Science.gov

Sample records for accelerated pc cine

  1. Accelerated phase-contrast cine MRI using k-t SPARSE-SENSE.

    PubMed

    Kim, Daniel; Dyvorne, Hadrien A; Otazo, Ricardo; Feng, Li; Sodickson, Daniel K; Lee, Vivian S

    2012-04-01

    Phase-contrast (PC) cine MRI is a promising method for assessment of pathologic hemodynamics, including cardiovascular and hepatoportal vascular dynamics, but its low data acquisition efficiency limits the achievable spatial and temporal resolutions within clinically acceptable breath-hold durations. We propose to accelerate PC cine MRI using an approach which combines compressed sensing and parallel imaging (k-t SPARSE-SENSE). We validated the proposed 6-fold accelerated PC cine MRI against 3-fold accelerated PC cine MRI with parallel imaging (generalized autocalibrating partially parallel acquisitions). With the programmable flow pump, we simulated a time varying waveform emulating hepatic blood flow. Normalized root mean square error between two sets of velocity measurements was 2.59%. In multiple blood vessels of 12 control subjects, two sets of mean velocity measurements were in good agreement (mean difference = -0.29 cm/s; lower and upper 95% limits of agreement = -5.26 and 4.67 cm/s, respectively). The mean phase noise, defined as the standard deviation of the phase in a homogeneous stationary region, was significantly lower for k-t SPARSE-SENSE than for generalized autocalibrating partially parallel acquisitions (0.05 ± 0.01 vs. 0.19 ± 0.06 radians, respectively; P < 0.01). The proposed 6-fold accelerated PC cine MRI pulse sequence with k-t SPARSE-SENSE is a promising investigational method for rapid velocity measurement with relatively high spatial (1.7 mm × 1.7 mm) and temporal (∼35 ms) resolutions.

  2. Evaluation of highly accelerated real-time cardiac cine MRI in tachycardia.

    PubMed

    Bassett, Elwin C; Kholmovski, Eugene G; Wilson, Brent D; DiBella, Edward V R; Dosdall, Derek J; Ranjan, Ravi; McGann, Christopher J; Kim, Daniel

    2014-02-01

    Electrocardiogram (ECG)-gated breath-hold cine MRI is considered to be the gold standard test for the assessment of cardiac function. However, it may fail in patients with arrhythmia, impaired breath-hold capacity and poor ECG gating. Although ungated real-time cine MRI may mitigate these problems, commercially available real-time cine MRI pulse sequences using parallel imaging typically yield relatively poor spatiotemporal resolution because of their low image acquisition efficiency. As an extension of our previous work, the purpose of this study was to evaluate the diagnostic quality and accuracy of eight-fold-accelerated real-time cine MRI with compressed sensing (CS) for the quantification of cardiac function in tachycardia, where it is challenging for real-time cine MRI to provide sufficient spatiotemporal resolution. We evaluated the performances of eight-fold-accelerated cine MRI with CS, three-fold-accelerated real-time cine MRI with temporal generalized autocalibrating partially parallel acquisitions (TGRAPPA) and ECG-gated breath-hold cine MRI in 21 large animals with tachycardia (mean heart rate, 104 beats per minute) at 3T. For each cine MRI method, two expert readers evaluated the diagnostic quality in four categories (image quality, temporal fidelity of wall motion, artifacts and apparent noise) using a Likert scale (1-5, worst to best). One reader evaluated the left ventricular functional parameters. The diagnostic quality scores were significantly different between the three cine pulse sequences, except for the artifact level between CS and TGRAPPA real-time cine MRI. Both ECG-gated breath-hold cine MRI and eight-fold accelerated real-time cine MRI yielded all four scores of ≥ 3.0 (acceptable), whereas three-fold-accelerated real-time cine MRI yielded all scores below 3.0, except for artifact (3.0). The left ventricular ejection fraction (LVEF) measurements agreed better between ECG-gated cine MRI and eight-fold-accelerated real-time cine MRI

  3. Highly accelerated real-time cardiac cine MRI using k-t SPARSE-SENSE.

    PubMed

    Feng, Li; Srichai, Monvadi B; Lim, Ruth P; Harrison, Alexis; King, Wilson; Adluru, Ganesh; Dibella, Edward V R; Sodickson, Daniel K; Otazo, Ricardo; Kim, Daniel

    2013-07-01

    For patients with impaired breath-hold capacity and/or arrhythmias, real-time cine MRI may be more clinically useful than breath-hold cine MRI. However, commercially available real-time cine MRI methods using parallel imaging typically yield relatively poor spatio-temporal resolution due to their low image acquisition speed. We sought to achieve relatively high spatial resolution (∼2.5 × 2.5 mm(2)) and temporal resolution (∼40 ms), to produce high-quality real-time cine MR images that could be applied clinically for wall motion assessment and measurement of left ventricular function. In this work, we present an eightfold accelerated real-time cardiac cine MRI pulse sequence using a combination of compressed sensing and parallel imaging (k-t SPARSE-SENSE). Compared with reference, breath-hold cine MRI, our eightfold accelerated real-time cine MRI produced significantly worse qualitative grades (1-5 scale), but its image quality and temporal fidelity scores were above 3.0 (adequate) and artifacts and noise scores were below 3.0 (moderate), suggesting that acceptable diagnostic image quality can be achieved. Additionally, both eightfold accelerated real-time cine and breath-hold cine MRI yielded comparable left ventricular function measurements, with coefficient of variation <10% for left ventricular volumes. Our proposed eightfold accelerated real-time cine MRI with k-t SPARSE-SENSE is a promising modality for rapid imaging of myocardial function.

  4. Accelerated high-frame-rate mouse heart cine-MRI using compressed sensing reconstruction.

    PubMed

    Motaal, Abdallah G; Coolen, Bram F; Abdurrachim, Desiree; Castro, Rui M; Prompers, Jeanine J; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

    2013-04-01

    We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensing reconstruction. Key to our approach is that we exploit the stochastic nature of the retrospective triggering acquisition scheme to produce an undersampled and random k-t space filling that allows for compressed sensing reconstruction and acceleration. As a standard, a self-gated FLASH sequence with a total acquisition time of 10 min was used to produce single-slice Cine movies of seven mouse hearts with 90 frames per cardiac cycle. Two times (2×) and three times (3×) k-t space undersampled Cine movies were produced from 2.5- and 1.5-min data acquisitions, respectively. The accelerated 90-frame Cine movies of mouse hearts were successfully reconstructed with a compressed sensing algorithm. The movies had high image quality and the undersampling artifacts were effectively removed. Left ventricular functional parameters, i.e. end-systolic and end-diastolic lumen surface areas and early-to-late filling rate ratio as a parameter to evaluate diastolic function, derived from the standard and accelerated Cine movies, were nearly identical.

  5. Functional imaging of murine hearts using accelerated self-gated UTE cine MRI.

    PubMed

    Motaal, Abdallah G; Noorman, Nils; de Graaf, Wolter L; Hoerr, Verena; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

    2015-01-01

    We introduce a fast protocol for ultra-short echo time (UTE) Cine magnetic resonance imaging (MRI) of the beating murine heart. The sequence involves a self-gated UTE with golden-angle radial acquisition and compressed sensing reconstruction. The self-gated acquisition is performed asynchronously with the heartbeat, resulting in a randomly undersampled kt-space that facilitates compressed sensing reconstruction. The sequence was tested in 4 healthy rats and 4 rats with chronic myocardial infarction, approximately 2 months after surgery. As a control, a non-accelerated self-gated multi-slice FLASH sequence with an echo time (TE) of 2.76 ms, 4.5 signal averages, a matrix of 192 × 192, and an acquisition time of 2 min 34 s per slice was used to obtain Cine MRI with 15 frames per heartbeat. Non-accelerated UTE MRI was performed with TE = 0.29 ms, a reconstruction matrix of 192 × 192, and an acquisition time of 3 min 47 s per slice for 3.5 averages. Accelerated imaging with 2×, 4× and 5× undersampled kt-space data was performed with 1 min, 30 and 15 s acquisitions, respectively. UTE Cine images up to 5× undersampled kt-space data could be successfully reconstructed using a compressed sensing algorithm. In contrast to the FLASH Cine images, flow artifacts in the UTE images were nearly absent due to the short echo time, simplifying segmentation of the left ventricular (LV) lumen. LV functional parameters derived from the control and the accelerated Cine movies were statistically identical.

  6. Accelerated three-dimensional cine phase contrast imaging using randomly undersampled echo planar imaging with compressed sensing reconstruction.

    PubMed

    Basha, Tamer A; Akçakaya, Mehmet; Goddu, Beth; Berg, Sophie; Nezafat, Reza

    2015-01-01

    The aim of this study was to implement and evaluate an accelerated three-dimensional (3D) cine phase contrast MRI sequence by combining a randomly sampled 3D k-space acquisition sequence with an echo planar imaging (EPI) readout. An accelerated 3D cine phase contrast MRI sequence was implemented by combining EPI readout with randomly undersampled 3D k-space data suitable for compressed sensing (CS) reconstruction. The undersampled data were then reconstructed using low-dimensional structural self-learning and thresholding (LOST). 3D phase contrast MRI was acquired in 11 healthy adults using an overall acceleration of 7 (EPI factor of 3 and CS rate of 3). For comparison, a single two-dimensional (2D) cine phase contrast scan was also performed with sensitivity encoding (SENSE) rate 2 and approximately at the level of the pulmonary artery bifurcation. The stroke volume and mean velocity in both the ascending and descending aorta were measured and compared between two sequences using Bland-Altman plots. An average scan time of 3 min and 30 s, corresponding to an acceleration rate of 7, was achieved for 3D cine phase contrast scan with one direction flow encoding, voxel size of 2 × 2 × 3 mm(3) , foot-head coverage of 6 cm and temporal resolution of 30 ms. The mean velocity and stroke volume in both the ascending and descending aorta were statistically equivalent between the proposed 3D sequence and the standard 2D cine phase contrast sequence. The combination of EPI with a randomly undersampled 3D k-space sampling sequence using LOST reconstruction allows a seven-fold reduction in scan time of 3D cine phase contrast MRI without compromising blood flow quantification.

  7. Stochastic Acceleration of Ions Driven by Pc1 Wave Packets

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Sibeck, D. G.; Tel'nikhin, A. A.; Kronberg, T. K.

    2015-01-01

    The stochastic motion of protons and He(sup +) ions driven by Pc1 wave packets is studied in the context of resonant particle heating. Resonant ion cyclotron heating typically occurs when wave powers exceed 10(exp -4) nT sq/Hz. Gyroresonance breaks the first adiabatic invariant and energizes keV ions. Cherenkov resonances with the electrostatic component of wave packets can also accelerate ions. The main effect of this interaction is to accelerate thermal protons to the local Alfven speed. The dependencies of observable quantities on the wave power and plasma parameters are determined, and estimates for the heating extent and rate of particle heating in these wave-particle interactions are shown to be in reasonable agreement with known empirical data.

  8. Stochastic acceleration of ions driven by Pc1 wave packets

    SciTech Connect

    Khazanov, G. V. Sibeck, D. G.; Tel'nikhin, A. A.; Kronberg, T. K.

    2015-07-15

    The stochastic motion of protons and He{sup +} ions driven by Pc1 wave packets is studied in the context of resonant particle heating. Resonant ion cyclotron heating typically occurs when wave powers exceed 10{sup −4} nT{sup 2}/Hz. Gyroresonance breaks the first adiabatic invariant and energizes keV ions. Cherenkov resonances with the electrostatic component of wave packets can also accelerate ions. The main effect of this interaction is to accelerate thermal protons to the local Alfven speed. The dependencies of observable quantities on the wave power and plasma parameters are determined, and estimates for the heating extent and rate of particle heating in these wave-particle interactions are shown to be in reasonable agreement with known empirical data.

  9. Cine-PC MR in assessment of cerebrospinal fluid velocity in the aqueduct of the midbrain correlated with intracranial pressure--initial study.

    PubMed

    Zhang, Bo; Li, Song-bai

    2012-02-01

    We assessed the changes in cerebrospinal fluid (CSF) hydrodynamics caused by barriers to CSF circulation, and determined the relationship between CSF velocity and intracranial pressure in the aqueduct of the midbrain. This was determined by correlating the CSF peak flow velocity with the intracranial pressure (ICP) obtained from a lumbar puncture (LP) procedure. The CSF peak flow velocity was measured by finger pulse-gated cine-phase contrast (PC) MR scan 8-12 hours after LP was performed in 28 patients. All patients were divided into 2 groups based on the directional patterns of the CSF net flow in the aqueduct of the midbrain over one cardiac cycle. The CSF peak net velocity (V(net)) was then correlated with ICP utilizing Pearson correlation analysis method, with significance difference assigned at the 5% level. Routine MR scanning revealed no abnormal findings in the brain when the direction of the CSF net flow is caudal. V(net) in the aqueduct of the midbrain was correlated positively with ICP (y(V)=0.011+0.002 ×(ICP), r=0.69, p<0.01). However, varying degrees of the hydrocephalus were observed in those patients who demonstrated a cranial direction of the CSF net flow. Our results indicate that non-invasive measurement of the CSF peak flow with cine-PC MR imaging can be related to the change of CSF circulation caused by the obstructions to the CSF circulation in the patients with various neurological disorders. This unique method may be a substantially useful tool to assess the changes in the ICP in the directional pattern.

  10. Highly accelerated cardiac cine parallel MRI using low-rank matrix completion and partial separability model

    NASA Astrophysics Data System (ADS)

    Lyu, Jingyuan; Nakarmi, Ukash; Zhang, Chaoyi; Ying, Leslie

    2016-05-01

    This paper presents a new approach to highly accelerated dynamic parallel MRI using low rank matrix completion, partial separability (PS) model. In data acquisition, k-space data is moderately randomly undersampled at the center kspace navigator locations, but highly undersampled at the outer k-space for each temporal frame. In reconstruction, the navigator data is reconstructed from undersampled data using structured low-rank matrix completion. After all the unacquired navigator data is estimated, the partial separable model is used to obtain partial k-t data. Then the parallel imaging method is used to acquire the entire dynamic image series from highly undersampled data. The proposed method has shown to achieve high quality reconstructions with reduction factors up to 31, and temporal resolution of 29ms, when the conventional PS method fails.

  11. MR imaging features of idiopathic thoracic spinal cord herniations using combined 3D-fiesta and 2D-PC Cine techniques.

    PubMed

    Ferré, J C; Carsin-Nicol, B; Hamlat, A; Carsin, M; Morandi, X

    2005-03-01

    Idiopathic thoracic spinal cord herniation (TISCH) is a rare cause of surgically treatable progressive myelopathy. The authors report 3 cases of TISCH diagnosed based on conventional T1- and T2-weighted Spin-Echo (SE) MR images in one case, and T1- and T2-weighted SE images combined with 3D-FIESTA (Fast Imaging Employing Steady state Acquisition) and 2D-Phase-Contrast Cine MR imaging in 2 cases. Conventional MRI findings usually provided the diagnosis. 3D-FIESTA images confirmed it, showing the herniated cord in the ventral epidural space. Moreover, in combination with 2D-Phase Contrast cine technique, it was a sensitive method to for the detection of associated pre- or postoperative cerebrospinal fluid spaces abnormalities.

  12. A methodology to accurately quantify patellofemoral cartilage contact kinematics by combining 3D image shape registration and cine-PC MRI velocity data.

    PubMed

    Borotikar, Bhushan S; Sipprell, William H; Wible, Emily E; Sheehan, Frances T

    2012-04-05

    Patellofemoral osteoarthritis and its potential precursor patellofemoral pain syndrome (PFPS) are common, costly, and debilitating diseases. PFPS has been shown to be associated with altered patellofemoral joint mechanics; however, an actual variation in joint contact stresses has not been established due to challenges in accurately quantifying in vivo contact kinematics (area and location). This study developed and validated a method for tracking dynamic, in vivo cartilage contact kinematics by combining three magnetic resonance imaging (MRI) techniques, cine-phase contrast (CPC), multi-plane cine (MPC), and 3D high-resolution static imaging. CPC and MPC data were acquired from 12 healthy volunteers while they actively extended/flexed their knee within the MRI scanner. Since no gold standard exists for the quantification of in vivo dynamic cartilage contact kinematics, the accuracy of tracking a single point (patellar origin relative to the femur) represented the accuracy of tracking the kinematics of an entire surface. The accuracy was determined by the average absolute error between the PF kinematics derived through registration of MPC images to a static model and those derived through integration of the CPC velocity data. The accuracy ranged from 0.47 mm to 0.77 mm for the patella and femur and from 0.68 mm to 0.86 mm for the patellofemoral joint. For purely quantifying joint kinematics, CPC remains an analytically simpler and more accurate (accuracy <0.33 mm) technique. However, for application requiring the tracking of an entire surface, such as quantifying cartilage contact kinematics, this combined imaging approach produces accurate results with minimal operator intervention.

  13. Implications of PC and KPC Jet Asymmetry to the Cosmic Ray Acceleration

    NASA Astrophysics Data System (ADS)

    Gizani, Nectaria A. B.

    We probe the role that the directional asymmetry, between relativistic outflows and kilo-parsec scale jets, play in the acceleration of cosmic rays. For this reason we use two powerful, nearby Active Galactic Nuclei (AGNs). These radio galaxies are atypical compared to the usual AGN as they contain ring-like features instead of hotspots. Our VLBI radio data have revealed a substantial misalignment between their small and large scale jets. Taking into account the overall information we have obtained about the AGNs themselves (VLA and VLBI radio data at 18 cm) and their clusters (X-ray observations) our study supports the present ideas of powerful radiogalaxies (radio quiet and radio loud) being sources of cosmic rays as well as their ability to accelarate the latter to ultra high energies.

  14. Exposure of PC12 cells to NGF/ethanol results in accelerated differentiation and altered gene expression

    SciTech Connect

    White, K.R.; Wooten, M.W. )

    1991-03-11

    The role of alcohols in affecting neuromorphogenesis was investigated in the pheochromocytoma cell line, PC12. The effect of ethanol at physiological concentrations in this system leads to accelerated neurite extension in the presence of suboptimal concentrations of NGF. Accelerated morphological differentiation was dependent upon the side chain length of the alcohol and not inhibited by pyrazole. Ethanol/NGF induced neurite extension can be blocked with 50nM of K252a, but not sphingozine, H7, H89, genistein or okadaic acid. Changes in the expression of 17 NGF-induced and/or neuronal transcripts were examined in relationship to time of NGF/ethanol exposure; dose of NGF/ethanol; and side-chain length of NFG/alcohol. The authors studies indicate that ethanol potentiates the effects of NFG and subsequent neurogenesis through both protein kinase C and cAMP-independent pathways. In addition, these data show that ethanol is capable of altering gene expression in a specific manner.

  15. Onjisaponin B Derived from Radix Polygalae Enhances Autophagy and Accelerates the Degradation of Mutant α-Synuclein and Huntingtin in PC-12 Cells

    PubMed Central

    Wu, An-Guo; Wong, Vincent Kam-Wai; Xu, Su-Wei; Chan, Wai-Kit; Ng, Choi-In; Liu, Liang; Law, Betty Yuen-Kwan

    2013-01-01

    Emerging evidence indicates important protective roles being played by autophagy in neurodegenerative disorders through clearance of aggregate-prone or mutant proteins. In the current study, we aimed to identify autophagy inducers from Chinese medicinal herbs as a potential neuroprotective agent that enhances the clearance of mutant huntingtin and α-synuclein in PC-12 cells. Through intensive screening using the green fluorescent protein-light chain 3 (GFP-LC3) autophagy detection platform, we found that the ethanol extracts of Radix Polygalae (Yuan Zhi) were capable of inducing autophagy. Further investigation showed that among three single components derived from Radix Polygalae—i.e., polygalacic acid, senegenin and onjisaponin B—onjisaponin B was able to induce autophagy and accelerate both the removal of mutant huntingtin and A53T α-synuclein, which are highly associated with Huntington disease and Parkinson disease, respectively. Our study further demonstrated that onjisaponin B induces autophagy via the AMPK-mTOR signaling pathway. Therefore, findings in the current study provide detailed insights into the protective mechanism of a novel autophagy inducer, which is valuable for further investigation as a new candidate agent for modulating neurodegenerative disorders through the reduction of toxicity and clearance of mutant proteins in the cellular level. PMID:24248062

  16. Cine recording ophthalmoscope

    NASA Technical Reports Server (NTRS)

    Fitzgerald, J. W.

    1972-01-01

    Camera system provides accurate photographic recording during acceleration of centrifuge and permits immediate observation of dynamic changes in retinal circulation by a closed-circuit television loop. System consists of main camera, remote control unit, and strobe power supply unit, and is used for fluorescein studies and dynamometry sequences.

  17. PC/104 Embedded IOCs at Jefferson Lab

    SciTech Connect

    Jianxun Yan, Trent Allison, Sue Witherspoon, Anthony Cuffe

    2009-10-01

    Jefferson Lab has developed embedded IOCs based on PC/104 single board computers (SBC) for low level control systems. The PC/104 IOCs run EPICS on top of the RTEMS operating system. Two types of control system configurations are used in different applications, PC/104 SBC with commercial PC/104 I/O cards and PC/104 SBC with custom designed FPGA-based boards. RTEMS was built with CEXP shell to run on the PC/104 SBC. CEXP shell provides the function of dynamic object loading, which is similar to the widely used VxWorks operating system. Standard software configurations were setup for PC/104 IOC application development to provide a familiar format for new projects as well as ease the conversion of applications from VME based IOCs to PC/104 IOCs. Many new projects at Jefferson Lab are going to employ PC/104 SBCs as IOCs and some applications have already been running them for accelerator operations. The PC/104 - RTEMS IOC provides a free open source Real-Time Operating System (RTOS), low cost/maintenance, easily installed/ configured, flexible, and reliable solution for accelerator control and 12GeV Upgrade projects.

  18. Compressed sensing reconstruction of cardiac cine MRI using golden angle spiral trajectories

    NASA Astrophysics Data System (ADS)

    Tolouee, Azar; Alirezaie, Javad; Babyn, Paul

    2015-11-01

    In dynamic cardiac cine Magnetic Resonance Imaging (MRI), the spatiotemporal resolution is limited by the low imaging speed. Compressed sensing (CS) theory has been applied to improve the imaging speed and thus the spatiotemporal resolution. The purpose of this paper is to improve CS reconstruction of under sampled data by exploiting spatiotemporal sparsity and efficient spiral trajectories. We extend k-t sparse algorithm to spiral trajectories to achieve high spatio temporal resolutions in cardiac cine imaging. We have exploited spatiotemporal sparsity of cardiac cine MRI by applying a 2D + time wavelet-Fourier transform. For efficient coverage of k-space, we have used a modified version of multi shot (interleaved) spirals trajectories. In order to reduce incoherent aliasing artifact, we use different random undersampling pattern for each temporal frame. Finally, we have used nonuniform fast Fourier transform (NUFFT) algorithm to reconstruct the image from the non-uniformly acquired samples. The proposed approach was tested in simulated and cardiac cine MRI data. Results show that higher acceleration factors with improved image quality can be obtained with the proposed approach in comparison to the existing state-of-the-art method. The flexibility of the introduced method should allow it to be used not only for the challenging case of cardiac imaging, but also for other patient motion where the patient moves or breathes during acquisition.

  19. Compressed sensing reconstruction of cardiac cine MRI using golden angle spiral trajectories.

    PubMed

    Tolouee, Azar; Alirezaie, Javad; Babyn, Paul

    2015-11-01

    In dynamic cardiac cine Magnetic Resonance Imaging (MRI), the spatiotemporal resolution is limited by the low imaging speed. Compressed sensing (CS) theory has been applied to improve the imaging speed and thus the spatiotemporal resolution. The purpose of this paper is to improve CS reconstruction of under sampled data by exploiting spatiotemporal sparsity and efficient spiral trajectories. We extend k-t sparse algorithm to spiral trajectories to achieve high spatio temporal resolutions in cardiac cine imaging. We have exploited spatiotemporal sparsity of cardiac cine MRI by applying a 2D+time wavelet-Fourier transform. For efficient coverage of k-space, we have used a modified version of multi shot (interleaved) spirals trajectories. In order to reduce incoherent aliasing artifact, we use different random undersampling pattern for each temporal frame. Finally, we have used nonuniform fast Fourier transform (NUFFT) algorithm to reconstruct the image from the non-uniformly acquired samples. The proposed approach was tested in simulated and cardiac cine MRI data. Results show that higher acceleration factors with improved image quality can be obtained with the proposed approach in comparison to the existing state-of-the-art method. The flexibility of the introduced method should allow it to be used not only for the challenging case of cardiac imaging, but also for other patient motion where the patient moves or breathes during acquisition.

  20. Motion adaptive patch-based low-rank approach for compressed sensing cardiac cine MRI.

    PubMed

    Yoon, Huisu; Kim, Kyung Sang; Kim, Daniel; Bresler, Yoram; Ye, Jong Chul

    2014-11-01

    One of the technical challenges in cine magnetic resonance imaging (MRI) is to reduce the acquisition time to enable the high spatio-temporal resolution imaging of a cardiac volume within a short scan time. Recently, compressed sensing approaches have been investigated extensively for highly accelerated cine MRI by exploiting transform domain sparsity using linear transforms such as wavelets, and Fourier. However, in cardiac cine imaging, the cardiac volume changes significantly between frames, and there often exist abrupt pixel value changes along time. In order to effectively sparsify such temporal variations, it is necessary to exploit temporal redundancy along motion trajectories. This paper introduces a novel patch-based reconstruction method to exploit geometric similarities in the spatio-temporal domain. In particular, we use a low rank constraint for similar patches along motion, based on the observation that rank structures are relatively less sensitive to global intensity changes, but make it easier to capture moving edges. A Nash equilibrium formulation with relaxation is employed to guarantee convergence. Experimental results show that the proposed algorithm clearly reconstructs important anatomical structures in cardiac cine image and provides improved image quality compared to existing state-of-the-art methods such as k-t FOCUSS, k-t SLR, and MASTeR.

  1. How to perform and interpret cine MR enterography.

    PubMed

    Wnorowski, Amelia M; Guglielmo, Flavius F; Mitchell, Donald G

    2015-11-01

    Magnetic resonance (MR) enterography has become a fundamental tool for small bowel evaluation. Multiphasic cine imaging is a useful component of MR enterography evaluation because it provides functional information about bowel motility. Cine MR enterography can be used to evaluate for strictures and adhesions. Bowel motility evaluation has been shown to increase pathologic lesion detection in Crohn's disease and has been incorporated into disease activity scoring systems. Currently, cine MR enterography remains underutilized. The purpose of this article is to outline how to perform and interpret cine MR enterography. The authors describe how to perform a multiphasic balanced steady state free precession sequence using different MR systems and give practical advice on how to display and interpret the cine sequence. Sample cases illustrate how the cine sequence complements standard MR enterography evaluation with T2 -weighted, contrast-enhanced T1 -weighted, and diffusion-weighted imaging.

  2. Requirements and Solutions for Archiving Scientific Data at CINES

    NASA Astrophysics Data System (ADS)

    Coutin, Stephane

    Historically an high-performance computing datacenter, the “Centre Informatique National de l’Enseignement Supérieur” (CINES) has also a mission of long term digital preservation. By coupling those two areas, it became obvious that CINES had to understand and take into account the requirements of scientific communities regarding their data life cycle, and more specifically their archiving requirements. We will present those requirements and describe the platforms CINES proposes for each service class.

  3. Biomimicry 1: PC.

    PubMed

    Cumberland, D C; Gunn, J; Malik, N; Holt, C M

    1998-01-01

    The surface properties of stents can be modified by coating them, for example with a polymer. Phosphorylcoline (PC) is the major component of the outer layer of the cell membrane. The haemo- and biocompatibility of a PC-containing polymer is thus based on biomimicry, and has been confirmed by several experiments showing much reduced thrombogenicity of PC-coated surfaces, and porcine coronary artery implants showing no sign of adverse effect. Clinical experience with the PC-coated BiodivYsio appears favourable. The PC coating can be tailored for take up and controlled elution of various drugs for stent-based local delivery, a property which is being actively explored.

  4. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-10-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  5. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-12-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  6. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-11-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  7. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2017-03-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  8. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-07-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  9. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-06-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  10. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2017-02-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  11. Cine CT technique for dynamic airway studies

    SciTech Connect

    Ell, S.R.; Jolles, H.; Keyes, W.D.; Galvin, J.R.

    1985-07-01

    The advent of cine CT scanning with its 50-msec data acquisition time promises a much wider range of dynamic CT studies. The authors describe a method for dynamic evaluation of the extrathoracic airway, which they believe has considerable potential application in nonfixed upper-airway disease, such as sleep apnea and stridor of unknown cause. Conventional CT is limited in such studies by long data acquisition time and can be used to study only prolonged maneuvers such as phonation. Fluoroscopy and digital subtraction studies are limited by relatively high radiation dose and inability to image all wall motions simultaneously.

  12. Recent experience with design and manufacture of cine lenses

    NASA Astrophysics Data System (ADS)

    Thorpe, Michael D.; Dalzell, Kristen E.

    2015-09-01

    Modern cine lenses require a high degree of aberration correction over a large and ever expanding image size. At low to medium volume production levels, these highly corrected designs also require a workable tolerance set and compensation scheme for successful manufacture. In this paper we discuss the design and manufacture of cine lenses with reference to current designs both internal and in the patent literature and some experience in design, tolerancing and manufacturing these lenses in medium volume production.

  13. High speed holographic cine-recorder

    NASA Astrophysics Data System (ADS)

    Snyder, Donald; Watts, David; Gordon, Joseph; Lysogorski, Charles; Powers, Aaron; Perry, John; Chenette, Eugene; Hudson, Roger; Young, Raymond

    2005-08-01

    Air Force Research Laboratory and North Dancer Labs researchers have completed the initial development and transition to operational use of a high-speed holographic movie system. This paper documents the first fully operational use of a novel and unique experimental capability for high-speed holographic movies and high-speed cinema interferometry. In this paper we document the initial experiments that were performed with the High Speed Holographic Recorder (HSHR) at the Munitions Directorate, Air Force Research Laboratory Site at Eglin, AFB, Florida. These experiments were performed to assess the possibilities for high-speed cine-laser holography combined with high-speed videography to document the formation and propagation of plumes of materials created by impact of high-speed projectiles. This paper details the development of the experimental procedures and initial results of this new tool. After successful integration and testing the system was delivered to Arnold Engineering Development Center.

  14. PC-FACS.

    PubMed

    Abernethy, Amy P

    2012-03-01

    PC-FACS (Fast Article Critical Summaries for Clinicians in Palliative Care), an electronic publication of the American Academy of Hospice and Palliative Medicine, provides palliative care clinicians with concise summaries of the most important findings from more than 50 medical and scientific journals. Each month, structured summaries and insightful commentaries on 6-10 articles help palliative care clinicians stay on top of the research that is critical to contemporary practice. PC-FACS is free to AAHPM members and members can earn up to 3 CME credits quarterly. Following are excerpts from recent issues, and comments from readers are welcomed at resources@aahpm.org.

  15. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2012-04-01

    PC-FACS (Fast Article Critical Summaries for Clinicians in Palliative Care), an electronic publication of the American Academy of Hospice and Palliative Medicine, provides palliative care clinicians with concise summaries of the most important findings from more than 50 medical and scientific journals. Each month, structured summaries and insightful commentaries on 6-10 articles help palliative care clinicians stay on top of the research that is critical to contemporary practice. PC-FACS is free to AAHPM members. Following are excerpts from recent issues, and comments from readers are welcomed at resources@aahpm.org.

  16. Computerized method for measurement of displacement vectors of target positions on EPID cine images in stereotactic radiotherapy

    NASA Astrophysics Data System (ADS)

    Arimura, Hidetaka; Anai, Shigeo; Yoshidome, Satoshi; Nakamura, Katsumasa; Shioyama, Yoshiyuki; Nomoto, Satoshi; Honda, Hiroshi; Onizuka, Yoshihiko; Terashima, Hiromi

    2007-03-01

    The purpose of this study was to develop a computerized method for measurement of displacement vectors of target position on electronic portal imaging device (EPID) cine images in a treatment without implanted markers. Our proposed method was based on a template matching technique with cross-correlation coefficient between a reference portal (RP) image and each consecutive portal (CP) image acquired by the EPID. EPID images with 512×384 pixels (pixel size:0.56 mm) were acquired in a cine mode at a sampling rate of 0.5 frame/sec by using an energy of 4, 6, or 10MV on linear accelerators. The displacement vector of the target on each cine image was determined from the position in which took the maximum cross-correlation value between the RP image and each CP image. We applied our method to EPID cine images of a lung phantom with a tumor model simulating respiratory motion, and 5 cases with a non-small cell lung cancer and one case of metastasis. For validation of our proposed method, displacement vectors of a target position calculated by our method were compared with those determined manually by two radiation oncologists. As a result, for lung phantom images, target displacements by our method correlated well with those by the oncologists (r=0.972 - 0.994). Correlation values for 4 cases ranged from 0.854 to 0.991, but the values for the other two cases were 0.609 and 0.644. This preliminary result suggested that our method may be useful for monitoring of displacement vectors of target positions without implanted markers in stereotactic radiotherapy.

  17. 21 CFR 892.1620 - Cine or spot fluorographic x-ray camera.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cine or spot fluorographic x-ray camera. 892.1620... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1620 Cine or spot fluorographic x-ray camera. (a) Identification. A cine or spot fluorographic x-ray camera is a device intended to...

  18. Computerized method for estimation of the location of a lung tumor on EPID cine images without implanted markers in stereotactic body radiotherapy

    NASA Astrophysics Data System (ADS)

    Arimura, H.; Egashira, Y.; Shioyama, Y.; Nakamura, K.; Yoshidome, S.; Anai, S.; Nomoto, S.; Honda, H.; Toyofuku, F.; Higashida, Y.; Onizuka, Y.; Terashima, H.

    2009-02-01

    The purpose of this study was to develop a computerized method for estimation of the location of a lung tumor in cine images on an electronic portal imaging device (EPID) without implanted markers during stereotactic body radiotherapy (SBRT). Each tumor region was segmented in the first EPID cine image, i.e., reference portal image, based on a multiple-gray level thresholding technique and a region growing technique, and then the image including the tumor region was cropped as a 'tumor template' image. The tumor location was determined as the position in which the tumor template image took the maximum cross-correlation value within each consecutive portal image, which was acquired in cine mode on the EPID in treatment. EPID images with 512 × 384 pixels (pixel size: 0.56 mm) were acquired at a sampling rate of 0.5 frame s-1 by using energies of 4, 6 or 10 MV on linear accelerators. We applied our proposed method to EPID cine images (226 frames) of 12 clinical cases (ages: 51-83, mean: 72) with a non-small cell lung cancer. As a result, the average location error between tumor points obtained by our method and the manual method was 1.47 ± 0.60 mm. This preliminary study suggests that our method based on the tumor template matching technique might be feasible for tracking the location of a lung tumor without implanted markers in SBRT.

  19. Comparison of Total Variation with a Motion Estimation Based Compressed Sensing Approach for Self-Gated Cardiac Cine MRI in Small Animal Studies

    PubMed Central

    Marinetto, Eugenio; Pascau, Javier; Desco, Manuel

    2014-01-01

    Purpose Compressed sensing (CS) has been widely applied to prospective cardiac cine MRI. The aim of this work is to study the benefits obtained by including motion estimation in the CS framework for small-animal retrospective cardiac cine. Methods We propose a novel B-spline-based compressed sensing method (SPLICS) that includes motion estimation and generalizes previous spatiotemporal total variation (ST-TV) methods by taking into account motion between frames. In addition, we assess the effect of an optimum weighting between spatial and temporal sparsity to further improve results. Both methods were implemented using the efficient Split Bregman methodology and were evaluated on rat data comparing animals with myocardial infarction with controls for several acceleration factors. Results ST-TV with optimum selection of the weighting sparsity parameter led to results similar to those of SPLICS; ST-TV with large relative temporal sparsity led to temporal blurring effects. However, SPLICS always properly corrected temporal blurring, independently of the weighting parameter. At acceleration factors of 15, SPLICS did not distort temporal intensity information but led to some artefacts and slight over-smoothing. At an acceleration factor of 7, images were reconstructed without significant loss of quality. Conclusion We have validated SPLICS for retrospective cardiac cine in small animal, achieving high acceleration factors. In addition, we have shown that motion modelling may not be essential for retrospective cine and that similar results can be obtained by using ST-TV provided that an optimum selection of the spatiotemporal sparsity weighting parameter is performed. PMID:25350290

  20. The initial Trinidad experience with Cine MRI in clinical cardiology.

    PubMed

    Thomas, C N; Maharaj, P; Bodapati, S; John, R; Rahaman, R; Henry, R; Brann, S

    2002-03-01

    We describe the initial Trinidad experience with Magnetic Resonance Imaging (MRI) and Cine MRI as a diagnostic tool in clinical cardiology. Six patients from the following categories were referred for Cine MRI evaluation: congenital heart disease, valvular heart disease, aortic diseases, cardiomyopathy and intracardiac mass. All patients underwent echocardiography. MRI and Cine MRI were performed on all patients using a Siemens Magnetom 1.0 Tesla MR system at MRI Trinidad and Tobago Ltd. Selected patients underwent Angiography and/or computed tomography (CT) scanning. Clinical data and images of the six patients evaluated are described. MRI and Cine MRI provided excellent anatomical and functional details of the heart and aorta in five patients with dissection of the aorta, aneurysm of the ascending aorta, suspected left ventricular apical thrombus, infiltrative cardiomyopathy and arrhythmogenic right ventricular dysplasia. Technical difficulty was experienced with one patient who had a congenital defect (common atrium). In this study, Cine MRI provided excellent images in all but one patient. This new noninvasive technique enhanced diagnostic capabilities and facilitated management in patients with certain cardiovascular diseases.

  1. Easy PC Astronomy

    NASA Astrophysics Data System (ADS)

    Duffett-Smith, Peter

    1996-11-01

    Easy PC Astronomy is the perfect book for everyone who wants to make easy and accurate astronomical calculations. The author supplies a simple but powerful script language called AstroScript on a disk, ready to use on any IBM PC-type computer. Equipped with this software, readers can compute complex but interesting astronomical results within minutes: from the time of moonrise or moonset anywhere in the world on any date, to the display of a lunar or solar eclipse on the computer screen--all within a few minutes of opening the book! The Sky Graphics feature of the software displays a detailed image of the sky as seen from any point on earth--at any time in the future or past--showing the constellations, planets, and a host of other features. Readers need no expert knowledge of astronomy, math or programming; the author provides full details of the calculations and formulas, which the reader can absorb or ignore as desired, and a comprehensive glossary of astronomical terms. Easy PC Astronomy is of immediate practical use to beginning and advanced amateur astronomers, students at all levels, science teachers, and research astronomers. Peter Duffett-Smith is at the Cavendish Laboratory of the University of Cambridge and is the author of Astronomy with Your Personal Computer (Cambridge University Press, 1990) and Practical Astronomy with Your Calculator (Cambridge University Press, 1989).

  2. Measurement of left ventricular dimensions with contrast-enhanced three-dimensional cine imaging facilitated by k-t SENSE

    PubMed Central

    Maredia, Neil; Kozerke, Sebastian; Larghat, Abdul; Abidin, Nik; Greenwood, John P; Boesiger, Peter; Plein, Sven

    2008-01-01

    Aim To compare three-dimensional (3D) k-t sensitivity encoded (k-t SENSE) cine cardiovascular magnetic resonance (CMR), before and after contrast administration, against standard 2D imaging for the assessment of left ventricular volumes and mass. Method Twenty-six subjects (14 volunteers, 12 patients) underwent multiple breathhold 2D balanced turbo-field echo cine CMR in addition to k-t SENSE accelerated 3D imaging (acceleration factor 5; 5× k-t SENSE), performed before and after administration of a high-relaxivity gadolinium-based contrast agent (Gadobutrolum). k-t acceleration factors of 7 and 10 were also assessed in six volunteers. Left ventricular end diastolic volume (EDV), end systolic volume (ESV), mass, and ejection fraction (EF) were calculated for each method. Results There was at least moderate agreement between the EDV, ESV, mass and EF calculated by 2D and 3D 5× k-t SENSE methods before contrast (concordance coefficients 0.92, 0.95, 0.97, 0.92, respectively). Agreement improved following contrast (concordance coefficients 0.97, 0.99, 0.98, 0.93, respectively). The 3D method underestimated all parameters compared to 2D (mean bias pre-contrast 6.1 ml, 0.6 ml, 3.5 g, 2.0% respectively). 3D image quality scores were significantly poorer than 2D, showing a non-significant trend to improvement following contrast administration. Parameters derived with k-t acceleration factors of 7 and 10 showed poorer agreement with 2D values. Conclusion Left ventricular volumes and mass are reliably assessed using 3D 5× k-t SENSE accelerated CMR. Contrast administration further improves agreement between 5× k-t SENSE and 2D-derived measurements. k-t acceleration factors greater than 5, though feasible, produce poorer agreement with 2D values. PMID:18507849

  3. Some Semantic Properties of Romanian Interrogatives: "Care" and "Cine."

    ERIC Educational Resources Information Center

    Vasiliu, E.

    The aim of this paper is to account for some semantic properties of Romanian interrogatives "ce" and "cine" by establishing some definite correlations between various contextual restrictions governing the use of these interrogative particles and the "meaning" which might be assigned to each of these particles in any…

  4. [Study on cine view of relative enhancement ratio map in O2-enhanced MRI].

    PubMed

    Fujii, Keita; Watanabe, Yasushi; Hanaoka, Shouhei; Motoyoshi, Kouichi; Goto, Masami; Amemiya, Shiori; Ino, Kenji; Akahane, Masaaki; Yano, Keiichi; Ohtomo, Kuni

    2014-11-01

    Magnetic resonance imaging (MRI) enables the evaluation of organ structure and function. Oxygen-enhanced MRI (O2-enhanced MRI) is a method for evaluating the pulmonary ventilation function using oxygen as a contrast agent. We created the Cine View of Relative Enhancement Ratio Map (Cine RER map) in O2-enhanced MRI to easily observe the contrast effect for clinical use. Relative enhancement ratio (RER) was determined as the pixel values of the Cine RER map. Moreover, six healthy volunteers underwent O2-enhanced MRI to determine the appropriate scale width of the Cine RER map. We calculated each RER and set 0 to 1.27 as the scale width of the Cine RER map based on the results. The Cine RER map made it possible to observe the contrast effect over time and thus is a convenient tool for evaluating the pulmonary ventilation function in O2-enhanced MRI.

  5. PC index and magnetic substorms

    NASA Astrophysics Data System (ADS)

    Troshichev, Oleg; Janzhura, Alexander; Sormakov, Dmitry; Podorozhkina, Nataly

    PC index is regarded as a proxy of the solar wind energy that entered into the magnetosphere as distinct from the AL and Dst indices, which are regarded as characteristics of the energy that realize in the magnetosphere in form of substorm and magnetic storms. This conclusion is based on results of analysis of relationships between the polar cap magnetic activity (PC-index) and parameters of the solar wind, on the one hand, relationships between changes of PC and development of magnetospheric substorms (AL-index) and magnetic storms (Dst-index), on the other hand. This paper describes in detail the following main results which demonstrate a strong connection between the behavior of PC and development of magnetic disturbances in the auroral zone: (1) magnetic substorms are preceded by the РС index growth (isolated and extended substorms) or long period of stationary PC (postponed substorms), (2) the substorm sudden onsets are definitely related to such PC signatures as leap and reverse, which are indicative of sharp increase of the PC growth rate, (3) substorms generally start to develop when the PC index exceeds the threshold level ~ 1.5±0.5 mV/m, irrespective of the substorm growth phase duration and type of substorm, (4) linear dependency of AL values on PC is typical of all substorm events irrespective of type and intensity of substorm.

  6. Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE

    NASA Astrophysics Data System (ADS)

    Gao, Hao; Allan, Andrew; McComb, Christie; Luo, Xiaoyu; Berry, Colin

    2014-07-01

    Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (- 0.18 ± 0.04 versus - 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p < 0.01). In the patient study, the peak strain patterns predicted by cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice.

  7. Spirometer-controlled cine magnetic resonance imaging used to diagnose tracheobronchomalacia in paediatric patients.

    PubMed

    Ciet, Pierluigi; Wielopolski, Piotr; Manniesing, Rashindra; Lever, Sandra; de Bruijne, Marleen; Morana, Giovanni; Muzzio, Pier Carlo; Lequin, Maarten H; Tiddens, Harm A W M

    2014-01-01

    Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard for diagnosing TBM; however it has major disadvantages, such as general anaesthesia. Cine computed tomography (CT) is a noninvasive alternative used to diagnose TBM, but its use in children is restricted by ionising radiation. Our aim was to evaluate the feasibility of spirometer-controlled cine magnetic resonance imaging (MRI) as an alternative to cine-CT in a retrospective study. 12 children with a mean age (range) of 12 years (7-17 years), suspected of having TBM, underwent cine-MRI. Static scans were acquired at end-inspiration and expiration covering the thorax using a three-dimensional spoiled gradient echo sequence. Three-dimensional dynamic scans were performed covering only the central airways. TBM was defined as a decrease of the trachea or bronchi diameter >50% at end-expiration in the static and dynamic scans. The success rate of the cine-MRI protocol was 92%. Cine-MRI was compared with bronchoscopy or chest CT in seven subjects. TBM was diagnosed by cine-MRI in seven (58%) out of 12 children and was confirmed by bronchoscopy or CT. In four patients, cine-MRI demonstrated tracheal narrowing that was not present in the static scans. Spirometer controlled cine-MRI is a promising technique to assess TBM in children and has the potential to replace bronchoscopy.

  8. Cine MRI of swallowing in patients with advanced oral or oropharyngeal carcinoma: a feasibility study.

    PubMed

    Kreeft, Anne Marijn; Rasch, Coen R N; Muller, Sara H; Pameijer, Frank A; Hallo, Eeke; Balm, Alfons J M

    2012-06-01

    Treatment of oral and oropharyngeal cancer may cause dysphagia. Purpose is to examine whether cine magnetic resonance imaging (MRI) yields additional information compared to standard examination in the evaluation of posttreatment dysphagia and mobility of oral and oropharyngeal structures. Thirty-four cine MRIs were made in 23 patients with advanced oral and oropharyngeal cancer, consisting of an MR image every 800 ms during swallowing which is compared to videofluoroscopy and quality of life questionnaires. A scoring system was applied to assess mobility on cine MR and videofluoroscopy leading to a score ranging from 9 to 17. Cine MRI of the swallowing in a midsagittal plane visualized the tumor (if located in the same plane), important anatomic structures and surgical reconstructions. Posttreatment mobility on cine MRI and videofluoroscopy was significantly diminished compared to pretreatment, mean pretreatment cine MRI score was 10.8 and posttreatment 12.4 (p = 0.017). Impaired mobility on cine MRI was significantly correlated to more swallowing problems (Spearman's correlation coefficient 0.73, p = 0.04), on videofluoroscopy not. Cine MRI is a promising new technique as an adjunct to standard examinations for evaluation of swallowing in patients with oral and oropharyngeal cancer. Cine MRI directly visualizes the dynamics of swallowing and allows evaluation of pre- and posttreatment differences. Abnormal findings are significantly correlated with subjective swallowing complaints of patients.

  9. Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE.

    PubMed

    Gao, Hao; Allan, Andrew; McComb, Christie; Luo, Xiaoyu; Berry, Colin

    2014-07-07

    Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (- 0.18 ± 0.04 versus - 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p < 0.01). In the patient study, the peak strain patterns predicted by cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice.

  10. Wanted: A Solid, Reliable PC

    ERIC Educational Resources Information Center

    Goldsborough, Reid

    2004-01-01

    This article discusses PC reliability, one of the most pressing issues regarding computers. Nearly a quarter century after the introduction of the first IBM PC and the outset of the personal computer revolution, PCs have largely become commodities, with little differentiating one brand from another in terms of capability and performance. Most of…

  11. NASA PC software evaluation project

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Kuan, Julie C.

    1986-01-01

    The USL NASA PC software evaluation project is intended to provide a structured framework for facilitating the development of quality NASA PC software products. The project will assist NASA PC development staff to understand the characteristics and functions of NASA PC software products. Based on the results of the project teams' evaluations and recommendations, users can judge the reliability, usability, acceptability, maintainability and customizability of all the PC software products. The objective here is to provide initial, high-level specifications and guidelines for NASA PC software evaluation. The primary tasks to be addressed in this project are as follows: to gain a strong understanding of what software evaluation entails and how to organize a structured software evaluation process; to define a structured methodology for conducting the software evaluation process; to develop a set of PC software evaluation criteria and evaluation rating scales; and to conduct PC software evaluations in accordance with the identified methodology. Communication Packages, Network System Software, Graphics Support Software, Environment Management Software, General Utilities. This report represents one of the 72 attachment reports to the University of Southwestern Louisiana's Final Report on NASA Grant NGT-19-010-900. Accordingly, appropriate care should be taken in using this report out of context of the full Final Report.

  12. Frame average optimization of cine-mode EPID images used for routine clinical in vivo patient dose verification of VMAT deliveries

    SciTech Connect

    McCowan, P. M.; McCurdy, B. M. C.

    2016-01-15

    Purpose: The in vivo 3D dose delivered to a patient during volumetric modulated arc therapy (VMAT) delivery can be calculated using electronic portal imaging device (EPID) images. These images must be acquired in cine-mode (i.e., “movie” mode) in order to capture the time-dependent delivery information. The angle subtended by each cine-mode EPID image during an arc can be changed via the frame averaging number selected within the image acquisition software. A large frame average number will decrease the EPID’s angular resolution and will result in a decrease in the accuracy of the dose information contained within each image. Alternatively, less EPID images acquired per delivery will decrease the overall 3D patient dose calculation time, which is appealing for large-scale clinical implementation. Therefore, the purpose of this study was to determine the optimal frame average value per EPID image, defined as the highest frame averaging that can be used without an appreciable loss in 3D dose reconstruction accuracy for VMAT treatments. Methods: Six different VMAT plans and six different SBRT-VMAT plans were delivered to an anthropomorphic phantom. Delivery was carried out on a Varian 2300ix model linear accelerator (Linac) equipped with an aS1000 EPID running at a frame acquisition rate of 7.5 Hz. An additional PC was set up at the Linac console area, equipped with specialized frame-grabber hardware and software packages allowing continuous acquisition of all EPID frames during delivery. Frames were averaged into “frame-averaged” EPID images using MATLAB. Each frame-averaged data set was used to calculate the in vivo dose to the patient and then compared to the single EPID frame in vivo dose calculation (the single frame calculation represents the highest possible angular resolution per EPID image). A mean percentage dose difference of low dose (<20% prescription dose) and high dose regions (>80% prescription dose) was calculated for each frame averaged

  13. Verification of respiratory-gated radiotherapy with new real-time tumour-tracking radiotherapy system using cine EPID images and a log file

    NASA Astrophysics Data System (ADS)

    Shiinoki, Takehiro; Hanazawa, Hideki; Yuasa, Yuki; Fujimoto, Koya; Uehara, Takuya; Shibuya, Keiko

    2017-02-01

    A combined system comprising the TrueBeam linear accelerator and a new real-time tumour-tracking radiotherapy system, SyncTraX, was installed at our institution. The objectives of this study are to develop a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine electronic portal image device (EPID) images and a log file and to verify this treatment in clinical cases. Respiratory-gated radiotherapy was performed using TrueBeam and the SyncTraX system. Cine EPID images and a log file were acquired for a phantom and three patients during the course of the treatment. Digitally reconstructed radiographs (DRRs) were created for each treatment beam using a planning CT set. The cine EPID images, log file, and DRRs were analysed using a developed software. For the phantom case, the accuracy of the proposed method was evaluated to verify the respiratory-gated radiotherapy. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker used as an internal surrogate were calculated to evaluate the gating accuracy and set-up uncertainty in the superior–inferior (SI), anterior–posterior (AP), and left–right (LR) directions. The proposed method achieved high accuracy for the phantom verification. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker were  ⩽3 mm and  ±3 mm in the SI, AP, and LR directions. We proposed a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine EPID images and a log file and showed that this treatment is performed with high accuracy in clinical cases. This work was partly presented at the 58th Annual meeting of American Association of Physicists in Medicine.

  14. Verification of respiratory-gated radiotherapy with new real-time tumour-tracking radiotherapy system using cine EPID images and a log file.

    PubMed

    Shiinoki, Takehiro; Hanazawa, Hideki; Yuasa, Yuki; Fujimoto, Koya; Uehara, Takuya; Shibuya, Keiko

    2017-02-21

    A combined system comprising the TrueBeam linear accelerator and a new real-time tumour-tracking radiotherapy system, SyncTraX, was installed at our institution. The objectives of this study are to develop a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine electronic portal image device (EPID) images and a log file and to verify this treatment in clinical cases. Respiratory-gated radiotherapy was performed using TrueBeam and the SyncTraX system. Cine EPID images and a log file were acquired for a phantom and three patients during the course of the treatment. Digitally reconstructed radiographs (DRRs) were created for each treatment beam using a planning CT set. The cine EPID images, log file, and DRRs were analysed using a developed software. For the phantom case, the accuracy of the proposed method was evaluated to verify the respiratory-gated radiotherapy. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker used as an internal surrogate were calculated to evaluate the gating accuracy and set-up uncertainty in the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions. The proposed method achieved high accuracy for the phantom verification. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker were  ⩽3 mm and  ±3 mm in the SI, AP, and LR directions. We proposed a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine EPID images and a log file and showed that this treatment is performed with high accuracy in clinical cases.

  15. Detection and correction for EPID and gantry sag during arc delivery using cine EPID imaging

    SciTech Connect

    Rowshanfarzad, Pejman; Sabet, Mahsheed; O'Connor, Daryl J.; McCowan, Peter M.; McCurdy, Boyd M. C.; Greer, Peter B.

    2012-02-15

    Purpose: Electronic portal imaging devices (EPIDs) have been studied and used for pretreatment and in-vivo dosimetry applications for many years. The application of EPIDs for dosimetry in arc treatments requires accurate characterization of the mechanical sag of the EPID and gantry during rotation. Several studies have investigated the effects of gravity on the sag of these systems but each have limitations. In this study, an easy experiment setup and accurate algorithm have been introduced to characterize and correct for the effect of EPID and gantry sag during arc delivery. Methods: Three metallic ball bearings were used as markers in the beam: two of them fixed to the gantry head and the third positioned at the isocenter. EPID images were acquired during a 360 deg. gantry rotation in cine imaging mode. The markers were tracked in EPID images and a robust in-house developed MATLAB code was used to analyse the images and find the EPID sag in three directions as well as the EPID + gantry sag by comparison to the reference gantry zero image. The algorithm results were then tested against independent methods. The method was applied to compare the effect in clockwise and counter clockwise gantry rotations and different source-to-detector distances (SDDs). The results were monitored for one linear accelerator over a course of 15 months and six other linear-accelerators from two treatment centers were also investigated using this method. The generalized shift patterns were derived from the data and used in an image registration algorithm to correct for the effect of the mechanical sag in the system. The Gamma evaluation (3%, 3 mm) technique was used to investigate the improvement in alignment of cine EPID images of a fixed field, by comparing both individual images and the sum of images in a series with the reference gantry zero image. Results: The mechanical sag during gantry rotation was dependent on the gantry angle and was larger in the in-plane direction, although

  16. 21 CFR 892.1620 - Cine or spot fluorographic x-ray camera.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cine or spot fluorographic x-ray camera. 892.1620 Section 892.1620 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1620 Cine or spot fluorographic...

  17. 21 CFR 892.1620 - Cine or spot fluorographic x-ray camera.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cine or spot fluorographic x-ray camera. 892.1620 Section 892.1620 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1620 Cine or spot fluorographic...

  18. 21 CFR 892.1620 - Cine or spot fluorographic x-ray camera.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cine or spot fluorographic x-ray camera. 892.1620 Section 892.1620 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1620 Cine or spot fluorographic...

  19. 21 CFR 892.1620 - Cine or spot fluorographic x-ray camera.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cine or spot fluorographic x-ray camera. 892.1620 Section 892.1620 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1620 Cine or spot fluorographic...

  20. High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function.

    PubMed

    Coolen, Bram F; Abdurrachim, Desiree; Motaal, Abdallah G; Nicolay, Klaas; Prompers, Jeanine J; Strijkers, Gustav J

    2013-03-01

    To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered at will to increase the frame rate because of gradient hardware, spatial resolution, and signal-to-noise limitations. To overcome these limitations associated with electrocardiography-triggered Cine MRI, in this paper, we introduce a retrospectively triggered Cine MRI protocol capable of producing high-resolution high frame rate Cine MRI of the mouse heart for addressing left ventricular diastolic function. Simulations were performed to investigate the influence of MRI sequence parameters and the k-space filling trajectory in relation to the desired number of frames per cardiac cycle. An optimized protocol was applied in vivo and compared with electrocardiography-triggered Cine for which a high-frame rate could only be achieved by several interleaved acquisitions. Retrospective high frame rate Cine MRI proved superior to the interleaved electrocardiography-triggered protocols. High spatial-resolution Cine movies with frames rates up to 80 frames per cardiac cycle were obtained in 25 min. Analysis of left ventricular filling rate curves allowed accurate determination of early and late filling rates and revealed subtle impairments in left ventricular diastolic function of diabetic mice in comparison with nondiabetic mice.

