron (up to 8 times) compared with the adjacent healthy artery wall. In a follow-up time sequence study, we have shown that iron accumulation occurs at the onset of lesion formation, which takes place around 4-6 weeks after exposure to the 1% cholesterol diet. As the lesions mature, they enlarge to occupy a significant fraction of the artery wall, and at about 16 weeks the lesions begin to show signs of calcification. In an additional experiment, where the cholesterol fed rabbits were kept anaemic through weekly bleeding, the iron content of the artery wall was reduced and the onset of atherogenesis was delayed. In a further investigation, rabbits were fed on a 1% cholesterol diet and after 6 weeks (corresponding to the period of early lesion formation) a test group was subjected to treatment using the iron chelator desferal. Preliminary results indicate that during the treatment with desferal, lesion development was slowed down.

  17. Molecular Imaging of Vulnerable Atherosclerotic Plaques in Animal Models

    PubMed Central

    Gargiulo, Sara; Gramanzini, Matteo; Mancini, Marcello

    2016-01-01

    Atherosclerosis is characterized by intimal plaques of the arterial vessels that develop slowly and, in some cases, may undergo spontaneous rupture with subsequent heart attack or stroke. Currently, noninvasive diagnostic tools are inadequate to screen atherosclerotic lesions at high risk of acute complications. Therefore, the attention of the scientific community has been focused on the use of molecular imaging for identifying vulnerable plaques. Genetically engineered murine models such as ApoE−/− and ApoE−/−Fbn1C1039G+/− mice have been shown to be useful for testing new probes targeting biomarkers of relevant molecular processes for the characterization of vulnerable plaques, such as vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, intercellular adhesion molecule (ICAM)-1, P-selectin, and integrins, and for the potential development of translational tools to identify high-risk patients who could benefit from early therapeutic interventions. This review summarizes the main animal models of vulnerable plaques, with an emphasis on genetically altered mice, and the state-of-the-art preclinical molecular imaging strategies. PMID:27618031

  18. Molecular Imaging of Vulnerable Atherosclerotic Plaques in Animal Models.

    PubMed

    Gargiulo, Sara; Gramanzini, Matteo; Mancini, Marcello

    2016-01-01

    Atherosclerosis is characterized by intimal plaques of the arterial vessels that develop slowly and, in some cases, may undergo spontaneous rupture with subsequent heart attack or stroke. Currently, noninvasive diagnostic tools are inadequate to screen atherosclerotic lesions at high risk of acute complications. Therefore, the attention of the scientific community has been focused on the use of molecular imaging for identifying vulnerable plaques. Genetically engineered murine models such as ApoE(-/-) and ApoE(-/-)Fbn1C1039G(+/-) mice have been shown to be useful for testing new probes targeting biomarkers of relevant molecular processes for the characterization of vulnerable plaques, such as vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, intercellular adhesion molecule (ICAM)-1, P-selectin, and integrins, and for the potential development of translational tools to identify high-risk patients who could benefit from early therapeutic interventions. This review summarizes the main animal models of vulnerable plaques, with an emphasis on genetically altered mice, and the state-of-the-art preclinical molecular imaging strategies. PMID:27618031

  19. Atherosclerotic Renal Artery Stenosis and Hypertension: Pragmatism, Pitfalls, and Perspectives.

    PubMed

    Bavishi, Chirag; de Leeuw, Peter W; Messerli, Franz H

    2016-06-01

    For many years and even decades, a diagnostic work-up to look for a secondary form of hypertension, particularly of renovascular origin, has been a central tenet in medicine. Atherosclerotic renal artery stenosis is considered the most common cause of renovascular hypertension. However, advances in understanding the complex pathophysiology of this condition and the recently documented futility of renal revascularization bring into question whether atherosclerotic renal artery stenosis truly causes "renovascular hypertension." From a clinical point of view, a clear distinction should be made between hypertension associated with atherosclerotic renal artery stenosis and hypertension caused by renal artery stenosis-induced activation of the renin-angiotensin-aldosterone system. Most patients with atherosclerotic renal artery stenosis do not have a form of hypertension that is remediable or improved by angioplasty; to expose them to the cost, inconvenience, and risk of a diagnostic work-up add up to little more than a wild goose chase. However, with very few exceptions, medical therapy with antihypertensives and statins remains the cornerstone for the management of patients with atherosclerotic renal artery stenosis and hypertension.

  20. Ultrafast laser ablation for targeted atherosclerotic plaque removal

    NASA Astrophysics Data System (ADS)

    Lanvin, Thomas; Conkey, Donald B.; Descloux, Laurent; Frobert, Aurelien; Valentin, Jeremy; Goy, Jean-Jacques; Cook, Stéphane; Giraud, Marie-Noelle; Psaltis, Demetri

    2015-07-01

    Coronary artery disease, the main cause of heart disease, develops as immune cells and lipids accumulate into plaques within the coronary arterial wall. As a plaque grows, the tissue layer (fibrous cap) separating it from the blood flow becomes thinner and increasingly susceptible to rupturing and causing a potentially lethal thrombosis. The stabilization and/or treatment of atherosclerotic plaque is required to prevent rupturing and remains an unsolved medical problem. Here we show for the first time targeted, subsurface ablation of atherosclerotic plaque using ultrafast laser pulses. Excised atherosclerotic mouse aortas were ablated with ultrafast near-infrared (NIR) laser pulses. The physical damage was characterized with histological sections of the ablated atherosclerotic arteries from six different mice. The ultrafast ablation system was integrated with optical coherence tomography (OCT) imaging for plaque-specific targeting and monitoring of the resulting ablation volume. We find that ultrafast ablation of plaque just below the surface is possible without causing damage to the fibrous cap, which indicates the potential use of ultrafast ablation for subsurface atherosclerotic plaque removal. We further demonstrate ex vivo subsurface ablation of a plaque volume through a catheter device with the high-energy ultrafast pulse delivered via hollow-core photonic crystal fiber.

  1. Application of infrared fiber optic imaging in atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Guo, Bujin; Casscells, S. W.; Bearman, Gregory H.; McNatt, Janice; Naghevi, Morteza; Malik, Basit A.; Gul, Khawar; Willerson, James T.

    1999-07-01

    Rupture of atherosclerotic plaques - the main cause of heart attach and stokes - is not predictable. Hence even treadmill stress tests fail to detect many persons at risk. Fatal plaques are found at autopsies to be associated with active inflammatory cells. Classically, inflammation is detected by its swelling, red color, pain and heat. We have found that heat accurately locates the dangerous plaques that are significantly warmer then atherosclerotic plaques without the same inflammation. In order to develop a non-surgical method of locating these plaques, an IR fiber optic imaging system has been developed in our laboratory to evalute the causes and effect of heat in atherosclerotic plaques. The fiber optical imagin bundle consists of 900 individual As2S3 chalcogenide glass fibers which transmit IR radiation from 0.7 micrometers 7 micrometers with little energy loss. By combining that with a highly sensitive Indium Antimonide IR focal plane array detector, we are able to obtain thermal graphic images in situ. The temperature heterogeneity of atherosclerotic plaques developed in the arteral of the experimental animal models is under study with the new device. The preliminary experimental results from the animal model are encouraging. The potential of using this new technology in diagnostic evaluation of the vulnerable atherosclerotic plaques is considerable.

  2. Piperlongumine inhibits atherosclerotic plaque formation and vascular smooth muscle cell proliferation by suppressing PDGF receptor signaling

    PubMed Central

    Son, Dong Ju; Kim, Soo Yeon; Han, Seong Su; Kim, Chan Woo; Kumar, Sandeep; Park, Byeoung Soo; Lee, Sung Eun; Yun, Yeo Pyo; Jo, Hanjoong; Park, Young Hyun

    2012-01-01

    Piperlongumine (piplartine, PL) is an alkaloid found in the long pepper (Piper longum L.) and has well-documented anti-platelet aggregation, anti-inflammatory, and anti-cancer properties; however, the role of PL in prevention of atherosclerosis is unknown. We evaluated the anti-atherosclerotic potential of PL in an in vivo murine model of accelerated atherosclerosis and defined its mechanism of action in aortic vascular smooth muscle cells (VSMCs) in vitro. Local treatment with PL significantly reduced atherosclerotic plaque formation as well as proliferation and nuclear factor-kappa B (NF-κB) activation in an in vivo setting. PL treatment in VSMCs in vitro showed inhibition of migration and platelet-derived growth factor BB (PDGF-BB)-induced proliferation to the in vivo findings. We further identified that PL inhibited PDGF-BB-induced PDGF receptor beta activation and suppressed downstream signaling molecules such as phospholipase C1, extracellular signal-regulated kinases 1 and 2 and Akt. Lastly, PL significantly attenuated activation of NF-κB—a downstream transcriptional regulator in PDGF receptor signaling, in response to PDGF-BB stimulation. In conclusion, our findings demonstrate a novel, therapeutic mechanism by which PL suppresses atherosclerosis plaque formation in vivo. PMID:22995306

  3. A Rabbit Model of Thrombosis on Atherosclerotic Lesions

    PubMed Central

    Yamashita, Atsushi; Asada, Yujiro

    2011-01-01

    Thrombus formation on a disrupted atherosclerotic plaque is a key event that leads to atherothrombosis. Because thrombus is induced by chemical or physical injury of normal arteries in most animal models of thrombosis, the mechanisms of thrombogenesis and thrombus growth in atherosclerotic vessels should be investigated in diseased arteries of appropriate models. Pathological findings of human atherothrombosis suggest that tissue factor, an initiator of the coagulation cascade, significantly affects enhanced platelet aggregation and fibrin formation after plaque disruption. We established a rabbit model of atherothrombosis based on human pathology in which differences in thrombus formation between normal and atherosclerotic arteries, factors contributing to thrombus growth, and mechanisms of plaque erosion can be investigated. Emerging transgenic and stem cell technologies should also provide an invaluable rabbit experimental model in the near future. PMID:21253503

  4. High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis

    PubMed Central

    Wang, Yi; Qiu, Juhui; Luo, Shisui; Xie, Xiang; Zheng, Yiming; Zhang, Kang; Ye, Zhiyi; Liu, Wanqian; Gregersen, Hans; Wang, Guixue

    2016-01-01

    Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions. PMID:27482467

  5. Molecular dynamics-based virtual screening: accelerating the drug discovery process by high-performance computing.

    PubMed

    Ge, Hu; Wang, Yu; Li, Chanjuan; Chen, Nanhao; Xie, Yufang; Xu, Mengyan; He, Yingyan; Gu, Xinchun; Wu, Ruibo; Gu, Qiong; Zeng, Liang; Xu, Jun

    2013-10-28

    High-performance computing (HPC) has become a state strategic technology in a number of countries. One hypothesis is that HPC can accelerate biopharmaceutical innovation. Our experimental data demonstrate that HPC can significantly accelerate biopharmaceutical innovation by employing molecular dynamics-based virtual screening (MDVS). Without using HPC, MDVS for a 10K compound library with tens of nanoseconds of MD simulations requires years of computer time. In contrast, a state of the art HPC can be 600 times faster than an eight-core PC server is in screening a typical drug target (which contains about 40K atoms). Also, careful design of the GPU/CPU architecture can reduce the HPC costs. However, the communication cost of parallel computing is a bottleneck that acts as the main limit of further virtual screening improvements for drug innovations.

  6. Ab initio nonadiabatic dynamics of multichromophore complexes: a scalable graphical-processing-unit-accelerated exciton framework.

    PubMed

    Sisto, Aaron; Glowacki, David R; Martinez, Todd J

    2014-09-16

    ("fragmenting") a molecular system and then stitching it back together. In this Account, we address both of these problems, the first by using graphical processing units (GPUs) and electronic structure algorithms tuned for these architectures and the second by using an exciton model as a framework in which to stitch together the solutions of the smaller problems. The multitiered parallel framework outlined here is aimed at nonadiabatic dynamics simulations on large supramolecular multichromophoric complexes in full atomistic detail. In this framework, the lowest tier of parallelism involves GPU-accelerated electronic structure theory calculations, for which we summarize recent progress in parallelizing the computation and use of electron repulsion integrals (ERIs), which are the major computational bottleneck in both density functional theory (DFT) and time-dependent density functional theory (TDDFT). The topmost tier of parallelism relies on a distributed memory framework, in which we build an exciton model that couples chromophoric units. Combining these multiple levels of parallelism allows access to ground and excited state dynamics for large multichromophoric assemblies. The parallel excitonic framework is in good agreement with much more computationally demanding TDDFT calculations of the full assembly. PMID:25186064

  7. Optimization of the accelerated curing process of concrete using a fibre Bragg grating-based control system and microwave technology

    NASA Astrophysics Data System (ADS)

    Fabian, Matthias; Jia, Yaodong; Shi, Shi; McCague, Colum; Bai, Yun; Sun, Tong; Grattan, Kenneth T. V.

    2016-05-01

    In this paper, an investigation into the suitability of using fibre Bragg gratings (FBGs) for monitoring the accelerated curing process of concrete in a microwave heating environment is presented. In this approach, the temperature data provided by the FBGs are used to regulate automatically the microwave power so that a pre-defined temperature profile is maintained to optimize the curing process, achieving early strength values comparable to those of conventional heat-curing techniques but with significantly reduced energy consumption. The immunity of the FBGs to interference from the microwave radiation used ensures stable readings in the targeted environment, unlike conventional electronic sensor probes.

  8. Molecular Mechanisms and Evolutionary Processes Contributing to Accelerated Divergence of Gene Expression on the Drosophila X Chromosome.

    PubMed

    Coolon, Joseph D; Stevenson, Kraig R; McManus, C Joel; Yang, Bing; Graveley, Brenton R; Wittkopp, Patricia J

    2015-10-01

    In species with a heterogametic sex, population genetics theory predicts that DNA sequences on the X chromosome can evolve faster than comparable sequences on autosomes. Both neutral and nonneutral evolutionary processes can generate this pattern. Complex traits like gene expression are not predicted to have accelerated evolution by these theories, yet a "faster-X" pattern of gene expression divergence has recently been reported for both Drosophila and mammals. Here, we test the hypothesis that accelerated adaptive evolution of cis-regulatory sequences on the X chromosome is responsible for this pattern by comparing the relative contributions of cis- and trans-regulatory changes to patterns of faster-X expression divergence observed between strains and species of Drosophila with a range of divergence times. We find support for this hypothesis, especially among male-biased genes, when comparing different species. However, we also find evidence that trans-regulatory differences contribute to a faster-X pattern of expression divergence both within and between species. This contribution is surprising because trans-acting regulators of X-linked genes are generally assumed to be randomly distributed throughout the genome. We found, however, that X-linked transcription factors appear to preferentially regulate expression of X-linked genes, providing a potential mechanistic explanation for this result. The contribution of trans-regulatory variation to faster-X expression divergence was larger within than between species, suggesting that it is more likely to result from neutral processes than positive selection. These data show how accelerated evolution of both coding and noncoding sequences on the X chromosome can lead to accelerated expression divergence on the X chromosome relative to autosomes.

  9. Molecular Mechanisms and Evolutionary Processes Contributing to Accelerated Divergence of Gene Expression on the Drosophila X Chromosome

    PubMed Central

    Coolon, Joseph D.; Stevenson, Kraig R.; McManus, C. Joel; Yang, Bing; Graveley, Brenton R.; Wittkopp, Patricia J.

    2015-01-01

    In species with a heterogametic sex, population genetics theory predicts that DNA sequences on the X chromosome can evolve faster than comparable sequences on autosomes. Both neutral and nonneutral evolutionary processes can generate this pattern. Complex traits like gene expression are not predicted to have accelerated evolution by these theories, yet a “faster-X” pattern of gene expression divergence has recently been reported for both Drosophila and mammals. Here, we test the hypothesis that accelerated adaptive evolution of cis-regulatory sequences on the X chromosome is responsible for this pattern by comparing the relative contributions of cis- and trans-regulatory changes to patterns of faster-X expression divergence observed between strains and species of Drosophila with a range of divergence times. We find support for this hypothesis, especially among male-biased genes, when comparing different species. However, we also find evidence that trans-regulatory differences contribute to a faster-X pattern of expression divergence both within and between species. This contribution is surprising because trans-acting regulators of X-linked genes are generally assumed to be randomly distributed throughout the genome. We found, however, that X-linked transcription factors appear to preferentially regulate expression of X-linked genes, providing a potential mechanistic explanation for this result. The contribution of trans-regulatory variation to faster-X expression divergence was larger within than between species, suggesting that it is more likely to result from neutral processes than positive selection. These data show how accelerated evolution of both coding and noncoding sequences on the X chromosome can lead to accelerated expression divergence on the X chromosome relative to autosomes. PMID:26041937

  10. Accelerating the commercialization of university technologies for military healthcare applications: the role of the proof of concept process

    NASA Astrophysics Data System (ADS)

    Ochoa, Rosibel; DeLong, Hal; Kenyon, Jessica; Wilson, Eli

    2011-06-01

    The von Liebig Center for Entrepreneurism and Technology Advancement at UC San Diego (vonliebig.ucsd.edu) is focused on accelerating technology transfer and commercialization through programs and education on entrepreneurism. Technology Acceleration Projects (TAPs) that offer pre-venture grants and extensive mentoring on technology commercialization are a key component of its model which has been developed over the past ten years with the support of a grant from the von Liebig Foundation. In 2010, the von Liebig Entrepreneurism Center partnered with the U.S. Army Telemedicine and Advanced Technology Research Center (TATRC), to develop a regional model of Technology Acceleration Program initially focused on military research to be deployed across the nation to increase awareness of military medical needs and to accelerate the commercialization of novel technologies to treat the patient. Participants to these challenges are multi-disciplinary teams of graduate students and faculty in engineering, medicine and business representing universities and research institutes in a region, selected via a competitive process, who receive commercialization assistance and funding grants to support translation of their research discoveries into products or services. To validate this model, a pilot program focused on commercialization of wireless healthcare technologies targeting campuses in Southern California has been conducted with the additional support of Qualcomm, Inc. Three projects representing three different universities in Southern California were selected out of forty five applications from ten different universities and research institutes. Over the next twelve months, these teams will conduct proof of concept studies, technology development and preliminary market research to determine the commercial feasibility of their technologies. This first regional program will help build the needed tools and processes to adapt and replicate this model across other regions in the

  11. Neutron activation processes simulation in an Elekta medical linear accelerator head.

    PubMed

    Juste, B; Miró, R; Verdú, G; Díez, S; Campayo, J M

    2014-01-01

    Monte Carlo estimation of the giant-dipole-resonance (GRN) photoneutrons inside the Elekta Precise LINAC head (emitting a 15 MV photon beam) were performed using the MCNP6 (general-purpose Monte Carlo N-Particle code, version 6). Each component of LINAC head geometry and materials were modelled in detail using the given manufacturer information. Primary photons generate photoneutrons and its transport across the treatment head was simulated, including the (n, γ) reactions which undergo activation products. The MCNP6 was used to develop a method for quantifying the activation of accelerator components. The approach described in this paper is useful in quantifying the origin and the amount of nuclear activation.

  12. Laser Processing on the Surface of Niobium Superconducting Radio-Frequency Accelerator Cavities

    NASA Astrophysics Data System (ADS)

    Singaravelu, Senthilraja; Klopf, Michael; Krafft, Geoffrey; Kelley, Michael

    2011-03-01

    Superconducting Radio frequency (SRF) niobium cavities are at the heart of an increasing number of particle accelerators.~ Their performance is dominated by a several nm thick layer at the interior surface. ~Maximizing its smoothness is found to be critical and aggressive chemical treatments are employed to this end.~ We describe laser-induced surface melting as an alternative ``greener'' approach.~ Modeling guided selection of parameters for irradiation with a Q-switched Nd:YAG laser.~ The resulting topography was examined by SEM, AFM and Stylus Profilometry.

  13. A review of advanced small-scale parallel bioreactor technology for accelerated process development: current state and future need.

    PubMed

    Bareither, Rachel; Pollard, David

    2011-01-01

    The pharmaceutical and biotech industries face continued pressure to reduce development costs and accelerate process development. This challenge occurs alongside the need for increased upstream experimentation to support quality by design initiatives and the pursuit of predictive models from systems biology. A small scale system enabling multiple reactions in parallel (n ≥ 20), with automated sampling and integrated to purification, would provide significant improvement (four to fivefold) to development timelines. State of the art attempts to pursue high throughput process development include shake flasks, microfluidic reactors, microtiter plates and small-scale stirred reactors. The limitations of these systems are compared to desired criteria to mimic large scale commercial processes. The comparison shows that significant technological improvement is still required to provide automated solutions that can speed upstream process development.

  14. Revascularization in atherosclerotic renovascular disease: problems beyond the obstruction.

    PubMed

    Chade, A R

    2006-09-01

    The main goal in the treatment of obstructive atherosclerotic renovascular disease (ARVD) is to preserve or recover renal function. The ARVD kidney continues to deteriorate in 20-40% of cases despite restoration of blood flow. Holden et al. report that renal function stabilized or improved in up to 97% of patients with the use of a distal embolic protection device. PMID:16929332

  15. Atherosclerotic changes of vessels caused by restriction of movement

    NASA Technical Reports Server (NTRS)

    Gvishiani, G. S.; Kobakhidze, N. G.; Mchedlishvili, M. G.; Dekanosidze, T. I.

    1980-01-01

    The effect of restriction of movement on the development of atheroscelerosis was studied in rabbits. Drastic restriction of movement for 20 and 30 days causes atherosclerotic alterations of the aorta and shifts in ECG which are characteristic of coronary atherosclerosis. At the same time, shortening of the duration of blood coagulation and an increase in the content of catecholamines and beta-lipoproteids occur.

  16. Cap buckling as a potential mechanism of atherosclerotic plaque vulnerability.

    PubMed

    Abdelali, Maria; Reiter, Steven; Mongrain, Rosaire; Bertrand, Michel; L'Allier, Philippe L; Kritikou, Ekaterini A; Tardif, Jean-Claude

    2014-04-01

    Plaque rupture in atherosclerosis is the primary cause of potentially deadly coronary events, yet about 40% of ruptures occur away from the plaque cap shoulders and cannot be fully explained with the current biomechanical theories. Here, cap buckling is considered as a potential destabilizing factor which increases the propensity of the atherosclerotic plaque to rupture and which may also explain plaque failure away from the cap shoulders. To investigate this phenomenon, quasistatic 2D finite element simulations are performed, considering the salient geometrical and nonlinear material properties of diverse atherosclerotic plaques over the range of physiological loads. The numerical results indicate that buckling may displace the location of the peak von Mises stresses in the deflected caps. Plaque buckling, together with its deleterious effects is further observed experimentally in plaque caps using a physical model of deformable mock coronary arteries with fibroatheroma. Moreover, an analytical approach combining quasistatic equilibrium equations with the Navier-Bresse formulas is used to demonstrate the buckling potential of a simplified arched slender cap under intraluminal pressure and supported by foundations. This analysis shows that plaque caps - calcified, fibrotic or cellular - may buckle in specific undulated shapes once submitted to critical loads. Finally, a preliminary analysis of intravascular ultrasonography recordings of patients with atherosclerotic coronary arteries corroborates the numerical, experimental and theoretical findings and shows that various plaque caps buckle in vivo. By displacing the sites of high stresses in the plaque cap, buckling may explain the atherosclerotic plaque cap rupture at various locations, including cap shoulders.

  17. In vivo determination of arterial collagen synthesis in atherosclerotic rabbits

    SciTech Connect

    Opsahl, W.P.; DeLuca, D.J.; Ehrhart, L.A.

    1986-03-01

    Collagen and non-collagen protein synthesis rates were determined in vivo in tissues from rabbits fed a control or atherogenic diet supplemented with 2% peanut oil and 0.25% cholesterol for 4 months. Rabbits received a bolus intravenous injection of L-(/sup 3/H)-proline (1.0 mCi/kg) and unlabeled L-proline (7 mmoles/kg) in 0.9% NaCl. Plasma proline specific activity decreased only 20% over 5 hr and was similar to the specific activity of free proline in tissues. Thoracic aortas from atherosclerotic rabbits exhibited raised plaques covering at least 75% of the surface. Thoracic intima plus a portion of the media (TIM) was separated from the remaining media plus adventitia (TMA). Dry delipidated weight, total collagen content, and collagen as a percent of dry weight were increased significantly in the TIM of atherosclerotic rabbits. Collagen synthesis rates and collagen synthesis as a percent of total protein synthesis were likewise increased both in the TIM and in the abdominal aortas. No differences from controls either in collagen content or collagen synthesis rates were observed in the TMA, lung or skin. These results demonstrate for the first time in vivo that formation of atherosclerotic plaques is associated with increased rates of collagen synthesis. Furthermore, as previously observed with incubations in vitro, collagen synthesis was elevated to a greater extent than noncollagen protein synthesis in atherosclerotic aortas from rabbits fed cholesterol plus peanut oil.

  18. [Changes in proinflammatory cytokine and destructive metalloproteinase levels during formation of unstable atherosclerotic plaque].

    PubMed

    Ragino, Iu I; Cherniavskiĭ, A M; Polonskaia, Ia V; Volkov, A M; Semaeva, E V; Tsymbal, S Iu; Voevoda, M I

    2009-01-01

    We studied men with coronary atherosclerosis without acute coronary syndrome and determined typical valuable parameters of inflammatory (tumor necrotic factor, antagonist of receptor to interleukin [IL] 1, IL 6, IL 8, monocytes chemotactic protein 1, endothelial monocytes activating protein II), and destructive (matrix metalloproteinase [MMP] 3, MMP 7, MMP 9, tissue inhibitor of metalloproteinase) processes at consecutive stages of formation of coronary atherosclerotic plaque: "normal intimal tissue --> lipid stain --> early stable plaque --> unstable vulnerable plaque <--> stable plaque with fibrosis", and in 3 types of unstable plaques (lipid type, inflammatory erosive type, necrotic type). PMID:19656094

  19. Improved laser damage threshold performance of calcium fluoride optical surfaces via Accelerated Neutral Atom Beam (ANAB) processing

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, S.; Walsh, M.; Svrluga, R.; Thomas, M.

    2015-11-01

    Optics are not keeping up with the pace of laser advancements. The laser industry is rapidly increasing its power capabilities and reducing wavelengths which have exposed the optics as a weak link in lifetime failures for these advanced systems. Nanometer sized surface defects (scratches, pits, bumps and residual particles) on the surface of optics are a significant limiting factor to high end performance. Angstrom level smoothing of materials such as calcium fluoride, spinel, magnesium fluoride, zinc sulfide, LBO and others presents a unique challenge for traditional polishing techniques. Exogenesis Corporation, using its new and proprietary Accelerated Neutral Atom Beam (ANAB) technology, is able to remove nano-scale surface damage and particle contamination leaving many material surfaces with roughness typically around one Angstrom. This surface defect mitigation via ANAB processing can be shown to increase performance properties of high intensity optical materials. This paper describes the ANAB technology and summarizes smoothing results for calcium fluoride laser windows. It further correlates laser damage threshold improvements with the smoothing produced by ANAB surface treatment. All ANAB processing was performed at Exogenesis Corporation using an nAccel100TM Accelerated Particle Beam processing tool. All surface measurement data for the paper was produced via AFM analysis on a Park Model XE70 AFM, and all laser damage testing was performed at Spica Technologies, Inc. Exogenesis Corporation's ANAB processing technology is a new and unique surface modification technique that has demonstrated to be highly effective at correcting nano-scale surface defects. ANAB is a non-contact vacuum process comprised of an intense beam of accelerated, electrically neutral gas atoms with average energies of a few tens of electron volts. The ANAB process does not apply mechanical forces associated with traditional polishing techniques. ANAB efficiently removes surface

  20. The dark and bright side of atherosclerotic calcification.

    PubMed

    Pugliese, Giuseppe; Iacobini, Carla; Blasetti Fantauzzi, Claudia; Menini, Stefano

    2015-02-01

    Vascular calcification is an unfavorable event in the natural history of atherosclerosis that predicts cardiovascular morbidity and mortality. However, increasing evidence suggests that different calcification patterns are associated with different or even opposite histopathological and clinical features, reflecting the dual relationship between inflammation and calcification. In fact, initial calcium deposition in response to pro-inflammatory stimuli results in the formation of spotty or granular calcification ("microcalcification"), which induces further inflammation. This vicious cycle favors plaque rupture, unless an adaptive response prevails, with blunting of inflammation and survival of vascular smooth muscle cells (VSMCs). VSMCs promote fibrosis and also undergo osteogenic transdifferentiation, with formation of homogeneous or sheet-like calcification ("macrocalcification"), that stabilizes the plaque by serving as a barrier towards inflammation. Unfortunately, little is known about the molecular mechanisms regulating this adaptive response. The advanced glycation/lipoxidation endproducts (AGEs/ALEs) have been shown to promote vascular calcification and atherosclerosis. Recent evidence suggests that two AGE/ALE receptors, RAGE and galectin-3, modulate in divergent ways, not only inflammation, but also vascular osteogenesis, by favoring "microcalcification" and "macrocalcification", respectively. Galectin-3 seems essential for VSMC transdifferentiation into osteoblast-like cells via direct modulation of the WNT-β-catenin signaling, thus driving formation of "macrocalcification", whereas RAGE favors deposition of "microcalcification" by promoting and perpetuating inflammation and by counteracting the osteoblastogenic effect of galectin-3. Further studies are required to understand the molecular mechanisms regulating transition from "microcalcification" to "macrocalcification", thus allowing to design therapeutic strategies which favor this adaptive process

  1. Acceleration{endash}deceleration process of thin foils confined in water and submitted to laser driven shocks

    SciTech Connect

    Romain, J.P.; Auroux, E.

    1997-08-01

    An experimental, numerical, and analytical study of the acceleration and deceleration process of thin metallic foils immersed in water and submitted to laser driven shocks is presented. Aluminum and copper foils of 20 to 120 {mu}m thickness, confined on both sides by water, have been irradiated at 1.06 {mu}m wavelength by laser pulses of {approximately}20ns duration, {approximately}17J energy, and {approximately}4GW/cm{sup 2} incident intensity. Time resolved velocity measurements have been made, using an electromagnetic velocity gauge. The recorded velocity profiles reveal an acceleration{endash}deceleration process, with a peak velocity up to 650 m/s. Predicted profiles from numerical simulations reproduce all experimental features, such as wave reverberations, rate of increase and decrease of velocity, peak velocity, effects of nature, and thickness of the foils. A shock pressure of about 2.5 GPa is inferred from the velocity measurements. Experimental points on the evolution of plasma pressure are derived from the measurements of peak velocities. An analytical description of the acceleration{endash}deceleration process, involving multiple shock and release waves reflecting on both sides of the foils, is presented. The space{endash}time diagrams of waves propagation and the successive pressure{endash}particle velocity states are determined, from which theoretical velocity profiles are constructed. All characteristics of experimental records and numerical simulations are well reproduced. The role of foil nature and thickness, in relation with the shock impedance of the materials, appears explicitly. {copyright} {ital 1997 American Institute of Physics.}

  2. Electrochemical Impedance Spectroscopy to Characterize Inflammatory Atherosclerotic Plaques

    PubMed Central

    Yu, Fei; Dai, Xiaohu; Beebe, Tyler; Hsiai, Tzung

    2011-01-01

    Despite advances in diagnosis and therapy, atherosclerotic cardiovascular disease remains the leading cause of morbidity and mortality in the Western world. Predicting metabolically active atherosclerotic lesions has remained an unmet clinical need. We hereby developed an electrochemical strategy to characterize the inflammatory states of high-risk atherosclerotic plaques. Using the concentric bipolar microelectrodes, we sought to demonstrate distinct Electrochemical Impedance Spectroscopic (EIS) measurements for unstable atherosclerotic plaques that harbored active lipids and inflammatory cells. Using equivalent circuits to simulate vessel impedance at the electrode-endoluminal tissue interface, we demonstrated specific electric elements to model working and counter electrode interfaces as well as the tissue impedance. Using explants of human coronary, carotid, and femoral arteries at various Stary stages of atherosclerotic lesions (n = 15), we performed endoluminal EIS measurements (n = 147) and validated with histology and immunohistochemistry. We computed the vascular tissue resistance using the equivalent circuit model and normalized the resistance to the lesion-free regions. Tissue resistance was significantly elevated in the oxLDL-rich thin-cap atheromas (1.57±0.40, n = 14, p < 0.001) and fatty streaks (1.36±0.28, n = 33, p < 0.001) as compared with lesion-free region (1.00±0.18, n = 82) or oxLDL-absent fibrous atheromas (0.86±0.30, n = 12). Tissue resistance was also elevated in the calcified core of fibrous atheroma (2.37±0.60, n = 6, p < 0.001). Despite presence of fibrous structures, tissue resistance between ox-LDL-absent fibroatheroma and the lesion-free regions was statistically insignificant (0.86±0.30, n = 12, p > 0.05). Hence, we demonstrate that the application of EIS strategy was sensitive to detect fibrous cap oxLDL-rich lesions and specific to distinguish oxLDL-absent fibroatheroma. PMID:21959227

  3. Impact absorption of four processed soft denture liners as influenced by accelerated aging.

    PubMed

    Kawano, F; Koran, A; Nuryanti, A; Inoue, S

    1997-01-01

    The cushioning effect of soft denture liners was evaluated by using a free drop test with an accelerometer. Materials tested included SuperSoft (Coe Laboratories, Chicago, IL), Kurepeet-Dough (Kreha Chemical, Tokyo), Molteno Soft (Molten, Hiroshima, Japan), and Molloplast-B (Molloplast Regneri, Karlsruhe, Germany). All materials were found to reduce the impact force when compared to acrylic denture base resin. A 2.4-mm layer of soft denture material demonstrated good impact absorption, and Molloplast-B and Molteno had excellent impact absorption. When the soft denture liner was kept in an accelerated aging chamber for 900 hours, the damping effect recorded increased for all materials tested. Aging of all materials also affected the cushioning effect.

  4. Studies of $${\\rm Nb}_{3}{\\rm Sn}$$ Strands Based on the Restacked-Rod Process for High Field Accelerator Magnets

    DOE PAGES

    Barzi, E.; Bossert, M.; Gallo, G.; Lombardo, V.; Turrioni, D.; Yamada, R.; Zlobin, A. V.

    2011-12-21

    A major thrust in Fermilab's accelerator magnet R&D program is the development of Nb3Sn wires which meet target requirements for high field magnets, such as high critical current density, low effective filament size, and the capability to withstand the cabling process. The performance of a number of strands with 150/169 restack design produced by Oxford Superconducting Technology was studied for round and deformed wires. To optimize the maximum plastic strain, finite element modeling was also used as an aid in the design. Results of mechanical, transport and metallographic analyses are presented for round and deformed wires.

  5. Young coconut juice can accelerate the healing process of cutaneous wounds

    PubMed Central

    2012-01-01

    Background Estrogen has been reported to accelerate cutaneous wound healing. This research studies the effect of young coconut juice (YCJ), presumably containing estrogen-like substances, on cutaneous wound healing in ovairectomized rats. Methods Four groups of female rats (6 in each group) were included in this study. These included sham-operated, ovariectomized (ovx), ovx receiving estradiol benzoate (EB) injections intraperitoneally, and ovx receiving YCJ orally. Two equidistant 1-cm full-thickness skin incisional wounds were made two weeks after ovariectomy. The rats were sacrificed at the end of the third and the fourth week of the study, and their serum estradiol (E2) level was measured by chemiluminescent immunoassay. The skin was excised and examined in histological sections stained with H&E, and immunostained using anti-estrogen receptor (ER-α an ER-β) antibodies. Results Wound healing was accelerated in ovx rats receiving YCJ, as compared to controls. This was associated with significantly higher density of immunostaining for ER-α an ER-β in keratinocytes, fibroblasts, white blood cells, fat cells, sebaceous gland, skeletal muscles, and hair shafts and follicles. This was also associated with thicker epidermis and dermis, but with thinner hypodermis. In addition, the number and size of immunoreactive hair follicles for both ER-α and ER-β were the highest in the ovx+YCJ group, as compared to the ovx+EB group. Conclusions This study demonstrates that YCJ has estrogen-like characteristics, which in turn seem to have beneficial effects on cutaneous wound healing. PMID:23234369

  6. Real-time dual-mode standard/complex Fourier-domain OCT system using graphics processing unit accelerated 4D signal processing and visualization

    NASA Astrophysics Data System (ADS)

    Zhang, Kang; Kang, Jin U.

    2011-03-01

    We realized a real-time dual-mode standard/complex Fourier-domain optical coherence tomography (FD-OCT) system using graphics processing unit (GPU) accelerated 4D (3D+time) signal processing and visualization. For both standard and complex FD-OCT modes, the signal processing tasks were implemented on a dual-GPUs architecture that included λ-to-k spectral re-sampling, fast Fourier transform (FFT), modified Hilbert transform, logarithmic-scaling, and volume rendering. The maximum A-scan processing speeds achieved are >3,000,000 line/s for the standard 1024-pixel-FD-OCT, and >500,000 line/s for the complex 1024-pixel-FD-OCT. Multiple volumerendering of the same 3D data set were preformed and displayed with different view angles. The GPU-acceleration technique is highly cost-effective and can be easily integrated into most ultrahigh speed FD-OCT systems to overcome the 3D data processing and visualization bottlenecks.

  7. Insulin inhibits inflammation and promotes atherosclerotic plaque stability via PI3K-Akt pathway activation.

    PubMed

    Yan, Hao; Ma, Ying; Li, Yan; Zheng, Xiaohui; Lv, Ping; Zhang, Yuan; Li, Jia; Ma, Meijuan; Zhang, Le; Li, Congye; Zhang, Rongqing; Gao, Feng; Wang, Haichang; Tao, Ling

    2016-02-01

    Toll-like receptor (TLR) 4 induced inflammation was reported to play an important role in atherosclerotic plaque stability. Recent studies indicated that insulin could inhibit inflammation by activating phosphatidylinositol 3-kinase-Akt-dependent (PI3K-Akt) signaling pathway. In the current study, we hypothesized that insulin would inhibit TLR4 induced inflammation via promoting PI3K-Akt activation, thus enhancing the stabilization of atherosclerotic plaques. In order to mimic the process of plaque formation, monocyte-macrophage lineage RAW264.7 were cultured and induced to form foam cells by oxidized LDL (ox-LDL). Oil red O staining results showed that insulin significantly restrained ox-LDL-induced foam cell formation. Analysis of inflammatory reaction during foam cell formation indicated that insulin significantly down-regulated the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6 levels, inhibited TLR4, myeloid differentiation primary response gene (MyD) 88 and nuclear factor (NF)-κB. Further mechanism analysis showed that pretreating with the PI3K blocker, wortmannin dramatically dampened the insulin-induced up-regulation of pAkt expression. Additionally, blockade of PI3K-Akt signaling also dampened the immunosuppression effect brought by insulin. Following the construction of a rodent atherosclerosis model, pretreatment of insulin resulted in an evident decrease in lipid deposition of the blood vessel wall, serum levels of TNF-α and IL-6, and numbers of infiltrated macrophages and foam cells. Taken together, these results suggested that insulin might inhibit inflammation and promote atherosclerotic plaque stability via the PI3K-Akt pathway by targeting TLR4-MyD88-NF-κB signaling. Our findings may provide a potential target for the prevention of cardiovascular disease. PMID:26681144

  8. Application of Low Level, Uniform Ultrasound Field for Acceleration of Enzymatic Bio-processing of Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzymatic bio-processing of cotton generates significantly less hazardous wastewater effluents, which are readily biodegradable, but it also has several critical shortcomings that impede its acceptance by industries: expensive processing costs and slow reaction rates. Our research has found that th...

  9. Implications of acceleration environments on scaling materials processing in space to production

    NASA Technical Reports Server (NTRS)

    Demel, Ken

    1990-01-01

    Some considerations regarding materials processing in space are covered from a commercial perspective. Key areas include power, proprietary data, operational requirements (including logistics), and also the center of gravity location, and control of that location with respect to materials processing payloads.

  10. Topographic power spectral density study of the effect of surface treatment processes on niobium for superconducting radio frequency accelerator cavities

    SciTech Connect

    Charles Reece, Hui Tian, Michael Kelley, Chen Xu

    2012-04-01

    Microroughness is viewed as a critical issue for attaining optimum performance of superconducting radio frequency accelerator cavities. The principal surface smoothing methods are buffered chemical polish (BCP) and electropolish (EP). The resulting topography is characterized by atomic force microscopy (AFM). The power spectral density (PSD) of AFM data provides a more thorough description of the topography than a single-value roughness measurement. In this work, one dimensional average PSD functions derived from topography of BCP and EP with different controlled starting conditions and durations have been fitted with a combination of power law, K correlation, and shifted Gaussian models to extract characteristic parameters at different spatial harmonic scales. While the simplest characterizations of these data are not new, the systematic tracking of scale-specific roughness as a function of processing is new and offers feedback for tighter process prescriptions more knowledgably targeted at beneficial niobium topography for superconducting radio frequency applications.

  11. Effects of accelerated reading rate on processing words' syntactic functions by normal and dyslexic readers: event related potentials evidence.

    PubMed

    Breznitz, Z; Leikin, M

    2001-09-01

    In the present study, the authors examined differences in brain activity, as measured by amplitudes and latencies of event related potentials (ERP) components, in Hebrew-speaking adult dyslexic and normal readers when processing sentence components with different grammatical functions. Participants were 20 dyslexic and 20 normally reading male college students aged 18-27 years. The authors examined the processing of normal word strings in word-by-word reading of sentences having subject-verb-object (SVO) syntactic structure in self- and fast-paced conditions. Data revealed that in both reading conditions, the N100 and P300 ERP components were sensitive to internal processes such as recognition of words' grammatical functions. However, the results revealed that fast-paced reading rate might affect this process, as was reflected in the systematic changes of amplitudes and latencies of both ERP components. In accelerated reading, a significant decrease of latencies and increase of amplitudes in dyslexics were shown. It was also found that influence of fast-paced reading rate was realized in the full usage of the word-order strategy in sentence processing. In turn, this fact confirmed the hypothesis concerning a syntactic processing "weakness" in dyslexia.

  12. Accelerating solidification process simulation for large-sized system of liquid metal atoms using GPU with CUDA

    NASA Astrophysics Data System (ADS)

    Jie, Liang; Li, KenLi; Shi, Lin; Liu, RangSu; Mei, Jing

    2014-01-01

    Molecular dynamics simulation is a powerful tool to simulate and analyze complex physical processes and phenomena at atomic characteristic for predicting the natural time-evolution of a system of atoms. Precise simulation of physical processes has strong requirements both in the simulation size and computing timescale. Therefore, finding available computing resources is crucial to accelerate computation. However, a tremendous computational resource (GPGPU) are recently being utilized for general purpose computing due to its high performance of floating-point arithmetic operation, wide memory bandwidth and enhanced programmability. As for the most time-consuming component in MD simulation calculation during the case of studying liquid metal solidification processes, this paper presents a fine-grained spatial decomposition method to accelerate the computation of update of neighbor lists and interaction force calculation by take advantage of modern graphics processors units (GPU), enlarging the scale of the simulation system to a simulation system involving 10 000 000 atoms. In addition, a number of evaluations and tests, ranging from executions on different precision enabled-CUDA versions, over various types of GPU (NVIDIA 480GTX, 580GTX and M2050) to CPU clusters with different number of CPU cores are discussed. The experimental results demonstrate that GPU-based calculations are typically 9∼11 times faster than the corresponding sequential execution and approximately 1.5∼2 times faster than 16 CPU cores clusters implementations. On the basis of the simulated results, the comparisons between the theoretical results and the experimental ones are executed, and the good agreement between the two and more complete and larger cluster structures in the actual macroscopic materials are observed. Moreover, different nucleation and evolution mechanism of nano-clusters and nano-crystals formed in the processes of metal solidification is observed with large-sized system.

  13. Accelerating solidification process simulation for large-sized system of liquid metal atoms using GPU with CUDA

    SciTech Connect

    Jie, Liang; Li, KenLi; Shi, Lin; Liu, RangSu; Mei, Jing

    2014-01-15

    Molecular dynamics simulation is a powerful tool to simulate and analyze complex physical processes and phenomena at atomic characteristic for predicting the natural time-evolution of a system of atoms. Precise simulation of physical processes has strong requirements both in the simulation size and computing timescale. Therefore, finding available computing resources is crucial to accelerate computation. However, a tremendous computational resource (GPGPU) are recently being utilized for general purpose computing due to its high performance of floating-point arithmetic operation, wide memory bandwidth and enhanced programmability. As for the most time-consuming component in MD simulation calculation during the case of studying liquid metal solidification processes, this paper presents a fine-grained spatial decomposition method to accelerate the computation of update of neighbor lists and interaction force calculation by take advantage of modern graphics processors units (GPU), enlarging the scale of the simulation system to a simulation system involving 10 000 000 atoms. In addition, a number of evaluations and tests, ranging from executions on different precision enabled-CUDA versions, over various types of GPU (NVIDIA 480GTX, 580GTX and M2050) to CPU clusters with different number of CPU cores are discussed. The experimental results demonstrate that GPU-based calculations are typically 9∼11 times faster than the corresponding sequential execution and approximately 1.5∼2 times faster than 16 CPU cores clusters implementations. On the basis of the simulated results, the comparisons between the theoretical results and the experimental ones are executed, and the good agreement between the two and more complete and larger cluster structures in the actual macroscopic materials are observed. Moreover, different nucleation and evolution mechanism of nano-clusters and nano-crystals formed in the processes of metal solidification is observed with large

  14. Brightest Fermi-LAT flares of PKS 1222+216: implications on emission and acceleration processes

    SciTech Connect

    Kushwaha, Pankaj; Singh, K. P.; Sahayanathan, Sunder

    2014-11-20

    We present a high time resolution study of the two brightest γ-ray outbursts from a blazar PKS 1222+216 observed by the Fermi Large Area Telescope (LAT) in 2010. The γ-ray light curves obtained in four different energy bands, 0.1-3, 0.1-0.3, 0.3-1, and 1-3 GeV, with time bins of six hours, show asymmetric profiles with similar rise times in all the bands but a rapid decline during the April flare and a gradual one during the June flare. The light curves during the April flare show an ∼2 day long plateau in 0.1-0.3 GeV emission, erratic variations in 0.3-1 GeV emission, and a daily recurring feature in 1-3 GeV emission until the rapid rise and decline within a day. The June flare shows a monotonic rise until the peak, followed by a gradual decline powered mainly by the multi-peak 0.1-0.3 GeV emission. The peak fluxes during both the flares are similar except in the 1-3 GeV band in April, which is twice the corresponding flux during the June flare. Hardness ratios during the April flare indicate spectral hardening in the rising phase followed by softening during the decay. We attribute this behavior to the development of a shock associated with an increase in acceleration efficiency followed by its decay leading to spectral softening. The June flare suggests hardening during the rise followed by a complicated energy dependent behavior during the decay. Observed features during the June flare favor multiple emission regions while the overall flaring episode can be related to jet dynamics.

  15. Hardware acceleration of lucky-region fusion (LRF) algorithm for image acquisition and processing

    NASA Astrophysics Data System (ADS)

    Maignan, William; Koeplinger, David; Carhart, Gary W.; Aubailly, Mathieu; Kiamilev, Fouad; Liu, J. Jiang

    2013-05-01

    "Lucky-region fusion" (LRF) is an image processing technique that has proven successful in enhancing the quality of images distorted by atmospheric turbulence. The LRF algorithm extracts sharp regions of an image obtained from a series of short exposure frames, and "fuses" them into a final image with improved quality. In previous research, the LRF algorithm had been implemented on a PC using a compiled programming language. However, the PC usually does not have sufficient processing power to handle real-time extraction, processing and reduction required when the LRF algorithm is applied not to single picture images but rather to real-time video from fast, high-resolution image sensors. This paper describes a hardware implementation of the LRF algorithm on a Virtex 6 field programmable gate array (FPGA) to achieve real-time video processing. The novelty in our approach is the creation of a "black box" LRF video processing system with a standard camera link input, a user controller interface, and a standard camera link output.

  16. [The clinico-instrumental characteristics of the lesions of the precerebral arteries in patients with atherosclerotic circulatory encephalopathy].

    PubMed

    Hryhorash, H A; Rudenko, A Iu; Lushchyk, U B; Al'tman, I V

    1994-01-01

    Results have been analysed of comprehensive evaluation of 175 patients with discirculatory encephalopathy of atherosclerotic genesis, consisting of inspection of the neck vessels projection, study of neurological status, ultrasonic investigation of the major brain arteries structure and hemodynamics, their angiographic features. At stage I discirculatory encephalopathy subjective complaints predominated, being caused by syndrome of thoracic outlet, steal syndrome, stenosing lesions of brachiocephalic arteries. Encountered more frequently in the middle-aged and elderly patients were affections of several major brain arteries. Specific weight of correlation between ultrasonic investigation and angiography in stenosing lesions of brachiocephalic arteries in patients with discirculatory encephalopathy constituted 84-100%. Therefore patients with discirculatory encephalopathy of atherosclerotic genesis require ultrasonic investigation of brachiocephalic arteries with the purpose of finding out exactly the pathological process and choosing the tactics of treatment.

  17. Systemic Atherosclerotic Inflammation Following Acute Myocardial Infarction: Myocardial Infarction Begets Myocardial Infarction

    PubMed Central

    Joshi, Nikhil V; Toor, Iqbal; Shah, Anoop S V; Carruthers, Kathryn; Vesey, Alex T; Alam, Shirjel R; Sills, Andrew; Hoo, Teng Y; Melville, Adam J; Langlands, Sarah P; Jenkins, William S A; Uren, Neal G; Mills, Nicholas L; Fletcher, Alison M; van Beek, Edwin J R; Rudd, James H F; Fox, Keith A A; Dweck, Marc R; Newby, David E

    2015-01-01

    Background Preclinical data suggest that an acute inflammatory response following myocardial infarction (MI) accelerates systemic atherosclerosis. Using combined positron emission and computed tomography, we investigated whether this phenomenon occurs in humans. Methods and Results Overall, 40 patients with MI and 40 with stable angina underwent thoracic 18F-fluorodeoxyglucose combined positron emission and computed tomography scan. Radiotracer uptake was measured in aortic atheroma and nonvascular tissue (paraspinal muscle). In 1003 patients enrolled in the Global Registry of Acute Coronary Events, we assessed whether infarct size predicted early (≤30 days) and late (>30 days) recurrent coronary events. Compared with patients with stable angina, patients with MI had higher aortic 18F-fluorodeoxyglucose uptake (tissue-to-background ratio 2.15±0.30 versus 1.84±0.18, P<0.0001) and plasma C-reactive protein concentrations (6.50 [2.00 to 12.75] versus 2.00 [0.50 to 4.00] mg/dL, P=0.0005) despite having similar aortic (P=0.12) and less coronary (P=0.006) atherosclerotic burden and similar paraspinal muscular 18F-fluorodeoxyglucose uptake (P=0.52). Patients with ST-segment elevation MI had larger infarcts (peak plasma troponin 32 300 [10 200 to >50 000] versus 3800 [1000 to 9200] ng/L, P<0.0001) and greater aortic 18F-fluorodeoxyglucose uptake (2.24±0.32 versus 2.02±0.21, P=0.03) than those with non–ST-segment elevation MI. Peak plasma troponin concentrations correlated with aortic 18F-fluorodeoxyglucose uptake (r=0.43, P=0.01) and, on multivariate analysis, independently predicted early (tertile 3 versus tertile 1: relative risk 4.40 [95% CI 1.90 to 10.19], P=0.001), but not late, recurrent MI. Conclusions The presence and extent of MI is associated with increased aortic atherosclerotic inflammation and early recurrent MI. This finding supports the hypothesis that acute MI exacerbates systemic atherosclerotic inflammation and remote plaque destabilization

  18. Endovascular Versus Medical Therapy for Atherosclerotic Renovascular Disease

    PubMed Central

    Yu, Mark Shipeng; Folt, David A.; Drummond, Christopher A.; Haller, Steven T.; Cooper, Emily L.; Brewster, Pamela; Evans, Kaleigh L.