  1. 75 FR 62002 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the AMM... and B2-H4 models. For PC-6 models other than B2-H2 and B2-H4, a new ALS document has been implemented... Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the...

  2. 76 FR 5467 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-01

    ... Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the AMM... and B2-H4 models. For PC-6 models other than B2-H2 and B2-H4, a new ALS document has been implemented... Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the...

  3. PC-Based Applications Programming on the SRS Control System.

    NASA Astrophysics Data System (ADS)

    Martlew, Brian; Owen, Hywel; Pugh, Martin; Rawlinson, Bill; Smith, Susan

    1997-05-01

    The CERN PC-based ISOLDE control system has been installed at the SRS electron storage ring at Daresbury Laboratory. The use of Windows NT for the control consoles together with PC and VME front-end computers running under several operating systems has resulted in a flexible and reliable system for accelerator control. The implementation and philosophy of control application programs, based around a suite of Microsoft Visual Basic and Excel programs, is described. In particular, the use of Excel to provide adaptable programs online allows rapid generation of new control functions; orbit correction and servoing at the application level are described as examples of this.

  4. Remote estimation of phycocyanin (PC) for inland waters coupled with YSI PC fluorescence probe.

    PubMed

    Song, Kaishan; Li, Lin; Tedesco, Lenore; Clercin, Nicole; Hall, Bob; Li, Shuai; Shi, Kun; Liu, Dawei; Sun, Ying

    2013-08-01

    Nuisance cyanobacterial blooms degrade water resources through accelerated eutrophication, odor generation, and production of toxins that cause adverse effects on human health. Quick and effective methods for detecting cyanobacterial abundance in drinking water supplies are urgently needed to compliment conventional laboratory methods, which are costly and time consuming. Hyperspectral remote sensing can be an effective approach for rapid assessment of cyanobacterial blooms. Samples (n=250) were collected from five drinking water sources in central Indiana (CIN), USA, and South Australia (SA), which experience nuisance cyanobacterial blooms. In situ hyperspectral data were used to develop models by relating spectral signal with handheld fluorescence probe (YSI 6600 XLM-SV) measured phycocyanin (PC in cell/ml), a proxy pigment unique for indicating the presence of cyanobacteria. Three-band model (TBM), which is effective for chlorophyll-a estimates, was tuned to quantify cyanobacteria coupled with the PC probe measured cyanobacteria. As a comparison, two band model proposed by Simis et al. (Limnol Oceanogr, 50(11): 237-245, 2005; denoted as SM05) was paralleled to evaluate TBM model performance. Our observation revealed a high correlation between measured and estimated PC for SA dataset (R (2) =0.96; range: 534-20,200 cell/ml) and CIN dataset (R (2) =0.88; range: 1,300-44,500 cell/ml). The potential of this modeling approach for imagery data were assessed by simulated ESA/Centinel3/OLCI spectra, which also resulted in satisfactory performance with the TBM for both SA dataset (RMSE % =26.12) and CIN dataset (RMSE % =34.49). Close relationship between probe-measured PC and laboratory measured cyanobacteria biovolume was observed (R (2) =0.93, p<0.0001) for the CIN dataset, indicating a stable performance for PC probe. Based on our observation, field spectroscopic measurement coupled with PC probe measurements can provide quantitative cyanobacterial bloom

  5. Thigh muscle function in stroke patients revealed by velocity-encoded cine phase-contrast magnetic resonance imaging.

    PubMed

    Wen, Hongmei; Dou, Zulin; Finni, Taija; Havu, Marko; Kang, Zhuang; Cheng, Shumei; Sipilä, Sarianna; Sinha, Shantanu; Usenius, Jussi-Pekka; Cheng, Sulin

    2008-06-01

    Current methods of clinical assessment of muscle coordination and function after stroke do not provide information on deep muscles. The objective of this study was to examine how stroke affects both superficial and deep muscles' coordination and whether muscle function improves after rehabilitation. Muscle function, coordination, and activity of quadriceps femoris (QF) and hamstrings were evaluated in 10 stroke patients with mild hemiparesis and in 6 controls using velocity-encoded cine phase-contrast magnetic resonance imaging (VE-PC MRI), surface electromyography (sEMG), and maximal voluntary isometric contraction torque (MVC). At baseline, the peak muscle velocity of the rectus femoris (RF) and the ratio between the peak velocities of the RF and vasti were lower in the affected limb (AL) of stroke patients than in controls. Co-contraction of agonists and antagonists was higher in the AL than in controls. Muscle activity measured by sEMG showed similar behavior. After rehabilitation, the activity ratio of hamstrings and adductors to QF decreased slightly toward normal so there were no significant differences between the AL and controls. Impaired biarticular RF muscle function in stroke patients is the limiting factor during knee extension-flexion movements. After rehabilitation, improved functional performance was partly explained by the fact that the activities of the RF and vasti became more synchronized. VE-PC MRI can provide quantitative in vivo measurements of both superficial and deep muscles, and the information acquired after stroke can be utilized to render therapy more efficient and individually tailored.

  6. An experimental study on use of 7T MRI for evaluation of myocardial infarction in SD rats transfected with pcDNA 3.1(+)/VEGF121 plasmid

    PubMed Central

    Zhang, Yan; Tian, Ruiqing; Shen, Xiangchun; Chen, Yushu; Chen, Wei; Gan, Lu; Shen, Guiquan; Ju, Haiyue; Yang, Li; Gao, Fabao

    2016-01-01

    This study aims to build the myocardial infarction model in SD rats transfected with pcDNA 3.1(+)/VEGF121 plasmid and study the effect of the transfection using 7T MRI. Twenty-four male SD rats were randomly divided into 2 groups, pcDNA 3.1(+)/VEGF121 plasmid transfection group (with improved coronary perfusion delivery) and myocardial infarction model group. Cardiac cine magnetic resonance imaging (Cine-MRI), T2-mapping and late gadolinium enhancement (LGE) cardiac imaging were performed at 24 h, 48 h, 72 h and 7 d after myocardial infarction, respectively. The signal intensity, area at risk (AAR), myocardium infarction core (MIC) and salvageable myocardial zone (SMZ) were compared. The hearts were harvested for anatomic characterization, which was related to pathological examination (TTC staining, HE staining, Masson staining and immunohistochemical staining). The Cine-MRI results showed that pcDNA 3.1(+)/VEGF121 plasmid transfection group had higher end-diastolic volume (EDV) with a reduction in MIC and SMZ, as compared with the myocardial infarction model group. MIC, SMZ and AAR of the plasmid transfection declined over time. At 7 d, the two groups did not differ significantly in AAR and T2 value. According to Western Blotting, VEGF was up-regulated, while CaSR and caspase-3 were downregulated in the plasmid transfection group, as compared with the model group. In conclusion, a good treatment effect was achieved by coronary perfusion of pcDNA 3.1(+)/VEGF121 plasmid. 7T CMR sequences provide a non-invasive quantification of the treatment efficacy. However, the assessment of myocardial injury using T2 value and AAR in the presence of edema is less accurate. The myocardial protection of the plasmid transfection group may be related to the inhibition of myocardial apoptosis, vascular endothelial cell (VEC) proliferation and collagen proliferation. The CaSR signaling pathway may contribute to reversing the apoptosis. PMID:27648128

  7. Application of phase-contrast cine magnetic resonance imaging in endoscopic aqueductoplasty.

    PubMed

    Chen, Guoqiang; Zheng, Jiaping; Xiao, Qing; Liu, Yunsheng

    2013-06-01

    The aim of this study was to evaluate the application of phase-contrast cine magnetic resonance imaging (MRI) in endoscopic aqueductoplasty (EA) for patients with obstructive hydrocephalus. The clinical diagnosis of hydrocephalus caused by aqueduct obstruction in 23 patients was confirmed by phase-contrast cine MRI examination. The patients were treated with EA and MRI was repeated during the follow-up. The cerebrospinal fluid (CSF) flow velocity in the aqueduct was measured to determine whether the aqueduct was obstructed. The results of phase-contrast cine MRI examinations indicated that there was no CSF flow in the aqueduct for all patients prior to surgery. Aqueductoplasty was successfully performed in all patients. The results of phase-contrast cine MRI examinations performed a week after surgery demonstrated an average CSF flow velocity of 4.74±1.77 cm/sec. During the follow-up, intracranial hypertension recurred in two patients in whom CSF flow was not observed in the aqueduct by the phase-contrast cine MRI scan. Aqueduct re-occlusion was revealed by an endoscopic exploration. By measuring the CSF flow velocity, phase-contrast cine MRI accurately identifies aqueduct obstruction. Cine MRI is a nontraumatic, simple and reliable method for determining whether the aqueduct is successfully opened following aqueductoplasty.

  8. D2PC sensitivity analysis

    SciTech Connect

    Lombardi, D.P.

    1992-08-01

    The Chemical Hazard Prediction Model (D2PC) developed by the US Army will play a critical role in the Chemical Stockpile Emergency Preparedness Program by predicting chemical agent transport and dispersion through the atmosphere after an accidental release. To aid in the analysis of the output calculated by D2PC, this sensitivity analysis was conducted to provide information on model response to a variety of input parameters. The sensitivity analysis focused on six accidental release scenarios involving chemical agents VX, GB, and HD (sulfur mustard). Two categories, corresponding to conservative most likely and worst case meteorological conditions, provided the reference for standard input values. D2PC displayed a wide variety of sensitivity to the various input parameters. The model displayed the greatest overall sensitivity to wind speed, mixing height, and breathing rate. For other input parameters, sensitivity was mixed but generally lower. Sensitivity varied not only with parameter, but also over the range of values input for a single parameter. This information on model response can provide useful data for interpreting D2PC output.

  9. Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Sidorin, Anatoly

    2010-01-01

    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.

  10. Cine-magnetic resonance imaging evaluation of communication between middle cranial fossa arachnoid cysts and cisterns.

    PubMed

    Eguchi, T; Taoka, T; Nikaido, Y; Shiomi, K; Fujimoto, T; Otsuka, H; Takeuchi, H

    1996-06-01

    Cine-magnetic resonance (MR) imaging examinations were performed in 10 patients with middle cranial fossa arachnoid cysts to evaluate communication between the cysts and the normal cerebrospinal fluid (CSF) space. Eight of 10 patients were evaluated by time of flight cine-MR imaging, and two by phase contrast cine-MR imaging. Two patients underwent membranectomy of the cysts, and were evaluated both pre- and postoperatively. Computed tomography cisternography was used to confirm communication between the cysts and the surrounding cisterns. Pulsatile fluid motion within the cysts was present in all patients. However, marked fluid motion and jet flow between the cysts and the surrounding cisterns were only observed in communicating cysts. In the two patients who underwent membranectomy, postoperative examination found greater fluid motion and jet flow not previously present. Cine-MR imaging demonstration of marked pulsatile fluid motion accompanied by jet flow suggests that a cyst communicates with the normal CSF space.

  11. Poster session ELIPGRID-PC

    SciTech Connect

    Davidson, J.R.

    1995-02-01

    ELIPGRID-PC, a new personal computer program, has been developed to provide easy access to Singer`s ELIPGRID algorithm for hot-spot detection probabilities. Three features of the program are the ability to determine: (1) the grid size required for specified conditions, (2) the smallest hot spot that can be sampled with a given probability, and (3) the approximate grid size resulting from specified conditions and sampling cost. ELIPGRID-PC also provides probability of detection versus cost data for graphing with spreadsheets or graphics software. The program has been successfully tested using Singer`s published ELIPGRID results. An apparent error in the published ELIPGRID code has been uncovered and an appropriate modification incorporated into the new program.

  12. Cine viability magnetic resonance imaging of the heart without increased scan time.

    PubMed

    Hassanein, Azza S; Khalifa, Ayman M; Ibrahim, El-Sayed H

    2016-02-01

    Cardiac magnetic resonance imaging (MRI) provides information about myocardial morphology, function, and viability from cine, tagged, and late gadolinium enhancement (LGE) images, respectively. While the cine and tagged images are acquired in a time-resolved fashion, the LGE images are acquired at a single timeframe. The purpose of this work is to develop a method for generating cine LGE images without additional scan time. The motion field is extracted from the tagged images, and is then used to guide the deformation of the infarcted region from the acquired LGE image at the acquired timeframe to any other timeframe. Major techniques for motion estimation, including harmonic phase (HARP) and optical flow analysis, are tested in this work for motion estimation. The proposed method is tested on numerical phantom and images from four human subjects. The generated cine LGE images showed both viability and wall motion information in the same set of images without additional scan time or image misregistration problems. The band-pass optical flow analysis resulted in the most accurate motion estimation compared to other methods, especially HARP, which fails to track points at the myocardial boundary. Infarct transmurality from the generated images showed good agreement with myocardial strain, and wall thickening showed good agreement with that measured from conventional cine images. In conclusion, the developed technique allows for generating cine LGE images that enable simultaneous display of wall motion and viability information. The generated images could be useful for estimating myocardial contractility reserve and for treatment prognosis.

  13. 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.

  14. SU-E-J-234: Application of a Breathing Motion Model to ViewRay Cine MR Images

    SciTech Connect

    O’Connell, D. P.; Thomas, D. H.; Dou, T. H.; Lamb, J. M.; Yang, L.; Low, D. A.

    2015-06-15

    Purpose: A respiratory motion model previously used to generate breathing-gated CT images was used with cine MR images. Accuracy and predictive ability of the in-plane models were evaluated. Methods: Sagittalplane cine MR images of a patient undergoing treatment on a ViewRay MRI/radiotherapy system were acquired before and during treatment. Images were acquired at 4 frames/second with 3.5 × 3.5 mm resolution and a slice thickness of 5 mm. The first cine frame was deformably registered to following frames. Superior/inferior component of the tumor centroid position was used as a breathing surrogate. Deformation vectors and surrogate measurements were used to determine motion model parameters. Model error was evaluated and subsequent treatment cines were predicted from breathing surrogate data. A simulated CT cine was created by generating breathing-gated volumetric images at 0.25 second intervals along the measured breathing trace, selecting a sagittal slice and downsampling to the resolution of the MR cines. A motion model was built using the first half of the simulated cine data. Model accuracy and error in predicting the remaining frames of the cine were evaluated. Results: Mean difference between model predicted and deformably registered lung tissue positions for the 28 second preview MR cine acquired before treatment was 0.81 +/− 0.30 mm. The model was used to predict two minutes of the subsequent treatment cine with a mean accuracy of 1.59 +/− 0.63 mm. Conclusion: Inplane motion models were built using MR cine images and evaluated for accuracy and ability to predict future respiratory motion from breathing surrogate measurements. Examination of long term predictive ability is ongoing. The technique was applied to simulated CT cines for further validation, and the authors are currently investigating use of in-plane models to update pre-existing volumetric motion models used for generation of breathing-gated CT planning images.

  15. PARTICLE ACCELERATOR

    DOEpatents

    Teng, L.C.

    1960-01-19

    ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the cyclotron, a magnetic shield between the ring accelerator and the cyclotron, and a magnetic inflector within the ring accelerator.

  16. Electronic fluorography for the performance of cine hysterosalpingography

    SciTech Connect

    Freedman, M.; Farber, M.; Edelstein, G.; Tildon-Burton, J.; Gill, E.

    1987-04-01

    We used electronic fluorography to perform hysterosalpingography in 25 women with infertility or abnormal bleeding. In contrast to the conventional modality of fluoroscopy with intermittent permanent imaging, an image intensifier was used to periodically record dye injection on a moving tape (cine hysterosalpingography). The mean number of electronic fluorographs taken per patient was 10.8 +/- 3.12 (mean +/- SD). The mean radiation exposure per patient for electronic fluorography was 113.4 +/- 52 versus 112 +/- 52.4 mR when a single conventional radiographic image was taken. We conclude that electronic fluorography is a simple yet accurate radiographic method that delivers to the gonads approximately one-eleventh the dose of ionizing radiation that current standard techniques do, and should be accepted as an alternative diagnostic modality.

  17. Cine: Line excitation by infrared fluorescence in cometary atmospheres

    NASA Astrophysics Data System (ADS)

    de Val-Borro, Miguel; Cordiner, Martin A.; Milam, Stefanie N.; Charnley, Steven B.

    2017-03-01

    CINE is a Python module for calculating infrared pumping efficiencies that can be applied to the most common molecules found in cometary comae such as water, hydrogen cyanide or methanol. Excitation by solar radiation of vibrational bands followed by radiative decay to the ground vibrational state is one of the main mechanisms for molecular excitation in comets. This code calculates the effective pumping rates for rotational levels in the ground vibrational state scaled by the heliocentric distance of the comet. Line transitions are queried from the latest version of the HITRAN spectroscopic repository using the astroquery affiliated package of astropy. Molecular data are obtained from the LAMDA database. These coefficients are useful for modeling rotational emission lines observed in cometary spectra at sub-millimeter wavelengths. Combined with computational methods to solve the radiative transfer equations based, e.g., on the Monte Carlo algorithm, this model can retrieve production rates and rotational temperatures from the observed emission spectrum.

  18. PC25{trademark} product and manufacturing experience

    SciTech Connect

    Hall, E.W.; Riley, W.C.; Sandelli, G.J.

    1996-12-31

    Product and manufacturing experience accumulated since the beginning of PC25. A production in 1991 provides a strong base of demonstration and experience for establishing future improvements to the PC25 power plant.

  19. SI PC104 Performance Test Report

    SciTech Connect

    Montelongo, S

    2005-12-16

    The Spectral Instruments (SI) PC104 systems associated with the SI-1000 CCD camera exhibited intermittent power problems during setup, test and operations which called for further evaluation and testing. The SI PC104 System is the interface between the SI-1000 CCD camera and its associated Diagnostic Controller (DC). As such, the SI PC104 must be a reliable, robust system capable of providing consistent performance in various configurations and operating conditions. This SI PC104 system consists of a stackable set of modules designed to meet the PC104+ Industry Standard. The SI PC104 System consists of a CPU module, SI Camera card, Media converter card, Video card and a I/O module. The root cause of power problems was identified as failing solder joints at the LEMO power connector attached to the SI Camera Card. The recommended solution was to provide power to the PC104 system via a PC104+ power supply module configured into the PC104 stack instead of thru the LEMO power connector. Test plans (2) were developed to test SI PC104 performance and identify any outstanding issues noted during extended operations. Test Plan 1 included performance and image acquisition tests. Test Plan 2 verified performance after implementing recommendations. Test Plan 2 also included verifying integrity of system files and driver installation after bootup. Each test plan was implemented to fully test against each set of problems noted. Test Plan presentations and Test Plan results are attached as appendices. Anticipated test results will show successful operation and reliable performance of the SI PC104 system receiving its power via a PC104 power supply module. A SI PC104 Usage Recommendation Memo will be sent out to the SI PC104 User Community. Recommendation memo(s) are attached as appendices.

  20. Automatic functional analysis of left ventricle in cardiac cine MRI

    PubMed Central

    Lu, Ying-Li; Connelly, Kim A.; Dick, Alexander J.; Wright, Graham A.

    2013-01-01

    Rationale and objectives A fully automated left ventricle segmentation method for the functional analysis of cine short axis (SAX) magnetic resonance (MR) images was developed, and its performance evaluated with 133 studies of subjects with diverse pathology: ischemic heart failure (n=34), non-ischemic heart failure (n=30), hypertrophy (n=32), and healthy (n=37). Materials and methods The proposed automatic method locates the left ventricle (LV), then for each image detects the contours of the endocardium, epicardium, papillary muscles and trabeculations. Manually and automatically determined contours and functional parameters were compared quantitatively. Results There was no significant difference between automatically and manually determined end systolic volume (ESV), end diastolic volume (EDV), ejection fraction (EF) and left ventricular mass (LVM) for each of the four groups (paired sample t-test, α=0.05). The automatically determined functional parameters showed high correlations with those derived from manual contours, and the Bland-Altman analysis biases were small (1.51 mL, 1.69 mL, –0.02%, –0.66 g for ESV, EDV, EF and LVM, respectively). Conclusions The proposed technique automatically and rapidly detects endocardial, epicardial, papillary muscles’ and trabeculations’ contours providing accurate and reproducible quantitative MRI parameters, including LV mass and EF. PMID:24040616

  1. Photodegradation activity of polyvinyl chloride (PVC)-perchlorinated iron (II) phthalocyanine (FePcCl16) composite film.

    PubMed

    Yang, Changjun; Ye, Liqun; Tian, Lihong; Peng, Tianyou; Deng, Kejian; Zan, Ling

    2011-01-15

    In this paper, a novel kind of photodegradable PVC-FePcCl(16) composite film was prepared by homogeneous embedding FePcCl(16) into the commercial PVC plastic. The photodegradation performance of as-prepared film has been investigated in the ambient air under UV light irradiation by means of weight loss monitoring, FT-IR spectroscopy, UV-Vis spectroscopy. In comparison with the pure PVC film, higher weight loss rate, increasing carbonyl peak intensity and accelerating dehydrochlorination were observed. These results indicate that the PVC-FePcCl(16) composite film has a higher photodegradation activity owing to the FePcCl(16). Moreover, FePcCl(16) has good photostability in the photoreaction. The possible photodegradation mechanism of PVC-FePcCl(16) composite film was also discussed.

  2. AMPS/PC - AUTOMATIC MANUFACTURING PROGRAMMING SYSTEM

    NASA Technical Reports Server (NTRS)

    Schroer, B. J.

    1994-01-01

    The AMPS/PC system is a simulation tool designed to aid the user in defining the specifications of a manufacturing environment and then automatically writing code for the target simulation language, GPSS/PC. The domain of problems that AMPS/PC can simulate are manufacturing assembly lines with subassembly lines and manufacturing cells. The user defines the problem domain by responding to the questions from the interface program. Based on the responses, the interface program creates an internal problem specification file. This file includes the manufacturing process network flow and the attributes for all stations, cells, and stock points. AMPS then uses the problem specification file as input for the automatic code generator program to produce a simulation program in the target language GPSS. The output of the generator program is the source code of the corresponding GPSS/PC simulation program. The system runs entirely on an IBM PC running PC DOS Version 2.0 or higher and is written in Turbo Pascal Version 4 requiring 640K memory and one 360K disk drive. To execute the GPSS program, the PC must have resident the GPSS/PC System Version 2.0 from Minuteman Software. The AMPS/PC program was developed in 1988.

  3. 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.

  4. PC-based fault finder

    SciTech Connect

    Bengiamin, N.N. ); Jensen, C.A. . Electrical Engineering Dept. Otter Tail Power Co., Fergus Falls, MN . System Protection Group); McMahon, H. )

    1993-07-01

    Electric utilities are continually pressed to stay competitive while meeting the increasing demand of today's sophisticated customer. Advances in electron equipment and the improved array of electric driven devices are setting new standards for improved reliability and quality of service. Besides the specifications on voltage and frequency regulation and the permitted harmonic content, to name a few, the number and duration of service interruptions have a dramatic direct effect on the customer. Accurate fault locating reduces transmission line patrolling and is of particular significance in repairing long lines in rough terrain. Shortened outage times, reduced equipment degrading and stress on the system, fast restored service, and improved revenue are immediate outcomes of fast fault locating which insure minimum loss of system security. This article focuses on a PC-based (DOS) computer program that has unique features for identifying the type of fault and its location on overhead transmission/distribution lines. Balanced and unbalanced faults are identified and located accurately while accounting for changes in conductor sizes and network configuration. The presented concepts and methodologies have been spurred by Otter Tail Power's need for an accurate fault locating scheme to accommodate multiple feeders with mixed lone configurations. A case study based on a section of the Otter Tail network is presented to illustrate the features and capabilities of the developed software.

  5. Automatic evaluation of the Valsalva sinuses from cine-MRI

    NASA Astrophysics Data System (ADS)

    Blanchard, Cédric; Sliwa, Tadeusz; Lalande, Alain; Mohan, Pauliah; Bouchot, Olivier; Voisin, Yvon

    2011-03-01

    MRI appears to be particularly attractive for the study of the Sinuses of Valsalva (SV), however there is no global consensus on their suitable measurements. In this paper, we propose a new method, based on the mathematical morphology and combining a numerical geodesic reconstruction with an area estimation, to automatically evaluate the SV from a cine-MRI in a cross-sectional orientation. It consists in the extraction of the shape of the SV, the detection of relevant points (commissures, cusps and the centre of the SV), the measurement of relevant distances and in a classification of the valve as bicuspid or tricuspid by a metric evaluation of the SV. Our method was tested on 23 patient examinations and radii calculations were compared with a manual measurement. The classification of the valve as tricuspid or bicuspid was correct for all the cases. Moreover, there are an excellent correlation and an excellent concordance between manual and automatic measurements for images at diastolic phase (r= 0.97; y = x - 0.02; p=NS; mean of differences = -0.1 mm; standard deviation of differences = 2.3 mm) and at systolic phase (r= 0.96; y = 0.97 x + 0.80; p=NS ; mean of differences = -0.1 mm; standard deviation of differences = 2.4 mm). The cross-sectional orientation of the image acquisition plane conjugated with our automatic method provides a reliable morphometric evaluation of the SV, based on the automatic location of the centre of the SV, the commissure and the cusp positions. Measurements of distances between relevant points allow a precise evaluation of the SV.

  6. Single breath hold 3D cardiac cine MRI using kat-ARC: preliminary results at 1.5T.

    PubMed

    Jeong, Daniel; Schiebler, Mark L; Lai, Peng; Wang, Kang; Vigen, Karl K; François, Christopher J

    2015-04-01

    Validation of a new single breath-hold, three-dimensional, cine balanced steady-state free precession (3D cine bSSFP) cardiac magnetic resonance (CMR) sequence for left ventricular function. CMR examinations were performed on fifteen patients and three healthy volunteers on a clinical 1.5T scanner using a two-dimensional (2D) cine balanced SSFP CMR sequence (2D cine bSSFP) followed by an investigational 3D cine bSSFP pulse sequence acquired within a single breath hold. Left ventricular end diastolic volume (LVEDV), end systolic volume (LVESV), ejection fraction (LVEF), and myocardial mass were independently segmented on a workstation by two experienced radiologists. Blood pool to myocardial contrast was evaluated in consensus using a Likert scale. Bland-Altman analysis was used to compare these quantitative and nominal measurements for the two sequences. The average acquisition time was significantly shorter for the 3D cine bSSFP than for 2D cine bSSFP (0.36 ± 0.03 vs. 8.5 ± 2.3 min) p = 0.0002. Bland-Altman analyses [bias and (limits of agreement)] of the data derived from these two methods revealed that the LVEF 0.9% (-4.7, 6.4), LVEDV 4.9 ml (-23.0, 32.8), LVESV -0.2 ml (-22.4, 21.9), and myocardial mass -0.4 g (-23.8, 23.0) were not significantly different. There was excellent intraclass correlation for intra-observer variability (0.981, 0.989, 0.997, 0.985) and inter-observer variability (0.903, 0.954, 0.970, 0.842) for LVEF, LVEDV, LVESV, and myocardial mass respectively. 3D cine bSSFP allows for accurate single breath-hold volumetric cine CMR which enables substantial improvements in scanner time efficiency without sacrificing diagnostic accuracy.

  7. Tissue-Point Motion Tracking in the Tongue from Cine MRI and Tagged MRI

    ERIC Educational Resources Information Center

    Woo, Jonghye; Stone, Maureen; Suo, Yuanming; Murano, Emi Z.; Prince, Jerry L.

    2014-01-01

    Purpose: Accurate tissue motion tracking within the tongue can help professionals diagnose and treat vocal tract--related disorders, evaluate speech quality before and after surgery, and conduct various scientific studies. The authors compared tissue tracking results from 4 widely used deformable registration (DR) methods applied to cine magnetic…

  8. Analysis of 3-D Tongue Motion from Tagged and Cine Magnetic Resonance Images

    ERIC Educational Resources Information Center

    Xing, Fangxu; Woo, Jonghye; Lee, Junghoon; Murano, Emi Z.; Stone, Maureen; Prince, Jerry L.

    2016-01-01

    Purpose: Measuring tongue deformation and internal muscle motion during speech has been a challenging task because the tongue deforms in 3 dimensions, contains interdigitated muscles, and is largely hidden within the vocal tract. In this article, a new method is proposed to analyze tagged and cine magnetic resonance images of the tongue during…

  9. Assessment of Bladder Motion for Clinical Radiotherapy Practice Using Cine-Magnetic Resonance Imaging

    SciTech Connect

    McBain, Catherine A.; Khoo, Vincent S.; Buckley, David L.; Sykes, Jonathan S.; Green, Melanie M.; Cowan, Richard A.; Hutchinson, Charles E.; Moore, Christopher J.; Price, Patricia M.

    2009-11-01

    Purpose: Organ motion is recognized as the principal source of inaccuracy in bladder radiotherapy (RT), but there is currently little information on intrafraction bladder motion. Methods and Materials: We used cine-magnetic resonance imaging (cine-MRI) to study bladder motion relevant to intrafraction RT delivery. On two occasions, a 28 minute cine-MRI sequence was acquired from 10 bladder cancer patients and 5 control participants immediately after bladder emptying, after abstinence from drinking for the preceding hour. From the resulting cine sequences, bladder motion was subjectively assessed. To quantify bladder motion, the bladder was contoured in imaging volume sets at 0, 14, and 28 min to measure changes to bladder volumes, wall displacements, and center of gravity (COG) over time. Results: The dominant source of bladder motion during imaging was bladder filling (up to 101% volume increase); rectal and small bowel movements were transient, with minimal impact. Bladder volume changes were similar for all participants. However for bladder cancer patients, wall displacements were larger (up to 58 mm), less symmetrical, and more variable compared with nondiseased control bladders. Conclusions: Significant and individualized intrafraction bladder wall displacements may occur during bladder RT delivery. This important source of inaccuracy should be incorporated into treatment planning and verification.

  10. Evaluation of congenital heart disease by cine magnetic resonance imaging (MRI)

    SciTech Connect

    Feiglin, D.H.I.; Moodie, D.S.; O'Donnell, J.K.; Go, R.T.; Sterba, R.; MacIntyre, W.J.

    1985-05-01

    The authors studied 11 adult patients (pts) with atrial septal defect (ASD) and 4 adult pts with ventricular septal defect (VSD) using cine magnetic resonance. All studies were performed using a .6T superconducting magnet with ECG gating and electronic axial rotation when appropriate. Repeated multislice image with no change in physiologic delay of the spin echo pulse sequence, but varying the time by offsetting one slice at each imaging stage allowed for an N x N collection of data where N is the number of slices in one collection set and is equal to the number of sets collected. Algebraic manipulation of the T1 weighted images (TE=30mSec TRcine dynamic display. This technique provides multitime views of each slice and allows for greater appreciation of right atrial enlargement, right ventricular hypertrophy and dilation, and imaging of the atrial septum than does conventional MRI. Using this technique, the authors have identified both atrial and ventricular septal defects in all pts preoperatively and have noted an intact atrial septum following surgery. Standard MRI produced 4 false positive studies postoperatively because only 1 phase of the cardiac cycle was reviewed. Cine MRI allows better identification of septal defects than standard static acquisitions. The cine technique also provides better definition and delineation of right sided abnormalities which are maximized when viewed in a cardiac major axis obtained by electronic axial rotation.

  11. Motion prediction in MRI-guided radiotherapy based on interleaved orthogonal cine-MRI

    NASA Astrophysics Data System (ADS)

    Seregni, M.; Paganelli, C.; Lee, D.; Greer, P. B.; Baroni, G.; Keall, P. J.; Riboldi, M.

    2016-01-01

    In-room cine-MRI guidance can provide non-invasive target localization during radiotherapy treatment. However, in order to cope with finite imaging frequency and system latencies between target localization and dose delivery, tumour motion prediction is required. This work proposes a framework for motion prediction dedicated to cine-MRI guidance, aiming at quantifying the geometric uncertainties introduced by this process for both tumour tracking and beam gating. The tumour position, identified through scale invariant features detected in cine-MRI slices, is estimated at high-frequency (25 Hz) using three independent predictors, one for each anatomical coordinate. Linear extrapolation, auto-regressive and support vector machine algorithms are compared against systems that use no prediction or surrogate-based motion estimation. Geometric uncertainties are reported as a function of image acquisition period and system latency. Average results show that the tracking error RMS can be decreased down to a [0.2; 1.2] mm range, for acquisition periods between 250 and 750 ms and system latencies between 50 and 300 ms. Except for the linear extrapolator, tracking and gating prediction errors were, on average, lower than those measured for surrogate-based motion estimation. This finding suggests that cine-MRI guidance, combined with appropriate prediction algorithms, could relevantly decrease geometric uncertainties in motion compensated treatments.

  12. A feasibility study of treatment verification using EPID cine images for hypofractionated lung radiotherapy

    NASA Astrophysics Data System (ADS)

    Tang, Xiaoli; Lin, Tong; Jiang, Steve

    2009-09-01

    We propose a novel approach for potential online treatment verification using cine EPID (electronic portal imaging device) images for hypofractionated lung radiotherapy based on a machine learning algorithm. Hypofractionated radiotherapy requires high precision. It is essential to effectively monitor the target to ensure that the tumor is within the beam aperture. We modeled the treatment verification problem as a two-class classification problem and applied an artificial neural network (ANN) to classify the cine EPID images acquired during the treatment into corresponding classes—with the tumor inside or outside of the beam aperture. Training samples were generated for the ANN using digitally reconstructed radiographs (DRRs) with artificially added shifts in the tumor location—to simulate cine EPID images with different tumor locations. Principal component analysis (PCA) was used to reduce the dimensionality of the training samples and cine EPID images acquired during the treatment. The proposed treatment verification algorithm was tested on five hypofractionated lung patients in a retrospective fashion. On average, our proposed algorithm achieved a 98.0% classification accuracy, a 97.6% recall rate and a 99.7% precision rate. This work was first presented at the Seventh International Conference on Machine Learning and Applications, San Diego, CA, USA, 11-13 December 2008.

  13. Motion prediction in MRI-guided radiotherapy based on interleaved orthogonal cine-MRI.

    PubMed

    Seregni, M; Paganelli, C; Lee, D; Greer, P B; Baroni, G; Keall, P J; Riboldi, M

    2016-01-21

    In-room cine-MRI guidance can provide non-invasive target localization during radiotherapy treatment. However, in order to cope with finite imaging frequency and system latencies between target localization and dose delivery, tumour motion prediction is required. This work proposes a framework for motion prediction dedicated to cine-MRI guidance, aiming at quantifying the geometric uncertainties introduced by this process for both tumour tracking and beam gating. The tumour position, identified through scale invariant features detected in cine-MRI slices, is estimated at high-frequency (25 Hz) using three independent predictors, one for each anatomical coordinate. Linear extrapolation, auto-regressive and support vector machine algorithms are compared against systems that use no prediction or surrogate-based motion estimation. Geometric uncertainties are reported as a function of image acquisition period and system latency. Average results show that the tracking error RMS can be decreased down to a [0.2; 1.2] mm range, for acquisition periods between 250 and 750 ms and system latencies between 50 and 300 ms. Except for the linear extrapolator, tracking and gating prediction errors were, on average, lower than those measured for surrogate-based motion estimation. This finding suggests that cine-MRI guidance, combined with appropriate prediction algorithms, could relevantly decrease geometric uncertainties in motion compensated treatments.

  14. Scale-PC shielding analysis sequences

    SciTech Connect

    Bowman, S.M.

    1996-05-01

    The SCALE computational system is a modular code system for analyses of nuclear fuel facility and package designs. With the release of SCALE-PC Version 4.3, the radiation shielding analysis community now has the capability to execute the SCALE shielding analysis sequences contained in the control modules SAS1, SAS2, SAS3, and SAS4 on a MS- DOS personal computer (PC). In addition, SCALE-PC includes two new sequences, QADS and ORIGEN-ARP. The capabilities of each sequence are presented, along with example applications.

  15. cine-Substitution reactions of metallabenzenes: an experimental and computational study.

    PubMed

    Wang, Tongdao; Zhang, Hong; Han, Feifei; Long, Lipeng; Lin, Zhenyang; Xia, Haiping

    2013-08-12

    Alkali-resistant osmabenzene [(SCN)2(PPh3)2Os{CHC(PPh3)CHCICH}] (2) can undergo nucleophilic aromatic substitution with MeOH or EtOH to give cine-substitution products [(SCN)2(PPh3)2Os{CHC(PPh3)CHCHCR}] (R=OMe (3), OEt(4)) in the presence of strong alkali. However, the reactions of compound 2 with various amines, such as n-butylamine and aniline, afford five-membered ring species, [(SCN)2(PPh3)2Os{CH=C(PPh3)CH=C(CH=NHR')}] (R'=nBu(8), Ph(9)), in addition to the desired cine-substitution products, [(SCN)2(PPh3)2Os{CHC(PPh3)CHCHC(NHR')}] (R'=nBu(6), Ph(7)), under similar reaction conditions. The mechanisms of these reactions have been investigated in detail with the aid of isotopic labeling experiments and density functional theory (DFT) calculations. The results reveal that the cine-substitution reactions occur through nucleophilic addition, dissociation of the leaving group, protonation, and deprotonation steps, which resemble the classical "addition-of-nucleophile, ring-opening, ring-closure" (ANRORC) mechanism. DFT calculations suggest that, in the reaction with MeOH, the formation of a five-membered metallacycle species is both kinetically and thermodynamically less favorable, which is consistent with the experimental results that only the cine-substitution product is observed. For the analogous reaction with n-butylamine, the pathway for the formation of the cine-substitution product is kinetically less favorable than the pathway for the formation of a five-membered ring species, but is much more thermodynamically favorable, again consistent with the experimental conversion of compound 8 into compound 6, which is observed in an in situ NMR experiment with an isolated pure sample of 8.

  16. DIGLIB. PC-DOS Graphics Subroutine Library

    SciTech Connect

    Burleson, R.R.

    1989-02-01

    DIGLIB is a collection of general graphics subroutines. It was designed to be small, reasonably fast, device-independent, and compatible with DEC-supplied operating systems for VAXes, PDP-11s, and LSI-11s, and the DOS operating system for IBM PCs and IBM-compatible machines. DIGLIB/PC runs on IBM PCs under PC-DOS or MS-DOS. The software is readily usable by casual programmers for two-dimensional plotting.

  17. Cine-MRI versus two-dimensional echocardiography to measure in vivo left ventricular function in rat heart.

    PubMed

    Stuckey, Daniel J; Carr, Carolyn A; Tyler, Damian J; Clarke, Kieran

    2008-08-01

    Two-dimensional echocardiography is the most commonly used non-invasive method for measuring in vivo cardiac function in experimental animals. In humans, measurements of cardiac function made using cine-MRI compare favourably with those made using echocardiography. However, no rigorous comparison has been made in small animals. Here, standard short-axis two-dimensional (2D) echocardiography (2D-echo) and cine-MRI measurements were made in the same rats, both control and after chronic myocardial infarction. Correlations between the two techniques were found for end diastolic area, stroke area and ejection fraction, but cine-MRI measurements of ejection fraction were 12+/-6% higher than those made using 2D-echo, because of the 1.8-fold higher temporal resolution of the MRI technique (4.6 ms vs 8.3 ms). Repeated measurements on the same group of rats over several days showed that the cine-MRI technique was more reproducible than 2D-echo, in that 2D-echo would require five times more animals to find a statistically significant difference. In summary, caution should be exercised when comparing functional results acquired using short-axis 2D-echo vs cine-MRI. The accuracy of cine-MRI allows identification of alterations in heart function that may be missed when using 2D-echo.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Adapting PC104Plus for Space

    NASA Technical Reports Server (NTRS)

    Abbott, Larry; Cox, Gary; Nguyen, Hai

    2000-01-01

    This article addresses the issues associated with adapting the commercial PC104Plus standard and its associated architecture to the requirements of space applications. In general, space applications exhibit extreme constraints on power, weight, and volume. EMI and EMC are also issues of significant concern. Additionally, space applications have to survive high radiation environment. Finally, NASA is always concerned about achieving cost effective solutions that are compatible with safety and launch constraints. Weight and volume constraints are directly related to high launch cost. Power on the other hand is not only related to the high launch costs, but are related to the problem of dissipating the resulting heat once in space. The article addresses why PC104Plus is an appropriate solution for the weight and volume issues. The article also addresses what NASA did electrically to reduce power consumption and mechanically dissipate the associated heat in a microgravity and vacuum environment, and how these solutions allow NASA to integrate various sizes of ruggedized custom PC104 boards with COTS, PC104 complaint boards for space applications. In addition to the mechanical changes to deal with thermal dissipation NASA also made changes to minimize EMI. Finally, radiation issues are addressed as well as the architectural and testing solutions and the implications for use of COTS PC104Plus boards.

  4. Development of a transgenic early flowering pear (Pyrus communis L.) genotype by RNAi silencing of PcTFL1-1 and PcTFL1-2.

    PubMed

    Freiman, Aviad; Shlizerman, Lyudmila; Golobovitch, Sara; Yablovitz, Zeev; Korchinsky, Raia; Cohen, Yuval; Samach, Alon; Chevreau, Elisabeth; Le Roux, Pierre-Marie; Patocchi, Andrea; Flaishman, Moshe A

    2012-06-01

    Trees require a long maturation period, known as juvenile phase, before they can reproduce, complicating their genetic improvement as compared to annual plants. 'Spadona', one of the most important European pear (Pyrus communis L.) cultivars grown in Israel, has a very long juvenile period, up to 14 years, making breeding programs extremely slow. Progress in understanding the molecular basis of the transition to flowering has revealed genes that accelerate reproductive development when ectopically expressed in transgenic plants. A transgenic line of 'Spadona', named Early Flowering-Spadona (EF-Spa), was produced using a MdTFL1 RNAi cassette targeting the native pear genes PcTFL1-1 and PcTFL1-2. The transgenic line had three T-DNA insertions, one assigned to chromosome 2 and two to chromosome 14 PcTFL1-1 and PcTFL1-2 were completely silenced, and EF-Spa displayed an early flowering phenotype: flowers developed already in tissue culture and on most rooted plants 1-8 months after transfer to the greenhouse. EF-Spa developed solitary flowers from apical or lateral buds, reducing vegetative growth vigor. Pollination of EF-Spa trees generated normal-shaped fruits with viable F1 seeds. The greenhouse-grown transgenic F1 seedlings formed shoots and produced flowers 1-33 months after germination. Sequence analyses, of the non-transgenic F1 seedlings, demonstrated that this approach can be used to recover seedlings that have no trace of the T-DNA. Thus, the early flowering transgenic line EF-Spa obtained by PcTFL1 silencing provides an interesting tool to accelerate pear breeding.

  5. TH-A-BRF-04: Intra-Fraction Motion Characterization for Early Stage Rectal Cancer Using Cine-MRI

    SciTech Connect

    Kleijnen, J; Asselen, B; Burbach, M; Intven, M; Reerink, O; Philippens, M; Lagendijk, J; Raaymakers, B

    2014-06-15

    Purpose: To investigate the intra-fraction motion in patients with early stage rectal cancer using cine-MRI. Methods: Sixteen patient diagnosed with early stage rectal cancer underwent 1.5 T MR imaging prior to each treatment fraction of their short course radiotherapy (n=76). During each scan session, three 2D sagittal cine-MRIs were performed: at the beginning (Start), after 9:30 minutes (Mid), and after 18 minutes (End). Each cine-MRI has a duration of one minute at 2Hz temporal resolution, resulting in a total of 3:48 hours of cine-MRI. Additionally, standard T2-weighted (T2w) imaging was performed. Clinical target volume (CTV) an tumor (GTV) were delineated on the T2w scan and transferred to the first time-point of each cine-MRI scan. Within each cine-MRI, the first frame was registered to the remaining frames of the scan, using a non-rigid B-spline registration. To investigate potential drifts, a similar registration was performed between the first frame of the Start and End scans.To evaluate the motion, the distances by which the edge pixels of the delineations move in anterior-posterior (AP) and cranial-caudal (CC) direction, were determined using the deformation field of the registrations. The distance which incorporated 95% of these edge pixels (dist95%) was determined within each cine-MRI, and between Start- End scans, respectively. Results: Within a cine-MRI, we observed an average dist95% for the CTV of 1.3mm/1.5mm (SD=0.7mm/0.6mm) and for the GTV of 1.2mm/1.5mm (SD=0.8mm/0.9mm), in respectively AP/CC. For the CTV motion between the Start and End scan, an average dist95% of 5.5mm/5.3mm (SD=3.1mm/2.5mm) was found, in respectively AP/CC. For the GTV motion, an average dist95% of 3.6mm/3.9mm (SD=2.2mm/2.5mm) was found in AP/CC, respectively. Conclusion: Although intra-fraction motion within a one minute cine-MRI is limited, substantial intra-fraction motion was observed within the 18 minute time period between the Start and End cine-MRI.

  6. Fast cine-magnetic resonance imaging point tracking for prostate cancer radiation therapy planning

    NASA Astrophysics Data System (ADS)

    Dowling, J.; Dang, K.; Fox, Chris D.; Chandra, S.; Gill, Suki; Kron, T.; Pham, D.; Foroudi, F.

    2014-03-01

    The analysis of intra-fraction organ motion is important for improving the precision of radiation therapy treatment delivery. One method to quantify this motion is for one or more observers to manually identify anatomic points of interest (POIs) on each slice of a cine-MRI sequence. However this is labour intensive and inter- and intra- observer variation can introduce uncertainty. In this paper a fast method for non-rigid registration based point tracking in cine-MRI sagittal and coronal series is described which identifies POIs in 0.98 seconds per sagittal slice and 1.35 seconds per coronal slice. The manual and automatic points were highly correlated (r>0.99, p<0.001) for all organs and the difference generally less than 1mm. For prostate planning peristalsis and rectal gas can result in unpredictable out of plane motion, suggesting the results may require manual verification.

  7. Broad spectral sensitivity and improved efficiency in CuPc/Sub-Pc organic photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Kumar, Hemant; Kumar, Pankaj; Bhardwaj, Ramil; Sharma, G. D.; Chand, Suresh; Jain, S. C.; Kumar, Vikram

    2009-01-01

    We demonstrate organic photovoltaic devices incorporating two donors, namely, copper phthalocyanine (CuPc) and boron sub-phthalocyanine chloride (Sub-Pc) in association with single acceptor fullerene (C60) with sensitivity extending across the visible solar spectrum. It has been found that the absorption in different spectral regions in CuPc and Sub-Pc results in efficient harvesting of incident light photons which leads to enhanced power conversion efficiency (η). An enhancement in η from 0.64%, in the device architecture indium-tin-oxide (ITO)/CuPc(20 nm)/C60(40 nm)/bathophenanthroline (BPhen) (8 nm)/Al(150 nm), to ~1.3% in the optimized device having a 2 nm layer of Sub-Pc in the geometry ITO/CuPc(18 nm)/Sub-Pc(2 nm)/C60 (40 nm)/BPhen (8 nm)/Al(150 nm) has been observed. This enhancement in η is dominantly attributed to the increment in short circuit current density (Jsc) due to efficient photon harvesting by incorporation of dual donors.

  8. The IBM PC at NASA Ames

    NASA Technical Reports Server (NTRS)

    Peredo, James P.

    1988-01-01

    Like many large companies, Ames relies very much on its computing power to get work done. And, like many other large companies, finding the IBM PC a reliable tool, Ames uses it for many of the same types of functions as other companies. Presentation and clarification needs demand much of graphics packages. Programming and text editing needs require simpler, more-powerful packages. The storage space needed by NASA's scientists and users for the monumental amounts of data that Ames needs to keep demand the best database packages that are large and easy to use. Availability to the Micom Switching Network combines the powers of the IBM PC with the capabilities of other computers and mainframes and allows users to communicate electronically. These four primary capabilities of the PC are vital to the needs of NASA's users and help to continue and support the vast amounts of work done by the NASA employees.

  9. Peak Pc Prediction in Conjunction Analysis: Conjunction Assessment Risk Analysis. Pc Behavior Prediction Models

    NASA Technical Reports Server (NTRS)

    Vallejo, J.J.; Hejduk, M.D.; Stamey, J. D.

    2015-01-01

    Satellite conjunction risk typically evaluated through the probability of collision (Pc). Considers both conjunction geometry and uncertainties in both state estimates. Conjunction events initially discovered through Joint Space Operations Center (JSpOC) screenings, usually seven days before Time of Closest Approach (TCA). However, JSpOC continues to track objects and issue conjunction updates. Changes in state estimate and reduced propagation time cause Pc to change as event develops. These changes a combination of potentially predictable development and unpredictable changes in state estimate covariance. Operationally useful datum: the peak Pc. If it can reasonably be inferred that the peak Pc value has passed, then risk assessment can be conducted against this peak value. If this value is below remediation level, then event intensity can be relaxed. Can the peak Pc location be reasonably predicted?

  10. Machine learning for the automatic localisation of foetal body parts in cine-MRI scans

    NASA Astrophysics Data System (ADS)

    Bowles, Christopher; Nowlan, Niamh C.; Hayat, Tayyib T. A.; Malamateniou, Christina; Rutherford, Mary; Hajnal, Joseph V.; Rueckert, Daniel; Kainz, Bernhard

    2015-03-01

    Being able to automate the location of individual foetal body parts has the potential to dramatically reduce the work required to analyse time resolved foetal Magnetic Resonance Imaging (cine-MRI) scans, for example, for use in the automatic evaluation of the foetal development. Currently, manual preprocessing of every scan is required to locate body parts before analysis can be performed, leading to a significant time overhead. With the volume of scans becoming available set to increase as cine-MRI scans become more prevalent in clinical practice, this stage of manual preprocessing is a bottleneck, limiting the data available for further analysis. Any tools which can automate this process will therefore save many hours of research time and increase the rate of new discoveries in what is a key area in understanding early human development. Here we present a series of techniques which can be applied to foetal cine-MRI scans in order to first locate and then differentiate between individual body parts. A novel approach to maternal movement suppression and segmentation using Fourier transforms is put forward as a preprocessing step, allowing for easy extraction of short movements of individual foetal body parts via the clustering of optical flow vector fields. These body part movements are compared to a labelled database and probabilistically classified before being spatially and temporally combined to give a final estimate for the location of each body part.

  11. Acceleration Studies

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.

    1993-01-01

    Work to support the NASA MSFC Acceleration Characterization and Analysis Project (ACAP) was performed. Four tasks (analysis development, analysis research, analysis documentation, and acceleration analysis) were addressed by parallel projects. Work concentrated on preparation for and implementation of near real-time SAMS data analysis during the USMP-1 mission. User support documents and case specific software documentation and tutorials were developed. Information and results were presented to microgravity users. ACAP computer facilities need to be fully implemented and networked, data resources must be cataloged and accessible, future microgravity missions must be coordinated, and continued Orbiter characterization is necessary.

  12. Mathematics Instruction and the Tablet PC

    ERIC Educational Resources Information Center

    Fister, K. Renee; McCarthy, Maeve L.

    2008-01-01

    The use of tablet PCs in teaching is a relatively new phenomenon. A cross between a notebook computer and a personal digital assistant (PDA), the tablet PC has all of the features of a notebook with the additional capability that the screen can also be used for input. Tablet PCs are usually equipped with a stylus that allows the user to write on…

  13. Jargon that Computes: Today's PC Terminology.

    ERIC Educational Resources Information Center

    Crawford, Walt

    1997-01-01

    Discusses PC (personal computer) and telecommunications terminology in context: Integrated Services Digital Network (ISDN); Asymmetric Digital Subscriber Line (ADSL); cable modems; satellite downloads; T1 and T3 lines; magnitudes ("giga-,""nano-"); Central Processing Unit (CPU); Random Access Memory (RAM); Universal Serial Bus…

  14. Multitasking Operating Systems for the IBM PC.

    ERIC Educational Resources Information Center

    Owen, G. Scott

    1985-01-01

    The ability of a microcomputer to execute several programs at the same time is called "multitasking." The nature and use of one multitasking operating system Concurrent PC-DOS from Digital Research (the developers of the CP/M operating system) are discussed. (JN)

  15. Combating adverse selection in secondary PC markets.

    PubMed

    Hickey, Stewart W; Fitzpatrick, Colin

    2008-04-15

    Adverse selection is a significant contributor to market failure in secondary personal computer (PC) markets. Signaling can act as a potential solution to adverse selection and facilitate superior remarketing of second-hand PCs. Signaling is a means whereby usage information can be utilized to enhance consumer perception of both value and utility of used PCs and, therefore, promote lifetime extension for these systems. This can help mitigate a large portion of the environmental impact associated with PC system manufacture. In this paper, the computer buying and selling behavior of consumers is characterized via a survey of 270 Irish residential users. Results confirm the existence of adverse selection in the Irish market with 76% of potential buyers being unwilling to purchase and 45% of potential vendors being unwilling to sell a used PC. The so-called "closet affect" is also apparent with 78% of users storing their PC after use has ceased. Results also indicate that consumers place a higher emphasis on specifications when considering a second-hand purchase. This contradicts their application needs which are predominantly Internet and word-processing/spreadsheet/presentation applications, 88% and 60% respectively. Finally, a market solution utilizing self monitoring and reporting technology (SMART) sensors for the purpose of real time usage monitoring is proposed, that can change consumer attitudes with regard to second-hand computer equipment.

  16. PC Kiosk Trends in Rural India

    ERIC Educational Resources Information Center

    Toyama, Kentaro; Kiri, Karishma; Menon, Deepak; Sethi, Suneet; Pal, Joyojeet; Srinivasan, Janaki

    2006-01-01

    This article presents a series of preliminary, quantitative results on rural PC kiosks in India. An analysis of the data confirms many expected trends and correlations and shows that kiosks still face the challenge of sustainability as a business. This study is based on questionnaires presented to kiosk operators and customers of kiosks operated…

  17. Experience in setting up a PC cluster

    NASA Astrophysics Data System (ADS)

    Lin, Ganghua; Zhang, Mei

    2004-09-01

    In this paper we summary and present our thinking and experience in setting up a PC cluster, with a consideration that the described thinking and experience may be relevant to or useful for those who intend to buy a similar cluster in the near future.

  18. Stretch Your PC Dollars--Buy Clones.

    ERIC Educational Resources Information Center

    True, John

    1986-01-01

    Relates how the story of how San Francisco State University evaluated IBM PC look-alikes, considered some of the risks involved, and decided to purchase over 100 of them. Questions of compatibility, vendor longevity, support, and other risk management issues are discussed. (Author/MLW)

  19. New automatic mode of visualizing the colon via Cine CT

    NASA Astrophysics Data System (ADS)

    Udupa, Jayaram K.; Odhner, Dewey; Eisenberg, Harvey C.

    2001-05-01

    Methods of visualizing the inner colonic wall by using CT images has actively been pursued in recent years in an attempt to eventually replace conventional colonoscopic examination. In spite of impressive progress in this direction, there are still several problems, which need satisfactory solutions. Among these, we address three problems in this paper: segmentation, coverage, and speed of rendering. Instead of thresholding, we utilize the fuzzy connectedness framework to segment the colonic wall. Instead of the endoscopic viewing mode and various mapping techniques, we utilize the central line through the colon to generate automatically viewing directions that are enface with respect to the colon wall, thereby avoiding blind spots in viewing. We utilize some modifications of the ultra fast shell rendering framework to ensure fast rendering speed. The combined effect of these developments is that a colon study requires an initial 5 minutes of operator time plus an additional 5 minutes of computational time and subsequently enface renditions are created in real time (15 frames/sec) on a 1 GHz Pentium PC under the Linux operating system.

  20. Evaluation of potential internal target volume of liver tumors using cine-MRI

    SciTech Connect

    Akino, Yuichi; Oh, Ryoong-Jin; Masai, Norihisa; Shiomi, Hiroya; Inoue, Toshihiko

    2014-11-01

    Purpose: Four-dimensional computed tomography (4DCT) is widely used for evaluating moving tumors, including lung and liver cancers. For patients with unstable respiration, however, the 4DCT may not visualize tumor motion properly. High-speed magnetic resonance imaging (MRI) sequences (cine-MRI) permit direct visualization of respiratory motion of liver tumors without considering radiation dose exposure to patients. Here, the authors demonstrated a technique for evaluating internal target volume (ITV) with consideration of respiratory variation using cine-MRI. Methods: The authors retrospectively evaluated six patients who received stereotactic body radiotherapy (SBRT) to hepatocellular carcinoma. Before acquiring planning CT, sagittal and coronal cine-MRI images were acquired for 30 s with a frame rate of 2 frames/s. The patient immobilization was conducted under the same condition as SBRT. Planning CT images were then acquired within 15 min from cine-MRI image acquisitions, followed by a 4DCT scan. To calculate tumor motion, the motion vectors between two continuous frames of cine-MRI images were calculated for each frame using the pyramidal Lucas–Kanade method. The target contour was delineated on one frame, and each vertex of the contour was shifted and copied onto the following frame using neighboring motion vectors. 3D trajectory data were generated with the centroid of the contours on sagittal and coronal images. To evaluate the accuracy of the tracking method, the motion of clearly visible blood vessel was analyzed with the motion tracking and manual detection techniques. The target volume delineated on the 50% (end-exhale) phase of 4DCT was translated with the trajectory data, and the distribution of the occupancy probability of target volume was calculated as potential ITV (ITV {sub Potential}). The concordance between ITV {sub Potential} and ITV estimated with 4DCT (ITV {sub 4DCT}) was evaluated using the Dice’s similarity coefficient (DSC). Results

  1. 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.