    2016-01-01

    The diagnosis of renal artery stenosis (RAS) has become increasingly common in part due to greater awareness of ischemic renal disease and increased use of diagnostic techniques. Over 90 % of RAS cases are caused by atherosclerotic renovascular disease (ARVD). Patients with ARVD are at high risk for fatal and nonfatal cardiovascular and renal events. The mortality rate in patients with ARVD is high, especially with other cardiovascular or renal comorbidities. Recent clinical studies have provided substantial evidence concerning medical therapy and endovascular interventional therapeutic approaches for ARVD. Despite previous randomized clinical trials, the optimal therapy for ARVD remained uncertain until the results of the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial were released recently. CORAL demonstrated that optimal medical therapy was equally effective to endovascular therapy in the treatment of ARVD. Clinicians can now practice with more evidence-based medicine to treat ARVD and potentially decrease mortality in patients with ARVD using optimal medical therapy. PMID:25301353

  19. Intravascular photoacoustic tomography for characterization of atherosclerotic lipid and inflammation

    NASA Astrophysics Data System (ADS)

    Zhang, Jian; Qin, Huan; Shi, Yujiao; Yang, Sihua; Xing, Da

    2014-09-01

    Photoacoustic imaging is a fast growing imaging technology depending on its high optical resolution of optics while taking the advantage of the high penetration depth of ultrasound. In this paper, we demonstrate the new progress in the photoacoustic imaging. Atherosclerosis is characterized by a progressive build-up of lipid in the arterial wall, which is known as plaque. Histological studies demonstrate that the primary cause of acute cardiovascular events is the rupture of atherosclerotic plaques. Lipid and inflammation within the plaque are related to influence the propensity of plaques to disrupt. Photoacoustic intravascular tomography (IVPAT) holds a great advantage in providing comprehensive morphological and functional information of plaques. Lipid relative concentration maps of atherosclerotic aorta were obtained and compared with histology. Furthermore, by selectively targeting the intravascular inflammatory cytokines, IVPAT is also capable of mapping the inflamed area and determining the degree of inflammation.

  20. Monte Carlo-based fluorescence molecular tomography reconstruction method accelerated by a cluster of graphic processing units.

    PubMed

    Quan, Guotao; Gong, Hui; Deng, Yong; Fu, Jianwei; Luo, Qingming

    2011-02-01

    High-speed fluorescence molecular tomography (FMT) reconstruction for 3-D heterogeneous media is still one of the most challenging problems in diffusive optical fluorescence imaging. In this paper, we propose a fast FMT reconstruction method that is based on Monte Carlo (MC) simulation and accelerated by a cluster of graphics processing units (GPUs). Based on the Message Passing Interface standard, we modified the MC code for fast FMT reconstruction, and different Green's functions representing the flux distribution in media are calculated simultaneously by different GPUs in the cluster. A load-balancing method was also developed to increase the computational efficiency. By applying the Fréchet derivative, a Jacobian matrix is formed to reconstruct the distribution of the fluorochromes using the calculated Green's functions. Phantom experiments have shown that only 10 min are required to get reconstruction results with a cluster of 6 GPUs, rather than 6 h with a cluster of multiple dual opteron CPU nodes. Because of the advantages of high accuracy and suitability for 3-D heterogeneity media with refractive-index-unmatched boundaries from the MC simulation, the GPU cluster-accelerated method provides a reliable approach to high-speed reconstruction for FMT imaging.

  1. From Lipids to Inflammation: New Approaches to Reducing Atherosclerotic Risk.

    PubMed

    Shapiro, Michael D; Fazio, Sergio

    2016-02-19

    The introduction of statins ≈ 30 years ago ushered in the era of lipid lowering as the most effective way to reduce risk of atherosclerotic cardiovascular disease. Nonetheless, residual risk remains high, and statin intolerance is frequently encountered in clinical practice. After a long dry period, the field of therapeutics targeted to lipids and atherosclerosis has entered a renaissance. Moreover, the demonstration of clinical benefits from the addition of ezetimibe to statin therapy in subjects with acute coronary syndromes has renewed the enthusiasm for the cholesterol hypothesis and the hope that additional agents that lower low-density lipoprotein will decrease risk of atherosclerotic cardiovascular disease. Drugs in the orphan disease category are now available for patients with the most extreme hypercholesterolemia. Furthermore, discovery and rapid translation of a novel biological pathway has given rise to a new class of cholesterol-lowering drugs, the proprotein convertase subtilisin kexin-9 inhibitors. Trials of niacin added to statin have failed to demonstrate cardiac benefits, and 3 cholesterol ester transfer protein inhibitors have also failed to reduce atherosclerotic cardiovascular disease risk, despite producing substantial increases in HDL levels. Although the utility of triglyceride-lowering therapies remains uncertain, 2 large clinical trials are testing the influence of omega-3 polyunsaturated fatty acids on atherosclerotic events in hypertriglyceridemia. Novel antisense therapies targeting apolipoprotein C-III (for triglyceride reduction) and apo(a) (for lipoprotein(a) reduction) are showing a promising trajectory. Finally, 2 large clinical trials are formally putting the inflammatory hypothesis of atherosclerosis to the test and may open a new avenue for cardiovascular disease risk reduction.

  2. Macrophage-targeted photodynamic detection of vulnerable atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Hamblin, Michael R.; Tawakol, Ahmed; Castano, Ana P.; Gad, Faten; Zahra, Touqir; Ahmadi, Atosa; Stern, Jeremy; Ortel, Bernhard; Chirico, Stephanie; Shirazi, Azadeh; Syed, Sakeena; Muller, James E.

    2003-06-01

    Rupture of a vulnerable atherosclerotic plaque (VP) leading to coronary thrombosis is the chief cause of sudden cardiac death. VPs are angiographically insignificant lesions, which are excessively inflamed and characterized by dense macrophage infiltration, large necrotic lipid cores, thin fibrous caps, and paucity of smooth muscle cells. We have recently shown that chlorin(e6) conjugated with maleylated albumin can target macrophages with high selectivity via the scavenger receptor. We report the potential of this macrophage-targeted fluorescent probe to localize in VPs in a rabbit model of atherosclerosis, and allow detection and/or diagnosis by fluorescence spectroscopy or imaging. Atherosclerotic lesions were induced in New Zealand White rabbit aortas by balloon injury followed by administration of a high-fat diet. 24-hours after IV injection of the conjugate into atherosclerotic or normal rabbits, the animals were sacrificed, and aortas were removed, dissected and examined for fluorescence localization in plaques by fiber-based spectrofluorimetry and confocal microscopy. Dye uptake within the aortas was also quantified by fluorescence extraction of samples from aorta segments. Biodistribution of the dye was studied in many organs of the rabbits. Surface spectrofluorimetry after conjugate injection was able to distinguish between plaque and adjacent aorta, between atherosclerotic and normal aorta, and balloon-injured and normal iliac arteries with high significance. Discrete areas of high fluorescence (up to 20 times control were detected in the balloon-injured segments, presumably corresponding to macrophage-rich plaques. Confocal microscopy showed red ce6 fluorescence localized in plaques that showed abundant foam cells and macrophages by histology. Extraction data on aortic tissue corroborated the selectivity of the conjugate for plaques. These data support the strategy of employing macrophage-targeted fluorescent dyes to detect VP by intravascular

  3. NREL Develops Accelerated Sample Activation Process for Hydrogen Storage Materials (Fact Sheet)

    SciTech Connect

    Not Available

    2010-12-01

    This fact sheet describes NREL's accomplishments in developing a new sample activation process that reduces the time to prepare samples for measurement of hydrogen storage from several days to five minutes and provides more uniform samples. Work was performed by NREL's Chemical and Materials Science Center.

  4. Poor maternal nutrition programmes a pro-atherosclerotic phenotype in ApoE-/- mice.

    PubMed

    Blackmore, Heather L; Piekarz, Ana V; Fernandez-Twinn, Denise S; Mercer, John R; Figg, Nichola; Bennett, Martin; Ozanne, Susan E

    2012-08-01

    Numerous animal studies have consistently shown that early life exposure to LP (low-protein) diet programmes risk factors for CVD (cardiovascular disease) such as dyslipidaemia, high BP (blood pressure) and cardiac dysfunction in the offspring. However, studies on the effect of maternal under-nutrition on offspring development of atherosclerosis are scarce. Applying our LP model to the ApoE(-/-) atherosclerosis-prone mouse model, we investigated the development of atherosclerotic lesions in the aortic root of 6-month-old offspring. In addition, markers of plaque progression including SMA (smooth muscle actin) and Mac3 (macrophage marker 3) were studied. Pregnant dams were fed on a control (20% protein) or on an isocaloric LP diet (8% protein) throughout pregnancy and lactation. After weaning, male offspring were maintained on 20% normal laboratory chow. At 6 months of age, LP offspring showed a significantly greater plaque area (P<0.05) with increased cholesterol clefts and significantly higher indices of DNA damage compared with controls (P<0.05). The expression of HMG-CoA reductase (3-hydroxy-3-methyl-glutaryl-CoA reductase) (P<0.05) and LDL (low-density lipoprotein) receptor in the liver of LP offspring were increased. Furthermore, LP offspring had higher LDL-cholesterol levels (P<0.05) and a trend towards elevated insulin. There were no differences in other lipid measurements and fasting glucose between groups. These observations suggest that early exposure to an LP diet accelerates the development and increases the progression of atherosclerotic lesions in young adult offspring. Future studies are needed to elucidate the specific mechanisms linking in utero exposure to a diet low in protein to the development of atherosclerosis.

  5. Real-Time Elastography Visualization and Histopathological Characterization of Rabbit Atherosclerotic Carotid Arteries.

    PubMed

    Wang, ZhenZhen; Liu, NaNa; Zhang, LiFeng; Li, XiaoYing; Han, XueSong; Peng, YanQing; Dang, MeiZheng; Sun, LiTao; Tian, JiaWei

    2016-01-01

    To evaluate the feasibility of non-invasive vascular real-time elastography imaging (RTE) in visualizing the composition of rabbit carotid atherosclerotic plaque as determined by histopathology, a rabbit model of accelerated carotid atherosclerosis was used. Thirty rabbits were randomly divided into two groups of 15 rabbits each. The first group was fed a cholesterol-rich diet and received balloon-induced injury the left common carotid artery endothelium, whereas the second group only received a cholesterol-rich diet. The rabbits were all examined in vivo with HITACHI non-invasive vascular real-time elastography (Hi-RTE) at baseline and 12 wk, and results from the elastography were compared with American Heart Association histologic classifications. Hi-RTE and the American Heart Association histologic classifications had good agreement, with weighted Cohen's kappa (95% confidence internal) of 0.785 (0.649-0.920). Strains of segmented plaques that were stained in different colors were statistically different (p < 0.0001). The sensitivity and specificity of elastograms for detecting a lipid core were 95.5% and 61.5%, respectively, and the area under the receiver operating characteristic curve was 0.789, with a 95% confidence interval of 0.679 to 0.876. This study is the first to indicate the feasibility of utilizing Hi-RTE in visualizing normal and atherosclerotic rabbit carotid arteries non-invasively. This affordable and reliable method can be widely applied in research of both animal and human peripheral artery atherosclerosis.

  6. Single-step affinity purification of enzyme biotherapeutics: a platform methodology for accelerated process development.

    PubMed

    Brower, Kevin P; Ryakala, Venkat K; Bird, Ryan; Godawat, Rahul; Riske, Frank J; Konstantinov, Konstantin; Warikoo, Veena; Gamble, Jean

    2014-01-01

    Downstream sample purification for quality attribute analysis is a significant bottleneck in process development for non-antibody biologics. Multi-step chromatography process train purifications are typically required prior to many critical analytical tests. This prerequisite leads to limited throughput, long lead times to obtain purified product, and significant resource requirements. In this work, immunoaffinity purification technology has been leveraged to achieve single-step affinity purification of two different enzyme biotherapeutics (Fabrazyme® [agalsidase beta] and Enzyme 2) with polyclonal and monoclonal antibodies, respectively, as ligands. Target molecules were rapidly isolated from cell culture harvest in sufficient purity to enable analysis of critical quality attributes (CQAs). Most importantly, this is the first study that demonstrates the application of predictive analytics techniques to predict critical quality attributes of a commercial biologic. The data obtained using the affinity columns were used to generate appropriate models to predict quality attributes that would be obtained after traditional multi-step purification trains. These models empower process development decision-making with drug substance-equivalent product quality information without generation of actual drug substance. Optimization was performed to ensure maximum target recovery and minimal target protein degradation. The methodologies developed for Fabrazyme were successfully reapplied for Enzyme 2, indicating platform opportunities. The impact of the technology is significant, including reductions in time and personnel requirements, rapid product purification, and substantially increased throughput. Applications are discussed, including upstream and downstream process development support to achieve the principles of Quality by Design (QbD) as well as integration with bioprocesses as a process analytical technology (PAT).

  7. High speed intravascular photoacoustic imaging of atherosclerotic arteries (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Piao, Zhonglie; Ma, Teng; Qu, Yueqiao; Li, Jiawen; Yu, Mingyue; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2016-02-01

    Cardiovascular disease is the leading cause of death in the industrialized nations. Accurate quantification of both the morphology and composition of lipid-rich vulnerable atherosclerotic plaque are essential for early detection and optimal treatment in clinics. In previous works, intravascular photoacoustic (IVPA) imaging for detection of lipid-rich plaque within coronary artery walls has been demonstrated in ex vivo, but the imaging speed is still limited. In order to increase the imaging speed, a high repetition rate laser is needed. In this work, we present a high speed integrated IVPA/US imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A miniature catheter with 1.0 mm outer diameter was designed with a 200 μm multimode fiber and an ultrasound transducer with 45 MHz center frequency. The fiber was polished at 38 degree and enclosed in a glass capillary for total internal reflection. An optical/electrical rotary junction and pull-back mechanism was applied for rotating and linearly scanning the catheter to obtain three-dimensional imaging. Atherosclerotic rabbit abdominal aorta was imaged as two frame/second at 1725 nm. Furthermore, by wide tuning range of the laser wavelength from 1680 nm to 1770 nm, spectroscopic photoacoustic analysis of lipid-mimicking phantom and an human atherosclerotic artery was performed ex vivo. The results demonstrated that the developed IVPA/US imaging system is capable for high speed intravascular imaging for plaque detection.

  8. Quantitative analysis of the polarization characteristics of atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Gubarkova, Ekaterina V.; Kirillin, Michail Y.; Dudenkova, Varvara V.; Kiseleva, Elena B.; Moiseev, Alexander A.; Gelikonov, Grigory V.; Timofeeva, Lidia B.; Fiks, Ilya I.; Feldchtein, Felix I.; Gladkova, Natalia D.

    2016-04-01

    In this study we demonstrate the capability of cross-polarization optical coherence tomography (CP OCT) to assess collagen and elastin fibers condition in atherosclerotic plaques basing on ratio of the OCT signal levels in cross- and co- polarizations. We consider the depolarization factor (DF) and the effective birefringence (Δn) as quantitative characteristics of CP OCT images. We revealed that calculation of both DF and Δn in the region of interest (fibrous cap) yields a statistically significant difference between stable and unstable plaques (0.46+/-0.21 vs 0.09+/-0.04 for IDF; (4.7+/-1.0)•10-4 vs (2.5+/-0.7)•10-4 for Δn p<0.05). In parallel with CP OCT we used the nonlinear microscopy for analysis of thin cross-section of atherosclerotic plaque, revealing the different average isotropy index of collagen and elastin fibers for stable and unstable plaques (0.30 +/- 0.10 vs 0.70 +/- 0.08; p<0.001). The proposed approach for quantitative assessment of CP OCT images allows cross-scattering and birefringence characterization of stable and unstable atherosclerotic plaques.

  9. Small entities with large impact: microcalcifications and atherosclerotic plaque vulnerability

    PubMed Central

    Hutcheson, Joshua D.; Maldonado, Natalia; Aikawa, Elena

    2014-01-01

    Purpose of review Atherosclerotic plaque rupture and subsequent acute events, such as myocardial infarction and stroke, contribute to the majority of cardiovascular-related deaths. Calcification has emerged as a significant predictor of cardiovascular morbidity and mortality, challenging previously held notions that calcifications stabilize atherosclerotic plaques. In this review, we address this discrepancy through recent findings that not all calcifications are equivalent in determining plaque stability. Recent findings The risk associated with calcification is inversely associated with calcification density. As opposed to large calcifications that potentially stabilize the plaque, biomechanical modeling indicates that small microcalcifications within the plaque fibrous cap can lead to sufficient stress accumulation to cause plaque rupture. Microcalcifications appear to derive from matrix vesicles enriched in calcium-binding proteins that are released by cells within the plaque. Clinical detection of microcalcifications has been hampered by the lack of imaging resolution required for in-vivo visualization; however, recent studies have demonstrated promising new techniques to predict the presence of microcalcifications. Summary Microcalcifications play a major role in destabilizing atherosclerotic plaques. The identification of critical characteristics that lead to instability along with new imaging modalities to detect their presence in vivo may allow early identification and prevention of acute cardiovascular events. PMID:25188916

  10. Linear Accelerators

    SciTech Connect

    Sidorin, Anatoly

    2010-01-05

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  11. [Acceleration of osmotic dehydration process through ohmic heating of foods: raspberries (Rubus idaeus)].

    PubMed

    Simpson, Ricardo R; Jiménez, Maite P; Carevic, Erica G; Grancelli, Romina M

    2007-06-01

    Raspberries (Rubus idaeus) were osmotically dehydrated by applying a conventional method under the supposition of a homogeneous solution, all in a 62% glucose solution at 50 degrees C. Raspberries (Rubus idaeus) were also osmotically dehydrated by using ohmic heating in a 57% glucose solution at a variable voltage (to maintain temperature between 40 and 50 degrees C) and an electric field intensity <100 V/cm. When comparing the results from both experiments it was evident that processing time is reduced when ohmic heating technique was used. In some cases this reduction reached even 50%. This is explained by the additional effect to the thermal damage that is generated in an ohmic process, denominated electroporation.

  12. Denoising NMR time-domain signal by singular-value decomposition accelerated by graphics processing units.

    PubMed

    Man, Pascal P; Bonhomme, Christian; Babonneau, Florence

    2014-01-01

    We present a post-processing method that decreases the NMR spectrum noise without line shape distortion. As a result the signal-to-noise (S/N) ratio of a spectrum increases. This method is called Cadzow enhancement procedure that is based on the singular-value decomposition of time-domain signal. We also provide software whose execution duration is a few seconds for typical data when it is executed in modern graphic-processing unit. We tested this procedure not only on low sensitive nucleus (29)Si in hybrid materials but also on low gyromagnetic ratio, quadrupole nucleus (87)Sr in reference sample Sr(NO3)2. Improving the spectrum S/N ratio facilitates the determination of T/Q ratio of hybrid materials. It is also applicable to simulated spectrum, resulting shorter simulation duration for powder averaging. An estimation of the number of singular values needed for denoising is also provided. PMID:24880899

  13. Asymmetric neighborhood functions accelerate ordering process of self-organizing maps

    SciTech Connect

    Ota, Kaiichiro; Aoki, Takaaki; Kurata, Koji; Aoyagi, Toshio

    2011-02-15

    A self-organizing map (SOM) algorithm can generate a topographic map from a high-dimensional stimulus space to a low-dimensional array of units. Because a topographic map preserves neighborhood relationships between the stimuli, the SOM can be applied to certain types of information processing such as data visualization. During the learning process, however, topological defects frequently emerge in the map. The presence of defects tends to drastically slow down the formation of a globally ordered topographic map. To remove such topological defects, it has been reported that an asymmetric neighborhood function is effective, but only in the simple case of mapping one-dimensional stimuli to a chain of units. In this paper, we demonstrate that even when high-dimensional stimuli are used, the asymmetric neighborhood function is effective for both artificial and real-world data. Our results suggest that applying the asymmetric neighborhood function to the SOM algorithm improves the reliability of the algorithm. In addition, it enables processing of complicated, high-dimensional data by using this algorithm.

  14. The acceleration of spoken-word processing in children's native-language acquisition: an ERP cohort study.

    PubMed

    Ojima, Shiro; Matsuba-Kurita, Hiroko; Nakamura, Naoko; Hagiwara, Hiroko

    2011-04-01

    Healthy adults can identify spoken words at a remarkable speed, by incrementally analyzing word-onset information. It is currently unknown how this adult-level speed of spoken-word processing emerges during children's native-language acquisition. In a picture-word mismatch paradigm, we manipulated the semantic congruency between picture contexts and spoken words, and recorded event-related potential (ERP) responses to the words. Previous similar studies focused on the N400 response, but we focused instead on the onsets of semantic congruency effects (N200 or Phonological Mismatch Negativity), which contain critical information for incremental spoken-word processing. We analyzed ERPs obtained longitudinally from two age cohorts of 40 primary-school children (total n=80) in a 3-year period. Children first tested at 7 years of age showed earlier onsets of congruency effects (by approximately 70ms) when tested 2 years later (i.e., at age 9). Children first tested at 9 years of age did not show such shortening of onset latencies 2 years later (i.e., at age 11). Overall, children's onset latencies at age 9 appeared similar to those of adults. These data challenge the previous hypothesis that word processing is well established at age 7. Instead they support the view that the acceleration of spoken-word processing continues beyond age 7.

  15. Modulation of the phenolic composition and colour of red wines subjected to accelerated ageing by controlling process variables.

    PubMed

    González-Sáiz, J M; Esteban-Díez, I; Rodríguez-Tecedor, S; Pérez-Del-Notario, N; Arenzana-Rámila, I; Pizarro, C

    2014-12-15

    The aim of the present work was to evaluate the effect of the main factors conditioning accelerated ageing processes (oxygen dose, chip dose, wood origin, toasting degree and maceration time) on the phenolic and chromatic profiles of red wines by using a multivariate strategy based on experimental design methodology. The results obtained revealed that the concentrations of monomeric anthocyanins and flavan-3-ols could be modified through the application of particular experimental conditions. This fact was particularly remarkable since changes in phenolic profile were closely linked to changes observed in chromatic parameters. The main strength of this study lies in the possibility of using its conclusions as a basis to make wines with specific colour properties based on quality criteria. To our knowledge, the influence of such a large number of alternative ageing parameters on wine phenolic composition and chromatic attributes has not been studied previously using a comprehensive experimental design methodology.

  16. Evaluation of the radiolabeled boronic acid-based FAP inhibitor MIP-1232 for atherosclerotic plaque imaging.

    PubMed

    Meletta, Romana; Müller Herde, Adrienne; Chiotellis, Aristeidis; Isa, Malsor; Rancic, Zoran; Borel, Nicole; Ametamey, Simon M; Krämer, Stefanie D; Schibli, Roger

    2015-01-01

    Research towards the non-invasive imaging of atherosclerotic plaques is of high clinical priority as early recognition of vulnerable plaques may reduce the incidence of cardiovascular events. The fibroblast activation protein alpha (FAP) was recently proposed as inflammation-induced protease involved in the process of plaque vulnerability. In this study, FAP mRNA and protein levels were investigated by quantitative polymerase chain reaction and immunohistochemistry, respectively, in human endarterectomized carotid plaques. A published boronic-acid based FAP inhibitor, MIP-1232, was synthetized and radiolabeled with iodine-125. The potential of this radiotracer to image plaques was evaluated by in vitro autoradiography with human carotid plaques. Specificity was assessed with a xenograft with high and one with low FAP level, grown in mice. Target expression analyses revealed a moderately higher protein level in atherosclerotic plaques than normal arteries correlating with plaque vulnerability. No difference in expression was determined on mRNA level. The radiotracer was successfully produced and accumulated strongly in the FAP-positive SK-Mel-187 melanoma xenograft in vitro while accumulation was negligible in an NCI-H69 xenograft with low FAP levels. Binding of the tracer to endarterectomized tissue was similar in plaques and normal arteries, hampering its use for atherosclerosis imaging. PMID:25633335

  17. TRAIL-expressing T cells induce apoptosis of vascular smooth muscle cells in the atherosclerotic plaque

    PubMed Central

    Sato, Kayoko; Niessner, Alexander; Kopecky, Stephen L.; Frye, Robert L.; Goronzy, Jörg J.; Weyand, Cornelia M.

    2006-01-01

    Acute coronary syndromes (ACS) are precipitated by a rupture of the atherosclerotic plaque, often at the site of T cell and macrophage infiltration. Here, we show that plaque-infiltrating CD4 T cells effectively kill vascular smooth muscle cells (VSMC). VSMCs sensitive to T cell–mediated killing express the death receptor DR5 (TNF-related apoptosis-inducing ligand [TRAIL] receptor 2), and anti-TRAIL and anti-DR5 antibodies block T cell–mediated apoptosis. CD4 T cells that express TRAIL upon stimulation are expanded in patients with ACS and more effectively induce VSMC apoptosis. Adoptive transfer of plaque-derived CD4 T cells into immunodeficient mice that are engrafted with human atherosclerotic plaque results in apoptosis of VSMCs, which was prevented by coadministration of anti-TRAIL antibody. These data identify that the death pathway is triggered by TRAIL-producing CD4 T cells as a direct mechanism of VSMC apoptosis, a process which may lead to plaque destabilization. PMID:16418392

  18. Extraluminal laser angioplasty (ELAN): a new method for treating atherosclerotic vessels

    NASA Astrophysics Data System (ADS)

    Will, Fabian; Singh, Ajoy I.; Ertmer, Wolfgang; Welling, Herbert; Lubatschowski, Holger

    2003-06-01

    ELAN is a new method for treating atherosclerotic vessels. Its purpose is to restore wall flexibility by removing arterial wall tissue from the outer arterial layer. This leads to expansion of the narrowed vessel resulting in increased blood flow. We generated cuts in dissected arteries of sheep and pigs by photo-ablation with an ArF-Excimer Laser operating at a wavelength of 193 nm. During the cutting process the vessel diameter was monitored by measuring the running time of the laser induced pressure transients with a pressure transducer lying under the artery. A nearly linear increase of the diameter dependent on the residual wall thickness was found with a maximum increase of vessel diameter about 10%. We also observed that the arterial wall maintains stable to very small residual wall thicknesses i.e. deep cutting. To support the experiments and to test different geometries of tissue removal we performed FEM-Analysis. We simulated vessel deformation and the total strain depending on the depth, width and number of cuts in the outer artieral wall. We also found a significant increase of the "lumen" in a model with atherosclerotic shape obtained from a histological section.

  19. Adhesion molecules on the endothelium and mononuclear cells in human atherosclerotic lesions.

    PubMed Central

    van der Wal, A. C.; Das, P. K.; Tigges, A. J.; Becker, A. E.

    1992-01-01

    Atherosclerotic lesions show features of a cell-mediated immune inflammatory process. From this viewpoint, the potential role of arterial endothelium in the recruitment of mononuclear cells (T lymphocytes and macrophages) was studied. The endothelium of diffuse intimal thickening (DIT) and atheromatous plaques (AP) in human coronary arteries and abdominal aortas was characterized for the expression of adhesion molecules ELAM-1, ICAM-1, and the major histocompatibility complex (MHC) class II antigens HLA-DR/DP. A marked increase in expression of ICAM-1 and ELAM-1, and to a lesser extent HLA-DR/DP was observed on endothelial cells that were adjacent to subendothelial infiltrates of T lymphocytes (CD3+, CD11a+, HLA-DR/DP+) and macrophages (CD14+, CD11a+, CD11c+, HLA-DR/DP+). This contrasted with a lower or absent expression of these activation markers at sites without prominent inflammatory cell infiltrates. These findings could be demonstrated in DIT as well as in AP. The observations suggest that cytokines produced by the subintimal infiltrates may activate the endothelium in a similar way as is observed in the microvasculature at sites of immune inflammation. The expression of these activation markers in the microvasculature is associated with enhanced leukocyte adhesion, permeability for macromolecules, and procoagulant activity, features known to occur also in early experimental atherosclerosis. The findings therefore support the concept that arterial endothelium plays an active role in the recruitment of mononuclear cells in atherosclerotic lesions. Images Figure 1 PMID:1281621

  20. Plasma viscosity increase with progression of peripheral arterial atherosclerotic disease.

    PubMed

    Poredos, P; Zizek, B

    1996-03-01

    -macroglobulin (r=0.78, P < 0.01). These results indicate that in patients with peripheral arterial disease plasma viscosity increases with the progression of the atherosclerotic process and is correlated with the clinical stages of the disease.

  1. Hardware acceleration of PIC codes: tapping into the power of state of the art processing units

    NASA Astrophysics Data System (ADS)

    Fonseca, R. A.; Abreu, P.; Martins, S. F.; Silva, L. O.

    2008-11-01

    There are many astrophysical and laboratory scenarios where kinetic effects play an important role. Further understanding of these scenarios requires detailed numerical modeling using fully relativistic three-dimensional kinetic code such as OSIRIS [1]. However, these codes are computationally heavy. Explicitly using available hardware resources such as SIMD units (Altivec/SSE3) [2], cell processors or graphics processing units (GPUs) may allow us to significantly boost performance of these codes. For the most cases, the processing units are limited to single precision arithmetic, and require specific C/C++ code to be used. We present a comparison between double precision and single precision results, focusing both on performance and on the effects on the simulation in terms of algorithm properties. Details on a framework allowing the integration of hardware optimized routines with existing high performance codes in languages other than C is given. Finally, initial results of high performance modules of the PIC algorithm using SIMD units and GPU's will also be presented. [1] R. A. Fonseca et al., LNCS 2331, 342, (2002) [2] K. J. Bowers et al., Phys Plasmas vol. 15 (5) pp. 055703 (2008)

  2. Audit Report on "Waste Processing and Recovery Act Acceleration Efforts for Contact-Handled Transuranic Waste at the Hanford Site"

    SciTech Connect

    2010-05-01

    The Department of Energy's Office of Environmental Management's (EM), Richland Operations Office (Richland), is responsible for disposing of the Hanford Site's (Hanford) transuranic (TRU) waste, including nearly 12,000 cubic meters of radioactive contact-handled TRU wastes. Prior to disposing of this waste at the Department's Waste Isolation Pilot Plant (WIPP), Richland must certify that it meets WIPP's waste acceptance criteria. To be certified, the waste must be characterized, screened for prohibited items, treated (if necessary) and placed into a satisfactory disposal container. In a February 2008 amendment to an existing Record of Decision (Decision), the Department announced its plan to ship up to 8,764 cubic meters of contact-handled TRU waste from Hanford and other waste generator sites to the Advanced Mixed Waste Treatment Project (AMWTP) at Idaho's National Laboratory (INL) for processing and certification prior to disposal at WIPP. The Department decided to maximize the use of the AMWTP's automated waste processing capabilities to compact and, thereby, reduce the volume of contact-handled TRU waste. Compaction reduces the number of shipments and permits WIPP to more efficiently use its limited TRU waste disposal capacity. The Decision noted that the use of AMWTP would avoid the time and expense of establishing a processing capability at other sites. In May 2009, EM allocated $229 million of American Recovery and Reinvestment Act of 2009 (Recovery Act) funds to support Hanford's Solid Waste Program, including Hanford's contact-handled TRU waste. Besides providing jobs, these funds were intended to accelerate cleanup in the short term. We initiated this audit to determine whether the Department was effectively using Recovery Act funds to accelerate processing of Hanford's contact-handled TRU waste. Relying on the availability of Recovery Act funds, the Department changed course and approved an alternative plan that could increase costs by about $25 million

  3. Influence of processing procedure on the quality of Radix Scrophulariae: a quantitative evaluation of the main compounds obtained by accelerated solvent extraction and high-performance liquid chromatography.

    PubMed

    Cao, Gang; Wu, Xin; Li, Qinglin; Cai, Hao; Cai, Baochang; Zhu, Xuemei

    2015-02-01

    An improved high-performance liquid chromatography with diode array detection combined with accelerated solvent extraction method was used to simultaneously determine six compounds in crude and processed Radix Scrophulariae samples. Accelerated solvent extraction parameters such as extraction solvent, temperature, number of cycles, and analysis procedure were systematically optimized. The results indicated that compared with crude Radix Scrophulariae samples, the processed samples had lower contents of harpagide and harpagoside but higher contents of catalpol, acteoside, angoroside C, and cinnamic acid. The established method was sufficiently rapid and reliable for the global quality evaluation of crude and processed herbal medicines.

  4. Using general-purpose computing on graphics processing units (GPGPU) to accelerate the ordinary kriging algorithm

    NASA Astrophysics Data System (ADS)

    Gutiérrez de Ravé, E.; Jiménez-Hornero, F. J.; Ariza-Villaverde, A. B.; Gómez-López, J. M.

    2014-03-01

    Spatial interpolation methods have been applied to many disciplines, the ordinary kriging interpolation being one of the methods most frequently used. However, kriging comprises a computational cost that scales as the cube of the number of data points. Therefore, one most pressing problems in geostatistical simulations is that of developing methods that can reduce the computational time. Weights calculation and then the estimate for each unknown point is the most time-consuming step in ordinary kriging. This work investigates the potential reduction in execution time by selecting the suitable operations involved in this step to be parallelized by using general-purpose computing on graphics processing units (GPGPU) and Compute Unified Device Architecture (CUDA). This study has been performed by taking into account comparative studies between graphic and central processing units on two different machines, a personal computer (GPU, GeForce 9500, and CPU, AMD Athlon X2 4600) and a server (GPU, Tesla C1060, and CPU, Xeon 5600). In addition, two data types (float and double) have been considered in the executions. The experimental results indicate that parallel implementation of matrix inverse by using GPGPU and CUDA will be enough to reduce the execution time of weights calculation and estimation for each unknown point and, as a result, the global performance time of ordinary kriging. In addition, suitable array dimensions for using the available parallelized code have been determined for each case. Thus, it is possible to obtain relevant saved times compared to those resulting from considering wider parallelized extension. This fact demonstrates the convenience of carrying out this kind of study in other interpolation calculation methodologies using matrices.

  5. Stationary and high-frequency pulsed electron paramagnetic resonance of a calcified atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Abdul'Yanov, V. A.; Galiullina, L. F.; Galyavich, A. S.; Izotov, V. G.; Mamin, G. V.; Orlinskii, S. B.; Rodionov, A. A.; Salakhov, M. Kh.; Silkin, N. I.; Sitdikova, L. M.; Khairullin, R. N.; Chelyshev, Yu. A.

    2008-09-01

    New possibilities of applying high-frequency electron paramagnetic resonance in medicine are demonstrated on an example of the investigation of a calcified atherosclerotic plaque. After the irradiation of the atherosclerotic plaque by x rays, a new type of paramagnetic centers—organomineral radicals—is detected. The spectral and relaxation characteristics of these radicals depend on the calcification degree of the atherosclerotic plaque and can be used for diagnostics.

  6. Graphic processing unit accelerated real-time partially coherent beam generator

    NASA Astrophysics Data System (ADS)

    Ni, Xiaolong; Liu, Zhi; Chen, Chunyi; Jiang, Huilin; Fang, Hanhan; Song, Lujun; Zhang, Su

    2016-07-01

    A method of using liquid-crystals (LCs) to generate a partially coherent beam in real-time is described. An expression for generating a partially coherent beam is given and calculated using a graphic processing unit (GPU), i.e., the GeForce GTX 680. A liquid-crystal on silicon (LCOS) with 256 × 256 pixels is used as the partially coherent beam generator (PCBG). An optimizing method with partition convolution is used to improve the generating speed of our LC PCBG. The total time needed to generate a random phase map with a coherence width range from 0.015 mm to 1.5 mm is less than 2.4 ms for calculation and readout with the GPU; adding the time needed for the CPU to read and send to LCOS with the response time of the LC PCBG, the real-time partially coherent beam (PCB) generation frequency of our LC PCBG is up to 312 Hz. To our knowledge, it is the first real-time partially coherent beam generator. A series of experiments based on double pinhole interference are performed. The result shows that to generate a laser beam with a coherence width of 0.9 mm and 1.5 mm, with a mean error of approximately 1%, the RMS values needed 0.021306 and 0.020883 and the PV values required 0.073576 and 0.072998, respectively.

  7. Accelerated evaluation of the robustness of treatment plans against geometric uncertainties by Gaussian processes.

    PubMed

    Sobotta, B; Söhn, M; Alber, M

    2012-12-01

    In order to provide a consistently high quality treatment, it is of great interest to assess the robustness of a treatment plan under the influence of geometric uncertainties. One possible method to implement this is to run treatment simulations for all scenarios that may arise from these uncertainties. These simulations may be evaluated in terms of the statistical distribution of the outcomes (as given by various dosimetric quality metrics) or statistical moments thereof, e.g. mean and/or variance. This paper introduces a method to compute the outcome distribution and all associated values of interest in a very efficient manner. This is accomplished by substituting the original patient model with a surrogate provided by a machine learning algorithm. This Gaussian process (GP) is trained to mimic the behavior of the patient model based on only very few samples. Once trained, the GP surrogate takes the place of the patient model in all subsequent calculations.The approach is demonstrated on two examples. The achieved computational speedup is more than one order of magnitude.

  8. Rock varnish in New York: An accelerated snapshot of accretionary processes

    NASA Astrophysics Data System (ADS)

    Krinsley, David H.; Dorn, Ronald I.; DiGregorio, Barry E.; Langworthy, Kurt A.; Ditto, Jeffrey

    2012-02-01

    Samples of manganiferous rock varnish collected from fluvial, bedrock outcrop and Erie Barge Canal settings in New York state host a variety of diatom, fungal and bacterial microbial forms that are enhanced in manganese and iron. Use of a Dual-Beam Focused Ion Beam Scanning Electron Microscope to manipulate the varnish in situ reveals microbial forms that would not have otherwise been identified. The relative abundance of Mn-Fe-enriched biotic forms in New York samples is far greater than varnishes collected from warm deserts. Moisture availability has long been noted as a possible control on varnish growth rates, a hypothesis consistent with the greater abundance of Mn-enhancing bioforms. Sub-micron images of incipient varnish formation reveal that varnishing in New York probably starts with the mortality of microorganisms that enhanced Mn on bare mineral surfaces; microbial death results in the adsorption of the Mn-rich sheath onto the rock in the form of filamentous networks. Clay minerals are then cemented by remobilization of the Mn-rich material. Thus, the previously unanswered question of what comes first - clay mineral deposition or enhancement of Mn - can be answered in New York because of the faster rate of varnish growth. In contrast, very slow rates of varnishing seen in warm deserts, of microns per thousand years, make it less likely that collected samples will reveal varnish accretionary processes than samples collected from fast-accreting moist settings.

  9. Computational Hemodynamic Analysis for the Diagnosis of Atherosclerotic Changes in Intracranial Aneurysms: A Proof-of-Concept Study Using 3 Cases Harboring Atherosclerotic and Nonatherosclerotic Aneurysms Simultaneously

    PubMed Central

    Endo, Hidenori; Niizuma, Kuniyasu; Endo, Toshiki; Funamoto, Kenichi; Ohta, Makoto; Tominaga, Teiji

    2016-01-01

    This was a proof-of-concept computational fluid dynamics (CFD) study designed to identify atherosclerotic changes in intracranial aneurysms. We selected 3 patients with multiple unruptured aneurysms including at least one with atherosclerotic changes and investigated whether an image-based CFD study could provide useful information for discriminating the atherosclerotic aneurysms. Patient-specific geometries were constructed from three-dimensional data obtained using rotational angiography. Transient simulations were conducted under patient-specific inlet flow rates measured by phase-contrast magnetic resonance velocimetry. In the postanalyses, we calculated time-averaged wall shear stress (WSS), oscillatory shear index, and relative residence time (RRT). The volume of blood flow entering aneurysms through the neck and the mean velocity of blood flow inside aneurysms were examined. We applied the age-of-fluid method to quantitatively assess the residence of blood inside aneurysms. Atherosclerotic changes coincided with regions exposed to disturbed blood flow, as indicated by low WSS and long RRT. Blood entered aneurysms in phase with inlet flow rates. The mean velocities of blood inside atherosclerotic aneurysms were lower than those inside nonatherosclerotic aneurysms. Blood in atherosclerotic aneurysms was older than that in nonatherosclerotic aneurysms, especially near the wall. This proof-of-concept study demonstrated that CFD analysis provided detailed information on the exchange and residence of blood that is useful for the diagnosis of atherosclerotic changes in intracranial aneurysms. PMID:27703491

  10. Accelerators and the Accelerator Community

    SciTech Connect

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  11. Can Accelerators Accelerate Learning?

    NASA Astrophysics Data System (ADS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  12. Can Accelerators Accelerate Learning?

    SciTech Connect

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-10

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  13. Grid-based algorithm to search critical points, in the electron density, accelerated by graphics processing units.

    PubMed

    Hernández-Esparza, Raymundo; Mejía-Chica, Sol-Milena; Zapata-Escobar, Andy D; Guevara-García, Alfredo; Martínez-Melchor, Apolinar; Hernández-Pérez, Julio-M; Vargas, Rubicelia; Garza, Jorge

    2014-12-01

    Using a grid-based method to search the critical points in electron density, we show how to accelerate such a method with graphics processing units (GPUs). When the GPU implementation is contrasted with that used on central processing units (CPUs), we found a large difference between the time elapsed by both implementations: the smallest time is observed when GPUs are used. We tested two GPUs, one related with video games and other used for high-performance computing (HPC). By the side of the CPUs, two processors were tested, one used in common personal computers and other used for HPC, both of last generation. Although our parallel algorithm scales quite well on CPUs, the same implementation on GPUs runs around 10× faster than 16 CPUs, with any of the tested GPUs and CPUs. We have found what one GPU dedicated for video games can be used without any problem for our application, delivering a remarkable performance, in fact; this GPU competes against one HPC GPU, in particular when single-precision is used. PMID:25345784

  14. Identification of Atherosclerotic Plaques in Carotid Artery by Fluorescence Spectroscopy

    NASA Astrophysics Data System (ADS)

    Rocha, Rick; Villaverde, Antonio Balbin; Silveira, Landulfo; Costa, Maricília Silva; Alves, Leandro Procópio; Pasqualucci, Carlos Augusto; Brugnera, Aldo

    2008-04-01

    The aim of this work was to identify the presence of atherosclerotic plaques in carotid artery using the Fluorescence Spectroscopy. The most important pathogeny in the cardiovascular disorders is the atherosclerosis, which may affect even younger individuals. With approximately 1.2 million heart attacks and 750,000 strokes afflicting an aging American population each year, cardiovascular disease remains the number one cause of death. Carotid artery samples were obtained from the Autopsy Service at the University of São Paulo (São Paulo, SP, Brazil) taken from cadavers. After a histopathological analysis the 60 carotid artery samples were divided into two groups: normal (26) and atherosclerotic plaques (34). Samples were irradiated with the wavelength of 488 nm from an Argon laser. A 600 μm core optical fiber, coupled to the Argon laser, was used for excitation of the sample, whereas another 600 optical fiber, coupled to the spectrograph entrance slit, was used for collecting the fluorescence from the sample. Measurements were taken at different points on each sample and then averaged. Fluorescence spectra showed a single broad line centered at 549 nm. The fluorescence intensity for each sample was calculated by subtracting the intensity at the peak (550 nm) and at the bottom (510 nm) and then data were statistically analyzed, looking for differences between both groups of samples. ANOVA statistical test showed a significant difference (p<0,05) between both types of tissues, with regard to the fluorescence peak intensities. Our results indicate that this technique could be used to detect the presence of the atherosclerotic in carotid tissue.

  15. Effect of accelerated electron beam on mechanical properties of human cortical bone: influence of different processing methods.

    PubMed

    Kaminski, Artur; Grazka, Ewelina; Jastrzebska, Anna; Marowska, Joanna; Gut, Grzegorz; Wojciechowski, Artur; Uhrynowska-Tyszkiewicz, Izabela

    2012-08-01

    Accelerated electron beam (EB) irradiation has been a sufficient method used for sterilisation of human tissue grafts for many years in a number of tissue banks. Accelerated EB, in contrast to more often used gamma photons, is a form of ionizing radiation that is characterized by lower penetration, however it is more effective in producing ionisation and to reach the same level of sterility, the exposition time of irradiated product is shorter. There are several factors, including dose and temperature of irradiation, processing conditions, as well as source of irradiation that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect e-beam irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors, aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as e-beam irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress-strain curves examined by univariate analysis are described. Based on multivariate analysis, including all groups, it was found that temperature of e-beam irradiation and defatting had no consistent significant effect on evaluated mechanical parameters of compact bone rings. In contrast, irradiation with both doses significantly decreased the ultimate strain and its derivative toughness, while not affecting the ultimate stress (bone strength). As no deterioration of mechanical properties was observed in the elastic region, the reduction of the energy

  16. Atherosclerotic plaque detection by confocal Brillouin and Raman microscopies

    NASA Astrophysics Data System (ADS)

    Meng, Zhaokai; Basagaoglu, Berkay; Yakovlev, Vladislav V.

    2015-02-01

    Atherosclerosis, the development of intraluminal plaque, is a fundamental pathology of cardiovascular system and remains the leading cause of morbidity and mortality worldwide. Biomechanical in nature, plaque rupture occurs when the mechanical properties of the plaque, related to the morphology and viscoelastic properties, are compromised, resulting in intraluminal thrombosis and reduction of coronary blood flow. In this report, we describe the first simultaneous application of confocal Brillouin and Raman microscopies to ex-vivo aortic wall samples. Such a non-invasive, high specific approach allows revealing a direct relationship between the biochemical and mechanical properties of atherosclerotic tissue.

  17. Three-dimensional dynamic contrast-enhanced MRI for the accurate, extensive quantification of microvascular permeability in atherosclerotic plaques.

    PubMed

    Calcagno, Claudia; Lobatto, Mark E; Dyvorne, Hadrien; Robson, Philip M; Millon, Antoine; Senders, Max L; Lairez, Olivier; Ramachandran, Sarayu; Coolen, Bram F; Black, Alexandra; Mulder, Willem J M; Fayad, Zahi A

    2015-10-01

    Atherosclerotic plaques that cause stroke and myocardial infarction are characterized by increased microvascular permeability and inflammation. Dynamic contrast-enhanced MRI (DCE-MRI) has been proposed as a method to quantify vessel wall microvascular permeability in vivo. Until now, most DCE-MRI studies of atherosclerosis have been limited to two-dimensional (2D) multi-slice imaging. Although providing the high spatial resolution required to image the arterial vessel wall, these approaches do not allow the quantification of plaque permeability with extensive anatomical coverage, an essential feature when imaging heterogeneous diseases, such as atherosclerosis. To our knowledge, we present the first systematic evaluation of three-dimensional (3D), high-resolution, DCE-MRI for the extensive quantification of plaque permeability along an entire vascular bed, with validation in atherosclerotic rabbits. We compare two acquisitions: 3D turbo field echo (TFE) with motion-sensitized-driven equilibrium (MSDE) preparation and 3D turbo spin echo (TSE). We find 3D TFE DCE-MRI to be superior to 3D TSE DCE-MRI in terms of temporal stability metrics. Both sequences show good intra- and inter-observer reliability, and significant correlation with ex vivo permeability measurements by Evans Blue near-infrared fluorescence (NIRF). In addition, we explore the feasibility of using compressed sensing to accelerate 3D DCE-MRI of atherosclerosis, to improve its temporal resolution and therefore the accuracy of permeability quantification. Using retrospective under-sampling and reconstructions, we show that compressed sensing alone may allow the acceleration of 3D DCE-MRI by up to four-fold. We anticipate that the development of high-spatial-resolution 3D DCE-MRI with prospective compressed sensing acceleration may allow for the more accurate and extensive quantification of atherosclerotic plaque permeability along an entire vascular bed. We foresee that this approach may allow for

  18. Monitoring of pigmented and wooden surfaces in accelerated ageing processes by FT-Raman spectroscopy and multivariate control charts.

    PubMed

    Marengo, Emilio; Robotti, Elisa; Liparota, Maria Cristina; Gennaro, Maria Carla

    2004-07-01

    Two of the most suitable analytical techniques used in the field of cultural heritage are NIR (near-infrared) and Raman spectroscopy. FT-Raman spectroscopy coupled to multivariate control charts is applied here for the development of a new method for monitoring the conservation state of pigmented and wooden surfaces. These materials were exposed to different accelerated ageing processes in order to evaluate the effect of the applied treatments on the goods surfaces. In this work, a new approach based on the principles of statistical process control (SPC) to the monitoring of cultural heritage, has been developed: the conservation state of samples simulating works-of-art has been treated like an industrial process, monitored with multivariate control charts, owing to the complexity of the spectroscopic data collected. The Raman spectra were analysed by principal component analysis (PCA) and the relevant principal components (PCs) were used for constructing multivariate Shewhart and cumulative sum (CUSUM) control charts. These tools were successfully applied for the identification of the presence of relevant modifications occurring on the surfaces. CUSUM charts however proved to be more effective in the identification of the exact beginning of the applied treatment. In the case of wooden boards, where a sufficient number of PCs were available, simultaneous scores monitoring and residuals tracking (SMART) charts were also investigated. The exposure to a basic attack and to high temperatures produced deep changes on the wooden samples, clearly identified by the multivariate Shewhart, CUSUM and SMART charts. A change on the pigment surface was detected after exposure to an acidic solution and to the UV light, while no effect was identified on the painted surface after the exposure to natural atmospheric events. PMID:18969526

  19. EMITTING ELECTRONS SPECTRA AND ACCELERATION PROCESSES IN THE JET OF Mrk 421: FROM THE LOW STATE TO THE GIANT FLARE STATE

    SciTech Connect

    Yan Dahai; Zhang Li; Fan Zhonghui; Zeng Houdun; Yuan Qiang

    2013-03-10

    We investigate the electron energy distributions (EEDs) and the acceleration processes in the jet of Mrk 421 through fitting the spectral energy distributions (SEDs) in different active states in the frame of a one-zone synchrotron self-Compton model. After assuming two possible EEDs formed in different acceleration models: the shock-accelerated power law with exponential cut-off (PLC) EED and the stochastic-turbulence-accelerated log-parabolic (LP) EED, we fit the observed SEDs of Mrk 421 in both low and giant flare states using the Markov Chain Monte Carlo method which constrains the model parameters in a more efficient way. The results from our calculations indicate that (1) the PLC and LP models give comparably good fits for the SED in the low state, but the variations of model parameters from low state to flaring can be reasonably explained only in the case of the PLC in the low state; and (2) the LP model gives better fits compared to the PLC model for the SED in the flare state, and the intra-day/night variability observed at GeV-TeV bands can be accommodated only in the LP model. The giant flare may be attributed to the stochastic turbulence re-acceleration of the shock-accelerated electrons in the low state. Therefore, we may conclude that shock acceleration is dominant in the low state, while stochastic turbulence acceleration is dominant in the flare state. Moreover, our result shows that the extrapolated TeV spectra from the best-fit SEDs from optical through GeV with the two EEDs are different. It should be considered with caution when such extrapolated TeV spectra are used to constrain extragalactic background light models.