  2. 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.

  3. 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…

  4. 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.

  5. Wf/pc Cycle 1 Cal: Non-Sv PC Flats 1

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This program takes "uniform illuminated" pictures of the earth to obtain the "instrument signature" for flat field corrections. This proposal contains observations for all PC filters used by GOs and GTOs during Cycle 1 which were not included in the SV program. The camera - filter combinations done in this proposal are: PC: F368M,F588N,F631N,F648M,F875M,F1042M These are the PC flats which are not expected to saturate on the bright earth.

  6. The mechanism of lifetime extension due to CuPc injection layer in organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Tutis, Eduard; Berner, Detlef F.; Zuppiroli, Libero

    2004-09-01

    The remarkable effect on lifetime improvement of copper phthalocianine (CuPc) coated indium tin oxide (ITO) anode of organic light emitting diodes (OLED's) is experimentally well approved. Also known are the electrode morphology, with and without CuPc coating, the energy levels of the used materials, important for charge injection and conduction, the carrier mobility etc. Based on this knowledge we suggest the model that explains the mechanism behind the lifetime improvement. We argue that the charge accumulation at the interface between the CuPc and the hole transport layer is responsible for screening out of the electric field variations leading to current density homogenization across the OLED surface. The variation of the injection field, introduced by electrode roughness, is estimated for typical indium tin oxide morphology used in OLED production. Without the CuPc hole injection layer a substantial current channeling occurs in OLED's, leading to accelerated device degradation.

  7. Particle Accelerators in China

    NASA Astrophysics Data System (ADS)

    Zhang, Chuang; Fang, Shouxian

    As the special machines that can accelerate charged particle beams to high energy by using electromagnetic fields, particle accelerators have been widely applied in scientific research and various areas of society. The development of particle accelerators in China started in the early 1950s. After a brief review of the history of accelerators, this article describes in the following sections: particle colliders, heavy-ion accelerators, high-intensity proton accelerators, accelerator-based light sources, pulsed power accelerators, small scale accelerators, accelerators for applications, accelerator technology development and advanced accelerator concepts. The prospects of particle accelerators in China are also presented.

  8. 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).

  9. PC1/3, PC2 and PC5/6A are targeted to dense core secretory granules by a common mechanism.

    PubMed

    Dikeakos, Jimmy D; Mercure, Chantal; Lacombe, Marie-Josée; Seidah, Nabil G; Reudelhuber, Timothy L

    2007-08-01

    There are seven members of the proprotein convertase (PC) family of secreted serine proteases that cleave their substrates at basic amino acids, thereby activating a variety of hormones, growth factors, and viruses. PC1/3, PC2 and PC5/6A are the only members of the PC family that are targeted to dense core secretory granules, where they carry out the processing of proteins that are secreted from the cell in a regulated manner. Previous studies have identified alpha-helices in the C-termini of the PC1/3 and PC2 proteases that are required for this subcellular targeting. In the current study, we demonstrate that a predicted alpha-helix in the C-terminus of PC5/6A is also critical for the ability of this domain to target a heterologous protein to the regulated secretory pathway of mouse endocrine AtT-20 cells. Analysis of the subcellular distribution of fusion proteins containing the C-terminal domains of PC1/3, PC2 and PC5/6A confirmed that all three domains have the capacity to redirect a constitutively secreted protein to the granule-containing cytoplasmic extensions. Analysis of the predicted structures formed by these three granule-sorting helices shows a correlation between their granule-sorting efficiency and the clustering of hydrophobic amino acids in their granule-targeting helices.

  10. Laser acceleration

    NASA Astrophysics Data System (ADS)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  11. 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].

  12. PC12 differentiation on biopolymer nanostructures

    NASA Astrophysics Data System (ADS)

    Cecchini, Marco; Bumma, Giorgia; Serresi, Michela; Beltram, Fabio

    2007-12-01

    The study of nervous system regeneration and axonal outgrowth control are relevant in several research areas, like neurophysiology or biomedical engineering. Among the elements that control neuron dynamics, the host substrate topography is a key parameter in determining cell differentiation. We present time-lapse experiments to analyze the differentiation dynamics of PC12 cells on nanopatterned biocompatible substrates. 200 nm depth gratings were fabricated on tissue-culture polystyrene substrates by nanoimprint lithography; different linewidths and pitches were compared down to 500 nm and 1000 nm, respectively. PC12 cells were cultured on these substrates and, following NGF administration to the medium, body morphology, cell movement and neuritogenesis were monitored at different time periods. In addition to demonstrating guided differentiation, our studies show complex time variations in body morphology and axon length, and guided cell movement. We show unstable synaptic connections and cell-body polarization, and the competition between topographical guidance and cell-cell interactions.

  13. IBM PC enhances the world's future

    NASA Technical Reports Server (NTRS)

    Cox, Jozelle

    1988-01-01

    Although the purpose of this research is to illustrate the importance of computers to the public, particularly the IBM PC, present examinations will include computers developed before the IBM PC was brought into use. IBM, as well as other computing facilities, began serving the public years ago, and is continuing to find ways to enhance the existence of man. With new developments in supercomputers like the Cray-2, and the recent advances in artificial intelligence programming, the human race is gaining knowledge at a rapid pace. All have benefited from the development of computers in the world; not only have they brought new assets to life, but have made life more and more of a challenge everyday.

  14. A PC based fault diagnosis expert system

    NASA Technical Reports Server (NTRS)

    Marsh, Christopher A.

    1990-01-01

    The Integrated Status Assessment (ISA) prototype expert system performs system level fault diagnosis using rules and models created by the user. The ISA evolved from concepts to a stand-alone demonstration prototype using OPS5 on a LISP Machine. The LISP based prototype was rewritten in C and the C Language Integrated Production System (CLIPS) to run on a Personal Computer (PC) and a graphics workstation. The ISA prototype has been used to demonstrate fault diagnosis functions of Space Station Freedom's Operation Management System (OMS). This paper describes the development of the ISA prototype from early concepts to the current PC/workstation version used today and describes future areas of development for the prototype.

  15. Virtual Reality at the PC Level

    NASA Technical Reports Server (NTRS)

    Dean, John

    1998-01-01

    The main objective of my research has been to incorporate virtual reality at the desktop level; i.e., create virtual reality software that can be run fairly inexpensively on standard PC's. The standard language used for virtual reality on PC's is VRML (Virtual Reality Modeling Language). It is a new language so it is still undergoing a lot of changes. VRML 1.0 came out only a couple years ago and VRML 2.0 came out around last September. VRML is an interpreted language that is run by a web browser plug-in. It is fairly flexible in terms of allowing you to create different shapes and animations. Before this summer, I knew very little about virtual reality and I did not know VRML at all. I learned the VRML language by reading two books and experimenting on a PC. The following topics are presented: CAD to VRML, VRML 1.0 to VRML 2.0, VRML authoring tools, VRML browsers, finding virtual reality applications, the AXAF project, the VRML generator program, web communities and future plans.

  16. Spent fuel pin temperature PC code

    SciTech Connect

    Fischer, L.E.

    1985-03-01

    During an annual outage, a Pressurized Water Reactor (PWR) may discharge 60 or more spent fuel bundles into its storage pool. Most early PWRs were built to store 3 to 5 years of spent fuel in their pools and are beginning to exceed their capacities. One method currently being developed and licensed for expanding spent fuel storage capabilities is the dry storage of spent fuel in large casks. To reduce the probability of gross failures of fuel cladding during dry storage in casks, the fuel pin temperatures must be shown to remain within acceptable limits. LLNL has developed, for the Nuclear Regulatory Commission, a personal computer (PC) code for calculating fuel pin temperatures on the IBM PC. The code uses the Wooton-Epstein Correlation to calculate the pin temperatures and has been benchmarked against test data. An iterative type of solution is used to calculate the fuel pin temperatures for specified heat fluxes and pin configurations. The PC code is useful in performing confirmatory analyses and comparing the results with those submitted by applicants applying for storage licenses. 5 references, 2 tables.

  17. Transoral decompression evaluated by cine-mode magnetic resonance imaging: a case of basilar impression accompanied by Chiari malformation.

    PubMed

    Tominaga, T; Koshu, K; Ogawa, A; Yoshimoto, T

    1991-06-01

    Cine-mode magnetic resonance imaging provides simultaneous images of cerebrospinal fluid flow dynamics. A patient with a basilar impression accompanied by a Chiari malformation and von Recklinghausen's disease who underwent transoral decompression is reported. Preoperative cine-mode magnetic resonance imaging visualized an associated obstruction of cerebrospinal fluid pulsatile flow at the level of the foramen magnum. Tonsilar herniation (Chiari I malformation) and hydrocephalus were also present. Postoperatively, the obstruction of cerebrospinal fluid flow was resolved concomitant with the correction of the cervicomedullary angulation. On the basis of observations made by magnetic resonance imaging, the surgical treatment of basilar impression accompanied by Chiari malformation is briefly discussed.

  18. SU-E-J-192: Verification of 4D-MRI Internal Target Volume Using Cine MRI

    SciTech Connect

    Lafata, K; Czito, B; Palta, M; Bashir, M; Yin, F; Cai, J

    2014-06-01

    Purpose: To investigate the accuracy of 4D-MRI in determining the Internal Target Volume (ITV) used in radiation oncology treatment planning of liver cancers. Cine MRI is used as the standard baseline in establishing the feasibility and accuracy of 4D-MRI tumor motion within the liver. Methods: IRB approval was obtained for this retrospective study. Analysis was performed on MR images from four patients receiving external beam radiation therapy for liver cancer at our institution. Eligible patients received both Cine and 4D-MRI scans before treatment. Cine images were acquired sagittally in real time at a slice bisecting the tumor, while 4D images were acquired volumetrically. Cine MR DICOM headers were manipulated such that each respiratory frame was assigned a unique slice location. This approach permitted the treatment planning system (Eclipse, Varian Medical Systems) to recognize a complete respiratory cycle as a “volume”, where the gross tumor was contoured temporally. Software was developed to calculate the union of all frame contours in the structure set, resulting in the corresponding plane of the ITV projecting through the middle of the tumor, defined as the Internal Target Area (ITA). This was repeated for 4D-MRI, at the corresponding slice location, allowing a direct comparison of ITAs obtained from each modality. Results: Four patients have been analyzed. ITAs contoured from 4D-MRI correlate with contours from Cine MRI. The mean error of 4D values relative to Cine values is 7.67 +/− 2.55 %. No single ITA contoured from 4D-MRI demonstrated more than 10.5 % error compared to its Cine MRI counterpart. Conclusion: Motion management is a significant aspect of treatment planning within dynamic environments such as the liver, where diaphragmatic and cardiac activity influence plan accuracy. This small pilot study suggests that 4D-MRI based ITA measurements agree with Cine MRI based measurements, an important step towards clinical implementation. NIH 1R21

  19. 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)

  20. Quantification of Esophageal Tumor Motion on Cine-Magnetic Resonance Imaging

    SciTech Connect

    Lever, Frederiek M.; Lips, Irene M.; Crijns, Sjoerd P.M.; Reerink, Onne; Lier, Astrid L.H.M.W. van; Moerland, Marinus A.; Vulpen, Marco van; Meijer, Gert J.

    2014-02-01

    Purpose: To quantify the movement of esophageal tumors noninvasively on cine-magnetic resonance imaging (MRI) by use of a semiautomatic method to visualize tumor movement directly throughout multiple breathing cycles. Methods and Materials: Thirty-six patients with esophageal tumors underwent MRI. Tumors were located in the upper (8), middle (7), and lower (21) esophagus. Cine-MR images were collected in the coronal and sagittal plane during 60 seconds at a rate of 2 Hz. An adaptive correlation filter was used to automatically track a previously marked reference point. Tumor movement was measured in the craniocaudal (CC), left–right (LR), and anteroposterior (AP) directions and its relationship along the longitudinal axis of the esophagus was investigated. Results: Tumor registration within the individual images was typically done at a millisecond time scale. The mean (SD) peak-to-peak displacements in the CC, AP, and LR directions were 13.3 (5.2) mm, 4.9 (2.5) mm, and 2.7 (1.2) mm, respectively. The bandwidth to cover 95% of excursions from the mean position (c95) was also calculated to exclude outliers caused by sporadic movements. The mean (SD) c95 values were 10.1 (3.8) mm, 3.7 (1.9) mm, and 2.0 (0.9) mm in the CC, AP, and LR dimensions. The end-exhale phase provided a stable position in the respiratory cycle, compared with more variety in the end-inhale phase. Furthermore, lower tumors showed more movement than did higher tumors in the CC and AP directions. Conclusions: Intrafraction tumor movement was highly variable between patients. Tumor position proved the most stable during the respiratory cycle in the end-exhale phase. A better understanding of tumor motion makes it possible to individualize radiation delivery strategies accordingly. Cine-MRI is a successful noninvasive modality to analyze motion for this purpose in the future.

  1. Pseudo‐projection–driven, self‐gated cardiac cine imaging using cartesian golden step phase encoding

    PubMed Central

    Guo, Liheng; Derbyshire, J. Andrew

    2015-01-01

    Purpose To develop and evaluate a novel two‐dimensional self‐gated imaging technique for free‐breathing cardiac cine MRI that is free of motion‐detection overhead and requires minimal planning for motion tracking. Methods Motion along the readout direction was extracted solely from normal Cartesian imaging readouts near ky = 0. During imaging, the readouts below a certain |ky| threshold were scaled in magnitude and filtered in time to form “pseudo‐projections,” enabling projection‐based motion tracking along readout without frequently acquiring the central phase encode. A discrete golden step phase encode scheme allowed the |ky| threshold to be freely set after the scan while maintaining uniform motion sampling. Results The pseudo‐projections stream displayed sufficient spatiotemporal resolution for both cardiac and respiratory tracking, allowing retrospective reconstruction of free‐breathing non‐electrocardiogram (ECG) cines. The technique was tested on healthy subjects, and the resultant image quality, measured by blood‐myocardium boundary sharpness, myocardial mass, and single‐slice ejection fraction was found to be comparable to standard breath‐hold ECG‐gated cines. Conclusion The use of pseudo‐projections for motion tracking was found feasible for cardiorespiratory self‐gated imaging. Despite some sensitivity to flow and eddy currents, the simplicity of acquisition makes the proposed technique a valuable tool for self‐gated cardiac imaging. Magn Reson Med 76:417–429, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. PMID

  2. Comparison of Liver Tumor Motion With and Without Abdominal Compression Using Cine-Magnetic Resonance Imaging

    SciTech Connect

    Eccles, Cynthia L.; Patel, Ritesh; Simeonov, Anna K.; Lockwood, Gina; Haider, Masoom; Dawson, Laura A.

    2011-02-01

    Purpose: Abdominal compression (AC) can be used to reduce respiratory liver motion in patients undergoing liver stereotactic body radiotherapy. The purpose of the present study was to measure the changes in three-dimensional liver tumor motion with and without compression using cine-magnetic resonance imaging. Patients and Methods: A total of 60 patients treated as a part of an institutional research ethics board-approved liver stereotactic body radiotherapy protocol underwent cine T2-weighted magnetic resonance imaging through the tumor centroid in the coronal and sagittal planes. A total of 240 cine-magnetic resonance imaging sequences acquired at one to three images each second for 30-60 s were evaluated using an in-house-developed template matching tool (based on the coefficient correlation) to measure the magnitude of the tumor motion. The average tumor edge displacements were used to determine the magnitude of changes in the caudal-cranial (CC) and anteroposterior (AP) directions, with and without AC. Results: The mean tumor motion without AC of 11.7 mm (range, 4.8-23.3) in the CC direction was reduced to 9.4 mm (range, 1.6-23.4) with AC. The tumor motion was reduced in both directions (CC and AP) in 52% of the patients and in a single direction (CC or AP) in 90% of the patients. The mean decrease in tumor motion with AC was 2.3 and 0.6 mm in the CC and AP direction, respectively. Increased motion occurred in one or more directions in 28% of patients. Clinically significant (>3 mm) decreases were observed in 40% and increases in <2% of patients in the CC direction. Conclusion: AC can significantly reduce three-dimensional liver tumor motion in most patients, although the magnitude of the reduction was smaller than previously reported.

  3. Epid cine acquisition mode for in vivo dosimetry in dynamic arc radiation therapy

    NASA Astrophysics Data System (ADS)

    Fidanzio, Andrea; Mameli, Alessandra; Placidi, Elisa; Greco, Francesca; Stimato, Gerardina; Gaudino, Diego; Ramella, Sara; D'Angelillo, Rolando; Cellini, Francesco; Trodella, Lucio; Cilla, Savino; Grimaldi, Luca; D'Onofrio, Guido; Azario, Luigi; Piermattei, Angelo

    2008-02-01

    In this paper the cine acquisition mode of an electronic portal imaging device (EPID) has been calibrated and tested to determine the in vivo dose for dynamic conformal arc radiation therapy (DCAT). The EPID cine acquisition mode, that allows a frame acquisition rate of one image every 1.66 s, was studied with a monitor unit rate equal to 100 UM/min. In these conditions good signal stability, ±1% (2SD) evaluated during three months, signal reproducibility within ±0.8% (2SD) and linearity with dose and dose rate within ±1% (2SD) were obtained. The transit signal, St, (due to the transmitted beam below the phantom) measured by the EPID cine acquisition mode was used to determine, (i) a set of correlation functions, F(w,L), defined as the ratio between St and the dose at half thickness, Dm, measured in solid water phantoms of different thicknesses, w and with square fields of side L, (ii) a set of factors, f(d,L), that take into account the different X-ray scatter contribution from the phantom to the St signal as a function of the variation, d, of the air gap between the phantom and the EPID. The reconstruction of the isocenter dose, Diso, for DCAT was obtained convolving the transit signal values, obtained at different gantry angles, with the respective reconstruction factors determined by a house-made software. The method was tested with cylindrical and anthropomorphic phantoms and the results show that the reconstructed Diso values can be obtained with an accuracy within ±2.5% in cylindrical phantom and within ±3.4% for anthropomorphic phantom. In conclusion, the transit dosimetry by EPID was assessed to be adequate to perform DCAT in vivo dosimetry, that is not realizable with the other traditional techniques. Moreover, the method proposed here could be implemented to supply in vivo dose values in real time.

  4. 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.

  5. Features of Pc5 pulsations in the geomagnetic field, auroral luminosity, and Riometer absorption

    NASA Astrophysics Data System (ADS)

    Belakhovsky, V. B.; Pilipenko, V. A.; Samsonov, S. N.; Lorentsen, D.

    2016-01-01

    Simultaneous morning Pc5 pulsations ( f ~ 3-5 mHz) in the geomagnetic field, aurora intensities (in the 557.7 and 630.0 nm oxygen emissions and the 471.0 nm nitrogen emission), and riometer absorption, were studied based on the CARISMA, CANMOS, and NORSTAR network data for the event of January 1, 2000. According to the GOES-8 satellite observations, these Pc5 geomagnetic pulsations are observed as incompressible Alfvén waves with toroidal polarization in the magnetosphere. Although the Pc5 pulsation frequencies in auroras, the geomagnetic field, and riometer absorption are close to one another, stable phase relationships are not observed between them. Far from all trains of geomagnetic Pc5 pulsations are accompanied by corresponding auroral pulsations; consequently, geomagnetic pulsations are primary with respect to auroral pulsations. Both geomagnetic and auroral pulsations propagate poleward, and the frequency decreases with increasing geomagnetic latitude. When auroral Pc5 pulsations appear, the ratio of the 557.7/630.0 nm emission intensity sharply increases, which indicates that auroral pulsations result from not simply modulated particle precipitation but also an additional periodic acceleration of auroral electrons by the wave field. A high correlation is not observed between Pc5 pulsations in auroras and the riometer absorption, which indicates that these pulsations have a common source but different generation mechanisms. Auroral luminosity modulation is supposedly related to the interaction between Alfvén waves and the region with the field-aligned potential drop above the auroral ionosphere, and riometer absorption modulation is caused by the scattering of energetic electrons by VLF noise pulsations.

  6. Implementation of compressive sensing for preclinical cine-MRI

    NASA Astrophysics Data System (ADS)

    Tan, Elliot; Yang, Ming; Ma, Lixin; Zheng, Yahong Rosa

    2014-03-01

    This paper presents a practical implementation of Compressive Sensing (CS) for a preclinical MRI machine to acquire randomly undersampled k-space data in cardiac function imaging applications. First, random undersampling masks were generated based on Gaussian, Cauchy, wrapped Cauchy and von Mises probability distribution functions by the inverse transform method. The best masks for undersampling ratios of 0.3, 0.4 and 0.5 were chosen for animal experimentation, and were programmed into a Bruker Avance III BioSpec 7.0T MRI system through method programming in ParaVision. Three undersampled mouse heart datasets were obtained using a fast low angle shot (FLASH) sequence, along with a control undersampled phantom dataset. ECG and respiratory gating was used to obtain high quality images. After CS reconstructions were applied to all acquired data, resulting images were quantitatively analyzed using the performance metrics of reconstruction error and Structural Similarity Index (SSIM). The comparative analysis indicated that CS reconstructed images from MRI machine undersampled data were indeed comparable to CS reconstructed images from retrospective undersampled data, and that CS techniques are practical in a preclinical setting. The implementation achieved 2 to 4 times acceleration for image acquisition and satisfactory quality of image reconstruction.

  7. High speed cine film studies of plasma behaviour and plasma surface interactions in tokamaks

    NASA Astrophysics Data System (ADS)

    Goodall, D. H. J.

    1982-12-01

    High speed cine photography is a useful diagnostic aid for studying plasma behaviour and plasma surface interactions. Several workers have filmed discharges in tokamaks including ASDEX, DITE, DIVA, ISX, JFT2, TFR and PLT. These films are discussed and examples given of the observed phenomena which include plasma limiter interactions, diverted discharges, disruptions, magnetic islands and moving glowing objects often known as 'UFOs'. Examples of plasma structures in ASDEX and DITE not previously published are also given. The paper also reports experiments in DITE to determine the origin of UFOs.

  8. Verification of the linac isocenter for stereotactic radiosurgery using cine-EPID imaging and arc delivery

    SciTech Connect

    Rowshanfarzad, Pejman; Sabet, Mahsheed; O' Connor, Daryl J.; Greer, Peter B.

    2011-07-15

    Purpose:Verification of the mechanical isocenter position is required as part of comprehensive quality assurance programs for stereotactic radiosurgery/radiotherapy (SRS/SRT) treatments. Several techniques have been proposed for this purpose but each of them has certain drawbacks. In this paper, a new efficient and more comprehensive method using cine-EPID images has been introduced for automatic verification of the isocenter with sufficient accuracy for stereotactic applications. Methods: Using a circular collimator fixed to the gantry head to define the field, EPID images of a Winston-Lutz phantom were acquired in cine-imaging mode during 360 deg. gantry rotations. A robust matlab code was developed to analyze the data by finding the center of the field and the center of the ball bearing shadow in each image with sub-pixel accuracy. The distance between these two centers was determined for every image. The method was evaluated by comparison to results of a mechanical pointer and also by detection of a manual shift applied to the phantom position. The repeatability and reproducibility of the method were tested and it was also applied to detect couch and collimator wobble during rotation. Results:The accuracy of the algorithm was 0.03 {+-} 0.02 mm. The repeatability was less than 3 {mu}m and the reproducibility was less than 86 {mu}m. The time elapsed for the analysis of more than 100 cine images of Varian aS1000 and aS500 EPIDs were {approx}65 and 20 s, respectively. Processing of images taken in integrated mode took 0.1 s. The output of the analysis software is printable and shows the isocenter shifts as a function of angle in both in-plane and cross-plane directions. It gives warning messages where the shifts exceed the criteria for SRS/SRT and provides useful data for the necessary adjustments in the system including bearing system and/or room lasers. Conclusions: The comprehensive method introduced in this study uses cine-images, is highly accurate, fast, and

  9. Impact accelerations

    NASA Technical Reports Server (NTRS)

    Vongierke, H. E.; Brinkley, J. W.

    1975-01-01

    The degree to which impact acceleration is an important factor in space flight environments depends primarily upon the technology of capsule landing deceleration and the weight permissible for the associated hardware: parachutes or deceleration rockets, inflatable air bags, or other impact attenuation systems. The problem most specific to space medicine is the potential change of impact tolerance due to reduced bone mass and muscle strength caused by prolonged weightlessness and physical inactivity. Impact hazards, tolerance limits, and human impact tolerance related to space missions are described.

  10. An Efficient Framework for Compressed Sensing Reconstruction of Highly Accelerated Dynamic Cardiac MRI

    NASA Astrophysics Data System (ADS)

    Ting, Samuel T.

    cine images. First, algorithmic and implementational approaches are proposed for reducing the computational time for a compressed sensing reconstruction framework. Specific optimization algorithms based on the fast iterative/shrinkage algorithm (FISTA) are applied in the context of real-time cine image reconstruction to achieve efficient per-iteration computation time. Implementation within a code framework utilizing commercially available graphics processing units (GPUs) allows for practical and efficient implementation directly within the clinical environment. Second, patch-based sparsity models are proposed to enable compressed sensing signal recovery from highly undersampled data. Numerical studies demonstrate that this approach can help improve image quality at higher undersampling ratios, enabling real-time cine imaging at higher acceleration rates. In this work, it is shown that these techniques yield a holistic framework for achieving efficient reconstruction of real-time cine images with spatial and temporal resolution sufficient for use in the clinical environment. A thorough description of these techniques from both a theoretical and practical view is provided - both of which may be of interest to the reader in terms of future work.

  11. 39 CFR 501.16 - PC postage payment methodology.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false PC postage payment methodology. 501.16 Section 501.16 Postal Service UNITED STATES POSTAL SERVICE POSTAGE PROGRAMS AUTHORIZATION TO MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.16 PC postage payment methodology. (a) The PC Postage customer...

  12. The USL NASA PC R and D development environment standards

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Moreau, Dennis R.

    1984-01-01

    The development environment standards which have been established in order to control usage of the IBM PC/XT development systems and to prevent interference between projects being currently developed on the PC's are discussed. The standards address the following areas: scheduling PC resources; login/logout procedures; training; file naming conventions; hard disk organization; diskette care; backup procedures; and copying policies.

  13. Wf/pc Cycle 1 Calib: Non-Sv PC Flats 2

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This program takes "uniform illuminated" pictures of the earth to obtain the "instrument signature" for flat field corrections. This proposal series contains observations for all PC filters used by GOs and GTOs during Cycle 1 which were not included in the SV program. The camera - filter combinations done in this proposal are: PC: F569W, F606W, F675W, F725LP, F791W, F814W, F850LP (these are done in combination with F122M) These are the PC flats which are expected to saturate on the bright earth without a neutral density filter. The following observations are also included to permit correction for the F122M filter: F517N+F122M, F517N, F664N+F122M, F664N, F718M+F122M, F718M, F875M+F122M, F875M

  14. IBM PC/IX operating system evaluation plan

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Granier, Martin; Hall, Philip P.; Triantafyllopoulos, Spiros

    1984-01-01

    An evaluation plan for the IBM PC/IX Operating System designed for IBM PC/XT computers is discussed. The evaluation plan covers the areas of performance measurement and evaluation, software facilities available, man-machine interface considerations, networking, and the suitability of PC/IX as a development environment within the University of Southwestern Louisiana NASA PC Research and Development project. In order to compare and evaluate the PC/IX system, comparisons with other available UNIX-based systems are also included.

  15. Effects of Incentive Spirometry on Respiratory Motion in Healthy Subjects Using Cine Breathing Magnetic Resonance Imaging

    PubMed Central

    Akazawa, Tsutomu; Sakuma, Tsuyoshi; Nagaya, Shigeyuki; Sonoda, Masaru; Tanaka, Yuji; Katogi, Takehide; Nemoto, Tetsuharu; Minami, Shohei

    2015-01-01

    Objective To investigate the effectiveness of incentive spirometry on respiratory motion in healthy subjects using cine breathing magnetic resonance imaging (MRI). Methods Ten non-smoking healthy subjects without any history of respiratory disease were studied. Subjects were asked to perform pulmonary training using incentive spirometry every day for two weeks. To assess the effectiveness of this training, pulmonary function tests and cine breathing MRI were performed before starting pulmonary training and two weeks after its completion. Results After training, there were significant improvements in vital capacity (VC) from 3.58±0.8 L to 3.74±0.8 L and in %VC from 107.4±10.8 to 112.1±8.2. Significant changes were observed in the right diaphragm motion, right chest wall motion, and left chest wall motion, which were increased from 55.7±9.6 mm to 63.4±10.2 mm, from 15.6±6.1 mm to 23.4±10.4 mm, and from 16.3±7.6 mm to 22.0±9.8 mm, respectively. Conclusion Two weeks of training using incentive spirometry provided improvements in pulmonary function and respiratory motion, which suggested that incentive spirometry may be a useful preoperative modality for improving pulmonary function during the perioperative period. PMID:26161341

  16. Fully automated segmentation of left ventricle using dual dynamic programming in cardiac cine MR images

    NASA Astrophysics Data System (ADS)

    Jiang, Luan; Ling, Shan; Li, Qiang

    2016-03-01

    Cardiovascular diseases are becoming a leading cause of death all over the world. The cardiac function could be evaluated by global and regional parameters of left ventricle (LV) of the heart. The purpose of this study is to develop and evaluate a fully automated scheme for segmentation of LV in short axis cardiac cine MR images. Our fully automated method consists of three major steps, i.e., LV localization, LV segmentation at end-diastolic phase, and LV segmentation propagation to the other phases. First, the maximum intensity projection image along the time phases of the midventricular slice, located at the center of the image, was calculated to locate the region of interest of LV. Based on the mean intensity of the roughly segmented blood pool in the midventricular slice at each phase, end-diastolic (ED) and end-systolic (ES) phases were determined. Second, the endocardial and epicardial boundaries of LV of each slice at ED phase were synchronously delineated by use of a dual dynamic programming technique. The external costs of the endocardial and epicardial boundaries were defined with the gradient values obtained from the original and enhanced images, respectively. Finally, with the advantages of the continuity of the boundaries of LV across adjacent phases, we propagated the LV segmentation from the ED phase to the other phases by use of dual dynamic programming technique. The preliminary results on 9 clinical cardiac cine MR cases show that the proposed method can obtain accurate segmentation of LV based on subjective evaluation.

  17. Measurement of complex joint trajectories using slice-to-volume 2D/3D registration and cine MR

    NASA Astrophysics Data System (ADS)

    Bloch, C.; Figl, M.; Gendrin, C.; Weber, C.; Unger, E.; Aldrian, S.; Birkfellner, W.

    2010-02-01

    A method for studying the in vivo kinematics of complex joints is presented. It is based on automatic fusion of single slice cine MR images capturing the dynamics and a static MR volume. With the joint at rest the 3D scan is taken. In the data the anatomical compartments are identified and segmented resulting in a 3D volume of each individual part. In each of the cine MR images the joint parts are segmented and their pose and position are derived using a 2D/3D slice-to-volume registration to the volumes. The method is tested on the carpal joint because of its complexity and the small but complex motion of its compartments. For a first study a human cadaver hand was scanned and the method was evaluated with artificially generated slice images. Starting from random initial positions of about 5 mm translational and 12° rotational deviation, 70 to 90 % of the registrations converged successfully to a deviation better than 0.5 mm and 5°. First evaluations using real data from a cine MR were promising. The feasibility of the method was demonstrated. However we experienced difficulties with the segmentation of the cine MR images. We therefore plan to examine different parameters for the image acquisition in future studies.

  18. Clinical Applications of Cine Balanced Steady-State Free Precession MRI for the Evaluation of the Subarachnoid Spaces.

    PubMed

    Li, A E; Wilkinson, M D; McGrillen, K M; Stoodley, M A; Magnussen, J S

    2015-12-01

    The purpose of this article is to review the physiology of normal brain and spinal cord motion in the subarachnoid space, principles of cine balanced steady-state free precession (bSSFP) magnetic resonance imaging (MRI), clinical applications, and the pitfalls encountered with this technique. The brain and spinal cord are dynamic structures that move with each heartbeat due to transmitted arterial pulse waves. Conventional MRI sequences do not allow anatomic evaluation of the pulsatile movement of the neural structures in the subarachnoid space due to limitations in temporal resolution. Cine bSSFP MRI uses cardiac gating to evaluate dynamically the brain and spinal cord with high contrast and temporal resolution.Cine bSSFP can be used in the evaluation of idiopathic syringomyelia to assess an underlying treatable cause, including arachnoid bands, which are usually not well visualized with conventional MR sequences due to motion artifact. This MRI technique is also useful in the evaluation of intraspinal and intracranial arachnoid cysts and the degree of mass effect on the cord. Other applications include preoperative and postoperative evaluation of Chiari I malformation and the evaluation of lateral ventricular asymmetry. The major limitation of cine bSSFP is the presence of banding artifacts, which can be reduced by shimming and modifying other scan parameters.

  19. 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.

  20. Accuracy of respiratory motion measurement of 4D-MRI: A comparison between cine and sequential acquisition

    PubMed Central

    Liu, Yilin; Yin, Fang-Fang; Rhee, DongJoo; Cai, Jing

    2016-01-01

    Purpose: The authors have recently developed a cine-mode T2*/T1-weighted 4D-MRI technique and a sequential-mode T2-weighted 4D-MRI technique for imaging respiratory motion. This study aims at investigating which 4D-MRI image acquisition mode, cine or sequential, provides more accurate measurement of organ motion during respiration. Methods: A 4D digital extended cardiac-torso (XCAT) human phantom with a hypothesized tumor was used to simulate the image acquisition and the 4D-MRI reconstruction. The respiratory motion was controlled by the given breathing signal profiles. The tumor was manipulated to move continuously with the surrounding tissue. The motion trajectories were measured from both sequential- and cine-mode 4D-MRI images. The measured trajectories were compared with the average trajectory calculated from the input profiles, which was used as references. The error in 4D-MRI tumor motion trajectory (E) was determined. In addition, the corresponding respiratory motion amplitudes of all the selected 2D images for 4D reconstruction were recorded. Each of the amplitude was compared with the amplitude of its associated bin on the average breathing curve. The mean differences from the average breathing curve across all slice positions (D) were calculated. A total of 500 simulated respiratory profiles with a wide range of irregularity (Ir) were used to investigate the relationship between D and Ir. Furthermore, statistical analysis of E and D using XCAT controlled by 20 cancer patients’ breathing profiles was conducted. Wilcoxon Signed Rank test was conducted to compare two modes. Results: D increased faster for cine-mode (D = 1.17 × Ir + 0.23) than sequential-mode (D = 0.47 × Ir + 0.23) as irregularity increased. For the XCAT study using 20 cancer patients’ breathing profiles, the median E values were significantly different: 0.12 and 0.10 cm for cine- and sequential-modes, respectively, with a p-value of 0.02. The median D values were significantly

  1. The Local Population of White Dwarfs within 25 pc

    NASA Astrophysics Data System (ADS)

    Holberg, Jay B.; Oswalt, Terry D.; Sion, Edward M.

    2015-01-01

    We have extended the detailed survey of the local white dwarf population from 20 pc to 25 pc, effectively doubling the sample volume to now include 231 stars. The present 25 pc has an estimated completeness of 70% (the corresponding 20 pc sample is now 85% complete). The space density of white dwarfs remains at 4.8 ± 0.5 x 10-3 pc-3. There exists a curious excess of single stars in the sample 70% vs 30% in systems with one or more companions. A pronounced apparent deficiency remains between the eleven known Sirius-like systems present in the 20 pc sample and only a single such system presently known in the extended 25 pc sample. Also demonstrated, using explicit individual white dwarf cooling ages, is the feasibility of estimating the white dwarf birth rates over the last ~ 5 Gyr.This work is supported by NSF grant AST-1413537

  2. PC-based Multiple Information System Interface (PC/MISI) detailed design and implementation plan

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Hall, Philip P.

    1985-01-01

    The design plan for the personal computer multiple information system interface (PC/MISI) project is discussed. The document is intended to be used as a blueprint for the implementation of the system. Each component is described in the detail necessary to allow programmers to implement the system. A description of the system data flow and system file structures is given.

  3. THE ORIGIN OF OB CLUSTERS: FROM 10 pc TO 0.1 pc

    SciTech Connect

    Liu Hauyu Baobab; Wang Ke; Ho, Paul T. P.; Zhang Qizhou; Quintana-Lacaci, Guillermo; Li Zhiyun; Zhang Zhiyu E-mail: kwang@cfa.harvard.edu E-mail: quintana@iram.es E-mail: zl4h@virginia.edu

    2012-01-20

    We observe the 1.2 mm continuum emission around the OB cluster-forming region G10.6-0.4, using the MAMBO-2 bolometer array of the IRAM 30 m telescope and the Submillimeter Array (SMA). Comparison of the Spitzer 24 {mu}m and 8 {mu}m images with our 1.2 mm continuum maps reveal an ionization front of an H II region, the photon-dominated layer, and several 5 pc scale filaments that follow the outer edge of the photon-dominated layer. The filaments, which are resolved in the MAMBO-2 observations, show regularly spaced parsec-scale molecular clumps, embedded with a cluster of dense molecular cores as shown in the SMA 0.87 mm observations. Toward the center of the G10.6-0.4 region, the combined SMA+IRAM 30 m continuum image reveals several parsec-scale protrusions. They may continue down to within 0.1 pc of the geometric center of a dense 3 pc scale structure, where a 200 M{sub Sun} OB cluster resides. The observed filaments may facilitate mass accretion onto the central cluster-forming region in the presence of strong radiative and mechanical stellar feedback. Their filamentary geometry may also facilitate fragmentation. We did not detect any significant polarized emission at 0.87 mm in the inner 1 pc region with SMA.

  4. (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8]/CuPc two-component bilayer heterojunction-based organic transistors with high ambipolar performance.

    PubMed

    Gao, Dameng; Zhang, Xia; Kong, Xia; Chen, Yanli; Jiang, Jianzhuang

    2015-02-04

    Organic thin film transistor (OTFT) devices fabricated by the solution-based QLS technique from a mixed (phthalocyaninato)(porphyrinato) europium complex (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] exhibit air-stable ambipolar performance with mobilities of 6.0 × 10(-5) cm(2) V(-1) s(-)1 for holes and 1.4 × 10(-4) cm(2) V(-1) s(-1) for electrons, respectively. In good contrast, the two-component bilayer heterojunction thin film devices constructed by directly growing (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] on vacuum deposited (VCD) CuPc film using solution based QLS method were revealed to show unprecedented ambipolar performance with carrier mobilities of 0.16 cm(2) V(-1) s(-1) for holes and 0.30 cm(2) V(-1) s(-1) for electrons. In addition to the intrinsic role of p-type organic semiconductor, the VCD CuPc film on the substrate also acts as a good template that induces significant improvement over the molecular ordering of triple-decker compound in the film. In particular, it results in the change in the aggregation mode of (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] from J-type in the single-layer film to H-type in the bilayer film according to the UV-vis, XRD, and AFM observations.

  5. Acceleration modules in linear induction accelerators

    NASA Astrophysics Data System (ADS)

    Wang, Shao-Heng; Deng, Jian-Jun

    2014-05-01

    The Linear Induction Accelerator (LIA) is a unique type of accelerator that is capable of accelerating kilo-Ampere charged particle current to tens of MeV energy. The present development of LIA in MHz bursting mode and the successful application into a synchrotron have broadened LIA's usage scope. Although the transformer model is widely used to explain the acceleration mechanism of LIAs, it is not appropriate to consider the induction electric field as the field which accelerates charged particles for many modern LIAs. We have examined the transition of the magnetic cores' functions during the LIA acceleration modules' evolution, distinguished transformer type and transmission line type LIA acceleration modules, and re-considered several related issues based on transmission line type LIA acceleration module. This clarified understanding should help in the further development and design of LIA acceleration modules.

  6. METCAN-PC - METAL MATRIX COMPOSITE ANALYZER

    NASA Technical Reports Server (NTRS)

    Murthy, P. L.

    1994-01-01

    High temperature metal matrix composites offer great potential for use in advanced aerospace structural applications. The realization of this potential however, requires concurrent developments in (1) a technology base for fabricating high temperature metal matrix composite structural components, (2) experimental techniques for measuring their thermal and mechanical characteristics, and (3) computational methods to predict their behavior. METCAN (METal matrix Composite ANalyzer) is a computer program developed to predict this behavior. METCAN can be used to computationally simulate the non-linear behavior of high temperature metal matrix composites (HT-MMC), thus allowing the potential payoff for the specific application to be assessed. It provides a comprehensive analysis of composite thermal and mechanical performance. METCAN treats material nonlinearity at the constituent (fiber, matrix, and interphase) level, where the behavior of each constituent is modeled accounting for time-temperature-stress dependence. The composite properties are synthesized from the constituent instantaneous properties by making use of composite micromechanics and macromechanics. Factors which affect the behavior of the composite properties include the fabrication process variables, the fiber and matrix properties, the bonding between the fiber and matrix and/or the properties of the interphase between the fiber and matrix. The METCAN simulation is performed as point-wise analysis and produces composite properties which are readily incorporated into a finite element code to perform a global structural analysis. After the global structural analysis is performed, METCAN decomposes the composite properties back into the localized response at the various levels of the simulation. At this point the constituent properties are updated and the next iteration in the analysis is initiated. This cyclic procedure is referred to as the integrated approach to metal matrix composite analysis. METCAN-PC

  7. 3D Finite Element Analysis of Some Structural Modified PC Sleeper with the Vibration Characteristics between Sleeper and Ballast

    NASA Astrophysics Data System (ADS)

    Sakai, Hirotaka; Urakawa, Fumihiro; Aikawa, Akira; Namura, Akira

    The vibration of concrete sleepers is an important factor engendering track deterioration. In this paper, we created a three-dimensional finite element model to reproduce a prestressed concrete (PC) sleeper in detail, expressing influence of ballast layers with a 3D spring series and dampers to reproduce their vibration and dynamic characteristics. Determination of these parameters bases on the experimental modal analysis using an impact excitation technique for PC sleepers by adjusting the accelerance between the analytical results and experimental results. Furthermore, we compared the difference of these characteristics between normal sleepers and those with some structural modifications. Analytical results clarified that such means as sleeper width extension and increased sleeper thickness will influence the reduction of ballasted track vibration as improvements of PC sleepers.

  8. [Report on the VDÄPC Fellowship].

    PubMed

    Sarantopoulos, E

    2016-04-01

    "Orandum est ut sit mens sana in corpore sano" ("You should pray for a healthy mind in a healthy body"). This phrase is a shortened citation from the satirical work of the Roman poet Juvenal. It highlights the significant role of physical as well as mental health. Aesthetic ideals have existed since the Archaic age, but they are not necessarily the same in different continents. Being familiar with aesthetic ideals in different cultures might help to accommodate patients' needs and wishes in today's globalised world. Therefore, fellowship programs such as the program organised by the Association of German Aesthetic Plastic Surgeons ("VDÄPC") are very important for young plastic surgeons who are interested in improving their surgical skills and experience. After all, aesthetic surgery is a dynamic specialty, which requires aesthetic plastic surgeons to undergo continued medical education.

  9. Pathway Controlled Penetration (PcP)

    SciTech Connect

    Knight, Earl E.; Rougier, Esteban; Zubelewicz, Aleksander

    2012-08-29

    The technical approach employs advanced computational simulation tools to demonstrate how current assets can destroy RWK-RFI-12-0001's HDBT, a tunnel complex with two portals built into the base of a granite mountain. The granite over layer is assumed to be 60 meters thick over both portals and 80 meters over the facility's mission space. Key S&T is the completed development of a highly innovative viscoplastic fracture material model, 3D parallel gas-fracture capabilities into FDEM, and a stochastic handling of the material properties. Phase I - Develop and validate code simulation tools: (1) develop, incorporate and validate AZ-Frac material model for granite; and (2) Develop and incorporate gas-driven-fracture modeling into LANL's FDEM MUNROU code; (3) Develop and incorporate stochastic features into FDEM modeling. Phase II - Conduct PcP analysis on above HDBT: (1) Acquire HDBT design data, develop simulation model; and (2) Evaluate and select most promising defeat alternative. Phase III - Deliver code, train Service target analysts, and conduct simulations against real world HDBTs. PcP uses advanced computer simulations to enhance HDBT functional defeat efforts. Newly developed material models that account for fractural energy coupled with the finite discrete element methodology (FDEM) will provide targeting packages that will create penetration avenues for current or future lethality options. This novel computational approach requires full 3D geologic and structure characterization as well as significant high performance computing capabilities. The goal is to distinctively alter the targeting paradigm by leveraging critical DoD assets along with insitu geologic strata. In other words, assets will utilize underground rock structure to their benefit by creating rubbilization zones that will allow pathway controlled penetration.

  10. Real-time automatic fiducial marker tracking in low contrast cine-MV images

    SciTech Connect

    Lin, Wei-Yang; Lin, Shu-Fang; Yang, Sheng-Chang; Liou, Shu-Cheng; Nath, Ravinder; Liu Wu

    2013-01-15

    Purpose: To develop a real-time automatic method for tracking implanted radiographic markers in low-contrast cine-MV patient images used in image-guided radiation therapy (IGRT). Methods: Intrafraction motion tracking using radiotherapy beam-line MV images have gained some attention recently in IGRT because no additional imaging dose is introduced. However, MV images have much lower contrast than kV images, therefore a robust and automatic algorithm for marker detection in MV images is a prerequisite. Previous marker detection methods are all based on template matching or its derivatives. Template matching needs to match object shape that changes significantly for different implantation and projection angle. While these methods require a large number of templates to cover various situations, they are often forced to use a smaller number of templates to reduce the computation load because their methods all require exhaustive search in the region of interest. The authors solve this problem by synergetic use of modern but well-tested computer vision and artificial intelligence techniques; specifically the authors detect implanted markers utilizing discriminant analysis for initialization and use mean-shift feature space analysis for sequential tracking. This novel approach avoids exhaustive search by exploiting the temporal correlation between consecutive frames and makes it possible to perform more sophisticated detection at the beginning to improve the accuracy, followed by ultrafast sequential tracking after the initialization. The method was evaluated and validated using 1149 cine-MV images from two prostate IGRT patients and compared with manual marker detection results from six researchers. The average of the manual detection results is considered as the ground truth for comparisons. Results: The average root-mean-square errors of our real-time automatic tracking method from the ground truth are 1.9 and 2.1 pixels for the two patients (0.26 mm/pixel). The

  11. GPU accelerated non-rigid registration for the evaluation of cardiac function.

    PubMed

    Li, Bo; Young, Alistair A; Cowan, Brett R

    2008-01-01

    We present a method for the fast and efficient tracking of motion in cardiac magnetic resonance (CMR) cines. A GPU accelerated Levenberg-Marquardt non-linear least squares optimization procedure for finite element non-rigid registration was implemented on an NVIDIA graphics card using the OpenGL environment. Points were tracked from frame to frame using forward and backward incremental registration. The inner (endocardial) and outer (epicardial) boarders of the heart were tracked in six short axis cines with approximately 25 frames through the cardiac cycle in 36 patients with vascular disease. Contours placed by two independent expert observers using a semi-automatic ventricular analysis program (CIM version 4.6) were used as the gold standard. The method took 0.5 seconds per frame, and the maximum Hausdorff errors were less than 2 mm on average which was of the same order as the expert inter-observer error. In conclusion, GPU accelerated Levenberg-Marquardt non-linear optimization enables fast and accurate tracking of cardiac motion in CMR images.

  12. Dependence of radiation belt enhancements on the radial extent of Pc5 waves and the plasmapause location

    NASA Astrophysics Data System (ADS)

    Georgiou, M.; Daglis, I. A.; Zesta, E.; Balasis, G.; Katsavrias, C.; Mann, I. R.; Tsinganos, K.

    2014-12-01

    Low-energy electrons are accelerated to relativistic energies through different mechanisms, transporting them across their drift shells to the outer radiation belt. Among the different acceleration mechanisms, radial diffusion describes the result of ULF magnetic field pulsations resonantly interacting with radiation belt electrons. In this paper, the radial positioning of the relativistic electron population during 39 intense and moderate magnetic storms is examined against that of ULF Pc5 wave power and the plasmapause location. The relativistic electron population of the outer radiation belt appeared enhanced in the 2 - 6 MeV electron flux data from SAMPEX and in > 2 MeV electron flux data from the geosynchronous GOES satellites following 27 of the magnetic storms. We compared relativistic electrons observations with concurrent radial distribution of wave power enhancements at Pc5 frequencies as detected by the IMAGE and CARISMA magnetometer arrays, as well as by additional magnetic stations collaborating in SuperMAG. We discuss the growth and decay characteristics of Pc5 waves in association with the plasmapause location, determined from IMAGE EUV observations, as the controlling factor for wave power penetration deep into the magnetosphere. We show that, during magnetic storms characterized by increased post-storm fluxes, Pc5 wave power penetrates to L shells of 4 and lower. On the other hand, magnetic storms which were characterised by loss of electrons were related to low Pc5 wave activity, which was not intensified at low L shells. These observations provide support for the hypothesis that enhanced Pc5 wave activity deep into the magnetosphere during the main and recovery phase can discriminate between storms that result in increases of electron fluxes from those that do not. The work leading to this paper has received funding from the European Union's Seventh Framework Programme (FP7-SPACE-2011-1) under grant agreement no. 284520 for the MAARBLE

  13. Progress on plasma accelerators

    SciTech Connect

    Chen, P.

    1986-05-01

    Several plasma accelerator concepts are reviewed, with emphasis on the Plasma Beat Wave Accelerator (PBWA) and the Plasma Wake Field Accelerator (PWFA). Various accelerator physics issues regarding these schemes are discussed, and numerical examples on laboratory scale experiments are given. The efficiency of plasma accelerators is then revealed with suggestions on improvements. Sources that cause emittance growth are discussed briefly.

  14. Microcomputer Applications with PC LAN (Local Area Network) in Battleships.

    DTIC Science & Technology

    1988-12-01

    9 G. INTEL 80386 MICROPROCESSOR ARCHITECTURE 9 1. Cache Strategy 10 2. Memory Management 10 3. Multitasking 11 4. Software...shrinks, it becomes more clear that the traditional modes of battle planning and management are no longer practical. Many of these problems, like...Card in it. Each PC must run the PC Network program to manage its participation in the network. Each PC must have a cable to connect it to the

  15. In vivo X-ray cine-tomography for tracking morphological dynamics.

    PubMed

    dos Santos Rolo, Tomy; Ershov, Alexey; van de Kamp, Thomas; Baumbach, Tilo

    2014-03-18

    Scientific cinematography using ultrafast optical imaging is a common tool to study motion. In opaque organisms or structures, X-ray radiography captures sequences of 2D projections to visualize morphological dynamics, but for many applications full four-dimensional (4D) spatiotemporal information is highly desirable. We introduce in vivo X-ray cine-tomography as a 4D imaging technique developed to study real-time dynamics in small living organisms with micrometer spatial resolution and subsecond time resolution. The method enables insights into the physiology of small animals by tracking the 4D morphological dynamics of minute anatomical features as demonstrated in this work by the analysis of fast-moving screw-and-nut-type weevil hip joints. The presented method can be applied to a broad range of biological specimens and biotechnological processes.

  16. In vivo X-ray cine-tomography for tracking morphological dynamics

    PubMed Central

    dos Santos Rolo, Tomy; Ershov, Alexey; van de Kamp, Thomas; Baumbach, Tilo

    2014-01-01

    Scientific cinematography using ultrafast optical imaging is a common tool to study motion. In opaque organisms or structures, X-ray radiography captures sequences of 2D projections to visualize morphological dynamics, but for many applications full four-dimensional (4D) spatiotemporal information is highly desirable. We introduce in vivo X-ray cine-tomography as a 4D imaging technique developed to study real-time dynamics in small living organisms with micrometer spatial resolution and subsecond time resolution. The method enables insights into the physiology of small animals by tracking the 4D morphological dynamics of minute anatomical features as demonstrated in this work by the analysis of fast-moving screw-and-nut–type weevil hip joints. The presented method can be applied to a broad range of biological specimens and biotechnological processes. PMID:24594600

  17. ELIPGRID-PC: A PC program for calculating hot spot probabilities

    SciTech Connect

    Davidson, J.R.

    1994-10-01

    ELIPGRID-PC, a new personal computer program has been developed to provide easy access to Singer`s 1972 ELIPGRID algorithm for hot-spot detection probabilities. Three features of the program are the ability to determine: (1) the grid size required for specified conditions, (2) the smallest hot spot that can be sampled with a given probability, and (3) the approximate grid size resulting from specified conditions and sampling cost. ELIPGRID-PC also provides probability of hit versus cost data for graphing with spread-sheets or graphics software. The program has been successfully tested using Singer`s published ELIPGRID results. An apparent error in the original ELIPGRID code has been uncovered and an appropriate modification incorporated into the new program.

  18. Analysis of speech and tongue motion in normal and post-glossectomy speaker using cine MRI

    PubMed Central

    Ha, Jinhee; Sung, Iel-yong; Son, Jang-ho; Stone, Maureen; Ord, Robert; Cho, Yeong-cheol

    2016-01-01

    ABSTRACT Objective Since the tongue is the oral structure responsible for mastication, pronunciation, and swallowing functions, patients who undergo glossectomy can be affected in various aspects of these functions. The vowel /i/ uses the tongue shape, whereas /u/ uses tongue and lip shapes. The purpose of this study is to investigate the morphological changes of the tongue and the adaptation of pronunciation using cine MRI for speech of patients who undergo glossectomy. Material and Methods Twenty-three controls (11 males and 12 females) and 13 patients (eight males and five females) volunteered to participate in the experiment. The patients underwent glossectomy surgery for T1 or T2 lateral lingual tumors. The speech tasks “a souk” and “a geese” were spoken by all subjects providing data for the vowels /u/ and /i/. Cine MRI and speech acoustics were recorded and measured to compare the changes in the tongue with vowel acoustics after surgery. 2D measurements were made of the interlip distance, tongue-palate distance, tongue position (anterior-posterior and superior-inferior), tongue height on the left and right sides, and pharynx size. Vowel formants Fl, F2, and F3 were measured. Results The patients had significantly lower F2/Fl ratios (F=5.911, p=0.018), and lower F3/F1 ratios that approached significance. This was seen primarily in the /u/ data. Patients had flatter tongue shapes than controls with a greater effect seen in /u/ than /i/. Conclusion The patients showed complex adaptation motion in order to preserve the acoustic integrity of the vowels, and the tongue modified cavity size relationships to maintain the value of the formant frequencies. PMID:27812617

  19. Electronic properties of CuPc and H2Pc: an experimental and theoretical study.

    PubMed

    Nardi, Marco Vittorio; Detto, Francesca; Aversa, Lucrezia; Verucchi, Roberto; Salviati, Giancarlo; Iannotta, Salvatore; Casarin, Maurizio

    2013-08-21

    Phthalocyanine (H2Pc) and its open-shell copper complex (CuPc) deposited on amorphous gold films have been studied by combining the outcomes of several synchrotron based spectroscopic tools (X-ray photoelectron spectroscopy, UV photoelectron spectroscopy and near-edge X-ray absorption fine structure, NEXAFS, spectroscopy) with those of density functional theory (DFT) calculations. The assignment of experimental evidence has been guided by the results of DFT numerical experiments carried out on isolated molecules. With specific reference to CuPc NEXAFS data collected at the N K-edge, they have been assigned by using the open-shell time-dependent DFT (TDDFT) in the framework of the zeroth order regular approximation (ZORA) scalar relativistic approach. The agreement between theory and experiment has been found to be satisfactory, thus indicating that the open-shell TDDFT (F. Wang and T. Ziegler, Mol. Phys., 2004, 102, 2585) may be used with some confidence to look into the X-ray absorption spectroscopy results pertinent to transition metal complexes. As far as the metal-ligand interaction is concerned, the combined use of NEXAFS spectroscopy and DFT outcomes ultimately testified the significant ionic contribution characterizing the bonding between the metal centre and the nitrogen atoms of the phthalocyanine coordinative pocket.

  20. A PC-based single-ADC multi-parameter data acquisition system

    SciTech Connect

    Woodring, M.; Kegel, G.H.R.; Egan, J.J.