  20. Evaluation of acceleration and deceleration cardiac processes using phase-rectified signal averaging in healthy and idiopathic dilated cardiomyopathy subjects.

    PubMed

    Bas, Rosana; Vallverdú, Montserrat; Valencia, Jose F; Voss, Andreas; de Luna, Antonio Bayés; Caminal, Pere

    2015-02-01

    The aim of the present study was to investigate the suitability of the Phase-Rectified Signal Averaging (PRSA) method for improved risk prediction in cardiac patients. Moreover, this technique, which separately evaluates acceleration and deceleration processes of cardiac rhythm, allows the effect of sympathetic and vagal modulations of beat-to-beat intervals to be characterized. Holter recordings of idiopathic dilated cardiomyopathy (IDC) patients were analyzed: high-risk (HR), who suffered sudden cardiac death (SCD) during the follow-up; and low-risk (LR), without any kind of cardiac-related death. Moreover, a control group of healthy subjects was analyzed. PRSA indexes were analyzed, for different time scales T and wavelet scales s, from RR series of 24 h-ECG recordings, awake periods and sleep periods. Also, the behavior of these indexes from simulated data was analyzed and compared with real data results. Outcomes demonstrated the PRSA capacity to significantly discriminate healthy subjects from IDC patients and HR from LR patients on a higher level than traditional temporal and spectral measures. The behavior of PRSA indexes agrees with experimental evidences related to cardiac autonomic modulations. Also, these parameters reflect more regularity of the autonomic nervous system (ANS) in HR patients. PMID:25585858

  1. Expression of cartilage-specific markers in calcified and non-calcified atherosclerotic lesions.

    PubMed

    Aigner, Thomas; Neureiter, Daniel; Câmpean, Valentina; Soder, Stephan; Amann, Kerstin

    2008-01-01

    Recently, molecular mechanisms resembling endochondral ossification were suggested to be important for atherosclerotic vessel calcification. The aim of this study was to investigate in a series of human atherosclerotic (non-diabetic) lesions of the crural arteries the distribution and expression of classical marker genes of the endochondral ossification pathway. Immunostaining for marker proteins S-100 protein and collagen types II and X were performed on atherosclerotic lesions of different grades (according to Stary). Quantitative real-time PCR for human COL1A1, COL2A1, COL10A1, SOX9, and BMP-2 was applied on RNA isolated from atherosclerotic arteries. In most samples, no expression of collagen type II and S-100 protein was found. Exceptionally, S-100 protein and type II collagen expression was observed very focally within advanced atherosclerotic plaques. Type X collagen was not detected in any of the lesions investigated. Overall, in our study we found no evidence that chondrogenic differentiation pathways are generally active in atherosclerotic plaque formation. In particular type X collagen, one important molecule in cartilage calcification, was not expressed in any of the investigated specimens. Occasionally, however, chondrocytic differentiation markers occur within atherosclerotic lesions. This most likely represents a metaplastic event associated, but not causative for atherosclerotic vessel degeneration and calcification. PMID:17335825

  2. Compact Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2004-01-01

    A plasma accelerator has been conceived for both material-processing and spacecraft-propulsion applications. This accelerator generates and accelerates ions within a very small volume. Because of its compactness, this accelerator could be nearly ideal for primary or station-keeping propulsion for spacecraft having masses between 1 and 20 kg. Because this accelerator is designed to generate beams of ions having energies between 50 and 200 eV, it could also be used for surface modification or activation of thin films.

  3. Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque

    SciTech Connect

    Saba, Luca; Potters, Fons; Lugt, Aad van der; Mallarini, Giorgio

    2010-08-15

    In the last two decades, a substantial number of articles have been published to provide diagnostic solutions for patients with carotid atherosclerotic disease. These articles have resulted in a shift of opinion regarding the identification of stroke risk in patients with carotid atherosclerotic disease. In the recent past, the degree of carotid artery stenosis was the sole determinant for performing carotid intervention (carotid endarterectomy or carotid stenting) in these patients. We now know that the degree of stenosis is only one marker for future cerebrovascular events. If one wants to determine the risk of these events more accurately, other parameters must be taken into account; among these parameters are plaque composition, presence and state of the fibrous cap (FC), intraplaque haemorrhage, plaque ulceration, and plaque location. In particular, the FC is an important structure for the stability of the plaque, and its rupture is highly associated with a recent history of transient ischaemic attack or stroke. The subject of this review is imaging of the FC.

  4. Noninvasive imaging of focal atherosclerotic lesions using fluorescence molecular tomography

    NASA Astrophysics Data System (ADS)

    Maji, Dolonchampa; Solomon, Metasebya; Nguyen, Annie; Pierce, Richard A.; Woodard, Pamela K.; Akers, Walter J.; Achilefu, Samuel; Culver, Joseph P.; Abendschein, Dana R.; Shokeen, Monica

    2014-11-01

    Insights into the etiology of stroke and myocardial infarction suggest that rupture of unstable atherosclerotic plaque is the precipitating event. Clinicians lack tools to detect lesion instability early enough to intervene, and are often left to manage patients empirically, or worse, after plaque rupture. Noninvasive imaging of the molecular events signaling prerupture plaque progression has the potential to reduce the morbidity and mortality associated with myocardial infarction and stroke by allowing early intervention. Here, we demonstrate proof-of-principle in vivo molecular imaging of C-type natriuretic peptide receptor in focal atherosclerotic lesions in the femoral arteries of New Zealand white rabbits using a custom built fiber-based, fluorescence molecular tomography (FMT) system. Longitudinal imaging showed changes in the fluorescence signal intensity as the plaque progressed in the air-desiccated vessel compared to the uninjured vessel, which was validated by ex vivo tissue studies. In summary, we demonstrate the potential of FMT for noninvasive detection of molecular events leading to unstable lesions heralding plaque rupture.

  5. Microcalcifications in Early Intimal Lesions of Atherosclerotic Human Coronary Arteries

    PubMed Central

    Roijers, Ruben B.; Debernardi, Nicola; Cleutjens, Jack P.M.; Schurgers, Leon J.; Mutsaers, Peter H.A.; van der Vusse, Ger J.

    2011-01-01

    Although calcium (Ca) precipitation may play a pathogenic role in atherosclerosis, information on temporal patterns of microcalcifications in human coronary arteries, their relation to expression of calcification-regulating proteins, and colocalization with iron (Fe) and zinc (Zn) is scarce. Human coronary arteries were analyzed post mortem with a proton microprobe for element concentrations and stained (immuno)histochemically for morphological and calcification-regulating proteins. Microcalcifications were occasionally observed in preatheroma type I atherosclerotic intimal lesions. Their abundance increased in type II, III, and IV lesions. Moreover, their appearance preceded increased expression of calcification-regulating proteins, such as osteocalcin and bone morphogenetic protein-2. In contrast, their presence coincided with increased expression of uncarboxylated matrix Gla protein (MGP), whereas the content of carboxylated MGP was increased in type III and IV lesions, indicating delayed posttranslational conversion of biologically inactive into active MGP. Ca/phosphorus ratios of the microcalcifications varied from 1.6 to 3.0, including amorphous Ca phosphates. Approximately 75% of microcalcifications colocalized with the accumulation of Fe and Zn. We conclude that Ca microprecipitation occurs in the early stages of atherosclerosis, inferring a pathogenic role in the sequel of events, resulting in overt atherosclerotic lesions. Microcalcifications may be caused by local events triggering the precipitation of Ca rather than by increased expression of calcification-regulating proteins. The high degree of colocalization with Fe and Zn suggests a mutual relationship between these trace elements and early deposition of Ca salts. PMID:21531376

  6. Laser speckle imaging of atherosclerotic plaques through optical fiber bundles.

    PubMed

    Nadkarni, Seemantini K; Bouma, Brett E; Yelin, Dvir; Gulati, Amneet; Tearney, Guillermo J

    2008-01-01

    Laser speckle imaging (LSI), a new technique that measures an index of plaque viscoelasticity, has been investigated recently to characterize atherosclerotic plaques. These prior studies demonstrated the diagnostic potential of LSI for detecting high-risk plaques and were conducted ex vivo. To conduct intracoronary LSI in vivo, the laser speckle pattern must be transmitted from the coronary wall to the image detector in the presence of cardiac motion. Small-diameter, flexible optical fiber bundles, similar to those used in coronary angioscopy, may be incorporated into an intravascular catheter for this purpose. A key challenge is that laser speckle is influenced by inter-fiber leakage of light, which may be exacerbated during bundle motion. In this study, we tested the capability of optical fiber bundles to transmit laser speckle patterns obtained from atherosclerotic plaques and evaluated the influence of motion on the diagnostic accuracy of fiber bundle-based LSI. Time-varying helium-neon laser speckle images of aortic plaques were obtained while cyclically moving the flexible length of the bundle to mimic coronary motion. Our results show that leached fiber bundles may reliably transmit laser speckle images in the presence of cardiac motion, providing a viable option to conduct intracoronary LSI. PMID:19021396

  7. Numerical observer for atherosclerotic plaque classification in spectral computed tomography.

    PubMed

    Lorsakul, Auranuch; Fakhri, Georges El; Worstell, William; Ouyang, Jinsong; Rakvongthai, Yothin; Laine, Andrew F; Li, Quanzheng

    2016-07-01

    Spectral computed tomography (SCT) generates better image quality than conventional computed tomography (CT). It has overcome several limitations for imaging atherosclerotic plaque. However, the literature evaluating the performance of SCT based on objective image assessment is very limited for the task of discriminating plaques. We developed a numerical-observer method and used it to assess performance on discrimination vulnerable-plaque features and compared the performance among multienergy CT (MECT), dual-energy CT (DECT), and conventional CT methods. Our numerical observer was designed to incorporate all spectral information and comprised two-processing stages. First, each energy-window domain was preprocessed by a set of localized channelized Hotelling observers (CHO). In this step, the spectral image in each energy bin was decorrelated using localized prewhitening and matched filtering with a set of Laguerre-Gaussian channel functions. Second, the series of the intermediate scores computed from all the CHOs were integrated by a Hotelling observer with an additional prewhitening and matched filter. The overall signal-to-noise ratio (SNR) and the area under the receiver operating characteristic curve (AUC) were obtained, yielding an overall discrimination performance metric. The performance of our new observer was evaluated for the particular binary classification task of differentiating between alternative plaque characterizations in carotid arteries. A clinically realistic model of signal variability was also included in our simulation of the discrimination tasks. The inclusion of signal variation is a key to applying the proposed observer method to spectral CT data. Hence, the task-based approaches based on the signal-known-exactly/background-known-exactly (SKE/BKE) framework and the clinical-relevant signal-known-statistically/background-known-exactly (SKS/BKE) framework were applied for analytical computation of figures of merit (FOM). Simulated data of a

  8. Numerical observer for atherosclerotic plaque classification in spectral computed tomography.

    PubMed

    Lorsakul, Auranuch; Fakhri, Georges El; Worstell, William; Ouyang, Jinsong; Rakvongthai, Yothin; Laine, Andrew F; Li, Quanzheng

    2016-07-01

    Spectral computed tomography (SCT) generates better image quality than conventional computed tomography (CT). It has overcome several limitations for imaging atherosclerotic plaque. However, the literature evaluating the performance of SCT based on objective image assessment is very limited for the task of discriminating plaques. We developed a numerical-observer method and used it to assess performance on discrimination vulnerable-plaque features and compared the performance among multienergy CT (MECT), dual-energy CT (DECT), and conventional CT methods. Our numerical observer was designed to incorporate all spectral information and comprised two-processing stages. First, each energy-window domain was preprocessed by a set of localized channelized Hotelling observers (CHO). In this step, the spectral image in each energy bin was decorrelated using localized prewhitening and matched filtering with a set of Laguerre-Gaussian channel functions. Second, the series of the intermediate scores computed from all the CHOs were integrated by a Hotelling observer with an additional prewhitening and matched filter. The overall signal-to-noise ratio (SNR) and the area under the receiver operating characteristic curve (AUC) were obtained, yielding an overall discrimination performance metric. The performance of our new observer was evaluated for the particular binary classification task of differentiating between alternative plaque characterizations in carotid arteries. A clinically realistic model of signal variability was also included in our simulation of the discrimination tasks. The inclusion of signal variation is a key to applying the proposed observer method to spectral CT data. Hence, the task-based approaches based on the signal-known-exactly/background-known-exactly (SKE/BKE) framework and the clinical-relevant signal-known-statistically/background-known-exactly (SKS/BKE) framework were applied for analytical computation of figures of merit (FOM). Simulated data of a

  9. Symptomatic Atherosclerotic Disease and Decreased Risk of Cancer-Specific Mortality

    PubMed Central

    Benito-León, Julián; de la Aleja, Jesús González; Martínez-Salio, Antonio; Louis, Elan D.; Lichtman, Judith H.; Bermejo-Pareja, Félix

    2015-01-01

    Abstract The few studies that have assessed the association between symptomatic atherosclerotic disease and risk of cancer have had conflicting results. In addition, these studies ascertained participants either from treatment settings (ie, service-based studies) or by using a records linkage system (ie, medical records of patients evaluated at clinics or hospitals) and, therefore, were prone to selection bias. Our purpose was to estimate the risk of cancer mortality in a large population-based sample of elderly people, comparing participants with symptomatic atherosclerotic disease (atherosclerotic stroke and coronary disease) to their counterparts without symptomatic atherosclerotic disease (ie, controls) in the same population. In this population-based, prospective study (Neurological Disorders of Central Spain, NEDICES), 5262 elderly community-dwelling participants with and without symptomatic atherosclerotic disease were identified and followed for a median of 12.1 years, after which the death certificates of those who died were reviewed. A total of 2701 (53.3%) of 5262 participants died, including 314 (68.6%) of 458 participants with symptomatic atherosclerotic disease and 2387 (49.7%) of 4804 controls. Cancer mortality was reported significantly less often in those with symptomatic atherosclerotic disease (15.6%) than in controls (25.6%) (P < 0.001). In an unadjusted Cox model, risk of cancer-specific mortality was decreased in participants with symptomatic atherosclerotic disease (HR = 0.74, 95% confidence interval [CI], 0.55−0.98, P = 0.04) vs. those without symptomatic atherosclerotic disease (reference group). In an adjusted Cox model, HR = 0.58; 95% CI, 0.38−0.89; P = 0.01. This population-based, prospective study suggests that there is an inverse association between symptomatic atherosclerotic disease and risk of cancer mortality. PMID:26266364

  10. Graphics processing unit-accelerated non-rigid registration of MR images to CT images during CT-guided percutaneous liver tumor ablations

    PubMed Central

    Tokuda, Junichi; Plishker, William; Torabi, Meysam; Olubiyi, Olutayo I; Zaki, George; Tatli, Servet; Silverman, Stuart G.; Shekhar, Raj; Hata, Nobuhiko

    2015-01-01

    Rationale and Objectives Accuracy and speed are essential for the intraprocedural nonrigid MR-to-CT image registration in the assessment of tumor margins during CT-guided liver tumor ablations. While both accuracy and speed can be improved by limiting the registration to a region of interest (ROI), manual contouring of the ROI prolongs the registration process substantially. To achieve accurate and fast registration without the use of an ROI, we combined a nonrigid registration technique based on volume subdivision with hardware acceleration using a graphical processing unit (GPU). We compared the registration accuracy and processing time of GPU-accelerated volume subdivision-based nonrigid registration technique to the conventional nonrigid B-spline registration technique. Materials and Methods Fourteen image data sets of preprocedural MR and intraprocedural CT images for percutaneous CT-guided liver tumor ablations were obtained. Each set of images was registered using the GPU-accelerated volume subdivision technique and the B-spline technique. Manual contouring of ROI was used only for the B-spline technique. Registration accuracies (Dice Similarity Coefficient (DSC) and 95% Hausdorff Distance (HD)), and total processing time including contouring of ROIs and computation were compared using a paired Student’s t-test. Results Accuracy of the GPU-accelerated registrations and B-spline registrations, respectively were 88.3 ± 3.7% vs 89.3 ± 4.9% (p = 0.41) for DSC and 13.1 ± 5.2 mm vs 11.4 ± 6.3 mm (p = 0.15) for HD. Total processing time of the GPU-accelerated registration and B-spline registration techniques was 88 ± 14 s vs 557 ± 116 s (p < 0.000000002), respectively; there was no significant difference in computation time despite the difference in the complexity of the algorithms (p = 0.71). Conclusion The GPU-accelerated volume subdivision technique was as accurate as the B-spline technique and required significantly less processing time. The GPU-accelerated

  11. Effect of the drying process on the intensification of phenolic compounds recovery from grape pomace using accelerated solvent extraction.

    PubMed

    Rajha, Hiba N; Ziegler, Walter; Louka, Nicolas; Hobaika, Zeina; Vorobiev, Eugene; Boechzelt, Herbert G; Maroun, Richard G

    2014-01-01

    In light of their environmental and economic interests, food byproducts have been increasingly exploited and valorized for their richness in dietary fibers and antioxidants. Phenolic compounds are antioxidant bioactive molecules highly present in grape byproducts. Herein, the accelerated solvent extraction (ASE) of phenolic compounds from wet and dried grape pomace, at 45 °C, was conducted and the highest phenolic compounds yield (PCY) for wet (16.2 g GAE/100 g DM) and dry (7.28 g GAE/100 g DM) grape pomace extracts were obtained with 70% ethanol/water solvent at 140 °C. The PCY obtained from wet pomace was up to two times better compared to the dry byproduct and up to 15 times better compared to the same food matrices treated with conventional methods. With regard to Resveratrol, the corresponding dry pomace extract had a better free radical scavenging activity (49.12%) than the wet extract (39.8%). The drying pretreatment process seems to ameliorate the antiradical activity, especially when the extraction by ASE is performed at temperatures above 100 °C. HPLC-DAD analysis showed that the diversity of the flavonoid and the non-flavonoid compounds found in the extracts was seriously affected by the extraction temperature and the pretreatment of the raw material. This diversity seems to play a key role in the scavenging activity demonstrated by the extracts. Our results emphasize on ASE usage as a promising method for the preparation of highly concentrated and bioactive phenolic extracts that could be used in several industrial applications.

  12. Effect of the Drying Process on the Intensification of Phenolic Compounds Recovery from Grape Pomace Using Accelerated Solvent Extraction

    PubMed Central

    Rajha, Hiba N.; Ziegler, Walter; Louka, Nicolas; Hobaika, Zeina; Vorobiev, Eugene; Boechzelt, Herbert G.; Maroun, Richard G.

    2014-01-01

    In light of their environmental and economic interests, food byproducts have been increasingly exploited and valorized for their richness in dietary fibers and antioxidants. Phenolic compounds are antioxidant bioactive molecules highly present in grape byproducts. Herein, the accelerated solvent extraction (ASE) of phenolic compounds from wet and dried grape pomace, at 45 °C, was conducted and the highest phenolic compounds yield (PCY) for wet (16.2 g GAE/100 g DM) and dry (7.28 g GAE/100 g DM) grape pomace extracts were obtained with 70% ethanol/water solvent at 140 °C. The PCY obtained from wet pomace was up to two times better compared to the dry byproduct and up to 15 times better compared to the same food matrices treated with conventional methods. With regard to Resveratrol, the corresponding dry pomace extract had a better free radical scavenging activity (49.12%) than the wet extract (39.8%). The drying pretreatment process seems to ameliorate the antiradical activity, especially when the extraction by ASE is performed at temperatures above 100 °C. HPLC-DAD analysis showed that the diversity of the flavonoid and the non-flavonoid compounds found in the extracts was seriously affected by the extraction temperature and the pretreatment of the raw material. This diversity seems to play a key role in the scavenging activity demonstrated by the extracts. Our results emphasize on ASE usage as a promising method for the preparation of highly concentrated and bioactive phenolic extracts that could be used in several industrial applications. PMID:25322155

  13. Accelerated aging studies of UHMWPE. I. Effect of resin, processing, and radiation environment on resistance to mechanical degradation.

    PubMed

    Edidin, A A; Herr, M P; Villarraga, M L; Muth, J; Yau, S S; Kurtz, S M

    2002-08-01

    The resin and processing route have been identified as potential variables influencing the mechanical behavior, and hence the clinical performance, of ultra-high molecular weight polyethylene (UHMWPE) orthopedic components. Researchers have reported that components fabricated from 1900 resin may oxidize to a lesser extent than components fabricated from GUR resin during shelf aging after gamma sterilization in air. Conflicting reports on the oxidation resistance for 1900 raise the question of whether resin or manufacturing method, or an interaction between resin and manufacturing method, influences the mechanical behavior of UHMWPE. We conducted a series of accelerated aging studies (no aging, aging in oxygen or in nitrogen) to systematically examine the influence of resin (GUR or 1900), manufacturing method (bulk compression molding or extrusion), and sterilization method (none, in air, or in nitrogen) on the mechanical behavior of UHMWPE. The small punch testing technique was used to evaluate the mechanical behavior of the materials, and Fourier transform infrared spectroscopy was used to characterize the oxidation in selected samples. Our study showed that the sterilization environment, aging condition, and specimen location (surface or subsurface) significantly affected the mechanical behavior of UHMWPE. Each of the three polyethylenes evaluated seem to degrade according to a similar pathway after artificial aging in oxygen and gamma irradiation in air. The initial ability of the materials to exhibit post-yield strain hardening was significantly compromised by degradation. In general, there were only minor differences in the aging behavior of molded and extruded GUR 1050, whereas the molded 1900 material seemed to degrade slightly faster than either of the 1050 materials.

  14. Laser capture microdissection for analysis of macrophage gene expression from atherosclerotic lesions.

    PubMed

    Feig, Jonathan E; Fisher, Edward A

    2013-01-01

    Coronary artery disease, resulting from atherosclerosis, is the leading cause of death in the Western world. Most previous studies have subjected atherosclerotic arteries, a tissue of mixed cellular composition, to homogenization in order to identify the factors in plaque development, thereby obscuring information relevant to specific cell types. Because macrophage foam cells are critical mediators in atherosclerotic plaque advancement, we reasoned that performing gene analysis on those cells would provide specific insight in novel regulatory factors and potential therapeutic targets. We demonstrated for the first time in vascular biology that foam cell-specific RNA can be isolated by laser capture microdissection (LCM) of plaques. As expected, compared to whole tissue, a significant enrichment in foam cell-specific RNA transcripts was observed. Furthermore, because regression of atherosclerosis is a tantalizing clinical goal, we developed and reported a transplantation-based mouse model. This involved allowing plaques to form in apoE-/- mice and then changing the plaque's plasma environment from hyperlipidemia to normolipidemia. Under those conditions, rapid regression ensued in a process involving emigration of plaque foam cells to regional and systemic lymph nodes. Using LCM, we were able to show that under regression conditions, there was decreased expression in foam cells of inflammatory genes, but an up-regulation of cholesterol efflux genes. Interestingly, we also found that increased expression of chemokine receptor CCR7, a known factor in dendritic cell migration, was required for regression. In conclusion, the LCM methods described in this chapter, which have already lead to a number of striking findings, will likely further facilitate the study of cell type-specific gene expression in animal and human plaques during various stages of atherosclerosis, and after genetic, pharmacologic, and environmental perturbations.

  15. Stenting and Medical Therapy for Atherosclerotic Renal-Artery Stenosis

    PubMed Central

    Cooper, Christopher J.; Murphy, Timothy P.; Cutlip, Donald E.; Jamerson, Kenneth; Henrich, William; Reid, Diane M.; Cohen, David J.; Matsumoto, Alan H.; Steffes, Michael; Jaff, Michael R.; Prince, Martin R.; Lewis, Eldrin F.; Tuttle, Katherine R.; Shapiro, Joseph I.; Rundback, John H.; Massaro, Joseph M.; D'Agostino, Ralph B.; Dworkin, Lance D.

    2016-01-01

    BACKGROUND Atherosclerotic renal-artery stenosis is a common problem in the elderly. Despite two randomized trials that did not show a benefit of renal-artery stenting with respect to kidney function, the usefulness of stenting for the prevention of major adverse renal and cardiovascular events is uncertain. METHODS We randomly assigned 947 participants who had atherosclerotic renal-artery stenosis and either systolic hypertension while taking two or more antihypertensive drugs or chronic kidney disease to medical therapy plus renal-artery stenting or medical therapy alone. Participants were followed for the occurrence of adverse cardiovascular and renal events (a composite end point of death from cardiovascular or renal causes, myocar-dial infarction, stroke, hospitalization for congestive heart failure, progressive renal insufficiency, or the need for renal-replacement therapy). RESULTS Over a median follow-up period of 43 months (interquartile range, 31 to 55), the rate of the primary composite end point did not differ significantly between participants who underwent stenting in addition to receiving medical therapy and those who received medical therapy alone (35.1% and 35.8%, respectively; hazard ratio with stenting, 0.94; 95% confidence interval [CI], 0.76 to 1.17; P = 0.58). There were also no significant differences between the treatment groups in the rates of the individual components of the primary end point or in all-cause mortality. During follow-up, there was a consistent modest difference in systolic blood pressure favoring the stent group (−2.3 mm Hg; 95% CI, −4.4 to −0.2; P = 0.03). CONCLUSIONS Renal-artery stenting did not confer a significant benefit with respect to the prevention of clinical events when added to comprehensive, multifactorial medical therapy in people with atherosclerotic renal-artery stenosis and hypertension or chronic kidney disease. (Funded by the National Heart, Lung and Blood Institute and others; Clinical

  16. Radioiodine Therapy Does Not Change the Atherosclerotic Burden of the Carotid Arteries

    PubMed Central

    Andersen, Ulrik Bjørn; Sørensen, Christian Hjort; Nygaard, Birte; Jensen, Lars Thorbjørn

    2016-01-01

    Background and aim: Atherosclerosis evolves or accelerates when arteries are exposed to ionizing radiation, both early and late after exposure. Radioiodine therapy of benign thyroid disease exposes the carotid arteries to 4–50 Gy, and may thereby increase the risk of atherosclerosis. Increased risk of cerebrovascular events has been reported after radioiodine therapy. This study aimed to examine whether atherosclerosis develops early or late after radioiodine therapy of benign thyroid disease. Method: Patients treated for benign thyroid disorders (nontoxic goiter, adenoma, and hyperthyroidism) were examined with ultrasound for the main outcome, carotid intima media thickness (CIMT), and for plaque presence (plaque presence only in late damage). Signs of early damage from radioiodine were studied in 39 radioiodine-treated patients, who were examined before treatment and at 1, 3, 6, and 12 months after treatment. Late changes were studied in a cross-sectional case-control design, with radioiodine-treated patients as cases (n = 193) and patients treated with surgery as controls (n = 95). Data were analyzed with repeated measurement for longitudinal data, and with multivariate regression for cross-sectional data. Results were adjusted for age, sex, cholesterol, smoking status, known atherosclerotic disease, and body mass index. Results: No changes in CIMT were found in the patients followed prospectively for one year after treatment with radioactive iodine for benign thyroid disease (p = 0.58). In the study on late effects, there was no difference in CIMT (p = 0.25) or presence of plaques (p = 0.70) between those treated with radioactive iodine and those treated with surgery (9.8 and 5.6 years since treatment, respectively). Furthermore, the level of thyrotropin (TSH) did not influence these atherosclerosis markers. Conclusion: No early changes in CIMT were detected in patients treated with radioactive iodine for benign thyroid disease. No signs

  17. Anti-Atherosclerotic Effects of a Phytoestrogen-Rich Herbal Preparation in Postmenopausal Women

    PubMed Central

    Myasoedova, Veronika A.; Kirichenko, Tatyana V.; Melnichenko, Alexandra A.; Orekhova, Varvara A.; Ravani, Alessio; Poggio, Paolo; Sobenin, Igor A.; Bobryshev, Yuri V.; Orekhov, Alexander N.

    2016-01-01

    The risk of cardiovascular disease and atherosclerosis progression is significantly increased after menopause, probably due to the decrease of estrogen levels. The use of hormone replacement therapy (HRT) for prevention of cardiovascular disease in older postmenopausal failed to meet expectations. Phytoestrogens may induce some improvements in climacteric symptoms, but their effect on the progression of atherosclerosis remains unclear. The reduction of cholesterol accumulation at the cellular level should lead to inhibition of the atherosclerotic process in the arterial wall. The inhibition of intracellular lipid deposition with isoflavonoids was suggested as the effective way for the prevention of plaque formation in the arterial wall. The aim of this double-blind, placebo-controlled clinical study was to investigate the effect of an isoflavonoid-rich herbal preparation on atherosclerosis progression in postmenopausal women free of overt cardiovascular disease. One hundred fifty-seven healthy postmenopausal women (age 65 ± 6) were randomized to a 500 mg isoflavonoid-rich herbal preparation containing tannins from grape seeds, green tea leaves, hop cone powder, and garlic powder, or placebo. Conventional cardiovascular risk factors and intima-media thickness of common carotid arteries (cIMT) were evaluated at the baseline and after 12 months of treatment. After 12-months follow-up, total cholesterol decreased by 6.3% in isoflavonoid-rich herbal preparation recipients (p = 0.011) and by 5.2% in placebo recipients (p = 0.020); low density lipoprotein (LDL) cholesterol decreased by 7.6% in isoflavonoid-rich herbal preparation recipients (p = 0.040) and by 5.2% in placebo recipients (non-significant, NS); high density lipoprotein (HDL) cholesterol decreased by 3.4% in isoflavonoid-rich herbal preparation recipients (NS) and by 4.5% in placebo recipients (p = 0.038); triglycerides decreased by 6.0% in isoflavonoid-rich herbal preparation recipients (NS) and by 7.1% in

  18. Anti-Atherosclerotic Effects of a Phytoestrogen-Rich Herbal Preparation in Postmenopausal Women.

    PubMed

    Myasoedova, Veronika A; Kirichenko, Tatyana V; Melnichenko, Alexandra A; Orekhova, Varvara A; Ravani, Alessio; Poggio, Paolo; Sobenin, Igor A; Bobryshev, Yuri V; Orekhov, Alexander N

    2016-01-01

    The risk of cardiovascular disease and atherosclerosis progression is significantly increased after menopause, probably due to the decrease of estrogen levels. The use of hormone replacement therapy (HRT) for prevention of cardiovascular disease in older postmenopausal failed to meet expectations. Phytoestrogens may induce some improvements in climacteric symptoms, but their effect on the progression of atherosclerosis remains unclear. The reduction of cholesterol accumulation at the cellular level should lead to inhibition of the atherosclerotic process in the arterial wall. The inhibition of intracellular lipid deposition with isoflavonoids was suggested as the effective way for the prevention of plaque formation in the arterial wall. The aim of this double-blind, placebo-controlled clinical study was to investigate the effect of an isoflavonoid-rich herbal preparation on atherosclerosis progression in postmenopausal women free of overt cardiovascular disease. One hundred fifty-seven healthy postmenopausal women (age 65 ± 6) were randomized to a 500 mg isoflavonoid-rich herbal preparation containing tannins from grape seeds, green tea leaves, hop cone powder, and garlic powder, or placebo. Conventional cardiovascular risk factors and intima-media thickness of common carotid arteries (cIMT) were evaluated at the baseline and after 12 months of treatment. After 12-months follow-up, total cholesterol decreased by 6.3% in isoflavonoid-rich herbal preparation recipients (p = 0.011) and by 5.2% in placebo recipients (p = 0.020); low density lipoprotein (LDL) cholesterol decreased by 7.6% in isoflavonoid-rich herbal preparation recipients (p = 0.040) and by 5.2% in placebo recipients (non-significant, NS); high density lipoprotein (HDL) cholesterol decreased by 3.4% in isoflavonoid-rich herbal preparation recipients (NS) and by 4.5% in placebo recipients (p = 0.038); triglycerides decreased by 6.0% in isoflavonoid-rich herbal preparation recipients (NS) and by 7.1% in

  19. Laser ablation of human atherosclerotic plaque without adjacent tissue injury

    NASA Technical Reports Server (NTRS)

    Grundfest, W. S.; Litvack, F.; Forrester, J. S.; Goldenberg, T.; Swan, H. J. C.

    1985-01-01

    Seventy samples of human cadaver atherosclerotic aorta were irradiated in vitro using a 308 nm xenon chloride excimer laser. Energy per pulse, pulse duration and frequency were varied. For comparison, 60 segments were also irradiated with an argon ion and an Nd:YAG laser operated in the continuous mode. Tissue was fixed in formalin, sectioned and examined microscopically. The Nd:YAG and argon ion-irradiated tissue exhibited a central crater with irregular edges and concentric zones of thermal and blast injury. In contrast, the excimer laser-irradiated tissue had narrow deep incisions with minimal or no thermal injury. These preliminary experiments indicate that the excimer laser vaporizes tissue in a manner different from that of the continuous wave Nd:YAG or argon ion laser. The sharp incision margins and minimal damage to adjacent normal tissue suggest that the excimer laser is more desirable for general surgical and intravascular uses than are the conventionally used medical lasers.

  20. Lipid and protein maps defining arterial layers in atherosclerotic aorta.

    PubMed

    Martin-Lorenzo, Marta; Balluff, Benjamin; Maroto, Aroa S; Carreira, Ricardo J; van Zeijl, Rene J M; Gonzalez-Calero, Laura; de la Cuesta, Fernando; Barderas, Maria G; Lopez-Almodovar, Luis F; Padial, Luis R; McDonnell, Liam A; Vivanco, Fernando; Alvarez-Llamas, Gloria

    2015-09-01

    Subclinical atherosclerosis cannot be predicted and novel therapeutic targets are needed. The molecular anatomy of healthy and atherosclerotic tissue is pursued to identify ongoing molecular changes in atherosclerosis development. Mass Spectrometry Imaging (MSI) accounts with the unique advantage of analyzing proteins and metabolites (lipids) while preserving their original localization; thus two dimensional maps can be obtained. Main molecular alterations were investigated in a rabbit model in response to early development of atherosclerosis. Aortic arterial layers (intima and media) and calcified regions were investigated in detail by MALDI-MSI and proteins and lipids specifically defining those areas of interest were identified. These data further complement main findings previously published in J Proteomics (M. Martin-Lorenzo et al., J. Proteomics. (In press); M. Martin-Lorenzo et al., J. Proteomics 108 (2014) 465-468.) [1,2]. PMID:26217810

  1. Evaluation and percutaneous management of atherosclerotic peripheral vascular disease

    SciTech Connect

    Widlus, D.M.; Osterman, F.A. Jr. )

    1989-06-02

    Atherosclerotic peripheral vascular disease (PVD) of the lower extremities deprives a person of the ability to exercise to their satisfaction, later of the ability to perform the activities of their daily life, and finally of their legs themselves. Peripheral vascular disease has long been managed by the vascular surgeon utilizing endarterectomy and peripheral arterial bypass. Patient acceptance of nonsurgical, percutaneous procedures such as percutaneous transluminal balloon angioplasty (PTA) is high. Increased utilization of these procedures has led to improved techniques and adjuncts to therapy, as well as more critical review of long-term results. This article will review the evaluation and nonoperative management of PVD, with an emphasis on the newer modalities of management presently being investigated.

  2. Zooming in on the genesis of atherosclerotic plaque microcalcifications.

    PubMed

    Ruiz, Jessica L; Weinbaum, Sheldon; Aikawa, Elena; Hutcheson, Joshua D

    2016-06-01

    Epidemiological evidence conclusively demonstrates that calcium burden is a significant predictor of cardiovascular morbidity and mortality; however, the underlying mechanisms remain largely unknown. These observations have challenged the previously held notion that calcification serves to stabilize the atherosclerotic plaque. Recent studies have shown that microcalcifications that form within the fibrous cap of the plaques lead to the accrual of plaque-destabilizing mechanical stress. Given the association between calcification morphology and cardiovascular outcomes, it is important to understand the mechanisms leading to calcific mineral deposition and growth from the earliest stages. We highlight the open questions in the field of cardiovascular calcification and include a review of the proposed mechanisms involved in extracellular vesicle-mediated mineral deposition. PMID:27040360

  3. Low dose tunicamycin enhances atherosclerotic plaque stability by inducing autophagy.

    PubMed

    Ma, Meijuan; Song, Liqiang; Yan, Hao; Liu, Min; Zhang, Le; Ma, Ying; Yuan, Jian; Hu, Jianhua; Ji, Zhaole; Zhang, Rongqing; Li, Congye; Wang, Haichang; Tao, Ling; Zhang, Yingmei; Li, Yan

    2016-01-15

    After decades of indolent progression, atherosclerosis may cause unheralded events, such as myocardial infarction, acute coronary syndrome and stroke due to sudden rupture of atherosclerotic plaques, and pharmacologically modulating plaque stability would reduce the risk of cardiovascular diseases. Endoplasmic reticulum stress (ERS) is responsible for the vulnerability of plaques. However, the underlying mechanism has not been fully elucidated. In this work, ApoE(-/-) mice underwent perivascular carotid collar placement surgeries or sham operations were given higher (3.0mg/kg) and lower (0.3mg/kg) doses of tunicamycin (TM), and plaque stability was evaluated. It was shown that lower TM-treated animals exhibited reduced plaque areas and necrotic cores as well as fibrous cap thickness accompanied by a lower percentage of infiltrates and foam cells than the sham-operated and higher TM treated animals. Lower TM had a profound inhibitory effect on plasma inflammatory response and lipid profile in atherosclerotic ApoE(-/-) mice. In addition, we found that the ApoE(-/-) mice presented higher autophagy activity in response to lower TM administration while apoptosis was reduced. An in vitro study in murine macrophages revealed that lower TM could markedly reduce lipid uptake and accumulation and cell apoptosis while significantly upregulated the expression of Atg7. However, higher TM had adverse effects. Finally, mild induction of ERS by lower TM inhibits AKT-TSC-mTOR cascades to increase cellular autophagy. However, high TM failed to enhance autophagy and equilibrate elevated CHOP-mediated cell death in spite of the inhibition of AKT-TSC-mTOR signaling. In conclusion, lower TM stabilized plaques by activating autophagy through AKT-TSC-mTOR signaling. PMID:26616221

  4. Low dose tunicamycin enhances atherosclerotic plaque stability by inducing autophagy.

    PubMed

    Ma, Meijuan; Song, Liqiang; Yan, Hao; Liu, Min; Zhang, Le; Ma, Ying; Yuan, Jian; Hu, Jianhua; Ji, Zhaole; Zhang, Rongqing; Li, Congye; Wang, Haichang; Tao, Ling; Zhang, Yingmei; Li, Yan

    2016-01-15

    After decades of indolent progression, atherosclerosis may cause unheralded events, such as myocardial infarction, acute coronary syndrome and stroke due to sudden rupture of atherosclerotic plaques, and pharmacologically modulating plaque stability would reduce the risk of cardiovascular diseases. Endoplasmic reticulum stress (ERS) is responsible for the vulnerability of plaques. However, the underlying mechanism has not been fully elucidated. In this work, ApoE(-/-) mice underwent perivascular carotid collar placement surgeries or sham operations were given higher (3.0mg/kg) and lower (0.3mg/kg) doses of tunicamycin (TM), and plaque stability was evaluated. It was shown that lower TM-treated animals exhibited reduced plaque areas and necrotic cores as well as fibrous cap thickness accompanied by a lower percentage of infiltrates and foam cells than the sham-operated and higher TM treated animals. Lower TM had a profound inhibitory effect on plasma inflammatory response and lipid profile in atherosclerotic ApoE(-/-) mice. In addition, we found that the ApoE(-/-) mice presented higher autophagy activity in response to lower TM administration while apoptosis was reduced. An in vitro study in murine macrophages revealed that lower TM could markedly reduce lipid uptake and accumulation and cell apoptosis while significantly upregulated the expression of Atg7. However, higher TM had adverse effects. Finally, mild induction of ERS by lower TM inhibits AKT-TSC-mTOR cascades to increase cellular autophagy. However, high TM failed to enhance autophagy and equilibrate elevated CHOP-mediated cell death in spite of the inhibition of AKT-TSC-mTOR signaling. In conclusion, lower TM stabilized plaques by activating autophagy through AKT-TSC-mTOR signaling.

  5. Antibody-Labeled Liposomes for CT Imaging of Atherosclerotic Plaques

    PubMed Central

    Danila, Delia; Partha, Ranga; Elrod, Don B.; Lackey, Melinda; Casscells, S. Ward; Conyers, Jodie L.

    2009-01-01

    We evaluated the specific binding of anti-intercellular adhesion molecule 1 (ICAM-1) conjugated liposomes (immunoliposomes, or ILs) to activated human coronary artery endothelial cells (HCAEC) with the purpose of designing a computed tomographic imaging agent for early detection of atherosclerotic plaques. Covalent attachment of anti-ICAM-1 monoclonal antibodies to pre-formed liposomes stabilized with polyethylene glycol yielded ILs, with a coupling efficiency of the ICAM-1 to the liposomes of 10% to 24%. The anti-ICAM-1–labeled ILs had an average diameter of 136 nm as determined by dynamic light-scattering and cryogenic electron microscopy. The ILs' encapsulation of 5-[N-acetyl-(2,3-dihydroxypropyl)-amino)-N, N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-benzene-1,3-dicarboxamide (iohexol) was determined to be 18% to 19% by a dialysis technique coupled with ultraviolet detection of free iohexol. This encapsulation corresponded to 30 to 38 mg iodine per mL IL solution, and the ILs exhibited 91% to 98.5% iohexol retention at room temperature and under physiologic conditions. The specific binding of the ILs to cultured, activated HCAEC was measured using flow cytometry, enzyme-linked immunosorbent assays, and fluorescence microscopy. The immunosorbent assays demonstrated the specificity of binding of anti-ICAM-1 to ICAM-1 compared with control studies using nonspecific immunoglobulin G-labeled ILs. Flow cytometry and fluorescence microscopy experiments demonstrated the expression of ICAM-1 on the surface of activated HCAEC. Therefore, our iohexol-filled ILs demonstrated potential for implementation in computed tomographic angiography to noninvasively detect atherosclerotic plaques that are prone to rupture. PMID:19876414

  6. Abdominal Aortic Disease Caused by Penetrating Atherosclerotic Ulcers

    PubMed Central

    Sato, Masataka; Imai, Akito; Sakamoto, Hiroaki; Sasaki, Akinobu; Watanabe, Yasunori; Jikuya,, Tomoaki

    2012-01-01

    Objective: Penetrating atherosclerotic ulcer (PAU) of the aorta is defined as an atherosclerotic lesion with ulceration of the aortic intima and media and rupture of the internal elastic lamina. PAU induced aortic dissection, aortic rupture, and secular aortic aneurysm and typically occurs in elderly hypertensive patients with severe atherosclerosis. Although it has been reported that atherosclerosis similarly occurs in the abdominal aorta, its natural history and treatment are still unclear. This study investigated the clinical features, natural history, and treatment of PAU of the abdominal aorta. Method:Between April 2006 and March 2009, 4 diagnoses of PAU in the abdominal aorta were made by computed tomography (CT) and magnetic resonance imaging (MRI). These 4 cases were analyzed along with 61 previously reported cases from the literature with diagnoses of PAU in the abdominal aorta, aortic rupture, and isolated abdominal aortic dissection over the past 15 years, giving a total of 65 cases. Results:The patients were men with an average age of 63.5 years. All 4 had hypertension, and 2 had concomitant coronary artery disease. Two patients were asymptomatic, and the other 2 were symptomatic and transmural rupture had occurred. All diagnoses were made by CT and MRI. All 4 patients underwent open surgery with a knitted Dacron graft, with no postoperative deaths. In the literature, 53% of cases were symptomatic, including pain (40%, n = 26), shock (4.6%, n = 3), and lower limb embolism (9.2%, n = 6). The remaining 40% of cases were asymptomatic (n = 26). Six patients were treated medically, while 58 patients underwent surgery, with 2 postoperative deaths. Conclusion:We suggest that surgical treatment (open surgery or endovascular stent grafting) should be performed to prevent an aortic catastrophe such as intramural hematoma, dissection, or rupture. (English translation of Jpn J Vasc Surg 2010; 19: 723-730.) PMID:23555480

  7. TRAIL-deficiency accelerates vascular calcification in atherosclerosis via modulation of RANKL.

    PubMed

    Di Bartolo, Belinda A; Cartland, Siân P; Harith, Hanis H; Bobryshev, Yuri V; Schoppet, Michael; Kavurma, Mary M

    2013-01-01

    The osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) cytokine system, not only controls bone homeostasis, but has been implicated in regulating vascular calcification. TNF-related apoptosis-inducing ligand (TRAIL) is a second ligand for OPG, and although its effect in vascular calcification in vitro is controversial, its role in vivo is not yet established. This study aimed to investigate the role of TRAIL in vascular calcification in vitro using vascular smooth muscle cells (VSMCs) isolated from TRAIL(-/-) and wild-type mice, as well as in vivo, in advanced atherosclerotic lesions of TRAIL(-/-)ApoE(-/-) mice. The involvement of OPG and RANKL in this process was also examined. TRAIL dose-dependently inhibited calcium-induced calcification of human VSMCs, while TRAIL(-/-) VSMCs demonstrated accelerated calcification induced by multiple concentrations of calcium compared to wild-type cells. Consistent with this, RANKL mRNA was significantly elevated with 24 h calcium treatment, while OPG and TRAIL expression in human VSMCs was inhibited. Brachiocephalic arteries from TRAIL(-/-)ApoE(-/-) and ApoE(-/-) mice fed a high fat diet for 12 w demonstrated increased chondrocyte-like cells in atherosclerotic plaque, as well as increased aortic collagen II mRNA expression in TRAIL(-/-)ApoE(-/-) mice, with significant increases in calcification observed at 20 w. TRAIL(-/-)ApoE(-/-) aortas also had significantly elevated RANKL, BMP-2, IL-1β, and PPAR-γ expression at 12 w. Our data provides the first evidence that TRAIL deficiency results in accelerated cartilaginous metaplasia and calcification in atherosclerosis, and that TRAIL plays an important role in the regulation of RANKL and inflammatory markers mediating bone turn over in the vasculature. PMID:24040204

  8. Future accelerators (?)

    SciTech Connect

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  9. [Clinical study of prejudicing autochthonous speech act (thought)--acceleration of the activity in the remission process of schizophrenia].

    PubMed

    Kato, S

    1997-01-01

    phenomenon is considered to have a selfhealing effect. Prejudicing autochthonous speech act (thought), presents not only a certain disappearance process of auditory hallucinations, but also a kind of acceleration of the patient's activity in the preremission period which leads to a remission. Prejudicing autochthonous speech act (thought) should be therefore considered in the therapy of schizophrenics.

  10. Toward an understanding of the acceleration of Diels-Alder reactions by a pseudo-intramolecular process achieved by molecular recognition. A DFT study.

    PubMed

    Domingo, Luis R; Aurell, M José; Arnó, Manuel; Saez, José A

    2007-05-25

    The pseudo-intramolecular Diels-Alder (DA) reaction between a 2-substituted furan (1) and a N-maleimide derivative (2) has been analyzed using DFT methods. Formation of two hydrogen bonds between the appendages on furan and maleimide derivatives favors thermodynamically the formation of a molecular complex (MC1) through an efficient molecular recognition process. The large enthalpy stabilization associated with the molecular recognition overcomes the unfavorable activation entropy associated with the bimolecular process. As a consequence, the subsequent DA reaction is clearly accelerated through a pseudo-intramolecular process.

  11. Nonlinear processes in cosmic-ray precursor of strong supernova shock: Maximum energy and average energy spectrum of accelerated particles

    NASA Astrophysics Data System (ADS)

    Ptuskin, V. S.; Zirakashvili, V. N.

    The instability in the cosmic-ray precursor of a supernova shock is studied. The level of turbulence in this region determines the maximum energy of accelerated particles. The consideration is not limited by the case of weak turbulence. It is assumed that the Kolmogorov type nonlinear wave interactions together with the ion-neutral collisions restrict the amplitude of random magnetic field. As a result, the maximum energy of accelerated particles strongly depends on the age of a SNR. The average spectrum of cosmic rays injected in the interstellar medium in the course of adiabatic SNR evolution takes the approximate form E-2 at energies larger than 10 30 GeV/nucleon with the maximum energy that is close to the position of the knee in cosmic-ray spectrum at 4 × 1015 eV. At an earlier stage of SNR evolution the ejecta-dominated stage, the particles are accelerated to higher energies and have a rather steep power-law distribution. These results suggest that the knee may mark the transition from the ejecta-dominated to the adiabatic evolution of SNR shocks which accelerate cosmic rays.

  12. Attenuation of atherosclerotic lesions in diabetic apolipoprotein E-deficient mice using gene silencing of macrophage migration inhibitory factor

    PubMed Central

    Sun, Hui; Zhang, XianJun; Zhao, Lei; Zhen, Xi; Huang, ShanYing; Wang, ShaSha; He, Hong; Liu, ZiMo; Xu, NaNa; Yang, FaLin; Qu, ZhongHua; Ma, ZhiYong; Zhang, Cheng; Zhang, Yun; Hu, Qin

    2015-01-01

    Macrophage migration inhibitory factor (MIF) involves the pathogenesis of atherosclerosis (AS) and increased plasma MIF levels in diabetes mellitus (DM) patients are associated with AS. Here, we have been suggested that MIF could be a critical contributor for the pathological process of diabetes-associated AS by using adenovirus-mediated RNA interference. First, streptozotocin (STZ)-induced diabetic animal model was constructed in 114 apolipoprotein E-deficient mice (apoE−/− mice) fed on a regular chow diet. Then, the animals were randomly divided into three groups: Adenovirus-mediated MIF interference (Ad-MIFi), Ad-enhanced green fluorescent protein (EGFP) and normal saline (NS) group (n ≈ 33/group). Non-diabetic apoE−/− mice (n = 35) were served as controls. Ad-MIFi, Ad-EGFP and NS were, respectively, injected into the tail vein of mice from Ad-MIFi, Ad-EGFP and NS group, which were injected repeatedly 4 weeks later. Physical, biochemical, morphological and molecular parameters were measured. The results showed that diabetic apoE−/− mice had significantly aggravated atherosclerotic lesions. MIF gene interference attenuated atherosclerotic lesions and stabilized atheromatous plaque, accompanied by the decreased macrophages and lipids deposition and inflammatory cytokines production, improved glucose intolerance and plasma cholesterol level, the decreased ratio of matrix matalloproteinase-2/tissue inhibitor of metalloproteinase-1 and plaque instability index. An increased expression of MIF and its ligand CD74 was also detected in the diabetic patients with coronary artery disease. The results suggest that MIF gene interference is able to inhibit atherosclerotic lesions and increase plaque stability in diabetic apoE−/−mice. MIF inhibition could be a novel and promising approach to the treatment of DM-associated AS. PMID:25661015

  13. Characterization of atherosclerotic plaque-depositions by infrared, Raman and CARS microscopy

    NASA Astrophysics Data System (ADS)

    Matthäus, Christian; Bergner, Gero; Krafft, Christoph; Dietzek, Benjamin; Romeike, Bernd F. M.; Brehm, Bernhard R.; Popp, Jürgen

    2011-07-01

    Atherosclerotic plaques are mainly composed of proteoglycans, triglycerides, cholesterol, cholesterolester and crystalline calcium. From histopathological characterizations it is known that the composition of these atherosclerotic plaques can vary to a great extent, due to different risk factors as smoking, hyperlipedemia, or genetic background ect. The individual plaque components can be spectroscopically easily identified. Furthermore, spectroscopic imaging technologies offer the possibility to study the plaque compositions in a more quantitative manner than traditional staining techniques. Here, we compare the potential of IR, Raman and CARS microscopy to characterize the constitution of atherosclerotic plaques as well as the structure of the surrounding tissue. For data analysis and image reconstruction spectral decomposition algorithms such as vertex component analysis (VCA) were introduced. The results are in good agreement with the histopathology. Aim of the study is to correlate the compositional characteristics of atherosclerotic plaques with individual disease patterns.

  14. Intravascular photoacoustic imaging of exogenously labeled atherosclerotic plaque through luminal blood

    PubMed Central

    Yeager, Doug; Karpiouk, Andrei; Wang, Bo; Amirian, James; Sokolov, Konstantin; Smalling, Richard

    2012-01-01

    Abstract. Combined intravascular ultrasound and intravascular photoacoustic (IVUS/IVPA) imaging has been previously established as a viable means for assessing atherosclerotic plaque morphological and compositional characteristics using both endogenous and exogenous contrast. In this study, IVUS/IVPA imaging of atherosclerotic rabbit aortas following systemic injection of gold nanorods (AUNRs) with peak absorbance within the tissue optical window is performed. Ex vivo imaging results reveal a high photoacoustic signal from localized AUNRs in regions with atherosclerotic plaques. Corresponding histological staining further confirms the preferential extravasation of AUNRs in atherosclerotic regions with compromised luminal endothelium and acute inflammation. The ability to detect AUNRs using combined IVUS and photoacoustic imaging in the presence of luminal saline and luminal blood is evaluated using both spectroscopic and single wavelength IVPA imaging techniques. Results demonstrate that AUNR detection within the arterial wall can be achieved using both methods, even in the case of imaging through luminal blood. PMID:23224013

  15. Atherosclerosis and Atheroma Plaque Rupture: Imaging Modalities in the Visualization of Vasa Vasorum and Atherosclerotic Plaques

    PubMed Central

    2014-01-01

    Invasive angiography has been widely accepted as the gold standard to diagnose cardiovascular pathologies. Despite its superior resolution of demonstrating atherosclerotic plaque in terms of degree of lumen stenosis, the morphological assessment for the plaque is insufficient for the analysis of plaque components, and therefore, unable to predict the risk status or vulnerability of atherosclerotic plaque. There is an increased body of evidence to show that the vasa vasorum play an important role in the initiation, progression, and complications of atherosclerotic plaque leading to major adverse cardiac events. This paper provides an overview of the evidence-based reviews of various imaging modalities with regard to their potential value for comprehensive characterization of the composition, burden, and neovascularization of atherosclerotic plaque. PMID:24688380

  16. N(omega)-(carboxymethyl)lysine depositions in human aortic heart valves: similarities with atherosclerotic blood vessels.

    PubMed

    Baidoshvili, Alexi; Niessen, Hans W M; Stooker, Wim; Huybregts, Rien A J M; Hack, C Erik; Rauwerda, Jan A; Meijer, Chris J L M; Eijsman, Leon; van Hinsbergh, Victor W M; Schalkwijk, Casper G

    2004-06-01

    Recent studies indicate a role of atherosclerosis-like changes involved in the pathogenesis of aortic valve stenosis. Interestingly, one of the major advanced glycation end products (AGEs), N(omega)-(carboxymethyl)lysine (CML) has been related to the process of atherosclerosis in blood vessels. In the present study, we have analyzed the presence of CML in degenerative altered aortic valves with atherosclerosis-like changes, and in degenerated mitral valves without atherosclerosis-like changes, derived from patients suffering from acute rheumatism during childhood. Degenerated and non-degenerated valves were derived from autopsy or obtained during cardiac surgery. The presence of CML was examined by immunohistochemistry. CML was found on the endothelium and fibroblasts in control aortic and mitral valves. Minor differences in CML staining were observed between control and degeneratively affected mitral valves. In contrast, in degenerated aortic valves, CML accumulation was found in macrophages and on calcification sites, comparable to that in atherosclerotic arteries, while the presence of CML staining on the endothelium and fibroblasts was significantly less as compared with control aortic valves. Our data support the hypothesis that the process of degeneration of aortic valves resembles that of atherosclerosis in blood vessels. They suggest that CML also plays a role in the process of atherosclerosis in aortic valves.

  17. Mucosal Administration of Collagen V Ameliorates the Atherosclerotic Plaque Burden by Inducing Interleukin 35-dependent Tolerance.

    PubMed

    Park, Arick C; Huang, Guorui; Jankowska-Gan, Ewa; Massoudi, Dawiyat; Kernien, John F; Vignali, Dario A; Sullivan, Jeremy A; Wilkes, David S; Burlingham, William J; Greenspan, Daniel S

    2016-02-12

    We have shown previously that collagen V (col(V)) autoimmunity is a consistent feature of atherosclerosis in human coronary artery disease and in the Apoe(-/-) mouse model. We have also shown sensitization of Apoe(-/-) mice with col(V) to markedly increase the atherosclerotic burden, providing evidence of a causative role for col(V) autoimmunity in atherosclerotic pathogenesis. Here we sought to determine whether induction of immune tolerance to col(V) might ameliorate atherosclerosis, providing further evidence for a causal role for col(V) autoimmunity in atherogenesis and providing insights into the potential for immunomodulatory therapeutic interventions. Mucosal inoculation successfully induced immune tolerance to col(V) with an accompanying reduction in plaque burden in Ldlr(-/-) mice on a high-cholesterol diet. The results therefore demonstrate that inoculation with col(V) can successfully ameliorate the atherosclerotic burden, suggesting novel approaches for therapeutic interventions. Surprisingly, tolerance and reduced atherosclerotic burden were both dependent on the recently described IL-35 and not on IL-10, the immunosuppressive cytokine usually studied in the context of induced tolerance and amelioration of atherosclerotic symptoms. In addition to the above, using recombinant protein fragments, we were able to localize two epitopes of the α1(V) chain involved in col(V) autoimmunity in atherosclerotic Ldlr(-/-) mice, suggesting future courses of experimentation for the characterization of such epitopes.

  18. Noninvasive diagnosis of ruptured peripheral atherosclerotic lesions and myocardial infarction by antibody profiling

    PubMed Central

    Cleutjens, Kitty B.J.M.; Faber, Birgit C.G.; Rousch, Mat; van Doorn, Ruben; Hackeng, Tilman M.; Vink, Cornelis; Geusens, Piet; ten Cate, Hugo; Waltenberger, Johannes; Tchaikovski, Vadim; Lobbes, Marc; Somers, Veerle; Sijbers, Anneke; Black, Darcey; Kitslaar, Peter J.E.H.M.; Daemen, Mat J.A.P.

    2008-01-01

    Novel biomarkers, such as circulating (auto)antibody signatures, may improve early detection and treatment of ruptured atherosclerotic lesions and accompanying cardiovascular events, such as myocardial infarction. Using a phage-display library derived from cDNAs preferentially expressed in ruptured peripheral human atherosclerotic plaques, we performed serological antigen selection to isolate displayed cDNA products specifically interacting with antibodies in sera from patients with proven ruptured peripheral atherosclerotic lesions. Two cDNA products were subsequently evaluated on a validation series of patients with peripheral atherosclerotic lesions, healthy controls, and patients with coronary artery disease at different stages. Our biomarker set was able to discriminate between patients with peripheral ruptured lesions and patients with peripheral stable plaques with 100% specificity and 76% sensitivity. Furthermore, 93% of patients with an acute myocardial infarction (AMI) tested positive for our biomarkers, whereas all patients with stable angina pectoris tested negative. Moreover, 90% of AMI patients who initially tested negative for troponin T, for which a positive result is known to indicate myocardial infarction, tested positive for our biomarkers upon hospital admission. In conclusion, antibody profiling constitutes a promising approach for noninvasive diagnosis of atherosclerotic lesions, because a positive serum response against a set of 2 cDNA products showed a strong association with the presence of ruptured peripheral atherosclerotic lesions and myocardial infarction. PMID:18654662

  19. Recombinant growth factor mixtures induce cell cycle progression and the upregulation of type I collagen in human skin fibroblasts, resulting in the acceleration of wound healing processes.

    PubMed

    Lee, Do Hyun; Choi, Kyung-Ha; Cho, Jae-We; Kim, So Young; Kwon, Tae Rin; Choi, Sun Young; Choi, Yoo Mi; Lee, Jay; Yoon, Ho Sang; Kim, Beom Joon

    2014-05-01

    Application of growth factor mixtures has been used for wound healing and anti-wrinkles agents. The aim of this study was to evaluate the effect of recombinant growth factor mixtures (RGFM) on the expression of cell cycle regulatory proteins, type I collagen, and wound healing processes of acute animal wound models. The results showed that RGFM induced increased rates of cell proliferation and cell migration of human skin fibroblasts (HSF). In addition, expression of cyclin D1, cyclin E, cyclin-dependent kinase (Cdk)4, and Cdk2 proteins was markedly increased with a growth factor mixtures treatment in fibroblasts. Expression of type I collagen was also increased in growth factor mixtures-treated HSF. Moreover, growth factor mixtures-induced the upregulation of type I collagen was associated with the activation of Smad2/3. In the animal model, RGFM-treated mice showed accelerated wound closure, with the closure rate increasing as early as on day 7, as well as re-epithelization and reduced inflammatory cell infiltration than phosphate-buffered saline (PBS)-treated mice. In conclusion, the results indicated that RGFM has the potential to accelerate wound healing through the upregulation of type I collagen, which is partly mediated by activation of Smad2/3-dependent signaling pathway as well as cell cycle progression in HSF. The topical application of growth factor mixtures to acute and chronic skin wound may accelerate the epithelization process through these molecular mechanisms.

  20. Insulin decreases atherosclerotic plaque burden and increases plaque stability via nitric oxide synthase in apolipoprotein E-null mice.

    PubMed

    Mori, Yusaku; Chiang, Simon; Bendeck, Michelle P; Giacca, Adria

    2016-08-01

    It has been argued whether insulin accelerates or prevents atherosclerosis. Although results from in vitro studies have been conflicting, recent in vivo mice studies demonstrated antiatherogenic effects of insulin. Insulin is a known activator of endothelial nitric oxide synthase (NOS), leading to increased production of NO, which has potent antiatherogenic effects. We aimed to examine the role of NOS in the protective effects of insulin against atherosclerosis. Male apolipoprotein E-null mice (8 wk old) fed a high-cholesterol diet (1.25% cholesterol) were assigned to the following 12-wk treatments: control, insulin (0.05 U/day via subcutaneous pellet), N(ω)-nitro-l-arginine methyl ester hydrochloride (l-NAME, via drinking water at 100 mg/l), and insulin plus l-NAME. Insulin reduced atherosclerotic plaque burden in the descending aorta by 42% compared with control (plaque area/aorta lumen area: control, 16.5 ± 1.9%; insulin, 9.6 ± 1.3%, P < 0.05). Although insulin did not decrease plaque burden in the aortic sinus, macrophage accumulation in the plaque was decreased by insulin. Furthermore, insulin increased smooth muscle actin and collagen content and decreased plaque necrosis, consistent with increased plaque stability. In addition, insulin treatment increased plasma NO levels, decreased inducible NOS staining, and tended to increase phosphorylated vasodilator-stimulated phosphoprotein staining in the plaques of the aortic sinus. All these effects of insulin were abolished by coadministration of l-NAME, whereas l-NAME alone showed no effect. Insulin also tended to increase phosphorylated endothelial NOS and total neuronal NOS staining, effects not modified by l-NAME. In conclusion, we demonstrate that insulin treatment decreases atherosclerotic plaque burden and increases plaque stability through NOS-dependent mechanisms. PMID:27221119

  1. Highly absorptive curcumin reduces serum atherosclerotic low-density lipoprotein levels in patients with mild COPD

    PubMed Central

    Funamoto, Masafumi; Sunagawa, Yoichi; Katanasaka, Yasufumi; Miyazaki, Yusuke; Imaizumi, Atsushi; Kakeya, Hideaki; Yamakage, Hajime; Satoh-Asahara, Noriko; Komiyama, Maki; Wada, Hiromichi; Hasegawa, Koji; Morimoto, Tatsuya

    2016-01-01

    Purpose COPD is mainly caused by tobacco smoking and is associated with a high frequency of coronary artery disease. There is growing recognition that the inflammation in COPD is not only confined to the lungs but also involves the systemic circulation and can impact nonpulmonary organs, including blood vessels. α1-antitrypsin–low-density lipoprotein (AT-LDL) complex is an oxidatively modified LDL that accelerates atherosclerosis. Curcumin, one of the best-investigated natural products, is a powerful antioxidant. However, the effects of curcumin on AT-LDL remain unknown. We hypothesized that Theracurmin®, a highly absorptive curcumin with improved bioavailability using a drug delivery system, ameliorates the inflammatory status in subjects with mild COPD. Patients and methods This is a randomized, double-blind, parallel-group study. Subjects with stages I–II COPD according to the Japanese Respiratory Society criteria were randomly assigned to receive 90 mg Theracurmin® or placebo twice a day for 24 weeks, and changes in inflammatory parameters were evaluated. Results There were no differences between the Theracurmin® and placebo groups in terms of age, male/female ratio, or body mass index in 39 evaluable subjects. The percent changes in blood pressure and hemoglobin A1c and LDL-cholesterol, triglyceride, or high-density lipoprotein-cholesterol levels after treatment were similar for the two groups. However, the percent change in the AT-LDL level was significantly (P=0.020) lower in the Theracurmin® group compared with the placebo group. Conclusion Theracurmin® reduced levels of atherosclerotic AT-LDL, which may lead to the prevention of future cardiovascular events in mild COPD subjects.

  2. Highly absorptive curcumin reduces serum atherosclerotic low-density lipoprotein levels in patients with mild COPD

    PubMed Central

    Funamoto, Masafumi; Sunagawa, Yoichi; Katanasaka, Yasufumi; Miyazaki, Yusuke; Imaizumi, Atsushi; Kakeya, Hideaki; Yamakage, Hajime; Satoh-Asahara, Noriko; Komiyama, Maki; Wada, Hiromichi; Hasegawa, Koji; Morimoto, Tatsuya

    2016-01-01

    Purpose COPD is mainly caused by tobacco smoking and is associated with a high frequency of coronary artery disease. There is growing recognition that the inflammation in COPD is not only confined to the lungs but also involves the systemic circulation and can impact nonpulmonary organs, including blood vessels. α1-antitrypsin–low-density lipoprotein (AT-LDL) complex is an oxidatively modified LDL that accelerates atherosclerosis. Curcumin, one of the best-investigated natural products, is a powerful antioxidant. However, the effects of curcumin on AT-LDL remain unknown. We hypothesized that Theracurmin®, a highly absorptive curcumin with improved bioavailability using a drug delivery system, ameliorates the inflammatory status in subjects with mild COPD. Patients and methods This is a randomized, double-blind, parallel-group study. Subjects with stages I–II COPD according to the Japanese Respiratory Society criteria were randomly assigned to receive 90 mg Theracurmin® or placebo twice a day for 24 weeks, and changes in inflammatory parameters were evaluated. Results There were no differences between the Theracurmin® and placebo groups in terms of age, male/female ratio, or body mass index in 39 evaluable subjects. The percent changes in blood pressure and hemoglobin A1c and LDL-cholesterol, triglyceride, or high-density lipoprotein-cholesterol levels after treatment were similar for the two groups. However, the percent change in the AT-LDL level was significantly (P=0.020) lower in the Theracurmin® group compared with the placebo group. Conclusion Theracurmin® reduced levels of atherosclerotic AT-LDL, which may lead to the prevention of future cardiovascular events in mild COPD subjects. PMID:27616885

  3. Endothelial cells and macrophages, partners in atherosclerotic plaque progression.

    PubMed

    Antohe, Felicia

    2006-01-01

    Heart disease and stroke, the main cardiovascular diseases (CVD), have become global epidemics in our days. High levels of cholesterol and other abnormal lipids are among the main risk factors of atherosclerosis, the number one killer in the world. However, recent advances in CVD treatment together with improvements in surgical techniques have increased the quality of life and reduced premature death rates and disabilities. Nevertheless, they still add a heavy burden to the rising global costs of health care. The medical priorities highlight not only the need for early recognition of the warning signs of a heart attack, but also the need for early biomarkers for prevention. Two active partners in the development and progression of atherosclerotic plaques are the macrophages and endothelial cells that influence each other and modify the microenvironment composition of the plaque leading to either rapid progression or regression of individual lesions in patients. In this review we address two specific aspects related to atherosclerosis: i) the way in which folic acid and folic acid conjugates may be helpful to identify activated macrophages and ii) the high potential of proteomic analysis to evidence and identify the multiple changes induced in activated vascular cells. PMID:17178598

  4. Variogram methods for texture classification of atherosclerotic plaque ultrasound images

    NASA Astrophysics Data System (ADS)

    Jeromin, Oliver M.; Pattichis, Marios S.; Pattichis, Constantinos; Kyriacou, Efthyvoulos; Nicolaides, Andrew

    2006-03-01

    Stroke is the third leading cause of death in the western world and the major cause of disability in adults. The type and stenosis of extracranial carotid artery disease is often responsible for ischemic strokes, transient ischemic attacks (TIAs) or amaurosis fugax (AF). The identification and grading of stenosis can be done using gray scale ultrasound scans. The appearance of B-scan pictures containing various granular structures makes the use of texture analysis techniques suitable for computer assisted tissue characterization purposes. The objective of this study is to investigate the usefulness of variogram analysis in the assessment of ultrasound plague morphology. The variogram estimates the variance of random fields, from arbitrary samples in space. We explore stationary random field models based on the variogram, which can be applied in ultrasound plaque imaging leading to a Computer Aided Diagnosis (CAD) system for the early detection of symptomatic atherosclerotic plaques. Non-parametric tests on the variogram coefficients show that the cofficients coming from symptomatic versus asymptomatic plaques come from distinct distributions. Furthermore, we show significant improvement in class separation, when a log point-transformation is applied to the images, prior to variogram estimation. Model fitting using least squares is explored for anisotropic variograms along specific directions. Comparative classification results, show that variogram coefficients can be used for the early detection of symptomatic cases, and also exhibit the largest class distances between symptomatic and asymptomatic plaque images, as compared to over 60 other texture features, used in the literature.

  5. An uncommon cause of chest pain - penetrating atherosclerotic aortic ulcer.

    PubMed

    Kyaw, Htoo; Sadiq, Sanah; Chowdhury, Arnab; Gholamrezaee, Rashin; Yoe, Linus

    2016-01-01

    Chest pain is a very common symptom and can be of cardiac or non-cardiac origin. It accounts for approximately 5.5 million annual emergency room visits in the United States, according to 2011 CDC data. Penetrating atherosclerotic aortic ulcer (PAU), an uncommon condition, is also a potential cause of chest pain. We here report the case of a 65-year-old woman who presented with atypical chest and back pain. The pain persisted for 4 weeks necessitating two emergency room visits. Initial tests were non-significant including cardiac troponins, an electrocardiogram (EKG), and a chest X-ray on her first visit. Upon her second visit, she underwent a computed tomography angiogram of chest with contrast which revealed a PAU with an intramural hematoma in descending aorta. The PAU was finally diagnosed with an exclusion of other chest pain causes. She was treated non-surgically with a blood pressure control strategy and pain management. After a 2-month period of smoking cessation and following the achievement of a controlled blood pressure, she felt well without chest pain. PMID:27406453

  6. Endothelial microparticles as conveyors of information in atherosclerotic disease.

    PubMed

    Schiro, A; Wilkinson, F L; Weston, R; Smyth, J V; Serracino-Inglott, F; Alexander, M Y

    2014-06-01

    Endothelial microparticles (EMPs) are complex submicron membrane-shed vesicles released into the circulation following endothelium cell activation or apoptosis. They are classified as either physiological or pathological, with anticoagulant or pro-inflammatory effects respectively. Endothelial dysfunction caused by inflammation is a key initiating event in atherosclerotic plaque formation. Athero-emboli, resulting from ruptured carotid plaques are a major cause of stroke. Current clinical techniques for arterial assessment, angiography and carotid ultrasound, give accurate information about stenosis but limited evidence on plaque composition, inflammation or vulnerability; as a result, patients with asymptomatic, or fragile carotid lesions, may not be identified and treated effectively. There is a need to discover novel biomarkers and develop more efficient diagnostic approaches in order to stratify patients at most risk of stroke, who would benefit from interventional surgery. Increasing evidence suggests that EMPs play an important role in the pathogenesis of cardiovascular disease, acting as a marker of damage, either exacerbating disease progression or triggering a repair response. In this regard, it has been suggested that EMPs have the potential to act as biomarkers of disease status. In this review, we will present the evidence to support this hypothesis and propose a novel concept for the development of a diagnostic device that could be implemented in the clinic. PMID:24721189

  7. Recanalization Results After Intracranial Stenting of Atherosclerotic Stenoses

    SciTech Connect

    Blasel, Stella Yuekzek, Zeynep; Kurre, Wiebke; Berkefeld, Joachim; Neumann-Haefelin, Tobias; Hattingen, Elke; Mesnil de Rochemont, Richard du

    2010-10-15

    The purpose of this investigation was to provide a detailed description of the angiographic results after stenting of high-grade intracranial stenosis using balloon-expandable stents. Forty consecutive patients with symptomatic atherosclerotic intracranial stenosis >50% received endovascular treatment by placement of balloon-expandable stents using the concept of slight underdilation and strict avoidance of overdilation. Intra-arterial digital subtraction angiography images before and after stenting in the same projection were reviewed for pre- and post-therapeutic measurement of the degree of stenosis and evaluation of morphologic criteria like plaque coverage, stent apposition, patency of side branches, and signs of dissection or vasospasm. Stenting decreased the mean percentage stenosis from 76.2 (WASID criteria) to 20.8%. Residual stenosis ranged from 0 to 55% with residual stenosis >50% in two of 40 cases. Technical success rate was 95%. There were no major vessel complications, but minor abnormalities like incomplete stent apposition (8/40) or plaque coverage (7/40), incomplete filling of side branches (13/40), and minor dissections after stenting (2/40) were seen. One case with incomplete stent apposition and two cases with side branch compromise were associated with clinical symptoms. In conclusion, intracranial stenting with slight underdilation avoided major vessel complication and created reliable luminal gain. Suboptimal recanalization results were frequently detected and may be the source of neurological complications in individual cases.

  8. Extracellular matrix protein gene expression in atherosclerotic hypertensive pulmonary arteries.

    PubMed Central

    Botney, M. D.; Kaiser, L. R.; Cooper, J. D.; Mecham, R. P.; Parghi, D.; Roby, J.; Parks, W. C.

    1992-01-01

    Lobar pulmonary arteries from patients with unexplained pulmonary hypertension were obtained at the time of single-lung transplantation to determine the response of large elastic vessels to increased intraluminal pressure. Specifically, human pulmonary arteries were examined to determine if remodeling remained active at the time of surgery and whether remodeling was similar to previously reported remodeling observed in several animal models. Grossly, the hypertensive vessels appeared atherosclerotic. Histochemical stains revealed a thick, diffuse neointima in hypertensive vessels compared with normal vessels. Immunohistochemistry demonstrated elastin protein in the neointima and in situ hybridization studies demonstrated tropoelastin mRNA largely in the neointima. Similarly, immunohistochemistry and in situ hybridization detected cellular fibronectin, thrombospondin and type I collagen protein and mRNA within the thickened intima from hypertensive vessels. These studies provide evidence that hypertensive vessels in patients with severe chronic pulmonary hypertension are actively remodeling but that the pattern of remodeling is different from previously described animal models. Images Figure 1 Figure 2 Figure 3 PMID:1739129

  9. Directional spatial frequency analysis of lipid distribution in atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Korn, Clyde; Reese, Eric; Shi, Lingyan; Alfano, Robert; Russell, Stewart

    2016-04-01

    Atherosclerosis is characterized by the growth of fibrous plaques due to the retention of cholesterol and lipids within the artery wall, which can lead to vessel occlusion and cardiac events. One way to evaluate arterial disease is to quantify the amount of lipid present in these plaques, since a higher disease burden is characterized by a higher concentration of lipid. Although therapeutic stimulation of reverse cholesterol transport to reduce cholesterol deposits in plaque has not produced significant results, this may be due to current image analysis methods which use averaging techniques to calculate the total amount of lipid in the plaque without regard to spatial distribution, thereby discarding information that may have significance in marking response to therapy. Here we use Directional Fourier Spatial Frequency (DFSF) analysis to generate a characteristic spatial frequency spectrum for atherosclerotic plaques from C57 Black 6 mice both treated and untreated with a cholesterol scavenging nanoparticle. We then use the Cauchy product of these spectra to classify the images with a support vector machine (SVM). Our results indicate that treated plaque can be distinguished from untreated plaque using this method, where no difference is seen using the spatial averaging method. This work has the potential to increase the effectiveness of current in-vivo methods of plaque detection that also use averaging methods, such as laser speckle imaging and Raman spectroscopy.

  10. Inflammatory and atherosclerotic interactions in the depleted uremic patient.

    PubMed

    Stenvinkel, P

    2001-01-01

    Despite the improvements in dialysis technology, the cardiovascular mortality rate is still unacceptably high among dialysis patients. It is obvious that traditional risk factors, such as hypertension, chronic heart failure (CHF), dyslipidemia and diabetes mellitus, may account for a large part of the increased cardiovascular mortality rate in these patients. However, based on recent research it could be speculated that other, non-traditional risk factors might also contribute to the high cardiovascular mortality rate in dialysis patients. Chronic inflammation, as evidenced by increased levels of pro-inflammatory cytokines and C-reactive protein (CRP), is a common feature in dialysis patients and is associated with an increased cardiovascular morbidity and mortality. Indeed, elevated levels of pro-inflammatory cytokines (such as TNF-alpha, IL-1 and IL-6) may cause malnutrition and progressive atherosclerotic cardiovascular disease by several pathogenetic mechanisms, which will be discussed in this review. Based on the strong associations observed between malnutrition, inflammation and atherosclerosis in patients with chronic renal failure (CRF) we have proposed that these features constitute a specific syndrome (MIA), which carries a high mortality rate. As elevated levels of pro-inflammatory cytokines may play a central part in the vicious circle of malnutrition, inflammation and atherosclerosis, further research is needed to investigate whether or not different anti-cytokine treatment strategies may improve survival in dialysis patients.

  11. Multimodal spectroscopy detects features of vulnerable atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Šćepanović, Obrad R.; Fitzmaurice, Maryann; Miller, Arnold; Kong, Chae-Ryon; Volynskaya, Zoya; Dasari, Ramachandra R.; Kramer, John R.; Feld, Michael S.

    2011-01-01

    Early detection and treatment of rupture-prone vulnerable atherosclerotic plaques is critical to reducing patient mortality associated with cardiovascular disease. The combination of reflectance, fluorescence, and Raman spectroscopy-termed multimodal spectroscopy (MMS)-provides detailed biochemical information about tissue and can detect vulnerable plaque features: thin fibrous cap (TFC), necrotic core (NC), superficial foam cells (SFC), and thrombus. Ex vivo MMS spectra are collected from 12 patients that underwent carotid endarterectomy or femoral bypass surgery. Data are collected by means of a unitary MMS optical fiber probe and a portable clinical instrument. Blinded histopathological analysis is used to assess the vulnerability of each spectrally evaluated artery lesion. Modeling of the ex vivo MMS spectra produce objective parameters that correlate with the presence of vulnerable plaque features: TFC with fluorescence parameters indicative of collagen presence; NC/SFC with a combination of diffuse reflectance β-carotene/ceroid absorption and the Raman spectral signature of lipids; and thrombus with its Raman signature. Using these parameters, suspected vulnerable plaques can be detected with a sensitivity of 96% and specificity of 72%. These encouraging results warrant the continued development of MMS as a catheter-based clinical diagnostic technique for early detection of vulnerable plaques.

  12. A data processing method for determining instantaneous angular speed and acceleration of crankshaft in an aircraft engine-propeller system using a magnetic encoder

    NASA Astrophysics Data System (ADS)

    Yu, S. D.; Zhang, X.

    2010-05-01

    This paper presents a method for determining the instantaneous angular speed and instantaneous angular acceleration of the crankshaft in a reciprocating engine and propeller dynamical system from electrical pulse signals generated by a magnetic encoder. The method is based on accurate determination of the measured global mean angular speed and precise values of times when leading edges of individual magnetic teeth pass through the magnetic sensor. Under a steady-state operating condition, a discrete deviation time vs. shaft rotational angle series of uniform interval is obtained and used for accurate determination of the crankshaft speed and acceleration. The proposed method for identifying sub- and super-harmonic oscillations in the instantaneous angular speeds and accelerations is new and efficient. Experiments were carried out on a three-cylinder four-stroke Saito 450R model aircraft engine and a Solo propeller in connection with a 64-teeth Admotec KL2202 magnetic encoder and an HS-4 data acquisition system. Comparisons with an independent data processing scheme indicate that the proposed method yields noise-free instantaneous angular speeds and is superior to the finite difference based methods commonly used in the literature.

  13. Phytoestrogen-Rich Dietary Supplements in Anti-Atherosclerotic Therapy in Postmenopausal Women.

    PubMed

    Sobenin, Igor A; Myasoedova, Veronica A; Orekhov, Alexander N

    2016-01-01

    Cardiovascular diseases remain the leading cause of morbidity and mortality among postmenopausal women in western societies. There are still no specific and highly efficient methods of preservation of women's vascular health in modern preventive medicine. For many years physicians have assumed that hormone replacement therapy prevents the development of atherosclerosis in menopausal women. However, the results of the largest international trials involving thousands of women have completely destroyed this hope. The modern perspective for the development of effective and safe drugs to enhance the quality of life and to prevent atherosclerosis progression in postmenopausal women may be the use of phytoestrogens, the substances of plant origin possessing estrogen- like effects, and possibly providing anti-atherosclerotic and anti-climacteric action. Phytoestrogens are often considered as a possible alternative to hormone replacement therapy, since they are believed to alleviate some symptoms of menopause. However, until now there is no exact evidence to consider phytoestrogens as the substances that protect women from atherosclerosis. It should be noted that the data from clinical studies with inconsistent results are mainly inconsistent per se, as most of the studies have serious limitations due to the study design and the participants' compliance. Nevertheless, there is a substantial evidence that phytoestrogens have the potential to address several conditions and diseases associated with the menopausal transition. Phytoestrogens, at least, can potentially reduce atherosclerosis and atherosclerosis-related diseases through multiple mechanisms, by regulating serum lipid metabolism, arterial vessels, cytokine levels, and coagulation/fibrinolysis system. However, a skepticism exists concerning the true potential of phytoestrogens to beneficially modify these processes. An analysis of findings from supplementing the diet with phytoestrogens has failed, in general, to

  14. Proton acceleration in the electrostatic sheaths of hot electrons governed by strongly relativistic laser-absorption processes.

    PubMed

    Ter-Avetisyan, S; Schnürer, M; Sokollik, T; Nickles, P V; Sandner, W; Reiss, H R; Stein, J; Habs, D; Nakamura, T; Mima, K

    2008-01-01

    Two different laser energy absorption mechanisms at the front side of a laser-irradiated foil have been found to occur, such that two distinct relativistic electron beams with different properties are produced. One beam arises from the ponderomotively driven electrons propagating in the laser propagation direction, and the other is the result of electrons driven by resonance absorption normal to the target surface. These properties become evident at the rear surface of the target, where they give rise to two spatially separated sources of ions with distinguishable characteristics when ultrashort (40fs) high-intensity laser pulses irradiate a foil at 45 degrees incidence. The laser pulse intensity and the contrast ratio are crucial. One can establish conditions such that one or the other of the laser energy absorption mechanisms is dominant, and thereby one can control the ion acceleration scenarios. The observations are confirmed by particle-in-cell (PIC) simulations.

  15. Remote sensing of the energy of Jovian auroral electrons with STIS: a clue to unveil plasma acceleration processes

    NASA Astrophysics Data System (ADS)

    Gerard, Jean-Claude

    2013-10-01

    The polar aurora, an important energy source for the Earth's upper atmosphere, is about two orders of magnitude more intense at Jupiter where it releases approximately 10 GW in Jupiter's thermosphere. So far, HST observations of Jupiter's aurora have concentrated on the morphology and the relationship between the solar wind and the brightness distribution. While STIS-MAMA is still operational, time is now critical to move into a new era where FUV long-slit spectroscopy and the spatial scanning capabilities of HST are combined. We propose to use this powerful tool to remotely sense the characteristics of the precipitated electrons by slewing the spectral slit over the different auroral components. It will then be possible to associate electron energies with spatial auroral components and constrain acceleration mechanisms {field-aligned acceleration, magnetic field reconnection, pitch angle electron scattering} associated with specific emission regions. For this, a combination of FUV imaging with STIS long slit spectroscopy will map the spatial variations of the auroral depth and thus the energy of the precipitated electrons. These results will be compared with current models of the Jovian magnetosphere-ionosphere interactions and will provide key inputs to a 3-D model of the Jupiter's atmosphere global heat budget and dynamics currently under development. This compact timely program is designed to provide a major step forward for a better understanding of the physical interactions taking place in Jupiter's magnetosphere and their effects on giant planets' atmospheres, a likely paradigm for many giant fast spinning planets with massive magnetic field in the universe.

  16. Using compute unified device architecture-enabled graphic processing unit to accelerate fast Fourier transform-based regression Kriging interpolation on a MODIS land surface temperature image

    NASA Astrophysics Data System (ADS)

    Hu, Hongda; Shu, Hong; Hu, Zhiyong; Xu, Jianhui

    2016-04-01

    Kriging interpolation provides the best linear unbiased estimation for unobserved locations, but its heavy computation limits the manageable problem size in practice. To address this issue, an efficient interpolation procedure incorporating the fast Fourier transform (FFT) was developed. Extending this efficient approach, we propose an FFT-based parallel algorithm to accelerate regression Kriging interpolation on an NVIDIA® compute unified device architecture (CUDA)-enabled graphic processing unit (GPU). A high-performance cuFFT library in the CUDA toolkit was introduced to execute computation-intensive FFTs on the GPU, and three time-consuming processes were redesigned as kernel functions and executed on the CUDA cores. A MODIS land surface temperature 8-day image tile at a resolution of 1 km was resampled to create experimental datasets at eight different output resolutions. These datasets were used as the interpolation grids with different sizes in a comparative experiment. Experimental results show that speedup of the FFT-based regression Kriging interpolation accelerated by GPU can exceed 1000 when processing datasets with large grid sizes, as compared to the traditional Kriging interpolation running on the CPU. These results demonstrate that the combination of FFT methods and GPU-based parallel computing techniques greatly improves the computational performance without loss of precision.

  17. Using compute unified device architecture-enabled graphic processing unit to accelerate fast Fourier transform-based regression Kriging interpolation on a MODIS land surface temperature image

    NASA Astrophysics Data System (ADS)

    Hu, Hongda; Shu, Hong; Hu, Zhiyong; Xu, Jianhui

    2016-04-01

    Kriging interpolation provides the best linear unbiased estimation for unobserved locations, but its heavy computation limits the manageable problem size in practice. To address this issue, an efficient interpolation procedure incorporating the fast Fourier transform (FFT) was developed. Extending this efficient approach, we propose an FFT-based parallel algorithm to accelerate regression Kriging interpolation on an NVIDIA® compute unified device architecture (CUDA)-enabled graphic processing unit (GPU). A high-performance cuFFT library in the CUDA toolkit was introduced to execute computation-intensive FFTs on the GPU, and three time-consuming processes were redesigned as kernel functions and executed on the CUDA cores. A MODIS land surface temperature 8-day image tile at a resolution of 1 km was resampled to create experimental datasets at eight different output resolutions. These datasets were used as the interpolation grids with different sizes in a comparative experiment. Experimental results show that speedup of the FFT-based regression Kriging interpolation accelerated by GPU can exceed 1000 when processing datasets with large grid sizes, as compared to the traditional Kriging interpolation running on the CPU. These results demonstrate that the combination of FFT methods and GPU-based parallel computing techniques greatly improves the computational performance without loss of precision.

  18. Murine atherosclerotic plaque imaging with the USPIO Ferumoxtran-10.

    PubMed

    Klug, Gert; Kampf, Thomas; Ziener, Christan; Parczyk, Marco; Bauer, Elizabeth; Herold, Volker; Rommel, Eberhard; Jakob, Peter Michael; Bauer, Wolfgang Rudolf

    2009-01-01

    In this study we intended to image plaque inflammation in a murine model of atherosclerosis with MRI and Ferumoxtran-10 (Sinerem, Guerbet, France). 8 apoE-/- mice were injected 500 micromol Fe/kg or 1000 micromol Fe/kg Ferumoxtran-10. 2 apoE-/- mice were injected NaCl. After a post-contrast time of 24 to 336 hours the mice were scarificed and the aortas were imaged ex vivo. All measurements were performed on a 17.6 Tesla Bruker AVANCE 750WB MR scanner (Bruker, Germany). Spin-echo sequences and gradient-echo sequences with variable TE were performed and T2* maps were generated. Prussian-blue and hematoxilin-eosin histology were obtained afterwards and iron-uptake was quantified by counting iron positive areas. 2 apoE-/- mice were imaged in vivo before and 48 hours after 1000 micromol Fe/kg. Atheroma iron uptake was not elevated after 24 hours compared to controls. 48 hours after 1000 micromol Fe/kg but not 500 micromol Fe/kg histology revealed a 1.3- fold increase in plaque iron content compared to NaCl injected mice. Normalized T2*-times decreased from 0.86+/-0.02 in controls to 0.66+/-0.15 after a dose of 500 micromol Fe/ml and 0.59+/-0.14 in mice injected with 1000 micromol Fe/Kg (p=0.038). These results translated into a mean of 122% increase in CNR, as measured by in vivo MRI. We have demonstrated that Ferumoxtran-10 is taken up by atherosclerotic plaques in untreated apoE-/- mice and this alters plaque signal properties.

  19. Global Overview of the Epidemiology of Atherosclerotic Cardiovascular Disease.

    PubMed

    Barquera, Simon; Pedroza-Tobías, Andrea; Medina, Catalina; Hernández-Barrera, Lucía; Bibbins-Domingo, Kirsten; Lozano, Rafael; Moran, Andrew E

    2015-07-01

    Atherosclerotic cardiovascular disease (ACD) is the leading cause of mortality worldwide. The objective of this paper is to provide an overview of the global burden of ACD and its risk factors and to discuss the main challenges and opportunities for prevention. Publicly available data from the Global Burden of Disease Study were analyzed for ischemic heart disease (IHD), ischemic stroke and ACD risk factors. Data from the WHO Global Health Observatory were used to describe prevalence of diverse cardiometabolic risk factors. World Bank Gross Domestic Product per capita (GDPc) information was used to categorize countries according to income level. Cardiovascular mortality decreased globally from 1990-2010 with important differences by GDPc; during 1990 there was a positive association between IHD mortality and GDPc. Higher-income countries had higher rates compared to those of lower-income countries. High levels of body mass index (BMI), blood pressure, glucose and cholesterol have a differential contribution to mortality by income group over time; high-income countries have been able to reduce the contribution from these risk factors in the last 20 years, whereas lower/middle income countries show an increasing trend in mortality attributable to high BMI and glucose. Although age-adjusted ACD mortality rate trends decreased globally, the absolute number of ACD deaths is increasing in part due to the growth of the population and aging, as well as to important lifestyle and food-system changes that likely attenuate gains in prevention. Population and individual level preventable causes of ACD must be aggressively and efficiently targeted in countries of lower economic development in order to reduce the growing burden of disease due to ACD. PMID:26135634

  20. Optical detection of structural changes in human carotid atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Korol, R. M.; Canham, P. B.; Finlay, H. M.; Hammond, R. R.; Quantz, M.; Ferguson, G. G.; Liu, L. Y.; Lucas, A. R.

    2005-08-01

    Background: Arterial bifurcations are commonly the sites of developing atherosclerotic plaque that lead to arterial occlusions and plaque rupture (myocardial infarctions and strokes). Laser induced fluorescence (LIF) spectroscopy provides an effective nondestructive method supplying spectral information on extracellular matrix (ECM) protein composition, specifically collagen and elastin. Purpose: To investigate regional differences in the ECM proteins -- collagen I, III and elastin in unstable plaque by analyzing data from laser-induced fluorescence spectroscopy of human carotid endarterectomy specimens. Methods: Gels of ECM protein extracts (elastin, collagen types I & III) were measured as reference spectra and internal thoracic artery segments (extra tissue from bypass surgery) were used as tissue controls. Arterial segments and the endarterectomy specimens (n=21) were cut into 5mm cross-sectional rings. Ten fluorescence spectra per sampling area were then recorded at 5 sites per ring with argon laser excitation (357nm) with a penetration depth of 200 μm. Spectra were normalized to maximum intensity and analyzed using multiple regression analysis. Tissue rings were fixed in formalin (within 3 hours of surgery), sectioned and stained with H&E or Movat's Pentachrome for histological analysis. Spectroscopy data were correlated with immunohistology (staining for elastin, collagen types I, III and IV). Results: Quantitative fluorescence for the thoracic arteries revealed a dominant elastin component on the luminal side -- confirmed with immunohistology and known artery structure. Carotid endarterectomy specimens by comparison had a significant decrease in elastin signature and increased collagen type I and III. Arterial spectra were markedly different between the thoracic and carotid specimens. There was also a significant elevation (p<0.05) of collagen type I distal to the bifurcation compared to proximal tissue in the carotid specimens. Conclusion: Fluorescence

  1. An Experimental Fluid dynamics Study of Exact-Replica Atherosclerotic Carotid Bifurcations

    NASA Astrophysics Data System (ADS)

    Bale-Glickman, Jocelyn; Selby, Kathy; Saloner, David; Savas, Omer

    2003-11-01

    Physiological flow studies are carried out in two different models of atherosclerotic carotid bifurcations using flow visualization and particle image velocimetry (PIV). The flow models exactly replicate the lumen of plaques excised intact from patients with severe atherosclerosis. A boundary treatment technique is employed in PIV processing to estimate the flow strain rate near the wall, hence to estimate the wall shear stresses (WSS) to a first order accuracy. The systolic and diastolic Reynolds numbers are about 900 and 300, respectively, which match Doppler Ultrasound scans done on the patients just before surgery. The complex internal geometry of the diseased artery combined with the pulsatile input flows gives exceedingly complex flow patterns. The flows are highly three-dimensional and chaotic in which the details vary from cycle to cycle. The flow patterns include internal jets, three-dimensional shear layers, stagnation lines, separation zones and recirculation zones. The vorticity and streamline maps confirm the highly complex and three-dimensional nature of the flow. WSS are estimated to range from -7 Pa to 30 Pa at the stenotic neck over time. Companion experiments are also carried out with sinusoidal and steady CCA input flows for comparison.

  2. Human miR-221/222 in Physiological and Atherosclerotic Vascular Remodeling

    PubMed Central

    Chistiakov, Dmitry A.; Sobenin, Igor A.; Orekhov, Alexander N.; Bobryshev, Yuri V.

    2015-01-01

    A cluster of miR-221/222 is a key player in vascular biology through exhibiting its effects on vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). These miRNAs contribute to vascular remodeling, an adaptive process involving phenotypic and behavioral changes in vascular cells in response to vascular injury. In proliferative vascular diseases such as atherosclerosis, pathological vascular remodeling plays a prominent role. The miR-221/222 cluster controls development and differentiation of ECs but inhibits their proangiogenic activation, proliferation, and migration. miR-221/222 are primarily implicated in maintaining endothelial integrity and supporting quiescent EC phenotype. Vascular expression of miR-221/222 is upregulated in initial atherogenic stages causing inhibition of angiogenic recruitment of ECs and increasing endothelial dysfunction and EC apoptosis. In contrast, these miRNAs stimulate VSMCs and switching from the VSMC “contractile” phenotype to the “synthetic” phenotype associated with induction of proliferation and motility. In atherosclerotic vessels, miR-221/222 drive neointima formation. Both miRNAs contribute to atherogenic calcification of VSMCs. In advanced plaques, chronic inflammation downregulates miR-221/222 expression in ECs that in turn could activate intralesion neoangiogenesis. In addition, both miRNAs could contribute to cardiovascular pathology through their effects on fat and glucose metabolism in nonvascular tissues such as adipose tissue, liver, and skeletal muscles. PMID:26221589

  3. The role of neuropeptide Y in the pathophysiology of atherosclerotic cardiovascular disease.

    PubMed

    Zhu, Ping; Sun, Weiwei; Zhang, Chenliang; Song, Zhiyuan; Lin, Shu

    2016-10-01

    With average life expectancy rising greatly, the incidence rate of arteriosclerotic cardiovascular disease (ASCVD) has significantly increased. The heart disease has now become the number one killer that threatens the global population health, the second is stroke. It will be of great significance to investigate the underlying pathophysiological mechanisms of ASCVD in order to promote effective prevention and treatment. The neuropeptide Y (NPY) has now been discovered for more than thirty years and is widely distributed in the central nervous system (CNS) and peripheral tissues. By combining with certain receptors, NPY performs a variety of physiological functions, including the regulation of food intake, cardiovascular effects, development, hormonal secretion, sexual behavior, biological rhythms, temperature and emotion. In ASCVD, increased peripheral NPY was involved in the pathophysiological process of atherosclerosis through affecting the vascular endothelial dysfunction, the formation of foam cells, the proliferation of vascular smooth muscle cells, the local inflammatory response of plaques and the activation and aggregation of platelets. Via central and/or the peripheral nervous system, increased NPY was associated with dyslipidemia, hypertension, obesity, diabetes, impaired glucose tolerance, and smoking which are all risk factors for ASCVD. In this review, we summarize the role of neuropeptide Y in the development of atherosclerotic cardiovascular disease.

  4. Automatic classification of atherosclerotic plaques imaged with intravascular OCT (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Rico-Jimenez, Jose D.; Campos-Delgado, Daniel U.; Villiger, Martin; Bouma, Brett; Jo, Javier A.

    2016-03-01

    A novel computational method for plaque tissue characterization based on Intravascular Optical Coherence Tomography (IV-OCT) is presented. IV-OCT is becoming a powerful tool for the clinical evaluation of atherosclerotic plaques; however, it requires a trained expert for visual assessment and interpretation of the imaged plaques. Moreover, due to the inherit effect of speckle and the scattering attenuation of the optical scheme the direct interpretation of OCT images is limited. To overcome these difficulties, we propose to automatically identify the A-line profiles of the most significant plaque types (normal, fibrotic, or lipid-rich) and their respective abundance by using a probabilistic framework and blind alternated least squares to achieve the optimal decomposition. In this context, we present preliminary results of this novel probabilistic classification tool for intravascular OCT that relies on two steps. First, the B-scan is pre-processed to remove catheter artifacts, segment the lumen, select the region of interest (ROI), flatten the tissue surface, and reduce the speckle effect by a spatial entropy filter. Next, the resulting image is decomposed and its A-lines are classified by an automated strategy based on alternating-least-squares optimization. Our early results are encouraging and suggest that the proposed methodology can identify normal tissue, fibrotic and lipid-rich plaques from IV-OCT images.

  5. Mechanical modeling of cholesterol crystallization in atherosclerotic plaques base on Micro-OCT images (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Luo, Yuemei; Liu, Xinyu; Chen, Si; Cui, Dongyao; Wang, Xianghong; Liu, Linbo

    2016-02-01

    Plaque rupture is the critical cause of cardiovascular thrombosis but this process is still under discussion. Recent studies show that, during crystallization, cholesterol crystals in atheromatous plaques accumulate rapidly in a limited space and may result in plaque rupture. However, the actual role of cholesterol crystals on plaque rupture remains unclear due to the lack of detailed morphological information of cholesterol crystals. In this study, we used a Micro-optical coherence tomography (µOCT) setup with 1-2 µm spatial resolution to extract the geometry of cholesterol crystals from human atherosclerotic artery ex vivo firstly. With measured dimensions of cholesterol crystals by this µOCT system (the average length and thickness of 269.1±80.16 µm and 3.0±0.33 µm), we developed a two-dimensional mechanical model in which rectangular shaped cholesterol crystals distribute at different locations spatially. We predicted the stress on the thin cap induced by the expansion of cholesterol crystals by use of finite-element method. Since a large portion of plaques (58%) rupture at points of peak circumferential stress (PCS), we used PCS as the primary indicator of plaque stability with blood pressure of 14.6 kPa on the lumen. The results demonstrate that loading of the concentrated crystals especially at the cap shoulder destabilize the plaque by proportionally increasing the PCS, while evenly distributed crystals loading along the cap might impose less PCS to the plaque than the concentrated case.

  6. Abolished synthesis of cholic acid reduces atherosclerotic development in apolipoprotein E knockout mice.

    PubMed

    Slätis, Katharina; Gåfvels, Mats; Kannisto, Kristina; Ovchinnikova, Olga; Paulsson-Berne, Gabrielle; Parini, Paolo; Jiang, Zhao-Yan; Eggertsen, Gösta

    2010-11-01

    To investigate the effects of abolished cholic acid (CA) synthesis in the ApoE knockout model [apolipoprotein E (apoE) KO],a double-knockout (DKO) mouse model was created by crossbreeding Cyp8b1 knockout mice (Cyp8b1 KO), unable to synthesize the primary bile acid CA, with apoE KO mice. After 5 months of cholesterol feeding, the development of atherosclerotic plaques in the proximal aorta was 50% less in the DKO mice compared with the apoE KO mice. This effect was associated with reduced intestinal cholesterol absorption, decreased levels of apoB-containing lipoproteins in the plasma, enhanced bile acid synthesis, reduced hepatic cholesteryl esters, and decreased hepatic activity of ACAT2. The upregulation of Cyp7a1 in DKO mice seemed primarily caused by reduced expression of the intestinal peptide FGF15. Treatment of DKO mice with the farnesoid X receptor (FXR) agonist GW4064 did not alter the intestinal cholesterol absorption, suggesting that the action of CA in this process is confined mainly to formation of intraluminal micelles and less to its ability to activate the nuclear receptor FXR. Inhibition of CA synthesis may offer a therapeutic strategy for the treatment of hyperlipidemic conditions that lead to atherosclerosis.