    1995-10-01

    A personal computer (PC) based mult parameter data acquisition system using the Microsoft Window operating environment has been designed and constructed. An IBI AT compatible personal computer with an Intel 486DX5 microprocessor was combined with a National Instruments ATIDIO 32 digital I/O card, a single Canberra 8713 ADC with 13-bit resolution and a modified Canberra 8223 8-input analog multiplexer to acquil data from experiments carried out at the UML Van de Graa accelerator. The accelerator data acquisition (ADAC) computer environment was programmed in Microsoft Visual BASIC for use i Windows. ADAC allows event-mode data acquisition with up to eight parameters (modifiable to 64) and the simultaneous display parameters during acquisition. Additional features of ADAC include replay of event-mode data and graphical analysis/display of data. TV ADAC environment is easy to upgrade or expand, inexpensive 1 implement, and is specifically designed to meet the needs of nuclei spectroscopy.

  1. Inhibition of Prohormone Convertases PC1/3 and PC2 by 2,5-Dideoxystreptamine Derivatives

    PubMed Central

    Vivoli, Mirella; Caulfield, Thomas R.; Martínez-Mayorga, Karina; Johnson, Alan T.; Jiao, Guan-Sheng

    2012-01-01

    The prohormone convertases PC1/3 and PC2 are eukaryotic serine proteases involved in the proteolytic maturation of peptide hormone precursors and are implicated in a variety of pathological conditions, including obesity, diabetes, and neurodegenerative diseases. In this work, we screened 45 compounds obtained by derivatization of a 2,5-dideoxystreptamine scaffold with guanidinyl and aryl substitutions for convertase inhibition. We identified four promising PC1/3 competitive inhibitors and three PC2 inhibitors that exhibited various inhibition mechanisms (competitive, noncompetitive, and mixed), with sub- and low micromolar inhibitory potency against a fluorogenic substrate. Low micromolar concentrations of certain compounds blocked the processing of the physiological substrate proglucagon. The best PC2 inhibitor effectively inhibited glucagon synthesis, a known PC2-mediated process, in a pancreatic cell line; no cytotoxicity was observed. We also identified compounds that were able to stimulate both 87 kDa PC1/3 and PC2 activity, behavior related to the presence of aryl groups on the dideoxystreptamine scaffold. By contrast, inhibitory activity was associated with the presence of guanidinyl groups. Molecular modeling revealed interactions of the PC1/3 inhibitors with the active site that suggest structural modifications to further enhance potency. In support of kinetic data suggesting that PC2 inhibition probably occurs via an allosteric mechanism, we identified several possible allosteric binding sites using computational searches. It is noteworthy that one compound was found to both inhibit PC2 and stimulate PC1/3. Because glucagon acts in functional opposition to insulin in blood glucose homeostasis, blocking glucagon formation and enhancing proinsulin cleavage with a single compound could represent an attractive therapeutic approach in diabetes. PMID:22169851

  2. Quantification of PrPC in bovine peripheral tissues: Analysis in wild-type and PrPC-deficient cattle.

    PubMed

    Kobayashi, Shin-Ichi; Ano, Yasuhisa; Sakudo, Akikazu; Yukawa, Masayoshi; Sigiura, Katsuaki; Manabe, Noboru; Nakayama, Hiroyuki; Onodera, Takashi

    2009-01-01

    Cellular PrP (PrPC) is necessary for bovine spongiform encephalopathy (BSE) infection. The purpose of the present experiment was the quantification of PrPC in peripheral tissues to assess the risk of BSE infection from these tissues. The tissue distribution of PrPC was examined by a sandwich enzyme-linked immunosorbent assay (sELISA) and histochemical analysis. PrPC-deficient cows were used as a negative control. The sELISA revealed that the brain contained the highest PrPC content (10.7 µg/g tissue), while other organs/tissues harbored lower amounts, in decreasing order as follows: longissimus capitis muscle, iliocostalis thoracis muscle, splenius muscle, biceps femoris muscle, triceps brachii muscle, longissimus thoracis muscle, ileum, jejunum, duodenum, colon, cecum, apex linguae, omotransversarius muscle, posterior part of the corpus linguae, anterior part of the corpus linguae and radix linguae (5.2- to 31-fold less PrPC than the brain). In the tissue/organs of PrP-deficient cows, PrPC levels were under the limit of detection. Histochemical analysis showed that PrPC was expressed in nerve cells in intestinal tissues. The presence of PrPC in the bovine tongue, skeletal muscles and intestines raises the possibility of PrPSc accumulation in these tissues, indicating that these organs/tissues may serve as potential sources of BSE infection.

  3. Physical Properties of PC-PMMA Multilayers

    NASA Astrophysics Data System (ADS)

    Rahman, Arifur; Baer, Eric; Chipara, Alin Cristian; Vajtai, Robert; Ajayan, Pullickel M.; Hinthorne, James; Elamin, Ibrahim; Chipara, Mircea; Eric Baer Collaboration; Pullickel Ajayan Collaboration; Mircea Chipara Collaboration

    2015-03-01

    Multilayers of polycarbonate (PC) and polymethylmethacrylate (PMMA) have been obtained by the layer multiplying coextrusion method. Each sample (1024 layers, of equal thickness, with individual thickness between 10 and 200 nm) has been investigated at room temperature by Wide Angle X-Ray Scattering (WAXS) using a Bruker Discovery 8 spectrometer (Cu K α radiation), Raman spectroscopy (Bruker Senterra confocal Raman spectrometer operating at 785 nm), FTIR spectroscopy (Tensor 27 Bruker), and UV-Vis spectroscopy. Further details about the glass transition temperature in these samples have been obtained by Dynamical Mechanical Analysis, DMA, (TA Instruments Q800) at various frequencies in the range 1 to 100 Hz. Isothermal Differential Scanning Calorimetry, DSC, (TA Instruments Q200) was used to investigate the effect of the thickness of the polymeric film on the crystallization processes. Non-isothermal DSC measurements aimed at the identification and location of the main phase transitions (glass, crystallization, and melting) occurring in these multilayers. The effects of confinement on the phase transitions occurring in these multilayers are discussed in detail.

  4. Pc-Based Floating Point Imaging Workstation

    NASA Astrophysics Data System (ADS)

    Guzak, Chris J.; Pier, Richard M.; Chinn, Patty; Kim, Yongmin

    1989-07-01

    The medical, military, scientific and industrial communities have come to rely on imaging and computer graphics for solutions to many types of problems. Systems based on imaging technology are used to acquire and process images, and analyze and extract data from images that would otherwise be of little use. Images can be transformed and enhanced to reveal detail and meaning that would go undetected without imaging techniques. The success of imaging has increased the demand for faster and less expensive imaging systems and as these systems become available, more and more applications are discovered and more demands are made. From the designer's perspective the challenge to meet these demands forces him to attack the problem of imaging from a different perspective. The computing demands of imaging algorithms must be balanced against the desire for affordability and flexibility. Systems must be flexible and easy to use, ready for current applications but at the same time anticipating new, unthought of uses. Here at the University of Washington Image Processing Systems Lab (IPSL) we are focusing our attention on imaging and graphics systems that implement imaging algorithms for use in an interactive environment. We have developed a PC-based imaging workstation with the goal to provide powerful and flexible, floating point processing capabilities, along with graphics functions in an affordable package suitable for diverse environments and many applications.

  5. Attention selection, distractor suppression and N2pc.

    PubMed

    Mazza, Veronica; Turatto, Massimo; Caramazza, Alfonso

    2009-01-01

    N2pc is generally interpreted as the electrocortical correlate of the distractor-suppression mechanisms through which attention selection takes place in humans. Here, we present data that challenge this common N2pc interpretation. In Experiment 1, multiple distractors induced greater N2pc amplitudes even when they facilitated target identification, despite the suppression account of the N2pc predicted the contrary; in Experiment 2, spatial proximity between target and distractors did not affect the N2pc amplitude, despite resulting in more interference in response times; in Experiment 3, heterogeneous distractors delayed response times but did not elicit a greater N2pc relative to homogeneous distractors again in contrast with what would have predicted the suppression hypothesis. These results do not support the notion that the N2pc unequivocally mirrors distractor-suppression processes. We propose that the N2pc indexes mechanisms involved in identifying and localizing relevant stimuli in the scene through enhancement of their features and not suppression of distractors.

  6. PC2 Ovotransferrin: Characterization and Alternative Immunotherapeutic Activity

    PubMed Central

    Chiurciu, Constantin; Chiurciu, Viorica; Oporanu, Mariana; Pătrașcu, Ionel Victor; Mihai, Iuliana; Tablică, Mădălina

    2017-01-01

    Characterization and evaluation of immunotherapeutic potential of ovotransferrin PC2 (OTf PC2) were performed in this study. The ovoprotein was obtained from egg white from hens immunized with bacterial antigens, pathogenic for humans. For the negative control samples, OTf was extracted from eggs collected from Specific Pathogen-Free (SPF) hens and purified by affinity chromatography on Protein G-agarose column with two eluting peaks: I, representing ovalbumin, and II, ovotransferrin. The final apo-OTf form was reached by successive precipitation with ammonium sulfate and citric acid and the holo-OTf form by saturating the apo-form with FeCl3. Multiple OTf PC2 samples were analyzed through Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and, based on the molecular marker migration model, the ovotransferrin (76.5 kDa) and ovalbumin (45 kDa) were detected. The agglutination reaction exhibited statistically significant high specificity of the multiple OTf PC2, by reacting with the antigens used for hens' immunization. Following ELISA, it was established that OTf PC2 from hyperimmune eggs has specificity for all antigens; the antibody titer was high, indicating that OTf PC2 possesses immunological properties similar to immunoglobulin Y (Ig Y). This study suggests that OTf PC2 immunological activity may play a crucial role in the prevention and treatment of infections resistant to antibiotics and OTf PC2 can also act as a valuable nutraceutical.

  7. Chromosomal Distribution of PcG Proteins during Drosophila Development

    PubMed Central

    Nègre, Nicolas; Hennetin, Jérôme; Sun, Ling V; Lavrov, Sergey; Bellis, Michel; White, Kevin P

    2006-01-01

    Polycomb group (PcG) proteins are able to maintain the memory of silent transcriptional states of homeotic genes throughout development. In Drosophila, they form multimeric complexes that bind to specific DNA regulatory elements named PcG response elements (PREs). To date, few PREs have been identified and the chromosomal distribution of PcG proteins during development is unknown. We used chromatin immunoprecipitation (ChIP) with genomic tiling path microarrays to analyze the binding profile of the PcG proteins Polycomb (PC) and Polyhomeotic (PH) across 10 Mb of euchromatin. We also analyzed the distribution of GAGA factor (GAF), a sequence-specific DNA binding protein that is found at most previously identified PREs. Our data show that PC and PH often bind to clustered regions within large loci that encode transcription factors which play multiple roles in developmental patterning and in the regulation of cell proliferation. GAF co-localizes with PC and PH to a limited extent, suggesting that GAF is not a necessary component of chromatin at PREs. Finally, the chromosome-association profile of PC and PH changes during development, suggesting that the function of these proteins in the regulation of some of their target genes might be more dynamic than previously anticipated. PMID:16613483

  8. Hydrogen bonds in PC{sub 61}BM solids

    SciTech Connect

    Sheng, Chun-Qi; Li, Wen-Jie; Du, Ying-Ying; Chen, Guang-Hua; Chen, Zheng; Li, Hai-Yang; Li, Hong-Nian

    2015-09-15

    We have studied the hydrogen bonds in PC{sub 61}BM solids. Inter-molecular interaction is analyzed theoretically for the well-defined monoclinic (P2{sub 1}/n) structure. The results indicate that PC{sub 61}BM combines into C–H⋯O{sub d} bonded molecular chains, where O{sub d} denotes the doubly-bonded O atom of PC{sub 61}BM. The molecular chains are linked together by C–H⋯O{sub s} bonds, where O{sub s} denotes the singly-bonded O atom of PC{sub 61}BM. To reveal the consequences of hydrogen bond formation on the structural properties of PC{sub 61}BM solids (not limited to the monoclinic structure), we design and perform some experiments for annealed samples with the monoclinic (P2{sub 1}/n) PC{sub 61}BM as starting material. The experiments include differential scanning calorimetry, X-ray diffraction and infrared absorption measurements. Structural phase transitions are observed below the melting point. The C–H⋯O{sub d} bonds seem persisting in the altered structures. The inter-molecular hydrogen bonds can help to understand the phase separation in polymer/PC{sub 61}BM blends and may be responsible for the existence of liquid PC{sub 61}BM.

  9. PrPC from stem cells to cancer

    PubMed Central

    Martin-Lannerée, Séverine; Hirsch, Théo Z.; Hernandez-Rapp, Julia; Halliez, Sophie; Vilotte, Jean-Luc; Launay, Jean-Marie; Mouillet-Richard, Sophie

    2014-01-01

    The cellular prion protein PrPC was initially discovered as the normal counterpart of the pathological scrapie prion protein PrPSc, the main component of the infectious agent of Transmissible Spongiform Encephalopathies. While clues as to the physiological function of this ubiquitous protein were greatly anticipated from the development of knockout animals, PrP-null mice turned out to be viable and to develop without major phenotypic abnormalities. Notwithstanding, the discovery that hematopoietic stem cells from PrP-null mice have impaired long-term repopulating potential has set the stage for investigating into the role of PrPC in stem cell biology. A wealth of data have now exemplified that PrPC is expressed in distinct types of stem cells and regulates their self-renewal as well as their differentiation potential. A role for PrPC in the fate restriction of embryonic stem cells has further been proposed. Paralleling these observations, an overexpression of PrPC has been documented in various types of tumors. In line with the contribution of PrPC to stemness and to the proliferation of cancer cells, PrPC was recently found to be enriched in subpopulations of tumor-initiating cells. In the present review, we summarize the current knowledge of the role played by PrPC in stem cell biology and discuss how the subversion of its function may contribute to cancer progression. PMID:25364760

  10. Transforming PC Power Supplies into Smart Car Battery Conditioners

    ERIC Educational Resources Information Center

    Rodriguez-Ascariz, J. M.; Boquete-Vazquez, L.

    2011-01-01

    This paper describes a laboratory project consisting of a PC power supply modification into an intelligent car-battery conditioner with both wireless and wired networking capabilities. Adding a microcontroller to an average PC power supply transforms it into a flexible, intelligent device that can be configured and that is suitable to keep car…

  11. A novel technique for VMAT QA with EPID in cine mode on a Varian TrueBeam linac

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Adamson, Justus; Rodrigues, Anna; Zhou, Fugen; Yin, Fang-fang; Wu, Qiuwen

    2013-10-01

    Volumetric modulated arc therapy (VMAT) is a relatively new treatment modality for dynamic photon radiation therapy. Pre-treatment quality assurance (QA) is necessary and many efforts have been made to apply electronic portal imaging device (EPID)-based IMRT QA methods to VMAT. It is important to verify the gantry rotation speed during delivery as this is a new variable that is also modulated in VMAT. In this paper, we present a new technique to perform VMAT QA using an EPID. The method utilizes EPID cine mode and was tested on Varian TrueBeam in research mode. The cine images were acquired during delivery and converted to dose matrices after profile correction and dose calibration. A sub-arc corresponding to each cine image was extracted from the original plan and its portal image prediction was calculated. Several analyses were performed including 3D γ analysis (2D images + gantry angle axis), 2D γ analysis, and other statistical analyses. The method was applied to 21 VMAT photon plans of 3 photon energies. The accuracy of the cine image information was investigated. Furthermore, this method's sensitivity to machine delivery errors was studied. The pass rate (92.8 ± 1.4%) for 3D γ analysis was comparable to those from Delta4 system (99.9 ± 0.1%) under similar criteria (3%, 3 mm, 5% threshold and 2° angle to agreement) at 6 MV. The recorded gantry angle and start/stop MUs were found to have sufficient accuracy for clinical QA. Machine delivery errors can be detected through combined analyses of 3D γ, gantry angle, and percentage dose difference. In summary, we have developed and validated a QA technique that can simultaneously verify the gantry angle and delivered MLC fluence for VMAT treatment.This technique is efficient and its accuracy is comparable to other QA methods.

  12. Real-time cine and myocardial perfusion with treadmill exercise stress cardiovascular magnetic resonance in patients referred for stress SPECT

    PubMed Central

    2010-01-01

    Background To date, stress cardiovascular magnetic resonance (CMR) has relied on pharmacologic agents, and therefore lacked the physiologic information available only with exercise stress. Methods 43 patients age 25 to 81 years underwent a treadmill stress test incorporating both Tc99m SPECT and CMR. After rest Tc99m SPECT imaging, patients underwent resting cine CMR. Patients then underwent in-room exercise stress using a partially modified treadmill. 12-lead ECG monitoring was performed throughout. At peak stress, Tc99m was injected and patients rapidly returned to their prior position in the magnet for post-exercise cine and perfusion imaging. The patient table was pulled out of the magnet for recovery monitoring. The patient was sent back into the magnet for recovery cine and resting perfusion followed by delayed post-gadolinium imaging. Post-CMR, patients went to the adjacent SPECT lab to complete stress nuclear imaging. Each modality's images were reviewed blinded to the other's results. Results Patients completed on average 9.3 ± 2.4 min of the Bruce protocol. Stress cine CMR was completed in 68 ± 14 sec following termination of exercise, and stress perfusion CMR was completed in 88 ± 8 sec. Agreement between SPECT and CMR was moderate (κ = 0.58). Accuracy in eight patients who underwent coronary angiography was 7/8 for CMR and 5/8 for SPECT (p = 0.625). Follow-up at 6 months indicated freedom from cardiovascular events in 29/29 CMR-negative and 33/34 SPECT-negative patients. Conclusions Exercise stress CMR including wall motion and perfusion is feasible in patients with suspected ischemic heart disease. Larger clinical trials are warranted based on the promising results of this pilot study to allow comparative effectiveness studies of this stress imaging system vs. other stress imaging modalities. PMID:20624294

  13. Monte Carlo tests of the ELIPGRID-PC algorithm

    SciTech Connect

    Davidson, J.R.

    1995-04-01

    The standard tool for calculating the probability of detecting pockets of contamination called hot spots has been the ELIPGRID computer code of Singer and Wickman. The ELIPGRID-PC program has recently made this algorithm available for an IBM{reg_sign} PC. However, no known independent validation of the ELIPGRID algorithm exists. This document describes a Monte Carlo simulation-based validation of a modified version of the ELIPGRID-PC code. The modified ELIPGRID-PC code is shown to match Monte Carlo-calculated hot-spot detection probabilities to within {plus_minus}0.5% for 319 out of 320 test cases. The one exception, a very thin elliptical hot spot located within a rectangular sampling grid, differed from the Monte Carlo-calculated probability by about 1%. These results provide confidence in the ability of the modified ELIPGRID-PC code to accurately predict hot-spot detection probabilities within an acceptable range of error.

  14. 3D cine magnetic resonance imaging of rat lung ARDS using gradient-modulated SWIFT with retrospective respiratory gating

    NASA Astrophysics Data System (ADS)

    Kobayashi, Naoharu; Lei, Jianxun; Utecht, Lynn; Garwood, Michael; Ingbar, David H.; Bhargava, Maneesh

    2015-03-01

    SWeep Imaging with Fourier Transformation (SWIFT) with gradient modulation and DC navigator retrospective gating is introduced as a 3D cine magnetic resonance imaging (MRI) method for the lung. In anesthetized normal rats, the quasi-simultaneous excitation and acquisition in SWIFT enabled extremely high sensitivity to the fast-decaying parenchymal signals (TE=~4 μs), which are invisible with conventional MRI techniques. Respiratory motion information was extracted from DC navigator signals and the SWIFT data were reconstructed to 3D cine images with 16 respiratory phases. To test this technique's capabilities, rats exposed to > 95% O2 for 60 hours for induction of acute respiratory distress syndrome (ARDS), were imaged and compared with normal rat lungs (N=7 and 5 for ARDS and normal groups, respectively). SWIFT images showed lung tissue density differences along the gravity direction. In the cine SWIFT images, a parenchymal signal drop at the inhalation phase was consistently observed for both normal and ARDS rats due to lung inflation (i.e. decrease of the proton density), but the drop was less for ARDS rats. Depending on the respiratory phase and lung region, the lungs from the ARDS rats showed 1-24% higher parenchymal signal intensities relative to the normal rat lungs, likely due to accumulated extravascular water (EVLW). Those results demonstrate that SWIFT has high enough sensitivity for detecting the lung proton density changes due to gravity, different phases of respiration and accumulation of EVLW in the rat ARDS lungs.

  15. Evaluation of a motion artifacts removal approach on breath-hold cine-magnetic resonance images of hypertrophic cardiomyopathy subjects

    NASA Astrophysics Data System (ADS)

    Betancur, Julián.; Simon, Antoine; Schnell, Frédéric; Donal, Erwan; Hernández, Alfredo; Garreau, Mireille

    2013-11-01

    The acquisition of ECG-gated cine magnetic resonance images of the heart is routinely performed in apnea in order to suppress the motion artifacts caused by breathing. However, many factors including the 2D nature of the acquisition and the use of di erent beats to acquire the multiple-view cine images, cause this kind of artifacts to appear. This paper presents the qualitative evaluation of a method aiming to remove motion artifacts in multipleview cine images acquired on patients with hypertrophic cardiomyopathy diagnosis. The approach uses iconic registration to reduce for in-plane artifacts in long-axis-view image stacks and in-plane and out-of-plane motion artifacts in sort-axis-view image stack. Four similarity measures were evaluated: the normalized correlation, the normalized mutual information, the sum of absolute voxel di erences and the Slomka metric proposed by Slomka et al. The qualitative evaluation assessed the misalignment of di erent anatomical structures of the left ventricle as follows: the misalignment of the interventricular septum and the lateral wall for short-axis-view acquisitions and the misalignment between the short-axis-view image and long-axis-view images. Results showed the correction using the normalized correlation as the most appropriated with an 80% of success.

  16. Joint multi-object registration and segmentation of left and right cardiac ventricles in 4D cine MRI

    NASA Astrophysics Data System (ADS)

    Ehrhardt, Jan; Kepp, Timo; Schmidt-Richberg, Alexander; Handels, Heinz

    2014-03-01

    The diagnosis of cardiac function based on cine MRI requires the segmentation of cardiac structures in the images, but the problem of automatic cardiac segmentation is still open, due to the imaging characteristics of cardiac MR images and the anatomical variability of the heart. In this paper, we present a variational framework for joint segmentation and registration of multiple structures of the heart. To enable the simultaneous segmentation and registration of multiple objects, a shape prior term is introduced into a region competition approach for multi-object level set segmentation. The proposed algorithm is applied for simultaneous segmentation of the myocardium as well as the left and right ventricular blood pool in short axis cine MRI images. Two experiments are performed: first, intra-patient 4D segmentation with a given initial segmentation for one time-point in a 4D sequence, and second, a multi-atlas segmentation strategy is applied to unseen patient data. Evaluation of segmentation accuracy is done by overlap coefficients and surface distances. An evaluation based on clinical 4D cine MRI images of 25 patients shows the benefit of the combined approach compared to sole registration and sole segmentation.

  17. 3D Cine Magnetic Resonance Imaging of Rat Lung ARDS using Gradient-modulated SWIFT with Retrospective Respiratory Gating.

    PubMed

    Kobayashi, Naoharu; Lei, Jianxun; Utecht, Lynn; Garwood, Michael; Ingbar, David; Bhargava, Maneesh

    2015-02-21

    SWeep Imaging with Fourier Transformation (SWIFT) with gradient modulation and DC navigator retrospective gating is introduced as a 3D cine magnetic resonance imaging (MRI) method for the lung. The quasi-simultaneous excitation and acquisition in SWIFT enabled extremely high sensitivity to the fast-decaying parenchymal signals (TE=~4 μs), which are invisible with conventional MRI techniques. Based on respiratory motion information extracted from DC navigator signals, the SWIFT data were reconstructed to 3D cine images with 16 respiratory phases. To test the capability of the proposed technique, rats exposed to > 95% O2 for 60 hours for induction of acute respiratory distress syndrome (ARDS), were imaged and compared with normal rat lungs (N=7 and 5 for ARDS and normal group, respectively). SWIFT images showed lung tissue density difference along the gravity direction. In the cine SWIFT images, parenchymal signal drop at the inhalation phase was consistently observed for both normal and ARDS rats due to inflation of the lung (i.e. decrease of the proton density), but the drop was less for ARDS rats. Depending on the respiration phase and lung region, the lungs from the ARDS rats showed 1-24% higher parenchymal signal intensities relative to the normal rat lungs, which would be mainly from accumulation of extravascular water (EVLW). Those results demonstrate that SWIFT has high enough sensitivity for detecting the lung proton density changes due to gravity, different respiration phases and accumulation of EVLW in the rat ARDS lungs.

  18. Future accelerator technology

    SciTech Connect

    Sessler, A.M.

    1986-05-01

    A general discussion is presented of the acceleration of particles. Upon this foundation is built a categorization scheme into which all accelerators can be placed. Special attention is devoted to accelerators which employ a wake-field mechanism and a restricting theorem is examined. It is shown how the theorem may be circumvented. Comments are made on various acceleration schemes.

  19. ACCELERATION AND THE GIFTED.

    ERIC Educational Resources Information Center

    GIBSON, ARTHUR R.; STEPHANS, THOMAS M.

    ACCELERATION OF PUPILS AND SUBJECTS IS CONSIDERED A MEANS OF EDUCATING THE ACADEMICALLY GIFTED STUDENT. FIVE INTRODUCTORY ARTICLES PROVIDE A FRAMEWORK FOR THINKING ABOUT ACCELERATION. FIVE PROJECT REPORTS OF ACCELERATED PROGRAMS IN OHIO ARE INCLUDED. ACCELERATION IS NOW BEING REGARDED MORE FAVORABLY THAN FORMERLY, BECAUSE METHODS HAVE BEEN…

  20. Laser driven ion accelerator

    DOEpatents

    Tajima, Toshiki

    2005-06-14

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  1. Laser driven ion accelerator

    DOEpatents

    Tajima, Toshiki

    2006-04-18

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  2. PC viruses: How do they do that

    SciTech Connect

    Pichnarczyk, K.

    1992-07-01

    The topic of PC Viruses has been an issue for a number of years now. They've been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

  3. PC viruses: How do they do that?

    SciTech Connect

    Pichnarczyk, K.

    1992-07-01

    The topic of PC Viruses has been an issue for a number of years now. They`ve been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

  4. Run-09 pC polarimeter analysis

    SciTech Connect

    Alekseev, I.; Aschenauer, E.; Atoyan, G.; Bazilevsky, A.; Gill, R.; Huang, H.; Lee, S.; Li, X.; Makdisi, Y.; Morozov, B.; Nakagawa, I.; Svirida, D.; Zelenski, A.

    2010-08-01

    Analysis of PC polarimeter data at {radical}s = 200 and 500 GeV from Run9 is presented. Final polarization results, fill-by-fill, for blue and yellow beams, as to be used by RHIC experiments (in collisions) are released and collected in http://www4.rcf.bnl.gov/cnipol/pubdocs/Run09Offline/. Global relative systematic uncertainties {delta}P/P (to be considered as correlated from fill to fill) are 4.7% for 100 GeV beams, and 8.3% (12.1%) for blue (yellow) 250 GeV beams. For a product of two beam polarizations P{sub B} {center_dot} P{sub Y} (used in double spin asymmetry measurements) the relative uncertainty {delta}(P{sub B} {center_dot} P{sub Y})/(P{sub B} {center_dot} P{sub Y}) 8.8% for 100 GeV beams and 18.5% for 250 GeV beams. For the average between two beam polarization (P{sub B} + P{sub Y})/2 (used in single spin asymmetry measurements, when data from two polarized beams are combined) the relative uncertainty is 4.4% for 100 GeV beams and 9.2% for 250 GeV beams. Larger uncertainties for 250 GeV beams relate to significant rate related systematic effects experienced in the first part of Run9 (due to thicker targets used and smaller trans. beam size at higher beam energy).

  5. HOTSPOT Health Physics codes for the PC

    SciTech Connect

    Homann, S.G.

    1994-03-01

    The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculation tool for evaluating accidents involving radioactive materials. HOTSPOT codes are a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. HOTSPOT programs are reasonably accurate for a timely initial assessment. More importantly, HOTSPOT codes produce a consistent output for the same input assumptions and minimize the probability of errors associated with reading a graph incorrectly or scaling a universal nomogram during an emergency. The HOTSPOT codes are designed for short-term (less than 24 hours) release durations. Users requiring radiological release consequences for release scenarios over a longer time period, e.g., annual windrose data, are directed to such long-term models as CAPP88-PC (Parks, 1992). Users requiring more sophisticated modeling capabilities, e.g., complex terrain; multi-location real-time wind field data; etc., are directed to such capabilities as the Department of Energy`s ARAC computer codes (Sullivan, 1993). Four general programs -- Plume, Explosion, Fire, and Resuspension -- calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosive release, fuel fire, or an area contamination event. Other programs deal with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. Additional programs estimate the dose commitment from the inhalation of any one of the radionuclides listed in the database of radionuclides; calibrate a radiation survey instrument for ground-survey measurements; and screen plutonium uptake in the lung (see FIDLER Calibration and LUNG Screening sections).

  6. Accelerated Adaptive MGS Phase Retrieval

    NASA Technical Reports Server (NTRS)

    Lam, Raymond K.; Ohara, Catherine M.; Green, Joseph J.; Bikkannavar, Siddarayappa A.; Basinger, Scott A.; Redding, David C.; Shi, Fang

    2011-01-01

    The Modified Gerchberg-Saxton (MGS) algorithm is an image-based wavefront-sensing method that can turn any science instrument focal plane into a wavefront sensor. MGS characterizes optical systems by estimating the wavefront errors in the exit pupil using only intensity images of a star or other point source of light. This innovative implementation of MGS significantly accelerates the MGS phase retrieval algorithm by using stream-processing hardware on conventional graphics cards. Stream processing is a relatively new, yet powerful, paradigm to allow parallel processing of certain applications that apply single instructions to multiple data (SIMD). These stream processors are designed specifically to support large-scale parallel computing on a single graphics chip. Computationally intensive algorithms, such as the Fast Fourier Transform (FFT), are particularly well suited for this computing environment. This high-speed version of MGS exploits commercially available hardware to accomplish the same objective in a fraction of the original time. The exploit involves performing matrix calculations in nVidia graphic cards. The graphical processor unit (GPU) is hardware that is specialized for computationally intensive, highly parallel computation. From the software perspective, a parallel programming model is used, called CUDA, to transparently scale multicore parallelism in hardware. This technology gives computationally intensive applications access to the processing power of the nVidia GPUs through a C/C++ programming interface. The AAMGS (Accelerated Adaptive MGS) software takes advantage of these advanced technologies, to accelerate the optical phase error characterization. With a single PC that contains four nVidia GTX-280 graphic cards, the new implementation can process four images simultaneously to produce a JWST (James Webb Space Telescope) wavefront measurement 60 times faster than the previous code.

  7. Internal margin assessment using cine MRI analysis of deglutition in head and neck cancer radiotherapy

    SciTech Connect

    Paulson, Eric S.; Bradley, Julie A.; Wang Dian; Ahunbay, Ergun E.; Schultz, Christoper; Li, X. Allen

    2011-04-15

    Purpose: Intensity-modulated radiation therapy (IMRT) is a promising treatment modality for patients with head and neck cancer (HNC). The dose distributions from IMRT are static and, thus, are unable to account for variations and/or uncertainties in the relationship between the patient (region being treated) and the beam. Organ motion comprises one such source of this uncertainty, introduced by physiological variation in the position, size, and shape of organs during treatment. In the head and neck, the predominant source of this variation arises from deglutition (swallowing). The purpose of this study was to investigate whether cinematographic MRI (cine MRI) could be used to determine asymmetric (nonuniform) internal margin (IM) components of tumor planning target volumes based on the actual deglutition-induced tumor displacement. Methods: Five head and neck cancer patients were set up in treatment position on a 3 T MRI scanner. Two time series of single-slice, sagittal, cine images were acquired using a 2D FLASH sequence. The first time series was a 12.8 min scan designed to capture the frequency and duration of deglutition in the treatment position. The second time series was a short, 15 s scan designed to capture the displacement of deglutition in the treatment position. Deglutition frequency and mean swallow duration were estimated from the long time series acquisition. Swallowing and resting (nonswallowing) events were identified on the short time series acquisition and displacement was estimated based on contours of gross tumor volume (GTV) generated at each time point of a particular event. A simple linear relationship was derived to estimate 1D asymmetric IMs in the presence of resting- and deglutition-induced displacement. Results: Deglutition was nonperiodic, with frequency and duration ranging from 2.89-24.18 mHz and from 3.86 to 6.10 s, respectively. The deglutition frequency and mean duration were found to vary among patients. Deglutition

  8. ISTUM PC: industrial sector technology use model for the IBM-PC

    SciTech Connect

    Roop, J.M.; Kaplan, D.T.

    1984-09-01

    A project to improve and enhance the Industrial Sector Technology Use Model (ISTUM) was originated in the summer of 1983. The project had dix identifiable objectives: update the data base; improve run-time efficiency; revise the reference base case; conduct case studies; provide technical and promotional seminars; and organize a service bureau. This interim report describes which of these objectives have been met and which tasks remain to be completed. The most dramatic achievement has been in the area of run-time efficiency. From a model that required a large proportion of the total resources of a mainframe computer and a great deal of effort to operate, the current version of the model (ISTUM-PC) runs on an IBM Personal Computer. The reorganization required for the model to run on a PC has additional advantages: the modular programs are somewhat easier to understand and the data base is more accessible and easier to use. A simple description of the logic of the model is given in this report. To generate the necessary funds for completion of the model, a multiclient project is proposed. This project will extend the industry coverage to all the industrial sectors, including the construction of process flow models for chemicals and petroleum refining. The project will also calibrate this model to historical data and construct a base case and alternative scenarios. The model will be delivered to clients and training provided. 2 references, 4 figures, 3 tables.

  9. Craniocaudal Safety Margin Calculation Based on Interfractional Changes in Tumor Motion in Lung SBRT Assessed With an EPID in Cine Mode

    SciTech Connect

    Ueda, Yoshihiro; Miyazaki, Masayoshi; Nishiyama, Kinji; Suzuki, Osamu; Tsujii, Katsutomo; Miyagi, Ken

    2012-07-01

    Purpose: To evaluate setup error and interfractional changes in tumor motion magnitude using an electric portal imaging device in cine mode (EPID cine) during the course of stereotactic body radiation therapy (SBRT) for non-small-cell lung cancer (NSCLC) and to calculate margins to compensate for these variations. Materials and Methods: Subjects were 28 patients with Stage I NSCLC who underwent SBRT. Respiratory-correlated four-dimensional computed tomography (4D-CT) at simulation was binned into 10 respiratory phases, which provided average intensity projection CT data sets (AIP). On 4D-CT, peak-to-peak motion of the tumor (M-4DCT) in the craniocaudal direction was assessed and the tumor center (mean tumor position [MTP]) of the AIP (MTP-4DCT) was determined. At treatment, the tumor on cone beam CT was registered to that on AIP for patient setup. During three sessions of irradiation, peak-to-peak motion of the tumor (M-cine) and the mean tumor position (MTP-cine) were obtained using EPID cine and in-house software. Based on changes in tumor motion magnitude ( Increment M) and patient setup error ( Increment MTP), defined as differences between M-4DCT and M-cine and between MTP-4DCT and MTP-cine, a margin to compensate for these variations was calculated with Stroom's formula. Results: The means ({+-}standard deviation: SD) of M-4DCT and M-cine were 3.1 ({+-}3.4) and 4.0 ({+-}3.6) mm, respectively. The means ({+-}SD) of Increment M and Increment MTP were 0.9 ({+-}1.3) and 0.2 ({+-}2.4) mm, respectively. Internal target volume-planning target volume (ITV-PTV) margins to compensate for Increment M, Increment MTP, and both combined were 3.7, 5.2, and 6.4 mm, respectively. Conclusion: EPID cine is a useful modality for assessing interfractional variations of tumor motion. The ITV-PTV margins to compensate for these variations can be calculated.

  10. The impact of cine EPID image acquisition frame rate on markerless soft-tissue tracking

    SciTech Connect

    Yip, Stephen Rottmann, Joerg; Berbeco, Ross

    2014-06-15

    Purpose: Although reduction of the cine electronic portal imaging device (EPID) acquisition frame rate through multiple frame averaging may reduce hardware memory burden and decrease image noise, it can hinder the continuity of soft-tissue motion leading to poor autotracking results. The impact of motion blurring and image noise on the tracking performance was investigated. Methods: Phantom and patient images were acquired at a frame rate of 12.87 Hz with an amorphous silicon portal imager (AS1000, Varian Medical Systems, Palo Alto, CA). The maximum frame rate of 12.87 Hz is imposed by the EPID. Low frame rate images were obtained by continuous frame averaging. A previously validated tracking algorithm was employed for autotracking. The difference between the programmed and autotracked positions of a Las Vegas phantom moving in the superior-inferior direction defined the tracking error (δ). Motion blurring was assessed by measuring the area change of the circle with the greatest depth. Additionally, lung tumors on 1747 frames acquired at 11 field angles from four radiotherapy patients are manually and automatically tracked with varying frame averaging. δ was defined by the position difference of the two tracking methods. Image noise was defined as the standard deviation of the background intensity. Motion blurring and image noise are correlated with δ using Pearson correlation coefficient (R). Results: For both phantom and patient studies, the autotracking errors increased at frame rates lower than 4.29 Hz. Above 4.29 Hz, changes in errors were negligible withδ < 1.60 mm. Motion blurring and image noise were observed to increase and decrease with frame averaging, respectively. Motion blurring and tracking errors were significantly correlated for the phantom (R = 0.94) and patient studies (R = 0.72). Moderate to poor correlation was found between image noise and tracking error with R −0.58 and −0.19 for both studies, respectively. Conclusions: Cine EPID

  11. Peak flow velocities in the ascending aorta-real-time phase-contrast magnetic resonance imaging vs. cine magnetic resonance imaging and echocardiography.

    PubMed

    Sohns, Jan M; Kowallick, Johannes T; Joseph, Arun A; Merboldt, K Dietmar; Voit, Dirk; Fasshauer, Martin; Staab, Wieland; Frahm, Jens; Lotz, Joachim; Unterberg-Buchwald, Christina

    2015-10-01

    This prospective study of eight healthy volunteers evaluates peak flow velocities (PFV) in the ascending aorta using real-time phase-contrast magnetic resonance imaging (MRI) in comparison to cine phase-contrast MRI and echocardiography. Flow measurements by echocardiography and cine phase-contrast MRI with breath-holding were performed according to clinical standards. Real-time phase-contrast MRI at 40 ms temporal resolution and 1.3 mm in-plane resolution was based on highly undersampled radial fast low-angle shot (FLASH) sequences with image reconstruction by regularized nonlinear inversion (NLINV). Evaluations focused on the determination of PFV. Linear regressions and Bland-Altman plots were used for comparisons of methods. When averaged across subjects, real-time phase-contrast MRI resulted in PFV of 120±20 cm s(-1) (mean ± SD) in comparison to 122±16 cm s(-1) for cine MRI and 124±20 cm s(-1) for echocardiography. The maximum deviations between real-time phase-contrast MRI and echocardiography ranged from -20 to +14 cm s(-1) (cine MRI: -10 to +12 cm s(-1)). Thus, in general, real-time phase-contrast MRI of cardiac outflow revealed quantitative agreement with cine MRI and echocardiography. The advantages of real-time MRI are measurements during free breathing and access to individual cardiac cycles.

  12. Impact of Surgical Evaluation of Additional Cine Magnetic Resonance Imaging for Advanced Thymoma with Infiltration of Adjacent Structures: The Thoracic Surgeon's View.

    PubMed

    Ried, Michael; Hnevkovsky, Stefanie; Neu, Reiner; von Süßkind-Schwendi, Marietta; Götz, Andrea; Hamer, Okka W; Schalke, Berthold; Hofmann, Hans-Stefan

    2017-04-01

    Background Preoperative radiological assessment is important for clarification of surgical operability for advanced thymic tumors. Objective was to determine the feasibility of magnetic resonance imaging (MRI) with cine sequences for evaluation of cardiovascular tumor invasion. Patients and Methods This prospective study included patients with advanced thymoma, who underwent surgical resection. All patients received preoperative computed tomography (CT) scan and cine MRI. Results Tumor infiltration was surgically confirmed in the pericardium (n = 12), myocardium (n = 1), superior caval vein (SCV; n = 3), and aorta (n = 2). A macroscopic complete resection was possible in 10 patients, whereas 2 patients with aortic or myocardial tumor invasion had R2 resection. The positive predictive value (PPV) was 50% for cine MRI compared with 0% for CT scan regarding myocardial tumor infiltration. The PPV for tumor infiltration of the aorta was 50%, with a higher sensitivity for the CT scan (100 vs. 50%). Infiltration of the SCV could be detected slightly better with cine MRI (PPV 75 vs. 66.7%). Conclusion Cine MRI seems to improve the accuracy of preoperative staging of advanced thymoma regarding infiltration of cardiovascular structures and supports the surgical approach.

  13. PC-SPES (PDQ®)—Health Professional Version

    Cancer.gov

    Expert-reviewed information summary about the use of PC-SPES as a treatment for prostate cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  14. OCEAN-PC and a distributed network for ocean data

    NASA Technical Reports Server (NTRS)

    Mclain, Douglas R.

    1992-01-01

    The Intergovernmental Oceanographic Commission (IOC) wishes to develop an integrated software package for oceanographic data entry and access in developing countries. The software, called 'OCEAN-PC', would run on low cost PC microcomputers and would encourage and standardize: (1) entry of local ocean observations; (2) quality control of the local data; (3) merging local data with historical data; (4) improved display and analysis of the merged data; and (5) international data exchange. OCEAN-PC will link existing MS-DOS oceanographic programs and data sets with table-driven format conversions. Since many ocean data sets are now being distributed on optical discs (Compact Discs - Read Only Memory, CD-ROM, Mass et al. 1987), OCEAN-PC will emphasize access to CD-ROMs.

  15. PC-SPES (PDQ®)—Patient Version

    Cancer.gov

    Expert-reviewed information summary about the use of PC-SPES as a treatment for prostate cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  16. Software Reviews. PC Software for Artificial Intelligence Applications.

    ERIC Educational Resources Information Center

    Epp, Helmut; And Others

    1988-01-01

    Contrasts artificial intelligence and conventional programming languages. Reviews Personal Consultant Plus, Smalltalk/V, and Nexpert Object, which are PC-based products inspired by problem-solving paradigms. Provides information on background and operation of each. (RT)

  17. Single-event upset in advanced PowerPC microprocessors

    NASA Technical Reports Server (NTRS)

    Irom, F.; Swift, G. M.; Farmanesh, F.; Millward, D. G.

    2002-01-01

    Proton and heavy-ion single-event upset susceptibility has been measured for the MotorolaPowerPC7400. The results show that this advanced device has low upset susceptibility, despite the scaling and design advances.

  18. Automatic image-driven segmentation of cardiac ventricles in cine anatomical MRI

    NASA Astrophysics Data System (ADS)

    Cocosco, Chris A.; Niessen, Wiro J.; Netsch, Thomas; Vonken, Evert-jan P. A.; Viergever, Max A.

    2005-08-01

    The automatic segmentation of the heart's two ventricles from dynamic ("cine") cardiac anatomical images, such as 3D+time short-axis MRI, is of significant clinical importance. Previously published automated methods have various disadvantages for routine clinical use. This work reports about a novel automatic segmentation method that is very fast, and robust against anatomical variability and image contrast variations. The method is mostly image-driven: it fully exploits the information provided by modern 4D (3D+time) balanced Fast Field Echo (bFFE) cardiac anatomical MRI, and makes only few and plausible assumptions about the images and the imaged heart. Specifically, the method does not need any geometrical shape models nor complex gray-level appearance models. The method simply uses the two ventricles' contraction-expansion cycle, as well as the ventricles' spatial coherence along the time dimension. The performance of the cardiac ventricles segmentation method was demonstrated through a qualitative visual validation on 32 clinical exams: no gross failures for the left-ventricle (right-ventricle) on 32 (30) of the exams were found. Also, a clinical validation of resulting quantitative cardiac functional parameters was performed against a manual quantification of 18 exams; the automatically computed Ejection Fraction (EF) correlated well to the manually computed one: linear regression with RMS=3.7% (RMS expressed in EF units).

  19. Computational hemodynamics of an implanted coronary stent based on three-dimensional cine angiography reconstruction.

    PubMed

    Chen, Mounter C Y; Lu, Po-Chien; Chen, James S Y; Hwang, Ned H C

    2005-01-01

    Coronary stents are supportive wire meshes that keep narrow coronary arteries patent, reducing the risk of restenosis. Despite the common use of coronary stents, approximately 20-35% of them fail due to restenosis. Flow phenomena adjacent to the stent may contribute to restenosis. Three-dimensional computational fluid dynamics (CFD) and reconstruction based on biplane cine angiography were used to assess coronary geometry and volumetric blood flows. A patient-specific left anterior descending (LAD) artery was reconstructed from single-plane x-ray imaging. With corresponding electrocardiographic signals, images from the same time phase were selected from the angiograms for dynamic three-dimensional reconstruction. The resultant three-dimensional LAD artery at end-diastole was adopted for detailed analysis. Both the geometries and flow fields, based on a computational model from CAE software (ANSYS and CATIA) and full three-dimensional Navier-Stroke equations in the CFD-ACE+ software, respectively, changed dramatically after stent placement. Flow fields showed a complex three-dimensional spiral motion due to arterial tortuosity. The corresponding wall shear stresses, pressure gradient, and flow field all varied significantly after stent placement. Combined angiography and CFD techniques allow more detailed investigation of flow patterns in various segments. The implanted stent(s) may be quantitatively studied from the proposed hemodynamic modeling approach.

  20. Cine EPID evaluation of two non-commercial techniques for DIBH

    SciTech Connect

    Jensen, Christopher; Urribarri, Jaime; Cail, Daniel; Rottmann, Joerg; Mishra, Pankaj; Lingos, Tatiana; Niedermayr, Thomas; Berbeco, Ross

    2014-02-15

    Purpose: To evaluate the efficacy of two noncommercial techniques for deep inspiration breathhold (DIBH) treatment of left-sided breast cancer (LSBC) usingcine electronic portal imaging device (EPID) images. Methods: 23 875 EPID images of 65 patients treated for LSBC at two different cancer treatment centers were retrieved. At the Milford Regional Cancer Center, DIBH stability was maintained by visual alignment of inroom lasers and patient skin tattoos (TAT). At the South Shore Hospital, a distance-measuring laser device (RTSSD) was implemented. For both centers,cine EPID images were acquired at least once per week during beam-on. Chest wall position relative to image boundary was measured and tracked over the course of treatment for every patient and treatment fraction for which data were acquired. Results: Median intrabeam chest motion was 0.31 mm for the TAT method and 0.37 mm for the RTSSD method. The maximum excursions exceeded our treatment protocol threshold of 3 mm in 0.3% of cases (TAT) and 1.2% of cases (RTSSD). The authors did not observe a clinically significant difference between the two datasets. Conclusions: Both noncommercial techniques for monitoring the DIBH location provided DIBH stability within the predetermined treatment protocol parameters (<3 mm). The intreatment imaging offered by the EPID operating incine mode facilitates retrospective analysis and validation of both techniques.

  1. Estimation of Myocardial Strain and Contraction Phase From Cine MRI Using Variational Data Assimilation.

    PubMed

    Tuyisenge, Viateur; Sarry, Laurent; Corpetti, Thomas; Innorta-Coupez, Elisabeth; Ouchchane, Lemlih; Cassagnes, Lucie

    2016-02-01

    This paper presents a new method to estimate left ventricle deformations using variational data assimilation that combines image observations from cine MRI and a dynamic evolution model of the heart. The main contribution of the model is that it embeds parameters modeling the contraction / relaxation process. It estimates myocardial motion and contraction parameters simultaneously, providing accurate complementary information for diagnosis. The method was applied to synthetic datasets with known ground truth motion and to 47 patients MRI datasets acquired at three slice locations (base, mid-ventricle and apex). Radial and circumferential strain components were compared to those obtained with a reference tag tracking software, exhibiting good agreement with intraclass correlation coefficients (ICC) above 0.8. Results were also evaluated against wall motion score indices used to assess cardiac kinetics in clinical practice. The assimilation process overcame issues caused by temporal artifacts as a result of the dynamic model, compared to using the observation term alone. Moreover we found that the new dynamic model, consisting of a piecewise transport model acting independently on systole and diastole performed better than the standard continuous transport model, which oversmooths temporal variations. Estimated strain and contraction parameters significantly correlated to clinical scores, making them promising features for diagnosing not only hypokinesia but also dyskinesia.

  2. A PC-Windows-Based program for geostatistical modeling application

    SciTech Connect

    Wu, G.G.; Yang, A.P.

    1994-12-31

    This paper describes a technically advanced, user-friendly, PC-Windows{sup TM} based reservoir simulation tool (SIMTOOLS) that allows construction of realistic reservoir models using a geostatistical approach. This PC-Windows based product has three application tools: Digitizing, mapping, and geostatistics. It has been designed primarily to enable reservoir engineers to apply the geostatistical gridding technique in mapping and reservoir simulation practices.

  3. Wf/pc Cycle 3 Calibration: Rapid Internal Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1992-06-01

    This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

  4. Wf/pc Cycle 2 Calibration: Rapid Internal Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1991-07-01

    This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

  5. Wf/pc Cycle 1 Calibration: Rapid Internal Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

  6. Accelerating Particles with Plasma

    ScienceCinema

    Litos, Michael; Hogan, Mark

    2016-07-12

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  7. Peak acceleration limiter

    NASA Technical Reports Server (NTRS)

    Chapman, C. P.

    1972-01-01

    Device is described that limits accelerations by shutting off shaker table power very rapidly in acceleration tests. Absolute value of accelerometer signal is used to trigger electronic switch which terminates test and sounds alarm.

  8. Linear Accelerator (LINAC)

    MedlinePlus

    ... equipment? How is safety ensured? What is this equipment used for? A linear accelerator (LINAC) is the ... Therapy (SBRT) . top of page How does the equipment work? The linear accelerator uses microwave technology (similar ...

  9. Accelerating Particles with Plasma

    SciTech Connect

    Litos, Michael; Hogan, Mark

    2014-11-05

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  10. Improved plasma accelerator

    NASA Technical Reports Server (NTRS)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  11. Accelerator Technology Division

    NASA Astrophysics Data System (ADS)

    1992-04-01

    In fiscal year (FY) 1991, the Accelerator Technology (AT) division continued fulfilling its mission to pursue accelerator science and technology and to develop new accelerator concepts for application to research, defense, energy, industry, and other areas of national interest. This report discusses the following programs: The Ground Test Accelerator Program; APLE Free-Electron Laser Program; Accelerator Transmutation of Waste; JAERI, OMEGA Project, and Intense Neutron Source for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Super Collider; The High-Power Microwave Program; (Phi) Factory Collaboration; Neutral Particle Beam Power System Highlights; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

  12. Unraveling the neuroprotective mechanisms of PrPC in excitotoxicity

    PubMed Central

    Llorens, Franc; del Río, José Antonio

    2012-01-01

    Knowledge of the natural roles of cellular prion protein (PrPC) is essential to an understanding of the molecular basis of prion pathologies. This GPI-anchored protein has been described in synaptic contacts, and loss of its synaptic function in complex systems may contribute to the synaptic loss and neuronal degeneration observed in prionopathy. In addition, Prnp knockout mice show enhanced susceptibility to several excitotoxic insults, GABAA receptor-mediated fast inhibition was weakened, LTP was modified and cellular stress increased. Although little is known about how PrPC exerts its function at the synapse or the downstream events leading to PrPC-mediated neuroprotection against excitotoxic insults, PrPC has recently been reported to interact with two glutamate receptor subunits (NR2D and GluR6/7). In both cases the presence of PrPC blocks the neurotoxicity induced by NMDA and Kainate respectively. Furthermore, signals for seizure and neuronal cell death in response to Kainate in Prnp knockout mouse are associated with JNK3 activity, through enhancing the interaction of GluR6 with PSD-95. In combination with previous data, these results shed light on the molecular mechanisms behind the role of PrPC in excitotoxicity. Future experimental approaches are suggested and discussed. PMID:22437735

  13. Photodynamic therapy with Pc 4 induces apoptosis of Candida albicans.

    PubMed

    Lam, Minh; Jou, Paul C; Lattif, Ali A; Lee, Yoojin; Malbasa, Christi L; Mukherjee, Pranab K; Oleinick, Nancy L; Ghannoum, Mahmoud A; Cooper, Kevin D; Baron, Elma D

    2011-01-01

    The high prevalence of drug resistance necessitates the development of novel antifungal agents against infections caused by opportunistic fungal pathogens, such as Candida albicans. Elucidation of apoptosis in yeast-like fungi may provide a basis for future therapies. In mammalian cells, photodynamic therapy (PDT) has been demonstrated to generate reactive oxygen species, leading to immediate oxidative modifications of biological molecules and resulting in apoptotic cell death. In this report, we assess the in vitro cytotoxicity and mechanism of PDT, using the photosensitizer Pc 4, in planktonic C. albicans. Confocal image analysis confirmed that Pc 4 localizes to cytosolic organelles, including mitochondria. A colony formation assay showed that 1.0 μM Pc 4 followed by light at 2.0 J cm(-2) reduced cell survival by 4 logs. XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide) assay revealed that Pc 4-PDT impaired fungal metabolic activity, which was confirmed using the FUN-1 (2-chloro-4-[2,3-dihydro-3-methyl-(benzo-1,3-thiazol-2-yl)-methylidene]-1-phenylquinolinium iodide) fluorescence probe. Furthermore, we observed changes in nuclear morphology characteristic of apoptosis, which were substantiated by increased externalization of phosphatidylserine and DNA fragmentation following Pc 4-PDT. These data indicate that Pc 4-PDT can induce apoptosis in C. albicans. Therefore, a better understanding of the process will be helpful, as PDT may become a useful treatment option for candidiasis.

  14. Accelerators, Colliders, and Snakes

    NASA Astrophysics Data System (ADS)

    Courant, Ernest D.

    2003-12-01

    The author traces his involvement in the evolution of particle accelerators over the past 50 years. He participated in building the first billion-volt accelerator, the Brookhaven Cosmotron, which led to the introduction of the "strong-focusing" method that has in turn led to the very large accelerators and colliders of the present day. The problems of acceleration of spin-polarized protons are also addressed, with discussions of depolarizing resonances and "Siberian snakes" as a technique for mitigating these resonances.

  15. Acceleration: It's Elementary

    ERIC Educational Resources Information Center

    Willis, Mariam

    2012-01-01

    Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between…

  16. Angular Acceleration without Torque?

    ERIC Educational Resources Information Center

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

  17. Accelerated test design

    NASA Technical Reports Server (NTRS)

    Mcdermott, P. P.

    1980-01-01

    The design of an accelerated life test program for electric batteries is discussed. A number of observations and suggestions on the procedures and objectives for conducting an accelerated life test program are presented. Equations based on nonlinear regression analysis for predicting the accelerated life test parameters are discussed.

  18. Impact of low signal intensity assessed by cine magnetic resonance imaging on detection of poorly viable myocardium in patients with prior myocardial infarction.

    PubMed

    Ota, Shingo; Tanimoto, Takashi; Orii, Makoto; Hirata, Kumiko; Shiono, Yasutsugu; Shimamura, Kunihiro; Matsuo, Yoshiki; Yamano, Takashi; Ino, Yasushi; Kitabata, Hironori; Yamaguchi, Tomoyuki; Kubo, Takashi; Tanaka, Atsushi; Imanishi, Toshio; Akasaka, Takashi

    2015-05-13

    Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been established as a modality to detect myocardial infarction (MI). However, the use of gadolinium contrast is limited in patients with advanced renal dysfunction. Although the signal intensity (SI) of infarct area assessed by cine MRI is low in some patients with prior MI, the prevalence and clinical significance of low SI has not been evaluated. The aim of this study was to evaluate how low SI assessed by cine MRI may relate to the myocardial viability in patients with prior MI. Fifty patients with prior MI underwent both cine MRI and LGE-MRI. The left ventricle was divided into 17 segments. The presence of low SI and the wall motion score (WMS) of each segment were assessed by cine MRI. The transmural extent of infarction was evaluated by LGE-MRI. LGE was detected in 329 of all 850 segments (39%). The low SI assessed by cine MRI was detected in 105 of 329 segments with LGE (32%). All segments with low SI had LGE. Of all 329 segments with LGE, the segments with low SI showed greater transmural extent of infarction (78 [72 - 84] % versus 53 [38 - 72] %, P < 0.01), thinner wall (4.0[3.1 - 4.8] mm versus 6.5 [5.2 - 8.1] mm, P < 0.01), and higher WMS (4.0 [4.0 - 4.0] versus 2.0 [2.0 - 3.0], P < 0.01). The low SI assessed by cine MRI may be effective for detecting poorly viable myocardium in patients with prior MI.

  19. Epitaxial growth and electronic properties of well ordered phthalocyanine heterojunctions MnPc/F{sub 16}CoPc

    SciTech Connect

    Lindner, Susi; Mahns, Benjamin; Treske, Uwe; Knupfer, Martin; Vilkov, Oleg; Haidu, Francisc; Fronk, Michael; Zahn, Dietrich R. T.