  7. Quantitative profiling of oxylipins in plasma and atherosclerotic plaques of hypercholesterolemic rabbits.

    PubMed

    Bojic, Lazar A; McLaren, David G; Harms, Amy C; Hankemeier, Thomas; Dane, Adrie; Wang, Sheng-Ping; Rosa, Ray; Previs, Stephen F; Johns, Douglas G; Castro-Perez, Jose M

    2016-01-01

    Oxylipins are oxidation products of polyunsaturated fatty acids (PUFAs) that affect a broad range of physiological processes, including cell proliferation, inflammation, inflammation resolution, and vascular function. Moreover, oxylipins are readily detectable in plasma, and certain subsets of oxylipins have been detected in human atherosclerotic lesions. Taken together, we set out to produce a detailed quantitative assessment of plasma and plaque oxylipins in a widely used model of atherosclerosis, to identify potential biomarkers of disease progression. We administered regular chow or regular chow supplemented with 0.5% cholesterol (HC) to male New Zealand white rabbits for 12 weeks to induce hypercholesterolemia and atherosclerosis. Our targeted lipidomic analyses of oxylipins on plaques isolated from rabbits fed the HC diet detected 34 oxylipins, 28 of which were in compliance with our previously established quality control acceptance criteria. The arachidonic acid (AA) metabolite derived from the COX pathway, 6-keto-PGF1α was the most abundant plaque oxylipin, followed by the linoleic acid (LA) metabolites 9-HODE, 13-HODE and 9,12,13-TriHOME and the arachidonic acid (AA)-derivatives 11-HETE and 12-HETE. We additionally found that the most abundant oxylipins in plasma were three of the five most abundant oxylipins in plaque, namely 11-HETE, 13-HODE, and 9-HODE. The studies reported here make the first step towards a comprehensive characterization of oxylipins as potentially translatable biomarkers of atherosclerosis.

  8. The role of neuropeptide Y in the pathophysiology of atherosclerotic cardiovascular disease.

    PubMed

    Zhu, Ping; Sun, Weiwei; Zhang, Chenliang; Song, Zhiyuan; Lin, Shu

    2016-10-01

    With average life expectancy rising greatly, the incidence rate of arteriosclerotic cardiovascular disease (ASCVD) has significantly increased. The heart disease has now become the number one killer that threatens the global population health, the second is stroke. It will be of great significance to investigate the underlying pathophysiological mechanisms of ASCVD in order to promote effective prevention and treatment. The neuropeptide Y (NPY) has now been discovered for more than thirty years and is widely distributed in the central nervous system (CNS) and peripheral tissues. By combining with certain receptors, NPY performs a variety of physiological functions, including the regulation of food intake, cardiovascular effects, development, hormonal secretion, sexual behavior, biological rhythms, temperature and emotion. In ASCVD, increased peripheral NPY was involved in the pathophysiological process of atherosclerosis through affecting the vascular endothelial dysfunction, the formation of foam cells, the proliferation of vascular smooth muscle cells, the local inflammatory response of plaques and the activation and aggregation of platelets. Via central and/or the peripheral nervous system, increased NPY was associated with dyslipidemia, hypertension, obesity, diabetes, impaired glucose tolerance, and smoking which are all risk factors for ASCVD. In this review, we summarize the role of neuropeptide Y in the development of atherosclerotic cardiovascular disease. PMID:27389447

  9. Wakefield accelerators

    SciTech Connect

    Simpson, J.D.

    1990-01-01

    The search for new methods to accelerate particle beams to high energy using high gradients has resulted in a number of candidate schemes. One of these, wakefield acceleration, has been the subject of considerable R D in recent years. This effort has resulted in successful proof of principle experiments and in increased understanding of many of the practical aspects of the technique. Some wakefield basics plus the status of existing and proposed experimental work is discussed, along with speculations on the future of wake field acceleration. 10 refs., 6 figs.

  10. LINEAR ACCELERATOR

    DOEpatents

    Colgate, S.A.

    1958-05-27

    An improvement is presented in linear accelerators for charged particles with respect to the stable focusing of the particle beam. The improvement consists of providing a radial electric field transverse to the accelerating electric fields and angularly introducing the beam of particles in the field. The results of the foregoing is to achieve a beam which spirals about the axis of the acceleration path. The combination of the electric fields and angular motion of the particles cooperate to provide a stable and focused particle beam.

  11. Differential expression of bone matrix regulatory proteins in human atherosclerotic plaques.

    PubMed

    Dhore, C R; Cleutjens, J P; Lutgens, E; Cleutjens, K B; Geusens, P P; Kitslaar, P J; Tordoir, J H; Spronk, H M; Vermeer, C; Daemen, M J

    2001-12-01

    In the present study, we examined the expression of regulators of bone formation and osteoclastogenesis in human atherosclerosis because accumulating evidence suggests that atherosclerotic calcification shares features with bone calcification. The most striking finding of this study was the constitutive immunoreactivity of matrix Gla protein, osteocalcin, and bone sialoprotein in nondiseased aortas and the absence of bone morphogenetic protein (BMP)-2, BMP-4, osteopontin, and osteonectin in nondiseased aortas and early atherosclerotic lesions. When atherosclerotic plaques demonstrated calcification or bone formation, BMP-2, BMP-4, osteopontin, and osteonectin were upregulated. Interestingly, this upregulation was associated with a sustained immunoreactivity of matrix Gla protein, osteocalcin, and bone sialoprotein. The 2 modulators of osteoclastogenesis (osteoprotegerin [OPG] and its ligand, OPGL) were present in the nondiseased vessel wall and in early atherosclerotic lesions. In advanced calcified lesions, OPG was present in bone structures, whereas OPGL was only present in the extracellular matrix surrounding calcium deposits. The observed expression patterns suggest a tight regulation of the expression of bone matrix regulatory proteins during human atherogenesis. The expression pattern of both OPG and OPGL during atherogenesis might suggest a regulatory role of these proteins not only in osteoclastogenesis but also in atherosclerotic calcification. PMID:11742876

  12. Leukocyte trafficking-associated vascular adhesion protein 1 is expressed and functionally active in atherosclerotic plaques

    PubMed Central

    Silvola, Johanna M. U.; Virtanen, Helena; Siitonen, Riikka; Hellberg, Sanna; Liljenbäck, Heidi; Metsälä, Olli; Ståhle, Mia; Saanijoki, Tiina; Käkelä, Meeri; Hakovirta, Harri; Ylä-Herttuala, Seppo; Saukko, Pekka; Jauhiainen, Matti; Veres, Tibor Z.; Jalkanen, Sirpa; Knuuti, Juhani; Saraste, Antti; Roivainen, Anne

    2016-01-01

    Given the important role of inflammation and the potential association of the leukocyte trafficking-associated adhesion molecule vascular adhesion protein 1 (VAP-1) with atherosclerosis, this study examined whether functional VAP-1 is expressed in atherosclerotic lesions and, if so, whether it could be targeted by positron emission tomography (PET). First, immunohistochemistry revealed that VAP-1 localized to endothelial cells of intra-plaque neovessels in human carotid endarterectomy samples from patients with recent ischemic symptoms. In low-density lipoprotein receptor-deficient mice expressing only apolipoprotein B100 (LDLR−/−ApoB100/100), VAP-1 was expressed on endothelial cells lining inflamed atherosclerotic lesions; normal vessel walls in aortas of C57BL/6N control mice were VAP-1-negative. Second, we discovered that the focal uptake of VAP-1 targeting sialic acid-binding immunoglobulin-like lectin 9 based PET tracer [68Ga]DOTA-Siglec-9 in atherosclerotic plaques was associated with the density of activated macrophages (r = 0.58, P = 0.022). As a final point, we found that the inhibition of VAP-1 activity with small molecule LJP1586 decreased the density of macrophages in inflamed atherosclerotic plaques in mice. Our results suggest for the first time VAP-1 as a potential imaging target for inflamed atherosclerotic plaques, and corroborate VAP-1 inhibition as a therapeutic approach in the treatment of atherosclerosis. PMID:27731409

  13. Breakthrough: Fermilab Accelerator Technology

    ScienceCinema

    None

    2016-07-12

    There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

  14. ION ACCELERATOR

    DOEpatents

    Bell, J.S.

    1959-09-15

    An arrangement for the drift tubes in a linear accelerator is described whereby each drift tube acts to shield the particles from the influence of the accelerating field and focuses the particles passing through the tube. In one embodiment the drift tube is splii longitudinally into quadrants supported along the axis of the accelerator by webs from a yoke, the quadrants. webs, and yoke being of magnetic material. A magnetic focusing action is produced by energizing a winding on each web to set up a magnetic field between adjacent quadrants. In the other embodiment the quadrants are electrically insulated from each other and have opposite polarity voltages on adjacent quadrants to provide an electric focusing fleld for the particles, with the quadrants spaced sufficienily close enough to shield the particles within the tube from the accelerating electric field.

  15. Acceleration switch

    DOEpatents

    Abbin, J.P. Jr.; Devaney, H.F.; Hake, L.W.

    1979-08-29

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  16. Acceleration switch

    DOEpatents

    Abbin, Jr., Joseph P.; Devaney, Howard F.; Hake, Lewis W.

    1982-08-17

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  17. LINEAR ACCELERATOR

    DOEpatents

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  18. Application of a low level, uniform ultrasound field for the acceleration of enzymatic bio-processing of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzymatic bio-processing of cotton generates significantly less hazardous wastewater effluents, which are readily biodegradable, but it also has several critical shortcomings that impede its acceptance by industries: expensive processing costs and slow reaction rates. Our research has found that th...

  19. Protein profile in vascular wall of atherosclerotic mice analyzed ex vivo using FT-IR spectroscopy

    NASA Astrophysics Data System (ADS)

    Wrobel, Tomasz P.; Majzner, Katarzyna; Baranska, Malgorzata

    2012-10-01

    The structure of proteins in a tissue can undergo changes on account of disease state such as diabetes or atherosclerosis. In this work the protein profile in atherosclerotic tissue is monitored by FT-IR imaging coupled with Hierarchical Cluster Analysis (HCA). Additionally, a model for prediction of secondary structure of proteins content based on amide I and II range is used to show the distribution of analyzed proteins. A new protein class emerged in atherosclerotic tissue in the region of the plaque and additionally the plaque was found to be strongly mixed with smooth muscle cell. The calculated secondary structure contents of proteins in atherosclerotic tissue in comparison to healthy tissue showed an increase of structures related to beta-sheet (E and T) and a decrease of helical (H) and unassigned arrangements.

  20. MR histology of advanced atherosclerotic lesions of ApoE- knockout mice

    NASA Astrophysics Data System (ADS)

    Naumova, A.; Yarnykh, V.; Ferguson, M.; Rosenfeld, M.; Yuan, C.

    2016-02-01

    The purposes of this study were to examine the feasibility of determining the composition of advanced atherosclerotic plaques in fixed ApoE-knockout mice and to develop a time-efficient microimaging protocol for MR histological imaging on mice. Five formalin-fixed transgenic ApoE-knockout mice were imaged at the 9.4T Bruker BioSpec MR scanner using 3D spoiled gradient-echo sequence with an isotropic field of view of 24 mm3; TR 20.8 ms; TE 2.6 ms; flip angle 20°, resulted voxel size 47 × 63 × 94 pm3. MRI examination has shown that advanced atherosclerotic lesions of aorta, innominate and carotid arteries in ApoE-knockout mice are characterized by high calcification and presence of the large fibrofatty nodules. MRI quantification of atherosclerotic lesion components corresponded to histological assessment of plaque composition with a correlation coefficient of 0.98.

  1. Genesis and growth of extracellular-vesicle-derived microcalcification in atherosclerotic plaques.

    PubMed

    Hutcheson, Joshua D; Goettsch, Claudia; Bertazzo, Sergio; Maldonado, Natalia; Ruiz, Jessica L; Goh, Wilson; Yabusaki, Katsumi; Faits, Tyler; Bouten, Carlijn; Franck, Gregory; Quillard, Thibaut; Libby, Peter; Aikawa, Masanori; Weinbaum, Sheldon; Aikawa, Elena

    2016-03-01

    Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the aggregation of calcifying extracellular vesicles, and the formation of microcalcifications and ultimately large calcification areas. We also show that calcification morphology and the plaque's collagen content-two determinants of atherosclerotic plaque stability-are interlinked. PMID:26752654

  2. Genesis and growth of extracellular-vesicle-derived microcalcification in atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Hutcheson, Joshua D.; Goettsch, Claudia; Bertazzo, Sergio; Maldonado, Natalia; Ruiz, Jessica L.; Goh, Wilson; Yabusaki, Katsumi; Faits, Tyler; Bouten, Carlijn; Franck, Gregory; Quillard, Thibaut; Libby, Peter; Aikawa, Masanori; Weinbaum, Sheldon; Aikawa, Elena

    2016-03-01

    Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the aggregation of calcifying extracellular vesicles, and the formation of microcalcifications and ultimately large calcification areas. We also show that calcification morphology and the plaque’s collagen content--two determinants of atherosclerotic plaque stability--are interlinked.

  3. Texture based segmentation method to detect atherosclerotic plaque from optical tomography images

    NASA Astrophysics Data System (ADS)

    Prakash, Ammu; Hewko, Mark; Sowa, Michael; Sherif, Sherif

    2013-06-01

    Optical coherence tomography (OCT) imaging has been widely employed in assessing cardiovascular disease. Atherosclerosis is one of the major cause cardio vascular diseases. However visual detection of atherosclerotic plaque from OCT images is often limited and further complicated by high frame rates. We developed a texture based segmentation method to automatically detect plaque and non plaque regions from OCT images. To verify our results we compared them to photographs of the vascular tissue with atherosclerotic plaque that we used to generate the OCT images. Our results show a close match with photographs of vascular tissue with atherosclerotic plaque. Our texture based segmentation method for plaque detection could be potentially used in clinical cardiovascular OCT imaging for plaque detection.

  4. Chronic miR-29 antagonism promotes favorable plaque remodeling in atherosclerotic mice.

    PubMed

    Ulrich, Victoria; Rotllan, Noemi; Araldi, Elisa; Luciano, Amelia; Skroblin, Philipp; Abonnenc, Mélanie; Perrotta, Paola; Yin, Xiaoke; Bauer, Ashley; Leslie, Kristen L; Zhang, Pei; Aryal, Binod; Montgomery, Rusty L; Thum, Thomas; Martin, Kathleen; Suarez, Yajaira; Mayr, Manuel; Fernandez-Hernando, Carlos; Sessa, William C

    2016-01-01

    Abnormal remodeling of atherosclerotic plaques can lead to rupture, acute myocardial infarction, and death. Enhancement of plaque extracellular matrix (ECM) may improve plaque morphology and stabilize lesions. Here, we demonstrate that chronic administration of LNA-miR-29 into an atherosclerotic mouse model improves indices of plaque morphology. This occurs due to upregulation of miR-29 target genes of the ECM (col1A and col3A) resulting in reduced lesion size, enhanced fibrous cap thickness, and reduced necrotic zones. Sustained LNA-miR-29 treatment did not affect circulating lipids, blood chemistry, or ECM of solid organs including liver, lung, kidney, spleen, or heart. Collectively, these data support the idea that antagonizing miR-29 may promote beneficial plaque remodeling as an independent approach to stabilize vulnerable atherosclerotic lesions. PMID:27137489

  5. Serum cyclin-dependent kinase 9 is a potential biomarker of atherosclerotic inflammation

    PubMed Central

    Han, Yeming; Zhao, Shanshan; Gong, Yaoqin; Hou, Guihua

    2016-01-01

    Atherosclerotic coronary artery disease (CAD) is one of the most prevalent diseases worldwide. Atherosclerosis was considered to be the single most important contributor to CAD. In this study, a distinct serum protein expression pattern in CAD patients was demonstrated by proteomic analysis with two-dimensional gel electrophoresis coupled with mass spectrometry. In particular, CDK9 was found to be highly elevated in serum, monocytes and artery plaque samples of CAD patients. Furthermore, there was high infiltration of CD14+ monocytes/macrophages within artery plaques correlated with the expression of CDK9. Moreover, Flavopiridol (CDK9 inhibitor) could inhibit THP-1 cell (monocytic acute leukemia cell line) proliferation by targeting CDK9. Altogether, These findings indicate that CDK9 represent an important role for inflammation in the pathogenesis of atherosclerosis. It may be a potential biomarker of atherosclerotic inflammation and offer insights into the pathophysiology and targeted therapy for atherosclerotic CAD. PMID:26636538

  6. Genesis and growth of extracellular vesicle-derived microcalcification in atherosclerotic plaques

    PubMed Central

    Hutcheson, Joshua D.; Goettsch, Claudia; Bertazzo, Sergio; Maldonado, Natalia; Ruiz, Jessica L.; Goh, Wilson; Yabusaki, Katsumi; Faits, Tyler; Bouten, Carlijn; Franck, Gregory; Quillard, Thibaut; Libby, Peter; Aikawa, Masanori; Weinbaum, Sheldon; Aikawa, Elena

    2015-01-01

    Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the aggregation of calcifying extracellular vesicles, and the formation of microcalcifications and ultimately large calcification zones. We also show that calcification morphology and the plaque’s collagen content – two determinants of atherosclerotic plaque stability - are interlinked. PMID:26752654

  7. Mapping elasticity moduli of atherosclerotic plaque in situ via atomic force microscopy.

    PubMed

    Tracqui, Philippe; Broisat, Alexis; Toczek, Jackub; Mesnier, Nicolas; Ohayon, Jacques; Riou, Laurent

    2011-04-01

    Several studies have suggested that evolving mechanical stresses and strains drive atherosclerotic plaque development and vulnerability. Especially, stress distribution in the plaque fibrous capsule is an important determinant for the risk of vulnerable plaque rupture. Knowledge of the stiffness of atherosclerotic plaque components is therefore of critical importance. In this work, force mapping experiments using atomic force microscopy (AFM) were conducted in apolipoprotein E-deficient (ApoE(-/-)) mouse, which represents the most widely used experimental model for studying mechanisms underlying the development of atherosclerotic lesions. To obtain the elastic material properties of fibrous caps and lipidic cores of atherosclerotic plaques, serial cross-sections of aortic arch lesions were probed at different sites. Atherosclerotic plaque sub-structures were subdivided into cellular fibrotic, hypocellular fibrotic and lipidic rich areas according to histological staining. Hertz's contact mechanics were used to determine elasticity (Young's) moduli that were related to the underlying histological plaque structure. Cellular fibrotic regions exhibit a mean Young modulus of 10.4±5.7kPa. Hypocellular fibrous caps were almost six-times stiffer, with average modulus value of 59.4±47.4kPa, locally rising up to ∼250kPa. Lipid rich areas exhibit a rather large range of Young's moduli, with average value of 5.5±3.5kPa. Such precise quantification of plaque stiffness heterogeneity will allow investigators to have prospectively a better monitoring of atherosclerotic disease evolution, including arterial wall remodeling and plaque rupture, in response to mechanical constraints imposed by vascular shear stress and blood pressure.

  8. Vitamin A supplementation reduces IL-17 and RORc gene expression in atherosclerotic patients.

    PubMed

    Mottaghi, A; Ebrahimof, S; Angoorani, P; Saboor-Yaraghi, A-A

    2014-08-01

    Vitamin A is a potential mediator of T helper cells in atherosclerosis. The purpose of this study was to evaluate the effect of vitamin A supplementation on expression of Th17 cells-related IL-17 and RORc genes in atherosclerotic patients. Thirty one atherosclerotic patients and 15 healthy controls were studied for 4 months. Atherosclerotic patients were randomly divided into vitamin A or placebo groups. Healthy controls and patients in vitamin A group received 25,000 IU retinyl palmitate per day. Peripheral blood mononuclear cells were isolated, cultured and divided into three groups including fresh cells, phytohemagglutinin (PHA)-activated T cells and ox-LDL-activated T cells. Gene expressions of T cells were studied by real-time PCR. In atherosclerotic patients, vitamin A supplementation resulted in significant decrease in IL-17 gene expression by 0.63-fold in fresh cell, 0.82-fold in PHA-activated cells and 0.65-fold in ox-LDL-activated cells (P < 0.05 for all). RORc gene expression in fresh cells as well as ox-LDL-activated cells decreased significantly after vitamin A supplementation in atherosclerotic patients (P = 0.0001 for both). In PHA-activated cells, vitamin A supplementation significantly decreased RORc gene in both atherosclerotic patients and healthy subjects by 0.87-fold and 0.72, respectively, while in placebo group, the RORc gene expression significantly increased by 1.17-fold (P < 0.05 for all). Findings of this study suggest that vitamin A supplementation may be an effective approach to slow progression of atherosclerosis. PMID:24845870

  9. Bacterial Communities Associated with Atherosclerotic Plaques from Russian Individuals with Atherosclerosis

    PubMed Central

    Ziganshina, Elvira E.; Sharifullina, Dilyara M.; Lozhkin, Andrey P.; Khayrullin, Rustem N.; Ignatyev, Igor M.; Ziganshin, Ayrat M.

    2016-01-01

    Atherosclerosis is considered a chronic disease of the arterial wall and is the major cause of severe disease and death among individuals all over the world. Some recent studies have established the presence of bacteria in atherosclerotic plaque samples and suggested their possible contribution to the development of cardiovascular disease. The main objective of this preliminary pilot study was to better understand the bacterial diversity and abundance in human atherosclerotic plaques derived from common carotid arteries of individuals with atherosclerosis (Russian nationwide group) and contribute towards the further identification of a main group of atherosclerotic plaque bacteria by 454 pyrosequencing their 16S ribosomal RNA (16S rRNA) genes. The applied approach enabled the detection of bacterial DNA in all atherosclerotic plaques. We found that distinct members of the order Burkholderiales were present at high levels in all atherosclerotic plaques obtained from patients with atherosclerosis with the genus Curvibacter being predominant in all plaque samples. Moreover, unclassified Burkholderiales as well as members of the genera Propionibacterium and Ralstonia were typically the most significant taxa for all atherosclerotic plaques. Other genera such as Burkholderia, Corynebacterium and Sediminibacterium as well as unclassified Comamonadaceae, Oxalobacteraceae, Rhodospirillaceae, Bradyrhizobiaceae and Burkholderiaceae were always found but at low relative abundances of the total 16S rRNA gene population derived from all samples. Also, we found that some bacteria found in plaque samples correlated with some clinical parameters, including total cholesterol, alanine aminotransferase and fibrinogen levels. Finally, our study indicates that some bacterial agents at least partially may be involved in affecting the development of cardiovascular disease through different mechanisms. PMID:27736997

  10. Intra- and extracranial atherosclerotic disease: casting a new light on emerging trends.

    PubMed

    Ding, Jing; Wang, Xin

    2016-10-01

    Intra- and extracranial atherosclerotic stenosis has been shown to be associated with an increased risk of secondary stroke mortality. Advances in invasive and non-invasive imaging modalities have improved analysis of hemodynamic changes and allowed better delineation of the integrity of intracranial collateralization and plague morphology in patients with artery stenosis. This review focuses on new imaging modalities and clinical applications of currently available techniques, and provides significant insight into future directions in comprehensive analysis of intra- and extracranial atherosclerotic stenosis. PMID:27367590

  11. Renovascular heart failure: heart failure in patients with atherosclerotic renal artery disease.

    PubMed

    Kawarada, Osami; Yasuda, Satoshi; Noguchi, Teruo; Anzai, Toshihisa; Ogawa, Hisao

    2016-07-01

    Atherosclerotic renal artery disease presents with a broad spectrum of clinical features, including heart failure as well as hypertension, and renal failure. Although recent randomized controlled trials failed to demonstrate renal artery stenting can reduce blood pressure or the number of cardiovascular or renal events more so than medical therapy, increasing attention has been paid to flash pulmonary edema and congestive heart failure associated with atherosclerotic renal artery disease. This clinical entity "renovascular heart failure" is diagnosed retrospectively. Given the increasing global burden of heart failure, this review highlights the background and catheter-based therapeutic aspects for renovascular heart failure.

  12. Characterization of atherosclerotic plaques by cross-polarization optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Gubarkova, Ekaterina V.; Dudenkova, Varvara V.; Feldchtein, Felix I.; Timofeeva, Lidia B.; Kiseleva, Elena B.; Kuznetsov, Sergei S.; Moiseev, Alexander A.; Gelikonov, Gregory V.; Vitkin, Alex I.; Gladkova, Natalia D.

    2016-02-01

    We combined cross-polarization optical coherence tomography (CP OCT) and non-linear microscopy based on second harmonic generation (SHG) and two-photon-excited fluorescence (2PEF) to assess collagen and elastin fibers in the development of the atherosclerotic plaque (AP). The study shows potential of CP OCT for the assessment of collagen and elastin fibers condition in atherosclerotic arteries. Specifically, the additional information afforded by CP OCT, related to birefringence and cross-scattering properties of arterial tissues, may improve the robustness and accuracy of assessment about the microstructure and composition of the plaque for different stages of atherosclerosis.

  13. Specific imaging of atherosclerotic plaque lipids with two-wavelength intravascular photoacoustics

    PubMed Central

    Wu, Min; Jansen, Krista; van der Steen, Antonius F. W.; van Soest, Gijs

    2015-01-01

    The lipid content in plaques is an important marker for identifying atherosclerotic lesions and disease states. Intravascular photoacoustic (IVPA) imaging can be used to visualize lipids in the artery. In this study, we further investigated lipid detection in the 1.7-µm spectral range. By exploiting the relative difference between the IVPA signal strengths at 1718 and 1734 nm, we could successfully detect and differentiate between the plaque lipids and peri-adventitial fat in human coronary arteries ex vivo. Our study demonstrates that IVPA imaging can positively identify atherosclerotic plaques using only two wavelengths, which could enable rapid data acquisition in vivo. PMID:26417500

  14. Accelerating the performance of a novel meshless method based on collocation with radial basis functions by employing a graphical processing unit as a parallel coprocessor

    NASA Astrophysics Data System (ADS)

    Owusu-Banson, Derek

    In recent times, a variety of industries, applications and numerical methods including the meshless method have enjoyed a great deal of success by utilizing the graphical processing unit (GPU) as a parallel coprocessor. These benefits often include performance improvement over the previous implementations. Furthermore, applications running on graphics processors enjoy superior performance per dollar and performance per watt than implementations built exclusively on traditional central processing technologies. The GPU was originally designed for graphics acceleration but the modern GPU, known as the General Purpose Graphical Processing Unit (GPGPU) can be used for scientific and engineering calculations. The GPGPU consists of massively parallel array of integer and floating point processors. There are typically hundreds of processors per graphics card with dedicated high-speed memory. This work describes an application written by the author, titled GaussianRBF to show the implementation and results of a novel meshless method that in-cooperates the collocation of the Gaussian radial basis function by utilizing the GPU as a parallel co-processor. Key phases of the proposed meshless method have been executed on the GPU using the NVIDIA CUDA software development kit. Especially, the matrix fill and solution phases have been carried out on the GPU, along with some post processing. This approach resulted in a decreased processing time compared to similar algorithm implemented on the CPU while maintaining the same accuracy.

  15. Introducing the fission-fusion reaction process: using a laser-accelerated Th beam to produce neutron-rich nuclei towards the N=126 waiting point of the r-process

    NASA Astrophysics Data System (ADS)

    Habs, D.; Thirolf, P. G.; Gross, M.; Allinger, K.; Bin, J.; Henig, A.; Kiefer, D.; Ma, W.; Schreiber, J.

    2011-05-01

    We propose to produce neutron-rich nuclei in the range of the astrophysical r-process (the rapid neutron-capture process) around the waiting point N=126 (Kratz et al. in Prog. Part. Nucl. Phys. 59:147, 2007; Arnould et al. in Phys. Rep. 450:97, 2007; Panov and Janka in Astron. Astrophys. 494:829, 2009) by fissioning a dense laser-accelerated thorium ion bunch in a thorium target (covered by a polyethylene layer, CH2), where the light fission fragments of the beam fuse with the light fission fragments of the target. Using the `hole-boring' (HB) mode of laser radiation pressure acceleration (RPA) (Robinson et al. in Plasma Phys. Control. Fusion 51:024004, 2009; Henig et al. in Phys. Rev. Lett. 103:245003, 2009; Tajima et al. in Rev. Accel. Sci. Technol. 2:221, 2009) using a high-intensity, short pulse laser, bunches of 232Th with solid-state density can be generated very efficiently from a Th layer (ca. 560 nm thick), placed beneath a deuterated polyethylene foil (CD2 with ca. 520 nm), both forming the production target. Th ions laser-accelerated to about 7 MeV/u will pass through a thin CH2 layer placed in front of a thicker second Th foil (both forming the reaction target) closely behind the production target and disintegrate into light and heavy fission fragments. In addition, light ions (d,C) from the CD2 production target will be accelerated as well to about 7 MeV/u, also inducing the fission process of 232Th in the second Th layer. The laser-accelerated ion bunches with solid-state density, which are about 1014 times more dense than classically accelerated ion bunches, allow for a high probability that generated fission products can fuse again when the fragments from the thorium beam strike the Th layer of the reaction target. In contrast to classical radioactive beam facilities, where intense but low-density radioactive beams of one ion species are merged with stable targets, the novel fission-fusion process draws on the fusion between neutron-rich, short

  16. Nature of hyperacute (accelerated second set) rejection in dog renal allografts and effects of heparin on rejection process.

    PubMed

    Amery, A H; Pegrum, G D; Risdon, R A; Williams, G

    1973-02-24

    Renal allografts were exchanged between unrelated mongrel dogs after previous sensitization with skin and kidney grafts from the same donors. Rapid rejection of the renal allografts was associated with the accumulation of platelets and leucocytes in the peritubular and glomerular capillaries but fibrin deposition was not demonstrated.Heparin infusion delayed but did not prevent the rejection process.

  17. Real-time atmospheric imaging and processing with hybrid adaptive optics and hardware accelerated lucky-region fusion (LRF) algorithm

    NASA Astrophysics Data System (ADS)

    Liu, Jony Jiang; Carhart, Gary W.; Beresnev, Leonid A.; Aubailly, Mathieu; Jackson, Christopher R.; Ejzak, Garrett; Kiamilev, Fouad E.

    2014-09-01

    Atmospheric turbulences can significantly deteriorate the performance of long-range conventional imaging systems and create difficulties for target identification and recognition. Our in-house developed adaptive optics (AO) system, which contains high-performance deformable mirrors (DMs) and the fast stochastic parallel gradient decent (SPGD) control mechanism, allows effective compensation of such turbulence-induced wavefront aberrations and result in significant improvement on the image quality. In addition, we developed advanced digital synthetic imaging and processing technique, "lucky-region" fusion (LRF), to mitigate the image degradation over large field-of-view (FOV). The LRF algorithm extracts sharp regions from each image obtained from a series of short exposure frames and fuses them into a final improved image. We further implemented such algorithm into a VIRTEX-7 field programmable gate array (FPGA) and achieved real-time video processing. Experiments were performed by combining both AO and hardware implemented LRF processing technique over a near-horizontal 2.3km atmospheric propagation path. Our approach can also generate a universal real-time imaging and processing system with a general camera link input, a user controller interface, and a DVI video output.

  18. The Acceleration of Spoken-Word Processing in Children's Native-Language Acquisition: An ERP Cohort Study

    ERIC Educational Resources Information Center

    Ojima, Shiro; Matsuba-Kurita, Hiroko; Nakamura, Naoko; Hagiwara, Hiroko

    2011-01-01

    Healthy adults can identify spoken words at a remarkable speed, by incrementally analyzing word-onset information. It is currently unknown how this adult-level speed of spoken-word processing emerges during children's native-language acquisition. In a picture-word mismatch paradigm, we manipulated the semantic congruency between picture contexts…

  19. Generic chromatography-based purification strategies accelerate the development of downstream processes for biopharmaceutical proteins produced in plants.

    PubMed

    Buyel, Johannes F; Fischer, Rainer

    2014-04-01

    Plants offer a valuable alternative to cultured mammalian cells for the production of recombinant biopharmaceutical proteins. However, the target protein typically represents only a minor fraction of the total protein in the initial plant extract, which means that the development of product-specific chromatography-based purification strategies is often laborious and expensive. To address this challenge, we designed a generic downstream process that is suitable for the purification of recombinant proteins with diverse properties from plant production platforms. This was achieved by focusing on the binding behavior of tobacco host cell proteins (HCPs) to a broad set of chromatography resins under different pH and conductivity conditions. Strong cation exchanger and salt-tolerant anion exchanger resins exhibited the best resolution of tobacco HCPs among the 13 tested resins, and their selectivity was easy to manipulate through the adjustment of pH and conductivity. The advantages, such as direct capture of a target protein from leaf extract, and limitations, such as low binding capacity, of various chromatography ligands and resins are discussed. We also address the most useful applications of the chromatography ligands, namely recovery of proteins with a certain pI, in a downstream process that aims to purify diverse plant-derived biopharmaceutical proteins. Based on these results, we describe generic purification schemes that are suitable for acidic, neutral, and basic target proteins, as a first step toward the development of industrial platform processes.

  20. Generic chromatography-based purification strategies accelerate the development of downstream processes for biopharmaceutical proteins produced in plants.

    PubMed

    Buyel, Johannes F; Fischer, Rainer

    2014-04-01

    Plants offer a valuable alternative to cultured mammalian cells for the production of recombinant biopharmaceutical proteins. However, the target protein typically represents only a minor fraction of the total protein in the initial plant extract, which means that the development of product-specific chromatography-based purification strategies is often laborious and expensive. To address this challenge, we designed a generic downstream process that is suitable for the purification of recombinant proteins with diverse properties from plant production platforms. This was achieved by focusing on the binding behavior of tobacco host cell proteins (HCPs) to a broad set of chromatography resins under different pH and conductivity conditions. Strong cation exchanger and salt-tolerant anion exchanger resins exhibited the best resolution of tobacco HCPs among the 13 tested resins, and their selectivity was easy to manipulate through the adjustment of pH and conductivity. The advantages, such as direct capture of a target protein from leaf extract, and limitations, such as low binding capacity, of various chromatography ligands and resins are discussed. We also address the most useful applications of the chromatography ligands, namely recovery of proteins with a certain pI, in a downstream process that aims to purify diverse plant-derived biopharmaceutical proteins. Based on these results, we describe generic purification schemes that are suitable for acidic, neutral, and basic target proteins, as a first step toward the development of industrial platform processes. PMID:24478119

  1. From Cleanup to Stewardship. A companion report to Accelerating Cleanup: Paths to Closure and background information to support the scoping process required for the 1998 PEIS Settlement Study

    SciTech Connect

    1999-10-01

    Long-term stewardship is expected to be needed at more than 100 DOE sites after DOE's Environmental Management program completes disposal, stabilization, and restoration operations to address waste and contamination resulting from nuclear research and nuclear weapons production conducted over the past 50 years. From Cleanup to stewardship provides background information on the Department of Energy (DOE) long-term stewardship obligations and activities. This document begins to examine the transition from cleanup to long-term stewardship, and it fulfills the Secretary's commitment to the President in the 1999 Performance Agreement to provide a companion report to the Department's Accelerating Cleanup: Paths to Closure report. It also provides background information to support the scoping process required for a study on long-term stewardship required by a 1998 Settlement Agreement.

  2. Freeze-drying simulation framework coupling product attributes and equipment capability: toward accelerating process by equipment modifications.

    PubMed

    Ganguly, Arnab; Alexeenko, Alina A; Schultz, Steven G; Kim, Sherry G

    2013-10-01

    A physics-based model for the sublimation-transport-condensation processes occurring in pharmaceutical freeze-drying by coupling product attributes and equipment capabilities into a unified simulation framework is presented. The system-level model is used to determine the effect of operating conditions such as shelf temperature, chamber pressure, and the load size on occurrence of choking for a production-scale dryer. Several data sets corresponding to production-scale runs with a load from 120 to 485 L have been compared with simulations. A subset of data is used for calibration, whereas another data set corresponding to a load of 150 L is used for model validation. The model predictions for both the onset and extent of choking as well as for the measured product temperature agree well with the production-scale measurements. Additionally, we study the effect of resistance to vapor transport presented by the duct with a valve and a baffle in the production-scale freeze-dryer. Computation Fluid Dynamics (CFD) techniques augmented with a system-level unsteady heat and mass transfer model allow to predict dynamic process conditions taking into consideration specific dryer design. CFD modeling of flow structure in the duct presented here for a production-scale freeze-dryer quantifies the benefit of reducing the obstruction to the flow through several design modifications. It is found that the use of a combined valve-baffle system can increase vapor flow rate by a factor of 2.2. Moreover, minor design changes such as moving the baffle downstream by about 10 cm can increase the flow rate by 54%. The proposed design changes can increase drying rates, improve efficiency, and reduce cycle times due to fewer obstructions in the vapor flow path. The comprehensive simulation framework combining the system-level model and the detailed CFD computations can provide a process analytical tool for more efficient and robust freeze-drying of bio-pharmaceuticals.

  3. Particle acceleration

    NASA Technical Reports Server (NTRS)

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  4. Accelerated Achievement

    ERIC Educational Resources Information Center

    Ford, William J.

    2010-01-01

    This article focuses on the accelerated associate degree program at Ivy Tech Community College (Indiana) in which low-income students will receive an associate degree in one year. The three-year pilot program is funded by a $2.3 million grant from the Lumina Foundation for Education in Indianapolis and a $270,000 grant from the Indiana Commission…

  5. ACCELERATION INTEGRATOR

    DOEpatents

    Pope, K.E.

    1958-01-01

    This patent relates to an improved acceleration integrator and more particularly to apparatus of this nature which is gyrostabilized. The device may be used to sense the attainment by an airborne vehicle of a predetermined velocitv or distance along a given vector path. In its broad aspects, the acceleration integrator utilizes a magnetized element rotatable driven by a synchronous motor and having a cylin drical flux gap and a restrained eddy- current drag cap deposed to move into the gap. The angular velocity imparted to the rotatable cap shaft is transmitted in a positive manner to the magnetized element through a servo feedback loop. The resultant angular velocity of tae cap is proportional to the acceleration of the housing in this manner and means may be used to measure the velocity and operate switches at a pre-set magnitude. To make the above-described dcvice sensitive to acceleration in only one direction the magnetized element forms the spinning inertia element of a free gyroscope, and the outer housing functions as a gimbal of a gyroscope.

  6. Plasma accelerator

    DOEpatents

    Wang, Zhehui; Barnes, Cris W.

    2002-01-01

    There has been invented an apparatus for acceleration of a plasma having coaxially positioned, constant diameter, cylindrical electrodes which are modified to converge (for a positive polarity inner electrode and a negatively charged outer electrode) at the plasma output end of the annulus between the electrodes to achieve improved particle flux per unit of power.

  7. Accelerating resolution-of-the-identity second-order Møller-Plesset quantum chemistry calculations with graphical processing units.

    PubMed

    Vogt, Leslie; Olivares-Amaya, Roberto; Kermes, Sean; Shao, Yihan; Amador-Bedolla, Carlos; Aspuru-Guzik, Alan

    2008-03-13

    The modification of a general purpose code for quantum mechanical calculations of molecular properties (Q-Chem) to use a graphical processing unit (GPU) is reported. A 4.3x speedup of the resolution-of-the-identity second-order Møller-Plesset perturbation theory (RI-MP2) execution time is observed in single point energy calculations of linear alkanes. The code modification is accomplished using the compute unified basic linear algebra subprograms (CUBLAS) library for an NVIDIA Quadro FX 5600 graphics card. Furthermore, speedups of other matrix algebra based electronic structure calculations are anticipated as a result of using a similar approach.

  8. Identifying Vulnerable Atherosclerotic Plaque in Rabbits Using DMSA-USPIO Enhanced Magnetic Resonance Imaging to Investigate the Effect of Atorvastatin

    PubMed Central

    Li, Dongye; Wu, Weiheng; Gong, Lei; Li, Yong; Zhang, Qingdui; Zhang, Tao; Zhang, Chao; Zhang, Yu

    2015-01-01

    Background Rupture of an atherosclerotic plaque is the primary cause of acute cardiovascular and cerebrovascular syndromes. Early and non-invasive detection of vulnerable atherosclerotic plaques (VP) would be significant in preventing some aspects of these syndromes. As a new contrast agent, dimercaptosuccinic acid (DMSA) modified ultra-small super paramagnetic iron oxide (USPIO) was synthesized and used to identify VP and rupture plaque by magnetic resonance imaging (MRI). Methods Atherosclerosis was induced in male New Zealand White rabbits by feeding a high cholesterol diet (n = 30). Group A with atherosclerosis plaque (n = 10) were controls. VP was established in groups B (n = 10) and C (n = 10) using balloon-induced endothelial injury of the abdominal aorta. Adenovirus-carrying p53 genes were injected into the aortic segments rich in plaques after 8 weeks. Group C was treated with atorvastatin for 8 weeks. Sixteen weeks later, all rabbits underwent pharmacological triggering, and imaging were taken daily for 5 d after DMSA-USPIO infusion. At the first day and before being killed, serum MMP-9, sCD40L, and other lipid indicators were measured. Results DMSA-USPIO particles accumulated in VP and rupture plaques. Rupture plaques appeared as areas of hyper-intensity on DMSA-USPIO enhanced MRI, especially T2*-weighted sequences, with a signal strength peaking at 96 h. The group given atorvastatin showed few DMSA-USPIO particles and had lower levels of serum indicators. MMP-9 and sCD40L levels in group B were significantly higher than in the other 2 groups (P <0.05). Conclusion After successfully establishing a VP model in rabbits, DMSA-USPIO was used to enhance MRI for clear identification of plaque inflammation and rupture. Rupture plaques were detectable in this way probably due to an activating inflammatory process. Atorvastatin reduced the inflammatory response and stabilizing VP possibly by decreasing MMP-9 and sCD40L levels. PMID:25973795

  9. Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

    DOEpatents

    Kansa, Edward J.; Wijesinghe, Ananda M.; Viani, Brian E.

    1997-01-01

    The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculents and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude.

  10. Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

    DOEpatents

    Kansa, E.J.; Wijesinghe, A.M.; Viani, B.E.

    1997-01-14

    The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculants and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude. 8 figs.

  11. Graphics processing unit accelerated three-dimensional model for the simulation of pulsed low-temperature plasmas

    SciTech Connect

    Fierro, Andrew Dickens, James; Neuber, Andreas

    2014-12-15

    A 3-dimensional particle-in-cell/Monte Carlo collision simulation that is fully implemented on a graphics processing unit (GPU) is described and used to determine low-temperature plasma characteristics at high reduced electric field, E/n, in nitrogen gas. Details of implementation on the GPU using the NVIDIA Compute Unified Device Architecture framework are discussed with respect to efficient code execution. The software is capable of tracking around 10 × 10{sup 6} particles with dynamic weighting and a total mesh size larger than 10{sup 8} cells. Verification of the simulation is performed by comparing the electron energy distribution function and plasma transport parameters to known Boltzmann Equation (BE) solvers. Under the assumption of a uniform electric field and neglecting the build-up of positive ion space charge, the simulation agrees well with the BE solvers. The model is utilized to calculate plasma characteristics of a pulsed, parallel plate discharge. A photoionization model provides the simulation with additional electrons after the initial seeded electron density has drifted towards the anode. Comparison of the performance benefits between the GPU-implementation versus a CPU-implementation is considered, and a speed-up factor of 13 for a 3D relaxation Poisson solver is obtained. Furthermore, a factor 60 speed-up is realized for parallelization of the electron processes.

  12. VCAM-1-targeting gold nanoshell probe for photoacoustic imaging of atherosclerotic plaque in mice.

    PubMed

    Rouleau, Leonie; Berti, Romain; Ng, Vanessa W K; Matteau-Pelletier, Carl; Lam, Tina; Saboural, Pierre; Kakkar, Ashok K; Lesage, Frédéric; Rhéaume, Eric; Tardif, Jean-Claude

    2013-01-01

    The development of molecular probes and novel imaging modalities, allowing better resolution and specificity, is associated with an increased potential for molecular imaging of atherosclerotic plaques especially in basic and pre-clinical research applications. In that context, a photoacoustic molecular probe based on gold nanoshells targeting VCAM-1 in mice (immunonanoshells) was designed. The molecular probe was validated in vitro and in vivo, showing no noticeable acute toxic effects. We performed the conjugation of gold nanoshells displaying near-infrared absorption properties with VCAM-1 antibody molecules and PEG to increase their biocompatibility. The resulting immunonanoshells obtained under different conditions of conjugation were then assessed for specificity and sensitivity. Photoacoustic tomography was performed to determine the ability to distinguish gold nanoshells from blood both in phantoms and in vivo. Ex vivo optical projection tomography of hearts and aortas from atherosclerotic and control mice confirmed the selective accumulation of the immunonanoshells in atherosclerotic-prone regions in mice, thus validating the utility of the probe in vivo in small animals for pre-clinical research. These immunonanoshells represent an adequate mean to target atherosclerotic plaques in small animals, leading to new tools to follow the effect of therapies on the progression or regression of the disease. PMID:23109390

  13. Low expression of ferroxidases is implicated in the iron retention in human atherosclerotic plaques.

    PubMed

    Ji, Jiajie; Zhou, Yu; Hao, Shuangying; Wang, Qi; Li, Kuanyu; Qiao, Tong

    2015-09-01

    The effect of iron on the progress of atherosclerosis is still controversial. To explore the relationship between atherosclerotic plaques and iron metabolism and how iron is accumulated in plaque macrophages, we performed Oil red O staining to detect the lipid of the atherosclerotic plaques, enzyme-linked immunosorbent assay to detect the intracellular lipids (total cholesterol, free cholesterol) and serum hepcidin, Western-blot to examine the iron-related proteins, immunohistochemical and immunofluorescence assays to localize ferroportin 1 in macrophages. The contents of serum iron and transferrin saturation were measured. The results confrimed that atherosclerotic plaques were all lipid-rich. Compared to normal vessel wall, atherosclerotic plaques had significantly higher levels of ferritin and ferroportin 1. Strikingly, we found the much lower levels of ferroxidases ceruloplasmin and hephaestin in plaque tissue than the normal vessel, while the content of serum hepcidin, iron and transferrin saturation were similar in these two groups. The novel finding suggests that the inability of ferrous iron to be oxidized into ferric iron might be a potential mechanism for iron retention in plaques. PMID:26208458

  14. Detection of atherosclerotic lesions and intimal macrophages using CD36-targeted nanovesicles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current approaches to the diagnosis and therapy of atherosclerosis cannot target to lesion-determinant cells in the artery wall. Intimal macrophage infiltration promotes atherosclerotic lesion development by facilitating the accumulation of oxidized low-density lipoproteins (oxLDL) and increasing in...

  15. Prednisolone-containing liposomes accumulate in human atherosclerotic macrophages upon intravenous administration

    PubMed Central

    van der Valk, Fleur M.; van Wijk, Diederik F.; Lobatto, Mark E.; Verberne, Hein J.; Storm, Gert; Willems, Martine C.M.; Legemate, Dink A.; Nederveen, Aart J.; Calcagno, Claudia; Mani, Venkatesh; Ramachandran, Sarayu; Paridaans, Maarten P.M.; Otten, Maarten J.; Dallinga-Thie, Geesje M.; Fayad, Zahi A.; Nieuwdorp, Max; Schulte, Dominik M.; Metselaar, Josbert M.; Mulder, Willem J.M.; Stroes, Erik S.

    2015-01-01

    Drug delivery to atherosclerotic plaques via liposomal nanoparticles may improve therapeutic agents’ risk–benefit ratios. Our paper details the first clinical studies of a liposomal nanoparticle encapsulating prednisolone (LN-PLP) in atherosclerosis. First, PLP’s liposomal encapsulation improved its pharmacokinetic profile in humans (n = 13) as attested by an increased plasma half-life of 63 h (LN-PLP 1.5 mg/kg). Second, intravenously infused LN-PLP appeared in 75% of the macrophages isolated from iliofemoral plaques of patients (n = 14) referred for vascular surgery in a randomized, placebo-controlled trial. LN-PLP treatment did however not reduce arterial wall permeability or inflammation in patients with atherosclerotic disease (n = 30), as assessed by multimodal imaging in a subsequent randomized, placebo-controlled study. In conclusion, we successfully delivered a long-circulating nanoparticle to atherosclerotic plaque macrophages in patients, whereas prednisolone accumulation in atherosclerotic lesions had no anti-inflammatory effect. Nonetheless, the present study provides guidance for development and imaging-assisted evaluation of future nanomedicine in atherosclerosis. PMID:25791806

  16. Characterization of atherosclerotic arterial tissue using combined SHG and FLIM microscopy

    NASA Astrophysics Data System (ADS)

    Cicchi, Riccardo; Baria, Enrico; Matthäus, Christian; Lange, Marta; Lattermann, Annika; Brehm, Bernhard R.; Popp, Jürgen; Pavone, Francesco S.

    2015-07-01

    Atherosclerosis is among the most widespread cardiovascular diseases and one of the leading cause of death in the Western World. Characterization of arterial tissue in atherosclerotic condition is extremely interesting from the diagnostic point of view, especially for what is concerning collagen content and organization because collagen plays a crucial role in plaque vulnerability. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires immunehistochemical examination and a morpho-functional approach. Non-linear microscopy techniques offer the potential for providing morpho-functional information on the examined tissues in a label-free way. In this study, we employed combined SHG and FLIM microscopy for characterizing collagen organization in both normal arterial wall and within atherosclerotic plaques. Image pattern analysis of SHG images allowed characterizing collagen organization in different tissue regions. In addition, the analysis of collagen fluorescence decay contributed to the characterization of the samples based on collagen fluorescence lifetime. Different values of collagen fiber mean size, collagen distribution, and collagen anisotropy and collagen fluorescence lifetime were found in normal arterial wall and within plaque depositions, prospectively allowing for automated classification of atherosclerotic lesions and plaque vulnerability. The presented method represents a promising diagnostic tool for evaluating atherosclerotic tissue and has the potential to find a stable place in clinical setting as well as to be applied in vivo in the near future.

  17. Non-linear imaging and characterization of atherosclerotic arterial tissue using combined SHG and FLIM microscopy

    NASA Astrophysics Data System (ADS)

    Cicchi, Riccardo; Matthäus, Christian; Meyer, Tobias; Lattermann, Annika; Dietzek, Benjamin; Brehm, Bernhard R.; Popp, Jürgen; Pavone, Francesco S.

    2015-03-01

    Atherosclerosis is among the most widespread cardiovascular diseases and one of the leading cause of death in the Western World. Characterization of arterial tissue in atherosclerotic condition is extremely interesting from the diagnostic point of view, especially for what is concerning collagen content and organization because collagen plays a crucial role in plaque vulnerability. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires immune-histochemical examination and a morpho-functional approach. Non-linear microscopy techniques offer the potential for providing morpho-functional information on the examined tissues in a label-free way. In this study, we employed combined SHG and FLIM microscopy for characterizing collagen organization in both normal arterial wall and within atherosclerotic plaques. Image pattern analysis of SHG images allowed characterizing collagen organization in different tissue regions. In addition, the analysis of collagen fluorescence decay contributed to the characterization of the samples on the basis of collagen fluorescence lifetime. Different values of collagen fiber mean size, collagen distribution, collagen anisotropy and collagen fluorescence lifetime were found in normal arterial wall and within plaque depositions, prospectively allowing for automated classification of atherosclerotic lesions and plaque vulnerability. The presented method represents a promising diagnostic tool for evaluating atherosclerotic tissue and has the potential to find a stable place in clinical setting as well as to be applied in vivo in the near future.

  18. Combined imaging of oxidative stress and microscopic structure reveals new features in human atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

    Lilledahl, Magnus B.; Gustafsson, Håkan; Ellingsen, Pål Gunnar; Zachrisson, Helene; Hallbeck, Martin; Hagen, Vegard Stenhjem; Kildemo, Morten; Lindgren, Mikael

    2015-02-01

    Human atherosclerotic samples collected by carotid endarterectomy were investigated using electronic paramagnetic resonance imaging (EPRI) for visualization of reactive oxygen species, and nonlinear optical microscopy (NLOM) to study structural features. Regions of strong EPRI signal, indicating a higher concentration of reactive oxygen species and increased inflammation, were found to colocalize with regions dense in cholesterol crystals as revealed by NLOM.