    2014-09-07

    We have prepared phthalocyanine heterojunctions out of MnPc and F{sub 16}CoPc, which were studied by means of X-ray absorption spectroscopy. This heterojunction is characterized by a charge transfer at the interface, resulting in charged MnPc{sup δ} {sup +} and F{sub 16}CoPc{sup δ} {sup −} species. Our data reveal that the molecules are well ordered and oriented parallel to the substrate surface. Furthermore, we demonstrate the filling of the Co 3d{sub z{sup 2}} orbital due to the charge transfer, which supports the explanation of the density functional theory, that the charge transfer is local and affects the metal centers only.

  20. Combination Therapy Accelerates Diabetic Wound Closure

    PubMed Central

    Allen Jr., Robert J.; Soares, Marc A.; Haberman, Ilyse D.; Szpalski, Caroline; Schachar, Jeffrey; Lin, Clarence D.; Nguyen, Phuong D.; Saadeh, Pierre B.; Warren, Stephen M.

    2014-01-01

    Background Non-healing foot ulcers are the most common cause of non-traumatic amputation and hospitalization amongst diabetics in the developed world. Impaired wound neovascularization perpetuates a cycle of dysfunctional tissue repair and regeneration. Evidence implicates defective mobilization of marrow-derived progenitor cells (PCs) as a fundamental cause of impaired diabetic neovascularization. Currently, there are no FDA-approved therapies to address this defect. Here we report an endogenous PC strategy to improve diabetic wound neovascularization and closure through a combination therapy of AMD3100, which mobilizes marrow-derived PCs by competitively binding to the cell surface CXCR4 receptor, and PDGF-BB, which is a protein known to enhance cell growth, progenitor cell migration and angiogenesis. Methods and Results Wounded mice were assigned to 1 of 5 experimental arms (n = 8/arm): saline treated wild-type, saline treated diabetic, AMD3100 treated diabetic, PDGF-BB treated diabetic, and AMD3100/PDGF-BB treated diabetic. Circulating PC number and wound vascularity were analyzed for each group (n = 8/group). Cellular function was assessed in the presence of AMD3100. Using a validated preclinical model of type II diabetic wound healing, we show that AMD3100 therapy (10 mg/kg; i.p. daily) alone can rescue diabetes-specific defects in PC mobilization, but cannot restore normal wound neovascularization. Through further investigation, we demonstrate an acquired trafficking-defect within AMD3100-treated diabetic PCs that can be rescued by PDGF-BB (2 μg; topical) supplementation within the wound environment. Finally, we determine that combination therapy restores diabetic wound neovascularization and accelerates time to wound closure by 40%. Conclusions Combination AMD3100 and PDGF-BB therapy synergistically improves BM PC mobilization and trafficking, resulting in significantly improved diabetic wound closure and neovascularization. The success of this

  1. PC Tutor. Bericht uber ein PC-gestutzes Tutorensystem = PC Tutor. Report on a Tutoring System with Personal Computer. ZIFF Papiere 75.

    ERIC Educational Resources Information Center

    Fritsch, Helmut

    A project was conducted to increase as well as to professionalize communication between tutors and learners in a West German university's distance education program by the use of personal computers. Two tutors worked on the systematic development of a PC-based correcting system. The goal, apart from developing general language skills in English,…

  2. Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber

    SciTech Connect

    England, R.J.; Colby, E.R.; Ischebeck, R.; McGuinness, C.M.; Noble, R.; Plettner, T.; Sears, C.M.S.; Siemann, R.H.; Spencer, J.E.; Walz, D.; /SLAC

    2011-11-21

    An experimental effort is currently underway at the E-163 test beamline at Stanford Linear Accelerator Center to use a hollow-core photonic bandgap (PBG) fiber as a high-gradient laser-based accelerating structure for electron bunches. For the initial stage of this experiment, a 50pC, 60 MeV electron beam will be coupled into the fiber core and the excited modes will be detected using a spectrograph to resolve their frequency signatures in the wakefield radiation generated by the beam. They will describe the experimental plan and recent simulation studies of candidate fibers.

  3. Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber

    SciTech Connect

    England, R. J.; Colby, E. R.; McGuinness, C. M.; Noble, R.; Plettner, T.; Siemann, R. H.; Spencer, J. E.; Walz, D.; Ischebeck, R.; Sears, C. M. S.

    2009-01-22

    An experimental effort is currently underway at the E-163 test beamline at Stanford Linear Accelerator Center to use a hollow-core photonic bandgap (PBG) fiber as a high-gradient laser-based accelerating structure for electron bunches. For the initial stage of this experiment, a 50 pC, 60 MeV electron beam will be coupled into the fiber core and the excited modes will be detected using a spectrograph to resolve their frequency signatures in the wakefield radiation generated by the beam. We will describe the experimental plan and recent simulation studies of candidate fibers.

  4. Evaluation of ventricular dysfunction using semi-automatic longitudinal strain analysis of four-chamber cine MR imaging.

    PubMed

    Kawakubo, Masateru; Nagao, Michinobu; Kumazawa, Seiji; Yamasaki, Yuzo; Chishaki, Akiko S; Nakamura, Yasuhiko; Honda, Hiroshi; Morishita, Junji

    2016-02-01

    The aim of this study was to evaluate ventricular dysfunction using the longitudinal strain analysis in 4-chamber (4CH) cine MR imaging, and to investigate the agreement between the semi-automatic and manual measurements in the analysis. Fifty-two consecutive patients with ischemic, or non-ischemic cardiomyopathy and repaired tetralogy of Fallot who underwent cardiac MR examination incorporating cine MR imaging were retrospectively enrolled. The LV and RV longitudinal strain values were obtained by semi-automatically and manually. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff of the minimum longitudinal strain value for the detection of patients with cardiac dysfunction. The correlations between manual and semi-automatic measurements for LV and RV walls were analyzed by Pearson coefficient analysis. ROC analysis demonstrated the optimal cut-off of the minimum longitudinal strain values (εL_min) for diagnoses the LV and RV dysfunction at a high accuracy (LV εL_min = -7.8 %: area under the curve, 0.89; sensitivity, 83 %; specificity, 91 %, RV εL_min = -15.7 %: area under the curve, 0.82; sensitivity, 92 %; specificity, 68 %). Excellent correlations between manual and semi-automatic measurements for LV and RV free wall were observed (LV, r = 0.97, p < 0.01; RV, r = 0.79, p < 0.01). Our semi-automatic longitudinal strain analysis in 4CH cine MR imaging can evaluate LV and RV dysfunction with simply and easy measurements. The strain analysis could have extensive application in cardiac imaging for various clinical cases.

  5. Monitoring tumor motion with on-line mega-voltage cone-beam computed tomography imaging in a cine mode

    NASA Astrophysics Data System (ADS)

    Reitz, Bodo; Gayou, Olivier; Parda, David S.; Miften, Moyed

    2008-02-01

    Accurate daily patient localization is becoming increasingly important in external-beam radiotherapy (RT). Mega-voltage cone-beam computed tomography (MV-CBCT) utilizing a therapy beam and an on-board electronic portal imager can be used to localize tumor volumes and verify the patient's position prior to treatment. MV-CBCT produces a static volumetric image and therefore can only account for inter-fractional changes. In this work, the feasibility of using the MV-CBCT raw data as a fluoroscopic series of portal images to monitor tumor changes due to e.g. respiratory motion was investigated. A method was developed to read and convert the CB raw data into a cine. To improve the contrast-to-noise ratio on the MV-CB projection data, image post-processing with filtering techniques was investigated. Volumes of interest from the planning CT were projected onto the MV-cine. Because of the small exposure and the varying thickness of the patient depending on the projection angle, soft-tissue contrast was limited. Tumor visibility as a function of tumor size and projection angle was studied. The method was well suited in the upper chest, where motion of the tumor as well as of the diaphragm could be clearly seen. In the cases of patients with non-small cell lung cancer with medium or large tumor masses, we verified that the tumor mass was always located within the PTV despite respiratory motion. However for small tumors the method is less applicable, because the visibility of those targets becomes marginal. Evaluation of motion in non-superior-inferior directions might also be limited for small tumor masses. Viewing MV-CBCT data in a cine mode adds to the utility of MV-CBCT for verification of tumor motion and for deriving individualized treatment margins.

  6. Fiber Accelerating Structures

    SciTech Connect

    Hammond, Andrew P.; /Reed Coll. /SLAC

    2010-08-25

    One of the options for future particle accelerators are photonic band gap (PBG) fiber accelerators. PBG fibers are specially designed optical fibers that use lasers to excite an electric field that is used to accelerate electrons. To improve PBG accelerators, the basic parameters of the fiber were tested to maximize defect size and acceleration. Using the program CUDOS, several accelerating modes were found that maximized these parameters for several wavelengths. The design of multiple defects, similar to having closely bound fibers, was studied to find possible coupling or the change of modes. The amount of coupling was found to be dependent on distance separated. For certain distances accelerating coupled modes were found and examined. In addition, several non-periodic fiber structures were examined using CUDOS. The non-periodic fibers produced several interesting results and promised more modes given time to study them in more detail.

  7. High brightness electron accelerator

    DOEpatents

    Sheffield, Richard L.; Carlsten, Bruce E.; Young, Lloyd M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  8. Gait analysis using gravitational acceleration measured by wearable sensors.

    PubMed

    Takeda, Ryo; Tadano, Shigeru; Todoh, Masahiro; Morikawa, Manabu; Nakayasu, Minoru; Yoshinari, Satoshi

    2009-02-09

    A novel method for measuring human gait posture using wearable sensor units is proposed. The sensor units consist of a tri-axial acceleration sensor and three gyro sensors aligned on three axes. The acceleration and angular velocity during walking were measured with seven sensor units worn on the abdomen and the lower limb segments (both thighs, shanks and feet). The three-dimensional positions of each joint are calculated from each segment length and joint angle. Joint angle can be estimated mechanically from the gravitational acceleration along the anterior axis of the segment. However, the acceleration data during walking includes three major components; translational acceleration, gravitational acceleration and external noise. Therefore, an optimization analysis was represented to separate only the gravitational acceleration from the acceleration data. Because the cyclic patterns of acceleration data can be found during constant walking, a FFT analysis was applied to obtain some characteristic frequencies in it. A pattern of gravitational acceleration was assumed using some parts of these characteristic frequencies. Every joint position was calculated from the pattern under the condition of physiological motion range of each joint. An optimized pattern of the gravitational acceleration was selected as a solution of an inverse problem. Gaits of three healthy volunteers were measured by walking for 20s on a flat floor. As a result, the acceleration data of every segment was measured simultaneously. The characteristic three-dimensional walking could be shown by the expression using a stick figure model. In addition, the trajectories of the knee joint in the horizontal plane could be checked by visual imaging on a PC. Therefore, this method provides important quantitive information for gait diagnosis.

  9. TU-F-CAMPUS-J-03: Evaluation of a New GE Device-Less Cine 4D-CT

    SciTech Connect

    Martin, R; Pan, T; Chandler, A; Doan, D; Rowland, C

    2015-06-15

    Purpose: Standard cine 4D-CT (S-4DCT) is the cine CT scan of the thorax followed by image sorting with the respiratory signal recorded by the RPM. Although the feasibility of cine 4D-CT without RPM or device-less 4DCT (DL-4DCT) has been reported in a laboratory setting, the only commercial implementation of DL-4DCT was made recently by GE based on the measurements of the lung, body and air area and density. We report the initial results of this new DL-4DCT on its determination of gross tumor volume (GTV). Methods: 30 stereotactic body radiation therapy (SBRT) patients with NSCLC were included in the study. All patients received the S-4DCT for their treatment planning. Their cine CT data without the respiratory signal from RPM were submitted to the DL-4DCT. The DL-4DCT image quality was assessed in reference to S-4DCT. Using maximum intensity projection (MIP) images, the GTVs of the S-4DCT and DL-4DCT were compared on a subset of 9 patients whose tumors in the low density lung regions could be contoured using a region growing algorithm in MIM without contouring bias from the user. A lower threshold of −424 HU was used for all patients and other algorithm parameters were held constant for each patient. Results: The DL-4DCT was able to produce the 4DCT images on 29 out of the 30 SBRT cases. One case failed due to the enhanced calcification surrounding both the breast implants. The GTVs determined on the 9 patients with DL-4DCT were 4.2 ± 4.8% smaller than the GTVs with S-4DCT. However, this was statistically insignificant (p=0.15). The Dice similarity coefficients were 95.1 ± 1.8%. The image quality of DL-4DCT and S-4DCT was similar on the 29 cases. Conclusion: The first commercial DL-4DCT was promising in generating 4D-CT images without a respiratory monitoring device in this preliminary study of 30 patients.

  10. [Digital thermo-coronary angiography--development and validation of the method in comparison with conventional cine-coronary angiography].

    PubMed

    Mohr, F W; Grundfest, W; Litvack, F; Forrester, J; Matloff, J; Kirchhoff, P G

    1989-07-01

    We describe the technique-thermal coronary angiography (TCA)-for real-time assessment of coronary anatomy and flow. The goal of this study was to compare thermal coronary angiography to cine coronary angiography and to validate its value for detecting stenoses. We studied the exposed LAD both in beating and arrested hearts in 11 open-chest pigs by TCA and cine angiography. We used an AGA 782 Thermovision system combined with a TIC 8000 digital image processor providing coronary images with 0.1-0.2 mm spatial and 0.1 degrees C thermal resolution, and a CFR x-ray system. The coronary arteries were catheterized via the right carotid artery, using standard 5F catheters. The thermal camera was focused at a 1m-distance to the heart surface and the x-ray was angled to LAO position. We performed simultaneous thermal and cine angiography using Angiovist 370 at different temperatures (10-40 degrees C) and injection rates (1-2.5 ml/s). Different grades of stenoses were created by snares. Thermistor probe readings of the epimyocardium and the left atrial blood were performed to reference the thermal camera measurements. We obtained high resolution TCA images of both the coronaries and of the myocardial perfusion beds whenever there was greater than 4 degrees C difference between injectate and epicardial temperature. The TCA detection of stenoses as compared to cine angiography was 29/30 (96.6%) in arrested and 36/42 (85.7%) in beating hearts. Coronary occlusion produced immediate and dramatic perfusion defects as detected by TCA. TCAs were highly reproducible. Injection rate of 2 ml/s provided optimal thermal coronary images. Thermal angiograms of the LAD were sometimes affected by large crossing coronary veins, myocardial bridges, and excess of fat pretending nonexistent coronary stenosis. TCA is a highly sensitive and reproducible method as compared to standard coronary angiography and allows for detection of coronary stenoses. The image quality was best in arrested hearts.

  11. Acceleration in astrophysics

    SciTech Connect

    Colgate, S.A.

    1993-12-31

    The origin of cosmic rays and applicable laboratory experiments are discussed. Some of the problems of shock acceleration for the production of cosmic rays are discussed in the context of astrophysical conditions. These are: The presumed unique explanation of the power law spectrum is shown instead to be a universal property of all lossy accelerators; the extraordinary isotropy of cosmic rays and the limited diffusion distances implied by supernova induced shock acceleration requires a more frequent and space-filling source than supernovae; the near perfect adiabaticity of strong hydromagnetic turbulence necessary for reflecting the accelerated particles each doubling in energy roughly 10{sup 5} to {sup 6} scatterings with negligible energy loss seems most unlikely; the evidence for acceleration due to quasi-parallel heliosphere shocks is weak. There is small evidence for the expected strong hydromagnetic turbulence, and instead, only a small number of particles accelerate after only a few shock traversals; the acceleration of electrons in the same collisionless shock that accelerates ions is difficult to reconcile with the theoretical picture of strong hydromagnetic turbulence that reflects the ions. The hydromagnetic turbulence will appear adiabatic to the electrons at their much higher Larmor frequency and so the electrons should not be scattered incoherently as they must be for acceleration. Therefore the electrons must be accelerated by a different mechanism. This is unsatisfactory, because wherever electrons are accelerated these sites, observed in radio emission, may accelerate ions more favorably. The acceleration is coherent provided the reconnection is coherent, in which case the total flux, as for example of collimated radio sources, predicts single charge accelerated energies much greater than observed.

  12. Real-time visualization of large volume datasets on standard PC hardware.

    PubMed

    Xie, Kai; Yang, Jie; Zhu, Y M

    2008-05-01

    In medical area, interactive three-dimensional volume visualization of large volume datasets is a challenging task. One of the major challenges in graphics processing unit (GPU)-based volume rendering algorithms is the limited size of texture memory imposed by current GPU architecture. We attempt to overcome this limitation by rendering only visible parts of large CT datasets. In this paper, we present an efficient, high-quality volume rendering algorithm using GPUs for rendering large CT datasets at interactive frame rates on standard PC hardware. We subdivide the volume dataset into uniform sized blocks and take advantage of combinations of early ray termination, empty-space skipping and visibility culling to accelerate the whole rendering process and render visible parts of volume data. We have implemented our volume rendering algorithm for a large volume data of 512 x 304 x 1878 dimensions (visible female), and achieved real-time performance (i.e., 3-4 frames per second) on a Pentium 4 2.4GHz PC equipped with NVIDIA Geforce 6600 graphics card ( 256 MB video memory). This method can be used as a 3D visualization tool of large CT datasets for doctors or radiologists.

  13. Cerebrosides from Sea Cucumber Protect Against Oxidative Stress in SAMP8 Mice and PC12 Cells.

    PubMed

    Che, Hongxia; Du, Lei; Cong, Peixu; Tao, Suyuan; Ding, Ning; Wu, Fengjuan; Xue, Changhu; Xu, Jie; Wang, Yuming

    2017-04-01

    Alzheimer's disease (AD) is a neurodegenerative disorder. Emerging evidence implicates β-amyloid (Aβ) plays a critical role in the progression of AD. In this study, we investigated the protective effect of cerebrosides obtained from sea cucumber against senescence-accelerated mouse prone 8 (SAMP8) mice in vivo. We also studied the effect of cerebrosides on Aβ-induced cytotoxicity on the rat pheochromocytoma cell (PC12) and the underlying molecular mechanisms. Cerebrosides ameliorated learning and memory deficits and the Aβ accumulation in demented mice, decreased the content of malondialdehyde (MDA), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-OHdG), 8-hydroxy-2'-deoxyguanosine (8-oxo-G), and nitric oxide (NO), and enhanced the superoxide dismutase (SOD) activity significantly. The neuroprotective effect of sea cucumber cerebrosides (SCC) was also verified in vitro: the cerebrosides increased the survival rate of PC12 cells, recovered the cellular morphology, downregulated the protein levels of Caspase-9, cleaved Caspase-3, total Caspase-3, and Bax, and upregulated the protein level of Bcl-2, revealing that cerebrosides could inhibit Aβ-induced cell apoptosis. The results showed the protective effect of SCC was regulated by the mitochondria-dependent apoptotic pathway. Our results provide a new approach to developing the marine organisms as functional foods for neuroprotection.

  14. Using a PC and external media to quantitatively investigate electromagnetic induction

    NASA Astrophysics Data System (ADS)

    Bonanno, A.; Bozzo, G.; Camarca, M.; Sapia, P.

    2011-07-01

    In this article we describe an experimental learning path about electromagnetic induction which uses an Atwood machine where one of the two hanging bodies is a cylindrical magnet falling through a plexiglass guide, surrounded either by a coil or by a copper pipe. The first configuration (magnet falling across a coil) allows students to quantitatively study the Faraday-Neumann-Lenz law, while the second configuration (falling through a copper pipe) permits learners to investigate the complex phenomena of induction by quantifying the amount of electric power dissipated through the pipe as a result of Foucault eddy currents, when the magnet travels through the pipe. The magnet's fall acceleration can be set by adjusting the counterweight of the Atwood machine so that both the kinematic quantities associated with it and the electromotive force induced within the coil are continuously and quantitatively monitored (respectively, by a common personal computer (PC) equipped with a webcam and by freely available software that makes it possible to use the audio card to convert the PC into an oscilloscope). Measurements carried out when the various experimental parameters are changed provide a useful framework for a thorough understanding and clarification of the conceptual nodes related to electromagnetic induction. The proposed learning path is under evaluation in various high schools participating in the project 'Lauree Scientifiche' promoted by the Italian Department of Education.

  15. Ternary phase diagram of dipalmitoyl-PC/dilauroyl-PC/cholesterol: nanoscopic domain formation driven by cholesterol.

    PubMed Central

    Feigenson, G W; Buboltz, J T

    2001-01-01

    A ternary phase diagram is proposed for the hydrated lamellar lipid mixture dipalmitoylphosphatidylcholine/dilauroylphosphatidylcholine/cholesterol (DPPC/DLPC/cholesterol) at room temperature. The entire composition space has been thoroughly mapped by complementary experimental techniques, revealing interesting phase behavior that has not been previously described. Confocal fluorescence microscopy shows a regime of coexisting DPPC-rich ordered and DLPC-rich fluid lamellar phases, having an upper boundary at apparently constant cholesterol mole fraction chi(chol) approximately 0.16. Fluorescence resonance energy transfer experiments confirm the identification and extent of this two-phase regime and, furthermore, reveal a 1-phase regime between chi(chol) approximately 0.16 and 0.25, consisting of ordered and fluid nanoscopic domains. Dipyrene-PC excimer/monomer measurements confirm the new regime between chi(chol) approximately 0.16 and 0.25 and also show that rigidly ordered phases seem to disappear around chi(chol) approximately 0.25. This study should be considered as a step toward a more complete understanding of lateral heterogeneity within biomembranes. Cholesterol may play a role in domain separation on the nanometer scale. PMID:11371452

  16. Cine-servo lens technology for 4K broadcast and cinematography

    NASA Astrophysics Data System (ADS)

    Nurishi, Ryuji; Wakazono, Tsuyoshi; Usui, Fumiaki

    2015-09-01

    Central to the rapid evolution of 4K image capture technology in the past few years, deployment of large-format cameras with Super35mm Single Sensors is increasing in TV production for diverse shows such as dramas, documentaries, wildlife, and sports. While large format image capture has been the standard in the cinema world for quite some time, the recent experiences within the broadcast industry have revealed a variety of requirement differences for large format lenses compared to those of the cinema industry. A typical requirement for a broadcast lens is a considerably higher zoom ratio in order to avoid changing lenses in the middle of a live event, which is mostly not the case for traditional cinema productions. Another example is the need for compact size, light weight, and servo operability for a single camera operator shooting in a shoulder-mount ENG style. On the other hand, there are new requirements that are common to both worlds, such as smooth and seamless change in angle of view throughout the long zoom range, which potentially offers new image expression that never existed in the past. This paper will discuss the requirements from the two industries of cinema and broadcast, while at the same time introducing the new technologies and new optical design concepts applied to our latest "CINE-SERVO" lens series which presently consists of two models, CN7x17KAS-S and CN20x50IAS-H. It will further explain how Canon has realized 4K optical performance and fast servo control while simultaneously achieving compact size, light weight and high zoom ratio, by referring to patent-pending technologies such as the optical power layout, lens construction, and glass material combinations.

  17. Quantification of lung tumor rotation with automated landmark extraction using orthogonal cine MRI images

    NASA Astrophysics Data System (ADS)

    Paganelli, Chiara; Lee, Danny; Greer, Peter B.; Baroni, Guido; Riboldi, Marco; Keall, Paul

    2015-09-01

    The quantification of tumor motion in sites affected by respiratory motion is of primary importance to improve treatment accuracy. To account for motion, different studies analyzed the translational component only, without focusing on the rotational component, which was quantified in a few studies on the prostate with implanted markers. The aim of our study was to propose a tool able to quantify lung tumor rotation without the use of internal markers, thus providing accurate motion detection close to critical structures such as the heart or liver. Specifically, we propose the use of an automatic feature extraction method in combination with the acquisition of fast orthogonal cine MRI images of nine lung patients. As a preliminary test, we evaluated the performance of the feature extraction method by applying it on regions of interest around (i) the diaphragm and (ii) the tumor and comparing the estimated motion with that obtained by (i) the extraction of the diaphragm profile and (ii) the segmentation of the tumor, respectively. The results confirmed the capability of the proposed method in quantifying tumor motion. Then, a point-based rigid registration was applied to the extracted tumor features between all frames to account for rotation. The median lung rotation values were  -0.6   ±   2.3° and  -1.5   ±   2.7° in the sagittal and coronal planes respectively, confirming the need to account for tumor rotation along with translation to improve radiotherapy treatment.

  18. Error analysis of cine phase contrast MRI velocity measurements used for strain calculation.

    PubMed

    Jensen, Elisabeth R; Morrow, Duane A; Felmlee, Joel P; Odegard, Gregory M; Kaufman, Kenton R

    2015-01-02

    Cine Phase Contrast (CPC) MRI offers unique insight into localized skeletal muscle behavior by providing the ability to quantify muscle strain distribution during cyclic motion. Muscle strain is obtained by temporally integrating and spatially differentiating CPC-encoded velocity. The aim of this study was to quantify CPC measurement accuracy and precision and to describe error propagation into displacement and strain. Using an MRI-compatible jig to move a B-gel phantom within a 1.5 T MRI bore, CPC-encoded velocities were collected. The three orthogonal encoding gradients (through plane, frequency, and phase) were evaluated independently in post-processing. Two systematic error types were corrected: eddy current-induced bias and calibration-type error. Measurement accuracy and precision were quantified before and after removal of systematic error. Through plane- and frequency-encoded data accuracy were within 0.4 mm/s after removal of systematic error - a 70% improvement over the raw data. Corrected phase-encoded data accuracy was within 1.3 mm/s. Measured random error was between 1 to 1.4 mm/s, which followed the theoretical prediction. Propagation of random measurement error into displacement and strain was found to depend on the number of tracked time segments, time segment duration, mesh size, and dimensional order. To verify this, theoretical predictions were compared to experimentally calculated displacement and strain error. For the parameters tested, experimental and theoretical results aligned well. Random strain error approximately halved with a two-fold mesh size increase, as predicted. Displacement and strain accuracy were within 2.6 mm and 3.3%, respectively. These results can be used to predict the accuracy and precision of displacement and strain in user-specific applications.

  19. An introduction to acceleration mechanisms

    SciTech Connect

    Palmer, R.B.

    1987-05-01

    This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free Electron Laser Acceleration, Inverse Cerenkov Acceleration, Gravity Acceleration, 2D Linac Acceleration and Conventional Iris Loaded Linac Structure Acceleration. (LSP)

  20. Schooling in Times of Acceleration

    ERIC Educational Resources Information Center

    Buddeberg, Magdalena; Hornberg, Sabine

    2017-01-01

    Modern societies are characterised by forms of acceleration, which influence social processes. Sociologist Hartmut Rosa has systematised temporal structures by focusing on three categories of social acceleration: technical acceleration, acceleration of social change, and acceleration of the pace of life. All three processes of acceleration are…

  1. Demonstration of a PC 25 Fuel Cell in Russia

    SciTech Connect

    John C. Trocciola; Thomas N. Pompa; Linda S. Boyd

    2004-09-01

    This project involved the installation of a 200kW PC25C{trademark} phosphoric-acid fuel cell power plant at Orgenergogaz, a Gazprom industrial site in Russia. In April 1997, a PC25C{trademark} was sold by ONSI Corporation to Orgenergogaz, a subsidiary of the Russian company ''Gazprom''. Due to instabilities in the Russian financial markets, at that time, the unit was never installed and started by Orgenergogaz. In October of 2001 International Fuel Cells (IFC), now known as UTC Fuel Cells (UTCFC), received a financial assistance award from the United States Department of Energy (DOE) entitled ''Demonstration of PC 25 Fuel Cell in Russia''. Three major tasks were part of this award: the inspection of the proposed site and system, start-up assistance, and installation and operation of the powerplant.

  2. Aspartame-induced apoptosis in PC12 cells.

    PubMed

    Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

    2014-01-01

    Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity.

  3. Expression of dystrophin Dp71 during PC12 cell differentiation.

    PubMed

    Cisneros, B; Rendon, A; Genty, V; Aranda, G; Marquez, F; Mornet, D; Montañez, C

    1996-08-02

    The expression of dystrophin-protein 71 (Dp71) was investigated during nerve growth factor (NGF) induced differentiation of PC12 cells. A semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay was designed to measure Dp71 mRNA, whereas the Dp71 protein amount was evaluated by immunoblot analysis using an anti-dystrophin monoclonal antibody. Comparison with control cultures showed that Dp71 mRNA and protein levels increased in parallel with NGF treatment peaking with increments of 60% and 1.4 times, respectively. The upregulation of Dp71 expression during PC12 cells differentiation point at PC12 cells as a suitable model for studying the function of Dp71 in neuronal cells.

  4. Modelling of Pc5 pulsation structure in the magnetosphere

    NASA Astrophysics Data System (ADS)

    Walker, A. D. M.

    1980-03-01

    Magnetohydrodynamic resonance theory is used to model the structure of the magnetospheric and ionospheric electric and magnetic fields associated with Pc5 geomagnetic pulsations. In this paper the variation of the fields across the invariant latitude of the resonance are computed. The results are combined with calculations of the variation along a field line to map the fields down to the ionosphere. In one case the results are compared with measurements obtained by the STARE auroral radar and show good agreement. The relationship between the width of the resonance region and ionospheric height-integrated Pedersen conductivity is computed and it is shown how auroral radar measurements of Pc5 oscillations could be used to determine ionospheric height-integrated Pedersen conductivity. It is pointed out that from these calculations it would be possible to identify the field line on which a satellite was located by comparing a Pc5 pulsation observed by the satellite, and the same pulsation observed by STARE.

  5. PC-1D installation manual and user's guide

    SciTech Connect

    Basore, P.A.

    1991-05-01

    PC-1D is a software package for personal computers that uses finite-element analysis to solve the fully-coupled two-carrier semiconductor transport equations in one dimension. This program is particularly useful for analyzing the performance of optoelectronic devices such as solar cells, but can be applied to any bipolar device whose carrier flows are primarily one-dimensional. This User's Guide provides the information necessary to install PC-1D, define a problem for solution, solve the problem, and examine the results. Example problems are presented which illustrate these steps. The physical models and numerical methods utilized are presented in detail. This document supports version 3.1 of PC-1D, which incorporates faster numerical algorithms with better convergence properties than previous versions of the program. 51 refs., 17 figs., 5 tabs.

  6. Tablet PC as a mobil PACS terminal using wireless LAN

    NASA Astrophysics Data System (ADS)

    Tsao, Bo-Shen; Ching, Yu-Tai; Lee, Wen-Jeng; Chen, Shyh-Jye; Chang, Chia-Hung; Chen, Chien-Jung; Yen, York; Lee, Yuan-Ten

    2003-05-01

    A PACS mobile terminal has applications in ward round, emergency room and remote teleradiology consultation. Personal Digital Assistants (PDAs) have the highest mobility and are used for many medical applications. However, their roles are limited in the field of radiology due to small screen size. In this study, we built a wireless PACS terminal using a hand-held tablet-PC. A tablet PC (X-pilot, LEO systems, Taiwan) running the WinCE operating systems was used as our mobile PACS terminal. This device is equipped with 800×600 resolution 10.4 inch TFT monitor. The network connection between the tablet PC and the server was linked via wireless LAN (IEEE 802.11b).

  7. Uniformly accelerated black holes

    NASA Astrophysics Data System (ADS)

    Letelier, Patricio S.; Oliveira, Samuel R.

    2001-09-01

    The static and stationary C metric are examined in a generic framework and their interpretations studied in some detail, especially those with two event horizons, one for the black hole and another for the acceleration. We find that (i) the spacetime of an accelerated static black hole is plagued by either conical singularities or a lack of smoothness and compactness of the black hole horizon, (ii) by using standard black hole thermodynamics we show that accelerated black holes have a higher Hawking temperature than Unruh temperature of the accelerated frame, and (iii) the usual upper bound on the product of the mass and acceleration parameters (<1/27) is just a coordinate artifact. The main results are extended to accelerated rotating black holes with no significant changes.

  8. The Dielectric Wall Accelerator

    SciTech Connect

    Caporaso, George J.; Chen, Yu-Jiuan; Sampayan, Stephen E.

    2009-01-01

    The Dielectric Wall Accelerator (DWA), a class of induction accelerators, employs a novel insulating beam tube to impress a longitudinal electric field on a bunch of charged particles. The surface flashover characteristics of this tube may permit the attainment of accelerating gradients on the order of 100 MV/m for accelerating pulses on the order of a nanosecond in duration. A virtual traveling wave of excitation along the tube is produced at any desired speed by controlling the timing of pulse generating modules that supply a tangential electric field to the tube wall. Because of the ability to control the speed of this virtual wave, the accelerator is capable of handling any charge to mass ratio particle; hence it can be used for electrons, protons and any ion. The accelerator architectures, key technologies and development challenges will be described.

  9. Realizing broad-bandwidth visible wavelength photodiode based on solution-processed ZnPc/PC71BM dyad

    NASA Astrophysics Data System (ADS)

    Zafar, Qayyum; Fatima, Noshin; Karimov, Khasan S.; Ahmed, Muhammad M.; Sulaiman, Khaulah

    2017-02-01

    Herein, we demonstrate a solution-processed visible wavelength organic photodiode (OPD) using donor/acceptor dyad of zinc phthalocyanine (ZnPc) and [6,6]-phenyl-C71-butyric-acid methyl ester (PC71BM), respectively. The synergic absorption profiles of both ZnPc and PC71BM moieties have been exploited to realize broader (350 and 800 nm) and consistent absorption spectrum of the photoactive film. The optimum loading ratio (by volume) of D/A dyad has been estimated to be 1:0.8, via quenching phenomenon in ZnPc photoluminescence spectrum. The performance of the OPD has been evaluated by detecting the photocurrent density with respect to varied illumination levels (0-150 mW/cm2) of impinging light at different reverse bias conditions. Under identical reverse bias mode, the photocurrent density has shown significant upsurge as the incident intensity of light is increased; ultimately leading to the significantly higher responsivity (162.4 μA/W) of the fabricated diode. The light to dark current density ratio (Jph/Jd) of the device at 3 V reverse bias has been calculated to be ∼20.12. The transient photocurrent density response of the fabricated OPD has also been characterized at -4 V operational bias under switch ON/OFF illumination. The measured response and recovery time for the fabricated OPD are ∼200 and 300 ms, respectively.

  10. Optically pulsed electron accelerator

    DOEpatents

    Fraser, J.S.; Sheffield, R.L.

    1985-05-20

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  11. Optically pulsed electron accelerator

    DOEpatents

    Fraser, John S.; Sheffield, Richard L.

    1987-01-01

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  12. ACCELERATION RESPONSIVE SWITCH

    DOEpatents

    Chabrek, A.F.; Maxwell, R.L.

    1963-07-01

    An acceleration-responsive device with dual channel capabilities whereby a first circuit is actuated upon attainment of a predetermined maximum acceleration level and when the acceleration drops to a predetermined minimum acceleriltion level another circuit is actuated is described. A fluid-damped sensing mass slidably mounted in a relatively frictionless manner on a shaft through the intermediation of a ball bushing and biased by an adjustable compression spring provides inertially operated means for actuating the circuits. (AEC)

  13. The foxhole accelerating structure

    SciTech Connect

    Fernow, R.C.; Claus, J.

    1992-07-17

    This report examines some properties of a new type of open accelerating structure. It consists of a series of rectangular cavities, which we call foxholes, joined by a beam channel. The power for accelerating the particles comes from an external radiation source and enters the cavities through their open upper surfaces. Analytic and computer calculations are presented showing that the foxhole is a suitable structure for accelerating relativistic electrons.

  14. Run-08 pC polarization analysis - October 16, 2008

    SciTech Connect

    Dharmawardane,V.; Bazilevsky,A.; Bunce, G.; Gill, R.; Huang, H.; Makdisi, Y.; Nakagawa, I.; Morozov, B.; Okada, H.; Sivertz, M.; Zelenski, A.; Alekseev, I.; Svirida, D.

    2009-03-01

    In this note we will discuss the analysis of RHIC run 08 pC data that were collected during February 14 - March 10, 2008. An analysis method that is similar to Run 05 and Run 06 was adopted for Run 08 analysis (except few minor changes, which are described below). A detailed analysis note and a NIM article that describe the pC analysis procedure (for run 05 and run 06) can be found elsewhere. In brief, the analysis consists of calibrating the detectors, determining energy corrections ('dead layers'), determining good runs and extracting the polarization from data.

  15. Effect of morphine on PC12 cells with molecular radar

    NASA Astrophysics Data System (ADS)

    Shi, Chen; Yu, Xiaoli; Lu, Jiuyi; Zhang, Chunyang; Jin, Lei; Ma, Hui; Zhang, Dacheng; Chen, Die Yan

    2000-10-01

    Molecular Radar (MR) is a new method to detect biological processes in living cells at the level of molecular, it is also the newest means to get intracellular information. In this paper we study the effect of morphine on PC12 cells using MR. The results show that the effect of morphine on PC12 cells is time- and concentration-dependent. Morphine treating for short time induces the increase and fluctuation of intracellular (CA2+), while morphine treating for long time induces chromatin condensation, loss of mitochondria membrane potential apoptosis.

  16. PC Windows finite element modeling of landfill gas flow

    SciTech Connect

    Mull, S.R.; Lang, R.J.; Vigil, S.A.; Cota, H.

    1996-09-01

    A two dimensional demonstration program, GAS, has been developed for the solution of landfill gas (LFG) flow problems on a personal computer (PC). The program combines a Windows{trademark} graphical user interface, object oriented programming (OOP) techniques, and finite element modeling (FEM) to demonstrate the practicality of performing LFG flow modeling on the PC. GAS is demonstrated on a sample LFG problem consisting of a landfill, one gas extraction well, the landfill liner, cap, and surrounding soil. Analyses of the program results are performed for successively finer grid resolutions. Element flux imbalance, execution time, and required memory are characterized as a function of grid resolution.

  17. Wf/pc Cycle 1 Calibration: Internal Delta Flats

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This calibration takes internal flats periodically to permit the repair of external (earth-target) flat fields changed by pixel dependent QE changes which occur whenever the WF/PC is decontaminated. Note that the internal flat lamp is also useful with relatively wide filters in the red. This obtains intflats for: WFC: F439W, F547M, F555W, F622W, F702W, F785LP PC: F439W, F547M, F555W, F622W, F702W, F718M, F785LP

  18. Clinical Feasibility of Using an EPID in cine Mode for Image-Guided Verification of Stereotactic Body Radiotherapy

    SciTech Connect

    Berbeco, Ross I.

    2007-09-01

    Purpose: To introduce a novel method for monitoring tumor location during stereotactic body radiotherapy (SBRT) while the treatment beam is on by using a conventional electronic portal imaging device (EPID). Methods and Materials: In our clinic, selected patients were treated under a phase I institutional review board-approved SBRT protocol for limited hepatic metastases from solid tumors. Before treatment planning multiple gold fiducial markers were implanted on the periphery of the tumor. During treatment the EPID was used in cine mode to collect the exit radiation and produce a sequence of images for each field. An in-house program was developed for calculating the location of the fiducials and their relative distance to the planned locations. Results: Three case studies illustrate the utility of the technique. Patient A exhibited a systematic shift of 4 mm during one of the treatment beams. Patient B showed an inferior drift of the target of approximately 1 cm from the time of setup to the end of the fraction. Patient C had a poor setup on the first day of treatment that was quantified and accounted for on subsequent treatment days. Conclusions: Target localization throughout each treatment beam can be quickly assessed with the presented technique. Treatment monitoring with an EPID in cine mode is shown to be a clinically feasible and useful tool.

  19. Quantification of Left Ventricular Volumes, Mass and Ejection Fraction using Cine Displacement Encoding with Stimulated Echoes (DENSE) MRI

    PubMed Central

    Haggerty, Christopher M.; Kramer, Sage P.; Skrinjar, Oskar; Binkley, Cassi M.; Powell, David K.; Mattingly, Andrea C.; Epstein, Frederick H.; Fornwalt, Brandon K.

    2014-01-01

    Purpose To test the hypothesis that magnitude images from cine Displacement Encoding with Stimulated Echoes (DENSE) MRI can accurately quantify left ventricular (LV) volumes, mass, and ejection fraction. Materials and Methods Thirteen mice (C57BL/6J) were imaged using a 7T ClinScan MRI. A short-axis stack of cine T2-weighted black blood (BB) images was acquired for calculation of left ventricular volumes, mass, and ejection fraction (EF) using the gold standard sum-of-slices methodology. DENSE images were acquired during the same imaging session in three short-axis (basal, mid, apical) and two long-axis orientations. A custom surface fitting algorithm was applied to epicardial and endocardial borders from the DENSE magnitude images to calculate volumes, mass, and EF. Agreement between the DENSE-derived measures and BB-derived measures was assessed via coefficient of variation (CoV). Results 3D surface reconstruction was completed on the order of seconds from segmented images, and required fewer slices to be segmented. Volumes, mass, and EF from DENSE-derived surfaces matched well with BB data (CoVs ≤11%). Conclusion LV mass, volumes, and ejection fraction in mice can be quantified through sparse (5 slices) sampling with DENSE. This consolidation significantly reduces the time required to assess both mass/volume-based measures of cardiac function and advanced cardiac mechanics. PMID:24923710

  20. Particle acceleration in flares

    NASA Technical Reports Server (NTRS)

    Benz, Arnold O.; Kosugi, Takeo; Aschwanden, Markus J.; Benka, Steve G.; Chupp, Edward L.; Enome, Shinzo; Garcia, Howard; Holman, Gordon D.; Kurt, Victoria G.; Sakao, Taro

    1994-01-01

    Particle acceleration is intrinsic to the primary energy release in the impulsive phase of solar flares, and we cannot understand flares without understanding acceleration. New observations in soft and hard X-rays, gamma-rays and coherent radio emissions are presented, suggesting flare fragmentation in time and space. X-ray and radio measurements exhibit at least five different time scales in flares. In addition, some new observations of delayed acceleration signatures are also presented. The theory of acceleration by parallel electric fields is used to model the spectral shape and evolution of hard X-rays. The possibility of the appearance of double layers is further investigated.

  1. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-01-01

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  2. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-09-02

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  3. Accelerator-based BNCT.

    PubMed

    Kreiner, A J; Baldo, M; Bergueiro, J R; Cartelli, D; Castell, W; Thatar Vento, V; Gomez Asoia, J; Mercuri, D; Padulo, J; Suarez Sandin, J C; Erhardt, J; Kesque, J M; Valda, A A; Debray, M E; Somacal, H R; Igarzabal, M; Minsky, D M; Herrera, M S; Capoulat, M E; Gonzalez, S J; del Grosso, M F; Gagetti, L; Suarez Anzorena, M; Gun, M; Carranza, O

    2014-06-01

    The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the (9)Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases.

  4. High Gradient Accelerator Research

    SciTech Connect

    Temkin, Richard

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  5. FFAGS for rapid acceleration

    SciTech Connect

    Carol J. Johnstone and Shane Koscielniak

    2002-09-30

    When large transverse and longitudinal emittances are to be transported through a circular machine, extremely rapid acceleration holds the advantage that the beam becomes immune to nonlinear resonances because there is insufficient time for amplitudes to build up. Uncooled muon beams exhibit large emittances and require fast acceleration to avoid decay losses and would benefit from this style of acceleration. The approach here employs a fixed-field alternating gradient or FFAG magnet structure and a fixed frequency acceleration system. Acceptance is enhanced by the use only of linear lattice elements, and fixed-frequency rf enables the use of cavities with large shunt resistance and quality factor.

  6. Acceleration of polarized protons in circular accelerators

    SciTech Connect

    Courant, E.D.; Ruth, R.D.

    1980-09-12

    The theory of depolarization in circular accelerators is presented. The spin equation is first expressed in terms of the particle orbit and then converted to the equivalent spinor equation. The spinor equation is then solved for three different situations: (1) a beam on a flat top near a resonance, (2) uniform acceleration through an isolated resonance, and (3) a model of a fast resonance jump. Finally, the depolarization coefficient, epsilon, is calculated in terms of properties of the particle orbit and the results are applied to a calculation of depolarization in the AGS.

  7. Is High Temporal Resolution Achievable for Paediatric Cardiac Acquisitions during Several Heart Beats? Illustration with Cardiac Phase Contrast Cine-MRI

    PubMed Central

    Bonnemains, Laurent; Odille, Freddy; Meyer, Christophe; Hossu, Gabriella; Felblinger, Jacques; Vuissoz, Pierre-André

    2015-01-01

    Background During paediatric cardiac Cine-MRI, data acquired during cycles of different lengths must be combined. Most of the time, Feinstein’s model is used to project multiple cardiac cycles of variable lengths into a mean cycle. Objective To assess the effect of Feinstein projection on temporal resolution of Cine-MRI. Methods 1/The temporal errors during Feinstein’s projection were computed in 306 cardiac cycles fully characterized by tissue Doppler imaging with 6-phase analysis (from a population of 7 children and young adults). 2/The effects of these temporal errors on tissue velocities were assessed by simulating typical tissue phase mapping acquisitions and reconstructions. 3/Myocardial velocities curves, extracted from high-resolution phase-contrast cine images, were compared for the 6 volunteers with lowest and highest heart rate variability, within a population of 36 young adults. Results 1/The mean of temporal misalignments was 30 ms over the cardiac cycle but reached 60 ms during early diastole. 2/During phase contrast MRI simulation, early diastole velocity peaks were diminished by 6.1 cm/s leading to virtual disappearance of isovolumic relaxation peaks. 3/The smoothing and erasing of isovolumic relaxation peaks was confirmed on tissue phase mapping velocity curves, between subjects with low and high heart rate variability (p = 0.05). Conclusions Feinstein cardiac model creates temporal misalignments that impair high temporal resolution phase contrast cine imaging when beat-to-beat heart rate is changing. PMID:26599755

  8. Molecular Modeling on the PC (by Matthew F. Schlecht)

    NASA Astrophysics Data System (ADS)

    Rioux, Reviewed Frank

    2000-06-01

    "Computeraided molecular modeling doesn't exist for its own sake, but to contribute to scientific endeavor, and enable the scientist to work smarter." This is the last sentence of Schlecht's preface and it says something very important about contemporary scientific research in the academic and industrial venues. Owing to the accelerating improvement in computer technology (hardware and software) and its widespread availability, molecular modeling has become a reliable and important tool in chemical research. Consequently, experimentalists have incorporated molecular modeling techniques in their research, and partnerships with computational chemists have become common. This is a wellorganized and thorough monograph that devotes its attention to one type of molecular modeling, molecular mechanics, and one molecular modeling software package, PCMODEL. Schlecht targets two reader-user groups, the novice and the journeyman modeler, and articulates three goals. He wants to provide the novice with an introduction to molecular mechanics, and after that with some practical examples of the use of empirical force field calculations. His third goal is to provide the journeyman modeler with a reference work that will aid "further study and practice". These are potentially conflicting goals, but Schlecht is, in my opinion, successful because of the way his book is organized. A comprehensive treatment such as this one is not meant to be read from cover to cover, because it is both an exposition of basic principles and a user's manual. Therefore, the novice and the experienced modeler will undoubtedly use this book in different ways. For example, a novice modeler might be advised to read the Preface and Chapter 1, which together provide a broad introduction to the historical development and goals of molecular mechanics. From there the novice could go to Chapter 5 and read section 5.1 on the components of the molecular mechanics force field, which is presented in 22 pages with

  9. FASTRAN II - FATIGUE CRACK GROWTH STRUCTURAL ANALYSIS (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Newman, J. C.

    1994-01-01

    Predictions of fatigue crack growth behavior can be made with the Fatigue Crack Growth Structural Analysis (FASTRAN II) computer program. As cyclic loads are applied to a selected crack configuration with an initial crack size, FASTRAN II predicts crack growth as a function of cyclic load history until either a desired crack size is reached or failure occurs. FASTRAN II is based on plasticity-induced crack-closure behavior of cracks in metallic materials and accounts for load-interaction effects, such as retardation and acceleration, under variable-amplitude loading. The closure model is based on the Dugdale model with modifications to allow plastically deformed material to be left along the crack surfaces as the crack grows. Plane stress and plane strain conditions, as well as conditions between these two, can be simulated in FASTRAN II by using a constraint factor on tensile yielding at the crack front to approximately account for three-dimensional stress states. FASTRAN II contains seventeen predefined crack configurations (standard laboratory fatigue crack growth rate specimens and many common crack configurations found in structures); and the user can define one additional crack configuration. The baseline crack growth rate properties (effective stress-intensity factor against crack growth rate) may be given in either equation or tabular form. For three-dimensional crack configurations, such as surface cracks or corner cracks at holes or notches, the fatigue crack growth rate properties may be different in the crack depth and crack length directions. Final failure of the cracked structure can be modelled with fracture toughness properties using either linear-elastic fracture mechanics (brittle materials), a two-parameter fracture criterion (brittle to ductile materials), or plastic collapse (extremely ductile materials). The crack configurations in FASTRAN II can be subjected to either constant-amplitude, variable-amplitude or spectrum loading. The applied

  10. Immunocytochemical localization of prohormone convertases PC1 and PC2 in the anuran pituitary gland: subcellular localization in corticotrope and melanotrope cells.

    PubMed

    Kurabuchi, S; Tanaka, S

    1997-06-01

    Specific antisera against mammalian prohormone convertases PC1 and PC2 have been used to examine, light-immunocytochemically, the distribution of these enzymes in the pituitary gland of five different species of anuran amphibians (Rana catesbeiana, Bufo japonicus formosus, Xenopus laevis, Rana brevipoda porosa, and Buergeria japonica). A differential pattern of immunoreactivity of PC1 and PC2 was found among these species. Only PC1 was found in the corticotrope cells of the pars distalis in R. catesbeiana, B. japonicus formosus, and X. laevis. Only PC2 was observed in these cells in B. japonica, whereas both PC1 and PC2 were present in these cells in R. brevipoda porosa. PC2 immunoreactivity was always observed in melanotrope cells in the pars intermedia of all of the species, but it coexisted with PC1 immunoreactivity only in R. catesbeiana and X. laevis. The nerve fibers and terminals in the pars nervosa in all of the species were intensely immunopositive with both PC1 and PC2 antibodies. Immunoelectron microscopy on B. japonicus formosus and B. japonica, by means of double-labeling with gold particles of different sizes, revealed that almost all the adrenocorticotropin-positive secretory granules in the corticotrope cells and alpha-melanophore-stimulating-hormone-positive secretory granules in the melanotrope cells were also labeled with either PC1 or PC2 antibodies. This study suggests that PC1 and PC2 are involved in the intracellular proteolytic cleavage of proopiomelanocortin in amphibian pituitary glands, a situation similar to that proposed for mammals.

  11. Processing and intracellular localization of rice stripe virus Pc2 protein in insect cells

    SciTech Connect

    Zhao, Shuling; Zhang, Gaozhan; Dai, Xuejuan; Hou, Yanling; Li, Min; Liang, Jiansheng; Liang, Changyong

    2012-08-01

    Rice stripe virus (RSV) belongs to the genus Tenuivirus and its genome consists of four single-stranded RNAs encoding seven proteins. Here, we have analyzed the processing and membrane association of Pc2 encoded by vcRNA2 in insect cells. The enhanced green fluorescent protein (eGFP) was fused to the Pc2 and used for the detection of Pc2 fusion proteins. The results showed that Pc2 was cleaved to produce two proteins named Pc2-N and Pc2-C. When expressed alone, either Pc2-N or Pc2-C could transport to the Endoplasmic reticulum (ER) membranes independently. Further mutagenesis studies revealed that Pc2 contained three ER-targeting domains. The results led us to propose a model for the topology of the Pc2 in which an internal signal peptide immediately followed a cleavage site, and two transmembrane regions are contained.

  12. Control and optimization of a staged laser-wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Golovin, G.; Banerjee, S.; Chen, S.; Powers, N.; Liu, C.; Yan, W.; Zhang, J.; Zhang, P.; Zhao, B.; Umstadter, D.

    2016-09-01

    We report results of an experimental study of laser-wakefield acceleration of electrons, using a staged device based on a double-jet gas target that enables independent injection and acceleration stages. This novel scheme is shown to produce stable, quasi-monoenergetic, and tunable electron beams. We show that optimal accelerator performance is achieved by systematic variation of five critical parameters. For the injection stage, we show that the amount of trapped charge is controlled by the gas density, composition, and laser power. For the acceleration stage, the gas density and the length of the jet are found to determine the final electron energy. This independent control over both the injection and acceleration processes enabled independent control over the charge and energy of the accelerated electron beam while preserving the quasi-monoenergetic character of the beam. We show that the charge and energy can be varied in the ranges of 2-45 pC, and 50-450 MeV, respectively. This robust and versatile electron accelerator will find application in the generation of high-brightness and controllable x-rays, and as the injector stage for more conventional devices.

  13. Scaling FFAG accelerator for muon acceleration

    SciTech Connect

    Lagrange, JB.; Planche, T.; Mori, Y.

    2011-10-06

    Recent developments in scaling fixed field alternating gradient (FFAG) accelerators have opened new ways for lattice design, with straight sections, and insertions like dispersion suppressors. Such principles and matching issues are detailed in this paper. An application of these new concepts is presented to overcome problems in the PRISM project.

  14. Scaling FFAG accelerator for muon acceleration

    NASA Astrophysics Data System (ADS)

    Lagrange, JB.; Planche, T.; Mori, Y.

    2011-10-01

    Recent developments in scaling fixed field alternating gradient (FFAG) accelerators have opened new ways for lattice design, with straight sections, and insertions like dispersion suppressors. Such principles and matching issues are detailed in this paper. An application of these new concepts is presented to overcome problems in the PRISM project.

  15. Angular velocities, angular accelerations, and coriolis accelerations

    NASA Technical Reports Server (NTRS)

    Graybiel, A.

    1975-01-01

    Weightlessness, rotating environment, and mathematical analysis of Coriolis acceleration is described for man's biological effective force environments. Effects on the vestibular system are summarized, including the end organs, functional neurology, and input-output relations. Ground-based studies in preparation for space missions are examined, including functional tests, provocative tests, adaptive capacity tests, simulation studies, and antimotion sickness.

  16. Accelerators for Discovery Science and Security applications

    NASA Astrophysics Data System (ADS)

    Todd, A. M. M.; Bluem, H. P.; Jarvis, J. D.; Park, J. H.; Rathke, J. W.; Schultheiss, T. J.

    2015-05-01

    Several Advanced Energy Systems (AES) accelerator projects that span applications in Discovery Science and Security are described. The design and performance of the IR and THz free electron laser (FEL) at the Fritz-Haber-Institut der Max-Planck-Gesellschaft in Berlin that is now an operating user facility for physical chemistry research in molecular and cluster spectroscopy as well as surface science, is highlighted. The device was designed to meet challenging specifications, including a final energy adjustable in the range of 15-50 MeV, low longitudinal emittance (<50 keV-psec) and transverse emittance (<20 π mm-mrad), at more than 200 pC bunch charge with a micropulse repetition rate of 1 GHz and a macropulse length of up to 15 μs. Secondly, we will describe an ongoing effort to develop an ultrafast electron diffraction (UED) source that is scheduled for completion in 2015 with prototype testing taking place at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF). This tabletop X-band system will find application in time-resolved chemical imaging and as a resource for drug-cell interaction analysis. A third active area at AES is accelerators for security applications where we will cover some top-level aspects of THz and X-ray systems that are under development and in testing for stand-off and portal detection.

  17. Caffeine accelerates recovery from general anesthesia.

    PubMed

    Wang, Qiang; Fong, Robert; Mason, Peggy; Fox, Aaron P; Xie, Zheng

    2014-03-01

    General anesthetics inhibit neurotransmitter release from both neurons and secretory cells. If inhibition of neurotransmitter release is part of an anesthetic mechanism of action, then drugs that facilitate neurotransmitter release may aid in reversing general anesthesia. Drugs that elevate intracellular cAMP levels are known to facilitate neurotransmitter release. Three cAMP elevating drugs (forskolin, theophylline, and caffeine) were tested; all three drugs reversed the inhibition of neurotransmitter release produced by isoflurane in PC12 cells in vitro. The drugs were tested in isoflurane-anesthetized rats. Animals were injected with either saline or saline containing drug. All three drugs dramatically accelerated recovery from isoflurane anesthesia, but caffeine was most effective. None of the drugs, at the concentrations tested, had significant effects on breathing rates, O2 saturation, heart rate, or blood pressure in anesthetized animals. Caffeine alone was tested on propofol-anesthetized rats where it dramatically accelerated recovery from anesthesia. The ability of caffeine to accelerate recovery from anesthesia for different chemical classes of anesthetics, isoflurane and propofol, opens the possibility that it will do so for all commonly used general anesthetics, although additional studies will be required to determine whether this is in fact the case. Because anesthesia in rodents is thought to be similar to that in humans, these results suggest that caffeine might allow for rapid and uniform emergence from general anesthesia in human patients.