  19. Detection of Fungal Elements in Atherosclerotic Plaques Using Mycological, Pathological and Molecular Methods

    PubMed Central

    MASOUMI, Omid; SHAHZADI, Mahmoud; KORDBACHEH, Parivash; ZAINI, Farideh; MAHMOUDI, Shahram; MAHMOUDI, Mahmoud; BAHREINI, Hesamoddin; SAFARA, Mahin; MIRHENDI, Hossein

    2015-01-01

    Background: The aim of this study was to detect fungi in atherosclerotic plaques and investigate their possible role in atherosclerosis. Methods: Coronary atherosclerotic plaques specimen were obtained from patients with atherosclerosis. Direct examination, culture, histopathology study, PCR and sequencing were performed to detect/identify the mycotic elements in the plaques. Age, sex, smoking, obesity, hypertension, hyperlipidemia, family history of heart diseases and diabetes were considered and data were analyzed using Chi Square test by SPSS version 15. Results: A total of 41 specimens were analyzed. Direct examination for fungal elements was negative in all cases but in culture only one specimen grew as a mold colony. The presence of fungal elements were confirmed in 6 and 2 tissue sections stained by Gomori methenamine silver and Hematoxylin and Eosin methods, respectively. Using PCR, 11 cases were positive for fungi. The DNA sequence analysis of six positive specimens which were randomly selected revealed fungi as Candida albicans (n=3), Candida guilliermondii (n=2) and Monilia sp. (n=1). Conclusion: A significant association between the presence of fungi in atherosclerotic plaques and severity of atherogenesis and atherosclerotic disease was not found. This could be due to limited numbers of patients included in our study. However, the presence of fungal elements in 26.8% of our specimens is considerable and the results does not exclude the correlation between the presence of fungi with atherosclerosis and coronary artery disease. PMID:26587476

  20. Distinct metabolic and vascular effects of dietary triglycerides and cholesterol in atherosclerotic and diabetic mouse models.

    PubMed

    Laplante, Marc-André; Charbonneau, Alexandre; Avramoglu, Rita Kohen; Pelletier, Patricia; Fang, Xiangping; Bachelard, Hélène; Ylä-Herttuala, Seppo; Laakso, Markku; Després, Jean-Pierre; Deshaies, Yves; Sweeney, Gary; Mathieu, Patrick; Marette, André

    2013-09-01

    Cholesterol and triglyceride-rich Western diets are typically associated with an increased occurrence of type 2 diabetes and vascular diseases. This study aimed to assess the relative impact of dietary cholesterol and triglycerides on glucose tolerance, insulin sensitivity, atherosclerotic plaque formation, and endothelial function. C57BL6 wild-type (C57) mice were compared with atherosclerotic LDLr(-/-) ApoB(100/100) (LRKOB100) and atherosclerotic/diabetic IGF-II × LDLr(-/-) ApoB(100/100) (LRKOB100/IGF) mice. Each group was fed either a standard chow diet, a 0.2% cholesterol diet, a high-fat diet (HFD), or a high-fat 0.2% cholesterol diet for 6 mo. The triglyceride-rich HFD increased body weight, glucose intolerance, and insulin resistance but did not alter endothelial function or atherosclerotic plaque formation. Dietary cholesterol, however, increased plaque formation in LRKOB100 and LRKOB100/IGF animals and decreased endothelial function regardless of genotype. However, cholesterol was not associated with an increase of insulin resistance in LRKOB100 and LRKOB100/IGF mice and, unexpectedly, was even found to reduce the insulin-resistant effect of dietary triglycerides in these animals. Our data indicate that dietary triglycerides and cholesterol have distinct metabolic and vascular effects in obese atherogenic mouse models resulting in dissociation between the impairment of glucose homeostasis and the development of atherosclerosis.

  1. In Vitro High-Throughput RNAi Screening to Accelerate the Process of Target Identification and Drug Development.

    PubMed

    Yin, Hongwei; Kassner, Michelle

    2016-01-01

    High-throughput RNA interference (HT-RNAi) is a powerful tool that can be used to knock down gene expression in order to identify novel genes and pathways involved in many cellular processes. It is a systematic, yet unbiased, approach to identify essential or synthetic lethal genes that promote cell survival in diseased cells as well as genes that confer resistance or sensitivity to drug treatment. This information serves as a foundation for enhancing current treatments for cancer and other diseases by identifying new drug targets, uncovering potential combination therapies, and helping clinicians match patients with the most effective treatment based on genetic information. Here, we describe the method of performing an in vitro HT-RNAi screen using chemically synthesized siRNA. PMID:27581290

  2. Interleukin 10-coated nanoparticle systems compared for molecular imaging of atherosclerotic lesions

    PubMed Central

    Almer, Gunter; Summers, Kelli L; Scheicher, Bernhard; Kellner, Josef; Stelzer, Ingeborg; Leitinger, Gerd; Gries, Anna; Prassl, Ruth; Zimmer, Andreas; Mangge, Harald

    2014-01-01

    Atherosclerosis (AS) is one of the leading causes of mortality in high-income countries. Early diagnosis of vulnerable atherosclerotic lesions is one of the biggest challenges currently facing cardiovascular medicine. The present study focuses on developing targeted nanoparticles (NPs) in order to improve the detection of vulnerable atherosclerotic-plaques. Various biomarkers involved in the pathogenesis of atherosclerotic-plaques have been identified and one of these promising candidates for diagnostic targeting is interleukin 10 (IL10). IL10 has been shown to be a key anti-inflammatory responding cytokine in the early stages of atherogenesis, and has already been used for therapeutic interventions in humans and mice. IL10, the targeting sequence, was coupled to two different types of NPs: protamine-oligonucleotide NPs (proticles) and sterically stabilized liposomes in order to address the question of whether the recognition and detection of atherosclerotic-lesions is primarily determined by the targeting sequence itself, or whether it depends on the NP carrier system to which the biomarker is coupled. Each IL10-targeted NP was assessed based on its sensitivity and selectivity toward characterizing atherosclerotic-plaque lesions using an apolipoprotein E-deficient mouse as the model of atherosclerosis. Aortas from apolipoprotein E-deficient mice fed a high fat diet, were stained with either fluorescence-labeled IL10 or IL10-coupled NPs. Ex vivo imaging was performed using confocal laser-scanning microscopy. We found that IL10-targeted proticles generated a stronger signal by accumulating at the surface of atherosclerotic-plaques, while IL10-targeted, sterically stabilized liposomes showed a staining pattern deeper in the plaque compared to the fluorescence-labeled IL10 alone. Our results point to a promising route for enhanced in vivo imaging using IL10-targeted NPs. NPs allow a higher payload of signal emitting molecules to be delivered to the atherosclerotic

  3. Automatic plaque characterization and vessel wall segmentation in magnetic resonance images of atherosclerotic carotid arteries

    NASA Astrophysics Data System (ADS)

    Adame, Isabel M.; van der Geest, Rob J.; Wasserman, Bruce A.; Mohamed, Mona; Reiber, Johan H. C.; Lelieveldt, Boudewijn P. F.

    2004-05-01

    Composition and structure of atherosclerotic plaque is a primary focus of cardiovascular research. In vivo MRI provides a meanse to non-invasively image and assess the morphological features of athersclerotic and normal human carotid arteries. To quantitatively assess the vulnerability and the type of plaque, the contours of the lumen, outer boundary of the vessel wall and plaque components, need to be traced. To achieve this goal, we have developed an automated contou detection technique, which consists of three consecutive steps: firstly, the outer boundary of the vessel wall is detected by means of an ellipse-fitting procedure in order to obtain smoothed shapes; secondly, the lumen is segnented using fuzzy clustering. Thre region to be classified is that within the outer vessel wall boundary obtained from the previous step; finally, for plaque detection we follow the same approach as for lumen segmentation: fuzzy clustering. However, plaque is more difficult to segment, as the pixel gray value can differ considerably from one region to another, even when it corresponds to the same type of tissue. That makes further processing necessary. All these three steps might be carried out combining information from different sequences (PD-, T2-, T1-weighted images, pre- and post-contrast), to improve the contour detection. The algorithm has been validated in vivo on 58 high-resolution PD and T1 weighted MR images (19 patients). The results demonstrate excellent correspondence between automatic and manual area measurements: lumen (r=0.94), outer (r=0.92), and acceptable for fibrous cap thickness (r=0.76).

  4. [Tolerance of +Gz accelerations in chronic compensated cardiac muscle disease].

    PubMed

    Suvorov, P M; Bykova, Iu I

    1975-01-01

    The functional potentialities of the cardiovascular system were investigated during an exposure of people with compensated chronic diseases of the cardiac muscle to acceleration (+Gz). The test subjects were exposed to acceleration of 3 and 5 g for 30 sec with an interval of 5 min. The parameters of hemodynamics, ECG and visual perception were recorded. The systolic blood volume, cardiac output and specific peripheral resistance were derived from the Bremser-Ranke formula. Seventy one subjects with heart diseases and 23 healthy subjects were examined. The subjects with myocardiodystrophy and myocarditic cardiosclerosis (12+/-16) showed a reduced tolerance to accelerations. During an exposure the subjects with atherosclerotic cardiosclerosis showed a higher pressure in vessels of ear conch than the healthy subjects. The myocardiodystrophic subjects frequently (20%) exhibited an inversion of electrocardiographic T2. The subjects with heart diseases (27-33%) showed extrasystolic disturbances. The results may be used in medical expertise of pilots.

  5. [Tolerance of +Gz accelerations in chronic compensated cardiac muscle disease].

    PubMed

    Suvorov, P M; Bykova, Iu I

    1975-01-01

    The functional potentialities of the cardiovascular system were investigated during an exposure of people with compensated chronic diseases of the cardiac muscle to acceleration (+Gz). The test subjects were exposed to acceleration of 3 and 5 g for 30 sec with an interval of 5 min. The parameters of hemodynamics, ECG and visual perception were recorded. The systolic blood volume, cardiac output and specific peripheral resistance were derived from the Bremser-Ranke formula. Seventy one subjects with heart diseases and 23 healthy subjects were examined. The subjects with myocardiodystrophy and myocarditic cardiosclerosis (12+/-16) showed a reduced tolerance to accelerations. During an exposure the subjects with atherosclerotic cardiosclerosis showed a higher pressure in vessels of ear conch than the healthy subjects. The myocardiodystrophic subjects frequently (20%) exhibited an inversion of electrocardiographic T2. The subjects with heart diseases (27-33%) showed extrasystolic disturbances. The results may be used in medical expertise of pilots. PMID:1214489

  6. Cast dielectric composite linear accelerator

    DOEpatents

    Sanders, David M.; Sampayan, Stephen; Slenes, Kirk; Stoller, H. M.

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  7. k-t Acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs

    NASA Astrophysics Data System (ADS)

    Xiao, Dan; Balcom, Bruce J.

    2014-06-01

    Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems.

  8. k-t acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs.

    PubMed

    Xiao, Dan; Balcom, Bruce J

    2014-06-01

    Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems.

  9. k-t acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs.

    PubMed

    Xiao, Dan; Balcom, Bruce J

    2014-06-01

    Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems. PMID:24809307

  10. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance.

    PubMed

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-01-01

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys. PMID:27535800

  11. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-08-01

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys.

  12. A Doping Lattice of Aluminum and Copper with Accelerated Electron Transfer Process and Enhanced Reductive Degradation Performance

    PubMed Central

    Zhang, Lin; Gao, Xue; Zhang, Zhixuan; Zhang, Mingbo; Cheng, Yiqian; Su, Jixin

    2016-01-01

    Treatment of azo dye effluents has received increasing concerns over the years due to their potential harms to natural environment and human health. The present study described the degrading ability of the as-synthesized crystalline Al-Cu alloys for removal of high-concentration Acid Scarlet 3R in alkaline aqueous solutions and its degradation mechanism. Al-Cu alloy particles with Al/Cu ratios 19:1 were successfully synthesized by high-energy mechanical milling. Characterization results showed that 10 h mechanical alloying process could lead to the formation of crystalline Al(Cu) solid solution. Batch experiment results confirmed the excellent ability of Al-Cu alloy particles for the degradation of 3R in aqueous solution. Under a certain condition ([Al-Cu]0 = 2 g/L, [3R]0 = 200 mg/L, [NaCl]0 = 25 g/L, initial pH = 10.9), the 3R could be completely degraded within only 3 min. It was also found that the degradation reaction followed zero-order kinetics model with respect to the initial dye concentration. The intermediate compounds were identified by UV-vis, FT-IR and HPLC-MS, and a pathway was proposed. Additionally, post-treatment Al-Cu alloy particles were characterized by SEM and TEM, and the results showed that the degradation might be attributed to the corrosion effect of Al-Cu alloys. PMID:27535800

  13. Structural, dynamic, and electrostatic properties of fully hydrated DMPC bilayers from molecular dynamics simulations accelerated with graphical processing units (GPUs).

    PubMed

    Ganesan, Narayan; Bauer, Brad A; Lucas, Timothy R; Patel, Sandeep; Taufer, Michela

    2011-11-15

    We present results of molecular dynamics simulations of fully hydrated DMPC bilayers performed on graphics processing units (GPUs) using current state-of-the-art non-polarizable force fields and a local GPU-enabled molecular dynamics code named FEN ZI. We treat the conditionally convergent electrostatic interaction energy exactly using the particle mesh Ewald method (PME) for solution of Poisson's Equation for the electrostatic potential under periodic boundary conditions. We discuss elements of our implementation of the PME algorithm on GPUs as well as pertinent performance issues. We proceed to show results of simulations of extended lipid bilayer systems using our program, FEN ZI. We performed simulations of DMPC bilayer systems consisting of 17,004, 68,484, and 273,936 atoms in explicit solvent. We present bilayer structural properties (atomic number densities, electron density profiles), deuterium order parameters (S(CD)), electrostatic properties (dipole potential, water dipole moments), and orientational properties of water. Predicted properties demonstrate excellent agreement with experiment and previous all-atom molecular dynamics simulations. We observe no statistically significant differences in calculated structural or electrostatic properties for different system sizes, suggesting the small bilayer simulations (less than 100 lipid molecules) provide equivalent representation of structural and electrostatic properties associated with significantly larger systems (over 1000 lipid molecules). We stress that the three system size representations will have differences in other properties such as surface capillary wave dynamics or surface tension related effects that are not probed in the current study. The latter properties are inherently dependent on system size. This contribution suggests the suitability of applying emerging GPU technologies to studies of an important class of biological environments, that of lipid bilayers and their associated integral

  14. Compact accelerator

    DOEpatents

    Caporaso, George J.; Sampayan, Stephen E.; Kirbie, Hugh C.

    2007-02-06

    A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

  15. The neutrino electron accelerator

    SciTech Connect

    Shukla, P.K.; Stenflo, L.; Bingham, R.; Bethe, H.A.; Dawson, J.M.; Mendonca, J.T.

    1998-01-01

    It is shown that a wake of electron plasma oscillations can be created by the nonlinear ponderomotive force of an intense neutrino flux. The electrons trapped in the plasma wakefield will be accelerated to high energies. Such processes may be important in supernovas and pulsars. {copyright} {ital 1998 American Institute of Physics.}

  16. FPGA Verification Accelerator (FVAX)

    NASA Technical Reports Server (NTRS)

    Oh, Jane; Burke, Gary

    2008-01-01

    Is Verification Acceleration Possible? - Increasing the visibility of the internal nodes of the FPGA results in much faster debug time - Forcing internal signals directly allows a problem condition to be setup very quickly center dot Is this all? - No, this is part of a comprehensive effort to improve the JPL FPGA design and V&V process.

  17. BICEP's acceleration

    SciTech Connect

    Contaldi, Carlo R.

    2014-10-01

    The recent Bicep2 [1] detection of, what is claimed to be primordial B-modes, opens up the possibility of constraining not only the energy scale of inflation but also the detailed acceleration history that occurred during inflation. In turn this can be used to determine the shape of the inflaton potential V(φ) for the first time — if a single, scalar inflaton is assumed to be driving the acceleration. We carry out a Monte Carlo exploration of inflationary trajectories given the current data. Using this method we obtain a posterior distribution of possible acceleration profiles ε(N) as a function of e-fold N and derived posterior distributions of the primordial power spectrum P(k) and potential V(φ). We find that the Bicep2 result, in combination with Planck measurements of total intensity Cosmic Microwave Background (CMB) anisotropies, induces a significant feature in the scalar primordial spectrum at scales k∼ 10{sup -3} Mpc {sup -1}. This is in agreement with a previous detection of a suppression in the scalar power [2].

  18. Immunolocalization of BMP-6, a novel TGF-beta-related cytokine, in normal and atherosclerotic smooth muscle cells.

    PubMed

    Schluesener, H J; Meyermann, R

    1995-03-01

    We have analyzed expression of a novel transforming growth factor type beta (TGF-beta)-related cytokine, bone morphogenetic protein-6 (BMP-6) in normal and atherosclerotic brain arteries. BMP-6 immunoreactivity was detected in smooth muscle cells of normal cerebral blood vessels. It is also expressed by smooth muscle cells of intimal plaques in atherosclerotically changed blood vessels. The BMPs regulate tissue modeling and remodeling and aberrant expression of BMPs might contribute to smooth muscle cell migration, proliferation, tissue reorganization and macrophage attraction, which are known mechanisms of atherosclerotic plaque formation. PMID:7605353

  19. Phenolic composition of vinegars over an accelerated aging process using different wood species (acacia, cherry, chestnut, and oak): effect of wood toasting.

    PubMed

    Cerezo, Ana B; Álvarez-Fernández, M Antonia; Hornedo-Ortega, Ruth; Troncoso, Ana M; García-Parrilla, M Carmen

    2014-05-14

    Wood shavings are widely employed in vinegar making to reduce aging time. Accordingly, this study aims to evaluate the effects of using shavings from different wood species (acacia, cherry, chestnut, and oak) and of toasting on the release of phenolic compounds into vinegar during the aging process. The study involved aging vinegars using previously toasted shavings and untoasted ones, at 0.5% and 1% (w/v), and collecting samples at 15 and 30 days. The phenolic compounds were analyzed by LC-DAD during the aging process. As a result, wood markers naringenin and kaempferol (cherry), robinetin and fustin (acacia), and isovanillin (oak) were identified for the first time in vinegars. The results also showed that toasting wood shavings decreases the concentration of most flavonoid wood markers (e.g., (+)-taxifolin, naringenin, and fustin) in vinegar, but that it is essential for the highest releases of aldehyde compounds (syringaldehyde, protocatechualdehyde, and vanillin). Remarkably, 15 days was sufficient to obtain the highest increases of most polyphenol compounds in the vinegar. Statistical analysis (linear discriminant analysis) proved that the phenolic compounds identified in vinegars are useful for discriminating vinegars regarding the wood species of the shavings used to accelerate aging.

  20. Interfacing to accelerator instrumentation

    SciTech Connect

    Shea, T.J.

    1995-12-31

    As the sensory system for an accelerator, the beam instrumentation provides a tremendous amount of diagnostic information. Access to this information can vary from periodic spot checks by operators to high bandwidth data acquisition during studies. In this paper, example applications will illustrate the requirements on interfaces between the control system and the instrumentation hardware. A survey of the major accelerator facilities will identify the most popular interface standards. The impact of developments such as isochronous protocols and embedded digital signal processing will also be discussed.

  1. Accelerated molecular dynamics methods

    SciTech Connect

    Perez, Danny

    2011-01-04

    The molecular dynamics method, although extremely powerful for materials simulations, is limited to times scales of roughly one microsecond or less. On longer time scales, dynamical evolution typically consists of infrequent events, which are usually activated processes. This course is focused on understanding infrequent-event dynamics, on methods for characterizing infrequent-event mechanisms and rate constants, and on methods for simulating long time scales in infrequent-event systems, emphasizing the recently developed accelerated molecular dynamics methods (hyperdynamics, parallel replica dynamics, and temperature accelerated dynamics). Some familiarity with basic statistical mechanics and molecular dynamics methods will be assumed.

  2. Accelerators for research and applications

    SciTech Connect

    Alonso, J.R.

    1990-06-01

    The newest particle accelerators are almost always built for extending the frontiers of research, at the cutting edge of science and technology. Once these machines are operating and these technologies mature, new applications are always found, many of which touch our lives in profound ways. The evolution of accelerator technologies will be discussed, with descriptions of accelerator types and characteristics. The wide range of applications of accelerators will be discussed, in fields such as nuclear science, medicine, astrophysics and space-sciences, power generation, airport security, materials processing and microcircuit fabrication. 13 figs.

  3. Effects of Cinacalcet on Atherosclerotic and Nonatherosclerotic Cardiovascular Events in Patients Receiving Hemodialysis: The EValuation Of Cinacalcet HCl Therapy to Lower CardioVascular Events (EVOLVE) Trial

    PubMed Central

    Wheeler, David C.; London, Gerard M.; Parfrey, Patrick S.; Block, Geoffrey A.; Correa‐Rotter, Ricardo; Dehmel, Bastian; Drüeke, Tilman B.; Floege, Jürgen; Kubo, Yumi; Mahaffey, Kenneth W.; Goodman, William G.; Moe, Sharon M.; Trotman, Marie‐Louise; Abdalla, Safa; Chertow, Glenn M.; Herzog, Charles A.

    2014-01-01

    Background Premature cardiovascular disease limits the duration and quality of life on long‐term hemodialysis. The objective of this study was to define the frequency of fatal and nonfatal cardiovascular events attributable to atherosclerotic and nonatherosclerotic mechanisms, risk factors for these events, and the effects of cinacalcet, using adjudicated data collected during the EValuation of Cinacalcet HCl Therapy to Lower CardioVascular Events (EVOLVE) Trial. Methods and Results EVOLVE was a randomized, double‐blind, placebo‐controlled clinical trial that randomized 3883 hemodialysis patients with moderate to severe secondary hyperparathyroidism to cinacalcet or matched placebo for up to 64 months. For this post hoc analysis, the outcome measure was fatal and nonfatal cardiovascular events reflecting atherosclerotic and nonatherosclerotic cardiovascular diseases. During the trial, 1518 patients experienced an adjudicated cardiovascular event, including 958 attributable to nonatherosclerotic disease. Of 1421 deaths during the trial, 768 (54%) were due to cardiovascular disease. Sudden death was the most frequent fatal cardiovascular event, accounting for 24.5% of overall mortality. Combining fatal and nonfatal cardiovascular events, randomization to cinacalcet reduced the rates of sudden death and heart failure. Patients randomized to cinacalcet experienced fewer nonatherosclerotic cardiovascular events (adjusted relative hazard 0.84, 95% CI 0.74 to 0.96), while the effect of cinacalcet on atherosclerotic events did not reach statistical significance. Conclusions Accepting the limitations of post hoc analysis, any benefits of cinacalcet on cardiovascular disease in the context of hemodialysis may result from attenuation of nonatherosclerotic processes. Clinical Trials Registration Unique identifier: NCT00345839. URL: ClinicalTrials.gov. PMID:25404192

  4. Aggregatibacter actinomycetemcomitans induces Th17 cells in atherosclerotic lesions.

    PubMed

    Jia, Ru; Hashizume-Takizawa, Tomomi; Du, Yuan; Yamamoto, Masafumi; Kurita-Ochiai, Tomoko

    2015-04-01

    Th17 cells have been linked to the pathogenesis of several chronic inflammatory and autoimmune diseases. However, the role of Th17 cells and IL-17 in atherosclerosis remains poorly understood. We previously reported that Aggregatibacter actinomycetemcomitans (Aa) bacteremia accelerated atherosclerosis accompanied by inflammation in apolipoprotein E-deficient spontaneously hyperlipidemic (Apoe(shl)) mice. In this study, we investigated whether Aa promotes the Th17 inducing pathway in Aa-challenged Apoe(shl) mice. Mice were intravenously injected with live Aa HK1651 or vehicles. Time-course analysis of splenic IL-17(+)CD4(+) cell frequencies, the proximal aorta lesion area, serum IL-17, IL-6, TGF-β and IL-1β levels, the mRNA expression of Th17-related molecules such as IL-1β, IL-6, IL17RA, STAT3, IL-21, IL-23, TGF-β and RORγt, Th17-related microRNA levels and the levels of AIM-2, Mincle and NLRP3 were examined. Challenge with Aa time dependently induced tropism of Th17 cells in the spleen and increase in atheromatous lesions in the aortic sinus of Apoe(shl) mice. Serum IL-17, IL-6, TGF-β and IL-1β levels were significantly enhanced by Aa. The gene expression of IL-1β, IL-6, IL-17RA, IL-21, IL-23, TGF-β, STAT3, RORγt, AIM-2, Mincle and NLRP3 was also time dependently stimulated in the aorta of Aa-challenged mice. Furthermore, Aa challenge significantly increased the expression of miR-146b and miR-155 in the aorta. Based on the results, it seems that Aa stimulates Th17 induction that affects the progression of Aa-accelerated atherosclerosis. PMID:25743474

  5. Beamlets from stochastic acceleration.

    PubMed

    Perri, Silvia; Carbone, Vincenzo

    2008-09-01

    We investigate the dynamics of a realization of the stochastic Fermi acceleration mechanism. The model consists of test particles moving between two oscillating magnetic clouds and differs from the usual Fermi-Ulam model in two ways. (i) Particles can penetrate inside clouds before being reflected. (ii) Particles can radiate a fraction of their energy during the process. Since the Fermi mechanism is at work, particles are stochastically accelerated, even in the presence of the radiated energy. Furthermore, due to a kind of resonance between particles and oscillating clouds, the probability density function of particles is strongly modified, thus generating beams of accelerated particles rather than a translation of the whole distribution function to higher energy. This simple mechanism could account for the presence of beamlets in some space plasma physics situations.

  6. Advanced concepts for acceleration

    SciTech Connect

    Keefe, D.

    1986-07-01

    Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations. (LEW)

  7. Laser acceleration and its future

    PubMed Central

    Tajima, Toshiki

    2010-01-01

    Laser acceleration is based on the concept to marshal collective fields that may be induced by laser. In order to exceed the material breakdown field by a large factor, we employ the broken-down matter of plasma. While the generated wakefields resemble with the fields in conventional accelerators in their structure (at least qualitatively), it is their extreme accelerating fields that distinguish the laser wakefield from others, amounting to tiny emittance and compact accelerator. The current research largely falls on how to master the control of acceleration process in spatial and temporal scales several orders of magnitude smaller than the conventional method. The efforts over the last several years have come to a fruition of generating good beam properties with GeV energies on a table top, leading to many applications, such as ultrafast radiolysis, intraoperative radiation therapy, injection to X-ray free electron laser, and a candidate for future high energy accelerators. PMID:20228616

  8. Advanced accelerator theory development

    SciTech Connect

    Sampayan, S.E.; Houck, T.L.; Poole, B.; Tishchenko, N.; Vitello, P.A.; Wang, I.

    1998-02-09

    A new accelerator technology, the dielectric wall accelerator (DWA), is potentially an ultra compact accelerator/pulsed power driver. This new accelerator relies on three new components: the ultra-high gradient insulator, the asymmetric Blumlein and low jitter switches. In this report, we focused our attention on the first two components of the DWA system the insulators and the asymmetric Blumlein. First, we sought to develop the necessary design tools to model and scale the behavior of the high gradient insulator. To perform this task we concentrated on modeling the discharge processes (i.e., initiation and creation of the surface discharge). In addition, because these high gradient structures exhibit favorable microwave properties in certain accelerator configurations, we performed experiments and calculations to determine the relevant electromagnetic properties. Second, we performed circuit modeling to understand energy coupling to dynamic loads by the asymmetric Blumlein. Further, we have experimentally observed a non-linear coupling effect in certain asymmetric Blumlein configurations. That is, as these structures are stacked into a complete module, the output voltage does not sum linearly and a lower than expected output voltage results. Although we solved this effect experimentally, we performed calculations to understand this effect more fully to allow better optimization of this DWA pulse-forming line system.

  9. Accelerated oxidation processes is biodiesel

    SciTech Connect

    Canakci, M.; Monyem, A.; Van Gerpen, J.

    1999-12-01

    Biodiesel is an alternative fuel for diesel engines that can be produced from renewable feedstocks such as vegetable oil and animal fats. These feedstocks are reacted with an alcohol to produce alkyl monoesters that can be used in conventional diesel engines with little or no modification. Biodiesel, especially if produced from highly unsaturated oils, oxidizes more rapidly than diesel fuel. This article reports the results of experiments to track the chemical and physical changes that occur in biodiesel as it oxidizes. These results show the impact of time, oxygen flow rate, temperature, metals, and feedstock type on the rate of oxidation. Blending with diesel fuel and the addition of antioxidants are explored also. The data indicate that without antioxidants, biodiesel will oxidize very quickly at temperatures typical of diesel engines. This oxidation results in increases in peroxide value, acid value, and viscosity. While the peroxide value generally reaches a plateau of about 350 meq/kg ester, the acid value and viscosity increase monotonically as oxidation proceeds.

  10. David M. Hume memorial lecture. In situ vein bypass in the treatment of femoropopliteal atherosclerotic disease: a ten year study.

    PubMed

    Hall, K V; Rostad, H

    1978-08-01

    The in situ vein bypass technic for femoropopliteal atherosclerotic disease is described. Several factors influence the long-term results, the most important being a history of myocardial disease, the size of the vein graft, and sufficient runoff.

  11. Accelerating electrostatic interaction calculations with graphical processing units based on new developments of Ewald method using non-uniform fast Fourier transform.

    PubMed

    Yang, Sheng-Chun; Wang, Yong-Lei; Jiao, Gui-Sheng; Qian, Hu-Jun; Lu, Zhong-Yuan

    2016-01-30

    We present new algorithms to improve the performance of ENUF method (F. Hedman, A. Laaksonen, Chem. Phys. Lett. 425, 2006, 142) which is essentially Ewald summation using Non-Uniform FFT (NFFT) technique. A NearDistance algorithm is developed to extensively reduce the neighbor list size in real-space computation. In reciprocal-space computation, a new algorithm is developed for NFFT for the evaluations of electrostatic interaction energies and forces. Both real-space and reciprocal-space computations are further accelerated by using graphical processing units (GPU) with CUDA technology. Especially, the use of CUNFFT (NFFT based on CUDA) very much reduces the reciprocal-space computation. In order to reach the best performance of this method, we propose a procedure for the selection of optimal parameters with controlled accuracies. With the choice of suitable parameters, we show that our method is a good alternative to the standard Ewald method with the same computational precision but a dramatically higher computational efficiency. PMID:26584145

  12. Pulsed electromagnetic gas acceleration

    NASA Technical Reports Server (NTRS)

    Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

    1974-01-01

    Detailed measurements of the axial velocity profile and electromagnetic structure of a high power, quasi-steady MPD discharge are used to formulate a gasdynamic model of the acceleration process. Conceptually dividing the accelerated plasma into an inner flow and an outer flow, it is found that more than two-thirds of the total power in the plasma is deposited in the inner flow, accelerating it to an exhaust velocity of 12.5 km/sec. The outer flow, which is accelerated to a velocity of only 6.2 km/sec, appears to provide a current conduction path between the inner flow and the anode. Related cathode studies have shown that the critical current for the onset of terminal voltage fluctuations, which was recently shown to be a function of the cathode area, appears to reach an asymptote for cathodes of very large surface area. Detailed floating potential measurements show that the fluctuations are confined to the vicinity of the cathode and hence reflect a cathode emission process rather than a fundamental limit on MPD performance.

  13. Increased Platelet Reactivity Is Associated with Circulating Platelet-Monocyte Complexes and Macrophages in Human Atherosclerotic Plaques

    PubMed Central

    Vrijenhoek, Joyce E. P.; van Holten, Thijs C.; Elsenberg, Ellen H. A. M.; Mak-Nienhuis, Elske M.; de Borst, Gert Jan; Jukema, J. Wouter; Pijls, Nico H. J.; Waltenberger, Johannes; van Zonneveld, Anton Jan; Moll, Frans L.; McClellan, Elizabeth; Stubbs, Andrew; Pasterkamp, Gerard; Hoefer, Imo; de Groot, Philip G.; Roest, Mark

    2014-01-01

    Objective Platelet reactivity, platelet binding to monocytes and monocyte infiltration play a detrimental role in atherosclerotic plaque progression. We investigated whether platelet reactivity was associated with levels of circulating platelet-monocyte complexes (PMCs) and macrophages in human atherosclerotic carotid plaques. Methods Platelet reactivity was determined by measuring platelet P-selectin expression after platelet stimulation with increasing concentrations of adenosine diphosphate (ADP), in two independent cohorts: the Circulating Cells cohort (n = 244) and the Athero-Express cohort (n = 91). Levels of PMCs were assessed by flow cytometry in blood samples of patients who were scheduled for percutaneous coronary intervention (Circulating Cells cohort). Monocyte infiltration was semi-quantitatively determined by histological examination of atherosclerotic carotid plaques collected during carotid endarterectomy (Athero-Express cohort). Results We found increased platelet reactivity in patients with high PMCs as compared to patients with low PMCs (median (interquartile range): 4153 (1585–11267) area under the curve (AUC) vs. 9633 (3580–21565) AUC, P<0.001). Also, we observed increased platelet reactivity in patients with high macrophage levels in atherosclerotic plaques as compared to patients with low macrophage levels in atherosclerotic plaques (mean±SD; 8969±3485 AUC vs. 7020±3442 AUC, P = 0.02). All associations remained significant after adjustment for age, sex and use of drugs against platelet activation. Conclusion Platelet reactivity towards ADP is associated with levels of PMCs and macrophages in human atherosclerotic carotid plaques. PMID:25122139

  14. Red and black rice decrease atherosclerotic plaque formation and increase antioxidant status in rabbits.

    PubMed

    Ling, W H; Cheng, Q X; Ma, J; Wang, T

    2001-05-01

    The influence of white, red and black rice consumption on atherosclerotic plaque formation induced by hypercholesterolemia was investigated in rabbits. Male rabbits (n = 36) were divided into five groups. They were fed a normal laboratory purified diet (normal group, n = 6), a high cholesterol (0.5 g/100 g) diet (HC group, n = 6), a high cholesterol diet with 30 g/100 g white rice (WR group, n = 8), 30 g/100 g red rice (RR group, n = 8), or 30 g/100 g black rice (BR group, n = 8) for 10 wk. Blood samples were collected for lipid measurements and aorta were removed for assessment of atherosclerotic plaques at the end of the protocol. The oxidant and antioxidant status of blood, erythrocytes, liver and aorta was evaluated. The area of atherosclerotic plaque was 50% lower in rabbits fed the red or black rice diets than in those fed the white rice diet. Compared with the HC and WR groups, serum HDL cholesterol and apolipoprotein (apo) A-I concentration were greater (P < 0.05) in the RR and BR groups. Liver reactive oxygen species (ROS) and aortic malondialdehyde (MDA) were significantly lower, and the liver total antioxidative capacity (TAC) and erythrocyte superoxide dismutase (SOD) activity were significantly higher in the RR and BR groups compared with the HC and WR groups. Red or black rice consumption reduced or retarded the progression of atherosclerotic plaque development induced by dietary cholesterol. The enhanced serum HDL cholesterol and apo A-I concentrations, and the increased antioxidant and decreased oxidative status may be mechanisms of the antiatherogenic effect of red or black rice. PMID:11340093

  15. Development of Advanced Atherosclerotic Plaque by Injection of Inflammatory Proteins in a Rabbit Iliac Artery Model

    PubMed Central

    Kim, Jung-Sun; Lee, Seul-Gee; Oh, Jaewon; Park, Se-Il; Hong, Sung-Yu; Kim, Sehoon; Lee, Sang-Hak; Ko, Young-Guk; Choi, Donghoon; Hong, Myeong-Ki; Jang, Yangsoo

    2016-01-01

    Purpose Appropriate animal models of atherosclerotic plaque are crucial to investigating the pathophysiology of atherosclerosis, as well as for the evaluation of the efficacy and safety of vascular devices. We aimed to develop a novel animal model that would be suitable for the study of advanced atherosclerotic lesions in vivo. Materials and Methods Atherosclerotic plaque was induced in 24 iliac arteries from 12 rabbits by combining a high cholesterol diet, endothelial denudation, and injection into the vessel wall with either saline (n=5), olive oil (n=6), or inflammatory proteins [n=13, high-mobility group protein B1 (HMGB1) n=8 and tumor necrosis factor (TNF)-α n=5] using a Cricket™ Micro-infusion catheter. Optical coherence tomography (OCT) was performed to detect plaque characteristics after 4 weeks, and all tissues were harvested for histological evaluation. Results Advanced plaque was more frequently observed in the group injected with inflammatory proteins. Macrophage infiltration was present to a higher degree in the HMGB1 and TNF-α groups, compared to the oil or saline group (82.1±5.1% and 94.6±2.2% compared to 49.6±14.0% and 46.5±9.6%, p-value<0.001), using RAM11 antibody staining. On OCT, lipid rich plaques were more frequently detected in the inflammatory protein group [saline group: 2/5 (40%), oil group: 3/5 (50%), HMGB1 group: 6/8 (75%), and TNF-α group: 5/5 (100%)]. Conclusion These data indicate that this rabbit model of atherosclerotic lesion formation via direct injection of pro-inflammatory proteins into the vessel wall is useful for in vivo studies investigating atherosclerosis. PMID:27401639

  16. IL-35 improves Treg-mediated immune suppression in atherosclerotic mice

    PubMed Central

    Tao, Linlin; Zhu, Jie; Chen, Yuefeng; Wang, Qinghang; Pan, Ying; Yu, Qianqian; Zhou, Birong; Zhu, Huaqing

    2016-01-01

    Interleukin (IL)-35 is an anti-inflammatory cytokine that may have a protective role in atherosclerosis (AS). However, the exact role of IL-35 in the disease, and the etiology of AS, remain incompletely understood. The present study aimed to investigate whether exogenous IL-35 was able to attenuate the formation of atherosclerotic lesions in apoE−/− mice, and analyze alterations in the expression levels of forkhead box protein 3 (Foxp3) in peripheral blood and the lesions during the progression of AS. ApoE−/− mice were randomly divided into two groups that received either a basal diet (negative control group) or a high-fat diet (HFD) for 4 weeks. The HFD group was further subdivided into groups that received IL-35, atorvastatin or no treatment for 12 weeks. Diagnostic enzyme assay kits were applied for the detection of plasma lipids, and hematoxylin and eosin staining was used to analyze the severity of atherosclerotic lesions in apoE−/− mice. Immunohistochemistry and flow cytometry were performed to analyze the expression of Foxp3 in the plasma and atherosclerotic plaques. As compared with the negative control group, the plasma lipids were significantly increased, and the lesions were obviously formed, in the HFD groups. Furthermore, the area of the lesion was reduced in IL-35- and atorvastatin-treated groups, as compared with the AS control group. In addition, Foxp3 expression was upregulated in the plasma and lesions of the IL-35- and atorvastatin-treated groups, as compared with the AS control group. The present study demonstrated that IL-35 improved Treg-mediated immune suppression in atherosclerotic mice, thus suggesting that IL-35 may be a novel therapeutic target for AS.

  17. IL-35 improves Treg-mediated immune suppression in atherosclerotic mice

    PubMed Central

    Tao, Linlin; Zhu, Jie; Chen, Yuefeng; Wang, Qinghang; Pan, Ying; Yu, Qianqian; Zhou, Birong; Zhu, Huaqing

    2016-01-01

    Interleukin (IL)-35 is an anti-inflammatory cytokine that may have a protective role in atherosclerosis (AS). However, the exact role of IL-35 in the disease, and the etiology of AS, remain incompletely understood. The present study aimed to investigate whether exogenous IL-35 was able to attenuate the formation of atherosclerotic lesions in apoE−/− mice, and analyze alterations in the expression levels of forkhead box protein 3 (Foxp3) in peripheral blood and the lesions during the progression of AS. ApoE−/− mice were randomly divided into two groups that received either a basal diet (negative control group) or a high-fat diet (HFD) for 4 weeks. The HFD group was further subdivided into groups that received IL-35, atorvastatin or no treatment for 12 weeks. Diagnostic enzyme assay kits were applied for the detection of plasma lipids, and hematoxylin and eosin staining was used to analyze the severity of atherosclerotic lesions in apoE−/− mice. Immunohistochemistry and flow cytometry were performed to analyze the expression of Foxp3 in the plasma and atherosclerotic plaques. As compared with the negative control group, the plasma lipids were significantly increased, and the lesions were obviously formed, in the HFD groups. Furthermore, the area of the lesion was reduced in IL-35- and atorvastatin-treated groups, as compared with the AS control group. In addition, Foxp3 expression was upregulated in the plasma and lesions of the IL-35- and atorvastatin-treated groups, as compared with the AS control group. The present study demonstrated that IL-35 improved Treg-mediated immune suppression in atherosclerotic mice, thus suggesting that IL-35 may be a novel therapeutic target for AS. PMID:27698748

  18. Oral rapamycin inhibits growth of atherosclerotic plaque in apoE knock-out mice

    SciTech Connect

    Waksman, Ron; Pakala, Rajbabu; Burnett, Mary S.; Gulick, Cindy P.; Leborgne, Laurent; Fournadjiev, Jana; Wolfram, Roswitha; Hellinga, David

    2003-03-01

    Introduction: Inflammatory and immunological responses of vascular cells are known to play significant roles in atherosclerotic plaque development. Rapamycin with antiinflammatory, immunosuppressive and antiproliferative properties has been shown to reduce neointima formation when coated on stents. This study is designed to test the potential of oral rapamycin to inhibit atherosclerotic plaque development. Methods: Eight-week-old apoE knock-out mice were fed with 0.25% cholesterol supplemented diet (control diet), control diet containing 50 {mu}g/kg rapamycin (low-dose rapamycin) or 100 {mu}g/kg rapamycin (high-dose rapamycin) for 4 or 8 weeks. Subsets of mice from each group (n=10) were weighed and euthanized. Whole blood rapamycin levels were determined using HPLC-MS/MS, and histological analyses of atherosclerotic lesions in the aortic root were performed. Results: Mice fed with high-dose rapamycin did not gain weight (18.5{+-}1.5 vs. 20.6{+-}0.9 g, P=.01). Blood levels of rapamycin 117{+-}7 pg/ml were detected in the blood of mice fed with high-dose rapamycin for 8 weeks. The plaque area in mice fed with high dose oral rapamycin is significantly less as compared to control (0.168{+-}0.008 vs. 0.326{+-}0.013 mm{sup 2}, P=.001 at 4 weeks; 0.234{+-}0.013 vs. 0.447{+-}0.011 mm{sup 2}, P=.001 at 8 weeks). Lumen area was inversely proportional to the plaque area. Conclusions: The results indicate that oral rapamycin is effective in attenuating the progression of atherosclerotic plaque in the mice.

  19. Pharmacokinetics and atherosclerotic lesions targeting effects of tanshinone IIA discoidal and spherical biomimetic high density lipoproteins.

    PubMed

    Zhang, Wenli; He, Hongliang; Liu, Jianping; Wang, Ji; Zhang, Suyang; Zhang, Shuangshuang; Wu, Zimei

    2013-01-01

    High density lipoproteins (HDL) have been successfully reconstructed to deliver a large number of lipophilic drugs. Here, discoidal and spherical recombinant HDL loaded with cardiovascular drug tanshinone IIA (TA) were constructed (TA-d-rHDL and TA-s-rHDL), respectively. And next their in vitro physiochemical and biomimetic properties were characterized. Furthermore, pharmacokinetics, atherosclerotic lesions targeting effects and antiatherogenic efficacies were elaborately performed and compared in atherosclerotic New Zealand White (NZW) rabbits. In vitro characterizations results showed that both TA-d-rHDL and TA-s-rHDL had nano-size diameter, high entrapment efficiency (EE) and drug-loading capacity (DL). Additionally, similar to their native counterparts, TA-d-rHDL maintained remodeling behaviors induced by lecithin cholesterol acyltransferase (LCAT), and TA leaked during remodeling behaviors. Pharmacokinetic studies manifested that both TA-d-rHDL and TA-s-rHDL markedly improved pharmacokinetic behaviors of TA in vivo. Ex vivo imaging demonstrated that both d-rHDL and s-rHDL bound more avidly to atherosclerotic lesions than to normal vessel walls, and s-rHDL had better targeting effect than d-rHDL. Pharmacodynamic tests illustrated that both TA-d-rHDL and TA-s-rHDL had much stronger antiatherogenic efficacies than conventional TA nanostructured lipid carriers (TA-NLC), TA liposomes (TA-L) and commercially available preparation Sulfotanshinone Sodium Injection (SSI). Moreover, TA-s-rHDL had more potent antiatherogenic efficacies than TA-d-rHDL. Collectively our studies indicated that rHDL could be exploited as potential delivery vehicles of TA targeting atherosclerotic lesions as well as synergistically improving efficacies, especially for s-rHDL. PMID:23069716

  20. Selepressin and Arginine Vasopressin Do Not Display Cardiovascular Risk in Atherosclerotic Rabbit

    PubMed Central

    Boucheix, Olivier; Blakytny, Robert; Haroutunian, Gerard; Henriksson, Marie; Laporte, Regent; Milano, Stephane; Reinheimer, Torsten M.

    2016-01-01

    Background Septic shock remains associated with significant mortality rates. Arginine vasopressin (AVP) and analogs with V1A receptor agonist activity are increasingly used to treat fluid-resistant vasodilatory hypotension, including catecholamine-refractory septic shock. Clinical studies have been restricted to healthy volunteers and catecholamine-refractory septic shock patients excluding subjects with cardiac co-morbidities because of presumed safety issues. The novel selective V1A receptor agonist selepressin, with short half-life, has been designed to avoid V2 receptor-related complications and long-term V1A receptor activation. Cardiovascular safety of selepressin, AVP, and the septic shock standard of care norepinephrine was investigated in a rabbit model of early-stage atherosclerosis. Methods Atherosclerosis was established in New Zealand White rabbits using a 1% cholesterol-containing diet. Selepressin, AVP, or norepinephrine was administered as cumulative intravenous infusion rates to atherosclerotic and non-atherosclerotic animals. Results Selepressin and AVP induced a slight dose-dependent increase in arterial pressure (AP) associated with a moderate decrease in heart rate, no change in stroke volume, and a moderate decrease in aortic blood flow (ABF). In contrast, norepinephrine induced a marked dose-dependent increase in AP associated with a lesser decrease in the heart rate, an increase in stroke volume, and a moderate increase in ABF. For all three vasopressors, there was no difference in responses between atherosclerotic and non-atherosclerotic animals. Conclusion Further studies should be considered using more advanced atherosclerosis models, including with septic shock, before considering septic shock clinical trials of patients with comorbidities. Here, selepressin and AVP treatments did not display relevant cardiovascular risk in early-stage rabbit atherosclerosis. PMID:27788216

  1. Monolithic Composite “Pressure + Acceleration + Temperature + Infrared” Sensor Using a Versatile Single-Sided “SiN/Poly-Si/Al” Process-Module

    PubMed Central

    Ni, Zao; Yang, Chen; Xu, Dehui; Zhou, Hong; Zhou, Wei; Li, Tie; Xiong, Bin; Li, Xinxin

    2013-01-01

    We report a newly developed design/fabrication module with low-cost single-sided “low-stress-silicon-nitride (LS-SiN)/polysilicon (poly-Si)/Al” process for monolithic integration of composite sensors for sensing-network-node applications. A front-side surface-/bulk-micromachining process on a conventional Si-substrate is developed, featuring a multifunctional SiN/poly-Si/Al layer design for diverse sensing functions. The first “pressure + acceleration + temperature + infrared” (PATIR) composite sensor with the chip size of 2.5 mm × 2.5 mm is demonstrated. Systematic theoretical design and analysis methods are developed. The diverse sensing components include a piezoresistive absolute-pressure sensor (up to 700 kPa, with a sensitivity of 49 mV/MPa under 3.3 V supplied voltage), a piezoresistive accelerometer (±10 g, with a sensitivity of 66 μV/g under 3.3 V and a −3 dB bandwidth of 780 Hz), a thermoelectric infrared detector (with a responsivity of 45 V/W and detectivity of 3.6 × 107 cm·Hz1/2/W) and a thermistor (−25–120 °C). This design/fabrication module concept enables a low-cost monolithically-integrated “multifunctional-library” technique. It can be utilized as a customizable tool for versatile application-specific requirements, which is very useful for small-size, low-cost, large-scale sensing-network node developments. PMID:23325169

  2. Diffusive Shock Acceleration

    NASA Astrophysics Data System (ADS)

    Baring, Matthew

    2003-04-01

    The process of diffusive acceleration of charged particles in shocked plasmas is widely invoked in astrophysics to account for the ubiquitous presence of signatures of non-thermal relativistic electrons and ions in the universe. This statistical energization mechanism, manifested in turbulent media, was first posited by Enrico Fermi in 1949 to explain the observed cosmic ray population, which exhibits an almost power-law distribution in rigidity. The absence of a momentum scale is a key characteristic of diffusive shock acceleration, and astrophysical systems generally only impose scales at the injection (low energy) and loss (high energy) ends of the particle spectrum. The existence of structure in the cosmic ray spectrum (the "knee") at around 3000 TeV has promoted contentions that there are at least two origins for cosmic rays, a galactic one supplying those up to the knee, and perhaps an extragalactic one that can explain even the ultra-high energy cosmic rays (UHECRs) seen at 1-300 EeV. Accounting for the UHECRs with familiar astrophysical sites of acceleration has historically proven difficult due to the need to assume high magnetic fields in order to reduce the shortest diffusive acceleration timescale, the ion gyroperiod, to meaningful values. Yet active galaxies and gamma-ray bursts remain strong and interesting candidate sources for UHECRs, turning the theoretical focus to relativistic shocks. This review summarizes properties of diffusive shock acceleration that are salient to the issue of UHECR generation. These include spectral indices, anisotropies, acceleration efficencies and timescales, as functions of the shock speed and mean field orientation, and also the degree of field turbulence. Astrophysical sites for UHECR production are also critiqued.

  3. Honokiol ameliorates endothelial dysfunction through suppression of PTX3 expression, a key mediator of IKK/IκB/NF-κB, in atherosclerotic cell model

    PubMed Central

    Qiu, Ling; Xu, Rong; Wang, Siyang; Li, Shuijun; Sheng, Hongguang; Wu, Jiaxi; Qu, Yi

    2015-01-01

    Pentraxin 3 (PTX3) was identified as a marker of the inflammatory response and overexpressed in various tissues and cells related to cardiovascular disease. Honokiol, an active component isolated from the Chinese medicinal herb Magnolia officinalis, was shown to have a variety of pharmacological activities. In the present study, we aimed to investigate the effects of honokiol on palmitic acid (PA)-induced dysfunction of human umbilical vein endothelial cells (HUVECs) and to elucidate potential regulatory mechanisms in this atherosclerotic cell model. Our results showed that PA significantly accelerated the expression of PTX3 in HUVECs through the IκB kinase (IKK)/IκB/nuclear factor-κB (NF-κB) pathway, reduced cell viability, induced cell apoptosis and triggered the inflammatory response. Knockdown of PTX3 supported cell growth and prevented apoptosis by blocking PA-inducted nitric oxide (NO) overproduction. Honokiol significantly suppressed the overexpression of PTX3 in PA-inducted HUVECs by inhibiting IκB phosphorylation and the expression of two NF-κB subunits (p50 and p65) in the IKK/IκB/NF-κB signaling pathway. Furthermore, honokiol reduced endothelial cell injury and apoptosis by regulating the expression of inducible NO synthase and endothelial NO synthase, as well as the generation of NO. Honokiol showed an anti-inflammatory effect in PA-inducted HUVECs by significantly inhibiting the generation of interleukin-6 (IL-6), IL-8 and monocyte chemoattractant protein-1. In summary, honokiol repaired endothelial dysfunction by suppressing PTX3 overexpression in an atherosclerotic cell model. PTX3 may be a potential therapeutic target for atherosclerosis. PMID:26138903

  4. Honokiol ameliorates endothelial dysfunction through suppression of PTX3 expression, a key mediator of IKK/IκB/NF-κB, in atherosclerotic cell model.