  18. Induction linear accelerators

    NASA Astrophysics Data System (ADS)

    Birx, Daniel

    1992-03-01

    Among the family of particle accelerators, the Induction Linear Accelerator is the best suited for the acceleration of high current electron beams. Because the electromagnetic radiation used to accelerate the electron beam is not stored in the cavities but is supplied by transmission lines during the beam pulse it is possible to utilize very low Q (typically<10) structures and very large beam pipes. This combination increases the beam breakup limited maximum currents to of order kiloamperes. The micropulse lengths of these machines are measured in 10's of nanoseconds and duty factors as high as 10-4 have been achieved. Until recently the major problem with these machines has been associated with the pulse power drive. Beam currents of kiloamperes and accelerating potentials of megavolts require peak power drives of gigawatts since no energy is stored in the structure. The marriage of liner accelerator technology and nonlinear magnetic compressors has produced some unique capabilities. It now appears possible to produce electron beams with average currents measured in amperes, peak currents in kiloamperes and gradients exceeding 1 MeV/meter, with power efficiencies approaching 50%. The nonlinear magnetic compression technology has replaced the spark gap drivers used on earlier accelerators with state-of-the-art all-solid-state SCR commutated compression chains. The reliability of these machines is now approaching 1010 shot MTBF. In the following paper we will briefly review the historical development of induction linear accelerators and then discuss the design considerations.

  19. Accelerator Science: Why RF?

    SciTech Connect

    Lincoln, Don

    2016-12-21

    Particle accelerators can fire beams of subatomic particles at near the speed of light. The accelerating force is generated using radio frequency technology and a whole lot of interesting features. In this video, Fermilab’s Dr. Don Lincoln explains how it all works.

  20. Particle Acceleration in Jets

    NASA Technical Reports Server (NTRS)

    Nishikawa, Ken-Ichi

    2005-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., active galactic nuclei (AGNs), gamma ray burst (GRBs), and Galactic microquasar systems usually have power-law emission spectra. Fermi acceleration is the mechanism usually assumed for the acceleration of particles in astrophysical environments.

  1. Accelerators Beyond The Tevatron?

    SciTech Connect

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  2. Accelerators (3/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  3. Diagnostics for induction accelerators

    SciTech Connect

    Fessenden, T.J.

    1996-04-01

    The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960`s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore`s Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail.

  4. Accelerators (4/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  5. Measuring Model Rocket Acceleration.

    ERIC Educational Resources Information Center

    Jenkins, Randy A.

    1993-01-01

    Presents an experiment that measures the acceleration and velocity of a model rocket. Lift-off information is transmitted to a computer that creates a graph of the velocity. Discusses the analysis of the computer-generated data and differences between calculated and experimental velocity and acceleration of several rocket types. (MDH)

  6. Microscale acceleration history discriminators

    DOEpatents

    Polosky, Marc A.; Plummer, David W.

    2002-01-01

    A new class of micromechanical acceleration history discriminators is claimed. These discriminators allow the precise differentiation of a wide range of acceleration-time histories, thereby allowing adaptive events to be triggered in response to the severity (or lack thereof) of an external environment. Such devices have applications in airbag activation, and other safety and surety applications.

  7. Accelerators (5/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  8. Accelerators Beyond The Tevatron?

    SciTech Connect

    Lach, Joseph

    2010-07-29

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?.

  9. PC Board Layout and Electronic Drafting with CAD. Teacher Edition.

    ERIC Educational Resources Information Center

    Bryson, Jimmy

    This teacher's guide contains 11 units of instruction for a course on computer electronics and computer-assisted drafting (CAD) using a personal computer (PC). The course covers the following topics: introduction to electronic drafting with CAD; CAD system and software; basic electronic theory; component identification; basic integrated circuit…

  10. Audio Podcasting in a Tablet PC-Enhanced Biochemistry Course

    ERIC Educational Resources Information Center

    Lyles, Heather; Robertson, Brian; Mangino, Michael; Cox, James R.

    2007-01-01

    This report describes the effects of making audio podcasts of all lectures in a large, basic biochemistry course promptly available to students. The audio podcasts complement a previously described approach in which a tablet PC is used to annotate PowerPoint slides with digital ink to produce electronic notes that can be archived. The fundamentals…

  11. Using a PC as a Frequency Meter or a Counter.

    ERIC Educational Resources Information Center

    Sartori, J.; And Others

    1995-01-01

    Describes hardware that enables the use of an IBM PC microcomputer as a frequency meter or a counter by using the parallel printer port. Eliminates the 16-bit time-day counter through the use of an external time base that can be conveniently set depending on the desired frequency range. (JRH)

  12. Teaching Mathematics in the PC Lab--The Students' Viewpoints

    ERIC Educational Resources Information Center

    Schmidt, Karsten; Kohler, Anke

    2013-01-01

    The Matrix Algebra portion of the intermediate mathematics course at the Schmalkalden University Faculty of Business and Economics has been moved from a traditional classroom setting to a technology-based setting in the PC lab. A Computer Algebra System license was acquired that also allows its use on the students' own PCs. A survey was carried…

  13. A PC-based Workstation for Robotic Discectomy

    NASA Technical Reports Server (NTRS)

    Casadei, C.; Fiorini, P.; Martelli, S.; Montanari, M.; Morri, A.

    1998-01-01

    Ths paper describes a PC-based controller for robot-assisted minimally invasive surgery. The development is motivated by the need of reducing the exposure of operating room personnel to X-rays during surgical procedures such as percutanrous discectomy.

  14. An Apple for Your IBM PC--The Quadlink Board.

    ERIC Educational Resources Information Center

    Owen, G. Scott

    1984-01-01

    Describes nature and installation of the QUADLINK board which allows Apple software to be run on IBM PC microcomputers. Although programs tested ran without problems, users should test their own programs since there are some copy protection schemes that can baffle the board. (JN)

  15. What's Under Your PC's 'Hood': A Primer for Today's Machines.

    ERIC Educational Resources Information Center

    Chen, Li; Mills, Joyce White

    2002-01-01

    Explains how to decide what type of computer to buy for a small academic library, based on software requirements, staff and patron use, and PC technology. Topics include the central processing unit; types of memory; storage devices; ports; multimedia capabilities; modems; operating systems; and monitors. (LRW)

  16. Electronic States of IC60BA and PC71BM

    NASA Astrophysics Data System (ADS)

    Sheng, Chun-Qi; Wang, Peng; Shen, Ying; Li, Wen-Jie; Zhang, Wen-Hua; Zhu, Jun-Fa; Lai, Guo-Qiao; Li, Hong-Nian

    2013-11-01

    We investigate the electronic states of IC60BA and PC71BM using first-principles calculations and photoelectron spectroscopy (PES) measurements. The energy level structures for all possible isomers are reported and compared with those of C60, C70 and PC61BM. The attachment of the side chains can raise the LUMO energies and decrease the HOMO-LUMO gaps, and thus helps to increase the power-conversion efficiency of bulk heterojunction solar cells. In the PES studies, we prepared IC60BA and PC71BM films on Si:H(111) substrates to construct adsorbate/substrate interfaces describable with the integer charge-transfer (ICT) model. Successful measurements then revealed that one of the most important material properties for an electron acceptor, the energy of the negative integer charge-transfer state (EICT-), is 4.31 eV below the vacuum level for PC71BM. The EICT- of IC60BA is smaller than 4.14 eV.

  17. Wf/pc Cycle 2 Calib: Single Chip UV Calibration

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1991-07-01

    THIS PROGRAM CALIBRATES THE QE OF THE WFC AND PC IN THE ULTRAVIOLET (F194W, F230W, AND F284W). This calibration is done using exposures of a UV flux standard star. This program is intended for use only following a UV decontamination.

  18. Wf/pc Cycle 1 Calib: 4-CHIP UV Calibration

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    THIS PROGRAM CALIBRATES THE QE OF THE WFC AND PC IN THE ULTRAVIOLET (F194W, F230W, AND F284W). This calibration is done for each CCD detector using exposures of a UV flux standard star. This program is intended for use only during a UV campaign.

  19. 39 CFR 501.16 - PC postage payment methodology.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... examination of its PC Postage system and any other applications and technology infrastructure that may have a... organization uses another service organization (sub-service provider), Postal Service Management should... contribution of the sub-service organization's processes and controls in the achievement of the Postal...

  20. 39 CFR 501.16 - PC postage payment methodology.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... examination of its PC Postage system and any other applications and technology infrastructure that may have a... organization uses another service organization (sub-service provider), Postal Service Management should... contribution of the sub-service organization's processes and controls in the achievement of the Postal...

  1. 39 CFR 501.16 - PC postage payment methodology.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... examination of its PC Postage system and any other applications and technology infrastructure that may have a... uses another service organization (sub-service provider), Postal Service management should consider the... of the sub-service organization's processes and controls in the achievement of the Postal...

  2. Multi-Purpose, Multi-Reservoir Simulation on a PC

    DTIC Science & Technology

    1988-08-01

    The methodology and difficulties in converting a large, general purpose, mainframe, batch oriented computer program (for reservoir simulation ) to...work effectively in the PC environment are described in this paper. A brief overview of the present capabilities of the general purpose reservoir ... simulation program (HEC-5), that works on mainframe and MS DOS compatible computers, is also presented. Keywords: Simulation, Personal computer, Reservior

  3. PC-CUBE: A Personal Computer Based Hypercube

    NASA Technical Reports Server (NTRS)

    Ho, Alex; Fox, Geoffrey; Walker, David; Snyder, Scott; Chang, Douglas; Chen, Stanley; Breaden, Matt; Cole, Terry

    1988-01-01

    PC-CUBE is an ensemble of IBM PCs or close compatibles connected in the hypercube topology with ordinary computer cables. Communication occurs at the rate of 115.2 K-band via the RS-232 serial links. Available for PC-CUBE is the Crystalline Operating System III (CrOS III), Mercury Operating System, CUBIX and PLOTIX which are parallel I/O and graphics libraries. A CrOS performance monitor was developed to facilitate the measurement of communication and computation time of a program and their effects on performance. Also available are CXLISP, a parallel version of the XLISP interpreter; GRAFIX, some graphics routines for the EGA and CGA; and a general execution profiler for determining execution time spent by program subroutines. PC-CUBE provides a programming environment similar to all hypercube systems running CrOS III, Mercury and CUBIX. In addition, every node (personal computer) has its own graphics display monitor and storage devices. These allow data to be displayed or stored at every processor, which has much instructional value and enables easier debugging of applications. Some application programs which are taken from the book Solving Problems on Concurrent Processors (Fox 88) were implemented with graphics enhancement on PC-CUBE. The applications range from solving the Mandelbrot set, Laplace equation, wave equation, long range force interaction, to WaTor, an ecological simulation.

  4. Wf/pc Cycle 1 CALIBRATION:UV Flats 1

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This program takes "uniform illuminated" pictures of the earth to obtain the "instrument signature" for flat field corrections for the UV filters. The camera - filter combinations done in this proposal are: WFC: F194W, F230W, F284W PC: F194W, F230W, F284W This calibration should be part of each UV campaign.

  5. Deciding when It's Time to Buy a New PC

    ERIC Educational Resources Information Center

    Goldsborough, Reid

    2004-01-01

    How to best decide when it's time to replace your PC, whether at home or at work, is always tricky. Spending on computers can make you more productive, but it's money you otherwise cannot spend, invest or save, and faster systems always await you in the future. What is clear is that the computer industry really wants you to buy, and the computer…

  6. 36. View of preset counter (PC) console and tracking console ...

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

    36. View of preset counter (PC) console and tracking console on right, located in MWOC facility in transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  7. PC vs. Mac--Which Way Should You Go?

    ERIC Educational Resources Information Center

    Wodarz, Nan

    1997-01-01

    Outlines the factors in hardware, software, and administration to consider in developing specifications for choosing a computer operating system. Compares Microsoft Windows 95/NT that runs on PC/Intel-based systems and System 7.5 that runs on the Apple-based systems. Lists reasons why the Microsoft platform clearly stands above the Apple platform.…

  8. Privacy Impact Assessment for the PC Label System

    EPA Pesticide Factsheets

    The PC Label System collects contact information for individuals with an interest in EPA's Region 1. Learn how this data will be collected in the system, how it will be used, access to the data, the purpose of data collection, and record retention policies

  9. A fast CT reconstruction scheme for a general multi-core PC.

    PubMed

    Zeng, Kai; Bai, Erwei; Wang, Ge

    2007-01-01

    Expensive computational cost is a severe limitation in CT reconstruction for clinical applications that need real-time feedback. A primary example is bolus-chasing computed tomography (CT) angiography (BCA) that we have been developing for the past several years. To accelerate the reconstruction process using the filtered backprojection (FBP) method, specialized hardware or graphics cards can be used. However, specialized hardware is expensive and not flexible. The graphics processing unit (GPU) in a current graphic card can only reconstruct images in a reduced precision and is not easy to program. In this paper, an acceleration scheme is proposed based on a multi-core PC. In the proposed scheme, several techniques are integrated, including utilization of geometric symmetry, optimization of data structures, single-instruction multiple-data (SIMD) processing, multithreaded computation, and an Intel C++ compilier. Our scheme maintains the original precision and involves no data exchange between the GPU and CPU. The merits of our scheme are demonstrated in numerical experiments against the traditional implementation. Our scheme achieves a speedup of about 40, which can be further improved by several folds using the latest quad-core processors.

  10. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    SciTech Connect

    Siemann, R.H.; /SLAC

    2011-10-24

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  11. A robust automated left ventricle region of interest localization technique using a cardiac cine MRI atlas

    NASA Astrophysics Data System (ADS)

    Ben-Zikri, Yehuda Kfir; Linte, Cristian A.

    2016-03-01

    Region of interest detection is a precursor to many medical image processing and analysis applications, including segmentation, registration and other image manipulation techniques. The optimal region of interest is often selected manually, based on empirical knowledge and features of the image dataset. However, if inconsistently identified, the selected region of interest may greatly affect the subsequent image analysis or interpretation steps, in turn leading to incomplete assessment during computer-aided diagnosis or incomplete visualization or identification of the surgical targets, if employed in the context of pre-procedural planning or image-guided interventions. Therefore, the need for robust, accurate and computationally efficient region of interest localization techniques is prevalent in many modern computer-assisted diagnosis and therapy applications. Here we propose a fully automated, robust, a priori learning-based approach that provides reliable estimates of the left and right ventricle features from cine cardiac MR images. The proposed approach leverages the temporal frame-to-frame motion extracted across a range of short axis left ventricle slice images with small training set generated from les than 10% of the population. This approach is based on histogram of oriented gradients features weighted by local intensities to first identify an initial region of interest depicting the left and right ventricles that exhibits the greatest extent of cardiac motion. This region is correlated with the homologous region that belongs to the training dataset that best matches the test image using feature vector correlation techniques. Lastly, the optimal left ventricle region of interest of the test image is identified based on the correlation of known ground truth segmentations associated with the training dataset deemed closest to the test image. The proposed approach was tested on a population of 100 patient datasets and was validated against the ground truth

  12. Method of Quantifying Three Dimensional Strain Distribution in Skeletal Muscle Using Cine Phase Contrast MRI

    PubMed Central

    Jensen, Elisabeth R.; Morrow, Duane A.; Felmlee, Joel P.; Murthy, Naveen S.; Kaufman, Kenton R.

    2016-01-01

    Intramuscular pressure (IMP), a correlate of muscle tension, may fill an important clinical testing void. A barrier to implementing this measure clinically is its non-uniform distribution, which is not fully understood. Pressure is generated by changes in fluid mass and volume, therefore 3D volumetric strain distribution may affect IMP distribution. The purpose of this study was to develop a method for quantifying 3D volumetric strain distribution in the human tibialis anterior (TA) during passive tension using cine Phase Contrast (CPC) MRI and to assess its accuracy and precision. Five healthy subjects each participated in three data collections. A custom MRI-compatible apparatus repeatedly rotated the subjects’ ankle between 0 and 26 degrees plantarflexion while CPC MRI data were collected. Additionally, T2-weighted images of the lower leg were collected both before and after the CPC data collection with the ankle stationary at both 0 and 26 degrees plantarflexion for TA muscle segmentation. A 3D hexahedral mesh was generated based on the TA surface before CPC data collection with the ankle at 0 degrees plantarflexion and the node trajectories were tracked using the CPC data. The volumetric strain of each element was quantified. Three tests were employed to assess the measure accuracy and precision. First, to quantify leg position drift, the TA segmentations were compared before and after CPC data collection. This error was 1.5±0.7 mm. Second, to assess the surface node trajectory accuracy, the deformed mesh surface was compared to the TA segmented at 26 degrees of ankle plantarflexion. This error was 0.6±0.2 mm. Third, the standard deviation of volumetric strain across the three data collections was calculated for each element and subject. The median between-day variability across subjects and mesh elements was 0.06 mm3/mm3 (95% confidence interval 0.01 to 0.18 mm3/mm3). Overall the results demonstrated excellent accuracy and precision. PMID:26595686

  13. Real-time SPARSE-SENSE cine MR imaging in atrial fibrillation: a feasibility study.

    PubMed

    Goebel, Juliane; Nensa, Felix; Schemuth, Haemi P; Maderwald, Stefan; Quick, Harald H; Schlosser, Thomas; Nassenstein, Kai

    2016-01-01

    Background Cardiac magnetic resonance imaging (MRI) relies on correct ECG-gating, which is hindered in arrhythmia. Purpose To examine whether a prototype free-breathing real-time cine sequence using SPARSE-SENSE (SPARSE) improves left ventricular quantification in atrial fibrillation. Material and Methods On a 1.5T MR system left ventricular short-axis stacks were acquired of the SPARSE sequence and of a "reference" steady-state free precession (SSFP) sequence with arrhythmia rejection in 20 patients with atrial fibrillation. Two radiologists independently rated arrhythmia-caused artifact severity in both sequences using a 4-point scale. Coefficients of variation of myocardial signal intensity for both sequences were acquired. Volumetry was performed twice by one reader and once by another reader. Correlation between artifact severity and employed sequence was analyzed by modified Fisher's exact test. Coefficients of variation and volumetric data were compared by paired t-test and intraclass correlation. Results Median arrhythmia-caused artifact severity was 2 in both readers for SSFP and 0 (reader 1)/1 (reader 2) for SPARSE, being significantly lower in SPARSE ( P < 0.001). Mean coefficient of variance was significantly smaller in SPARSE (0.11 ± 0.04) compared to SSFP (0.22 ± 0.13, P = 0.003), which was interpreted as a hint for fewer artifacts in SPARSE. Only a small difference of 9 ± 15 mL was seen for end-systolic volume ( P = 0.019) between sequences, otherwise no significant difference was detected (end-diastolic volume, P = 0.200; stroke volume, P = 0.554; ejection fraction, P = 0.136; myocardial mass, P = 0.353). Intraclass correlation between sequences was good to excellent (range, 0.80-0.97). Conclusion Real-time MRI with SPARSE data sampling is promising in atrial fibrillation because it reduces arrhythmia-caused artifacts.

  14. Induction of cytoprotective autophagy in PC-12 cells by cadmium

    SciTech Connect

    Wang, Qiwen; Zhu, Jiaqiao; Zhang, Kangbao; Jiang, Chenyang; Wang, Yi; Yuan, Yan; Bian, Jianchun; Liu, Xuezhong; Gu, Jianhong; Liu, Zongping

    2013-08-16

    Highlights: •Cadmium can promote early upregulation of autophagy in PC-12 cells. •Autophagy precedes apoptosis in cadmium-treated PC-12 cells. •Cadmium-induced autophagy is cytoprotective in PC-12 cells. •Class III PI3K/beclin-1/Bcl-2 signaling pathway plays a positive role in cadmium-triggered autophagy. -- Abstract: Laboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity.

  15. IPEG- IMPROVED PRICE ESTIMATION GUIDELINES (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Aster, R. W.

    1994-01-01

    The Improved Price Estimation Guidelines, IPEG, program provides a simple yet accurate estimate of the price of a manufactured product. IPEG facilitates sensitivity studies of price estimates at considerably less expense than would be incurred by using the Standard Assembly-line Manufacturing Industry Simulation, SAMIS, program (COSMIC program NPO-16032). A difference of less than one percent between the IPEG and SAMIS price estimates has been observed with realistic test cases. However, the IPEG simplification of SAMIS allows the analyst with limited time and computing resources to perform a greater number of sensitivity studies than with SAMIS. Although IPEG was developed for the photovoltaics industry, it is readily adaptable to any standard assembly line type of manufacturing industry. IPEG estimates the annual production price per unit. The input data includes cost of equipment, space, labor, materials, supplies, and utilities. Production on an industry wide basis or a process wide basis can be simulated. Once the IPEG input file is prepared, the original price is estimated and sensitivity studies may be performed. The IPEG user selects a sensitivity variable and a set of values. IPEG will compute a price estimate and a variety of other cost parameters for every specified value of the sensitivity variable. IPEG is designed as an interactive system and prompts the user for all required information and offers a variety of output options. The IPEG/PC program is written in TURBO PASCAL for interactive execution on an IBM PC computer under DOS 2.0 or above with at least 64K of memory. The IBM PC color display and color graphics adapter are needed to use the plotting capabilities in IPEG/PC. IPEG/PC was developed in 1984. The original IPEG program is written in SIMSCRIPT II.5 for interactive execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 300K of 8 bit bytes. The original IPEG was developed in 1980.

  16. Surface aspects of discolouration in Bisphenol A Polycarbonate (BPA-PC), used as lens in LED-based products

    NASA Astrophysics Data System (ADS)

    Yazdan Mehr, M.; van Driel, W. D.; Udono, H.; Zhang, G. Q.

    2014-11-01

    The surface-related reactions during discolouration of Bisphenol A Polycarbonate (BPA-PC), used as LED lens plates, under thermal stress are studied. X-ray photoelectron spectroscopy (XPS) has been used to monitor the changes in the surface chemistry of BPA-PC plates over a temperature range of 100-140 °C for a period up to 3000 h. Increasing time under thermal stress is associated with the discolouration, and increase in the yellowing index (YI) of PC plastic lens. The XPS results show that discolouration is associated with oxidation at the surface, finding a significant increase in the signal ratio O1s/C1s in the XPS spectra of degraded specimens. During thermal ageing, the Csbnd H concentration decreases and new oxide features Cdbnd O and Osbnd Cdbnd O form, with the latter being a support for oxidation at the surface being a major reaction during discolouration. Results also show that irradiation with blue light during thermal ageing accelerates the kinetics of discolouration and the increased O1s/C1s ratio in XPS spectra.

  17. Surface-type nonvolatile electric memory elements based on organic-on-organic CuPc-H2Pc heterojunction

    NASA Astrophysics Data System (ADS)

    Khasan, S. Karimov; Zubair, Ahmad; Farid, Touati; Mahroof-Tahir, M.; M. Muqeet, Rehman; S. Zameer, Abbas

    2015-11-01

    A novel surface-type nonvolatile electric memory elements based on organic semiconductors CuPc and H2Pc are fabricated by vacuum deposition of the CuPc and H2Pc films on preliminary deposited metallic (Ag and Cu) electrodes. The gap between Ag and Cu electrodes is 30-40 μm. For the current-voltage (I-V) characteristics the memory effect, switching effect, and negative differential resistance regions are observed. The switching mechanism is attributed to the electric-field-induced charge transfer. As a result the device switches from a low to a high-conductivity state and then back to a low conductivity state if the opposite polarity voltage is applied. The ratio of resistance at the high resistance state to that at the low resistance state is equal to 120-150. Under the switching condition, the electric current increases ˜ 80-100 times. A comparison between the forward and reverse I-V characteristics shows the presence of rectifying behavior. Project supported by the GIK Institute of Engineering Science and Technology, Pakistan and Physical Technical Institute of Academy of Sciences of Tajikistan.

  18. Chromosomal assignment of the genes for proprotein convertases PC4, PC5, and PACE 4 in mouse and human.

    PubMed

    Mbikay, M; Seidah, N G; Chrétien, M; Simpson, E M

    1995-03-01

    The genes for three subtilisin/kexin-like proprotein convertases, PC4, PC5, and PACE4, were mapped in the mouse by RFLP analysis of a DNA panel from a (C57BL/6JEi x SPRET/Ei)F1 x SPRET/Ei backcross. The chromosomal locations of the human homologs were determined by Southern blot analysis of a DNA panel from human-rodent somatic cell hybrids, most of which contained a single human chromosome each. The gene for PC4 (Pcsk4 locus) mapped to mouse chromosome 10, close to the Adn (adipsin, a serine protease) locus and near the Amh (anti-müllerian hormone) locus; in human, the gene was localized to chromosome 19. The gene for PC5 (Pcsk5 locus) mapped to mouse chromosome 19 close to the Lpc1 (lipocortin-1) locus and, in human, was localized to chromosome 9. The gene for PACE4 (Pcsk6 locus) mapped to mouse chromosome 7, at a distance of 13 cM from the Pcsk3 locus, which specifies furin, another member of this family of enzymes previously mapped to this chromosome. This is in concordance with the known close proximity of these two loci in the homologous region on human chromosome 15q25-qter. Pcsk3 and Pcsk6 mapped to a region of mouse chromosome 7 that has been associated cytogenetically with postnatal lethality in maternal disomy, suggesting that these genes might be candidates for imprinting.

  19. SU-C-17A-05: Quantification of Intra-Fraction Motion of Breast Tumors Using Cine-MRI

    SciTech Connect

    Heijst, T van; Philippens, M; Bongard, D van den; Asselen, B van; Lagendijk, J; Kleijnen, J; Hartogh, M den

    2014-06-01

    Purpose: Magnetic resonance imaging (MRI) enables direct characterization of intra-fraction motion ofbreast tumors, due to high softtissue contrast and geometric accuracy. The purpose is to analyzethis motion in early-stage breast-cancer patients using pre-operative supine cine-MRI. Methods: MRI was performed in 12 female early-stage breast-cancer patients on a 1.5-T Ingenia (Philips)wide-bore scanner in supine radiotherapy (RT) position, prior to breast-conserving surgery. Twotwodimensional (2D) T2-weighted balanced fast-field echo (cine-MRI) sequences were added tothe RT protocol, oriented through the tumor. They were alternately acquired in the transverse andsagittal planes, every 0.3 s during 1 min. A radiation oncologist delineated gross target volumes(GTVs) on 3D contrast-enhanced MRI. Clinical target volumes (CTV = GTV + 15 mm isotropic)were generated and transferred onto the fifth time-slice of the time-series, to which subsequents lices were registered using a non-rigid Bspline algorithm; delineations were transformed accordingly. To evaluate intra-fraction CTV motion, deformation fields between the transformed delineations were derived to acquire the distance ensuring 95% surface coverage during scanning(P95%), for all in-plane directions: anteriorposterior (AP), left-right (LR), and caudal-cranial(CC). Information on LR was derived from transverse scans, CC from sagittal scans, AP fromboth sets. Results: Time-series with registration errors - induced by motion artifacts - were excluded by visual inspection. For our analysis, 11 transverse, and 8 sagittal time-series were taken into account. Themedian P95% calculated in AP (19 series), CC (8), and LR (11) was 1.8 mm (range: 0.9–4.8), 1.7mm (0.8–3.6), and 1.0 mm (0.6–3.5), respectively. Conclusion: Intra-fraction motion analysis of breast tumors was achieved using cine-MRI. These first results show that in supine RT position, motion amplitudes are limited. This information can be used for adaptive RT

  20. Large electrostatic accelerators

    SciTech Connect

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators.

  1. CARES/PC - CERAMICS ANALYSIS AND RELIABILITY EVALUATION OF STRUCTURES

    NASA Technical Reports Server (NTRS)

    Szatmary, S. A.

    1994-01-01

    The beneficial properties of structural ceramics include their high-temperature strength, light weight, hardness, and corrosion and oxidation resistance. For advanced heat engines, ceramics have demonstrated functional abilities at temperatures well beyond the operational limits of metals. This is offset by the fact that ceramic materials tend to be brittle. When a load is applied, their lack of significant plastic deformation causes the material to crack at microscopic flaws, destroying the component. CARES/PC performs statistical analysis of data obtained from the fracture of simple, uniaxial tensile or flexural specimens and estimates the Weibull and Batdorf material parameters from this data. CARES/PC is a subset of the program CARES (COSMIC program number LEW-15168) which calculates the fast-fracture reliability or failure probability of ceramic components utilizing the Batdorf and Weibull models to describe the effects of multi-axial stress states on material strength. CARES additionally requires that the ceramic structure be modeled by a finite element program such as MSC/NASTRAN or ANSYS. The more limited CARES/PC does not perform fast-fracture reliability estimation of components. CARES/PC estimates ceramic material properties from uniaxial tensile or from three- and four-point bend bar data. In general, the parameters are obtained from the fracture stresses of many specimens (30 or more are recommended) whose geometry and loading configurations are held constant. Parameter estimation can be performed for single or multiple failure modes by using the least-squares analysis or the maximum likelihood method. Kolmogorov-Smirnov and Anderson-Darling goodness-of-fit tests measure the accuracy of the hypothesis that the fracture data comes from a population with a distribution specified by the estimated Weibull parameters. Ninety-percent confidence intervals on the Weibull parameters and the unbiased value of the shape parameter for complete samples are provided

  2. METHANE de-NOX for Utility PC Boilers

    SciTech Connect

    Bruce Bryan; Serguei Nester; Joseph Rabovitser; Stan Wohadlo

    2005-09-30

    The overall project objective is the development and validation of an innovative combustion system, based on a novel coal preheating concept prior to combustion, that can reduce NO{sub x} emissions to 0.15 lb/million Btu or less on utility pulverized coal (PC) boilers. This NO{sub x} reduction should be achieved without loss of boiler efficiency or operating stability, and at more than 25% lower levelized cost than state-of-the-art SCR technology. A further objective is to ready technology for full-scale commercial deployment to meet the market demand for NO{sub x} reduction technologies. Over half of the electric power generated in the U.S. is produced by coal combustion, and more than 80% of these units utilize PC combustion technology. Conventional measures for NOx reduction in PC combustion processes rely on combustion and post-combustion modifications. A variety of combustion-based NO{sub x} reduction technologies are in use today, including low-NO{sub x} burners (LNBs), flue gas recirculation (FGR), air staging, and natural gas or other fuel reburning. Selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) are post-combustion techniques. NO{sub x} reduction effectiveness from these technologies ranges from 30 to 60% and up to 90-93% for SCR. Typically, older wall-fired PC burner units produce NO{sub x} emissions in the range of 0.8-1.6 lb/million Btu. Low-NO{sub x} burner systems, using combinations of fuel staging within the burner and air staging by introduction of overfire air in the boiler, can reduce NO{sub x} emissions by 50-60%. This approach alone is not sufficient to meet the desired 0.15 lb/million Btu NO{sub x} standard with a range of coals and boiler loads. Furthermore, the heavy reliance on overfire air can lead to increased slagging and corrosion in furnaces, particularly with higher-sulfur coals, when LNBs are operated at sub-stoichiometric conditions to reduce fuel-derived NOx in the flame. Therefore, it is desirable

  3. The muon component in extensive air showers and new p+C data in fixed target experiments

    SciTech Connect

    Meurer, C.; Bluemer, J.; Engel, R.; Haungs, A.; Roth, M.

    2007-03-19

    One of the most promising approaches to determine the energy spectrum and composition of the cosmic rays with energies above 1015 eV is the measurement of the number of electrons and muons produced in extensive air showers (EAS). Therefore simulation of air showers using electromagnetic and hadronic interaction models are necessary. These simulations show uncertainties which come mainly from hadronic interaction models. One aim of this work is to specify the low energy hadronic interactions which are important for the muon production in EAS. Therefore we simulate extensive air showers with a modified version of the simulation package CORSIKA. In particular we investigate in detail the energy and the phase space regions of secondary particle production, which are most important for muon production. This phase space region is covered by fixed target experiments at CERN. In the second part of this work we present preliminary momentum spectra of secondary {pi}+ and {pi}- in p+C collisions at 12 GeV/c measured with the HARP spectrometer at the PS accelerator at CERN. In addition we use the new p+C NA49 data at 158 GeV/c to check the reliability of hadronic interaction models for muon production in EAS. Finally, possibilities to measure relevant quantities of hadron production in existing and planned accelerator experiments are discussed.

  4. The secretory proprotein convertases furin, PC5, and PC7 activate VEGF-C to induce tumorigenesis

    PubMed Central

    Siegfried, Geraldine; Basak, Ajoy; Cromlish, James A.; Benjannet, Suzanne; Marcinkiewicz, Jadwiga; Chrétien, Michel; Seidah, Nabil G.; Khatib, Abdel-Majid

    2003-01-01

    The secretory factor VEGF-C has been directly implicated in various physiological processes during embryogenesis and human cancers. However, the importance of the conversion of its precursor proVEGF-C to mature VEGF-C in tumorigenesis, and vessel formation and the identity of the protease(s) that regulate these processes is/are not known. The intracellular processing of proVEGF-C that occurs within the dibasic motif HSIIRR227SL suggests the involvement of the proprotein convertases (PCs) in this process. In addition, furin and VEGF-C were found to be coordinately expressed in adult mouse tissues. Cotransfection of the furin-deficient colon carcinoma cell line LoVo with proVEGF-C and different PC members revealed that furin, PC5, and PC7 are candidate VEGF-C convertases. This finding is consistent with the in vitro digestions of an internally quenched synthetic fluorogenic peptide mimicking the cleavage site of proVEGF-C (220Q-VHSIIRR↓SLP230). The processing of proVEGF-C is blocked by the inhibitory prosegments of furin, PC5, and PACE4, as well as by furin-motif variants of α2-macroglobulin and α1-antitrypsin. Subcutaneous injection of CHO cells stably expressing VEGF-C into nude mice enhanced angiogenesis and lymphangiogenesis, but not tumor growth. In contrast, expression of proVEGF-C obtained following mutation of the cleavage site (HSIIRR227SL to HSIISS227SL) inhibits angiogenesis and lymphangiogenesis as well as tumor growth. Our findings demonstrate the processing of proVEGF-C by PCs and highlight the potential use of PC inhibitors as agents for inhibiting malignancies induced by VEGF-C. PMID:12782675

  5. Establishment and characterization of methylmercury-resistant PC12 cell line.

    PubMed Central

    Miura, K; Clarkson, T W; Ikeda, K; Naganuma, A; Imura, N

    1994-01-01

    Methylmercury (MeHg)-resistant sublines of rat pheochromocytoma (PC12) cells were isolated by repeated exposure to stepwise increased concentrations of MeHg. One of the sublines (PC12/TM) showed an 8- to 10-fold increase in resistance to MeHg compared with parent PC12 cells on the basis of the concentration required for 50% inhibition (IC50) of growth. PC12/TM cells accumulated smaller amounts of MeHg than parent PC12 cells. This reduction in MeHg accumulation in PC12/TM cells resulted from slow uptake and rapid efflux. The intracellular glutathione (GSH) level in PC12/TM cells was four times higher than that of PC12 cells. Pretreatment of PC12/TM cells with buthionine sulfoximine, which decreased the GSH level to that of the parent PC12 cells, increased the sensitivity of PC12/TM cells to MeHg. A close correlation between the MeHg accumulation and MeHg sensitivity was found among seven sublines of PC12 cells and parent PC12 cell line. The GSH level in PC12 sublines was also correlated with their sensitivity to MeHg. PMID:7843125

  6. Vacuum Beat Wave Accelerator

    NASA Astrophysics Data System (ADS)

    Moore, C. I.; Hafizi, B.; Ting, A.; Burris, H. R.; Sprangle, P.; Esarey, E.; Ganguly, A.; Hirshfield, J. L.

    1997-11-01

    The Vacuum Beat Wave Accelerator (VBWA) is a particle acceleration scheme which uses the non-linear ponderomotive beating of two different frequency laser beams to accelerate electrons. A proof-of-principle experiment to demonstrate the VBWA is underway at the Naval Research Laboratory (NRL). This experiment will use the beating of a 1054 nm and 527 nm laser pulse from the NRL T-cubed laser to generate the beat wave and a 4.5 MeV RF electron gun as the electron source. Simulation results and the experimental design will be presented. The suitability of using axicon or higher order Gaussian laser beams will also be discussed.

  7. Ion beam accelerator system

    NASA Technical Reports Server (NTRS)

    Aston, Graeme (Inventor)

    1984-01-01

    A system is described that combines geometrical and electrostatic focusing to provide high ion extraction efficiency and good focusing of an accelerated ion beam. The apparatus includes a pair of curved extraction grids (16, 18) with multiple pairs of aligned holes positioned to direct a group of beamlets (20) along converging paths. The extraction grids are closely spaced and maintained at a moderate potential to efficiently extract beamlets of ions and allow them to combine into a single beam (14). An accelerator electrode device (22) downstream from the extraction grids, is at a much lower potential than the grids to accelerate the combined beam.

  8. Ion beam accelerator system

    NASA Technical Reports Server (NTRS)

    Aston, G. (Inventor)

    1981-01-01

    A system is described that combines geometrical and electrostatic focusing to provide high ion extraction efficiency and good focusing of an accelerated ion beam. The apparatus includes a pair of curved extraction grids with multiple pairs of aligned holes positioned to direct a group of beamlets along converging paths. The extraction grids are closely spaced and maintained at a moderate potential to efficiently extract beamlets of ions and allow them to combine into a single beam. An accelerator electrode device downstream from the extraction grids is at a much lower potential than the grids to accelerate the combined beam. The application of the system to ion implantation is mentioned.

  9. Surfatron accelerator in the local interstellar cloud

    NASA Astrophysics Data System (ADS)

    Loznikov, V. M.; Erokhin, N. S.; Zol'nikova, N. N.; Mikhailovskaya, L. A.

    2017-01-01

    Taking into account results of numerous experiments, the variability of the energy spectra of cosmic rays (protons and helium nuclei) in the energy range of 10 GeV to 107 GeV is explained on the basis of a hypothesis of the existence of two variable sources close to the Sun. The first (soft) surfatron source (with a size of 100 AU) is located at the periphery of the heliosphere. The second (hard) surfatron source (with a size of 1 pc) is situated in the Local Interstellar Cloud (LIC) at a distance of <1 pc. The constant background is described by a power-law spectrum with a slope of 2.75. The variable heliospheric surfatron source is described by a power-law spectrum with a variable amplitude, slope, and cutoff energy, the maximum cutoff energy being in the range of E CH/ Z < 1000 GeV. The variable surfatron source in the LIC is described by a power-law spectrum with a variable amplitude, slope, and cut-off energy, the maximum cut-off energy being E CL/ Z ≤ 3 × 106 GeV. The proposed model is used to approximate data from several experiments performed at close times. The energy of each cosmic-ray component is calculated. The possibility of surfatron acceleration of Fe nuclei ( Z = 26) in the LIC up to an energy of E CL 1017 eV and electron and positrons to the "knee" in the energy spectrum is predicted. By numerically solving a system of nonlinear equations describing the interaction between an electromagnetic wave and a charged particle with an energy of up to E/ Z 3 × 106 GeV, the possibility of trapping, confinement, and acceleration of charged cosmic-ray particles by a quasi-longitudinal plasma wave is demonstrated.

  10. CLASHING BEAM PARTICLE ACCELERATOR

    DOEpatents

    Burleigh, R.J.

    1961-04-11

    A charged-particle accelerator of the proton synchrotron class having means for simultaneously accelerating two separate contra-rotating particle beams within a single annular magnet structure is reported. The magnet provides two concentric circular field regions of opposite magnetic polarity with one field region being of slightly less diameter than the other. The accelerator includes a deflector means straddling the two particle orbits and acting to collide the two particle beams after each has been accelerated to a desired energy. The deflector has the further property of returning particles which do not undergo collision to the regular orbits whereby the particles recirculate with the possibility of colliding upon subsequent passages through the deflector.

  11. Vibration control in accelerators

    SciTech Connect

    Montag, C.

    2011-01-01

    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  12. Dielectric assist accelerating structure

    NASA Astrophysics Data System (ADS)

    Satoh, D.; Yoshida, M.; Hayashizaki, N.

    2016-01-01

    A higher-order TM02 n mode accelerating structure is proposed based on a novel concept of dielectric loaded rf cavities. This accelerating structure consists of ultralow-loss dielectric cylinders and disks with irises which are periodically arranged in a metallic enclosure. Unlike conventional dielectric loaded accelerating structures, most of the rf power is stored in the vacuum space near the beam axis, leading to a significant reduction of the wall loss, much lower than that of conventional normal-conducting linac structures. This allows us to realize an extremely high quality factor and a very high shunt impedance at room temperature. A simulation of a 5 cell prototype design with an existing alumina ceramic indicates an unloaded quality factor of the accelerating mode over 120 000 and a shunt impedance exceeding 650 M Ω /m at room temperature.

  13. Wake field acceleration experiments

    SciTech Connect

    Simpson, J.D.

    1988-01-01

    Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics. I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs.

  14. Accelerator on a Chip

    SciTech Connect

    England, Joel

    2014-06-30

    SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

  15. Charged particle accelerator grating

    DOEpatents

    Palmer, R.B.

    1985-09-09

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams onto the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  16. HEAVY ION LINEAR ACCELERATOR

    DOEpatents

    Van Atta, C.M.; Beringer, R.; Smith, L.

    1959-01-01

    A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

  17. Principles of Induction Accelerators

    NASA Astrophysics Data System (ADS)

    Briggs*, Richard J.

    The basic concepts involved in induction accelerators are introduced in this chapter. The objective is to provide a foundation for the more detailed coverage of key technology elements and specific applications in the following chapters. A wide variety of induction accelerators are discussed in the following chapters, from the high current linear electron accelerator configurations that have been the main focus of the original developments, to circular configurations like the ion synchrotrons that are the subject of more recent research. The main focus in the present chapter is on the induction module containing the magnetic core that plays the role of a transformer in coupling the pulsed power from the modulator to the charged particle beam. This is the essential common element in all these induction accelerators, and an understanding of the basic processes involved in its operation is the main objective of this chapter. (See [1] for a useful and complementary presentation of the basic principles in induction linacs.)

  18. Accelerator on a Chip

    ScienceCinema

    England, Joel

    2016-07-12

    SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

  19. DIELECTRIC WALL ACCELERATOR TECHNOLOGY

    SciTech Connect

    Sampayan, S; Caporaso, G; Chen, Y; Harris, J; Hawkins, S; Holmes, C; Nelson, S; Poole, B; Rhodes, M; Sanders, D; Sullivan, J; Wang, L; Watson, J

    2007-10-18

    The dielectric wall accelerator (DWA) is a compact pulsed power device where the pulse forming lines, switching, and vacuum wall are integrated into a single compact geometry. For this effort, we initiated a extensive compact pulsed power development program and have pursued the study of switching (gas, oil, laser induced surface flashover and photoconductive), dielectrics (ceramics and nanoparticle composites), pulse forming line topologies (asymmetric and symmetric Blumleins and zero integral pulse forming lines), and multilayered vacuum insulator (HGI) technology. Finally, we fabricated an accelerator cell for test on ETAII (a 5.5 MeV, 2 kA, 70 ns pulsewidth electron beam accelerator). We review our past results and report on the progress of accelerator cell testing.

  20. Utilization of the equipment and program cine- and telerecording complex for the high-frequency steel pipe welding investigation

    NASA Astrophysics Data System (ADS)

    Konovalov, Nikolai A.; Veselovsky, Vladimir B.; Furmanov, Valeri B.; Kovalenko, Vladimir I.; Lakhno, Nikolay I.; Kovika, Nikolai D.; Novikov, Leonid V.; Scherbina, Vadim N.; Zlydennaya, Lyubov M.

    1995-08-01

    With the aim of technological process automatization and control for high-frequency welding of different diameter pipes, the machine-program complex (APC) was designed. APC gives the opportunity to create the cine- and telerecording of process in production conditions at the mill '159-529' of the Novomoskovsky Tube Rolling Mill, Ukraine). With the help of APC in real functioning mill conditions, the character of flashing zone length changing and the angle of convergence depending on pipe welding speed was investigated. Also the zone of jumpers is defined. The comparison of theoretical and experimental data gave an opportunity to define a welding rate which is optimal for the most qualitative values of welded joints in the range of pipe products of mill '159-529'.

  1. Amps particle accelerator definition study

    NASA Technical Reports Server (NTRS)

    Sellen, J. M., Jr.

    1975-01-01

    The Particle Accelerator System of the AMPS (Atmospheric, Magnetospheric, and Plasmas in Space) payload is a series of charged particle accelerators to be flown with the Space Transportation System Shuttle on Spacelab missions. In the configuration presented, the total particle accelerator system consists of an energetic electron beam, an energetic ion accelerator, and both low voltage and high voltage plasma acceleration devices. The Orbiter is illustrated with such a particle accelerator system.

  2. An initial study on the estimation of time-varying volumetric treatment images and 3D tumor localization from single MV cine EPID images

    SciTech Connect

    Mishra, Pankaj Mak, Raymond H.; Rottmann, Joerg; Bryant, Jonathan H.; Williams, Christopher L.; Berbeco, Ross I.; Lewis, John H.; Li, Ruijiang

    2014-08-15

    Purpose: In this work the authors develop and investigate the feasibility of a method to estimate time-varying volumetric images from individual MV cine electronic portal image device (EPID) images. Methods: The authors adopt a two-step approach to time-varying volumetric image estimation from a single cine EPID image. In the first step, a patient-specific motion model is constructed from 4DCT. In the second step, parameters in the motion model are tuned according to the information in the EPID image. The patient-specific motion model is based on a compact representation of lung motion represented in displacement vector fields (DVFs). DVFs are calculated through deformable image registration (DIR) of a reference 4DCT phase image (typically peak-exhale) to a set of 4DCT images corresponding to different phases of a breathing cycle. The salient characteristics in the DVFs are captured in a compact representation through principal component analysis (PCA). PCA decouples the spatial and temporal components of the DVFs. Spatial information is represented in eigenvectors and the temporal information is represented by eigen-coefficients. To generate a new volumetric image, the eigen-coefficients are updated via cost function optimization based on digitally reconstructed radiographs and projection images. The updated eigen-coefficients are then multiplied with the eigenvectors to obtain updated DVFs that, in turn, give the volumetric image corresponding to the cine EPID image. Results: The algorithm was tested on (1) Eight digital eXtended CArdiac-Torso phantom datasets based on different irregular patient breathing patterns and (2) patient cine EPID images acquired during SBRT treatments. The root-mean-squared tumor localization error is (0.73 ± 0.63 mm) for the XCAT data and (0.90 ± 0.65 mm) for the patient data. Conclusions: The authors introduced a novel method of estimating volumetric time-varying images from single cine EPID images and a PCA-based lung motion model

  3. Flexible missile autopilot design studies with PC-MATLAB/386

    NASA Technical Reports Server (NTRS)

    Ruth, Michael J.

    1989-01-01

    Development of a responsive, high-bandwidth missile autopilot for airframes which have structural modes of unusually low frequency presents a challenging design task. Such systems are viable candidates for modern, state-space control design methods. The PC-MATLAB interactive software package provides an environment well-suited to the development of candidate linear control laws for flexible missile autopilots. The strengths of MATLAB include: (1) exceptionally high speed (MATLAB's version for 80386-based PC's offers benchmarks approaching minicomputer and mainframe performance); (2) ability to handle large design models of several hundred degrees of freedom, if necessary; and (3) broad extensibility through user-defined functions. To characterize MATLAB capabilities, a simplified design example is presented. This involves interactive definition of an observer-based state-space compensator for a flexible missile autopilot design task. MATLAB capabilities and limitations, in the context of this design task, are then summarized.

  4. Intraocular pressure following ECCE, phacoemulsification, and PC-IOL implantation.

    PubMed

    Kooner, K S; Cooksey, J C; Perry, P; Zimmerman, T J

    1988-09-01

    Abnormal intraocular pressure (IOP), either transient or permanent, may follow extracapsular cataract extraction (ECCE) with phacoemulsification (PE) and posterior chamber intraocular lens (PC-IOL) implantation. We retrospectively studied IOP measurements at different intervals post ECCE and PE in 242 eyes of 211 patients: 105 males, 106 females, 198 Caucasians and 13 blacks. Elevated IOP (greater than 23 mm Hg) was observed in 20 eyes (8.2%). Only two patients (0.8%) had persistent (greater than 3 months) IOP elevation and needed antiglaucoma therapy. Six more eyes (2.5%), however, developed glaucoma after 1 year. Hence, the incidence of secondary pseudophakic glaucoma at the conclusion of this study was 3.3%. No patient required laser or other mechanical surgery for IOP control. ECCE and PE with PC-IOL does not appear to adversely affect IOP. Patients, however, must be followed closely, as some may develop glaucoma months after surgery.

  5. Implementation of WASP-III on an IBM PC

    SciTech Connect

    Buehring, W.A.; Huber, C.C.; Hamilton, B.P.

    1985-01-01

    Argonne National Laboratory (ANL) is currently developing a microcomputer-based energy planning package entitled ENergy and Power Evaluation Program (ENPEP). As presently constructed, ENPEP consists of six analytic modules that can be run sequentially or independently: (1) macroeconomic analysis, (2) energy demand forecasting, (3) integrated energy demand/supply analysis, (4) electric load forecasting, (5) expansion planning for electrical generating systems, and (6) impacts of alternative supply systems. The Wien Automatic System Planning Package (WASP-III) is the fifth module of ENPEP and forms the heart of the ENPEP analytic capability. The experience in converting WASP-III to the IBM PC is reviewed and some recommendations for good performance on the PC are given. Finally, a few suggestions are presented for WASP improvements from the point of view of the user of the personal computer version of WASP.

  6. Magnetospheric filter effect for Pc 3 Alfven mode waves

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Comfort, R. H.; Gallagher, D. L.; Green, J. L.; Musielak, Z. E.; Moore, T. E.

    1995-01-01

    We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the O(+) concentration is removed from the plasma composition, the barriers caused by the O(+) no longer exist, and waves with much higher frequencies than 30 mHz can penetrate to low altitudes. The result that the 30 mHz or lower frequency Alfven waves can be guided to low altitudes agrees with ground-based power spectrum observation at high altitudes.

  7. Magnetospheric filter effect for Pc 3 Alfven mode waves

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Comfort, R. H.; Gallagher, D. L.; Green, J. L.; Musielak, Z. E.; Moore, T. E.

    1994-01-01

    We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of a magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the O(+) concentration is removed from the plasma composition, the barriers caused by the O(+) no longer exist, and waves with much higher frequencies than 30 mHz can penetrate to low altitudes. The result that the 30 mHz or lower frequency Alfven waves can be guided to low altitudes agrees with ground-based power spectrum observations at high latitudes.

  8. Structure of pentaquarks Pc+ in the chiral quark model

    NASA Astrophysics Data System (ADS)

    Yang, Gang; Ping, Jialun; Wang, Fan

    2017-01-01

    The recent experimental results of the LHCb Collaboration suggested the existence of pentaquark states with a charmonium. To understand the structure of the states, a dynamical calculation of 5-quark systems with quantum numbers I JP=1/2 (1/2 )±,1/2 (3/2 )±and1/2 (5/2 )±is performed in the framework of the chiral quark model with the help of the Gaussian expansion method. The results show that there are several negative parity resonance states while all of the positive parity states are the scattering states. The Pc(4380 ) state is suggested to be the pentaquark state of Σc*D ¯. Although the energy of ΣcD ¯* is very close to the mass of Pc(4450 ), the inconsistent parity prevents the assignment. The calculated distances between quarks confirm the molecular nature of the states.

  9. Dystrophin Dp71 in PC12 cell adhesion

    PubMed Central

    Enríquez-Aragón, Jose Arturo; Cerna-Cortés, Joel; Bermúdez de León, Mario; García-Sierra, Francisco; González, Everardo; Mornet, Dominique; Cisneros, Bulmaro

    2005-01-01

    Previously, we reported that PC12 cells with decreased Dp71 expression (antisense-Dp71 cells) display deficient nerve-growth-factor-induced neurite outgrowth. In this study, we show that disturbed neurite outgrowth of antisense-Dp71 cells is accompanied by decreased adhesion activity on laminin, collagen and fibronectin. In wild-type cells, the immunostaining of Dp71 and _1-integrin overlaps in the basal area contacting the substrate, but staining of both proteins decrease in the antisense-Dp71 cells. Morphology of antisense-Dp71 cells at the electron microscopic level is characterized by the lack of filopodia, cellular projections involved in adhesion. Our findings suggest that Dp71 is required for the efficient PC12 cell attachment to b1-integrin-dependent substrata and that decreased adhesion activity of the anti-sense-Dp71 cells could determine their deficiency to extend neurites. PMID:15706226

  10. Tablet PC Enabled Body Sensor System for Rural Telehealth Applications

    PubMed Central

    Panicker, Nitha V.; Kumar, A. Sukesh

    2016-01-01

    Telehealth systems benefit from the rapid growth of mobile communication technology for measuring physiological signals. Development and validation of a tablet PC enabled noninvasive body sensor system for rural telehealth application are discussed in this paper. This system includes real time continuous collection of physiological parameters (blood pressure, pulse rate, and temperature) and fall detection of a patient with the help of a body sensor unit and wireless transmission of the acquired information to a tablet PC handled by the medical staff in a Primary Health Center (PHC). Abnormal conditions are automatically identified and alert messages are given to the medical officer in real time. Clinical validation is performed in a real environment and found to be successful. Bland-Altman analysis is carried out to validate the wrist blood pressure sensor used. The system works well for all measurements. PMID:26884757

  11. Designing reliability into accelerators

    NASA Astrophysics Data System (ADS)

    Hutton, A.

    1992-07-01

    Future accelerators will have to provide a high degree of reliability. Quality must be designed in right from the beginning and must remain a central theme throughout the project. The problem is similar to the problems facing US industry today, and examples of the successful application of quality engineering will be given. Different aspects of an accelerator project will be addressed: Concept, Design, Motivation, Management Techniques, and Fault Diagnosis. The importance of creating and maintaining a coherent team will be stressed.

  12. Microgravity Acceleration Measurement System

    NASA Technical Reports Server (NTRS)

    Foster, William

    2009-01-01

    Microgravity Acceleration Measurement System (MAMS) is an ongoing study of the small forces (vibrations and accelerations) on the ISS that result from the operation of hardware, crew activities, as well as dockings and maneuvering. Results will be used to generalize the types of vibrations affecting vibration-sensitive experiments. Investigators seek to better understand the vibration environment on the space station to enable future research.

  13. CEBAF Accelerator Achievements

    NASA Astrophysics Data System (ADS)

    Chao, Y. C.; Drury, M.; Hovater, C.; Hutton, A.; Krafft, G. A.; Poelker, M.; Reece, C.; Tiefenback, M.

    2011-05-01

    In the past decade, nuclear physics users of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) have benefited from accelerator physics advances and machine improvements. As of early 2011, CEBAF operates routinely at 6 GeV, with a 12 GeV upgrade underway. This article reports highlights of CEBAF's scientific and technological evolution in the areas of cryomodule refurbishment, RF control, polarized source development, beam transport for parity experiments, magnets and hysteresis handling, beam breakup, and helium refrigerator operational optimization.

  14. 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.

  15. Rolamite acceleration sensor

    DOEpatents

    Abbin, Joseph P.; Briner, Clifton F.; Martin, Samuel B.

    1993-01-01

    A rolamite acceleration sensor which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently.

  16. Rolamite acceleration sensor

    DOEpatents

    Abbin, J.P.; Briner, C.F.; Martin, S.B.

    1993-12-21

    A rolamite acceleration sensor is described which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently. 6 figures.

  17. Collective field accelerator

    DOEpatents

    Luce, John S.

    1978-01-01

    A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a .nu./.gamma. of .about. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam.

  18. Estimation of cardiac motion in cine-MRI sequences by correlation transform optical flow of monogenic features distance

    NASA Astrophysics Data System (ADS)

    Gao, Bin; Liu, Wanyu; Wang, Liang; Liu, Zhengjun; Croisille, Pierre; Delachartre, Philippe; Clarysse, Patrick

    2016-12-01

    Cine-MRI is widely used for the analysis of cardiac function in clinical routine, because of its high soft tissue contrast and relatively short acquisition time in comparison with other cardiac MRI techniques. The gray level distribution in cardiac cine-MRI is relatively homogenous within the myocardium, and can therefore make motion quantification difficult. To ensure that the motion estimation problem is well posed, more image features have to be considered. This work is inspired by a method previously developed for color image processing. The monogenic signal provides a framework to estimate the local phase, orientation, and amplitude, of an image, three features which locally characterize the 2D intensity profile. The independent monogenic features are combined into a 3D matrix for motion estimation. To improve motion estimation accuracy, we chose the zero-mean normalized cross-correlation as a matching measure, and implemented a bilateral filter for denoising and edge-preservation. The monogenic features distance is used in lieu of the color space distance in the bilateral filter. Results obtained from four realistic simulated sequences outperformed two other state of the art methods even in the presence of noise. The motion estimation errors (end point error) using our proposed method were reduced by about 20% in comparison with those obtained by the other tested methods. The new methodology was evaluated on four clinical sequences from patients presenting with cardiac motion dysfunctions and one healthy volunteer. The derived strain fields were analyzed favorably in their ability to identify myocardial regions with impaired motion.

  19. TH-E-17A-07: Improved Cine Four-Dimensional Computed Tomography (4D CT) Acquisition and Processing Method

    SciTech Connect

    Castillo, S; Castillo, R; Castillo, E; Pan, T; Ibbott, G; Balter, P; Hobbs, B; Dai, J; Guerrero, T

    2014-06-15

    Purpose: Artifacts arising from the 4D CT acquisition and post-processing methods add systematic uncertainty to the treatment planning process. We propose an alternate cine 4D CT acquisition and post-processing method to consistently reduce artifacts, and explore patient parameters indicative of image quality. Methods: In an IRB-approved protocol, 18 patients with primary thoracic malignancies received a standard cine 4D CT acquisition followed by an oversampling 4D CT that doubled the number of images acquired. A second cohort of 10 patients received the clinical 4D CT plus 3 oversampling scans for intra-fraction reproducibility. The clinical acquisitions were processed by the standard phase sorting method. The oversampling acquisitions were processed using Dijkstras algorithm to optimize an artifact metric over available image data. Image quality was evaluated with a one-way mixed ANOVA model using a correlation-based artifact metric calculated from the final 4D CT image sets. Spearman correlations and a linear mixed model tested the association between breathing parameters, patient characteristics, and image quality. Results: The oversampling 4D CT scans reduced artifact presence significantly by 27% and 28%, for the first cohort and second cohort respectively. From cohort 2, the inter-replicate deviation for the oversampling method was within approximately 13% of the cross scan average at the 0.05 significance level. Artifact presence for both clinical and oversampling methods was significantly correlated with breathing period (ρ=0.407, p-value<0.032 clinical, ρ=0.296, p-value<0.041 oversampling). Artifact presence in the oversampling method was significantly correlated with amount of data acquired, (ρ=-0.335, p-value<0.02) indicating decreased artifact presence with increased breathing cycles per scan location. Conclusion: The 4D CT oversampling acquisition with optimized sorting reduced artifact presence significantly and reproducibly compared to the phase

  20. Assessment of ventricular coupling with real-time cine MRI and its value to differentiate constrictive pericarditis from restrictive cardiomyopathy.

    PubMed

    Francone, Marco; Dymarkowski, Steven; Kalantzi, Maria; Rademakers, Frank E; Bogaert, Jan

    2006-04-01

    The purpose of this study was to evaluate the use of respiratory-related ventricular coupling to differentiate patients with constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM). In 18 histologically proven cases of CP, 6 patients with inflammatory pericarditis (IP), 15 RCM patients and 17 normal subjects, real-time cine MRI was performed in the cardiac short-axis (basal half of the ventricles) during operator-guided deep respiration. The images were analyzed for ventricular septal position and shape during early ventricular filling. Early diastolic septal inversion (I) or flattening (F) was found in all CP (I:15,F:3), and in all IP (I:2,F:4), but seldom in normals (F:1) and not in RCM. The septal abnormalities occurred at the onset of inspiration and rapidly disappeared with the next heartbeats. The amount of ventricular coupling was evaluated by quantifying the difference in the maximal septal excursion between inspiration and expiration. This parameter, normalized to the biventricular diameter, was significantly larger in CP (20.0+/-4.5%, P<0.0001) and IP (14.8+/-3.2%, P<0.0001) patients than in normals (7.0+/-2.4%), whereas RCM patients had a trend toward decreased excursion (4.2+/-1.7%, P=0.11). A cut-off value of 11.8% (mean normals +2 SD) enabled to differentiate CP patients from normals and RCM patients completely. Real-time cine MRI can easily depict increased ventricular coupling, which may be helpful to better differentiate between CP and RCM patients, especially in patients with normal or minimally thickened pericardium. The increase in coupling in IP patients is likely caused by decreased compliance of the inflamed pericardial layers.

  1. Characterization of three dimensional volumetric strain distribution during passive tension of the human tibialis anterior using Cine Phase Contrast MRI.

    PubMed

    Jensen, Elisabeth R; Morrow, Duane A; Felmlee, Joel P; Murthy, Naveen S; Kaufman, Kenton R

    2016-10-03

    Intramuscular pressure correlates strongly with muscle tension and is a promising tool for quantifying individual muscle force. However, clinical application is impeded by measurement variability that is not fully understood. Previous studies point to regional differences in IMP, specifically increasing pressure with muscle depth. Based on conservation of mass, intramuscular pressure and volumetric strain distributions may be inversely related. Therefore, we hypothesized volumetric strain would decrease with muscle depth. To test this we quantified 3D volumetric strain in the tibialis anterior of 12 healthy subjects using Cine Phase Contrast Magnetic Resonance Imaging. Cine Phase Contrast data were collected while a custom apparatus rotated the subjects' ankle continuously between neutral and plantarflexion. A T2-weighted image stack was used to define the resting tibials anterior position. Custom and commercial post-processing software were used to quantify the volumetric strain distribution. To characterize regional strain changes, the muscle was divided into superior-inferior sections and either medial-lateral or anterior-posterior slices. Mean volumetric strain was compared across the sections and slices. As hypothesized, volumetric strain demonstrated regional differences with a decreasing trend from the anterior (superficial) to the posterior (deep) muscle regions. Statistical tests showed significant main effects and interactions of superior-inferior and anterior-posterior position as well as superior-inferior and medial-lateral position on regional strain. These data support our hypothesis and imply a potential relationship between regional volumetric strain and intramuscular pressure. This finding may advance our understanding of intramuscular pressure variability sources and lead to more reliable measurement solutions in the future.

  2. Functional measurements based on feature tracking of cine magnetic resonance images identify left ventricular segments with myocardial scar

    PubMed Central

    2009-01-01

    Background The aim of the study was to perform a feature tracking analysis on cine magnetic resonance (MR) images to elucidate if functional measurements of the motion of the left ventricular wall may detect scar defined with gadolinium enhanced MR. Myocardial contraction can be measured in terms of the velocity, displacement and local deformation (strain) of a particular myocardial segment. Contraction of the myocardial wall will be reduced in the presence of scar and as a consequence of reduced myocardial blood flow. Methods Thirty patients (3 women and 27 men) were selected based on the presence or absence of extensive scar in the anteroseptal area of the left ventricle. The patients were investigated in stable clinical condition, 4-8 weeks post ST-elevation myocardial infarction treated with percutaneous coronary intervention. Seventeen had a scar area >75% in at least one anteroseptal segment (scar) and thirteen had scar area <1% (non-scar). Velocity, displacement and strain were calculated in the longitudinal direction, tangential to the endocardial outline, and in the radial direction, perpendicular to the tangent. Results In the scar patients, segments with scar showed lower functional measurements than remote segments. Radial measurements of velocity, displacement and strain performed better in terms of receiver-operator-characteristic curves (ROC) than the corresponding longitudinal measurements. The best area-under-curve was for radial strain, 0.89, where a cut-off value of 38.8% had 80% sensitivity and 86% specificity for the detection of a segment with scar area >50%. As a percentage of the mean, intraobserver variability was 16-14-26% for radial measurements of displacement-velocity-strain and corresponding interobserver variability was 13-12-18%. Conclusion Feature tracking analysis of cine-MR displays velocity, displacement and strain in the radial and longitudinal direction and may be used for the detection of transmural scar. The accuracy and

  3. Practical Pocket PC Application w/Biometric Security

    NASA Technical Reports Server (NTRS)

    Logan, Julian

    2004-01-01

    I work in the Flight Software Engineering Branch, where we provide design and development of embedded real-time software applications for flight and supporting ground systems to support the NASA Aeronautics and Space Programs. In addition, this branch evaluates, develops and implements new technologies for embedded real-time systems, and maintains a laboratory for applications of embedded technology. The majority of microchips that are used in modern society have been programmed using embedded technology. These small chips can be found in microwaves, calculators, home security systems, cell phones and more. My assignment this summer entails working with an iPAQ HP 5500 Pocket PC. This top-of-the-line hand-held device is one of the first mobile PC's to introduce biometric security capabilities. Biometric security, in this case a fingerprint authentication system, is on the edge of technology as far as securing information. The benefits of fingerprint authentication are enormous. The most significant of them are that it is extremely difficult to reproduce someone else's fingerprint, and it is equally difficult to lose or forget your own fingerprint as opposed to a password or pin number. One of my goals for this summer is to integrate this technology with another Pocket PC application. The second task for the summer is to develop a simple application that provides an Astronaut EVA (Extravehicular Activity) Log Book capability. The Astronaut EVA Log Book is what an astronaut would use to report the status of field missions, crew physical health, successes, future plans, etc. My goal is to develop a user interface into which these data fields can be entered and stored. The applications that I am developing are created using eMbedded Visual C++ 4.0 with the Pocket PC 2003 Software Development Kit provided by Microsoft.

  4. The PC Dugout Micro-Mainframe Integration System: PAX Implementation

    DTIC Science & Technology

    1991-05-01

    System Mainframe Implementation Language PC Implementation Language Communications Package and File Transfer Protocol Requirements 5 DUGOUT DESIGN...remember any commands or language syntax. In some cases users are asked to answer a few simple, nontechnical prompts. To download or upload files, a...problem. The database management systems Focus and Structured Query Language /Data System (SQL/DS) successfully circumvent this restriction in the PAX VM/CMS

  5. Falling PC Solitaire Cards: An Open-Inquiry Approach

    ERIC Educational Resources Information Center

    Gonzalez-Espada, Wilson J.

    2012-01-01

    Many of us have played the PC Solitaire game that comes as standard software in many computers. Although I am not a great player, occasionally I win a game or two. The game celebrates my accomplishment by pushing the cards forward, one at a time, falling gracefully in what appears to look like a parabolic path in a drag-free environment. One day,…

  6. The photodynamic antibacterial effects of silicon phthalocyanine (Pc) 4.

    PubMed

    Dimaano, Matthew L; Rozario, Chantal; Nerandzic, Michelle M; Donskey, Curtis J; Lam, Minh; Baron, Elma D

    2015-04-08

    The emergence of antibiotic-resistant strains in facultative anaerobic Gram-positive coccal bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), is a global health issue. Typically, MRSA strains are found associated with institutions like hospitals but recent data suggest that they are becoming more prevalent in community-acquired infections. It is thought that the incidence and prevalence of bacterial infections will continue to increase as (a) more frequent use of broad-spectrum antibiotics and immunosuppressive medications; (b) increased number of invasive medical procedures; and (c) higher incidence of neutropenia and HIV infections. Therefore, more optimal treatments, such as photodynamic therapy (PDT), are warranted. PDT requires the interaction of light, a photosensitizing agent, and molecular oxygen to induce cytotoxic effects. In this study, we investigated the efficacy and characterized the mechanism of cytotoxicity induced by photodynamic therapy sensitized by silicon phthalocyanine (Pc) 4 on (a) methicillin-sensitive Staphylococcus aureus (MSSA) (ATCC 25923); (b) community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) (ATCC 43300); and (c) hospital acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) (PFGE type 300). Our data include confocal image analysis, which confirmed that Pc 4 is taken up by all S. aureus strains, and viable cell recovery assay, which showed that concentrations as low as 1.0 μM Pc 4 incubated for 3 h at 37 °C followed by light at 2.0 J/cm2 can reduce cell survival by 2-5 logs. These results are encouraging, but before PDT can be utilized as an alternative treatment for eradicating resistant strains, we must first characterize the mechanism of cell death that Pc 4-based PDT employs in eliminating these pathogens.

  7. The Photodynamic Antibacterial Effects of Silicon Phthalocyanine (Pc) 4

    PubMed Central

    Dimaano, Matthew L.; Rozario, Chantal; Nerandzic, Michelle M.; Donskey, Curtis J.; Lam, Minh; Baron, Elma D.

    2015-01-01

    The emergence of antibiotic-resistant strains in facultative anaerobic Gram-positive coccal bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), is a global health issue. Typically, MRSA strains are found associated with institutions like hospitals but recent data suggest that they are becoming more prevalent in community-acquired infections. It is thought that the incidence and prevalence of bacterial infections will continue to increase as (a) more frequent use of broad-spectrum antibiotics and immunosuppressive medications; (b) increased number of invasive medical procedures; and (c) higher incidence of neutropenia and HIV infections. Therefore, more optimal treatments, such as photodynamic therapy (PDT), are warranted. PDT requires the interaction of light, a photosensitizing agent, and molecular oxygen to induce cytotoxic effects. In this study, we investigated the efficacy and characterized the mechanism of cytotoxicity induced by photodynamic therapy sensitized by silicon phthalocyanine (Pc) 4 on (a) methicillin-sensitive Staphylococcus aureus (MSSA) (ATCC 25923); (b) community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) (ATCC 43300); and (c) hospital acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) (PFGE type 300). Our data include confocal image analysis, which confirmed that Pc 4 is taken up by all S. aureus strains, and viable cell recovery assay, which showed that concentrations as low as 1.0 μM Pc 4 incubated for 3 h at 37 °C followed by light at 2.0 J/cm2 can reduce cell survival by 2–5 logs. These results are encouraging, but before PDT can be utilized as an alternative treatment for eradicating resistant strains, we must first characterize the mechanism of cell death that Pc 4-based PDT employs in eliminating these pathogens. PMID:25856680

  8. Accelerators for America's Future

    NASA Astrophysics Data System (ADS)

    Bai, Mei

    2016-03-01

    Particle accelerator, a powerful tool to energize beams of charged particles to a desired speed and energy, has been the working horse for investigating the fundamental structure of matter and fundermental laws of nature. Most known examples are the 2-mile long Stanford Linear Accelerator at SLAC, the high energy proton and anti-proton collider Tevatron at FermiLab, and Large Hadron Collider that is currently under operation at CERN. During the less than a century development of accelerator science and technology that led to a dazzling list of discoveries, particle accelerators have also found various applications beyond particle and nuclear physics research, and become an indispensible part of the economy. Today, one can find a particle accelerator at almost every corner of our lives, ranging from the x-ray machine at the airport security to radiation diagnostic and therapy in hospitals. This presentation will give a brief introduction of the applications of this powerful tool in fundermental research as well as in industry. Challenges in accelerator science and technology will also be briefly presented

  9. Biomedical accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Freeman, Stewart P. H. T.; Vogel, John S.

    1995-05-01

    Ultrasensitive SIMS with accelerator based spectrometers has recently begun to be applied to biomedical problems. Certain very long-lived radioisotopes of very low natural abundances can be used to trace metabolism at environmental dose levels ( [greater-or-equal, slanted] z mol in mg samples). 14C in particular can be employed to label a myriad of compounds. Competing technologies typically require super environmental doses that can perturb the system under investigation, followed by uncertain extrapolation to the low dose regime. 41Ca and 26Al are also used as elemental tracers. Given the sensitivity of the accelerator method, care must be taken to avoid contamination of the mass spectrometer and the apparatus employed in prior sample handling including chemical separation. This infant field comprises the efforts of a dozen accelerator laboratories. The Center for Accelerator Mass Spectrometry has been particularly active. In addition to collaborating with groups further afield, we are researching the kinematics and binding of genotoxins in-house, and we support innovative uses of our capability in the disciplines of chemistry, pharmacology, nutrition and physiology within the University of California. The field can be expected to grow further given the numerous potential applications and the efforts of several groups and companies to integrate more the accelerator technology into biomedical research programs; the development of miniaturized accelerator systems and ion sources capable of interfacing to conventional HPLC and GMC, etc. apparatus for complementary chemical analysis is anticipated for biomedical laboratories.

  10. Kinetics of alpha-PcCu --> beta-PcCu isothermal conversion in air and thermal behavior of beta-PcCu from in situ real-time laboratory parallel-beam X-ray powder diffraction.

    PubMed

    Ballirano, Paolo; Caminiti, Ruggero

    2009-07-09

    The kinetics of the alpha-PcCu --> beta-PcCu conversion in air has been followed, under isothermal conditions, in situ real-time in the 423-443 K temperature range. Data have been fitted following the JMAK model. The reaction order of the kinetics at 423 K is consistent with a diffusion controlled, deceleratory nucleation rate process for 2D laminar particles, whereas at higher temperatures it is consistent with a phase boundary controlled, deceleratory nucleation rate process for 2D laminar particles. At 423 K, the overall transformation mechanism implies three steps: growth of the alpha-PcCu phase, disordering of adjacent columns of molecules of phthalocyanine, and nucleation and growth of the beta-PcCu phase. The calculated empirical activation energy is of 187 kJ/mol significantly greater than that for the alpha-PcCo --> beta-PcCo conversion. This fact seems to support the reported different structures of alpha-PcCo and alpha-PcCu. Investigation of the thermal behavior of beta-PcCu indicates a strongly anisotropic thermal expansion that follows the alpha(c) > alpha(a) approximately = alpha(b) trend. Moreover, the beta angle decreases with increasing temperature. Such anisotropy is consistent with the geometry of the very weak N3...H3 hydrogen bond which acts mainly along the c axis.

  11. Design and research of retrofitting PC boiler into CFB boiler

    SciTech Connect

    Chen, H.P.; Lu, J.D.; Huang, L.; Liu, H.; Lin, Z.; Liu, D.C.

    1997-12-31

    In China, there are a large number of aged pulverized coal (PC) boilers at aging utility power plants. Many of them are beyond their reasonable working life or in a condition of unreliable operation, low combustion efficiency, and serious air pollution. It is very important and urgent to retrofit the aged PC boilers, and repower the aging utility power plants in China. Circulating fluidized bed (CFB) boilers have been developed rapidly, and paid great attention to in China. There are many striking advantages to retrofit an aged boiler with a CFB boiler. The retrofitting is suitable to meet the needs of effective utilization of low-grade coal, reducing SO{sub 2} and NO{sub x} emissions and repowering an aging power plant. The cost is much lower than that of building a new CFB unit. The National Laboratory of Coal Combustion (NLCC) has always paid great attention to studying and developing CFB combustion technology in connection with Chinese national conditions, and has evolved distinguishing technology features of its own. This paper introduces a new design concept of retrofitting PC boiler into Pi ({Pi}-shaped) CFB boiler with downward exhaust cyclone, and relevant research work and results of design and calculation.

  12. Electronic transitions and band offsets in C60:SubPc and C60:MgPc on MoO3 studied by modulated surface photovoltage spectroscopy

    NASA Astrophysics Data System (ADS)

    Fengler, S.; Dittrich, Th.; Rusu, M.

    2015-07-01

    Electronic transitions at interfaces between MoO3 layers and organic layers of C60, SubPc, MgPc, and nano-composite layers of SubPc:C60 and MgPc:C60 have been studied by modulated surface photovoltage (SPV) spectroscopy. For all systems, time dependent and modulated SPV signals pointed to dissociation of excitons at the MoO3/organic layer interfaces with a separation of holes towards MoO3. The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps (EHL) of C60, SubPc, and MgPc and the effective EHL of SubPc:C60 and MgPc:C60 were measured. The offsets between the LUMO (ΔEL) or HOMO (ΔEH) bands were obtained with high precision and amounted to 0.33 or 0.73 eV for SubPc:C60, respectively, and to -0.33 or 0.67 eV for MgPc:C60, respectively. Exponential tails below EHL and most pronounced sub-bandgap transitions were characterized and ascribed to disorder and transitions from HOMO bands to unoccupied defect states.

  13. Static and Dynamic Energetic Disorders in the C60, PC61BM, C70, and PC71BM Fullerenes.

    PubMed

    Tummala, Naga Rajesh; Zheng, Zilong; Aziz, Saadullah G; Coropceanu, Veaceslav; Brédas, Jean-Luc

    2015-09-17

    We use a combination of molecular dynamics simulations and density functional theory calculations to investigate the energetic disorder in fullerene systems. We show that the energetic disorder evaluated from an ensemble average contains contributions of both static origin (time-independent, due to loose packing) and dynamic origin (time-dependent, due to electron-vibration interactions). In order to differentiate between these two contributions, we compare the results obtained from an ensemble average approach with those derived from a time average approach. It is found that in both amorphous C60 and C70 bulk systems, the degrees of static and dynamic disorder are comparable, while in the amorphous PC61BM and PC71BM systems, static disorder is about twice as large as dynamic disorder.

  14. An overview of the evaluation plan for PC/MISI: PC-based Multiple Information System Interface

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Lim, Bee Lee; Hall, Philip P.

    1985-01-01

    An initial evaluation plan for the personal computer multiple information system interface (PC/MISI) project is discussed. The document is intend to be used as a blueprint for the evaluation of this system. Each objective of the design project is discussed along with the evaluation parameters and methodology to be used in the evaluation of the implementation's achievement of those objectives. The potential of the system for research activities related to more general aspects of information retrieval is also discussed.

  15. Is the Metallic Phosphorus Carbide (β0-PC) Monolayer Stable? An Answer from a Theoretical Perspective.

    PubMed

    Rajbanshi, Biplab; Sarkar, Pranab

    2017-02-16

    Phosphorus carbide (PC) has been the subject of major research efforts in recent years. In this regard, very recently, a stoichiometric metallic phosphorus carbide (β0-PC) monolayer has been proposed as locally stable with one lone nonbonding electron in each C atom. Therefore, the ambiguity of coexistence of a nonbonding electron with metallic properties for β0-PC is reported and hence deserves further explanation. Herein, using first-principles calculations, we have explored the stability and electronic properties of β0-PC to resolve this ambiguity. The metallic behavior of β0-PC is explained on the basis of electron delocalization involving P and C atoms along a zigzag chain of β0-PC. We have also explored the possibility of getting a β0-PC monolayer via homogeneous doping of C (P) into phosphorene (graphene) and layer exfoliation of 3D bulk PC with β-InS-like structure, which has been experimentally synthesized.

  16. Laser Ion Acceleration Control

    NASA Astrophysics Data System (ADS)

    Kawata, Shigeo; Nagashima, T.; Izumiyama, T.; Sato, D.; Takano, M.; Barada, D.; Ma, Y. Y.; Gu, Y. J.; Kong, Q.; Wang, P. X.; Wang, W. M.

    2013-10-01

    An intense femtosecond pulsed laser is employed to accelerate ions. The issues in the laser ion accelerator include the energy efficiency from the laser to the ions, the ion beam collimation, the ion energy spectrum control, the ion beam bunching, the ion particle energy control, etc. In the study particle computer simulations were performed to solve the issues, and each component was designed to control the ion beam quality. When an intense laser illuminates a target, electrons in the target are accelerated and leave from the target; temporarily a strong electric field is formed between the high-energy electrons and the target ions, and the target ions are accelerated. The energy efficiency from the laser to ions was improved by using a solid target with a fine sub-wavelength structure or by a near critical density gas plasma. The ion beam collimation was realized by holes behind the solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching were successfully realized by a multi-stage laser-target interaction. The present study proposed a novel concept for a future compact laser ion accelerator, based on each component study required to control the ion beam quality and parameters. Partly supported by JSPS, MEXT, CORE, Japan/US Cooperation program, ASHULA and ILE/Osaka University.

  17. Dielectric laser accelerators

    NASA Astrophysics Data System (ADS)

    England, R. Joel; Noble, Robert J.; Bane, Karl; Dowell, David H.; Ng, Cho-Kuen; Spencer, James E.; Tantawi, Sami; Wu, Ziran; Byer, Robert L.; Peralta, Edgar; Soong, Ken; Chang, Chia-Ming; Montazeri, Behnam; Wolf, Stephen J.; Cowan, Benjamin; Dawson, Jay; Gai, Wei; Hommelhoff, Peter; Huang, Yen-Chieh; Jing, Chunguang; McGuinness, Christopher; Palmer, Robert B.; Naranjo, Brian; Rosenzweig, James; Travish, Gil; Mizrahi, Amit; Schachter, Levi; Sears, Christopher; Werner, Gregory R.; Yoder, Rodney B.

    2014-10-01

    The use of infrared lasers to power optical-scale lithographically fabricated particle accelerators is a developing area of research that has garnered increasing interest in recent years. The physics and technology of this approach is reviewed, which is referred to as dielectric laser acceleration (DLA). In the DLA scheme operating at typical laser pulse lengths of 0.1 to 1 ps, the laser damage fluences for robust dielectric materials correspond to peak surface electric fields in the GV /m regime. The corresponding accelerating field enhancement represents a potential reduction in active length of the accelerator between 1 and 2 orders of magnitude. Power sources for DLA-based accelerators (lasers) are less costly than microwave sources (klystrons) for equivalent average power levels due to wider availability and private sector investment. Because of the high laser-to-particle coupling efficiency, required pulse energies are consistent with tabletop microJoule class lasers. Combined with the very high (MHz) repetition rates these lasers can provide, the DLA approach appears promising for a variety of applications, including future high-energy physics colliders, compact light sources, and portable medical scanners and radiative therapy machines.

  18. Electrostatic Plasma Accelerator (EPA)

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Aston, Graeme

    1989-01-01

    The Electrostatic Plasma Accelerator (EPA) is a thruster concept which promises specific impulse levels between low power arcjets and those of the ion engine while retaining the relative simplicity of the arcjet. The EPA thruster produces thrust through the electrostatic acceleration of a moderately dense plasma. No accelerating electrodes are used and the specific impulse is a direct function of the applied discharge voltage and the propellant atomic mass. The goal of the present program is to demonstrate feasibility of the EPA thruster concept through experimental and theoretical investigations of the EPA acceleration mechanism and discharge chamber performance. Experimental investigations will include operating the test bed ion (TBI) engine as an EPA thruster and parametrically varying the thruster geometry and operating conditions to quantify the electrostatic plasma acceleration effect. The theoretical investigations will include the development of a discharge chamber model which describes the relationships between the engine size, plasma properties, and overall performance. For the EPA thruster to be a viable propulsion concept, overall thruster efficiencies approaching 30% with specific impulses approaching 1000 s must be achieved.

  19. 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.

  20. Radiosurgery with a linear accelerator. Methodological aspects.

    PubMed

    Betti, O O; Galmarini, D; Derechinsky, V

    1991-01-01

    Based on the concepts of Leksell and on recommendations of different Swedish physicists on the use of linear accelerator for radiosurgical use, we developed a new methodology coupling the Talairach stereotactic system with a commercial linac. Anatomical facts encouraged us to use coronal angles of irradiation employing the angular displacement of the linac above the horizontal plane. Different coronal planes are obtained by rotation of the stereotactic frame. The center of the irradiated target coincides with the irradiation and rotation center of the linear accelerator. Multiple targets can be irradiated in the same session. We use as recommended a secondary collimator in heavy alloy. Special software was prepared after different dosimetric controls. The use of a PC allows us to employ 1-6 targets and different collimators to displace the isocenters in order to obtain geometrical isodose modification, and to change the value of each irradiation arc or portions of each arc in some minutes. Simple or sophisticated neurosurgical strategies can be applied in the treatment of frequently irregular shape and volume AVMs.

  1. Acceleration of tomographic hyperspectral restoration algorithms

    NASA Astrophysics Data System (ADS)

    Schau, Harvey C.

    2006-05-01

    Hyperspectral imaging spectrometers have proven to be both versatile and powerful instruments with applications in diverse areas such as medical diagnosis, land usage, military target detection, and art forgery. In many applications scanning systems cannot be effectively employed and true "flash" operation is necessary. Multiplex systems have been developed which can gather information in multispectral bands simultaneously, and then produce a datacube after mathematical restoration. Such system enjoy compact size, robust construction, inexpensive costs and zero moving parts at the cost of highly complex mathematical restoration operations. Currently the limiting feature of such tomographic hyperspectral imagers such as the FMDIS [1,2] is the speed of restoration. Due to the large sizes of the restoration kernel, restorations are typically recursive and require many iterations to achieve satisfactory results. Little can be done to make the systems smaller since the size is determined by the number of colors and pixel size of the focal plane arrays (FPA) employed. Thus, techniques must be investigated to speed up the restoration either by reducing the number of iterations or reducing the number of operations within an iteration. It is assumed that little can be done to reduce the number of operations in an iteration since the operations are done in sparse format, we therefore investigate reducing the number of iterations through mathematical accelerations. We assume this acceleration will work to advantage regardless of the mechanism (PC-based or dedicated processor such as a gate array) by which the restoration is implemented.

  2. Characterization of μ-oxo-(BsubPc)2 in Multiple Organic Photovoltaic Device Architectures: Comparing against and Combining with Cl-BsubPc.

    PubMed

    Castrucci, Jeffrey S; Garner, Richard K; Dang, Jeremy D; Thibau, Emmanuel; Lu, Zheng-Hong; Bender, Timothy P

    2016-09-21

    We demonstrate the first application of a unique boron subphthalocyanine (BsubPc) derivative, the oxygen bridged dimer μ-oxo-(BsubPc)2, as a multifunctional material within planar heterojunction organic photovoltaic (OPV) devices. We first explored the pairing of μ-oxo-(BsubPc)2 with well-known electron accepting and electron donating materials to explore its basic functionality. These preliminary device structures and metrics indicated that μ-oxo-(BsubPc)2 is best applied as an electron donating material when used in simple bilayer structures, as it yielded comparable OPV device efficiencies to that of the more well-established and highly optimized chloro-boron subphthalocyanine (Cl-BsubPc) OPV device structures. Thereafter we established that the HOMO/LUMO energy levels of μ-oxo-(BsubPc)2 are well-placed to apply it as a bifunctional donor/acceptor interlayer material in both energy and charge cascade OPV device architectures. Within this context, we found that μ-oxo-(BsubPc)2 was particularly effective in a charge cascade device as an interlayer between Cl-BsubPc and C70. We finally found evidence of an alloying-like effect for devices with mixed electron donor layers of (Cl-BsubPc) and μ-oxo-(BsubPc)2, achieved through co-deposition. The overarching conclusion is therefore that μ-oxo-(BsubPc)2 has the ability to improve the performance of Cl-BsubPc OPV devices and is a multifunctional material worthy of further study.

  3. Plasma-based accelerator structures

    SciTech Connect

    Schroeder, Carl B.

    1999-12-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas.

  4. The USL NASA PC R and D project: General specifications of objectives

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor)

    1984-01-01

    Given here are the general specifications of the objectives of the University of Southwestern Louisiana Data Base Management System (USL/DBMS) NASA PC R and D Project, a project initiated to address future R and D issues related to PC-based processing environments acquired pursuant to the NASA contract work; namely, the IBM PC/XT systems.

  5. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive...

  6. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive...

  7. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868... SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO 2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a...

  8. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive...

  9. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868... SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO 2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a...

  10. 21 CFR 868.2500 - Cutaneous oxygen (PcO2) monitor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cutaneous oxygen (PcO2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  11. 21 CFR 868.2500 - Cutaneous oxygen (PcO 2) monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cutaneous oxygen (PcO 2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO 2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  12. 21 CFR 868.2500 - Cutaneous oxygen (PcO2) monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cutaneous oxygen (PcO2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  13. 21 CFR 868.2500 - Cutaneous oxygen (PcO 2) monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cutaneous oxygen (PcO 2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO 2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  14. 21 CFR 868.2500 - Cutaneous oxygen (PcO2) monitor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cutaneous oxygen (PcO2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  15. Activated T cells exhibit increased uptake of silicon phthalocyanine Pc 4 and increased susceptibility to Pc 4-photodynamic therapy-mediated cell death.

    PubMed

    Soler, David C; Ohtola, Jennifer; Sugiyama, Hideaki; Rodriguez, Myriam E; Han, Ling; Oleinick, Nancy L; Lam, Minh; Baron, Elma D; Cooper, Kevin D; McCormick, Thomas S

    2016-06-08

    Photodynamic therapy (PDT) is an emerging treatment for malignant and inflammatory dermal disorders. Photoirradiation of the silicon phthalocyanine (Pc) 4 photosensitizer with red light generates singlet oxygen and other reactive oxygen species to induce cell death. We previously reported that Pc 4-PDT elicited cell death in lymphoid-derived (Jurkat) and epithelial-derived (A431) cell lines in vitro, and furthermore that Jurkat cells were more sensitive than A431 cells to treatment. In this study, we examined the effectiveness of Pc 4-PDT on primary human CD3(+) T cells in vitro. Fluorometric analyses of lysed T cells confirmed the dose-dependent uptake of Pc 4 in non-stimulated and stimulated T cells. Flow cytometric analyses measuring annexin V and propidium iodide (PI) demonstrated a dose-dependent increase of T cell apoptosis (6.6-59.9%) at Pc 4 doses ranging from 0-300 nM. Following T cell stimulation through the T cell receptor using a combination of anti-CD3 and anti-CD28 antibodies, activated T cells exhibited increased susceptibility to Pc 4-PDT-induced apoptosis (10.6-81.2%) as determined by Pc 4 fluorescence in each cell, in both non-stimulated and stimulated T cells, Pc 4 uptake increased with Pc 4 dose up to 300 nM as assessed by flow cytometry. The mean fluorescence intensity (MFI) of Pc 4 uptake measured in stimulated T cells was significantly increased over the uptake of resting T cells at each dose of Pc 4 tested (50, 100, 150 and 300 nM, p < 0.001 between 50 and 150 nM, n = 8). Treg uptake was diminished relative to other T cells. Cutaneous T cell lymphoma (CTCL) T cells appeared to take up somewhat more Pc 4 than normal resting T cells at 100 and 150 nm Pc 4. Confocal imaging revealed that Pc 4 localized in cytoplasmic organelles, with approximately half of the Pc 4 co-localized with mitochondria in T cells. Thus, Pc 4-PDT exerts an enhanced apoptotic effect on activated CD3(+) T cells that may be exploited in targeting T cell-mediated skin

  16. Perturbations for transient acceleration

    SciTech Connect

    Vargas, Cristofher Zuñiga; Zimdahl, Winfried; Hipólito-Ricaldi, Wiliam S. E-mail: hipolito@ceunes.ufes.br

    2012-04-01

    According to the standard ΛCDM model, the accelerated expansion of the Universe will go on forever. Motivated by recent observational results, we explore the possibility of a finite phase of acceleration which asymptotically approaches another period of decelerated expansion. Extending an earlier study on a corresponding homogeneous and isotropic dynamics, in which interactions between dark matter and dark energy are crucial, the present paper also investigates the dynamics of the matter perturbations both on the Newtonian and General Relativistic (GR) levels and quantifies the potential relevance of perturbations of the dark-energy component. In the background, the model is tested against the Supernova type Ia (SNIa) data of the Constitution set and on the perturbative level against growth rate data, among them those of the WiggleZ survey, and the data of the 2dFGRS project. Our results indicate that a transient phase of accelerated expansion is not excluded by current observations.

  17. Uniform acceleration in general relativity

    NASA Astrophysics Data System (ADS)

    Friedman, Yaakov; Scarr, Tzvi

    2015-10-01

    We extend de la Fuente and Romero's (Gen Relativ Gravit 47:33, 2015) defining equation for uniform acceleration in a general curved spacetime from linear acceleration to the full Lorentz covariant uniform acceleration. In a flat spacetime background, we have explicit solutions. We use generalized Fermi-Walker transport to parallel transport the Frenet basis along the trajectory. In flat spacetime, we obtain velocity and acceleration transformations from a uniformly accelerated system to an inertial system. We obtain the time dilation between accelerated clocks. We apply our acceleration transformations to the motion of a charged particle in a constant electromagnetic field and recover the Lorentz-Abraham-Dirac equation.

  18. Free-breathing black-blood CINE fast-spin echo imaging for measuring abdominal aortic wall distensibility: A feasibility study.

    PubMed

    Lin, Jyh-Miin; Patterson, Andrew; Chao, Tzu-Cheng; Zhu, Chengcheng; Chang, Hing-Chiu; Mendes, Jason; Chung, Hsiao-Wen; Gillard, Jonathan; Graves, Martin

    2017-03-22

    The paper reports a free-breathing black-blood CINE fast-spin echo (FSE) technique for measuring abdominal aortic wall motion. The free-breathing CINE FSE includes the following MR techniques: 1) variable-density sampling with fast iterative reconstruction; 2) inner-volume imaging; and 3) a blood-suppression preparation pulse. The proposed technique was evaluated in eight healthy subjects. The inner-volume imaging significantly reduced the intraluminal artifacts of respiratory motion (p = 0.015). The quantitative measurements were a diameter of 16.3 ± 2.8 mm and wall distensibility of 2.0 ± 0.4 mm (12.5 ± 3.4%) and 0.7 ± 0.3 mm (4.1 ± 1.0%) for the anterior and posterior walls, respectively. The cyclic cross-sectional distensibility was 35 ± 15% greater in the systolic phase than in the diastolic phase. In conclusion, we developed a feasible CINE FSE method to measure the motion of the abdominal aortic wall, which will enable clinical scientists to study the elasticity of the abdominal aorta.

  19. Microelectromechanical acceleration-sensing apparatus

    DOEpatents

    Lee, Robb M.; Shul, Randy J.; Polosky, Marc A.; Hoke, Darren A.; Vernon, George E.

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  20. 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.

  1. The Computer Program LIAR for Beam Dynamics Calculations in Linear Accelerators

    SciTech Connect

    Assmann, R.W.; Adolphsen, C.; Bane, K.; Raubenheimer, T.O.; Siemann, R.H.; Thompson, K.; /SLAC

    2011-08-26

    Linear accelerators are the central components of the proposed next generation of linear colliders. They need to provide acceleration of up to 750 GeV per beam while maintaining very small normalized emittances. Standard simulation programs, mainly developed for storage rings, do not meet the specific requirements for high energy linear accelerators. We present a new program LIAR ('LInear Accelerator Research code') that includes wakefield effects, a 6D coupled beam description, specific optimization algorithms and other advanced features. Its modular structure allows to use and to extend it easily for different purposes. The program is available for UNIX workstations and Windows PC's. It can be applied to a broad range of accelerators. We present examples of simulations for SLC and NLC.

  2. 'Light Sail' Acceleration Reexamined

    SciTech Connect

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-08-21

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for 'optimal' values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple 'light sail' model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  3. HIGH GRADIENT INDUCTION ACCELERATOR

    SciTech Connect

    Caporaso, G J; Sampayan, S; Chen, Y; Blackfield, D; Harris, J; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Nunnally, W; Paul, A; Poole, B; Rhodes, M; Sanders, D; Selenes, K; Sullivan, J; Wang, L; Watson, J

    2007-06-21

    A new type of compact induction accelerator is under development at the Lawrence Livermore National Laboratory that promises to increase the average accelerating gradient by at least an order of magnitude over that of existing induction machines. The machine is based on the use of high gradient vacuum insulators, advanced dielectric materials and switches and is stimulated by the desire for compact flash x-ray radiography sources. Research describing an extreme variant of this technology aimed at proton therapy for cancer will be described. Progress in applying this technology to several applications will be reviewed.

  4. "Light sail" acceleration reexamined.

    PubMed

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-08-21

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for "optimal" values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple "light sail" model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  5. High intensity hadron accelerators

    SciTech Connect

    Teng, L.C.

    1989-05-01

    This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics.

  6. CLIPS - C LANGUAGE INTEGRATED PRODUCTION SYSTEM (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Riley, G.

    1994-01-01

    The C Language Integrated Production System, CLIPS, is a shell for developing expert systems. It is designed to allow artificial intelligence research, development, and delivery on conventional computers. The primary design goals for CLIPS are portability, efficiency, and functionality. For these reasons, the program is written in C. CLIPS meets or outperforms most micro- and minicomputer based artificial intelligence tools. CLIPS is a forward chaining rule-based language. The program contains an inference engine and a language syntax that provide a framework for the construction of an expert system. It also includes tools for debugging an application. CLIPS is based on the Rete algorithm, which enables very efficient pattern matching. The collection of conditions and actions to be taken if the conditions are met is constructed into a rule network. As facts are asserted either prior to or during a session, CLIPS pattern-matches the number of fields. Wildcards and variables are supported for both single and multiple fields. CLIPS syntax allows the inclusion of externally defined functions (outside functions which are written in a language other than CLIPS). CLIPS itself can be embedded in a program such that the expert system is available as a simple subroutine call. Advanced features found in CLIPS version 4.3 include an integrated microEMACS editor, the ability to generate C source code from a CLIPS rule base to produce a dedicated executable, binary load and save capabilities for CLIPS rule bases, and the utility program CRSV (Cross-Reference, Style, and Verification) designed to facilitate the development and maintenance of large rule bases. Five machine versions are available. Each machine version includes the source and the executable for that machine. The UNIX version includes the source and binaries for IBM RS/6000, Sun3 series, and Sun4 series computers. The UNIX, DEC VAX, and DEC RISC Workstation versions are line oriented. The PC version and the Macintosh

  7. Ionospheric signatures of cusp latitude Pc 3 pulsations

    SciTech Connect

    Engebretson, M.J.; Anderson, B.J. ); Cahill, L.J. Jr. ); Arnoldy, R.L. ); Rosenberg, T.J. ); Carpenter, D.L. ); Gail, W.B. ); Eather, R.H. )

    1990-03-01

    The authors have compared search coil magnetometer, riometer, photometer, and ELF-VLF receiver data obtained at South Pole Station and McMurdo, Antarctica, during selected days in March and April 1986. Narrow-band magnetic pulsations in the Pc 3 period range are observed simultaneously at both stations in the dayside sector during times of low interplanetary magnetic field (IMF) cone angle, but are considerably stronger at South Pole, which is located at a latitude near the nominal foot point of the daysie cusp/cleft region. Pulsations in auroral light a 427.8 nm wavelength are often observed with magnetic pulsations at South Pole, but such optical pulsations are not observed at McMurdo. When Pc 3 pulsations are present, they exhibit nearly identical frequencies, proportional to the magnitude of the IMF, in magnetometer, photometer, and ELF-VLF receiver signals at South Pole Station and in magnetometer signals at McMurdo. Singals from the 30-MHz riometer at South Pole are modulated in concert with the magnetic and optical variations during periods of broadband pulsation activity, but no riometer variations are noted during periods of narrow-band activity. Because riometers are sensitive to electrons of auroral energies (several keV and above), while the 427.8-nm photometer is sensitive to precipitation with much lower energies, they interpret these observatons as showing that precipitating magnetosheathlike electrons (with energies {le} 1 keV) at nominal dayside cleft latitudes are at times modulated with frequencies similar to those of upstream waves. They suggest that these particles may play an important role, via modification of ionospheric currents and conductivities, in the transmission of upstream wave signals into the magnetosphere and in the generation of dayside high-latitude Pc 3 pulsations.

  8. A versatile, PC-based gamma ray monitor.

    PubMed

    Drndarevic, V; Jevtic, N

    2008-01-01

    This paper describes a new computer-based gamma ray monitor for laboratory and field measurements. The monitor consists of a universal peripheral device, and GM counter gamma ray probe, connected via USB to the PC. The peripheral device is generic; in addition to the GM probe, it accepts sensors for spectrometric measurements as well as sensors for the measurement of other environmental parameters. Owing to its low-power consumption, it is used with laptop or palmtop computer, as a portable field measurement instrument. The proposed solution has advantages over conventional instrument: (1) open architecture; (2) user-defined functions and (3) easy network connection.

  9. Wf/pc Cycle 2 Calib: Measles Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1991-07-01

    This program takes "uniform illuminated" pictures of the earth to monitor the measles effect observed in WFPC observations. The goals of this program are: 1. Look for changes in measle numbers/characteristics 2. Have before/after images in place for decontaminations. This program will also build up a high quality flat field. The observations are done only with PC with a frequency of once every two weeks. The sequence (during a single earth occultation) is: F517N+OPEN, F517N+F122M, F517N+OPEN

  10. Wf/pc Cycle 1 CALIB:RECIPROCITY Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This program takes "uniform illuminated" pictures of the earth to monitor the "reciprocity" effect observed in earth calib observations. The goals of this program are: 1. Watch for discrete changes in this behavior 2. Look for long term variability 3. Have before/after checks in place for decontaminations safings, or UVflood. This program will also build up a high quality flat field. The observations are done only with PC with a frequency of once every week. The sequence (during a single earth occultation) is: F517N+OPEN, F517N+F122M, F517N+OPEN

  11. Casing centralization calculation in horizontal wells using PC's

    SciTech Connect

    Chen, P.; Wu, J. )

    1991-09-01

    In this paper the three-moments-equation method is used to calculate casing deflection and centralizer spacing in horizontal wells. This method, when used with a PC, makes it possible to study in detail the deflection of a casing string as a continuous beam in a horizontal wellbore. In particular, this approach makes it possible to study the near-end effect of the casing shoe on the deflection of the other spans in the casing string. Casing deflection in the transition zone where the centralizer spacing changes from one value to another and the casing deflection for an overhang at the casing shoe can also be studied. Examples are presented.

  12. Laser Triggered Electron Injection into a Channel Guided Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Filip, C.

    2005-10-01

    Laser-plasma accelerators have demonstrated the generation of narrow energy spread (˜ few %) electron beams with considerable amount of charge (>100 pC). Stability of laser-plasma accelerators, as in the conventional accelerators, requires highly synchronized injection of electrons into the structured accelerating field. The Colliding Pulse Method[1] with pre-formed plasma channel guiding [2] can result in jitter-free injection in a dark-current-free accelerating structure. We report on experimental progress of laser triggered injection of electrons into a laser wakefield, where an intense laser pulse is guided by a pre-formed plasma channel. The experiments use the multi-beam, multi-terawatt Ti:Al2O3 laser at LOASIS facility of LBNL. The ignitor-heater method is used to first produce a pre-formed plasma channel in a hydrogen gas jet. Two counter propagating beams (wakefield driver:100-500mJ-50fs, injector:50-300mJ-50fs) then are focused onto the entrance of the channel. Preliminary results indicate that electron beam properties are affected by the second beam. Details of the experiment will be presented. [1]G.Fubiani, et al, Phys. Rev. E 70, 016402 (2004). [2]C.G.R. Geddes et al, Nature 431, 538 (2004). This work is supported by DoE under contract DE-AC02-05CH11231.

  13. Radioisotope Dating with Accelerators.

    ERIC Educational Resources Information Center

    Muller, Richard A.

    1979-01-01

    Explains a new method of detecting radioactive isotopes by counting their accelerated ions rather than the atoms that decay during the counting period. This method increases the sensitivity by several orders of magnitude, and allows one to find the ages of much older and smaller samples. (GA)

  14. Accelerated Management Development

    ERIC Educational Resources Information Center

    Munn, Kenn

    1974-01-01

    Western Electric's accelerated management development program for hand picked college graduate students consists of a high risk training project in which the management candidate accomplishes his task or is terminated. The success of such projects puts candidates in third level management in seven years or half the normal time. (DS)

  15. 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.

  16. Combined generating-accelerating buncher for compact linear accelerators

    NASA Astrophysics Data System (ADS)

    Savin, E. A.; Matsievskiy, S. V.; Sobenin, N. P.; Sokolov, I. D.; Zavadtsev, A. A.

    2016-09-01

    Described in the previous article [1] method of the power extraction from the modulated electron beam has been applied to the compact standing wave electron linear accelerator feeding system, which doesnt require any connection waveguides between the power source and the accelerator itself [2]. Generating and accelerating bunches meet in the hybrid accelerating cell operating at TM020 mode, thus the accelerating module is placed on the axis of the generating module, which consists from the pulsed high voltage electron sources and electrons dumps. This combination makes the accelerator very compact in size which is very valuable for the modern applications such as portable inspection sources. Simulations and geometry cold tests are presented.

  17. SU-E-J-238: First-Order Approximation of Time-Resolved 4DMRI From Cine 2DMRI and Respiratory-Correlated 4DMRI

    SciTech Connect

    Li, G; Tyagi, N; Deasy, J; Wei, J; Hunt, M

    2015-06-15

    Purpose: Cine 2DMRI is useful in MR-guided radiotherapy but it lacks volumetric information. We explore the feasibility of estimating timeresolved (TR) 4DMRI based on cine 2DMRI and respiratory-correlated (RC) 4DMRI though simulation. Methods: We hypothesize that a volumetric image during free breathing can be approximated by interpolation among 3DMRI image sets generated from a RC-4DMRI. Two patients’ RC-4DMRI with 4 or 5 phases were used to generate additional 3DMRI by interpolation. For each patient, six libraries were created to have total 5-to-35 3DMRI images by 0–6 equi-spaced tri-linear interpolation between adjacent and full-inhalation/full-exhalation phases. Sagittal cine 2DMRI were generated from reference 3DMRIs created from separate, unique interpolations from the original RC-4DMRI. To test if accurate 3DMRI could be generated through rigid registration of the cine 2DMRI to the 3DMRI libraries, each sagittal 2DMRI was registered to sagittal cuts in the same location in the 3DMRI within each library to identify the two best matches: one with greater lung volume and one with smaller. A final interpolation between the corresponding 3DMRI was then performed to produce the first-order-approximation (FOA) 3DMRI. The quality and performance of the FOA as a function of library size was assessed using both the difference in lung volume and average voxel intensity between the FOA and the reference 3DMRI. Results: The discrepancy between the FOA and reference 3DMRI decreases as the library size increases. The 3D lung volume difference decreases from 5–15% to 1–2% as the library size increases from 5 to 35 image sets. The average difference in lung voxel intensity decreases from 7–8 to 5–6 with the lung intensity being 0–135. Conclusion: This study indicates that the quality of FOA 3DMRI improves with increasing 3DMRI library size. On-going investigations will test this approach using actual cine 2DMRI and introduce a higher order approximation for

  18. Regulation of Fusion Pore Closure and Compound Exocytosis in Neuroendocrine PC12 Cells by SCAMP1

    PubMed Central

    Zhang, Jie; Castle, David

    2011-01-01

    During exocytosis, neuroendocrine cells can achieve partial release of stored secretory products from dense core vesicles (DCVs) by coupling endocytosis directly at fusion sites and without full discharge. The physiological role of partial secretion is of substantial interest. Much is known about SNARE-mediated initiation of exocytosis and dynamin-mediated completion of endocytosis, but little is known about coupling events. We have used real-time microscopy to examine the role of secretory carrier membrane protein SCAMP1 in exo-endocytic coupling in PC12 cells. While reduced SCAMP1 expression is known to impede dilation of newly opened fusion pores during onset of DCV exocytosis, we now show that SCAMP1 deficiency also inhibits closure of fusion pores after they have opened. Inhibition causes accumulation of fusion figures at the plasma membrane. Closure is recovered by restoring expression and accelerated slightly by overexpression. Interestingly, inhibited pore closure resulting from loss of SCAMP1 appears to increase secondary fusion of DCVs to already-fused DCVs (compound exocytosis). Unexpectedly, reinternalization of expanded DCV membranes following compound exocytosis appears to proceed normally in SCAMP1-deficient cells. SCAMP1’s apparent dual role in facilitating dilation and closure of fusion pores implicates its function in exo-endocytic coupling and in the regulation of partial secretion. Secondarily, SCAMP1 may serve to limit the extent of compound exocytosis. PMID:21272170

  19. Development and clinical evaluation of automatic fiducial detection for tumor tracking in cine megavoltage images during volumetric modulated arc therapy

    SciTech Connect

    Azcona, Juan Diego; Li Ruijiang; Mok, Edward; Hancock, Steven; Xing Lei

    2013-03-15

    Purpose: Real-time tracking of implanted fiducials in cine megavoltage (MV) imaging during volumetric modulated arc therapy (VMAT) delivery is complicated due to the inherent low contrast of MV images and potential blockage of dynamic leaves configurations. The purpose of this work is to develop a clinically practical autodetection algorithm for motion management during VMAT. Methods: The expected field-specific segments and the planned fiducial position from the Eclipse (Varian Medical Systems, Palo Alto, CA) treatment planning system were projected onto the MV images. The fiducials were enhanced by applying a Laplacian of Gaussian filter in the spatial domain for each image, with a blob-shaped object as the impulse response. The search of implanted fiducials was then performed on a region of interest centered on the projection of the fiducial when it was within an open field including the case when it was close to the field edge or partially occluded by the leaves. A universal template formula was proposed for template matching and normalized cross correlation was employed for its simplicity and computational efficiency. The search region for every image was adaptively updated through a prediction model that employed the 3D position of the fiducial estimated from the localized positions in previous images. This prediction model allowed the actual fiducial position to be tracked dynamically and was used to initialize the search region. The artifacts caused by electronic interference during the acquisition were effectively removed. A score map was computed by combining both morphological information and image intensity. The pixel location with the highest score was selected as the detected fiducial position. The sets of cine MV images taken during treatment were analyzed with in-house developed software written in MATLAB (The Mathworks, Inc., Natick, MA). Five prostate patients were analyzed to assess the algorithm performance by measuring their positioning

  20. [PC-1 enhances c-myc gene expression in prostate cancer cells].

    PubMed

    Yu, Lan; Shi, Qing-Guo; Qian, Xiao-Long; Li, Shan-Hu; Wang, Hong-Tao; Wang, Le-Le; Zhou, Jian-Guang

    2010-04-01

    PC-1(Prostate and colon gene 1) gene belongs to TPD52 (Tumor Protein D52) gene family. The expression of PC-1 is found to promote androgen-independent progression. This study was conducted to assess the mechnism of promotion of androgen-independent progression in PC-1 gene. The c-myc gene expression was tested by RT-PCR and Western blotting analyses in the LNCaP-pc-1 and LNCaP-zero cell line. After separation of cytoplasm and nulear proteins of the LNCaP-pc-1 and LNCaP-zero cell line, the beta-catenin protein was detected by Western blotting. C4-2 cell line was used to examine the effects of 10058-F4 on the PC-1 gene expression. The results of RT-PCR and Western blotting indicated that PC-1 enhanced c-myc gene expression in prostate cancer cells, PC-1 was also found to enhance beta-catenin expression in nuclear. Furthermore, a small-molecule c-Myc inhibitor, 10058-F4 represses PC-1 gene expression in C4-2 cell line. Our findings suggest that PC-1 enhances c-myc gene expression in prostate cancer cells through the Wnt/beta-catenin pathway. Meanwhile, c-myc plays a feed-forward role in enhancing PC-1 driven c-myc gene expression, and promotes prostate an-drogen-independent progression.

  1. Polycomb Group (PcG) Proteins and Human Cancers: Multifaceted Functions and Therapeutic Implications

    PubMed Central

    Wang, Wei; Qin, Jiang-Jiang; Voruganti, Sukesh; Nag, Subhasree; Zhou, Jianwei; Zhang, Ruiwen

    2016-01-01

    Polycomb group (PcG) proteins are transcriptional repressors that regulate several crucial developmental and physiological processes in the cell. More recently, they have been found to play important roles in human carcinogenesis and cancer development and progression. The deregulation and dysfunction of PcG proteins often lead to blocking or inappropriate activation of developmental pathways, enhancing cellular proliferation, inhibiting apoptosis, and increasing the cancer stem cell population. Genetic and molecular investigations of PcG proteins have long been focused on their PcG functions. However, PcG proteins have recently been shown to exert non-polycomb functions, contributing to the regulation of diverse cellular functions. We and others have demonstrated that PcG proteins regulate the expression and function of several oncogenes and tumor suppressor genes in a PcG-independent manner, and PcG proteins are associated with the survival of patients with cancer. In this review, we summarize the recent advances in the research on PcG proteins, including both the polycomb-repressive and non-polycomb functions. We specifically focus on the mechanisms by which PcG proteins play roles in cancer initiation, development, and progression. Finally, we discuss the potential value of PcG proteins as molecular biomarkers for the diagnosis and prognosis of cancer, and as molecular targets for cancer therapy. PMID:26227500

  2. Neurodegeneration in accelerated aging.

    PubMed

    Scheibye-Knudsen, Moren

    2016-11-01

    The growing proportion of elderly people represents an increasing economic burden, not least because of age-associated diseases that pose a significant cost to the health service. Finding possible interventions to age-associated disorders therefore have wide ranging implications. A number of genetically defined accelerated aging diseases have been characterized that can aid in our understanding of aging. Interestingly, all these diseases are associated with defects in the maintenance of our genome. A subset of these disorders, Cockayne syndrome, Xeroderma pigmentosum group A and ataxia-telangiectasia, show neurological involvement reminiscent of what is seen in primary human mitochondrial diseases. Mitochondria are the power plants of the cells converting energy stored in oxygen, sugar, fat, and protein into ATP, the energetic currency of our body. Emerging evidence has linked this organelle to aging and finding mitochondrial dysfunction in accelerated aging disorders thereby strengthens the mitochondrial theory of aging. This theory states that an accumulation of damage to the mitochondria may underlie the process of aging. Indeed, it appears that some accelerated aging disorders that show neurodegeneration also have mitochondrial dysfunction. The mitochondrial alterations may be secondary to defects in nuclear DNA repair. Indeed, nuclear DNA damage may lead to increased energy consumption, alterations in mitochondrial ATP production and defects in mitochondrial recycling, a term called mitophagy. These changes may be caused by activation of poly-ADP-ribose-polymerase 1 (PARP1), an enzyme that responds to DNA damage. Upon activation PARP1 utilizes key metabolites that attenuate pathways that are normally protective for the cell. Notably, pharmacological inhibition of PARP1 or reconstitution of the metabolites rescues the changes caused by PARP1 hyperactivation and in many cases reverse the phenotypes associated with accelerated aging. This implies that modulation

  3. Menopause accelerates biological aging

    PubMed Central

    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

    2016-01-01

    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

  4. Human transcriptional coactivator PC4 stimulates DNA end joining and activates DSB repair activity.

    PubMed

    Batta, Kiran; Yokokawa, Masatoshi; Takeyasu, Kunio; Kundu, Tapas K

    2009-01-23

    Human transcriptional coactivator PC4 is a highly abundant nuclear protein that is involved in diverse cellular processes ranging from transcription to chromatin organization. Earlier, we have shown that PC4, a positive activator of p53, overexpresses upon genotoxic insult in a p53-dependent manner. In the present study, we show that PC4 stimulates ligase-mediated DNA end joining irrespective of the source of DNA ligase. Pull-down assays reveal that PC4 helps in the association of DNA ends through its C-terminal domain. In vitro nonhomologous end-joining assays with cell-free extracts show that PC4 enhances the joining of noncomplementary DNA ends. Interestingly, we found that PC4 activates double-strand break (DSB) repair activity through stimulation of DSB rejoining in vivo. Together, these findings demonstrate PC4 as an activator of nonhomologous end joining and DSB repair activity.