    PubMed

    Qiu, Ling; Xu, Rong; Wang, Siyang; Li, Shuijun; Sheng, Hongguang; Wu, Jiaxi; Qu, Yi

    2015-01-01

    Pentraxin 3 (PTX3) was identified as a marker of the inflammatory response and overexpressed in various tissues and cells related to cardiovascular disease. Honokiol, an active component isolated from the Chinese medicinal herb Magnolia officinalis, was shown to have a variety of pharmacological activities. In the present study, we aimed to investigate the effects of honokiol on palmitic acid (PA)-induced dysfunction of human umbilical vein endothelial cells (HUVECs) and to elucidate potential regulatory mechanisms in this atherosclerotic cell model. Our results showed that PA significantly accelerated the expression of PTX3 in HUVECs through the IκB kinase (IKK)/IκB/nuclear factor-κB (NF-κB) pathway, reduced cell viability, induced cell apoptosis and triggered the inflammatory response. Knockdown of PTX3 supported cell growth and prevented apoptosis by blocking PA-inducted nitric oxide (NO) overproduction. Honokiol significantly suppressed the overexpression of PTX3 in PA-inducted HUVECs by inhibiting IκB phosphorylation and the expression of two NF-κB subunits (p50 and p65) in the IKK/IκB/NF-κB signaling pathway. Furthermore, honokiol reduced endothelial cell injury and apoptosis by regulating the expression of inducible NO synthase and endothelial NO synthase, as well as the generation of NO. Honokiol showed an anti-inflammatory effect in PA-inducted HUVECs by significantly inhibiting the generation of interleukin-6 (IL-6), IL-8 and monocyte chemoattractant protein-1. In summary, honokiol repaired endothelial dysfunction by suppressing PTX3 overexpression in an atherosclerotic cell model. PTX3 may be a potential therapeutic target for atherosclerosis. PMID:26138903

  5. Ex vivo differential phase contrast and magnetic resonance imaging for characterization of human carotid atherosclerotic plaques.

    PubMed

    Meletta, Romana; Borel, Nicole; Stolzmann, Paul; Astolfo, Alberto; Klohs, Jan; Stampanoni, Marco; Rudin, Markus; Schibli, Roger; Krämer, Stefanie D; Herde, Adrienne Müller

    2015-10-01

    Non-invasive detection of specific atherosclerotic plaque components related to vulnerability is of high clinical relevance to prevent cerebrovascular events. The feasibility of magnetic resonance imaging (MRI) for characterization of plaque components was already demonstrated. We aimed to evaluate the potential of ex vivo differential phase contrast X-ray tomography (DPC) to accurately characterize human carotid plaque components in comparison to high field multicontrast MRI and histopathology. Two human plaque segments, obtained from carotid endarterectomy, classified according to criteria of the American Heart Association as stable and unstable plaque, were examined by ex vivo DPC tomography and multicontrast MRI (T1-, T2-, and proton density-weighted imaging, magnetization transfer contrast, diffusion-weighted imaging). To identify specific plaque components, the plaques were subsequently sectioned and stained for fibrous and cellular components, smooth muscle cells, hemosiderin, and fibrin. Histological data were then matched with DPC and MR images to define signal criteria for atherosclerotic plaque components. Characteristic structures, such as the lipid and necrotic core covered by a fibrous cap, calcification and hemosiderin deposits were delineated by histology and found with excellent sensitivity, resolution and accuracy in both imaging modalities. DPC tomography was superior to MRI regarding resolution and soft tissue contrast. Ex vivo DPC tomography allowed accurate identification of structures and components of atherosclerotic plaques at different lesion stages, in good correlation with histopathological findings.

  6. Automated tissue characterization of in vivo atherosclerotic plaques by intravascular optical coherence tomography images

    PubMed Central

    Ughi, Giovanni Jacopo; Adriaenssens, Tom; Sinnaeve, Peter; Desmet, Walter; D’hooge, Jan

    2013-01-01

    Intravascular optical coherence tomography (IVOCT) is rapidly becoming the method of choice for the in vivo investigation of coronary artery disease. While IVOCT visualizes atherosclerotic plaques with a resolution <20µm, image analysis in terms of tissue composition is currently performed by a time-consuming manual procedure based on the qualitative interpretation of image features. We illustrate an algorithm for the automated and systematic characterization of IVOCT atherosclerotic tissue. The proposed method consists in a supervised classification of image pixels according to textural features combined with the estimated value of the optical attenuation coefficient. IVOCT images of 64 plaques, from 49 in vivo IVOCT data sets, constituted the algorithm’s training and testing data sets. Validation was obtained by comparing automated analysis results to the manual assessment of atherosclerotic plaques. An overall pixel-wise accuracy of 81.5% with a classification feasibility of 76.5% and per-class accuracy of 89.5%, 72.1% and 79.5% for fibrotic, calcified and lipid-rich tissue respectively, was found. Moreover, measured optical properties were in agreement with previous results reported in literature. As such, an algorithm for automated tissue characterization was developed and validated using in vivo human data, suggesting that it can be applied to clinical IVOCT data. This might be an important step towards the integration of IVOCT in cardiovascular research and routine clinical practice. PMID:23847728

  7. [Atherosclerotic calcification of coronary artery detected by electron beam CT: A new probation of calcific algorithm].

    PubMed

    Li, Wensheng; Song, Zhijian; Zhao, Shumin; Zuo, Huanchen

    2006-08-01

    Electron beam computed tomography (EBCT) can detect the atherosclerotic calcification of coronary artery qualitatively and quantitatively. It was also verified that the atherosclerotic calcification was directly related to the atherosclerotic extent and had a limited relation to the occurrence of coronary heart disease (CHD). So EBCT is one of the good non-invasive methods for predicting the risk of CHD. However, there are some problems in the calcification parameters (calcification area, calcification score) adopted by EBCT which have high variability and low reproducibility. As a result, these parameters have imperfection and need to be improved further. This research provides a new calcification parameter (calcification volume) which makes the use of three dimensional information of all calcific pixels in EBCT scanning images of coronary artery. After experiment in 11 human coronary artery specimens, it was testified that calcification volume had a lower variability than calcification area and calcification score in 25% percentile, median, 75% percentile, Mean, respectively. P value of t test in Mean variability is 0.027, and 0.058. These results suggest that calcification volume may be a new calcification parameter. PMID:17002127

  8. Heparin Cofactor II in Atherosclerotic Lesions from the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) Study

    PubMed Central

    Rau, Jill C.; Deans, Carolyn; Hoffman, Maureane R.; Thomas, David B.; Malcom, Gray T.; Zieske, Arthur W.; Strong, Jack P.; Koch, Gary G.; Church, Frank C.

    2009-01-01

    Heparin cofactor II (HCII) is a serine protease inhibitor (serpin) that has been shown to be a predictor of decreased atherosclerosis in the elderly and protective against atherosclerosis in mice. HCII inhibits thrombin in vitro and HCII-thrombin complexes have been detected in human plasma. Moreover, the mechanism of protection against atherosclerosis in mice was determined to be the inhibition of thrombin. Despite this evidence, the presence of HCII in human atherosclerotic tissue has not been reported. In this study, using samples of coronary arteries obtained from the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study, we explore the local relationship between HCII and (pro)thrombin in atherosclerosis. We found that HCII and (pro)thrombin are co-localized in the lipid-rich necrotic core of atheromas. A significant positive correlation between each protein and the severity of the atherosclerotic lesion was present. These results suggest that HCII is in a position to inhibit thrombin in atherosclerotic lesions where thrombin can exert a proatherogenic inflammatory response. However, these results should be tempered by the additional findings from this, and other studies, that indicate the presence of other plasma proteins (antithrombin, albumin, and α1-protease inhibitor) in the same localized region of the atheroma. PMID:19747479

  9. [Inflammatory-destructive biomarkers of atherosclerotic plaques instability. Study of arterial wall and blood].

    PubMed

    Ragino, Iu I; Cherniavskiĭ, A M; Polonskaia, Ia V; Volkov, A M; Kashtanova, E V; Tsymbal, S Iu; Polovnikova, E M

    2012-01-01

    Concentrations of tumor necrosis factor, interleukin 1- and its receptor antagonist, IL-6, IL-8, IL-18, IL-2, ligand of CD40 receptor (CD40L), high sensitive C-reactive protein (hsCRP), monocyte chemotactic protein -1, endothelial monocyte activating protein II, adhesive molecules (sICAM-1 and sVCAM-1), matrix metalloproteinase (MMP-3, MMP-7, MMP-9), tissue inhibitor of metalloproteinase (TIMP-1) and endothelin-1 were studied in blood and in coronary artery intima/media of men with coronary atherosclerosis without acute coronary syndrome. Blood levels of hsCRP, IL-8, IL-6 and CD40L were higher, while blood levels of sVCAM and TIMP-1 were lower in men with prevalence of unstable atherosclerotic plaques compared to men with prevalence of stable atherosclerotic plaques in coronary arteries. Blood levels of hsCRP, IL-6 and IL-8 correlated with characteristics of coronary artery atherosclerotic plaques instability. Correlation between hsCRP blood level and hsCRP concentration in coronary artery intima/media material was also revealed. PMID:22839584

  10. Fluorescence imaging of macrophages in atherosclerotic plaques using plasmonic gold nanorose

    NASA Astrophysics Data System (ADS)

    Wang, Tianyi; Sapozhnikova, Veronika; Mancuso, J. Jacob; Willsey, Brian; Qiu, Jinze; Ma, Li L.; Li, Xiankai; Johnston, Keith P.; Feldman, Marc D.; Milner, Thomas E.

    2011-03-01

    Macrophages are one of the most important cell types involved in the progression of atherosclerosis which can lead to myocardial infarction. To detect macrophages in atherosclerotic plaques, plasmonic gold nanorose is introduced as a nontoxic contrast agent for fluorescence imaging. We report macrophage cell culture and ex vivo tissue studies to visualize macrophages targeted by nanorose using scanning confocal microscopy. Atherosclerotic lesions were created in the aorta of a New Zealand white rabbit model subjected to a high cholesterol diet and double balloon injury. The rabbit was injected with nanoroses coated with dextran. A HeNe laser at 633 nm was used as an excitation light source and a acousto-optical beam splitter was utilized to collect fluorescence emission in 650-760 nm spectral range. Results of scanning confocal microscopy of macrophage cell culture and ex vivo tissue showed that nanoroses produce a strong fluorescence signal. The presence of nanorose in ex vivo tissue was further confirmed by photothermal wave imaging. These results suggest that scanning confocal microscopy can identify the presence and location of nanorose-loaded macrophages in atherosclerotic plaques.

  11. Nanorose and lipid detection in atherosclerotic plaque using dual-wavelength photothermal wave imaging

    NASA Astrophysics Data System (ADS)

    Wang, Tianyi; Qiu, Jinze; Ma, Li Leo; Li, Xiankai; Sun, Jingjing; Ryoo, Seungyup; Johnston, Keith P.; Feldman, Marc D.; Milner, Thomas E.

    2010-02-01

    Atherosclerosis and specifically rupture of vulnerable plaques account for 23% of all deaths worldwide, far surpassing both infectious diseases and cancer. In atherosclerosis, macrophages can infiltrate plaques which are often associated with lipid deposits. Photothermal wave imaging is based on the periodic thermal modulation of a sample using intensity modulated light. Intensity modulated light enters the sample and is absorbed by targeted chromophores and generates a periodic thermal modulation. We report use of photothermal wave imaging to visualize nanoroses (taken up by macrophages via endocytosis) and lipids in atherosclerotic plaques. Two excitation wavelengths were selected to image nanoroses (800 nm) and lipids (1210 nm). Atherosclerotic plaque in a rabbit abdominal artery was irradiated (800 nm and 1210 nm separately) at a frequency of 4 Hz to generate photothermal waves. The radiometric temperature at the tissue surface was recorded by an infrared (IR) camera over a 10 second time period at the frame rate of 25.6 Hz. Extraction of images (256 × 256 pixels) at various frequencies was performed by Fourier transform at each pixel. Frequency amplitude images were obtained corresponding to 800 nm and 1210 nm laser irradiation. Computed images suggest that the distributions of both nanorose and lipid can be identified in amplitude images at a frequency of 4 Hz. Nanoroses taken up by macrophages are distributed at the edges of lipid deposits. Observation of high concentration of nanoroses in atherosclerotic plaque confirms that nanoroses are present at locations associated with lipid deposits.

  12. A statin-loaded reconstituted high-density lipoprotein nanoparticle inhibits atherosclerotic plaque inflammation

    NASA Astrophysics Data System (ADS)

    Duivenvoorden, Raphaël; Tang, Jun; Cormode, David P.; Mieszawska, Aneta J.; Izquierdo-Garcia, David; Ozcan, Canturk; Otten, Maarten J.; Zaidi, Neeha; Lobatto, Mark E.; van Rijs, Sarian M.; Priem, Bram; Kuan, Emma L.; Martel, Catherine; Hewing, Bernd; Sager, Hendrik; Nahrendorf, Matthias; Randolph, Gwendalyn J.; Stroes, Erik S. G.; Fuster, Valentin; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.

    2014-01-01

    Inflammation is a key feature of atherosclerosis and a target for therapy. Statins have potent anti-inflammatory properties but these cannot be fully exploited with oral statin therapy due to low systemic bioavailability. Here we present an injectable reconstituted high-density lipoprotein (rHDL) nanoparticle carrier vehicle that delivers statins to atherosclerotic plaques. We demonstrate the anti-inflammatory effect of statin-rHDL in vitro and show that this effect is mediated through the inhibition of the mevalonate pathway. We also apply statin-rHDL nanoparticles in vivo in an apolipoprotein E-knockout mouse model of atherosclerosis and show that they accumulate in atherosclerotic lesions in which they directly affect plaque macrophages. Finally, we demonstrate that a 3-month low-dose statin-rHDL treatment regimen inhibits plaque inflammation progression, while a 1-week high-dose regimen markedly decreases inflammation in advanced atherosclerotic plaques. Statin-rHDL represents a novel potent atherosclerosis nanotherapy that directly affects plaque inflammation.

  13. Anti-Atherosclerotic and Anti-Inflammatory Actions of Sesame Oil

    PubMed Central

    Narasimhulu, Chandrakala Aluganti; Selvarajan, Krithika; Litvinov, Dmitry

    2015-01-01

    Abstract Atherosclerosis, a major form of cardiovascular disease, has now been recognized as a chronic inflammatory disease. Nonpharmacological means of treating chronic diseases have gained attention recently. We previously reported that sesame oil has anti-atherosclerotic properties. In this study, we have determined the mechanisms by which sesame oil might modulate atherosclerosis by identifying genes and inflammatory markers. Low-density lipoprotein receptor knockout (LDLR−/−) female mice were fed with either an atherogenic diet or an atherogenic diet reformulated with sesame oil (sesame oil diet). Plasma lipids and atherosclerotic lesions were quantified after 3 months of feeding. Plasma samples were used for cytokine analysis. RNA was extracted from the liver tissue and used for global gene arrays. The sesame oil diet significantly reduced atherosclerotic lesions, plasma cholesterol, triglyceride, and LDL cholesterol levels in LDLR−/− mice. Plasma inflammatory cytokines, such as MCP-1, RANTES, IL-1α, IL-6, and CXCL-16, were significantly reduced, demonstrating an anti-inflammatory property of sesame oil. Gene array analysis showed that sesame oil induced many genes, including ABCA1, ABCA2, APOE, LCAT, and CYP7A1, which are involved in cholesterol metabolism and reverse cholesterol transport. In conclusion, our studies suggest that a sesame oil-enriched diet could be an effective nonpharmacological treatment for atherosclerosis by controlling inflammation and regulating lipid metabolism. PMID:25562618

  14. A Proteomic Focus on the Alterations Occurring at the Human Atherosclerotic Coronary Intima*

    PubMed Central

    de la Cuesta, Fernando; Alvarez-Llamas, Gloria; Maroto, Aroa S.; Donado, Alicia; Zubiri, Irene; Posada, Maria; Padial, Luis R.; Pinto, Angel G.; Barderas, Maria G.; Vivanco, Fernando

    2011-01-01

    Coronary atherosclerosis still represents the major cause of mortality in western societies. Initiation of atherosclerosis occurs within the intima, where major histological and molecular changes are produced during pathogenesis. So far, proteomic analysis of the atherome plaque has been mainly tackled by the analysis of the entire tissue, which may be a challenging approach because of the great complexity of this sample in terms of layers and cell type composition. Based on this, we aimed to study the intimal proteome from the human atherosclerotic coronary artery. For this purpose, we analyzed the intimal layer from human atherosclerotic coronaries, which were isolated by laser microdissection, and compared with those from preatherosclerotic coronary and radial arteries, using a two-dimensional Differential-In-Gel-Electrophoresis (DIGE) approach. Results have pointed out 13 proteins to be altered (seven up-regulated and six down-regulated), which are implicated in the migrative capacity of vascular smooth muscle cells, extracellular matrix composition, coagulation, apoptosis, heat shock response, and intraplaque hemorrhage deposition. Among these, three proteins (annexin 4, myosin regulatory light 2, smooth muscle isoform, and ferritin light chain) constitute novel atherosclerotic coronary intima proteins, because they were not previously identified at this human coronary layer. For this reason, these novel proteins were validated by immunohistochemistry, together with hemoglobin and vimentin, in an independent cohort of arteries. PMID:21248247

  15. Influence of particle size on the distributions of liposomes to atherosclerotic lesions in mice.

    PubMed

    Chono, Sumio; Tauchi, Yoshihiko; Morimoto, Kazuhiro

    2006-01-01

    In order to confirm the efficacy of liposomes as a drug carrier for atherosclerotic therapy, the influence of particle size on the distribution of liposomes to atherosclerotic lesions in mice was investigated. In brief, liposomes of three different particle sizes (500, 200, and 70 nm) were prepared, and the uptake of liposomes by the macrophages and foam cells in vitro and the biodistributions of liposomes administered intravenously to atherogenic mice in vivo were examined. The uptake by the macrophages and foam cells increased with the increase in particle size. Although the elimination rate from the blood circulation and the hepatic and splenic distribution increased with the increase in particle size in atherogenic mice, the aortic distribution was independent of the particle size. The aortic distribution of 200 nm liposomes was the highest in comparison with the other sizes. Surprisingly, the aortic distribution of liposomes in vivo did not correspond with the uptake by macrophages and foam cells in vitro. These results suggest that there is an optimal size for the distribution of liposomes to atherosclerotic lesions.

  16. Detecting microcalcifications in atherosclerotic plaques by a simple trichromic staining method for epoxy embedded carotid endarterectomies

    PubMed Central

    Relucenti, M.; Heyn, R.; Petruzziello, L.; Pugliese, G.; Taurino, M.; Familiari, G.

    2010-01-01

    Atherosclerotic plaques have a high probability of undergoing rapid progression to stenosis, becoming responsible of acute coronary syndrome or stroke. Microcalcifications may act as enhancers of atherosclerotic plaque vulnerability. Considering that calcifications with a diameter smalller than 10 µm in paraffin embedded tissue are rather difficult to detect, our aim was to analyze microcalcifications on semithin sections from epoxy resin embedded samples of carotid endarterectomies using an original trichromic stain (methylene blue-azur B - basic fuchsine - alizarin red). We have compared samples stained either with our method, methylene blue-azur B alone or with Von Kossa staining, and methylene blue-azur B -basic fuchsine alone or with Von Kossa staining. Our method resulted to be simple and fast (ca. 2 min), it gives a sharp general contrast for all structures and allows to easy identify collagen and elastin. In addition, gray-green colour associated to intracellular lipid droplets evidences foam cells, which are particularly abundant in endarterectomies samples. Mast cells and their metachromatic granules are also well recognized. Calcifications over 0,5 µm are clearly recognizable. In conclusion, microcalcifications are clearly distinguished from the extracellular matrix in spite of their reduced dimensions. Methylene blue-azur B-basic fuchsine-alizarin red method is easy to use, reproducible, and is particularly suitable for the identification of microcalcifications in the morphological analysis of atherosclerotic plaques. PMID:20819772

  17. Anti-atherosclerotic and anti-inflammatory actions of sesame oil.

    PubMed

    Narasimhulu, Chandrakala Aluganti; Selvarajan, Krithika; Litvinov, Dmitry; Parthasarathy, Sampath

    2015-01-01

    Atherosclerosis, a major form of cardiovascular disease, has now been recognized as a chronic inflammatory disease. Nonpharmacological means of treating chronic diseases have gained attention recently. We previously reported that sesame oil has anti-atherosclerotic properties. In this study, we have determined the mechanisms by which sesame oil might modulate atherosclerosis by identifying genes and inflammatory markers. Low-density lipoprotein receptor knockout (LDLR(-/-)) female mice were fed with either an atherogenic diet or an atherogenic diet reformulated with sesame oil (sesame oil diet). Plasma lipids and atherosclerotic lesions were quantified after 3 months of feeding. Plasma samples were used for cytokine analysis. RNA was extracted from the liver tissue and used for global gene arrays. The sesame oil diet significantly reduced atherosclerotic lesions, plasma cholesterol, triglyceride, and LDL cholesterol levels in LDLR(-/-) mice. Plasma inflammatory cytokines, such as MCP-1, RANTES, IL-1α, IL-6, and CXCL-16, were significantly reduced, demonstrating an anti-inflammatory property of sesame oil. Gene array analysis showed that sesame oil induced many genes, including ABCA1, ABCA2, APOE, LCAT, and CYP7A1, which are involved in cholesterol metabolism and reverse cholesterol transport. In conclusion, our studies suggest that a sesame oil-enriched diet could be an effective nonpharmacological treatment for atherosclerosis by controlling inflammation and regulating lipid metabolism. PMID:25562618

  18. Aqueous extract of rhubarb stabilizes vulnerable atherosclerotic plaques due to depression of inflammation and lipid accumulation.

    PubMed

    Liu, Yunfang; Yan, Fangfang; Liu, Yan; Zhang, Cheng; Yu, Huiming; Zhang, Yun; Zhao, Yuxia

    2008-07-01

    The study evaluated the effect of the traditional Chinese medicine rhubarb on the stability of atherosclerotic plaque. Atherosclerotic lesions were induced in rabbits through balloon injury with a high-cholesterol diet and then were divided into a control group, a rhubarb group and a simvastatin group. At week 24 recombinant-p53 adenoviruses were locally delivered to the atherosclerotic plaques. At week 26 plaque rupture was triggered by the intra-arterial Chinese Russell's viper venom and histamine. Serological, ultrasonographic, pathologic, immunohistochemical and gene expression studies were performed. The results showed that the incidence of plaque rupture in the rhubarb group and the simvastatin group was significantly lower than that in the control group (42.86% and 35.71% versus 80.00%, both p < 0.05). Serum TC, LDL-C (p < 0.05-0.01), IMT (both p < 0.01), PA (both p < 0.01), PB (%) (both p < 0.01) and the mRNA and protein expressions of TLR2, TLR4 and NF-kappaB (p < 0.05, 0.01, respectively) in the rhubarb group and the simvastatin group were significantly lower than those in the control group. In contrast, AIIc% (both p < 0.05) in the two treatment groups were significantly higher than those in the control group. These results suggest that rhubarb has antiatherosclerotic and plaque-stabilizing properties due to antiinflammation and lipid-lowering effects.

  19. In vivo fluorescence imaging of atherosclerotic plaques with activatable cell-penetrating peptides targeting thrombin activity†

    PubMed Central

    Olson, Emilia S.; Whitney, Michael A.; Friedman, Beth; Aguilera, Todd A.; Crisp, Jessica L.; Baik, Fred M.; Jiang, Tao; Baird, Stephen M.; Tsimikas, Sotirios; Tsien, Roger Y.

    2012-01-01

    Thrombin and other coagulation enzymes have been shown to be important during atherosclerotic disease development. Study of these proteases is currently limited because of lack of robust molecular imaging agents for imaging protease activity in vivo. Activatable cell penetrating peptides (ACPPs) have been used to monitor MMP activity in tumors and, in principle, can be modified to detect other proteases. We have developed a probe that incorporates the peptide sequence DPRSFL from the proteinase activated receptor 1 (PAR-1) into an ACPP and shown that it is preferentially cleaved by purified thrombin. Active thrombin in serum cleaves DPRSFL–ACPP with >90% inhibition by lepirudin or argatroban. The DPRSFL–ACPP cleavage product accumulated in advanced atherosclerotic lesions in living mice, with 85% reduction in retention upon pre-injection of mice with hirudin. Uptake of the ACPP cleavage product was highest in plaques with histological features associated with more severe disease. Freshly resected human atheromas bathed in DPRSFL–ACPP retained 63% greater cleavage product compared to control ACPP. In conclusion, DPRSFL–ACPP can be used to study thrombin activity in coagulation and atherosclerosis with good spatial and temporal resolution. Thrombin-sensitive ACPPs may be developed into probes for early detection and intraoperative imaging of high risk atherosclerotic plaques. PMID:22534729

  20. Accelerator system and method of accelerating particles

    NASA Technical Reports Server (NTRS)

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  1. Insulin resistance, small LDL particles, and risk for atherosclerotic disease.

    PubMed

    Toth, Peter P

    2014-01-01

    There is a global epidemic of obesity, metabolic syndrome, and diabetes mellitus. Insulin resistance (IR) is etiologic for both metabolic syndrome and diabetes mellitus. IR induces a broad range of toxic systemic effects, including dyslipidemia, hypertension, hyperglycemia, increased production of advanced glycosylation end products, increased inflammatory tone, as well as a prothrombotic and pro-oxidative state. Patients with IR are highly vulnerable to the development of accelerated atherosclerosis as well its clinical sequelae, including coronary artery disease and myocardial infarction, carotid artery disease and ischemic stroke, peripheral arterial disease and claudication/lower extremity amputation, and coronary mortality. Among the most important risk factors patients afflicted with IR develop is the so-called atherogenic lipid triad: large numbers of small, dense low-density lipoprotein (sdLDL) particles, hypertriglyceridemia, and low serum concentrations of high-density lipoprotein cholesterol. Though controversial, much recent evidence suggests that the formation of sdLDL particles in the setting of IR is an important metabolic transition. Some studies suggest that these smaller particles are more atherogenic than their larger, more buoyant counterparts. At least part of the explanation for the apparent augmented atherogenicity of small LDL particles is their reduced systemic clearance by the LDL receptor, increased vulnerability to oxidation rendering them more apt for scavenging by macrophages, and possible increased flux into the subendothelial space of arterial walls. Numerous small studies suggest that sdLDL is highly correlated with cardiovascular events. Cardiovascular medicine is in need of a large prospective, randomized study that would more definitively investigate the impact of small, dense LDL (sdLDL) on risk for cardiovascular disease and whether therapeutic interventions designed to specifically reduce the burden of sdLDL are associated

  2. Prospects for Accelerator Technology

    NASA Astrophysics Data System (ADS)

    Todd, Alan

    2011-02-01

    Accelerator technology today is a greater than US$5 billion per annum business. Development of higher-performance technology with improved reliability that delivers reduced system size and life cycle cost is expected to significantly increase the total accelerator technology market and open up new application sales. Potential future directions are identified and pitfalls in new market penetration are considered. Both of the present big market segments, medical radiation therapy units and semiconductor ion implanters, are approaching the "maturity" phase of their product cycles, where incremental development rather than paradigm shifts is the norm, but they should continue to dominate commercial sales for some time. It is anticipated that large discovery-science accelerators will continue to provide a specialty market beset by the unpredictable cycles resulting from the scale of the projects themselves, coupled with external political and economic drivers. Although fraught with differing market entry difficulties, the security and environmental markets, together with new, as yet unrealized, industrial material processing applications, are expected to provide the bulk of future commercial accelerator technology growth.

  3. Observations of particle acceleration in solar flares

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.

    1979-01-01

    Solar flares provide several examples of nonthermal particle acceleration. The paper reviews the information gained about these processes via X-ray and gamma-ray astronomy, which can presently distinguish among three separate particle-acceleration processes at the sun: an impulsive accelerator of more than 20 keV electrons, a gradual accelerator of more than 20 keV electrons, and a gradual accelerator of more than 10 MeV ions. The acceleration energy efficiency (total particle energy divided by total flare energy) of any of these mechanisms cannot be less than about 0.1%, although the gradual acceleration does not occur in every flare. The observational material suggests that both the impulsive and gradual accelerations take place preferentially in closed magnetic-field structures, but that the electrons decay in these traps before they can escape. The ions escape very efficiently.

  4. Superdiffusive shock acceleration and short acceleration times at interplanetary shocks

    NASA Astrophysics Data System (ADS)

    Perri, Silvia; Zimbardo, Gaetano

    2016-04-01

    The analysis of time profiles of particles accelerated at interplanetary shock waves has shown evidence for superdiffusive transport in the upstream region. Superdiffusive transport is characterized by a mean square displacement that grows faster than linearly in time and by non Gaussian statistics for the distribution of the particle jump lengths. In the superdiffusive framework it has been shown that particle time profiles upstream of a planar shock decay as power laws, at variance with exponential particle time profiles predicted in the case of diffusive transport. A large number of interplanetary shocks, including coronal mass ejection driven shocks, exhibit energetic particle time profiles that decay as power laws far upstream. In order to take this evidence into account, we have extended the standard theory of diffusive shock acceleration to the case of particle superdiffusive transport (superdiffusive shock acceleration). This has allowed us to derive both hard energy spectral indices and short acceleration times. This new theory has been tested for a number of interplanetary shock waves, observed by the Ulysses and the ACE spacecraft, and for the termination shock. The superdiffusive shock acceleration leads to a strong reduction of the acceleration times (even of about one order of magnitude) with respect to the diffusive shock acceleration. Thus, this new framework provides a substantial advancement in the understanding of the processes of particle acceleration and particle transport, which are among the main objectives of the new Solar Probe and Solar Orbiter space missions.

  5. Modelling multi-phase liquid-sediment scour and resuspension induced by rapid flows using Smoothed Particle Hydrodynamics (SPH) accelerated with a Graphics Processing Unit (GPU)

    NASA Astrophysics Data System (ADS)

    Fourtakas, G.; Rogers, B. D.

    2016-06-01

    A two-phase numerical model using Smoothed Particle Hydrodynamics (SPH) is applied to two-phase liquid-sediments flows. The absence of a mesh in SPH is ideal for interfacial and highly non-linear flows with changing fragmentation of the interface, mixing and resuspension. The rheology of sediment induced under rapid flows undergoes several states which are only partially described by previous research in SPH. This paper attempts to bridge the gap between the geotechnics, non-Newtonian and Newtonian flows by proposing a model that combines the yielding, shear and suspension layer which are needed to predict accurately the global erosion phenomena, from a hydrodynamics prospective. The numerical SPH scheme is based on the explicit treatment of both phases using Newtonian and the non-Newtonian Bingham-type Herschel-Bulkley-Papanastasiou constitutive model. This is supplemented by the Drucker-Prager yield criterion to predict the onset of yielding of the sediment surface and a concentration suspension model. The multi-phase model has been compared with experimental and 2-D reference numerical models for scour following a dry-bed dam break yielding satisfactory results and improvements over well-known SPH multi-phase models. With 3-D simulations requiring a large number of particles, the code is accelerated with a graphics processing unit (GPU) in the open-source DualSPHysics code. The implementation and optimisation of the code achieved a speed up of x58 over an optimised single thread serial code. A 3-D dam break over a non-cohesive erodible bed simulation with over 4 million particles yields close agreement with experimental scour and water surface profiles.

  6. Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of aortic atherosclerotic thrombi and ulcers.

    PubMed

    Elsayed, Mahmoud; Bulur, Serkan; Kalla, Aditi; Ahmed, Mustafa I; Hsiung, Ming C; Uygur, Begum; Alagic, Nermina; Sungur, Aylin; Singh, Satinder; Nanda, Navin C

    2016-08-01

    We present two cases in whom live/real time three-dimensional transesophageal echocardiography (3DTEE) provided incremental value in the assessment of atherosclerotic disease in the aorta. In one patient, it identified additional atherosclerotic ulcers as well as thrombi within them which were missed by two-dimensional (2D) TEE. In both cases, the size of the large mobile atherosclerotic plaque was underestimated by 2DTEE as compared with 3DTEE. Furthermore, 3DTEE provided volume quantification of the thrombi and ulcers which is not possible by 2DTEE. The echocardiographic findings of atherosclerotic plaques were confirmed by computed tomography in one patient and by surgery in the other.

  7. Menopause accelerates biological aging.

    PubMed

    Levine, Morgan E; Lu, Ake T; Chen, Brian H; Hernandez, Dena G; Singleton, Andrew B; Ferrucci, Luigi; Bandinelli, Stefania; Salfati, Elias; Manson, JoAnn E; Quach, Austin; Kusters, Cynthia D J; Kuh, Diana; Wong, Andrew; Teschendorff, Andrew E; Widschwendter, Martin; Ritz, Beate R; Absher, Devin; Assimes, Themistocles L; Horvath, Steve

    2016-08-16

    Although epigenetic processes have been linked to aging and disease in other systems, it is not yet known whether they relate to reproductive aging. Recently, we developed a highly accurate epigenetic biomarker of age (known as the "epigenetic clock"), which is based on DNA methylation levels. Here we carry out an epigenetic clock analysis of blood, saliva, and buccal epithelium using data from four large studies: the Women's Health Initiative (n = 1,864); Invecchiare nel Chianti (n = 200); Parkinson's disease, Environment, and Genes (n = 256); and the United Kingdom Medical Research Council National Survey of Health and Development (n = 790). We find that increased epigenetic age acceleration in blood is significantly associated with earlier menopause (P = 0.00091), bilateral oophorectomy (P = 0.0018), and a longer time since menopause (P = 0.017). Conversely, epigenetic age acceleration in buccal epithelium and saliva do not relate to age at menopause; however, a higher epigenetic age in saliva is exhibited in women who undergo bilateral oophorectomy (P = 0.0079), while a lower epigenetic age in buccal epithelium was found for women who underwent menopausal hormone therapy (P = 0.00078). Using genetic data, we find evidence of coheritability between age at menopause and epigenetic age acceleration in blood. Using Mendelian randomization analysis, we find that two SNPs that are highly associated with age at menopause exhibit a significant association with epigenetic age acceleration. Overall, our Mendelian randomization approach and other lines of evidence suggest that menopause accelerates epigenetic aging of blood, but mechanistic studies will be needed to dissect cause-and-effect relationships further. PMID:27457926

  8. Introduction to Particle Acceleration in the Cosmos

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Horwitz, J. L.; Perez, J.; Quenby, J.

    2005-01-01

    Accelerated charged particles have been used on Earth since 1930 to explore the very essence of matter, for industrial applications, and for medical treatments. Throughout the universe nature employs a dizzying array of acceleration processes to produce particles spanning twenty orders of magnitude in energy range, while shaping our cosmic environment. Here, we introduce and review the basic physical processes causing particle acceleration, in astrophysical plasmas from geospace to the outer reaches of the cosmos. These processes are chiefly divided into four categories: adiabatic and other forms of non-stochastic acceleration, magnetic energy storage and stochastic acceleration, shock acceleration, and plasma wave and turbulent acceleration. The purpose of this introduction is to set the stage and context for the individual papers comprising this monograph.

  9. Network acceleration techniques

    NASA Technical Reports Server (NTRS)

    Crowley, Patricia (Inventor); Awrach, James Michael (Inventor); Maccabe, Arthur Barney (Inventor)

    2012-01-01

    Splintered offloading techniques with receive batch processing are described for network acceleration. Such techniques offload specific functionality to a NIC while maintaining the bulk of the protocol processing in the host operating system ("OS"). The resulting protocol implementation allows the application to bypass the protocol processing of the received data. Such can be accomplished this by moving data from the NIC directly to the application through direct memory access ("DMA") and batch processing the receive headers in the host OS when the host OS is interrupted to perform other work. Batch processing receive headers allows the data path to be separated from the control path. Unlike operating system bypass, however, the operating system still fully manages the network resource and has relevant feedback about traffic and flows. Embodiments of the present disclosure can therefore address the challenges of networks with extreme bandwidth delay products (BWDP).

  10. Atherosclerotic inferior mesenteric artery stenosis resulting in large intestinal hypoperfusion: a paradigm shift in the diagnosis and management of symptomatic chronic mesenteric ischemia.

    PubMed

    Lotun, Kapildeo; Shetty, Ranjith; Topaz, On

    2012-11-01

    Symptomatic chronic mesenteric ischemia results from intestinal hypoperfusion and is classically thought to result from involvement of two or more mesenteric arteries. The celiac artery and superior mesenteric artery are most frequently implicated in this disease process, and their involvement usually results in symptoms of small intestinal ischemia. Symptomatic chronic mesenteric ischemia resulting predominantly from inferior mesenteric artery involvement has largely been overlooked but does gives rise to its own, unique clinical presentation with symptoms resulting from large intestinal ischemia. We present four patients with atherosclerotic inferior mesenteric artery stenosis with symptomatic chronic mesenteric ischemia that have unique clinical presentations consistent with large intestinal ischemia that resolved following percutaneous endovascular treatment of the inferior mesenteric artery stenosis. These cases represent a novel approach to the diagnosis and management of this disease process and may warrant a further subclassification of chronic mesenteric ischemia into chronic small intestinal ischemia and chronic large intestinal ischemia.

  11. Focal toxicity of oxysterols in vascular smooth muscle cell culture. A model of the atherosclerotic core region.

    PubMed Central

    Guyton, J. R.; Black, B. L.; Seidel, C. L.

    1990-01-01

    Cell necrosis and reactive cellular processes in and near the atherosclerotic core region might result from short-range interactions with toxic lipids. To model these interactions in cell culture, focal crystalline deposits of cholestane-3 beta,5 alpha,6 beta-triol, 25-OH cholesterol, and cholesterol were overlaid by a collagen gel, on which canine aortic smooth muscle cells were seeded. Oxysterols, but not cholesterol, caused focally decreased plating efficiency and cell death, leading to the formation of a persistent circular gap in the cell culture. Cholestanetriol was largely removed from the culture dishes over 3 to 4 weeks, whereas cholesterol and 25-OH cholesterol were largely retained. Smooth muscle cells were motile even in proximity to oxysterol crystals, with occasional suicidal migration toward the crystals. Chemoattraction, however, could not be demonstrated. Despite toxicity, cholestanetriol did not appear to alter the fraction of cells exhibiting 3H-thymidine uptake, even in areas close to the crystals. Thus, oxysterols may be toxic to some cells, without causing major impairment of the migration and proliferation of nearby cells. This would allow the simultaneous occurrence of cell death and proliferation evident in atherosclerosis. Images Figure 2 Figure 4 Figure 5 PMID:2201200

  12. Cascaded target normal sheath acceleration

    SciTech Connect

    Wang, W. P.; Shen, B. F.; Zhang, X. M.; Wang, X. F.; Xu, J. C.; Zhao, X. Y.; Yu, Y. H.; Yi, L. Q.; Shi, Y.; Zhang, L. G.; Xu, T. J.; Xu, Z. Z.

    2013-11-15

    A cascaded target normal sheath acceleration (TNSA) scheme is proposed to simultaneously increase energy and improve energy spread of a laser-produced mono-energetic proton beam. An optimum condition that uses the maximum sheath field to accelerate the center of the proton beam is theoretically found and verified by two-dimensional particle-in-cell simulations. An initial 10 MeV proton beam is accelerated to 21 MeV with energy spread decreased from 5% to 2% under the optimum condition during the process of the cascaded TNSA. The scheme opens a way to scale proton energy lineally with laser energy.

  13. SUPERDIFFUSIVE SHOCK ACCELERATION

    SciTech Connect

    Perri, S.; Zimbardo, G.

    2012-05-10

    The theory of diffusive shock acceleration is extended to the case of superdiffusive transport, i.e., when the mean square deviation grows proportionally to t{sup {alpha}}, with {alpha} > 1. Superdiffusion can be described by a statistical process called Levy random walk, in which the propagator is not a Gaussian but it exhibits power-law tails. By using the propagator appropriate for Levy random walk, it is found that the indices of energy spectra of particles are harder than those obtained where a normal diffusion is envisaged, with the spectral index decreasing with the increase of {alpha}. A new scaling for the acceleration time is also found, allowing substantially shorter times than in the case of normal diffusion. Within this framework we can explain a number of observations of flat spectra in various astrophysical and heliospheric contexts, for instance, for the Crab Nebula and the termination shock of the solar wind.

  14. EM Structure Based and Vacuum Acceleration

    SciTech Connect

    Colby, E.R.; /SLAC

    2005-09-27

    The importance of particle acceleration may be judged from the number of applications which require some sort of accelerated beam. In addition to accelerator-based high energy physics research, non-academic applications include medical imaging and treatment, structural biology by x-ray diffraction, pulse radiography, cargo inspection, material processing, food and medical instrument sterilization, and so on. Many of these applications are already well served by existing technologies and will profit only marginally from developments in accelerator technology. Other applications are poorly served, such as structural biology, which is conducted at synchrotron radiation facilities, and medical treatment using proton accelerators, the machines for which are rare because they are complex and costly. Developments in very compact, high brightness and high gradient accelerators will change how accelerators are used for such applications, and potentially enable new ones. Physical and technical issues governing structure-based and vacuum acceleration of charged particles are reviewed, with emphasis on practical aspects.

  15. Chronic intermittent mental stress promotes atherosclerotic plaque vulnerability, myocardial infarction and sudden death in mice.

    PubMed

    Roth, Lynn; Rombouts, Miche; Schrijvers, Dorien M; Lemmens, Katrien; De Keulenaer, Gilles W; Martinet, Wim; De Meyer, Guido R Y

    2015-09-01

    Vulnerable atherosclerotic plaques are prone to plaque rupture leading to acute cardiovascular syndromes and death. Elucidating the risk of plaque rupture is important to define better therapeutic or preventive strategies. In the present study, we investigated the effect of chronic intermittent mental stress on atherosclerotic plaque stability and cardiovascular mortality in apolipoprotein E-deficient (ApoE(-/-)) mice with a heterozygous mutation in the fibrillin-1 gene (Fbn1(C1039G+/)(-)). This mouse model displays exacerbated atherosclerosis with spontaneous plaque ruptures, myocardial infarction and sudden death, when fed a Western-type diet (WD). Female ApoE(-/-)Fbn1(C1039G+/-) mice were fed a WD for up to 25 weeks. After 10 weeks WD, mice were divided in a control (n = 27) and mental stress (n = 29) group. The chronic intermittent mental stress protocol consisted of 3 triggers: water avoidance, damp bedding and restraint stress, in a randomly assigned order lasting 6 h every weekday for 15 weeks. Chronic intermittent mental stress resulted in a significant increase in the amount of macrophages in atherosclerotic plaques of the proximal ascending aorta, whereas type I collagen and fibrous cap thickness were decreased. The coronary arteries of mental stress-treated mice showed larger plaques, more stenosis, and an increased degree of perivascular fibrosis. Moreover, myocardial infarctions occurred more frequently in the mental stress group. As compared to the control group, the survival of stressed ApoE(-/-)Fbn1(C1039G+/-) mice decreased from 67% to 52% at 25 weeks WD, presumably due to myocardial infarctions. In conclusion, chronic intermittent mental stress promotes plaque instability, myocardial infarctions, and mortality of ApoE(-/-)Fbn1(C1039G+/-) mice. PMID:26233915

  16. Treatment of patients with aortic atherosclerotic disease with paclitaxel-associated lipid nanoparticles

    PubMed Central

    Shiozaki, Afonso A.; Senra, Tiago; Morikawa, Aleksandra T.; Deus, Débora F.; Paladino, Antonio T; Pinto, Ibraim M.F.; Maranhão, Raul C.

    2016-01-01

    OBJECTIVE: The toxicity of anti-cancer chemotherapeutic agents can be reduced by associating these compounds, such as the anti-proliferative agent paclitaxel, with a cholesterol-rich nanoemulsion (LDE) that mimics the lipid composition of low-density lipoprotein (LDL). When injected into circulation, the LDE concentrates the carried drugs in neoplastic tissues and atherosclerotic lesions. In rabbits, atherosclerotic lesion size was reduced by 65% following LDE-paclitaxel treatment. The current study aimed to test the effectiveness of LDE-paclitaxel on inpatients with aortic atherosclerosis. METHODS: This study tested a 175 mg/m2 body surface area dose of LDE-paclitaxel (intravenous administration, 3/3 weeks for 6 cycles) in patients with aortic atherosclerosis who were aged between 69 and 86 yrs. A control group of 9 untreated patients with aortic atherosclerosis (72-83 yrs) was also observed. RESULTS: The LDE-paclitaxel treatment elicited no important clinical or laboratory toxicities. Images were acquired via multiple detector computer tomography angiography (64-slice scanner) before treatment and at 1-2 months after treatment. The images showed that the mean plaque volume in the aortic artery wall was reduced in 4 of the 8 patients, while in 3 patients it remained unchanged and in one patient it increased. In the control group, images were acquired twice with an interval of 6-8 months. None of the patients in this group exhibited a reduction in plaque volume; in contrast, the plaque volume increased in three patients and remained stable in four patients. During the study period, one death unrelated to the treatment occurred in the LDE-paclitaxel group and one death occurred in the control group. CONCLUSION: Treatment with LDE-paclitaxel was tolerated by patients with cardiovascular disease and showed the potential to reduce atherosclerotic lesion size. PMID:27626473

  17. Treatment of patients with aortic atherosclerotic disease with paclitaxel-associated lipid nanoparticles

    PubMed Central

    Shiozaki, Afonso A.; Senra, Tiago; Morikawa, Aleksandra T.; Deus, Débora F.; Paladino, Antonio T; Pinto, Ibraim M.F.; Maranhão, Raul C.

    2016-01-01

    OBJECTIVE: The toxicity of anti-cancer chemotherapeutic agents can be reduced by associating these compounds, such as the anti-proliferative agent paclitaxel, with a cholesterol-rich nanoemulsion (LDE) that mimics the lipid composition of low-density lipoprotein (LDL). When injected into circulation, the LDE concentrates the carried drugs in neoplastic tissues and atherosclerotic lesions. In rabbits, atherosclerotic lesion size was reduced by 65% following LDE-paclitaxel treatment. The current study aimed to test the effectiveness of LDE-paclitaxel on inpatients with aortic atherosclerosis. METHODS: This study tested a 175 mg/m2 body surface area dose of LDE-paclitaxel (intravenous administration, 3/3 weeks for 6 cycles) in patients with aortic atherosclerosis who were aged between 69 and 86 yrs. A control group of 9 untreated patients with aortic atherosclerosis (72-83 yrs) was also observed. RESULTS: The LDE-paclitaxel treatment elicited no important clinical or laboratory toxicities. Images were acquired via multiple detector computer tomography angiography (64-slice scanner) before treatment and at 1-2 months after treatment. The images showed that the mean plaque volume in the aortic artery wall was reduced in 4 of the 8 patients, while in 3 patients it remained unchanged and in one patient it increased. In the control group, images were acquired twice with an interval of 6-8 months. None of the patients in this group exhibited a reduction in plaque volume; in contrast, the plaque volume increased in three patients and remained stable in four patients. During the study period, one death unrelated to the treatment occurred in the LDE-paclitaxel group and one death occurred in the control group. CONCLUSION: Treatment with LDE-paclitaxel was tolerated by patients with cardiovascular disease and showed the potential to reduce atherosclerotic lesion size.

  18. Arsenic exacerbates atherosclerotic lesion formation and inflammation in ApoE-/- mice

    SciTech Connect

    Srivastava, Sanjay; Vladykovskaya, Elena N.; Haberzettl, Petra; Sithu, Srinivas D.; D'Souza, Stanley E.; States, J. Christopher

    2009-11-15

    Exposure to arsenic-contaminated water has been shown to be associated with cardiovascular disease, especially atherosclerosis. We examined the effect of arsenic exposure on atherosclerotic lesion formation, lesion composition and nature in ApoE-/- mice. Early post-natal exposure (3-week-old mice exposed to 49 ppm arsenic as NaAsO{sub 2} in drinking water for 7 weeks) increased the atherosclerotic lesion formation by 3- to 5-fold in the aortic valve and the aortic arch, without affecting plasma cholesterol. Exposure to arsenic for 13 weeks (3-week-old mice exposed to 1, 4.9 and 49 ppm arsenic as NaAsO{sub 2} in drinking water) increased the lesion formation and macrophage accumulation in a dose-dependent manner. Temporal studies showed that continuous arsenic exposure significantly exacerbated the lesion formation throughout the aortic tree at 16 and 36 weeks of age. Withdrawal of arsenic for 12 weeks after an initial exposure for 21 weeks (to 3-week-old mice) significantly decreased lesion formation as compared with mice continuously exposed to arsenic. Similarly, adult exposure to 49 ppm arsenic for 24 weeks, starting at 12 weeks of age increased lesion formation by 2- to 3.6-fold in the aortic valve, the aortic arch and the abdominal aorta. Lesions of arsenic-exposed mice displayed a 1.8-fold increase in macrophage accumulation whereas smooth muscle cell and T-lymphocyte contents were not changed. Expression of pro-inflammatory chemokine MCP-1 and cytokine IL-6 and markers of oxidative stress, protein-HNE and protein-MDA adducts were markedly increased in lesions of arsenic-exposed mice. Plasma concentrations of MCP-1, IL-6 and MDA were also significantly elevated in arsenic-exposed mice. These data suggest that arsenic exposure increases oxidative stress, inflammation and atherosclerotic lesion formation.

  19. Anti-atherosclerotic potential of gossypetin via inhibiting LDL oxidation and foam cell formation

    SciTech Connect

    Chen, Jing-Hsien; Tsai, Chia-Wen; Wang, Chi-Ping; Lin, Hui-Hsuan

    2013-10-15

    Gossypetin, a flavone originally isolated from Hibiscus species, has been shown to possess antioxidant, antimicrobial, and antimutagenic activities. Here, we investigated the mechanism(s) underlying the anti-atherosclerotic potential of gossypetin. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity assay showed that the addition of > 50 μM of gossypetin could scavenge over 50% of DPPH radicals. The inhibitory effects of gossypetin on the lipid and protein oxidation of LDL were defined by thiobarbituric acid reactive substance (TBARS) assay, the relative electrophoretic mobility (REM) of oxidized LDL (ox-LDL), and fragmentation of apoB in the Cu{sup 2+}-induced oxidation of LDL. Gossypetin showed potential in reducing ox-LDL-induced foam cell formation and intracellular lipid accumulation, and uptake ability of macrophages under non-cytotoxic concentrations. Molecular data showed that these influences of gossypetin might be mediated via peroxisome proliferator-activated receptor α (PPARα)/liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) and PPARγ/scavenger receptor CD36 pathways, as demonstrated by the transfection of PPARα siRNA or PPARγ expression vector. Our data implied that gossypetin regulated the PPAR signals, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that gossypetin potentially could be developed as an anti-atherosclerotic agent. - Highlights: • The anti-atherosclerotic effect of gossypetin in vitro was examined. • Gossypetin inhibited LDL oxidation. • Gossypetin showed potential in reducing on the formation of foam cells. • Gossypetin functions against ox-LDL through PPARa activation and PPARγ depression.