  5. Ionospheric signatures of cusp latitude Pc 3 pulsations

    NASA Technical Reports Server (NTRS)

    Engebretson, M. J.; Anderson, B. J.; Cahill, L. J., Jr.; Arnoldy, R. L.; Rosenberg, T. J.

    1990-01-01

    Search coil magnetometer, riometer, photometer, and ELF-VLF receiver data obtained at South Pole Station and McMurdo, Antarctica during selected days in March and April 1986 are compared. Narrow-band magnetic pulsations in the Pc 3 period range are observed simultaneously at both stations in the dayside sector during times of low IMF cone angle, but are considerably stronger at South Pole, which is located at a latitude near the nominal foot point of the dayside cusp/cleft region. Pulsations in auroral light at 427.8 nm wavelength are often observed with magnetic pulsations at South Pole, but such optical pulsations are not observed at McMurdo. The observations suggest that precipitating magnetosheathlike electrons at nominal dayside cleft latitudes are at times modulated with frequencies similar to those of upstream waves. These particles may play an important role, via modification of ionospheric currents and conductivities, in the transmission of upstream wave signals into the magnetosphere and in the generation of dayside high-latitude Pc 3 pulsations.

  6. Rotordynamics on the PC: Further Capabilities of ARDS

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    1997-01-01

    Rotordynamics codes for personal computers are now becoming available. One of the most capable codes is Analysis of RotorDynamic Systems (ARDS) which uses the component mode synthesis method to analyze a system of up to 5 rotating shafts. ARDS was originally written for a mainframe computer but has been successfully ported to a PC; its basic capabilities for steady-state and transient analysis were reported in an earlier paper. Additional functions have now been added to the PC version of ARDS. These functions include: 1) Estimation of the peak response following blade loss without resorting to a full transient analysis; 2) Calculation of response sensitivity to input parameters; 3) Formulation of optimum rotor and damper designs to place critical speeds in desirable ranges or minimize bearing loads; 4) Production of Poincard plots so the presence of chaotic motion can be ascertained. ARDS produces printed and plotted output. The executable code uses the full array sizes of the mainframe version and fits on a high density floppy disc. Examples of all program capabilities are presented and discussed.

  7. PC-SEAPAK user's guide, version 4.0

    NASA Technical Reports Server (NTRS)

    Mcclain, Charles R.; Fu, Gary; Darzi, Michael; Firestone, James K.

    1992-01-01

    PC-SEAPAK is designed to provide a complete and affordable capability for processing and analysis of NOAA Advanced Very High Resolution Radiometer (AVHRR) and Nimbus-7 Coastal Zone Color Scanner (CZCS) data. Since the release of version 3.0 over a year ago, significant revisions were made to the AVHRR and CZCS programs and to the statistical data analysis module, and a number of new programs were added. This new version has 114 procedures listed in its menus. The package continues to emphasize user-friendliness and interactive data analysis. Additionally, because the scientific goals of the ocean color research being conducted have shifted to larger space and time scales, batch processing capabilities were enhanced, allowing large quantities of data to be easily ingested and analyzed. The development of PC-SEAPAK was paralled by two other activities that were influential and assistive: the global CZCS processing effort at GSFC and the continued development of VAX-SEAPAK. SEAPAK incorporates the instrument calibration and support all levels of data available from the CZCS archive.

  8. Commodity clusters: Performance comparison between PC`s and workstations

    SciTech Connect

    Carter, R.; Laroco, J.; Armstrong, R.

    1996-03-01

    Workstation clusters were originally developed as a way to leverage the better cost basis of UNIX workstations to perform computations previously handled only by relatively more expensive supercomputers. Commodity workstation clusters take this evolutionary process one step further by replacing equivalent proprietary workstation functionality with less expensive PC technology. As PC technology encroaches on proprietary UNIX workstation vendor markets, these vendors will see a declining share of the overall market. As technology advances continue, the ability to upgrade a workstations performance plays a large role in cost analysis. For example, a major upgrade to a typical UNIX workstation means replacing the whole machine. As major revisions to the UNIX vendor`s product line come out, brand new systems are introduced. IBM compatibles, however, are modular by design, and nothing need to be replaced except the components that are truly improved. The DAISy cluster, for example, is about to undergo a major upgrade from 90MHz Pentiums to 200MHz Pentium Pros. All of the memory -- the system`s largest expense -- and disks, power supply, etc., can be reused. As a result, commodity workstation clusters ought to gain an increasingly large share of the distributed computing market.

  9. Interhemispheric asymmetry of the amplitudes of Pc3 geomagnetic pulsations

    NASA Astrophysics Data System (ADS)

    Heilig, B.; Pilipenko, V.; Sutcliffe, P.

    2012-04-01

    The interhemispheric asymmetry between the amplitude of geomagnetic pulsations was realised already in the 1960s'. Most of the observers (Yumoto et al., 1988; Saito et al., 1989; Takahashi et al., 1994; Obana et al., 2005) reported that the energy of Pc3 (Pc4) pulsations were found to be significantly larger on the winter hemisphere (i.e. in December on the Northern hemisphere and in June in the Southern hemisphere) when comparing conjugate observations. The authors linked this behaviour to the seasonal conductivity changes of the ionosphere, however, no modelling effort were made to explain the observed behaviour. In the presented paper we make an attempt to model the seasonal asymmetry based on the model of Pilipenko et al (2008). Using data recorded at geomagnetically conjugate stations, Tihany (THY, Hungary) and Hermanus (HER, South Africa) between 2002 and 2007 we present a case where an anomalous seasonal variation can be observed. The observed amplitudes were significantly larger in local summer than in local winter, but only in years near the sunspot maximum. This is exactly the opposite what was found for other station pairs. It was also observed that the range of the seasonal variation of the HER/THY ratio diminishes with the decrease of the solar index F10.7. The phenomenon was first realised by Vero (1965) who linked the anomalous winter attenuation of pulsations to the anomalously high F2 region electron density of the ionosphere. A clear physical interpretation of these results is still missing.

  10. CAP88-PC Version 4, an updated radionuclide NESHAPS model.

    PubMed

    Wood, Raymond; Stuenkel, David; Rosnick, Reid

    2013-08-01

    The latest version of the CAP88-PC computer model, Version 4, has many changes and improvements from previous versions. The most significant of these changes from a user perspective are the incorporation of age-dependent radionuclide dose and risk factors for ingestion and inhalation, the increase in the number of included radionuclides, and a change in the file management system used by the program. Other changes less visible to the user include new code architecture, incorporation of numerical solvers for the calculation of radioactive decay chains, including the ingrowth of decay products during air transport and ground surface deposition, enhanced error messages, updated on-line help, and a utility for migrating Version 3 datasets, wind files, and population files to Version 4. The modifications have produced a significant improvement in speed and stability for Version 4 relative to Version 3 and eliminated the solution approximations used in Version 3. The U.S. Environmental Protection Agency has implemented an extensive testing and documentation program for CAP88-PC Version 4 to address user concerns with past versions, resulting in enhanced documentation supporting compatibility with user software quality assurance programs.

  11. Ultrasonic stress measurement using PC based and commercial flaw detectors

    NASA Astrophysics Data System (ADS)

    Santos, Auteliano A.; Bray, Don E.

    2000-09-01

    The determination of the stress field inside metallic parts is one of the most important challenges to the designer. Although the prediction of the stress distribution can be done by several numerical and empirical methods, the real stress value is almost always unknown. Several destructive and nondestructive techniques have been tested to accomplish this task, including the application of x rays, saw cut, neutron diffraction and so on, but none of them seems to have a suitable correlation between cost and applicability. Ultrasonic techniques have been used for flaw detection since the 1950s. The main application was in the identification of cracks and voids. In this work we present the application of ultrasound in the evaluation of a one-dimensional stress field using the longitudinal critically refracted waves (LCR). A new ultrasonic LCR probe is presented and its performance is evaluated using PC based instrumentation. Also, the LCR waves' sensitivity is verified using a low cost commercial flaw detector. The results show that the technique can be applied to quantify the magnitude of the stresses in bars, using either the PC based or the commercial flaw detector system, as long as the high sensitivity longitudinal critically refracted waves are used.

  12. Pro-protein convertases (PCs) other than PC6 are not tightly regulated for implantation in the human endometrium.

    PubMed

    Freyer, C; Kilpatrick, L M; Salamonsen, L A; Nie, G

    2007-06-01

    Pro-protein convertases (PCs) are a family of serine proteases (furin, PC1/3, PC2, PACE4, PC4, PC5/6, PC7/8) responsible for post-translational processing and activation of inactive precursors of many regulatory proteins. Endometrial PC6 is critical for implantation in mice and for decidualization of human endometrial stromal cells (ESCs). This study investigated the endometrial expression of other PCs during the menstrual cycle and early pregnancy to elucidate potential redundancies. Furin, PC4, PACE4, and PC7 along with PC6 transcripts were detected in total endometrial RNA, whereas PC1 and PC2 transcription levels were negligible. Quantitative RT-PCR demonstrated highest levels of furin mRNA during menstruation and lowest levels during the proliferative phase. Furin protein was immunolocalized in endometrial luminal and glandular epithelia, stromal fibroblasts, endothelia, and leukocytes. PACE4 and PC7 proteins were also immunodetected in endometrial stroma and glands. Total furin, PC7, and PACE4 proteins were constitutive in both stromal and glandular compartments throughout the cycle and during first trimester pregnancy. Furthermore, Furin and PC7 transcription was unaltered during decidualization of ESCs in vitro in contrast to PC6 which is significantly up-regulated during decidualization. Thus, whereas PC6 is tightly regulated during endometrial preparation for implantation, furin, PACE4, and PC7 are constitutively expressed in human endometrium, but must be considered if PC6 is to be targeted for manipulation of fertility.

  13. COMPPAP - COMPOSITE PLATE BUCKLING ANALYSIS PROGRAM (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Smith, J. P.

    1994-01-01

    The Composite Plate Buckling Analysis Program (COMPPAP) was written to help engineers determine buckling loads of orthotropic (or isotropic) irregularly shaped plates without requiring hand calculations from design curves or extensive finite element modeling. COMPPAP is a one element finite element program that utilizes high-order displacement functions. The high order of the displacement functions enables the user to produce results more accurate than traditional h-finite elements. This program uses these high-order displacement functions to perform a plane stress analysis of a general plate followed by a buckling calculation based on the stresses found in the plane stress solution. The current version assumes a flat plate (constant thickness) subject to a constant edge load (normal or shear) on one or more edges. COMPPAP uses the power method to find the eigenvalues of the buckling problem. The power method provides an efficient solution when only one eigenvalue is desired. Once the eigenvalue is found, the eigenvector, which corresponds to the plate buckling mode shape, results as a by-product. A positive feature of the power method is that the dominant eigenvalue is the first found, which is this case is the plate buckling load. The reported eigenvalue expresses a load factor to induce plate buckling. COMPPAP is written in ANSI FORTRAN 77. Two machine versions are available from COSMIC: a PC version (MSC-22428), which is for IBM PC 386 series and higher computers and compatibles running MS-DOS; and a UNIX version (MSC-22286). The distribution medium for both machine versions includes source code for both single and double precision versions of COMPPAP. The PC version includes source code which has been optimized for implementation within DOS memory constraints as well as sample executables for both the single and double precision versions of COMPPAP. The double precision versions of COMPPAP have been successfully implemented on an IBM PC 386 compatible running

  14. SU-E-J-112: The Impact of Cine EPID Image Acquisition Frame Rate On Markerless Soft-Tissue Tracking

    SciTech Connect

    Yip, S; Rottmann, J; Berbeco, R

    2014-06-01

    Purpose: Although reduction of the cine EPID acquisition frame rate through multiple frame averaging may reduce hardware memory burden and decrease image noise, it can hinder the continuity of soft-tissue motion leading to poor auto-tracking results. The impact of motion blurring and image noise on the tracking performance was investigated. Methods: Phantom and patient images were acquired at a frame rate of 12.87Hz on an AS1000 portal imager. Low frame rate images were obtained by continuous frame averaging. A previously validated tracking algorithm was employed for auto-tracking. The difference between the programmed and auto-tracked positions of a Las Vegas phantom moving in the superior-inferior direction defined the tracking error (δ). Motion blurring was assessed by measuring the area change of the circle with the greatest depth. Additionally, lung tumors on 1747 frames acquired at eleven field angles from four radiotherapy patients are manually and automatically tracked with varying frame averaging. δ was defined by the position difference of the two tracking methods. Image noise was defined as the standard deviation of the background intensity. Motion blurring and image noise were correlated with δ using Pearson correlation coefficient (R). Results: For both phantom and patient studies, the auto-tracking errors increased at frame rates lower than 4.29Hz. Above 4.29Hz, changes in errors were negligible with δ<1.60mm. Motion blurring and image noise were observed to increase and decrease with frame averaging, respectively. Motion blurring and tracking errors were significantly correlated for the phantom (R=0.94) and patient studies (R=0.72). Moderate to poor correlation was found between image noise and tracking error with R -0.58 and -0.19 for both studies, respectively. Conclusion: An image acquisition frame rate of at least 4.29Hz is recommended for cine EPID tracking. Motion blurring in images with frame rates below 4.39Hz can substantially reduce the

  15. Development and evaluation of a semiautomatic segmentation method for the estimation of LV parameters on cine MR images

    NASA Astrophysics Data System (ADS)

    Mazonakis, Michalis; Grinias, Elias; Pagonidis, Konstantin; Tziritas, George; Damilakis, John

    2010-02-01

    The purpose of this study was to develop and evaluate a semiautomatic method for left ventricular (LV) segmentation on cine MR images and subsequent estimation of cardiac parameters. The study group comprised cardiac MR examinations of 18 consecutive patients with known or suspected coronary artery disease. The new method allowed the automatic detection of the LV endocardial and epicardial boundaries on each short-axis cine MR image using a Bayesian flooding segmentation algorithm and weighted least-squares B-splines minimization. Manual editing of the automatic contours could be performed for unsatisfactory segmentation results. The end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and LV mass estimated by the new method were compared with the reference values obtained by manually tracing the LV cavity borders. The reproducibility of the new method was determined using data from two independent observers. The mean number of endocardial and epicardial outlines not requiring any manual adjustment was more than 80% and 76% of the total contour number per study, respectively. The mean segmentation time including the required manual corrections was 2.3 ± 0.7 min per patient. LV volumes estimated by the semiautomatic method were significantly lower than those by manual tracing (P < 0.05), whereas no difference was found for EF and LV mass (P > 0.05). LV indices estimated by the two methods were well correlated (r >= 0.80). The mean difference between manual and semiautomatic method for estimating EDV, ESV, EF and LV mass was 6.1 ± 7.2 ml, 3.0 ± 5.2 ml, -0.6 ± 4.3% and -6.2 ± 12.2 g, respectively. The intraobserver and interobserver variability associated with the semiautomatic determination of LV indices was 0.5-1.2% and 0.8-3.9%, respectively. The estimation of LV parameters with the new semiautomatic segmentation method is technically feasible, highly reproducible and time effective.

  16. Enhanced photodynamic efficacy towards melanoma cells by encapsulation of Pc4 in silica nanoparticles

    SciTech Connect

    Zhao Baozhong; Yin Junjie; Bilski, Piotr J.; Chignell, Colin F.; Roberts, Joan E.; He Yuying

    2009-12-01

    Nanoparticles have been explored recently as an efficient means of delivering photosensitizers for cancer diagnosis and photodynamic therapy (PDT). Silicon phthalocyanine 4 (Pc4) is currently being clinically tested as a photosensitizer for PDT. Unfortunately, Pc4 aggregates in aqueous solutions, which dramatically reduces its PDT efficacy and therefore limits its clinical application. We have encapsulated Pc4 using silica nanoparticles (Pc4SNP), which not only improved the aqueous solubility, stability, and delivery of the photodynamic drug but also increased its photodynamic efficacy compared to free Pc4 molecules. Pc4SNP generated photo-induced singlet oxygen more efficiently than free Pc4 as measured by chemical probe and EPR trapping techniques. Transmission electron microscopy and dynamic light scattering measurements showed that the size of the particles is in the range of 25-30 nm. Cell viability measurements demonstrated that Pc4SNP was more phototoxic to A375 or B16-F10 melanoma cells than free Pc4. Pc4SNP photodamaged melanoma cells primarily through apoptosis. Irradiation of A375 cells in the presence of Pc4SNP resulted in a significant increase in intracellular protein-derived peroxides, suggesting a Type II (singlet oxygen) mechanism for phototoxicity. More Pc4SNP than free Pc4 was localized in the mitochondria and lysosomes. Our results show that these stable, monodispersed silica nanoparticles may be an effective new formulation for Pc4 in its preclinical and clinical studies. We expect that modifying the surface of silicon nanoparticles encapsulating the photosensitizers with antibodies specific to melanoma cells will lead to even better early diagnosis and targeted treatment of melanoma in the future.

  17. Enhanced Photodynamic Efficacy towards Melanoma Cells by Encapsulation of Pc4 in Silica Nanoparticles

    PubMed Central

    Zhao, Baozhong; Yin, Jun-Jie; Bilski, Piotr J.; Chignell, Colin F.; Roberts, Joan E.; He, Yu-Ying

    2009-01-01

    Nanoparticles have been explored recently as an efficient means of delivering photosensitizers for cancer diagnosis and photodynamic therapy (PDT). Silicon phthalocyanine 4 (Pc4) is currently being clinically tested as a photosensitizer for PDT. Unfortunately, Pc4 aggregates in aqueous solutions, which dramatically reduces its PDT efficacy and therefore limits its clinical application. We have encapsulated Pc4 using silica nanoparticles (Pc4SNP), which not only improved the aqueous solubility, stability, and delivery of the photodynamic drug but also increased its photodynamic efficacy compared to free Pc4 molecules. Pc4SNP generated photo-induced singlet oxygen more efficiently than free Pc4 as measured by chemical probe and EPR trapping techniques. Transmission electron microscopy and dynamic light scattering measurements showed that the size of the particles is in the range of 25-30 nm. Cell viability measurements demonstrated that Pc4SNP was more phototoxic to A375 or B16-F10 melanoma cells than free Pc4. Pc4SNP photodamaged melanoma cells primarily through apoptosis. Irradiation of A375 cells in the presence of Pc4SNP resulted in a significant increase in intracellular protein-derived peroxides, suggesting a Type II (singlet oxygen) mechanism for phototoxicity. More Pc4SNP than free Pc4 was localized in the mitochondria and lysosomes. Our results show that these stable, monodispersed silica nanoparticles may be an effective new formulation for Pc4 in its preclinical and clinical studies. We expect that modifying the surface of silicon nanoparticles encapsulating the photosensitizers with antibodies specific to melanoma cells will lead to even better early diagnosis and targeted treatment of melanoma in the future. PMID:19695274

  18. Enhanced photodynamic efficacy towards melanoma cells by encapsulation of Pc4 in silica nanoparticles.

    PubMed

    Zhao, Baozhong; Yin, Jun-Jie; Bilski, Piotr J; Chignell, Colin F; Roberts, Joan E; He, Yu-Ying

    2009-12-01

    Nanoparticles have been explored recently as an efficient means of delivering photosensitizers for cancer diagnosis and photodynamic therapy (PDT). Silicon phthalocyanine 4 (Pc4) is currently being clinically tested as a photosensitizer for PDT. Unfortunately, Pc4 aggregates in aqueous solutions, which dramatically reduces its PDT efficacy and therefore limits its clinical application. We have encapsulated Pc4 using silica nanoparticles (Pc4SNP), which not only improved the aqueous solubility, stability, and delivery of the photodynamic drug but also increased its photodynamic efficacy compared to free Pc4 molecules. Pc4SNP generated photo-induced singlet oxygen more efficiently than free Pc4 as measured by chemical probe and EPR trapping techniques. Transmission electron microscopy and dynamic light scattering measurements showed that the size of the particles is in the range of 25-30 nm. Cell viability measurements demonstrated that Pc4SNP was more phototoxic to A375 or B16-F10 melanoma cells than free Pc4. Pc4SNP photodamaged melanoma cells primarily through apoptosis. Irradiation of A375 cells in the presence of Pc4SNP resulted in a significant increase in intracellular protein-derived peroxides, suggesting a Type II (singlet oxygen) mechanism for phototoxicity. More Pc4SNP than free Pc4 was localized in the mitochondria and lysosomes. Our results show that these stable, monodispersed silica nanoparticles may be an effective new formulation for Pc4 in its preclinical and clinical studies. We expect that modifying the surface of silicon nanoparticles encapsulating the photosensitizers with antibodies specific to melanoma cells will lead to even better early diagnosis and targeted treatment of melanoma in the future.

  19. Functional Analysis of Mouse G6pc1 Mutations Using a Novel In Situ Assay for Glucose-6-Phosphatase Activity and the Effect of Mutations in Conserved Human G6PC1/G6PC2 Amino Acids on G6PC2 Protein Expression

    PubMed Central

    Boortz, Kayla A.; Syring, Kristen E.; Pound, Lynley D.; Wang, Yingda; Oeser, James K.; O’Brien, Richard M.

    2016-01-01

    Elevated fasting blood glucose (FBG) has been associated with increased risk for development of type 2 diabetes. Single nucleotide polymorphisms (SNPs) in G6PC2 are the most important common determinants of variations in FBG in humans. Studies using G6pc2 knockout mice suggest that G6pc2 regulates the glucose sensitivity of insulin secretion. G6PC2 and the related G6PC1 and G6PC3 genes encode glucose-6-phosphatase catalytic subunits. This study describes a functional analysis of 22 non-synonymous G6PC2 SNPs, that alter amino acids that are conserved in human G6PC1, mouse G6pc1 and mouse G6pc2, with the goal of identifying variants that potentially affect G6PC2 activity/expression. Published data suggest strong conservation of catalytically important amino acids between all four proteins and the related G6PC3 isoform. Because human G6PC2 has very low glucose-6-phosphatase activity we used an indirect approach, examining the effect of these SNPs on mouse G6pc1 activity. Using a novel in situ functional assay for glucose-6-phosphatase activity we demonstrate that the amino acid changes associated with the human G6PC2 rs144254880 (Arg79Gln), rs149663725 (Gly114Arg) and rs2232326 (Ser324Pro) SNPs reduce mouse G6pc1 enzyme activity without affecting protein expression. The Arg79Gln variant alters an amino acid mutation of which, in G6PC1, has previously been shown to cause glycogen storage disease type 1a. We also demonstrate that the rs368382511 (Gly8Glu), rs138726309 (His177Tyr), rs2232323 (Tyr207Ser) rs374055555 (Arg293Trp), rs2232326 (Ser324Pro), rs137857125 (Pro313Leu) and rs2232327 (Pro340Leu) SNPs confer decreased G6PC2 protein expression. In summary, these studies identify multiple G6PC2 variants that have the potential to be associated with altered FBG in humans. PMID:27611587

  20. Functional Analysis of Mouse G6pc1 Mutations Using a Novel In Situ Assay for Glucose-6-Phosphatase Activity and the Effect of Mutations in Conserved Human G6PC1/G6PC2 Amino Acids on G6PC2 Protein Expression.

    PubMed

    Boortz, Kayla A; Syring, Kristen E; Pound, Lynley D; Wang, Yingda; Oeser, James K; O'Brien, Richard M

    2016-01-01

    Elevated fasting blood glucose (FBG) has been associated with increased risk for development of type 2 diabetes. Single nucleotide polymorphisms (SNPs) in G6PC2 are the most important common determinants of variations in FBG in humans. Studies using G6pc2 knockout mice suggest that G6pc2 regulates the glucose sensitivity of insulin secretion. G6PC2 and the related G6PC1 and G6PC3 genes encode glucose-6-phosphatase catalytic subunits. This study describes a functional analysis of 22 non-synonymous G6PC2 SNPs, that alter amino acids that are conserved in human G6PC1, mouse G6pc1 and mouse G6pc2, with the goal of identifying variants that potentially affect G6PC2 activity/expression. Published data suggest strong conservation of catalytically important amino acids between all four proteins and the related G6PC3 isoform. Because human G6PC2 has very low glucose-6-phosphatase activity we used an indirect approach, examining the effect of these SNPs on mouse G6pc1 activity. Using a novel in situ functional assay for glucose-6-phosphatase activity we demonstrate that the amino acid changes associated with the human G6PC2 rs144254880 (Arg79Gln), rs149663725 (Gly114Arg) and rs2232326 (Ser324Pro) SNPs reduce mouse G6pc1 enzyme activity without affecting protein expression. The Arg79Gln variant alters an amino acid mutation of which, in G6PC1, has previously been shown to cause glycogen storage disease type 1a. We also demonstrate that the rs368382511 (Gly8Glu), rs138726309 (His177Tyr), rs2232323 (Tyr207Ser) rs374055555 (Arg293Trp), rs2232326 (Ser324Pro), rs137857125 (Pro313Leu) and rs2232327 (Pro340Leu) SNPs confer decreased G6PC2 protein expression. In summary, these studies identify multiple G6PC2 variants that have the potential to be associated with altered FBG in humans.

  1. REVEALING COMPANIONS TO NEARBY STARS WITH ASTROMETRIC ACCELERATION

    SciTech Connect

    Tokovinin, Andrei; Hartung, Markus; Hayward, Thomas L.; Makarov, Valeri V. E-mail: mhartung@gemini.edu E-mail: valeri.makarov@usno.navy.mil

    2012-07-15

    A subset of 51 Hipparcos astrometric binaries among FG dwarfs within 67 pc has been surveyed with the Near-Infrared Coronagraphic Imager adaptive optics system at Gemini-S, directly resolving for the first time 17 subarcsecond companions and 7 wider ones. Using these data together with published speckle interferometry of 57 stars, we compare the statistics of resolved astrometric companions with those of a simulated binary population. The fraction of resolved companions is slightly lower than expected from binary statistics. About 10% of astrometric companions could be 'dark' (white dwarfs and close pairs of late M-dwarfs). To our surprise, several binaries are found with companions too wide to explain the acceleration. Re-analysis of selected intermediate astrometric data shows that some acceleration solutions in the original Hipparcos catalog are spurious.

  2. Stacked insulator induction accelerator gaps

    SciTech Connect

    Houck, T.I.; Westenskow, G.A.; Kim, J.S.; Eylon, S.; Henestroza, E.; Yu, S.S.; Vanecek, D.

    1997-05-01

    Stacked insulators, with alternating layers of insulating material and conducting film, have been shown to support high surface electrical field stresses. We have investigated the application of the stacked insulator technology to the design of induction accelerator modules for the Relativistic-Klystron Two-Beam Accelerator program. The rf properties of the accelerating gaps using stacked insulators, particularly the impedance at frequencies above the beam pipe cutoff frequency, are investigated. Low impedance is critical for Relativistic-Klystron Two-Beam Accelerator applications where a high current, bunched beam is trsnsported through many accelerating gaps. An induction accelerator module designs using a stacked insulator is presented.

  3. The Strong Decay Mode J/ψ for the Pentaquark States P_c^+(4380) and P_c^+(4450) in a Σ_cbar{D}^* Molecular Scenario

    NASA Astrophysics Data System (ADS)

    Dong, Yubing; Lü, Qi-Fang

    2017-01-01

    The strong decays of P_c^+(4380) → J/ψ p and P_c^+(4450) → J/ψ p are studied based on a Σ_c bar{D}^* molecule scenario. Different assignments for the spin-parity of the two P_c states are considered. Our results exclude all the P- wave Σ_c {bar{D}}^* assignments, while the estimated widths of the S wave are both allowed by the present experimental data of the two P_c states. Moreover, we discuss the other two scenarios of Σ_c^* bar{D} and Σ_c^* bar{D}^* in heavy quark limit with J^P=3/2^-, and find the Σ_c^* bar{D} system for P_c(4380) might be possible.

  4. Whole left ventricular functional assessment from two minutes free breathing multi-slice CINE acquisition

    NASA Astrophysics Data System (ADS)

    Usman, M.; Atkinson, D.; Heathfield, E.; Greil, G.; Schaeffter, T.; Prieto, C.

    2015-04-01

    Two major challenges in cardiovascular MRI are long scan times due to slow MR acquisition and motion artefacts due to respiratory motion. Recently, a Motion Corrected-Compressed Sensing (MC-CS) technique has been proposed for free breathing 2D dynamic cardiac MRI that addresses these challenges by simultaneously accelerating MR acquisition and correcting for any arbitrary motion in a compressed sensing reconstruction. In this work, the MC-CS framework is combined with parallel imaging for further acceleration, and is termed Motion Corrected Sparse SENSE (MC-SS). Validation of the MC-SS framework is demonstrated in eight volunteers and three patients for left ventricular functional assessment and results are compared with the breath-hold acquisitions as reference. A non-significant difference (P > 0.05) was observed in the volumetric functional measurements (end diastolic volume, end systolic volume, ejection fraction) and myocardial border sharpness values obtained with the proposed and gold standard methods. The proposed method achieves whole heart multi-slice coverage in 2 min under free breathing acquisition eliminating the time needed between breath-holds for instructions and recovery. This results in two-fold speed up of the total acquisition time in comparison to the breath-hold acquisition.

  5. Mass spectrometry with accelerators.

    PubMed

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  6. Estimated proinsulin processing activity of prohormone convertase (PC) 1/3 rather than PC2 is decreased in pancreatic β-cells of type 2 diabetic patients.

    PubMed

    Ozawa, Sachihiko; Katsuta, Hidenori; Suzuki, Kiyoshi; Takahashi, Kazuto; Tanaka, Toshiaki; Sumitani, Yoshikazu; Nishida, Susumu; Yoshimoto, Katsuhiko; Ishida, Hitoshi

    2014-01-01

    Type 2 diabetic (T2D) patients exhibit fasting relative hyperproinsulinemia owing to pancreatic β-cell dysfunction. To clarify the mechanism underlying this hyperproinsulinemic state, we evaluated the activities of the endopeptidases prohormone convertase (PC) 1/3 and PC2 in T2D patients. Fasting blood levels of intact proinsulin (IPI), total proinsulin (t-PI) and C-peptide were measured simultaneously, and intravenous glucagon loading was performed to investigate the dynamics of circulating proinsulin-related molecules released from pancreatic β-cells in 12 healthy volunteers and 18 T2D patients. Taking advantage of the 95% cross-reactivity between proinsulin and des-31,32-proinsulin (des-31,32-PI) with the human proinsulin radioimmunoassay kit used in this study, we estimated PC1/3 and PC2 activities using the following formulas: des-31,32-PI = (t-PI-IPI)/0.95; PC1/3 activity = des-31,32-PI/IPI; and PC2 activity = C-peptide/des-31,32-PI. C-peptide responses to glucagon were slightly lower among T2D patients. IPI and the IPI/C-peptide ratio were significantly higher in T2D patients (p<0.05 and p<0.01, respectively). There was no difference in des-31,32-PI levels or PC2 activity between the two groups. However, PC1/3 activity was significantly lower in T2D patients than in the control group (p<0.01). We propose that decreased activity of PC1/3 rather than PC2 in pancreatic β-cells is involved in the impaired proinsulin processing, resulting in elevated IPI levels in T2D patients.

  7. A VAX and PC-based data acquisition system for MCA, scanning and list-mode analysis

    NASA Astrophysics Data System (ADS)

    Churms, C. L.; Pilcher, J. V.; Springhorn, K. A.; Tapper, U. A. S.

    1993-05-01

    The design of the data acquisition system for the National Accelerator Centre's nuclear microprobe is described. The system consists of an intelligent PC scanner and imaging terminal, interfaced to a VAX-11/750 running a general purpose data acquisition package XSYS. In this way, the user friendliness of a dedicated, intelligent scanner has been combined with the flexibility of a general purpose data acquisition package. It is illustrated how simple tasks such as beam focussing, area of interest localization, and quantitative single spot PIXE or RBS analysis can be performed with minimal complexity, whereas requirements of a more complex nature can be implemented routinely using the general purpose acquisition package with standard command files. Even unique studies can be performed by means of minor software modifications.

  8. Low Dose Gamma Radiation Monitoring Through TiO{sub 2} Doped Lead Phthalocyanine (Pb-Pc) Based Schottky Device

    SciTech Connect

    Janu, Yojana; Gautam, Anil; Kumar, Manish; Prasad, Narottam; Deol, Y. S.; Roy, M. S.

    2008-04-23

    The concept of Organic thin film based solid-state dosimeters is relatively new and more effective. The organic conductor based solid-state dosimeter provides a mean for low cost, ease to fabricate and sensitive radiation sensor which can be employed as pocket dosimeter for army personals getting exposed to nuclear radiation while working in the radioactive environment This concept is being utilized here for monitoring the effect of nuclear radiation on our organic material based sandwiched devices. In the present communication, lead Phthalocyanine (PbPc) doped with TiO{sub 2} (5% by weight) is developed into the form of thin film structure. The developed ITO/PbPc: TiO{sub 2}/Ag Schottky device structure was characterized in terms of change in its electrical and optical properties before and after exposure to radiation Exposure to radiation imparts an accelerated decrease in forward bias current and capacitance characteristics reveal a linear relationship between dose v/s current behavior which supports its suitability as pocket dosimeter for the dose ranging from 50 mR to 800 mR.

  9. Review of ion accelerators

    SciTech Connect

    Alonso, J.

    1990-06-01

    The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here.

  10. Accelerator research studies

    SciTech Connect

    Not Available

    1992-01-01

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks.

  11. Commissioning the GTA accelerator

    SciTech Connect

    Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Bowling, S.; Brown, S.; Cole, R.; Gilpatrick, J.D.; Garnett, R.; Guy, F.W.; Ingalls, W.B.; Johnson, K.F.; Kerstiens, D.; Little, C.; Lohsen, R.A.; Lloyd, S.; Lysenko, W.P.; Mottershead, C.T.; Neuschaefer, G.; Power, J.; Rusthoi, D.P.; Sandoval, D.P. Stevens, R.R. Jr.; Vaughn, G.; Wadlinger, E.A.; Yuan, V.; Connolly, R.; Weiss, R.; Saadatmand, K.

    1992-09-01

    The Ground Test Accelerator (GTA) is supported by the Strategic Defense command as part of their Neutral Particle Beam (NPB) program. Neutral particles have the advantage that in space they are unaffected by the earth`s magnetic field and travel in straight lines unless they enter the earth`s atmosphere and become charged by stripping. Heavy particles are difficult to stop and can probe the interior of space vehicles; hence, NPB can function as a discriminator between warheads and decoys. We are using GTA to resolve the physics and engineering issues related to accelerating, focusing, and steering a high-brightness, high-current H{sup -} beam and then neutralizing it. Our immediate goal is to produce a 24-MeV, 50mA device with a 2% duty factor.

  12. Commissioning the GTA accelerator

    SciTech Connect

    Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Bowling, S.; Brown, S.; Cole, R.; Gilpatrick, J.D.; Garnett, R.; Guy, F.W.; Ingalls, W.B.; Johnson, K.F.; Kerstiens, D.; Little, C.; Lohsen, R.A.; Lloyd, S.; Lysenko, W.P.; Mottershead, C.T.; Neuschaefer, G.; Power, J.; Rusthoi, D.P.; Sandoval, D.P. Stevens, R.R. Jr.; Vaughn, G.; Wadlinger, E.A.; Yuan, V. ); Connolly, R.; Weiss, R. (Gr

    1992-01-01

    The Ground Test Accelerator (GTA) is supported by the Strategic Defense command as part of their Neutral Particle Beam (NPB) program. Neutral particles have the advantage that in space they are unaffected by the earth's magnetic field and travel in straight lines unless they enter the earth's atmosphere and become charged by stripping. Heavy particles are difficult to stop and can probe the interior of space vehicles; hence, NPB can function as a discriminator between warheads and decoys. We are using GTA to resolve the physics and engineering issues related to accelerating, focusing, and steering a high-brightness, high-current H{sup -} beam and then neutralizing it. Our immediate goal is to produce a 24-MeV, 50mA device with a 2% duty factor.

  13. Auroral ion acceleration

    NASA Astrophysics Data System (ADS)

    Shalimov, S. L.

    From the altitude of 500 km to 15 R sub E everywhere conic like distributions of H+, O+, He+ ions are moving upwards from the ionosphere along the geomagnetic field lines in the auroral zone. The distributed ions suggest the existence of ion transverse acceleration mechanisms (ITAM) acting below the observation point. The more plausible mechanisms are connected with the resonance of the type wave particle between ions and the observed EIC and LH waves and are also due to the existence of the local transverse electric fields in the ionoshere and the magnetosphere. The known ion transverse acceleration mechanisms were complemented by new results. The conical distributions of ionospheric ions at different altitudes in the auroral zone are pointed out.

  14. Review of accelerator instrumentation

    SciTech Connect

    Pellegrin, J.L.

    1980-05-01

    Some of the problems associated with the monitoring of accelerator beams, particularly storage rings' beams, are reviewed along with their most common solutions. The various electrode structures used for the measurement of beam current, beam position, and the detection of the bunches' transverse oscillations, yield pulses with sub-nanosecond widths. The electronics for the processing of these short pulses involves wide band techniques and circuits usually not readily available from industry or the integrated circuit market: passive or active, successive integrations, linear gating, sample-and-hold circuits with nanosecond acquisition time, etc. This report also presents the work performed recently for monitoring the ultrashort beams of colliding linear accelerators or single-pass colliders. To minimize the beam emittance, the beam position must be measured with a high resolution, and digitized on a pulse-to-pulse basis. Experimental results obtained with the Stanford two-mile Linac single bunches are included.

  15. Hardware Accelerated Simulated Radiography

    SciTech Connect

    Laney, D; Callahan, S; Max, N; Silva, C; Langer, S; Frank, R

    2005-04-12

    We present the application of hardware accelerated volume rendering algorithms to the simulation of radiographs as an aid to scientists designing experiments, validating simulation codes, and understanding experimental data. The techniques presented take advantage of 32 bit floating point texture capabilities to obtain validated solutions to the radiative transport equation for X-rays. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedra that produces simulated radiographs in the absorption-only regime. A sorted tetrahedral projection algorithm is presented that simulates radiographs of emissive materials. We apply the tetrahedral projection algorithm to the simulation of experimental diagnostics for inertial confinement fusion experiments on a laser at the University of Rochester. We show that the hardware accelerated solution is faster than the current technique used by scientists.

  16. Adaptive control for accelerators

    DOEpatents

    Eaton, Lawrie E.; Jachim, Stephen P.; Natter, Eckard F.

    1991-01-01

    An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio frequency field in an accelerator cavity during successive pulses of the beam into the cavity. A digital signal processor enables an adaptive algorithm to generate a feedforward error correcting signal functionally determined by the feedback error obtained by a beam pulse loading the cavity after the previous correcting signal was applied to the cavity. Each cavity feedforward correcting signal is successively stored in the digital processor and modified by the feedback error resulting from its application to generate the next feedforward error correcting signal. A feedforward error correcting signal is generated by the digital processor in advance of the beam pulse to enable a composite correcting signal and the beam pulse to arrive concurrently at the cavity.

  17. Pulsed electromagnetic gas acceleration

    NASA Technical Reports Server (NTRS)

    Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

    1971-01-01

    Experimental data were combined with one-dimensional conservation relations to yield information on the energy deposition ratio in a parallel-plate accelerator, where the downstream flow was confined to a constant area channel. Approximately 70% of the total input power was detected in the exhaust flow, of which only about 20% appeared as directed kinetic energy, thus implying that a downstream expansion to convert chamber enthalpy into kinetic energy must be an important aspect of conventional high power MPD arcs. Spectroscopic experiments on a quasi-steady MPD argon accelerator verified the presence of A(III) and the absence of A(I), and indicated an azimuthal structure in the jet related to the mass injection locations. Measurements of pressure in the arc chamber and impact pressure in the exhaust jet using a piezocrystal backed by a Plexiglas rod were in good agreement with the electromagnetic thrust model.

  18. Pulsed Drift Tube Accelerator

    SciTech Connect

    Faltens, A.

    2004-10-25

    The pulsed drift-tube accelerator (DTA) concept was revived by Joe Kwan and John Staples and is being considered for the HEDP/WDM application. It could be used to reach the full energy or as an intermediate accelerator between the diode and a high gradient accelerator such as multi-beam r.f. In the earliest LBNL HIF proposals and conceptual drivers it was used as an extended injector to reach energies where an induction linac with magnetic quadrupoles is the best choice. For HEDP, because of the very short pulse duration, the DTA could provide an acceleration rate of about 1MV/m. This note is divided into two parts: the first, a design based on existing experience; the second, an optimistic extrapolation. The first accelerates 16 parallel K{sup +} beams at a constant line charge density of 0.25{micro} C/m per beam to 10 MeV; the second uses a stripper and charge selector at around 4MeV followed by further acceleration to reach 40 MeV. Both benefit from more compact sources than the present 2MV injector source, although that beam is the basis of the first design and is a viable option. A pulsed drift-tube accelerator was the first major HIF experiment at LBNL. It was designed to produce a 2{micro}s rectangular 1 Ampere C{sub s}{sup +} beam at 2MeV. It ran comfortably at 1.6MeV for several years, then at lower voltages and currents for other experiments, and remnants of that experiment are in use in present experiments, still running 25 years later. The 1A current, completely equivalent to 1.8A K{sup +}, was chosen to be intermediate between the beamlets appropriate for a multi-beam accelerator, and a single beam of, say, 10A, at injection energies. The original driver scenarios using one large beam on each side of the reactor rapidly fell out of favor because of the very high transverse and longitudinal fields from the beam space charge, circa 1MV/cm and 250 kV/cm respectively, near the chamber and because of aberrations in focusing a large diameter beam down to a 1

  19. 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.

  20. Accelerators for Cancer Therapy

    DOE R&D Accomplishments Database

    Lennox, Arlene J.

    2000-05-30

    The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy.

  1. Noninvasive assessment of tissue distribution and tumor pharmacokinetics of Pc 181, a silicon phthalocyanine analogue, in mice

    NASA Astrophysics Data System (ADS)

    Bai, Lihua; Guo, Jianxia; Clausen, Dana M.; Eiseman, Julie L.

    2010-02-01

    Objective: In in vitro photodynamic therapy, the LD50 of Pc 181 has been reported to be 7 to 8 times less than that of silicon phthalocyanine 4 (Pc 4). The Optical Pharmacokinetic System (OPS) can measure photosensitizer concentrations in accessible tissues non-invasively. We used OPS to evaluate the tumor pharmacokinetics of Pc 181 and Pc 4 and the tissue drug distribution in SCID mice bearing either human breast cancer MDA-MB-231 or human head and neck squamous cell carcinoma SCC-15 xenografts. Methods: Following iv administration of 2.5 mg/kg Pc 181 or 2 mg/kg Pc 4 to SCID mice, OPS measurements were taken on tumor and normal tissues between 5 and 4320 min in vivo or in situ. Results: Large variations in tumor Pc 181 concentrations were observed among mice. In MDA-MB-231 tumors, the Pc 181 concentration peaked at 240 min, and was retained in the tumor. Tumor Pc 181 concentrations were much less than the tumor Pc 4 concentrations at an equimolar dose. Pc 181 concentrations were the highest in liver, followed by spleen, and kidney. In mice bearing SCC-15 xenografts, skin and underlying tissue Pc 181 concentrations were higher than tumor concentrations at all time points examined. Conclusions: This first Pc 181 pharmacokinetics study described a tissue Pc 181 distribution similar to that of Pc 4. However, tumor Pc 181 concentrations were lower than those of Pc 4 at equimolar doses.

  2. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  3. Linear induction accelerator

    DOEpatents

    Buttram, M.T.; Ginn, J.W.

    1988-06-21

    A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

  4. Compact pulsed accelerator

    SciTech Connect

    Rhee, M.J.; Schneider, R.F.

    1983-01-01

    The formation of fast pulses from a current charged transmission line and opening switch is described. By employing a plasma focus as an opening switch and diode in the prototype device, a proton beam of peak energy 250 keV is produced. The time integrated energy spectrum of the beam is constructed from a Thomson spectrograph. Applications of this device as an inexpensive and portable charged particle accelerator are discussed. 7 refs., 5 figs., 1 tab.

  5. ION ACCELERATION SYSTEM

    DOEpatents

    Luce, J.S.; Martin, J.A.

    1960-02-23

    Well focused, intense ion beams are obtained by providing a multi- apertured source grid in front of an ion source chamber and an accelerating multi- apertured grid closely spaced from and in alignment with the source grid. The longest dimensions of the elongated apertures in the grids are normal to the direction of the magnetic field used with the device. Large ion currents may be withdrawn from the source, since they do not pass through any small focal region between the grids.

  6. Frontiers of accelerator instrumentation

    SciTech Connect

    Ross, M.

    1992-08-01

    New technology has permitted significant performance improvements of established instrumentation techniques including beam position and profile monitoring. Fundamentally new profile monitor strategies are required for the next generation of accelerators, especially linear colliders (LC). Beams in these machines may be three orders of magnitude smaller than typical beams in present colliders. In this paper we review both the present performance levels achieved by conventional systems and present some new ideas for future colliders.

  7. Accelerator simulation using computers

    SciTech Connect

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a multi-track'' simulation and analysis code can be used for these applications.

  8. Accelerator simulation using computers

    SciTech Connect

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a ``multi-track`` simulation and analysis code can be used for these applications.

  9. Accelerated Profile HMM Searches.

    PubMed

    Eddy, Sean R

    2011-10-01

    Profile hidden Markov models (profile HMMs) and probabilistic inference methods have made important contributions to the theory of sequence database homology search. However, practical use of profile HMM methods has been hindered by the computational expense of existing software implementations. Here I describe an acceleration heuristic for profile HMMs, the "multiple segment Viterbi" (MSV) algorithm. The MSV algorithm computes an optimal sum of multiple ungapped local alignment segments using a striped vector-parallel approach previously described for fast Smith/Waterman alignment. MSV scores follow the same statistical distribution as gapped optimal local alignment scores, allowing rapid evaluation of significance of an MSV score and thus facilitating its use as a heuristic filter. I also describe a 20-fold acceleration of the standard profile HMM Forward/Backward algorithms using a method I call "sparse rescaling". These methods are assembled in a pipeline in which high-scoring MSV hits are passed on for reanalysis with the full HMM Forward/Backward algorithm. This accelerated pipeline is implemented in the freely available HMMER3 software package. Performance benchmarks show that the use of the heuristic MSV filter sacrifices negligible sensitivity compared to unaccelerated profile HMM searches. HMMER3 is substantially more sensitive and 100- to 1000-fold faster than HMMER2. HMMER3 is now about as fast as BLAST for protein searches.

  10. 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.

  11. Accelerator mass spectrometry.

    PubMed

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples.

  12. Electrostatic Plasma Accelerator (EPA)

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Aston, Graeme

    1995-01-01

    The application of electric propulsion to communications satellites, however, has been limited to the use of hydrazine thrusters with electric heaters for thrust and specific impulse augmentation. These electrothermal thrusters operate at specific impulse levels of approximately 300 s with heater powers of about 500 W. Low power arcjets (1-3 kW) are currently being investigated as a way to increase specific impulse levels to approximately 500 s. Ion propulsion systems can easily produce specific impulses of 3000 s or greater, but have yet to be applied to communications satellites. The reasons most often given for not using ion propulsion systems are their high level of overall complexity, low thrust with long burn times, and the difficulty of integrating the propulsion system into existing commercial spacecraft busses. The Electrostatic Plasma Accelerator (EPA) is a thruster concept which promises specific impulse levels between low power arcjets and those of the ion engine while retaining the relative simplicity of the arcjet. The EPA thruster produces thrust through the electrostatic acceleration of a moderately dense plasma. No accelerating electrodes are used and the specific impulse is a direct function of the applied discharge voltage and the propellant atomic mass.

  13. Berkeley Proton Linear Accelerator

    DOE R&D Accomplishments Database

    Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

    1953-10-13

    A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

  14. ACCELERATION INTEGRATING MEANS

    DOEpatents

    Wilkes, D.F.

    1961-08-29

    An acceleration responsive device is described. A housing has at one end normally open electrical contacts and contains a piston system with a first part of non-magnetic material having metering orifices in the side walls for forming an air bearing between it and the walls of the housing; this first piston part is normally held against the other end of the housing from the noted contacts by a second piston or reset part. The reset part is of partly magnetic material, is separable from the flrst piston part, and is positioned within the housing intermediate the contacts and the first piston part. A magnet carried by the housing imposes a retaining force upon the reset part, along with a helical compression spring that is between the reset part and the end with the contacts. When a predetermined acceleration level is attained, the reset part overcomes the bias or retaining force provided by the magnet and the spring'' snaps'' into a depression in the housing adjacent the contacts. The first piston part is then free to move toward the contacts with its movement responsive tc acceleration forces and the metering orifices. (AEC)

  15. French nuclear physics accelerator opens

    NASA Astrophysics Data System (ADS)

    Dumé, Belle

    2016-12-01

    A new €140m particle accelerator for nuclear physics located at the French Large Heavy Ion National Accelerator (GANIL) in Caen was inaugurated last month in a ceremony attended by French president François Hollande.

  16. FADD null mouse embryonic fibroblasts undergo apoptosis after photosensitization with the silicon phthalocyanine Pc 4.

    PubMed

    Nagy, B; Yeh, W C; Mak, T W; Chiu, S M; Separovic, D

    2001-01-01

    Oxidative stress, such as photodynamic therapy with the silicon phthalocyanine Pc 4 (Pc 4-PDT), can induce apoptosis and tumor necrosis factor alpha (TNF) production. TNF receptors, as well as other death receptors, have been implicated in stress-induced apoptosis. To assess directly the role of FADD, a death receptor-associated protein, in induction of apoptosis post-Pc 4-PDT, embryonic fibroblasts from FADD knock out (k/o) and wild-type (wt) mice were used. Pc 4-PDT induced casp-3 activation and apoptosis in both cell types. In the presence of zVAD, a pancaspase inhibitor, Pc 4-PDT-induced apoptosis was abrogated in both cell lines. Fumonisin B1 (FB), an inhibitor of ceramide synthase, had no effect on apoptosis after Pc 4-PDT in either cell line. Similar to Pc 4-PDT, exogenous C6-ceramide bypassed FADD deficiency and induced zVAD-sensitive apoptosis. In contrast to Pc 4 photosensitization, TNF did not induce either apoptosis or ceramide accumulation in FADD k/o cells. In the absence of FADD deficiency, TNF-induced apoptosis was zVAD-sensitive and FB-insensitive. Induced ceramide levels remained elevated after cotreatment with TNF and zVAD in FADD wt cells. Taken together, these data provide genetic evidence for a lack of FADD requirement in Pc 4-PDT- or C6-ceramide-induced apoptosis. FB-sensitive ceramide production accompanies, but does not suffice, for apoptosis after Pc 4 photosensitization or TNF.

  17. Delivery of the photosensitizer Pc 4 in PEG-PCL micelles for in vitro PDT studies.

    PubMed

    Master, Alyssa M; Rodriguez, Myriam E; Kenney, Malcolm E; Oleinick, Nancy L; Gupta, Anirban Sen

    2010-05-01

    The silicon phthalocyanine Pc 4 is a second-generation photosensitizer that has several properties superior to other photosensitizers currently approved by the FDA, and it has shown significant promise for photodynamic therapy (PDT) in several cancer cells in vitro and model tumor systems in vivo. However, because of the high hydrophobicity of Pc 4, its formulation for in vivo delivery and favorable biodistribution become challenging. To this end, we are studying encapsulation and delivery of Pc 4 in block copolymer micelles. Here, we report the development of biocompatible PEG-PCL micelle nanoparticles, encapsulation of Pc 4 within the micelle core by hydrophobic association with the PCL block, and in vitro PDT studies of the micelle-formulated Pc 4 in MCF-7c3 human breast cancer cells. Our studies demonstrate efficient encapsulation of Pc 4 in the micelles, intracellular uptake of the micelle-formulated Pc 4 in cells, and significant cytotoxic effect of the formulation upon photoirradiation. Quantitative estimation of the extent of Pc 4 loading in the micelles and the photocytotoxicity of the micelle-incorporated Pc 4 demonstrate the promise of our approach to develop a biocompatible nanomedicine platform for tumor-targeted delivery of Pc 4 for site-selective PDT.

  18. PC Index as a Means to Monitor Processes in the Auroral Zone

    NASA Astrophysics Data System (ADS)

    Troshichev, Oleg

    2016-07-01

    The PC index was introduced [Troshichev et al., 1988] to characterize the polar cap magnetic activity generated by the geoeffective interplanetary electric field. Results of recent studies [Troshichev and Janzhura, 2012; Troshichev and Sormakov, 2015] are strongly indicative of PC index as a proxy of the solar wind energy that entered into the magnetosphere. The PC index in this charge can be successfully used to monitor processes in the auroral zone: 1. PC index well correlates with intensity of the Region 1 field-aligned currents measured by SWARM satellites on the auroral oval poleward boundary. As it is known, the R1 field-aligned currents flow into ionosphere in the morning auroral oval and flow out of ionosphere in the evening oval. The R1 FAC intensity and, correspondingly, the PC value increase in tandem before the substorm sudden onset. 2. PC-index can be taken as Input Parameter in Empirical Auroral Precipitation Model "OVATION-prime" [Newell, 2009] instead of the coupling function dØMP/dt. Use of the 1-min PC index in the modified OVATION-PC model provides the much better timing of the auroral precipitation with allowance for actual state of the magnetosphere. 3. There is a strong correspondence between the behavior of PC and development of magnetic disturbances in the auroral zone: the magnetic substorms are preceded by the PC index growth, the substorm onsets are commonly associated with a sharp increase in the PC growth rate, the substorm occurrence reaches the maximum when PC exceeds the threshold value ~ 1.5±0.5 mV/m, the linear correlation between the PC and AL values is typical of all classes of substorms, irrespective of their power. There regularities provide possibility to nowcast the substorm development.

  19. Application of the Karhunen-Loeve transform temporal image filter to reduce noise in real-time cardiac cine MRI

    NASA Astrophysics Data System (ADS)

    Ding, Yu; Chung, Yiu-Cho; Raman, Subha V.; Simonetti, Orlando P.

    2009-06-01

    Real-time dynamic magnetic resonance imaging (MRI) typically sacrifices the signal-to-noise ratio (SNR) to achieve higher spatial and temporal resolution. Spatial and/or temporal filtering (e.g., low-pass filtering or averaging) of dynamic images improves the SNR at the expense of edge sharpness. We describe the application of a temporal filter for dynamic MR image series based on the Karhunen-Loeve transform (KLT) to remove random noise without blurring stationary or moving edges and requiring no training data. In this paper, we present several properties of this filter and their effects on filter performance, and propose an automatic way to find the filter cutoff based on the autocorrelation of the eigenimages. Numerical simulation and in vivo real-time cardiac cine MR image series spanning multiple cardiac cycles acquired using multi-channel sensitivity-encoded MRI, i.e., parallel imaging, are used to validate and demonstrate these properties. We found that in this application, the noise standard deviation was reduced to 42% of the original with no apparent image blurring by using the proposed filter cutoff. Greater noise reduction can be achieved by increasing the length of the image series. This advantage of KLT filtering provides flexibility in the form of another scan parameter to trade for SNR.

  20. Measurement of three-dimensional normal vectors, principal curvatures, and wall thickness of the heart using cine-MRI

    NASA Astrophysics Data System (ADS)

    Coghlan, Leslie; Singleton, H. R.; Dell'Italia, L. J.; Linderholm, C. E.; Pohost, G. M.

    1995-05-01

    We have developed a method for measuring the detailed in vivo three dimensional geometry of the left and right ventricles using cine-magnetic resonance imaging. From data in the form of digitized short axis outlines, the normal vectors, principal curvatures and directions, and wall thickness were computed. The method was evaluated on simulated ellipsoids and on human MRI data. Measurements of normal vectors and of wall thickness were very accurate in simulated data and appeared appropriate in patient data. On simulated data, measurements of the principal curvature k1 (corresponding approximately to the short axis direction of the left ventricle) and of principal directions were quite accurate, but measurements of the other principal curvature (k2) were less accurate. The reasons behind this are considered. We expect improvements in the accuracy with thinner slices and improved representation of the surface data. Gradient echo images were acquired from 8 dogs with a 1.5T system (Philips Gyroscan) at baseline and four months after closed chest experimentally produced mitral regurgitation (MR). The product (k1 + k2) X wall thickness averaged over all slices at end-diastole was significantly lower after surgery (n equals 8, p < 0.005). These geometry changes were consistent with the expected increase in wall stress after MR.