  20. Insights into cyclosporine A-induced atherosclerotic risk in transplant recipients: macrophage scavenger receptor regulation.

    PubMed

    Jin, Song; Mathis, A Scott; Rosenblatt, Joseph; Minko, Tamara; Friedman, Gary S; Gioia, Kevin; Serur, David S; Knipp, Gregory T

    2004-02-27

    Clinical monitoring of organ-transplant recipients suggests that administration of cyclosporine (CsA) may increase the risk of atherosclerosis when compared with the general population. The purpose of this work is to demonstrate the utility of the in vitro Tamm-Horsfall protein (THP)-1 human monocyte cell culture model for determining drug-related atherosclerotic potential in macrophages. The effect of CsA on the mRNA expression of macrophage scavenger receptor genes including CD36, CD68, scavenger receptor (SR)-A, SR-BII, and lectin-like oxidized low-density lipoprotein receptor (LOX-1); the nuclear hormone receptors, including peroxisome-proliferator activated receptor (PPAR)gamma and liver-X-receptor (LXR)alpha; and the cholesterol efflux pump ABCA1 were investigated as markers of atherosclerotic progression. The THP-1 cells were cultured and differentiated into macrophages. The macrophages were then treated with CsA to assess gene expression. Time- (1, 2, 4, 8, and 24 hours) and dose- (concentrations [mg/L] corresponding to the trough [0.5], peak [1.25] and 4x peak [5]) dependency of CsA was assessed. The treated macrophage mRNA gene expression of CD36, CD68, and PPARgamma were up-regulated in the presence of CsA. Interestingly, SR-A, SR-BII, LOX-1, and LXRalpha expression appeared to be slightly down-regulated, and ABCA1 was relatively unchanged. Immunoblotting studies demonstrated that the protein expression of CD36 was unchanged or increased, PPARgamma was unchanged, and ABCA1 was unchanged or decreased at 4 and 8 hours. The results document CsA-induced mRNA and protein changes in receptors relevant to lipid-laden foam cell formation and demonstrate the utility of THP-1 macrophages for screening of atherosclerotic risk potential. PMID:15084924

  1. Insights into cyclosporine A-induced atherosclerotic risk in transplant recipients: macrophage scavenger receptor regulation.

    PubMed

    Jin, Song; Mathis, A Scott; Rosenblatt, Joseph; Minko, Tamara; Friedman, Gary S; Gioia, Kevin; Serur, David S; Knipp, Gregory T

    2004-02-27

    Clinical monitoring of organ-transplant recipients suggests that administration of cyclosporine (CsA) may increase the risk of atherosclerosis when compared with the general population. The purpose of this work is to demonstrate the utility of the in vitro Tamm-Horsfall protein (THP)-1 human monocyte cell culture model for determining drug-related atherosclerotic potential in macrophages. The effect of CsA on the mRNA expression of macrophage scavenger receptor genes including CD36, CD68, scavenger receptor (SR)-A, SR-BII, and lectin-like oxidized low-density lipoprotein receptor (LOX-1); the nuclear hormone receptors, including peroxisome-proliferator activated receptor (PPAR)gamma and liver-X-receptor (LXR)alpha; and the cholesterol efflux pump ABCA1 were investigated as markers of atherosclerotic progression. The THP-1 cells were cultured and differentiated into macrophages. The macrophages were then treated with CsA to assess gene expression. Time- (1, 2, 4, 8, and 24 hours) and dose- (concentrations [mg/L] corresponding to the trough [0.5], peak [1.25] and 4x peak [5]) dependency of CsA was assessed. The treated macrophage mRNA gene expression of CD36, CD68, and PPARgamma were up-regulated in the presence of CsA. Interestingly, SR-A, SR-BII, LOX-1, and LXRalpha expression appeared to be slightly down-regulated, and ABCA1 was relatively unchanged. Immunoblotting studies demonstrated that the protein expression of CD36 was unchanged or increased, PPARgamma was unchanged, and ABCA1 was unchanged or decreased at 4 and 8 hours. The results document CsA-induced mRNA and protein changes in receptors relevant to lipid-laden foam cell formation and demonstrate the utility of THP-1 macrophages for screening of atherosclerotic risk potential.

  2. Safrole-2',3'-oxide induces atherosclerotic plaque vulnerability in apolipoprotein E-knockout mice.

    PubMed

    Su, Le; Zhang, Haiyan; Zhao, Jing; Zhang, Shangli; Zhang, Yun; Zhao, Baoxiang; Miao, Junying

    2013-02-27

    Safrole-2',3'-oxide (SFO) is the major electrophilic metabolite of safrole (4-allyl-1, 2-methylenedioxybenzene), a natural plant constituent found in essential oils of numerous edible herbs and spices and in food containing these herbs, such as pesto sauce, cola beverages and bologna sausages. The effects of SFO in mammalian systems, especially the cardiovascular system, are little known. Disruption of vulnerable atherosclerotic plaques in atherosclerosis, a chronic inflammatory disease, is the main cause of cardiovascular events. In this study, we investigated SFO-induced atherosclerotic plaque vulnerability (possibility of rupture) in apolipoprotein E-knockout (apoE(-/-)) mice. Lipid area in vessel wall reached 59.8% in high dose SFO (SFO-HD) treated group, which is only 31.2% in control group. SFO treatment changed the lesion composition to an unstable phenotype, increased the number of apoptotic cells in plaque and the endothelium in plaques was damaged after SFO treatment. Furthermore, compared with control groups, the plaque endothelium level of p75(NTR) was 3-fold increased and the liver level of p75(NTR) was 17.4-fold increased by SFO-HD. Meanwhile, the serum level of KC (a functional homolog of IL-8 and the main proinflammatory alpha chemokine in mice) in apoE(-/-) mice was up to 357pg/ml in SFO-HD treated group. Thus, SFO contributes to the instability of atherosclerotic plaque in apoE(-/-) mice through activating p75(NTR) and IL-8 and cell apoptosis in plaque.

  3. Atherosclerotic neovasculature MR imaging with mixed manganese-gadolinium nanocolloids in hyperlipidemic rabbits.

    PubMed

    Wang, Kezheng; Pan, Dipanjan; Schmieder, Anne H; Senpan, Angana; Caruthers, Shelton D; Cui, Grace; Allen, John S; Zhang, Huiying; Shen, Baozhong; Lanza, Gregory M

    2015-04-01

    A high r1 relaxivity manganese-gadolinium nanocolloid (αvβ3-MnOL-Gd NC) was developed and effectively detected atherosclerotic angiogenesis in rabbits fed cholesterol-rich diets for 12 months using a clinical MRI scanner (3T). 3D mapping of neovasculature signal intensity revealed the spatial coherence and intensity of plaque angiogenic expansion, which may, with other high risk MR bioindicators, help identify high-risk patients with moderate (40% to 60%) vascular stenosis. Microscopy confirmed the predominant media and plaque distribution of fluorescent αvβ3-MnOL-Gd NC, mirroring the MR data. An expected close spatial association of αvβ3-integrin neovasculature and macrophages was noted, particularly within plaque shoulder regions. Manganese oleate bioelimination occurred via the biliary system into feces. Gd-DOTA was eliminated through the bile-fecal and renal excretion routes. αvβ3-MnOL-Gd NC offers an effective vehicle for T1w neovascular imaging in atherosclerosis. From the clinical editor: Cerebrovascular accidents are a leading cause of mortality and morbidity worldwide. The acute formation of thrombus following atherosclerotic plaque rupture has been well recognized as the etiology of stroke. The authors studied microanatomical features of vulnerable atherosclerotic plaque in this article, in an attempt to identify those with high risk of rupture. Gadolinium-manganese hybrid nanocolloid (MnOL-Gd NC) was developed as a novel contrast agent for MRI. They show that this agent is effective in providing neovascular imaging.

  4. Alternation of histone and DNA methylation in human atherosclerotic carotid plaques.

    PubMed

    Greißel, A; Culmes, M; Napieralski, R; Wagner, E; Gebhard, H; Schmitt, M; Zimmermann, A; Eckstein, H-H; Zernecke, A; Pelisek, J

    2015-08-01

    Little is known about epigenetics and its possible role in atherosclerosis. We here analysed histone and DNA methylation and the expression of corresponding methyltransferases in early and advanced human atherosclerotic carotid lesions in comparison to healthy carotid arteries. Western Blotting was performed on carotid plaques from our biobank with early (n=60) or advanced (n=60) stages of atherosclerosis and healthy carotid arteries (n=12) to analyse di-methylation patterns of histone H3 at positions K4, K9 and K27. In atherosclerotic lesions, di-methylation of H3K4 was unaltered and that of H3K9 and H3K27 significantly decreased compared to control arteries. Immunohistochemistry revealed an increased appearance of di-methylated H3K4 in smooth muscle cells (SMCs), a decreased expression of di-methylated H3K9 in SMCs and inflammatory cells, and reduced di-methylated H3K27 in inflammatory cells in advanced versus early atherosclerosis. Expression of corresponding histone methyltransferases MLL2 and G9a was increased in advanced versus early atherosclerosis. Genomic DNA hypomethylation, as determined by PCR for methylated LINE1 and SAT-alpha, was observed in early and advanced plaques compared to control arteries and in cell-free serum of patients with high-grade carotid stenosis compared to healthy volunteers. In contrast, no differences in DNA methylation were observed in blood cells. Expression of DNA-methyltransferase DNMT1 was reduced in atherosclerotic plaques versus controls, DNMT3A was undetectable, and DNMT3B not altered. DNA-demethylase TET1 was increased in atherosclerosisc plaques. The extent of histone and DNA methylation and expression of some corresponding methyltransferases are significantly altered in atherosclerosis, suggesting a possible contribution of epigenetics in disease development. PMID:25993995

  5. Recombinant Human Elastase Alters the Compliance of Atherosclerotic Tibial Arteries After Ex Vivo Angioplasty

    PubMed Central

    Bingham, Karen; Moss, Emma; Gottlieb, Daniel P.; Wong, Marco D.; Bland, Kimberly S.; Franano, F. Nicholas

    2016-01-01

    Purpose: This study was designed to determine whether vonapanitase (formerly PRT-201), a recombinant human elastase, treatment can fragment the protein elastin in elastic fibers and cause dilation of atherosclerotic human peripheral arteries subjected to ex vivo balloon angioplasty. Materials and Methods: Seven patients undergoing lower limb amputation for peripheral artery disease or who died and donated their bodies to science donated 11 tibial arteries (5 anterior, 6 posterior) for this study. All arteries were atherosclerotic by visual inspection. The arteries underwent ex vivo balloon angioplasty and thereafter were cut into rings and studied on wire myographs where the rings were stretched and tension was recorded. After treatment with vonapanitase 2 mg/mL or vehicle control, myography was repeated and the rings were then subject to elastin content measurement using a desmosine radioimmunoassay and elastic fiber visualization by histology. The wire myography data were used to derive compliance, stress-strain, and incremental elastic modulus curves. Results: Vonapanitase treatment reduced elastin (desmosine) content by 60% and decreased elastic fiber histologic staining. Vonapanitase-treated rings experienced less tension at any level of stretch and as a result had shifts in the compliance and stress-strain curves relative to vehicle-treated rings. Vonapanitase treatment did not alter the incremental elastic modulus curve. Conclusions: Vonapanitase treatment of atherosclerotic human peripheral arteries after ex vivo balloon angioplasty fragmented elastin in elastic fibers, decreased tension in the rings at any level of stretch, and altered the compliance and stress-strain curves in a manner predicting arterial dilation in vivo. Based on this result, local treatment of balloon angioplasty sites may increase blood vessel diameter and thereby improve the success of balloon angioplasty in peripheral artery disease. PMID:26745001

  6. Vacuum Brazing of Accelerator Components

    NASA Astrophysics Data System (ADS)

    Singh, Rajvir; Pant, K. K.; Lal, Shankar; Yadav, D. P.; Garg, S. R.; Raghuvanshi, V. K.; Mundra, G.

    2012-11-01

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  7. Bifurcation analysis of a model for atherosclerotic plaque evolution

    NASA Astrophysics Data System (ADS)

    Bulelzai, M. A. K.; Dubbeldam, J. L. A.; Meijer, H. G. E.

    2014-06-01

    We analyze two ordinary differential equation (ODE) models for atherosclerosis. The ODE models describe long time evolution of plaques in arteries. We show how the dynamics of the first atherosclerosis model (model A) can be understood using codimension-two bifurcation analysis. The Low-Density Lipoprotein (LDL) intake parameter (d) is the first control parameter and the second control parameter is either taken to be the conversion rate of macrophages (b) or the wall shear stress (σ). Our analysis reveals that in both cases a Bogdanov-Takens (BT) point acts as an organizing center. The bifurcation diagrams are calculated partly analytically and to a large extent numerically using AUTO07 and MATCONT. The bifurcation curves show that the concentration of LDL in the plaque as well as the monocyte and the macrophage concentrations exhibit oscillations for a certain range of values of the control parameters. Moreover, we find that there are threshold values for both the cholesterol intake rate dcrit and the conversion rate of the macrophages bcrit, which depend on the values of other parameters, above which the plaque volume increases with time. It is found that larger conversion rates of macrophages lower the threshold value of cholesterol intake and vice versa. We further argue that the dynamics for model A can still be discerned in the second model (model B) in which the slow evolution of the radius of the artery is coupled self-consistently to changes in the plaque volume. The very slow evolution of the radius of the artery compared to the other processes makes it possible to use a slow manifold approximation to study the dynamics in this case. We find that in this case the model predicts that the concentrations of the plaque constituents may go through a period of oscillations before the radius of the artery will start to decrease. These oscillations hence act as a precursor for the reduction of the artery radius by plaque growth.

  8. Capsular warning syndrome and crescendo lacunar strokes after atherosclerotic stenosis of the recurrent artery of Heubner.

    PubMed

    Cohen, José E; Rabinstein, Alejandro; Gomori, John M; Leker, Ronen R

    2012-12-01

    The stereotype of repetitive transient cerebral ischemia causing unilateral motor, sensory, or sensorimotor deficits that simultaneously affect the face, arm, and leg, clinically localized to the internal capsule, fits with the description of capsular warning syndrome (CWS). A high proportion of individuals with these symptoms develop subsequent capsular stroke, despite various proposed preventative measures. It has been postulated that the mechanism for such strokes is that of small-vessel single-penetrator disease. We present a patient with repetitive CWS intermingled with crescendo capsular strokes secondary to recurrent artery of Heubner disease. This report causally links CWS-crescendo lacunar strokes and Heubner artery atherosclerotic disease (intracranial branch atheromatous disease).

  9. Mesenchymal Stem Cells Stabilize Atherosclerotic Vulnerable Plaque by Anti-Inflammatory Properties

    PubMed Central

    Wang, Shuang-shuang; Hu, Si-wang; Zhang, Qing-hua; Xia, Ai-xiang

    2015-01-01

    Background and objectives Formation and progression of atherosclerotic vulnerable plaque (VP) is the primary cause of many cardio-cerebrovascular diseases such as acute coronary syndrome and stroke. It has been reported that bone marrow mesenchymal stem cells (MSC) exhibit protective effects against many kinds of diseases including myocardial infarction. Here, we examined the effects of intravenous MSC infusion on a VP model and provide novel evidence of its influence as a therapy in this animal disease model. Subjects and methods Thirty healthy male New Zealand white rabbits were randomly divided into a MSC, VP or stable plaque (SP) group (n = 10/group) and received high fat diet and cold-induced common carotid artery intimal injury with liquid nitrogen to form atherosclerotic plaques. Serum hs-CRP, TNF-α, IL-6 and IL-10 levels were measured by ELISA at 1, 2, 3, 7, 14, 21 and 28 days after MSC transplantation. The animals were sacrificed at 4 weeks after MSC transplantation. Lesions in the right common carotid were observed using H&E and Masson staining, and the fibrous cap/lipid core ratio of atherosclerotic plaques were calculated. The expression of nuclear factor κB (NF-κB) and matrix metalloproteinase 1, 2, 9 (MMP-1,2,9) in the plaque were detected using immunohistochemistry, and apoptotic cells in the plaques were detected by TUNEL. In addition, the level of TNF-α stimulated gene/protein 6 (TSG-6) mRNA and protein were measured by quantitative Real-Time PCR and Western blotting, respectively. Results Two rabbits in the VP group died of lung infection and cerebral infarction respectively at 1 week after plaque injury by liquid nitrogen. Both H&E and Masson staining revealed that the plaques from the SP and MSC groups had more stable morphological structure and a larger fibrous cap/lipid core ratio than the VP group. Serum hs-CRP, TNF-α and IL-6 were significantly down-regulated, whereas IL-10 was significantly up-regulated in the MSC group compared with

  10. Atherosclerotic adult Moya-Moya disease in a patient with hyperhomocysteinaemia.

    PubMed

    Cerrato, P; Grasso, M; Lentini, A; Destefanis, E; Bosco, G; Caprioli, M; Bradac, G B; Bergui, M

    2007-03-01

    Moya-Moya is a rare cerebrovascular occlusive disease characterized by bilateral stenosis or occlusion at the terminal portion of the internal carotid artery and abnormal vascular network at the base of the brain, named "moya-moya". In children, Moya-Moya disease usually presents with ischemic cerebrovascular events, mainly TIA or lacunar stroke, leading to mental deterioration. In adults, especially in females, it presents with intracranial haemorrhages. We describe the case of an adult patient with an atherosclerotic Moya-Moya disease which presented with a cerebral borderzone infarction.

  11. Electron Acceleration by Transient Ion Foreshock Phenomena

    NASA Astrophysics Data System (ADS)

    Wilson, L. B., III; Turner, D. L.

    2015-12-01

    Particle acceleration is a topic of considerable interest in space, laboratory, and astrophysical plasmas as it is a fundamental physical process to all areas of physics. Recent THEMIS [e.g., Turner et al., 2014] and Wind [e.g., Wilson et al., 2013] observations have found evidence for strong particle acceleration at macro- and meso-scale structures and/or pulsations called transient ion foreshock phenomena (TIFP). Ion acceleration has been extensively studied, but electron acceleration has received less attention. Electron acceleration can arise from fundamentally different processes than those affecting ions due to differences in their gyroradii. Electron acceleration is ubiquitous, occurring in the solar corona (e.g., solar flares), magnetic reconnection, at shocks, astrophysical plasmas, etc. We present new results analyzing the dependencies of electron acceleration on the properties of TIFP observed by the THEMIS spacecraft.

  12. Dual-modality fiber-based OCT-TPL imaging system for simultaneous microstructural and molecular analysis of atherosclerotic plaques

    PubMed Central

    Wang, Tianyi; McElroy, Austin; Halaney, David; Vela, Deborah; Fung, Edmund; Hossain, Shafat; Phipps, Jennifer; Wang, Bingqing; Yin, Biwei; Feldman, Marc D.; Milner, Thomas E.

    2015-01-01

    New optical imaging techniques that provide contrast to study both the anatomy and composition of atherosclerotic plaques can be utilized to better understand the formation, progression and clinical complications of human coronary artery disease. We present a dual-modality fiber-based optical imaging system for simultaneous microstructural and molecular analysis of atherosclerotic plaques that combines optical coherence tomography (OCT) and two-photon luminescence (TPL) imaging. Experimental results from ex vivo human coronary arteries show that OCT and TPL optical contrast in recorded OCT-TPL images is complimentary and in agreement with histological analysis. Molecular composition (e.g., lipid and oxidized-LDL) detected by TPL imaging can be overlaid onto plaque microstructure depicted by OCT, providing new opportunities for atherosclerotic plaque identification and characterization. PMID:26137371

  13. Acceleration during magnetic reconnection

    SciTech Connect

    Beresnyak, Andrey; Li, Hui

    2015-07-16

    The presentation begins with colorful depictions of solar x-ray flares and references to pulsar phenomena. Plasma reconnection is complex, could be x-point dominated or turbulent, field lines could break due to either resistivity or non-ideal effects, such as electron pressure anisotropy. Electron acceleration is sometimes observed, and sometimes not. One way to study this complex problem is to have many examples of the process (reconnection) and compare them; the other way is to simplify and come to something robust. Ideal MHD (E=0) turbulence driven by magnetic energy is assumed, and the first-order acceleration is sought. It is found that dissipation in big (length >100 ion skin depths) current sheets is universal and independent on microscopic resistivity and the mean imposed field; particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. One example of such flow is spontaneous reconnection. This explains hot electrons with a power-law tail in solar flares, as well as ultrashort time variability in some astrophysical sources.

  14. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Roberts, W. T.

    1985-01-01

    The space experiments with particle accelerators (SEPAC) instruments consist of an electron accelerator, a plasma accelerator, a neutral gas (N2) release device, particle and field diagnostic instruments, and a low light level television system. These instruments are used to accomplish multiple experiments: to study beam particle interactions and other plasma processes; as probes to investigate magnetospheric processes; and as perturbation devices to study energy coupling mechanisms in the magnetosphere, ionosphere, and upper atmosphere.

  15. Thermal compression and molding of atherosclerotic vascular tissue with use of radiofrequency energy: implications for radiofrequency balloon angioplasty.

    PubMed

    Lee, B I; Becker, G J; Waller, B F; Barry, K J; Connolly, R J; Kaplan, J; Shapiro, A R; Nardella, P C

    1989-04-01

    The combined delivery of pressure and thermal energy may effectively remodel intraluminal atherosclerotic plaque and fuse intimal tears. To test these hypotheses with use of a non-laser thermal energy source, radiofrequency energy was delivered to postmortem human atherosclerotic vessels from a metal "hot-tip" catheter, block-mounted bipolar electrodes and from a prototype radiofrequency balloon catheter. Sixty-two radiofrequency doses delivered from a metal electrode tip produced dose-dependent ablation of atherosclerotic plaque, ranging from clean and shallow craters with histologic evidence of thermal compression at doses less than 40 J to tissue charring and vaporization at higher (greater than 80 J) doses. Lesion dimensions ranged between 3.14 and 3.79 mm in diameter and 0.20 and 0.47 mm in depth. Tissue perforation was not observed. To test the potential for radiofrequency fusion of intimal tears, 5 atm of pressure and 200 J radiofrequency energy were delivered from block-mounted bipolar electrodes to 48 segments of human atherosclerotic aorta, which had been manually separated into intima-media and media-adventitial layers. Significantly stronger tissue fusion resulted (28.5 +/- 3.3 g) with radiofrequency compared with that with pressure alone (4.8 +/- 0.26 g; p less than 0.0001). A prototype radiofrequency balloon catheter was used to deliver 3 atm of balloon pressure with or without 200 J radiofrequency energy to 20 postmortem human atherosclerotic arterial segments. In 10 of 10 radiofrequency-treated vessels, thermal "molding" of both normal and atherosclerotic vessel wall segments resulted with increased luminal diameter and histologic evidence of medial myocyte damage.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Thermal compression and molding of atherosclerotic vascular tissue with use of radiofrequency energy: implications for radiofrequency balloon angioplasty

    SciTech Connect

    Lee, B.I.; Becker, G.J.; Waller, B.F.; Barry, K.J.; Connolly, R.J.; Kaplan, J.; Shapiro, A.R.; Nardella, P.C.

    1989-04-01

    The combined delivery of pressure and thermal energy may effectively remodel intraluminal atherosclerotic plaque and fuse intimal tears. To test these hypotheses with use of a non-laser thermal energy source, radiofrequency energy was delivered to postmortem human atherosclerotic vessels from a metal hot-tip catheter, block-mounted bipolar electrodes and from a prototype radiofrequency balloon catheter. Sixty-two radiofrequency doses delivered from a metal electrode tip produced dose-dependent ablation of atherosclerotic plaque, ranging from clean and shallow craters with histologic evidence of thermal compression at doses less than 40 J to tissue charring and vaporization at higher (greater than 80 J) doses. Lesion dimensions ranged between 3.14 and 3.79 mm in diameter and 0.20 and 0.47 mm in depth. Tissue perforation was not observed. To test the potential for radiofrequency fusion of intimal tears, 5 atm of pressure and 200 J radiofrequency energy were delivered from block-mounted bipolar electrodes to 48 segments of human atherosclerotic aorta, which had been manually separated into intima-media and media-adventitial layers. Significantly stronger tissue fusion resulted (28.5 +/- 3.3 g) with radiofrequency compared with that with pressure alone (4.8 +/- 0.26 g; p less than 0.0001). A prototype radiofrequency balloon catheter was used to deliver 3 atm of balloon pressure with or without 200 J radiofrequency energy to 20 postmortem human atherosclerotic arterial segments. In 10 of 10 radiofrequency-treated vessels, thermal molding of both normal and atherosclerotic vessel wall segments resulted with increased luminal diameter and histologic evidence of medial myocyte damage.

  17. Selective removal of cholesterol ester in atherosclerotic plaque using nanosecond pulsed laser at 5.75 μm

    NASA Astrophysics Data System (ADS)

    Ishii, K.; Tsukimoto, H.; Hazama, H.; Awazu, K.

    2008-02-01

    Laser angioplasty, for example XeCl excimer laser angioplasty, has gained more attention in addition to conventional methods of surgical and interventional treatment of atherosclerotic diseases such as bypass operation and balloon dilatation. Low degrees of thermal damage after ablation of atherosclerotic lesions have been achieved by XeCl excimer laser at 308 nm. However, in most cases, laser ablation is not selective and normal arterial wall is also damaged. To avoid complications such as severe dissections or perforation of the arterial wall in an angioplasty, a laser light source with high ablation efficiency but low arterial wall injury is desirable. At atherosclerotic lesions, cholesterol accumulates on the tunica intima by establishing an ester bond with fatty acids such as oleic acid, and thus cholesterol ester is the main component of atherosclerotic plaques. Mid-infrared pulsed laser at 5.75 μm is selectively well absorbed in C=O stretching vibration mode of ester bonds. The purpose of this study is to determine the effectiveness of nanosecond pulsed laser at 5.75 μm irradiation of cholesterol ester in atherosclerotic plaques. In this study, we used a mid-infrared tunable solid-state laser which is operated by difference frequency generation method, with a wavelength of 5.75 μm, a pulse width of 5 nsec and a pulse duration of 10 Hz. It was confirmed that non-invasive interaction to normal thoracic aortas could be induce by the parameters, the wavelength of 5.75 μm, the average power densities of 35 W/cm2 and the irradiation time under 10 sec. This study shows that nanosecond pulsed laser irradiations at 5.75 μm provide an alternative laser light source as an effectively cutting, less traumatic tool for removal of atherosclerotic plaque.

  18. Biophysical regulation of Chlamydia pneumoniae-infected monocyte recruitment to atherosclerotic foci

    PubMed Central

    Evani, Shankar J.; Ramasubramanian, Anand K.

    2016-01-01

    Chlamydia pneumoniae infection is implicated in atherosclerosis although the contributory mechanisms are poorly understood. We hypothesize that C. pneumoniae infection favors the recruitment of monocytes to atherosclerotic foci by altering monocyte biophysics. Primary, fresh human monocytes were infected with C. pneumoniae for 8 h, and the interactions between monocytes and E-selectin or aortic endothelium under flow were characterized by video microscopy and image analysis. The distribution of membrane lipid rafts and adhesion receptors were analyzed by imaging flow cytometry. Infected cells rolled on E-selectin and endothelial surfaces, and this rolling was slower, steady and uniform compared to uninfected cells. Infection decreases cholesterol levels, increases membrane fluidity, disrupts lipid rafts, and redistributes CD44, which is the primary mediator of rolling interactions. Together, these changes translate to higher firm adhesion of infected monocytes on endothelium, which is enhanced in the presence of LDL. Uninfected monocytes treated with LDL or left untreated were used as baseline control. Our results demonstrate that the membrane biophysical changes due to infection and hyperlipidemia are one of the key mechanisms by which C. pneumoniae can exacerbate atherosclerotic pathology. These findings provide a framework to characterize the role of ‘infectious burden’ in the development and progression of atherosclerosis. PMID:26785849

  19. Lipid lowering by hydroalcoholic extracts of Amaranthus Caudatus L. induces regression of rabbits atherosclerotic lesions

    PubMed Central

    2011-01-01

    Background The antihypercholesterolemic and antiatherogenic effect of hydroalcoholic extracts of Amaranthus caudatus L(A. caudatus). on regression of atherosclerosis in experimental rabbits maintained on a high cholesterol diet. Methods Twenty five rabbits were randomly divided into five groups of five each and treated 75 days as follows: Group I: normal diet(ND), Group II: Hypercholesterolemic diet (HCD) for 45 days; Group III: Hypercholesterolemic diet (HCD) for 75 days, Group IV and V: HCD for 45 days and then normal diet and normal diet + A. caudatus(150 mg·kg day) respectively for an additional 30 days(regression period). Blood samples were collected before (0 time) and after 45 days and 75 days of experimental diets for measurement of biochemical factors. The aortas were removed at the end of the study for assessment of atherosclerotic plaques. Results In regression period dietary use of A. caudatus in group V significantly decreased total cholesterol, LDL-cholesterol, malondialdehyde, C-reactive protein while apolipoproteinA and HDL- cholesterol was significantly increased compared to group IV. The atherosclerotic area was significantly decreased in group V. Whereas, the animals that in regression period received only normal diet showed no regression but rather progression of atherosclerosis. Conclusion These results thus suggest that hydroalcoholic extracts of A. caudatus can reduce risk factors and cause regression of fatty lesons in aorta. PMID:21619685

  20. 13C MAS NMR studies of crystalline cholesterol and lipid mixtures modeling atherosclerotic plaques.

    PubMed Central

    Guo, W; Hamilton, J A

    1996-01-01

    Cholesterol and cholesteryl esters are the predominant lipids of atherosclerotic plaques. To provide fundamental data for the quantitative study of plaque lipids in situ, crystalline cholesterol (CHOL) and CHOL/cholesteryl ester (CE) mixtures with other lipids were studied by solid-state nuclear magnetic resonance with magic-angle-sample spinning. Highly distinctive spectra for three different crystalline structures of CHOL were obtained. When CHOL crystals were mixed with isotropic CE oil, solubilized CHOL (approximately 13 mol % CHOL) was detected by characteristic resonances such as C5, C6, and C3; the excess crystalline CHOL (either anhydrous or monohydrate) remained in its original crystalline structure, without being affected by the coexisting CE. By use of 13C-enriched CHOL, the solubility of CHOL in the CE liquid-crystalline phase (approximately 8 mol %) was measured. When phosphatidylcholine was hydrated in presence of CHOL and CE, magic-angle-sampling nuclear magnetic resonance revealed liquid-crystalline CHOL/phosphatidylcholine multilayers with approximately an equal molar ratio of CHOL/phosphatidylcholine. Excess CHOL existed in the monohydrate crystalline form, and CE in separate oil or crystalline phases, depending on the temperature. The magic-angle-sampling nuclear magnetic resonance protocol for identifying different lipid phases was applied to intact (ex vivo) atherosclerotic plaques of cholesterol-fed rabbits. Liquid, liquid-crystalline, and solid phases of CE were characterized. Images FIGURE 2 PMID:8913623

  1. Lipofundin-Induced Hyperlipidemia Promotes Oxidative Stress and Atherosclerotic Lesions in New Zealand White Rabbits

    PubMed Central

    Delgado Roche, Livan; Acosta Medina, Emilio; Fraga Pérez, Ángela; Bécquer Viart, María A.; Soto López, Yosdel; Falcón Cama, Viviana; Vázquez López, Ana M.; Martínez-Sánchez, Gregorio; Fernández-Sánchez, Eduardo

    2012-01-01

    Atherosclerosis represents a major cause of death in the world. It is known that Lipofundin 20% induces atherosclerotic lesions in rabbits, but its effects on serum lipids behaviour and redox environment have not been addressed. In this study, New Zealand rabbits were treated with 2 mL/kg of Lipofundin for 8 days. Then, redox biomarkers and serum lipids were determined spectrophotometrically. On the other hand, the development of atherosclerotic lesions was confirmed by eosin/hematoxylin staining and electron microscopy. At the end of the experiment, total cholesterol, triglycerides, cholesterol-LDL, and cholesterol-HDL levels were significantly increased. Also, a high index of biomolecules damage, a disruption of both enzymatic and nonenzymatic defenses, and a reduction of nitric oxide were observed. Our data demonstrated that Lipofundin 20% induces hyperlipidemia, which promotes an oxidative stress state. Due to the importance of these phenomena as risk factors for atherogenesis, we suggest that Lipofundin induces atherosclerosis mainly through these mechanisms. PMID:21977325

  2. Ultrafast optical-ultrasonic system and miniaturized catheter for imaging and characterizing atherosclerotic plaques in vivo

    PubMed Central

    Li, Jiawen; Ma, Teng; Mohar, Dilbahar; Steward, Earl; Yu, Mingyue; Piao, Zhonglie; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Patel, Pranav M.; Chen, Zhongping

    2015-01-01

    Atherosclerotic coronary artery disease (CAD) is the number one cause of death worldwide. The majority of CAD-induced deaths are due to the rupture of vulnerable plaques. Accurate assessment of plaques is crucial to optimize treatment and prevent death in patients with CAD. Current diagnostic techniques are often limited by either spatial resolution or penetration depth. Several studies have proved that the combined use of optical and ultrasonic imaging techniques increase diagnostic accuracy of vulnerable plaques. Here, we introduce an ultrafast optical-ultrasonic dual-modality imaging system and flexible miniaturized catheter, which enables the translation of this technology into clinical practice. This system can perform simultaneous optical coherence tomography (OCT)-intravascular ultrasound (IVUS) imaging at 72 frames per second safely in vivo, i.e., visualizing a 72 mm-long artery in 4 seconds. Results obtained in atherosclerotic rabbits in vivo and human coronary artery segments show that this ultrafast technique can rapidly provide volumetric mapping of plaques and clearly identify vulnerable plaques. By providing ultrafast imaging of arteries with high resolution and deep penetration depth simultaneously, this hybrid IVUS-OCT technology opens new and safe opportunities to evaluate in real-time the risk posed by plaques, detect vulnerable plaques, and optimize treatment decisions. PMID:26678300

  3. Automatic segmentation and plaque characterization in atherosclerotic carotid artery MR images.

    PubMed

    Adame, I M; van der Geest, R J; Wasserman, B A; Mohamed, M A; Reiber, J H C; Lelieveldt, B P F

    2004-04-01

    In vivo MRI provides a means to non-invasively image and assess the morphological features of atherosclerotic carotid arteries. To assess quantitatively the degree of vulnerability and the type of plaque, the contours of the lumen, outer boundary of the vessel wall and plaque components, need to be traced. Currently this is done manually, which is time-consuming and sensitive to inter- and intra-observer variability. The goal of this work was to develop an automated contour detection technique for tracing the lumen, outer boundary and plaque contours in carotid MR short-axis black-blood images. Seventeen patients with carotid atherosclerosis were imaged using high-resolution in vivo MRI, generating a total of 50 PD- and T1-weighted MR images. These images were automatically segmented using the algorithm presented in this work, which combines model-based segmentation and fuzzy clustering to detect the vessel wall, lumen and lipid core boundaries. The results demonstrate excellent correspondence between automatic and manual area measurements for lumen (r = 0.92) and outer (r = 0.91), and acceptable correspondence for fibrous cap thickness (r = 0.71). Though further optimization is required, our algorithm is a powerful tool for automatic detection of lumen and outer boundaries, and characterization of plaque in atherosclerotic vessels. PMID:15029508

  4. Classification of aortic atherosclerotic lesions with time-resolved fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Maarek, Jean-Michel I.; Marcu, Laura; Grundfest, Warren S.; Fishbein, Michael C.

    1999-07-01

    In this study, we examine the possibility of differentiating between classes of atherosclerotic lesions based on time- resolved fluorescence spectroscopy and we compare the performance of classification schemes that use either the time-resolved spectra or only the intensity spectra. Transient fluorescence emissions induced by pulsed nitrogen laser excitation was measured on 87 excised samples of human aorta. The samples were classified histologically using the AHA classification Predictor variables derived from the time-resolved spectra included the spectral intensities at 360-510 nm and parameters of a biexponential fit of the fluorescence impulse response function. Stepwise discriminant analysis using these predict variables showed that a few predictor variables sufficed to correctly classify 89 percent of the samples. Excluding the time- dependent decay and using only the spectral intensities, the percentage of correctly classified cases was significantly lower: 51 percent. These results establish that time- resolved fluorescence spectroscopy markedly improved on the performance of steady-state fluorescence spectroscopy for fine classification of atherosclerotic lesions.

  5. Biophysical regulation of Chlamydia pneumoniae-infected monocyte recruitment to atherosclerotic foci

    NASA Astrophysics Data System (ADS)

    Evani, Shankar J.; Ramasubramanian, Anand K.

    2016-01-01

    Chlamydia pneumoniae infection is implicated in atherosclerosis although the contributory mechanisms are poorly understood. We hypothesize that C. pneumoniae infection favors the recruitment of monocytes to atherosclerotic foci by altering monocyte biophysics. Primary, fresh human monocytes were infected with C. pneumoniae for 8 h, and the interactions between monocytes and E-selectin or aortic endothelium under flow were characterized by video microscopy and image analysis. The distribution of membrane lipid rafts and adhesion receptors were analyzed by imaging flow cytometry. Infected cells rolled on E-selectin and endothelial surfaces, and this rolling was slower, steady and uniform compared to uninfected cells. Infection decreases cholesterol levels, increases membrane fluidity, disrupts lipid rafts, and redistributes CD44, which is the primary mediator of rolling interactions. Together, these changes translate to higher firm adhesion of infected monocytes on endothelium, which is enhanced in the presence of LDL. Uninfected monocytes treated with LDL or left untreated were used as baseline control. Our results demonstrate that the membrane biophysical changes due to infection and hyperlipidemia are one of the key mechanisms by which C. pneumoniae can exacerbate atherosclerotic pathology. These findings provide a framework to characterize the role of ‘infectious burden’ in the development and progression of atherosclerosis.

  6. Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries

    NASA Astrophysics Data System (ADS)

    McArdle, Sara; Chodaczek, Grzegorz; Ray, Nilanjan; Ley, Klaus

    2015-02-01

    Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe-/-Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP+ macrophages "dancing on the spot" and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells.

  7. Characterizing white matter health and organization in atherosclerotic vascular disease: a diffusion tensor imaging study.

    PubMed

    Rowe Bijanki, Kelly; Arndt, Stephan; Magnotta, Vincent A; Nopoulos, Peg; Paradiso, Sergio; Matsui, Joy T; Johnson, Hans J; Moser, David J

    2013-12-30

    Atherosclerotic vascular disease (AVD) is endemic to the developed world, with known negative outcomes for cognition and brain health. The effects of AVD on the white matter fibers of the brain have not yet been studied using diffusion tensor imaging (DTI). This study examined differences in fractional anisotropy (FA) between AVD and healthy comparison (HC) participants, and described the regional patterns of FA in each group. AVD participants were hypothesized to have lower FA than HC participants, indicating abnormalities in white matter health or organization. 1.5 T diffusion tensor imaging was performed in 35 AVD and 22 HC participants. Mean FA measures were calculated for the white matter of the whole brain, as well for individual lobes. Globally and in every brain region measured except the temporal lobes, there were significant effects of group where AVD participants had lower FA values than their HC counterparts. Group differences in FA remained significant when controlled for white matter hyperintensity (WMH) volume, suggesting that FA detects white matter abnormality above and beyond what is measurable using the older WMH technique. These findings suggest a likely neural substrate underlying the changes in cognition and mood reported in atherosclerotic vascular disease patients.

  8. Endothelial to mesenchymal transition is common in atherosclerotic lesions and is associated with plaque instability.

    PubMed

    Evrard, Solene M; Lecce, Laura; Michelis, Katherine C; Nomura-Kitabayashi, Aya; Pandey, Gaurav; Purushothaman, K-Raman; d'Escamard, Valentina; Li, Jennifer R; Hadri, Lahouaria; Fujitani, Kenji; Moreno, Pedro R; Benard, Ludovic; Rimmele, Pauline; Cohain, Ariella; Mecham, Brigham; Randolph, Gwendalyn J; Nabel, Elizabeth G; Hajjar, Roger; Fuster, Valentin; Boehm, Manfred; Kovacic, Jason C

    2016-06-24

    Endothelial to mesenchymal transition (EndMT) plays a major role during development, and also contributes to several adult cardiovascular diseases. Importantly, mesenchymal cells including fibroblasts are prominent in atherosclerosis, with key functions including regulation of: inflammation, matrix and collagen production, and plaque structural integrity. However, little is known about the origins of atherosclerosis-associated fibroblasts. Here we show using endothelial-specific lineage-tracking that EndMT-derived fibroblast-like cells are common in atherosclerotic lesions, with EndMT-derived cells expressing a range of fibroblast-specific markers. In vitro modelling confirms that EndMT is driven by TGF-β signalling, oxidative stress and hypoxia; all hallmarks of atherosclerosis. 'Transitioning' cells are readily detected in human plaques co-expressing endothelial and fibroblast/mesenchymal proteins, indicative of EndMT. The extent of EndMT correlates with an unstable plaque phenotype, which appears driven by altered collagen-MMP production in EndMT-derived cells. We conclude that EndMT contributes to atherosclerotic patho-biology and is associated with complex plaques that may be related to clinical events.

  9. Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries

    PubMed Central

    McArdle, Sara; Chodaczek, Grzegorz; Ray, Nilanjan; Ley, Klaus

    2015-01-01

    Abstract. Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe−/−Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP+ macrophages “dancing on the spot” and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells. PMID:25710308

  10. Endothelial lipase is highly expressed in macrophages in advanced human atherosclerotic lesions.

    PubMed

    Bartels, Emil D; Nielsen, John E; Lindegaard, Marie L S; Hulten, Lillemor M; Schroeder, Torben V; Nielsen, Lars B

    2007-12-01

    Endothelial lipase (EL) is expressed in endothelial cells, and affects plasma lipoprotein metabolism by hydrolyzing phospholipids in HDL. To determine the cellular expression of EL mRNA and protein in human atherosclerotic lesions, we performed in situ hybridization and immunohistochemical studies on sections of carotid endarterectomy specimens from patients with symptomatic cerebrovascular disease. In each of eight patients, EL mRNA and/or protein were seen in areas between the necrotic core and the fibrotic cap where they colocalized with LPL and macrophage-specific CD68. Moreover, there was a positive association between the expression of EL mRNA and CD68 mRNA in plaques from 26 patients. The impact of differentiation from monocytes into macrophages, and subsequently foam cells (by incubation with acetylated LDL) on expression was studied using THP-1 monocytes and primary human monocytes. EL mRNA expression increased markedly when either type of monocytes was differentiated into macrophages. Upon further differentiation into foam cells EL mRNA decreased whereas protein levels remained high compared to monocytes. In conclusion, macrophages in advanced human atherosclerotic lesions display high levels of EL expression, and the level of EL expression varies greatly during transformation of blood monocytes into foam cells.

  11. Hematopoietic Fas deficiency does not affect experimental atherosclerotic lesion formation despite inducing a proatherogenic state.

    PubMed

    de Claro, R Angelo; Zhu, Xiaodong; Tang, Jingjing; Morgan-Stevenson, Vicki; Schwartz, Barbara R; Iwata, Akiko; Liles, W Conrad; Raines, Elaine W; Harlan, John M

    2011-06-01

    The Fas death receptor (CD95) is expressed on macrophages, smooth muscle cells, and T cells within atherosclerotic lesions. Given the dual roles of Fas in both apoptotic and nonapoptotic signaling, the aim of the present study was to test the effect of hematopoietic Fas deficiency on experimental atherosclerosis in low-density lipoprotein receptor-null mice (Ldlr(-/-)). Bone marrow from Fas(-/-) mice was used to reconstitute irradiated Ldlr(-/-) mice as a model for atherosclerosis. After 16 weeks on an 0.5% cholesterol diet, no differences were noted in brachiocephalic artery lesion size, cellularity, or vessel wall apoptosis. However, Ldlr(-/-) mice reconstituted with Fas(-/-) hematopoietic cells had elevated hyperlipidemia [80% increase, relative to wild-type (WT) controls; P < 0.001] and showed marked elevation of plasma levels of CXCL1/KC, CCL2/MCP-1, IL-6, IL-10, IL-12 subunit p70, and soluble Fas ligand (P < 0.01), as well as systemic microvascular inflammation. It was not possible to assess later stages of atherosclerosis because of increased mortality in Fas(-/-) bone marrow recipients. Our data indicate that hematopoietic Fas deficiency does not affect early atherosclerotic lesion development in Ldlr(-/-) mice.

  12. Clopidogrel plus Aspirin for Symptomatic Intracranial Atherosclerotic Stenosis: A Pilot Study

    PubMed Central

    Kass-Hout, Tareq; Winningham, Melanie; Kass-Hout, Omar; Henriquez, Laura; Tong, Frank; Dion, Jacques; Cawley, Michael; Belagaje, Samir; Frankel, Michael; Anderson, Aaron; Nahab, Fadi

    2016-01-01

    Background and Purpose There are limited data on the optimal duration of dual antiplatelet therapy for secondary stroke prevention in patients with symptomatic intracranial atherosclerotic disease. Methods Consecutive patients presenting with high-grade (70–99%) symptomatic intracranial stenosis from January 1, 2011, to December 31, 2013, and evaluated within 30 days of the index event were eligible for this analysis. All patients underwent treatment with aspirin plus clopidogrel for a target duration of 12 months along with aggressive medical management based on the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) protocol; all patients were given gastrointestinal prophylaxis for the duration of their aspirin and clopidogrel treatment. Clinical and safety outcomes of our cohort were compared with the medical arm of the SAMMPRIS trial cohort (n = 227). Results Our cohort included 25 patients that met the inclusion criteria. Achievement of blood pressure and LDL cholesterol targets were similar between our cohort and the SAMMPRIS cohort. At 1 year, the rates of stroke, myocardial infarction or vascular death were 0% in our cohort and 16% in the SAMMPRIS cohort (p = 0.03). At 1 year, major bleeding rates were similar between our cohort and the SAMMPRIS cohort (4 vs. 2.2%, p = 1.0). Conclusion A prolonged course of dual antiplatelet therapy for symptomatic intracranial atherosclerotic disease may be associated with less vascular events with no increase in hemorrhagic complications. PMID:27781044

  13. Characterization of atherosclerotic arterial tissue using multimodal non-linear optical microscopy

    NASA Astrophysics Data System (ADS)

    Cicchi, Riccardo; Matthäus, Christian; Meyer, Tobias; Lattermann, Annika; Dietzek, Benjamin; Brehm, Bernhard R.; Popp, Jürgen; Pavone, Francesco S.

    2013-06-01

    Atherosclerosis is among the most widespread cardiovascular diseases and one of the leading cause of death in the Western World. Characterization of arterial tissue in atherosclerotic condition is extremely interesting from the diagnostic point of view. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires a morpho-functional approach. Non-linear microscopy techniques have the potential to bridge this gap by providing morpho-functional information in a label-free way. Here we employed multiple non-linear microscopy techniques, including CARS, TPF, and SHG to provide intrinsic optical contrast from various tissue components in both arterial wall and atherosclerotic plaques. CARS and TPF microscopy were used to respectively image lipid depositions within plaques and elastin in the arterial wall. Cholesterol deposition in the lumen and collagen in the arterial wall were selectively imaged by SHG microscopy and distinguished by forward-backward SHG ratio. Image pattern analysis allowed characterizing collagen organization in different tissue regions. The presented method has the potential to find a stable place in clinical setting as well as to be applied in vivo in the near future.

  14. Primary Stenting for Complex Atherosclerotic Plaques in Aortic and Iliac Stenoses

    SciTech Connect

    Onal, Baran; Ilgit, Erhan T.; Yuecel, Cem; Ozbek, Erdal; Vural, Murat; Akpek, Sergin

    1998-09-15

    Purpose: To evaluate the efficacy of primary stenting for complex atherosclerotic plaques in aortic and iliac stenoses that are not amenable to balloon angioplasty alone. Methods: Nineteen patients with complex atherosclerotic plaques were treated with a Palmaz stent (n= 19), Wallstent (n= 1), Strecker stent (n= 1), or Memotherm stent (n= 1). A total of 22 stenoses presenting with complex plaque morphology including ulcerated plaques, ulcerated plaques with focal aneurysms, plaques with heavy calcification, severely eccentric plaques, plaques with overhanging edge, and plaques with spontaneous dissection were stented. The lesions were in the aorta (n= 1), common iliac artery (n= 19), or external iliac artery (n= 2). Results: Immediate angiography after stent placement revealed restoration of patency of the stented segment. Focal aneurysms and ulcerated areas were occluded in the follow-up angiographies obtained 4-12 weeks after the procedure. In one case with poor distal runoff and multiple complex lesions of the iliac artery, subacute occlusion occurred. Clinical and angiographic follow-up (3-46 months) revealed patency of all other stented segments. Conclusion: Primary stenting is an effective and reliable approach for complex plaques in stenoses. Patency of the arterial segment with a smooth lumen can be created without the risk of acute complications such as distal embolization, dissection, or occlusion.

  15. Association between Human Plasma Chondroitin Sulfate Isomers and Carotid Atherosclerotic Plaques.

    PubMed

    Zinellu, Elisabetta; Lepedda, Antonio Junior; Cigliano, Antonio; Pisanu, Salvatore; Zinellu, Angelo; Carru, Ciriaco; Bacciu, Pietro Paolo; Piredda, Franco; Guarino, Anna; Spirito, Rita; Formato, Marilena

    2012-01-01

    Several studies have evidenced variations in plasma glycosaminoglycans content in physiological and pathological conditions. In normal human plasma GAGs are present mainly as undersulfated chondroitin sulfate (CS). The aim of the present study was to evaluate possible correlations between plasma CS level/structure and the presence/typology of carotid atherosclerotic lesion. Plasma CS was purified from 46 control subjects and 47 patients undergoing carotid endarterectomy showing either a soft or a hard plaque. The concentration and structural characteristics of plasma CS were assessed by capillary electrophoresis of constituent unsaturated fluorophore-labeled disaccharides. Results showed that the concentration of total CS isomers was increased by 21.4% (P < 0.01) in plasma of patients, due to a significant increase of undersulfated CS. Consequently, in patients the plasma CS charge density was significantly reduced with respect to that of controls. After sorting for plaque typology, we found that patients with soft plaques and those with hard ones differently contribute to the observed changes. In plasma from patients with soft plaques, the increase in CS content was not associated with modifications of its sulfation pattern. On the contrary, the presence of hard plaques was associated with CS sulfation pattern modifications in presence of quite normal total CS isomers levels. These results suggest that the plasma CS content and structure could be related to the presence and the typology of atherosclerotic plaque